Fuel cell vehicle

Abstract

An aftercooler 800 is arranged between a hydrogen tank 21 and an air compressor 30 as a high-voltage electrical component. Even if the hydrogen tank 21 and the air compressor 30 are brought closer together by an external force, the aftercooler 800 protects the air compressor 30 from a collision with the hydrogen tank 21.

Description

TECHNICAL FIELDThe present invention relates to a fuel cell vehicle according to the preamble of Patent Application 1 and is directed to protection of high voltage electrical components mounted in a fuel cell vehicle.PRIOR ARTIn JP 2015-231 319 A, a fuel cell vehicle is disclosed which has a fuel cell stack mounted in a space that is in front of a passenger compartment and separated from the passenger compartment by a dash panel. In this fuel cell vehicle, a hydrogen tank is mounted in a center tunnel. Regarding the prior art, reference is also made to DE 11 2015 002 691 T5, DE 11 2015 001 911 T5, DE 10 2014 008 480 A1, DE 11 2013 000 874 T5 and JP 2014-113 910 A.SUMMARYTechnical ProblemDue to a (tail-up) collision or the like, the hydrogen tank may interfere with other components mounted in a fuel cell vehicle. The other components include high voltage electrical components. The term "high-voltage electrical components" refers to electrical components that operate at high voltage. The high voltage electrical components are therefore preferably better protected from collision with the hydrogen tank than other components than the high voltage electrical components.As a countermeasure for protecting the high voltage electric components, it is conceivable to arrange the hydrogen tank and the high voltage electric components far from each other in their mounting position. However, this countermeasure makes it difficult to make the vehicle compact.Another countermeasure would be to provide an exclusive protection element for protecting the high voltage electrical components. However, this countermeasure would result in an increase in cost.Based on the above-described circumstances, the present invention has an object of realizing the protection of high-voltage electric components from colliding with the hydrogen tank in a compact, low-cost manner.Solution to the ProblemThe above-mentioned object is achieved with the features of claim 1. Advantageous embodiments for this are mentioned in the further patent claims.According to an aspect of the present invention, there is provided a fuel cell vehicle including: a front compartment formed in front of a passenger compartment; a center tunnel constituting an under-floor space formed by swelling a bottom of the passenger compartment along the front-rear direction of the vehicle substantially in the center of a width direction of the vehicle; a hydrogen tank disposed in the center tunnel of the vehicle such that a center axis thereof is substantially parallel to the front-rear direction of the vehicle; a high-voltage electric component disposed in front of or behind the hydrogen tank and operating at high voltage; an aftercooler disposed between the hydrogen tank and the high-voltage electric component to cool compressed air; and a fuel cell stack supplied with the cooled compressed air. The aftercooler, the hydrogen tank, and the high voltage electric component are arranged such that the aftercooler is disposed between the hydrogen tank and the high voltage electric component in the front-rear direction of the vehicle, and the aftercooler, the hydrogen tank, and the high voltage electric component are disposed along the central axis of the hydrogen tank. According to this aspect, the protection of the high-voltage electric component from colliding with the hydrogen tank can be realized in a compact, inexpensive manner. Since the aftercooler serves as a protection member for protecting the high-voltage electric component from colliding with the hydrogen tank, it is no longer necessary to keep the hydrogen tank and the high-voltage electric component far from each other in their mounting position. Thus, it becomes possible to make the fuel cell vehicle compact. In addition, since the aftercooler is not an exclusive element for protecting the high voltage electric component, an increase in cost is avoidable.In the above aspect, the high voltage electric component may be accommodated in the front space, and the hydrogen tank may be disposed behind the high voltage electric component. According to this aspect, when the high-voltage electric component is accommodated in the front space, the high-voltage electric component can be protected.In the above aspect, the high voltage electric component may be an air compressor for supplying compressed air into the aftercooler, and the fuel cell stack may be accommodated in the front space, wherein the fuel cell vehicle may