JP3099160B2 - Manufacturing method of honeycomb molding die - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a honeycomb forming die for forming a honeycomb body such as a catalyst carrier for an automobile.

[0002]

2. Description of the Related Art Various types of catalyst carriers for automobiles are known. Among them, a honeycomb body having a honeycomb structure is known for its large surface area and high structural strength. Further, the honeycomb body is formed by extruding a honeycomb material including, for example, a ceramic powder and a binder using a honeycomb molding die.

[0003] The honeycomb forming die corresponds to a cross-sectional shape of a honeycomb body to be formed, and has a forming hole formed by a plurality of cell holes communicating with each other, and a honeycomb material is pressed and fed into each of the cell holes. (See FIGS. 6 to 9). Various shapes such as a triangle and a quadrangle have been proposed for the cell hole in the honeycomb molding die.

Meanwhile, as a conventional die for forming a honeycomb, there is a die shown in Japanese Patent Publication No. 62-36847. This honeycomb molding die is for producing a honeycomb body having a square cross section. A plurality of square cell blocks having a cross section (square) corresponding to the cells (squares) of the honeycomb body are respectively formed on a die base. It is fixed with screws or the like. Between the cell blocks,
A formed hole composed of a large number of square cell holes is formed.

[0005]

On the other hand, particularly when the honeycomb body has a cross section of a complicated shape such as a hexagonal shape, the structure of a honeycomb molding die for manufacturing such a honeycomb body becomes complicated. That is, in this case, the forming holes for extruding the honeycomb material are formed by combining a number of hexagonal cell holes (see FIGS. 2C and 6 to 9).

For this reason, it is difficult to form a molded hole composed of a large number of hexagonal cell holes with a plurality of cell blocks as in the above-described conventional technique. Furthermore, in the above method, a large number of cell blocks must be fixed to the die base with screws or the like, and the operation is complicated. In particular, it is difficult to fix a large number of hexagonal cell blocks to a die base and to form hexagonal cell holes between the fixed cell blocks.

The reason is that, in the case of a rectangular cell hole as described above, the correction in the vertical and horizontal directions is sufficient, but in the case of a hexagonal cell hole, correction in multiple directions is required, and the cell block is fixed. Is difficult. What is more difficult is that
In a honeycomb body that requires a very fine grid pitch, such as a catalyst carrier for an automobile, the width of a cell hole of a honeycomb forming die for forming the same is very small.

For example, in the case of the above-mentioned automobile catalyst carrier, the pitch of the lattice of the honeycomb body is as small as about 1.27 mm. The thickness of the lattice is, for example, about 0.
Very thin, 2 mm. Therefore, in order to form such a thin honeycomb body, the width of the cell hole is very small. The reason why the catalyst carrier for automobiles requires such a small lattice pitch and wall thickness is that the contact area with the exhaust gas should be as large as possible.

[0009] As is known from the above, forming a honeycomb body having a complex shape such as a hexagonal cell as a catalyst carrier for an automobile, and manufacturing a mold for forming a honeycomb for forming such a honeycomb body include: With very difficult techniques. The present invention has been made in view of the conventional problems, and provides a method for manufacturing a honeycomb molding die capable of accurately and easily manufacturing a honeycomb molding die having a plurality of forming holes formed by cell holes. What you want to do.

[0010]

According to the present invention, there is provided a molded hole constituted by a plurality of hexagonal cell holes which correspond to the cross-sectional shape of a honeycomb body to be molded and communicate with each other, and a honeycomb formed in each of the hexagonal cell holes. Having a feed passage for pressing and feeding the material, in manufacturing a honeycomb forming die, an electrode plate for manufacturing a discharge electrode, a plurality of the honeycomb body according to the interval of the hexagonal cell holes of the honeycomb body. A first step of forming a through hole;
A plurality of hexagonal cut holes having an internal shape corresponding to the internal shape of the hexagonal cell hole are formed by a wire cut method in which a wire having a circular cross section is inserted and a current is applied between the wire and the electrode plate. A second step of forming and forming a discharge electrode in which a honeycomb-shaped electrode is formed between the plurality of cut holes; A third step of forming, and facing a discharge electrode having the honeycomb-shaped electrode formed on the front surface of the mold plate, forming the hexagonal cell hole by electric discharge machining, The fourth step of making the honeycomb molding die by communicating with the passage.
And a method for manufacturing a honeycomb molding die.

