Electric vehicle drive unit

Abstract

An electric vehicle comprising: a driving unit including a rotating electrical machine arranged in a motor room of the electric vehicle and an inverter unit electrically connected to the rotating electrical machine; and a mount bracket that supports the driving unit in the motor room. The rotating electrical machine comprises a motor housing. The inverter unit is placed on an upper face of the motor housing and fixed to the motor housing at a fixing point provided on an outer peripheral portion of the inverter unit. The motor housing comprises an upright wall that is upright above the motor housing, on an outer side of the fixing point of the inverter unit in the vehicle width direction. An end of the mount bracket is fixed to an upper portion of the upright wall.

Description

[Technical Field]

[0001] The present invention relates to a drive unit for an electric vehicle. [Background technology]

[0002] In an electric vehicle, an inverter device converts DC power from a battery into AC power and supplies it to a drive motor, which drives the drive motor to travel.

[0003] JP2019-188884A discloses a configuration in which a drive unit, in which a traveling motor (drive motor) and an inverter are integrated, is attached to a side member and an under member via mounts. Summary of the Invention [Problem to be solved by the invention]

[0004] In such an electric vehicle, if a large load is input from the front of the vehicle during a collision, the side members may deform and interfere with the inverter unit, potentially causing problems with insulation. The technology described in the above-mentioned patent documents discloses distributing the load to the side members and under members during an offset collision, but does not disclose any measures to deal with the case where the side members deform and interfere with the inverter unit.

[0005] In view of the above problems, the present invention aims to provide a drive unit for an electric vehicle that can prevent problems from occurring in the insulation of the inverter unit even when a large load is input. [Means for solving the problem]

[0006] According to one embodiment of the present invention, the present invention is applied to a drive unit of an electric vehicle. The drive unit includes a rotating electric machine arranged in a motor compartment of the electric vehicle, an inverter unit electrically connected to the rotating electric machine, and a mount bracket supporting the drive unit in the motor compartment. The rotating electric machine includes a motor housing, and the inverter unit is placed on an upper surface of the motor housing and fixed to the motor housing at a fixing point located on the outer edge of the inverter unit. The motor housing includes an upright wall that stands above the motor housing, outside the fixing point of the inverter unit in the vehicle width direction, and one end of the mount bracket is fixed to the upper surface of the upright wall. [Effects of the Invention]

[0007] According to the present invention, a vertical wall is provided on the outside of the fixing point of the inverter unit in the vehicle width direction, and a mounting bracket is provided on the upper part of this vertical wall. This prevents the components in the motor room fastened to the mounting bracket on the outside of the drive unit from directly interfering with the inverter unit from the outside in the vehicle width direction when a large load is input, such as during a collision, and suppresses problems with the insulation of the inverter unit. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a top view of a motor room of an electric vehicle according to this embodiment. [Figure 2] FIG. 2 is a view of the drive unit as seen from the front of the electric vehicle. [Figure 3] FIG. 3 is an explanatory diagram focusing on the mount bracket. [Figure 4] FIG. 4 is a perspective view focusing on the mount bracket. [Figure 5] FIG. 5 is a view of the motor room as seen from the left side. [Figure 6] FIG. 6 is a view of the drive unit as seen from the left side. [Figure 7] FIG. 7 is a cross-sectional view of the drive unit. DETAILED DESCRIPTION OF THE INVENTION

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

[0010] Fig. 1 is an explanatory diagram of a drive unit 10 of an electric vehicle 1 according to this embodiment, and is a diagram of a motor room 2 of the electric vehicle 1 as viewed from above the electric vehicle 1. Fig. 2 is a diagram of the motor room 2 in which the drive unit 10 is arranged as viewed from the front. In the following description, "right" and "left" refer to the left and right in the vehicle width direction when the vehicle is moving forward.

[0011] As shown in Fig. 1, the drive unit 10 is mounted in a motor room 2 of an electric vehicle 1 and is supported within the motor room 2 by mount brackets 10a, 10b arranged on the left and right sides of the drive unit 10. The drive unit 10 includes a first rotating electric machine 12, a transmission 13, an inverter unit 14, an engine 15, and a second rotating electric machine 16. The drive unit 10 is, for example, a drive device for a series hybrid vehicle.

