Electric vehicle

Abstract

To provide an electric vehicle that can suppress damage received by an electric power converter due to a collision load and protect the electric power converter.SOLUTION: An electric vehicle includes: a traveling motor housed in a first case arranged in a front compartment of the vehicle; an electric power converter housed in a second case fixed on the first case by front and rear brackets aligned in a front-rear direction of the vehicle and configured to supply electric power to the motor; and a restricting portion configured to restrict relative displacement of the second case in the front-rear direction with respect to the first case when a collision load directed toward a rear side of the vehicle is received.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an electric vehicle, and more particularly to an electric vehicle having a power converter disposed in a front compartment. [Background technology]

[0002] An electric vehicle has a power converter that converts power from a power source into power suitable for a driving motor and supplies the converted power to the motor. Such a power converter is often located in a front compartment provided at the front of the vehicle. For example, as disclosed in Patent Document 1, a technology is known in which a power converter is fixed on top of a motor case that houses a driving motor inside the front compartment.

[0003] Patent Document 1 discloses a mounting structure for a power converter that supplies power to a driving motor, in which the power converter is fixed onto a motor case within a front compartment by a front bracket and a rear bracket that are aligned in the fore-and-aft direction of the vehicle, with a gap between the power converter and the motor case and the power converter is fixed so that it slopes downwards at the front, and the rear bracket extends from the fastening point with the motor case to the rear of the vehicle, bends upward at the rear, and has its upper end connected to the rear of the power converter, with space secured below the bent part of the rear bracket.

[0004] According to the technology described in Patent Document 1, the rear bracket can move into the space below the bent portion, which increases the distance that the power converter can move downward and rearward as the rear bracket deforms when an obstacle collides with the vehicle from the front. It is described that this structure can protect the power converter from impact during a collision. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-60262 Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the technology described in Patent Document 1, in the event of a frontal collision of the vehicle, the power converter fixed on the motor case may be subjected to a collision load (impact) directed toward the rear of the vehicle and may move a long distance toward the rear of the vehicle. Therefore, if high-voltage components such as connectors are disposed at the rear of the power converter, there is a problem in that the retracted power converter may come into contact with a dash panel or the like disposed behind the power converter, damaging the high-voltage components of the power converter.

[0007] The present disclosure has been made to solve such problems, and aims to provide an electric vehicle that can reduce damage to a power converter caused by a collision load and protect the power converter. [Means for solving the problem]

[0008] An electric vehicle according to one embodiment includes a driving motor housed in a first case arranged in the front compartment of the vehicle, a power converter housed in a second case fixed on top of the first case by front and rear brackets aligned in the fore-and-aft direction of the vehicle and supplying power to the motor, and a restricting section that restricts the relative displacement of the second case in the fore-and-aft direction with respect to the first case when a collision load directed toward the rear of the vehicle is received. [Effects of the Invention]

[0009] The present disclosure can provide an electric vehicle that can reduce damage to a power converter caused by a collision load and protect the power converter. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a plan view showing a configuration of a front part of a vehicle according to a first embodiment. [Figure 2]FIG. 2 is a side view of FIG. [Figure 3] 2 is a side view showing the front part of the vehicle shown in FIG. 1 when the vehicle is involved in a frontal collision. [Figure 4] FIG. 10 is a side view showing the configuration of the front part of a vehicle according to a comparative example. [Figure 5] 5 is a side view showing the front part of the vehicle when the vehicle shown in FIG. 4 has been involved in a frontal collision. DETAILED DESCRIPTION OF THE INVENTION

[0011] Embodiment 1 Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, the present disclosure is not limited to the following embodiments. What is shown in the drawings is only a part of the whole, and in reality, many other configurations that are not shown are included. Furthermore, for clarity of explanation, the following description and drawings have been appropriately simplified.

[0012] In each figure, the F axis indicates the front of the vehicle 100, 200 in the longitudinal direction, the V axis indicates the upper side of the vehicle 100, 200 in the vertical direction, and the H axis indicates the right side of the vehicle 100, 200 in the width direction.

[0013] An overview of an electric vehicle according to a first embodiment will be described with reference to Figures 1 and 2. Figure 1 is a plan view showing the configuration of a front part of the electric vehicle according to the first embodiment. Figure 2 is a side view of Figure 1.

[0014] Hereinafter, a specific example will be described in which the vehicle 100, which is an electric vehicle according to this embodiment, is a hybrid vehicle that has an engine and a motor for running and can run using the power of at least one of the engine and the motor. Note that the vehicle 100 shown in Figures 1 and 2 has one of its distinctive features in the configuration of its front portion, and therefore the description will focus on the configuration of the front portion of the vehicle 100.

