JP6596409B2 - Clamping device - Google Patents

Description

  The present invention relates to a pin clamp device including a guide pin that penetrates a plate-like component.

2. Description of the Related Art Conventionally, for example, plate-like parts used in, for example, automobile bodies are often welded to other plate-like parts by spot welding when the car body is assembled. Two plate-like parts to be welded by spot welding are held in a state where they overlap each other by a clamp device.
As a conventional clamping device of this type, for example, there is one described in Patent Document 1.

The clamp device disclosed in Patent Document 1 includes a hollow guide pin that fits into a hole for positioning a workpiece made of a plate-shaped part, a clamp arm that fixes the workpiece, and an outer cylinder that drives these members. A device and an inner cylinder device.
The outer cylinder device includes an outer cylinder, an outer piston movably fitted in the outer cylinder, and a cylindrical outer piston rod having one end connected to the outer piston and the other end protruding from the outer cylinder. Yes. The outer piston partitions the inside of the outer cylinder into a first air chamber on the outer piston rod side and a second air chamber on the opposite side.
The guide pin is provided at the front end portion of the outer piston rod, and moves to the front approaching the workpiece or rearward from the workpiece as the outer piston moves relative to the outer cylinder.

The inner cylinder device is movably inserted into the inner cylinder provided inside the outer piston, the inner piston movably fitted in the inner cylinder, and the hollow portion of the outer piston rod. One end is connected to the inner piston, and the other end is provided with an inner piston rod protruding from the inner cylinder. The inner piston partitions the inside of the inner cylinder into a third air chamber on the inner piston rod side and a fourth air chamber on the opposite side.
The third air chamber communicates with the first air chamber by a communication passage that passes through the inner cylinder (outer piston) in the axial direction. The fourth air chamber is provided with a compression coil spring that urges the inner piston forward (to the inner piston rod).

  The clamp arm is provided with a clamping claw at one end, and is accommodated inside the guide pin in a state where the other end is swingably attached to the tip of the inner piston rod. The clamp arm is coupled to the outer piston rod via a cam mechanism. This cam mechanism converts the reciprocating motion in the axial direction of the inner piston rod relative to the outer piston rod into a swinging motion and transmits it to the clamp arm. When the inner piston rod moves forward with respect to the outer piston rod, the clamp arm swings in a direction in which the claw is accommodated in the guide pin, and the inner piston rod moves rearward with respect to the outer piston rod. As a result, the claw swings in a direction protruding sideways of the guide pin.

  In the conventional clamping device configured as described above, the outer piston rod moves forward by supplying air to the second air chamber in a state where the first air chamber is open to the atmosphere. Along with this, the guide pin advances and fits into the hole for positioning the workpiece. In order to clamp the work with the clamp arm after the guide pin is fitted into the work positioning hole, air is supplied to the first air chamber in a state where air is supplied to the second air chamber. . The air supplied to the first air chamber is introduced into the third air chamber through the communication path, and pushes the inner piston against the spring force of the compression coil spring. As the inner piston moves backward, the inner piston rod moves backward with respect to the outer piston rod, and the clamp arm moves backward while swinging from the initial position. By this swing, the claw of the clamp arm protrudes to the side of the guide pin, and the work is sandwiched and fixed between the claw and the base portion of the guide pin.

The work is released by releasing the second air chamber into the atmosphere. That is, the inner piston is pushed forward by the spring force of the compression coil spring, and the clamp arm returns to the initial position.
In order to extract the guide pin from the hole of the workpiece after the workpiece is fixed, air is supplied to the first chamber while the second chamber is open to the atmosphere. By supplying air to the first air chamber, the outer piston and the outer piston rod are retracted, and the guide pin is retracted and pulled out from the hole of the workpiece.

Japanese Patent No. 36553695

  In the clamp device described in Patent Document 1, there is a possibility that the claws of the clamp arm may hit the workpiece when the guide pin moves backward and is pulled out from the hole of the workpiece. The reason that the nail hits the workpiece is considered to be caused by increasing the air pressure in order to accelerate the retraction of the guide pin.

  The guide pin is retracted by supplying air to the first air chamber and retracting the outer piston. At this time, the air supplied to the first air chamber also flows into the third air chamber via the communication path. If the backward thrust acting on the inner piston by supplying air to the third air chamber is larger than the spring force of the compression coil spring, the inner piston moves backward with respect to the outer cylinder, and the inner piston rod Retreat with respect to the outer piston rod. As a result, the clamp arm swings and the claw projects, and the claw comes into contact with the workpiece as described above.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a clamp device in which a guide pin quickly retracts without a nail hitting a workpiece.

  In order to achieve this object, a clamping device according to the present invention includes a hollow guide pin that fits into a hole for positioning a workpiece, a cylindrical outer piston rod provided with the guide pin at a tip portion, An outer piston provided at a base end portion of the outer piston rod; and a first cylinder hole into which the outer piston is movably fitted, and the inner portion is located on the outer piston rod side by the outer piston. An outer cylinder partitioned into a second air chamber opposite to the air chamber, and provided inside the outer piston, with one end communicating with the hollow portion of the outer piston rod and the other end blocked. An inner cylinder having a second cylinder hole and a movably fitted to the inner cylinder, and the inside of the inner cylinder is a fourth on the side opposite to the third air chamber on the outer piston rod side. An inner piston that partitions the air chamber, an inner piston rod that is connected to one end of the inner piston, protrudes from the outer piston and is movably inserted into a hollow portion of the outer piston rod, and is provided at one end. With the pawl inserted into the hollow portion of the guide pin, the other end is swingably connected to the tip of the inner piston rod, and the pawl is guided through the side hole of the guide pin as the swing occurs. The clamp arm that moves in and out of the hollow portion of the pin and the reciprocating motion of the inner piston rod relative to the outer piston rod in the axial direction are converted into a swinging motion to swing the clamp arm with respect to the inner piston rod. A cam mechanism, one end communicating with the first air chamber, the other end opening on the outer surface of the outer cylinder, and one end on the front A second air passage communicating with the second air chamber and having the other end opened to the outer surface of the outer cylinder; a communication passage communicating the first air chamber and the third air chamber; and one end Is communicated with the fourth air chamber and has a third air passage with the other end opened to the outer surface of the outer cylinder, and the third air passage opens into the first cylinder hole, A first hole that communicates the inside and outside of the outer cylinder, and an axial direction of the outer piston that is provided at a position facing the first hole on the outer peripheral surface of the outer piston and that corresponds to the reciprocating stroke of the outer piston. Formed in the inner cylinder, and a second hole that communicates the air chamber and the fourth air chamber.

