JP2008100340A - Collet clamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collet clamp which powerfully drives a collet. <P>SOLUTION: An upwardly-narrowed and tapered outer-peripheral face (18) is provided at a plug part (16) integrally protruded upwardly from a reference member (1). An output part (24) inserted into a circular hole (4) of a workpiece pallet (2) is provided at the outer-peripheral lower part of a driving member (22) vertically moved with respect to the plug part (16). An inner protrusion (26) protruding radially inwardly and an inner-peripheral groove (27) retracted radially outwardly are upwardly and successively provided at the lower end part of the output part (24). A collet (29) is provided with a slit (30), a straight outer-peripheral face (31), which can be brought into contact with the inner-peripheral face of the circular hole (4), and a tapered inner-peripheral face (32) that is engaged with the tapered outer-peripheral face (18) from above. An outer-peripheral groove (35) fitted with the inner protrusion (26) and an outer protrusion (36) fitted into the inner-peripheral groove (27) are upwardly and successively provided at the upper end part of the collet (29). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a clamp using a collet that can be expanded and contracted in the diameter direction, and more specifically, to a technique for positioning and fixing a movable member such as a work pallet to a reference member such as a machine table.

Conventionally, this type of collet clamp has been described in the following Patent Document 1 (Japan, Japanese Patent Application Laid-Open No. 2006-175573) previously proposed by the assignee of the present invention. The prior art is configured as follows.
A tapered outer peripheral surface that narrows upward is provided on the plug portion that protrudes upward from the reference member. An output portion is provided on the upper portion of the drive bolt that is moved in the vertical direction with respect to the plug portion, and an outer protrusion that protrudes radially outward and an outer circumferential groove that retreats radially inward are provided at the output portion. Are provided in order upward. And the collet with a slit is arrange | positioned on the outer peripheral side of the said taper outer peripheral surface, and the inner processus | protrusion which protrudes inward of a radial direction so that it may fit in said outer peripheral groove is provided in the upper part of the collet.
JP 2006-175573 A

In the above prior art, it is necessary to cover the upper part of the collet with a cover tube in order to prevent foreign substances in the atmosphere from entering the tapered outer peripheral surface through the slit of the collet. For this reason, the number of parts of the collet clamp increases and the configuration becomes complicated.
Further, when the collet is driven to lock downward with respect to the plug portion, the collet is enlarged in diameter, so that the inner projection of the collet and the outer projection of the plug portion overlap in the radial direction. The dimensions are reduced, and the contact area between the two is reduced. For this reason, there remains room for improvement in strongly locking the collet.
An object of the present invention is to provide a collet clamp that can be driven strongly with a simple configuration.

In order to achieve the above object, according to the present invention, for example, as shown in FIGS. 1A to 2 or FIGS. 4 to 6, the collet clamp is configured as follows.
A tapered outer peripheral surface (18) narrowing in the distal direction is provided on the plug portion (16) projecting from the reference member (1) in the distal direction. An output part (24) provided in the drive member (22) moved in the axial direction relative to the plug part (16), the output part being inserted into the circular hole (4) of the movable member (2) An inner protrusion (26) projecting radially inward and an inner circumferential groove (27) retreating radially outward are sequentially provided in the proximal end of (24) in the distal direction. A slit (30) for allowing expansion and contraction in the diameter direction, a straight outer peripheral surface (31) capable of contacting the inner peripheral surface of the circular hole (4), and a distal end side on the tapered outer peripheral surface (18) An outer peripheral groove (35) recessed inward in the radial direction so as to be fitted to the inner protrusion (26) at the tip of a collet (29) having a tapered inner peripheral surface (32) engaged from ) And an outer protrusion (36) protruding outward in the radial direction so as to fit in the inner circumferential groove (27).

The present invention has the following effects.
Since the upper part of the slit of the collet is covered by the lower part of the output part of the driving member, foreign matter in the atmosphere can be prevented from entering the tapered outer peripheral surface through the slit. Therefore, unlike the prior art, the collet-type clamp of the present invention does not require the provision of a dedicated cover cylinder for covering the upper part of the collet. The total height can be reduced by omitting the installation space for the cover tube.
Further, when the collet is driven to be locked with respect to the plug portion to expand the diameter of the collet, the overlapping dimension in the radial direction between the outer protrusion of the collet and the inner protrusion of the output portion increases. For this reason, the contact area between the two is increased, and the collet can be locked and driven strongly.
As described above, the present invention can provide a collet clamp that can be driven strongly with a simple configuration.

