JPH1043906A - Lathe turning method for recessed groove and lathe turning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To turn a recessed groove easily by pressing a cutting tool against a machined face of a workpiece and vibrating the cutting tool in the direction of pressing while transferring the cutting tool in the orthogonal direction to the direction of pressing. SOLUTION: A first travel table 6 and a second travel table 11 are moved to bring a tip of a cutting tool 5 into contact with a machining start point of a workpiece 9. After that, while moving the first travel table 6 at predetermined speed, a drive signal generator 10 is controlled so that an output pulse having shorter cycle than rotation cycle of a main spindle 4 is obtained, and the cutting tool 5 is vibrated in X direction at cycle of one-integral number of the rotation cycle of the main spindle 4, namely, the workpiece 9 for cutting. Consequently, a spiral recessed groove having the width equal to cutting width of the cutting tool 5 is formed on a machined face of the workpiece 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a groove turning method and a turning apparatus for forming one or more grooves on a processing surface of a workpiece, and more particularly to a groove forming method for a fluid bearing device. It is suitable for processing parts that are relatively small and require high precision.

[0002]

2. Description of the Related Art For example, a shaft formed with a groove of a fluid bearing device is required to have a high processing accuracy structurally.
Conventionally, the processing of the groove is generally performed by an etching method. That is, as shown schematically in FIG. 12, when a plurality of grooves extending radially from the center of the disk-shaped workpiece 1 are formed on the processing surface of the disk-shaped workpiece 1, a portion excluding the processing portion 2 forming the groove is formed. After the corrosion-resistant coating 3 is applied, and then immersed in an etching solution to elute and remove the processed portion 2, the corrosion-resistant coating 3 is removed and the processed portion 2 is removed.
A groove is formed in the groove.

[0003]

However, the above-mentioned etching method involves the necessity of equipment, the problem of waste liquid treatment of various treatment liquids, and mechanical cutting such as finishing the outer shape of the workpiece 1 into a disk shape. Since the processing by the etching method is performed in a separate step, there is a problem such as a decrease in concentric accuracy between the center of the processing surface and the centers of a plurality of radially extending grooves.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a turning method and a turning device for a concave groove according to the present invention press a cutting tool against a processing surface of a workpiece to be rotated and driven in a pressing direction. While transferring the cutting tool in a right angle direction,
By vibrating the cutting tool in the pressing direction, a continuous groove is formed on the surface to be processed.

According to the present invention, a groove can be easily formed by a simple improvement of adding a function of vibrating a cutting tool in a pressing direction to a conventional turning machine. Can be performed by the same equipment, and the so-called one chuck can perform the processing for cutting the external shape and the like and the groove processing, and the concentric accuracy between the workpiece and the groove can be stabilized. Also, by changing the vibration cycle of the cutting tool, various types of concave grooves can be easily formed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a plan view schematically showing an embodiment of a groove turning apparatus according to the present invention, and reference numeral 4 denotes a main shaft which is rotationally driven by a drive source (not shown). A workpiece 9 is fixed to the tip of the main shaft 4 via a chuck 8.

Reference numeral 6 denotes a first moving table, which is reversibly movable in the direction of arrow Y by a driving source (not shown). A second moving table 11 that is reversibly movable in the X direction perpendicular to the arrow Y by a driving source (not shown) is mounted on the first moving table 6. A vibration device 12 for vibrating the cutting tool 5 in the X direction is fixed on the table 11.
The vibration device 12 is configured to vibrate the cutting tool 5 in accordance with the cycle of the output pulse of the drive signal generator 10.

Reference numeral 7 denotes the rotational speed of the main shaft 4, the moving directions, distances and speeds of the first and second moving tables 6 and 11,
This is a control device that controls the cycle of the output pulse of the drive signal generator 10 and the like. The vibrating device 12 is removed and the cutting tool 5
Is directly attached to the second moving table 11, the configuration is the same as that of a conventionally known NC turning apparatus.

The operation of the groove turning apparatus thus configured will be described below. For comparison, first the normal NC
The case of using as a turning device will be described.

