JP2009220244A - Rocking opening/closing chuck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve durability by reducing the sliding resistance to gripping fingers, to provide a high gripping force by a small-sized piston, to miniaturize a chuck itself, and to provide the high gripping force by opening/closing the gripping fingers by a multi-stage movement. <P>SOLUTION: Operation portions are pressed by ball members, which is in slide contact with a first sloping part of a cam member moving along the operation of an operation member, in the mutually separating direction against the elastic force of elastic member to rock the gripping fingers to a position where gripping portions can grip a work, and consecutively the operation portions are pressed by the ball members coming into slide contact with a second sloping part, in the mutually further separating direction to rock the gripping fingers to a position where the griping portions grip the work. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a swing opening / closing chuck that is attached to a robot hand and grips a workpiece, or is attached to a movable body of a resin molded product take-out machine and grips a runner of a resin molded product.

  For example, in the swing opening / closing chuck shown in Patent Document 1, in the swing opening / closing chuck for a robot hand in which the chuck closing operation is performed by fluid pressure and the opening operation is performed by a spring, the sectional shape of the tip is formed inside the casing. Comprises a V-shaped piston, a guide rod and a spring are arranged inside the piston so as to act coaxially with the piston, and a pair of fingers provided with contact portions respectively contacting the piston and the guide rod, The closing operation is performed by moving the tip of the finger in the closing direction by pushing the V part of the piston in contact with the finger by the fluid pressure. The opening operation is performed by releasing the fluid pressure, and the guide rod is moved by the spring force. The finger tip is moved in the opening direction by being pushed out while contacting Constructed.

  However, in the above swing opening / closing chuck, the V portion of the piston is directly slidably contacted with the finger to close the finger, so that the sliding resistance between the two becomes large and the contact portion is easily worn. The durability was bad. In addition, since the piston is reciprocated with a force against the sliding resistance, it is necessary to use a high-torque operating member, which causes a problem that the chuck itself is increased in size and weight.

In particular, in a chuck to be mounted on a resin molded product take-out machine, it is necessary to shorten the molded product take-out cycle and to enter the narrow space formed between a pair of molds to execute the take-out operation. As a result, downsizing and weight reduction are required.

Further, when the piston is not operated, a guide rod biased by a spring must be provided for the piston in order to keep the pair of fingers open, which has a problem that the piston structure becomes complicated. Furthermore, because the finger is slidably contacted with the V portion of the piston and the finger is opened and closed in one step, a torque greater than the gripping torque is required to obtain a strong gripping force in consideration of the sliding resistance against the finger. It is necessary to use an actuating member having
JP 2008-6549 A

The problem to be solved is that the piston is brought into direct contact with the gripping fingers to open and close, so that the sliding resistance between them increases and the durability deteriorates. Further, in order to open and close the gripping fingers with a strong gripping force against a large sliding resistance, a large fluid pressure actuating member must be used, and the size of the chuck itself is increased. Since the gripping fingers are opened and closed in a single step, a strong gripping force cannot be obtained.

The present invention has a gripping portion at the front end portion and an operation portion at the rear end portion, and the gripping portions are separated from each other by a pair of gripping fingers supported so as to be swingable at the intermediate portion. An elastic member that swings in the direction, a cam member provided with a first inclined portion having a large inclination angle and a second inclined portion having a small inclination angle on the distal end side, an operating member that moves the cam member, and an elastic member And a ball member that abuts on the tip of the cam member by the actuating portion biased by the actuating member. After pressing the gripping fingers against the elastic force in directions away from each other and swinging the gripping fingers to a position where the gripping portion can grip the workpiece, the operation portion is subsequently moved by the ball member slidably contacting the second inclined portion. Further away from each other The pressure and gripping fingers, the grip portion is characterized by swinging to a position for gripping the workpiece.

The present invention can improve the durability by reducing the sliding resistance with respect to the gripping fingers. A high gripping force can be obtained with a small piston, and the chuck itself can be downsized. A high gripping force can be obtained by opening and closing the gripping fingers in a multistage operation.

