阅读说明：本技术 机床 (Machine tool ) 是由 出野真敏 伊藤慎 于 2018-12-27 设计创作，主要内容包括：本发明提供一种能减轻更换滚珠螺杆的作业的机床。机床(1)具备基台(5)、移动体(6)、滚珠螺杆(7)、帽部件(8)及支撑部(9),所述滚珠螺杆(7)具有螺母(7n)及螺杆(7s),所述帽部件(8)覆盖螺杆(7s)的端部(72),且允许螺杆(7s)以中心线(AX0)为中心旋转,所述支撑部(9)设置在基台(5)且支撑帽部件(8)。帽部件(8)具有主体部(81)及凸缘部(85),所述凸缘部(85)位于比所述主体部(81)更靠轴向(D1)的外侧(D1o),比主体部(81)更宽。支撑部(9)具有凹部(95)及定位部(91),所述凹部(95)设有开口(96)且承受主体部(81),所述开口(96)是在所述支撑部(9)设置在基台(5)的状态下,供螺杆(7s)在与轴向(D1)正交的方向(D2)上穿过,所述定位部(91)在所述凹部(9)承受主体部(81)的状态下,在轴向(D1)上,与凸缘部(85)的内侧面(86)抵接。(The invention provides a machine tool capable of reducing the work of replacing a ball screw. A machine tool (1) is provided with a base (5), a moving body (6), a ball screw (7), a cap member (8), and a support portion (9), wherein the ball screw (7) has a nut (7n) and a screw (7s), the cap member (8) covers an end (72) of the screw (7s) and allows the screw (7s) to rotate about a center line (AX0), and the support portion (9) is provided on the base (5) and supports the cap member (8). The cap member (8) has a main body (81) and a flange (85), and the flange (85) is located on the outer side (D1o) in the axial direction (D1) of the main body (81) and is wider than the main body (81). The support part (9) has a recess (95) and a positioning part (91), the recess (95) is provided with an opening (96) and receives the main body part (81), the opening (96) is used for a screw (7s) to pass through in a direction (D2) orthogonal to the axial direction (D1) under the state that the support part (9) is arranged on the base (5), and the positioning part (91) is abutted with the inner side surface (86) of the flange part (85) in the axial direction (D1) under the state that the recess (9) receives the main body part (81).)

1. A machine tool is provided with:

a base station;

a movable body configured to be movable in a specific axial direction relative to the base;

a ball screw having a nut fixed to the movable body and a screw rod that moves the nut in the axial direction by rotating about a center line oriented in the axial direction;

a cap member covering an end of the screw rod and allowing the screw rod to rotate about the center line; and

a support portion provided on the base and supporting the cap member; and is

The cap member has a main body portion and a flange portion that is located on the outer side in the axial direction than the main body portion and is wider than the main body portion;

the support portion has: a recess portion that is provided with an opening for allowing the screw to pass through in a direction orthogonal to the axial direction in a state where the support portion is provided on the base and receives the main body portion; and a positioning portion that abuts against an inner surface of the flange portion in the axial direction in a state where the main body portion is received in the recess portion.

Technical Field

The present invention relates to a machine tool that moves a movable body by a drive mechanism using a ball screw.

Background

As a machine tool for moving a main spindle base relative to a base table, an NC (numerical control) lathe having a ball screw having a screw rotationally driven by a servo motor is known. One end of the screw is attached to a torque transmission mechanism to which a rotational driving force is transmitted from the servomotor. The other end of the screw is inserted into a through hole of a support member attached to the base and is rotatably supported with respect to the support member.

For reference, patent document 1 discloses a vacuum precision positioning apparatus in which a linear motion stage device is provided in a vacuum chamber. In the linear motion stage device of the vacuum precision positioning device, an end of the screw is rotatably supported via a support unit to a mounting opening of a support frame mounted on the base. Since the opening portion of the mounting opening of the support frame faces the base, the mounting opening is closed.