further include an oxidizing gas supply path connected to a rear side of the fuel cell stack and allowing the cooled compressed air to flow therethrough. According to this aspect, the length of the oxidizing gas supply path in the flow direction can be shortened. Since the aftercooler is disposed behind the air compressor, it is reasonable that the conduit that allows compressed air that has flowed out of the aftercooler to pass therethrough is disposed to extend rearward of the aftercooler. In addition, since the fuel cell stack is accommodated in the front space, the pipe extending rearward from the aftercooler is directed rearward from the rear side of the fuel cell stack. Therefore, the oxidizing gas supply path can be made shorter by connecting the oxidizing gas supply path to the back side of the fuel cell stack.In the above aspect, the air compressor may be disposed below the fuel cell stack. According to this aspect, since the hydrogen tank can be mounted at a rather deep position, the resultant arrangement becomes suitable for mounting it along the front-rear direction.In the above aspect, the high voltage electric component may be an air compressor for supplying compressed air to the aftercooler. According to this aspect, the air compressor can be protected.In the above aspect, the aftercooler may be mounted in such an inclined posture that its bottom surface intersects the front-rear direction. According to this aspect, even more effective protection of the high voltage electric component can be achieved. Since the aftercooler is mounted in an inclined position, a collision between the aftercooler and the hydrogen tank causes a force in a rotational direction on the aftercooler. By this rotation, an impact due to the collision of the aftercooler with the hydrogen tank is alleviated, whereby the above-described effects can be obtained.The present invention may also be implemented in other ways than in the aspects described above. For example, the disclosure herein may also be used for a manufacturing method for a fuel cell vehicle.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a diagram showing a basic configuration of a fuel cell system; FIG. 2 is a side view showing a basic configuration of a fuel cell vehicle; FIG. 3 is a bottom view showing a basic configuration of the fuel cell vehicle; FIG. 4 is a sectional view taken along line 4-4; FIG. 5 is a bottom view of an aftercooler; FIG. 6 is an enlarged view of a vicinity of the aftercooler; FIG. 7 is a view illustrating an aspect in which a collision has occurred between the hydrogen tank and the aftercooler; and FIG. 8 is a view illustrating an aspect in which a torn-off aftercooler has moved.DESCRIPTION OF EMBODIMENTSFIG. 1 shows a basic configuration of a fuel cell system 200. The fuel cell system 200 includes a fuel gas system 2, an oxidizing gas system 3, a cooling water system 7, a controller 10, a fuel cell stack 100, and an electric circuit 210.The fuel cell stack 100 has a plurality of cells 11 stacked together along a stacking direction SD. The fuel cell stack 100 has a pair of end plates 110, 120 at both end portions in the stacking direction SD. Each cell 11 is a solid polymer fuel cell. The cells 11 generate electric power by electrochemical reaction of fuel gas and oxidizing gas. In this embodiment, the fuel gas is hydrogen gas and the oxidizing gas is air.In the fuel cell stack 100, header pipes (not illustrated) are formed as flow paths for fuel gas, oxidizing gas, and cooling water along the stacking direction SD of the cells 11.A pair of current collecting plates 103F, 103R in the fuel cell stack 100 are electrically connected to the electric circuit 210. An insulating plate 102F is disposed between the current collecting plate 103F and the end plate 110. Likewise, an insulating plate 102R is disposed between the current collecting plate 103R and the end plate 120. The electric circuit 210 is composed of an inverter, a converter, and the like, which are well known. The electric circuit 210 electrically connected to a motor M converts electric power of the fuel cell stack 100 and supplies it to the motor M.The fuel gas system 2 includes auxiliary machines 20, a hydrogen tank 21, a hydrogen tank 22, a hydrogen tank 23, and a fuel gas discharge path 29.The hydrogen tanks 21, 22, 23 storing the hydrogen under high pressure supply hydrogen gas as fuel gas to the auxiliary machines 20. The auxiliary machines 20 are constituted by an injector, a hydrogen pump, a gas-liquid descriptors, and the like, which are well known. The auxiliary machines 20 supply the fuel gas to the fuel cell stack 100 or discharge the fuel gas via the fuel gas discharge path 29.The oxidizing gas system 3 includes an air compressor 30, an oxidizing gas supply path 31, an air cleaner 32, a three-way valve 33, an