Electric vehicle

Abstract

In this electric vehicle, an electric unit accommodating an electric motor, an inverter, and a gear box in a housing is disposed in a motor room provided in a front part of a vehicle body. The motor room includes a pair of side members and a suspension member attached to the vehicle body below the side members. The suspension member has a grid-like shape including a pair of longitudinal members and a front lateral member and a rear lateral member that connect the longitudinal members to each other. The longitudinal members have a cross-sectional area as viewed from the vehicle body front side that, at least in a range from the end portion on the vehicle body front side to a connection portion connecting with the rear lateral member, decreases toward the vehicle body rear side. The electric unit is disposed, in a top view, within a region surrounded by the pair of longitudinal members and the front and rear lateral members, and has a vehicle body front side portion that is fixed to the suspension member and a vehicle body rear side portion that is fixed to the pair of side members in the vehicle body lateral direction.

Description

Electric vehicle

[0001] The present invention relates to an electric vehicle.

[0002] There is known a collision countermeasure for absorbing a collision load when a vehicle causes a frontal collision by deforming a portion in front of the passenger space of the vehicle body and suppressing the propagation of the collision load to the passenger space. In the case of an electric vehicle, the rigidity of the housing that houses the electric motor is often higher than that of the constituent members of the vehicle body. Therefore, there is a problem that the amount of deformation of the vehicle body is restricted by the housing and the collision load cannot be sufficiently absorbed.

[0003] JP2004-161260A discloses a structure for solving this problem. Specifically, while the drive motor unit is attached to a suspension member disposed at the lower part of the motor room via a front motor mount and a rear motor mount, an air compressor is disposed obliquely upward in front of the drive motor unit, above and in front of the front motor mount. According to this configuration, when a frontal collision occurs, a collision load is input to the air compressor, this collision load is transmitted to the drive motor of the drive motor unit, and further transmitted to the front motor mount and the rear motor mount. Then, the rear motor mount buckles first, and the drive motor unit drops while rotating around the front motor mount. As a result, the amount of deformation of the vehicle body is no longer restricted by the drive motor unit.

[0004] However, the configuration of the above document is premised on the fact that the air compressor is disposed obliquely upward in front of the drive motor unit, above and in front of the front motor mount. If the air compressor is not in that position, the desired effect cannot be obtained. And, for example, in a vehicle with a narrow motor room or a vehicle that uses a large air compressor because the passenger space is wide, there may be a case where the air compressor cannot be disposed at the same position as the configuration of the above document.

[0005] Therefore, an object of the present invention is to provide an electric vehicle having a configuration capable of absorbing a collision load during a frontal collision regardless of the arrangement position of the air compressor.

[0006] According to one aspect of the present invention, an electric vehicle is provided in which an electric unit, comprising an electric motor, an inverter, and a gearbox housed in a housing, is arranged in a motor room located at the front of the vehicle body. The electric vehicle includes in the motor room a pair of side members arranged along the longitudinal direction of the vehicle body, and a suspension member attached to the vehicle body below the side members. The suspension member has a grid shape comprising a pair of longitudinal members extending along the longitudinal direction of the vehicle body, and a front transverse member and a rear transverse member extending in the left-right direction of the vehicle body and connecting the longitudinal members. The longitudinal members have a cross-sectional area that decreases towards the rear of the vehicle body when viewed from the front, at least from the front end of the vehicle body to the connection with the rear transverse member. The electric unit is arranged in an area enclosed by the pair of longitudinal members and the pair of transverse members when viewed from above, and the front part of the vehicle body is fixed to the suspension member, while the rear part of the vehicle body is fixed to the pair of side members from the left-right direction of the vehicle body.

[0007] Figure 1 is a top view showing the mounting structure of the electric unit in the motor room. Figure 2 is a side view showing the mounting structure of the electric unit in the motor room. Figure 3 is a top view of the suspension member. Figure 4 is a side view showing the relationship between the electric unit and the dash panel. Figure 5 is a side view showing the deformation caused by a frontal collision.

