JP2013166233A - Tool holder and machining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool holder and a machining method by which a stroke can be lengthened for a general machine tool only when necessary.SOLUTION: A tool holder 20 is mounted to a main spindle 17 supported on a main spindle head 15 and supports a cutting tool 18 for machining. The tool holder includes a shaft 22 connected to the main spindle 17, a case 21 rotatably supporting the shaft 22 and connected to the main spindle head 15, an arm 23 supported so as to be advanced and retracted to/from the case 21 and supporting the cutting tool 18, and a driving mechanism 24 advancing and retracting the arm 23 by the rotation of the shaft 22 with respect to the case 21.

Description

  The present invention relates to a tool holder and a turning method for holding a turning tool, and more particularly to a tool holder and a turning method for holding a tool that is mounted on a spindle for rotary cutting and performs turning.

Various types of machine tools have been used in the past, but some machine tools can be equipped with a rotating tool on the spindle to drill or mill the workpiece, while rotating the table to which the workpiece is fixed. Some tools can be used as a vertical lathe by turning with a tool mounted on the spindle.
As such a machine tool, there is a turning center having a table on which a work is placed on a flat upper surface and rotatable around a vertical axis, and a main shaft arranged in a vertical direction above the table (Patent Document 1). reference).

  A vertical turning center 90 shown in FIG. 12 has a rotatable table 92 on the upper surface of a base 91. The table 92 is driven by a motor or the like built in the base 91, can be rotated at an arbitrary speed, and can be stopped at an arbitrary rotation angle. A column 93 is installed on the base 91 adjacent to the table 92, and a boom 94 extending upward from the table 92 is supported on the column 93. A spindle head 95 is installed on the boom 94, and a ram 96 that can advance and retract toward the table 92 is attached to the spindle head 95. A main shaft 97 is supported on the ram 96, and the main shaft 97 is driven by a motor or the like built in the ram 96 and can be rotated at an arbitrary speed and can be stopped at an arbitrary rotation angle.

In such a turning center 90, a drill is attached to the tip of the main shaft 97, the main shaft 97 is rotated, and the drill is brought close to the work 99 on the table 92, so that the vertical direction (Z-axis direction) with respect to the work 99. ) Can be perforated.
Further, a cutting tool 98 is attached to the tip of the main shaft 97, the cutting tool 98 is held toward the central axis of the table 92, the table 92 to which the work 99 is fixed is rotated, and the cutting tool 98 is brought close to the side surface of the work. Thus, the workpiece 99 can be turned.
At this time, the cutting tool 98 attached to the tip of the main shaft 97 is moved from the top surface of the table 92 (Z with respect to the workpiece 99) by the Z-axis movement of the boom 94 with respect to the column 93 and the Z-axis movement of the ram 96 with respect to the main shaft head 95. Axis position) is set. Further, the tool 98 is set to have a distance from the rotation axis of the table 92 (the outer diameter of the work 99) by the Y-axis movement of the spindle head 95 relative to the boom 94.

By the way, the tool such as a tool 98 attached to the tip of the main shaft 97 has a height from the upper surface of the table 92 such that the Z axis movement of the boom 94 with respect to the column 93 and the Z of the ram 96 with respect to the main shaft head 95 as described above. It is defined by the axis movement.
In FIG. 12, with respect to the entire stroke ST in the Z-axis direction at the tip of the spindle 97, the stroke SC is due to the Z-axis movement of the boom 94 relative to the column 93, and the stroke SR is due to the Z-axis movement of the ram 96 relative to the spindle head 95. The maximum value of all strokes ST is given by the sum of stroke SC and stroke SR. The total stroke ST thus obtained is the maximum machining range in the Z-axis direction for the workpiece 99.

JP-A-8-206936

By the way, as the turning of the workpiece 99 using the turning center 90 described above, in addition to machining of the outer peripheral surface (outer turning), machining of the inner peripheral surface of the concave portion from the upper surface of the work 99 (inner turning) ) Even in the case of outer turning, outer peripheral turning near the lower end of the workpiece 99 having a large height may be performed.
In such a case, the conventional turning center 90 may not be able to cope with it sufficiently.

