JP2001162429A - Grooving method and grooving tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grooving method that can machine a groove even in a form other than a straight or perpendicular form. SOLUTION: The grooving method is for grooving a die used for molding an optical part. A machining tool 10 with a pyramid edge 10c at the point and further with an angle α or half the open angle 2α of a groove to be machined between each pyramid ridge and a center axis 22 is thrust into the die while rotated to machine a groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a groove used for forming a mold for integrally forming a fine convex pattern such as a distance measuring mark on a transparent resin optical component used for a camera or the like. Method and grooving tool.

[0002]

2. Description of the Related Art Conventionally, when a fine convex pattern such as a distance measuring mark is formed on an optical component of a camera, a groove pattern having the same shape as the convex pattern to be formed is formed in a mold. In general, the above-mentioned convex pattern is integrally formed on an optical component using a mold.

FIG. 1 is a view showing an example of a mold having a groove pattern as described above, wherein (a) is a plan view of the mold,
(B) is an AA sectional view of (a), and (c) is a side view of a mold.

In FIG. 1, a mold 2 has a fine groove 4 for forming a distance measuring mark on an optical component. In this example, the opening angle of the groove 4 is 2α as shown in FIG.

FIG. 2 is a view showing the shape of a conventional machining tool for machining (cutting) grooves as shown in FIG. 1 into a mold, and FIG. 2 (a) is a side view of the machining tool. (b) is a front view of the working tool. The tip of the processing tool 100 is formed in the shape of a quadrangular pyramid, and its slope (the plane B and the plane C in FIG.
As shown in FIG. 2 (a), the opening angle between
2α, which is the same as the opening angle of the groove 4. Further, a diamond tip 102 is embedded at the tip of the processing tool 100.

[0006] Using such a working tool 100, a mold 2
When the groove 4 is to be scored, the machining tool 100 is mounted on a precision machine tool such as a jig borer, for example.
The plane A shown in (b) is set to be perpendicular to the center line of the groove 4 to be processed. Then, the processing tool 100 is brought close to the mold 2, the state at that time is observed with a microscope, and the tool is positioned at a predetermined position. While moving the mold 2 within the range of the length of the groove 4, the tool is gradually approached to cut the mold 2 to a predetermined depth from a point where a streak is formed on the mold 2 for the first time to perform a score line processing. At this time, the machining is performed without rotating the machining tool 100 while keeping the surface A perpendicular to the center line of the groove 4.

[0007]

However, in the above-mentioned prior art, since the surface A of the processing tool 100 must always be kept perpendicular to the center line of the groove to be processed, the shape of the processing surface is flat. In addition, processing is limited to the case where the shape of the groove is orthogonal to the shape of the groove. If the shape of the engraved line is not orthogonal or curved as shown in FIG. Was impossible.

Accordingly, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a groove machining method and a groove machining tool capable of machining a groove having a shape other than a straight line or an orthogonal straight line. That is.

[0009]

Means for Solving the Problems To solve the above-mentioned problems,
In order to achieve the object, a groove processing method according to the present invention includes:
A grooving method for performing grooving on a mold for molding an optical component, wherein the processing tool has a pyramid-shaped blade at a tip, wherein the pyramid-shaped ridge line is at a center axis of the processing tool. On the other hand, it is characterized in that a machining tool formed so as to form an angle of 1/2 of an opening angle of a groove to be machined is cut into the mold while rotating, thereby machining the groove.

Further, in the groove machining method according to the present invention, the pyramid shape is a triangular pyramid shape.

Further, in the groove machining method according to the present invention, the pyramid shape is a quadrangular pyramid shape.

In the groove machining method according to the present invention, the optical component is an optical component used for a camera, and a portion formed by the groove is a distance measuring mark.

[0013] A grooving tool according to the present invention is a grooving tool for performing grooving on a mold for molding an optical component, the grooving tool being provided at a tip of the processing tool body. And a pyramid-shaped blade provided, wherein the pyramid-shaped ridge is formed so as to form an angle of a half of an opening angle of a groove to be machined with respect to a center axis of the machining tool main body. It is characterized by:

Further, in the grooving tool according to the present invention, the pyramid shape is a triangular pyramid shape.

In the grooving tool according to the present invention, the pyramid shape is a quadrangular pyramid shape.

Further, in the groove machining tool according to the present invention, the optical component is an optical component used for a camera, and a portion formed by the groove is a distance measuring mark.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The workpiece to be machined in this embodiment is the same as the mold of FIG. 1 already described in the section of the prior art.

In FIG. 1, a mold 2 is for integrally forming a distance measuring mark (convex pattern) on a transparent resin optical component used for a camera. The mold 2 is made of mold steel as a material, and is formed by applying electroless chemical nickel (KN) plating to the surface thereof, and the cut line processing surface (the surface forming the groove 4) is mirror-finished.

FIGS. 4A and 4B are views showing an example of a working tool used for cutting lines (grooves) in this embodiment, wherein FIG. 4A is a side view of the working tool, FIG. () Is a side view of (b) as viewed from a direction at an angle of 45 °.

