JP7144738B2 - vehicle drive - Google Patents

Description

TECHNICAL FIELD The present invention relates to a driving device, and more particularly to a driving device for a vehicle equipped with a battery.

Japanese Patent No. 5280961 (Patent Document 1) describes a drive control device for a vehicle. In this drive control device, a drive device is provided on the rear wheel side of the vehicle, and two motors provided in this drive device drive the rear wheels of the vehicle, respectively. Thus, in a vehicle drive system that uses a motor to drive a vehicle, it is necessary to mount a battery storing electric energy for operating the motor in the vehicle.

Japanese Patent No. 5280961

In a so-called hybrid vehicle equipped with an internal combustion engine and a motor described in Patent Document 1, or an electric vehicle in which the vehicle is driven only by the motor, the driving performance is improved when the motor is driven, and the kinetic energy is regenerated when the vehicle is decelerated. In order to improve the performance, it is necessary to mount a large-capacity battery on the vehicle. However, there is a limit to the electrical energy that can be stored per unit volume of the battery, and increasing the electrical capacity that can be stored poses the problem of increasing the size of the battery.

In addition, when a large-sized large-capacity battery is mounted on a vehicle, there arises a problem that the vehicle interior space for passengers to board becomes narrower and the space for loading luggage becomes narrower. In addition, the battery must avoid excessive damage, such as during a vehicle crash. For this reason, if a protective member is provided around the battery to prevent damage, the space required for mounting the battery becomes larger and larger, and there is a problem that the vehicle compartment and luggage space become narrower.

SUMMARY OF THE INVENTION Accordingly, the present invention provides a vehicle drive system capable of mounting a battery while preventing excessive damage to the battery in the event of a vehicle collision or the like, and without excessively narrowing the vehicle compartment or cargo loading space. It is intended to

In order to solve the above-described problems, the present invention provides a vehicle drive device equipped with a battery, comprising a prime mover disposed in the front of the vehicle and power transmission for transmitting the output of the prime mover to the rear wheels of the vehicle. It has a shaft, a cylindrical torque tube that accommodates the power transmission shaft inside, and a battery that stores electric energy for driving the vehicle. The battery is placed in a tunnel provided at the bottom of the vehicle, the battery is placed in the tunnel so as to be adjacent to the torque tube, and the bottom of the tunnel is covered with a detachably attached cover member. , the battery is arranged below the torque tube in the tunnel portion and can be replaced by removing the cover member; The inverter is characterized in that it is arranged above the torque tube in the tunnel section .

In the vehicle drive system of the present invention, the output of the prime mover arranged in the front part of the vehicle is transmitted to the rear wheels of the vehicle via the power transmission shaft. The power transmission shaft is housed inside a cylindrical torque tube, and the torque tube is arranged in a tunnel provided at the bottom of the vehicle so as to extend in the longitudinal direction of the vehicle. A battery storing electrical energy for driving the vehicle is arranged in the tunnel section adjacent to the torque tube.

According to the present invention configured as described above, the battery is arranged in the tunnel portion under the vehicle. Here, the tunnel portion is relatively resistant to deformation when the vehicle collides from the front, the side, or the rear. Therefore, by arranging the battery in the tunnel portion, damage to the battery can be effectively avoided even when the vehicle collides. In addition, by locating the battery inside the tunnel, it is possible to effectively reduce the risk of damage to the battery due to impacts from outside the tunnel without installing a special protective member to prevent damage to the battery. can do. As a result, the battery can be protected while suppressing an increase in size.

On the other hand, a power transmission shaft that transmits the output of the prime mover to the rear wheels of the vehicle extends through the tunnel. Since the power transmission shaft rotates while the vehicle is running, if the power transmission shaft is deformed due to a collision with the vehicle while the vehicle is running, the rotating power transmission shaft will be damaged by the battery arranged in the tunnel. Interference can damage the battery. However, in the vehicle drive system of the present invention, since the power transmission shaft is housed inside the cylindrical torque tube, even if the power transmission shaft is deformed during rotation, it directly interferes with the battery. , can prevent the battery from being damaged. In addition, since the power transmission shaft is housed in the torque tube, the battery can be placed adjacent to the torque tube while ensuring sufficient safety, and the space inside the tunnel section is effectively used for housing the battery. can be used for

Batteries generally have a limited life and need to be replaced after being used for a long period of time. According to the present invention configured as described above, the bottom surface of the tunnel section is covered with a detachable cover member, and the battery in the tunnel section is arranged below the torque tube. Therefore, in a maintenance pit, the battery can be easily replaced from the underside of the vehicle simply by removing the cover member at the bottom of the vehicle without removing the torque tube or power transmission shaft.