According to the present invention, the gripping fingers are pressed by pressing the operating portions in directions away from each other against the elastic force of the elastic members by the ball members slidingly contacting the first inclined portions of the cam members that move with the operation of the operating members. Then, after swinging to a position where the workpiece can be gripped by the gripping portion, the ball member is then slidably brought into contact with the second inclined portion and the operating portion is further pressed away from each other so that the gripping finger The best mode is to swing to the position where the workpiece is gripped.

The present invention will be described below with reference to the drawings showing embodiments.
As shown in FIGS. 1 and 3, a pair of gripping fingers 5 are arranged in the front portion of the casing 3 of the swing opening / closing chuck 1. Each gripping finger 5 is provided with a gripping portion 5a on the tip end side and an operating portion 5b on the other end side. Each gripping finger 5 is pivotally supported so that an intermediate portion near the operating portion 5b swings on a support shaft 7 attached to the casing 3, and when the gripping portions 5a are swung in a direction approaching each other, The gripping surfaces of the gripping parts 5a are opposed to each other with a minute interval.

An elastic member 9 such as a compression spring or rubber is mounted between the gripping fingers 5 closer to the gripping portion 5a than the support shaft 7, and the gripping portions 5a are always separated from each other by the elastic force of the elastic member 9. The side, and hence the operating parts 5b, are urged so as to swing toward each other.

An operating member 11 such as an air cylinder or an electric motor having an axis in a direction coinciding with the central axis of the swing opening / closing chuck 1 is provided at the rear portion of the casing 3 (the figure shows an example in which a cylinder is used as the operating member). Is installed. A piston 13 is supported in the actuating member 11 so as to slide, and the piston 13 is urged to move to the right in the axial direction shown in FIG. 2 by a built-in compression spring 15. The piston 13 on the gripping finger 5 side is provided with a cam member 17 such as a cam shaft. The cam member 17 may have either a structure integrally formed with the piston 13 or a structure in which a cam member 17 which is a member different from the piston 13 is fixed to the piston 13.

  A small-diameter shaft portion 17a, a first inclined shaft portion 17b, and a second inclined shaft portion 17c are formed at the distal end portion of the cam member 17 from the distal end toward the rear. The small-diameter shaft portion 17a is formed to have a predetermined outer diameter and axial length, and is positioned and supported between a pair of ball members 19 described later when the swinging open / close chuck 1 is not operated. The first inclined shaft portion 17a is formed on an inclined outer peripheral surface that gradually increases in diameter so as to incline at a large angle with respect to the axial direction from the boundary with the small diameter shaft portion 17a and extends with a predetermined axial width. The second inclined shaft portion 17c is longer than the axial length of the first inclined shaft portion 17b while gradually increasing in diameter so as to be inclined at a small angle with respect to the axial direction from the boundary with the first inclined shaft portion 17b. It is formed on the inclined outer peripheral surface extending with the axis width.

  In the casing 3 corresponding to the small diameter shaft portion 17a of the cam member 17 moved to the right in the axial direction shown in FIG. 2 and the operating portion 5b of each gripping finger 5, guide recesses 3a extending on both sides in the direction orthogonal to the axis are formed. In each guide recess 3a, a ball member 19 is arranged so as to be movable in the direction perpendicular to the axis. Each ball member 19 is pressed so as to come into contact with the small-diameter shaft portion 17a of the cam member 17 by the operating portion 5b biased in a direction approaching each other by the elastic force of the elastic member 9.

  A gripping detector 21 such as a proximity switch or a microswitch is attached to the gripping part 5a of one gripping finger 5, and each gripping finger 5 is closed to run a workpiece or a resin molded product runner (hereinafter referred to as a "runner"). These are collectively referred to as a workpiece W.) When a workpiece is gripped, an electrical signal is output to detect that the workpiece W is gripped.

