JP5266938B2 - Machine Tools - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a machine tool changeable in a supporting member from a chuck to a center or from the center to the chuck in a shorter time. <P>SOLUTION: At least one of a pair of supporting members supporting both ends of a workpiece is a chuck 40C provided with an insertion hole 43 for inserting the supported workpiece, and a plurality of pawl parts 45 gripping the workpiece from sides of the inserted workpiece. This machine tool includes a center adapter 70 attachable to and detachable from the chuck 40C, having an approximate conical center part 71 at a tip, and an insertion part 72 having a diameter corresponding to the insertion hole 43 at a rear part of the center part 71. The insertion part 72 of the center adapter 70 is inserted in the insertion hole 43 of the chuck 40C, gripped by the pawl parts 45 and centered, to mount the center adapter 70 to the chuck 40C. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a machine tool that supports both ends of a workpiece with a pair of support members and rotates the workpiece around a support shaft passing through the pair of support members.

Conventionally, there are various machine tools for performing processing or the like by rotating the workpiece around a support shaft passing through the pair of support members while supporting both ends of the workpiece with a pair of support members, For example, a cylindrical grinder (see FIG. 1A) that uses an EPS (Electric Power Steering) ball screw as a workpiece to grind the screw portion of the EPS ball screw is also one of the machine tools. In the machine tool 1 shown in FIG. 1A, both ends of a workpiece (hereinafter referred to as a workpiece W) are connected to a chuck 30C provided on the spindle device 30 and a chuck 40C provided on the tailstock device 40. The grinding wheel T is pressed against the workpiece W, the workpiece W is rotated around the support shaft (spindle rotation axis CZ), and the threaded portion K is ground while moving the workpiece W in the direction of the support shaft in synchronization with the rotation. To do.
The example of FIG. 1A is an example in which the threaded portion K of the workpiece W is near the center with respect to the longitudinal direction of the workpiece W. Since both ends of the workpiece W can be gripped by the chuck, the pair of support members are chucked. This is an example of 30C and chuck 40C.
The work W is supported by a chuck support method in which the work W is gripped from the side surface of the work W using a chuck, and a substantially conical center is pressed against the end face of the work W (in this case, the work W There is a center support system (see the center 140C in FIGS. 6A and 6B) for supporting the work W (which is formed with a recess for inserting the center on the end face).
For example, the prior art described in Patent Document 1 discloses a rotary shaft headstock module device in which one of a pair of support members is a chuck and the other is a center.
JP 2005-096002 A

In the prior art machine tool described in Patent Document 1, one of the pair of support members is a chuck and the other is a center. There is no particular problem if the same workpiece is processed all the time with this machine tool, but it is rare that only a specific workpiece is processed, and various workpieces are processed with one machine tool.
For example, the EPS ball screw has various shapes, and there is a work in which a threaded portion K is arranged near the center with respect to the longitudinal direction as in the work W shown in FIGS. 2A and 2B. There is also a work in which a threaded portion K is disposed at one end with respect to the longitudinal direction, such as a work W1 shown in (A) and (B). In the case of the workpiece W shown in FIGS. 2A and 2B, both of the pair of support members are preferably chucks. In the case of the workpiece W1 shown in FIGS. The side closer to K is preferably the center, and the side farther from the threaded portion K is preferably a chuck.
Conventionally, when the workpiece W1 shown in FIGS. 6 (A) and 6 (B) is processed after the workpiece W shown in FIGS. 2 (A) and 2 (B) is processed, it is shown in FIGS. 2 (A) and 2 (B). The chuck 40C is removed from the tailstock device 40, and the center 140C is attached to the tailstock device 40 as shown in FIGS. 6 (A) and 6 (B). In the opposite case, the center 140C is removed from the tailstock device 40 shown in FIGS. 6 (A) and 6 (B), and the chuck 40C is attached to the tailstock device 40 as shown in FIGS. 2 (A) and 2 (B). ing.
However, the replacement work from the chuck 40C to the center 140C or the replacement work from the center 140C to the chuck 40C requires not only replacement but also centering work after replacement, and therefore requires a very long time.
The present invention has been devised in view of such points, and it is an object of the present invention to provide a machine tool capable of changing a support member from a chuck to a center or from a center to a chuck in a shorter time. And

