JPH0643038B2 - Work chuck attachment / detachment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention operates a chuck portion having a claw for grasping a component when the component is automatically conveyed from a certain place to another place by an industrial robot or the like. The present invention relates to a work chuck attachment / detachment device that is detachable from an arm.

(Prior Art) In order to automatically transfer a large number of parts from a stacking place to another place, the end of the work arm of the automatic transfer device must be grasped or released to release the end of the work arm. The jaws of the chuck of the section are opened by compressed air.

If there are two or more types of parts, the corresponding claws will be used, and the chuck will have two or more types. In such a case, it is necessary to replace the chuck according to the parts, and the tip base of the working arm becomes the chuck holding part, and two or more types of chucks are detachably attached to that part. There are various types in which the exchange is performed by remote control using pneumatic pressure.

An example of this is "Actual Publication No. 62-154134 (Work chuck device)", and the main part of this is as follows. In the following description, the chuck is located downward and downward, and the top and bottom are the directions in that state.

A cylinder part is formed in the upper part inside the main body fixed to the lower end of the working arm (arm), a piston is housed inside the main part, and compressed air inlets are provided on the upper and lower end sides of the cylinder part. The piston moves up and down as air is introduced and discharged.

The piston rod extending downward from the piston is made airtight in the lower part of the cylinder part of the main body, an inverted cup-shaped pin groove is formed in the lower end, and a large diameter head at the upper end of the chuck is fitted in the pin groove. Ball type detachable engagement relationship.

That is, a hole is provided in the wall in the vicinity of the lower end open portion of the inverted cup-shaped pin groove in the radial direction, and the ball is accommodated in the hole and movable in the radial direction.

The outer periphery of the piston rod and the subsequent inverted cup-shaped pin groove is slidable in close contact with the lower inner peripheral wall of the cylinder part of the main body, and is opposite to the ball when one side of the pin groove is in contact with the inner peripheral wall of the main body. The side will slightly project inward of the pin groove. Below the part where the inner peripheral wall of the main body and the pin groove are in close contact, the inner peripheral wall of the main body becomes a large diameter part with a large diameter,
When the piston moves downward and the ball in the pin groove reaches the large diameter portion, the ball can move outward.

On the other hand, a large-diameter head is formed on the upper end of the shaft-like connecting pin at the upper end of the chuck, and the lower surface thereof is a perspective surface. The lower part of the chuck has an opening / closing part for the claws, and the claws of the plurality of chucks are different, but the parts other than the claws have the same structure. The diameter of the large-diameter head portion of the chuck is the same as the inner diameter of the inverted cup-shaped pin groove, and the large-diameter head portion can freely move in and out of the pin groove.

As described above, with the chuck placed on a table, etc., the work arm is located directly above it, the piston moves downward, the pin groove is at the lowest position, and the ball is located at the large diameter part. When the work arm descends while the work arm is being held, the ball in the pin groove is pushed outward by the large-diameter head, and the ball passes through the outside of the large-diameter head of the chuck and descends. Reaches the deepest part of the pin groove. When the piston is then moved upward in that state, the pin groove rises and its outer periphery comes into close contact with the inner peripheral wall of the main body, the ball is moved inward of the pin groove, and a part of the ball To contact the slope of the large-diameter head of the chuck. As a result, the weight of the chuck is supported by the piston through the contact, and in that state, the component at the lower end of the chuck is gripped.

To remove the chuck for exchanging the chuck, move the piston downward with the chuck positioned on a table etc., and the ball in the pin groove goes down to the large diameter part, and the ball can move outward. It becomes a state. Then, when the work arm is moved upward, the chuck continues to stand still on the table due to its own weight.
The ball in the pin groove is pushed by the inclined surface of the large diameter head of the chuck and moved outward, the engagement between the ball and the large diameter head is released, and the pin groove passes outside the large diameter head. Ascends and the chuck disengages and disengages from the working arm.

In the above, the chuck is attached and detached by supplying compressed air to the upper and lower surfaces of the piston.
Safe work is performed as long as the supply of compressed air continues.

