JPS6224213B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a machining electrode used in an electrical discharge machining device, and particularly to an electrical discharge machining device that performs electrical discharge machining by replacing a plurality of machining electrodes of one or more types. The present invention relates to a method for manufacturing a processing electrode and an apparatus therefor.

As is generally known, electric discharge machining equipment is
It is used in a wide range of machining fields, taking advantage of the excellent characteristics of electrical discharge machining. In particular, it is possible to machine the workpiece regardless of its mechanical properties, such as hardness, tensile strength, and work hardening properties, and even when machining complex shapes, it can be machined with a shape that corresponds to the shape to be machined. Electrical discharge machining equipment is widely used in the field of mold machining because high-precision machining is possible by using electrode tools.

In general, when machining molds using electric discharge machining equipment, the feeding direction of the machining electrode is Only one predetermined direction is sufficient. however,
For example, in order to manufacture a mold with multiple protrusions that protrude almost perpendicularly on a curved surface, such as a tire mold, by electrical discharge machining, the feeding direction of the machining electrode is not limited to only one direction. , it is necessary to change the position of the tire in a radial direction from the center of the tire mold, and further in a plurality of angular positions in each radial direction. That is, generally, a tire molding mold is composed of an upper mold 1 and a lower mold 2, as shown in FIG. 1 (a sectional view of one embodiment of a tire molding mold). The inner circumferential surfaces of the upper mold 1 and the lower mold 2 are coated with the inner peripheral surfaces of the upper mold 1 and the lower mold 2 as shown in FIGS.
A complexly shaped uneven surface is formed as shown in the developed plan view at A'. In the figure, 1 is an upper mold, 2 is a lower mold, 3 is a contour surface and corresponds to the ground contact surface of the tire, 4 is a shoulder part, and 5 to 9 are protrusions. 6 and 8 protrude substantially perpendicularly to the curved surface of the contour surface 3. In addition, PL is the parting line, which is the joint surface between the upper mold 1 and the lower mold 2,
CL is a center line, which is the center line of the contour surface 3, and the arrow B line shown in FIG. 3 indicates a line corresponding to the cross section shown in FIG. 2.

In order to mold the upper mold 1 or the lower mold 2 by electric discharge machining, a machining electrode having an uneven shape opposite to that of the upper mold 1 or the lower mold 2 is used. However, in general, a plurality of substantially perpendicular grooves are often formed on the ground contact surface of a tire. That is, for example, as shown in FIG. 2 showing a side cross section of the lower mold 2, the contour surface 3
Protrusions 6 and 8 are formed to protrude substantially perpendicularly to the base. As in the embodiment shown in FIG. 2, when at least two protrusions are provided that protrude almost perpendicularly to the contour surface 3, the feeding direction of the processing electrode can be set at any angular position. However, if it is attempted to process the protrusions 6 and 8 at the same time, for example, overcutting in one or both of the protrusions is unavoidable. Therefore, as proposed in ``System for Manufacturing Tire Molding Molds by Electrical Discharge Machining'' (Patent Application No. 26919 of 1972), which has already been filed by the inventors of the present application, the machining electrode is first processed. The above-mentioned overcut can be prevented by feeding the material in the direction of the arrow a shown in Figure 2 to perform machining, then replacing the machining electrode and performing the machining in the direction of the arrow b shown in Figure 2. I can do it. The machining electrode for machining in the a direction and the b direction is the fourth
As shown in Figures A and B, it is necessary to use processing electrodes of different shapes.

FIGS. 4A and 4B are explanatory diagrams illustrating one embodiment of the electrical discharge machining process of a tire molding die, and the reference numerals 2, 3, and 6 to 9 in the figures refer to FIGS. 1 to 3. 10a and 10b are processing electrodes, 6a to 9a are electrode recesses formed on the processing surface of the processing electrode 10a, and 6b to 9b are electrode recesses formed on the processing surface of the processing electrode 10b. Reference numeral 11 denotes a machining electrode mounting jig, which is fixed to a machining head (not shown), and is used to feed the machining electrode by the machining head.

