JPS591692A - Electroforming method - Google Patents

Abstract

PURPOSE:To increase the deposition speed of plating and to easily manufacture an electroformed product having an internal cooling path, by holding a matrix at the center of a ringlike bent pipe and by uniting them in a body by electroforming. CONSTITUTION:A matrix 4 of Al or the like consisting of a shaft 5 and a gear 6 is held at the center of a copper pipe 1 for a cooling path consisting of a ring part 2 and connecting parts 3. After covering the parts 3 with plugs 7 made of an electric insulator such as plastics, the pipe 1 and the matrix 4 are immersed in an Ni plating soln. 9 in a plating vessel 8 and electroplated to form an Ni block 10 having a prescribed size over the large area of the pipe 1 and the matrix 4 in a short time. Thus, the pipe 1 and the matrix 4 are united in a body by electroforming. The Ni block 10 is cut to the thickness corresponding to the length of the gear 6, and the matrix 4 is dissolved in an NaOH soln. or the like to obtain a cavity 11 having the inserted copper pipe 1 for a cooling path.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electroforming method suitable for manufacturing, for example, gear cavities for plastic molds.

[Technical gastric tube of the invention and its problems]

For example, the gear cavity mentioned above has a complicated shape.
It is often manufactured by electroforming. In that case, first, a mother mold is manufactured from kA or its alloy, and the mother mold is immersed in a plating bath mainly composed of INt to precipitate N1 around the mother mold to form a Ni lump several tens of parts thick. Next, the Ni lump in which the matrix was buried was cut into a predetermined shape for 710 millimeters, and then immersed in an etching solution that would dissolve only the matrix. obtain. This cavity is then embedded in the template.

By the way, when a cavity is manufactured by such electroforming, the cavity is embedded in a template, and therefore requires strength to prevent deformation during embedding. Therefore, N! around the mother mold! Since the cavity must be deposited to a thickness of approximately 20 to 30 m to provide a certain strength, there is a drawback that the plating time is very long.

In addition, in gear cavities for molds that are affected by heat, it is necessary to cool them to reduce variations in molded products from molding shot to molding shot due to thermal deformation. Conventionally, a cooling path was formed in the template, but as mentioned above, if the wall thickness of the cavity is thick, the cooling path formed in the template cannot reliably cool the cavity. Another drawback was that molded products could not be obtained.

[Purpose of the invention]

An object of the present invention is to provide an electroforming method that can increase the deposition rate of plating and form a cooling path inside an electroformed product.

[Summary of the invention]

This is an electroforming method in which a master mold is held in the center of a ring-shaped pipe forming a cooling path, and the pipe and the master mold are electroformed together.

[Embodiments of the invention]

Hereinafter, the case of manufacturing a gear cavity for a mold according to the present invention as shown in the drawings will be explained.

First, Fig. 1 shows a copper pipe f1 forming a cooling path, and this copper pipe 7'' is connected to the ring part 2 and the outer periphery of this ring part 2.
It consists of a pair of connecting parts 3, 3 connected at positions shifted by 0 degrees. On the other hand, FIG. 2 shows a mother mold 4 made of aluminum or its alloy, and this mother mold 4 has a gear 6 formed at one end of a shaft body 5. As shown in FIG.

The copper 9 ide 1 and the matrix 4 configured in this way are the third
As shown in the figure, the mother die 4 is held in the center of the ring part 2 of the copper wire f1 with a jig (not shown), such as a nickel wire, and an electrical insulator such as plastic is attached to the connection part 3.3. These are then immersed in the plating solution 9 of the plating bath 8. Then, connect the steel pipe 1 and the master mold 4 to the cathode of a DC power supply to
I plate it. Then, Ni is deposited on the surfaces of the copper pipe 1 and the matrix 4, and the Ni lump 10 electroforms them into one piece. At this time, NIFi copper mother Iso 1 and mother mold 4
Since the Ni lump 10 is precipitated from both sides, the precipitation time for the Ni lump 10 to reach a predetermined size is about half that of the case without the copper pipe 1. Plating time is reduced.

After electroforming the copper 9-beam 1 and the mother mold 4 in this way, the stubble 10 is made into a thickness corresponding to the length of the gear 6 of the mother mold 4 as shown in FIG. This is then processed using an etching solution such as NaO in which only the matrix 4 is dissolved.
The mother mold 4 is dissolved by dipping it in H solution to obtain a cavity 11' (r) having an inverse shape of the gear 6 as shown in FIG. Then, the cavity 1 embedded in the template 12
), the connection part 3°3 of the copper pipe 1 is attached to the above template 12tlC.
The formed cooling medium flow path No. 3 is brought into fluid-tight communication via an O-ring 14.

According to such a template 12, since the copper pipe 1 forming a cooling path is buried in the Ni lump 10 forming the cavity 11, the cooling medium is allowed to flow through the copper pipe 1 through the flow path 13. If so, the cavity 11'J&: can be cooled well.

In addition, the electroforming method of this invention applies only to the gear cavity VC1.
It can also be applied to the production of other mold cavities and electrodes for electrical discharge machining.

〔Effect of the invention〕

As described above, in the present invention, the mother mold is held in the center of a pipe forming a cooling path curved into a ring shape, and the mother mold and the mother mold are integrally electroformed. Therefore, since the plate and the matrix are plated at the same time,
Compared to conventional electroforming that does not use Iso, electroformed ingots of a predetermined size can be obtained at about twice the speed. In addition, the above i? used as a cooling path? The eve is embedded in the electroformed ingot, and the electroformed ingot is directly cooled by the cooling medium passed through the ingot, so if the electroformed ingot is used for the mold cavity, it will be stable. The cooling effect can improve the molding accuracy of molded products.

[Brief explanation of the drawing]

The drawings show a practical example of this invention; Fig. 1 is a plan view of the mother die forming the cooling path; Fig. 2 is a side view of the mother die; and Fig. 3 is the plating of the pipe and the mother die. Explanatory diagram of the state of
The figure is a cross-sectional view of the electroformed ingot cut into a predetermined shape, Figure 5 is a cross-sectional view of the cavity after removing the matrix from the electroformed ingot, and Figure 6 is a cross-sectional view of the cavity embedded in the template. I'll go. 1... Mother Eve, 4... Mother mold, 10... Electroformed ingot,
1. Cavity.

Claims (1)

[Claims] An electroforming method characterized by holding a master mold in the center of a tube that forms a cooling path curved into a ring shape, and electroforming the pipe and the master mold as one unit.