However, the supply of compressed air may stop due to a malfunction in the factory, in which case the piston will move downward due to the weight of the chuck, resulting in contact engagement between the ball and the large-diameter head. Will come off and the chuck will fall off, which is extremely dangerous.

The above-mentioned means for preventing spontaneous dropout is actually being used in various devices, and many of them utilize the action of a spring.

In the above-mentioned "work chuck device", the easiest way to prevent the chuck from falling off is to arrange a compression spring on the lower surface of the piston. Then, even if the piston descends when the compressed air is stopped, the compression spring holds the engagement between the ball at the lower end of the piston and the large-diameter head of the chuck to prevent the chuck from falling off. When removing the chuck, compressed air is introduced to the upper surface of the piston to push down the compression spring.

(Problems to be solved by the invention) While working with a device having a dropout prevention mechanism, a moving object in a factory may accidentally collide with a nail of a chuck and be deformed. In that case Is to remove the chuck after returning the chuck to its removal position.
Since the stationary state at the removal position is abnormal, the supply timing of compressed air for removal becomes irregular, and removal by compressed air becomes impossible.

Therefore, the operation is carried out by people, but since it is dangerous, the power supply and the compressed air source are shut off, and the operation must be performed in that state.

In such a case, it is necessary to manually remove the chuck. In the above case, the manual removing means may be provided as follows.

The push rod is separately fixed to the upper surface of the piston, and the upper end portion of the push rod is protruded outward from the upper end wall surface of the cylinder portion of the main body in an airtight state. With this arrangement, the chuck can be removed by pushing down the upper end of the push rod and moving the piston downward.

However, the compression spring that prevents the cap from falling directly supports the weight of the chuck, and therefore has a strength corresponding to that, so a considerable amount of force is required to manually push down the piston against that strength. Work is difficult.

By the way, when considering the manual chuck removal work, a large force is required to move the piston downward, but considering relatively, instead of moving the pin groove downward, the large diameter part of the cylinder part is raised. It can be seen that the chuck can be removed by moving the ball to the large-diameter head, and in this way, the upward movement of the cylinder part should only resist the contact friction with the ball. The movement should be carried out with great force.

However, in the above-mentioned one, it is a considerable design to make a part of the cylinder and the large diameter part into a sleeve shape and to make them slidable inside the cylinder and to manually move the sleeve from the outside of the cylinder. It will need to be changed, and we cannot expect a simple implementation.

Therefore, in order to manually remove the chuck, when the engagement between the ball and the upper end of the chuck is released, it is stopped to directly move the portion supporting the weight of the chuck, and as described above, In order to move the portion that contacts the other side of the engaging portion of the ball for maintaining the engagement state with the upper end of the chuck, the portion for performing the movement is provided inside the cylinder of the main body,
By doing so, we considered to realize a device that can remove the chuck with a small manual force. As a result, in the fall prevention state, the weight of the chuck is supported on the main body side via balls,
In order to maintain that state, a push rod that contacts the inside of the ball is provided to keep the ball protruding outward, and a weak spring that pushes out the push rod to bring the push rod and ball into contact is provided. It is used so that the fall-off preventing state is continued, and the chuck can be easily removed manually by removing the push rod from the contact with the ball against the weak spring.

(Means for Solving Problems) In order to achieve the above-mentioned object, the present invention includes a main body 1 attached to an arm of a work robot or the like, and a spring housed in a first cylinder 3 at the base of the main body 1. The first piston 6 pushed forward by 7 and pulled back against the spring 7 by the air pressure or the operation of the lever 8 and the second piston 4 before the first cylinder 3 are housed in the second cylinder 4 and are moved forward and backward by air pressure. The moving second piston 9 and the ball holder 16 projecting from the work chuck 18 toward the main body 1 side are provided, and a chamber 10 into which the ball holder 16 is pushed from the front is provided at the center of the second piston 9. In the center of the holder 16, the first
A central chamber 16a into which the push-out rod 5 at the tip of the piston 6 is pushed later is provided, and a part of the ball 17 of the ball holder 16 is pushed out of the outer periphery thereof by the push-in of the push-out rod 5 described above. The chamber 10 of the second piston 9 is composed of a small-diameter chamber 10a at the inlet and a large-diameter chamber 10b at the back, and the slope 1 with which a part of the extruded ball 17 comes into contact with the boundary.
0c is provided so that when the ball holder 16 is pushed into the chamber 10 of the second piston 9, the ball 17 pushes the push rod 5 against the spring 7 to move it from the small diameter chamber 10a. The work chuck attachment / detachment device is characterized in that it is provided so as to be moved to the large diameter chamber 10b.

