JPH0151552B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an electroforming mold and a method for manufacturing the same, particularly,
The present invention relates to an electroforming mold that can be formed with ultra-high precision in a short time, and a method for manufacturing the same.

(Prior Art) Electroforming is a method for forming a male part or a female part of a plastic mold. Electroforming can produce molds with ultra-high precision mold surfaces compared to machining methods for metal materials or metal casting methods. However, the electroforming method has a fatal drawback in that it takes too much time to manufacture the mold. For example, it takes about 3 to 4 weeks to form a 5 mm thick metal layer. Moreover,
When an electroformed layer is formed on a metal master mold (mother mold), the convex portions on the surface of the master mold have a more significant current collecting effect than the concave portions, so that the electroformed metal is excessively deposited on the convex portions. Since the current collecting effect of the excessively deposited portion is further increased, the uniformity of electrodeposition becomes worse. Therefore, depending on the shape, it is necessary to take out the mother mold from the bath during the electroforming process, cut off the protrusions formed by excessive precipitation by machining, and then perform electroforming again. Adopting such an electroforming process requires too long a period of time, so as shown in FIG. After fitting the iron block 102 which has been appropriately processed into the deposited part, a plating layer 103 is again formed around it. However, even in the above method, it takes a long time to form a desired electroformed layer on the matrix. In order to solve the above-mentioned drawbacks, there is a method of electroforming a mother mold to a suitable thickness and then casting a zinc alloy or the like as a backing material thereon. However, although this method looks like a mold body, the electroformed metal layer and the cast alloy layer do not adhere tightly, so both layers peel off during use, and eventually It will get damaged. Furthermore, the die is deformed due to solidification shrinkage of the casting alloy, and sometimes it becomes impossible to separate the mother mold and the electroforming mold due to the shrinkage of the casting alloy. As a result, precise molds cannot be manufactured.

On the other hand, as a method of obtaining a complex-shaped mold with extremely high precision, there is a method in which the male or female part of the mold has a block structure. In this case, it is necessary to assemble each block mold with high precision without creating a pattern gap between adjacent block molds. A reinforcing frame made of, for example, steel is attached around each block mold, and the abutting surfaces of this reinforcing frame are finished with extremely high precision. However, the reinforcing frame is only bonded to the bucking cast alloy and is not tightly bonded to the electroformed metal layer. Therefore, under continuous load, the two gradually separate, making it impossible to maintain a stable equilibrium state of the mold surfaces between the respective mold cavity parts for a long period of time. Therefore, a molded product having a desired shape cannot be obtained by integral molding. Molten resin infiltrates into the minute gap created between the reinforcing frame and the electroformed metal layer, causing poor dimensional accuracy and burrs in the molded product. Electron beam welding and laser welding methods are used to bond the reinforcing frame and the electroformed metal layer, but with either method, the mold may be thermally deformed or the welded area may become constricted, making it difficult to use ultra-high precision molds. I can't provide it. Although there is a method of connecting the two using a dowel pin or the like, the work is complicated and increases the manufacturing process.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems, and its purpose is to provide an electroforming mold that can form an ultra-high precision cavity part and a method for manufacturing the same. It is about providing. Another object of the present invention is to provide an electroforming mold that can be obtained in an extremely short time and at low cost, and a method for manufacturing the same. Still another object of the present invention is to provide an electroforming mold with a block structure that allows each block mold to be assembled with high precision without creating a gap between adjacent block molds, and a method for manufacturing the same.

(Means for solving the problems) The present invention provides a backing material for an electroformed metal layer.
For example, by using a metal member made of iron, iron alloy, copper, or copper alloy, and firmly adhering the metal member and the electroformed metal layer via a plating metal layer, the electroforming mold can be formed quickly and easily. This was completed based on the inventor's knowledge that it can be obtained at low cost.

Therefore, the electroforming mold of the present invention includes an electroformed metal layer constituting a cavity portion of the mold, and a backing metal member located on the back side of the electroformed metal layer, and the electroformed metal layer The electroformed metal layer and the backing metal member are joined by a first plating metal layer formed in a band-shaped notch provided along the outer periphery of the boundary area between the electroformed metal layer and the backing metal member, and The above objective is achieved. The method for manufacturing this mold also includes (1) forming an electroformed metal layer on the outer surface of a metal mother mold, including the mold surface of the cavity portion; (2) forming an electroformed metal layer along the outer peripheral edge of the electroformed metal layer. (3) arranging a backing metal member on the back side of the electroformed metal layer and forming a band-shaped space along the outer periphery of the boundary area between the two, and (4) the band-shaped space. The above object is achieved by forming a first plating metal layer and bonding the electroformed metal layer and the backing metal member.

