JP2007331632A - Vehicle driving device and system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle driving device capable of exerting a great driving force in starting and the like by a comparatively small motor and allowing regeneration by a motor in a high speed area. <P>SOLUTION: A gear shift mechanism 8 is connected to an output shaft of a power generator 9 and provided with at least two types of gear ratios. One shaft of a coupling means 7 is connected to an output shaft of the gear shift mechanism 8. A clutch 6, in which one shaft is connected to the other shaft of the coupling means 7 while the other shaft is connected to an output shaft of an engine 5, can connect the coupling means 8 and the engine 5 together and can release the connection between them. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle drive device and a vehicle drive system, and more particularly, to a vehicle drive device and a vehicle drive system suitable for use in a hybrid vehicle that combines an internal combustion engine and an electric motor.

  In recent years, various hybrid vehicles combining an internal combustion engine and an electric motor have been developed. Typical methods include a parallel hybrid method in which the power of the internal combustion engine and the electric motor are independently transmitted to the drive wheels, a series hybrid method in which the generator is driven by the internal combustion engine, and the electric motor is driven by the generated electric power, and A series / parallel system in which the two systems are combined so that the fuel consumption is optimized for each operation state of the vehicle can be mentioned.

  Hybrid vehicles are attracting attention as environmentally friendly vehicles with low fuel consumption compared to vehicles using only an internal combustion engine as a drive source. Thus, although the performance of the hybrid vehicle is superior to that of the conventional internal combustion engine vehicle, on the other hand, new electric components are added in addition to the drive mechanism of the internal combustion engine, so that it is manufactured compared to the internal combustion engine vehicle. There is a problem that the cost increases and the space on the vehicle is also pressed.

  In order to reduce the cost, it is an effective means to make a hybrid by using as much as possible the drive mechanism of the internal combustion engine vehicle that is already in widespread use. As a configuration example of such a hybrid vehicle, the driving force of the internal combustion engine is transmitted to an electric motor through a clutch, and this electric motor is used to add power when the output of the internal combustion engine is insufficient, such as at the time of starting. A BAS hybrid is known that can drive and regenerate energy by being driven from the drive wheel side when the vehicle decelerates (see, for example, Patent Document 1). The BAS hybrid has a relatively simple structure in which an electric motor is connected to an internal combustion engine via a belt mechanism, and has a structure in which a drive mechanism designed with an existing internal combustion engine can be easily used.

Japanese Patent Laid-Open No. 2005-147404

  However, the method described in Patent Document 1 is a configuration in which the internal combustion engine and the electric motor are always interlocked together, and when the rotation speed ratio of the electric motor is small with respect to the internal combustion engine, for example, the large required when starting the vehicle. In order to obtain a driving force, an electric motor having a large torque, a power converter capable of flowing a large current, and a battery (power source) corresponding to the large current are required. As a result, the entire apparatus mounted on the vehicle becomes very large, heavy and expensive. Therefore, it is not preferable in terms of securing an effective space of the vehicle, fuel consumption, and power performance. In particular, the fuel supply was stopped while the vehicle was stopped, such as waiting for a signal. After that, when the accelerator pedal was depressed, the internal combustion engine was restarted and the vehicle started to start with the driving force of the electric motor. When applying so-called idle stop technology, the vehicle must be moved only by the driving force of the electric motor for a short period of time immediately after starting, so the size of the electric motor greatly affects the starting performance.

  On the other hand, even if the internal combustion engine and the electric motor are always integrated together, if the rotational speed ratio of the electric motor is large with respect to the internal combustion engine, even if a large driving force is required as in starting The electric motor may generate a relatively small torque, and the power conversion circuit and the battery may have a small current capacity. Therefore, the device mounted on the vehicle is downsized. However, in such a case, when the vehicle travels at a high speed, the motor rotates excessively at a high speed, which may exceed the allowable rotational speed. In addition, if a clutch mechanism is interposed and the motor is disconnected at high speeds, the motor can be protected, but energy regeneration during deceleration can only be started when the vehicle speed has decreased to some extent, which is preferable in terms of energy efficiency. Absent.

  An object of the present invention is to provide a vehicle drive device that can exert a large driving force when starting with a relatively small electric motor and that can be regenerated by the electric motor in a high speed range.

