JPS59161229A - Manufacturing system of mold for tire formation by electric discharge machining - Google Patents

Abstract

PURPOSE:To enable a workpiece to be subjected to electric discharge machining in the desired direction of said workpiece by limiting the absolute driving direction of a machining electrode only to one predetermined direction, and controlling the shift and/or the rotation of a machining table in response to the electrode supply of a machining head. CONSTITUTION:Upon manufacturing a mold (lower-mold) 2 for tire formation, a processing electrode 31a mounted on a processing head 32' is firstly shifted in the electrode supplying direction (Z) of the machining head 32', while a workpiece 2' placed and fixed on the machining table (not illustrated) is shifted in the arrow (X) direction. Hereby, electric discharge machining for the workpiece 2' by the machining electrode 31a is made substantially in the arrow (a) direction. Then, electrical discharge machining in the arrow (b) direction is similarly performed by adjusting the shift amount in the arrow (X) direction of the workpiece 2' by an exchanged machining electrode 31b, and lower-mold 2 having a shape shown by (A) is formed by machining a blank part shown by a dotted line in the drawing (C).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a system for manufacturing a tire molding die by electric discharge machining, in particular, by controlling movement and/or rotation of a processing table in response to electrode feeding of a processing head.
By using an electric discharge machining device configured to enable electric discharge machining of a workpiece in a desired machining direction without tilting the machining head, automatic exchange of the machining electrode is facilitated. The present invention relates to a manufacturing system for tire molding molds that enables efficient manufacturing of tire molding molds.

The applicants of the present application have already proposed a manufacturing system for tire molding molds by electric discharge machining in Japanese Patent Application No. 54-26916. What is the proposed invention?

It has the excellent feature that it is possible to provide a tire molding die with high processing accuracy and low manufacturing cost. Furthermore, according to the above-mentioned proposed invention, it is also possible to provide a tire molding mold that is integrally constructed of one block. The invention proposed above will be briefly explained below.

Generally, when machining molds, etc. by electric discharge machining, the molds such as cutting dies, drawing dies, molds, etc., whose molding surfaces can all be viewed from one direction, have a shape that corresponds to the molding surface of the mold. Electric discharge machining may be performed by feeding a machining electrode having a machining surface in one predetermined direction. However, in a tire molding mold as shown in FIGS. 1" to 3, for example, protrusions 5 to 9 are formed which correspond to a plurality of grooves cut almost perpendicularly to the tire's tread surface. That is, the protrusions 5 to 9 protrude almost perpendicularly to the contour surface 3.
The figure is a side sectional view of one embodiment of a tire molding die, FIG. 2 is a partially enlarged sectional view of the lower die in the embodiment illustrated in FIG. 1, and FIG. 3 is a development in the direction of arrow α' shown in FIG. Shows a plan view.

In the figure, l is the upper mold, 2 is the lower mold, 3 is the contour surface and corresponds to the contact surface of the tire to be molded, 4 is the shoulder part, 5 to 9 are the protrusions, and PL is the party. Ng・
The line CL represents the joint surface between the upper mold 1 and the lower mold 2, and the center line corresponds to the center line of the south face of the tire to be molded. In this way, for example, when machining the lower mold 2 that has two or more protrusions that protrude perpendicularly to the contour surface 3 by electric discharge machining, the shape corresponding to the lower mold 2 to be machined is No matter which angular position the machining electrode (not shown) is fed in, for example, the arrow α direction or C direction shown in FIG. occurs. Therefore, in order to prevent the above-mentioned overcut, the feeding direction of the above-mentioned processing electrode is set to the protrusion 6.
The direction of the arrow α shown in FIG. The machining electrodes used for electric discharge machining in the electrode feeding directions of α゛ and b directions are as follows:
Electrical discharge machining is performed by replacing the machining electrodes with machining electrodes corresponding to the directions a and b, which are molded into a shape that can prevent overcutting as will be described later. That is, the fourth
The above α for processing the lower mold 2 shown in Figure ■
A machining electrode 10α used for machining in this direction is shown in FIG. Processing electrode l for feeding in the α direction
Oα has electrode recesses 8α and 9 to prevent overcut.
The shape corresponds to the lower mold 2 shown in FIG. 4 except that α has a shape suitable for overcut prevention as shown in FIG. Similarly, the machining electrode 10.6 for feeding in the above direction corresponds to the lower mold 2 except that the electrode recess 6b has a shape suitable for overcut prevention as shown in FIG. 40. It is formed in a shape that In order to form the lower mold 2 having the shape shown in FIG.

