JPH0625885A - Porous electroformed die and its production - Google Patents

Abstract

PURPOSE:To surely suck a sheet material and to assure the uniformly reversal characteristic of formed parts with the die by communicating the many vent holes formed in the die by meshlike communicating holes crossing the vent holes. CONSTITUTION:A first electrocast layer 2 having the vent holes of a prescribed diameter are formed on an electrocasting master 15 while gases are discharged from the gas discharge ports of the electrocasting master 15. A meshlike member 25 is mounted on this first electrocast layer 2 and a second electrocast layer 3 having the vent holes 6 is formed by executing electrocasting while discharging the gases from the discharge ports of the electrocasting master 15. A second meshlike member 28 is mounted on this second electrocast layer 3 and similarly a third electrocast layer 4 is formed. The two meshlike members 25, 28 are so disposed that the meshes deviate from each other. The resulted die 1 is heated and the meshlike members 25, 28 held by the respective electrocast layers 2, 3, 4, are removed, by which the two meshlike communicating holes 9, 10 crossing the vent holes 6 are formed. As a result, the porous electroformed die 1 having the desired forming surface is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porous electroforming mold used for vacuum forming, hollow forming and the like of plastics and a method for producing the same, and in particular, by reliably sucking a sheet material from all vent holes. The present invention relates to a molded product that can be uniformly inverted with respect to a molding die.

[0002]

2. Description of the Related Art First, the structure of a porous electroforming mold of this type and an example of its use will be described with reference to FIG. In FIG. 8, the porous electroformed mold 31 has a large number of ventilation holes 31a, and includes a vacuum pump 32, a heater 33, and a clamp 3.
In the vacuum forming machine 35 in which 4 is arranged, the forming surface 31b on which a grain pattern or the like is formed is provided as an upper side. When vacuum-molding a door trim outer skin, a crash pad outer skin, etc. of an automobile interior part using this porous electroforming mold 31, first, the sheet material 36 is heated and softened by the heater 33 to form the sheet material 36. The clamp 34 is fixed above the mold 31. Then, by operating the vacuum pump 32, the air between the sheet material 36 and the molding die 31 is sucked through the ventilation hole 31 a, and the space between the sheet material 36 and the molding die 31 is brought into a vacuum state. Then, the sheet material 36 is attracted to the molding die 31 to bring the sheet material 36 into close contact with the molding surface 31 b of the molding die 31, and the sheet material 36 is molded into the same shape as the molding die 31.

By the way, in order to obtain a dense reversibility such as a textured pattern, it is desirable that a large number of small vent holes 31a of the molding die 31 are opened, and the size thereof is 0.
It is preferably about 1 mm, but it is not realistic to form such a small vent hole 31a by machining or electric discharge machining. Therefore, conventionally, a porous electroformed mold is manufactured by the following manufacturing method.

In FIG. 9, this manufacturing method is shown in FIG.
As shown in (a), an electroformed master 41 having the same shape as the molded product is manufactured, and a conductive layer 42 is attached to the surface 41a of the electroformed master 41 by a silver film by silver mirror treatment. Then, as shown in FIG. 9B, a large number of holes 42 a are formed in the conductive layer 42 by applying a silver corrosive agent on the conductive layer 42.
To provide. Then, as shown in FIG.
3, the electroformed master 41 is subjected to electroforming to deposit a metal such as nickel or copper on the conductive layer 42 excluding the holes 42a on the surface of the electroformed master 41, and a porous electrode having a large number of vent holes 31a. This is a method for producing the casting mold 31 (see Japanese Patent Laid-Open No. 61-253392). As described above, the conventional manufacturing method is a method in which a large number of non-conductive portions are provided in the conductive layer on the surface of the electroformed master to form a large number of ventilation holes in the molding die.

[0005]

In the method of manufacturing the porous electroforming mold described in the prior art, the metal is not deposited on the non-conductive portion such as the many holes 42a provided in the conductive layer 42. Although the vent hole 31a is formed in this manner, electrons are likely to concentrate in the corner portion of the hole portion 42a on the electrolyte solution 43 side, and more metal tends to deposit in the corner portion. For this reason, as the thickness of the deposited metal increases, the vent holes 31a formed on the hole portions 42a gradually become thin like a conical shape, and some vent holes 31a may be blocked without being formed, In particular, as the thickness of the mold becomes thicker, many of them are clogged, and depending on the shape of the molding die 31, some portions may not be sufficiently sucked during molding. As a result, the sheet material 36 at the time of molding
However, there is a problem in that the molded product has insufficient adhesion to the molding die 31 and a portion having a low reversal rate with respect to the molding die 31 is formed, so that a molded product of uniform quality cannot be secured.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to surely suck the sheet material from all the vent holes to form a molded article. It is an object of the present invention to provide a porous electroformed mold capable of achieving uniform reversal with respect to the mold and a method for manufacturing the same.

[0007]

In order to solve the above-mentioned problems, a porous electroforming mold of the present invention is a porous electroforming mold having a large number of vent holes penetrating the mold. The mesh-like communication holes are provided so as to substantially communicate with each other across the ventilation holes.

