JP2014042966A - Clamping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a clamping device that can eliminate at least a portion of an exhaust passage for exhausting a pressurized air for detection, and is advantageous for compactification and reduction of production costs.SOLUTION: A clamping device includes: a clamp body 1; a first working chamber 21 for driving a piston member 20 for outputting a clamping force to a clamping position by a pressurized air; a second working chamber 22 for driving the piston member 20 to an unclamping position by the pressurized air; and an air supply passage 50 connected to an outside pressurized air resource. The clamping device can detect an operation condition through the air pressure of the air supply passage 50, and is provided with a first air passage 54 for connecting the air supply passage 50 to the second working chamber 22 and a first on-off valve mechanism 55 interposed to the first air passage 54 and valve-opening on the occurrence of a first operation condition. When the first operation condition occurs and the first on-off valve mechanism 55 is valve-opened in a clamp operation condition supplying the pressurized air to the first working chamber 21, the pressurized air for detection is exhausted to the second working chamber 22 through the first air passage 54.

Description

  The present invention relates to a clamp device of a type driven by pressurized air, and more particularly to a clamp device of a type for gripping and fixing the inner peripheral surface of a hole in a workpiece, and a discharge structure for detecting pressurized air for detecting an operating state The present invention relates to an improved clamping device.

Various clamping devices driven by fluid pressure have been put into practical use. In these clamping devices, an air supply passage connected to a pressurized air supply source is provided in the clamping device, and the pressurized air in the air supply passage is provided. A detection mechanism that detects the operating state of the clamp device from the pressure state through or without the on-off valve mechanism is also employed.
For example, there is a seating detection mechanism that detects that the workpiece is normally seated on the seating surface at the time of clamping, a clamp failure detection mechanism that detects the occurrence of a clamping error, a detection mechanism that detects the clamp operation state and the unclamp operation state, etc. It has been adopted.

  The clamp device disclosed in Patent Document 1 includes a clamp body, a grip member protruding upward from an insertion hole in an upper end portion of the clamp body, a clamp rod engaged inside the grip member, and a grip member from below. It is a hole clamp (or expansion clamp) provided with a support mechanism to support and a hydraulic cylinder that drives the clamp rod up and down.

  A grip member and a clamp rod are inserted into a hole of a workpiece used for machining, and the inner peripheral surface of the hole is clamped by expanding the diameter of the grip member with a clamp rod driven by a fluid pressure cylinder. In this clamping device, a scraper that closes the outer peripheral side of the grip member and the clamp rod is attached to the insertion hole so that chips and cutting fluid generated by machining the workpiece do not enter the inside of the clamping device, and the air supply passage An air blow mechanism is provided that introduces pressurized air supplied from the inside of the clamp device and ejects it from a gap between the clamp member, the clamp rod, and the scraper.

Furthermore, a seating surface for seating the workpiece is formed at the upper end of the clamp body, one end of the air supply passage formed in the clamp body is opened to the seating surface, and the seating of the workpiece is performed from the air pressure of the pressurized air in the air supply passage. A seating detection mechanism is provided to detect this.
In addition, it has a branch air passage that branches from the air supply passage into the clamping device, and an on-off valve mechanism that opens and closes the branch air passage, and an annular pressure receiving pressure of the support mechanism when a clamping error such as slip of the grip member occurs. By opening the on-off valve mechanism with a member, there is provided a clamp failure detection mechanism that detects a clamp failure from the pressure drop of the pressurized air in the branch air passage and the air supply passage. In this clamping error detection mechanism, when the on-off valve mechanism is opened due to the occurrence of a clamping error, the detection pressurized air in the branch air passage is supplied to the air passage of the air blow mechanism in the clamp device (various gaps in the clamp body). It discharges to the passage which consists of.

  The clamp device disclosed in Patent Document 2 is the same clamp device as the hole clamp disclosed in Patent Document 1, but the structure of the clamp body is slightly different in order to enhance the versatility of the clamp device. In this clamp device, in order to reduce the consumption of pressurized air by the air blow mechanism as much as possible, the shape of the grip member and the clamp rod is devised, and the clamp rod and the grip are moved from the unclamped state to the clamped state. It is comprised so that a clearance gap may hardly arise between a member and a scraper.

WO2009 / 101765 Publication WO2011 / 108352 publication

  In a detection mechanism such as a clamp failure detection mechanism described in Patent Document 1, pressurized air for detection is exhausted to an air passage for air blow in the clamp body when the on-off valve mechanism is opened. However, in the case of a configuration in which almost no gap is generated between the clamp rod and the grip member and the scraper from the unclamped state to the clamped state as in the clamp device of Patent Document 2, the pressurized air for detection is used. When air is exhausted to the air passage for air blow in the clamp body, the air pressure in the branch air passage does not necessarily drop, and there is a possibility that the detection performance for detecting a clamping error may be lowered. Therefore, it is necessary to form an exhaust passage for exhausting the detection pressurized air in the clamp device. Therefore, the design of the exhaust passage becomes complicated, the processing cost of the exhaust passage becomes expensive, and it is disadvantageous for making the clamp device compact.

  An object of the present invention is to provide a clamp device that can omit at least a part of an exhaust passage that exhausts pressurized air for detection, and to provide a clamp device that is advantageous in reducing the size and manufacturing costs. , Etc.

  According to a first aspect of the present invention, there is provided a clamping device, a first working chamber for driving a clamping force output piston member to a clamping position with pressurized air, and a first actuator for driving the piston member to an unclamping position with pressurized air. Two working chambers, an air supply passage formed in the clamp body and connected to an external pressurized air supply source, and a clamp device capable of detecting an operating state via the air pressure of the air supply passage, wherein the air supply A first air passage that connects the passage to the second working chamber; and a first on-off valve mechanism that is interposed in the first air passage and opens when the first operating state occurs. The detection pressurized air is discharged to the second working chamber via the first air passage when the first operating state occurs and the first on-off valve mechanism is opened in the clamp operating state supplied with It is characterized by .

  According to a second aspect of the present invention, there is provided the clamping device according to the first aspect, wherein the second air passage connecting the air supply passage to the first working chamber and the second air passage are opened when the second operation state occurs. A second on-off valve mechanism, and in the unclamping operating state in which the pressurized air is supplied to the second working chamber, the pressurized air for detection when the second operating state occurs and the second on-off valve mechanism opens. Is configured to be discharged to the first working chamber through the second air passage.

  According to a third aspect of the present invention, there is provided the gripping device according to the first or second aspect, wherein the grip member extends upward through the insertion hole in the upper end portion of the clamp main body and grips the inner peripheral surface of the hole of the workpiece. A clamp rod engaged with the member and a support mechanism for supporting the grip member with fluid pressure or the elastic force of a spring are provided.

  According to a fourth aspect of the present invention, there is provided the clamp device according to the third aspect, wherein the support mechanism is a support member that supports the lower end of the grip member and an annular pressure receiving member that receives the pressurized air from the first working chamber and supports the support member. It is characterized by having.

  According to a fifth aspect of the present invention, in the clamp device according to the third aspect, the first operating state is a state in which the grip member slips with respect to the workpiece when the clamping operation starts and the annular pressure receiving member descends to the lower limit position. The annular pressure receiving member is configured to open the first on-off valve mechanism when one operating state occurs.

  According to a sixth aspect of the present invention, in the invention of the third aspect, the second operating state is a state in which the piston member is in an unclamped state, and the piston portion of the piston member is second when the second operating state occurs. The on / off valve mechanism is configured to open.

  According to a seventh aspect of the present invention, there is provided a clamping device according to the sixth aspect of the invention, wherein the clamping device is a seating detection air passage formed in the clamp body and connected to the air supply passage. An opening seat detection air passage is provided.