First, as shown in FIG. 4 (6), the processing electrode lO
The material is machined into the shape shown by the dotted line in the figure by setting α and feeding it in the direction of the arrow α shown in the figure for electrical discharge machining. Next, as shown in the fourth diagram, the processing electrode 10b
4 and the dotted line portions of the protrusions 8 and 9 that were incomplete in the machining process shown in FIG. The mold 2 shown below is obtained. In the electric discharge machining process, the electrode recesses 8α and 9a of the machining electrode 10α are formed in the machining process in the α direction, and the electrode recess 6b of the machining electrode 10b is formed in the shape shown in the figure in the machining process in the above direction. Over-cutting at the protrusion is prevented, and the desired lower mold 2 shown in FIG. 4 can be obtained. Note that the inner circumferential surface of the tire molding mold is annular.

The electrical discharge machining must be performed by dividing the inner circumferential annular surface of the tire molding die into a range corresponding to the size of the machining surface of the machining electrode in the circumferential direction. Moreover.

The shape of the inner circumferential surface of the mold formed by electric discharge machining for each of the above-mentioned divisional ranges must be continuous as shown in FIG. Therefore, the electric discharge machining apparatus (shown in FIG. 5) used in the above-mentioned proposed invention is configured so that the positioning of the machining electrode and the workpiece and the setting of the electrode feeding angle can be performed accurately. There is. In addition, in FIG. 5, the reference numeral 2' in FIG. 1 is the workpiece, 10 is the processing electrode, and 1
1 is a processing electrode mounting jig, 12 is a first processing head which feeds the processing electrode 10 in the direction of the arrow shown in the figure via the processing electrode mounting jig 11, and 12' is a control motor. 1 controls and drives the processing head 12, 13 is the second
This processing head feeds the first processing head 12 in two directions indicated by arrows in the figure.

13' is a control motor that controls and drives the second processing head 13; 14 is a spindle of the second processing head 13; 15 is a head support section; and 16 is a head rotation drive section, which is a head support section. 15 is a block that rotates in the direction of the arrow α shown in the figure, and 17 is a lift block that supports the head rotation drive unit 16 and is supported by the column 19 so that it can be raised and lowered in the direction of the arrow H in the figure by means of a lift screw. .

20 is a processing tank, 21 is a processing table, and the workpiece 2
' is placed, 22 is a table rotation drive unit that rotates (servo drive) the processing table 21 in the direction of arrow θ shown in the figure, for example by a control motor or hydraulic pressure, and 23 is a first table. The processing table 21- is moved in the direction of the arrow X in the figure together with the table rotation drive unit 22.

Reference numeral 24 represents a second table that moves the first table 23 in the direction of the arrow Y in the figure, and 25 represents a bet.

As explained above, the machining electrode used in the electrical discharge machining apparatus shown in FIG. Since electrode wear occurs, it is necessary to replace the electrode with a new one depending on the degree of wear. Therefore, in order to further reduce manufacturing costs, it is desirable to automate the electrode exchange using a labor-saving means such as an industrial robot. Needless to say, in order to perform such automatic electrode exchange smoothly, it is desirable to keep the electrode exchange position and electrode posture constant during electrode exchange. However, in the electric discharge machining apparatus shown in FIG. 5, the electrode drive direction in a broad sense is the fifth
The relative positional relationship between the machining surface and the electrode mounting surface of each machining electrode used differs in the directions of the arrows H2α, 2 and r shown in the figure, and also in accordance with the electrode feeding angle.

There is a problem that is a major obstacle to automatic electrode exchange.