[0012] 2, in the drive unit 10, the transmission 13 is sandwiched between the engine 15 and the first rotating electric machine 12, the inverter unit 14 is disposed above the first rotating electric machine 12, and the second rotating electric machine 16 is disposed on the vehicle rear side of the first rotating electric machine 12 and fixed to the transmission 13. The drive unit 10 is configured as an integrated unit of these components.

[0013] The first rotating electric machine 12 is electrically connected to the inverter unit 14, and functions as a generator that is driven by the driving force of the engine 15 to generate electricity and output the generated electricity to the inverter unit 14. The first rotating electric machine 12 also functions as a motor that is driven by the electricity supplied from the inverter unit 14. The first rotating electric machine 12 is configured by housing a stator 122 and a rotor 123 in a motor housing 120, as will be described later with reference to FIG. 7 .

[0014] 1, inverter unit 14 converts DC power supplied from a battery (not shown) into AC power suitable for driving first rotating electric machine 12 and supplies it to first rotating electric machine 12. Inverter unit 14 converts power generated by first rotating electric machine 12 into DC power suitable for charging the battery, and charges the battery. As will be described later in FIG. 7, inverter unit 14 is configured by accommodating high-voltage components 142 such as a power module in inverter housing 141.

[0015] The engine 15 drives the first rotating electric machine 12 via the transmission 13, causing the first rotating electric machine 12 to generate electricity. The transmission 13 is, for example, a speed-up gear, and increases the rotation of the engine 15 and transmits it to the first rotating electric machine 12.

[0016] The second rotating electric machine 16 is electrically connected to the inverter unit 14, and functions as a motor when driven by AC power supplied from the inverter unit 14. An axle and drive wheels are connected to the second rotating electric machine 16, and the electric vehicle 1 runs when the second rotating electric machine 16 is driven. The second rotating electric machine 16 also functions as a generator that generates (regenerates) electricity when the vehicle decelerates, and outputs the generated electricity to the inverter unit 14.

[0017] A pair of left and right side members 6 (6a, 6b) are arranged across the front and rear direction in the motor room 2. The drive unit 10 is arranged between the side members 6a, 6b and is supported by the side members 6a, 6b via mount brackets 10a, 10b arranged on the left and right sides thereof.

[0018] An inverter unit 14 is placed on the upper surface of the first rotating electric machine 12 of the drive unit 10. The inverter unit 14 has a plurality of fixing points 14a on the outer edge of an inverter housing 141, and is fixed to the motor housing 120 of the first rotating electric machine 12 at the fixing points 14a via fastening members such as bolts.

[0019] An upright wall 121 having an upwardly standing structure is formed on the upper surface of the motor housing 120, outside in the vehicle width direction (to the left of the inverter unit 14) of the fixing point 14a of the outer edge of the inverter unit 14. The mounting bracket 10a is fastened to the upright wall 121.

[0020] Next, the mounting structure of the drive unit 10 in the motor room 2 will be described.

[0021] Fig. 3 is an explanatory diagram focusing on the mount bracket 10a in Fig. 1. Fig. 4 is a perspective view focusing on the mount bracket 10a.

[0022] 3, one end (upper end) of the mount bracket 10a is fastened to an upper surface 121a of an upright wall 121 formed on the motor housing 120 of the first rotating electric machine 12 of the drive unit 10. The other end (lower end) of the mount bracket 10a is fastened to the upper surface of the side member 6a.

[0023] As shown in FIG. 4, the mount bracket 10a is configured by sandwiching a cylindrical elastic body 101, with a drive unit side bracket 111 fixed to the drive unit 10 side on the upper side thereof and a vehicle body side bracket 112 fixed to the side member 6a side on the lower side thereof.

[0024] The drive unit side bracket 111 supports the elastic body 101 inside, and has three bolt holes formed on the drive unit 10 side for fastening to the standing wall 121. These bolt holes are fastened to the standing wall 121 with bolts to form first fastening points (fastening points 111a, 111b, 111c).

