Support point opening and closing type air chuck

Abstract

SOLUTION: To provide a fulcrum opening / closing type air chuck 10 comprising: porous bodies 94, 96, 110 being attached to a body 12 and contacting a finger 80, in the fulcrum opening / closing type air chuck, purge air is discharged outside through the porous bodies.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a fulcrum-opening / closing type air chuck having a pair of rotating gripping members, and more particularly to a fulcrum-opening / closing type air chuck having a dustproof function. [Background technology]

[0002] A fulcrum-opening type air chuck that grips a workpiece using a pair of gripping members that rotate around an axis has been known. For example, Patent Document 1 describes a chuck device in which a pair of gripping members that are rotatably supported on a body are driven by a cylinder mechanism.

[0003] The chuck device of Patent Document 1 prevents dust from entering the inside of the body by attaching a cover member to one end of the body. Specifically, a first curved portion provided on the rotating portion of the gripping member is brought into contact with a corner of the body, and a second curved portion provided on the rotating portion of the gripping member is brought into contact with a recess in the cover member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-80888 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in order to bring the rotating part of the gripping member into contact with the body and the cover member and eliminate any gaps, the dimensional precision of each component must be extremely high. Furthermore, if we try to achieve complete contact with no gaps, the sliding resistance when the gripping member rotates will increase.

[0006] One possible dust prevention measure is to attach a rubber dust cover to the body to cover the outside of the gripping member. However, unlike the gripping member of a parallel opening / closing type air chuck, which slides the gripping member, the gripping member of a fulcrum opening / closing type air chuck has a large range of movement. Therefore, to prevent the dust cover from coming into contact with the gripping member and being torn, a large dust cover is required, which increases the size of the device.

[0007] Another possible dust prevention measure is to place a rubber seal such as a gasket between the gripping member and the body, but using a rubber seal increases the sliding resistance when the gripping member rotates.

[0008] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0009] The present invention is a fulcrum-type air chuck in which a pair of fingers are rotatably supported around a rotary support shaft attached to a body, and a drive unit for driving the pair of fingers to open and close is disposed inside the body. This fulcrum-type air chuck has a porous body attached to the body and in contact with the fingers, and purging air passes through the porous body and is discharged to the outside. [Effects of the Invention]

[0010] The fulcrum opening / closing type air chuck according to the present invention is provided with a porous body attached to the body and in contact with the fingers, and purging air passes through the porous body and is discharged to the outside. This prevents dust from entering the body without increasing the sliding resistance of the fingers. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of a fulcrum opening / closing type air chuck according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of the fulcrum opening / closing type air chuck of FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a view showing a state in which the first porous body of the fulcrum opening / closing type air chuck of FIG. 1 is attached. [Figure 6] 6 is a perspective view of the second porous body of the fulcrum opening / closing type air chuck of FIG. 1. FIG. [Figure 7] 7 is a perspective view of a third porous body of the fulcrum opening / closing type air chuck of FIG. [Figure 8] FIG. 8 is a view showing a state in which the third porous body of the fulcrum opening / closing type air chuck of FIG. 1 is attached. [Figure 9] FIG. 9 is a diagram showing the flow of purge air in the fulcrum opening / closing type air chuck of FIG. [Figure 10] FIG. 10 is a view corresponding to FIG. 3 when a pair of fingers of the fulcrum opening / closing type air chuck of FIG. 1 is open. [Figure 11] FIG. 11 is a view corresponding to FIG. 3 when a pair of fingers of the fulcrum opening / closing type air chuck of FIG. 1 are closed. DETAILED DESCRIPTION OF THE INVENTION

[0012] As shown in Figures 1 to 4, a fulcrum opening / closing type air chuck 10 according to an embodiment of the present invention includes a body 12, a pair of fingers 80, a drive unit 58, and first to third porous bodies 94, 96, 110. The pair of fingers 80 are rotatably supported by the body 12. The drive unit 58 includes a piston 60 and a drive rod 70 integrally connected to the piston 60, and is disposed inside the body 12. The pair of fingers 80 are driven to open and close by the drive unit 58. In the following description, when terms related to up and down are used, they refer to directions in Figure 3 for convenience and do not limit the actual arrangement of components, etc.

