Retap device

Abstract

The present invention provides a retapping device that can properly retap even when there is a misalignment in the planar position or tilt when the device is attached to a robot arm, or when the rotational speed (rotational phase) of the tap and the axial movement speed do not perfectly correspond. [Solution] The re-tapping device comprises a tap mounting section for mounting a tap for re-tapping, a spindle, a connecting section for connecting the tap mounting section and the spindle, a bearing that supports the spindle so as to be axially movable relative to the spindle and so as to be able to transmit rotational torque to the spindle, a mounting section for attaching the spindle to a robot via the bearing, a motor for rotating the bearing, a first elastic body that applies a first biasing force to the bearing in the axial direction, and a second elastic body that applies a second biasing force to the bearing in the same direction as the first biasing force.

Description

Technical Field

[0006] , ,

[0007] ,

[0001] One embodiment of the present invention relates to a retapping device that is attached to and used on a robot arm.

Background Art

[0002] When threading holes are drilled in a metal material or a resin material, etc., foreign substances such as paint may remain in the threaded hole portion. Therefore, retapping is performed by passing a tap for removing foreign substances through the threaded hole.

[0003] For example, Patent Document 1 discloses a method for removing paint adhering to a female screw portion. The invention described in Patent Document 1 removes the paint film formed on the female screw portion by inserting a tap for removing paint while rotating it with respect to the female screw portion.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] If the position or angle at which the tap for retapping is inserted is deviated, the removal of foreign substances becomes insufficient, and there is a problem that the function as a female screw cannot be fully exhibited. There is also a problem that damage to the female screw occurs and the female screw surface is damaged.

[0006] Also, when the rotational speed (rotational phase) of the tap by the motor does not correspond to the moving speed in the axial direction of the tap, a load may be generated on the female screw, and there is a possibility that the female screw surface is damaged.

[0007] In particular, it is difficult for robot arms to completely eliminate deviations in planar position and angle. Furthermore, it is difficult for robot arms to perfectly match the axial movement speed to the rotation speed of the tap. Therefore, retapping was difficult to automate with robot arms and required skilled workers to perform the task manually.

[0008] One embodiment of this invention aims to provide a retapping device that can perform retapping appropriately even when there is a misalignment of the planar position or tilt when attached to a robot arm, or when the rotational speed (rotational phase) of the tap and the axial movement speed do not perfectly correspond. [Means for solving the problem]

[0009] The re-tapping device comprises a tap mounting section for mounting a tap for re-tapping, a spindle, a connecting section for connecting the tap mounting section and the spindle, a bearing that supports the spindle so as to be axially movable relative to the spindle and so as to be able to transmit rotational torque to the spindle, a mounting section for attaching the spindle to a robot via the bearing, a motor for rotating the bearing, a first elastic body that applies an axial biasing force to the bearing, and a second elastic body that applies a second biasing force to the bearing in the same direction as the first biasing force. The connecting section has a first joint section attached to the spindle, a second joint section attached to the tap mounting section, and a third elastic body. The first and second joint sections are connected to the spindle and the tap mounting section, respectively, so as to be able to pitch and yaw in the axial direction. The third elastic body applies a third biasing force to the first and second joints to return the pitching and yawing to a reference angle.

[0010] In this embodiment, the retapping device allows the spindle to be shifted axially by the bearing even when the tap is inserted into the female thread and the spindle's rotational speed (rotational phase) and axial movement speed do not perfectly correspond. Furthermore, since the first and second elastic bodies generate a biasing force against the axial movement of the bearing, the spindle returns to its reference position when the tap is removed from the female thread.

[0011] Furthermore, in the retapping device of this embodiment, the first joint and the second joint are connected to the spindle and the tap mounting section so that they can pitch and yaw in the axial direction, respectively, thus absorbing deviations in planar position and tilt. The third elastic body generates a third biasing force to return the pitching and yaw to the reference angle, so that when the tap is removed from the female thread, the planar position and tilt of the tap return to the reference state.

[0012] Preferably, the first and second elastic bodies are made of springs, and the third elastic body is made of tubular synthetic rubber.

[0013] The first joint and the second joint may be made of a single component, or they may be made of separate components and joined together. [Effects of the Invention]

[0014] The retapping device according to this embodiment can perform retapping appropriately even when there is a misalignment of the planar position or tilt when attached to a robot arm, or when the rotational speed (rotational phase) of the tap and the axial movement speed do not perfectly correspond. [Brief explanation of the drawing]

[0015] [Figure 1] This is a front view of the retapping device. [Figure 2] This is a left side view of a re-tapping device. [Figure 3] Figure 2 is a cross-sectional view of the BB line. [Figure 4] This is a cross-sectional view of line AA shown in Figure 1. [Figure 5] It is a schematic cross-sectional view for explaining the functions of the first joint portion 20 and the second joint portion 21. [Figure 6] It is a schematic cross-sectional view for explaining the functions of the first joint portion 20 and the second joint portion 21.

