JP5764588B2 - Work fixing method and work holding device - Google Patents

Description

The present invention relates to a work fixing method and a work holding device that supports a work.

In order to cut a rod-shaped workpiece with a lathe, there is a method in which a workpiece fixed to the spindle unit is rotated together with the spindle unit, and a machining blade is brought into contact with the workpiece. When this method is adopted, one spindle unit can be used for workpieces of various lengths by designing the spindle unit so that workpieces having different lengths can be fixed. And the specific example of such a spindle unit is described in patent documents 1, 2, for example.

The spindle unit described in Patent Documents 1 and 2 includes a support that can be adjusted in position along the longitudinal direction of the workpiece and fixed in contact with the rear end of the workpiece, and a chuck that holds the workpiece is attached to the front side. To fix workpieces of different lengths. The reason why the work is fixed using the support in addition to the chuck is to enable the work to be kept fixed even when the work is rotated at a high speed (for example, 8,000 rpm).
Although there is no clear description in Patent Documents 1 and 2, the workpiece is inserted from the front of the spindle unit into the workpiece mounting hole of the chuck in an expanded state, and is gripped by the chuck by reducing the diameter of the workpiece mounting hole. Is done.

JP-A-6-328305 JP-A-10-202404

However, the chuck generally has a structure in which the workpiece mounting hole is not greatly expanded due to the rotational balance when the workpiece is rotated at a high speed. For this reason, the workpiece | work which has a site | part wider than the front side, for example, a bowl-shaped site | part, on the back side had the subject that the site | part cannot pass a workpiece | work attachment hole, and was not attached to a chuck | zipper.
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a workpiece fixing method and a workpiece holding device for fixing a workpiece having a rear part wider than the front side.

The work fixing method according to the first aspect of the present invention is to fix a work in which a work attachment hole is formed and the work is held by a chuck attached to the main spindle unit, and a support member of the main spindle unit is brought into contact with the work. In the method, the workpiece having a rod-shaped portion on the front side and a widened portion wider than the rod-shaped portion on the rear side is temporarily fixed to the chuck by inserting the rod-shaped portion into the workpiece mounting hole from the rear of the chuck. A step of temporarily fixing the chuck to the spindle unit via a collet body fixed to the spindle unit, and adjusting the position of the support along the rod-shaped portion of the workpiece to contact the workpiece And fixing the support, and fixing the chuck to the spindle unit and fixing the workpiece to the chuck.

In the workpiece fixing method according to the first aspect of the present invention, it is preferable that the workpiece is positioned with respect to the spindle unit by adjusting a fixing position of the collet body to the spindle unit.

In the work fixing method according to the first aspect of the present invention, a collet nut for fixing the chuck to the collet body is provided, and the main stop of the chuck to the spindle unit and the main stop of the work to the chuck are: It is preferably performed by tightening the collet nut to the shut-off position.

In the workpiece fixing method according to the first aspect of the present invention, it is preferable that the chuck is temporarily fixed to the spindle unit by temporarily fixing the chuck to the collet body with the collet nut.

A workpiece holding device according to a second invention that meets the above-described object is provided with a spindle unit that is rotatably supported by a bearing block, and a workpiece attachment hole that is attached to the spindle unit and can be adjusted in diameter. In a work holding device having a chuck, a collet body fixed to the spindle unit by a screw member is provided, and the collet body is larger than the work mounting hole whose diameter is expanded to an upper limit, and is penetrated through which the chuck is fitted. It has a hole A and a through hole B that is larger than the outer diameter of the screw member and through which the screw member is inserted.

In the work holding device according to the second invention, the spindle unit is disposed along the rotation axis of the spindle unit, and has a rod-like member having a first screw structure on one side, and the first screw structure. A second screw structure that meshes, and a support member that contacts the work in a direction along a rotation axis of the main spindle unit in a state of being attached to the rod-like member and fixes the work together with the chuck. Is preferred.

