Patent Application
20150197165
The present invention relates to a fuel cell vehicle.
In recent years, as a counter-measure against global warming and the future depletion of petroleum, fuel cell vehicles that drive using electric power supplied from a fuel cell system are under development. Such fuel cell vehicle has a fuel cell stack in which a plurality of fuel cells is connected in series, and a boost converter that outputs electric power by increasing output voltage of the fuel cell stack.
Usually, both the fuel cell stack and the boost converter are arranged in a space below the floor panel in order to ensure a large seating space for passengers. As described in Patent Document 1 indicated below, one possible arrangement is for the fuel cell stack and boost converter to be stored in a single housing and the housing to be arranged in a space below the floor panel.
However, a protection bar for suppressing distortion of the vehicle in a side crash is arranged below the floor panel in the left-right direction of the vehicle. Thus, when the fuel cell stack and boost converter are stored in a single large housing, arranging such housing in a space below the floor panel is difficult because the housing and the protection bar interfere with each other.
In order to avoid interference with the protection bar, it is necessary to store the fuel cell stack in a different casing (fuel cell casing) from that of the boost converter and to arrange the fuel cell casing rearward of the protection bar in the vehicle while arranging the boost converter forward of the protection bar in the vehicle. The reason for arranging the boost converter forward of the fuel cell stack in the vehicle is that the electric power output from the boost converter need to be supplied to a traction motor which is arranged at the front of the vehicle.
The fuel cell stack and boost converter arranged as set forth above need to be electrically connected to each other in a space therebetween, namely, a space above or below the protection bar. Here, the mass of the fuel cell stack is larger than that of the boost converter, and the fuel cell stack and boost converter accordingly have different vibration systems (natural frequencies) from each other. Thus, from the point of view of the durability of their electrical connection alone, connecting them with a flexible braided bus bar is one option. However, braided bus bars are expensive and it is thus desirable to use a plate-like bus bar from the viewpoint of suppressing an increase in cost.
Considering the above, in a practical and desirable configuration, the fuel cell casing and the boost converter are fastened and fixed to each other in a space above or below the protection bar, and electrically connected to each other using a plate-like bus bar, in such a manner that the fuel cell casing and the boost converter vibrate as a unit wherever possible (i.e. their vibration systems conform to each other).
Patent Document 1: JP2007-207582 A
However, the spaces above and below the protection bar arranged in the left-right direction of the vehicle are narrow and it is difficult to ensure a sufficient height. Consequently, when the fuel cell casing and the boost converter are fastened and fixed to each other in such narrow space, it is difficult to ensure sufficient strength for suppressing each of them from individually vibrating.
For example, one possible configuration is for a first fastening part extending above the protection bar toward the front of the vehicle to be formed for the fuel cell casing, a second fastening part extending above the protection bar toward the rear of the vehicle to be formed for the boost converter, and the first and second fastening parts to be fastened and fixed to each other with their tips brought into contact with each other. In this configuration, the fastening surface is formed in the vertical direction. However, as described above, in the space above the protection bar, it is difficult to ensure a sufficient length of such fastening surface in the vertical direction. As a result, the vertical distance between the bolts is reduced and sufficient fastening strength cannot be attained. In addition, the bolts for fastening need to be inserted in the horizontal direction in this configuration and this makes it difficult to carry out the fastening operation from above a front panel, which is also a problem.
The present invention has been made in view of the above-described problems. An object of the present invention is to provide a fuel cell vehicle in which a fuel cell casing and a boost converter can be fastened and fixed to each other with sufficient strength in a space above or below a protection bar which is arranged in the left-right direction of the vehicle.
In order to solve the above problems, a fuel cell vehicle according to the present invention comprises: a fuel cell stack; a fuel cell casing storing the fuel cell stack therein; and a boost converter arranged forward of the fuel cell casing in the vehicle, the boost converter outputting electric power by increasing output voltage of the fuel cell stack, wherein a protection bar is arranged between the fuel cell casing and the boost converter in the left-right direction of the vehicle, and wherein a first fastening part, which is a part of the fuel cell casing, and a second fastening part, which is a part of the boost converter, are fastened and fixed to each other, with one being vertically superimposed on the other, in a space above or below the protection bar.
In the present invention, a first fastening part, being a part of the fuel cell casing, and a second fastening part, being a part of the boost converter, are fastened and fixed to each other, with one being vertically superimposed on the other, in a space above or below the protection bar, and thus, the fastening surface therebetween extends not vertically but horizontally. Accordingly, even in a space above or below the protection bar in which a sufficient height cannot be ensured, it is possible to make the fastening surface large and ensure sufficient fastening strength between the fuel cell casing and the boost converter.
Furthermore, since the fastening surface extends horizontally, fastening bolts are inserted vertically, and thus, the fastening operation can be easily performed from above a front panel.
In the fuel cell vehicle according to the present invention, it is preferable for the first fastening part and the second fastening part to be fastened and fixed to each other, with one being superimposed on the other so that the first fastening part is below the second fastening part.
The fuel cell casing storing the fuel cell stack is larger in both mass and shape than the boost converter. Thus, when installing such fuel cell casing and boost converter into the fuel cell vehicle, it is desirable to install the fuel cell casing first and then install the boost converter by performing alignment, etc.
