TWI574773B - Collet chuck, chuck apparatus, and method for manufacturing worked products - Google Patents

Description

Collet chuck, chuck device, and method of manufacturing the same

The present invention relates to a collet chuck, a chuck device, and a method of manufacturing a processed article, and more particularly to a fixing structure for machining a part suitable for improving the machining accuracy in the axial direction of the machined part.

In general, various types of machine tools used in the processing of precision parts require a chuck device for holding materials or tools. As the chuck device, for example, a collet chuck having a groove and which can be enlarged and reduced in the radial direction is used. The tubular member is provided with a tapered or inverted tapered pressing surface, and the acting member such as a sleeve or a tie rod having a pressing surface corresponding to the pressed surface is driven in the axial direction. When the chucking head is opened and closed, the gripping portion can hold the parts, tools, and the like. In particular, in the case where the front surface processing is performed while the processing material is held on the main shaft, and the front end of the semi-finished product after the front processing is applied to the back main shaft for back processing, The collet device is an extremely important part of ensuring the shape accuracy of the machined part.

As a conventional chuck device, there is known a method for holding a machined material having a different diameter so as to accommodate a cylindrical sleeve having a groove in the inside of a conventional collet chuck (refer to the following) Patent Documents 1 and 2). Further, a chuck structure for accommodating the clamp arm inside the collet chuck is also known (refer to Patent Document 3 below).

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open Publication No. 2007-152509

Patent Document 2: Japanese Patent Publication No. Sho 51-39899

Patent Document 3: Japanese Patent Publication No. 57-7448

However, in the above-described conventional chuck device, in the case where drilling processing, broaching, or the like is performed in a state where a large load is applied in the axial direction while holding the processing material, the processing material is opposed to The grip portion escapes in the axial direction, and the machining accuracy in the axial direction of the machined component is deteriorated, and the gripped surface of the machined component is damaged, which may cause a defect. In particular, when the load is applied during the back surface processing, a machining offset in the axial direction occurs between the front surface processed portion and the back surface processed portion. Further, when the outer surface of the semi-finished product has an inverted tapered shape which is inclined toward the proximal end side in the axial direction, the semi-finished product easily escapes toward the front end side of the chuck device during the back surface processing, and thus is more likely to be defective. .

Therefore, the present invention has been made to solve the above problems, and an object thereof is to realize a collet chuck, a chuck device, and a method of manufacturing a processed article, which can improve the shape accuracy of a machined part by preventing the holding position from being shifted in the axial direction. , reduce the rate of non-performing.

In view of the above circumstances, the collet chuck of the present invention is characterized in that: a cylindrical main collet; and a cylindrical sub-cylinder on the inner peripheral side of the main collet, with respect to the main cylinder The clip is movably disposed in the axial direction, and the main collet clamp is There are: a plurality of slots extending in the axial direction; a pressed surface disposed on the outer circumference and being a pressurized surface for expanding and contracting the inner diameter of the main collet, that is, configured to face a tapered or inverted tapered shape on either side of the axial direction; and a main-side inclined surface that is disposed on the inner circumference and configured to have an inverted tapered shape toward the front end side in the axial direction in an inclined manner, the secondary cylinder The clamping system has: a plurality of slots extending in the axial direction; a gripping surface disposed on the inner circumference and configured to hold the held material; and a secondary side inclined surface disposed on the outer circumference and configured to be The main side inclined surface creates an inverted cone of engagement. That is, the collet chuck holds the outer diameter grip type collet chuck of the outer diameter of the grip material.

According to the present invention, the inner diameter of the main collet is enlarged and contracted by the presence or absence of pressurization of the pressed surface, whereby the sub-clip of the main collet is driven by the main inclined surface of the main collet Since the side inclined surface expands and contracts the inner diameter of the sub-cylinder clip, the gripping material can be gripped from the outside by the grip surface provided on the inner circumference of the sub-cylinder clip. In the gripping state, when a force is applied to the material to be gripped from the front end side in the axial direction, the sub-clamp holding the held material is moved toward the base end in the axial direction with respect to the main collet, but The auxiliary side inclined surface is joined to the main side inclined surface to reduce the inner diameter of the secondary collet so that the holding force of the gripping surface of the sub-clamp is increased, and thus the axial direction of the material to be gripped is not easily generated. Position offset. Further, by reducing the positional deviation of the material to be gripped, it is possible to suppress the occurrence of damage of the surface portion of the material to be gripped which is in contact with the grip surface.

In the present invention, it is preferable to further include an axial direction spring that applies a potential energy to the front end side of the sub-clamp in the axial direction with respect to the main collet. According to this configuration, in the gripping state of the material to be gripped, even when the holding force is increased by the force of the proximal end of the main collet in the axial direction by the sub-cylinder, the main collet is When the transition to the release state is performed, the potential energy is added to the sub-cylinder by the axial direction spring toward the front end side in the axial direction, so that the sub-clamp becomes easy to be gripped. In the case where the material to be gripped is gripped by the insertion of the material to be held by the sub-cylinder, and the material to be gripped is pressed in the state of being pressed toward the base end side of the main collet, the material to be gripped is When the gripping material is released, it becomes easy to return to the original position.

In the present invention, it is preferable that the sub-cylinder clip has a positioning locking portion that locks the grasped material from the base end side in the axial direction when the position is in the released state. According to this configuration, the gripping material is gripped by the positioning engagement portion, and the positional accuracy of the sub-cylinder and the material to be gripped in the axial direction can be ensured. The positioning locking portion may be provided at a portion of the grip surface (for example, a base end in the axial direction of the grip surface), or may be provided at a position separated from the grip surface (for example, the base end side in the axial direction). At this time, the grip surface of the sub-cylinder clip may have an engagement grip portion that protrudes in the radial direction, which makes it possible to grasp the jump. In this case, it is preferable that the positioning locking portion is separated from the proximal end side in the axial direction of the engaging and gripping portion.

In the present invention, it is preferable that the grip surface of the sub-cylinder is a frustum-shaped surface that is inclined toward the front end side in the axial direction. That is, if the collet chuck is of the outer diameter holding type as described above, the gripping surface is preferably configured as an inverted taper which is inclined toward the front end side in the axial direction. According to this configuration, in the case where the grip surface of the sub-cylinder is formed into a reverse taper shape according to the shape of the material to be gripped, the gripped material faces the machining force or impacts due to the processing force or impact in the axial direction. The possibility of a positional shift on the front end side in the direction opposite to the axial direction is increased. Therefore, according to the above configuration of the present invention, the displacement of the position can be prevented, and the effect of the damage of the material to be held can be prevented from becoming more conspicuous. .

In the present invention, it is preferable that the main collet has a guide surface extending in the axial direction on the inner circumference, and the sub-cylinder clip is provided on the outer circumference to be slidably coupled to the guide surface. The guided surface in the axial direction. According to this configuration, the guide of the main collet The guiding surface is guided by the guiding surface in the axial direction, and when the secondary collet moves in the axial direction with respect to the main collet, the axial shift and the angle change of the gripping surface of the sub-clamp can be suppressed, so that the material to be gripped is When the supply position (the insertion depth of the main collet) is inconsistent, the processing accuracy of the material to be gripped can be prevented from being lowered.

In this case, it is preferable that the groove of the main collet and the groove of the sub-cylinder are formed so as to extend toward the proximal end side from the front end edge in the axial direction, and the guide surface is formed. The region to be guided on the proximal end side in the axial direction with respect to the main-side inclined surface is formed in a region on the proximal end side in the axial direction with respect to the secondary-side inclined surface. According to this configuration, the groove of the main collet and the groove of the sub-cylinder are configured to expand and contract the region on the front end side in the axial direction by forming the front edge from the axial direction. The guide surface is provided in a region on the proximal end side in the axial direction with respect to the inclined surface on the main side, and the guided surface is provided in a region on the proximal end side in the axial direction with respect to the inclined surface on the secondary side. The deformation of the guide surface and the guided surface when the main collet and the sub-cylinder are opened and closed can be reduced, and the reduction of the guiding precision of the sub-clamp to the axial direction of the main collet can be suppressed.

In the present invention, it is preferable that a main step portion is provided on an inner circumference of the main collet, and a pair of a pair of the main collet is formed in the axial direction on the outer circumference of the sub-cylinder The side stepped portion is in contact with the main-side stepped portion by the sub-stepped portion, and the main collet is prevented from falling off toward the front end side in the axial direction with respect to the main collet. According to this configuration, by the engagement structure between the main step portion and the sub step portion, the sub-clamp is prevented from falling off toward the front end side in the axial direction with respect to the main collet, in particular, when the material to be gripped is taken out ( For example, when the material to be gripped is ejected by the ejector pin or the like, it is possible to prevent the sub-clamp from falling off in the inner collet. Further, in the case where the above-described axial direction spring is provided, when the material to be gripped is released, the sub-cylinder is spring by the axial direction Returning to the blocking position, the secondary collet can be set to the initial position from time to time with respect to the main collet before insertion of the gripped material. Further, the blocking and detaching structure of the main collet to the main collet is not limited to the configuration of the main step portion and the sub step portion, and may be separately formed by the collet device and the collet chuck in the working machine. The components are provided, and as a result, the secondary collet can be held in the configuration of the main collet.

