Electric vehicles

Abstract

To provide an electric vehicle that can improve the fastening rigidity of the split case of the drive unit and suppress vibration of the case. [Solution] A high-voltage component 16 is positioned on the front of the drive unit 30. The drive unit 30 comprises a split case 40 having a first case 41, a second case 42, a third case 43, and a fourth case 44 that are fastened to each other while being adjacent to each other from one side to the other in the vehicle width direction. The rear bracket 12 is fastened to the rear surface of the first case 41 and the rear surface of the third case 43, and the high-voltage component 16 is fastened to the front surface of the second case 42 and the front surface of the fourth case 44.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 describes a drive device in which a plurality of units such as a drive motor and a speed reducer are connected in series. This drive device includes a split case in which a plurality of cases are fastened in the vehicle width direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the device described in Patent Document 1 has a problem that the case vibrates due to vibrations generated in the drive unit such as the internal motor or vibrations transmitted from the outside.

[0005] Therefore, an object of the present invention is to provide an electric vehicle capable of improving the fastening rigidity of the split case of the drive device and suppressing the vibration of the case.

Means for Solving the Problems

[0006] To solve the above problems, the present invention provides an electric vehicle comprising: a drive unit arranged in an engine room formed in the front of the vehicle and generating motor torque for driving; and a bracket fixed to the rear surface of the drive unit and supporting the drive unit on the vehicle body, wherein a high-voltage component is arranged on the front surface of the drive unit, the drive unit comprises a split case having a first case, a second case, a third case, and a fourth case that are fastened to each other while being arranged adjacent to each other from one side to the other in the vehicle width direction, the bracket is fastened to the rear surface of the first case and the rear surface of the third case, and the high-voltage component is fastened to the front surface of the second case and the front surface of the fourth case. [Effects of the Invention]

[0007] Thus, according to the present invention, it is possible to provide an electric vehicle that can improve the fastening rigidity of the split case of the drive unit and suppress vibration of the case. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a plan view of the drive system of an electric vehicle according to one embodiment of the present invention. [Figure 2] Figure 2 is a rear view of the drive unit of an electric vehicle according to one embodiment of the present invention. [Figure 3] Figure 3 is a right side view of the drive unit of an electric vehicle according to one embodiment of the present invention. [Figure 4] Figure 4 is a front view of the drive unit of an electric vehicle according to one embodiment of the present invention. [Figure 5] Figure 5 is a cross-sectional view of the electric vehicle shown in Figure 3, taken along the VV direction. [Modes for carrying out the invention]

[0009] An electric vehicle according to one embodiment of the present invention comprises a drive unit arranged in an engine room formed at the front of the vehicle and generating motor torque for driving, and a bracket fixed to the rear surface of the drive unit and supporting the drive unit on the vehicle body, wherein high-voltage components are arranged on the front surface of the drive unit, the drive unit comprises a split case having a first case, a second case, a third case, and a fourth case fastened to each other while being adjacent to each other from one side to the other in the vehicle width direction, the bracket is fastened to the rear surface of the first case and the rear surface of the third case, and the high-voltage components are fastened to the front surface of the second case and the front surface of the fourth case. As a result, the electric vehicle according to one embodiment of the present invention can improve the fastening rigidity of the split case of the drive unit and suppress vibration of the case. [Examples]

[0010] Hereinafter, an electric vehicle according to one embodiment of the present invention will be described with reference to the drawings. Figures 1 to 5 show an electric vehicle according to one embodiment of the present invention.

[0011] In Figures 1 to 5, the up, down, front, rear, left, and right directions are based on the electric vehicle as it is positioned on the vehicle, with the front-rear direction of the vehicle being the front-rear direction, the left-right direction (vehicle width direction) being the left-right direction, and the up-down direction (vehicle height direction) being the up-down direction.