As described above, the cutting tool 98 attached to the tip of the main shaft 97 has a maximum machining range in the Z-axis direction of the entire stroke ST, and the value does not exceed the sum of the stroke SC and the stroke SR.
Here, for example, when the hole SR is deeper than the stroke SR from the upper surface of the workpiece 99 while the stroke SR is due to the Z-axis movement of the ram 96 with respect to the spindle head 95, the ram 96 with respect to the spindle head 95 is processed. The Z-axis movement alone is not sufficient, and the Z-axis movement of the boom 94 relative to the column 93 must be used.
However, when the boom 94 is moved downward in the Z-axis direction, the boom 94 near the cutting tool 98 or a part of the spindle head 95 may interfere with the upper end of the workpiece 99.

As a method for avoiding such a problem, it is conceivable to sufficiently increase the stroke SR of the ram 96.
However, in the general turning center 90, the stroke SR of the ram 96 is shorter than the stroke SC of the column 93, and a large-scale modification is required in order to increase the length. Such a large-scale remodeling requires a considerable amount of refurbishment and a large amount of cost. On the other hand, the turning center 90 in which the stroke SR of the ram 96 is longer than the stroke SC of the column 93 is special and generally difficult to use.
Therefore, in a general turning center 90 in which the stroke SR of the ram 96 is shorter than the stroke SC of the column 93, a device capable of making the stroke SR longer only when necessary has been desired.

  An object of the present invention is to provide a tool holder and a turning method capable of extending a stroke only when necessary for a general machine tool.

  The present invention is a bite holder that is mounted on a general turning center and holds a bite, and the above-mentioned object is obtained by expanding and contracting a part that supports the bite by using rotation of a main shaft that can be used in the turning center. Is achieved.

  A tool holder according to the present invention is a tool holder that is mounted on a spindle supported by a spindle head and supports a turning tool, and a shaft connected to the spindle, a shaft that rotatably supports the shaft, and the It has a case connected to the spindle head, an arm supported so as to be able to advance and retract from the case and supporting the bite, and a drive mechanism for moving the arm forward and backward by rotation of the shaft relative to the case.

The shaft of the present invention desirably has a tapered shank that can be fixed by a collet chuck formed on the main shaft. The shaft is preferably supported by the case via a bearing such as a ball bearing so that the shaft can rotate freely.
In the case of the present invention, in order to obtain connection with the spindle head, it is desirable to provide an auxiliary shank or the like extending to the side of the spindle. Further, the case is not limited to the case directly connected to the spindle head, and may be connected to the ram that supports the spindle and indirectly connected to the spindle head via this ram. It only has to be prevented from rotating.

In the present invention, by attaching the tool holder to the spindle, the tool is held on the spindle of the machine tool, and turning can be performed.
Here, the position of the cutting tool in the machine tool is set by adjusting the position of the spindle head (or the ram that advances and retracts from the spindle head). Furthermore, in the present invention, the position of the cutting tool with respect to the main shaft (and the ram) can be adjusted by rotating the main shaft.
That is, when the main shaft is rotated, this rotation is transmitted to the shaft, and the arm is advanced and retracted by the drive mechanism. As a result, the position of the cutting tool supported by the arm can be changed.
Therefore, according to the present invention, a tool holder is attached to the tool stroke by the spindle head or the spindle (including the ram) (the column stroke or the ram stroke described above) as necessary, so that only the arm stroke is provided. The byte alignment range can be expanded.
The extension of the tool stroke can be achieved by simply attaching the tool holder according to the present invention to an existing machine tool when necessary, and without greatly modifying the existing machine tool. It becomes possible.

In the present invention, it is desirable that the arm and the shaft are disposed on an axis of the main shaft, and the arm is movable forward and backward in the axial direction of the main shaft.
In the present invention, the shaft and the arm are arranged on one axis from the main shaft, and the moving range of the cutting tool can be expanded along the main shaft axis. For example, if applied to the above-mentioned conventional turning center (see FIG. 12), the range of movement of the cutting tool can be expanded by moving the arm in addition to the movement of the ram, making it ideal for lengthening the stroke as required. It is.

