JP2003136337A - Machining method of metal mold for molding and electrode for electric discharge machining - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machining method of a metal mold for molding to shorten electric discharge machining time by maintaining a stable machining state even without jumping and flashing of an electrode with less residue of machining debris and gas at the time of electric discharge machining and the electrode for electric discharge machining favorable for this machining method. SOLUTION: A shape 12 of the metal mold for molding is electric-discharge- machined by using the electrode 10 for electric discharge machining an electric discharge part of which is formed of a mesh type electrically-conductive sheet, and a molded surface 13 is formed. As machining debris and gas can be efficiently discharged from meshes of the electric discharge part at the time of electric discharge machining, short circuit and abnormal electric discharge caused by it can be eliminated, and it is possible to carry out electric discharge machining in the stable machining state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for processing a molding die used for injection molding and press molding of synthetic resin and an electrode for electric discharge machining used for this processing. More specifically, the electrode is used. The present invention relates to a machining method of a molding die for machining the molding surface of the die by electric discharge machining, and an electrode for electric discharge machining.

[0002]

2. Description of the Related Art In recent years, a high-performance power source has been developed as a method for processing a molding die such as injection molding and press molding.
Since the numerically controlled electric discharge machine is also actively used, there has been proposed a method of processing a molding die by electric discharge machining using a discharge electrode instead of machining such as milling.

In the electric discharge machining using an electric discharge electrode, a transfer machining method in which an electrode having a predetermined shape is opposed to a mold material and an electrode shape is formed on the mold material depending on the machining mode, and a rod-shaped electrode is three-dimensionally directed to the mold material It is a kind of shape generation processing method and shape generation processing method that forms a molding surface of a shape different from the electrode shape on the mold material by controlling relative movement to the wire, and a wire frame that controls the movement of the wire electrode in a predetermined direction to form the formation surface. It is classified into processing methods.

It is necessary to previously form an electrode having a shape complementary to the molding surface to be formed by electric discharge machining as an electrode used in the transfer machining method.
Furthermore, the electroformed electrode method, the cutting electrode method, and the like shown in FIGS. 5 and 6 are known.

The electroformed electrode method is a master model 1 for molded products.
By casting 01 with gypsum (FIG. 5 (a)), an inverted model 102 is created by inverting the master model 101 (FIG. 5 (b)), and then the inverted model 102 is immersed in an electrolytic solution. Master model 10 by performing electroforming
1. An electroformed electrode 103 having the same shape as the outer shape of No. 1 is formed on the surface thereof ((c) in the figure).
3 is removed and used as an electrode of a transfer processing method, in which the molding surface of the mold material 104 is processed by this electroformed electrode 103 (FIG. 3D).

Further, the cutting electrode method is based on the master model 10
By measuring the shape of No. 1 three-dimensionally (Fig. 6
(A)), CAD / CAM data is obtained ((b) in the same figure), and an electrode 106 having the same shape as the outer shape of the master model 101 is processed by a milling cutter 105 for NC control based on the CAD / CAM data (same as in FIG. (C)) is a method for obtaining an electrode by a transfer machining method, in which electric discharge machining is performed on the mold material 104 by using the cut electrode 106 (FIG. (D)).

Further, the shape generation processing method as an electric discharge machining method is a method of processing the molding surface with a simple rod-shaped electrode which does not depend on the shape of the molding surface. Application to surface machining has been proposed by "Study on shape generating machining by multi-axis NC electric discharge machine (1st report)" (precision machine 49, 10 (1983) p. 32).

The shape generating method disclosed here is
Using a NC electric discharge machine capable of multi-axis control, a rod-shaped solid electrode is moved relative to a mold material serving as a molding die, and a voltage is applied between them to generate electric discharge. The adjacent portion of the mold material is melted or further evaporated by the energy, and the processed surface is formed along the movement locus.

[0009]

However, in the transfer machining method in which the electric discharge machining is performed with the electrodes formed by the electroforming electrode method or the cutting electrode method, the electrodes 103 and 106 having the same shape as the outer shape of the molded product are formed. In addition, as described above, it takes time and labor, and since the number of steps is large, it takes time and causes an increase in manufacturing cost of the mold.

