JP2004025349A - Inside diameter collet chuck - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inside diameter collet chuck capable of preventing the twisting of a collet when working a large torque to a matter to be held. <P>SOLUTION: This inside diameter collet chuck 1 comprises the collet 5 formed to be radially expansible and contractible to hold the matter to be held at the tip, and a regulating frame body 3 fitted to the circumference of the collet. The regulating frame body has four protruding parts 35, and the collet has four grooves 41 to be fitted to the corresponding protruding parts. Each protruding part and each groove are extended in the axial direction from the regulating frame body and the tip of the collet. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inner diameter collet chuck.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, when a member having a hole, such as an annular member, is held, there is an inner diameter collet chuck as a means for holding the member from the inner surface of the hole, and an example thereof has been disclosed in JP-A-8-19909. There is something. The inner diameter collet chuck mainly includes a cylindrical collet whose leading end outer peripheral surface is in contact with an inner surface of a hole such as a ring, an expander fitted inside the collet, and a regulating frame body that regulates expansion of the collet. . The collet and the expander have a pair of frusto-conical surfaces that are in surface contact with each other.
[0003]
In such an inner diameter collet chuck, when an annular object is set on the outer peripheral surface of the leading end of the collet before being enlarged, and the expander is slid in the axial direction with respect to the collet, the collet is formed by the action of the truncated conical surface. Is expanded radially outward, and an object to be held such as an annular object set on the outer peripheral surface of the tip of the collet can be held from the inner surface side of the hole. Further, since the expansion of the collet is restricted by the regulating frame, the collet does not expand too much and holds the object to be held with a suitable holding force.
[0004]
[Problems to be solved by the invention]
When a large torque is applied to an object held by the inner diameter collet chuck, for example, in a so-called friction welding process, a sufficient strength is required for the collet itself. However, since the collet is made of spring steel in order to secure the function of the collet that expands and contracts in accordance with holding and releasing, it has been difficult to increase the rigidity. Further, as shown in FIG. 1 of the above-mentioned publication, a configuration in which a detent pin is provided on the collet can be seen, but such a configuration causes the collet to rotate while the collet is being enlarged or reduced. If the collet in the enlarged state holding the object to be held receives a large torque, there is a possibility that the portion on the front side (right side in FIG. 1 of the above publication) with respect to the collet stopper may be twisted. .
[0005]
Accordingly, an object of the present invention is to provide an inner diameter collet chuck that can prevent the collet from being twisted even when a large torque such as friction welding acts on an object to be held.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, an inner diameter collet chuck of the present invention is formed so as to be able to expand and contract in a radial direction, and is fitted to a cylindrical collet holding an object to be held at a distal end portion, and to an outer periphery of the collet. A frame, wherein the frame has one of a concave portion and a convex portion fitted with the concave portion, and the collet has the other of the concave portion and the convex portion integrally provided, and the concave portion and the convex portion are provided integrally. The part is arranged at least in the immediate vicinity of the held object.
Further, the frame is fitted around the outer periphery of the collet, the held object is held at the outer periphery of the collet exposed from the front end of the frame, and the one of the concave portion and the convex portion is It is preferable to extend from the front end of the frame. Further, it is preferable that the concave portion and the convex portion extend along an axial direction of the corresponding collet and the frame. Further, the projection may be provided on the frame, and the recess may be provided on the collet. Further, a plurality of the concave portions and the convex portions may be provided.
[0007]
In order to achieve the above object, an inner diameter collet chuck of the present invention is formed so as to be able to expand and contract in a radial direction, and has a cylindrical collet holding an object to be held at a distal end thereof, and a frame fitted to an outer periphery of the collet. And the frame and the collet are provided integrally with recesses, and keys are provided that fit into these recesses.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The front-rear direction in the description will be described with the side on which an object to be held is set, that is, the left direction in FIG. The inner diameter collet chuck 1 includes housings A and B, a regulating frame 3, a collet 5, and an expander 7. The housing A is a cylindrical member as a whole, and a cylinder portion 9 having a larger diameter than the rear half portion is provided in the front half portion. A housing B is attached to the open front end of the cylinder portion 9 by bolts 11. The housing B is a disk-shaped member having a hole 13 formed in the center. A cylindrical regulating frame 3 is attached to the front surface of the housing B by bolts 15. Further, a cylindrical collet 5 is arranged inside the regulating frame 3. Although the collet 5 can be enlarged or reduced in the radial direction, the expansion of the collet 5 is suppressed to a fixed amount by the regulating frame 3.