In the present invention, it is preferable that at least one of the main-side inclined surface of the main collet and the sub-side inclined surface of the sub-cylinder is formed with a groove that intersects with the axial direction. By providing the groove, the corner portion on which the inclined surface on one side is generated bites the other inclined surface, so that the positional deviation in the axial direction between the main collet and the sub-clamp in the gripped state can be reduced.

A chuck device according to the present invention is characterized by comprising: the collet chuck; and an acting member which is movably formed in an axial direction and pressurizes the main collet in an axial direction It is caused to expand and contract in the radial direction (resulting in the diameter reduction of the inner circumference). According to this configuration, the pressing portion of the main collet is pressurized by the acting member to operate the main collet, and the sub-clamp is also inverted by the main-side inclined surface and the sub-side inclined surface. The fitting structure is used to operate. For example, the main cylinder is reduced in diameter by the pressurization of the acting member, whereby the secondary collet is also reduced in diameter and gripped by the gripping material. In this case, the pressure-receiving surface of the main collet is a surface that pressurizes the working member in the axial direction in order to enlarge and contract the inner diameter, and is configured to be tapered toward at least one side in the axial direction. Or inverted cone. In this case, it is preferable that the sub-cylinder clip is held in the main collet by being blocked from being displaced from the front end side in the axial direction, and the collet apparatus further includes the main collet An axial direction spring that adds potential energy to the sub-cylinder clip toward the front end side in the axial direction.

Next, the method for producing a processed article of the present invention is to process the material to be processed while holding the material to be processed by a chuck device. A method of molding a processed product, the chuck device comprising: the collet chuck; and an acting member configured to be movable in an axial direction and facing the main cylinder in an axial direction The clamp is pressurized to cause expansion and contraction in the radial direction (for example, a diameter reduction of the inner circumference), and the main collet and the sub-cylinder are clamped by disposing the acting member in the release driving position. The canceled state is set, and the material to be processed is attached to the inner peripheral side of the sub-cylinder, and then the acting member is placed at the grip driving position, and the main collet and the sub-cylinder are set in the gripping state. And processing the above-mentioned materials to be processed.

In the present invention, it is preferable that the sub-cylinder clip is held by the main collet while being blocked from the front end side in the axial direction, and the collet apparatus further includes an axial direction spring. The axial direction spring biases the secondary collet toward the front end side in the axial direction with respect to the main collet. According to this configuration, the secondary collet is prevented from coming off toward the front end side in the axial direction, and the potential energy is added to the front end side in the axial direction by the axial direction spring. When the material to be processed is released, the sub-cylinder is supported by the axial direction spring. The gauge is returned to the blocking position, so that the secondary collet can be set to the initial position with respect to the main collet before the insertion of the material to be processed. Therefore, when the material to be processed is introduced, the precision of the introduction position of the material to be processed in the axial direction of the sub-clamp can be improved, and as a result, the processing accuracy can be improved. Further, of course, when the material to be processed is taken out (for example, when the material to be gripped by the ejector pin or the like is discharged), it is possible to prevent the sub-clamp from falling off in the inner collet. Furthermore, the blocking mechanism of the secondary collet to the main collet may be provided between the main collet and the main collet as described above, or may be between the other components and the collet device. Or set separately in the working machine and the collet chuck.

In the present invention, it is preferable that the sub-cylinder clip has a state in which the material to be processed is locked and positioned from the base end side in the axial direction when the state is released. a position locking portion (for example, a base end side in the axial direction of the grip surface), and the material to be processed is in contact with the positioning locking portion when being attached to the inner circumferential side of the sub-clamp In the state, it is held by the above-mentioned sub-clip. According to this configuration, since the material to be processed is held by the sub-clip in a state in which the material to be processed is in contact with the positioning locking portion, the position of the material to be processed in the axial direction of the sub-clamp can be set to be constant, thereby reducing the position. The dimensional dimension of the product obtained by processing the material to be processed is not uniform, and the shape accuracy of the axial direction of the product can be improved.

In this case, the chuck device further includes an axial direction spring that adds a potential energy to the sub-cylinder toward the front end side in the axial direction with respect to the main collet, and the material to be processed is attached to the sub-cylinder At the time of clamping, the material to be applied is brought into contact with the positioning locking portion, and the axial direction spring is compressed, and is held by the sub-clamp. According to this configuration, since the axial direction spring adds a potential energy to the sub-cylinder on the front end side in the axial direction, it is only required to set the material to be processed from the front end side of the sub-clamp and to compress the axial direction spring, that is, The state in which the material to be processed is in contact with the positioning locking portion can be maintained, so that the positioning state of the material to be processed when being held by the sub-clamp can be surely obtained, and the positional accuracy of the material to be processed in the axial direction of the sub-clamp can be further improved. .

In the present invention, it is preferable that the first step includes: mounting the material to be processed on the main shaft and performing front processing; and in the second step, providing the material to be processed after the front surface processing is completed The back spindle of the chuck device is configured to hold the material to be processed by the chuck device on the back spindle; and the third step is to perform back processing on the workpiece to be processed on the back spindle. According to this method, even when a machining force is applied to the workpiece at the base end side in the axial direction in the back surface processing, if the workpiece is to be moved toward the base end side in the axial direction due to the machining force, the sub-cylinder a sliding structure between the auxiliary side inclined surface and the main side inclined surface between the clip and the main collet, It is still possible to increase the holding force of the material to be processed, and as a result, the positional deviation of the base end side of the material to be processed in the axial direction can be avoided. Therefore, the machining accuracy in the axial direction of the material to be processed can be improved, and the damage generated between the workpiece and the holding surface of the sub-clamp can be reduced. Further, it is possible to prevent the positional deviation of the material to be processed in the axial direction during the back surface processing, and it is also possible to reduce the machining deviation in the axial direction between the front processed portion and the back processed portion of the processed product.

Further, another collet chuck according to the present invention includes: a cylindrical main collet; and a cylindrical sub-clamp which is sandwiched in the axial direction with respect to the main cylinder on the outer peripheral side of the main collet Removably arranged, the main collet has a plurality of slots extending in the axial direction, and a pressed surface is disposed on the inner circumference and is for pressurizing the outer diameter of the main collet And a main-side inclined surface provided on the outer circumference and configured to be tapered toward the front end side in the axial direction, the sub-cylinder having a plurality of slots extending in the axial direction; a gripping surface provided on the outer circumference for holding the material to be gripped; and a side inclined surface provided on the inner circumference and configured to engage the tapered surface of the main side inclined surface shape. That is, the collet chuck holds the collet chuck of the inner diameter holding type of the inner diameter of the material to be gripped.

Preferably, the present invention further includes an axial direction spring that adds a potential energy to the front end side of the main collet with respect to the axial direction. Further, it is preferable that the sub-cylinder has a positioning locking portion that locks the grasped material from the proximal end side in the axial direction when the position is in the released state (for example, the axial direction of the grip surface) The base end side). Moreover, it is preferable that the grip surface of the sub-cylinder clip has a frustum-shaped surface that is inclined toward the front end side in the axial direction. That is, in the case of the inner diameter holding type, the grip surface is configured to have a taper which is inclined toward the front end side in the axial direction. Further, it is preferable that the main collet has a guide surface extending in the axial direction on the outer circumference, and the sub-cylinder The clip is provided on the inner circumference with a guided surface that is slidably guided to the guide surface and guided in the axial direction. Further, in this case, it is preferable that the groove of the main collet and the groove of the sub-cylinder are formed so as to extend from the front end edge in the axial direction toward the proximal end side, and the guide surface is formed in relation to the main body The side inclined surface is disposed in a region on the proximal end side in the axial direction, and the guided surface is formed in a region on the proximal end side in the axial direction with respect to the secondary side inclined surface. Further, it is preferable that a main-side step portion is provided on the outer circumference of the main collet, and a sub-step portion that is engaged with the main-side step portion in the axial direction is provided on the inner circumference of the sub-cylinder clip. And the secondary side stepped portion abuts against the main-side stepped portion, and the main collet is prevented from falling off toward the front end side in the axial direction with respect to the main collet. Further, it is preferable that the grip surface of the sub-cylinder has an engagement grip portion that protrudes in a radial direction, which makes it possible to grasp skipping. In this case, it is preferable that the positioning locking portion is separated from the proximal end side in the axial direction of the engaging and gripping portion. Further, it is preferable that a groove that faces the axial direction is formed on at least one of the main inclined surface of the main collet and the sub-side inclined surface of the sub-clamp.

This other collet chuck can be used in the above collet device. In other words, in place of the above-described acting member, it is also possible to use an action member that is configured to be movable in the axial direction and pressurize the main collet in the axial direction to expand and contract in the radial direction (the diameter of the outer circumference is increased). . In this case, the pressed surface of the main collet is tapered to at least either side in the axial direction by expanding and contracting the outer diameter by the surface of the acting member pressed in the axial direction. Or inverted cone. In this case, it is preferable that the sub-cylinder clip is held in the main collet by being blocked from being displaced from the front end side in the axial direction, and the collet apparatus further includes the main collet An axial direction spring that adds potential energy to the sub-cylinder clip toward the front end side in the axial direction.

