JP4292341B2 - safety valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a safety valve, and more particularly to a safety valve that is attached to a container to release gas in the container when the temperature rises in order to prevent the pressure in the container from rising excessively.
[0002]
[Prior art]
In a fuel tank mounted on an automobile using natural gas as fuel for an engine, a safety valve is attached to the fuel tank in order to prevent explosion due to an increase in internal pressure accompanying an increase in the temperature of the tank. As such a safety valve, in Patent Document 1, a main body, a piston (moving body) accommodated in the main body, a fusible alloy filled between the piston and the main body, and between the piston and the main body are disclosed. The piston is provided with a passage communicating with both ends, and the both end portions are provided with a first pressure receiving surface and a second pressure receiving surface. The passage of the piston is blocked from the outside by screwing a cap onto the main body.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-317645
[Problems to be solved by the invention]
Since this type of safety valve is used not only in a natural gas tank but also in a hydrogen gas tank of a fuel cell vehicle, development of an improved safety has been an issue.
[0005]
An object of the present invention is to provide a safety valve which is attached to a container and is configured to release gas in the container when the temperature rises and has improved safety.
[0006]
[Means for Solving the Problems and Effects of the Invention]
A safety valve according to the present invention is a safety valve that is attached to a container and releases the gas in the container when the temperature rises, and is formed between a cylindrical main body having an inward flange at the upper end and an inner periphery of the main body. A cylindrical fixed body having a small-diameter portion having a gap, a large-diameter portion that is connected to the lower end of the small-diameter portion and that closes the lower-end opening of the main body, a lower-end portion of the large-diameter portion, and a mounting portion that is attached to the container; A fusible body arranged between the small diameter portion of the fixed body and the main body so that the upper end surface abuts on the lower surface of the flange, and between the small diameter portion of the fixed body and the main body so that the upper end contacts the lower end of the fusible body. A movable body that is movably disposed on the movable body, and an attachment disposed between the small-diameter portion of the fixed body and the main body so that the upper end abuts the lower end of the movable body and the lower end is received by the upper surface of the large-diameter portion of the stationary body. Force member, and the middle part of the small diameter part An axial passage that extends to the lower end of the mounting portion and communicates with the inside of the container and a radial passage that opens to the outer periphery of the small-diameter portion and that opens to the outer periphery of the small-diameter portion are formed. When the moving body moves to the upper position, an axial passage that opens and a communication passage that is open in the main body and closed by the outer periphery of the moving body is formed. In addition, a radial through path is provided that communicates the inner end opening of the communication passage in the peripheral wall of the main body with the radial passage opening of the fixed body, whereby when the fusible body melts and the movable body moves to the upper position, The in-container gas is characterized by being released to the outside of the container through a fixed body axial passage, a fixed body radial passage, a moving body radial through passage, a main body communication passage, and a main body axial passage.
[0007]
According to the safety valve of the present invention, the pressure of the gas in the container is received by the fixed body fixed to the main body, and the pressure in the container does not reach the moving body. Only the elastic force is assumed, and malfunction at a temperature lower than the set value can be eliminated.
[0008]
A cylindrical cap that covers the upper end of the main body and has a through hole is further provided.When the fusible body melts and the moving body moves upward, the gas released from the upper end of the main body is separated from the upper end of the main body and the cap. It is preferable that the gas is discharged to the outside through the through hole and the through hole. In this way, even when there is no cap, since the discharge of gas to the outside is prevented, there is no malfunction even when the cap is accidentally removed.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In the following description, “upper and lower” and “left and right” refer to the upper and lower and left and right in the drawing.
[0010]
1 and 2 show an embodiment of the safety valve of the present invention. FIG. 1 shows a normal state where the ambient temperature of the safety valve is lower than a predetermined value, that is, a state where the passage is closed, and FIG. 2 shows an operating state where the ambient temperature of the safety valve exceeds a predetermined value, ie, a state where the passage is opened. Yes.
