JP2007106262A - Gaseous fuel tank structure for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance safety by preventing fuel gas of a high temperature discharged in a prescribed state from being directly sprayed to a surrounding person, in a gaseous fuel tank 1 constituted to discharge gaseous fuel in the prescribed state. <P>SOLUTION: A front end of a discharge pipe 7 is connected to a main valve 3 of the gaseous fuel tank 1 via a PRD 33. A plurality of slits 71 are formed at intervals in the peripheral direction over the entire periphery in a part of a peripheral wall of a rear end part of the discharge pipe 7. A cover member 72 having a substantial C-shape in cross section is mounted to cover about 2/3 to 4/5 of the slits 71. Since the cover member 72 is made rotatable in the peripheral direction above a slit forming part of the discharge pipe 7 and end parts of the peripheral direction corresponding to both C-end parts are made as each of weight parts, the slits 71 located on a lower side are always opened. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a structure of a gaseous fuel tank that is mounted on a vehicle and stores gaseous fuel, and particularly relates to the technical field of a safety device for preventing the tank from bursting in the event of an accident.

  As this type of vehicular gas fuel tank, a so-called high-pressure gas tank that is generally mounted on a natural gas vehicle and that compresses natural gas and stores it in a predetermined high-pressure state has been widely used. In recent years, with the development of fuel cell vehicles and hydrogen engines, the high-pressure gas tank is used as means for storing hydrogen gas as fuel.

  Such a gaseous fuel tank mounted on a vehicle normally releases gaseous fuel when the temperature around the tank rises above a predetermined level so that it does not rupture even when exposed to high temperatures in the event of a vehicle accident. Equipped with a safety valve to escape.

Such a safety valve is provided with an easily soluble member such as a resin or a eutectic alloy that melts at a predetermined temperature as described in Patent Document 1, for example, and when the temperature around the tank increases, the member melts. Then, the pressure in the tank is released by moving the valve body or by melting the valve body itself made of an easily soluble member.
Japanese Patent Laid-Open No. 10-038113

  By the way, when the safety valve is provided in the gaseous fuel tank mounted on the vehicle as in the conventional example, when the vehicle rolls over due to an accident, the gaseous fuel released from the safety valve as described above is lateral to the vehicle. In addition, there is a possibility that high temperature fuel gas may be blown directly to surrounding people such as rescuers who have blown out upward and rushed to the accident site.

  The present invention has been made in view of such a point, and an object of the present invention is to release the gaseous fuel in the predetermined state as described above in the gaseous fuel tank. It is intended to prevent the high temperature fuel gas from being blown directly to the surrounding people and improve safety.

  In order to achieve the above object, the gaseous fuel tank according to the present invention is configured such that the gaseous fuel is always discharged downward even if the vehicle rolls over due to an accident.

  Specifically, the invention of claim 1 relates to a structure of a gaseous fuel tank that is mounted on a vehicle and stores gaseous fuel, and the gaseous fuel tank contains gas when the ambient air temperature exceeds a predetermined value. A pressure relief device that releases fuel and suppresses an increase in pressure in the tank is attached. The pressure relief device includes a gaseous fuel discharge port, a communication passage that connects the discharge port to the tank, and a gaseous fuel. A passage opening / closing means for closing the communication passage when the air temperature around the tank is lower than a predetermined value and opening the communication passage when the air temperature exceeds a predetermined value; The outlet is provided so that its direction can be changed, and at least provided with a direction changing means for directing the discharge port downward when discharging the gaseous fuel.

  With the above configuration, when the air temperature around the gaseous fuel tank becomes a predetermined value or more due to a vehicle accident, the communication passage of the pressure relief device is opened by the passage opening / closing means, and the interior of the gaseous fuel tank is opened by this communication passage. By communicating with the discharge port and discharging the gaseous fuel, an increase in pressure in the tank is suppressed, and the explosion is prevented in advance.

