JPH0716828B2 - Extrusion die manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing an extrusion die, in particular, a bearing hole having a given shape is provided on the front surface side, and a back relief portion is formed from the bearing hole toward the back surface side. In a method for manufacturing an extrusion die, the bearing surface forming the inner peripheral surface of the bearing hole and the back escape inclined surface forming the back escape portion are formed by using a wire-cut electric discharge machine, and the back escape inclined surface is formed. In forming, so to speak, manufacturing of an extrusion die in which the tilt angle control and the cutting position control of the wire electrode in the wire cut electric discharge machining apparatus are controlled based on the shape of the bearing hole and the opening shape of the back relief portion. It is about the method.

Conventionally, as an extrusion die used for extruding an aluminum mold material, an extrusion die as shown in FIGS. 1A to 1C is known. FIG. 1 (A) is a plan view, FIG. 1 (B) is a side sectional view taken along arrow AA ′ in FIG. 1 (A), and FIG. 1 (C) is a bottom view. Reference numeral 1 is a pouring portion, 2 is a bearing hole, 3 is a back relief portion, and 4 is a back relief step portion.

Generally, when a die material such as an aluminum sash is manufactured by an extrusion die, the aluminum material supplied to the pouring part 1 is pressed in the direction of the bearing hole 2 by a pressing device (not shown), Then, it is molded into a product of the back relief portion 3 and extruded. Therefore, in order to manufacture a mold material having a high shape accuracy, it is necessary to make the speed of the aluminum material passing through the bearing hole 2 uniform. Therefore, as will be described later with reference to FIGS. 2 and 3, the bearing length of the bearing hole 2 (arrow l shown in FIG. 1 (B)) is adjusted according to the shape of the bearing hole 2. Have been considered to. Hereinafter, the bearing length 1 will be described.

2 (A), (B), and (C) are cross-sectional views taken along the lines AA ', BB', and C-C 'shown in FIG. 1 (C), respectively, and FIG. 3 is a developed view of a bearing diagram. Is shown. Reference numerals 2 to 4 in the figure correspond to those in FIG. 1, 5 is a bearing surface, and 6 is a back relief inclined surface.

As described above, the bearing length 1 (shown in FIG. 1B) in the bearing hole 2 is predetermined corresponding to the shape of the bearing hole 2. That is, the bearing length lc is large as shown in FIG. 2 (C) in the wide groove portion of the bearing hole 2 and its adjacent portion as indicated by the arrow de in FIG. 1 (C). , And in the narrow groove portion such as between the arrows bc and fg shown in FIG. 1 (C),
Bearing length lb as shown in FIG. 2 (B)
Has been made smaller. Furthermore, even if the groove width is the same,
At the end portion of the bearing hole 2 as indicated by the arrow ha in the figure (C), the flow of the aluminum material deteriorates, so that the bearing length la becomes smaller as shown in the figure 2 (A). Is being done. The bearing surface 5 formed in this way looks like the developed view shown in FIG. The arrows a to h in the figure correspond to the positions indicated by the arrows a to h in FIG.

The bearing hole 2 and the back relief portion 3 in the conventional extrusion die described above are usually processed by the above-mentioned bearing hole 2
The bearing surface 5 is formed by a wire cut electric discharge machine, and the back escape step 4 and the back escape inclined surface 6 of the back escape portion 3 are formed by using a normal electric discharge machine or a machine tool such as a milling cutter. There is. It is to be noted that it is necessary to machine the back relief step portion 4 only when the bearing surface 5 and the back relief inclined surface 6 are machined.
This is because it is difficult to finish b, lc and ab, cd, ef, gh between ab in FIG. 3 with high precision. Therefore, in manufacturing the conventional extrusion die,
The following problems existed.

(I) The manufacturing process is complicated, and the workpieces must be accurately aligned in each manufacturing process.

(Ii) As described above, if the back relief portion 3 is formed by an ordinary electric discharge machine, it is necessary to manufacture a machining electrode used for machining, and moreover, various kinds of machining electrodes manufactured with high accuracy are required. Needed. In addition, when processing with a milling machine or the like, it is necessary to perform processing with high precision, and thus a high level processing technique is required.

(Iii) It is difficult to perform high-precision machining because there is electrode wear in the case of electric discharge machining and swaying of the cutter in case of milling.

