JPH0124876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field of interest] This invention relates to an electroforming mold and a method for manufacturing the same.

"Prior Art" The surface of a mother core for forming an electroformed mother mold generally has a complicated shape, and therefore precision is required even though machining is difficult. Therefore, an electroformed mother mold is obtained by plating the surface of the mother core, but due to its nature, it takes a considerable amount of time to plate the uneven portions formed on the surface. In other words, uneven areas are plated at a low current density and over a long period of time, and when the surface of this plating layer becomes smooth, the current density is increased again to form a reinforcing plating layer at high speed. However, the plating layer for reinforcement is generally about 10-odd millimeters thick, and it has the disadvantage that it takes several days to more than 10-odd days to plating that thickness.

"Purpose" This invention takes into account the drawbacks of the conventional technology,
The purpose is to form an electroforming mother mold having sufficient mechanical strength, heat resistance, and pressure resistance in a short time.

"Summary" In order to achieve the object, the present invention smoothes the irregularities formed on the surface of the base core by plating, and also makes the base core elastic with an inner diameter larger than the outer diameter of the base core. Insert into rich injection mold,
A filler is filled between the injection mold and the base core, the surface of the filler is activated, and the surface of the base core is plated with the filler so as to wrap them both, thereby integrating the two. Furthermore, the electroforming mother mold is formed by melting only the mother core.

"Embodiment" An embodiment of the present invention will be described below with reference to the drawings.

That is, in FIGS. 1 and 2, the base core 1
A large number of concave portions 2 and convex portions 3 are provided on its surface. For example, if the core 1 is a pinion gear, an uneven portion consisting of peaks and valleys is formed on its outer periphery. Note that this core is formed, for example, by machining an aluminum material.

First of all, on the surface of this core, there are especially uneven parts 2,
3 to a predetermined thickness, for example 1~
Approximately 2 mm is applied, but at this time the current density is low and the process is done slowly over time. As a result, the uneven portions 2 and 3
is smoothly covered with the first plating layer 5.

Next, a casting mold 7 is prepared which has an inner diameter that is a predetermined dimension larger than the outer diameter of the mother core on which the first plating layer has been applied, and 1 to 4 mm smaller than the finished dimension of the mother mold set in advance. The material of this injection mold is not particularly limited, but it is advantageous to use silicone rubber (RTV) because it is easy to manufacture and easy to release from the mold.

Therefore, the base core 1 with the first plating layer 5 formed thereon is inserted into this injection mold, and the space formed between the base core, that is, the first plating layer 5 and the injection mold 7 is filled with a filler. The filling layer 11 is formed by curing this. The filler forming this filled layer must be made of a material that can sufficiently withstand the temperature and pressure used as the electroforming mold, and for example, ceramic cement is used.

Next, this filled layer is taken out from the injection mold 7 together with the mother core 1, and the surface of the filled layer 11 is activated with, for example, tin chloride or palladium chloride. This enables electrodeposition on the surface of the filling layer 11.

Next, nickel is applied to the surface of the activated filling layer 11 and the surface of the mother core 1 by electroless nickel plating to a thickness of several microns, and then electroplated on the surface by about 1 mm further than the finished dimensions. Apply extra. As a result, the second plating layer 12 is formed.

Thereafter, in this formed body, the outer periphery of the second plating layer centered on the axis of the core 1 is ground by a predetermined dimension, for example, 1 mm. Further, both side surfaces of the formed body intersecting the axial center line are ground to a predetermined size, and both side surfaces of the mother core 1 are exposed, and the mother core is further dissolved with caustic soda.

This completes the electroforming master mold.

"Effects" As described above, this invention applies plating to the surface of the base core so as to cover its uneven parts, and then the base core is made of elastic material having an inner diameter that is larger by a predetermined dimension than the outer shape of the base core. The space formed between the injection mold and the base core is filled with a filler, and the injection mold is then removed to activate the surface of the filler. Since the surface of the mother core is plated so as to envelop both of these, the electroforming mother mold is not only extremely easy to form, but also has sufficient mechanical strength, heat resistance, and pressure resistance. The mold can be molded in a short time, which is extremely advantageous in terms of the rotation rate of the plating layer, the consumption of electrodes, and the power consumption.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the manufacturing process of an electroforming mold according to the present invention, and FIG. 2 is a front sectional view. 1... Mother core, 2... Concave portion, 3... Convex portion, 5...
1st plating layer, 7... injection mold, 11... filling layer, 12... second plating layer.

Claims (1)

[Scope of Claims] 1. After applying plating to a predetermined thickness to cover the uneven portions of a base core having an uneven surface, the base core is compared to the outer shape of the base core to obtain a predetermined dimension. The injection mold is inserted approximately into the center of a highly elastic injection mold having a large inner diameter, and then the space formed between the injection mold and the mother core is filled with a filler, and then the injection mold is inserted into the mold. removing the filler, activating the surface of the filler, plating the surfaces of the filler and the base core so as to wrap them together, integrating the two, and then melting only the base core. Method of manufacturing a casting mold. 2. The method of manufacturing an electroforming mother mold according to claim 1, wherein the injection mold is made of silicone rubber. 3. The method of manufacturing an electroforming mother mold according to claim 1, wherein the filler is made of ceramic cement. 4. The method for producing an electroforming mother mold according to claim 1, wherein the surface of the filler is activated with tin chloride or palladium chloride. 5 A first plating layer applied to a base core having an uneven surface and covering the irregularity with a predetermined thickness, and a first plating layer having elasticity and having a predetermined dimension compared to the outer shape of the base core. An injection mold having a large inner diameter into which the mother core is inserted; a filling layer formed between the injection mold and the mother core; and a filling layer formed between the filling layer and the mother core with the injection mold removed. An electroforming mother mold having a second plating layer on the surface that surrounds both of them and integrates them. 6. The electroforming mother mold according to claim 5, wherein the injection mold is made of silicone rubber. 7. The electroforming mother mold according to claim 5, wherein the filling layer is formed of a filler mainly consisting of ceramic cement.