JPH0124875B2 - - 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 an electroformed mother mold generally has a complicated shape, which requires precision 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, plating the uneven portions formed on the surface requires a considerable amount of time and time. 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" This invention applies plating to the surface of a base core so as to cover its uneven parts, and inserts the base core into a metal reinforcing frame having an inner diameter that almost circumscribes the base core.
A filler is filled into the space formed between the reinforcing frame and the base core, the filler is activated, and plating is applied to the surfaces of the filler, base core, and metal reinforcing frame so as to enclose them. This is what was done.

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

That is, in FIGS. 1 and 2, the mother core 1 is formed by machining an aluminum material, for example, and has a large number of recesses 2 and protrusions 3 on its outer peripheral 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.

First of all, on the surface of this core, there are especially uneven parts 2,
3 to a predetermined thickness, for example 1~
Apply 2mm. This plating is performed slowly with a low current density and over a sufficient period of time. As a result, the first plating layer 5 is formed, and the uneven portions 2 and 3 are smoothly covered with this first plating layer.

In the case of small parts, the thickness of the first plating layer 5 is desirably about half the depth of the recess of the base core 1.

Next, a metal reinforcing frame 7 having an inner diameter substantially circumscribing the core 1 coated with the first plating layer 5 is prepared. The outer diameter dimension of this reinforcing frame is set smaller than the finished dimension of the entire matrix by a predetermined dimension, for example, 2 to 3 mm. Also, the length of this metal reinforcing frame in the axial direction,
That is, the thickness is set to be shorter than the length of the core 1 in the axial direction. The mother core 1 is inserted into this metal reinforcing frame so that its outer periphery is substantially in contact with the inner periphery of the frame. In this state, a space is formed between the metal reinforcing frame 7 and the core 1 due to the concave portion of the core.

Subsequently, this space is filled with a filler made of ceramic cement, thereby forming a filled layer 11. In this state, the base core 1 and the metal reinforcing frame 7
are connected to each other.

Further, on a surface of the metal reinforcing frame that intersects with the base core 1, a curved portion 8 is formed at a corner formed together with the base core to smoothly connect the two to each other. This curved portion is formed by bulging the filling layer 11 outward from the corner. Note that this curved portion may be formed by forming a concave curved surface on the metal reinforcing frame 7 itself at the corner thereof, and the method for forming the curved portion is appropriately selected depending on the shape or size of the core 1.

Next, the surface of the filling layer 11 is activated with tin chloride, palladium chloride, or the like, and further electroless plating is applied thinly to the surface, thereby imparting electrical conductivity to the filling layer 11.

Next, electroplating is applied to the surfaces of the core 1, the filling layer 11, and the metal reinforcing frame 7 to a predetermined size, for example, 1 to 2 mm, so as to completely envelop them. As a result, the second plating layer 12 is formed.

In the molded body thus obtained, the second plating layer 12 is ground by a predetermined dimension along the outer periphery of the metal reinforcing frame 7 using a lathe. Further, the second plating layer 12 is ground by a predetermined dimension on both side surfaces intersecting the axis of the molded body, and a part of the core 1 is ground to expose the core.

Next, the molded body is immersed in a caustic soda solution to dissolve the mother core 1. This completes the electroforming master mold.

"Effects" As described above, this invention applies plating to the base core so as to cover its uneven parts, inserts the base core into a metal reinforcing frame having an inner diameter that almost circumscribes the base core, and connects the base core with the metal reinforcing frame. A filler is filled in the space formed between the core and the filler is activated, and plating is applied to wrap around the base core, filler, and metal reinforcing frame, so that only the base core is melted. Therefore, an electroformed mother mold having sufficient strength, heat resistance, and pressure resistance can be obtained in a short time.

[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...
First plating layer, 7... Metal reinforcing frame, 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 core having an uneven surface, the core is reinforced with metal having an inner diameter that substantially circumscribes the core. inserting it into a frame, filling the space formed between the reinforcing frame and the mother core with a filler to connect the mother core and the metal reinforcing frame, and then activating the filler, After that, plating is applied so as to enclose the filler, the mother core and the metal reinforcing frame, the mother core and the metal reinforcing frame are integrated, and only the mother core is melted. Production method. 2. The method of manufacturing an electroforming mother mold according to claim 1, wherein the filler is made of ceramic cement. 3. A first plating layer applied to a base core having an uneven surface and covering the irregularity with a predetermined thickness, and an inner diameter substantially circumscribing the outer diameter of the base core on which the plating layer is applied. and a metal reinforcing frame for accommodating the mother core, a filling layer filled between the reinforcing frame and the mother core and connecting the mother core and the metal reinforcing frame to each other, the filling layer, An electroforming mother mold comprising a second plating layer formed on the surface of the mother core and the metal reinforcing frame so as to integrally wrap them. 4. The electroforming mother mold according to claim 3, wherein the filling layer is made of ceramic cement. 5 The length of the base core in the axial direction is set to be longer than the length of the metal reinforcing frame in the axial direction, and
The electroformed base according to claim 4, wherein a curved part is formed at a corner formed together with the base core on a surface of the metal reinforcing frame that intersects with the base core to smoothly connect the two to each other. Type.