JPH11340105A - Explosion-proof container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make thin-wall explosion-proof grooves easily formable as an explosion-proof valve on the bottom plate of an explosion-proof container, even when the thickness of the bottom plate is increased by forming the surrounding section of the grooves thinner in thickness than the wall of the container. SOLUTION: Two thin-wall explosion-proof grooves 3 engraved into the bottom 2 of a can have widths of, for example, 0.5 mm and the bottom sections of the grooves 3 have wall thicknesses of, for example, 0.25 mm. The grooves 3 are engraved into the bottom 2 in a separate process after the can is formed. The grooves 3 are formed so that their intersection 4 may be positioned to nearly the center of the bottom 2. A thin wall section 5 provided around the grooves 3 with a width of, for example, 5 mm has a wall thickness of 0.6 mm. Thus, the surrounding section having a width of, for example, <=20 mm of the grooves 3 is formed to have a wall thickness of, for example, 0.3-0.8 mm which is thinner than that of the can. In addition, the thin wall section around the grooves 3 is formed in the same process when the can is formed by impact molding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an explosion-proof structure for a container, and more particularly to an explosion-proof container provided with a thin explosion-proof groove on the side or bottom of the container.

[0002]

2. Description of the Related Art A container provided with an explosion-proof mechanism for preventing the internal pressure of the container from being ruptured due to the rising pressure. The explosion-proof mechanism has a thin-walled groove on the side or bottom surface. Products that use containers include, for example, condenser cans. Generally, a cylindrical bottomed cylindrical can is used as the capacitor can.

When the internal pressure of the cylindrical can increases due to abnormal operation of the capacitor, the shape deformation of the can is extremely small even if the internal pressure of the can increases because the side surface is formed in a circular shape. On the other hand, the bottom of the can is flat, and the fixed beam at both ends is deformed in response to an increase in the internal pressure of the can.

Since the explosion-proof valve is opened by utilizing this deformation of the member, the bottom of the can, which has a large deformation, is suitable as a groove installation site. For this reason, explosion-proof thin-walled grooves are generally provided at the bottom of the can. Examples of the shape of the thin groove include, for example, Japanese Utility Model Publication No. 62-33309, Japanese Utility Model Publication No. 5-21861,
An example is found in Japanese Utility Model Publication No. 6-9482.

In Japanese Utility Model Publication No. Sho 62-3309, each groove is formed on the bottom of the case from the outer periphery toward the center.
The groove is formed so as to form an angle of degree and concentrate at one point at the center.

[0006] When the internal pressure of the can is increased, the thin groove formed in this manner is deformed outwardly around the intersection of the grooves, which is provided substantially at the center of the bottom of the can. When the deformation of the can reaches the critical point, a crack starts at the intersection of the groove on the bottom of the can, and the crack spreads to the four grooves to release the pressure in the can. At this time, the opening pressure is determined by the thickness of the thin groove. Usually, the thickness of the thin groove is formed to a thickness of 0.1 to 0.4 mm.

The thin groove is press-formed by an engraving die after the can is made. However, because of the press molding, the can meat at the portion where the groove is engraved is pushed to the periphery of the groove, deforming the shape of the periphery and causing internal strain in the can bottom plate. If the plate thickness is approximately 0.4 to 0.8 mm, this deformation and internal strain are absorbed in the member, and there is no problem such as deformation of the can bottom shape.

[0008] However, when the plate thickness is about 0.8 mm or more, the amount of protrusions of the mold that penetrates into the bottom of the can increases. Also, as the plate thickness increases, the engraving convex width of the press die that forms the thin part needs to be wider than that of the thin plate thickness in order to ensure strength, so the volume of the can meat eliminated by the engraving die also increases However, there has been a problem that the deformation and distortion of the can bottom plate are increased, and it is difficult to form a thin groove.

[0009]

SUMMARY OF THE INVENTION An object of the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an explosion-proof valve that can be easily used even if the thickness of the bottom plate of a container is increased. It is an object of the present invention to provide an explosion-proof container that enables the installation of a thin groove.

[0010]

In order to achieve the above object, in the explosion-proof case according to the present invention, the peripheral portion (20 mm or less from the groove) of the explosion-proof thin groove is made thinner than the thickness of the container. It was molded to a thickness (0.3-0.8 mm).

The thin portion around the explosion-proof thin groove was formed by impact molding in the same process as can molding.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the container according to the present invention will be described in detail with reference to examples.

FIG. 1 is a view of the bottom of a can of an explosion-proof container engraved with a thin groove functioning as an explosion-proof valve according to the present invention, as viewed from the outside of the can, and FIG. 2 is a view of the can from the inside. FIG. 3 is a diagram showing a section of an engraved portion when a thin explosion-proof groove is engraved on the bottom of a thin plate, and FIG. 4 is a diagram showing a section of an engraved portion when a thin-wall explosion-proof groove is engraved on the bottom of a thick plate. FIG. FIG.
FIG. 2 is a diagram showing a cross section of the thin groove portion of FIG. 1, and is a diagram showing a cross section of a bottom portion of a can in which a thin portion is formed around the thin explosion-proof groove.

In FIG. 1, the diameter of the can is 54 mm,
The thickness of the can is 0.8 mm on the side 1 of the can and 1.0 mm on the bottom 2 of the can. The material of the can is aluminum in this example.
70-O is used. Besides aluminum cans, A1
050, A1060, A1080, A1090, A1N3
0, A3003, A3005, A3105, A320
3, A3004 and A3104 are used. In this example, the can can is made by an impact molding method. In the case of this processing method, as the material of aluminum, A1000 series and its O material or A material of A3003 are suitable. As a characteristic of the impact molding, generally, the moldability is better when the thickness of the can is thicker at the bottom of the can than at the side of the can.

