Attachment structure of electromotor of hybrid vehicle

The present invention relates to a mounting structure of an electric motor connected to a rear wheel in a hybrid vehicle.

There is known a hybrid vehicle mainly composed of FF vehicles, in which an electric motor is connected to the rear wheels of an FF vehicle (front engine / front drive vehicle) so that the vehicle can run with the engine and the electric motor. In front-wheel drive vehicles, it is known that the fuel tank is placed under the rear seats to secure a large interior space and accommodation space. On the other hand, as an example of connecting the electric motor to the rear wheels, it is conceivable that the electric motor is installed in the vicinity of the rear wheels to simplify the structure and improve the transmission efficiency.

Therefore, in the case of a hybrid vehicle in which an electric motor is connected to the rear wheels, mainly an FF vehicle, a configuration in which a fuel tank is arranged immediately in front of the electric motor is conceivable.

<p><patcit num="1"><text>Japanese Unexamined Patent Publication No. 11-165516</text></patcit></p>

<p> However, in the case of a hybrid vehicle having the above configuration, if a collision occurs from the rear (hereinafter referred to as a "rear collision"), the electric motor may be pushed forward by the rear collision and the fuel tank may be damaged.</p><p> An object of the present invention is to solve the above problems and to provide a mounting structure of an electric motor in a hybrid vehicle in which an electric motor is arranged at the rear of the vehicle so that the fuel tank is not damaged even if the electric motor is pushed out at the time of a rear collision. ..</p>

<p> In order to solve the above problems, the present invention has the following structure for mounting an electric motor in a hybrid vehicle.</p><p> The hybrid vehicle has a configuration in which an electric motor is connected to the rear wheels of an FF vehicle (front engine / front drive vehicle). The vehicle is equipped with a grid-shaped subframe at the rear. For example, the subframe is formed in a grid shape by arranging front and rear extension members on the left and right, and attaching front cross members and rear cross members to the front and rear of the front and rear extension members, respectively. A rear suspension device or the like may be attached to the subframe, and the rear wheels may be held vertically via the suspension device. A rear motor mount, which is a structural member, is attached to the rear of the subframe.</p><p> The electric motor is installed inside the subframe, that is, in the space surrounded by the left and right front and rear extension members, the front cross member, the rear cross member, and the rear motor mount.</p><p> Specifically, the electric motor is installed as follows. A bracket (front motor mount bracket) for attaching the connecting member (front motor mount) is provided on the front cross member. The front motor mount has a mount portion in the front and a mounting portion formed integrally with the mount portion in the rear. Attach the mount part of the front motor mount to the bracket, and attach the mounting part to the rear wheel motor. As a result, the rear wheel motor is fixed to the subframe.</p><p> Further, the rear cross member is passed below the rear wheel motor with a slight gap between the rear cross member and the rear wheel motor. The rear motor mount is attached to the rear of the rear wheel motor so that it passes through the rear wheel motor with a slight gap. Both ends of the rear motor mount are attached to the left and right ends of the rear cross member. Furthermore, the rear wheel motor is attached to the subframe at a position slightly higher than the center of the mount portion of the front motor mount. The fuel tank is arranged in front of the front cross member at approximately the same height as the front cross member with a slight gap between the fuel tank and the front cross member.</p>

<p> The mounting structure of the electric motor according to the present invention has the following effects. Since the rear wheel electric motor is provided in the vicinity of the rear wheels, the rear wheels can be efficiently driven to drive the vehicle. In the unlikely event that the vehicle is rear-end collision, the rear motor mount receives the impact from the rear-end collision vehicle. Since there is a gap between the rear motor mount and the rear wheel motor, the rear wheel motor will not be damaged.</p><p> If the rear collision energy is large and the rear motor mount or rear cross member is deformed, the rear wheel motor is pushed forward and the front motor mount is broken. However, the rear wheel motor is blocked by the front cross member provided in the front and pushed diagonally downward.</p><p> As a result, even if the rear wheel motor is pressed from behind, it moves without coming into contact with the fuel tank. Therefore, damage to the fuel tank due to the rear wheel motor can be reliably prevented. Further, even if the front motor mount is broken, the rear wheel motor is mounted on the rear cross member, and the rear wheel motor is prevented from completely falling off from the vehicle.</p>

<figref num="1">It is a perspective view which shows one Example of the assembly structure of the electric motor which concerns on this invention.</figref><figref num="2">It is a perspective view which shows an example of a subframe.</figref><figref num="3">It is a perspective view which shows an example of the front motor mount.</figref><figref num="4">It is a side view which shows one Example of the assembly structure of the electric motor shown in FIG.</figref><figref num="5">It is a block diagram which shows an example of the vehicle which assembled the rear wheel electric motor.</figref>

An embodiment of an electric motor mounting structure in a hybrid vehicle according to the present invention will be described.

FIG. 5 shows the vehicle 10 as a hybrid vehicle. The vehicle 10 is equipped with an engine 12 in the front, a rear wheel electric motor 14 for traveling, and a fuel tank 22 in the rear. Hereinafter, the traveling direction of the vehicle 10 will be referred to as the front, the opposite will be referred to as the rear, the left and right will be determined based on this, the direction of gravity will be referred to downward, and the opposite will be referred to as upward.

