JPS58171279A - Industrial robot - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an industrial robot that appropriately controls the position of a moving member that supports an operating element.

Generally, in industrial robots, the robot is operated by operating a microcomputer based on numerical data or input data by teaching increase, or the robot is operated by a fixed electrical sequence control device. By the way, if an obstacle is mistakenly placed in the operating area of the robot, for example, the operating element may come into contact with the obstacle, causing damage to the operating element or the movable member that supports the operating element. Therefore, there has been a demand for a mouth-use kit equipped with safety devices to prevent damage to various parts.

Moreover, the external force acting on the operating element is not always limited to one direction, so even when an external force acts on the operating element in an unspecified direction, it is necessary to prevent the operating element from being damaged. It is necessary to release the force in the direction of the external force. As a robot of this type, a robot equipped with a safety device having the structure shown in FIGS. 1 and 2 has been proposed. That is, a spherical concave body 51 and a spherical convex body 52 are provided at the tip opening of the movable member 11' whose position is appropriately controlled.
A spherical bearing 53 is provided, and an operating element 24', for example a welding torch, is disposed through the perforated hole 54 of this spherical convex body 52, and the welding torch 24' is moved to Z by a spring 55.
The welding torch was configured to be biased in two directions so that it could be tilted and moved in the z1 direction. Further, a fixed electrode 57 having an arcuate shape is attached to the rear end opening of the movable member 11' via an insulating material 56, and a first movable electrode radially shaped is attached to the tail end of the welding torch where the fixed electrode 57 is located. 58.58...-
and a second movable electrode 59 extending in the radial direction are attached, and the contact state of the welding torch is detected by the movable electrode 58.59, the fixed electrode 57, and a detector 60.60 connected to these.

That is, for example, when a force in the X direction or Y direction is applied to the tip of the welding torch, the welding torch rotates around the spherical bearing, and the first movable electrode and the fixed electrode come into contact with each other.

In addition, when a force in the Z-direction is applied to the tip of the welding torch, the welding torch that penetrates the hole in the spherical convex body moves in the Z-direction against the spring and is fixed to the second movable electrode. Contact with the electrode.

In this way, the welding torch is displaced in the direction of the external force,
Since the contact state of the welding torch is detected by the contact between the movable electrode and the fixed electrode, the amount of displacement of the welding torch with respect to the moving member is limited to an extremely small value. In other words, if the amount of displacement of the welding torch increases, the movable electrode may be pressed against the fixed member more than necessary, or the tail end of the welding torch may come into contact with the moving member, resulting in damage to the movable electrode or the welding torch. . In addition, in order to tilt the spherical convex body smoothly in the spherical bearing, the spherical convex body and the spherical concave body must be machined with high precision. In order to hold the spherical concave body, it is necessary to divide the spherical concave body into at least two parts in the radial or axial direction, but the work of forming the inner surface of the divided spherical concave body into a smooth spherical shape is troublesome. Ta. Furthermore, when an external force in 21 directions is applied to the tip of the welding torch, the positioning of the welding torch, that is, the operating element, can be made easier by making the hole in the spherical convex body larger in order to allow the welding torch to move smoothly. It had the disadvantage of being inaccurate.

An object of the present invention is to provide an industrial robot that eliminates the above-mentioned conventional drawbacks.

Hereinafter, the present invention will be described in detail with reference to illustrated embodiments. Now, to talk about the multi-joint arm type industrial robot, in Figs. 5 is a rear arm rotatably supported by the link lever 4, and 6 is an upper arm rotatably supported by the lower arm 3 and the rear arm 5, respectively. The upper arm 6, lower arm 3, link lever 4, and rear arm 5 form a parallel link mechanism. A moving member 11 is supported at the end of the upper arm 6 directly or indirectly via a suitable drive mechanism.

7 and 8 are first and second rotary drive machines supported by the underframe l, and the lower arm 3 is connected to the first rotary drive machine 7 via a reducer.
The upper arm 6 is rotated in the vertical direction by the lower arm 3 and the upper arm 6 via the link lever 4 and the rear arm 5, which are rotated by the second rotary drive machine 8 via the reducer. Rotates vertically. Further, the underframe 1 is rotated in the horizontal direction by a third rotary drive machine 9 via a reduction gear.