Embodiments for Carrying out the Invention

[0016] FIG. 1 is a front view of the retapping device of the present embodiment, and FIG. 2 is a left side view. FIG. 3 is a cross-sectional view taken along line A-A shown in FIG. 1, and FIG. 4 is a cross-sectional view taken along line B-B shown in FIG. 2. In the present embodiment, for convenience of explanation, the right direction of the retapping device is referred to as the X direction, the left direction as the -X direction, the back direction as the Y direction, the front direction as the -Y direction, the upward direction as the Z direction, and the downward direction as the -Z direction.

[0017] The retapping device includes a tap mounting portion 11, a spindle 12, a mounting portion 13, a connecting portion 14, a bearing 15, a first elastic body 16, a second elastic body 17, and a motor 18.

[0018] The tap mounting portion 11 mounts a tap 10 for retapping. The spindle 12 has a columnar or cylindrical shape that is long in the Z direction. A plurality of protrusions that are long in the Z-axis direction and short in the circumferential direction are provided at a plurality of locations on the outer periphery of the spindle 12. The connecting portion 14 connects the lower tip of the spindle 12 and the upper tip of the tap mounting portion 11. The connecting portion 14 connects the spindle 12 and the tap mounting portion 11 so that the axes of the spindle 12 and the tap 10 coincide in the reference state.

[0019] A bearing 15 is mounted on the outer circumference of the spindle 12. The bearing 15 is, for example, a rotary ball spline, and supports the spindle 12 so as to be movable in the axial direction relative to the spindle 12 and so as to be able to transmit rotational torque to the spindle 12. More specifically, the bearing 15 has a plurality of balls that clamp in the circumferential direction onto projections provided at multiple locations on the outer circumference of the spindle 12, and supports the spindle 12 so as to be movable in the axial direction relative to the spindle 12 and so as to be able to transmit rotational torque to the spindle 12 via these plurality of balls. A gear 151 is provided on the outer circumference of the bearing 15. The gear 151 meshes with a gear 181 mounted on the shaft of the motor 18. As a result, the spindle 12 rotates in synchronization with the rotation of the motor 18.

[0020] The mounting portion 13 is a component for attaching the spindle 12 to the robot via the bearing 15. The mounting portion 13 also serves as a case covering the top of the bearing 15. The mounting portion 13 moves the bearing 15 in accordance with the movement of the robot. More specifically, the mounting portion 13 can move the bearing 15 axially (Z-axis direction) and in planar directions (XY plane direction) as the 6-axis articulated robot moves, and can also pitch, yaw, and roll around the Z-axis. The mounting portion 13 is also attached to the case of the bearing 15 so that the spindle 12 can rotate in the X-axis direction.

[0021] The first elastic body 16 is disposed on the upper end surface of the upper case of the bearing 15. The second elastic body 17 is disposed on the lower end surface of the lower case of the bearing 15. The first elastic body 16 and the second elastic body 17 are cylindrical elastic bodies. The first elastic body 16 and the second elastic body 17 are arranged to cover the side surface of the spindle 12. In this embodiment, the first elastic body 16 and the second elastic body 17 are constituted by coil springs. The first elastic body 16 and the second elastic body 17 generate a biasing force in the axial direction of the bearing 15 by being compressed or extended in the axial direction. The first elastic body 16 and the second elastic body 17 may have a configuration other than a coil spring. The first elastic body 16 and the second elastic body 17 may be, for example, synthetic rubber, may generate a biasing force by magnetic force, or may generate a biasing force by compressed fluid (air, hydraulic pressure, or water pressure). However, by using coil springs for the first elastic body 16 and the second elastic body 17, it is possible to increase the amount of compression or extension in the axial direction while having a simple configuration, and it is also possible to prevent deterioration over time.

[0022] The first elastic body 16 applies a first biasing force to the bearing 15 in the axial direction. The second elastic body 17 applies a second biasing force to the bearing 15 in the axial direction in the same direction as the first biasing force. That is, when the first elastic body 16 is compressed to generate a biasing force in the Z direction, the second elastic body 17 is extended to generate a biasing force in the -Z direction. When the first elastic body 16 is extended to generate a biasing force in the Z direction, the second elastic body 17 is compressed to generate a biasing force in the -Z direction. Thereby, when the bearing 15 receives a load in the Z direction or the -Z direction, it moves in the Z direction or the -Z direction with respect to the reference position, but returns to the reference position when the load disappears.

[0023] The spindle 12 rotates in sync with the rotation of the motor 18. When the tap 10 is inserted into the female screw, it moves axially along with the rotation of the spindle 12 due to the grooves of the female screw. The robot moves the spindle 12 axially at a speed corresponding to the amount of axial movement of the tap 10 caused by the rotation of the spindle 12. If the first elastic body 16 and the second elastic body 17 were absent and the spindle and bearing were fixed axially, and the rotational speed (rotational phase) of the spindle 12 did not correspond to the axial movement speed, the tap 10 could load the female screw and potentially damage it.