  The clamp device according to claim 8 includes a clamp body, a first working chamber that drives a piston member for clamping force output in a forward direction in which a piston rod retracts by pressurized air, and the piston member by pressurized air. It has a second working chamber that drives in the reverse direction opposite to the forward direction, and an air supply passage connected to an external pressurized air supply source, and detects the operating state via the air pressure in this air supply passage In a possible clamping device, a third air passage that connects the air supply passage to the second working chamber, and a third on-off valve that is interposed in the third air passage and opens when the piston member reaches the forward movement limit position And when the third on-off valve mechanism opens when the piston member reaches the forward movement limit position, the pressurized air for detection is discharged to the second working chamber via the third air passage. It is characterized by the construction.

  According to a ninth aspect of the present invention, there is provided a clamping device, a first working chamber for driving a piston member for clamping force output in a forward movement direction in which a piston rod is retracted by pressurized air, and the piston member by pressurized air. It has a second working chamber that drives in the reverse direction opposite to the forward direction, and an air supply passage connected to an external pressurized air supply source, and detects the operating state via the air pressure in this air supply passage In a possible clamping device, a fourth air passage that connects the air supply passage to the first working chamber, and a fourth on-off valve that is interposed in the fourth air passage and opens when the piston member reaches the return limit position And when the fourth on-off valve mechanism opens when the piston member reaches the return limit position, the detection pressurized air is discharged to the first working chamber through the fourth air passage. It is characterized by the construction.

According to the first aspect of the present invention, the first and second working chambers for driving the piston member to the clamping position and the unclamping position by pressurized air, respectively, and the air supply passage connected to the external pressurized air supply source And a first air passage connecting the air supply passage to the second working chamber, and a first air passage interposed between the first air passage and the first air passage. And a first on-off valve mechanism that opens when an operating state occurs. When the first operating state occurs in the clamp operating state and the first on-off valve mechanism opens, the detection pressurized air is supplied to the first air Since the second working chamber is discharged through the passage, the second working chamber that is open to the atmosphere in the clamp operation state can be effectively used to discharge the pressurized air for detection.
For this reason, at least a part of the exhaust passage for exhausting the pressurized air for detection can be omitted, so that compactness and a reduction in manufacturing costs can be achieved.

  According to the second aspect of the present invention, the second air passage connecting the air supply passage to the first working chamber, and the second on-off valve mechanism that is interposed in the second air passage and opens when the second operation state occurs. And when the second operating state occurs and the second on-off valve mechanism is opened in the unclamping operating state, the detection pressurized air is discharged to the first working chamber via the second air passage. Since it comprised, the pressurized air for a detection can be discharged | emitted effectively using the 1st working chamber open | released by air | atmosphere in an unclamp operation state. For this reason, at least a part of the exhaust passage for exhausting the pressurized air for detection can be omitted, so that compactness and a reduction in manufacturing costs can be achieved.

  According to the third aspect of the present invention, the grip member is pulled and driven in a state where the grip member is supported by the fluid pressure or the elastic force of the spring by the support mechanism, so that the grip member is expanded and the inner circumference of the hole of the workpiece is increased. The surface can be gripped and clamped.

  According to the invention of claim 4, since the support mechanism includes the support member that supports the lower end of the grip and the annular pressure receiving member that receives the pressurized air of the first working chamber and supports the support member, The grip member can be supported by effectively utilizing the pressurized air in the chamber.

  According to the invention of claim 5, it is possible to detect a clamping error at the start of the clamping operation. According to the invention of claim 6, it is possible to reliably detect that the unclamped state has been reached. According to the seventh aspect of the present invention, since the seating detection air passage that is continuous with the air supply passage and is provided in the seating surface is provided, the seating of the workpiece on the seating surface is reliably detected. be able to.

  According to the eighth aspect of the present invention, it is possible to reliably detect that the piston member has reached the forward limit position via the air pressure in the air supply passage. Moreover, since the detection pressurized air is exhausted through the second working chamber, at least a part of the exhaust passage for exhausting the detection pressurized air can be omitted. Can do.

  According to the ninth aspect of the present invention, it is possible to reliably detect that the piston member has reached the backward movement limit position via the air pressure in the air supply passage. In addition, since the detection pressurized air is exhausted through the first working chamber, it is possible to omit at least a part of the exhaust passage for exhausting the detection pressurized air, thereby reducing the size and manufacturing cost. Can do.

It is a top view of the clamp device concerning the example of the present invention. It is a longitudinal cross-sectional view (II-II sectional view taken on the line of FIG. 1) of a clamp apparatus (unclamped state). It is a longitudinal cross-sectional view of the lower part of a clamp apparatus. It is a perspective view of a clamp rod. It is a front view of the upper end part of a clamp device. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. It is an enlarged view of the A section of FIG. It is an enlarged view of the B section of FIG. It is an enlarged view of the D section of FIG. FIG. 3 is a view corresponding to FIG. 2 of the clamp device (clamped state). It is an enlarged view of the E section of FIG. It is an enlarged view of the F section of FIG. FIG. 3 is a view corresponding to FIG. 2 of the clamping device when a clamping error occurs. It is an enlarged view of the G section of FIG. FIG. 3 is a view corresponding to FIG. 2 of the clamping device when a clamping error occurs. 6 is a longitudinal sectional view of first and second on-off valve mechanisms according to Embodiment 2. FIG. 6 is a longitudinal sectional view of first and second on-off valve mechanisms according to Embodiment 2. FIG. 6 is a longitudinal sectional view of a first on-off valve mechanism according to Embodiment 3. FIG. 6 is a longitudinal sectional view of a first on-off valve mechanism according to Embodiment 3. FIG. 6 is a longitudinal sectional view of a first on-off valve mechanism according to Embodiment 3. FIG. FIG. 9 is a plan view of a clamp device according to a fourth embodiment. It is the XXII-XXII sectional view taken on the line of FIG. It is the XXIII-XXIII sectional view taken on the line of FIG. It is the XXIV-XXIV sectional view taken on the line of FIG. It is an enlarged view of the P section of FIG. FIG. 26 is a diagram corresponding to FIG. 25. It is an enlarged view of the Q section in FIG. FIG. 28 is a diagram corresponding to FIG. 27.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

  As shown in FIGS. 1 to 3, the clamping device C grips the inner peripheral surface of the hole H of the workpiece W extending through the clamping body 1 and the insertion hole 1 d at the upper end portion of the clamping body 1. A possible grip member 2, a vertically extending clamp rod 3 engaged with the grip member 2, a scraper 4, an air cylinder 5 (driving means) for driving the clamp rod 3 up and down, a support mechanism 6, and a seating A detection mechanism 7, a clamp failure detection mechanism 8, an unclamp detection mechanism 9, and the like are provided. The clamp body 1 includes an upper body 1a and a lower body 1b, and the clamp body 1 is assembled to the base member 1c.

The upper body 1a is substantially rectangular in plan view, and the upper body 1a is fixed to the base member 1c with four bolts inserted into the four bolt holes 1e.
The lower main body 1b is an annular member that forms a cylinder hole 11. The upper end portion of the lower main body 1b is fitted into the concave portion 12 on the lower end side of the upper main body 1a, and is fixed to the upper main body 1a by a plurality of bolts 13. . At the center of the upper half of the clamp main body 1, a cylindrical main body cylinder portion 1t that protrudes upward and downward is provided.

  The grip member 2 and the clamp rod 3 are disposed so as to vertically penetrate the insertion hole 1d at the center of the upper end portion of the main body cylinder portion 1t. Four arc-shaped seating surfaces 1s surrounding the grip member 2 are formed on the upper surface of the main body cylindrical portion 1t, and the workpiece W is clamped in a state where the workpiece W is seated on the seating surface 1s. On the upper surface of the main body cylinder portion 1t, four concave grooves 1g through which air blown pressurized air flows are formed in a cross shape.

Next, the grip member 2 will be described.
As shown in FIGS. 1 to 6, the grip member 2 is configured to be able to grip the inner peripheral surface of the hole H of the workpiece W extending through the insertion hole 1 d of the upper end portion of the clamp body 1 together with the clamp rod 3. Has been. The grip member 2 is composed of three steel grip forming members 2 a arranged at equal intervals on the outer peripheral side of the clamp rod 3. The three grip forming members 2a can be enlarged / reduced in outer diameter. A grip claw portion 2b is formed on the upper portion of the grip forming member 2a, and an arc-shaped base end collar portion 2c is formed on the lower end portion of the grip forming member 2a. A straight plane 2d parallel to the axis of the clamp rod 3 is formed on the inner surface of the lower half of the grip forming member 2a.