This porous electroforming mold comprises a step of forming a first electroformed layer having a large number of first vent holes by electroforming; a combustible mesh member is provided on the first electroformed layer. One or more steps of attaching and forming a second electroformed layer having a second vent hole communicating with the first vent hole on the first electroformed layer and the mesh member by electroforming; each electroformed layer; It can also be manufactured by including a step of heating and removing the mesh member sandwiched between.

[0009]

[Function] Since the respective vent holes are substantially communicated with each other by the mesh-like communicating holes that traverse the vent holes, even if there are vent holes that are blocked in the process of forming the electroformed layer, at the time of molding, Exhaust is ensured through the adjacent vents.

The mesh-like communication holes are formed by heating and removing the mesh-like member sandwiched between the electroformed layers.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a porous electroforming mold of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIGS. 3 to 7 are views showing a method of manufacturing a porous electroforming mold of the present invention. Is.
Note that the use example of the porous electroforming mold is the same as that described with reference to FIG.

1 and 2, the porous electroformed mold 1 comprises a first electroformed layer 2, a second electroformed layer 3 formed by depositing a metal such as nickel or copper by electroforming. It is composed of the third electroformed layer 4 and has a molding surface 5 on which a grain pattern or the like is formed. Further, the porous electroformed mold 1 has a large number of minute air holes 6 penetrating through the mold, and the first mesh-like communication formed in the mold in a direction traversing the large number of air holes 6. A hole 9 and a second mesh communication hole 10 are provided. The first mesh-like communication holes 9 and the second mesh-like communication holes 10 are arranged such that the meshes are zuri in plan view,
At least one of the first mesh-like communication hole 9 and the second mesh-like communication hole 10 crosses each of the ventilation holes 6, so that a large number of the ventilation holes 6 and the first mesh-like communication hole 9 and the first mesh-like communication hole 9 are formed. It is in a substantially communicating state via the second mesh-like communicating hole 10.

Next, a method of manufacturing the above-mentioned porous electroforming mold will be described with reference to FIGS. Figure 3
As shown in (a), an electroformed master 15 (reverse model of a porous electroformed mold) having the same shape as the molded product is manufactured, and a hollow portion 15b having a suction port 15a on the bottom side of the electroformed master 15 is manufactured. To provide. The electrocast master 15 has a discharge hole 1 with a minute diameter which is opened on the surface 15c of the electrocast master 15.
A porous material having a large number of 5d and in which the cavity 15b and the surface 15c communicate with each other is used. The porous electroformed master 15 is formed by a known method such as using a breathable material such as ceramic. It is possible to obtain.
Then, as shown in FIG. 3B, a conductive layer 16 is provided on the surface 15c of the electroformed master 15 by using a silver film or the like by silver mirror treatment except for the portion of the discharge hole 15d.

Then, as shown in FIG. 4, the electrocast master 15 is prepared by using an electrolytic solution 20 (nickel sulfamate, copper sulfate, etc.) in an electrocasting tank 19 in which a metal 18 such as nickel or copper is connected to a positive electrode. Immerse in. Then, a gas such as nitrogen is supplied from the gas supply device 23 to the hollow portion 15 of the electroforming master 15.
Then, the gas is discharged into b and the gas is discharged from the discharge hole 15d formed in the surface 15c of the electroforming master 15. Then, the electroconductive layer 16 is connected to the negative electrode to be energized, and the electroforming master 15 is electroformed. As a result, a metal such as nickel or copper is deposited on the conductive layer 16 on the surface of the electroformed master 15, and the first electroformed layer 2 is formed.
Since gas is constantly discharged from d, the discharge hole 1
The metal is less likely to be deposited on the corner portion of 5d, and the first electroformed layer 2 increases in thickness while forming the vent hole 6 having a predetermined diameter.

When the first electroformed layer 2 has a predetermined thickness, the electroformed master 15 is taken out of the electrolytic solution 20.
As shown in (a) and FIG. 5 (b) (viewed from the arrow B in FIG. 5 (a)), the first electroformed layer 2 is made of glass fiber or the like having gas permeability, conductivity, and flammability. The mesh member 25 is attached.

Further, as shown in FIG. 6, the first electroformed layer 2
The electroformed master 15 having the mesh member 25 attached thereon is dipped in the electrolytic solution 20, and the discharge hole 1 of the electroformed master 15 is immersed.
The electroforming master 15 is subjected to electroforming while discharging gas from 5d. As a result, the metal is deposited on the first electroformed layer 2 and the first mesh member 25 to form the second electroformed layer 3, but the gas is constantly exhaled from the expulsion hole 15d. The electroformed layer 3 increases in thickness while forming the vent hole 6 having a predetermined diameter. The first electroformed layer 2
In the case where the first mesh member 25 covers the vent hole 6 formed in, the first mesh member 25 has air permeability, and gas is discharged through the first mesh member 25. The ventilation holes 6 are also formed on the first mesh member 25.

