JPS5848005Y2 - Collection check - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a collet chuck in which a cutting tool such as a drill is fitted into a chuck body attached to the main shaft side via a collet.

Conventionally, this type of collet chuck has the configuration shown in FIG. The collet 3 is press-fitted into the tapered hole 2 using the flange 5 of the tightening nut 4 which is screwed into the threaded part 1a and comes into contact with the shoulder part 3a of the collet 3, and the collet 3 and the cutting tool are fitted into the chuck body 1. ing.

However, in the collet chuck having the above configuration, if there is even a slight shape error in the threaded portion between the tightening nut 4 and the chuck body 1 and the contact surface between the 7 flange 5 and the collet shoulder 3a, the flange of the tightening nut 4 may 5, a uniform force is not applied to the collet end face 3a, and therefore, a so-called uneven tightening condition occurs in which force is applied uniformly even to the tapered part where the collet 3 and the chuck body 1 contact, and the collet is attached to the collet. There was a drawback that the cutting tool could not be reliably fitted into the chuck body, causing the tool to become misaligned with respect to the main shaft.

In addition, in order to eliminate the above-mentioned drawbacks, it is conceivable to interpose a spacer having a spherical surface that contacts the shoulder of the collet between the collet and the tightening nut, but in this case, the collet and the spacer are in line contact with each other. As a result, wear is extremely severe, and sufficient clamping force against rotation of the collet cannot be ensured, making it undesirable for practical use.

This invention attempts to solve the above problem by interposing a first spacer and a spherical second spacer between the shoulder of the collet and the flange of the tightening nut. A collet characterized in that a uniform force is applied to the collet shoulder even if there is a shape error between the collet and the shoulder, and a uniform force is applied to the collet and the tapered part of the chuck body to enable accurate chucking. It provides a chuck.

Hereinafter, this invention will be explained in detail with reference to embodiments shown in FIG. 2 and subsequent figures.

6 is the chuck body, 7 is the collet, 8 is the tightening nut, 9
is a first spacer, and 10 is a second spacer.

The chuck body 6 has a tapered hole 11 for inserting a collet in the shaft core, and the outer peripheral surface of the small diameter side of the tapered hole 11 is made into a tapered surface 6a in the same direction as the tapered hole 11, and A tapered surface 6b is formed which is inclined opposite to the tapered surface 6a, and a threaded portion 12 is carved on the outer circumferential surface of the large diameter side of the tapered hole 11 following the tapered surface 6b.

The collet 7 has a hole 14 in its shaft core into which a cutting tool 13 such as a drill is inserted, and an axial groove 1 in its peripheral wall.
5 is set.

The outer circumferential surface of the collet 7 has a tapered surface 7a that fits into the tapered hole 11 of the chuck main body 6 from one end to the vicinity of the other end, and a tapered surface 7a that continues toward the large diameter side of the tapered surface 7a and is opposite to the tapered surface 7a. A shoulder portion 7b that is inclined in the axial direction and short in the axial direction, and a linear surface 7c that extends from the shoulder portion 7b to the tip are formed.
7c is provided with a mounting groove 7d for the snap ring 20.

The tightening nand 8 is provided with a threaded portion 16 that engages with the threaded portion 12 of the chuck body 6, and is integrally formed with a 7 flange 17 protruding inward at the tip portion spaced apart from the threaded portion 16 by a predetermined distance. are doing.

The first spacer 9 has an annular shape, and has a first tapered surface 9a that fits with the shoulder γb of the collet 7 on one side thereof, and a first tapered surface 9a on the other side with an axially short inner circumferential surface 9b in between. A second tapered surface 9c is formed which is inclined opposite to the surface 9a.

Similarly, the inclination angle α1 between the first tapered surface 9a and the second tapered surface 9c. It is preferable that α2 is the same angle, and the angle α
1. α2 is preferably about 30.

The second spacer 10 also has an annular shape, and has a spherical surface 10a that comes into contact with the second tapered surface 9c of the first spacer 9 on one side thereof.

In addition, the chuck body 6° tightening nut 8 and the second spacer 10 are made of SK3.

