WO2008125946A1

WO2008125946A1 - Vehicle

Info

Publication number: WO2008125946A1
Application number: PCT/IB2008/000866
Authority: WO
Inventors: Hiroshi Arisawa
Original assignee: Toyota Jidosha Kabushiki Kaisha
Priority date: 2007-04-11
Filing date: 2008-04-10
Publication date: 2008-10-23
Also published as: JP2008260382A

Abstract

The invention provides a vehicle (10) equipped with a predetermined component (110, HOA, HOB, HOC) for driving the vehicle, and an accommodation space constituting member (12, 12A, 12B, 12C, 14, 14A, 14B, 14C, 14D) provided on a floor surface portion of the vehicle to constitute an accommodation space for accommodating the predetermined component. The accommodation space constituting member has an inner wall inclined so as to form an acute angle with a floor surface of the vehicle in the accommodation space, and the predetermined component abuts face-to-face on at least part of the inclined inner wall of the accommodation space constituting member.

Description

VEHICLE

BACKGROUND OF THE INVENTION

1. Field of the Invention [0001] The invention relates to a vehicle, and more particularly, to an art for mounting a predetermined component for driving a vehicle on a floor surface portion of the vehicle.

2. Description of the Related Art

[0002] Electric vehicles mounted with a fuel cell system including a fuel cell as a power source have been developed. Various arts for mounting such an electric vehicle with various components (e.g., a fuel cell and the like) constituting a fuel cell system have been proposed.

[0003] For example, Japanese Patent Application Publication No. 2003-182379 (JP-A- 2003-182379) describes an art in the field of a type of an electric vehicle mounted with a fuel cell. According to this art, some of various components including the fuel cell, which constitute a fuel cell system, are disposed below a floor of the vehicle according to a predetermined sequence to enhance the stability of the behavior of the vehicle and make the fuel cell resistant to breakage even when the vehicle undergoes a head-on collision or a rear-end collision. In this art, the fuel cell is accommodated in a fuel cell system box, and temperature adjustment means and humidification means are disposed respectively on a front side and a rear side of the fuel cell in the fuel cell system box with respect to the vehicle. This fuel cell system box is disposed at a central position in a longitudinal direction of the vehicle. [0004] However, in the art described in Japanese Patent Application Publication No. 2003-182379 (JP-A-2003-182379), when an unexpectedly large impact force is generated upon a collision of the vehicle, the fuel cell and the like that are fixed in the fuel cell system box may leave their fixation positions, crash against an inner wall of the fuel cell system box, and deform or even break the fuel cell system box. This phenomenon is not limited to cases where a fuel cell system box is mounted below a floor (on a floor surface portion) of a type of an electric vehicle mounted with a fuel cell as in the case of the above-mentioned Japanese Patent Application Publication No. 2003-182379 (JP-A-2003- 182379), but is also common to cases where various components (including components other than a fuel cell) for driving a vehicle (which may not be a type of an electric vehicle mounted with a fuel cell) are mounted on a floor surface portion of the vehicle.

SUMMARY OF THE INVENTION [0005] In a vehicle equipped on a floor surface portion thereof with a component mounting portion mounted with various components for driving the vehicle, the invention provides an art for restraining members constituting the component mounting portion from being deformed or broken when the vehicle collides with another object. It should be noted that "the floor surface portion of the vehicle" means a region immediately above a floor surface of the vehicle, a region immediately below the floor surface, or a predetermined region at the same height as the floor surface.

[0006] A vehicle according to one aspect of the invention is equipped with a predetermined component for driving the vehicle, and an accommodation space constituting member provided on a floor surface portion of the vehicle to constitute an accommodation space for accommodating the component. The accommodation space constituting member has an inner wall inclined so as to form an acute angle with a floor surface of the vehicle in the accommodation space, and the predetermined component abuts face-to-face on at least part of the inclined inner wall of the accommodation space constituting member. [0007] Deformation or breakage of the accommodation space constituting member constituting the accommodation space in which the component is accommodated results from a force applied perpendicularly to an inner wall surface of the accommodation space constituting member. In this example of application, the inner wall of the accommodation space constituting member and the predetermined component abut face-to-face on each other. Therefore, for example, when an external force is substantially horizontally applied to the vehicle due to a collision between the vehicle and another object, an inertial force acting substantially horizontally with respect to the vehicle (in the opposite direction of the external force) is applied from the component to the accommodation space constituting member on an abutment region between the inner wall surface and the component. According to this aspect of the invention, the accommodation space constituting member has the inner wall inclined so as to form an acute angle with the floor surface of the vehicle in the accommodation space. Therefore, the inertial force applied to the inner wall surface is decomposed into a component force perpendicular to the inner wall surface and a component force parallel to the inner wall surface. Accordingly, the magnitude of the component force perpendicular to the inner wall surface is smaller than the magnitude of the inertial force. Further, the inner wall surface and the component abut face-to-face on each other. Therefore, the force applied to the inner wall surface per unit area is small. As a result, the accommodation space constituting member is restrained from being deformed or broken. Various components are applicable as the aforementioned "predetermined component". For example, a fuel cell, a battery, a fuel tank, and the like can be mentioned in the case where the vehicle is an electric vehicle. An excellent effect is achieved when the aforementioned "predetermined component" is relatively heavy in weight, because the inertial force is proportional to the weight of the component.

[0008] The inclined inner wall may be provided at least on a front side of the vehicle. This is because the vehicle more often undergoes a head-on collision than other types of collisions. In the vehicle, furthermore, the inclined inner wall may be provided on a rear side of the vehicle, a lateral side of the vehicle, or a oblique side of the vehicle. By adopting this construction, a collision from any direction can be coped with.

