JP2021164977A - Clamping device and workpiece holding method - Google Patents

Abstract

To hold a workpiece at three points without changing a workpiece direction.SOLUTION: A clamping device comprises: a stage 20 for being loaded with a workpiece; a holding part 30 for holding the workpiece, which is loaded on the stage 20, between two first abutting parts 33 provided for a first holding claw 31 and a second abutting part 34 provided for a second holding claw 32, by moving at least one of the first and second holding claws 31 and 32 in a first direction D1; and a positioning part 40 for positioning the workpiece in a prescribed position in a second direction D2 perpendicular to the first direction D1. The holding part 30 holds the workpiece between the two first abutting parts 33 and the second abutting part 34, after positioning the workpiece in the prescribed position in the second direction D2 by the positioning part 40.SELECTED DRAWING: Figure 1

Description

The present invention relates to a clamping device and a method of holding a work.

As a clamping device that clamps (holds and fixes) the work when processing the work (object to be fixed), it is known that a pair of holding claws are moved close to the work to hold the work between the pair of holding claws. (For example, see Patent Document 1 below).

In such a clamping device, when a pair of holding claws holds a work on a curved surface portion, one of the pair of holding claws comes into contact with the work at two contact portions and the other is in contact with the work in order to hold the work stably. A pair of holding claws may be provided so as to come into contact with the work at one contact portion and hold the work at three points.

Japanese Unexamined Patent Publication No. 6-126553

However, when the clamp device holds the work, if the work is located at a position deviated from the fixed position of the work, the timing of pressing the work is deviated by the three contact portions provided on the pair of holding claws. As a result, the direction of the work may change due to the force received from the contact portion that first comes into contact with the work, which may interfere with the process after holding and fixing the work.

The present invention has been made in view of the above points, and an object of the present invention is to provide a clamp device capable of holding a work at three points without changing the orientation of the work and a method for holding the work.

In the clamp device according to the present invention, the stage on which the work is placed and at least one of the first holding claw and the second holding claw are moved in the first direction, and the two second holding claws are provided on the first holding claw. A holding portion for holding the work mounted on the stage between the 1 contact portion and the second contact portion provided on the second holding claw, and a second direction perpendicular to the first direction. A positioning unit for positioning the work at a predetermined position is provided, and after the work is positioned at a predetermined position in the second direction by the positioning unit, the holding unit has two first contact portions and the second contact portion. The work is held between the contact portion and the contact portion.

In the work holding method according to the present invention, at least one of the first holding claw and the second holding claw is moved in the first direction, and the two first contact portions provided on the first holding claw and the first holding claw are described. 2 In a method of holding a work placed on the stage with a second contact portion provided on a holding claw, the work is held at a predetermined position in a second direction perpendicular to the first direction. This is a method of holding the work between the two first contact portions and the second contact portion after positioning the work.

According to the present invention, the work can be held at three points without changing the orientation of the work.

Partial cutout perspective sectional view of the clamp device according to the embodiment of the present invention. An air circuit diagram showing a drive unit of the clamp device of FIG. Top view of the clamp device of FIG. 1 showing a state in which the work is placed on the stage. Top view of the clamp device of FIG. 1 showing a state in which the work is positioned. Top view of the clamp device of FIG. 1 showing a state in which the work is held. Top view of the clamp device according to the modified example of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(1) Clamp device 10
As shown in FIGS. 3 to 5, the clamp device 10 according to the present embodiment is a device that holds and fixes a substantially cylindrical work 1 such as a connector. As shown in FIG. 1, the clamp device 10 has a stage 20 on which the work 1 is placed, a holding portion 30 for holding and fixing the work 1 mounted on the stage 20, and a work mounted on the stage 20. It includes a positioning unit 40 that positions 1 at a predetermined position on the stage 20, a holding drive unit 50 that drives the holding unit 30, and a positioning drive unit 70 that drives the positioning unit 40.

In the present specification, the moving direction of the pair of holding claws 31 and 32 included in the holding portion 30 is the first direction D1, and the moving directions of the pair of holding claws 42 and 42 included in the positioning portion 40 are the second directions D2 and the first. The direction perpendicular to the one direction D1 and the second direction D2 is referred to as the vertical direction D3.