Disclosure of Invention

[ problems to be solved by the invention ]

The ball screw may need to be replaced due to long-term use. Since one end of the ball screw is attached to the torque transmission mechanism connected to the servo motor, when the ball screw is removed from the lathe, the ball screw nut needs to be removed from the headstock, and the one end of the ball screw needs to be pulled out from the torque transmission mechanism. Here, since the ball screw nut needs to be attached to the screw in advance, the ball screw needs to be pulled out toward the servomotor in order to remove the ball screw from the lathe. Therefore, it is necessary to detach the support member that supports the other end of the ball screw from the base. When the ball screw is mounted on the lathe, first, the ball screw is inserted obliquely through the through hole for the ball screw nut of the spindle stock, and the other end of the ball screw is inserted into the through hole of the support member and mounted on the support member. Further, it is necessary to insert one end of the ball screw into the torque transmission mechanism, fix the support member to the base after adjusting or confirming the mounting posture of the ball screw, that is, the parallelism, and finely adjust the position of the ball screw. In particular, it is necessary for a skilled or experienced operator to perform an operation of fixing the support member while adjusting or confirming the mounting posture of the ball screw.

The above-described problems are not limited to the NC lathe, but may be present in various machine tools other than the NC lathe.

The invention discloses a machine tool capable of reducing the operation of replacing a ball screw.

[ means for solving problems ]

The machine tool of the present invention has an aspect including: a base station;

a movable body configured to be movable in a specific axial direction relative to the base;

a ball screw having a nut fixed to the movable body and a screw rod that moves the nut in the axial direction by rotating about a center line oriented in the axial direction;

a cap member covering an end of the screw rod and allowing the screw rod to rotate about the center line; and a support part provided on the base and supporting the cap member; and is

The cap member has a main body portion and a flange portion that is located on the outer side in the axial direction than the main body portion and is wider than the main body portion;

the support portion has: a recess portion that is provided with an opening for allowing the screw to pass therethrough in a direction orthogonal to the axial direction in a state where the support portion is provided on the base and receives the main body portion; and a positioning portion that abuts against an inner surface of the flange portion in the axial direction in a state where the main body portion is received in the recess portion.

[ Effect of the invention ]

According to the present invention, a machine tool that reduces the work of replacing a ball screw can be provided.

Drawings

Fig. 1 is a diagram schematically showing an example of a machine tool configuration.

Fig. 2A to 2D are diagrams schematically showing an example of replacing the ball screw.

Fig. 3 is an exploded perspective view showing an example of an end portion of the ball screw and its periphery in an exploded manner.

Fig. 4 is a vertical sectional view showing an example of an end portion of the ball screw and its periphery in section at a1 position of fig. 2.

Fig. 5 is a plan view showing an example of the end portion of the ball screw and the periphery thereof as viewed from the recess opening side of the support portion.

Fig. 6 is a side view showing another example of the cap member fixed to the support portion as viewed from the flange portion side.

Fig. 7 is a vertical sectional view showing another example of the end portion and the periphery of the ball screw in a sectional view at a1 position in fig. 2.

Detailed Description

Hereinafter, embodiments of the present invention will be described. Needless to say, the following embodiments are merely illustrative of the present invention, and not all of the features shown in the embodiments are essential to the means for solving the problem of the present invention.

(1) Summary of the technology involved in the present invention:

first, an outline of the technique included in the present invention will be described with reference to examples shown in fig. 1 to 7. The drawings of the present application are schematic illustrations of examples, and the magnification ratios in the respective directions shown in these drawings may be different, and the drawings may not be identical. Needless to say, each element of the present technology is not limited to the specific example shown by the reference numeral.

[ form 1]

A machine tool (e.g., a lathe 1) according to an aspect of the present technology includes a base 5, a moving body 6 arranged to be movable relative to the base 5 in a specific axial direction D1, a ball screw 7, a cap member 8, and a support portion 9. The ball screw 7 includes a nut 7n and a screw 7s, the nut 7n is fixed to the movable body 6, and the screw 7s moves the nut 7n in the axial direction D1 by rotating about a center line AX0 oriented in the axial direction D1. The cap member 8 covers the end 72 of the screw 7s, allowing the screw 7s to rotate about the center line AX 0. The support portion 9 is provided on the base 5 and supports the cap member 8. The cap member 8 has a body 81 and a flange 85, and the flange 85 is located on the outer side D1o in the axial direction D1 than the body 81 and is wider than the body 81. The support portion 9 has a recess 95 and a positioning portion 91, the recess 95 is provided with an opening 96 and receives the main body portion 81, the opening 96 allows the screw 7s to pass through in a direction D2 perpendicular to the axial direction D1 in a state where the support portion 9 is provided on the base 5, and the positioning portion 91 abuts against the inner surface 86 of the flange portion 85 in the axial direction D1 in a state where the recess 95 receives the main body portion 81.