In the illustrated case, the moving member 11 is, for example, a horizontal rotation mechanism 10.
The movable member 11 is supported on the arm 6 by means of which a suitable operating element 24, for example a welding torch with a consumable electrode, is supported. More specifically, in FIGS. 4 and 5, reference numeral 12 designates a first movable member that supports an operating element 24, for example a welding torch, at one end; in the illustrated case, the welding torch 24 is attached to the first movable member 12. It is screwed on.

A through hole 121 is formed in the substantially axial center of the first moving member 12, and a disk-shaped bulge 122 that protrudes in the radial direction is formed at the end in the z1 direction. Note that the bulging portion 122
The outer surface is formed into a spherical convex shape 123. 13
A second moving member for supporting the first moving member 12 is formed with a bottomed portion 131 and a cylindrical portion 132. Further, a through hole 133 is bored in the bottomed portion 131, and the bulging portion 122 of the first moving member 12 is accommodated in the cylindrical portion 132 of the second moving member 13 through the through hole 133. Then, the seven-run surface 124 of the bulging portion 122 comes into contact with the bottomed portion 131 of the second moving member 13 . Note that the bulge 12
Since the curvature of the second spherical convex portion 123 is formed to be approximately the same as the radius of the cylindrical portion 132, the first moving member 12
It can freely tilt and slide with respect to the moving member 13.

Reference numeral 14 denotes a spring holder that locks the compression spring 19, and the compression spring 19 disposed between the spring holder 14 and the first moving member 12 always biases the first moving member 12 in the Z2 direction. has been done. Reference numeral 15 denotes a lid body, and this lid body 15 and a spring presser 14 are integrally fastened to the second moving member 13, and are connected to the support bracket 1 via a suitable electrically insulating member 16.
7 and connected to a horizontal rotation mechanism 10. The moving member 11 is constituted by the above 12 to 17.

Reference numeral 18 denotes a piece disposed so as to be movable in the Z direction approximately on the axis of the spring presser 14, and in the illustrated case, seven rungs 18
It is formed into a cylindrical shape with 1.

Reference numeral 20 denotes a compression spring disposed between the lid 15 and the piece 18. Due to the force of this spring, the piece 18 is always urged in the Z2 direction and comes into contact with the first moving member 12i.

Reference numeral 21 designates a flexible guide disposed between the lid 15 and the welding torch 24, and is made of, for example, a spirally formed wire rod with a circular or non-circular cross section, or a resin tube. In addition, in the case of illustration, the threaded part 1 screwed on the lid body 15
An end of a flexible conduit tube (not shown) for guiding the consumable electrode wire is screwed onto 51. Further, 22 is a connection port for supplying the shielding gas of the m-contact, and a space communicating with this connection port 22 is provided with an appropriate airtight member 2.
31. Blocked by 232, 233, 234, piece 18
It communicates with the welding torch 24 through holes 182 bored at the ends in 12 directions. A detector 25 is arranged to detect, for example, the position of the seventh rung portion 181 of the piece 18. 26 is a cover having appropriate flexibility such as made of rubber or synthetic resin, and 27 is a power line for welding. After being supported on, for example, the lid 15 via an appropriate insulating member,
Connected to a welding torch.

In the above configuration, while controlling the position of the movable member 11 appropriately, the shielding gas supplied from the connection port 22 is supplied to the piece 18 when the welding torch comes into contact with the bottomed part 131 of the workpiece 13. The welding torch 24 is reached through the lower part. Further, a consumable electrode wire (not shown) is guided by a flexible guide 21 and fed to a welding position, and welding is performed while power is supplied to a welding torch via a power line 27.

A case will be described in which an external force is applied to the tip of the welding torch during operation of the industrial robot, that is, during welding or non-welding. 6 to 8, FIG. 6 is a state diagram when no external force is applied to the welding torch, and in this state, it is assumed that, for example, an external force in the x1 direction is applied to the tip of the welding torch. The curvature of the curved convex portion 123 of the bulging portion 122 of the first moving member 12 is the same as that of the cylindrical portion 1 of the second moving member 13.
32, the first moving member 12 tends to tilt counterclockwise. in this case,
The first moving member 12 is biased in the Z2 direction by the spring 19, and the flange surface 124 of the bulging portion 122 tilts with respect to the bottomed portion 131 of the second moving member 13. In this case, the seventh
As shown in the figure, the piece 18 is moved by a distance ΔZ2 in the Z1 direction. Further, when an external force in the z1 direction is applied to the tip of the welding torch, the bulging part 122 of the first moving member 12 moves in the z1 direction along the cylindrical part 132, as shown in FIG.
direction, for example, by a distance of Δz3.

