JPH06218606A - Chuck - Google Patents

Abstract

PURPOSE:To provide such a chuck that can fasten, along the axial direction, the outer circumference of a shank of a tool by uniformed force and improve holding power of the tool thereby. CONSTITUTION:A cap 13 is rotationally combined with a tapered shank 12 fixed to the rotary axis of a machine tool. A twisted coil spring 31 of which one end is held in the tapered shank 12 and the other end is held in the cap 13 is provided. The shank 14a of a tool 14 is inserted therein, the cap 13 is turned in the prescribed direction, in relation to the tapered shank and the twisted coil spring 31 is clampingly screwed so as to fix the tool 14. The twisted coil spring 31 is prevented from being wound back by a ratchet 18 serving as a one-way clutch. When the ratchet 18 is released by puling the cap 13, the twisted coil spring 31 is wound back so that the tool 14 can be removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chuck for a tool for a machine tool, and more particularly to a chuck having a novel structure which is tightened and fixed by using a torsion coil spring.

[0002]

2. Description of the Related Art Conventionally, as a chucking method for a tool for a machine tool, a method using a collet according to the shank diameter of the tool has been widely adopted. That is, on the inner circumference of the taper shank that is detachably fixed to the rotating shaft of the machine tool, a cylindrical collet with a slit formed in the axial direction to provide a spring action is arranged. It is a method of tapering the gaps between them and pressing the collet with a nut screwed to the tapered shank to reduce the diameter of the collet and tighten the outer periphery of the shank of the tool.

[0003]

However, in the above method, since it is not possible to form slits over the entire axial dimension of the collet, a uniform spring action cannot be obtained in the axial direction of the collet. For this reason, when the diameter of the collet was reduced, it was not possible to tighten the outer circumference of the tool shank with a uniform force along the axial direction. As a result, if the cutting resistance from the tool, for example the cutter side, increases,
This sometimes caused the cutter to slip, which hindered the production of parts.

Therefore, an object of the present invention is to provide a chuck which can tighten the outer periphery of a shank of a tool with a uniform force along the axial direction, thereby improving the holding force of the tool.

[0005]

In order to achieve the above object, a chuck according to the present invention has a tapered outer circumference, has a tool insertion hole therein, and is detachably fixed to a rotary shaft of a machine tool. A tapered shank, rotatably assembled to the tapered shank, and a cap having an insertion hole that communicates with the insertion hole inside, and inside the tapered shank and the cap, one end is held on the tapered shank side, The other end is held by the cap side, and the middle part is inserted into the inside of the torsion coil spring positioned on the outer circumference of the tool, and the cap is rotated in a predetermined direction with respect to the taper shank to wind the torsion coil spring. When tightened, the rotation stop mechanism to prevent the torsion coil spring from rewinding and the stopping force by this rotation stop mechanism Dividing it, characterized in that it comprises a mechanism for rewinding the torsion coil spring.

In a preferred aspect of the present invention, the detent mechanism comprises a ratchet provided at a fitting portion between the tapered shank and the cap.

Further, in a further preferred aspect of the present invention, the tapered shank and the inner periphery of the cap are provided with
A plurality of tapered needle pins biased inward by elastic means are arranged in an annular shape.

Further, in another preferred aspect of the present invention, the rotation stopping mechanism is composed of a roller type one-way clutch arranged on the inner circumference of the tapered shank and the cap.

Further, in another preferred aspect of the present invention, the rotation stopping mechanism has a ball plunger arranged between the tapered shank and the cap, and the cap is predetermined with respect to the tapered shank. And a hole into which the ball plunger is fitted when it is rotated by an angle.

[0010]

According to the chuck of the present invention, first, the taper shank is fixed to the rotary shaft of the machine tool, and the shank of the tool is inserted from the cap side into the insertion holes of the cap and the taper shank. The shank of the tool is in a state of being inserted into the torsion coil spring arranged inside the cap and the tapered shank. Therefore, when the cap is rotated in a predetermined direction with respect to the taper shank and the torsion coil spring is wound and tightened, the intermediate portion of the torsion coil spring is reduced in diameter and the shank of the tool is clamped and fixed. In this case, even if the repulsive force of the torsion coil spring acts, the anti-rotation mechanism prevents rewinding, and the tool can be maintained in a fixed state. Further, when the tool is replaced after the machining is finished, the stopping force by the rotation stopping mechanism is released, the torsion coil spring is rewound, and the tool can be removed.

