JPH0811324B2 - Tool holder fixing device for machine tools - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A rotary tool for machining is detachably held by a tool holder, and a pull stud of the tool holder is placed in a collet integrally attached to the tip of a drawing bar with a disc spring interposed in the middle. When the drawing bar retracts by being inserted, the collet holding the pull stud is pulled back by the disc spring and retracts, and the slope of the tool holder taper shank comes into close contact with the slope of the tool holder taper shank The holder is fixed.

In addition, the machine tools are generally required to be improved in machining accuracy and efficiency as the cutting level is improved.

[0004]

[Problems to be solved by the invention] The cutting level is improved,
When the processing accuracy and the processing efficiency are required to be improved, the tool holder must be made highly rigid and firmly fixed to the spindle.

However, in the prior art described above, the taper hole of the spindle and the taper shank of the tool holder are in close contact, but the flat surface outside the taper hole of the spindle and the flat surface of the collar of the tool holder are in close contact. I haven't.

It is obvious that the rigidity value of the tool holder is significantly increased by bringing the taper hole of the spindle and the taper shank of the tool holder into close contact with their respective flat surfaces. It is extremely difficult to make a holder.

[0007]

A stepped sleeve with a collar is fitted to a step formed on the outer periphery of an opening on the taper hole side of a spindle, and a groove is provided on a fitting surface of the stepped sleeve with the spindle. , The stepped sleeve is expanded in the radial direction and can be moved in the axial direction.The spindle is provided with a through hole for pressure-feeding the high-pressure fluid to communicate with the concave groove and maintain a slight clearance with the outer peripheral surface of the stepped sleeve. ,
In addition, a ring-shaped holding member provided with a concave portion surrounding the flange of the stepped sleeve is fixed to the horizontal surface of the step portion of the spindle, and a concave groove is provided concentrically on the bottom surface of the concave portion, and the pushing elastic member having an arcuate cross section is formed. The ring is closely fitted to the groove so that a closed space is formed with the concave surface facing the groove, and the convex surface is pressed against one surface of the flange of the stepped sleeve, and the space is closed. A through hole for sending high-pressure fluid to the spindle and the holding member is provided in communication with the spindle and the holding member, and a concentric circular groove is formed on the horizontal surface of the stepped portion of the spindle facing the brim of the stepped sleeve, and the extrusion with an arcuate section is formed. The elastic ring for use in the groove is tightly fitted so that a closed space is formed with the concave surface facing the groove, and the convex surface is in pressure contact with the other surface of the flange of the stepped sleeve, A passage for pumping high-pressure fluid to the void Is provided on the spindle and a nozzle capable of advancing and retracting in contact with each through hole is provided.Furthermore, the flange diameter of the tool holder is widened, and the flat surface at the lower end of the stepped sleeve is brought into close contact with the flat surface. The rotary tool is firmly fixed by increasing the rigidity of the tool holder by tightly adhering the inclined surface of the spindle taper hole, the inclined surface of the tool holder taper shank, and the flat surface of the tool holder flange and the flat surface of the stepped sleeve. However, the purpose is to improve the processing accuracy and processing efficiency.

[0008]

When the spindle is positioned in the rotation direction and stopped, and then the high pressure fluid is pressure-fed from the nozzle communicating with the through hole provided in the spindle to the concave groove provided in the spindle fitting surface of the stepped sleeve, the stepped sleeve is removed. It expands in the radial direction and lubricates the fitting surface with the spindle, enabling axial movement.

High-pressure fluid is pumped into the recess of the elastic ring for pushing, and the stepped sleeve is pushed toward the spindle side (upward). Then insert the tool holder into the spindle.

Next, when the drawing bar is retracted, the disc holder integrated with the drawing bar pulls the tool holder, and the taper shank of the tool holder comes into close contact with the taper hole of the spindle.

Next, when the high-pressure fluid is pressure-fed to the cavity on the side of the elastic ring for extrusion, the elastic ring for extrusion expands to seal the cavity and press the flange of the stepped sleeve, The flat surface on the lower end side of the tool sticks closely to the flat surface of the collar of the tool holder.

Next, when the pressure-feeding of the high-pressure fluid to the concave groove provided on the surface of the stepped sleeve fitted to the spindle is stopped, the stepped sleeve is fixed to the stepped portion of the spindle.

After stopping the pressure feeding of the high-pressure fluid to each of the through holes, the nozzle that comes into contact with each of the through holes retracts and becomes non-contact, so that the spindle can rotate.

[0014]

EXAMPLE A disc spring 4 in which a pull stud 1a of a tool holder 1 for removably holding a rotary tool for machining is attached integrally to a lower end of a drawing bar 3 slidably fitted in a spindle 2. Further, the collet 5 integrally attached to the above is detachably gripped, the drawing bar 3 is slidable by advancing and retracting the cylinder 15, and the pull stud 1a is gripped by the collet 5 as the drawing bar 3 retreats. In the tool holder fixing device in which the holder 1 rises and its tapered shank 1b is in close contact with the tapered hole 2a provided in the lower portion of the spindle 2, the stepped portion 2b is formed on the outer periphery of the opening of the spindle on the tapered hole 2a side. The stepped sleeve 6 having the collar 6a is fitted to the stepped portion 2b in a shrink-fitted state, and the concave groove 6b is provided on the fitting surface, and The hole 7 for pumping high-pressure fluid to the groove 6b drilling axially into the spindle 2.

