JP2010240775A - Clamp device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a clamp device preventing chips from intruding into a hole in a workpiece used for clamping. <P>SOLUTION: This clamp device C includes an annular grip member 2 inserted into the hole H in the workpiece W to grip an inner peripheral face of the hole, a clamp rod 3 having a tapered shaft part 31 fitted internally and internally engaged with the grip member 2, a hydraulic cylinder 4 capable of advancing the grip member 2 and the clamp rod 3 and backing and driving them axially, and a seating face 18 for seating the workpiece on it. The clamp device C has further a blocking member 100 for blocking the hole in the workpiece in an upper end part of the clamp rod 3. The blocking member has a blocking member body 101, a screw shaft part 102 protruding downward the blocking member body and being screw-fitted in a threaded hole 3a formed in the upper end part of the clamp rod 3, and an operation part 103. The blocking member body 101 has a brush 101a formed like a disc. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a clamping device that engages a grip claw of a grip member with a hole of a workpiece and attracts and clamps it with a clamp rod, and at least a blocking member that can prevent chips from entering the grip member is provided. About things.

  In the case of machining over the entire surface of the workpiece, a clamping device that presses the end of the workpiece with a pressing tool from above cannot be employed. Clamp device) is adopted. In this clamping device, a seating surface for seating a workpiece to be clamped is formed on the main body member, and the workpiece is mounted on and supported by the seating surface when the workpiece is inserted, and the grip member is inserted into the hole of the workpiece and the grip member is inserted After inserting the clamp rod with the taper shaft and pulling the clamp rod toward the seating surface, the grip claw is expanded by the taper shaft and engaged with the inner peripheral surface of the hole, The workpiece is fixed to the seating surface by pulling it toward the seating surface.

Patent Documents 1 and 2 disclose the clamping device as described above.
In particular, in the clamping device described in Patent Document 1, in order to cope with the variation in the position of the hole of the workpiece, a grip member and a clamp rod having a tapered shaft portion are configured to be movable in a direction orthogonal to the axis, Even when the position of the hole is slightly deviated from the original normal position, it can be surely clamped.

Japanese Patent No. 355010 German Patent No. 4020981

  In many cases, a penetrating hole is formed in the vertical direction as a hole for a workpiece into which the clamp rod and grip member of the clamp device are inserted. In this case, chips and coolant flow from the hole of the workpiece during machining of the workpiece, but when the chips and coolant flow, the gap between the grip member and the clamp rod, or between the grip member split bodies Chips are caught in the gap, and the clamping device does not operate normally.

When such a trouble occurs, it is necessary to blow air with pressurized air or to disassemble the clamp device to remove chips and the like, which takes a lot of time and labor, and the work efficiency is lowered. Moreover, the durability of the clamping device is also reduced by the chips.
An object of the present invention is to provide a clamping device provided with a closing member capable of closing a hole of a workpiece above the clamp rod so that at least a chip does not enter.

  The clamp device according to claim 1 is an annular grip member that can be inserted into a hole of a workpiece and grip an inner peripheral surface of the hole, a clamp rod having a tapered shaft portion that is fitted and engaged with the grip member, A clamping device having a fluid pressure cylinder capable of advancing and retracting a grip member and a clamp rod in an axial direction, a closing member fixed to an upper end portion of the clamp rod, wherein at least chips are directed toward the grip member. A blocking member capable of closing the hole of the workpiece is provided so as not to enter.

  Since the hole of the workpiece is closed by the closing member fixed to the upper end portion of the clamp rod, at least the chips do not enter the grip member.

  According to a second aspect of the present invention, in the clamp device according to the first aspect, the closing member is screwed into a closing member main body and a screw hole that protrudes downward from the closing member main body and is formed in the upper end portion of the clamp rod. And a screw shaft portion.

According to a third aspect of the present invention, the clamping device according to the second aspect of the invention is characterized in that the closing member main body has a brush formed in a disk shape.
A clamp device according to a fourth aspect is characterized in that, in the invention according to the second aspect, the closing member main body has a nonwoven fabric-like fiber laminate formed in a disc shape.

  According to a fifth aspect of the present invention, the clamping device according to the second aspect of the invention is characterized in that the closing member main body has a plurality of annular elastic disk members stacked in the vertical direction.

  According to a sixth aspect of the present invention, there is provided the clamping device according to the second aspect, wherein the closure member body is formed of a hollow elastic plug member made of an elastic material, and the elastic plug member is in a reduced diameter state smaller in diameter than the grip member. A drive mechanism that can be switched to an expanded state having a larger diameter than the member is provided.

  According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the drive mechanism includes a second fluid pressure cylinder that receives the fluid pressure of the fluid chamber for releasing the clamp of the fluid pressure cylinder, and the second fluid pressure. And a drive rod for switching the state of the elastic plug member in conjunction with the piston member of the cylinder.

  A clamp device according to an eighth aspect of the present invention is the invention according to the second aspect, wherein the closure member body includes an elastic container body that can be elastically deformed toward the diameter expansion side by fluid pressure, and a fluid chamber formed inside the elastic container body. A fluid pressure introducing means for introducing a fluid pressure into the fluid chamber in the elastic container is provided.

  According to a ninth aspect of the present invention, in the invention of the sixth aspect, the fluid pressure introducing means has a fluid passage for communicating the clamp release fluid chamber of the fluid pressure cylinder with the fluid chamber in the elastic container. It is said.

  According to a tenth aspect of the present invention, in the invention of the eighth aspect, the fluid pressure introducing means introduces pressurized air supplied from an external pressurized air supply source into the fluid chamber in the elastic container. It is characterized by being composed of introduction means.

  A clamp device according to an eleventh aspect is the clamp device according to any one of the second to tenth aspects, wherein the closure member is integrally provided between the closure member main body and the screw shaft portion and abuts on an upper end of the clamp rod. The operation unit is characterized in that an operation unit that can be rotated by a tool is provided.

