Electric vehicle front structure

Abstract

To suppress inhibition of energy absorption of a sub frame and input of a large load to a drive motor at the time of front collision.SOLUTION: A front part structure of an electric vehicle comprises: a body side frame 31 which extends in at least a front-back direction, and is located on both sides in a vehicle width direction; a sub frame 34 which is fastened to a lower part of the body side frame, and has a side member 34a extending in the front-back direction; a power unit room 2 formed inside the sub frame; and a motor housing 5a which is arranged in the power unit room, has a side wall part 12 facing the side member, and accommodates a drive motor 5. The motor housing is arranged so that a lower part of the side wall part is adjacent to the side member. An inclined plane part 14, which contacts the side member bent toward the power unit room at the time of vehicle collision and guides the side member down the motor housing is formed below the side wall part.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The technology disclosed herein belongs to the technical field related to the front structure of an electric vehicle. [Background technology]

[0002] In an electric vehicle in which electricity is supplied to a drive motor to drive the vehicle, a structure is known in which a drive motor, a reduction gear, an engine, and a generator are arranged side by side in the vehicle width direction within a power unit room at the front of the vehicle, as shown in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-138718 Summary of the Invention [Problem to be solved by the invention]

[0004] When the drive motor, reduction gear, engine, and generator are arranged side by side in the vehicle width direction in this way, the drive motor is located close to the side of the power unit compartment. Furthermore, if the subframe is located close to the bottom of the drive motor, if the vehicle crashes from the front and the subframe bends inward into the power unit compartment, the bent subframe will come into contact with the side wall of the drive motor, hindering energy absorption by deformation of the subframe and raising concerns about the application of a large load to the drive motor.

[0005] The technology disclosed herein has been developed in consideration of these points, and its purpose is to suppress the inhibition of energy absorption by the subframe during a frontal collision and the input of large loads to the drive motor. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the technology disclosed herein is directed to a front structure of an electric vehicle and includes body side frames extending at least in the longitudinal direction of the vehicle and arranged on both sides in the vehicle width direction, a subframe fastened to a lower part of the body side frames and having side members extending in the longitudinal direction of the vehicle, a power unit room formed inside the subframe, and a motor housing arranged within the power unit room, having side wall portions facing the side members, and accommodating a drive motor that drives the vehicle using electric power, wherein the motor housing is arranged so that a lower part of the side wall portions is adjacent to the side members, and an inclined surface portion is formed below the side wall portion that abuts against the side members that are bent towards the power unit room in the event of a vehicle collision and that guides the side members downwardly of the motor housing.

[0007] With this configuration, the motor housing can guide the side member that bends during a collision downward by sliding it along the inclined surface portion, thereby preventing the subframe from deforming and preventing large loads from being input to the drive motor.

[0008] In one embodiment of the front structure of the electric vehicle, the motor housing is formed by fastening a first housing having the side wall portion and a second housing having a cylindrical peripheral wall portion extending in the vehicle width direction at a flange portion that protrudes radially outward from the peripheral wall portion, and the inclined surface portion is formed from the edge end of the side wall portion to the edge end of the flange portion.

[0009] With this configuration, an inclined surface portion is formed from the side wall portion to the flange portion, which prevents the side member that bends during a collision from getting caught on the flange portion and hindering energy absorption due to deformation of the subframe.

[0010] The technology disclosed herein is directed to a front structure of an electric vehicle, and includes body side frames extending at least in the longitudinal direction of the vehicle and arranged on both sides in the vehicle width direction, a subframe fastened to a lower portion of the body side frames and having side members extending in the longitudinal direction of the vehicle, a power unit room formed inside the subframe, and a motor housing arranged in the power unit room, having side wall portions facing the side members, and accommodating a drive motor that drives the vehicle using electric power, wherein the motor housing is arranged so that a lower portion of the side wall portions is adjacent to the side members, and below the side wall portions, an inclined surface portion is formed that comes into contact with the side members that are bent toward the power unit room in the event of a vehicle collision and that guides the side members downwardly of the motor housing, The inclined surface portion is formed so as to overlap with the side member in a side view of the vehicle. and .