In the above preferable mode, the first fastening part and the second fastening part are fastened and fixed to each other with one being superimposed on the other so that the first fastening part is below the second fastening part. This means that the fuel cell casing which is large in mass and shape is installed first and the boost converter is installed next, which makes the installation operation easy.
In the fuel cell vehicle according to the present invention, it is also preferable that: the first fastening part has a raised part that protrudes toward the boost converter; the second fastening part has a recessed part that retracts in a direction opposite to the fuel cell casing; and the first fastening part and the second fastening part are fastened and fixed to each other with the raised part and the recessed part being engaged with each other.
In this preferable mode, the first fastening part of the fuel cell casing has a raised part protruding toward the boost converter, while the second fastening part of the boost converter has a recessed part retracting in a direction opposite to the fuel cell casing. With this configuration, when the boost converter is fastened and fixed to the fuel cell casing, alignment therebetween can be performed by engaging the recessed part of the second fastening part with the raised part of the first fastening part. In other words, the recessed part of the second fastening part is guided by the raised part of the first fastening part, and as a result, the operation of fastening and fixing the boost converter to the fuel cell casing, while aligning the same, can be easily performed.
In the fuel cell vehicle according to the present invention, it is also preferable for the raised part to be formed such that a length thereof in the left-right direction of the vehicle gradually increases from the top down of the vehicle.
When fastening and fixing the boost converter to the fuel cell casing, the alignment therebetween in the left-right direction of the vehicle is performed by engaging the recessed part of the second fastening part with the raised part of the first fastening part. In order to perform such alignment with high accuracy, the raised part and the recessed part are desirably configured so as to be engaged with each other with a small gap therebetween in the left-right direction of the vehicle. However, if the gap between the raised part and the recessed part is small, the operation of engagement itself is rather difficult to perform, and this is a problem.
In this preferable mode, the raised part is formed such that the length thereof in the left-right direction of the vehicle gradually increases from the top down of the vehicle. When fastening and fixing the boost converter to the already-installed fuel cell casing, if the raised part and the recessed part are engaged with each other at a position higher than the final fastening/fixation position, the engagement therebetween can be easily performed because the gap therebetween in the left-right direction of the vehicle is relatively large. When the boost converter is thereafter moved down with the raised part and the recessed part being kept engaged, the gap between the raised part and the recessed part gradually decreases (and the boost converter is guided to the accurate position) and, finally, a small gap is left therebetween. As stated above, in this preferable mode, the operation of fastening and fixing the boost converter and the fuel cell casing, while aligning the same with a high degree of accuracy, can be easily performed.
In the fuel cell vehicle according to the present invention, it is also preferable for the raised part to have an internal space formed therein.
In this preferable mode, the internal space formed within the raised part can be effectively used as a space for wiring, pipes, etc.
In the fuel cell vehicle according to the present invention, it is also preferable for a part of a bus bar for extracting electric power from the fuel cell stack to be arranged in the internal space.
In this preferable mode, a part of a bus bar for extracting electric power from the fuel cell stack and supplying it to the boost converter is arranged in the internal space formed within the raised part. By using the internal space formed within the raised part as a space for routing the bus bar, the limited space within the fuel cell vehicle can be used more effectively.
In the fuel cell vehicle according to the present invention, it is also preferable for a control unit for controlling the fuel cell stack to be arranged in the internal space.
In this preferable mode, a control unit for controlling the fuel cell stack is arranged in the internal space formed within the raised part. By using the internal space formed within the raised part as a space for storing the control unit, the limited space within the fuel cell vehicle can be used more effectively.
According to the present invention, a fuel cell vehicle can be provided in which a fuel cell casing and a boost converter can be fastened and fixed to each other with sufficient strength in a space above or below a protection bar which is arranged in the left-right direction of the vehicle.
Hereinafter, embodiments of the present invention will be described, with reference to the attached drawings. To facilitate understanding of the descriptions, the same elements will be given the same reference signs wherever possible in each drawing and repetitive descriptions will be omitted.
Firstly, the configuration of a fuel cell vehicle which is an embodiment of the present invention will be described with reference to
In the below description, unless otherwise specified, the term “forward” means the travelling direction of the fuel cell vehicle 1 (the direction referred to as “FR” in
The fuel cell apparatus 2 is an apparatus that generates electric power for driving the fuel cell vehicle 1 and it is arranged below the floor panel of the fuel cell vehicle 1. A part (top part) of the fuel cell apparatus 2 is arranged within the center tunnel formed between a driver's seat 8 and a front passenger's seat 9.
The fuel cell apparatus 2 has a configuration in which a fuel cell stack, formed by stacking a plurality of fuel cells (unit cells) and electrically connecting them in series, is stored within a fuel cell casing 200. Each unit cell is, for example, a polymer electrolyte type fuel cell, having a structure in which: an air electrode is provided on one surface of an electrolyte membrane, being an ion exchange membrane; a fuel electrode is provided on the other surface of the electrolyte membrane; and a pair of separators is provided to sandwich the air electrode and fuel electrode therebetween. In such cells, hydrogen gas is supplied to a hydrogen gas passage of one separator and oxidant gas is supplied to an oxidant gas passage of the other separator, and electric power is generated through chemical reaction between these reactant gases.
