JP2013188846A - Clamp device and workpiece machining jig - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clamp device capable of accurately detecting an over-stroke, and to provide a workpiece machining jig.SOLUTION: A clamp device 1 for fixing a workpiece W having a cast hole 2 includes a rod 20 having a shaft 21 and a tapered portion 22, grip claws 31 deformable in the radial direction of the tapered portion 22, a rod drive part 50 including a cylinder 51 and a piston 52, and an over-stroke detecting mechanism 60. The over-stroke detecting mechanism 60 includes a detecting valve 62 protruded to the side of the piston 52 and movable forward and backward along the axial direction of the piston 52, a detecting cylinder 61 in which the detecting valve 62 is slidably stored, a detecting valve drive part 63, an air passage 64 in which the circuclation of gas is prevented in a state that the detecting valve 62 is moved forward, and the distribution of the gas is allowed in a state that the detecting valve 62 is moved backward, and a detecting part 65 for detecting the pressure of the gas circulating in the air passage 64.

Description

  The present invention relates to a clamping device for fixing a workpiece and a workpiece machining jig.

  Conventionally, workpieces such as a cylinder block and a cylinder head constituting an engine are formed by casting. And the workpiece | work shape | molded by casting is fixed to the pallet as a jig | tool which fixes a workpiece | work, and cutting etc. are given to the workpiece | work of the state fixed to this pallet (refer patent document 1).

As a technique for fixing a workpiece to a pallet, a technique using a clamp device (so-called hole clamp device) has been proposed as an example. The clamp device includes a clamp device main body, a rod portion that is provided so as to be movable forward and backward with respect to the clamp device main body, and has a tapered portion that is formed to gradually increase in diameter toward the distal end side, and a peripheral surface of the rod portion And a grip claw that can be expanded in the radial direction of the tapered portion, and a grip support member that supports the grip claw.
According to the above clamping apparatus, a workpiece | work is fixed in the following procedures.
First, the rod portion and the grip claw positioned at the forward movement position are inserted into the clamp hole of the workpiece. Next, the rod part is retracted. Then, the grip claw supported by the grip support member is enlarged in the radial direction by the taper portion and pressed against the clamp hole. Thereby, a workpiece | work is clamped by the clamp apparatus and is firmly fixed to a pallet.

JP 2011-143530 A

  By the way, a clamp device is provided with the overstroke detection mechanism which detects that it is not a normal clamp state, when a rod part retreats exceeding a predetermined range. Here, in the clamping device proposed in Patent Document 1, in order to secure the clamping force by the grip claw, the grip support member is configured to be movable in the axial direction of the rod portion with a predetermined width (for example, about 1 mm). ing. The overstroke detection mechanism detects an overstroke based on the amount of movement of the grip support member. Therefore, in order to prevent distortion of the workpiece caused by excessively strong clamping force, when the movable width of the grip support member is made extremely small (for example, about 60 μm), the clamping device will be overloaded. The stroke detection mechanism could not be provided.

  Accordingly, an object of the present invention is to provide a clamping device and a workpiece processing jig that can accurately detect an overstroke based on the amount of movement of a rod portion.

  The present invention is a clamp device for fixing a workpiece having a clamp hole provided on a predetermined surface, the clamp device main body facing the clamp hole, the clamp device main body, and a tip portion on the work side. A shaft portion located within the clamp device main body and a tapered portion that is provided at the distal end portion of the shaft portion and has a diameter gradually increased toward the distal end side, and in the axial direction. A rod portion that can move forward and backward, at least a pair of grip claws that cover a part of the peripheral surface of the taper portion and are opposed to each other and are deformable in the radial direction of the taper portion, and a proximal end of the clamp device body A rod drive unit composed of a cylinder part provided on the side, and a piston part slidably disposed on the cylinder part and connected to a base end part of the rod part; And an overstroke detection mechanism that detects that the rod portion has retracted a predetermined distance or more, and the overstroke detection mechanism has the piston portion retracted by a predetermined distance. A detection valve having a detection rod portion that protrudes toward the piston portion side to the position where the tip end side protrudes and can advance and retreat along the axial direction of the piston portion, and a detection piston portion connected to a base end portion of the detection rod portion; A detection cylinder portion in which the detection valve is slidably accommodated, a detection valve drive portion for moving the detection valve forward, and a flow of gas through the detection valve in the state where the detection valve is advanced. Is detected and the pressure of the gas flowing through the air passage is detected while the detection valve is retracted and the gas passage is allowed to flow. A knowledge unit, relates to a clamp device comprising a.

