JP4375233B2 - Vehicle equipped with gas fuel tank - Google Patents

Description

  The present invention relates to a vehicle equipped with a gas fuel tank.

In recent years, low-pollution vehicles equipped with a gas fuel tank filled with high-pressure gas fuel are known. For example, Patent Document 1 discloses a bus equipped with a CNG cylinder filled with compressed natural gas (CNG) as gas fuel. In this bus, a cylinder storage space for storing a CNG cylinder is formed by a roof cover covering the roof, and a gap is provided between the front lower edge portion of the roof cover and the roof. When this bus travels, air flows into the cylinder storage space through the gap, and the air that has passed through the cylinder storage space flows out from the air outflow portion provided on the rear surface of the roof cover.
JP 2000-127860 A

  However, assuming that the gas fuel leaks from the gas fuel tank for some reason, it is preferable to discharge the gas fuel accumulated in the cylinder storage space at an early stage. However, in Patent Document 1 described above, the bus is not traveling. In this case, the gas fuel collected in the cylinder storage space is difficult to flow, so the gas fuel could not be discharged early.

  This invention is made | formed in view of this subject, and it aims at providing the gas fuel tank mounting vehicle which can discharge | emit the gas fuel collected in the tank storage space at an early stage.

  The present invention adopts the following means in order to achieve the above-mentioned object.

That is, the vehicle equipped with the gas fuel tank of the present invention is
A vehicle equipped with a gas fuel tank,
A roof cover provided so as to cover the roof and forming a tank storage space capable of storing one or more of the gas fuel tanks;
A ventilation opening provided at a position on the upper surface of the roof cover and above the gas fuel tank;
It is equipped with.

  In this vehicle equipped with a gas fuel tank, the gas fuel filled in the gas fuel tank has a specific gravity smaller than that of air, such as CNG (mainly methane) or hydrogen. For this reason, when the fuel gas leaks from the gas fuel tank for some reason, the fuel gas is lighter than the air, so the tank storage space rises and is formed at a position on the upper surface of the roof cover that is above the gas fuel tank. It quickly reaches the ventilation port and efficiently flows out from there. Therefore, the fuel gas accumulated in the tank storage space can be discharged early. Here, examples of the vehicle include buses, large passenger cars, automobiles such as small passenger cars, and trains.

  In the gas fuel tank-equipped vehicle of the present invention, the ventilation port may be provided at a plurality of locations on the upper surface of the roof cover and at positions above the gas fuel tank. By doing so, the gas fuel in the tank storage space flows out from the nearest ventilation port among the ventilation ports provided at a plurality of locations, and therefore flows out more efficiently.

  In the gas fuel tank-equipped vehicle of the present invention, the ventilation port may be formed of a slit group formed by spanning a plurality of louvers at intervals in an opening provided in the roof cover. By doing this, the louver plays a role of protecting the gas fuel tank from flying stones, sunlight rays, and the like, so that the durability of the gas fuel tank is improved as compared with the case where the ventilation port is simply opened.

  At this time, the louver may be a member including an inclined portion inclined with respect to a horizontal plane and a horizontal portion connected to at least one end of the inclined portion and formed substantially horizontally. In this way, the horizontal portion of the louver prevents stepping stones or the like from directly hitting the gas fuel tank, and the inclined portion of the louver prevents direct sunlight from hitting the gas fuel tank. The louver may be a member having a substantially Z-shaped cross section in which a horizontal portion is connected to both ends of the inclined portion. In this way, the protection function of the gas fuel tank by the louver is further enhanced. Moreover, you may make it the inclination part of a louver incline at an angle of 10-40 degrees with respect to a horizontal surface. In this way, the sunlight during the day can be prevented from almost hitting the gas fuel tank.

  In the vehicle equipped with the gas fuel tank of the present invention, the ventilation port may be a gap formed so as to extend in the front-rear direction on both the left and right sides of the roof cover.