The electroformed metal layer may be made of, for example, copper, iron, nickel,
It is composed of at least one member selected from the group consisting of nickel-cobalt alloy, nickel-iron alloy, and nickel-phosphorus alloy. The metal layer thickness is
There are no particular restrictions, but it depends on workability and usage conditions of the finished mold. Usually, it is set in the range of 0.2 mm to 5 mm.

The metal member for backing is not particularly limited as long as it fulfills the mold reinforcing function as backing (lining). A material with excellent machinability is preferably used. For example, it is composed of at least one member selected from the group consisting of iron, iron alloys, copper, and copper alloys.

The first plating metal layer may be made of, for example, copper, iron,
Nickel, Nickel-cobalt alloy, Nickel-
It is composed of at least one member selected from the group consisting of iron alloys and nickel-phosphorus alloys. This metal layer functions as an adhesive for bonding the electroformed metal layer and the backing metal member. There are no particular restrictions on the form of adhesion using this plating metal layer, but from the viewpoint of workability, for example, a band-shaped notch provided along the outer periphery of the boundary area between the electroformed metal layer and the backing metal member. This is done by applying metal plating. The width, depth, etc. of the band-shaped cutout are appropriately set depending on the usage conditions of the mold.

It is also possible to cast a casting alloy inside the bucking metal member. In this case, intermediate processing of the electroformed metal layer formed on the mother mold becomes unnecessary, and the working process is further shortened. It goes without saying that the smaller the casting shrinkage of this casting alloy, the higher the dimensional accuracy and surface precision of the mold cavity. Expandable metals, e.g.
Bismuth or the like may also be used. Examples of such casting alloys include bismuth-tin alloys, bismuth-tin-zinc alloys, bismuth-cadmium alloys, tin-lead-cadmium alloys, tin-cadmium alloys, and tin-lead alloys having a melting point of about 600°C or less. alloy, tin-zinc alloy, tin-silver alloy, tin-copper alloy, tin-copper-antimony alloy, copper-zinc alloy, zinc-aluminum alloy, aluminum-copper alloy, silver solder and gold solder Consists of at least one type. When casting the above-mentioned casting alloy, by simultaneously casting a water cooling and/or heating tube made of copper or the like, it is possible to control the temperature of the mold during molding of the plastic material. In addition, if 20 to 60% by weight of fine metal grains such as iron, which have been plated and have a diameter of about 0.5 to 5 mm, are mixed into the cast alloy, the solidification shrinkage rate of the cast alloy can be suppressed to a very small level. It is possible to improve the compression resistance of the cast alloy. These metal particles can minimize the solidification shrinkage rate of the cast alloy, and there are no particular restrictions on the type of metal.

Even if a second plating metal layer is applied to the joint surfaces of the electroformed metal layer and the backing metal member, and then the two are bonded via the cast alloy layer, the electroformed metal layer and the backing metal member cannot be connected to each other. It can be strongly bonded to. The second plating metal layer is, for example,
Tin, copper, zinc, tin-zinc alloy, tin-lead alloy, tin-
It is composed of at least one member selected from the group consisting of copper alloys and copper-zinc alloys. This metal layer is
There is no particular restriction on the thickness as long as it functions as an adhesive for bonding the electroformed metal layer and the cast alloy layer, and the backing metal member and the cast alloy layer. Usually, it is set in the range of several μm to several tens of μm, for example, 5 μm to 20 μm.

(Example) The present invention will be described below with reference to examples.

Example 1 The electroforming mold of the present invention is, for example, shown in FIGS.
It is manufactured as shown in Figure c. First, copper, iron, nickel, nickel-cobalt alloy, nickel-iron alloy, or nickel-phosphorus alloy is electroformed to a thickness of about 0.2 to 5 mm on a male brass master mold 10, and An electroformed metal layer 11 is formed. As the electrolytic solution for electroforming, an electrolytic solution for metal plating containing a required metal or alloy can be used as appropriate. For example, in the case of nickel, it is nickel sulfamate. Next, the upper part 110 of the electroformed metal layer 11 formed on the mother mold 10 is cut smoothly, and a notch 111 is provided along the outer periphery thereof (FIG. 1a).