[0012] As shown in Figure 1, a drive unit 30 that generates motor torque for driving is provided in the engine compartment 3 at the front of the vehicle 1. The drive unit 30 is positioned transversely in the engine compartment 3 such that its internal motor output shaft 51 (see Figure 5) extends in the vehicle width direction. The vehicle 1 in this embodiment constitutes an electric vehicle.

[0013] Drive wheels (not shown) are located to the left and right of the drive unit 30, and the rotation output from the drive unit 30 is transmitted to the drive wheels. The vehicle 1 comprises a body 2, which has a subframe 2A and a body member 2B. The subframe 2A and body member 2B constitute the bottom of the body 2 and support the drive unit 30. The subframe 2A supports the rear of the drive unit 30 and lower arms (not shown), etc. The body member 2B supports the ends of the drive unit 30 in the vehicle width direction, etc.

[0014] As shown in Figure 5, the drive unit 30 comprises a motor 50, a reduction mechanism 53, a differential device 54, and a split case 40 that serves as a housing for these components.

[0015] Case 40 comprises a first case 41 that constitutes the left end of the drive unit 30, a second case 42 fastened to the right end of the first case 41, a third case 43 fastened to the right end of the second case 42, a fourth case 44 connected to the right end of the third case 43, and a cover member 45 fastened to the right end of the fourth case 44.

[0016] The first case 41 has a partition member 41A at its right end, and the partition member 41A extends in the front-to-back and up-to-down directions so as to separate the internal space of the first case 41 from the internal space of the second case 42. The partition member 41A rotatably supports the left end of the motor output shaft 51 of the motor 50 and the right end of the differential device 54, and the reduction shaft 53A of the reduction mechanism 53 passes through it.

[0017] The third case 43 houses the motor 50. At the center of the motor 50 is a hollow motor output shaft 51 that outputs motor torque. The motor output shaft 51 extends in the vehicle width direction from inside the second case 42 to inside the fourth case 44.

[0018] In the second case 42, a bearing 57 is provided for rotatably supporting a portion of the motor output shaft 51 to the left of the motor 50. In the fourth case 44, a bearing 58 is provided for rotatably supporting a portion of the motor output shaft 51 to the right of the motor 50.

[0019] In the first case 41 and the second case 42, a speed reduction mechanism 53 for reducing the rotation transmitted from the motor 50 and a differential device 54 for differentially and rotatably transmitting the rotation reduced by the speed reduction mechanism 53 to the left and right drive shafts 55 and 56 are arranged.

[0020] The differential device 54 is arranged to the left of the left end of the motor output shaft 51. The differential device 54 includes a ring gear 54A to which rotation is transmitted from the speed reduction mechanism 53. The left drive shaft 55 is connected to the left end of the differential device 54. The right drive shaft 56 is connected to the right end of the differential device 54. This drive shaft 56 is coaxially arranged inside the hollow motor output shaft 51.

[0021] The speed reduction mechanism 53 has a reduction shaft 53A, a large-diameter first reduction gear 53B provided on the reduction shaft 53A, and a small-diameter second reduction gear 53C. The reduction shaft 53A is arranged in front of the differential device 54 and parallel to the motor output shaft 51. The first reduction gear 53B meshes with the gear 51A on the motor output shaft 51, and the second reduction gear 53C meshes with the ring gear 54A of the differential device 54.

[0022] The case 40 is formed with a roughly circular cross-sectional shape and has a cylindrical portion 40A extending in the vehicle width direction and a bulging portion 40B that bulges forward from the left end of the cylindrical portion 40A. The cylindrical portion 40A is the part that houses the motor 50, the motor output shaft 51 and the differential device 54. The bulging portion 40B is the part that houses the reduction mechanism 53. In a left side view, the case 40 has an oval shape formed by the combination of the cylindrical portion 40A and the bulging portion 40B, and in a plan view, it has an L-shape formed by the intersection of the cylindrical portion 40A and the bulging portion 40B.

