WO1985000315A1

WO1985000315A1 - Safety joint for industrial robot

Info

Publication number: WO1985000315A1
Application number: PCT/JP1984/000338
Authority: WO
Inventors: Seiichiro Nakashima; Kenichi Toyoda; Shigemi Inagaki
Original assignee: Fanuc Ltd
Priority date: 1983-06-30
Filing date: 1984-06-29
Publication date: 1985-01-31
Also published as: JPS609694A

Abstract

A safety joint (16) for connecting together a rotatable free and portion of a wrist device of an industrial robot and an operating device, such as a robot hand, a welder, or a painting machine, has a first joint base portion (18) which is secured to a free end (15) of a wrist device, and a second joint base portion (20) which is secured to an operating device (17). The first and second joint base portions (18), (20) are connected together rotatably by a shaft portion (22). The first joint base portion (18) is provided with an end plate (25) to prevent the second joint proximal portion (20) coming off. At least one shear pin (29) is employed to prevent the rotation of the second joint base portion (20) with respect to the first joint base portion (18). Breaking the shear pin (29) enables the second joint base portion (20) to rotate with respect to the first joint base portion (18).

Description

丄..-Description

Industrial mouthpiece safety fittings

Technical field

The present invention relates to a safety joint for an industrial robot, and more particularly, to a safety joint for connecting a working device such as a robot hand, a welding machine, a painting machine, or the like to a tip end of a wrist device of the industrial robot. About.

Background art

Generally, working equipment such as a robot hand, a welding machine, or a painting machine is provided at the tip or output end of the wrist arm g attached to the tip of the movable arm of an industrial robot. Installed. 2. Description of the Related Art A mouth bot has been conventionally known in which a working device is attached to the front end of a wrist device. In the case of this type of robot, when an excessive load such as a collision is applied to the work equipment, the excess load is directly transmitted to the wrist device, and thus the wrist device, the mouth-bottom arm, and the like are used. This will cause damage to the drive system and require extensive repairs.

There is known a robot having a safety joint that breaks when an external force exceeding a certain level is applied between a leading end of a wrist device and a working device.

Conventional known safety joints are screwed to the tip of the wrist device.

(1) a joint base, a second joint base screwed to the work machine, a breaking connection member for integrally connecting the first and second fitting bases, and a working device when the breaking connection member breaks The first and second joint bases are provided with a link or a further connecting member pin-connected to the first and second joint bases in order to prevent the falling. Άbo using this type of safety joint

In this case, when an excessive load is applied to the working equipment, the breaking connection member breaks, thereby protecting the wrist device, the robot arm, and the drive system thereof. However, if the rupture connection member breaks, it is necessary to remove the first and second joint bases from the wrist device and working equipment and replace the entire safety joint.

O PI 'ά-There was a drawback that the work was troublesome and the replacement parts cost zero. Also, since various stresses such as torsion and bending act on the connecting member for breaking, there is a disadvantage that setting of the breaking stress becomes difficult.

Disclosure of the invention

An object of the present invention is to provide a safety joint for an industrial port that can easily and inexpensively perform repair after breakage with minimal replacement of parts.

'' Another object of the present invention is to provide an industrial robot which can easily set a breaking stress.

To provide safety joints.

According to Honki Ming, the above-mentioned purpose was

'' Rotatable tip and robot hand, welding machine, painting machine, etc.

Safety joints for connecting

A first joint base fixed to the distal end of the wrist device;

A second joint base fixed to the work equipment,

Means for connecting the first joint base and the second joint base so that they can be cultivated;

Means for preventing separation of the second joint base from the first joint base;

'' Achieved by a safety joint of an industrial robot comprising at least one shear pin that prevents rotation of the second joint base with respect to the first joint base and breaks by a certain or more shear stress .

According to the safety joint having the above configuration according to the present invention, the second joint base can rotate with respect to the first joint base due to shearing of the shear pin due to excessive torsion moment. Therefore, the excessive torsion moment is not transmitted to the wrist device, the robot arm, and the drive device thereof, so that damage to the wrist device, the robot arm, the drive device, and the like can be prevented. Repair can be done easily and inexpensively only by replacing the shearing bin. Shear response for shear pins

ΟΜΡΙ Since only the force acts, the breaking stress of the shear pin can be easily set.

