阅读说明：本技术 不良预测装置 (Failure prediction device ) 是由 中野元就 中山一树 近藤宏史 今村雄介 于 2021-03-31 设计创作，主要内容包括：本发明涉及一种能够预防缝制不良的发生的不良预测装置。缝纫机从在缝制过程中周期性地变动的变动张力、变动移动量中获取特征量。特征量是在缝制不良发生前变动的、表示缝制不良发生的特征的量。挑线杆提起期间和梭子捕捉期间的面线张力、面线移动量为特征量的一例。缝纫机基于以预测单位(例如一针的量的缝制期间)为单位的特征量的推移来预测缝制不良发生。缝纫机在挑线杆提起期间、梭子捕捉期间各自的面线张力呈增加趋势时或在挑线杆提起期间和梭子捕捉期间的面线移动量呈减少趋势时预测到断线发生。(The present invention relates to a failure prediction device capable of preventing the occurrence of sewing failure. The sewing machine acquires a characteristic amount from a varying tension and a varying movement amount which periodically vary during sewing. The characteristic amount is an amount of characteristic that changes before the sewing failure occurs and indicates the sewing failure. The needle thread tension and needle thread movement amount during the raising of the thread take-up lever and the capturing of the shuttle are examples of the characteristic amount. The sewing machine predicts the occurrence of sewing failure based on the transition of the characteristic quantity in a unit of prediction unit (for example, sewing period of one stitch). The sewing machine predicts the occurrence of thread breakage when the tension of the upper thread increases during the lifting of the take-up lever and the capturing of the shuttle, or when the moving amount of the upper thread decreases during the lifting of the take-up lever and the capturing of the shuttle.)

1. A failure prediction device is characterized in that,

the failure prediction device includes:

an acquisition unit (91) that acquires a variable that periodically varies in accordance with the vertical movement of a needle through which an upper thread is inserted during sewing and that is associated with the upper thread;

a storage unit (93) that stores the variable acquired by the acquisition unit; and

and a prediction unit that predicts the occurrence of a sewing failure in a sewing process of a sewing machine based on a change in a feature amount that is an amount indicating a feature among the variables stored in the storage unit.

2. The failure prediction device according to claim 1,

the prediction unit predicts the occurrence of the sewing failure based on a transition of the characteristic amount in units of one or more cycles of vertical movement of the needle.

3. The failure prediction apparatus according to claim 2,

the characteristic amount is an amount of the variable at a prescribed timing based on one cycle of the vertical movement of the needle.

4. The bad prediction apparatus according to claim 2 or 3,

the characteristic amount is at least one of a magnitude of the variable at a predetermined timing in one cycle of the vertical movement of the needle or one cycle of the vertical movement of the needle, and a number of times the magnitude of the variable reaches a predetermined variable threshold.

5. The bad prediction apparatus according to claim 4,

the prediction unit identifies a prediction level indicating a degree of possibility of the sewing failure when the sewing failure is predicted from the transition of the feature amount.

6. The bad prediction apparatus according to claim 4 or 5,

the acquiring section has at least one of a tension acquiring section that acquires tension of the upper thread and a movement amount acquiring section that acquires a movement amount of the upper thread,

the variable is at least one of the tension and the movement amount.

7. The failure prediction device according to claim 6,

the poor sewing comprises the broken thread,

the prediction unit predicts occurrence of a disconnection based on a transition of the feature amount per the unit, which is at least one of the tension and the movement amount of the transition of the feature amount.

8. The failure prediction device according to claim 6,

the poor sewing comprises a skip stitch,

the prediction unit predicts the occurrence of a skip stitch based on a transition of the feature amount per the unit, which is at least one of the tension and the movement amount of the transition of the feature amount.

9. The failure prediction device according to claim 6,

the poor sewing comprises poor take-up of the thread,

the prediction unit predicts the occurrence of a wire-rewinding failure for each of the units of the characteristic amount based on a transition of the characteristic amount, which is at least one of the tension and the movement amount of the transition of the characteristic amount.

10. The bad prediction apparatus according to claim 7,

the sewing machine has: a thread take-up lever (23) for taking up the upper thread; and a shuttle (49) for catching a loop of the upper thread inserted into the needle,

the predetermined timing is at least one of a period during which the thread take-up lever lifts the upper thread and a period during which the shuttle catches the loop of the upper thread and the shuttle passes from the loop drill of the upper thread,

the prediction unit predicts that a wire break occurs when at least one of a transition of the characteristic amount of the tension in the predetermined time per unit increases and a transition of the characteristic amount of the movement amount in the predetermined time per unit decreases.

11. The failure prediction device according to claim 8,

The sewing machine has a thread take-up lever for taking up the upper thread,

the prediction unit predicts that a stitch skipping occurs when a transition of the characteristic amount of the tension per unit of the thread decreases during a period in which the thread take-up lever lifts the upper thread and when a transition of the characteristic amount per unit of the movement amount within the predetermined period decreases.

12. The failure prediction device according to claim 11,

the sewing machine has a shuttle which catches a loop of the upper thread inserted through the needle,

in the case where the variable comprises the tension,

the prediction unit predicts that a skip stitch occurs when a transition of the characteristic amount of the tension per unit in a period in which the thread take-up lever lifts the upper thread is in a decreasing trend, the shuttle at the predetermined timing catches the loop of the upper thread, and a transition of the characteristic amount of the tension per unit in a period in which the shuttle has passed from the loop drill of the upper thread is in an increasing trend.

13. The failure prediction device according to claim 9,

The sewing machine has a thread take-up lever for taking up the upper thread,

the predetermined timing is a period during which the thread take-up lever lifts the upper thread,

the prediction unit predicts that a wire-rewinding failure has occurred when at least one of a transition of the characteristic amount of the tension in the predetermined time per unit increases and a transition of the characteristic amount of the movement amount in the predetermined time per unit increases.

14. The failure prediction device according to any one of claims 1 to 13,

the sewing machine is provided with a driving part which drives to sew the cloth in the sewing process,

the failure prediction device includes an avoidance control unit that executes avoidance control for controlling the drive unit to avoid the occurrence of the sewing failure when the prediction unit predicts the occurrence of the sewing failure.

15. The bad prediction apparatus according to claim 14,

the driving part of the sewing machine is provided with a needle bar driving part (27) which enables a needle bar assembled with the machine needle to move up and down,

the avoidance control unit reduces the drive speed of the needle bar drive unit as the avoidance control.

16. The bad prediction apparatus according to claim 14,

the driving part of the sewing machine is provided with: a needle bar driving part which enables the needle bar assembled with the machine needle to move up and down; and a thread tension mechanism (22) for applying tension to the upper thread,

the avoidance control unit controls the tension applied by the thread clamping mechanism in one cycle of the vertical movement of the needle as the avoidance control.

17. The bad prediction apparatus according to claim 14,

the driving part of the sewing machine is provided with: a needle bar driving part which enables the needle bar assembled with the machine needle to move up and down; and a thread tension mechanism for applying tension to the upper thread and adjusting the movement amount of the upper thread by rotation driving,

the avoidance control unit controls at least one of a tension applied by the thread clamping mechanism and a variation in the movement amount in one cycle of the vertical movement of the needle as the avoidance control.

18. The failure prediction device according to any one of claims 14 to 17,

the failure prediction device includes a prediction stop unit that stops the drive unit when the prediction unit predicts that the sewing failure occurs after the avoidance control unit executes the avoidance control.

19. The bad prediction apparatus according to claim 7 or 10,

the sewing machine is provided with a driving part which drives to sew the cloth in the sewing process,

the failure prediction device includes a wire breakage prediction stop unit that stops the drive unit when the prediction unit predicts occurrence of the wire breakage.

20. The failure prediction device according to any one of claims 1 to 19,

the failure prediction device is provided with a notification part which notifies that the sewing failure is predicted when the prediction part predicts the sewing failure.

21. The failure prediction device according to claim 5,

the failure prediction device includes a prediction level notification unit that notifies the prediction level recognized by the prediction unit.

22. The failure prediction device according to any one of claims 14 to 18,

the failure prediction device includes an avoidance notification unit that notifies execution of the avoidance control when the avoidance control unit executes the avoidance control.

23. The failure prediction device according to claim 18,

the failure prediction device includes a stop notification unit that notifies the stop of the drive unit when the prediction stop unit stops the drive unit.

Technical Field

The present invention relates to a failure prediction device.

Background

Japanese patent application laid-open No. 201741 in 2019 discloses a stitch inspection device for detecting an abnormality in stitches of a sewing object sewn by a sewing machine. The stitch checking device is provided with a tension sensor for detecting the tension of the upper thread, and calculates a detection characteristic quantity and a reference characteristic quantity according to the detection value of the tension sensor. The detection characteristic amount indicates an actual characteristic amount of the face line tension. The reference characteristic value represents a characteristic value of the thread tension when the stitch of the sewing object is normal. The stitch inspection device stores a reference characteristic quantity calculated according to a detection value of the tension sensor in a reference characteristic quantity storage part when a stitch of a sewing object is normal. The stitch inspection device compares a detection characteristic quantity calculated according to a detection value of the tension sensor with a reference characteristic quantity stored in a reference characteristic quantity storage part to judge the abnormity of stitches of the sewing object. Since the above-described stitch inspection device detects that an abnormality of the stitches has occurred, it is impossible to prevent the abnormality of the stitches.

Disclosure of Invention

The invention aims to provide a failure prediction device capable of preventing poor sewing.

The failure prediction device according to claim 1 is characterized by comprising: an acquisition unit that acquires a variable that periodically varies in accordance with the vertical movement of a needle through which a needle thread is inserted during sewing and is related to the needle thread; a storage unit that stores the variable acquired by the acquisition unit; and a prediction unit that predicts the occurrence of a sewing failure in a sewing process of a sewing machine based on a change in a feature amount that is an amount indicating a feature among the variables stored in the storage unit. The failure prediction device predicts the occurrence of sewing failure based on the change of the characteristic quantity of the expression characteristic in the variable related to the upper thread, so that the occurrence of sewing failure can be prevented.

In the failure prediction device according to claim 2, the prediction unit may predict the sewing failure occurrence based on a change in the characteristic amount in units of one or more cycles of vertical movement of the needle. The failure prediction device can improve the precision of preventing the sewing failure.

In the failure prediction device according to claim 3, the characteristic amount may be an amount of the variable at a predetermined timing based on one cycle of vertical movement of the needle. The failure prediction device can improve the precision of preventing the sewing failure.

In the failure prediction device according to claim 4, the characteristic amount may be at least one of a magnitude of the variable at a predetermined timing in one cycle of the vertical movement of the needle or one cycle of the vertical movement of the needle, and a number of times that the magnitude of the variable reaches a predetermined variable threshold. The failure prediction device can improve the precision of preventing the sewing failure.

In the failure prediction device according to claim 5, the prediction unit may recognize a prediction level indicating a degree of possibility of the sewing failure when the sewing failure is predicted from the transition of the feature amount. The failure prediction device recognizes the prediction grade when the sewing failure is predicted, so that the possibility of the sewing failure can be predicted in a plurality of grades. Therefore, the failure prediction device can improve the accuracy of preventing the sewing failure.

In the failure prediction device according to claim 6, the acquisition unit may include at least one of a tension acquisition unit that acquires the tension of the upper thread and a movement amount acquisition unit that acquires a movement amount of the upper thread, and the variable may be at least one of the tension and the movement amount. The failure prediction means can easily acquire the variables. Therefore, the failure prediction device can easily prevent the sewing failure.

In the failure prediction device according to claim 7, the sewing failure may include a broken thread, and the prediction unit may predict the occurrence of the broken thread based on a transition of the characteristic amount per the unit, which is at least one of the tension and the movement amount. The failure prediction device can easily compare the transition of the feature amount. Therefore, the failure prediction device can prevent the occurrence of disconnection.

In the failure prediction device according to claim 8, the sewing failure may include a stitch skipping, and the prediction unit may predict the stitch skipping based on a transition of the feature amount per the unit, which is at least one of the tension and the movement amount as a transition of the feature amount. The failure prediction device can easily compare the transition of the feature amount. Therefore, the failure prediction device can prevent the occurrence of a stitch jump.

In the failure prediction device according to claim 9, the sewing failure may include a thread take-up failure, and the prediction unit may predict the occurrence of the thread take-up failure based on a transition of the characteristic amount per the unit of the characteristic amount, which is at least one of the tension and the movement amount. The failure prediction device can easily compare the transition of the feature amount. Therefore, the failure prediction device can prevent poor take-up.

