JPH0435801A - Lathe equipped with subspindle - Google Patents

Abstract

PURPOSE:To carry out not only the chuck work working but center work working by installing a chuck and a center whose top edge can be appeared and disappeared from the center of the chuck, taper-working the part close to the projection part of a center shaft and forming the inner peripheral surface at the convergence operation center of the chuck into an inverted taper spreading inward. CONSTITUTION:A center shaft 7a is penetrated at a through hole 3a formed at the center of a subspindle, and advance-retreat-moved in the through hole 3a by a cylinder 7b. Further, at the convergence center of a chuck 6, a through hole 8 having an inverted surface is formed. Since, when a center 7 projects, the peripheral surface of the center shaft part which penetrates through the inside of the through hole 8 is worked into a tapered surface at the top edge of the center shaft 7a, the center shaft 7a is correctly positioned in projection. Accordingly, the shaft edge part can be worked not only through the chuck work working but the center work working.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention provides a cutting tool that is provided with a sub-spindle that is coaxial with a main spindle and that is movable in the axial direction of the main spindle, and that is movable in parallel and perpendicular to the direction of the main spindle. This invention relates to a lathe with a sub-spindle having a stand.

口 Prior Art The above-mentioned lathe with a sub-spindle is equipped with a chuck at the tip of the sub-spindle, and is intended for chuck work machining. Also, in the past, as shown in the fourth diagram,
A sub-spindle 3 having a chuck 6, and a tailstock 5' having a center 7 at a point symmetrical position of the sub-spindle 3.
There is also a proposal for a device that allows the chuck 6 and center 7 to be used separately by inverting the chuck 6 by 180 degrees.C Problems to be Solved by the Invention In machining chuck workpieces, machining of the shaft end cannot be expected.
On the other hand, a system in which a sub-spindle with a chuck and a tailstock with a center can be used by changing the position requires complicated position adjustment each time the position is changed, and also requires high centering accuracy. 2. Means for Solving the Problems The present invention is a lathe with a sub-spindle that enables not only chuck work machining but also center work machining. At least one tip of the sub-spindle is provided with a chuck and a center whose tip can protrude and retract from the center of the chuck, and when the center protrudes, the center shaft is tapered so as to have a truncated conical shape. In addition, the inner circumferential surface of the center of the convergence operation of the chuck is provided with a reverse taper that expands inward to correspond to the tapered surface of the center shaft.

E. If the action center is recessed from the center of the chuck, chuck work machining is possible, and if the center is protruded from the center of the chuck, center work machining is possible.

EXAMPLE An example of a lathe with a sub-spindle according to the present invention will be described based on the drawings.

Reference numeral 1 indicates a main spindle fixed to a headstock 2, and reference numeral 3 indicates a sub-spindle that is movable back and forth on the same axis as the main spindle 1.The sub-spindles are disposed with their tips facing each other, and a sub-spindle is provided between the two. A tool post 4 is provided that is movable in a direction parallel to and perpendicular to the direction of movement of the spindle 3. The sub-spindle 3 is provided on a tailstock 5 that is driven forward and backward by a feed screw 5b rotated by a motor 5a, and is equipped with a chuck 6 at its tip, and the chuck 6 is opened and closed by a cylinder 6a provided at its rear end. At the same time, the motor 6b built into the tailstock 5
rotated by A center shaft 7a is inserted through a through hole 3a provided at the center of the sub-spindle, and is moved forward and backward within the through hole 3a by a cylinder 7b provided at the rearmost end. In addition, a through hole 8 is formed at the convergence center of the chuck 6, through which the tip of the center shaft 7a enters and retracts.
The inside of the through hole 8 has an inverted tapered surface that expands inward. On the other hand, the tip of the center shaft 7a has a pointed center 7, and when the center 7 protrudes, the peripheral surface of the center shaft portion penetrating into the through hole 8 The tapered surface is machined to correspond to the inner tapered surface of the center shaft 7a, so that when the center shaft 7a is projected, the taper forming portion 9 fits into the through hole 8, and the center shaft 7a is accurately positioned.

The sub-spindle 3 formed in this way is connected to the cylinder 7
By moving the center shaft 7a forward through b and causing the center 7 to protrude from the center of the chuck 6 to the front, the workpiece W can be supported at the center, resulting in a center work processing machine. Further, by retracting the center shaft 7a and recessing it from the center of the chuck 6 into the center 7, it is possible to hold the work W by the chuck 6 and perform chuck work machining. This allows not only chuck work machining inherent to the sub-spindle, but also machining of the shaft end by center work machining. Further, the lathe with a sub-spindle of the embodiment has a structure in which the main spindle 1 as well as the sub-spindle 3 can be used as a chuck 6 or a center 7. The main spindle 1 has the same structure as the sub-spindle except that the headstock 2 does not move forward or backward, so a duplicate explanation will be omitted, but since both the main and sub spindles can be used for chuck and center, various Can be processed.

G. Effect According to the present invention, since the chuck and the center are provided based on the same axis, there is no misalignment between the chuck work machining and the center work machining, and furthermore, the protrusion on the center axis The tapered part of the chuck fits into the inverted tapered part at the center of the chuck, and the center position is determined with high precision. In addition, since center work machining allows machining of both ends, a machining method can be adopted depending on the object to be machined, and is highly user-friendly.

[Brief explanation of the drawing]

Fig. 1 is a front view of a lathe with a sub-spindle according to the present invention, Fig. 2 is an explanatory diagram showing center work processing performed using the same lathe with a bus spindle, and Fig. 3 shows chuck work processing performed using the same lathe with a bus spindle. FIG. 4 is an explanatory diagram of a conventional example. l... Main spindle, 2... Headstock, 3... Sub-spindle, 4... Turret, 5.5'... Tailstock, 5a
...Motor, 5b...Feed screw, 6...Chuck, 6a
・・Cylinder, 6b・・Motor, 7・・Center, 7a・
・Center axis, 7b...Cylinder, 8...Through hole, 9...Taper forming part, W...Work, Patent applicant Okuma Iron Works Co., Ltd. Figure 4 of Figure 13

Claims (1)

[Claims] In a lathe with a sub-spindle, which is provided with a sub-spindle that is coaxial with the main spindle and is movable in the axial direction thereof, and has a tool rest that is movable in a direction parallel to and orthogonal to the direction of movement of the sub-spindle, at least either the main spindle or the sub-spindle. A chuck and a center from which the tip can be retracted from the center of the chuck are provided at one end of the chuck,
The protruding portion of the center shaft is tapered to form a truncated conical shape when the center protrudes, and the inner circumferential surface of the converging operation center of the chuck is inwardly shaped to correspond to the tapered surface of the center shaft. A lathe with a sub-spindle that has a reverse taper that expands to .