The vehicle 10 has front wheels 16 on the front left and right and rear wheels 18 on the rear left and right. The engine 12 is a gasoline-fueled internal combustion engine, which is mounted between the left and right front wheels 16. A transmission, a differential mechanism (neither shown), or the like is assembled in the engine 12, and the rotational output of the engine 12 is transmitted to the front wheels 16 via these.

Vehicle 10 is equipped with an ECU (Electronic Control Unit) (not shown). The ECU obtains various information such as the operating status of the accelerator pedal and brake pedal (none of them are shown), the vehicle speed, and the charge amount of the battery 30, which will be described later, and appropriately controls the engine 12, the transmission, etc. based on these values. To do. The engine 12 is not limited to a gasoline engine.

A generator 20 is provided on the side of the engine 12. The generator 20 generates electricity by the rotational force input from the engine 12 and the front wheels 16. A battery 30 is provided in the central portion under the floor of the vehicle 10. The battery 30 is a battery for running the vehicle 10 and has a relatively large capacity. The electric power generated by the generator 20 is stored in the battery 30. The generator 20 may be driven by electric power from the battery 30 to rotate the front wheels 16 or start the engine 12. Behind the vehicle 10, a subframe 50 to which the rear wheel electric motor 14 is assembled is provided inside.

Next, the subframe 50 will be described.

Figure 2 shows the subframe 50. As shown in FIG. 2, the subframe 50 has a grid shape, and has tubular members 52 and 54 (front and rear extension members) as main pipes provided on both the left and right sides, and a front cloth provided in front of the tubular members 52 and 54. It is formed of a member 56 (front left and right extension member) and a rear cross member 58 (rear left and right extension member) provided at the rear.

The front cross member 56 is a member having a quadrangular cross section and is provided in the width direction of the vehicle 10. The tip portions of the tubular members 52 and 54 are fixed to the front cross member 56 at predetermined intervals. In addition, fixing portions 60 are formed on the left and right ends of the front cross member 56. The fixing portion 60 is fixed to the chassis frame 35 (see FIG. 5) of the vehicle 10.

Further, a front motor mount bracket 62 is provided substantially in the center of the front cross member 56. The front motor mount bracket 62 is formed in a substantially U shape and extends below the front cross member 56. A front motor mount 64 as a connecting member is attached to the inside of the front motor mount bracket 62.

The front motor mount 64 is shown in FIG. As shown in FIG. 3, the front motor mount 64 is formed of a base 66 and a mounting piece 68 as a mounting portion provided on the base 66. A mount 70 is formed on the base 66, and the mount 70 is attached to the front motor mount bracket 62. The mounting piece 68 is a substantially triangular plate-shaped member, and mounting holes 71 are formed at each of the three corners.

The tubular members 52 and 54 are made of tubular members, and as shown in FIG. 2, each of the tubular members 52 and 54 is formed substantially symmetrically with respect to the front-rear direction of the vehicle 10. The tubular members 52 and 54 extend rearward from the front cross member 56 while maintaining a height substantially equal to that of the front cross member 56, and are curved so as to open outward near the middle. The rear ends of the tubular members 52 and 54 are connected to the left and right ends of the rear cross member 58, respectively.

A fixing portion 72 is formed at a connecting portion between the tubular members 52 and 54 and the rear cross member 58. The fixing portion 72 is fixed to the chassis frame 35 (see FIG. 5) of the vehicle 10.

The rear cross member 58 is a member having a quadrangular cross section, and both left and right ends are curved upward and are connected to tubular members 52 and 54 at both ends. The central part of the rear cross member 58 projects slightly forward. Mounting portions 74 are provided on the rear surfaces of the left and right ends of the rear cross member 58. As shown in FIG. 1, the rear motor mount 76 as a structural member is fixed to the mounting portion 74 with screws.

FIG. 1 shows a state in which the rear wheel motor 14 is assembled inside the subframe 50. The rear wheel electric motor 14 has a cylindrical shape and is mounted so that the direction of the output shaft (not shown) is parallel to the width direction of the vehicle 10.

The rear wheel electric motor 14 is provided with a terminal connecting portion 24 at the top. The terminal connecting portion 24 is a connecting port having a predetermined number of connecting terminals (not shown), and is arranged in front of the rear wall of the rear motor mount 76. One end of the power line 34 is connected to the terminal connecting portion 24. The power line 34 has a diameter of about 1 cm and has a sufficient thickness for passing a predetermined current. The other end of the power line 34 is connected to a power control unit 32 described later. The power line 34 connected to the terminal connecting portion 24 is curved upward from the terminal connecting portion 24 and is connected to the connection port 36 of the power control unit 32. The connection port 36 is arranged in front of the rear wall of the rear motor mount 76, like the terminal connecting portion 24 of the rear wheel motor 14.

