KR20170142723A - Elastically supported tool holder for grinding tools - Google Patents

Abstract

The present invention relates to a grinding tool holder being elastically supported which is mounted on an arbor of a machine tool, such as a numerical control machine tool or a machining center, for receiving a rotational force and which is configured to insert and fix a grinding brush for grinding a material to be ground so as to be rotatably ground. To this end, the present invention includes: a cylindrical rotating sleeve inserted into an arbor of a machine tool to receive a rotational force, and having a lower end portion being opened; and a suspension assembly which is accommodated and coupled to be freely movable vertically in a cylindrical space inside the rotating sleeve, and which is elastically supported by an upper spring and a lower spring that are elastically supported by upper and lower portions thereof, respectively, and which is configured to rotate by receiving the rotational force from the rotating sleeve.

Description

[0001] ELASTICALLY SUPPORTED TOOL HOLDER FOR GRINDING TOOLS [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an abrasive tool holder, which is elastically supported, and more particularly to an abrasive tool holder which is mounted on a machine tool arbor such as a numerical control or a machining center, To a tool holder.

In the conventional polishing tool holder, when the worker sets the working height, the lower polishing surface of the polishing tool / polishing brush comes into close contact with the surface of the abrasive to be polished to perform the polishing work. As the polishing operation progresses, the polishing surface is gradually worn down and gradually moves away from the surface of the object to be polished. Accordingly, in order to bring the polishing surface of the polishing brush into close contact with the surface of the object to be polished, it is necessary to correct the polishing tool holder by the worn depth (height). However, There is a difficulty that calibration can not be done. As a result, the abrasive roughness of the surface of the abrasive to be polished becomes inhomogeneous in accordance with the abrasion state of the abrading surface of the abrasive brush, and as a result, the quality of the product is deteriorated.

In order to solve such a problem, there is known a method of inserting a spring into an upper portion of an abrasive tool holder so that a constant pressure is applied to a subject to be polished when a lower abrasive surface of the abrasive brush is polished in a compression direction (pressing direction) , This method has a disadvantage in that it is applied only to a compression polishing operation.

As another improvement method, a pressure sensor may be installed on the arbor so as to apply a certain pressure to the workpiece in the compression-tension direction. However, since the cost of manufacturing the abaver is high and the universal machine tool is polished There is a problem in that it is necessary to use only a modification.

Korean Unexamined Patent Publication No. 10-2015-0124318 discloses a computer numerically controlled machine tool capable of performing a polishing operation irrespective of a contact direction and a machining direction of a workpiece by causing a buffering action in response to a compressive force and a tensile force through a suspension assembly, However, since the first and second springs sharing the tensile compressive force of the suspension assembly are installed in parallel in the axial direction with different elastic forces, there is a problem that the tensile compressive force varies as the abrasive surface wear proceeds.

Document 1: Korean Patent Publication No. 10-2015-0124318

SUMMARY OF THE INVENTION It is an object of the present invention to provide an abrasive tool holder capable of continuously grinding a material to be polished in a compressive tensile direction at a constant pressure.

Another object of the present invention is to provide an abrasive tool holder capable of improving work productivity by extending the replacement time of the polishing brush, and improving the quality by making the roughness of the abrasive to be constant.

An object of the present invention is to provide a cylindrical rotary sleeve which is inserted into and coupled to an arbor of a machine tool and receives rotational force, an upper spring and a lower spring which are vertically movably received in the inner cylindrical space of the rotary sleeve, And a suspension assembly that includes a spring and rotates by receiving a rotational force from the rotating sleeve.

In order to accomplish the object of the present invention, a rotating sleeve includes a sleeve shaft inserted and coupled to an arbor of a machine tool to receive a rotational force, an end disk integrally formed at a lower end of the sleeve shaft, and an end disk integrally extending downward from an edge of the end disk, And a key groove formed on the inner wall surface of the cylindrical body at predetermined intervals in the axial direction.