Due to the above-mentioned problems, the conventional extrusion die has a drawback that not only the number of manufacturing steps is large, but also the manufacturing cost is high. Further, as described above, since the back relief step portion 4 is provided, the bearing hole 2
The mechanical strength of the peripheral portion of the bearing becomes weak, and in particular, the peripheral portion of the bearing hole 2 shown in FIG. It was

The present invention aims to solve the above drawbacks,
A manufacturing device that combines a wire-cut electric discharge machine and, for example, a milling machine, automates the entire machining of the bearing hole and the back relief while the workpiece is first placed on the processing table of the manufacturing machine. By doing
It is an object of the present invention to provide a method for manufacturing an extrusion die that can significantly reduce the manufacturing man-hours, reduce the manufacturing cost, improve the mechanical strength, and manufacture a highly accurate product. Hereinafter, description will be given with reference to the drawings.

4 to 6 are explanatory views each for explaining an extrusion die manufactured based on the manufacturing method of the present invention, and FIG. 7 is an example of a manufacturing apparatus used for carrying out the manufacturing method of the present invention. FIG. 8 is an explanatory view for explaining a manufacturing method which has been already proposed by the applicant of the present application and is a premise of the present invention, and FIG. 9 is a drawing for explaining the manufacturing method of the present invention. FIG.

Each embodiment of the extrusion die of the present invention described below relates to an extrusion die corresponding to the conventional example shown in FIGS. 1 to 3 described at the beginning of the specification of the present application, and the reference numerals in the drawings
2, 3, 5, and 6 correspond to FIGS. 1 and 2, and 7 indicates a minute cut portion.

4 (A), (B) and (C) are shown in FIG.
A sectional view taken along line A ', B-B', C-C 'is shown in which all of the bearing surface 5 and the back relief inclined surface 6 are one of the extrusion dies of the present invention manufactured by using a wire-cut electric discharge machine described later. This is an example. The bearing surface 5 in the embodiment shown in FIG. 4 is processed in the same manner as in the conventional example described above, but the back escape inclined surface 6 forming the back escape portion 3 also has the inclination angle and / or the traveling position of the wire electrode changed. It is machined by using the same wire-cut electric discharge machine by controlling according to the shape of the bearing hole 2 (manufacturing method will be described in detail later). Therefore, the fourth aspect of the present invention
The embodiment shown in the drawing is provided with a bearing hole 2 having a desired bearing surface 5 as shown in the developed view of FIG. 3 without providing a back relief step portion 4 (shown in FIG. 2) as in the conventional example described above. It is an extrusion die.

In the embodiment shown in FIG. 4, the back escape inclination is controlled while controlling the inclination angle and / or the traveling position of the wire electrode in order to make the speed of the aluminum material passing through the bearing hole 2 uniform. By cutting the surface 6, for example, as shown in FIG. 3, the bearing length at each predetermined position corresponding to the shape of the bearing hole 2 (for example, arrow la shown in FIG. 3). , lb, lc, etc.) are formed. However, it may be necessary to correct the bearing length of the bearing surface 5 as a result of actually extruding the product using the extrusion die manufactured in this way.
The correction value of the bearing length is minute, and is usually performed by using a file or the like. For that purpose, the line of intersection between the bearing surface 5 and the back clearance inclined surface 6 must be visible. However, in the embodiment shown in FIG.
Since the inclination angle of the back clearance inclined surface 6 is small, there is a problem that it is difficult to accurately visually check the line of intersection between the back clearance inclined surface 6 and the bearing surface 5. Also,
When manufacturing a mold using the extrusion die of the embodiment shown in FIG. 4, depending on the nature of the extruded material, the extruded material may be fixed to the intersection line between the bearing surface 5 and the back clearance inclined surface 6. is there. This causes the product to be flawed and reduce the product value. As an extrusion die capable of solving the above problems, another embodiment of the extrusion die of the present invention will be described with reference to FIG.

