JP2614783B2 - Pressure vessel safety valve - Google Patents

Description

The present invention relates to a safety valve for a pressure vessel, and more particularly to a heat-sensitive safety valve of a type that opens under abnormal heating conditions.
In a safety valve in which a through hole formed in a component wall of a pressure vessel is closed by a low-melting-point metal closing body, the safety valve is to be surely opened at the time of abnormal heating and to improve airtightness at normal times. For this purpose, the mode of closing the through hole by the closing body is closed from both the inside and outside surfaces of the component wall.

Further, the airtightness is further improved by covering the peripheral edge of the closed portion on the inner surface side with a coating layer made of a synthetic resin.

[Prior art and its problems] Japanese Patent Application No. 2-46526 has already proposed a safety valve in which a through hole formed in a constituent wall of a pressure vessel is closed by a closing body made of a low melting point metal.

As shown in FIG. 6, a concave portion (1) projecting inward into the center of a bottom plate (11) serving as a constituent wall of the pressure vessel (1) is provided.
3) to form a hole (14) in the center of this recess (13)
The through hole (14) is closed from the outer surface side of the bottom plate (11) by a closing body (14) made of a low melting point metal.

In this case, since the melting point of the closing body (3) is set to a predetermined temperature, when the pressure vessel (1) is left under abnormal temperature conditions, the closing body (3) melts and becomes transparent. The hole (14) is opened, the pressure in the pressure vessel (1) is reduced, and an accident such as an explosion can be prevented. Further, such a heat-sensitive safety valve can be realized with a simple configuration.

However, in this case, the through hole (14) formed by the closing body (3) is used.
The airtightness at the time of the blockage may be insufficient depending on the blockage state of the blockage. This is because the possibility of leakage remains only by closing the through hole (14) from the outer surface side of the constituent wall of the pressure vessel (1) with the closing body (3).

The present invention has been made in view of such a point,
"Thermal safety valve in which the through-hole (14) formed in the component wall of the pressure vessel (1) is closed by a low-melting-point metal closing body (3)" is intended to ensure airtightness in the closed state. Make it an issue.

* The invention of claim 1 [Technical Means] The technical means of the present invention taken to solve the above-mentioned problem is as follows: "The closing body (3) penetrates the through-hole (14) and the pressure vessel (1 The closing body (3) comprises a plug for filling the through-hole and a pair of closing parts which are in close contact with the inside and outside surfaces of the constituent wall, and the closing body (3). Means that the plug portion and the pair of closing portions are integrally connected. "

[Operation] The above technical means of the present invention operates as follows.

The closing body (3) passes through the component wall of the pressure vessel (1) through the through-hole (1).
It is mounted so as to penetrate through the through-hole 4), and the closed portions provided on both the inner and outer surfaces of the component wall close the outer peripheral portion of the entire peripheral edge of the through hole (14).

Therefore, the through hole (14) is formed by the closing body (3) penetrating therethrough.
And closed by the pair of closing portions which are in close contact with both inner and outer surfaces. That is, the through-hole (14) formed through the component wall of the pressure vessel (1) is triple-closed by the inner and outer closing portions and the plug filled in the through-hole (14).

Further, since the melting point of the closing body (3) is set to a predetermined temperature, when the pressure vessel (1) is placed under abnormal heating conditions, the closing body (3) melts depending on the temperature at this time. Then, the through hole (14) is opened, and the internal pressure of the pressure vessel (1) is reduced.

[Effects] The present invention has the following configuration, and thus has the following specific effects.

Since the through-hole (14) is closed three times by the low-melting-point metal closing body (3), the airtightness of the closing body (3) under normal temperature conditions is ensured.

