JPS6229192B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a robot hand that can be detachably equipped with a chuck that can grip rod-shaped parts such as nuts and bolts, and can also directly grip parts that have plate-shaped parts. . Typically, a robot hand is equipped with an actuator that uses electrical signals or air, and a detector such as an encoder, potentiometer, or reed switch. That is, lead wires and electrical contacts are essential in order to drive a motor or operate a detector using electrical signals. Furthermore, when a robot hand handles many types of parts and their sizes vary from large to small, it is inappropriate for one hand to handle all the parts. This is because when attempting to grasp parts with a large difference in size, the opening and closing distance of the hand, that is, the stroke, must be increased, which increases the size and weight of the hand itself. Furthermore, if an attempt is made to grasp parts that differ greatly in shape, material, quality, etc., the hand will have a complicated shape and have multiple functions, which will be disadvantageous in terms of economy, reliability, and commercial value.

For this purpose, several hands are prepared and each hand is assigned a function, thereby reducing size and weight, lowering costs, and improving reliability. In recent years, it has become a common technology to use a robot to automatically replace hands by selectively selecting hands with functions appropriate to the parts.

Next, a conventional robot hand having a changing device will be explained with reference to FIGS. 1 and 2.

FIG. 1 is a partial sectional view of a conventional robot hand, and FIG. 2 is a partial sectional view showing an example in which 15a and 15b shown in FIG. 1 are made into a contact structure.

In FIGS. 1 and 2, a housing 2 is attached to a wrist 1 of a robot by bolts 3. As shown in FIGS. This housing 2 is provided with an air supply port 4, and a holding part 5 is fixed therein, in which a plurality of steel balls 6 are movably housed. Further, the housing 2 is provided with a groove 7 for determining the direction of the hand. This housing 2 and holding part 5
A cylinder 8 is inserted between them, and its piston portion is normally lifted by a spring 9. This piston section is moved by air pressure supplied from the air supply port 4, and a kettle section 10 at its tip presses the steel ball 6 to prevent the steel ball 6 from returning.

The hand portion 11 has a shape that can be engaged with the holding portion 5, and is held by the steel ball 6 pushed out by the gauntlet portion 10. Note that this hand portion 11 has a pin 12 that enters the groove 7 and determines the direction.
A DC motor 13 is provided, and the hand 14 can be opened and closed. Also, this hand part 1
The connector 15b provided in the housing 2
The connector 15b is connected to the DC motor 13 of the hand section 11 by engaging with the connector 15a provided on the outer periphery of the hand section 11.
is connected to.

FIG. 1 shows that the hand part 11 engages with the holding part 5,
It is held by a plurality of steel balls 5 and is simultaneously connected to a connector 15.
A and 15b are shown engaged and electrically connected. When replacing this hand portion 11 with another hand, the piston of the cylinder 8 is lifted by the spring force of the spring 9 by stopping the supply of air from the air supply port 4, and the pressing of the steel ball 6 is released. It becomes possible to move freely within the constraints of the steel ball 6. Then, the hand section 11 can be detached from the holding section 5 by its own weight. In addition, air is supplied from the air supply port 16 to ensure reliable separation. The connectors 15a and 15b are grooved so that they can be easily engaged with each other when the hand portion 11 is detached and attached. Therefore, by engaging the hand portion of another hand with the holding portion 5 and supplying air from the air supply port 4, the piston of the cylinder 8 descends against the spring force of the spring 9, as described above. The tapered part 10 at the tip presses the steel ball 6 against the holding part 5 to fix the hand part, and at the same time, the connectors 15a and 15b are also electrically connected to form a hand function. Note that Figure 2 is the same as Figure 1.
This is an example in which electrical connection is made using contacts 15c and 15d instead of the connectors 15a and 15b shown in the figure.

In this way, the conventional robot hand has a complex structure on the wrist of the robot, and has a function for attaching and detaching the hand, and by engaging the hand part with this,
I am trying to fix the hand and make electrical connections. Therefore, electrical contacts were required, which caused reliability problems.

The present invention improves the above-mentioned robot hand, eliminates the need for electrical connection when replacing the hand, allows for a removable attachment of a chuck capable of gripping bar-shaped parts such as nuts and bolts, and moreover allows the robot hand to be attached directly to a plate-shaped part. It is an object of the present invention to provide a robot hand capable of grasping parts having the following characteristics.