(1) In order to achieve the above object, the present invention is a vehicle drive device having a generator motor that is driven by an engine and operates as a generator and that operates as an electric motor that generates a driving force by supplied power. A transmission mechanism coupled to the output shaft of the generator motor and having at least two types of gear ratios, a coupling means connected to one shaft to the output shaft of the transmission mechanism, and a coupling mechanism connected to the other shaft of the coupling means One shaft is coupled, the other shaft is coupled to the output shaft of the engine, and the coupling means and a clutch capable of coupling and releasing the coupling of the engine are provided.
With such a configuration, a large driving force can be exerted with a relatively small electric motor at the time of starting and the like, and regeneration by the electric motor in a high speed range is possible.

  (2) In the above (1), preferably, the transmission is connected to the output shaft of the engine, and the clutch is connected to an end opposite to one end of the output shaft to which the transmission is connected. It is.

  (3) In the above (1), preferably, the generator motor and the shaft of the speed change mechanism are arranged in parallel to the output shaft of the engine.

(4) In order to achieve the above object, the present invention is a vehicle drive device having a generator motor that is driven by an engine and operates as a generator and that also operates as a motor that generates a driving force by the supplied power. An acceleration / deceleration mechanism coupled to the output shaft of the generator motor and having at least two types of acceleration / deceleration ratios; one shaft connected to the output shaft of the acceleration / deceleration transmission mechanism; And a clutch capable of coupling and releasing the coupling of the engine and the engine.
With such a configuration, a large driving force can be exerted with a relatively small electric motor at the time of starting and the like, and regeneration by the electric motor in a high speed range is possible.

(5) Further, in order to achieve the above object, the present invention is a generator motor that is driven by an engine and operates as a generator, and operates as a motor that generates a driving force by the supplied power, and the generator motor. A vehicle drive system having control means for controlling the transmission, wherein the transmission mechanism is connected to the output shaft of the generator motor and has at least two speed ratios, and one shaft is connected to the output shaft of the transmission mechanism. A coupling means; and a clutch connected to the other shaft of the coupling means, the other shaft being connected to the output shaft of the engine, and a clutch capable of coupling and releasing the coupling of the coupling means and the engine. And the control means controls the power regeneration of the generator motor, the gear ratio of the speed change mechanism, and the coupling release of the clutch according to the driving state of the vehicle. Those were.
With such a configuration, a large driving force can be exerted with a relatively small electric motor at the time of starting and the like, and regeneration by the electric motor in a high speed range is possible.

  (6) In the above (5), preferably, when the vehicle speed is low, the control means sets the speed change mechanism so that the output torque of the generator motor is reduced and transmitted to the engine. The speed ratio is controlled, and when the vehicle is in a decelerating state, the speed ratio of the speed change mechanism is controlled so that the rotational speed of the generator motor is larger than the speed of the engine.

  According to the present invention, with a relatively small electric motor, a large driving force can be exhibited at the time of starting and the like, and regeneration by the electric motor in a high speed range is possible.

Hereinafter, the configuration and operation of the vehicle drive device according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2.
First, the configuration and operation of the vehicle drive apparatus according to the present embodiment will be described with reference to FIG. In this example, as an example of a vehicle drive device, an overall configuration in the case of application to a hybrid power transmission mechanism using an internal combustion engine and an electric motor as a drive source is shown.
FIG. 1 is a system block diagram showing a configuration of a hybrid vehicle using a vehicle drive device according to an embodiment of the present invention.

  The hybrid power transmission mechanism includes a pair of drive wheels 1, 2, a differential gear 3, a transmission (T / M) 4, an internal combustion engine 5, a clutch 6, a connecting means 7, a speed change mechanism 8, and a generator motor. (M / G) 9, a power converter 10, and a storage battery 11 are provided. The connecting means 7 and the speed change mechanism 8 constitute the speed increasing / decreasing mechanism 20.

  One output shaft of the engine 5 is connected to the transmission 4. The transmission 4 can be any of several variable ratio transmission designs such as a transmission incorporating a planetary gear mechanism, a belt-type continuously variable transmission so-called CVT, or a manual transmission incorporating a plurality of gear trains to be fitted. Is.

  The output of the engine 5 is shifted by the transmission 4 and transmitted to the drive wheels 1 and 2 via the differential gear 3. The output of the engine 5 is controlled by an engine control unit (ECU) 110. The transmission ratio of the transmission 4 is controlled by a transmission control unit (TCU) 120. ECU 110 and TCU 120 are connected by a communication line and exchange data signals and command signals. ECU 110 and TCU 120 may be configured integrally.