[0008] Embodiments of the present invention will be described below with reference to the drawings.

[0009] Figure 1 is a top view showing the mounting structure of the electric unit 2 within the motor room 1 of the electric vehicle according to this embodiment. Figure 2 is a side view showing the mounting structure of the electric unit 2.

[0010] The electric unit 2 comprises an electric motor 3, an inverter (not shown), a gearbox 4, and a housing 12 that houses these components. The inverter is located, for example, on the top surface of the electric motor 3. In the following description, the electric motor 3 may also refer to the inverter as part of the electric motor 3.

[0011] The gearbox 4 is a three-axis type, for example, in which the input shaft, intermediate shaft, and output shaft (none of which are shown) are arranged in parallel, and the input shaft is arranged coaxially with the rotation shaft (not shown) of the electric motor 3.

[0012] The housing 12 comprises a main body 12A that houses the electric motor 3 and the input shaft of the gearbox 4, and a protruding portion 12B that houses the output shaft of the gearbox 4. The protruding portion 12B protrudes from the main body 12A in a direction perpendicular to the axial direction of the input shaft of the gearbox 4.

[0013] Furthermore, the motor room 1 includes a pair of side members 5 arranged along the longitudinal direction of the vehicle body, and a suspension member 6 attached to the vehicle body below the side members 5. When it is necessary to distinguish between the pair of side members 5, the left one is called the left side member 5L, and the right one is called the right side member 5R.

[0014] Here, the suspension member 6 will be described with reference to Figures 2 and 3. Figure 3 is a top view of the suspension member 6.

[0015] The suspension member 6 has a grid-like shape comprising a pair of longitudinal members 7 extending along the longitudinal direction of the vehicle body, and a front lateral member 8F and a rear lateral member 8R extending in the left-right direction of the vehicle body and connecting the longitudinal members 7. In this embodiment, the suspension member 6 also includes a front member 9 that connects the front ends of the pair of longitudinal members 7, but this is not an essential configuration. Furthermore, if it is necessary to distinguish between the pair of longitudinal members 7, the left one is called the left longitudinal member 7L, and the right one is called the right longitudinal member 7R.

[0016] The cross-sectional area of ​​the longitudinal member 7, at least from the end on the front side of the vehicle body to the connection point with the rear transverse member 8R, decreases as it approaches the rear of the vehicle body when viewed from the front.

[0017] Returning to the explanation of Figures 1 and 2.

[0018] The electric unit 2 is positioned such that the protruding portion 12B protrudes forward of the vehicle body within the area enclosed by a pair of vertical members 7 and a pair of horizontal members 8 when viewed from above. The front mount 10 is positioned on the protruding portion 12B, and the pair of rear mounts 11 are positioned on the main body portion 12A.

[0019] The protruding portion 12B is fixed to the front lateral member 8F of the suspension member 6 via the front mount 10. In this embodiment, there are two front mounts 10 as shown in Figure 1, but this is not the only option. The number of front mounts 10 is determined based on various considerations, such as drivability, noise and vibration performance, and rigidity during collisions. When viewed from the left-right direction of the vehicle body, the lateral member 8 is inclined such that its upper end is on the front side of the vehicle body and its lower end is on the rear side of the vehicle body, and the mount 10 supports the electric unit 2 from the front of the vehicle body.

[0020] The main body 12A is fixed to a pair of side members 5 from the left-right direction of the vehicle body via a pair of rear mounts 11. In this embodiment, the pair of rear mounts 11 are the left rear mount 11L and the right rear mount 11R, which are arranged opposite each other in the left-right direction of the vehicle body. In a top view, the portion of the main body 12A closer to the rear of the vehicle body is fixed by the left rear mount 11L and the right rear mount 11R. The front mount 10 has lower mounting rigidity than the rear mounts 11. This is so that even if the front mount 10 is released in the event of a frontal collision, the rear mount 11 remains fixed.

[0021] Furthermore, the front lateral member 8F is positioned in a vertical position that overlaps with the electric unit 2 when viewed from the front of the vehicle body.