  A cross section (horizontal cross section) perpendicular to the axis of the clamp rod 3 of the grip claw portion 2b is formed in a flat D shape. On the inner surface from the upper end portion to the middle step portion of the grip forming member 2a, a taper surface 2e that is separated from the axis X of the clamp rod 3 is formed upward, and this taper surface 2e is a taper surface of the taper portion 3a of the clamp rod 3. 31 can be engaged in close contact. Three steps of teeth that grip the inner peripheral surface of the hole H of the workpiece W are formed on the outer peripheral surface of the grip claw portion 2b.

  As shown in FIGS. 1 and 2, a scraper 4 that closes the annular gap on the outer peripheral side of the grip member 2 and the clamp rod 3 is mounted in the insertion hole 1 d of the upper body 1 a. The scraper 4 is made of an elastic material such as rubber or synthetic resin that is in close contact with the outer peripheral surfaces of the grip member 2 and the clamp rod 3. The scraper 4 prevents chips and cutting fluid from entering the inside through the gaps on the outer peripheral side of the grip member 2 and the clamp rod 3, and prevents the pressurized air from leaking from the inside of the clamp body 1 to the outside. The grip forming member 2a and the clamp rod 3 are bundled. At the lower part of the grip member 2, an O-ring 14 for urging the three divided grip forming members 2a in the diameter reducing direction is mounted.

  The three base end flanges 2c of the three grip members 2 are accommodated in the circular recess 15 in the main body cylindrical part 1t, and a gap is formed on the outer peripheral side of the base end base 2c. The three base end flanges 2 c are movably sandwiched in the horizontal direction between the upper wall portion of the circular recess 15 and the upper end wall 40 b of the support member 40, and are supported by the support member 40. The grip member 2 moves up and down integrally with the support member 40 and the annular pressure receiving member 41, and at the same time, is perpendicular to the axial center of the clamping device C through the annular clearance of the outer periphery of the circular recess 15 and the elastic deformation of the scraper 4. It is mounted so that it can move in the direction. A cylindrical hole 19 is formed in the upper main body 1 a so as to continue below the circular recess 15.

Next, the clamp rod 3 will be described.
As shown in FIGS. 1 to 6, the clamp rod 3 is engaged with the inside of the grip member 2 and extends downward from the grip member 2. The clamp rod 3 includes an engagement portion 3d having a reverse T-shaped cross section at the lower end portion, a small diameter portion 3c having a circular horizontal cross section extending upward from the engagement portion 3d, and a middle step portion 3b continuing upward from the small diameter portion 3c. And a taper portion 3a extending upward from the middle step portion 3b. The taper portion 3a is formed so that the outer diameter increases toward the upper side, and the taper portion 3a includes three taper surfaces 31 for driving the grip forming member 2a to the outer diameter enlargement side.

  The middle step portion 3b has three straight surfaces 32 and a partial conical surface 36, and portions other than the straight surface 32 of the middle step portion 3b are formed in a partial conical shape whose outer diameter increases upward. The three straight surfaces 32 are formed in parallel with the axis of the clamp rod 3 so as to be continuous with the lower ends of the three tapered surfaces 31. The straight plane 2d of the grip forming member 2a is in surface contact with the straight surface 32.

The tapered portion 3a includes three tapered surfaces 31 with which the grip claws 2b of the three grip forming members 2a abut in surface contact, a partial conical surface 33 whose radius increases toward the upper side, and a partial cylindrical surface 34 that is short in the vertical direction. And a partial cylindrical surface 35 continuous with the partial conical surface 33.
The horizontal cross section at the lower part of the taper portion 3a is formed in a triangular shape having sides parallel to the taper surface 31 and the apex of an arc (see FIG. 6). In the vicinity of the scraper 4, the partial conical surface 33 that constitutes each of the triangular tops can contact the inner peripheral portion of the scraper 4.

  From the unclamped state to the clamped state, the horizontal section of the three grip forming members 2a and the clamp rod 3 (the horizontal section orthogonal to the axis X of the clamp rod 3) is formed in a circular shape in the vicinity of the scraper 4. Yes. The inclination angles of the tapered plane 31 and the partial conical surface 33 with respect to the axis of the clamp rod 3 are the same.

  In this clamping device C, when the clamp rod 3 is gradually moved downward from the unclamped state in which the grip member 2 and the clamp rod 3 are positioned at their upper limit positions, and the grip member 2 is driven to expand the diameter, the scraper 4 The outer diameters of the three grip-forming members 2a and the cylindrical portion of the clamp rod 3 in the vicinity of each of the clamp rods 3 gradually increase, and the inner peripheral portion of the scraper 4 is elastically deformed in the circumferential direction and the radial direction, so that the three grip-forming members 2a Is maintained in close contact with the outer peripheral surface of the clamp rod 3 (see FIG. 6).

Next, the double acting type air cylinder 5 will be described.
As shown in FIGS. 1 to 4, the air cylinder 5 drives the clamp rod 3 up and down with pressurized air relative to the clamp body 1 and the grip member 2. The air cylinder 5 includes a vertically oriented cylinder hole 11 formed in the lower main body 1b, a piston member 20 (having an axis X) for outputting a clamping force, and a clamping member above the piston portion 20a of the piston member 20. A first working chamber 21 for driving the piston member 20 to a clamping position with pressurized air, and a second working chamber 22 for unclamping on the lower side of the piston portion 20a. A second working chamber 22 for driving 20 to an unclamping position (upper limit position) by pressurized air is provided.

  The piston member 20 has a piston portion 20a that is mounted in the cylinder hole 11 so as to be airtightly slidable, and a rod portion 20b that extends upward from the piston portion 20a into the main body cylindrical portion 1t. The outer peripheral portion of the piston portion 20a is hermetically sealed with a seal member 23a, and the outer peripheral portion of the rod portion 20b is hermetically sealed with a seal member 23b. A screw shaft portion 24 is formed on the upper end side portion of the rod portion 20b, and a T groove forming member 26 for forming an inverted T-shaped T groove 25 is attached to the screw shaft portion 24 by screwing. .

  The rod insertion hole 26a of the T groove forming member 26 is U-shaped in a plan view, and the engaging portion 3d of the clamp rod 3 is attached to the T groove 25 from the lateral side. Since there is a slight gap between the engaging portion 3 d and the T groove forming member 26, the clamp rod 3 can move about 1 to 2 mm relative to the T groove forming member 26 in the horizontal direction.

The first working chamber 21 is formed by the lower main body 1b, the piston portion 20a, and the annular pressure receiving member 41. Pressurized air can be supplied to the first working chamber 21 from the external pressurized air supply source 16 through the air passage 45 and the air passage 17 in the clamp body 1, and is supplied to the first working chamber 21. The piston member 20 is driven to the clamp side (downward) by the pressurized air. The second working chamber 22 is formed by the lower main body 1b, the base member 1c, and the piston portion 20a. Pressurized air can be supplied to the second working chamber 22 from the pressurized air supply source 16 via the air passage 18, and the piston member 20 is unclamped by the pressurized air supplied to the second working chamber 22. Driven (upward).
A pressure switch 46 or a pressure sensor is connected to the air passage 45.

Next, the support mechanism 6 will be described.
As shown in FIG. 2, the support mechanism 6 is a mechanism that supports the grip member 2 from below, and the support mechanism 6 includes a support member 40 that supports the lower end of the grip member 2 and an annular pressure receiving pressure that supports the support member 40. A member 41 and a support working chamber 21 a for applying pressurized air to the lower end of the annular pressure receiving member 41 are provided.

