JP2020171999A - Clamp device - Google Patents

Abstract

To provide a clamp device configured simply.SOLUTION: A plurality of collet members 410 are arranged in parallel along a circumferential direction at an outer periphery side of a shaft member-outer peripheral surface portion 312c of a shaft member 310. Each of the collet members 410 has a collet member-inner peripheral surface portion 411b, a collet member-inner peripheral surface portion 411a, whose extending direction along a shaft direction inclines at an inclination angle θ with respect to an extending direction along the shaft direction of the collet member-inner peripheral surface portion 411b, and a protruding part 413A that can be inserted into a recessed part 613 provided in a member 610 to be clamped. When an operating member 320 is not pressed against a tip side, a clamp device is set in a clamp mode in which the collet member-inner peripheral surface portion 411b approaches the shaft member-outer peripheral surface portion 312c by elastic force of an annular spring 420 and the protruding part 413A moves outward in a radial direction. When the operating member 320 is pushed toward the tip side, the device is set in an unclamp mode in which the collet member-inner peripheral surface portion 411a approaches the shaft member-outer peripheral surface portion 312c against the elastic force of the annular spring 420 and the protruding part 413A moves inward in the radial direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a clamping device that clamps a member to be clamped.

A clamping device is used to clamp (hold) a member to be clamped such as a tool holder that holds a tool. Such a clamp device is disclosed in, for example, Patent Document 1 (Japanese Unexamined Patent Publication No. 2017-104974).
The clamp device disclosed in Patent Document 1 includes a main body portion having an inner peripheral surface of the main body portion extending along the axial direction and forming an inner space of the main body portion having an opening on the tip side, a collet, and a first. It has one part and a second part.
The collets are arranged side by side in the inner space of the main body along the circumferential direction, and have a plurality of collet members extending along the circumferential direction and the axial direction. The outer peripheral surface of the collet member of each collet member includes a first outer surface and a second outer surface. The first outer surface is formed so as to be able to come into contact with the inner surface of the shank portion included in the inner peripheral surface of the shank portion of the shank portion of the tool holder, which is inserted into the inner space of the main body portion. Further, the second outer surface is formed so as to be engageable with the inner surface of the main body portion included in the inner peripheral surface of the main body portion. The first component and the second component are arranged inside the collet so as to be relatively movable along the axial direction.
The clamp device disclosed in Patent Document 1 operates as follows. When the first component and the second component are brought close to each other along the axial direction, each collet member is pressed outward in the radial direction. As a result, the first outer surface of each collet member comes into contact with the inner surface of the shank portion of the tool holder, and the second outer surface comes into contact with the inner surface of the main body portion included in the inner peripheral surface of the main body portion, so that the tool holder becomes the main body portion. Retained (clamp mode). On the other hand, when the first component and the second component are separated from each other along the axial direction, the pressing of each collet member inward in the radial direction is released. As a result, the contact between the first outer surface of each collet member and the inner surface of the shank portion of the tool holder and the contact between the second outer surface and the inner surface of the main body portion are released, and the tool holder can be attached and detached (unclamp mode). ..

JP-A-2017-104974

In the conventional clamping device, the clamped member is clamped by pressing each collet member constituting the collet radially outward (clamp mode), and the clamped member is released by releasing the pressing radially outward. It is set to a removable state (unclamp mode). Therefore, the configuration of the clamp device is complicated.
The present invention has been devised in view of such a point, and an object of the present invention is to provide a clamp device having a simple structure.