As described above, since the tool is fixed by the winding tightening force of the torsion coil spring, the tool can be tightened with a uniform force along the axial direction of the shank of the tool, and the tool can be firmly fixed. it can. Further, by increasing the spring force of the torsion coil spring, the tool can be stably held.

In a preferred embodiment of the present invention, when a plurality of tapered needle pins urged inward by elastic means are annularly arranged on the inner circumference of the tapered shank and the cap, the tapered needle pin is provided. Even if the shank diameter of the tool changes in the movable range of, the tool can be held. Further, the centering function of the tapered needle pin allows the taper needle pin to be held without eccentricity.

[0013]

1 and 2 show an embodiment of a chuck according to the present invention. As shown in FIG. 1, the chuck 11 includes a taper shank 12 and a cap 13 assembled to the taper shank 12.

The tapered shank 12 has a taper shape in which the outer periphery is tapered upward, and the inside thereof has an insertion hole 15 into which the shank 14a of the tool 14 is inserted. At the upper end portion of the insertion hole 15, there is provided a draw screw portion 15a which serves as a fixing means to a rotating shaft of a machine tool (not shown).

The cap 13 is placed on the outer periphery of the lower portion of the tapered shank 12, and a ball plunger 17 inserted inward from the peripheral wall of the cap 13 is fitted into an annular groove 16 formed in the tapered shank 12. The cap 13 is rotatably attached to the tapered shank 12. Further, when the cap 13 is strongly pulled downward, the ball plunger 17 is disengaged from the annular groove 16 and the cap 13 can be removed from the tapered shank 12.

Also, the taper shank 12 and the cap 1
A ratchet 18 is provided on the contact surface of No. 3. This ratchet 18 allows the tapered shank 12 to rotate in the direction of the arrow A in the drawing and the cap 13 to rotate in the direction of the arrow B in the drawing, but they rotate in the opposite direction. It has the effect of regulating things. Further, the cap 13 is formed with an insertion hole 19 into which the shank 14a of the tool 14 is inserted.

A needle housing 21 is substantially fixedly mounted on the inner circumference of the tapered shank 12,
Similarly, the needle housing 2 is also provided on the inner circumference of the cap 13.
2 is mounted in a substantially fixed manner. The inner walls of the needle housings 21 and 22 are tapered,
A tapered needle pin 23 is arranged via a spring 24 so as to be slidable along the inner wall in the axial direction.

Referring also to FIG. 2, the tapered needle pin 23 has a needle housing 22 (21 is the same).
Is guided by a guide groove 25 formed in the inner wall of the spring 2 and is supported so as to be able to move forward and backward as indicated by an arrow C in the drawing.
It is always urged inward by 4. Therefore, when the shank 14a of the tool 14 is pushed in, the tapered needle pin 23 is expanded according to the diameter of the shank 14a and elastically abuts on the outer periphery of the shank 14a, thereby supporting the shank 14a without eccentricity.

The end portions of the needle housings 21 and 22 facing each other project into the insertion hole 15 with a predetermined gap therebetween with the inner wall of the insertion hole 15 of the tapered shank 12. Then, the torsion coil spring 31 is wound in the left direction.
The upper end of the needle housing 21 is held by the outer circumference of the needle housing 21, and the lower end thereof is held by the outer circumference of the needle housing 22. The middle part of the torsion coil spring 31 is
The tool 14 is arranged on the outer periphery of the shank 14a with a predetermined gap therebetween.

In the figure, 32 is a recess for inserting a dedicated tool for turning the cap 13, and 33 is a seal ring.

Next, the method of using the chuck 11 will be described. First, the taper shank 12 is fixed to the rotary shaft of the machine tool via the drawing screw portion 15a. The ball plunger 17 of the cap 13 is fitted into the annular groove 16 of the taper shank 12 and assembled to the taper shank 12.