A plurality of unit cells is stacked in the left-right direction of the fuel cell vehicle 1. An auxiliary device unit AU storing auxiliary devices, such as a fuel gas pump, therein, is connected and fixed to one end of the fuel cell casing 200 in the unit cell stacking direction (an end on the right side of the fuel cell vehicle 1).
The fuel tank 3 is a tank for storing hydrogen gas to be supplied to the fuel cell apparatus 2 and the fuel tank 3 is arranged at the rear part of the fuel cell vehicle 1. The flow rate of the hydrogen gas supplied from the fuel tank 3 to the fuel cell apparatus 2 is controlled by a control apparatus and a flow rate regulating valve, etc., which are not shown in the drawing, in accordance with the required power which is determined by, for example, the degree of opening of the accelerator.
The DC-DC converter 4 is a direct-current voltage converter and has a function of increasing the direct-current voltage of the power input from the fuel cell apparatus 2 (the output voltage of the fuel cell stack) and outputting the resulting power to the inverter 5. In this embodiment, the DC-DC converter 4 is arranged below the floor panel of the fuel cell vehicle 1 and within the center tunnel formed between the driver's seat 8 and the front passenger's seat 9. The DC-DC converter 4 is arranged forward of the fuel cell apparatus 2, in a state of being stored in an FDC container 400.
A protection bar PL is arranged below the floor panel in the left-right direction of the fuel cell vehicle 1 so as to suppress distortion of the vehicle in a side crash. Although several protection bars PL are arranged below the floor panel,
Owing to this, a large space extending continuously in the front-back direction of the fuel cell vehicle 1 cannot be obtained in the space below the floor panel. As a result, as shown in
In
The inverter 5 has a function of converting the direct-current power output from the DC-DC converter 4 to a three-phase alternating-current power and supplying the obtained power to the traction motor 6. The inverter 5 is adapted to operate by receiving an input voltage of 650 V, which is greater than the output voltage of the fuel cell apparatus 2. Since the DC-DC converter 4 is arranged between the fuel cell apparatus 2 and the inverter 5, the DC-DC converter 4 plays a role of bridging the gap between the output voltage of the fuel cell apparatus 2 and the input voltage at which the inverter 5 can operate.
The traction motor 6 is an electromagnetic motor that is supplied with three-phase alternating-current power output from the inverter 5 and generates a driving force for driving the fuel cell vehicle 1. The driving force generated by the traction motor 6 is regulated by a control device (not shown in the drawing) calculating required power based on the degree of opening of the accelerator, etc., and controlling the output power of the fuel cell apparatus 2 and the output power of the inverter 5 based on the calculated required power.
The radiator 7 is a device for cooling the fuel cell apparatus 2, the DC-DC converter 4, the traction motor 6, etc., which constitute the fuel cell vehicle 1. The radiator 7 causes a cooling medium to circulate between the radiator and the respective devices to be cooled through pipes, which are not shown in
Next, the specific shape of the fuel cell casing 200 will be described with reference to
The auxiliary device unit AU connected and fixed to a side surface of the fuel cell casing 200 has, when seen from the side of the fuel cell vehicle 1, approximately the same outer shape as the fuel cell casing 200. Thus, the fuel cell casing 200 and the auxiliary device unit AU can be regarded as forming one substantially rectangular cuboid shape together.
The fuel cell casing 200 has a horizontal FC seal surface 203 which is formed at a position close to the forward end of the fuel cell casing 200 and lower than the top surface of the fuel cell casing 200. On the FC seal surface 203, a substantially rectangular through-hole 204 is formed so that the long side thereof is aligned with the left-right direction of the fuel cell vehicle 1. Two bus bars (FC bus bars 201 and 202), serving as terminals for outputting the electric power generated by the fuel cell apparatus 2 toward the DC-DC converter 4, are arranged so as to be lined up in the left-right direction of the fuel cell vehicle 1 and these FC bus bars protrude upward from the through-hole 204. The FC bus bars 201 and 202 respectively have fastening bolt holes 220 and 221, each being formed at the tip thereof, close to the center.
A service plug SP serving as a safety device is arranged at an upper portion of the fuel cell casing 200 and in the center in the left-right direction of the fuel cell vehicle 1 (in other words, at the center portion of the substantially rectangular cuboid shape including the fuel cell casing 200 and the auxiliary device unit AU). The service plug SP has a pull-out plug, which is not shown in the drawing, and if an operator pulls out the pull-out plug, the fuel cell apparatus 2 can be electrically disconnected from the FC bus bars 201 and 202. The service plug SP protrudes upward of the fuel cell casing 200 and a part thereof is arranged in an internal space of the center tunnel of the fuel cell vehicle 1.