  Further, the rod driving unit is further surrounded by the cylinder unit and the piston unit, and further includes a rod driving fluid pressure chamber into which fluid is introduced and led out, and the detection valve driving unit includes the detection cylinder unit and the detection unit. A detection valve driving fluid pressure chamber surrounded by a piston part and into which fluid is introduced and led out, and a fluid formed in the detection valve and communicating the rod driving fluid pressure chamber and the detection valve driving fluid pressure chamber And a flow path.

  Further, the present invention provides any one of the above-described clamping devices, a reference seat support member that supports a reference seat provided at a position different from the clamp hole in the workpiece, the clamp device, and the reference seat support member. The present invention relates to a workpiece processing jig including a holding jig pallet.

  ADVANTAGE OF THE INVENTION According to this invention, the clamp apparatus and the workpiece | work processing jig | tool which can detect an overstroke precisely based on the moving amount | distance of a rod part can be provided.

It is a top view which shows the jig | tool for workpiece | work processing which concerns on one Embodiment of this invention. It is a front view which shows the state which looked at the jig | tool for workpiece processing which concerns on one Embodiment of this invention from the A arrow direction of FIG. It is an external appearance perspective view which shows the state by which the workpiece | work is being fixed (clamped) to the jig | tool palette by the clamp apparatus which concerns on one Embodiment of this invention. It is a figure which shows the gasket surface of the cylinder head shown in FIG. It is a figure which shows the cross section of a clamp apparatus, and is BB arrow sectional drawing of FIG. It is a longitudinal cross-sectional view which shows the overstroke detection mechanism in the clamp apparatus of this invention, and is the elements on larger scale of FIG. It is a figure which shows the state which the grip nail | claw and pull rod of the clamp apparatus shown in FIG. 5 approached into the clamp hole shown in FIG. FIG. 6 is a longitudinal sectional view showing a state in which the clamping device shown in FIG. 5 normally fixes (clamps) the cylinder head shown in FIG. 3. It is a longitudinal cross-sectional view of the clamp apparatus which shows the state which the pull rod shown in FIG. 5 overstroked. It is a longitudinal cross-sectional view of the overstroke detection mechanism which shows the state which the pull rod shown in FIG. 5 overstroked.

  Hereinafter, a preferred embodiment of a clamping device and a workpiece processing jig of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view showing a workpiece machining jig 100 according to an embodiment of the present invention. FIG. 2 is a front view showing a state in which the workpiece machining jig 100 according to the embodiment of the present invention is viewed from the direction of arrow A in FIG.
The workpiece machining jig 100 of the present embodiment fixes (clamps) and releases the cylinder head W when cutting or the like is performed on the cylinder head W as a workpiece provided with a clamp hole. Used when (unclamping). As shown in FIGS. 1 and 2, the workpiece machining jig 100 includes a jig pallet P, a plurality (three) of reference seat support members 110 and a plurality (three) ) Clamping device 1.

First, the cylinder head W as a workpiece of this embodiment will be described.
FIG. 3 is an external perspective view showing a state in which the cylinder head W according to the embodiment of the present invention is fixed (clamped) to the jig pallet P by the clamping device 1. 4 is a view showing the gasket surface Ga of the cylinder head W shown in FIG.

  The cylinder head W is a cast product that is connected to a cylinder head cover, a cylinder block, and the like and constitutes a part of an engine mounted on an automobile or the like, and has a gasket surface Ga on the cylinder block side. On the gasket surface Ga of the cylinder head W or in the vicinity thereof, as shown in FIG. 4, three reference seats 3 and cast holes 2 for positioning used as three are formed.

The reference seat 3 is used for positioning the cylinder head W in the height direction when the cylinder head W is fixed to the jig pallet P. These reference seats 3 become reference surfaces in the height direction when the clamping device 1 is disposed below the cylinder head W with the gasket surface Ga of the cylinder head W as the lower surface.
Further, as shown in FIG. 4, two reference seats 3 are formed in the vicinity of both end portions of one side edge of the pair of side edges along the longitudinal direction of the gasket surface Ga having a substantially rectangular shape. One is formed near the center of the side edge.

The three punched holes 2 are used for fixing the cylinder head W when the cylinder head W is fixed to the jig pallet P.
The three cast holes 2 correspond to the arrangement of the reference seat 3, one in the vicinity of the center of one side edge of the pair of side edges along the longitudinal direction of the gasket surface Ga having a substantially rectangular shape. Two are formed near both ends of the other side edge. That is, one casting hole 2 is formed in the vicinity of the middle of the two reference seats 3 on the one side edge described above, and one reference hole is formed in the middle of the two casting holes 2 on the other side edge. A seat 3 is formed.
Further, these three cast holes 2 are cast holes formed at positions where cast pins formed in the mold are provided in the casting process of the cylinder head 1. The cast hole is formed in a truncated cone shape with a draft angle so that the cast pin can be easily removed from the mold (see FIGS. 7 to 9).

