JP3648875B2 - Rotating shaft stopper mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of a rotating shaft of a device used for work handling, and more particularly to a rotating shaft stopper mechanism.
[0002]
[Prior art]
Conventionally, various robots have been introduced in order to automatically perform work handling operations such as work transfer and alignment. In the case of a SCARA robot, since the angle of the tip end that grips the workpiece changes with XY movement, a rotation axis for correction is necessary regardless of whether the workpiece needs to be rotated. In the case of a direct robot, the angle of the tip does not change, but a rotation axis is still necessary for the purpose of rotating the workpiece. For example, an orthogonal robot such as a 4-axis robot includes an R-axis (rotary axis) module in addition to an X-axis module, a Y-axis module, and a Z-axis module, and 3 by a combination of X, Y, and Z linear motions. Generally, a robot hand that grips a workpiece is attached to a rotating shaft having a dimensional work range so that the workpiece can be handled freely.
[0003]
Such a rotary shaft is usually formed by incorporating a speed reducer in a servo motor, and rotates the forward and reverse directions to freely align the workpieces in an arbitrary direction. Therefore, the robot hand is provided with electric wiring, air piping, and the like, and the rotation angle of the rotation shaft needs to be restricted to a certain range so that they do not get entangled or interfere with each other. Conventional rotation regulation of the rotation shaft is performed by a rotation shaft stopper mechanism as shown in FIG. 7, for example. This includes a damper 3 that is attached to the rotary shaft 2 of the rotary motor 1 and that can freely move along the inner periphery of the cylindrical housing, and a stopper 4 that is fixedly attached to the inner peripheral surface of the housing. The damper 3 is moved between the position A and the position B in FIG. 7 to regulate the clockwise and counterclockwise rotation angles.
[0004]
[Problems to be solved by the invention]
However, in the conventional rotary shaft stopper mechanism, the rotation angle of the rotary shaft 2 restricted by the stopper 4 is only about 300 degrees. However, in order to align irregularly scattered workpieces freely in an arbitrary direction, there is a problem that the rotating shaft must be able to rotate forward and backward within a range of 360 degrees or more.
[0005]
Therefore, the present invention has been made paying attention to such a conventional problem, and is restricted to a finite rotation so that the rotation axis can be rotated in the forward and reverse directions within a range of 360 degrees or more and the wiring or the like is not entangled. It aims at providing a rotating shaft stopper mechanism.
[0006]
[Means for Solving the Problems]
In order to achieve this object, the invention of claim 1 is a rotating shaft having a dog that rotates integrally with the rotating shaft with a constant rotating radius around a rotating shaft that rotates in both the clockwise and counterclockwise directions. In the stopper mechanism, a first stopper that restricts the clockwise rotation range of the rotation shaft is provided at a position that does not interfere with the dog, and a second stopper that restricts the counterclockwise rotation range of the rotation shaft. Is provided at a position where it does not interfere with the dog, and a leaf spring having a free end at an intermediate position between the first stopper and the second stopper is provided at a position where it interferes with the dog. is there.
According to a second aspect of the present invention, there is provided a dog that rotates integrally with the rotating shaft with a constant rotation radius around a rotating shaft that rotates in both a clockwise direction and a counterclockwise direction, and a clockwise rotation range of the rotating shaft. A rotary shaft stopper mechanism having a first stopper for regulating the rotation and a second stopper for regulating a counterclockwise rotation range of the rotary shaft, wherein the first stopper and the second stopper are connected to the dog. A coil spring which is provided at a position where it does not interfere with the dog and which swings by interfering with the dog between the first stopper and the second stopper and which presses the side surface of the rocking plate Are arranged on both sides of the swinging plate so as to be located inside the rotation trajectory of the dog .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 show a first embodiment. First, the configuration will be described. A rotary motor 1 is built in a cylindrical housing 5. The rotary shaft 2 is supported by the housing 5 so as to be rotatable forward and backward, and the shaft tip 2 a projects into the housing space above the rotary motor 1. The dog 6 is fixed to the shaft tip 2a so as to be rotatable integrally with the rotating shaft 2. The dog 6 is an iron block body, and a urethane rubber coating functioning as a damper is attached to the surface thereof, and is fixed to the rotary shaft 2 via a dog mounting member 10.
[0008]
A leaf spring 7 is disposed as an elastic body in the space above the shaft tip 2a. The leaf spring 7 is longer than the radius of the cylindrical housing 5, and one end thereof is fixed to the housing 5 with a bolt B <b> 1 via a fixing block member 8 at an intermediate position between the rotating shaft 2 and the inner surface of the housing 5. The other end of the leaf spring 7 is a free end 7a, and extends beyond the rotating shaft 2 to near the inner surface of the opposite housing. Therefore, the free end 7a of the leaf spring 7 can swing within a certain range with the fixing block member 8 as a fulcrum, but when the leaf spring 7 is not biased, the free end 7a is neutral as shown in FIG. To be held in position. A position detection plate 9 is attached at a position somewhat closer to the fixed end from the free end 7a.