A deceleration differential mechanism 38 is provided on the output shaft end surface (right side surface in the drawing) of the rear wheel motor 14. The reduction differential mechanism 38 includes a reduction gear and a differential gear inside, and left and right rear wheel drive shafts (not shown) are connected to the output end of the differential gear. The rear wheel drive shafts are each connected to the rear wheels 18, and the rotational output of the rear wheel electric motor 14 is transmitted to the left and right rear wheels 18 while performing differential differentials. The deceleration differential mechanism 38 may be provided with a speed-increasing gear inside instead of deceleration.

The reduction gear differential mechanism 38 has a mounting hole (not shown) on the left side surface, and a mounting piece 68 of the front motor mount 64 is fixed by a screw 73 as shown in FIG. 4 through the mounting hole. The rear wheel motor 14 is thereby attached to the front cross member 56.

The rear wheel motor 14<u style="single">Rear motor mount 76</u>And the center of rotation of the rear wheel motor 14 are installed at almost the same height. A fuel tank 22 is provided in front of the front cross member 56. The fuel tank 22 is a tank for storing the liquid fuel of the engine 12. The fuel tank 22 is provided below the floor surface of the vehicle 10 at substantially the same height as the front cross member 56.

A rear cross member 58 is passed to the lower part of the rear wheel electric motor 14 with a slight gap between the rear wheel electric motor 14 and the rear wheel electric motor 14. Further, behind the rear wheel electric motor 14, the rear motor mount 76 is passed with a slight gap between the rear wheel electric motor 14 and the rear wheel electric motor 14.

A power control unit 32 is provided above the rear wheel electric motor 14. The power control unit 32 is attached to the chassis frame 35 via a stay or the like, and controls the charging / discharging of the battery 30 and the operation of the rear wheel electric motor 14 according to the instructions from the ECU.

The power control unit 32 has a connection port 36, and the power line 34 described above is connected to the power control unit 32, and is connected to the rear wheel electric motor 14 via the power line 34. Further, the power control unit 32 is connected to the battery 30 via the power line 31.

Further, the vehicle 10 is provided with an external power supply connection port 33, for example, on the rear side surface. The external power supply connection port 33 is a connection port for connecting an external power source, and charges the battery 30 using the external power source connected to the external power supply connection port 33.

Next, the action and effect in the mounting structure of the electric motor of the hybrid vehicle described above will be described.

When the engine 12 operates and the power is transmitted to the front wheels 16, the vehicle 10 runs in front wheel drive. When electric power is supplied to the rear wheel electric motor 14 from the power control unit 32, the driving force of the rear wheel electric motor 14 is transmitted to the rear wheels 18 through the deceleration differential mechanism 38, and the vehicle 10 travels on the rear wheels. The running of the vehicle 10 may be front-wheel drive or rear-wheel drive, or may be all-wheel drive in which the front and rear wheels rotate at the same time. The rear wheel 18 is supported by a suspension device provided on the subframe 50 and operates appropriately in the vertical direction.

Should the vehicle 10 be hit backwards, the impact force due to the rear collision is absorbed by crushing the crushable zone a (see FIG. 5) at the rear of the vehicle 10. If the impact force is within a predetermined range, the damage will remain in the crushable zone a, and no significant damage will occur in front of the rear motor mount 76.

When the impact force is large and the impact force reaches the rear motor mount 76, the rear motor mount 76 is deformed forward. If the impact is absorbed by the deformation of the rear motor mount 76, the rear wheel motor 14 will not be damaged.

When the impact force becomes larger and the rear motor mount 76 is greatly displaced forward while deforming the subframe 50, the rear motor mount 76 presses the rear wheel motor 14. Then, the front motor mount bracket 62 is broken, and the rear wheel motor 14 moves forward. However, the rear wheel electric motor 14 comes into contact with the front cross member 56 and is prevented from moving forward, and moves diagonally downward so as to dive under the front cross member 56.

As a result, the rear wheel electric motor 14 moves diagonally downward even if it receives a large impact, and the fuel tank 22 is not damaged due to the contact of the rear wheel electric motor 14.

Further, since the rear cross member 58 is provided below the rear wheel motor 14, even if the front motor mount bracket 62 is broken, the rear wheel motor 14 is mounted on the rear cross member 58, and the vehicle 10 The rear wheel motor 14 does not fall on the road.

In the above example, the fuel tank 22 is arranged in front of the rear wheel electric motor 14, but the present invention is not limited to the fuel tank 22, and other members may be used. For example, expensive or important parts such as a battery, a fuel cell, and an inverter may be arranged in front of the rear wheel motor 14.

The present invention can be used for electric vehicles, hybrid vehicles, and the like in which an electric motor is connected to the rear wheels.

10 ... vehicle 12 ... engine 14 ... Rear wheel motor 18 ... rear wheel 22 ... Fuel tank 24 ... Terminal connection 30 ... Battery 31 ... Power line 32 ... Power control unit 34 ... Power line 50 ... subframe 52.54 ... Tubular member 56 ... Front cross member 58 ... Rear cross member 64 ... Front motor mount 72 ... Fixed part 74 ... Mounting part 76 ... Rear motor mount