JPH0866885A - Mounting structure of grip part of robot - Google Patents

Abstract

PURPOSE: To enable workpieces to be smoothly handled without being exerted with unreasonable force even if the size and shape of the workpieces fluctuate by providing a reciprocating cylinder which moves a moving metal fitting for adjustment of the interval between the moving and fixed metal fittings. CONSTITUTION: A workpiece 1 is lowered to abut to a mounting surface. The workpiece 1 is further lowered at the proper speed, by means of a reaction force exerted from the mounting surface, to a position where it will push a moving metal fitting 6 upward. When the interval between the moving metal fitting 6 and a fixed metal fitting 7 is reduced with the moving metal fitting 6 pushed up and a preset operating position of a sensor 73 is reached, a fall stop signal is transmitted from the sensor 73 to the robot. On receiving the fall stop signal, the robot immediately stops the lowering action and undoes gripping by grips 2, completing the placing operation for the workpiece 1. Thus an interval is secured between the moving metal fitting 6 and the fixed metal fitting 7 as a tolerance to readily absorb fluctuations in the size and shape of the workpiece 1 in the vertical direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot gripping portion when gripping a work or when releasing the grip.
The present invention relates to a gripping part mounting structure for a robot that can smoothly operate without exerting an unreasonable force even if the work changes in size and shape.

[0002]

2. Description of the Related Art In order to improve the operating rate of robots,
A tool or work that is attached to the work side of the robot
Various devices have been developed for automatically exchanging the gripping metal for gripping the grip. As one of them, there is a device described in Japanese Utility Model Application Laid-Open No. 3-19684 filed by the applicant of the present application. The automatic tip fitting changing device for a robot described in the publication has a locking fitting having the tip fitting fixed to one end, and an exchange tool for attaching and detaching the fitting, and the locking fitting is provided on the other end side with a taper pin. A reciprocating cylinder having a hole, the other side of which is connected to the mounting portion of the robot body, has a resilient member biased to the taper pin side, and which reciprocates the taper pin by fluid pressure. ,
It has a reciprocating cylinder that strikes the tip of the taper pin, and a reciprocating cylinder that strikes the other end of the locking fitting.

[0003]

In the teaching type robot having the above-mentioned automatic tip fitting changing device, when the work for aligning and placing the work in the pallet is carried out, the work is carried out. The releasing position is accurately positioned by teaching. However, there are variations in the dimensions of the work, for example, the master used for teaching.
If the work is larger than the work, the work will come into strong contact with the bottom surface of the pallet, and the robot may stop due to an overload. On the other hand, if the work is small, the work will be released and the distance it will fall will be large, so the work will be dented, or the work will tip over or become misaligned after it falls, causing the next work to fall. When the robots are placed, the works come into contact with each other, and the robot has an emergency stop as in the above case.

As a countermeasure against these problems, there is a work handling metal fitting constituted by a gripping metal fitting, a tip metal fitting or the like of the robot and equipped with a touch sensor. However, since this sensor has a narrow operating range, it is necessary to slow down the operation speed of the robot immediately before the touch in order to stop the robot.
That is, when the operation speed is fast, there is a problem that the robot runs idle due to inertia and presses the work before the robot stops by the signal of the touch sensor, and the robot is overloaded. . Although the robot is provided with an overload prevention means, the overload detection works before the robot stops, and the robot enters an emergency stop state.
There is a problem that it takes time to restore the emergency stop. Further, when a work having a large dimensional variation is handled, it is necessary to slow down the operation speed from a position very near, which is not preferable because it leads to extension of the cycle.

There is also a structure such as a flexible hand that mechanically absorbs impact, but it can be used only for a work that is hard to make a dent, and the structure becomes complicated and the cost becomes high. There is a problem.

Further, in an automatic exchange device using a touch type sensor or a flexible hand, it is necessary to add a function for attaching / detaching an electric connection terminal or the like to the work handling fitting, which is also expensive.

[0007] As another measure, the work is put on the pallet side.
There is also a method of using a jig for preventing falling and shock absorption,
The jig cost becomes high and it is not an effective means.