The clamp device of the present invention has a shank portion that extends along the axial direction and is provided with a shank portion inner space having an opening on one end side, and an inner peripheral surface of the shank portion that forms the shank portion inner space. It is used when clamping a member to be clamped, which is provided with a recess. Preferably, the recess provided on the inner peripheral surface of the shank portion is composed of a groove extending along the circumferential direction.
The present invention includes a main body, a shaft member, a collet, a first elastic member, an operating member, and a pushing force generating mechanism.
The main body has an inner peripheral surface of the main body that extends along the axial direction and forms an inner space of the main body that is open at the tip side. Preferably, the center line of the space inside the main body extends in parallel with the axial direction (including "substantially parallel").
The shaft member is arranged in the space inside the main body portion, and has a shaft member outer peripheral surface including a shaft member outer peripheral surface portion extending along the axial direction. Preferably, the outer peripheral surface portion of the shaft member extends parallel to the axial direction (including "substantially parallel").
The collet has a plurality of collet members arranged side by side along the circumferential direction on the outer peripheral side of the outer peripheral surface portion of the shaft member of the shaft member. The number of collet members can be set as appropriate.
Each collet member extends in the circumferential direction and the axial direction along the outer peripheral surface portion of the shaft member of the shaft member, and has a collet member inner peripheral surface on the inner peripheral side (the side facing the outer peripheral surface portion of the shaft member). The collet member outer peripheral surface is provided on the outer peripheral side (the side opposite to the shaft member outer peripheral surface portion). Preferably, each collet member has a collet member front end surface on the front end side, a collet member rear end surface on the rear end side, and a collet member side surface on one side in the circumferential direction and the other side in the circumferential direction. Further, each collet member is provided with a first protrusion protruding on the side opposite to the inner peripheral surface of the collet. The first protrusion is formed so as to be insertable into a recess provided on the inner peripheral surface of the shank portion of the member to be clamped. The first protrusion is preferably provided on the tip end side of the collet member.
The inner peripheral surface of the collet member is formed on the tip side of the first inner peripheral surface portion and the first inner peripheral surface portion, and the extending direction along the axial direction is the first when viewed in a cross section along the axial direction. The second inner peripheral surface portion that is inclined at an inclination angle θ with respect to the extending direction along the axial direction of the inner peripheral surface portion is included. The inclination angle θ is represented by an angle defined by the first inner peripheral surface portion and the second inner peripheral surface portion. For example, the angle defined by the line extending the extending line along the axial direction of the first inner peripheral surface portion toward the tip side and the extending line along the axial direction of the second inner peripheral surface portion, or the first inner peripheral surface. It can be represented by an angle defined by an extending line along the axial direction of the portion and an extending line along the axial direction of the second inner peripheral surface portion. The inclination angle θ is a state in which the extending direction along the axial direction of the first inner peripheral surface portion is parallel to the extending direction along the axial direction of the outer peripheral surface portion of the shaft member (including “substantially parallel”). The distance between the second inner peripheral surface portion and the outer peripheral surface portion of the shaft member is set so as to widen from the rear end side to the front end side.
The elastic force of the first elastic member is configured to act as a force that brings the first inner peripheral surface portion of each collet member closer to the outer peripheral surface portion of the shaft member. Preferably, the first elastic member is formed of an annular spring and is arranged at a location on the outer peripheral surface of the collet member corresponding to the first inner peripheral surface portion of each collet member arranged side by side in the circumferential direction. To.
The operating member is composed of a tubular member, and is arranged on the outer peripheral side of the shaft member, on the rear end side of the collet, so as to be movable along the axial direction with respect to the shaft member.
The pushing force generating mechanism is configured to be able to generate a pushing force that pushes the operating member toward the tip end side with respect to the shaft member. The pushing force generating mechanism may be composed of one or a plurality of components as long as it can generate a pushing force for pushing the operating member toward the tip end side.
When the operating member moves to the tip side by the pushing force generated from the pushing force generating mechanism, the operating member abuts on each collet member and pushes the rear end portion of each collet member, and the second inner peripheral surface portion of each collet member. Approaches the outer peripheral surface of the shaft member. Preferably, the force by which the operating member pushes the rear end portion of each collet member separates the first outer peripheral surface portion of each collet member from the outer peripheral surface portion of the shaft member, and the second inner peripheral surface portion becomes the outer peripheral surface portion of the shaft member. It is configured to act as an approaching force.
Then, by generating an extrusion force from the extrusion force generation mechanism, the operating member abuts on each collet member and pushes each collet member, resisting the elastic force of the first elastic member, and inside the second of each collet member. The first elastic member is set to an unclamp mode in which the peripheral surface portion approaches the outer peripheral surface portion of the shaft member and the first protrusion moves inward in the radial direction, and the generation of the extrusion force from the extrusion force generation mechanism is stopped. The elastic force of each collet member is configured to be set to a clamp mode in which the first inner peripheral surface portion of each collet member approaches the outer peripheral surface portion of the shaft member and the first protrusion portion moves outward in the radial direction.
In the present invention, collets are arranged side by side along the circumferential direction on the outer peripheral side of the outer peripheral surface portion of the shaft member, and the first inner peripheral surface portion and the extending direction along the axial direction are the first inner peripheral surface portion. It is composed of a plurality of collet members having an inner peripheral surface of a collet member including a second inner peripheral surface portion inclined at an inclination angle θ with respect to the extending direction along the axial direction, and the first inner circumference of each collet member. The clamp mode is set by bringing the surface portion closer to the outer peripheral surface of the shaft member, and the unclamp mode is set by bringing the second inner peripheral surface portion of each collet member closer to the outer peripheral surface portion of the shaft member. This makes it possible to easily configure the clamp device.
In a different embodiment of the present invention, the inclination angle θ is set so that the first protrusion can be inserted into the space inside the shank portion of the member to be clamped in the state of being set to the unclamp mode. Specifically, the maximum outer diameter H of the plurality of first protrusions in the state of being set to the unclamp mode is set to be smaller than the inner diameter D of the space inside the shank portion (D> H).
In the present embodiment, the first protrusion provided on each collet member can be easily inserted into the recess provided on the inner peripheral surface of the shank portion forming the inner space of the shank portion of the member to be clamped.
In a different embodiment of the present invention, each collet member has a second protrusion protruding from the rear end side of the first protrusion to the side opposite to the inner peripheral surface of the collet member. Then, the operating member is configured to come into contact with the second protrusion of each collet member and push the second protrusion to set the unclamp mode. Preferably, due to the contact between the operating member moving to the tip side and the second protrusion of each collet member, a force for moving the second protrusion to the tip side and radially outward acts on each collet member. , The shape and position of the contact point between the operating member and the second protrusion are set.
In this embodiment, the unclamp mode can be easily set.
In a different embodiment of the present invention, the inner peripheral surface of the main body portion includes an inner peripheral surface portion of the main body portion that is arranged between the first protrusion and the second protrusion of each collet member and protrudes inward in the radial direction. Then, the operating member abuts on the second protrusion of each collet member and pushes the second protrusion to enter the unclamp mode in a state where the second protrusion is in contact with the inner peripheral surface portion of the main body. It is configured to be set.
In this embodiment, the unclamp mode can be set more easily.
In a different embodiment of the present invention, a second elastic member that generates an elastic force that moves each collet member toward the tip end side with respect to the operating member is provided. As the second elastic member, a spring provided between each collet member and the operating member is preferably used.
In this embodiment, each collet member is given a force by the elastic force of the second elastic member to move the second protrusion in the direction of contacting the inner peripheral surface portion of the main body portion protruding inward in the radial direction. , Can be set to unclamp mode more easily.
In a different embodiment of the present invention, the shaft member is arranged so as to be movable along the axial direction with respect to the main body portion, and generates an elastic force for moving the shaft member toward the rear end side with respect to the main body portion. 3 Elastic members are provided. Further, the shaft member has a third protrusion protruding from the outer peripheral surface portion of the shaft member on the tip end side of the outer peripheral surface portion of the shaft member. Further, by generating the pushing force from the pushing force generating mechanism, the elastic force of the third elastic member is prevented from being transmitted to the shaft member, and the shaft member is pushed out to the tip side. ..
Then, by stopping the generation of the pushing force from the pushing force generating mechanism, the shaft member moves to the rear end side by the elastic force of the third elastic member, and a part of the second inner peripheral surface portion of each collet member is removed. The clamp mode is set in a state of being in contact with the third protrusion of the shaft member, and the pushing force is generated from the pushing force generating mechanism to prevent the elastic force of the third elastic member from being transmitted to the shaft member. At the same time, the shaft member is pushed out to the tip side, and the unclamp mode is set in a state where the contact between the second inner peripheral surface portion of each collet member and the third protrusion of the shaft member is released. Has been done.
In this embodiment, the clamp mode can be easily and surely set without interfering with the setting of the unclamp mode.
In a different form of the present invention, an increasing mechanism is provided to increase the elastic force of the third elastic member and transmit it to the shaft member. As the boosting mechanism, for example, the first member fixed to the third elastic member and having the first tapered surface is inserted into the inner space of the main body and arranged so as to face the first tapered surface. , A second member having a second tapered surface inclined in the direction opposite to the inclined direction of the first tapered surface, a third member fixed to the shaft member, a first tapered surface, and a second taper. A boosting mechanism composed of a surface and a sphere arranged so as to be in contact with the third member can be used. The second member may be movably inserted into the inner space of the main body, or may be fixed to the main body in a state of being inserted into the inner space of the main body.
In this embodiment, the clamping force can be increased without increasing the elastic force of the third elastic member.
In a different embodiment of the present invention, the extending direction of the first inner peripheral surface portion of each collet member along the axial direction is parallel to the extending direction of the outer peripheral surface portion of the shaft member along the axial direction (including "substantially parallel"). ), A gap including a first gap and a second gap formed on the tip side of the first gap and having a wider gap than the first gap between two collet members adjacent to each other in the circumferential direction. Is configured to be formed. As a method of forming a gap including the first gap and the second gap between two collet members adjacent to each other in the circumferential direction, preferably, the shapes of the side surfaces of the collet members on both sides in the circumferential direction of each collet member are set. The method is used. The distance between the first gap and the second gap is set within a range in which the first protrusion of each collet member can be inserted into the shank inner space of the member to be clamped in the state of being set to the unclamp mode.
The shapes of the first gap and the second gap can be set as appropriate. For example, the first gap is set to a shape extending along the axial direction at an interval N, and the second gap is set to a shape extending along the axial direction at an interval M (M> N) wider than the interval N. Can be set. Alternatively, the first gap is set to a shape extending along the axial direction at the distance W, and the second gap is set to a distance V (V> W) wider than the distance W from the distance W from the rear end side to the front end side. ) Can be set so as to extend along the axial direction.
In this embodiment, by setting a wide interval M of the second gap on the tip side, it is possible to operate each collet member (the operation of bringing the second inner peripheral surface portion closer to the outer peripheral surface portion of the shaft member) when the unclamp mode is set. However, by setting the spacing N of the first gap on the rear end side to be narrow, it is possible to prevent variations in the spacing between the collet members when the clamp mode is set. That is, when the clamp mode is set, it is possible to prevent variations in the clamping force of the clamped member due to each collet member, and it is possible to stably clamp (hold) the clamped member.

