JPH05293788A - Rotary joint device for robot wrist - Google Patents

Abstract

PURPOSE:To prevent the occurrence of the slack, draw up, and sagging of an air hose, a control signal line, and a current collecting cable for weld, which are positioned in the vicinity of the wrist of a robot. CONSTITUTION:A rotary joint mechanism 14 is provided for comprising a joint rotary body 12 rotated following movement of an output drive part 10 for a wrist and provided at a tip part with an attaching mount 8 for a cylinder, and a joint fixing body 13 which surrounds a part of the outer periphery of the joint rotary body 12 and integrally mounted on an output fixing part 9 for a wrist. The joint fixing body 13 is provided with an air intake port 20 to introduce air for working, a signal line lead-in port 21 through which an electric wiring 3 for transmitting a control signal is introduced, and a cable mounting part 22 to which a current collecting cable 4 for weld. Even when a wrist is widely rotated, interference of an air hose 2, protruded from the joint rotary body 12, with a peripheral device and contact of them with each other are prevented from occurring and receiving of a weld heat and spatter is reduced as low as possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary joint device for a robot wrist, and more specifically, to an air hose provided around a link or arm tip of a robot and rotating around a wrist and an electric signal for control signals. A rotary joint mechanism that allows wiring and welding current collection cables to be compacted so that they do not get caught or damaged by the rotation of the wrist, and do not interfere with welding work due to excessive slack. It is about.

[0002]

2. Description of the Related Art Industrial robots, especially arc welding robots, require not only a welding current collecting cable, but also a hand for holding a workpiece on a rotating wrist provided at the tip of the robot. A chuck or the like is attached, and in addition, an actuator for operating the hand or the like, an electromagnetic valve for controlling the supply of operating air, and the like are also attached. Therefore, the wrist has an air hose that supplies operating air from the robot body to the actuator, electrical wiring that transmits control signals to the solenoid valve, and the above-mentioned welding current collection cable that collects welding current. Will be connected. If the movement of the robot is simple or the range of movement is narrow, even if the air hose, electric wiring for control, current collecting cable for welding, etc. are connected to the wrist in an appropriate state, Does not get in the way. However, if the robot device is a 6-axis manipulator, the position of the wrist will be complicatedly displaced with respect to the robot body, and some rotational movements will overlap, so air hoses, electrical wiring, current collection cables, etc. Must be long enough so that it does not interfere with any movement of the wrist.

[0003]

FIG. 8 shows an example in which the air hose, the electric wiring for control, the current collecting cable for welding, etc. are connected to the wrist. A wrist mechanism is attached to the tip of a wrist shaft 1 of a robot apparatus as a 6-axis manipulator so that a workpiece 6 can be held via, for example, the hands 5 and 5. When the hands 5 and 5 are of a type that holds the workpiece 6 as shown in the drawing, the cylinders 7 and 7 for moving the hands 5 are mounted on the mounting mount 8 mounted on the wrist. The wrist is provided with an output fixing portion 9 integrated with the wrist main body and an output driving portion 10 which is rotationally driven with respect to the wrist fixing body, but since the mounting mount 8 is adapted to rotate together with the output driving portion 10, A considerable margin is given to the length of the welding current collecting cable 4 connected to the wire 5. Similarly, the air hose 2 for supplying the operating air to the cylinders 7, 7 and the electric wiring 3 for transmitting the control signal to the solenoid valve (not shown) for controlling the supply of the operating air also have a length sufficient for movement of the wrist. Has been secured. A hanger 11 is attached to the wrist shaft 1 in order to support these air hoses 2 and the like pulled out from the robot body near the wrist. The air hoses described above are supported at several positions from the robot base (not shown) to the hangers, and a considerable margin is secured so as not to obstruct the movement of the robot links and arms. In the case of a 6-axis manipulator, if the robot main body and the five joints are arranged along the links between them, a large margin is not required. By the way, in the above example, the welding current collecting cable 4 is pulled along with the movement of the workpiece 6, but the welding current flowing from the arc welding electrode to the workpiece can be reliably collected.
However, in the case of a structure in which the cable mounting seat rotates with respect to the table that holds the workpiece, it is necessary to consider that the electrical connection between the workpiece and the welding current collection cable is sufficient. .. For example, Jitsuko Sho 48-14
Japanese Patent No. 648 discloses a spring mechanism in which a cable mounting seat can be pressed against a table in order to improve the electrical conductivity of both.