  According to the present invention, in the clamp device, a portion of the outer piston through which the inner piston rod passes has a cylindrical body into which the inner piston rod is fitted, and the communication path extends along an outer peripheral portion of the cylindrical body. It may be formed.

  According to the present invention, in the clamping device, an elongated hole formed to extend in the axial direction in a portion of the outer piston rod protruding from the outer cylinder, and one end portion of the outer piston rod extends to the inner piston rod through the elongated hole. An interlocking member that is fixed and has the other end extending in parallel with the outer piston rod, and a sensor that is supported by the outer cylinder and that detects a detected portion provided on the interlocking member may be provided.

  According to the present invention, in the clamp device, a guide groove formed in an outer peripheral portion of the outer piston so as to extend in parallel with an axis of the outer piston, and provided in the outer cylinder so as to be movable in the guide groove. You may provide the rotation control mechanism which has a protrusion to fit.

  In the clamping device according to the present invention, a portion of the outer cylinder through which the outer piston rod passes may constitute a bearing in which the outer piston rod is slidably fitted.

  In the clamping device according to the present invention, a sealing member made of a cylinder that is slidable with respect to these members may be provided between the outer piston rod and the inner piston rod.

  In the present invention, by supplying air to the first air chamber and the fourth air chamber, these members are moved in a state where the inner piston and the inner piston rod are advanced with respect to the outer piston and the outer piston rod. Moves backwards with respect to the outer cylinder. For this reason, even if the pressure of the supplied air is high, the guide pin moves backward without the clamp arm swinging. Therefore, according to the present invention, it is possible to provide a clamping device in which the guide pin quickly retracts without the claw hitting the workpiece.

It is a top view of the clamp device concerning the present invention. It is a side view of the clamp device concerning the present invention. It is a front view of the clamp device concerning the present invention. It is a rear view of the clamp apparatus which concerns on this invention. It is sectional drawing which expands and shows the latter half part of a clamp apparatus. It is sectional drawing which expands and shows the front half part of a clamp apparatus. FIG. 6 shows an unclamped state. It is sectional drawing which expands and shows the front-end | tip part of a clamp apparatus. FIG. 7 shows a clamped state. It is the VIII-VIII sectional view taken on the line of the cylinder part in FIG. It is the IX-IX sectional view taken on the line of the cylinder part in FIG. It is the XX sectional view taken on the line in FIG. It is the XI-XI sectional view taken on the line in FIG. It is the XII-XII sectional view taken on the line in FIG. It is the XIII-XIII sectional view taken on the line in FIG. It is the XIV-XIV sectional view taken on the line in FIG. It is sectional drawing of an outer cylinder. It is sectional drawing of an outer side piston, an outer side piston rod, and an inner side cylinder. It is sectional drawing of a rod cover. It is sectional drawing of an inner side piston and an inner side piston rod. It is a perspective view of a connection member. It is sectional drawing for demonstrating operation | movement. 20A shows a downshift unclamped state, FIG. 20B shows a upshift unclamped state, and FIG. 20C shows a upshifted clamp state. It is sectional drawing which shows 2nd Embodiment. 21A shows a shift-down unclamped state, FIG. 21B shows a shift-up unclamped state, and FIG. 21C shows a shift-up unclamped state. It is sectional drawing which shows 3rd Embodiment. 22A shows a shift-down unclamped state, FIG. 22B shows a shift-up unclamped state, and FIG. 22C shows a shift-up clamped state.

(First embodiment)
Hereinafter, an embodiment of a clamping device according to the present invention will be described in detail with reference to FIGS.
A clamping device 1 shown in FIG. 1 is for holding a plurality of plate-like components 2 as works shown on the left side in FIG. The plate-like component 2 has a through hole 2a for positioning. Although two plate-like components 2 are drawn in FIG. 1, the number of plate-like components 2 can be changed as appropriate. In the following, as shown in FIG. 1, one end side (left side in FIG. 1) adjacent to the plate-like component 2 will be described as the front side of the clamp device 1, and the opposite side will be described as the rear side of the clamp device 1. .

The clamp device 1 has a so-called double cylinder structure. As shown in FIGS. 1 to 4, an outer cylinder device 4 including an outer cylinder 3 having a quadrangular prism shape, and an inner portion of the outer cylinder device 4. It is comprised by the inner cylinder apparatus 5 provided in this. The outer cylinder device 4 and the inner cylinder device 5 are arranged on the same axis. The axis lines of the outer cylinder device 4 and the inner cylinder device 5 are indicated by the symbol C in FIG.
As shown in FIG. 8, mounting seats 6 are respectively provided on the three sides of the front portion of the outer cylinder 3. The mounting seat 6 is formed with a plurality of bolt holes 6a. The clamp device 1 is used in a state where a robot arm (not shown) is attached to any one of the attachment seats 6 and supported by the robot arm.

As shown in FIGS. 1 and 2, a guide pin 7 that fits in the through hole 2 a of the plate-like component 2 is provided at the front end of the clamp device 1 so as to protrude forward. The clamp device 1 is arranged by a robot arm at a position where the guide pin 7 is adjacent to the plate-like component 2.
The guide pin 7 is formed in a hollow cylindrical shape that fits into the through hole 2 a of the plate-like component 2, and is driven by the outer cylinder device 4 to move forward or backward.

