JP2002273626A - Manufacturing method of die for forming honeycomb structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a die for forming a honeycomb structure capable of performing efficient electric discharge machining of slit grooves in the die for forming the honeycomb structure. SOLUTION: In the manufacturing method of the die for forming the honeycomb structure having feed holes 81 and the slit grooves 82, after forming the feed holes 81 in a hole opening surface 84 of a die stock 80, a plurality of prepared holes 83 are made so that a part at the position for making the slid grooves is communicated with the feed holes 81. Electric discharge machining is performed while sucking working fluid 7 from a groove forming surface 85 side to the hole opening surface 84 side through the prepared holes 3. Then, the electric discharge machining is stopped, the slit grooves 81 are opened, and back flow is performed in which the working fluid 7 is ejected from the hole opening surface 84 side to the groove forming surface 85 side via the prepared holes 83. Then, the electric discharge machining and the back flow are alternately repeated to form the slit grooves 81.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a honeycomb structure forming die for forming a ceramic honeycomb structure.

[0002]

2. Description of the Related Art A honeycomb structure forming die for extruding a ceramic honeycomb structure includes a plurality of supply holes for supplying a material, and a slit groove which communicates with the supply hole and forms the material into a honeycomb shape. And When manufacturing the honeycomb structure forming die, there is a method of performing electric discharge machining as a method of forming the slit groove.

In the electric discharge machining method, the discharge state is disturbed by increasing sludge (particles separated from an electrode or a mold material) generated by the electric discharge machining, and the width of the slit groove is made larger than a desired size. Or lower the processing speed.

On the other hand, Japanese Patent Application Laid-Open No. 2000-723 discloses a method in which electric discharge machining is performed while suctioning or injecting a machining fluid from a through-hole with suction or pressure in order to enhance sludge discharge during electric discharge machining. It is shown. According to this method, better electric discharge machining can be performed than in the case where the machining fluid is simply supplied.

[0005]

However, when manufacturing a die for forming a honeycomb structure, the above-mentioned conventional electric discharge machining method is still insufficient. In other words, the slit grooves in the honeycomb structure forming mold have a narrow groove width and a high groove formation density due to recent demands for a thinner honeycomb structure and a smaller cell. Further, the depth of the slit groove is very deep compared to the width dimension, and there are many portions having a bottom portion without finally communicating with the supply hole. for that reason,
In the case of slit groove machining, it is more difficult to increase the fluidity of the machining liquid than in the case of ordinary electric discharge machining in which relatively simple machining is performed. Therefore, a large amount of sludge generated during electric discharge machining is not sufficiently discharged simply by suctioning or injecting the machining fluid. Therefore, when the slit grooves of the honeycomb structure forming mold are formed by electric discharge machining, there is a problem that machining efficiency and machining accuracy cannot be significantly improved due to the influence of generated sludge.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is intended to manufacture a honeycomb structure forming mold capable of accurately and efficiently performing electric discharge machining of slit grooves of the honeycomb structure forming mold. It seeks to provide a way.

[0007]

According to the present invention, there is provided a honeycomb structure forming mold having at least a plurality of supply holes for supplying a material and a slit groove communicating with the supply hole to form a material into a honeycomb shape. In the method, after the supply hole is formed in the hole forming surface of the mold material, a part of the slit groove planned position on the groove forming surface opposite to the hole forming surface and the supply hole penetrate. A plurality of pilot holes are provided so as to face the electric discharge machining electrode to the groove forming surface, while supplying a machining liquid to the groove forming surface, and through the pilot hole from the groove forming surface side to the hole forming surface side. The electric discharge machining electrode is advanced while aspirating the machining fluid to advance the electric discharge machining, and then the electric discharge machining is stopped, the electric discharge machining electrode is retracted, and the slit groove in the middle of the machining is opened. The above hole formation through the hole Performs a reverse flow process which jet the machining fluid to exit from the side into the groove forming surface side, then,
A method for manufacturing a die for forming a honeycomb structure, wherein the slit groove is formed by alternately repeating the electric discharge machining and the backflow treatment (claim 1).

