JP2000190104A - Lathe turning machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change the edge rigidity of a lathe turning tool following to a machining process. SOLUTION: Two hydraulic cylinders 7, 8 are arranged on a sideways middle stand 2 upper/lower symmetrically for the slide axis of a tool rest 1. The contact shafts 9, 10 to which the piston rods 7a, 8a of the hydraulic cylinders 7, 8 are contacted are fixed to the tool rest 1. The lower slide surface 11 is formed in an arc shape around the upper contact shaft 9. Direction selector valves 14, 15 are installed in a hydraulic circuit 12 so as to control respective hydraulic cylinders 7, 8 separately. The edge rigidity of a lathe turning tool 5 is increased by extending the hydraulic cylinders 7, 8 together and clamping the tool rest 1 to the middle stand 2 at upper/lower two places. The edge rigidity is decreased by extending the upper hydraulic cylinder 7, shrinking the lower hydraulic cylinder 8 and supporting the tool rest 1 turnably for the middle stand 2 around the upper contact shaft 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turning machine such as a lathe or a grinder.

[0002]

2. Description of the Related Art In turning, a process in which the machining accuracy is improved as the rigidity of the cutting edge of a turning tool is higher, and a process in which chatter is generated in a cutting surface if the cutting edge rigidity is too high, such as grooving. There is. For this reason, in the conventional turning machine, the tool post is supported with a certain rigidity with respect to the middle base so that the cutting edge rigidity has an intermediate value that is neither too high nor too low.

[0003]

However, according to the conventional turning machine, since the supporting rigidity of the tool post is always constant, it is impossible to change the cutting edge rigidity of the turning tool according to the machining process. Was.

[0004] Therefore, an object of the present invention is to provide a turning machine capable of changing the cutting edge rigidity of a turning tool in accordance with a machining process.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a turning machine according to the present invention supports a tool rest holding a turning tool on a middle base so as to be slightly rotatable, and a rotation axis of the tool rest. The means for pressing the tool rest against the middle base is provided at one of two positions on both sides of the body, and the fluid pressure cylinder for clamping the tool rest on the middle base is provided at the other side (claim 1).

In this case, in the turning machine according to the present invention, it is preferable that the pressing means is a hydraulic cylinder and a hydraulic circuit for separately controlling the two hydraulic cylinders is provided. Further, the pressing means is disposed above the horizontal middle table, the fluid pressure cylinder is disposed below the horizontal middle table, and the tool rest is provided with a pressing member and a contact member with which the piston rod of the hydraulic pressure cylinder abuts. It is preferable that the lower sliding surface of the pedestal and the tool rest is formed in an arc shape centering on the upper contact member.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a lathe will be described below with reference to the drawings. As shown in FIG. 1, in this lathe, a tool rest 1 is supported by a horizontal middle stand 2 so as to be slidable in the horizontal direction. A turret 3 is rotatably supported on the tool rest 1, and a turning tool 5 such as a cutting tool for turning a work 4 is held on the outer periphery of the turret 3.

[0008] Two hydraulic cylinders 7 and 8 are arranged in the middle base 2 symmetrically with respect to the sliding axis of the tool rest 1.
Two contact shafts 9, 10 are fixed to the tool rest 1 so as to extend in the horizontal direction at positions opposed to the hydraulic cylinders 7, 8. The hydraulic cylinders 7 and 8 are configured so that the tool rest 1 can be clamped to the middle stand 2 with the piston rods 7 a and 8 a abutting on the contact shafts 9 and 10.

The hydraulic circuit 12 of the hydraulic cylinders 7 and 8 includes:
A direction switching valve 14 for switching the operation direction of the upper hydraulic cylinder 7 and a direction switching valve 15 for switching the operation direction of the lower hydraulic cylinder 8 are provided, and the two hydraulic cylinders 7 and 8 are operated by the hydraulic circuit 12. It is controlled separately. As shown in FIG. 2, the lower sliding surface 11 of the tool rest 1 and the middle stand 2 is formed in an arc shape centering on the upper contact shaft 9.