* Invention of Claim 2 According to the invention of Claim 2, the configuration of the constituent wall of the pressure vessel (1) in the invention of Claim 1 is specified, and the through-hole (14) is closed by the closing body (3). In order to further improve the hermeticity of the state, the means specified for this purpose is described as follows. "The inner surface of the component wall of the pressure vessel (1) equipped with the closing body (3) is covered with the synthetic resin layer (2). An opening (21) was formed in the synthetic resin layer (2) at a position corresponding to the center of the closed portion on the inner surface side of the closed body (3). "

By adopting this configuration, the portion of the outer peripheral area of the opening (21) closes the joint between the closing part of the closing body (3) and the constituent wall of the pressure vessel (1), and the airtightness at normal time is further improved. improves.

Since the synthetic resin layer (2) is provided with an opening at a position corresponding to the center of the closing portion of the closing body (3), the closing body (3) is melted and the through hole (14) is opened. In this case, the inside and outside of the pressure vessel (1) communicate with each other, and the synthetic resin layer (2) does not hinder safe operation.

* Invention of Claim 3 In the invention of Claim 2, as in the invention of Claim 3, "the melting point of the synthetic resin layer (2) is set higher than the melting point of the closing body (3). Is desirable. Usually, the temperature of the safe operation substantially coincides with the melting point of the closing body (3), so that the inconvenience of melting the synthetic resin layer (2) by the time of the safe operation can be solved.

* Invention of Claim 4 In the invention of Claims 1 to 3, the pressure vessel (1) and the formation part of the through-hole (14) are as follows.
[The pressure vessel (1) is configured to include a vessel main body and a bottom plate (11) constituting the bottom thereof, and the bottom plate (11) has a spherical shape projecting upward, and is provided at a central portion of the bottom plate (11). Is provided with a concave portion (13) recessed upward, and said concave portion (13)
The through-hole (14) is formed at the same time, "when the closing body (3) is melted, the through-hole (14) is opened smoothly, so that the safe operation at the set temperature is smooth and reliable. .

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS.

* First Embodiment The embodiment shown in FIG. 1 is a bottom plate (11) of a pressure vessel (1).
In this embodiment, the through hole (14) of the recess (13) is closed by a closing body (3). In this embodiment, as shown in FIG. A rivet having a head (31) of a shape set according to the shape is used as the closing body (3). In this apparatus, the rivet is made of a low melting point alloy material, and the rivet is mounted from the outer surface side of the bottom plate (11), and its shaft (21) is passed through a through hole (14). 5, bottom plate (11)
The shaft portion (32) protruding toward the inner surface side is caulked,
The closing body (3) is configured as shown in FIG. In this case, the head (31) becomes a closing part on the outer surface side of the closing body (3),
A part of the shaft part (32) flattened by caulking becomes a closed part on the inner surface side of the closed body (3).

The pressure vessel (1) of this embodiment is an aerosol vessel, and the bottom plate (11) is caulked to the opening at the lower end of the body of the pressure vessel (1) to fill the contents and the valve device (V). Is attached to the lid plate (10).

In this embodiment, the closing body (3) is provided on the bottom plate (11) as a constituent wall of the pressure vessel (1). However, the closing body (3) is provided with another constituent wall, for example, a lid plate (10). ) Or the body of the pressure vessel (1).

* Second Embodiment This embodiment corresponds to the second aspect of the present invention, and uses a bottom plate (11) whose inner surface is coated with a synthetic resin layer (2) as shown in FIG.

A metal plate provided with the synthetic resin layer (2) is punched into a blank having a predetermined shape in advance, and bent into a predetermined cross-sectional shape by drawing. At this time, the recess (13)
And a through hole (14) is formed. Since the synthetic resin layer (2) is simultaneously punched when the through hole (14) is formed, a portion corresponding to the through hole (14) becomes an opening (21).

In this embodiment, the concave portion (13) has a spherical shape, the diameter of the concave portion (13) is set to about 5 mm to 8 mm, and the through hole (14) formed in the center thereof has a diameter of 0.5 mm to It is about 2.0mm. Then, a low melting point alloy is melt-bonded so as to cover substantially the entire bottom wall of the recessed portion (13), thereby forming a closed body (3).
It has become. At this time, the weight of the low melting point alloy ranges from 0.6 g to 1.
About 6 g is appropriate, and the thickness of the low melting point alloy is 0.5 mm.