In the present invention, a plurality of pilot holes are provided so as to penetrate the slit groove planned position and the supply hole. Then, using the prepared hole, the electric discharge machining and the backflow treatment are alternately repeated. First, at the time of electric discharge machining, the sludge generated by electric discharge machining is discharged along with the flow of the machining liquid sucked from the groove forming surface side to the hole forming surface side through the pilot hole, and fresh machining liquid is discharged. The parts can be efficiently supplied.

[0009] However, it is difficult to completely discharge sludge through the pilot hole, and the amount of sludge remaining in the slit groove during machining gradually increases.
For this reason, the situation is likely to occur in which the sludge adversely affects the electric discharge machining. Here, in the present invention, the backflow process is performed. That is, as described above, the electric discharge machining is temporarily stopped, the electrode for electric discharge machining is retracted, and the slit groove in the middle of the machining is opened. Then, the flow of the machining fluid is reversed, and the machining fluid is jetted from the hole forming surface side to the groove forming surface side via the pilot hole. As a result, sludge remaining in the slit groove during processing is discharged to the outside. Therefore, when electric discharge machining is resumed, electric discharge machining can be resumed under favorable conditions with little residual sludge.

When the residual sludge increases again, the above-mentioned backflow treatment is performed again to remove sludge. Thereafter, the electric discharge machining is advanced by alternately repeating the electric discharge machining and the backflow treatment, so that a slit groove having a desired depth can be completed. As described above, according to the present invention, when machining the slit groove, the electric discharge machining is not performed continuously, but is stopped halfway, and the flow is resumed after the backflow process. Thus, the electric discharge machining can always be performed under favorable conditions, and the machining can be performed with higher precision and efficiency than when the electric discharge machining is continuously performed without performing the backflow treatment.

Therefore, according to the present invention, it is possible to provide a method for manufacturing a honeycomb structure forming die capable of accurately and efficiently subjecting a slit groove of the honeycomb structure forming die to electrical discharge machining. .

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The shape of the above-mentioned slit groove can be selected from a triangular lattice, a square lattice, a hexagonal lattice, and various other lattice shapes in accordance with the shape of the honeycomb structure to be formed. The supply hole is provided so as to communicate with all or a part of the grid intersection in the slit groove. The pilot hole is provided corresponding to at least a part of the plurality of supply holes.

In particular, it is preferable that the pilot hole is provided so as to penetrate all the supply holes. In this case, all the supply holes can be used for the flow path of the machining fluid, and the effect of discharging the sludge by suction of the machining fluid during the electric discharge machining and the effect of discharging the sludge in the backflow treatment are further enhanced. be able to.

Further, it is preferable that the slit grooves have a hexagonal lattice shape. When the slit grooves are in the form of a hexagonal lattice, for example, compared to the case of a square lattice,
It is difficult for the working fluid to flow along the grooves, and sludge tends to accumulate. Therefore, the alternating processing of the electric discharge machining and the backflow treatment is very effective. In addition, in the case of a hexagonal lattice, there is currently no method of machining a slit groove other than the electric discharge machining. Affects the manufacturing cost and quality of the product.

The width of the slit groove is 110 μm.
m or less (claim 4). In this case, in particular, the above-mentioned effects can be effectively exhibited. That is, when the width of the slit groove is 110 μm or less, it is difficult to enhance the sludge discharge effect. In this case, by performing the electric discharge machining and the backflow treatment alternately, the electric discharge machining accuracy and efficiency can be improved.

Further, the depth dimension of the slit groove can be ten times or more the width dimension thereof.
Also in this case, the above-described effects can be effectively exerted. That is, in the case of a slit groove having a narrow deep groove structure whose depth dimension is 10 times or more the width dimension, it is difficult to enhance the sludge discharge effect. Also in this case,
By performing the electric discharge machining and the backflow treatment alternately, electric discharge machining accuracy and efficiency can be improved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) FIGS.
This will be described with reference to FIG. In this example, as shown in FIGS. 1 and 2, a plurality of supply holes 81 for supplying a material,
8 for forming a honeycomb structure having a slit groove 82 for forming a material into a hexagonal lattice honeycomb shape in communication with the honeycomb structure.
To manufacture. In this example, as shown in FIG.
After the supply hole 81 is formed in the hole forming surface 84 of the zero, the pilot hole 83 is formed so that the supply hole 81 penetrates a part of the slit forming surface 85 on the groove forming surface 85 opposite to the hole forming surface 84. (FIG. 4) are provided in plurality.