In the present invention, for example, as shown in FIGS. 4 to 6, the base end surface (26a) of the inner protrusion (26) of the output portion (24) is used as the distal end surface of the plug portion (16). It is preferable to arrange on the base end side with respect to (16a).
In this case, the outer peripheral upper portion of the plug portion is reliably covered by the lower outer peripheral portion of the output portion of the drive member. For this reason, it can prevent reliably that the foreign material in atmosphere bites between the said taper outer peripheral surface and a taper inner peripheral surface.

In the present invention, for example, as shown in FIG. 2, the base end surface (26a) of the inner protrusion (26) of the output portion (24) is connected to the tapered portion (19) of the plug portion (16). It is preferable to arrange the base end side of the front end face (19a).
Also in this case, the outer periphery upper part of the taper part is reliably covered with the outer periphery lower part of the output part of a drive member. For this reason, it is possible to reliably prevent foreign matter in the atmosphere from being caught between the tapered outer peripheral surface and the tapered inner peripheral surface of the tapered portion.

In the present invention, for example, when the collet (29) is forcibly reduced in diameter by a jig shown in FIG. 3, the outer diameter dimension of the outer protrusion (36) of the collet (29) is It is preferable to set a value smaller than the inner diameter dimension of the inner protrusion (26) of the output portion (24).
In this case, the collet can be easily and reliably assembled to the output portion of the drive member.

  1A, 1B, and 2 show a first embodiment of the present invention. In the first embodiment, a work pallet positioning device using a collet clamp is illustrated. FIG. 1A is a sectional view of the collet-type clamp in an elevational view. FIG. 1B is a partial view of the right side view of FIG. 1A described above. FIG. 2 is an operation explanatory view of the above positioning device, in which the left half view shows the released state and the right half view shows the locked state.

A work pallet 2 as a movable member is positioned by a collet clamp 3 on a reference member 1 such as a machine table or a clamp pallet. In the work pallet 2, a circular hole 4 is formed straight in the vertical direction in plan view.
A large-diameter hole 6, a fitting hole 7, and a female screw hole 8 are formed in the reference member 1 in order downward. A plurality of bosses 10 protrude upward from the upper surface of the peripheral wall of the large-diameter hole 6. A support surface 11 formed on the upper surface of each boss 10 receives the supported surface 2 a below the work pallet 2.

The housing 3a of the clamp 3 includes a flange portion 13 inserted into the large-diameter hole 6, a fitting portion 14 inserted into the fitting hole 7, and a screw leg screwed into the female screw hole 8. 15 and a plug portion 16 integrally projecting upward from the flange portion 13.
The plug portion 16 includes a tapered portion 19 having a tapered outer peripheral surface 18 that narrows upward (in the distal direction), and a male screw portion 20. The tapered portion 19 and the male screw portion 20 are provided in this order upward. .

A nut-like drive member 22 can be inserted into the circular hole 4 of the work pallet 2, and a female screw 23 of the drive member 22 is screwed into the male screw portion 20 so as to be movable in the axial direction (vertical direction). Combined. An output portion 24 is provided at the lower outer periphery of the drive member 22, and an inner protrusion 26 and an inner peripheral groove 27 projecting inward in the radial direction are provided upward at the lower end (base end) of the output portion 24. It is provided in order.
The annular collet 29 includes a slit 30 for allowing expansion and contraction in the diametrical direction, a straight outer peripheral surface 31 capable of contacting the inner peripheral surface of the circular hole 4, and an upper side of the tapered outer peripheral surface 18 ( And a taper inner peripheral surface 32 that performs taper engagement from the front end side.

  In the use state of FIG. 2, the lower end surface (base end surface) 26 a of the inner protrusion 26 is lower (base end side) than the upper end surface (tip end surface) 16 a of the plug portion 16 and above the tapered portion 19. It arrange | positions below the end surface (front end surface) 19a (base end side). Accordingly, the outer peripheral upper portion of the tapered portion 19 is covered by the lower outer peripheral portion of the output portion 24 of the driving member 22. For this reason, foreign matter in the atmosphere can be prevented from biting between the tapered outer peripheral surface 18 and the tapered inner peripheral surface 32.

