JPS60114427A - Manufacturing method of extrusion dies - Google Patents

Abstract

PURPOSE:To raise the processing efficiency, by performing a cutting work, as the cutting line passes a point which indicates the depth which is equal to the bearing length when a back relief inclined surface is formed and after that, processing the bearing surface. CONSTITUTION:When a back relief inclined surface 6 is formed, a cutting processing is performed as controlling the position and the angle of inclination of a wire electrode 12, as a margin to process of a bearing surface 5 is left. That is, the position of the wire electrode 12 is calculated, according to values of coordinates of P of the bearing surface 5 which is to be processed, and the bearing length l1. Next, when the bearing surface 5 is processed, the processing is performed as the depth of cut formed by the wire electrode 12 is not deeper than the cut width DELTAd. In this way, man-hours required in the process of manufacture can be drastically decreased, and the precise processing can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an extrusion die, in particular, a bearing surface forming the inner circumferential surface of a bearing hole having a given shape and a back relief inclined surface forming a back relief portion are formed by wire cut electric discharge. A method of manufacturing an extrusion die in which the bearing surface is formed using a processing device, wherein the processing to form the bearing surface is performed so that the amount of one cut of the wire electrode does not exceed the cutting width of the wire electrode. The present invention relates to a method for manufacturing an extrusion die that avoids generation of scrap (loose pieces separated from a workpiece) during bearing surface machining by repeating machining.

2. Description of the Related Art Conventionally, extrusion dies such as those shown in FIGS. The first view shows a plan view, the first view shows a side sectional view taken along the arrow A-A', and FIG. 1cI shows a bottom view.

In the figure, numeral 1 is the pouring part, and 2 is the bearing hole.

3 represents a back relief part, and 4 represents a back relief step part.

Generally, when producing a shaped material such as aluminum sash using an extrusion die, the aluminum material supplied to the pouring section 1 is pressed in the direction of the bearing hole 2 by a suppressor (not shown), and is molded by the bearing hole 2. The product is then extruded into the back relief part 3 as a product. Therefore, in order to manufacture a molded material with 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, consideration has been given to adjusting the bearing length of the bearing hole 2 (arrow Q in FIG. 1cI) in accordance with the shape of the bearing hole 2. ing. The bearing length 2 will be explained below.

Figure 2 (8), IBl, tel are respectively Figure 1 1c+
Illustration A-A'.

The cross-sectional views taken along lines BB' and CC' and FIG. 3 show a developed view of the bearing surface. Reference numerals 2 to 4 in FIG. 9 correspond to those in FIG. 1, 5 represents a bearing surface, and 6 represents a back relief inclined surface.

As described above, the bearing length 2 (shown in FIG. 1cI) in the bearing hole 2 is predetermined in accordance with the shape of the bearing hole 2. That is.

In the wide groove part of the bearing hole 2 and its adjacent part, as shown between the arrows dg in Fig. 1cI, the teeth 2fc
As shown in Figure 1, the bearing length 2G is large, and in the narrow part of the groove, such as between the arrows bc and 19 in Figure 1cI, the bearing length is increased as shown in Figure 2+Bl. has been made smaller. Furthermore,
Even if the groove width is the same, the flow of the aluminum material is poor at the end of the bearing hole 2, as shown between the arrows te and ha in Figure 1, so the bearing The length k is made smaller.The bearing surface 5 formed in this way is
It will look like the developed view shown in the figure. Note that the arrows α to h in FIG. 1 correspond to the positions indicated by the arrows α to h in FIG. 1cI.

In the conventional extrusion die described above, the bearing hole 2 and the back relief part 3 are processed in two steps.
The bearing surface 5 is formed using a wire-cut electric discharge machining device, and the back relief stepped portion 4 and the back relief inclined surface 6 of the back relief portion 3 are formed using a machine tool such as an ordinary electric discharge machine or a milling cutter. . The necessity of machining the back relief stepped portion 4 means that machining of the bearing surface 5 and the back relief inclined surface 6 alone will not meet the bearing length fla mentioned above.
, flb, Qc and tree 3 diagrams between ah+cd
This is because it is difficult to accurately finish the gap + g / gap + gh. Therefore, the following problems have existed in manufacturing conventional extrusion dies.