<Configuration of guide pin>
The front end portion of the guide pin 7 is rounded, and a lateral hole 7a (see FIG. 6) extending in a direction orthogonal to the axial direction (left-right direction in FIG. 1) is formed in the intermediate portion. The rear end portion of the guide pin 7 is formed integrally with the cylindrical body 8. A pressure receiving portion 9 that contacts the plate-like component 2 is provided at a boundary portion between the cylindrical body 8 and the guide pin 7.
Inside the guide pin 7 is housed a clamp arm 11 that holds the plate-like component 2 against the pressure receiving portion 9 described above during clamping. A claw 12 is provided at the front end of the clamp arm 11. Although details will be described later, the clamp arm 11 swings so that the claw 12 protrudes from the lateral hole 7a of the guide pin 7 to the outside of the guide pin 7 at the time of clamping, and translates backward in this state. The drive of the clamp arm 11 is performed by an inner cylinder device 5 described later.

<Configuration of outer cylinder device>
As shown in FIGS. 5 and 6, the outer cylinder device 4 is connected to the outer cylinder 3 constituting the housing of the clamping device 1, the outer piston 13 provided in the outer cylinder 3, and the outer piston 13. The outer piston rod 14 is provided.
As shown in FIG. 1 and FIG. 2, an unclamped state detection sensor 15, a clamped state detection sensor 16, and an outer portion of the outer cylinder 3, which is not provided with the mounting seat 6, A moving member 19 having a front side detection unit 17 and a rear side detection unit 18 detected by these sensors is provided.

  The moving member 19 is accommodated in a concave groove 20 extending in the axial direction of the outer cylinder 3, and is supported by the concave groove 20 so as to be movable in the axial direction of the outer cylinder 3. Although the details will be described later, the moving member 19 moves in the axial direction of the outer cylinder 3 in conjunction with the clamp arm 11. The “axial direction” described below is all the axial direction of the outer cylinder 3.

The unclamped state detection sensor 15 and the clamped state detection sensor 16 are constituted by proximity switches, and detect them when the front side detection unit 17 or the rear side detection unit 18 enters inside a predetermined detection range. In this embodiment, the front side detection unit 17 and the rear side detection unit 18 correspond to the “detected unit” according to the invention of claim 3.
First to third ports 21 to 23 for supplying high-pressure air to the outer cylinder device 4 and the inner cylinder device 5 are formed on one side portion of the outer cylinder 3 described above.

  A shift-up detection sensor 24 and a shift-down detection sensor 25 are provided at the rear portion of the outer cylinder 3 and on the other side portion adjacent to the one side portion described above. These upshift detection sensor 24 and downshift detection sensor 25 are magnetic sensors and detect a magnet 26 (see FIG. 5) provided on the outer piston 13 described later.

<Configuration of outer cylinder>
As shown in FIG. 15, a first cylinder hole 27 is formed in the outer cylinder 3. A front end portion (left end portion in FIG. 15) of the first cylinder hole 27 is connected to a shaft hole 28 formed at the front end portion of the outer cylinder 3. The shaft hole 28 is formed to allow passage of an outer piston rod 14 described later, and is formed to have a smaller diameter than the first cylinder hole 27 and is positioned on the same axis as the first cylinder hole 27. The shaft hole 28 is formed in a shape in which the outer piston rod 14 is slidably fitted. The front end portion of the outer cylinder 3 having the shaft hole 28 functions as a bearing 29 that supports the outer piston rod 14. The shaft hole 28 is provided with seal members 30 and 31 for sealing between the outer piston rod 14 and the shaft hole 28.

An end face 32 as a stopper for restricting the advance of the outer piston 13 described later is formed at a boundary portion between the shaft hole 28 and the first cylinder hole 27.
One end of the first air passage 33 is opened at the front end of the first cylinder hole 27. The other end of the first air passage 33 opens on the outer surface of the outer cylinder 3. The portion of the first air passage 33 that opens to the outer surface of the outer cylinder 3 constitutes the first port 21 described above.

  The rear end portion of the first cylinder hole 27 is closed by a first lid 34 fixed to the outer cylinder 3. As shown in FIGS. 4 and 15, the first lid body 34 is formed in a disk shape and is prevented from being detached by a circlip 35 while being fitted in the first cylinder hole 27. A seal member 36 is provided on the outer peripheral portion of the first lid 34 in order to seal the space between the first lid 34 and the first cylinder hole 27. Further, the first lid 34 is provided with a rubber member 37 that regulates the retreat of the outer piston 13 described later.

One end of the second air passage 38 is opened at the rear end portion of the first cylinder hole 27. The other end of the second air passage 38 opens to the outer surface of the outer cylinder 3. A portion of the second air passage 38 that opens to the outer surface of the outer cylinder 3 constitutes the second port 22 described above.
A first hole 40 that constitutes a part of the third air passage 39 is opened at an intermediate portion in the front-rear direction of the first cylinder hole 27. The first hole 40 communicates the inside and outside of the outer cylinder 3. The portion of the first hole 40 that opens to the outer surface of the outer cylinder 3 constitutes the third port 23 described above. The configuration of the third air passage 39 will be described later.
A screw hole 41 is formed in a portion of the first cylinder hole 27 facing the first hole 40 (a portion on the opposite side in the radial direction). A locking plug 42 (see FIGS. 5 and 10), which will be described later, is screwed into the screw hole 41.

<Configuration of outer piston rod>
As shown in FIG. 16, the outer piston rod 14 is formed in a cylindrical shape having a hollow portion 43. A cylindrical portion 44 of the outer piston 13 is formed integrally with the rear end portion of the outer piston rod 14 according to this embodiment.
The outer piston rod 14 is formed in a shape in which the outer diameter increases stepwise from the front end toward the rear end outer piston 13, and the front end portion 14a, the intermediate portion 14b, and the shaft portion 14c having different outer diameters are formed. And have. The front end portion 14 a having the smallest outer diameter of the outer piston rod 14 has a function of supporting the guide pin 7. As shown in FIG. 6, the front end portion 14 a is fitted to the inner peripheral portion of the cylindrical body 8 that is integral with the guide pin 7. The cylindrical body 8 is fixed to the front end portion 14a of the outer piston rod 14 by a plurality of fixing bolts 8a (see FIG. 3).

