JPH0760544A - Tap holder - Google Patents

Abstract

PURPOSE:To eliminate coming off of a tap and its breaking due to a servo delay by absorbing a difference between a moving amount of a spindle, commanded by N/C of an N/C unit-provided machine tool, and a self-advancing amount of the tap. CONSTITUTION:A spindle mounting part 12, mounted/removed on/from a spindle 31, is connected to a tap mounting part 16, mounting/removing a tap 32, through a leaf spring 20, and the tap mounting part 16 is connected slidably in a rotary shaft direction of the spindle 31 to the spindle mounting part 12. A difference between a moving amount of the spindle 31 and a self-advancing amount of the tap 32 is absorbed by deflecting the leaf spring 20 due to sliding the tap mounting part 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a tap holder for mounting a tap on a spindle when tapping is performed by a machine tool such as a machining center.

[0002]

2. Description of the Related Art When tapping with a machining center having a rigid tap function in an N / C device, a rigid tap holder 2 having a tap 3 attached to a spindle 1 is attached as shown in FIG. This rigid tap holder 2 has a built-in expansion / contraction and screw depth limiting device.
A command is distributed so that the rotation of the spindle 1 and the amount of movement thereof are synchronized with each other in accordance with the pitch of the tap 3. Therefore, the tap 3 should be able to be processed without expansion and contraction.

However, in reality, due to the phenomenon of servo delay, the amount of self-propelled movement of the tap 3 while cutting according to the rotation of the spindle 1 is more than that of the spindle 1 commanded by N / C. It progresses faster. As a result, there were variations in the screw depth due to the tap coming out, and a tap breakage accident.

[0004]

The problem to be solved by the present invention is to absorb the difference between the amount of movement of the spindle and the self-propelled amount of the tap, which is commanded by the N / C.

[0005]

A feature of a tap holder of the present invention is that it comprises a spindle mounting portion that is attached to and detached from a spindle of a machine tool with an N / C device, and a tap mounting portion that attaches and detaches a tap. And the tap mounting portion are connected via a leaf spring, and the tap mounting portion is connected to the spindle mounting portion so as to be slidable in the direction of the rotation axis of the spindle.

[0006]

The difference between the movement amount of the main shaft and the self-propelled amount of the tap is absorbed by the deflection of the leaf spring caused by the slide of the tap mounting portion, so that tap missing or tap breakage due to the servo delay does not occur.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, reference numeral 11 denotes a tap holder of the present invention, in which a machine tool with an N / C device, for example, a spindle mounting portion 12 which is detachably attached to a spindle 31 of a machining center, and a tap 32 are attached and detached. It is composed of the tap mounting portion 16.

Reference numeral 13 denotes a mounting ring, which is formed by annularly projecting the outer peripheral portion of the spindle mounting portion 12 toward the tap mounting portion 16 side. Therefore, a void 14 is formed inside the mounting ring 13. Reference numeral 15 is a guide hole, which is provided coaxially with the rotation axis of the main shaft 31.

Reference numeral 17 denotes a tap mounting hole of the tap mounting portion 16, which is provided coaxially with the rotating shaft of the main shaft 31, and the tap 32 fitted in the tap mounting hole 17 is detachably fixed by a set screw 18. . Reference numeral 19 denotes a slide rod, which is provided so as to project toward the spindle mounting portion 12 side and is slidably fitted into the guide hole 15.

Reference numeral 20 denotes an annular leaf spring, which is attached to the outer circumference of the slide rod 19, and the outer peripheral portion thereof is fixed to the end surface of the attachment ring 13 on the tap mounting portion 16 side with a fixing bolt 21. The inner peripheral portion is fixed to the end surface of the tap mounting portion 16 on the spindle mounting portion 12 side with a fixing bolt 22.

In the embodiment, the inner diameter of the mounting ring 13 is made larger than the outer diameter of the tap mounting portion 16 to provide the gap 14 so that the fixing bolt 22 does not interfere with other members when the slide rod 19 slides. is doing. However, if the difference between the movement amount of the main shaft 31 and the self-propelled amount of the tap 32 can be absorbed by the deflection of the leaf spring 20 caused by the sliding of the tap mounting portion 16, the leaf spring 20 may be formed into an annular shape. hand,
Two mounting parts 12 with three or more rectangular leaf springs,
It is also possible to connect 16 together. Further, the guide hole 15 may be provided in the tap mounting portion 16 and the slide rod 19 may be provided in the spindle mounting portion 12.

In FIG. 1, an arrow a indicates the moving direction of the main shaft 31, an arrow b indicates the self-propelled direction of the tap 32, and an arrow c indicates the sliding direction of the tap mounting portion 16.

[0013]

The difference between the movement amount of the main shaft and the self-propelled amount of the tap can be absorbed by the deflection of the leaf spring, so that there is no fear of tap missing or tap breakage due to servo delay, and synchronization.
It can also be used for machine tools that do not have a built-in ridged mechanism.

Further, since the rotation torque of the main shaft is directly transmitted to the tap mounting portion, there is no time lag when the main shaft moves from normal rotation to reverse rotation, and an accurate tap depth can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a tap holder according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a vertical sectional view of a conventional tap holder.

[Explanation of symbols]

 11 Tap Holder 12 Spindle Mounting Part 15 Guide Hole 16 Tap Mounting Part 19 Slide Rod 20 Leaf Spring 31 Spindle 32 Tap

Claims (3)

[Claims] 1. A spindle mounting portion that is attached to and detached from a spindle of a machine tool with an N / C device, and a tap mounting portion that attaches and detaches a tap. The spindle mounting portion and the tap mounting portion are connected via a leaf spring. In addition, the tap mounting part is a tap holder that is connected to the main shaft mounting part so as to be slidable in the rotation axis direction of the main shaft. 2. The tap holder according to claim 1, wherein the leaf spring is formed in an annular shape, the outer peripheral portion is fixed to the spindle mounting portion, and the inner peripheral portion is fixed to the tap mounting portion. 3. The tap holder according to claim 1, wherein the spindle mounting portion is provided with a guide hole, and the tap mounting portion is provided with a projection of a slide rod slidably fitted in the guide hole. .