JPH11309628A - V-shaped groove forming method and manufacture of tool to be used for that method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a V-shaped groove having a free pattern, an even groove width and a sharp groove edge by feeding a top of a right circular cone into a work by the predetermined quantity while rotating the right circular cone around the center axis thereof, and relatively moving the right circular cone in parallel with the surface of the work. SOLUTION: A tool 1 is positioned on a surface of a work 2 while vertically standing the center axis A of the tool 1 against the surface of the work 2. A top of a right circular cone of the positioned tool 1 is fed into the work 2 while rotating the tool 1 around the center axis A thereof, and the tool 1 is moved in parallel with a surface of the work 2. In order to form a V-shaped groove having a target shape 5, the final target depth is divided into plural parts, and feeding of the tool to each target depth and the movement thereof on the surface of the work are repeated so as to gradually increase the depth. Consequently, a free pattern including a bent straight line and a covered line, besides a straight line, can be formed on the surface of the work 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a V-groove by machining using a diamond tool and a method for manufacturing a tool used therefor.

[0002]

2. Description of the Related Art There are various uses for a groove having a V-shaped cross section, which is generally called a V-groove. In recent years, demand for a fine and high-precision V-groove having a groove width or depth of a micro order has been increasing. . For example, a black frame pattern for confirming the position of a subject in the viewfinder field of view of a compact camera is formed by processing a frame pattern-shaped V groove in a mold used for injection molding of a resin prism incorporated in the viewfinder. By forming a peak with a V-groove transferred on the light transmitting surface of the prism, the refraction of the light passing through the peak is used to prevent the refracted light from reaching the finder, thereby blackening the frame pattern. I have. A V-groove shape represented by such an application requires not only uniformity of the groove width but also sharpness of a groove edge where two side surfaces intersect.

When the above-mentioned V-groove is formed by machining, the shape of a diamond tool generally used as a cutting tool is constituted by a plane such as a rake face and a flank face. FIG. 5 shows V using such a diamond tool.
FIGS. 5A and 5B show a method of processing a groove, in which FIG. 5A is a cross-sectional view in a groove side direction and FIG. 5B is a cross-sectional view in a groove cross-sectional direction. As shown in FIG. 5, the tool 20 is moved in one direction relative to the workpiece surface in a state where the tool 20 is fed into the inside from the processing surface, and the apex angle formed by the two flat surfaces at the tip of the tool 20 is transferred. The V-groove is machined by cutting the workpiece while cutting.

[0004]

However, in the cutting tool used in the above-mentioned conventional method, since the direction of the cutting blade is determined, the cutting direction can be freely set on the processing surface while keeping the groove width and the groove edge constant. It is impossible to process straight lines or curves. Further, when a cutting tool is manufactured in accordance with the specifications such as the angle of the V-groove, since the shape is a combination of planes, the processing process becomes complicated. In addition, there is a possibility that a processing error such as an angle shift caused by a mounting error of the cutting tool may occur.

Therefore, there is a need for a V-groove processing method capable of freely processing a straight line or a curve on a processing surface while maintaining a constant groove width and a sharp groove edge. It is an object of the present invention to provide a method of forming a V-groove with a high degree of freedom and a method of manufacturing a tool for forming a V-groove using a conventional tool.

[0006]

In order to achieve the above object, a method of forming a V-groove according to the present invention is directed to a method of forming a tool made of a diamond sintered body in which a cylindrical end is formed into a right cone, wherein the vertex of the right cone is the surface of the workpiece. To the shortest distance, and while rotating around the central axis, feeding the top of the right cone into the workpiece by a predetermined amount, and moving the top of the right cone in a direction parallel to the workpiece surface. It is a feature.

According to the above method, a tool made of a sintered diamond body is symmetrical with respect to its center axis and performs groove processing while rotating, so that there is no processing directionality.
In addition, due to the high wear resistance of sintered diamond, V-grooves having a uniform groove width and sharp groove edges are formed on the surface of the workpiece with a free pattern including straight lines as well as refracted straight lines and curves. can do.

In the case of forming a V-groove, the final target depth of the V-groove is divided into a plurality of parts, and the tool is repeatedly fed at each of the divided target depths and the relative movement in the surface direction of the workpiece is repeated to gradually increase the depth. Finishing can be performed by reducing the resistance to the tool and by making the feed amount minute immediately before reaching the final target depth.

Further, the method of manufacturing a V-groove forming tool according to the present invention is characterized in that a right circular conical surface is formed by electrical discharge machining of a tip of a sintered diamond cylinder.

In the electric discharge machining, a flat plate-shaped electric discharge machining electrode is arranged so as to be parallel to a target straight line of a straight cone with respect to a central axis of the diamond sintered body cylinder. While rotating around the central axis,
Electric discharge machining is performed by bringing the tip portion close to the electric discharge machining electrode.