(Operation) Main body 1 in which the first piston 6 and the second piston 9 are housed
Is attached to the arm of an industrial robot or the like.
Further, the ball holder 1 projects from the work chuck 18 and is placed upward.

When the work chuck 18 is attached to the main body 1, the main body 1 is held with the second piston 9 facing downward.
Move it right above and lower it.

Then, the ball holder 16 is pushed into the chamber 10 of the second piston 9. At this time, since the ball 17 is located near the center of the ball holder 16 and does not go outside the outer peripheral surface thereof, the ball 17 smoothly passes through the small diameter chamber 10a. Then, before the balls 17 reach the large diameter chamber 10b, the inside of the balls 17 pushes the push rod 5
The push rod 5 is pushed against the spring 7 by hitting the tip of the push rod. Then, when the ball 17 reaches the large diameter chamber 10b,
The ball 17 becomes movable to the outside, and the ball 17
The lower end surface of the extruding rod 5 which is in contact with the peripheral surface of the push rod 5 pushes the ball 17 by the elastic force of the spring 7 to move the ball 17 outward, and as a result, the extruding rod 5 further advances to the peripheral surface of the ball 17 and the extruding rod 5. The outer peripheral surfaces of the are in contact with each other.

Here, the second piston 9 is moved upward (to the right in the figure) by air pressure. Then, the projecting surface of the ball 17 has a large diameter chamber 1
0b and the small diameter chamber 10a, the ball 7 hits the slope 10c at the boundary and pulls the ball 7 upward (right), so that the ball holder 16 or the work chuck 18 moves upward (right) and the main body 1
Bind to.

Next, when the work chuck 18 is detached from the main body 1, the first piston 6 is pneumatically pressed against the spring 7 so as to move upward (right).
Move to. Then, the push rod 5 moves upward (right) in the central chamber 16a and separates from the ball 17, and the ball 17 moves to the center and does not project outward from the outer periphery of the ball holder 16. The ball holder 16 is pulled out from the small diameter chamber 10a by smoothly passing through the 10a.

In the above, when the compressed air source fails during the work with the work chuck 18 mounted, the second piston moves down, but the second piston 9 is maintained while the contact between the pushing rod 5 and the ball 17 is maintained. Therefore, the ball 17 is positioned in the large diameter chamber 10b, the weight of the work chuck 18 is supported by the main body through the contact between the ball 17 and the slope 10c, and the work chuck 18 is prevented from falling off.

To manually remove the work chuck 18, the lever 8 is manually moved against the spring 7, and the push rod 5 comes out of contact with the ball 17.
8 is detached from the main body.

(Example) Next, the Example of this invention shown in drawing is described. Although the drawings are shown in a horizontal orientation, they are actually used in a vertical orientation. In the following description, left means lower and right means upper.

A body 1 having a cylinder inside is attached to a robot arm (not shown) through a hole 2 thereof. The main body 1 is provided with a first cylinder 3 and a second cylinder 4 having a slightly larger diameter continuously from the base to the front. A first piston 6 having an extruding rod 5 at the left end is provided on the first cylinder 3 so as to be pushed to the left by a spring 7. A pair of levers 8 is fixed to the right end of the first piston 6, and the tip of the lever 8 extends through the hole a of the main body 1.

The second piston 9 is provided in the second cylinder 4.
As shown in FIG. 3, the second piston 9 is formed by integrating a circular bottom plate and a cylindrical body having a diameter smaller than that of the circular bottom plate, and an opening having the same diameter as the push rod 5 is provided at the center of the bottom plate. A small-diameter portion 10a on the open side and a large-diameter portion 10b following it are formed in the inside 10 of the cylindrical body, and the boundary is a slope 10c. The outer diameter of the circular bottom plate is the same as the inner diameter of the second cylinder 4.