As means for solving the above problems, a first invention of the present invention is a machine tool as set forth in claim 1.
A machine tool according to claim 1 is a machine tool that supports both ends of a workpiece with a pair of support members and rotates the workpiece about a support shaft passing through the pair of support members.
At least one of the pair of support members is a chuck having an insertion hole through which a workpiece to be supported is inserted and a plurality of claw portions that hold the workpiece from the side surface of the inserted workpiece.
The center adapter further includes a center adapter configured to be detachable from the chuck, the center adapter having a substantially conical center portion at a distal end portion, and a diameter corresponding to the insertion hole behind the center portion. It has the insertion part which has.
Then, the center adapter can be attached to the chuck by inserting the insertion portion of the center adapter into the insertion hole of the chuck and holding the center adapter by the claw portion. The workpiece can be supported by the chuck when the center adapter is not attached to the chuck, and at the center portion of the center adapter when the center adapter is attached to the chuck. The workpiece can be supported.
The chuck is provided with one or a plurality of mounting holes, and the center adapter has a flange portion between the center portion and the insertion portion, and corresponds to the mounting hole in the flange portion. A hole portion having a diameter larger than that of the mounting hole at a position where the insertion portion of the center adapter is inserted into the insertion hole of the chuck and gripped by the claw portion and then centered. Furthermore, after the center adapter is fixed to the chuck using a fixing member that passes through the hole and is fixed to the mounting hole, the gripping state of the center adapter by the claw is maintained, or the claw is Leave it open.

A second invention of the present invention is a machine tool as set forth in claim 2 .
The machine tool according to claim 2 is the machine tool according to claim 1 , wherein a chuck selected from a plurality of chucks having different gripping diameter ranges is attached as the support member. .
In view of this, it has a substantially cylindrical shape, the outer diameter corresponds to each of the diameters that can be gripped by the respective chucks, and the inner peripheral surface is formed in a diameter and shape that fits into the fitting portion of the center adapter. A plurality of diameter conversion adapters are provided.
And the fitting part which makes each of several said diameter conversion adapters detachable is formed in the side surface facing the said nail | claw part in the said center adapter penetrated by the said penetration hole.

If the machine tool according to claim 1 is used, the support member can be changed from the chuck to the center in a short time by causing the chuck to grip the center adapter. Further, by removing the gripping center adapter, the support member can be changed from the center to the chuck in a short time.
In this way, instead of replacing the chuck and the center, the center adapter is attached to and detached from the chuck without removing the chuck, so that the support member can be moved from the chuck to the center or from the center to the chuck. It can be changed in a short time.
Further, since the chuck is not removed, the centering function of the chuck itself can be used when centering the attached center adapter, so that the centering can be performed in a shorter time.

According to the machine tool of the first aspect, when the center adapter is attached to the chuck, the center adapter can be more firmly fixed to the chuck in a short time.
In addition, after the center adapter is fixed to the chuck using the fixing member, the claw portion may be either in the gripped state or in the open state, and the chuck claw portion maintained in the gripped state is in an unclamped state ( Even if it is in the open state, the center adapter is not removed, so it is safe.

According to the machine tool according to claim 2, for a plurality of chucks corresponding to the grippable diameter, a plurality of diameter conversion adapters having an outer diameter corresponding to the grippable diameter of each chuck. Since it is only necessary to select an appropriate diameter conversion adapter and attach it to the fitting portion of the center adapter, it is not necessary to prepare a plurality of center adapters according to the grippable diameter of each chuck, which is convenient.

The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 (A) shows a schematic external view (plan view) in an embodiment in which a machine tool 1 of the present invention is applied to a machine tool 1 (so-called grinder) equipped with a grindstone T. FIG. 1B shows an example of a right side view of the machine tool 1 shown in FIG. In FIG. 1B, illustration of the tailstock device 40 and the like is omitted.
In the description of the present embodiment, the X axis, the Y axis, and the Z axis are orthogonal to each other, the Y axis indicates a vertically upward direction, and the X axis and the Z axis indicate a horizontal direction. Further, the X axis indicates the direction in which the grindstone T cuts into the workpiece W, and the Z axis indicates the direction of the main shaft rotation axis passing through a pair of support members (in the example of FIG. 1, chuck 30C and chuck 40C).