[0015] As shown in Figures 1 and 2, a front compartment 10 is provided in the front of a vehicle 100. The vehicle 100 has a bumper reinforcement 11, a pair of side members 12, and a dash panel 13 arranged to surround the front compartment 10. The bumper reinforcement 11 is a skeletal member provided near the front end of the vehicle 100 and extending in the vehicle width direction. The dash panel 13 is a skeletal member that stands vertically to separate the front compartment 10 from the passenger compartment of the vehicle 100. The vehicle 100 also has a hood panel 14 that closes an opening at the upper end of the front compartment 10. In Figure 1, in order to explain the configuration inside the front compartment 10, the components arranged below the hood panel 14, which is shown with a dashed line, are shown with solid lines.

[0016] The pair of side members 12 are skeletal members that extend rearward from both ends of the bumper reinforcement 11 in the vehicle width direction. The side members 12 have stress concentration portions 12a where stress concentrates and bends inward in the vehicle width direction when subjected to a collision load directed toward the rear of the vehicle 100. In the event of a frontal collision in which the front of the vehicle 100 collides with an obstacle, the stress concentration portions 12a bend to absorb the collision energy and protect the passenger compartment. Such stress concentration portions 12a can be formed by locally thinning the side members 12, forming notches, or forming convex corners on the inner side in the vehicle width direction.

[0017] The vehicle 100 also has an engine 1, a transaxle 20, and a power control unit 30 (hereinafter referred to as PCU 30), which are arranged in a front compartment 10. In addition to the engine 1, the transaxle 20, and the PCU 30, various other devices are arranged in the front compartment 10, but these are not shown in the drawings.

[0018] The engine 1 and the transaxle 20 are disposed adjacent to each other in the vehicle width direction, for example. The engine 1 is disposed adjacent to the right side of the transaxle 20 in the vehicle width direction, for example. The transaxle 20 is also disposed adjacent to the right side of the side member 12 on the left side in the vehicle width direction, for example. The engine 1 and the transaxle 20 are suspended between a pair of side members 12.

[0019] The transaxle 20 is configured by integrally incorporating electronic components such as a driving motor into a TA case 21. The TA case 21 is a specific example of a first case disposed in the front compartment 10 of the vehicle 100. The TA case 21 is formed by casting a metal material such as aluminum (Al).

[0020] The TA case 21 houses at least a motor for driving the vehicle 100. The motor is a rotating electric machine capable of supplying driving force for driving the vehicle 100. In addition to the motor, the TA case 21 houses a transmission, a power distribution mechanism, a differential gear, etc. The transmission amplifies the output torque of the engine 1 and the output torque of the motor. The power distribution mechanism combines / distributes the output torque of the engine 1 and the output torque of the motor. The differential gear transmits the power of the motor to the wheels.

[0021] Within the TA case 21, the motor output shaft, the main shaft of the power distribution mechanism, and the main shaft of the differential gear all extend in the vehicle width direction and are aligned parallel to one another. As shown in Fig. 2, the top surface 21a of the TA case 21 is inclined relative to the horizontal so that these three shafts are appropriately positioned. In more detail, the top surface 21a is inclined downward toward the front so that the front portion is positioned lower than the rear portion in the fore-and-aft direction.

[0022] The PCU 30 is configured by integrally incorporating electronic components such as an inverter into a PCU case 31. The PCU case 31 is a specific example of a second case fixed onto the TA case 21 by a front bracket 41 and a rear bracket 42 aligned in the longitudinal direction of the vehicle 100. The PCU case 31 is formed by casting a metal material such as aluminum (Al).

[0023] Because the upper surface 21a is inclined downward toward the front, the PCU case 31 fixed on top of the TA case 21 is also inclined downward toward the front so that its front portion in the front-to-rear direction is positioned lower than its rear portion. In other words, the lower surface 31a of the PCU case 31 is inclined downward toward the front. The PCU case 31 is disposed on top of the TA case 21 with a gap between them. This gap is maintained by the front bracket 41 and the rear bracket 42.

[0024] Each of the front bracket 41 and the rear bracket 42 has an L-shape when viewed from the side. Each of the front bracket 41 and the rear bracket 42 is a support member that supports the PCU case 31. Each of the front bracket 41 and the rear bracket 42 can be formed, for example, by pressing a metal plate such as a steel plate.

