JP2002126919A - Chuck device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable smooth release of grasping of a work by preventing the occurrence of a phenomenon that the inner peripheral taper surface part of a sleeve bites the outer peripheral taper surface part of a collet. SOLUTION: The collet 31 has a grasping part 34 capable of being decreased in a diameter by an expanding slot 33 axially formed and grasping a work through a decrease in a diameter toward the inner peripheral side and is provided on the outer peripheral side with an outer peripheral taper surface part 35. The expanding slot 33 is closed by a sealant 36 having elasticity. A sleeve 32 is axially movably formed in the collet 31. The sleeve 32 has an inner peripheral taper surface part 37 fitted in an outer peripheral taper surface part 35 of he collet 31. A lubricant storing part 38 to store a lubricant is formed in a groove-form state or a coarse surface-form state in the outer peripheral taper surface part 35 of the collet 31. Biting of the inner peripheral taper surface part of the sleeve is prevented from occurring by the lubricant storing part 38.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a chuck device having a collet and a sleeve.

[0002]

2. Description of the Related Art As shown in FIG. 5, an outer peripheral tapered surface portion 14 is formed on the outer peripheral side of a collet 11 at a rear side of a front end cylindrical portion 12 through a step portion 13, and a front end cylindrical portion 12 and an outer peripheral tapered surface portion are formed. On the inner peripheral side of the workpiece 14, a workpiece gripping part 15 having wear resistance is integrally provided. These and the front part of the cylindrical portion 16 are provided so as to be able to reduce the diameter by three axially-divided grooves 17 that divide the entire circumference into three equal parts.

A sleeve 21 is fitted to the outside of the collet 11 so as to be movable in the axial direction. An inner peripheral tapered surface portion 22 is provided at a front opening of the sleeve 21. It is fitted with the tapered surface portion 14.

The sleeve 21 is urged rightward by a spring (not shown), and is pressed leftward against the spring by a hydraulic cylinder (not shown) or the like.

Further, a rear cylinder 23 is fitted to the outside of the cylinder of the sleeve 21 from the rear, and
The front cylindrical body 24 is fitted from the front, and the stepped portion 13 of the collet 11 is locked at the front surface of the front cylindrical body 24 by screwing of the screw portions 25 of both. A pin 26 for transmitting the applied rotation to the sleeve 21 is fitted to the rear cylinder 23.

When a round bar-shaped workpiece is inserted into the workpiece holding portion 15 of the collet 11 and the sleeve 21 is pressed leftward against a spring by a hydraulic cylinder or the like (not shown), the inner periphery of the sleeve 21 is pressed. Collet 11 from tapered surface 22
A force in the radial direction acts on the workpiece gripping portion 15 via the outer peripheral tapered surface portion 14, and the workpiece can be gripped by the workpiece gripping portion 15 divided into three.

At the time of machining, the rotation imparted to the rear cylinder 23 is transmitted to the collet 11 via the sleeve 21 and the workpiece gripped by the workpiece gripping portion 15 of the collet 11 is rotated. It is turned with a cutting tool.

After the machining is completed, the sleeve 21 is retracted rightward by a spring (not shown), the inner tapered surface 22 of the sleeve 21 is released from the outer tapered surface 14 of the collet 11, and the sleeve 21 is contracted to the work grip 15. The radial force is released, and the workpiece gripping by the workpiece gripper 15 is released.

[0009]

As described above, when releasing the gripping of the workpiece, the sleeve 21 is retracted to the right by a spring, so that the inner peripheral tapered surface portion 22 of the sleeve 21 is fixed to the outer tapered surface portion of the collet 11. Release from 14, but
A phenomenon may occur in which the inner peripheral tapered surface portion 22 of the sleeve 21 is difficult to retreat from the outer peripheral tapered surface portion 14 of the collet 11, and the workpiece may not be released smoothly.

For example, as shown in FIG. 6 (A), the taper inclination angles of the inner peripheral taper surface portion 22 of the sleeve 21 are different from each other so that the distal end of the inner peripheral taper surface portion 22 contacts the outer peripheral taper surface portion 14 of the collet 11. However, it is necessary to effectively reduce the diameter of the collet 11 when gripping the workpiece, but when the sleeve 21 is new, the edge 27 may stand at the tip of the inner peripheral tapered surface portion 22. The edge 27 makes the sleeve 21 slippery, and the collet 11 becomes harder to open. In order to cope with this, the edge 21 at the tip of the sleeve 21 is removed.