● [Schematic configuration of machine tool 1 (FIGS. 1A and 1B)]
The machine tool 1 includes a base 2, a spindle table 20, and a grindstone table 10. Note that control means such as a numerical controller that takes in signals from the detection means and outputs drive signals to the motors are omitted.
1A, 1B, 2A, and 2B show an example in which the screw portion K is disposed near the center of the workpiece W, and a pair of support members 30C. , 40C shows an example in the case of a chuck.
The spindle table 20 is Z with respect to the base 2 by a spindle table driving motor 20M (Z-axis driving device) and a feed screw 20B provided on the base 2 and a nut (not shown) provided on the spindle table 20. It can move in the axial direction, and the control means can detect the position of the spindle table 20 in the Z-axis direction with respect to the base 2 based on the detection signal of the detection means 20E such as an encoder. The Z axis is an axis parallel to a main shaft rotation axis CZ (corresponding to a support axis) passing through a pair of support members (in the example of FIG. 1, chuck 30C and chuck 40C), and the feed screw 20B is the Z axis. .

On the spindle table 20, a spindle stock 30D and a tailstock 40D are placed.
The spindle stock 30D is provided with a spindle moving motor 30M that can reciprocate the spindle device 30 in the Z-axis direction, and the control means uses the detection signal of the detecting means 30E such as an encoder to control the spindle device 30 relative to the spindle stock 30D. Can be detected in the Z-axis direction. A chuck 30 </ b> C that is paired with the chuck 40 </ b> C of the tailstock device 40 is provided at the tip of the spindle device 30. Further, the spindle device 30 is provided with a spindle rotating motor that rotates the chuck 30C, and rotates the workpiece W supported by a pair of support members (in this case, chucks 30C and 40C) around the spindle rotating axis CZ. . The spindle rotation motor is provided with detection means (such as an encoder) for detecting the rotation angle or rotation speed of the workpiece W.
The tailstock 40D is provided with a tailstock movement motor 40M that can reciprocate the tailstock device 40 in the Z-axis direction, and the control means is based on the detection signal of the detection means 40E such as an encoder. The position of the tailstock device 40 with respect to the Z-axis direction can be detected. Further, a chuck 40 </ b> C that is paired with the chuck 30 </ b> C of the spindle device 30 is provided at the tip of the tailstock device 40.
In addition, the machine tool 1 is provided with a temporary placement table 60 for temporarily placing the workpiece W before the workpiece W is supported by the pair of support members.
In addition, although the machine tool 1 is provided with the coolant nozzle etc. which eject a coolant to a process location, description and illustration are abbreviate | omitted about these.

The grindstone table 10 includes a substantially cylindrical grindstone T (corresponding to a processing tool). The grindstone T is shaped, for example, by attaching a CBN chip grindstone to the outer periphery of an iron core. The grindstone driving motor 11 placed on the grindstone table 10 is used to center a grindstone rotation axis TZ parallel to the Z axis. Rotate.
The grindstone table 10 includes a grindstone table drive motor 10M (X-axis drive device, cutting means) and a feed screw 10B provided on the base 2, and a nut (not shown) provided on the grindstone table 10. The grindstone T can be reciprocated in the X-axis direction with respect to the base 2, and the grindstone T is moved back and forth in a direction crossing the spindle rotation axis CZ. The X axis is an axis in a direction orthogonal to the Z axis, and the feed screw 10B is the X axis.
The grinding wheel table drive motor 10M is provided with detection means 10E (such as an encoder) for detecting the position of the grinding wheel table 10 in the X-axis direction.
In the example of FIGS. 1A and 1B, the grindstone drive motor 11 is not provided with detection means, but the grindstone drive motor 11 is also provided with speed detection means and the like, and the rotation speed of the grindstone drive motor 11 is increased. It is also possible to perform feedback control.