The present invention solves the above-mentioned problems, and its purpose is to easily absorb the dimensional fluctuation of the work, detect the time when the work is released, and further to detect the work of the robot. -Providing a robot gripping part mounting structure capable of improving the operating rate of the robot by easily attaching and detaching the handling metal fittings.

[0009]

According to a first aspect of the present invention, there is provided a holding part mounting structure for a robot, wherein a guide rod is projected to one side, and the other side is connected to a mounting part of a robot body, and a guide rod. A movable metal fitting having a hole that is inserted and guided and is movable in the guided direction, and a movable metal fitting that is connected to a gripping metal fitting through a tip metal fitting, a locking metal fitting, and a replacement metal fitting, and a moving metal fitting. It has a reciprocating cylinder that adjusts the distance between the moving metal fitting and the fixed metal fitting by a sensor, and a sensor that detects the distance between the moving metal fitting and the fixed metal fitting. The signal controls the descending position of the grip and the grip or release.

The robot gripping part mounting structure of the second invention is as follows.
The guide rod and the auxiliary rod are projected to one side, the other side is connected to the mounting portion of the robot body, and the fixing metal fitting and the guide rod and the auxiliary rod are respectively fitted with holes to be guided. And a reciprocating cylinder that adjusts the distance between the moving metal fitting and the fixed metal fitting by moving the moving metal fitting and the moving metal fitting that connects the gripping metal fitting through the tip metal fitting, the locking metal fitting, and the replacement metal fitting. And a sensor for detecting the distance between the moving metal fitting and the fixed metal fitting, the movement of the moving metal fitting absorbs the dimensional variation of the work, and the sensor position controls the lowering position of the gripping metal fitting and gripping or releasing. .

The structure for mounting the grip portion of the robot of the third invention is as follows.
The tip of the rod of the reciprocating cylinder of the first invention or the second invention is fixed to a fixing member.

The gripping part mounting structure of the robot of the fourth invention is
The reciprocating cylinder of the first to third inventions has a mechanism for fixing the movement of the movable fitting by fixing its rod at an arbitrary position.

The structure for attaching the grip portion of the robot of the fifth invention is
A mechanism for fixing the movement of the moving fitting is provided at the fitting portion between the auxiliary rod of the second invention to the fourth invention and the hole of the moving fitting guided by the auxiliary rod.

The structure for attaching the grip portion of the robot of the sixth invention is as follows.
A reciprocating cylinder that reciprocates the taper pin with a resilient member biased to the taper pin side and fluid pressure on the exchange fitting of the first to fifth inventions; and a reciprocating cylinder that strikes the tip of the taper pin. A reciprocating cylinder that strikes the protruding end of the metal fitting on the side of the metal fitting is provided, one side of the metal fitting is connected to the moving metal, and the other side is connected to the metal fitting by a taper pin.

[0015]

In the robot gripping part mounting structure of the present invention configured as described above, the reciprocating cylinder depends on the fluid pressure or the total weight of the moving fitting, the replacement fitting, the locking fitting, the tip fitting, the grip fitting, and the work. The rod is pushed out, and the movable bracket is held with the movable bracket and the fixed bracket spaced apart.

Next, the robot waits above the release position with the work down so that the guide rod is perpendicular to the mounting surface. Here, after releasing the fluid pressure of the reciprocating cylinder to the atmosphere and releasing the holding of the moving bracket, the robot pushes the moving bracket upward due to the reaction force from the mounting surface as the work contacts the mounting surface. Until it is raised, it is lowered vertically at the proper speed, that is, without damaging the work. At this time, a sensor detects that the distance between the moving metal fitting and the fixed metal fitting has contracted to a preset position, the robot is stopped from descending, and if necessary, the moving metal fitting is attached to the guide rod and / or the auxiliary rod. Then, a signal is sent to the robot to release the grip of the grip fitting.

When exchanging the entire metal fitting in which the gripping metal fitting, the tip metal fitting and the locking metal fitting are connected and integrated, another three reciprocating cylinders and taper pins provided on the replacement metal fitting are used. Attach and detach it at the stopper.