In addition, the chuck device using the above other collet chuck is attached to the present invention. The method for manufacturing a processed product according to the present invention is characterized in that, by disposing the acting member at a release driving position, the main collet and the sub-cylinder are set in a released state, and the material to be processed is installed. The working member is placed on the outer peripheral side of the sub-cylinder, and then the working member is placed at the grip driving position, and the main collet and the sub-cylinder are set in a gripping state, and the workpiece is processed. In this case, it is preferable that the sub-cylinder clip is held by the main collet by being blocked from the front end side in the axial direction, and the collet apparatus further includes the main collet An axial direction spring that adds a potential energy to the secondary collet at the front end side in the axial direction. Further, it is preferable that the sub-cylinder clip has a positioning locking portion that locks the grasped material from the base end side in the axial direction when the position is in the released state (for example, the axial direction of the grip surface) In the base end side, the material to be processed is held by the sub-clip in a state in which it is in contact with the positioning locking portion when mounted on the outer peripheral side of the sub-clamp. In this case, it is preferable that the chuck device further includes an axial direction spring that applies a potential energy to the sub-cylinder toward the front end side in the axial direction with respect to the main collet, and the material to be processed is attached to the The sub-clamp is held by the sub-clip when the material to be applied is brought into contact with the positioning locking portion and the axial direction spring is compressed. Further, in a preferred method, the method further includes the steps of: installing the material to be processed on the main shaft to perform front processing; and in the second step, delivering the material to be processed to complete the front surface processing to the chuck The back main shaft of the apparatus grips the workpiece by the chuck device on the back spindle; and the third step performs back processing on the workpiece to be processed on the back spindle.

Further, in the present invention, the taper refers to a case where the taper is gradually tapered toward the front end side in the axial direction. The inverted taper refers to a case where the base end side in the axial direction is gradually tapered. Further, the cylindrical system mainly refers to a cylindrical shape, but also includes an elliptical cylindrical shape, a long cylindrical shape, and a rectangular tubular shape. The shape of the tube. Further, the frustum-shaped surface refers to a surface having a shape of a side surface of a frustum, and mainly has a truncated cone shape, but further includes an arbitrary frustum shape such as an elliptical frustum shape, a long truncated cone shape, or a square frustum shape.

According to the present invention, a collet chuck, a chuck device, and a method of manufacturing a processed article can be realized, and the following excellent effects can be obtained. By preventing the holding position from being displaced in the axial direction, the shape accuracy of the machined part can be improved and the shape can be reduced. Bad rate.

1‧‧‧ headstock

2‧‧‧ Spindle

3‧‧‧ chuck device

5‧‧‧ Tools

6‧‧‧ Tools

7‧‧‧ Tools

10‧‧‧ collet chuck

10’‧‧‧ collet chuck

11‧‧‧Main collet

11’‧‧‧Main collet

11”‧‧‧Main collet

11a‧‧‧ slotting

11a”‧‧‧ slotting

11b‧‧‧ Pressed surface

11b”‧‧‧ Pressed surface

11c‧‧‧main side inclined surface

11c’‧‧‧ Main side inclined surface

11c”‧‧‧Main side inclined surface

11d‧‧‧ guiding surface

11d’‧‧‧ Guide member

11d”‧‧‧ Guide surface

11e‧‧‧ main side step

11e1‧‧‧ tapered step surface

11e2‧‧‧ vertical step surface

11e’‧‧‧Positioning holes

11e"‧‧‧ end face (Fig. 9(a))

11e”‧‧‧ main side step (Fig. 9(b))

11p‧‧‧Outer Steps

11q1, 11q2‧‧‧ ditch

11r‧‧‧Cylinder

12‧‧‧Separate collet

12’‧‧‧Separate collet

12"‧‧‧Separate collet

12a‧‧‧ slotting

12a"‧‧‧ slotting

12b‧‧‧ Holding face

12b’‧‧‧Card Control Department

12b"‧‧‧ Holding face

12c‧‧‧Side side inclined surface

12c’‧‧‧Side side inclined surface

12c”‧‧‧Side side inclined surface

12d‧‧‧guided surface

12d’‧‧‧ guided face

12d”‧‧‧Guided surface

12e‧‧‧Secondary step

12e’‧‧‧ Locating Pin

12e” ‧ ‧ step surface (Fig. 9(a))

12e”‧‧‧Side-side step (Fig. 9(b))

12s‧‧‧Positioning card

12s’‧‧‧ Positioning card

12s"‧‧‧Positioning card

12t’‧‧‧ carding member

13‧‧‧Axis direction spring

13'‧‧‧Axis direction spring

13”‧‧‧Axis direction spring

14‧‧‧ Spring support

14'‧‧‧Spring Support

20‧‧‧ chuck device

20”‧‧‧ chuck device

21‧‧‧Chuck sleeve

21"‧‧‧1st acting member

21a‧‧‧ longitudinal groove

21a”‧‧‧ Pressurized surface

21b‧‧‧ Pressurized surface

21b"‧‧‧Sliding shaft

22‧‧‧Cover Nuts

22"‧‧‧2nd member

22a‧‧‧ Opening

22a”‧‧‧ Pressurized surface

22b‧‧‧ positioning surface

22b”‧‧‧ Guide surface

23‧‧‧ Keep the spring

24‧‧‧ Spring support

25‧‧‧Top sales

31‧‧‧Back spindle head

32‧‧‧ Spindle (back spindle)

W‧‧‧Workpiece

W’‧‧‧Workpiece

W"‧‧‧Workpiece

W0‧‧‧ raw materials

W1‧‧‧ intermediate workpiece

W2‧‧‧Products

Wi‧‧‧ shaft hole

Wo‧‧‧ peripheral envelope shape

Wp‧‧‧Small end

Ws‧‧‧ peripheral thread construction

Ws’‧‧‧The Great Trails Department

Fig. 1 is a cross-sectional view (c) showing a front view (a), a longitudinal sectional view (b), and an example of a workpiece corresponding to the collet chuck, showing the structure of the first embodiment of the collet chuck of the present invention.

Fig. 2 is a front view (a) and a longitudinal sectional view (b) showing the main collet of the first embodiment.

Fig. 3 is a front view (a), a B-B longitudinal sectional view (b) and a side view (c) showing the sub-clamp according to the first embodiment.

Fig. 4 is an exploded perspective view showing the structure of the embodiment of the chuck device of the present invention including the collet chuck of the first embodiment.

Fig. 5 is a longitudinal sectional view showing an internal configuration example of the same chuck device.

Fig. 6 is a longitudinal sectional view (a) showing a released state of the same chuck device, and a longitudinal sectional view (b) showing a gripping state.

Fig. 7 is a longitudinal sectional view (f) showing the steps (a) to (e) of the embodiment of the method for producing a processed article of the present invention and a structural example showing the workpiece.

Fig. 8 is a front view (a) showing a second embodiment of the collet chuck according to the present invention, showing a longitudinal sectional view (b) in a released state, a longitudinal sectional view (c) showing a state in a moving state in a gripping state, and display holding. A longitudinal section view of the state (d).

Fig. 9 is a longitudinal sectional view (a) showing a released state of a third embodiment of the collet chuck having another collet chuck according to the present invention, and a longitudinal sectional view (b) showing a gripped state.

[First Embodiment]

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, a first embodiment of a collet chuck will be described with reference to Figs. 1 to 3 . The collet chuck 10 of the present embodiment includes a main collet 11 having a cylindrical shape (a cylindrical shape in the illustrated example) as shown in FIGS. 1 and 2, and is housed inside the main collet 11 As shown in FIGS. 1 and 3, the distal end side portion in the axial direction is integrally formed into a cylindrical shape (a cylindrical shape in the illustrated example), and is housed inside the main collet 11 and disposed in An axial direction spring 13 on the proximal end side in the axial direction of the sub-clamp 12; and a spring support attached to the proximal end in the axial direction of the main collet 11 to support the axial direction spring 13 from the proximal end side in the axial direction 14.

The main collet 11 has a plurality of slots (three in the illustrated example) that are disposed around the axis, and the slots 11a are formed so as to extend from the front edge toward the base end side (the right side of the drawing) from the axial direction. The range up to the middle position. The base end portion of the slit 11a in the axial direction is an opening portion having a large circular shape (may be an oblong shape or an elliptical shape), and the opening portion is located at a front end side (left side in the drawing) of the axial direction. It is configured as a slit having a certain width. The pressed surface 11b is formed in the outer peripheral portion in the formation region in the axial direction of the slit 11a, and the pressed surface 11b is configured to have an inverted taper (conical shape) inclined toward the proximal end side in the axial direction. The outer peripheral step portion 11p is formed on the front end side of the pressed surface 11b, and the outer peripheral step portion 11p faces the step surface on the proximal end side in the axial direction, and is formed on a vertical surface orthogonal to the axis.

The main collet 11 is configured to be received on the pressed surface 11b The pressing force of the chuck sleeve (acting member) is described, and the inner diameter of the main-side inclined surface 11c at the front end portion in the axial direction is enlarged and reduced. This main-side inclined surface 11c is provided on the inner circumference of a portion located on the most front end side of the main collet 11. In addition, the main-side inclined surface 11c is a truncated cone-shaped surface having a predetermined taper angle in the axial direction, and becomes a reverse tapered shape having a larger inner diameter as it goes toward the front end side in the axial direction of the main collet 11. As shown in Fig. 2, the main-side inclined surface 11c is formed with annular grooves 11q1, 11q2 orthogonal to the axis. Further, a cylindrical surface 11r disposed between the portion and the main-side step portion 11e to be described later is formed in a portion adjacent to the proximal end side in the axial direction of the main-side inclined surface 11c. This cylindrical surface 11r has the same inner diameter as the portion having the smallest diameter of the base end edge in the axial direction of the main-side inclined surface 11c.