The stage 20 includes a plate-like body having light transmission such as a glass plate or an acrylic plate. A surface illumination device 22 that illuminates the entire stage 20 from below is provided on the lower side of the stage 20, and the illumination light emitted from the surface illumination device 22 passes through the transparent stage 20 and is placed on the stage 20. The work 1 is illuminated from below.

Plates 24 provided with openings 25 are stacked on the upper surface of the stage 20, and protective plates 26 are provided above the plates 24 at intervals.

The plate 24 is made of a plate-like body such as stainless steel that does not transmit light, and the stage 20 is exposed inside the opening 25 and the work 1 is placed on the plate 24. The opening 25 provided in the plate 24 has, for example, a circular shape in a plan view as shown in FIG. 3, and the work 1 is positioned so that the center of the work 1 is located at the center position C thereof.

The protective plate 26 covers and protects the tip portions of the holding claws 31 and 32 and the pair of holding claws 42 and 42 provided between the plate 24 and the holding claws 31 and 32 from above. At the center of the protective plate 26, an opening 27 is provided so as to vertically overlap with the opening 25 of the plate 24.

The opening 27 provided in the protective plate 26 has, for example, a substantially rectangular shape in a plan view as shown in FIG. 3, and the length of the side of the opening 27 is substantially the diameter of the opening 25 of the plate 24. It is provided in the same way.

Further, the protective plate 26 is provided with a pair of notches 28 penetrating the protective plate 26 at positions facing each other across the opening 27 (for example, a position facing the first direction D1 in FIG. 3). The notch 28 communicates with the opening 27, and the opening 27 extends in the direction in which the notch 28 faces.

The work 1 is placed on the stage 20 through the opening 25 of the plate 24 and the opening 27 of the protective plate 26. The work 1 placed on the stage 20 projects upward from the upper surface of the plate 24, and a pair of holding claws 42 and 42 of the positioning portion 40 and holding claws 31 and 32 of the holding portion 30 are provided on the outer peripheral portion of the protruding portion. Contact.

The positioning portion 40 includes a pair of holding claws 42, 42 provided so as to sandwich the opening 25 of the plate 24 in the second direction D2 and face each other. The pair of holding claws 42, 42 are provided between the plate 24 and the protective plate 26 in the vertical direction D3.

The pair of holding claws 42, 42 are connected to the positioning drive unit 70, and are connected to each other along the second direction D2 about a predetermined position inside the opening 25 (for example, the center position C of the opening 25). Move close to each other.

The pair of holding claws 42, 42 have a planar tip surface 43, 43 extending along the first direction D1 perpendicular to the second direction D2 at the tip thereof. The pair of holding claws 42, 42 have tip surfaces 43, 43 at positions outside the opening 27 and the notch 28 provided in the protective plate 26 as shown in FIG. There is) and a position that abuts on the outer peripheral surface of the work 1 mounted on the stage 20 (this position may be referred to as a positioning position), and the work 1 is moved close to and separated from each other along the second direction D2.

The tips of the pair of holding claws 42, 42 are located below the protective plate 26 at the second shelter position, and are protected by the protective plate 26 without being exposed upward from the opening 27 or the notch 28 of the protective plate 26. When the pair of holding claws 42, 42 move close to each other from the second retaining position and reach the positioning position, the tips of the pair of holding claws 42, 42 come into contact with the outer peripheral surface of the work 1. As a result, the pair of works 1 is located on a straight line L1 parallel to the first direction D1 passing through the center position C of the opening 25 of the plate 24 (this straight line is sometimes called the first straight line). The holding claws 42, 42 position the work 1 placed on the stage 20 in the second direction D2.

The holding portion 30 includes a first holding claw 31 and a second holding claw 32 provided so as to face each other with the opening 25 of the plate 24 sandwiched in the first direction D1. The first holding claw 31 and the second holding claw 32 are provided between the plate 24 and the protective plate 26 in the vertical direction D3, and in the present embodiment, they have the same height as the pair of holding claws 42, 42 of the positioning portion 40. Is located in.