[0022] Next, the relationship between the electric unit 2 and the dashboard panel 20 will be explained with reference to Figure 4.

[0023] Figure 4 is a side view showing the relationship between the electric unit 2 and the dashboard panel 20. Note that the side member 5 is omitted in Figure 4.

[0024] The dash panel 20 is a component that separates the passenger compartment from the motor room 1, located at the rear end of the motor room 1 in the longitudinal direction of the vehicle body. The dash panel 20 has a vertical wall portion 20A that extends in the vertical direction of the vehicle body, and an inclined portion 20B that slopes toward the rear of the vehicle body from the lower end of the vertical wall portion 20A. When the boundary between the vertical wall portion 20A and the inclined portion 20B is defined as the inflection point IP, the inflection point IP is located above the rear mount 11 in the vertical direction of the vehicle body.

[0025] The case of an electric vehicle with the above configuration being involved in a frontal collision will be explained with reference to Figures 4 and 5. Figure 5 is a side view showing the deformed state after a frontal collision.

[0026] In electric vehicles, it is desirable that the motor room 1 absorbs the impact load applied in the event of a frontal collision by deforming, thereby suppressing deformation of the passenger compartment. Generally, the housing 12 of the electric unit 2 has a higher rigidity than vehicle body structural members such as the side members 5 and suspension members 6 because it incorporates a core made of laminated electromagnetic steel sheets and a gear mechanism. Therefore, the presence of the electric unit 2 may limit the amount of deformation of the motor room 1, potentially preventing it from adequately absorbing the impact load. However, with the configuration of this embodiment, the above problem does not occur. The reasons for this will be explained in detail below.

[0027] The longitudinal member 7, from the front of the vehicle body to the connection point with the rear lateral member 8R, has a cross-sectional area that decreases as it approaches the rear of the vehicle body when viewed from the front. Therefore, when a collision load is applied, the longitudinal member 7 is prone to buckling near the front end of the connection point with the rear lateral member 8R (BP in the figure). The electric unit 2 is fixed at the front to the front lateral member 8F of the suspension member 6, and at the rear to the side member 5, which is located above the suspension member 6 in the vertical direction of the vehicle body. In other words, the rear mount 11 is located higher than the front mount 10. Generally, the side member 5 is configured to absorb the collision load by bending at the front of the vehicle body, so the area where the rear mount 11 is located is less prone to deformation. Therefore, when the longitudinal member 7 buckles, the electric unit 2 rotates counterclockwise in the figure (in the direction of the thick arrow in the figure) and tilts forward, pivoting on the pair of rear mounts 11, due to the rearward load input via the front mount 10. As a result, the length of the space occupied by the electric unit 2 in the longitudinal direction of the vehicle body is shortened, thus ensuring sufficient deformation of the motor room 1. In other words, even in a configuration where auxiliary equipment such as an air compressor is not placed diagonally above and in front of the electric unit 2, sufficient deformation of the motor room 1 can be ensured when a collision load is applied.

[0028] Furthermore, while a radiator for coolant is generally located at the front of the motor room 1, in the configuration of this embodiment, the radiator, which is pushed towards the rear of the vehicle body during a frontal collision, makes surface contact with the front lateral member 8F, thus avoiding the input of a localized load to the front lateral member 8F. This suppresses the fracture of the front mount 10. And because the front mount 10 does not fracture, the electric unit 2 can be tilted forward as described above.

[0029] Furthermore, since the pair of rear mounts 11 are positioned opposite each other in the left-right direction of the vehicle body, they not only serve as a pivot point when the electric unit 2 tilts forward as described above, but can also suppress yaw movement when a collision load is applied to the electric unit 2. This allows the electric unit 2 to tilt forward stably. Moreover, the electric unit 2 is mounted in a position where the protruding portion 12B is on the front side of the vehicle body and the main body portion 12A is on the rear side of the vehicle body. Therefore, even if the electric unit 2 and the dash panel 20 interfere with each other, the rear side of the main body portion 12A and the dash panel 20 will come into contact surface-to-surface contact, allowing the electric unit 2 to tilt forward stably.