Further, the suspension assembly includes: a piston body which is in close contact with a wall surface in the sleeve space and moves up and down freely; A spring receiving wall and spring seating space in which the upper end of the piston body is cylindrically recessed to receive the upper spring; A shaft main body and a shaft stem portion extending in the axial direction longer than a lower end portion of the piston body and having a hollow in which a rotary shaft of the polishing brush is inserted and fixed at a central portion; A rotary shaft fixing nut formed in the axial stem portion end region; An insertion space wall and a spring insertion space in which a circular space is axially formed between the axial stem portion and the lower portion of the piston body so that the lower spring is inserted and supported; A key guide formed on one side of the outer wall of the substantially middle region of the piston body so as to be recessed in a predetermined axial direction; A bolt inserted between the key guide of the piston body and the keyway of the rotary sleeve; And an upper spring and a lower spring which are seated on the upper portion of the piston body and inserted into the lower portion to suspend the piston body by elastically supporting the piston body in the compression and tension directions.

The lower end of the lower spring inserted into the surf pension assembly includes an annular spring bearing; And a snap ring which is located at the bottom of the spring bearing and which is inserted and fixed in the locking groove of the rotary sleeve.

As described above, the present invention can be applied to a polishing apparatus in which a suspension assembly of an abrasive tool holder equipped with an abrasive tool / abrasive brush can be continuously polished to a predetermined pressure in both compression and tensile directions by elastic support and suspension action by upper and lower springs It is effective.

In addition, the tool surface of the polishing brush, which is elastically supported at a constant pressure in both directions of the compression tension, is constantly worn to increase the life span and the replacement time, thereby improving the productivity. The tool surface of the abrasive brush, Can maintain the uniformity of the abrasive to be polished, thereby improving the quality.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view (a) and an incisional view (b) of an arbor equipped with an abrasive tool holder of the present invention.
2 is a sectional view of the polishing tool holder of Fig.
Figure 3 is an exploded cross-sectional view of the study tool holder of Figure 2;
Fig. 4 is a perspective view of Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the present invention, the parts described above or below refer to the states shown in the drawings in a simplified manner, and the designations can also be expressed to the left and right.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view (a) and an incisional view (b) of an arbor equipped with an abrasive tool holder of the present invention. 2 is a side cross-sectional view showing an enlarged view of the polishing tool holder 00 of Fig.

As shown in the figure, the polishing tool holder 00 of the present invention is generally inserted into a numerical control machine tool or an arbor A of a machining center and receives a rotational force to rotate the polishing brush B, Adjust the roughness of the same abrasive. At this time, the abrasive tool holder 00 is connected to the arbor (A) and fixed to be rotatable.

FIG. 3 is a cross-sectional perspective view of the research tool holder of FIG. 2, and FIG. 4 is a cross-sectional perspective view of FIG. 3. As shown in the figure, the polishing tool holder 00 includes a cylindrical rotating sleeve (100), and a suspension assembly (200) received in the rotary sleeve (100) to rotate the polishing brush (B).

The rotary sleeve 100 includes a rod-shaped sleeve shaft 110 into which an arbor A is inserted at an upper end, an upper circular portion 120 at a lower end integrally with the sleeve shaft 100, The sleeve body 140 is cylindrically formed and the sleeve cylindrical space 130 is formed therein.

The inner wall of the sleeve body 140 is recessed toward the axial direction to form a key groove 152 and the inner wall of the lower end is recessed in the circumferential direction to form a locking groove 154 into which the snap ring 170 is inserted .

3 to 4, the upper spring 230 and the lower spring are engaged with each other at both ends of the suspension assembly 200 so as to be elastically supported, and the suspension assembly 200 is vertically movable in the sleeve cylindrical space 130 of the sleeve body 140 .

3 to 4, the upper end of the piston body 210 located at the upper portion of the suspension assembly 200 includes a spring receiving wall body 252 which is recessed in a cylindrical shape and receives the upper spring 230, A seating space 250 is formed. The lower end of the suspension assembly 200 is axially extended from the lower end of the piston body 210 and has a shaft center portion 222 and a shaft stem portion 220, Is formed.

A rotary shaft fixing nut 224 is formed on one side of the end of the axial stem part 220 so that the shaft of the polishing brush B is inserted and fixed.

A circular space is axially recessed between the axial stem portion 220 and the lower portion of the piston body 210 to form a space for inserting the insertion space wall 262 and a spring insertion space 260 so that the lower spring 240 is inserted and supported .

A key guide 270 is formed on one side of the outer wall of the middle part of the piston body 210 so as to be axially recessed in a predetermined axial direction. The key guide 270 formed on the piston body 210 and the key guide 270 formed on the rotary sleeve 100 The keyway 152 is engaged in a facing manner. A bolt 28 is inserted and assembled into a space formed between the key guide 270 and the key groove 152.