By the way, in recent years, welding is often performed while rotating a work piece, and the output drive portion of the wrist may require a rotation amount of one rotation or more. In such a case, an extremely complicated movement and followability are required for the air hose or the like between the above hanger and each connection position. In such a case, if there is little movement of the wrist relative to the robot body, the air hose etc. will become loose near the wrist,
It touches the work piece and also sways and entangles with other attachments and peripherals. On the other hand, when the movement of the wrist becomes complicated, things that are easily deformed, such as the air hose and the electric wiring for control, cling to accessories near the wrist, and when the movement of the wrist returns, the air hose etc. are easy. There is also a situation where it cannot be restored without being lost. In this way, when the air hose behaves in various ways as the wrist moves, fatigue occurs in the meantime, and its damage and wear are remarkable due to mutual contact and rubbing with peripheral devices,
There is a problem that it cannot withstand long-term use and hinders stable operation of the robot device. In extreme cases, an air hose or the like approaches the welding site, and due to the welding heat or the high temperature spatter, the degree of damage becomes even more remarkable. The present invention has been made in view of the above problems, and an object of the present invention is to avoid the occurrence of slack, twitching, or drooping of an air hose, a control signal line, a welding current collecting cable, or the like near the wrist of a robot. Prevent air hoses from interfering with peripheral devices and prevent mutual contact.
(EN) A rotary joint device for a robot wrist, which can prevent welding heat and spatter from being damaged as much as possible. The inventor has introduced a rotary joint mechanism to the wrist in order to achieve the above object. However, the rotary hose, the control signal line, the welding current collecting cable and the like which are indispensable to the welding robot are combined into one rotary joint. The present invention has been completed by conducting repeated research on how to connect and store in the above.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a wrist or a chuck for holding a work piece is attached to a rotating wrist provided at a tip of a robot, and an actuator or an actuator for operating the hand or the like. It is equipped with a solenoid valve that controls the supply of supply air, an air hose that supplies the operating air from the robot body to the wrist, electrical wiring that transmits control signals, and a welding current collection cable that collects welding current. It is applied to the wrist mechanism of industrial robots. With respect to the feature, referring to FIG. 1, the wrist includes an output fixing portion 9 integrated with the wrist main body and an output driving portion 10 that is rotationally driven with respect to the output fixing portion 9. It encloses a joint rotary body 12 that rotates with the movement of the output drive unit 10 and has a mounting mount 8 such as an actuator 7 (see FIG. 2) attached to the tip end, and a part of the outer periphery of the joint rotary body 12. A rotary joint mechanism 14 including a joint fixing body 13 integrally attached to the output fixing portion 9 is provided. The joint fixing body 13 has an air intake 20 for introducing the operating air supplied to the actuator 7 to the joint rotating body 12, and an electric wire 3 for transmitting a control signal to the joint rotating body 12. Signal line intake 21,
A cable attachment portion 22 for slidingly connecting the welding current collecting cable 4 to the joint rotating body 12 having electrical conductivity is provided.

The electric wiring 3 for transmitting the control signal is
A flat cable 27 is provided at least in the rotary joint mechanism 14, and the joint rotating body 12 is provided inside the signal line inlet 21 in the joint fixing body 13.
An annular storage space 28 (see FIG. 5) in which the flat cable 27 is loosely wound in multiple layers is formed between the flat cable 2 and the outer peripheral surface of the flat cable 27.
In order to introduce 7 into the cable space 29 formed in the central portion of the joint rotating body 12, it is preferable to form a slit groove 30 extending inward. A spring 32, in which the cable attachment portion 22 for the welding current collecting cable 4 attached to the joint fixing body 13 is pressed against the joint rotating body 12, is interposed in the joint fixing body 13. It is preferable to interpose an electrical insulating member 33 between the cable mounting portion 22 and the spring 32 that presses the cable mounting portion 22 against the joint rotating body 12.

A rotary stopper ring plate 35 capable of rotating around the joint rotary body 12 of the rotary joint mechanism 14 is externally fitted to the joint rotary body 12, and the rotary stopper ring plate 35 is provided in the joint fixed body 13. A stopper space 26 for accommodating the is secured. A stopper hook 36 is planted on the outer peripheral surface of the joint rotating body 12 toward the rotation stopper ring plate 35, and when the stopper hook 36 comes into contact with the groove end after the joint rotating body 12 is idled and rotated, the joint rotating body 12 An arcuate hook movement groove 37 (see FIG. 7) in which the rotation stopper ring plate 35 is rotated in accordance with the rotation of 12 is formed in the inner peripheral portion of the rotation stopper ring plate 35. A stopper pin 38 projecting toward the stopper space 26 is planted in the joint fixing body 13, and the outer peripheral surface of the rotation stopper ring plate 35 is
When the rotation stopper ring plate 35 makes one full rotation, it abuts on the stopper pin 38 to prevent the rotation stopper ring plate 35 from rotating further.
(See FIG. 7) is preferably formed.

