JPH0242297B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method for manufacturing a molded bellows, and more specifically, in a molded bellows formed by welding an end member to the end of a bellows component, solidification cracks are formed in the welded portion. The present invention provides a method for manufacturing a molded bellows that is devised to prevent the occurrence of blowholes and blowholes.

[Conventional technology]

Conventionally, as a type of molded bellows, one in which an end member such as a flange made of beryllium copper is welded to the end of a thin molded bellows part made of beryllium copper is known.

This molded bellows is manufactured by forming a bellows molding material previously formed into a tube shape into a bellows shape using a forming jig, and then electron beam welding an end member to the end thereof.

[Problem that the invention seeks to solve]

In the above molded bellows, the bellows parts are approximately
The flange, which is formed to a thickness of 70μ and thinly welded to the bellows part, is processed to a thickness of about 200μ, and due to this difference in thickness, there is a difference in the direction and time of heat dissipation immediately after welding to both parts. This may cause solidification cracks (hair cracks) or blowholes within the weld, or pinholes may occur in the bellows core. Another drawback is that a stable bead cannot be formed because the thin bellows side melts first.

[Means for Solving the Problems] In view of the above points, the present invention aims to provide a method for manufacturing molded bellows that does not cause problems such as solidification cracks and can form stable beads. In order to achieve the purpose, in a method for manufacturing a molded bellows, in which a tube-shaped material is molded into a bellows part, and an end member such as a flange is welded to the end of the bellows part, in the step of molding the bellows part, A filler ring was assembled to the end of the component, and the end of the bellows component was welded to be sandwiched between the end member and the filler ring.

[Effect]

That is, in the manufacturing method of the present invention, a filler ring having a required thickness is added to the welded part of the bellows part and the end member, and the end of the bellows part is sandwiched in a sandwich shape and welded. Since the welding part is located at the center of the welding part, it is possible to prevent the above-mentioned problems caused by uneven welding from occurring. In addition, since the filler ring, which is made of the same material as the bellows part, is integrally assembled to the end of the bellows part during the molding stage, the ring, which is integrally formed in an annular shape, can be easily aligned concentrically with the bellows part. can be assembled into.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 shows an example of a molded bellows manufactured by this manufacturing method, in which flanges 4 and plates 5, also made of beryllium copper, are welded and fixed to both ends of a bellows part 1 made of beryllium copper, and the bellows parts are fixed at each welded part. The outer ends 2, 3 are sandwiched between the flange 4 or plate 5 and the filler rings 6, 7 and are electron beam welded at their outer diameters. Filler rings 6 and 7 are bellows parts 1
It is preformed into an annular shape from the same beryllium copper as .

When manufacturing the above-mentioned molded bellows, first, as shown in FIG.
are fitted and mounted on a forming jig 8 as shown in FIG. The pieces 9 and 10 at both ends of the forming jig 8 are filled with filler rings 6 and 7 in advance.
Annular notches 11 and 12 are provided to engage the
Filler rings 6 and 7 are fitted into these notches 11 and 12. In this state, the molding material 1' is formed, and the filler rings 6, 7 are integrally assembled into the valleys of the bellows part 1 so as to be adjacent to the ends 2, 3 of the part 1, as shown in FIG. Next, the bellows part 1 removed from the forming jig 8 is
It is fitted into the split welding jig 13 and welding is performed. This welding jig 13 is used to prevent welding burnt and deterioration of the bellows part 1, and covers almost the entire bellows part 1 as shown in FIG. The parts 2 and 3 are supported from the inside. Bellows part 1 in this state
Attach the flange 4 and plate 5 to the setting jigs 14 and 15 of the multi-index table, and then attach the ends 2 and 3 of the bellows part 1 and the filler rings 6 and 7.
The three members, flange 4 or plate 5, are tightened so that they are in close contact with each other, and the outer diameter surface of the contact portion is welded over the entire circumference by an electron beam method.

The molded bellows manufactured by the above manufacturing method is
At the welding part, the ends 2 and 3 of the bellows part 1 are sandwiched between the filler rings 6 and 7 and the flange 4 or the plate 5 in a sandwich-like manner, and are located in the center of the welding part, so that the welding becomes uneven. Since the bead is formed uniformly from front to back without any problems, it is possible to prevent the occurrence of coagulation cracks and the like, and at the same time, it is possible to form a stable bead. In addition, since the filler rings 6 and 7 are assembled to the bellows part 1 at the stage of molding the bellows part 1, there is no need to divide the filler rings into two parts as required when attaching the filler rings later, and the filler rings can be molded into an annular shape, which simplifies the assembly work. At the same time, concentricity with respect to the bellows component 1 can be maintained easily and with high precision during assembly.

〔Effect of the invention〕

As explained above, the method for manufacturing the molded bellows of the present invention includes assembling a filler ring to the end of the bellows component in the step of molding the component, and sandwiching the end of the bellows component between the end member and the filler ring. The above-mentioned action can prevent the occurrence of solidification cracks, etc.
This makes it possible to stabilize the shape of the bead formed at the same time. Further, the filler ring formed in an annular shape can be easily and precisely assembled to the bellows component, and a high quality molded bellows with a small amount of leakage can be manufactured as a whole.

[Brief explanation of the drawing]

FIG. 1 is a half-cut sectional view showing an example of a molded bellows manufactured by the method of the present invention, and FIGS.
Each figure is an explanatory diagram of the process. 1... Bellows parts, 2, 3... Ends, 4...
Flange, 5... Plate, 6, 7... Filler ring, 8... Forming jig, 9, 10...
Piece, 11, 12... Notch, 13... Welding jig,
14, 15... Setting jig.

Claims (1)

[Claims] 1. A method for manufacturing a molded bellows, in which a tube-shaped material is molded into a bellows part, and an end member such as a flange is welded to the end of the bellows part,
Production of a molded bellows, characterized in that, in the step of molding the bellows part, a filler ring is assembled to the end of the part, and the end of the bellows part is welded to be sandwiched between the end member and the filler ring. Method.