In the failure prediction device according to claim 10, the sewing machine may include: a thread take-up lever for taking up the upper thread; and a shuttle configured to capture a loop of the upper thread inserted into the needle, wherein the predetermined timing is at least one of a period during which the thread take-up lever lifts the upper thread and a period during which the shuttle captures the loop of the upper thread and the shuttle passes from a loop drill of the upper thread, and the prediction unit predicts occurrence of a thread breakage when at least one of a transition of each unit of the characteristic amount of the tension in the predetermined timing tends to increase and a transition of each unit of the characteristic amount of the movement amount in the predetermined timing tends to decrease. When the characteristic quantities of the tension of the upper thread and the movement quantity of the upper thread in the period when the take-up lever lifts the upper thread and the period when the shuttle catches the loop of the upper thread and the shuttle passes through the loop drill of the upper thread are changed relative to the normal sewing, the sewing failure is easy to occur. The failure prediction device can improve the accuracy of preventing disconnection.

In the failure prediction device according to claim 11, the sewing machine may include a thread take-up lever that takes up the upper thread, and the prediction unit may predict the occurrence of a skip stitch when at least one of a tendency of transition of each unit of the characteristic amount of the tension during a period in which the thread take-up lever takes up the upper thread and a tendency of transition of each unit of the characteristic amount of the movement amount in the predetermined time takes up a decrease. When the characteristic quantity of the upper thread tension during the period that the take-up lever lifts the upper thread and the characteristic quantity of the upper thread moving quantity in the machine when the period of the vertical movement of the needle is regulated are changed relative to the normal sewing, the sewing failure is easy to occur. The failure prediction device can improve the accuracy of preventing a stitch jump.

In the failure prediction device according to claim 12, the sewing machine may include a shuttle that captures a loop of the upper thread inserted into the needle, and when the variable includes the tension, the prediction unit may predict the occurrence of a skip stitch when a transition of the characteristic amount of the tension in a period in which the thread take-up lever lifts the upper thread decreases for each unit and a transition of the characteristic amount of the tension in a period in which the shuttle captures the loop of the upper thread at the predetermined timing increases for each unit. When the characteristic amount of the upper thread tension during the time when the shuttle catches the upper thread loop and the shuttle passes through the loop drill of the upper thread changes relative to the normal sewing, the sewing failure is easy to occur. The failure prediction device can improve the accuracy of preventing a stitch jump.

In the failure prediction device according to claim 13, the sewing machine may include a thread take-up lever that takes up the upper thread, the predetermined timing may be a period during which the thread take-up lever takes up the upper thread, and the prediction unit may predict the occurrence of the thread take-up failure when at least one of a transition of each of the units of the characteristic amount of the tension in the predetermined timing tends to increase and a transition of each of the units of the characteristic amount of the movement amount in the predetermined timing tends to increase. When the characteristic quantity of the upper thread tension and the upper thread moving quantity in the period when the take-up lever lifts the upper thread changes relative to the normal sewing, the sewing failure is easy to occur. The poor prediction device can improve the precision of preventing receiving line badness.

In the failure prediction device according to claim 14, the sewing machine may include a driving unit that drives the sewing machine to sew the fabric during sewing, and the failure prediction device may include an avoidance control unit that executes avoidance control for controlling the driving unit to avoid the sewing failure when the prediction unit predicts the sewing failure. The failure prediction device can prevent the poor sewing by avoiding the avoiding control of the control part when the poor sewing is predicted.

In the failure prediction device according to claim 15, the drive unit of the sewing machine may include a needle bar drive unit that moves a needle bar to which the needle is attached up and down, and the avoidance control unit may reduce a drive speed of the needle bar drive unit as the avoidance control. By reducing the driving speed of the needle bar driving unit, the variation per unit of the characteristic amount is reduced. Therefore, the failure prediction device can improve the accuracy of preventing the sewing failure.

In the failure prediction device according to claim 16, the drive unit of the sewing machine may include: a needle bar driving part which enables the needle bar assembled with the machine needle to move up and down; and a thread tension mechanism for applying tension to the upper thread, wherein the avoidance control unit controls the tension applied by the thread tension mechanism in one cycle of the vertical movement of the needle as the avoidance control. The failure prediction device can control the upper thread tension periodically changed by the vertical movement of the needle, and the change of the characteristic quantity per unit is reduced. Therefore, the failure prediction device can improve the accuracy of preventing the sewing failure.

In the failure prediction device according to claim 17, the drive unit of the sewing machine may include: a needle bar driving part which enables the needle bar assembled with the machine needle to move up and down; and a thread tension mechanism that applies tension to the upper thread and adjusts a movement amount of the upper thread by rotational driving, wherein the avoidance control unit controls at least one of the tension applied by the thread tension mechanism and a variation in the movement amount in one cycle of vertical movement of the needle as the avoidance control. The failure prediction device can control the variation of the facial thread tension and facial thread movement amount which periodically vary due to the vertical movement of the needle, so that the variation of the characteristic amount per unit is reduced. Therefore, the failure prediction device can improve the accuracy of preventing the sewing failure.

In the failure prediction device according to claim 18, the failure prediction device may include a prediction stop unit that stops the drive unit when the prediction unit predicts that the sewing failure occurs after the avoidance control unit executes the avoidance control. The failure prediction device stops the driving part and stops sewing when the prediction part still predicts the poor sewing after executing the avoidance control. Therefore, the failure prediction device can prevent the occurrence of sewing failure when the unavoidable sewing failure is predicted.

In the failure prediction device according to claim 19, the sewing machine may include a driving unit that drives the sewing machine to sew the fabric during sewing, and the failure prediction device may include a thread breakage prediction stopping unit that stops the driving unit when the prediction unit predicts occurrence of the thread breakage. The failure prediction device stops the driving part and stops sewing when the occurrence of the broken thread is predicted, so that the broken thread can be prevented.

In the failure prediction device according to claim 20, the failure prediction device may further include a notification unit that notifies that the sewing failure is predicted when the prediction unit predicts that the sewing failure occurs. The failure prediction device informs the prediction of the sewing failure when the sewing failure is predicted, so that an operator can grasp the prediction of the sewing failure.

In the failure prediction device according to claim 21, the failure prediction device may further include a prediction level notification unit that notifies the prediction level identified by the prediction unit. The failure prediction device informs the prediction grade when the sewing failure is predicted, so that an operator can grasp the possibility degree of the sewing failure.

The failure prediction device according to claim 22 may further include an avoidance notification unit that notifies execution of the avoidance control when the avoidance control unit executes the avoidance control. The failure prediction device notifies the execution of the avoidance control when the avoidance control is executed, and therefore, the operator can grasp the case of avoidance when the occurrence of the sewing failure is predicted.

In the failure prediction device according to claim 23, the failure prediction device may include a stop notification unit that notifies the stop of the driving unit when the prediction stop unit stops the driving unit. The failure prediction device notifies the stop of the driving part when the failure in sewing is predicted and the driving part is stopped after the avoidance control is executed. Therefore, the failure prediction device enables the operator to grasp the case where the sewing is stopped due to the fact that the unavoidable sewing failure is predicted.

Drawings

Fig. 1 is a perspective view of the sewing machine 1.

Fig. 2 is a partially enlarged view of the nose portion 5.

Fig. 3 is a perspective view of the tension detection mechanism 18.

Fig. 4 is an electrical block diagram of the sewing machine 1.

Fig. 5 is a schematic diagram showing a flow of the hook 49 catching the upper thread 66.

FIG. 6 is a graph showing the varying tension during the sewing period for one stitch.

Fig. 7 is a graph showing the fluctuating tension before the occurrence of the disconnection.

Fig. 8 is a graph showing the varying tension before the skip stitch occurs.

Fig. 9 is a graph showing a varying tension before a take-up failure occurs.

FIG. 10 is a graph showing the amount of movement of a needle during sewing.

Fig. 11 is a graph showing the variation of the first tension in units of prediction units.

Fig. 12 is a flowchart of the first sewing process.

Fig. 13 is a flowchart following the first sewing process of fig. 12.

Fig. 14 is a flowchart of the first feature quantity processing.

Fig. 15 is a flowchart of the first disconnection prediction processing.

Fig. 16 is a flowchart of the disconnection avoiding process.

Fig. 17 is a flowchart of the first skip prediction processing.

Fig. 18 is a flowchart of the skip stitch avoidance process.

Fig. 19 is a flowchart of the first wire rewinding failure prediction process.

Fig. 20 is a flowchart of a process for avoiding poor wire take-up.

Fig. 21 is a flowchart of the prediction stop processing.

Fig. 22 is a partial flowchart of the second sewing process.

Fig. 23 is a flowchart of the second feature quantity processing.

Fig. 24 is a flowchart of the second disconnection prediction processing.

Detailed Description

A sewing machine 1 according to an embodiment of the present invention will be described with reference to the drawings. The following description uses the left and right, front and back, and up and down indicated by arrows in the drawings.

Referring to fig. 1 to 3, the structure of the sewing machine 1 will be described. As shown in fig. 1, the sewing machine 1 includes a bed portion 2, a column portion 3, and a arm portion 4. The upper surface of the base portion 2 has a needle plate 7. The needle plate 7 has a needle receiving hole 8 and a feed dog hole 14 at the center thereof. The feed sprocket holes 14 are located at the left, rear, right and front of the needle accommodating hole 8, respectively.

The column part 3 extends upward from the right end of the seat part 2. The arm portion 4 extends leftward from the upper end of the column portion 3. The front surface of the arm portion 4 has an input portion 24 and a display portion 25 at a substantially central portion in the left-right direction. The input unit 24 is three buttons arranged in the vertical direction. The display unit 25 displays various information. The operator operates the input unit 24 while looking at the display unit 25 to input various instructions. The arm portion 4 has a bobbin 20 projecting upward on the left side of the upper surface. The upper thread 66 (see fig. 2) fed from the bobbin is inserted into the bobbin 20. The upper thread 66 is formed by twisting a plurality of threads.

The arm portion 4 includes an upper shaft 15 and a main motor 27 (see fig. 4) therein. The upper shaft 15 extends in the left-right direction and is connected to an output shaft of the main motor 27 via an upper shaft pulley. The upper shaft belt wheel is fixed at the right end of the upper shaft 15. The upper shaft 15 is rotated by the power of the main motor 27. The left end of the arm portion 4 has a nose portion 5. The nose portion 5 protrudes downward from the arm portion 4 and faces the needle plate 7 from above. The head unit 5 supports the needle bar 11 so that the needle bar 11 can move up and down. The lower end of the needle bar 11 protrudes downward from the head portion 5. The needle bar 11 is connected to the upper shaft 15 by an up-and-down movement mechanism. The needle bar 11 moves up and down along with the rotation of the upper shaft 15. A needle 10 is fitted to the lower end of the shank 11. The needle 10 holds the needle thread 66 inserted in the eye 10A (see fig. 5). The needle 10 moves up and down together with the needle bar 11. The needle 10 can pass through the needle receiving hole 8. The upper end of the movable range of the needle 10 is a top dead center, and the lower end of the movable range of the needle 10 is a bottom dead center.

The base unit 2 includes a shuttle 49 (see fig. 5), a thread cutting mechanism 17 (see fig. 4), and a cloth feeding mechanism. The shuttle 49 is provided below the needle plate 7, and houses a bobbin around which a lower thread 67 (see fig. 5) is wound. The shuttle 49 has a shuttle tip 46 (see fig. 5). The shuttle 49 is rotated by the power of the main motor 27, and the shuttle 49 catches the upper thread 66 inserted into the needle 10 by the tip 46, and the upper thread 66 and the lower thread 67 are interlaced. The thread cutting mechanism 17 includes a fixed blade, a movable blade, and an electromagnetic element 17A (see fig. 4). The movable blade is connected to the electromagnetic element 17A. The movable knife is moved relative to the fixed knife by the driving of the electromagnetic element 17A. The thread cutting mechanism 17 cuts the upper thread 66 and the lower thread 67 by the cooperation of the movable blade and the fixed blade. The cloth feeding mechanism includes a cloth feeding tooth 13 and a cloth feeding motor 28 (see fig. 4). The feed dog 13 is located below the needle plate 7. The cloth feeding teeth 13 are moved in the front-rear direction by the power of the cloth feeding motor 28, and moved in the up-down direction by the power of the main motor 27. At this time, the feed dog 13 protrudes and sinks in at the feed dog hole 14. The cloth feed dog 13 moves in the front-rear direction while protruding upward from the cloth feed dog hole 14, and feeds the cloth 69.

