DE112005002174B4 - Architecture of a fuel cell vehicle - Google Patents

Abstract

A vehicle chassis (8), comprising:a frame (10) defining at least one cavity (20, 176), the at least one cavity (20, 176) comprising a first cavity (20) and a second cavity (176); at least one tank (90, 90', 94, 98) adapted to store compressed hydrogen gas and which is at least partially disposed in the first cavity (20) and is longitudinally aligned with respect to the frame (10);a floor panel (140) disposed over the first cavity (20) and the second cavity (176) and defining a hollow vault (170) which is at least partially cylindrical in shape; wherein the one tank (90, 90') or one of the multiple tanks (90, 90', 94, 98) is partially arranged in the hollow vault (170);wherein the base plate (140) is at least partially a rigid base surface (144). passenger compartment (142);wherein the floor panel (140) defines a bulge (152) in the rigid floor surface (144) opposite the hollow bulge (170); andwherein the rigid floor surface (144) at a front end (160) of the passenger compartment (142) is flat.

Description

TECHNICAL FIELD

This invention relates to vehicle chassis and vehicles having lengthwise compressed gas storage tanks beneath a passenger compartment.

BACKGROUND OF THE INVENTION

Prior art vehicles typically include an internal combustion engine housed in an engine compartment at the front or rear of the vehicle body. The machine is powered by a liquid, such as gasoline or diesel fuel, which is typically stored in a tank in the rear of the vehicle. The machine drives the vehicle by applying torque to road wheels through a mechanical transmission.

Alternative vehicle fuels, such as compressed hydrogen and natural gas, have a lower specific thermal energy per unit volume than liquid fuels, such as gasoline and diesel fuel, i.e. they have a relatively low energy density. Accordingly, an alternative fuel vehicle may have a significantly shorter refueling range than a conventional fuel vehicle with the same fuel storage capacity. It is therefore desirable for alternative fuel vehicles to accommodate larger fuel storage tanks than those found in conventional fuel vehicles.

The US 6,190,793 B1 discloses a fuel cell stack constructed of fuel cell plates and using hydrogen, which may be stored in a fuel tank, as fuel.

In the EP 1 145 891 A2 a gas or trolley bus is disclosed with a chassis to which an underfloor installation module can be attached. Fuel tanks that are oriented in the longitudinal direction of the bus can be installed in the underfloor installation module.

The EP 0 067 576 A1 is considered the closest prior art and discloses a floor panel with a rectangular hollow curvature in the longitudinal direction of the vehicle in which a fuel tank is completely housed. The hollow arch extends to the front end of a passenger compartment of the vehicle.

In the US 5,673,939 A discloses a fuel tank assembly with cylindrical pressure tanks for storing compressed hydrogen gas. The fuel tank assembly is arranged under a floor panel of the vehicle on a vehicle chassis such that the floor panel is flat.

The US 2003/0 037 974 A1 discloses a fuel cell vehicle with cylindrical fuel tanks arranged in a cavity of a vehicle frame such that a floor panel of the vehicle can be flat.

In the DE 101 54 353 A1 discloses a vehicle chassis having a frame, a vehicle underbody, and a floorpan, in which a power source, such as a fuel tank, is enclosed in a space defined by the frame, the vehicle underbody, and the floorpan. A bulge is provided in the base plate, which extends lengthwise over the entire base plate. The DE 103 12 205 A1 discloses a fuel tank assembly including a plurality of interconnected cylindrical gaseous fuel tanks. When installing the cylindrical fuel tanks, the size of the trunk is reduced.

In the US 2004/ 0 173 391 A1 a cylindrical gas tank with a battery unit is disclosed, which is molded onto it in such a way that the required installation space is minimized. If greater battery capacity is required, additional battery cells can be added at the expense of trunk space or at the expense of gas tank volume.

It is also desirable to locate alternative fuel storage tanks in a protected location within the vehicle chassis. Accordingly, alternative fuel storage tanks are typically located between the rear wheels of the vehicle. However, the installation space between the rear wheels is limited, which in turn limits the size of the tanks and the vehicle range between refueling.

The object of the invention is to accommodate fuel tanks for gaseous fuels in a vehicle in such a way that the fuel tanks are protected as well as possible and their space requirements impact the passenger compartment as little as possible.

SUMMARY OF THE INVENTION

This task is solved by the subject matter of the independent claims.