[0013] The body 12 includes a main body 14 and an end plate 48. The end plate 48 is attached to the upper end of the main body 14 by a screw member 52. The rectangular pillar-shaped main body 14 has a cylinder bore 16 therein, and a piston 60 is slidably disposed in the cylinder bore 16. The lower end of the cylinder bore 16 is closed by a cap 54. The cylinder chamber formed by the cylinder bore 16 is divided into a first pressure chamber 18 above the piston 60 and a second pressure chamber 20 below the piston 60. The main body 14 has a first port 22 that supplies and exhausts air to and from the first pressure chamber 18 and a second port 24 that supplies and exhausts air to and from the second pressure chamber 20.

[0014] The main body 14 is cut out parallel to the wide side surface 30 above the cylinder bore 16, from one of the pair of narrow side surfaces 34 to the other. That is, the main body 14 has a pair of side walls 28 above the cylinder bore 16. Reference numeral 47 denotes an attachment hole for attaching the body 12 to a conveying device or the like (not shown).

[0015] A piston packing 62, a magnet 64, and a wear ring 66 are attached to the outer periphery of the piston 60. The piston packing 62 seals between the first pressure chamber 18 and the second pressure chamber 20. The wide side surface 30 of the main body 14 has a sensor groove 32. The magnetic flux of the magnet 64 can be detected by a magnetic sensor (not shown) attached to the sensor groove 32. A damper 68 is attached to the upper end of the piston 60. The damper 68 absorbs the impact when the piston 60 moves to the upper end.

[0016] The drive rod 70 is inserted into a bushing 72 attached to the cylinder bore 16 and is supported so as to be able to move up and down. A rod packing 74 is attached to the upper end of the cylinder bore 16, making sliding contact with the drive rod 70. The rod packing 74 keeps the first pressure chamber 18 airtight. A sealant 56 is attached to the outer periphery of the cap 54, keeping the second pressure chamber 20 airtight from the outside. The drive rod 70 extends upward from the cylinder bore 16. The upper end of the drive rod 70 is provided with a pair of arms 76 facing each finger 80. A cylindrical rolling element 78 is rotatably supported at the tip of each arm 76.

[0017] Each finger 80 is composed of a fan-shaped rotating portion 82 and an elongated gripping portion 92. The rotating portion 82 and the gripping portion 92 have a constant width W0. The rotating portion 82 is disposed between a pair of side walls 28 of the main body 14. A rotating support shaft 40 is attached across the pair of side walls 28 of the main body 14, and the rotating support shaft 40 is inserted into a bushing 88 attached to the center of the rotating portion 82. This supports the finger 80 so that it can rotate around the rotating support shaft 40.

[0018] The rotating portion 82 has a first curved surface 84 that faces the end plate 48 and a second curved surface 86 that faces a fitting recess 42 of the main body 14, which will be described later. The first curved surface 84 and the second curved surface 86 each have a constant radius of curvature about the axis of the rotating support shaft 40. The radius of curvature of the first curved surface 84 is larger than the radius of curvature of the second curved surface 86. The rotating portion 82 also has two end faces that face the side wall 28 of the main body 14. The end faces of the rotating portion 82 are perpendicular to the axis of the rotating support shaft 40. The gripping portion 92 extends radially outward from one circumferential end of the first curved surface 84 of the rotating portion 82.

[0019] The rotating portion 82 has a groove 90 that extends to a predetermined depth from the other circumferential end of the first curved surface 84. The rolling element 78 supported by the arm portion 76 of the drive rod 70 is disposed in the groove 90 of the rotating portion 82 and is able to move within the groove 90 while rolling. As a result, the linear movement of the drive rod 70 in the vertical direction is converted into the rotational movement of the fingers 80. When the drive rod 70 moves upward, the pair of fingers 80 rotates in a direction that opens the pair of gripping portions 92, and when the drive rod 70 moves downward, the pair of fingers 80 rotates in a direction that closes the pair of gripping portions 92.

