Electric vehicles

Abstract

To provide an electric vehicle capable of suppressing the exposure of a power control device to the outside of a case.SOLUTION: A vehicle 10 is equipped with a drive unit 96 in which a transaxle 98 including an electric motor functioning as a power source and a power control unit 54 controlling power received by the electric motor are stored in the same case 18, and a left side member 80L to which the drive unit 96 is attached through a fastening member 82. (a) The case 18 has an upper space U and a lower space L vertically separated in the case 18, (b) the power control unit 54 is stored in the upper space U and the transaxle 98 is stored in the lower space L, (c) in the upper space U, a base plate 72b is provided, and (d) when viewed from a vehicle width direction, a fragile portion 80Lw of the left side member 80L is disposed at a position superimposed with the base plate 72b.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electric vehicle equipped with an electromechanical integrated unit in which a drive unit including an electric motor that functions as a power source and a power control unit that controls the power supplied and received by the electric motor are housed in the same case. [Background technology]

[0002] There is known a vehicle equipped with a drive unit in which a drive device including an electric motor that functions as a power source and a power control device including an inverter that controls the power received by the electric motor are housed in separate cases, and the separate cases are connected to each other by bolt fastening. For example, a vehicle such as that described in Patent Document 1 is disclosed. In the vehicle described in Patent Document 1, the drive unit is attached to a side member via a fastening member. When viewed in the vehicle width direction, the case housing the power control device is positioned higher than the side member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 176602 Summary of the Invention [Problem to be solved by the invention]

[0004] When the drive unit described in Patent Document 1 is made low-profile, the case housing the power control device may be positioned in a position that overlaps a weak portion of the side member when viewed in the vehicle width direction. In this case, there is a risk that the side member will bend or break at the weak portion during a collision, and the bent or broken side member will press the case housing the power control device in the vehicle width direction. In the vehicle described in Patent Document 1, the portion where the separate case is bolted breaks or bends, thereby absorbing the energy that the bent or broken side member would use to press the case housing the power control device. This prevents damage to the case housing the power control device and prevents the high-voltage power control device from being exposed to the outside of the case.

[0005] To simplify the shape of the drive unit, it is possible to house the drive device and the power control device in the same case. For example, the power control device may be housed in the upper space and the drive device in the lower space of the same case. In this case, if a bent or broken side member presses against the case portion in the upper space, there is no part to absorb the energy, which may damage the case portion in the upper space. If the case portion in the upper space is damaged, the high-voltage power control device may be exposed to the outside of the case, which may cause a current leak.

[0006] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide an electric vehicle in which the power control device can be prevented from being exposed to the outside of the case. [Means for solving the problem]

[0007] The gist of the present invention is an electric vehicle comprising an electromechanical integrated unit in which a drive device including an electric motor that functions as a power source and a power control device that controls the power exchanged by the electric motor are housed in the same case, and a side member to which the electromechanical integrated unit is attached via a fastening member, wherein (a) the case has an upper space and a lower space separated vertically within the case, (b) the power control device is housed in the upper space and the drive device is housed in the lower space, (c) a plate is provided in the upper space, and (d) when viewed in the vehicle width direction, a weak portion of the side member is positioned so as to overlap with the plate. [Effects of the Invention]

[0008] According to the electric vehicle of the present invention, (a) the case has an upper space and a lower space separated vertically within the case, (b) the power control device is housed in the upper space and the drive device is housed in the lower space, (c) a plate is provided within the upper space, and (d) the weak portion of the side member is positioned to overlap the plate as viewed in the vehicle width direction. If the side member of the electric vehicle is bent or broken at the weak portion due to a collision, the bent or broken side member will press against the case in the vehicle width direction and attempt to break through it. However, when the weak portion of the side member is positioned to overlap the plate as viewed in the vehicle width direction, the plate improves the strength of the case compared to when it is not. This prevents the case from being broken through by the bent or broken side member, thereby preventing the case from being damaged and the power control device, which is at high voltage, from being exposed outside the case, making it easier to ensure safety. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of a schematic configuration of a hybrid vehicle to which the present invention is applied; [Figure 2] FIG. 2 is a diagram illustrating an example of an electrical configuration of a power control unit, etc. [Figure 3]FIG. 2 is a diagram illustrating an example of a schematic configuration of a drive unit. [Figure 4] 1 is a diagram illustrating an example of a state in which a drive unit is mounted on a hybrid vehicle, where (a) is a side view from the left side facing the front of the hybrid vehicle, and (b) is a top view from above the hybrid vehicle. [Figure 5] FIG. 10 is a diagram illustrating an example of a state in which a drive unit is attached to a left side member, as viewed from above the hybrid vehicle. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5, illustrating an example of a state in which the drive unit is attached to the left side member. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 5, illustrating an example of a state in which the drive unit is attached to the left side member. [Figure 8] 10A and 10B are diagrams illustrating a state in which a left side member is broken due to a frontal collision. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the drawings in the embodiments are appropriately simplified or modified, and the dimensional ratios and shapes of the various parts are not necessarily drawn accurately. [Example]