[0025] The front bracket 41 connects the front portion (front surface in this embodiment) of the PCU case 31 to the TA case 21. One end of the front bracket 41 is fixed to the front portion of the upper surface 21a, and the other end is fixed to the lower portion of the front surface of the PCU case 31. The front bracket 41 can be fastened to each of the TA case 21 and the PCU case 31 by fastening members such as bolts. It is preferable to interpose a vibration-isolating bushing between the front bracket 41 and the PCU case 31 to protect the inverter in the PCU case 31 from vibrations.

[0026] The rear bracket 42 connects the rear portion (rear surface in this embodiment) of the PCU case 31 to the TA case 21. One end of the rear bracket 42 is fixed to the rear portion of the upper surface 21a, and the other end is fixed to the lower part of the rear surface of the PCU case 31. The rear bracket 42 can be fastened to each of the TA case 21 and the PCU case 31 by fastening members such as bolts. It is preferable to interpose a vibration-isolating bushing between the rear bracket 42 and the PCU case 31 to protect the inverter inside the PCU case 31 from vibrations.

[0027] The PCU case 31 houses at least an inverter. The inverter is a specific example of a power converter that supplies power to the motor. The inverter has a voltage converter circuit and an inverter circuit, and boosts DC power from the battery of the vehicle 100, then converts it into AC power suitable for driving the motor and supplies it to the motor. The inverter may also convert AC power generated by the motor into DC power, then reduce the voltage and supply it to the battery.

[0028] In addition to the inverter, the PCU case 31 also houses a processor that controls the operation of the inverter, etc. A connector may be disposed at the rear of the PCU case 31. The connector is a high-voltage connector to which a power cable that electrically connects the inverter to the motor is connected. The connector disposed at the rear of the PCU case 31 protrudes from the rear (e.g., the rear surface) of the PCU case 31 toward the rear of the vehicle 100, for example.

[0029] In order to protect the inverter equipped with such high-voltage components as connectors from collision loads (impact) caused by a frontal collision of the vehicle 100, the vehicle 100 of this embodiment has a regulating section 50 that regulates the relative displacement of the PCU case 31 with respect to the TA case 21 in the fore-and-aft direction of the vehicle 100.

[0030] The restricting portion 50 is disposed in the gap between the TA case 21 and the PCU case 31. The restricting portion 50 has, for example, a first restricting portion 51 and a second restricting portion 52. The first restricting portion 51 is provided on the upper surface 21a of the TA case 21 facing the PCU case 31 so as to protrude toward the PCU case 31. The first restricting portion 51 is, for example, formed integrally with the TA case 21. However, the first restricting portion 51 may be a member separate from the TA case 21. If the first restricting portion 51 is a member separate from the TA case 21, the first restricting portion 51 is fixed to the upper surface 21a by, for example, a fastening member such as a bolt or by welding.

[0031] The first restricting portion 51 is provided at the rear of the upper surface 21a. The first restricting portion 51 has a width equal to or less than the width of the upper surface 21a so as not to interfere with other devices. In addition, the first restricting portion 51 has a tapered shape that narrows from the front to the rear in the front-to-rear direction when viewed from the side so as not to interfere with other devices. Furthermore, the first restricting portion 51 has a contact surface 51a on the front side that can come into contact with a contact surface 52a of the second restricting portion 52 when a collision load is applied.

[0032] The second restricting portion 52 is provided on the lower surface 31a of the PCU case 31 that faces the TA case 21 so as to protrude towards the TA case 21. The second restricting portion 52 is, for example, formed integrally with the PCU case 31. However, the second restricting portion 52 may be a member separate from the PCU case 31. When the second restricting portion 52 is a member separate from the PCU case 31, the second restricting portion 52 is fixed to the lower surface 31a by, for example, a fastening member such as a bolt or by welding.

[0033] The second restricting portion 52 is provided in the front portion of the lower surface 31a. The second restricting portion 52 has a width equal to or less than the width of the lower surface 31a so as not to interfere with other devices. The second restricting portion 52 also has a tapered shape that narrows from the rear to the front in the front-to-rear direction when viewed from the side so as not to interfere with other devices. Furthermore, the second restricting portion 52 has a contact surface 52a on the rear side that can come into contact with the contact surface 51a of the first restricting portion 51 when a collision load is applied.

