JPH06114612A - Tool holding device - Google Patents

Abstract

PURPOSE:To provide easy replaceability for tool holder relative to a spindle and allow the tool holder to be mounted certainly and precisely. CONSTITUTION:A tool holding device is composed of a tool holder 14, on which a drill 12 is attached, and a coupling means 18 which couples the tool holder !4 with the spindle 16 of a machine tool in such a way as rotating coaxially and in a single piece. The arrangement further includes a holding member 24, which is secured to the spindle 16 and which is furnished at the inside surface with an internally tapered surface 22 mating with an externally tapered surface 20 provided on the peripheral surface of the tool holder 14, and a plurality of rollers 26 which are interposed between the slide contacting parts of these two tapered surfaces 20, 22.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool holding device for exchangeably mounting various tools on the tip of a spindle of a machine tool.

2. Description of the Related Art Normally, in a machining center or the like, an automatic tool changer (ATC) is used to automatically change various tools. On the other hand, a tool holding device that attaches a tool in a replaceable manner to another machine tool, especially a spindle of a multi-axis machine tool, is used. In this tool holding device, however, the tip of the spindle is generally used. A cylindrical portion is provided in the portion, while the shank portion of the tool holder to which the tool is fixed is detachably fitted to the cylindrical portion of the spindle.

By the way, in the above prior art, the cylindrical portion of the spindle is a straight hole,
The straight shank portion of the tool holder is detachably attached to this straight hole. At that time, in order to smoothly perform the attachment / detachment work, it is necessary to provide a clearance between the straight hole and the straight shank portion, and between the spindle and the tool holder with the tool holder attached to the spindle, Rattling occurs in the radial direction. Therefore, it has been pointed out that when a working operation is performed in this state, the tool rattles and the working accuracy is lowered. Therefore, Morse taper, Brown sharp taper, Jacobs taper, etc. may be used.
All of these have self-locking taper, and a special tool is required for attaching and detaching the tool holder, which causes a problem that the attaching and detaching work becomes complicated. In addition, if you try to press and fix the tool holder to the inner peripheral surface of the cylindrical portion of the spindle (side lock method), the axis of this tool holder will be displaced from the axis of the spindle, and there will be problems such as large diameter machining holes. Occur. The present invention solves this kind of problem, and provides a tool holding device capable of easily exchanging various tools with respect to a spindle and mounting the tools reliably and highly accurately. The purpose is to do.

In order to achieve the above-mentioned object, the present invention provides a tool holder in which a tool is fixed and an outer peripheral surface of the tool holder is provided with an external taper surface that expands in the axial direction. Connecting means for attaching the tool holder to the spindle of the machine tool so as to be coaxially and integrally rotatable, and while being fixed to the spindle,
A holding member having an inner peripheral surface provided with an inner tapered surface corresponding to the outer tapered surface of the tool holder, and a plurality of rollers interposed in a sliding contact portion between the outer tapered surface and the inner tapered surface. , Is provided.