[0023] As shown in Figures 1, 2, 3, and 4, a left front bracket 10 is fixed to the left end of the drive unit 30 to support the drive unit 30 on the vehicle body 2, and a mount insulator 14 is connected to the front end 10E of the left front bracket 10. The mount insulator 14 is fixed to the vehicle body member 2B.

[0024] An elastic member 14A, such as a mounting rubber, is provided inside the mount insulator 14, and the left front bracket 10 and the mount insulator 14 are elastically connected via the elastic member 14A. Therefore, the left end of the drive unit 30 is elastically supported by the vehicle body member 2B via the left front bracket 10 and the mount insulator 14.

[0025] The left front bracket 10 has three fastening parts 10A, 10B, and 10C that are fastened to the left end of the first case 41. Fastening part 10A is located in front of the center position of the drive unit 30 (the axial center position of the motor output shaft 51) at the left end of the first case 41, and is positioned at the front end of the cylindrical part 40A. Fastening part 10B is located in front of and above fastening part 10A. Fastening part 10C is located in front of and below fastening part 10A.

[0026] A right front bracket 11, which supports the drive unit 30 on the vehicle body 2, is fixed to the right end of the drive unit 30, and a mount insulator 15 is connected to the front end 11E of the right front bracket 11. The mount insulator 15 is fixed to the vehicle body member 2B.

[0027] An elastic member 15A, such as a mounting rubber, is provided inside the mount insulator 15, and the right front bracket 11 and the mount insulator 15 are elastically connected via the elastic member 15A. Therefore, the right end of the drive unit 30 is elastically supported by the vehicle body member 2B via the right front bracket 11 and the mount insulator 15.

[0028] The right front bracket 11 has four fastening parts 11A, 11B, 11C, and 11D that are fastened to the right end of the fourth case 44. Fastening part 11A is fastened to the right end of the fourth case 44 at a position behind and above the center of the drive unit 30. Fastening part 11B is fastened to the right end of the fourth case 44 at a position in front and below the center of the drive unit 30.

[0029] An upper support portion 44A is formed on the upper front of the fourth case 44, to which the upper part of the right front bracket 11 and the upper part of the high-voltage component 16 are fixed. The upper support portion 44A extends from the front outer periphery of the fourth case 44 toward the front and above the vehicle. The front end surface of the upper support portion 44A forms a flat surface that extends in the vertical direction.

[0030] A lower support portion 44B is formed at the lower front of the fourth case 44, to which the lower part of the right front bracket 11 and the lower part of the high-voltage component 16 are fixed. The lower support portion 44B extends from the front outer periphery of the fourth case 44 toward the front and downward of the vehicle. The front end surface of the lower support portion 44B forms a flat surface that extends in the vertical direction.

[0031] The fastening portion 11C is fastened to the right end of the upper support portion 44A of the fourth case 44 at a position forward and above the center of the drive unit 30. The fastening portion 11D is fastened to the right end of the lower support portion 44B of the fourth case 44 at a position forward and below the center of the drive unit 30.

[0032] A rear bracket 12 is fixed to the center of the rear of the drive unit 30 in the vehicle width direction, supporting the drive unit 30 to the vehicle body 2. The rear bracket 12 has a main body portion 12E that is fastened to the drive unit 30, and two vehicle body side connecting portions 12F that extend rearward from the main body portion 12E. A dash panel 2C is provided behind the rear bracket 12, and the dash panel 2C separates the engine room 3 from the passenger compartment behind it (not shown).

[0033] The main body 12E is formed in a roughly box shape with the longer side in the vehicle width direction when viewed from above and from the rear. A mount insulator 20 is connected to the rear end of the vehicle body side connecting part 12F. The mount insulator 20 is fixed to the subframe 2A.

[0034] An elastic member 20A, such as a mounting rubber, is provided inside the mount insulator 20, and the rear bracket 12 and the mount insulator 20 are elastically connected via the elastic member 20A. Therefore, the rear surface of the drive unit 30 is elastically supported by the subframe 2A via the rear bracket 12 and the mount insulator 20.

