JP2013202750A - Method for machining angular part/corner part, method for manufacturing die using the method for machining, die manufactured by the method for manufacturing and molded product molded using the die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the following problems: a highly accurate angular part or corner part cannot be produced by cutting for a die of a reflex reflector; the die is therefore manufactured by electroforming using an arrow-shaped pin; and thus labor and time are required; a manufacturing error tends to occur; and further high cost is required.SOLUTION: An angular part or a corner part can be highly accurately produced in even cutting by applying elliptic vibrations. Accordingly, when a cutting tool 21 with a cutting edge part including angular cutting edge ridge line parts 27 and 29 is used and cutting is performed in accordance with a tool path P, angular parts 11, 13 and 15 and three surfaces 5, 7 and 9 for forming a corner part where respective ends are gathered can be simultaneously finished in sweeping shapes of the cutting edge ridge line parts 27 and 29, and a recess 3 of a reflex reflector can be manufactured with the so-called one stroke.

Description

  The present invention relates to a method for processing corners / corner corners, and more particularly to a method for processing corners / corner corners included in a closed three-dimensional recess like a mold.

Even in the processing of molds and even general products, it is often necessary to create corners that correspond to corners or corners in closed three-dimensional recesses as shown in FIG.
In such a case, conventionally, as shown in FIG. 2, the opposite shape is made by cutting, and the shape is transferred by, for example, electric discharge machining to produce a target rough shape, and further polished. For this reason, the accuracy is not high, and it takes time and effort, and not only the processing efficiency is low, but also the cost is high.

In addition, as an example of a product having a fine and complicated shape, there is a reflector called a reflex reflector. When the reflex reflector is attached to an automobile, etc., the light emitted from the other vehicle is reflected back in the direction of the other vehicle. The car can be informed.
Although this reflex reflector is a molded product produced by an inversion type, it cannot be accurately handled by a mold produced by the above-described electric discharge machining, and as shown in Patent Document 1, many arrow-shaped pins are bundled. In this way, a mold was used which was made into a matrix and subjected to electroforming plating treatment.
However, this method is also prone to manufacturing errors and takes more time than the above-described electric discharge machining.

JP 2005-125649 A

Even when creating corners and corners, if cutting can be done, labor is not required and machining efficiency increases.However, cutting with a rotary tool such as an end mill cannot produce corners that are less than the turning radius. The above-mentioned method has been used reluctantly to produce corners with high accuracy.
The present invention has been made paying attention to the above-mentioned conventional problems, and it is a novel and useful machining method that can solve the above-mentioned problems by creating high-precision corners and corners while being a cutting method. The purpose is to provide

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the invention of claim 1 is directed to a cutting tool motion component in a cutting direction in a method of processing corners / corner corners included in a recess closed by cutting. The machining method is characterized in that an elliptical vibration is applied so as to have a cutting motion relative to the work material.

  A second aspect of the present invention is the processing method for corners / corner corners according to the first aspect, wherein the cutting is continuously performed while changing the cutting direction.

  The invention of claim 3 is characterized in that in the corner / corner corner machining method according to claim 1 or 2, the cutting movement is performed while applying an elliptical movement in a direction in which the flank faces away from the cut surface. It is a processing method.

  According to a fourth aspect of the present invention, in the corner / corner corner processing method according to any one of the first to third aspects, in addition to the feeding motion, the surfaces forming the corners / corner corners by the feeding motion are also simultaneously formed. It is a processing method characterized by producing.

  According to a fifth aspect of the present invention, in the corner / corner corner processing method according to any one of the first to third aspects, a cutting tool having a cutting edge portion provided with a cutting edge ridge line portion is used. The processing method is characterized in that a surface that forms a corner is also created simultaneously by transferring the sweep shape of the contour.

