JPH07156093A - Cable handling device in articulated part of industrial robot - Google Patents

Abstract

PURPOSE:To promote an increase in the turning angle value of a robot constituent parts in improving a cable handling device to be installed in an articulated part provided with a horizontal turning center of an industrial robot and prevent any injury and damage to a cable being from caused. CONSTITUTION:A cylinder 16 equipped with a proper cable winding surface is installed in the articulated part of a robot machine body free of integral rotation together with a rotating member side 14, while one end of a cable support member 20 is attached to this cylinder 16, and the other end of this cable support member is attached to a member side or an irrotational member 12 pertaining to motion around a center line of the articulated part. In addition, the cable support member provided with specified length to be selected in response to a turning angle value of the rotating member 14 is floated or hung down in an interspace secured along the side of the irrotational member 12, whereby the cable support member 20 is wound and/or rewound according to each rotation of the rotating member and the cylinder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable processing device for a joint portion of an industrial robot, and more particularly to a multi-joint vertical robot or the like having two robot components which relatively rotate about at least one horizontal axis. The present invention relates to a cable processing device for laying a cable that passes through a joint area of a robot body without causing a reduction in robot operation function and without causing cable damage.

[0002]

2. Description of the Related Art Industrial robots are widely used in various mass production lines and the like to contribute to improvement of production efficiency, labor saving, and area saving of production plants. In particular, in automobile production lines, etc., it is required to increase the mobility and work range of each industrial robot in order to further improve productivity and save area, and the robot body itself associated with robot operation is required. It is required to reduce the interference area.

On the other hand, an electric motor as a drive source and a fluid actuated cylinder are mounted as indispensable elements for the operation of end effectors such as a robot body, a robot arm, a robot wrist, and a robot hand, which are movable parts of an industrial robot. Further, a means for supplying a work auxiliary fluid for work such as welding and cutting performed by the end effector is also provided as an essential element. For this reason, electric cables and piping pipes (collectively referred to as cables) are laid on the robot body for supplying driving power to the motor, transmitting and receiving control signals, and supplying pressurized air and auxiliary fluid gas. It is essential, and there is always a demand for improvement in cable processing technology for properly laying the cable inside and around the robot body and laying piping and the like.

In an industrial articulated robot, the robot body has a large number of joints, and a cable passing through these joints causes the amount of rotational movement of the body to be restricted. It also causes damage and deterioration due to stretching and twisting. Therefore, conventionally, various proposals have been made for the cable treatment in the industrial robot. In particular, as a cable processing device in a joint part of a robot arm that rotates around a horizontal axis in a vertical articulated robot, as shown in FIG. Robot arm 2
As a configuration in which the rear end 2a is pivotally attached, and cable processing is performed using the robot body having the joint point 3 as the pivotal attachment point,
When the cable 4 is extended from the robot body 1 side to the robot wrist (not shown) at the tip via the robot arm 2, the robot passes from the center of the robot body 1 to the rotation center of the joint part 3 to move the robot. There is an example in which the cable 4 is bent and laid toward the center line of the arm 2.

As another example, as shown in FIG. 7, the rear end 2a of the robot 2 is cantilevered via a bearing 5 on the side surface of the upper end 1a of the robot body 1, and the rear end 2a of the robot 2 is pivoted. When wiring from the robot torso 1 toward the robot arm 2 that rotates about the rotation center of the joint 3 as the center, the cable 4 passes through the center of the rotation joint 3 There is a configuration in which the cable 4 is twisted.

That is, in both of the above-mentioned two examples, when the robot rotary element rotates, the cable passes through the rotation center of the robot rotary element, thereby setting the bending radius of the cable 4 itself to a reduced value as much as possible. The structure is such that the local tensile load generated in the cable 4 is reduced, or that the cable 4 is twisted at the center of rotation so that the load applied to the cable 4 is reduced as much as possible.

[0007]

However, in the former cable processing means shown in FIG. 6, when the robot arm 2 rotates with respect to the robot body 1, the bending action is repeated on the cable 4, so that the bending angle is changed. If it is large, fatigue damage of the cable 4 is likely to occur, and thus it is difficult to enlarge the rotational movement angle of the robot arm 2 sufficiently to expand the movement function. Moreover, due to the structure of the robot body, it is difficult to apply it when the cable route for laying the cable 4 cannot be secured in the central region of the robot body 1, the rotation center line of the joint 3, or the central region of the robot arm 2. It has the drawback to say.