In the lathe having the above configuration, when the tool post 1 is moved and positioned, two hydraulic cylinders 7 and 8 are used.
Are contracted together, and the tool rest 1 is unclamped from the middle stand 2. Also, when turning the work 4 on the outside diameter, as shown in FIG. 1, the two hydraulic cylinders 7 and 8 extend together, and the tips of the piston rods 7a and 8a abut against the contact shafts 9 and 10, The tool rest 1 is clamped to the middle stand 2 at two upper and lower positions.
Accordingly, in this state, the rigidity of the support of the tool rest 1 and the rigidity of the cutting edge of the turning tool 5 can be increased, and the outer diameter and the like of the work 4 can be machined with high accuracy.

On the other hand, at the time of grooving or the like, as shown in FIG. 3, the upper hydraulic cylinder 7 is extended, the lower hydraulic cylinder 8 is contracted, and the tool rest 1 is moved to the middle platform 2 at one upper position.
To be clamped. When the work 4 rotates, the tool rest 1 rotates at a slight angle (θ) about the upper contact shaft 9 by the cutting force (F) acting on the turning tool 5, and the cutting edge of the turning tool 5 Is displaced away from the workpiece 4 (δ indicates the amount of vertical displacement of the cutting edge). In this case, since the lower sliding surface 11 is formed in an arc shape, the tool rest 1 can rotate smoothly. Therefore, at this time, the rigidity of the support of the tool rest 1 and the rigidity of the cutting edge of the turning tool 5 can be reduced, and grooving can be performed with high precision without generating chatter on the cutting surface.

The switching modes of the hydraulic cylinders 7 and 8 are not limited to the above three types, and the switching modes of the respective cylinders 7 and 8 are not limited.
The support rigidity of the tool rest 1 can be changed more variously by adjusting the supply amount of the hydraulic oil to the tool rest 1. Also, the hydraulic cylinder may be installed on the tool post side, an air cylinder may be used instead of the hydraulic cylinder, or the configuration of the above embodiment may be applied to a grinding machine. It is also possible to change the shape and configuration as appropriate.

[0013]

As described above in detail, according to the turning machine of the present invention, since the two fluid pressure cylinders for clamping the tool post are separately controlled, the cutting edge rigidity of the turning tool can be reduced. It has an excellent effect that it can be changed according to the processing step.

[Brief description of the drawings]

FIG. 1 is an elevational view of a turning machine showing one embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG. 1 showing a shape of a lower sliding surface.

FIG. 3 is an elevational view showing the operation of the turning machine of FIG. 1;

[Explanation of symbols]

1. Tool post, 2. Middle stand, 5. Turning tool, 7, 8.
・ Hydraulic cylinder, 7a, 8a ・ ・ Piston rod, 9,
10 contact shaft, 11 lower sliding surface, 12 hydraulic circuit, 14, 15 directional switching valve.

Claims (3)

[Claims] 1. A means for supporting a tool rest holding a turning tool on a middle base so as to be slightly rotatable, and pressing the tool rest against the middle base in one of two positions on both sides of a rotation axis of the tool base. On the other hand, a turning machine provided with a fluid pressure cylinder that clamps the tool post to the middle stage. 2. The turning machine according to claim 1, wherein the pressing means is a hydraulic cylinder, and a hydraulic circuit for separately controlling the two hydraulic cylinders is provided. 3. The pressing means is disposed above the horizontal middle table, and the hydraulic cylinder is disposed below the horizontal middle table. The tool rest is provided with a contact member with which the pressing means and the piston rod of the hydraulic cylinder respectively contact. The turning machine according to claim 1 or 2, wherein the lower sliding surfaces of the middle mount and the tool rest are formed in an arc shape centering on the upper contact member.