Electric vehicle

Abstract

According to the present invention, there is provided an electric vehicle in which a radiator for cooling and an electrical component case in which an electrical component is accommodated are disposed, in order from the front along the longitudinal direction of the vehicle body, in a drive device accommodation cabin provided in the front section of the vehicle. In this electric vehicle, the electric component case is provided with a protector on the front side in the longitudinal direction of the vehicle body. In a top view, the protector includes an absorption part in which an end part, on the side close to the center of the vehicle body in the lateral direction of the vehicle body, is closest to the radiator, and an end part on the side closer to the side surface of the vehicle body in the lateral direction of the vehicle body is the most distant from the radiator.

Description

Electric vehicles

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

[0002] Electric vehicles that use an electric motor as a power source for traveling are known, such as electric vehicles, hybrid vehicles, fuel cell vehicles, etc. In electric vehicles, electric power supplied from a battery is converted into AC power by electrical components such as an inverter (power conversion device) and then applied to the electric motor.

[0003] Electrical components such as an inverter are often housed in a case made of metal such as an aluminum alloy, and are housed together with the electric motor in a drive unit housing provided at the front of the vehicle.

[0004] The drive unit housing also houses accessories such as a radiator. Therefore, if the vehicle collides with another vehicle or an external structure, the vehicle body may deform and the accessories may interfere with the case. For example, if an electric motor for a radiator fan (hereinafter also referred to as a fan motor) interferes, the housing of the electric motor may be damaged, resulting in a current leak, because the housing of the electric motor is generally stronger than aluminum alloy. To solve this problem, JP 5712956B discloses a configuration in which the inverter case is fixed to a fixed structure of the vehicle using first and second brackets that deform when subjected to a collision load caused by a vehicle collision.

[0005] However, in the configuration described in the above document, the fan motor moves during a vehicle collision and interferes with the inverter case, causing a collision load to be input to the first and second brackets through the inverter case, deforming the first and second brackets. This can damage the inverter case due to interference with the electric motor. Furthermore, increasing the strength of the inverter case can damage the electric motor and cause a short circuit.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an electric vehicle that can prevent damage to an electrical component case due to interference with a fan motor or the like during a vehicle collision.

[0007] According to one aspect of the present invention, there is provided an electric vehicle having a drive unit housing provided in a front portion of the vehicle, in which a cooling radiator and an electrical component case housing electrical components are arranged in this order from front to back along the fore-and-aft direction of the vehicle body. In this vehicle, the electrical component case has a protector on the front side in the fore-and-aft direction of the vehicle body, and the protector has an absorption section whose end closest to the center of the vehicle in the left-right direction of the vehicle body is closest to the radiator and whose end closest to a side of the vehicle in the left-and-aft direction of the vehicle body is farthest from the radiator.

[0008] Fig. 1 is a front view of a drive unit provided in an electric vehicle. Fig. 2 is a perspective view of the drive unit. Fig. 3 is a top view (partial cross-sectional view) showing the drive unit 1 mounted on a vehicle body. Fig. 4 is a perspective view of a protector. Fig. 5 is an enlarged view of the area around the protector installation position when the protector is installed. Fig. 6 is an enlarged view of the area around the protector installation position when the protector is removed.

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] In the following description, "front" refers to the forward direction of the vehicle. "Left" and "right" refer to the left and right, respectively, in a top view with the forward direction of the vehicle being the upper side. In other words, the left-right direction of the vehicle body refers to a direction perpendicular to the forward direction of the vehicle in a top view with the forward direction of the vehicle being the upper side. "Up" and "down" refer to the top and bottom, respectively, when the vehicle body is viewed from the front. In other words, the up-down direction of the vehicle body refers to a direction perpendicular to the left-right direction of the vehicle body in a front view of the vehicle body. [Configuration]

[0011] First, a drive unit 1 provided in an electric vehicle according to this embodiment will be described with reference to Figures 1 to 3. Figure 1 is a front view of the drive unit 1 provided in an electric vehicle according to this embodiment. Figure 2 is a perspective view of the drive unit 1. Figure 3 is a top view showing the drive unit 1 mounted on a vehicle body, with a portion shown in cross section.

