JPS61199528A - Production of elbow bending metal die - Google Patents

Abstract

PURPOSE:To reduce the production cost of metal die by bending with pressing the upper and lower metal dies as well as pinching the base metal with two pieces of auxiliary materials, then by fitting the auxiliary material to the upper and lower metal dies respectively by welding, etc. CONSTITUTION:A base metal is pinched by the auxiliary materials 1, 2 for the upper and lower metal dies which are cut in the similar shape to that of the base metal and bent with pushing by the upper and lower metal dies with the sandwiched shape as it is. The bent auxiliary materials 1, 2 are respectively fitted to metal dies 4, 5 by of welding, etc. A half type elbow is thereafter produced by bending the base metal with the state of fitting the auxiliary materials 1, 2 to the metal dies 4, 5. The bending is accordingly applied by the sandwich method for the initial one set only but the auxiliary materials 1, 2 remain to use for the upper and lower dies 4, 5. The auxiliary materials 1, 2 come into close contact with the metal dies 4, 5 and can be therefore used as the member of the metal dies 4, 5 efficiently. The production cost of the metal dies can be reduced accordingly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing an elbow bending mold that can be used for large welded elbows of boilers and the like.

(Prior art) When bending conventional welded elbows, if the dimensions of the molds are different, shrink fitting (Figures 4 and 5) is used to match the dimensions correctly and make effective use of the existing molds. but,
Considering the degree of adhesion to the mold for the shrink fit method, the plate thickness is 12
mm is the limit. Therefore, either a new mold is made or a sandwich bending process is used, but the sandwich method for mass production has the drawback of requiring auxiliary materials 6 (discarded after use) and wasting labor costs.

(Problems to be Solved by the Invention) The present invention attempts to solve the problems that conventional elbow bending requires unnecessary supplementary materials and labor costs.

(Means and effects for solving the problem) For this reason, the present invention provides a method for manufacturing an elbow bending mold in which two halves are welded together. The same base material is sandwiched between two auxiliary materials,
These are simultaneously pressed and bent using upper and lower molds, and then the bent auxiliary materials are attached to the upper and lower molds by welding or the like.

(Example) Examples of the present invention will be described below with reference to the drawings. FIGS. 1 to 3 show examples of the present invention. Now, in Figures 1 to 3, 1. The elbow is manufactured by welding two halves together, and the half part is unfolded, the shape is marked on the steel plate, and the base material 3 is made by cutting. After that, it is pressed and bent using an upper mold 4 and a lower mold 5.

At this time, it is sufficient that the gap when the upper die 4 and the lower die 5 are combined is the thickness of the base material 3, but if this gap is large, it is necessary to change the die to match the thickness of the base material 3.

In order to eliminate this gap, auxiliary material 1 is added to the upper mold 4 and lower mold 5.
and 2, but this method is as follows: (1) The upper mold auxiliary material 1 and the lower mold auxiliary material 2, which are cut into the same shape as the base material 3 as shown in Fig. 1, are attached to the base material. 3 and press and bend the sandwich shape using upper and lower molds.

(2) The auxiliary materials 1 and 2, which were first bent, are attached to the respective molds 4 and 5 as shown in FIGS. 2 and 3 (by welding).

(3) After that, supplementary materials 1 and 2 are added to each mold 4.
and 5, only the base material 3 is bent to produce a half-split elbow.

That is, only the first set is bent by the sandwich method. At this time, the auxiliary materials 1 and 2 bent at the same time remain for the upper mold and the lower mold. Add this to the upper and lower molds 4.5
weld to each.

(Effects of the Invention) Since the present invention is configured as explained in detail above,
When bending is performed using the sandwich method, the supplementary material is the top,
Since it adheres closely to the lower mold, it can be efficiently obtained as a mold member. Therefore, according to the present invention, the manufacturing cost of the mold is low, and unlike the conventional method, it does not take much time for development, cutting, and welding, and the mold can be manufactured efficiently.

[Brief explanation of drawings]

1 to 3 show embodiments of the present invention, FIG. 1 is a perspective view showing a material for sandwich bending, FIG. 2 is a perspective view of the upper mold for attaching auxiliary materials, and FIG. Fig. 4 is a plan view of the upper mold (lower mold) in which auxiliary material is expanded and marked and cut and shrink-fitted in conventional elbow bending processing, and Fig. 5 is a front view of the same. It is. Explanation of the main parts of the figures 1.2・-Supplementary material 3・・・−Base material 4・・Upper mold 5・−Lower mold Patent Applicant Mitsubishi Heavy Industries, Ltd. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In the method of manufacturing an elbow bending mold, which involves welding two halves together, the base material is sandwiched between two auxiliary materials cut in the same shape as the base material for bending. A method for manufacturing an elbow bending mold, which comprises simultaneously pressing and bending the material using upper and lower molds, and then attaching the bent auxiliary material to each of the upper and lower molds by welding or the like.