[0011] According to this configuration, The motor housing can guide the side members that are bent during a collision downward while sliding them along the inclined surface, thereby suppressing the obstruction of energy absorption due to deformation of the subframe and the input of a large load to the drive motor. The inclined surface portion can be provided at a position where the side member is likely to come into contact when bent during a collision, thereby reducing the increase in weight due to the formation of the inclined surface portion.

[0012] In one embodiment, when viewed from the side of the vehicle, the side member extends approximately horizontally rearward of the vehicle's longitudinal center of the motor housing, and extends upward forward forward of the vehicle's longitudinal center of the motor housing, and the inclined surface portion may be formed forward of the vehicle's longitudinal center of the motor housing.

[0013] This configuration allows the inclined surface portions to be provided in positions where the bent side members are more likely to come into contact during a collision, thereby efficiently suppressing the impairment of energy absorption due to deformation of the subframe and the input of large loads to the drive motor, and reducing the weight increase due to the formation of the inclined surface portions. [Effects of the Invention]

[0014] As described above, the technology disclosed herein can suppress the inhibition of energy absorption by the subframe during a frontal collision and the input of a large load to the drive motor. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a block diagram illustrating a drive train of an electric vehicle having a front structure according to an exemplary embodiment. [Figure 2] FIG. [Figure 3] FIG. 10 is a perspective view of the front structure as seen from the lower right side. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 7 is an enlarged view of a main part of FIG. 6. [Figure 8] 8 is a schematic cross-sectional view of a main part taken along a plane corresponding to line VIII-VIII in FIG. 7. DETAILED DESCRIPTION OF THE INVENTION

[0016] Exemplary embodiments will be described in detail below with reference to the drawings. In the following description, the longitudinal direction of the vehicle will be simply referred to as the "longitudinal direction," the front side of the vehicle will be simply referred to as the "front side," and the rear side of the vehicle will be simply referred to as the "rear side." The vehicle width direction is the left-right direction of the vehicle, and the left side of the vehicle will be simply referred to as the "left side," and the right side of the vehicle will be simply referred to as the "right side." Note that, in the lateral direction, the left side when viewed from the rear side to the front side will be referred to as the left, and the right side will be referred to as the right.

[0017] Fig. 1 is a block diagram showing a drive train of an electric vehicle equipped with a front structure according to an exemplary embodiment. Fig. 2 is a plan view schematically showing the front structure. Figs. 1 and 2 only show a schematic view of the drive train of the vehicle 1, and the arrangement of each component does not limit the actual arrangement of the components.

[0018] Vehicle 1 is a series hybrid vehicle. Vehicle 1 is equipped with a power unit P consisting of an electric drive unit 10 for driving vehicle 1 using electric power and an engine body 8 for generating electricity. Electric drive unit 10 has a drive motor 5 that drives the vehicle using electric power, a reduction gear 6 that reduces the power from drive motor 5 and outputs it, and a generator 7 that generates electric power to be supplied to drive motor 5.

[0019] The engine E has an engine body 8 and engine-related components. The engine body 8 is mainly used to drive a generator 7 to generate electricity, and the power for propelling the vehicle 1 is generated by a drive motor 5. The power generated by the drive motor 5 is changed in speed by a reducer 6 and then transmitted to drive wheels 92 (here, the front wheels) via a differential device 91.

[0020] The vehicle 1 includes a high-voltage battery B1 and a low-voltage battery B2. The high-voltage battery B1 is charged with electricity generated by a generator 7. A power generation inverter 102 is provided between the generator 7 and the high-voltage battery B1. The power generation inverter 102 is electrically connected to the generator 7 and the high-voltage battery B1. Electricity generated by the generator 7 is supplied to the high-voltage battery B1 via the power generation inverter 102. A motor inverter 101 is provided between the drive motor 5 and the high-voltage battery B1. The motor inverter 101 is electrically connected to the drive motor 5 and the high-voltage battery B1. The motor inverter 101 converts electricity from the high-voltage battery B1 into power for driving the drive motor 5 and outputs the power to the drive motor 5. A DC-DC converter 103 is provided between the high-voltage battery B1 and the low-voltage battery B2. The DC-DC converter 103 is electrically connected to the high-voltage battery B1 and the low-voltage battery B2. Electricity from the high-voltage battery B1 is supplied to the low-voltage battery B2 via the DC-DC converter 103. The electricity generated by the generator 7 is supplied to the low-voltage battery B2 via a power generation inverter 102 and a DC-DC converter 103.