  The numerical control device (not shown) includes a signal from a detection means (not shown) for detecting the rotation angle (or rotation speed) of the workpiece W and a detection means 10E for detecting the position of the grindstone table 10 in the X-axis direction. , A signal from the detection means 20E for detecting the position of the spindle table 20 in the Z-axis direction, machining data, a machining program, and the like, a spindle rotating motor (not shown), a grindstone table driving motor 10M, a spindle table The drive motor 20M and the grindstone drive motor 11 are controlled.

● [Operation for workpiece W suitable for supporting both ends with a chuck (FIGS. 2A and 2B)]
2A and 2B are views for explaining a state in which both ends of the workpiece W having the threaded portion K formed in the vicinity of the center in the longitudinal direction are supported. In this case, the pair of supporting members is the chuck 30C. And chuck 40C. The spindle device 30 can reciprocate in the Z-axis direction via a connecting member 31 that reciprocates in the Z-axis direction by a feed screw 30B rotated by a spindle movement motor 30M. The feed screw 40B rotated by the motor 40M can reciprocate in the Z-axis direction via a connecting member 41 that reciprocates in the Z-axis direction.

First, as shown in FIG. 2 (A), the position of the spindle device 30 with respect to the spindle stock 30D so that the distance between the spindle device 30 and the tailstock device 40 is sufficient so as not to interfere with the workpiece W, and The position of the tailstock device 40 with respect to the tailstock 40D is determined, and the workpiece W is temporarily placed on the temporary placement table 60. At this time, the claw portions 35 and 45 of the chucks 30C and 40C are in an open state (unclamped state).
Then, as shown in FIG. 2B, the spindle device 30 and the tailstock device 40 are moved in directions close to each other, and both ends of the workpiece W are inserted into the chuck 30C and the chuck 40C, and the chuck 30C. The inserted workpiece W is held by the claw portion 35 and the claw portion 45 of the chuck 40C.

Conventionally, as shown in FIGS. 6 (A) and 6 (B), when the work is a work W1 in which a thread portion is arranged at one end in the longitudinal direction of the work, FIGS. 2 (A) and 2 (B). After the chuck 40C of the tailstock device 40 shown in FIG. 6 is removed and the center 140C shown in FIGS. 6A and 6B is attached, the workpiece W1 is supported by performing the same operation as described above (the workpiece W1 is temporarily attached). It is mounted on the mounting table 60, and the spindle device 30 and the tailstock device 40 are brought close to each other and supported).
However, the replacement work for removing the chuck 40C and attaching the center 140C (or the replacement work for removing the center 140C and attaching the chuck 40C) takes a lot of time and effort, and further, it takes time to center the chuck or center after replacement. Conventionally, if the chuck and the center are exchanged, the working efficiency is very low.
Therefore, in the embodiment of the present application, as will be described below, the chuck is removed from the main spindle device 30 or the tailstock device 40, and a center adapter that can be attached to and detached from the chuck is attached to or removed from the chuck to the center. In addition, the structure can be easily changed from the center to the chuck in a short time.

[First embodiment of the structure of the center adapter 70 and the structure of the chuck to which the center adapter 70 can be attached and detached (FIG. 3)]
Next, the first embodiment of the structure of the center adapter 70 and the structure of the chuck to which the center adapter 70 can be attached and detached will be described with reference to FIGS. 3A to 3D illustrate an example in which the center adapter 70 is attached to and detached from the chuck 40C of the tailstock device 40, the chuck 30C of the spindle device 30 can have the same structure. . The tailstock device 40 shown in FIGS. 3A and 3B has a schematic shape.
3C shows the chuck 30C viewed from the AA direction in FIG. 3A, and FIG. 3D shows the center adapter 70 viewed from the AA direction in FIG. 3A. .