  Moreover, as shown in FIG. 16, the front end part 14a of the outer piston rod 14 is formed with a first pin hole 45 and a first long hole 46 that is long in the axial direction. Further, a second long hole 47 that is long in the axial direction is formed in the intermediate portion 14b adjacent to the front end portion 14a. As shown in FIGS. 11 to 14, the first pin hole 45 and the first and second elongated holes 46 and 47 penetrate the outer piston rod 14 in a direction orthogonal to the axial direction. .

A shaft portion 14 c adjacent to the intermediate portion 14 b of the outer piston rod 14 on the rear side is formed in a shape that fits slidably into the shaft hole 28 of the outer cylinder 3. The outer piston rod 14 is positioned on the same axis as the first cylinder hole 27 of the outer cylinder 3 by fitting the shaft portion 14 c into the shaft hole 28.
As shown in FIG. 16, a communication hole 48 that communicates the inside and outside of the outer piston rod 14 is formed in the boundary portion between the shaft portion 14 c and the cylindrical portion 44 of the outer piston 13. The communication hole 48 is inclined so as to be gradually located on the rear side from the outer peripheral surface side of the shaft portion 14 c toward the inside of the outer piston 13.

<Configuration of outer piston>
As shown in FIG. 16, the outer piston 13 includes a cylindrical portion 44 connected to the shaft portion 14 c of the outer piston rod 14 and a second lid 51 that closes the rear end of the cylindrical portion 44. Yes.
The cylindrical portion 44 is formed in a shape that is movably fitted into the first cylinder hole 27. A sealing member 52 for sealing between the first cylinder hole 27 and the first cylinder hole 27 is provided at the front end portion of the outer peripheral portion of the cylindrical portion 44.
A first concave groove 53 and a second concave groove 54 are formed on the outer peripheral portion of the cylindrical portion 44 and on the rear side of the seal member 52.

  These first and second concave grooves 53 and 54 extend from the front end portion of the outer piston 13 to the rear end portion in the axial direction of the outer piston 13. The lengths of the first and second concave grooves 53 and 54 correspond to the reciprocating stroke of the outer piston 13. The outer piston 13 can be advanced until its front end abuts on the above-described end surface 32 (see FIG. 15) of the outer cylinder 3. Further, the outer piston 13 can be retracted until its rear end comes into contact with the rubber member 37 of the outer cylinder 3. The reciprocating stroke of the outer piston 13 is the moving distance of the outer piston 13 from the position where the front end abuts on the end surface 32 until the rear end abuts on the rubber member 37.

  As shown in FIG. 5, the first concave groove 53 is provided at a position facing the first hole 40 of the outer cylinder 3. In this embodiment, the first concave groove 53 corresponds to an “air chamber” in the present invention. The rear portion of the first concave groove 53 is communicated with the internal space of the cylindrical portion 44 through the second hole 55. The second hole 55 is disposed in front of the second lid 51 and communicates the inside and outside of the outer piston 13.

  As shown in FIG. 9, the second groove 54 is formed on the opposite side to the first groove 53 in the radial direction of the outer piston 13. As shown in FIGS. 5 and 10, the tip end portion of the above-described locking plug 42 is engaged with the second concave groove 54. The rotation-preventing plug 42 is engaged with the second concave groove 54, whereby the movement of the outer piston 13 in the circumferential direction is restricted. That is, the clamp device 1 includes a rotation restricting mechanism 56 including the second concave groove 54 and the rotation stopper plug 42. In this embodiment, the second concave groove 54 corresponds to a “guide groove” according to the invention of claim 4, and the anti-rotation plug 42 corresponds to a “projector”.

  As shown in FIG. 16, the second lid 51 includes a small-diameter portion 51 a that fits into the cylindrical portion 44 of the outer piston 13 from the rear, and a large-diameter portion that fits movably in the first cylinder hole 27. And 51b. An annular groove 57 is formed on the outer peripheral portion of the small diameter portion 51a, and a seal member 58 for sealing between the cylindrical portion 44 is provided. As shown in FIG. 9, a plurality of screw holes 59 are formed in a portion of the cylindrical portion 44 that faces the annular groove 57 of the second lid 51. A hexagonal set screw 60 is screwed into each of the screw holes 59. The second lid body 51 is fixed to the cylindrical portion 44 by engaging these set screws 60 with the annular groove 57.

As shown in FIG. 16, a seal member 61 for sealing between the first cylinder hole 27 and the first cylinder hole 27 is provided in the large diameter portion 51 b of the second lid 51.
A disc 62 having a ring-shaped magnet 26 is fixed to the rear end portion of the second lid 51 by fixing bolts 63. The magnet 26 is detected by the shift-up detection sensor 24 and the shift-down detection sensor 25 described above.

  When the outer piston 13 configured in this manner is fitted into the first cylinder hole 27, the inside of the outer cylinder 3 is opposite to the first air chamber 64 on the outer piston rod 14 side, as shown in FIG. The second air chamber 65 is partitioned. As shown in FIG. 6, the first air chamber 64 is communicated with the outside of the outer cylinder 3 by the first air passage 33. As shown in FIG. 5, the second air chamber 65 is communicated with the outside of the outer cylinder 3 by the second air passage 38.

<Configuration of inner cylinder device>
The rear half of the outer piston 13 according to this embodiment constitutes an inner cylinder 71 of the inner cylinder device 5. As shown in FIG. 5, the inner cylinder device 5 includes an inner cylinder 71 provided inside the outer piston 13, an inner piston 72 disposed in the inner cylinder 71, and extends forward from the inner piston 72. And an inner piston rod 73.
<Configuration of inner cylinder>
The inner cylinder 71 has a second cylinder hole 74 whose rear end is closed by the second lid 51. As shown in FIG. 16, the front end portion of the second cylinder hole 74 is in communication with the hollow portion 43 of the outer piston rod 14. The hollow portion 43 of the outer piston rod 14 is formed to have a smaller diameter than the second cylinder hole 74. A cylindrical rod cover 75 is provided at the boundary portion between the hollow portion 43 and the second cylinder hole 74 as shown in FIG. A small-diameter hole 76 located on the front side and a large-diameter hole 77 located on the rear side are formed in the boundary portion. The rear end of the communication hole 48 described above opens to the large-diameter hole 77.

