JPH0985562A - Tool holder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool holder capable of reducing vibration of l a tool. SOLUTION: A tool is inserted through an annular elastic body 4, the root is inserted into a collet 102, a bolt 104 is fastened, and the tool is fixed. The diameter of the annular elastic body 4 is contracted by fastening a fastening nut 3, and the annular elastic body 4 is made to be brought in pressure-contact with the outer periphery of the tool. When a tool holder is fixed to a main spindle of a machine tool and cutting is performed by rotating the main spindle in this state, even if oscillation is generated on the tip after the tip of the tool is oscillated, the oscillation of the tool is absorbed by the annular elastic body 4 and restrained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool holder for detachably fixing a tool to a spindle of a machine tool.

[0002]

2. Description of the Related Art In order to detachably fix a tool such as an end mill or a drill to a spindle of a machine tool, for example, a tool holder as shown in FIG. 11 is used. This tool holder includes a holder body 101, a collet 102, and a connecting body 10.
3, a bolt 104, and a locking screw 105.

The left side of the holder body 101 has a shank 11
1 and has a screw hole 1 at the center of this shank 111.
12 are formed. If a pull stud (not shown) is screwed into this screw hole 112, the shank 111 is fitted to the spindle side of the machine tool, and the pull stud is pulled, this tool holder is fixed to the spindle of the machine tool. To be done.

A cylinder 113 is formed on the right side of the holder body 101, and a tapered collet insertion hole 114 is formed in the center of the cylinder 113. This collet insertion hole 1
14 and the screw hole 112 of the shank 111 are through holes 115.
Through.

As shown in FIG. 12, the collet 102 has a tapered tightening portion 102a and a tool insertion hole 11 in the center.
6 and each radial slit 117. A connecting body 103 is connected to one end of the collet 102.

The collet 102 and the connecting body 103 are inserted into the collet insertion hole 114, and the bolt 104 is connected to the connecting body 1.
It is screwed to 03. The locking screw 105 is screwed into the screw hole 118 of the collet body 101.

Here, the tool insertion hole 11 of the collet 102
When the tool is inserted into 6 and the bolt 104 is tightened, the collet 102 moves to the left and the tightening portion 102a
Is deformed, and the tool insertion hole 116 is reduced in diameter. This allows
The tool is tightened and fixed.

After that, the holder for the tool is fixed to the spindle of the machine tool, and the spindle is rotated to perform cutting with the tool.

[0009]

However, when a very long tool is fixed by the above-mentioned conventional tool holder, the tool vibrates due to the rotation and cutting of the tool and the tip thereof swings. That caused a problem. Therefore, no matter how high the precision of the tool holder or the tool is, the working precision is lowered.

Therefore, an object of the present invention is to provide a tool holder capable of reducing the vibration of the tool.

[0011]

In order to solve the above-mentioned problems, the present invention is a tool holder fixed to a spindle of a machine tool for removably tightening the tool. It has an elastic member that is pressed into contact with.

That is, not only the tool is tightened and fixed, but also the elastic member is pressed against the tool. This elastic member absorbs the vibration of the tool, suppresses the expansion and resonance of the vibration of the tool, and reduces the vibration of the tool.

When the base portion of the tool is tightened and fixed, the cutting edge of the tool is likely to vibrate. Therefore, if an elastic member is pressed against the portion near the cutting edge, the vibration of the tool can be reduced well. it can.

Further, as the elastic member, an annular member through which the tool is passed may be applied, the annular elastic member may be tightened to reduce the diameter, and the annular elastic member may be pressed against the tool.
In this case, if the vibration is in the direction orthogonal to the axis of the tool, the vibration in any direction can be favorably reduced. Alternatively, the same effect can be expected by disposing a plurality of elastic members at a plurality of locations on the outer circumference of the tool and pressing these elastic members against the outer circumference of the tool.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 and FIG. 2 show a first embodiment in which the tool holder of the present invention is embodied. As shown in these drawings, the tool holder includes a holder body 1, a head 2 screwed into the right end of the holder body 1, a tightening nut 3 screwed into the right end of the head 2, and an annular elastic body 4. Is equipped with. The holder main body 1 incorporates the collet 102, the connecting body 103, the bolt 104, and the locking screw 105, like the conventional one shown in FIG.

The annular elastic body 4 is processed into a shape as shown in FIG. Further, the material of the annular elastic body 4 may be any material as long as it has appropriate rigidity and elasticity for pressing a tool and absorbing vibration, and for example, synthetic rubber, synthetic resin, wood, etc. is there.