The chuck 40C is attached to the tip of a spindle 40S that rotates about the main shaft rotation axis CZ.
As shown in FIGS. 3A and 3C, the chuck 40 </ b> C includes an insertion hole 43 through which an end portion of the workpiece W to be supported and a plurality of claw portions 45 that grip the workpiece W from the side surface of the inserted workpiece W. And a pedestal portion 42 that comes into contact with the flange portion 73 of the center adapter 70. The pedestal portion 42 is provided with a mounting hole 44 for fixing the center adapter 70 with a fixing member such as a bolt. Note that the pedestal portion 42 protrudes in the direction of the flange portion 73 rather than the claw portion 45.
As shown in FIGS. 3A and 3D, the center adapter 70 has a substantially conical center portion 71 at the tip, and an insertion having a diameter corresponding to the insertion hole 43 behind the center portion 71. A portion 72 is provided. Further, a flange portion 73 is provided between the center portion 71 and the insertion portion 72, and a hole portion 74 having a slightly larger diameter than the attachment hole 44 is provided at a position corresponding to the attachment hole 44 in the flange portion 73. Is provided.
The mounting hole 44 and the hole 74 may be single or plural.

When attaching the center adapter 70 to the chuck 40C, first, the claw portion 45 of the chuck 40C is opened (unclamped) in FIG.
Then, the insertion portion 72 of the center adapter 70 is inserted into the insertion hole 43 of the chuck 40C, the flange portion 73 and the pedestal portion 42 are brought into contact with each other, and the positions of the mounting hole 44 and the hole portion 74 (viewed from the Z-axis direction). The position of the center adapter 70 is adjusted so that the position) matches, and the center adapter 70 is clamped (gripped) by the claw portion 45. Then, after centering the center adapter 70 using the centering function of the chuck itself, the center adapter 70 is chucked using a fixing member (bolt or the like) that passes through the hole 74 and is fixed to the mounting hole 44. Firmly fix (fasten) to 40C. By forming the diameter of the hole 74 larger than that of the direct member of the fixing member (bolt or the like), the fixing member (bolt or the like) is maintained while keeping the center adapter 70 centered by the clamp of the claw portion 45. It can be fixed with. After the center adapter 70 is fixed to the chuck 40C using the fixing member, the claw portion 45 may be in either the gripped state or the open state.
Since the air pressure and hydraulic pressure for clamping the center adapter 70 are cut off, the claw portion 45 of the chuck 40C maintained in the gripped state is in an unclamped state (opened state). Even if it does, the center adapter 70 will not be removed, so it is safe.
Further, when removing the center adapter 70 attached to the chuck 40C, after removing the fixing member such as a bolt and then holding the claw part 45, the claw part 45 is opened and the center adapter 70 is removed. If the claw portion 45 is in an open state, the center adapter 70 may be extracted as it is.
Note that the pedestal portion 42 of the chuck 40C and the flange portion 73 of the center adapter 70 may be omitted, and the fixing with the fixing member may be omitted (the fixing may be performed only by gripping the claw portion 45).

[Second embodiment of the structure of the center adapter 70 and the structure of the chuck to which the center adapter 70 can be attached and detached (FIG. 4)]
Next, a second embodiment of the structure of the center adapter 70 and the structure of the chuck to which the center adapter 70 can be attached and detached will be described with reference to FIGS. 4A to 4C illustrate an example in which the center adapter 70 is attached to and detached from the chuck 40C of the tailstock device 40, the chuck 30C of the spindle device 30 can have the same structure. . Moreover, the tailstock apparatus 40 shown to FIG. 4 (A)-(C) has shown schematic shape (sectional drawing).

The chuck 40C is attached to the tip of a spindle 40S that rotates about the main shaft rotation axis CZ. The insertion hole 43 is formed from the chuck 40 </ b> C into the spindle 40 </ b> S and has a tapered shape whose diameter gradually decreases toward the back.
Further, the center adapter 70 has a substantially conical center portion 71 at the tip, and has an insertion portion 72 having a length corresponding to the insertion hole 43 behind the center portion 71, and the insertion portion 72 is an insertion hole. It is formed in a shape along the 43 taper shape.
In contrast to the first embodiment shown in FIG. 3, in the second embodiment shown in FIG. 4, the base portion 42 of the chuck 40 </ b> C is unnecessary, and the flange portion 73 of the center adapter 70 is unnecessary.

