TWI741725B - Fastening device and robot equipped with it - Google Patents

Abstract

The fastening device of the present invention is used to fasten the fastening member to the fastening position by rotating the drive shaft by rotating it, and is characterized in that it has: a rack and pinion mechanism; and a rotation The shaft, which is installed on the drive shaft via a rack and pinion mechanism, has a coupling part that is combined with a fastening member at its front end; the rack and pinion mechanism has: a base; a rack, which is movably mounted on the base ; Pinion, which is rotatably arranged on the base and engages with the rack; a pushing mechanism, which pushes the rack to one of the moving directions; and a sensor, which is used to detect that the rack has moved from the base The predetermined position is moved; one of the base and the pinion is fixed to the drive shaft, and the other of the base and the pinion is fixed to the rotating shaft.

Description

Fastening device and robot equipped with it

The present invention relates to a fastening device and a robot provided with the fastening device.

In the past, there is known a fastening device for fastening a fastening member at a fastening position by rotating the drive shaft by the rotational driving force. Such a fastening device is proposed in the thread inspection device of Patent Document 1, for example.

The thread inspection device of Patent Document 1 is a thread passing gauge that advances in the female thread. When an abnormal torque that exceeds a predetermined value is generated before reaching the specified amount of rotation, it is determined as a defective product, and the abnormal torque is not generated. In the case of the specified amount of rotation, it is judged to be a good product. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Laid-Open No. 10-138058

[The problem to be solved by the invention]

However, the conventional fastening device proposed in Patent Document 1 may damage the fastening member and the fastening position.

Therefore, an object of the present invention is to provide a fastening device capable of suppressing the possibility of damage to the fastening member and the fastening position, and a robot including the fastening device. [Means to Solve the Problem]

In order to solve the above-mentioned problems, the fastening device of the present invention is used to fasten the fastening member to the fastening position by rotating the drive shaft by the rotational driving force, and is characterized by having: a rack and a small A gear mechanism; and a rotating shaft, which is mounted to the drive shaft via the rack and pinion mechanism, has a coupling portion coupled with the fastening member at its front end, and the rack and pinion mechanism has: a base; a rack , Which is movably mounted on the above-mentioned base; a pinion, which is rotatably arranged on the above-mentioned base and engages with the above-mentioned rack; a pushing mechanism which pushes the above-mentioned rack to one of the moving directions; and A sensor for detecting that the rack has moved from a predetermined position of the base, one of the base and the pinion is fixed to the drive shaft, and the other of the base and the pinion is Fixed to the above-mentioned rotating shaft.

The torque that acts around the above-mentioned rotating shaft by the rotational driving force of the drive shaft is referred to as the first torque. In addition, the torque that acts around the above-mentioned rotating shaft by the pressing force of the pressing mechanism is referred to as the second torque. The drive shaft is rotationally driven with a second torque that is less than the first torque and works around the rotation shaft in a direction opposite to the first torque, whereby at least the base, rack, pinion, and rotation shaft are connected with each other. The above-mentioned drive shaft rotates integrally. In this state, if a third torque greater than the second torque acts around the rotation shaft via the fastening member, the rack resists the pressing force of the pressing mechanism and rotates around the pinion gear relative to the pinion gear. And move. As a result, after the third torque is exerted around the rotation shaft, even if the drive shaft continues to rotate for a predetermined time, the rotation is absorbed by the movement of the rack, so it will not be transmitted to the rotation shaft and the fastening member . As a result, the fastening device of this embodiment can suppress the risk of damage to the fastening position due to the fastening member. [Effects of Invention]

According to the present invention, it is possible to provide a fastening device capable of suppressing the possibility of damage to the fastening member and the fastening position, and a robot including the fastening device.

Hereinafter, the fastening device of the embodiment of the present invention and the robot provided with it will be described based on the drawings. In addition, the present invention is not limited by this embodiment. In addition, the same or equivalent elements are denoted by the same reference signs in all the following figures, and their repetitive descriptions are omitted.

(Robot 10) Fig. 1 is a schematic front view showing the overall configuration of a robot equipped with a fastening device of this embodiment. As shown in FIG. 1, the fastening device 30A of this embodiment and the robot 10 provided with it are arrange|positioned adjacent to the mounting table S on which the workpiece|work W is mounted. In addition, the fastening device 30A of the present embodiment and the robot 10 equipped with it are used to perforate the bolt hole H in the workpiece W, and to detect whether the bolt hole H is good or bad.

The robot 10 of the present embodiment includes a base 12, and a first robot arm 20a and a second robot arm 20b supported by the base 12 (hereinafter may be referred to as a "pair of robot arms 20a, 20b"). In addition, the robot 10 further includes a fastening device 30A attached to the front end of the first robot arm 20a, and a threading device 88 attached to the front end of the second robot arm 20b. In addition, the robot 10 further includes a robot control device 90 (refer to FIG. 2) for controlling the operations of the first robot arm 20 a, the second robot arm 20 b, and the fastening device 30A.

(A pair of robotic arms 20a, 20b) The pair of robot arms 20a and 20b are supported by the base 12, respectively. The pair of robot arms 20a and 20b can operate independently or in relation to each other. In addition, the second robot arm 20b has the same configuration as the first robot arm 20a. Therefore, only the first robot arm 20a will be described here, and the same description of the second robot arm 20b will not be repeated.