  In the gas fuel tank-equipped vehicle of the present invention, the total opening area of the ventilation port may be determined based on at least the volume of the tank storage space. For example, the total opening area of the ventilation port may be increased as the volume of the tank storage space is increased. If it carries out like this, the pressure of a tank storage space will be easy to escape via a ventilation opening. As a parameter for determining the total opening area of the ventilation port, the volume of the tank storage space includes at least one of the number of gas fuel tanks, the capacity of the gas fuel tank, the internal pressure of the gas fuel tank, and the temperature of the tank storage space. One parameter may be added. Further, the total opening area may be the sum of the ventilation ports provided at a plurality of positions on the upper surface of the roof cover and above the gas fuel tank and other ventilation ports (for example, the above-described slits).

  The vehicle equipped with the gas fuel tank of the present invention may be provided with a lid member which is attached to the roof cover so as to be opened and closed and which is opened from the closed state when the tank storage space reaches a predetermined pressure exceeding the atmospheric pressure. Good. Here, the predetermined pressure is a pressure arbitrarily determined within a range exceeding the atmospheric pressure, and may be determined to be less than the maximum pressure in the assumed tank storage space, for example.

  In this gas fuel tank-equipped vehicle, even if the tank storage space exceeds the atmospheric pressure and reaches a predetermined pressure for some reason, the pressure in the tank storage space decreases because the lid member changes from the closed state to the open state. Therefore, it is possible to avoid the tank storage space from becoming a high pressure exceeding a predetermined pressure.

  Here, the lid member may be attached with lower strength on the sidewalk side than on the roadway side. Further, the lid member may be attached so that the sidewalk side is opened when the closed state is changed from the closed state to the open state. Furthermore, the lid member may be attached such that the end portion on the sidewalk side rises with the end portion on the roadway side as an axis. In these cases, the opened lid member does not fall into the entrance / exit. The lid member may be attached to the vehicle or the roof cover via a regulating member that prevents the lid member from being detached from the vehicle when the closed state is changed to the opened state. In this way, the opened lid member does not come off the vehicle. This regulating member may function so that the lid member that has been opened from the closed state stays on the roof. In this way, the opened lid member does not fall to the ground. Further, the lid member is elastically supported so as to change from a closed state to an open state according to an internal pressure of the tank storage space, or an opening after being opened according to an internal pressure of the tank storage space. You may be elastically supported so that an area may change.

  Next, the best mode for carrying out the present invention will be described below with reference to the drawings. 1 is a left side view of the fuel cell bus 10, FIG. 2 is a perspective view of the upper portion of the fuel cell bus 10, FIG. 3 is a rear view (fracture sectional view) of the fuel cell bus 10, and FIG. 4 is a perspective view of a cover center upper surface member 34. FIG.

  As shown in FIG. 1, the fuel cell bus 10 of the present embodiment has passengers in a passenger cabin 16 via a front entrance 12 provided in front of the left side and a central entrance 14 provided in the center of the left side. It is configured as a low-floor large bus for getting on and off, and does not have an entrance on the right side of the vehicle. The fuel cell bus 10 is equipped with seven hydrogen cylinders 18 as gas fuel tanks at the top, and a fuel cell stack 20 in which several hundred fuel cells are stacked at the rear and various auxiliary equipments 22 related to the fuel cells. In the fuel cell stack 20, hydrogen (fuel gas) is supplied from the hydrogen cylinder 18 to the anode side, and air (oxidizing gas) is supplied to the cathode side from an air compressor that is one of the auxiliary machines 22. Power is generated by an electrochemical reaction between hydrogen and oxygen contained in the air. When the fuel cell bus 10 is traveling normally, a motor (not shown) rotationally drives the wheels by the generated power.

  Next, the configuration of the upper part of the fuel cell bus 10 will be described in detail below. As shown in FIG. 2, the fuel cell bus 10 forms, on the upper roof 10a, seven hydrogen cylinders 18 fastened and fixed by metal bands 26, and a cylinder storage space for storing the hydrogen cylinders 18. The roof cover 30 has a ventilation port 40 provided at a position on the upper surface of the roof cover 30 and above the hydrogen cylinder 18.