The present invention can provide a clamp device having a simple configuration.

It is sectional drawing of one Embodiment of the clamp device using the collet device of 1st Embodiment. It is sectional drawing of the main body part of the clamp device of one Embodiment. It is a side view of the collet device of 1st Embodiment. FIG. 3 is a view seen from the direction of arrow IV. It is a VV line arrow view of FIG. It is sectional drawing of an example of the tool holder clamped by the collet device of 1st Embodiment. It is a figure explaining the operation of the clamp device of one Embodiment. It is a figure explaining the operation of the clamp device of one Embodiment. It is a figure explaining the operation of the clamp device of one Embodiment. It is a figure explaining the operation of the clamp device of one Embodiment. It is a figure which shows the state which the collet device of 1st Embodiment is set to a clamp mode in the state which the shank portion of a tool holder is not inserted (partially enlarged view of FIG. 7). It is a figure which shows the state which the collet device of 1st Embodiment is set to the unclamp mode in the state which the shank part of a tool holder is not inserted (partially enlarged view of FIG. 8). It is a figure which shows the state which the collet device of 1st Embodiment is set to a clamp mode in the state which the shank part of a tool holder is inserted (partially enlarged view of FIG. 10). It is a figure explaining the operation of a boosting mechanism. It is a side view of the 2nd Embodiment of the collet device used in the clamp device of 1 Embodiment. It is sectional drawing in the state which the collet device of 2nd Embodiment is set to the unclamp mode.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the present specification, the extending direction (horizontal direction in FIG. 1) of the center line P of the inner space of the main body is referred to as "axial direction", and the shank portion of the tool holder (clamped member) is in the inner space of the main body. The side to be inserted (the left side indicated by the arrow A in FIG. 1) is called the "tip side" or "one side along the axial direction", and the tool holder (clamped member) is inserted into the space inside the main body. The side opposite to the side (in FIG. 1, the right side indicated by the arrow B) is referred to as the "rear end side" or the "other side along the axial direction". Regarding the tool holder (member to be clamped), the side where the shank portion is inserted into the inner space of the main body is called the "rear end side" or the "other side along the axial direction", and is within the inner space of the main body. The side opposite to the side to be inserted is called "tip side" or "one side along the axial direction". Of course, the definition of each direction can be changed as appropriate.
Further, when viewed in a cross section perpendicular to the axial direction, the direction along the circle centered on the center line P of the inner space of the main body is called the "circumferential direction", and the direction of the line passing through the center line P is the "diameter direction". That is.

An embodiment of the clamp device of the present invention will be described with reference to FIGS. 1 and 2. Note that FIG. 1 is a cross-sectional view taken along the axial direction of the clamp device 100 of one embodiment, and FIG. 2 is a cross-sectional view taken along the axial direction of the main body portion (spindle 210, second member 350).
The clamp device 100 of the present embodiment is configured as a tool clamp device that clamps the tool holder.

An example 610 of a tool holder clamped by the clamping device 100 of the present embodiment will be described with reference to FIG. The tool holder 610 shown in FIG. 6 holds the tool 650.
The tool holder 610 has a tool holder rear end surface 610B, a tool holder inner peripheral surface 611, and a tool holder outer peripheral surface 612.
The tool holder inner peripheral surface 611 includes the tool holder inner peripheral surface portions 611a to 611e, and forms a tool holder inner space 610a in which one end side (rear end side) is open. Further, the tool holder outer peripheral surface 612 includes the tool holder outer peripheral surface portions 612a to 612c.
On the rear end side of the tool holder 610, a shank portion 620 to be inserted into the spindle inner space 210a (main body inner space) described later is provided. The shank portion 620 has a tool holder rear end surface 610B, a shank portion inner peripheral surface including the tool holder inner peripheral surface portions 611b to 611e, and a shank portion outer peripheral surface including the tool holder outer peripheral surface portion 612c. The inner peripheral surface of the shank portion and the outer peripheral surface of the shank portion have a circular cross section. The inner peripheral surface of the shank portion forms an inner space 620a of the shank portion in which one end side (rear end side) is open. The inner peripheral surface portion of the tool holder (inner peripheral surface portion of the shank portion) 611d included in the inner peripheral surface of the shank portion forms a recess 613 into which the protrusion 413A of the collet member 410, which will be described later, is inserted. Preferably, the recess 613 is formed as a groove extending along the circumferential direction.

The clamp device 100 of the present embodiment includes a spindle 210, a shaft member 310, an operating member 320, a disc spring 330, a first member 340, a second member 350, a third member 360, a sphere 370, a pin 380, a pushing member 390, and a collet. It is composed of a device 400 and a spring 430.

The spindle 210 includes a spindle tip surface 210A and spindle inner peripheral surface portions 211a to 211n, and has a spindle inner peripheral surface 211 that extends along the axial direction and forms a spindle inner space 210a in which the tip side is open. are doing. The inner peripheral surface portion 211f of the spindle protrudes inward in the radial direction. The inner peripheral surface portions 211d, 211f, 211h, 211k, and 211m of the spindle are formed as stepped surfaces.
The inner peripheral surface portion 211f of the spindle corresponds to the "inner peripheral surface portion of the main body portion protruding inward in the radial direction" of the present invention.
The second member 350 is formed in a tubular shape, and has a second member inner peripheral surface 351 and a second member outer peripheral surface 352 forming a second member front end surface 350A, a second member rear end surface 350B, and a second member inner space 350a. Have. The inner peripheral surface 351 of the second member is formed on a tapered surface whose inner diameter increases from the front end side to the rear end side. The inner peripheral surface 351 of the second member has a circular cross section.
The second member 350 is inserted into the spindle inner space 210a so as to be movable along the axial direction. The movement of the second member 350 to the tip side is restricted by the contact of the tip surface 350A of the second member with the inner peripheral surface portion 211m of the spindle. The second member 350 may be fixed to the spindle 210 in a state of being inserted into the spindle inner space 210a. The second member 350 constitutes a boosting mechanism. The boosting mechanism will be described later.