In the embodiment shown in FIG. 5, as in the embodiment shown in FIG. 4, after the processing of the back clearance inclined surface 6 is completed, the back clearance inclined surface 6 is formed at the line of intersection between the bearing surface 5 and the back clearance inclined surface 6. A fine cut 7 is made by making a fine cut in the above-mentioned range in which the extruded material can be prevented from sticking, for example, 0.2 to 1.0 mm, and then the above-mentioned embodiment shown in FIG. 4 is performed. This is an extruding die that forms the bearing surface 5 as in the example (the manufacturing method will be described later in detail). 5 (A), (B), and (C) are the same as those in FIG. 4, and are similar to those in FIG. 1 (C).
The sectional view in B ', CC' is shown. Also, the fifth
FIG. 6D is a sectional view taken along the arrow D (corner of the bearing hole) shown in FIG. The developed view of the bearing surface 5 in the embodiment shown in FIG. 5 can be represented in the same manner as in FIG. Further, at the angle of the bearing hole 2 of the embodiment shown in FIG. 5 (for example, the arrow D shown in FIG. 1C), the minute cutout portion 7 is provided as shown in FIG. 5D. Absent. This is due to a manufacturing method described later, but since the bearing surface 5 does not need to be corrected at the intersection of the bearing surface 5 and the back clearance inclined surface 6 at the above-mentioned angle, the minute cut portion 7 is not necessary. Has not been made. Further, since the pressing force applied to the corner portion is larger than that of the other portions, the fact that the minute cut portion 7 is not provided leads to the reinforcement of the corner portion.

Further, FIG. 6 shows a development view of a bearing surface in another embodiment of the extrusion die of the present invention. The embodiment shown in FIG. 6 also has a bearing hole 2 having the same shape as that of the embodiment shown in FIG.
The sectional view taken along B'corresponds to FIG. 5 (B), and the sectional view taken along CC 'corresponds to FIG. 5 (C). Further, the cross-sectional view of each corner portion, which is representatively shown by the arrow D, corresponds to FIG. 5 (D). As is clear from these sectional views, the embodiment shown in FIG.
It has the same structure as the illustrated embodiment. As described above, the flow velocity of the aluminum material in the bearing hole 2 varies depending on the shape of the bearing hole 2, and in particular, in consideration of the fact that it becomes slow at the corners, it is clear from the diagrammatic development view in the embodiment shown in FIG. In addition, the bearing length at the corners D, D, ... Is reduced.

Although the respective examples of the extrusion die of the present invention have been described above, prior to the description of the method for producing these extrusion dies,
A manufacturing apparatus used for manufacturing the extrusion die of the present invention will be described with reference to FIG. In FIG. 7, reference numeral 8 in the drawing is a machining table, 9 and 10 are control motors for driving the machining table 8 in the orthogonal X and Y directions, 11 is a workpiece, 12 is a wire electrode, 13 is a wire electrode supply roller, 14 and 17 are tension rollers, 15 is an upper guide, 16 is a lower guide, 18 is a scraper roller, 19
Reference numerals 20 and 20 are control motors for adjusting the tilt angle of the wire electrode 12 by moving the upper guide 15 in the orthogonal X and Y directions, 21 is a milling head, 22 is a milling cutter, and 23 is a control. Motor for milling head
It represents the one that controls 21 feeds.

The manufacturing apparatus shown in FIG. 7 is a combination of a wire cutting electric discharge machine and a milling machine in order to manufacture the extrusion die of the present invention. Both the wire cutting electric discharge machine and the milling machine are good. Since it is known, I will only give a brief explanation.

In FIG. 7, the processing table 8 is a control motor 9 and
It is moved by 10 in the orthogonal X and Y directions. The wire electrode 12 for cutting and processing the workpiece 11 placed on the processing table 8 is from the wire electrode supply roller 13 to the tension roller.
14, upper guide 15, lower guide 16, tension roller
It is wound on a scraper roller 18 via 17. Then, the wire electrode 12 between the upper guide 15 and the lower guide 16 is tensioned by the tension rollers 14 and 17 and is made to travel in a straight line state. Further, since the upper guide 15 is configured to be moved in the X and Y directions orthogonal to each other by the control motors 19 and 20, the inclination angle of the wire electrode 12 between the upper guide 15 and the lower guide 16 is increased. Can be adjusted as desired. Therefore, if the workpiece 11 placed on the processing table 8 is cut linearly, desired cutting can be performed. Further, with the milling head 21 set on the same bed, machining which is difficult with the above-mentioned wire-cut electric discharge machine (for example, machining of the minute cut portion 7 described above) is controlled by controlling the feed of the milling cutter 22. Motor 23 and X of the processing table 8 above,
By controlling the control motors 9 and 10 for driving in the Y direction, it is possible to perform desired milling or jig grinder processing in which the milling cutter 22 is replaced with a grinding wheel. Also, the above milling heads
It is also possible to provide a normal electric discharge machining head (not shown) in place of 21 and perform electric discharge machining using the electric discharge machining head.