On the other hand, in the latter cable processing means shown in FIG. 7, since the twisting stress acts on the cable 4, the relative rotation angle of the robot arm 2 with respect to the robot body 1 is, for example, 360 ° (one rotation angle). Since such a large rotation angle cannot be set, there is a drawback that the robot function is limited, and there is a drawback that the cable laying work and maintenance work are not easy.

Thus, conventionally, the cable processing means as shown in FIGS. 6 and 7 has not been sufficient in solving the problems, and when such a central area laying type cable processing means cannot be adopted, After all, a cable processing means is adopted that circulates and lays a cable supporting member that supports and encloses a cable called a well-known product name cable track around the outer periphery of the robot body, and performs wiring processing while protecting the cable. , Such exposed-portion type cable processing means,
There is a problem that mechanical interference is likely to occur at the site where the robot is used.

In view of the above-mentioned problems of the conventional cable processing device, the main object of the present invention is to provide a joint portion of an industrial robot,
In particular, the joint of an industrial robot capable of laying a cable inside the robot body by passing through the joint portion of the robot body having a horizontal axis of rotation and improving the motion function of the robot rotating element. It is to provide a cable processing device in the section.

Another object of the present invention is to provide a cable processing device which can be selected and used even in the case of a machine structure in which it is difficult to lay cables in the central region of each robot constituent element in the robot machine body. .

[0012]

That is, in view of the above-mentioned object, the present invention provides a cylindrical body having an appropriate cable winding surface at a joint portion which forms a pivot point of two relatively rotating members in a robot body. , Particularly preferably, a cylindrical body is integrally rotatably provided on the rotating member side, and one end of a cable track forming a cable supporting member is fixed to the cylindrical body, and the other end of the cable track is around the center line of the joint portion. With respect to the movement of the non-rotating member, a cable track that is fixed to the other non-rotating member side and that has a predetermined length selected according to the rotation angle amount of the rotating member is secured along the non-rotating member side. The cable track is wound up and unwound according to the rotation of the cylindrical body integrated with the rotating member, and the inside of this cable track is used as a cable laying space. There is provided Le processing means.

Therefore, according to the present invention, in the cable processing device extending to the joints of the two robot constituent members that relatively rotate about the horizontal axis in the industrial robot, the rotating member side of the two members is provided. A cylindrical body integrally rotatable with the horizontal axis, and a tip fixed to the cylindrical body, the other end fixed to the non-rotating member side of the two members, and a predetermined floating motion. A flexible cable support member for storing a cable, which has a length and is arranged so as to be wound around and rewound in accordance with the rotation of the cylindrical body, and the flexible cable secured to the non-rotating member side. There is provided a cable processing device in a joint portion of an industrial robot, which is configured to include a cable operation chamber that forms a volume area that can receive the floating portion of the support member.

[0014]

According to the above-mentioned structure, the cable track forming the flexible cable supporting member is wound on the cable winding surface around the tubular body and is unwound from the cable winding surface. By sufficiently securing the desired rotation angle between the two relative rotating members of the robot, it becomes possible to perform cable laying inside the machine body while ensuring a sufficiently large motion angle on the rotating member side. Moreover, since the cables housed in the flexible cable tracks are not subjected to an unreasonable load, the service life of the cables can be sufficiently extended.

Further, due to the structure in which the flexible cable track is simply laid freely along the non-rotating member side, it is necessary to guide the cable supporting member, which has been indispensable for the conventional cable processing means laid on the outer periphery of the robot body. Since no guide member is required, the structure of the cable processing means can be simplified,
It is also possible to obtain cost reduction. In addition, it is preferable that the cylindrical body is used together with a cylindrical body that is generally used when an electric motor such as a servo motor or the like that forms a rotary drive source or a speed reducer is mounted on the robot joint. Further, when the above-mentioned two members which rotate relative to each other are composed of the robot body and the robot arm, the above-mentioned operation chamber of the flexible cable track is formed of a vertical space, and therefore, the cable track is vertically suspended in the hanging state. I am idle.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below based on the embodiments shown in the accompanying drawings. 1 (a), (b)
1 is a schematic front view showing the principle of the configuration of the cable processing device in the joint portion of the industrial robot according to the present invention and a side view taken along the line 1-1 of FIG. 1, and FIGS. 3A is a front view similar to FIG. 3A, which illustrates the operating principle of the cable track associated with the rotation of the rotating member side of the robot body and the rotation of the cylindrical body, and FIG. 3 is a cable treatment at the joint portion of the industrial robot according to the present invention. FIG. 4 is a front sectional view showing a concrete embodiment of the apparatus, and FIGS. 4 and 5 are front views similar to FIG. 3, showing the displacement of the robot body in response to the rotation of the rotating member side and the cylindrical body having the cable winding surface. It is the figure which showed the mode of the cable truck which does.

