JP2001246508A - Two-surface constraint tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a gap on a contact surface of an end face of a main spindle and to prevent the end face of the main spindle from being damaged due to friction between collars and the end face of the main spindle by suppressing friction heating between the collar and the end face due to minute vibration in cutting to prevent a tool from elongating. SOLUTION: In this two-surface constraint tool, a tapered part of a tapered shank 3 inserted into a tapered hole 2 in the main spindle 1 is constrained onto an inner circumferential surface of the tapered hole 2 and an end face 5a of a flange part of the tapered shank 3 is constrained onto an end face 6 of the main spindle via the collars 7, 8 with the collars 7, 8 put between the end face 5a of the flange part and the end face 6 of the main spindle. Materials 9, 10 with small coefficient of friction used as sliding surfaces are provided on surfaces of the collars 7, 8 standing opposite to the end face of the main spindle 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool mounted on a spindle of a machine tool such as a machining center, and more particularly, to a two-sided tool in which a tool is constrained to a spindle by two surfaces of a taper portion and a flange portion of a taper shank. Related to constraint tools.

[0002]

2. Description of the Related Art Conventionally, a system shown in FIG. 3 is known as a system for restraining a taper shank on two surfaces. FIG. 3 shows what is called an end face color adjustment method, in which 30 is a main shaft, and 33 is a taper shank.

A tapered shank 33 is inserted into a tapered hole 31 of the spindle 30, and a spindle end face 36 of the spindle 30 and a flange end face 3 of a flange portion 34 of the tapered shank 33.
The collar 35 is mounted so as to be sandwiched between the collar 35 and the base member 7. According to this method, the taper portion of the taper shank 33 is constrained by the inner peripheral surface of the taper hole 31, and the flange portion 34 is constrained by the main shaft end surface 36 of the main shaft 30 integrally with the collar 35. The rigidity can be increased. A magnet 38 is embedded in the collar 35 and is fixed to the flange end face 37 by magnetic force.

[0004]

However, conventionally, the collar 35 has two drawbacks because it is made of steel.

One of the reasons is that in high-speed cutting with a large amount of tool protrusion, a friction coefficient between a contact portion between a collar 35 made of steel and a spindle end surface 36 is high, so that friction between the collar 35 and the collar 35 is caused by minute vibration. The spindle end face 36 generates heat due to the sliding, and the heat is transmitted from the collar 35 to the tool 32. As a result, the tool 32 is extended, and the spindle end face 3
A gap is generated in the contact portion of No. 6, thereby losing the effect of the two-face constraint, lowering the support rigidity of the tool 32, inducing vibration, and machining the surface roughness and hole diameter required for drilling and machining a workpiece. However, there is a problem that the processing accuracy such as the depth dimension of the hole cannot be maintained.

There is another problem that the collar 35 and the spindle end face 36 are rubbed and the spindle end face 36 is damaged.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problems of the prior art, and to suppress frictional heat generation due to minute vibration between a collar and a spindle end face during high-speed cutting with a large amount of tool protrusion, thereby preventing tool elongation due to heat. In order to prevent the occurrence of a gap in the contact portion of the spindle end face, and obtain the machining accuracy of the required surface roughness, hole diameter, hole depth and the like required for drilling and surface machining of a workpiece while maintaining the effect of two-face constraint. Another object of the present invention is to provide a two-surface restraint tool which does not damage the spindle end surface even when the collar and the spindle end surface rub.

[0008]

In order to achieve the above-mentioned object, the present invention provides a tapered shank inserted into a tapered hole of a main shaft on an inner peripheral surface of the tapered hole, and a flange of the tapered shank. In a two-surface restraint tool in which a collar is interposed between the end face of the spindle and the end face of the spindle, and the end face of the flange is restrained by the end face of the spindle via the collar,
A material for a sliding surface is provided on a surface of the collar facing a spindle end surface.

According to the present invention, a material for a sliding surface having a smaller coefficient of friction than a spindle end surface is used for a surface of the collar in contact with the spindle end surface facing the spindle end surface, so that the collar and the spindle end surface at the time of cutting are formed. Reduces frictional heat generated by micro vibrations
Elongation of the tool due to heat is prevented, and a high support rigidity of the tool can be maintained by preventing a gap from being formed at a contact portion of the spindle end face, and the spindle end face is not damaged even if the collar and the spindle end face rub.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a cross-sectional view of a two-sided restraint tool according to an embodiment of the present invention. FIG. 2 shows an AA cross section of FIG.

As examples, sliding surface materials 9 and 10 are made of polytetrafluoroethylene-based turquite (a product handled by Captain Industries Co., Ltd.), and collars 7 and 8 have sliding surfaces on the main shaft 1 side. Materials 9 and 10 are attached to the same surface shape with a dedicated adhesive EX bond (registered trademark). The sliding surface materials 9 and 10 need not be turquite, and the attachment may be other bonding than bonding. The collars 7 and 8 are obtained by symmetrically dividing the ring-shaped collar into halves and have substantially the same outer diameter and inner diameter as the flange end face 5a. A part is formed, and the convex part is adapted to engage with a groove formed on the flange end face 5 a of the flange part 5 of the tapered shank 3. Further, the magnets 11 are embedded in the flange end surfaces 5a of the collars 7 and 8 so as to be fixed to the flange end surfaces 5a.

A drawbar connected to a clamping force generating mechanism and a collet at the end thereof (both not shown) are provided inside the main shaft. The collet grasps a pull stud attached to the tip of the taper shank 3. The taper shank 3 is pulled in by a strong clamping force.

The tapered portion of the tapered shank 3 is constrained by the inner peripheral surface of the tapered hole 2 of the spindle 1. The flange portion 5 is connected to the spindle end face 6 via collars 7 and 8 to which sliding surface materials 9 and 10 are adhered. Since the tool 4 is constrained, high support rigidity can be obtained.
In addition, even if vibration friction occurs between the spindle end face 6 and the sliding surface materials 9 and 10 during cutting, the sliding surface materials 9 and 10 have a small coefficient of friction, approximately 1/10 that of steel, so that heat generation is suppressed. Thus, the extension of the tool 4 due to heat can be prevented, and the spindle end face 6 is not damaged by friction.

[0014]

As is apparent from the above description, according to the present invention, by using a material having a smaller friction coefficient than the spindle end face for the collar in contact with the spindle end face, the collar can be used at high speed cutting with a large amount of tool protrusion. The friction heat generated by micro vibrations between the shaft and the spindle end surface is reliably suppressed, the tool is prevented from elongating due to the heat, and no gap is created at the contact portion of the spindle end surface, and the effect of the two-face constraint is maintained while drilling or machining the workpiece. The required processing accuracy such as required surface roughness, hole diameter, hole depth, etc. can be obtained, and even if the collar and the spindle end face rub, the spindle end face will not be damaged.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing close contact between a tool portion and a spindle end face according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG. 1;

FIG. 3 is a cross-sectional view of a conventional two-surface constraint tool.

[Explanation of symbols]

 Reference Signs List 1 spindle 2 tapered hole 3 taper shank 4 tool 5 flange 5a flange end face 6 spindle end face 7,8 collar 9,10 material for sliding surface

Claims (1)

[Claims] 1. A taper portion of a taper shank inserted into a taper hole of a main shaft is provided with a collar interposed between an inner peripheral surface of the taper hole and a flange end surface of the taper shank and a main shaft end surface. A two-sided restraint tool, wherein a material for a sliding surface is provided on a surface of the collar facing the main shaft end surface via the collar, the surface facing the main shaft end surface of the collar.