The manufacturing apparatus described above is driven by, for example, NC control for performing processing in accordance with a predetermined program, and includes the bearing hole 2 and the back clearance portion 3 of the extrusion die of the present invention described above. All processing is done automatically. Since the relative positional relationship between the center of the milling cutter 22 and the wire electrode 12 is predetermined, the wire cutting electrical discharge machining and the milling can be continuously and automatically performed. In addition, the program is the shape of the bearing hole 2 to be machined, the bearing length of the bearing surface 5 in the bearing hole 2,
Information about the inclination angle of the back escape inclined surface 6 and the cut amount of the minute cut portion 7 in the back escape portion 3 is given,
It can be considered that it is determined by an operation performed based on these pieces of information.

Next, prior to the explanation of the manufacturing method of the present invention using the above manufacturing apparatus, the manufacturing method of the extrusion die already proposed by the applicant of the present application (Japanese Patent Application No. 58-182319) is related to FIG. And explain. The already proposed manufacturing method is the premise of the manufacturing method of the present invention, and is the same as the manufacturing method of the present invention, except for the control mode when processing the back relief inclined surface 6. You can think. Therefore, the above-mentioned proposed manufacturing method will be described in detail below.

The extrusion die is in a state excluding the processing of the bearing hole 2 and the back relief portion 3 described above, that is, in the example shown in FIG. 1, a state in which the front surface, the back surface, the spigot portion and the outer peripheral surface of the extrusion die are finished (this specification). In this, the extrusion die in this state is referred to as a work piece) and is manufactured by machining in advance. Then, the workpiece 11 is processed into the bearing hole 2 and the back relief portion 3 by the above-described manufacturing apparatus to manufacture an extrusion die as shown in the embodiment shown in FIGS. 4 to 6.

First, a method of processing the bearing hole 2 and the back relief portion 3 in the embodiment shown in FIG. 4 will be described. The work piece
The front surface of 11 is in contact with the upper surface of the processing table 8 of the manufacturing apparatus shown in FIG. 7 (the state in which the bearing hole 2 to be processed is located below and the back relief portion 3 is located above as shown in FIG. 8). Then, the workpiece 11 is placed on the processing table 8. Then, as shown in FIG. 8 (A), the position and inclination angle of the wire electrode 12 are controlled by NC control by a predetermined program so that the machining allowance of the bearing surface 5 (dotted line in the drawing) is left. While doing so, cutting processing by wire cut electric discharge machining is performed. The program in the NC control is given information on the shape of the bearing hole 2, the bearing length l of the bearing surface 5 at each position of the bearing hole 2, and the inclination angle of the back clearance inclined surface 6 at each position, It is determined by calculation based on these information. FIG. 8D shows an embodiment of the NC control. The embodiment is a case in which the back escape inclined surface 6 is processed with a constant inclination angle θ. Therefore, in this case, the desired back relief inclined surface 6 can be processed by controlling the position of the wire electrode 12. That is, as the information on the shape of the bearing hole 2, for example, the coordinates of the arrow P of the bearing surface 5 to be machined are given and the bearing length l ₁ at each coordinate point is given. As a result, as shown in FIG. 8D, the coordinates of the position of the wire electrode 12 corresponding to the point P (point P _{1 in the} figure) is obtained based on the following equation.

t ₁ = l ₁ cotθ (1) If the position of the wire electrode 12 is controlled based on the coordinates of the point P ₁ obtained based on the above equation (1), the wire electrode 12 will be The desired intersection of the bearing surface 5 and the back clearance inclined surface 6 (see arrow ▲ P ^{′ in} FIG. 8 (D))
₁ ) can be passed.