[0008]

The rotating mechanism of the wrist is driven to rotate the output drive section 10 with respect to the output fixing section 9 integrated with the wrist body. With the movement of the output drive unit 10, the rotary joint mechanism 1
The joint rotating body 12 of 4 rotates and the work piece 6 together with the actuator 7 mounted on the mounting mount 8 and the like.
(See FIG. 2) is also rotated. At this time, the joint fixing body 13 which surrounds a part of the outer periphery of the joint rotating body 12 and is integrated with the output fixing portion 9 maintains the stationary state. The joint fixing body 13 is provided with the air intakes 20, 20, the signal line intake 21, and the cable attachment portion 22, but these also remain stationary. Air hose extending from the robot body 2, electric wiring for transmitting control signals 3,
The welding current collecting cables 4 for collecting the welding current are connected to each other, but similarly, they do not move with the rotation of the wrist. From the air intake 20 to the rotary joint mechanism 1
The operating air introduced into the No. 4 is led out to the mounting mount 8 side through the joint rotating body 12. Signal line entrance 21
The electric wiring 3 inserted from the above is also drawn out to the vicinity of the mounting mount 8 through the joint rotating body 12. The welding current collecting cable 4 connected to the cable attachment portion 22 is maintained in electrical connection with the joint rotating body 12 in a sliding contact state. The output driving unit 10 is rotated, and the joint fixed body 13 and the joint rotating body 12 of the rotary joint mechanism 14 are rotated.
Even if and slide and rotate, the operating air supply passages are continuous, and the operating air can be supplied. Electrical wiring 3
Moves inside the rotary joint mechanism 14, but does not move outside the wrist. The welding current collecting cable 4 remains fixed to the joint fixing body 13 and maintains a constant posture with respect to the wrist body.

If the electric wiring 3 is a flat cable 27 at least inside the rotary joint mechanism 14 and the flat cable 27 is loosely wound in multiple layers inside the signal line inlet 21, it is possible to rotate the wrist. Accordingly, the flat cable 27 is wound or unwound in the state of multiple winding. If the flat cable 27 is made to perform such a behavior, the flat cable 2
7 can be stored compactly. When the spring 32 for pressing the cable attachment portion 22 for the welding current collecting cable 4 to the joint rotating body 12 is provided, the joint rotating body 12 of the rotary joint mechanism 14 rotates with respect to the joint fixed body 13. Also, the cable mounting portion 22 is surely secured by the elastic force of the spring 32 to the joint rotating body 12
The welding current is reliably collected by the welding current collecting cable 4 through the pressing surface. When the electrical insulating member 33 is interposed between the cable attachment portion 22 and the spring 32, the electrically conductive rotary joint mechanism 14 is connected to the spring 32 that is electrically cut off by the electrical insulating member 33. No welding current flows through it.

A rotary stopper ring plate 35, which can rotate around the joint rotating body 12 of the rotary joint mechanism 14, is fitted onto the joint rotating body 12, and a stopper space 26 for accommodating the rotary stopper ring plate 35 is secured in the joint fixed body 13. With this setting, the rotation angle of the wrist can be made as large as possible. When the joint rotating body 12 rotates, the stopper hook 36 planted on the outer peripheral surface of the joint rotating body 12 floats in the arcuate hook movement groove 37 formed in the stopper ring plate 35. During this period, the joint rotating body 12 is, for example, 4
Rotate 5 degrees. When the stopper hook 36 comes into contact with the groove end of the arcuate hook movement groove 37 after the rotation, the rotation stopper ring plate 35 also rotates as the joint rotating body 12 rotates. Rotation stopper ring plate 35
Is rotated about 180 degrees, for example, the stopper 35a formed on the outer peripheral surface of the rotation stopper ring plate 35
However, when it reaches the topper pin 38 projecting from the joint fixed body 13 toward the stopper space 26, the rotation stopper ring plate 35 is prevented from further rotating.
The rotation of the joint rotating body 12 also stops, but the joint rotating body 12 has rotated about 215 degrees. When the joint rotating body 12 is rotated in the opposite direction in the same manner, the joint rotating body 12 also rotates 215 degrees. When the joint rotary body 12 is rotated via the rotation stopper ring plate 35 in this manner, a total rotation of 430 degrees is realized.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings showing the embodiments thereof. FIG. 1 is a detailed cross-sectional view of the vicinity of a wrist of a robot to which the rotary joint device according to the present invention is applied. This is applied to a wrist mechanism attached to the tip of the wrist shaft 1 of a robot device as a 6-axis manipulator, as shown in FIG. An air hose 2, an electric wire 3 for control, and a welding current collecting cable 4 are connected to the wrist mechanism. Then, the circular cross-section portion of the workpiece 6 is held from the outer periphery thereof via the hands 5 and 5. The left and right cylinders 7, 7 for moving the hand 5 are mounted on a mounting mount 8 mounted on the wrist. A rotation driving mechanism (not shown) is built in the wrist, and the wrist main body is provided with an output fixing portion 9 and an output driving portion 10 which are rotationally driven with respect to the wrist main body, and the mounting mount 8 rotates together with the output driving portion 10. It is supposed to do. The welding current collecting cable 4 described above collects the welding current flowing through the workpiece 6 through an arc welding electrode (not shown) and guides it to the ground. on the other hand,
The air hose 2 is connected to cylinders 7, 7 which are actuators for moving the hands 5, 5 and supplies operating air. The electric wiring 3 supplies air for operation to the cylinder 7,
The control signal is output to a solenoid valve (not shown) that controls the supply to the solenoid 7. By the way, a hanger 11 is attached to the wrist shaft 1, and an air hose 2, an electric wire 3, a welding current collecting cable 4 and other wires and wires provided as necessary, which are drawn out from the robot body, are provided near the wrist. I am supposed to support it.