In this state, the shank 14a of the tool 14 is
When inserted into the insertion hole 19 of the cap 13 and the insertion hole 15 of the tapered shank 12, the shank 14 a is inserted into the torsion coil spring 31. Then, when a dedicated tool is inserted into the recess 32 of the cap 13 and the cap 13 is rotated relative to the tapered shank 12 in the direction B in the drawing, the torsion coil spring 31 is wound and the shank 14a of the tool 14 is tightened. Fixed.

In this case, the repulsive force is exerted by tightening the torsion coil spring 31, but the ratchet 18 prevents the cap 13 from rotating in the direction opposite to the direction B in the drawing with respect to the tapered shank 12. The torsion coil spring 31 does not rewind. Further, when the taper shank 12 is rotated in the A direction in the drawing for processing, the torsion coil spring 31 is further tightly wound by the load applied to the tool 14, so that the tool 14 can be firmly fixed and held.

Since the tool 14 is fixed by winding the torsion coil spring 31 in this manner, a uniform tightening force can be obtained along the axial direction, and a strong holding force capable of withstanding a large load can be obtained. it can. Further, in this embodiment, since the tapered needle pin 23 has a structure that elastically abuts and supports the outer periphery of the shank 14a of the tool 14, there is an advantage that it can be applied even if the outer diameter of the tool 14 changes to some extent. .

When the tool 14 is removed after the machining is finished, the cap 13 may be strongly pulled downward to remove the fitting between the ball plunger 17 and the annular groove 16.
As a result, the ratchet 18 is disengaged, so that the cap 13 can freely rotate with respect to the taper shank 12, the torsion coil spring 31 is rewound and the tightening is released, and the tool 14 can be pulled out downward.

FIG. 3 shows another embodiment of the chuck according to the present invention. It should be noted that substantially the same parts as those in the above-mentioned embodiment are designated by the same reference numerals for description. This chuck 41
Also comprises a tapered shank 12 and a cap 13 assembled to this. The cap 13 is put on the outer periphery of the lower end portion of the tapered shank 12, and the cap 1
The ball plunger 17 inserted in the No. 3 is rotatably assembled by fitting into the annular groove 16 of the tapered shank 12.

Inside the cap 13, there is arranged a sleeve 42 whose lower end is expanded in the shape of a flange. The sleeve 42 and the cap 13 are fitted with each other when the cap 13 is assembled to the tapered shank 12. It is designed to be fitted with and integrated with rotation. Further, when the cap 13 is pulled downward and removed from the tapered shank 12, the fitting in the fitting portion 43 is also disengaged, and the sleeve 42 can be freely rotated as the cap 13.

A roller type one-way clutch 44 is press-fitted and fixed to the inner circumference of the taper shank 12.
This one-way clutch 44 has a tapered shank 12
Allows the tool 14 to rotate in the direction A in the drawing, but prevents the tool 14 from rotating in the opposite direction. Similarly, a roller-type one-way clutch 45 is also press-fitted and fixed to the inner circumference of the cap 13, and this one-way clutch 45 allows the cap 13 to rotate with respect to the tool 13 in the direction B in the drawing, Rotation in the opposite direction acts to prevent it. As the roller type one-way clutches 44, 45, for example, "shell type roller clutch" (trade name, manufactured by NSK Ltd.) can be used.

The tapered shank 12 has a boss portion 46 formed in a double tubular shape inside thereof. This boss 46
The reduced diameter portion of the sleeve 42 is arranged on the inner periphery of the cap 13 so as to face the. Then, the left-handed torsion coil spring 31 is mounted with its upper end held on the outer circumference of the boss portion 46 and its lower end held on the outer circumference of the sleeve 42. The intermediate portion of the torsion coil spring 31 is arranged on the outer periphery of the shank 14a of the tool 14 with a predetermined gap therebetween.