When the second electroformed layer 3 has a predetermined thickness, the electroformed master 15 is taken out of the electrolytic solution 20. Then, in the same manner as described with reference to FIGS. 5 and 6, the second mesh member 28 is attached onto the second electroformed layer 3 to form the electroformed master 1.
5 is immersed in the electrolytic solution 20, and the electroforming master 15 is subjected to electroforming while discharging gas from the discharge hole 15d of the electroforming master 15 to form a second layer on the second electroformed layer 3 and the second mesh member 28. The three electroformed layer 4 is formed. At this time, at least one of the first mesh member 25 and the second mesh member 28 is disposed by arranging the second mesh member 28 so that the mesh is offset from the first mesh member 25 in plan view. Each vent hole 6 is crossed. As described above, when the electroforming process is performed while discharging the gas, the gas is discharged through the mesh members 25 and 28 having gas permeability, and the vent hole 6 can maintain the communication state. It is possible to prevent more metal from being deposited on the corner portion of the vent hole 6 and clogging the vent hole 6 due to the discharge of
A porous electroformed mold having a large thickness can be obtained.

When the third electroformed layer 4 has a predetermined thickness, the electroformed master 15 is taken out of the electrolytic solution 20,
As shown in (a), the molding die 1 is removed from the electroforming master 15. Then, as shown in FIG.
Is heated in an oven 29 to remove the mesh members 25 and 28 sandwiched between the electroformed layers 2, 3 and 4, so that the first mesh communication hole 9 and the second mesh shape that cross the ventilation hole 6 are formed. The communication hole 10 is formed. As a result, the porous electroformed mold 1 having the molding surface 5 formed in a desired shape and having a large number of minute ventilation holes 6 and the mesh-shaped communication holes 9 and 10 is manufactured. As described above, each of the ventilation holes 6 is configured to cross at least one of the first mesh-shaped communication hole 9 and the second mesh-shaped communication hole 10, and is substantially communicated. Therefore, even if there is a vent hole that is blocked in the process of forming the electroformed layer, the exhaust is surely performed through the adjacent vent hole at the time of molding. As a result, at the time of molding, the sheet material is sucked from all the vent holes, and the sheet material is evenly adhered to the molding die, so that it is possible to ensure uniform reversal of the molded product with respect to the molding die. become able to.

In the above embodiment, the vent hole is formed by discharging the gas, but the method of forming the vent hole is not limited to this. For example, a silver corrosive agent is applied on the conductive layer. Form a vent hole in the first electroformed layer by making the conductive layer porous by attaching,
By the same process, a mesh member having a porous non-conductive portion can be attached to the first electroformed layer to form a ventilation hole on the mesh member. Further, in the above-mentioned embodiment, the case where the mesh-like communicating hole has two layers has been described, but it is of course possible to have one layer or three or more layers.

[0020]

Since the present invention is configured as described above, it has the following effects. Since each ventilation hole is substantially connected by a mesh-shaped communication hole that traverses the ventilation hole, even if there is a ventilation hole blocked during the process of forming the electroformed layer, the ventilation holes that are close to each other at the time of molding Exhaust is surely made through. As a result, at the time of molding, the sheet material is sucked from all the vent holes, and the sheet material is evenly adhered to the molding die, so that it is possible to ensure uniform reversal of the molded product with respect to the molding die. become able to.

Since the mesh-like communication holes are formed by heating and removing the mesh-like members sandwiched between the electroformed layers, a porous electroformed hole having a desired mesh-like communication hole can be formed by a simple process. A mold can be manufactured.

[Brief description of drawings]

FIG. 1 is a sectional view of a porous electroforming mold of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a view showing a method for manufacturing a porous electroforming mold of the present invention.

FIG. 4 is a diagram showing a method for manufacturing a porous electroforming mold of the present invention.

FIG. 5 is a diagram showing a method for manufacturing a porous electroforming mold of the present invention.

FIG. 6 is a diagram showing a method for manufacturing a porous electroforming mold of the present invention.

FIG. 7 is a diagram showing a method for manufacturing a porous electroforming mold of the present invention.

FIG. 8 is a cross-sectional view of a conventional porous electroforming mold.

FIG. 9 is a view showing a method for manufacturing a conventional porous electroforming mold.

[Explanation of symbols]

 2 1st electroformed layer 3 2nd electroformed layer 4 3rd electroformed layer 6 Vent hole 9 1st mesh communication hole 10 2nd mesh communication hole 11 Electroformed layer 15 Electroformed master 25 1st mesh member 28 Second mesh member

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Claims (2)

[Claims] 1. A porous electroformed mold having a large number of vent holes penetrating through the mold, wherein a mesh-like communication hole is provided in the mold so as to communicate substantially across the plurality of vent holes. Porous electroforming mold. 2. A step of forming a first electroformed layer having a large number of first vent holes by electroforming; a flammable mesh member being attached to the first electroformed layer, and a first electroformed layer being formed by electroforming. One or more steps of forming a second electroformed layer having a second vent hole communicating with the first vent hole on the electroformed layer and the mesh member; and heating the mesh member sandwiched between the electroformed layers. The method for producing a porous electroformed mold according to claim 1, further comprising a step of removing.