  At that time, even if the vehicle rolls over, the discharge port of the pressure relief device is directed downward by the direction changing means at least when discharging the gaseous fuel as described above, so the gaseous fuel ejected from the discharge port Does not flow sideways or upward. For this reason, there is no possibility that the high-temperature fuel gas is directly blown to the surrounding rescuer and the safety can be improved.

  According to a second aspect of the present invention, in the same premise configuration as the first aspect of the invention, a plurality of discharge ports of the pressure relief device are provided, and at least when the gaseous fuel is discharged, the plurality of discharge ports are provided in the communication passage. Among them, there is provided a selective communication means for selectively communicating only the direction closest to the vertically lower side to the tank side.

  With this configuration, as in the first aspect of the invention, gaseous fuel can be discharged from the discharge port of the pressure relief device even in the event of a vehicle accident, thereby preventing the gas fuel tank from bursting. Of these, only the one closest to the vertical downward direction is communicated to the tank side by the selective communication means, so even if the vehicle rolls over, the high-temperature fuel gas ejected from the discharge port directly reaches the surrounding people. There is no fear of being sprayed, and safety can be improved.

  As such selective communication means for selectively communicating one of the plurality of discharge ports to the tank side, for example, any one of the passages on the tank side at the branch portion of the communication passage leading to the plurality of discharge ports A switching valve connectable by switching to one branch path and a control means for controlling the switching valve are provided. The vehicle is provided with a sensor for detecting a vertically downward direction, and a signal from the sensor is received. What is necessary is just to comprise so that the said switching valve may be controlled by the received said control means (invention of Claim 3).

  It is particularly preferable to provide the pressure relief device so that the discharge port faces the outside of the vehicle (invention of claim 4), so that even if the vehicle overturns, the high-temperature fuel gas is directly applied to the vehicle body. Since it is not sprayed toward the vehicle, there is no risk of danger even when an occupant is left behind in the passenger compartment.

  The effect of the invention as described above is particularly effective when the gaseous fuel stored in the gaseous fuel tank is hydrogen gas (the invention of claim 5). This is because hydrogen gas has a low specific gravity among the gaseous fuels used as fuel for motors of vehicles, so if it is jetted downward and collides with the ground, etc., it will diffuse quickly and be in a low concentration state without danger Because it can be.

  As described above, according to the gaseous fuel tank structure for a vehicle according to the present invention, when a pressure relief device that releases gaseous fuel in a predetermined state is attached to the gaseous fuel tank mounted on the vehicle, Since the configuration is such that the emitted fuel gas always goes downward, even if the vehicle rolls over or overturns due to an accident, high temperature fuel gas is not directly blown to the surrounding people, improving safety it can.

In particular, when the gaseous fuel discharge port is provided so as to face the outside of the vehicle as in the fourth aspect of the invention, even if the occupant is left behind in the overturned vehicle compartment, there is a risk that the occupant may be at risk. Since there is no, safety can be further improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

(Embodiment 1)
FIG. 1 shows a layout of a fuel supply system in an automobile V equipped with a gaseous fuel tank 1 according to the present invention. In the example shown in the figure, the engine 2 for burning hydrogen gas is mounted in the engine room at the front part of the vehicle body, while the rear part of the vehicle body is separated from the vehicle compartment by a partition wall (not shown) and hydrogen gas as gaseous fuel is, for example, 35 MPa. A fuel tank 1 for storing in a high pressure state is mounted. As the fuel tank 1, for example, a high-pressure gas tank used in a natural gas vehicle, Type 3 that is relatively lightweight and advantageous in preventing hydrogen permeation can be used.

  The fuel tank 1 has a substantially cylindrical shape, and a fuel pipe 4 for supplying hydrogen gas to the engine 2 is connected to a main valve 3 disposed at an end portion in the longitudinal direction. In the middle of the fuel pipe 4, there is a regulator 5 for reducing the hydrogen gas stored in the fuel tank 1 to a predetermined pressure (for example, 0.6 MPa) for supplying to an injector or the like (not shown) of the engine 2. It is installed.