[0009] The accommodation space constituting member may include a front panel of the vehicle and a cover fastened to the floor panel, and at least one of the floor panel and the cover may have the inclined inner wall. By adopting this construction, the component mounting portion (the accommodation space for the component) can be easily formed on the floor surface portion of the vehicle. A member exhibiting relatively high rigidity is applied as the floor panel of the vehicle. Therefore, by applying this floor panel as the accommodation space constituting member having the inclined inner wall, the accommodation space constituting member is more effectively restrained from being deformed or broken than in a case where the cover is applied as the accommodation space constituting member having the inclined inner wall.

[0010] The accommodation space constituting member may include a floor panel of the vehicle that has the inclined inner wall, and a cover fastened to a region below the floor panel. The floor panel and the cover may be fastened to each other with a fastening force that is set such that the floor panel and the cover separate from each other when a force equal to or larger than a predetermined value is applied vertically downward to the cover.

[0011] As described above, an inertial force is applied from the component to the accommodation space constituting member when an external force is substantially horizontally applied to the vehicle due to, for example, a collision between the vehicle and another object. On an abutment region between the inner wall surface and the component, a drag of a component force of the inertial force that acts perpendicularly to the inner wall surface is applied to the component. The inner wall surface is inclined so as to form an acute angle with the floor surface of the vehicle. Therefore, this drag is decomposed into a horizontal component force acting in the opposite direction of the inertial force, and a vertical component force acting vertically downward. The fastening force between the floor panel and the cover is set such that the floor panel and the cover separate from each other when a force equal to or larger than the predetermined value is applied vertically downward to the cover. Therefore, the component and the cover can be made to fall from a main body of the vehicle when a force equal to or larger than the predetermined value is applied vertically downward to the cover, namely, when the vertical component force of the drag that acts vertically downward becomes equal to or larger than the predetermined value upon a collision of the vehicle or the like. Accordingly, the security of passengers of the vehicle is enhanced. [0012] The predetermined component may include a cushioning material disposed so as to abut on the inner wall. The cushioning material may absorb a force applied to the inner wall and a force applied to the component when an external force is substantially horizontally applied to the vehicle. By adopting this construction, the cushioning material absorbs the above-described inertial force, and the accommodation space constituting member is further restrained from being deformed or broken.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The foregoing and further objects, features and advantages of the invention will become apparent from the following description of example embodiments with reference to the accompanying drawings, wherein like numerals are used to represent like elements and wherein:

FIG. 1 is an illustrative view showing the overall construction of a vehicle as the first embodiment of the invention; FIG. 2 is a perspective view showing the exterior appearance of a fuel cell stack 110 in the first embodiment of the invention;

FIGS. 3 A and 3B are illustrative views showing the overall structure of a mounting portion 100 in the first embodiment of the invention;

FIGS. 4A and 4B are illustrative views showing an operation and an effect that are obtained by providing a vehicle 10 with the mounting portion 100;

FIGS. 5 A and 5B are illustrative views showing the overall structure of a mounting portion IOOA in the second embodiment of the invention;

FIGS. 6 A and 6B are illustrative views showing the overall structure of a mounting portion IOOB as a modification example of the first embodiment of the invention; FIG. 7 is an illustrative view showing the overall structure of a mounting portion IOOC as another modification example of the first embodiment of the invention;

FIG. 8 is an illustrative view showing the overall structure of a mounting portion IOOD as still another modification example of the first embodiment of the invention;

FIG. 9 is a perspective view showing the exterior appearance of a fuel cell stack HOB as a modification example; and

FIG. 10 is a perspective view showing the exterior appearance of a fuel cell stack HOC as another modification example.