The first holding claw 31 and the second holding claw 32 are connected to the holding drive unit 50, and the second direction D2 is centered on a predetermined position inside the opening 25 (for example, the center position C of the opening 25). They move close to each other along the first direction D1 perpendicular to. That is, the first holding claw 31 and the second holding claw 32 of the holding portion 30 move in a direction perpendicular to the moving direction of the pair of holding claws 42, 42 of the positioning portion 40.

Two first contact portions 33, 33 that come into contact with the outer peripheral surface of the work 1 are provided on the tip end side (second holding claw 32 side) of the first holding claw 31. The first contact portions 33, 33 are composed of a pair of inclined surfaces that are inclined so as to move away from the tip side toward the central portion (central portion in the width direction) of the first holding claw 31 in the second direction D2, and in a plan view. It has a substantially V-shape that is recessed in the direction away from the tip side. The pair of inclined surfaces forming the first contact portions 33, 33 are preferably provided symmetrically with respect to the first straight line L1 parallel to the first direction D1 passing through the center position C of the opening 25 of the plate 24. ..

The tip side (first holding claw 31 side) of the second holding claw 32 arranged so as to face the first holding claw 31 and the first direction D1 has a second plane formed along the second direction D2. The contact portion 34 is provided.

In such a holding portion 30, the pair of first contact portions 33, 33 of the first holding claw 31 and the second contact portion 34 of the second holding claw 32 are provided on the protective plate 26 as shown in FIG. The outer position of the opened opening 27 and the notch 28 (this position may be referred to as the first retreat position) and the position of contact with the outer peripheral surface of the work 1 placed on the stage 20 (this position is referred to as the holding position). (Sometimes), they move close to each other along the first direction D1.

The first contact portions 33, 33 and the second contact portion 34 are located below the protective plate 26 at the first retreat position, and are not exposed upward from the opening 27 or the notch 28 of the protective plate 26 and are not exposed upward. Protected by 26. When the first holding claw 31 and the second holding claw 32 move close to each other from the first retaining position and reach the holding position, the first holding claw 31 moves to the outer periphery of the work 1 at the two first contact portions 33, 33. The second holding claw 32 abuts on the surface, and the second holding claw 32 abuts on the outer peripheral surface of the work 1 at one second contact portion 34 to hold the work 1 at three points.

As shown in FIG. 2, the holding drive unit 50 includes an air cylinder mechanism 52 and an air supply means 53 that supplies air to the air cylinder mechanism 52. The air cylinder mechanism 52 includes a cylinder 54, a piston 55 slidably arranged in the cylinder 54, and a piston rod 56 connected to the piston 55.

The cylinder 54 has working chambers 54a and 54b formed on both sides of the piston 55 between the end walls 541 and 542, respectively. Further, supply / exhaust ports 544 and 545 communicating with the operating chambers 54a and 54b are formed on both end walls 541 and 542 of the cylinder 54, respectively. The piston rod 56 connected to the piston 55 slidably arranged in the cylinder 54 is arranged by inserting one end wall 541, and is arranged at the tip thereof via a rack and a pinion mechanism (not shown). The first holding claw 31 and the second holding claw 32 are connected so as to move close to each other.

The air supply means 53 for supplying air to the air cylinder mechanism 52 is provided in the air supply source 61, the supply pipe 62 connected to the air supply source 61, and the cylinder 54 constituting the air cylinder mechanism 52. The supply / exhaust pipes 63 and 64 connected to the exhaust ports 544 and 545, respectively, and the supply pipe 62 and the supply / exhaust pipe 63 or 64 are selectively communicated with each other. The electromagnetic control valve 65 is provided.

The air supply / exhaust pipe 63 connected to one air supply / exhaust port 544 is provided with a speed control valve 67 in which a check valve and a throttle valve are connected in parallel, and an air supply / exhaust pipe connected to the other air supply / exhaust port 545. A pressure reducing regular 68 and a speed control valve 69 are provided in series with the 64.

When the electromagnetic control valve 65 is degassed (OFF), the communication between the supply pipe 62 and the supply / exhaust pipes 63 and 64 is cut off.

When the electromagnetic control valve 65 urges (ON) the first electromagnetic solenoid 651, the supply pipe 62 and the air supply / exhaust pipe 63 communicate with each other, and the air supply / exhaust pipe 64 and the exhaust pipe 66 communicate with each other. As a result, the first holding claw 31 and the second holding claw 32 move apart from each other.