The first robot 20a has joint axes JT1 to JT4. In addition, servo motors 96 a to 96 d (first servo motors) for rotation driving are provided on the first robot arm 20 a so as to correspond to the joint axes JT1 to JT4. The first robot arm 20a has a first link 22, a second link 24, and a wrist 26.

The first connecting member 22 is connected to the base shaft 14 fixed to the upper surface of the base 12 by a rotary joint shaft JT1, thereby being able to rotate around an axis extending in the vertical direction defined by the axis of the base shaft 14 . The rotation of the first link 22 with respect to the base shaft 14 is performed by the servo motor 96a (refer to FIG. 2).

The second connecting member 24 is connected to the front end of the first connecting member 22 by a rotating joint shaft JT2, thereby being able to rotate around an axis that is defined by the front end of the first connecting member 22 and extending in the vertical direction. The rotation of the second link 24 with respect to the first link 22 is performed by the servo motor 96b (same as above).

The wrist 26 is connected to the front end of the second connecting member 24 by a linear motion type joint axis JT3. The wrist 26 can move up and down relative to the second link 24 by the linear motion type joint axis JT3. The lifting operation of the wrist 26 with respect to the second link 24 is performed by the servo motor 96c (refer to FIG. 2).

The wrist 26 has a mechanical interface 28 at its front end. A fastening device 30A is installed on the mechanical interface 28. The mechanical interface 28 can be rotated relative to the wrist 26 about an axis extending in the vertical direction by the rotary joint axis JT4. The rotation of the mechanical interface 28 relative to the wrist 26 is performed by the servo motor 96d (same as above).

The axis of the base end side of the first link 22 of the first robot arm 20a and the axis of the base end side of the first link 22 of the second robot arm 20b are located on the same straight line. In addition, the first link 22 of the first robot arm 20a and the first link 22 of the robot arm 20b are arranged with a height difference. Furthermore, regarding the second robot arm 20b, the rotation of the first link 22 with respect to the base shaft 14 is performed by the servo motor 96e (the first servo motor. Refer to FIG. 2), and the second link 24 is relative to the first link. The rotation of the piece 22 is performed by the servo motor 96f (same as above). Furthermore, regarding the second robot arm 20b, the lifting motion of the wrist 26 relative to the second link 24 is performed by the servo motor 96g (same as above), and the rotation motion of the mechanical interface 28 relative to the wrist 26 is performed by the servo motor. 96h (same as above). In other words, the rotation of the joint axis JT4 (drive axis, wrist axis) of the second robot arm 20b is performed by the servo motor 96h.

(Robot control device 90) Fig. 2 is a block diagram showing the control system of the robot equipped with the fastening device of this embodiment. As shown in FIG. 2, the robot control device 90 has a memory 92 for storing programs, and a processor 94 for executing the programs stored in the memory 92. The processor 94 is connected to the servo motors 96a to 96h of the pair of robot arms 20a and 20b, the servo motor 98 described below, the detection unit 64 for the first rack 40a, and the detection unit for the second rack 40b Each of 64. In addition, in FIG. 2, in order to avoid complicated appearance, only the detection part 64 for the first rack 40a is shown, and the illustration of the detection part 64 for the second rack 40b is omitted.

The robot control device 90 can servo-control the movement of the pair of robot arms 20a and 20b by the servo motors 96a-96h. In addition, the robot control device 90 can servo-control the operation of the fastening device 30A by the servo motor 96h.

(Tightening device 30A) Fig. 3 is a schematic diagram showing the fastening device of this embodiment, (A) is a diagram showing a state where the fastening device does not hold the fastening member, and (B) is a diagram showing a state where the fastening device holds the fastening member. As shown in FIG. 3, the base end of the rotary joint 100 is installed on the mechanical interface 28, and the base end of the tool changer 102 is installed on the front end of the rotary joint 100. In addition, the fastening device 30A of this embodiment is detachably installed at the front end of the tool changer 102.

The fastening device 30A includes: a rack and pinion mechanism 32; a rotating shaft 80 that is coaxially attached to the joint shaft JT4 via the rack and pinion mechanism 32; and a holding mechanism 82 (joint portion) for holding The gauge G (fastening member) is provided at the front end of the rotating shaft 80. In this embodiment, a rotary actuator is used as the rack and pinion mechanism 32.

(Rotating shaft 80 and holding mechanism 82) The base end of the rotating shaft 80 is fixed to a pinion 50 described below of the rack and pinion mechanism 32. The holding mechanism 82 provided at the front end of the rotating shaft 80 has a cylindrical holding mechanism main body 83 and a pair of first members 84 a and 84 b attached to the holding mechanism main body 83. The holding mechanism 82 can be combined with the gauge G by clamping and holding the base end portion of the gauge G with a pair of first members 84a and 84b.

The first member 84 a fixes its base end portion to a first holding rack (not shown) provided in the holding mechanism main body 83, and its front end portion protrudes from the front end side of the holding mechanism main body 83. The base end of the first member 84b is fixed to the second holding rack (same as above) provided in the holding mechanism main body 83, and the front end of the first member 84b protrudes from the front end of the holding mechanism main body 83 and is parallel to the first member 84a extend.

A holding pinion (not shown) is provided in the holding mechanism main body 83. One side part in the diameter direction of the holding pinion (here, any side part in the height direction in FIG. 3) engages the first holding rack. In addition, the second holding rack is engaged with the other side part in the diameter direction of the holding pinion (here, any other side part in the height direction in FIG. 3).