[0021] The power unit P includes a drive motor 5, a reduction gear 6, a generator 7, and an engine body 8, arranged in this order in the vehicle width direction. Above the drive motor 5, the reduction gear 6, and the generator 7, a power conversion unit 100 including a motor inverter 101, a power generation inverter 102, and a DC-DC converter 103 is disposed.

[0022] The drive motor 5, the reducer 6, and the generator 7 are housed in a drive unit housing 9. The rotational shafts (not shown) of the drive motor 5, the reducer 6, and the generator arranged in the drive unit housing 9 extend in the vehicle width direction, and the drive unit housing 9 is formed in a substantially cylindrical shape extending in a direction substantially parallel to the rotational shafts.

[0023] The drive unit housing 9 is made up of multiple integrated members. Within the drive unit housing 9, the portion that houses the drive motor 5 is called the motor housing 5a. The motor housing 5a is located at one end of the drive motor 5 in the vehicle width direction.

[0024] The engine body 8 is disposed adjacent to the generator 7 and is located at the other end in the vehicle width direction. The engine body 8 is configured integrally with a drive unit housing 9. The engine E is configured from the engine body 8 and engine-related parts. The engine-related parts include a low-voltage battery B2, an air cleaner 106, and oil-related parts 107, which are disposed above the engine body 8.

[0025] The vehicle 1 has, at its front, a pair of left and right body side frames 31 that extend at least in the longitudinal direction and are arranged on both sides in the vehicle width direction. Subframes 34, each having side members 34a that extend in the longitudinal direction, are fastened to the lower parts of the body side frames 31. The power unit room 2 is formed inside the body side frames 31 and the subframes 34.

[0026] Fig. 3 is a perspective view of the front structure of the vehicle 1 as seen from the lower right side, and Fig. 4 is a front view of the front structure of the vehicle 1. As shown in Figs. 3 and 4, the body side frame 31 is configured to absorb impact transmitted via a crash can 33 from a bumper reinforcement 32 formed to extend in the vehicle width direction at the front end of the vehicle. The body side frame 31 is formed to have a closed cross-sectional shape with a substantially rectangular vertical cross section in the vehicle width direction. The body side frame 31 and the bumper reinforcement 32 are formed below the power conversion unit 100 and above the drive unit housing 9 so as to surround the outer periphery of the power unit room 2.

[0027] The subframe 34 is composed of side members 34a extending in the front-rear direction on both sides in the vehicle width direction, a rear cross member 34b formed to connect the left and right side members 34a, 34a at the rear ends of the side members 34a, and a front cross member 34c formed to connect the left and right side members 34a, 34a at the front ends of the left and right side members 34a, 34a. The side members 34a are also formed to have a substantially rectangular closed cross section in the vehicle width direction. The subframe 34 is formed below the drive unit housing 9 so as to surround the outer periphery of the power unit room 2.

[0028] A connecting member 35 stands upright at the front end of the side member 34a. The subframe 34 is connected to the body side frame 31 located above by the connecting member 35. An extension portion 38 is formed at the rear of the connecting member 35, on the outer side of the side member 34a in the vehicle width direction, as a collision countermeasure.

[0029] The extension portion 38 is provided at the front of the side member 34a, and the surface on the outer side in the vehicle width direction is inclined from the side surface of the side member 34a toward the front side, and is formed so as to extend entirely.

[0030] Lower crash cans 36 extending forward are provided at the front ends of the side members 34a. The lower crash cans 36 are provided at their front ends with lower bumper reinforcements 37. The lower bumper reinforcements 37 connect the left and right lower crash cans 36 in the vehicle width direction.

[0031] The side member 34a is configured to absorb the impact transmitted from the lower bumper reinforcement 37 via the lower crash can 36. The front end of the lower bumper reinforcement 37 is located forward of the bumper reinforcement 32.

[0032] The power unit P is disposed in a power unit room 2 formed by the body side frames 31 and the subframe 34. The power unit P is supported between the left and right body side frames 31, 31 via support members 39 provided on the body side frames 31.