  According to a sixth aspect of the present invention, in the corner / corner corner processing method according to the fifth aspect of the present invention, when forming a concave portion constituted by three corner portions and one corner portion orthogonal to each other, Using a cutting tool having a cutting edge with a cutting edge ridge line, and cutting while adjusting the cutting edge ridge line on one side to be present on the surface including the tool path, the sweep shape of the contour of the cutting edge ridge line In this processing, the three surfaces forming the corner and the corner are also simultaneously finished.

  The invention of claim 7 is the processing method for corners / corner corners according to claim 5 or 6, characterized in that a plurality of recesses are formed side by side on a flat surface or curved surface.

Invention of Claim 8 is a manufacturing method of a metal mold | die provided with the process of forming the corner | angular part contained in a recessed part or a corner | angular part, and a corner corner using the method as described in any one of Claim 1-7.
A ninth aspect of the invention is a mold manufactured by the manufacturing method of the eighth aspect.
The invention of claim 10 is a molded product molded using the mold of claim 9.

  According to the corner / corner corner machining method of the present invention, it is possible to create corners / corner corners with high accuracy by cutting, which does not require time and effort.

It is an example of the three-dimensional structure manufactured using the processing method of the corner | angular part and corner | angular corner part of this invention. It is explanatory drawing in the case of manufacturing the three-dimensional structure of FIG. 1 by the conventional method (electric discharge machining). It is explanatory drawing at the time of producing a corner | angular part and a corner corner using the processing method of a corner | angular part / corner corner part of this invention. It is explanatory drawing of the tool path of the cutting tool in the case of manufacturing the three-dimensional structure of FIG. 1 using the processing method of the corner | angular part and corner corner part of this invention. It is a perspective view which shows the state immediately after manufacture of one recessed part by the processing method of the corner | angular part and corner | angular corner part which concerns on embodiment of this invention. FIG. 6 is a five-side view of a cutting edge portion of the cutting tool used in FIG. 5. It is the upper side figure and sectional drawing of the recessed part manufactured in FIG. It is a side view which shows the contact attitude | position of the blade edge | tip part of the cutting tool in manufacture in FIG. 5, and the locus | trajectory of elliptical vibration. It is a perspective view which shows the movement locus | trajectory of the blade edge | tip part of the cutting tool in manufacture in FIG. It is a top view of the metal mold | die of the reflex reflector produced by arranging many recessed parts of FIG. 5 on a plane. FIG. 6 is a side view showing a stage in the middle of manufacturing a mold for a reflex reflector by arranging a large number of recesses in FIG. 5 on a curved surface.

A. General Corner / Corner Corner Machining Method As shown in FIG. 3 (1), when a cutting tool is used to give only a cutting motion toward a corner of a work material that is formed in advance roughly, cutting is performed. At the corner, the cutting speed becomes zero, and at least in the vicinity thereof, the cutting speed is extremely low.
At such a low cutting speed, the friction force generated between the chip and the tool rake face or between the finished surface and the tool flank face has a drooping characteristic (characteristic that the friction force decreases as the speed increases). Therefore, it is known that frictional vibration (including stick-slip) that is one of self-excited vibrations is likely to occur. If this vibration occurs, the corner cannot be created with high accuracy. However, in the present invention, cutting is performed while applying a minute high-frequency elliptical vibration (including circular vibration) indicated by a curve in the drawing so that the cutting tool A has a motion component in the cutting direction. Therefore, the actual cutting speed does not become zero or extremely small. Therefore, the problem of frictional vibration does not occur.

  Also, at such a low cutting speed, the new surface of the work material that has just separated and the tool surface tend to adhere due to the combination of the work material and the tool material, and the finished surface may peel off or the tool surface may peel off. Cause problems. However, in the present invention, since the cutting edge always has a vibration speed as described above, the adhesion phenomenon hardly occurs. In addition, by increasing the maximum vibration speed in the cutting direction from the cutting speed (apparent average speed), the tool is detached from the work material at each vibration cycle, so the new surface of the work material becomes dirty with air or cutting oil. It is considered that the chemical activity is reduced and adhesion is suppressed.