Reference numeral 3 denotes an explosion-proof thin groove engraved on the bottom of the can. The width of the groove is 0.5 mm, and the thickness of the groove bottom is 0.25 mm. After the can is formed, the groove is engraved by an engraving die as a separate step. Two grooves 3 are provided, and their intersection is set substantially at the center of the bottom of the can. In FIG. 2, reference numeral 5 denotes a thin portion provided with a width of 5 mm around the position of the groove 3, and the thickness is set to 0.6 mm.

The can of FIG. 3 has a thickness of 0.4 mm on the side of the can,
The bottom thickness of the can is 0.4 mm, and the explosion-proof thin groove 6 has a groove width of 0.4 mm.
The thickness at the bottom of the groove is 0.2 mm.

The can of FIG. 4 has a side thickness of 0.8 mm, a bottom thickness of 1.0 mm, an explosion-proof thin groove 7 having a width of 0.7 mm and a bottom thickness of 0.2 mm. Millimeters.

FIG. 5 is a cross section of the groove shown in FIG. 10 in the figure
Is a thin part formed at the same time when the can is formed by impact molding. Since 10 is molded at the same time as the impact molding of the can, a shape symmetrical with respect to the center of the can bottom is desirable so as not to disturb the flow during the molding of the can material.

One of the features of the impact molding is that if the thickness of the bottom of the can is substantially symmetrical with respect to the center of the can bottom, it can be molded integrally with the can at the time of molding, so that there is an advantage that internal distortion due to molding does not remain. . When this shape (for example, the shape shown in FIG. 1) is manufactured by press molding, internal stress remains in the thickness change portion and the can is likely to be deformed. Therefore, impact molding is more suitable for molding a thin portion according to the present invention.

Numeral 9 denotes an explosion-proof thin-walled part having a groove width of 0.5 mm.
The thickness of the lower part of the groove is 0.2 mm.

In FIG. 3, when engraving the explosion-proof thin-walled portion 6 after forming the can, the canned portion of the engraved portion is pushed to the periphery of the groove 6, but the plate thickness of the can bottom is 0.4 mm. It may be relatively thin, the volume of the pressed meat is small, and the bottom of the can is not deformed by engraving.

However, when the thickness of the bottom of the can becomes 1.0 mm as in the case of the can of FIG. 4, the volume of the can meat at the bottom of the can which is pushed away by engraving of the press die 8 is large, and the can protruded around the groove. The meat causes deformation of the can bottom. For this reason, there is a problem that engraving of the bottom of the can cannot be appropriately performed for a can having a large thickness.

FIG. 5 shows a thin portion 10 having a width of 5 mm and a thickness of 0.6 mm from the inside of the can, formed so as to sandwich the explosion-proof thin groove on the bottom surface of the can of FIG.

In this embodiment, the thickness is set to 0.6 mm. However, the thickness of the thin portion 10 is in the range of 0.3 mm to 1.0 mm, and the engraving deformation distortion does not occur for the material and thickness of the raw can. The optimal thickness is selected.

The explosion-proof thin groove 9 is engraved from the outside of the can with a groove width of 0.5 mm and a wall thickness of 0.2 mm at the bottom of the groove. In this case, the bottom of the can that is pushed away by engraving the explosion-proof thin groove is the same as when engraving a can with a bottom thickness of 0.6 mm. No deformation of the can bottom occurs.

In the case of impact molding, the thin portion 10 can be easily formed if it has a shape symmetrical with respect to the center of the can bottom or a shape close thereto. FIG. 6 shows an example in which the shape of the thin portion 10 is slightly shifted with respect to the center symmetry of the can bottom. However, the thin portion 10 can be formed even with the same shape.

It is needless to say that the thin portion 10 can be formed by molding from the same side as the explosion-proof thin groove 9, that is, from the outside of the can.

[0028]

According to the present invention, since the thin portion made thin by the explosion-proof thin groove engraving to the thickness where the influence of the distortion of the can does not appear is set around the explosion-proof thin groove, the thick-walled can is enlarged. , The explosion-proof thin groove can be easily engraved.

[Brief description of the drawings]

FIG. 1 is a front view of a can bottom viewed from the outside of a can according to an embodiment of the present invention.

FIG. 2 is a front view of a can bottom seen from the inside of the can of FIG. 1;

FIG. 3 is a sectional view of a bottom of the thin can of FIG. 1 provided with an explosion-proof thin groove.

FIG. 4 is a sectional view of the bottom of the thick can of FIG. 1 provided with an explosion-proof thin groove.

5 is a cross-sectional view of a can bottom provided with a thin portion around the explosion-proof thin groove in FIG. 4;

FIG. 6 is a front view showing an example of an explosion-proof container according to another embodiment, in which the shape of the explosion-proof thin groove is not symmetrical with respect to the center of the can bottom.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Can side part, 2 ... Can bottom part, 3, 6, 7, 9 ... Explosion-proof thin-groove, 4 ... Explosion-proof thin-groove intersection, 5 ... Thin-wall, 8 ... Explosion-proof thin-groove engraving press type, 10 ... Thin-wall.

Claims (1)

[Claims] An explosion-proof container provided with a thin-walled groove as an explosion-proof valve on the side or bottom surface of a bottomed container, wherein a peripheral portion of the groove (width of 20 mm or less across the groove) of the explosion-proof thin-walled groove is provided on the container plate. An explosion-proof container characterized by being formed into a thickness (0.3 to 1.0 mm) smaller than the thickness.