As shown in fig. 2, the head section 5 has a sub-gripper 26, a main gripper 22, a thread guide 21, a tension detecting mechanism 18, a thread take-up lever 23, and a guide hook 29 in this order from the upstream side of the feed path of the upper thread 66 from the bobbin to the needle 10. The sub-chuck 26 is located at the upper right of the front surface of the nose part 5. The main gripper 22 is located below the sub gripper 26. The sub-gripper 26 and the main gripper 22 respectively give tension to the upper thread 66. The sub-gripper 26 applies a tension to the upper thread 66, which is required when the upper thread 66 and the lower thread 67 are cut by the thread cutting mechanism 17. The main gripper 22 includes a thread tension motor 16 (see fig. 4), and the main gripper 22 applies tension to the upper thread 66 by driving the thread tension motor 16. The main thread tension device 22 optimizes the tension acting on the upper thread 66 (hereinafter referred to as upper thread tension) and the amount of the upper thread 66 to be fed to the downstream side of the feed path (hereinafter referred to as upper thread moving amount) in accordance with the sewing of the sewing machine 1. The wire guide 21 is to the left of the main gripper 22. The thread guide 21 guides the upper thread 66 after passing through the main thread catcher 22 so as to be folded back toward the tension detecting mechanism 18 and the thread take-up lever 23.

The tension detection mechanism 18 is located in a recess 5A recessed rearward from the front surface of the nose 5. The tension detecting mechanism 18 is located at a position in the up-down direction between the sub-gripper 26 and the main gripper 22. The tension detecting mechanism 18 can detect the face line tension. The thread take-up lever 23 is located to the left of the sub-gripper 26. The thread take-up lever 23 has a through hole 23A through which the upper thread 66 is inserted. The thread take-up lever 23 moves up and down in accordance with the driving of the main motor 27. The guide hook 29 is on the left of the tension detection mechanism 18. The guide hook 29 guides the needle thread 66 after passing through the through hole 23A toward the needle bar 11.

As shown in fig. 3, the tension detecting mechanism 18 has a mount 51, a holding portion 52, a magnetic sensor 53, a plate 54, a guide member 55, and a magnet 56. The mount base 51 has a mounting portion 57 and a base portion 59. The mounting portion 57 and the base portion 59 are integrally formed with each other. The mounting portion 57 has a long hole 58 through which a screw is inserted. A screw inserted into the elongated hole 58 is fastened to a screw hole provided in the recess 5A. The base portion 59 is on the left side of the mount 51. The base portion 59 has a left projection 60 and a right projection 61. Each of the left and right protruding portions 60, 61 has a rectangular parallelepiped shape extending in the front-rear direction. The holding portion 52 is a nonmagnetic body and has a substantially rectangular parallelepiped shape, and the holding portion 52 is attached to the base portion 59 between the left protruding portion 60 and the right protruding portion 61. The magnetic sensor 53 is a hall element, and is held by the front surface of the holding portion 52. The magnetic sensor 53 is positioned rearward of the front ends of the left projection 60 and the right projection 61.

The plate 54 has a plate shape having a thickness in the front-rear direction, and is bridged between a left projection 60 and a right projection 61. The guide member 55 is mounted to the left projection 60 and the right projection 61. The guide member 55 sandwiches the left end portion of the plate 54 between it and the left projection 60, and sandwiches the right end portion of the plate 54 between it and the right projection 61. A gap is provided between the center portion of the plate 54 in the left-right direction and the front surface of the holding portion 52. Therefore, the plate 54 is flexed in the front-rear direction with both ends in the left-right direction as fulcrums. The magnet 56 has a cylindrical shape extending in the front-rear direction, and the magnet 56 is fixed to the rear surface of the left-right direction center portion of the plate 54. When the plate 54 is flexed in the front-rear direction, the magnet 56 moves forward and backward, and the distance between the magnet 56 and the magnetic sensor 53 changes. The magnetic sensor 53 detects a change in magnetic flux density from the magnet 56, and outputs a voltage according to the magnetic flux density.

The guide member 55 has an upper guide groove 63 and a lower guide groove 65. The upper guide groove 63 and the lower guide groove 65 are aligned in the up-down direction with the plate 54 interposed therebetween. The upper guide groove 63 and the lower guide groove 65 are open in the vertical direction and are hook-shaped. The upper guide groove 63 has an upper holding hole 62, and the lower guide groove 65 has a lower holding hole 64. The upper holding hole 62 and the lower holding hole 64 are through holes that are opened in the vertical direction. The upper thread 66 is inserted through the upper and lower holding holes 62 and 64, respectively. The face wire 66 between the upper holding hole 62 and the lower holding hole 64 is in contact with the plate 54 from the front. When the tension of the needle thread increases, the needle thread 66 applies a force to the plate 54 in the rearward direction. The magnetic sensor 53 outputs a voltage corresponding to the position in the forward/backward direction of the plate 54 that is deflected in the forward/backward direction by the tension of the upper thread. The sewing machine 1 can obtain the upper thread tension from the output voltage of the magnetic sensor 53.

As shown in fig. 2, the head unit 5 has a head unit amplifier 70. The nose amplifier 70 is located on the rear upper surface of the nose 5. The head amplifier 70 has a disconnection LED71, a jumper LED72, and a defective wire take-up LED73, which are full-color LEDs capable of emitting light, provided in this order from the right on the front surface. The thread breakage LED71 emits light when the sewing machine 1 predicts the occurrence of thread breakage. The skip stitch LED72 emits light when the sewing machine 1 predicts the occurrence of a skip stitch. The poor take-up LED73 emits light when the sewing machine 1 predicts that poor take-up occurs. The poor sewing of broken thread, skipping stitch and take-up thread is one of the poor sewing. The details of the defective sewing will be described later.

Referring to fig. 4, an electrical structure of the sewing machine 1 is explained. The control device 90 of the sewing machine 1 includes a CPU91, a ROM92, a RAM93, a storage device 94, an input/output interface (hereinafter referred to as an input/output unit) 95, and drive circuits 81 to 86. The CPU91 is connected to the ROM92, the RAM93, the storage device 94, and the input/output section 95, respectively. The CPU91 controls the sewing machine 1, and executes processing such as a first sewing process (see fig. 12) described later and various calculations in accordance with various programs. The ROM92 stores various programs, various initial setting parameters, detection thresholds described later, and the like. The RAM93 temporarily stores the operation result, count, and the like of the CPU 91. The storage device 94 stores various setting information and the like input by the operator.

The input/output unit 95 is connected to the drive circuits 81 to 86, the speaker 39, the input unit 24, the pedal 38, and the magnetic sensor 53, respectively. The drive circuit 81 is connected to the main motor 27. The main motor 27 has an encoder 27A. The encoder 27A detects the rotational position of the output shaft of the main motor 27. That is, the detection result of the encoder 27A indicates the rotation angle phase of the upper shaft 15, that is, the upper shaft angle. The encoder 27A transmits the detection result to the CPU91 via the input/output unit 95. The drive circuit 82 is connected to the cloth feed motor 28.

The drive circuit 83 is connected to the clamp motor 16. The clamp motor 16 has an encoder 16A. The encoder 16A detects the rotational position of the output shaft of the clamp motor 16. The encoder 16A transmits the detection result to the CPU91 via the input/output unit 95. The CPU91 acquires the upper thread moving amount from the detection result of the encoder 16A. Hereinafter, the main motor 27, the cloth feeding motor 28, and the thread take-up motor 16 are collectively referred to as a driving section. The CPU91 controls the driving section via the driving circuits 81-83.

The drive circuit 84 is connected to the wire cutting mechanism 17. The CPU91 controls the electromagnetic element 17A of the wire cutting mechanism 17 via the drive circuit 84. The driving circuit 85 is connected to the display unit 25. The CPU91 controls the display section 25 via the drive circuit 85. The drive circuit 86 is connected to the head amplifier 70. The CPU91 controls the disconnection LED71, the jumper pin LED72, and the poor wire take-up LED73 by means of the drive circuit 86, respectively. The speaker 39 outputs various sounds by the control of the CPU 91. The input unit 24 outputs various instructions input by the operator to the CPU 91. The pedal 38 outputs to the CPU91 respective detection results of an operation direction and an operation amount obtained in accordance with an operation of the pedal 38 by the operator. The magnetic sensor 53 outputs an output voltage indicating the face line tension to the CPU 91.

Referring to fig. 1 and 5, the schematic operation of the sewing machine 1 will be described. The operator places the cloth 69 on the needle plate 7. The main motor 27 is driven by the operator operating the pedal 38 in a predetermined direction. The upper shaft 15 is rotated by the driving of the main motor 27, and the needle bar 11 and the thread take-up lever 23 are moved up and down. The shuttle 49 rotates in synchronism with the rotation of the upper shaft 15. The needle 10, which descends together with the shank 11, penetrates the cloth 69 and passes through the needle receiving opening 8. The upper thread 66 that has descended to the vicinity of the needle eye 10A below the needle accommodating hole 8 is formed in a ring shape (see fig. 5 (a)). The shuttle 49 rotates clockwise in the main view, and the loop-shaped upper thread 66 is caught by the shuttle point 46 (see fig. 5 b). The needle 10 is raised upward toward the cloth 69, and the shuttle 49 continues to rotate clockwise in the front view. The hook 46 pulls the endless upper thread 66 in the rotational direction, and the endless upper thread 66 expands in diameter. When the shuttle 49 passes through the endless needle thread 66 (see fig. 5 c), the needle thread 66 is interlaced with the base thread 67. Hereinafter, the period during which the loop-shaped needle thread 66 is caught by the hook tip 46 and the hook 49 has drilled from the loop-shaped needle thread 66 is referred to as a hook catching period. The rotational direction of the shuttle 49 is switched to the counterclockwise direction in the main view. At this time, the thread take-up lever 23 lifts up the upper thread 66 interlaced with the lower thread 67 (see fig. 5 (d)). Hereinafter, the period during which the thread take-up lever 23 lifts the upper thread 66 is referred to as a thread take-up lever lifting period. The annular upper thread 66 is reduced in diameter, and the sewing machine 1 completes the sewing by one needle. In the present embodiment, the sewing machine 1 performs the sewing by one stitch every time the upper shaft 15 rotates one turn. The sewing machine 1 repeats the above-described operation to form a plurality of stitches 68 on the cloth 69.

The sewing failure of the sewing machine 1 will be described. The sewing failure indicates a case where the normal stitch 68 is not formed in the course of the sewing operation. The sewing defects comprise broken threads, jumpers and take-up defects. The thread breakage is a defect that the upper thread 66 is broken during sewing and a stitch 68 is not formed on the cloth 69. The skip stitch is a defect in which the upper thread 66 is not caught by the shuttle 49 during sewing, and the upper thread 66 and the lower thread 67 are not interlaced to form a normal stitch 68 on the cloth 69. The poor take-up is a poor balance between the upper thread 66 and the lower thread 67 forming a stitch 68 on the cloth 69 when the upper thread 66 is lifted by the thread take-up lever 23. For example, when the upper thread 66 is too strongly interlaced with the lower thread 67, the thread take-up lever 23 is not completely lifted up when lifting up the upper thread 66, and the position where the upper thread 66 is interlaced with the lower thread 67 is deviated from an appropriate position.

Changes in the needle thread tension and the needle thread movement amount before the sewing failure occurs will be described with reference to fig. 6 to 10. The CPU91 acquires the needle thread tension based on the detection result of the magnetic sensor 53, the needle thread movement amount based on the detection result of the encoder 16A, and the upper axis angle based on the detection result of the encoder 27A, respectively. As shown in fig. 6 and 10 (a), the upper thread tension, the upper thread movement amount, and the upper axis angle periodically vary in a unit of sewing period at the time of sewing. The sewing period is a period during which the sewing machine 1 performs sewing by one stitch. Hereinafter, the upper thread tension that periodically varies is referred to as a variation tension, and the upper thread movement amount that periodically varies is referred to as a variation movement amount. During a sewing period of one stitch (one cycle) based on the top dead center of the needle 10 (the upper axis angle is 0 degrees), a take-up lever raising period and a shuttle catching period occur in this order. At an upper axis angle H1 (about 70 degrees) during the take-up lever lifting, a first vertex of a varying tension during sewing occurs. At upper axis angle H2 (about 330 degrees) during shuttle capture, the second vertex of the fluctuating tension during sewing occurs. The CPU91 determines the thread take-up lever lifting period and the shuttle catching period based on the upper axis angle obtained based on the detection result of the encoder 27A.

