JP2005066758A - Collet chuck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a collet chuck which can easily connect and disconnect a clamping nut to a spring collet without using a mounting and dismounting tool, and is well balanced, and can be manufactured at a low cost. <P>SOLUTION: The spring collet 12 is engaged with a ring shape engaging portion 132 of the clamping nut 13 via a ring groove 122. Guide surfaces 124a, 124b are formed on both surfaces of the connecting flange portion 123 of the spring collet 12 in the thickness direction respectively, such that the thickness of a connecting flange portion 123 decreases with the radius of the connecting flange portion 123. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a collet chuck suitable for chucking a tool or a workpiece, and more particularly to a collet chuck having a spring collet and a clamping nut.

  As shown in FIG. 1, a collet chuck 1 for chucking a tool or a workpiece includes a spring collet 2 having a slit for gripping the tool or the workpiece, and a clamp for changing the spring collet 2 in the diameter reducing direction. A ping nut 3 is provided.

  As shown in FIG. 1, the spring collet 2 has a tapered portion 2a that is closely fitted in a tapered hole 4a provided in the main shaft or the tool halter body 4, and a large-diameter side end surface 2b of the tapered portion 2a A connecting flange 2d is formed concentrically from the end face 2b through a ring groove 2c having a desired width, and the connecting flange 2d and the ring groove 2c can rotate the spring collet 2 and the clamping nut 3 relative to each other. It is for connecting.

  As shown in FIG. 1, the clamping nut 3 has a female screw portion 3 a that is screwed into a male screw portion 4 b provided on the outer periphery of the main shaft or the tip end of the tool halter body 4 on the inner periphery thereof. An engagement portion 3b that engages with the ring groove 2c of the spring collet 2 so as to be relatively rotatable is formed in a ring shape on the inner periphery of the nut 3 at one end side.

  When the spring collet 2 is assembled to the clamping nut 3 in the collet chuck 1 having such a structure, the attachment / detachment tool 5 shown by the solid line in FIG. 1 is tapered as shown by the two-dot chain line in FIG. The spring collet 2 is maximally reduced in diameter by strongly fitting with the portion 2a.

  In this case, the outer diameter of the connecting collar 2d when the diameter of the spring collet 2 is reduced to the maximum is φD−ΔD, and the maximum reduced diameter of the connecting collar 2d and the inner diameter φd of the ring-shaped engaging portion 3b There is a relationship of φd ≧ φD−ΔD.

  Therefore, in a state where the diameter of the spring collet 2 is reduced to the maximum by the tool 5, the connecting collar 2 d is inserted into the ring-shaped engagement portion 3 b of the clamping nut 3, and then the tool 5 is tapered to the tapered portion 2 a of the spring collet 2. If removed, the spring collet 2 returns to its original diameter. Thereby, the engaging part 3b of the clamping nut 3 and the ring groove 2c of the spring collet 2 are engaged with each other, and the clamping nut 3 and the spring collet 2 can be connected to each other so as to be relatively rotatable.

Next, another example of a conventional collet chuck will be described with reference to FIGS.
2 and 3, the collet chuck 6 includes a spring collet 7 with a slit for gripping a tool or a workpiece, and a clamping nut 8 for changing the spring collet 7 in the diameter reducing direction.

  As shown in FIG. 2, the spring collet 7 has a taper portion 7a that is closely fitted in a taper hole 4a provided in the main shaft or the tool halter main body 4, and a large-diameter side outer peripheral surface of the taper portion 7a. A ring groove 7b is formed concentrically, and a tapered contact surface 7c that engages with the clamping nut 8 is formed on the large-diameter end surface of the tapered portion 7a.

  As shown in FIGS. 2 and 3, the clamping nut 8 has a female screw portion 8a that is screwed into a male screw portion 4b provided on the outer periphery of the main shaft or the tip end portion of the tool halter body 4 on the inner periphery thereof. A ring-shaped engaging portion 8 b that engages with the ring groove 7 b of the spring collet 7 so as to be relatively rotatable is formed eccentrically with respect to the axis of the clamping nut 8 on the inner periphery of the clamping nut 8. . Further, in order to eliminate the unbalance of the clamping nut 8 due to the eccentric formation of the ring-shaped engagement portion 8b, a plurality of balances are provided at a position opposite to the eccentricity of the ring-shaped engagement portion 8b. A hole 8c is formed.