[0011] 1 is a diagram illustrating an example of a schematic configuration of a hybrid vehicle 10 (hereinafter simply referred to as "vehicle 10") to which the present invention is applied. Vehicle 10 corresponds to the "electric vehicle" in the present invention.

[0012] The vehicle 10 is a hybrid vehicle equipped with an engine 12 that functions as a power source, a first electric motor MG1 and a second electric motor MG2 that are electric motors that also function as power sources, a pair of drive wheels 14, and a power transmission device 16.

[0013] The engine 12 is a well-known internal combustion engine. The first electric motor MG1 and the second electric motor MG2 are, for example, rotating electric machines having a motor function and a generator function, and are so-called motor generators. The first electric motor MG1 and the second electric motor MG2 are housed in a non-rotatable case 18, which is a non-rotating member attached to the vehicle body. The first electric motor MG1 and the second electric motor MG2 each correspond to the "electric motor" in the present invention.

[0014] The power transmission device 16 is provided in a power transmission path between the engine 12 and the pair of drive wheels 14, and in a power transmission path between the second electric motor MG2 and the pair of drive wheels 14. The power transmission device 16 includes, within a case 18, a damper 20, an input shaft 22, a transmission unit 24, a compound gear 26, a driven gear 28, a driven shaft 30, a final gear 32, a differential gear 34, a reduction gear 36, and the like. The input shaft 22 functions as an input rotating member of the transmission unit 24 and is connected to the crankshaft 12a of the engine 12 via the damper 20 and the like. The transmission unit 24 is connected to the input shaft 22. The compound gear 26 is a rotating body on the output side of the transmission unit 24. A drive gear 26a is formed on a portion of the outer circumferential surface of the compound gear 26. The drive gear 26a is the output rotating member of the transmission unit 24. The driven gear 28 meshes with the drive gear 26a. The driven shaft 30 fixes the driven gear 28 and the final gear 32 so that they cannot rotate relative to each other. The final gear 32 has a smaller diameter than the driven gear 28 and meshes with a differential ring gear 34a of the differential gear 34. The reduction gear 36 has a smaller diameter than the driven gear 28 and meshes with the driven gear 28. A rotor shaft of the second electric motor MG2 is connected to the reduction gear 36, and the second electric motor MG2 is connected to the reduction gear 36 so as to be able to transmit power. The power transmission device 16 includes a pair of drive shafts 38 connected to the differential gear 34, etc.

[0015] The power transmission device 16 configured as described above is suitable for use in FF (front engine, front drive) or RR (rear engine, rear drive) vehicles. The vehicle 10 according to this embodiment is a FF vehicle. The power transmission device 16 transmits power output from the engine 12 to the driven gear 28 via the transmission 24. The power transmission device 16 transmits power output from the second electric motor MG2 to the driven gear 28 via a reduction gear 36. The power transmission device 16 transmits the power transmitted to the driven gear 28 to the pair of drive wheels 14 sequentially via the driven shaft 30, final gear 32, differential gear 34, drive shaft 38, etc. The differential gear 34 is a differential device that distributes the power transmitted via the final gear 32 to the pair of drive wheels 14.

[0016] The power transmission device 16 has a first axis CL1, a second axis CL2, a third axis CL3, and a fourth axis CL4, each of which is a rotation center line. These four axes CL1, CL2, CL3, and CL4 are parallel to one another. The first axis CL1 is the axis of the input shaft 22 and the axis of the rotor shaft of the first electric motor MG1. In other words, the first axis CL1 is the rotation center line of the first electric motor MG1. The transmission unit 24 and the first electric motor MG1 are arranged around the first axis CL1. In other words, the transmission unit 24 has a drive gear 26a arranged coaxially with the first electric motor MG1. The second axis CL2 is the axis of the driven shaft 30. The driven gear 28 and the final gear 32 are arranged around the second axis CL2. In other words, the second axis CL2 is the rotation center line of the driven gear 28, the driven shaft 30, and the final gear 32. The third axis CL3 is the axis of the rotor shaft of the second electric motor MG2. In other words, the third axis CL3 is the rotation center line of the second electric motor MG2. The second electric motor MG2 and the reduction gear 36 are arranged around the third axis CL3. The fourth axis CL4 is the axis of the drive shaft 38 and the axis of the differential gear 34. In other words, the fourth axis CL4 is the rotation center line of the differential gear 34. The differential gear 34 is arranged around the fourth axis CL4.

