JP2577907B2 - Tool holder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a tool magazine, in which a tool is fixed using a pull stud bolt as in a machining center, and the tool is changed by an ATC device, that is, an automatic tool changing device. The present invention relates to a tool holder used for a machine tool of a type in which cutting tools are stocked.

[Related Art] In recent machining, as the demand for shortening the machining time is strongly demanded, the number of revolutions of the machine spindle is increasing and the feed speed is increasing.

In order to cope with such high speed and rapid feed of the machine tool, the tool holder is required to have high rigidity and high precision performance. That is, high rigidity is an indispensable requirement to withstand an increase in load due to rapid traverse, and high accuracy is necessary to prevent a reduction in machining accuracy due to a signal generated with high-speed rotation.

On the other hand, in a machine tool such as a machining center that fixes a tool holder using a pull stud bolt,
The pull stud bolt is fixed to the tool holder by screw fitting, and the pull stud bolt is pulled in by a pulling mechanism of the machine tool and fixed to the machine spindle together with the tool holder. Therefore, another fixing means is required to fix the cutting tool to the tool holder, and a Morse taper holder is known as a typical example.

This type has the advantage that the cutting tool can be attached to the machine spindle with high precision and high rigidity, but it is necessary to remove the entire tool holder from the machine spindle when changing the cutting tool, and moving heavy objects. It has the disadvantage that it has to be transported. Further, since the tool length changes each time the cutting tool is replaced, there is a disadvantage that the data must be changed each time. Furthermore, since the length of the cutting tool must first be set longer considering the regrind length for the wear of the cutting tool,
It is disadvantageous in terms of rigidity.

Therefore, the amount of wear of the cutting tool is corrected by moving the cutting tool forward, so that the required constant tool length is always secured, making it unnecessary to change the data.In addition, when replacing a tool, the entire holder can be replaced without removing the entire holder from the machine The so-called quick change stub holder is also used, but this type has a disadvantage that the fixing force of the blade is weak and the rigidity and precision cannot be increased due to the clearance.

[Object of the invention] An object of the present invention is to fix the holder body and the blade holder firmly by a tension mechanism on the machine side when the blade is attached to the machine spindle, and to hold the holder body in a standby state in the tool magazine. An object of the present invention is to provide a tool holder in which a fixing force with a blade holder is weakened so that a blade can be easily replaced with a very small force.

[Summary of the Invention] The gist of the present invention for achieving the above object is to provide a rear end portion of a cutting tool holder removably fitted inside a front side of a holder main body inserted into a spindle hole of a machine tool. By rotating the blade holder side by a quarter turn on the front end of a pull stud bolt fitted inside the rear side of the holder body so as to be non-rotatable and slightly movable in the axial direction with respect to the holder body. Means for detachably connecting in the direction, and means provided between a drive ring provided slidably in the axial direction on the outer periphery of the front end side of the blade holder in the axial direction and the holder body, and connected in the rotational direction, A tool holder, wherein when the pull stud bolt is pulled in by the pulling mechanism on the machine tool side, the holder body is fixed to the spindle hole by further retracting the blade holder toward the spindle side. You.

[Embodiment of the Invention] The present invention will be described in detail based on the illustrated embodiment.

FIG. 1 shows an embodiment of a tool holder according to the present invention,
A pull stud bolt 2 that is pulled in by a tension mechanism on the machine side is fitted into the rear inside of the holder main body 1 that is inserted into the shaft hole of the machine spindle S, and a cutting tool T such as a drill is gripped inside its front side. The cutting tool holder 3 is detachably fitted. The holder body 1 has a flange portion 5 following a shank portion 4 detachably fitted in a shaft hole of the machine main shaft S, and a key groove 6 for torque transmission is provided at a tip end. A straight hole 8 is provided in the holder body 1 as a hole for fitting the blade holder 3, following a tapered hole 7 whose inner diameter is gradually reduced from the opening at the tip end. It communicates with a pull stud bolt fitting hole 8a opening at the end. Pull stud bolt 2
Is mounted so as to be non-rotatable with respect to the holder body 1 by the pins 9 and to be able to move slightly in the axial direction. As is well known, the rear end of the pull stud bolt 2 has a predetermined shape so as to be able to engage with a pulling mechanism on the machine tool side, but the front end thereof can be engaged with the rear end of the blade holder 3. As shown in FIG. That is, a small-diameter cylindrical portion 11 and a medium-diameter flange portion 12 are provided from the large-diameter cylindrical portion 10 having a relatively large diameter to the tip, and parallel chamfered portions 12a are provided on both sides of the outer peripheral surface of the medium-diameter flange portion 12. 12b is provided. The distance W2 between the chamfered portions 12a and 12b is equal to or slightly larger than the diameter of the small-diameter cylindrical portion 11.
On the other hand, a groove 13 having a width W3 slightly larger than the interval W2 is provided at the rear end of the blade holder 3 which engages with the middle diameter flange portion 12, as shown in FIG. An inner hole 14 for locking the middle-diameter flange portion 12 is provided in the inner surface at the back.

4 (a) and 4 (b) show the dimensional relationship between the middle diameter flange portion 12 and the inner hole 14, and the diameter D2 of the middle diameter flange portion 12
Is smaller than the inner diameter D3 and is larger than the width W3 of the concave groove 13. Therefore, the chamfered portions 12a, 1
When the grooves 13 are aligned with the grooves 2b and then rotated by about 90 degrees, the medium-diameter flange portion 12 is fitted into the inner hole 14 and the outer wall portion 15 of the inner hole 14 is fitted. Is locked in.