In addition, since the bulging part of the first moving member 12 is formed in a spherical convex shape, the first moving member 12 is connected to the second moving member 1.
It can be tilted in any direction with respect to 3, and the force 1 and the bulge gl<122 are formed in a disk shape,
Since the contact surface of the piece 18 that constantly contacts this disk-shaped bulge 122 is formed in a cylindrical shape, the piece 18 moves in the Z1 direction regardless of the tilting direction of the first moving member 12. . That is, as shown in FIG. 7, the center point of the ball is Z1 by Δz1.
When the first moving member 12 is tilted so as to be displaced in the direction, the piece 18 moves in the Z1 direction by ΔZ2 regardless of the tilting direction.

When an external force acts on the tip of the welding torch in this way,
Regardless of the direction of action of the external force, the piece moves in a constant direction, i.e. Z1.
By appropriately selecting the output state of the detector that detects the position of this piece, it is possible to detect an abnormal state of the welding torch in any direction with a single detector.

Furthermore, the free passage between the first moving member 12 and the perforation hole 133 of the second moving member 13 and the free passage in the two directions of the piece 18 and the first moving member 12 can be appropriately selected. Even if an impact force is applied to the tip of the welding torch, the welding torch, the first moving member, etc. can be freely displaced in the direction of the external force with respect to other members, and there is no risk of damage to each part. . Note that FIGS. 9 and 10 are detailed views corresponding to FIGS. 7 and 8, respectively, but as shown in the figures, even if the welding torch etc. is appropriately displaced by external force, the consumable electrode wire (not shown) Since the consumable electrode wire is guided by a flexible guide, it does not come into contact with other parts, so when the external force acting on the welding torch is removed, the welding torch returns to the initial state shown in Figure 4. automatically returns to. Of course, if an abnormal state of the welding torch is detected, the abnormality signal can be used to interrupt the welding operation or other operations related to the welding operation, or to display an abnormality alarm.

FIG. 11 is a diagram showing essential parts of another embodiment of the present invention, and shows a case where the axes of the operating element 24 and the first moving member 12 do not coincide with each other.

FIG. 12 is a diagram showing a main part of still another embodiment of the present invention, in which the bulging portion 122 of the first moving member 12 is formed into a 1/2 spherical convex portion. Further, the bottomed portion 131 of the second moving member 13 is formed into a 172 spherical concave portion continuous to the cylindrical portion 132. The piece l, which is movable in the Z direction within the cylindrical portion of the second moving member 13, is formed in a cylindrical shape, and a detector is formed on a part of the taper formed on the inner circumferential surface of the upper end of this piece 18.
For example, the contact of the limit switch 25 comes into contact with it. If formed in this way, it is possible to form, for example, an axial groove in the cylindrical portion 132 of the piece 18 in the cylindrical portion 132 so as to be restrained against the piece.

In addition, 28 is an air vent in the second moving member 13, and the movement of the first moving member 12 and the piece 18 is performed smoothly.

Figure $13 is a diagram showing the main parts of another embodiment of the present invention, in which the bulging part 122 of the first moving member 12, the bottomed part 131 and the cylindrical part 132 of the second moving member 13, is the same as shown in FIG. Furthermore, the first moving member 1
2 is formed with a protrusion 125 having a larger diameter than the second moving member 13, and the lower end of the cylindrical piece 18, which is guided by the second moving member 13 and is movable in the axial direction, is connected to the lower end of the first moving member. Projection part 12
5 are in contact with each other.

FIG. 14 and FIG. 15 are diagrams showing main parts of other embodiments of the present invention, respectively, and what is shown in FIG.
The bulging portion 122 of the movable member 12 has a convex outer periphery 1 in the shape of a mountain height.
23 is formed. Moreover, in the one shown in FIG. 15, a flange-like outer circumferential convex shape 123 is formed on the bulged portion 122 of the first moving member 12. The outer diameter of these raised and flange-shaped outer circumferential convex portions 123 is formed to be slightly smaller than the inner diameter of the circumferential portion 132 of the second moving member 13 . Furthermore, as shown in FIG. 15, the piece 18 is formed in a cylindrical shape, and a rod 291 of a cylinder 29 operated by pressure fluid is connected to the piece 18.
is always biased in the Z2 direction. In this case, if a gas such as compressed air or compressed gas is used as the pressure fluid, relatively small pressure adjustments can be made finely.Moreover, when an impact force is applied to the fluid pressure operated cylinder via the bridge, , is preferable because the shock can be absorbed by the pressure gas part.