Particularly, in the step of forming the electrode 106 by the cutting electrode method, the NC controller for controlling the milling cutter 105 is connected to the CA controller.
D / CAM data is input, and in the shape generation processing method, the control data is input to the NC controller that controls the movement of the electrodes for teaching, which requires a lot of labor and time. There is.

Further, in any of the conventional electric discharge machining methods, since the machining gap between the electrode and the mold material is narrow during the electric discharge machining, the machining chips and gas generated during the electric discharge machining are sufficiently discharged. I can't. For this reason, machining waste and gas remain at the machining site, short circuit and abnormal electrical discharge occur, sufficient machining depth cannot be obtained, and the electrode wears out quickly. There was also.

Therefore, during the electric discharge machining, it is necessary to perform a jump machining for temporarily retracting the electrode from the mold material, or a flushing for supplying a machining liquid to a machining site to forcibly discharge machining chips and gas. Not only the processing time becomes long, but also the processing steps become complicated.

The present invention has been made in consideration of the above conventional problems, and processing of a molding die capable of easily forming a molding surface having a shape complementary to a molded product by electric discharge machining. The purpose is to provide a method.

Further, there is little residual processing dust and gas, there is no need for jumping or flushing, and a molding die can be processed in a quick and simple process, and this machining method. It is an object of the present invention to provide an electrode for electric discharge machining suitable for.

[0015]

According to a first aspect of the present invention, there is provided a method of processing a molding die, wherein an electric discharge machining electrode having a discharge portion formed by bending a mesh-shaped conductive sheet into a tubular shape is used as a molding die. It is possible to form a molding surface along the relative movement locus of the discharge part on the mold material of the molding die while facing the mold material and controlling the relative movement of the discharge part with respect to the mold material while performing the electric discharge machining on the facing surface of the mold material. Characterize.

By using the mesh-shaped conductive sheet as the discharge part of the electric discharge machining electrode and performing discharge with the mold material, the part of the mold material corresponding to the discharge part is melted and vaporized. Therefore, even if the discharge part has a simple shape, it is possible to form a complicated molding surface along the locus of relative movement by moving the electrode relative to the mold material.

Since the electric discharge portion of the electric discharge machining electrode is formed of a mesh-shaped conductive sheet, machining waste and gas generated by electric discharge machining can be efficiently discharged from the mesh. For this reason, short-circuiting or abnormal discharge due to residual machining waste or gas does not occur, and electrical discharge machining can be continuously performed without the need for jumping or flushing. Therefore, the electric discharge machining time is shortened,
The molding die can be processed in a stable processing state.

According to a second aspect of the present invention, there is provided an electric discharge machining electrode in which relative movement is controlled while electric discharge machining is performed on a mold material of a molding die to form a molding surface on the mold material along a relative movement locus. It is characterized in that the electric discharge portion for performing electric discharge machining on the mold material is formed by bending a mesh-shaped conductive sheet into a tubular shape.

The electric discharge portion of the electric discharge machining electrode, which is in the form of a mesh, collects machining dust and gas generated by electric discharge machining.
Since it can be efficiently discharged from the mesh of the electrodes, a short circuit or abnormal discharge does not occur, and it is not necessary to perform jumping or flushing during electric discharge machining, so that electric discharge machining can be continued. Therefore, the electric discharge machining time is shortened, and the molding die can be machined in a stable machining state.

According to a third aspect of the present invention, there is provided a method of processing a molding die, wherein a mesh-shaped conductive sheet is covered along the outer shape of a master model of a molded product, and the outer shape of the master model is transferred to a bent shape. A second step of supporting a mesh-shaped conductive sheet in a state in which the transferred shape is maintained to form an electrode for electric discharge machining, and using an electric discharge electrode, transfer processing is performed on a mold material of a molding die. A third step of performing electric discharge machining and performing electric discharge machining while swinging the electric discharge machining electrode along the machining surface of the mold material formed by transfer machining, and forming a shape complementary to the molded product on the mold material of the molding die And a fourth step of forming a molding surface.