Further, as shown in FIG. 6 (B), by continuously using the collet 11, the tip of the inner peripheral tapered surface portion 22 of the sleeve 21 is worn, and the worn portion 28 When the taper angle is the same as that of the outer peripheral tapered surface portion 14, a phenomenon occurs in which the wear portions 28 bite into the outer peripheral tapered surface portion 14 of the collet 11, which hinders the retreating operation of the sleeve 21, and the opening of the collet 11 deteriorates. . In order to cope with this, the sleeve 21 is replaced, or the outer peripheral taper surface portion 14 of the collet 11 or the inner peripheral taper surface portion 22 of the sleeve 21 is shaved, and a correction operation is performed so that the taper inclination angles of the two are different. .

As described above, conventionally, even when an attempt is made to release the gripping of the workpiece, a phenomenon occurs in which the inner peripheral tapered surface portion 22 of the sleeve 21 does not easily recede from the outer peripheral tapered surface portion 14 of the collet 11. When the tip portion of the inner peripheral tapered surface portion 22 is worn and has the same taper angle as the outer peripheral tapered surface portion 14 of the collet 11, the phenomenon that the inner peripheral tapered surface portion 22 of the sleeve 21 bites the outer peripheral tapered surface portion 14 of the collet 11, The spring 21 hinders the retreating operation of the sleeve 21, making it impossible to smoothly release the gripping of the workpiece, and the correction work for solving the problem is not easy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and prevents a phenomenon in which an inner peripheral tapered surface portion of a sleeve bites on an outer peripheral tapered surface portion of a collet so that a workpiece can be smoothly released. It is intended to do so.

[0014]

According to the first aspect of the present invention, there is provided a gripping portion which can be reduced in diameter by a split groove formed in the axial direction and has a gripping portion on the inner peripheral side for gripping a workpiece by reducing the diameter. A collet having an outer peripheral tapered surface portion on the side, and a sleeve having an inner peripheral tapered surface portion provided to be axially movable with respect to the collet and fitted with the outer peripheral tapered surface portion of the collet. A chuck device in which a lubricant storage portion for storing lubricant is formed on at least one of the peripheral tapered surface portions, and the lubricant stored in the lubricant storage portion is supplied to the outer peripheral tapered surface portion of the collet and the inner circumference of the sleeve. Even if abrasion occurs at the tip of the inner peripheral tapered surface of the sleeve by supplying it for a long time between the tapered surface and the tapered surface, the inner peripheral tapered surface of the sleeve is To prevent the food stick phenomenon periphery tapered surface portion, to ensure stable sliding sleeve, to allow the release of the workpiece gripping smoothly over a long period of time.

According to a second aspect of the present invention, in the chuck device according to the first aspect, the split groove of the collet is closed by an elastic sealing material, and the collet is stored in the lubricant storing section. The sealant prevents the lubricated lubricant from leaking to the workpiece side through the collet split groove,
By supplying lubricant between the outer tapered surface of the collet and the inner tapered surface of the sleeve for a long period of time, even if abrasion occurs at the tip of the inner tapered surface of the sleeve, the inner tapered surface of the sleeve A phenomenon in which the surface portion sticks to the outer peripheral tapered surface portion of the collet is prevented, the stable sliding of the sleeve is ensured, and the gripping of the workpiece can be smoothly released for a longer period of time.

According to a third aspect of the present invention, in the chuck device according to the first or second aspect, the lubricant storage portion is formed by a surface treatment, and the lubricant storage portion formed by the surface treatment is provided. By gradually supplying the lubricant stored in the portion between the outer peripheral tapered surface portion of the collet and the inner peripheral tapered surface portion of the sleeve, the inner peripheral tapered surface portion of the sleeve is improved in sliding, and the inner peripheral tapered surface portion is formed. A phenomenon in which the outer peripheral tapered surface of the collet is bitten is prevented, so that the gripping of the workpiece can be smoothly released.