When attaching the center adapter 70 to the chuck 40C, first, in FIG. 4A, the claw portion 45 of the chuck 40C is brought into an open state (clamp release state).
Then, the insertion portion 72 of the center adapter 70 is inserted into the insertion hole 43 of the chuck 40C (see FIG. 4B). Then, as shown in FIG. 4C, the center adapter 70 is clamped (gripped) by the claw portion 45. Then, the center adapter 70 is centered using the centering function of the chuck itself. In the second embodiment, centering is easier than in the first embodiment with the insertion hole 43 and the insertion portion 72 formed in a tapered shape.
When removing the center adapter 70 attached to the chuck 40C, the claw portion 45 may be opened and the center adapter 70 may be removed.

[Third embodiment of the structure of the center adapter 70 and the structure of the chuck to which the center adapter 70 can be attached and detached (FIG. 5)]
Next, the third embodiment of the structure of the center adapter 70 and the structure of the chuck to which the center adapter 70 can be attached and detached will be described with reference to FIGS. In the third embodiment, the diameter of the side surface of the center adapter 70 facing the claw portion 45 of the chuck 40C is changed from that of the second embodiment shown in FIG. The difference is that it can be changed freely. Hereinafter, this difference will be described. In addition, the tailstock apparatus 40 shown to FIG. 5 (A)-(C) has shown schematic shape (sectional drawing).
Note that a normal chuck cannot be properly gripped unless the member has a diameter within a preset range in terms of the diameter of the insertion hole 43 and the movable range of the claw portion 45. Therefore, a chuck selected from a plurality of chucks having different gripping diameter ranges according to the diameter of the workpiece W is attached to the tip of the spindle 40S.
However, it is not preferable to prepare the center adapter 70 having various diameters according to the diameter within a range that can be gripped by the chuck because it takes time and requires a large storage space. Therefore, the diameter of the center adapter 70 can be easily changed by using the substantially cylindrical diameter conversion adapter 75.

As shown in FIG. 5A, on the side surface of the center adapter 70 inserted through the insertion hole 43 that faces the claw portion 45 of the chuck 40C, fitting portions 76 ( For example, a screw groove) is formed.
Each diameter conversion adapter 75 has an outer diameter D corresponding to the chuck, and the inner peripheral surface is formed in a diameter and shape that fits into the fitting portion 76 of the center adapter 70 (for example, a thread groove is provided). Formed).

When attaching the center adapter 70 to the chuck 40C, first, the claw portion 45 of the chuck 40C is opened (unclamped) in FIG.
Then, the diameter conversion adapter 75 having an outer diameter corresponding to the chuck 40C is selected, the selected diameter conversion adapter 75 is fitted into the fitting portion 76 of the center adapter 70, and the insertion portion 72 of the center adapter 70 is connected to the chuck 40C. It passes through the insertion hole 43 (see FIG. 5B).
Then, as shown in FIG. 5C, the center adapter 70 is clamped (gripped) by the claw portion 45. Then, the center adapter 70 is centered using the centering function of the chuck itself.
When removing the center adapter 70 attached to the chuck 40C, the claw portion 45 may be opened and the center adapter 70 may be removed.
Further, the center adapter 70 described in the first and second embodiments also forms a fitting portion 76 in the same manner as the third embodiment, and a diameter conversion adapter 75 having an outer diameter corresponding to the chuck 40C is provided. It is also possible to configure so that it can be selected and fitted.

As described above, in the machine tool described in the present embodiment, the support member can be easily and shortly attached from the chuck to the center and from the center to the chuck by detaching the center adapter from the chuck without removing the chuck. Can change on time. In addition, since the chuck is not removed, when the center adapter is attached, the center adapter can be centered using the centering function of the chuck itself. It can be carried out.
As a result, the changeover between the chuck and the center is facilitated, the changeover time can be greatly shortened, and the productivity can be improved.
In addition, since the center is directly attached to the chuck, the length of the center portion can be made shorter than before, rigidity can be ensured, and good processing accuracy can be obtained.