An outer peripheral groove 35 that fits into the inner protrusion 26 and an outer protrusion 36 that protrudes outward in the radial direction so as to fit into the inner peripheral groove 27 at the upper end (tip) of the collet 29. Are provided in an upward order.
Further, the radially inner portion of the rotation prevention pin 38 is fixed to the taper portion 19, and the radially outer end portion of the pin 38 is fitted into the slit 30. Thereby, the collet 29 is prevented from rotating.
A hexagon hole 41 into which the hexagon wrench 40 is inserted is formed in the upper part of the drive member 22. A disk member 42 is fitted below the hexagonal hole 41. The disk member 42 prevents foreign matter in the atmosphere from entering the drive member 22 through the hexagonal hole 41.

The above positioning device is used as follows, for example.
In the unused state of FIG. 1A, the drive member 22 rises with respect to the male screw portion 20, the collet 29 is reduced in diameter by its own elastic restoring force, and the tapered inner peripheral surface 32 of the collet 29 and the A large gap is formed between the tapered outer peripheral surface 18.
At the time of use, the clamp 3 is switched from the state shown in FIG. 1A to the released state shown in the left half of FIG. 2, and the workpiece pallet 2 is lowered with respect to the reference member 1 in the released state. The hole 4 and the drive member 22 and the collet 29 are fitted with a predetermined radial gap, and the supported surface 2 a of the work pallet 2 is received by the support surface 11 of the boss 10.

Next, the nut-shaped drive member 22 is tightened and rotated by the hexagon wrench 40, and the drive member 22 is lowered with respect to the plug portion 16.
Then, the lower end surface (base end surface) 26a of the inner protrusion 26 pushes the collet 29 downward. Thereby, as shown in the locked state in the right half of FIG. 2, the collet 29 expands while descending along the tapered outer peripheral surface 18, and the straight outer peripheral surface 31 of the collet 29 has a circular hole 4. Is pressed in the radial direction (horizontal direction). Thereby, the work pallet 2 is positioned with respect to the plug portion 16 of the reference member 1. Subsequently, the work pallet 2 is pulled toward the reference member 1 through the collet 29 in close contact with the circular hole 4.
When the clamp 3 is switched from the locked state to the released state, the driving member 22 may be raised with respect to the plug portion 16 by loosening and rotating the driving member 22 with the hexagon wrench 40. As a result, as shown in the left half of FIG. 2, the inner protrusion 26 of the drive member 22 pushes up the collet 29 via the outer protrusion 36, and the collet 29 is reduced in diameter by its own elastic restoring force. It is.

The first embodiment (and each embodiment described later) has the following advantages.
In the released state shown in the left half of FIG. 2, the overlapping dimension in the radial direction between the inner protrusion 26 of the output portion 24 and the outer protrusion 36 of the collet 29 in the reduced diameter state is small. On the other hand, in the locked state shown in the right half of FIG. 2, the diameter of the collet 29 is increased. growing. For this reason, the contact area between the two is increased, and the collet 29 can be locked and driven in a strong and reliable manner.
Further, as shown in the left half of FIG. 2, in the reduced diameter state of the collet 29, it is easy to eliminate the radial step between the outer peripheral surface of the output portion 24 and the outer peripheral surface of the collet 29. Therefore, the circular hole 4 of the work pallet 2 and the collet 29 can be smoothly fitted.

FIG. 3 shows an example of a jig for incorporating the collet 29 into the output portion 24 of the drive member 22, and is a sectional view of the jig as seen from an elevation.
A tapered inner peripheral surface 52 that narrows downward is formed in the cylindrical hole of the annular housing 51, and the tapered outer peripheral surface 54 of the intermediate sleeve 53 is fitted to the tapered inner peripheral surface 52 from above. The collet 29 having a diameter reduced by its own elastic restoring force is inserted into the straight inner peripheral surface 55 of the intermediate sleeve 53. The intermediate sleeve 53 is made of a synthetic resin that is relatively hard and has a self-lubricating property. The nut-like drive member 22 is placed on the upper end surface of the collet 29.