The change in the tension and the amount of movement of the tension fluctuation before the occurrence of the disconnection will be described. The untwisting of the upper thread 66 strands occurs during sewing before the thread breakage occurs. The loose twist of the upper thread 66 generates a twist movement which moves together with the upper thread 66 during sewing. When the twist occurs, the strands of the upper thread 66 are accumulated, and the strands cannot smoothly move at the position where the upper thread 66 is bent such as the thread take-up lever 23, and the bending resistance increases. Therefore, as shown in fig. 7, the maximum value of the needle thread tension during the raising of the thread take-up lever (hereinafter referred to as the first tension) and the maximum value of the needle thread tension during the catching of the shuttle (hereinafter referred to as the second tension) are both larger than those in the normal state. When the first tension and the second tension are increased to the limit, the wire breakage occurs. When the twist shift occurs and the strands of the upper thread 66 are accumulated, the upper thread 66 is stretched by the increased tension of the upper thread. At this time, the upper thread moving amount supplied to the needle 10 is reduced by the amount corresponding to the stretching of the upper thread 66. Therefore, as shown in fig. 10 (b), when a thread breakage occurs, both the needle thread movement amount at the upper axis angle H1 (hereinafter referred to as a first movement amount) and the needle thread movement amount at the upper axis angle H2 (hereinafter referred to as a second movement amount) become smaller than those in the normal state.

The change in the tension and the amount of movement of the stitch before the stitch jump occurs will be described. The untwisting of the upper thread 66 accumulated at the position where the upper thread 66 is bent may move. At this time, the loose twist of the upper thread 66 is difficult to pass through the needle receiving hole 8. The needle thread 66 is accumulated above the needle accommodating hole 8, and the needle thread moving amount is reduced. Therefore, as shown in fig. 10 c, the needle thread movement amount (hereinafter referred to as a third movement amount) at the top dead center (the upper axis angle is 360 degrees) of the needle 10 becomes smaller than that in the normal state. Since the loose twist portion of the needle thread 66 hardly passes through the needle accommodating hole 8, the annular needle thread 66 below the needle accommodating hole 8 is not expanded in diameter as compared with the normal case. The upper thread 66 cannot be caught by the shuttle 49, and a needle skip occurs. When the twist occurs, the untwisted portion of the upper thread 66 hardly passes through the needle accommodating hole 8, and therefore, the tension by which the shuttle 49 pulls the upper thread 66 below the needle accommodating hole 8 becomes large, and the tension by which the thread take-up lever 23 pulls the upper thread 66 above the needle accommodating hole 8 becomes small. Therefore, as shown in fig. 8, when the stitch skipping occurs, the first tension becomes smaller than that in the normal state, and the second tension becomes larger than that in the normal state.

The change in the tension and the amount of movement before the wire take-up failure occurs will be described. The loose twist of the needle thread 66 is accumulated at the position where the needle thread 66 is bent, and is twisted into a spiral shape. The twisted upper thread 66 may move, and the hook 49 catches the twisted upper thread 66. When the shuttle 49 passes through the twisted upper thread 66, the twisted upper thread 66 is twisted and interlaced with the lower thread 67 in a whirling manner about the lower thread 67 by the force generated by the twisting. The thread take-up lever 23 lifts the upper thread 66 interlaced with the lower thread 67. Therefore, as shown in fig. 9, the first tension becomes larger than that in the normal state. At this time, the face line 66 moves more than normal. Therefore, as shown in fig. 10 (d), the first movement amount becomes larger than that in the normal state. When the first movement amount is larger than the normal amount, the thread take-up lever 23 cannot be completely lifted up when lifting up the upper thread 66, resulting in poor balance between the upper thread 66 and the lower thread 67, and poor take-up.

When sewing, before a sewing failure occurs, the first tension, the second tension, the first movement amount, the second movement amount, and the third movement amount are changed from those in a normal state. The amount of the characteristic indicating the occurrence of the sewing failure, which varies before the occurrence of the sewing failure, is referred to as a characteristic amount. The first tension, the second tension, the first movement amount, the second movement amount, and the third movement amount are examples of the characteristic amount.

The sewing machine 1 predicts the occurrence of sewing failure based on the transition of the feature quantity in units of prediction units. The prediction unit is a sewing period of one cycle or more. The sewing machine 1 acquires the feature values in each prediction unit. The sewing machine 1 stores the feature quantities in the RAM93 in the order of acquisition. As shown in fig. 11, when the sewing period of one stitch is used as a prediction unit, the first tension as the characteristic amount varies in the order of acquisition. When the feature amount is continuously increased five times in units of prediction units, the transition called the feature amount tends to increase. When the feature amount is continuously decreased five times in units of prediction units, the transition called feature amount tends to decrease.

When the sewing failure is predicted, the sewing machine 1 notifies the head amplifier 70 that the sewing failure is predicted. When the sewing machine 1 predicts the occurrence of thread breakage, it gives a notification by emitting light to the thread breakage LED 71. When the occurrence of a stitch skipping is predicted, the sewing machine 1 causes the stitch skipping LED72 to emit light to notify. When the sewing machine 1 predicts the occurrence of the poor thread take-up, the poor thread take-up LED73 is lighted to notify. When the sewing machine 1 continuously predicts that sewing failure occurs for a predetermined number of times, the sewing machine 1 changes the colors of the light emission of the thread breakage LED71, the stitch skipping LED72, and the thread take-up failure LED 73.

The sewing machine 1 executes avoidance control for avoiding the occurrence of poor sewing when the occurrence of poor sewing is predicted. The sewing machine 1 is controlled to avoid the above-mentioned problem by reducing the rotation speed of the main motor 27 and reducing the upper thread tension applied to the main thread gripper 22. At this time, the sewing machine 1 outputs a sound from the speaker 39 to inform the execution of the avoidance control. The sewing machine 1 stops the driving section and stops sewing when the occurrence of poor sewing is repeatedly predicted after the avoidance control is executed. At this time, the sewing machine 1 changes the color of light emission of the thread breakage LED71, the stitch skipping LED72, and the thread take-up failure LED73 to a color different from that at the time when the occurrence of a sewing failure is predicted, and outputs a sound from the speaker 39 to notify the stop of the sewing.

The first sewing process of the sewing machine 1 will be described with reference to fig. 12 to 21. When the operator turns on the power of the sewing machine 1, the CPU91 reads the program from the ROM92 and starts the first sewing process. In the first sewing process, the CPU91 predicts the occurrence of a sewing failure in units of a sewing period of one stitch as a prediction unit. The first tension, the second tension, the first movement amount, the second movement amount, and the third movement amount are characteristic amounts of the first sewing process. The CPU91 predicts that a wire break occurs when the first tension and the second tension tend to increase or when the first movement amount and the second movement amount tend to decrease. The CPU91 predicts the occurrence of a stitch jump when the first tension is in a decreasing trend and the second tension is in an increasing trend, or when the third movement amount is in a decreasing trend. The CPU91 predicts the occurrence of a wire rewinding failure when the first tension is on an increasing trend or when the first movement amount is on an increasing trend.

The flag and the count used by the CPU91 in the first sewing process will be described. The RAM93 stores a disconnection prediction stop flag, a skip prediction stop flag, a wire-reception failure prediction stop flag, and the like. The thread breakage prediction stop flag is set to 1 when the CPU91 repeatedly predicts the occurrence of thread breakage and stops sewing. The skip stitch prediction stop flag is set to 1 when the CPU91 repeatedly predicts that a skip stitch occurs and stops sewing. The thread take-up failure prediction stop flag is set to 1 when the CPU91 repeatedly predicts that a thread take-up failure has occurred and stops sewing. When the first sewing process is started, the predicted stop sign for broken thread, the predicted stop sign for skip stitch, and the predicted stop sign for defective take-up are all 0.

The RAM93 stores a disconnection prediction count U, a skip stitch prediction count V, a winding failure prediction count W, a needle fall number N, an accumulated needle fall number L, and the like. The disconnection prediction count U is added to a value of 1 when the CPU91 predicts that a disconnection has occurred. The skip-stitch prediction count V is incremented by 1 when the CPU91 predicts the occurrence of a skip stitch. The wire-rewinding failure prediction count W is added to 1 when the CPU91 predicts that a wire-rewinding failure has occurred. The CPU91 determines that: the larger the values of the thread breakage prediction count U, the stitch skipping prediction count V, and the thread take-up failure prediction count W are, the higher the possibility of occurrence of sewing failure is. The CPU91 stops sewing when the occurrence of thread breakage is continuously predicted and the predicted thread breakage count U reaches the predicted thread breakage stop count X. The CPU91 stops sewing when the occurrence of stitch skipping is continuously predicted and the stitch skipping prediction count V reaches the stitch skipping prediction stop number Y. The CPU91 stops sewing when the poor take-up is predicted continuously and the poor take-up prediction count W reaches the poor take-up prediction stop number Z.

The needle drop number N is the number of times the needle bar 11 moves up and down from the start of sewing to the stop of sewing, and is the number of times the sewing is repeated for one needle. The cumulative needle fall count L is the cumulative number of times the needle bar 11 moves up and down from the time when the power of the sewing machine 1 is turned on to the time when the power is turned off. When the first sewing process is started, the values of the thread breakage prediction count U, the stitch skipping prediction count V, the thread take-up failure prediction count W, the needle fall number N, and the accumulated needle fall number L are all 0.

As shown in fig. 12, the CPU91 executes initialization processing (S1). The CPU91 sets the wire breakage prediction stop flag, the skip stitch prediction stop flag, and the wire collection failure prediction stop flag to 0, respectively. The CPU91 sets the values of the disconnection prediction count U, the skip stitch prediction count V, the take-up failure prediction count W, and the number of dropped stitches N to 0. The CPU91 ends the notification when any one of a wire breakage prediction stop notification, a needle skipping prediction stop notification, and a wire collection failure prediction stop notification, which will be described later, is notified.

The CPU91 determines whether or not the X setting instruction signal is received from the input unit 24 (S4). The operator operates the input unit 24 when setting the estimated number of disconnection stops X. The input unit 24 outputs an X setting instruction signal to the CPU 91. When determining that the X setting instruction signal is not received from the input unit 24 (S4: no), the CPU91 proceeds to S6. When determining that the X setting instruction signal is received from the input unit 24 (yes in S4), the CPU91 sets the estimated number of disconnections to stop X (S5), and proceeds to S6.

The CPU91 determines whether or not the Y setting instruction signal is received from the input unit 24 (S6). The operator operates the input unit 24 when setting the number Y of stitch skipping prediction stops. The input unit 24 outputs a Y setting instruction signal to the CPU 91. When determining that the Y setting instruction signal is not received from the input unit 24 (S6: no), the CPU91 proceeds to S8. When determining that the Y setting instruction signal is received from the input unit 24 (yes in S6), the CPU91 sets the number of skip needle prediction stops Y (S7), and proceeds to S8.

The CPU91 determines whether or not the Z setting instruction signal is received from the input unit 24 (S8). The operator operates the input unit 24 when setting the estimated number of wire-rewinding stops Z. The input unit 24 outputs a Z setting instruction signal to the CPU 91. When determining that the Z setting instruction signal is not received from the input unit 24 (S8: no), the CPU91 proceeds to S11. When determining that the Z setting instruction signal is received from the input unit 24 (yes in S8), the CPU91 sets the estimated number of wire rewinding failure stops Z (S9) and proceeds to S11.

The CPU91 determines whether sewing is started based on the detection result of the pedal 38 (S11). When the operator does not operate pedal 38 in a predetermined direction, pedal 38 outputs an off signal. Upon receiving the close signal from the pedal 38, the CPU91 determines that sewing is not to be started (S11: no), and returns the process to S4. The operator places the cloth 69 on the needle plate 7. When the operator operates pedal 38 in a predetermined direction after cloth 69 is placed, pedal 38 outputs an on signal. When receiving the on signal from the pedal 38, the CPU91 determines that the sewing operation is started (yes in S11), and starts driving the driving unit (S13) to start sewing the cloth 69. The CPU91 shifts the process to S21 (see fig. 13). As shown in fig. 13, the CPU91 executes the first feature amount processing (S21). The first feature amount processing is processing of acquiring a feature amount.

Referring to fig. 14, the first feature amount processing is explained. The CPU91 acquires the varied tension and the varied movement amount from the detection result of the encoder 27A, the detection result of the magnetic sensor 53, and the detection result of the encoder 16A, and stores them in the RAM93 (S51). The CPU91 determines whether the acquired upper shaft angle is within the take-up lever lifting period (S52). When the CPU91 determines that the upper shaft angle is not within the thread take-up lever lifting period (S52: no), the CPU91 shifts the process to S55. When the CPU91 determines that the upper shaft angle is within the take-up lever lifting period (S52: yes), the CPU91 acquires the first tension based on the detection result of the magnetic sensor 53 and stores it in the RAM93 (S53). The CPU91 acquires the first movement amount based on the detection result of the encoder 16A and stores it to the RAM93 (S54). The CPU91 shifts the process to S55.