(jJ The manufacturing process is complex, and the workpiece must be accurately aligned for each manufacturing process.

(11) As mentioned above, if the back relief part 3 is to be formed using a normal electric discharge machining device, it is necessary to manufacture a machining electrode used for machining, and moreover, it requires many types of machining electrodes that are manufactured with high precision. be done. Also.

When processing with a milling cutter or the like, the processing must be performed with high precision, so advanced processing technology is required.

(High-precision machining is difficult because of electrode wear in curved electrical discharge machining and cutter runout in milling.

Due to the above-mentioned problems, conventional extrusion dies not only require a large number of manufacturing steps.

The drawback was that the production cost was also high. Also.

As mentioned above, since the relief step 4 is provided, the mechanical strength of the surrounding area of the bearing hole 2 is weakened, especially the thin walled area of the surrounding area of the bearing hole 2 shown in the second prisoner. In.

It also had the disadvantage of being susceptible to damage such as deformation and cracking.

Further, in electrical discharge machining using a wire-cut electrical discharge machining device, it is common for a part of the workpiece to be cut off and scrap to be produced. Immediately before the scrap is separated from the workpiece, the connecting portion between the scrap and the main body of the workpiece becomes smaller, so the scrap moves under its own weight.

Undesirable contact between the scrap and the wire electrode occurs, resulting in unstable processing conditions. Therefore.

Temporarily suspend processing and forcibly remove the above scraps,
Processing must be started again. Therefore, in order to prevent the above-mentioned undesirable situation from occurring, many means have been proposed for holding the scrap so that it does not move. However, these proposals are effective when the above-mentioned scrap has a large volume, but there is a problem in that it is difficult to hold scrap with a small volume.

The present invention aims to solve the above-mentioned drawbacks and problems at the same time.The present invention aims to solve both the above-mentioned drawbacks and problems. By performing the entire machining of the relief part and repeating the machining so that the cutting depth of the wire electrode does not exceed at least the cutting width by the wire electrode, especially when machining the bearing hole, the generation of scrap is prevented. It is possible to completely automate all the machining of the bearing hole and the back relief part, thereby significantly shortening the manufacturing man-hours and reducing the manufacturing cost.

It is an object of the present invention to provide a method for manufacturing an extrusion die that improves mechanical strength and allows manufacturing of highly accurate products. This will be explained below with reference to the drawings.

4 to 6 are explanatory diagrams for explaining extrusion dies manufactured based on the manufacturing method of the present invention, respectively, and off-line diagrams are one implementation of the manufacturing apparatus used to carry out the manufacturing method of the present invention. EXAMPLE CONFIGURATION FIGS. 8 to 10 show explanatory diagrams for explaining the manufacturing method of the present invention.

Each embodiment of an extrusion die manufactured according to the manufacturing method of the present invention described below is related 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. Reference numerals 2, 3.5, and 6 correspond to those in FIGS. 1 and 2, and 7 represents a minute cut.

Fang 4 device, IBl, (C1 shows a cross-sectional view at FIG. 1 (C1 diagram-A', s-B', CC')
All of the bearing surface 5 and back relief inclined surface 6 are an example of an extrusion die manufactured by the manufacturing method of the present invention described later using a wire cut electric discharge machining apparatus described later. The bearing surface 5 in the embodiment shown in FIG. 4 is machined in the same manner as in the conventional example described above, but
The back relief inclined surface 6 constituting the wire electrode is also machined using the same wire-cut electrical discharge machining device by controlling the inclination angle and/or running position of the wire electrode in accordance with the shape of the bearing hole 2 (manufacturing method (will be discussed in detail later). Therefore, the embodiment shown in FIG. 4 is a bearing having a desired bearing surface 5 as shown in the developed view in FIG. This is an extrusion die with holes 2.