[0020] The end plates 48 have cutouts 50 at both ends that serve as paths for the gripping portions 92 when the fingers 80 rotate. The narrow side surfaces 34 of the main body 14 have openings 36 that open between the pair of side walls 28. The rotating portions 82 of the fingers 80 and the first to third porous bodies 94, 96, 110 prevent the interior of the body 12 from being directly connected to the outside through the openings 36 of the main body 14 and the cutouts 50 of the end plates 48. In other words, a purge air storage space 38 that is isolated from the outside is formed above the cylinder bore 16.

[0021] The first to third porous bodies 94, 96, and 110 are made of a lube-retainer, which is a fiber composite. However, the first to third porous bodies 94, 96, and 110 are not impregnated with a lubricant. Because the first to third porous bodies 94, 96, and 110 have gaps inside, they cannot by themselves prevent fine dust from entering the interior. However, by performing air purging, which will be described later, it is possible to prevent fine dust from entering from the outside.

[0022] The first to third porous bodies 94, 96, 110 that come into contact with the fingers 80 have low deformation resistance and are easily deformed. In order to reliably fill the gaps between the first to third porous bodies 94, 96, 110 and the fingers 80, even if the first to third porous bodies 94, 96, 110 are brought into contact with the fingers 80 with a predetermined pressure, the resistance (sliding resistance) when the fingers 80 move is small. In this embodiment, the first to third porous bodies 94, 96, 110 are made of lube-retainers, but they may also be made of felt or sponge.

[0023] As shown in FIG. 5, the first porous body 94 is formed in the shape of a long, narrow rectangular plate having a constant width W1. The first porous body 94 is attached to the underside of the end plate 48 using, for example, an adhesive. The width W1 of the first porous body 94 is equal to or slightly larger than the width W0 of the rotating portion 82 of the finger 80. Throughout the entire rotation range of the finger 80, the first curved surface 84 of the rotating portion 82 of the finger 80 contacts the end of the first porous body 94 in the longitudinal direction (see FIG. 3). The portion of the first porous body 94 that contacts the first curved surface 84 is pressed by the first curved surface 84 and deformed.

[0024] As shown in FIG. 6 , the second porous body 96 has a long, thin, plate-like base 98 and a pair of step portions 106 bent in an L-shape from both ends of the base 98. The base 98 has a first hole 100 at the center of its length, through which the drive rod 70 is inserted. The base 98 also has a second hole 102 at one end of its length, which serves as a passage for purge air. The base 98 has a pair of protrusions 104 protruding on both sides from the vicinity of the first hole 100. Before the drive rod 70 is inserted into the first hole 100, the inner diameter of the first hole 100 is smaller than the outer diameter of the drive rod 70. In other words, when the drive rod 70 is inserted into the first hole 100, the first hole 100 expands.

[0025] As shown in FIG. 3, the second porous body 96 is attached to the main body 14 so as to face the second curved surface 86 of the rotating portion 82 of the finger 80. The main body 14 has a mating recess 42 whose bottom surface is the surface where the upper end of the cylinder bore 16 opens. The second porous body 96, which has a step 106, fits into the mating recess 42 of the main body 14. The main body 14 has grooves 44 on the inside of the pair of wide side surfaces 30, and the protrusion 104 of the second porous body 96 fits into this groove 44 (see FIG. 4). The fitting of the protrusion 104 of the second porous body 96 into the groove 44 of the main body 14 prevents the center of the second porous body 96 from being pulled up by the drive rod 70 inserted through the first hole 100.

[0026] The width W2 of the step portion 106 of the second porous body 96 is equal to or slightly larger than the width W0 of the rotating portion 82 of the finger 80. Over the entire rotation range of the finger 80, the second curved surface 86 of the rotating portion 82 of the finger 80 comes into contact with a corner 108 of the step portion 106 of the second porous body 96 (see FIG. 3). The portion of the second porous body 96 that comes into contact with the second curved surface 86 is pressed by the second curved surface 86 and deformed.