In the collet chuck 6 having such a structure, when the spring collet 7 is assembled to the clamping nut 8, the tapered contact surface 7c is pressed against the ring-shaped engagement portion 8b of the clamping nut 8 from the female screw portion 8a side. By pushing the spring collet 7 toward the clamping nut 8, the ring groove 7 b of the spring collet 7 is engaged with the engaging portion 8 b of the clamping nut 8, and the clamping nut 8 and the spring collet 7 can be rotated relative to each other. Connect to
Design application 2002-013135 PCT / CH99 / 00394

  However, in the conventional collet chuck 1 as described above, the attachment / detachment tool 5 for reducing the diameter of the spring collet 2 is required for assembling the spring collet 2 to the clamping nut 3. In addition to increasing the height, there is a problem that it takes time and effort to attach and detach the detachable tool 5 to and from the spring collet 2.

  Further, in the conventional collet chuck 6 described above, the ring-shaped engagement portion 8b for engaging with the ring groove 7b of the spring collet 7 so as to be relatively rotatable is provided eccentrically. It is necessary to provide a balancing hole 8c for eliminating the balance at a position opposite to the eccentricity of the ring-shaped engaging portion 8b. As a result, the production of the clamping nut 8 becomes troublesome and the cost increases. There's a problem.

  According to a first aspect of the present invention, there is provided a spring collet with a slit for gripping a tool or a workpiece, and for gripping the tool or the workpiece by changing the spring collet in a diameter reducing direction. A collet chuck having a clamping nut that imparts a gripping force of the spring, wherein the spring collet has a tapered portion that is closely fitted in a tapered hole provided in a main shaft or a tool holder main body, and a large portion of the tapered portion. A ring groove for connecting to the clamping nut is formed concentrically on the outer peripheral surface of the diameter side, and a connecting flange for connecting to the clamping nut is formed concentrically on the tip of the large diameter side of the tapered portion. In addition, on both surfaces of the connecting collar portion in the thickness direction, there are guide surfaces that are inclined so that the thickness of the connecting collar portion decreases as going to the outer peripheral direction of the connecting collar portion, respectively. The clamping nut has a female screw portion that is screwed into a male screw portion provided on an outer periphery of a tip end portion of the main shaft or the tool halter body on an inner periphery thereof, and further includes an inner peripheral side on one end side of the clamping nut. An engaging portion that engages with the ring groove so as to be relatively rotatable is formed in a ring shape on the surface.

  According to a second aspect of the present invention, in the collet chuck according to the first aspect, when the spring collet is not reduced in diameter, the outer diameter of the connecting collar is φD1, and the outer diameter of the ring groove is φD2. The outer diameter φD1 of the connecting collar portion is larger than the inner diameter φd of the ring-shaped engagement portion, and the maximum diameter reduction allowance when the spring collet is reduced to the maximum is ΔD, and the spring collet Φd ≧ ((φD1-φD2) × 1/2 between the outer diameter of the connecting flange when the diameter is reduced to the maximum and the outer diameter of the ring groove and the inner diameter φd of the ring-shaped engagement portion ) -ΔD, and the outer diameter of the ring groove is set to be smaller than the inner diameter of the ring-shaped engaging portion.

  In the collet chuck of the present invention, guide surfaces are formed on both surfaces of the connecting collar portion in the thickness direction so as to be inclined in a direction in which the thickness of the connecting collar portion decreases as going to the outer peripheral direction of the connecting collar portion. Therefore, when attaching the spring collet to the clamping nut, the axis of the spring collet is slightly inclined with respect to the axis of the clamping nut, and one side of the connecting collar is inserted inside the ring-shaped engaging part. One side of the ring groove is engaged with the ring-shaped engagement portion. In such a state, if the outer peripheral portion of the spring collet opposite to the engagement side is pressed in the engagement side direction to reduce the diameter of the spring collet and press the entire spring collet against the ring-shaped engagement portion of the clamping nut, The ring groove fits into the ring-shaped engaging portion, and the clamping nut and the spring collet can be connected so as to be relatively rotatable.

  Also, when removing the spring collet from the clamping nut, press the spring collet in the side-by-side direction with the spring collet engaged with the ring-shaped engagement part of the clamping nut through the ring groove being moved to one side. To reduce the diameter of the spring collet. When the spring collet is pulled in such a state, the connecting collar of the spring collet is detached from the ring-shaped engaging portion of the clamping nut, and the spring collet can be separated from the clamping nut.

  Therefore, according to the collet chuck of the present invention, the clamping nut and the spring collet can be easily connected without using a detachable tool, and the spring collet and the clamping nut can be easily separated. In addition, since the clamping nut has a symmetrical shape, it is easy to manufacture the clamping nut, and it is possible to provide a collet chuck with good balance and low cost.