  According to the first aspect of the present invention, the hole of the workpiece can be closed by the closing member fixed to the upper end portion of the clamp rod so that at least the chips do not enter the grip member. Chips do not enter the gap between the clamp rod and the grip member or the gap between the grip member divided bodies. For this reason, the chips do not adhere to the periphery of the grip member, so that the work for removing the chips does not occur, the work efficiency is improved, and the durability of the clamping device is also improved.

  According to the invention of claim 2, the closing member includes a closing member main body and a screw shaft portion that protrudes downward from the closing member main body and is screwed into a screw hole formed in an upper end portion of the clamp rod. Therefore, the closing member can be easily fixed to the clamp rod.

According to invention of Claim 3, since the said obstruction | occlusion member main body has the brush formed in disk shape, it can be easily inserted in the hole of a workpiece | work, and also when the size of the hole of a workpiece | work is not constant The hole can be reliably closed by deforming the brush.
According to invention of Claim 4, since the said obstruction | occlusion member main body has the nonwoven fabric-like fiber laminated body formed in disk shape, it can be easily inserted in the hole of a workpiece | work, and the size of the hole of a workpiece | work is constant. Even if not, the hole can be reliably closed by deforming the non-woven fiber laminate.

  According to the invention of claim 5, since the closing member main body has a plurality of annular elastic disk members stacked in the vertical direction, it can be easily inserted into the hole of the workpiece, and the size of the hole of the workpiece is constant. Even if not, the hole can be reliably closed by deforming the plurality of annular elastic disk members.

  According to invention of Claim 6, since the said closure member main body was comprised with the hollow elastic plug member, and provided the drive mechanism which can switch this elastic plug member to a diameter-reduced state and a diameter-expanded state, The hole in the workpiece can be reliably closed, and the blockage can be released.

  According to the seventh aspect of the present invention, the drive mechanism is interlocked with the second fluid pressure cylinder that receives the fluid pressure in the fluid chamber for releasing the clamp of the fluid pressure cylinder, and the piston member of the second fluid pressure cylinder. Thus, the state of the elastic plug member can be switched by effectively using the fluid pressure in the clamp release fluid chamber.

  According to invention of Claim 8, the said closure member main body has the elastic container body which can be elastically deformed to a diameter expansion side, and the fluid chamber inside this elastic container body, A fluid pressure is applied to the fluid chamber in this elastic container body. Since the fluid pressure introducing means to be introduced is provided, after inserting the closing member into the hole of the workpiece, the fluid pressure introducing means introduces the pressurized fluid into the fluid chamber inside the elastic container body, and elastically deforms it toward the diameter expansion side. The hole can be closed without a gap. In addition to chips, it is possible to reliably prevent coolant from flowing in.

  According to a ninth aspect of the present invention, the fluid pressure introducing means has a fluid passage for communicating a clamp releasing fluid chamber of the fluid pressure cylinder with a fluid chamber in the elastic container. Even when the workpiece is being clamped by the clamping device, the low pressure fluid pressure can be maintained in the fluid pressure working chamber for releasing the clamp. It is possible to maintain and close the hole of the workpiece.

  According to the invention of claim 10, the fluid pressure introducing means is constituted by a pressurized air introducing means for introducing pressurized air supplied from an external pressurized air supply source into the fluid chamber in the elastic container body. The elastic container body can be switched to the expanded diameter state with pressurized air.

  According to invention of Claim 11, it is an operation part which is integrally provided in the said closure member between the closure member main body and the screw shaft part, and contact | abuts the upper end of a clamp rod, Comprising: It can be rotated by a tool. Since the operating portion is provided, the closing member can be attached to and detached from the clamp rod simply and efficiently by rotating the operating portion with a tool.

It is a top view of the clamp device concerning the example of the present invention. It is a longitudinal cross-sectional view of a clamp apparatus (work input state). It is a perspective view of a closure member. It is a fragmentary longitudinal cross-sectional view of a clamp apparatus (clamp state). It is a partial longitudinal cross-sectional view of a clamp apparatus. It is explanatory drawing explaining the force of the up-down direction generate | occur | produced with the hydraulic cylinder for clamps. FIG. 6 is a diagram corresponding to FIG. 4 according to the second embodiment. FIG. 4 is a diagram corresponding to FIG. 4 according to the third embodiment. FIG. 2 is a diagram corresponding to FIG. 2 according to a fourth embodiment. FIG. 6 is a view corresponding to FIG. 4 according to the fourth embodiment. FIG. 6 is a diagram corresponding to FIG. 4 according to the fifth embodiment. FIG. 9 is a diagram corresponding to FIG. 4 according to the sixth embodiment.

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

  As shown in FIGS. 1 to 4, the clamping device C can drive the main body member 1, the grip member 2, the clamp rod 3, and the grip member 2 and the clamp rod 3 in the axial direction (vertical direction). A hydraulic cylinder 4, an annular pressure receiving member 5 included in the hydraulic cylinder 4, and a closing member 100 fixed to the upper end portion of the clamp rod 3 are provided. The body member 1 includes an upper body member 11, a lower body member 12, and a base body member 13.

  The upper body member 11 is substantially oval in plan view, and the upper body member 11 is fixed to the base body member 13 with four bolts (not shown) inserted into the four bolt holes 14. The lower main body member 12 is a cylindrical member that forms a cylinder hole 41, and the upper end portion of the lower main body member 12 is fitted into the concave portion 15 on the lower surface side of the upper main body member 11, and the upper main body member 11 is secured by four bolts 16. It is fixed to.