According to a first aspect of the invention, there is provided a vehicle having improved gaseous fuel storage capability. The vehicle includes a frame that has a central cavity or compartment defined, and a tank arranged to store compressed hydrogen. The tank is at least partially arranged in the cavity and aligned lengthwise with respect to the frame. In an exemplary embodiment, a vehicle floor panel is connected to the frame and covers the cavity. The vehicle floor panel defines a partially cylindrical hollow bulge in which the tank is partially disposed, and a corresponding bulge on the side of the vehicle floor panel opposite the hollow bulge, ie, the surface of the vehicle floor. At a front end of the passenger compartment, the surface of the vehicle floor is flat.

According to a second aspect of the invention, a fuel cell vehicle is provided with design flexibility whereby a reduction in fuel tank size enables an increase in fuel cell stack size. The fuel cell stack is disposed adjacent the fuel tank and is oriented so that additional fuel cells can be added to the side of the stack facing the tanks. Accordingly, when a long tank is removed and replaced with a shorter tank, the fuel cell stack can be enlarged by adding fuel cells that take up the space previously occupied by the large tank. The design also accommodates vehicle manufacturers who can assemble multiple vehicles with a common chassis and frame design but different fuel cell and tank configurations.

The foregoing features and advantages and other features and advantages of the present invention will be readily apparent from the following detailed description of the best modes of carrying out the invention when read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

• 1 is a schematic plan view, with partial omissions, of a chassis for a vehicle according to the invention;
• 2 is a schematic top view of the frame of the chassis of 1 ;
• 3 is a schematic perspective view of the frame of 2 , with wheels and a front-wheel drive engine attached with respect thereto;
• 4 is a schematic cross-sectional view of the frame and hydrogen storage tanks of the chassis of 1 ;
• 5 is a schematic perspective view of the chassis of 1 , which has a tunnel formed in the vehicle floor panel to accommodate one of the hydrogen storage tanks 4 represents; and
• 6 is a schematic cross-sectional side view of the fuel cell stack and hydrogen storage of the chassis of 1 .

DESCRIPTION OF THE PREFERRED EMBODIMENTS

On 1 Referring to this, a chassis 8 for a vehicle 9 is shown schematically. The chassis includes a structural frame 10. Referring to 2 and 3 the frame includes a first rail 14 and a second rail 18 which cooperate to at least partially define a protected cavity 20 therebetween. A third rail 22 lies outside the first rail 14 and cooperates with the first rail 14 to at least partially define a first lateral cavity 24 outside the protected cavity 20. A fourth rail 26 lies external to the second rail 18 and cooperates with the second rail 18 to at least partially define a second lateral cavity 28 external to the protected cavity 20. Various chassis components are shown within the side cavities 24, 28. A cross member 32 rigidly connects the first and second rails 14, 18 to one another. A cross member 36 rigidly connects the first and third rails 14, 22 to one another. A cross member 40 rigidly connects the second and fourth rails 18, 26 to one another.

The frame 10 also includes a first node 44, a second node 48, a third node 52 and a fourth node 56. The nodes, which are preferably cast, connect various elements of the frame 10 substantially rigidly together. More specifically, the first node 44 connects a first front element 60 to the first rail 14 and the third rail 22. The second node 48 connects a second front element 64 to the second rail 18 and the fourth rail 26.

The third node 52 connects a first rear frame element 66 to the first and third rails 14, 22. The fourth node 56 connects a second rear frame element 70 to the second and fourth rails 18, 26.

A cross member 74 connects the first and second nodes 44, 48. A cross member 78 connects the third and fourth nodes 52, 56. A front bumper member 82 is connected to the two front members 60, 64. A rear bumper element 86 is connected to the two rear elements 66, 70 tied together. The rails 14, 18, 22, 26 and the frame members 60, 64, 66, 70 are preferably extruded or hydroformed aluminum tubes.

Especially on 1 Referring to the vehicle 9, it includes three substantially cylindrical tanks 90, 94, 98 configured to store compressed hydrogen. Tank 90 is longer and has a larger diameter than tanks 94 and 98. Tanks 94 and 98 are substantially the same size and are located on opposite sides of tank 90. The tanks 90, 94, 98 are at least partially arranged in the protected central cavity 20 of the frame 10.

On 4 Referring to, where like reference numerals represent like components 1 - 3 denote, a tank support assembly 102 includes at least one base element 106 that defines three depressions or hollow bulges 110, 114, 118. The surface defining each of the hollow bulges is partially cylindrical with a diameter slightly larger than the diameter of one of the tanks 90, 94, 98. The tank 94 is partially arranged in the hollow vault 110, the tank 90 is partially arranged in the hollow vault 114 and the tank 98 is partially arranged in the hollow vault 118. Accordingly, the hollow curvatures act to at least partially position and hold a respective tank.

