JPH0624883U - Gripper device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a gripper device that can be easily attached to an existing arm and that can appropriately grip a work even when the work diameter changes and the grip center deviates. To do. A pair of holders 2 each having a proximal end rotatably attached to an arm 1 and a front end capable of being opened and closed, and a pair of opposing pairs having a central portion swingably pivoted in an opening / closing surface of each holder 2. Grippers 4 and a V-shaped gripping portion 7 formed of a pair of gripping surfaces 7a formed at the facing portions of the grippers 4 and intersecting at the central portion of the grippers 4, and the grippers 4 described above.
The gripper 4 is contracted between the end of the holder and the holder 2.
And a spring 8 for elastically urging the end portion of the spring toward the gripping surface 4a.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gripper device for gripping a cylindrical or cylindrical work such as a shock absorber which is an automobile part, for transporting, processing, etc.

[0002]

[Prior art]

Conventionally, this type of gripper device is disclosed in, for example, Japanese Utility Model Laid-Open No. 61-120493. As shown in FIG. 7, this gripper device is composed of a pair of fingers 14 and 15 pivotably attached to an arm 11 by hinge pins 12 and 13, and the tips of the fingers 14 and 15 are V-shaped. The gripping surfaces 14a and 15a are formed, and a spring 16 for urging the gripping surfaces 14a and 15a in a direction of approaching the gripping surfaces 14a and 15a is stretched between the proximal ends of the fingers 14 and 15. Then, the work center when gripping the small-diameter first work W ₁ coincides with the work center when gripping the large-diameter second work W ₂ , and the first work W ₁ The center of rotation of the fingers 14 and 15 at the time of gripping and at the time of gripping the second work W ₂ are configured to match, and even if the diameter of the work changes, the work is at the same position and in the same posture. Can be grasped.

[0003]

[Problems to be solved by the device]

 However, since the conventional gripper device has a structure in which the work is gripped while the fingers 14 and 15 are entirely equalized, the gripping center of the arm 11 that has been fixed at one end and is transferred from the center of the work to be gripped. If it shifts, it cannot be gripped. Further, since the fingers 14 and 15 are crossed for gripping the work, one of the fingers must have a bifurcated shape, resulting in a complicated structure. Furthermore, it is not easy to modify an existing (commercial) arm to use a special finger.

The present invention has been made to solve the above-mentioned problems, and can be easily attached to an existing arm, and the work can be accurately attached even when the work diameter changes or the gripping center deviates. It is an object of the present invention to provide a gripper device that can be gripped on the ground.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the gripper device of the present invention comprises a pair of holders whose base end is rotatably attached to an arm and whose front end can be opened and closed, and a central part at the front end in the opening and closing surface of each holder. A pair of opposing grippers whose parts are swingably pivoted, and a pair of gripping faces formed at the opposing parts of each gripper and intersecting at the center of the grippers, and V-shaped gripping parts, A spring is provided between the end of the gripper and the holder and elastically biases the end of the gripper toward the grip surface.

[0006]

[Action]

 With the above configuration, when the workpiece hits the gripping surface on one end side of the gripper and does not hit the gripping surface on the other end side in the process of closing the holder, the gripper tilts while compressing the spring on the side where the work hits. Both sides of the gripping surface, which are in the shape of a letter, hit the work together. Therefore, even if the diameter of the workpiece changes or the center of the workpiece and the center of gripping the holder deviate, the workpiece is gripped.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a front view showing the gripper device, FIG. 2 is a side view of the same, FIG. 3 is an enlarged front view (only one side is shown) showing a main part with partial breakage, and FIG. 4 is a left side view of the same.

In these drawings, reference numeral 1 denotes an arm (a wide-angle hand, which is a commercially available product in the embodiment), and the base ends 2a of a pair of holders 2 are provided in the arm 1 in reciprocal directions about fulcrums P, P. It is rotatably attached and the tip 2b can be opened and closed.

Inside the opening and closing surface of each holder 2, a central portion of a V-shaped gripper 4 is pivotally mounted by a hinge pin 5 so that the gripper 4 is arranged so as to face each other. There is. Incidentally, 6 is a retaining ring for preventing the hinge pin 5 from coming off.

A V-shaped gripping portion 7 including a pair of gripping surfaces 7 a that intersects each other at an obtuse angle in the central portion is formed at the facing portion of each gripper 4. Further, recesses 4a are formed on both ends of the gripper 4 and on the opposite side of the gripping surface 7a.