Next, a backing metal member 12 made of steel is placed on the cut surface 110 of the electroformed metal layer 11 coaxially with the mother die 10 . At this time, electroformed metal layer 1
1 and the backing metal member 12 are preferably temporarily bonded together using an adhesive or the like. A notch 121 is provided on the outer peripheral edge of the backing metal member 12. The notch 121 of this bucking metal member 12 and the notch 111 of the electroformed metal layer 11 form a band-shaped space with a width of about 4 mm and a depth of about 1 mm. Next, this strip-shaped space is plated with nickel or nickel alloy to an appropriate thickness by electroplating to form a first plated metal layer 13, thereby producing a mold prototype (FIG. 1b).

Next, the mold prototype is cut into a desired shape as required, and the mother mold 10 is released. Electroformed metal layer 11 of the obtained mold and backing metal member 1
2 through the first plating metal layer 13 (FIG. 1c).

The molds manufactured by this method were fabricated block by block to match the shape of a predetermined portion of a desired molded product, and the contact surfaces of each block were ground with ultra-high precision, and then assembled into an injection mold. When the product was integrally molded by injection molding using various thermoplastic materials, it was found that it had sufficient durability without any abnormality even after being used 100,000 times. By firmly adhering the electroformed metal layer 11 and the backing metal member 12 via the first plating metal layer 13, an ultra-high precision mold surface could be maintained for a long period of time. In the obtained integrally molded product, no defects in dimensional accuracy or occurrence of burrs were observed.

Example 2 In Example 1, when joining the electroformed metal layer 11 to the backing metal member 12, as shown in FIG. 2, a second plating metal layer 14 for adhesion was applied to each joint surface, and , a cast alloy layer 15 was interposed between these joint surfaces. Electroformed metal layer 11 and bucking metal part material 1 constituting the obtained mold
2 was further firmly bonded to the second plated metal layer 14 and the cast alloy layer 15 by the adhesive force.

Example 3 In Example 1, as shown in FIG. 3, the bucking metal member 12 was provided only on the outer peripheral surface of the mold and bonded to the electroformed metal layer 11, and then the casting alloy was cast inside it. Electroformed metal layer 1 of the obtained mold
1 and bucking metal member 12 are cast alloy layer 1
6, the bonding was even stronger. Since the electroformed metal layer 11 is not subjected to grinding, the mold manufacturing process can be further shortened.

Example 4 When manufacturing the mold of Example 3, as shown in FIG. 4, a copper tube 17 with an adhesive plating layer on the outer surface was placed as a water cooling hole or a heating hole, and the cast alloy layer 1
6 was formed. When the obtained mold was assembled into an injection mold and the mold temperature was adjusted using the copper tube 17 as a water cooling hole or heating hole, it became possible to shorten the molding time. It was also possible to improve the appearance and dimensional accuracy of the obtained molded product.

Example 5 30% by weight of fine iron particles (diameter 1 to 3 mm) whose surface had been plated for adhesion was mixed into the cast alloy used in Examples 3 and 4, and this was used to form a cast alloy layer. 16, it was possible to suppress the solidification shrinkage rate of the cast alloy to a very small level. Furthermore, the compression resistance of the cast alloy could be improved.

Example 6 At the time of manufacturing the mold of Example 3, as shown in FIG. After this, the casting alloy was cast. Further, a backing metal member 20 having a second plating metal layer 18 for adhesion on its back surface was arranged. The obtained mold has a second plating metal layer 1
8 and the cast alloy layer 19, it was possible to bond even more firmly. Compression resistance has also been improved.

(Effects of the Invention) As described above, in the mold of the present invention, the electroformed metal layer and the backing metal member are firmly connected and fixed by the plating metal layer, and the electroformed metal layer constituting the mold surface is has the characteristic that it has ultra-high dimensional accuracy and that the metal member that backs it can be easily formed in a short period of time. therefore,
The mold of the present invention has extremely high precision and can be manufactured easily and inexpensively. Furthermore, it has excellent compression resistance. Further, the mold of the present invention can be applied to a mold having a block structure, and a molded product having a cavity portion of a complicated shape can be easily obtained with ultra-high precision.