As mentioned above, if the detector is disposed as shown in FIGS. 4, 12, and 15, there is no risk of the detector being damaged by contact with other members. Figure 4 and 1
If the movable part and the piece of the first moving member are housed in the cylindrical part of the second moving member as shown in FIG. and smooth movement of pieces is maintained. Figures 4 and 11
If the bulge portion of the first movable member is formed as shown in FIGS. 12 and 13, the welding torch and the first movable member can be smoothly tilted and slid. Figure 4,
11, 14, and 15, manufacturing is easy. If the first movable member is provided with a large-diameter protrusion 125 as shown in FIG. 13, the displacement of the piece moved when the first movable member is tilted will be magnified, making it possible to detect minute tilting conditions. I can do it. By arranging the detector so that it can be operated from the outside as shown in FIGS. 11 and 13, the detection state can be finely adjusted. Although it is generally inexpensive to use a spring member as the biasing means, it is also possible to construct the structure as shown in FIG. 15, or to use a magnet as the biasing means.

Note that when the operating element and the moving member j81 have a large weight, the weight can be regarded as a biasing means. As shown in FIG. 4, it is suitable as a husband robot for operating elements such as a welding torch and the bulge of the first moving member. Note that, as shown in FIG. 11, the operating elements, for example, the welding torch and the bulging portion of the first moving member may be arranged so that their axes do not coincide with each other. In this case, there is an advantage that the height from the free end of the operating element to the moving member can be reduced.

In the above description, an appropriate contact type or non-contact type detector such as a differential transformer, an optical sensor, a magnetic sensor, etc. can be used as the detector. In addition to the welding torch, a spray gun for painting, an assembly tool, a gripping tool, etc. can be appropriately selected as operating elements. Note that the present invention can also be applied to an appropriate robot such as a cylindrical coordinate system or a rectangular coordinate system.

Note that the present invention is not limited to the above embodiments,
Various modifications can be made by replacing each part of the embodiment with an equivalent member or by appropriately combining each part of the embodiment.

As described above, according to the present invention, the operating element is supported so as not to shift during the operation of the robot, so that the desired work can be performed, and the operating element can freely tilt and slide relative to the movable member. Therefore, when an external force is applied to the operating element due to an unexpected factor, the operating element can be freely displaced in the direction in which the external force is applied.Therefore, there is no risk of damage to each part. An abnormal state can be detected with a single detector regardless of the direction of action of the Since the robots are positioned relative to each other with high precision by the means, the robot can perform the desired work.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view showing the main parts of the conventional example, FIG. 2 is a sectional view taken along the line Tl-1 in FIG. 1, FIG. 3 is a perspective view showing the embodiment of the present invention, and FIG. 5 is a side view of FIG. 4, FIG. 6 is a schematic diagram of the main part of FIG. 4, and FIG.
8 and 8 are state explanatory diagrams of FIG. 6, and FIG. 7 is a diagram when a horizontal external force is applied to the first moving member, and FIG.
The figure is a diagram when a vertically upward external force is applied to the first moving member, and FIGS. 9 and 10 are explanatory diagrams of the state of FIG. 4.
Figures corresponding to FIGS. 7 and 8, respectively, and FIGS. 11 to 15 are front sectional views showing essential parts of other embodiments of the present invention. 11... Moving member, 12... First moving member, 12
2...Bulging part, 123...Convex part, 13...Second
131... Bottomed part, 132... Cylindrical part, 18... Piece, 24... Operating element, 25... Detector. Agent: Patent attorney Hirotoshi Nakai) Engraving of the drawings (no changes to the content) Fig. 1 2 Y2-7-Yl Fig. 4 Fig. 5 x 2←-r, distance 1-L, y2 No. 9
Figure Figure 10, Figure 1.1 Figure 12 Industrial robot 3, relationship with the amended person case Patent applicant: 2-1-11 Tayo, Yodoyo-ku, Osaka (026) Osaka Transformer Co., Ltd. 4, agent address: Yodoyo, Osaka 532 Kutayo 2-1-1
No. 1 No. 5, Date of amendment order Voluntary