  The support member 40 includes a cylindrical portion 40a that is movably mounted between the outer peripheral surface of the T groove forming member 26 and the wall surface of the cylindrical hole 19, and an upper end wall 40b that is integrally formed with the upper end of the cylindrical portion 40a. The clamp rod 3 is inserted through the opening 40c formed in the upper end wall 40b. The opening 40c is formed so that a portion other than the locking portion 3d of the clamp rod 3 can pass therethrough.

  The annular pressure receiving member 41 is slidably fitted on the rod portion 20 b of the piston member 20. The annular pressure receiving member 41 includes a lower half piston portion 41a and a cylindrical portion 41b that integrally extends upward from the upper end of the piston portion 41a. The cylindrical portion 41 b is movably mounted between the rod portion 20 b and the wall surface of the cylindrical hole 19. The lower end of the support member 40 is supported by the upper end of the cylindrical part 41b. The piston portion 41 a includes a valve operating flange portion 42 formed at an upper end portion thereof, a middle diameter portion 43 that is continuous with the lower end of the flange portion 42 and has a slightly smaller diameter than the flange portion 42, and a middle diameter portion 43. A slightly smaller-diameter piston body 44 is provided.

The flange portion 42 is accommodated in the accommodation hole 42a so as to be movable several millimeters (for example, 2 to 3 mm) in the vertical direction. When in the unclamped state, the annular portion having the thickness of several millimeters is formed below the flange portion 42. A gap 42b is formed.
The middle diameter portion 43 is accommodated in the accommodation hole 43a so as to be movable in the vertical direction. The piston main body 44 is accommodated in the accommodation hole 44 a, and the accommodation hole 44 a communicates with the support working chamber 21 a configured by a part of the first working chamber 21 for clamping. The piston main body 44 is configured to receive the pressurized air (the pressurized air in the support working chamber 21a).

  The outer peripheral portion of the intermediate diameter portion 43 is hermetically sealed with a seal member 43b, and an annular gap 43c slightly thicker than the annular gap 42b is formed below the intermediate diameter portion 43. The outer peripheral side of the piston main body 44 is sealed with a seal member 44b. The support mechanism 6 supports the grip member 2 with the pressure of the pressurized air acting on the annular pressure receiving member 41 when the grip member 2 is expanded to grip the inner peripheral surface of the hole H of the workpiece W, and the grip member 2, the clamp rod 3 can move relatively downward. In this embodiment, the support mechanism 6 that supports the grip member 2 via the support member 40 by applying the pressure of pressurized air to the annular pressure receiving member 41 has been described as an example. You may employ | adopt the support mechanism which supports the grip member 2 with the elastic force of.

Next, the seating detection mechanism 7 will be described.
As shown in FIGS. 1 and 2, the seating detection mechanism 7 is an air supply passage 50 formed in the upper body 1 a, and is a pressurized air from an external pressurized air supply source 16 through an air passage 47. Air supply passage 50, an open hole 51 formed at the downstream end of the air supply passage 50 and opened to the seating surface 1 s, and a pressure switch 48 or a pressure sensor connected to the air passage 47. . The air supply passage 50 includes an inclined passage 50a and a vertical passage 50b formed in the main body cylinder portion 1t, and an open hole 51 is formed at the downstream end of the vertical passage 50b. The vertical passage 50b corresponds to a seating detection air passage.

  When the workpiece W is in a clamped state in close contact with the seating surface 1s, the pressurized air does not leak from the opening hole 51, so that the air pressure in the air passage 47 becomes equal to or higher than the set value, and the pressure switch 48 is turned on. However, even in the clamped state, when the workpiece W is not in close contact with the seating surface 1s, the pressure switch 48 is turned OFF because the pressurized air leaks from the opening hole 51. Thus, it is detected whether or not the workpiece W is seated on the seating surface 1s when the workpiece W is in the clamped state.

Next, the air blow mechanism 52 will be described.
The air blow mechanism 52 supplies pressurized air into the clamp body 1 and ejects it from a small gap between the clamp rod 3, the grip member 2 and the scraper 4 to prevent intrusion of chips and cutting fluid. is there. As shown in FIGS. 1 to 3, the air blow mechanism 52 is an inclined passage 52 a similar to the inclined passage 50 a of the seating detection mechanism 7, and is an inclined passage through which pressurized air is supplied from the external pressurized air supply source 16. 52a, and an air passage (not shown) for communicating the downstream end of the inclined passage 52a with the cutout hole 52b at the lower end of the cylindrical portion 40a of the support member 40. Thus, the pressurized air is supplied to the grip member 2 and the clamp rod 3 through the cylindrical gap between the inner surface side and the outer surface side of the cylindrical portion 40 a of the support member 40.

Next, the clamp error detection mechanism 8 will be described.
The clamping error detection mechanism 8 is a clamping error that occurs when the grip claw portion 2b of the grip member 2 slips with respect to the inner peripheral surface of the hole H of the workpiece W at the start of the clamping operation. This is a mechanism for detecting a clamping error (corresponding to the first operating state) such as a clamping error that occurs because C is larger than an applicable set size and a clamping error that occurs due to breakage of the grip claw portion 2b.

  As shown in FIGS. 2 and 7, the clamping error detection mechanism 8 is interposed between the first air passage 54 and the first air passage 54 that connect the inclined passage 50 a of the air supply passage 50 to the second working chamber 22. A first on-off valve mechanism 55 that opens when a clamping error occurs, and the first on-off valve mechanism 55 is opened due to a clamping error in the clamp operating state in which pressurized air is supplied to the first working chamber 21. At this time, the detection pressurized air is configured to be discharged to the second working chamber 22 via the first air passage 54.

  The first air passage 54 includes an air passage 54a, an air passage 54b formed inside the valve body 57 of the first on-off valve mechanism 55, an annular gap 54m, air passages 54c to 54g, and the like. The air passage 54a communicates with the inclined passage 50a. In a state where the first on-off valve mechanism 55 is opened, the air passage 54a communicates with the air passage 54b. The air passage 54b communicates with the annular clearance 43c via the annular clearance 54m and the air passage 54c, and the annular clearance 43c communicates with the air passage 54e on the outer peripheral side of the rod portion 20b via the air passage 54d. The air passage 54g communicates with the air passage 54g formed in the lower portion of the rod portion 20b via the air passage 54f, and the air passage 54g communicates with the second working chamber 22. The lower end portion of the air passage 54g is formed in a hexagonal hole.

As shown in FIGS. 2, 7, and 8, the first on-off valve mechanism 55 includes an accommodation hole 56 formed in the clamp body 1 and a valve body 57 that is movably mounted in the accommodation hole 56. Yes.
The accommodation hole 56 includes an upper accommodation hole 56a, an intermediate accommodation hole 56b having a diameter larger than that of the upper accommodation hole 56a, and a lower accommodation hole 56c having the same diameter as the upper accommodation hole 56a. An upper end of the upper accommodation hole 56 a communicates with the inclined passage 50 a through the air passage 54 a, and a lower end portion of the lower accommodation hole 56 c communicates with the first working chamber 21 through the communication path 58. The valve body 57 can be raised and lowered by the thickness of the annular gap 54m.

The valve body 57 includes a valve body upper part 57a that is movably accommodated in the upper accommodation hole 56a, and a valve body intermediate part 57b that is movably accommodated by several mm (for example, 2 to 3 mm) in the vertical direction in the intermediate accommodation hole 56b. The valve body lower part 57c movably accommodated in the lower accommodation hole 56c is integrally formed.
The outer peripheral portions of the valve body upper portion 57a, the valve body intermediate portion 57b, and the valve body lower portion 57c are sealed by seal members 59a, 59b, and 59c, respectively.

  A part on the axis X side of the outer peripheral part of the upper end part of the intermediate accommodation hole 56b overlaps with a part of the lower end part of the accommodation hole 42a, and the valve body 57 is positioned at the upper limit position. In the closed state where 57b is in contact with the upper wall surface of the intermediate housing hole 56b and the annular convex portion 56v (valve portion) is in close contact with the upper wall surface of the upper housing hole 56a, a part of the upper end of the valve body intermediate portion 57b is housed. It is in the state which protruded in a part of lower end part (lower end part of the annular clearance 42b) of the hole 42a.