When the second piston 9 is inserted into the second cylinder 4,
As is apparent from FIG. 1, the outer circumference of the cylinder and the second cylinder 4
An annular space is formed between the inner circumference and the inner circumference. Further, the push-out rod 5 airtightly penetrates the central opening of the circular bottom plate of the second piston 9, and its tip projects into the inside 10 of the cylindrical body.

The tubular portion of the flange 12 is fixed to the left end of the main body 1 with a screw 11 in a state of being pushed into the annular space.
A space 13 having a slight width is formed between the open end of the second cylindrical portion and the circular bottom plate of the second piston 9 in a closed chamber state. This space 13 has a stroke in which the second piston 9 moves left and right. The main body 1 is provided with passages 1b and 1c so that compressed air is sent into the joint between the first piston 6 and the second piston 9 and the closed chamber 13.

A ball holder 16 is fixed to the right of the chuck holder 14 with a bolt 15 (FIG. 2). This ball holder 16
Has a cup-shaped tubular body, the outer diameter of the tubular body is the same as the small diameter portion 10a of the second piston 9, and the inner diameter of the tubular body central chamber 16a is the outer diameter of the pushing rod 5. A plurality of balls 17 having the same diameter are mounted near the open end of this cylindrical body. The diameter of the ball 17 is larger than the wall thickness of the cylindrical portion of the ball holder 16 so that the ball 17 can move inward and outward, and a part of the ball 17 can protrude outside and inside of the outer and inner circumferences. ing. The inner and outer ends of the hole through which the ball 17 moves are squeezed so that the ball 17 does not fall out of the ball holder 16. Further, the length of the push rod 5 is such that when the ball holder 16 is pushed into the chamber 10 from left to right, the balls 17 are
When it hits the tip of the push rod 5 before reaching b and moves further from this position, the ball 17 pushes the push rod 5 and the first piston 6 moves to the right against the spring 7, and the ball 17 moves to the large diameter chamber. 10b, and then the push rod 5 is pushed back by the spring 7 to return to its original state, and part of the ball 17 is projected into the large diameter chamber 10b, and the tip of the push rod 5 projects from the ball. The length is larger than the width of the closed chamber 13.

The work chuck 18 is fixed to the left of the chuck holder 14 with bolts 19. As shown in FIG. 2, a cylinder 21 of the work chuck 18 is provided with a piston 21, and the left end claw 22 is activated by the movement thereof.

A sleeve 23 having a passage 23a is embedded in the main body 1 in the axial direction, and a nipple 24 protruding rightward from the chuck holder 14 through the flange 12 is joined. A joint 25 having a T-shaped passage 25a is radially screwed into the work chuck 18 through the chuck holder 14, and the passage 14a communicating with the nipple 24 is passed through the cylinder 20.
Is in communication with.

The mounting of the work chuck thus configured will be described.
That is, the main body 1 is attached to the arm of the robot, and the work chuck 18 is separated from the main body 1. The robot arm is operated to direct the chamber 10 of the second piston 9 toward the ball holder 16 protruding from the work chuck 18, and then the main body 1 is moved to the left. Then ball 17
Does not project to the outside of the ball holder 16, so that the inside of the ball 17 passes through the small-diameter chamber 10a to the right and immediately before reaching the large-diameter chamber 10b from the small-diameter chamber 10a.
It hits the tip of the extrusion rod 5 in a. When the main body 1 is further pushed to the left, the ball 17 pushes the push rod 5 to the right, so that the first piston 6 compresses the spring 7 and moves to the right, and the ball 17 reaches the large diameter chamber 10b. Then, since the ball 17 has no outside resistance, the ball 17 is pushed out in the radial direction by the pushing rod 5 pushed by the spring 7, and a part of the ball 17 is pushed out.
Projecting outward from the outer circumference and entering the large diameter chamber 10b.

Next, when compressed air is passed through the passage 1c, the pressure in the closed chamber 13 pushes the second piston 9 to the right, the slope 10c pushes the left side of the ball 17 to the right, and the ball holder 16 moves to the right. The chuck holder 14 is attracted to the left surface of the flange 12 and the work chuck 18 is integrated with the main body 1.