Claims (1)

[Scope of Claims] 1. An industrial robot that appropriately controls the position of a movable member consisting of a first movable member that supports an operating element and a second movable member that supports the first movable member. The second moving member is formed into a cylinder with a bottom, and the bottomed part faces the axial rectangular part and the cylindrical part of the cylinder, so that the first moving member moves in the axial direction and the axis of the second moving member. A bulge is formed at the free end of the first movable member so that the first movable member is movable in a direction in which it tilts, and the first movable bulge comes into contact with a bottomed portion of the second movable member. A detector that is provided with biasing means for blindly biasing and outputs an abnormal signal when the first moving member is displaced by a predetermined amount or more with respect to the second moving member against the biasing force of the biasing means. An industrial robot equipped with The bulge portion of the first movable member is formed in contact with the flat portion that abuts the bottomed portion, and the second movable portion is in contact with the bottomed portion. The industrial robot according to claim 1, comprising a head inscribed in a cylinder of an ILIJ member. 3. The industrial robot according to claim 2, wherein the head is formed in a spherical shape inscribed in the cylinder of the second moving member. 4. The bottomed portion of the second moving member is formed as a 1/2 spherical recess connected to the cylinder, and the bulging portion of the first moving member is formed as a 1/2 spherical recess that abuts on the bottomed portion. The industrial robot according to claim 1, which is formed into a spherical convex portion. 5. The biasing means includes at least an operating element and a first
The industrial robot according to any one of claims m1 to 4, wherein the weight of the moving member is the weight of the moving member. 6. The industrial robot according to any one of claims 1 to 4, wherein the urging means is constituted by a spring member. 7. The industrial robot according to any one of claims 1 to 4, wherein the urging means is constituted by a pressure fluid actuated cylinder. 8. The industrial robot according to claim 7, wherein the urging means is constituted by a pressurized gas actuated cylinder. 9. The industrial robot according to any one of claims 1 to 4, wherein the urging means is constituted by an electromagnet. 10. An industrial robot that appropriately controls the position of a movable member consisting of a first movable member that supports an operating element and a second movable member that supports the first movable member, including a second movable member. It is formed into a bottom-shaped cylinder, and a hole is bored through the bottomed part in the axial direction of the cylinder, and the free end of the first moving member is inserted through the through-hole of at least the second moving member. A bulge is provided at the free end of the first movable member so that the first movable member is movable in the axial direction of the second movable member and in the direction tilted relative to the axis, facing the bottomed portion and the cylindrical portion. and a biasing means that contacts the free end of the first movable member to bias the second movable member in a circular manner, and the first movable member An industrial robot provided with a detector that detects the position of the piece and outputs an abnormal signal when the piece is displaced by a predetermined amount or more with respect to a second moving member against a force. 11. The bottomed portion of the second moving member is formed into a planar shape, and the bulging portion of the first moving member is formed between the planar portion that abuts the bottomed portion and the cylindrical portion of the second moving member. 11. The industrial robot according to claim 10, comprising a head inscribed in a head. 12. The industrial robot according to claim 11, wherein the head is formed in a spherical shape inscribed in the cylinder of the second moving member. 13. The bottomed portion of the second moving member is formed as a 1/2 spherical recess connected to the cylinder, and the bulging portion of the first moving member is formed as a 1/2 spherical concave portion that abuts the bottomed portion. The industrial robot according to claim @10, which is formed into a spherical convex portion. 14. The biasing means includes at least the operating element and the first
The industrial robot according to any one of claims 10 to 13, wherein the weight of the moving member is the own weight of the moving member. 15. The industrial robot according to any one of claims 10 to 13, wherein the biasing means is constituted by a spring member. 16. The industrial robot according to any one of claims 10 to 13, wherein the urging means is constituted by a pressure fluid actuated cylinder. 17. The industrial robot according to claim 16, wherein the urging means is constituted by a pressure gas actuated cylinder. 18. The industrial robot according to any one of claims 10 to 13, wherein the urging means is constituted by an electromagnet. 19. The industrial robot according to any one of claims 1J10 to 18, wherein the piece is arranged substantially coaxially with the cylinder of the second moving member. 20. The industrial robot according to claim 19, wherein the piece is formed in a cylindrical shape.