JPS6125992Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a hand device for an industrial robot for loading workpieces into machine tools.The purpose of this invention is to change the hand device when the external force is below a certain value. When the external force exceeds a certain value, it works by maintaining a rigid body, and when the external force exceeds a certain value, it can be displaced in response to this external force, absorbing the relative error with the workpiece, etc., and thereby preventing scratches on the workpiece and the robot. In addition, the clamp device part of the hand device can rotate around the workpiece while maintaining its axis, and it is also possible to clamp circular workpieces with different diameters at the same center at all times. The purpose of the present invention is to provide a robot hand device.

The configuration will be explained below based on the embodiment shown in the drawings.

In the figure, reference numeral 1 denotes a clamp body provided at the tip of an arm 2 of an industrial manipulator.The end of the clamp body 1 is concave in an arc shape, and a guide part 3 having a dovetail groove 3a along the arc is provided in this part. It is provided. A back portion of a clamp support body 4 formed in a semicircular arc shape is engaged with this guide portion 3 so as to be slidable in an arc direction centered on the clamp center O. The clamp body 1 is provided with a cylinder device 5 and pulleys 6a and 6b on both sides of the cylinder device 5, and one ends of strings 7a and 7b are connected to both sides of the piston 5a of the cylinder device 5, After exiting the cylinder of the cylinder device 5, the strings 7a and 7b are wound around pulleys 6a and 6b, and then intersected with each other and connected to the clamp support 4.

8a, 8b, and 8c are fingers having the same length and each having a cylindrical tip 9 at the tip, and the base of each finger is located at a rotation center Oa, Ob, which is arranged concentrically with respect to the clamp center O. , Oc are rotatably supported on the clamp support 4. And each finger 8a, 8
b, 8c are interlocked and connected to a clamp cylinder device 10 attached to the clamp support 4 via links 11, 12 and gears 13, 14, and the fingers 8a, 8b, 8c are always rotated by the same rotation angle from the periphery toward the clamp center O at a constant angular velocity.

On the other hand, 15 is a buffer joint interposed between the arm 2 and the clamp body 1, and this buffer joint 15
The cylinder 16 fixed to the arm 2 and the cylinder 1
Spherical bush 1 slidably provided in the axial direction within 6
7, a spherical body 18 supported thereon, and springs 17a, 1 that clamp this spherical body 18 from both sides in the axial direction.
The clamp main body 1, which is a driven member, is connected to the spherical body 18. 21 is the spring 19b
It is a cap that receives. Further, 22, 22 are flanges interposed between the end face of the spherical body 18 and the collars 20a, 20b. And these flanges 2
The interval between the springs 2 and 22 is the same as the width of the stepped portion of the cylinder 16, and the stepped portion provides a preload to the springs 19a and 19b.

Reference numeral 23 denotes a detent device for buffering the rotational direction, in which pins 24, 24 protruding from the cap 21 at positions offset from the axis and a bracket 25 protruding from the clamp body 1 are used to provide the buffer via a spring 26. The joints 15 are connected in a rotational direction about the axis of the joint 15.

In the above configuration, the clamp cylinder device 10
By extending and contracting the fingers 8a, 8b,
8c rotates at a constant angular velocity and an equal rotation angle with respect to the clamp center O, and the tip 9 at the tip performs clamping and unclamping operations.

On the other hand, by extending and contracting the cylinder device 5 of the clamp body 1, the clamp support body 4 slides around the clamp center O with respect to the clamp body 1, and its position is changed.

Further, when a pressing force of more than a predetermined value is applied to the clamping device in the axial direction, the spring 19a on the arm 2 side is bent and the spherical bushing 17 moves toward the arm 2 side. When the spring 19b on the clamp body 1 side bends and moves together with the spherical bushing 17 towards the clamp body 1 side, and when a force of more than a predetermined value is applied to the clamp body side in the lateral vibration direction, the spherical bushing 17 moves against both springs 19a,
They rotate against the biasing force of 19b, and are respectively buffered.

