JPS644150B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotational direction teaching mechanism for a rotating shaft that supports and rotates a processing tool.

Generally, a processing tool such as a torch for welding or fusing is supported on a rotating shaft, and the rotating shaft is rotated appropriately within a range where the maximum rotation angle of the rotating shaft is, for example, 360 + θ degrees, and a support mechanism is used to rotate the rotating shaft. Arbitrary processing is performed by appropriately controlling the position in the X, Y, and Z axis directions. In this case, the processing is performed by a so-called industrial robot using a computer, and as shown in FIG. It is rotated based on the input data within. By the way, how many degrees has the current position of the rotating shaft rotated in either the clockwise or counterclockwise direction with respect to the reference point A?
Since it uses a computer, it can be easily recognized depending on how the program is created, but
Unless special measures are taken, the current position of the rotating shaft will not be recognized even if the system is restarted after a power outage or after the main power is disconnected. Furthermore, in FIG. 2, if a detector such as an air sensor or a photo sensor is provided, and the rotating shaft is located at the same position between BC⌒, the detector will The same detection signal is generated. Therefore, it is impossible to determine in which direction the rotary shaft should be rotated in order to return the rotary shaft to the reference point in this state. Of course, if you create a program to recognize in which direction the rotating shaft has arrived at its current position from the reference point, you can determine the direction of rotation to return the rotating shaft, but as mentioned above, after a power outage or When the main power is turned off and then restarted, the above determination becomes impossible.

That is, in Fig. 2, when the rotating shaft rotates counterclockwise from reference point A and is located at point D between BC⌒, when the rotating shaft returns, the rotating shaft rotates further counterclockwise by mistake. When the rotary shaft moves and reaches the reference point A, the rotating shaft is rotated 360 degrees more than the actual reference position. When the rotating shaft rotates using the position rotated one rotation as the reference point in this way, various cables connected to the rotating shaft from the outside may become wrapped around the rotating shaft, causing damage to the various cables and causing them to be cut. Moreover, if various cables are wrapped around the rotating shaft, the rotation of the rotating shaft is obstructed, and therefore it is not suitable for industrial robots that require high-precision machining.

SUMMARY OF THE INVENTION An object of the present invention is to provide a mechanism for teaching the rotational direction of a rotary shaft when returning to a machine when the rotary shafts supporting the processing tools are rotated so as to overlap with each other during machining.

The present invention will be explained in detail below with reference to the illustrated embodiments.

In FIGS. 3 and 4, reference numeral 1 denotes a rotating shaft rotated by a drive machine (not shown), which supports a processing tool such as a welding torch T. 2 is a floating dog having a suitable arc-shaped protrusion 201, and is rotatably supported with respect to the rotating shaft 1 via a thrust ring 3 and a bush 4. Reference numeral 5 denotes a dog having a substantially semicircular arc-shaped protrusion 501 and is supported integrally with the rotating shaft 1 . 6 is a spring support member integrally supported by the dog 5, 7, 7 is a spring support member installed upright on the floating dog 2, 8, 8
are, for example, coil springs supported by spring support members 6 and 7, and are configured so that when the rotating shaft 1 rotates, the floating dog 2 rotates substantially synchronously. Reference numeral 9 denotes a stopper which is used to stop the floating dog 2 from projecting from the surface 202 when the floating dog 2 rotates by a predetermined amount clockwise or counterclockwise, respectively.
Or 203 is configured to abut against the stopper 9. 11 to 13 are respective detectors, for example, photoelectric detectors are used respectively, the detectors 11 and 12 correspond to the arcuate protrusion of the floating dog, and the detector 13 corresponds to the approximately semicircular arcuate protrusion of the dog 5. It is arranged to correspond.

In the above configuration, the state of the dog 5 and the floating dog 2 when the rotating shaft 1 is at the reference position is, for example, the state shown in FIG. 3, and from this state the rotating shaft 1 is moved clockwise by an angle α When the rotating shaft 1 rotates, the spring support member 6 integrally formed with the rotating shaft 1 also rotates, and as a result, the spring 802 is pulled, so that the floating dog 2 also rotates. That is, as shown in FIG. 5, when the rotation shaft 1 rotates, the floating dog 2 rotates substantially synchronously. After this, if the rotating shaft 1 further rotates clockwise, the protruding surface 202 of the floating dog 2 will come into contact with the stopper 9, and after this, only the rotating shaft 1, dog 5, and spring support member 6 will rotate clockwise. Rotate.
FIG. 6 shows a state in which the rotating shaft 1 has further rotated a certain angle clockwise after the floating dog 2 has come into contact with the stopper 9. When the rotating shaft 1 rotates counterclockwise from the state shown in FIG.
The floating dog 2 rotates around the rotation axis 1 up to a certain angle.
After the rotation shaft 1, the dog 5, and the spring support member 6 rotate in the counterclockwise direction, only the rotation shaft 1, the dog 5, and the spring support member 6 rotate in the counterclockwise direction.