[0018]

Embodiments of the present invention will be described in more detail with reference to the drawings. FIG. 1 is a cross-sectional view of a robot gripping part mounting structure of the present invention in a state where a rod of a reciprocating cylinder is pushed out and a gap between a moving metal fitting and a fixed metal fitting is opened, and FIG. 3 and 4 are side views of FIG. 1, showing only the guide rod hole and the mounting portion of the reciprocating cylinder in cross section, and FIG. 4 is a side view of the reciprocating cylinder with the rod contracted, and FIG. FIG. 7 is a cross-sectional view illustrating a mechanism for fixing the movement of the movable metal fitting in the auxiliary rod and the sliding fitting hole portion thereof.

In these figures, the work 1 shown by an imaginary line is held by the holding metal fitting 2. The robot gripping part mounting structure of the present invention has a tip fitting 3 having the grip fitting 2 attached to the lower end side, and a locking fitting 4 having the tip fitting 3 attached to the lower end side.
And a metal fitting 6 for attaching and detaching the locking metal fitting 4, a metal fitting 6 which is fixed to the metal fitting 5 and is movable up and down, and a movable metal fitting 6 which is arranged to face the metal fitting 6 and whose upper side is shown by a virtual line. It comprises a fixing metal fitting 7 connected to the mounting portion 9.

The locking metal fitting 4 has a taper pin hole in the protrusion 41 on the replacement metal fitting 5 side, and the replacement metal fitting 5 is a resilient member 51 biased to the taper pin 42 side and a taper pin by air pressure. A reciprocating cylinder A for reciprocating 42, a reciprocating cylinder B for striking the tip 43 of the taper pin 42, and a reciprocating cylinder C for striking the upper end of the locking fitting 4 are provided. The guide rod 71 protruding from the guide rod 71 is inserted and guided, the auxiliary rod 72 is also inserted and guided, and the guide rod 71 and the auxiliary rod 72 are arranged in parallel. , Moving bracket 6
And a reciprocating cylinder 8 that moves up and down, and the fixing bracket 7 includes a guide rod 71 and an auxiliary rod 72 protruding downward.
And a sensor 73 for detecting the distance between the fixed metal fitting 7 and the movable metal fitting 6.

Here, the tip 82 of the rod 81 of the reciprocating cylinder 8 can be used by fixing it to the fixture 7. By doing so, the fluid pressure applied to the rod side and the head side of the reciprocating cylinder 8 can be arbitrarily determined by the total weight from the moving metal fitting 6 to the work 1 gripped by the grip metal fitting 2 and the pneumatic circuit (not shown). Since the positions can be balanced, when the robot places the work, the reaction force when the work comes into contact with the placement surface can be reduced.

Further, the reciprocating cylinder 8 is preferably a commercially available brake cylinder capable of forcibly gripping its own rod at an arbitrary position. That is, when the robot mounts the work 1, as shown in FIG. 4, the distance between the moving metal fitting 6 and the fixed metal fitting 7 is shortened. When 1 is released, the support by the work 1 disappears, so the part from the moving metal fitting 6 to the gripping metal fitting 2 falls, and the gripping metal fitting 2 collides with the work 1 below it.
It may damage the work 1. Therefore, the work
When the work 1 is released, the rod 81 of the reciprocating cylinder 8 is fixed by a brake so that the moving metal fitting 6 does not move downward, so that the work 1 is prevented from falling and the work 1 is prevented from being damaged. It

When fluid pressure is applied to the rod side and the head side of the reciprocating cylinder 8 to balance the total weight from the movable fitting 6 to the work 1, the work 1 is released from the movable fitting 6 when the work 1 is released. On the contrary, the parts up to the gripping metal 2 impulsively move upward. Also in this case, if the rod 81 of the reciprocating cylinder 8 is braked, this movement is prevented.

Although the embodiment has been shown as an example having the auxiliary rod 72 and the auxiliary rod hole 62 which is inserted and guided, these can be omitted depending on the size and size of the robot apparatus.