DETAILED DESCRIPTION OF EMBODIMENTS

[0014] The embodiments of the invention will be described hereinafter. FIG. 1 is an illustrative view showing the overall construction of a vehicle as the first embodiment of the invention. This vehicle 10 is an electric vehicle having a motor, which is driven by power generated by a fuel cell (a later-described fuel cell stack 110) and power output from a battery, and designed to run with wheels rotated by a motive force of the motor. The power generated by the fuel cell stack 110 can also be stored in the battery. [0015] This vehicle 10 is equipped on a floor surface portion thereof with a mounting portion 100 for mounting the fuel cell stack 110. In this embodiment of the invention, as shown in FIG. 1, the mounting portion 100 is disposed below a seat installed in the vehicle 10. Although not shown, constituent parts constituting a fuel cell system including the fuel cell stack HO are disposed below a floor of the vehicle 10 and in spaces other than a passenger compartment of the vehicle 10, namely, regions in front of and behind the passenger compartment. The constituent parts constituting the fuel cell system include a hydrogen tank, an air compressor, a radiator, a diluter, a gas-liquid separator, various pipelines or the like, a control unit for controlling the fuel cell system, a battery, a motor, other electrical parts, and the like. The fuel cell stack 110 may be regarded as the predetermined component in the invention. Details of the mounting portion 100 will be described later. [0016] FIG. 2 is a perspective view showing the exterior appearance of the fuel cell stack HO in the first embodiment of the invention. As shown in FIG. 2, this fuel cell stack 110 is formed by stacking a plurality of single cells 112. The number of the stacked single cells 112 may be arbitrarily set in accordance with an output required of the fuel cell stack 110. [0017] In this fuel cell stack 110, collector plates (not shown) and insulator plates (not shown) are disposed in this order respectively at both ends of a stacked body composed of the plurality of the single cells 112 in a stacking direction thereof. Furthermore, end plates 114a and 114b are disposed respectively at both these ends. To ensure rigidity, the end plates 114a and 114b are formed of a metal such as steel or the like. Each of the collector plates is formed of a gas impermeable conductive member such as a piece of dense carbon or a copper plate. Each of the collector plates is provided with an output terminal (not shown) that outputs power generated by the fuel cell stack 110. Each of the insulator plates is formed of an insulating member such as a piece of rubber, resin, or the like. [0018] In the fuel cell stack 110 of this embodiment of the invention, as shown in FIG. 2, the end plate 114a assumes a planar shape of a hexagon having sides Sl to S6. In this embodiment of the invention, this hexagon is shaped such that the sides Sl and S2 are parallel to each other and that the upper side Sl is shorter than the lower side S2. The left side S3 and the right side S4 are parallel to each other, have the same length, and intersect with the side S2 at right angle. The angle formed by the sides Sl and S5 is equal to the angle formed by the sides Sl and S6. This angle is an obtuse angle. The end plate 114b is identical in shape to the end plate 114a. In this embodiment of the invention, the respective single cells 112 are homothetic to the end plates 114a and 114b, and assume planar shapes smaller than those of the end plates 114a and 114b. Accordingly, the end plates 114a and 114b protrude from an outer peripheral face of the stacked body composed of the plurality of the single cells 112. As will be described later, mount rubber pieces functioning as a cushioning material for absorbing an impact from the outside are installed on outer peripheral portions of the end plates 114a and 114b respectively. [0019] Although not shown or described in detail, the end plate 114a is provided with a fuel gas supply port (not shown), a fuel gas discharge port (not shown), an oxidant gas supply port (not shown), an oxidant gas discharge port (not shown), a coolant supply port (not shown), and a coolant discharge port (not shown). A plurality of supply manifolds for supplying hydrogen as a fuel gas, air as an oxidant gas, and coolant to the single cells 112 respectively in a distributive manner, and a plurality of discharge manifolds for gathering and then discharging to the outside of the fuel cell stack 110 an anode off gas and a cathode off gas that are discharged from anodes and cathodes of the single cells 112 respectively and coolant are formed inside the fuel cell stack 110. [0020] A fastening load is applied to the fuel cell stack 110 in the stacking direction thereof with a view to suppressing a deterioration in battery performance resulting from an increase in contact resistance at some spot of the fuel cell stack 110 or the like or preventing the leakage of gases flowing inside the fuel cell stack 110 or coolant. The fuel cell stack 110 is fastened by a fastening member (not shown). [0021] FIGS. 3 A and 3B are illustrative views showing the overall structure of the mounting portion 100 in the first embodiment of the invention. FIG. 3A shows a cross-section of the mounting portion 100 as viewed from a point on the left of the vehicle 10 (a cross-sectional view taken along a line IIIA-IIIA of FIG. 3B). In FIG. 3A, the front side of the vehicle 10 is shown on the left side, the rear side of the vehicle 10 is shown on the right side, the upper side of the vehicle 10 is shown on the upper side, and the lower side of the vehicle 10 is shown on the lower side. FIG. 3B shows a cross-section of the mounting portion 100 as viewed from a point above the vehicle 10 (a cross-sectional view taken along a line IIIB-IIIB of FIG. 3A). In FIG. 3B, the front side of the vehicle 10 is shown on the left side, the rear side of the vehicle 10 is shown on the right side, the right side of the vehicle 10 is shown on the upper side, and the left side of the vehicle 10 is shown on the lower side.

[0022] In this embodiment of the invention, the fuel cell stack 110 having mount rubber pieces 116a and 116b installed on the outer peripheral portions of the end plates 114a and 114b respectively is accommodated in an inner space (accommodation space) of the mounting portion 100. The fuel cell stack 110 is accommodated in the accommodation space inside the mounting portion 100 such that the stacking direction of the plurality of the single cells 112 in the fuel cell stack 110 coincides with the lateral direction of the vehicle 10. In some cases, several hundred layers of the single cells 112 are stacked in the fuel cell stack 110, and the fuel cell stack 110 is hence relatively long in the stacking direction thereof. Therefore, by disposing the fuel cell stack 110 in this manner, the vehicle 10 can be mounted with the fuel cell stack 110 while effectively utilizing a relatively narrow space below seats of the vehicle 10.

[0023] As shown in FIG. 3A, the mounting portion 100 of this embodiment of the invention is equipped with a floor panel 12 of the vehicle 10, and a cover 14 fastened to the floor panel 12 in a region therebelow. The floor panel 12 and the cover 14 form the accommodation space of the fuel cell stack 110. The floor panel 12 and the cover 14 are fastened to each other by a plurality of bolts 16 and a plurality of nuts 18. Each of the floor panel 12 and the cover 14 may be regarded as the accommodation space constituting member of the invention. In this embodiment of the invention, as will be described later, the fastening force acting between the floor panel 12 and the cover 14 is set such that the floor panel 12 and the cover 14 separate from each other due to breakage of the plurality of the bolts 16 and the plurality of the nuts 18 or the cover 14 when a force equal to or larger than a predetermined value is applied vertically downward to the cover 14.

