JP2020131728A - Understructure of fuel cell vehicle - Google Patents

Abstract

To suppress interference of a high-voltage component with a drive unit and a hydrogen tank upon occurrence of rear-end collision.SOLUTION: A high-voltage component 70 is mounted between a first hydrogen tank 60 and a drive unit 80 under a rear floor panel 15. The rear floor panel 15 is provided with a first panel curve surface part 22 and a second floor tunnel 24. The first panel curve surface part 22 is a part of protrusion curve shape in side view extending in the vehicle width direction along a shape of the first hydrogen tank 60 above the first hydrogen tank 60. The second floor tunnel 24 is a part of Π shape in front view extended backward of a vehicle body from the first panel curve surface part 22. The front end of a ceiling part 24A of the second floor tunnel 24 is connected with an upper part of the first panel curve surface part 22. The high-voltage component 70 is suspended and supported by the ceiling part 24A of the second floor tunnel 24.SELECTED DRAWING: Figure 2

Description

The present invention relates to a substructure of a fuel cell vehicle on which a hydrogen tank is mounted.

Various parts are installed under the floor of the vehicle. For example, in the case of a rear-wheel drive vehicle, a drive unit such as a rotary electric machine or a transaxle is provided between the pair of rear wheels and under the luggage floor panel. In addition, electric vehicles and hybrid vehicles are equipped with batteries under the floor. In fuel cell vehicles, a hydrogen tank is installed under the floor.

A structure that protects these parts in the event of a vehicle collision has been conventionally known. For example, in Patent Document 1, when a side collision occurs, the floor cross member bends downward, so that the battery under the floor cross member is released downward and interference between other parts and the battery is suppressed. Further, in Patent Document 2, in a structure in which a battery is suspended from a frame extending in the vehicle width direction, the battery pack is moved forward by breaking so that the frame bends forward in the event of a rear collision, and the battery is moved from the rear. The collision load input to the pack is reduced.

JP-A-2017-144825 JP-A-2017-114190

By the way, in the case of a fuel cell vehicle, a hydrogen tank is provided as described above. For example, under the rear seat, the hydrogen tank is arranged so that the longitudinal direction faces the vehicle width direction (that is, horizontally). When the fuel cell vehicle is a rear-wheel drive vehicle, the drive unit is arranged under the luggage floor panel as described above.

In addition, high voltage components may be placed between the hydrogen tank and the drive unit. This high voltage component includes, for example, a high voltage cable or a junction block for applying a high voltage to the rotating electric machine of the drive unit.

Here, the drive unit is provided with a highly rigid case for reducing vibration and noise of, for example, a rotating electric machine or a transaxle which is a drive source. Further, the hydrogen tank has a load-bearing performance at a level at which hydrogen leakage does not occur even if the vehicle is collided and destroyed, for example.

When such a layout is adopted in which high-voltage parts are arranged so as to be sandwiched between the high-rigidity drive unit and the hydrogen tank in the front-rear direction of the vehicle, a vehicle rear surface collision (hereinafter, appropriately referred to as a rear collision). Sometimes it is necessary to suppress the interference between the high voltage component and the drive unit and the hydrogen tank.

The present invention relates to a substructure of a fuel cell vehicle. The substructure includes a load-bearing hydrogen tank, a drive unit, and high voltage components. The hydrogen tank is arranged under the floor panel so as to face the longitudinal direction in the vehicle width direction. The drive unit is provided under the floor panel and behind the vehicle body from the hydrogen tank. The high voltage component is located under the floor panel and between the hydrogen tank and the drive unit. The floor panel includes a panel curved surface portion and a floor tunnel. The curved surface portion of the panel is a convex side view portion extending above the hydrogen tank in the vehicle width direction along the shape of the hydrogen tank. The floor tunnel is a front view Π-shaped part extending from the curved surface of the panel to the rear of the vehicle body. The front end of the ceiling portion of the floor tunnel is connected to the upper portion of the curved surface portion of the panel. Further, high voltage parts are suspended and supported on the ceiling of the floor tunnel.

According to the above configuration, a compressive load is input to the floor panel at the time of rear collision. Along with this load input, the convex shape of the curved surface portion of the panel is crushed and the upper portion thereof is lifted. By lifting the upper portion of the curved surface portion of the panel, the ceiling portion of the floor tunnel connected to the upper portion is also lifted. Along with this, high-voltage parts suspended and supported on the ceiling of the floor tunnel are also lifted. As a result, the high-voltage component can be released upward with respect to the hydrogen tank and the drive unit.