Thereafter, the electric discharge machining electrode 1 faces the groove forming surface 85, the machining liquid 7 is supplied to the groove forming surface 85, and the groove forming surface 85 side to the hole forming surface 84 side through the pilot hole 83. The electric discharge machining electrode 1 is advanced while sucking the machining fluid 7 to perform electric discharge machining. Next, the electric discharge machining is stopped and the electric discharge machining electrode 1 is retracted to open the slit groove 82 in the middle of the machining, and the machining fluid 7 is drawn through the pilot hole 83 from the hole forming surface 84 side to the groove forming surface 85 side. Backflow processing for jetting is performed. Thereafter, the electric discharge machining and the backflow treatment are alternately repeated to form the slit grooves 82.

Hereinafter, this will be described in detail. In manufacturing a honeycomb structure forming die 8 to produce in this example, first, as shown in FIG. 3 (a), prepared mold material 80 having a groove-forming surface 85 and the hole formation surface 84 on the front and back I do.
Next, as shown in FIG. 3B, a large number of supply holes 81 are provided in the hole forming surface 84 of the die material 80 by drilling. In this example, a supply hole 81 having a diameter of 0.9 mm was provided.

Next, as shown in FIGS. 3 (c) and 4,
The pilot hole 83 is provided by using the laser beam 60 emitted from the laser processing device 6 so that the slit groove formation position 820 on the groove forming surface 85 opposite to the hole forming surface 84 and the supply hole 81 penetrate. Was. Further, in this example, the hexagonal lattice of the slit grooves is formed so as to penetrate all the supply holes 81.
Prepared holes 83 were provided in three of the three corners. The pilot hole 83 (FIG. 4) in this example had a diameter of 140 μm.

Then, as shown in FIGS. 1, 2 and 3D, hexagonal lattice-shaped slit grooves 82 are formed by electric discharge machining. As a result, a honeycomb structure forming die 8 having a large number of hexagonal lattice-shaped slit grooves 82 on a groove forming surface 85 protruding from the peripheral portion 88 is obtained. In this example, as shown in FIG. 2A, the width dimension W of the slit groove 82 was 100 μm, and the depth dimension D was 2.5 mm.

Here, in this embodiment, in forming the slit groove 82, the electric discharge machining and the backflow treatment are alternately repeated. First, as shown in FIG.
This was performed using the electric discharge machine 5. This electric discharge machine 5
Has a base portion 51 disposed in a tank 50 and a suction device 52 incorporated therein, and is configured to set a mold material 80 on the upper surface of the suction device 52. Also,
Above the mold material 80, an electric discharge machining electrode 1 is fixed to a head (not shown) and supported so as to be movable up and down, left and right. The electrodes 15 of this electrode 1 for electric discharge machining are provided in a hexagonal lattice shape according to the shape of the slit groove to be obtained.

A voltage is applied between the electric discharge machining electrode 1 and the mold blank 80 by a power supply 55. Further, the machining liquid 7 is filled in the tank 50 so that the portion below the electrode 1 for electric discharge machining is sufficiently immersed. Outside the tank 50, two external tanks are provided. Clean tank 5 storing clean working fluid 7
51 and a dark tank 552 for storing the used working fluid 7 containing sludge. These include pipes 561-5
64, the electrode 1 for electric discharge machining and the suction device 52
Is connected.

Specifically, the electric discharge machining electrode 1 is connected to a clean tank 551 via a pipe 561. A pump 57 provided in the middle of the pipe 561
1 is configured so that a fresh machining liquid 7 can be supplied from the clean tank 551 to the electric discharge machining electrode 1.