[0012] In this embodiment, the electric vehicle is a so-called series hybrid vehicle. The drive unit 1 includes a motor housing 2 that houses a traction motor (not shown) and a generator motor (not shown), a gear housing 3 that houses a reducer (not shown) and a speed increaser (not shown), an electrical component case (hereinafter also referred to as an inverter case) 4 that houses an inverter (not shown), and a protector 5. An internal combustion engine (not shown) is connected to the right side of the drive unit 1.

[0013] The electric vehicle may be a so-called BEV (Battery Electric Vehicle). In this case, the drive unit 1 is different in that only the traction motor is housed in the motor housing 2 and only the reducer is housed in the gear housing 3, but the present invention is still applicable.

[0014] In the drive unit 1, the motor housing 2 and the gear housing 3 are connected and aligned in the left-right direction of the vehicle body. The inverter case 4 is made of metal such as aluminum alloy and is provided on the upper surface of the motor housing 2.

[0015] The drive unit 1 is accommodated in a drive unit accommodation chamber 30 provided in the front of the vehicle. A cooling radiator (hereinafter also simply referred to as "radiator") 20 is disposed in the drive unit accommodation chamber 30 on the vehicle body front side of the drive unit 1. The radiator 20 is provided with an electric fan 21 driven by an electric motor (hereinafter also referred to as "fan motor") on the surface on the vehicle body rear side.

[0016] Generally, vehicles are designed to absorb impact and minimize deformation of the passenger compartment during a frontal collision, in which the front of the vehicle collides with another vehicle or an external structure. Therefore, deformation of the vehicle body during a frontal collision may cause the electric fan 21 to move toward the rear of the vehicle and collide with the drive unit 1. The housing of a fan motor is generally made of a relatively high-strength material, such as steel, and is therefore often stronger than the inverter case 4. Therefore, if the electric fan 21 collides with the inverter case 4, which is made of an aluminum alloy, the inverter case 4 may be damaged, potentially resulting in a current leak or other problem.

[0017] In this embodiment, therefore, the protector 5 is provided on the front side of the inverter case 4, that is, between the inverter case 4 and the electric fan 21 of the radiator 20, to prevent leakage or short circuit due to a frontal collision.

[0018] The structure and installation position of the protector 5 will now be described with reference to Figures 3 to 6. Figure 4 is a perspective view of the protector 5. Figure 5 is an enlarged view of the area around the protector installation position when the protector 5 is installed. Figure 6 is an enlarged view of the area around the protector installation position when the protector 5 is removed.

[0019] The protector 5 includes an absorbing section 10 that absorbs the impact when the electric fan 21 collides with it, an upper mounting section 12 provided on the upper side of the absorbing section 10 in the vertical direction of the vehicle body, and a lower mounting section 13 provided on the lower side in the vertical direction of the vehicle body. The protector 5 also includes a leg section 11 that extends from one end of the absorbing section 10 on the center side in the horizontal direction of the vehicle body toward the inverter case 4 and has an abutment surface 11A at its tip that abuts against the inverter case 4. However, the leg section 11 is not an essential component.

[0020] The absorbing section 10 has a stepped shape in top view, including a plurality of uneven surfaces 10A to 10C, with the surface closest to the center of the vehicle body in the left-right direction being closest to the radiator 20 and the surface closest to the side of the vehicle body in the left-right direction being farthest from the radiator 20. The number of steps in the absorbing section 10 is not limited to three and can be set appropriately depending on the expected input load. Furthermore, the shape of the absorbing section 10 is not limited to a stepped shape, and may be, for example, a slope shape in which the end closest to the center of the vehicle body in the left-right direction is closest to the radiator 20 and the end closest to the side of the vehicle body in the left-right direction is farthest from the radiator 20.

[0021] The shapes of the upper mounting portion 12 and the lower mounting portion 13 are not particularly limited and may be designed appropriately depending on the shapes of the inverter case 4 and the motor housing 2, etc.

[0022] 3, when viewed from the front of the vehicle body (hereinafter referred to as the front view), the protector 5 having the above-described configuration is disposed in a position where the rotor shaft (the rotation axis in FIG. 3) of the electric fan 21 overlaps with the surface 10B of the absorbing portion 10. Note that the surface that overlaps with the rotor shaft is not limited to the surface 10B, but may be the surface 10A or the surface 10C.