The service plug SP is connected to the FC bus bars 201 and 202 via an internal bus bar, not shown in the drawing. The internal bus bar is stored within an FC bus bar casing 205 so as not be exposed to the outside of the fuel cell casing 200. The FC bus bar casing 205 is arranged so as to extend from the top surface of the fuel cell casing 200 toward the forward side surface of the fuel cell casing 200. The FC bus bar casing 205 has: a first horizontal part 205a arranged between the service plug SP and the fuel cell casing; a vertical part 205b, extending downward from the forward end of the first horizontal part 205a; and a second horizontal part 205c, extending forward from the lower end of the vertical part 205b. The first horizontal part 205a, the vertical part 205b and the second horizontal part 205c each have an internal space formed therein and they communicate with each other.
In the FC bus bar casing 205, it should be noted that, in addition to the internal bus bar, a control unit for performing control of the overall operation of the fuel cell apparatus 2, such as control of the power generation by the fuel cell stack, may further be arranged in the internal space of the vertical part 205b. Further, other components may also be arranged so as to effectively use the internal space of the FC bus bar casing 205.
The width of the vertical part 205b in the left-right direction is greater than that of the first horizontal part 205a but is smaller than the entire width of the fuel cell casing 200. Further, both of the right and left side surfaces of the vertical part 205b are slightly inclined so that each upper end approaches the center. Accordingly, the length (width) of the vertical part 205b in the left-right direction gradually increases from the top down.
The forward side surface of the vertical part 205b is perpendicular to the front-back direction of the fuel cell vehicle 1. As shown in
The second horizontal part 205c has, on a top surface thereof, the above-described FC seal surface 203 and through-hole 204. In the internal space of the second horizontal part 205c, the FC bus bars 201 and 202 protruding upward from the through-hole 204 are connected to the internal bus bar extending from the service plug SP.
A service hole is formed on the forward side surface of the second horizontal part 205c, through the internal space of the second horizontal part 205c, and a service cover 206 covers the service hole. The service hole is an opening formed for the purpose of performing the operation of fastening and fixing the FC bus bar 201, etc., to the internal bus bar within the second horizontal part 205c.
The service cover 206 is fixed to the second horizontal part 205c with bolts BT1 and BT2, so that the bolts BT1 and BT2 protrude forward from the forward side surface of the second horizontal part 205c.
The fuel cell casing 200 has fastening bases 207 and 208 which are formed so as to sandwich the second horizontal part 205c from the right and left sides thereof. The fastening base 207 is located on the right side of the second horizontal part 205c and has a horizontal fastening surface 209 at the same level as the FC seal surface 203. Three internally threaded bolt insertion holes 210a, 210b and 210c are formed on the fastening surface 209. Of these, the bolt insertion holes 210a and 210b are formed so as to make a line in the front-back direction of the fuel cell vehicle 1. Meanwhile, the rearmost bolt insertion hole 210c on the fastening surface 209 is formed at a position inside (left side) of the line made by the bolt insertion holes 210a and 210b. Further, a lower end of a shaft 211 is fixed to the fastening surface 209 at a position on the extended line of the line made by the bolt insertion holes 210a and 210b and rearward of the bolt insertion holes 210a and 210b. The shaft 211 is a cylindrical metal shaft and it is fixed perpendicularly to the fastening surface 209 so that the center axis thereof extends in the vertical direction.
Instead of providing the shaft 211 on the extended line of the line made by the bolt insertion holes 210a and 210b, the shaft 211 may be provided forward of the bolt insertion hole 210c. In other words, the shaft 211 may be arranged so that the lower end of the shaft 211 and the bolt insertion hole 210c make a line extending in the front-back direction of the fuel cell vehicle 1.
The left side surface of the portion of the fastening base 207, where the bolt insertion holes 210a and 210b are formed, is spaced apart from the right side surface of the second horizontal part 205c, so that a gap 212 is formed therebetween.
The fastening base 208 is located on the left side of the second horizontal part 205c and has a horizontal fastening surface 213 at the same level as the FC seal surface 203. Three internally threaded bolt insertion holes 214a, 214b and 214c are formed on the fastening surface 213. Of these, the bolt insertion holes 214a and 214b are formed so as to make a line in the front-back direction of the fuel cell vehicle 1. Meanwhile, the rearmost bolt insertion hole 214c on the fastening surface 213 is formed at a position inside (right side) of the line made by the bolt insertion holes 214a and 214b. Further, a lower end of a shaft 215 is fixed to the fastening surface 213 at a position on the extended line of the line made by the bolt insertion holes 214a and 214b and rearward of the bolt insertion holes 214a and 214b. The shaft 215 is a cylindrical metal shaft and it is fixed perpendicularly to the fastening surface 213 so that the center axis thereof extends in the vertical direction. The shaft 215 has the same length as that of the shaft 211.
Instead of providing the shaft 215 on the extended line of the line made by the bolt insertion holes 214a and 214b, the shaft 215 may be provided forward of the bolt insertion hole 214c. In other words, the shaft 215 may be arranged so that the lower end of the shaft 215 and the bolt insertion hole 214c make a line extending in the front-back direction of the fuel cell vehicle 1.
The right side surface of the portion of the fastening base 208, where the bolt insertion holes 214a and 214b are formed, is spaced apart from the left side surface of the second horizontal part 205c, so that a gap 216 is formed therebetween.
