JPH0620641B2 - Method for manufacturing electroplated bellows mandrel for electroforming - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a mandrel, more specifically, a bellow-shaped peak and trough is formed on a peripheral surface of a mandrel molded body made of a metal or a synthetic resin material. Provided is a method of manufacturing a mandrel that accurately and smoothly connects the groove portions corresponding to the valleys and the guide portions on both sides corresponding to each crest half and prevents the inclined deformation during the processing of the convexly shaped crests. To do.

[Background of the Invention]

Conventionally, an electrodeposited bellows (a) as shown in FIG. 3 has been known as a kind of metal bellows.

This electrodeposited bellows (a) is widely used in lines that handle highly corrosive fluids and radioactive fluids under vacuum, high pressure and high temperature conditions by taking advantage of its excellent sealing performance, flexible expansion and contraction characteristics, and bending characteristics. Metal bellows are often used in fields requiring high performance and accuracy, and after mandrel surface made according to the inner shape of the bellows (a) is plated with metal of appropriate thickness. It is manufactured by an electroforming method in which only the mandrel is dissolved and removed by a chemical agent, and it is required to have a diameter of several millimeters and a thickness of several microns depending on the application.

[Conventional technology and its problems]

When manufacturing the above mandrel, prepare a cylindrical mandrel compact with a size corresponding to the inner shape of the bellows (a), and use a knife on its peripheral surface to form grooves and both sides corresponding to the peaks and valleys of the bellows. The guide part is cut. That is, the cutting process is performed with one pitch between adjacent peaks as one unit of the machining. As an example of the conventional method of the machining, as shown in FIG. 4, the groove portion (2) and both sides are formed. There is a method of cutting both parts (2) (3) (3) at the same time by a blade (11) provided with the shape of the guide part (3) (3) at a time, but according to this, the groove part (2) Although the contact points between the guide parts (3) and (3) on both sides can be obtained accurately, the contact area between the molded body (1) and the cutting tool (11) becomes large, which increases the cutting resistance and increases the molded body.
There is a problem that the surface condition of (1) becomes rough and the sealing property of the bellows (a) is hindered, and when the peak part (4) is thin, it will continue to be adjacent to the adjacent groove part (2 '). When cutting the guide portions (3 ') (3') on both sides of the bellows, the peaks (4) are inclined and deformed in the direction of the groove (2) previously processed, which adversely affects the product shape of the bellows (a). There's a problem.

As another example of the conventional method, as shown in FIG.
(2) Separately prepare a blade (12) for cutting (2 ') and a blade (13) for cutting both side guides (3), (3'), and use the former blade (12) to first cut the groove ( After cutting 2), there is a method of cutting both side guides (3) and (3) using the latter knife (13). According to this method, the blades (12) and (13) are selectively used and the groove (2) and the side guides (3) are used.
(3) is cut in stages, cutting resistance can be kept small and the surface of the molded body (1) can be kept in a good condition, but the contact point between the groove (2) and the side guides (3) (3) Will be inaccurate, and the bellows (a) will be impaired in sealing performance, expansion and contraction characteristics, and bending characteristics. If the ridges (4) are thin, the ridges (4) will move in the direction of the groove (2) that was previously machined, as in the previous example.
Is inclined and deformed.

In view of the above points, the present invention accurately and smoothly aligns the contact points of the groove portion and the guide portions on both sides, prevents inclination deformation of the mountain portion, and further manufactures an electroplated bellows electroforming mandrel for maintaining a good surface condition of the molded body. It is intended to provide a method.

[Means for solving problems]

In order to achieve this object, the manufacturing method of the present invention is a method for manufacturing an electrodeposited bellows electroforming mandrel, in which a cylindrical outer peripheral surface of a molded body is cut into a shape corresponding to the bellows by using a cutting tool. One set of groove portions corresponding to the V-shaped valley portion and R-shaped guide portions corresponding to the peak portions of the bellows on both sides of the outer peripheral end of the groove portions are alternately cut by the first blade, and at the same time, two sets adjacent to the groove portions are formed. The groove portions and the both side guide portions are alternately cut by a second blade arranged in a phase different from that of the first blade. At this time, the movements of the cutting edges of both of these knives are made symmetrical to both sides of the R-shaped guide portion between the groove portions as a starting point.

[Work]

In the above conventional example, the blades (11), (12) and (13) only move in the radial direction with respect to the molded body (1) which is the workpiece. On the other hand, according to the present invention, either one of the blade and the molded body can be freely moved with respect to the other by moving along with the cam mechanism or the like or NC control, or both of them can be moved to alternately cut the groove portion and the both side guide portions. . Further, two sets of groove portions adjacent to each other and the guide portions on both sides thereof are simultaneously subjected to cutting work by using two cutters, that is, both sides of the mountain portion are simultaneously cut under the same condition.

〔Example〕

 Next, examples of the present invention will be described.