[0024] In the mounting portion 100, as shown in FIG. 3A, the floor panel 12 corresponds to the sides Sl, S5, and S6 (see FIG. 2) of each of the end plates 114a and 114b of the fuel cell stack 110 illustrated above, and is so shaped as to abut on outer peripheral faces of the mount rubber pieces 116a and 116b. That is, in the accommodation space constituted by the floor panel 12 and the cover 14, the floor panel 12 constitutes inner walls that are each inclined at an acute angle from a floor surface (horizontal surface) of the vehicle 10 such that the accommodation space decreases in width vertically upward. Thus, outer peripheral faces on the sides S5 and S6 of each of the end plates 114a and 114b (the outer peripheral faces of the mount rubber pieces 116a and 116b) abut face-to-face on (or is in planer contact with) the inclined inner walls of the floor panel respectively. A recess portion 14c, which corresponds to the sides S2, S3, and S4 (see FIG. 2) of each of the end plates 114a and 114b of the fuel cell stack 110 and has the fuel cell stack 110 (including the mount rubber pieces 116a and 116b) fitted therein, is formed in the cover 14. [0025] In the mounting portion 100, as shown in FIG. 3B, the floor panel 12 is formed with a rib portion 12Ra in which the end plate 114a protruding from the outer peripheral face of the stacked body composed of the plurality of the single cells 112 in the fuel cell stack 110 and the mount rubber piece 116a are fitted, and a rib portion 12Rb in which the end plate 114b and the mount rubber piece 116b are fitted. An inner wall surface of the rib portion 12Ra abuts on the mount rubber piece 116a. An inner wall surface of the rib portion 12Rb abuts on the mount rubber pieces 116b. By adopting this construction, the position of the vehicle 10 where the fuel cell stack 110 is installed can be determined with ease. Further, the fuel cell stack 110 is prevented from being displaced in the lateral direction of the vehicle.

[0026] The floor panel 12 is formed such that a gap is created between the floor panel 12 and the single cells 112 when the fuel cell stack 110 is installed. By adopting this construction, insulation of the fuel cell stack 110 against the single cells 112 can be ensured. In the fuel cell stack 110 of this embodiment of the invention, the mount rubber pieces 116a and 116b are installed on the outer peripheral portions of the end plates 114a and 114b respectively. However, additional mount rubber pieces may be installed on an outer peripheral portion of at least part of the stacked body composed of the plurality of the single cells 112. [0027] FIGS. 4A and 4B are illustrative views showing an operation and an effect that are obtained by providing the vehicle 10 with the mounting portion 100. A case where the vehicle 10 undergoes a head-on collision will now be described. As shown in FIG. 4A, when the vehicle 10 undergoes a head-on collision, an inertial force F corresponding to an acceleration of the vehicle 10 at the time of the collision or a weight of the fuel cell stack 110 is applied to an arbitrary point P on the aforementioned inclined front inner wall surface of the floor panel 12 in the direction opposite to the collision, namely, forward with respect to the vehicle. Part of this inertial force F is absorbed by the mount rubber pieces 116a and 116b serving as cushioning materials. Although a frictional force actually acts between the floor panel 12 and the fuel cell stack 110 (the mount rubber pieces 116a and 116b), the description of this frictional force is omitted herein with a view to facilitating illustration and understanding.

[0028] This inertial force F is decomposed into a component force Fp acting perpendicularly to the inner wall surface of the floor panel 12 in the mounting portion 100, and a component force Fs acting parallel to the inner wall surface of the floor panel 12. Accordingly, the magnitude of the component force Fp as a force serving to deform the floor panel 12 is smaller than the magnitude of the inertial force F. As described above, in the mounting portion 100 of this embodiment of the invention, the aforementioned inclined inner walls of the floor panel 12 are formed respectively on the front side and the rear side of the vehicle 10. Therefore, when the vehicle 10 undergoes a rear-end collision, the aforementioned operation is produced in the same manner as in the case where the vehicle 10 undergoes a head-on collision. Therefore, according to the vehicle 10 of this embodiment of the invention, the floor panel 12 constituting the mounting portion 100 is restrained from being deformed or broken when the vehicle 10 undergoes a head-on collision or a rear-end collision. [0029] In the mounting portion 100 of the first embodiment of the invention, furthermore, an effect described below is also achieved. That is, as shown in FIG. 4A, a drag fp acting in the direction opposite to and having the same magnitude as the component force Fp of the aforementioned inertial force F is applied to the point P on the fuel cell stack 110. This drag fp is decomposed into a horizontal component force fpx acting backward with respect to the vehicle 10, and a vertical component force fpy acting vertically downward with respect to the vehicle 10. In the mounting portion 100 of this embodiment of the invention, as described above, the fastening force acting between the floor panel 12 and the cover 14 is set such that the floor panel 12 and the cover 14 separate from each other due to breakage of the plurality of the bolts 16 and the plurality of the nuts 18 or the cover 14 when a force equal to or larger than a predetermined value is applied vertically downward to the cover 14. Accordingly, when the sum of the vertical component force fpy (the sum of fpy) acting vertically downward as shown in FIG. 4A and a gravity G of the fuel cell stack 110 shown in FIG. 4A becomes larger than the fastening force acting between the floor panel 12 and the cover 14 due to a collision of the vehicle 10 or the like, the floor panel 12 and the cover 14 separate from each other as shown in FIG. 4B. As a result, the cover 14 and the fuel cell stack 110 fall. Thus, according to the vehicle 10 of this embodiment of the invention, the fuel cell stack 110 is prevented from moving within the passenger compartment of the vehicle 10 owing to the above-mentioned operation. Therefore, the security of passengers in the vehicle 10 is enhanced.

[0030] The vehicle 10 according to the second embodiment of the invention is identical to the vehicle 10 according to the first embodiment of the invention except in the structure of the mounting portion of the fuel cell stack, the shape of the fuel cell stack, and the like. Those details of the vehicle 10 according to the second embodiment of the invention which are different from the vehicle 10 according to the first embodiment of the invention will be described hereinafter.