In the wrist of such a robot, as shown in FIG. 1, the joint rotating body 12 rotates in accordance with the movement of the output drive unit 10 and has a mounting mount 8 for the cylinder 7 or the like mounted on the tip thereof. A rotary joint mechanism 14 is provided, which includes a joint fixing body 13 that surrounds a part of the outer periphery of the joint rotating body 12 and is integrally attached to the output fixing portion 9. In the case of this example, the joint rotating body 12 includes a base joint 12A, a tubular joint 12B, and a tip joint 12C. Then, the base joint 12A is fixed with a bolt 16 or the like via the insulator 15 fitted in the shallow recess. The rotary joint mechanism 14 itself is electrically conductive because it needs to guide the welding current flowing through the electrode for arc welding to the welding current collecting cable 4, but it is electrically insulated from the wrist. Therefore, the insulator 15 described above is interposed.
Therefore, in order to prevent the welding current from flowing through the bolt 16 as well, a cylindrical insulating spacer 17 is adopted at a position where the bolt 16 is supported by the base joint 12A. The cylindrical joint 12B described above is integrated with the base joint 12A by some bolts 18. The cylindrical joint 12B is composed of a flange portion 12a and a cylinder portion 12b, and the joint fixing body 13 is covered so as to surround the cylinder portion 12b. The tip joint 12C is formed by the four bolts 19 and 19 at the position shown in FIG.
When the output drive unit 10 is rotated as a result of being fixed to the front surface of B, the mounting mount 8 attached to the tip of the joint rotating body 12 is attached via the base joint 12A, the tubular joint 12B, and the tip joint 12C. It can be rotated integrally. The joint fixing body 13 of the rotary joint mechanism 14 is fixed so as to maintain a stationary state by the fixing arm member 42 locked to the output fixing portion 9 via the insulating block 41 shown in FIG. There is. The joint fixing body 13 includes a cylinder 7,
1, the air intake 20 for introducing the operating air supplied into the joint rotating body 12 shown in FIG. 1, and the electric wiring 3 for transmitting the control signal to the solenoid valve etc.
2 is provided with a signal wire inlet 21 for introduction into the inside of the cable 2, and a cable attachment portion 22 for connecting the welding current collecting cable 4 to the electrically conductive rotary joint mechanism 14.

Two air intakes 20 are provided for the two cylinders 7, 7 so that the air hoses 2, 2 can be connected to each other. The air intakes 20 and 20 are connected to the air passages 20a and 20b that extend in the joint fixed body 13 in the radial direction, and are provided between the inner peripheral portion of the joint fixed body 13 and the outer peripheral portion of the cylinder portion 12b of the tubular joint 12B. The formed circular passage 20m,
It is connected to each 20n. This ring passage 20
m and 20n respectively extend in the axial direction of the cylinder portion 12b and are independently provided in the air supply passages 20p and 20q (the air supply passage 20q is located on the inner side of the air supply passage 20p and is represented in FIG. 1). Not). These air supply passages 20p, 20q are connected to the exhaust passages 20r, 20s extending in the radial direction inside the tip joint 12C, and are connected to the air outlets 23, 23. Air hoses 2A, 2A as shown in the air outlets 23, 23
Are connected, and the supplied operating air is sent via an electromagnetic valve (not shown) to operate each cylinder 7 (see FIG. 2). In order to prevent air leakage and mutual ventilation in the annular passages 20m and 20n, three pieces are provided between the inner peripheral surface of the cylindrical joint 13A and the outer peripheral surface of the cylinder portion 12b of the joint fixing body 13 described below. O-ring 2
5, 25 are interposed. Of course, it is needless to say that if the number of O-rings is increased and the number of annular passages is increased, the number of actuators can be increased to 2 ports, 4 ports, or 6 ports to accommodate a large number of actuators. In the case of this example, the joint fixing body 13 of the rotary joint mechanism 14 includes a cylindrical joint 13A and a hollow ring joint 13B that forms an annular storage space 28 described later. A stopper space 26 for accommodating a rotation stopper ring plate 35 described later is secured between the cylindrical joint 13A and the hollow ring joint 13B.