In general, inverters have a longer service life than batteries, so they rarely need to be repaired or replaced. According to the present invention configured as described above, by arranging the inverter above the torque tube in the tunnel, which is difficult to access, the space in the tunnel can be effectively utilized.

The present invention preferably further includes a DC/DC converter for stepping up or stepping down the DC voltage output from the battery, and this DC/DC converter is arranged above the torque tube in the tunnel section.

In general, DC/DC converters have a longer service life than batteries, so they rarely need to be repaired or replaced. According to the present invention configured as described above, by arranging the DC/DC converter above the torque tube inside the tunnel, which is difficult to access, the space inside the tunnel can be effectively utilized.

The present invention preferably further includes a transmission disposed between the left and right rear wheels of the vehicle, and the end of the torque tube on the rear side of the vehicle is attached to the housing of the transmission.

According to the present invention configured as described above, since the end portion of the torque tube on the vehicle rear side is attached to the housing of the transmission, it is possible to increase the rigidity of the vehicle drive system while suppressing an increase in weight. can be done.

In the present invention, the end of the torque tube on the front side of the vehicle is preferably attached to the housing of the prime mover.

According to the present invention configured as described above, since the end portion of the torque tube on the front side of the vehicle is attached to the housing of the prime mover, it is possible to increase the rigidity of the vehicle drive system while suppressing an increase in weight. can.

In the present invention, the prime mover preferably comprises an internal combustion engine and a motor arranged on the rear side of the internal combustion engine, and the end of the torque tube on the front side of the vehicle is attached to the housing of the motor.

The present invention preferably further includes an in-wheel motor provided on a wheel of the vehicle, and a capacitor for accumulating electrical energy supplied to the in-wheel motor, wherein the in-wheel motor is connected in series with Power is supplied from a connected battery and capacitor.

According to the present invention configured as described above, power is supplied to the in-wheel motor from the battery and the capacitor that are connected in series. can be supplied, and the in-wheel motor can be driven with a relatively low current.

In the present invention, preferably, the maximum terminal voltage of the capacitor is higher than the terminal voltage of the battery.

According to the present invention configured in this manner, the maximum voltage across the terminals of the capacitor is set higher than the voltage across the terminals of the battery, so that the voltage supplied to the in-wheel motor is significantly higher than the voltage across the battery terminals. It can be raised and the in-wheel motor can be driven with a low current.

According to the vehicle drive system of the present invention, the battery can be installed without excessively narrowing the vehicle compartment and the cargo loading space while preventing excessive damage to the battery in the event of a vehicle collision or the like.

1 is a layout diagram of a vehicle equipped with a vehicle drive system according to an embodiment of the present invention; FIG. 1 is a top perspective view of a front portion of a vehicle equipped with a vehicle drive system according to an embodiment of the present invention; FIG. 1 is a block diagram showing a power supply configuration of a vehicle drive system according to an embodiment of the invention; FIG. FIG. 4 is a diagram schematically showing an example of voltage change when electric power is regenerated in a capacitor in the vehicle drive system according to the embodiment of the present invention; FIG. 2 is a diagram showing the relationship between the output of each motor and vehicle speed used in the vehicle drive system according to the embodiment of the present invention; 3 is a cross-sectional view schematically showing the structure of a sub-drive motor in the vehicle drive system according to the embodiment of the invention; FIG. 1 is a side view showing a power transmission system in a vehicle drive system according to an embodiment of the present invention; FIG. 1 is a perspective view showing part of a power transmission mechanism in a vehicle drive system according to an embodiment of the present invention and a tunnel part containing the same. FIG. FIG. 8 is a cross-sectional view taken along line IX-IX in FIG. 7 in the vehicle drive system according to the embodiment of the present invention; 1 is a perspective view showing part of a power transmission mechanism in a vehicle drive system according to an embodiment of the invention; FIG.

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.
FIG. 1 is a layout diagram of a vehicle equipped with a vehicle drive system according to an embodiment of the present invention. FIG. 2 is a perspective view of the front part of a vehicle equipped with the vehicle drive system of this embodiment, viewed from above.

As shown in FIG. 1, in a vehicle 1 equipped with a vehicle drive system according to the embodiment of the present invention, an engine 12, which is an internal combustion engine, is mounted in front of the driver's seat and serves as main drive wheels. It is a so-called FR (front engine, rear drive) vehicle that drives a pair of left and right rear wheels 2a. As will be described later, the rear wheels 2a are also driven by a main driving motor, and the pair of left and right front wheels 2b, which are auxiliary driving wheels, are driven by the auxiliary driving motor.

