JPH04266428A - Manufacture of thin multilayer plate - Google Patents

Abstract

PURPOSE:To obtain a new press forming method to prevent wrinkles from being generated on a blank in time of forming as regards a method to perform a precise hot deep drawing operation to a semi-spherical thin end plate having a large diameter such as a rocket chamber container. CONSTITUTION:A flat blank 1 to be formed is put between sandwich materials 2, 2 having a satisfactory thickness each from both upper and lower surfaces, a spacer 3 is arranged on the outer periphery of the blank 1 put between both sandwich materials 2, 2', the outer periphery of this spacer 3 is welded to make up a sandwich member, then, hot deep drawing is performed by a male die 5 and a female die 6 to integrally form a semispherical end plate. In this case, solidification by welding the periphery of the sandwich member is not removed and wrinkles are not generated on the blank 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for precisely performing hot press deep drawing of a large-diameter, thin-walled hemispherical head plate such as a rocket chamber container.

0002

[Prior Art] Conventionally, in the molding of a large-diameter, thin-walled hemispherical end plate, a sandwich member is constructed and molded using a method in which the upper and lower surfaces of a flat plate material 1 to be molded are formed as shown in FIGS. The sandwich members 2 and 2' are laminated and the surroundings are attached and welded with a flat steel 8 to form a sandwich member, and then the sandwich member is press-formed using a male die 5 and a female die 6, or a material manufacturer manufactures rolled clad steel. In this case, a method is used in which a sandwich material is formed with a chamfered groove, secured by circumferential welding, and then rolled.

0003

[Problems to be Solved by the Invention] Among the conventional techniques mentioned above, in the production of rolled clad steel, sandwich materials are secured by direct welding, and even when rolled, they are sandwiched between rolling rolls and stretched. The welded securing part will not come off. On the other hand, the method of welding and securing the periphery of the sandwich material with flat steel shown in Fig. 3 is effective when the amount of plastic deformation due to elongation and compression is small, but if the amount of plastic deformation becomes large, the flat steel 8 itself may buckle. Wrinkles appear in Figure 3 (a).
) As shown in the right half, there is a problem that the welded part comes off and wrinkles appear on the material 1. In securing a sandwich member when the amount of plastic deformation is large, it is essential to find out what shape the flat steel itself will not buckle, and what shape the groove will prevent the weld from coming off. It is a subject that the invention must interpret.

0004

[Means for Solving the Problems] Therefore, in the method of manufacturing a thin multilayer board of the present invention, in press forming a large diameter, thin hemispherical end plate, a flat plate material to be formed is sandwiched between plate materials that are sufficiently thicker than the upper and lower surfaces, A sandwich member is constructed, and during heating and molding for hot forming, a spacer is inserted into the periphery of the sandwich member, and the periphery of the sandwich member is welded and secured via the spacer, and a male mold and a The present invention is characterized in that the sandwich member is press-molded using a female mold.

[0005]

[Operation] Completely securing the sandwich member by welding is an effective method when the sandwich member is subjected to large plastic deformation. However, when the thickness of the material sandwiched between the sandwich members becomes thick (approximately 20 mm), it becomes impossible to directly weld the sandwich members. Therefore, in the present invention, by inserting a spacer with a shape that does not buckle independently into the inside of the periphery of the sandwich member and welding the sandwich material through the spacer, the sandwich member can be easily formed when the end plate is formed by pressing. , it is possible to form a head plate with high precision and without wrinkles without coming off.

In this case, if the spacer has a square cross-sectional shape, for example, it will not buckle independently even if compressive stress is applied to the spacer, and this will prevent the sandwich materials from coming apart during molding through the spacer. Since the amount of welding can be secured, it is possible to perform the forming process with high precision and without wrinkles as described above.

[0007]

[Example] An embodiment of the present invention will be explained below with reference to the drawings. Figure 1 is an external view of a molded product manufactured by the method of the present invention, and Figures 2 (a) and (b) are cross-sectional explanations showing the method of the present invention. It is a figure and its principal part (A part) enlarged side sectional view.

The molded product according to the present invention shown in FIG. 1 is a hemispherical end plate, and in this embodiment, the radius of the ball is 1250 mm, the plate thickness is 20 mm, and it is a large diameter thin end plate. Because the plate thickness is thin relative to its diameter, if a single plate is drawn, wrinkles will occur around it during forming, making it impossible to form it.

Therefore, in the present invention, as shown in FIG. After constructing a sandwich member by arranging spacers 3 at intervals around the outer periphery of the material 1 and welding the outer peripheries of the spacers 3, this is pressed by a male mold 5 and a female mold 6 during hot forming. Then, a required large-diameter, thin-walled hemispherical end plate 9 as shown in FIG. 1 is integrally molded.

As a result, as shown in the right half of FIG. 2(a), the binding around the sandwich member does not come off during molding, and wrinkles do not occur in the material 1 to be molded.

[0011]

Effects of the Invention As described above, according to the method for manufacturing a thin multilayer board of the present invention, by securing the sandwich member around the sandwich member through the spacer by welding, the sandwich member does not come off during molding. A hemispherical mirror plate can be formed without wrinkles.

[Brief explanation of the drawing]

FIG. 1 is an external view of a molded product manufactured by the method of the present invention.

FIG. 2 shows a method according to an embodiment of the present invention, (a) is a schematic explanatory diagram showing the state before and after molding, and (b) is an enlarged side sectional view of the main part (part A). be.

FIG. 3 is a schematic explanatory diagram of a conventional method, in which (a) is an explanatory diagram of the operation, and (b) is a side sectional view of the main part.

[Explanation of symbols]

1 Flat plate material for forming 2,2' Sandwich material 3 Spacer 4 Welded part 5 Male mold 6 Female mold 9 Molded products

Claims (1)

[Claims] 1. In the press forming of a large-diameter, thin-walled hemispherical end plate, a sandwich member is constructed by sandwiching the flat plate material to be formed between plate materials that are sufficiently thicker than the upper and lower surfaces, and during heating and forming processing for hot forming, A thin multilayer plate characterized in that after a spacer is inserted into the periphery of the sandwich member, the periphery of the sandwich member is welded and secured through the spacer, and the sandwich member is press-molded using a male die and a female die. Production method.