In the present embodiment, the spindle 210 (or the spindle 210 and the second member 350) constitutes the "main body portion" of the present invention, and the spindle inner peripheral surface portions 211a to 211n (or the spindle inner peripheral surface portions 211a to 211l) are formed. , The second member front end surface 350A, the second member inner peripheral surface 351 and the second member rear end surface 350B and the spindle inner peripheral surface portion 211n) constitute the "main body inner peripheral surface forming the main body inner space" of the present invention. Will be done. Further, the spindle tip surface 210A corresponds to the "main body front end surface" of the present invention.
Further, in the present embodiment, the center line P of the inner space of the main body extends in parallel with the axial direction (including "substantially parallel").

The shaft member 310 is arranged so as to be movable along the axial direction in the main shaft inner space 210a and the second member inner space 350a (that is, in the main body inner space).
The shaft member 310 has a shaft member outer peripheral surface 312 including the shaft member outer peripheral surface portions 312a to 312d. The outer peripheral surface 312 of the shaft member has a circular cross section.
The outer peripheral surface portion 312c of the shaft member extends along the axial direction. In the present embodiment, the shaft member outer peripheral surface portion 312c extends parallel to the axial direction (including "substantially parallel"). Further, the outer peripheral surface portions 312a and 312b of the shaft member form a protrusion 313A protruding outward in the radial direction from the outer peripheral surface portion 312c of the shaft member. In the present embodiment, the shaft member outer peripheral surface portion 312b is formed on a tapered surface that is inclined so that the distance from the center line P becomes longer from the rear end side to the front end side. Further, a male screw is formed on the outer peripheral surface portion 312d of the shaft member.
The protrusion 313A of the shaft member 310 corresponds to the "third protrusion" of the present invention.

The operating member 320 is formed in a tubular shape, and is arranged on the outer peripheral side of the outer peripheral surface portion 312c of the shaft member 310 so as to be movable along the axial direction with respect to the shaft member 310.
The operating member 320 includes an operating member front end surface 320A, an operating member rear end surface 320B, an operating member inner peripheral surface 321 including the operating member inner peripheral surface portions 321a to 321c, and an operating member outer peripheral surface 322 including the operating member outer peripheral surface portions 322a to 322d. have. The inner peripheral surface 321 of the operating member and the outer peripheral surface 322 of the operating member have a circular cross section.
A space into which the end portion of the spring 430 can be inserted is formed by the inner peripheral surface portions 321a and 321b of the operating member.
The outer peripheral surface portion 322a of the operating member is formed on a tapered surface that is inclined so that the distance from the center line P becomes longer from the front end side to the rear end side. The outer peripheral surface portion 322b of the operating member is formed in a stepped shape (stepped surface). A male screw is formed on the outer peripheral surface portion 322d of the operating member.

The disc spring 330 is arranged on the outer peripheral side of the shaft member outer peripheral surface portion 312c of the shaft member 310, and has elasticity that moves the shaft member 310 toward the rear end side with respect to the main body portion (spindle 210 or the main shaft 210 and the second member 350). Generate force. The elastic force of the disc spring 330 is transmitted to the shaft member 310 via the boosting mechanism.
In the present embodiment, the disc spring 330 is arranged in a compressed state between the inner peripheral surface portion 211h of the spindle and the tip surface 340A of the first member of the first member 340 constituting the boosting mechanism.
The disc spring 330 corresponds to the "third elastic member that generates an elastic force that moves the shaft member toward the rear end side with respect to the main body portion" of the present invention.

The boosting mechanism will be described with reference to the partially enlarged view of the boosting mechanism shown in FIG.
The boosting mechanism boosts the elastic force of the disc spring 330 and transmits it to the shaft member 310. As a result, as will be described later, the clamping force in the state where the collet device 400 (collet member 410) is set to the clamp mode can be increased without increasing the elastic force of the disc spring 330.
The boosting mechanism is composed of a first member 340, a second member 350, a third member 360, and a sphere 370.
The first member 340 has a first member outer peripheral surface 342 including a first member front end surface 340A, a first member rear end surface 340B, a first member inner peripheral surface 341, and a first member outer peripheral surface portion 342a. A female screw is formed on the inner peripheral surface 341 of the first member. In the first member 340, the female screw formed on the inner peripheral surface 341 of the first member is screwed to the male screw formed on the outer peripheral surface portion 322d of the operating member 320 and fixed to the operating member 320. In the state, it can move along the axial direction in the spindle inner space 210a (main body inner space). The outer peripheral surface portion 342a of the first member is formed on a tapered surface that is inclined so that the distance from the center line P becomes shorter from the front end side to the rear end side.
As described above, the second member 350 is inserted into the spindle inner space 210a. Further, the inner peripheral surface 351 of the second member is formed on a tapered surface that is inclined so that the distance from the center line P becomes longer from the front end side to the rear end side.
In the present embodiment, the first member outer peripheral surface portion 342a of the first member 340 is arranged at a position facing the second member inner peripheral surface 351 of the second member 350 at intervals.
The third member 360 has a third member front end surface 360A, a third member rear end surface 360B, and a third member inner peripheral surface 361. A female screw is formed on the inner peripheral surface 361 of the third member. In the third member 360, the female screw formed on the inner peripheral surface portion 361 of the third member is screwed to the male screw formed on the outer peripheral surface portion 312d of the shaft member 310 and fixed to the shaft member 310. In this state, it can move along the axial direction in the spindle inner space 210a (main body inner space).
The third member 360 is formed with a through hole 363 into which a pin 380, which will be described later, is movably inserted, at a position facing the rear end surface 340B of the first member of the first member 340.
In the sphere 370, the outer peripheral surface 372 abuts on the first member outer peripheral surface portion 342a of the first member 340, the second member inner peripheral surface portion 351 of the second member 350, and the third member tip surface 360A of the third member 360. Arranged as possible.

As shown in FIG. 14, when the first member 340 moves to the rear end side due to the elastic force of the disc spring 330 (moves from the position shown by the solid line to the position shown by the broken line), The sphere 370 moves toward the rear end side in a state where the outer peripheral surface 372 is in contact with the outer peripheral surface portion 342a of the first member and the inner peripheral surface 351 of the second member (shown by a broken line from the position shown by the solid line). Move to position). When the sphere 370 moves to the rear end side, the shaft member fixed to the third member 360 and the third member 360 by the contact between the outer peripheral surface 372 of the sphere 370 and the third member tip surface 360A of the third member 360. The 310 moves to the rear end side (moves from the position indicated by the solid line to the position indicated by the broken line).
Here, the inclination angle α of the outer peripheral surface portion 342a of the first member formed in a tapered shape and the inclination of the inner peripheral surface 351 of the second member formed in a tapered shape opposite to the outer peripheral surface portion 342a of the first member. By appropriately setting the angle β, the ratio (L / K) of the moving distance L to the rear end side of the third member 360 to the moving distance K to the rear end side of the first member 340 is made smaller than 1. Can be done. That is, the force for moving the shaft member 310 fixed to the third member 360 toward the rear end side can be increased.
In the present embodiment, the "strengthening mechanism" of the present invention is composed of the first member 340, the second member 350, the third member 360, and the sphere 370. Further, the outer peripheral surface portion 342a of the first member corresponds to the "first tapered surface of the first member" of the present invention, and the inner peripheral surface 351 of the second member is the "second tapered surface of the second member" of the present invention. Corresponds to.