[0009]
When the free end 7a of the leaf spring 7 held in the neutral position is sandwiched between the CW stopper 11 that collides when the free end 7a is displaced clockwise, and the free end 7a is displaced counterclockwise CCW stoppers 12 that collide with each other are fixedly installed on the housing 5. These stoppers 11 and 12 are disposed outside the rotation radius of the dog 6 so as not to interfere with the dog 6 that rotates integrally with the rotary shaft 2. That is, in the first embodiment, the dog 6 is configured to interfere with both the stoppers 11 and 12 only through the leaf spring 7. Therefore, the leaf spring 7 located between the stoppers 11 and 12 is interposed between the dog 6 and the stoppers 11 and 12 so that the dog 6 and the stopper 11 (12) are in accordance with the rotation direction of the rotary shaft 2. It functions as an interference member that causes interference.
[0010]
A proximity sensor 13 as a CW sensor is disposed on the inner diameter side in the vicinity of the CW stopper 11, and a proximity sensor 14 as a CCW sensor is secured to the housing 5 on the inner diameter side in the vicinity of the CCW stopper 12. When the free end 7a of the leaf spring 7 collides with the stopper 11 or 12, the position detection plate 9 described above is set so as to block the optical path of the CW sensor 13 or CCW sensor 14 and generate a sensor signal, Thereby, the rotation direction of the rotating shaft 2 can be recognized.
[0011]
In FIG. 1, 15 is a wiring connector for the proximity sensors 13 and 14, and 16 is a motor wiring.
Next, the operation will be described.
[0012]
Assume that the dog 6 and the leaf spring 7 are in the neutral position shown in FIG. When the rotary motor 1 is operated counterclockwise, the dog 6 rotates counterclockwise together with the rotary shaft 2 while pushing the leaf spring 7 against the elastic force. As shown in FIG. 3, when the dog 6 reaches the position A, the free end 7 a of the leaf spring 7 collides with the CCW stopper 12. At the same time, the position detection plate 9 of the leaf spring 7 comes directly under the CCW sensor 14. The CCW sensor 14 detects this and outputs a sensor signal for counterclockwise rotation.
[0013]
Next, when the rotary motor 1 is operated in the clockwise direction from the position of FIG. 3, the rotating shaft 2 and the dog 6 are rotated in the clockwise direction. Then, the leaf spring 7 returns to the neutral position in FIG. 2 by its own elastic restoring force, and the sensor signal of the CCW sensor 14 is turned off. The dog 6 continues to rotate clockwise through B to C, and when it rotates approximately 360 degrees, it contacts the leaf spring 7 in the neutral position from the opposite direction. Thereafter, the dog 6 further rotates clockwise together with the rotary shaft 2 while pushing the leaf spring 7. As shown in FIG. 4, when the dog 6 reaches the position D, the free end 7 a of the leaf spring 7 collides with the CW stopper 11. At the same time, the position detection plate 9 of the leaf spring 7 is directly below the CW sensor 13, and the CW sensor 13 detects this and outputs a sensor signal for clockwise rotation.
[0014]
If the dog 6 rotates 360 degrees or more in the counterclockwise direction from the position D through C and B, the position reaches the position A, and the CCW sensor 14 outputs a signal of counterclockwise rotation again.
[0015]
Thus, according to the first embodiment, with a simple rotating shaft stopper mechanism that uses the elasticity of the spring, the rotating shaft can be easily rotated in the forward and reverse directions within a finite rotating angle range exceeding 360 degrees, and the wiring or the like can be used. The effect that it can prevent the entanglement of is obtained.
[0016]
FIG. 5 shows a second embodiment.
In this embodiment, a coil spring 20 is used in place of the leaf spring 7 as an elastic body. That is, the stopper 11 for stopping the rotation of the rotating shaft 2 of the rotary motor 1 in the clockwise direction and the stopper 12 for stopping the rotation in the counterclockwise direction are connected by the shaft 21, and the slider 22 is slidable on the shaft 21. The rotary shaft stopper mechanism is configured by passing two coil springs 20 on both sides of the slider 22. The dog 6 can contact the side surface of the slider 22 and presses the coil spring 20 via the slider 22. That is, in this second embodiment, the dog 6 is configured to interfere with both stoppers 11 and 12 via the slider 22 and the coil spring 20, and the coil spring 20 and the slider 22 are connected to the dog 6. It functions as an interference member that causes the stopper 11 (12) to interfere with the rotation direction of the rotary shaft 2.
[0017]
In the neutral position shown in FIG. 5, the elastic forces of the two coil springs 20 and 20 are balanced, and the slider 22 is just in the middle between the stoppers 11 and 12. From this position, the dog 6 comes into contact with the side surface on the opposite side of the slider 22 when the dog 6 is rotated approximately 360 degrees clockwise along with the rotation of the rotary shaft 2. Thereafter, the dog 6 continues to rotate while pressing the slider 22 and compressing one coil spring 20. At the same time, when the rotation is 360 degrees or more, it is regulated by the stopper 11 and stops. At the same time, the slider 22 is directly below a CW sensor (not shown), and the CW sensor detects this and outputs a sensor signal for clockwise rotation.