  As shown in FIGS. 1 to 4, the grip member 2 is disposed so as to vertically penetrate the opening hole 17 in the central portion of the upper main body member 11. Four arcuate seating surfaces 18 surrounding the grip member 2 are formed on the upper surface of the upper main body member 11, and the workpiece W can be seated on the seating surfaces 18 in a state where the workpiece W is clamped. On the upper surface of the upper body member 11, four concave grooves 19 through which air blow of pressurized air flows are formed in a cross shape. Except for the four seating surfaces 18 and the four concave grooves 19, the upper surface of the upper body member 11 is formed as a partial conical surface with a gentle inclination angle.

  The grip member 2 is a substantially annular member that can be inserted into the hole H of the workpiece W and grip the inner peripheral surface of the hole H. The grip member 2 includes a rod insertion hole 21 and a workpiece mounting surface 22 that can receive the workpiece W at a position on the advancing side (upper side) than the seating surface 18 when the grip member 2 is at the advancing position (upper limit position). An annular flange 23 forming the work mounting surface 22, a grip claw 24 extending outward (upward) from the annular flange 23, and a lower end opposite to the grip claw 24 with respect to the annular flange 23 A proximal end flange portion 26 formed in the portion, and an annular groove 25 formed between the annular flange portion 23 and the proximal end flange portion 26.

  The grip member 2 includes four grip divisions 2b in which an annular flange 23, a grip claw 24, an annular groove 25, and a proximal flange 26 are divided into four equal parts in the circumferential direction by a slit 27. The grip member 2 is made of a metal member, and three-step teeth 24a that make it easy to 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 24 of each grip divided body 2b. . The grip member 2 is formed with a rod insertion hole 21 through which the clamp rod 3 is inserted. It is formed in the hole 21a.

  As shown in FIGS. 1 to 4, a scraper 28 made of an elastic material such as rubber or synthetic resin is attached to the opening hole 17 of the upper body member 11 so as to be in sliding contact with the outer peripheral surface of the annular flange 23 of the grip member 2. Yes. In the annular groove 25 of the grip member 2, an O-ring 29 that urges the four divided grip bodies 2 b in the diameter-reducing direction is mounted in an outer fitting shape.

  The base end flange portion 26 of the grip member 2 is accommodated in the circular recess 6 of the upper body member 11 and is sandwiched between the upper wall portion of the circular recess 6 and the horizontal plate portion 62 of the annular pressure receiving member 5. The grip member 2 can be moved up and down integrally with the annular pressure receiving member 5, and the horizontal direction orthogonal to the axial center of the hydraulic cylinder 4 through elastic deformation of the annular gap 7 on the outer peripheral portion of the circular recess 6 and the scraper 28. It is mounted so as to be movable.

  The clamp rod 3 includes a tapered shaft portion 31, a small diameter rod portion 32 continuous with the lower end of the tapered shaft portion 31, a large diameter rod portion 33 continuous with the lower end of the small diameter rod portion 32, and a lower end of the large diameter rod portion 33. A large-diameter flange portion 34 that is connected to is integrally formed. The tapered shaft portion 31 and the small diameter rod portion 32 are inserted into the rod hole 21 of the grip member 2. The taper shaft portion 31 is formed at the upper end portion of the clamp rod 3 so as to increase in diameter toward the upper side, and the taper shaft portion 31 is fitted and engaged with the taper hole portion 21 a of the grip member 2.

  As shown in FIGS. 1 to 4, the hydraulic cylinder 4 is for driving the grip member 2 and the clamp rod 3 forward and backward in the axial direction. The hydraulic cylinder 4 has an upright cylinder hole 41 formed by the lower body member 12 and the base body member 13, a piston portion 43 mounted in the cylinder hole 41, and a cylindrical shape extending upward from the piston portion 43. A piston member 42 having a piston rod 44, a clamping oil chamber 45 above the piston portion 43, an unclamping oil chamber 46 below the piston portion 43, and the annular pressure receiving member 5 are provided.

  The bottom surface of the cylinder hole 41 is closed by the base body member 13, and a stop ring 47 that restricts the downward movement of the piston member 42 is attached to the annular groove near the lower end of the cylinder hole 41. The piston member 42 is received by the stop ring 47 and becomes the lower limit position. A central hole is formed in the piston member 42, and this central hole is composed of an upper small-diameter hole 48 formed in the cylindrical piston rod 44, a middle-diameter hole 49 in the middle step portion, and a lower large-diameter hole 50. Has been. A sealing member 51 is attached to the large-diameter hole 50 and is prevented from coming off by a stop ring 51a.

  The large-diameter rod portion 33 of the clamp rod 3 is located in the small-diameter hole 48, and the large-diameter collar portion 34 is located in the medium-diameter hole 49. An annular gap 35 of about 2 mm is formed between the large-diameter rod portion 33 and the inner peripheral surface of the small-diameter hole 48, and a thick O-ring 52 (elastic ring member) is attached to the annular groove on the outer periphery of the large-diameter rod portion 33. The O-ring 52 is mounted in a slightly compressed state between the large-diameter rod portion 33 and the cylindrical piston rod 44.

  The thickness of the large diameter flange 34 is substantially equal to the thickness of the medium diameter hole 49. A slight gap is formed between the outer peripheral surface of the large diameter flange 34 and the inner peripheral surface of the medium diameter hole 49. Therefore, the clamp rod 3 moves up and down integrally with the piston member 42, but is movable relative to the piston member 42 in the horizontal direction perpendicular to the axis. The grip member 2 can move in the horizontal direction orthogonal to the axis center together with the clamp rod 3. Here, the scraper 28 and the O-ring 52 elastically bias the grip member 2 and the clamp rod 3 so that the axes of the grip member 2 and the clamp rod 3 coincide with the axis of the hydraulic cylinder 4.