The bolt 28 assembled between the key guide 270 and the key groove 152 transmits the rotational force of the rotary sleeve 100 to the piston body 210 to synchronously rotate the suspension assembly 200 to the rotary sleeve 100 At the same time, the key guide 270 and the key groove 152 are freely moved to move the suspension assembly 200 freely in the vertical direction.

The lower end of the lower spring 240 inserted in the axial stem portion 220 of the surf pension assembly 200 is supported by an annular spring bearing 160 and the spring bearing 160 is supported by a lower retaining ring 170 ). At this time, the retaining ring 170 is inserted and fixed in the retaining groove 154, which is recessed in the circumferential direction of the inner wall of the lower end of the rotary sleeve 100.

In this manner, the surf pension assembly 200 equipped with the polishing brush B is elastically supported in both directions of the upper and lower springs 230 and 240 to continuously polish the object to be polished at a constant pressure in both directions of compressive tension in the suspension state I will.

Accordingly, the tool surface of the polishing brush B, which is coupled to the axial stem portion 220 of the surf pension assembly 200 and is elastically supported at a constant pressure in both directions of compression tension, is uniformly worn, . In addition, a certain pressure acts on the tool surface of the abrasive brush B, which is constantly abraded, so that the illuminance of the abrasive to be polished can be kept constant, thereby improving the quality.

A: Arbor B: Abrasive brush
00: abrading tool holder 100: rotating sleeve
110: sleeve shaft 120: upper circular part
130: sleeve cylindrical space 140: sleeve body
152: keyway 154: latching groove
160: Spring bearing 170: Snap ring
200: Suspension assembly 210: Piston body
220: Axial stem portion 222:
224: Rotation shaft fixing nut 230: Upper spring
240: lower spring 250: spring seat space
252: spring receiving wall 260: spring insertion space
262: insertion space wall 270: key guide
280: Volky

Claims (5)

There is provided an abrasive tool holder which is mounted on an arbor of a machine tool that receives a rotational force of a numerically controlled machine tool or a machining center to insert and fix an abrasive brush for abrading an abrasive to be polished,
A cylindrical rotating sleeve inserted into the arbor of the machine tool to receive a rotational force and having a lower end opened; And
And a suspension assembly including a top spring and a bottom spring elastically supported by the top and bottom of the rotating sleeve and being rotatable by receiving a rotational force from the rotating sleeve, Abrasive tool holder.
The method according to claim 1,
Wherein the rotary sleeve includes: a sleeve shaft inserted and coupled to an arbor of the machine tool to receive a rotational force; A cylindrical upper body integrally formed at a lower end of the sleeve shaft and a sleeve body integrally extending downward from an edge of the upper end circular plate to form a sleeve space; A key groove formed on the inner wall surface of the cylindrical body at predetermined intervals in the axial direction; And an engaging groove formed by recessing the inner peripheral surface of the lower end of the cylindrical body.
The method according to claim 1,
The suspension assembly includes: a piston body which is in close contact with a wall surface in the sleeve space and moves up and down freely; An axial stem portion extending in an axial direction longer than a lower end portion of the piston body and having a hollow in which a rotary shaft of the polishing brush is inserted and fixed at a central portion; And an upper spring and a lower spring mounted on an upper portion of the piston body to suspend the piston body by elastically supporting the piston body in a compression and tension direction.
The method according to claim 1 or 3,
The suspension assembly includes a spring receiving wall and a spring seating space, the upper end of the piston body being cylindrically recessed to receive the upper spring;
A rotary shaft fixing nut formed in the axial stem portion end region;
An insertion space wall and a spring insertion space in which a circular space is axially formed between the axial stem portion and the lower portion of the piston body and the lower spring is inserted and supported;
A key guide formed on an outer wall of a substantially middle region of the piston body to be axially recessed in a predetermined section; And
And a bolt inserted between a key guide of the piston body and a key groove of the rotating sleeve.
The method according to claim 1 or 3,
The lower end of the lower spring inserted into the surf pension assembly includes an annular spring bearing; And a resiliently supported abrasive tool holder which is located at a lower portion of the spring bearing and fixed in the axial direction by a snap ring which is inserted and fixed in the engaging groove of the rotary sleeve.

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