In the present invention, it is most remarkable that a first step of forming the through hole in an electrode plate for producing a discharge electrode, and a wire having a circular cross section in the through hole. A second step of forming a hexagonal cut hole corresponding to the hexagonal cell hole by inserting the above wire cut method to form a discharge electrode having a honeycomb-shaped electrode;
A third method in which the inlet passage is formed in advance in the mold plate
And forming a hexagonal cell hole communicating with the feed passage by performing discharge machining on the mold plate from the opposite side of the feed passage using the discharge electrode formed with the honeycomb-shaped electrode. And performing the fourth step.

The cell hole has a hexagonal shape . The shape of the cell hole can be formed by forming a hexagonal cut hole using the wire cutting method in the second step. The mold plate is a material for forming a honeycomb forming mold, and the electrode plate is a material for forming the discharge electrode for electric discharge machining.

A material such as a steel plate is used for the mold plate. A material such as carbon, a copper plate, or a copper alloy is used for the electrode plate. In the wire cutting method, first, a wire having a circular cross section is penetrated into the through hole of the electrode plate, and a current is applied between the wire and the electrode plate to move the wire in a hexagonal shape. It is a method of cutting.

[0014] In addition, the width of the top Kise Le holes 0.1~0.5m
m is preferable. When the thickness is less than 0.1 mm, when a honeycomb body formed using the honeycomb forming mold is fired, it may be broken. On the other hand, 0.5m
If it exceeds m, the thickness of the lattice (which is smaller than the width of the cell hole due to firing of the honeycomb material) in the honeycomb body formed using the honeycomb forming die and then fired is large, and the entire honeycomb body is Surface area is reduced. In particular, when manufacturing a honeycomb molding die for molding an automobile catalyst carrier, it is preferable that the width of the cell hole be within the above range.

In the above case, the depth of the cell hole is 2-7.
mm is preferable. If it is less than 2 mm, since the depth of the cell holes is small, it is difficult to connect the lattices when extruding a hexagonal honeycomb body. On the other hand, if it exceeds 7 mm, the extrusion molding pressure becomes too high, and the lattice of the honeycomb body may be broken.

[0016]

In the present invention, a plurality of the above-mentioned through holes are first formed in the electrode plate in the first step. Then, in a second step, starting from the above through hole with <br/> wire cutting method using a circular cross section wire, corner
Forms a large number of hexagonal cut holes in an arc shape by a wire cutting method . The cut hole has a hexagonal inner shape corresponding to the inner shape of the cell hole. As a result, a discharge electrode having a honeycomb-shaped electrode is produced.

On the other hand, in the third step, the above-mentioned feed passage is formed in the mold plate from the back side to the middle by a drill or the like. This inlet passage corresponds to the lattice pitch of the honeycomb body to be obtained. Since the third step is separate from the first or second step, it is usually performed in parallel with these steps.

Next, in a fourth step, the discharge electrode having the honeycomb-shaped electrode formed in the second step is placed on the opposite side (front side) of the mold plate from the inlet passage. They are made to face each other, electricity is applied between them, and electric discharge machining is performed. As a result, hexagonal cell holes are formed and hexagonal
Thus, a honeycomb molding die in which the cell holes communicate with the feed passages is obtained.

As described above, in the present invention, a honeycomb-shaped electrode is formed by using the above-described wire cutting method.
The discharge electrode is manufactured, and a discharge passage is formed in the mold plate in advance, and thereafter, the discharge machining is performed with the two facing each other, so that the honeycomb forming mold can be easily manufactured. In the wire cutting method, a hexagonal cut hole can be formed by moving the wire in a hexagonal shape . Therefore, a discharge electrode having a honeycomb-shaped electrode having hexagonal cell holes can be manufactured.

Therefore, the shape of the hexagonal cut hole is also accurate, and therefore, by using a discharge electrode having a honeycomb-shaped electrode having a large number of such hexagonal cut holes with high accuracy, the accuracy is improved. It is possible to easily manufacture a honeycomb molding die having a large number of hexagonal cell holes with good quality. Furthermore, the discharge electrode is formed by the wire cut method.
The hexagonal corners are easily formed in an arc shape.
Can be Therefore, the obtained hexagonal honeycomb corners
Can also be in the shape of a circular arc, the strength of the hexagonal honeycomb
Can improve itself. As described above, according to the present invention, a honeycomb mold having a mold cavity formed by the hexagonal multiple cells hole, Ki accurately and easily is de to produce, furthermore, strength Excellent
The present invention can provide a method for manufacturing a honeycomb molding die capable of obtaining a honeycomb body having a reduced thickness.