  The hydrogen cylinder 18 is, for example, a cylindrical container containing high-pressure hydrogen gas of 35 MPa, and is placed in a state where a pair of rails 24, 24 extending in the front-rear direction are bridged on the left and right sides of the roof 10 a. The metal band 26 fixed to the rail 24 is wound and fastened. As a result, the hydrogen cylinder 18 is not misaligned during traveling. This hydrogen cylinder 18 is connected to the anode side of the fuel cell stack 20 by gas piping. In addition, an on-off valve and a pressure reducing valve (not shown) are arranged in the middle of the gas pipe.

  The roof cover 30 covers the entire roof of the fuel cell bus 10 to form an upper space. In the upper space, a cylinder storage space for storing seven hydrogen cylinders 18 and a storage space for other devices are stored. included. As shown in FIG. 1, the roof cover 30 includes a streamlined cover front portion 31 that covers a roof front portion where the air conditioner unit 28 is disposed, and a cover central portion that covers a roof central portion where a plurality of hydrogen cylinders are disposed. 32 and a cover rear portion 39 covering the roof rear portion where the radiator 21 for radiating the cooling water for cooling the fuel cell stack 20 is disposed.

  Here, as shown in FIG. 3, the cover center portion 32 of the roof cover 30 includes a pair of cover center side members 33, 33 erected on the left and right sides of the fuel cell bus 10, and the pair of cover center side members. Four cover center upper surface members 34, 34, 34, 34 connected to the upper ends of 33, 33 are provided. Each cover central side member 33 is formed so as to be substantially flush with the side surface of the fuel cell bus 10, and is bent from the upper end of the standing wall 33a toward the vehicle center so as to be substantially parallel to the roof 10a. And a formed flange 33b. Further, as shown in FIG. 3, the standing wall portion 33a is in contact with a pedestal 35 that protrudes laterally from the side of the body of the fuel cell bus 10 as shown in FIG. Are screwed into bolt holes (not shown) formed in As a result, the standing wall 33a of the cover center side member 33 is spaced from the body side of the fuel cell bus 10 by a height H1 (several mm) of the pedestal 35 to form a gap 47. The gap 47 extends in the front-rear direction of the vehicle on both the left and right sides of the vehicle.

  Further, as shown in FIG. 3, the cover center upper surface member 34 is embedded with a gap 48 having a height H2 (several mm) at the left and right ends under the flanges 33 b and 33 b of the pair of cover center side members 33 and 33. It is connected in a state. The gap 48 extends in the front-rear direction of the vehicle on both the left and right sides of the vehicle. The gaps 47 and 48 also form the ventilation openings of the present invention. When the cylinder storage space reaches a predetermined pressure exceeding the atmospheric pressure (here, set to be less than the maximum pressure of the assumed cylinder storage space), the cover center upper surface member 34 has an end 34a on the roadway side. That is, the end 34b on the sidewalk side, that is, the end on the entrance / exit side, jumps up with the end opposite to the entrances 12 and 14 as an axis, and is attached from the closed state to the open state. Specifically, the connection strength between the end 34a on the roadway side of the cover center upper surface member 34 and the flange portion 33b of the cover center side member 33 is such that the end 34b on the sidewalk side of the cover center upper surface member 34 and the cover center. The side member 33 is attached so as to be stronger than the connection strength with the flange portion 33b. In addition, instead of making the end 34b on the sidewalk side jump up around the end 34a on the roadway side, a place where the cover center upper surface member 34 is easily deformed is provided and the cylinder storage space reaches a predetermined pressure. In addition, the end 34b on the sidewalk may be opened by deformation at this point. Further, a chain 37 is bridged between the back surface of the end 34a on the roadway side of the cover center upper surface member 34 and the cover center side surface member 33, and the cover center upper surface member 34 is in an open state. Sometimes it serves to prevent the fuel cell bus 10 from being removed from the roof cover 30 or the vehicle body.

