JPS62238033A - Deep drawing method for curved surface shaped body - Google Patents

Abstract

PURPOSE:To prevent the wrinkle of a finished article and to improve the accuracy in the finishing dimension by performing a deep drawing of a thin plate material by a punch in advance, then by performing the bulging via the liquid pressure from the same side. CONSTITUTION:The peripheral edge part of a thin plate stock 1 is supported on a die 2 by a spring 4 and wrinkle pressing plate 3 by arranging the thin plate stock 1 on the die 2. A semi-forming article 1' is then obtd. with the deep drawing of the plate stock 1 by a punch 5. A hydraulic pressure is applied to the deep drawing side of the semi-forming article 1' by fitting a spacer 13 and cover 14 as well as arranging the semi-forming article 1' on a die 12. In this case, the wrinkle of the semi-forming article 1' is eliminated with its elongation deforming by the bulging by the hydraulic pressure. The finishing dimensional accuracy onto the curved surface shaped body of the final finishing article is improved. Consequently the finishing dimensional accuracy can be improved with the prevention of the finishing article wrinkle.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a deep drawing method for forming curved objects such as hemispherical objects and circular objects for manufacturing thin-walled, large-diameter pressure vessels, etc. It is related to.

(Prior Art) It is difficult to form thin, large-diameter hemispherical objects and circular objects, and conventionally, hemispherical objects are made by forming a thin plate (α) into a hemispherical shape as shown in FIG. After developing, cutting and bending a part of the material (b') to form a plurality of materials (b'), the plurality of processed materials (b') are welded (C) to each other to form the shape shown in FIG. It is formed into a hemispherical shape as shown in q, and the large radius part of the circular shape is formed by cutting a thin plate (α□) with a die (d) and a punch (pl) as shown in FIG. After forming the plate with a plate, the plate with a plate holds the formed thin plate material (α/) with clamps &1) and (!2) and rotates it.
Hold the clamp part of H) a-rule (A),! It is formed by spinning with a spinneret spinning roll (i) and then running seven times.

(Problems to be Solved by the Invention) In the conventional method for forming curved objects, whether it is a hemispherical object or a circular object, there are wrinkles in bending and spinning the thin plate material. It is difficult to guarantee the dimensions of the molded product due to the occurrence of wrinkles, and there are problems such as the need for a lot of work for corrective stitching after molding.

(Means for Solving Problems) The present invention provides a deep drawing method for forming curved objects in order to solve the above-mentioned problems. After deep drawing a thin plate material with a punch of the same size or small diameter as the shape, instead of the punch, stretch forming is performed from the same side using hydraulic pressure to eliminate Q1 wrinkles and improve the finishing accuracy of the molded product. This solves the problems mentioned above.

(Function) By deep drawing a thin plate material with a punch of the same size or small diameter as the shape of a curved object, it becomes a semi-formed product of a curved surface shape, and the semi-formed product is stretch-formed by hydraulic pressure to form the same semi-formed product. The entire molded product is subjected to elongation deformation, eliminating wrinkles and resulting in a molded product with improved finished dimensional accuracy.

(Example) Figures 1 to 3 show an example of the method of the present invention. As shown in Figure 1, a thin plate (1) is placed on a die (2), a spring (4) is The peripheral edge of the thin plate material (1) is supported on the die (2) by the presser plate (3), and the thin plate material (11) is deep-drawn using a punch (5) of the same size or small diameter as the final molded product, that is, the curved product. After the semi-molded product (1') is processed into one shape (first step), the semi-molded product (1') is placed on the die α2 as shown in FIG. 13, and apply hydraulic pressure to the semi-formed product (one deep drawing side) through the hydraulic pressure supply hole α9 provided in the lid I, and apply the hydraulic pressure indicated by the arrow to the deep drawing side of the die (121 Air is removed from the hole αG, and one of the semi-formed products (one piece is stretch-molded to form a curved product (
(The illustration shows a hemispherical product) (second step).

A semi-formed product deep-drawn by the punch (5) (
1') When forming, it is necessary to form it a little shallower in order to enable the above-mentioned stretch forming, and when using a punch with the same dimensions as the shape of the curved object, it is necessary to make the drawing depth a little shallower. You can also use a small-diameter punch to add some elongation.

The semi-molded product (1) has one wrinkle as shown in Figure 2, but it has been stretched throughout the semi-molded product (1') due to the stretch forming using hydraulic pressure in the second step. The deformation is applied, wrinkles are eliminated, and the dimensional accuracy of finishing the final product into a curved object is improved.

In order to reduce the amount of wrinkles generated in the first step, a counter hydraulic squeezing method or the like may be employed in the first step.

(Effects of the Invention) In the method of the present invention, as described above, a semi-molded product is obtained by deep drawing of a thin plate material with a punch in the first step, and wrinkles occur in the semi-molded product. In the second step, stretch molding using hydraulic pressure imparts cotton elongation deformation to the entire semi-molded product, eliminating wrinkles and obtaining a curved product (molded product) with excellent finishing and dimensional accuracy.

The deep drawing 9 forming method is a deep drawing process using a punch! The first step and the second step of stretch forming using hydraulic pressure improve machining efficiency and improve finishing accuracy, making correction work almost unnecessary. .

Although the present invention has been described above with reference to embodiments, it goes without saying that the present invention is not limited to such embodiments, and that various design modifications can be made without departing from the spirit of the present invention. .

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of the embodiment of the present invention in a state of deep drawing processing using a punch, Fig. 2 is a perspective view of a semi-formed product, and Fig. 3 is a state of stretch forming by hydraulic pressure in the same embodiment. Longitudinal cross-sectional view, Figure 4 (Al CB) (C) is a conventional molding process diagram of a hemispherical shaped product, and Figures 5 (A) and (B) are conventional molding process diagrams of a large radius part of an end-shaped product. . 1: Thin plate material 1' Half molded product 2, 12: Die 3: Wrinkle press plate 5: Punch 13 Varnish spacer 14: Lid 15
：Hydraulic pressure supply hole 1622 hole Extraction hole Sub-agent Patent attorney Shige Okamoto 2 persons Figure 3 Figure 4

Claims (1)

[Claims] In deep drawing of a curved object, a thin plate material is deep drawn with a punch having the same size or a small diameter as the shape of the curved object, and then, instead of the punch, stretch forming is performed from the same side using hydraulic pressure. Deep drawing method for curved objects.