The above-mentioned signal line inlet 21 is provided on the outer peripheral surface of the hollow ring joint 13B so that a control signal sent to an electromagnetic valve or the like through the joint rotating body 12 can be introduced into the fixed joint body 13. It has become. As described above, the so-called flat cable 27 is adopted at least in the rotary joint mechanism 14 as the electric wiring 3 for transmitting the control signal, and a large number of signals are integrated into one line to facilitate the wiring. Although not shown in detail in this example, it has 12 cores, for example.
However, if the width of the annular storage space 28 is widened, the number of cores of the signal line can be increased. Signal line inlet 2 mentioned above
1, the cylinder portion 12 of the joint rotating body 12
An annular storage space 28 for accommodating the flat cable 27 in a loosely wound manner is formed between the peripheral surface b and the peripheral surface. And
In the tubular joint 12B of the joint rotating body 12, a cable space 29 is formed in the central portion thereof, and the flat cable 27 is introduced into the cable space 29 in the tubular joint 12B as shown in FIG. In order to do so, a slit groove 30 extending inward is formed. As can be seen from FIG. 5, the annular storage space 28 is wide enough to leave spaces 28a and 28b outside and inside even when the flat cable 27 is wound in multiple layers. Therefore, as will be described later, when the wrist is greatly rotated in one direction, the multiple flat cables 27
Even if is unwound, there is still room for the flat cable 27 to spread. When the wrist is rotated in the other direction, the flat cable 27 is caught, but in this case, the wound state has a margin as shown in FIG.

In FIG. 1, a conductive cable mounting portion 22 for connecting the welding current collecting cable 4 to the rotary joint mechanism 14 is disk-shaped, and the flange portion 12a of the tubular joint 12B and the joint fixing body 13 are provided. It is attached to the cylindrical joint 13A. A connecting protrusion 22a protruding outward from the flange 12a is formed at one location on the peripheral portion of the disc, and the connecting fitting of the welding current collecting cable 4 is fixed by a bolt 31 in a hole provided therein. Is becoming The cable mounting portion 22 of the welding current collecting cable 4 is pressed against the joint rotating body 12 so as to have a sufficient electrical connection with the rotating joint rotating body 12. Therefore, the spring 32 is provided in the cylindrical joint 13A. Is housed. This spring 32
A coil spring is adopted as the coil spring, and the coil spring is housed horizontally in the posture shown in FIG. 1 so that the elastic force of the coil spring extends to the cable attachment portion 22 in the cylindrical space provided inside the cylindrical joint 13A. ing. The cable mounting portion 22
The spring 3 so that a uniform and even force is exerted on
2 are inserted in voids provided at four locations on the circumference of the cylindrical joint 13A (other three voids are not shown). If the pressing force of the spring 32 is used, the sliding contact of the cable mounting portion 22 with the joint rotating body 12 is also maintained. The rotary joint mechanism 14 is electrically conductive as described above, and the workpiece 6
The welding current that has flowed to the mounting mount 8 through the hand 5 and the like passes through the rotary joint mechanism 14 and is collected in the cable mounting portion 22. At that time, if a current flows through the spring 32, the spring 32 will generate resistance and heat, and the spring function will be deteriorated.
In order to avoid this, in this example, the spring 3
An electrical insulating member 33 is interposed between the cable 2 and the cable attachment portion 22.

As described above, the cable mounting portion 22 needs to be mounted between the flange portion 12a and the cylindrical joint 13A. For example, as shown in FIG. 6, the cable mounting portion 22 is radiused by the spring 32A. It may be biased in the direction. In this figure, a space for housing the cable attachment portion 22 is secured between the end surface of the cylindrical joint 13A and the flange portion 12a of the tubular joint 12B. Then, the support arm portion 34 protruding so as to overhang in this space
Is provided at one place on the outer peripheral surface of the cylindrical joint 13A,
The metal fitting for connecting the welding current collecting cable 4 can be locked in the hole 34a formed therein. On the other hand, the other end of the cable attachment portion 22 is a block head 34b that is in sliding contact with the side surface of the flange portion 12a and the outer periphery of the cylinder portion 12b, and the welding current flowing through the joint rotating body 12 is collected in the cable attachment portion 22. It is designed to be powered. A spring 32A for pressing the block head 34b into contact with the cylinder portion 12b is attached so as to surround a thin shaft portion from the top of the block head 34b to the tip portion to which the welding current collecting cable 4 is connected. .. Even in this case, the spring 32
In order to prevent the welding current from flowing to A, it is preferable to provide electric insulating members 33A and 33B.