  As shown in FIG. 4, the ventilation port 40 is composed of a slit group formed by spanning a plurality of louvers 44 over an opening 42 provided in the cover center upper surface member 34 at intervals. Specifically, of the four openings 42, 42, 42, 42 provided in the vehicle width direction of the cover center upper surface member 34, the right two openings 42, 42 can be bridged in the vehicle width direction. A plurality of long louvers 44 are arranged at predetermined intervals to form a slit group, and a plurality of similar louvers 44 are arranged at predetermined intervals in the left two openings 42 and 42. The slit group is formed by providing. Here, the louver 44 includes an inclined portion 44a that is inclined with respect to a horizontal plane and horizontal portions 44b and 44b that are connected to the upper and lower ends of the inclined portion 44a, and has a substantially Z-shaped cross section. . The horizontal portions 44b and 44b of the two adjacent louvers 44 and 44 are configured to have a predetermined interval.

  In the present embodiment, the inclination angle θ of the inclined portion 44a is determined within a range of 10 to 40 ° with respect to the horizontal plane. Here, the opening area of one ventilation port 40 is the sum Σs1 of the gap area s1 between adjacent louvers 44 as shown in FIG. Further, in the present embodiment, the gaps 47 and 48 in addition to the ventilation opening 40 also constitute the ventilation opening of the present invention, so that the total opening area S of the ventilation openings is the sum Σs1 of the clearance areas s1 of the ventilation openings 40. A value obtained by adding the opening area s2 of the gap 47 and the opening area s3 of the gap 48 to the summed value Σ (Σs1). The total opening area S is determined based on the volume C of the cylinder storage space. Specifically, the cylinder storage is performed so that the pressure of the cylinder storage space can be easily removed through the ventilation ports 40 and the gaps 47 and 48. The total opening area S is set to increase as the volume C of the space increases.

  Next, the function of the louver 44 in the fuel cell bus 10 of this embodiment will be described. The inclined portion 44a of the louver 44 prevents sunlight from directly hitting the hydrogen cylinder, and the horizontal portion 44b of the louver 44 prevents stepping stones or the like from directly hitting the hydrogen cylinder 18. For example, if the inclination angle θ of the inclined portion 44a is set so that daytime sunlight rays except for dawn and dusk cannot pass through the ventilation opening 40, the hydrogen cylinder 18 is effectively prevented from being deteriorated by the influence of the sunlight rays. Can be suppressed.

  Next, a case where hydrogen leaks from the hydrogen cylinder 18 for some reason in the fuel cell bus 10 of the present embodiment will be described. Since the hydrogen leaked from the hydrogen cylinder 18 has a specific gravity smaller than that of air, the hydrogen leaks up in the cylinder storage space and reaches the ventilation port 40 formed by a slit group formed on the upper surface of the roof cover 30. At this time, since the ventilation port 40 is formed at a position corresponding to the upper side of the hydrogen cylinder 18, the leaked hydrogen is ventilated at a shorter distance than when the ventilation port is formed at a position outside the hydrogen cylinder. Mouth 40 can be reached. Moreover, since the ventilation port 40 is provided in several places, the leaked hydrogen reaches the ventilation port 40 nearest to the distance. Then, after reaching the vent 40, the hydrogen gas passes upward through the vent 40 and flows out to the outside. Moreover, since the total opening area of the ventilation port 40 is sufficiently large, the pressure in the cylinder storage space does not become too high. Further, even if the pressure in the cylinder storage space reaches a predetermined pressure exceeding the atmospheric pressure, as shown by a one-dot chain line in FIG. 3, the cover center upper surface member 34 has an end 34a on the side of the sidewalk with the end 34a on the roadway side as an axis. Since the part 34b jumps up, the opening area increases at a stretch, and the pressure in the cylinder storage space is released at a stretch. Also from this point, the pressure in the cylinder storage space does not become too high. The cover center upper surface member 34 that has been bounced up in this manner is configured to stay on the roof 10 a by the chain 37.

