阅读说明：本技术 一种用于电动工具的电机占空比控制方法 (Motor duty ratio control method for electric tool ) 是由 杨伟明 韩挺 于 2020-12-08 设计创作，主要内容包括：本发明公开了一种用于电动工具的电机占空比控制方法,属于电机驱动技术领域,电动工具设有可前后移动的执行件及用于供电的电池包,先检测获得电动工具处于不同预定档位D-M下电机处在不同预定电压U-N时执行件前移相同距离的占空比预定值P-(M·N)；开机后电动工具的控制模块根据测得的实际档位D-A和实际电压U-B结合步骤S100中测得的占空比预定值P-(M·N)确定占空比实际值P-(A·B)。电动工具实际工作过程中,控制模块根据测得的实际档位和实际电压结合占空比预定值确定占空比实际值,如此可以在电池包输出电压降低的情况下对电机进行动态用电补偿,使电机能驱动电动工具的执行件稳定的移动,有效提高执行件在工作时的稳定性。(The invention discloses a motor duty ratio control method for an electric tool, which belongs to the technical field of motor driving M The lower motor is at different predetermined voltages U N The time executive component moves forward by the same distance and the duty ratio preset value P M·N (ii) a The control module of the electric tool after starting up is based on the measured actual gear D A And the actual voltage U B In conjunction with the predetermined value P of the duty cycle measured in step S100 M·N Determining the actual value of the duty cycle P A·B . In the actual working process of the electric tool, the control module determines the actual value of the duty ratio according to the measured actual gear and the actual voltage in combination with the predetermined value of the duty ratio, so that the dynamic electricity compensation can be performed on the motor under the condition that the output voltage of the battery pack is reduced, and the motor can drive the executing part of the electric tool to stably moveAnd the stability of the executing piece in work is effectively improved.)

1. A motor duty ratio control method for an electric tool, the electric tool is provided with an executing piece capable of moving back and forth and a battery pack for supplying power, and is characterized by comprising the following steps,

s100, detecting and obtaining that the electric tool is in different preset gears D_MThe lower motor is at different predetermined voltages U_NThe time executive component moves forward by the same distance and the duty ratio preset value P_M·N；

S200, the control module of the electric tool after starting up is used for measuring the actual gear D_AAnd the actual voltage U_BIn conjunction with the predetermined value P of the duty cycle measured in step S100_M·NDetermining the actual value of the duty cycle P_A·B。

2. The method as claimed in claim 1, wherein in step S200, if the actual gear position D is reached_AAnd a predetermined gear D_MConsistent and actual voltage U_BAnd a predetermined voltage U_NIf they are consistent, the actual value P of duty ratio is_A·BThe duty ratio preset value P under the same gear and voltage state_M·NAnd (5) the consistency is achieved.

3. The method as claimed in claim 1, wherein in step S200, if the actual gear position D is reached_AAnd a predetermined gear D_MConsistent and actual voltage U_BBetween two close predetermined voltages U_n1、U_n2(U_n1＜U_n2) Then the actual value P of the duty ratio is determined according to the formula I_A·BPredetermined gear D_MLower predetermined voltage is U_n1Duty ratio of time is predetermined value P_M·n1Predetermined gear D_MLower predetermined voltage is U_n2Duty ratio of time is predetermined value P_M·n2，

P_A·B＝(U_B-U_n1)÷(U_n2-U_n1)×(P_M·n2-P_M·n1)+P_M·n1And a formula I.

4. According to claim1, the method for controlling duty ratio of motor is characterized in that, in the step S200, if the actual gear position D is_ABetween two adjacent predetermined gears D_m1、D_m2(D_m1＜D_m2) Between and actual voltage U_BAnd a predetermined voltage U_NIf the actual value of the duty ratio is consistent with the actual value of the duty ratio, the actual value P is determined according to a formula II_A·BPredetermined shift position is D_m1When the predetermined voltage is U_NDuty ratio of time is predetermined value P_m1·NPredetermined shift position is D_m2When the predetermined voltage is U_NDuty ratio of time is predetermined value P_m2·N，

P_A·B＝(D_A-D_m1)÷(D_m2-D_m1)×(P_m2·N–P_m1·N)+P_m1·NAnd a formula II.