[0024] In contrast, in this embodiment of the retapping device, since the bearing 15 is movable axially relative to the spindle 12, even if the rotational speed (rotational phase) and axial position of the spindle 12 do not perfectly correspond, the tap 10 moves to the appropriate position and does not apply a large load to the female thread. Furthermore, the first elastic body 16 and the second elastic body 17 generate a biasing force against the axial movement of the bearing 15, so that when the tap 10 is removed from the female thread, the spindle 12 returns to its reference position.

[0025] Next, the connecting portion 14 will be described. As shown in the cross-sectional views of Figures 3 and 4, the connecting portion 14 has a first joint portion 20 attached to the spindle 12, a second joint portion 21 attached to the tap mounting portion 11, and a third elastic body 22. The first joint portion 20 and the second joint portion 21 have the same shape and are joined symmetrically to each other. However, the first joint portion 20 and the second joint portion 21 may be a single integrated shape. The third elastic body 22 is a cylindrical synthetic rubber (urethane rubber as an example). The third elastic body 22 is positioned to cover the sides of the first joint portion 20 and the second joint portion 21. The third elastic body 22 may be a coil spring, but if it is a cylindrical synthetic rubber, it has a higher restoring force against planar displacement than a coil spring.

[0026] The first joint portion 20 and the second joint portion 21 are connected to the spindle 12 and the tap mounting portion 11, respectively, so that they can pitch and yaw with respect to the axial direction (Z-axis direction) of the spindle 12.

[0027] Figures 5 and 6 are schematic cross-sectional diagrams illustrating the functions of the first joint portion 20 and the second joint portion 21. If the planar position of the tap is misaligned with the position of the female thread, and the first joint portion 20 and the second joint portion 21 are absent, the tap may apply load to the female thread, potentially damaging it.

[0028] However, in the retapping device of this embodiment, as shown in Figure 5, the first joint portion 20 and the second joint portion 21 are each tilted with respect to the axial direction (Z-axis direction) of the spindle 12, thereby offsetting the planar position of the spindle 12 axis and the tap 10 axis.

[0029] Furthermore, as shown in Figure 6, in the retapping device of this embodiment, the axis of the tap 10 can be tilted with respect to the axis of the spindle 12 by tilting either one or both of the first joint portion 20 and the second joint portion 21 in the same direction with respect to the axial direction (Z-axis direction) of the spindle 12.

[0030] Furthermore, the third elastic body 22 generates a restoring force that attempts to return to its cylindrical shape when deformed. This restoring force provides a third biasing force to the first joint portion 20 and the second joint portion 21, causing the tilt due to pitching and yawing to return to the reference angle. For example, if the planar positions of the spindle 12 axis and the tap 10 axis are offset as shown in Figure 5, the third elastic body 22 provides a biasing force that returns the offset to its original position. Also, if the tap 10 axis is tilted relative to the spindle 12 axis as shown in Figure 6, the third elastic body 22 provides a biasing force that returns the tilt to its original angle. Therefore, when the tap 10 is removed from the female thread, the tap mounting portion 11 and the tap 10 return to their reference positions, and the axis of the tap 10 returns to a state where it coincides with the axis of the spindle 12.

[0031] The description of this embodiment should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims, rather than by the embodiments described above. Furthermore, the scope of the invention includes the scope equivalent to the claims. [Explanation of Symbols]

[0032] 10: Tap 11: Tap mounting section 12: Spindle 13: Mounting part 14: Connection part 15: Bearings 16: First elastic body 17: The second elastic body 18: Motor 20: First joint section 21: Second joint section 22: The third elastic body 151: Gear 181: Gear

Claims

1. A tap mounting section for attaching a tap for re-tapping, Spindle and, A connecting portion that connects the tap mounting portion and the spindle, A bearing that supports the spindle so as to be movable in the axial direction relative to the spindle and so as to be able to transmit rotational torque to the spindle, A mounting portion for attaching the spindle to the robot via the bearing, A motor that rotates the aforementioned bearing, A first elastic body that applies a first biasing force in the axial direction to the bearing, A second elastic body that applies a second biasing force to the bearing in the same direction as the first biasing force, A retapping device equipped with, The connecting portion includes a first joint portion attached to the spindle, a second joint portion attached to the tap mounting portion, and a third elastic body. The first joint and the second joint are connected to the spindle and the tap mounting portion, respectively, so that they can pitch and yaw in the axial direction. The third elastic body provides a third biasing force to the first joint and the second joint to return the pitching and yawing to the reference angles. A re-tapping device is provided.

2. The first elastic body and the second elastic body are made of coil springs. The retapping device according to claim 1.

3. The third elastic body is made of tubular synthetic rubber. The retapping device according to claim 1 or claim 2.

4. The first joint portion and the second joint portion are made of separate members and are joined to each other. The retapping device according to claim 1 or claim 2.

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