  As shown in FIGS. 1 to 4, the annular pressure receiving member 5 has a pressure receiving cylinder portion 61 and an annular horizontal plate portion 62 that is continuous with the upper end of the pressure receiving cylinder portion 61. The proximal end collar portion 26 of the grip member 2 is placed and the proximal end surface of the grip member 2 is supported. The large-diameter rod portion 33 of the clamp rod 3 is inserted into the circular hole 63 at the center of the horizontal flat plate portion 62 in a loose fit. A locking rod 62 a having a slightly larger diameter than the pressure receiving cylinder portion 61 is formed on the outer peripheral portion of the horizontal plate portion 62. The lower main body member 12 is formed with an upper cylinder hole 64 having a smaller diameter than the cylinder hole 41 connected to the upper end of the cylinder hole 41.

  The upper body member 11 is formed with a receiving hole 65 that is continuous with the upper end of the upper cylinder hole 64. The thickness of the accommodation hole 65 is, for example, about 1.2 to 2.0 mm larger than the thickness of the horizontal plate portion 62. The pressure receiving cylinder portion 61 of the annular pressure receiving member 5 is mounted in an annular hole between the inner peripheral surface of the upper cylinder hole 64 and the cylindrical piston rod 44 in an oil-tight manner and slidable in the vertical direction. The housing hole 65 is slidably mounted in the vertical direction. A plurality of seal members (not shown) are provided to prevent hydraulic oil leakage from the oil chambers 45 and 46.

  The lower end of the pressure receiving cylinder portion 61 of the annular pressure receiving member 5 faces the clamping hydraulic chamber 45 and receives the hydraulic pressure. The clamping oil chamber 45 is connected to a hydraulic pressure supply source via oil paths 66 to 69, and a hydraulic pressure detection sensor 70 that detects the hydraulic pressure P <b> 1 of the oil path 69 is also provided. The unclamping oil chamber 46 is connected to a hydraulic pressure supply source via oil passages 71 and 72, and a hydraulic pressure detection sensor 73 for detecting the hydraulic pressure P2 of the oil passage 72 is also provided. The annular pressure receiving member 5 includes a first position where the work mounting surface 22 of the grip member 2 is located outward (upward) from the seating surface 18, and a position where the work mounting surface 22 is retracted (lowered) from the seating surface 18. A predetermined stroke is movable in the axial direction over the second position.

  As shown in FIGS. 1 to 4, a seating sensor 80 that detects that the lower surface of the work W is in close contact with the seating surface 18 in a state where the work W is clamped is provided. The seating sensor 80 includes a pressurized air ejection hole 81 opened in the seating surface 18, an air passage 82 formed in the upper body member 11 so as to communicate with the pressurized air ejection hole 81, and the base body member 13. An air passage 83 formed therein, a pressurized air supply source for supplying pressurized air to the air passage 83, and detecting that the pressure of the pressurized air in the air passage 83 has increased to a predetermined value or more. A pressure switch 84 or the like is used.

  As shown in FIG. 1, an air passage 90 similar to the air passage 82 is formed in the upper main body member 11, and pressurized air is supplied from the air passage 90 to the circular recess 6 and the annular groove 25. The four slits 27 of the grip member 2 flow toward the four seating surfaces 18, and the four seating surfaces 18 are air blown to clean the seating surfaces 18.

Next, the closing member 100 will be described.
As shown in FIGS. 2 to 4, in a state in which the workpiece W is clamped by the clamping device C, the chips that have flowed into the hole H when the upper surface of the workpiece W is machined enter the grip member 21. A blocking member 100 for preventing is attached to the upper end portion of the clamp rod 3 and configured to close the hole H on the upper side of the clamp rod 3.

  The closing member 100 includes a closing member main body 101, a screw shaft portion 102 that projects downward from the closing member main body 101 and is screwed into a screw hole 3 a formed in the upper end portion of the clamp rod 3, and the closing member main body. 101 and an operation part 103 provided integrally between the screw shaft part 102. The closing member main body 101 is composed of a brush 101a formed in a disc shape. The brush 101a is made by implanting a large number of flexible thin wire rods made of synthetic resin or metal into a wire rod holding portion 104a on the outer peripheral side of the shaft portion 104 integral with the screw shaft portion 102 in a dense state. It is.

  The operation portion 103 is used to rotate the closing member 100 with a hexagon wrench when the screw shaft portion 102 is screwed into the screw hole 3a of the clamp rod 3 when the closing member 100 is fixed to the clamp rod 3. Is. In a state where the closing member 100 is fixed to the upper end portion of the clamp rod 3, the operation unit 103 comes into contact with the upper end of the clamp rod 3.

The outer diameter of the closing member main body 101 is set to be slightly larger than the outer diameter of the grip claw portion 24 in the expanded state (clamped state). The hole H is configured to be in contact with the inner surface of the hole H of the W to close the hole H. Since the thin wire rods of the brush 101a are in a dense state, at least the chips do not penetrate through the closing member body 101 and enter the lower side, but the amount of coolant that flows through the closing member body 101 and flows downward is also significant. Less.
The hydraulic pressure supply source, the pressurized air supply source, the hydraulic pressure detection sensors 70 and 73, the pressure switch 84, and the like are electrically connected to a control unit (not shown) and controlled by the control unit.

The operation and effect of the clamping device C will be described.
When the workpiece W is fixed by the clamping device C, first, substantially the same hydraulic pressure is supplied to the clamping oil chamber 45 and the unclamping oil chamber 46. Then, since the pressure receiving area of the unclamping oil chamber 46 is larger than the pressure receiving area of the clamping oil chamber 45 in the piston member 42, the piston member 42 is raised to the upper limit position and stopped as shown in FIG. It becomes. Further, the annular pressure receiving member 5 holds the upper limit position for receiving the hydraulic pressure of the clamping oil chamber 45, the grip member 2 also holds the upper limit position, and the work mounting surface 22 maintains a position slightly higher than the seating surface 18. To do.