In order to achieve the above object, the present invention provides a gripper attached to the wrist of a robot.
A fitting part having a hole in the center having an air supply port connected to an air supply source is provided at the center, and a plurality of claws pointing toward the center are provided at the lower end by guiding means around the fitting part. A feed screw that is attached to a plurality of members that are slidably supported in a horizontal direction and that fits into each of the members and a motor that is connected to the feed screw is attached to a plurality of members that are slidably supported in a horizontal direction, and that opens and closes the pawl centering on the fitting portion. a shaft section that is normally pushed up by a spring and pushed down by the pressure of the air, and equipped with a piston at the top that has a cam at the bottom end;
a pair of chuck members rotatably supported at the lower part of the shaft portion and configured to close when the cam descends and open when the cam rises and the tension of the tension spring; and the plurality of claws. A chuck having a collar formed at the lower part of the shaft portion so as to be held by closing the chuck is removably configured in the center, and detecting that the chuck is attached to the fitting portion. The chuck is capable of gripping a component having a plate-shaped portion with the claws when the chuck is removed, and the chuck member of the chuck can grip another type of component when the chuck is attached. This is a robot hand characterized by being configured as follows.

Next, one embodiment of the present invention will be explained with reference to FIGS. 3 to 10.

This embodiment relates to a robot hand for handling parts to be assembled as shown in FIG. That is, as shown in FIG.
0 and tighten with a nut 21. The main body 23 is a large component, and these components have different sizes, so the flanges 22a, 2
A shared hand A that handles the main body 23 and the port 2b and a shared hand B that handles the port 20 and the nut 21 can be used by appropriately replacing them. The assembly system, as shown in FIG.
A gripper 31 is attached to which the shared hand A is attached. A BN chuck 32 having the shared hand B at a position within the working range of the gripper 31
are arranged and configured to be attached to the gripper 31 as necessary. Further, an assembly worker 33 is arranged below the gripper 31, and each part supplied by each component supply device is positioned on the assembly worker 33, and then assembled by a robot and finally delivered. In the process, the bolt 20 is passed through the hole in the flange, and the screw tightener 34 tightens the bolt 20 with a predetermined torque.

FIG. 5 shows the appearance of the BN chuck 32 and the active tool 35 in the standby position. This BN chuck 32
The chucks 37a and 37b can be opened and closed by supplying air from the air supply port 36. The tool 35 is provided with a hole 39 into which the BN chuck 32 is inserted, and a protrusion 40 for orienting the BN chuck 32.
The dimensions are such that it can be engaged with the groove portion 41 of.

Figure 6 shows the gripper 31 and its installation.
The appearance of the BN chuck 32 is shown.

The gripper 31 is attached to the robot wrist 30. A DC motor 42 is mounted on the gripper 31, and feed screws 43a, 43b
By rotating the guide shafts 44a, 44
Claws 45a, 45b are provided to be guided by b, and protrusions 46 are provided on the tabs 45a, 45b, so as to serve to prevent the flanges 22a, 22b and main body 23 from falling when gripped. Therefore, the weight of the component is supported by the projection 46, and the component is held between the four claws 45a and 45b, so that the gripping force can be reduced. That is, the capacity of the DC motor 42 can be selected to be small. Further, the strokes that the claws 45a, 45b can move are set to be only the amount necessary to grip the flanges 22a, 22b and the main body 23. To apply to five different sized flange and main body models, all you need to do is replace the tabs with different shapes. Further, a fitting part 48 that can be engaged with a fitting part 47 of the BN chuck 32 is provided at the lower part of the gripper 31, and the chucks 37a and 37b of the BN chuck 32 are operated by supplying air from an air supply port 49.

FIG. 7 shows a state in which the BN chuck 32 is attached to the gripper 31.

That is, the robot wrist 30 descends relative to the BN chuck 32 in the standby position, and at the same time the claw 45
The gripper 31 descends with a and 45b open. Then, the fitting part 48 of the gripper 31
and the fitting portion 47 of the BN chuck 32 engage with each other.
After that, the DC motor 42 rotates, and the claw 45
a, 45b in the closing direction. At this time
Since the outer diameter of the collar 38 of the BN chuck 32 is the same as the outer diameter of the main body, the claws 45a, 45b
gripped by. Further, the protrusion 46
8 and supports the BN chuck 32. When detaching this BN chuck 32 from the gripper 31, turn the DC motor 42 onto the claw 45.
This is possible by rotating a and 45b in the opening direction.

FIG. 8, FIG. 9, and FIG. 10 are diagrams to supplement the above explanation, and show the fitted state of the gripper 31 and the BN chuck 32, and the four claws 45a, 45.
b shows a state in which the collar 38 is gripped and supported.