The machine tool 1 of the present invention is not limited to the appearance, configuration, structure, and the like described in the present embodiment, and various modifications, additions, and deletions can be made without changing the gist of the present invention.
In the present embodiment, the grindstone T is used as an example of the processing tool. However, the present invention can be applied to a machine tool using various processing tools such as a cutting tool and an end mill.
In this embodiment, an example in which the center adapter 70 can be attached to and detached from the chucks 30C and 40C has been described. However, at least one of the chucks 30C and 40C may have a structure in which the center adapter 70 can be attached and detached.

It is a figure explaining the schematic external view (plan view, side view) in one embodiment of machine tool 1 of the present invention. It is a figure explaining the operation | movement which hold | grips the workpiece | work W in case a pair of supporting member is the chuck | zipper 30C and the chuck | zipper 40C. It is a figure explaining the center adapter 70 and the chuck | zipper 40C which can attach or detach the said center adapter 70 in 1st Embodiment. It is a figure explaining the center adapter 70 and the chuck | zipper 40C which can attach or detach the said center adapter 70 in 2nd Embodiment. It is a figure explaining the center adapter 70 and the chuck | zipper 40C which can attach or detach the said center adapter 70 in 3rd Embodiment. It is a figure explaining the example of the conventional structure where one of a pair of supporting members is chuck 30C, and the other is center 140C.

DESCRIPTION OF SYMBOLS 1 Machine tool 2 Base 10 Grinding wheel table 10M Grinding wheel table drive motor 10B Feed screw 11 Grinding wheel drive motor 20 Spindle table 20M Spindle table drive motor 20B Feed screw 30 Spindle device 30C Chuck (support member)
30D Spindle base 30M Spindle movement motor 35 Claw portion 40 Tailstock device 40C Chuck (support member)
40D Tailstock 40M Tailstock Motor 40S Spindle 42 Base 43 Insertion Hole 44 Mounting Hole 45 Claw 70 Center Adapter 71 Center Part 72 Insertion Part 73 Flange Part 74 Hole Part 75 Diameter Conversion Adapter 76 Fitting Part T Grinding Stone (Processing) tool)
W Work CZ Spindle rotation axis (support axis)
TZ grinding wheel rotation axis

Claims (2)

A machine tool that supports both ends of a workpiece with a pair of support members and rotates the workpiece about a support axis passing through the pair of support members,
At least one of the pair of support members is a chuck having an insertion hole for inserting a workpiece to be supported and a plurality of claw portions for holding the workpiece from a side surface of the inserted workpiece.
Furthermore, a center adapter configured to be detachable from the chuck is provided,
The center adapter has a substantially conical center portion at a tip portion, and has an insertion portion having a diameter corresponding to the insertion hole behind the center portion,
The center adapter is configured to be attached to the chuck by inserting the insertion portion of the center adapter through the insertion hole of the chuck, gripping the center adapter by the claw portion, and centering the center adapter. And
The workpiece can be supported by the chuck when the center adapter is not attached to the chuck, and the workpiece is supported by the center portion of the center adapter when the center adapter is attached to the chuck. Is possible ,
The chuck is provided with one or a plurality of mounting holes,
The center adapter has a flange portion between the center portion and the insertion portion, and has a hole portion having a diameter larger than the attachment hole at a position corresponding to the attachment hole in the flange portion,
After the insertion portion of the center adapter is inserted into the insertion hole of the chuck and gripped by the claw portion and centered, a fixing member that penetrates the hole portion and is fixed to the mounting hole is further provided. After fixing the center adapter to the chuck using, the gripping state of the center adapter by the claw part is maintained, or the claw part is opened.
Machine Tools. The machine tool according to claim 1 ,
As the support member, a chuck selected from a plurality of chucks having different gripping diameter ranges is attached,
It has a substantially cylindrical shape, the outer diameter corresponds to each of the diameters that can be gripped by each chuck, and the inner peripheral surface has a plurality of diameters and shapes that fit into the fitting portion of the center adapter. Equipped with a diameter conversion adapter
On the side surface facing the claw portion in the center adapter inserted through the insertion hole, the fitting portion that allows each of the plurality of diameter conversion adapters to be attached and detached is formed.
Machine Tools.

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