A guide surface formed by a cylindrical surface having a certain inner diameter in the axial direction is formed in a region on the inner end side of the main collet 11 and in the axial direction with respect to the main-side inclined surface 11c. 11d. Further, a main step portion 11e is provided between the guide surface 11d and the main-side inclined surface 11c, and the main-side step portion 11e has a step surface facing the base end side in the axial direction. In the case of the illustrated example, the guide surface 11d and the main-side step portion 11e are formed in a region in the axial direction in which the pressed surface 11b is provided on the outer circumference. This region is a region in the main collet 11 which is thicker than the portion which is formed on the proximal end side in the axial direction. Further, as shown in FIG. 2, the step surface of the main-side step portion 11e has a base end side facing the axial direction, and has a tapered stepped tapered step surface 11e1 which is inclined obliquely toward the inner peripheral side; And a vertical step surface 11e2 formed adjacent to the outer peripheral side of the tapered step surface 11e1 and orthogonal to the axis. The tapered step surface 11e1 is connected to the cylindrical surface 11r, and the vertical step surface 11e2 is connected to the above-described guide surface 11d.

The sub-clip 12 is provided with a plurality of slots (three in the illustrated example) surrounding the axis extending from the front end edge in the axial direction toward the base end side. The base end portion of the slot 12a in the axial direction is formed as a large circular (or elliptical or elliptical) opening portion. The portion of the mouth portion located on the front end side in the axial direction is formed in a slit shape having a certain width. In the region of the inner circumference of the sub-cartridge 12 and in the axial direction of the slit 12a, in the example of the drawing, the foremost end side in the axial direction is formed to grip the material to be gripped or the material to be processed (hereinafter, simply referred to as "workpiece" W") holding surface 12b. The grip surface 12b may be a cylindrical surface having a constant inner diameter in the axial direction as long as the outer diameter of the sub-cylinder 12 is reduced by the inner diameter of the sub-cylinder clamp 12. However, in the illustrated example, the grip surface 12b has an inner surface shape of a reverse tapered shape which is expanded toward the front end side in the axial direction. The inner surface shape of the grip surface 12b corresponds to the outer surface shape of the workpiece. In the present embodiment, it is designed to hold the workpiece W having a reverse tapered shape in the front end side in the axial direction. Further, a positioning locking portion 12s is provided on the proximal end side in the axial direction of the grip surface 12b, and the positioning locking portion 12s is inserted into the workpiece W even if the secondary collet 12 is not released by the main collet 11 being locked. When the sub-clip 12 is inside, it can be abutted against the front end thereof and locked and positioned from the base end side in the axial direction.

A sub-side inclined surface 12c that is joined to the main-side inclined surface 11c provided on the main collet 11 is formed in an outer peripheral portion of the sub-clamp 12. In the illustrated example, the secondary side inclined surface 12c is provided at a portion located on the most distal end side of the secondary collet 12. Further, the auxiliary side inclined surface 12c is formed into a truncated cone-shaped surface having a taper angle in the axial direction, and is configured such that the outer end thereof is toward the front end side in the axial direction of the sub-cylinder 12, and the outer diameter is larger. The sub-side inclined surface 12c is formed to have a taper angle substantially the same as that of the main-side inclined surface 11c so as to be in close contact with the main-side inclined surface 11c in a state in which the workpiece W is gripped.

A guide surface formed by a cylindrical surface having a constant inner diameter in the axial direction is formed on the inner circumference of the sub-cylinder 12 and the region on which the sub-side inclined surface 12c is formed in the axial direction. 12d. Further, a sub-step portion having a step surface facing the base end side in the axial direction is provided between the guided surface 12d and the sub-side inclined surface 12c. 12e. In the example of the drawing, the sub-step portion 12e is formed in a truncated cone shape (inverted tapered shape) that is inclined toward the outer end side toward the front end side in the axial direction. In the case of the illustrated example, the guided surface 12d is slidably attached to the guiding surface 11d, whereby the secondary collet 12 is movably guided in the axial direction with respect to the main collet 11. Further, the sub-step portion 12e is formed at a position and a shape to be fitted to the main-side step portion 11e. Specifically, when the main step portion 11e and the sub step portion 12e are fitted, the sub step portion 12e is in close contact with the tapered step surface 11e1 of the main step portion 11e, but the vertical step surface 11e2 is The surface of the sub-step portion 12e is separated from the surface. By the engagement structure of the main-side stepped portion 11e and the sub-stepped portion 12e, the sub-cylinder clip 12 is prevented from falling off at the front end side in the axial direction while being housed inside the main collet 11 .

The workpiece W shown in Fig. 1(c) having an outer shape corresponding to the inner surface shape of the grip surface 12b of the sub-cartridge 12 has a shape elongated in the axial direction and has a base end side in the axial direction. The inclined shape is configured as an outer envelope shape Wo (indicated by a little chain line). For example, as an example of the shape of the outer peripheral surface of the outer circumferential envelope shape Wo, a male screw structure formed around the axis can be cited. Further, a small-diameter end Wp fitted to the positioning locking portion 12s is formed at a proximal end of the collet chuck in the axial direction. Further, a shaft hole Wi is formed which is open at the open end of the front end in the axial direction. For example, as an example of the shaft hole Wi, a hexagonal hole into which a tool such as a wrench is fitted can be cited.

In the collet chuck 10, when the pressure is applied to the pressed surface 11b of the main collet 11 from the proximal end side in the axial direction, the inner diameter of the main inclined surface 11c is reduced, and the sub-cylinder is used by the reduction. The outer diameter of the auxiliary side inclined surface 12c of the clip 12 is reduced to reduce the inner diameter of the grip surface 12b. Therefore, the workpiece W can be held inside the sub-cartridge 12. Further, between the sub-clamp 12 and the spring holder 14, the axial direction spring 13 is housed inside the main collet 11 in a compressed state. With the elastic force of the axial direction spring 13, the main collet 11 is not attached In the released state in which the collet 12 is locked, the sub-clamp 12 is configured such that the guided surface 12d is guided by the guide surface 11d of the main collet 11 to be movable in the axial direction, and the sub-step portion is moved. The 12e is positioned and held at an initial position in contact with (fitting) the main step portion 11e.

Here, the grooves 11q1 and 11q2 provided in the main-side inclined surface 11c are engaged with the auxiliary-side inclined surface 12c by the annular corner portions formed by the installation grooves 11q1 and 11q2 in the gripping state. The positional deviation of the main-side inclined surface 11c and the said secondary side inclined surface 12c in the axial direction is suppressed. However, in the above-described released state, the grooves 11q1, 11q2 do not interfere with the sliding of the main-side inclined surface 11c and the auxiliary-side inclined surface 12c in the axial direction. Further, in the present embodiment, the grooves 11q1 and 11q2 are formed on the main-side inclined surface 11c, but may be formed on the sub-side inclined surface 12c, or may be provided on the main-side inclined surface 11c and the secondary-side inclined surface. Both sides of 12c. Further, in order to obtain the biting action of the corner portion, the groove may be formed to extend in a direction crossing the axial direction.

Further, in the abutting structure of the main-side step portion 11e and the sub-step portion 12e, the sub-step portion 12e is closely adhered to the tapered step surface 11e1 of the main-side step portion 11e, and is formed on the vertical step surface. A gap is formed between the 11e2 and the sub-side step portion 12e. In this manner, the tapered step surface 11e1 formed on the inner peripheral side of the main-side step portion 11e is brought into contact with the sub-step portion 12e, and the sub-clamp 12 is positioned in the axial direction, and is formed on the outer peripheral side. The structure in which the vertical step surface 11e2 is separated from the sub-step portion 12e makes it easy to perform internal processing of the main collet 11, and it is also possible to easily improve the surface accuracy of the tapered step surface 11e1. Further, it is possible to suppress a change in the blocking/detaching position of the sub-clip 12 in the axial direction of the main collet 11 caused by the deformation of the front end portion of the main collet 11 and the sub-clamp 12 when the front end portion is enlarged and contracted in the radial direction. Further, the tapered step surface 11e1 does not have to be tapered, and may be a step surface that corresponds to the surface shape of the sub-step portion 12e and that can be in close contact with the sub-step portion 12e. In addition, the vertical step surface 11e2 does not have to be a vertical surface, only It is sufficient if the surface of the sub-step portion 12e can be separated (not in contact).

4 and 5 show the construction of the chuck device 20 using the collet chuck 10 described above. However, the collet chuck 10 is slightly different from the collet chuck 10 shown in FIGS. 1 to 3, and the grooves 11q1 and 11q2 are not formed, and the step surface of the main step portion 11e is integrally bonded to the step The surface shape of the sub-step portion 12e. That is, in the case of such a configuration, the basic functions and functions are also the same as described above. However, for convenience of explanation, the collet chucks shown in FIGS. 4 and 5 and the components thereof are provided in the same manner as in FIGS. 1 to 3. Symbol.

