JPH077047Y2 - Tailstock with tailstock - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a hydraulic tailstock capable of gripping the inner diameter or outer diameter of the tailstock side of a workpiece.

2. Description of the Related Art In some cases, a collet chuck is preferable in terms of workability and accuracy rather than using a center that supports the tailstock side of a workpiece gripped by a spindle chuck. In such a case, a collet chuck is attached to the tip of the tailstock shaft of the hydraulic tailstock, but a rotary hydraulic cylinder is also provided for opening and closing the collet chuck.

Problems to be solved by the invention When a rotary cylinder, which is a conventional technology like this, is installed side by side, the tailstock becomes large in size, the number of drive cylinders increases, the number of control devices increases, and the structure becomes complicated. Moreover, it has a problem that it becomes expensive. The present invention has been made in view of the above problems of the prior art, and an object thereof is to provide a collet type tailstock having a simple structure without particularly providing a collet chuck driving device. To do.

Means for Solving the Problems A collet chuck is provided at the front end of a mandrel of a hydraulic tailstock, a working rod of the collet chuck is projected rearward, and a stopper is adjustably provided on the projecting portion.

Action When pressure oil is sent to the hydraulic cylinder, the tailstock shaft moves forward, and when the collet chuck reaches the workpiece gripping position, the stopper stops the advancement of the working rod, and the tailstock shaft continues to move forward to open the collet (or Collet expansion (closed),
The inner diameter of the workpiece is grasped by the reduction.

Example An example will be described with reference to FIG. A well-known hydraulic tailstock 1 of a lathe is fitted with a tailstock shaft 2 slidably in an axial direction, and a hydraulic cylinder 3 whose rear end is provided on a tailstock 7.
It is connected to the piston rod 5 of the piston 4 fitted in the. A rotary center member 7 is concentrically rotatably supported by bearings 6 at the tip of the tailstock shaft 2. The rotation center member 7 has a through hole 7a formed in the center thereof so that a spring 11 can be built therein, and one tapered portion 9a for opening a collet 8 at the tip thereof.
A chuck mounting body 9 having a center hole and having a center hole is concentrically fastened to the rotation center member. An action rod 10 having a taper portion 10a in the opposite direction corresponding to the taper portion 9a of the chuck mounting body 9 on the head penetrates the chuck mounting body 9, the rotation center member 7, the tailstock shaft 2, the piston rod 5, and the piston 4. And then project backwards. The action rod 10 has a flange 10b fixed in a spring built-in hole of the rotation center member 7 and is always acted by the built-in spring 11 in a direction to close the collet 8.

A screw is engraved at the rear end of the operating rod 10, and an adjusting cylinder 12 is screwed so that the position can be adjusted in the axial direction. A disk-shaped stopper 14 is rotatably supported by the adjusting cylinder 12 via a bearing 13, and the stopper is guided by a guide rod 15 axially implanted at the rear end of the hydraulic cylinder 3 so as not to rotate. .

When the hollow workpiece W that needs to be gripped on the tailstock side is determined, the collet 8 is replaced with a suitable one, the tailstock 1 is placed at a grippable position, and the adjusting cylinder 12 of the stopper 14 is moved forward and backward to move the collet 8 exactly. Hydraulic cylinder 3 at the position where it enters the mouth of the workpiece W
The tailstock 1 is fixed and adjusted so as to come into contact with the rear end of the tailstock. After the transported work W is gripped by the spindle chuck, pressure oil is sent to the rear chamber of the hydraulic cylinder 3 to move the piston 4 forward and the piston rod 5 to move the tailstock shaft 2 forward. The stopper 14 adjusted at the position where the collet 8 enters the mouth of the workpiece W comes into contact with the rear end surface of the hydraulic cylinder 3, so that the working rod 10 is prevented from moving forward. Since the forward force acts on the tailstock shaft 10, the tapered portion 9a of the collet mounting body 9 clamps the collet 8 with the tapered portion 10a of the head of the working rod 10, and the tightening taper expands the collet 8. , Hold the inner diameter of the workpiece W firmly. When the main shaft is rotated, the workpiece W is rotated together with the rotatable center member 7. Along with this, the operating rod 10 is also rotated together with the adjusting cylinder 12 by the bearing 13 without any trouble. The gripping force of the collet is appropriately adjusted by the thrust of the hydraulic cylinder.

In FIG. 2 of the outer diameter grip, a collet portion different from that in FIG. 1 will be described. A cup-shaped chuck mounting body 21 having a tapered hole 21a is concentrically fastened to the front end of the rotation center member 7, and a collet 22 having a tapered portion 22a is inserted therein, and the collet 22 operates. It is screwed to the tip of the rod 10. And the action rod is pushed by the spring 11, and the collet is constantly
22 is left open.

When the workpiece W is determined, the hole of the collet 22 is replaced with one that matches the outer diameter of the workpiece W, and the same position adjustment is performed. When the stopper 14 comes into contact with the rear end face of the hydraulic cylinder due to the forward movement of the tailstock shaft 2, the working rod 10 retracts the collet 22, so that the collet 22 is reduced in diameter by the taper hole 21a of the collet mounting body 21 and grips the workpiece W. Is.

Effect As described in detail above, in the present invention, the forward movement of the tailstock prevents the movement of the working rod of the collet at a predetermined position, and the thrust of the tailstock expands and contracts the collet. Since it is not necessary to provide it in the above, the structure is simplified, the cost is reduced, and the control is easy.

[Brief description of drawings]

FIG. 1 is an explanatory sectional view of a tailstock of the present invention for gripping an inner diameter,
The figure is an explanatory cross-sectional view showing a collet portion for gripping an outer diameter. 1 …… tailstock, 2 …… tailstock shaft 3 …… hydraulic cylinder, 7 …… rotation center part 8,22 …… collet 9,21 …… collet mount 10 …… action rod, 14 …… stopper

Claims (1)

[Scope of utility model registration request] 1. In a hydraulic tailstock, a collet chuck is rotatably provided at a front end of a tailstock shaft, a collet working rod of the collet chuck is extended to the rear of the tailstock, and acts on a protruding portion of the working rod. A collet chuck characterized in that a stopper that regulates the rod advance position is provided so that the position can be adjusted, and that the stopper acts when the collet advances to the gripping position of the workpiece, and the collet operates with the subsequent advance of the tailstock shaft. Tailstock.