[0023] The inverter case 4 includes a front wall 4A extending in the left-right direction of the vehicle body on the radiator 20 side in a top view, and side walls 4B extending rearward from the ends of the front wall 4A. The inverter case 4 further includes a rear wall (not shown) provided at a position opposite the front wall 4A, and a lid 4C that closes an opening defined by the front wall 4A, the pair of side walls 4B, and the upper end of the rear wall.

[0024] The protector 5 is disposed such that a portion of the surface 10A overlaps the intersection A between the front wall 4A and the side wall 4B in a front view.

[0025] Next, the effect of providing the protector 5 will be described with reference to FIG.

[0026] Here, an offset collision occurring from the diagonally front right of the vehicle body will be described.

[0027] During the offset collision, of the pair of body members arranged in the longitudinal direction of the vehicle, mainly the right body member of the vehicle deforms, and the motor portion of the electric fan 21 (shown by the broken line in Figure 3) is pushed toward the rear of the vehicle while tilting as shown in Figure 3. Compared to a head-on collision in which the impact load is applied almost evenly to the pair of body members, in an offset collision the impact load is biased toward one of the body members, resulting in a greater deformation of the body members. As a result, the movement of the electric fan 21 also increases.

[0028] In this case, if the absorbing portion 10 of the protector 5 is a single surface parallel to the radiator 20, when the electric fan 21 comes into contact with the absorbing portion 10, the absorbing portion 10 will deform into a V shape with the contact point as its apex. In other words, the load will be concentrated at the contact point. If the electric fan 21 is pushed further toward the rear of the vehicle and the contact point hits the inverter case 4, the load will be concentrated at one point on the inverter case 4, making the inverter case 4 prone to damage.

[0029] In contrast, with the configuration of this embodiment, the motor portion first strikes surface 10A, which is located closest to the front of the vehicle. As the electric fan 21 is further pushed toward the rear of the vehicle, surface 10A is similarly pushed toward the rear of the vehicle and deforms, becoming flush with surface 10B in the longitudinal direction of the vehicle. As the electric fan 21 is further pushed toward the rear of the vehicle, surfaces 10A and 10B deform and become flush with surface 10C in the longitudinal direction of the vehicle. This gradual deformation of the absorbing portion 10 attenuates the impact energy. The absorbing portion 10 then ultimately deforms until it becomes flat, so that the entire surfaces 10A to 10C absorb the impact energy. In other words, the deformation of surfaces 10A and 10B attenuates the impact energy, and the surface pressure on the absorbing portion 10 can be further reduced. This reduces the impact load input to the inverter case 4 and prevents damage to the inverter case 4. Furthermore, even when the absorption section 10 has a sloped shape, the electric fan 21 first hits the part that is closest to the front of the vehicle body, and as the amount of pushing of the electric fan 21 toward the rear of the vehicle body increases, the absorption section 10 deforms and finally becomes flat, thereby similarly reducing the surface pressure.

[0030] In this embodiment, the protector 5 is disposed so that the intersection of the front wall 4A and the side wall 4B overlaps the surface 10A of the absorbing portion 10 in a front view. The intersection is supported by the side wall 4B extending in the fore-and-aft direction of the vehicle body, and therefore has higher rigidity against a load directed toward the rear of the vehicle body than other portions of the front wall 4A. Therefore, the intersection bears the receding surface 10A, which increases the likelihood that the inverter case 4 will be prevented from being damaged.

[0031] Furthermore, by providing the leg portion 11 having the surface 11A that contacts the inverter case 4, the impact load is received not only by the surfaces 10A to 10C but also by the surface 11A, and the impact load can be further dispersed.

[0032] In the case of a head-on collision, the electric fan 21 is pushed toward the rear of the vehicle without tilting. Even in this case, the electric fan 21 first hits the surface 10A of the protector 5, and as the amount of pushing into the fan increases, it deforms in the same way as in the case of an offset collision, thereby attenuating the collision energy. Therefore, in the case of a head-on collision, the same effects as in the case of an offset collision can be obtained.