[0017] The transmission unit 24 includes a first electric motor MG1 and a differential mechanism 40. The differential mechanism 40 is configured as a known single-pinion planetary gear device and includes a sun gear S, a carrier CA, and a ring gear R. The sun gear S is connected to a rotor shaft of the first electric motor MG1, and the first electric motor MG1 is connected to the sun gear S so as to be able to transmit power. The carrier CA is connected to the input shaft 22, and the engine 12 is connected to the input shaft 22 and the like so as to be able to transmit power. The ring gear R is formed on a part of the inner circumferential surface of the compound gear 26, and is connected integrally to the drive gear 26a.

[0018] The differential mechanism 40 is a differential mechanism that generates a differential action and is connected to the engine 12 so that power can be transmitted therethrough. The first electric motor MG1 is a differential motor that is connected to the differential mechanism 40 so that power can be transmitted therethrough. The differential mechanism 40 is a power split mechanism that mechanically splits the power of the engine 12 that is input to the carrier CA between the first electric motor MG1 and the drive gear 26a. The transmission unit 24 is a known electric transmission mechanism in which the differential state of the differential mechanism 40 is controlled by controlling the operating state of the first electric motor MG1. The first electric motor MG1 can also function as a power source that outputs power to the pair of drive wheels 14 via the differential mechanism 40.

[0019] FIG. 2 is a diagram illustrating an example of the electrical configuration of the power control unit 54 and the like.

[0020] The vehicle 10 further includes a high-voltage battery 46 , an auxiliary battery 48 , and a power control unit 54 .

[0021] The high-voltage battery 46 is a rechargeable secondary battery such as a nickel-metal hydride secondary battery or a lithium-ion battery. The high-voltage battery 46 is connected to a power control unit 54. The high-voltage battery 46 is a battery for driving the first electric motor MG1 and the second electric motor MG2. For example, stored electric power is supplied from the high-voltage battery 46 to the second electric motor MG2 via the power control unit 54. The first electric motor MG1 and the second electric motor MG2 generate electric power using the power of the engine 12 and the driven force input from the pair of drive wheels 14, respectively, and the generated electric power is charged into the high-voltage battery 46 via the power control unit 54.

[0022] The auxiliary battery 48 is a chargeable and dischargeable secondary battery such as a lead-acid battery. The auxiliary battery 48 has a lower charging voltage than the high-voltage battery 46. The auxiliary battery 48 is charged by power generated by an alternator driven by the engine 12 and power supplied from the high-voltage battery 46 via a DC-DC converter 56.

[0023] The power control unit 54 includes a DC-DC converter 56, a boost converter 60, an inverter 62, and a motor control device 58. The power control unit 54 is a power control device that controls the power exchanged between the high-voltage battery 46 and the first electric motor MG1 and the second electric motor MG2, i.e., the power exchanged between the first electric motor MG1 and the second electric motor MG2. The power control unit 54 corresponds to the "power control device" in this invention.

[0024] The DC-DC converter 56 is connected to the high-voltage battery 46. The DC-DC converter 56 functions as a charging device that steps down the voltage of the high-voltage battery 46 to a voltage equivalent to that of the auxiliary battery 48 and charges the auxiliary battery 48. The auxiliary battery 48 supplies power to operate the auxiliary devices provided in the vehicle 10. The auxiliary battery 48 supplies power to operate, for example, the engine control device 52 and the electric motor control device 58.

[0025] The boost converter 60 includes a reactor, a switching element, etc. (not shown). The boost converter 60 is a step-up / step-down circuit that has the function of boosting the voltage of the high-voltage battery 46 and supplying it to the inverter 62, and the function of reducing the voltage converted to DC by the inverter 62 and supplying it to the high-voltage battery 46.

[0026] The inverter 62 includes an MG1 power module 64, an MG2 power module 66, etc. The MG1 power module 64 and the MG2 power module 66 each include a switching element (not shown), etc. The inverter 62 converts the DC current output from the boost converter 60 into AC current for driving the first electric motor MG1 and the second electric motor MG2. The inverter 62 converts the AC current generated by the first electric motor MG1 and the AC current generated by the second electric motor MG2 into DC current, respectively. The inverter 62 uses the electric power generated by the first electric motor MG1 as electric power for driving the second electric motor MG2 depending on the running state.

