JP4119577B2 - Tool holder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tool holder that is replaceably attached to a spindle end portion of a processing machine, and more particularly, to a general-purpose tool holder that does not shrink in size to the tool tip even when the spindle rotates at high speed.
[0002]
[Prior art]
In an NC processing machine or the like, machining is performed while exchanging various tools such as a drill. Therefore, each tool is attached to each tool holder in advance, and a robot or the like appropriately attaches the tool holder to which the corresponding tool is attached. It is selected and attached to the tip of the spindle of the processing machine.
[0003]
A cutting tool is attached to the tip of the tool holder described in Japanese Patent Application Laid-Open No. 5-337769, and a taper portion that is an attachment part of the tool holder is in a tapered hole provided in the tip of the spindle of the processing machine. By being pulled in and fixed, both tapered portions are closely fitted and the tool holder is firmly attached to the processing machine spindle.
[0004]
In this prior art, when the tool is rotated at a high speed like a drill or the like, if the high-speed rotation state of several thousand to several tens of thousands rpm, it is possible to avoid the taper hole of the main shaft from slightly expanding due to centrifugal force. Can not. In particular, when the diameter of the taper hole of the main shaft is increased, in the tool holder configured to be drawn into the main shaft, the taper portion is drawn into the main shaft, and the distance to the tool tip is reduced. This makes ultraprecision machining impossible.
[0005]
Therefore, in the prior art described in Japanese Patent No. 2571325, when the tool holder is mounted on the main shaft tip, processing is performed so that the end surface of the tool holder comes into contact with the front surface of the main shaft with high accuracy. Even if the taper hole is enlarged by rotating at a high speed, the end face of the collar portion comes into contact with the front end face of the main shaft so that the tool holder is not drawn into the main shaft.
[0006]
[Problems to be solved by the invention]
As described above, if the tool holder is manufactured such that the end face of the flange comes into contact with the tip end face of the spindle with high accuracy, the problem that occurs as the spindle rotates at high speed is solved. However, there is a problem with the processing machine that the dimensions of the tip end of the spindle vary depending on the manufacturer and model.
[0007]
If the tool holder supply side manufactures a single tool holder with high accuracy according to individual differences on the processing machine side, the manufacturing cost will be too high. In addition, since it becomes impossible to use a tool holder for a certain processing machine for an adjacent processing machine, there arises a problem that all necessary tools, that is, tool holders, must be prepared for each processing machine.
[0008]
An object of the present invention is to provide a tool holder that can be used for general purposes and whose dimensions to the tool tip do not change even when the main shaft rotates at a high speed.
[0009]
[Means for Solving the Problems]
The purpose is to have a tapered shank portion and a main body having a diameter larger than that of the shank portion. The shank portion is fitted into a taper hole provided in the main shaft of the processing machine, and the tip end portion of the shank portion is inside the main shaft by a pulling tool. In a tool holder configured such that the front end surface of the main shaft and the end surface of the main body facing the front end surface are separated from each other by a predetermined distance in the state where the main shaft is pulled in, the radial direction drilled in the main body A first bottomed hole; a second bottomed hole continuously bored in the first bottomed hole from an end surface side of the main body; and the main body movably provided in the second bottomed hole An anti-vibration member protruding from the end face toward the end face of the main shaft, and a centrifugal force generated when the main shaft is rotated in the first bottomed hole and slidable in the radial direction. It slides in the bottomed hole and slidably contacts the vibration isolating member and presses the vibration isolating member against the spindle end face side. The holder supporting device having a cardiac member, by providing a plurality in a circumferential direction of the body, is achieved.
[0010]
When the main shaft rotates and the taper hole tries to expand due to centrifugal force, the centrifugal member receiving the centrifugal force slides radially in the first bottomed hole and presses the vibration isolating member against the sliding surface. To do. Thereby, the vibration isolating member is pressed against the end surface of the main shaft, and the tool holder is prevented from falling into the tapered hole. At this time, since the vibration isolating members of the plurality of holder support devices all function in the same manner, the tool holder is supported at a right angle to the main shaft. When this tool holder is mounted on another spindle with individual differences, the length of the anti-vibration member projecting toward the spindle end surface changes, so it can be mounted on a machine with individual differences. .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a tool holder according to an embodiment of the present invention. As is well known, a taper hole 2 is formed in the center axis of the existing processing machine spindle front end 1. The tapered hole 2 increases in diameter as it goes to the main shaft front end surface 3 side, and opens at the main shaft front end surface 3. The tool holder 10 is attached to the tapered hole 2.
[0012]
A shank portion (tapered portion) 11 protruding from the back of the main body of the tool holder 10 is provided in a conical shape so as to be aligned with the tapered hole 2, and the main body of the tool holder 10 is attached to the shank portion 11. An annular recess 12 is formed in the large-diameter portion so that a robot or the like (not shown) grips the tool holder 10.