According to a fourth aspect of the present invention, in the chuck device according to the first or second aspect, the lubricant reservoir is formed by the shape of the outer peripheral tapered surface of the collet and the shape of the inner peripheral tapered surface of the sleeve. The lubrication stored in the partially formed gap-shaped lubricant storage portion is formed between the outer peripheral tapered surface of the collet and the inner circumference tapered surface of the sleeve. Agent
A phenomenon in which the inner peripheral taper surface of the sleeve is slid better by gradually supplying between the outer peripheral taper surface of the collet and the inner peripheral taper surface of the sleeve, and the inner peripheral taper surface bites into the outer peripheral taper surface of the collet. To prevent the workpiece from being gripped smoothly.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIG. 1, a second embodiment with reference to FIG. 2, and a third embodiment with reference to FIG. The fourth embodiment will be described with reference to FIG.

FIG. 1 shows a first embodiment, in which a sleeve for reducing the diameter of a collet is provided outside a collet 31 for gripping a workpiece.
32 is fitted.

The collet 31 has a split groove 33 formed in the axial direction, the diameter of which can be reduced by the split groove 33. The collet 31 has a grip portion 34 for gripping a workpiece by reducing the diameter on the inner peripheral side, and has an outer peripheral portion on the outer peripheral side. It has a tapered surface portion 35.

The split groove 33 of the collet 31 is closed by a sealing material 36 such as silicone rubber having elasticity.

The sleeve 32 is provided so as to be movable in the axial direction with respect to the collet 31, and the outer peripheral tapered surface portion 35 of the collet 31 is provided.
And an inner peripheral tapered surface portion 37 that fits with the inner peripheral surface. This sleeve 32
1 is biased rightward in FIG. 1 by a spring (not shown), and is pressed leftward in FIG. 1 by a pressing force against the spring by a hydraulic cylinder (not shown) to reduce the diameter of the collet 31.

On the outer peripheral tapered surface portion 35 of the collet 31, a lubricant storing portion 38 for storing a lubricant such as grease is formed. The lubricant reservoir 38 is used for scribing with a sharp-pointed tool, grinding with a grindstone attached to a rotary tool such as a luter, cutting with a milling cutter, forming a fine groove or rough surface by sandblasting, film or It is formed into a groove or a rough surface by surface treatment by coating, and functions as an oil pot.

When the lubricant storage section 38 is formed as a groove, it is a groove, a long groove, a circular groove, a shaving-like cut groove or the like, and the groove includes a knurl groove or the like. When machining these grooves and rough surfaces, if the grooves and rough surfaces remain even after polishing the outer circumferential taper portions 35 of the collets 31 in which the grooves and rough surfaces have been machined, the outer circumferential taper surfaces 35 of the collet 31 The contact of the sleeve 32 with the inner peripheral tapered surface 37 can be maintained with high accuracy.

It should be noted that the lubricant reservoir 38 is
Although it may be formed on the inner peripheral tapered surface portion 37 of the collet 31, it is easier to process the outer peripheral tapered surface portion 35 of the collet 31.

Then, lubricant such as grease stored in a lubricant storage portion 38 formed in a groove shape or a rough surface shape is
By gradually supplying between the outer peripheral taper surface portion 35 of the collet 31 and the inner peripheral taper surface portion 37 of the sleeve 32, even when the tip of the inner peripheral taper surface portion 37 of the sleeve 32 wears, the sleeve 32 is The inner peripheral tapered surface portion 37 is improved in slippage, the tip of the inner peripheral tapered surface portion 37 is prevented from sticking to the outer peripheral tapered surface portion 35 of the collet 31, and the stable sliding of the sleeve 32 is ensured. The workpiece can be smoothly released from being held over a period of time.

At this time, the sealing material 36 prevents the lubricant from leaking to the workpiece through the split groove 33 of the collet 31 and suppresses the consumption of the lubricant stored in the lubricant storing section 38 as much as possible. Thus, the lubricant is supplied over a long period of time, and the work is prevented from slipping and becoming dirty due to the lubricant.

