JPH0796437A - Tool holder - Google Patents

Abstract

PURPOSE:To enable high rigidity holding without causing shaft center slippage by way of certainly making both of a flange part and a tapered part contact with a spindle and holding them by providing a thin part for enabling the tapered part and the flange part to relatively and elastically displace in the axial direction of the spindle. CONSTITUTION:As a thin part 55 formed between a tapered part 51 and a flange part 52 of a tool holder works as a disc spring, the tapered part 51 and the flange part 52 can microscopically displace. Consequently, by tensile force of a grip part 108, while the flange part 52 of the tool holder makes contact with the head end of a spindle 102, the tapered part 51 is pulled in the backward direction until a tapered hole 105 completely makes contact with the tapered part 51. Consequently, the tool holder is installed on the spindle 102 in a two-plane constraint state where the tapered part 51 and the flange part 52 make contact with the spindle 102.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool holder mounted on a spindle of a machine tool.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 5, when a tool holder 6 is mounted on a spindle 2 of a machine tool such as a machining center, the taper of the tool holder 6 is disclosed in Japanese Patent Application No. 63-124677. The pull stud 7 fixed to the end face of the portion 6a is grasped by the grasping member 8 provided at the tip of the push rod 4, the pull stud 7 is pulled by the urging force of the clamp spring 12, and the tapered portion 6a of the tool holder 6 is moved to the main spindle. It was held in contact with the tapered hole 5 of No. 2. In this case, the tool holder 6 is held only by the taper portion 6a, and the flange end surface 6b of the tool holder 6 has the spindle 1
There was no contact with the tip surface of the and there was a gap d.

However, since the machine tool is required to perform high-speed machining, it is necessary to align the tool holder 6 with high accuracy and to maintain high rigidity, so that the taper portion 6a and the end surface 6b of the flange portion are simultaneously brought into contact with each other. Was required to hold the tool holder. In response to this request, as shown in FIG.
A tool holder 16 is used in which the taper portion 16a and the flange end surface portion 16b are subjected to high precision processing so that the taper portion 16a and the flange end surface portion 16b come into contact with both the taper hole 5 and the tip end surface of the spindle. In addition, 7
0 is a tool fixed to the tool holder 16.

[0004]

However, the tool holder 16 described above requires high-precision machining on both the spindle 2 and the tool holder 16, and depending on machining errors, the abutment of the flange end face 16b may be weakened. The contact of the tapered portion 16a is weakened, and the constraint accuracy of the tool holder 16 with respect to the spindle 2 is affected. Further, when the spindle 2 rotates at a high speed, the tapered hole 5 expands due to the centrifugal force, weakening the contact of the tapered portion 16a, which causes the axial center of the tool holder 16a to shift.

Therefore, the tool holder of the present invention can maintain the compatibility with the conventional tool holder, and at the same time, the taper portion and the flange end surface are brought into contact with the main shaft at the same time to achieve highly accurate axial center alignment and high rigidity retention. The purpose is to provide a simple tool holder.

[0006]

In order to solve the above-mentioned problems, a taper portion to be inserted into a taper hole for attaching a tool holder formed at a tip of a spindle of a machine tool and a tip surface of the spindle are provided. In a tool holder having a flange portion having an abutting end face, a groove is provided at a boundary portion between the tapered portion and the flange portion or a tip of the main shaft, and a hole is formed in the flange portion on the opposite side to the tapered portion. A thin wall portion is provided to allow the tapered portion and the flange portion to be elastically displaced relative to each other in the axial direction of the main shaft by the hole and the groove.