In this case, the drive signal generator 10 is stopped, and the vibration of the vibration device 12 is stopped.
Is rotated at a predetermined speed, and the workpiece 9 is rotated.
In this state, the first and second moving tables 6, 11
Is moved, the tip of the cutting tool 5 is brought into contact with the processing start point of the workpiece 9, and then the first moving table 6 is moved at a predetermined speed.
A spiral groove 13 having a width equal to the cutting width of the cutting tool 5 as shown in FIG. This spiral groove 1
3 has a uniform depth as shown in FIG. 3 in a sectional view along the concave groove 13.

Next, the processing of the radially extending concave groove, which is a feature of the present invention, will be described. The main shaft 4 is rotated at a predetermined speed, and the workpiece 9 is rotated. In this state, the first and second moving tables 6 and 11 are moved so that the tip of the cutting tool 5 is brought into contact with the processing start point of the workpiece 9 and then the first moving table 6 is moved to a predetermined position. While moving at a speed, the drive signal generator 10 is controlled so as to obtain an output pulse having a cycle shorter than the rotation cycle of the spindle 4 (for example, 1/3 cycle). 1 / (for example, 1/3) of the rotation period of
When cutting while vibrating in the X direction with the cycle of
A spiral groove 13 having a width equal to the cutting width of the cutting tool 5 as shown in FIG. 4 is formed on the processing surface of the workpiece 9.

As shown in FIG. 5, a cross-sectional view of the spiral groove 13 along the groove 13 changes its depth in a sine curve in accordance with the vibration cycle of the cutting tool 5. Become. Therefore, the first moving table 6 is moved so that the spiral groove 13 formed in the first rotation of the workpiece 9 partially overlaps the spiral groove 13 formed in the subsequent second rotation. If the moving speed is adjusted, as shown in FIG. 6, three sine-curve concave grooves 14 extending in a fan shape from the rotation center of the workpiece 9 can be formed at equal intervals.

Thereafter, if necessary, the groove 14
When the front end portion (the portion shown as 15 in FIG. 6) of the intervening convex portion is turned and removed so as to be a flat surface, the flat surface can be formed into a shape in which a concave groove portion 14 having a sinusoidal bottom surface is formed. .

In the above-described configuration, the cutting tool 5 is synchronized with the rotation of the workpiece 9 and is divided by an integer fraction (for example, 1) of the rotation cycle.
An example of vibrating at a period of (/ 3) is shown. However, if it is set to a non-integral fraction (for example, 1 / approximately 2.9), the concave groove portion 14 that changes in a curve as shown in FIG. Can be formed. Further, if this vibration period is changed from the middle, the concave groove portion 14 whose curvature changes from the middle as shown in FIG. 8 or 9 can be formed.

In the above embodiment, the output waveform of the drive signal generator 10 has a sine curve shape. However, the output waveform of the drive signal generator 10 may be a square wave, a trapezoidal wave, a triangular wave, or the like. , Change the mold, etc.
By setting the clearance angle of the groove so as not to interfere with the shape of the groove, a more complicated groove shape can be cut.

Further, in the embodiment, the example in which the concave groove portion 14 is formed on the rotation plane of the workpiece is shown, but it is formed on the outer peripheral surface of the cylindrical body which is driven to rotate, and the inner and outer peripheral surfaces of the cylindrical body. You can also. That is, when the workpiece is a cylindrical body that is driven to rotate about its central axis, the cutting tool is pressed against the side surface of the cylindrical body, and while the cutting tool is vibrated in the pressing direction in this state, the cutting tool is rotated in the central axis direction. , A linear or spiral groove can be formed on the side surface of the cylindrical body.

For example, when the cutting tool is intermittently pressed for a short period at a period of 1/4 of the rotation period of the workpiece, four concave grooves parallel to each other are formed on the side surface of the workpiece 1 as shown in FIG. 14, and when the cutting tool is intermittently pressed for a short period at a cycle of 1 / 3.9, four spiral shapes parallel to each other are formed on the side surface of the workpiece 1 as shown in FIG. When a plurality of grooves 14 linearly or helically extending in the axial direction as shown in the grooves 14 are simultaneously formed, this can be achieved by vibrating the cutting tool.