On the forward side surface of the fuel cell casing 200, two FC ribs 217 and 218 are formed so as to protrude forward. The FC ribs 217 and 218 are thin plates arranged so as to be parallel to each other and facing each other. The FC ribs 217 and 218 are formed at positions for allowing the fastening bases 207 and 208 to be sandwiched therebetween. In other words, the FC rib 217 is formed at a position on the right side of the fastening base 207 and the FC rib 218 is formed at a position on the left side of the fastening base 208.
Referring next to
The DC-DC converter 4 is a direct-current voltage converter including several reactors (coils), switching circuits, capacitors, etc., and these components are stored inside the FDC container 400 composed of an FDC casing 401 and an FDC cover 402. The FDC casing 401 has an opening on the top and serves as a casing that supports the components of the DC-DC converter 4 from the bottom. A horizontal top seal surface is formed at the upper end of the FDC casing 401. The FDC cover 402 is a cap to cover the top opening of the FDC casing 401 and is fastened and fixed to the FDC casing 401 in a state where the lower end of the FDC cover 402 is in contact with the top seal surface of the FDC casing 401.
A plate-like FDC flange 403 is formed at the upper end and rear side of the FDC casing 401, so as to horizontally protrude rearward. As will be described later below, when fastening and fixing the DC-DC converter 4 to the fuel cell casing 200, the FDC flange 403 serves as a portion which is to be superimposed on the fastening surfaces 209 and 213 of the fuel cell casing 200 from above and fastened and fixed to those fastening surfaces.
The FDC flange 403 has six bolt through-holes 410a, 410b, 410c, 414a, 414b and 414c which are formed vertically therethrough. Of these, the bolt through-holes 410a and 410b are formed at a portion close to the right end of the FDC flange 403 so as to be lined up in the front-back direction of the fuel cell vehicle 1. The bolt through-hole 410c is formed rearward of, and to the left (close to the center) of the bolt through-holes 410a and 410b. The bolt through-holes 414a and 414b are formed at a portion close to the left end of the FDC flange 403 so as to be lined up in the front-back direction of the fuel cell vehicle 1. The bolt through-hole 414c is formed rearward of, and to the right (close to the center) of the bolt through-holes 414a and 414b.
These bolt through-holes 410a, 410b, 410c, 414a, 414b and 414c are formed, when seen from above in a state where the DC-DC converter 4 is fastened and fixed to the fuel cell casing 200, at the same positions as the bolt insertion holes 210a, 210b, 210c, 214a, 214b and 214c, respectively. As can be clearly seen from the above descriptions, the DC-DC converter 4 and the fuel cell casing 200 are fixed to each other by aligning the bolt insertion holes 210a, etc., with the bolt through-holes 410a, etc., and then inserting bolts into the holes from above and tightening the bolts.
A shaft through-hole 411 is formed in the FDC flange 403 at a position on the extended line of the line made by the bolt through-holes 410a and 410b and rearward of the bolt through-holes 410a and 410b. Similarly, a shaft through-hole 415 is formed in the FDC flange 403 at a position on the extended line of the line made by the bolt through-holes 414a and 414b and rearward of the bolt through-hole 414a and 414b. The shaft through-holes 411 and 415 are formed, when seen from above in a state where the DC-DC converter 4 is fastened and fixed to the fuel cell casing 200, at the same positions as the shafts 211 and 215, respectively.
At the center part in the left-right direction of the FDC flange 403, a substantially rectangular through-hole 420 is formed so that the long side thereof is aligned with the left-right direction of the fuel cell vehicle 1. The through-hole 420 is formed so as to have substantially the same shape as that of the through-hole 204 in the fuel cell casing 200. Further, the through-hole 420 is formed, when seen from above in a state where the DC-DC converter 4 is fastened and fixed to the fuel cell casing 200, at the same position as that of the through-hole 204.
Inside the through-hole 420, two bus bars (FDC bus bars 425 and 426), serving as terminals for receiving electric power generated by the fuel cell apparatus 2, are arranged so as to be lined up in the left-right direction of the fuel cell vehicle 1. The FDC bus bars 425 and 426 are electrically connected to the FC bus bars 201 and 202, respectively, and the FDC bus bars 425 and 426 are arranged so as to horizontally protrude rearward from inside of the FDC container 400. The FDC bus bars 425 and 426 are arranged, when seen from above in a state where the DC-DC converter 4 is fastened and fixed to the fuel cell casing 200, at positions overlapping with the positions of the FC bus bars 201 and 202, respectively. The FDC bus bars 425 and 426 respectively have fastening bolt holes 427 and 428, each being formed at the tip thereof, close to the center.
A part of the FDC cover 402 extends rearward and covers a part of the FDC flange 403 from above. In the FDC cover 402, a through-hole 430 is formed at a position above the through-hole 420 formed in the FDC flange 403. The through-hole 430 is formed so as to enable the operation of fastening the FC bus bar 201 and the FDC bus bar 425 and the operation of fastening the FC bus bar 202 and the FDC bus bar 426 to be carried out from above. After the completion of such fastening operation, a protection cover 440 is attached so as to cover the through-hole 430. This protection cover 440 is for limiting access to the FC bus bar 202, etc., and is fastened and fixed to the FDC container 400 with bolts at both ends in the left-right direction thereof.