Returning to FIG. 1, the joint rotating body 12 has a rotation stopper ring plate 35 which can rotate around the cylinder portion 12b of the cylindrical joint 12B.
Is fitted. This rotation stopper ring plate 3
A stopper space 26 is secured in the joint fixing body 13 for accommodating 5. As shown in FIG. 7, a stopper hook 36 is planted on the outer peripheral surface of the cylinder portion 12b toward the rotation stopper ring plate 35. When the stopper hook 36 comes into contact with the groove end after the cylinder portion 12b is rotatively rotated on a part of the inner periphery of the rotation stopper ring plate 35, the rotation stopper ring plate 35 is rotated along with the rotation of the joint rotating body 12. An arc-shaped hook movement groove 37 that can be formed is formed. In this example, the hook movement groove 37 occupies about 1/4 of the inner circumference circle of the rotation stopper ring plate 35. On the other hand, a stopper pin 38 that projects toward the stopper space 26 is planted on the end surface of the cylindrical joint 13A of the joint fixing body 13 (see FIG. 1). Then, when the rotation stopper ring plate 35 makes one full rotation, the stopper pin 38 is formed on the outer peripheral surface of the rotation stopper ring plate 35.
And a stopper 35a for preventing further rotation of the rotation stopper ring plate 35 is formed.

Such a rotation stopper ring plate 3
If No. 5 is adopted, the joint rotating body 12 can rotate at a large angle with respect to the joint fixed body 13 by the rotation of the output driving unit 10 of the wrist. That is, assuming that the width of the stopper 35a is equal to 10 degrees of the rotation angle of the rotation stopper ring plate 35, the range in which the rotation stopper ring plate 35 can rotate forward and backward is about 350 degrees. On the other hand, the range in which the cylinder portion 12b can freely move in the arc-shaped hook movement groove 7 of the rotation stopper ring plate 35 is 90 degrees. Therefore, if the stopper hook 36 planted in the cylinder portion 12b is in a solid line state, the cylinder portion 12 is moved until the stopper hook 36 moves from that position to the state of a one-dot chain line.
b freely rotates 90 degrees in the rotation stopper ring plate 35. After that, when the cylinder portion 12b continues to rotate in the same direction, the rotation stopper ring plate 35 is rotated in the same direction while the stopper hook 36 is in contact with the groove end of the hook movement groove 7. Rotation stopper ring plate 35 is about 3
When rotated 50 degrees, the stopper 3
5a hits the stopper pin 38 to prevent the rotation stopper ring plate 35 from further rotating, and at the same time, the cylinder portion 12b cannot rotate. As can be seen from this, the cylinder portion 12b of the joint rotating body 12 is
Can rotate 90 degrees + 350 degrees-an angle corresponding to the width of the stopper pin 38 (for example, 5 degrees) = 435 degrees. Therefore, the angle at which the output driving unit 10 on the wrist can rotate with respect to the output fixing unit 9 is approximately ± 215 degrees, and the workpiece 6 held by the hands 5 and 5 is 180 degrees.
It can be rotated more than a degree. Therefore, even when welding the opposite side or the back side of the work piece 6, without rotating the work piece 6 to the opposite side, the desired portion can be immediately arc-welded by continuing the rotation until now and rotating in the same direction. You will be able to Although the rotation stopper ring plate 35 is formed with an arcuate hook movement groove 37 to secure a floating area for the stopper hook 36, the movement groove 37 does not have to be groove-shaped. , In short, the tubular joint 12
It suffices that the B and the rotation stopper ring plate 35 rotate integrally with each other after the relative rotation.

