JP2004270809A - Safety valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the safety in a safety valve attached to a container in which gas in a container is released when a temperature rises. <P>SOLUTION: The safety valve 1 is provided with a cylindrical body 2, a columnar fixed body 3, a fuse element 7, a movable body 8, and a booster member 9. In the fixed body 3, there are formed a radial passage 11 leading into the container T expanding from the middle of a minor diameter part 4 to the lower part of a mounting part 6, and a radial passage 12 leading to the upper end of the radial passage 11 and opening to a circumference of the minor diameter part 4. In a lower peripheral wall of the body 2, there is formed a communicating passage 17 which leads to an axial passage 16 opening at the upper end and a lower end of the axial passage 16, opens into the body 2, and is closed with the circumference of the movable body 8. In the movable body 8, there is provided with a radial penetrating passage 15 communicating an inner end opening of a communicating passage 17 of a peripheral wall of the body 2 to an opening of a radial passage 12 of the fixed body 3, when the movable body 8 moves to an upward position. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a safety valve, and more particularly to a safety valve that is attached to a container and releases gas in the container when the temperature rises, in order to prevent the pressure inside the container from excessively increasing.
[0002]
[Prior art]
2. Description of the Related 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 rupture due to an increase in internal pressure due to an increase in the temperature of the tank. As such a safety valve, Patent Literature 1 discloses a body, a piston (moving body) housed in the body, a fusible alloy filled between the piston and the body, and a valve between the piston and the body. The piston is provided with a passage communicating with both ends, and the both ends are provided with a first pressure receiving surface and a second pressure receiving surface. The passage of the piston is shielded from the outside by screwing the cap onto the main body.
[0003]
[Patent Document 1]
JP 2001-317645 A
[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 a safety valve with further improved safety has been an issue.
[0005]
SUMMARY OF THE INVENTION An object of the present invention is to provide a safety valve which is attached to a container and releases gas in the container when the temperature rises, in which safety is further improved.
[0006]
Means for Solving the Problems and Effects of the Invention
The safety valve according to the present invention is a safety valve that is attached to a container and releases gas in the container when the temperature rises, and is a valve between a cylindrical main body having an inward flange portion at an upper end portion and an inner periphery of the main body. A cylindrical fixed body having a small-diameter portion having a gap, a large-diameter portion connected to the lower end of the small-diameter portion and closing the lower end opening of the main body, and a mounting portion connected to the lower end of the large-diameter portion and attached to the container; Between the fusible body disposed between the small diameter portion of the fixed body and the main body such 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 such that the upper end abuts on the lower end of the fusible body A movable body disposed so as to be movable to a lower end of the fixed body and the main body such that the upper end abuts on the lower end of the movable body and the lower end is received on the upper surface of the large diameter portion of the fixed body. And a biasing member. An axial passage extending to the lower end of the mounting portion and communicating with the inside of the container, and a radial passage communicating with the upper end portion of the axial passage and opening on the outer periphery of the small diameter portion are formed. A communication path is formed which is open to the axial passage and the lower end of the axial passage and is opened in the main body and closed by the outer periphery of the moving body, and when the moving body moves to the upper position, There is provided a radial through passage that communicates the inner end opening of the communication passage of the main body peripheral wall with the radial passage opening of the fixed body, whereby when the fusible material is melted and the moving body moves to the upper position, The gas in the container is characterized by being released to the outside of the container via the fixed member axial passage, the fixed member radial passage, the moving member radial through passage, the main body communication passage, and the 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. Since only the elastic force is used, malfunction at a temperature lower than the set value can be eliminated.
[0008]
Further provided is a cylindrical cap that is placed on the upper end of the main body and has a through hole, and when the fusible body is melted and the moving body moves upward, the gas released from the upper end opening of the main body is the upper end of the main body and the cap. It is preferable that the air is discharged to the outside through the gap and through holes. In this way, even when there is no cap, since the gas is prevented from being discharged to the outside, malfunction does not occur even if the cap is accidentally removed.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In the following description, up, down, left, and right refer to up, down, left, and right in the figure.
[0010]
1 and 2 show an embodiment of a safety valve according to the present invention. FIG. 1 shows a normal state in which the ambient temperature of the safety valve is below a predetermined value, that is, a state in which the passage is closed, and FIG. 2 shows a state in which the ambient temperature of the safety valve exceeds a predetermined value, that is, a state in which the path is opened. I have.
[0011]
As shown in FIG. 1, the safety valve (1) in a normal state has a gap between a cylindrical body (2) having an inward flange (2a) at an upper end and an inner periphery of the body (2). The small diameter part (4), the large diameter part (5) that connects to the lower end of the small diameter part (4) and closes the lower end opening of the main body (2) and the lower end of the large diameter part (5) and is attached to the container (T). A columnar fixed body (3) having an attachment portion (6), a small-diameter portion (4) of the fixed body (3) and a main body such that an upper end surface abuts on a lower surface of an inward flange (2a) of the main body (2). (2) The cylindrical fusible alloy (fusible body) (7) disposed between the upper end and the small diameter portion (3) of the fixed body (3) such that the upper end abuts on the lower end of the fusible alloy (7). 4) a cylindrical moving body (8) movably arranged between the middle part of the main body (2) and an upper end abutting on a lower end of the moving body (8) and a lower end thereof; A cylindrical coil spring (attached) is disposed between the small diameter portion (4) of the fixed body (3) and the body (2) near the lower end so as to be received on the upper surface of the large diameter portion (5) of the fixed body (3). (9), and a cylindrical cap (10) covered on the upper end of the main body (2).