First, referring to FIGS. 1A and 1B,
The principle diagram of the configuration of the cable processing device according to the present invention is shown in which two relative rotating members in a vertical articulated industrial robot, in particular, a joint portion in which a robot body and a robot upper arm are pivotally connected to each other. ing. FIG. 1 (a),
In (b), the robot body 12 is erected on a robot base (not shown) and constitutes a robot component rotatable about a vertical axis, and a rear end 14a of the robot upper arm 14 has a horizontal axis on its upper end region 12a. The robot arm 14 is rotatably pivoted around a core 15, and at this time, the robot arm 14 is provided laterally at a side portion of the upper end region 12a of the robot body 12 and a cylindrical bearing 16 not shown, together with a rotary bearing (not shown). It is provided so as to be integrally rotatable relative to the robot body 12 via a mechanism,
The outer peripheral surface of the cylindrical body 16 forms a winding surface of the flexible cable track 20 that forms a cable supporting member. The cable track 20 has a sufficient length (a)
As is apparent from the figure, the robot body 12 is provided so as to be vertically slidable along the vertical side portion of the robot body 12, and the tip side 20
“A” is fixed to an appropriate position of the cylindrical body 16 via a fixing member 22. Also, the rear end side 20b of the cable track 20
Are fixed to appropriate positions on the machine side of the robot body 12 using an appropriate clamp 24. A cable 26, which is a bundle of power cables, signal cables, fluid supply cables, etc., is housed and laid in the cable passage inside the cable track 20. The cable 26 inside the cable track 20 is shown from below the robot body 12. Wiring and piping are performed inside the robot arm 14 passing through the passage, and laid toward the robot wrist (not shown).

According to the above configuration, when the robot arm 14 rotates around the central axis 15 of the joint portion provided in the upper end region 12a of the robot body 12 in response to a command from the robot controller, the cylindrical body 16 is rotated. Similarly rotate in both directions around the central axis 15 as indicated by arrow R. At this time, in the illustrated example, the rotation direction R of the cylindrical body 16 in FIG.
Is in the counterclockwise direction, the cable track 20 is wound around the winding surface on the outer periphery of the cylindrical body 16, and therefore the cable track portion hanging toward the machine side of the robot body 12 moves upward. At the same time, the cable 26 laid inside the cable track 20 is also wound around the cable winding surface of the cylindrical body 16.

On the contrary, when the rotation of the cylindrical body 16 is clockwise, the cable track 20 is rewound from the outer periphery of the cylindrical body 16. And the cable track 20 has two ends 2
Since 0a and 20b are fixed to the cylindrical body 16 and to the robot body 12, the floating portion of the cable track 20, that is, the portion that hangs along the machine side of the robot body 12 gradually moves downward. To do. Thus, the cable 26 laid inside the cable track 20 also moves downward.

Referring now to FIGS. 2 (a) and 2 (b),
On the same figure (a) side, the robot arm 14 and the cylindrical body 16 are
From the state shown in FIG. 1 (a), the robot body 12 is rotated clockwise, and therefore the cable track 20
Together with the cable 26 are unwound from the winding surface of the cylindrical body 16 and float along the machine side of the robot body 12 in a free-falling manner. As a result, the cylindrical body 16 and the robot arm 14 are moved by about 180 degrees. It shows a state in which the rotation is allowed over a rotation angle of °.

1B, the robot arm 14 and the cylindrical body 16 are rotated counterclockwise with respect to the robot body 12 from the state shown in FIG. It pivots over and therefore the cable track 20
6 shows a state in which the cylindrical body 16 is wound around the outer peripheral winding surface of the cylindrical body 16 and is moved upward along the machine side of the robot body 12 and wound around the cylindrical body 16.