In the above-described embodiment 1, the recess 95 for receiving the support portion 9 of the main body portion 81 of the cap 8 covering the end portion 72 of the screw 7s has the opening 96, and the opening 96 allows the screw 7s to pass through in the direction D2 orthogonal to the axial direction D1 in a state where the support portion 9 is provided on the base 5. Thus, when the ball screw 7 is mechanically detached, the ball screw 7 can be easily pulled out completely by tilting the screw 7s toward the opening 96 of the recess 95 without detaching the support 9 from the base 5. When the ball screw 7 is attached to the machine, the ball screw 7 can be easily disposed at a specific position after the screw 7s entering the recess 95 is inclined toward the opening 96 side without detaching the support 9 from the base 5. Further, if the cap member 8 covers the end 72 of the screw 7s, the body 81 is placed in the recess 95, and the inner surface 86 of the flange 85 abuts against the positioning portion 91 of the support 9 in the axial direction D1, the mounting posture of the ball screw 7 is determined.

As described above, since the support portion 9 does not need to be detached from the base 5 when replacing the ball screw, it is not necessary to perform a task requiring skill or experience, such as adjusting or checking the mounting posture of the ball screw 7. Therefore, this aspect can provide a machine tool that can reduce the work of replacing the ball screw.

Here, the movable body includes a table that moves together with the spindle head, a table that moves together with the tool post, and the like.

The support portion may be another member that is attachable to and detachable from the base, or may be a portion integrally formed with the base.

The opening direction of the recess in the support portion includes a direction away from the base, a direction along the base, and the like.

The above remarks are also applicable to the following embodiments.

(2) Specific examples of the machine tool structure:

fig. 1 schematically illustrates a configuration of a spindle-moving NC (numerical control) lathe 1 as an example of a machine tool. Fig. 1 is a simplified example for explaining the present technology, and does not limit the present technology. The positional relationship between the respective portions is described by way of example only. Therefore, the present technology also includes changing the left-right direction to the up-down direction or the front-back direction, changing the up-down direction to the left-right direction or the front-back direction, changing the front-back direction to the left-right direction or the up-down direction, changing the rotation direction to the reverse direction, and the like. The same direction, position, and the like are not limited to exact agreement, and include deviations from exact agreement due to errors.

The lathe 1 shown in fig. 1 includes a headstock 2 provided with a spindle head 10 holding a spindle 11 of a workpiece W0, a tool post 20 holding a tool T0 for cutting the workpiece W0, a headstock driving unit driving the headstock 10 in the X1 axis direction and the Z1 axis direction, a tool post driving unit driving the tool post 20 in the X2 axis direction and the Z2 axis direction, and an NC apparatus 3. The base 2, headstock 10, tool post 20, and major portions of the tool T0 may be formed of metal, for example. The NC apparatus 3 includes, for example, a RAM (Random access memory) for storing an NC program, a ROM (Read only memory) for storing an interpretation executor for interpreting and executing the NC program, a CPU (Central Processing Unit) for executing the interpretation executor, a timer circuit, an interface, and the like. The NC device 3 controls operations of the headstock 10, the tool rest 20, the headstock drive unit, the tool rest drive unit, and the like in accordance with an NC program.

The spindle head 10 is movable in a Z1 axis direction along the spindle center line AXs and an X1 axis direction orthogonal to the Z1 axis direction. The spindle 11 provided in the headstock 10 releasably holds a columnar (rod-shaped) workpiece W0 inserted in the Z1 axis direction by a chuck (not shown), and rotates the workpiece W0 about a spindle center line AXs along the longitudinal direction of the workpiece W0.