ejection flow path 34, an outlet flow path 35, a bypass 36, an intake flow path 37, a pressure control valve 38, an ejection flow path 39, an aftercooler 800, an inlet part 940, and an outlet part 950. Aftercooler 800 is also referred to as an intercooler.The air cleaner 32 collects foreign matter contained in the air flowing through the air cleaner. The air compressor 30 compresses the air sucked from the atmosphere via the air cleaner 32 and the suction flow path 37. The compressed air reaches a high temperature. The air compressed by the air compressor 30 flows into the after-cooler 800 via the discharge flow path 34 and the inlet part 940. The compressed air that has flowed into the aftercooler 800 is cooled by the aftercooler 800.The compressed air cooled by the aftercooler 800 flows into the three-way valve 33 via the outlet part 950 and the outlet flow path 35, and the compressed air that has flowed into the three-way valve 33 flows at least into the oxidizing gas supply path 31 and / or the bypass 36 depending on the opening degree of the three-way valve 33.The compressed air that has flowed into the oxidizing gas supply path 31 flows into the fuel cell stack 100. The compressed air that has flowed into the fuel cell stack 100 flows through the fuel cell stack 100 and flows into the pressure regulating valve 38 The air that is pressure-regulated by the pressure regulating valve 38 is discharged to the atmosphere via the discharge flow path 39. The compressed air that has flowed into the bypass 36 is discharged to the atmosphere via the discharge flow path 39.The cooling water system 7 includes a water pump 710, a cooling water supply flow path 720, an aftercooler supply flow path 730, an aftercooler discharge path 740, a cooling water discharge flow path 750, a bypass 760, a three-way valve 770, and a radiator 780.The water pump 710 circulates the cooling water. A part of the cooling water that has flowed out of the water pump 710 flows into the fuel cell stack 100 via the cooling water supply flow path 720. The cooling water that has flowed into the fuel cell stack 100 cools the fuel cell stack 100, and is then discharged from the fuel cell stack 100. The cooling water discharged from the fuel cell stack 100 flows into the cooling water discharge flow path 750. The cooling water that has flowed into the cooling water discharge flow path 750 flows at least into the bypass 760 and / or the radiator 780 depending on the opening degree of the three-way valve 770.The cooling water that has flowed into the radiator 780 is cooled by the radiator 780 and then discharged from the radiator 780. The cooling water discharged from the radiator 780 flows into the water pump 710. The cooling water that has flowed into the bypass 760 flows into the water pump 710 with almost no cooling.Of the cooling water that has flowed from the water pump 710, the cooling water that does not flow into the fuel cell stack 100 flows into the aftercooler 800 via the aftercooler supply flow path 730. The cooling water that has flowed into the aftercooler 800 cools the compressed air that flows through the aftercooler 800, and then flows into the cooling water discharge path 750 via the aftercooler discharge flow path 740.The various operations described above are controlled by the controller 10. The controller 10 is comprised of one or more ECUs.The air compressor 30, the water pump 710, a hydrogen pump included in the auxiliary machines 20, and the motor M are high voltage electric components. The term high voltage electrical components refers to components or parts that operate at high voltage. The term high voltage refers to a voltage equal to or higher than a certain voltage value defined by specifications applied to the respective countries in which the fuel cell vehicle 500 described later travels. The air compressor 30 of this embodiment operates at a voltage of about 650 V. The determined voltage value is a value lower than 650 V.The determined voltage value is higher than 12 V. Therefore, components operating at 12 V are components other than the high voltage electric components. For example, a pressure sensor 827 and a temperature sensor 829 described later operate at 12 V and are therefore components other than the high voltage electric components.FIG. 2 is a side view of a basic configuration of a fuel cell vehicle 500. FIG. 3 is a bottom view showing the basic configuration of the fuel cell vehicle 500. In FIGS. 2 and 3, a part of the body or the like is omitted as appropriate from the illustration.The fuel cell vehicle 500 has the fuel cell system 200 described above and a motor M mounted thereon. rear wheels RW are driven by a torque of the motor M. In FIGS. 2 and 3, the constituent elements of the fuel cell system 200 shown in FIG. 1 are partially not illustrated.In