  In the best mode of the present invention, both sides in the thickness direction of the connecting collar of the spring collet engaged with the ring-shaped engaging part of the clamping nut via the ring groove are arranged in the outer peripheral direction of the connecting collar. By forming a guide surface that inclines in a direction in which the thickness of the connecting collar decreases as it goes, the clamping nut and the spring collet can be easily connected and separated without using a detachable tool. In addition, a well-balanced collet chuck can be obtained at low cost.

Next, examples of the collet chuck according to the present invention will be described.
4 is a longitudinal sectional view showing the overall configuration of the collet chuck in the first embodiment of the present invention, FIG. 5 is an enlarged view of a spring collet and a clamping nut constituting the collet chuck in the first embodiment of the present invention, FIG. FIG. 7 is an explanatory view of the operation of the collet chuck according to the first embodiment of the present invention.

  In FIG. 4, a collet chuck 10 has a spring collet 12 with a slit for gripping a tool or workpiece 11 and a tool or workpiece 11 by changing the spring collet 12 in the direction of diameter reduction. And a clamping nut 13 for imparting a gripping force.

  As shown in FIGS. 4 and 5, the spring collet 12 has a tapered portion 121 closely fitted in a tapered hole 141 provided in the main shaft or the tool halter main body 14, and the outer diameter side outer periphery of the tapered portion 121. A ring groove 122 for connecting to the clamping nut 13 is formed concentrically on the surface, and a connecting rod for connecting to the clamping nut 13 is connected to the tip of the tapered portion 121 on the large diameter side. The part 123 is formed concentrically. Further, guide surfaces 124 a and 124 b that are inclined in a direction of decreasing the thickness of the connecting collar 123 as it goes in the outer peripheral direction of the connecting collar 123 are formed on both surfaces of the connecting collar 123 in the thickness direction. Each is formed. The guide surfaces 124a and 124b function as a guide when the connecting collar 123 of the spring collet 12 is connected to the clamping nut 13 and separated from the clamping nut 13, and also has a function of facilitating the connection and separation. ing.

  As shown in FIGS. 4 and 5, the clamping nut 13 has a female screw portion 131 that is screwed into a male screw portion 142 provided on the outer periphery of the main shaft or the tip end portion of the tool holder main body 14 on the inner periphery thereof. . An engaging portion 132 that engages with the ring groove 122 so as to be relatively rotatable is formed in a ring shape on the inner peripheral surface of the clamping nut 13.

The outer diameter φD1 of the connecting collar when the outer diameter of the connecting collar 123 when the spring collet 12 is not reduced is φD1 and the outer diameter of the ring groove 122 is φD2 is shown in FIG. Thus, ΔD is the maximum diameter reduction allowance when the spring collet 12 has a diameter larger than the inner diameter φd of the ring-shaped engaging portion 132 and the spring collet 12 is contracted to the maximum, and the spring collet 12 is contracted to the maximum. Between the outer diameter of the connecting flange 123 and the outer diameter of the ring groove 122 and the inner diameter φd of the ring-shaped engaging portion 132 when being diametered,
φd ≧ ((φD1-φD2) × 1/2) −ΔD
The relationship is established. The outer diameter φD2 of the ring groove 122 is set to be smaller than the inner diameter φd of the ring-shaped engagement portion 132, and the groove width of the ring groove 122 is larger than the thickness of the connecting flange 123. Is set to

  In the collet chuck 10 configured as described above, when the spring collet 12 is mounted on the clamping nut 13, the axis L2 of the spring collet 12 is slightly set with respect to the axis L1 of the clamping nut 13, as shown in FIG. In this state, one side of the connecting collar 123 is inserted inside the ring-shaped engaging part 132. As a result, one side of the ring groove 122 is engaged with the ring-shaped engagement portion 132. Accordingly, in this state, the outer peripheral portion of the spring collet 12 opposite to the engagement side of the ring groove 122 is pressed in the engagement side direction indicated by the arrow A in FIG. When pressed in the direction indicated by the arrow B in FIG. 6 and pressed against the ring-shaped engagement portion 132 of the clamping nut 13, the guide surface 124b becomes a guide, and the ring groove 122 fits into the ring-shaped engagement portion 132, and clamping. The nut 13 and the spring collet 12 can be connected so as to be relatively rotatable.