When the electromagnetic control valve 65 urges (ON) the second electromagnetic solenoid 652, the supply pipe 62 and the air supply / exhaust pipe 64 communicate with each other, and the air supply / exhaust pipe 63 and the exhaust pipe 66 communicate with each other. As a result, the first holding claw 31 and the second holding claw 32 move close to each other.

Like the holding drive unit 50, the positioning drive unit 70 includes an air cylinder mechanism 72 and an air supply means 73 that supplies air to the air cylinder mechanism 72. The air cylinder mechanism 72 includes a cylinder 74, a piston 75 slidably arranged in the cylinder 74, and a piston rod 76 connected to the piston 75.

The cylinder 74 has operating chambers 74a and 74b formed on both sides of the piston 75 between the end walls 741 and 742, respectively. Further, supply / exhaust ports 744 and 745 communicating with the operating chambers 74a and 74b are formed on both end walls 741 and 742 of the cylinder 74, respectively. The piston rod 76 connected to the piston 75 slidably arranged in the cylinder 74 is arranged by inserting one end wall 741 and is arranged at the tip thereof via a rack and a pinion mechanism (not shown). The pair of holding claws 42, 42 are connected so as to move close to each other.

The air supply means 73 for supplying air to the air cylinder mechanism 72 is provided in the air supply source 61, the supply pipe 62 connected to the air supply source 61, and the cylinder 74 constituting the air cylinder mechanism 72. The air supply / exhaust pipes 83 and 84 connected to the exhaust ports 744 and 745, respectively, and the supply pipe 62 and the air supply / exhaust pipe 83 or 84 are selectively connected to each other. The electromagnetic control valve 85 is provided.

The air supply / exhaust pipe 83 connected to one air supply / exhaust port 744 is provided with a speed control valve 87 in which a check valve and a throttle valve are connected in parallel, and an air supply / exhaust pipe connected to the other air supply / exhaust port 745. The pressure reducing regular 88 and the speed control valve 89 are provided in series with the 84.

When the electromagnetic control valve 85 is degassed (OFF), the communication between the supply pipe 62 and the supply / exhaust pipes 83 and 84 is cut off.

When the electromagnetic control valve 85 urges (ONs) the first electromagnetic solenoid 851, the supply pipe 62 and the air supply / exhaust pipe 83 communicate with each other, and the air supply / exhaust pipe 84 and the exhaust pipe 66 communicate with each other. As a result, the pair of holding claws 42, 42 move apart from each other.

When the electromagnetic control valve 85 urges (ON) the second electromagnetic solenoid 852, the supply pipe 62 and the air supply / exhaust pipe 84 communicate with each other, and the air supply / exhaust pipe 83 and the exhaust pipe 66 communicate with each other. As a result, the pair of holding claws 42, 42 move close to each other.

(2) Operation of Clamping Device 10 Next, an operation in which the clamping device 10 as described above holds and fixes the work 1 will be described.

First, as shown in FIG. 3, the first holding claw 31 and the second holding claw 32 of the holding portion 30 are located at the first retaining position, and the pair of holding claws 42, 42 of the positioning portion 40 are located at the second retaining position. In the positioned state, the work 1 is placed on the stage 20 through the opening 25 of the plate 24 and the opening 27 of the protective plate 26.

When the work 1 is placed on the stage 20, the electromagnetic control valve 85 of the positioning drive unit 70 urges (ONs) the second electromagnetic solenoid 852, whereby a pair of pairs are centered on the center position C of the opening 25. The holding claws 42, 42 are moved close to each other so that the tip surfaces 43, 43 of the pair of holding claws 42, 42 are brought into contact with the outer peripheral surface of the work 1 placed on the stage 20. As a result, the work 1 is positioned in the second direction D2 so that the center of the work 1 is located on the first straight line L1. When the planar shape of the work 1 is circular as in the present embodiment, the work 1 is arranged symmetrically with respect to the first straight line L1 (see FIG. 4).

When the work 1 is positioned in the second direction D2, the electromagnetic control valve 85 of the positioning drive unit 70 urges (ON) the first electromagnetic solenoid 851 to move the pair of holding claws 42, 42 to the second retracting position. Move to.