The mesh-shaped conductive sheet is flexible, can be bent along the outer shape of the master model, and maintains the bent shape. Therefore, the outer shape of the master model is transferred in the first step. it can.

The electric discharge machining electrode obtained in the second step is an electrode having the same shape as the outer shape of the molded product, to which the shape of the master model has been transferred. In the third step, this electric discharge machining electrode is used to form a mold material. By performing the transfer processing on, a processed surface having a shape substantially complementary to the outer shape of the molded product is formed. Since a mesh of the electric discharge machining electrode having a mesh-shaped electric discharge portion is left on this machining surface, in the fourth step, by performing electric discharge machining while swinging the electric discharge machining electrode along the machining surface. ,
The mesh of the processed surface is removed, and a smooth molding surface having a shape complementary to the molded product is formed on the mold material.

By this step, it is not necessary to create an electrode having the same shape as the outer shape of the molded product as in the electroformed electrode method and the cutting electrode method, and the electrode is three-dimensionally formed as in the shape generating method. There is no need to move it, and there is no need to input three-dimensional data to the NC controller for that purpose.

Further, since the electric discharge machining electrode formed of the mesh-shaped conductive sheet can efficiently discharge the machining dust and gas generated during the electric discharge machining from the mesh, It is possible to perform electric discharge machining on a die material in a short time and in a stable machining state without causing a short circuit or abnormal discharge due to the residue, and without requiring jumping or flushing.

The method of working a molding die according to a fourth aspect is characterized in that the mold material of the molding die is a zinc alloy.

Zinc alloy has a lower work function when used as a cathode material for electric discharge machining than other steel materials and aluminum alloys used as a material for a die, and can form a wider machining gap. Since the machining gap is widened in this way, it is less likely to be affected by heat due to the discharge energy. Therefore, the mesh-shaped electrode has a smaller amount of wear and can maintain a uniform distance from the surface of the mold material, and thus the molding surface can be kept uniform. It can be processed with higher accuracy.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION FIG. 1 shows a mold material 5 which is a molding die.
It is a schematic diagram showing each process of the processing method concerning one embodiment of the present invention which processes. In this embodiment, the discharge unit 1
The electric discharge machining electrode 1 in which A has a mesh shape is prepared, and the mold material 5 of the molding die is machined by electric discharge machining by the transfer machining method using the prepared electric discharge machining electrode 1.

FIGS. 1A and 1B show a master model 3
The process for producing the mesh-shaped conductive sheet 2 in which the above shape is transferred is shown. First, as shown in FIG.
A mesh-shaped conductive sheet 2 and a master model 3 created to resemble the shape of a molded product are prepared. And FIG.
As shown in (b), the conductive sheet 2 is bent along the outer shape of the master model 3 to cover it, and the shape of the master model 3 is transferred to form a three-dimensional shape.

The mesh-shaped conductive sheet 2 is made of copper, silver,
This is a mesh-like sheet in which aluminum or other wire used for general electric discharge machining is plain woven, or a sheet made of these materials is punched to form a mesh-like sheet.

In order to transfer the accurate shape of the master model 3, the sheet 2 is preferably made of a material having a small deformation resistance and a high malleability and ductility. So, for example,
When using plain weave sheet 2, master model 3
With a wire having a diameter having the flexibility necessary to transfer the shape of, the porosity, that is, a mesh with a small opening size, so that there is no unmachined part during electrical discharge machining, In the present embodiment, the sheet 2 having a wire diameter of 0.18 mm and a porosity of 33% (60 mesh) is used.

The wire diameter determines the upper limit of the maximum discharge current allowed during electric discharge machining, and the larger the electric discharge current, the faster the electric discharge machining speed. Therefore, in order to shorten the machining time, the conductive sheet 2 is used. It is desirable to increase the diameter of the wire rod that constitutes the. However, on the other hand, in order to obtain the flexibility required to transfer the shape of the master model 3 finely, a small wire diameter is required, and In order to prevent the portion from existing, a wire rod having a small porosity and a small porosity is required.