A part of the rearward end (the center part in the left-right direction) of the FDC flange 403 retracts in a direction opposite to the fuel cell casing 200 (forward direction), thereby forming a recessed part 450. To put it another way, the rearward end of the FDC flange 403 has an end surface 451 which is perpendicular to the front-back direction of the fuel cell vehicle 1, and corners 452 and 453 protruding rearward, respectively, from the left and right ends of the end surface 451.
The distance (spacing) between the corners 452 and 453 is substantially the same as the width in the left-right direction of the lower end of the vertical part 205b in the FC bus bar casing 205. In a state where the DC-DC converter 4 is fastened and fixed to the fuel cell casing 200, the recessed part 450 and the vertical part 205b are engaged with each other. In other words, the right side surface of the vertical part 205b faces the inner surface of the corner 452 in the left-right direction, while the left side surface of the vertical part 205b faces the inner surface of the corner 453 in the left-right direction.
Two FDC ribs 460 and 461 are formed below the FDC flange 403 and support the FDC flange 403 from below. The FDC rib 460 is formed in a plate shape, perpendicular to the left-right direction of the vehicle, with the upper part thereof being connected to the lower surface of the FDC flange 403 and the front side thereof being connected to the rearward side surface of the FDC casing 401. The thickness (width in the left-right direction) of the FDC rib 460 is slightly smaller than the width of the gap 212 formed in the fastening base 207. In a state where the DC-DC converter 4 is fastened and fixed to the fuel cell casing 200, the FDC rib 460 is inserted into the gap 212.
The FDC rib 461 is formed in a plate shape, perpendicular to the left-right direction of the vehicle, with the upper part thereof being connected to the lower surface of the FDC flange 403 and the front side thereof being connected to the rearward side surface of the FDC casing 401. The thickness (width in the left-right direction) of the FDC rib 461 is slightly smaller than the width of the gap 216 formed in the fastening base 208. In a state where the DC-DC converter 4 is fastened and fixed to the fuel cell casing 200, the FDC rib 461 is inserted into the gap 216.
Referring now to
The unit 490 is fastened and fixed to the FDC casing 401 at three locations—one at the rear side (bolt 491) and two at the front side (bolts 492 and 493). By arranging only one fastening location at the rear side, namely, at the side close to the FDC flange 403, the fastening locations for fixing the unit 490 can be arranged without making such locations close to the bolt through-hole 410a, etc., formed in the FDC flange 403.
Referring next to
The fuel cell casing 200 is first arranged and fixed to a predetermined position below the floor panel, before arranging the DC-DC converter 4. The fuel cell casing 200 is arranged with the FC seal surface 203 on the forward side thereof, and fastened and fixed to the vehicle body frame, etc., below the floor panel. Here, the position of the fuel cell casing 200 is such that one of the protection bars PL (not shown in
When the fuel cell casing 200 is fixed to the predetermined position, the DC-DC converter 4 is then arranged. The DC-DC converter 4 is arranged with the FDC flange 403 facing the fuel cell casing 200 (rearward), such that the FDC flange 403 covers from above the fastening bases 207 and 208 and FC seal surface 203.
Specifically, the recessed part 450 of the FDC flange 403 is engaged firstly with a portion of the vertical part 205b close to the upper end thereof. As already explained above, the length (width) of the vertical part 205b in the left-right direction gradually increases from the top down. Further, the distance (spacing) between the corner 452 and the corner 453 is made substantially the same as the width in the left-right direction of the lower end of the vertical part 205b in the FC bus bar casing 205. Thus, when the recessed part 450 is engaged with the portion of the vertical part 205b close to the upper end thereof, a certain looseness exists between the recessed part 450 and the vertical part 205b in the left-right direction. Such looseness enables the operation of engaging the recessed part 450 with the portion close to the upper end of the vertical part 205b (rough alignment in the left-right direction) to be performed with ease.
The corner 452 and the corner 453 have tapered parts 454 and 455, formed at their respective tips. As a result, the distance (spacing) between the corners 452 and 453 becomes larger toward the rear side. Accordingly, the recessed part 450 is guided by such tapered parts 454 and 455 so as to be engaged with the vertical part 205b, and this makes the operation of engaging the recessed part 450 with the portion close to the upper end of the vertical part 205b much easier.
Further, the tip of the corner 452 and the tip of the corner 453 have a rounded shape when seen from above. Thus, damage of the fuel cell casing 200 can be suppressed, even if the tip of the corner 452, etc., hits the fuel cell casing 200 by error during the operation of engaging the recessed part 450 with the portion close to the upper end of the vertical part 205b.
After that, while keeping the vertical part 205b and the recessed part 450 of the FDC flange 403 engaged with each other, the DC-DC converter 4 is gradually lowered so as to bring the FDC flange 403 close to the fastening bases 207 and 208. During this process, the shaft 211 is inserted through the shaft through-hole 411 and the shaft 215 is inserted through the shaft through-hole 415.