Alternatively, a diamond sintered body cylinder is arranged in a direction orthogonal to an electric discharge machining electrode formed of a wire, and a tip end portion thereof is approached with a predetermined interval therebetween so that the diamond sintered body cylinder is centered on its central axis. While rotating, electric discharge machining is performed by relatively moving in the direction parallel to the target straight cone generating line on the side facing the electric discharge machining electrode.

According to the above-mentioned method for producing a tool, by performing electrical discharge machining utilizing the high conductivity of a diamond sintered body, a straight cone shape can be easily and accurately formed despite being a hard material. Obtainable. Further, since the electrical discharge machining is performed while rotating the diamond sintered body column about its central axis, the machining can be performed from one direction, and the rotating operation can be applied to V-groove formation as it is.

[0013]

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

(Embodiment 1) FIG. 1 shows a method of forming a V-groove according to Embodiment 1 of the present invention. FIG.
In the figure, 1 is a tool made of a diamond sintered body in which the tip of a cylinder is formed in a right circular cone, and 2 is a workpiece. FIG.
(A) shows the intermediate shape 4 in the middle of forming the groove of the target shape 5;
FIG. 1B is a cross-sectional view in a side-surface direction showing a state in which the process has been performed, and FIG.

In the V-groove forming method, first, the tool 1 is positioned upright so that its center axis A is perpendicular to the surface of the workpiece 2. This positioning is confirmed by obtaining an energized state between the tool 1 and the workpiece 2 when the workpiece 2 has conductivity. Even if the workpiece 2 is an insulator,
The same is confirmed by imparting conductivity by depositing a metal thin film on the processed surface. Position the tool 1
While rotating about the central axis A, the top of the right cone is fed into the workpiece 2 by a predetermined amount, and the workpiece 2
Move parallel to the surface.

In order to form the V-groove of the target shape 5, the final target depth is divided into a plurality of parts, and the tool feeding and the movement of the workpiece 2 toward the surface at each of the divided target depths are repeated to increase the depth sequentially. Go. Numeral 3 represents the trajectory of the tip of the tool 1 when the final target depth is divided into four.

According to the V-groove forming method of the first embodiment configured as described above, the tool 1 made of a diamond sintered body is symmetrical with respect to its central axis A, and is rotated while rotating the groove. Since the processing is performed, there is no directionality of the processing, so that a free pattern including not only straight lines but also refracted straight lines and curves can be formed on the surface of the workpiece. FIG. 2 shows an example of a V-groove pattern 6 having a curve or a bending point, and processing like a single stroke is possible.
Then, a V-groove having a constant groove width and a sharp groove edge can be formed by the high wear resistance of the sintered diamond.

Further, by dividing the final target depth into a plurality of parts and performing processing in a plurality of steps, the resistance to the tool can be reduced. Further, in the processing of the step close to the target shape 5, the feeding amount is made smaller than the feeding amount in the first step, thereby performing the finishing processing and obtaining a smooth V-groove side surface.

Furthermore, since the tool 1 is made of a high-hardness diamond sintered body, the tool 1 has excellent wear resistance and can minimize dripping of the tip of a right circular cone due to tool wear during machining.

(Embodiment 2) In order to form a high-precision V-groove, it is necessary to manufacture a tool having a high-precision straight conical shape at the tip. FIG. 3 shows a method for manufacturing a V-groove forming tool according to Embodiment 2 of the present invention, in which the tip of a diamond sintered body cylinder is subjected to electric discharge machining to form a straight conical surface.

As a method of the electric discharge machining, a center axis A of a diamond sintered body cylinder (represented by reference numeral 1 similarly to a tool) is used.
On the other hand, a plate-shaped electric discharge machining electrode (hereinafter, referred to as a plate-shaped electrode) 7 is arranged so as to be parallel to a target straight cone generating line. The plate electrode 7 is connected to a DC power source 8 via a resistor 9.
Negative electrode connected to a negative electrode to form a diamond sintered compact cylinder 1
Is connected to the + pole of the DC power supply 8 to form an anode. The capacitor 10 is connected in parallel with the DC power supply 8 to form a charging type electric discharge machining circuit.

Next, a predetermined voltage is applied between the diamond sintered body cylinder 1 and the plate electrode 7, and the tip of the diamond sintered cylinder 1 is made to approach the plate electrode 7 while rotating. Thereby, the machining by the electric discharge 11 is started,
When the diamond sintered body cylinder 1 is fed until the bottom surface is exhausted, a straight cone having a very sharp tip and a uniform conical surface is formed.