The tool post 20 holds 1 or more tools T0 for cutting the workpiece W0, and is movable in the X2 axis direction along the X1 axis direction and the Z2 axis direction along the Z1 axis direction. As the tool holder, a turret tool holder, a comb tool holder, or the like can be used.

The headstock drive unit shown in fig. 1 includes: an X1-axis driving element (an X1-axis motor M11, a ball screw 31b, and the like) for driving the X1-axis direction slide table 31 provided with the headstock 10 in the X1-axis direction, and a Z1-axis driving element (a Z1-axis motor M12, a ball screw 32b, and the like) for driving the Z1-axis direction slide table 32 provided with the X1-axis direction slide table 31 in the Z1-axis direction.

The X1-axis direction slide table 31 has a pair of guide members 31g slidably fitted in the X1-axis direction with a pair of guide rails 31r provided on a Z1-axis direction slide table 32 described later, and a nut 31n is detachably fixed to the X1-axis direction slide table 31. The ball screw 31b is a machine component that operates the screw 31s and the nut 31n via balls (not shown). The screw 31s rotates about a center line oriented in the X1 axis direction, and thereby moves the nut 31n in the X1 axis direction. An X1-axis motor M11 as a servo motor is provided on the Z1-axis direction slide table 32, and rotates the drive screw 31s in accordance with a command from the NC apparatus 3. The headstock 10 is moved in the X1 axis direction together with the X1 axis direction slide table 31 by the ball screw 31 b.

The Z1-axis motor M12 includes a pair of guide members 32g, the pair of guide members 32g are slidably fitted to a pair of guide rails 32r provided on the base 2 in the Z1-axis direction, and a nut 32n is detachably fixed to the Z1-axis motor M12. The ball screw 32b is a machine component that operates the screw 32s and the nut 32n via balls (not shown). The screw 32s rotates about a center line oriented in the Z1 axis direction, and thereby moves the nut 32n in the Z1 axis direction. A Z1-axis motor M12 as a servo motor is provided on the base 2, and rotates and drives the screw 32s in accordance with a command from the NC apparatus 3. The headstock 10 is moved in the Z1 axis direction together with the Z1 axis direction slide table 32 by the ball screw 32 b.

Of course, instead of moving the X1 axis driving element in the Z1 axis direction by the Z1 axis driving element, the Z1 axis driving element may be moved in the X1 axis direction by the X1 axis driving element.

The tool post driving unit shown in fig. 1 includes an X2-axis driving element (an X2-axis motor M21, a ball screw 41b, and the like) for driving the X2-axis direction slide table 41 provided with the tool post 20 in the X2-axis direction, and a Z2-axis driving element (a Z2-axis motor M22, a ball screw 42b, and the like) for driving the Z2-axis direction slide table 42 provided with the X2-axis direction slide table 41 in the Z2-axis direction.

The X2 axial direction slide table 41 includes a pair of guide members 41g, and the pair of guide members 41g are slidably fitted to a pair of guide rails 41r provided in a Z2 axial direction slide table 42 described later so as to be able to slide in the X2 axial direction, and a nut 41n is detachably fixed to the X2 axial direction slide table 41. The ball screw 41b is a machine component that operates the screw 41s and the nut 41n via balls (not shown). The screw 41s rotates about a center line oriented in the X2 axis direction, and thereby moves the nut 41n in the X2 axis direction. An X2-axis motor M21 as a servo motor is provided on the Z2-axis direction slide table 42, and rotates the drive screw 41s in accordance with a command from the NC apparatus 3. The ball screw 41b moves the tool post 20 in the X2 axis direction together with the X2 axis direction slide table 41.

The Z2 axial slide base 42 includes a pair of guide members 42g, the pair of guide members 42g are fitted to a pair of guide rails 42r provided in the base 2 so as to be slidable in the Z2 axial direction, and a nut 42n is detachably fixed to the Z2 axial slide base 42. The ball screw 42b is a machine component that operates the screw 42s and the nut 42n via balls (not shown). The screw 42s rotates about a center line oriented in the Z2 axis direction, and thereby moves the nut 42n in the Z2 axis direction. A Z2-axis motor M22 as a servo motor is provided on the base 2, and rotates the drive screw 42s in accordance with a command from the NC apparatus 3. The tool post 20 is moved in the Z2 axis direction together with the Z2 axis direction slide table 42 by the ball screw 42 b.

