JP4873156B2 - Melting plug - Google Patents

Description

  The present invention relates to a plug used for, for example, a pressure vessel, and relates to a plug capable of releasing, for example, gas inside the pressure vessel to the outside by melting a soluble material.

  As this type of plug, for example, the one described in Patent Document 1 is known. The plug includes a plug body that is installed so as to airtightly close an opening provided in the partition wall of the pressure vessel, a soluble ring incorporated in a piston housing hole in the center of the plug body, a piston, a spring, and a lid, Etc. The gas in the pressure vessel flows into the piston housing hole from the opening formed in the lid. When the gas becomes hot, the fusible ring melts and the piston is actuated by the biasing force of the spring.

  In the pressure vessel described in Patent Document 1, an open air communication hole communicating with the piston housing hole is formed in the plug body. Normally, the outside air communication hole is separated from the space on the lid body side in the piston housing hole by the piston. On the other hand, when the fusible ring is melted by the temperature rise of the gas, the piston is operated to communicate the outside air communication hole with the space on the lid body side, and further communicate with the inside of the pressure vessel through the opening formed in the lid body. Therefore, the gas in the pressure vessel can be released out of the pressure vessel through the outside air communication hole.

In the configuration described in Patent Document 1, the melting of the soluble ring is caused by direct exposure to a high-temperature gas rather than heat transfer from the surrounding metal or the like. For this reason, the responsiveness of the plug to the temperature rise in the pressure vessel, that is, the operation sensitivity of the plug is improved.
JP-A-2005-147385

  However, in the configuration described in Patent Document 1, although the responsiveness to the temperature rise of the gas in the pressure vessel is improved, the responsiveness to the temperature rise outside the pressure vessel has not been improved. In addition, there is a possibility that the stopper main body is damaged by an impact when the piston is operated.

  An object of the present invention is to provide a fusing plug that is not easily damaged during operation.

In order to achieve the above-mentioned object, the fusing plug of the present invention includes a housing attached to a communication portion that communicates the inside and outside of a gas facility whose internal pressure is higher than the external pressure. The housing includes a working space, a communication passage that communicates the working space and the inside of the gas facility, and a gas discharge port that communicates the working space and the outside of the gas facility. The fusing plug further includes a fusible body that is provided in contact with the housing and melts at a predetermined temperature, and a movable body that is accommodated in the working space. The movable body is restricted in movement by the soluble body before the fusible body is melted, and closes the communication path. After the fusible body is melted, the movable body is moved by releasing the restriction to open the communication path. The housing has a collision portion that collides with the movable body after melting the fusible body, and the collision portion is formed as a thin protrusion on a part of the housing, and is deformed by the collision of the movable body, Mitigates the impact when a movable body collides .

  According to such a configuration, the movable body is moved by melting the fusible body and the communication path communicating with the gas facility is opened, so that the gas is discharged from the gas facility to the outside of the gas facility in response to the temperature rise. be able to. Since the fusible body is provided in contact with the housing, the heat can be suitably transferred from the housing to the fusible body when the ambient temperature outside the gas equipment rises. In addition, the movable body collides with the collision portion of the housing when the fusing plug is operated. At this time, the impact at the time of the collision applied to the housing is mitigated by the impact mitigation portion. Therefore, the housing is less likely to be damaged during operation.

Further, since the impact at the time of the collision of the movable body can be reduced by the deformation of the collision portion , the housing is not easily damaged.

Furthermore, since the collision part is formed as a thin protrusion on a part of the housing, it can be easily deformed by an impact and can be mitigated.

  More preferably, the housing has an opening on a movable path of the movable body, and communicates the inside of the working space with the outside of the gas facility. Before the meltable body is melted, one end closes the opening and the other end abuts on the movable body to restrict its movement. The thin protrusion is formed by making the tip side of the edge of the opening thinner than the base side.

  According to such a configuration, when the melt plug is operated, the movable body that has been operated on the opening side collides with the thin protrusion formed on the edge of the opening, so that the impact is mitigated. Since the thin protrusion in the above-described manner is formed, the thin protrusion can be easily formed on the edge of the opening. Further, since the thin projection is formed at the edge of the opening, the deformation of the thin projection can be confirmed at a glance from the outside of the housing, so that it is possible to easily confirm that the melting plug has been activated.

  More preferably, the movable body has a tapered portion that collides with the thin projection and closes the opening after the fusible body is melted.

  Preferably, the housing is made of a copper alloy.

