JPH07116631B2 - Electroforming mold and method for manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroforming mold used for injection molding, blow molding and the like of plastics and a method for manufacturing the same, and in particular, to secure a predetermined electrodeposition thickness over the entire electroformed shell. , Those that can prevent mold breakage.

[0002]

2. Description of the Related Art Conventionally, as an electroforming mold of this type, FIG.
There is one shown in. In FIG. 6, this electroforming mold is
An electroformed shell 51 formed by depositing a metal such as nickel or copper to a predetermined thickness by electroforming is reinforced by backing it with a backing material 52 of thermosetting resin or low melting point alloy. A stainless pipe 53, which serves as a flow path for heating / cooling fluid, is provided inside 52. The stainless steel pipe 53 is running in the mold, and a heating / cooling fluid is circulated in the stainless steel pipe 53 to allow the electroformed shell 5 to flow.
By performing heat exchange with the electroformed shell 51 and heating and cooling the electroformed shell 51, the molding surface 51a of the electroformed shell 51
It is adapted to mold the injected plastic material. Reference numeral 55 denotes a mold, and although the figure shows the cavity in the electroforming mold, the core has the same structure.

[0003]

In the electroforming shell 51 of the electroforming mold described in the prior art, the electroforming master manufactured in the same shape as the molded product is dipped in the electrolytic solution to form the surface of the electroforming master. It is formed by depositing a metal such as nickel or copper. In the process of forming the electroformed shell 51 by this electroforming, the flow of the electrolytic solution becomes worse in the downwardly convex dented portion on the metal deposition surface. Therefore, the metal is not sufficiently deposited, and the electrodeposition thickness becomes thin, and there is a risk of die damage from this portion. For this reason, by providing an auxiliary electrode in the vicinity of the downward convex depression portion on the metal deposition surface, the metal deposition rate in this portion can be increased to increase the metal deposition amount. Even if the auxiliary electrode is provided, there is a problem that a sufficient electrodeposition thickness cannot be secured.

The present invention has been made in view of the above problems of the prior art. The object of the present invention is to secure a predetermined electrodeposition thickness over the entire electroformed shell, It is intended to provide an electroformed mold capable of preventing mold breakage and a method for manufacturing the same.

[0005]

In order to solve the above-mentioned problems, an electroforming mold of the present invention is an electroforming mold having an electroforming shell formed by electroforming. A mesh member is integrally included in a part or all of one or more downward convex depressions on the opposite side of the surface.

Further, this electroforming mold has a step of forming a first electroformed layer by electroforming, and one of one or more concave depressions on the metal deposition surface of the first electroformed layer. Manufactured including a step of temporarily fixing the mesh member to a part or the whole and a step of forming an electroformed shell to form a first electroformed layer and a second electroformed layer on the mesh member to produce an electroformed shell. You can also do it.

[0007]

In the selective portion of the concave portion which is convex downward on the metal deposition surface of the first electroformed layer, the space between the mesh member temporarily fixed to this portion and the first electroformed layer is filled. Since the second electroformed layer is formed in this manner, the mesh member is integrally included in the first electroformed layer and the second electroformed layer, and the thickness is increased by the thickness of the mesh member. .

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an electroforming mold of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIGS. 3 to 5 are views showing a method of manufacturing the electroforming mold of the present invention.

1 and 2, the electroforming mold has a first electroformed layer 2 formed by depositing a metal such as nickel or copper by electroforming, and a back surface 2a of the first electroformed layer 2. A mesh-like member 3 of a wire mesh made of nickel, copper, or the like, which is arranged in a downward convex concave portion 2c on the side opposite to the molding surface 2b, and a back surface 2a of the first electroformed layer 2 formed by electroforming and a mesh-like shape. A backing material 5 made of a thermosetting resin such as an epoxy resin or a low melting point alloy such as an alloy of tin and bismuth or an alloy of tin and zinc is used as an electroformed shell 1 including a second electroformed layer 4 that covers the member 3.
The backing material 5 is internally reinforced with a stainless pipe 6 serving as a flow path for heating / cooling fluid. It should be noted that the actual shape of the electroformed mold used for molding automobile interior parts and the like is complicated, and the electroformed shell 1 has a concave portion 2c which is a downward convex portion on the opposite side of the molding surface 2b.
Among them, the mesh member 3 is arranged by selecting a portion that becomes a weak point in terms of strength among them. 7 is a formwork.