Of course, instead of moving the X2 axis driving element in the Z2 axis direction by the Z2 axis driving element, the Z2 axis driving element may be moved in the X2 axis direction by the X2 axis driving element.

Further, the guide is a combination of the guide rail and the guide member, but the guide used for the machine tool is not limited to the combination of the guide rail and the guide member, and may be a combination of a wedge and a wedge groove.

Here, the base and the movable body of the present technology are determined according to the relative positional relationship. For example, when the movable body is the X1 axis direction slide table 31 provided with the headstock 10, the base is the Z1 axis direction slide table 32. When the moving body is the Z1 axis direction slide table 32, the base is the base 2. When the moving member is an X2 axis direction slide table 41 provided with the tool rest 20, the base is a Z2 axis direction slide table 42. When the moving body is the Z2 axis direction slide table 42, the base is the base 2.

Fig. 2A to 2D schematically show an example of a machine tool including a base 5, a moving body 6, a ball screw 7, a cap 8, and a support 9. Fig. 2A to 2D also schematically show an example of replacing the ball screw 7. Fig. 3 is an exploded view of an end portion 72 of the ball screw 7 and its periphery. Fig. 4 shows an example of the end portion 72 of the ball screw 7 and its periphery in a cross-sectional view at a1 position in fig. 2. Fig. 5 shows an example of the end portion 72 of the ball screw 7 and its periphery as viewed from the opening 96 side of the recess 95 of the support portion 9.

In these figures, the base 5 corresponds to any one of the base 2, the Z1 axial direction slide table 32, and the Z2 axial direction slide table 42 shown in fig. 1. The moving body 6 corresponds to any one of the X1 axis direction slide table 31 provided with the headstock 10, the Z1 axis direction slide table 32 provided with the X1 axis direction slide table 31, the X2 axis direction slide table 41 provided with the tool rest 20, and the Z2 axis direction slide table 42 provided with the X2 axis direction slide table 41. The ball screw 7 corresponds to any one of the ball screws 31b, 32b, 41b, and 42b shown in fig. 1. That is, the nut 7n of the ball screw 7 corresponds to any one of the nuts 31n, 32n, 41n, 42n, and the screw 7s of the ball screw 7 corresponds to any one of the screws 31s, 32s, 41s, 42 s. The servo motor M0 provided on the base 5 corresponds to any of the motors M11, M12, M21, and M22 shown in fig. 1.

As shown in fig. 2A and 4, the base 5 has a mounting portion 51 to which the support member 90 as an example of the support portion 9 is mounted by a plurality of screws SC 3. The mounting portion 51 has screw holes 52 to which the screws SC3 are screwed.

As shown in fig. 2A to 2D, the movable body 6 is disposed so as to be movable in a specific axial direction D1 and is disposed so as to be movable relative to the base 5. The axial direction D1 is a direction along the center line AX0 of the screw 7s of the ball screw 7. The moving body 6 includes a main body 61 and a bracket 62 having a through hole 63 for mounting the nut 7n of the ball screw 7. The bracket 62 protrudes downward from the main body 61, that is, protrudes toward the screw 7 s. The through hole 63 penetrates the bracket 62 in the axial direction D1. By inserting the nut 7n into the through hole 63 and fixing the bracket 62 with the screw SC1, the moving body 6 moves in both directions in the axial direction D1 together with the nut 7 n.

As shown in fig. 2A, the ball screw 7 includes a nut 7n and a screw 7s that are screwed together via balls (not shown). The screw 7s rotates about a center line AX0 oriented in the axial direction D1, and thereby moves the nut 7n fixed to the movable body 6 in the axial direction D1. One end 71 of the screw 7s is connected to a motor M0 via a coupling C0 as a torque transmission mechanism in the motor support member MS. A rolling bearing 73 is fitted to the other end 72 of the screw 7s and fixed thereto by a lock nut 74. In this state, the end portion 72 is inserted into the recess 83 of the main body 81 of the cap 8 and positioned by the support member 90 and the cap 8. As the bearing 73, a ball bearing, a roller bearing, or the like can be used.