[Brief explanation of drawings]

Figures 1a to 1c are front sectional views showing one embodiment of the mold of the present invention, and Figures 2 to 5 are front sectional views showing other embodiments of the mold of the present invention, respectively. , FIG. 6 is a front sectional view showing an example of a conventional mold. 11... Electroformed metal layer, 12, 20... Metal member for backing, 13... First plating metal layer, 1
4, 18... second plating metal layer, 15, 16,
19...cast alloy layer.

Claims (1)

[Scope of Claims] 1. An electroformed metal layer constituting a cavity portion of a mold, and a backing metal member located on the back side of the electroformed metal layer, wherein the electroformed metal layer and the backing metal An electroforming mold in which the electroformed metal layer and the backing metal member are joined by a first plating metal layer formed in a band-shaped notch provided along the outer circumference of a boundary area with the member. 2. The mold according to claim 1, wherein the electroformed metal layer is made of at least one member selected from the group consisting of copper, iron, nickel, nickel-cobalt alloy, nickel-iron alloy, and nickel-phosphorous alloy. 3. The mold according to claim 1, wherein the bucking metal member is made of at least one member selected from the group consisting of iron, iron alloy, copper, and copper alloy. 4. The gold according to claim 1, wherein the first plating metal layer is made of at least one member selected from the group consisting of copper, iron, nickel, nickel-cobalt alloy, nickel-iron alloy, and nickel-phosphorus alloy. Type. 5. The mold according to claim 1, wherein a cast alloy layer is provided between the electroformed metal layer and the backing metal member with a second plating metal layer interposed therebetween. 6 The second plating metal layer is tin, copper, zinc, tin-zinc alloy, tin-lead alloy, tin-copper alloy and copper-
The mold according to claim 5, which is made of at least one member selected from the group consisting of zinc alloys. 7 The cast alloy layer is a bismuth-tin alloy, a bismuth-tin-zinc alloy, a bismuth-cadmium alloy,
tin-lead-cadmium alloy, tin-cadmium alloy,
Tin-lead alloy, tin-zinc alloy, tin-silver alloy, tin-copper alloy, tin-copper-antimony alloy, copper-zinc alloy,
The mold according to claim 5, which is made of at least one member selected from the group consisting of zinc-aluminum alloy, aluminum-copper alloy, silver solder, and gold solder. 8 (1) A step of forming an electroformed metal layer including the mold surface of the cavity portion on the outer surface of a metal mother mold, (2) A step of providing a notch along the outer periphery of the electroformed metal layer, (3 ) arranging a bucking metal member on the back side of the electroformed metal layer and forming a band-shaped space along the outer periphery of the boundary area between the two; and (4) forming a first plating metal layer in the band-shaped space. A method for manufacturing an electroforming mold, comprising: bonding an electroformed metal layer and a backing metal member. 9. The manufacturing method according to claim 8, wherein the electroformed metal layer is made of at least one member selected from the group consisting of copper, iron, nickel, nickel-cobalt alloy, nickel-iron alloy, and nickel-phosphorus alloy. 10 The bucking metal member is iron, an iron alloy,
The manufacturing method according to claim 8, which comprises at least one member selected from the group consisting of copper and copper alloys. 11. The production according to claim 8, wherein the first plating metal layer is made of at least one member selected from the group consisting of copper, iron, nickel, nickel-cobalt alloy, nickel-iron alloy, and nickel-phosphorus alloy. Method. 12. The manufacturing method according to claim 8, wherein a cast alloy layer is provided between the electroformed metal layer and the backing metal member with a second plating metal layer interposed therebetween. 13 The second plating metal layer is made of tin, copper, zinc,
The manufacturing method according to claim 12, which is made of at least one member selected from the group consisting of tin-zinc alloy, tin-lead alloy, tin-copper alloy, and copper-zinc alloy. 14 The cast alloy layer is a bismuth-tin alloy, a bismuth-tin-zinc alloy, a bismuth-cadmium alloy, a tin-lead-cadmium alloy, a tin-cadmium alloy, a tin-lead alloy, a tin-zinc alloy, a tin-silver alloy, Claim 12 consists of at least one member selected from the group consisting of tin-copper alloy, tin-copper-antimony alloy, copper-zinc alloy, zinc-aluminum alloy, aluminum-copper alloy, silver solder and gold solder. Manufacturing method described.