  According to such a configuration, since the heat conductivity of the housing is high, the temperature rise of the fusible body in contact with the housing is quick. Therefore, the soluble material can be rapidly melted at the time of temperature rise, and the gas can be quickly released. That is, the operational sensitivity of the plug is improved.

  According to the melt plug of the present invention, the impact during operation is alleviated and damage is reduced.

  Hereinafter, with reference to the accompanying drawings, a melting plug according to a preferred embodiment of the present invention will be described. The fusing plug according to the present invention is applicable to a gas facility having a high-pressure gas container or a gas flow path, and is used, for example, in a fuel gas storage device, a refrigeration device, a hot water supply facility, an air conditioning facility, or the like. Here, as a plug provided in the gas facility, a high-pressure tank plug for storing fuel of the fuel cell will be described as an example.

<First Embodiment>
FIG. 1 is a view showing a fuel cell vehicle equipped with a high-pressure tank equipped with a fusing plug according to the present embodiment as part of a gas facility for supplying fuel gas.
The fuel cell vehicle 100 is equipped with a fuel cell system 200. In the fuel cell system 200, for example, three high-pressure tanks 1 are mounted on the rear part of the vehicle body. The fluid in each high-pressure tank 1 is a combustible fuel gas such as hydrogen gas or compressed natural gas, and is supplied to the fuel cell 104 through the gas supply line 102.

  The fuel gas is stored in the high-pressure tank 1 at a pressure (that is, a high pressure) higher than the normal pressure. For example, 35 MPa or 70 MPa hydrogen gas or 20 MPa compressed natural gas is stored. Below, hydrogen gas is demonstrated to an example as fuel gas which the high pressure tank 1 stores. Note that the high-pressure tank 1 can be applied not only to fuel cell vehicles but also to vehicles such as electric vehicles and hybrid vehicles, as well as various moving bodies (for example, ships, airplanes, robots, etc.) and stationary types.

FIG. 2 is a cross-sectional view showing a main part of the high-pressure tank 1.
The high-pressure tank 1 includes a sealed cylindrical tank body 2 as a whole. The end of the tank body 2 in the longitudinal direction is formed in a dome shape, and a base 3 is attached to the top. A valve assembly 4 is screwed to the base 3. The valve assembly 4 is attached with a fusing plug 5.

  The tank body 2 has a two-layer structure of, for example, a resin liner 10 and a CFRP layer 12. The resin liner 10 has a return portion 11 formed at one end portion or both end portions in the longitudinal direction of the tank body 2. The CFRP layer 12 is an FRP layer formed by reinforcing a matrix resin (plastic) with carbon fibers.

  The base 3 includes an opening 30 having an axial center on the axis YY of the tank body 2. The inner peripheral surface of the opening 30 includes a female screw 31 for screwing and connecting the valve assembly 4 and a stopper, and a seal surface 34 that is axially sealed between the valve assembly 4 by seal members 32 and 33. .

  The valve assembly 4 includes a gas supply / discharge passage 41 that can be connected to an external gas supply line 102. The gas supply / discharge passage 41 communicates with the storage space 6 inside the high-pressure tank 1 and constitutes a flow path for hydrogen gas supplied to and discharged from the high-pressure tank 1. The body 40 of the valve assembly 4 is made of a metal such as stainless steel, preferably the same aluminum or aluminum alloy as the base 3. The valve assembly 4 has a branch passage 42 connected to the gas supply / discharge passage 41. The branch passage 42 opens on the outer peripheral surface of the valve assembly 4. The opening position constitutes a communication portion 43 that communicates the inside and outside of the high-pressure tank 1, and the fusing plug 5 is attached to this communication portion 43.

  The melt plug 5 closes the end of the branch passage 42 under a normal temperature environment. However, when the atmospheric temperature rises due to the high-pressure tank 1 being exposed to a high temperature environment or the like, the fusing plug 5 automatically communicates the branch passage 42 with the outside and releases the internal hydrogen gas to the outside.

FIG. 3 is a cross-sectional view of the fusing plug 5. This figure shows the state of the melt plug 5 when the high-pressure tank 1 is in a normal temperature environment and the end of the branch passage 42 is closed.
The fusing plug 5 is in contact with the fusing body 5A, which is a housing surrounding the outside, a piston-like disk 5B (movable body) disposed inside the fusing body 5A, and the distal end surface of the disk 5B. A soluble alloy plate 5C (soluble body) that regulates The interior of the fusing plug body 5A is hollow, and a working space 5D is formed.