Although the cross-section of the shaft through-hole 411 is not shown in the drawing, the shaft through-hole 411 is formed in a similar manner to the shaft through-hole 415. That is, the inner surface of the shaft through-hole 411 is formed such that the inclination angle of the rearward side is moderate, relative to that of the forward side.
Since the shaft through-holes 411 and 415 are formed as described above, the shafts 211 and 215 are securely inserted through the respective shaft through-holes 411 and 415 during the process of bringing the FDC flange 403 close to the fastening bases 207 and 208.
The reason why the inner surface of the shaft through-holes 411 and 415 is formed such that the inclination angle of the rearward side is moderate, relative to that of the forward side, is as follows. During the process of lowering the DC-DC converter 4, the degree of freedom that allows the DC-DC converter 4 to be displaced rearward of the predetermined position is relatively small (since the end surface 451 of the FDC flange 403 hits the vertical part 205b). Thus, even if the forward side of the inner surface of the shaft through-holes 411 and 415 has a steep angle of inclination, the shafts 211 and 215 can be securely guided into the respective shaft through-holes 411 and 415 without missing such shaft through-holes.
On the other hand, the degree of freedom that allows the DC-DC converter 4 to be displaced forward of the predetermined position is relatively large. Thus, in this embodiment, by making the inclination angle of the forward side of the inner surface of the shaft through-holes 411 and 415 moderate, a larger amount of displacement can be allowed. As a result, the shafts 211 and 215 are securely guided into the respective shaft through-holes 411 and 415 without missing such shaft through-holes.
Referring back to
Further, the FDC rib 460 enters the gap 212 formed in the fastening base 207 and the FDC rib 461 enters the gap 216 formed in the fastening base 208. Thus, the DC-DC converter 4 is also guided to the predetermined position (the position fastened and fixed to the fuel cell casing 200) by the gaps 212 and 216.
The DC-DC converter 4 moves down while being guided by the shafts 211 and 215, the vertical part 205b, and the gaps 212 and 216 as described above, and is finally arranged in a state where the lower surface of the FDC flange 403 is in contact with the fastening surface 209 of the fastening base 207 and the fastening surface 213 of the fastening base 208. In this state, the positions of the bolt through-holes 410a, 410b and 410c formed in the FDC flange 403 correspond to the positions of the bolt insertion holes 210a, 210b and 210c formed in the fastening base 207, respectively, when seen from above. Similarly, the positions of the bolt through-holes 414a, 414b and 414c formed in the FDC flange 403 correspond to the positions of the bolt insertion holes 214a, 214b and 214c formed in the fastening base 208, respectively, when seen from above.
Further, the lower surface of the FDC bus bar 425 is in contact with the top surface of the FC bus bar 201, and the position of the fastening bolt hole 427 corresponds to the position of the fastening bolt hole 220, when seen from above. Similarly, the lower surface of the FDC bus bar 426 is in contact with the top surface of the FC bus bar 202, and the position of the fastening bolt hole 428 corresponds to the position of the fastening bolt hole 221, when seen from above. In this state, bolts BT3 and BT4 (not shown in the drawing) are inserted into the respective fastening bolt holes 427 and 428, and tightened. As a result, the FDC bus bar 425 and FC bus bar 201 are electrically connected to each other and the FDC bus bar 426 and the FC bus bar 202 are electrically connected to each other.
The configuration of the connection part between the FDC bus bar 425 and the FC bus bar 201 will now be described with reference to
As shown in
A bus bar supporting column 280 is provided below the second portion 201b. The bus bar supporting column 280 is a column having substantially the same shape as that of the second portion 201b when seen from above, and the lower end thereof is fixed to the fuel cell casing 200. The upper end of the bus bar supporting column 280 forms a horizontal surface, in which a vertically-extending fixation bolt hole 290 is formed. The fixation bolt hole 290, when seen from above, has substantially the same shape as that of the fastening bolt hole 220, and is formed at the same position as that of the fastening bolt hole 220. The inner circumference of the fixation bolt hole 290 is threaded to form an internal thread.
When the DC-DC converter 4 is moved down and arranged at a predetermined position for fastening and fixing it to the fuel cell casing 200, the lower surface of the FDC bus bar 425 comes into contact with the top surface of the FC bus bar 201, and the fastening bolt hole 427, the fastening bolt hole 220 and the fixation bolt hole 290 are all at the same position, when seen from above, as shown in
In the FDC bus bar 425, a curved part RS is formed at a portion forward of the portion that is in contact with the FC bus bar 201, the curved part RS protruding upward to create an arch in the cross-section shown in
Here, as shown in
By providing such anti-drop walls WL1 and WL2, a bolt BT3 is prevented from dropping down, by error, while performing the operation of tightening the bolt BT3. It should be noted that, at the portion forward of the fastening bolt hole 427, the anti-drop walls WL1 and WL2 have a larger spacing therebetween, and accordingly, the anti-drop walls WL1 and WL2 will not interfere when performing the operation of tightening the bolt BT3.