In the above tool holding device according to the present invention, when the tool holder is attached to the spindle, the outer tapered surface of the tool holder and the inner tapered surface of the holding member engage with each other. Therefore, the tool holder can be coaxially fixed to the spindle, and rattling or the like does not occur between the tool holder and the spindle. Moreover, since a plurality of rollers are interposed between the outer tapered surface and the inner tapered surface, the tool holder can be more firmly fixed to the spindle, while the outer tapered surface and the inner tapered surface are in close contact with each other. As a result, it becomes possible to prevent the removal work of the tool holder from becoming difficult, and it becomes possible to efficiently and easily carry out the replacement work of the tool holder.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A tool holding device according to the present invention will be described in detail below with reference to the accompanying drawings.
In FIG. 1, reference numeral 10 indicates a tool holding device according to this embodiment. This tool holding device 10 includes a tool holder 14 to which a tool, for example, a drill 12 is fixed, and a connecting means 18 for rotatably connecting the tool holder 14 coaxially and integrally with a spindle 16 of a machine tool. A holding member 24 fixed to the spindle 16 and provided with an inner tapered surface 22 corresponding to the outer tapered surface 20 provided on the outer peripheral surface of the tool holder 14 on the inner peripheral surface thereof; Surface 20 and internal tapered surface 22
And a plurality of rollers 26 that are interposed in a sliding contact portion with. The spindle 16 is provided with a cylindrical portion 28 having a predetermined length at its tip portion, and a screw hole 30 is formed in the outer peripheral portion of the cylindrical portion 28 in the radial direction. A rotary drive source (not shown) is connected to the rear end side of the spindle 16. The connecting means 18 is the spindle 16
A coupling member 38 fixed to the bottom surface 32 of the cylindrical portion 28 via a bolt 34 and a pin 36, and a coupling portion 40 provided at the end of the tool holder 14. This connecting member 3
A multi-threaded screw hole 42 is formed on the inner peripheral surface of 8, and a multi-threaded screw portion 44 that is screwed into the multi-threaded screw hole 42 is formed on the outer peripheral surface of the connecting portion 40. A multi-threaded screw structure is constituted by and the multi-threaded screw portion 44. The tool holder 14 has a hole 46 and a screw hole 48 coaxially provided in the center thereof, and a tool such as the drill 12 is provided in the hole 46.
Are fixed via the sleeve 50. A screw member 52 is screwed into the screw hole 48, and the screw member 52 comes into contact with the rear end portion of the drill 12 to adjust the protrusion amount of the drill 12. A straight shank portion 54 is provided on the outer peripheral portion of the tool holder 14 so as to be continuous with the connecting portion 40 and fits into the cylindrical portion 28 of the spindle 16. , (See arrow X direction), an outer taper surface 20 is formed which expands radially outward by a predetermined angle α °. Holding member 24
Has a substantially cylindrical shape, and includes a cylindrical portion 56 into which the outer peripheral portion of the spindle 16 is fitted, and the cylindrical portion 56 has a hole 58.
Is formed, and a set screw 60 inserted into the hole 58 is screwed into the screw hole 30 of the spindle 16 to hold the holding member 24.
Are fixed to the spindle 16. The cage member 61 is fixed to the inner peripheral portion of the holding member 24, and the cage member 61 expands radially outward toward the front end side in the machining direction corresponding to the outer tapered surface 20 of the tool holder 14. The inner taper surface 22 and the plurality of rollers 26 are arranged such that their axes are at a predetermined angle θ in the circumferential direction with respect to the axis of the tool holder 14.
And a plurality of openings 62 for arranging them in a state of being inclined at an angle (see FIG. 2). In order to reliably transmit the rotation of the spindle 16 to the tool holder 14 via the holding member 24, a groove portion is provided at the tip end portion of the spindle 16 and a drive key engaging with the groove portion is provided at the holding member 24. May be. Next, the operation of the tool holding device 10 thus configured will be described. Spindle 1
When attaching the desired tool (drill 12) to 6,
First, the straight shank portion 54 of the tool holder 14 is fitted into the cylindrical portion 28 of the spindle 16. Then, when the tool holder 14 is rotated when the connecting portion 40 of the tool holder 14 abuts on the connecting member 38, the connecting portion 40 is rotated.
The multi-threaded screw portion 44 is screwed into the multi-threaded screw hole 42 of the coupling member 38, and the tool holder 14 is pulled toward the spindle 16 side. Therefore, the outer taper surface 20 of the tool holder 14 and the inner taper surface 22 of the cage member 61 have a plurality of rollers 26.
The tool holders 14 are slidably contacted with each other while being interposed, and the tool holder 14 is coaxially fixed to the holding member 24. Here, the holding member 24 is fixed to the spindle 16, so that the tool holder 14 is fixed to the spindle 16 coaxially and firmly. As described above, in this embodiment, the straight shank portion 54 of the tool holder 14 is fitted into the cylindrical portion 28 of the spindle 16 and the outer tapered surface 20 of the tool holder 14 becomes the inner tapered surface 22 of the cage member 61. Sliding contact. Therefore, even if there is a clearance between the straight shank portion 54 and the cylindrical portion 28, the outer taper surface 20 and the inner taper surface 22 are brought into sliding contact with each other, so that the tool holder 14 and the spindle 1
It is possible to prevent rattling and the like from occurring in 6 and to position the tool holder 14 and the spindle 16 coaxially. Further, in this embodiment, the outer tapered surface 20 and the inner tapered surface 2
A plurality of rollers 26 are provided between the roller 26 and the roller 2, and the axis of the roller 26 is inclined by a predetermined angle θ ° in the circumferential direction with respect to the axis of the tool holder 14. Therefore, when the outer tapered surface 20 and the inner tapered surface 22 are in sliding contact with each other, the roller 26 is bent and the tool holder 14 and the holding member 24 can be firmly fixed. Moreover, when the tool holder 14 is rotated in the loosening direction in order to perform the tool changing operation, the restoring force of the roller 26 presses the outer tapered surface 20 and the inner tapered surface 22 in the direction in which they are separated from each other. This can prevent the outer taper surface 20 and the inner taper surface 22 from tightly adhering to each other, which makes it difficult to remove the tool holder 14 from the spindle 16.
This has the advantage that the work of attaching and detaching the tool holder 14 can be performed simply and quickly at once. Furthermore, the multi-threaded screw hole 4 is formed on the inner peripheral surface of the connecting member 38 that constitutes the connecting means 18.
2 is formed, a multi-threaded screw portion 44 is formed on the outer peripheral surface of the connecting portion 40. Therefore, by simply rotating the tool holder 14 by 90 °, for example, the tool holder 14 can be pulled in the axial direction by a distance sufficient to fix the tool holder 14 to the spindle 16. This simplifies the operation of rotating the tool holder 14 during the attachment / detachment work of the tool holder 14, and particularly facilitates the automation of the attachment / detachment work of the tool holder 14. In this embodiment, the cage member 61 having the opening 62 for accommodating the roller 26 is fixed to the holding member 24, but instead of this, the cage member 61 is provided on the outer peripheral portion of the tool holder 14. Can be provided. Further, the outer taper surface 20 and the inner taper surface 22 are on the front end side in the processing direction (see the arrow X direction in FIG. 1).
Although the diameter is expanded outward in the radial direction toward, the conversely, the diameter may be decreased in the radial direction toward the front end side in the processing direction.