The CPU91 determines whether the upper axis angle is within the shuttle capturing period (S55). When the CPU91 determines that the upper axis angle is not within the shuttle capturing period (S55: no), the CPU91 shifts the process to S58. When the CPU91 determines that the upper axis angle is within the shuttle capturing period (S55: yes), the CPU91 acquires the second tension based on the detection result of the magnetic sensor 53 and stores it in the RAM93 (S56). The CPU91 acquires the second movement amount based on the detection result of the encoder 16A and stores it to the RAM93 (S57). The CPU91 shifts the process to S58.

The CPU91 determines whether the needle 10 is at the top dead center (S58). When the upper shaft angle is not 360 degrees and the CPU91 determines that the needle 10 is not at the top dead center (S58: no), the CPU91 returns the process to the first sewing process (see fig. 13). When the CPU91 determines that the needle 10 is at the top dead center with the upper shaft angle of 360 degrees (S58: yes), the CPU91 acquires the third movement amount based on the detection result of the encoder 16A and stores it in the RAM93 (S59). The CPU91 sets the size of the upper thread moving amount to 0(S60) and returns the processing to the first sewing processing.

As shown in fig. 13, after the first feature amount processing is performed (S21), the CPU91 determines whether the needle 10 is at the top dead center (S22). S22 is the same process as S58 (see fig. 14). When the CPU91 determines that the needle 10 is not at the top dead center (S22: no), the CPU91 determines whether sewing is finished based on the detection result of the pedal 38 (S23). When receiving the open signal from the pedal 38, the CPU91 determines not to end sewing (S23: no), and returns the process to S21.

The CPU91 repeatedly executes S21 to S23. When the CPU91 determines that the hand 10 is at the top dead center (yes in S22), the CPU91 adds 1 to the values of the needle count N and the cumulative needle count L (S31). The CPU91 determines whether the needle count N is 5 or more (S33). When the CPU91 determines that the needle number N is less than 5 (S33: no), the CPU91 determines that the sewing failure is not predictable, and shifts the process to S23. When the CPU91 determines that the needle count N is 5 or more (S33: yes), the CPU91 acquires five feature amounts newly stored in each feature amount stored in the RAM93 (S34). The CPU91 executes the first disconnection prediction process (S35), the first skip stitch prediction process (S36), and the first wire-collection failure prediction process (S37), and advances the process to S38.

Referring to fig. 15, the first disconnection prediction processing will be described. The first disconnection prediction processing is processing for predicting the occurrence of disconnection. The CPU91 determines whether the first tension is in an increasing trend based on the five first tensions acquired through S34 (refer to fig. 13) (S61). When the CPU91 determines that the first tension is not in the increasing tendency (S61: no), the CPU91 shifts the process to S63. When the CPU91 determines that the first tension is in the increasing trend (S61: yes), the CPU91 determines whether the second tension is in the increasing trend based on the five second tensions acquired through S34 (S62). When the CPU91 determines that the second tension is not in the increasing tendency (S62: no), the CPU91 shifts the process to S63. When the CPU91 determines that the second tension is in the increasing trend (S62: yes), the CPU91 shifts the process to S71.

The CPU91 determines whether the first movement amount is on the decreasing trend based on the five first movement amounts acquired through S34 (S63). When the CPU91 determines that the first movement amount does not exhibit the decreasing tendency (S63: no), the CPU91 shifts the process to S81. When the CPU91 determines that the first movement amount is in the decreasing trend (S63: yes), the CPU91 determines whether the second movement amount is in the decreasing trend based on the five second movement amounts acquired through S34 (S64). When the CPU91 determines that the second movement amount does not exhibit the decreasing tendency (S64: no), the CPU91 shifts the process to S81. When the CPU91 determines that the second movement amount is on the decreasing trend (S64: yes), the CPU91 shifts the process to S71.

When the CPU91 determines that the first tension and the second tension tend to increase (yes in S62), or when the CPU91 determines that the first movement amount and the second movement amount tend to decrease (yes in S64), the CPU91 predicts the occurrence of a wire break and adds 1 to the value of the wire break prediction count U (S71). The CPU91 determines whether the value of the disconnection prediction count U is smaller than the disconnection prediction stop number X (S72). When the CPU91 determines that the value of the predicted disconnection count U is smaller than the predicted number of times of stoppage X of disconnection (S72: yes), the CPU91 performs a disconnection avoidance process (S73) and returns the process to the first sewing process (see fig. 13).

Referring to fig. 16, the disconnection avoiding process is explained. The disconnection avoiding process is a process for avoiding the occurrence of a disconnection when the occurrence of a disconnection is predicted. The CPU91 determines whether the value of the disconnection prediction count U is 1 (S91). When the CPU91 determines that the value of the disconnection prediction count U is 1 (S91: yes), the CPU91 outputs a sound from the speaker 39 to execute a disconnection avoidance notification notifying that the execution of the avoidance control is notified (S92). The CPU91 reduces the rotation speed of the main motor 27 (S93), controls the thread tension motor 16 to reduce the thread tension applied by the main gripper 22 (S94), and shifts the process to S101. When the occurrence of a wire break is continuously predicted and the CPU91 determines that the value of the wire break prediction count U is greater than 1 (S91: no), the CPU91 regards the avoidance control as being executed, and shifts the process to S101.

The CPU91 determines whether or not the value of the predicted disconnection count U is equal to or greater than half the predicted disconnection stop number X (S101). When the occurrence of a disconnection is continuously predicted, the CPU91 notifies the prediction of the occurrence of a disconnection in a plurality of levels according to the number of times the prediction is continued (the value of the disconnection prediction count U). When the CPU91 determines that the value of the disconnection prediction count U is less than half the number X of disconnection prediction stops (S101: no), the CPU91 executes a first disconnection prediction notification (S102) and returns the process to the first disconnection prediction process (see fig. 15). When the first disconnection prediction is notified, the CPU91 causes the disconnection LED71 to emit yellow light. When the CPU91 determines that the value of the disconnection prediction count U is equal to or greater than half the number X of disconnection prediction stops (yes in S101), the CPU91 executes a second disconnection prediction notification (S103), and returns the process to the first disconnection prediction process. When the second disconnection prediction is notified, the CPU91 makes the disconnection LED71 emit orange light.

As shown in fig. 15, when the CPU91 determines that either one of the first tension and the second tension does not tend to increase (S61: no or S62: no) and either one of the first movement amount and the second movement amount does not tend to decrease (S63: no or S64: no), the CPU91 determines that the occurrence of a wire break is not predicted, and shifts the process to S81. The CPU91 determines whether the value of the disconnection prediction count U is 1 or more (S81). When the CPU91 determines that the value of the disconnection prediction count U is 1 or more (S81: yes), the CPU91 ends the first disconnection prediction notification (see S102 and fig. 16) and the second disconnection prediction notification (see S103 and fig. 16), and turns off the disconnection LED71 (S82). The CPU91 ends the disconnection avoidance notification (see S92 and fig. 16), and stops the sound output from the speaker 39 (S83). The CPU91 increases the rotation speed of the main motor 27 to the rotation speed before being decelerated by S93 (refer to fig. 16) (S84). The CPU91 controls the thread tension motor 16 to increase the magnitude of the needle thread tension applied by the main thread gripper 22 to the magnitude before the decrease in the magnitude in S94 (see fig. 16) (S85). The CPU91 sets the value of the estimated disconnection count U to 0(S86), and returns the processing to the first sewing processing (see fig. 13). When the CPU91 determines that the value of the estimated disconnection count U is 0 (S81: no), the CPU91 returns the process to the first sewing process.

During sewing, the CPU91 repeatedly executes the first thread breakage prediction processing to determine whether or not the occurrence of thread breakage is predicted. When the occurrence of thread breakage is continuously predicted after the thread breakage avoiding process (S73) is executed, and the CPU91 determines that the value of the thread breakage prediction count U reaches the thread breakage prediction stop count X (S72: no), the CPU91 sets the thread breakage prediction stop flag to 1(S74), and returns the process to the first sewing process.

Referring to fig. 17, the first skip stitch prediction processing will be described. The first skip pin prediction processing is processing for predicting occurrence of skip pins. The CPU91 determines whether the first tension is on the decreasing trend based on the five first tensions acquired through S34 (refer to fig. 13) (S111). When the CPU91 determines that the first tension is not in the decreasing tendency (S111: no), the CPU91 shifts the process to S113. When the CPU91 determines that the first tension is in the decreasing trend (S111: yes), the CPU91 determines whether the second tension is in the increasing trend based on the five second tensions acquired through S34 (S112). When the CPU91 determines that the second tension is not in the increasing trend (S112: no), the CPU91 shifts the process to S113. When the CPU91 determines that the second tension is in the increasing trend (S112: yes), the CPU91 shifts the process to S121. The CPU91 determines whether the third movement amount is on the decreasing trend based on the five third movement amounts acquired through S34 (S113). When the CPU91 determines that the third movement amount does not exhibit the decreasing tendency (S113: no), the CPU91 shifts the process to S131. When the CPU91 determines that the third movement amount is on the decreasing trend (S113: yes), the CPU91 shifts the process to S121.

When the CPU91 determines that the first tension is in the decreasing trend and the second tension is in the increasing trend (S112: yes), or when the CPU91 determines that the third movement amount is in the decreasing trend (S113: yes), the CPU91 predicts the occurrence of a stitch skip and adds 1 to the value of the stitch skip prediction count V (S121). The CPU91 determines whether the value of the skip stitch prediction count V is smaller than the skip stitch prediction stop number Y (S122). When the CPU91 determines that the value of the stitch skipping prediction count V is smaller than the stitch skipping prediction stop count Y (yes in S122), the CPU91 executes a stitch skipping avoidance process (S123) and returns the process to the first sewing process (see fig. 13).

Referring to fig. 18, the skip stitch avoiding process is explained. The skip stitch avoiding process is a process of avoiding the occurrence of a skip stitch when the occurrence of a skip stitch is predicted. The CPU91 determines whether or not the value of the skip stitch prediction count V is 1 (S141). When the CPU91 determines that the value of the skip stitch prediction count V is 1 (S141: yes), the CPU91 outputs a sound from the speaker 39 and executes a skip stitch avoidance notification notifying that the execution of the avoidance control is notified (S142). The CPU91 reduces the rotation speed of the main motor 27 (S143), controls the thread tension motor 16 to reduce the thread tension applied by the main thread gripper 22 (S144), and shifts the process to S151. S143 and S144 are the same as S93 (see fig. 16) and S94 (see fig. 16). When the occurrence of a stitch is continuously predicted and the CPU91 determines that the value of the stitch prediction count V is greater than 1 (S141: no), the CPU91 regards the execution of avoidance control and shifts the process to S151.

The CPU91 determines whether or not the value of the skip stitch prediction count V is equal to or greater than half the skip stitch prediction stop number Y (S151). When the occurrence of a skip stitch is continuously predicted, the CPU91 notifies the prediction of the occurrence of a skip stitch in a plurality of levels according to the number of times the prediction is continued (the value of the skip stitch prediction count V). When the CPU91 determines that the value of the skip-stitch prediction count V is less than half the skip-stitch prediction stop number Y (no in S151), the CPU91 executes a first skip-stitch prediction notification (S152) and returns the process to the first skip-stitch prediction process (see fig. 17). When the first skip stitch prediction is notified, the CPU91 causes the skip stitch LED72 to emit yellow light. When the CPU91 determines that the value of the skip-stitch prediction count V is equal to or greater than half the skip-stitch prediction stop number Y (yes in S151), the CPU91 executes a second skip-stitch prediction notification (S153), and returns the process to the first skip-stitch prediction process. When the second skip stitch prediction is notified, the CPU91 makes the skip stitch LED72 emit orange light.

As shown in fig. 17, when the CPU91 determines that the first tension is not decreasing (S111: no) or the second tension is not increasing (S112: no), and the third movement amount is not decreasing (S113: no), the CPU91 determines that the occurrence of a stitch skip is not predicted, and the process proceeds to S131. The CPU91 determines whether or not the value of the skip stitch prediction count V is 1 or more (S131). When the CPU91 determines that the value of the skip-stitch prediction count V is 1 or more (S131: yes), the CPU91 ends the first skip-stitch prediction notification (see S152 and fig. 18) and the second skip-stitch prediction notification (see S153 and fig. 18), and turns off the skip-stitch LED72 (S132). The CPU91 ends the skip prevention notification (see S142 and fig. 18), and stops the sound output from the speaker 39 (S133). The CPU91 increases the rotation speed of the main motor 27 to the rotation speed before being decelerated at S143 (see fig. 18) (S134). S134 is the same process as S84 (see fig. 15). The CPU91 controls the thread tension motor 16 to increase the magnitude of the needle thread tension applied by the main thread gripper 22 to the magnitude before the decrease in the step S144 (see fig. 18) (S135). S135 is the same process as S85 (see fig. 15). The CPU91 sets the skip stitch prediction count V to 0(S136), and returns the processing to the first sewing processing (see fig. 13). When the CPU91 determines that the skip stitch prediction count V has a value of 0 (S131: no), the CPU91 returns the process to the first sewing process.