For example, in order to process the lower mold 2 of the tire molding die as shown in FIG. 4B by electric discharge machining, first, as shown in FIG. 4A, the machining electrode The mold 10a is fed in the direction of the arrow a and processed into the shape of the lower mold 2 as shown in FIG. 4A. Then, as illustrated in FIG. 4B,
The desired figure B in FIG.
The lower mold 2 as shown in the figure is formed (the above-mentioned processing order may be performed in the order of the b-direction and the a-direction). Comparing the shape of the electrical discharge machining surface of the machining electrodes 10a, 10b with the shape (not shown) corresponding to the shape of the desired tire molding mold, that is, the lower mold 2 shown in FIG. 4B. The only difference is the electrode recesses 8a and 9a in the processing electrode 10a, or the electrode recess 6b in the processing electrode 10b, and the other parts may be the same. However, in the conventional electrode manufacturing means using the conventional copying method, the processing electrodes 10a and 1
Separate copying models corresponding to 0b were required. Furthermore, as stated at the beginning of this specification, when the tire molding die is machined by electric discharge machining, the feeding direction of the machining electrode is changed from the center of the tire molding die to a radial direction. The frequency of electrode replacement is very high because of the amount of work that must be done and the fact that processing electrodes inevitably suffer from electrode wear. Therefore, not only is it necessary to manufacture a large number of machining electrodes, but when manufacturing each machining electrode, strict precision regarding the relative positional relationship between the electrical discharge machining surface of the machining electrode and the mounting surface of the electrode mounting jig is required. There is no need to do so. Therefore, the conventional electrode manufacturing means requires a large number of man-hours to manufacture the electrode, and as a result of having to rely on experienced technicians, the manufacturing cost becomes high.

The present invention aims to solve the above-mentioned problems, and is intended to perform copying machining using a plurality of machining electrodes used in an electric discharge machining device that performs electric discharge machining by replacing a plurality of machining electrodes of one or more types. In manufacturing by this method, the inclination angle of the copying model can be set to a desired angle, a spherical stylus is used as necessary, and the electrode positioning part of the electrode mounting jig in the electrical discharge machining device is used. By setting the electrode workpiece on an electrode mounting table having the same shape and forming the machining electrode, multiple pieces can be formed with high accuracy in the relative positional relationship between the electrical discharge machining surface and the electrode mounting surface of each machining electrode. It is an object of the present invention to provide a method for manufacturing a machining electrode for use in an electric discharge machining device, which enables manufacturing of a machining electrode of 1,000 yen, and has a low electrode manufacturing cost, and an apparatus therefor.
This will be explained below with reference to the drawings.

FIG. 5 and FIG. 6 are explanatory diagrams for explaining one embodiment of the method for manufacturing a processed electrode in the present invention,
FIG. 7 is an overall front view showing an embodiment of the electrode manufacturing apparatus according to the present invention, FIG. 8 is a perspective view of an embodiment of an electrode workpiece mounting table, and FIG. 9A is a tilting mechanism of a copying model. 1st embodiment plan view, Fig. 9B is Fig. 9A
FIG. 2 is a cross-sectional view taken along arrow A-A' in the figure.

First, a method for manufacturing a processing electrode according to the present invention will be explained. The processed electrode manufacturing method of the present invention includes, for example, the first method described at the beginning of this specification.
Multiple types of machining electrodes with partially different shapes, such as the machining electrodes used for electrical discharge machining of tire molding molds shown in Figures 3 to 3;
That is, for example, the processing electrodes 10a and 10b shown in FIGS. 4A and 4B are formed by a copying process in which a single copying model is used and the inclination angle of the copying model is changed. It is something to be processed.

FIGS. 5 and 6, which show one embodiment of the method for manufacturing a processing electrode according to the present invention, show the processing electrodes 10a and 10 shown in FIGS. 4A and 4B above.
This shows the manufacturing method of b. Code 6a in the figure
10a to 10a correspond to FIG. 4A, 6b to 1
0b corresponds to FIG. 4B, respectively. 12 is a copying model, 13 is a cutter, 14 is a stylus,
15 is an electrode positioning fitting part, 16 is a model positioning fitting part, and 17 is an electrode mounting surface. Further, 3' is a model contour surface formed corresponding to the contour surface 3 shown in FIGS. 1 to 4, and 3a and 3b are electrode contour surfaces, respectively. 3', and 5' to 9' are model recesses, which correspond to the protrusions 5 to 9 of the tire molding die to be molded as shown in Figs. 1 to 3. θ represents the intersecting angle of extension lines of the model recesses 6' and 8' in the copying model 12. Furthermore,
PL is the parting line corresponding to the parting line PL shown in Figures 1 to 3.
It's a line.

The method for manufacturing a processed electrode according to the present invention is carried out using an electrode manufacturing apparatus using a copying method, which will be described later. The cutter 13 in FIGS. 5 and 6 rotates and moves in response to the movement of the stylus 14. Therefore, in general, by moving the stylus 14 by sliding the surface of the copying model 12 that has been formed in advance in accordance with the desired machining shape, the cutter 1 is shaped in accordance with the stylus 14.
3 also moves. Therefore, the cutter 13 processes the electrode workpiece into a shape corresponding to the copying model 12. Note that by appropriately determining the groove width of the model recesses 6' to 9' formed in the copying model 12 in advance from the relationship between the diameter of the stylus 14 and the diameter of the cutter 13, a desired shape can be obtained. A processing electrode 10a or 10b can be obtained.