2 and 7 show an unclamping operation state in which pressurized air is supplied to the second working chamber 22 and the first working chamber 21 is opened to the atmosphere.
As shown in FIGS. 10 and 11, in a clamped state where pressurized air is supplied to the first working chamber 21 and the second working chamber 22 is opened to the atmosphere, the lower housing is accommodated from the first working chamber 21 via the communication path 58. Pressurized air is supplied to the lower end portion of the hole 56c, the valve body 57 receives the pressure of the pressurized air and is positioned at the upper limit position, and the annular convex portion 56v (valve portion) at the upper end of the valve body 57 is the upper accommodation hole. The valve 56 is kept in close contact with the upper wall surface of 56a, and the air passages 54a and 54b are cut off. Therefore, the pressurized air in the air supply passage 50 does not leak to the second working chamber 22 through the first air passage 54, and the pressure of the pressurized air in the air supply passage 50 does not decrease.

  However, as shown in FIGS. 13 to 15, when the clamping pressure is generated at the start of the clamping operation, the annular pressure receiving member 41 moves to the lower limit position, and the flange portion 42 of the annular pressure receiving member 41 pushes down the valve body intermediate portion 57 b. Since the annular convex portion 56v is opened from the upper wall surface of the upper receiving hole 56a and the air passages 54a and 54b are in communication, the inclined passage 50a of the air supply passage 50 is secondly formed by the first air passage 54. The air is connected to the working chamber 22, and the detection pressurized air in the air supply passage 50 is discharged to the second working chamber 22 through the first air passage 54. As a result, the pressure of the pressurized air in the air supply passage 50 is reduced, and the pressure drop is detected by the pressure switch 48, so that the occurrence of a clamping error can be known. In the clamp operation state, since the second working chamber 22 is opened to the atmosphere via the air passage 18, the above-described detection pressurized air can be discharged.

Next, the unclamp detection mechanism 9 will be described.
The unclamp detection mechanism 9 detects that the clamp device C is in an unclamp operation state (corresponding to a second operation state). As shown in FIGS. 2, 9, and 10, the unclamp detection mechanism 9 is interposed in the second air passage 60 that connects the air supply passage 50 to the first working chamber 21 and the second air passage 60. And a second on-off valve mechanism 61 that opens when the unclamping state is achieved.

The second air passage 60 has an upstream end connected to the inclined passage 50a of the air supply passage 50 and is formed in the upper body 1a, and is connected to a downstream end of the air passage 60a and in the lower body 1b. The air passage 60b is formed in the air passage 60b.
The second on-off valve mechanism 61 includes an accommodation hole 62 formed in the lower main body 1 b, a valve body 63 and a plug member 64 accommodated in the accommodation hole 62, and a compression mounted between the valve body 63 and the plug member 64. A spring 65 and the like are provided.

  The accommodation hole 62 includes a cylindrical main accommodation hole 62a and a small-diameter accommodation hole 62b communicating with the lower end portion of the main accommodation hole 62a. The downstream end of the air passage 60b is the lower end portion of the main accommodation hole 62a. It is connected to the. The outer peripheral portions of the valve body 63 and the plug member 64 are sealed by seal members 66 and 67, respectively, and a compression spring 65 is attached to an internal space 63 i formed by the recess of the valve body 63 and the recess of the plug member 64, and the valve body 63 is compressed. The spring 65 is biased toward the valve closing side. The valve body 63 includes a projecting portion 63a inserted into the small-diameter receiving hole 62b with an annular gap, and an annular convex portion 63v (valve portion) formed so as to project downward on the annular lower surface of the valve body 63. I have.

  The protrusion 63a is formed with an introduction passage 68 for introducing pressurized air in the first working chamber 21 into the internal space 63i. In the clamped state where the first working chamber 21 is filled with pressurized air, the valve Since the body 63 is urged downward by the pressure of the pressurized air acting on the upper surface thereof, the annular convex portion 63v is brought into close contact with the lower end wall surface of the main housing hole 62a, and the air passage 60b is first actuated. It is separated from the chamber 21 (see FIGS. 10 and 12). In the closed state, the lower end of the protrusion 63a protrudes into the first working chamber 21.

  In the unclamped state in which the pressurized air in the first working chamber 21 is evacuated and the pressurized air is filled in the second working chamber 22, the piston member 20 moves to the upper limit position, and the upper end of the piston portion 20a is the first working chamber. Approach the top of 21. Therefore, as shown in FIG. 9, the piston portion 20a pushes the protruding portion 63a upward, the valve body 63 moves upward, and the annular convex portion 63v is separated from the lower end wall surface of the main accommodation hole 62a and is opened. Become. Then, the second air passage 60 communicates with the first working chamber 21, and the detection pressurized air in the air supply passage 50 is discharged to the first working chamber 21 through the second air passage 60.

  As a result, the pressure of the pressurized air in the air supply passage 50 is reduced, and the pressure drop is detected by the pressure switch 48, so that it can be known that the unclamped state has been switched. In the unclamping operation state, since the first working chamber 21 is opened to the atmosphere via the air passages 17 and 45, the detection pressurized air can be discharged.

Next, the operation and effect of the clamping device C described above will be supplementarily described.
First, in the unclamping operation state in which the pressurized air in the first working chamber 21 is evacuated and the pressurized air is supplied to the second working chamber 22, the workpiece W is loaded and the grip member 2 and the clamp rod are inserted into the hole H of the workpiece W. 3 is inserted and the work W is seated on the seating surface 1s.

  Next, when the pressurized air in the second working chamber 22 is removed and the pressurized air is supplied to the first working chamber 21 for clamping, the clamp rod 3 is gripped with the grip member 2 supported by the support mechanism 6. The grip member 2 is driven to move downward relative to the member 2, the diameter of the grip member 2 is increased, the inner peripheral surface of the hole H is gripped by the three grip claws 2 b, and the workpiece W is attracted to the seating surface 1 s to be in a clamped state. .

  When the clamping device C enters the clamping state shown in FIG. 10 without causing a clamping mistake, the pressurized air does not leak from the opening hole 51 of the seating surface 1s of the air supply passage 50, and the annular pressure receiving member 41 is lowered by a small distance. As a result, the annular gap 42b on the lower side of the flange portion 42 remains, so that the first on-off valve mechanism 55 maintains the closed state (see FIG. 11). For this reason, the pressure of the pressurized air in the air supply passage 50 becomes equal to or higher than the set value, and the pressure switch is turned on. In the state where pressurized air is supplied to the first working chamber 21, the valve body 63 of the second on-off valve mechanism 61 of the unclamp detection mechanism 9 is closed by the urging force of the compression spring 65 and the pressurized air. Is maintained (see FIG. 12).

  When a clamping error occurs at the start of the clamping operation and the clamping device C enters the state shown in FIG. 13 or FIG. 15, the flange portion 42 is lowered to the lower limit position, and the valve body 57 is pushed downward to Since the 1 on-off valve mechanism 55 is opened, the pressurized air in the inclined passage 50 a of the air supply passage 50 is discharged to the second working chamber 22 through the first air passage 54. As a result, the pressure of the pressurized air in the air supply passage 50 is maintained at a value lower than the set value, and the pressure switch is not turned on, so that the occurrence of a clamping error can be detected.

  Here, FIG. 13 shows a state in which a clamping error occurs in which the grip claw portion 2b slips with respect to the inner peripheral surface of the hole H of the workpiece W, and FIG. 15 shows that the size of the hole H of the workpiece W is too large. A state where a clamping mistake that cannot be gripped or a clamping mistake that cannot be gripped due to breakage of the grip claw portion 2b has occurred is shown. In the state where pressurized air is supplied to the first working chamber 21, the valve body 63 of the second on-off valve mechanism 61 of the unclamp detection mechanism 9 is closed by the urging force of the compression spring 65 and the pressurized air. To maintain.