According to the present invention, it is possible to suppress the interference between the high voltage component and the drive unit and the hydrogen tank at the time of a rear collision.

It is a perspective view which illustrates the floor structure of the fuel cell vehicle which concerns on this embodiment. FIG. 1A is a cross-sectional view taken along the line AA of FIG. 1, which is a side sectional view illustrating the lower structure of the fuel cell vehicle according to the present embodiment. It is a perspective view explaining the load input at the time of a rear collision. It is a side sectional view explaining the deformation of the floor panel at the time of a rear collision.

FIG. 1 illustrates a perspective view of a floor structure as a lower structure of the fuel cell vehicle according to the present embodiment. Further, FIG. 2 exemplifies the floor and the structure under the floor in the cross-sectional view taken along the line AA of FIG. 1 as the lower structure.

In FIGS. 1 to 4, the front-rear direction of the vehicle body is indicated by the axis represented by the symbol FR, the vehicle width direction is indicated by the axis represented by the symbol RW, and the vertical direction of the vehicle body is indicated by the symbol UP. Indicated by. The front and rear axle FR of the vehicle body has the front direction of the vehicle body as the positive direction. The vehicle width axis RW has the right width direction as the positive direction. Further, the vertical axis UP of the vehicle body has the upward direction as the positive direction. These three axes are orthogonal to each other.

In addition, hereinafter, the front direction and the rear direction of the vehicle body are simply described as front and rear as appropriate. Similarly, the vehicle body upward direction and the vehicle body downward direction are simply described as upward and downward.

With reference to FIGS. 1 and 2, the substructure of the fuel cell vehicle according to the present embodiment includes a floor panel (including a front floor panel 10 and a rear floor panel 15), a first hydrogen tank 60, a drive unit 80, and a height. It includes a voltage component 70.

With reference to FIG. 1, the floor panel includes a front floor panel 10 and a rear floor panel 15. These panel materials are composed of metal panels such as aluminum plates.

The front floor panel 10 constitutes the floor plate of the passenger compartment (in other words, the cabin). A first floor tunnel 12 is formed at the center of the front floor panel 10 in the vehicle width direction. The first floor tunnel 12 is formed so as to project upward from the floor surface (in other words, the reference surface) of the front floor panel 10, and is a Π-shaped square tunnel portion when viewed from the front. That is, the first floor tunnel 12 includes a ceiling portion 12A and a pair of side surface portions 12B extending downward from both ends in the vehicle width direction.

Further, a ridge line 12C is extended in the front-rear direction of the vehicle as a boundary line between the ceiling portion 12A and the side surface portion 12B. For example, at the time of a frontal collision of a vehicle, the ridge line 12C is mainly subjected to a load, so that a decrease in the vehicle interior space is suppressed. For example, a reinforcing material also called a tunnel lean force may be superposed on the first floor tunnel 12.

A rear floor panel 15 is provided behind the first floor tunnel 12 with the center floor cloth 42 interposed therebetween. The rear floor panel 15 includes a rear floor portion 20 and a luggage floor portion 30 in this order from the front.

The rear floor portion 20 refers to, for example, the area between the center floor cloth 42 and the first rear cloth 44, and includes a lower portion of the rear seat. Further, the rear floor portion 20 is arranged so as to sink downward with respect to both crosses. The luggage floor portion 30 points to a region rearward from the first rear cloth 44, and constitutes a floor plate portion of the luggage space.

A first panel curved surface portion 22 and a second floor tunnel 24 are formed on the rear floor portion 20. With reference to FIG. 2, the first panel curved surface portion 22 is formed along the shape of the first hydrogen tank 60 arranged below the curved surface portion 22.

The first hydrogen tank 60 is arranged so that its longitudinal direction (that is, the tank axial direction) is directed in the vehicle width direction. The primary hydrogen tank 60 has a so-called cocoon ball shape, and includes a cylindrical portion extending in the axial direction of the tank and hemispherical portions provided at both ends thereof.

The first panel curved surface portion 22 is formed above the first hydrogen tank 60 arranged in this way along the shape of the first hydrogen tank 60. For example, as illustrated in FIG. 1, the curved surface portion 22 of the first panel has a shape that resembles an upper portion of a cocoon ball shape, extends in the vehicle width direction, and has a convex shape in a side view. It is formed so as to be.