In addition, the movement preventing mechanism of the moving metal fitting 6 is replaced with the reciprocating cylinder 8 with a brake, as shown in FIG. 5, in which an auxiliary rod 72 and an auxiliary rod hole 6 for fitting the auxiliary rod 72 are provided.
It may be provided in the second part. That is, a groove 74 is provided on the outer circumference of the auxiliary rod 72, an annular elastic tube 75 that expands and contracts by fluid pressure is inserted into the groove 74, and the elastic tube 75 is provided with a separate pneumatic circuit 76 to expand the blade, and the blade is blown. A mechanism may be provided.

An example of the operation of the grip portion mounting structure of the robot of the present invention having the above configuration will be described below. The tip fitting 3 and the grip fitting 2 are fixed to the locking fitting 4, and the grip fitting 2
Holds work 1. At this time, the rod 81 of the reciprocating cylinder 8 is pushed out by air pressure, or the moving metal fitting 6 is replaced by the total weight of the moving metal fitting 6, the replacement metal fitting 5, the locking metal fitting 4, the tip metal fitting 3, the gripping metal fitting 2, and the work 1. And the fixing metal fitting 7 are opened. Next, the robot
Move the work 1 down and move it just above the position where the work 1 is placed. Here, the fluid pressure of the reciprocating cylinder 8 is released to the atmosphere to release the holding of the moving metal fitting 6, but the work 1 is still held. Then descend work 1, work 1
To contact the mounting surface. Furthermore, the reaction force applied from the mounting surface causes the movable metal fitting 6 to be pushed up to a position where it is pushed upward.
Descend at an appropriate speed that does not damage K1.
When the moving metal fitting 6 is pushed up and the distance between the moving metal fitting 6 and the fixed metal fitting 7 is shortened to reach the preset operation position of the sensor 73, the sensor 73 sends a descending stop signal to the robot. Upon receiving the descending stop signal, the robot immediately stops the descending operation, releases the grip of the gripping metal fitting 2, and then the work 1
Complete the placement work.

As described above, there is a clearance as an allowance between the movable fitting 6 and the fixed fitting 7. By having this clearance, it is possible to easily absorb the variation in the dimensional shape of the work 1 in the vertical direction. . Further, by detecting the time when the work 1 is released by the sensor 73, the robot can perform a stable placement work without an emergency stop due to an overload.

When the soft work 1 sensitive to dents and the like is placed, the tip 82 of the rod 81 of the reciprocating cylinder 8 is fixed to the fixing member 7, and the rod side and head to be added to the reciprocating cylinder 8 and the head. By setting the pneumatic circuit so that the fluid pressure on the side is balanced with the total weight from the moving metal fitting 6 to the work 1 gripped by the grip metal fitting 2, it is possible to balance at any position. , Robot is work 1
The reaction force when the work 1 comes into contact with the mounting surface can be reduced.

When the locking metal fitting 4 to which the gripping metal fitting 2 and the tip metal fitting 3 are fixed is stored or replaced, the robot moves the entire metal fittings integrally connected to the storage location (not shown). Here, at the same time when the reciprocating cylinder A operates,
The reciprocating cylinder B operates and the rod 52 moves the taper pin 42.
The tip 43 of the tape is tapped, and the taper pin 42 overcomes the pressing force of the elastic member 51 and is separated from the locking metal fitting 4. Next, the reciprocating cylinder C operates and the rod 53 hits the upper end of the locking metal fitting 4 to separate the locking metal fitting 4 from the replacement metal fitting 5.

The above is the operation for removing the locking metal fitting 4.
When attaching the locking metal fitting 4, with the taper pin 42 retracted and detached, after inserting the new locking metal fitting in which the gripping metal fitting to be replaced and the tip metal fitting are connected to the replacement metal fitting 5,
The mounting operation is completed by restoring the paper pin 42 to the original position. In this way, the grip of the robot can be easily replaced.