[0031] FIGS. 5A and 5B are illustrative views showing the overall structure of a mounting portion IOOA in the second embodiment of the invention. FIG. 5A shows a cross-section of the mounting portion IOOA as viewed from a point on the left of the vehicle 10 (a cross-sectional view taken along a line VA-VA of FIG. 5B). In FIG. 5A, the front side of the vehicle 10 is shown on the left side, the rear side of the vehicle 10 is shown on the right side, the upper side of the vehicle 10 is shown on the upper side, and the lower side of the vehicle 10 is shown on the lower side. FIG. 5B shows a cross-section of the mounting portion IOOA as viewed from a point above the vehicle 100 (a cross-sectional view taken along a line VB-VB of FIG. 5A). In FIG. 5B, the front side of the vehicle 10 is shown on the left side, the rear side of the vehicle 10 is shown on the right side, the right side of the vehicle 10 is shown on the upper side, and the left side of the vehicle 10 is shown on the lower side. [0032] As is apparent from FIGS. 5A and 5B, in this embodiment of the invention, a fuel cell stack HOA assumes the outer shape of a generally rectangular parallelepiped. This fuel cell stack HOA is accommodated in a stack case 120 having the shape of a hexagonal column that is substantially identical to the outer shape of the fuel cell stack 110 of the first embodiment of the invention. However, the stack case 120 has no protruding portion corresponding to the shape of the end plates 114a and 114b of the fuel cell stack 110 in the first embodiment of the invention. The fuel cell stack HOA is fixed within the stack case 120 via a plurality of mount members 130 made of an insulating material. The stack case 120 accommodating the fuel cell stack HOA of this embodiment of the invention may be regarded as the predetermined component of the invention.

[0033] As is the case with the mounting portion 100 of the first embodiment of the invention, the mounting portion IOOA mounted with the fuel cell stack HOA of this embodiment of the invention is equipped with a floor panel 12A of the vehicle 10, and a cover 14A fastened to the floor panel 12A in a region therebelow. The floor panel 12A and the cover 14A form an accommodation space of the fuel cell stack HOA. The floor panel 12A and the cover 14A are fastened to each other by the plurality of the bolts 16 and the plurality of the nuts 18. In this embodiment of the invention as well as the first embodiment of the invention, the fastening force acting between the floor panel 12A and the cover 14A is set such that the floor panel 12A and the cover 14A separate from each other due to breakage of the plurality of the bolts 16 and the plurality of the nuts 18 or the cover 14A when a force equal to or larger than a predetermined value is applied vertically downward to the cover 14A. [0034] In the mounting portion IOOA, as shown in FIG. 5A, the floor panel 12A and the cover 14A assume such a shape as to abut on the stack case 120. That is, as is the case with the first embodiment of the invention, in an accommodation space formed by the floor panel 12A and the cover 14A, the floor panel 12A constitutes inner walls that are each inclined at an acute angle from the floor surface (horizontal surface) of the vehicle 10 such that the accommodation space decreases in width vertically upward. A recess portion 14Ac, which corresponds to the recess portion 14c formed in the cover 14 of the mounting portion 100 of the first embodiment of the invention and has the stack case 120 fitted therein, is formed in the cover 14A.

[0035] In the mounting portion IOOA, as shown in FIG. 5B, the floor panel 12A is formed with a recess portion 12Ac in which a top face of the stack case 120 and part of a lateral face (oblique face) of the stack case 120 are fitted. By adopting this construction, the position of the vehicle 10 where the stack case 120 is installed can be determined with ease. Further, the stack case 120 is prevented from being displaced in the lateral direction of the vehicle. [0036] In this embodiment of the invention, the stack case 120 is installed in the accommodation space constituted by the floor panel 12A and the cover 14A without the intervention of a cushioning material. However, a cushioning material made of rubber, urethane, or the like may be interposed between the stack case 120 and each of the floor panel 12A and the cover 14A. [0037] According to the vehicle 10 of the second embodiment of the invention described above as well, the mounting portion IOOA is substantially identical in structure to the mounting portion 100 in the first embodiment of the invention. Therefore, the force serving to deform the floor panel 12A (the component force Fp of the inertial force F in FIG. 4) is smaller than the inertial force F (see FIG. 4) when the vehicle 10 undergoes a head-on collision or a rear-end collision. Accordingly, the floor panel 12A constituting the mounting portion IOOA is restrained from being deformed or broken. [0038] In the vehicle according to the second embodiment of the invention as well, the fastening force acting between the floor panel 12A and the cover 14A is set such that the floor panel 12A and the cover 14A separate from each other due to breakage of the plurality of the bolts 16 and the plurality of the nuts 18 or the cover 14A when a force equal to or larger than a predetermined value is applied vertically downward to the cover 14A. Accordingly, as is the case with the first embodiment of the invention, the stack case 120 does not move within the passenger compartment of the vehicle 10 at the time of a collision thereof or the like. Therefore, the security of passengers in the vehicle 10 is enhanced.

