JPH1177189A - Mold manufacturing method - Google Patents

Abstract

(57) [Problem] To provide a method of manufacturing a mold, which can reliably prevent meandering of a slit groove while maintaining soundness of a communication portion between a supply hole and a slit groove obtained. . SOLUTION: This is a method for manufacturing a mold having a supply hole 4 for supplying a material and a slit groove 2 provided in communication with the supply hole 4. A mold material 10 having a groove forming surface 11 for forming a slit groove 2 and a hole machining surface 14 for providing a supply hole 4 on the front and back is prepared. A short shallow hole 40 is provided. Next, the supply hole 4 is formed by making the shallow hole 40 longer by performing non-contact processing for removing the tip portion 401 of the shallow hole 40.

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 mold having a slit groove of an extremely narrow width, such as a mold for forming a thin honeycomb structure.

[0002]

2. Description of the Related Art For example, a honeycomb structure 8 as shown in FIG. 9 described below is used as a catalyst carrier in a converter for purifying exhaust gas of an automobile or the like. As shown in FIG. 10, the honeycomb structure 8 has many cells 82 by cell walls 81 formed in a lattice.

[0003] The manufacture of such a honeycomb structure 8 is performed by extrusion molding. The molding die used at this time is a mold 1 for forming a honeycomb structure, as shown in FIGS.
And a guide ring 19 combined therewith. As shown in FIGS. 5 to 8, which will be described later, the mold 1 for forming the honeycomb structure has a supply hole 4 for supplying the material on the surface on the material receiving side, and has a grid on the extrusion surface 18 on the opposite side. It has a slit groove 2 in a shape.
The slit grooves 2 are arranged so as to communicate with the supply holes 4 at the lattice points.

At the time of extrusion molding, as shown in FIG. 6, a material 88 is supplied from the supply hole 4 side of the mold 1, and the honeycomb structure 8 is continuously extruded from the slit groove 2. The extruded honeycomb structure 8 is sequentially cut into appropriate lengths,
Then, it is commercialized by drying.

Next, a conventional method for manufacturing the mold 1 used for the extrusion molding will be described. First, as shown in FIG. 11A, a mold material 10 to be a material of the mold 1 is prepared.
As shown in FIG. 1, the mold material 10 is provided in advance with a groove forming surface 11 on which a slit groove is to be formed protruding. The groove forming surface 11 has a square outer shape at this stage.

Next, as shown in FIG. 11 (b), a supply hole 4 is formed from a surface (hole machining surface) 14 of the mold material 10 opposite to the groove forming surface 11 by drilling, electric discharge machining, electrolytic machining or the like. . Next, as shown in FIG. 11C, the slit groove 2 is provided on the groove forming surface 11 of the die material 10. Next, the square outer shape of the groove forming surface 11 is cut into a circular shape to obtain the honeycomb structure forming die 1 having the circular extrusion surface 18 as shown in FIG.

In forming the slit groove 2, a circular thin blade grindstone 7 is used as shown in FIG. 11 is performed by grinding. Then, the work is repeated a plurality of times vertically and horizontally by the number of slit grooves, whereby the lattice-shaped slit grooves 2 can be obtained.

[0008]

However, the above-mentioned conventional method for manufacturing the honeycomb structure forming die 1 has the following problems. That is, in the conventional manufacturing method, the supply hole 4 is provided to a predetermined depth in advance, and then the slit groove 2 having a predetermined depth is provided, so that the supply hole 4 communicates with the slit groove 2. The slit groove 2 is formed using the circular thin blade grindstone 7 as described above, and is formed while cutting the tip end of the supply hole 4 with the circular thin blade grindstone 7.

On the other hand, the circular thin blade grindstone 7 has a thickness of, for example, 150 μm or less, and is extremely thin. Therefore, when the balance of the resistance from the left and right is out of order when the tip of the supply hole 4 is cut, the grinding is performed while the circular thin blade grindstone 7 itself is meandering to one side.

[0010] In this case, there arises a problem that the circular thin blade grindstone 7 is broken and the mold material 10 is further damaged. In addition, when the meandering of the slit groove 2 is severe, the gap between adjacent slit grooves 2 varies, and
This adversely affects the accuracy of the formed honeycomb structure.

On the other hand, it is conceivable to adopt a method in which the slit groove 2 is provided first and the supply hole 4 is formed later.
However, in this case, in the portion of the supply hole 4 communicating with the slit groove, processing sagging, burrs, and the like protruding inside the slit groove 2 are generated. In addition, it is difficult to remove these drippings, burrs, and the like thereafter. Therefore, such a mere change of the processing order cannot provide a sufficient measure against the above problem.