  The other output shaft of the engine 5 is connected to the coupling means 7 via the clutch 7. The clutch 6 is an electromagnetic clutch or other selectively engageable clutch. On / off of the clutch 6 is controlled by a motor control unit (MCU) 100. The connecting means 7 is composed of two pulleys 7a and 7c and a transmission mechanism 7b composed of a belt or a chain. The transmission shaft of the pulley 7 a is connected to the clutch 6, and the transmission shaft of the pulley 7 c is connected to one shaft of the transmission mechanism 8.

  The transmission mechanism 8 is a mechanism having at least two transmission ratios. One shaft of the speed change mechanism 8 is connected to the connecting means 7, and the other shaft is connected to the generator motor (M / G) 9. The transmission ratio of the transmission mechanism 8 is controlled by a motor control unit (MCU) 100. The MCU 100 switches the speed ratio of the speed change mechanism 8 according to the traveling state of the vehicle.

  The other shaft of the speed change mechanism 8 is connected to a generator motor (M / G) 9. The generator motor 9 is driven by the engine 5 and operates as a generator, and also operates as an electric motor to assist the drive of the engine 5.

  The generator motor 9 is controlled by a motor control unit (MCU) 100. The MCU 100 controls the power converter 10 to convert the direct current of the storage battery 11 into a three-phase alternating current to vary the armature current supplied to the generator motor 9 and to control the driving torque of the generator motor 9. When the generator motor 9 is operating as a generator, the MCU 100 controls the power converter 10 to convert the output current of the generator into a direct current and stores it in the storage battery 11. Further, the MCU 100 controls the field current that flows through the field winding of the generator motor 9. The MCU 100 and the ECU 110 are connected by a communication line and exchange data signals and command signals. The vehicle speed signal V detected by the vehicle speed sensor 102 is input to the MCU 100 as a signal indicating the state of the vehicle. Further, the accelerator opening signal θth detected by the accelerator opening sensor 104 is input as a signal indicating the driver's intention.

  Next, the operation of the hybrid power transmission mechanism of this embodiment will be described based on a specific example. For example, the maximum practical rotational speed of the engine 5 is set to 6000 rpm, and the maximum practical rotational speed of the generator motor 9 is set to 3000 rpm. Here, the maximum practical rotational speed is given from the operating range in which the loss of the generator motor and the power converter can be kept low. The maximum output torque of the generator motor 9 is a small one of about 10 kW at maximum.

  The reduction ratio of the connecting means 7 is 2, and the rotational speed of the pulley 7a is reduced to 1/2 and transmitted to the pulley 7c. The speed change mechanism 8 has two types of speed ratios 1: 1 and 1: 6. When the transmission ratio is 1: 1, the rotation speed of the transmission shaft of the pulley 7c and the output shaft of the generator motor 9 are the same. In the case of the gear ratio 1: 6, the rotational speed of the transmission shaft of the pulley 7c is increased six times and transmitted to the output shaft of the generator motor 9. Here, regarding the acceleration / deceleration ratio of the acceleration / deceleration mechanism 20, there are two types: 2: 1 and 1: 3. When the transmission gear ratio of the transmission mechanism 8 is 1: 1, the increase / decrease ratio of the acceleration / deceleration mechanism 20 is 2: 1. When the transmission gear ratio of the transmission mechanism 8 is 1: 6, the acceleration / deceleration ratio of the acceleration / deceleration mechanism 20 is 1: 3. When the speed increasing / decreasing ratio of the speed increasing / decreasing mechanism 20 is 2: 1, the rotational speed of the transmission shaft of the pulley 7a is reduced to 1/2 and transmitted to the output shaft of the generator motor 9. That is, when the generator motor 9 rotates at 3000 rpm, the engine 5 rotates at 6000 rpm. Further, when the speed increasing / decreasing ratio of the speed increasing / decreasing mechanism 20 is 1: 3, the rotational speed of the transmission shaft of the pulley 7 a is increased three times and transmitted to the output shaft of the generator motor 9. That is, when the engine 5 rotates at 1000 rpm, the generator motor 9 rotates at 3000 rpm. The above numerical values are merely examples, and can be arbitrary numerical values according to the characteristics of the engine 5 and the generator motor 9.