[0027] The electronic control unit 50 transmits and receives signals between the DCDC converter 56, the electric motor control unit 58, and the engine control unit 52, for example, via a known CAN (Controller Area Network) communication line. The electronic control unit 50 controls the running state of the vehicle 10 based on signals from, for example, a sensor (not shown). The electronic control unit 50 controls, for example, the DCDC converter 56 to reduce the voltage of the high-voltage battery 46 to a voltage equivalent to that of the auxiliary battery 48. In this embodiment, the electronic control unit 50 and the engine control unit 52 are each a control unit separate from the power control unit 54, particularly the electric motor control unit 58.

[0028] The motor control device 58 controls the first electric motor MG1 and the second electric motor MG2 based on the output requirement value from the electronic control device 50. For example, the motor control device 58 controls the boost converter 60 and the inverter 62 to control the output of each of the first electric motor MG1 and the second electric motor MG2.

[0029] Returning to FIG. 1, the transaxle 98 is a drive device that includes the power transmission device 16 (such as the transmission unit 24, the compound gear 26, the driven gear 28, the driven shaft 30, and the final gear 32), the first electric motor MG1, and the second electric motor MG2. The drive unit 96 is a unit in which the transaxle 98 and the power control unit 54 are housed and integrated in the same case 18, that is, an electromechanical integrated unit. The meaning of "same case" will be explained later. The transaxle 98 corresponds to the "drive device" in this invention, and the drive unit 96 corresponds to the "electromechanical integrated unit" in this invention.

[0030] FIG. 3 is a diagram illustrating an example of the schematic configuration of the drive unit 96. The up-down direction, front-rear direction, and vehicle width direction shown in FIG. 3 and later-described FIGS. 4 to 8 indicate directions when the drive unit 96 is mounted on the vehicle 10. The "up-down direction" is the direction of a vertical line. The "front-rear direction" is the front-rear direction of the vehicle 10. The "vehicle width direction" is the width direction of the vehicle 10, which is a direction perpendicular and horizontal to the front-rear direction. The drive unit 96 is disposed adjacent to the engine 12.

[0031] The case 18 is made of, for example, an aluminum alloy casting, and includes, for example, a first case portion 70, a second case portion 72, a third case portion 74, and a fourth case portion 76.

[0032] The first case portion 70 is a cylindrical member with a bottom. The second case portion 72 is a cylindrical member with a bottom, and a partition wall 72d is provided inside the second case portion 72. The interior of the second case portion 72 is divided into upper and lower sections in the up-down direction by the partition wall 72d. The first case portion 70 and the second case portion 72 are integrally connected by fasteners such as bolts 78a (see FIG. 1) so that the opening of the first case portion 70 and the engine 12 side of the second case portion 72 are aligned. By connecting the second case portion 72 to the first case portion 70, the case 18 has an upper space U and a lower space L that are separated into upper and lower sections in the up-down direction by the partition wall 72d. The second case portion 72 has an opening in the side wall that defines the lower space L, on the side opposite the engine 12. The second case portion 72 has an opening in the top surface that defines the upper space U. When mounted in the vehicle 10, the power control unit 54 is housed in the upper space U, and the transaxle 98 is housed in the lower space L.

[0033] The upper space U and the lower space L are separated vertically by a partition wall 72d, and the side wall that defines the upper space U and the side wall that defines the lower space L are integrally formed as the second case portion 72, for example, by casting. The partition wall 72d has a common partition wall 72d at the lower side that defines the upper space U and at the upper side that defines the lower space L. Therefore, when the upper space U and the lower space L are separated in the second case portion 72, at least one of the upper space U and the lower space L is necessarily exposed to the outside. The term "same case" means that when the upper space U and the lower space L are separated in this way, at least one of them is exposed to the outside.

[0034] The third case portion 74 is a plate-like member joined to the second case portion 72 so as to close the opening in the side wall of the second case portion 72. The second case portion 72 and the third case portion 74 are integrally connected by a fastener such as a bolt 78b (see FIG. 1).

[0035] The fourth case portion 76 is a plate-like member joined to the second case portion 72 so as to close the opening in the upper surface of the second case portion 72. The second case portion 72 and the fourth case portion 76 are integrally connected by a fastener such as a bolt 78c (see FIG. 1).