The means for rotatably connecting the first joint base and the second joint base may include a shaft fixed to the first joint base. In this case, the second joint base has a fitting hole that is rotatably fitted on the cross section.

The means for preventing detachment of the second joint base from the first joint base is fixed to the first joint base and cooperates with the first joint base in the axial direction of the second joint base. An end plate may be provided.

The rotation axis of the second joint base relative to the first joint base is forward.

It may be coaxial with the rotation axis of the tip of the wrist device. In this case, the safety joint exerts its function by irradiating torsion moment around the rotation axis of the second joint base.

Preferably, the cultivation axis of the second joint base with respect to the first joint base extends in parallel with the cultivation axis of the distal end of the wrist device, and the working equipment is the wrist device of the wrist device. It is located on the rotation axis at the tip. In this case, the safety joint exerts its function against at least two types of external forces applied to the second joint base.

Preferably, the first and second joint bases have __ through holes for inserting the shear pin. The broken shear pin can be easily removed from the through hole, and a new shear pin can be easily inserted into the through hole.

Preferably, the shear pin has a constricted portion located at the boundary between the first and second joint bases on the outer periphery. By adjusting the depth of the constriction, the breaking stress of the shear pin can be easily adjusted.

Preferably, the safety joint according to the present invention includes a detector for detecting rotation of the second joint base with respect to the i-th joint base.

OMPI .

4--Yes. The detection of the rotation of the second joint base relative to the first joint upper part, that is, the breakage of the shear pin, is detected by this inspection kagyu.

The above and other objects and features of the present invention will become apparent from the following detailed description with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view showing a cold state in which a safety joint according to a first embodiment of the present invention is applied to an articulated arm type industrial robot,

FIG. 2 is an exploded perspective view of the safety coupling shown in FIG. 1,

FIG. 3 is a sectional view showing the assembled state of the safety coupling shown in FIG. 1; FIG. 4 is an exploded perspective view of the safety coupling showing the second embodiment of the present invention; FIG. 5 and FIG. Each section of the safety joint shown in Fig. 4 is broken.

'It is a plan view.

The best form for carrying out KIKI

FIG. 1 to FIG. 3 show a first embodiment of the present invention.

Referring to FIG. 1, the articulated arm-type industrial robot has a movable upper arm 11 and a movable lower arm 12, and a lower end of the lower arm i 2 has a base for the wrist device or a lower end. The yoke 13 is provided so that it can be swelled around the central axis of the lower arm 12. At the base 13 of the wrist device, an intermediate portion 14 is provided so as to be able to perform II tilling around an axis C 1 orthogonal to the center line of the lower arm 12, and the intermediate portion 14 has a tip 15. It is provided so as to be able to till around a 周り line C 2 orthogonal to the axis C 1. The mouth bottom hand 17 is attached to the leading end 15 of the wrist device via the safety joint 16 according to the present invention. Instead of a robot hand, other working equipment such as a welding machine or a painting machine can be attached to the head part 15 of the wrist device via the safety joint 16.

Referring to FIGS. 2 and 3, the safety joint 16 has a disk-shaped first joint base 18 attached to the distal end 15 of the wrist device. The first joint base 18 has a front surface 18a and a rear surface 18b. 1st hand base on front 15a of front end 15 of wrist device

OMPI The first joint base 18 is attached to the tip 15 of the wrist device with a plurality of bolts 19 (only one bolt is (Shown).

A safety joint 16 is provided with a second joint base 20 having a disc-like shape.

The second joint base 20 has a front surface 20a and a rear surface 20b.

With the front surface 20a of the second joint base 20 abutting the rear surface 1a of the mouthboat hand 17 and the second joint base 20 with a plurality of bolts on the robot hand 17 2 1 (only one bolt is shown in Fig. 3).