Next, the detection states of the detectors 11 to 13 will be explained. When the rotating shaft 1 is at the reference position as shown in FIG. 3, the detectors 11 to 13 are in the first detection state where light is not blocked. It is in.
For example, if the rotating shaft 1 rotates clockwise from this state, the detector 13 enters a second detection state in which light is blocked by the protrusion of the dog 5. After that, when the rotating shaft 1 further rotates clockwise and the floating dog 2 approaches or contacts the stopper 9, the detector 12 enters the second detection state where the light is blocked, and after this, the rotating shaft 1 further rotates clockwise, the detector 12 maintains the second detection state. On the other hand, when the rotating shaft 1 rotates counterclockwise from the state shown in FIG. 3, if the rotating shaft 1 rotates by a predetermined angle or more, the detector 11 enters the second detection state where the light is blocked. . In Figure 2, the rotation axis 1
When the detector 12 rotates clockwise from point A, the detector 12 rotates from point B to point C.
becomes the second detection state and when the rotating shaft 1 is to be returned, the rotating shaft 1 is rotated counterclockwise by a drive machine (not shown). Also, when the rotating shaft 1 rotates counterclockwise from point A, the detector 11 enters the second detection state when it rotates from point C to the point B side, and in this case, the above is different. Conversely, the rotating shaft 1 is rotated clockwise. In addition, in FIG. 2, when the rotating shaft 1 is located in a range where it does not wrap, that is, between AC⌒ or AB⌒, the detector 13 or two or more appropriate detectors detects this, and the rotating shaft 1 is accurately returned. can be set.

As mentioned above, the area where the rotation axis 1 wraps, that is,
BC⌒When the detector 11 or 12 is located between
The rotational axis is returned accurately. Moreover, even if the power is interrupted or the main power supply is accidentally turned off before the rotation axis is reset when the rotation axis is located between BC⌒, the detector 11 or 12 detects that the rotation axis is Since the direction of return rotation is clear, the rotating shaft does not rotate to a position that is an extra 360 degrees relative to the reference position as in the conventional case.

In the above description, if the stopper that comes into contact with the floating dog is configured for left rotation and right rotation separately, and the position in the circumferential direction can be adjusted, the detection angle of the floating dog can be adjusted appropriately. I can do it. Furthermore, it is preferable to fix the detector and make the floating dog rotatable because the connecting line of the detector will be in a fixed state, but it is preferable to make the detector movable and to make the operating member that operates the detector fixed. I can do it.

Further, it is preferable that the detector be a photoelectric type because it is compact, but any detector that uses a magnetic field or pressure can be used. Further, the spring support member 6 can also be supported on the rotating shaft 1.
In this case, if the base of the spring support member 6 is clamped to the rotating shaft using a split clamp, the relative position of the floating dog 2 to the rotating shaft can be freely adjusted.

As described above, according to the present invention, the structure is simple and the direction of return rotation of the rotary shaft is clearly determined mechanically, so there is no effect even if the main power supply is disconnected during operation. Moreover, because the rotational axis returns accurately, the rotational axis is
The position rotated by an extra rotation is not used as the reference position, so the conventional problem of various cables being damaged and cut does not occur, and the various cables are not connected to the rotation axis more than necessary. Since it does not wrap around objects, it is more useful if it is used in industrial robots equipped with rotating devices that perform high-precision machining.

[Brief explanation of drawings]

FIG. 1 is a front view showing a rotating device suitable for using the teaching mechanism according to the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a plan view of essential parts showing an embodiment of the present invention.
4 is a longitudinal sectional view of FIG. 3, and FIGS. 5 and 6 are explanatory diagrams of the operation of FIG. 3, respectively. 1...Rotating shaft, 2...Floating dog, 8
... Spring, 9 ... Stopper, 11-13 ... Detector.

Claims (1)

[Claims] 1. A rotating shaft that is rotated so as to overlap with each other due to left and right rotation of the rotating shaft, and a floating dog that is rotatably disposed with respect to the rotating shaft;
a spring support member integrally supported with the rotating shaft; a pair of spring members whose ends are supported by the floating dog and the spring support member to bias the floating dog in the rightward and leftward directions, respectively; A stopper restricts the left and right rotational positions of the floating dog to respective predetermined positions so that the floating dogs do not overlap even when the shafts are rotated so as to overlap, and a rightward rotation and a leftward rotation controlled by the stopper are provided. A rotational direction teaching mechanism for a rotating shaft, comprising a first detector for respectively detecting a floating dog, and a dog and a second detector for detecting a non-overlapping rotational position state of the rotating shaft. .