In addition, it is configured to change the interval between the pair of first members 84a and 84b by rotating the holding pinion to move the first and second holding racks in the holding mechanism main body 83 to opposite sides. The rotation of the holding pinion is performed by the servo motor 98 (refer to FIG. 2). By changing the interval between the pair of first members 84a and 84b in the above-described manner, the holding mechanism 82 can sandwich and hold the base end portion of the gauge G by the pair of first members 84a and 84b.

(Rack and pinion mechanism 32) Figure 4 is a cross-sectional view of the rack and pinion mechanism of the fastening device of this embodiment, (A) is a cross-sectional view along the height direction, (B) is along the IVB-IVB line shown in (A)的sectional view. As shown in FIG. 4, the rack and pinion mechanism 32 has a cuboid-shaped housing 34 (base), a first rack 40a (rack) and a first rack 40a (rack) that are movably installed in the housing 34. 2 a rack 40b, and a pinion gear 50 extending from the top plate 36a in the center of the housing 34 in the height direction described below.

The housing 34 is fixed to the joint shaft JT4 of the second robot arm 20b via the rotary joint 100 and the tool changer 102. That is, the housing 34, the rotary joint 100, and the tool changer 102 rotate integrally with the joint shaft JT4.

The housing 34 has a top plate 36a abutting on the tool changer 102, a front plate 36b hanging down from one end edge of the top plate 36a in the depth direction (in other words, the front end edge of the top plate 36a), and the other end edge ( In other words, the rear edge of the top plate 36a) hangs down from the back plate 36c. In addition, the housing 34 has a left side plate 36d that hangs down from one end edge in the width direction of the top plate 36a (in other words, the left end edge of the top plate 36a), and the other end edge in the width direction of the top plate 36a (in other words, the right end edge of the top plate 36a). The right side plate 36e, and the bottom plate 36f are arranged to cover the opening of the bottom surface of the box formed by the top plate 36a, the front plate 36b, the back plate 36c, the left plate 36d, and the right plate 36e.

As shown in FIG. 4(B), the housing 34 further has a first partition 37a that hangs down from the center of the top plate 36a in the depth direction and extends in the width direction from the left side plate 36d to the proximal side of the pinion gear 50, and along the width direction The second partition 37b extends from the right side plate 36e to the proximal side of the pinion gear 50. The internal space of the housing 34 is partitioned by the first partition 37a and the second partition 37b into the first space 38a on one side in the depth direction (in other words, the front plate 36b side of the housing 34) and the other side in the depth direction ( In other words, the second space 38b of the housing 34 on the back plate 36c side).

The pinion gear 50 extends in the height direction between the first partition 37a and the second partition 37b, and meshes with the first rack 40a and the second rack 40b. The front end portion of the pinion gear 50 (the lower end portion in FIG. 4(A)) is mounted to the bottom plate 36f of the housing 34 via a bearing 59. The rack and pinion mechanism 32 further has a base 52, which is formed integrally with the front end portion of the pinion 50 and has a larger diameter than the pinion 50. A shaft hole 54 for fixing the rotating shaft 80 is drilled through the pinion gear 50 and the base 52.

The first rack 40a can rotate around the pinion gear 50 relative to the pinion gear 50, and move in the first space 38a of the housing 34 in the width direction. In addition, the second rack 40b can rotate around the pinion gear 50 relative to the pinion gear 50, and move in the second space 38b of the housing 34 in the width direction. The first rack 40a and the second rack 40b are configured to move toward opposite sides in the width direction by rotating the pinion 50 and the pinion 50 relative to each other.

The rack and pinion mechanism 32 further has a first sensor 60a (sensor) for detecting that the first rack 40a has moved from a predetermined position in the first space 38a. The first sensor 60a has a magnet 62 fixed to the first rack 40a, and a detection unit 64 for detecting that the magnet 62 has moved. The detection unit 64 is fixed to the housing 34 and connected to the processor 94 of the robot control device 90.

The rack and pinion mechanism 32 further has a second sensor 60b (sensor) for detecting that the second rack 40b has moved from a predetermined position in the second space 38b. The second sensor 60b has a magnet 62 fixed to the second rack 40b, and a detection unit 64 for detecting that the magnet 62 has moved. The detection unit 64 is connected to the processor 94 of the robot control device 90.

The rack and pinion mechanism 32 further has a pressing mechanism 70. The pressing mechanism 70 is configured as a cylinder with the housing 34 as a cylinder and the first rack 40a as a piston. The pressing mechanism 70 inputs air into the first space 38a through a through hole 39 that is drilled through the rotary joint 100 and the right side plate 36e from an air supply source (not shown) installed outside, thereby moving the air from the first space 38a. The left side plate 36d presses the first rack 40a in the direction of the right side plate 36e (one of the moving directions).

(An example of the operation mode of Robot 10) Based on Figs. 5-7, an example of the operation state of the robot 10 will be described. Fig. 5 is a schematic cross-sectional view showing how the robot of this embodiment drills a bolt hole in a workpiece, (A) is a cross-sectional view just before the bolt is formed, (B) is a cross-sectional view when the bolt is being formed, (C) It is a cross-sectional view just after forming the bolt.

First, as shown in FIG. 5, the robot 10 pierces the bolt hole H in the workpiece W by the piercing device 88. Specifically, first, as shown in FIG. 5(A), the robot 10 changes the postures of the pair of robot arms 20 a and 20 b so that the threading device 88 is positioned above the part of the workpiece W where the bolt hole H is to be threaded.