Next, the workpiece machining jig 100 and the clamping device 1 will be described.
As described above, the workpiece machining jig 100 includes the jig pallet P, the three reference seat support members 110, and the three clamp devices 1.

The jig pallet P is configured in a rectangular flat plate shape. The jig pallet P is formed with pressure oil passages PO1 and PO2 for supplying the pressure oil O to the clamp device 1 and a compressed air passage PA1 for supplying compressed air to the clamp device 1 (see FIG. 2).
The reference seat support member 110 is a member that seats the cylinder head W and supports the cylinder head W on the jig pallet P. The reference seat support member 110 includes a main body 111 formed by cutting a hollow cone from its height direction and having a size more than half of the hollow cone, and extending upward from the top of the main body 111. And a seat portion 112 that constitutes a seating surface that contacts the reference seat 3. In the present embodiment, the reference seat support members 110 are arranged at three locations on the upper surface of the jig pallet P. These three reference seat support members 7 are arranged at positions corresponding to the three reference seats 3 when the cylinder head W is placed on the upper surface of the jig pallet P.

FIG. 5 is a cross-sectional view taken along the line BB in FIG. 1 illustrating the clamp device 1 according to the present embodiment.
As shown in FIG. 1, the clamp device 1 is fixed at three locations on the upper surface of the jig pallet P. These three clamping devices 1 are arranged at positions corresponding to the three cast holes 2 when the cylinder head W is placed on the upper surface of the jig pallet P.

As shown in FIG. 5, the clamp device 1 includes a clamp device body 10, a pull rod 20 as a rod portion, a grip 30 having a grip claw 31, a grip support member 40, and a rod drive source 50 as a rod drive portion. And an overstroke detection mechanism 60.
The clamp device main body 10 includes a lower main body 11 and an upper main body 12 disposed on the upper portion of the lower main body 11.

The lower main body 11 is formed in an upward cup shape, and includes a bottom portion 11a and a cylinder mounting hole 11b to which a rod driving source 50 including a cylinder portion 51 described later is mounted.
The upper body 12 has a through hole 12a through which the grip 30 and the pull rod 20 are inserted. The tip (upper end) side of the upper body 12 has a shape protruding upward.

  The pull rod 20 is an axial member that moves forward and backward (lifts and lowers) in the axial direction by the driving force of the rod drive source 50 and expands and contracts the grip 30 in the radial direction. The pull rod 20 has a distal end portion located on the outer side of the clamp device body 10 and a proximal end portion provided on the inner side of the clamp device body 10 and a distal end portion of the shaft portion 21. A tapered portion 22 having a diameter gradually increased toward the side.

  The grip 30 is disposed around the vicinity of the boundary portion between the shaft portion 21 and the taper portion 22 of the pull rod 20. The grip 30 covers a part of the peripheral surface of the taper portion 22 and is attached to two pairs of grip claws 31 disposed opposite to each other and the base end portions of the grip claws 31 to bring the grip claws 31 closer to each other. And a converging spring (O-ring) 32 having a C-shape in a plan view and biasing in the direction.

The grip claw 31 has a tapered surface 311 having a diameter gradually increasing from the proximal end side toward the distal end side on the surface facing the taper portion 22 of the pull rod 20, and the pull rod 20 on the outer surface of the grip claw 31. And a plurality of (two) protrusions 312 formed along the axial direction. Further, the grip claws 31 are arranged to face each other so as to cover an approximately (1/4) part of the circumference of the taper portion 22 of the pull rod 20, and the taper portion 22 tapers as the pull rod 20 descends. The surface 311 is slid so as to spread radially against the focusing spring 32.
The two protrusions 312 are formed on the outer surfaces of the grip claws 31. Thereby, when clamping the core hole 2, the grip claw 31 is prevented from sliding with respect to the core hole 2, and a grip force is generated.

  The grip support member 40 is located inside the upper main body 12 and supports the grip 30 from below the grip 30. The grip support member 40 is a downward cup-shaped member provided downward from the through hole 12 a in the upper body 12. The grip support member 40 is formed with a through hole 40a through which the pull rod 20 passes. In the present embodiment, the grip support member 40 is disposed inside the clamp apparatus body 10 so that the movable width in the axial direction of the pull rod 20 is extremely small (for example, about 60 μm).