When the intermediate sleeve 53 is lowered by the push-down cylinder 57, the collet 29 is forcibly reduced in diameter so that the gap of the slit 30 becomes almost zero via the intermediate sleeve 53. The outer diameter dimension of the protrusion 36 is smaller than the inner diameter dimension of the inner protrusion 26 of the output portion 24. As a result, the drive member 22 is lowered with respect to the collet 29 by its own weight or by a push-down force of a rod (not shown) inserted into the upper hole 58 of the push-down cylinder 57. The inner protrusion 26 and the outer peripheral groove 35 of the collet 29 face in the horizontal direction, and the inner peripheral groove 27 of the drive member 22 and the outer protrusion 36 of the collet 29 face in the horizontal direction. Thereafter, the intermediate sleeve 53 is raised by a push-up cylinder (not shown). Then, the diameter of the collet 29 is increased by its own elastic force, and the outer protrusion 36 of the collet 29 is fitted into the inner circumferential groove 27 of the driving member 22.
Thereby, the collet 29 is assembled to the driving member 22.

  FIGS. 4 to 6 show the second to fourth embodiments of the present invention, respectively, and are similar to FIG. 1A. In these other embodiments, the same members (or similar members) as the constituent members of the first embodiment will be described with the same reference numerals in principle.

The second embodiment in FIG. 4 differs from the first embodiment in the following points.
A female screw hole 61 is formed in the lower half of the housing 3a. The drive member 22 includes the output portion 24 provided at the upper portion and a bolt portion 62 provided at the lower half portion. The bolt part 62 is screwed into the female screw hole 61. The collet 29 is expanded in diameter by screwing the bolt 62 downward with a hexagon wrench 40.

In addition, a lower end surface (base end surface) 26 a of the inner protrusion 26 of the output portion 24 is disposed on the lower side (base end side) than the upper end surface (tip end surface) 16 a of the plug portion 16. This configuration is the same in each embodiment shown in FIGS.
With the above configuration, the outer peripheral upper portion of the plug portion 16 is covered by the lower peripheral portion of the output portion 24 of the drive member 22. For this reason, it can suppress that the foreign material in atmosphere bites between the taper outer peripheral surface 18 and the taper inner peripheral surface 32.
In addition, it is preferable that the outer end portion of the detent pin 38 is mounted so as to cover the slit 30 at the height position of the outer peripheral groove 35 of the collet 29. By configuring in this way, it is possible to reliably prevent foreign matter in the atmosphere from being caught between the tapered outer peripheral surface 18 and the tapered inner peripheral surface 32.

The third embodiment shown in FIG. 5 corresponds to a modification of the second embodiment shown in FIG. 4 as follows.
That is, the drive member 22 is constituted by a cylindrical member 65 having the output portion 24 and a bolt 66 inserted into a cylindrical hole of the cylindrical member 65. The bolt 66 is supported by the cylindrical member 65 so as to be rotatable around the axis and prevented from moving in the axis direction. The male screw leg of the bolt 66 is screwed into a female screw hole 61 provided in the upper half of the housing 3a.

The fourth embodiment shown in FIG. 6 differs from the above embodiments in the following points.
The plug portion 16 includes a cylindrical portion 71 provided on the upper portion of the housing 3a, and an intermediate collet 72 supported on the straight outer peripheral surface of the cylindrical portion 71 so as to be reciprocally movable in the vertical direction. The intermediate collet 72 includes a slit 73 and the tapered outer peripheral surface 18. The collet 29 is disposed outside the intermediate collet 72, and the tapered inner peripheral surface 32 of the outer collet 29 is engaged with the tapered outer peripheral surface 18 of the intermediate collet 72 from above.
The intermediate collet 72 is urged upward by an annular elastic member 76 and a ring 77. The intermediate collet 72 is prevented from moving upward by a predetermined amount by a retaining ring 78. The elastic member 76 is a synthetic resin here, but may be a disc spring or a coil spring.

The apparatus according to the fourth embodiment operates as follows.
When the rod 80 of the driving member 22 is driven downward, first, the outer collet 29 expands with respect to the intermediate collet 72 held at the raised position by the biasing force of the elastic member 76, and then the above-described elasticity is applied. The intermediate collet 72 and the outer collet 29 are lowered against the member 76. Thereby, the work pallet can be driven to descend strongly through the collet 29 in close contact with a circular hole (not shown) of the work pallet.