In the present invention, the drive mechanism includes a male screw portion formed on the shaft, a female screw portion formed on the arm and screwed into the male screw portion, and a rotation prevention mechanism that prevents the arm from rotating with respect to the case. It is desirable to have
In the present invention, the anti-rotation mechanism includes a structure in which a key groove in the arm advancing / retreating direction is formed in one of the arm and the case, and a key member or protrusion that engages with the groove is formed in the other, or the arm and the case. A structure in which protrusions in the advancing and retreating direction of the arm, a case in which the case and the arm have a rectangular cross section, and the like can be used as appropriate.
In the present invention, the arm is prevented from rotating with respect to the case by the rotation preventing mechanism, and when the shaft rotates, the arm is driven in the axial direction via the male screw portion and the female screw portion that are screwed together. Therefore, in the configuration in which the shaft and the arm are arranged on one axis from the main shaft described above, a reliable operation can be performed while the drive mechanism is simple.

In the present invention, it is preferable that the shaft is disposed on an axis of the main shaft, and the arm is movable forward and backward in a direction intersecting with the axis of the main shaft.
In the present invention, the arm advances and retreats in the intersecting direction, that is, the radial direction of the main shaft with respect to the main shaft and the shaft axis (in the case where the cross direction is inclined with respect to the main shaft axis). This makes it possible to adjust the position of the cutting tool in the radial direction from the axis of the main shaft.
In the present invention, when the above-described internal turning of the workpiece is performed, it is possible to perform the machining such that the inner diameter of the workpiece is larger than the opening diameter, which has been difficult in the past. That is, when the arm is contracted and introduced into the concave portion of the work from the opening of the work, and the arm is advanced to perform internal turning, turning with an inner diameter larger than the opening diameter can be performed.

In the present invention, as the drive mechanism, a pair of bevel gears that convert the rotation of the shaft into the cross direction is used, and the auxiliary shaft extending in the cross direction is rotated by the gear, and the male screw portion of the auxiliary shaft and the female screw portion of the arm Can be used.
Alternatively, as the drive mechanism, a male screw part formed on the shaft, an intermediate member having a female screw part screwed into the male screw part, and a displacement of the intermediate member in the axial direction of the main shaft is used to move the arm forward and backward. A configuration having a direction changing mechanism for conversion can be employed.
As the direction changing mechanism, it is possible to use a configuration in which the intermediate member is a tapered cone, the arm is brought into contact with the tapered surface of the intermediate member, and the arm is advanced and retracted by utilizing the change in the outer diameter of the contact portion of the cone. .

In the present invention, it is desirable that the pair of cutting tools are mounted in opposite directions.
In the present invention as described above, a pair of cutting tools mounted in opposite directions is used to introduce a cutting tool holder into the inside of the workpiece, and the inner peripheral surface of the workpiece is machined with one cutting tool, and then the cutting tool holder is moved to the outside of the workpiece. The outer peripheral surface of the workpiece can be machined with the other tool.
Here, when there is only one tool, it is necessary to reverse the entire tool holder by 180 degrees, or to increase the movement in order to shift the processing position with respect to the work (angle position with respect to the work center axis) by 180 degrees, The complexity of structure or operation is inevitable.
However, in the present invention, since a pair of cutting tools are provided on the opposite sides, it is possible to perform machining with the shortest distance from the inside to the outside (or from the outside to the inside) at the same angular position of the workpiece.

The turning method of the present invention is a turning method for turning a workpiece using a machine tool having a ram supported by a spindle head so as to be able to advance and retract, and a spindle supported by the ram. It is attached to the main shaft, and the advance of the arm in the tool holder and the advance of the ram in the machine tool are synchronized.
In the present invention, synchronizing the advancement of the arm and the advancement of the ram means that the ram is also at one end of the stroke when the arm is at one end of the stroke, and the ram reaches the other end when the arm is at the other end. This is the behavior. Specifically, based on the stroke of the arm and the stroke of the ram, the respective moving speeds may be set based on the ratio of the strokes and controlled to move in the same direction at the same time.

According to the present invention as described above, since the arm and the ram move uniformly over the entire stroke, it is possible to eliminate the cutting traces associated with the operation switching formed on the workpiece.
For example, when switching to move the arm after moving only the ram for its entire stroke, turning traces remain on the workpiece at the time of switching. However, by controlling as in the present invention, switching does not occur over the entire stroke that is the sum of the stroke of the ram and the stroke of the arm.