[0025] Vehicle body side bracket 112 is formed in a roughly triangular shape in plan view as shown in FIG. 3 so as to support elastic body 101 on its upper surface, with bolt holes formed at each of the three vertices of the triangle. The front and rear bolt holes in the vehicle longitudinal direction are fastened to side member 6a by bolting. The middle bolt hole between the front and rear sides is at a higher position than the front and rear bolt holes and is fastened to a bracket extending from side member 6a by bolting. The bolt holes of vehicle body side bracket 112 are fastened to side member 6a by bolting, thereby forming second fastening points (fastening points 112a, 112b, 112c).

[0026] The mounting bracket 10a has an elastic body 101 interposed between the drive unit side bracket 111 at the upper end and the vehicle body side bracket 112 at the lower end, thereby suppressing the transmission of vibration between the drive unit 10 and the side member 6a of the motor room 2.

[0027] As shown in Fig. 1, a mount bracket 10b is provided between the engine 15 and the side member 6b. Like the mount bracket 10a, the mount bracket 10b has an elastic body, and supports the engine 15 to the side member 6b of the motor room 2 while suppressing the transmission of vibrations therebetween. In addition, a torque rod (not shown) is provided below the drive unit 10 near the center in the vehicle width direction. The torque rod supports the drive unit 10 in the motor room 2 while suppressing the reaction force caused by the drive torque of the drive unit 10.

[0028] Next, a case where a large load is input to the vehicle, such as during a vehicle collision, in the drive unit 10 configured as above will be described.

[0029] When a large load is applied from the front of the vehicle, such as during a collision, the side members may deform and interfere with the inverter unit, which could damage the inverter housing and cause problems with the inverter unit's insulation.

[0030] In order to prevent such problems, in this embodiment, the following configuration is used to prevent problems from occurring in the insulation of an inverter unit having high-voltage components even when a large load is input.

[0031] 4, in the motor room 2, a side member 6a is located on the left side of the drive unit 10 in the vehicle width direction. An upright wall 121 is disposed adjacent to (facing) the side member 6a at the upper left side in the vehicle width direction of the first rotating electric machine 12. The upright wall 121 functions as a member for attaching a mount bracket 10a, which is a mount member for supporting the drive unit 10 in the motor room 2, and also functions as a member for preventing the deformed side member 6a from interfering with the inverter unit 14 when the side member 6a is deformed, as will be described next.

[0032] 3, an upright wall 121 is interposed between the inverter unit 14, which is disposed on the upper surface of the drive unit 10, and the side member 6a, which is located on the outer side of the inverter unit 14 in the vehicle width direction. The upright wall 121 is formed integrally with the motor housing 120, which is a highly rigid structure for holding the heavy stator 122 and rotor 123. Therefore, even if a large load is input during a collision or the like and the side member 6a is deformed toward the drive unit 10, the presence of the highly rigid upright wall 121 prevents the side member 6a from interfering with the inverter unit 14.

[0033] Since the transmission 13 and engine 15, which are large in rigidity and size, are located on the right side of the inverter unit 14, the components of the motor room 2 do not interfere with the inverter unit 14 from the right side.

[0034] Next, the mounting structure of the drive unit 10 will be described.

[0035] Fig. 5 is a view of the motor room 2 as seen from the left side of the electric vehicle 1. Fig. 6 is a view of the drive unit 10 as seen from the left side of the electric vehicle 1.

[0036] As shown in FIG. 5, a side member 6a is located outside the drive unit 10 (on the front side in FIG. 5), and the left side surface of the first rotating electrical machine 12 of the drive unit 10 faces the side member 6a.

[0037] A bracket 61 having a wave shape in the vertical direction is fixed to the upper surface of the side member 6a. A vehicle body side bracket 112 of the mounting bracket 10a is fastened to the upper surface of the bracket 61 at two fastening points 112a and 112c on the front and rear sides. Fastening point 112b is fastened at a position spaced above the upper surface of the side member 6a, as shown in FIG. 4.

[0038] 6, the drive unit side bracket 111 of the mount bracket 10a is fastened to the upright wall 121 of the first rotating electric machine 12 at three fastening points 111a, 111b, and 111c. The upper surface 121a of the upright wall 121 is positioned higher than the upper surface of the side member 6a.

[0039] In this way, by positioning the upper surface 121a of the standing wall 121 at a position higher than the upper surface of the side member 6a, even if a large load is input and the side member 6a deforms toward the drive unit 10, the side member 6a will not climb over and interfere with the inverter unit 14, which is located further back than the standing wall 121.