Next, the operation of the swing opening / closing chuck 1 configured as described above will be described.
When the workpiece is not gripped, the piston 13 is moved to the right in the axial direction shown in FIG. 2 by the elastic force of the compression spring 15. In this state, the pair of gripping fingers 5 are in an open state by swinging in the direction in which the gripping portions 5 a are separated from each other about the support shaft 7 by the elastic force of the elastic member 9. Further, the operating portion 5 b of the gripping finger 5 swings in a direction approaching each other by the elastic force of the elastic member 9 and presses the ball member 19 so as to be in pressure contact with the small diameter shaft portion 17 a of the cam member 17.

  Next, in order to grip the workpiece W positioned between the gripping portions 5a of the gripping fingers 5, a fluid having a required pressure (in the positive pressure chamber of the operating member 11 with the workpiece W positioned between the gripping portions 5a) ( (Air, hydraulic oil) is supplied to move the piston 13 to the left in the axial direction at a constant speed and torque against the elastic force of the compression spring 15. As a result, the ball member 19 moves in a direction away from each other in the direction perpendicular to the axis by slidingly contacting the first inclined shaft portion 17b and the second inclined shaft portion 17c of the cam member 17 moving integrally with the piston 13, The operating parts 5b that are in contact with the outer peripheral surface are moved away from each other to swing the gripping fingers 5 in a direction in which the gripping parts 5a approach each other against the elastic force of the elastic member 9. (See Figure 4)

  At the initial stage of sliding contact of the ball member 19 with the cam member 17, the first inclined shaft portion 17b with which the ball member 19 slides is inclined at a large angle with respect to the axial direction. Then, each gripping finger 5 is swung at a large swing angle. At this time, since the first inclined shaft portion 17b is inclined at a large angle with respect to the axial direction, the sliding contact resistance of the ball member 19 is increased, but each gripping finger 5 is not gripped with respect to the workpiece W. Therefore, since there is no load, each gripping finger 5 can be swung at a large angle in a short time by the torque of the actuating member 11.

Then, as shown in FIG. 5, when the sliding contact surface of the ball member 19 moves from the first inclined shaft portion 17b to the second inclined shaft portion 17c as the cam member 17 moves with respect to the left side in the axial direction, the ball member 19 Along with the sliding contact with the second inclined shaft portion 17 c, the gripping fingers 5 are resisted against the elastic force of the elastic members 9 by pressing the operating portions 5 b that are further moved outward in the direction orthogonal to the axis and abutting outward. The workpiece W is gripped by swinging in a direction in which the gripping portions 5a are closer to each other. At this time, since the inclination angle of the second inclined shaft portion 17c with respect to the axial direction is smaller than that of the first inclined shaft portion 17b and the sliding contact resistance of the ball member 19 with respect to the second inclined shaft portion 17c is small, each gripping finger 5 Is reliably swung by the torque of the actuating member 11, and the workpiece W is gripped by a gripping force corresponding to the torque.

In order to release the gripping of the workpiece W by the gripping fingers 5, the supply of fluid to the operating member 11 is interrupted and discharged to bring the piston 13 into the position shown in FIG. 2 by the elastic force of the compression spring 15. return. Thus, as the cam member 17 moves backward, each ball member 19 moves in a direction closer to each other in the direction orthogonal to the axis by slidingly contacting the second inclined shaft portion 17c, the first inclined shaft portion 17b, and the small diameter shaft portion 17a in this order. The pressure on the operating part 5b is released. Then, the gripping of the workpiece W is released by urging and swinging each gripping finger 5 by the elastic force of the elastic member 9 in a direction in which the gripping portions 5a are separated from each other, and hence in a direction in which the operating portions 5a are close to each other.

In this embodiment, when gripping the workpiece W, each gripping finger 5 is moved at a larger swing angle with respect to the first inclined shaft portion 17b in the initial movement of the cam member 17, and thereafter the second inclined shaft portion 17c. By swinging at a smaller swing angle, the workpiece W can be reliably gripped with a gripping force corresponding to the torque of the actuating member 11. Moreover, even if it is the operating member 11 of low torque, the gripping force according to this torque can be obtained, and the apparatus itself can be reduced in size and weight.