In the work holding device according to the second invention, the spindle unit is formed with a through-hole C through which the rod-shaped member is inserted, and the spindle unit is adjusted in position along the rotation axis of the spindle unit. Positioning means for fixing the rod-shaped member, and three or more vibration preventing means for suppressing vibration of the rod-shaped member due to rotation of the spindle unit, and at least two of the vibration preventing means are fixed positions of the rod-shaped member. Regardless, it is preferably provided at a position where vibration of the rod-like member can be suppressed.

The workpiece fixing method according to the first invention includes a step of inserting the workpiece rod-shaped portion into the workpiece attachment hole from the rear of the chuck to temporarily fix the workpiece to the chuck, and a collet body fixed to the spindle unit. There are a step of temporarily fixing the chuck to the spindle unit, a step of permanently fixing the chuck to the spindle unit, and a step of permanently fixing the workpiece to the chuck unit. Therefore, it is possible to fix a work having a part that cannot pass through the work attachment hole on the rear side.

The work holding device according to the second invention is provided with a collet body fixed to the spindle unit by a screw member, and the collet body is larger than the work mounting hole whose diameter is expanded to the upper limit, and the through hole A into which the chuck is fitted. Therefore, a workpiece having a part wider on the rear side than the front side can be gripped by the chuck by inserting the front side through the workpiece attachment hole from the rear side of the chuck. Therefore, it is possible to fix a work having a part that cannot pass through the work attachment hole on the rear side.
Further, the collet body is larger than the outer diameter of the screw member that fixes the collet body to the spindle unit, and has a through hole B through which the screw member is inserted, so that the position for fixing the collet body to the spindle unit can be adjusted, The gripped work can be positioned. For this reason, the workpiece can be reliably positioned on the rotary shaft of the spindle unit and can be rotated stably.

It is a sectional side view of the workpiece holding device concerning a 1st embodiment of the present invention. It is a partially expanded side sectional view of the work holding device. It is a sectional side view which shows the state which the workpiece holding apparatus fixed the workpiece | work from which length differs. (A)-(C) are explanatory drawings which show the fixing method of the workpiece | work which concerns on the 2nd Embodiment of this invention.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
As shown in FIGS. 1 and 2, a workpiece holding device 10 according to a first embodiment of the present invention includes a spindle unit 12 that is rotatably supported by a bearing block 11, a spindle unit 12, and a workpiece The apparatus has a chuck 14 in which a mounting hole 13 is formed, and fixes the workpiece 15. Details will be described below.

As shown in FIG. 1, the spindle unit 12 is rotatably supported by a bearing block 11, is given a driving force from a motor (not shown), and rotates together with a work 15 fixed to the spindle unit 12 via a chuck 14. .
As illustrated in FIG. 2, the workpiece 15 includes a rod-shaped portion 16 that is gripped by the chuck 14 and a flange portion (an example of a widened portion) 17 that is continuous with the rod-shaped portion 16.

The rod-like portion 16 of the work 15 is gripped and fixed by the chuck 14 with one end projecting from the chuck 14 and a portion continuing to the projecting one end stored in the work mounting hole 13 of the chuck 14. Then, when the workpiece 15 rotates integrally with the spindle unit 12, the portion of the rod-like portion 16 protruding from the chuck 14 is processed by a cutting machine (not shown).

As shown in FIG. 1, the main shaft unit 12 includes a long and cylindrical hollow rotating body 18 and a rod-shaped member 20 through which a through hole 19 (through hole C) formed in the hollow rotating body 18 is inserted. .
The hollow rotating body 18 is supported by the bearing block 11 so as not to move in the longitudinal direction (axial direction), and one side in the longitudinal direction is designed so that the chuck 14 can be attached. With the longitudinal direction of the main spindle unit 12 as the front-rear direction and the side on which the chuck 14 is attached as the front side, the hollow rotating body 18 has a wide front portion protruding from the bearing block 11 and mainly includes a plurality of metal blocks. And a plurality of screw members for fixing individual metal blocks to adjacent metal blocks. The hollow rotating body 18 is formed such that the rear side of the front portion protruding from the bearing block 11 is long in the front-rear direction and is rotatably supported by the bearing block 11.