From these facts, the wire diameter and porosity of the wire material when the conductive sheet 2 is obtained by plain weaving are appropriately selected depending on the shape of the master model 3, the allowable processing time, and the like. As 0.11 to 0.21
The sheet 2 is formed in the range of mm and the porosity of 31.4 to 45.1%.

As shown in FIG. 1C, the conductive sheet 2 having the transferred shape of the master model 3 is attached to the supporting member 4 made of a wire, so that the transferred shape is maintained, and the electric discharge for electric discharge machining is maintained. It becomes the processing electrode 1. Therefore, the electric discharge machining electrode 1 formed from the mesh-shaped conductive sheet 2 also has a plurality of meshes.

As shown in FIG. 1C, for example, the support member 4 has a support ring 4a fixedly attached to the periphery of the conductive sheet 2 which is a non-transfer portion, and a support ring 4a which is connected to and suspended from the support ring 4a. The book includes a connecting wire 4b and a rod member 4c that bundles the connecting wires 4b.

In the electric discharge machining, the electric discharge machining electrode 1
Is attached to the anode side of the electric discharge machine while the supporting member 4 is attached to the cathode side of the electric discharge machine.
(See (d)) is attached and is arranged to face the electric discharge machining electrode 1.

As the mold material 5, a zinc alloy is used.
As the zinc alloy, Al: 2 to 20% by weight, Cu: 1 to
It is possible to use an alloy in which 20% by weight, Mg: 0.02 to 10% by weight, and some effective additive components are added, and the balance is Zn. As this alloy, for example, ZAS, ZA
PREC (trade name of Mitsui Mining & Smelting Co., Ltd.),
Other zinc alloys can be selected.

While the mold material 5 and the electric discharge machining electrode 1 are opposed to each other, a positive voltage is applied to the electric discharge machining electrode 1 and a negative voltage is applied to the mold material 5 so as to perform discharge between them. The electric discharge machining electrode 1 is brought closer to the mold material 5. The surface of the mold material 5 is melted by the discharge energy, and this melting is performed along the shape of the tip discharge part 1A of the electric discharge machining electrode 1. Discharge part 1A of electrode 1 for electric discharge machining
Since the outer shape of the master model 3 is transferred, the shape 5 has a concave processed surface 6A formed on the surface of the mold material 5 so as to be substantially complementary to the outer shape of the master model 3.

In the electric discharge machining, since the electric discharge machining electrode 1 in which the electric discharge portion 1A has a mesh shape is used, a mesh-shaped uneven pattern is transferred to the machined surface 6A of the mold material 5. Therefore,
When the electric discharge machining by the transfer machining reaches a predetermined machining depth, the electrode swinging mechanism (not shown) of the electric discharge machine is operated to move the electric discharge machining electrode 1 along the machining surface (see FIG. In d), electric discharge machining is performed while rocking in the front-rear and left-right directions to form the machined surface 6A as a smooth molding surface 6 that complements the outer shape of the master model 3.

As a result of experiments and examinations by the inventors of the present invention on the relationship between the pitch of the mesh of the electric discharge machining electrode 1 and the required swing width, when the pitch of the mesh is P, the swing width is about P / 2. It has been found that a smooth processed surface can be obtained by

From the above, in the middle / finishing process from the processing surface 6A to the forming surface 6, by appropriately setting the mesh pitch and the swing width of the electrode 1 to be used, the forming surface 6
Can be smoothed and the processing time can be shortened. In addition,
The swing width is appropriately set depending on the discharge energy that acts during the electric discharge machining, that is, the discharge voltage, the material such as the hardness of the die member 5, and the like.

In such an embodiment, by covering the mesh-shaped conductive sheet 2 on the master model 3,
Electrode machining electrode 1 onto which the shape of the master model 3 has been transferred
Can be created. Therefore, unlike the electroforming electrode method and the cutting electrode method, it is not necessary to create the electrode 1 having the same shape as the outer shape of the molded product, and the electrode 1 is not required to be formed during the electric discharge machining as in the shape generating method. It is not necessary to move it three-dimensionally, teaching for NC control is unnecessary based on the data therefor, and the electrode 1 can be easily created.