The side view which shows the whole apparatus of 1st Embodiment of this invention. Sectional drawing which shows the principal part of the said 1st Embodiment. The perspective view which shows 2nd Embodiment of this invention. The perspective view which shows the state which extended the arm of the said 2nd Embodiment. The perspective view which shows 3rd Embodiment of this invention. The perspective view which shows the state which extended the arm of the said 3rd Embodiment. The perspective view which shows 4th Embodiment of this invention. The perspective view which shows the state which extended the arm of the said 4th Embodiment. The perspective view which shows 5th Embodiment of this invention. The perspective view which shows the state which extended the arm of the said 5th Embodiment. Sectional drawing which shows 6th Embodiment of this invention. The side view which shows the conventional apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
In FIG. 1, a turning center 10 that is a machine tool has a rotatable table 12 on an upper surface of a base 11. The table 12 is driven by a motor or the like built in the base 11 and can be rotated at an arbitrary speed, and can be stopped at an arbitrary rotation angle. A column 13 is installed on the base 11 adjacent to the table 12, and a boom 14 extending upward from the table 12 is supported on the column 13. A head 15 is installed on the boom 14, and a ram 16 that can be advanced and retracted toward the table 12 is attached to the head 15. A main shaft 17 is supported on the ram 16, and the main shaft 17 is driven by a motor or the like built in the ram 16 and can be rotated at an arbitrary speed and can be stopped at an arbitrary rotation angle.

In such a turning center 10, a drill is attached to the tip end of the main shaft 17, the main shaft 17 is rotated, and this drill is brought close to the work 19 on the table 12, thereby drilling the work 19 in the vertical direction. It is possible.
Further, a cutting tool 18 is attached to the tip of the main shaft 17, this cutting tool 18 is held toward the central axis of the table 12, the table 12 to which the work 19 is fixed is rotated, and the cutting tool 18 is brought close to the side surface of the work. Thus, the workpiece 19 can be turned.
Here, in this embodiment, the cutting tool 18 is attached to the tip end of the main shaft 17 using the cutting tool holder 20 according to the present invention.

In FIG. 2, the tool holder 20 includes a cylindrical case 21, and includes a shaft 22 and an arm 23 that are coaxially disposed in the case 21.
The case 21 has a flange 211 on the side connected to the main shaft 17, and the flange 211 includes an auxiliary shank 212 that can be connected to the ram 16, and the auxiliary shank 212 and the ram 16 rotate around the main shaft head 15. It has been stopped.

The shaft 22 is supported by the case 21 via a ball bearing 221 so as to be rotatable and restricted in the axial direction, and a tapered shank 222 is formed at a portion protruding from the end of the main shaft 17 side of the case 21. The tapered shank 222 is sandwiched between the collet chucks 171 of the main shaft 17 so that the shaft 22 is connected to the main shaft 17 and can rotate integrally when the main shaft 17 rotates with respect to the ram 16.
A male screw portion 241 is formed on the outer periphery of the shaft 22 opposite to the tapered shank 222.

The arm 23 includes an inner cylinder 231 and an outer cylinder 232 that are integrated with each other by an interference fit or the like, and a support member 233 that supports the cutting tool 18 at the tip of the outer cylinder 232 (the side opposite to the main shaft 17). .
A female screw part 242 is formed on the inner peripheral surface of the inner cylinder 231, and the male screw part 241 of the shaft 22 described above is screwed together.
A key groove 243 is formed on the outer peripheral surface of the outer cylinder 232 along the center axis direction. The key member 244 fitted into the inner surface of the case 21 is engaged with the key groove 243, thereby forming a rotation preventing mechanism, and the outer cylinder 232 is prevented from rotating with respect to the case 21.

In the present embodiment, the male screw portion 241 of the shaft 22, the female screw portion 242 of the arm 23, and a rotation prevention mechanism between the shaft 22 and the arm 23 (the key groove 243 of the arm 23 and the key member 244 fitted in the case 21). ) Constitutes the drive mechanism 24.
In the drive mechanism 24, the arm 23 is prevented from rotating around the case 21 by the key groove 243 and the key member 244, and the male screw portion 241 and the female screw portion 242 are screwed together. The rotation is converted into an advance / retreat movement of the arm 23.