Further, when the bearing length l ₂ is given, the coordinates of the point P ₂ shown in the figure corresponding to the point P can be obtained based on the following equation.

t ₂ = l ₂ cotθ (2) If the position of the wire electrode 12 is controlled based on the coordinates of the point P ₂ obtained based on the above equation (2), the wire electrode 12 The desired intersection of the bearing surface 5 and the back clearance inclined surface 6 (see arrow ▲ P ^{′ in} FIG. 8 (D))
₂ ▼ point) can be passed.

The control mode in the case where the inclination angle of the wire electrode 12 is set to the predetermined angle θ (the angle θ is preferably in the range of 2 ° to 7 °) has been described above. It may be controlled. The control of the inclination angle θ gives, for example, information about the shape of the bearing hole 2 and the bearing length 1 of the bearing surface 5 at each position of the bearing hole 2, and the opening shape of the back relief portion 3, that is, the die. This is automatically performed by giving information about the shape of the intersecting line between the back surface of the back side and the back clearance inclined surface 6.

In this way, the desired back relief inclined surface 6 is formed by cutting the wire electrode 12 along the shape of the bearing hole 2. After the processing,
It goes without saying that the free block 11 'that has become free from the workpiece 11 is eliminated.

Next, a process of processing the bearing hole 2 will be described. In the processing step, the wire electrode 12 is attached to the processing table 8 (shown in FIG. 7) as shown in FIG. 8 (B).
The cutting process is performed while controlling the position of the wire electrode 12 on the basis of the coordinates corresponding to the shape of the bearing hole 2 which is already given (the coordinates of the arrow P point in FIG. 8 (D)). By performing the above, the extrusion die of the embodiment shown in FIG. 4 can be manufactured. That is, at each position of the inner peripheral surface of the bearing hole 2 (that is, the bearing surface 5), a desired bearing length 1 is provided (for example, the arrows ▲ P ^' ₁ ▼ and ▲ P ^' ₂ ▼ shown in FIG. 8D). It is possible to manufacture an extrusion die in which the bearing surface 5 and the back clearance inclined surface 6 directly intersect each other.

Next, the manufacturing method of the embodiment shown in FIG. 5 will be described. In the embodiment shown in FIG. 5, the minute cut amount Δt with respect to the back clearance inclined surface 6 at the intersection line between the bearing surface 5 and the back clearance inclined surface 6 in the embodiment shown in FIG. 4 described above.
The cutting process shown in FIG. 8 (C) is performed. The cutting process is performed under the condition that the extrusion die is placed on the processing table 8 as it is after the processing of the back relief inclined surface 6 described in the structure method of the embodiment shown in FIG. This is done by means of the milling cutter 22 shown in FIG. After that, the bearing surface 5 is processed. This is because it is possible to remove burrs generated by the cutting process. In addition,
The workpiece 11 and the milling cutter in the cutting process
Information on relative position control with respect to the cutter 22, that is, the shape of the bearing hole 2 (the arrow P shown in FIG.
Since the coordinates and the bearing length l) have already been given and the information regarding the above-mentioned depth of cut Δt is also given, the desired minute cut 7 can be formed.
Further, FIG. 8 (E) shows a relative movement mode between the milling cutter 22 and the workpiece 11 in the cutting process. That is, the milling cutter 22 moves with respect to the workpiece 11 in the direction of the arrow in the figure. Further, as is apparent from the illustrated mode, the cutting edge of the milling cutter 22 moves so as to come into contact with the corner D at the corner D, so that the cutting is not performed at the corner D. Absent. In this way, the extrusion die of the embodiment shown in FIG. 5 is manufactured. In the description of the manufacturing method of the embodiment shown in FIG. 5, it is stated that the back relief inclined surface 6 is processed in the same manner as in the embodiment shown in FIG. 4, but the inclination angle of the back relief inclined surface 6 is made constant. Moreover, after performing the process corresponding to the maximum value of the bearing length l, the predetermined bearing surface 5 as shown in FIG. 3 may be formed by the cutting process.