As shown in Fig. 5, the chuck device 20 is assembled such that the collet chuck 10 is housed in a chuck sleeve 21 that is mounted on a spindle (back spindle) 32 of the machine tool, and is borrowed from the front end side of the axis direction. The cap nut 22 attached to the collet sleeve 21 is positioned on the front end side in the axial direction, and the holding spring 23 is biased from the base end side in the axial direction toward the front end side by a retaining spring 23 such as a coil spring. The spring support 24 shown in FIG. 4 is a stopper that is mounted on the collet sleeve 21 and supports the base end side of the retaining spring 23. Further, the ejector pin 25 shown by the two-dot chain line in Fig. 5 is inserted into the inside of the main collet 11 from the proximal end side in the axial direction. The ejector pin 25 is often in standby at the base end side in the axial direction. When the workpiece W is ejected, it is driven by other mechanisms to protrude toward the front end side in the axial direction, and the workpiece W is directed from the inside of the sub-clamp 12 toward the axial direction. The front end side is protruded and discharged.

The collet sleeve 21 is mounted coaxially with the collet chuck 10 with respect to the main shaft 32. A vertical groove 21a is formed in the outer peripheral portion of the chuck sleeve 21 in the axial direction, and the vertical groove 21a is fitted to the main shaft 32, and is configured to rotate the chuck device 20 integrally with the main shaft 32 about the axis. The chuck sleeve 21 functions as an acting member for expanding and contracting the main collet 11 and the sub-cylinder clip 12 of the collet chuck 10 in the radial direction. An inner peripheral portion on the front end side in the axial direction of the cylindrical chuck sleeve 21 is formed with a truncated cone-shaped (inverted tapered) pressing surface 21b formed to expand toward the front end side in the axial direction. And, the collet sleeve 21 is It moves in the axial direction by a known drive mechanism. When the chuck sleeve 21 is at the position (release drive position) shown in FIG. 6(a), the front end portions of the main collet 11 and the sub-cartridge 12 are in a released state in which they are enlarged toward the outer peripheral side. On the other hand, when the chuck sleeve 21 is moved toward the front end side in the axial direction and is located at the position shown in FIG. 6(b) (holding drive position), the pressurizing surface 21b pressurizes the pressed surface 11b. The main collet 11 and the sub-cartridge 12 are reduced in diameter to be in a gripping state.

The cap nut 22 includes an opening 22a through which the front end portions of the main collet 11 and the sub-clip 12 in the axial direction are passed, and the positioning surface 22b located at the inner edge of the opening of the opening 22a abuts against the main collet 11 outer peripheral step portion 11p. The base end portion of the cap nut 22 is fixed to the main shaft 32 by a screw structure or the like. The collet chuck 10 is positioned in the axial direction by the potential energy added to the front end side in the axial direction by the holding spring 23 in a state of abutting against the positioning surface 22b of the cap nut 22. Further, even when the collet sleeve 21 is moved in the axial direction with respect to the main shaft 32 to open and close the collet chuck 10, the collet chuck 10 is positioned relative to the main shaft 32 and fixed in the axial direction. status.

Further, in Fig. 6(a) showing the released state, in order to emphasize the state in which the main collet 11 and the sub-cartridge 12 are expanded, the grooves 11a and 12a are drawn on a larger scale than actually. However, it is actually a natural state to which no external force is applied, and is configured to such an extent that the holding force is not generated for the workpiece W (not shown). However, even in this released state, as shown in the figure, the pressed surface 11b constituting the main collet 11 abuts against the pressing surface 21b of the collet sleeve 21 or the front end portion of the main collet 11. When the outer circumference abuts against the opening edge of the opening portion 22a of the cap nut 22, the axial offset of the collet chuck 10 or the like can be prevented. At this time, when the sub-side inclined surface 12c of the sub-cylinder 12 abuts against the main-side inclined surface 11c of the main collet 11, the axial shift of the grip surface 12b of the sub-cylinder 12 can be finally avoided. This can bring about the advantage in the manufacturing method described later that the workpiece W can be prevented from being inserted into the chuck device 20 The defect, that is, the workpiece W is not aligned with the front end opening of the grip surface 12b of the sub-cartridge 12, and it becomes impossible to insert the workpiece W into the inside of the sub-cartridge 12.

On the other hand, in Fig. 6(b) showing the gripping state, the workpiece W is inserted into the inside of the sub-cylinder 12 from the front end side (the left side in the drawing) in the axial direction, and the pressing force by the collet sleeve 21 is applied. On the other hand, the workpiece W is gripped by the grip surface 12a of the sub-clip 12 which is reduced in diameter by the main collet 11. In the release state from the release state to the grip state, in the released state shown in FIG. 6(a), when the workpiece W has been inserted into the sub-cartridge 12, the workpiece W abuts on the axis direction of the grip surface 12a. In the positioning locking portion 12s on the proximal end side, the secondary collet 12 compresses the axial direction spring 13 and moves slightly toward the proximal end side in the axial direction. At this time, since the guided surface 12d of the sub-cartridge 12 is guided in the axial direction by the guide surface 11d of the main collet 11, the axial offset of the sub-clamp 12 is hardly generated. Thereafter, as shown in FIG. 6(b), the workpiece W is gripped by the grip surface 12b by the movement of the chuck sleeve 21. At this time, as shown in FIGS. 1 to 3, when the grooves 11q1 and 11q2 are formed, the corner portions formed by the grooves 11q1 and 11q2 are formed between the main-side inclined surface 11c and the sub-side inclined surface 12c. The bite is shifted to reduce the positional deviation of the sub-clip 12 from the release state toward the grip state in the axial direction of the main collet 11. The same applies to the case where the groove is provided on the sub-side inclined surface 12c.

In the present embodiment, since the workpiece W is configured to have an inverted taper which is inclined toward the proximal end side in the axial direction, the grip surface 12b of the sub-cylinder 12 is configured to be inverted in a tapered shape toward the front end side in the axial direction, that is, It is in a state of being easily moved toward the front side in the axial direction. Therefore, if the workpiece W is subjected to drilling or broaching from the front end side in the axial direction in the holding state shown in FIG. 6(b), the base end side in the axial direction is applied to the workpiece W. The machining force is caused by the impact of the fluctuation of the machining force and the holding force of the gripping surface supplied from the reverse taper, and the workpiece W may be displaced in the front end side in the axial direction. Further, although it is different from the state of the embodiment, the workpiece W is not When the positioning locking portion 12s is positioned on the proximal end side in the axial direction, regardless of whether the grip surface 12b or the workpiece W is inverted tapered or tapered or cylindrical, by applying the above-described machining force, It is possible to cause the workpiece W to be displaced from the position on the base end side in the axial direction.

However, in the present embodiment, the sub-side inclined surface 12c of the sub-cylinder 12 is formed into a reverse tapered shape and has a fitting structure of a reverse tapered shape joined to the main-side inclined surface 11c of the inverted conical shape of the main collet 11. When the workpiece W is to be moved toward the proximal end side in the axial direction by the application of the above-described machining force, the secondary collet 12 is also moved toward the proximal end side in the axial direction with respect to the main collet 11 at this time. In the tapered fitting structure, since the gripping force applied to the workpiece W by the grip surface 12b is increased, the positional deviation of the workpiece W in the axial direction can be suppressed (in particular, since the gripping surface 12b and the workpiece W are reversely tapered) The shape is caused by the positional deviation of the front end side in the axial direction). At this time, as shown in FIG. 1 to FIG. 3, when the grooves 11q1 and 11q2 are formed, the corner portions formed by the grooves 11q1 and 11q2 are formed between the main-side inclined surface 11c and the auxiliary-side inclined surface 12c. The biting can further reduce the positional deviation of the sub-clamp 12 from the axial direction of the main collet 11 due to the above-described machining force. The same applies to the case where the groove is provided on the sub-side inclined surface 12c.

Further, when the positioning locking portion 12s is provided on the grip surface 12b as in the present embodiment, when the workpiece W is inserted into the sub-cartridge 12 in the released state of the chuck device 20, the workpiece W is used. Abutting on the positioning locking portion 12s, the positioning is performed on the base end side in the axial direction, and in the positioning state, the workpiece W is held by the secondary collet 12, so that the axial direction of the workpiece W to the sub-clip 12 can be increased. Positional accuracy and its reproducibility. In particular, by adding the potential energy to the sub-cartridge 12 with respect to the front end side of the main collet 11 in the axial direction with respect to the main collet 11, the positioning accuracy of the workpiece W and the sub-cylinder 12 in the axial direction can be further improved. Therefore, by using the machining reference of the workpiece W as the sub-clamp 12, the machining accuracy in the axial direction of the workpiece W can be improved, and the reproducibility of the machining shape can be improved.

7(a) to 7(e) show a method of processing a workpiece W which can effectively use the collet chuck 10 of the embodiment or the chuck device 20, or a product manufactured by processing the workpiece W. Step diagram of the manufacturing method. The spindle head 1 is equipped with a spindle 2, and the material W0 of the workpiece W is gripped by a chuck device 3 provided at the tip end of the spindle 2. The material W0 is, for example, a round bar material, or may be a material having a predetermined length corresponding to the workpiece W, or may be a long-sized material which is premised on the use of a spindle-moving automatic lathe (Swiss-type automatic lathe). At this time, in order to improve the processing precision, the use of the guide sleeve device 4 (broken line in the figure) is particularly suitable for the case of using the above-described long-sized material.