In this embodiment, by attaching the tool holder 20 to the main shaft 17, the tool 18 is held on the main shaft 17 of the turning center 10, and the workpiece 19 can be turned.
Here, the position of the cutting tool 18 in the turning center 10 is set by adjusting the positions of the spindle head 15 and the ram 16, and by rotating the spindle 17, the arm 23 of the cutting tool holder 20 can be advanced and retracted. The position of 18 can be adjusted.

In the tool holder 20, when the main shaft 17 is rotated, this rotation is transmitted to the shaft 22, and the arm 23 is advanced and retracted by the drive mechanism 24. As a result, the position of the cutting tool 18 supported by the arm 23 can be changed.
Therefore, in the present embodiment, the main shaft head 15 is not moved, for example, while the main shaft head 15 is maintained at the upper end position of the stroke SC in the column 14, the stroke SR by the ram 16 and the stroke SH by the bite holder 20 are sufficient. A total stroke SS can be obtained.

The total stroke SS has a size corresponding to the above-described conventional full stroke ST. If the stroke SR of the arm 23 is increased by the design of the tool holder 20, the total stroke SS can be set to a value exceeding the full stroke ST.
The extension of the stroke of the cutting tool 18 can be achieved by simply attaching the cutting tool holder 20 according to the present invention to the existing turning center 10 when necessary, and without greatly modifying the existing turning center 10. Functions can be expanded.

In the present embodiment, as described above, the total stroke SS can be obtained without moving the spindle head 15.
The total stroke SS is the sum of the stroke SR due to the movement of the ram 16 and the stroke SH due to the movement of the arm 23 in the bite holder 20. In this embodiment, the movement of the ram 16 and the movement of the arm 23 are performed in stages. The movement of the ram 16 and the movement of the arm 23 are not synchronized.

That is, in this embodiment, in order to synchronize the advance of the arm 23 and the advance of the ram 16, for example, when the arm 23 is at the upper end of the stroke SH, the ram 16 is also set as the upper end of the stroke SR. When descending, the ram 16 is also lowered at the same time.
At this time, the moving speed VH of the arm 23 is adjusted so that VH = VR × SH / SR with respect to the moving speed VR of the ram 16. Thereby, when the arm 23 reaches the lower end of the stroke SH, the ram 16 can simultaneously reach the lower end of the stroke SR.
By performing such an operation, the arm 23 and the ram 16 move uniformly over the entire strokes SH and SR (total stroke SS). It does not occur.

[Second Embodiment]
3 and 4 show a second embodiment of the present invention.
The tool holder 20 of the present embodiment has the same configuration as that of the first embodiment described above. For this reason, below, only a different part from 1st Embodiment mentioned above is demonstrated.
In the present embodiment, the case 21 has a prismatic shape with respect to the cylindrical shape of the first embodiment. The arm 23 has a cylindrical shape as in the first embodiment, but a pair of cutting tools 18 are attached to the support member 233 at the tip thereof on opposite sides.
According to this embodiment, the same effect as that of the first embodiment described above can be obtained.

Furthermore, in this embodiment, the bit holder 20 is introduced into the inside of the workpiece by a pair of tools 18 mounted in opposite directions, and the inner peripheral surface of the workpiece is machined by one of the tools 18, and then the bit holder 20 Can be moved to the outside of the workpiece, and the outer peripheral surface of the workpiece can be machined with the other cutting tool 18.
Here, when there is only one cutting tool 18 as in the first embodiment, the support member 233 or the entire tool holder 20 is inverted 180 degrees, or the machining position with respect to the workpiece (angular position with respect to the workpiece center axis) is 180 degrees. In order to shift, it is necessary to increase the movement, and the complexity of the structure or operation is inevitable.
However, in the present embodiment, since the pair of cutting tools 18 are provided on the opposite sides, the workpiece can be processed by the shortest distance movement from the inside to the outside (or from the outside to the inside) at the same angular position of the workpiece.