Next, a method for manufacturing the above-mentioned electroforming mold will be described with reference to FIGS. As shown in FIG. 3A, an electroformed master 11 having the same shape as the molded product made of epoxy resin, polyester resin, or the like (inverse model of the electroformed mold).
Then, the conductive layer 12 is attached to the surface of the electroformed master 11 by a silver film or the like by silver mirror treatment. And FIG.
As shown in (b), the electroforming master 11 is provided with an electroforming tank 14 in which a metal 13 such as nickel or copper is connected to a positive electrode.
Immerse in the electrolytic solution 15 of. Then, the conductive layer 12 is connected to the negative electrode and electricity is applied, and the electroformed master 11 is connected to the electrolytic solution 1
The electroforming master 11 is subjected to electroforming while being moved laterally in 5. Thereby, the conductive layer 1 on the surface of the electroformed master 11
Metals such as nickel and copper are deposited on the second electroformed layer 2
However, in the recessed portion 2c that is convex downward on the metal deposition surface, it is difficult for the metal to deposit due to the poor flow of the electrolytic solution 15, and the electrodeposition thickness becomes thin. Then, the electroformed master 11 is taken out of the electrolytic solution 15 when the portion except for the convex recessed portion 2 c below the first electroformed layer 2 has a predetermined electrodeposition thickness.

4 (a) and 4 (b) (FIG. 4)
As shown in (a) arrow B view), on a selective portion of the concave portion 2c convex below the first electroformed layer 2 formed on the surface of the electroformed master 11, this portion is formed. The mesh-like member 3 made of a conductive wire mesh of nickel, copper, or the like, which is processed so as to conform to it, is temporarily fixed with an adhesive or the like. Then, as shown in FIG. 4 (c), the electrocasting master 11 is replaced with the electrolytic solution 15 in the electrocasting tank 14.
It is dipped in the inside again, and the electroforming master 11 is electroformed. Thereby, the first electroformed layer 2 on the surface of the electroformed master 11
The metal is deposited on the mesh member 3 to form the second electroformed layer 4. At this time, in the selective portion of the concave portion 2c convex below the first electroformed layer 2, the amount of metal deposited is small because the flow of the electrolytic solution 15 is poor, but the mesh member 3 is present.
Since the second electroformed layer 4 is formed so as to fill the space between the first electroformed layer 2 and the first electroformed layer 2, the mesh member 3 is integrated in the first electroformed layer 2 and the second electroformed layer 4. Therefore, the thickness of the mesh member 3 is increased by the thickness of the mesh member 3.
An electroformed layer having a substantially uniform thickness is formed on the entire surface. Then, when the electroformed layer on the electroformed master 11 has a predetermined electrodeposition thickness, the electroformed master 11 is taken out of the electrolytic solution 15.

Further, as shown in FIG. 5 (a), the back surface side of the second electroformed layer 4 is surrounded by a mold 7, and a stainless pipe 6 serving as a flow path for heating / cooling fluid is arranged. Then, a backing material 5 of a thermosetting resin such as an epoxy resin or a low-melting point alloy such as an alloy of tin and bismuth or an alloy of tin and zinc is poured into the mold 7 and the backing material 5 is changed with time. Let it solidify. Then, as shown in FIG. 5B, the electroformed master 11 is extracted from the first electroformed layer 2. As a result, the electroformed shell 1 integrally including the mesh member 3 in the first electroformed layer 2 and the second electroformed layer 4 is lined with the backing material 5 and reinforced, and the flow of the heating / cooling fluid is performed. An electroforming mold having a stainless pipe 6 serving as a passage is manufactured. Although the drawing shows the cavity in the electroforming mold, the core can have the same configuration and can be manufactured by the same manufacturing method.