According to the structure described above, a part of the air hose 2, the electric wiring 3, and the welding current collecting cable 4 attached to the periphery of the wrist are housed in the rotary joint mechanism 14 as described below, and a large rotation of the wrist is achieved. It is possible to avoid mutual interference and the like while permitting. When receiving a command to rotate the wrist while holding the workpiece 6 with the hands 5 and 5 as shown in FIG. 2, the output drive unit 10 shown in FIG. 1 starts rotating with respect to the output fixing unit 9. Although the joint rotary body 12 rotates due to the rotation of the output drive unit 10,
The joint fixing body 13 is kept stationary by the fixing arm member 42 (see FIG. 4). The air hoses 2 and 2 for supplying operating air to the cylinders 7 and 7 are the air intake 2
Although connected to Nos. 0 and 20, the cylindrical joint 13A is stationary and each air hose 2 does not move or twist. The operating air is supplied to the air passages 20a, 2
It flows from 0b to the annular passages 20m and 20n. Even if the cylindrical joint 12B is rotated in the cylindrical joint 13A, the cylinder portion 12 is not removed from the annular passages 20m and 20n.
It is supplied to the air supply passages 20p and 20q formed in b, and is led out to the air hoses 2A and 2A connected to the air outlets 23 and 23 through the discharge passages 20r and 20s of the tip joint 12C. Bolt 39 on the front of the tip joint 12C
Although the cylinders 7 and 7 are mounted on the mounting mount 8 mounted in step 2 (see FIG. 2), the cylinders 7 and 7 are rotated simultaneously with the air hoses 2A and 2A.
A and 2A also maintain the mounting posture and do not come into contact with or entangle with each other.

The electric wiring 3 for transmitting a command signal from the control box of the robot body is also inserted from the signal line inlet 21 provided in the cylindrical joint 13A which is stationary regardless of the rotation of the wrist. Then, in the annular storage space 28 shown in FIG. 5, the windings are overlapped in a loosely wound state, and the tip thereof enters the cable space 29 of the cylinder portion 12b through the slit groove 30 and is pulled out from the side of the tip joint 12C. Then, as indicated by the phantom line in FIG.
A passes through the side of the mounting mount 8, etc.
Is connected to the solenoid of the solenoid valve that controls the supply of operating air. The solenoid valve is rotated together with the tip joint 12C, but the electric wiring 3A from the tip joint 12C
Is always constant and does not get caught or twisted. The flat cable 27 may be wound or unwound in the annular storage space 28 due to the rotation of the wrist.
8b remains and does not hinder the rotation of the wrist.
The welding power collection cable 4 is connected to the rotary joint mechanism 14 via the cable attachment portion 22. The cable attachment portion 22 is formed by a plurality of pins 40, and the cylindrical joint 13
It is fixed to A and does not rotate even if the cylindrical joint 12B rotates. The welding current from the electrode for arc welding is transmitted through the mounting mount 8 to the rotary joint mechanism 14
And flows through the welding current collecting cable 4 without passing through the spring 32.

As described in detail above, the air hose,
Even if the electric wiring, the current collecting cable for welding, etc. are long and have high deformability that makes it difficult to maintain their posture, they can be placed around the wrist with a certain posture before and after the rotary joint mechanism. Accumulation of fatigue is largely avoided without being twisted by the rotation of the wrist. Also, the air hose will not hang around the wrist, stretch, or twitch. Therefore, they do not come into contact with each other and wear and they do not get entangled with the peripherals. Furthermore, since the mounting position is constant while maintaining a predetermined posture, it does not approach the work piece or welding spots undesirably, does not receive welding heat or spatter, and wear and damage can occur. Suppressed to. Although an air cylinder is used as an actuator mounted on the mounting mount and a hand that moves forward and backward is used as a device for gripping a workpiece, the hand itself has a mechanism that opens and closes its claws, or an actuator. Can be used as a pneumatic motor, or a workpiece may be gripped by a chuck or the like, and various modifications can be adopted.

[0022]

According to the present invention, the rotation of the wrist does not twist the air hose or make contact with the electrical wiring.
The electric wiring itself is not twisted by the rotation of the wrist and does not touch the welding current collecting cable. In any case, the air hose, the electric wiring, and the welding current collecting cable do not come into contact with the equipment around the wrist, slacken and entangle with the work piece, and do not approach the welding site undesirably. Since the air hose or the like does not shake or come into contact with the robot during the work operation, it is possible to reduce fatigue, wear, and wear during that time as much as possible. It is less likely to receive welding heat and spatter, and the durability around the wrist device is improved.
When the electric wiring is a flat cable and the flat cable is to be loosely wound in multiple layers inside the signal line inlet, the flat cable can be maintained while maintaining the function of the flat cable while keeping the narrow space inside the rotary joint mechanism. It can be stored compactly in space. If a spring that press-connects the cable mounting part for the welding current collecting cable to the joint rotating body is provided, the welding current can be reliably collected.
The robot's welding work is always smooth and smooth, and the operation is stable. If an electrical insulating member is interposed between the cable attachment part and the above-mentioned spring, the spring will not be electrically heated and the weakening of the spring will be suppressed, and the pressure attachment state between the cable attachment part and the joint rotating body will be maintained for a long period of time. In addition, the cable attachment portion can be kept in a slidable contact state with the joint rotating body. When a rotary stopper ring plate that can rotate around the joint rotary body of the rotary joint mechanism is externally fitted and a stopper space for accommodating the rotary stopper ring plate is secured in the joint fixed body, the rotary joint mechanism The joint rotating body can be rotated at a large angle of 360 degrees or more. As a result, it is possible to rotate the workpiece largely while holding it by the operation of the actuator, and it is possible to perform welding without turning the workpiece in the opposite direction during the welding work, which speeds up the welding work. And the operating efficiency of robots can be improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a wrist portion including a rotary joint mechanism according to the present invention.