[0027] As shown in FIG. 7, the third porous body 110 is formed in the shape of a long, narrow rectangular plate. The third porous body 110 is attached to the main body 14 so as to face the end faces of the pivoting portions 82 of the fingers 80. As shown in FIG. 8, the main body 14 has fitting grooves 46 on the inner sides of a pair of side walls 28, and the third porous body 110 fits into these fitting grooves 46. The third porous bodies 110 are arranged at a total of four locations corresponding to the two end faces of the pivoting portions 82 of each finger 80. Throughout the entire pivoting range of the fingers 80, the end faces of the pivoting portions 82 of the fingers 80 come into planar contact with the third porous body 110 with a predetermined pressure. The third porous body 110 has a hole 112 at the center in the longitudinal direction, through which the pivot support shaft 40 is inserted.

[0028] The main body 14 is provided with a third port 26 to which purge air is supplied, and a communication passage 27 that connects the third port 26 to the second hole 102 of the second porous body 96 (see FIG. 3). The purge air supplied from the third port 26 passes through the communication passage 27 of the main body 14 and the second hole 102 of the second porous body 96, enters the purge air storage space 38, and increases the pressure in the purge air storage space 38.

[0029] The air filled in the purge air storage space 38 passes through the interiors of the first to third porous bodies 94, 96, 110 and is then discharged to the outside. At this time, the air passes over the surface of the first porous body 94 that is exposed to the outside between the end plate 48 and the first curved surface 84 of the rotating portion 82 (see FIGS. 1 and 9). The air also passes over the surface of the second porous body 96 that is exposed to the outside between the main body 14 and the second curved surface 86 of the rotating portion 82 (see FIGS. 1 and 9). The air also passes over the surface of the third porous body 110 that is exposed to the outside between the main body 14 and the end face of the rotating portion 82 (see FIG. 1).

[0030] Next, the opening and closing operation of the fulcrum opening and closing type air chuck 10 will be described with reference to Figures 10 and 11. The fulcrum opening and closing type air chuck 10 is attached to, for example, a conveying device that conveys a workpiece. As shown in Figure 10, the initial state is a state in which the pair of fingers 80 are opened in a straight line.

[0031] The transfer device (not shown) is driven to transfer the fulcrum-opening type air chuck 10 to a position where it can grip a workpiece (not shown). Thereafter, the switching valve (not shown) is switched to a predetermined operating position, the first port 22 is connected to an air supply source (not shown), and the second port 24 is connected to an exhaust port (not shown). As a result, air is supplied to the first pressure chamber 18 and air is exhausted from the second pressure chamber 20, and the piston 60 and the drive rod 70 move downward.

[0032] When the drive rod 70 moves downward, the pair of fingers 80 rotates in a direction in which the pair of gripping portions 92 closes. The pair of fingers 80 rotates to a position where the pair of gripping portions 92 abuts against the end plate 48, entering a closed state (see FIG. 11), and the workpiece is clamped between the pair of fingers 80. Note that, depending on the shape and size of the workpiece, an attachment member (not shown) can be attached to an attachment hole 93 provided in the gripping portions 92.

[0033] The transfer device is driven again, and the fulcrum-opening type air chuck 10 is transferred to a location where the workpiece is to be released. Thereafter, the switching valve is switched to another operating position, the first port 22 is connected to the exhaust port, and the second port 24 is connected to the air supply source. As a result, air is supplied to the second pressure chamber 20 and the air in the first pressure chamber 18 is exhausted, and the piston 60 and the drive rod 70 move upward. When the drive rod 70 moves upward, the pair of fingers 80 rotate in the direction in which the pair of gripping portions 92 open, and the workpiece is released. The piston 60 moves upward until the damper 68 abuts against the bushing 72, and the pair of fingers 80 again open in a straight line (see FIG. 10).

[0034] Next, the dustproof function of the fulcrum opening / closing type air chuck 10 will be described. The purge air storage space 38 is isolated from the outside by the rotating portion 82 of the finger 80 and the first to third porous bodies 94, 96, and 110. Naturally, external dust particles larger than the gaps present inside the first to third porous bodies 94, 96, and 110 cannot penetrate into the first to third porous bodies 94, 96, and 110. External dust particles smaller than the gaps present inside the first to third porous bodies 94, 96, and 110 cannot penetrate into the first to third porous bodies 94, 96, and 110 due to the supply of purge air. The dustproof effect achieved by the supply of purge air will be described below.