  The main valve 3 is schematically shown in FIG. 2, and includes an electromagnetic valve 31 for supplying hydrogen gas to the engine 2 through the fuel pipe 4 as described above and a hydrogen filling pipe 6 also shown in FIG. And a PRD as a safety valve for releasing hydrogen gas when the fuel tank 1 is exposed to a high temperature and the surrounding temperature becomes higher than a predetermined value. (Pressure Release Device) 33 are integrated with each other, and although not shown, a manual on-off valve, a temperature sensor, a pressure sensor, and the like are provided for shutting off at the time of service.

  As shown in FIG. 1, the PRD 33 is connected to a front end portion of a discharge pipe 7 extending rearward of the vehicle body. A resin (both of which is connected to the passage of the discharge pipe 7 and the tank) melts at a predetermined temperature. When the air temperature around the fuel tank 1 becomes, for example, 110 ° C. or more, the valve body melts and the hydrogen gas in the fuel tank 1 is converted into the hydrogen gas. It discharges to the passage in the discharge pipe 7.

  On the other hand, at the rear end of the discharge pipe 7, as described below, the hydrogen gas discharge port is provided so that it always faces downward, and is discharged from the fuel tank 1 as described above. The hydrogen gas released into the passage in the pipe 7 is always released downward. That is, in this embodiment, when the air temperature around the fuel tank 1 exceeds a predetermined value by the release pipe 7 and the PRD 33 (passage opening / closing means) that opens and closes the passage inside the discharge pipe 7, hydrogen gas is released and the tank A pressure relief device that suppresses an increase in the internal pressure is configured.

  Next, the structure of the rear end portion of the discharge pipe 7 will be described. As shown in an enlarged view in FIG. 3, the rear end portion of the discharge pipe 7 has a cylindrical shape and extends substantially horizontally beyond the rear portion of the vehicle body of the automobile V. The rear end wall 70 extends and the rear end of the passage is closed, and a part of the peripheral wall has a plurality of slit-shaped holes 71, 71,. Is formed over the entire circumference. A cover member 72 having a substantially C-shaped cross section is mounted so as to cover, for example, about 2/3 to 4/5 (at least half or more) of the slits 71, 71,.

  The cover member 72 has a shape obtained by cutting out a part (for example, about 1/3 to 1/5) of a circumferential direction of a metal cylindrical member having a diameter approximately equal to or slightly larger than that of the discharge tube 7, and an inner peripheral surface thereof is The entire cover member 72 is mounted so as to be rotatable around the discharge tube 7 in sliding contact with the outer peripheral surface of the slit forming portion at the rear end portion of the discharge tube 7. The slits 71, 71,... That are not covered by the rotating cover member 72 in this way constitute the discharge port so that hydrogen gas is discharged in a direction orthogonal to the axis of the discharge pipe 7.

  Further, the cover member 72 has circumferential ends corresponding to both ends of the C-shape (parts indicated by hatching in the drawing) made of relatively dense metal (or the outer periphery of the part). The cover member 72 is automatically rotated so that the respective weight portions are positioned at the lower ends of the cover member 72, respectively. Thus, the slits 71, 71,... Located on the upper side and the left and right sides are always covered by the cover member 72, while the slits 71, 71,. .

  That is, the rear end portion of the discharge pipe 7 is provided with a hydrogen gas discharge port (slits 71, 71,...) So that the direction thereof can be changed. In this embodiment, it is configured to always face downward due to gravity. ing. In addition, the direction changing means is configured by the cover member 72 that is rotated and displaced by gravity so that the discharge port always faces downward.