[0018]

As described above, according to the present invention, the groove can be easily machined by the simple improvement of adding the function of vibrating the cutting tool in the pressing direction to the conventional turning machine. Yes, it is possible to cut the outer shape of the workpiece with the same equipment, and it is possible to cut the outer shape and groove with a so-called one chuck, and to achieve the concentric accuracy between the workpiece and the groove. Is also stable. Also, by changing the vibration cycle of the cutting tool, various shapes of concave grooves can be easily formed.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing an embodiment of a turning apparatus used in a method for turning a concave groove according to the present invention.

FIG. 2 is a plan view showing a machined surface of a workpiece to explain a concave groove forming process by the turning method of the present invention.

FIG. 3 is a side sectional view along a concave groove of a processing surface of a workpiece in the process of forming the concave groove portion.

FIG. 4 is a plan view showing a machined surface of a workpiece in a process of forming a groove by the groove turning method of the present invention;

FIG. 5 is a side sectional view along a groove of a processing surface of a workpiece in the process of forming the groove.

FIG. 6 is a plan view showing an example of a concave groove formed on a processing surface of a workpiece by the turning method of the present invention.

FIG. 7 is a plan view showing another example of the concave groove formed on the processing surface of the workpiece by the turning method of the present invention.

FIG. 8 is a plan view showing still another example of the groove formed on the processing surface of the workpiece by the turning method of the present invention.

FIG. 9 is a plan view showing still another example of the concave groove formed on the processing surface of the workpiece by the turning method of the present invention.

FIG. 10 is a side view and a cross-sectional view showing an example of a groove formed on the outer peripheral surface of a cylindrical workpiece by the turning method of the present invention;

FIG. 11 is a side view and a cross-sectional view showing an example of a groove formed on the outer peripheral surface of a cylindrical workpiece by the turning method of the present invention.

FIG. 12 is a plan view showing a processing surface of a workpiece for explaining a method of forming a groove by a conventional etching method.

[Explanation of symbols]

 Reference Signs List 1 spindle 2 byte 3 first moving table 4 control device 5 chuck 6 workpiece 7 drive signal generator 8 second moving table 9 vibrating device 10 concave groove 11 concave groove portion

Claims (9)

[Claims] 1. A cutting tool is pressed against a processing surface of a workpiece to be driven to rotate, and the cutting tool is vibrated in the pressing direction while transferring the cutting tool in a direction perpendicular to the pressing direction. A method of turning a groove to form one or more grooves continuously on a processing surface. 2. The vibration period of the cutting tool in the pressing direction is as follows:
2. The method according to claim 1, wherein the cycle is an integral multiple of a cycle synchronized with a rotation cycle of the workpiece. 3. The vibration cycle of the cutting tool in the pressing direction is as follows:
2. The method according to claim 1, wherein the period is a non-integer multiple of the rotation period of the workpiece. 4. The vibration period of the cutting tool in the pressing direction is
2. The method according to claim 1, wherein the cutting tool is changed during a transfer period. 5. The method according to claim 1, wherein the transfer of the cutting tool is performed along a line passing through a rotation center of a processing plane on which the workpiece is rotated, and a concave groove extending radially from the rotation center is formed in the processing surface. The method for turning a concave groove according to claim 1. 6. The workpiece is a cylindrical body that is driven to rotate about its central axis, and a cutting tool is pressed against a side surface of the cylindrical body and is transferred in the central axis direction. 2. The method according to claim 1, wherein a spiral groove is formed on a side surface of the cylindrical body. 7. A rotary driving means for holding a workpiece and rotating the processing surface thereof, a transfer means for pressing a tool against the processing surface, and transferring the tool in a direction perpendicular to the pressing direction. An apparatus for turning a concave groove, comprising vibrating means for vibrating the cutting tool in the pressing direction at a cycle shorter than a rotation cycle of the workpiece. 8. The vibration cycle of the cutting tool in the pressing direction is as follows:
8. The groove turning apparatus according to claim 7, wherein the cycle is an integral multiple of a cycle synchronized with a rotation cycle of the workpiece. 9. The vibration cycle of the cutting tool in the pressing direction is as follows:
8. The groove turning device according to claim 7, wherein the period is a non-integer multiple of the rotation period of the workpiece.