Next, as shown in FIG. 5(B), while the robot 10 rotates the mechanical interface 28 of the first robot arm 20a through the joint axis JT4, it lowers the wrist 26 of the first robot arm 20a through the joint axis JT3. As a result, a bolt hole H is perforated in the workpiece W. Then, as shown in FIG. 5(C), the front end of the first robot arm 20a is raised by the joint axis JT3.

Next, the robot 10 is placed in a state where the gauge G is held by the holding mechanism 82. Furthermore, the robot 10 continuously inputs air of a predetermined pressure into the first space 38a of the housing 34 from the through hole 39, thereby moving the first rack 40a to a predetermined position in the first space 28a (the first space 28a reaches a predetermined position in the first space 28a). Connected to the position of the left side plate 36d). As a result, the pinion gear 50 rotates, and the second rack 40b moves to a position in the second space 38b that abuts against the right side plate 36e.

Fig. 6 is a schematic cross-sectional view showing the state of the rack in a predetermined position when the fastening device of the present embodiment performs bolt hole diagnosis, (A) is a cross-sectional view of the fastening device and its peripheral part along the height direction, (B) is a cross-sectional view along the VIB-VIB line shown in (A). Furthermore, in FIG. 6(A), in order to avoid complicated appearance, a part of the internal structure of the rack and pinion mechanism 32 is omitted and shown. Figure 7(A) and Figures 8 to 10 described below are also the same.

Then, as shown in FIG. 6(A), the robot 10 changes the postures of the pair of robot arms 20a, 20b so that the gauge G is positioned above the bolt hole H, and the second robot arm 20b is mechanically moved by the joint axis JT4. While the interface 28 rotates, the wrist 26 of the second robot arm 20b is lowered by the joint axis JT3, and the gauge G is fastened to the bolt hole H.

At this time, the torque that acts around the rotating shaft 80 by the rotational driving force of the joint shaft JT4 is referred to as the first torque. In addition, the torque that acts around the rotating shaft 80 by the pressing force of the air of the predetermined pressure described above is referred to as the second torque. The air of the predetermined pressure is adjusted so that the second torque, which is less than the first torque, works around the rotating shaft 80 in the opposite direction to the first torque, and the joint shaft JT4 is rotated and driven, thereby the fastening device 30A is provided The entire structure rotates integrally with the joint axis JT4. In this state, tighten the gauge G to the bolt hole H.

Fig. 7 is a schematic cross-sectional view showing the state of the rack after moving from a predetermined position when the bolt hole is diagnosed in the fastening device of this embodiment, (A) is a cross-section along the height direction of the fastening device and its surrounding parts Figure, (B) is a cross-sectional view along the VIIB-VIIB line shown in (A).

As shown in FIG. 7(A), when the front end of the gauge G reaches the bottom of the bolt hole H, the gauge G, the holding mechanism 82, the rotating shaft 80, and the pinion gear 50 become unable to rotate and stop. Thereby, as shown in FIG. 7(B), if the third torque greater than the second torque acts on the rotation shaft 80 via the gauge G, the first rack 40a resists the pressing force of the air of the predetermined pressure mentioned above. The pinion gear 50 rotates and moves relative to the pinion gear 50.

Specifically, while resisting the air of the predetermined pressure, the first rack 40a rotates around the pinion gear 50 relative to the pinion gear 50, from a predetermined position in the first space 28a (the first space 28a abuts on the right side). The position of the plate 36e) moves to a position where the first space 28a abuts against the left plate 36d.

7(B), as the first rack 40a moves in the manner described above, the second rack 40b rotates relative to the pinion 50 around the pinion gear 50, and abuts on the left side from the second space 38b. The position of the plate 36d moves to a position where it abuts against the right plate 36e.

When the first rack 40a starts to move in the above-described manner, the detection unit 64 of the first sensor 60a detects the movement, and sends the detection result to the robot control device 90. If the robot control device 90 detects that the first rack 40a has moved from the predetermined position in the first space 38a based on the detection result from the first detection unit 64, it starts control so that the joint axis JT4 of the second robot arm 20b The rotation stops.

(Effect) Here, it takes a predetermined time from when the detection unit 64 of the first sensor 60a detects the movement of the first rack 40a to the actual stop of the rotation of the joint shaft JT4 of the second robot arm 20b. Therefore, even after the front end of the gauge G reaches the bottom of the bolt hole H, the joint shaft JT4 of the second robot arm 20b will continue to rotate for a predetermined time even if the conventional fastening device exists. As a result, the conventional fastening device 30A may damage the bolt hole H by the gauge G that continues to rotate after reaching the bottom of the bolt hole H.

On the other hand, in this embodiment, the detection unit 64 of the first sensor 60a detects that the first rack 40a moves until the rotation of the joint shaft JT4 of the second robot arm 20b actually stops. 40a rotates around the pinion gear 50 relative to the pinion gear 50, and moves from a position in the first space 28a that abuts on the right side plate 36e to a position in the first space 28a that abuts on the left side plate 36d.

Thereby, even if the joint axis JT4 of the robot arm 20b continues to rotate for the predetermined time after the third torque is exerted around the rotation axis 80, the rotation is also caused by the movement of the first rack 40a (and the second rack 40b) It is absorbed and will not be transmitted to the rotating shaft 80 and the gauge G. As a result, the fastening device 30A of the present embodiment can suppress the risk of the gauge G being damaged and the bolt hole H.