  The melt plug body 5A is fixed to a substantially flat plate-like flange portion 51, an insertion portion 52 formed to project from the approximate center of the flange portion 51 toward the branch passage 42, and a plate surface opposite to the insertion portion 52. And a cup-shaped lid portion 53. The working space 5D is a space surrounded by the flange portion 51 and the lid portion 53, and a disk 5B and a soluble alloy plate 5C are accommodated therein.

  The flange portion 51 is in contact with the outer peripheral surface of the body 40. The insertion part 52 is inserted into the end of the branch passage 42. The insertion portion 52 has a communication passage 55 having an axial center on the axis ZZ of the branch passage 42. The communication passage 55 is a linear through hole that penetrates the insertion portion 52, and one end of the communication passage 55 is communicated with the substantially central opening of the flange portion 51. Therefore, the working space 5 </ b> D communicates with the inside of the high-pressure tank 1 through the communication passage 55.

  As for the insertion part 52, the thread part 52a is formed in the outer peripheral surface by the side of the flange part 51. As shown in FIG. The screw plug body 5 </ b> A is attached to the end of the branch passage 42 by screwing and connecting the screw portion 52 a to the female screw on the inner peripheral surface of the branch passage 42. The distal end side of the insertion portion 52 is reduced in diameter, and the space between the outer peripheral surface on the distal end side and the inner peripheral surface of the branch passage 42 is sealed with a seal member. The melt plug body 5A is attached to the communication portion 43 in this way.

  The lid 53 has an opening 54 formed at the center of the top surface. An annular thin protrusion 54 a is formed at the edge of the opening 54. The thin projection 54 a is formed by making the distal end side of the edge of the opening 54 thinner than the proximal end side. The thin projection 54a is formed in a collision portion that collides with the disk 5B after the melting of the fusible alloy plate 5C, and functions as an impact relaxation portion that reduces the impact caused by the collision. Inside the lid 53, a soluble alloy plate 5 </ b> C having a larger plate area than the opening 54 is inscribed, and the soluble alloy plate 5 </ b> C completely closes the opening 54. In addition, a gas discharge port 58 that communicates the working space 5D and the outside is formed on the side surface of the lid portion 53.

  The disk 5B has a reduced diameter portion 56 that has a diameter reduced stepwise at one end thereof. The reduced diameter portion 56 is fitted into the opening of the flange portion 51. Since the reduced diameter portion 56 is inserted into the communication path 55 and sealed with the shaft, the communication path 55 is hermetically closed by the disk 5B. On the other hand, the other end of the disk 5B is reduced in diameter to have a sloped tapered portion 57.

  In a normal temperature state, the disk 5B is sandwiched between the fusible alloy plate 5C and the flange portion 51 so as not to move. That is, the movement of the disk 5B in the direction of releasing the blockage of the communication path 55 is restricted by the fusible alloy plate 5C. Although the fusible alloy plate 5C and the disk 5B are not completely fixed at this position, they do not come out of this position because they are in contact with each other by the internal pressure of the high-pressure tank 1.

The plug body 5A is formed using C3604B which is a copper alloy. Copper alloys such as C3604B have significantly higher thermal conductivity than stainless steel such as SUS316. Therefore, by using C3604B, the heat transfer speed to the fusible alloy plate 5C at the time of temperature rise is increased, and the operation sensitivity of the plug 5 is improved. Table 1 shows physical property values of C3604B and SUS316.

  However, while C3604B has a high thermal conductivity, the yield strength upon impact is lower than that of SUS316. In particular, the decrease in yield strength at high temperatures is significant. Therefore, when C3604B is used, it is necessary to consider a decrease in yield strength under this high temperature environment. In the present embodiment, as will be described below, the thin protrusion 54a described above is caused to function as an impact relaxation portion so as to cope with a decrease in yield strength by impact relaxation.

  The fusible alloy plate 5C is formed using a low melting point alloy such as solder. Note that a soluble material other than metal may be used instead of the soluble alloy plate 5C. For example, a soluble material such as wax may be used. The fusible alloy plate 5 </ b> C is constantly pressed by the disk 5 </ b> B that has received the gas pressure from the communication passage 55 side, and is in close contact with the inner wall surface of the lid 53. Therefore, it is desirable to use a material that is not easily deformed even in a constant pressure receiving state.