Further, since the electric discharge machining electrode 1 in which the electric discharge portion 1A has a mesh shape is used for electric discharge machining, machining scraps and gas generated by electric discharge machining can be efficiently discharged from the mesh.

FIG. 2 shows the electric discharge machining speed by the conventional electric discharge machining electrode in which the electric discharge portion is not mesh-shaped and the electric discharge machining by the electric discharge machining electrode 1 according to the present embodiment in which the electric discharge portion 1A is mesh-shaped. The speed is compared and shown under the same processing conditions.

In the figure, A indicates the machining speed by the conventional electrode in which the electric discharge part is solid and does not have a mesh shape. At the beginning of electric discharge machining, although the machining proceeds stably, the machining depth is about 2 mm. When it reaches, the processing state becomes unstable and the subsequent processing does not proceed. It is presumed that this is largely due to the fact that when the processing progresses to a certain extent, it becomes difficult to discharge the processing chips and the gas, and a short circuit or abnormal discharge occurs due to these residues.

In order to solve this problem, B in the figure shows a jump operation in which the electric discharge part is periodically withdrawn from the machining surface to discharge machining dust and machining gas in the electric discharge machining using the same electrode. It shows the machining speed of electrical discharge machining. Although the machining progresses with stable electrical discharge machining, the target machining depth z of 7 mm due to the periodical jump motion.
Processing time t of about 130 minutes is required to obtain

On the other hand, according to the electrode 1 in which the discharge part 1A has a mesh shape, as shown by C in the figure, the machining depth z proportional to the machining time t can be obtained by stable machining, and the machining depth z is about 10.
The target processing depth has reached 7 mm in 0 minutes.

That is, as in the present embodiment, by forming the discharge portion of the electric discharge machining electrode in a mesh shape, machining waste and gas are smoothly discharged through the mesh regardless of the machining depth. A constant processing speed can be obtained while maintaining a stable processing state.

Therefore, not only jumping and flushing are not required, but also the consumption of the electrodes can be prevented, whereby the electric discharge machining time is shortened and the molding surface with a high machining accuracy is used as a molding die material. 5 can be formed.

Furthermore, a zinc alloy is used as the material of the mold member 5. When zinc alloy is used as a cathode material for electric discharge machining, the work function of steel is about 4.5 eV, whereas zinc alloy is as low as about 3.4 eV and is a material suitable for electric discharge machining. .

The work function is related to the machining gap formed by electric discharge machining. The lower the work function of the cathode material, the wider the machining gap under electric discharge machining under the same conditions. As a result, it is possible to form a wide working gap as compared with steel materials. This is because the zinc alloy has a melting point of 400 ± 30 ° C. and a boiling point of about 900 ° C., and since the melting point and boiling point are lower than those of steel materials, the depth from the metal surface that melts with one discharge energy is deep, and This is because the evaporation phenomenon also becomes active and the molten metal easily scatters.

As described above, since a wide machining gap is formed by using the zinc alloy as the die material 5, the electric discharge machining electrode 1 is less likely to be thermally affected by the electric discharge energy, and the electric discharge machining electrode 1 is consumed. Is less. Accordingly, the distance between the electric discharge machining electrode 1 and the machined surface 6A of the die material 5 can be kept constant, and the machined surface 6A can be machined with high accuracy.

FIG. 3 and FIG. 4 show another embodiment of the present invention in which an electric discharge machining electrode having a mesh-shaped electric discharge portion is used as an electrode for the shape generating machining method.

In the embodiment shown in FIG. 3, the mesh-shaped conductive sheet is formed in a vertically long rectangular tube shape so as to cover the bottom surface and the side surface of the square pole, and the discharge portion 1 of the electric discharge machining electrode 10 is formed.
It is set to 0A.

The entire electric discharge machining electrode 10 is suspended and supported by fixing the upper end of a square tubular conductive sheet to the electrode holder 11. The electrode holder 11 is supported on the anode side of an NC electric discharge machine (not shown) capable of multi-axis control, so that movement in three dimensions and rotation around the axis are controlled.