  According to the fuel cell bus 10 of the present embodiment described in detail above, even if hydrogen gas leaks from the hydrogen cylinder 18 for some reason, the hydrogen gas rises up the cylinder storage space and is the most among the plurality of ventilation ports 40. It quickly reaches the nearby ventilation port 40 and efficiently flows out from there. Therefore, the hydrogen gas accumulated in the cylinder storage space can be discharged early. In addition, since the total opening area of the ventilation port 40 is set to a sufficient size, the pressure in the cylinder storage space is easily released through the ventilation port 40.

  Further, the ventilation port 40 is a group of slits formed by spanning a plurality of louvers 44 at intervals, and the louver 44 plays a role of protecting the hydrogen cylinder 18 from flying stones, solar rays, and the like. The durability of the hydrogen cylinder is improved compared to the case where is simply opened.

  Further, the cover center upper surface member 34, which is a constituent member of the roof cover 30, is changed from a closed state to an open state when the cylinder storage space reaches a predetermined pressure exceeding the atmospheric pressure. The space pressure drops rapidly. At this time, the cover center upper surface member 34 does not fall down to the entrance / exit side because the side end 34b jumps up around the end 34a on the roadway side. Moreover, since the open cover center upper surface member 34 is attached to stay on the roof 10a via the chain 37, it does not fall off the fuel cell bus 10 and fall.

  It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.

  For example, in the above-described embodiment, the slit group formed by spanning a plurality of louvers 44 at intervals in the opening is the ventilation port 40, but an opening (rectangular hole, circular hole, etc.) without the louver 44 is formed. It is good also as a ventilation port, and it is good also as what covered the lattice members, such as a mesh, in opening.

  In the above-described embodiment, the cover center upper surface member 34 is connected to the back surface of the flange portion 33b of the cover center side surface member 33. Instead, as shown in FIG. The cover center upper surface member 34 may be supported on the roof 10a via an elastic member 46 such as a spring so that a gap, that is, an opening area between the member 33 and the flange portion 33b is variable. In other words, it is elastically supported so that the gap between the cover center upper surface member 34 and the flange portion 33b of the cover center side member 33 is zero or small at normal times, and when the pressure in the cylinder storage space rises, the pressure acts and the elastic member 46 The gap between the cover center upper surface member 34 and the flange 33b of the cover center side surface member 33 may be widened by lifting the cover center upper surface member 34 against the elastic force. In this way, even if the pressure in the cylinder storage space increases, the pressure rapidly decreases because the opening area increases.

  Further, in the above-described embodiment, the louver 44 is configured such that the direction from the lower end to the upper end of the inclined portion 44a is obliquely rearward with respect to the horizontal plane, but the direction from the lower end to the upper end of the inclined portion 44a is relative to the horizontal plane. You may make it become diagonally forward.

  Furthermore, in the above-described embodiment, the volume C of the cylinder storage space is used as a parameter for determining the total opening area S of the ventilation port. However, the number of the hydrogen cylinders 18, the capacity of the hydrogen cylinders 18, the hydrogen cylinder 18 At least one of the internal pressure and the temperature of the cylinder storage space may be applied.

  In the above-described embodiment, the cover center upper surface member 34 and the cover center side surface member 33 attached with a gap between the left and right ends thereof constitute the cover center portion 32 of the roof cover 30. And the cover center side surface member 33 may be connected without leaving a gap, or both members 33 and 34 may be integrally formed.

  Further, in the above-described embodiment, the case where the vehicle is stipulated by law to pass on the left side of the road is described as an example, so the left side of the vehicle is described as the sidewalk side, and the right side of the vehicle is described as the roadside side. The present invention can also be applied to cases where it is legally required to pass on the right side, the left and right configurations of the vehicle in the above-described embodiment are reversed, the right side of the vehicle is on the sidewalk side, and the left side of the vehicle is on the roadway side. .

  In the above-described embodiment, the hydrogen cylinder 18 is described as an example of the gas fuel tank. However, any tank may be used as long as it is filled with gas fuel having a specific gravity smaller than that of air. For example, a CNG cylinder may be used in a vehicle equipped with a CNG engine.

