JPH05337702A - Tool post clamping device in lathe - Google Patents

Abstract

PURPOSE:To provide a lathe which is able to position a tool post, being shiftable in a Y-axis direction and secure it to a column in a state of being less in any lost motion and hold any effect due to thermal displacement down to the minimum and usable in even in high precision cutting in addition to heavy-duty cutting. CONSTITUTION:In a lathe which is provided with a chuck 4 holding a work in a main spindle 3, and also provided with a tool post 5 free of movements in three axial directions of X, Z and Y axes orthogonal with one another, a tool post clamping device is provided with a retractable reference block 20, admitting in a lower part of the tool post 5 and holding this tool post 5 after positioning it to a turning position, a pressurizing means 23 pressing this tool post 5 to the reference block 20 and clamping it, and other pressurizing means 24, 26 pressing a sliding part of the tool post 5 to a guide way of the column 9 and clamping it, all in this column 9 supporting the tool post 5 free of movements in the Y-axis direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lathe in which a tool rest on which a tool is mounted is provided so as to be movable in three axial directions of X axis, Z axis and Y axis which are orthogonal to each other.
The present invention relates to a tool post clamping device that positions the tool post and fixes the Y-axis direction when milling without using a shaft.

[0002]

2. Description of the Related Art Conventionally, as a clamping device for positioning a tool post at a turning position and fixing the Y-axis direction when turning a work using a composite working lathe of this type, for example, Japanese Patent Laid-Open No. 63-191529. Japanese Patent Laid-Open Publication No. 2003-242242 proposes a tool post clamping device for fixing the tool post in the Y-axis direction by utilizing a positioning pin or frictional force.

[0003]

However, the tool post clamp device using the positioning pin or the frictional force as described above has a poor rigidity, and there is rattling in the positioning clamp by the pin, and the positioning using the frictional force. In the clamp, if the ball screw or column that drives the tool post in the Y-axis direction is thermally displaced, the center heights of the tool installed on the tool post and the work installed on the spindle will shift, and not only will the machining dimensions go wrong. However, there is also a problem that chattering occurs during machining, which is not suitable for high precision machining or heavy cutting.

Even when the Y-axis direction is a sliding guide, a similar problem occurs due to the play provided in the sliding portion.

The present invention solves the above-mentioned problems, in which the tool post positioned at the turning position can be fixed to the column without rattling, and the effects of thermal displacement of the column and ball screw are minimized. It is an object of the present invention to provide a lathe suitable for high precision machining and heavy cutting.

[0006]

In order to achieve the above object, the tool post clamping device of the present invention is arranged below the tool post in a column in which the tool post is supported so as to be movable in the Y-axis direction. Further, it is provided with a forward / backwardly movable reference block for positioning and carrying this at a turning position, and a pressing means for pressing and fixing the tool rest on the reference block. Further, it is preferable to provide a pressing means for pressing and fixing the sliding portion of the tool rest against the guide surface of the column.

[0007]

With the above structure, the tool rest is completely fixed to the column while being positioned and carried at the turning position by the reference block.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

The drawings show the essential parts of a combined machining lathe equipped with a tool rest clamp device according to the present invention.

A headstock 2 is fixed to a bed 1, a chuck 4 for holding a work W is attached to a main spindle 3, and a work held by the chuck 4 by a main spindle motor (not shown) built in the headstock 2. It is designed to rotate W.

The tool rest 5 has a turret 6 for mounting a tool 7, and is provided on a bed 1 via a saddle 8 and a column 9 so as to be movable in three mutually orthogonal X-axis, Z-axis and Y-axis directions. Has been. The outer peripheral surface of the turret 6 projects in the X-axis direction from the front surface of the column 9 in order to avoid interference with the work W. The saddle 8 is movably arranged in the Z-axis direction via rails 10 and 10 provided in the bed 1 and extending in the Z-axis direction, and the feed screw 11 is rotatably driven by the Z-axis motor 12 to the rails 10 and 10. It is designed to be moved along. The column 9 is movably arranged in the X-axis direction via rails 13 and 13 provided on the saddle 8 and extending in the X-axis direction. The feed screw 14 is rotatably driven by an X-axis motor 15 and the rails 13 and 13 are provided. It is designed to be moved along.

The tool rest 5 is slidably in contact with a guide body 16 fixedly provided on the headstock side of the column 9 and guide surfaces 9a and 9b so as to be movable in the vertical direction, that is, in the Y-axis direction, as shown in FIG. As described above, the feed screw 17 is rotationally driven by the Y-axis motor 18 mounted on the column 9 via the transmission pulley mechanism 19 and moved in the Y-axis direction.

A reference block 20 is provided below the column 9 for positioning and carrying the tool rest 5 when performing turning and milling without using the Y-axis. The reference block 20 is connected to a piston rod 22 of a moving cylinder 21 fixed to the bottom 9c of the column 9,
It is movable forward and backward along the bottom portion 9c, and when the Y axis is used, it is in the retracted position so as not to hinder the movement of the tool rest 5 in the Y axis direction. Thus, when the tool rest 5 is positioned at a predetermined position in the Y-axis direction, it moves to the forward position to carry the tool rest 5 as shown in FIG. Further, a clap cylinder 23 for pressing the tool rest 5 in the Y-axis direction is provided at the top of the column 9. Further, the column 9 has two clamp cylinders 2 for pressing the tool rest 5 in the Z-axis direction.
4, 24 are assembled. The clamp cylinder 2
The piston rod 24a of No. 4 comes into contact with and presses the projecting pieces 25 provided on both sides of the rear part of the tool rest 5. Further, when the column 9 is provided with the clamp cylinder 26 that presses the tool rest 5 in the X-axis direction, the tool rest 5 is clamped more reliably (see FIGS. 1 and 2).