In addition, the melting point of this low melting point alloy
The temperature is set at 95 ° C to 180 ° C, preferably 100 ° C to 15 ° C.
Set to 0 ° C. Depending on the use conditions of the sealed container, the temperature may be set lower than this temperature or higher than this temperature.

To melt-bond a low melting point alloy to the bottom plate (11) used in the container of the above embodiment, a method as shown in FIG. 4 is employed.

Although the melting point of the synthetic resin layer (2) is naturally higher than the melting point of the closing body (3), the temperature of the softening point of the synthetic resin layer (2) also depends on the melting point of the closing body (3). For example, when the melting point of the closing member (3) is set to 100 ° C. to 150 ° C. as described above, the synthetic resin layer (2) is made of an epoxy-phenol resin. Can be used.

In this method, a conveyor (41) is disposed so as to pass through a heating furnace (4), and pellets (P) of a low melting point alloy are provided upstream of the heating furnace (4) in the transfer direction of the conveyor (41). ) Is located. The size of each pellet (P) is a size corresponding to the above-mentioned weight.

The conveyor (41) is provided with support bases (43) and (43) for supporting the bottom plate (11) in a downwardly protruding posture at predetermined intervals, and each of the support bases (43) The bottom plate (11) is placed on the conveyor and the conveyor (41) is run at a predetermined speed.

At the outlet of the hopper (42), pellets (P)
An input device (5) for dropping (P) one by one is provided, and the input device (5) operates at a predetermined timing by an output from a detection device (51) for detecting the bottom plate (11).

Therefore, when the detecting device (51) detects that the bottom plate (11) is located below the outlet of the hopper (42), the input device (5) is operated according to the output at this time, and the output from the hopper (42) is reduced. Pellets (P) are dropped and the bottom plate (11) is moved to the hopper (4
Each time it is located below 2), the above operation is repeated.

The pellet (P) put into the bottom plate (11) by the above procedure is not put into the recess (13) accurately, but the bottom plate (11) is supported by the support bases (43) and (43). In the posture, the upper surface side is concave (spherical), so that the pellet (P) put into the bottom plate (11) is surely located in the concave portion (13). In addition, since the concave portion (13) is also concave (spherical), the pellet (P) located in the concave portion (13) coincides with the through hole (14) located in the center thereof. .

As described above, each bottom plate (11) is placed on the conveyor (41) while the pellets (P) are accommodated so as to match the through holes (14).
Is sent into the heating furnace (4) as the vehicle travels, the atmosphere temperature in the heating furnace (4) is set higher than the melting point of the low melting point alloy. Since the length of the pellet (P) is set to a predetermined value, the pellet (P) contained in the recess (13) is melted and passes through the bottom wall of the recess (13) while passing through the heating furnace (4). Melts and diffuses.

In particular, in this embodiment, the temperature in the heating furnace (4) is set higher than the softening point of the synthetic resin layer (2) and lower than the melting point of the synthetic resin layer (2). Therefore,
As described above, the molten alloy that has melted and diffused into the bottom wall of the recess (13) flows out to the back side of the bottom plate (11) through the through hole (14), and the synthetic resin layer (2) on the back surface and the bottom plate (11). 5), and the periphery of the closed portion on the back surface side of the bottom plate (11) is covered with the synthetic resin layer (2) as shown in FIG.

Although the principle of intrusion of the molten alloy has not been elucidated, under conditions where the synthetic resin layer (2) is heated to a temperature higher than the softening point, the metal layer and the synthetic resin layer ( It is considered that the bond with 2) is weak, and the molten alloy enters the boundary from the portion. In the case where the synthetic resin layer (2) is made of an epoxy-phenol resin, when the atmosphere temperature in the heating furnace (4) is set at about 250 ° C., the molten alloy is formed between the metal layer and the synthetic resin layer (2). Invaded moderately in between.