  Therefore, according to the gaseous fuel tank structure for a vehicle according to the first embodiment, even if the fuel tank 1 is exposed to a high temperature due to an accident of the automobile V, for example, the ambient air temperature becomes higher than a predetermined value, The operation of the PRD 33 incorporated in the valve 3 causes the hydrogen gas in the fuel tank 1 to be released into the atmosphere via the discharge pipe 7, thereby suppressing an increase in pressure in the tank and preventing its explosion. .

  At that time, even if the automobile V rolls over due to an accident, only the lower slits 71, 71,... Are always opened at the rear end of the discharge pipe 7, and the rest is covered by the cover member 72. Therefore, the hydrogen gas ejected from the lower slits 71, 71,... Collides with the ground or the like and quickly diffuses to a low concentration state without danger. That is, there is no possibility that the high-temperature hydrogen gas released into the atmosphere through the discharge pipe 7 will be blown out to the side or upward of the automobile V and directly blown to the surrounding rescuers or the like with a relatively high concentration. .

  Moreover, in this embodiment, since the slits 71, 71,... At the rear end of the discharge pipe 7 from which the hydrogen gas is released face the outside of the vehicle as described above, even if the automobile V is overturned, the hydrogen gas is directly , It will not be sprayed on the car body. For this reason, the released hydrogen gas does not fill the passenger compartment, and even if an occupant is left in the passenger compartment of the overturned automobile V, there is no risk that the occupant will be in danger, and the safety is It is extremely expensive.

(Embodiment 2)
FIG. 4 shows the structure of the rear end portion of the discharge pipe 7 in the pressure relief device according to the second embodiment of the present invention. These are configured to be selectively switched. Except for this point, the structure is the same as that of the first embodiment. Therefore, the same members are denoted by the same reference numerals, and the description thereof is omitted. .

  And in this Embodiment 2, as shown to the same figure (a) (b), in the rear-end part of the discharge pipe 7, the 1st, 2nd, and 2nd which branch each into the passage in this discharge pipe 7 is bifurcated, respectively. 3 branch portions s1 to s3 are provided in order from the upstream side, and a three-way valve 73 is provided in each of the branch portions s1 to s3, so that either one of the upstream (tank side) passages is provided. The communication is switched to the downstream passage (branch passage). 2A is a perspective view of the rear end portion of the discharge pipe 7 as viewed from above the automobile V, and FIG. 2B is a perspective view of the left rear side as viewed obliquely from above.

  More specifically, in the example shown in the drawing, the discharge pipe 7 is divided into left and right first and second branch pipes 74 and 75 in the first branch portion s1, and a passage (branch path) in the first branch pipe 74 is included. It reaches the first discharge port 74a toward the left side. On the other hand, the second branch pipe 75 bends in the middle and goes rearward, and the passage inside thereof is further divided into left and right third and fourth branch pipes 76 and 77 in the second branch portion s2.

  The passage in the third branch pipe 76 reaches the second discharge port 76a toward the right side, while the passage in the fourth branch pipe 77 has upper and lower fifth and sixth branch pipes in the third branch portion s3. The passage in the fifth branch pipe 78 that is divided into 78 and 79 and extends upward reaches the third discharge port 78a that opens upward, and the passage in the sixth branch pipe 79 that extends downward opens downward. It reaches the fourth discharge port 79a.

  Further, the three-way valve 73 of each of the branch passages s1, s2,..., For example, as shown in cross section in FIG. The passage is communicated by switching to one of the downstream branch passages. That is, as shown in the figure, if the upstream side passage in the first branch portion s1 communicates with the passage in the first branch pipe 74, the hydrogen gas flows as indicated by the arrow and is discharged from the first discharge port 74a. It becomes like this.

  On the other hand, as shown by the phantom line in the figure, if the upstream passage is communicated with the passage in the second branch pipe 75 in the first branch portion s1, the hydrogen gas flows through the passage in the second branch pipe 75. Thus, when the second branch part s2 is reached and the passage in the second branch pipe 75 communicates with the passage in the third branch pipe 76 in the second branch part s2, the hydrogen gas is released from the second discharge port 76a. Will come to be.