A pair of tapered holes 3a, 2a facing each other are formed in the inside of the tightening nut 3 and the right end of the head 2, and the annular elastic body 4 is fitted into these tapered holes 3a, 2a. I'm out. When the tightening nut 3 is rotated and tightened, the tapered holes 3a and 2a come close to each other, and the annular elastic body 4 is crushed and deformed from both sides.
Is reduced in diameter.

Now, in such a structure, the tool is passed through the annular elastic body 4, the root thereof is inserted into the collet 102, and the bolt 104 is tightened to fix the tool.
Then, by tightening the tightening nut 3, the annular elastic body 4
Is contracted, and the annular elastic body 4 is pressed against the outer circumference of the tool.

In this state, when the tool holder is fixed to the spindle of the machine tool and the spindle is rotated to perform cutting, even if the tip of the tool shakes and the tool vibrates, this tool The vibration of is absorbed and suppressed by the annular elastic body 4.

Here, since the annular elastic body 4 is arranged between the base of the tool and the cutting edge, the annular elastic body 4 absorbs the vibration generated on the side of the cutting edge of the tool well. Also,
Since the ring-shaped elastic body 4 is ring-shaped, it can absorb the vibration in any direction orthogonal to the axis of the tool.

FIG. 4 shows a second embodiment in which the tool holder of the present invention is implemented. In this embodiment, FIG.
Also, instead of the tightening nut 3 and the annular elastic body 4 in the tool holder shown in FIG. 2, a tightening nut 5 and an O-ring 6 are applied.

The tightening nut 5 has an annular end portion 5a inside thereof, and the O-ring 6 abuts on the annular end portion 5a. When the tightening nut 5 is tightened, the O-ring 6 moves along the inner wall of the tapered hole 2a of the head 2 by the annular end portion 5a of the tightening nut 5, and the O-ring 6 is deformed and compressed. Diameter. As a result, the O-ring 6 is pressed against the outer circumference of the tool, and the vibration of the tool is absorbed by the O-ring 6.

FIG. 5 schematically shows a third embodiment in which the tool holder of the present invention is implemented. In this tool holder, a through hole 12 is formed in the holder body 11, and a tapered collet insertion hole 12a is formed on the right side of the through hole 12. The collet 13 is inserted into the collet insertion hole 12a, and the head 14 is screwed into the right end of the holder body 11.

The collet 13 has a tapered first tightening portion 13a, a tapered second tightening portion 13b, an annular groove 15, and a tool insertion hole 16. Further, the collet 13 has a plurality of slits 17 as shown in FIG. 6 and is divided into a plurality of radial portions 18. A plurality of elastic pieces 19 slightly protruding inside the tool insertion hole 16 are fixed to the ends of the radial portions 18.

The head portion 14 is composed of an inner peripheral annular body 21 and an outer peripheral annular body 22, and a bearing 23 is interposed between these annular bodies 21 and 22. The inner annular body 21 has a tapered hole 21a and an annular shoulder 21b. The shoulder 21b fits in the annular groove 15 of the collet 13 and locks the head 14 and the collet 13 with each other. The outer peripheral annular body 22 is screwed into the right end of the holder body 11.

In such a structure, when the tool 24 is inserted into the tool insertion hole 16 of the collet 13 and the outer peripheral annular body 22 of the head 14 is rotated and tightened, the first tightening portion 13a of the collet 13 is held by the holder. The inner wall of the collet insertion hole 12a of the main body 11 is contacted and deformed, and one end of the tool 24 is tightened and fixed. At the same time, the second tightening portion 13b of the collet 13 comes into contact with the inner wall of the hole 21a of the inner peripheral annular body 21 of the head portion 14 and is deformed, so that each elastic piece 19 causes the tool 2
It is pressed into contact with the portion of No. 4 near the cutting edge. This allows the tool 2
4 can be securely fixed, and the vibration of the tool 24 can be suppressed.

FIGS. 7A and 7B show a modification of the collet in the tool holder shown in FIG. In this collet 25, every other radial portion 26 has a plurality of holes 2
6a is formed, and a plurality of elastic pieces 27 are inserted and fixed in these holes 26a. The ends of these elastic pieces 27 are
It slightly projects inside the tool insertion hole 28 of the collet 25.

In the case of this collet 25, each radial portion 2
The one of 6 which does not have each elastic piece 27 directly clamps the tool to securely fix the tool. Further, in the radial portions 26 having the elastic pieces 27, the elastic pieces 27 are pressed against the tool, so that the vibration of the tool is suppressed.

FIGS. 8A and 8B show another modification of the collet in the tool holder shown in FIG. In this collet 31, a strip-shaped elastic piece 34 is provided every other radial portion 32, and these elastic pieces 34 are attached to the collet 31.
It slightly projects inside the tool insertion hole 35.

Also in the case of this collet 31, a tool without the elastic piece 34 among the radial parts 32 securely fixes the tool, and a piece with the elastic piece 34 suppresses the vibration of the tool.