The combined machining lathe constructed as described above is
As shown in FIG. 3, with the reference block 20 standing by in the retracted position and the clamp cylinder 23 returned to the retracted position, the tool rest 5 is appropriately moved in the three axis directions of the X axis, Z axis, and Y axis. The work W is subjected to predetermined processing by a rotary tool 7'such as a drill, an end mill or the like.

On the other hand, when performing turning, the tool rest 5 is positioned at the turning position and fixed in the Y-axis direction. Here, the turning position is a position where the Y coordinate value of the cutting edge of the tool 7 mounted on the tool rest 5 is zero, with the center of rotation of the spindle 3 as the origin. In the case of the rotary tool 7 ', the Y coordinate of the rotation axis is at the position of zero.

Next, the procedure for positioning the tool rest 5 at the turning position and fixing it in the Y-axis direction will be described.

When the Y-axis clamp command is issued while the tool rest 5 is located above the turning position, the moving cylinder 21 first operates to move the reference block 20 to the forward position shown in FIG. Then, the Y-axis motor 18 is driven to lower the tool rest 5 and provisionally position the tool block 5 at a position close to about several mm above the reference block 20. In this state, the Y-axis motor 18 is turned off. In this way, the Y-axis motor 18 is turned off before the tool rest 5 contacts the reference block 20.
The reason why it is set to F is that if the tool rest 5 is brought into direct contact with the reference block 20, the ball screw 17 may be damaged. Therefore, at the same time when the tool rest 5 is pressed against the reference block 20 by the next clamp cylinder 23. , The ball screw is allowed to rotate freely.

Next, the clamp cylinder 23 is actuated to push down the tool rest 5 with its piston rod 23a and press it against the reference block 20 to position it at the turning position. At the same time, the piston rod 23a and the reference block 20 move the tool rest 5 into position. It clamps and fixes the Y-axis direction. Subsequently, the clamp cylinders 24, 24 are actuated, and the piston rod 24
a, 24a presses the projecting pieces 25, 25 in the Z-axis direction and further presses the clamp cylinders 26, 26 in the X-axis direction to move the tool rest 5 into the guide surfaces 9a and 9a of the column 9.
Press on b. As a result, the tool rest 5 is completely fixed to the column 9. In this state, the tool rest 5 is appropriately moved in the biaxial directions of the X axis and the Z axis to perform turning.

In the fixing procedure in the Y-axis direction described above, the feed of the tool rest 5 is temporarily stopped a few mm above the reference block 20, and then the tool rest 20 is finely moved until it comes into contact with the reference block 20, while the tool A contact detecting means for detecting the contact between the base and the reference block is provided, and the contact detecting means detects the contact, or the NC control device detects the excessive positional deviation between the command value and the position detected value. In response to this, the feed of the tool rest 5 may be stopped.

As the contact detection means, the reference block 20 is used.
An electric detector such as a proximity switch or a pressure detector using compressed air is provided on either the side or the tool rest 5 side.

When the tool rest 5 and the reference block 20 come into contact with each other, an air blowout port for air blowing is provided in the lower part of the tool rest 5 in order to prevent positional deviation due to biting of dust such as chips. Is preferred.

[0022]

As described above, according to the present invention,
The turret is fixed to the column while being positioned and carried in the Y-axis direction by the reference block provided in the lower part of the column, which is less affected by thermal displacement, so there is no rattling and the heat of the column, ball screw, etc. The effect of displacement can be minimized. Therefore, chattering does not occur during turning, and there is no fear that the center heights of the tool and the work will be misaligned, so that a lathe suitable for high precision machining and heavy cutting can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view of essential parts of a combined machining lathe provided with a tool post clamp device according to the present invention.

FIG. 2 is a vertical sectional front view of the relevant part showing a turning state in which the Y-axis direction is clamped.

FIG. 3 is a vertical sectional front view of the relevant part showing a state where the Y-axis direction is unclamped.

[Explanation of symbols]

 1 Bed 2 Spindle Headstock 3 Spindle 4 Chuck 5 Turret 7 Tool 8 Saddle 9 Column 20 Reference Block 21 Moving Cylinder 23 Clamp Cylinder 24 Clamp Cylinder 26 Clamp Cylinder

Claims (2)

[Claims] 1. A chuck for holding a work is provided on a main shaft, and a tool rest for mounting a tool has X-axes orthogonal to each other,
In a lathe provided so as to be movable in three axis directions of a Z axis and a Y axis, a column in which the tool rest is supported so as to be movable in the Y axis direction enters below the tool rest and turns the tool rest. A tool post clamping device in a lathe, comprising: a reference block that is positioned and held in a position and is capable of advancing and retreating; and pressurizing means that presses and fixes the tool post to the reference block. 2. The tool post clamping device for a lathe according to claim 1, further comprising a pressurizing means for pressing and fixing the sliding portion of the tool post against the guide surface of the column.