JP2612506B2 - Lathe with sub spindle - Google Patents

Description

The present invention relates to a blade having a sub-spindle coaxial with a main spindle and capable of moving back and forth in the axial direction and movable in a direction parallel to and perpendicular to the moving direction. The present invention relates to a lathe with a sub-spindle having a base and capable of selecting a chuck work and a center work.

(B) Conventional technology As a lathe with a sub-spindle capable of selecting a chuck work and a center work, conventionally, as shown in FIG. 4, a sub-spindle 3 having a chuck 6 and a center 7 at a point symmetrical position of the sub-spindle 3 are shown. The tailstock 5 'provided is inverted by 180 degrees so that the chuck 6 and the center 7 can be selectively used, and as described in JP-A-2-9501, a chuck and a chuck are provided at the tip of each spindle. There is a type in which a center that can protrude and retract from a through hole formed at the center of the convergence operation of the chuck is used properly.

Also, as a structure where the center is located at the center of the chuck,
For example, an automatic chuck described in Japanese Patent Publication No. 45-16307 is known.

(C) Problems to be Solved by the Invention The type in which the sub-spindle having the chuck and the tailstock having the center can be selectively used by repositioning not only requires complicated position adjustment for each repositioning, It is difficult to ensure high centering accuracy.

On the other hand, the type in which the chuck and the center which can be protruded and retracted from the through hole formed at the center of the convergence operation of the chuck can be said to have high centering accuracy.

However, a slight deviation occurs at the tip of the center whose base end is supported by the tailstock, so that the machining accuracy of the center work is inferior.

In this regard, since the automatic chuck is not intended for the center work, there is no problem.

D. Means for Solving the Problems The present invention relates to a lathe with a sub-spindle that has improved processing accuracy of a center work, and the configuration is such that a chuck and a chuck are provided on at least one end of a main spindle or a sub-spindle. And a center whose tip can be forcibly protruded and retracted from a through-hole formed at the center of the convergence operation of the center. The inner peripheral surface of the through hole of the chuck has a reverse taper that expands inward to correspond to the tapered surface of the center.

E. Working of the chuck work is possible by immersing the center in the chuck, and working of the center work is possible by projecting the center from the center of the chuck.

And when the center is projected from the center of the chuck,
The reverse taper of the center fits into the tapered surface formed on the inner periphery of the through hole formed in the chuck, and the tip of the center is securely positioned at the center of the chuck.

F Examples An embodiment of a lathe with a sub-spindle according to the present invention will be described with reference to the drawings.

1 is a main spindle fixed to the headstock 2 and 3 is a sub-spindle provided coaxially with the main spindle 1 so as to be able to advance and retreat, and are disposed with their tips facing each other. A tool rest 4 that is movable in a direction parallel to and perpendicular to the direction of movement of the spindle 3 is provided.

The sub-spindle 3 is provided on a tailstock 5 driven forward and backward by a feed screw 5b rotated by a motor 5a. A chuck 6 is provided at a tip, and opening and closing operation of the chuck 6 is performed by a cylinder 6a provided at a rear end. Is performed, and is rotated by a motor 6b built in the tailstock 5.

A center shaft 7a extends through the through hole 3a provided at the center of the sub spindle, and the cylinder 7b provided at the rearmost end forcibly moves in and out of the through hole 3a.

A through hole 8 is formed at the center of convergence of the chuck 6 so that the tip of the center shaft 7a protrudes and retracts, and the inside of the through hole 8 is a reverse tapered surface that expands inward.

On the other hand, the tip of the center shaft 7a is a pointed center 7, and when the center 7 projects, the peripheral surface of the center shaft portion penetrating into the through hole 8
It is processed into a tapered surface corresponding to the inner tapered surface of
As a result, when the center shaft 7a protrudes, the tapered portion 9 is fitted into the through hole 8 and accurately positioned.

Therefore, if the accuracy of assembling the chuck is high, the center of the tip of the center shaft is securely positioned at the center.
By forcibly advancing the center shaft 7a by the cylinder 7b and projecting the center 7 from the center of the chuck 6 to the front surface,
The work W is supported at the tip of the center, and becomes a center work processing machine.

Also, by retracting the center shaft 7a and immersing the center 7 from the center of the chuck 6, the workpiece W
, And chuck work can be performed.

Thus, not only the chuck work of the sub-spindle but also the processing of the shaft end by the center work can be performed.

The lathe with a sub-spindle of the embodiment has a structure in which the main spindle 1 can use the chuck 6 and the center 7 as well as the sub-spindle 3.

The main spindle 1 has the same structure as the sub-spindle except that the headstock 2 does not move forward and backward. Therefore, a duplicate description will be omitted. However, since both the main and sub-spindles can be used separately for the chuck and the center, various types of spindles can be used. Can handle processing.

G Effect According to the present invention, since the chuck and the center are provided on the basis of the same axis, there is no deviation between the chuck work processing and the center work processing. The centering effect is extremely high because the taper forming portion fits into the reverse taper portion at the center of the chuck to position the center.

[Brief description of the drawings]

1 is a front view of a lathe with a sub-spindle according to the present invention, FIG. 2 is an explanatory view of performing center work with the lathe with the sub-spindle, and FIG. 3 is an explanatory view of performing chuck work with the lathe with the sub-spindle. FIG. 4 is an explanatory view of a conventional example. 1 ... main spindle, 2 ... headstock, 3 ... sub-spindle, 4 ... tool post, 5 5 '... tailstock, 5a ...
... Motor, 5b ... Feed screw, 6 ... Chuck, 6a ... Cylinder, 6b ... Motor, 7 ... Center, 7a ... Center shaft, 7b ... Cylinder, 8 ... Through hole, 9 ... Taper Forming part, W ... Work.

Claims (1)

(57) [Claims] A lathe with a sub-spindle having a sub-spindle coaxially with a main spindle and capable of moving back and forth in an axial direction thereof and having a tool rest movable in a direction parallel and perpendicular to the moving direction of the main spindle. At least one of the ends of the sub-spindle is provided with a chuck and a center capable of forcibly extending and retracting the end from a through hole formed at the center of the convergence operation of the chuck. A sub-spindle which is tapered so as to have a frusto-conical shape, and is provided with a reverse taper which expands inward on the inner peripheral surface of the through hole of the chuck so as to correspond to the tapered surface of the center. With lathe.