After that, the electromagnetic control valve 65 of the holding drive unit 50 urges (ON) the second electromagnetic solenoid 652 to move the first holding claw 31 and the second holding claw 32 in the first standby position close to each other. , The two first contact portions 33, 33 provided on the first holding claw 31 and the second contact portion 34 provided on the second holding claw 32 are brought into contact with the outer peripheral surface of the work 1. As a result, the work 1 is held between the first holding claw 31 and the second holding claw 32 in a positioned state so that the center of the work 1 coincides with the center position C of the opening 25.

Then, a predetermined step is executed in a state where the work 1 is held and fixed by the first holding claw 31 and the second holding claw 32 of the holding portion 30 so that the center of the work 1 coincides with the center position C of the opening 25. do. Various steps can be executed while the work 1 is held and fixed by the holding portion 30. For example, when the work 1 is a connector, the contact pin is press-fitted into a predetermined position of the connector.

Then, when the predetermined step is completed, the electromagnetic control valve 65 of the holding drive unit 50 urges (ON) the first electromagnetic solenoid 651, and the first holding claw 31 and the second holding claw 32 are placed in the first retreat position. Move to.

Then, the work 1 is taken out from the stage 20, another work 1 is placed on the stage 20 as needed, and the work 1 is positioned again by the positioning unit 40, and the work 1 is held and fixed by the holding unit 30. The execution of the process of is repeated.

(3) Effect In the clamp device 10 of the present embodiment, the work 1 is positioned at a predetermined position in the second direction D2 by the positioning unit 40, and then the work 1 is held by the holding unit 30 so that the work 1 is provided on the first holding claw 31. When the work 1 is held between the two first contact portions 33, 33 and the second contact portion 34 provided on the second holding claw 32, the work 1 moves around the axis in the vertical direction D3. It can suppress the rotation.

In particular, in the present embodiment, the two first contact portions 33 provided on the first holding claw 31 are provided symmetrically with respect to the first straight line L1 and before the work 1 is held by the holding portion 30. The work 1 is positioned symmetrically with respect to the first straight line L1 by the positioning unit 40. As a result, when the work 1 is held between the first holding claw 31 and the second holding claw 32, the work 1 abuts on the two first contact portions 33, 33 of the first holding claw 31 at the same time. , The work 1 can be held between the two first contact portions 33, 33 and the second contact portion 34 without rotating the work 1 about the axis in the vertical direction D3.

Further, in the present embodiment, when the work 1 is placed on the stage 20 or the work 1 is taken out from the stage 20, the first contact portions 33, 33 and the second contact portions 34 of the holding portion 30 and the positioning are performed. Since the tip surfaces 43, 43 of the pair of holding claws 42, 42 of the portion 40 are covered above by the protective plate 26, the first contacting portions 33, 33 and the second contacting portion 34 and the pair of holding claws are covered. It is possible to prevent the work 1 from accidentally colliding with the tip surfaces 43 and 43 of the 42 and 42.

Moreover, in the present embodiment, since the notch 28 communicating with the opening 27 is provided at a position facing the opening 27 of the protective plate 26, when the worker puts the work 1 in and out of the stage 20. In addition, the finger holding the work 1 is less likely to come into contact with the protective plate 26, which makes it easier to work.

Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

For example, in the above embodiment, the following modification examples 1 to 3 can be applied.

(Change example 1)
In the above embodiment, the air cylinder mechanisms 52 and 72 are used as the holding drive unit 50 and the positioning drive unit 70 for driving the holding unit 30 and the positioning unit 40, but the ball screw is rotationally controlled by a motor such as a stepping motor. The movement of the holding unit 30 and the positioning unit 40 can be controlled by various actuators such as a holding unit 30 fixed to a sliding base screwed to a ball screw and a linear actuator that drives the positioning unit 40.

When a linear actuator that drives the holding portion 30 and the positioning portion 40 by controlling the rotation of the motor is adopted, the position where the pair of holding claws 42, 42 of the positioning portion 40 abuts on the outer peripheral surface of the work 1 is detected by the position of the encoder or the like. Even if it is detected by a device, the size and type of the work 1 placed on the stage 20 are detected based on the detection result, and the movement of the first holding claw 31 and the second holding claw 32 of the holding portion 30 is controlled. good.