The tool holding device according to the present invention has the following effects. When the tool holder is attached to the spindle, the outer tapered surface of the tool holder and the inner tapered surface of the holding member engage with each other, so that the tool holder can be coaxially fixed to the spindle and There is no rattling between the holder and the spindle. Moreover, since a plurality of rollers are interposed between the outer taper surface and the inner taper surface, the tool holder and the holding member can be more firmly fixed, while the outer taper surface and the inner taper surface are fixed. It is possible to prevent the work of removing the tool holder from becoming difficult due to the close contact with the surface, and the work of exchanging the tool holder can be efficiently and easily performed.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a main part of a tool holding device according to the present invention.

FIG. 2 is a partial cross-sectional explanatory view showing an engagement state between an outer tapered surface and a roller which form the tool holding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Tool holding device 12 ... Drill 14 ... Tool holder 16 ... Spindle 18 ... Coupling means 20 ... External taper surface 22 ... Internal taper surface 24 ... Holding member 26 ... Roller 38 ... Coupling member 40 ... Coupling portion 42 ... Multi-threaded portion 44 ... Multi-threaded screw hole 54 ... Straight shank portion 61 ... Cage member

Claims (3)

[Claims] 1. A tool holder, in which a tool is fixed, and an outer taper surface that expands in diameter in the axial direction is provided on an outer peripheral surface of the tool holder, the tool holder being coaxial with a spindle of a machine tool. A connecting means for integrally rotatably attaching, fixed to the spindle, and on the inner peripheral surface thereof,
A holding member provided with an inner tapered surface corresponding to the outer tapered surface of the tool holder; and a plurality of rollers interposed at a sliding contact portion between the outer tapered surface and the inner tapered surface. Tool holding device. 2. The tool holding device according to claim 1, wherein the spindle is provided with a cylindrical portion having a predetermined length at a tip portion thereof, and the connecting means is fixed to a bottom surface of the cylindrical portion of the spindle. A tool holding device comprising: a coupling member, a coupling portion provided at an end of a shank portion of the tool holder, and a multi-threaded screw structure configured by the coupling member and the coupling portion. 3. The tool holding device according to claim 1, wherein the roller is arranged with its axis inclined circumferentially with respect to the axis of the tool holder. .