[0009]
An expander 7 is provided inside the collet 5, the regulating frame 3, the housing B, and the cylinder portion 9 so as to be slidable in the front-rear direction. An enlarged diameter portion 17 is formed at a front portion of the expander 7, and a piston portion 19 is formed at a rear portion of the expander 7. The enlarged diameter portion 17 has a truncated cone-shaped outer peripheral surface (hereinafter, referred to as a “truncated cone surface”) 17a whose outer diameter increases toward the front. The inner peripheral surface of the collet 5 is also formed in a frusto-conical shape corresponding to the frusto-conical surface 17 a of the enlarged diameter portion 17. A frustoconical inner peripheral surface (hereinafter, referred to as a “frustoconical surface”) 5a of the collet 5 is formed such that the hole diameter increases toward the front.
[0010]
The piston section 19 of the expander 7 is housed in a cylindrical space defined by the cylinder section 9 and the housing B. A pressure receiving chamber 21 into which a coolant to be described later is introduced is defined behind the piston 19, and a spring accommodating chamber 23 is defined ahead of the piston 19. A coil spring 25 is housed in the spring housing 23. The front end of the coil spring 25 is in contact with the housing B, and the rear end of the coil spring 25 is in contact with the piston portion 19.
[0011]
The details of the regulating frame 3 and the collet 5 will be described with reference to FIGS. The regulating frame 3 is a cylindrical member as a whole, and a flange portion 31 having a larger diameter than a front portion is formed at a rear portion thereof. The regulating frame 3 is connected to the housing B by the above-described bolt 15 at the flange portion 31. A hole 33 for accommodating the collet 5 is formed in the center of the regulating frame 3. Four projections 35 are formed on the inner surface of the hole 33, each projecting radially inward. Each protruding portion 35 is disposed so as to be 90 degrees apart from the adjacent protruding portion 35, and extends from the tip 3 a of the regulating frame 3 in the axial direction of the regulating frame 3.
[0012]
The collet 5 is a cylindrical member as a whole having a hole formed in the center. The collet 5 has a main body 37 at the front, and a flange 39 having a larger diameter than the front at the rear. The inner surface of the hole at the center of the collet is formed as the truncated conical surface 5a as described above. The outer peripheral surface of the collet 5 extends from the front end to the rear end of the collet 5 in the axial direction of the collet 5, that is, extends from the outer peripheral surface of the main body 37 to the outer peripheral surface of the flange 39. Four grooves 41 are formed. Each groove 41 has such a shape as to be fitted with the above-mentioned protruding portion 35, and is arranged so as to be 90 degrees apart from another adjacent groove 41. The flange 39 is separated into four independent portions 39a to 39d by four grooves 41. Further, the collet 5 is formed with eight cuts 43a to 43h for assisting the enlargement and reduction of the collet. Of these, the four cuts 43 a to 43 d are formed at the bottom of the corresponding groove 41, start from the front end of the main body 37, and end before the flange 39. On the other hand, the other four cuts 43 e to 43 h are formed in the middle (the middle in the circumferential direction of the collet) of the corresponding pair of grooves 41, that is, in the part without the grooves 41, starting from the rear end of the flange 39. It ends before the front end of the main body 37. That is, the cuts 43a to 43d and the cuts 43e to 43h are formed at positions separated from each other by 45 degrees in the circumferential direction, and formed so that the cut directions are alternated. In addition, the side surface 41a of each groove 41 extends substantially in parallel with the surface including the pair of cuts 43a and 43c and the pair of cuts 43b and 43d (the side surface 35a of each protrusion 35 corresponding to the side surface 41a is also included). Also the same).