[0040] Next, the internal structure of the inverter unit 14 will be described.

[0041] FIG. 7 is a cross-sectional view of the drive unit 10 taken along line VII-VII in FIG.

[0042] The inverter unit 14 is configured to include an inverter housing 141 and a high-voltage component 142 such as a power module. The inverter housing 141 has a box-like shape with an open bottom. The high-voltage component 142 is fixed inside the inverter housing 141, and a part of it protrudes downward from the bottom.

[0043] The high-power component 142 further includes a three-phase bus bar 143 extending downward. The three-phase bus bar 143 electrically connects the first rotating electrical machine 12 and the high-power component 142 together.

[0044] The first rotating electric machine 12 is configured by accommodating a stator 122 and a rotor 123 in a motor housing 120. The stator 122 has windings, and three-phase bus bars 143 are connected to the windings. A recess 125 is formed in the upper surface of the motor housing 120 so as to be recessed downward. The recess 125 faces the bottom of an inverter housing 141 of the inverter unit 14, and accommodates high-voltage components 142 and three-phase bus bars 143 that protrude from the lower side of the inverter housing 141.

[0045] With this configuration, the inverter unit 14 accommodates the high-voltage components 142 and the three-phase bus bar 143 in the space surrounded by the inverter housing 141 and the recess 125 of the motor housing 120. The three-phase bus bar 143 is disposed below the fastening position between the mount bracket 10a and the standing wall 121, i.e., below the upper surface 121a of the standing wall 121.

[0046] More specifically, when the three-phase bus bar 143 and the motor housing 120 are viewed from the left side of the vehicle, the position where they overlap in the vehicle width direction (indicated by A in FIG. 7) and the position where the three-phase bus bar 143 and the side member 6a are viewed from the left side of the vehicle (indicated by B in FIG. 7) overlap in the vehicle width direction.

[0047] The motor housing 120 is a highly rigid structure that supports the heavy stator 122 and rotor 123. Therefore, the highly rigid motor housing 120 is located around the three-phase bus bar 143 and the high-voltage components 142, to which a high voltage is applied. Therefore, even if a large load is input and the side member 6a is deformed toward the drive unit 10, the side member 6a is prevented from interfering with the three-phase bus bar 143 and the high-voltage components 142. Furthermore, the inverter unit 14 accommodates the high-voltage components 142 and the three-phase bus bar 143 in the recess 125 of the motor housing 120 below the inverter housing 141, thereby reducing the size of the inverter unit 14 in the height direction and making the inverter unit 14 more compact.

[0048] Also, as shown in Figure 3, in the mount bracket 10a, the front-to-rear distance between the front fastening point 112a and the rear fastening point 112c of the vehicle body side bracket 112 is configured to be larger than the distance between the front fastening point 111a and the rear fastening point 111c of the drive unit side bracket 111.

[0049] In this way, by increasing the front-to-rear width of the fastening points that fasten mount bracket 10a to side member 6a, even when a large load is applied, side member 6a is less likely to bend toward the drive unit between fastening points 112a and 112c, and will bend at another location. In other words, even when a large load is applied, interference of side member 6a toward drive unit 10 is more reliably prevented.

[0050] 4, the position at which the vehicle body side bracket 112 and the side member 6a are fastened is lower than the position at which the drive unit side bracket 111 is fastened to the upright wall 121. At least one fastening point 112a of the vehicle body side bracket 112 is positioned so as to be located further forward in the vehicle longitudinal direction than the front fastening point 111a of the drive unit side bracket 111. Also, fastening points 112a and 112c between the mount bracket 10a and the side member 6a are positioned lower, and fastening point 112b is positioned higher than these.

[0051] With this configuration, when a large load is input and the side member 6a deforms, at least one of the second fastening points (fastening points 112a, 112b, 112c) is located further forward in the vehicle than the first fastening points (fastening points 111a, 111b, 111c). This causes the second fastening point 112a to break before the first fastening point, allowing the mount bracket 10a to move relative to the side member 6a. At this time, because the drive unit 10 and the mount bracket 10a are fixed at the first fastening point, the mount bracket 10a moves as if pulled diagonally upward and rearward in the motor room 2. Therefore, the drive unit 10 moves in a direction away from the deforming side member 6a, more reliably preventing the side member 6a from interfering with the inverter unit 14 of the drive unit 10. Furthermore, by moving mount bracket 10a so as to be pulled diagonally upward and rearward in motor room 2, even if the first fastening point breaks, mount bracket 10a is prevented from interfering with inverter unit 14.

