JPH1025592A - Production of parts having recessed part on inner circumference - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an internal gear by utilizing electroforming. SOLUTION: Af first, an electrodepositing layer 11 to form into an internal gear is formed on the outer circumferential side of a pattern 6 by electroforming. Next, the pattern 6 is cut off at a position in which the tip of the projected part 2 of the inner circumferential face of the electrodepositing layer 11 is enveloped by wire discharge working. Then, the projected part 8 of the pattern 6 remaining in the recessed part 3 of the inner circumferential face of the electrodepositing layer 11 is removed. By the process of the above two stages, the electrodepositing layer 11 can be peeled from the pattern 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a component such as an internal gear having an uneven portion on an inner periphery, and more particularly to a method using electroforming.

[0002]

A polishing process is used for producing a high-precision gear. However, in the case of the internal gear, production by polishing is troublesome and costly.

Therefore, it has been considered to use electroforming to manufacture a highly accurate internal gear. That is, in the case of electroforming, if an external gear-shaped prototype is manufactured with high precision, it should be possible to easily manufacture an internal gear using this prototype. However, in the case of electroforming, an electrodeposited layer as a part cannot be peeled off from a prototype in a shape like an internal gear. In order to make the electrodeposition layer detachable from the original, the inner peripheral surface of the electrodeposition layer must be tapered to have a draft, but this is not allowed in the specification of the internal gear.

[0004] The present invention is intended to solve such a problem, and is intended to easily and accurately manufacture a component having an uneven portion on an inner periphery such as an internal gear using electroforming. The purpose is to do.

[0005]

According to a first aspect of the present invention, there is provided a method of manufacturing a component having an uneven portion on an inner periphery, wherein a convex portion and a concave portion are arranged on an inner peripheral surface in a circumferential direction. In the method for manufacturing a component, a pattern forming step of forming a pattern having a transfer shape of the inner peripheral surface shape of the component on the outer peripheral surface, and an electroforming step of forming an electrodeposition layer on the outer peripheral side of the pattern by electroforming. ,
A wire electric discharge machining step of cutting out a prototype at a position enclosing the top of the convex portion of the inner peripheral surface of the electrodeposited layer by wire electric discharge machining, and remaining in a concave portion of the inner peripheral surface of the electrodeposited layer after this wire electric discharge machining step And a residual portion removing step of removing the original mold.

[0006] In particular, the wire electric discharge machining step makes it possible to peel off the electrodeposition layer as a part from the original mold. That is, when the prototype is cut out at a position enveloping the top of the convex portion of the inner peripheral surface of the electrodeposited layer, the prototypes remaining in the concave portion of the inner peripheral surface of the electrodeposited layer are separated from each other, and the inner peripheral portion is separated therefrom. Since there is nothing on the side, it can be easily removed from the electrodeposited layer.

According to a second aspect of the present invention, there is provided a method of manufacturing a component having an uneven portion on the inner periphery according to the first aspect of the present invention, wherein the length of the original mold in the axial direction is reduced by a plurality of components in order to further improve the manufacturing efficiency. , And after the electroforming step, the electrodeposition layer or the electrodeposition layer and the prototype are cut to a length corresponding to one part.

[0008] Since the prototype is cut, it can be used only once for the production of parts. In the invention of claim 2, a plurality of parts can be produced by producing one prototype.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing a component having an uneven portion on the inner periphery according to the present invention will be described below with reference to the drawings. The component manufactured in this embodiment is the internal gear 1 as shown in FIGS. 1 (d) and 2 (b). In this internal gear 1, a plurality of convex portions 2 and concave portions 3 forming teeth are arranged in a circumferential direction on an inner peripheral surface. The inner peripheral surface and the outer peripheral surface of the internal gear 1 are shaped such that one central axis parallel to them is determined.

In manufacturing the internal gear 1, first, a prototype 6 as shown in FIGS. 1A and 2A is prepared (prototype forming step). The prototype 6 is made of a conductive metal material using an appropriate processing method such as grinding, and has a transfer shape of the inner peripheral surface shape of the internal gear 1 on the outer peripheral surface. That is, the prototype 6 has a plurality of concave portions 7 forming the convex portions 2 of the internal gear 1 and a plurality of convex portions 8 forming the concave portions 3 of the internal gear 1. The axial length of the prototype 6 is set to the length of a plurality of the internal gears 1 to be manufactured.
Reference numeral 9 denotes a shaft for holding the prototype 6 when the prototype 6 and the internal gear 1 are manufactured.
Are located on the central axis of the prototype 6 and protrude from both end surfaces thereof.

Next, as shown in FIG. 1B, an electrodeposition layer 11 is formed on the outer peripheral side of the prototype 6 by electroforming (electroforming step). The material of the electrodeposition layer 11 is, for example, nickel.
The hardness of the electrodeposition layer 11 is, for example, about HRC65.