The coupling C0 couples the shaft member Ma of the motor M0 and the end 71 of the screw 7s, and rotates about the center line AX0 as the shaft member Ma rotates, thereby rotating the screw 7 s. As the coupling C0, an expansion sleeve or the like having a hub coupled to a shaft (the shaft member Ma or the end portion 71) by fastening a screw may be used. The expansion sleeve is a wedge-shaped friction fastening element, and if the screw is fastened in the axial direction, the friction force between the shaft and the hub is increased, and the shaft is combined with the hub. The motor M0 is supported by a motor support member MS attached to the base 5, and rotates the drive screw 7s via a coupling C0 in accordance with a command from the NC apparatus 3. The ball screw 7 moves the moving body 6 in the axial direction D1 together with the nut 7 n.

As shown in fig. 3 to 5, the cap member 8 includes a main body 81 that enters the recess 95 of the support member 90, and a flange 85 that does not enter the recess 95 of the support member 90 and protrudes outward in the axial direction D1 from the main body 81 in the direction D1 o. The body 81 has a recess 83 having a circular cross section, and covers the end 72 of the screw 7s, and the recess 83 is inserted with the end 72 of the screw 7s externally fitted with the bearing 73. Thereby, the body 81 allows the screw 7s to rotate about the center line AX 0. The outer side surface 82 of the body 81 is circular in side view and slightly smaller than the curved surface of the recess 95 of the support member 90. This is because, in a state where the main body portion 81 is placed in the recess portion 95 and the flange portion 85 is brought into contact with the positioning portion 91 to determine the mounting posture of the ball screw 7, the position of the ball screw 7 in the direction orthogonal to the axial direction D1 (here, the direction D2 shown in fig. 3 and 4 and the direction D3 orthogonal to the two directions D1 and D2) is finely adjusted. Therefore, a slight gap is usually generated between the main body 81 and the recess 95. The flange portion 85 is radially expanded from the body portion 81 about the center line AX0, and has screw insertion holes 87 through which the plurality of screws SC2 are inserted in the axial direction D1. The inner side surface 86 of the flange portion 85 contacts the positioning portion 91 of the support member 90. The diameter of the screw insertion hole 87 is larger than the diameter of the screw SC 2. The reason is that, as described above, in a state where the mounting posture of the ball screw 7 is determined, the position of the ball screw 7 is finely adjusted, and the cap member 8 is fixed by the screw SC 2.

The recess 83 may enter the flange 85.

As shown in fig. 3 to 5, the support member 90 as an example of the support portion 9 includes screw holes 92 to which the respective screws SC2 are screwed, screw insertion holes 93 through which the plurality of screws SC3 are inserted, a recess 95 that receives the main body portion 81, and a planar positioning portion 91 with which the inner surface 86 of the flange portion 85 is brought into contact. In fig. 3, each screw SC2 is shown to be inserted through washer WA1 and screw insertion hole 87 to be screwed into screw hole 92. Each screw insertion hole 93 penetrates in a direction D2 perpendicular to the axial direction D1. The diameter of the screw insertion hole 93 is larger than the diameter of the screw SC 3. This is because the positioning portion 91 with which the inner side surface 86 of the flange portion 85 abuts is a vertical surface that determines the mounting posture of the ball screw 7, and the support member 90 is fixed by the screw SC 3. When the positioning portions 91 are vertical surfaces and the screws SC3 are screwed into the screw holes 52 of the mounting portion 51 of the base 5 through the screw insertion holes 93, the support member 90 is fixed to the mounting portion 51, and the cap member 8 is supported by the support member 90. The recess 95 has an opening 96 for receiving the body 81 of the cap 8, and the opening 96 is substantially U-shaped, and the body 81 of the cap 8 is inserted in a direction D2 perpendicular to the axial direction D1 in a state where the support member 90 is fixed to the mounting portion 51. As described above, the curved surface portion of the recess 95 is slightly larger than the outer surface 82 of the body 81. The opening 96 faces in the opposite direction to the base 5. Therefore, the opening 96 allows the screw 7s to pass through in the direction D2 orthogonal to the axial direction D1 in a state where the support member 90 is fixed to the mounting portion 51. The positioning portion 91 is positioned on the surface of the support member 90 on the outer side in the axial direction D1, and abuts against the inner side surface 86 of the flange portion 85 in the axial direction D1 in a state where the main body portion 81 is received in the recess 95.