[0052] As described above, the electric vehicle 1 of this embodiment includes a drive unit 10 having a first rotating electric machine 12 as a motor arranged in the motor room 2 of the electric vehicle 1, an inverter unit 14 electrically connected to the first rotating electric machine 12, and a mount bracket 10a that supports the drive unit 10 in the motor room 2. The first rotating electric machine 12 includes a motor housing 120, and the inverter unit 14 is placed on the upper surface of the motor housing 120 and fixed to the motor housing 120 at fixing points 14a arranged on the outer edge of the inverter unit 14. The motor housing 120 includes an upright wall 121 that stands upright above the motor housing 120, outside the fixing points 14a of the inverter unit 14 in the vehicle width direction, and one end of the mount bracket 10a is fixed to the upper surface 121a of the upright wall 121.

[0053] With this configuration, an upright wall 121 is provided outside the fixing point 14a of the inverter unit 14 in the vehicle width direction, and the mount bracket 10a is provided on the upper part of this upright wall 121. This prevents a component of the motor room 2 (for example, the side member 6a) fastened to the other end of the mount bracket 10a from directly interfering with the inverter unit 14 from outside in the vehicle width direction when a large load is input during a collision, etc., and suppresses problems with the insulation of the inverter unit 14.

[0054] In addition, in this embodiment, the electric vehicle 1 has a side member 6a arranged on the side of the drive unit 10 in the fore-and-aft direction of the vehicle, and one end of the mount bracket 10a is fixed to the upper surface 121a of the upright wall 121, and the other end of the mount bracket 10a is fixed to the side member 6a located outside the upright wall 121 in the vehicle width direction.

[0055] With this configuration, even if the side member 6a located on the outside of the drive unit 10 is deformed when a large load is input, such as during a collision, direct interference with the inverter unit 14 from the outside in the vehicle width direction is prevented.

[0056] In addition, in this embodiment, the inverter unit 14 and the first rotating electric machine 12 are electrically connected via a three-phase bus bar 143, and the three-phase bus bar 143 is positioned vertically below the first fastening point at which the mount bracket 10a is fastened to the upright wall 121.

[0057] With this configuration, the highly rigid upright wall 121 is interposed between the three-phase bus bar 143 to which high voltage current is applied and the side member 6a fastened to the mount bracket 10a, preventing the side member 6a from climbing over the upright wall 121 and interfering with the three-phase bus bar 143.

[0058] In addition, in this embodiment, the motor housing 120 of the first rotating electric machine 12, which has high rigidity in the vehicle width direction, is interposed between the three-phase bus bar 143 and the side member 6a, so the side member 6a interferes with the motor housing 120 but does not interfere with the three-phase bus bar 143.

[0059] Furthermore, in this embodiment, the inverter unit 14 has an inverter housing 141 and a high-voltage component 142, and is configured such that the high-voltage component 142 is housed in the inverter housing 141, the motor housing 120 has a recess 125 formed so as to be recessed from its upper surface, and the high-voltage component 142 is arranged so that a portion of it protrudes below the bottom of the inverter housing 141 and is housed in the recess 125 below the inverter housing 141.

[0060] With this configuration, the high-voltage components 142 are surrounded by the highly rigid motor housing 120, so that the side members 6a do not interfere with the motor housing 120 but do not interfere with the high-voltage components 142, and the inverter unit 14 can be made smaller in height.

[0061] In addition, in this embodiment, the other end of the mount bracket 10a (vehicle body side bracket 112) is fixed to the side member 6a by a plurality of second fastening points (fastening points 112a, 112b, 112c) in the fore-and-aft direction of the vehicle, and one end of the mount bracket 10a (drive unit side bracket 111) is fastened to the upright wall 121 by a plurality of first fastening points (111a, 111b, 111c) in the fore-and-aft direction of the vehicle, and the fore-and-aft spacing of the second fastening points is greater than the fore-and-aft spacing of the first fastening points.