The rod-shaped member 20 is disposed along the rotation axis of the spindle unit 12 (a fixed straight line that becomes the center when the spindle unit 12 rotates), and on the front side (one side), the first screw structure shown in FIG. Is provided with a male screw structure on the rear side (other side), and two nuts 22 and 23 as an example of positioning means are attached to the male screw structure on the rear side. The nuts 22 and 23 fix the rod-shaped member 20 to the hollow rotating body 18 by so-called double nuts, and the main shaft unit 12 rotates to prevent the rod-shaped member 20 from being loosely fixed to the hollow rotating body 18. .
In the present embodiment, the rotation axis of the spindle unit 12 and the axis of the spindle unit 12 are coincident, but it is not always necessary to coincide.

The rod-shaped member 20 can move with respect to the hollow rotating body 18 by loosening the nut 23 and can be adjusted in position along the rotation axis of the main spindle unit 12, and can be rotated hollow by tightening the nuts 22 and 23. Fixed to the body 18 and positioned.
The rod-shaped member 20 is positioned according to the length of the workpiece attached to the workpiece holding device 10, and as shown in FIG. 3, when the workpiece 24 having a longer rod-shaped portion than the workpiece 15 is attached, the workpiece 15 is attached. Also, the rod-shaped member 20 is fixed at the retracted position.

Further, as shown in FIG. 2, a support 26 having a male screw structure 25 that is a second screw structure that meshes with the female screw structure 21 is fitted into the female screw structure 21 of the rod-shaped member 20.
The support 26 fixes the workpiece 15 together with the chuck 14, and the support 26 attached to the rod-shaped member 20 moves back and forth integrally with the rod-shaped member 20 by adjusting the position of the rod-shaped member 20. It contacts the gripped work 15 from the rear side. Accordingly, the support 26 moves along the rotation axis of the main spindle unit 12 and comes into contact with the workpiece 15 in the direction along the rotation axis.

Since the workpiece 15 is in contact with the rear end of the flange portion 17, the workpiece 15 does not move backward even if the cutting machine is pressed from the front side.
Note that when the work 24 is attached to the work holding device 10 instead of the work 15, the fixing method is the same as that for fixing the work 15, and as shown in FIG. Is held, and the support 26 is brought into contact with the buttocks of the work 24. Hereinafter, the relationship between the members of the work holding device 10 is basically the same between the case of attaching the work 15 and the case of attaching the work 24 except that the fixing position of the rod-like member 20 to the hollow rotating body 18 is different. is there.

While processing the workpiece 15, the support tool 26 contacts the workpiece 15. Therefore, the support 26 is made of a material having a hardness lower than that of the work 15, and measures are taken so as not to damage the work 15. The support tool 26 is formed of gun metal, which is an example of metal, and is hardened to take measures to suppress wear. However, the support tool 26 is worn faster than other members, and the replacement cycle is short. .
Therefore, the rod-shaped member 20 and the support tool 26 are provided on the female screw structure 21 provided on the rod-shaped member 20 and the support tool 26 so that the support tool 26 can be easily attached to and detached from the rod-shaped member 20. The male screw structure 25 is designed to be connectable. The support tool 26 is formed with a flat portion 27 that is gripped by a spanner, which is an example of a tool. Therefore, torque can be applied to the support tool 26 with the spanner, and the support tool 26 can be easily replaced. Can be done.
In addition, the relationship between the male screw and the female screw in the first and second screw structures may be reversed, the first screw structure may be a male screw structure, and the second screw structure may be a female screw structure.

As shown in FIGS. 1 and 3, the spindle unit 12 is provided with three vibration preventing means for suppressing the rod-like member 20 from vibrating due to the rotation of the spindle unit 12. In the present embodiment, of the three vibration preventing means, two are sliding bearings (an example of bearings) 28 and 29 provided in the through hole 19, and one is an O-ring 30 attached to the rod-shaped member 20. . For this reason, the vibration preventing means can be configured without using a special member, and the procurement cost of the vibration preventing means can be suppressed.

