JPH03268823A - Method for producing a part of nonstretchable from from thin metal plate material and part produced by said method - Google Patents

Abstract

PURPOSE: To make it possible to produce part of an unstretchable shaped body from a sheet metal blank by determining a change in volume by a difference between the basic volume of a planar metallic sheet and the basic volume corrected by the deformation of the thin metal blank. CONSTITUTION: Holes 60, 70 formed in a thin region have an adaptable geometrical shape, such as, for example, an elliptic shape, and are so distributed as to increase toward the flanged ends from a base part in terms of a number or surface area. If an angle region 40 has two ridges delineating an inclined side part 41, the angle region 40 has two hole circuits 60 on the respective side of this inclined side part 41, in other words, in the thin region. Such hole circuits 60, 70 are capable of removing the material of the prescribed amt. corresponding to the excess volume before the deformation. In such a case, the empty spaces formed by the holes 60, 70 are eliminated as the sheet metal blank 10 is formed, by which the deformation of the non-controlled state is eliminated and the maintaining of approximately the specified thickness of the sheet metal blank is made possible.

Description

[Detailed description of the invention]

0001

[Industrial application field]

The present invention relates to a method for manufacturing parts of non-stretchable shapes from sheet metal stock, in particular for forming corner regions of flanged edges. [0002] The subject matter of the present invention is also part of the non-stretchable shapes formed by such a method. [0003]

[Conventional technology]

In the traditional method of forming sheet metal, thin sheet metal material is
The peripheral portion is held and its central portion is acted upon by the lowering or raising movement of the punch, which progressively deforms the material and flanges the peripheral portion. [0004] In this method, the peripheral edge portion is subjected to a thinning action to reduce the diameter of the peripheral edge portion from the outside. In order to prevent the formation of wrinkles, especially in the corner areas, the pressure applied to the material must be increased, resulting in an increase in the tensile forces exerted by the central part. This method can be applied to thin sheet materials made of malleable materials. [0005]

[Problem to be solved by the invention]

However, such known methods are useful for certain forming operations of materials that do not exhibit sufficient elongation, in particular for very thin sheet metal materials made of materials with low elongation, or for the production of wrinkles due to geometrical shapes. It cannot be applied if the occurrence is unacceptable. [0006] To prevent the formation of wrinkles, a series of ribs or notches are formed in the flanged edge and the number, distribution, size and shape of the ribs or notches are adjusted to prevent excess length of the edge during the flanging process. For example, increasing the length of a flanged edge of a non-stretchable shape positioned within a square head region can be compensated for by being able to absorb the stiffness.

Another known method of forming sheet metal stock is to heat the sheet metal stock to make it more ductile and facilitate deformation with lower forces. However, heating has the disadvantage that it oxidizes the resulting parts and requires a cleaning step. [0008] Neither of these techniques is particularly satisfactory when forming high strength metals, and the ribs or notches that are formed adversely affect the stiffness of the part that is formed. It is an object of the invention to cold-manufacture parts of non-stretchable shapes from thin-walled sheet metal materials, avoiding the above-mentioned disadvantages, for example thermal distortions, or when forming metal sheets with low ductility. The goal is to solve the problems of SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for manufacturing a part of a stretchable profile from a thin metal material, in particular for forming a flanged edge. For each surface element of the thin metal material and for a given wall thickness, find the basic volume of the thin metal sheet, and calculate the change in volume by calculating the basic volume of the flat metal sheet and the deformation of the thin metal material. by modifying the final part of the sheet metal material in the thinner region by adding at least one circuit of holes to the final shape of the stretchable body. Corresponding to the change in volume, remove a certain amount of material so that a final part of non-stretchable material is obtained, select the number, distribution, dimensions and shape of the hole circuits, and convert said hole circuits into thin areas. It is an object of the present invention to provide a method characterized in that the final part of the non-stretchable part is formed by forming a sheet metal material into a thin sheet metal material and deforming the sheet metal material in a press.

According to another feature of the invention, a hole portion is formed in the sheet metal stock in each region of the flanged edge. [0011] According to yet another feature of the invention, hole portions are formed in the sheet metal material between regions at predetermined positions and locations where the length of the edge increases due to flanging of the edge. Ru. [0012] The subject matter of the present invention is also part of the non-stretchable shapes formed by the above method [0013] The present invention emerges from the following detailed description, given by way of example only with reference to the accompanying drawings. You will be able to understand it better. [0014] In the accompanying drawings it can be seen that the desired shape is a generally triangular shape obtained by folding the edge 2.3 back. [0015] By folding the edge 2.3 backwards, the material increases in the thin-walled areas, especially in the square head area 4, from the corner 5 to the edge 6, so that the sheet metal forming the flanged edge is subjected to compressive forces. It is intended to be received. Such compressive forces cause wrinkles 7 due to bending of excess material due to molding of the part. [0016] This known method is useful when it is desired to prevent compressive stress forces acting on a flanged edge from being transmitted to the center of the part, especially in the case of ultra-thin wall thickness sheet metal, or when geometric It is unsatisfactory if the shape does not allow the formation of wrinkles. [0017] In order to prevent the formation of these wrinkles, as shown in FIG.
0,40a) in particular in the corner region 30 of the flanged edge 20.30 of the sheet metal stock 10. [0018] As shown in FIG. 3, in order to obtain a non-stretchable shape from the thin sheet metal material 10, the basic elements 21 are arranged in each defining plane (Δθ, Δh) and in a predetermined thin sheet. Calculate for wall thickness. [0019] After folding the sheet metal material containing the volume 21 backwards and modifying the final part into the final shape, the excess volume due to this simulated deformation is calculated by calculating the corresponding volume 22. can be found by differentiation. [00201 In order to prevent wrinkles 7 caused by excess material in the thin-walled region, six circuits (60, 70) are defined, and before deformation, a certain amount corresponding to the excess volume thus determined is defined. (Figure 4).