The present invention aims to solve the above-mentioned problems by setting the absolute driving direction of the processing electrode to only one predetermined direction (for example, the direction perpendicular to the processing table surface),
By controlling the movement and/or rotation of the processing table in accordance with the feeding of the electrode of the processing head, the relative positional relationship between the processing electrode and the workpiece placed on the processing table can be controlled. The structure is such that it is possible to substantially perform electric discharge machining on the workpiece in the desired machining direction, and by using such an electric discharge machining device, automatic processing of the machining electrode, which leads to labor savings, is possible. It is an object of the present invention to provide a manufacturing system for tire molding molds by electrical discharge machining, which enables easy replacement and contributes to further reduction in manufacturing costs. This will be explained below with reference to the drawings.

Figures 6 (4) and (I) are front and side views showing one embodiment of the electrical discharge machining device used in the present invention, and Figures 7 (4) and 7 (O) illustrate the manufacturing process of the tire molding die of the present invention. The explanatory diagrams in Figures 8 (2) and (6) are a plan view and a side view showing an embodiment of the electrode manufacturing apparatus for manufacturing the processed electrode used in the present invention, and Figures 9 and 9 are explanatory diagrams. (
6) is an explanatory diagram for explaining the electrode manufacturing method according to the illustrated embodiment in FIG. 8, and FIG. 10 shows another embodiment of the electrode manufacturing apparatus for manufacturing the processed electrode used in the present invention. .

Prior to a detailed explanation of the system for manufacturing a tire molding die by electrical discharge machining of the present invention, FIG. 6 shows an embodiment of the electrical discharge machining apparatus used in the present invention.

(b) will be explained. Reference numeral 31 in the figure is a processing electrode.

32 is a processing head that feeds the processing electrode 31 in the direction of the arrow shown in the figure, and 32' is the tip of the head.

33 is a control motor that raises and lowers the processing head 32 in the two directions of water application arrows; 34 is a processing table;
5 to 37 are control motors, respectively, and the control motor 3
Reference numeral 5 rotates the processing table 34 in the direction of the arrow θ, a control motor 36 moves the processing table 34 in the direction of the arrow X, and a control motor 37 moves the processing table 34 in the direction of the arrow Y. It represents. Further, 3rd represents a replacement electrode, and 38' represents an electrode storage shelf in which the replacement electrode 38 is stored. Note that 2' and 20 correspond to those in FIG.

As explained at the beginning of this specification, when manufacturing a tire molding die as shown in FIGS. In order to prevent the above-mentioned overcut, machining electrodes (for example, machining electrodes 10α and l shown in FIG. 4, , ob) and perform electrical discharge machining. In this case, the processing direction for the workpiece corresponds to the feeding direction of the processing electrode. That is, in the electrical discharge machining apparatus shown in FIG.

The present invention also. Electric discharge machining is performed by changing the actual machining direction of a workpiece into a plurality of directions.

In the present invention, the feeding direction of the processing electrode is one predetermined direction (that is, the processing head is not tilted during processing), and the workpiece is moved in accordance with the feeding of the processing electrode. By doing so, electrical discharge machining can be performed in a desired machining direction. That is, a desired machining direction can be obtained by appropriately selecting a comparison between the amount of feeding of the machining electrode and the amount of movement of the machining table. below.

An embodiment of the method of manufacturing a tire molding mold according to the present invention, which is carried out using the discharge power a-machining apparatus of the embodiment illustrated in FIG. 6, will be described in conjunction with the processing example illustrated in FIG. 7.

Note that in FIG. 7, numerals 31α and 31b represent processing electrodes, and 31' represents an electrode mounting surface.

Now, it is assumed that a tire molding die (lower die) 2 having a cross-sectional shape as shown in FIG. 7 is manufactured. In the present invention, the processing direction for the workpiece 2' is not only one direction, but also at least two directions to prevent overcutting as described above.
directions (for example, the α direction and the b direction shown in FIG. 7). That is, FIG. 7(6) shows the machining state in the α direction, and FIG. 7(C) shows the machining state in the above direction. Processing electrodes 31α and 31b are used during machining in the α direction shown in FIG. 7(6) and during machining in the direction shown in FIG.