5. The method as claimed in claim 1, wherein in step S200, if the actual gear position D is reached_ABetween two adjacent predetermined gears D_m1、D_m2(D_m1＜D_m2) Between and actual voltage U_BBetween two close predetermined voltages U_n1、U_n2(U_n1＜U_n2) In between, the actual value P of the duty ratio is determined according to the formula III_A·BPredetermined shift position is D_m1When the predetermined voltage is U_n1Duty ratio of time is predetermined value P_m1·n1Predetermined shift position is D_m2When the predetermined voltage is U_n2Duty ratio of time is predetermined value P_m2·n2，

P_A·B＝(D_A-D_m1)÷(D_m2-D_m1)×(P_m2·n2–P_m1·n1)+P_m1·n1And a formula III.

6. The motor duty cycle control method according to claim 1, wherein in step S100, the same predetermined gear D is used_MNext two adjacent predetermined voltages U_NThe difference between the two is delta U, and delta U is more than or equal to 0.1V and less than or equal to 0.8V.

7. The motor duty cycle control method of claim 1, wherein the power tool comprises a driving wheel and a sensing element, the driving wheel is connected to a motor shaft of the motor in a driving manner and is used for driving the actuating element to move back and forth, and the sensing element detects a rotation angle of the driving wheel to enable the control module to know a distance of the actuating element moving back and forth.

8. The motor duty cycle control method of claim 7, wherein the power tool further comprises an output wheel rotating synchronously with the transmission wheel, the output wheel is provided with gear teeth, the actuator comprises a push rod, and the push rod is provided with convex teeth engaged with the gear teeth.

9. The method of claim 7, wherein the driving wheel has driving teeth, and the sensing member includes a transmitting end and a receiving end respectively disposed at two axial sides of the driving wheel and corresponding to the driving teeth.

10. The motor duty cycle control method of claim 7, wherein the driving wheel has a plurality of through holes uniformly spaced along a circumferential direction, and the sensing member includes a transmitting end and a receiving end disposed at both axial sides of the driving wheel and corresponding to the through holes.

Technical Field

The invention relates to the technical field of motor driving, in particular to a motor duty ratio control method for an electric tool.

Background

The duty ratio refers to the ratio of the energizing time and the energizing period of the pulse signal, the larger the duty ratio of the motor is, the higher the rotating speed of the motor is, and the faster the motor drives the actuating member of the electric tool to move. For the glue gun, the actuating piece comprises a push rod and a push block arranged at the front end of the push rod, the glue gun is powered by a battery pack, and the motor drives the push rod and the push block to move forwards to extrude an end cover of the rubber tube so that glue in the rubber tube flows out. Because the output voltage of battery package can reduce gradually when the power supply, the operating voltage and the rotational speed of motor also can descend gradually at the during operation, lead to the removal speed of executive component to slow down, to beating the gluey rifle, beat the gluey speed and can not remain stable, be unfavorable for improving and beat the gluey effect.

Disclosure of Invention

In order to solve the defects and shortcomings in the prior art, the invention provides a motor duty ratio control method for an electric tool, which can effectively improve the stability of an actuating member of the electric tool in working.

In order to achieve the technical purpose, the invention provides a motor duty ratio control method for an electric tool, wherein the electric tool is provided with an executing piece capable of moving back and forth and a battery pack for supplying power, the method comprises the following steps,

s100, detecting and obtaining that the electric tool is in different preset gears D_MThe lower motor is at different predetermined voltages U_NThe time executive component moves forward by the same distance and the duty ratio preset value P_M·N；

S200, the control module of the electric tool after starting up is used for measuring the actual gear D_AAnd the actual voltage U_BIn conjunction with the predetermined value P of the duty cycle measured in step S100_M·NDetermining the actual value of the duty cycle P_A·B。

Preferably, in step S200, if the actual gear position D is reached_AAnd a predetermined gear D_MConsistent and actual voltage U_BAnd a predetermined voltage U_NIf they are consistent, the actual value P of duty ratio is_A·BThe duty ratio preset value P under the same gear and voltage state_M·NAnd (5) the consistency is achieved.

Preferably, in step S200, if the actual gear position D is reached_AAnd a predetermined gear D_MConsistent and actual voltage U_BBetween two close predetermined voltages U_n1、U_n2(U_n1＜U_n2) Then the actual value P of the duty ratio is determined according to the formula I_A·BPredetermined gear D_MLower predetermined voltage is U_n1Duty ratio of time is predetermined value P_M·n1Predetermined gear D_MLower predetermined voltage is U_n2Duty ratio of time is predetermined value P_M·n2，

P_A·B＝(U_B-U_n1)÷(U_n2-U_n1)×(P_M·n2-P_M·n1)+P_M·n1And a formula I.

