JPS6359764B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bending method suitable for bending a metal plate so that it has a certain radius of curvature on substantially one surface thereof.

Conventionally, for example, the rotating drum of a clothes dryer has a first
It has a shape as shown in the figures and FIG. 2, and more specifically, a cylindrical drum body 1, a donut-shaped drum front frame 3 having a clothes input port 2 fixed to the front end of the drum body 1, It consists of a disk-shaped drum rear frame 4 fixed to the rear end of the drum body 1.

Here, the processing procedure for the drum front frame 3 will be described. As shown in FIG. 3, first, a rectangular metal plate 5 is obtained, and a drum front frame 3 is punched out from it.
3a shows a bent flange at the opening edge of the clothes input port 2, and 3b shows a bent flange at the peripheral edge of the drum front frame 3. When such punching is performed, the central part of the metal plate 5 corresponding to the clothes input port 2 and the peripheral part of the metal plate 5 located on the outer peripheral side of the peripheral bending flange 3b, that is, the hatched area A in FIG. and B are not used and are wasted.

Furthermore, since the above-mentioned punching is performed while manipulating the metal plate 5 having a large surface area, it is difficult to perform the punching process manually, and if automated, the size of the apparatus must be increased. Moreover, an extremely large cutting force is required for pulling out, and high reliability in terms of strength and strength of the device, etc., is required.

The above-mentioned problems do not only occur when obtaining a drum front frame, but also when attempting to produce a donut-shaped or partially arc-shaped part in general metal plate processing. A problem similar to that described above arises.

The present invention has been made in view of the above-mentioned conventional problems. When a metal plate is formed into a donut shape or a partially circular arc shape, the metal plate is bent to have a certain radius of curvature on substantially the same plane. Examples thereof will be described below with reference to the accompanying drawings.

As shown in FIG. 4, a strip-shaped metal plate 6, for example, a steel plate, has a plurality of rolled portions 7 intermittently formed in a direction substantially orthogonal to its length. The amount of rolling is changed regularly from one end A to the other end B. As a result, the amount of elongation of the metal plate 6 corresponding to the amount of rolling changes regularly, and an arcuate portion 8 having a certain radius of curvature centered on the point O is formed in the metal plate 6.

FIG. 5 shows the metal plate 6 after processing, which has a donut shape in which the arcuate portions 8 are continuously connected, and FIG. A processed metal plate 6 having a rectangular shape is shown.

Next, a specific example of the rolling section 7 will be explained. In the case shown in FIG. 7, the width of the rolled part 7 indicated by diagonal lines gradually increases regularly from one end A to the other end B. Specifically, the width l of one end A and the width l of the other end There is a relationship of l'>l with the width l' of the edge. Reference numeral 9 denotes a groove formed as a result of forming the rolled portion 7, and its width, size, etc. correspond to the rolled portion 7. In order to form the rolled portion 7 having the above relationship l'>l, a pressing member (not shown) whose tip shape has dimensional accuracy corresponding to the relationship l'>l is pressed against the metal plate 6. , the metal plate 6 may be plastically deformed to form the grooves 9.

Due to the above-mentioned relationship l'>l, the amount of rolling in the length direction of the metal plate 6 is different between one end A side and the other end B side, and an arcuate portion 8 is formed.

In the case shown in FIG. 8, the width of the rolled part 7 indicated by diagonal lines is the same, but the thickness becomes thinner regularly from one end A to the other end B. Thickness t on one end A and thickness t on the other end B
There is a relationship between t' and t'<t. As a result, grooves 9 are formed in the same manner as in FIG. and,
In order to form the rolled portion 7 having the relationship t'<t, a press having a tip shape corresponding to the depth of the groove 9 when the thickness t' and t are subtracted from the thickness of the metal plate 6 is used. It is sufficient to apply plastic deformation to the metal plate 6 using a member.

As a result, the amount of rolling in the length direction of the metal plate 6 is different between one end A side and the other end B side, and an arcuate portion 8 is formed.

As described above, the rolled portion 7 is formed in the metal plate 6 in a direction substantially perpendicular to its length direction, and the rolled portion 7 is rolled in a regular manner from one end A to the other end B. By changing the metal plate 6 to a belt shape, an arcuate portion 8 can be formed on the metal plate 6, and processing into a donut shape as shown in FIG. 5 or a rectangular shape as shown in FIG. It can be carried out without having to Moreover, since the rolling amount of the rolling section 7 is changed, the processing device may have a relatively small pressing member and apply a small pressing force to this pressing member, which reduces the size of the device and improves its strength. It is possible to ensure reliability in terms of aspects. Further, as the metal plate 6, one having the required surface area may be prepared, and the metal plate 6 can be easily handled.

Further, according to the method shown in FIGS. 7 and 8 as specific examples for changing the amount of rolling in the rolling section 7, a reliable change in the amount of rolling can be expected, and
It is easy to implement because it is only necessary to slightly change the shape of the pressing member.

Furthermore, by combining the methods shown in FIGS. 7 and 8, it is possible to form a rolled portion that becomes wider and thinner from one end A to the other end B. Accordingly, the rolling amount can be increased compared to the cases shown in FIGS. 7 and 8. Therefore, if you want to obtain the same amount of rolling as shown in FIGS. The degree of pressing of the member can be reduced compared to the case of the embodiment.

In the present invention, the term "regularly changing the amount of rolling" means that the amount of rolling does not increase or decrease repeatedly from one end to the other; for example, when the width or thickness of the rolled part increases or decreases, This means not repeating.

As described above, according to the metal plate bending method of the present invention, a metal plate can be bent into an arc shape with a certain radius of curvature on substantially the same surface without wasting material. It is extremely useful for bending into a donut shape to obtain the front frame of a drum, or bending it into an arc shape at an appropriate location to obtain the frame of various casings, etc. Moreover, it is easy to handle the metal plate and is easy to implement. The structure of the processing equipment and the like can be easily and inexpensively obtained.

In addition, by forming rolling parts intermittently,
Pressure can be applied only locally, processing can be performed with a small force, and thick and thin parts are formed intermittently, and the thick parts act as reinforcement to improve strength. Sufficient strength can be ensured even for items that require caulking on the outer periphery, such as drums.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view showing a conventional rotary drum for a clothes dryer, Fig. 2 is a longitudinal cross-sectional view thereof, Fig. 3 is a plan view showing the processed state of the front frame of the drum, and Fig. 4 is a perspective view of the rotary drum of the present invention. 5 and 6 are plan views showing the form after the processing, FIG. 7 shows a specific example of the processing, and FIG. Figure b is a sectional view taken along line X-X' of a.
FIG. 8 similarly shows a specific example, and FIG. 8 a is a plan view;
Figure b is a sectional view taken along line Y-Y' of a. 6...Metal plate, 7...Rolling section.

Claims (1)

[Claims] 1. Rolled portions are formed intermittently on a metal plate in a direction substantially perpendicular to its length, and the rolled portions are rolled in a regular manner from one end to the other. A method of bending metal plates that is characterized by changing the shape. 2. A method for bending a metal plate according to claim 1, characterized in that a rolled portion is formed whose width changes regularly from one end to the other end. 3. A method of bending a metal plate according to claim 1, characterized in that a rolled portion is formed whose thickness changes regularly from one end to the other end. 4. A method for bending a metal plate according to claim 1, characterized in that a rolled portion is formed that becomes wider and thinner from one end to the other end.