  As shown in FIG. 5, the front end portion of the rod cover 75 is fitted into the small diameter hole 76 and supported by the outer piston rod 14. A flange 78 that fits into the second cylinder hole 74 is provided at the rear end of the rod cover 75, and is supported by the inner cylinder 71 via the flange 78. The rearward movement of the flange 78 is restricted by a circlip 79.

The flange 78 has a plurality of through holes 78a. These through holes 78 a communicate the annular space 80 formed between the rod cover 75 and the large diameter hole 77 and the inside of the front end portion of the second cylinder hole 74.
A seal member 81 for sealing between the small diameter hole 76 and a seal member 82 for sealing between the inner piston rod 73 described later are provided at the front end of the rod cover 75. A seal member 83 is provided at the rear end of the rod cover 75 to seal between the rod cover 75 and an inner piston rod 73 described later.

<Configuration of inner piston>
The inner piston 72 is formed in a disc shape and is movably fitted in the second cylinder hole 74, and the inside of the inner cylinder 71 is opposite to the third air chamber 84 on the outer piston rod 14 side. The fourth air chamber 85 is partitioned. The third air chamber 84 is communicated with the first air chamber 64 via a communication passage 86 including the through hole 78 a of the flange 78, the annular space 80, and the communication hole 48 of the outer piston rod 14. .
The communication path 86 is formed along the outer periphery of the rod cover 75. In this embodiment, the rod cover 75 corresponds to a “cylindrical body” in the invention described in claim 2.
The fourth air chamber 85 is communicated to the outside of the outer cylinder 3 through the third air passage 39 including the second hole 55, the first groove 53, and the first hole 40 described above. ing.

  As shown in FIG. 18, a seal member 87 that seals between the inner cylinder 72 and the second cylinder hole 74 is provided on the outer peripheral portion of the inner piston 72. An inner piston rod 73 is attached to a front end portion of the inner piston 72 and an axial center portion by a fixing bolt 88.

<Configuration of inner piston rod>
The inner piston rod 73 is formed in a cylindrical shape and extends forward through the outer piston rod 14 through the rod cover 75. A portion where the inner piston rod 73 penetrates the inner cylinder 71 is sealed by three seal members 81 to 83 provided on the rod cover 75.

  As shown in FIGS. 12 and 14, the front end portion of the inner piston rod 73 is formed in a bifurcated shape having a pair of support pieces 91 and 91. A second pin hole 92 extending in a direction perpendicular to the axial direction is formed in the support pieces 91 and 91. A rear end portion 11 a of the clamp arm 11 is inserted between the support pieces 91. The rear end portion of the clamp arm 11 is also provided with a third pin hole 93 extending in a direction orthogonal to the axial direction. The first pin 94 is passed through the second pin hole 92 of the pair of support pieces 91 and the third pin hole 93 of the clamp arm 11.

  The rear end portion 11 a of the clamp arm 11 is swingably supported by the pair of support pieces 91 via the first pins 94. Both end portions of the first pin 94 protrude from the support piece 91 and are fitted in the first elongated hole 46 of the outer piston rod 14. For this reason, the front end of the inner piston rod 73 is supported by the outer piston rod 14 via the first pin 94 so as to be movable in the front-rear direction.

<Composition of cam mechanism>
As shown in FIGS. 6 and 7, the clamp arm 11 projects forward from the front end of the inner piston rod 73 to the inside of the front end of the guide pin 7. A long hole 95 serving as a cam is formed in an intermediate portion of the clamp arm 11 in the front-rear direction. A second pin 96 extending in a direction orthogonal to the axial direction passes through the elongated hole 95. As shown in FIGS. 11 and 14, both end portions of the second pin 96 are fitted in the first pin holes 45 of the outer piston rod 14 and are fixed to the outer piston rod 14.

  The long hole 95 serving as a cam converts the reciprocating motion of the clamp arm 11 relative to the second pin 96 in the front-rear direction (the axial direction of the inner piston rod 73) into a swinging motion. In the elongated hole 95 according to this embodiment, the claw 12 of the clamp arm 11 is accommodated in the guide pin 7 when the clamp arm 11 moves forward with respect to the second pin 96, and the clamp arm 11 is in the second position. The claw 12 is configured to protrude from the lateral hole 7 a of the guide pin 7 by moving backward relative to the pin 96. In this embodiment, the long hole 95 and the second pin 96 serving as a cam correspond to the “cam mechanism” in the present invention.

A portion of the inner piston rod 73 corresponding to the second elongated hole 47 of the outer piston rod 14 has a fourth pin hole 97 extending in a direction orthogonal to the axial direction, as shown in FIGS. In addition, a sealing member 98 made of a cylinder and a third pin 99 fitted into the fourth pin hole 97 are provided.
The seal member 98 has a shape that fits between the outer piston rod 14 and the inner piston rod 73, and is formed of a metal material in a shape that is slidable with respect to these members. The seal member 98 is provided with a fifth pin hole 98a for allowing the third pin 99 to pass therethrough.

The third pin 99 is passed through the second elongated hole 47 so as to be fitted into the fifth pin hole 98a of the seal member 98 and the fourth pin hole 97 of the inner piston rod 73, respectively. The inner piston rod 73 is fixed. Both end portions of the third pin 99 protrude outside the outer piston rod 14 and are connected to the above-described moving member 19 via the connecting member 101.
As shown in FIG. 19, the connecting member 101 is formed in a gate shape by a pair of arm portions 101a and a connecting portion 101b that connects the ends of the arm portions 101a. The pair of arm portions 101 a of the connecting member 101 are connected to the third pin 99, and the connecting portion 101 b is connected to the moving member 19. For this reason, when the inner piston rod 73 moves forward or backward relative to the outer piston rod 14, the moving member 19 moves forward or backward in conjunction with the inner piston rod 73. In this embodiment, one assembly including the third pin 99, the connecting member 101, and the moving member 19 corresponds to the “interlocking member” in the invention of claim 3.