[0034] The first restricting portion 51 and the second restricting portion 52 are arranged so that the contact surface 51a and the contact surface 52a face each other in the front-rear direction. Therefore, when a collision load is applied to the restricting portion 50, the contact surface 52a can come into contact with the contact surface 51a. In this way, when a collision load is applied to the restricting portion 50, the first restricting portion 51 and the second restricting portion 52 come into surface contact with each other to restrict relative displacement of the PCU case 31 with respect to the TA case 21 in the front-rear direction, thereby suppressing displacement (rearward movement) of the PCU case 31 with respect to the TA case 21.

[0035] Here, referring to Fig. 4, problems that arise when the restricting unit 50 is omitted will be described using a vehicle 200 according to a comparative example as an example. Fig. 4 is a side view showing the configuration of the front part of the vehicle according to the comparative example. Vehicle 200 shown in Fig. 4 is similar to vehicle 100 except that it does not have restricting unit 50.

[0036] Next, the front part of the vehicle 200 in a frontal collision will be described with reference to Fig. 5. Fig. 5 is a side view showing the front part of the vehicle when the vehicle shown in Fig. 4 has undergone a frontal collision. In Fig. 5, the collision load F directed toward the rear of the vehicle 200 is indicated by an outlined arrow. In Fig. 5, the bumper reinforcement 11, side member 12, hood panel 14, TA case 21, and PCU case 31 before the collision are indicated by dashed lines.

[0037] As shown in Figure 5, when the vehicle 200 collides head-on with the honeycomb barrier HB, the side members 12 and the hood panel 14 are deformed by the collision load F. The side members 12, which are deformed by the collision load F, absorb the impact at the initial stage of the collision by bending the stress concentration portions 12a. Meanwhile, when the hood panel 14, which is deformed by the collision load F, comes into contact with the PCU case 31, the collision load F is transmitted from the hood panel 14 to the PCU case 31. In this way, the PCU case 31, which has received the collision load F, moves backward toward the rear of the vehicle 200.

[0038] Furthermore, since the TA case 21 is fixed to the PCU case 31 by the front bracket 41 and the rear bracket 42, the collision load F is also transmitted from the PCU case 31 to the TA case 21 via the front bracket 41 and the rear bracket 42. Therefore, as the PCU case 31 moves backward, the TA case 21 also moves backward.

[0039] Furthermore, because the front bracket 41 and the rear bracket 42 are fixed to the PCU case 31, the collision load F is transmitted from the PCU case 31. Therefore, when the PCU case 31 of the vehicle 200 is subjected to the collision load F, the collision load F applied to the front bracket 41 and the rear bracket 42 may cause at least one of the brackets, the front bracket 41 and the rear bracket 42, to deform or break. As a result, in the vehicle 200, the PCU case 31 may move backward to a position where it comes into contact with the dash panel 13. If the PCU case 31 moves backward to a position where it comes into contact with the dash panel 13, there is a problem in that the moved backward PCU case 31 may come into contact with the dash panel 13, which may damage high-voltage components such as connectors arranged at the rear of the PCU case 31 (i.e., behind the inverter).

[0040] Therefore, in order to prevent deformation or breakage of the front bracket 41 and the rear bracket 42, it is conceivable to increase the rigidity of at least one of the front bracket 41 and the rear bracket 42. However, in order to sufficiently increase the rigidity of the bracket, it is necessary to make the bracket larger or to provide a reinforcing member. Therefore, increasing the rigidity of the bracket would result in an increase in the vehicle weight, and therefore such a measure is not desirable.

[0041] In contrast, the vehicle 100 according to this embodiment has a driving motor housed in a TA case 21 arranged in the front compartment 10 of the vehicle 100, and a power converter that supplies power to the motor and is housed in a PCU case 31 fixed onto the TA case 21 by a front bracket 41 and a rear bracket 42 that are aligned in the fore-and-aft direction of the vehicle 100. The vehicle 100 according to this embodiment also has a restricting section 50 that restricts relative displacement of the PCU case 31 with respect to the TA case 21 in the fore-and-aft direction when a collision load F directed toward the rear of the vehicle 100 is received.

[0042] The effect of the vehicle 100 configured in this manner will be described with reference to Fig. 3. Fig. 3 is a side view showing the front of the vehicle shown in Fig. 1 when it has collided. In Fig. 3, the collision load F is indicated by an outlined arrow. In Fig. 3, the bumper reinforcement 11, side member 12, hood panel 14, TA case 21, and PCU case 31 before the collision are indicated by dashed lines.