The rod-shaped member 20 has a region having a smaller diameter than the other regions on the front side, and the slide bearing 28 and the slide bearing 29 provided behind the rod-shaped member 20 have a smaller diameter than the rod-shaped member 20. It is arranged at a position where it can contact only the region. The sliding bearings 28 and 29 are in a state in which vibration of the rod-shaped member 20 can be suppressed by contacting the rod-shaped member 20.
When the work fixed to the work holding device 10 is short in the front-rear direction, the slide bearing 28 abuts on the rod-shaped member 20 as shown in FIG. 1, and when the work is long in the front-rear direction, as shown in FIG. The slide bearing 28 does not come into contact with the rod-shaped member 20.
On the other hand, as shown in FIGS. 1 and 3, the plain bearing 29 contacts the rod-shaped member 20 regardless of the length of the workpiece fixed to the workpiece holding device 10 in the front-rear direction.

The O-ring 30 is attached to a portion having a larger diameter than the region behind the narrow-diameter region of the rod-shaped member 20 with which the slide bearings 28 and 29 can abut. The O-ring 30 abuts on the outer peripheral portion of the through hole 19 and suppresses vibration of the rod-shaped member 20 regardless of the length of the workpiece fixed in the workpiece holding device 10 in the front-rear direction.
Therefore, the sliding bearings 28 and 29 and the O-ring 30 are provided at positions where at least the sliding bearing 29 and the O-ring 30 can suppress the vibration of the rod-shaped member 20 regardless of the fixing position of the rod-shaped member 20. Therefore, the vibration of the rod-shaped member 20 can be reliably suppressed.

As shown in FIG. 2, the chuck 14 is designed such that the diameter of the workpiece attachment hole 13 can be adjusted. The workpiece attachment hole 13 is widened when the workpiece 15 is attached, and the diameter is reduced. The rod-shaped part 16 of the work 15 is gripped.
A collet body 32 fixed to the hollow rotator 18 can be attached to the chuck 14, and the work 15 gripped by the chuck 14 is attached to the collet body 32 to which the chuck 14 is fixed by a screw member 34. By fixing to 18, it is attached to the hollow rotating body 18. Here, the chuck 14 can be fixed to the collet body 32 by a collet nut 33 attached to the chuck 14.

The collet body 32 includes a male screw structure 36 that is disposed along the axis, has a through hole 35 (through hole A) into which the chuck 14 is fitted, and a collet nut 33 fits on the outer periphery of one side. . The through hole 35 is arranged in the front-rear direction with the collet body 32 attached to the hollow rotary body 18, and the front half is formed with a reduced diameter in the rear, and the rear half has a large diameter at different positions in the front and rear. Are the same.
The diameter of the through hole 35 is larger than that of the work mounting hole 13 whose diameter is increased to the upper limit even in the rear half portion having a small diameter. Therefore, even if the member has a size that cannot pass through the work attachment hole 13 whose diameter is expanded to the upper limit, the through hole 35 can be passed therethrough.

Therefore, the flange portion 17 of the work 15 is sized so as not to pass through the work attachment hole 13 whose diameter is increased to the upper limit, but can be accommodated inside the rear half of the through hole 35.
As shown in FIG. 3, the workpiece 24 is fixed to the workpiece holding device 10 in a state where the collar portion is disposed behind the collet body 32 and a part of the rod-shaped portion is disposed in the through hole 35.

Further, as shown in FIG. 2, the collet body 32 is formed with a bowl-shaped annular portion protruding outward in the radial direction at the center in the axial direction of the bearing block 11, and a through hole 37 ( A through hole B) is formed. The through-hole 37 is a hole through which a screw member 34 disposed parallel to the axis of the collet body 32 is inserted when the collet body 32 is attached to the hollow rotating body 18, and the outer diameter of the shaft portion of the screw member 34. Greater than. Therefore, the collet body 32 can be adjusted in a direction where the fixing position to the hollow rotating body 18 is orthogonal to the rotation axis of the main spindle unit 12.