  The rod drive source 50 is a drive source that drives the pull rod 20 to a clamp position or an unclamp position. Here, the clamp position is a position where the pull rod 20 is retracted (lowered), the grip 30 is spread, and the cylinder head W is fixed (clamped) to the jig pallet P by the grip 30. The unclamping position is a position where the pull rod 20 moves forward (ascends), the grip 30 is squeezed, and the fixing by the grip 30 is released (unclamped).

  The rod drive source 50 includes a cylinder portion 51, a piston portion 52, and a first hydraulic chamber 53 and a second hydraulic chamber 54 as rod driving fluid pressure chambers.

  The cylinder portion 51 is formed in a cylindrical shape that is fixedly fitted in the lower main body 11, and is positioned above the bottom portion 11 a of the lower main body 11 inside the clamp device main body 10.

The piston part 52 includes a piston body 52a and a lid part 52b.
The piston main body 52 a constitutes a main part of the piston portion 52. The piston main body 52a includes a small-diameter upper piston 521, a large-diameter lower piston 522, and a rod insertion hole 523.

  The upper piston 521 is provided on the base end side of the shaft portion 21 of the pull rod 20 and is connected to the shaft portion 21. The upper piston 521 is configured to be slidable with respect to the grip support member 40 while being in contact with the inner surface of the grip support member 40, and is provided so as not to move in a direction crossing the sliding direction. Yes. The inner diameter of the upper piston 521 is configured to be slightly larger than the outer diameter of the pull rod 20 at a position corresponding to the upper piston 521.

The lower piston 522 is provided on the opposite side of the pull rod 20 with respect to the upper piston 521. The outer diameter of the lower piston 522 is substantially equal to the inner diameter of the cylinder portion 51. That is, the lower piston 522 is configured to be slidable with respect to the cylinder part 51 in a state of being in contact with the inner surface of the cylinder part 51, and is provided so as not to move in a direction intersecting the sliding direction. . The inner diameter of the lower piston 522 is configured to be slightly larger than the outer diameter of a position (base end portion) corresponding to the lower piston 522 in the pull rod 20.
The rod insertion hole 523 is formed through the piston main body 52a in the vertical direction. The rod insertion hole 523 has an inner diameter portion equivalent to the maximum diameter of the pull rod 20. In the clamping device 1 of the present embodiment, the pull rod 20 is inserted from the rod insertion hole 523.

The lid portion 52 b is disposed below the rod insertion hole 523 and closes the rod insertion hole 523. The upper surface of the lid portion 52b abuts on the base end surface of the pull rod 20 and supports the pull rod 20.
The lid 52b is fixed to the piston main body 52a in a state where the rod insertion hole 523 is closed by a snap ring (not shown) arranged on the lower surface side of the lid 52b.

  The first hydraulic chamber 53 is configured by a region surrounded by the bottom portion 11 a of the lower body 11 of the clamp device body 10, the lower surface of the lower piston 522, the lower surface of the lid portion 52 b, and the inner peripheral surface of the cylinder portion 51. The first hydraulic chamber 53 communicates with a pressure oil passage PO1 formed in the jig pallet P through an unclamp port 113 formed in the bottom 11a of the lower main body 11 (see FIG. 2). As a result, the pressure oil O is supplied from the pressure oil passage PO1 to the first hydraulic chamber 53, and when the hydraulic pressure in the first hydraulic chamber 53 increases, the piston portion 52 rises (forwards).

  The second hydraulic chamber 54 is configured by a region surrounded by the lower end surface of the grip support member 40, the side surface of the upper piston 521, the upper surface of the lower piston 522, and the inner peripheral surface of the cylinder portion 51 (see FIG. 8). The second hydraulic chamber 54 communicates with a pressure oil passage PO2 formed in the jig pallet P via a clamp pressure oil passage 114 formed in the lower main body 11 and the upper main body 12. As a result, the pressure oil O is supplied from the pressure oil passage PO2 to the second hydraulic chamber 54, and when the hydraulic pressure in the second hydraulic chamber 54 increases, the piston portion 52 descends (retreats).

  According to the rod drive source 50 described above, when the pressure oil O is supplied to the first hydraulic chamber 53, the piston portion 52 rises to raise the pull rod 20 to the unclamping position (see FIG. 6). Further, when the pressure oil O is supplied to the second hydraulic chamber 54, the piston portion 52 is lowered to lower the pull rod 20 to the clamp position (see FIG. 8). That is, it is possible to raise or lower the piston portion 52 and stop the movement thereof by hydraulic control of the first hydraulic chamber 53 and the second hydraulic chamber 54.

FIG. 6 is a longitudinal sectional view showing the overstroke detection mechanism 60.
The overstroke detection mechanism 60 detects a stroke longer than the normal downward stroke that occurs when the piston portion 52 (lid portion 52b) connected to the pull rod 20 shifts from the unclamped state to the clamped state, that is, the overstroke of the pull rod 20. Used to do. The overstroke detection mechanism 60 is attached to the bottom 11a of the lower main body 11.