Next, FIG. 2 shows a second embodiment. The same parts as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

On the outer peripheral tapered surface 35 of the collet 31, a number of X-shaped groove-shaped lubricant storing portions 38 for storing lubricant are formed.

These lubricant storing portions 38 are formed in the same pattern between the split grooves 33, and the larger the diameter of the outer peripheral tapered surface portion 35 which the front end portion of the inner peripheral tapered surface portion of the sleeve contacts, the larger the lubricant storing portion 38. The storage part 38 is formed, and the larger the diameter, the more the lubricant is stored.

By supplying the lubricant between the outer peripheral tapered surface portion 35 of the collet 31 and the inner peripheral tapered surface portion of the sleeve from the lubricant storing portion 38 arranged over the entire circumference, the inner peripheral tapered surface portion of the sleeve is formed. Outer peripheral tapered surface of collet 31
The phenomenon of biting the workpiece 35 is surely prevented so that the gripping of the workpiece can be smoothly released.

FIG. 3 shows a third embodiment. The same parts as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

A large number of I-shaped groove-shaped lubricant storing portions 38 for storing lubricant are formed only in the large-diameter portion of the outer peripheral tapered surface portion 35 of the collet 31.

Such an I-shaped groove-shaped lubricant reservoir 38 is
By using a splitter used when manufacturing gears,
It can be formed evenly at a predetermined place between the split grooves 33.

By supplying a lubricant between the outer peripheral tapered surface 35 of the collet 31 and the inner peripheral tapered surface of the sleeve from the lubricant reservoir 38 formed in an I-shaped groove shape, the inner peripheral taper of the sleeve is supplied. The phenomenon that the front end of the surface portion sticks to the outer peripheral tapered surface portion 35 of the collet 31 is reliably prevented, so that the gripping of the workpiece can be smoothly released.

In particular, since the tip of the inner peripheral tapered surface of the sleeve may bite into the large-diameter portion of the outer tapered surface 35 of the collet 31, the lubricant is supplied from the large-diameter lubricant reservoir 38. Thus, biting can be reliably prevented.

Next, FIG. 4 shows a fourth embodiment. The same parts as those in the first embodiment shown in FIG. 1 are denoted by the same reference numerals.

The collet 31 has a split groove 33 formed in the axial direction.
, And has a grip portion 34 for gripping a workpiece by reducing the diameter on the inner peripheral side, and has an outer tapered surface portion 35 on the outer peripheral side.

The sleeve 32 movably provided in the axial direction with respect to the collet 31 is provided with an outer tapered surface portion 35 of the collet 31.
And an inner peripheral tapered surface portion 37 that fits with the inner peripheral surface.

The outer tapered surface 35 of the collet 31 is formed not to be a perfect circle, but to have a slightly larger diameter between the three split grooves 33 than the three split grooves 33, and to form the inner circumferential taper of the sleeve 32. By making contact with the surface portion 37, the diameter reduction operation of the collet 31 by the sleeve 32 is configured to be performed smoothly, but the outer peripheral tapered surface portion 35 of the collet 31 is partially The surface of the outer peripheral taper surface 35 of the collet 31 and the sleeve 32
Depending on the shape of the inner peripheral taper surface portion 37, the outer peripheral taper surface portion 35 of these collets 31 and the inner peripheral taper surface portion of the sleeve 32
A gap-shaped lubricant reservoir partly formed between 37 and
38 is provided, and a lubricant such as grease is stored in these lubricant storing sections 38.

The split groove 33 of the collet 31 is closed by an elastic sealing material 36, and the lubricant stored in the lubricant storage section 38 leaks to the workpiece through the split groove 33 of the collet 31. Is prevented by the sealing material 36.

Then, the lubricant stored in the partially formed lubricant storage portion 38 in the form of a gap is brought into contact between the outer peripheral tapered surface portion 35 of the collet 31 and the inner peripheral tapered surface portion 37 of the sleeve 32. By gradually supplying to the portion 39 over a long period of time, even if the contact portion 39 or the like is worn, the inner peripheral tapered surface portion 37 of the sleeve 32 can be smoothly slid and the inner peripheral tapered surface portion can be improved.
This prevents the phenomenon in which the outer peripheral tapered surface portion 35 of the collet 31 bites, thereby ensuring stable sliding of the sleeve 32 and smoothly releasing the workpiece from being gripped for a long period of time.