[0021]

【Example】

Example 1 A method for manufacturing a honeycomb molding die according to an example of the present invention will be described with reference to FIGS. First of all,
A honeycomb forming mold to be manufactured in this example will be described with reference to FIGS. As shown in FIG. 6, this honeycomb molding die 30 has a hexagonal cell hole 32.
Are formed and formed in a large number. That is, the honeycomb forming mold 30 has a forming hole 320 corresponding to the cross-sectional shape of the honeycomb body to be formed and formed by a plurality of cell holes 32 communicating with each other, and the honeycomb material 4 ( 9) is provided.

The inlet passage 31 has a circular shape and is shown in FIGS.
As shown in the figure, three hexagonal cell holes 32 are opened at portions adjacent to each other. FIG. 7 shows a front view of a honeycomb molding die, that is, a front surface from which a honeycomb material is extruded. On the other hand, FIG. 8 is a rear view of the honeycomb molding die, that is, the feed passage 3 for pressing and feeding the honeycomb material.
The back side of one side is shown.

Next, a method of manufacturing the honeycomb molding die 30 will be described. In the present embodiment, the discharge electrode 10 is opposed to the mold plate 3 for manufacturing the honeycomb mold 30 (FIG. 1C, FIGS. 6 to 9), and the electric discharge machining (FIG. 2B) is performed. This is a method for manufacturing a honeycomb molding die for processing the cell holes 32. This manufacturing method includes the following first to fourth steps. First, in the first step, as shown in FIG. 1, an electrode plate 1 (FIG. 1A) for preparing the discharge electrode 10 is prepared, and according to the interval (pitch) of the cell holes 32 of the honeycomb body. A plurality of through holes 11 are formed by using a drill (FIGS. 1B and 3).

Next, in the second step, as shown in FIGS. 1C and 1D, a cross section is formed in the through hole 11 of the electrode plate 1.
Insert the circular wire 2 as shown in FIGS. 1C and 4
The wire 2 is inserted through the through hole 11 and
And the electrode plate 1 is energized. This wire cutter
Many hexagonal cuts whose corners are arc-shaped by the G method
The discharge electrode 10 (FIG. 1D, FIG. 5) in which the hole 12 was formed was formed.
Can be manufactured.

Then, as shown in FIG. 4, the electrode plate 1 is cut into a hexagon while the wire 2 is moved in a hexagon to form a hexagonal cut hole 12. The wire 2 is sequentially fed into a number of through holes 11 to form the cut holes 12 respectively. The cut hole 12 is
The honeycomb mold 30 has an inner shape corresponding to the inner shape of the cell hole 32. Thereby, as shown in FIG. 2B and FIG. 5, the discharge electrode in which the electrode (the same cross-sectional shape as the hexagonal honeycomb body) corresponding to the cell hole 32 of the honeycomb forming die is formed between the plurality of cut holes 12 is formed. It is made.

Next, in the third step, regardless of the first and second steps, for example, in parallel with these steps, as shown in FIG. The feeding passage 31 is formed halfway by drilling. The pitch of the inlet passage 31 corresponds to the pitch of the cell holes.

Next, in a fourth step, as shown in FIG. 2B, the discharge electrode 10 is made to face the front surface of the mold plate 3 provided with the inlet passage 31. Then, a current is applied between the discharge electrode 10 and the mold plate 3,
The cell holes 32 are formed by electric discharge machining. This cell hole 32
Reaches the inlet passage 31 and both communicate with each other. As a result, the honeycomb molding die 30 shown in FIG. 2C and FIGS. 6 to 9 is obtained.

As described above, according to this embodiment, the discharge electrode 10 is manufactured by using the above-described wire cutting method, while the insertion passage 31 is formed in the mold plate 3 in advance, and the discharge passage 10 is formed by facing the two. A honeycomb molding die is manufactured by processing. Therefore, it is easy to manufacture a honeycomb molding die. The cut holes 12 formed in the discharge electrode 10 are:
Since the wire 2 having a circular cross section can be arbitrarily formed by moving the wire 2 in a hexagonal shape, a discharge electrode corresponding to the cell hole 32 can be manufactured with high accuracy, and the corner has an arc shape.
Can be Therefore, the cell holes 32 of the honeycomb molding die have high accuracy and improved strength.
The body can be obtained easily.