Next, as shown in FIG. 1C, the prototype 6 is wrapped by wire electric discharge machining at a position surrounding the top of the convex portion 2 (the tooth bottom of the prototype 6) on the inner peripheral surface of the electrodeposition layer 11. Cut out (wire electric discharge machining process). In the drawings, the wire path at the time of wire electric discharge machining is substantially circular. However, the present invention is not limited to this, and the wire path may be appropriately determined according to the shapes of the concave portion 2 and the convex portion 3. In short, after the wire electric discharge machining process, the remaining portions (convex portions 8) of the prototype 6 remaining in the respective concave portions 3 on the inner peripheral surface of the electrodeposition layer 11 are separated from each other, and what is on the inner peripheral side therefrom. It is only necessary that there is no remaining. However, in order not to impair the accuracy of the electroforming, it is better to minimize the distance that the wire path passes through the boundary between the prototype 6 and the electrodeposition layer 11.

Next, as shown in FIG. 1 (d), each projection 8 of these prototypes 6 is removed from the electrodeposited layer 11 (residual portion removing step). At this time, since the projections 8 are separated from each other as described above, these projections 8 are
11 can be easily removed.

Further, as shown in FIG. 2B, the electrodeposition layer 11 having a length corresponding to a plurality of the internal gears 1 is cut into a length corresponding to one internal gear 1 (FIG. 2B). Predetermined length cutting step).
This predetermined length cutting step can be performed at an appropriate stage after the electroforming step. When the predetermined length cutting step is performed after the residual part removing step, there is an advantage that the wire electric discharge machining step and the residual part removing step can be simultaneously performed on the plurality of internal gears 1. In addition, when performing before the wire electric discharge machining process, the prototype 6 is cut at the same time.
Has an advantage that deformation of the electrodeposited layer 11 during processing can be prevented.

Further, if necessary, the internal gear 1 is completed by performing appropriate post-processing such as polishing the end face and the outer peripheral face of the internal gear 1, but the internal gear 1 is formed with high precision by electroforming. It is not necessary to perform post-processing on the inner peripheral surface of the internal gear 1.

As described above, according to the configuration of the above embodiment, after the prototype 6 is cut out by wire electric discharge machining at the position surrounding the top of the convex portion 2 on the inner peripheral surface of the electrodeposition layer 11, the electrodeposition layer 11 is cut.
Since the protruding portion 8 of the prototype 6 remaining in the concave portion 3 on the inner peripheral surface of the 11 is removed, the electrodeposition layer 11 can be peeled off from the prototype 6 even with the internal gear 1, and electroforming is performed. Can be manufactured. Then, by manufacturing the internal gear 1 using electroforming, the internal gear 1 can be easily manufactured with high accuracy.

Further, since the protruding portion 8 is cut in the wire electric discharge machining process, the prototype 6 can be used only once for manufacturing the internal gear 1, but in the above embodiment, one prototype 6 is used.
Is lengthened, and a plurality of internal gears 1 are obtained by cutting the electrodeposited layer 11 formed thereon, so that if one prototype 6 is formed, a plurality of internal gears 1 can be manufactured, and manufacturing efficiency is improved.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made. For example,
In the above embodiment, the manufactured part is the internal gear 1,
The component to be manufactured is not limited thereto, and can be generally applied to a component in which a convex portion and a concave portion are arranged in the circumferential direction on the inner peripheral surface, such as an inner rotor of an oil pump.

[0019]

According to the first aspect of the present invention, there is provided a method of manufacturing a component in which a convex portion and a concave portion are arranged in a circumferential direction on an inner circumferential surface, wherein the inner circumferential surface of the electrodeposition layer formed on the outer circumferential side of the original mold. After cutting out the mold by wire electric discharge machining at the position enveloping the top of the convex part, remove the mold remaining in the concave part on the inner peripheral surface of the electrodeposition layer, so that parts such as internal gears are formed by electroforming. It can be easily manufactured with high precision.

According to the second aspect of the invention, in addition to the effect of the first aspect, the axial length of the prototype is set to a length corresponding to a plurality of parts, and the electrodeposition layer or the electrodeposition layer is formed after the electroforming step. Since the layer and the pattern are cut to a length corresponding to one part, if one pattern is created, a plurality of parts can be manufactured, and the manufacturing efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a method for manufacturing a component having an uneven portion on the inner periphery according to the present invention, wherein FIG.
(B) shows the state after the electroforming step, (c) shows the state after the wire electric discharge machining step, and (d) shows the state after the residual part removing step.

FIG. 2A is a perspective view of the prototype, and FIG. 2B is a perspective view of an internal gear.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal gear (part) 2 Convex part 3 Concave part 6 Prototype 11 Electrodeposited layer

Claims (2)

[Claims] 1. A method of manufacturing a component in which convexes and concaves are arranged in a circumferential direction on an inner peripheral surface, wherein a prototype having a transfer shape of an inner peripheral surface shape of the component on an outer peripheral surface is produced.
An electroforming step of forming an electrodeposition layer on the outer peripheral side of the mold by electroforming, and a wire electric discharge machining step of cutting out the mold at a position enclosing the top of the convex portion of the inner peripheral surface of the electrodeposition layer by wire electric discharge machining. And a step of removing a mold remaining in a concave portion of the inner peripheral surface of the electrodeposited layer after the wire electric discharge machining step. 2. The method according to claim 1, wherein the length of the mold in the axial direction is set to a length corresponding to a plurality of parts, and the electrodeposition layer or the electrodeposition layer and the mold are cut to a length corresponding to one part after the electroforming step. The method for producing a component having an uneven portion on an inner periphery according to claim 1.