The collet device 400 of the first embodiment used in the clamp device 100 of the present embodiment will be described with reference to FIGS. 3 to 4. 3 is a side view of the collet device 400 of the first embodiment, FIG. 4 is a view of FIG. 3 viewed from the direction of arrow IV, and FIG. 5 is a view taken along the line VV of FIG. It is a figure.
The collet device 400 of the present embodiment is composed of a collet and an annular spring 420.
The collet has a plurality of collet members 410 arranged side by side in the circumferential direction on the outer peripheral side of the shaft member outer peripheral surface portion 312c of the shaft member 310.
The collet member 410 extends along the circumferential direction and the axial direction along the outer peripheral surface portion 312c of the shaft member, and is arranged on the side facing the front end surface 410A of the collet member, the rear end surface 410B of the collet member, and the outer peripheral surface portion 312c of the shaft member. It has a collet member inner peripheral surface 411, a collet member outer peripheral surface 412 arranged on the opposite side of the shaft member outer peripheral surface portion 412c, and a collet member side surface 415 arranged on one side and the other side along the circumferential direction. There is. As shown in FIG. 4, the collet member 410 extends in an arc shape when viewed from the axial direction.
The collet member inner peripheral surface 411 includes collet member inner peripheral surface portions 411a to 411e.
Looking at the cross section along the axial direction (see FIG. 5), the extending direction of the collet member inner peripheral surface portion 411a along the axial direction is the extending direction of the collet member inner peripheral surface portion 411b along the axial direction. On the other hand, it is tilted at the tilt angle θ. The inclination angle θ is a state in which the extending direction of the collet member inner peripheral surface portion 411b along the axial direction is parallel to the extending direction of the shaft member outer peripheral surface portion 312c along the axial direction (including “substantially parallel”). The distance between the inner peripheral surface portion 411a of the collet member and the outer peripheral surface portion 312c of the shaft member is set so as to increase from the rear end side to the front end side. The inclination angle θ is represented by an angle defined by the inner peripheral surface portions 411a and 411b of the collet member. In the present embodiment, the angle is expressed as an angle defined by a line extending the extending line along the axial direction of the collet member inner peripheral surface portion 411b toward the tip side and an extending line along the axial direction of the collet member inner peripheral surface portion 411a. Has been done. Of course, it can also be represented by an angle defined by an extending line along the axial direction of the collet member inner peripheral surface portion 411b and an extending line along the axial direction of the collet member inner peripheral surface portion 411a.
The collet member tip surface 410A and the collet member outer peripheral surface portion 412a form a protrusion 413A protruding to the opposite side of the collet member inner peripheral surface 411 at the tip portion of the collet member 410.
Further, the rear end surface 410B of the collet member, the outer peripheral surface portion 412g, 412h of the collet member, and the inner peripheral surface portions 411c to 411e of the collet member project to the rear end portion of the collet member 410 on the side opposite to the inner peripheral surface 411 of the collet member. A protrusion 413B is formed.
The collet member inner peripheral surface portion 411e is formed on a tapered surface that is inclined so that the distance from the center line P becomes shorter from the rear end side to the front end side.
Further, the collet member outer peripheral surface portion 412 g is formed on a tapered surface that is inclined so that the distance from the center line P becomes shorter from the rear end side to the front end side.
The collet member inner peripheral surface portion 411b corresponds to the "first inner peripheral surface portion of the collet member" of the present invention, and the collet member inner peripheral surface portion 411a corresponds to the "second inner peripheral surface portion of the collet member" of the present invention. The protrusion 413A corresponds to the "first protrusion" of the present invention, and the protrusion 413B corresponds to the "second protrusion" of the present invention.

Further, as shown in FIGS. 3 to 5, the extending direction of each collet member 410 along the axial direction of the collet member inner peripheral surface portion 411b is along the axial direction of the shaft member outer peripheral surface portion 312c. A state parallel to the extending direction (specifically, the collet member inner peripheral surface portion 411b of each collet member 410 is the extending direction along the axial direction of the collet member inner peripheral surface portion 411b and the shaft member outer peripheral surface portion 312c. (In a state where it is arranged on the outer peripheral side of the outer peripheral surface portion 312c of the shaft member so that the extending directions along the axial direction are parallel), between two collet members 410 adjacent to each other in the circumferential direction, along the axial direction. An extending gap 416 is formed. The gap 416 includes a gap 416B and a gap 416A formed on the tip side of the gap 416B and having a gap wider than the gap of the gap 416B. Specifically, the collet member side surface 415 of each collet member 410 is a collet member side surface portion that connects the collet member side surface portions 415a and 415c extending along the axial direction and the collet member side surface portions 415a and 415c in a stepped shape. It is configured to include 415b (FIG. 3).
In the present embodiment, the gap 416B extends along the axial direction at a gap N, and the gap 416A extends along the axial direction at a gap M (M> N) wider than the gap N of the gap 416B. ..
The gap 416B corresponds to the "first gap" of the present invention, and the gap 416A corresponds to the "second gap" of the present invention.

From the state where the collet member inner peripheral surface portion 411b approaches the shaft member outer peripheral surface portion 312c and the collet member inner peripheral surface portion 411a is separated from the shaft member outer peripheral surface portion 312c (clamp mode), the collet member inner peripheral surface portion 411b When the collet member inner peripheral surface portion 411a shifts to a state (unclamp mode) away from the shaft member outer peripheral surface portion 312c and approaches the shaft member outer peripheral surface portion 312c, the collet members 410 adjacent to each other in the circumferential direction should not come into contact with each other. , Collet members 410 adjacent to each other in the circumferential direction need to be arranged at a wide interval. On the other hand, when the collet members 410 adjacent in the circumferential direction are arranged with a wide gap, the collet member adjacent in the circumferential direction is in a state where the inner peripheral surface portion 411b of the collet member approaches the outer peripheral surface portion 312c of the shaft member (clamp mode). There is a risk that the intervals between 410 will vary. If the distance between the collet members 410 varies, the clamping force of the tool holder 610 (material to be clamped) by each collet member 410 varies, and the holding characteristics of the tool holder 410 may deteriorate.
In the present embodiment, gaps having different intervals are formed between two collet members 410 adjacent to each other in the circumferential direction, and the gap M of the gap 416A formed on the front end side is set to the gap 416B formed on the rear end side. It is wider than the interval N of. By widening the distance M of the gap 416A on the tip side, it is possible to prevent the collet members 410 adjacent to each other in the circumferential direction from coming into contact with each other when the unclamp mode is set. Further, by narrowing the interval N of the gap 416B on the rear end side, it is possible to prevent the interval between the collet members 410 from fluctuating when the clamp mode is set. As a result, the clamping force of the tool holder 610 (member to be clamped) by each collet member 410 can be made substantially equal, and the tool holder 610 can be stably held.