In the embodiment shown in FIG. 4, in order to make the speed of the aluminum material passing through the bearing hole 2 uniform, the inclination angle and/or running position of the wire electrode is controlled as described above, and the above-mentioned escape slope is controlled. 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 is increased, for example, by the arrow Qα+ Qb+ IA shown in FIG.
C, etc.) is formed. However, based on the results of actually extruding a product using the extrusion die manufactured in this way, it may be necessary to correct the bearing length of the bearing surface 5. The correction value of the bearing length is small and is usually carried out using -. For this purpose, it is necessary that the line of intersection between the bearing surface 5 and the back relief inclined surface 6 be visible. However, in the embodiment shown in FIG. 4, since the angle of inclination of the back relief inclined surface 6 is minute, it is difficult to accurately visually observe the line of intersection between the back relief inclined surface 6 and the bearing surface 5. There is a problem that. In addition, when manufacturing a molded material using the extrusion die of the embodiment shown in v4, the extruded material may adhere to the intersection line between the bearing surface 5 and the relief slope surface 6 depending on the properties of the extruded material. This causes defects in the product and reduces the product value.As an extrusion die capable of solving the above problems, an extrusion die manufactured by the manufacturing method of the present invention is shown in FIG. Another embodiment of the extrusion die will be described.

In the embodiment shown in FIG. 5, after the machining of the back relief slope 6 is completed, as in the embodiment shown in FIG. 6
A fine notch 7 is formed by making a fine notch 7 in a range that is visible and correctable and can prevent the extruded material from sticking as described above, for example, about 0.1 to Losm, and then the process shown in FIG. 4 is carried out. This is an extrusion die in which a bearing surface 5 is formed similarly to the example (the manufacturing method will be described in detail later). In addition, tree diagram 5 (Al, IBl.

The tel is set in the same manner as in FIG. 4, and in FIG.
A.

Cross-sectional views taken along lines BB' and CC' are shown. 5+D) is a sectional view taken along the arrow D (the corner of the bearing hole) shown in FIG. 1 (q).The developed view of the bearing surface 5 in the embodiment shown in FIG. It can be expressed similarly to.Furthermore.

The corner portion of the bearing hole 2 in the embodiment shown in FIG.
In FIG. +C1 illustrated arrow D), the minute notch 7 is not cut as shown in FIG. 5 tD+. This is due to the manufacturing method described later, but the above-mentioned bearing surface 5 and back relief inclined surface 6 at the corner are
At the intersection with.

This is because there is no need to modify the bearing surface 5 mentioned above.

The minute cut portion 7 is not cut. Also.

Since the pressing force applied to the corners is stronger than that to other parts, the fact that the minute notches 7 are not formed leads to reinforcement of the corners.

Further, FIG. 6 shows a developed view of a bearing surface in another embodiment of an extrusion die manufactured by the manufacturing method of the present invention, which will be described later. It has a bearing hole 2 as shown in Fig. 6 and is shown in Fig. 2 A-A'
The cross-sectional view at B-B' corresponds to FIG. 5 IB+, and the cross-sectional view at C-σ corresponds to FIG. 5 tc1.
It corresponds to Further, the sectional view of each corner typically indicated by the arrow 1 corresponds to FIG. 5 tD+. As is clear from these sectional views, the structure is similar to that shown in FIG. 6. In addition, as mentioned above, the flow velocity of the aluminum material in the bearing hole 2 is
The length of the bearings in the embodiment shown in FIG. 6, D, .

Each embodiment of an extrusion die manufactured by the manufacturing method of the present invention has been described above.First, prior to explaining the manufacturing method of these extrusion dies, 1.Manufacture of an extrusion die manufactured by the manufacturing method of the present invention will be explained. The manufacturing equipment used for this will be explained with reference to off-line diagrams. In the off-line diagram, reference numeral 8 in FIG. 2 is a machining table, 9 and 10 are control motors, and X. 11 is a workpiece, and 12 is a wire electrode for driving in the Y direction.