[0031]

As described above, the robot gripping part mounting structure of the present invention can be handled even if the work size varies, and the work of placing the work by the robot can be performed. Can be performed easily and stably. Further, the work piece of the robot can be easily replaced. By these, the operating rate of the robot is remarkably improved, and it has an industrially excellent effect.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a rod of a reciprocating cylinder is pushed out and an interval between a movable fitting and a fixed fitting is opened in an embodiment of a robot gripping portion mounting structure of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

3 is a side view of FIG. 1 and is a partial cross-sectional view of only the guide rod hole and the mounting portion of the reciprocating cylinder.

FIG. 4 is a side view showing a state in which a rod of a reciprocating cylinder is contracted in the embodiment of the grip portion mounting structure of the robot of the present invention.

FIG. 5 is a cross-sectional view for explaining the mechanism of the embodiment in which the movement of the movable fitting is fixed by the auxiliary rod and its sliding fitting hole.

[Explanation of symbols]

1: Work 2: Grip metal 3:
Tip fitting 4: Locking fitting 5: Replacement fitting 6:
Moving bracket 7: Fixing bracket 8: Reciprocating cylinder 9:
Robot body mounting part 41: Projecting part 42: Taper pin 4
3: Taper pin tip 51: Elastic member 52: Rod 5
3: Rod 61: Guide rod hole 62: Auxiliary rod hole 7
1: Guide rod 72: Auxiliary rod 73: Sensor 7
4: Groove 75: Elastic tube 76: Pneumatic circuit 8
1: Rod 82: Rod tip A, B, C: Reciprocating cylinder X-
X: Cross-section position in the direction of arrow

Claims (6)

[Claims] 1. A fixing bracket having a guide rod protruding from one side and the other side connected to a mounting portion of a robot main body, and a hole into which the guide rod is fitted and guided, and moved in the guided direction. It is possible to move the metal fittings that connect the grip fittings through the tip fitting, the locking fitting, and the replacement fitting, the reciprocating cylinder that adjusts the distance between the moving fitting and the fixed fitting by moving the moving fitting, and the moving fitting. The present invention is characterized in that it has a sensor for detecting the distance from the fixed metal fitting, absorbs the dimensional fluctuation of the work by the movement of the moving metal fitting, and controls the descending position of the gripping metal and the gripping or releasing by the signal of the sensor. Robot gripping part mounting structure. 2. A fixing metal fitting in which a guide rod and an auxiliary rod are projected to one side and the other side is connected to a mounting portion of a robot main body, and a hole which is guided by inserting the guide rod and the auxiliary rod, respectively. It has a movable metal fitting that is movable in the guided direction and that connects the gripping metal fitting through the tip metal fitting, the locking metal fitting, and the replacement metal fitting, and the distance between the moving metal fitting and the fixed metal fitting by moving the moving metal fitting. It has a reciprocating cylinder that adjusts the movement of the work piece and a sensor that detects the distance between the moving fitting and the fixed fitting. The movement of the moving fitting absorbs the dimensional fluctuation of the work. Alternatively, a gripping part mounting structure for a robot characterized by controlling release. 3. The gripping part mounting structure for a robot according to claim 1, wherein the tip of the rod of the reciprocating cylinder is fixed to a fixing member. 4. The reciprocating cylinder has a mechanism for fixing the movement of the movable fitting by fixing its own rod at an arbitrary position, according to any one of claims 1 to 3. Robot gripping part mounting structure. 5. The mechanism for fixing the movement of the moving metal fitting to the fitting portion between the auxiliary rod and the hole of the moving metal fitting guided by the auxiliary rod, according to any one of claims 2 to 4. Attachment structure for the robot's grip. 6. The replacement metal fitting comprises: a resilient member biased to the taper pin side; a reciprocating cylinder for reciprocating the taper pin by fluid pressure; 6. A reciprocating cylinder for hitting an end of a metal fitting on the metal fitting side of the metal fitting, wherein one side is connected to a moving metal fitting and the other side is connected to a locking metal fitting by a taper pin. 7. A structure for mounting a grip portion of a robot according to any one of 1.