[0036] When the transaxle 98 is installed in the vehicle 10, it is disposed such that, for example, the first axis CL1, the second axis CL2, the third axis CL3, and the fourth axis CL4 are aligned in the vehicle width direction. When the transaxle 98 is installed in the vehicle 10, the positions of the first axis CL1, the second axis CL2, the third axis CL3, and the fourth axis CL4 of the transaxle 98 are arranged in the following order from top to bottom in the vertical direction: second electric motor MG2, driven shaft 30, first electric motor MG1, and differential gear 34, and also in the following order from front to rear in the longitudinal direction: first electric motor MG1, driven shaft 30, differential gear 34, and second electric motor MG2. This allows the vertical size of the transaxle 98 to be reduced while ensuring an appropriate inter-axis distance between the first axis CL1, the second axis CL2, the third axis CL3, and the fourth axis CL4.

[0037] In the upper space U, a pair of side walls 72s1 of the second case portion 72 face each other in the front-rear direction. In the upper space U, a pair of side walls 72s2 (see FIG. 4) of the second case portion 72 face each other in the vehicle width direction. Due to the arrangement of the first electric motor MG1 and the second electric motor MG2, the upper space U is deeper on the first electric motor MG1 side than on the second electric motor MG2 side.

[0038] A base plate 72b, which is a plate-like body, is provided in the upper space U. For example, the base plate 72b is connected by bolts (not shown) to protrusions that protrude into the upper space U from the inner wall on the front side of the pair of side walls 72s1 of the second case portion 72 and the partition wall 72d. For example, the base plate 72b has a strength [N / mm 2 ] is made of a highly durable material, steel. "Strength" is the degree to which an object can withstand load.

[0039] Preferably, the base plate 72b functions as a heat sink to facilitate the dissipation of heat generated by the power control unit 54 to the outside of the case 18. For example, a flow path for a coolant (e.g., cooling water) is provided inside the base plate 72b. The coolant is circulated through this flow path by a pump (not shown). For example, in the upper space U, boards on the upper and lower surfaces of the base plate 72b are respectively mounted with components that generate a large amount of heat among the circuit elements that make up the power control unit 54. In the upper space U, components that generate a smaller amount of heat than the components mounted on the boards attached to the base plate 72b are arranged in a space away from the base plate 72b. The base plate 72b corresponds to the "plate" in this invention.

[0040] 4A and 4B are diagrams illustrating an example of a state in which the drive unit 96 is mounted on the vehicle 10, with (a) being a side view from the left side facing the front of the vehicle 10 and (b) being a top view from above the vehicle 10. In Fig. 4B, a part of the second case portion 72 and the base plate 72b are shown in cross section cut along a plane perpendicular to the thickness direction of the base plate 72b.

[0041] The drive unit 96 is housed in an engine compartment 10x together with the engine 12. The engine compartment 10x is the same as the engine room that houses the engine 12.

[0042] The vehicle 10 includes a pair of side members 80 (see FIG. 8). The pair of side members 80 includes a right side member 80R disposed on the right side in the vehicle width direction, and a left side member 80L disposed on the left side in the vehicle width direction. The left side member 80L and the right side member 80R are connected by a cross member (not shown) (for example, a front cross member, a floor cross member, a rear cross member, etc.).

[0043] In the vehicle width direction, the left side of the drive unit 96 is attached to the left side member 80L via a fastening member 82. The fastening member 82 is a member that attaches the drive unit 96 to the left side member 80L. The fastening member 82 is connected to the left side member 80L with fasteners such as a plurality of bolts 92, and is connected to the drive unit 96 with fasteners such as a plurality of bolts 94. The third case portion 74 is provided with a fastening portion 74t. The fastening portion 74t is a portion to which the fastening member 82 is fastened with fasteners. The fastening portion 74t has a plurality of holes in the front-rear direction so that, for example, bolts 94 can be fastened. The fastening portion 74t is thicker than the surrounding portion of the fastening portion 74t, i.e., has a thick wall. Therefore, in the third case portion 74, the fastening portion 74t has higher strength than the surrounding portion of the fastening portion 74t.

[0044] In the vehicle width direction, the right side of the drive unit 96 is attached to the left side of the engine 12 via a fastening member (not shown). In the vehicle width direction, the right side of the engine 12 is attached to the right side member 80R. In this way, the left side member 80L supports the drive unit 96 via a fastening member 82. The left side member 80L corresponds to the "side member" in this invention. The fastening member 82 corresponds to the "fastening member" in this invention.