<Configuration of air supply device>
The operation of the clamping device 1 according to this embodiment is controlled using an air supply device 114 having first to third solenoid valves 111 to 113, as shown in FIG.
The 1st-3rd solenoid valves 111-113 are 2 position double solenoid 5 port valves, respectively, and are used as a 3 port valve using a plug. The first solenoid valve 111 is connected to the first port 21 of the outer cylinder 3.

The second solenoid valve 112 is connected to the second port 22 via the meter-in speed controller 115.
The third solenoid valve 113 is connected to the third port 23 of the outer cylinder 3. These first to third solenoid valves 111 to 113 are respectively supplied with high-pressure air of the same pressure from a common pressure source (not shown).

  In order to clamp the plate-like component 2 using the clamp device 1, first, the clamp device 1 is set in an initial state as shown in FIG. This initial state is realized by setting the first solenoid valve 111 and the third solenoid valve 113 to the air supply state and opening the second solenoid valve 112. That is, when the first solenoid valve 111 is in the air supply state and the second solenoid valve 112 is in the open state, air is supplied from the first port 21 to the first air chamber 64 and the second air valve Air in the chamber 65 is exhausted from the second port 22. For this reason, the outer side piston 13 retracts to the rear end position. At this time, since the magnet 26 of the outer piston 13 is detected by the shift-down detection sensor 25, the shift-down detection sensor 25 can detect that the outer piston 13 has moved to the rear end position.

Further, at this time, when the third solenoid valve 113 is in an air supply state, air is supplied from the third port 23 to the first hole 40, the first concave groove 53, and the second hole 55. The third air passage 39 is supplied to the fourth air chamber 85. At this time, the air pressure is also transmitted from the first air chamber 64 to the third air chamber 84 via the communication path 86, but the inner piston is connected between the third air chamber 84 and the fourth air chamber 85. There is a difference in the pressure receiving area of 72, and thrust acts on the inner piston 72 in the forward direction, so that the inner piston 72 moves to the front end position of the inner cylinder 71.

As the inner piston 72 moves forward relative to the inner cylinder 71, the claw 12 of the clamp arm 11 is accommodated in the guide pin 7. At this time, since the front side detection part 17 of the moving member 19 that moves integrally with the inner piston 72 is detected by the unclamped state detection sensor 15, the inner piston 72 has moved to the front end position (the claw 12 has been accommodated). Can be detected using the unclamped state detection sensor 15.
The initial state described above is the shift-down state in which the outer piston 13 has moved to the rear end position as described above and the unclamped state in which the claws 12 of the clamp arm 11 are accommodated.
In order to clamp the plate-like component 2 using the clamping device 1, first, the robot arm is operated in this initial state, and the guide pin 7 is opposed to the plate-like component 2.

  Next, as shown in FIG. 20 (B), the first solenoid valve 111 is set in a released state, and the second and third solenoid valves 112 and 113 are set in an air supply state. As the first to third solenoid valves 111 to 113 operate in this manner, the outer piston 13 moves forward to the front end position (shift-up position) while the inner piston 72 is held at the front end position. At this time, since the air is supplied to the second air chamber 65 through the meter-in speed controller 115, the outer piston 13 rapidly advances and the advance of the inner piston 72 and the inner cylinder rod 73 is delayed. Absent.

  For this reason, the guide pin 7 advances without the claw 12 of the clamp arm 11 projecting, and is correctly fitted into the through hole 2 a of the plate-like component 2. At this time, the magnet 26 of the outer piston 13 is detected by the shift-up detection sensor 24, and the shift-up detection sensor 24 can detect that the outer piston 13 is located at the front end position. Further, in order for the unclamped state detection sensor 15 to detect the rear side detection unit 18 of the moving member 19, the unclamped state detection sensor 15 detects that the inner piston 72 is located at the front end position. be able to.

Thus, clamping is performed in the up-shifted state in which the outer piston 13 has moved to the front end position and in the unclamped state in which the claws 12 of the clamp arm 11 are accommodated.
As shown in FIG. 20C, the clamping is performed by setting the first solenoid valve 111 and the second solenoid valve 112 to the air supply state and the third solenoid valve 113 to the open state. When the first solenoid valve 111 is in the air supply state, air is supplied to the first air chamber 64 and the third air chamber 84, and when the second solenoid valve 112 is in the air supply state, the second air is supplied. Air is supplied to the chamber 65.

  At this time, the outer piston 13 is held at the front end position. This is because the pressure receiving area on the first air chamber 64 side is smaller than the pressure receiving area on the second air chamber 65 side, and thrust acts on the outer piston 13 in the forward direction. Therefore, at this time, the inner piston 72 moves backward with respect to the outer piston 13 as the pressure in the third air chamber 84 increases. As the inner piston 72 retreats in this way, the clamp arm 11 swings and the claw 12 protrudes from the guide pin 7, and the claw 12 translates backward to receive the plate-like component 2 by the pressure received by the guide pin 7. Press against part 9 and hold. In this case, since the magnet 26 of the outer piston 13 is detected by the shift-up detection sensor 24, the shift-up detection sensor 24 can detect that the outer piston 13 is located at the front end position. Moreover, since the rear side detection part 18 of the moving member 19 is detected by the clamp state detection sensor 16, the clamp state detection sensor 16 can detect that the inner piston 72 is retracted and the claw 12 protrudes. it can.

  In this way, the plate-like component 2 is welded or otherwise processed in the up-shifted state in which the outer piston 13 has moved to the front end position and in the clamped state in which the claws 12 of the clamp arm 11 have been projected. After this operation is completed, in order to release the clamped state, the first solenoid valve 111 is opened, and the second solenoid valve 112 and the third solenoid valve 113 are brought into an air supply state. By switching the first to third solenoid valves 111 to 113 in this manner, the inner piston 72 moves forward to the front end position while the outer piston 13 is held at the front end position, and the clamp arm 11 swings while moving forward. The claw 12 is moved and accommodated in the guide pin 7.