As shown in Fig. 7(a), the material W0 is processed by a suitable tool 5 while being held by the spindle 2. In the case of this embodiment, the front end of the raw material W0 is processed into a taper shape, and thread processing or the like is performed as needed. For example, in the case of manufacturing a dental implant material (dental implant fixture, dental implant abutment, etc.), the outline shape of the outer surface of the product is first formed, and then The detailed structure of the outer surface, for example, an external thread structure (self-tapping screw, etc.) is molded. The cross-sectional shape of the product workpiece W2 composed of the dental implant material or the like is shown in Fig. 7(f), and will be described later in detail. In most cases, since the outline shape of the outer surface of the dental implant material has a taper shape, the outer surface of the workpiece W0 is processed into a taper as shown in Fig. 7(b).

Here, as shown in FIG. 7(b), the main shaft 32 mounted on the rear headstock 31 and the main shaft 2 are disposed on the same axis, and the chuck device 20 is placed at a position facing the material W0. Furthermore, the rear spindle mechanism including the spindle 32 is preferably movably disposed in the machine tool together with the spindle 2 as is well known, but may be disposed on and with the spindle 2 as long as the relative positional accuracy is ensured. On other devices with different devices.

Next, as shown in FIG. 7(c), the rear headstock 31 is moved in the axial direction. The front end portion of the raw material W0 held by the main shaft 2 is inserted into the sub-cartridge 12 of the chuck device 20 in the released state shown in Fig. 6(a). Here, instead of moving the rear headstock 31, the headstock 1 may be moved, or the back headstock 31 may be moved together with the spindle head 1. Further, as described above, when the positioning locking portion 12s is provided on the grip surface 12b of the sub-cartridge 12, the front end portion of the material W0 abuts against the positioning locking portion 12s, as shown in Fig. 6(b), The collet 12 is press-fitted slightly toward the base end side in the axial direction. At this time, since the sub-clamp 12 is biased toward the front end side in the axial direction by the axial direction spring 13, the front end portion of the material W0 is maintained in contact with the positioning locking portion 12s.

On the other hand, when the positioning locking portion 12s is not provided in the sub-cartridge 12, the depth of insertion of the material W0 into the sub-cartridge 12 is set in accordance with the positional relationship between the main shaft 2 and the main shaft 32. At this time, the position in the axial direction of the grip surface 12b of the front end portion of the material W0 is based on the initial position of the sub-clip 12 positioned by the axial direction spring 13 in the released state, and based on the spindle 2 and The relative spacing of the axes 32 in the axial direction is determined. In the case where the positioning locking portion 12s is not provided, for example, as in the present embodiment, the grip surface 12b has an inverted cone shape corresponding to a shape other than the front end portion and the rear end portion of the workpiece W. However, a case where there is no portion that reflects the shape of the small-diameter end Wp of the workpiece W may be cited. Further, in the case where the entire workpiece W is not in an inverted tapered shape, and at least a portion of the axial direction has a cylindrical portion, the holding surface of the cylindrical surface for holding the cylindrical portion may be formed. 12b.

As described above, after the raw material W0 is inserted and positioned by any of the above methods, the chuck device 20 is moved to the grip state. That is, the chuck sleeve 21 is driven in the axial direction, and the main collet 11 and the sub-cylinder clip 12 are reduced in diameter, and the front end portion of the raw material W0 is held as shown in Fig. 6(b). In this state, as shown in FIG. 7(c), the main shaft 2 and the rear main shaft 32 are simultaneously rotated, and the tool 6 such as a cutting tool or the like is used as a raw material. W0 will be cut off before the main surface processing. The front end portion is an intermediate workpiece W1 that has been subjected to main surface machining. Fig. 7 (d) shows a state in which the front spindle main shaft 1 is separated from the main shaft stage 1 in a state where the chuck device 20 of the rear spindle 32 grips the workpiece W1.

Thereafter, as shown in FIG. 7(e), the intermediate workpiece W1 of the chuck device 20 held by the back spindle 32 is subjected to back surface processing. The type and aspect of the back surface processing are not particularly limited. For example, as shown, the processing is performed on the base end side in the axial direction, that is, the drill, the broach, etc., which are shown as the tool 7 A punching process is performed on the cut surface of the intermediate workpiece W1, or a tool engagement structure such as a hexagonal hole is formed. However, the intermediate workpiece W1 is not subjected to the processing of directly applying the machining force to the base end side in the axial direction of the chuck device 20 as shown in the drawing, and is formed by a cutting tool or the like (self-clamping device). In the turning process performed in the case where the workpiece W1 is conveyed toward the base end side in the axial direction, the machining force toward the base end side in the axial direction is also indirectly applied to the workpiece. W1.

As described above, when the machining force toward the base end side in the axial direction is applied to the intermediate workpiece W1, the force toward the proximal end side in the axial direction is also transmitted to the sub-clamp 12, but if the force is used to cause the sub-clamp 12 to move toward the base end side in the axial direction, the gripping surface 12b of the sub-cylinder 12 is further reduced in diameter by the fitting structure of the inverted tapered shape of the main-side inclined surface 11c and the sub-side inclined surface 12c, and the intermediate workpiece W1 Since the holding force is increased, the positional deviation of the intermediate workpiece W1 in the axial direction of the sub-clamp 12 and the positional deviation of the sub-clamp 12 itself in the axial direction can be suppressed. Further, it is possible to prevent the damage of the intermediate workpiece W1 caused by the positional deviation of the outer surface of the holding surface 12b. This effect is formed so that the front end side of the main collet 11 and the sub-column 12 in the axial direction of the slits 11a and 12a extends toward the proximal end side, so that the main collet 11 and the sub-clamp are generated due to the above-described machining force. The reduction diameter of 12 acts on the proximal end portion of the axial direction to become stronger at the front end portion, and can be more improve.

In particular, in the case of the present embodiment, the outer circumferential envelope shape Wo of the intermediate workpiece W1 is configured to be an inverted tapered shape inclined toward the proximal end side in the axial direction, and correspondingly, the holding surface 12b of the secondary collet 12 is configured as An inverted cone that is inclined toward the front end side in the axial direction. Therefore, even in the case where the positioning locking portion 12s is provided on the grip surface 12b, the gripping state of the intermediate workpiece W1 which is fundamentally held by the grip surface 12b of the sub-cartridge 12 is unstable, and the holding force is When the component on the front end side in the axial direction is subjected to an impact, there is a possibility that the intermediate workpiece W1 is displaced from the position on the front end side in the axial direction. Further, for the same reason as described above, when the fitting structure of the inverted tapered shape of the main-side inclined surface 11c and the auxiliary-side inclined surface 12c is hit, the secondary collet 12 is generated in the axial direction with respect to the main collet 11 The position offset of the front end side. However, in the present embodiment, even when the impact is as described above, the gripping force of the grip surface 12b of the sub-cylinder 12 to the intermediate workpiece W1 is increased for the above-described reason, and the fitting structure of the inverted taper is increased. The locking force is also increased, so that the positional deviation of the intermediate workpiece W1 and the secondary collet 12 can still be avoided. Needless to say, even if the positioning locking portion 12s is not provided on the grip surface 12b and the intermediate workpiece W1 is displaced from the position on the proximal end side in the axial direction, the positional displacement can be suppressed.

When the collet chuck 10 shown in FIGS. 1 to 3 is used, the corners formed by the grooves are opposed by the grooves 11q1 and 11q2 of the main-side inclined surface 11c in the gripped state. The sub-side inclined surface 12c is bitten, so that the positional deviation of the sub-clamp 12 from the axial direction of the main collet 11 is less likely to occur. This is also the same in the case where the groove is provided on the sub-side inclined surface 12c.

Finally, the product workpiece W2 which has finished the back surface processing is discharged from the chuck 20 by using the above-described ejector pin 25 or the like. As an example of the product workpiece W2, as shown in Fig. 6 (f), a dental implant material is exemplified. The workpiece W2 has an axial direction The outer peripheral surface of the tapered shape is formed, and the outer peripheral thread structure Ws such as a self-tapping screw is formed on the outer peripheral surface. Further, the base end in the axial direction has a small-diameter end Wp having a convex curved surface. These outer circumferential envelope shapes, the outer peripheral thread structure Ws, and the small diameter end Wp are formed by the above-described main surface processing. Further, the length of the product workpiece W2 in the axial direction is determined by the cutting process when the spindle 2 is delivered to the rear spindle 32. In the state where the back main shaft 32 is held by the chuck device 20, the cutting process is performed based on the sub-cartridge 12 of the chuck device 20, whereby the length in the axial direction can be made highly accurate, and The matching with the shape (shaft hole Wi) formed by the back surface processing is improved. Further, the product workpiece W2 is formed with a shaft hole Wi that is open at the end side of the end side in the axial direction. This shaft hole Wi is formed by the above-described back surface processing.