  In this state, the workpiece W is loaded, and as shown in FIG. 2, the grip member 2, the clamp rod 3 and the closing member 100 are inserted into the hole H of the workpiece W, and the workpiece W is supported by the workpiece mounting surface 22. In this way, the work W is initially supported by the work mounting surface 22 at a position higher than the seating surface 18, and then the work is supported by the seating surface 18 in the clamped state. Can be prevented from being damaged by the workpiece W, and the seating sensor 80 does not operate before clamping, and the seating sensor 80 is seated when the workpiece W is seated on the seating surface 18 and fixed with the intended clamping force. Since it comes to operate | move, the reliability of the seating sensor 80 can be improved.

  Next, the hydraulic pressure of the unclamping oil chamber 46 is switched to a predetermined hydraulic pressure lower than the hydraulic pressure of the clamping oil chamber 45, and a predetermined hydraulic pressure that is somewhat strong downward is applied to the piston member 42. Then, the annular pressure receiving member 5 that receives the hydraulic pressure of the clamping oil chamber 45 holds the upper limit position as described above, and the grip member 2 also holds the upper limit position. However, the piston member 42 receives downward oil pressure. Since the piston member 42 is actuated and driven downward, the piston member 42 moves downward relative to the grip member 2.

  As a result, the grip claw portion 24 of the grip member 2 is driven to expand in diameter by the taper shaft portion 31 of the clamp rod 3, and is engaged with the inner peripheral surface of the hole H of the workpiece W to be in an engaged state (grip state). In this state, if the hydraulic pressure in the unclamping oil chamber 46 is reduced to the drain pressure, a large downward hydraulic pressure acts on the piston member 42, and the grip member 2 and the clamp rod 3 are not relatively movable. 4, the piston member 42, the grip member 2, the clamp rod 3, and the annular pressure receiving member 5 are integrally driven downward so that the workpiece W is seated on the seating surface 18 and is strongly pressed. Stop to become.

  Here, the relationship between the operation of gripping the inner peripheral surface of the hole H of the workpiece W and the operation of clamping the workpiece W will be described in detail with reference to FIG. The hydraulic pressure supplied to the clamping oil chamber 45 is P1, the hydraulic pressure supplied to the unclamping oil chamber 46 is P2, FI indicates an upward force acting on the grip member 2 by the hydraulic pressure P1, and FII is the hydraulic pressure P1 and the hydraulic pressure. A downward force acting on the clamp rod 3 is indicated by P2.

  Since the hydraulic pressure P1 is maintained constant from the beginning, F1 is maintained at Fc, but after the workpiece W is supported by the mounting surface 18 and the grip member 2 and the clamp rod 3 are inserted into the hole H of the workpiece W. The hydraulic pressure P2 is reduced, and at that time, the force FII is applied downward to the clamp rod 3, and the force FII increases as the hydraulic pressure P2 decreases. Here, at least in a state where FII is lower than Fc, the grip member 20 receives FII from the clamp rod 3 and expands its diameter without being dragged downward by the clamp rod 3.

  When FII is larger than Fc, the grip member 2 and the clamp rod 3 are integrally lowered and the clamping operation is started. By this time, the grip member 2 receives the maximum force of Fc and is sufficient. Since the grip member 2 securely grips the workpiece W and can start the clamping operation in this state, the grip claw portion 24 slips downward relative to the inner peripheral surface of the hole H of the workpiece W. It is possible to reliably prevent the workpiece W from being securely clamped.

In the state where the workpiece W is clamped, when the cutting process is performed on the upper surface side of the workpiece W, the hole H is formed by the closing member 100 above the clamp rod 3 even if chips are scattered at the hole. Since it is closed, the chips do not enter the grip member 2 side.
Further, even if coolant (cooling coolant for cutting) flows into the hole H, the coolant flow is blocked by the closing member 100 and chips on the upper surface side thereof, so that the coolant passes through the closing member 100 to the grip member 2 side. The amount of coolant flowing is very small.

  The closing member 100 includes a closing member main body 101, a screw shaft portion 102 that projects downward from the closing member main body 101 and is screwed into a screw hole 3 a formed in the upper end portion of the clamp rod 3, and an operation portion 103. Therefore, the closing member 100 can be easily fixed to the clamp rod 3. Moreover, since the closing member main body 101 has a brush formed in a disc shape, it can be easily inserted into the hole H of the workpiece W, and the brush can be used even when the size of the hole H of the workpiece W is not constant. By deforming, the hole can be reliably closed.

  When the workpiece W is clamped by a plurality of clamping devices C, when the position of the center of the hole H of the workpiece W is slightly shifted due to the manufacturing error of each workpiece W, the clamp rod 3 and the grip member 2 are moved. When inserted into the hole H or clamped, the shaft centers of the clamp rod 3 and the grip member 2 are displaced from the shaft center of the hydraulic cylinder 4 through elastic deformation of the scraper 28 and the O-ring 52.

  However, when the clamping device C is returned to the unclamped state after machining the workpiece W, the axial center of the clamp rod 3 and the grip member 2 is made to be the axial center of the hydraulic cylinder 4 by the elastic force of the scraper 28 and the O-ring 52. Automatically return to match. In this case, since the elastic force is applied to the clamp rod 3 at two places, the upper and lower positions, the clamp rod 3 can be returned smoothly without looseness.

  Therefore, it is not necessary to manually perform a return operation for making the two axes coincide with each other in the unclamped state, so that the work efficiency of the work clamping operation can be increased. In addition, the O-ring 52 reliably prevents chips and coolant from entering the sliding portion between the large-diameter flange 34 of the clamp rod 3 and the medium-diameter hole 49 of the cylindrical piston rod 44. Smooth sliding movement in the direction orthogonal to the axial direction of 3 can be reliably ensured.