The electrodes are formed in a shape that prevents overcutting in accordance with each processing direction (electrode manufacturing used in the present invention will be described later). FIG. 7 (6) in the present invention
In the illustrated machining state, the feeding direction of the machining electrode 31α is 1
The electrode feeding direction of the processing head 32 in the illustrated embodiment of FIG. 6 is not the direction of the illustrated arrow α, that is, the illustrated arrow! The workpiece 2' is moved in the direction of the arrow X shown in FIG. 36 in the X direction), the workpiece 2'
electrical discharge machining using the machining electrode 31α.

Processing can be performed substantially in the direction of the arrow α shown in the figure. The same applies to the processing state shown in FIG. 7 (0).

The amount of movement of the workpiece 2' in the direction of the arrow X in the machining state shown in FIGS. Needless to say, it is set in advance.

As explained above, first, as shown in FIG.

By performing electric discharge machining in the direction of the arrow α shown in the figure using the machining electrode 31α, the workpiece 2' is machined into the shape shown by the dotted line in the figure. By performing electric discharge machining in the direction indicated by the arrow in the figure, the unfinished portion of the workpiece 2' indicated by the dotted line in the figure is machined, and a lower metal having the desired shape as shown in FIG. Mold 2 is formed.
In order to complete the tire molding die, the processing table 34 shown in FIG. Needless to say, the tool is rotated to process the entire circumference of the inner circumferential surface of the workpiece 2'.Also, in the description of the processing process for completing the tire molding die, For convenience of explanation, the machining state shown in FIG. 7 and the machining state shown in FIG. In order to omit the 7th
) Illustrated. Needless to say, after the machining has been carried out over the entire circumference of the inner peripheral surface, the machining shown in FIG. 7C) is carried out. Furthermore, when replacing the electrode, the processing electrode 31 is pulled up to a predetermined position and then replaced with the replacement electrode 38 on the electrode storage shelf 38' using, for example, an industrial robot (not shown). do. 1. As will be described later, the machining electrode 31 used in the present invention is formed in the same shape except for the recessed portion, and because the electrode feeding direction is only one direction, the machining electrode 31 is placed at a predetermined position. Since the electrodes are easy to position, automatic exchange of the electrodes can be easily performed.

The above two explanations have been made regarding the electrical discharge machining device used in the tire molding mold manufacturing system of the present invention and the manufacturing process of the tire molding mold using the electrical discharge machining device.Secondly, the processing electrode used in the present invention and its manufacture The device will be explained. The processing electrodes used in the present invention are 1, for example, the processing electrode 3 shown in FIG.
1α and 31b, the shapes of the electrode recesses are different depending on the processing direction (α direction and b direction in the embodiment shown in FIG. 7) in order to prevent overcut. ' has the same shape and each processing electrode 31 (Z and 31h have the same shape and each electrode mounting surface 31'
and the processed surface (including the positional relationship of the corresponding electrode recesses) are formed so that they are exactly the same. That is, it will be explained that by using the processing electrodes 31α and 31h formed in this manner, the above-mentioned automatic replacement of the processing electrodes is facilitated, and it is also possible to manufacture the tire molding mold according to the present invention. It's obvious. However, the electrode manufacturing device using the profiling method that has already been proposed by the applicants of this application (4? Application No. 54-100046) is a processing method that can prevent the above-mentioned overcut by changing the inclination angle of only the model. It manufactures electrodes.

The electrode manufacturing apparatus is not sufficient to manufacture the above-mentioned processed electrodes used in the present invention. below.

The processing electrode manufacturing apparatus used in the present invention will be explained.

Figures 8 and 8 show an embodiment of a manufacturing device using a copy processing method for processing electrodes used in the present invention, and Figure 8 is a plan view,
FIG. 8 (■) is a side view taken along the arrow A-A' shown in FIG. 8. And the code 39 in Figure 1 is an electrode model, 40
is an electrode member, 41 is a movable table, 42 is a base, 43
is a stylus.

44 is a cutter, 45 is a model mounting table, and 46 is a support shaft.