A vehicle drive system 10 according to an embodiment of the present invention mounted on a vehicle 1 includes an engine 12 that drives rear wheels 2a, a power transmission mechanism 14 that transmits driving force to the rear wheels 2a, and a main body that drives the rear wheels 2a. It has a drive motor 16, a battery 18, a secondary drive motor 20 that drives the front wheels 2b, a capacitor 22, and a control device 24 that is a controller.

The engine 12 is an internal combustion engine for generating driving force for the rear wheels 2a, which are the main driving wheels of the vehicle 1. As shown in FIG. As shown in FIG. 2, in this embodiment, an in-line four-cylinder engine is adopted as the engine 12, and the engine 12 arranged in the front part of the vehicle 1 drives the rear wheels 2a through the power transmission mechanism 14. It is designed to

The power transmission mechanism 14 is configured to transmit the driving force generated by the engine 12 and the main drive motor 16 to the rear wheels 2a, which are the main drive wheels. As shown in FIG. 1, the power transmission mechanism 14 includes a propeller shaft 14a, which is a power transmission shaft connected to the engine 12 and the main drive motor 16, and a transmission 14b, which is a speed changer. A detailed configuration of the power transmission mechanism 14 will be described later.

The main drive motor 16 is an electric motor for generating driving force for the main drive wheels, is provided on the vehicle body of the vehicle 1, and is arranged behind the engine 12 and adjacent to the engine 12. It functions as a side motor. An inverter 16 a is arranged adjacent to the main drive motor 16 , and this inverter 16 a converts the DC voltage of the battery 18 into an AC voltage and supplies it to the main drive motor 16 . Further, as shown in FIG. 1, the main drive motor 16 is connected in series with the engine 12, and the driving force generated by the main drive motor 16 is also transmitted to the rear wheels 2a via the power transmission mechanism 14. As shown in FIG. Alternatively, the present invention can be constructed such that the main drive motor 16 is connected to the middle of the power transmission mechanism 14 and the driving force is transmitted to the rear wheels 2a through a part of the power transmission mechanism 14. In this embodiment, a 25 kW permanent magnet motor (permanent magnet synchronous motor) driven at 48 V is employed as the main drive motor 16 .

The battery 18 is primarily a reservoir for storing electrical energy to power the main drive motor 16 . Furthermore, in this embodiment, a 48 V, 3.5 kWh lithium ion battery (LIB) is used as the battery 18 .

Next, as shown in FIG. 2, the sub-driving motor 20 is provided for each of the front wheels 2b under the spring of the vehicle 1 so as to generate driving force for the front wheels 2b, which are the sub-driving wheels. The sub-drive motors 20 are in-wheel motors and housed in the wheels of the front wheels 2b. Also, the DC voltage of the capacitor 22 is converted into an AC voltage by an inverter 20 a ( FIG. 1 ) arranged in the tunnel section 15 and supplied to each sub-drive motor 20 . Furthermore, in this embodiment, the sub-driving motor 20 is not provided with a speed reducer, which is a reduction mechanism, and the driving force of the sub-driving motor 20 is directly transmitted to the front wheels 2b to drive the wheels directly. Further, in this embodiment, a 17 kW induction motor is employed as each sub-driving motor 20 .

A capacitor 22 is provided to store power regenerated by the sub-drive motor 20 . As shown in FIGS. 1 and 2, the capacitor 22 is arranged on the side of the engine 12 and supplies electric power to the auxiliary drive motors 20 provided for the front wheels 2b of the vehicle 1. As shown in FIGS. Furthermore, the capacitor 22 is configured to accumulate electric charge with a voltage higher than that of the battery 18, and is arranged in a region between the left and right front wheels 2b, which are auxiliary drive wheels. The sub-drive motor 20 driven primarily by the power stored in the capacitor 22 is driven at a voltage higher than that of the main drive motor 16 .

As shown in FIG. 1, the control device 24 is configured to control the engine 12, the main drive motor 16, and the sub-drive motor 20 to execute an electric motor drive mode and an internal combustion engine drive mode. Specifically, the control device 24 can be composed of a microprocessor, a memory, an interface circuit, and a program (not shown) for operating them.

Next, the power source configuration of the vehicle drive system 10 according to the embodiment of the present invention and the driving of the vehicle 1 by each motor will be described with reference to FIGS. 3 to 6. FIG.
FIG. 3 is a block diagram showing the power supply configuration of the vehicle drive system 10 according to the embodiment of the invention. FIG. 4 is a diagram schematically showing an example of voltage changes when electric power is regenerated in the capacitor 22 in the vehicle drive device 10 of the present embodiment. FIG. 5 is a diagram showing the relationship between the output of each motor used in the vehicle drive system 10 of this embodiment and the vehicle speed.