[0033] Fig. 5 is a perspective view of the motor housing 5a, and Fig. 6 is a side view of the power unit room 2 as viewed from the right side. As shown in Fig. 5, the motor housing 5a is configured by connecting a first housing 11 having a circular side wall portion 12 and a second housing 21 having a cylindrical peripheral wall portion 22. The first housing 11 is disposed so that the lower part of the side wall portion 12 is adjacent to the side member 34a, and an inclined surface portion 14 is formed below the side wall portion 12. The inclined surface portion 14 comes into contact with the side member 34a that is bent toward the power unit room 2 in the event of a vehicle collision, and guides the side member 34a downward in the motor housing 5a.

[0034] Specifically, the first housing 11 is located at the outermost position in the vehicle width direction among the drive unit housing 9, and is adjacent to the right body side frame 31 and side member 34a. The first housing 11 has a substantially circular side wall portion 12 facing the body side frame 31 and side member 34a, and a cylindrical peripheral wall portion 13 extending in the vehicle width direction from the edge of the side wall portion 12.

[0035] The side wall portion 12 stands upright and spaced apart in the vehicle width direction from the body side frame 31 and the side member 34a. A flange portion 13a is formed circumferentially at the end of the peripheral wall portion 13 in the vehicle width direction, protruding radially outward from the peripheral wall portion 13. An inclined surface portion 14 is formed on the peripheral wall portion 13 from the edge of the side wall portion 12 to the edge of the flange portion 13a.

[0036] The second housing 21 has a cylindrical peripheral wall 22 that is connected to the peripheral wall 13 of the first housing 11 and extends in the vehicle width direction. The cylindrical interior of the peripheral wall 22 is partitioned in the vehicle width direction by partition walls 23 (see FIG. 8). In addition, a flange 22a that projects radially outward from the peripheral wall 22 is formed in the circumferential direction at the end of the peripheral wall 22 in the vehicle width direction.

[0037] The motor housing 5a is integrally formed by fastening the first housing 11 and the second housing 21 together at flange portions 13a, 22a that connect to each other with a plurality of bolts that are inserted in the vehicle width direction.

[0038] Fig. 7 is an enlarged view of a main portion of Fig. 6. As shown in Fig. 6 and Fig. 7, in a side view of the vehicle, the body side frame 31 extends substantially horizontally in the front-rear direction so as to overlap an upper portion of the side wall portion 12 of the first housing 11 above the center thereof. In addition, the side member 34a extends in the front-rear direction below the side wall portion 12 of the first housing 11.

[0039] Specifically, in a side view of the vehicle, the side member 34a has a horizontal portion 34d that extends approximately horizontally in the front-to-rear direction and is rearward of the center of the motor housing 5a in the front-to-rear direction. The side member 34a has an inclined portion 34e that extends diagonally upward toward the front and forward of the center of the motor housing 5a in front of the horizontal portion 34d. An extension portion 38 is formed in front of the inclined portion 34e. The side member 34a configured in this manner bends toward the inside of the power unit compartment 2 at the inclined portion 34e behind the extension portion 38 in the event of a frontal collision of the vehicle 1.

[0040] The inclined surface portion 14 is formed forward of the longitudinal center of the motor housing 5a in a side view of the vehicle and so as to overlap with the inclined portion 34e of the side member 34a. The inclined surface portion 14 does not need to be formed over the entire peripheral wall portion 13, and by forming it partially at a position that overlaps with the inclined portion 34e of the side member 34a, it is possible to reduce the increase in weight of the motor housing 5a due to the provision of the inclined surface portion 14.

[0041] Next, with reference to FIG. 8, the function of the inclined surface portion 14 in the event of a frontal collision of the vehicle 1 will be described in detail.

[0042] 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7, but the drive motor 5, the reducer 6, and the generator 7 disposed in the drive unit housing 9 are simplified or omitted. In the present disclosure, the drive motor 5 is disposed on the right side of the partition wall 23 in a chamber formed by the side wall portion 12 and the peripheral wall portion 13 of the first housing 11 and the peripheral wall portion 22 of the second housing 21.

[0043] A third housing 30 is formed on the left side of the second housing 21, and the first housing 11, the second housing 21, and the third housing 30 are integrally configured to form the drive unit housing 9. Although the reducer and the generator are not shown in Fig. 8, the reducer is disposed in a reducer housing section 6a formed by the peripheral wall portion 22 of the second housing 21 and the third housing 30 on the left side of the partition wall 23, and the generator is disposed in a generator housing section 7a formed by the third housing 30 and located on the left side of the reducer housing section 6a.