When attaching a workpiece clamped by the above-mentioned clamping device to the chuck of a lathe, etc., the workpiece is pressed against the chuck mounting surface by the movement of the robot body or the tailstock, but at this time, if the clamping force of the fingers is too strong, There is a risk of damage to the fingers.
On the other hand, if it is too weak, the workpiece may be dropped during transport. In order to deal with this, it is necessary to reduce the thrust of the clamp cylinder device 10 to bring it into a half-clamp state. An embodiment for this purpose is shown in FIG.

That is, the clamp cylinder device 10 is composed of a single-rod cylinder, with the bottom chamber 10a of the cylinder device 10 serving as the clamp side, and the rod chamber 10b serving as the clamp side.
is the unclamp side, and both chambers 10a and 10b
A switching valve 28 having forward and reverse positions A and B and a common position C that guides pressure to both chambers is interposed between the chamber and the hydraulic power source 27.

Therefore, when the cylinder inner diameter is D, the rod diameter is d, the pressure receiving area on the clamping side of the piston 29 is S ₁ , the pressure receiving area on the unclamping side of the piston 29 is S ₂ , and the cross-sectional area of the rod is S ₃ , the full clamping force F If the oil is P _p , _f is F = S ₁ × P _p , but if the switching valve 28 is switched to the common position C and hydraulic pressure is supplied to both chambers 10a and 10b, half clamping occurs, and the clamping force at this time is F _h becomes F _H = (S ₁ - S ₀ ) x P _p = S ₃ · P _p . Therefore, the ratio between the full clamping force F _f and the half clamping force F _h is F _h /F _f = S ₃ P _p /S ₁ P _p = (d/D) ² , and the switching valve 28 is set to the common position C. By doing so, it is possible to obtain a half clamp F _h with a smaller force than the full clamp force F _f .