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 scrap p-ra. Reference numerals 19 and 20 indicate control motors which are connected to the upper guide 15 at right angles. 21 is a milling head, 22 is a milling cutter, and 23 is a control motor that controls the feed of the milling head 21 by moving it in the Y direction to adjust the inclination angle of the wire electrode 12. There is.

The manufacturing equipment shown in the off-figure is one for manufacturing extrusion dies using the manufacturing method of the present invention.

This is a combination of a wire-cut electric discharge machining device and a milling device, and since both the wire-cut electric discharge machining device and the milling device are well known, a brief explanation will be provided.

In the off view, the processing table 8 is driven by control motors 9 and 10 in orthogonal X and Y directions. A wire electrode 12 for cutting a workpiece 11 placed on a processing table 8 is transferred from a wire electrode supply roller 13 to a tension roller 14 . Upper part ()'15. Lower guide 16.
Scrap roller 1 via tension roller 17
It is wound up at 8. The wire electrode 12 between the upper guide 15 and the lower guide 16 is connected to the tension
tensioned by rollers 14 and 17;
It is being driven in a straight line.

Further, the upper guide 15 is controlled by control motors 19 and 20.
The upper guide 15 and the lower guide 16
The inclination angle of the wire electrode 12 between the two can be adjusted as desired. Therefore, as long as the workpiece 11 placed on the processing table 8 is cut linearly, a desired cutting process can be performed. Furthermore, the control motor that controls the feed of the milling cutter 22 can perform machining that is difficult with the above-mentioned wire-cut electric discharge machining apparatus (for example, the machining of the minute notch 7 described above) by using the milling head 21 set on the same bed. 23 and the control motors 9 and 10 for driving the processing table 8 in the X and Y directions, a desired milling process or jig grinder process can be performed by replacing the milling cutter 22 with a grinding wheel. It is possible. Further, it is also possible to provide an ordinary electric discharge machining head (not shown) in place of the milling head 21 and perform electric discharge machining using the electric discharge machining head.

The manufacturing apparatus described above is driven by, for example, NC control to perform machining according to a predetermined program, and automatically performs all machining of the bearing hole 2 and back relief part 3 of the extrusion die of the present invention described above. This is done in a specific manner. In addition.

This is because the relative positional relationship between the center of the milling cutter 22 and the wire electrode 12 is predetermined.

It is possible to perform wire cut electrical discharge machining and milling continuously and automatically. The above program also includes the shape of the bearing hole 2 to be machined, the bearing length of the bearing surface 5 in the bearing hole 2, the inclination angle of the back relief inclined surface 6 in the back relief portion 3, and the cutting amount of the minute cut portion 7. It can be considered that the information is given and the decision is made by calculations performed based on this information. Hereinafter, a method for manufacturing an extrusion die according to the present invention using the above-mentioned manufacturing apparatus will be explained.
Explanation will be made in conjunction with the figure.

In the manufacturing method of the present invention, first, the state in which the bearing hole 2 and back relief portion 3 described above are not processed, that is, the front side of the extrusion die in the example shown in FIG.

It is manufactured in advance by machining in a state in which the back surface, a part of the spigot, and the outer peripheral surface are finished (in this specification, the extrusion die in this state is referred to as a workpiece). Then, the bearing hole 2 and the underside relief part 3 are machined in the workpiece 11 using the above-mentioned manufacturing apparatus to manufacture an extrusion die as shown in the embodiment shown in FIGS. 4 to 6.

First, the back relief inclined surface machining step in the manufacturing method of the present invention will be explained in relation to the O8 apparatus and tB1.

When processing the back relief inclined surface 6, the workpiece 11
The front surface of the O-8 is in contact with the upper surface of the machining table 8 of the manufacturing equipment shown in the diagram (the bearing hole 2 to be machined is located at the bottom and the back relief part 3 is located at the top as shown in the O-8 equipment). , the workpiece 11 is placed on the processing table 8. and.