Further, as shown in, for example, JP-A-58-217308, a slit groove forming portion and a supply hole forming portion are formed from separate metal plates, respectively.
Then, it is conceivable to take measures by a method of joining the two. However, in this case, the number of processing steps is doubled, and the production cost is significantly increased.

[0013] Such a problem is not limited to the above-described mold for forming a honeycomb structure, but also to a mold for forming various molded articles (ceramic molded articles, resin molded articles, etc.) having thin walls. Also occurs.

The present invention has been made in view of such a conventional problem, and it is possible to reliably prevent the slit groove from meandering while maintaining the soundness of a communication portion between the obtained supply hole and the slit groove. It is an object of the present invention to provide a method for manufacturing a metal mold.

[0015]

According to a first aspect of the present invention, there is provided a method of manufacturing a mold having a supply hole for supplying a material and a slit groove provided in communication with the supply hole, wherein the slit groove is formed. A mold material having a groove forming surface and a hole machining surface on which the supply hole is provided is prepared. The slit material is provided in the mold material, and a shallow hole shorter than the supply hole is provided. A method for manufacturing a mold, characterized in that the supply hole is formed by elongating the shallow hole by performing non-contact processing for removing the tip of the shallow hole.

The most remarkable point in the present invention is that the mold material is provided with the slit groove and the shallow hole.
Non-contact processing for removing the tip of the shallow hole. That is, the supply hole is formed by a two-step process,
The second step is to complete a supply hole sufficiently communicating with the slit groove by the non-contact processing.

The processing of the shallow hole in the die material can be performed, for example, by drilling. At this time, the shallow hole is
The length is set slightly shorter than the desired length of the supply hole. That is, the above-mentioned shallow hole is obtained by slightly reducing the depth of the supply hole.

On the other hand, a slit groove is provided on the groove forming surface of the mold material. The formation of this slit groove is performed by grinding using, for example, a circular thin blade grindstone as in the related art.
The order of forming the shallow holes and forming the slit grooves is not particularly limited. However, when quenching and hardening the mold material before forming the slit groove, it is preferable to form the slit groove after forming the shallow hole.

The non-contact processing is performed after the formation of the shallow hole and the slit groove is completed. The non-contact processing referred to here refers to a processing method excluding a processing method in which a tool is directly contacted with a mold material, such as a grinding processing or a cutting processing. Specifically, there are various methods for removing a processed portion by a chemical reaction, a thermal action, or the like, such as electrolytic processing and electric discharge processing described later.

Next, the operation and effect of the present invention will be described.
In the present invention, the shallow hole and the slit groove are first provided in the mold material, and then the non-contact processing is performed to complete the supply hole. For this reason, the slit groove can be provided with high precision without causing the meandering as in the related art.

That is, in the case where the slit groove is provided before the shallow hole, the work of cutting the tip of the supply hole at the time of grinding as in the prior art is not required since the solid mold material is ground. Therefore, a grinding tool such as a circular thin blade grindstone does not receive biased resistance, and a slit groove can be formed straight without meandering.

When a shallow hole is provided first and a slit groove is provided thereafter, the shallow hole is provided shorter than the supply hole. Therefore, similar to the case where a shallow hole is provided later, a tool such as a circular thin blade grindstone does not receive resistance biased in one direction, and a straight slit groove having almost no meandering can be provided. As described above, since the meandering does not occur at the time of forming the slit groove as in the related art, a tool such as a circular thin blade grindstone for performing the grinding process may be damaged,
There is no damage to the mold material.

The supply hole is finished by performing the non-contact processing. As described above, this non-contact processing is performed by using a chemical reaction, thermal action, or the like without directly contacting the processing tool with the mold material. Therefore, unlike the conventional drilling, the tip of the shallow hole can be removed without causing sagging or burrs at the lap portion between the supply hole and the slit groove. Therefore, the wrap portion between the slit groove and the supply hole, that is, the communication portion is finished in a very healthy state.

Therefore, according to the present invention, while maintaining the soundness of the communicating portion between the obtained supply hole and the slit groove,
It is possible to provide a method for manufacturing a mold, which can surely prevent meandering of a slit groove.

Next, as in the second aspect of the present invention, the non-contact processing can be performed by any one of electrolytic processing, electric discharge processing, and laser processing. Among them, in particular, according to the electrolytic processing, a plurality of shallow holes can be processed at once by the number of prepared electrodes, so that non-contact processing can be performed efficiently.