In using the chuck 41, the taper shank 12 is attached to the rotary shaft of the machine tool, and then the shank 14a of the tool 14 is inserted into the insertion hole 15 of the tapered shank 12 through the insertion hole 19 of the cap 13. At this time, the shank 14 a is passed through the inner circumferences of the one-way clutch 45, the sleeve 42, the torsion coil spring 31, and the one-way clutch 44.

In this state, when the cap 13 is rotated relative to the tapered shank 12 in the direction B in the figure,
The torsion coil spring 31 is wound tightly, and the shank 14a of the tool 14 is fastened and fixed. In this case, the one-way clutches 44 and 45 prevent the cap 13 from rotating with respect to the taper shank 12 in the direction opposite to the direction B in the figure, so that the torsion coil spring 31 does not rewind. Further, when the taper shank 12 is rotated in the A direction in the drawing for processing, the torsion coil spring 31 is further tightly wound by the load applied to the tool 14, so that the tool 14 can be firmly fixed and held.

When the tool 14 is removed after the machining is completed, the cap 13 may be strongly pulled downward to remove the fitting between the ball plunger 17 and the annular groove 16, whereby the fitting portion 43 is fitted. Since the engagement is released, the sleeve 42 is allowed to freely rotate with respect to the cap 13, the torsion coil spring 31 is rewound and the tightening is released, and the tool 14 can be pulled out downward.

FIG. 4 shows a further embodiment of the chuck according to the present invention. It should be noted that substantially the same parts as those in the above-mentioned embodiment are designated by the same reference numerals for description. This chuck 5
1 also includes a taper shank 12 and a cap 13 assembled to the taper shank 12. The cap 13 is covered on the outer circumference of the lower end portion of the tapered shank 12, and the ball plunger 17 inserted into the cap 13 is rotatably assembled by fitting into the annular groove 16 of the tapered shank 12. In this case, the annular groove 16
Has a deeper hole 16a formed at a predetermined position on the circumference thereof. When the cap 13 is rotated with respect to the tapered shank 12, the ball plunger 17 is held at a predetermined position.
Is fitted in the hole 16a to prevent rotation.

A sleeve 52 is mounted on the inner periphery of the tapered shank 12 via a ball plunger 61 substantially integrally with the tapered shank 12. Sleeve 5
A one-way clutch 44 having an inner diameter adapted to the shank 14a of the tool 14 is press-fitted and fixed to the inner periphery of the tool 2. The one-way clutch 44 is a taper shank 12
Engages when the tool rotates relative to the tool 14 in the direction A in the drawing, and idles when it rotates in the opposite direction.

On the inner periphery of the upper portion of the sleeve 52, a right-handed spring clutch 53 has a predetermined gap between the spring clutch 53 and the tool 14, and the upper end of the spring clutch 53 is located at the sleeve 5.
It is fixed and attached to 2.

On the other hand, the sleeve 54 is arranged on the inner circumference of the cap 13, and the ball plunger 55 inserted into the cap 13 is formed in the hole 5 formed on the outer circumference of the sleeve 54.
6 and the cap 13 and the sleeve 54 are integrated. However, the above fitting can be released by loosening the screwing of the ball plunger 55.

A one-way clutch 45 is press-fitted and fixed to the inner circumference of the sleeve 54. One-way clutch 4
5 engages when the tool 14 rotates relative to the sleeve 54 in the direction B in the drawing, and idles when the tool 14 rotates in the opposite direction. In other words, when the cap 13 and the sleeve 54 are rotated relative to the tool 14 in the B direction in the drawing, they will idle.

On the inner circumference of the sleeve 54, a left-handed spring clutch 57 is attached with a predetermined gap amount between the spring clutch 57 and the tool 14 and its lower end fixed to the sleeve 54.

Opposing ends of the sleeves 52 and 54 have a predetermined gap with respect to the inner circumference of the tapered shank 12, and a left-handed torsion coil spring 31 holds the upper end of the sleeve 53 on the outer circumference of the sleeve 53. The lower end of the sleeve 54 is attached to the outer periphery of the sleeve 54. The intermediate portion of the torsion coil spring 31 is arranged on the outer periphery of the shank 14a of the tool 14 with a predetermined gap therebetween.