The basic matters of the method for manufacturing a processed electrode according to the present invention have been explained above. Next, the manufacturing method of the present invention will be specifically explained in relation to the processing electrodes 10a and 10b shown in FIG.

First, the processing electrode 10 shown in FIG. 4A
The manufacturing method of a will be described. The machining electrode 10a is used when performing electrical discharge machining by feeding the machining electrode in the direction of arrow a shown in FIG. 4A. Therefore,
Electrode recesses 8a and 9a of the processing electrode 10a
must be shaped as shown in FIG. 4A to prevent overcutting as described at the beginning of this specification. That is, the model recess 8' of the copying model 12 shown in FIG.
The shape must correspond to the shape in which the hatched portions at and 9' have been removed. Therefore, in the present invention, the stylus 14 for sliding the copying model 12 has a spherical tip as shown in FIG. That is, the processing electrode 10a shown in FIG. 4A is manufactured by the following steps as shown in FIG.
The copying model 12 is installed so that the depth direction of the model recess 6' of the copying model 12 is perpendicular, and the tip of the copying model 12 is formed into a spherical shape. This is done by sliding the stylus 14 and using the cutter 13 which moves in response to the movement of the stylus 14. Since the processing electrode 10a is a processing electrode for processing the lower mold 2, it is sufficient to copy a portion of the copying model 12 to the left of the parting line PL in the figure. As a result, as shown in Figure 5,
The machining electrode 10a is formed with an electrode contour surface 3a and electrode recesses 6a and 7a having shapes corresponding to the model contour surface 3' and the model recesses 6' and 7' of the copying model 12, and a model recess 8'. Electrode recesses 8a and 9a are formed in shapes corresponding to the shapes of electrodes 8a and 9'.

Next, the processing electrode 10 illustrated in FIG. 4B
The manufacturing method of b will be explained. Processing electrode 10b
is used when performing electric discharge machining by feeding a machining electrode in the direction of arrow b shown in FIG. 4B.
Therefore, the depth direction of the electrode recess 8b of the processing electrode 10b must be in the b direction, that is, perpendicular to the electrode mounting surface 17. Therefore, the copying model 12 is tilted clockwise by an angle θ from the state shown in FIG. 5 to the state shown in FIG. 6, and installed so that the depth direction of the model recess 8' coincides with the vertical direction. Then, as shown in Figure 6,
Parting line of the copying model 12 above
By sliding the stylus 14 on the left side of the PL, the cutter 13 processes the object to be processed to obtain a processed electrode 10b having a desired shape. That is, since the tip of the stylus 14 is spherical, as shown in FIG.
The electrode contour surface 3b and the electrode recesses 7b, 8b, and 9b are formed in a shape corresponding to the copying machining model 12, and only the electrode recess 6b has a shape that prevents the above-mentioned overcut, that is, the shape for the copying machining. The model 12 is formed into a shape corresponding to the shape from which the hatched portion in the model recess 6' has been removed.

As mentioned at the beginning of this specification, in electrical discharge machining in which multiple machining electrodes are exchanged,
The relative positional relationship between the electrical discharge machining surface of each of the plurality of machining electrodes and the mounting surface with respect to the electrode mounting jig is important. In the present invention, as shown in FIGS. 5 and 6, an electrode mounting surface 17 and an electrode positioning fitting part 15 (details will be described later) are formed in advance on the electrode workpiece. Since the manufacturing method of the machining electrode is performed using the electrode mounting surface 17 and the electrode positioning fitting part 15 as a reference, it is possible to increase the accuracy of the relative positional relationship between the electrical discharge machining surface and the mounting surface of the machining electrode. I can do it.

Next, a processing electrode manufacturing apparatus according to the present invention for carrying out the above manufacturing method will be described.
Reference numerals 12 to 16 in FIGS. 7 to 9 for explaining the manufacturing apparatus correspond to those in FIGS.
is a milling head, 19 is a copying head, 20 is a milling head.
21 is a head moving device, 21 is a workpiece mounting table, 22 is a positioning fitting part, 23 is a model mounting table, 24 is a bracket, 25 is a tombstone, 26 is an X-axis tilting handle, 27 is a Y-axis tilting handle, 28 and 29 30 and 31 each represent a set vault, 30 and 31 each represent a cross table, and 32 to 35 each represent a table moving handle.