As shown in Fig. 8 (5), the bearing surface 5 (
The position and inclination angle of the wire electrode 12 are set by NC according to a predetermined program so as to leave a machining allowance (dotted line in the figure).
Cutting is performed by wire-cut electric discharge machining under control. The above program in the NC control is as follows:
Shape of bearing hole 2.

Information regarding the bearing length of the bearing surface 5 at each position of the bearing hole 2 and the inclination angle of the back relief inclined surface 6 at each position is given, and is determined by calculation based on these information. FIG. 8 IBI shows an embodiment using the above NC control. Note that this embodiment is a case where processing is performed with the inclination angle θ of the back relief inclined surface 6 being constant. Therefore, in this case, by controlling the position of the wire electrode 12, a desired back relief inclined surface 6 can be processed. That is, as information regarding the shape of the bearing hole 2, for example, the coordinates of the illustrated arrow P of the bearing surface 5 to be machined are given, and the bearing length 21 at each of the coordinate points is given. As a result, as shown in FIG. 131, the coordinates of the position of the wire electrode 12 (point Pt shown by the arrow) corresponding to the point P can be found based on the following equation.

tl ” J tilJlθ ......Mountain...
... (1) The above point P determined based on the above equation (1)! If the position of the wire electrode 12 is controlled based on the coordinates of
1. It can be made to pass through the arrow P (point) shown in the figure.

Further, when the above-mentioned bearing length h is given, the coordinates of the 22 arrow points shown corresponding to the above-mentioned point P can be determined based on the following equation.

tl""2-θ・・・・・・・・・・・・(2)
If the position of the wire electrode 12 is controlled based on the coordinates of the point P2 determined based on the above equation (2), the wire electrode 12 can be moved to the desired bearing surface 5.
and the intersection with the back escape slope 6 (Fig. O8 + B1 arrow P
; point).

Above, we have explained the control mode when the inclination angle of the wire electrode 12 is set to a predetermined angle θ (the angle θ is preferably in the range of 2° to 7°). It may also be controlled. The inclination angle θ can be controlled by, for example, the shape of the bearing hole 2 and the bearing surface 5 at each position of the bearing hole 2.
This is automatically performed by providing information on the bearing length 2 of the back relief portion 3 and information on the shape of the opening of the back relief portion 3, that is, the shape of the line of intersection between the back surface of the die and the back relief inclined surface 6.

In this manner, by performing cutting using the wire electrode 12 along the shape of the bearing hole 2, a desired back relief inclined surface 6 is formed.

After the machining, the scrap 11' becomes free from the workpiece 11, but before the machining is completed, the "scrap holding device for wire-cut electrical discharge machining equipment (1978 The retention and removal of scrap 11' can be carried out automatically. Therefore, it is not only possible to prevent the processing condition from becoming unstable when scrap is released as explained at the beginning of this specification.

A transition to the subsequent bearing surface machining process can be performed automatically.

Next, the bearing surface processing step in the manufacturing method of the present invention will be explained in relation to the wood 9 device and fBl. In addition,
When machining bearing surface 5.

As shown in Fig. 9, the wire electrode 12 is made perpendicular to the processing table 8 (not shown), and the coordinates (not shown in Fig. 8) corresponding to the shape of the bearing hole 2 already given are By performing the cutting process while controlling the position of the wire electrode 12 based on the coordinates of the arrow point P, the desired bearing surface 5 can be processed. However, as shown in the apparatus E9, scrap 11' appears, and when the scrap 11N is released, an undesirable situation occurs in which the processing condition becomes unstable. Since the scrap 11'' is generally small, it is difficult to hold and remove it even with the scrap holding device used in the back relief slope machining process.

In the present invention, when machining the bearing surface, scraps are avoided as shown in Fig. 9 (IB). That is, scraps are generated by machining so that the depth of cut by the wire electrode 12 does not exceed at least the cutting width Δd, and by repeating the machining until the surface machined by the wire electrode 12 coincides with the bearing surface 5 to be formed. The bearing surface 5 is formed without any damage.