  When the clamp is released after completion of the cutting process, when the pressurized air is supplied from the air passage 90 before the workpiece W is removed or after the workpiece W is removed, the circular recess 6 and the annular groove 25 are supplied from the air passage 90. Since the pressurized air is supplied to the nozzle member 4 and the pressurized air is ejected from the four slits 27 of the grip member 2, the chips and coolant adhering to the upper surface side of the brush of the closing member 100 are removed by air blowing.

  Therefore, chips and coolant adhering to the closing member 100 can be removed by a simple operation of simply supplying pressurized air to the air passage 90. Therefore, air blow is performed manually to remove chips. Or the work of disassembling the clamp device C and air blowing is not required, so that the productivity of the work can be improved and the durability of the clamp device can be prevented from being lowered due to the biting of chips or the like. .

  In the present embodiment, the same components as those of the clamping device C are denoted by the same reference numerals, description thereof is omitted, and only different components are described. As shown in FIG. 7, in this clamping device CA, only the structure of the closing member 100A is changed. The closing member main body 101A is mainly composed of a non-woven fiber laminate 101b formed in a disc shape.

  This nonwoven fabric-like fiber laminate 101b is obtained by laminating synthetic resin thin wire rods in a nonwoven fabric shape and bonding them with an adhesive, and has flexibility and air permeability. The closing member 100A includes a closing member main body 101A, a screw shaft portion 102, an operation portion 103, and a shaft portion 104A extending upward from the operation portion 103. The nonwoven fabric fiber laminate 101b is formed on the shaft portion 104A. It is externally fitted and bonded. In the clamped state, the outer peripheral portion of the nonwoven fabric-like fiber laminate 101b comes into contact with the inner peripheral surface of the hole H.

  According to this closing member 100A, the same operation and effect as the closing member 100 of the above-described embodiment are exhibited. Since the nonwoven fabric fiber laminate 101b has air permeability, chips on the upper surface side of the closing member 100A can be removed by air blowing with pressurized air supplied to the air passage 90 after cutting.

  Unlike the brush 101a, the non-woven fiber laminate 101b can make the ventilation holes into small ventilation holes throughout the whole, so that it can further enhance the function of preventing chips from entering. Moreover, the intrusion prevention performance of the coolant can be enhanced. The non-woven fiber laminate 101b formed in a disk shape can be easily inserted into the hole H of the workpiece W. Even when the size of the hole H of the workpiece W is not constant, the hole can be reliably closed by deforming the non-woven fiber laminate 101b.

  In the present embodiment, the same components as those of the clamping device C are denoted by the same reference numerals, description thereof is omitted, and only different components are described. In the clamp device CB, only the structure of the closing member 100B is changed. As shown in FIG. 8, the closing member 100B includes a closing member main body 101B, a screw shaft portion 102, an operation portion 103, and a shaft portion 104B. The closing member main body 101B has a plurality of annular elastic disk members 101c stacked in the vertical direction. The elastic disk member 101c is made of elastic rubber or synthetic resin, and the thickness gradually decreases from the center side toward the outer peripheral side. Therefore, the three elastic disk members 101c can be elastically deformed in the vertical direction when inserted into the hole H of the workpiece W or when the clamp is operated.

In the clamped state, the outer peripheral portions of the three elastic disk members 101c abut against the inner peripheral surface of the hole H and close the hole H with almost no gap, so that chips can be reliably prevented from entering the grip member 2 side. In addition, the amount of coolant entering the grip member 2 side is also zero or very small.
Since the closure member main body 101B has a plurality of annular elastic disk members 101c stacked in the vertical direction, the closure member main body 101B can be easily inserted into the hole H of the workpiece W, and even if the size of the hole H of the workpiece W is not constant, By deforming the elastic disk member 101c, it can be easily inserted into the hole H and the hole H can be reliably closed. In addition, this closing member 100B also has the same operations and effects as the closing member 100 of the above embodiment.

  In the present embodiment, the same components as those of the clamping device C of the above embodiment are denoted by the same reference numerals, description thereof is omitted, and only different components are described. As shown in FIG. 9, in this clamping device CC, only the closing member 100C and its drive mechanism 100k are changed.

  The closing member 100C includes a closing member main body 101C, a screw shaft portion 102, an operation portion 103, a drive mechanism 100K, and the like. The closing member main body 101C is made of a synthetic resin hollow elastic plug member 101d having elasticity as an elastic material. The drive mechanism 100K includes a hydraulic cylinder 94 that receives the hydraulic pressure of the unclamping oil chamber 46, a drive rod 105 that is inserted into the clamp rod 3 so as to be movable up and down, a return spring 106, and the like.

  When the drive mechanism 100k is in the unclamped state, the closing member body 101C is in a reduced diameter state that does not close the hole H of the workpiece W as shown in FIG. 9, and in the clamped state, as shown in FIG. The diameter of the hole H is closed. In the drive mechanism 100k, the hydraulic cylinder 94 has a cylinder hole 94a formed in the sealing member 51 attached to the piston portion 43 of the hydraulic cylinder 4, and a piston member 107 attached to the cylinder hole 94a. The drive rod 105 is mounted in a shaft hole formed in the shaft center portion of the clamp rod 3 so as to be movable up and down. The upper end of the drive rod 105 is fixed to the upper end portion of the closing member main body 101C, and the lower end of the drive rod 105 is A portion 105a is formed.

  The flange 105a can be moved up and down in a recess 108 formed in the lower end portion of the clamp rod 3, and the upper end of the piston rod of the piston member 107 of the hydraulic cylinder 94 is in contact with the lower surface of the flange 105a. A return spring 106 made of a compression coil spring is mounted in the spring accommodating hole at the lower part of the clamp rod 3, and the lower end of the return spring 106 is received by the flange portion 105a, and the drive rod 105 is urged downward by the return spring 106. .