In FIG. 4, the machining tool 10 is formed by forming a cylindrical portion 10b at the tip of a regular square column-shaped main body portion 10a and forming a square pyramid-shaped cutting edge portion 10c at the tip of the cylindrical portion 10b. I have. A diamond tip 12 is embedded in the tip of the cutting edge 10c. Column part 10b
Has a diameter of 9 mm, for example. Further, the quadrangular pyramid portion of the cutting edge portion 10c is composed of an A surface, a B surface, a C surface, and a D surface, and as shown in FIG. 4C, the ridge lines 14, A between the A surface and the B surface. The angle formed by the ridge line 16 between the surfaces C and C, the ridge line 18 between the C surface and the D surface, the ridge line 20 between the D surface and the B surface, and the central axis 22 of the machining tool 10, respectively, It is set to α which is half of the angle 2α. As a result, the angle between the opposing ridge lines 14 and 18 and the angle between the ridge lines 16 and 20 are each 2α. When the processing tool 10 is rotated to process the groove 4, the opening angle of the groove 4 is processed to 2α. It will be.

The processing angle θ of the A, B, C, and D planes for setting the angle between each ridge line and the central axis 22 to α is obtained by the following equation.

Tan θ = tan α / √2 When the machining tool 10 is manufactured, each of the A-plane, B-plane, C-plane, D-plane
Process the surface.

FIGS. 5A and 5B are views showing another example of a working tool used for cutting lines (grooves) in this embodiment, wherein FIG. 5A is a side view of the working tool, and FIG. is there.

Referring to FIG. 5, a machining tool 30 is formed by forming a cylindrical portion 30b at the tip of a main body 30a having a square prism shape, and forming a triangular pyramid-shaped cutting edge portion 30c at the tip of the cylindrical portion 30b. I have. A diamond tip 32 is embedded in the tip of the cutting edge 30c. Column part 30b
Has a diameter of 9 mm, for example. In addition, the triangular pyramid portion of the cutting edge portion 30c is composed of an A surface, a B surface, and a C surface,
As shown in FIG. 5B, a ridgeline 34 between the A surface and the B surface,
Ridge 36 between A and C planes, Ridge 38 between C and B planes
And the center axis 42 of the machining tool 30 are set to α, which is half the opening angle 2α of the groove 4. Thereby, if the groove 4 is machined by rotating the machining tool 30,
The opening angle of the groove 4 is processed to 2α.

The machining angle θ of the A-plane, B-plane, and C-plane for setting the angle between each ridge line and the center axis 42 to α is obtained by the following equation.

Tan θ = tan α / 2 When the machining tool 30 is manufactured, each of the A-plane, B-plane, and C-plane of the triangular pyramid is machined so as to have the angle θ obtained from this equation.

In the example shown in FIG. 4, since the angle θ is larger than that of the triangular pyramid tool shown in FIG. 5, the tool strength can be increased.

In the example shown in FIG. 5, the angle .theta. Is smaller than that of the square pyramid tool shown in FIG. Since the intersection always crosses at one point, it is easy to manufacture a tool.

Next, FIG. 7 shows a tool base material in which a cylindrical portion 30b is formed on a regular square column-shaped main body portion 30a as shown in FIG. 5 for explaining a method of manufacturing the working tool shown in FIG. It is attached to a jig 60 having a square pillar cavity inside. The outside of the jig 60 is formed in a regular triangular prism shape. The tool base material is fixed to the jig 60, and a surface inclined by θ with respect to the A surface is machined into a tool surface. Next, when a plane inclined by θ with respect to the planes B and C is machined into a tool plane, a triangular pyramid-shaped tool is obtained. At that time, the allowance of each surface of the triangular pyramid can be set arbitrarily, so that tool production can be facilitated.

FIG. 6 is a view showing a holder for mounting the working tool shown in FIGS. 4 and 5.

In FIG. 6, the A surface, which is the bottom surface of the holder 50, is attached to the end of the main shaft of a machine tool that performs a line cutting process. It is necessary to maintain high-precision rotation accuracy of the main shaft of the machine tool. For example, a high-precision main shaft such as an air bearing is used.

Next, a procedure for performing the score line processing using the above-described processing tool will be described. First, FIG. 4 or FIG.
6. The working tool 10 or 30 shown in FIG.
After screwing to 0, the holder 50 is placed on a measuring microscope having a precision rotary table with the A side as the bottom surface.
At this time, the cylindrical portion 10b or 30b of the processing tool and the center of the rotary table are made to coincide with high accuracy (1 μmm or less).

Next, the apex of the processing tool is measured with a measuring microscope, and the rotary table is rotated by 180 °. Then, the tool vertex is 2% of the misalignment with the center of the cylindrical portion 10b or 30b.
Since the tool moves twice, it is possible to know in which direction and how much the center of the cylinder should be moved in order to match the center of the cylinder with the vertex of the tool.

Based on the result, the cylindrical portion 10 of the machining tool
b or 30b is reground by another machine tool (for example, a jig grinder or a cylindrical grinder). Then, the above operation is repeated again on the measuring microscope. If the centers match, the operation is repeated, and if not, the above operation is repeated again.

