JP2901822B2 - Method of manufacturing corrugated heat sink - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a corrugated radiator used for a tank of an oil-filled transformer.

[0002]

2. Description of the Related Art In general, a corrugated radiator plate used for a tank of an oil-immersed transformer has a large number of radiating fins formed by bending a sheet material into a corrugated shape. Further, in order to obtain rigidity to withstand the pressure applied to the inner wall of the tank, there is a case where a drawing portion is provided on each flat plate portion of each radiating fin from both sides and the bottom portion is welded to the opposing flat plate portion. Generally, as shown in FIG. 6 and FIG.
a, 2b and bending lower mold 3 to form a heat radiation fin 1a by forming into a wave form, and then using a drawing mold 4 provided on the bending upper mold 2b and the bending lower mold 3 to press and form the drawing portion 1 by pressing.
b, and is spot-welded by a welding device 5 or, as shown in FIG. 8 and FIG. 9, drawn by a press using a drawing die 6 separately provided in a step before bending the sheet material 1 into a waveform. Is formed and then bent into a waveform to form a drawn portion 1
The method of welding the bottom part of b to the opposing flat plate part is used.

[0003]

The former upper folding die 2b
The method of squeezing the sheet material 1 with the drawing die 4 provided in the lower bending die 3 is that the drawing die 4 of the upper bending die 2b, the hole of the lower bending die 3, and the welding device 5 must be at the same position. If it cannot be drawn. Therefore, restrictions are imposed by the height dimension of the radiation fin 1a.

[0004] In the latter method, in which the sheet material 1 is drawn into a corrugated shape by a press in the pre-process, there is no problem in the former case, but other processes must be stopped during the drawing process. However, there is a drawback that the manufacturing process of the corrugated heatsink is lengthened and expensive.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of manufacturing a corrugated radiator plate capable of efficiently and inexpensively processing a large number of corrugated fins having increased mechanical strength. is there.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a method of manufacturing a corrugated heat radiating plate for forming a large number of radiating fins by bending a sheet material into a wave form. It is characterized in that after drawing by a roller, the radiation fins are formed by bending into a waveform, and the drawn portions of the respective radiation fins are fixed by welding. Also, a step of forming a drawing portion at a portion where the sheet material is bent into the next waveform is performed simultaneously with the step of bending the sheet material into the waveform.

[0007]

According to the above-mentioned means, since the drawing portion is formed by the roller in the step before the step of continuously bending the sheet material into a waveform, the sheet material can be moved. Therefore, it is not necessary to stop the movement of the sheet material at the time of forming the drawing portion, so that the manufacturing time can be reduced. Also, by simultaneously performing the process of continuously bending the sheet material in a corrugated shape and the process of forming the drawn portion, there is no time interference between the drawing process and the corrugated forming as in the past, and the continuous line Thus, an inexpensive corrugated radiator plate which can be manufactured in a short time can be obtained.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. 1 and 2, a fixed amount of the sheet material 11 is sent from an NC device 12 between a pair of upper and lower squeezing rollers 7a and 7c. After the sheet material 11 is formed with a drawing portion described later by the drawing rollers 7a and 7b, the upper folding die 8 is formed.
a, 8b, a bending lower die 9 and a holding die 10 are sent to a bending device, which is bent into a waveform by the bending device to form a radiation fin 11a. A welding device 13 is incorporated in the upper bending die 8b and the lower bending die 9, and the opposed drawing portions 11b formed on the radiation fins 11a are formed.
Is spot-welded to improve the mechanical strength of the radiation fin 11a against bulging deformation.

A pair of upper and lower aperture rollers 7a and 7b are shown in FIG.
As shown in (a), when the moving sheet material 11 reaches a predetermined position, the upper drawing roller 7a descends,
By pressing and rotating with respect to the sheet material b, a drawn portion 11b is formed in the sheet material 11 along the moving direction thereof. After the drawn portion 11b is formed to a predetermined length, FIG.
As shown in (b), the upper drawing roller 7a is lifted to cancel the formation of the drawing portion 11b, and the sheet material 11 is sent to the step of forming the radiation fins 11a.