Example 2 This example shows a specific example of the method for manufacturing the honeycomb molding die shown in Example 1 above. In the present example, the hexagonal cell holes in the honeycomb molding die had a width of 0.18 mm and a cell pitch of 1.3 mm. The depth of the cell hole is 3mm, and the depth of the inlet passage is 10mm
The two parts penetrate each other for about 0.5 mm (Fig. 2
C). This is to ensure that both are communicated.

In the first step, the thickness of the electrode plate was 15 mm, and the diameter of the through hole was 1.0 mm.
In the second step, the diameter of the wire having a circular cross section was about 0.1 mm, and a current of 1.2 A and a voltage of 70 V were applied between the wire and the electrode plate (carbon material).
In the third step, the maximum depth of the inlet passage is as described above. In the fourth step, the electric discharge conditions applied between the electric discharge electrode and the mold plate during electric discharge machining are as follows:
~ 2A, voltage 80V.

As shown in FIG. 9, the honeycomb molding die 3 manufactured as described above was used.
The honeycomb material 4 for forming a honeycomb body was pressed and fed from the side of the feed passage 31 of the No. 0 to prepare a honeycomb body. The honeycomb body had an accurate hexagonal lattice.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a process for manufacturing a discharge electrode in Example 1.

FIG. 2 is an explanatory view showing the steps of manufacturing an electrode plate and manufacturing a mold for forming a honeycomb by electric discharge machining in Example 1.

FIG. 3 is a front view of an electrode plate provided with through holes according to the first embodiment.

FIG. 4 is an explanatory diagram of a wire cutting method in the first embodiment.

FIG. 5 is a front view of a discharge electrode according to the first embodiment.

FIG. 6 is a front view of a honeycomb molding die according to the first embodiment.

FIG. 7 is an enlarged partial front view of a honeycomb molding die according to the first embodiment.

FIG. 8 is an enlarged partial back view of the honeycomb molding die according to the first embodiment.

FIG. 9 is an explanatory view at the time of forming a honeycomb body in the first and second embodiments.

[Explanation of symbols]

 1. . . Electrode plate, 10. . . 10. discharge electrode, . . 11. through-hole, . . Cut holes, 2. . . Wire, 3. . . Mold plate, 30. . . 30. Honeycomb molding die, . . Entrance passage, 32. . . Cell hole, 320. . . Molding holes, 4. . . Honeycomb material,

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Osamu Machida, Inventor 1-1-1, Showa-cho, Kariya-shi, Aichi, Japan Inside Denso Co., Ltd. (72) Inventor Kinichi Ishikawa 1-1-1, Showa-cho, Kariya-shi, Aichi, Japan Denso Co., Ltd. (56) References JP-A-63-28522 (JP, A) JP-A-61-71917 (JP, A) JP-A-63-67034 (JP, A) JP-A-4-269121 (JP, A) Japanese Patent Publication 1-25652 (JP, B2) Japanese Patent Publication 1-40730 (JP, B2) Japanese Patent Publication 4-6488 (JP, B2)

Claims (4)

(57) [Claims] 1. A forming hole formed by a plurality of hexagonal cell holes corresponding to a cross-sectional shape of a honeycomb body to be formed and communicating with each other, and a honeycomb material is pressed and fed into each of the hexagonal cell holes. Having an entrance passage for
A first step of forming a plurality of through-holes in an electrode plate for forming a discharge electrode in accordance with an interval between hexagonal cell holes of the honeycomb body; A plurality of hexagons having an internal shape corresponding to the internal shape of the hexagonal cell hole are formed by inserting a wire having a circular cross section through the through hole of the plate and conducting a current between the wire and the electrode plate. A second step of forming a cut electrode having a shape and forming a discharge electrode in which a honeycomb-shaped electrode is formed between the plurality of cut holes; and A third step of forming an inlet passage in advance, and a discharge electrode having the honeycomb-shaped electrode formed on the front surface of the mold plate, and forming the hexagonal cell hole by electric discharge machining. A method for producing a honeycomb molding die by making the cell hole communicate with the above-mentioned feed passage. 2. The method according to claim 1, wherein the width of the cell hole is 0.05 to 2 mm. 3. The method according to claim 1, wherein:
A method for manufacturing a honeycomb molding die, wherein the depth of the cell hole is 0.5 to 10 mm. 4. The method according to claim 1, wherein the discharge electrode is a carbon material.