As is clear from the above description, according to the principle of the cable processing apparatus according to the present invention, the cable track 20 forming the cable supporting member is wound around the winding surface on the outer circumference of the cylindrical body 16 or wound. Since the cable 26 is returned, there is no risk that the cable 26 laid inside the cable track 20 will be subjected to an unreasonable bending or twisting force, and the risk of damage to the cable 26 is eliminated. It is possible to take a sufficiently large rotation angle that is integrated with the cylindrical body 16. Of course, the floating lengths of the cable track 20 and the internal cable 26 are determined according to the amount of rotation angle set in the robot arm 14 at this time.
Moreover, since the restriction that requires the central arrangement for the laying of the cable track 20 and the internal cable 26 is removed, any robot body can be used as long as the floating motion area (cable track operation room) of the cable track 20 can be secured. Also, it becomes possible to provide the cable processing device according to the present invention.

Moreover, since the cable track 20 is allowed to move freely in a free fall state, it has an advantage that no auxiliary means for laying the cable such as a cable track guide is required. Since the cylindrical body 16 is generally used together with the drive motor in the joint portion of the robot body and the mounting cylinder body of the speed reducer, it can be constructed without introducing any new member in the configuration of the cable processing device. Therefore, it is extremely advantageous in terms of manufacturing cost. Although the cylindrical body 16 has a circular cross section, it goes without saying that the same action and effect can be obtained by forming it with a polygonal cylindrical body as necessary.

Next, an embodiment in which the cable processing device of the present invention having the above-described structure and operation effects is applied to the second axis of a 6-axis system articulated industrial robot, that is, the rear end joint portion of the robot upper arm. Will be described with reference to FIGS. Figure 3
Shows an internal structure in which the robot is vertically cross-sectioned in a vertical plane. A robot upper arm 34 is pivotally attached to a joint 36 at an upper end region of the robot body 30, and the joint 36 can rotate integrally with the robot upper arm 34. The cylindrical body 38 is provided as an integral structure. The cylindrical body 38 is equipped with a drive motor and a speed reducer, which form a rotational drive source of the robot upper arm 34 (not shown), in a region protruding to the outside of the robot body, and bolts 39a and 39b for fixing them are installed. I can see it. The upper end 40a of the cable track 40, which is a flexible cable support member, is fixed to the cylindrical body 38 corresponding to the rotation of the robot upper arm 34 using a fixing metal fitting 42, and the lower end 40b is a clamp metal fitting 44. The robot body 30 is fastened in place.

The length of the cable track 40 has a floating length selected and set in accordance with the rotation angle of the robot upper arm 34, and is secured inside the robot body 30, as is clear from the above-mentioned principle explanation. The inside of the cable operation chamber 32 is allowed to float up and down. And, the cable 46, which is laid from the robot upper arm 34 toward the robot forearm at the tip and the robot wrist, is stored and laid inside the cable track 40, which is exactly the same as the cable processing device according to the above-described principle structure. Is.

According to the cable processing device thus constructed, when the robot upper arm 34 is rotated in the counterclockwise direction shown by the arrow R1 in FIG. 4 from the state and position shown in FIG. 3, as shown in FIG. The cable track 40 is wound on the cable winding surface on the outer circumference of the cylindrical body 38, at this time, the cable 46 is also wound on the outer circumference of the cylindrical body 38, and the cable tip exits from the tip 40a of the cable track 40.
Further, it is laid inside the robot upper arm 34 in front.

On the other hand, in FIG. 5, when the robot arm 34 and the cylindrical body 38 are rotated clockwise from the state and position shown in FIG. 3 by the arrow R2, the cable track 40 is wound around the outer circumference of the cylindrical body 38. It is unwound from the surface and floats downward toward the inside of the cable working chamber 32 formed below the robot body 30. At this time, the cable 46 is also unwound from the winding surface of the cylindrical body 38 and hangs down inside the cable working chamber 32. Also in this case, since the cable 46 is supported by the cable track 40, no load is applied due to the movement of the cable track 40. Therefore, there is a risk that the cable 46 may be damaged or broken. There is no.

Moreover, the rotation of the robot arm 34 and the cylindrical body 38 is not affected by the winding and unwinding of the cable 46 and the cable track 46 which is a supporting member thereof, and the cable track 40 and the cable contained therein are preliminarily obtained. If the floating length of 46 is secured to a sufficient length in accordance with the rotation angle, a large rotation angle exceeding 360 ° can be set.