The front surface 18a of the first joint base 18 is provided with a cylinder recess 22 coaxial with the rotary wire C2 of the leading portion 15 of the wrist device. The second joint base 20 is open to the rear surface 20 and a cylindrical fitting hole rotatably fitted to the 2 portion 22 of the first joint base 18.

Has 2 3 In addition, the second joint base 20 has a recess 24 that opens to the front surface 20a. The location 24 is arranged coaxially with the fitting hole 23 and has a larger inner diameter than the fitting hole 23. The fitting hole 23 opens at the bottom 24 a of the recess 24.

On the front surface of the shaft portion 22 of the first joint base 18, an end plate 25 located in the recess 24 is fixed by a bolt 26 screwed to the shaft portion 22.嬙扳 2.5 has a larger outside than the joint hole 23.

In addition, the axial length of the shaft portion 22 is the rear surface 20 b of the second joint base 20.

Slightly greater than the axial thickness between the recess 24 and the bottom 24 a of the recess 24. Therefore, between the end plate 25 and the first joint base 18, the second joint base 20 can rotate around the axis of the shaft 22, but the second joint base 20 can rotate about the axis of the shaft 22.

The joint base 20 is held between the end plate 25 and the first joint base 18 so that it cannot be separated in the axial direction. Although not shown, the shaft portion may be formed separately from the first joint base portion and integrally with the end plate. In this case, the shaft integrated with the base plate is fixed to the first joint base by a bolt.

First and second joint bases 18 and 20 extend parallel to shaft 22

OMPI b

It has holes 27 and 28 for passing through the pins. The holes 27 and 28 pass through the first and second joint bases 18 and 20 in the axial direction. In the holes 27 and 28, a shear pin or a break pin 29 is inserted. The shear pin 29 has a constricted portion 29a formed on the outer periphery. The shearing bin 29 is arranged such that the constriction 29 a is located at the boundary between the first and second joint bases 18, 20 ′. By adjusting the depth of the constricted portion 29a, the shear stress of the shear pin 29 can be easily adjusted. Although two shearing bins 29a are used in the embodiment shown in FIG. 2, at least one shearing pin 29 is sufficient.

As shown in FIG. 3, the safety joint 16 has a detector 30 for detecting the tillage of the second joint base 20 corresponding to the first joint base 18. The detector 30 includes a dog 31 fixed to the second joint base 20, and a limit switch 32 having a protrusion 33 elastically contacting the dog 31. When the second joint base 20 is fixed to the first joint base 18 by the shear pin 29, the protrusion 33 of the limit switch 32 elastically contacts the dog 31. I have. When the protrusion 33 of the limit switch 32 moves away from the dog 31, a detection signal is sent from the limit switch 32 to an alarm device (not shown) or the like. In the state where the safety joint 16 having the above configuration is assembled as shown in FIG. 9, the zero tilling of the second joint base 20 with respect to the first joint base 18 is blocked by the shear pin 29. When a torsional moment about the sensitive line C2 that exceeds the shear stress of the shear pin 29 acts on the robot hand i7, the shear pin 29 breaks at the constriction 29a, joint base 2 0 is allowed Menten around雜線C ₂ to对to the first joint body (1) 8. Therefore, damage to the wrist device, the robot arms 11, 12, and these driving devices due to the excessive torsional moment about the axis C ₂ is prevented. The rotation of the second joint base 20 with respect to the first joint base 18 causes the limit switch 3 2 . ■. Γ-.

The force of the lever 33 moves away from the dog 31, whereby the limit switch 32 emits a rotation detection signal.

Since the only stress applied to the shear bin 29 is the shear stress, the breaking stress of the shear bin 29 can be easily set.

When the shear pin 29 breaks, the second joint base 20 can rotate with respect to the first joint base '1.8, but the second joint base 20 is connected to the first joint base 18 and the plate 2. 5 keeps the 2nd joint base 20 and the mouth bolt hand 17 from dropping.

Repair is completed by simply changing the shear pin 29 of the safety joint 16. The broken shear bin 29 can be easily removed from the holes 27, 28, and a new shear pin 29 can be easily inserted into the holes 2, 28. Therefore, repair can be performed inexpensively and in a short time.