As described above, in the selective portion of the downward convex depression portion 2c on the metal deposition surface of the first electroformed layer 2,
The amount of metal deposited is small because the flow of the electrolytic solution 15 is poor, but the space between the mesh member 3 and the first electroformed layer 2 temporarily fixed to this portion is filled so as to fill the second electroformed layer. Since the layer 4 is formed, the mesh member 3 is integrally contained in the first electroformed layer 2 and the second electroformed layer 4, and the mesh member 3 is formed.
The thickness increases by the thickness of. As a result, the electroformed shell 1 can secure a predetermined electrodeposition thickness over the whole, and it is possible to prevent mold breakage due to a locally thin electrodeposition portion. Become. Therefore, it is possible to manufacture by electroforming, also a molding die having an electroformed shell having a portion where metal is not likely to be deposited structurally during electroforming. Further, in the portion where the mesh member 3 is provided, the boundary surface of the electroformed shell 1 with the backing material 5 becomes uneven, and the backing material 5 is filled in the recessed portion to exert an anchoring effect. This prevents the electroformed shell 1 and the backing material 5 from peeling off.

In the above embodiment, the description was made of the case where only one layer of the mesh-like member was provided in the downward convex depression portion on the metal deposition surface of the first electroformed layer, but it should be two or more layers. Also, in the case where there are a plurality of downward convex depressions, it is possible to select the number of layers of the mesh member according to each shape. Furthermore, in the above-mentioned example, the case where the step of temporarily fixing the mesh member and forming a new electroformed layer on the electroformed layer formed on the surface of the electroformed master was performed only one step was described. It is naturally possible to have two or more steps.

[0015]

Since the present invention is configured as described above, it has the following effects. In the selective portion of the concave portion that is convex downward on the metal deposition surface of the first electroformed layer, the amount of metal deposition is small because the flow of the electrolyte is poor, but it was temporarily fixed to this portion. Since the second electroformed layer is formed so as to fill the space between the mesh member and the first electroformed layer, the mesh member is integrally included in the first electroformed layer and the second electroformed layer. As a result, the thickness is increased by the thickness of the mesh member. As a result, it becomes possible to secure a predetermined electrodeposition thickness over the entire electroformed shell, and it becomes possible to prevent mold breakage due to a locally thin electrodeposited portion. .

[Brief description of drawings]

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

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

FIG. 3 is a diagram showing a method for manufacturing an electroforming mold of the present invention.

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

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

FIG. 6 is a cross-sectional view of a conventional electroforming mold.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Electroformed shell 2 1st electroformed layer 2b Electroformed shell molding surface 2c Downward convex depression part on the opposite side of electroformed shell molding surface (downward convex depression in metal deposition surface of 1st electroformed layer) Part) 3 mesh member 4 second electroformed layer 5 backing material 11 electroformed master

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sekiharu Nagata 35, 4-4 Ise-machi, Hekinan-shi, Aichi (56) Reference JP-A-63-243293 (JP, A)

Claims (2)

[Claims] 1. An electroforming mold having an electroformed shell formed by electroforming, wherein the electroformed shell is a part or all of one or more downward convex depressions on the opposite side of the forming surface. An electroforming mold characterized in that a mesh member is integrally included in the. 2. A step of forming a first electroformed layer by electroforming, and a mesh member in a part or all of one or more downward convex depressions on the metal deposition surface of the first electroformed layer. The electroforming according to claim 1, further comprising a step of temporarily fixing the electroformed shell and a step of forming a second electroformed layer on the first electroformed layer and the mesh member by electroforming to produce an electroformed shell. Mold manufacturing method.