The spring constants of the spring clutches 53 and 57 are the same even if they are added together.
Set smaller than the spring constant of 1.

Next, the method of using the chuck 51 will be described. First, after mounting the taper shank 12 on the rotary shaft of the machine tool, the shank 14a of the tool 14 is passed through the insertion hole 19 of the cap 13 and the taper shank 12 is inserted.
It is inserted into the insertion hole 15 of. At this time, shank 14a
Is spring clutch 57, one-way clutch 4
5, the torsion coil spring 31, the one-way clutch 44, and the inner circumference of the spring clutch 53 are passed through.

In this state, when the cap 13 is rotated relative to the tapered shank 12 in the B direction in the figure,
The torsion coil spring 31 is wound tightly, and the shank 14a of the tool 14 is tightened. Then, when the cap 13 is rotated to a position where the shank 14a of the tool 14 is tightened and fixed, the ball plunger 17 is fitted into the deep hole 16a provided in the annular groove 16 to prevent the cap 14 from rotating. . In this way, the tool 14 can be fixedly held.

When the tool 14 is removed after the processing is completed, the ball plunger 55 is loosened so that the sleeve 54 can be rotated with respect to the cap 13. The sleeve 54 is rotated by the repulsive force of the twisted coil spring 31. 54
Rotates, a gap is formed between the shank 14a of the tool 14 and the torsion coil spring 31, and the tool 14 can be pulled out downward.

[0044]

As described above, according to the present invention,
Since the tool is fixed by the winding tightening force of the torsion coil spring, the tool can be tightened with a uniform force along the axial direction of the shank of the tool, and the tool can be firmly fixed.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a chuck according to the present invention.

FIG. 2 is a partially enlarged sectional view of the chuck.

FIG. 3 is a sectional view showing another embodiment of the chuck according to the present invention.

FIG. 4 is a sectional view showing still another embodiment of the chuck according to the present invention.

[Explanation of symbols]

 11, 41, 51 Chuck 12 Tapered shank 13 Cap 14 Tool 15 Insertion hole 14a Tool shank 16 Annular groove 17 Ball plunger 18 Ratchet 19 Insertion hole 21, 22 Needle housing 23 Tapered needle pin 24 Spring 25 Guide groove 31 Torsion coil spring 42 sleeve 43 fitting part 44, 45 one-way clutch 52, 54 sleeve 53, 57 spring clutch 55 ball plunger 56 hole

Claims (5)

[Claims] 1. A taper shank (12) which has a tapered outer periphery, has an insertion hole (15) for a tool (14) therein, and is detachably fixed to a rotating shaft of a machine tool, and the taper shank. The insertion hole (1) is rotatably assembled to the (12) and communicates with the insertion hole (15) inside.
A cap (13) having a taper shank (12) and the cap (1)
In the inside of 3), one end is held on the side of the taper shank (12), the other end is held on the side of the cap (13), and the intermediate portion is positioned on the outer circumference of the tool (14) inserted therein. When the cap (13) is rotated in a predetermined direction with respect to the torsion coil spring (31) and the taper shank (12) to tighten the torsion coil spring (31), the torsion coil spring (3)
1) A chuck provided with a detent mechanism for preventing rewinding, and a mechanism for relieving the torsion coil spring (31) by relieving the restraining force of the detent mechanism. 2. The chuck according to claim 1, wherein the detent mechanism comprises a ratchet (18) provided at a fitting portion between the tapered shank (12) and the cap (13). 3. A plurality of tapered needle pins (23) biased inwardly by elastic means (24) on the inner circumference of the tapered shank (12) and the cap (13).
The chuck according to claim 1, wherein the chuck is arranged in an annular shape. 4. The chuck according to claim 1, wherein the detent mechanism is a roller type one-way clutch (44, 45) arranged on the inner circumference of the tapered shank (12) and the cap (13). 5. The ball stopper (17) disposed between the taper shank (12) and the cap (13), and the cap (13) with respect to the taper shank (12). The chuck according to claim 1, which is formed with a hole into which the ball plunger (17) is inserted when the member (13) is rotated by a predetermined angle.