this embodiment, the forward direction FD and the rearward direction RD are generally referred to as the front-rear direction. In the fuel cell vehicle 500, a front room 510, a center tunnel 520, and a passenger compartment 530 are formed.The front space 510 is formed as a space that is disposed on the forward direction FD side of the fuel cell vehicle 500 and includes a region disposed between a pair of front wheels FW. As shown in FIGS. 2 and 3, the front space 510 accommodates the air compressor 30, the oxidizing gas supply path 31, the air cleaner 32, the discharge flow path 34, the aftercooler 800, the inlet part 940, and the outlet part 950.As shown in FIGS. 2 and 3, the air compressor 30 and the aftercooler 800 are disposed immediately below the fuel cell stack 100.The center tunnel 520 is disposed on the rearward direction RD side of the front compartment 510 and below the floor of the passenger compartment 530. A boundary between the front space 510 and the center tunnel 520 cannot be clearly defined, and the front space 510 and the center tunnel 520 are configured to be spatially contiguous.The passenger compartment 530 is disposed on the rear direction RD side of the front compartment 510 at the upper side of the center tunnel 520. Front seats FS and rear seats RS are accommodated in the passenger compartment 530. The front space 510 and the passenger compartment 530 are separated from each other by a dash panel DB. The center tunnel 520 and the passenger compartment 530 are separated from each other by a floor panel 610.As shown in FIG. 2, the fuel cell stack 100 is disposed to be inclined downward in the front-rear direction toward the rearward direction RD. In other words, the fuel cell stack 100 is disposed at such an inclination in the front-rear direction as to be progressively lower toward the rearward direction RD.The oxidizing gas supply path 31 is connected to the end plate 120. More specifically, the oxidizing gas supply path 31 is connected to an opening formed in the end plate 120. The term opening here denotes an opening of the aforementioned collecting pipe.In a position where the fuel cell stack 100 is mounted on the fuel cell vehicle 500, the end plate 120 is located on the most rearward direction RD side of constituent elements of the fuel cell stack 100. Thus, the oxidizing gas supply path 31 is connected to the back side of the fuel cell stack 100. That is, the oxidizing gas supply path 31 is a flow path line that connects the back side of the fuel cell stack 100 and the outlet part 950 serving as an outlet flow path of the air compressor 30.As described above, the air compressor 30 is disposed immediately below the fuel cell stack 100. Therefore, generally speaking, compressed air flows from the air compressor 30 to the fuel cell stack 100 after flowing substantially in the rearward direction RD, flows vertically upward, and then flows substantially in the forward direction FD.The aftercooler 800 forms a flow path that is directed substantially in the rearward direction RD as described above. The oxidizing gas supply path 31 forms a flow path directed vertically upward as described above and a flow path directed substantially in the forward direction FD. The oxidizing gas flow path 31 is formed shorter in flow path length to supply the compressed air, which has flowed out of the aftercooler 800 located immediately below the fuel cell stack 100, through the back side of the fuel cell stack 100.The hydrogen tanks 21, 22, and 23 have a substantially cylindrical outer shape. The hydrogen tank 22 and the hydrogen tank 23 are arranged such that their central axes are substantially parallel to the width direction LH. The hydrogen tank 22 and the hydrogen tank 23 are disposed on the rearward direction RD side of the rear seats RS. In addition, the hydrogen tank 22 and the hydrogen tank 23 are not illustrated in FIG. 3.As shown in FIGS. 2 and 3, the hydrogen tank 21 is accommodated such that its central axis O is substantially parallel to the front-rear direction. The center tunnel 520 accommodates the hydrogen tank 21. The center tunnel 520 is formed at substantially the center of the width direction LH along the front-rear direction. A ceiling part of the center tunnel 520 and a bottom part of the passenger compartment 530 are formed by the floor panel 610.FIG. 4 is a sectional view showing a cross section taken along a line 4- 4 in FIG. 2. The center tunnel 520 has a shape similar to a center tunnel that receives a propeller shaft in known internal combustion engine vehicles. The cardan shaft is also referred to as a drive shaft. The center tunnel 520 is formed of the vertically upper arc panel 610, a side wall portion 620, and a lower cover 630. A portion of the floor of the passenger compartment 530 corresponding to the center tunnel 