A pipe 56 connected to the suction device 52
2 is connected to two pipes 563 and 564 through a three-way valve 565.
And are connected to a dark tank 552 and a clean tank 551, respectively. A pump 572 is provided in the middle of the pipe 562. By switching the three-way valve 565 and changing the feed direction of the pump 572, the flow direction of the working fluid 7 is changed from the suction device 52 to the dark tank 552 and the clean tank 5
It is configured so that it can be changed from 51 to a suction device 52.

In performing the electric discharge machining using the electric discharge machining apparatus 5 having the above configuration, as shown in FIG. 5, the electric discharge machining electrode 1 faces the mold material 80, and a voltage is applied between the two. Fresh machining fluid 7 from the EDM electrode 1 side
Machining electrode 1 while gradually supplying
To move forward. Further, at this time, the hole forming surface 8 is moved from the groove forming surface 85 side through the pilot hole 83 by the suction device 52.
The working fluid 7 is sucked to the side 4. Thereby, the groove forming surface 85
In, the slit groove 82 is gradually formed, and most of the generated sludge is discharged to the dark tank 552 together with the sucked processing liquid 7.

In this embodiment, the electric discharge machining is not continuously performed until the slit groove 82 is completed, but the electric discharge machining is temporarily stopped, and the supply and suction of the machining fluid are stopped. The timing of stopping the electric discharge machining is before the amount of sludge remaining in the slit groove 82 during machining increases and starts to have a bad influence on the electric discharge machining. The specific timing can be obtained experimentally, for example.

Next, as shown in FIG. 6, the electric discharge machining electrode 1 is retracted upward to open the slit groove 2 which is being processed. Then, switching of the three-way valve 565 and the pump 5
The reverse rotation of 72 is started, and the fresh processing liquid 7 is sent from the clean tank 551 to the suction device 52 by pressure. Thereby, the backflow process of jetting the working fluid 7 from the hole forming surface 84 to the groove forming surface 85 through the pilot hole 83 can be performed. As a result, sludge remaining in the slit groove 82 during processing is removed upward by the reverse flow of the fresh processing liquid 7. Therefore, when electric discharge machining is restarted, electric discharge machining can be restarted under favorable conditions with little residual sludge.

In this embodiment, the cycle of performing the electric discharge machining for 1 hour and then performing the backflow treatment for 5 seconds was alternately repeated. As a result, a hexagonal lattice-shaped slit groove 82 having the above width and depth dimensions was formed.
As described above, in this example, when machining the slit groove 82, the electric discharge machining is not performed continuously, but is stopped halfway, and the flow is restarted after performing the backflow process. by this,
Accurate electric discharge machining can always be performed, and machining can be efficiently performed rather than performing electric discharge machining continuously without performing backflow processing.

(Embodiment 2) In this embodiment, in order to quantitatively evaluate the excellent effects of Embodiment 1, two types of EDM methods (Comparative Examples 1 and 2) for comparison were carried out. The processing time was compared with the case of Example 1. Comparative Example 1 is an example in which backflow treatment was omitted in the method of Example 1 and electric discharge machining was continuously performed. Comparative Example 2 is a mold material 80 according to Example 1.
This is an example in which electric discharge machining is continuously performed without providing a pilot hole and without performing suction and backflow treatment of a machining fluid.

FIG. 7 shows the results of these processes. The figure shows
The horizontal axis represents time, and the vertical axis represents the depth of the slit groove. In the figure, the result of Example 1 is shown as E1, the result of Comparative Example 1 is shown as C1, and the result of Comparative Example 2 is shown as C2. As can be seen from the figure, at the stage immediately after the start of processing, Comparative Example 1 was most efficiently processed, and Comparative Example 2 was the second. In Example 1, the processing speed was the lowest at the stage immediately after the start of processing. However,
In the first embodiment, the processing efficiency is improved by reversing the comparative example 2 in the initial stage, and thereafter, the processing efficiency is further improved by reversing the comparative example 1, and finally the processing of the slit groove is advanced with the highest efficiency. I was able to.