FIGS. 4 to 6 show a second embodiment of the present invention. In these figures, the same components as those in the first embodiment are denoted by the same reference numerals.

Referring to FIGS. 4 to 6, in this second embodiment, the rotation axis C ₃ of the second joint base 20 with respect to the first joint base 18 is the rotation axis C ₃ of the distal end 15 of the wrist device. It extends parallel to ₂ , and the mouth bot hand 17 is located on the cultivation line C 2. of the front part 15 of the wrist device. Instead of the robot hand, other working equipment such as a welding machine or a painting machine may be attached to the second joint base 2.0.

In the second embodiment, when an external force in the direction perpendicular to the plane relative to the axis C ₂ through vertical and轴線C 2 and C ₃ is applied to the robot Toja down de i I, C ₃ twisting around Mome Occurs. This torsion moment generates shear stress on the shear pin 29. If the shearing stress is equal to or greater than the breaking stress of the shear pin 29, the shearing bin 29 will be broken strongly, and the second joint base 20 will be aligned with the first joint base 18 with respect to the axis C3. a

Can be rotated around. When a torsion moment acts on the robot hand 17 around the axis C 2, the torsion moment is applied to the joint between the first joint base 18 and the second joint base 20. Therefore, the shear pin 29 is subjected to a shearing response due to this torsion moment. Therefore, if this shear stress is equal to or greater than the breaking stress of shear pin 29, shear pin 29 will break. Therefore, in the second embodiment, the safety joint 16 exerts its function against the two types of overstimulated external forces acting on the robot hand 17.

Although the two preferred embodiments have been described above, the present invention is not limited to only the embodiments of the above-described embodiments, and various changes may be made to the components within the scope of the invention described in the claims. Add-you can. For example, the means for operably connecting the first joint base and the second joint base may include a cylinder-shaped shaft provided on the second joint base. In this case, it is sufficient to form a fitting hole at the base of the joint so as to be able to face the sensitive portion.

Industrial applicability

INDUSTRIAL APPLICABILITY The safety joint according to the present invention can be used for safely connecting the distal end portion of a wrist device of various industrial robots to working equipment such as a mouth-bottom hand, a welding machine, a painting machine, and the like.

OMP1

Claims

The scope of the claims

1. A safety joint for connecting the rotatable tip of an industrial robot's wrist device to work equipment such as a robot, a hand, a welding machine, a paint shore, etc.

A first joint base fixed to the distal end portion of the wrist device, a second joint base fixed to the work equipment,

Means for rotatably connecting the first joint base and the second joint base;

'' Means for preventing separation of the second joint base from the first joint base;

An industrial robot safety joint comprising at least one shear bin that prevents tillage of the second joint base with respect to the first joint base and breaks by a predetermined or more shear stress.

2. The means for rotatably connecting the first joint base and the second joint base includes a shaft fixed to the first joint base, and the second joint base includes the shaft 2. The safety joint according to claim 1, wherein the safety joint has a fitting hole which is fitted so as to be capable of being cultivated.

3. The means for preventing detachment of the second joint base from the first joint base includes fixing the second joint base to the first joint base and cooperating with the first joint base. The safety joint according to claim 1 or 2, further comprising a steel plate for holding in a direction.

4. The safety joint according to claim 1, wherein a rotation axis of the second joint base with respect to the first joint base is coaxial with a rotation axis of the distal end of the wrist device.

5. The axis of rotation of the second joint base with respect to the first joint base is parallel to the rotation axis of the tip of the wrist device, and the work equipment is on the tillage axis of the tip of the wrist device. Located in The safety coupling according to claim 1, wherein the safety coupling is formed.

6. The safety joint according to claim 1, wherein the first and second joint bases have a through hole for inserting the shear pin.

7. The safety coupling according to claim 1, wherein the shearing pin has a constricted portion located on a boundary between the first and second coupling bases on an outer periphery.

8. The safety joint according to claim 1, further comprising a detector for detecting rotation of the second joint base with respect to the first joint base.