According to a third aspect of the present invention, the length of the shallow hole is 0.05 to 2.0 m longer than the length of the supply hole.
It is preferably shorter by m. If the difference in length is less than 0.05 mm, the shallow hole and the slit groove overlap in a relatively wide range during slit processing, and there is a problem that the effect of forming the shallow hole is reduced. On the other hand, 2.0mm
In the case where the number exceeds the limit, there is a problem that the processing amount of the non-contact processing increases and the production efficiency decreases.

Further, as molds manufactured by the above-mentioned manufacturing method, various molds for molding molded articles can be applied. According to a fourth aspect of the present invention, the metal mold includes a supply hole for supplying a material, and a slit groove provided in a lattice shape in communication with the supply hole for forming the material into a honeycomb shape. Can be applied. In this case, a large number of slit grooves can be smoothly processed as described above, and the manufacture of the honeycomb structure forming mold can be performed more efficiently than in the past.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment A method for manufacturing a mold according to an embodiment of the present invention will be described with reference to FIGS. The manufacturing method of this example is shown in FIG.
As shown in FIG. 8, a honeycomb structure forming metal having a supply hole 4 for supplying a material and a slit groove 2 provided in a lattice shape and communicating with the supply hole 4 for forming the material into a honeycomb shape. This is a method for manufacturing the mold 1.

First, the groove forming surface 11 for forming the slit groove 2
A mold material 10 having a front and a back and a hole machining surface 14 on which a supply hole 4 is provided is prepared. Then, the slit groove 2 is provided in the mold material 10 and a shallow hole 40 shorter than the supply hole 4 is provided. Next, the supply hole 7 is formed by elongating the shallow hole 40 by performing non-contact processing for removing the tip 41 of the shallow hole 40.

Further, as shown in FIGS. 9 and 10, the mold 1 manufactured in this embodiment has a cell wall 8 forming a cell 82. As shown in FIG.
This is for extruding a very thin honeycomb structure 8 having a thickness K of, for example, 100 μm.
Therefore, the width of the slit groove 2 is 105 to 110 μm.
m. Therefore, the circular thin blade grindstone 7 having a thickness of 100 μm is used.

Hereinafter, a method of manufacturing the honeycomb structure forming die 1 will be described in detail. First, as shown in FIG. 11A, as the mold material 10, a steel plate made of SKD61 is prepared. The die material 10 is provided with a protruding groove forming surface 11 by cutting in advance. Groove forming surface 11
Is finished in a square shape and is provided so as to protrude from the main body by a thickness T of 2.7 mm.

Next, as shown in FIG.
A shallow hole 40 having a diameter of 1 mm is formed in the groove forming surface 11 of the first groove. This is similar to FIG. 11 (b).
It is provided by drilling from the hole processing surface 14 on the opposite side of the above. The shallow hole 40 is provided so as to be located at a lattice point of the slit groove 2 provided later, and the depth thereof is provided, for example, 1.0 mm shallower than the supply hole 4 to be finally obtained.

Next, as shown in FIG. 3 and FIG. 11 (c), the slit groove 2 is provided on the groove forming surface 11. In forming each slit groove 2, as shown in FIG. 12 described above, the groove forming surface 1 of the die material 10 set on the work table.
1 is brought into contact with the circular thin blade grindstone 7 while rotating, and is moved in the slit groove forming direction.

The contact depth of the circular thin blade grindstone 7 was adjusted so that the groove depth was about 2.4 mm. Therefore, after the formation of the slit groove 2, the slit groove 2 and the shallow hole 40 are provided independently of each other without communication as shown in FIG. Therefore, the slit groove 2 is formed by the shallow hole 4
It is provided linearly without being affected by the presence of 0 and meandering. Further, as shown in FIG. 11C, the slit grooves 2 are sequentially formed in the directions of arrows A and B with respect to the groove forming surface 11 to form a lattice shape.

Next, as shown in FIG. 1, the tip of the shallow hole 40 was subjected to electrolytic processing as non-contact processing. Specifically, first, as shown in FIG. 1, a pipe electrode 61 having a smaller diameter than the shallow hole 40 is prepared. The pipe electrode 61 is formed by coating a tungsten pipe with Teflon, and has an inner hole through which an electrolyte solution 59 is jetted.

Next, the pipe electrode 61 is inserted into the shallow hole 40. At this time, a certain distance is provided between the tip 611 of the pipe electrode 61 and the tip 401 of the shallow hole 40. Next, a voltage is applied between the pipe electrode 61 and the mold material 10, and the electrolytic solution 69 is blown out from the pipe electrode 61 toward the tip 401 of the shallow hole 40. As a result, shallow hole 4
0 is gradually dissolved and removed at the leading end 401. The position of the tip portion 401 gradually advances. Further, the pipe electrode 61 is gradually advanced as the dissolution of the tip portion 401 of the shallow hole 40 progresses.