  Similarly, an upstream passage in the first branch portion s1 communicates with a passage in the second branch pipe 75, and a passage in the second branch pipe 75 in the second branch portion s2 is a fourth branch. If the passage in the fourth branch pipe 77 communicates with the passage in the fifth branch pipe 78 in the third branch portion s3, the hydrogen gas is released from the third discharge port 78a. On the other hand, if the passage in the fourth branch pipe 77 communicates with the passage in the sixth branch pipe 79 in the three branch portion s3, the hydrogen gas is released from the fourth discharge port 79a. become.

  The operation of the three-way valve 73 in each of the first to third branch portions s1 to s3 described above is controlled by the controller 8 mounted on the automobile V. That is, in this embodiment, each of the three-way valves 73 is of an electromagnetic drive type, and the valve body 73a is rotated by an electric motor (not shown) that operates in response to a control signal from the controller 8. It has become. The controller 8 receives a signal from an acceleration sensor 81 (a sensor for detecting the vertically downward direction) attached to the main valve 3 of the fuel tank 1 (which may be the vehicle body of the automobile V), for example, While the vehicle is stopped, the first to fourth discharge ports 74a, 76a, 78a, 79a that are closest to the vertically lower side are selected, and the positions of the three-way valves 73 are set so that only the discharge ports communicate with the tank side. Control.

  That is, in the second embodiment, the controller 8 controls the three-way valve 73 while the automobile V is stopped, and only the one of the four outlets 74a, 76a, 78a, 79a whose direction is closest to the vertically downward direction is used. Is selectively communicated with the PRD 33 of the fuel tank 1, and the controller 8 and the three-way valve 73 constitute selective communication means.

  Therefore, according to the gaseous fuel tank structure for a vehicle according to the second embodiment, as in the first embodiment, hydrogen gas can be released from the fuel tank 1 at the time of an accident of the automobile V, and the explosion can be prevented. At the same time, even if the vehicle V rolls over due to an accident, hydrogen gas is released only from the four outlets 74a, 76a, 78a, 79a whose direction is closest to the vertically downward direction. The hydrogen gas thus released collides with the ground or the like and quickly diffuses to a low concentration state without danger.

  That is, as in the first embodiment, there is no possibility that the high-temperature hydrogen gas released into the atmosphere through the discharge pipe 7 is directly blown to the surrounding human being with a relatively high concentration.

  Also in the second embodiment, as described above, the four discharge ports 74a, 76a, 78a, and 79a from which hydrogen gas is discharged face the outside of the vehicle, so that even if the automobile V overturns, There is no direct spray on the car body, so safety is extremely high.

  Furthermore, in the second embodiment, the three-way valve 73 is controlled in accordance with the signal from the acceleration sensor 81 so that the flow path of the hydrogen gas at the rear end of the discharge pipe 7 is switched. Thus, the above-mentioned effects can be obtained more reliably.

(Other embodiments)
In addition, the specific structure of this invention is not limited to the thing of the said Embodiment 1, 2, and various other structures are included. That is, in the first embodiment, as described above, the hydrogen gas discharge ports (slits 71, 71,...) Are configured to always face downward due to gravity. As in the second embodiment, the cover member 72 can be rotated by an electric motor using the acceleration sensor 81 and the controller 8, so that the discharge port can be directed downward.

  In the second embodiment, the controller 8 controls the three-way valve 73 while the automobile V is stopped so that only the discharge port closest to the vertically lower side is selectively communicated to the tank side. For example, it may be performed only when hydrogen gas is released from the PRD 33 based on a signal from the temperature sensor of the main valve 3. However, since the acceleration sensor 81 may be erroneously detected while the automobile V is traveling, it is preferable to perform detection in the vertically downward direction while the vehicle is stopped.