[0039] While some embodiments of the invention have been illustrated above, it is to be understood that the invention is not limited to details of the illustrated embodiments, but may be embodied with various changes, modifications or improvements, which may occur to those skilled in the art, without departing from the spirit and scope of the invention. For example, some modified embodiments are described below. [0040] FIGS. 6 A and 6B are illustrative views showing the overall structure of a mounting portion IOOB as a modification example of the first embodiment of the invention. FIG. 6A shows a cross-section of the mounting portion IOOB as viewed from a point in front of the vehicle 10 (a cross-sectional view taken along a line VIA-VIA of FIG. 6B). In FIG. 6A, the right side of the vehicle 10 is shown on the left side, the left side of the vehicle 10 is shown on the right side, the upper side of the vehicle 10 is shown on the upper side, and the lower side of the vehicle 10 is shown on the lower side. FIG. 6B shows a cross-section of the mounting portion IOOB as_, viewed from a point above the vehicle 10 (a cross-sectional view taken along a line VIB-VIB of FIG. 6A). In FIG. 6B, the right side of the vehicle 10 is shown on the left side, the left side of the vehicle 10 is shown on the right side, the rear side of the vehicle 10 is shown on the upper side, and the front side of the vehicle 10 is shown on the lower side. [0041] The fuel cell stack 110 accommodated in the mounting portion IOOB is identical- to the fuel cell stack 110 in the first embodiment of the invention. However, this modification example is different from the first embodiment of the invention in the direction in which the fuel cell stack 110 is disposed. That is, the fuel cell stack 110 is accommodated in the accommodation space inside the mounting portion IOOB such that the longitudinal direction of the vehicle 10 coincides with the stacking direction of the plurality of the single cells 112 in the fuel cell stack 110. Thus, the mounting portion IOOB of this modification example has a structure described below. [0042] As shown in FIG. 6 A, the mounting portion IOOB of this modification example is equipped with a floor panel 12B of the vehicle 10, and a cover 14B fastened to the floor panel 12B in a region therebelow. The floor panel 12B and the cover 14B form the accommodation space of the fuel cell stack 110. As is the case with the mounting portion 100 in the first embodiment of the invention, the floor panel 12B and the cover 14B are fastened to each other by the plurality of the bolts 16 and the plurality of the nuts 18. In this modification example as well as the first embodiment of the invention, the fastening force acting between the floor panel 12B and the cover 14B is set such that the floor panel 12B and the cover 14B separate from each other due to breakage of the plurality of the bolts 16 and the plurality of the nuts 18 or the cover 14B when a force equal to or larger than a predetermined value is applied vertically downward to the cover 14B. [0043] In the mounting portion 10OB, as shown in FIG. 6A, the floor panel 12B corresponds to the sides Sl, S5, and S6 (see FIG. 2) of each of the end plates 114a and 114b of the fuel cell stack 110 illustrated above, and is so shaped as to abut on the outer peripheral faces of the mount rubber pieces 116a and 116b. That is, in the accommodation space constituted by the floor panel 12B and the cover 14B, the floor panel 12B constitutes inner walls that are each inclined at an acute angle from the floor surface (horizontal surface) of the vehicle 10 such that the accommodation space decreases in width vertically upward. A recess portion 14Bc, which corresponds to the sides S2, S3, and S4 (see FIG. 2) of each of the end plates 114a and 114b of the fuel cell stack 110 and has the fuel cell stack 110 (including the mount rubber pieces 116a and 116b) fitted therein, is formed in the cover 14B.

[0044] In the mounting portion 10OB, as shown in FIG. 6B, the floor panel 12B is formed with a rib portion 12BRa in which the end plate 114a protruding from the outer peripheral face of the stacked body composed of the plurality of the single cells 112 in the fuel cell stack 110 and the mount rubber piece 116a are fitted, and a rib portion 12BRb in which the end plate 114b and the mount rubber pieces 116b are fitted. An inner wall surface of the rib portions 12BRa abuts on the mount rubber piece 116a. An inner wall surface of the rib portion 12BRb abuts on the mount rubber pieces 116b. By adopting this construction, the position of the vehicle 10 where the fuel cell stack 110 is installed can be determined with ease. [0045] According to the vehicle 10 equipped with the mounting portion IOOB of this modification example described above, the mounting portion IOOB is substantially identical in structure to the mounting portion 100 in the first embodiment of the invention. Therefore, the force serving to deform the floor panel 12B (the component force Fp of the inertial force F in FIG. 4) is smaller than the inertial force F (see FIG. 4) when the vehicle 10 undergoes a side collision. Accordingly, the floor panel 12B constituting the mounting portion IOOB is restrained from being deformed or broken. [0046] In the vehicle 10 according to this modification example as well, the fastening force acting between the floor panel 12B and the cover 14B is set such that the floor panel 12B and the cover 14B separate from each other due to breakage of the plurality of the bolts 16 and the plurality of the nuts 18 or the cover 14B when a force equal to or larger than a predetermined value is applied vertically downward to the cover 14B. Accordingly, as is the case with the first embodiment of the invention, the fuel cell stack 110 does not move within the passenger compartment of the vehicle 10 at the time of a collision thereof or the like. Therefore, the security of passengers in the vehicle 10 is enhanced.

[0047] In the mounting portion 100 of the foregoing first embodiment of the invention, the floor panel 12 constitutes the inner walls that are each inclined at an acute angle from the floor surface (horizontal surface) of the vehicle 10 such that the accommodation space of the fuel cell stack 110 decreases in width vertically upward. However, the invention is not limited to this construction.