Furthermore, when the robot control device 90 reaches a predetermined depth at the front end of the gauge G (in other words, when the mechanical interface 28 of the second robot arm 20b reaches a predetermined depth), or when the gauge G rotates by a predetermined number of revolutions (In other words, when the mechanical interface 28 is rotated by a predetermined number of revolutions), it is detected that the first rack 40a has moved from the predetermined position in the first space 38a based on the detection result of the detection portion 64 of the first sensor 60a In the case of the movement, it is diagnosed that the bolt hole H drilled by the penetration device 88 is good.

On the other hand, when the robot control device 90 reaches a predetermined depth at the front end of the gauge G, or when the gauge G does not rotate a predetermined number of revolutions, it detects according to the detection result of the detection section 64 of the first sensor 60a When the first rack 40a has moved from the predetermined position of the first space 38a, it is diagnosed that the bolt hole H drilled by the penetration device 88 is defective.

In the present embodiment, the pressing mechanism 70 is configured as a cylinder with the housing 34 as the pressing cylinder and the first rack 40a as the piston. Therefore, the first rack 40a can be pressed to the second with a simple structure. 1 A predetermined position in space 38a.

In this embodiment, the gauge G is sandwiched and held by a pair of first members 84a and 84b, so it can be combined with the gauge G with a simple structure. In addition, it can be combined with various fastening members other than the gauge G by a simple structure.

In this embodiment, it is possible to detect that the first rack 40a has moved from a predetermined position in the first space 38a by detecting that the magnet 62 fixed to the first rack 40a has moved. Therefore, it can be detected by a simple structure that the first rack 40a has moved from the predetermined position.

The robot 10 of this embodiment is equipped with the above-mentioned fastening device 30A, so the risk of damage to the bolt hole H by the gauge G can be suppressed.

(Modification) Based on the above description, various improvements or other embodiments of the present invention will be apparent to those skilled in the art. Therefore, the above description should only be interpreted as an example, and it is provided for the purpose of teaching the best mode of carrying out the present invention to a person with ordinary knowledge in the technical field. The details of the structure and/or function can be substantially changed without departing from the spirit of the present invention.

(The first modification) Fig. 8 is a schematic cross-sectional view in the height direction showing the first modification of the fastening device of the above embodiment when the bolt is fastened to the bolt hole, (A) is the cross-sectional view when the bolt is fastened, (B) The section view just after tightening the bolts. Furthermore, the fastening device 30B of this modification and the robot 10 provided with it are the same as those of the above-mentioned embodiment except that the bolt B (tightening member) is held by the holding mechanism 82 and the bolt B thus held is fastened to the bolt hole H'. The form of the fastening device 30A is the same as the robot 10 equipped with it. Therefore, the same part is marked with the same reference number, and the same description will not be repeated.

As shown in FIG. 8, the fastening device 30B of this modification can be combined with the bolt B by clamping and holding the head of the bolt B with a pair of the first members 84a, 84b of the holding mechanism 82. Furthermore, the fastening device 30B of this modification example is the same as the case where the fastening device 30A of the above-mentioned embodiment fastens the gauge G to the bolt hole H, and the bolt B can be fastened to the bolt hole H'(tightening position). In addition, the fastening device 30B of this modified example can be the same as the fastening device 30A of the above-mentioned embodiment, and it is possible to prevent the bolt B from hurting the bolt hole H'.

(Second modification) 9 is a schematic cross-sectional view in the height direction showing the second modification of the fastening device of the above embodiment when the nut is fastened to the male screw member, (A) is the cross-sectional view when the nut is fastened, (B ) Is the cross-sectional view just after tightening the nut. Furthermore, the fastening device 30C of the present modification and the robot 10 provided with the same except for holding the nut N (fastening member) by the holding mechanism 82', fastening the nut N held in this way to the male screw member M, and a pair of first The one member 84a', 84b' is the same as the fastening device 30A of the above embodiment and the robot 10 provided with it except that one of the fastening devices 30A of the above-mentioned embodiment and the first member 84a, 84b are longer. Therefore, the same part is marked with the same reference number, and the same description will not be repeated.

As shown in FIG. 9, the fastening device 30C of this modification is clamped and held by a pair of first members 84a', 84b' of the holding mechanism 82' such that the shaft hole of the nut N extends in the height direction. This can be combined with the nut N. Furthermore, the fastening device 30C of the present modification example is the same as the case where the fastening device 30A of the above-mentioned embodiment fastens the gauge G to the bolt hole H, and the nut N can be fastened to the male screw member M (fastening position). In addition, the fastening device 30C of this modified example can be the same as the fastening device 30A of the above-mentioned embodiment, and it is possible to prevent the nut N from damaging the male screw member M.

(The third modification) Fig. 10 is a schematic cross-sectional view in the height direction showing a third modification of the fastening device of the above embodiment. In addition, the fastening device 30D of this modification and the robot 10 equipped with it are the same as the fastening device 30A of the above-mentioned embodiment, and the robot 10 equipped with it except the structure of the holding mechanism 82. Therefore, the same part is marked with the same reference number, and the same description will not be repeated.

As shown in Fig. 10, the holding mechanism 82" (joining part) of the fastening device 30D of this modification makes the base end part of the gauge G'(fastening member) fit into the recess formed on the bottom surface of the holding mechanism body 83 85. This can be combined with the gauge G. The fastening device 30D can also fasten the held gauge G to the bolt hole H in this manner.