During sewing, the CPU91 repeatedly executes the first skip stitch prediction processing to determine whether or not the skip stitch is predicted. After the skip stitch avoiding process (S123) is executed, if the occurrence of a skip stitch is continuously predicted and the CPU91 determines that the value of the skip stitch prediction count V has reached the skip stitch prediction stop number Y (S122: no), the CPU91 sets the skip stitch prediction stop flag to 1(S124) and returns the process to the first sewing process.

Referring to fig. 19, the first wire rewinding failure prediction process will be described. The first wire rewinding failure prediction processing is processing for predicting occurrence of wire rewinding failure. The CPU91 determines whether the first tension is on the increasing trend based on the five first tensions acquired through S34 (refer to fig. 13) (S161). When the CPU91 determines that the first tension is not in the increasing trend (S161: no), the CPU91 shifts the process to S162. When the CPU91 determines that the first tension is in the increasing trend (S161: yes), the CPU91 shifts the process to S171. The CPU91 determines whether the first movement amount is on the increasing trend based on the five first movement amounts acquired through S34 (S162). When the CPU91 determines that the first movement amount does not show an increasing trend (S162: no), the CPU91 shifts the process to S181. When the CPU91 determines that the first movement amount is on the increasing trend (S162: yes), the CPU91 shifts the process to S171.

When the CPU91 determines that the first tension is in the increasing trend (S161: yes), or when the CPU91 determines that the first movement amount is in the increasing trend (S162: yes), the CPU91 predicts the occurrence of a wire rewinding failure and adds 1 to the value of the wire rewinding failure prediction count W (S171). The CPU91 determines whether the value of the wire rewinding failure prediction count W is smaller than the wire rewinding failure prediction stop number Z (S172). When the CPU91 determines that the value of the winding failure prediction count W is smaller than the winding failure prediction stop number Z (yes in S172), the CPU91 executes a winding failure avoidance process (S173) and returns the process to the first sewing process (see fig. 13).

Referring to fig. 20, the process of avoiding poor wire take-up is described. The bad wire take-up avoiding process is a process for avoiding bad wire take-up when the bad wire take-up is predicted. The CPU91 determines whether the value of the wire-rewinding failure prediction count W is 1 (S191). When the CPU91 determines that the value of the wire rewinding failure prediction count W is 1 (S191: yes), the CPU91 outputs a sound from the speaker 39 and executes a wire rewinding failure avoidance notification notifying that the execution of the avoidance control is notified (S192). The CPU91 reduces the rotation speed of the main motor 27 (S193), controls the thread tension motor 16 to reduce the thread tension applied by the main thread gripper 22 (S194), and shifts the process to S201. S193 and S194 are the same processing as S93 (see fig. 16) and S94 (see fig. 16). When the occurrence of the wire rewinding failure is continuously predicted and the CPU91 determines that the value of the wire rewinding failure prediction count W is greater than 1 (S191: no), the CPU91 regards that the avoidance control is being executed, and the process proceeds to S201.

The CPU91 determines whether the value of the wire rewinding failure prediction count W is equal to or greater than half the wire rewinding failure prediction stop number Z (S201). When the occurrence of the wire rewinding failure is continuously predicted, the CPU91 notifies the prediction of the occurrence of the wire rewinding failure in a plurality of levels according to the number of times of the continuous prediction. When the CPU91 determines that the value of the wire-rewinding failure prediction count W is less than half the wire-rewinding failure prediction stop count Z (no in S201), the CPU91 executes a first wire-rewinding failure prediction notification (S202), and returns the process to the first wire-rewinding failure prediction process (see fig. 19). When the first poor wire take-up prediction is notified, the CPU91 makes the poor wire take-up LED73 emit yellow light. When the CPU91 determines that the value of the wire-rewinding failure prediction count W is equal to or greater than half the wire-rewinding failure prediction stop count Z (yes in S201), the CPU91 executes a second wire-rewinding failure prediction notification (S203), and returns the process to the first wire-rewinding failure prediction process. When the second wire rewinding failure prediction is notified, the CPU91 makes the wire rewinding failure LED73 emit orange light.

As shown in fig. 19, when the CPU91 determines that the first tension is not in the increasing trend (S161: no) and the first movement amount is not in the increasing trend (S162: no), the CPU91 determines that the occurrence of a wire rewinding failure is not predicted, and shifts the process to S181. The CPU91 determines whether or not the value of the wire-rewinding failure prediction count W is 1 or more (S181). When the CPU91 determines that the value of the wire rewinding failure prediction count W is 1 or more (S181: yes), the CPU91 ends the first wire rewinding failure prediction notification (see S202 and fig. 20) and the second wire rewinding failure prediction notification (see S203 and fig. 20), and turns off the wire rewinding failure LED73 (S182). The CPU91 ends the notification of the wire rewinding failure avoidance (see S192 and fig. 20), and stops the sound output from the speaker 39 (S183). The CPU91 increases the rotation speed of the main motor 27 to the rotation speed before being decelerated at S193 (see fig. 20) (S184). S184 is the same process as S84 (see fig. 15). The CPU91 controls the thread tension motor 16 to increase the magnitude of the needle thread tension applied by the main thread gripper 22 to the magnitude before the decrease in the step S194 (see fig. 20) (S185). S185 is the same process as S85 (see fig. 15). The CPU91 sets the value of the estimated take-up failure count W to 0(S186), and returns the processing to the first sewing processing (see fig. 13). When the CPU91 determines that the value of the estimated take-up failure count W is 0 (S181: no), the CPU91 returns the process to the first sewing process.

In the sewing process, the CPU91 repeatedly executes the first defective take-up prediction process to determine whether or not a defective take-up is predicted. After the thread take-up failure avoidance process (S173) is executed, if the occurrence of thread take-up failure is continuously predicted, and the CPU91 determines that the value of the thread take-up failure prediction count W has reached the thread take-up failure prediction stop count Z (S172: no), the CPU91 sets the thread take-up failure prediction stop flag to 1(S174), and returns the process to the first sewing process.

As shown in fig. 13, after the first wire rewinding failure prediction process is executed (S37), the CPU91 determines whether or not any one of the wire breakage prediction stop flag, the skip pin prediction stop flag, and the wire rewinding failure prediction stop flag is 1 (S38). When the CPU91 determines that the disconnection prediction stop flag, the skip prediction stop flag, and the reception failure prediction stop flag are all 0 (S38: no), the CPU91 shifts the process to S23.

The CPU91 repeatedly executes S21 to S23. When receiving the closing signal from the pedal 38, the CPU91 determines that sewing is finished (S23: yes). The CPU91 controls the solenoid 17A to execute the wire cutting (S41). The CPU91 stops driving the driving part (S42) and the sewing machine 1 ends sewing. The CPU91 shifts the process to S44.

In some cases, the occurrence of defective sewing is continuously predicted after the avoidance control is executed. In this case, any one of the disconnection prediction stop flag, the skip stitch prediction stop flag, and the winding failure prediction stop flag is set to 1 (see fig. 15, 17, and 19). When the CPU91 determines that any one of the disconnection prediction stop flag, the skip prediction stop flag, and the wire-rewinding failure prediction stop flag is 1 (yes in S38), the CPU91 executes the prediction stop processing (S43), and the process proceeds to S44.

Referring to fig. 21, the prediction stop processing is explained. The prediction stop processing is processing for stopping sewing when the occurrence of sewing failure is repeatedly predicted even after the avoidance control is executed. The CPU91 determines whether the sewing failure predicted continuously is a broken thread (S211). When the yarn breakage prediction stop flag is 1 and the CPU91 determines that the sewing failure predicted continuously is a yarn breakage (S211: yes), the CPU91 ends the first yarn breakage prediction notification and the second yarn breakage prediction notification (S212). The CPU91 ends the disconnection avoidance notification (S213). The CPU91 executes the disconnection prediction stop notification (S214). When the disconnection prediction stop notification is issued, the CPU91 causes the disconnection LED71 to emit red light and outputs a sound from the speaker 39. The CPU91 shifts the process to S241.

When the thread breakage prediction stop flag is 0 and the CPU91 determines that the sewing failure predicted continuously is not a thread breakage (S211: no), the CPU91 determines whether the sewing failure predicted continuously is a skip stitch (S221). When the skip stitch prediction stop flag is 1 and the CPU91 determines that the sewing failure predicted continuously is a skip stitch (S221: yes), the CPU91 ends the first skip stitch prediction notification and the second skip stitch prediction notification (S222). The CPU91 ends the avoid skip pin notification (S223). The CPU91 executes the skip stitch prediction stop notification (S224). When the skip stitch prediction stop notification is made, the CPU91 makes the skip stitch LED72 emit red light and outputs a sound from the speaker 39. The CPU91 shifts the process to S241.

When the predicted stop flag for thread breakage and the predicted stop flag for stitch skipping are both 0 and the CPU91 determines that the sewing failure predicted continuously is a thread take-up failure (S221: no), the CPU91 ends the first thread take-up failure prediction notification and the second thread take-up failure prediction notification (S232). The CPU91 ends the avoidance of poor take-up notification (S233). The CPU91 executes the wire-rewinding failure prediction stop notification (S234). When the wire rewinding failure prediction stop notification is made, the CPU91 makes the wire rewinding failure LED73 red-colored and outputs a sound from the speaker 39. The CPU91 shifts the process to S241.

The CPU91 stops driving the driving unit (S241) and the sewing machine 1 ends sewing. The CPU91 returns the processing to the first sewing processing (see fig. 13).

As shown in fig. 13, the CPU91 determines whether there is an operation to turn off the power of the sewing machine 1 (S44). When the CPU91 determines that there is no operation to turn off the power of the sewing machine 1 (S44: no), the CPU91 returns the process to S1 (refer to fig. 12). The operator places the unsewn cloth 69 on the needle plate 7 to replace the sewn cloth 69, operates the pedal 38 (S11: YES), and restarts sewing. When the CPU91 determines that there is an operation to turn off the power of the sewing machine 1 (S44: yes), the CPU91 ends the first sewing process.

As described above, when the first sewing process is executed, the CPU91 acquires the varying tension and the varying movement amount that periodically vary during sewing and stores them in the RAM93 (S51). The CPU91 acquires a feature amount from the varied tension and the varied movement amount stored in the RAM93 (S34). The CPU91 predicts the occurrence of sewing failure based on the change of the characteristic amount (S35-S37). Therefore, the sewing machine 1 can prevent the occurrence of sewing failure.

The CPU91 predicts the occurrence of sewing failure based on the transition of the characteristic amount in units of the sewing period of one stitch. The feature amount periodically varies in units of prediction units. Therefore, the sewing machine 1 can improve the accuracy of preventing the occurrence of the sewing failure.

The characteristic amounts are a first tension, a second tension, a first movement amount, a second movement amount, and a third movement amount based on a lifting period of the thread take-up lever, a shuttle catching period, and a changing tension and a changing movement amount when the needle 10 reaches a top dead center in a sewing period corresponding to one stitch. The first tension, the second tension, the first movement amount, the second movement amount, and the third movement amount are all quantities that represent characteristics and that change before a sewing failure occurs. Therefore, the sewing machine 1 can improve the accuracy of preventing the occurrence of the sewing failure.

The first tension, the second tension, the first movement amount, and the second movement amount, which are characteristic amounts, are magnitudes of a varying tension and a varying movement amount during a take-up lever lifting period and a shuttle catching period. The third movement amount as the characteristic amount is a magnitude of a fluctuation movement amount during the sewing period of one stitch. The first tension, the second tension, the first movement amount, the second movement amount, and the third movement amount are all quantities that represent characteristics and that change before a sewing failure occurs. Therefore, the sewing machine 1 can improve the accuracy of preventing the occurrence of the sewing failure.

When the sewing failure is predicted, the CPU91 counts the number of times of the sewing failure is predicted continuously by using the thread breakage prediction count U, the skip stitch prediction count V, and the thread take-up failure prediction count W (S71, S121, S171). The CPU91 determines that: the larger the values of the thread breakage prediction count U, the stitch skipping prediction count V, and the thread take-up failure prediction count W are, the higher the possibility of occurrence of sewing failure is. When the sewing machine 1 predicts the sewing failure, the prediction grade is identified by using the thread breakage prediction count U, the skip stitch prediction count V, and the thread take-up failure prediction count W. The sewing machine 1 can predict the possibility of the sewing failure occurrence in a plurality of levels, and therefore, can improve the accuracy of preventing the sewing failure occurrence.

