Retapping device

Abstract

To provide a retapping device that can properly perform retapping even when a deviation in planar position or inclination occurs when attached to a robot arm, or when the rotation speed (rotation phase) of the tap does not perfectly correspond to the moving speed in the axial direction. [Solution] The retapping device comprises a tap mounting portion for mounting a tap for retapping, a spindle, a connection portion for connecting the tap mounting portion and the spindle, a bearing for supporting the spindle so that it can move axially relative to the spindle and transmit rotational torque to the spindle, a mounting portion for attaching the spindle to a robot via the bearing, a motor for rotating the bearing, a first elastic body that applies a first 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.

Description

[Technical Field]

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

[0002] When threaded holes are drilled into metal or resin materials, foreign matter such as paint may remain in the threaded hole. In such cases, a tap is passed through the threaded hole to remove the foreign matter, and retapping is performed.

[0003] For example, Patent Document 1 discloses a method for removing paint adhering to a female thread. The invention described in Patent Document 1 removes the paint film formed on the female thread by inserting a paint removal tap into the female thread while rotating it. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-44575 Summary of the Invention [Problem to be solved by the invention]

[0005] If the insertion position or angle of the retapping tap is off, foreign matter is not sufficiently removed, resulting in problems such as the inability to fully function as a female thread and damage to the female thread surface.

[0006] Furthermore, if the rotation speed (rotation phase) of the tap driven by the motor does not correspond to the axial movement speed of the tap, it may cause a load on the female thread and damage the female thread surface.

[0007] In particular, it is difficult to completely eliminate misalignment of the robot arm's planar position and angle. It is also difficult to perfectly match the axial movement speed of the robot arm with the rotation speed of the tap. Therefore, retapping is difficult to automate using a robot arm, and has had to be done manually by skilled workers.

[0008] One of the present embodiments aims to provide a retapping device that can perform appropriate retapping even when there is a deviation in planar position or inclination 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 retapping device includes a tap mounting portion for mounting a tap for retapping, a spindle, a connection portion connecting the tap mounting portion and the spindle, a bearing supporting the spindle so as to be axially movable relative to the spindle and capable of transmitting rotational torque to the spindle, a mounting portion for mounting the spindle to a robot via the bearing, a motor for rotating the bearing, a first elastic body applying an axial biasing force to the bearing, and a second elastic body applying a second biasing force to the bearing in the same direction as the first biasing force. The connection portion has 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 portion and the second joint portion are connected to the spindle and the tap mounting portion so as to be capable of pitching and yawing in the axial direction, respectively. The third elastic body applies a third biasing force to the first joint and the second joint to return the pitching and yawing to reference angles.

[0010] The retapping device of this embodiment can shift the axial position of the spindle using the bearings even when the tap is inserted into the female thread and the rotational speed (rotational phase) of the spindle does not perfectly correspond to the axial movement speed. In addition, because the first elastic body and the second elastic body generate a biasing force against the axial movement of the bearings, 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 portion and the second joint portion are connected to the spindle and the tap mounting portion so that they can pitch and yaw in the axial direction, respectively, so that deviations in planar position and tilt can also be absorbed. The third elastic body generates a third biasing force for returning the pitch 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] It is preferable that the first elastic body and the second elastic body are springs, and the third elastic body is made of cylindrical synthetic rubber.

[0013] The first joint portion and the second joint portion may be one member, but may also be separate members joined together. [Effects of the Invention]

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

[0015] [Figure 1] FIG. [Figure 2] FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the line BB shown in FIG. [Figure 4] FIG. 2 is a cross-sectional view taken along the line AA shown in FIG. [Figure 5] 2 is a schematic cross-sectional view for explaining the functions of a first joint portion 20 and a second joint portion 21. FIG. [Figure 6] 2 is a schematic cross-sectional view for explaining the functions of a first joint portion 20 and a second joint portion 21. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Figure 1 is a front view of the retapping device of this embodiment, and Figure 2 is a left side view. Figure 3 is a cross-sectional view taken along line AA shown in Figure 1, and Figure 4 is a cross-sectional view taken along line BB shown in Figure 2. For ease of explanation, in this embodiment, the right direction of the retapping device will be 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 up direction as the Z direction, and the down direction as the -Z direction.

[0017] The retapping device has 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 part 11 mounts a tap 10 for retapping. The spindle 12 has a columnar or cylindrical shape that is long in the Z direction. Protrusions that are long along the Z axis direction and short in the circumferential direction are provided at multiple locations on the outer periphery of the spindle 12. The connecting part 14 connects the lower tip of the spindle 12 to the upper tip of the tap mounting part 11. The connecting part 14 connects the spindle 12 and the tap mounting part 11 so that the axes of the spindle 12 and the tap 10 are aligned in the standard state.