As shown in FIG. 4, the length of the drawn portion 11b is the height H of the radiation fin 11a to be bent next.
Is formed according to the height dimension H of the radiation fin 11a.
In this case, the upper draw roller 7a can be formed at any position and length by moving the upper draw roller 7a up and down.

Also, by increasing or decreasing the number of the squeezing rollers 7a, 7b to increase or decrease the number of squeezed portions, it is possible to obtain the required rigidity against an increase in the internal pressure required for the transformer tank.

In the folding apparatus, a sheet material 11 is fed between the upper folding dies 8a and 8b, the holding die 10 and the lower folding die 9 at the fixed position, and is folded as shown in FIG. The lower die 9 pushes up the top of the heat radiation fin of the sheet material 11 and bends the both sides so that the drawn portions 11b formed in the previous step face each other to form the heat radiation fin. During the process of forming the radiation fins 11a, the process of forming the next drawn portion 11b can be performed simultaneously.

FIGS. 1 and 2 show that the radiation fin 11a is bent in the bending device and the radiation fin 11a is
Shows a state in which the drawn portion 11b is welded, and the above-described steps are repeated to form a large number of radiating fins 11a continuously.

In this manner, the squeezing roller 7 is provided in a process prior to the process of continuously bending the sheet material 11 in a waveform.
Since the drawn portion 11b is formed by a and 7b, the sheet material 11 can be moved in the step of forming the drawn portion 11b. Therefore, it is not necessary to stop the movement of the sheet material 11 at the time of forming the drawing portion 11a, so that the manufacturing time can be reduced. Further, by simultaneously performing the step of continuously bending the sheet material 11 in a waveform and the step of forming the next-stage drawing portion 11b, there is no time interference between the drawing and the waveform forming as in the related art. In addition, an inexpensive corrugated radiator plate which can be manufactured continuously and in a short time on a consistent production line can be obtained.

[0015]

According to the method for manufacturing a corrugated radiator plate of the present invention, a drawn portion is formed on a sheet material by a roller and then bent into a corrugated shape, so that the productivity is high.
The effect is obtained that the rigid radiating fin can be efficiently formed without being restricted by the radiating fin height.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing an embodiment of an apparatus employing the method of the present invention.

FIG. 2 is a schematic plan view of FIG.

3A is a schematic front view showing a state in which a drawn portion is formed by a drawing roller, and FIG. 3B is a schematic front view showing a state in which the formation of the drawn portion is released;

FIG. 4 is a perspective view of a radiation fin formed by the method of the present invention.

FIG. 5 is a schematic side view showing a state in which a sheet material is bent by the method of the present invention.

FIG. 6 is a schematic side view showing a conventional method of manufacturing a corrugated heatsink.

FIG. 7 is a perspective view of a radiation fin formed by the manufacturing method of FIG. 6;

FIG. 8 is a schematic side view showing another conventional method for manufacturing a corrugated heatsink.

FIG. 9 is a schematic plan view of FIG. 8;

[Explanation of symbols]

1, 11 are sheet materials, 1a and 11a are radiation fins, 1
b, 11b are drawing parts, 5, 13 are welding devices, 7a,
7b is upper and lower squeezing rollers, 8a and 8b are upper folding dies, 9
Indicates a folded lower mold, and 10 indicates a holding mold.

Claims (2)

(57) [Claims] 1. A method for manufacturing a corrugated radiator plate, comprising forming a large number of radiating fins by bending a sheet material into a corrugated shape, wherein when the sheet material is in a flat state, a flat portion of the sheet material is subjected to drawing by a roller. A heat radiation fin formed by bending the heat radiation fin, and a drawn portion of each heat radiation fin is welded and fixed. 2. The method according to claim 1, wherein a step of forming a drawn portion in a portion where the sheet material is bent into the next waveform is performed simultaneously with the step of bending the sheet material into a waveform.