Further, the extrusion die of the embodiment shown in FIG. 6 can be easily manufactured by using the manufacturing method of the embodiment shown in FIG. 4 and the embodiment shown in FIG. 5 together. That is, as described above, the embodiment shown in FIG. 6 is basically the same as the embodiment shown in FIG. 5, but the bearing length 1 at each portion D of the bearing hole 2 is shown in the developed view shown in FIG. It is made smaller as described. Such processing of the bearing surface 5 at the corner D has been described above because the bearing length 1 at the corner D is given in the processing of the back relief portion 3 in the embodiment shown in FIG. By controlling the position of the wire electrode 12 and the inclination angle θ, the bearing surface 5 of the corner portion D having the desired bearing length 1 can be formed. In this way, the extrusion die of the embodiment shown in FIG. 6 is manufactured.

Although the bearing surface 5 is machined by the wire-cut electric discharge machine in the description of the manufacturing method, it may be machined by the milling machine, the jig grinder machine, or the normal electric machine. . In addition to the milling, the cutting may be performed by the jig grinder processing or the usual electric discharge machining.

In the previously proposed manufacturing method described above, similarly to the manufacturing method of the present invention described later, the workpiece 11 is first placed on the processing table 8 and the above-described FIGS. Any of the illustrated embodiments can be manufactured completely and can be processed automatically by NC control as described above, so that the number of processing steps can be greatly reduced and the accuracy can be improved. It becomes possible to manufacture a high extrusion die. In particular, since the performance related to the machining speed in the wire-cut electric discharge machine has been greatly improved recently, most of the machining is performed by the wire-cut electric discharge machining in both the proposed manufacturing method and the manufacturing method of the present invention described later. Therefore, the manufacturing time of the extrusion die is significantly shortened as compared with the conventional manufacturing method.
However, in the previously proposed manufacturing method described above,
When processing the back clearance inclined surface 6, if the cutting angle control and the inclination angle control of the wire electrode 12 are performed, there is a problem that the control mode becomes very complicated. The manufacturing method of the present invention solves the problem, and makes it possible to easily control the inclination angle of the wire electrode 12. The control method of the present invention will be described below with reference to FIG. Reference numeral 23 'in the drawing represents a bearing hole shape line, 24 represents a back relief opening shape line, and 25 represents a virtual bearing hole shape line.

In FIG. 9, the bearing hole shape line 23 'indicates the shape of the bearing hole 2 to be molded as described above. That is, as described above, by moving the wire electrode 12 running in the direction perpendicular to the die front surface (arrow F in FIG. 9) along the bearing hole shape line 23 ', the bearing forming the bearing hole 2 is formed. The surface 5 will be formed. The points represented by the points P ', P', ... Show the bearing lengths at predetermined positions corresponding to the shape of the bearing hole 2, that is, the bearing hole shape line 23 '. (For example, the arrow la, lb,
(e.g., lc, etc.) represents a depth position point (hereinafter referred to as a bearing depth point) that is substantially equal to lc).

In addition, the back relief opening opening shape line 24 is the back relief portion 3 to be molded.
It can be considered that it represents the opening shape on the back surface of the die (arrow R shown in FIG. 9). The back relief opening shape line 24 and the virtual bearing hole shape line 25 are the profile drawn on the die back surface R when the wire electrode 12 passes through the bearing depth points P ′, P ′ ,. It can be considered to correspond to the profile drawn on the front surface of the die (arrow F shown in FIG. 9). The back relief opening shape line 24 and the virtual bearing hole shape line 25 are set at predetermined positions corresponding to the above-mentioned bare link hole shape line 23 'and the shape of the bearing hole 2 to be formed. This can be done arbitrarily based on the information about the bearing length.

Next, the manufacturing method of the present invention will be described. First, in the processing step of forming the back relief portion, the wire electrode 12 is moved along the back relief portion opening shape line 24 and the virtual bearing hole shape line 25 so as to move the wire electrode 12 as shown in FIG. 15 movements are controlled. That is, control is performed by a known NC. By doing so, a back relief inclined surface having a desired opening shape and capable of processing a desired bearing hole by a processing step of forming a bearing surface described later is formed. As described above, the inclination angle of the wire electrode 12 in the back relief processing step of the manufacturing method of the present invention is controlled by the wire electrode 12
Can be performed simply and accurately, for example, by NC control so as to pass through both the back relief opening shape line 24 and the virtual bearing hole shape line 25 set in advance. .