Next, the processing tool integrated with the holder 50 is attached to a machine tool for performing the score line processing. This machine tool is an NC machine tool capable of controlling three or more axes of X, Y and Z, and it is necessary that the movement accuracy of each axis is very precise and has high reproducibility. When attaching the machining tool 10 or 30 to the main shaft of the machine tool, the machining tool 10 or 30 is attached so that the run-out of the cylindrical portions 10b and 30b is extremely small. After the attachment to the main shaft is completed, the high-speed rotation is unbalanced by using the screw holes 52 of the holder 50. When the balance is finished, the preparation of the tool is completed, the mold 2 is set on the table of the machine tool, the relative position of the machining tool 10 or 30 and the mold 2 is set, and then the machining tool is rotated to obtain a predetermined cut. Processing is performed by giving a shift motion.

According to the processing method as described above, the main spindle of the machine tool moves in three axial directions, so that a distance measuring mark or the like is required on a curved surface, for example, a spherical surface as shown in FIG. It can also be applied to the case where the shape such as is a curve. When the mark is directly applied to the spherical surface, the mark is added to the lens surface of the molded product, so that the number of transparent parts indicating the mark can be reduced by one, and the cost of the product can be reduced.

Next, a specific example of processing a mold using the processing method of the above embodiment will be described.

A description will be given by taking the processing of the mold of FIG. 1 as an example.

A steel material slightly larger than the dimensions shown in FIG. 1 is cut out, milled into a hexahedron, and ground with a surface grinder with high precision. The dimensions of the hexahedron at this time are made 0.1 mm smaller than the finished dimensions.

Electroless nickel (KN) plating is formed on this material to a thickness of about 150 μm. The surface other than the scored surface is finished to the final dimensions with a surface grinder. The engraved surface is mirror-finished by fly cutting with a diamond tool. Thereafter, lapping is performed to obtain a final finished surface (surface roughness Hmeam: 0.01 μm or less). Using a square pyramid tool shown in FIG. One cut is 1 μm, and the speed is approximately 1 μm / rev. The cutting fluid is turned into oil mist and sprayed on the machined surface. As a result of such processing, a scored line processing result of 22.5 μm width was obtained with respect to a target scored line width (groove width) of 25 μm. Also, the shape of the machined groove was able to obtain a good scored line shape with no plastically deformed portions and few burrs.

As described above, according to the above embodiment, the following effects can be obtained. (1) The shape of the score line can be processed accurately and the finished surface is beautiful. (2) A curved surface (R surface, etc.) whose surface to be engraved has a shape other than a flat surface
But processing is possible. (3) It is possible to machine even a skewed shape or a curved shape in which the shape of the score line is not orthogonal.

[0043]

As described above, according to the present invention,
It is possible to machine grooves having a shape other than a straight line or an orthogonal straight line.

[Brief description of the drawings]

FIG. 1 is a view showing the shape of a die to be scored.

FIG. 2 is a diagram showing a conventional scored line processing tool.

FIG. 3 is a view showing a mold having a curved surface on which a line to be cut is formed;

FIG. 4 is a diagram showing an example of a shape of a working tool used in an embodiment of the present invention.

FIG. 5 is a diagram showing another example of the shape of a working tool used in an embodiment of the present invention.

FIG. 6 is a view showing the shape of a tool holder.

FIG. 7 is a view showing a shape of a jig for manufacturing a working tool.

[Explanation of symbols]

 2 mold 4 groove 10 processing tool 12 diamond tip 14,16,18,20 ridge 22 center axis 30 processing tool 32 diamond tip 34,36,38 ridge 42 center axis 50 holder 52 screw hole 60 jig

Claims (8)

[Claims] 1. A grooving method for grooving a mold for forming an optical component, comprising: a processing tool having a pyramid-shaped blade at a tip, wherein the pyramid-shaped ridge is formed by the processing. Cutting a groove into the mold while rotating a processing tool formed so as to form an angle of 1/2 of an opening angle of a groove to be processed with respect to a center axis of the tool, thereby processing the groove. Groove processing method. 2. The method according to claim 1, wherein the pyramid shape is a triangular pyramid shape. 3. The groove processing method according to claim 1, wherein the pyramid shape is a quadrangular pyramid shape. 4. The groove processing method according to claim 1, wherein the optical component is an optical component used for a camera, and a portion formed by the groove is a distance measurement mark. 5. A grooving tool for performing grooving on a mold for forming an optical component, comprising: a processing tool main body; and a pyramid-shaped blade provided at a tip of the processing tool main body. A grooving tool, wherein the pyramid-shaped ridge line is formed at an angle of a half of an opening angle of a groove to be processed with respect to a center axis of the processing tool body. 6. The grooving tool according to claim 5, wherein the pyramid shape is a triangular pyramid shape. 7. The grooving tool according to claim 5, wherein the pyramid shape is a quadrangular pyramid shape. 8. The groove machining tool according to claim 5, wherein the optical component is an optical component used for a camera, and a portion formed by the groove is a distance measurement mark.