[0035] The main body 12E has four fastening parts 12A, 12B, 12C, and 12D that are fastened to the case 40. Fastening part 12A is located in the upper left corner of the main body 12E and is fastened to the rear surface of the partition member 41A of the first case 41. Fastening part 12B is located in the upper right corner of the main body 12E and is fastened to the rear surface of the third case 43.

[0036] The fastening portion 12C is located at the lower left corner of the main body portion 12E and is fastened to the rear surface of the partition member 41A of the first case 41. The fastening portion 12D is located at the lower right corner of the main body portion 12E and is fastened to the rear surface of the third case 43.

[0037] A high-voltage component 16 is fixed to the front of the drive unit 30, near the right end in the vehicle width direction. The high-voltage component 16 consists of an inverter that converts power from a battery (not shown) to a predetermined voltage and frequency and supplies it to the motor 50. The high-voltage component 16 is formed in a roughly square, box-like shape when viewed from the front. The high-voltage component 16 has four fastening parts 16A, 16B, 16C, and 16D that are fastened to the case 40.

[0038] Fastening portion 16A is located in the upper left corner of the high-voltage component 16 and fastens to the upper front of the second case 42. Fastening portion 16C is located in the lower left corner of the high-voltage component 16 and fastens to the lower front of the second case 42.

[0039] The fastening portion 16B is located at the upper right corner of the high-voltage component 16 and is fastened to the front end of the upper support portion 44A on the front of the fourth case 44. The fastening portion 16D is located at the lower right corner of the high-voltage component 16 and is fastened to the front end of the lower support portion 44B on the front of the fourth case 44.

[0040] An electric water pump 17 is positioned in front of the left end of the drive unit 30, above the left front bracket 10. The water pump 17 pumps coolant cooled by a radiator (not shown) to the drive unit 30. The water pump 17 has a coolant inlet pipe 17A for taking in coolant, and a coolant outlet pipe 17B that extends perpendicular to the coolant inlet pipe 17A and discharges the coolant. A support portion 10F for supporting the water pump 17 from below is formed integrally with the left front bracket 10 on the upper part of the left front bracket 10.

[0041] The rear bracket 12 is fastened to the rear surface of the first case 41 and the rear surface of the third case 43. The high-voltage component 16 is fastened to the front surface of the second case 42 and the front surface of the fourth case 44. The rear bracket 12 constitutes the bracket in this invention.

[0042] The rear bracket 12 has a fastening portion 12A which serves as the upper fastening portion of the first case and is fastened to the upper part of the rear surface of the first case 41, a fastening portion 12C which serves as the lower fastening portion of the first case and is fastened to the lower part of the rear surface of the first case 41, a fastening portion 12B which serves as the upper fastening portion of the third case and is fastened to the upper part of the rear surface of the third case 43, and a fastening portion 12D which serves as the lower fastening portion of the third case and is fastened to the lower part of the rear surface of the third case 43.

[0043] The high-voltage component 16 has a fastening portion 16A which serves as the upper fastening portion of the second case and is fastened to the upper part of the front of the second case 42, a fastening portion 16C which serves as the lower fastening portion of the second case and is fastened to the lower part of the front of the second case 42, a fastening portion 16B which serves as the upper fastening portion of the fourth case and is fastened to the upper part of the front of the fourth case 44, and a fastening portion 16D which serves as the lower fastening portion of the fourth case and is fastened to the lower part of the front of the fourth case 44.

[0044] The fastening portion 16A, which serves as the upper fastening portion of the second case, and the fastening portion 16B, which serves as the upper fastening portion of the fourth case, are positioned higher than the fastening portion 12A, which serves as the upper fastening portion of the first case, and the fastening portion 12B, which serves as the upper fastening portion of the third case.

[0045] The fastening portion 16C, which serves as the lower fastening portion for the second case, and the fastening portion 16D, which serves as the lower fastening portion for the fourth case, are positioned lower than the fastening portion 12C, which serves as the lower fastening portion for the first case, and the fastening portion 12D, which serves as the lower fastening portion for the third case.