  When the high-pressure tank 1 is exposed to a high temperature environment or is heated due to internal heat generation or the like, the temperature of the fusing plug body 5A is increased by high-temperature outside air or heat conduction from the valve assembly 4 side. . Further, the temperature of the disk 5B is raised by heat conduction from the hot gas side that has entered the plug body 5A and the branch passage 42. Therefore, the fusible alloy plate 5C is heated by heat conduction from these adjacent members and melted when the temperature reaches a predetermined temperature.

FIG. 4A is a cross-sectional view for explaining the operation of the melting plug 5 according to this embodiment. Moreover, FIG.4 (b) is sectional drawing explaining operation | movement of the melting plug which concerns on a comparative example.
When the fusible alloy plate 5C is removed from between the opening 54 and the disk 5B by melting, the disk 5B can move to the opening 54 side. Therefore, the disk 5B jumps out to the opening 54 side at a speed corresponding to the gas pressure received at the end surface on the communication path 55 side which is the pressure receiving surface. As a result, the communication path 55 is opened, and the gas in the high-pressure tank 1 is released from the communication path 55 to the outside via the gas discharge port 58. The opening 54 is closed by the taper portion 57 of the protruding disk 5B.

  In the plug 5 of the present embodiment, the time until the soluble alloy plate 5C is melted by heat conduction is obtained by using C3604B, which is a copper alloy having a high heat transfer speed, as the material of the plug body 5A. Compared with the case of using a stainless steel alloy such as SUS316, it is greatly shortened. Therefore, the time required from when the temperature rises until the disk 5B is activated is shortened, and the operation sensitivity of the fusing plug 5 is improved.

  The center of the disk 5B is located on the axis ZZ. Similarly, the center of the opening 54 is located on the axis ZZ. That is, the opening 54 is an opening on the movable path of the disk 5B. When the disk 5B jumps out to the opening 54 side, the reduced diameter portion at the tip passes through the opening 54, but the tapered portion 57 collides with the thin projection 54a which is a collision portion on the fusing body 5A side. Therefore, the disk 5B stays in the working space 5D without completely popping out of the plug body 5A during operation.

  In the activated disk 5B, the tapered portion 57 collides with the thin projection 54a with a predetermined impact force according to the gas pressure. Then, the thin projection 54a is bent and deformed outward by this impact force as shown in FIG. In addition, since the collision location on the disk 5B side is formed in a taper shape, the thin projection 54a is smoothly bent and deformed outward.

  In this way, the kinetic energy of the disk 5B during operation is converted into a work that deforms the thin projection 54a, so that the impact force shared by other parts of the plug body 5A is reduced by the thin projection 54a. Decrease by minutes. Therefore, even if the plug body 5A is formed of a metal whose yield strength is reduced at a high temperature, such as C3604B, it is possible to suppress deformation and breakage in a portion other than the thin projection 54a. The melting of the fusible alloy plate 5C and the deformation of the thin projection 54a can be easily confirmed from the outside through the opening 54. Therefore, it can be easily confirmed that the melt plug 5 has been activated.

  On the other hand, as shown in FIG. 4B, in the case of the plug 500 in which the impact mitigating portion such as the thin protrusion 54a is not provided in the collision portion 510, the full impact force is not buffered and the plug body Acts on 500A. For this reason, there is a high possibility that large damage will occur in the plug body 5A.

  Note that the shape of the impact relaxation portion is not limited to the shape of the thin protrusion 54a. The point is that the impact mitigating part may be provided on a position where it can collide with the disk 5B on the operating path of the disk 5B protruding to the opening 54 side, and if it is a protrusion that can be deformed by the collision. Good. Further, a friction surface may be provided as an impact relaxation part, and the impact may be reduced by converting the impact force at the time of collision into frictional heat.

<Second Embodiment>
FIG. 5 shows another embodiment in which the operation sensitivity is improved. The difference between the plug 600 of the present embodiment and the plug 5 of the first embodiment is that the plug 600 uses a plug body 600A having a thinner material instead of the plug body 5A, and The material of the plug body 600A is SUS316. By reducing the material thickness, the heat transfer rate of the plug body 600A using SUS316 having a thermal conductivity lower than that of C3604B or the like is improved. Therefore, in the plug 600, like the plug 5 of the above-described embodiment, the time until the soluble alloy plate 5C is melted by heat conduction is shortened, and the operation sensitivity is improved. .

  The strength of the plug 600 is reduced by reducing the material thickness. Therefore, in order to compensate for this strength reduction and suppress the breakage, the plug body 600A is provided with the same configuration as the opening 54 and the thin projection 54a as an impact relaxation portion. If it does in this way, an impact will be relieved by the deformation | transformation of a thin-shaped protrusion at the time of an action | operation.