Then, as shown in the figure, the electric discharge machining electrode 10 (the electric discharge portion 10A) is made to be + in a state in which a mold material 12 serving as a molding die is opposed below the electric discharge portion 10A in the shape of a square cylinder.
While applying the voltage of the pole and the voltage of the negative electrode to the mold material 12 to perform the electric discharge machining on the surface of the mold material 12 which is the facing surface of the discharge part 10A, the discharge part 10A is controlled by NC, for example,
It is moved relative to 2 along the locus indicated by the arrow.

By performing discharge between the discharge part 10A and the mold material 12, a portion corresponding to the electrode 10 is melted.
By relatively moving the discharge unit 10A in this state,
A desired molding surface 13 along the relative movement locus can be processed into the mold material 12. Here, a zinc alloy is used as the mold material 12.

Also in this embodiment, since the electric discharge part 10A of the electric discharge machining electrode 10 for electric discharge machining is formed of a mesh-shaped conductive sheet, the machining waste and gas generated by the electric discharge machining are meshed. Can be efficiently discharged. For this reason, short-circuiting or abnormal discharge due to residual machining waste or gas does not occur, and electric discharge machining can be continuously continued without the need for jumping or flushing. Therefore, the molding die can be processed in a short time and in a simple process.

In the electric discharge machining by the shape generating machining method, since the electric discharge portion 10A is controlled to move along the machining surface, a mesh formed by the mesh-shaped electric discharge portion 10A is formed on the machining surface like the transfer machining method. Never formed
Therefore, the step of rocking the electric discharge machining electrode 1 as in the first embodiment is not always necessary.

The shape of the electric discharge portion of the electric discharge machining electrode formed of the mesh-shaped conductive sheet is a simple shape,
Various three-dimensional shapes can be formed according to the molding surface of the mold material to be processed.

FIG. 4 shows a case where the curved forming surface 23 is machined, and the electric discharge part 20A of the electric discharge machining electrode 20 supported by the electrode holder 21 has a vertically elongated cylindrical shape so as to cover the bottom surface and the side surface of the cylinder. Has been formed. Then, the electric discharge part 20A is relatively moved along the arcuate locus shown by the arrow while discharging with the mold material 22, so that the daruma-shaped forming surface 23 can be processed.

The present invention is not limited to the above embodiment, but can be variously modified. For example, a metal material other than a zinc alloy may be used as the mold material, and the molding die to be processed may be one used for press working.

[0062]

According to the first and second aspects of the present invention, since the electric discharge machining electrode in which the electric discharge portion has a mesh shape is used during electric discharge machining, the generated machining scraps and gas are discharged from the mesh mesh. It can be discharged efficiently. Therefore, a short circuit or abnormal discharge due to residual machining waste or gas does not occur, and stable electrical discharge machining can be continued without the need for jumping or flushing,
Electric discharge machining time can be shortened.

According to the third aspect of the present invention, by covering the master model, it is possible to obtain the electric discharge machining electrode having a shape in which the outer shape of the master model is transferred, and the electric discharge machining electrode used in the transfer machining method is easily prepared. can do.

Further, since the electric discharge machining electrode has a mesh shape, machining scraps and gas generated during electric discharge machining are efficiently discharged from the mesh, resulting in a short circuit and abnormal electric discharge. The stable processing condition can be maintained and the molding surface can be processed.

Further, since jumping or flushing for discharging machining waste is not required, the electric discharge machining time can be shortened and the molding surface of the molding die can be machined in a simple process.

According to the invention of claim 4, in addition to the effect of the invention of claim 1 or 3, since a wide machining gap can be formed, the amount of consumption of the electric discharge machining electrode is reduced and the surface of the die material is reduced. The distance between and can be kept uniform, and the molding surface can be processed with high precision.