  When removing the spring collet 12 from the clamping nut 13, as shown in FIG. 7, the spring collet 12 engaged with the ring-shaped engaging portion 132 of the clamping nut 13 via the ring groove 122 is moved to one side. In this state, the spring collet 12 is pressed in the side-shift direction indicated by the arrow C in FIG. In this state, when the spring collet 12 is pulled in the direction shown by the arrow D in FIG. 7, the guide surface 124 becomes a guide, and the connecting collar 123 of the spring collet 12 comes out of the ring-shaped engagement portion 132 of the clamping nut 13. The spring collet 12 can be separated from the clamping nut 13.

  Further, when the tool or workpiece 11 is chucked using the spring collet 12 and the clamping nut 13 connected as described above, the tool or workpiece is placed in the center hole of the spring collet 12, as shown in FIG. The workpiece 11 is inserted, and the clamping nut 13 is rotated in the tightening direction in which the main shaft or the male screw portion 142 of the tool halter body 14 is screwed. Thus, the diameter of the spring collet 12 is reduced by pushing the spring collet 12 connected via the ring-shaped engagement portion 132 and the ring groove 122 into the main shaft or the tool halter main body 14 into the tapered hole 141. As a result, the tool or workpiece 11 inserted into the center hole of the spring collet 12 is chucked.

  According to the collet chuck 10 shown in the first embodiment of the present invention, the connecting collar 123 of the spring collet 12 engaged with the ring-shaped engaging portion 132 of the clamping nut 13 via the ring groove 122. Since the guide surfaces 124a and 124b that are inclined in the direction in which the thickness of the connecting collar 123 decreases as it goes in the outer peripheral direction of the connecting collar 123 are formed on both surfaces in the thickness direction, respectively, The clamping nut 12 and the spring collet 13 can be easily connected to each other without using a special attaching / detaching tool, and the spring collet 12 and the clamping nut 13 can be easily separated. The clamping nut 13 has a symmetrical shape and does not require a balancing process as in the prior art. Therefore, the clamping nut 13 can be easily manufactured, and the collet chuck is well balanced and low cost. 10 can be provided.

It is sectional drawing for description of the conventional collet chuck. It is sectional drawing for description which shows the other example of the collet chuck in the past. It is sectional drawing which follows the 3-3 line of FIG. It is a longitudinal cross-sectional view which shows the whole structure of the collet chuck in Example 1 of this invention. It is an enlarged view of the spring collet and clamping nut which comprise the collet chuck in Example 1 of this invention. It is operation | movement explanatory drawing of the collet chuck in Example 1 of this invention. It is operation | movement explanatory drawing of the collet chuck in Example 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Collet chuck 11 Tool or workpiece 12 Spring collet 121 Tapered part 122 Ring groove 123 Coupling part 124a, 124b Guide surface 13 Clamping nut 131 Female thread part 132 Ring-shaped engaging part 14 Spindle or tool halter main body 141 Tapered hole 142 Male thread

Claims (2)

A spring collet with a slit for gripping a tool or a workpiece, and a clamping nut for applying a gripping force for gripping the tool or the workpiece by changing the spring collet in the diameter reducing direction A collet chuck,
The spring collet has a tapered portion that is closely fitted in a tapered hole provided in a main shaft or a tool halter body, and a ring groove for connecting to the clamping nut is formed on the outer peripheral surface of the tapered portion on the large diameter side. Concentrically formed, concentric hooks for connecting with the clamping nut are formed concentrically at the tip of the tapered portion on the large diameter side, and both sides of the connecting hook in the thickness direction are connected to each other. A guide surface that is inclined in a direction in which the thickness of the connecting hook part decreases as it goes in the outer peripheral direction of the hook part is formed,
The clamping nut has a female thread portion that is threadedly engaged with a male thread portion provided on the outer periphery of the main shaft or the tip end portion of the tool halter body on the inner periphery thereof, and the ring is formed on the inner peripheral surface on one end side of the clamping nut. A collet chuck characterized in that an engaging portion that engages with a groove so as to be relatively rotatable is formed in a ring shape. The outer diameter φD1 of the connecting collar when the outer diameter of the connecting collar when the diameter of the spring collet is not reduced is φD1 and the outer diameter of the ring groove is φD2. ΔD is a maximum diameter reduction allowance when the diameter of the spring collet is reduced to the maximum, and the outer diameter of the connecting collar when the spring collet is reduced to the maximum is presented. The ring and the outer diameter of the ring groove and the inner diameter φd of the ring-shaped engaging portion are configured so that a relationship of φd ≧ ((φD1-φD2) × 1/2) −ΔD is established, and the ring The collet chuck according to claim 1, wherein an outer diameter of the groove is set to be smaller than an inner diameter of the ring-shaped engaging portion.

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