By adjusting the fixing position of the collet body 32 to the hollow rotating body 18, the position of the work 15 gripped by the chuck 14 can be adjusted. In the embodiment, it can be positioned at the axis of the spindle unit 12. The workpiece 15 can be stably rotated because the axis of the rod-like portion 16 is disposed on the rotation axis of the main spindle unit 12, and the workpiece 15 is precisely processed by the cutting machine.
Although only one through hole 37 is shown in FIGS. 1 to 3, a plurality of through holes 37 are actually formed in the collet body 32, and the collet body 32 is securely fixed to the hollow rotating body 18. Designed.
As shown in FIG. 2, a screw hole 38 to which the screw member 34 is fixed is formed in the hollow rotating body 18.

Next, a procedure (step) for fixing the workpiece 15 to the workpiece holding device 10 by the workpiece fixing method according to the second embodiment of the present invention will be described.
(Step 1) As shown in FIG. 4A, the rod-shaped portion 16 of the workpiece 15 is inserted into the workpiece mounting hole 13 from the rear of the chuck 14 to which the collet nut 33 is mounted, and the workpiece 15 is temporarily inserted into the chuck 14. Stop.

(Step 2) As shown in FIG. 4B, approximately half of the chuck 14 to which the workpiece 15 is temporarily fixed is fitted into the through-hole 35 of the collet body 32 attached to the hollow rotating body 18, and the collet nut 33 is The chuck 15 is temporarily fixed to the collet body 32 by tightening to a position just before the closing position. Thereby, the chuck 14 is temporarily fixed to the hollow rotating body 18 via the collet body 32.
In the present embodiment, the collet body 32 is fixed to the hollow rotating body 18 by the screw member 34 before temporarily fixing the chuck 14 to the collet body 32. The member 34 may be fixed to the hollow rotating body 18.

The workpiece 15 is positioned with respect to the spindle unit 12 by adjusting the fixed position of the collet body 32 to the hollow rotating body 18 in a direction perpendicular to the rotation axis of the spindle unit 12 (a direction perpendicular to the rod-like portion 16 of the workpiece 15). Done. Specifically, the work 15 is positioned by adjusting the fixing position of the collet body 32 to the hollow rotary body 18 so that the axis of the rod-like portion 16 of the work 15 is arranged on the rotation axis of the main spindle unit 12. To do.

(Step 3) As shown in FIG. 4C, the support 26 together with the rod-shaped member 20 is moved and adjusted along the axis of the rod-shaped portion 16 of the workpiece 15 (that is, the rotation axis of the spindle unit 12). Then, after contacting the flange portion 17 of the workpiece 15, the support member 26 is fixed by fixing the rod-shaped member 20 with the nuts 22 and 23.

(Step 4) By tightening the collet nut 33 to the closing position, the chuck 14 is fixed to the collet body 32 and the chuck 14 is permanently fixed to the spindle unit 12 and the work 15 is permanently fixed to the chuck 14. Therefore, the main fastening of the chuck 14 to the spindle unit 12 and the real fastening of the workpiece 15 to the chuck 14 are performed by tightening the collet nut 33 to the shut-off position.
The chuck 14 is designed so that a backward force acts on the workpiece 15 inserted through the workpiece mounting hole 13 by tightening the collet nut 33 to the closing position. Therefore, by tightening the collet nut 33, the flange portion 17 of the work 15 is pressed against the support tool 26, and is surely in close contact with the support tool 26.