[0062] With this configuration, by increasing the longitudinal distance between the second fastening point of the mount bracket 10a and the side member 6a, even when a large load is input, the side member 6a is less likely to bend toward the drive unit 10 at the side of the drive unit 10 at the location where the mount bracket 10a is located, and interference of the side member 6a with the drive unit 10 is suppressed.

[0063] In addition, in this embodiment, the first fastening points are positioned higher in the vertical direction than the second fastening points, and at least one of the second fastening points (fastening point 112a) is positioned further forward in the vehicle's fore-and-aft direction than the first fastening point (fastening point 111a).

[0064] With this configuration, even when a large load is input, the mount bracket 10a moves as if pulled diagonally upward and rearward of the electric vehicle 1, thereby preventing the side member 6a or the mount bracket 10a from interfering with the inverter unit 14.

[0065] The above describes embodiments of the present invention, but the configurations described in the above embodiments and each modified example only show some of the application examples of the present invention and are not intended to limit the technical scope of the present invention.

[0066] In the above-described embodiment, the drive unit 10 is described as being an electric vehicle 1 equipped with the engine 15 and the second electric rotating machine 16 in addition to the first electric rotating machine 12 and the inverter unit 14, but the present invention is not limited to this. A similar configuration can also be used in an electric vehicle that is not equipped with the engine 15 and the second electric rotating machine 16 and that is driven by the driving force of the first electric rotating machine 12.

Claims

1. A drive unit for an electric vehicle, a drive unit including a rotating electric machine disposed in a motor room of an electric vehicle and an inverter unit electrically connected to the rotating electric machine; a mount bracket that supports the drive unit on a side member that is disposed in the motor room on the side of the drive unit and across the vehicle in the front-to-rear direction; Equipped with the rotating electric machine includes a motor housing; the inverter unit is placed on an upper surface of the motor housing and fixed to the motor housing at fixing points disposed on an outer edge of the inverter unit; the motor housing includes an upright wall that stands upright above the motor housing and is located outside the fixing point of the inverter unit in a vehicle width direction, One end of the mounting bracket is fixed to the upper surface of the upright wall, The upright wall is interposed between the inverter unit and the side member. Drive unit for electric vehicles.

2. A drive unit for an electric vehicle according to claim 1, the electric vehicle has side members arranged on either side of the drive unit across a front-to-rear direction of the vehicle, One end of the mount bracket is fastened to an upper surface of the upright wall, and the other end of the mount bracket is fastened to the side member located outward of the upright wall in the vehicle width direction. Drive unit for electric vehicles.

3. A drive unit for an electric vehicle according to claim 2, the inverter unit and the rotating electric machine are electrically connected via a bus bar, the bus bar is disposed vertically below a fastening point at which the mount bracket is fastened to the upright wall. Drive unit for electric vehicles.

4. A drive unit for an electric vehicle according to claim 3, A drive unit for an electric vehicle, wherein the motor housing is interposed between the bus bar and the side member in the vehicle width direction.

5. A drive unit for an electric vehicle according to claim 4, the inverter unit has an inverter housing and high-voltage components, and is configured such that the high-voltage components are accommodated in the inverter housing; The motor housing has a recess formed in an upper surface thereof, the high-voltage component is disposed so that a portion thereof protrudes downward from the bottom of the inverter housing, and is accommodated in the recess below the inverter housing; Drive unit for electric vehicles.

6. A drive unit for an electric vehicle according to claim 2, the other end of the mount bracket is fastened to the side member at a plurality of second fastening points in the front-rear direction of the vehicle, One end of the mount bracket is fastened to the upright wall at a plurality of first fastening points in the front-rear direction of the vehicle, The longitudinal spacing of the plurality of second fastening points on the side member is greater than the longitudinal spacing of the plurality of first fastening points on the upright wall. Drive unit for electric vehicles.

7. A drive unit for an electric vehicle according to claim 6, The first fastening point is located at a higher position than the second fastening point in the vertical direction, At least one of the second fastening points is disposed forward of the first fastening point in the vehicle longitudinal direction. Drive unit for electric vehicles.

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