[0035] The third port 26 is always connected to an air supply source. That is, purge air is always supplied to the third port 26. The purge air supplied from the third port 26 enters the purge air storage space 38 and increases the pressure in the purge air storage space 38. The air filled in the purge air storage space 38 passes through the insides of the first to third porous bodies 94, 96, and 110 and is then discharged to the outside. At this time, the air passes over the surfaces of the first to third porous bodies 94, 96, and 110 that are exposed to the outside between the body 12 and the rotating part 82.

[0036] The pressure in the purge air storage space 38 is sufficiently higher than the pressure (atmospheric pressure) at the surfaces exposed to the outside of the first to third porous bodies 94, 96, 110. Therefore, even external dust particles smaller than the gaps present inside the first to third porous bodies 94, 96, 110 cannot enter the inside of the first to third porous bodies 94, 96, 110. Even if fine dust particles do enter the inside of the first to third porous bodies 94, 96, 110, they are discharged to the outside together with the purge air.

[0037] The fulcrum opening / closing type air chuck 10 according to this embodiment includes a first porous body 94 attached to the end plate 48 and in contact with the fingers 80. The fulcrum opening / closing type air chuck 10 also includes a second porous body 96 and a third porous body 110 attached to the main body 14 and in contact with the fingers 80. Purge air passes through the first to third porous bodies 94, 96, and 110 and is discharged to the outside. Therefore, dust can be prevented from entering the body 12 without increasing the sliding resistance of the fingers 80. Preventing dust from entering improves the durability of the rod packing 74, piston packing 62, and the like arranged in the cylinder bore 16.

[0038] In this embodiment, purge air is constantly supplied, but if the fulcrum opening / closing type air chuck 10 is used in an environment with little external dust, purge air may be supplied intermittently.

[0039] The fulcrum opening / closing type air chuck according to the present invention is not limited to the above-described embodiment, and various configurations can be adopted without departing from the gist of the present invention. [Explanation of symbols]

[0040] 10...Support point opening and closing type air chuck 14...Body main body (body) 40... Rotation support shaft 48... End plate (body) 60... Piston (drive part) 70... Drive rod (drive part) 80...finger 82...rotating portion 84...First curved surface 86...Second curved surface 92 ...Gripping portion 94 ...First porous body (porous body) 96...2nd porous body (porous body) 100...1st pore part (pore part) 102...2nd hole part (hole part) 106...segment part 108…corner 110…third porous body (porous body) 112…hole

Claims

1. A fulcrum opening / closing type air chuck, in which a pair of fingers are rotatably supported around a rotary support shaft attached to a body, and a drive unit for driving the pair of fingers to open and close is disposed inside the body, a porous body attached to the body and in contact with the finger, and purging air passes through the porous body and is discharged to the outside; The finger is composed of a rotating portion and a gripping portion, the rotating portion having a first curved surface and a second curved surface, the body including a main body and an end plate, a first porous body in contact with the first curved surface attached to the end plate, a second porous body in contact with the second curved surface attached to the main body, the rotating portion having an end surface perpendicular to the axis of the rotation support shaft, and a third porous body in contact with the end surface of the rotating portion attached to the main body, The second porous body has a hole portion which serves as a passage for purge air, and the main body has a port through which purge air is supplied and a communication passage which connects the port to the hole portion, and a fulcrum opening / closing type air chuck in which a purge air storage space isolated from the outside is formed by the rotating part, the first porous body, the second porous body, and the third porous body.

2. 2. The fulcrum opening / closing type air chuck according to claim 1, The rectangular second porous body has stepped portions at both ends for attachment to the main body by fitting, and the second curved surface is a fulcrum-opening / closing type air chuck that contacts the corners of the stepped portions of the second porous body.

3. 2. The fulcrum opening / closing type air chuck according to claim 1, The driving unit includes a driving rod connected to a piston, and the second porous body includes a hole through which the driving rod is inserted.

4. 2. The fulcrum opening / closing type air chuck according to claim 1, The third porous body is a fulcrum opening / closing type air chuck having a hole through which the rotary support shaft is inserted.

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