[0046] The high-voltage component 16 and the rear bracket 12 are positioned lower than the upper end of the drive unit 30, and are facing each other front to back with the drive unit 30 in between.

[0047] As described above, in this embodiment, the high-voltage component 16 is positioned on the front of the drive unit 30. The drive unit 30 comprises a split case 40 having a first case 41, a second case 42, a third case 43, and a fourth case 44 that are fastened to each other while being adjacent to each other from one side to the other in the vehicle width direction. The rear bracket 12 is fastened to the rear surface of the first case 41 and the rear surface of the third case 43, and the high-voltage component 16 is fastened to the front surface of the second case 42 and the front surface of the fourth case 44.

[0048] As a result, the first case 41 and the third case 43 can be firmly fastened indirectly via the rear bracket 12, in addition to the direct fastening points between their end faces, allowing the rear bracket 12 to function as a reinforcing member. Similarly, the second case 42 and the fourth case 44 can be firmly fastened indirectly via the high-voltage component 16, in addition to the direct fastening points between their end faces, allowing the high-voltage component 16 to function as a reinforcing member. Furthermore, because the rear bracket 12 and the high-voltage component 16 function as reinforcing members, even if the number of direct fastening points between the end faces of the first case 41, second case 42, third case 43, and fourth case 44 of the segmented case 40 is reduced, the fastening rigidity of the case 40 can be ensured, and vibration of the case 40 due to vibration of the motor 50 can be suppressed. As a result, the fastening rigidity of the segmented case 40 of the drive unit 30 can be improved, and vibration of the case 40 can be suppressed.

[0049] In this embodiment, the case 40 houses the motor 50 and the motor output shaft 51 which extends in the vehicle width direction and outputs the motor torque of the motor 50, and the second case 42 and the fourth case 44 are provided with bearings 57 and 58 which rotatably support the motor output shaft 51.

[0050] As a result, the high-voltage component 16 is fastened to the second case 42 and the fourth case 44, which are equipped with bearings 57 and 58 that are susceptible to vibrations from the motor output shaft 51 of the motor 50. The weight of the high-voltage component 16 dampens the vibrations of the motor 50, thereby suppressing the vibrations of the case 40. Furthermore, even if one of the components of the high-voltage component 16 or the rear bracket 12 resonates with the vibrations of the motor 50, the other component can suppress the vibration, thus suppressing the vibrations of the case 40.

[0051] Furthermore, in this embodiment, the rear bracket 12 has a fastening portion 12A as a first case upper fastening portion fastened to the upper part of the rear surface of the first case 41, a fastening portion 12C as a first case lower fastening portion fastened to the lower part of the rear surface of the first case 41, a fastening portion 12B as a third case upper fastening portion fastened to the upper part of the rear surface of the third case 43, and a fastening portion 12D as a third case lower fastening portion fastened to the lower part of the rear surface of the third case 43. Furthermore, the high-voltage component 16 has a fastening portion 16A as a second case upper fastening portion fastened to the upper part of the front surface of the second case 42, a fastening portion 16C as a second case lower fastening portion fastened to the lower part of the front surface of the second case 42, a fastening portion 16B as a fourth case upper fastening portion fastened to the upper part of the front surface of the fourth case 44, and a fastening portion 16D as a fourth case lower fastening portion fastened to the lower part of the front surface of the fourth case 44. Furthermore, the fastening portion 16A as the upper fastening portion of the second case and the fastening portion 16B as the upper fastening portion of the fourth case are positioned higher than the fastening portion 12A as the upper fastening portion of the first case and the fastening portion 12B as the upper fastening portion of the third case, while the fastening portion 16C as the lower fastening portion of the second case and the fastening portion 16D as the lower fastening portion of the fourth case are positioned lower than the fastening portion 12C as the lower fastening portion of the first case and the fastening portion 12D as the lower fastening portion of the third case.