The 4th frame represents the table reference part 1. The embodiment shown in FIG. 8 is generally called a signo (-) device.

In FIG. 8, an electrode model 39 molded in a shape corresponding to a tire molding mold, that is, in the same shape as the tire to be molded by the mold, is placed on a model mounting table 45 on a movable table 41. The electrode member 40 is also placed on the movable table 41 on the model mounting base 45.
It is placed on an electrode mounting stand (not shown) that is installed similarly to the above. The movable table 41 has a support shaft 4.
6 as a fulcrum and is configured to be rotatable in the direction of arrow C shown in FIG. 8 (6). In addition, a stylus 43 and a cutter 44
is configured to be interlocked with each other in the front-rear, left-right, and up-down directions by a copying device (not shown).

Electrode manufacturing using the electrode manufacturing apparatus shown in FIG. 8 will be explained with reference to FIGS. For example, as shown in Fig. 7 (6
) When manufacturing the illustrated processed electrode 31α.

As shown in FIG. 9(4), the machining direction (arrow 4, direction) is horizontal (i.e., α direction and stylus 43).
Block gauge 48 so that the party direction matches)
is inserted between the base 42 and the table base ring portion 47 to lift the movable table 41. Then, the stylus 43 is made to trace the surface of the electrode model 39. As a result, the cutter 44 interlocking with the upper stylus 43 forms the machining electrode 31α shown in FIG. 7(b). Incidentally, parts that cannot be copied with the straight stylus 43 may be copied by replacing them with a curved stylus 43'. Also, for example, Fig. 7 (O
The illustrated processing electrode s1b can also be formed in the same manner. That is, as shown in FIG. 9 (■), the seventh
The electrode shown in the figure Ω may be processed in the same manner. In addition, Fig. 9 (
The block gauge 48' in 6) is the electrode model 3.
9 in the direction indicated by the arrow in the figure.

In FIG. 9, (2) above, an embodiment is shown in which block gauges 48 and 48' are used as means for tilting the movable table 41.

An angle indexing device or an NC device (not shown) may be used.

As explained above, the electrode manufacturing apparatus shown in FIG.

As shown in FIG. Electrodes can be manufactured easily.

Furthermore, another embodiment of the electrode manufacturing apparatus will be described with reference to FIG. The embodiment shown in FIG. 1O is an electrode manufacturing apparatus using NC control. In the figure, reference numeral 51 is an electrode member, 52 is a rotary table, and 53 to 55 are control motors.
A control motor 54 moves the rotary table 52 in the X direction shown in the figure, and a control motor 55 moves the rotary table 52 in the Y direction shown in the figure. Reference numeral 56 denotes a slide table which is placed on the rotary table 52 and moves in the direction indicated by the arrow in the figure (centripetal direction with respect to the center of rotation of the rotary table 52).

56' is a handle for driving the slide table, which drives the slide table 56 in the direction of the arrow shown in the figure; 57 is an electrode mounting table; 58 is a milling head; and 58' is a motor for rotating the cutter. Cutter 44
59 is a control motor that controls the tilting of the milling head 58 in the direction of arrow θ2 shown in the figure.

Reference numeral 60 represents a milling head supporter, and 60' represents a control motor that moves the milling head supporter 6° up and down in the direction of arrow Z in the figure.

FIG. 10 shows an electrode manufacturing apparatus according to the illustrated embodiment.

The rotation of the rotary table 52 in the θ direction and the movement in the X and Y directions are freely controlled by control motors 53 to 55.

Therefore, the slide table 5 is attached to the rotary table 52.
6. It is also possible to control the rotation of the electrode member 51 set via the electrode mounting table 57 about the rotation axis of the rotary table 52 and the movement in the X direction and the Y direction. Further, the cutter 44 of the milling head 58 that performs the molding process of the electrode member 51 is rotated by a cutter rotation motor 58', and is tilted in the direction of arrow θ2 by a control motor 59, and by a control motor 60'. It is configured so that it can be controlled up and down in two directions of arrows. Therefore, the control motor 53 to 55°59.60
By controlling ', the electrode member 51 can be processed into a desired shape. Then, as shown in FIG. 10, a plurality of electrode members 51 are set on the rotary table 52, and a desired electrode shape (for example, Fig. 7 (b)) is formed.