The tank support assembly 102 further includes a band 122, shackles 130 connected to the base member 106, and rubber bushings 126, each of which is connected to the yoke or base member 106 by a respective shackle 130. It may be desirable to use T-bolts instead of shackles. The band 122 is preferably made of stainless steel. One side of the band 122 contacts a portion of the perimeter of each of the tanks 90, 94, 98. The other side of the band 122 contacts a portion of the perimeter of the rubber bushings 126 so that the band 122 is tensioned and the tanks 90, 94, 98 holds on to the base element 106. The rubber liners 126 are deformable to allow for variations in tank dimensions due to pressurization. Rubber insulation (not shown) is preferably used between the stainless steel band 122 and the tanks 90, 94, 98 to protect the tank material and to further accommodate variations in tank dimensions. The cavities 24, 28 form energy-absorbing crumple zones on the respective long sides of the cavity 20.

An underbody pan 134 seals the lower opening of the protected cavity 20. A vehicle floor panel 140 extends above and over the upper opening of the protected cavity 20 and forms a rigid floor surface 144 of the vehicle interior or passenger compartment 142. Within the scope of the claimed invention, the rigid floor surface 144 may include one or more coverings, such as a cushion or a Carpet (not shown). The vehicle underbody pan 134, the vehicle floor panel 140 and the rails 14, 18 define a hydrogen storage compartment that has at least partially the same content as the cavity 20. On 4 and 5 Referring to this, the floor surface 144 is substantially flat and provides mounting points 148 at which front and rear passenger seats (not shown) can be connected to the vehicle floor panel 140. The vehicle floor panel 140 is characterized by a tunnel 152 formed therein. The tunnel 152 is a partially cylindrical bulge in the substantially flat floor surface 144 to accommodate the size of the tank 90. The forwardmost extent 156 of the tunnel does not extend substantially in front of the front seats or the front seat mounting points 148, leaving a substantially flat area 160 of the vehicle floor 144 extending lengthwise between the front seats and the bulkhead 164 or the dashboard 168 extends. The substantially flat region 160 extends transversely from one side edge of the vehicle floor panel to the other side edge of the vehicle floor panel.

Up again 4 Referring to this, a partially cylindrical hollow bulge 170 in which the tank 90 is partially disposed faces the bulge in the vehicle floor surface.

Up again 1 and 2 Referring to the vehicle, the vehicle also includes a fuel cell stack 172. The fuel cell stack 172 is contained within a cavity 176 formed between nodes 44 and 48, as shown in FIG 2 is shown. The fuel cell stack lies under the essentially flat area 160 of the vehicle floor panel 140, which is in 1 shown partially cut away. The tanks 90, 94, 98 are operatively connected to the fuel cell stack 172 to selectively supply the stack 172 with hydrogen gas. On 6 Referring to, where like reference numerals represent like components 1 - 5 denote, the vehicle floor panel 140 and a lower protective cover 180 at least partially define a fuel cell stack compartment, which has at least partially the same content as the cavity 176. The fuel cell stack compartment is adjacent to the hydrogen tank compartment, and the frame 10 provides an unobstructed opening to connect the fuel cell stack and hydrogen tank compartments, for example under or through the cross element 32 through. The tanks are aligned lengthwise with respect to the vehicle and the fuel cell stack 172 is located in front of the tanks.

The fuel cell stack 172 is formed from individual fuel cells 184 that are electrically connected to one another. The size and therefore the performance of the fuel cell stack 172 can be changed by adding or removing fuel cells from the stack. The fuel cell stack 172 is oriented within the vehicle such that additional fuel cells can be added to the stack at the rear end 186 of the stack. The design of the vehicle is therefore such that shorter hydrogen storage tanks, i.e. tanks with a small longitudinal dimension, can replace the tanks 90, 94, 98. The shorter hydrogen storage tanks provide increased space in the front region 188 of the hydrogen tank compartment compared to the tanks 90, 94, 98. The fuel cell stack 178 may then be enlarged by adding fuel cells to the rear end 186 of the stack 172, with at least some of the added fuel cells occupying a space in the hydrogen tank compartment previously occupied by the tanks 90, 94, 98. In this way, the design and architecture of the vehicle creates design flexibility: by reducing the size of the hydrogen storage tanks, space is made available in the direction of fuel cell stack growth to accommodate more fuel cells. Similarly, reducing the size of the fuel cell stack creates increased installation space for tanks.