Further, the cable track 40 is provided as a mounting seat means for a drive motor and a speed reducer at a joint portion provided at the same horizontal axis of the articulated industrial robot without passing through the central axis of the joint portion. Since the cable laying process is achieved by the structure that passes through the periphery of the cylindrical body, the constraint that the cable route must be secured in the robot body or in the center of the joint is released. As a result, the cable processing device according to the present invention can be applied to various industrial robots including an articulated robot without being restricted by the internal structure of the robot body.

[0030]

As is apparent from the above-described principle of the present invention and the description of the specific embodiments, according to the present invention, two robot constituent members that relatively rotate about a horizontal axis in an industrial robot. In a device for processing a cable extended to a joint, a tubular body that is integrally rotatable with a rotating member side of the above two members and is rotatable around the horizontal axis, and a tip end thereof is fixed to the tubular body. , The other end is fixed to the non-rotating member side of the two members and has a predetermined floating length,
A flexible cable supporting member for storing a cable, which is arranged so as to be wound around and rewound around the cylindrical body in accordance with the rotation of the cylindrical body, and a floating portion of the flexible cable supporting member which is secured on the non-rotating member side. A cable processing device is provided in a joint part of an industrial robot having a cable working chamber that forms a volume area capable of receiving a cable. Therefore, the cable processing device is applied to a joint part of a robot arm or a robot wrist. Thus, the rotation angle of the robot arm or the wrist of the robot can be set to one rotation (360 °) or more than this without being restricted by cable processing. As a result, the rotation angle of the industrial robot can be increased. It is possible to improve the work function.

Moreover, since there is no fear that an unreasonable load is applied to the cable track as the cable supporting member or the cable itself, the effect of extending the service life of the cable can be obtained. Further, the cable track that constitutes the cable support member is a robot component that can be obtained relatively easily, and in many cases, the cylinder body provided in the joint portion is equipped with a drive motor or a speed reducer at the joint portion of the robot. Since the winding means of the cable track can be formed by using the cylindrical body provided as the mounting seat means in combination, the effect of avoiding the cost increase due to the improvement of the cable processing means can be obtained, and thus the manufacturing cost of the industrial robot and the A reduction in function maintenance cost can be achieved.

[Brief description of drawings]

1 (a) and 1 (b) are a schematic front view and a side view as seen from a line 1-1 of FIG. 1, showing a principle of a configuration of a cable processing device in a joint portion of an industrial robot according to the present invention. .

2 (a) and 2 (b) are the same front views as FIG. 1 (a), respectively, for explaining the operating principle of the cable track accompanying the rotation of the rotating body side of the robot body and the rotation of the cylindrical body. is there.

FIG. 3 is a front sectional view showing a specific example of the cable processing device in the joint portion of the industrial robot according to the present invention.

FIG. 4 is a front view similar to FIG. 3, showing a state of a cable track which is displaced in response to rotation of a rotating member side of a robot body and a cylindrical body having a cable winding surface.

5 is a front view similar to FIG. 3, showing a state of a cable track that is displaced in response to rotation of a rotating member side of a robot body and a cylindrical body having a cable winding surface.

FIG. 6 is a partial schematic cross-sectional view showing an example of a cable processing device in a joint portion having a horizontal central axis of a conventional industrial robot.

FIG. 7 is a partial schematic cross-sectional view showing an example of a cable processing device in a joint portion having a horizontal central axis of a conventional industrial robot.

[Explanation of symbols]

 12 ... Robot body 14 ... Robot arm 16 ... Cylindrical body 20 ... Cable track 26 ... Cable 30 ... Robot body 32 ... Cable track working room 34 ... Robot arm 38 ... Cylindrical body 40 ... Cable track 46 ... Cable

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Okada 3580 Furubaba, Oshinomura, Minamitsuru-gun, Yamanashi Prefecture Within FANUC Co., Ltd. Address within FANUC CORPORATION

Claims (1)

[Claims] 1. An apparatus for processing a cable extending to a joint of two robot constituent members that rotate relative to each other around a horizontal axis in an industrial robot, wherein the horizontal axis is integrated with a rotating member side of the two members. A tubular body rotatably provided around the tubular body, the tip of which is fastened to the tubular body, the other end of which is fastened to the non-rotating member side of the two members, and which has a predetermined floating length; A flexible cable support member for storing a cable, which is arranged so that it can be rolled up and rewound around the body according to the rotation of the body, and a floating portion of the flexible cable support member that is secured on the non-rotating member side. A cable processing device in a joint part of an industrial robot, comprising: a cable operation chamber that forms a possible volume region.