  The MCU 100 determines the vehicle speed based on the vehicle speed signal V detected by the vehicle speed sensor 102. For example, when the vehicle speed is 20 km / h or less, such as when starting or at low speed, the MCU 100 sets the gear ratio of the transmission mechanism 8 to 1: 6. The clutch 6 is turned on. As a result, the acceleration / deceleration ratio of the acceleration / deceleration mechanism 20 becomes 1: 3, and when the generator motor 9 rotates at 3000 rpm, the engine 5 rotates at 1000 rpm. At the time of starting, the engine 5 gradually increases from an idle rotation speed (for example, 600 rpm), and therefore the MCU 100 increases the rotation speed of the generator motor 9 accordingly. When the generator motor 9 is used as an electric motor, the torque increases by decelerating the rotation speed of the electric motor via the speed increasing / decreasing mechanism 20. In the above example, by setting the speed increasing / decreasing ratio of the speed increasing / decreasing mechanism 20 to 1: 3, the rotational speed of the generator motor 9 is reduced to 1/3 and transmitted to the engine 5, so that the output torque of the generator motor 9 is increased. Is augmented and transmitted. Therefore, even when a small generator motor 9 having a low output torque is used, the vehicle can be driven by the increased output torque of the generator motor 9 in addition to the output torque of the engine 5, so that at the time of starting and at a low speed Acceleration can be improved.

  On the other hand, when the vehicle speed becomes 20 km / h or more, the MCU 100 sets the acceleration / deceleration ratio of the acceleration / deceleration mechanism 20 to 1: 1. As a result, the rotational speed of the generator motor 9 is doubled and transmitted to the engine 5. At this time, since the rotational speed of the engine 5 is also increased and the rotational speed of the generator motor 9 is also increased, the output torque of the generator motor 9 is small and the effect of torque assist is small, but for example, when the vehicle is in a deceleration state, The generator motor 9 is driven by the engine 5 and can recharge the storage battery 11 by performing a regenerative operation. At this time, the MCU 100 can give a command as a generator to the generator motor 9 and can apply braking torque to the engine. Note that the deceleration state of the vehicle can be determined by the differential value of the vehicle speed signal V being negative, or by a signal indicating that the pedal from the brake pedal has been depressed. When the vehicle is in a high speed state (for example, 100 km / h or more), the generator motor 9 is rotated by the engine 5 and a loss of driving torque of the engine 5 occurs, so the MCU 100 turns off the clutch 6.

  When the idle stop is employed, when the vehicle is stopped, the engine 5 is stopped and then restarted, the MCU 100 sets the transmission gear ratio of the transmission mechanism 8 to 1: 6 and the clutch 6 is turned on. And As a result, the acceleration / deceleration ratio of the acceleration / deceleration mechanism 20 is 1: 3, and the output torque of the generator motor 9 is increased and transmitted, so that the engine 5 can be restarted. The restart condition of the engine 5 can be determined, for example, by detecting that the vehicle speed signal V is 0 km / h and the accelerator pedal is depressed by the accelerator opening signal θth.

Next, an example of the configuration of the speed change mechanism 8 used in the vehicle drive device according to the present embodiment will be described with reference to FIG.
FIG. 2 is a skeleton diagram showing the configuration of the speed change mechanism used in the vehicle drive apparatus according to the embodiment of the present invention.

  The transmission mechanism 8 includes a sun gear member 8a, a ring gear member 8c, a planetary gear member 8b, a carrier member 8d, a clutch 8e. 8f (each electromagnetic clutch or other selectively engageable clutch).

  The sun gear member 8a, the ring gear member 8c, and the planetary gear member 8b mesh with each other. The planetary gear member 8b is a plurality of pinion gears rotatably attached to the carrier member 8d. The carrier member 8d is connected to the rotating shaft 9a of the electric motor 9. Further, one shaft of the clutch 8e is connected to the ring gear member 8c, and the other shaft is connected to the carrier member 8d. One shaft of the clutch 8f is connected to the ring gear member 8c, and the other shaft is connected to the stator 9b of the generator motor 9.