(The fourth modification) Fig. 11 is a schematic cross-sectional view in the height direction showing a fourth modification of the fastening device of the above embodiment. In addition, the fastening device 30E of this modification and the robot 10 equipped with it are the same as the fastening device 30A of the above-mentioned embodiment, and the robot 10 equipped with it except that it does not have the holding mechanism 82. Therefore, the same part is marked with the same reference number, and the same description will not be repeated.

As shown in Fig. 11, the pinion gear 50 of the fastening device 30E of this modification is formed integrally with the gauge G" (fastening member) via the base 52. As in this modification, in order to diagnose the bolt hole H, When the gauge G" is fastened to the bolt hole H and then the gauge G" is released, the fastening device 30E can also have this structure. In this case, the joint part that is combined with the fastening member is The pedestal 52.

(Fifth modification) Fig. 12 is a schematic cross-sectional view in the width direction of a rack and pinion mechanism provided in a fifth modification of the fastening device of the above embodiment. In addition, the fastening device 30F of this modification and the robot 10 equipped with it are the same as the fastening device 30A of the above-mentioned embodiment, and the robot 10 equipped with it except the structure of a pushing mechanism. Therefore, the same part is marked with the same reference number, and the same description will not be repeated.

As shown in FIG. 12, the fastening device 30F of this modification includes a rack and pinion mechanism 32' having a spring member 70' as a pressing mechanism. One end of the spring member 70' is installed on the inner wall of the left side plate 36d, and the other end is installed on the part of the first rack 40a opposite to the left side plate 36d, thereby moving along the left side plate 36d in the first space 38a. The first rack 40a is pressed in the direction of the right side plate 36e. The fastening device 30F uses the spring member 70' of this aspect to push the first rack 40a to a predetermined position. The rack and pinion mechanism 32' of this structure can also obtain the same effect as the fastening device 30A of the above-mentioned embodiment.

(The sixth modification) 13 is a schematic cross-sectional view in the width direction of the rack and pinion mechanism provided in the fifth modification of the fastening device of the above embodiment. Furthermore, the fastening device 30G of the present modification and the robot 10 equipped with the same, except for the structure of the housing 34', and the sensor 60 that does not have the second rack 40b and the second rack 40b, The fastening device 30A of the above-mentioned embodiment and the robot 10 equipped with it are the same. Therefore, the same part is marked with the same reference number, and the same description will not be repeated.

As shown in FIG. 13, the rack and pinion mechanism 32" of the fastening device 30G of this modification does not have the second rack 40b and the sensor 60 for the second rack 40b. Accompanying this, In this modification, the housing 34' does not have the first partition 37a and the second partition 37b, and therefore does not have the second space 38b for arranging the second rack 40b. The rack and pinion of this structure The mechanism 32" can also obtain the same effect as the fastening device 30A of the above-mentioned embodiment.

(The seventh modification) Fig. 14 is a schematic view showing a seventh modification of the fastening device of the above embodiment. Fig. 15 is a block diagram showing a control system of a robot provided with the seventh modification. In addition, the fastening device 30H and the robot 10 equipped with it of this modification are the same as the fastening device 30A and the robot 10 equipped with it of the said embodiment except the servomotor 98. Therefore, the same part is marked with the same reference number, and the same description will not be repeated.

In the above embodiment, the case where the drive shaft of the fastening device 30A is configured as the joint shaft JT4 (wrist shaft) of the second robot arm 20b has been described. On the other hand, in this modification, the drive shaft of the fastening device 30H is configured as an external shaft 86 provided in the fastening device 30H. The tightening device 30H servo-controls the operation of the tightening device 30H by a servo motor 98 (second servo motor) provided on the outer shaft 86 in order to rotationally drive the outer shaft 86. The fastening device 30H of this structure can also obtain the same effects as the fastening device 30A of the above-mentioned embodiment.

(Other modifications) In the above-mentioned embodiment and its modification examples, the case where the fastening part to be combined with the fastening member is configured as the holding mechanism 82, 82' or the pedestal 52 has been described. However, it is not limited to this case, and the fastening portion may be configured as an adsorption mechanism that is coupled to the fastening member by sucking the fastening member, for example, or may be configured in other ways to be combined with the fastening member.

In the above-mentioned embodiment and its modification, the case where the base portion is configured as the housing 34, 34' has been described. However, it is not limited to this case. For example, when the pressing mechanism is configured as a spring member, the base may be configured as a plate-shaped member that does not surround the first rack 40a and the pinion 50. In this case, the first rack 40a is installed in a manner to be slidable on the above-mentioned plate-shaped member.

In the above-mentioned embodiment and its modification, the case where the sensor has a structure having the magnet 62 and the detection portion 64 has been described. However, it is not limited to this situation, and the sensor may also have a structure with a light projector and a light receiver for receiving light emitted from the light projector. In addition, the sensor can detect that the first rack 40a has moved from a predetermined position according to the shielding state of the light received by the light receiver. Alternatively, the sensor may have a structure other than the above as long as it can detect that the first rack 40a has moved from a predetermined position.

In the above-mentioned embodiment and its modification examples, the case where the housing 34 (base portion) is fixed to the joint shaft JT4 (drive shaft) and the pinion gear 50 is fixed to the rotation shaft 80 has been described. However, it is not limited to this case, and the pinion gear 50 may be fixed to the joint shaft JT4 and the housing 34 may be fixed to the rotation shaft 80.