The industrial robot hand device according to the present invention is
As mentioned above, the shock absorber joint 15 is elastically deformed when a predetermined force or more is applied to the tip of the arm 2 of the industrial robot in the axial direction and the lateral vibration direction.
A clamp body 1 formed in an arc shape with the clamp center O as the center is attached, and a guide part 3 formed along the longitudinal direction of the arc-shaped clamp body 1 is attached with a clamp body 1 having the same arc shape as the arc of the clamp body 1. slidingly engages the back of the clamp support 4 formed in the
The other ends of a pair of strings 7a and 7b each having one end connected to both ends of the clamp support 4,
The clamp center O of the clamp support 4 is connected to both ends of the piston 5a of the cylinder device 5 provided on the clamp body 1 after being aligned with the back surface of the clamp support 4. The bases of at least three fingers 8a, 8b, 8c of the same length are attached to the bases of at least three fingers 8a, 8b, 8c, which are swingable about at least three points Oa, Ob, Oc that are concentric with and spaced apart from each other, and have the same length. Each of the fingers 8a, 8b, 8c is interlocked and connected to the clamp cylinder device 10 via an interlocking mechanism so that the tip of each finger swings by an equal angle with respect to the clamp center O at a constant angular velocity. Between the bottom chamber 10a and the rod chamber 10b of the device 10 and the hydraulic source 27, the bottom chamber 10a is connected to the hydraulic source 27 and the rod chamber 1 is connected to the hydraulic source 27.
0b to the tank, the rod chamber 10b to the hydraulic power source 27, and the bottom chamber 1
0a to the tank, and a common position C to communicate both the bottom chamber 10a and the rod chamber 10b to the hydraulic power source 27, the arm 2 is moved to clamp the valve. Position the main body 1 near the workpiece to be gripped,
By moving the piston 5a of the cylinder device 5, the clamp support 4 is moved relative to the clamp body 1.
is brought into a position adapted to the workpiece, and then by actuating the clamp cylinder device 10, at least three
The workpiece is gripped by operating the fingers 8a, 8b, 8c, and even if the workpieces have different diameters, not only will no harm occur, but the fingers 8a, 8b , 8c can be clamped at the same center by swinging by an equal angle with respect to the clamp center O at a constant angular velocity, and each of the fingers 8a, 8b, 8c
The workpiece gripped by the workpiece can be rotated while maintaining its center by moving the piston 5a of the cylinder device 5, and
Versatility can be increased. Furthermore, since the back of the clamp support 4 is slidably engaged with the guide portion 3 of the clamp body 1 formed in the same arc shape, not only the operation is smooth, but also A pair of connected strings 7a, 7b
Since the other end is connected to both ends of the piston 5a of the cylinder device 5 and operated by the movement of the piston 5a, the operation is reliable and highly reliable. , 7b are aligned with the back surface of the clamp support 4, so they do not get in the way. Moreover, the bottom chamber 10a and the rod chamber 10b of the clamp cylinder device 10
Since the switching valve 28 having the normal and reverse positions A and B and the common position C as described above is interposed between the and the hydraulic power source 27, by switching the switching valve 28, each of the fingers 8a, 8b, 8c can be operated. Of course, it can be operated to move to the gripping position where the workpiece is clamped and the retreat position where the workpiece is unclamped.
It is possible to put the workpiece into a half-clamp state where the workpiece is lightly clamped, and is suitable when the workpiece is made of a material that is easily damaged. Furthermore, since a buffer joint 15 is interposed between the arm 2 and the clamp body 1, which is elastically deformed when a predetermined force or more is applied in the axial direction and the lateral vibration direction, the fingers 8a, 8b, 8c Even if an external force is applied to the clamp body 1 via the clamp body 1, if the external force is less than a certain value, the buffer joint 15 will not be displaced and will work to maintain a rigid body, resulting in reliable movement, and the external force will remain at a constant value. If this occurs, elastic deformation can occur to prevent damage to the workpiece or damage to the fingers 8a, 8b, 8c, etc.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a plan view with the lid of the clamping device removed and a partially cutaway view, Fig. 2 is a cross-sectional view taken along the - line of Fig. 3 is a sectional view taken along the - line in FIG. 1, and FIG. 4 is a circuit diagram showing the half clamp mechanism. 1 is a clamp body, 2 is an arm, 4 is a clamp support, 8a, 8b, 8c are fingers, and 15 is a buffer joint.

Claims (1)

[Scope of utility model registration request] A clamp body formed into an arc shape centered on the clamp center O is connected to the tip of the arm 2 of an industrial robot via a buffer joint 15 that elastically deforms when a force exceeding a predetermined value is applied in the axial direction and the lateral vibration direction. 1
is attached, and the back part of the clamp support 4, which is formed in the same arc shape as the arc of the clamp body 1, is slidably on the guide part 3 formed along the longitudinal direction of the arc-shaped clamp body 1. After the other ends of the pair of strings 7a and 7b, which are engaged and have one end connected to both ends of the clamp support 4, are placed along the back surface of the clamp support 4, the clamp body 1
The clamp support body 4 has at least three cylinders which are concentric with the clamp center O of the clamp support body 4 and are spaced apart from each other.
At least three fingers 8 that are swingable around points Oa, Ob, and Oc and have the same length.
The bases of the fingers 8a, 8b, and 8c are attached, and each of the fingers 8a, 8b, and 8c is attached to a clamp cylinder via an interlocking mechanism so that the tips of the fingers 8a, 8b, and 8c swing by an equal angle with respect to the clamp center O at a constant angular velocity. It is interlocked with the device 10 and has a bottom chamber 10a and a rod chamber 10b of the clamp cylinder device 10.
and the hydraulic source 27, a normal position A that communicates the bottom chamber 10a with the hydraulic source 27 and the rod chamber 10b with the tank; Reverse position B communicating with the tank and the bottom chamber 10
A hand device for an industrial robot, characterized in that a switching valve 28 having a common position C communicating both the rod chamber 10b and the hydraulic pressure source 27 is installed.