This is considered as follows. In other words, immediately after the start of machining, the increase in the residual amount of sludge generated by electric discharge machining has not yet progressed so much, so that the comparative examples 1 and 2 in which the above-mentioned backflow treatment is not performed can proceed electric discharge machining more efficiently. .

However, when the residual sludge amount gradually increases, the working efficiency of Comparative Examples 1 and 2 decreases. In particular, Comparative Example 2, which does not have the above-mentioned pilot hole, has a large influence because suction during electric discharge machining cannot be performed. On the other hand, in the case of the first embodiment, by performing the above-mentioned backflow treatment, the electric discharge machining can always be efficiently performed, and the efficiency does not decrease. Rather, as processing proceeds, the distance between the pilot holes 83 decreases, suction efficiency increases, and processing efficiency also tends to increase. Therefore, as described above, the overall processing efficiency of the embodiment 1 (E1) and the comparative example 1 (C1) and the comparative example 2 (C2) is reversed at the stage where the processing is advanced.

From the above results, it can be seen that repeating the electric discharge machining and the backflow treatment as in the first embodiment is very effective when machining the slit grooves 82 of the honeycomb structure forming die 8. . In this example, the quantitative evaluation of the processing accuracy was omitted.
Was able to process slit grooves with higher processing accuracy.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing (a) an overall shape and (b) a state in which a slit groove is formed in a mold for forming a honeycomb structure in Example 1.

FIG. 2A is a partially cutaway perspective view showing the relationship between a groove forming surface of a mold for forming a honeycomb structure and a supply hole in Example 1, and FIG.

FIG. 3 is an explanatory view showing a manufacturing process of a honeycomb structure forming mold in Example 1.

FIG. 4 is an explanatory diagram showing a formation position of a pilot hole in the first embodiment.

FIG. 5 is an explanatory diagram showing a state in which electric discharge machining is performed in the first embodiment.

FIG. 6 is an explanatory diagram illustrating a state in which a backflow process is performed in the first embodiment.

FIG. 7 is an explanatory diagram showing a relationship between a processing time and a groove depth in the second embodiment.

[Explanation of symbols]

 1. . . 14. electrode for electric discharge machining, . . Electrodes, 5. . . 6. electric discharge machine, . . Processing fluid, 8. . . Honeycomb structure forming die, 80. . . Mold material, 81. . . Supply hole, 82. . . Slit groove, 83. . . Pilot hole, 84. . . Hole forming surface, 85. . . Groove forming surface,

Claims (5)

[Claims] 1. A method for manufacturing a honeycomb structure forming mold having at least a plurality of material supply holes and a slit groove communicating with the supply holes to form a material into a honeycomb shape. After the supply hole is formed in the hole forming surface of the mold material, the pilot hole is formed so that a part of the slit groove planned position on the groove forming surface opposite to the hole forming surface and the supply hole penetrate. A plurality of the machining fluids are provided to face the EDM electrode to the groove forming surface, while supplying the machining fluid to the groove forming surface, and by passing the machining fluid from the groove forming surface side to the hole forming surface side through the pilot hole. The electric discharge machining electrode is advanced by suction while the electric discharge machining is advanced, then the electric discharge machining is stopped, and the electric discharge machining electrode is retracted to open the slit groove in the middle of the machining, and the above-mentioned through the pilot hole. The above groove shape from the hole forming side Back-molding processing for jetting the machining fluid so as to flow out to the surface side, and thereafter, the electric discharge machining and the back-flow treatment are alternately repeated to form the slit grooves, thereby forming a honeycomb structure forming metal. Mold manufacturing method. 2. The method according to claim 1, wherein the pilot hole is provided so as to penetrate all the supply holes. 3. The method according to claim 1, wherein the slit groove has a hexagonal lattice shape. 4. The method according to claim 1, wherein:
A method for manufacturing a die for forming a honeycomb structure, wherein a width dimension of the slit groove is 110 μm or less. 5. The method according to claim 1, wherein:
A method for manufacturing a die for forming a honeycomb structure, wherein a depth dimension of the slit groove is at least 10 times a width dimension thereof.