In the above-mentioned embodiment and its modification examples, the case where the rotation axes of the respective base ends of the robot arms 20a and 20b are located on the same straight line has been described. However, it is not limited to this case, and the rotation axis of the respective base ends of the robot arms 20a and 20b may not be located on the same straight line. In addition, in the above-mentioned embodiment and its modification examples, the case where one robot 10 is provided with the robot arms 20a and 20b has been described. However, it is not limited to this case. For example, the first robot may include the robot arm 20a, and the second robot provided differently from the above-mentioned first robot may include the robot arm 20b.

In the above-mentioned embodiment and its modification examples, the case where the robot 10 has the structure shown in FIG. 1 has been described. However, it is not limited to this case, and the robot of the present invention may be configured as, for example, a vertical articulated robot, or may be configured as a horizontal articulated robot. Alternatively, the robot of the present invention may be configured as a polar coordinate robot, may be configured as a cylindrical coordinate robot, may be configured as a right-angle coordinate robot, or may be configured as another robot.

In the above-mentioned embodiment and its modification, the magnet 62 is fixed to the first rack 40a and moves together with the first rack 40a, whereby the detection unit 64 fixed to the housing 34 detects that the magnet 62 has moved relatively. The situation of the matter was explained. However, it is not limited to this case, and the detection portion 64 may be fixed to the first rack 40a and move together with the first rack 40a, whereby the detection portion 64 detects that the magnet 62 fixed to the housing 34 has faced each other. Move a thing.

(Summarize) The fastening device of the present invention, which is used to fasten the fastening member to the fastening position by using the rotational driving force of the drive shaft to rotate it, is characterized by comprising: a rack and pinion mechanism; and A rotating shaft, which is mounted on the drive shaft via the rack and pinion mechanism, has a coupling portion coupled with the fastening member at its front end, and the rack and pinion mechanism has: a base; a rack with The pinion is movably installed on the base; a pinion is rotatably arranged on the base and engages with the rack; a pushing mechanism that pushes the rack to one of the moving directions; and a sensor , Which is used to detect that the rack has moved from the predetermined position of the base, one of the base and the pinion is fixed to the drive shaft, and the other of the base and the pinion is fixed to the Rotation axis.

The torque that acts around the above-mentioned rotating shaft by the rotational driving force of the drive shaft is referred to as the first torque. In addition, the torque that acts around the above-mentioned rotating shaft by the pressing force of the pressing mechanism is referred to as the second torque. The drive shaft is rotationally driven with a second torque that is less than the first torque and works around the rotation shaft in a direction opposite to the first torque, whereby at least the base, rack, pinion, and rotation shaft are connected with each other. The above-mentioned drive shaft rotates integrally. In this state, if a third torque greater than the second torque acts around the rotation shaft via the fastening member, the rack resists the pressing force of the pressing mechanism and rotates around the pinion gear relative to the pinion gear. And move. As a result, after the third torque is exerted around the rotation shaft, even if the drive shaft continues to rotate for a predetermined time, the rotation is absorbed by the movement of the rack, so it will not be transmitted to the rotation shaft and the fastening member . As a result, the fastening device of the present embodiment can suppress the possibility of damage to the fastening member and the fastening position.

The pressing mechanism may be configured as a cylinder having the base as a cylinder and the rack as a piston.

According to the above structure, the rack can be pushed to a predetermined position with a simple structure.

For example, the above-mentioned pressing mechanism may be configured as a spring member.

For example, the coupling portion may have a pair of first members, and the pair of first members sandwiches and holds the fastening member, thereby being combined with the fastening member.

The sensor may include a magnet and a detection unit for detecting that the magnet has moved relatively, and either the magnet or the detection unit may be fixed to the rack.

According to the above structure, it is possible to detect that the rack has moved from a predetermined position with a simple structure.

The robot of the present invention is characterized by comprising: a fastening device having any of the above-mentioned configurations; a robot arm having the fastening device provided at the front end thereof and having at least one joint axis; and a robot control device for controlling the The actions of the fastening device and the robot arm are servo-controlled; the drive shaft is configured as a wrist axis included in the at least one joint axis or an external axis provided in the fastening device, and the robot control device is configured to A first servo motor that rotationally drives each of the at least one joint shaft and each of the at least one joint shaft servo controls the motion of the robot arm, and the first servo motor provided on the wrist shaft in order to rotationally drive the wrist shaft A servo motor, or a second servo motor provided on the external shaft for rotationally driving the external shaft, servo-controls the operation of the fastening device.

According to the above-mentioned structure, the robot of the present invention is provided with the fastening device having the above-mentioned structure. Therefore, it is possible to suppress the possibility of damage to the fastening member and the fastening position.

10: Robot 12: Abutment 14: Base shaft 20a: No. 1 robotic arm 20b: Arm #2 22: The first link 24: 2nd link 26: Wrist 28: Mechanical interface 30A～30H: Fastening device 32, 32', 32": rack and pinion mechanism 34, 34': shell 36a: top plate 36b: front panel 36c: backplane 36d: left side panel 36e: right side panel 36f: bottom plate 37a: first partition 37b: Second partition 38a: first space 38b: second space 39: Through hole 40a: 1st rack 40b: 2nd rack 50: pinion 52: Pedestal 54: Shaft hole 59: Bearing 60: Sensor 62: Magnet 64: Detection Department 70: Pushing mechanism 70': Spring member 80: Rotation axis 82, 82', 82": holding mechanism 83: Keep the body of the mechanism 84a, 84b, 84a', 84b': the first member 85: recess 86: External shaft 88: Wearing device 90: Robot control device 92: memory 94: processor 96a～96h: Servo motor (1st servo motor) 98: Servo Motor (Second Servo Motor) 100: Rotary joint 102: Tool changer B: Bolt G, G',: gauge H: Bolt hole JT1～JT4: Joint axis M: Male threaded member N: Nut S: Mounting table W: Workpiece