In FIG. 8, the fitting portion 4 of the gripper 31
8 has a simple structure, with only one O-ring 50 for preventing leakage of air supplied from the air supply port 49. Inside the BN chuck 32, a cylinder section 51 operated by air pressure supplied from an air supply port 49 is composed of a piston 52 and a spring 53, with a cam 54 at the bottom and a cap 55 at the top, sandwiching the piston 52. is attached and engaged with the piston 52. When air is supplied from the air supply port 49, the piston 52 moves downward against the force of the spring 53. That is, by lowering the cam 54, the chuck member 37
The rollers 56 provided at the upper ends of a and 37b are pushed apart, and the chuck member 37 is moved around the fulcrum 57.
Close a and 37b. The chuck member 37a,
When opening 37b, the piston is pushed up by the spring 53 by stopping the supply of air from the air supply port 49, and at the same time the cam 54 also moves upward. Then, the chuck members 37a and 37b open around the fulcrum 57 due to the restoring force of the tension spring 58.

Next, in FIG. 9, the potentiometer 60
is attached to the bracket 61 of the gripper 31. This potentiometer 60 is BN
This is to detect whether the chuck 32 is completely fitted into the gripper 31 side, and the rod 6 having a roller 63 with a spring 62 in between is used.
4 is provided. That is, since the cap 55 is sloped, the BN
Incomplete engagement of the chuck 32 will result in a difference in the amount of axial movement of the potentiometer 60. Since the difference in the amount of movement becomes an electric signal, it is possible to detect whether the BN chuck is completely or incompletely fitted into the gripper 31.

FIG. 10 shows a cross section taken along line ABCD in FIG. 8. In FIG. 10, cam 54 is in contact with the surface of liner 70 to prevent its rotation. Further, the claws 45a and 45b that sandwich the collar 38 of the BN chuck 32 form a surface 71 to make it easier to pinch the main body 23 and the claw 45.

As explained above, according to the present invention, there is a function of gripping a part having a plate-like part, and a function of being able to be detachably attached to a chuck that grips another rod-like part, and these can be arbitrarily selected. With this structure, when assembling parts of different sizes, there is no need to replace the chuck each time, and the parts can be assembled very efficiently.Furthermore, there is no need to make electrical connections when installing the chucks. Therefore, it is possible to obtain a robot hand with high reliability.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of a conventional robot hand, and FIG. 2 is a partial sectional view showing an example in which 15a and 15b shown in FIG. 1 are made into a contact structure. Figure 3 is a perspective view of the parts to be assembled in the embodiment of the present invention, Figure 4 is a side view of the assembly system of this embodiment, Figure 5 is a perspective view of the BN chuck, Figures 6 and 7 are A perspective view of the gripper and BN chuck, Fig. 8 is a partially cutaway front view of Fig. 7, Fig. 9 is a partially cutaway side view of Fig. 8, and Fig. 10 is a cross section taken along line ABCD of Fig. 8. It is a diagram. 30...Robot Wrist, 31...Gritzper,
32...BN chuck, 37a, 37b...chuck member, 42...DC motor, 43a, 43
b...Feed screw, 44a, 44b...Guide shaft,
45a, 45b...claw, 46...protrusion, 47
...BN chuck fitting part, 48...Gripper fitting part, 49...Air supply port, 50...0 ring, 51...Cylinder, 52...Piston, 5
3...Spring, 54...Cam, 55...Cap,
56...roller, 57...fulcrum, 58...tension spring, 60...fitting detector, 61...bracket, 62...spring, 63...spring, 64...rod.

Claims (1)

[Claims] 1 In a gripper attached to the robot's wrist, a fitting part is provided at the center with a hole having an air supply port connected to an air supply source at the center, and a plurality of claws pointed toward the center are provided at the lower end. of,
A feed screw is attached to a plurality of members that are horizontally slidably supported around the fitting portion by guide means, and is fitted into each of the members to open and close the pawl centering on the fitting portion. and a motor connected to this feed screw, which is normally pushed up by a spring and pushed down by the pressure of the air, and has a shaft with a piston at the top that has a cam at the bottom end, and a rotating shaft at the bottom of the shaft. A pair of chuck members that are freely supported, are configured to close when the cam descends, and open when the cam rises and the tension of a tension spring, and are held by closing the plurality of claws. a chuck having a collar formed at the lower part of the shaft portion so as to be detachable from the center thereof, and a detecting means for detecting that the chuck is attached to the fitting portion; It is characterized by being configured such that when the chuck is removed, the claws can grip a component having a plate-like portion, and when the chuck is attached, the chuck member of the chuck can grip another type of component. A hand for robots.