Preferably, in step S200, if the actual gear position D is reached_ABetween two adjacent predetermined gears D_m1、D_m2(D_m1＜D_m2) Between and actual voltage U_BAnd a predetermined voltage U_NIf the actual value of the duty ratio is consistent with the actual value of the duty ratio, the actual value P is determined according to a formula II_A·BPredetermined shift position is D_m1When the predetermined voltage is U_NDuty ratio of time is predetermined value P_m1·NPredetermined shift position is D_m2When the predetermined voltage is U_NDuty ratio of time is predetermined value P_m2·N，

P_A·B＝(D_A-D_m1)÷(D_m2-D_m1)×(P_m2·N–P_m1·N)+P_m1·NAnd a formula II.

Preferably, in step S200, if the actual gear position D is reached_ABetween two adjacent predetermined gears D_m1、D_m2(D_m1＜D_m2) Between and actual voltage U_BBetween two close predetermined voltages U_n1、U_n2(U_n1＜U_n2) In between, the actual value P of the duty ratio is determined according to the formula III_A·BPredetermined shift position is D_m1When the predetermined voltage is U_n1Duty ratio of time is predetermined value P_m1·n1Predetermined shift position is D_m2When the predetermined voltage is U_n2Duty ratio of time is predetermined value P_m2·n2，

P_A·B＝(D_A-D_m1)÷(D_m2-D_m1)×(P_m2·n2–P_m1·n1)+P_m1·n1And a formula III.

Preferably, in step S100, the same predetermined gear D is used_MNext two adjacent predetermined voltages U_NThe difference between the two is delta U, and delta U is more than or equal to 0.1V and less than or equal to 0.8V.

Preferably, the electric tool comprises a driving wheel and a sensing part, the driving wheel is connected to a motor shaft of the motor in a driving mode and used for driving the executing part to move back and forth, and the sensing part detects the rotating angle of the driving wheel to enable the control module to know the distance of the executing part moving back and forth.

Preferably, the electric tool further comprises an output wheel which rotates synchronously with the transmission wheel, the output wheel is provided with wheel teeth, the executing part comprises a push rod, and the push rod is provided with convex teeth meshed with the wheel teeth.

Preferably, the driving wheel is provided with driving teeth, and the sensing part comprises an emitting end and a receiving end which are respectively arranged on two axial sides of the driving wheel and correspond to the driving teeth.

Preferably, the driving wheel is provided with a plurality of through holes which are uniformly distributed at intervals along the circumferential direction, and the sensing part comprises an emitting end and a receiving end which are arranged on two axial sides of the driving wheel and correspond to the through holes.

After the technical scheme is adopted, the invention has the following advantages:

1. according to the motor duty ratio control method provided by the invention, duty ratio preset values of the motor under different gears and at different voltages are firstly detected, and in the actual working process of the electric tool, the control module determines the actual duty ratio value according to the measured actual gear and actual voltage in combination with the duty ratio preset value, so that dynamic power consumption compensation can be carried out on the motor under the condition that the output voltage of the battery pack is reduced, the motor can drive an executing piece of the electric tool to stably move, and the stability of the executing piece during working is effectively improved.

2. According to the measured actual gear and the actual voltage, the actual value of the duty ratio is reasonably determined through a corresponding formula, the reasonability of determining the duty ratio is improved, the power supply requirement of the motor is better met, and the working effect of the electric tool is improved.

3. The axial both sides of drive wheel and with the setting of driving tooth or through-hole correspondence on the drive wheel are located to the transmitting terminal and the receiving terminal of response piece, and the rotation angle of drive wheel is realized detecting through the number of response driving tooth or through-hole to the response piece, and then knows the distance that the push rod removed, and the structure of detecting push rod back-and-forth movement distance is rationally set up, better satisfying the detection requirement.

Drawings

FIG. 1 is a perspective view of an exemplary glue gun;

FIG. 2 is an exploded view of an embodiment glue gun;

FIG. 3 is a schematic diagram of a partial structure of a glue gun according to an embodiment;

FIG. 4 is a schematic diagram illustrating a partial structure of a second glue gun according to an embodiment.

In the figure, 100-machine shell, 200-rubber tube rack, 300-motor, 410-driving wheel, 411-driving gear, 420-output wheel, 421-gear tooth, 412-through hole, 510-push rod, 511-convex tooth, 520-push block, 600-induction part, 610-transmitting end and 620-receiving end.