[0007]

The tool holder of the present invention is chucked on the spindle of a conventionally used machine tool. The pull stud provided on the end surface of the taper portion of the tool holder is gripped by the grip portion of the machine tool and pulled in the spindle retreating direction, so that the flange portion of the tool holder contacts the end surface of the spindle. The thin portion formed by the flange and the end surface of the hole acts as a disc spring, and the tapered portion and the flange are within the range of the groove provided at the boundary between the tapered portion and the flange portion or at the end of the spindle. Since the flange portion is elastically displaceable in the direction, the taper portion is pulled in the backward direction until the taper portion is in contact with the taper hole while the flange portion is in contact with the tip of the main shaft. As a result, the tool holder can be mounted on the spindle in a two-face restrained state in which both the flange portion and the taper portion are in contact with the spindle.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a spindle head of a conventional machine tool that holds a tool holder 50 according to an embodiment of the present invention. 1
Reference numeral 01 is a spindle head, and 102 is a cylindrical spindle that is rotatably supported by the bearing on the spindle head 101. A push rod 104 is inserted through a shaft hole 103 of the main shaft 102 so as to be movable back and forth (left and right in the drawing) in the axial direction of the main shaft 102. The gripping member 10 for gripping the pull stud 59 projecting from the tool holder 50 at one end of the push rod 104, that is, at the end of the main shaft 102 for fixing the tool holder 50, which will be described later, on the side of the tapered hole 105.
8 is attached. The grip member 108 is retracted in the guide sleeve 109 by the rearward movement of the push rod 104 (to the right in the drawing), and is contracted in the radial direction.
When the push rod 104 moves forward (to the left in the drawing), the push rod 104 projects from the guide sleeve 109 and expands in the radial direction.

A stopper 111 is fixed to the other end of the push rod 104, and a spring receiver 110 abutting against the stopper 111 is slidably fitted to the push rod 104. The spring receiver 110 receives the urging force of a clamp spring 112 such as a disc spring installed along the push rod 104 in the shaft hole 103, and normally the push rod 104 is provided via the stopper 111.
Is pressed in the fixing direction of the tool holder 50, that is, rightward in the drawing.

Reference numeral 114 is an unclamping device main body. The unclamp device main body 114 has the spring receiver 1
It has an unclamping cylinder 115 in which a piston 116 that abuts 0 is provided, is supported by a support bolt 117 so as to be movable in the spindle axis direction with respect to the spindle head 101, and is usually a spring 118 on the spindle head 101 side. It is pressed and positioned in place.

Further, the unclamp device main body 114
Is a contact member 119 fixed to the rear end of the main shaft 102.
The thrust bearing 120 that abuts on the spring receiver 110 is provided so that the piston 116 moves forward (to the left in the drawing).
Is pressed to move the unclamping device 114 backward by reaction force when unclamping when the clamping spring 112 is pressed in the compression direction.
0 contacts the contact member 119 and clamp spring 1
The spring force of 12 does not act on the main shaft bearing.

Reference numeral 121 denotes the unclamp device body 114.
Is a push rod operating cylinder that is integrally provided with the push rod 104, and has a piston rod 122 that moves forward and backward on the same straight line as the push rod 104. The front end face of the piston rod 122 faces the rear end face of the push rod 104 so that it can come into contact with the piston rod 122.
A cylindrical engagement member 123 having a is fixed.

The rear end of the push rod 104 penetrates the protrusion 124 and is inserted into the engaging member 123, and an engaging portion 125 that engages with the protrusion 124 is formed. Reference numerals 113a and 113b denote drive gears fixed to the main shaft 2, and 113c denotes a shift gear for shifting. Next, a tool holder 50 showing an embodiment of the present invention will be described.
FIG. 2 is a front view including a partial cross section of the tool holder 50 of this embodiment. The tool holder 50 is the spindle 10 of the machine tool.
The taper part 51 inserted in the taper hole 105 of No. 1 and the flange part 52 in which the tool holding arm of a machine tool (not shown) holds the tool holder 50 are formed. Tool mounting holes 53, which are holes for mounting various tools 70, are formed in the flange portion 52. A groove 56 is formed on the circumference of the joint portion between the taper portion 51 and the flange portion 52, and a thin thin portion 55 is formed by the end surface 53a of the tool mounting hole 53 and the groove 56. This thin part 55
Acts as a disc spring so that the flange 52 and the taper portion 51 can be slightly displaced. In addition, the taper portion 51
A pull stud 59 that holds the tool holder 50 by the holding member 109 of the machine tool described above is fixed to the end surface of the. Reference numeral 57 is a key groove, which engages with a key provided at the tip of the spindle 1 when the tool holder 50 is attached to a machine tool to prevent the tool holder 50 from rotating and slipping with respect to the spindle. .