A key groove 6 is provided on the outer periphery near the tip of the blade holder 3.
A substantially cylindrical drive ring 17 provided with a protruding key 16 that fits into the drive ring 17 is slidably fitted. This drive ring
The spring 17 is constantly pressed toward the keyway 6 by a spring 18, but its movement beyond a certain limit is restricted by a torque transmitting flange 19 provided on the blade holder 3 side as shown in FIG. The protruding key 16 protrudes from the flange 19 toward the machine through a notch 19 a provided in the flange 19, and the protruding portion is fitted into the key groove 6. A collet 20 having a tapered surface for fixing the cutting tool T is well-known inside the cutting tool holder 3.
The collet 20 is attached to and detached from the blade holder 3 by tightening or loosening a lock nut 21 attached to the tip of the blade holder 3.

When attaching the cutting tool holder 3 to which the cutting tool T is fixed by using the collet 20 to the holder main body 1, the phase of the concave groove 13 is matched with that of the chamfered portions 12 a and 12 b of the medium-diameter flange portion 12, and the cutting tool holder 3 is moved to the holder main body. 1 and then rotate the cutter holder 3 by about 90 degrees with respect to the holder body 1, the medium-diameter flange portion 12 engages with the inner hole 14 as described above, and the cutter holder 3 However, the movement in the axial direction is impossible. At this time, the mutual phases are determined so that the protruding keys 16 of the drive ring 17 fit into the key grooves 6.

In this state, the blade holder 3 is loosely engaged with the holder main body 1, but is restricted in both the rotation direction and the axial direction. In this state, when the pull stud bolt 2 is pulled in by a tension mechanism provided on the machine side as is well-known, the blade holder 3 is also pulled in together with the machine spindle S, and the blade holder 1 is also pulled through the blade holder 3. Firmly fixed.

Further, since the replacement of the blade holder 3 is performed outside the machine, the holder body 1 and the blade holder 3 are loosely engaged as described above, so that the drive ring 17 is attached to the blade T against the elasticity of the spring 18. When the tool holder 3 is disengaged from the pull stud bolt 2 by rotating the key groove 6 and the protruding key 16 by about 90 degrees, the tool holder 3 It can be extracted from the main body 1 as it is.

In the above-described embodiment, the case where the medium-diameter flange portion 12 is provided on the pull stud bolt 2 side and the concave groove 13 is provided on the blade tool holder 3 side in the engagement portion between the pull stud bolt 2 and the blade holder 3 is shown. However, the relationship may be reversed. That is,
A similar engagement can be achieved by providing a concave groove 13 on the pull stud bolt 2 side and a medium-diameter flange portion 12 on the blade holder 3 side.

In FIG. 1, the contact between the holder body 1 and the blade holder 3 in the axial direction is the tapered surface of the tapered hole 7, but may be the flange end surface instead of the tapered surface. Although FIG. 1 shows the case where the cutting tool T is a drill blade, it goes without saying that the present invention can be applied to various cutting tools such as a reamer and an end mill. Further, the blade holder is not limited to the collet chuck as shown in the embodiment, and for example, a holder integrated with the blade can be similarly applied.

[Effects of the Invention] As described above, the tool holder according to the present invention can firmly fix the holder main body and the blade holder by the pulling mechanism on the machine tool side when mounted on the machine spindle. On the other hand, in the state where the cutting tool is kept in the tool magazine, the engagement between the holder body and the cutting tool holder is loose, so that the cutting tool can be easily replaced with a light force without using a special tool. It becomes possible.

[Brief description of the drawings]

The drawings show an embodiment of the tool holder according to the present invention. FIG. 1 is a sectional view, FIG. 2 and FIG. 3 are perspective views of an engagement portion with a pull stud bolt, and FIG. ),
FIG. 5B is an explanatory view of the dimensional relationship of the engaging portions, and FIG. 5 is a perspective view of the torque transmitting means. Reference numeral 1 denotes a holder body, 2 denotes a pull stud bolt, 3 denotes a blade holder, 6 denotes a key groove, 10 denotes a large-diameter cylindrical portion, 11 denotes a small-diameter cylindrical portion, 12 denotes a medium-diameter flange portion, 13 denotes a concave groove, and 14 denotes an inner groove. A hole, 15 is an outer wall portion, 16 is a protruding key, 17 is a drive ring, 18 is a spring, 19 is a flange, 20 is a collet, and 21 is a lock nut.

Claims (1)

(57) [Claims] 1. A cutting tool holder, which is removably fitted inside a front side of a holder body inserted into a main shaft hole of a machine tool, is rotated inside the rear side of the holder body with respect to the holder body. Means for removably connecting the cutting tool holder side to the front end of the pull stud bolt, which is impossible and slightly movable in the axial direction, by rotating the cutting tool holder side by a quarter, and A drive ring provided on the outer periphery of the front end side so as to be slidable in the axial direction, and means for connecting the holder in the rotation direction, wherein the pull stud bolt is pulled in by a tension mechanism on the machine tool side. A tool holder for fixing the holder body to the spindle hole by further retracting the blade holder toward the spindle side.