Fig. 1 is a schematic front view showing the overall configuration of a robot equipped with a fastening device according to an embodiment of the present invention. Fig. 2 is a block diagram showing a control system of a robot equipped with a fastening device according to an embodiment of the present invention. [Fig. 3] is a schematic view showing the fastening device of the embodiment of the present invention, (A) is a diagram of the fastening device not holding the fastening member, (B) is the fastening device holding the fastening member picture. [Figure 4] A cross-sectional view of the rack and pinion mechanism of the fastening device of the embodiment of the present invention, (A) is a cross-sectional view along the height direction, (B) is along the IVB shown in (A) -Sectional view of IVB line. [Figure 5] is a schematic cross-sectional view showing how the robot according to the embodiment of the present invention drills a bolt hole in a workpiece, (A) is a cross-sectional view just before the bolt is formed, and (B) is a cross-sectional view when the bolt is being formed , (C) is the sectional view just after forming the bolt. [Fig. 6] is a schematic cross-sectional view showing the state of the rack at a predetermined position when the fastening device of the embodiment of the present invention performs bolt hole diagnosis, (A) is the height direction of the fastening device and its surrounding parts The cross-sectional view of (B) is the cross-sectional view along the VIB-VIB line shown in (A). [Figure 7] is a schematic cross-sectional view showing the state of the rack after moving from a predetermined position when the fastening device of the embodiment of the present invention performs bolt hole diagnosis, (A) is the edge of the fastening device and its peripheral part The cross-sectional view in the height direction, (B) is the cross-sectional view along the VIIB-VIIB line shown in (A). [Fig. 8] is a schematic cross-sectional view in the height direction showing the first modification of the fastening device of the embodiment of the present invention when the bolt is fastened to the bolt hole, (A) is the cross-sectional view when the bolt is fastened , (B) is the cross-sectional view just after tightening the bolts. [Fig. 9] A schematic cross-sectional view in the height direction showing the second modification of the fastening device of the embodiment of the present invention when the nut is fastened to the male screw member, (A) is the cross-section when the nut is fastened Figure, (B) is a cross-sectional view just after tightening the nut. Fig. 10 is a schematic cross-sectional view in the height direction showing a third modification of the fastening device of the embodiment of the present invention. Fig. 11 is a schematic cross-sectional view in the height direction showing a fourth modification of the fastening device of the embodiment of the present invention. Fig. 12 is a schematic cross-sectional view in the width direction of the rack and pinion mechanism included in the fifth modification of the fastening device of the embodiment of the present invention. Fig. 13 is a schematic cross-sectional view in the width direction of the rack and pinion mechanism included in the sixth modification of the fastening device of the embodiment of the present invention. Fig. 14 is a schematic diagram showing a seventh modification of the fastening device of the embodiment of the present invention. Fig. 15 is a block diagram showing a control system of a robot equipped with a seventh modification of the fastening device of the embodiment of the present invention.

10: Robot

12: Abutment

20a: No. 1 robotic arm

20b: Arm #2

22: The first link

24: 2nd link

26: Wrist

28: Mechanical interface

30A: Fastening device

32: rack and pinion mechanism

82: Keep the organization

88: Wearing device

90: Robot control device

G: gauge

JT1~JT4: joint axis

S: Mounting table

W: Workpiece

Claims (6)

A fastening device, which is used to fasten a fastening member at a fastening position by rotating it by using the rotational driving force of a drive shaft, characterized by comprising: a rack and pinion mechanism; and a rotating shaft , It is mounted on the drive shaft via the rack and pinion mechanism, and has a coupling part that is coupled with the fastening member at its front end; the rack and pinion mechanism has: a base; a rack, which is movable A pinion, which is rotatably arranged on the base and engages with the rack; a pressing mechanism, which pushes the rack to one of the moving directions; and a sensor, which is used In detecting that the rack has moved from a predetermined position of the base, one of the base and the pinion is fixed to the drive shaft, and the other of the base and the pinion is fixed to the rotation shaft. The fastening device according to claim 1, wherein the pressing mechanism is configured as a cylinder having the base as a pressure cylinder and the rack as a piston. The fastening device according to claim 1, wherein the pressing mechanism is configured as a spring member. The fastening device according to claim 1, wherein the coupling portion has a pair of first members, and the pair of first members sandwiches and holds the fastening member, thereby being coupled to the fastening member. The fastening device according to any one of claims 1 to 4, wherein the sensor has a magnet and a detection unit for detecting that the magnet has moved relatively, and any one of the magnet and the detection unit is fixed于The above rack. A robot, characterized in that it is provided with: a fastening device according to any one of claims 1 to 5; A robotic arm is provided with the fastening device at its front end and has at least one joint axis; and a robot control device for servo-controlling the actions of the fastening device and the robotic arm; the drive shaft is used as the at least A wrist shaft included in one joint shaft, or an external shaft provided in the fastening device, and the robot control device is constituted by a first servo motor provided on the at least one joint shaft in order to rotationally drive the at least one joint shaft Servo controls the action of the robot arm. The first servo motor provided on the wrist shaft for rotationally driving the wrist shaft, or the second servo motor provided on the external shaft for rotationally driving the external shaft is servo-controlled by the Action of the fastening device.

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