Each of the above embodiments can be modified as follows.
The reference member 1 may be a clamping jig or the like instead of the illustrated mechanical table or clamp pallet. Further, the movable member may be a work or a mold instead of the illustrated work pallet 2.
The collet clamp of the present invention is not limited to manual operation, and may be driven by a fluid actuator such as hydraulic pressure or pneumatic pressure, or may be driven by an electric motor or the like.

The collet 29 only needs to be configured to be able to expand and contract in the diameter direction, and it is needless to say that the collet 29 is not limited to the structure including one illustrated slit 30.
In the plug portion 16, when the tapered outer peripheral surface 18 is continuously formed in the circumferential direction, when three or more tapered outer peripheral surfaces 18 are formed at intervals in the circumferential direction, and a pair of tapered outer peripheral surfaces It can be considered that 18.18 are formed so as to face each other in the radial direction. The collet 29 has a pair of tapered inner peripheral surfaces 32 continuously formed in the circumferential direction, three or more tapered inner peripheral surfaces 32 formed at intervals in the circumferential direction, and a pair of It is conceivable that the tapered inner peripheral surfaces 32 and 32 are formed so as to face each other in the radial direction.

  FIG. 1A shows a first embodiment of the present invention, and is a sectional view of a collet clamp in an elevational view. FIG. 1B is a partial view of the right side view of FIG. 1A described above.   It is operation | movement explanatory drawing of the positioning apparatus using the said clamp, Comprising: The left half figure shows the release state, The right half figure has shown the locked state.   It is sectional drawing of an example of the jig | tool which incorporates a collet in the drive member of the said clamp, and shows the jig | tool.   It is a figure which shows 2nd Embodiment of this invention and is similar to said FIG. 1A.   It is a figure which shows 3rd Embodiment of this invention and is similar to said FIG. 1A.   It is a figure which shows 4th Embodiment of this invention and is similar to said FIG. 1A.

Explanation of symbols

1: reference member, 2: movable member (work pallet), 4: circular hole, 16: plug portion, 16a: tip surface (upper end surface), 18: tapered outer peripheral surface, 19: tapered portion, 19a: tip surface (upper) End face), 22: driving member, 24: output portion, 26: inner protrusion, 26a: proximal end face (lower end face), 27: inner peripheral groove, 29: collet, 30: slit, 31: straight outer peripheral face, 32: taper Inner peripheral surface, 35: outer peripheral groove, 36: outer protrusion.

Claims (4)

The plug portion (16) protruding from the reference member (1) in the distal direction is provided with a tapered outer peripheral surface (18) that narrows in the distal direction.
An output part (24) provided in the drive member (22) moved in the axial direction relative to the plug part (16), the output part being inserted into the circular hole (4) of the movable member (2) An inner protrusion (26) projecting radially inward and an inner circumferential groove (27) retreating radially outward are provided in the distal direction in the proximal end of (24),
A slit (30) for allowing expansion and contraction in the diameter direction, a straight outer peripheral surface (31) capable of contacting the inner peripheral surface of the circular hole (4), and a distal end side on the tapered outer peripheral surface (18) An outer peripheral groove (35) recessed inward in the radial direction so as to be fitted to the inner protrusion (26) at the tip of a collet (29) having a tapered inner peripheral surface (32) engaged from ) And an outer protrusion (36) protruding outward in the radial direction so as to fit in the inner circumferential groove (27), in order in the distal direction,
Collet type clamp characterized by that. The collet-type clamp of claim 1,
The collet type characterized in that the base end face (26a) of the inner protrusion (26) of the output portion (24) is arranged on the base end side of the front end face (16a) of the plug portion (16). Clamp. The collet-type clamp of claim 1,
The proximal end surface (26a) of the inner protrusion (26) of the output portion (24) is disposed closer to the proximal end than the distal end surface (19a) of the tapered portion (19) of the plug portion (16). Collet type clamp characterized by In the collet type clamp according to any one of claims 1 to 3,
In a state where the diameter of the collet (29) is forcibly reduced, the outer diameter of the outer protrusion (36) of the collet (29) is set to the inner protrusion (26) of the output section (24). A collet-type clamp characterized in that it is set to a value smaller than the inner diameter dimension of.

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