Specifically, the encoder detects the moving distance from the second retaining position to the position where the pair of holding claws 42, 42 abuts on the outer peripheral surface of the work 1, and the size of the work 1 is detected from the result.

Information on the size of the work 1 and the holding position is stored in the clamp device 10 in association with each other in advance, and when the size of the work 1 is detected, the corresponding holding position is read. Then, after moving the first holding claw 31 and the second holding claw 32 at a high speed from the first retaining position to a predetermined position before reaching the holding position at the first speed, the first holding position is moved from the first speed to the holding position. Move at low speed. As a result, it is possible to suppress the impact when the first holding claw 31 and the second holding claw 32 come into contact with the work 1 while shortening the time until the work 1 is held.

Further, since the first holding claw 31 and the second holding claw 32 can be stopped at appropriate positions according to the size of the work 1, the work 1 is excessively pushed by the first holding claw 31 and the second holding claw 32. The work 1 is not held in an inclined state or the work 1 is not damaged. Further, it is possible to control the load when the work 1 is held and fixed by the first holding claw 31 and the second holding claw 32.

(Change example 2)
In the above embodiment, the two first contact portions 33, 33 provided at the tip of the first holding claw 31 are provided in a V shape. For example, as illustrated in FIG. 6, the first straight line L1 is provided. Various shapes can be adopted as the contact portion, for example, the protrusions 133 and 133 provided on both sides of the second direction D2 that are sandwiched therein are used as the first contact portion that contacts the work 1. Further, in the above-described embodiment, the two contact portions are provided symmetrically with respect to the first straight line L1, but the two contact portions may be provided asymmetrically with respect to the first straight line L1. In that case, when the work 1 is held between the first holding claw 31 and the second holding claw 32, the shape of the work 1 is adjusted so that the work 1 abuts on the two first contact portions at the same time. It is preferable to provide the first contact portion in the shape.

10 ... Clamp device, 20 ... Stage, 22 ... Surface lighting device, 24 ... Plate, 25 ... Opening, 26 ... Protective plate, 27 ... Opening, 28 ... Notch, 30 ... Holding part, 31 ... First holding claw , 32 ... 2nd holding claw, 33 ... 1st contact part, 34 ... 2nd contact part, 40 ... positioning part, 42 ... holding claw, 43 ... tip surface, 50 ... holding drive part

Claims (7)

The stage on which the work is placed and
By moving at least one of the first holding claw and the second holding claw in the first direction, the two first contact portions provided on the first holding claw and the second contact portion provided on the second holding claw are provided. A holding portion that holds the work placed on the stage between the contact portion and the holding portion.
A positioning unit for positioning the work at a predetermined position in the second direction perpendicular to the first direction is provided.
A clamp device in which the holding portion holds the work between two first contact portions and the second contact portion after the work is positioned at a predetermined position in the second direction by the positioning portion. The clamp device according to claim 1, wherein the positioning unit positions the work so that the two first contact portions come into contact with the work at the same time when the holding portion holds the work. The clamp device according to claim 1 or 2, wherein the two first contact portions are provided symmetrically with respect to an axis of symmetry along the first direction. The clamp device according to any one of claims 1 to 3, wherein the positioning unit presses the work from both sides in the second direction to position the work at a predetermined position in the second direction. When the positioning unit positions the work, information on the size of the work is acquired, and information is obtained.
The clamp device according to any one of claims 1 to 4, wherein the holding portion controls the movement of the first holding claw and the second holding claw based on the acquired information to hold the work. A protective plate provided above the first holding claw and the second holding claw and an opening provided in the protective plate are provided.
When the work is placed on the stage, the first holding claw and the second holding claw are located outside the opening, and the first holding claw and the second holding claw are inside the opening. The clamp device according to any one of claims 1 to 5, which projects to and holds the work. By moving at least one of the first holding claw and the second holding claw in the first direction, the two first contact portions provided on the first holding claw and the second contact portion provided on the second holding claw are provided. In the method of holding the work that holds the work placed on the stage with the contact part,
A method of holding a work that holds the work between two first contact portions and the second contact portion after positioning the work at a predetermined position in a second direction perpendicular to the first direction.

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