  The overstroke detection mechanism 60 includes a detection cylinder portion 61, a detection valve 62 slidably disposed in the detection cylinder portion 61, a detection valve drive portion 63 that drives the detection valve, an air passage 64, and a detection Unit 65.

The detection cylinder unit 61 includes an upper cylinder unit 611 and a lower cylinder unit 612.
The upper cylinder part 611 is located on the first hydraulic chamber 53 side (upward) in the bottom part 11 a of the lower body 11. In the upper cylinder portion 611, a rod insertion hole 611a and a part of the air passage 64 are formed. The rod insertion hole 611a extends in the forward / backward (up / down) direction of the pull rod 20. A detection valve 62 (a detection rod portion 621 described later) is inserted into the rod insertion hole 611a. Details of the air passage 64 will be described later.
In the present embodiment, the upper cylinder portion 611 is formed in a disc shape in which one surface is recessed and a rod insertion hole 611a is formed in the thickness direction. The upper cylinder part 611 is disposed so that the surface on which the recess is formed faces downward.

  The lower cylinder part 612 is disposed on the opposite side (downward) of the first hydraulic chamber 53 with respect to the upper cylinder part 611. The lower cylinder part 612 is formed in a cylindrical shape. The lower cylinder portion 612 is formed with a hole portion 612a that is recessed downward on one surface (upper surface), and a part of the air passage 64 is formed. The lower cylinder portion 612 is disposed such that the surface on which the hole portion 612a is formed contacts the lower surface of the upper cylinder portion 611.

The detection valve 62 includes a detection rod portion 621 and a detection piston portion 622.
The detection rod portion 621 extends in the forward / backward (up / down) direction of the pull rod 20 and is inserted into the rod insertion hole 611a of the upper cylinder portion 611. In addition, a through hole through which the detection rod portion 621 can be inserted is formed in the bottom portion 11a of the lower main body 11, and the distal end side of the detection rod portion 621 projects upward from the upper surface of the bottom portion 11a of the lower main body 11. 1 Exposed to the hydraulic chamber 53.

The detection rod portion 621 includes a contact surface 621a, an internal oil passage 621b as a fluid passage, and an oil passage inlet / outlet 621c.
The contact surface 621a is provided at the tip of the detection rod portion 621, and comes into contact with the lid portion 52b during the overstroke of the pull rod 20 (piston portion 52).
The internal oil passage 621 b extends along the axial direction of the detection valve 62 inside the detection valve 62.
The oil passage inlet / outlet 621c is a portion exposed to the first hydraulic chamber 53 on the distal end side of the detection rod portion 621, and is provided in a portion other than the contact surface 621a. The oil passage inlet / outlet 621c is an inlet / outlet of the pressure oil O between the first hydraulic chamber 53 and the internal oil passage 621b.

The detection piston part 622 is located on the opposite side (downward) of the first hydraulic chamber 53 with respect to the detection rod part 621. The detection piston portion 622 is formed in a cylindrical shape, and is slidably disposed in the hole 612a of the lower cylinder portion 612.
The detection piston portion 622 comes into close contact with the lower surface of the upper cylinder portion 611 in a state where the detection rod portion 621 is raised most. Further, an internal oil passage 612 b provided in the detection rod portion 621 passes through the inside of the detection piston portion 622 and communicates with a third hydraulic chamber 631 described later.

The detection valve drive unit 63 includes the oil passage inlet / outlet 621c and the internal oil passage 621b, and the third hydraulic chamber 631.
The third hydraulic chamber 631 is configured by a region surrounded by the hole 612 a of the lower cylinder portion 612 and the lower surface of the detection piston portion 622. The third hydraulic chamber 631 communicates with the first hydraulic chamber 53 via the oil passage inlet / outlet 621c and the internal oil passage 621b. That is, the hydraulic pressure in the third hydraulic chamber 631 is equal to the hydraulic pressure in the first hydraulic chamber 53. Further, the area of the lower surface of the detection piston part 622 is larger than the area of the contact surface 621a of the detection rod part 621. Thereby, when the pressure oil O is supplied to the first hydraulic chamber 53, the supplied pressure oil O is supplied to the third hydraulic chamber 631 through the oil passage inlet / outlet 621c and the internal oil passage 621b. Then, the detection valve 62 moves forward (rises) by the pressure of the pressure oil O supplied to the third hydraulic chamber 631.
Further, when the pull rod 20 and the piston portion 52 are retracted (lowered) and the detection valve 62 is pressed by the lid portion 52b, the pressure oil O accommodated in the third hydraulic chamber 631 is transferred to the internal oil passage 621b and the oil. The detection valve 62 descends to the first hydraulic chamber 53 through the path inlet / outlet 621c.