The electrolytic solution 69 used at this time was Na
Since a Cl aqueous solution (which may be replaced with an NaNO ₃ aqueous solution) is used, the reaction with the mold material 10 is performed as follows. ^{(Positive): Fe → Fe 2+ + 2e} - 2H 2 O → O 2 + 4H + + 4e - ( ^{_{negative): O 2 + 4H + +}} 4e - → 2H 2 O 2H 2 O + 2e - → H 2 + 2OH -

Then, as shown in FIG. 1, when the position of the tip of the shallow hole 40 moves from S to F, the electrolytic processing is terminated. Thereby, the shallow holes 40 are finished into the supply holes 4 in a state of being sufficiently communicated with the slit grooves 2. In addition, the communicating portion between the supply hole 4 and the slit groove 2 can be finished in a healthy state without dripping or burrs. Therefore, according to the present embodiment, by providing the above-described electrolytic processing after providing the shallow hole 40 and the slit groove 2, the meandering of the slit groove is maintained while maintaining the soundness of the communicating portion between the supply hole and the slit groove. Can be reliably prevented.

The processing order of the shallow hole 40 and the slit groove 2 described above may be switched, and the processing of the slit groove 2 may be performed first. That is, as shown in FIG. 4, first, the slit grooves 2 may be provided in a lattice shape in the mold material in the same manner as in the first embodiment, and then the shallow holes 40 may be provided. Also in this case, as shown in FIG. 3, the shallow hole 40 and the slit groove 2 are formed in a non-penetrating state, and the supply hole 4 can be completed by the subsequent non-contact processing. Therefore, also in this case, the same operation and effect as described above can be obtained.

In the above embodiment, the shallow hole 4
0 and the slit groove 2 were provided so as not to overlap at all. However, it is not necessary to limit to this.
If there is no sagging or burrs, a shallow hole 40
The slit groove 2 and the slit groove 2 may be provided with some overlap. Specifically, no problem occurs if the overlap is about 0.2 mm or less.

In the above embodiment, the present invention is applied to a method for manufacturing a honeycomb structure forming die, but a die for forming a general ceramic or resin molded product. The present invention can be similarly applied to the case of manufacturing.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing non-contact processing in an embodiment.

FIG. 2 is a perspective view showing a state where a shallow hole is provided in the embodiment.

FIG. 3 is an explanatory diagram showing a state in which a slit groove is provided in the embodiment.

FIG. 4 is an explanatory diagram showing an example in which a slit groove is provided first in the embodiment.

FIG. 5 is a plan view of a mold in the embodiment.

FIG. 6 is a front view of a mold in the embodiment.

FIG. 7 is an enlarged view of a portion D on the extrusion surface of the mold in FIG.

FIG. 8 is a sectional view taken along line CC of FIG. 7;

FIG. 9 is a perspective view of a honeycomb structure in the embodiment.

FIG. 10 is an enlarged view of a portion M in FIG. 9;

FIG. 11 is an explanatory view showing a mold manufacturing process in a conventional example.

FIG. 12 is an explanatory view showing a slit groove forming method in a conventional example.

[Explanation of symbols]

 1. . . Mold, 10. . . Mold material, 11. . . 1. groove forming surface; . . 3. slit groove; . . Supply hole, 40. . . Shallow hole, 401. . . Tip, 61. . . Pipe electrode, 69. . . Electrolyte,

Continued on the front page (72) Inventor Kunihiro Kodama 1-1-1, Showa-cho, Kariya-shi, Aichi Pref.

Claims (4)

[Claims] In a method of manufacturing a mold having a supply hole for supplying a material and a slit groove provided in communication with the supply hole, a groove forming surface for forming the slit groove and the supply hole are formed. A mold material having a hole processing surface to be provided on the front and back is prepared, the slit material is provided in the mold material, a shallow hole shorter than the supply hole is provided, and then the tip of the shallow hole is removed. A method for manufacturing a mold, wherein the supply hole is formed by elongating the shallow hole by performing non-contact processing. 2. The non-contact processing according to claim 1, wherein
A method for manufacturing a metal mold, which is performed by any one of electrolytic machining, electric discharge machining, and laser machining. 3. The method according to claim 1, wherein the length of the shallow hole is shorter by 0.05 to 2.0 mm than the length of the supply hole. 4. The method according to claim 1, wherein:
The mold is a honeycomb structure forming mold having a supply hole for material supply and a slit groove provided in a lattice shape in communication with the supply hole for forming a material into a honeycomb shape. Characteristic mold manufacturing method.