FIG. 9 schematically shows a fourth embodiment in which the tool holder of the present invention is implemented. This tool holder includes a holder body 36, a machine screw 37, an annular elastic body 38,
And an O-ring 39.

A tool insertion hole 41 is formed in the holder body 36. The machine screw 37 is screwed into the screw hole 36a on the side wall of the holder body 36.

The annular elastic body 38 is fixed to the right end of the tool insertion hole 41 of the holder body 36. O-ring 3
9 is fixed to a portion of the tool insertion hole 41 deeper than the annular elastic body 38.

The inner diameters of the annular elastic body 38 and the O-ring 39 are smaller than the outer diameter of the tool 42. Therefore, when the tool 42 is inserted into the tool insertion hole 41, the annular elastic body 38 and the O-ring 39 are pressed against the tool 42 and suppress the vibration of the tool 42. Further, the machine screw 37 is tightened to securely fix the tool 42.

Although the annular elastic body 38 and the O-ring 39 are used here, the vibration of the tool 42 can be suppressed by using only one of them. Alternatively, the annular elastic body 38 and the O-ring 39 may be added.

FIG. 10 schematically shows a fifth embodiment in which the tool holder of the present invention is implemented. The tool holder is for fixing the tool 43 having the tapered portion 43a. The holder main body 44 is formed with a tapered tool insertion hole 45, and the tool insertion hole 45 is inserted into the tool insertion hole 45.
3 is inserted and the left end of this tool 43 is pulled to fix this tool 43.

An annular elastic body 46 is fixed to the right end of the tool insertion hole 45 of the holder main body 44, and an O-ring 47 is fixed to a portion deeper than this. The annular elastic body 46 and the O-ring 47 slightly project inside the tool insertion hole 45.

Therefore, when the tool 43 is inserted into the tool insertion hole 45 and the left end of the tool 43 is pulled, the tool 4
The tapered portion 43a of No. 3 is pressed against the annular elastic body 46 and the O-ring 47 to suppress the vibration of the tool 43. Further, the tapered portion 43a of the tool 43 has a tool insertion hole 45
Since the inner peripheral surface of the tool also directly contacts, the tool 43 is securely fixed.

Even if only one of the annular elastic body 46 and the O-ring 47 is added, or these are additionally installed,
Vibration of the tool 43 can be suppressed.

[0041]

As described above, according to the tool holder of the present invention, not only the tool is tightened and fixed but also the elastic member is pressed against the tool, so that the vibration of the tool is absorbed and It is possible to suppress the expansion and resonance of the vibration of the tool and reduce the vibration of the tool.

[Brief description of drawings]

FIG. 1 is an exploded side view showing a first embodiment in which a tool holder of the present invention is implemented.

FIG. 2 is a cross-sectional view showing the tool holder of FIG.

FIG. 3 is a perspective view showing an annular elastic body in the tool holder of FIG.

FIG. 4 is a side view partially showing a second embodiment in which the tool holder of the present invention is implemented.

FIG. 5 is a sectional view schematically showing a third embodiment in which the tool holder of the present invention is implemented.

6 is a front view showing a collet in the tool holder of FIG.

7 (a) and 7 (b) are a sectional view and a front view showing a modified example of the collet in the tool holder of FIG.

8A and 8B are a sectional view and a front view showing another modified example of the collet in the tool holder shown in FIG.

FIG. 9 is a sectional view schematically showing a fourth embodiment in which the tool holder of the present invention is implemented.

FIG. 10 is a sectional view schematically showing a fifth embodiment in which the tool holder of the present invention is implemented.

FIG. 11 is a sectional view showing a conventional tool holder.

12 is a perspective view showing a collet in the tool holder shown in FIG. 11. FIG.

[Explanation of symbols]

 1, 11, 36, 44 Holder body 2, 14 Head 3, 5 Tightening nut 4, 38, 46 Annular elastic body 6, 39, 47 O-ring 13, 25, 31, 102 Collet 19, 27, 34 Elastic piece 103 Connected body 104 Bolt 105 Locking screw

Claims (4)

[Claims] 1. A tool holder that is fixed to a main shaft of a machine tool and removably tightens and fixes the tool, the tool holder including an elastic member that is in pressure contact with the tightened and fixed tool. 2. The elastic member presses against another portion closer to the cutting edge of the tool than the portion of the tool clamped.
Tool holder described in. 3. The elastic member has an annular shape through which a tool is passed,
The tool holder according to claim 1, which is pressed against the outer circumference of the tool. 4. The tool holder according to claim 1, wherein a plurality of elastic members are arranged at a plurality of locations on the outer circumference of the tool, and the elastic members are pressed against the outer circumference of the tool.