  In the first and second embodiments, the example in which the gaseous fuel tank structure of the present invention is applied to a hydrogen engine vehicle has been shown, but the present invention is also applicable to, for example, a fuel cell vehicle using hydrogen as fuel, Furthermore, the present invention can be applied to, for example, a natural gas vehicle using a gaseous fuel other than hydrogen gas.

  The present invention relates to a structure of a gaseous fuel tank mounted on a vehicle. In the event of an accident, the fuel tank can be prevented from rupturing, and even if the vehicle rolls over and overturns, high-temperature fuel gas is transferred to surrounding people. Since it is not sprayed, it is extremely safe and particularly suitable for mounting on a passenger car.

It is a schematic diagram which shows the layout of the fuel supply system in the motor vehicle carrying the gaseous fuel tank which concerns on this invention. It is a schematic diagram which shows the structure of the main valve of the gaseous fuel tank FIG. 3 is a perspective view illustrating a configuration of a rear end portion of the discharge tube according to the first embodiment. It is a figure which shows the structure of the discharge pipe rear end part of Embodiment 2, (a) is a top view, (b) is a perspective view, (c) is sectional drawing of a three-way valve.

Explanation of symbols

V Automobile (vehicle)
1 Gas fuel tank 3 Main valve 33 PRD (passage opening / closing means: pressure relief device)
7 Release pipe (pressure relief device)
71 Slit (Discharge port)
72 Cover member (direction changing means)
73 Three-way valve (Switching valve: Selection communication means)
8 Controller (Control means: Selection communication means)
81 Acceleration sensor

Claims (5)

A structure of a gaseous fuel tank that is mounted on a vehicle and stores gaseous fuel,
The gas fuel tank is equipped with a pressure relief device that releases the gas fuel when the ambient air temperature becomes a predetermined value or more, and suppresses the pressure rise in the tank,
The pressure relief device includes:
A gaseous fuel discharge port, and a communication passage communicating the discharge port into the tank;
A passage opening and closing means that closes the communication passage when the air temperature around the gaseous fuel tank is less than a predetermined value, and opens the communication passage when the air temperature becomes a predetermined value or more,
The discharge port of the pressure relief device is provided so that the direction can be changed,
A vehicular gaseous fuel tank structure characterized in that direction changing means for directing the discharge port downward is provided at least when discharging gaseous fuel. A structure of a gaseous fuel tank that is mounted on a vehicle and stores gaseous fuel,
The gas fuel tank is equipped with a pressure relief device that releases the gas fuel when the ambient air temperature becomes a predetermined value or more, and suppresses the pressure rise in the tank,
The pressure relief device includes:
A gaseous fuel discharge port, and a communication passage communicating the discharge port into the tank;
A passage opening and closing means that closes the communication passage when the air temperature around the gaseous fuel tank is less than a predetermined value, and opens the communication passage when the air temperature becomes a predetermined value or more,
A plurality of discharge ports of the pressure relief device are provided,
The communication path is provided with selective communication means for selectively communicating only the one of the plurality of discharge ports whose direction is closest to the vertically lower side to the tank side at least when discharging gaseous fuel. A gas fuel tank structure for vehicles. In the gaseous fuel tank structure for vehicles of Claim 2,
The vehicle is provided with a sensor for detecting the vertical downward direction,
The selection communication means includes
A switching valve connectable by switching the tank-side passage to any one of the branch passages at the branch portion of the communication passage leading to the plurality of discharge ports;
And a control means for controlling the switching valve in response to a signal from the sensor. In the gaseous fuel tank structure for vehicles in any one of Claims 1-3,
A gaseous fuel tank structure for a vehicle, wherein a discharge port of the pressure relief device is provided facing the outside of the vehicle. In the gaseous fuel tank structure for vehicles in any one of Claims 1-4,
A gaseous fuel tank structure for vehicles, wherein the gaseous fuel is hydrogen gas.

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