  The air passage 64 includes a lower air passage 641, an upper air passage 642, and an opening / closing passage 643.

  The lower air passage 641 is provided so as to penetrate the lower cylinder portion 612 in the vertical direction, and compressed air flows into the upper cylinder portion 611 from the outside of the lower cylinder portion 612. An air compressor (not shown) is connected to the lower air passage 641 through a compressed air passage PA1 to supply compressed air to the lower air passage 641.

  The upper air passage 642 is formed in the upper cylinder portion 611 and extends in the radial direction of the upper cylinder portion 611. The upper air passage 642 communicates with the rod insertion hole 611 a and also communicates with a detection unit 65 described later via a main body passage 644 formed in the lower main body 11.

  The opening / closing passage 643 allows the lower air passage 641 and the upper air passage 642 to communicate with each other. The opening / closing passage 643 is formed by a region surrounded by the upper surface of the lower cylinder portion 612, the portion where the recess in the upper cylinder portion 611 is formed, the rod insertion hole 611 a, and the detection valve 62.

  As shown in FIG. 6, the open / close passage 643 is closed by the detection valve 62 in a state where the detection valve 62 moves forward (rises), and the flow of compressed air from the lower air passage 641 to the upper air passage 642 is obstructed. The More specifically, in a state in which the detection valve 62 has moved forward, the upper surface of the detection piston portion 622 comes into close contact with the lower surface of the upper cylinder portion 611 and closes the open / close passage 643.

  On the other hand, the open / close passage 643 allows compressed air to flow from the lower air passage 641 to the upper air passage 642 when the detection valve 62 is retracted (lowered) (see FIG. 10). More specifically, in a state where the detection valve 62 is retracted, the upper surface of the detection piston portion 622 is separated from the lower surface of the upper cylinder portion 611, so that the open / close passage 643 is opened.

  The detector 65 measures the air pressure passing through the air passage 64. The open / close state of the air passage 64 can be detected by measuring the air pressure by the detector 65.

  As in the prior art, the clamping device 1 is provided with an O-ring 90 at a contact portion between the components in order to maintain airtightness or oiltightness.

Next, the operation of the clamping device 1 will be described.
FIG. 7 is a diagram illustrating a state in which the grip claw 31 and the pull rod 20 of the clamping device 1 have entered the core hole 2 of the cylinder head W, and is a diagram illustrating an unclamped state of the clamping device 1. FIG. 8 is a longitudinal sectional view showing a state in which the clamp device 1 normally fixes (clamps) the cylinder head W. FIG. 9 is a longitudinal sectional view of the clamping device 1 showing a state where the pull rod 20 has overstroked. FIG. 10 is an enlarged view of the overstroke detection mechanism 60 portion in FIG.

  When the cylinder head W is fixed to the jig pallet P, as shown in FIG. 7, the pressure oil O is supplied from the pressure oil passage PO1 to the first hydraulic chamber 53 and the pressure oil is supplied from the second hydraulic chamber 54. The pressure oil O is discharged through the passage PO2. As a result, the hydraulic pressure in the first hydraulic chamber 53 is greater than the hydraulic pressure in the second hydraulic chamber 54, and the pull rod 20 connected to the piston portion 52 is raised. Then, the tapered portion 22 of the pull rod 20 moves above the grip 30 and the spring force of the focusing spring 32 brings the grip claws 31 of the grip 30 closer to each other. As a result, the grip 30 can be inserted into the cast hole 2. In this state, the hydraulic pressure of the first hydraulic chamber 53 is maintained, and the rising state of the piston portion 52 is maintained.

  In the unclamped state of the clamp device 1, the detection valve 62 is maintained in the forward (raised) state by the pressure of the pressure oil O supplied from the first hydraulic chamber 53 to the third hydraulic chamber 631. In this state, the upper surface of the detection piston portion 622 is in contact with the lower surface of the upper cylinder portion 611, and the open / close passage 643 is closed. As a result, the flow of compressed air supplied from the air compressor (not shown) to the lower air passage 641 is inhibited by the detection valve 62, so that the compressed air flows into the upper air passage 642 and the main body passage 644. The detector 65 does not detect the air flow. That is, the overstroke detection mechanism 60 does not operate (see FIG. 6).