[0013]
As is well known, a screw hole 13 is threaded at the tip of the shank 11 of the tool holder 10, and a pull stud 40 is screwed into the screw hole 13. By pulling the pull stud 40 by the pulling tool 41 on the processing machine side, the shank portion 11 of the tool holder 10 is closely fitted into the tapered hole 2, and the tool holder 10 is firmly attached to the spindle tip 1. It is configured to be attached integrally.
[0014]
A holder support device 20, which is a feature of the present embodiment, is provided on the flange portion 14 on the shank portion 11 side of the annular recess 12 of the large diameter portion of the tool holder 10. FIG. 2 is a detailed cross-sectional view of the holder support device 20, and FIG. 3 is a view of the tool holder viewed from the direction of arrow A in FIG.
[0015]
A plurality of holder support devices 20 are provided in the tool holder. Preferably, since it is necessary to support the axis of the tool holder at right angles to the spindle of the processing machine, it is preferable to provide at least three. In the present embodiment, as shown in FIG. 3, eight holder support devices 20 are provided in line symmetry with respect to the center line C by four. In the present embodiment, the cutouts 16 and 17 are provided for other purposes on the center line C of the collar portion 14. However, if the cutouts 16 and 17 do not need to be provided, they are held. The tool support device 20 may be provided evenly on the flange 14.
[0016]
2A is a cross-sectional view of the holder support device 20 when the main shaft is stationary, and FIG. 2B is a cross-sectional view of the holder support device in a state where the main shaft is rotating. . FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG.
[0017]
In FIG. 2 (a), the holder support device 20 is provided in a bottomed hole 21 that is formed in a radial direction from the outer peripheral side of the flange portion 14 toward the axial center. Consists of members. One is a centrifugal member 22 that slides in the radial direction (in the direction of arrow D in the figure) by the centrifugal force when the tool holder 10 is rotated to generate centrifugal force, and the other is a centrifugal member 22. The anti-vibration member 30 moves in the direction of the arrow E in the same direction as the shaft center by the reaction force from the centrifugal member 22 when the centrifugal member 22 slides in the radial direction while making contact with the inclined surface.
[0018]
The centrifugal member 22 is made of metal, and its bottom 23 (axial center side of the tool holder) is in close contact with the inner wall surface 21a of the bottomed hole 21, so that the movement of the centrifugal member 22 is the radial direction of the tool holder 10. Regulated only to. A bottomed hole 24 is formed on the upper side of the centrifugal member 22 (in the outer peripheral direction of the tool holder), and a spring 25 is contracted in the bottomed hole 24, and at the entrance of the bottomed hole 24. Since the push pin 26 that presses the spring 25 is slidably inserted, the distal end of the push pin 26 comes into contact with the lid 29 of the bottomed hole 21, so that the centrifugal member 22 is caused by the elastic force of the spring 25. The bottomed hole 21 is always urged toward the bottom side.
[0019]
A portion 27 on the upper side of the centrifugal member 22 and on the main shaft tip portion 1 side is cut into a semi-cylindrical shape, and the vibration isolation member 30 is attached to the cutting portion 27 so as to be able to appear and retract. An inclined surface 28 of about 20 degrees is formed at a portion of the cutting portion 27 that comes into contact with the vibration isolator 30 head. When the centrifugal member 22 slides in the outer peripheral direction (arrow D direction) of the tool holder 10 against the elastic force of the spring 25 by the centrifugal force, the inclined surface 28 moves the vibration isolating member 30 in contact with the arrow E. Functions to push in the direction.
[0020]
The vibration isolator 30 is made of metal and is formed in a circular or prismatic shape. A bottom surface 30a on the main shaft tip 1 side of the vibration isolator 30 is formed in a flat shape, and a head that abuts on the inclined surface 28 is formed in a conical shape. The vibration isolating member 30 is slidably accommodated in the hole 15 continuously drilled in the bottomed hole 21 from the end surface 14 a facing the spindle front end surface 3 of the flange portion 14, and its head abuts against the inclined surface 28. However, in order to rotate or fall off as it is, the vibration isolator 30 is provided with a hole 31 penetrating in the diametrical direction directly below the head, and a long anti-rotation pin 32 is inserted into the hole 31. ing.
[0021]
In the holder support device 20 having such a configuration, after the centrifugal member 22 having the spring 25 and the pin 26 mounted therein is accommodated in the bottomed hole 21, the vibration is prevented from the bottom side (counter arrow E side) of the flange portion 14. The member 30 is inserted, and the non-rotating pin 32 is inserted into the hole 31. Finally, the male screw-like lid 29 is screwed onto the female screw threaded on the inner peripheral wall of the inlet of the bottomed hole 21. In this case, the lid body 29 is assembled to the flange portion 14 with an arbitrary stopper (screw) or the like.