(3) Specific examples of the method of replacing the ball screw:

an example of a method of replacing the ball screw 7 will be described below with reference to fig. 2A to 2D.

When the ball screw 7 is removed from the machine tool in the use state shown in fig. 2A, first, the screw SC1 is removed from the bracket 62 of the moving body 6, and the fixation between the bracket 62 and the nut 7n is released. Thereby, as shown in fig. 2B, the movable body 6 can be moved toward the support member 90 along the guide rail (not shown). Further, the screw coupling the one end 71 of the screw 7s to the coupler C0 is loosened, the screw SC2 located near the other end 72 of the screw 7s is removed, and the fixing of the support member 90 and the cap member 8 is released. Then, as shown in fig. 2C, the one end portion 71 of the screw 7s can be pulled out from the coupling C0, and the ball screw 7 can be pulled out to the outside D1o in the axial direction D1 to some extent together with the cap member 8. However, since the screw 7s penetrates the bracket 62 of the moving body 6 between the nut 7n and the cap 8, the ball screw 7 cannot be completely pulled out to the outside D1o in the axial direction D1. Of course, since the motor M0 and the motor support member MS as a large structure on the base 5 are present on the side of the one end 71 of the screw 7s, the ball screw 7 cannot be pulled out toward the motor M0 unless the screw 7s is inclined.

Here, the recess 95 of the support member 90 has an opening 96 through which the screw 7s passes in a direction D2 orthogonal to the axial direction D1 in a state where the support member 90 is attached to the base 5. As a result, as shown in fig. 2D, the one end portion 71 can be easily moved upward, that is, away from the base 5, so that the screw 7s is inclined toward the opening 96. By removing the cap member 8 from the other end 72 of the screw 7s, the other end 72 of the screw 7s can be pulled out from the through hole 63 of the bracket 62, and the ball screw 7 can be completely pulled out toward the motor M0.

As described above, when the ball screw 7 is removed from the machine tool, the ball screw 7 can be easily pulled out completely by tilting the screw 7s toward the opening 96 of the recess 95 without removing the support member 90 from the base 5.

When the ball screw 7 is attached to the machine tool, the work may be performed in the reverse order to the above-described removal order. First, as shown in fig. 2D, one end 71 of the screw 7s is inclined upward, and the other end 72 of the screw 7s is inserted through the through hole 63 of the bracket 62. Since the recess 95 of the support member 90 has the opening 96 on the inclined side of the screw 7s in the state where the support member 90 is attached to the base 5, there is no need to detach the support member 90 from the base 5. Next, as shown in fig. 2C, the cap member 8 is attached to the end portion 72 of the screw 7s, the end portion 71 of the screw 7s is inserted into the coupler C0, and the body portion 81 of the cap member 8 is placed in the recess 95 of the support member 90. Here, since the support member 90 is kept attached to the base 5, the positioning portion 91 of the support member 90 is kept vertical. Therefore, if the inner side surface 86 of the flange portion 85 is brought into contact with the positioning portion 91 of the support member 90 in the axial direction D1, the mounting posture of the ball screw 7 is determined. If the position of the ball screw 7 in the direction orthogonal to the axial direction D1 (here, the directions D2, D3 shown in fig. 3, 4) is finely adjusted in this state, and the cap member 8 is fixed by the screw SC2, the mounting of the ball screw 7 is ended.