  In addition, by making the vibration trajectory not an straight line but an ellipse, in the plane including the cutting direction and the cutting thickness direction, at the moment of cutting, the tool has a speed in the chip discharge direction relative to the tool, The frictional force that prevents the chip from flowing out is not generated, and the chip outflow can be promoted. In addition, in the plane including the cutting direction and the ridge line direction of the cutting edge, at the moment of cutting, the speed of the so-called cutting direction is given, so that the chip can be generated and cut easily so that it is easy to cut while pulling with a knife. Emission can be promoted. In practical (ie, three-dimensional) corner processing, an elliptical vibration surface is used as the surface between the two to obtain an intermediate effect between the two. Compared with the case where no is added, chip generation / discharge is greatly facilitated.

  Note that the phase relationship between the vibration in the cutting direction and the vibration in the cutting thickness direction is not the direction in which the finished surface is crushed by the flank, but the flank (not necessarily a single plane, but two in practical cutting). The above-mentioned plane or curved surface (all these surfaces) can be mirror-finished by adjusting so that the elliptical motion of all these surfaces always away from the finished finished surface.

Further, as shown in FIG. 3 (2), it is possible to create a corner portion with a continuous tool path by changing the direction of the cutting motion.
Before and after the cutting direction suddenly changes at the corner, the rake angle and clearance angle of the tool with respect to the cutting direction change greatly. In front of the corner, the rake angle is large (on the positive side) (the blade is sharp), so that the cutting resistance is small, and chip generation and discharge are easy. On the other hand, after the corner, the rake angle is small (absolute value on the negative side is large, the blade is dull), so the cutting resistance is large and it becomes difficult to generate and discharge chips. Depending on the shape of the tool, it may be impossible to generate and discharge chips.
In addition, the back force (direction of the cutting thickness, the component in the cutting direction and the direction perpendicular to the cutting edge) increases especially after the corners, so it is desirable to modify the work material and tool, and the mechanical structure that supports them. This makes it impossible to realize the desired cutting, resulting in problems such as failure to create a desired shape and missing tools. In difficult-to-cut materials such as mold steel, it is practically impossible, and even when it is not possible, the finished surface properties after the corners deteriorate (there are problems such as swell and whip).
However, in the present invention, since elliptical vibration is given, even if the cutting direction changes, the relative vibration trajectory relative to the vibration direction hardly changes, and the vibration effect with respect to the cutting direction can be enjoyed as it is. By promoting this, the back force is reduced, machining errors and flash problems due to deformation are greatly reduced, and highly accurate corners can be created.
In addition, when the tool is detached from the work material with the tool posture immediately after the corner, there may be a problem that the so-called exit beam becomes large. The component force is reduced, and the problem of machining errors and flash due to deformation is greatly reduced.

When a part of the locus of elliptical vibration is transferred to the machining shape and remains, a slight roundness remains at the corner, but unlike when rotating an end mill tool or the like with a radius of (sub) millimeter order. The amplitude of the elliptical vibration can be as small as a micrometer order, and does not become a problem as a corner of a general product (including a mold).
In addition, since the frequency of elliptical vibration generally uses the high frequency in the ultrasonic region, a relatively large mechanical structure cannot respond, and as a result, hardly deforms, so that the machining accuracy is not adversely affected. .

As described above, in the machining method of the present invention, by utilizing this elliptical vibration, a corner portion can be created with high accuracy by cutting even in a plurality of tool paths or continuous tool paths. The elliptical vibration is described in Japanese Patent No. 3500344, and is generated on the micron order using ultrasonic waves.
Although the corner portion has been described above, the corner portion is a portion of the corner portion. Therefore, if the corner portion is created with high accuracy as described above, the corner portion is also created with high accuracy.