[Brief description of drawings]

1A and 1B show steps of a processing method according to an embodiment of the present invention for processing a mold material 5 serving as a molding die, wherein FIG. 1A shows a mesh-shaped conductive sheet 2 used for electric discharge machining and a molded product. Of the master model 3 is prepared, (b) is a step of transferring the shape of the master model 3 with the mesh-shaped conductive sheet 2, and (c) is a step of supporting the conductive sheet 2 and discharging. FIG. 2D is a schematic view showing a step of forming a machining electrode 1 and a step of performing an electric discharge machining of a mold material 5 serving as a molding die by the electric discharge machining electrode 1.

FIG. 2 is a comparative diagram showing a comparison between a conventional electric discharge machining electrode having a non-meshed electric discharge portion and an electric discharge machining speed by the electric discharge machining electrode 1 having a meshed electric discharge portion 1A.

FIG. 3 is a perspective view showing an electric discharge machining state according to another embodiment of the present invention applied to a shape generating machining method.

FIG. 4 is a perspective view showing an electric discharge machining state according to still another embodiment applied to the shape generating machining method.

FIG. 5 shows a conventional machining method in which an electrode formed by an electroformed electrode method is used to perform electric discharge machining of a molding surface on a mold material. (A) shows a step of molding a master model 101 of a molded product with gypsum ( (b) is a step of creating an inverted model 102 by inverting the master model 101, and (c) is a step of forming an electroformed electrode 103 having the same shape as the outer shape of the master model 101 by performing electroforming. d) is an electroformed electrode 103
FIG. 6 is a schematic view showing a step of processing the molding surface of the mold material 104 by using as an electrode of the transfer processing method.

FIG. 6 shows a conventional machining method of electric discharge machining a molding surface of a mold material 104 with an electrode 106 formed by a cutting electrode method,
(A) is a step of three-dimensionally measuring the shape of the master model 101, (b) is a step of obtaining CAD / CAM data from the measured values, and (c) is an NC based on the CAD / CAM data. The step of processing the electrode 106 having the same shape as the outer shape of the master model 101 by the controlling milling cutter 105,
(D) is a schematic diagram showing a step of processing the molding surface of the mold material 104 using the cut electrode 106 as an electrode of the transfer processing method.

[Explanation of symbols]

1, 10, 20 EDM electrodes 1A, 10A, 20A discharge part 2 Mesh conductive sheet 3 master model 5, 12, 22 type materials 6, 13, 23 Molding surface

Continued front page    F term (reference) 3C059 AA01 AB01 DA00 DA08                 4F202 AJ02 CA30 CB01 CD02 CD18                       CD28 CK11

Claims (4)

[Claims] 1. An electrode (1) for electrical discharge machining, wherein the electrical discharge part (10A) is formed by bending a mesh-shaped conductive sheet into a tubular shape.
0) is made to face the die material (12) of the molding die, and the electric discharge part (1
0A) is controlled to move relative to the mold material (12), and a molding surface (13) is formed on the mold material (12) of the molding die along the relative movement trajectory of the discharge part (10A). Processing method of molding dies. 2. An electric discharge machining electrode (1) for forming a molding surface (13) on a mold material (12) along a relative movement trajectory, the relative movement of which is controlled while the mold material (12) of the molding die is electric discharge machined.
0), which is an electric discharge part (10A) for performing electric discharge machining on the mold material (12)
Is formed by bending a conductive mesh sheet into a tubular shape. 3. A first step of covering a mesh-shaped conductive sheet (2) along the outer shape of a master model (3) of a molded product and bending the outer shape of the master model (3) into a transferred shape. A second step of supporting a mesh-shaped conductive sheet (2) in a state where the transferred shape is maintained to form an electric discharge machining electrode (1), and a molding metal using the electric discharge machining electrode (1) The third step of performing electric discharge machining by transfer machining on the mold material (5) of the mold, and along the machined surface of the mold material (5) formed by transfer machining,
A fourth step of performing electric discharge machining while swinging the electric discharge machining electrode (1) to form a molding surface (6) having a shape complementary to the molded product on the mold material (5) of the molding die. And a method for processing a molding die. 4. The method of processing a molding die according to claim 1, wherein the mold material (5) of the molding die is a zinc alloy.