[0011]
As shown in FIG. 1, the safety valve (1) in the normal state has a gap between the main body (2) having a cylindrical shape and an inward flange portion (2a) at the upper end and the inner periphery of the main body (2). Small diameter part (4), connected to the lower end of the small diameter part (4) and connected to the container (T) and connected to the lower end of the large diameter part (5) and the large diameter part (5) closing the lower end opening of the main body (2) A cylindrical fixed body (3) having a mounting portion (6), and a small-diameter portion (4) of the fixed body (3) and the main body so that the upper end surface is in contact with the lower surface of the inward flange (2a) of the main body (2). (2) Cylindrical fusible alloy (soluble body) (7) placed between the upper end and the small diameter part of the fixed body (3) so that the upper end abuts the lower end of the fusible alloy (7) ( 4) and a cylindrical moving body (8) arranged movably between the middle part of the main body (2), the upper end abuts the lower end of the moving body (8), and the lower end is the fixed body (3). Circle arranged between the small diameter part (4) of the fixed body (3) and the main body (2) near the lower end so that it can be received on the upper surface of the large diameter part (5) And Jo coil spring (urging member) (9), and a body (2) a cylindrical cap placed over the upper portion (10).
[0012]
A male screw part (5a) is provided on the outer periphery of the large-diameter part (5) of the fixed body (3), and this male screw part (5a) is provided on the inner periphery of the lower end of the main body (2). The fixed body (3) is fixed to the main body (2) by being screwed together. The large-diameter portion (5) of the fixed body (3) has a flange portion (5b) interposed between the lower end surface of the main body (2) and the outer periphery of the container (T). The mounting portion (6) is shaped according to the shape of the safety valve mounting portion of the container (T), and in this embodiment, the male screw portion that is provided in the opening of the container (T) and is screwed to the screw portion. (6a) is provided on the mounting portion (6).
[0013]
The fixed body (3) is formed with an axial passage (11) extending from the middle of the small diameter portion (4) to the lower end of the mounting portion (6) and leading into the container (T). Left and right radial passages (12) are formed that open to the outer periphery of the small diameter portion (4) and communicate with the upper end of the axial passage (11). The position of the radial passage (12) is a position where the upper portion of the moving body (8) is located, and the opening of the radial passage (12) is closed by the upper portion of the moving body (8).
[0014]
The fusible alloy (7) is a well-known one and melts at a preset temperature. An alloy discharge passage (13) for discharging the molten alloy (7) to the outside is provided at the upper end of the main body (2).
[0015]
The movable body (8) is slidable with its inner circumference in contact with the small diameter portion (4) of the stationary body (3) and its outer circumference in contact with the inner circumference of the main body (2). ) And the fixed body (3). The small diameter portion (4) of the fixed body (3) is formed with upper and lower annular recesses into which the seal member (14) is fitted so as to sandwich the radial passage (12) from both the upper and lower sides. An upper and lower seal member (14) made of an O-ring made of PT and a backup ring made of PTFE is fitted in each recess. Thus, the radial passage (12) is closed by the moving body (8).
[0016]
The movable body (8) is provided with left and right radial through paths (15) penetrating the movable body (8) in the radial direction below the lower seal member (14). When these fusible alloys (7) are melted and the movable body (8) is moved to the upper position, the inner end openings of the radial through paths (15) are fixed bodies (15). It is formed so as to communicate with the opening of the radial passage (12) of 3).
[0017]
The coil spring (9) biases the moving body (8) upward, and when the soluble alloy (7) is melted, the soluble alloy (7) is removed from the alloy discharge passage (13) of the main body (2). It is discharged and moves the moving body (8) upward, and its elastic force takes into account the flow characteristics of the soluble alloy (7) at the temperature set so that the safety valve (1) operates. The movable body (8) can be moved upward and is set to a small value.
[0018]
In the peripheral wall of the main body (2), two axial passages (16) opened at the upper end thereof are formed. The lower ends of these axial passages (16) are positioned below the upper end of the moving body (8). On the inner periphery of the main body (2), an annular communication path (17) is formed which communicates with the lower end of the axial passage (16) and opens into the main body (2) and is closed by the outer periphery of the moving body (8). Has been. The communication passage (17) is formed at a position corresponding to the radial passage (12) of the fixed body (3) so as to have an opening width larger than the opening width of the radial passage (12).