[0012]
An external thread (5a) is provided on the outer periphery of the large diameter portion (5) of the fixed body (3), and the external thread (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 part (5) of the fixed body (3) has a flange part (5b) interposed between the lower end face of the main body (2) and the outer periphery of the container (T). The mounting portion (6) has a shape corresponding to the shape of the safety valve mounting portion of the container (T). In this embodiment, the male screw portion is provided at 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 communicating with the container (T). Left and right radial passages (12) are formed which communicate with the upper end of the axial passage (11) and open on the outer periphery of the small diameter portion (4). The position of the radial passage (12) is the position where the upper part of the moving body (8) is located, and the opening of the radial passage (12) is closed by the upper part of the moving body (8).
[0014]
The fusible alloy (7) is a publicly known one, and is configured to be melted 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 periphery in contact with the small diameter portion (4) of the fixed body (3) and its outer periphery in contact with the inner periphery of the main body (2). ) And the fixed body (3). Upper and lower annular recesses into which the sealing member (14) is fitted are formed in the small diameter portion (4) of the fixed body (3) so as to sandwich the radial passage (12) from both upper and lower sides thereof. An upper and lower seal member (14) comprising an O-ring made of PTFE and a backup ring made of PTFE is fitted into each recess. Thereby, the radial passage (12) is closed by the moving body (8).
[0016]
The moving body (8) is provided with left and right radial through paths (15) penetrating the moving body (8) in the radial direction below the lower seal member (14). When the fusible alloy (7) is melted and the moving body (8) moves to the upper position, the inner end opening of the radial through-passage (15) is fixed to the fixed through-body (15). 3) It is formed so as to communicate with the opening of the radial passage (12).
[0017]
The coil spring (9) urges the moving body (8) upward, and when the fusible alloy (7) is melted, moves the fusible alloy (7) from the alloy discharge passage (13) of the main body (2). It discharges and moves the moving body (8) upward, and its elastic force is determined in consideration of the flow characteristics of the fusible alloy (7) at a temperature set so that the safety valve (1) operates. , The moving body (8) can be moved upward and set to a small value.
[0018]
In the peripheral wall of the main body (2), two axial passages (16) opening at the upper end thereof are formed. The lower ends of these axial passages (16) are located lower than the upper end of the moving body (8). On the inner periphery of the main body (2), an annular communication passage (17) is formed which communicates with the lower end of the axial passage (16), opens in the main body (2), and is closed by the outer periphery of the moving body (8). Have 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 internal female thread (18a) and a top wall (19) provided with a penetrating female thread (19a). The inner circumference female thread portion (18a) is screwed to a male thread 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 lower 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). An opening communicates with the external space via the axial passage communication space (20) and the internal thread portion (19a).
[0020]
When the ambient temperature of the safety valve (1) exceeds a predetermined value, the fusible alloy (7) melts and the safety valve (1) is activated. As shown in FIG. 2, the safety valve (1) in this operating state has the fusible alloy (7) discharged from the alloy discharge passage (13) and disappears. 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), (17) of the body (2) and the fixed body (3) naturally remain the same as in FIG. 1 and the moving body (8) and thus the moving body (8) Due to the upward movement of the radial through passage (15), an open passage for discharging 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 through the fixed body axial passage (11) and the fixed body radial passage (12). Through the movable body radial through passage (15), the main body communication passage (17), the main body axial passage (16), and the cap lower axial passage communication space (20), and through the thread portion (19a) of the cap (10). (12), (13), (15), and (16) are not necessarily limited to two on the right and left sides, and are not shown. And on the back side, or may be equally spaced at three places in the circumferential direction.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an embodiment of a safety valve according to the present invention, showing a normal state (closed state).
FIG. 2 is a sectional view showing an embodiment of the safety valve according to the present invention, showing 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) Fusible alloy (fusible)
(8) Moving body (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 gas in the container when the temperature rises, and has a cylindrical main body having an inward flange at an upper end portion, and a small-diameter portion having a gap between the main body inner periphery. A cylindrical fixed body connected to the lower end of the small-diameter portion and having a large-diameter portion closing the lower-end opening of the main body and a mounting portion connected to the lower end of the large-diameter portion and attached to the container; A fusible member disposed between the small-diameter portion of the fixed body and the main body so as to abut, and movably disposed between the small-diameter portion of the fixed body and the main body such that the upper end abuts on the lower end of the fusible body. Moving body, and a biasing member disposed between the small diameter portion of the fixed body and the main body such that the upper end abuts on the lower end of the moving body and the lower end is received on the upper surface of the large diameter portion of the fixed body. Yes,
The fixed body has an axial passage extending from the middle of the small diameter portion to the lower end of the mounting portion and communicating with the inside of the container, and a radial passage communicating with the upper end of the axial passage and opening on the outer periphery of the small diameter portion. In the peripheral wall of the main body, there is formed an axial passage opening at the upper end thereof and a communication passage communicating with the lower end of the axial passage and opening into the main body and closed by the outer periphery of the moving body. When the moving body moves to the upper position, a radial through passage is provided that communicates the inner end opening of the communication passage of the main body peripheral wall with the radial passage opening of the fixed body,
Thereby, when the fusible body is melted and the moving body moves to the upper position, the gas in the container passes through 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 characterized by being opened to the outside of a container through a passage. The apparatus further includes a cylindrical cap that is placed on the upper end of the main body and has a through hole. 2. The safety valve according to claim 1, wherein the safety valve is discharged outside through the gap and through the through hole.

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