The annular spring 420 generates an elastic force that moves the collet members 410 arranged side by side along the circumferential direction inward in the radial direction. In the present embodiment, an annular spring having a C shape is used as the annular spring 420. An O-ring can also be used as the annular spring 420.
The outer peripheral surface portions 412d to 412f of the collet member form a groove 412A extending along the circumferential direction at a position corresponding to the inner peripheral surface portion 411b of the collet member on the tip side of the outer peripheral surface of the collet member 412 from the protrusion 413B. Will be done.
The annular spring 420 is inserted into the groove 412A of each collet member 410 arranged side by side along the circumferential direction in an extended state. As a result, the elastic force of the annular spring 420 acts as a force that brings the collet member inner peripheral surface portion 411b of the collet member 410 closer to the shaft member outer peripheral surface portion 312c.
In the present embodiment, the annular spring 420 corresponds to the "first elastic member" of the present invention.

The spring 430 is arranged in a compressed state between each collet member 410 and the operating member 320. The elastic force of the spring 430 acts as a force for moving each collet member 410 toward the tip end side with respect to the operating member 320. As a result, in each collet member 410, the protrusion 413B, specifically, the collet member outer peripheral surface portion 412g forming the protrusion 413B is formed on the spindle inner peripheral surface portion 211f (main body portion inner peripheral surface portion protruding inward in the radial direction). Move to the tip side so as to abut.
In the present embodiment, the spring 430 corresponds to the "second elastic member" of the present invention.

As described above, the third member 360 constituting the boosting mechanism is formed with a through hole 363 at a position facing the rear end surface 340B of the first member of the first member 340. A pin 380 is inserted into the through hole 363 so as to be movable along the axial direction.
In addition, a pushing member 390 that pushes the pin 380 toward the tip is provided.
When the pushing member 390 moves to the rear end side, that is, when the pin 380 is not pushed toward the tip side by the pushing member 390, the first member 340 is pushed toward the rear end side by the elastic force of the disc spring 330. Then, it comes into contact with the tip surface 360A of the third member of the third member 360. In this case, the elastic force of the disc spring 330 is transmitted to the shaft member 310 via the boosting mechanism. That is, the elastic force of the disc spring 330 acts as a force for moving the shaft member 310 toward the rear end side.
On the other hand, when the pushing member 390 moves to the tip side, that is, when the pin 380 is pushed toward the tip side by the pushing member 390, the pin 380 moves to the tip side and after the first member of the first member 340. It abuts on the end face 340B. As a result, the rear end surface 340B of the first member is separated from the tip surface 360A of the third member, and the elastic force of the disc spring 330 is prevented from being transmitted to the shaft member 310. When the pushing member 390 further moves toward the tip end side, the pushing member 390 comes into contact with the rear end surface 360B of the third member of the third member 360, and the third member 360 is pushed toward the tip end side. As a result, the shaft member 310 fixed to the third member 360 also moves to the tip end side.
In the present embodiment, the "pushing force generating mechanism" of the present invention is configured by the pin 380 and the pushing member 390.

The operation of the clamp device 100 will be described with reference to FIGS. 7 to 10.
First, the operation in a state where the shank portion 620 of the tool holder 610 is not inserted in the spindle inner space (main body inner space) 210a will be described with reference to FIGS. 7 and 11.
In the state where the shank portion 620 of the tool holder 610 is not inserted in the spindle inner space 210a, the pushing member 390 is moved to the rear end side. In this case, since the pin 380 is not pushed toward the front end by the pushing member 390, the first member 340 moves toward the rear end by the elastic force of the disc spring 330. When the first member 340 moves to the rear end side, the first member rear end surface 340B of the first member 340 comes into contact with the third member tip surface 360A of the third member 360, and is fixed to the third member 360. The shaft member 310 also moves to the rear end side. The movement of the first member 340 to the rear end side is regulated by the contact between the outer peripheral surface 322b of the operating member 320 fixed to the first member 340 and the end portion of the disc spring 330.
A spring 430 that generates an elastic force that moves each collet member 410 toward the tip side with respect to the operating member 320 is provided between each collet member 410 and the operating member 320. Therefore, in each collet member 410, the protrusion 413B (the outer peripheral surface portion of the collet member forming the protrusion 413B 412 g) comes into contact with the inner peripheral surface portion 211f of the spindle (the inner peripheral surface portion of the main body portion protruding inward in the radial direction). Placed in position.
At this time, since each collet member 410 is not pushed by the operating member 320, in each collet member 410, the collet member inner peripheral surface portion 411b approaches the shaft member outer peripheral surface portion 312c due to the elastic force of the annular spring 420, and the inside of the collet member The peripheral surface portion 411a is separated from the outer peripheral surface portion 312c of the shaft member, and the protrusion 413A is set to the clamp mode in which the protrusion 413A moves (projects) radially outward.
As the shaft member 310 moves to the rear end side, the tip of the collet member inner peripheral surface portion 411a of each collet member 410 has a tapered shape that forms the protrusion 313A of the shaft member 310 (specifically, the protrusion 313A). It comes into contact with the outer peripheral surface portion 312b) of the shaft member. As a result, in the protrusion 413A of each collet member 410, the collet member inner peripheral surface portion 411b extends in the extending direction along the axial direction of the collet member inner peripheral surface portion 411b and in the axial direction of the shaft member inner peripheral surface portion 312c. It is lifted radially outward from the position when it is arranged on the outer peripheral side of the shaft member outer peripheral surface portion 312c so that the extending directions along the lines are parallel.

Next, the operation when the shank portion 620 of the tool holder 610 is inserted into the spindle inner space 210a (main body inner space) will be described with reference to FIGS. 8 and 12.
The pushing member 390 is moved toward the tip side, and the pin 380 is pushed toward the tip side. When the pin 380 is pushed toward the tip end side, the pin 380 comes into contact with the rear end surface 340B of the first member of the first member 340, and the operating member 320 fixed to the first member 340 and the first member 340 is also pushed toward the tip end side. Is done.
When the first member 340 is pushed toward the tip end side, the elastic force of the disc spring 330 is prevented from being transmitted to the third member 360 and the shaft member 310 fixed to the third member 360.
When the pushing member 390 is further moved to the tip side, the pushing member 390 comes into contact with the rear end surface 360B of the third member of the third member 360, and the shaft member 310 fixed to the third member 360 and the third member 360 is tipped. Pushed to the side. At this time, since the elastic force of the disc spring 330 is prevented from being transmitted to the third member 360, the third member 360 and the shaft member 310 are smoothly pushed toward the tip end side.
The operating member 320 moves to the tip side, and the operating member 320 (specifically, the tapered operating member outer peripheral surface portion 322a) forms the protrusion 413B (specifically, the protrusion 413B) of each collet member 410. The protrusion 413B is pushed (specifically, pushed toward the tip side and radially outward) by abutting against the surface portion 411d or 411e). Further, when the shaft member 310 moves to the tip end side, the contact between the collet member inner peripheral surface portion 411b of each collet member 410 and the protrusion 313A of the shaft member 310 is released. As a result, the collet member inner peripheral surface portion 411a of each collet member 410 approaches the shaft member inner peripheral surface portion 312c against the elastic force of the annular spring 420, and the collet member inner peripheral surface portion 411b becomes the shaft member outer peripheral surface portion. It is set to an unclamp mode in which the protrusion 413A moves inward in the radial direction away from the 312c.
In the state of being set to the unclamp mode, the protrusion 413A of each collet member 410 can be inserted into the shank inner space 620a of the tool holder 610. Specifically, the maximum outer diameter H (see FIG. 12) of the protrusion 413A of each collet member 410 in the state of being set to the unclamp mode is the inner diameter D of the shank inner space 620a of the tool holder 610 (FIG. 6). (See) is set to be smaller (H <D).