[0018]
When the dog 6 rotates counterclockwise from the clockwise sensor signal output position, the slider 22 returns to the neutral position by the elastic restoring force of the coil spring 20, and the sensor signal of the CW sensor is turned off. When the dog 6 continues to rotate counterclockwise and rotates nearly 360 degrees, the dog 6 contacts the slider 22 in the neutral position from the opposite direction. Thereafter, the dog 6 further rotates counterclockwise while compressing the other coil spring 20. Then, when the rotation is 360 degrees or more, the slider 12 is controlled by the stopper 12 and stops. At the same time, the slider 22 is directly below a CCW sensor (not shown), and the CCW sensor detects this and outputs a sensor signal for counterclockwise rotation.
[0019]
Thus, the second embodiment can provide the same effects as those of the first embodiment.
In the second embodiment, the member against which the dog 6 abuts is not the leaf spring 7 but the block material slider 22 and collides with the stoppers 11 and 12 via the slider 22 and the compressed coil spring 20. Therefore, there is an advantage that the rigidity of the rotary shaft stopper mechanism is improved and vibration due to vibration is reduced.
[0020]
FIG. 6 shows a third embodiment.
In this embodiment, a rocking plate 30 is disposed between the stoppers 11 and 12, and the rocking plate 30 is elastically pressed by two coil springs 20 arranged on opposite sides of the rocking plate 30. The rotary shaft stopper mechanism is configured to be held at the neutral position. The oscillating plate 30 functions as an interference member that oscillates at the other end, which is a free end, around the oscillating shaft 30a at one end and interferes with the stoppers 11 and 12.
[0021]
When the dog 6 rotates 360 degrees or more clockwise or counterclockwise, the swinging plate 30 collides with the stopper 11 or 12 and stops, and at the same time, the CW sensor or CCW sensor (not shown) is directly below the CW sensor or CCW sensor. Detects this and outputs a sensor signal of clockwise rotation or counterclockwise rotation.
[0022]
Thus, the third embodiment can provide the same effects as those of the first embodiment. Also in this embodiment, the member that collides with the dog 6 and the stoppers 11 and 12 is the swing plate 30 instead of the leaf spring 7, so that there is an advantage that the rigidity of the rotary shaft stopper mechanism is improved and vibration due to vibration is reduced.
[0023]
In the description of each of the above embodiments, an example in which a proximity sensor is used to output a sensor signal for clockwise rotation or counterclockwise rotation has been shown. However, the present invention is not limited to this, and other known contact-type sensors. Etc. are also available. Further, a signal may be output by detecting that a force is applied to the stopper from the interference member.
[0024]
【The invention's effect】
As described above, the rotating shaft stopper mechanism according to the present invention uses the elasticity of the elastic body to perform forward and reverse rotation of the rotating shaft in a range of a finite rotation angle exceeding 360 degrees, which has been difficult in the past. It can be easily performed with a simple mechanism, and the effect of preventing entanglement of wiring and the like can be achieved.
[Brief description of the drawings]
FIG. 1 is a side view of a first embodiment of a rotary shaft stopper mechanism of the present invention.
FIG. 2 is a plan view taken along the line II-II in FIG.
FIG. 3 is a plan view for explaining the operation.
FIG. 4 is a plan view for explaining the operation.
FIG. 5 is a schematic plan view of a second embodiment of the present invention.
FIG. 6 is a schematic plan view of a third embodiment of the present invention.
FIG. 7 is a schematic plan view of a conventional rotary shaft stopper mechanism.
[Explanation of symbols]
2 Rotating shaft 6 Dog 7 Elastic body (interference member)
11 Stopper 12 Stopper 13 Sensor (Rotation direction detection means)
14 Sensor (Rotation direction detection means)
20 Elastic body (interference member)
22 Slider (interference member)
30 Swing plate (interference member)

Claims (2)

In a rotating shaft stopper mechanism having a dog that rotates integrally with the rotating shaft with a constant rotating radius around a rotating shaft that rotates in both the clockwise and counterclockwise directions,
A first stopper for restricting the clockwise rotation range of the rotating shaft is provided at a position not interfering with the dog, and a second stopper for restricting the counterclockwise rotating range of the rotating shaft is provided on the dog. A rotary shaft stopper mechanism provided with a leaf spring provided at a position where it does not interfere and having a free end at an intermediate position between the first stopper and the second stopper at a position where it interferes with the dog. A dog that rotates integrally with the rotary shaft with a constant radius of rotation about a rotary shaft that rotates in both the clockwise and counterclockwise directions; and a first stopper that regulates a clockwise rotation range of the rotary shaft And a rotary shaft stopper mechanism having a second stopper for regulating a counterclockwise rotation range of the rotary shaft,
The first stopper and the second stopper are provided at positions that do not interfere with the dog, and a swinging plate that swings while interfering with the dog is interposed between the first stopper and the second stopper. A rotating shaft stopper mechanism, characterized in that a coil spring that is provided and presses a side surface of the swing plate is disposed on both sides of the swing plate so as to be positioned inside a rotation locus of the dog .

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