<Third Embodiment>
Next, with reference to FIG. 6, the plug 700 according to the third embodiment will be described focusing on the differences. The difference from each of the above embodiments is that, in this embodiment, an impact mitigating portion is provided on the disk 700B side which is a movable body, not on the side of the plug body 5A or the plug body 600A.

  As shown in FIG. 6A, the plug body 700A has an opening 701 on its top surface. A tapered portion 701 a that functions as a collision portion is formed on the inner side of the inner peripheral surface of the opening 701. On the other hand, the disc 700B has a diameter that is reduced to a size that allows the end on the opening 701 side to pass through the opening 701, and a diameter that the center in the length direction cannot pass through the opening 701. Further, a thin protrusion 702 is formed on the disk 700B at a predetermined position near the end on the opening 701 side. The thin protrusion 702 extends with a predetermined thickness toward the radially outer side.

  FIG. 6B shows a state of the melting plug 700 during operation. As in the above embodiments, when the movable restriction of the disc 700B is released by melting the fusible alloy plate 700C, the disc 700B jumps out toward the top surface side of the plug body 700A. At this time, the tip of the disc 700B passes through the opening 701, but the thin projection 702 and the tapered portion 701a collide with each other with a predetermined impact force corresponding to the gas pressure. The thin projection 702 is bent and deformed toward the inner side of the plug body 700A by this impact force. Since the edge of the opening 701 is tapered, the thin projection 702 is smoothly bent and deformed. Then, the opening 701 is closed by the bent thin projection 702 and the enlarged diameter portion therebelow.

  As described above, the impact relaxation portion (thin-walled protrusion 702) may be provided not on the housing side of the fusing plug but on the movable body side. Even with such a configuration, the deformation of the thin projection 702 can alleviate the impact on the plug body 700A due to the collision of the disk 700B, and the damage to the plug body 700A can be reduced.

It is a figure which shows the fuel cell vehicle carrying a pressure vessel. It is sectional drawing which shows the principal part of the pressure vessel which attached the melting plug which concerns on embodiment. It is sectional drawing which shows the melting plug which concerns on embodiment. It is a figure explaining operation | movement of a melting plug, (a) is sectional drawing of the melting plug which concerns on this embodiment, (b) is sectional drawing of the melting plug which concerns on a comparative example. It is sectional drawing which shows the melting plug which concerns on 2nd Embodiment. It is a figure which shows the melting plug which concerns on 3rd Embodiment, (a) is sectional drawing which shows the state before fusion | melting, (b) is sectional drawing which shows the state after fusion | melting.

Explanation of symbols

1: high pressure tank (pressure equipment), 5: fusing plug, 5A: fusing body (housing), 5B: disk (movable body), 5C: fusible alloy plate (fusible body), 5D: working space, 42: branch Passage, 43: communication portion, 54: opening, 54a: thin projection (impact mitigation portion), 55: communication passage, 57: taper portion, 58: gas discharge port

Claims (4)

A housing attached to a communication portion that communicates the inside and outside of a gas facility whose internal pressure is higher than the external pressure, the working space, a communication passage that connects the working space and the gas facility, the working space, and the gas A housing having a gas discharge port communicating with outside the facility;
A fusible body provided in contact with the housing and melted at a predetermined temperature;
A movable body accommodated in the working space, wherein the movable body is restricted by the soluble body before the melting of the fusible body and closes the communication path, and after the fusible body is melted, the restriction is released. A movable body that moves and opens the communication path;
A fusing plug comprising:
The housing has a collision portion that is collided with the movable body after melting the fusible body,
The said collision part is formed as a thin protrusion in a part of the housing, and is deformed by the collision of the movable body, thereby mitigating the impact at the time of the collision of the movable body . The housing is
An opening on the movable path of the movable body, the opening communicating the inside of the working space and the outside of the gas facility;
The fusible body has its one end closed the opening and the other end is in contact with the movable body and regulates its movement before melting.
The plug according to claim 1 , wherein the thin protrusion is formed by making the tip side of the edge of the opening thinner than the base side. The said movable body is a melting plug of Claim 2 which has a taper part which collides with the said thin-shaped protrusion after the said meltable body fuse | melts, and obstruct | occludes the said opening. The melting plug according to any one of claims 1 to 3 , wherein the housing is formed of a copper alloy.

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