Next, the operation of inserting the shank portion 620 of the tool holder 610 into the spindle inner space 210a (main body inner space) will be described with reference to FIG.
In the state of being set to the unclamp mode, the shank portion 620 of the tool holder 610 is inserted into the spindle inner space 210a (main body inner space), and the protrusion 413A of each collet member 410 is inserted into the shank inner space 620a. insert. At this time, the protrusion 413A of each collet member 410 is arranged at a position facing the recess 613 provided on the inner peripheral surface of the shank portion of the tool holder 610.

Next, the operation of clamping the tool holder 610 will be described with reference to FIGS. 10 and 13.
The pushing member 390 is moved to the rear end side, and the pushing of the first member 340 fixed to the operating member 320 and the third member 360 fixed to the shaft member 310 is stopped.
When the first member 340 and the third member 360 are not pushed, the elastic force of the disc spring 330 causes the operating member 320 fixed to the first member 340 and the first member 340 to move to the rear end side. Further, the elastic force of the disc spring 330 increased by the increasing mechanism causes the third member 360 and the shaft member 310 fixed to the third member 360 to move to the rear end side. As a result, due to the elastic force of the annular spring 420, the collet member inner peripheral surface portion 410b of each collet member 410 approaches the shaft member inner peripheral surface portion 312c, and the collet member inner peripheral surface portion 411a separates from the shaft member outer peripheral surface portion 312c. , The protrusion 413A is set to the clamp mode in which the protrusion 413A moves outward in the radial direction. At this time, the tip of the collet member inner peripheral surface portion 411a of each collet member 410 comes into contact with the protrusion 313A (shaft member outer peripheral surface portion 312b forming the protrusion 313A) of the shaft member 310, whereby the annular spring 420 The clamping force due to the contact between the tip end portion of the collet member inner peripheral surface portion 411a and the protrusion 313A is applied to the clamping force due to the elastic force. That is, the clamping force is increased.
The radial outward movement of the protrusion 313A is restricted by the insertion of the protrusion 313A into the recess 613 of the tool holder 610.

The collet device 500 of the second embodiment in which the shape of the gap formed between the two collet members adjacent to each other in the circumferential direction is changed is shown in FIGS. 15 and 16.
The collet device 500 of the present embodiment is composed of a collet and an annular spring 420, similarly to the collet device 400 of the first embodiment. The collet has a plurality of collet members 510 arranged side by side along the circumferential direction on the outer peripheral side of the shaft member outer peripheral surface portion 312c of the shaft member 310. Further, similarly to the collet device 400 of the first embodiment, the elastic force of the annular spring 420 brings the inner peripheral surface portion 511b of the collet member of each collet member 510 closer to the outer peripheral surface portion 312c of the shaft member, and the protrusion 513A in the radial direction. It is configured to act as a force to move it outward.
Further, a state in which the extending direction of the collet member inner peripheral surface portion 511b of each collet member 510 along the axial direction is parallel to the extending direction of the shaft member outer peripheral surface portion 312c along the axial direction (specifically, each of them). The extension direction of the collet member inner peripheral surface portion 511b of the collet member 510 along the axial direction of the collet member inner peripheral surface portion 511b is parallel to the extension direction of the shaft member outer peripheral surface portion 312c along the axial direction. The gap 516 formed between the two collet members 510 adjacent in the circumferential direction is formed on the tip side of the gap 516B and the gap 516B in the state (arranged on the outer peripheral side of the outer peripheral surface portion 312c of the shaft member). Includes a gap of 516A.
The gap 516B extends along the axial direction at a gap W, and the gap 516A has a gap V (V> W) wider than the gap W from the gap W from the rear end side to the front end side. It extends along the axial direction.
Specifically, the collet member side surface 515 of each collet member 510 is inclined with respect to the collet member side surface portion 515b extending along the axial direction and the extending direction with respect to the extending direction of the collet member side surface portion 515b. It is configured to include the side surface portion 515a of the collet member (FIG. 15).
The collet 500 of the present embodiment also has the same effect as the collet 400 of the first embodiment.
The gap 516B corresponds to the "first gap" of the present invention, and the gap 516A corresponds to the "second gap" of the present invention.

The present invention is not limited to the configuration described in the embodiment, and various changes, additions, and deletions can be made.
As the elastic member, various known elastic members can be used.
The configuration of the pushing force generating mechanism can be changed as appropriate.
Collet member protrusions (413B, 513B), shaft member protrusions (313A), disc springs, booster mechanism, inner peripheral surface portion (211f) of the main body protruding inward in the radial direction, springs (430), etc. are required. It can be appropriately selected according to the above.
The protrusion 413A (513A) is referred to as the "first protrusion", the protrusion 413B (513B) is referred to as the "second protrusion", and the protrusion 313A is referred to as the "third protrusion", but the name of the protrusion can be changed as appropriate. Is.
The annular spring 420 is referred to as a "first elastic member", the spring 430 is referred to as a "second elastic member", and the disc spring 330 is referred to as a "third elastic member", but the names of the elastic members can be changed as appropriate.
Each configuration described in the embodiment may be used alone, or a plurality of configurations selected as appropriate may be used in combination.
The present invention can be configured as a clamping device that clamps (holds) various members to be clamped other than the tool holder.