[0043]

According to the first aspect of the present invention, the lubricant stored in the lubricant storage portion is supplied between the outer peripheral tapered surface of the collet and the inner peripheral tapered surface of the sleeve for a long period of time. Therefore, even if the tip of the inner peripheral taper surface of the sleeve is worn, the phenomenon that the inner peripheral taper surface of the sleeve does not bite into the outer taper surface of the collet can be prevented, and the sleeve can be reliably slid. The grip of the workpiece can be smoothly released over a long period of time.

According to the second aspect of the present invention, the possibility that the lubricant stored in the lubricant storage portion leaks to the workpiece through the split groove of the collet is prevented by the seal material, and the outer peripheral tapered surface portion of the collet is prevented. By supplying lubricant between the inner peripheral taper surface of the sleeve and the inner peripheral taper surface of the sleeve for a long period of time, even if the tip of the inner peripheral taper surface of the sleeve wears, the inner peripheral taper surface of the sleeve keeps the outer peripheral surface of the collet. The phenomenon of sticking to the tapered surface portion can be prevented, the stable sliding of the sleeve can be ensured, and the grip of the workpiece can be smoothly released for a longer period of time.

According to the third aspect of the present invention, the lubricant stored in the lubricant storage formed by the surface treatment is
By gradually supplying between the outer peripheral taper surface of the collet and the inner peripheral taper surface of the sleeve, the inner peripheral taper surface of the sleeve slides better, and the inner taper surface bites into the outer taper surface of the collet. Is prevented, and the grip of the workpiece can be smoothly released.

According to the fourth aspect of the present invention, the lubricant stored in the gap-shaped lubricant storage portion formed partially by the shape of the outer peripheral tapered surface of the collet and the shape of the inner peripheral tapered surface of the sleeve. Is gradually supplied between the outer peripheral taper surface of the collet and the inner peripheral taper surface of the sleeve to improve the slip of the inner peripheral taper surface of the sleeve. The sticking phenomenon can be prevented, and the grip of the workpiece can be released smoothly.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a chuck device according to the present invention.

FIG. 2 is a perspective view of a collet showing a second embodiment of the same chuck device.

FIG. 3 is a perspective view of a collet showing a third embodiment of the same chuck device.

FIG. 4 is a cross-sectional view showing a fourth embodiment of the same chuck device.

FIG. 5 is a sectional view showing a conventional chuck device.

FIG. 6A is a cross-sectional view showing a problem due to an edge of a conventional chuck device, and FIG. 6B is a cross-sectional view showing a problem due to wear of a sleeve in the conventional chuck device.

[Explanation of symbols]

 31 Collet 32 Sleeve 33 Split groove 34 Gripping part 35 Outer tapered surface part 36 Seal material 37 Inner peripheral tapered surface part 38 Lubricant storage part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tatsuo Okubo 116 Manganji, Hino-shi, Tokyo F term in Okubo Technical Service Co., Ltd. (reference) 3C032 JJ01 JJ08

Claims (4)

[Claims] 1. A collet having a gripper for reducing a diameter by a split groove formed in an axial direction and having a gripping part on an inner peripheral side for gripping a workpiece and having an outer tapered surface part on an outer peripheral side, and a shaft with respect to the collet. A sleeve having an inner peripheral tapered surface portion which is provided so as to be movable in the direction and which is fitted to the outer peripheral tapered surface portion of the collet; and a lubrication agent for storing a lubricant in at least one of the outer peripheral tapered surface portion of the collet and the inner peripheral tapered surface portion of the sleeve. A chuck device, wherein a drug reservoir is formed. 2. The chuck device according to claim 1, wherein the split groove of the collet is closed by an elastic sealing material. 3. The chuck device according to claim 1, wherein the lubricant reservoir is formed by a surface treatment. 4. The lubricant reservoir is partially formed between an outer tapered surface of the collet and an inner tapered surface of the sleeve, depending on the shape of the outer tapered surface of the collet and the shape of the inner tapered surface of the sleeve. 3. The chuck device according to claim 1, wherein the chuck device is formed in a gap shape.