[0045] In the longitudinal direction, the strength of the left side member 80L gradually decreases from the front to the rear, up to a weak portion 80Lw (described later). For example, in the longitudinal direction, the left side member 80L gradually tapers from the front to the rear, down to a weak portion 80Lw (described later), with the portion where the fastening member 82 is attached being relatively thin. The strength of the left side member 80L is improved by attaching the fastening member 82. Therefore, for example, in the longitudinal direction, a position forward of the portion where the fastening member 82 is attached to the left side member 80L is defined as the weak portion 80Lw of the left side member 80L. Note that this "forward position" corresponds to the "outward position" in this invention. The weak portion 80Lw is the portion of the left side member 80L that is most susceptible to fracture. The weak portion 80Lw is provided so that, in the event of a frontal collision of the vehicle 10, the left side member 80L fractures or bends to absorb the energy of the collision.

[0046] When viewed in the vehicle width direction, the fragile portion 80Lw is positioned so as to overlap the base plate 72b. That is, the fragile portion 80Lw and the base plate 72b have portions that are at the same position in the up-down and down-front directions. In the front-rear direction, the base plate 72b extends to a position rearward of the forward-most position of the fastening portion 74t. As shown in FIG. 4 , the base plate 72b extends rearward of the forward-most position of the fastening portion 74t by a length L1 [mm] in the front-rear direction. Preferably, the base plate 72b is positioned so as to contact both inner walls of the pair of side walls 72s2 in the upper space U. Here, "positioned so as to contact" does not necessarily mean that the base plate 72b is in constant contact with the inner walls. It is sufficient that the base plate 72b is positioned so as to contact both inner walls of the pair of side walls 72s2 before the side wall is damaged when the left side member 80L is bent or broken at the fragile portion 80Lw due to a collision and presses against the left side wall of the second case portion 72. The pair of side walls 72s2 corresponds to the "pair of side walls" in this invention.

[0047] Fig. 5 is a diagram illustrating an example of a state in which the drive unit 96 is attached to the left side member 80L, as viewed from above the vehicle 10. Fig. 6 ...7 is a diagram illustrating an example of a state in which the drive unit 96 is attached to the left side member 80L, as viewed from above the vehicle 10.

[0048] The fastening member 82 includes a mount insulator 84, a mount bracket 86, and a fastener 88. The mount insulator 84 is a well-known insulator that provides thermal insulation, vibration damping, and insulation by blocking out heat, vibration, electricity, etc. The mount bracket 86 is a support member used when mounting the drive unit 96 to the left side member 80L. The mount insulator 84, the mount bracket 86, and the fastener 88 correspond to the "insulator," "bracket," and "fastener" of this invention, respectively.

[0049] For example, the mount insulator 84 includes an insulator portion 84a, a support portion 84b, and an attachment portion 84c. The insulator portion 84a includes, for example, a metallic outer peripheral cylindrical portion and a metallic inner peripheral cylindrical portion arranged on a common axis, and rubber arranged between the outer peripheral cylindrical portion and the inner peripheral cylindrical portion. The support portion 84b supports the outer peripheral cylindrical portion of the insulator portion 84a. The attachment portion 84c is a plate-shaped portion attached to the upper surface of the left side member 80L. The support portion 84b and the attachment portion 84c are formed by bending, for example, after press working.

[0050] The mount bracket 86 is made of, for example, cast steel. The mount bracket 86 has a first mounting portion 86a and a second mounting portion 86b. The first mounting portion 86a is a plate-shaped portion attached to a fastening seat surface 74u, which is the upper surface of the fastening portion 74t of the third case portion 74. The second mounting portion 86b is a portion connected to the insulator portion 84a of the mount insulator 84 via a fastener 88. The mount bracket 86 and the mount insulator 84 are connected by the fastener 88, which is, for example, a through bolt and a nut. Specifically, a through bolt is inserted between a hole provided in the second mounting portion 86b and an inner hole in the inner cylindrical portion of the insulator portion 84a, and is fastened by a nut.

[0051] The mounting portion 84c of the mount insulator 84 is attached to the left side member 80L with a bolt 92. The first mounting portion 86a of the mount bracket 86 is attached to the fastening portion 74t with a bolt 94. The support portion 84b of the mount insulator 84 fixes the outer peripheral cylindrical portion of the insulator portion 84a with a bolt 90 so that the support portion 84b cannot move relative to the insulator portion 84a.

[0052] FIG. 8 is a diagram illustrating a state in which the left side member 80L breaks when the vehicle 10 collides head-on with a collision object 100. While FIG. 8 illustrates an example in which the left side member 80L breaks, the same applies when the left side member 80L is bent. The upper part of FIG. 8 shows the state before the frontal collision, and the lower part of FIG. 8 shows the state immediately after the frontal collision. FIG. 8 illustrates an offset collision in which the collision position with the collision object 100 is 25% of the left side of the front of the vehicle 10, a so-called small overlap frontal collision. The lower part of FIG. 8 shows a cross section of a portion of the second case portion 72 and the base plate 72b cut along a plane perpendicular to the thickness direction of the base plate 72b.