Further, for example, the curved surface portion 22 of the first panel is formed with a large diameter portion 22A that rises upward as compared with other portions at the center in the vehicle width direction. The outer portion of the large diameter portion 22A in the vehicle width direction is referred to as the small diameter portion 22C. That is, the first panel curved surface portion 22 is formed with a large diameter portion 22A having a relatively large radius of a convex curved surface (that is, an arch) and a small diameter portion 22C having a relatively small radius. Further, the large diameter portion 22A is formed in the central portion of the curved surface portion 22 of the first panel in the vehicle width direction, and the small diameter portions 22C are formed on both sides in the vehicle width direction.

For example, the step between the large diameter portion 22A and the small diameter portion 22C of the first panel curved surface portion 22 forms a side view convex curved ridge line 22B extending in the vehicle front-rear direction on the first panel curved surface portion 22. The ridge line 22B may be provided, for example, on an extension line of the ridge line 12C of the first floor tunnel 12. With such a configuration, the load is smoothly transmitted from the first floor tunnel 12.

Further, the second floor tunnel 24 is extended to the rear of the vehicle body from the curved surface portion 22 of the first panel. The second floor tunnel 24 is a Π-shaped square tunnel when viewed from the front in the same manner as the first floor tunnel 12, for example. That is, the second floor tunnel 24 includes a ceiling portion 24A and side surface portions 24B connected to both ends of the ceiling portion 24A in the vehicle width direction and extended downward.

A ridge line 24C extends in the front-rear direction of the vehicle body as a boundary line between the ceiling portion 24A and the side surface portion 24B. The ridge line 24C may be connected to the ridge line 22B of the curved surface portion 22 of the first panel. By doing so, for example, when a compressive load in the front-rear direction of the vehicle body that is sandwiched between the center floor cross 42 and the first rear cross 44 is input, these ridge lines 22B and 24C mainly receive the load. ..

Further, as will be described later, when the input compressive load exceeds the upper limit of the load capacity of the curved surface portion 22 of the first panel, the curved surface shapes of the large diameter portion 22A and the small diameter portion 22C are crushed, and the upper portion thereof is lifted above the vehicle body. ..

The front end of the ceiling portion 24A of the second floor tunnel 24 is connected to the upper portion of the curved surface portion 22 of the first panel. For example, referring to FIG. 2, the front end of the ceiling portion 24A of the second floor tunnel 24 is connected to the vicinity of the apex of the large diameter portion 22A. With such a structure, for example, the large diameter portion 22A has a smaller arc opening angle than the small diameter portion 22C.

By connecting the ceiling portion 24A of the second floor tunnel 24 to the upper portion of the first panel curved surface portion 22, when the curved surface shape of the first panel curved surface portion 22 is crushed by the input of the compressive load as described above, The ceiling portion 24A of the second floor tunnel 24 is also lifted above the vehicle body in accordance with the lifting of the upper portion of the curved surface portion 22 of the first panel.

A luggage floor portion 30 is provided behind the rear floor portion 20 with the first rear cloth 44 interposed therebetween. A second panel curved surface portion 32 (see FIG. 1) is formed on the luggage floor portion 30.

The second panel curved surface portion 32 is formed along the shape of a secondary hydrogen tank (not shown) arranged below the curved surface portion 32. For example, like the first hydrogen tank 60, the second hydrogen tank is arranged so that its longitudinal direction (that is, the tank axial direction) is directed in the vehicle width direction. The curved surface portion 32 of the second panel extends in the vehicle width direction along the shape of the secondary hydrogen tank arranged in this way, and is formed so as to be convex in the side view.

The skeleton members are arranged around each member of the floor panel described above. For example, rockers 40 are extended in the front-rear direction of the vehicle body at both ends of the front floor panel 10 in the vehicle width direction. A rear side member 48 is connected to the rear end of the rocker 40 and extends to the rear end of the vehicle body.

Further, referring to FIGS. 1 and 2, a center floor cloth 42 is provided between the front floor panel 10 and the rear floor panel 15. The center floor cloth 42 extends in the vehicle width direction and both ends thereof are connected to the rocker 40.

Further, a first rear cloth 44 is provided between the rear floor portion 20 and the luggage floor portion 30 of the rear floor panel 15. A second rear cloth 46 is provided in front of the curved surface portion 32 of the second panel. Both the first rear cross 44 and the second rear cross 46 extend in the vehicle width direction, and both ends thereof are connected to the rear side member 48.