FIG. 2 is a schematic view of a tip portion of the robot apparatus showing the vicinity of a wrist portion.

3 is an end view taken along the line III-III of FIG.

FIG. 4 is an external view of a rotary joint mechanism.

5 is a cross-sectional view taken along the line VV of FIG.

FIG. 6 is a partial cross-sectional view showing another example of the cable attachment portion.

7 is a sectional view taken along the line VII-VII of FIG.

FIG. 8 is a schematic view of a tip portion of a robot device showing a conventional wiring / piping state.

[Explanation of symbols]

2, 2A ... Air hose, 3, 3A ... Electric wiring, 4 ... Welding collector cable, 5 ... Hand, 6 ... Workpiece, 7 ...
Actuator (cylinder), 8 ... Mounting mount, 9 ...
Output fixing part, 10 ... Output driving part, 12 ... Joint rotating body, 13 ... Joint fixing body, 14 ... Rotary joint mechanism, 20 ... Air inlet, 21 ... Signal line inlet, 22
... Cable mounting portion, 26 ... Stopper space, 27 ... Flat cable, 28 ... Annular storage space, 29 ... Cable space, 32, 32A ... Spring, 33, 33A, 33B
… Electrical insulation member, 35… Rotation stopper ring plate,
35a ... stopper, 36 ... stopper hook, 37 ... hook movement groove, 38 ... stopper pin.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location H02G 11/00 A 7373-5G

Claims (5)

[Claims] 1. A hand, a chuck, etc. for holding a work piece, an actuator for activating the hand, etc., and a solenoid valve for controlling the supply of operating air to a wrist provided on the tip of a robot for rotation. In a wrist mechanism of an industrial robot, which is equipped with an air hose that supplies the operating air from the robot body to the wrist, electrical wiring that transmits a control signal, and a welding current collection cable that collects welding current The wrist includes an output fixing portion that is integral with the wrist body and an output driving portion that is rotationally driven with respect to the output fixing portion. The wrist rotates with the movement of the output driving portion, and the actuator or the like is attached to the tip portion. And a joint rotary body equipped with the mounting mount of FIG. A rotary joint mechanism including a joint fixing body is provided, and the joint fixing body is provided with an air inlet for introducing the operating air supplied to the actuator into the joint rotating body, and an electrical wiring for transmitting a control signal. A robot characterized by being provided with a signal wire inlet for introducing into the joint rotating body and a cable attaching portion for slidingly connecting the welding current collecting cable to the joint rotating body having electric conductivity. Rotary joint device for wrist. 2. The electric wiring for transmitting the control signal is a flat cable at least in the rotary joint mechanism, and an inner peripheral surface of the joint rotating body is provided inside a signal wire inlet of the joint fixed body. In order to introduce the flat cable into the cable space formed in the central portion of the joint rotary body, an annular storage space is formed between the flat rotary cables for loosely winding the flat cable in multiple layers. The rotary joint device for a robot wrist according to claim 1, wherein a slit groove extending inward is formed. 3. A spring for pressing a cable attachment portion for a welding current collecting cable attached to the joint fixed body to the joint rotary body is interposed in the joint fixed body. A rotary joint device for a wrist of a robot described in. 4. An electrical insulating member is interposed between the cable mounting portion and a spring that presses the cable mounting portion against a joint rotating body.
A rotary joint device for a wrist of a robot described in. 5. A rotary stopper ring plate capable of rotating around the joint rotary body of the rotary joint mechanism is externally fitted to the joint rotary body, and a stopper for housing the rotary stopper ring plate in the joint fixed body. A space is secured, a stopper hook is planted on the outer peripheral surface of the joint rotating body toward the rotation stopper ring plate, and when the stopper hook comes into contact with the groove end after the joint rotating body rotates idle, the joint hook An arcuate hook movement groove capable of rotating the rotation stopper ring plate in accordance with the rotation of the rotating body is formed in an inner peripheral portion of the rotation stopper ring plate, and the joint fixed body faces the stopper space. Stopper pin that protrudes from the 7. A stopper is formed on the outer peripheral surface of the cover, the stopper being in contact with the stopper pin when the rotation stopper ring plate makes one full rotation and preventing further rotation of the rotation stopper ring plate. 1. The rotary joint device for a robot wrist as described in 1.