[0030] Furthermore, since the mounting rigidity of the front mount 10 is lower than that of the rear mount 11, the front mount 10 is the first to break. And, if the electric unit 2 is supported only by the rear mount 11, it is more likely to rotate counterclockwise as described above.

[0031] If the deformation progresses further from the state shown in Figure 5 and the electric unit 2 is pushed towards the rear of the vehicle body, and the vertical wall portion 20A of the dash panel 20 extends to the lower end of the vehicle body, it will cause deformation of the vertical wall portion 20A. However, in this embodiment, an inclined portion 20B is provided, and the inflection point IP of the vertical wall portion 20A and the inclined portion 20B is located higher than the rear mount 11. Therefore, even if the rear mount 11 breaks and the electric unit 2 is pushed towards the rear of the vehicle body, the electric unit 2 will rotate counterclockwise in the figure with the inflection point IP as the pivot point, thereby suppressing deformation of the dash panel 20.

[0032] Furthermore, since the front lateral member 8F is positioned vertically to overlap with the electric unit 2 when viewed from the front of the vehicle, if the front mount 10 were to break, the front lateral member 8F would interfere with the protruding portion 12B. Therefore, the electric unit 2 can be rotated counterclockwise in the same way as when the front mount 10 is not broken.

[0033] As described above, this embodiment provides an electric vehicle in which an electric unit 2, in which an electric motor 3, an inverter, and a gearbox 4 are housed in a housing 12, is arranged in a motor room 1 located at the front of the vehicle body. This electric vehicle includes in the motor room 1 a pair of side members 5 arranged along the longitudinal direction of the vehicle body, and a suspension member 6 attached to the vehicle body below the side members 5. The suspension member 6 has a grid shape comprising a pair of longitudinal members 7 extending along the longitudinal direction of the vehicle body, and a front lateral member 8F and a rear lateral member 8R extending in the left-right direction of the vehicle body and connecting the longitudinal members 7 to each other. The pair of longitudinal members 7 have a cross-sectional area that, when viewed from the front of the vehicle body, decreases towards the rear of the vehicle body, at least in the range from the front end of the vehicle body to the connection with the rear lateral member 8R. The electric unit 2 is positioned within an area enclosed by a pair of vertical members 7 and a pair of horizontal members 8 when viewed from above, with its front portion fixed to the suspension member 6 and its rear portion fixed to a pair of side members 5 from the left and right sides of the vehicle. As a result, in the event of a frontal collision, the electric unit 2 rotates around the fixing points to the side members 5 as pivots, resulting in an inverted position, thereby ensuring sufficient deformation of the motor room 1 for impact absorption.

[0034] In this embodiment, the front portion of the electric unit 2 is fixed to the front lateral member (front lateral member) 8F of the suspension member 6 via one or more front mounts 10. Since the suspension member 6 is located lower than the side member 5, the front mounts 10 are positioned lower than the rear mounts 11. This makes it easier for the electric unit 2 to rotate as described above.

[0035] In this embodiment, the dash panel 20 located at the rear end of the motor room 1 in the longitudinal direction of the vehicle body has a vertical wall portion 20A extending in the vertical direction of the vehicle body and an inclined portion 20B connected to the lower end of the vertical wall portion 20A and inclined toward the rear of the vehicle body, and the boundary (inflection point IP) between the vertical wall portion 20A and the inclined portion 20B is located above the fixing point (rear mount 11) of the electric unit 2 to the side member 5 in the vertical direction of the vehicle body. As a result, even if the electric unit 2 is pushed in until it interferes with the dash panel 20, the electric unit 2 will rotate with the inflection point IP as the pivot point, thereby suppressing deformation of the dash panel 20.