In this embodiment, an air cooling device (6) is provided downstream of the heating furnace (4), and the low melting point alloy diffused and melted at the bottom of the recess (13) hardens while passing therethrough. Then, this is melt-bonded to the front and back of the bottom wall of the recess (13) to form the closing body (3), and the through hole (14) is closed.

When the bottom plate (11) having the through hole (14) closed with the low melting point alloy is crimped to the lower end opening of the pressure vessel (1) in this way, the closed vessel is completed.

In the case of an aerosol container, a high-pressure gas body is sealed in the closed container, and the sealing operation of the high-pressure gas body is performed by a known method. In some cases, the bottom plate (11)
May be separately provided at the bottom of the valve.

When a special high-pressure gas filling device is used, such as when the liquefied gas is filled in a high-pressure chamber and the bottom plate is caulked, the valve for filling the high-pressure gas is unnecessary.

Various known alloys can be used as the low melting point alloy used in the above embodiment. For example, solder or the like can be used.
Incidentally, as this kind of alloy, an alloy of bismuth, lead, tin or the like is generally used. In this alloy, various melting points can be set by changing the ratio of each of the above components. For example, 50 ° C
Alloys that melt at temperatures as low as about one can be made.

In the above embodiment, the safety valve is provided at the bottom of the aerosol container. However, it is needless to say that the safety valve of the present invention can be applied to other types of hermetically sealed containers. It is not necessary to make 11) an inward cross-sectional shape. Furthermore, in the invention of claim 2, if the bottom plate (11) has a shape such as a conical shape whose central portion gradually projects inward from the outer peripheral portion, this bottom plate (1) is not necessarily required.
1) need not be spherical. It is not necessary to make the concave portion (13) substantially spherical.

Furthermore, the pellets (P) may be manually charged, or the low melting point alloy may be hardened by natural cooling without using the air cooling device (6). or,
It goes without saying that it can be used for various containers other than the aerosol container of the above embodiment. Further, the present invention can be applied to a container of a type coated with a synthetic resin layer having an inner surface of the body of the pressure container (1).

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention, FIG. 2 is a detailed view of a main part of a bottom plate (11), and FIG. 3 is a bottom plate (1) of another embodiment.
1) is a sectional view, FIG. 4 is an explanatory view of a method of manufacturing a bottom plate (11) with a safety valve of this sealed container, FIG. 5 is an enlarged view of a main part of the second embodiment, and FIG. It is an explanatory view of (1) ... pressure vessel (14) ... through-hole (3) ... closed body (2) ... synthetic resin layer (21) ... opening

Claims (4)

(57) [Claims] 1. A heat-sensitive safety valve in which a through-hole (14) formed in a component wall of a pressure vessel (1) is closed by a closing body (3) made of a low-melting-point metal, wherein the closing body (3) has the through-hole. Through the hole (14), the inner and outer surfaces of the component wall of the pressure vessel (1) are reached, and the closing body (3) has a plug portion filling the through-hole and a pair of close-fitting inner and outer surfaces of the component wall. The closure (3) is a safety valve for a pressure vessel in which the plug and the pair of closures are integrally connected. 2. An inner surface of a constituent wall of a pressure vessel (1) on which said closing body (3) is mounted is covered with a synthetic resin layer (2), and said synthetic resin layer (2) is covered with said closing body (3). 2. The safety valve for a pressure vessel according to claim 1, wherein an opening (21) is formed at a position corresponding to the center of the closed portion on the inner surface side of (1). 3. The pressure valve safety valve according to claim 2, wherein the melting point of the synthetic resin layer (2) is set higher than the melting point of the closing body (3). 4. The pressure vessel (1) comprises a vessel main body and a bottom plate (11) constituting a bottom thereof, wherein the bottom plate (11) is formed in a spherical shape projecting upward. The pressure vessel according to any one of claims 1 to 3, wherein a concave portion (13) recessed upward is provided at a central portion of the pressure vessel, and the through hole (14) is formed in the concave portion (13). safety valve.