Collet 7 is made of SCM21, first spacer 9 is 84
Made of 5C and all quenched.

Next, the chucking action using each of the above members will be explained.

The chuck body 6 is fitted into the mounting taper hole 8a of the main shaft 18, and is fixed by pressing the tapered surface 6b of the chuck body 6 with the inward flange 19a of the tightening nut 19.

The collet 7 is fitted into the tapered hole 11 of the chuck body 6 with its tapered surface 7a adapted, and the cutting tool 13 is fitted into the hole 14 of the collet 7, and the threaded portion 12 of the chuck body 6 is fitted. Screw the threaded portion 16 of the tightening nut 8 into the 7 flange 17 of the tightening nut 8 and the shoulder portion 7 of the collet 7.
a first spacer 9 and a second spacer 10 between the collet γ and the first tapered surface 9 of the first spacer 9 on the shoulder 7b of the collet γ.
A is brought into contact with the second tapered surface 9c of the first spacer 9, and the spherical surface 10a of the second spacer 10 is brought into contact with and interposed therebetween.

Unscrew the threaded part 12 of the chuck body 6 and the threaded part 16 of the tightening nut 8, and tighten the collet 7 with the snap ring 20.
With the cutting tool 13 pulled out, the cutting tool 13 is replaced.

At this time, the cutting tool 13 is in a state where it can slide into the hole 14 of the collet 7, and the collet 7 is in a slidable state into the tapered hole 11 of the chuck body 6, and from this state, the threaded parts 12 and 16 are tightened. I do.

Depending on the screw tightening, the flange 1γ has a second spacer 10,
The shoulder portion 7b of the collet T is pressed through the first spacer 9, and the collet 7 is press-fitted into the tapered hole 11 of the chuck body 6.

At this time, when the spherical surface 10a of the second spacer 100 comes into contact with the second tapered surface 9c of the first spacer 9, it makes line contact and presses the first spacer 9, and the first spacer 9 moves in the radial direction to shoulder the collet shoulder. It settles at a position where a uniform force is applied to the portion 7b.

Therefore, in order to apply a uniform force to the collet shoulder 7b and accurately press the collet 7 in the direction of the axial force, a uniform force is applied to the tapered hole 11 of the chuck body 6 that comes into contact with the collet 7, and the collet 7 and the collet 7 To accurately chuck the cutting tool 13 inside.

As is clear from the above description, according to the collet chuck according to the invention, a first spacer and a second spacer having a spherical surface are interposed between the collet and the flange of the tightening nut, and the second spacer makes line contact with the flange of the tightening nut. Since the first spacer is pressed by a wedge and has a wedge effect, the collet is tightened with a uniform force without any unilateral lines due to the wedge effect, which has the effect of accurately and reliably chucking the collet and cutting tool. be.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional collet chuck, Fig. 2 is a sectional view showing an embodiment of this invention, Fig. 3 is a sectional view of the collet, Fig. 4 is a sectional view of the first spacer, and Fig. 5 is a sectional view showing a conventional collet chuck. The figure is a sectional view of the second spacer. 6... Chuck body, 7... Collet, 7b...
Shoulder part, 8... Tightening nut, 9... First spacer, 9
a...first tapered surface, 9c...second tapered surface, 10
...Second spacer, 10a...Spherical surface, 11...Tapered hole,...Threaded portion, 13...Cutting tool. 12.16

Claims (1)

[Claims for Utility Model Registration] A chuck body having a tapered hole for inserting a collet and having a threaded portion on the outer circumferential surface of the large-diameter side; a collet having a shoulder portion inclined opposite to its outer circumferential tapered surface on its side; a first tapered surface matching the shoulder portion; and a second tapered surface inclined opposite to the first tapered surface on both sides. a second spacer having a spherical surface that abuts the second tapered surface; and a tightening device having an inward flange that abuts the second spacer and has a threaded portion that threads into the threaded portion of the chuck body. - A first spacer and a second spacer are interposed between the shoulder of the collet and the inward flange of the tightening nut, so that the tightening nut chucks the collet and the cutting tool inserted into the collet. A collet chuck characterized by being fitted into the main body.