As shown in FIG. 3, the battery 18 and the capacitor 22 provided in the vehicle drive system 10 are connected in series. The main drive motor 16 is supplied with power from a battery 18, and the sub-drive motor 20 is supplied with power from a battery 18 and a capacitor 22 that are connected in series. That is, the main drive motor 16 is driven by about 48V, which is the reference output voltage of the battery 18, and the subdrive motor 20 is driven by a voltage higher than 48V, which is the sum of the output voltage of the battery 18 and the voltage between the terminals of the capacitor 22, up to 120V. is driven by a voltage of In this manner, the capacitor 22 accumulates electrical energy to be supplied to the sub-driving motor 20 , and the sub-driving motor 20 is always driven by the power supplied via the capacitor 22 . Thus, the maximum voltage across the terminals of the capacitor 22 is set higher than the voltage across the terminals of the battery 18 .

An inverter 16a is attached to the main drive motor 16, and after converting the output of the battery 18 into an alternating current, the main drive motor 16, which is a permanent magnet motor, is driven. Similarly, each sub-drive motor 20 is connected to an inverter 20a, which converts the output of the battery 18 and capacitor 22 into alternating current to drive the sub-drive motor 20, which is an induction motor.

Further, when the vehicle 1 decelerates or the like, the main drive motor 16 and the sub-drive motors 20 function as generators to regenerate the kinetic energy of the vehicle 1 to generate electric power. Electric power regenerated by the main drive motor 16 is stored in the battery 18 , and electric power regenerated by each sub-drive motor 20 is mainly stored in the capacitor 22 .

A high-voltage DC/DC converter 26a, which is a voltage converter, is connected between the battery 18 and the capacitor 22, and the high-voltage DC/DC converter 26a operates when the charge accumulated in the capacitor 22 is insufficient ( When the voltage across the terminals of the capacitor 22 drops), the voltage of the battery 18 is boosted and the capacitor 22 is charged. On the other hand, when the voltage across the terminals of the capacitor 22 rises above a predetermined voltage due to the regeneration of energy by each sub-drive motor 20, the charge accumulated in the capacitor 22 is stepped down and applied to the battery 18. charge the battery. That is, after the electric power regenerated by the auxiliary drive motor 20 is stored in the capacitor 22, part of the stored charge is charged in the battery 18 via the high voltage DC/DC converter 26a.

Further, a low-voltage DC/DC converter 26b is connected between the battery 18 and the 12V electrical equipment 25 of the vehicle 1. As shown in FIG. Since the control device 24 of the vehicle drive device 10 and many of the electrical components 25 of the vehicle 1 operate at a voltage of 12 V, the charge accumulated in the battery 18 is stepped down to 12 V by the low-voltage DC/DC converter 26b, and these supply the equipment.

Next, referring to FIG. 4, charging and discharging of capacitor 22 will be described.
As shown in FIG. 4, the voltage of capacitor 22 is the sum of the base voltage of battery 18 and the voltage across capacitor 22 itself. During deceleration of the vehicle 1 , electric power is regenerated by each auxiliary drive motor 20 and the regenerated electric power is charged in the capacitor 22 . When the capacitor 22 is charged, the terminal voltage rises relatively rapidly. When the voltage of capacitor 22 rises above a predetermined voltage due to charging, the voltage of capacitor 22 is lowered by high-voltage DC/DC converter 26a, and battery 18 is charged. As shown in FIG. 4, the charging of the battery 18 from the capacitor 22 is performed relatively slowly than the charging of the capacitor 22, and the voltage of the capacitor 22 is relatively slowly lowered to the proper voltage.

That is, the electric power regenerated by each sub-drive motor 20 is temporarily stored in the capacitor 22, and then slowly charged to the battery 18. FIG. Depending on the period during which the regeneration is performed, the regeneration of electric power by each sub-drive motor 20 and the charging of the battery 18 from the capacitor 22 may overlap.
On the other hand, the power regenerated by the main drive motor 16 is directly charged to the battery 18 .

Next, the relationship between the vehicle speed and the output of each motor in the vehicle drive system 10 according to the embodiment of the present invention will be described with reference to FIG. FIG. 5 is a graph showing the relationship between the speed of the vehicle 1 and the output of each motor at each speed in the vehicle drive system 10 of this embodiment. In FIG. 5, the output of the main drive motor 16 is indicated by a dashed line, the output of one sub-drive motor 20 is indicated by a dashed line, the total output of the two sub-drive motors 20 is indicated by a two-dot chain line, and the output of all motors. The total is indicated by a solid line. In FIG. 5, the horizontal axis represents the speed of the vehicle 1 and the vertical axis represents the output of each motor. Even when the number of motor revolutions is set, the output of each motor draws a curve similar to that shown in FIG.