  Next, when switching from the clamped state to the unclamped state, when the pressurized air in the first working chamber 21 is extracted and the pressurized air is supplied to the second working chamber 22, the piston member 20 is moved to the upper limit as shown in FIG. As shown in FIG. 9, the piston portion 20 a pushes up the protruding portion 63 a of the valve body 63 of the second opening / closing valve mechanism 61, so that the second opening / closing valve mechanism 61 is opened. Then, the pressurized air in the inclined passage 50 a of the air supply passage 50 is discharged to the first working chamber 21 through the second air passage 60. As a result, the pressure of the pressurized air in the air supply passage 50 drops below the set value, and the pressure switch is switched from ON to OFF, so that it can be detected that the clamp state has been switched to the unclamp state. In the unclamped state, the annular pressure receiving member 41 maintains the upper limit position, so the first on-off valve mechanism 55 maintains the valve closed state.

  The clamping error detection mechanism 8 is configured to discharge the pressurized air for detection of the air supply passage 50 from the first air passage 54 to the second working chamber 22 when a clamping mistake occurs, so that the detection pressurized air is clamped. C can be reliably discharged out of C, which is advantageous for simplifying the structure of the air passage, miniaturizing the clamp device C, and reducing manufacturing costs.

  The unclamp detection mechanism 9 is configured to discharge the detection pressurized air in the air supply passage 50 from the second air passage 60 to the first working chamber 21 when switching to the unclamped state. Can be reliably discharged out of the clamp device C, which is advantageous in simplifying the structure of the air passage, reducing the size of the clamp device C, and reducing manufacturing costs.

An example in which the second on-off valve mechanism 61A of the unclamp detection mechanism 9A is provided at a position near the lower side of the first on-off valve mechanism 55 of the clamp error detection mechanism 8 will be described. Components having the same structure as those of the first embodiment are denoted by the same reference numerals, description thereof is omitted, and only different configurations will be described.
As shown in FIGS. 16 and 17, the first on-off valve mechanism 55 is the same as the first on-off valve mechanism 55 of the first embodiment. The second on-off valve mechanism 61A includes an accommodation hole 62A that is continuous with the lower end of the lower accommodation hole 56c of the accommodation hole 56 of the first on-off valve mechanism 55, a valve body 63 that is movably mounted in the accommodation hole 62A, and a valve body 57. And a compression spring 65 </ b> A mounted between the valve body 63.

  The accommodation hole 62 </ b> A includes a main accommodation hole 62 a and a small-diameter accommodation hole 62 b that communicates with the lower end of the main accommodation hole 62 a and communicates with the first working chamber 21. The structure of the valve body 63, the main accommodation hole 62a, and the small diameter accommodation hole 62b is the same as that of the second on-off valve mechanism 61 of the first embodiment. The second air passage 60A branches from the inclined passage 50a of the air supply passage 50 and extends downward, and communicates with the lower end of the main accommodation hole 62a.

  As shown in FIG. 16, in the unclamped state, the piston portion 20a of the piston member 20 pushes up the protruding portion 63a of the valve body 63, so that the second on-off valve mechanism 61A is opened. As shown in FIG. 17, when in the clamped state, the second on-off valve mechanism 61 </ b> A is closed like the second on-off valve mechanism 61 of the first embodiment. Since the second on-off valve mechanism 61A is disposed in the vicinity of the first on-off valve mechanism 55, the structure of the second air passage 60A can be simplified and the manufacturing cost can be reduced.

The 1st on-off valve mechanism 70 which changed the 1st on-off valve mechanism 55 of the clamp mistake detection mechanism 8 is demonstrated. As shown in FIGS. 18-20, the 1st on-off valve mechanism 70 is the accommodation hole 71 formed in the clamp main body 1, the upper valve body 72 accommodated movably by the upper half part of this accommodation hole 71, A lower valve body 73 movably housed in the lower half of the housing hole 71 is provided.
The accommodation hole 71 is composed of an upper accommodation hole 71a having an upper portion of about 1/3 and a lower accommodation hole 71b having a larger diameter than the upper accommodation hole 71a.

  The upper valve body 72 has a valve body upper part 72a accommodated in the upper accommodation hole 71a, and a valve body lower part 72b that is connected downward from the lower end of the valve body upper part 72a and accommodated in the lower accommodation hole 71b. The lower valve body 73 is accommodated in the lower accommodation hole 71b. The outer peripheries of the upper valve body 72 and the lower valve body 73 are sealed with seal members 74a to 74c, respectively. The first air passage 54A includes an air passage 75a, an air passage 75b in the upper valve body 72, an air passage 75c between the upper valve body 72 and the lower valve body 73, and air on the outer peripheral side of the upper half of the lower valve body 73. The passage 75d includes an air passage 75e that connects the air passage 75d to the annular gap 43c, an air passage similar to the air passages 54d to 54g of the first embodiment, and the like.

  An annular convex portion 72v (valve portion) is formed at the upper end of the upper valve body 72. When the annular convex portion 72v is in contact with the upper wall surface of the receiving hole 71, the valve is closed, and the air passages 75a and 75b are divided. The A part of the valve body lower part 72b protrudes into the annular gap 42b, and when the flange part 42 descends to the lower limit position and pushes the valve body lower part 72b downward, like the first on-off valve mechanism 55 of the first embodiment. The upper valve body 72 moves downward, the annular convex portion 72v is separated from the upper wall surface of the accommodation hole 71 and is opened, and the air passages 75a and 75b communicate with each other. A communication hole 76 is formed in the lower end wall of the accommodation hole 71. Pressurized air in the first working chamber 21 acts in the lower end portion of the accommodation hole 71 through the communication hole 76, and the lower valve body 73 is added. The upper valve body 72 is biased upward by being biased upward by the pressure of the pressurized air.

  FIG. 18 shows an unclamped state in which the piston member 20 and its piston portion 20a are at the upper limit position, and the first on-off valve mechanism 70 is in a closed state. FIG. 19 shows a clamped state in which pressurized air is supplied to the first working chamber 21. Since the flange portion 42 is located above the lower limit position, the first on-off valve mechanism 70 is closed. FIG. 20 shows a state at the time of occurrence of a clamping error, and the flange portion 42 is in the lower limit position, and the upper valve body 72 is pushed down to open the valve. In the first on-off valve mechanism 70, the structure of the accommodation hole 71 and the valve body 72 is simplified, and the structure of the air passage in the valve body 72 is simplified.

As shown in FIGS. 21 to 23, the clamp device CA according to this embodiment has a basic structure of a clamp body 80, a piston member 81 for outputting a clamping force, and a piston member 81 formed in the clamp body 80. The piston portion 81a is slidably mounted in a cylinder hole 80a.
The clamp body 80 includes a main clamp body 82 that forms a cylinder hole 80a and an end wall member 83 that closes the lower end of the cylinder hole 80a. The end wall member 83 is fitted into the fitting hole 83a at the lower end portion of the main clamp body 82, is prevented from coming off by a retaining ring 83b, and its outer peripheral portion is sealed by a sealing member 83c.

  The main clamp main body 82 has a flange portion 82a at the upper end side portion and a cylinder hole forming portion 82b extending downward from the flange portion 82a. When installing the clamp device CA, the cylinder hole forming portion 82b and the end wall member 83 are inserted into the vertical mounting hole 84a of the base 84, and the lower surface of the flange portion 82a is brought into contact with the upper surface of the base 84. Then, a plurality of bolts (not shown) passed through the plurality of bolt holes 85 of the flange portion 82 a are screwed into the base 84.

  The piston member 81 includes a piston portion 81a and a piston rod 81b extending upward from the piston portion 81a through an insertion hole 86 in the upper center of the main clamp body 82 so as to be airtightly slidable. The outer peripheral portion of the piston portion 81a is sealed with a seal member 87, the outer peripheral side of the piston rod 81b is sealed with a seal member 88 attached to the inner peripheral wall portion of the insertion hole 86, and the inner peripheral wall portion near the upper end of the insertion hole 86 is A dust seal 89 is attached.