  INDUSTRIAL APPLICABILITY The present invention can be used in a vehicle manufacturing industry equipped with a gas fuel tank, a service industry using the vehicle, and the like.

It is a left view of the fuel cell bus 10 of this embodiment. 3 is a perspective view of the vicinity of the center of the roof cover 30 of the fuel cell bus 10. FIG. FIG. 2 is a rear view (fracture sectional view) of the fuel cell bus 10. 4 is a perspective view of a cover center upper surface member 34. FIG. It is explanatory drawing of the opening area of the ventilation port. It is a rear view (fracture sectional view) of a fuel cell bus of other embodiments.

Explanation of symbols

10 fuel cell bus, 10a roof, 12 front entrance / exit, 14 center entrance / exit, 16 passenger cabin, 18 hydrogen cylinder, 20 fuel cell stack, 21 radiator, 22 auxiliary equipment, 24 rail, 26 metal band, 28 air conditioner unit, 30 roof cover, 31 cover front part, 32 cover center part, 33 cover center side member, 33a standing wall part, 33b collar part, 34 cover center top face member, 34a end part on the roadway side, 34b end part on the sidewalk side, 35 pedestal , 36 bolt, 37 chain, 39 cover rear part, 40 ventilation port, 42 opening, 44 louver, 44a inclined part, 44b horizontal part, 46 elastic member.

Claims (11)

A vehicle equipped with a gas fuel tank storing fuel gas having a specific gravity smaller than that of air,
A roof cover provided so as to cover the roof and forming a tank storage space capable of storing one or more of the gas fuel tanks;
A ventilation opening provided at a position on the upper surface of the roof cover and above the gas fuel tank;
With
The ventilation port is composed of a slit group formed by spanning a plurality of louvers at intervals in an opening provided in the roof cover,
The louver includes an inclined portion that is inclined obliquely rearward with respect to a horizontal plane in a direction from the lower end to the upper end, an upper horizontal portion that is connected to the upper end of the inclined portion and extends substantially horizontally, and the inclined portion A lower horizontal part connected to the lower end of the part and formed to extend substantially horizontally and covered with an adjacent louver ,
Vehicle with gas fuel tank. The ventilation openings are provided at a plurality of positions on the upper surface of the roof cover and at positions above the gas fuel tank.
The vehicle equipped with a gas fuel tank according to claim 1. The inclined portion is inclined at an angle of 10 to 40 ° with respect to a horizontal plane.
A vehicle equipped with a gas fuel tank according to claim 1 or 2. The total opening area of the ventilation port is determined based on at least the volume of the tank storage space,
A vehicle equipped with a gas fuel tank according to any one of claims 1 to 3. A vehicle equipped with a gas fuel tank according to any one of claims 1 to 4,
A lid member that is attached to the roof cover so as to be openable and closable and that is in an open state from a closed state when the tank storage space reaches a predetermined pressure exceeding the atmospheric pressure;
A vehicle equipped with a gas fuel tank. The lid member is attached with weaker strength on the sidewalk side compared to the roadway side,
The vehicle equipped with a gas fuel tank according to claim 5. The lid member is attached so that the sidewalk side is opened when the closed state is opened.
A vehicle equipped with a gas fuel tank according to claim 5 or 6. When the lid member is in an open state from a closed state, the lid member is attached so that the end portion on the sidewalk side rises with the end portion on the roadway side as an axis.
A vehicle equipped with a gas fuel tank according to any one of claims 5 to 7. The lid member is attached to the vehicle or the roof cover via a regulating member that prevents the lid member from being detached from the vehicle when the closed state is opened.
A vehicle equipped with a gas fuel tank according to any one of claims 5 to 8. The regulating member functions so that the lid member that has been opened from a closed state stays on the vehicle roof.
The vehicle equipped with a gas fuel tank according to claim 9. The lid member is elastically supported so as to change from a closed state to an open state according to an internal pressure of the tank storage space, or an opening area after the cover member is opened according to an internal pressure of the tank storage space is changed. Is elastically supported,
A vehicle equipped with a gas fuel tank according to any one of claims 5 to 10.

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