Detailed Description

The invention is further described with reference to the following figures and specific examples. It is to be understood that the following terms "upper," "lower," "left," "right," "longitudinal," "lateral," "inner," "outer," "vertical," "horizontal," "top," "bottom," and the like are used merely to indicate an orientation or positional relationship relative to one another as illustrated in the drawings, merely to facilitate describing and simplifying the invention, and are not intended to indicate or imply that the device/component so referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore are not to be considered limiting of the invention.

Example one

The embodiment of the invention provides a motor duty ratio control method for an electric tool, the electric tool is provided with an executing part capable of moving back and forth and a battery pack for supplying power, the method comprises the following steps,

s100, detecting and obtaining that the electric tool is in different preset gears D_MThe lower motor is at different predetermined voltages U_NThe time executive component moves forward by the same distance and the duty ratio preset value P_M·N；

S200, after the electric tool is started, a control module of the electric tool measures an actual gear D_AAnd the actual voltage U_BIn combination with the duty ratio predetermined value measured in step S100P_M·NDetermining the actual value of the duty cycle P_A·B。

In step S100, the duty ratio preset values obtained by detection are shown in table one.

Watch 1

For improving the measuring effect, the same predetermined gear D_MNext two adjacent predetermined voltages U_NThe voltage difference between them is preferably set to a constant value DeltaU, 0.1 V.ltoreq.DeltaU.ltoreq.0.8V. The smaller Δ U, the higher the measurement accuracy. In the present embodiment, Δ U is preferably set to 0.5V, i.e., U₂Is compared with U₁Small 0.5V, U₃Is compared with U₂0.5V smaller, and so on.

In step S200, if the actual gear D is set_AAnd a predetermined gear D_MConsistent and actual voltage U_BAnd a predetermined voltage U_NIf they are consistent, the actual value P of duty ratio is_A·BThe duty ratio preset value P under the same gear and voltage state_M·NAnd (5) the consistency is achieved. For example, when the actual gear position D_AIs D₃Actual voltage U_BIs U₂Then the actual value P of the duty ratio_A·BIs namely P_3·2。

In step S200, if the actual gear D is set_AAnd a predetermined gear D_MConsistent and actual voltage U_BBetween two close predetermined voltages U_n1、U_n2(U_n1＜U_n2) Then the actual value P of the duty ratio is determined according to the formula I_A·BPredetermined gear D_MLower predetermined voltage is U_n1Duty ratio of time is predetermined value P_M·n1Predetermined gear D_MLower predetermined voltage is U_n2Duty ratio of time is predetermined value P_M·n2，

P_A·B＝(U_B-U_n1)÷(U_n2-U_n1)×(P_M·n2-P_M·n1)+P_M·n1And a formula I.

For example, if the actual gear position D_AIs D₃Actual voltage U_BBetween U and U₂And U₃In between, then the actual value of the duty ratio P_A·_BThat is (U)_B-U₂)÷(U₃-U₂)×(P_3·3–P_3·2)+P_3·2。

In step S200, if the actual gear D is set_ABetween two adjacent predetermined gears D_m1、D_m2(D_m1＜D_m2) Between and actual voltage U_BAnd a predetermined voltage U_NIf the actual value of the duty ratio is consistent with the actual value of the duty ratio, the actual value P is determined according to a formula II_A·BPredetermined shift position is D_m1When the predetermined voltage is U_NDuty ratio of time is predetermined value P_m1·NPredetermined shift position is D_m2When the predetermined voltage is U_NDuty ratio of time is predetermined value P_m2·N，

P_A·B＝(D_A-D_m1)÷(D_m2-D_m1)×(P_m2·N–P_m1·N)+P_m1·NAnd a formula II.

For example, if the actual gear position D_ABetween D₂、D₃Between and actual voltage U_BAnd a predetermined voltage U₃If they are consistent, the actual value P of duty ratio is_A·BThat is (D)_A-D₂)÷(D₃-D₂)×(P_3·3–P_2·3)+P₂·₃。

In step S200, if the actual gear D is set_ABetween two adjacent predetermined gears D_m1、D_m2(D_m1＜D_m2) Between and actual voltage U_BBetween two close predetermined voltages U_n1、U_n2(U_n1＜U_n2) In between, the actual value P of the duty ratio is determined according to the formula III_A·BPredetermined shift position is D_m1When the predetermined voltage is U_n1Duty ratio of time is predetermined value P_m1·n1Predetermined gear D_m2Is on and the predetermined voltage is U_n2Duty ratio of time is predetermined value P_m1·n1，