In this embodiment, a permanent magnet motor is used for the main drive motor 16. Therefore, as shown by the dashed line in FIG. As the speed increases, the motor output that can be output decreases. That is, in the present embodiment, the main drive motor 16 is driven at about 48 V and outputs a maximum torque of about 200 Nm up to about 1000 rpm, and the torque decreases as the rotation speed increases above about 1000 rpm. Further, in this embodiment, the main drive motor 16 is configured to obtain a continuous output of about 20 kW in the lowest speed range and a maximum output of about 25 kW.

On the other hand, since the sub-drive motor 20 employs an induction motor, as indicated by the one-dot chain line and the two-dot chain line in FIG. The output increases as the speed increases, and after the maximum output is obtained at a vehicle speed of about 130 km/h, the motor output decreases. In this embodiment, the sub-drive motor 20 is driven at about 120 V and is configured to obtain an output of about 17 kW per unit and a total output of about 34 kW at a vehicle speed of about 130 km/h. That is, in this embodiment, the auxiliary drive motor 20 has a peak torque curve at about 600 to 800 rpm, and a maximum torque of about 200 Nm is obtained.

A solid line in FIG. 5 indicates the total output of the main drive motor 16 and the two sub-drive motors 20 . As is clear from this graph, in this embodiment, a maximum output of about 53 kW is obtained at a vehicle speed of about 130 km/h, and this maximum output at this vehicle speed satisfies the driving conditions required in the WLTP test. be able to. In the solid line in FIG. 5, the output values of the two sub-driving motors 20 are added even in the low vehicle speed range, but in reality the sub-driving motors 20 are not driven in the low vehicle speed range. That is, the vehicle is driven only by the main drive motor 16 when starting and in a low vehicle speed range, and two motors are used only when a large output is required in a high vehicle speed range (such as when accelerating the vehicle 1 in a high vehicle speed range). A secondary drive motor 20 generates an output. In this way, by using the induction motor (sub-drive motor 20) capable of generating a large output in the high rotation range only in the high speed range, the increase in vehicle weight can be kept low and the required (e.g., when accelerating at high speed).

Next, referring to FIG. 6, the configuration of the auxiliary drive motor 20 employed in the vehicle drive system 10 of the embodiment of the invention will be described. FIG. 6 is a cross-sectional view schematically showing the structure of the sub-drive motor 20. As shown in FIG.
As shown in FIG. 6, the sub-drive motor 20 is an outer rotor type induction motor composed of a stator 28 and a rotor 30 rotating around the stator.

The stator 28 has a generally disc-shaped stator base 28a, a stator shaft 28b extending from the center of the stator base 28a, and a stator coil 28c attached around the stator shaft 28b. The stator coil 28c is housed in an electrical insulating liquid chamber 32, and is immersed in an electrical insulating liquid 32a filled therein, thereby boiling and cooling.

The rotor 30 is configured in a generally cylindrical shape so as to surround the stator 28, and includes a rotor body 30a configured in a generally cylindrical shape with one end closed, and a rotor disposed on the inner peripheral wall surface of the rotor body 30a. and a coil 30b. The rotor coil 30b is arranged to face the stator coil 28c so that an induced current is generated by the rotating magnetic field generated by the stator coil 28c. Also, the rotor 30 is supported by a bearing 34 attached to the tip of the stator shaft 28b so as to rotate smoothly around the stator 28. As shown in FIG.

The stator base 28 a is supported by a suspension mechanism (not shown) that suspends the front wheels of the vehicle 1 . On the other hand, the rotor body 30a is directly fixed to a wheel (not shown) of the front wheel 2b. The alternating current converted to alternating current by the inverter 20a is supplied to the stator coil 28c to generate a rotating magnetic field. This rotating magnetic field causes an induced current to flow in the rotor coil 30b, generating a driving force for rotating the rotor body 30a. Thus, the driving force generated by each sub-driving motor 20 directly rotationally drives the wheel (not shown) of each front wheel 2b.

Next, with reference to FIGS. 7 to 10, the configuration of the power transmission mechanism provided in the vehicle drive system according to the embodiment of the invention will be described in detail.
FIG. 7 is a side view showing a power transmission system in the vehicle drive system. FIG. 8 is a perspective view showing a part of the power transmission mechanism and a tunnel part containing it. 9 is a cross-sectional view taken along line IX-IX in FIG. 7. FIG. FIG. 10 is a perspective view showing part of the power transmission mechanism.