  Then, as shown in FIG. 20A, the first solenoid valve 111 and the third solenoid valve 113 are in an air supply state, and the second solenoid valve 112 is in an open state. As the first to third solenoid valves 111 to 113 operate in this way, the outer piston 13 moves back to the rear end position while the unclamped state is maintained, and the guide pin 7 is inserted into the through hole of the plate-like component 7. The clamp device 1 is pulled out from 7a to be in the initial state described above.

  In the clamp device 1 configured as described above, air is supplied to the first air chamber 64 and the fourth air chamber 85, whereby the inner piston 72 and the inner piston rod 73 are connected to the outer piston 13 and the outer piston. These members are moved backward with respect to the outer cylinder 3 in a state of being advanced with respect to the rod 14. For this reason, even if the pressure of the supplied air is high, the guide pin 7 moves backward without the clamp arm 11 swinging. Therefore, according to this embodiment, it is possible to provide a clamping device in which the guide pin 7 is quickly retracted without the claw 12 projecting and hitting the plate-like component 2 (workpiece).

The length of the outer piston 13 in the axial direction according to this embodiment is a length corresponding to the reciprocating stroke of the guide pin 7. A portion of the outer piston 13 through which the inner piston rod 73 passes has a rod cover 75 (cylindrical body) into which the inner piston rod 73 is fitted. A communication path 86 that communicates the first air chamber 64 and the third air chamber 84 is formed along the outer peripheral portion of the rod cover 75.
In this embodiment, a portion extending in the axial direction of the outer piston 13 in the communication path 86 is provided between the large diameter hole 77 formed to pass the inner piston rod 73 through the outer piston 13 and the rod cover 75. Can be formed. For this reason, compared with the case where the portion extending in the axial direction in the outer piston 13 in the communication passage 86 is formed by machining, this portion can be easily formed longer, and the outer piston 13 is formed longer in the axial direction. Thus, the reciprocating stroke of the guide pin 7 can be formed long.

The outer piston rod 14 according to this embodiment is formed with a second elongated hole 47 extending in the axial direction. The clamping device 1 according to this embodiment includes an interlocking member (a third pin 99, a connecting member 101, and a moving member 19) having one end fixed to the inner piston rod 73 through the second elongated hole 47. And an unclamped state detecting sensor 15 and a clamped state detecting sensor 16 for detecting the front side detecting portion 17 or the rear side detecting portion 18 (detected portion) of the interlocking member.
For this reason, since the position of the inner piston rod 73 can be accurately detected from the outside, it is possible to provide a clamping device with high operational reliability.

The clamp device 1 according to this embodiment is provided in a second concave groove 54 (guide groove) formed in the outer peripheral portion of the outer piston 13 and a second concave groove 54 provided in the outer cylinder 3 so as to be freely movable. A rotation restricting mechanism 56 including a locking plug 42 (protrusion) for mating is provided.
For this reason, since the outer piston 13 does not rotate around the axis, the direction in which the claw 12 protrudes from the guide pin 7 is constant, and high clamping performance can be maintained.

  In the clamping device 1 of this embodiment, a portion of the outer cylinder 3 through which the outer piston rod 14 penetrates constitutes a bearing 29 into which the outer piston rod 14 is slidably fitted. For this reason, the outer piston rod 14 moves parallel to the axis of the outer cylinder 3, and the accuracy of the position of the guide pin 7 increases.

In this embodiment, a seal member 98 made of a cylinder slidable with respect to these members is provided between the outer piston rod 14 and the inner piston rod 73.
For this reason, fine foreign matters such as spatter generated when welding the plate-like component 2 can be prevented from entering the cylinder through the gap between the outer piston rod 14 and the inner piston rod 73. Therefore, it is possible to provide a clamping device with high operation reliability.

(Second Embodiment)
An air supply device that supplies air to the clamp device can be configured as shown in FIG. In FIG. 21, members that are the same as or equivalent to those described with reference to FIGS.
The air supply device 114 shown in FIG. 21 includes a fourth solenoid valve 121 connected to the first port 21 and the third port 23 of the outer cylinder 3, and a meter-in speed controller 115 in the second port 22. And a fifth solenoid valve 122 connected thereto. The fourth solenoid valve 121 is a three-position double solenoid 5-port valve. The fifth solenoid valve 122 is a 2-position single solenoid 5-port valve, and is used as a 3-port valve using a plug.

In this embodiment, in order to set the clamping device 1 to the initial state, as shown in FIG. 21A, the fourth solenoid valve 121 supplies the first port 21 and the third port 23 with air. The second port 22 is opened by the fifth solenoid valve 122.
In order to set the clamp device 1 in the upshifted state and the unclamped state, as shown in FIG. 21B, the first solenoid valve 121 is used to open the first port 21 as shown in FIG. The third port 23 is set in the air supply state, and the second solenoid port 122 is set in the air supply state by the fifth solenoid valve 122.

Further, in order to set the clamp device 1 in the upshifted state and in the clamped state, as shown in FIG. 21C, the fourth solenoid valve 121 sets the first port 21 to the air supply state and the second state. 3 port 23 is opened, and the second solenoid valve 122 is used to bring the second port 22 into an air supply state.
Even if the air supply device 114 is configured as shown in this embodiment, the same effect as that obtained in the first embodiment can be obtained.

(Third embodiment)
The air supply device that supplies air to the clamp device can be configured as shown in FIG. 22, the same or equivalent members as described with reference to FIGS. 1 to 20 are denoted with the same reference numerals, and detailed description thereof is omitted as appropriate.
An air supply device 114 shown in FIG. 22 includes a shuttle valve 132 having an outlet 131 connected to the first port 21 of the outer cylinder 3, a first inlet 133 of the shuttle valve 132, and a third port of the outer cylinder 3. The second solenoid valve 134 connected to the second inlet 135 of the shuttle valve 132 and the second port 22 of the outer cylinder 3 via the meter-in speed controller 115. 7 solenoid valves 136.
The sixth solenoid valve 134 and the seventh solenoid valve 136 are two-position double solenoid 5-port valves.