Next, the cylinder head W is placed at a predetermined position on the jig pallet P. Then, as shown in FIG. 2, the reference seat support member 110 attached to the jig pallet P abuts on the reference seat 3 of the cylinder head W, and the pull rod 20 of the clamp device 1 attached to the jig pallet P The tapered portion 22 and the grip 30 are inserted into the cast hole 2 of the cylinder head W.
When the cylinder head W is placed on the jig pallet P, the pressure oil O is supplied to the second hydraulic chamber 54. Then, as shown in FIG. 8, the hydraulic pressure in the second hydraulic chamber 54 increases and the pull rod 20 connected to the piston portion 52 descends. As a result, the taper portion 22 of the pull rod 20 that descends enters the inside of the grip claw 31 of the grip 30, spreads the grip claw 31 in the radial direction, and presses it against the inner wall of the cast hole 2.

  Here, when the clamping is normally performed, when the grip claw 31 is pressed against the inner peripheral surface of the punched hole 2 and cannot be further expanded in the radial direction, the grip claw 31 enters the cast hole 2. On the other hand, a strong fixing force is generated. Thereby, the cylinder head W is fixed to the jig pallet P. In this case, the pull rod 20 cannot travel beyond the normal stroke range, and the distance between the piston portion 52 (lid portion 52b) connected to the pull rod 20 and the tip of the detection valve 62 is kept at an overstroke allowable distance or more. Therefore, the overstroke detection mechanism 60 does not operate (see FIG. 8).

On the other hand, even if the pull rod 20 descends within the range of the normal stroke of the pull rod 20 because the cast hole 2 is formed larger than a predetermined size, the grip 30 covers the inner wall of the cast hole 2. When it cannot be normally pressed, the pull rod 20 descends beyond the normal stroke range as shown in FIG. 9, and the pull rod 20 overstrokes.
If the pull rod 20 overstrokes beyond the allowable overstroke distance, the lid 52b continues to descend even if it comes into contact with the detection valve 62, so that the detection valve 62 descends (retreats) from the maximum ascent position as shown in FIG. . Then, the open / close passage 643 closed by the detection valve 62 is opened, and the compressed air supplied from the air compressor (not shown) to the lower air passage 641 is supplied to the open / close passage 643, the upper air passage 642, and the main body passage. The flow of 644 reaches the detection unit 135, and the flow of this compressed air is detected by the detection unit 135. Thereby, the overstroke of the clamp apparatus 1 is detected.

  According to the clamping device 1 and the workpiece machining jig 100 of the present embodiment described above, the following effects are obtained.

  (1) The overstroke detection mechanism 60 is disposed closer to the proximal end side of the clamp device body 10 than the piston portion 52, and the overstroke detection mechanism 60 can be advanced and retracted along the axial direction of the piston portion 52. When the detection valve 62 moves forward, the flow of compressed air is hindered, and when the detection valve 62 moves backward, the flow of compressed air is allowed, and the pressure of the gas flowing through the air passage 64 And a detection unit 65 that detects. As a result, the overstroke detection mechanism 60 can be operated by utilizing the advance / retreat of the piston portion 52 that moves following the advance / retreat of the pull rod 20, so that the overstroke can be accurately detected.

  (2) The detection valve drive unit 63 includes a third hydraulic chamber 631, and an oil passage inlet / outlet 621c and an internal oil passage 621b that allow the third hydraulic chamber 631 and the first hydraulic chamber 53 to communicate with each other. Accordingly, the pressure oil O supplied to the first hydraulic chamber 53 can be supplied to the third hydraulic chamber 631 via the oil passage inlet / outlet 621c and the internal oil passage 621b, and the pressure oil O supplied to the third hydraulic chamber 631 is supplied. With this pressure, the detection valve 62 can be advanced (raised). Therefore, since the overstroke detection mechanism 60 can be configured without using any additional power, energy consumption when operating the clamp device 1 can be reduced.

  (3) In the conventional clamping device, in order to secure a clamping force, the grip support member is configured to be movable in the axial direction of the pull rod with a predetermined width (for example, about 1 mm). An overstroke detection mechanism for detecting an overstroke according to the amount has been provided. On the other hand, in the clamping device 1 of the present embodiment, the movable width of the grip support member 40 is extremely small (for example, about 60 μm) in order to prevent distortion of the cylinder head W due to excessive clamping force. )It is configured. Therefore, the overstroke detection mechanism 60 is arranged in the lower main body 11 to configure the clamp device 1. Thereby, since the overstroke detection mechanism 60 can be configured without being affected by the movable width of the grip support member 40, the setting range of the strength of the clamping force by the clamping device 1 can be expanded. As a result, for example, even in the clamp device 1 used for the workpiece machining jig 100 for fixing the cylinder head W which is provided at a position where the punched hole 2 and the reference seat 3 are different from each other and which is likely to be distorted, A simple overstroke detection mechanism 60 can be realized.