[0053] Due to the frontal collision, the left side member 80L is broken at the weak portion 80Lw. In the longitudinal direction, the left side member 80L is divided into a front side member 80La on the front side and a rear side member 80Lb on the rear side. The broken portion of the divided front side member 80La presses the case 18 (particularly the left side wall of the pair of side walls 72s2 of the second case portion 72) in the direction of the outline arrow D. That is, the broken portion of the front side member 80La presses the case 18 in the vehicle width direction. When the weak portion 80Lw is positioned so as to overlap with the base plate 72b as viewed in the vehicle width direction, as in this embodiment, the strength of the side wall of the second case portion 72 is improved compared to when it is not. That is, the side wall of the second case portion 72 is less likely to break even when subjected to a load from the front side member 80La. The second case portion 72 is less likely to be broken through by the broken front side member 80La.

[0054] According to this embodiment, (a) the case 18 has an upper space U and a lower space L separated vertically within the second case portion 72, (b) the power control unit 54 is housed in the upper space U and the transaxle 98 is housed in the lower space L, (c) a base plate 72b is provided within the upper space U, and (d) the fragile portion 80Lw is disposed in a position overlapping the base plate 72b as viewed in the vehicle width direction. If the left side member 80L is broken at the fragile portion 80Lw due to a frontal collision, the broken left side member 80L will press against the second case portion 72 in the vehicle width direction and attempt to break through it. However, when the fragile portion 80Lw is disposed in a position overlapping the base plate 72b as viewed in the vehicle width direction, the strength of the left side wall of the pair of side walls 72s2 that define the upper space U in the second case portion 72 is improved compared to when the fragile portion 80Lw is not disposed in a position overlapping the base plate 72b as viewed in the vehicle width direction. This prevents the second case portion 72 from being broken through by the broken left side member 80L, thereby preventing the power control unit 54, which is at high voltage due to damage to the second case portion 72, from being exposed to the outside of the case 18, making it easier to ensure safety.

[0055] According to this embodiment, the base plate 72b is disposed in contact with both of the inner walls of the pair of side walls 72s2 of the second case portion 72 that face each other in the vehicle width direction in the upper space U. When the base plate 72b is disposed in contact with both of the inner walls of the pair of side walls 72s2 of the second case portion 72, the strength of the second case portion 72 is improved compared to when this is not the case. This makes it less likely that the second case portion 72 will be broken through by the broken left side member 80L, which prevents the power control unit 54, which is at a high voltage when the second case portion 72 is damaged, from being exposed to the outside of the case 18, making it easier to ensure safety.

[0056] According to this embodiment, the base plate 72b is made of a material having a higher strength than the case 18. When the base plate 72b is made of a material having a higher strength than the case 18, the strength of the second case portion 72 is improved compared to when the base plate 72b is not made of a material having a higher strength than the case 18.

[0057] According to this embodiment, in the front-rear direction, the fragile portion 80Lw is located forward of the portion of the left side member 80L where the fastening member 82 (specifically, the attachment portion 84c of the mount insulator 84) is attached. If the left side member 80L breaks at the fragile portion 80Lw, the drive unit 96 remains supported by the rear side member 80Lb. Furthermore, the side wall of the second case portion 72 that is pressed by the broken front side member 80La is a portion whose strength has been improved by the base plate 72b. Therefore, the power control unit 54 is prevented from being exposed to the outside of the case 18, making it easier to ensure safety.

[0058] According to this embodiment, the strength of the left side member 80L is gradually reduced from the front to the rear in the fore-and-aft direction up to the weakened portion 80Lw, so that the weakened portion 80Lw is located forward of the portion of the left side member 80L where the fastening member 82 is attached.

[0059] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention can also be applied to other embodiments.

[0060] In the above-described embodiment, the vehicle 10 is a hybrid vehicle equipped with the engine 12, the first electric motor MG1, and the second electric motor MG2 as power sources, but the present invention is not limited to this. For example, the present invention can also be applied to a vehicle that does not have the engine 12 as a power source but has only electric motors, i.e., an electric vehicle.

[0061] In the above-described embodiment, the first electric motor MG1 and the second electric motor MG2 are both motor generators, but the present invention is not limited to this. For example, the first electric motor MG1 may be a rotating electric machine that does not have a motor function as long as it has a generator function. For example, the second electric motor MG2 may be a rotating electric machine that does not have a generator function as long as it has a motor function.