P_A·B＝(D_A-D_m1)÷(D_m2-D_m1)×(P_m2·n2–P_m1·n1)+P_m1·n1And a formula III. For example, if the actual gear position D_ABetween D₂、D₃Between and actual voltage U_BBetween U and U₂And U₃In between, then the actual value of the duty ratio P_A·BThat is (D)_A-D₂)÷(D₃-D₂)×(P_3·3–P_2·2)+P_2·2。

In this embodiment, an electric tool glue gun is described as an example, and the glue gun is powered by a battery pack. As shown in fig. 1 to 3, the glue gun includes a casing 100 and a hose frame 200 disposed at the front end of the casing 100, a motor 300, a driving wheel 410, an output wheel 420 and a sensing member 600 are disposed in the casing 100, the driving wheel 410 is connected to a motor shaft of the motor 300 through a speed reduction mechanism, and a plurality of driving teeth 411 are disposed on the circumference of the driving wheel 410. The output wheel 420 and the driving wheel 410 are sleeved on the same rotating shaft to realize synchronous rotation, and a plurality of wheel teeth 421 are arranged on the circumference of the output wheel 420. The actuating member comprises a push rod 510 and a push block 520 arranged at the front end of the push rod 510, a plurality of convex teeth 511 meshed with the gear teeth 421 are arranged on the push rod 510, and the push rod 520 can be erected on the machine shell 100 and the plastic pipe rack 200 in a back-and-forth movement mode. The motor 300 drives the transmission wheel 410 to rotate through a speed reducing mechanism, the transmission wheel 410 drives the output wheel 420 to synchronously rotate through a rotating shaft, and the push rod 510 is driven to move back and forth through the meshing between the convex teeth 511 and the gear teeth 421 when the output wheel 420 rotates.

In order to detect the moving distance of the push rod 510 and the push block 520, the sensor 600 includes an emitting end 610 and a receiving end 620, and the emitting end 610 and the receiving end 620 are respectively disposed at two axial sides of the driving wheel 410 and are disposed corresponding to the driving teeth 411. In this embodiment, the sensing member 600 is preferably a photoelectric switch. When the push rod 510 moves forward and backward, the driving wheel 410 rotates, and when a certain driving tooth 411 is positioned on the same straight line with the transmitting end 610 and the receiving end 620, the receiving end 620 cannot receive the signal sent by the transmitting end 610 due to the blocking effect of the driving tooth 411 when the driving wheel 410 rotates. The rotation angle of the driving wheel 410 can be obtained by counting the number of times that the receiving end 620 receives signals, and then the moving distance of the push rod 510 is obtained by calculation, so that the push rod can move forward by the same distance in each detection, and the accuracy of detection data is improved.

During the working process of the electric tool, the output voltage of the battery pack may be reduced, so that the voltage of the motor is reduced, and the control module can dynamically adjust the actual duty ratio value according to the changed voltage.

It will be appreciated that the same predetermined gear D_MTwo lower adjacent predetermined voltages U_NThe voltage difference Δ U therebetween may also be set to 0.1V, 0.2V, 0.3V, 0.4V, 0.6V, 0.7V, 0.8V.

It is understood that the power tool may be other power tools powered by a battery pack, and is not limited to the glue gun described above.

Example two

Referring to fig. 4, in this embodiment, the driving wheel 410 is provided with a plurality of through holes 412 uniformly distributed along the circumferential direction at intervals, and the transmitting end 610 and the receiving end 620 of the sensing element 600 are respectively disposed at two axial sides of the driving wheel 410 and correspond to the through holes 412. The transmission wheel 410 rotates until the transmitting end 610, the through hole 412 and the receiving end 620 are located on a straight line, and the receiving end 620 can receive the signal sent by the transmitting end 610. If the through hole 412 is not aligned with the transmitting end 610 and the receiving end 620, the receiving end 620 cannot receive the signal transmitted by the transmitting end 610 due to the blocking effect of the driving wheel 410. The rotation angle of the driving wheel 410 can be obtained by counting the number of times that the receiving end 620 receives signals, and then the moving distance of the push rod 510 is obtained by calculation, so that the push rod can move forward by the same distance in each detection, and the accuracy of detection data is improved.

The other structures of the second embodiment are the same as those of the first embodiment, and are not described in detail here.

It can be understood that the specific number of the through holes 412 can be reasonably set according to the radial size of the driving wheel 410 and the detection precision requirement, and the detection requirement can be met.

Other embodiments of the present invention than the preferred embodiments described above, and those skilled in the art can make various changes and modifications according to the present invention without departing from the spirit of the present invention, should fall within the scope of the present invention defined in the claims.