Therefore, for example, a smaller tank, such as that shown at 90', can replace tank 90. Additional fuel cells 184' may be added to the fuel cell stack so that the fuel cell stack extends from the cavity 176 into the cavity 20. Such an enlarged fuel cell stack is shown at 172'. In this way, the fuel cell stack 172' occupies a space that was previously occupied by the tank 90.

Up again 1 - 3 Referring to this, the fuel cell stack 172 provides electrical energy to the drive motor 192, which is operatively connected to the front wheels 196, 200. The drive motor is located under an HVAC unit which is in 1 is shown at 204. Individual rear hub motors 208, 212 drive the rear wheels 214 and 216, respectively. The front wheels 196, 200 are rotatably connected to a front suspension system 220 which is attached to the frame 10. The rear wheels 214, 216 are rotatably connected to a rear suspension system 224 which is attached to the frame 10. Each of the wheels has a tire mounted thereon.

Because the tanks 90, 94, 98 and the fuel cell stack 172 are located beneath the passenger compartment, the front end of the vehicle is provided with improved airflow in the area containing an engine in a conventional vehicle. Especially on 1 Referring to the vehicle 9, it includes a central radiator 230 and side radiators 234, 238 disposed on respective sides of the central radiator 230.

Although the best modes for carrying out the invention have been described in detail, those skilled in the art to which this invention relates will recognize various alternative designs and embodiments for carrying out the invention within the scope of the appended claims.

Claims (7)

Vehicle chassis (8), which includes: a frame (10) defining at least one cavity (20, 176), the at least one cavity (20, 176) comprising a first cavity (20) and a second cavity (176); at least one tank (90, 90', 94, 98) configured to store compressed hydrogen gas and disposed at least partially within the first cavity (20) and aligned lengthwise with respect to the frame (10); a floor panel (140) disposed over the first cavity (20) and the second cavity (176) and defining a hollow vault (170) which is at least partially cylindrical in shape; wherein the one tank (90, 90') or one of the plurality of tanks (90, 90', 94, 98) is partially arranged in the hollow vault (170); wherein the floor panel (140) at least partially defines a rigid floor surface (144) of a passenger compartment (142); wherein the floor panel (140) defines a bulge (152) in the rigid floor surface (144) opposite the hollow bulge (170); and wherein the rigid floor surface (144) is flat at a front end (160) of the passenger compartment (142). Vehicle chassis (8). Claim 1 , further comprising a fuel cell stack (172) operatively connected to the at least one tank (90, 90 ', 94, 98). Vehicle chassis (8). Claim 2 , wherein the one or more tanks (90, 90', 94, 98) is at least partially arranged in the first cavity (20) and the fuel cell stack (172) is at least partially arranged in the second cavity (176). Vehicle chassis (8). Claim 3 , wherein the first cavity (20) and the second cavity (176) are adjacent to one another. Vehicle chassis (8). Claim 2 , wherein the fuel cell stack (172) comprises a plurality of fuel cell plates operatively connected to one another, the fuel cell stack (172) being suitably arranged with respect to one of the tanks (90') or one of the plurality of tanks (90, 90', 94, 98), so that additional fuel cell plates can be effectively connected to the fuel cell stack (172) in the direction of this tank (90 '). Vehicle (9) comprising: a tank (90, 90', 94, 98) adapted to store compressed gas and oriented longitudinally with respect to the vehicle (9); a vehicle floor panel (140) having a first side which acts as a floor surface (144) which partially defines the floor of a passenger compartment (142), and a second side opposite the first side, the vehicle floor panel (140) being formed by a hollow curvature (170 ) on the second side in which the tank (90, 90') is partially arranged and a corresponding bulge (152) is marked on the first side opposite the hollow bulge (170); wherein the floor surface (144) at a front end (160) of the passenger compartment (142) is flat; a frame (10) having a first rail (14), a second rail (18) cooperating with the first rail (14) to at least partially define a first cavity (20) in which the tank (90, 90', 94, 98) is at least partially arranged; a third rail (22) external to the first rail (14) and cooperating with the first rail (14) to at least partially define a first lateral cavity (24) external to the first cavity (20); and a fourth rail (26) external to the second rail (18) cooperating with the second rail (18) to at least partially define a second lateral cavity (28) external to the first cavity (20); wherein the vehicle floor panel (140) at least partially covers the first cavity (20), the first side cavity (24) and the second side cavity (28). Vehicle (9) after Claim 6 , further comprising an underbody pan (134) operatively connected to the frame (10) below the first cavity (20).

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