[0062] In the above-described embodiment, the transaxle 98 includes two electric motors, the first electric motor MG1 and the second electric motor MG2, but the present invention is not limited to this. The transaxle 98 may include one electric motor, or three or more electric motors. For example, the transaxle 98 may be an electric vehicle that does not include the first electric motor MG1 as a power source and is only provided with the second electric motor MG2.

[0063] In the above-described embodiment, the vehicle 10 is a front-wheel drive vehicle, but the present invention is not limited to this. For example, the present invention can also be applied to a rear-wheel drive vehicle in which the drive unit 96 and the left side member 80L are arranged in the reverse order from the embodiment. In this case, the "rearward position" corresponds to the "outward position" in the present invention. In this case, even if the left side member 80L is bent or broken at the weak portion 80Lw in a rear collision, the power control unit 54 is prevented from being exposed to the outside of the case 18, making it easier to ensure safety.

[0064] In the above-described embodiment, the drive unit 96 is attached to the left side member 80L via the fastening members 82, but the present invention is not limited to this. For example, the present invention is also applicable to an embodiment in which the drive unit 96 is attached to the right side member 80R via the fastening members 82. In this embodiment, the right side member 80R corresponds to the "side member" in the present invention.

[0065] In the above-described embodiment, when the transaxle 98 is installed in the vehicle 10, the positions of the first axis CL1, the second axis CL2, the third axis CL3, and the fourth axis CL4 are arranged in the following order from top to bottom in the vertical direction: second electric motor MG2, driven shaft 30, first electric motor MG1, and differential gear 34, and also in the following order from front to rear in the longitudinal direction: first electric motor MG1, driven shaft 30, differential gear 34, and second electric motor MG2. However, the present invention is not limited to this arrangement. For example, when the transaxle 98 is installed in the vehicle 10, the positions of the first axis CL1, the second axis CL2, the third axis CL3, and the fourth axis CL4 may be arranged in the following order from front to rear in the longitudinal direction: second electric motor MG2, differential gear 34, driven shaft 30, and first electric motor MG1.

[0066] In the above-described embodiment, the base plate 72b is made of a material having a higher strength than the case 18, but the present invention is not limited to this. For example, the base plate 72b may be made of a material having a strength equal to or less than that of the case 18. Even in such an embodiment, if the weak portion 80Lw is arranged at a position overlapping the base plate 72b when viewed in the vehicle width direction, the strength of the second case portion 72 is improved compared to when the weak portion 80Lw is not arranged.

[0067] In the above-described embodiment, the electronic control unit 50, the motor control unit 58 that controls the first electric motor MG1 and the second electric motor MG2, and the engine control unit 52 that controls the engine 12 are each separate control units, but the present invention may be an embodiment in which they are integrated into a single control unit. In the present invention, the electronic control unit 50, the motor control unit 58, and the engine control unit 52 may each be a control unit that is functionally separated, as necessary.

[0068] It should be noted that the above is merely one embodiment, and the present invention can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0069] 10: hybrid vehicle (electric vehicle), 18: case, 54: power control unit (power control device), 72b: base plate (plate), 72d: bulkhead, 72s2: pair of side walls (pair of side walls), 80L: left side member (side member), 80Lw: weak part, 82: fastening member (fastening member), 96: drive unit (mechanical integrated unit), 98: transaxle (drive device), L: lower space, MG1: first electric motor (electric motor), MG2: second electric motor (electric motor), U: upper space

Claims

1. An electric vehicle including an electromechanical integrated unit in which a drive device including an electric motor that functions as a power source and a power control device that controls the power exchanged by the electric motor are housed in the same case, and a side member to which the electromechanical integrated unit is attached via a fastening member, The case has an upper space and a lower space separated into upper and lower spaces therein, the power control device is housed in the upper space and the drive device is housed in the lower space; A plate is provided in the upper space, When viewed in the vehicle width direction, the weak portion of the side member is disposed at a position overlapping with the plate. An electric vehicle characterized by:

2. The plate is disposed in the upper space so as to contact both inner walls of a pair of side walls of the case that face each other in the vehicle width direction.

2. The electric vehicle according to claim 1 .

3. The plate is made of a material stronger than the case.

3. The electric vehicle according to claim 1 or 2.

4. In the front-rear direction of the electric vehicle, the weakened portion is provided at a position outward from a portion of the side member to which the fastening member is attached.

3. The electric vehicle according to claim 1 or 2.

5. In the longitudinal direction of the electric vehicle, the strength of the side members is gradually reduced from the outside to the inside up to the weak portion.

5. The electric vehicle according to claim 4.

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