  A clamp member (not shown) for pressing the workpiece is connected to the upper end of the piston rod 81b of the clamp device CA. The clamp device CA is configured to drive the piston rod 81b in the forward direction (downward) during clamping, but may be configured to drive the piston rod 81b in the backward direction during clamping.

  A first working chamber 91 (forward operation chamber) is formed above the piston portion 81a in the cylinder hole 80a to drive the piston member 81 in the forward direction in which the piston rod 81b is retracted by pressurized air. A second working chamber 92 (returning operation chamber) is formed below the piston portion 81a in the cylinder hole 80a to drive the piston member 81 in the backward movement direction opposite to the forward movement direction with pressurized air.

  As shown in FIG. 22, an air supply port 93 that supplies pressurized air is formed in the flange portion 82 a, and the air supply port 93 communicates with the first working chamber 91 via air passages 94 and 95. . In this embodiment, the side surface of the air supply port 93 is sealed with a plug member 96, an auxiliary air supply port 93 a connected to the air supply port 93 is formed downward, and from the pressurized air supply source 97, an external air passage 98, Pressurized air is supplied to the auxiliary air supply port 93 a and the air supply port 93 through an air passage 99 formed in the base 84.

  As shown in FIG. 23, an air supply port 100 for supplying pressurized air is formed in the flange portion 82a, and the air supply port 100 communicates with the second working chamber 92 via air passages 102 and 103. . In the present embodiment, the side surface of the air supply port 100 is sealed by the plug member 104, the auxiliary air supply port 100a connected to the air supply port 100 is formed downward, and from the pressurized air supply source 97, the external air passage 105, Pressurized air is supplied to the auxiliary air supply port 100 a and the air supply port 100 through the air passage 106 formed in the base 84.

Next, a configuration unique to the present application will be described with reference to FIGS.
First, the third on-off valve mechanism 110 for detecting that the piston member 81 has reached the forward movement limit position and the air passage related thereto will be described with reference to FIGS.
A valve case 111 is screwed to the center portion of the end wall member 83, and an air supply passage 112 connected to an external pressurized air supply source 97 and an air supply passage 112 are connected to the valve case 111. A third air passage 113 that connects to the second working chamber 92, and a third on-off valve mechanism 110 that is interposed in the third air passage 113 and opens when the piston member 81 reaches the forward movement limit position. It has been.

  When the piston member 81 reaches the forward limit position and the third on-off valve mechanism 110 opens, the detection pressurized air is discharged to the second working chamber 92 via the third air passage 113. It is. The air supply passage 112 is connected to a pressurized air supply source 97 via an air passage 115 formed in the base 84 and an external air passage 116, and a pressure switch 117 or a pressure sensor is connected to the external air passage 116. The operation state in which the piston member 81 has reached the forward limit position can be detected via the air pressure in the air supply passage 112.

As shown in FIGS. 24 to 26, the valve case 111 is mounted in a mounting hole 118 formed in the end wall member 83. The mounting hole 118 includes a screw hole 118a and a large diameter hole 118b in the lower half, a small diameter hole 118c, and a through hole 118d formed in the partition wall 107. A partition wall 107 that partitions the second working chamber 92 and the mounting hole 118 is formed on the upper end side of the small diameter hole 118c. The air supply passage 112 is formed in the lower half of the valve case 111.
The third air passage 113 includes an inclined air passage 113a in the middle of the valve case 111, an air passage 113b formed on the outer peripheral side and upper side of the upper half of the valve case 111 in the small diameter hole 118c, and a through hole 118d. And a passage hole 113c (which communicates with the second working chamber 92) on the outer peripheral side of the protrusion 120b of the valve body 120.

  The third on-off valve mechanism 110 includes a housing hole 119 formed in the valve case 111, a valve body 120 slidably mounted in a large diameter hole 119a of the housing hole 119, and an interior for introducing pressurized air. A space 121 and a compression spring 122 are provided.

  The accommodation hole 119 has a large diameter hole 119a and a small diameter hole 119b. The valve body 120 includes a large-diameter portion 120a that is slidably mounted in the large-diameter hole 119a, and a protruding portion 120b that protrudes from the central portion of the upper end of the large-diameter portion 120a and penetrates the through-hole 118d. The outer peripheral portion of the large diameter portion 120a is sealed with a seal member a. The internal space 121 is composed of a recess 120c of the large diameter portion 120a, a lower end portion of the large diameter hole 119a, and a small diameter hole 119b, and a compression spring 122 for urging the valve body 120 upward is attached to the internal space 121. Has been.

  At the upper end of the large diameter portion 120a of the valve body 120, an annular convex portion 120v (valve portion) located on the outer peripheral side from the protruding portion 120b is formed, and when this annular convex portion 120v is in close contact with the lower surface of the partition wall portion 107, When the annular air projecting portion 120v is separated from the lower surface of the partition wall 107, the third air passage 113 is fully opened. The projecting portion 120b is formed with a communication passage 123 for introducing the pressurized air of the second working chamber 92 into the internal space 121, and is normally urged by the pressure of the pressurized air and the elastic force of the compression spring 22. The body 120 is closed at the upper limit position, and the tip of the protruding portion 120b protrudes, for example, by 2 to 3 mm above the upper surface of the partition wall portion 107 (see FIG. 25). However, when the piston member 81 is lowered to the forward movement limit position, the lower surface of the piston portion 81a pushes the tip of the protruding portion 120b downward, so that the valve is opened (see FIG. 26).

  When the second working chamber 92 is open to the atmosphere (when pressurized air is being discharged), when the third on-off valve mechanism 110 is in the open state, the air pressure in the air supply passage 112 drops below the set value, and the pressure switch 117 is Since switching from ON to OFF, it is possible to detect that the piston member 81 has reached the forward movement limit position. When the piston member 81 moves forward, the second working chamber 92 is opened to the atmosphere via the air passages 102 and 103, the air supply port 100, and the air passage 106, so that the second working chamber 92 is effectively utilized. The pressurized air for detection can be discharged. Since at least a part of the exhaust passage for discharging the detection pressurized air can be omitted, it is possible to reduce the size and the manufacturing cost.

Next, the fourth on-off valve mechanism 130 for detecting that the piston member 81 has reached the backward movement limit position and the air passage related thereto will be described with reference to FIGS. 24, 27, and 28. FIG.
A valve case 131 is mounted on the flange portion 82a. An air supply passage 132 connected to an external pressurized air supply source 97 is connected to the flange portion 82a, and a first air passage 132 connecting the air supply passage 132 to the first working chamber 91 is provided. There are provided a fourth air passage 136 and a fourth on-off valve mechanism 130 that is interposed in the fourth air passage 136 and opens when the piston member 81 reaches the return limit position.

  When the piston member 81 reaches the return limit position and the fourth on-off valve mechanism 130 opens, the detection pressurized air is discharged to the first working chamber 91 via the fourth air passage 136. It is. The air supply passage 132 is connected to a pressurized air supply source 97 via an air passage 133 formed in the base 84 and an external air passage 134, and a pressure switch 135 or a pressure sensor is connected to the external air passage 134. The operating state in which the piston member 81 has reached the return limit position can be detected via the air pressure in the air supply passage 132.

  As shown in FIGS. 24, 27, and 28, the valve case 131 is mounted in a vertical mounting hole 137 formed in the flange portion 82 a and is prevented from coming off by a retaining ring 138. The mounting hole 137 has a cylindrical hole 137a that is long in the vertical direction, and a through hole 137b formed in the partition wall 108 on the lower end side of the cylindrical hole 137a. A lower end side portion of the valve case 131 is formed to have a smaller diameter than the cylindrical hole 137a, and an air passage 136a is formed on the outer peripheral side and the lower side of the lower end side portion of the valve case 131.

  The air supply passage 132 is formed horizontally near the lower end of the flange portion 82a and communicates with the air passage 136a. The fourth air passage 136 includes the air passage 136a and an annular passage hole 136b on the outer peripheral side portion of the through hole 137b formed in the partition wall 108.