  In a state where the clutch 8e is engaged and the clutch 8f is released, the transmission shaft 7f of the connecting means 7 and the rotating shaft 9a of the electric motor 9 rotate together. In a state where the clutch 8e is released and the clutch 8f is connected, the rotational angular velocity of the transmission shaft 7f of the connecting means 7 and the rotational angular velocity of the rotational shaft 9a of the electric motor 9 have a speed ratio defined in advance by the planetary gear mechanism 8. It rotates with it. That is, the transmission mechanism 8 functions as a two-stage transmission mechanism by connecting and disconnecting the clutches 8e and 8f.

  Here, as the speed change mechanism 8, it is preferable to use a belt-type continuously variable speed change mechanism, so-called CVT, which preferably uses a stepped transmission using a planetary gear mechanism as shown in FIG. Any gear ratio can be used as long as it can change two or more gear ratios.

  Further, as shown in FIG. 1, the connecting means 7 can be constituted by two fitting gears in addition to the pulley and the belt or the chain.

As described above, according to the present embodiment, by providing a speed change mechanism between the internal combustion engine and the electric motor, it is possible to exert a sufficiently large driving force at the time of starting or the like with a relatively small electric motor. In addition, it is possible to prevent the motor from over-rotating during high-speed traveling and to perform energy regeneration during deceleration from a high-speed range. Therefore, it is possible to reduce the size and weight of the entire apparatus including the power conversion circuit and the battery.

1 is a system block diagram showing a configuration of a hybrid vehicle using a vehicle drive device according to an embodiment of the present invention. It is a skeleton figure which shows the structure of the transmission mechanism used for the vehicle drive device by one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Drive wheel 2 ... Drive wheel 3 ... Differential gear 4 ... Transmission 5 ... Internal combustion engine 6 ... Clutch 7 ... Connection means 8 ... Transmission mechanism 9 ... Electric motor 10 ... Power converter 11 ... Storage battery 20 ... Increase / decrease mechanism 100 ... MCU
102 ... Vehicle speed sensor 104 ... Accelerator opening sensor 110 ... ECU
120 ... TCU

Claims (6)

A vehicle drive device having a generator motor that is driven by an engine and operates as a generator and that operates as an electric motor that generates a driving force by supplied power,
A speed change mechanism coupled to the output shaft of the generator motor and having at least two speed ratios;
Connecting means for connecting one shaft to the output shaft of the speed change mechanism;
One shaft is connected to the other shaft of the connecting means, the other shaft is connected to the output shaft of the engine, and the clutch includes a clutch capable of coupling and releasing the connection of the connecting means and the engine. A vehicle drive device. In the vehicle drive device according to claim 1,
The vehicle drive device, wherein the clutch is connected to an end of the output shaft to which the transmission is connected, opposite to one end of the output shaft to which the transmission is connected. In the vehicle drive device according to claim 1,
A vehicle drive device, wherein the generator motor and the shaft of the speed change mechanism are arranged in parallel to the output shaft of the engine. A vehicle drive device having a generator motor that is driven by an engine and operates as a generator and that operates as an electric motor that generates a driving force by supplied power,
An acceleration / deceleration mechanism coupled to the output shaft of the generator motor and having at least two types of acceleration / deceleration ratios;
One shaft is coupled to the output shaft of the speed increasing / decreasing speed change mechanism, the other shaft is coupled to the output shaft of the engine, and the coupling means and a clutch capable of coupling and releasing the coupling of the engine are provided. A vehicle drive device characterized by the above. A vehicle drive system having a generator motor that is driven by an engine and operates as a generator and that operates as an electric motor that generates a driving force by supplied power, and a control unit that controls the generator motor,
A speed change mechanism coupled to the output shaft of the generator motor and having at least two speed ratios;
Connecting means for connecting one shaft to the output shaft of the speed change mechanism;
One shaft is coupled to the other shaft of the coupling means, the other shaft is connected to the output shaft of the engine, and the coupling means and a clutch capable of coupling and releasing the coupling of the engine,
The vehicle drive system according to claim 1, wherein the control means controls power generation regeneration of the generator motor, a gear ratio of the speed change mechanism, and coupling release of the clutch in accordance with a driving state of the vehicle. The vehicle drive device according to claim 5, wherein
The control means controls the speed ratio of the speed change mechanism so that when the vehicle speed is low, the output torque of the generator motor becomes a speed ratio transmitted by decelerating to the engine;
A vehicle drive system that controls a speed ratio of the speed change mechanism so that the rotational speed of the generator motor is larger than the speed of the engine when the vehicle is decelerating.

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