FIG. 2 is a cross section taken along the line AA of FIG. 1 and illustrates the structure under the floor panel. Under the rear floor panel 15, a first hydrogen tank 60, a high voltage component 70, a rear suspension member 84, and a drive unit 80 are provided.

The first hydrogen tank 60 is arranged below the curved surface portion 22 of the first panel. As described above, the first hydrogen tank 60 is arranged sideways so that its longitudinal direction (that is, the tank axial direction) faces the vehicle width direction.

The first hydrogen tank 60 and the second hydrogen tank (not shown) are so-called high-pressure tanks and have sufficient pressure resistance. These tanks consist of a plastic liner layer that contains hydrogen, a CFRP plastic layer that is wound with carbon fiber reinforced plastic (CFRP), and a GFRP that is wound with glass fiber reinforced plastic (GFRP) for surface protection. Consists of a plastic layer.

Further, the first hydrogen tank 60 and the second hydrogen tank (not shown) have load bearing performance. For example, these tanks have a load-bearing capacity that can withstand a load of about 15 times the input load at the time of a vehicle collision test. By providing such load-bearing performance, hydrogen leakage from the first hydrogen tank 60 and the second hydrogen tank can be prevented even in the unlikely event that the vehicle is collided and destroyed.

As described above, the first hydrogen tank 60 has a so-called cocoon ball shape, and includes a cylindrical portion extending in the tank axial direction and a hemispherical portion arranged at both ends thereof. The periphery of the first hydrogen tank 60 is supported by fastening bands 61 and 62, and the front ends of the fastening bands 61 and 62 are fastened to the front floor panel 10 via the fastening member 65. The rear ends of the fastening bands 61 and 62 are fastened to the rear floor portion 20 via the tank bracket 63, the fastening members 66 and 67, and the support bracket 64.

The drive unit 80 is provided behind the first hydrogen tank 60 and the high voltage component 70. The drive unit 80 is provided for driving the rear wheels, and the shaft 82 connected to the rear tire 50 is inserted in the vehicle width direction.

The drive unit 80 includes a rotary electric machine for driving the rear tire 50 and a transaxle that transmits the drive of the rotary electric machine to the shaft 82. The casing of the drive unit 80 has high rigidity (in other words, wall thickness) in order to reduce noise caused by driving a rotary electric machine or a transaxle.

The drive unit 80 is supported, for example, by a rear suspension member 84 that supports the suspension mechanism of the rear tire 50. The rear suspension member 84 is supported by the rear side member 48. That is, the drive unit 80 is supported by the rear side member 48 via the rear suspension member 84.

The high voltage component 70 is provided with an electric device for applying a high voltage to the rotating electric machine of the drive unit 80. For example, the high voltage component 70 includes a high voltage cable and a junction block.

In the fuel cell vehicle, a high voltage circuit is provided from the fuel cell stack (not shown) to the rotary electric machine of the drive unit 80. For example, electric power is supplied from the fuel cell stack to the rotary electric machine via a DC / DC converter and an inverter. Further, the high voltage circuit is also provided with a junction block that interrupts the circuit. In addition, these devices are connected by a high voltage cable. The high-voltage component 70 may be any of these circuit components, and in short, a component that needs to prevent the conductor from being exposed due to an impact at the time of a rear collision corresponds to the high-voltage component 70.

The high voltage component 70 is provided between the first hydrogen tank 60 and the drive unit 80 along the vehicle body front-rear direction. For example, the first hydrogen tank 60, the high voltage component 70, and the drive unit 80 are arranged so that their positions in the vehicle height direction overlap (in other words, coincide with each other) at least in a part thereof.

Further, the high voltage component 70 is suspended and supported by the ceiling portion 24A of the second floor tunnel 24 of the rear floor portion 20. For example, the high voltage component 70 is suspended and supported on the lower surface of the ceiling portion 24A via the insulating bracket 72.

As will be described later, at the time of the rear collision of the vehicle, the second floor tunnel 24 is lifted above the vehicle body, and the high voltage component 70 supported by the second floor tunnel 24 is also lifted. As a result, the high-voltage component 70 can escape upward with respect to the first hydrogen tank 60 and the drive unit 80, and interference between the first hydrogen tank 60 and the drive unit 80 and the high-voltage component 70 can be suppressed.

<State at the time of a rear collision>
3 and 4 show an example of a vehicle at the time of a rear collision. When an obstacle collides with the rear surface of the vehicle, for example, when a rear vehicle collides, the collision load is transmitted from the rear of the vehicle. That is, the rear part of the vehicle is deformed so that the rear part of the vehicle crushes the front part.