A slight clearance is maintained with the outer peripheral surface of the stepped sleeve 6, and the collar 6 of the stepped sleeve 6 is held.
A ring-shaped holding member 8 having a concave portion 8a surrounding a is fixed to the step horizontal surface 2c of the spintor, and a concave groove 8b is concentrically provided on the bottom surface of the concave portion 8a.

The pushing elastic ring 9 having an arcuate cross section is formed in the concave groove 8b so that a closed space 10 is formed with the concave surface facing the concave groove 8b, and the convex surface is a stepped sleeve. The spindle 2 has a through hole 11 which is tightly fitted to one surface of the collar 6a so as to be in pressure contact therewith, and through which a high-pressure fluid is pumped to the cavity 10.
And it perforates by communicating with the holding member 8.

A concave groove 2d is provided concentrically on the stepped horizontal surface 2c of the spindle so as to face the collar 6a of the stepped sleeve, and an elastic ring 12 for extrusion having an arcuate cross section is formed into the concave groove 2a.
a closed space 1 with its concave surface facing the groove 2d.
3 is formed, and the convex surface of the stepped sleeve is tightly fitted so as to be in pressure contact with the other surface of the collar 6a of the stepped sleeve, and the spindle 2 is provided with a through hole 14 for pumping the high-pressure fluid to the cavity 13.

The tool holder 1 has its flange 1c formed to have a wide diameter, the flat surface of the lower end of the stepped sleeve 6 is brought into close contact with the flat surface of the flange 1c, and the inclined surface of the taper hole 2a of the spindle is tapered to the tool holder. It is closely attached to the shank 1b.

When the tool is changed, the spindle is controlled and stopped at a predetermined rotation position (orientation), and the high pressure fluid is pressure-fed from the movable nozzles A, B and C which come into contact with the respective through holes at the stop position. .

[0020]

As the stepped sleeve 6 is movable and is moved in the axial direction of the spindle 2 by the elastic ring 9 for pushing, the drawing bar 3 is retracted and the inclined surface of the taper shank 1b of the tool holder and the spindle. The tapered surface of the taper hole 2a comes into close contact, and the flat surface of the flange 1c of the tool holder and the flat surface of the stepped sleeve come into close contact with each other by the elastic ring 12 for pushing, so that the tool holder 1 holding the rotary tool becomes highly rigid and robust. It is fixed to the spindle, improving the machining accuracy and the machining efficiency.

Further, it is possible to eliminate the difficulty of manufacturing the taper shank of the tool holder and the flat surface of the wide-diameter flange so as to be in close contact with the taper hole of the spindle and the flat surface at the lower end thereof. It

[Brief description of drawings]

FIG. 1 is a partially cutaway vertical sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of a notch of the main part.

[Explanation of symbols]

 1 Tool Holder 1c Collar 2 Spindle 2b Step Horizontal Surface 6 Stepped Sleeve 6a Collar 2d 6b 8b Recessed Groove 7 11 14 Through Hole 8 Holding Member 8a Recess 9 Elastic Ring for Pushing 10 13 Space 12 Elastic Ring for Pushing A B C nozzle

Claims (1)

[Claims] 1. A stepped sleeve having a collar is fitted to a stepped portion provided by cutting out an outer periphery of an opening portion on the taper hole side of a spindle, and a concave groove is provided on a fitting surface of the stepped sleeve with the spindle. The spindle is provided with a ring-shaped holding member having a through hole which communicates with the groove and which is formed in the spindle to maintain a slight clearance from the outer peripheral surface of the stepped sleeve and which has a recess surrounding the flange of the stepped sleeve. The concave groove is formed concentrically on the bottom surface of the concave portion while being fixed to the horizontal surface of the stepped portion, and the elastic ring for pushing in which the cross section is arcuate is made to face the concave groove, and the concave surface is opposed to the concave groove. Of the stepped sleeve on the stepped horizontal surface of the spindle by punching through the holding member and the spindle, a through hole communicating with the cavity formed between the concave surface and the concave groove by press-fitting to the flange of the spindle. When Concentric concave grooves are provided facing each other, an elastic ring for extrusion having an arcuate cross section is fitted into the concave groove, the concave surface of the elastic ring is opposed to the concave groove, and the convex surface of the elastic ring is pressed against the flange of the stepped sleeve for close fitting. , A through hole that communicates with the void formed between the concave surface and the concave groove is drilled in the spindle, and the flat surface at the lower end of the stepped sleeve is closely attached to the flange of the tool holder so that it can be separated from and into each through hole. A tool holder fixing device in a machine tool that is provided with a nozzle that can be moved in and out.