[0048] FIG. 7 is an illustrative view showing the overall structure of a mounting portion IOOC as another modification example of the first embodiment of the invention. As is the case with FIG. 3, FIG. 7 shows a cross-section of the mounting portion IOOC as viewed from a point on the left of the vehicle 10. In FIG. 7, the front side of the vehicle 10 is shown on the left side, the rear side of the vehicle 10 is shown on the right side, the upper side of the vehicle 10 is shown on the upper side, and the lower side of the vehicle 10 is shown on the lower side. [0049] As shown in FIG. 7, the mounting portion IOOC of this modification example is equipped with a floor panel 12C of the vehicle 10, and a cover 14C fastened to the floor panel 12C in a region thereabove. The floor panel 12C and the cover 14C form the accommodation space of the fuel cell stack 110. The fuel cell stack 110 accommodated in the mounting portion IOOC is identical to the fuel cell stack 110 of the first embodiment of the invention. The floor panel 12C and the cover 14C are fastened to each other by the plurality of the bolts 16 and the plurality of the nuts 18. [0050] As is apparent from a comparison with FIG. 3A, in the mounting portion IOOC of this modification example, the cover 14C corresponds to the sides Sl, S5, and S6 (see FIG. 2) of each of the end plates 114a and 114b of the fuel cell stack 110 illustrated above, and is so shaped as to abut on the outer peripheral faces of the mount rubber pieces 116a and 116b. That is, in the accommodation space constituted by the floor panel 12C and the cover 14C, the cover 14C constitutes inner walls that are each inclined at an acute angle from the floor surface (horizontal surface) of the vehicle 10 such that the accommodation space decreases in width vertically upward. A recess portion 12Cc, which corresponds to the sides S2, S3, and S4 (see FIG. 2) of each of the end plates 114a and 114b of the fuel cell stack 110 and has the fuel cell stack 110 (including the mount rubber pieces 116a and 116b) fitted therein, is formed in the floor panel 12C. [0051] According to the vehicle 10 equipped with the mounting portion IOOC described above as well, the mounting portion IOOC is substantially identical in structure to the mounting portion 100 in the first embodiment of the invention. Therefore, the force serving to deform the cover 14C (which corresponds to the component force Fp of the inertial force F in FIG. 4) is smaller than the inertial force F (see FIG. 4) when the vehicle 10 undergoes a head-on collision or a rear-end collision. Accordingly, the cover 14C constituting the mounting portion IOOC is restrained from being deformed or broken. [0052] The shape of the cover 14C is not limited to the shape shown in FIG. 7. FIG. 8 is an illustrative view showing the overall structure of a mounting portion IOOD as still another modification example of the first embodiment of the invention. As is the case with FIG. 7, FIG. 8 shows a cross-section of the mounting portion IOOD as viewed from a point on the left of the vehicle 10. In FIG. 8, the front side of the vehicle 10 is shown on the left side, the rear side of the vehicle 10 is shown on the right side, the upper side of the vehicle 10 is shown on the upper side, and the lower side of the vehicle 10 is shown on the lower side.

[0053] As is apparent from a comparison between FIG. 7 and FIG. 8, the mounting portion IOOC shown in FIG. 7 and the mounting portion IOOD shown in FIG. 8 are different from each other in that the cover 14C and a cover 14D are different in shape from each other. That is, as shown in FIG. 8, as is the case with the cover 14C in the mounting portion lOOC, in an accommodation space constituted by the floor panel 12C and the cover 14D, the cover 14D in the mounting portion IOOD has inner walls that are each inclined at an acute angle from the floor surface (horizontal surface) of the vehicle 10 such that the accommodation space decreases in width vertically upward, but has a portion thicker than the cover 14C. The mounting portion IOOC and the mounting portion IOOD are identical to each other in other details. By adopting this construction as well, the same effect as in the case of the mounting portion IOOC shown in FIG. 7 can be obtained.

[0054] That is, in the mounting portion IOOC or IOOD, it is appropriate for the cover 14C or 14D constituting the accommodation space of the fuel cell stack 110 to have inner walls that are each inclined at an acute angle from the floor surface (horizontal surface) of the vehicle 10 such that the accommodation space decreases in width vertically upward. This also holds true for the floor panel 12, 12A, or 12B in the mounting portion 100, 10OA, or IOOB described above.

[0055] Each of the mounting portion 100 in the first embodiment of the invention, the mounting portion IOOA in the second embodiment of the invention, and the mounting portions IOOB, IOOC, and IOOD in the modification examples, which have been described above, provides the fuel cell stack 110 or the stack case 120 with a structure for coping with a head-on collision, a rear-end collision, or a side collision of the vehicle 10. However, the invention is not limited to this construction. The mounting portion may provide the fuel cell stack 110 or the stack case 120 with a structure for coping with a head-on collision, a rear-end collision, a side collision, and also an oblique collision of the vehicle 10. Accordingly, the inner walls of the mounting portion may partially assume such a shape that each of the inner walls forms an acute angle with the floor surface (horizontal surface) of the vehicle 10 and that the accommodation space decreases in width vertically upward, for example, the shape of lateral faces of a polygonal truncated pyramid or a circular truncated cone. In this case, the fuel cell stack or the stack case is preferably shaped so as to correspond in shape to the inner walls of the above-mentioned mounting portion and abut face-to-face on the inner walls. [0056] As shown in FIG. 2, the fuel cell stack 110 in the foregoing first embodiment of the invention or the like is formed by stacking the end plates 114a and 114b having the hexagonal planar shape and the single cells 112 having the hexagonal planar shape on one another. However, the fuel cell stack may assume another shape. [0057] FIG. 9 is. a perspective view showing the exterior appearance of a fuel cell stack HOB as a modification example. As shown in FIG. 9, this fuel cell stack HOB is formed by stacking a plurality of single cells 112A having a rectangular planar shape on one another. Collector plates and insulator plates are disposed in this order respectively at both ends of a stacked body composed of the plurality of single cells 112A. Furthermore, the end plates 114a and 114b having the same hexagonal planar shape as the end plates 114a and 114b of the first embodiment of the invention are disposed respectively at both these ends. As is the case with the first embodiment of the invention, the mount rubber pieces 116a and 116b are installed on the outer peripheral portions of the end plates 114a and 114b respectively. By the fuel cell stack HOA thus constructed as well, an effect similar to that of the fuel cell stack HO of the first embodiment of the invention can be achieved. [0058] FIG. 10 is a perspective view showing the exterior appearance of a fuel cell stack HOC as another modification example. As shown in FIG. 10, this fuel cell stack HOC has mount rubber pieces 116Ca and 116Cb, which are substantially identical in outer shape to the end plates 114a and 114b having the hexagonal planar shape in the fuel cell stack HO of the first embodiment of the invention, installed respectively on outer peripheral portions of end plates in the fuel cell stack HOA having the outer shape of the rectangular parallelepiped as in the second embodiment of the invention. By the fuel cell stack HOC thus constructed as well, an effect similar to that of the fuel cell stack HO of the first embodiment of the invention can be achieved.