[0013]
Next, an operation when the inner diameter collet chuck 1 configured as described above is applied to friction welding of a valve seat of an engine will be described. First, in the released state of the inner diameter collet chuck 1, a coolant is introduced into the pressure receiving chamber 21, and the expander 7 resists the elastic force of the coil spring 25 due to the fluid pressure of the coolant acting on the piston portion 19, and the forward pressure is increased. Has been energized. Due to the forward biasing of the expander 7, the smaller-diameter portion of the frusto-conical surface 17a of the enlarged diameter portion 17 comes into contact with the frusto-conical surface 5a of the collet 5, whereby the collet 5 is in the contracted released state. Is maintained. In this release state, the valve seat 45 as an object to be held is set outside the exposed outer peripheral portion 5b of the collet 5 which projects forward from the front end 3a of the regulating frame 3 and is exposed. After the setting, the collet 5 is enlarged and brought into a gripping state. First, the coolant is discharged from the pressure receiving chamber 21. Thereby, the expander 7 slides backward by the elastic force of the coil spring 25 acting on the piston portion 19. The rearward movement of the expander 7 causes the larger diameter portion of the truncated conical surface 17 a of the enlarged diameter portion 17 to abut on the truncated conical surface 5 a of the collet 5. As a result, the collet 5 expands and holds the valve seat 45 disposed on the outer periphery from the inside of the hole.
[0014]
Next, in a state where the valve seat 45 is firmly held by the inner diameter collet chuck 1, the rear half of the inner diameter collet chuck 1 is attached to a rotating device (not shown) such as a machining center, and is fixed on a table while rotating with a large torque. The valve seat 45 is rubbed against a cylinder head (not shown) as a member to be pressed. As a result, the two members are firmly joined by the heating / compression bonding phenomenon that occurs between the valve seat 45 and the cylinder head. At this time, the valve seat 45 and the collet 5 gripping it receive a large torque from the cylinder head due to frictional force. Such a torque was difficult to receive with a conventional inner diameter collet chuck. However, in the inner diameter collet chuck 1 according to the present invention, the conventional inner diameter is formed by integrally forming the groove 41 and the protrusion 35 connecting the collet 5 and the regulating frame 3 with the collet 5 and the regulating frame 3, respectively. As compared with the position where the collet and the regulating frame are connected by the stopper in the collet chuck, the collet 5 and the regulating frame 3 can be connected at a position closer to the valve seat 45, which is accompanied by friction welding. Even if an excessive torque acts on the collet 5, it is possible to prevent the collet 5 from being twisted due to the excessive torque. Further, since the groove 41 and the protrusion 35 formed in the collet 5 and the regulating frame 3 are secured at the tip 3a of the regulating frame 3, the torsion of the collet 5 can be further prevented. Further, since the groove 41 and the protrusion 35 extend in the axial direction of the collet 5 and the regulating frame 3, respectively, the torque applied to the groove 41 and the protrusion 35 is applied in the axial direction of the groove 41 and the protrusion 35. The grooves 41 and the protrusions 35 can be prevented from being deformed. Further, since a plurality of grooves (four in this embodiment) and a plurality of protrusions 35 are formed in the collet 5 and the regulating frame 3, the torque applied to the groove 41 and the protrusion 35 is further dispersed. be able to.
[0015]
Note that the inner diameter collet chuck of the present invention is not limited to the above-described embodiment, and various modifications can be made.
For example, the projection is not limited to the mode in which the protrusion is provided in the regulating frame and the groove is provided in the collet as described above, and a mode in which a groove is provided in the regulating frame and the projection is provided in the collet may be employed. Further, the shapes and numbers of the protruding portions and the regulating frames are not limited to the above-described embodiment, but can be appropriately modified.