[0019] A bearing 15 is attached to the outer periphery 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 to be able to transmit rotational torque to the spindle 12. More specifically, the bearing 15 has a plurality of balls that circumferentially sandwich protrusions provided at multiple locations on the outer periphery of the spindle 12, and supports the spindle 12 so as to be movable in the axial direction relative to the spindle 12 and to be able to transmit rotational torque to the spindle 12 via the plurality of balls. A gear 151 is provided on the outer periphery of the bearing 15. The gear 151 meshes with a gear 181 attached to 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 part 13 is a component for mounting the spindle 12 to the robot via the bearing 15. The mounting part 13 also serves as a case that covers the upper part of the bearing 15. The mounting part 13 moves the bearing 15 in accordance with the movement of the robot. More specifically, the mounting part 13 can move the bearing 15 in the axial direction (Z-axis direction) and in the planar direction (XY plane direction) as the six-axis articulated robot moves, and can pitch, yaw, and roll around the Z-axis. The mounting part 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 case above the bearing 15. The second elastic body 17 is disposed on the lower end surface of the case below 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 disposed so as to cover the side surfaces of the spindle 12. In this embodiment, the first elastic body 16 and the second elastic body 17 are formed 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 when compressed or expanded in the axial direction. The first elastic body 16 and the second elastic body 17 may be formed by a material other than a coil spring. The first elastic body 16 and the second elastic body 17 may be formed by, for example, synthetic rubber, or 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, the amount of compression or expansion in the axial direction can be increased while maintaining a simple configuration, and deterioration over time can also be prevented.

[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, which is the same direction as the first biasing force. That is, when the first elastic body 16 is compressed and generates a biasing force in the Z direction, the second elastic body 17 is stretched and generates a biasing force in the -Z direction. When the first elastic body 16 is stretched and generates a biasing force in the Z direction, the second elastic body 17 is compressed and generates a biasing force in the -Z direction. As a result, when the bearing 15 is subjected to a load in the Z direction or the -Z direction, it moves in the Z direction or the -Z direction relative to a reference position, but returns to the reference position when the load is removed.

[0023] The spindle 12 rotates in synchronization with the rotation of the motor 18. When the tap 10 is inserted into the female thread, it moves axially as the spindle 12 rotates due to the grooves in the female thread. The robot moves the spindle 12 in the axial direction at a moving speed that corresponds to the 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 not present and the spindle and bearing were fixed in the axial direction, and the rotational speed (rotation phase) of the spindle 12 did not correspond to the axial movement speed, the tap 10 would apply a load to the female thread, potentially damaging the female thread.

[0024] In contrast, in the retapping device of this embodiment, the bearing 15 is movable in the axial direction relative to the spindle 12, so even if the rotational speed (rotational phase) and axial position of the spindle 12 do not perfectly correspond, the tap 10 moves to an 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 the spindle 12 returns to its reference position when the tap 10 is removed from the female thread.

[0025] Next, the connection portion 14 will be described. As shown in the cross-sectional views of FIGS. 3 and 4, the connection 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 so as to be symmetrical to each other. However, the first joint portion 20 and the second joint portion 21 may be integrally formed. The third elastic body 22 is a cylindrical synthetic rubber (urethane rubber, for example). The third elastic body 22 is arranged to cover the side surfaces of the first joint portion 20 and the second joint portion 21. The third elastic body 22 may be a coil spring; however, if it is a cylindrical synthetic rubber, it has a higher restoring force against misalignment in a planar direction than a coil spring.

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

[0027] 5 and 6 are cross-sectional schematic diagrams for explaining 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 not present, the tap may apply a 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 part 20 and the second joint part 21 are each tilted relative to the axial direction (Z-axis direction) of the spindle 12, thereby offsetting the planar positions of the axis of the spindle 12 and the axis of the tap 10.

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

[0030] The third elastic body 22 generates a restoring force that attempts to return the first joint 20 and the second joint 21 to their cylindrical shape when deformed. The third elastic body 22 applies a third biasing force to the first joint 20 and the second joint 21 to return the tilt caused by pitching and yawing to a reference angle by the restoring force. For example, if the planar positions of the axis of the spindle 12 and the axis of the tap 10 are offset as shown in FIG. 5, the third elastic body 22 applies a biasing force that returns the offset to its original position. Furthermore, if the axis of the tap 10 is tilted relative to the axis of the spindle 12 as shown in FIG. 6, the third elastic body 22 applies a biasing force that returns the tilt to its original angle. Therefore, when the tap 10 is removed from the female thread, the tap attachment portion 11 and the tap 10 return to their reference positions, and the axis of the tap 10 returns to being aligned with the axis of the spindle 12.

[0031] The description of the present embodiment should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined not by the above-described embodiments but by the claims. Furthermore, the scope of the present invention includes the scope equivalent to the claims. [Explanation of symbols]

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

Claims

1. a tap mounting portion for mounting a tap for retapping; A spindle and a connection portion that connects the tap mounting portion and the spindle; a bearing that supports the spindle so as to be axially movable relative to the spindle and to be able to transmit rotational torque to the spindle; a mounting portion for mounting the spindle to a robot via the bearing; a motor that rotates the bearing; a first elastic body that applies a first biasing force to the bearing in an axial direction; 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 comprising: the connecting portion has 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 portion and the second joint portion are connected to the spindle and the tap mounting portion so as to be able to pitch and yaw relative to the axial direction, respectively; the third elastic body applies a third biasing force to the first joint portion and the second joint portion to return the pitching and yawing angles to reference angles. A re-tapping device comprising:

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

3. the third elastic body is made of a cylindrical synthetic rubber; The retapping device according to claim 1 or 2.

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

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