JPS6214479Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is applied to a safety sealing plate, and by forming a minute truncated conical recess for initial crack generation in the central part of the truncated surface of a local truncated conical recess, this sealing plate becomes a seal. If the internal pressure of a small gas cylinder increases abnormally for some reason, this minute recess, i.e., the center of the truncated surface of the local truncated conical recess, will first be ruptured, and this recess will also be induced to the local recess side. This is to ensure that hair cracks are generated toward the outer periphery.

Since conventional safety sealing plates only have local recesses formed on the plate surface, some variation was observed when the safety sealing plates operated due to overpressure. One of the purposes of the safety seal plate is to release the gas inside the cylinder at a rate that prevents the cylinder from flying away, but depending on the size of the cylinder (i.e., the weight), large ones may be immovable. However, small objects naturally have less static friction, so they sometimes move even if they don't fly away. The cause is the state of destruction of the local recess.

When actually mass-producing sealing plates, a truncated conical recess is used to prevent the molding punch from sagging and to control the shape. Ideally, when the internal pressure of the cylinder rises abnormally, stress is concentrated at the center of the bottom of the truncated conical recess, and a crack grows from there. The crack that grows from the center crosses the circumference of the bottom surface of the truncated conical recess at right angles and stops at the thick part, forming a hair crack. However, unless the shape is controlled very strictly, it is usually impossible to eliminate scratches on the bottom of the recess and deviations in plate thickness during molding.
This causes initial failure to occur from areas other than the center of the bottom surface. In this case, the crack does not advance perpendicularly toward the circumference of the bottom surface, so when it reaches the circumference of the bottom surface, it grows along this circumference due to radial stress, resulting in an extremely large opening area. As a result, the amount of gas released increases and the thrust force applied to the cylinder also increases.

In order to set a limit on the growth range of this crack, the applicant has also proposed a method of providing recesses on both opposing surfaces of the sealing plate. According to this, although the growth range of cracks can be controlled, it is not possible to determine the point at which the cracks themselves occur. Therefore, if the crack does not start from the center of the bottom part of the recess,
The same defective operation as above may occur.

Therefore, in this case, when the safety sealing plate is activated, a minute crack is first generated in the central part of the truncated conical local recess, and this is used as the starting point to create a crack on the bottom surface of the truncated conical local recess. The purpose is to extend this crack perpendicularly to the circumferential direction, and a specific example thereof will be described in detail with reference to the drawings as follows.

Reference numeral 1 denotes a surface opposite to the facing surface 2 facing the opening surface O of the cylinder B to be sealed, that is, the rear surface, and 3 a local truncated conical recess formed in the center of this surface 1. A minute truncated conical recess 5 is formed in the center of the pedestal surface 4 of this recess 3. Reference numeral 6 denotes a recess that is provided as necessary when the thickness of the sealing plate is thick, and is provided opposite to the recess 3.

FIG. 4 shows a case where a local truncated conical recess 13 is formed in the center of the opposing surface 2, and a minute truncated conical recess 15 is formed in the center of the truncated surface 14. Also in this case, when the thickness of the sealing plate is thick, the recess 16 is provided opposite the recess 13 as necessary.

In the drawings, 21 is an annular leg for preventing escape.

The illustrated sealing plate is usually welded to the open end surface of the bomb B, and seals the gas inside the bomb B. When the pressure inside the cylinder B rises abnormally due to the heat of the fire, the central portion of the opposing surface 2 curves outward into an arcuate cross-section, and tensile and shear stress acts on the thin bottom portion of the recess 5, causing it to finally break down. In order to cause the crack to grow with the recess 5 as an induced starting point, fine hair cracks C are generated perpendicularly to the circumferential direction of the recess 3 without growing the crack along the circumference of the bottom part. Therefore, the internal gas is gradually released to the outside through this hair crack, that is, at a rate at which the cylinder B does not fly out due to the reaction force.

In the case of FIG. 4, the operation is almost the same as in the case described above.

According to the present invention, since a small truncated conical recess for initial crack generation is formed in the central part of the truncated surface of a local truncated conical recess, the initial fracture can be reliably generated in this micro recess. A hair crack is induced at the bottom of the local recess that goes perpendicularly to its outer circumference using the fracture as a starting point, and therefore the opening does not have to be enlarged as would be the case when a fracture occurs at the outer circumference of the local recess. It is easy to control the discharge amount to such an extent that the cylinder does not fly away due to reaction force, which is extremely advantageous in terms of safety measures, and has various effects.

[Brief explanation of the drawing]

FIG. 1 is a half-cut side view showing a specific example of the safety sealing plate according to the present invention, FIG. 2 is a plan view of the same half, and FIG.
The figure is a cut side view in a broken state, and FIG. 4 is a half cut side view showing another embodiment of the sealing plate of the present invention. 1... Back surface, 2... Opposing surface, 3, 13... Local truncated conical recess, 4, 14... Trapezoidal surface, 5, 1
5...Small truncated conical recess for initial crack generation, B
...Cylinder, O...opening surface.

Claims (1)

[Scope of utility model registration request] Forming a local truncated conical recess in the center of a surface opposite or opposite to the cylinder opening surface to be sealed,
This safety sealing plate has a small truncated conical recess formed in the center of the pedestal of this recess for initial crack generation.