When releasing the work chuck 18 mounted on the main body 1,
Do the following: That is, the compressed air is passed through the passage 1b. Then, the first piston 6 compresses the spring 7 and moves to the right, and the left end of the pushing rod 5 separates from the ball 17. Then, since the ball 17 has no inner support,
The ball 17 freely moves toward the center to move to the small diameter chamber 10a.
Then, the ball holder 16 comes out of the second piston 9, and the work chuck 18 separates from the main body 1.

The above is the attachment and detachment of the work chuck for normal replacement.

Next, regarding abnormal times, when the supply of compressed air is stopped during operation, the pressure in the closed chamber 13 decreases and the chuck 1
The chuck and the second piston 9 are both moved leftward (downward) by the own weight of 8. When moved slightly, the lower surface of the bottom plate of the second piston 9 reaches the upper surface of the cylindrical portion of the flange 12 and the descent stops. In this state, the outer peripheral surface of the pushing rod 5 is the ball 1
7 and the ball 17 and the slope 1 of the second piston 9
The engagement with 0c is maintained as it is, and the chuck 18 does not fall off.

Next, in order to manually remove the chuck in the above-mentioned state, the lever 8 is moved to the right (upward), whereby the pushing rod 5 is moved away from the contact with the ball 17, and the chuck 18 is moved. Ball 17 is second due to its own weight
It is pushed by the slope 10 of the piston and moves inward. As a result, the chuck 18 is separated from the second piston 9 and removed, as in the case of its own weight.

(Effect) As described above, in the automatic mounting of the work chuck, the push rod is pushed forward against the frictional resistance due to the contact between the outer circumference of the work chuck and the ball, and a spring for that is required. Since the resistance force is small, a spring with a weak force is sufficient. Therefore, it is sufficient that the pressure of the compressed air applied to move the first piston upward during the automatic removal is small.

Then, if necessary, the chuck will be manually removed, but in that case as well, the input applied to the handle to move the extrusion rod will be small, and the removal work will be completed. It will be easy.

[Brief description of drawings]

1 is a cut side view of a work chuck according to the present invention, FIG. 2 is a cut plan view thereof, and FIG. 3 is a side view in which a part of a second piston is cut out. The symbols in the figure are as follows. 1 ... Main body, 3 ... 1st cylinder 4 ... 2nd cylinder, 5 ... Extrusion rod 6 ... 1st piston, 7 ... Spring 8 ... Lever, 9 ... 2nd piston 10 ... Chamber, 10a ... Small diameter chamber 10b ... Large diameter chamber, 10c ... Slope 16 ... Ball holder, 16a ... Center chamber 17 ... Ball, 18 ... Work chuck

Claims (1)

[Claims] 1. A main body 1 attached to an arm of a work robot, and a first cylinder 3 at the base of the main body 1 which is housed in a first cylinder 3 and is pushed forward by a spring 7 so that the spring 7 can be operated by air pressure or by operating a lever 8. First piston 6 pulled back against
A second piston 9 housed in the second cylinder 4 in front of the first cylinder 3 and moving forward and backward by air pressure; and a ball holder 16 protruding from the work chuck 18 toward the main body 1 side. A chamber 10 into which the ball holder 16 is pushed from the front is provided in the center of the second piston 9, and a central chamber 16a into which the pushing rod 5 at the tip of the first piston 6 is pushed from the rear is provided in the center of the ball holder 16. , The ball 17 of the ball holder 16 is pushed by pushing the extruding rod 5 as described above.
Is provided so that a part of the
The chamber 10 of the piston 9 is composed of a small diameter chamber 10a at the inlet and a large diameter chamber 10b at the back, and a slope 10c with which a part of the extruded ball 17 comes into contact is provided at the boundary between the chamber 10 and the extruding rod 5
When the ball holder 16 is pushed into the chamber 10 of the second piston 9, the ball 17 pushes the pushing rod 5 against the spring 7 and moves from the small diameter chamber 10a to the large diameter chamber 10b. A work chuck attachment / detachment device that is provided.