As shown in FIG. 7, the power transmission mechanism 14 is configured to transmit power generated by an engine 12 and a main drive motor 16, which are prime movers arranged at the front of the vehicle 1, to the rear wheels 2a. there is The output shafts of the engine 12 and the main drive motor 16 are directly connected, and the output shaft 40 is connected to the propeller shaft 14a. The propeller shaft 14a extends rearward of the vehicle 1, and its rear end is connected to the input shaft 42 of the transmission 14b. In this embodiment, the housing 44 of the transmission 14b also accommodates a clutch and a differential gear (not shown). Therefore, power input to the input shaft 42 of the transmission 14b is output via a clutch, transmission gear, and differential gear (not shown). Furthermore, in this embodiment, the transmission 14b is arranged between the left and right rear wheels 2a, and its output shaft 46 is connected to the axle of the rear wheel 2a to drive the rear wheel 2a.

A propeller shaft 14a connecting the output shaft 40 of the engine 12 and the main drive motor 16 and the input shaft 42 of the transmission 14b is accommodated in a torque tube 14c formed in a cylindrical shape with a circular cross section. . The end of the torque tube 14c on the front side of the vehicle is attached to a housing 48 of a prime mover comprising the engine 12 and the main drive motor 16. As shown in FIG. The end of the torque tube 14c on the vehicle rear side is attached to the housing 44 of the transmission 14b. By fixing both ends of the torque tube 14c to respective housings in this manner, the rigidity of the entire vehicle drive system is increased.

Further, as shown in FIGS. 8 and 9, the propeller shaft 14a and the torque tube 14c containing the propeller shaft 14a are arranged in a tunnel portion 15 (floor tunnel) provided in the lower portion of the vehicle 1. As shown in FIG. The tunnel portion 15 is provided on the bottom surface of the vehicle 1 so as to extend in the front-rear direction in the widthwise center of the vehicle 1 . Further, as shown in FIG. 9, the tunnel portion 15 is formed by bending a metal plate into an approximately inverted U-shaped cross section and fixing the lower ends on both sides to the frame 50 of the vehicle body. Further, a plate-like cover member 52 is detachably fixed to the frame 50 on the bottom surface of the tunnel portion 15 . By removing this cover member 52 , it becomes possible to access the inside of the tunnel portion 15 from the lower side of the vehicle 1 .

Next, referring again to FIG. 10, the arrangement structure in the tunnel section will be described. FIG. 10 is a perspective view showing part of the power transmission mechanism, showing a state in which the members forming the tunnel portion 15 are removed.

As shown in FIG. 9, the propeller shaft 14a and the torque tube 14c covering the propeller shaft 14a pass through the tunnel portion 15, and the battery 18 is arranged below and adjacent to the torque tube 14c. Therefore, the battery 18 housed in the tunnel portion 15 is exposed only by removing the cover member 52 attached to the bottom surface of the tunnel portion 15 . Thereby, the battery 18 in the tunnel portion 15 can be accessed without removing the torque tube 14c and the propeller shaft 14a, and the battery 18 can be easily replaced.

In addition, since the tunnel portion 15 is located substantially in the center of the vehicle 1 in the width direction and also in the intermediate portion in the front-rear direction, the vehicle 1 is not damaged even when the vehicle 1 collides from the front or the rear or from the side. Hard to accept. Furthermore, since the tunnel portion 15 is formed by fixing a bent metal plate to the frame 50 of the vehicle 1, the battery 18 arranged therein is protected by the wall surface of the tunnel portion 15 and is less likely to be damaged. . A propeller shaft 14a that rotates during running passes above the battery 18 in the tunnel portion 15, and this propeller shaft 14a is housed in a torque tube 14c. Therefore, when a running vehicle collides, the rotating propeller shaft 14a may deform and bend, but the risk of damage to the battery 18 is small. That is, since the propeller shaft 14a is accommodated in the torque tube 14c, even if the rotating propeller shaft 14a is bent, the risk of direct contact and damage to the battery 18 accommodated nearby is extremely small.

In this embodiment, the transmission 14b has a so-called transaxle arrangement. As a result, the body of the transmission having a large outer diameter does not exist immediately after the engine 12 (and the main drive motor 16), so the width of the tunnel portion 15 can be reduced, and the passenger's central leg space can be increased. It is possible to secure the occupant so that the occupant can take a symmetrical lower body posture facing the front. Furthermore, it becomes easy to make the outer diameter and length of the main drive motor 16 large enough according to the output while ensuring the posture of the passenger. In addition, since the transaxle arrangement is adopted in this embodiment, the volume for accommodating the battery 18 can be expanded toward the space in front of the tunnel portion 15 created thereby. As a result, the capacity of the battery 18 can be secured and expanded without narrowing the space on the central side of the occupant by increasing the width of the floor tunnel.