By the manufacturing method described above, that is, the back relief inclined surface machining process and the bearing surface machining process, the entire machining of the back relief part 3 and the bearing hole 2 of the extrusion die shown in FIG. 4 can be completely automated. In addition, although it was explained that the cutting position control of the wire electrode 12 in the above-mentioned bearing surface machining process is performed so that the maximum depth of cut at one time does not exceed the cutting width Δd, that is, so as not to generate scrap, the above-mentioned maximum depth of cut Even if the amount exceeds the cutting width Δd, it is sufficient as long as the generated scrap is blown away by the machining fluid sprayed during machining.

Next, a method of manufacturing the above-described embodiment shown in FIG. 5 will be explained. , the embodiment shown in FIG. 5 has a minute cut amount Δt with respect to the back relief slope 6 at the intersection line of the bearing surface 5 and the back relief slope 6 in the embodiment shown in FIG.
(10th rotation illustration).

The cutting process is.

After the above-mentioned machining of the back relief inclined surface 6 (as shown in FIG. 8) is completed, with the extrusion die placed on the machining table 8 as it is, it is cut by the milling cutter 22 shown in FIG. Let's do it. Thereafter, the bearing surface 5 is processed (as shown in FIG. 9). This is because it is possible to remove the burr caused by the above-mentioned cutting process.

Information regarding the relative position control between the workpiece 11 and the milling cutter 22 in the cutting process, that is, the shape of the bearing hole 2 (see FIG. 8 fB1 described above).
Since the coordinates of the illustrated arrow P and the bearing length 2 have already been given, and information regarding the cutting depth Δt has also been given, the desired minute cutting portion 7 can be formed. Furthermore, the manner in which the milling cutter 22 and the workpiece 11 move relative to each other during the above-mentioned cutting process is shown in FIG. 210 iB). That is, the milling cutter 22
teeth.

It moves in the direction of the arrow shown in the figure with respect to the workpiece 11.

As is clear from the embodiment shown in FIG. 2, the cutting edge of the milling cutter 22 moves so as to come into contact with the corner, so the cutting process is not performed at the corner. do not have.

In this way, the extrusion die of the embodiment shown in FIG. 15 is manufactured. In the explanation of the manufacturing method of the embodiment shown in FIG. 5, it was stated that the back relief inclined surface 6 is processed in the same manner as in the embodiment shown in FIG. Further, after the machining is carried out in accordance with the maximum value of the bearing length 2, the predetermined bearing surface 5 as shown in FIG. 3 may be formed by the above-mentioned cutting process.

Furthermore, the extrusion die of the embodiment shown in FIG. 6 can be easily manufactured by using the manufacturing methods of the embodiment shown in FIG. 4 and the embodiment shown in FIG. 5 in combination. That is, as described above, the embodiment shown in FIG. 6 is basically the same as the embodiment shown in FIG.

The bearing length 2 at the corner of the bearing hole 2 is made smaller as shown in the exploded view of FIG. The machining of the bearing surface 5 at such corner portions is carried out in the process of machining the back relief portion 3 in the embodiment shown in FIG.
is given, it is possible to form a corner bearing surface 5 having a desired bearing length a by controlling the position and inclination angle θ of the wire electrode 12 described above. In this way, the extrusion die of the embodiment shown in FIG. 6 is manufactured.

In the above description of the manufacturing method, it has been described that the bearing surface 5 is machined by a wire-cut electric discharge machining device, but it may also be carried out by the above-mentioned milling, jig grinder machining, or ordinary electric discharge machining. Moreover, the above-mentioned cutting process may also be performed by electric discharge machining suitable for the above-mentioned jig grinder process 1 in addition to milling process.

In the manufacturing method described above, while the workpiece 11 is initially placed on the processing table 8, the fourth
Any of the embodiments shown in FIGS.

Since it can be completely manufactured and, as mentioned above, can be automatically processed by NC control, the number of processing steps can be significantly reduced.

It becomes possible to manufacture extrusion dies with high precision.