520 is "swollen" vertically upward compared to other portions.The hydrogen tank 21 is fixed to the side wall portion 620 by a first fixing member 310 and a second fixing member 320. The first fastening element 310 and the second fastening element 320 each comprise a band section and a fastening section. The band portion surrounds the hydrogen tank 21 in the circumferential direction thereof. The attachment portion enables the band portion to be attached to the side wall portion 620.FIG. 5 shows a bottom view of aftercooler 800. The aftercooler 800 includes an inlet flange 810, an inlet connection part 815, an outlet flange 820, an outlet connection part 825, a pressure sensor 827, a temperature sensor 829, a cooling water inlet flow path 830, a cooling water outlet flow path 840, and a main body 880.The inlet flange 810 is connected to the inlet part 940. The outlet flange 820 is connected to the outlet member 950. Compressed air flows through the inlet flange 810 and flows into the main body 880 via the inlet connection portion 815.Besides, the cooling water inlet flow path 830 is connected to the aftercooler supply flow path 730. The cooling water discharge flow path 840 is connected to the aftercooler discharge flow path 740. Cooling water discharged from the water pump 710 flows into the main body 880 via the aftercooler supply flow path 730. The cooling water flown into the main body 880 cools the compressed air that has flown into the main body 880. The cooling water that has cooled the compressed air flows into the aftercooler discharge flow path 740 via the cooling water outlet flow path 840.The compressed air cooled in the main body 880 flows into the outlet part 950 via the outlet connection part 825 and the outlet flange 820.The pressure sensor 827 is attached to the outlet connection part 825. The pressure sensor 827 measures the pressure of the compressed air after cooling. The temperature sensor 829 is attached to the outlet connection part 825. The temperature sensor 829 measures the temperature of the compressed air after cooling.A bottom surface of the main body 880 is referred to as a bottom surface 881. FIG. 5 shows the bottom surface 881 as the main body 880. Note that the cooling water inlet flow path 830 and the cooling water outlet flow path 840 are connected to the front side of the main body 880.FIG. 6 is an enlarged view of the vicinity of the aftercooler 800. The aftercooler 800 is mounted in an inclined position. More specifically, the aftercooler 800 is mounted in such a position that the outlet portion 950 is disposed above the inlet portion 940. For this reason, the bottom surface 881 intersects the front-rear direction. As shown in FIG. 6, a cut angle is smaller than the right angle. The bottom surface 881, as shown in FIGS. 3 and 6, is further disposed so as to intersect the central axis O. An angle formed by the bottom surface 881 and the central axis O is an angle θ. The angle θ is equal to an angle formed by the bottom surface 881 and the front-rear direction.FIG. 7 shows an aspect in which a collision has occurred between the hydrogen tank 21 and the after-cooler 800. This collision is caused by a rear-end collision of the fuel cell vehicle 500 or the like. The collision results in at least one of the hydrogen tank 21 and the air compressor 30 being moved so that the hydrogen tank 21 and the air compressor 30 come closer to each other.The collision may cause breakage of the after-cooler 800. When a tear-off occurs, the tear-off often occurs first at the outlet connection portion 825. This is because the outlet connection part 825 is disposed in the vicinity of the hydrogen tank 21 to absorb the force immediately after the collision in many cases, and the outlet connection part 825 includes a location having a smaller cross-sectional area so that the load concentrates on this location. FIG. 7 shows a broken-away surface of the outlet connection part 825 as the breaking surface F 1.FIG. 8 shows an aspect in which a detached aftercooler 800 has moved. When the hydrogen tank 21 and the air compressor 30 approach each other after the occurrence of the separation at the outlet connection part 825, the aftercooler 800 is rotated. This rotation takes place about the width direction LH. The rotation is caused by the inclination of the bottom surface 881.As the rotation angle becomes larger, the inlet connection part 815 tears. This is because the inlet connection part 815 includes a location having a smaller cross-sectional area, similarly to the outlet connection part 825. FIG. 8 shows the cracked surface of the inlet connection part 815 as the cracking surface F 2.The force that causes the hydrogen tank 21 and the air compressor 30 to approach each other is attenuated by the separation of the outlet connection part 825 and the