JPH03111149A - Indexing device - Google Patents

Abstract

PURPOSE:To realize a high speed indexing at a low price and make damage minimum at the time of a tool rest being delivered with excessive force while the rigidity of the tool rest is being maintained. CONSTITUTION:When a tool rest indexing position command A is inputted into a control means 13, a press-contact release signal E is sent to a press- contact means 15, and a movable portion 3 and a fixed portion 5 at the tool rest are separated, and an electric current C is sent to a motor 9, and the movable portion 3 is rotated, and a rotation position signal D is sent to the control means 13 from a rotation position detector 11. After the completion of indexing, an indexing position command F is sent to an indexing means 14 and the indexing is made precisely at a high speed, and after the completion of indexing, a press-contact signal E is sent to the press-contact means 15 from the control means 13, and the movable portion 3 and the fixed portion 5 are press-contacted and fixing is made by means of the frictional force. The indexing means 14 is separated from the movable portion 3 during fixing, and when excessive force is delivered to the tool rest, the movable portion 3 slides and impact is softened.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an indexing device for a tool rest of a machine tool, particularly a numerically controlled (NG) lathe.

(Prior art) Fig. 2 is a schematic perspective view showing an example of an NG lathe;
The figure is a plan view thereof. A workpiece 8 is gripped by a chuck 2 connected to the main shaft of a lathe body 1, and a tool (blade) 4 is mounted on a movable part (rotating part) 3 of a tool rest. The movable part 3 and the fixed part 5 of the tool post are freely controlled in position in the X direction and the Z direction by a zapo dryer, and the workpiece 8 held by the chuck 2 is a tool attached to the movable part 3 of the tool post. 4, it can be processed into any shape.

FIG. 4 shows a schematic structural diagram of a conventional indexing device for a tool rest of an NG lathe having such a configuration. One end surface of a curvic gear 7 is fixed to the fixed part 5 of the tool rest. A trapezoidal uneven portion is formed on the other end surface of the curvic gear 7, and the curvic gear 7 is clamped/unclamped (fixed 7 minute 1II). A gear lO and a rotational position detector 11 are mounted on the rotation shaft 16 of the movable part 3 of the tool post.
are coupled to each other, and further connected to a drive motor 9 via a gear 10. The indexing position command A of the tool rest is the control means 1
2, an unclamping signal B is sent to the clamping means 6, and the movable part 3 of the tool post and the locking gear 7 are unclamped. Then, the drive current C is sent to the drive morph 9, the movable part 3 of the tool post is rotationally driven, and the current rotational position No. 18 is sent from the rotational position detector 11 to the control means 12. After the adjustment of the tool post is completed, the Franz signal B is sent from the control means 12 to the clamping means 6, so that the movable part 3 of the tool post and the curvic gear 7 are clamped.

(Problems to be Solved by the Invention) In the conventional indexing device described above, the lift amount of the clamp/amplamp operation between the movable part of the tool post and the curvic gear is large, and the clamping means is large in size and heavy. There was a limit to speeding up indexing. Furthermore, the curvic gear is expensive because it has a multi-millimeter high precision shape, and has the drawback of increasing the price of the indexing device itself.

In addition, in order to maintain high rigidity of the tool post, the movable part of the tool post and the curvic gear are clamped very firmly, but for this reason, for example, the tool post and chuck may be clamped together due to problems such as failure of the NG lathe or incorrect operation. There was a problem in that the damage caused in the event of a collision would be severe. One way to solve this problem is to create a weak part in the turret so that when excessive force is applied to the turret, only that weak part breaks. However, since the parts with weak strength are usually made of metal materials such as iron, their rupture is shown in the force (F)-displacement (E) characteristic diagram in Figure 5.
J: Uni bullet +1 deformation, reached after undergoing plastic deformation.

Therefore, the rigidity in the elastic deformation region becomes smaller,
It is not possible to maintain high rigidity of the turret. On the other hand, if the rigidity in the elastic deformation region is increased, the force at the breaking point also increases, so even when excessive force is applied to the tool post, no breakage occurs, resulting in greater damage.

The present invention was made in view of the above-mentioned circumstances, and
The purpose of the present invention is to enable high-speed indexing of the turret, to be inexpensive, and to maintain high rigidity of the turret while minimizing damage even when excessive force is applied to the turret. An object of the present invention is to provide an indexing device that can be suppressed.

(Means for Solving the Problem) The present invention fixes the movable part and the fixed part of a tool rest of a machine tool to execute machining, and performs indexing by dividing the movable part and the fixed part. The invention relates to an indexing device, and the above object of the present invention is to press the movable part and the fixed part,
This is achieved by providing pressure contact means that performs the fixing using the frictional force, releases the pressure contact, and performs the feeding.

(Function) The indexing device of the present invention fixes the movable part and the fixed part of the tool post using frictional force due to pressure contact, and the high rigidity of the tool post can be obtained during normal cutting, resulting in high-precision machining. This makes it possible for the friction part to slide and soften the impact when excessive force is applied to the turret.

(Example)

Claims (1)

[Scope of Claims] 1. An indexing device that performs machining by fixing a movable part and a fixed part of a tool post of a machine tool, and performs indexing by separating the movable part and the fixed part, Pressing the movable part and the fixed part, and performing the fixing by the frictional force,
An indexing device characterized by comprising pressure contact means for releasing the pressure contact and performing the separation. 2. The indexing device according to claim 1, wherein the pressure contact means is a piezoelectric element. 3. The indexing device according to claim 1, further comprising indexing means for performing indexing with higher precision and higher speed after the indexing is completed. 4. Claim 3, wherein the indexing means is separated from the movable part while the movable part and the fixed part are fixed.
The indexing device described in . 5. Claim 1, further comprising a control means for inputting an indexing position command and detecting an actual indexing position, determining a difference between the indexing position command and the actual indexing position, and outputting the difference between the indexing position command and the actual indexing position. Indexing device as described. 6. When the difference between the index position command and the actual index position is larger than a predetermined amount, the control means sends a pressure release signal to the pressure contact means and outputs an abnormality signal to the outside. The indexing device according to item 5.