In the above description, the first inclined shaft portion 17b and the second inclined shaft portion 17c having different inclination angles with respect to the axial direction are integrally formed on the distal end side of the cam member 17 so as to be continuous, as shown in FIG. In addition, a flat portion 51a having a constant width on the tip side, a first cam surface 51b having a large inclination angle with respect to the axial direction, and a second cam surface 51c having a small inclination angle with respect to the axial direction as compared with the first cam surface 51b are successively arranged. A cam member may be configured by the formed cam plate 51, and the cam plate 51 may be provided integrally or separately with respect to the piston 13.

As the piston 13 moves, the cam plate 51 moves the ball member 19 slidably contacting the first cam surface 51b and the second cam surface 51c at different speeds and swings each gripping finger 5 to grip the workpiece. The workpiece W can be reliably gripped with a predetermined gripping force corresponding to the torque of the operating member 11 while shortening the time required for the operation.

It is a perspective view which shows the whole rocking | fluctuation opening / closing chuck | zipper. It is sectional drawing which shows the structure of a rocking | fluctuation opening / closing chuck | zipper. It is explanatory drawing which expands and shows the front-end | tip part of a cam member. It is explanatory drawing which shows the sliding contact state of the ball member with respect to a 1st inclination shaft part. It is explanatory drawing which shows the sliding contact state of the ball member with respect to a 2nd inclination shaft part. It is explanatory drawing which shows the example of a change of a cam member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Oscillating open / close chuck 3 Casing 5 Gripping finger 5a Gripping part 5b Actuating part 7 Support shaft 9 Elastic member 11 Actuating member 13 Piston 15 Compression spring 17 Cam member 17a Small diameter shaft part 17b First inclined shaft part 17c Second inclined shaft part 19 Ball member

Claims (6)

A pair of gripping fingers having a gripping portion at the front end portion and an operating portion at the rear end portion and supported so as to be swingable at the intermediate portion;
An elastic member that swings each gripping finger in a direction in which the gripping portions are separated from each other;
A cam member in which a first inclined portion having a large inclination angle and a second inclined portion having a small inclination angle are sequentially provided on the distal end side;
An actuating member for moving the cam member;
A ball member that comes into contact with the tip of the cam member by the operating portion biased by the elastic member;
With
The gripping finger is moved by the gripping portion by pressing the operation portion in a direction away from each other against the elastic force of the elastic member by the ball member slidingly contacting the first inclined portion of the cam member moving with the operation of the operation member. Position where the gripping part grips the workpiece by swinging to a position where the workpiece can be gripped, and then pressing the operating part further away from each other by the ball member slidingly contacting the second inclined part. Swing open / close chuck that swings to the right. 2. The cam member according to claim 1, wherein the cam member is a shaft member, and is continuous with a first inclined portion formed of an outer peripheral surface inclined at a large inclination angle with respect to the axis at a distal end portion of the shaft member and a boundary between the first inclined portions. A swing opening / closing chuck provided with a second inclined portion comprising an outer peripheral surface inclined at an inclination angle smaller than the inclination angle of the first inclined portion. 2. The cam member according to claim 1, wherein the cam member is a plate member, and is continuous from a tapered surface-shaped first inclined portion inclined at a large inclination angle with respect to a longitudinal direction from a boundary of the first inclined portion. And a swing opening / closing chuck provided with a second inclined portion comprising a tapered surface inclined at an inclination angle smaller than the inclination angle of the first inclined portion. 2. The swing opening / closing chuck according to claim 1, wherein the cam member is integrally formed with the operating member. 2. The swing opening / closing chuck according to claim 1, wherein the cam member is a separate member from the operating member. 2. The swing opening / closing chuck according to claim 1, wherein one gripping finger is provided with a detector, and when the gripping finger grips the workpiece, an electrical signal is output to detect the workpiece gripping.

Images