[0033] As described above, this embodiment provides an electric vehicle in which a radiator 20 and an inverter case (electrical component case) 4 accommodating electrical components such as an inverter are arranged in a drive unit accommodation chamber 30 provided at the front of the vehicle in the vehicle longitudinal direction, in that order from front to back. The inverter case 4 includes a protector 5 on the front side in the vehicle longitudinal direction. In a top view, the protector 5 includes an absorption section 10 whose end closest to the center of the vehicle in the vehicle transverse direction is closest to the radiator 20 and whose end closest to the side of the vehicle in the vehicle transverse direction is farthest from the radiator 20. When the electric fan 21 is pushed rearward, the absorption section 10 gradually collapses toward the vehicle rear starting from the portion closest to the radiator 20, thereby attenuating collision energy. Ultimately, the entire absorption section 10 bears the load from the electric fan 21. This distributes the load and reduces surface pressure, thereby reducing damage to the inverter case 4 compared to when the load is concentrated.

[0034] In this embodiment, the protector 5 is fixed to and supported by the inverter case 4 at an upper mounting portion 12 provided on the upper side of the absorbing portion 10 in the vertical direction of the vehicle body, and a lower mounting portion 13 provided on the lower side of the absorbing portion 10 in the vertical direction of the vehicle body. In other words, the absorbing portion 10 is fixed at its upper and lower sides. Therefore, when the electric fan 21 hits the absorbing portion 10, the protector 5 as a whole is not pushed toward the rear of the vehicle body, and the absorbing portion 10 is deformed.

[0035] In this embodiment, the radiator 20 is provided with an electric fan 21 on the surface facing the inverter case 4, and in a front view, the rotor shaft of the electric motor that drives the electric fan 21 overlaps with any part of the absorbing portion 10. This makes it easier for the electric fan 21 to come into contact with the absorbing portion 10 of the protector 5 in the event of a frontal collision of the vehicle.

[0036] In this embodiment, the inverter case 4 includes a front wall 4A extending in the left-right direction of the vehicle body on the radiator 20 side in a top view, and a side wall 4B extending from an end of the front wall 4A toward the rear of the vehicle body. The absorbing portion 10 of the protector 5 has a staircase shape with a plurality of uneven surfaces, and a surface 10A of the uneven surfaces that is closest to the radiator 20 overlaps with the intersection of the front wall 4A and the side wall 4B in a front view. The presence of the side wall 4B gives the intersection high rigidity against a load toward the rear of the vehicle body, so it is unlikely to be damaged even if it hits with surface 10A.

[0037] In this embodiment, the protector 5 may include legs 11 that extend from an end face of the surface 10A of the absorbing part 10 that is closer to the radiator 20 toward the inverter case 4 and have contact surfaces 11A at their tips that come into contact with the inverter case 4. In this case, the presence of the contact surfaces 11A further enhances the effect of reducing the surface pressure described above.

[0038] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

Claims

1. An electric vehicle in which a cooling radiator and an electrical component case containing electrical components are arranged in that order from front to back along the longitudinal direction of the vehicle within a drive unit housing provided at the front of the vehicle, wherein the electrical component case is provided with a protector on the front side in the longitudinal direction of the vehicle, and the protector has an absorption section in which, in a top view, the end closest to the center of the vehicle in the transverse direction of the vehicle is closest to the radiator and the end closest to the side of the vehicle in the transverse direction of the vehicle is furthest from the radiator.

2. An electric vehicle according to claim 1, wherein the protector is fixed to and supported by the electrical component case at an upper mounting portion provided above the absorbing portion in the vertical direction of the vehicle body, and a lower mounting portion provided below the absorbing portion in the vertical direction of the vehicle body.

3. An electric vehicle according to claim 1, wherein the radiator is provided with an electric fan on the surface facing the electrical component case, and the rotor shaft of an electric motor that drives the electric fan overlaps any part of the absorbing section in a front view.

4. An electric vehicle as claimed in claim 1, wherein the electrical component case comprises a front wall extending in the left-right direction of the vehicle body on the radiator side in top view, and a side wall extending from the end of the front wall towards the rear of the vehicle body, the absorbing section of the protector having a stepped shape with a plurality of uneven surfaces, and the uneven surface closest to the radiator overlaps with the intersection of the front wall and the side wall in front view.

5. An electric vehicle as described in claim 1, wherein the protector has a leg portion that extends from the end face of the absorption section closest to the radiator in the direction of the electrical component case and has a contact surface at its tip that contacts the electrical component case.

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