As shown in FIG. 1, two blades (14) and (15) having substantially the same shape are used in the manufacturing method. Double knives (14) (15)
They are installed at 180-degree symmetrical positions around the axis of the molded body (1) which is the work piece, and each has a pair of grooves (2) (2 ') and both side guides (3) (3) (3'). I will be in charge of cutting work of (3 '). The blades (14) and (15) are moved from one guide portion (3) (3 ') to the groove portion (2) by copying or NC control as shown in FIG.
It is configured to continuously move from the groove portions (2) (2 ') to the other guide portions (3) (3') to the (2 '). In FIG. 2, the solid arrow indicates the movement of the blade (14), and the dotted arrow indicates the movement of the blade (15) at the 180-degree symmetrical position.

In the manufacturing method, the blades (14) and (15) are simultaneously directed to the cylindrical outer peripheral surface of the molded body (1) rotating about the axis, and
The R-shaped guide portion (mountain portion) between the groove portions (2) and (2 ') of the set is used as a common starting point, and from there, as shown by solid and dotted arrows in Fig. 2, each blade (14) (15) The two sets of grooves (2) (2 ') and their side guides (3) (3)
(3 ') and (3') are simultaneously and continuously machined.

Therefore, since each set is processed continuously, the groove
(2) Not only can the points of contact between the (2 ') and the guides on both sides (3), (3), (3'), and (3 ') be connected accurately and smoothly, but also the cutting resistance can be suppressed to a low level and the molded body (1 ) Can keep the surface smooth. Also, in the process of cutting two sets of groove portions (2) (2 ') adjacent to each other, the first and second blades are formed in the mountain portion (4) between them.
(14) The force from (15) acts from both sides. At this time, the two blades (14) and (15) are out of phase
The force acting on (4) also shifts in the circumferential direction, but the relief direction of the mountain portion (4) due to this is opposite every half rotation, so
It is possible to suppress the escape of the material to improve the processing accuracy, prevent damage to the blades (14) and (15), and improve the service life. Further, since the two blades (14) and (15) are arranged at 180-degree symmetrical positions to balance the cutting resistance, the life of the blades (14) and (15) can be extended also from this point. If two blades are arranged side by side, the thickness of the blade holder becomes too thin and the strength becomes weaker when the pitch dimension is narrow, and further, the cutting powder is clogged between the two blades to form the blade or molding. Double-edged tool (14) (15)
Such an adverse effect can be prevented by angularly displacing the resin in the circumferential direction of the molded body (1).

Although not shown in the drawing, the groove portions (2) (2 ') are first cut by the blades (14) (15), and then the guide portions (3) (3').
Of the guides (3) and (3 ') are alternately machined first, and then the groove is formed.
(2) A method of cutting (2 ') is also possible. In each case, the same (one) blade (14) (15) is used to form the groove (2) (2 ')
Since the guide parts (3) and (3 ') are alternately machined, operations such as positioning of the blades (14) and (15) are easier than before, and the same effect as the above embodiment can be obtained. You can

In the above embodiment, two sets of grooves (2) (2 ') and their guides (3) are used.
(3) (3 ') (3') has been described on the premise that it is cut, but the present invention is not limited to this, and can be used in the case of three or more sets. By displacing it, the same effect as that of the above embodiment can be obtained.
In this case, it is desirable to arrange or integrally mold the odd-row blades and even-row blades in a comb-like shape, which can significantly reduce the processing time and supply a good and inexpensive mandrel. Becomes

〔The invention's effect〕

The method of manufacturing the electroplated bellows electroforming mandrel of the present invention has the characteristics as described above, and the contact between the groove portion and the guide portions on both sides is accurately and smoothly aligned and the surface of the mandrel is made smooth, so that the sealing property is excellent. The electrodeposited bellows can be obtained, and the contact point becomes accurate, so that the expansion and contraction characteristics and bending characteristics of the electrodeposited bellows can be improved. Again 2
Since the groove portions of more than one set and the guide portions on both sides thereof are simultaneously processed to suppress the inclination deformation of the mountain portion, the extremely small and thin electrodeposited bellows can be easily manufactured.

[Brief description of drawings]

1 and 2 are explanatory views of a manufacturing method according to an embodiment of the present invention, FIG. 3 is a sectional view of an electrodeposited bellows, and FIGS. 4 and 5
The drawings are illustrations of manufacturing methods according to different conventional examples. (1) ...... Mandrel molded body, (2) (2 ') ...... Groove part (3) (3') ...... Both side guide part, (4) ...... Mountain part (11) (12) (13) (14) ) (15) …… Blade

Claims (1)

[Claims] 1. A method of manufacturing an electroplated bellows electroforming mandrel, wherein a cylindrical outer peripheral surface of a molded body is cut into a shape corresponding to a bellows by using a cutter, and a set of a set corresponding to a U-shaped valley portion of the bellows is formed. The groove portion and the R-shaped guide portions on both sides of the outer peripheral end of the groove portion, which correspond to the mountain portion of the bellows, are alternately cut by the first blade, and at the same time, the groove portion and the both-side guide portions of the second set adjacent to the groove portion are firstly cut. Alternately cutting with one blade and a second blade arranged at a different phase, and making the operations of the blade edges of both blades symmetrical to both sides of the R-shaped guide portion between the two groove portions as a starting point. A method of manufacturing a mandrel for electroforming bellows, which is characterized.