It should also be noted that the FC bus bar 201 has a thickness larger than that of the FDC bus bar 425, as shown in
As described above, in the fuel cell vehicle 1 according to this embodiment, the fastening bases 207 and 208, each being a part of the fuel cell casing 200, and the FDC flange 403, which is a part of the DC-DC converter 4, are fastened and fixed to each other, with one being vertically superimposed on the other, in a space above the protection bar PL. As a result, the fastening surface therebetween extends not vertically but horizontally. Accordingly, even in a space above the protection bar PL, where a sufficient height cannot be ensured, a large fastening surface can be formed, so that sufficient fastening strength can be ensured between the fuel cell casing 200 and the DC-DC converter 4. It should be noted that, although the fastening bases 207 and 208 are fastened to the FDC flange 403 in a space above the protection bar PL in this embodiment, they may alternatively be fastened in a space below the protection bar PL and this arrangement also brings about the same effect as above.
Further descriptions will be made with reference to
In the conventional configuration shown in
On the other hand, in the configuration of this embodiment shown in
Moreover, in the conventional configuration shown in
It should be noted that, as another embodiment, the fastening part F1 and the fastening part F2 may be configured to have an inclined fastening surface therebetween, as shown in
In the fuel cell vehicle 1 according to this embodiment, the vertical part 205b (raised part) of the FC bus bar casing 205 is provided near the fastening bases 207 and 208 of the fuel cell casing 200, so as to protrude toward the DC-DC converter 4. Further, the FDC flange 403 of the DC-DC converter 4 has the recessed part 405 that retracts in a direction opposite to the fuel cell casing 200. With this configuration, when fastening and fixing the DC-DC converter 4 to the fuel cell casing 200, the alignment between the DC-DC converter 4 and the fuel cell casing 200 can be performed by engaging the recessed part 450 of the FDC flange 403 with the vertical part 205b (raised part). In other words, the recessed part 450 is guided by the vertical part 205b (raised part), and accordingly, the operation of fastening and fixing the DC-DC converter 4 to the fuel cell casing 200, while aligning the same, can be easily performed.
The fastening bases 207 and 208 and the raised part may be formed as separate members, or they may be formed as a unit. For example, a (single) horizontal fastening flange having bolt insertion holes 210a, 210b, 210c, 214a, 214b and 214c formed therein may be formed in the fuel cell casing 200, such that the fastening flange has a raised part on the top surface thereof and the raised part is engaged with the recessed part 450 of the FDC flange 403.
The following are supplemental descriptions of the configuration of the fuel cell vehicle 1, with regard to the portions other than those already described above.
Accordingly, an inclined part INC is provided rearward of the FDC cover 402 in the fuel cell vehicle 1. The wire harness WH is delivered to the left side of the fuel cell vehicle 1 via the space above the inclined part INC and arranged to run forward through the left side of the DC-DC converter 4. By providing the inclined part INC rearward of the FDC cover 402 in this way, the space for routing the wire harness can be ensured.
Referring back to
If the bolts BT1 and BT2 are loosened with the DC-DC converter 4 being kept fastened and fixed to the fuel cell casing 200, the tips of the bolts BT1 and BT2 interfere with the respective tips of the plate-like projections 406 and 407, which means that this configuration can prevent the bolts BT1 and BT2 from being removed with the DC-DC converter 4 being kept fastened and fixed to the fuel cell casing 200.
As shown in
Although it may be possible to form the O-ring groove GR on the top seal surface, considering the possibility that water could be collected within the O-ring groove GR in that case, the O-ring groove GR is desirably formed on the lower surface of the FDC flange 403, as in this embodiment.
In the fuel cell vehicle 1, once the DC-DC converter 4 is fastened and fixed to the fuel cell casing 200, it is not possible to visually confirm, from the outside, that the O-ring RG is inserted into the O-ring groove GR. However, considering the possibility that a mistake of not inserting the O-ring RG could occur during the assembly operation, it is desirable that the existence of the O-ring RG can be visually confirmed from the outside even in the state of the DC-DC converter 4 being fastened and fixed.
As shown in
Alternatively, as shown in
As shown in
On the lower surface side of the FDC flange 403, a fastening space FSP for fastening the FC bus bar 201 with the FDC bus bar 425 and fastening the FC bus bar 202 with the FDC bus bar 426 is formed. The fastening space FSP is formed so that it includes the through-hole FH, when seen from above. Further, the lower end of the fastening space FSP is made open, i.e., an opening UH is formed, for receiving the FC bus bars 201 and 202. Furthermore, the fastening space FSP communicates, at the forward side thereof, with the interior of the FDC container 400, so as to receive the FDC bus bars 425 and 426 that protrude from inside the FDC container 400 rearward.
As shown in
Embodiments of the present invention have been described above, with reference to specific examples. However, the present invention is not limited to such specific examples. Design modifications to such specific examples, which will be made by a person skilled in the art as appropriate, are also included in the scope of the present invention, as long as they have the features of the present invention. For example, each element in each of the above-described specific examples and the arrangement, materials, conditions, shapes, dimensions, etc., of such element are not limited to those described above and may be modified as appropriate. In addition, each element in each of the above-described embodiments may be combined as long as such combination is technically possible and such combination is also included in the scope of the present invention as long as it has the features of the present invention.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2012/061379 | 4/27/2012 | WO | 00 | 3/26/2015 |