  In the clamp release state shown in FIG. 9, the piston member 107 and the drive rod 105 are raised by the hydraulic pressure supplied to the unclamping oil chamber 46, and the closing member main body 101C is extended upward to be in a reduced diameter state. In this reduced diameter state, the closing member main body 101C has a smaller diameter than the grip claw portion 24 of the grip member 2, so that the grip member 2 and the clamp rod 3 can be smoothly inserted into the hole H of the workpiece W.

  In the clamped state shown in FIG. 10, since the hydraulic pressure in the unclamping oil chamber 46 becomes the drain pressure, the drive rod 105 and the piston member 107 are lowered by the urging force of the return spring 106, and the closing member main body 101C is expanded. Thus, the hole H of the workpiece W is completely closed. Therefore, chips and coolant do not flow into the hole H at all. Note that the return spring 106 may be omitted and the diameter may be increased as shown in FIG. 10 by the elastic force of the closing member main body 101C in the clamped state. The elastic plug member 101d may be formed in a solid shape with a soft elastic material instead of being formed in a hollow shape.

  In the present embodiment, the same components as those of the clamping device C of the above embodiment are denoted by the same reference numerals, description thereof is omitted, and only different components are described. As shown in FIG. 11, in this clamping device CD, only the closing member 100D is changed. The closing member 100D includes a closing member main body 101D, a screw shaft portion 102, and an operation portion 103.

  The closing member body 101D has an elastic container body 101e that can be elastically deformed into a diameter state by hydraulic pressure, and a hydraulic chamber 110 formed inside the elastic container body 101e. The oil passage 111 has a small diameter as a hydraulic introduction means for introducing hydraulic pressure into the hydraulic chamber 110 in the elastic container body 101e, and the unclamping oil chamber 46 of the hydraulic cylinder 4 is connected to the hydraulic chamber 110 in the elastic container body 101e. An oil passage 111 for communication is provided. The oil passage 111 is an oil passage that penetrates the sealing member 51, the clamp rod 3, the screw shaft portion 102, and the operation portion 103.

  The elastic container body 101e is a high-strength container made of rubber containing reinforcing fibers that is not damaged by the hydraulic pressure supplied to the unclamping oil chamber 46. In a state where the hydraulic chamber 110 of the elastic container body 101e is not filled with hydraulic pressure, the outer diameter of the elastic container body 101e is slightly smaller than the outer diameter of the grip claw portion 24. However, in a state where the hydraulic chamber 110 of the elastic container body 101e is filled with hydraulic pressure, the elastic container body 101e is elastically deformed toward the diameter expansion side, and the outer peripheral surface of the elastic container body 101e is pressed against the inner peripheral surface of the hole H. It becomes a state.

  In the clamp device CD, when the clamp rod 3, the grip member 2, and the closing member 100D are inserted into the hole H of the workpiece W, the hydraulic pressure of the unclamping oil chamber 46 is kept at a low pressure or a drain pressure, and the elastic container body 101e. Is inserted in a state where it is not elastically deformed into an expanded state. Thereafter, the clamping device CD is operated to be clamped in the unclamping oil chamber 46 while maintaining a predetermined hydraulic pressure necessary to elastically deform the elastic container body 101e in the expanded state.

  Therefore, in the clamped state, the elastic container body 101e is elastically deformed in the expanded diameter state and the state where the hole H is closed without a gap is maintained, and the workpiece W is cut in the closed state. Therefore, it is possible to reliably prevent chips and coolant generated during the cutting of the workpiece W from entering the grip member 2 from the hole H.

  When releasing the clamp, the hydraulic pressure in the clamp oil chamber 45 is released, the hydraulic pressure in the unclamp oil chamber 46 is increased, and the clamp rod 3 is moved upward relative to the grip member 2 to reduce the diameter of the grip member 2. When the hydraulic pressure in the unclamping oil chamber 46 is lowered below the predetermined pressure after switching to the state, the elastic container body 101e is in a reduced diameter state. In this state, the workpiece W is removed. Since the hydraulic pressure of the unclamping oil chamber 46 is supplied to the hydraulic chamber 110 in the elastic container body 101e through the oil passage 111, the structure of the oil passage for supplying hydraulic pressure to the hydraulic chamber 110 can be simplified. . In addition, the same operation and effect as the closing member 100 can be obtained.

  In the present embodiment, the same components as those of the clamping device C of the above embodiment are denoted by the same reference numerals, description thereof is omitted, and only different components are described. As shown in FIG. 12, in this clamping device CE, only the closing member 100E is changed. The closing member 100E includes a closing member main body 101E, a screw shaft portion 102, and an operation portion 103.

  The closing member main body 101E is composed of an elastic container body 101f made of synthetic resin having elasticity, and an air chamber 120 is formed inside the elastic container body 101f. In a state where pressurized air is not supplied to the air chamber 120, the elastic container body 101 f is in a reduced diameter state with a smaller diameter than the grip member 2. In a state where pressurized air is supplied to the air chamber 120, the elastic container body 101 f is in an expanded state with a larger diameter than the grip member 2.

  In order to supply pressurized air to the elastic container body 101f, an air passage 90 in the upper main body member 11, an air passage 91 in the lower main body member 12, an air passage 92 connected to an air supply source, and the clamp rod 3 Air passages 121 and 122 are formed. The pressurized air supplied through the air passage 90 flows into the circular hole 63 through the circular recess 6 and the slit between the grip divisions 2b, and the air passes through the air passages 121 and 122 from the circular hole 63. Flows into the chamber 120.