[0044] When viewed cross-sectionally in the vehicle width direction in this manner, the inclined surface portion 14 is formed from the lower end of the side wall portion 12 of the first housing 11 to the lower end of the flange portion 13a, and is formed in an inclined shape that slopes downward as it moves toward the left, that is, toward the inside of the power unit room 2.

[0045] When the vehicle 1 is hit from the front, the load acting on the lower bumper reinforcement 37 due to the impact crushes the lower crash can 36 and is transmitted to the rearward extending portion 38 and side member 34a. The extending portion 38 encourages the side member 34a to bend and deform, and the side member 34a absorbs the impact by bending toward the inside of the power unit compartment 2 under the load. At this time, the inclined portion 34e of the side member 34a bends and moves to the left, where the inclined surface portion 14 is located.

[0046] As indicated by the arrows and two-dot chain lines in FIG. 8 , the bent inclined portion 34e first contacts the inclined surface portion 14 and then slides along the surface of the inclined surface portion 14, moving downwardly of the motor housing 5a. The inclined surface portion 14 allows the side member 34a to move smoothly toward the inside of the power unit compartment 2 without getting caught on the flange portions 13a and 22a that connect the first housing 11 and the second housing 21. The side member 34a deforms and moves in this manner, thereby dissipating the load caused by the impact. The inclined surface portion 14 guides the side member 34a, thereby preventing the subframe 34 from deforming and thereby preventing energy absorption from being hindered and preventing a large load from being input to the drive motor 5.

[0047] The above-described embodiments are merely examples and should not be construed as limiting the scope of the present disclosure. The scope of the present disclosure is defined by the claims, and all modifications and variations that fall within the scope of the claims equivalents are within the scope of the present disclosure. [Industrial Applicability]

[0048] As described above, the techniques disclosed herein are useful as a front structure for an electric vehicle for suppressing input of a large load to a drive motor during a frontal collision, for example. [Explanation of symbols]

[0049] 1 vehicle 2 Power unit room 5 Drive motor 5a Motor housing 6 Reducer 7. Generator 8 Engine body 9 Drive unit housing 11 First Housing 12 Side wall 13 Peripheral wall section 13a Flange 14 Slope section 21 Second Housing 22 Peripheral wall section 22a Flange 31 Body side frame 34 Subframe 34a Side member E-Engine P Power Unit

Claims

1. A front structure of an electric vehicle, Body side frames extending at least in the vehicle front-rear direction and disposed on both sides in the vehicle width direction; a subframe having a side member fastened to a lower portion of the body side frame and extending in the front-rear direction of the vehicle; a power unit room formed inside the subframe; a motor housing that is disposed within the power unit room, has a side wall that faces the side member, and accommodates a drive motor that drives the vehicle using electric power, the motor housing is formed by fastening a first housing having the side wall portion and a second housing having a cylindrical peripheral wall portion extending in the vehicle width direction at a flange portion that projects radially outward from the peripheral wall portion, a lower portion of the side wall portion is disposed adjacent to the side member, and an inclined surface portion is formed below the side wall portion to come into contact with the side member that is bent toward the power unit room in the event of a vehicle collision and to guide the side member downwardly from the motor housing, The front structure of an electric vehicle, wherein the inclined surface portion is formed from an edge of the side wall portion to an edge of the flange portion.

2. A front structure of an electric vehicle, Body side frames extending at least in the vehicle front-rear direction and disposed on both sides in the vehicle width direction; a subframe having a side member fastened to a lower portion of the body side frame and extending in the front-rear direction of the vehicle; a power unit room formed inside the subframe; a motor housing that is disposed within the power unit room, has a side wall that faces the side member, and accommodates a drive motor that drives the vehicle using electric power, the motor housing is disposed such that a lower portion of the side wall portion is adjacent to the side member, and an inclined surface portion is formed below the side wall portion to come into contact with the side member bent toward the power unit compartment in the event of a vehicle collision and to guide the side member downwardly from the motor housing; the inclined surface portion is formed so as to overlap with the side member in a vehicle side view, a side member extending substantially horizontally rearward of a vehicle longitudinal center of the motor housing, a side member extending upwardly forward of a vehicle longitudinal center of the motor housing, and an inclined surface portion formed forward of the vehicle longitudinal center of the motor housing.

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