[0052] As a result, the fastening positions of the rear bracket 12 and the high-voltage component 16 to the case 40 are asymmetrical in the vertical and vehicle width directions. This allows the stress acting on the case 40 due to the weight and inertia of the rear bracket 12 and the high-voltage component 16 to be distributed, thereby suppressing deformation and vibration of the case 40 caused by stress concentration. Furthermore, the asymmetrical fastening positions suppress resonance of the case 40 caused by vibrations generated in the rear bracket 12, the high-voltage component 16, and the motor 50.

[0053] Furthermore, in this embodiment, the high-voltage component 16 and the rear bracket 12 are positioned lower than the upper end of the drive unit 30, and are arranged facing each other front to back with the drive unit 30 in between.

[0054] This allows the center of gravity of the drive unit 30 in the front-to-back direction to be positioned near the center of the case 40, and the center of gravity of the drive unit 30 in the up-to-down direction to be positioned at a low position. As a result, vibrations of the case 40 caused by an imbalance in the front-to-back direction of the center of gravity can be suppressed, and vibrations of the case 40 caused by a high center of gravity can be suppressed.

[0055] While embodiments of the present invention have been disclosed, it will be apparent to those skilled in the art that modifications can be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims. [Explanation of symbols]

[0056] 1 vehicle 2 car bodies 3. Engine Room 12 Rear Bracket (Bracket) 12A Fastening section (Upper fastening section of the first case) 12B Fastening section (upper fastening section of the third case) 12C Fastening section (lower fastening section of the first case) 12D Fastening section (lower fastening section of the third case) 16 High-voltage components 16A Fastening section (upper fastening section of the second case) 16B Fastening section (upper fastening section of the 4th case) 16C Fastening section (lower fastening section of the second case) 16D Fastening section (lower fastening section of the 4th case) 30 Drive unit 40 cases 41 Case 1 42 Case 2 43 Case 3 44. Case 4 50 motors 51 Motor output shaft 57 Bearings 58 Bearings

Claims

1. A drive unit is located in the engine compartment formed at the front of the vehicle and generates motor torque for driving, An electric vehicle comprising a bracket fixed to the rear surface of the drive unit and supporting the drive unit on the vehicle body, High-voltage components are arranged on the front of the aforementioned drive unit. The drive unit comprises a split case having a first case, a second case, a third case, and a fourth case that are fastened to each other while being arranged adjacent to each other from one side to the other in the vehicle width direction. The bracket is fastened to the rear surface of the first case and the rear surface of the third case. The electric vehicle is characterized in that the high-voltage component is fastened to the front of the second case and the front of the fourth case.

2. The aforementioned case houses a motor and a motor output shaft that extends in the vehicle width direction and outputs the motor torque of the motor. The electric vehicle according to claim 1, characterized in that the second case and the fourth case are provided with bearings that rotatably support the motor output shaft.

3. The bracket has a first case upper fastening portion fastened to the upper part of the rear surface of the first case, a first case lower fastening portion fastened to the lower part of the rear surface of the first case, a third case upper fastening portion fastened to the upper part of the rear surface of the third case, and a third case lower fastening portion fastened to the lower part of the rear surface of the third case. The high-voltage component includes a second case upper fastening portion fastened to the upper part of the front of the second case, a second case lower fastening portion fastened to the lower part of the front of the second case, a fourth case upper fastening portion fastened to the upper part of the front of the fourth case, and a fourth case lower fastening portion fastened to the lower part of the front of the fourth case. The second case upper fastening portion and the fourth case upper fastening portion are positioned higher than the first case upper fastening portion and the third case upper fastening portion. The electric vehicle according to claim 2, characterized in that the second case lower fastening portion and the fourth case lower fastening portion are positioned lower than the first case lower fastening portion and the third case lower fastening portion.

4. The electric vehicle according to claim 3, characterized in that the high-voltage component and the bracket are arranged facing each other front to back, with the drive unit in between, at a position lower than the upper end of the drive unit.

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