In this electric discharge machining, by setting the voltage to 70 V and the capacitor capacity to 10 pF, the R at the tip becomes 1 μm.
The following right cone is obtained: Further, according to this method, a vertex of a right circular cone is formed on the rotation axis (center axis A) of the diamond sintered body cylinder 1, and the vertex has no rotational fluctuation.
The rotating shaft at the time of producing the tool can be used as it is for groove processing, and a sharp groove edge can be obtained.

(Embodiment 3) FIG. 4 shows a method of manufacturing a V-groove forming tool according to Embodiment 3 of the present invention, wherein a straight conical portion of the tool 1 is formed by another method of electric discharge machining. Is what you do. Here, a wire electrode 12 is used as a cathode, and the other electrical connections are the same as in the second embodiment.

The diamond sintered body cylinder 1 is arranged in a direction perpendicular to the wire electrode 12 and the tip is made to approach with a predetermined interval. A predetermined voltage is applied between the diamond sintered body cylinder 1 and the wire electrode 12, and the diamond sintered body cylinder 1 is rotated around the central axis A to be a target on the side facing the wire electrode 12. Electric discharge machining is performed by moving relative to the right cone parallel to the generatrix. During the discharge, the wire electrode 12 is continuously fed in a direction perpendicular to the plane of FIG. 4 so that a new wire is always supplied to the discharge unit. By doing so, the effect of machining errors due to electrode wear caused by electric discharge machining can be reduced to a negligible extent.

Also in the method of manufacturing the V-groove forming tool according to the third embodiment, the tool 1 can be formed into a high-precision straight conical shape without rotational fluctuation.

[0027]

As described above, according to the V-groove forming method of the present invention, the groove is formed while rotating a tool made of a diamond sintered body having high wear resistance and symmetric with respect to the center axis thereof. Since the processing is performed, there is no processing directionality. Therefore, on the surface of the workpiece, a free pattern including not only straight lines but also refracted straight lines and curves, V grooves having a uniform groove width and sharp groove edges are provided. Grooves can be formed.

Further, according to the method of manufacturing a V-groove forming tool of the present invention, since a diamond sintered body is subjected to electric discharge machining to form a right conical shape, high precision is achieved despite the fact that it is a material having high hardness. It is possible to easily obtain a right conical shape without rotational shake. Furthermore, since the electric discharge machining is performed while rotating the diamond sintered body cylinder about its central axis, machining from one direction is sufficient, and the rotating shaft at the time of tool production can be used as it is for groove machining, A sharp groove edge can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a V-groove forming method according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a processing example by a V-groove forming method according to the first embodiment of the present invention;

FIG. 3 is a diagram showing a method for manufacturing a V-groove forming tool according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a method for manufacturing a V-groove forming tool according to a third embodiment of the present invention.

FIG. 5 is a sectional view showing a conventional V-groove forming method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tool (diamond sintered cylinder) 2 Workpiece 3 Locus of tool tip 4 Intermediate shape 5 Target shape 6 V groove pattern 7 Plate electrode 8 DC power supply 9 Resistance 10 Capacitor 11 Discharge 12 Wire electrode

Claims (5)

[Claims] 1. A tool made of a diamond sintered body in which the tip of a cylinder is formed in a right circular cone is set so that the vertex of the right circular cone is the shortest distance to the surface of the workpiece, and is rotated about a central axis. A V-groove forming method, wherein a top portion of the right cone is fed into a workpiece by a predetermined amount and is relatively moved in a direction parallel to a surface of the workpiece. 2. The method according to claim 1, wherein the final target depth of the V-groove is divided into a plurality of parts, and the tool feeding and the relative movement in the surface direction of the workpiece at each of the divided target depths are repeated to increase the depth sequentially. V-groove forming method. 3. A method for producing a V-groove forming tool, comprising forming a right circular conical surface by electric discharge machining of a tip of a diamond sintered body cylinder. In the electric discharge machining, a flat plate-shaped electric discharge machining electrode is arranged so as to be parallel to a target straight cone generating line with respect to a central axis of the diamond sintered body cylinder. The method for producing a V-groove forming tool according to claim 3, wherein the electric discharge machining is carried out by rotating a center axis thereof as a center while bringing a front end portion close to the electric discharge machining electrode. 5. An electric discharge machining method, wherein a diamond sintered body cylinder is arranged in a direction orthogonal to an electric discharge machining electrode formed of a wire, and a tip portion thereof is approached with a predetermined interval therebetween.
The electric discharge machining is performed by rotating the diamond sintered body cylinder about its central axis while relatively moving in a direction parallel to a target straight cone generating line on the side facing the electric discharge machining electrode. Item 4. The method for producing a V-groove forming tool according to Item 3.