In the case where the opening through which the screw rod passes is not provided in a state where the support member is attached to the base, the screw rod interferes with the support member, so that it is difficult to tilt the ball screw rod. In this case, in order to replace the ball screw, the support member needs to be removed from the base. However, when the support member is attached to the base by inserting one end of a new ball screw into the coupling, it is necessary to fix the support member to the base after performing adjustment such as checking the parallelism of the screw while performing axial feed motion using a micrometer or checking the attachment posture of the ball screw. Therefore, such work needs to be performed by a skilled or experienced worker.

In this specific example, since it is not necessary to detach the support member from the base when replacing the ball screw, it is not necessary to perform a skill or experience work such as adjusting or confirming the installation posture of the ball screw. Since the mounting posture of the ball screw is determined by bringing the flange portion of the cap into contact with the positioning portion of the support member, the worker only needs to finely adjust the position of the ball screw to fix the cap to the support member. Therefore, this specific example can reduce the work of replacing the ball screw without depending on the skill or experience of the operator.

As shown in fig. 4, since the recess 95 of the support member 90 has the opening 96, the support member 90 does not need to surround the screw 7s, and the height of the support member 90 can be made low. Therefore, the specific example can make the support part smaller.

(4) Variation example:

various variations are contemplated by the present invention.

For example, the machine tool may be a fixed-spindle NC lathe or the like.

The support portion 9 does not need to be detached from the base 5, and therefore may be formed integrally with the base 5.

The orientation of the opening 96 of the recess 95 of the support portion 9 is not limited to the orientation opposite to the base 5. For example, even if the opening of the recess of the support portion is oriented in the horizontal direction orthogonal to the axial direction D1, that is, in the direction of the base, by inclining the screw toward the opening side, the ball screw can be replaced without detaching the support portion from the base. Of course, the opening direction of the recess of the support portion may be a direction deviating from the vertical direction or the horizontal direction as long as the screw can pass through the opening.

The fixing of the cap member 8 to the support 9 is not limited to the fixing by the screw SC2, and may be performed by other cases, fixing by a claw member shown in fig. 6, or the like.

Fig. 6 shows another example of the state in which the cap member 8 is fixed to the support portion 9, as viewed from the flange portion 85 side. The support member 90 shown in fig. 6 has a plurality of claw members 110 which are movable obliquely. The flange 85 is held between the positioning portion 91 if each claw member 110 stands up like a solid line portion, and the holding of the flange 85 is released if it is laid down like a two-dot chain line portion. In this case, the mounting posture of the ball screw 7 is also determined by bringing the inner surface 86 of the flange portion 85 into contact with the positioning portion 91 of the support member 90 in the axial direction D1.

The outer surface of the main body of the cap member is not limited to a circular cross section, and similarly, the shape of the recess of the support portion is not limited. Fig. 7 is a cross-sectional view of the end of the ball screw and its periphery at position a1 in fig. 2. The recess 95 of the support member 90 shown in fig. 7 is rectangular in side view. The cap member 8 is shaped so as to fit the rectangular recess 95 below the outer surface 82 of the body 81. In this case, the mounting posture of the ball screw 7 is also determined by bringing the inner surface 86 of the flange portion 85 into contact with the positioning portion 91 of the support member 90 in the axial direction D1.

(5) To summarize:

as described above, according to the present invention, it is possible to provide a technique such as a machine tool which can reduce the work of replacing a ball screw in various forms. Of course, the basic operation and effect can be obtained by a technique including only the constituent elements related to the independent claims.

Further, a configuration in which the respective configurations disclosed in the above examples are replaced or changed and combined with each other, a configuration in which the respective configurations disclosed in the known art and the above examples are replaced or changed and combined with each other, and the like may be implemented. The present invention also includes the above-described configuration.

[ description of symbols ]

1 lathe (example machine tool)

2 base

5 base station

6 moving body

7 screw rod

7n nut

7s screw

8 Cap part

9 support part

51 mounting part

61 main body

62 bracket

63 through hole

71. 72 end part

73 bearing

74 locking nut

81 main body part

82 outer side

83 recess

85 flange part

86 medial side

90 support member

91 positioning part

95 concave part

96 opening

AX0 centerline

D1 axial direction

Outside of D1o

D2 is in a direction orthogonal to the axial direction.