  The fourth on-off valve mechanism 130 includes a housing hole 138 formed in the valve case 131, a valve body 139 slidably mounted in a large-diameter hole 138a of the housing hole 138, and an interior for introducing pressurized air. A space 140 and a compression spring 141 are provided.

  The accommodation hole 138 has a large diameter hole 138a and a small diameter hole 138b. The valve body 139 includes a large-diameter portion 139a that is air-tightly slidably mounted in the large-diameter hole 138a, and a projecting portion 139b that projects from the central portion of the lower end of the large-diameter portion 139a and penetrates the through-hole 137b. The outer peripheral portion of the large diameter portion 139a is sealed with a seal member 139c. An internal space 140 is formed by the concave portion 140a of the large diameter portion 139a, the upper end portion of the large diameter hole 138a, and the small diameter hole 138b, and a compression spring 141 for urging the valve body 139 downward is mounted in the internal space 140. .

  At the lower end of the large diameter portion 139a of the valve body 139, an annular convex portion 139v (valve portion) located on the outer peripheral side from the protruding portion 139b is formed, and when this annular convex portion 139v is in close contact with the upper surface of the partition wall portion 108, When the fourth air passage 136 is separated and the annular convex portion 139v is separated from the upper surface of the partition wall portion 108, the fourth air passage 136 is fully opened. The projecting portion 139b is formed with a communication passage 142 for introducing the pressurized air of the first working chamber 91 into the internal space 140. Normally, the valve body 139 is located at its lower limit position and is closed, and the projecting portion 139b. For example, protrudes 2 to 3 mm below the lower surface of the partition wall 108 (see FIG. 28). However, when the piston member 81 rises to the return limit position, the upper surface of the piston portion 81a pushes the tip of the protruding portion 139b upward, so that the valve is opened (see FIG. 27).

  When the fourth on-off valve mechanism 130 is opened, the air pressure in the air supply passage 132 decreases below the set value, and the pressure switch 135 is switched from ON to OFF, so that the piston member 81 reaches the return limit position. Can be detected. When the piston member 81 moves backward, the first working chamber 91 is opened to the atmosphere via the air passage 136, the air supply passage 132, and the air passages 133, 134. The pressurized air for detection can be discharged. Since at least a part of the exhaust passage for discharging the detection pressurized air can be omitted, it is possible to reduce the size and the manufacturing cost.

Next, an example in which the above embodiment is partially changed will be described.
(1) The clamp body 1 may have a structure that does not include the body tube portion 1t.
(2) The support mechanism 6 has been described as an example of the structure in which the annular pressure receiving member 41 receives the pressurized air in the first working chamber 21, but the pressurized air supplied to the working chamber independent of the first working chamber 21. Alternatively, the annular pressure receiving member 41 may receive the pressure.
(3) As the support mechanism 6, support mechanisms having various structures in which the grip member is supported by a spring member such as a disc spring or a coil spring can be employed.

(4) The valve mechanism is closed only by the urging mechanism using the pressure receiving area difference of the pressure receiving part that receives the pressurized air, the urging mechanism using the pressure difference of the pressurized air, and the elastic force of the spring member. Various urging mechanisms such as an urging mechanism can be employed.

  The present invention provides a technique that can be applied to various types of clamping devices incorporating a mechanism for detecting an operating state via air pressure, and that can make the clamping device compact and reduce manufacturing costs.

W Work H Hole C Clamp device 1 Clamp body 1 s Seating surface 2 Grip member 3 Clamp rod 4 Scraper 6 Support mechanism 8 Clamp error detection mechanism 9 Unclamp detection mechanism 16 Pressurized air supply source 20 Piston member 21 First working chamber 22 First 2 working chamber 40 support member 41 annular pressure receiving member 42 flange portion 48 pressure switch 50 air supply passage 50a inclined passage 50b vertical passage 51 opening hole 54, 54A first air passage 55, 70 first on-off valve mechanism 56v annular convex portion 60, 60A Second air passage 61, 61A Second on-off valve mechanism 60a, 60b Air passage 63v Annular convex part CA Clamp device 72v Annular convex part 80 Clamp body 81 Piston member 81a Piston part 81b Piston rods 91, 92 First and second operations Chamber 97 Pressurized air supply source 110 Third on-off valve mechanism 1 2,132 air supply passage 113 third air passage 117,135 pressure switch 120v, 139v annular protrusion 130 fourth on-off valve mechanism 136 fourth air passage

Claims (9)

A clamp body, a first working chamber for driving a clamping force output piston member to a clamping position by pressurized air, a second working chamber for driving the piston member to an unclamping position by pressurized air, and the inside of the clamping body And a clamp device capable of detecting an operating state via the air pressure of the air supply passage, and an air supply passage connected to an external pressurized air supply source.
A first air passage connecting the air supply passage to a second working chamber;
A first on-off valve mechanism that is interposed in the first air passage and opens when the first operating state occurs,
When the first operating state occurs in the clamp operating state in which pressurized air is supplied to the first working chamber and the first on-off valve mechanism is opened, the detection pressurized air is supplied to the second through the first air passage. A clamping device characterized in that it is configured to be discharged into the working chamber. A second air passage connecting the air supply passage to the first working chamber;
A second on-off valve mechanism that is interposed in the second air passage and opens when the second operating state occurs,
In the unclamping operation state in which the pressurized air is supplied to the second working chamber, when the second operation state occurs and the second on-off valve mechanism opens, the detection pressurized air is supplied via the second air passage. The clamp device according to claim 1, wherein the clamp device is configured to discharge into one working chamber.   A grip member that extends upward through the insertion hole in the upper end portion of the clamp body and can grip the inner peripheral surface of the hole of the work, a clamp rod engaged with the grip member, The clamp device according to claim 1, further comprising a support mechanism that is supported by an elastic force.   The clamp according to claim 3, wherein the support mechanism includes a support member that supports a lower end of the grip member and an annular pressure receiving member that receives the pressurized air of the first working chamber and supports the support member. apparatus.   The first operating state is a state in which the grip member slips with respect to the workpiece when the clamping operation is started and the annular pressure receiving member is lowered to the lower limit position. When the first operating state occurs, the annular pressure receiving member is moved to the first on-off valve mechanism. The clamp device according to claim 3, which is configured to open the valve.   The second operating state is a state in which the piston member is in an unclamped state, and the piston portion of the piston member opens the second on-off valve mechanism when the second operating state occurs. The clamping device according to claim 3.   A seating detection air passage formed in the clamp body and connected to the air supply passage, wherein a seating detection air passage is provided that is open to a seating surface on which a workpiece at the upper end of the clamp body is seated. The clamping device according to claim 6. A clamp body, a first working chamber for driving a piston member for clamping force output in a forward movement direction in which a piston rod is retracted by pressurized air, and a backward movement of the piston member opposite to the forward movement direction by pressurized air A clamp device that includes a second working chamber that is driven in a direction and an air supply passage that is connected to an external pressurized air supply source, and is capable of detecting an operating state via the air pressure of the air supply passage;
A third air passage connecting the air supply passage to the second working chamber;
A third on-off valve mechanism that is interposed in the third air passage and opens when the piston member reaches the forward movement limit position;
When the piston member reaches the forward movement limit position and the third on-off valve mechanism opens, the detection pressurized air is discharged to the second working chamber through the third air passage. And clamping device. A clamp body, a first working chamber for driving a piston member for clamping force output in a forward movement direction in which a piston rod is retracted by pressurized air, and a backward movement of the piston member opposite to the forward movement direction by pressurized air A clamp device that includes a second working chamber that is driven in a direction and an air supply passage that is connected to an external pressurized air supply source, and is capable of detecting an operating state via the air pressure of the air supply passage;
A fourth air passage connecting the air supply passage to the first working chamber;
A fourth on-off valve mechanism that is interposed in the fourth air passage and opens when the piston member reaches the return limit position;
When the piston member reaches the return limit position and the fourth on-off valve mechanism opens, the detection pressurized air is discharged to the first working chamber through the fourth air passage. And clamping device.