In the machining according to the present invention, if a feeding motion is added to the above-described cutting motion, a surface forming a corner can be created at the same time.
For example, as shown in FIG. 4, the three-dimensional shape shown in FIG. 1 is fed with a feed motion (a plurality of tool paths along contour lines or a tool path connected in a spiral shape) in addition to the cutting motion. By giving, a surface having a shape along the feeding movement can be created. In FIG. 4, when each tool path is viewed in the corner ridge line direction in the vicinity of the corner, cutting is performed as shown in FIG. Since the surface is formed by transferring the shape of the cutting edge of the tool in the feed movement direction, as shown in FIG. If a plane can be created and the feed movement is made curved using an R bite, a curved surface can be created as shown in FIG. This is the same as in the case of open three-dimensional cutting.

B. Example of Manufacturing Reflex Reflector Mold According to the above-described processing method of the present invention, by accurately transferring the shape of the tool blade edge as it is, a highly accurate corner or corner can be created as the sweep shape.
Therefore, as an example, a manufacturing example of a reflex reflector mold manufactured by finishing three surfaces simultaneously with one continuous tool path will be described below.

FIG. 5 shows a state immediately after the formation of one closed recess 3 in the metal body 1 having a flat block-like upper surface. In this recess 3, three triangular surfaces 5, 7, 9 that are orthogonal to each other are configured as mirror surfaces, and the ridges between adjacent surfaces of the three surfaces 5, 7, 9 become corner corners 11, 13, 15. ing.
The recess 3 is formed by cutting with a cutting tool 21.

As shown in FIG. 6, a rake face 23 is formed at the cutting edge of the tip of the cutting tool 21. The rake face 23 is a flat surface in which main cutting edge ridge lines 27 and 29 extending in a V shape from the tip 25 are present on both sides, and a flank face sandwiching the inclined ridge line 31 on the lower surface of the tool. 33 and 35 are formed.
The shape of the cutting edge portion of the cutting tool 21 corresponds to the concave portion 3 formed in the metal body 1 shown in FIG. 7, and the cutting edge where the main cutting edge ridge line portions 27 and 29 intersect as shown in a partial cross-sectional view thereof. The angle α corresponds to the groove angle θ (0), the inclination angle β of the main cutting edge ridge line portion 27 corresponds to the inclination angle θ (1) of the surface 5 on one side, and the inclination angle of the main cutting edge ridge line portion 29. γ corresponds to the inclination angle θ (2) of the other surfaces 7 and 9.

  As shown in FIG. 8, the cutting tool 21 is held in a posture with respect to the metal body 1. In this posture, a clearance angle ε is formed on the rear side in the traveling direction. In the posture described above, ultrasonic elliptical vibration as shown by an arrow is given to the cutting tool 21. This elliptical vibration surface is a surface between a surface including the cutting direction and the direction of the cutting thickness and a surface including the cutting direction and the ridge line direction of the cutting edge. Further, the elliptical vibration surface has a direction in which the flank surfaces 33 and 35 are separated from the cut new surface.

When the tip 25 of the cutting edge of the cutting tool 21 is fed into the metal body 1 and advanced while maintaining the above posture, the main cutting edge ridge line 27, the leading edge 25, and the main cutting edge ridge line 29 are continuous. The finished contour is transferred to the metal body 1.
The tool path P indicated by the arrows in FIGS. 5 and 7 is capable of continuous one-pass (one-stroke writing). When the cutting tool 21 is advanced along the tool path P, as shown in FIG. The sweep shape which is the movement trajectory of the contour is created as the concave portion 3.

A ridge line portion is created by the movement trajectory of the contours of the leading edge portion 25 of the blade edge portion and the main cutting edge ridge line portions 27 and 29 sandwiching it. This ridge portion becomes the corner portions 11 and 13 of the recess 3.
Since the main cutting edge ridge line portion 27 is set so as to exist on the surface including the tool path P, one surface 5 is created by the movement locus of the contour. Moreover, since the main cutting edge ridge line portion 29 intersects the surface including the tool path P and the tool path P is bent, the two surfaces 7 and 9 are created by the movement trajectory of the contour. A corner 15 is created at the ridge between 7 and 9.
Therefore, in the recessed part 3, the triangular three surfaces 5, 7, and 9 orthogonal to each other are created, and each ridgeline is a corner part. The created three surfaces 5, 7, and 9 are mirror surfaces, and no “polishing” that causes errors is required.