At the time of step 4, if necessary, the screw member 34 is loosened, and the position of the work 15 is adjusted by adjusting the position of the collet body 32 with respect to the spindle unit 12. When the workpiece 15 is actually rotated together with the spindle unit 12 and the workpiece 15 is shaken, the position of the workpiece 15 can be adjusted together with the collet body 32 by loosening the screw member 34.
Further, in the case of a workpiece having a long rod-like portion like the workpiece 24 shown in FIG. 3, the collar portion is arranged at the rear of the collet body even if the collar portion does not fit in the through hole 35 of the collet body 32. The workpiece can be fixed by gripping the rod-like portion with the chuck 14 in this state.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and all changes in conditions and the like that do not depart from the gist are within the scope of the present invention.
For example, the workpiece fixed by the workpiece holding device is not limited to a shape having a rod-shaped portion and a flange portion, and may have a widened portion wider than the outer diameter of the rod-shaped portion on the rear side of the rod-shaped portion.
Moreover, a rolling bearing can also be employ | adopted as a vibration prevention means, and a vibration prevention means is not limited to three, Four or more may be sufficient. Even if there are four or more vibration preventing means, at least two vibration preventing means are provided at positions where vibration of the rod-shaped member can be suppressed regardless of the fixing position of the rod-shaped member, thereby reliably suppressing vibration of the rod-shaped member. be able to.

10: Workpiece holding device, 11: Bearing block, 12: Spindle unit, 13: Workpiece mounting hole, 14: Chuck, 15: Workpiece, 16: Bar-shaped part, 17: Hook, 18: Hollow rotating body, 19: Through hole , 20: rod-shaped member, 21: female screw structure, 22, 23: nut, 24: work, 25: male screw structure, 26: support, 27: flat portion, 28, 29: plain bearing, 30: O-ring, 32: Collet body, 33: Collet nut, 34: Screw member, 35: Through hole, 36: Male screw structure, 37: Through hole, 38: Screw hole

Claims (7)

In a method of fixing a work in which a work attachment hole is formed and the work is gripped by a chuck attached to the main spindle unit, and the support of the main spindle unit is brought into contact with the work
A step of inserting the rod-shaped portion into the workpiece attachment hole from the rear of the chuck and temporarily fixing the workpiece to the chuck, the workpiece having a rod-shaped portion on the front side and a widened portion wider than the rod-shaped portion on the rear side;
Temporarily fixing the chuck to the spindle unit via a collet body fixed to the spindle unit;
Adjusting the position of the support tool along the rod-shaped portion of the work to contact the work, and fixing the support tool;
A method of fixing the workpiece to the main spindle unit and fixing the workpiece to the chuck. 2. The workpiece fixing method according to claim 1, wherein the workpiece is positioned with respect to the spindle unit by adjusting a fixing position of the collet body to the spindle unit. 3. The work fixing method according to claim 1, wherein a collet nut for fixing the chuck to the collet body is provided, and the main fixing of the chuck to the spindle unit and the main fixing of the work to the chuck are as follows: The work fixing method is performed by tightening the collet nut to a closing position. 4. The work fixing method according to claim 3, wherein the chuck is temporarily fixed to the spindle unit by temporarily fixing the chuck to the collet body by the collet nut. In a workpiece holding device having a spindle unit rotatably supported by a bearing block, and a chuck attached to the spindle unit and having a workpiece attachment hole capable of adjusting the size of the diameter,
A collet body fixed to the spindle unit by a screw member is provided, and the collet body is larger than the workpiece mounting hole whose diameter is expanded to the upper limit, and a through hole A into which the chuck is fitted, and an outer side of the screw member. A work holding device having a through-hole B larger than the diameter through which the screw member is inserted. 6. The work holding apparatus according to claim 5, wherein the main spindle unit is disposed along a rotation axis of the main spindle unit and meshes with the first screw structure with a rod-like member having a first screw structure on one side. A second screw structure, and a support that abuts the workpiece in a direction along the rotation axis of the spindle unit in a state of being attached to the rod-like member and fixes the workpiece together with the chuck. A workpiece holding device. The work holding apparatus according to claim 5 or 6, wherein the spindle unit is formed with a through hole C through which the rod-like member is inserted, and the position of the spindle unit is adjusted along the rotation axis of the spindle unit. Positioning means for fixing the rod-shaped member, and three or more vibration preventing means for suppressing vibration of the rod-shaped member due to rotation of the spindle unit, and at least two of the vibration preventing means are for fixing the rod-shaped member. A workpiece holding device, which is provided at a position where vibration of the rod-shaped member can be suppressed regardless of the position.

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