[Third Embodiment]
5 and 6 show a third embodiment of the present invention.
The tool holder 20 of the present embodiment has the same configuration as that of the first embodiment described above, as well as the second embodiment described above, and has a pair of tools 18 mounted on opposite sides. However, in this embodiment, each cutting tool 18 is mounted in the vertical direction.
Also in this embodiment, the same effects as those of the first embodiment and the second embodiment described above can be obtained.
Further, in the present embodiment, the mounting direction of the pair of cutting tools 18 is different, and the cutting edge is directed to the lower surface side (the direction in which the arm 23 extends) of the cutting tool holder 20, so that the machining that requires such cutting edges is performed smoothly. be able to.

[Fourth Embodiment]
7 and 8 show a fourth embodiment of the present invention.
The tool holder 20 of the present embodiment has the same configuration as that of the first embodiment described above, as well as the second embodiment described above, and has a pair of tools 18 mounted on opposite sides. However, in this embodiment, the case 21 has a cylindrical shape as in the first embodiment, but the arm 23 has a prismatic shape.
Also in this embodiment, the same effects as those of the first embodiment and the second embodiment described above can be obtained.
Furthermore, in the present embodiment, since the arm 23 has a prismatic shape, it is possible to obtain an anti-rotation effect with respect to the case 21, and the anti-rotation mechanism by the key groove 243 and the key member 244 of the first embodiment described above. Can be omitted.

[Fifth Embodiment]
9 and 10 show a fifth embodiment of the present invention.
The tool holder 20 of the present embodiment has the same configuration as that of the first embodiment described above, as well as the second embodiment described above, and has a pair of tools 18 mounted on opposite sides. However, each cutting tool 18 is mounted in the vertical direction (similar to the third embodiment). Furthermore, in this embodiment, the case 21 is cylindrical as in the first embodiment, but the arm 23 is in the shape of a prism (similar to the fourth embodiment).
Also in this embodiment, the same effects as those of the first embodiment and the second embodiment described above can be obtained.
Furthermore, in the present embodiment, the effects described in the respective embodiments can be obtained with the same configuration as that of the third and fourth embodiments described above.

[Sixth Embodiment]
FIG. 11 shows a sixth embodiment of the present invention.
The tool holder 20A of this embodiment has the same configuration as the tool holder 20 of the first embodiment described above. For this reason, below, only a different part from 1st Embodiment mentioned above is demonstrated.
The tool holder 20 </ b> A is mounted on the spindle 17 of the machine tool, and the case is prevented from rotating with respect to the ram 16, as in the first embodiment.
In the first embodiment described above, the arm of the bite holder is provided so as to be movable back and forth in the axial direction of the main shaft 17. On the other hand, the arm 23A of the present embodiment is configured to be movable back and forth in a direction perpendicular to the radial direction of the tool holder 20A, that is, the axial direction of the main shaft 17.

As a mechanism for causing the arm 23A to advance and retreat in the crossing direction of the main shaft 17 by the rotation of the main shaft 17, for example, a pair of bevel gears that convert the rotation of the shaft connected to the main shaft 17 to the crossing direction is used. A mechanism in which an auxiliary shaft extending in the crossing direction is rotated by a gear and the male screw portion of the auxiliary shaft and the female screw portion of the arm are screwed together can be used.
Alternatively, a male screw part of the shaft connected to the main shaft 17 and an intermediate member having a female screw part screwed into the male screw part are provided, the intermediate member is a tapered cone, and the arm is brought into contact with the tapered surface of the intermediate member. A configuration in which the arm is advanced and retracted by utilizing a change in the outer diameter of the contact portion of the cone may be used.

In the present embodiment, by setting the arm 23A to the most contracted state, the radial dimension of the bite holder 20A portion, that is, the distance D1 from the tip of the bite 18 to the side surface of the opposite ram 16 in FIG. The distance D2 from the tip of the cutting tool 18 to the side surface of the opposite ram 16 (the distance D2 is the sum of the distance D1 and the stroke of the arm 23A) is maximized. can do.
By obtaining such a change in the radial dimension, for example, even if the opening diameter RN of the work 19 is small and slightly larger than the distance D1, the tool holder 20A can be introduced into the work 19; By extending the arm 23 </ b> A in the work 19, it is possible to perform internal turning with a radius RX.