In addition, notches do not necessarily need to be arranged in the grooves, and all cuts may be located at positions off the grooves.
In addition, instead of the protrusions and grooves formed integrally with the regulating frame or the collet, concave portions facing each other are provided on the regulating frame and the collet, and both spaces are defined in the space defined by these concave portions. The key may be inserted into the concave portion and inserted so as to protrude and extend further from the tip of the regulating frame. Specifically, as shown in FIGS. 5A and 5B, concave portions 141 and 135 are provided in both the collet 105 and the regulating frame 103, and are fitted in both concave portions and the regulating frame is provided. A key 235 extending further from the tip of the body 103 may be used. Similarly, when the regulating frame and the collet are integrally provided with the concave portion and the convex portion, the concave portion or the convex portion may be formed to have a shape further extending from the distal end portion of the regulating frame.
Further, the force for releasing and holding the collet is not limited to the use of the fluid pressure and the elastic force, and the fluid pressure, the elastic force, the electromagnetic force, and other driving forces may be used alone or in combination. It can be used in combination. Further, the moving direction of the expander and the releasing operation and the gripping operation of the collet are not limited to the above-described embodiment. Therefore, the collet expands when the expander moves forward and contracts when moving backward. It may be a mode of doing. In addition, the expansion of the collet is not limited to the expansion using the expander having the truncated conical surface.
The object to be held is not limited to the valve seat, but is not limited to an annular object. Therefore, the object to be held may be a member having a hole (including a recess that does not penetrate) regardless of its outer shape. Further, the holding of the held object is not limited to the holding in the friction welding step, but can be widely applied to the holding in a mode in which an excessive torque acts.
[0016]
【The invention's effect】
As described above, according to the inner diameter collet chuck of the present invention, it is possible to prevent the collet from being twisted even when an excessive torque acts on the held object.
[Brief description of the drawings]
FIG. 1 is a side view including a partial cross section of an inner diameter collet chuck according to an embodiment of the present invention.
FIG. 2 is a perspective view of a regulating frame constituting the inner diameter collet chuck.
FIG. 3 is a perspective view of a collet constituting the inner diameter collet chuck.
FIG. 4 is a perspective view showing a fitting state of a regulating frame and a collet via a protrusion and a groove.
FIG. 5A is a perspective view showing a fitting state of a regulating frame and a collet via a pair of recesses and a key, and FIG. 5B is a diagram showing the key alone.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Inside diameter collet chuck, 3,103 ... Restriction frame, 5, 105 ... Collet, 35 ... Projection (convex), 41 ... Groove (concave), 45 ... Valve seat (holding object), 135, 141 ... Recess, 235 ... key.

Claims (6)

A cylindrical collet formed to be scalable in the radial direction and holding the object to be held at the tip,
A frame fitted to the outer periphery of the collet,
One of the concave portion and the convex portion fitted with the concave portion is integrally provided on the frame body, and the other of the concave portion and the convex portion is integrally provided on the collet,
An inner diameter collet chuck in which the concave portion and the convex portion are arranged at least in the vicinity of the held object. The frame is fitted on the outer periphery of the collet, the held object is held on the outer periphery of the collet exposed from the tip of the frame, and the one of the concave portion and the convex portion is the frame body. The inner diameter collet chuck according to claim 1, wherein the inner diameter collet chuck extends from an end of the collet. The inner diameter collet chuck according to claim 1, wherein the concave portion and the convex portion extend along an axial direction of the corresponding collet and the frame body. 4. 4. The inner diameter collet chuck according to claim 1, wherein the protrusion is provided on the frame body, and the recess is provided on the collet. 5. The inner diameter collet chuck according to claim 1, wherein a plurality of the concave portions and the convex portions are provided. A cylindrical collet formed to be scalable in the radial direction and holding the object to be held at the tip,
A frame fitted to the outer periphery of the collet,
An inner diameter collet chuck in which a concave portion is integrally provided in each of the frame body and the collet, and a key that fits into each of the concave portions is provided.

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