With reference to FIG. 4, the drive unit 80 is pushed by a secondary hydrogen tank (not shown) behind it and displaced forward of the vehicle body. Accordingly, the front portion of the drive unit 80 is also displaced to the front of the vehicle body. For example, the tank bracket 63 in front of the drive unit 80 is pushed by the drive unit 80 and deformed into an S shape. Further, the support bracket 64 fastened to the tank bracket 63 and the rear floor portion 20 fixed to the support bracket 64 are also displaced to the front of the vehicle body while being deformed.

At this time, referring to FIG. 3, the load in the vehicle body front direction input to the rear floor portion 20 is mainly input to the ridge lines 22B and 24C of the first panel curved surface portion 22 and the second floor tunnel 24. This load is transmitted to the center floor cloth 42 and the first floor tunnel 12 in front of the center floor cloth 42. The first floor tunnel 12 including the center floor cloth 42, which is a skeleton member, and the ridge line 12C extending in the front-rear direction of the vehicle body, stretches against this input load. As a result, the curved surfaces 22 of the first panel and the ridges 22B and 24C of the second floor tunnel 24 receive loads from the front and rear of the vehicle body. That is, the ridge lines 22B and 24C receive a compressive load.

When the compressive load received by the ridges 22B and 24C exceeds the upper limit of the load capacity, the curved surface portion 22 of the first panel and the second floor tunnel 24 buckle and deform. Here, when comparing the two, the convex (that is, arch) -shaped first panel curved surface portion 22 is ahead of the second floor tunnel 24 having the ridge line 24C extending linearly with respect to the input load. Surrender to. Specifically, as illustrated in FIG. 4, the curved surfaces of the large-diameter portion 22A and the small-diameter portion 22C of the first panel curved surface portion 22 are crushed with respect to the compressive load input in the front-rear direction of the vehicle body. It can be transformed.

Along with the crushing deformation of the curved surface, the upper portions of the large diameter portion 22A and the small diameter portion 22C of the first panel curved surface portion 22 are lifted above the vehicle body. Here, as described above, the ceiling portion 24A of the second floor tunnel 24 is connected to the upper portion of the large diameter portion 22A. Therefore, as the large diameter portion 22A is lifted, the ceiling portion 24A of the second floor tunnel 24 is also lifted.

Further, as described above, the high voltage component 70 is suspended and supported on the ceiling portion 24A. Therefore, as the ceiling portion 24A is lifted, the high voltage component 70 is also lifted above the vehicle body. By lifting the high voltage component 70 in this way, the high voltage component 70 can be released to the upper part of the vehicle body with respect to the first hydrogen tank 60 and the drive unit 80.

As illustrated in FIG. 4, the distance between the drive unit 80 and the first hydrogen tank 60 is narrowed at the time of rear collision, but the high voltage component 70 arranged between them moves upward (that is, escapes). Therefore, the interference between the first hydrogen tank 60 and the drive unit 80 and the high voltage component 70 is suppressed.

10 Front floor panel, 12 1st floor tunnel, 12C 1st floor tunnel ridgeline, 15 Rear floor panel, 20 Rear floor part, 22 1st panel curved surface part, 22A large diameter part, 22B 1st panel curved surface part ridgeline, 22C small diameter Part, 24 2nd floor tunnel, 24A 2nd floor tunnel ceiling, 24B 2nd floor tunnel side, 24C 2nd floor tunnel ridge, 30 luggage floor, 60 1st hydrogen tank, 70 high voltage parts, 72 insulation bracket, 80 drive unit, 84 rear suspension member.

Claims (1)

Under the floor panel, a load-bearing hydrogen tank that is arranged so that the longitudinal direction faces the vehicle width direction,
A drive unit under the floor panel and provided behind the vehicle body from the hydrogen tank.
Under the floor panel, high-voltage components provided between the hydrogen tank and the drive unit, and
It is a substructure of a fuel cell vehicle equipped with
The floor panel
Above the hydrogen tank, a curved panel portion having a convex side view extending in the vehicle width direction along the shape of the hydrogen tank,
A front view Π-shaped floor tunnel extending from the curved surface of the panel to the rear of the vehicle body,
With
The front end of the ceiling portion of the floor tunnel is connected to the upper portion of the panel curved surface portion.
The high-voltage component is suspended and supported on the ceiling of the floor tunnel.
Substructure of fuel cell vehicle.

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