[Modification]
It should be noted that the present invention is not limited to the above-described embodiment, and modifications and the like within a scope where the present invention can be achieved are included in the present invention.
For example, in the first embodiment described above, the arm 23 has a double structure of the inner cylinder 231 and the outer cylinder 232, but the arm 23 may be formed by a single cylinder.
In the first embodiment described above, the key groove 243 and the key member 244 are used as the rotation prevention mechanism of the drive mechanism 24. However, the rotation prevention mechanism may have other configurations as long as the arm 23 can be prevented from rotating with respect to the case 21. May be used. For example, protrusions extending in the longitudinal direction are formed on the inner surface of the case 21 and the outer surface of the arm 23, or the case 21 and the arm 23 are rectangular in cross section as in the fourth and fifth embodiments described above. By doing so, the anti-rotation function may be secured.

Furthermore, in the sixth embodiment described above, the arm 23A is advanced and retracted in the direction orthogonal to the main shaft 17, but not limited to a right angle, but in a direction inclined with respect to the axial direction of the main shaft 17 (for example, diagonally downward in FIG. 11). It may be advanced or retreated.
Further, in the sixth embodiment described above, the arm 23A is advanced in only one direction, but a plurality of arms may be installed in a radial manner, and each may be advanced and retracted in synchronization.

In each of the above embodiments, the tool holders 20 and 20A may be formed with a series of passages from the taper shank 222 to the support member 233 of the tool 18 through the shaft 20 and the arms 23 and 23A. The coolant or air to be supplied can be supplied to the cutting tool 18 and the work 19. At this time, it is desirable to employ a flexible joint or the like that can be displaced in the moving direction of the arms 23 and 23A and allow the shaft 20 to rotate between the shaft 20 and the arms 23 and 23A.
In each of the embodiments described above, the turning center 10 having the column 13 is used as a machine tool. However, it may be a portal type or other types, and a machine capable of performing similar turning without using a device called a turning center. If it is a machine, the tool holder 20 of this invention is applicable. Further, in the machine tool, the direction of the main shaft 17 is not limited to the vertical direction and may be a horizontal type, and the bite holder 20 of the present invention can be similarly applied.

DESCRIPTION OF SYMBOLS 10 ... Turning center 11 ... Base 12 ... Table 13 ... Column 14 ... Boom 15 ... Spindle head 16 ... Ram 17 ... Spindle 171 ... Collet chuck 18 ... Tool bit 19 ... Work 20, 20A ... Tool holder 21 ... Case 211 ... Flange 212 ... Auxiliary shank 22 ... Shaft 221 ... Ball bearing 222 ... Taper shank 23, 23A ... Arm 231 ... Inner cylinder 232 ... Outer cylinder 233 ... Support member 24 ... Drive mechanism 241 ... Male thread 242 ... Female thread 243 ... Key groove 244 ... Key member

Claims (6)

A tool holder mounted on a spindle supported by a spindle head and supporting a turning tool,
A shaft connected to the main shaft, a case rotatably supporting the shaft and connected to the main shaft head, an arm supported so as to be able to advance and retreat from the case and supporting the bite, and the shaft relative to the case And a driving mechanism for moving the arm forward and backward by rotation of the tool holder. In the bite holder according to claim 1,
The bite holder, wherein the arm and the shaft are arranged on an axis of the main shaft, and the arm can advance and retreat in an axial direction of the main shaft. In the tool holder according to claim 2,
The drive mechanism includes a male screw part formed on the shaft, a female screw part formed on the arm and screwed into the male screw part, and a rotation prevention mechanism that prevents the arm from rotating with respect to the case. Tool holder characterized by In the bite holder according to claim 1,
The tool holder according to claim 1, wherein the shaft is disposed on an axis of the main shaft, and the arm is movable back and forth in an intersecting direction with the axis of the main shaft. In the bite holder according to any one of claims 1 to 4,
A pair of bite holders mounted in opposite directions. A turning method for turning a workpiece using a machine tool having a ram supported by a spindle head so as to freely advance and retract, and a spindle supported by the ram,
A turning method comprising mounting the tool holder according to any one of claims 1 to 4 on the main shaft, and synchronizing the advance of the arm in the tool holder and the advance of the ram in the machine tool. .

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