inlet connection part 815, and the rotation of the aftercooler 800. As a result, the air compressor 30 is protected.The present invention is not limited to the above-described embodiments, examples, and modifications in the specification, and can be variously embodied without departing from the spirit of the invention. For example, the technical features of the embodiments, examples, and modifications corresponding to the technical features in the aspects described in the summary may be replaced or combined with each other as necessary to solve a part or all of the problems described above, or to achieve a part or all of the advantageous effects described above. Moreover, the technical features may be omitted as needed as long as they are not described herein as essential, which will be exemplified below.The high voltage electric components to be protected by the aftercooler 800 may be other than the air compressor 30. for example, the high voltage electric component may be the water pump 710, the hydrogen pump, or the engine M. Assuming that the fuel cell vehicle 500 is configured with an air conditioner, the high voltage electric component to be protected by the after cooler 800 may be a compressor that compresses the refrigerant for air conditioning. Moreover, whether or not the voltage used for the operation is a high voltage may be arbitrarily determined depending on regulations.At least the fuel cell stack and / or the high voltage electric components may be protected by being disposed behind the rear seat RS. For example, in order to protect the engine M, the engine M may be disposed in the front room, or the after-cooler 800 may be disposed behind the rear seat RS.The air compressor 30 may be disposed above the fuel cell stack 100.The aftercooler 800 may be mounted in a non-inclined position. That is, the after cooler 800 may be mounted such that the bottom surface 881 becomes horizontal.The space in which the hydrogen tank 21 is mounted may not be formed as a center tunnel 520. For example, it is also possible that the bottom of the passenger compartment 530 is formed flat, while the hydrogen tank 21 is disposed so as to hang below the bottom.The aftercooler 800 may not require at least the pressure sensor 827 and / or the temperature sensor 829.

Claims

A fuel cell vehicle (500) comprising: a front space (510) formed in front of a passenger compartment (530); a center tunnel (520) constituting an under-floor space formed by swelling a bottom of the passenger compartment (530) along the front-rear direction of the vehicle (500) substantially in the center of a width direction of the vehicle (500); a hydrogen tank (21) disposed in the center tunnel (520) of the vehicle (500) such that the center axis (O) thereof is parallel to the front-rear direction of the vehicle (500); and a high voltage electric component (30) disposed in front of or behind the hydrogen tank (21) and operating at high voltage; an aftercooler (800) disposed between the hydrogen tank (21) and the high voltage electric component (30) to cool compressed air; and a fuel cell stack (100) supplied with the cooled compressed air, characterized in that the aftercooler (800), the hydrogen tank (21), and the high voltage electric component (30) are disposed such that the aftercooler (800) is disposed between the hydrogen tank (21) and the high voltage electric component (30) in the front-rear direction of the vehicle (500), and the aftercooler (800), the hydrogen tank (21), and the high voltage electric component (30) are disposed along the central axis (O) of the hydrogen tank (21).The fuel cell vehicle (500) according to claim 1, wherein: the high voltage electric component (30) is accommodated in the front space (510), and the hydrogen tank (21) is disposed behind the high voltage electric component (30).The fuel cell vehicle (500) according to claim 2, wherein the high voltage electric component (30) is an air compressor for supplying compressed air into the aftercooler (800), and the fuel cell stack (100) is accommodated in the front space (510), the fuel cell vehicle (500) further comprising an oxidizing gas supply path (31) connected to a rear side (120) of the fuel cell stack (100) and allowing the cooled compressed air to flow therethrough.The fuel cell vehicle (500) of claim 3, wherein the air compressor (30) is disposed below the fuel cell stack (100).The fuel cell vehicle (500) according to claim 1 or 2, wherein the high voltage electric component (30) is an air compressor for supplying compressed air into the aftercooler (800).The fuel cell vehicle (500) according to any one of claims 1 to 5, wherein the aftercooler (800) is mounted in an inclined posture such that its bottom surface (881) intersects the front-rear direction.

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