[Second Embodiment]

Next, a second embodiment different from the collet chuck 10 will be described with reference to Fig. 8 . The collet chuck 10' shown in Fig. 8 basically has the main collet 11', the axial direction spring 13', and the spring supporter 14' similar to the above-described first embodiment, but is disposed inside the main collet 11'. The configuration of the sub-clamp 12' or the like is different. The sub-clamp 12' of the present embodiment is similar to the above in that the sub-side inclined surface 12c' is in close contact with the main-side inclined surface 11c', and the main-side inclined surface 11c' is provided in the main collet 11' In the axial direction of the distal end side, the engagement grip portion 12b' protruding from the outer peripheral side toward the inner peripheral side is formed on the front end side in the axial direction of the sub-clamp 12', and is a portion corresponding to the grip surface 12b. The engagement grip portion 12b' protrudes toward the inner peripheral side from the inner peripheral surface on the proximal end side in the axial direction of the sub-cartridge 12'. This configuration makes it possible to grasp the so-called skipping so that it can hold the large-diameter portion Ws having a large outer diameter protruding toward the outer peripheral side on the proximal end side in the axial direction as shown in the figure. 'The shape of the workpiece W'. In other words, in the sub-clip 12', when the workpiece W' is inserted into the inner peripheral side of the engaging and gripping portion 12b', the engaging and gripping portion 12b' can be positioned over the large-diameter portion Ws'. A portion of the workpiece W' on the front end side in the axial direction is gripped.

Further, in the present embodiment, the locking member 12t' is fixedly attached to the proximal end side of the sub-clamp 12' in the axial direction from the engaging and gripping portion 12b'. This locking member 12t' is attached to the base end portion of the sub-cartridge 12' by screwing or the like in the illustrated example. A positioning locking portion 12s' that abuts on the workpiece W' and is positioned in the axial direction is formed at the front end in the axial direction of the locking member 12t'. The positioning locking portion 12s' is disposed at a position separated from the proximal end side in the axial direction with respect to the engaging and gripping portion 12b' so as to accommodate the large diameter portion Ws' of the workpiece W'.

A cylindrical guide member 11d' is attached to the inside of the main collet 11' and on the proximal end side in the axial direction. In the inside of the guide member 11d', the guided surface 12d' provided on the outer peripheral surface of the base end portion of the sub-clamp 12' is slidably guided in the axial direction. Further, the sub-cartridge 12' is housed inside the guide member 11d', and is axially oriented by a spring-loaded spring 13' supported by a spring support 14' attached to the base end of the main collet 11' Additional potential energy is added to the front end side in the axial direction. A positioning pin 12e' is attached to the base end portion of the sub-clip 12', and the positioning pin 12e' is inserted into the positioning hole 11e' provided in the guiding member 11d'. In the released state of the collet chuck 10' shown in FIG. 8(b), the sub-clamp 12' is opposed to the main cylinder by the positioning pin 12e' abutting on the front end edge of the positioning hole 11e' in the axial direction. The front end side of the clip 11' in the axial direction is positioned and blocked to cause a state of falling off.

When the workpiece W' is inserted into the collet chuck 10' in the released state shown in FIG. 8(b), and the workpiece W' is pressed into the positioning locking portion 12s', the workpiece W' is further pressed. Then, as shown in Fig. 8(c), the axial direction spring 13' is compressed on the one hand to move the secondary collet 12' toward the proximal end side in the axial direction. At this time, the sub-side inclined surface 12c' of the sub-cylinder clamp 12' is guided by the main-side inclined surface 11c' of the main collet 11', and the sub-clamp 12' is reduced in diameter, and the above-described engaging and gripping portion 12b' is approached. The front end side of the workpiece W' is larger than the large diameter portion Ws' in the axial direction The shape of the small is held outside the part. Further, by the press-fitting of the workpiece W', the positioning pin 12e' abuts against the base end edge of the positioning hole 11e' in the axial direction, and is positioned. Then, when the pressed surface 11b' of the main collet 11' is pressurized by the acting member (not shown) similar to that of the first embodiment, the main collet 11' is reduced in diameter and the main side is inclined. The surface 11c' locks the auxiliary side inclined surface 12c'. Therefore, as shown in Fig. 8(d), the engaging and gripping portion 12b' of the secondary collet 12' grips the workpiece W'.

In the present embodiment, in the holding state shown in Fig. 8(d), when the machining force and the impact on the base end side in the axial direction are applied to the workpiece W', even if the sub-clamp 12' is intended to be opposed to the main collet 11' moves toward the base end side in the axial direction, and by the fitting structure of the inverted tapered shape of the main-side inclined surface 11c' and the auxiliary-side inclined surface 12c', the holding force is increased, so that the axial direction of the workpiece W' can be prevented. The positional offset can also avoid the damage of the workpiece W' caused by the positional deviation. In the illustrated example, in the gripping state, the positioning pin 12e' abuts against the base end edge of the positioning hole 11e' in the axial direction, and the sub-cartridge 12' is positioned in the axial direction with respect to the main collet 11'. In the state, when the above-described machining force and impact are applied, the holding force can be temporarily increased even if the sub-clamp 12' hardly moves in the axial direction. However, it may be configured to have a gap between the positioning pin 12e' and the base end edge of the positioning hole 11e' in the axial direction, or the positioning hole 11e' does not have an opening edge at the base end side in the axial direction, so that the sub-clamp 12' can be moved toward the base end side in the axial direction with respect to the main collet 11' even in the gripping state.

[Third embodiment]

Figure 9 is a longitudinal cross-sectional view showing the released state (a) and the gripped state (b) of the chuck device 20" according to the third embodiment of the collet chuck. The collet chuck is held inside the workpiece from the inside. The inner diameter side and the outer circumference side of the inner diameter side of the diameter of the collet chuck of the first embodiment are reversed. The main collet 11" is configured to surround the axis. a plurality of slots 11a" cylindrical (cylindrical), and have an inner circumference a tapered surface and a tapered pressure-receiving surface 11b". The pressed surface 11b" is formed on the front end side of the inverted tapered portion (cone-shaped portion) formed on the front end side in the axial direction, and is formed on the pressed surface portion The base end side of the tapered end (conical shape) on the proximal end side in the axial direction is constituted by the pressurizing surface portion, and is pressurized by the pressurizing surfaces 21a" and 22a" of the acting members to be described later. On the other hand, a main-side inclined surface 11c" having a tapered shape (a truncated cone shape) inclined toward the front end side in the axial direction is formed on the outer circumference of the main collet 11". Further, the collet chuck of the illustrated example includes a slit 11a" formed from the front end edge in the axial direction and extending toward the proximal end side, and a slit 11a formed from the base end edge in the axial direction and extending toward the front end side. (not shown), having a double-groove collet structure that is alternately formed around an axis, but may also be a single-groove collet having only a groove formed from the front end edge of the axial direction and extending toward the proximal end side. structure.

In the chuck device 20" of the present embodiment, the action member for driving the main collet 11" includes a first acting member 21" having a reverse tapered shape (cone) inclined toward the proximal end side in the axial direction. The pressing surface 21a" of the table-like shape includes a sliding shaft portion 21b" extending toward the proximal end side in the axial direction, and a second acting member 22" for the sliding shaft portion 21b of the first acting member 21" a cylindrical (cylindrical) member that is movably inserted in the axial direction, and has a tapered (cone-shaped) pressing surface 22a" inclined toward the front end side in the axial direction, and is at the base end in the axial direction. The side has a guide surface 22b" formed by a cylindrical surface of the same diameter. The second acting member 22'' is fixed to a main shaft (not shown), and the first acting member 21'' can be changed in the axial direction by a driving mechanism (not shown).

In the present embodiment, a cylindrical (cylindrical) secondary collet 12" is disposed on the outer peripheral side of the main collet 11". The sub-clamp 12" has a plurality of slits 12a" formed around the front end edge of the axial direction and extending toward the proximal end side around the axis. Further, on the inner circumference of the sub-cartridge 12", a sub-side inclined surface 12c" which is in close contact with the main-side inclined surface 11c" provided on the outer circumference of the main collet 11" is formed, and the sub-side inclined surface 12c" is formed as a Tilting the front end side in the axial direction The face of the cone (conical shape). A base end portion extending in a cylindrical shape is formed in a region where the slit 12a" is not formed on the proximal end side in the axial direction of the sub-cartridge 12", and the inner surface of the base end portion is as shown in Fig. 9(a) The guide surface 12d" guided by the guide surface 22b" of the second acting member 22" is shown. Further, the base end portion of the sub-clamp 12" is provided at the base end portion and is provided in the main collet The step surface 12e" of the end surface 11e" of the base end in the axial direction of the 11" is abutted against the step surface 12e" by the end surface 11e", and the sub-clamp 12" is axially oriented with respect to the main collet 11" The front end side is positioned and blocked to be detached. Further, the sub-clamp 12" is biased toward the front end side in the axial direction by the axial direction spring 13" disposed on the proximal end side in the axial direction.

In the present embodiment, the grip surface 12b" provided on the outer circumference of the sub-cartridge 12" is formed by matching the shape of the inner diameter portion of the workpiece W". In the illustrated example, the grip surface 12b" is simply drawn as a circle. Tube surface. However, depending on the shape of the inner circumference of the workpiece W", for example, the grip surface 12b" may be formed into a tapered (cone-shaped) surface that is inclined toward the front end side in the axial direction. According to this configuration, the same operational effects as those of the first embodiment having the above-described grip surface 12b can be obtained. The base end side in the axial direction of the grip surface 12b" is provided with a positioning locking portion 12s" formed as a step surface that protrudes from the outer peripheral side of the grip surface 12b". The workpiece W" is mounted on the front side from the axial direction. When the outer collet 12" is on the outer peripheral side, the positioning locking portion 12s" abuts against the end edge of the workpiece W" to position the workpiece W" in the axial direction.