In this embodiment, in order to set the clamping device 1 to the initial state, as shown in FIG. 22A, the third port 23 is brought into the air supply state by the sixth solenoid valve 134, and the seventh solenoid is set. The valve 136 causes the second inlet 135 of the shuttle valve 132 to be in an air supply state and causes the second port 22 of the outer cylinder 3 to be in an open state.
Further, in order to set the clamping device 1 in the upshifted state and the unclamped state, as shown in FIG. 22B, the third port 23 is brought into the air supply state by the sixth solenoid valve 134, The seventh inlet valve 135 of the shuttle valve 132 is opened by the seventh solenoid valve 136 and the second port 22 of the outer cylinder 3 is brought into an air supply state.
Furthermore, in order to set the clamp apparatus 1 in the upshift state and the clamp state, as shown in FIG. 22C, the sixth inlet valve 133 of the shuttle valve 132 is supplied with air by the sixth solenoid valve 134. And the third port 23 of the outer cylinder 3 is opened, and the second port 22 of the outer cylinder 3 is brought into the air supply state by the seventh solenoid valve 136.
Even if the air supply device 114 is configured as shown in this embodiment, the same effect as that obtained by adopting the first and second embodiments can be obtained.

  DESCRIPTION OF SYMBOLS 1 ... Clamp apparatus, 2 ... Plate-shaped component (workpiece), 2a ... Through-hole (positioning hole), 3 ... Outer cylinder, 7 ... Guide pin, 7a ... Lateral hole, 11 ... Clamp arm, 12 ... Claw, 13 ... Outer piston, 14 ... outer piston rod, 15 ... unclamped state detection sensor, 16 ... clamped state detection sensor, 17 ... front side detection part (detected part), 18 ... rear side detection part (detected part), 19 ... moving member, 27 ... first cylinder hole, 29 ... bearing, 33 ... first air passage, 38 ... second air passage, 39 ... third air passage, 40 ... first hole, 42 ... around Stop plug (projector), 47 ... second slot, 53 ... first groove (air chamber), 54 ... second groove (guide groove), 55 ... second hole, 56 ... rotation Restricting mechanism, 64 ... first air chamber, 65 ... second air chamber, 71 ... inner cylinder, 72 ... Side piston 73 ... Inner piston rod 74 ... Second cylinder hole 75 ... Rod cover (cylindrical body) 84 ... Third air chamber 85 ... Fourth air chamber 86 ... Communication passage 95 ... Long Hole, 98 ... sealing member, 99 ... third pin, 101 ... connecting member.

Claims (6)

A hollow guide pin that fits into the hole for positioning the workpiece;
A cylindrical outer piston rod provided with a guide pin at a tip thereof;
An outer piston provided at the proximal end of the outer piston rod;
The outer piston has a first cylinder hole in which the outer piston is movably fitted, and the outer piston partitions the interior into a first air chamber on the outer piston rod side and a second air chamber on the opposite side. An outer cylinder;
An inner cylinder provided inside the outer piston, having a second cylinder hole with one end communicating with the hollow portion of the outer piston rod and the other end closed;
An inner piston that is movably fitted to the inner cylinder and partitions the interior of the inner cylinder into a third air chamber on the outer piston rod side and a fourth air chamber on the opposite side;
An inner piston rod connected to one end of the inner piston, protruding from the outer piston and movably inserted into a hollow portion of the outer piston rod;
With the claw provided at one end inserted into the hollow portion of the guide pin, the other end is swingably connected to the tip of the inner piston rod, and the claw is moved along the guide pin with the swing. A clamp arm that goes in and out of the hollow portion of the guide pin through the lateral hole of
A cam mechanism for converting the reciprocating motion of the inner piston rod in the axial direction relative to the outer piston rod into a swinging motion to swing the clamp arm with respect to the inner piston rod;
A first air passage having one end communicating with the first air chamber and the other end opening on the outer surface of the outer cylinder;
A second air passage having one end communicated with the second air chamber and the other end opened to the outer surface of the outer cylinder;
A communication path communicating the first air chamber and the third air chamber;
A third air passage having one end communicating with the fourth air chamber and the other end opening on the outer surface of the outer cylinder;
The third air passage is
A first hole that opens into the first cylinder hole and communicates with the inside and outside of the outer cylinder;
An air chamber provided at a position facing the first hole on the outer peripheral surface of the outer piston and extending in the axial direction of the outer piston by a length corresponding to the reciprocating stroke of the outer piston;
A clamp device provided in the inner cylinder and formed by a second hole communicating the air chamber and the fourth air chamber. The clamping device according to claim 1,
The portion of the outer piston through which the inner piston rod passes has a cylindrical body into which the inner piston rod is fitted,
The clamp device, wherein the communication path is formed along an outer peripheral portion of the cylindrical body. The clamping device according to claim 1 or 2,
Furthermore, an elongated hole formed to extend in the axial direction in a portion protruding from the outer cylinder in the outer piston rod;
One end portion is fixed to the inner piston rod through the elongated hole, and the other end portion extends in parallel with the outer piston rod;
A clamp device comprising: a sensor that is supported by the outer cylinder and that detects a detected portion provided in the interlocking member. The clamping device according to any one of claims 1 to 3,
Further, a guide groove formed on the outer peripheral portion of the outer piston so as to extend parallel to the axis of the outer piston,
A clamp device comprising a rotation restricting mechanism provided on the outer cylinder and having a protrusion movably fitted in the guide groove. The clamping device according to any one of claims 1 to 4,
A portion of the outer cylinder through which the outer piston rod penetrates constitutes a bearing into which the outer piston rod is slidably fitted. The clamping device according to any one of claims 1 to 5,
A clamping device, wherein a sealing member made of a cylinder slidable with respect to these members is provided between the outer piston rod and the inner piston rod.

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