Further, as shown in FIG. 10 , an inverter 16 a for the main drive motor 16 is arranged above the housing 48 of the main drive motor 16 and accommodated in the tunnel portion 15 . Furthermore, an inverter 20a for the sub-drive motor 20, a high-voltage DC/DC converter 26a, and a low-voltage DC/DC converter 26b are arranged in order from the front side of the vehicle 1 above the torque tube 14c. Contained. These inverter 16a, inverter 20a, high-voltage DC/DC converter 26a, and low-voltage DC/DC converter 26b are arranged above the torque tube 14c. hard to do. However, each inverter and each DC/DC converter has a relatively long service life and rarely requires replacement or repair. Therefore, the upper space in the tunnel portion 15 can be effectively utilized without greatly impairing maintainability.

According to the vehicle drive system 10 of the embodiment of the invention, the battery 18 is arranged in the tunnel portion 15 under the vehicle 1 (Fig. 9). Here, the tunnel portion 15 is relatively resistant to deformation when the vehicle 1 collides from the front, side, or rear. Therefore, by arranging the battery 18 in the tunnel portion 15, damage to the battery 18 can be effectively avoided even when the vehicle 1 collides. In addition, by arranging the battery 18 in the tunnel portion 15, there is a risk that the battery 18 will be damaged by an impact from the outside of the tunnel portion 15 without providing a special protective member for preventing damage to the battery 18. can be effectively suppressed. Thereby, the battery 18 can be protected while suppressing an increase in size.

Further, a propeller shaft 14a, which is a power transmission shaft for transmitting the output of the prime mover (engine 12 and main drive motor 16) to the rear wheels 2a of the vehicle 1, extends in the tunnel portion 15. As shown in FIG. Since the propeller shaft 14a rotates while the vehicle 1 is running, if the propeller shaft 14a is deformed due to a collision of the vehicle 1 during running, the rotating propeller shaft 14a is placed in the tunnel portion 15. It is conceivable that the battery 18 may be damaged by interfering with the installed battery 18 . However, in the vehicle drive system 10 of the present embodiment, the propeller shaft 14a is housed inside the tubular torque tube 14c. Direct interference can prevent the battery 18 from being damaged. In addition, since the propeller shaft 14a is accommodated in the torque tube 14c, the battery 18 can be arranged adjacent to the torque tube 14c while ensuring sufficient safety, and the space inside the tunnel portion 15 can be reduced. It can be effectively used for housing the battery 18 .

Furthermore, according to the vehicle drive device 10 of the present embodiment, the bottom surface of the tunnel portion 15 is covered with the detachable cover member 52, and the battery 18 inside the tunnel portion 15 is arranged below the torque tube 14c. there is Therefore, in the maintenance pit, the battery 18 can be easily replaced from the underside of the vehicle 1 simply by removing the cover member 52 at the bottom of the vehicle 1 without removing the torque tube 14c or the propeller shaft 14a.

Further, according to the vehicle drive system 10 of the present embodiment, the inverter 16a, the inverter 20a, the high-voltage DC/DC converter 26a, and the low-voltage DC/DC converter 26b are arranged above the torque tube 14c in the tunnel portion 15, which is difficult to access. By arranging them (FIG. 10), the space in the tunnel portion 15 can be effectively utilized.

Furthermore, according to the vehicle drive system 10 of the present embodiment, since the end of the torque tube 14c on the rear side of the vehicle 1 is attached to the housing 44 of the transmission 14b (FIG. 7), while suppressing an increase in weight, The rigidity of the vehicle drive system can be increased.

Further, according to the vehicle drive system 10 of the present embodiment, since the end portion of the torque tube 14c on the front side of the vehicle 1 is attached to the housing of the main drive motor 16, which is the prime mover (FIG. 7), an increase in weight can be avoided. It is possible to increase the rigidity of the vehicle drive system while suppressing it.

Furthermore, according to the vehicle drive system 10 of the present embodiment, power is supplied from the battery 18 and the capacitor 22 connected in series to the auxiliary drive motor 20, which is an in-wheel motor (FIG. 3), so that the voltage is relatively low. battery 18, a high voltage can be supplied to the sub-driving motor 20, and the sub-driving motor 20 can be driven with a relatively low current.

Further, according to the vehicle drive system 10 of the present embodiment, the maximum voltage across the terminals of the capacitor 22 is higher than the voltage across the terminals of the battery 18 (FIG. 4). The voltage between the terminals of the battery 18 can be greatly increased, and the sub-drive motor 20 can be driven with a low current.