It is also possible to automate the electrode manufacturing process by automatically controlling the operation of each of the control motors using the NC control means based on a program set corresponding to the processing electrodes 31α, 31b) shown in the figure. Therefore, the processing electrode used in the present invention can be efficiently manufactured. Further, in the embodiment shown in FIG. 10, there is provided a slide table 56 which can be slid in two directions indicated by the arrows.

It is also possible to easily reprocess a worn-out processing electrode.

As explained above, according to the present invention, electric discharge machining can be performed in a desired direction without tilting the machining head, thereby simplifying the structure of the electric discharge machining apparatus used in the present invention, and Electrical discharge machining allows for lower manufacturing costs by facilitating automatic replacement of the machining electrode, which saves labor, because the orientation of the machining electrode is always maintained constant because the electrode feeding direction does not change. According to the present invention, a manufacturing system for a tire molding mold can be provided. In addition, automatic electrode replacement is easy, and the fact that there is no need to change the posture of the processing electrode can save labor when replacing the electrodes manually.

[Brief explanation of drawings]

Fig. 1 is a side sectional view of an embodiment of a tire molding mold, Fig. 2 is a partially enlarged view of the lower mold in the embodiment shown in Fig. 1, and Fig. 3 is a development at arrow Aa/ shown in Fig. 2. Plan view, Figure 4 or O is an explanatory diagram for explaining the basic principle of manufacturing a tire molding die by electric discharge machining,
Figures 5 (■) and (B) are front and side views of a conventional example of an electric discharge machining apparatus used for manufacturing tire molding molds, and Figures 6 (2) and (B) are one of the electric discharge machining apparatus used in the present invention. Front view and side view showing the embodiment, FIG.
) to 0 are explanatory diagrams for explaining the manufacturing process of the tire molding die of the present invention, and FIG. A plan view and a side view showing the. 9(4) and Φ) are explanatory diagrams for explaining the entire electrode manufacturing method according to the illustrated embodiment in FIG. 8, and FIG. An example is shown below. In the figure, 2' is the workpiece, 31, 31α and 31.6 are the processing electrodes, 31' is the electrode mounting surface, 32 is the processing head, 3
2' is the tip of the head, 33, 35 to 37 degrees, 53 to 55, 59 and 60' are control motors. 34 is a processing table, 38 is a replacement electrode, 38' is an electrode storage shelf, 39 is an electrode model, 40 and 51 are electrode members, 41 is a movable table, and 42 is a base. 43 and 43' are styluses, and 44 is a cutter. 45 is a model mounting table, 46 is a support shaft, 47 is a table reference part, and 48 and 48' are block gauges. 52 is a rotating table, and 56 is a sliding salary table. Reference numeral 56' represents a slide-table driving knob, numeral 5 represents an electrode mounting base, 58 represents a milling head, 58' represents a cutter rotation motor, and 60 represents a milling head support portion. Patent applicant Brideston Tire Co., Ltd. (1 other person) Representative patent attorney Mori 1) Hiroshi (3 others)

Claims (1)

[Claims] Tire molding by electrical discharge machining, in which a tire molding mold is integrally provided with a contour surface consisting of a curved surface corresponding to the tread surface of the tire to be molded, and a plurality of protrusions protruding on the contour surface, using an electrical discharge machining device. A mold manufacturing system for use in molds includes a processing head for feeding a processing electrode and a processing table for placing a workpiece, and the processing table is moved and/or rotated in response to the feeding of the electrode by the processing head. using an electrical discharge machining device configured to enable electrical discharge machining of the workpiece in a desired machining direction under a state in which the electrode feeding direction of the machining head is determined in one direction by controlling the , a machining electrode having a shape corresponding to the shape of the tire to be molded and a predetermined shape corresponding to each of the machining directions so as to prevent overcutting of the protrusion; A manufacturing system for a tire molding die by electric discharge machining, characterized in that the mold is replaced in accordance with the machining direction to perform electric discharge machining.