The CPU91 acquires the face line tension based on the detection result of the magnetic sensor 53. The CPU91 acquires the face line movement amount based on the detection result of the encoder 16A. The CPU91 predicts the occurrence of sewing failure based on the transition of each prediction unit of the first tension, the second tension, the first shift amount, the second shift amount and the third shift amount, which are characteristic amounts of the upper thread tension and the upper thread shift amount that vary during the sewing of one stitch. The CPU91 can easily acquire the face line tension based on the detection result of the magnetic sensor 53. The CPU91 can easily acquire the upper thread moving amount based on the detection result of the encoder 16A. Therefore, the sewing machine 1 can easily prevent the occurrence of defective sewing.

The sewing failure includes a broken thread. The CPU91 predicts the occurrence of thread breakage based on the transition of each prediction unit of the first tension, the second tension, the first shift amount, and the second shift amount, which are characteristic amounts of the upper thread tension and the upper thread shift amount (S61 to S64), and thus easily compares the transitions. Therefore, the sewing machine 1 can prevent the occurrence of thread breakage.

The sewing failure comprises a skip stitch. The CPU91 predicts the occurrence of stitch skipping based on the transition of each prediction unit of the first tension, the second tension and the third shift amount, which are characteristic amounts of the upper thread tension and the upper thread shift amount (S111 to S113), and therefore, the transitions can be easily compared. Therefore, the sewing machine 1 can prevent the occurrence of stitch skipping.

Poor sewing comprises poor line taking. The CPU91 predicts the occurrence of a take-up failure based on the transition of each prediction unit of the first tension and the first shift amount, which are characteristic amounts of the upper thread tension and the upper thread shift amount (S161 and S162), and thus easily compares the transitions. Therefore, the sewing machine 1 can prevent the occurrence of poor take-up.

The CPU91 predicts the occurrence of thread breakage when both the first tension of the upper thread tension during the take-up lever raising period and the second tension of the upper thread tension during the shuttle catching period increase (YES in S61 and S62). The CPU91 predicts the occurrence of thread breakage when both the first moving amount of the upper thread moving amount in the raising period of the thread take-up lever and the second moving amount of the upper thread moving amount in the catching period of the shuttle are decreasing (S63: YES, S64: YES). When the first tension, the second tension, the first movement amount, and the second movement amount are changed from those in normal sewing, a sewing failure is likely to occur. The sewing machine 1 predicts the occurrence of thread breakage based on the transition of the first tension, the second tension, the first movement amount, and the second movement amount, and therefore can improve the accuracy of preventing the occurrence of thread breakage.

When the first tension of the upper thread tension in the period of lifting the thread take-up lever is decreasing (S111: YES), the CPU91 predicts the occurrence of stitch skipping. When the third movement amount of the upper thread movement amount during the sewing of one stitch amount is decreasing (S113: YES), the CPU91 predicts the occurrence of stitch skipping. If the first tension and the third movement amount are changed from those in normal sewing, sewing failure is likely to occur. The sewing machine 1 predicts the occurrence of stitch skipping based on the transition of the first tension and the third movement amount, and therefore, the accuracy of preventing the occurrence of stitch skipping can be improved.

The CPU91 predicts the occurrence of stitch skipping when the first tension of the upper thread tension during the take-up lever lifting period is decreasing (S111: YES) and the second tension of the upper thread tension during the shuttle catching period is increasing (S112: YES). When the first tension and the second tension are changed from the normal sewing, the sewing failure is easily caused. The sewing machine 1 predicts the occurrence of stitch skipping based on the transition of the first tension and the second tension, and therefore, can improve the accuracy of preventing the occurrence of stitch skipping.

When the first tension of the upper thread tension increases during the raising of the thread take-up lever (S161: YES), the CPU91 predicts the occurrence of a take-up failure. When the first movement amount of the upper thread movement amount during the take-up lever is increasing (S162: YES), the CPU91 predicts the occurrence of a take-up failure. If the first tension and the first movement amount are changed from those in normal sewing, defective sewing is likely to occur. The sewing machine 1 predicts the occurrence of the poor take-up according to the transition of the first tension and the first movement amount, and therefore can improve the accuracy of preventing the occurrence of the poor take-up.

When the occurrence of a sewing failure is predicted, the CPU91 controls the driving unit to execute an avoidance control for avoiding the occurrence of a sewing failure (S73, S123, S173). The CPU91 performs avoidance control to avoid the sewing failure. Therefore, the sewing machine 1 can prevent the occurrence of sewing failure.

When the occurrence of a sewing failure is predicted, the CPU91 reduces the rotation speed of the main motor 27 as avoidance control (S93, S143, S193). By reducing the rotation speed of the main motor 27, the variation per unit of the characteristic amount is reduced. Therefore, the sewing machine 1 can improve the accuracy of preventing the occurrence of the sewing failure.

When the occurrence of the sewing failure is predicted, the CPU91 reduces the magnitude of the needle thread tension applied by the main thread gripper 22 as avoidance control (S94, S144, S194). By controlling the variation of the needle thread tension applied by the main thread gripper 22, the variation per unit of the characteristic amount is reduced. Therefore, the sewing machine 1 can improve the accuracy of preventing the occurrence of the sewing failure.

After the avoidance control is executed, when the occurrence of defective sewing is continuously predicted, the CPU91 executes the prediction stop process (S43) and stops driving the driving unit (S241). Therefore, the sewing machine 1 can prevent the occurrence of the sewing failure when the occurrence of the sewing failure which cannot be avoided is predicted.

When the occurrence of a disconnection is predicted, the CPU91 executes a first disconnection prediction notification (S102) and a second disconnection prediction notification (S103) for emitting a disconnection LED 71. When the occurrence of a stitch is predicted, the CPU91 executes a first stitch prediction notification (S152) and a second stitch prediction notification (S153) for lighting the stitch LED 72. When the occurrence of a wire rewinding failure is predicted, the CPU91 executes a first wire rewinding failure prediction notification (S202) and a second wire rewinding failure prediction notification (S203) for emitting a wire rewinding failure LED 73. Therefore, with the sewing machine 1, the operator can grasp the prediction of the occurrence of the sewing failure.

When the occurrence of a disconnection is continuously predicted, the CPU91 executes either the first disconnection prediction notification (S102) or the second disconnection prediction notification (S103) in accordance with the value of the disconnection prediction count U. When the occurrence of a skip stitch is continuously predicted, the CPU91 executes either the first skip stitch prediction notification (S152) or the second skip stitch prediction notification (S153) in accordance with the value of the skip stitch prediction count V. When the occurrence of the wire rewinding failure is continuously predicted, the CPU91 executes any one of the first wire rewinding failure prediction notification (S202) and the second wire rewinding failure prediction notification (S203) in accordance with the value of the wire rewinding failure prediction count W. When the sewing failure is predicted, the sewing machine 1 identifies the prediction grade by using the thread breakage prediction count U, the skip stitch prediction count V, and the thread take-up failure prediction count W. The CPU91 informs the prediction of the sewing failure occurrence in a plurality of levels according to the values of the thread breakage prediction count U, the stitch skipping prediction count V, and the thread take-up failure prediction count W. Therefore, with the sewing machine 1, the operator can grasp the degree of possibility of the occurrence of the sewing failure.

When the disconnection avoiding process is executed, the CPU91 executes a disconnection avoiding notification that a sound is output from the speaker 39 (S92). When the skip stitch avoidance process is executed, the CPU91 executes a skip stitch avoidance notification that outputs a sound from the speaker 39 (S142). When the wire rewinding failure avoidance process is executed, the CPU91 executes a wire rewinding failure avoidance notification that outputs a sound from the speaker 39 (S192). With the sewing machine 1, the operator can grasp the situation where the occurrence of the sewing failure is avoided when the occurrence of the sewing failure is predicted.

When the drive unit is stopped in response to the occurrence of a disconnection, the CPU91 executes a disconnection prediction stop notification that causes the disconnection LED71 to emit light and outputs a sound from the speaker 39 (S214). When the occurrence of the stitch is continuously predicted and the driving of the driving section is stopped, the CPU91 executes a stitch prediction stop notification that causes the stitch LED72 to emit light and outputs a sound from the speaker 39 (S224). When the occurrence of the wire rewinding failure is continuously predicted and the driving of the driving unit is stopped, the CPU91 executes a wire rewinding failure prediction stop notification that causes the wire rewinding failure LED73 to emit light and outputs a sound from the speaker 39 (S234). Therefore, with the sewing machine 1, the operator can grasp that sewing is stopped due to the occurrence of unavoidable defective sewing.

The second sewing process of the sewing machine 1 will be described with reference to fig. 12, 22 to 24. The operator inputs the execution instruction of the second sewing process by switching on the power supply of the sewing machine 1 and operating the input unit 24. When the CPU91 detects an input of an instruction to execute the second sewing process, it reads the program from the ROM92 and starts the second sewing process.

In the second sewing process, when the value of the accumulated needle fall count L is a multiple of the predetermined predicted execution count M, the CPU91 predicts whether a sewing failure has occurred. That is, the prediction unit in the second sewing process is the predicted execution count M. The CPU91 obtains a first tension, a second tension, a first movement amount, a second movement amount, and a third movement amount during sewing for one stitch. The CPU91 calculates an average value in the prediction units of the first tension, the second tension, the first movement amount, the second movement amount, and the third movement amount, and stores the average value in the RAM 93. The average values in the prediction units of the first tension, the second tension, the first movement amount, the second movement amount, and the third movement amount are referred to as an average first tension, an average second tension, an average first movement amount, an average second movement amount, and an average third movement amount, respectively.

The average first tension, the average second tension, the average first movement amount, the average second movement amount, and the average third movement amount are characteristic amounts of the second sewing process. In the second sewing process, the CPU91 predicts the occurrence of thread breakage when the average first tension and the average second tension tend to increase or when the average first moving amount and the average second moving amount tend to decrease. The CPU91 predicts the occurrence of a stitch jump when the average first tension is on a decreasing trend and the average second tension is on an increasing trend, or when the average third movement amount is on a decreasing trend. The CPU91 predicts the occurrence of a wire rewinding failure when the average first tension is on an increasing trend or when the average first movement amount is on an increasing trend.

The flag used by the CPU91 in the second sewing process is the same as that in the first sewing process. The CPU91 uses the same count in the second sewing process as in the first sewing process, except that the predicted broken thread count U is not used in the second sewing process.

The second sewing process performs the processes of S321, S22, S31, S332 to S337 instead of the processes of S21, S22, S31 to S37 in the first sewing process, and is different from the first sewing process only in this respect. In the following, the same processing as the first sewing processing is denoted by the same reference numerals, and the description thereof is omitted, and processing different from the first sewing processing is described.

As shown in fig. 22, after the sewing is started by S11, S13 (refer to fig. 12), the CPU91 performs the second feature amount processing (S321). The second feature amount processing is processing for acquiring a feature amount of the second sewing processing.

Referring to fig. 23, the second feature amount processing is explained. The CPU91 acquires the varying tension and the varying movement amount and stores them in the RAM93 (S51). The CPU91 determines whether the upper shaft angle is within the take-up lever lifting period (S52). When the CPU91 determines that the upper shaft angle is not within the thread take-up lever lifting period (S52: no), the CPU91 shifts the process to S55. When the CPU91 determines that the upper shaft angle is within the take-up lever lifting period (S52: yes), the CPU91 acquires the first tension based on the detection result of the magnetic sensor 53, calculates the average first tension, and stores the average first tension in the RAM93 (S353). The CPU91 acquires the first movement amount based on the detection result of the encoder 16A, calculates an average first movement amount, and stores it in the RAM93 (S354). The CPU91 shifts the process to S55.

The CPU91 determines whether the upper axis angle is within the shuttle capturing period (S55). When the CPU91 determines that the upper axis angle is not within the shuttle capturing period (S55: no), the CPU91 shifts the process to S58. When the CPU91 determines that the upper axis angle is within the shuttle capturing period (S55: yes), the CPU91 acquires the second tension based on the detection result of the magnetic sensor 53, calculates the average second tension, and stores the average second tension in the RAM93 (S356). The CPU91 acquires the second movement amount based on the detection result of the encoder 16A, calculates an average second movement amount, and stores it in the RAM93 (S357). The CPU91 shifts the process to S58.

The CPU91 determines whether the needle 10 is at the top dead center (S58). When the upper shaft angle is not 360 degrees and the CPU91 determines that the needle 10 is not at the top dead center (S58: no), the CPU91 returns the process to the second sewing process (see fig. 22). When the CPU91 determines that the needle 10 is at the top dead center with the upper shaft angle of 360 degrees (S58: yes), the CPU91 obtains the third movement amount based on the detection result of the encoder 16A, calculates the average third movement amount, and stores it in the RAM93 (S359). The CPU91 sets the size of the upper thread moving amount to 0(S60) and returns the process to the second sewing process.