[0059] In each of the foregoing first embodiment of the invention and the foregoing second embodiment of the invention, the cover 14 or 14A is provided with the recess portion 14c or 14Ac in the mounting portion 100 or 10OA. However, the recess portion 14c or 14Ac may be omitted. In this case, it is appropriate for the fuel cell stack 110 or the stack case 120 to generally assume the shape of a trapezoidal prism corresponding to the internal shape of the mounting portion 100 or 10OA. [0060] In each of the foregoing embodiments of the invention and the modification examples thereof, the case where the fuel cell stack is mounted on the mounting portion of the vehicle 10 has been described. However, the invention is not limited to this case. The invention is applicable to a mounting portion for mounting other components for driving the vehicle 10, such as a battery, a fuel tank, a motor, and the like. [0061] In each of the foregoing embodiments of the invention, the mounting portion is disposed below the seats of the vehicle 10, but the invention is not limited to this construction. The position of the vehicle 10 where the mounting portion is disposed can be arbitrarily set. However, from the standpoint of running stability of the vehicle 10, it is preferable to dispose the mounting portion in consideration of the weight balance of the vehicle 10.

Claims

1. A vehicle comprising: a predetermined component for driving the vehicle; and an accommodation space constituting member provided on a floor surface portion of the vehicle to constitute an accommodation space for accommodating the predetermined component, wherein the accommodation space constituting member has an inner wall inclined so as to form an acute angle with a floor surface of the vehicle in the accommodation space, and the predetermined component abuts face-to-face on at least part of the inclined inner wall of the accommodation space constituting member.

2. The vehicle according to claim 1, wherein the inclined inner wall is provided at least on a front side of the vehicle.

3. The vehicle according to claim 1 or 2, wherein the accommodation space constituting member includes a floor panel of the vehicle and a cover fastened to the floor panel, and at least one of the floor panel and the cover has the inclined inner wall.

4. The vehicle according to claim 1 or 2, wherein the accommodation space constituting member includes a floor panel of the vehicle that has the inclined inner wall, and a cover fastened to a region below the floor panel, and the floor panel and the cover are fastened to each other with a fastening force that is set such that the floor panel and the cover separate from each other when a force equal to or larger than a predetermined value is applied vertically downward to the cover.

5. The vehicle according to any one of claims 1 to 4, wherein the predetermined component includes a cushioning material disposed so as to abut on the inner wall, and the cushioning material absorbs a force applied to the inner wall and a force applied to the predetermined component when an external force is substantially horizontally applied to the vehicle.

6. The vehicle according to any one of claims 1 to 5, wherein the predetermined component includes at least one of a fuel cell, a battery, and a fuel tank.

7. The vehicle according to any one of claims 1 to 5, wherein the predetermined component includes a stacked body obtained by stacking a plurality of single cells of a fuel cell, and end plates disposed respectively at both ends of the stacked body in a stacking direction thereof, and the end plates have outer peripheral faces abutting face-to-face on the inclined inner wall.

8. The vehicle according to any one of claims 1 to 5, wherein the predetermined component includes a stacked body obtained by stacking a plurality of single cells of a fuel cell, and a stack case for accommodating the stacked body, and the stack case has an outer peripheral face abutting face-to-face on the inclined inner wall.

9. The vehicle according to claim 7, wherein the end plates each assume a planar shape of a hexagon including an upper side and a lower side that are parallel to each other, a right side and a left side that extend perpendicularly upward from the lower side and are parallel to each other, a first oblique side connecting an upper end of the right side to one end of the upper side, and a second oblique side connecting an upper end of the left side to the other end of the upper side, and the inclined inner wall includes a first inclined inner wall and a second inclined inner wall that abut face-to-face on the first oblique side and the second oblique side respectively.

10. The vehicle according to claim 5, wherein the predetermined component includes a stacked body obtained by stacking a plurality of single cells of a fuel cell, assuming a rectangular planar shape, and rectangular end plates disposed respectively at both ends of the stacked body in a stacking direction thereof, and the cushioning material includes an outer peripheral portion provided on an outer peripheral portion of each of the end plates to abut face-to-face on the inclined inner wall.

11. The vehicle according to claim 7, wherein the end plate protrudes from an outer peripheral face of the stacked body, and the inclined inner wall has a rib portion in which the end plate protruding from the peripheral face of the stacked body is fitted.

12. The vehicle according to claim 8, wherein the inclined inner wall has a recess portion in which a portion of the stack case is fitted.

13. The vehicle according to any one of claims 7 to 12, wherein the predetermined component is disposed in the vehicle such that the stacking direction substantially coincides with a lateral direction of the vehicle.

14. The vehicle according to claim 9, wherein each single cell is homothetic to the end plates and is planer shape smaller than the end plates.

15. The vehicle according to claim 3, wherein the cover is fastened to a region above the floor panel and has the inclined inner wall, and the thickness of the cover varies.