In FIG. 7, a milling head 18 rotates a cutter 13 to process an electrode workpiece 10.
A copying head 19, which slides the stylus 14 on the surface of the copying model 12 to copy the shape of the copying model 12, is fixed to a head moving device 20. The head moving device 20 moves in conjunction with the sliding movement of the stylus 14 on the surface of the copying model 12 as shown by the arrow X in FIG.
direction (i.e. left-right direction), Y direction (i.e. front-back direction)
and the Z direction (that is, the vertical direction). Therefore, the cutter 13 moves the stylus 14 in accordance with the sliding motion on the surface of the copying model 12, thereby shaping the electrode workpiece 10 into the shape of the copying model 12. It will be molded into a corresponding shape. Further, the electrode workpiece 10 is set on a workpiece mounting table 21. As shown in FIG. As shown in FIG. 8, which is a perspective view of one embodiment of the workpiece mounting table 21, the workpiece mounting table 21 is provided with a positioning fitting part 22. The positioning fitting part 22
1 is an electrode mounting jig 11 fixed to a machining head (not shown) in an electrical discharge machining apparatus that performs electrical discharge machining using a machining electrode manufactured according to the present invention.
It is formed in the same shape as the electrode attachment fitting part (not shown) provided in the processing electrode attachment part (shown in FIG. 4). Further, the electrode workpiece 10 is provided with a positioning fitting part 15 which is fitted into the positioning fitting part 22. When setting the electrode workpiece 10 on the workpiece mounting table 21, the positioning fitting part 15 is fitted into the positioning fitting part 22 and set. Therefore, in the machining electrode manufactured by the electrode manufacturing apparatus of the present invention, which performs forming processing based on the positioning fitting part 22, the positioning fitting part 15 always serves as the reference for the electrical discharge machining surface. Therefore, as long as the machining electrode is mounted by matching the positioning fitting part 15 to the electrode mounting fitting part (not shown) of the electrode mounting jig 11 (shown in FIG. 4), the machining electrode will not shift due to electrode replacement. do not have.

Next, model 1 for copying in the electrode manufacturing method of the present invention explained with reference to FIGS. 5 and 6.
The second tilting mechanism will be explained. That is, the copying model 12 according to the present invention is set on a model mounting table 32 as shown in FIG. 7 (more specifically as shown in FIG. 9). That is, the copying machining model 1
2 and the model mounting table 23 are provided with positioning means similar to those of the electrode workpiece 10 and the workpiece mounting table 21 described above, and the copying machining model 12 is aligned with the model using the positioning means. Mounting table 23
is set to . And the above model mounting table 2
3 is indicated by the arrow y through the Y axis as shown in FIG.
It is supported by a bracket 24 so as to be rotatable in the direction, and the bracket 24 is rotated in the direction indicated by the arrow
It is supported by the tombstone 25 so as to be rotatable in the direction. That is, the bracket 24 is tilted at a desired angle in the direction indicated by the arrow x by operating the X-axis tilting handle 26, and the model mounting table 23 is tilted at a desired angle in the direction indicated by the arrow x by operating the Y-axis tilting handle 27. It is configured to be tilted at a desired angle in the y direction. In addition, Set Vault 2
8 and 29 are provided to maintain the above-mentioned inclination angle. By operating the X-axis tilting handle 26 and the Y-axis tilting handle 27, it becomes possible to hold the copying model 12 at a desired tilt angle with respect to the two directions, the x and y directions. The electrode manufacturing method of the present invention can be implemented.

Further, the workpiece mounting table 21 is placed on a cross table 30 which is movable in the front and rear and left and right directions, and the tombstone 25 supported by the model table 23 via a bracket 24
is placed on a cross table 31 which is movable back and forth and left and right.
That is, the workpiece mounting table 21 can be moved to a desired position by operating a table moving handle 32 that moves the cross table 30 in the left-right direction or a table moving handle 33 that moves the cross table 30 in the front-back direction. The copying model 12 is configured to be movable by operating a table moving handle 34 that moves the cross table 31 in the left-right direction or a table moving handle 35 that moves the cross table 31 in the front-back direction. ing. Therefore, the electrode workpiece 10 set on the workpiece mounting table 21
The relative positional relationship between the model mounting table 23 and the model mounting table 23 can be set to a desired distance.