As shown in FIG. 2, the six circuits 6 include a central area 50 corresponding to the right angle that defines the corner area 40, and each side of the central area 50 has a transition area 51a51b. , central hole area 50 and solid flanged edge 20.3
Ensure the connection between 0 and 0. [0022] The holes 60 are distributed as a function of their number, distribution, and geometry. [0023] Six circuits 70 are also shown in FIG. 2, and are distributed to accommodate the extra length of the flanged edge, e.g., in locations where ribs or notches may be placed. has been done. For example, while forming the sheet metal material 10 by a press, the compressive force generated, for example, in the press deforms the sheet metal material. [0024] The empty space formed by the holes (60, 70) is eliminated as the edges of the holes approach each other, thereby preventing uncontrolled deformation while simultaneously increasing the It becomes possible to maintain a substantially constant wall thickness and ensure relative continuity of the material. [0025] The holes (60, 70) formed in the thin-walled region have a matching geometric shape, such as an ellipse or a polygon, and extend in number or surface area from the base to the end of the flanged edge. It is distributed so that it increases in the direction of the body.

Corner regions 40 have sloped sides 41 between them (FIGS. 5 and 6)
, the corner area 40 is provided with two six-circuits 60 on each side of the sloping side 41, in other words in the flash area. [0027] Each of the six circuits 60 has the same shape as shown in FIG. 2 for each region with one ridge;
The zeros are distributed as a function of their number, size and geometry. Six circuits (60, 70) are thus defined and a predetermined amount of material corresponding to the excess volume thus defined can be removed before deformation. [0028] In this case, the empty spaces formed by the holes (60, 70) are eliminated as the sheet metal material 10 is formed, thereby eliminating uncontrolled deformation and maintaining a substantially constant state of the sheet metal material. It becomes possible to maintain the wall thickness. In particular, the method according to the invention makes it possible to: [0029] Preventing the formation of wrinkles during molding. [00301 During molding, deformation forces are reduced, especially when the material forming the sheet metal material has high strength. [0031] Preventing or reducing internal stress due to molding. [0032] Avoiding notches in the sheet metal stock and providing continuous flanged edges improves rigidity. [0033] A predetermined geometric shape of substantially constant wall thickness can be formed.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of a portion of a non-stretchable profile formed from a sheet metal material by a method known from the prior art;

FIG. 2 is a partial plan view of a sheet metal blank for carrying out the method according to the invention, in which a hole is formed in each region and another hole region is formed in the flanged edge;

FIG. 3 is a partial perspective view of an angular portion with a flanged edge of a non-stretchable shape showing displacement of a component of a given volume;

FIG. 4 is a perspective view of a part of a non-stretchable shaped body obtained by the method of the invention.

FIG. 5 shows a partial plan view of a sheet metal blank with a corner region with two ridges provided with holes for realizing the method according to the invention;

6 is an angular partial perspective view of the sheet metal blank according to FIG. 5, with the flanged edge having a non-stretchable shape; FIG. [Explanation of symbols] 2.3 Edge 4 Corner region 5 Corner 6 Edge 7 Wrinkle 10 Thin metal material 20, Francie dimension resistance 21.22 Volume 30 Flanged edge 40.4 Oa Thin plate thickness region 41 Incline Side portion 50 Central region 51a, 51b Transition region 60.70 Hole circuit

[Document person]

drawing [Figure 1] [Figure 2]

[Figure 31 [Figure 41 [Figure 5] [Figure 6]

Claims (8)

[Claims] 1. A method for producing a part of a non-stretchable shape from a sheet metal material (10) to form a flanged edge (20, 30), each surface of the thin metal material to be formed. The basic volume of the thin metal plate is determined for each element and for a given wall thickness, and the change in volume is corrected by the basic volume of the flat thin metal plate and the deformation of the thin metal material (10). defining a circuit of at least one hole (60, 70) and forming a thin metal material (
10) corresponding to the change in volume associated with modifying the initial shape of the hole (60, 70), removing a certain amount of material so as to obtain a final portion of non-stretchable material;
selecting the number, distribution, dimensions and shape of the holes (
60, 70) on a thin sheet metal material in a thin region; and deforming the sheet metal material (10) in a press to form the final portion of the non-stretchable portion. How to do it. 2. The method of claim 1, wherein the hole (60) is located at a flanged edge (20, 30) on the sheet metal material (10).
A method characterized in that it is formed in a corner region (40) of. 3. The method of claim 1, wherein a hole (70) is formed in the sheet metal material at a predetermined position and location where the length of the flanged edge increases due to edge flanging. A method characterized by: 4. A non-stretchable shaped part formed by the method according to any one of claims 1 to 3. 5. A non-stretchable shaped part according to claim 4, characterized in that the thin-walled region is provided with holes (60, 70) of different shapes. 6. A non-stretchable shaped part according to claim 5, characterized in that the holes (60, 70) have an elliptical shape. 7. The non-stretchable shaped part according to claim 5, characterized in that the holes (60, 70) have a polygonal shape. 8. A non-stretchable shaped part according to any one of claims 4 to 7, wherein the holes (60, 70) increase from the base toward the ends of the flanged edges (20, 30). Parts characterized by being distributed in different numbers and in different shapes.