As mentioned above, although preferable embodiment of the jig | tool 100 for workpiece processing and the clamp apparatus 1 of this invention was described, this invention can be implemented with a various form, without being restrict | limited to embodiment mentioned above.
For example, in the present embodiment, the raising and lowering of the pull rod 20 is controlled by the hydraulic pressure of the first hydraulic chamber 53 and the second hydraulic chamber 54, and the raising of the detection valve 62 is controlled by the hydraulic pressure of the third hydraulic chamber 631, but this is not limitative. Absent. That is, only the pull-down of the pull rod is hydraulically controlled, a spring is arranged in each region corresponding to the first hydraulic chamber and the third hydraulic chamber, and the elastic force is driven to raise the pull rod and the detection valve. Also good. If the fixing force can be sufficiently exerted, the pull rod rise and the detection valve rise are hydraulically controlled, and a spring is arranged in a region corresponding to the second hydraulic chamber to drive the elastic force to drive the pull rod. A descent may be performed.

  Moreover, although the clamp apparatus 1 was operated with the pressure oil O in this embodiment, it is not restricted to this. That is, the clamping device may be operated by compressed air.

  In the present embodiment, the clamping device 1 is provided on the jig pallet P and the cylinder head W is fixed to the jig pallet P. However, the present invention is not limited to this. That is, the clamping device may be provided on a moving body such as a carriage or a vehicle that moves the cylinder head.

1 Clamping device 2 Cast hole (clamp hole)
3 Reference seat 10 Clamping device body 20 Pull rod (rod part)
21 Shaft 22 Taper 30 Grip 31 Grip Claw 50 Rod Drive Source (Rod Drive)
51 Cylinder part 52 Piston part 53 First hydraulic chamber (rod pressure flow chamber)
54 Second hydraulic chamber (rod pressure flow chamber)
60 Overstroke Detection Mechanism 61 Detection Cylinder Unit 62 Detection Valve 63 Detection Valve Drive Unit 64 Air Passage 65 Detection Unit 100 Workpiece Processing Jig 110 Reference Seat Support Member 621 Detection Rod Portion 621b Internal Oil Path (Fluid Channel)
621c Oil passage entrance (fluid flow passage)
622 Detection piston portion 631 Third hydraulic chamber (flow pressure chamber for detecting valve driving)
P Jig pallet O Pressure oil W Cylinder head (workpiece)

Claims (3)

A clamping device for fixing a workpiece having a clamp hole on a predetermined surface,
A clamp device body facing the clamp hole;
Provided in the clamp device main body, a tip portion located on the workpiece side and a base end portion located in the clamp device main body, and a tip portion provided on the tip portion of the shaft portion gradually toward the tip side. A rod portion that has a tapered portion formed with a large diameter and that can advance and retreat along the axial direction;
Covering at least a part of the peripheral surface of the taper portion, and being disposed facing each other, at least a pair of grip claws capable of being deformed in the radial direction of the taper portion; and
A rod drive unit configured by a cylinder part provided on the proximal end side of the clamp device body, and a piston part slidably disposed on the cylinder part and connected to the proximal end part of the rod part;
An overstroke detection mechanism that is disposed closer to the base end side of the clamp device body than the piston portion and detects that the rod portion has retracted more than a predetermined distance;
The overstroke detection mechanism is
A detection rod portion that protrudes toward the piston portion side to a position where the piston portion is retracted by a predetermined distance and can advance and retreat along the axial direction of the piston portion, and a detection that is connected to a proximal end portion of the detection rod portion A detection valve having a piston portion;
A detection cylinder portion in which the detection valve is slidably accommodated;
A detection valve drive for advancing the detection valve;
An air passage formed in the detection cylinder portion, in which the flow of gas is inhibited by the detection valve in a state in which the detection valve is advanced, and in which the flow of gas is allowed in the state in which the detection valve is retracted;
And a detection unit that detects the pressure of the gas flowing through the air passage. The rod driving part further includes a rod driving fluid pressure chamber surrounded by the cylinder part and the piston part, into which fluid is introduced and led out,
The detection valve drive unit is
A detection valve driving fluid pressure chamber surrounded by the detection cylinder part and the detection piston part and into which fluid is introduced and led out;
The clamp device according to claim 1, further comprising: a fluid flow path formed in the detection valve and communicating the rod driving fluid pressure chamber and the detection valve driving fluid pressure chamber. The clamping device according to claim 1 or 2,
A reference seat support member for supporting a reference seat provided at a position different from the clamp hole in the workpiece;
A workpiece processing jig comprising: the clamp device and a jig pallet that holds the reference seat support member.

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