[0022]
When the tool holder 10 is mounted on the spindle of the processing machine, the spindle tip surface 3 and the flange end surface 14a facing the spindle are separated by a required distance. This distance varies depending on individual differences in processing machines.
[0023]
In the state where the main shaft is stopped, the centrifugal member 22 is biased in the axial direction of the tool holder 10 by the elastic force of the spring 25, so that no force is applied to the vibration isolating member 30 from the inclined surface 28. It is in a state (state in FIG. 2A).
[0024]
When the main shaft starts rotating and the main shaft tip 1 starts to expand in diameter by centrifugal force, the centrifugal member 22 slides in the radial direction (arrow D direction) against the elastic force of the spring 25 by centrifugal force. The inclined surface 28 pushes the vibration isolating member 30 toward the end surface 1 of the main shaft tip. In the case of the present embodiment, such an action similarly occurs in the eight holder support devices 20, so that the bottom surfaces 30 a of the eight vibration isolation members 30 are evenly pressed against the end surface of the spindle tip 1 to hold the tool. The tool 10 does not tilt the axis, prevents the shank portion 11 from entering the tapered hole 2, and pushes the inside of the tapered hole 2 by the shank portion 11 entering the tapered hole 2. As a result, the dimension from the end surface 3 to the tool tip at the spindle tip 1 does not change. (State of FIG. 2B).
[0025]
Further, even when the rotational speed of the main shaft increases and the tapered hole 2 expands, the vibration isolating member 30 is pressed by the centrifugal member 22 by a force corresponding to the centrifugal force of the main shaft, so that the dimension to the tool tip is reached. Is kept unchanged and the shaft center of the tool holder 10 is prevented from being shaken.
[0026]
In addition, as described above, since the vibration isolating member 30 receives the centrifugal force and moves forward and backward to prevent the tool holder 10 from falling into the tapered hole 2, the vibration isolating member 30 is the end face of the flange 14. It can be attached to a processing machine spindle having individual differences by a distance protruding from the spindle tip surface 3 from 14a, and it can be given versatility, and one kind of tool holder 10 has various individual differences. Can be attached to a processing machine.
[0027]
【The invention's effect】
According to the present invention, even when the main shaft rotates at a high speed, the risk that the tool holder falls into the taper hole of the main shaft and the size of the tool tip shrinks can be avoided as much as possible, and the axis of the tool holder blurs. Can be avoided, and it can be used universally for processing machines having individual differences.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a tool holder according to an embodiment of the present invention.
FIGS. 2A and 2B are cross-sectional views of the holder support device, in which FIG. 2A is a cross-sectional view when the main shaft is stopped, and FIG. 2B is a cross-sectional view when the main shaft is rotated.
3 is an arrow view of the tool holder viewed from the direction of arrow A in FIG.
4 is a cross-sectional view taken along line IV-IV in FIG. 2 (B).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Main-axis front-end | tip part, 2 ... Tapered hole, 3 ... Main-axis front-end | tip surface, 10 ... Tool holder, 11 ... Shank part (taper part), 14 ... A collar part, 14a ... A collar end surface, 20 ... A holder support apparatus, DESCRIPTION OF SYMBOLS 21 ... Bottomed hole, 22 ... Centrifugal member, 23 ... Bottom part, 24 ... Bottomed hole, 25 ... Resilient spring, 26 ... Push pin, 27 ... Cutting part, 28 ... Inclined surface, 29 ... Cover, 30 ... Prevention Vibrating member, 31 ... through hole, 32 ... detent pin, 40 ... pull stud, 41 ... drawing tool.

Claims (4)

The shank has a tapered shank and a main body having a diameter larger than that of the shank. The shank is fitted into a taper hole provided in the spindle of the processing machine, and the tip of the shank is drawn into the spindle by a pulling tool. In a state where the tip end surface of the main shaft and the end surface of the main body facing the front end surface are separated from each other by a predetermined distance, the first holding member in the radial direction drilled in the main body is provided. A bottom hole, a second bottomed hole continuously bored in the first bottomed hole from the end surface side of the main body, and a main shaft extending from the main body end surface so as to be movable in the second bottomed hole. An anti-vibration member that protrudes toward the end surface, and a centrifugal force generated when the main shaft rotates in the first bottomed hole so as to be slidable in the radial direction. A centrifugal member that slides against the vibration isolating member and presses the vibration isolating member against the main shaft end surface side. Tool holder, characterized in that the holder supporting device, provided plurality in the circumferential direction of the body to be. The tool holder according to claim 1, wherein the holder support device includes a resilient spring that biases the centrifugal member toward the center of the tool holder against the centrifugal force. The sliding contact surface of the centrifugal member that is in sliding contact with the vibration isolating member is an inclined surface according to claim 1, and the force received in the centrifugal direction of the centrifugal member by the inclined surface is the A tool holder that is configured to convert to a pressing force toward the spindle end face. 4. The tool holder according to claim 1, wherein at least three of the holder support devices are provided.

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