[0036] In this embodiment, the rear portion of the electric unit 2 is fixed to a pair of side members 5 via a pair of rear mounts 11 that are arranged opposite each other in the left-right direction of the vehicle body, and the front mount 10 has lower mounting rigidity than the rear mount 11. As a result, the front mount 10 will break before the rear mount 11, and when the front mount 10 breaks, the electric unit 2 will be supported only by the rear mount 11 located on the upper side in the vertical direction of the vehicle body, making the electric unit 2 more prone to rotation.

[0037] In this embodiment, the rotation shaft of the electric motor 3 and the input shaft of the gearbox 4 are arranged coaxially, and the input shaft and the output shaft of the gearbox are arranged parallel to each other. The housing 12 has a shape in which a protruding portion 12B, which houses the output shaft, protrudes from the main body portion 12A, which houses the electric motor 3 and the input shaft. The front mount 10 is located on the protruding portion 12B, and the rear mount 11 is located on the main body portion 12A. In other words, the electric unit 2 has the electric motor 3 and the gearbox 4 aligned in the left-right direction of the vehicle body, and the rear part of the main body portion 12A has a flatter shape with fewer irregularities when viewed from above. For this reason, even if the electric unit 2 and the dash panel 20 interfere with each other, they will make surface contact, and the electric unit 2 will rotate as described above.

[0038] In this embodiment, the lateral member 8F on the front side of the vehicle body (front lateral member) of the pair of lateral members 8 is positioned vertically so as to overlap with the electric unit 2 when viewed from the front of the vehicle body. As a result, even if the front mount 10 breaks, the load is input to the electric unit 2 via the front lateral member 8F, causing the electric unit 2 to rotate as described above.

[0039] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

Claims

1. An electric vehicle in which an electric unit, comprising an electric motor, inverter, and gearbox housed in a housing, is arranged in a motor room located at the front of the vehicle body, wherein the motor room comprises a pair of side members arranged along the longitudinal direction of the vehicle body, and a suspension member attached to the vehicle body below the side members, the suspension member having a grid shape comprising a pair of longitudinal members extending along the longitudinal direction of the vehicle body, and a front transverse member and a rear transverse member extending in the left-right direction of the vehicle body and connecting the longitudinal members, the longitudinal members having a cross-sectional area that decreases towards the rear of the vehicle body when viewed from the front of the vehicle body, at least from the front end of the vehicle body to the connection with the rear transverse member, the electric unit is arranged within the area enclosed by the pair of longitudinal members and the pair of transverse members when viewed from above, and the front portion of the vehicle body is fixed to the suspension member, and the rear portion of the vehicle body is fixed to the pair of side members from the left-right direction of the vehicle body.

2. An electric vehicle according to claim 1, wherein the front portion of the electric unit is fixed to the lateral member on the front side of the suspension member via one or more front mounts.

3. An electric vehicle according to claim 2, wherein the dash panel located at the rear end of the motor room in the longitudinal direction of the vehicle body has a vertical wall portion extending in the vertical direction of the vehicle body and an inclined portion connected to the lower end of the vertical wall portion and inclined toward the rear of the vehicle body, and the boundary between the vertical wall portion and the inclined portion is located above the fixing point of the electric unit to the side member in the vertical direction of the vehicle body.

4. An electric vehicle according to claim 3, wherein the rear portion of the electric unit is fixed to a pair of side members via a pair of rear mounts arranged opposite to each other in the left-right direction of the vehicle body, and the front mount has lower mounting rigidity than the rear mount.

5. An electric vehicle according to claim 4, wherein the rotating shaft of the electric motor and the input shaft of the gearbox are arranged coaxially, and the input shaft and the output shaft of the gearbox are arranged parallel to each other, and the housing has a shape in which a protruding portion for housing the output shaft protrudes from a main body portion for housing the electric motor and the input shaft, and the front mount is disposed on the protruding portion and the rear mount is disposed on the main body portion.

6. An electric vehicle according to claim 5, wherein the lateral member on the front side of the pair of lateral members is positioned in a vertical position that overlaps with the electric unit when viewed from the front of the vehicle.

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