100 Clamping device 210 Spindle (main body)
210A Main shaft tip surface 210a Main shaft inner space 211 Main shaft inner peripheral surface 211a to 211n Main shaft inner peripheral surface portion 310 Shaft member 312 Shaft member outer peripheral surface 312a to 312c Shaft member outer peripheral surface portion 313A Protrusion (third protrusion)
320 Acting member 320A Acting member front end surface 320B Acting member rear end surface 320a Acting member inner space 321 Acting member inner peripheral surface 321a to 321c Acting member inner peripheral surface portion 322 Acting member outer peripheral surface 322a to 322d Actuating member outer peripheral surface portion 330 Belleville spring ( 3rd elastic member)
340 First member 340A First member front end surface 340B First member rear end surface 341 First member inner peripheral surface 342 First member outer peripheral surface 342a First member outer peripheral surface portion (first tapered surface)
350 Second member 350A Second member front end surface 350B Second member rear end surface 351 Second member inner peripheral surface (second tapered surface)
352 Second member outer peripheral surface 360 Third member 360A Third member tip surface 361 Third member inner peripheral surface 363 Hole 370 Sphere 372 Sphere outer peripheral surface 380 Pin 390 Pushing member 400, 500 Collet device 410, 510 Collet member 410A, 510A Collet Member front end surface 410B, 510B Collet member rear end surface 410a, 510a Collet member inner space 411, 511 Collet member inner peripheral surface 411a to 411e, 511a to 511e Collet member inner peripheral surface portion 412, 512 Collet member outer peripheral surface 412a to 412h, 512a ~ 512h Collet member outer peripheral surface portion 413A, 513A protrusion (first protrusion)
413B, 513B protrusion (second protrusion)
415, 515 Collet side surface 415a to 415c, 515a, 515b Collet member side surface part 416A, 416B, 516A, 516B Gap 420 annular spring (reduced diameter spring) (first elastic member)
430 spring (second elastic member)
610 Tool holder 610B Tool holder rear end surface 610a Tool holder inner space 611 Tool holder inner peripheral surface 611a to 611e Tool holder inner peripheral surface part 612 Tool holder outer peripheral surface 612a to 612c Tool holder outer peripheral surface part 613 Groove 620 Shank part 620a Shank part inside Space 650 tools

Claims (8)

It has a shank portion that extends along the axial direction and has a shank portion inner space that is open at one end side, and a recess is provided on the inner peripheral surface of the shank portion that forms the shank portion inner space. A clamping device that clamps a member to be clamped.
A main body having an inner peripheral surface of the main body that forms an inner space of the main body that extends along the axial direction and has an opening on the tip side.
A shaft member arranged in the space inside the main body and having a shaft member outer peripheral surface including a shaft member outer peripheral surface portion extending along the axial direction,
A collet arranged on the outer peripheral side of the outer peripheral surface portion of the shaft member and
With the first elastic member
A tubular operating member that is arranged on the outer peripheral side of the outer peripheral surface portion of the shaft member and is located on the rear end side of the collet and can move along the axial direction with respect to the shaft member.
A mechanism for generating an pushing force capable of generating a pushing force for pushing the operating member toward the tip side is provided.
The collet has a plurality of collet members arranged side by side in the circumferential direction on the outer peripheral side of the outer peripheral surface portion of the shaft member.
Each collet member extends in the circumferential direction and the axial direction along the outer peripheral surface portion of the shaft member, and protrudes to the inner peripheral surface of the collet member, the outer peripheral surface of the collet member, and the side opposite to the inner peripheral surface of the collet member. Has a first protrusion that can be inserted into the recess of the clamped member.
The inner peripheral surface of the collet member is formed on the first inner peripheral surface portion and the tip end side of the first inner peripheral surface portion, and the extending direction along the axial direction is the extension direction when viewed in a cross section along the axial direction. Includes the second inner peripheral surface portion that is inclined at an inclination angle θ with respect to the extending direction along the axial direction of the first inner peripheral surface portion.
The inclination angle θ is the second inner circumference in a state where the extending direction along the axial direction of the first inner peripheral surface portion is parallel to the extending direction along the axial direction of the outer peripheral surface portion of the shaft member. The distance between the surface portion and the outer peripheral surface portion of the shaft member is set so as to widen from the rear end side toward the front end side.
The elastic force of the first elastic member is configured to act as a force that brings the first inner peripheral surface portion of each collet member closer to the outer peripheral surface portion of the shaft member.
By generating the pushing force from the pushing force generating mechanism, the operating member comes into contact with each collet member, and the operating member pushes each collet member to resist the elastic force of the first elastic member. Then, the second inner peripheral surface portion of each collet member is set to the unclamp mode in which the first protrusion portion moves inward in the radial direction as the second inner peripheral surface portion approaches the shaft member outer peripheral surface portion, and the pushing force generating mechanism is used. By stopping the generation of the pushing force, the elastic force of the first elastic member causes the first inner peripheral surface portion of each collet member to approach the outer peripheral surface portion of the shaft member and the first protrusion. A clamping device characterized in that it is configured to be set to a clamping mode that moves radially outward. The clamp device according to claim 1.
The tilt angle θ is a clamping device in which the first protrusion is set to be insertable in the space inside the shank portion of the member to be clamped in a state of being set to the unclamping mode. The clamp device according to claim 1 or 2.
Each collet member has a second protrusion protruding from the inner peripheral surface of the collet member on the rear end side of the first protrusion.
The clamping device is characterized in that the operating member is configured to be set to the unclamping mode by abutting on the second protrusion of each collet member and pushing the second protrusion. .. The clamp device according to claim 3.
The inner peripheral surface of the main body includes an inner peripheral surface portion of the main body protruding inward in the radial direction.
The inner peripheral surface portion of the main body portion is arranged between the first protrusion and the second protrusion of each collet member.
The operating member abuts on the second protrusion of each collet member and pushes the second protrusion, so that the second protrusion is in contact with the inner peripheral surface portion of the main body portion. A clamp device characterized in that it is configured to be set to clamp mode. The clamp device according to claim 4.
A clamp device provided with a second elastic member that generates an elastic force that moves each collet member toward the tip end side with respect to the operating member. The clamp device according to any one of claims 1 to 5.
The shaft member is arranged so as to be movable along the axial direction with respect to the main body portion, and a third protrusion protruding from the outer peripheral surface portion of the shaft member toward the tip side of the outer peripheral surface portion of the shaft member. Have and
A third elastic member that generates an elastic force that moves the shaft member toward the rear end side with respect to the main body portion is provided.
By generating the pushing force from the pushing force generating mechanism, the elastic force of the third elastic member is prevented from being transmitted to the shaft member, and the shaft member is pushed out toward the tip end side. Being done
By stopping the generation of the pushing force from the pushing force generating mechanism, the shaft member moves to the rear end side by the elastic force of the third elastic member, and the second inner peripheral surface portion of each collet member. The clamp mode is set in a state where a part of the shaft member is in contact with the third protrusion of the shaft member, and the pushing force is generated from the pushing force generating mechanism to generate the elastic force of the third elastic member. Is prevented from being transmitted to the shaft member, and the shaft member is pushed out toward the tip end side, so that the second inner peripheral surface portion of each collet member and the third protrusion of the shaft member come into contact with each other. A clamping device characterized in that it is configured to be set to the unclamping mode in a state where the contact is released. The clamp device according to claim 6.
A clamp device provided with an increasing mechanism for increasing the elastic force of the third elastic member and transmitting it to the shaft member. The clamp device according to any one of claims 1 to 7.
2 adjacent to the circumferential direction in a state where the extending direction of each collet member along the axial direction of the first inner peripheral surface portion is parallel to the extending direction of the outer peripheral surface portion of the shaft member along the axial direction. A gap is formed between the two collet members, and the gap is configured to include a first gap and a second gap formed on the tip side of the first gap and having a gap wider than the gap of the first gap. Clamping device characterized by being

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