The bearing surface in the manufacturing method of the present invention is
This is performed in the same manner as the already proposed manufacturing method described above with reference to FIG. That is, in FIG. 9, the wire electrode 12 is made to run in a direction perpendicular to the die front surface F while the wire cutting is performed along the bearing hole shape line 23 '. At this time, the wire electrode 12 has a bearing depth point P'on the back relief inclined surface 6 (the surface indicated by the two-dot chain line in FIG. 9) formed by the above-described back relief processing step. , P ', ..., so that an extrusion die having a bearing hole 2 having a predetermined bearing length corresponding to each position is manufactured. That is, the extrusion die shown in FIG. 4 is manufactured.

Further, as in the embodiment shown in FIG. 5, the method for processing the minute cut portion 7 may be performed in the same manner as the already proposed manufacturing method described above with reference to FIGS. 8 (C) and 8 (E).

As described above, according to the present invention, a manufacturing apparatus in which a wire cut electric discharge machining apparatus and, for example, a milling machine are combined is used, and the workpiece is first placed on the machining table of the manufacturing apparatus. With this, it is possible to automate the entire processing of the bearing hole and the back relief part, and since it is possible to easily and accurately control the tilt angle of the wire electrode, the manufacturing man-hours are greatly reduced and the manufacturing cost is reduced. It is possible to provide a method for manufacturing an extrusion die that can reduce the mechanical strength and improve the mechanical strength and can manufacture a highly accurate product.

[Brief description of drawings]

1 (A), (B), (C), 2 (A),
(B), (C) and FIG. 3 are explanatory views for explaining a conventional extrusion die, and FIGS. 4 to 6 are explanatory views for an extrusion die manufactured according to the manufacturing method of the present invention. FIG. 7 is a block diagram of an embodiment of a manufacturing apparatus used to carry out the manufacturing method of the present invention, and FIG. 8 is a description of the manufacturing method already proposed by the applicant of the present application and which is the premise of the present invention. 9 and 9 are explanatory views for explaining the manufacturing method of the present invention. In the figure, 1 is a pouring portion, 2 is a bearing hole, 3 is a back relief portion, 5 is a bearing surface, 6 is a back relief inclined surface, 7 is a minute cut portion, 8 is a working table, 9, 10, 19, 20 and 23 is a control motor, 11 is a work piece, 11 'is a loose block, 12 is a wire electrode, 13 is a wire electrode supply roller, 14 and 17 are tension rollers, 15 is an upper guide, 16 is a lower guide, 18
Is a scraper roller, 21 is a milling head, 22 is a milling cutter, 23 'is a bearing hole shape line, 24 is a back relief opening shape line, and 25 is a virtual bearing hole shape line.

Claims (2)

[Claims] 1. A bearing hole having a given shape is provided on the front surface side, and a vertical bearing surface is formed from the front surface to the back surface so as to correspond to the bearing hole, and from the bearing surface to the back surface. A method for manufacturing an extrusion die in which a back relief portion is formed, and the bearing surface at each position on the front surface of the bearing hole on the line of the bare rig hole has a bearing length that is predetermined based on the shape of the bearing hole. In the above, there is a machining step of forming the bearing surface with a wire cut electric discharge machine having a wire electrode that travels in a direction perpendicular to the front surface, and The back relief is formed by a wire-cut electric discharge machine with a wire electrode that runs with a variable minute angle. In the processing step of forming the back relief portion, a back relief opening opening shape line formed by the back relief portion is set on the back surface, and the wire electrode is to be processed into the bearing. From the first point on the back relief opening shape line to the bearing length, in order to ensure that a position on the inner circumference of the hole passes through a depth position point equal to the bearing length corresponding to that position. A second point where a straight line passing through equal depth position points intersects the front surface is set, and a virtual bearing hole shape line corresponding to the locus of the second point is defined on the front surface, and the wire electrode is While passing through the first point and the second point, control is given so as to follow the back relief opening shape line and the virtual bearing hole shape line, and the minute angle inclined surface of the back relief portion is processed. It is characterized by doing Method of manufacturing the extrusion die. 2. In the processing step of processing the back relief portion, after the fine angle inclined surface is processed, a cut is made in the fine angle inclined surface at a depth position equal to the bearing length corresponding to each position. The method for producing an extrusion die according to claim 1, wherein the extrusion die is processed.