Numeral 70 is a tool, and a pedestal 72 has a tool main body 7
1 is fixed. The pedestal 72 is provided with a convex portion 72a that fits into the tool mounting hole 53. The convex portion 72a
Is fitted into the tool mounting hole 53, and the tool 72 is
0 is positioned and fixed to the tool holder 50. At this time, the convex portion 72a of the pedestal 72 does not include the entire tool attachment hole 53, and a space 74 exists between the end surface of the convex portion 72 and the tool attachment hole 53. In addition, the hole in a claim shows the tool attachment hole 53 in a present Example.

With the above construction, the tool holder 50 of the embodiment
The action of will be described with reference to FIG. The tapered portion 51 of the tool holder 50, which is gripped by an exchange arm provided in a machine tool (not shown), is inserted into the tapered hole 105. Pull stud 5 provided on the end surface of the tapered portion 51 of the tool holder 50
9 is gripped by the grip of the machine tool and pulled in the spindle retracting direction, and the flange portion 52 of the tool holder 50 causes the spindle 10 to move.
Abutting on the end face of 2 (state in the upper part of the drawing). Tool holder 5
The thin portion 55 formed between the zero taper portion 51 and the flange portion 52 acts as a disc spring so that the taper portion 50 and the flange portion 52 can be slightly displaced. Therefore, in the tool holder 50, the taper portion is pulled backward by the pulling force of the grip portion 108 until the taper portion 51 is completely brought into contact with the taper hole 105 while the flange portion 52 is kept in contact with the tip of the main shaft 102. (State below the drawing). As a result, the tool holder 50 is mounted on the spindle 102 in a two-face restrained state in which both the tapered portion 51 and the flange portion 52 are in contact with the spindle 102.

The tool holder 50 of this embodiment described above.
Forms the thin wall portion 55 by the tool mounting hole 53 and the groove 56, but as shown in a modified example in FIG. 4, the thin wall portion 55 is formed by the tool mounting hole 53 and the end surface of the flange portion 52, The groove 2a may be provided at the tip of the tapered portion of 2.

[0017]

As described above, the tool holder of the present invention ensures compatibility with conventional tool holders, and at the same time, special high-precision machining is performed on the taper portion of the spindle and the tool holder and the flange end surface. Both the flange portion and the taper portion can be surely brought into contact with and held by the main shaft without applying them, and high rigidity holding without axial misalignment can be achieved. Further, even if the taper portion expands due to centrifugal force during high-speed rotation of the main spindle, the thin portion is displaced following this, and the taper portion closely contacts the taper hole.

[Brief description of drawings]

FIG. 1 is a diagram in which a tool holder showing an embodiment of the present invention is mounted on a spindle.

FIG. 2 is a view showing a tool holder showing an embodiment of the present invention.

FIG. 3 is a view showing the operation of the tool holder showing the embodiment of the present invention.

FIG. 4 is a view showing a tool holder showing a modified example of the present invention.

FIG. 5 is a view in which a conventional tool holder is mounted on a spindle of a machine tool.

FIG. 6 is a view in which a conventional tool holder is mounted on a spindle of a machine tool.

[Explanation of symbols]

 2 spindle 2a groove 50 tool holder 51 taper portion 52 flange portion 53 tool mounting hole 55 thin portion 56 groove 59 pull stud 101 spindle head 102 spindle 105 taper hole 108 gripping portion

Claims (1)

[Claims] 1. A taper portion to be inserted into a taper hole for attaching a tool holder formed at a tip of a spindle of a machine tool,
In a tool holder having a flange portion having an end surface that comes into contact with the tip end surface of the main shaft, a groove is provided at a boundary portion between the taper portion and the flange portion or a tip end of the main spindle, and the flange portion is provided on the opposite side of the taper portion. A tool holder, characterized in that a hole that opens is provided, and a thin portion that allows the tapered portion and the flange portion to be elastically displaced relative to each other in the axial direction of the main shaft by the hole and the groove.