Although preferred embodiments of the present invention have been described above, various modifications can be made to the above-described embodiments. In particular, in the above-described embodiments, the present invention is applied to a so-called hybrid vehicle drive system having an engine and a motor for driving a vehicle. The present invention can also be applied to a vehicle drive system in which a is driven. Further, in the above-described embodiments, the power of the engine and/or the main drive motor is transmitted by the propeller shaft, which is the power transmission shaft. The present invention can also be applied to a vehicle drive system that

Furthermore, in the above-described embodiments, the prime mover is composed of the engine and the main drive motor, and the output shaft of the main drive motor is connected to the propeller shaft. However, when the engine is arranged on the rear side of the motor, or when only the power of the engine is transmitted by the propeller shaft, the output shaft of the engine can also be connected to the propeller shaft. Further, in the above-described embodiments, the end of the torque tube on the front side of the vehicle is attached to the housing of the main drive motor. However, if the engine is located behind the motor, or if only the power of the engine is transmitted by the propeller shaft, the torque tube can be attached to the engine housing.

Furthermore, in the above-described embodiment, the output shaft of the prime mover is connected to the propeller shaft. can also be configured.

1 vehicle 2a rear wheel (main driving wheel)
2b front wheel (secondary drive wheel)
10 vehicle driving device 12 engine (motor, internal combustion engine)
14 power transmission mechanism 14a propeller shaft (power transmission shaft)
14b transmission
14c torque tube 15 tunnel section 16 main drive motor (prime mover, motor)
16a Inverter 18 Battery (accumulator)
20 sub-drive motor (in-wheel motor)
20a Inverter 22 Capacitor 24 Control device (controller)
25 Electrical equipment 26a High voltage DC/DC converter (voltage converter)
26b Low-voltage DC/DC converter 28 Stator 28a Stator base 28b Stator shaft 28c Stator coil 30 Rotor 30a Rotor body 30b Rotor coil 32 Electrical insulating liquid chamber 32a Electrical insulating liquid 34 Bearing 40 Output shaft 42 Input shaft 44 Housing 46 Output shaft 48 Housing 50 frame 52 cover member

Claims (7)

A driving device for a vehicle equipped with a battery,
a prime mover disposed at the front of the vehicle;
a power transmission shaft that transmits the output of the prime mover to the rear wheels of the vehicle;
a cylindrical torque tube accommodating the power transmission shaft inside;
a battery storing electrical energy for driving the vehicle;
The torque tube is arranged in a tunnel portion provided in the lower part of the vehicle so as to extend in the longitudinal direction of the vehicle, and the battery is arranged in the tunnel portion so as to be adjacent to the torque tube. ,
The bottom surface of the tunnel portion is covered with a detachably attached cover member, and the battery is arranged below the torque tube in the tunnel portion and can be replaced by removing the cover member. can
The vehicle drive device further comprises an inverter for converting a DC voltage output from the battery into an AC voltage, the inverter being arranged above the torque tube in the tunnel section . A driving device for a vehicle equipped with a battery,
a prime mover disposed at the front of the vehicle;
a power transmission shaft that transmits the output of the prime mover to the rear wheels of the vehicle;
a cylindrical torque tube accommodating the power transmission shaft inside;
a battery storing electrical energy for driving the vehicle;
The torque tube is arranged in a tunnel portion provided in the lower part of the vehicle so as to extend in the longitudinal direction of the vehicle, and the battery is arranged in the tunnel portion so as to be adjacent to the torque tube. ,
The bottom surface of the tunnel portion is covered with a detachably attached cover member, and the battery is arranged below the torque tube in the tunnel portion and can be replaced by removing the cover member. can
Further, a DC/DC converter for stepping up or stepping down the DC voltage output from the battery is provided, and the DC/DC converter is arranged above the torque tube in the tunnel section . vehicle drive. 3. The vehicle according to claim 1, further comprising a transmission disposed between left and right rear wheels of the vehicle, wherein the end of the torque tube on the rear side of the vehicle is attached to a housing of the transmission. vehicle drive. 4. The vehicle drive system according to any one of claims 1 to 3 , wherein a vehicle front end of the torque tube is attached to a housing of the prime mover. 5. A vehicle according to claim 4 , wherein said prime mover comprises an internal combustion engine and a motor disposed on the rear side of said internal combustion engine, and said torque tube has a front end of said torque tube attached to a housing of said motor. drive. and a capacitor for accumulating electric energy supplied to the in-wheel motor, and the battery connected in series to the in-wheel motor. 6. The vehicle drive system according to claim 1 , wherein power is supplied from said capacitor and said capacitor. 7. The vehicle drive system according to claim 6 , wherein the maximum voltage across the terminals of the capacitor is higher than the voltage across the terminals of the battery.

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