As shown in fig. 22, after the second feature amount processing is executed (S321), the CPU91 determines whether the needle 10 is at the top dead center (S22). When the CPU91 determines that the needle 10 is not at the top dead center (S22: no), the CPU91 determines whether sewing is finished based on the detection result of the pedal 38 (S23). When receiving the on signal from the pedal 38, the CPU91 determines not to end sewing (S23: no), and returns the process to S321.

The CPU91 repeatedly executes S321, S22, S23. When the CPU91 determines that the hand 10 is at the top dead center (yes in S22), the CPU91 adds 1 to the values of the needle count N and the cumulative needle count L (S31). The CPU91 determines whether or not the value of the accumulated needle fall count L is a multiple of the predicted execution count M (S332). When the CPU91 determines that the value of the accumulated needle fall count L is not a multiple of the predicted execution count M (S332: no), the CPU91 shifts the process to S23.

When the CPU91 determines that the value of the accumulated needle fall count L is a multiple of the predicted execution count M (YES in S332), the CPU91 determines whether the value of the accumulated needle fall count L is 5 times or more the predicted execution count M (S333). When the CPU91 judges that the value of the accumulated needle count L is less than 5 times the predicted execution count M (NO in S333), the CPU91 judges that the sewing failure is not predicted, and the process proceeds to S23. When the CPU91 determines that the value of the accumulated needle count L is equal to or greater than 5 times the predicted execution count M (S333: yes), the CPU91 acquires five feature amounts newly stored among the respective feature amounts stored in the RAM93 (S34). The CPU91 executes the second disconnection predicting process (S335).

Referring to fig. 24, the second disconnection prediction processing will be described. The second disconnection prediction processing is processing for predicting the occurrence of disconnection. The CPU91 determines whether the average first tension is on the increasing trend based on the five average first tensions acquired through S34 (refer to fig. 22) (S361). When the CPU91 determines that the average first tension is not in the increasing trend (S361: no), the CPU91 shifts the process to S363. When the CPU91 determines that the average first tension is in an increasing trend (S361: yes), the CPU91 determines whether the average second tension is in an increasing trend based on the five average second tensions acquired through S34 (S362). When the CPU91 determines that the average second tension is not in the increasing trend (S362: no), the CPU91 shifts the process to S363. When the CPU91 determines that the average second tension is in the increasing trend (S362: yes), the CPU91 shifts the process to S374.

The CPU91 determines whether the average first movement amount is on the decreasing trend based on the five average first movement amounts acquired through S34 (S363). When the CPU91 determines that the average first movement amount does not tend to decrease (S363: no), the CPU91 returns the process to the second sewing process (see fig. 22). When the CPU91 determines that the average first movement amount is in the decreasing trend (S363: yes), the CPU91 determines whether the average second movement amount is in the decreasing trend based on the five average second movement amounts acquired through S34 (S364). When the CPU91 determines that the average second movement amount does not tend to decrease (S364: no), the CPU91 returns the process to the second sewing process. When the CPU91 determines that the average second movement amount is in the decreasing trend (S364: yes), the CPU91 shifts the process to S374.

When the CPU91 determines that the average first tension and the average second tension are in the increasing trend (yes in S362), or when the CPU91 determines that the average first movement amount and the average second movement amount are in the decreasing trend (yes in S364), the CPU91 regards the occurrence of a thread breakage as predicted, sets the thread breakage prediction stop flag to 1(S374), and returns the process to the second sewing process. When the occurrence of a thread breakage is predicted in the second sewing process, the CPU91 immediately executes the prediction stop process without executing the avoidance control for avoiding the occurrence of a thread breakage (see S43 and fig. 22).

As shown in fig. 22, after executing the second disconnection prediction processing (S335), the CPU91 executes the second skip prediction processing (S336). The second skip stitch prediction processing is different from the first skip stitch prediction processing only in predicting the occurrence of a skip stitch from transitions of the average first tension, the average second tension, and the average third movement amount, and therefore, a description of the second skip stitch prediction processing is omitted. After executing the second skip stitch prediction process (S336), the CPU91 executes a second wire rewinding failure prediction process (S337). The second wire rewinding failure prediction process differs from the first wire rewinding failure prediction process only in predicting the occurrence of the wire rewinding failure from the transition of the average first tension and the average first movement amount, and therefore, the description of the second wire rewinding failure prediction process is omitted.

The CPU91 determines whether or not any one of the disconnection prediction stop flag, the skip stitch prediction stop flag, and the collection failure prediction stop flag is 1 (S38). When the CPU91 determines that the disconnection prediction stop flag, the skip prediction stop flag, and the reception failure prediction stop flag are all 0 (S38: no), the CPU91 shifts the process to S23. When the CPU91 determines that any one of the disconnection prediction stop flag, the skip prediction stop flag, and the wire-rewinding failure prediction stop flag is 1 (yes in S38), the CPU91 executes the prediction stop processing (S43), and the process proceeds to S44.

As described above, when the second sewing process is executed, the CPU91 sets the thread breakage prediction stop flag to 1(S374), stops driving the driving unit (S43), and stops sewing when thread breakage is predicted. Therefore, the sewing machine 1 can prevent the occurrence of thread breakage.

In the above embodiment, the sewing machine 1 is an example of the sewing machine and the failure prediction device of the present invention. The CPU91 executing S51 exemplifies the acquisition unit of the present invention. The RAM93 is an example of the storage unit of the present invention. The CPU91 executing S35 to S37 and S335 to S337 is an example of the prediction unit of the present invention. The prediction unit is an example of the unit of the present invention. The variable tension and the variable movement amount are examples of the variables of the present invention. The take-up lever lifting period and the shuttle catching period are examples of predetermined timings. The disconnection prediction count U, the skip stitch prediction count V, and the winding failure prediction count W are examples of the prediction level of the present invention. The CPU91 at the time of acquiring the tension of the upper thread based on the detection result of the magnetic sensor 53 at S51 is an example of the tension acquiring unit of the present invention. The CPU91 in the case of acquiring the needle thread movement amount based on the detection result of the magnetic sensor 53 in S51 is an example of the movement amount acquiring unit of the present invention. The CPU91 executing S73, S123, and S173 is an example of the avoidance controller of the present invention. The main motor 27 is an example of the needle bar driving unit of the present invention. The main gripper 22 is an example of the thread tension mechanism of the present invention. The CPU91 when S43 is executed exemplifies the predictive stop unit of the present invention. The CPU91 when S43 is executed in the second sewing process is an example of the breakage prediction stopping unit of the present invention. The CPU91 executing S102, S103, S152, S153, S202, and S203 is an example of the notification unit of the present invention. The CPU91 executing S102, S103, S152, S153, S202, and S203 is an example of the prediction level notification unit of the present invention. The CPU91 executing S92, S142, and S192 is an example of the avoidance notification unit of the present invention. The CPU91 when executing S214, S224, and S234 is an example of the stop notification unit of the present invention.

The present invention can be modified in various ways in addition to the above-described embodiments. The sewing machine 1 is not limited to the sewing machine for a flat seam having the shuttle 49, and may be a sewing machine for a circular seam. The CPU91 for predicting the occurrence of a sewing failure may be provided in a device different from the sewing machine 1, and the device may be used to predict the occurrence of a sewing failure in the sewing machine 1. In this case, a device having the CPU91 for predicting the occurrence of sewing failure is an example of the failure prediction device of the present invention.

The structure and the number of the devices of the sewing machine 1 may be changed as appropriate. The main thread tension 22 may be replaced with a thread tension mechanism that applies tension to the upper thread 66 by an electromagnetic element, for example. In the case where the thread tension mechanism is provided and the occurrence of a sewing failure is predicted from the transition of the varying movement amount, it is preferable that a sensor for detecting the movement amount of the upper thread is further provided.

The feature amount may be other than those of the above embodiments. For example, the size of the diameter of the face line 66 increased by the untwisting may be used as the characteristic amount. In this case, an optical sensor may be provided to detect the diameter of the upper thread 66. In the second sewing process, the number of times the first tension or the like in the prediction unit exceeds a predetermined threshold value may be used as the feature amount. The CPU91 predicts the occurrence of sewing failure when the number of times of exceeding the predetermined threshold value increases. In this case, the predetermined threshold value is an example of the variable threshold value of the present invention.

The sewing machine 1 may appropriately change the number of the feature quantities obtained in the prediction of the occurrence of the sewing failure, the feature quantities being shifted in units of prediction units. Alternatively, the sewing machine 1 may predict the occurrence of a sewing failure by acquiring different numbers of characteristic quantities for a thread breakage, a stitch skipping, and a thread take-up failure. The sewing machine 1 may predict the occurrence of the sewing failure when the needle 10 is at a position other than the top dead center.

The value of the predicted number of executions M in the second sewing process may be changed as appropriate. The values of the predicted execution number M may be different in disconnection, skip stitch, and poor wire winding. In the second sewing process, the CPU91 may predict the occurrence of a sewing failure when the value of the needle fall number N is a multiple of the predicted execution number M. In this case, if the number of stitches in one sewing is known, it is preferable that the predicted execution number M is smaller than the number of stitches in one sewing.

The sewing machine 1 may predict the occurrence of a sewing failure other than a thread breakage, a stitch skipping, and a thread take-up failure. The sewing machine 1 may predict the occurrence of one sewing failure or may not predict the occurrence of another sewing failure. The sewing machine 1 may be set individually to predict the occurrence of thread breakage, stitch skipping, defective thread take-up, and other defective sewing.

The sewing machine 1 may not notify the prediction of the sewing failure occurrence when the sewing failure occurrence is predicted. In this case, the CPU91 may omit a part or all of S102, S103, S152, S153, S202, and S203.

The sewing machine 1 may determine the level of the possibility of the sewing failure based on the cumulative number of sewing failures predicted in one sewing process. When the sewing failure is predicted, the sewing machine 1 may notify the prediction of the sewing failure in a plurality of levels without depending on the values of the thread breakage prediction count U, the skip stitch prediction count V, and the thread take-up failure prediction count W. The sewing machine 1 may be configured to notify the prediction of the sewing failure in three or more levels when the sewing failure is predicted.

The sewing machine 1 may not execute the skip stitch avoiding process (S123) when the skip stitch is predicted to occur. The sewing machine 1 may not execute the process of avoiding the defective thread take-up (S173) when the occurrence of the defective thread take-up is predicted. The sewing machine 1 can avoid the occurrence of poor sewing without informing the avoidance of the poor sewing. In this case, the CPU91 may omit a part or all of S92, S142, and S192.

The sewing machine 1 may execute the respective avoidance controls in the process of avoiding the thread breakage (S73), the process of avoiding the stitch skipping (S123), and the process of avoiding the poor thread take-up (S173). In the avoidance control, the rotation speed of the main motor 27 may be increased, or the needle thread tension applied by the main thread gripper 22 may be increased. In the avoidance control, the CPU91 may control the thread tension motor 16 of the main thread tension 22 to adjust the amount of thread tension. The sewing machine 1 may execute the avoidance control different depending on the values of the thread breakage prediction count U, the stitch skipping prediction count V, and the thread take-up failure prediction count W.

The sewing machine 1 may not stop driving the driving section when the occurrence of defective sewing is predicted after the avoidance control is executed. The sewing machine 1 may stop driving the driving unit based on an accumulated number of occurrences of defective sewing predicted during one sewing operation. The drive unit may be stopped when sewing failure occurs, and the drive unit may not be notified. In this case, the CPU91 may omit a part or all of S214, S224, and S234.

A program including instructions for causing the CPU91 to execute the processing in fig. 12 to 24 may be stored in the storage device of the sewing machine 1 before the CPU91 executes the program. Therefore, the program acquisition method, the acquisition path, and the device storing the program can be appropriately changed. The program executed by the CPU91 may be received from another device via cable or wireless communication and stored in a storage device such as a nonvolatile memory. Other devices include, for example, a computer, a server connected to the sewing machine 1 via a network.

The steps of the processing in fig. 12 to 24 are not limited to the example executed by the CPU91, and a part or all of the steps may be executed by another electronic device (e.g., an ASIC). Each step of the processing in fig. 12 to 24 may be distributed by a plurality of electronic devices (for example, a plurality of CPUs). The steps of the processing in fig. 12 to 24 may be changed in order, omitted, or added as appropriate. A part or all of the processing in fig. 12 to 24 may be performed by an operating system or the like running on the sewing machine 1 in accordance with instructions from the CPU 91. The various numerical values recited in the embodiments are merely examples and can be appropriately changed.