In the present embodiment, the workpiece W" is attached to the outer circumference of the sub-cartridge 12" from the front end side in the axial direction in the released state shown in Fig. 9(a). At this time, the workpiece W" is brought into contact with the positioning locking portion 12s as needed, but at this time, the axial direction spring 13" can be compressed with respect to the main collet 11" so that the sub-clamp 12" is oriented in the axial direction. When the first acting member 21" is moved toward the proximal end side in the axial direction with respect to the second acting member 22", the pressed surface 11b" of the main collet 11" is pressed by the pressing surface 21a. ", 22a" is pressurized, so the main collet 11" is expanded in diameter, and the main-side inclined surface 11c" of the main collet 11" expands the sub-side inclined surface 12c", the sub-cylinder The clip 12" is also expanded in diameter. Thereby, as shown in Fig. 9(b), the grip surface 12b" of the sub-clip 12" holds the inner diameter of the workpiece W" from the inside.

In the present embodiment, in the holding state of the chuck device 20", when a machining force or impact is applied to the workpiece W" from the front end side in the axial direction, the sub-clamp 12" is oriented in the axial direction with respect to the main collet 11". The base end side is moved, but by the fitting structure of the tapered shape of the main-side inclined surface 11c" and the sub-side inclined surface 12c", the holding force of the holding surface 12b" of the sub-clip 12" to the workpiece W" is increased. Therefore, the positional deviation of the workpiece W" and the sub-clip 12" in the axial direction can be prevented, and the damage of the workpiece W" due to the positional deviation can be suppressed.

Further, as shown by the two-dot chain line in FIG. 9(b), the main collet 11" may be formed in a tubular extending portion extending toward the proximal end side in the axial direction, and the outer periphery of the extended portion may be formed. The surface serves as the guide surface 11d" along which the guided surface 12d" of the sub-clip 12" is guided in the axial direction. At this time, the base end surface of the extension portion may be used as the main The side step portion 11e" is such that the main side step portion 11e" abuts against the sub-side step portion 12e" of the sub-cartridge 12", and the sub-clamp 12" is positioned in the axial direction with respect to the main collet 11" And blocked to produce shedding.

The collet chuck, the chuck device, and the method of manufacturing the processed article of the present invention are not limited to the above-described examples, and various changes can be made without departing from the spirit and scope of the invention. For example, in the second embodiment, the anti-slip structure of the grooves 11q1 and 11q2 shown in Figs. 1 to 3 of the first embodiment, the main-side step portion 11e, and the sub-step portion 12e can be used as the barrier-disconnection structure. In the third embodiment, the above-described anti-slip structure can be used for the corresponding portion.

10‧‧‧ collet chuck

11‧‧‧Main collet

11a‧‧‧ slotting

11b‧‧‧ Pressed surface

11c‧‧‧main side inclined surface

11d‧‧‧ guiding surface

11e‧‧‧ main side step

11p‧‧‧Outer Steps

12‧‧‧Separate collet

12a‧‧‧ slotting

12b‧‧‧ Holding face

12c‧‧‧Side side inclined surface

12d‧‧‧guided surface

12e‧‧‧Secondary step

12s‧‧‧Positioning card

13‧‧‧Axis direction spring

14‧‧‧ Spring support

W‧‧‧Workpiece

Wi‧‧‧ shaft hole

Wo‧‧‧ peripheral envelope shape

Wp‧‧‧Small end

Claims (14)

A collet chuck characterized by comprising: a cylindrical main collet; and a cylindrical sub-cylinder on the inner peripheral side of the main collet, movably arranged relative to the main collet In the axial direction, the main cylinder holder has a plurality of slots extending in the axial direction, a pressed surface disposed on the outer circumference, and being used for expanding and reducing the inner diameter of the main collet The pressurized surface is configured to be tapered or inverted in a direction toward either side of the axial direction; the main-side inclined surface is disposed on the inner circumference and is configured to be inclined toward the front end side in the axial direction And the main side step portion, the sub-cylinder clip has: a plurality of slots extending in the axial direction; a gripping surface disposed on the inner circumference and configured to hold the held material; the secondary side is inclined a surface which is disposed on the outer circumference and configured to be an inverted tapered shape that is joined to the main inclined surface; and a secondary side stepped portion that is engaged with the main side stepped portion in the axial direction by the auxiliary side The sub-step portion of the collet abuts against the main collet Said main side stepped portion with respect to said main collet distal end side of the sub-barrier toward the axial direction of the collet produced off. A collet chuck characterized by comprising: a cylindrical main collet; and a cylindrical sub-cylinder on the inner peripheral side of the main collet, movably arranged relative to the main collet In the axial direction, the main cylinder clamp has: a plurality of slots extending in the axial direction; a pressed surface, which is disposed on the outer circumference, and a pressurized surface for enlarging and reducing the inner diameter of the main collet, that is, a tapered or inverted tapered shape toward either side in the axial direction; and a main-side inclined surface provided at The inner circumference is configured as an inverted taper that is inclined toward the front end side in the axial direction, and the sub-cylinder clip has a plurality of slots extending in the axial direction; and a gripping surface that is disposed on the inner circumference, And for holding the held material; and the auxiliary side inclined surface, which is disposed on the outer circumference, and configured to have an inverted taper that is joined to the main side inclined surface, and the main side inclined surface and the pair of the main collet At least one of the surfaces of the secondary side inclined faces of the collet is formed with a groove that intersects with the axial direction. A collet chuck characterized by comprising: a cylindrical main collet; and a cylindrical sub-cylinder, wherein the outer collet is disposed on the outer peripheral side of the main collet, and is movably disposed relative to the main collet In the axial direction, the main cylinder holder has a plurality of slots extending in the axial direction, and a pressed surface disposed on the inner circumference and being a pressurized surface for expanding and reducing the outer diameter. That is, it is configured to have a tapered or inverted tapered shape toward either side in the axial direction; and a main-side inclined surface which is provided on the outer circumference and which is configured to have a taper toward the front end side in the axial direction in an inclined manner, The secondary collet has a plurality of slots extending in the axial direction; a gripping surface disposed on the outer circumference and configured to hold the held material; and a secondary side inclined surface disposed on the inner circumference and configured to A taper that engages with the inclined surface of the main side described above. The collet chuck according to any one of claims 1 to 3, further comprising an axial direction spring, wherein the axial direction spring is oriented toward the axial direction with respect to the main collet Additional potential energy is added to the front end side. The collet chuck according to any one of claims 1 to 3, wherein the sub-cylinder clip has a position to be locked from a base end side in the axial direction when the position is in a released state And positioning positioning locking portion. The collet chuck according to any one of claims 1 to 3, wherein the grip surface of the sub-cylinder clip is a frustum-shaped surface that is inclined toward the front end side in the axial direction. The collet chuck according to any one of claims 1 to 3, wherein the main collet clip is provided with a guide surface extending in an axial direction, and the sub-cylinder clip is provided with the guide surface The sliding guide is guided to the guided surface in the axial direction. The collet chuck of claim 7, wherein the slot of the main collet and the slot of the sub-cylinder are extended from a front end edge of the main axis toward a base end side The guide surface is formed in a region on the proximal end side in the axial direction with respect to the main-side inclined surface, and the guided surface is formed in the axial direction with respect to the auxiliary-side inclined surface. The area on the base end side. The collet chuck according to claim 3, wherein the main collet is provided with a main step, and the sub collet is provided with a snap in the axial direction with respect to the main step The sub-step portion is abutted against the main-side step portion by the sub-step portion, and the main collet is prevented from falling off toward the front end side in the axial direction with respect to the main collet. The collet chuck according to claim 3, wherein at least one of the main inclined surface of the main collet and the auxiliary inclined surface of the sub-cylinder is formed to intersect with an axial direction. The direction of the ditch. A collet device characterized by comprising: a collet chuck according to any one of claims 1 to 3; and an acting member which is movably formed in an axial direction and is axially The main collet is pressurized to cause expansion and contraction in the radial direction. A method for producing a processed product, wherein the processed material is processed by a chuck device to hold the processed material, and the processed product is molded, wherein the chuck device is A collet chuck according to any one of claims 1 to 3; and a working member which is movably formed in an axial direction and pressurizes the main collet in an axial direction And expanding and contracting in the radial direction, and disposing the above-mentioned acting member at the unlocking position, setting the main collet and the sub-cylinder in a released state, and mounting the workpiece on the above-mentioned workpiece After the sub-clamp is placed, the working member is placed at the grip driving position, and the main collet and the sub-cylinder are set in a gripping state, and the workpiece is processed. The method of manufacturing a processed article according to claim 12, wherein the sub-cylinder clip is held by the main collet by being blocked from the front end side in the axial direction, and the collet device is further provided There is an axial direction spring that applies a potential energy to the front end side of the sub-clamp in the axial direction with respect to the main collet. The method of manufacturing a processed article according to claim 12, wherein the sub-cylinder clip has a position in the released state, and the material to be processed is locked and positioned from a base end side in the axial direction. In the positioning locking portion, the material to be processed is held by the sub-clip in a state of being in contact with the positioning locking portion when being attached to the sub-clamp.