Reference numeral 8 denotes a spring, which is inserted into a concave portion 4 a provided at both ends of the gripper 4 and a concave portion 2 c formed in the holder 2 so as to face the concave portion 4 a, and is provided between the end portion of the gripper 4 and the holder 2. It is contracted, and urges the end of the gripper 4 toward the grip surface 7a. In this embodiment, two springs 8 are provided at each end of the gripper 4.

Next, the operation of the gripper device will be described with reference to FIGS. 5 and 6.

In the process of closing the holder 2, when the work W hits the gripping surface 7a on one end side of the gripper 4 and does not hit the gripping surface 7a on the other end side, the gripper 4 sets the spring on the side where the work W hits. While compressing 8, while tilting along the work W within the range of the maximum bending amount of the spring 8 or the distance between the holder 2 and the end of the gripper 4 about the hinge pin 5, the V-shaped ends are formed. Both of the gripping surfaces 7a and 7a of the above contact the work W. That is, the gripping portion 7 tilts and grips the work W so as to eliminate the uneven contact of the work W. For this reason, as will be described later, even if the diameter of the work changes or the center of the work W deviates from the center of gripping the holder 2, the work is reliably gripped.

The gripping function will be described in more detail. In FIG. 5, the positions of the holder 2, the gripper 4, the pin hinge 5 and the spring 8 when the workpiece W ₁ having the outer diameter D ₁ is gripped are shown by solid lines, and the outer diameter D larger than the outer diameter D ₁ is shown. ₂ of the workpiece W ₂ position of the respective components when grasped by the same core is indicated by a chain line. The difference between the outer diameters D ₁ and D ₂ of the work that can be seen from FIG. 5 is absorbed by the swing angle β of the gripper 4, the rotation angle α of the holder 2 and the strain angle γ of the spring 8, and the work outer diameter The grippers 4 and 4 grip the work regardless of size.

Further, as shown in FIG. 6, when the center of the work W having the same outer diameter is shifted from O to O ′ by a distance e, each component is moved from the position shown by the solid line to the position shown by the chain line. The shift amount e is absorbed by the swing angle β of the gripper 4, the rotation angle α of the holder 2 and the strain angle γ of the spring 8, and the gripper 4 shifts the work W at the position of the work center O ′ that is displaced by the distance e. Hold it.

The same applies when the outer diameter of the work is different and the core is displaced. In any case, the holding force for the work is determined by the strength of the spring 8 and the closing force of the holder 2.

[0018]

[Effect of device]

 As described above, the present invention has a pair of holders whose base ends are rotatably attached to the arms and whose front ends can be opened and closed, and a pair of holders which face each other and whose central portions are swingably pivoted in the opening and closing surfaces of the holders. Between a pair of grippers, a V-shaped gripping portion formed at a facing portion of each gripper and having a pair of gripping surfaces intersecting at the center of the gripper, and between the end of each gripper and the holder. It is provided with a spring that is compressed and elastically urges the gripper end in the direction of the gripping surface, and absorbs by gripper tilt, holder displacement and spring elasticity against changes in the work outer diameter and misalignment. Therefore, the work can be reliably held by the same gripper. In other words, it is possible to handle workpieces with different outer diameters without changing the setup of the gripper, and it is possible to flexibly absorb the misalignment of the arm with respect to the workpiece and grip the workpiece. The work can be inserted smoothly even if the work is set on a pallet without precise positioning.

[Brief description of drawings]

FIG. 1 is a front view showing a gripper device according to an embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is an enlarged front view showing the main part of FIG. 1 in a partially cutaway manner.

FIG. 4 is a left side view of FIG.

FIG. 5 is a diagram for explaining the operation of the gripper device of FIG. 1 when the work diameters are different.

6A and 6B are views for explaining the operation of the gripper device in FIG. 1 in the case where the center of the work and the center of the holder are misaligned.

FIG. 7 is a front view showing a gripper device of a conventional example.

[Explanation of symbols]

 1 Arm 2 Holder 4 Gripper 5 Hinge Pin (Pivoting Part) 7a Grip Surface 8 Spring

Claims (1)

[Scope of utility model registration request] 1. A pair of holders whose base end is rotatably attached to an arm and whose front end can be opened and closed, and a pair of opposed pair of holders whose center is swingably pivoted in the opening and closing surface of each holder. A gripper, a V-shaped gripping portion formed at a facing portion of each gripper and having a pair of gripping surfaces intersecting at a central portion of the gripper, and contracted between an end portion of each gripper and a holder. A gripper device comprising: a spring for elastically urging the gripper end in the direction of the grip surface.