[0019]
The cap (10) has a peripheral wall (18) provided with an inner peripheral female screw portion (18a) and a top wall (19) provided with a through female screw portion (19a). The inner peripheral female screw portion (18a) is screwed to the male screw portion provided at the upper end portion, thereby being fixed to the main body (2). An axial passage communication space (20) is provided between the bottom surface of the top wall (19) of the cap (10) and the upper end of the main body (2), and the upper end of the axial passage (16) of the main body (2). The opening communicates with the external space through the axial passage communication space (20) and the through female thread portion (19a).
[0020]
When the ambient temperature of the safety valve (1) exceeds a predetermined value, the fusible alloy (7) is melted and the safety valve (1) is activated. As shown in FIG. 2, in the safety valve (1) in this operating state, the fusible alloy (7) is discharged from the alloy discharge passage (13) and disappears, and the movement is biased by the coil spring (9). The body (8) has moved to the upper position. The upper position of the moving body (8) is a position where the upper end of the moving body (8) is in contact with the lower surface of the inward flange (2a) of the main body (2). The passages (11), (12), (16) and (17) of the main body (2) and the fixed body (3) naturally remain the same as in FIG. 1, and the moving body (8) and therefore the moving body (8) Due to the upward movement of the radial through passage (15), an open passage for discharging the gas in the container (T) is formed in the safety valve (1). That is, when the fusible alloy (7) is melted and the moving body (8) moves to the upper position, the gas in the container (T) flows into the fixed body axial passage (11), the fixed body radial passage (12). , Through the moving body radial direction through passage (15), the main body communication passage (17), the main body axial passage (16), and the cap lower axial passage communication space (20), the through screw portion (19a) of the cap (10) Note that the left and right sides (12), (13), (15), and (16) in the above are not necessarily limited to the two on the left and right, and are not shown in the drawing. And may be provided on the back side, respectively, or may be equally arranged at three locations in the circumferential direction.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a safety valve according to the present invention and showing a normal state (closed state).
FIG. 2 is a cross-sectional view showing an embodiment of a safety valve according to the present invention, and shows an operating state (open state).
[Explanation of symbols]
(1) Safety valve
(2) Body
(2a) Flange
(3) Fixed body
(4) Small diameter part
(5) Large diameter part
(6) Mounting part
(7) Soluble alloy (soluble material)
(8) Mobile object
(9) Coil spring (biasing member)
(11) Axial passage
(12) Radial passage
(15) Radial through passage
(16) Axial passage
(17) Communication passage

Claims (2)

A safety valve that is attached to a container and releases the gas in the container when the temperature rises, and has a small diameter part that has a gap between the cylindrical main body having an inward flange at the upper end and the inner periphery of the main body A cylindrical fixed body having a large-diameter portion that is connected to the lower end of the small-diameter portion and that closes the lower-end opening of the main body, a lower-end portion of the large-diameter portion, and a mounting portion that is attached to the container; Is disposed between the small diameter portion of the fixed body and the main body so that the upper end contacts the lower end of the soluble body. And a biasing member disposed between the small diameter portion of the fixed body and the main body so that the lower end of the movable body is in contact with the lower end of the movable body and the lower end is received by the upper surface of the large diameter portion of the fixed body. And
The fixed body is formed with an axial passage extending from the middle of the small diameter portion to the lower end of the mounting portion and leading to the inside of the container, and a radial passage that opens to the outer periphery of the small diameter portion. In the peripheral wall of the main body, there are formed an axial passage that opens at the upper end thereof and a communication passage that opens to the lower end of the axial passage and is closed in the outer periphery of the mobile body. When the moving body moves to the upper position, a radial through path is provided that communicates the inner end opening of the communication passage on the peripheral wall of the main body with the radial passage opening of the fixed body,
As a result, when the fusible body melts and the moving body moves to the upper position, the gas in the container flows into the fixed body axial passage, the fixed body radial passage, the moving body radial through passage, the main body communication passage, and the main body axial direction. A safety valve that is opened to the outside of the container through a passage. A cylindrical cap that covers the upper end of the main body and has a through hole is further provided. 2. The safety valve according to claim 1, wherein the safety valve is discharged to the outside through a through hole and through a through hole.

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