  Before putting the workpiece W, pressurized air is supplied from the air supply source to the air passages 92, 91, 90, and the slits between the grip divided bodies 2b and the seating surface 18 are cleaned. At this time, the pressurized air flows into the air chamber 120 in the elastic container body 101f through the air passages 121 and 122, and the diameter is expanded. Thereafter, in a state where the supply of pressurized air is stopped to reduce the diameter of the elastic container body 101f and the hydraulic pressure is supplied to the unclamping oil chamber 46, the workpiece W is introduced and the grip member 2 is inserted into the hole H of the workpiece W. And the clamp rod 3 are inserted.

  After the insertion, when hydraulic pressure is supplied to the clamping oil chamber 45 and pressurized air is supplied from the pressurized air supply source to the air passage 92, it is also applied to the air chamber 120 in the elastic container body 101f in the same manner as described above. The compressed air flows in, the elastic container body 101f is in a diameter-expanded state, and comes into contact with the inner peripheral surface of the hole H. Thus, when the hole H is closed, the pressurized air flowing upward from the slits between the grip divisions 2b is also confined in the hole H, so that the air pressure rises to about the air pressure in the air passage 92 and is elastic. The container body 101f comes into pressure contact with the inner peripheral surface of the hole H. In this state, the workpiece W is cut. At this time, even if chips and coolant flow into the top of the hole H, the hole H is completely closed by the closing member 100E, so that the chips and coolant do not flow toward the grip member 2.

  In order to remove the workpiece W upward after stopping the supply of the pressurized air after the cutting process to the workpiece W is stopped, the air pressure in the air chamber 120 is almost atmospheric pressure, the elastic container body 101f is in a reduced diameter state, The durability of the elastic container body 101f can be ensured. In the case of the closing member 100E, short air passages 121 and 122 may be formed in the clamp rod 3 in order to effectively use the air passages 92, 91, and 90 for supplying pressurized air for cleaning the seating surface 18 and the like. Therefore, the structure of the air passage is simplified and the structure of the elastic container body 101f is also simplified. While the elastic container body 101f is in the expanded state and the workpiece W is cut, the pressurized air is not released into the atmosphere, so the consumption of the pressurized air can be reduced.

An example in which the embodiment described above is partially changed will be described.
1] Instead of the hydraulic cylinder 4, an air cylinder that operates with pressurized air may be provided.
2] Instead of the oil passage 111 of the fifth embodiment, an oil passage for supplying hydraulic pressure from the oil chamber 45 for clamping to the hydraulic chamber 110 of the elastic container body 101e may be formed.
3] Those skilled in the art can implement the present invention by adding various modifications to the above embodiment, and the present invention includes such modifications.

  The clamping device of the present invention can be used as a device for clamping a workpiece when cutting various metal workpieces with a machine tool.

W Work H Hole C, CA to CE Clamping device 1 Main body member 2, Grip member 2b Grip segment 3 Clamp rod 4 Hydraulic cylinder 45 Clamping oil chamber 46 Unclamping oil chamber 90 Air passage 94 Hydraulic cylinders 100, 100A to 100E Closing member 101, 101A to 101E Closing member body 100k Drive mechanism 101a Brush 101b Non-woven fiber laminate 101c Elastic disk member 101d Elastic plug member 101e Elastic container body 101f Elastic container body 102 Screw shaft portion 103 Operation portion 105 Drive rod 106 Return spring 110 Hydraulic chamber 111 Oil passage 121, 122 Air passage

Claims (11)

An annular grip member that can be inserted into the hole of the workpiece and grip the inner peripheral surface of the hole, a clamp rod having a taper shaft portion fitted and engaged with the grip member, and the grip member and the clamp rod In a clamping device having a fluid pressure cylinder capable of moving forward and backward in the center direction,
A clamping device, comprising: a closing member fixed to an upper end portion of the clamp rod, wherein a closing member capable of closing a hole in the workpiece is provided so that at least chips do not enter the grip member.   The said closure member has a closure member main body, and the screw-shaft part which protrudes below this closure member main body, and is screwed by the screw hole formed in the upper end part of a clamp rod, It is characterized by the above-mentioned. The clamp apparatus as described in.   The clamping device according to claim 2, wherein the closing member body includes a brush formed in a disk shape.   The clamping device according to claim 2, wherein the closing member main body has a non-woven fiber laminate formed in a disk shape.   The clamping device according to claim 2, wherein the closing member main body includes a plurality of annular elastic disk members stacked in the vertical direction.   The closure member body is formed of a hollow elastic plug member made of an elastic material, and the elastic plug member can be switched between a reduced diameter state smaller in diameter than the grip member and an enlarged diameter state larger in diameter than the grip member. The clamping device according to claim 2, wherein a mechanism is provided.   The drive mechanism switches the state of the elastic plug member in conjunction with the second fluid pressure cylinder that receives the fluid pressure in the fluid chamber for releasing the clamp of the fluid pressure cylinder and the piston member of the second fluid pressure cylinder. The clamp device according to claim 6, further comprising a drive rod.   A fluid that introduces fluid pressure into the fluid chamber in the elastic container body, wherein the closing member body has an elastic container body that can be elastically deformed to the enlarged diameter side by fluid pressure, and a fluid chamber formed inside the elastic container body 3. The clamping device according to claim 2, further comprising pressure introducing means.   9. The clamping apparatus according to claim 8, wherein the fluid pressure introducing means has a fluid passage that communicates a clamp releasing fluid chamber of the fluid pressure cylinder with a fluid chamber in the elastic container.   9. The fluid pressure introducing means comprises pressure air introducing means for introducing pressurized air supplied from an external pressurized air supply source into a fluid chamber in the elastic container. The clamping device as described.   The closing member is provided with an operation portion that is integrally provided between the closing member main body and the screw shaft portion and that is in contact with the upper end of the clamp rod and that can be rotated by a tool. The clamp apparatus as described in any one of Claims 2-10 to do.

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