In particular, since the performance of wire-cut electrical discharge machining equipment in terms of machining speed has recently improved significantly, extrusion dies are manufactured using the manufacturing method of the present invention in which most of the machining is performed by wire-cut electrical discharge machining. the time is,
This is significantly shorter than conventional manufacturing methods.

As explained above, according to one aspect of the present invention, a manufacturing device that combines a wire-cut electrical discharge machining device and a milling device is used to process a workpiece while it is initially placed on the processing table of the manufacturing device. Since it is possible to automate all machining of bearing holes and back relief parts, it is possible to significantly shorten manufacturing man-hours and reduce manufacturing costs 1. It is possible to improve mechanical strength and manufacture products with high precision. It is possible to provide a method for manufacturing an extrusion die that enables the following.

[Brief explanation of the drawing]

'') rP1 diagram (At, IBI, IcI, Figure 2 (A
Figure 3 is an explanatory diagram for explaining a conventional extrusion die, Figures 4 to i6 are explanatory diagrams for explaining an embodiment of an extrusion die manufactured by the manufacturing method of the present invention, The off-line diagram shows an example of a manufacturing apparatus used for manufacturing the extrusion die of the present invention. FIGS. 8 to 10 show explanatory diagrams for explaining the manufacturing method of the present invention. In the figure, 1 is a pouring part, 2 is a bearing hole, 3 is a back relief part, 5 is a bearing surface, 6 is a back relief inclined surface, 7 is a minute cut part, 8 is a processing table, 9°10.19.20 and 23 is a control motor, 11 is a workpiece, 11' and 1
1' is a scrap, 12 is a wire electrode, and 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 scrap p-ra, 2
1 represents a milling head, and 22 represents a milling cutter. Patent applicant: Discharge Precision Machining Research Institute Co., Ltd. Patent attorney Mori 1) Hiroshi (3 others) $ 1 Figure fB) Figure 1 Figure 82 Figure 8 Figure CA) Figure 9 (A) JP-A-114427 (10) (I3) (B) Official seal of the principal of the procedure) 1. Display of the case 1982 Patent Application No. 221678 2
, Title of the invention Method for manufacturing extrusion dies 3, Relationship to the case of the person making the amendment Patent applicant address 283 Shimohirama, Saiwai-ku, Yozaki-shi, Kanagawa Name Shoji Futamura 4, representative of the Electric Discharge Precision Machining Institute Co., Ltd., agent 5. Number of inventions increased by amendment None 6. Target of amendment Column 7, "Detailed Description of the Invention" Contents of amendment Contents of amendment as attached (1) "t, -Q, tan θ
" is corrected to "rt+=Q+cotθ". (2) "rtz-Qztanθ" on page 20, line 6 of the specification.
is corrected to "t2'=11zcotθ". that's all.

Claims (1)

[Claims] A bearing hole having a given shape is provided on the front side, a bearing surface is formed corresponding to the bearing hole from the front surface to the back surface, and a back relief portion is formed from the bearing surface toward the back surface. In the method of manufacturing an extrusion die, the bearing surface at each position on the inner peripheral line of the bearing hole is formed to have a bearing length that is substantially predetermined based on the shape of the bearing hole at that position, perpendicular to the front surface. A wire-cut electrical discharge machining device having a wire electrode running in a direction tilted at a minute angle with respect to a direction in which the back relief slope is formed has a back relief slope machining step for forming the slope surface of the back relief portion, and the back relief slope surface machining a bearing surface machining step of forming the bearing surface using a wire-cut electrical discharge machining device having a wire electrode running in a direction substantially perpendicular to the front surface after the completion of the step;
In the back relief inclined surface machining process, the wire electrode passes through a position point at a depth substantially equal to a predetermined bearing length corresponding to each position at each position on the inner peripheral line of the bearing hole. The cutting position is controlled in such a manner that, in the bearing surface processing step, the bearing surface is formed by repeating the processing in such a way that the amount of one wire electrode cut does not exceed the cutting width by the wire electrode. A method of manufacturing an extrusion die, characterized in that the cutting position of the wire electrode is controlled.