[0043] As shown in Figure 3, when the vehicle 100 collides head-on with the honeycomb barrier HB, the side members 12 and the hood panel 14 are deformed by the collision load F. The side members 12, which have been deformed by the collision load F, absorb the impact at the initial stage of the collision by bending the stress concentration portions 12a. Meanwhile, when the hood panel 14, which has been deformed by the collision load F, comes into contact with the PCU case 31, the collision load F is transmitted from the hood panel 14 to the PCU case 31. The PCU case 31, which has received the collision load F in this way, moves backward toward the rear of the vehicle 100 together with the TA case 21, to which the collision load F is transmitted from the PCU case 31.

[0044] In the vehicle 100, while the PCU case 31 and the TA case 21 are moved backward to a position where the second restricting portion 52 can come into contact with the first restricting portion 51, the amount of rearward displacement of the PCU case 31 is relatively greater than the amount of rearward displacement of the TA case 21, so the first restricting portion 51 approaches the second restricting portion 52. Then, when the PCU case 31 and the TA case 21 are moved backward to a position where the second restricting portion 52 can come into contact with the first restricting portion 51, the contact surface 52a comes into contact with the contact surface 51a, thereby restricting the relative displacement of the PCU case 31 in the fore-and-aft direction with the TA case 21.

[0045] Furthermore, contact surface 52a comes into contact with contact surface 51a, thereby transmitting collision load F between first restricting portion 51 and second restricting portion 52. In this manner, in vehicle 100, restricting portion 50 serves as a transmission path for collision load F, thereby reducing the collision load F transmitted from PCU case 31 to at least one of front bracket 41 and rear bracket 42 when PCU case 31 is subjected to collision load F. Therefore, vehicle 100 having restricting portion 50 can prevent PCU case 31 from moving backward to a position where it contacts dash panel 13, which would otherwise be caused by deformation or destruction of the bracket due to collision load F applied to the bracket when PCU case 31 is subjected to collision load F. As a result, high-voltage components such as connectors arranged at the rear of PCU case 31 (i.e., at the rear of the inverter) are prevented from being damaged when the PCU case 31 moves backward and contacts dash panel 13.

[0046] As described above, according to the vehicle 100 of this embodiment, it is possible to suppress damage to the power converter caused by the collision load F and to protect the power converter.

[0047] Here, it is preferable that the second restricting portion 52 of the restricting portion 50 can fit into the first restricting portion 51 when the collision load F is received. In this case, for example, it is preferable that the first restricting portion 51 is provided with a recess recessed rearward from the contact surface 51a, and the second restricting portion 52 is provided with a protrusion protruding rearward from the contact surface 52a to fit into the recess.

[0048] The restricting portion 50, in which the second restricting portion 52 can be fitted into the first restricting portion 51, is fitted to each other so as to restrict the relative displacement of the PCU case 31 in the front-to-rear direction relative to the TA case 21 when a collision load F is applied, thereby suitably preventing the PCU case 31 from moving backward. As a result, the inverter can be protected more reliably than when the contact surface 52a simply contacts the contact surface 51a.

[0049] The present disclosure is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the present disclosure. For example, in the above-described embodiment, the vehicle 100 is a hybrid vehicle having an engine and a motor for driving, but the vehicle 100 may be an electric vehicle without an engine 1, or may be a fuel cell vehicle. [Explanation of symbols]

[0050] 1 engine 10 Front compartment 11 Bumper reinforcement 12 Side member 12a Stress concentration area 13 Dash panel 14 Hood panel 20 Transaxle 21 TA case 21a Top 30 PCU (power control unit) 31 PCU case 31a bottom 41 Front bracket 42 Rear bracket 50 Restriction portion 51 First restriction portion 51a, 52a Contact surface 52 Second restriction portion 100, 200 Vehicle HB Honeycomb Barrier

Claims

1. a driving motor housed in a first case disposed in a front compartment of the vehicle; a power converter that is housed in a second case fixed onto the first case by a front bracket and a rear bracket that are aligned in the front-rear direction of the vehicle, and that supplies power to the motor; a restricting portion that restricts relative displacement of the second case relative to the first case in the front-rear direction when a collision load directed toward the rear of the vehicle is received; An electric vehicle having:

2. The restriction portion is a first restricting portion provided on an upper surface of the first case facing the second case so as to protrude toward the second case; a second restricting portion provided on a lower surface of the second case facing the first case so as to protrude toward the first case; and The electric vehicle according to claim 1 , wherein the contact surface of the second restricting portion is capable of coming into contact with the contact surface of the first restricting portion when the collision load is applied.

3. The restriction portion is The electric vehicle according to claim 2 , wherein the second restricting portion is capable of fitting into the first restricting portion when the collision load is applied.

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