In addition, although the recessed part 3 is manufactured by one cutting in the above, the frequency | count is not limited. Therefore, when it is desired to deepen the concave portion 3, the tool may be fed little by little in the depth direction of the concave portion 3 and processed by a plurality of times of cutting (a plurality of tool paths).
Moreover, even if the three sides are not finished at the same time, as shown in FIG. 3 (1), the finish may be divided into three times for each side, as shown in FIG. 3 (2). Only the second side may be finished.

When a large number of the recesses 3 are arranged, a reflex reflector mold 37 as shown in FIG. 10 is obtained.
The mold 37 shown in FIG. 10 above is one in which a retroreflective shape of an orthogonal trihedron is created on the plane of the metal body 1, but the tool posture of the cutting tool 21 is tilted as shown in FIG. It is possible to create a free-form surface by proceeding to.

The embodiment of the present invention has been described in detail above. However, the specific configuration is not limited to this embodiment, and the present invention can be changed even if there is a design change without departing from the gist of the present invention. included.
For example, in the above-described embodiment, the workpiece is not limited to a metal body and may be any material that can be cut, such as an amorphous Ni-based coating layer or glass, and further, a cemented carbide or SiC. Ceramics are also included.

  The corner corner processing method of the present invention is particularly suitable for implementation in a mold manufacturing industry that requires a highly accurate corner angle.

DESCRIPTION OF SYMBOLS 1 ... Metal body 3 ... Concave part 5, 7, 9 ... Surface 11, 13, 15 ... Corner corner part 21 ... Cutting tool 23 ... Rake face 25 ... Tip part 27, 29 ... Main cutting edge ridgeline part 31 ... Ridge line part 33, 35 ... Flank α ... Cutting edge angle β, γ ... Tilt angle ε ... Flank angle θ (0) ... Groove angle θ (1), θ (2) ... Tilt angle

Claims (10)

  In the processing method of corners and corners included in recesses closed by cutting, the cutting tool is caused to perform a cutting motion relative to the work material while applying an elliptical vibration so as to have a motion component in the cutting direction. A characteristic processing method. In the processing method of the corner | angular part and corner | corner corner part described in Claim 1,
A machining method characterized by continuously making a cutting motion while changing a cutting direction. In the processing method of the corner | angular part and corner | corner corner part described in Claim 1 or 2,
A machining method characterized by performing a cutting motion while applying an elliptical motion in a direction in which the flank faces away from the cut surface. In the processing method of the corner | angular part and corner | corner corner part in any one of Claim 1 to 3,
A machining method characterized in that in addition to a feed movement, a surface that forms corners and corners is simultaneously created by the feed movement. In the processing method of the corner | angular part and corner | corner corner part in any one of Claim 1 to 3,
A machining method characterized by using a cutting tool having a cutting edge portion having a cutting edge ridge line portion, and simultaneously creating a surface forming a corner portion by transferring a sweep shape of the contour of the cutting edge ridge line portion. In the processing method of the corner | angular part and corner | angular corner part described in Claim 5,
When forming a recess composed of three corners and one corner that are orthogonal to each other, a cutting tool having a cutting edge portion having a V-shaped cutting edge ridge line portion is used, and the cutting edge ridge line portion on one side is used as a tool. A machining method characterized by simultaneously finishing the three surfaces forming the corner and the corner by transferring the sweep shape of the contour of the cutting edge ridge line by cutting while adjusting to be present on the surface including the path . In the processing method of the corner | angular part and corner | angular corner part described in Claim 5 or 6,
A processing method characterized by forming a plurality of concave portions side by side on a flat surface or curved surface.   The manufacturing method of a metal mold | die provided with the process of forming the corner | angular part contained in a recessed part or a corner | angular part, and a corner | angular corner part using the method in any one of Claim 1-7.   A mold manufactured by the manufacturing method according to claim 8.   A molded product molded using the mold according to claim 9.