As explained above, according to the present invention, the plurality of machining electrodes used in an electric discharge machining device that performs electric discharge machining by replacing one or more types of machining electrodes are manufactured by a copying machining method. In doing so, the inclination angle of the copying machining model can be freely set to a desired angle, a spherical stylus is used as necessary, and a positioning part having the same shape as the electrode positioning part of the electrode mounting jig in the electrical discharge machining device is used. By setting the workpiece to be processed on an electrode mounting table having an electrode mounting table and forming the processing electrode, it is possible to process multiple pieces with high precision in the relative positional relationship between the electrical discharge machining surface and the electrode mounting surface of each processing electrode. It is possible to provide a method and apparatus for manufacturing a machining electrode used in an electric discharge machining apparatus, which enables the manufacture of electrodes and has low electrode manufacturing costs.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of a tire molding mold, FIG. 2 is a partially enlarged sectional view of the lower mold 2 in the embodiment shown in FIG. 1, and FIG.
A developed plan view at A', FIG. 4 is an explanatory diagram for explaining one embodiment of the electrical discharge machining process of a tire molding die, and FIGS. An explanatory diagram for explaining an embodiment, FIG. 7 is a front view showing an embodiment of a processing electrode manufacturing apparatus according to the present invention, and FIG. 8 is a perspective view of an embodiment of an electrode workpiece mounting table according to the present invention. , No. 9
The figure shows an explanatory diagram for explaining the tilting mechanism of the copying model in the present invention. In the figure, 3' is a model contour surface, 3a and 3b are electrode contour surfaces, 5' to 9' are model recesses, 6a to 9a and 6b to 9b are electrode recesses, respectively, 10 is an electrode workpiece, 10a and 1
0b is a processing electrode, 11 is an electrode mounting jig, 12
13 is a model for copying processing, 13 is a cutter, 14 is a stylus, 15 is an electrode positioning fitting part, 16 is a model positioning fitting part, 17 is an electrode attachment part, 18 is a milling head, 19 is a copying head, 20 is a head A moving device, 21 is a workpiece mounting table, 22 is a positioning fitting part, 23 is a model mounting table, 24 is a bracket,
25 is a tombstone, 26 is an X-axis tilt handle, 27
28 and 29 are set vaults, 30 and 31 are cross tables, respectively, and 32 to 35 are table moving handles, respectively.

Claims (1)

[Claims] 1. The apparatus is configured to perform machining with different electrode supply directions, and performs electrical discharge machining by replacing each of a plurality of types of machining electrodes in correspondence with each machining with a different supply direction. In a method for manufacturing a machining electrode for use in an electrical discharge machining device, in which the plurality of types of machining electrodes used in the electrical discharge machining device configured to perform the above-mentioned electrical discharge machining are each formed by a copying method, the surface of the model for copying machining is A profiling device is used that performs profiling using a cutter that maintains a predetermined positional relationship with respect to the stylus while sliding with a stylus. After setting the electrode workpiece, which has a positioning fitting part and a positioning fitting part formed in advance for fitting into the electrode mounting jig of the electrical discharge machining apparatus, into the positioning fitting part, each of the electrodes is The machining model is tilted and set by an angle corresponding to the supply direction, and machining electrodes corresponding to each supply direction of the electrode are manufactured while sliding the set machining model with the stylus. A method of manufacturing a machining electrode using an electrical discharge machining device, characterized in that: 2. Claims characterized in that a stylus that slides on the surface of the copying model has a spherical body at its tip, and the stylus slides on the surface of the copying model with the spherical body. 2. A method for manufacturing a machining electrode used in the electrical discharge machining apparatus according to item 1. 3. An electrical discharge machine configured to perform machining in which the supply directions of electrodes are different, and to perform electrical discharge machining by exchanging each of a plurality of types of machining electrodes in response to each machining in which the supply directions are different. A manufacturing device for a machining electrode used in an electrical discharge machining device, which molds the plurality of types of machining electrodes used in the machining device using a copying method, which corresponds to the electrode mounting jig of the electrical discharge machining device. a positioning fitting part that is formed into a shape and on which the electrode workpiece is placed;
A model mounting table on which a copying model is placed and tiltable relative to the electrode workpiece, and sliding on the surface of the copying model placed on the model mounting base and tiltable. It comprises at least a stylus and a cutter that moves so as to maintain a predetermined positional relationship with respect to the stylus, and the stylus slides on the surface of a copying model that is inclined at an angle corresponding to the electrode supply direction. An apparatus for producing a machining electrode for use in an electric discharge machining apparatus, characterized in that the cutter is configured to form an electrode workpiece using the cutter. 4. The apparatus for manufacturing a machining electrode used in an electrical discharge machining apparatus according to claim 3, wherein the stylus is a spherical stylus with a spherical body at its tip.