JP4986677B2 - Hybrid vehicle - Google Patents

Description

  The present invention relates to a hybrid vehicle that is mounted with two types of power sources, that is, an electric motor and an internal combustion engine, and that travels with the driving force of each.

  Conventionally, a hybrid vehicle equipped with two types of power sources, an electric motor and an internal combustion engine, is known. In such a hybrid vehicle, there are two systems: a transmission system that transmits the driving force (torque) of the electric motor to the drive shaft, that is, the propeller shaft, and a transmission system that transmits the driving force of the internal combustion engine to the propeller shaft via the transmission. A configuration having a transmission system of is generally used. A clutch is disposed between the internal combustion engine and the transmission, and the clutch is intermittently connected to selectively transmit the driving force of the internal combustion engine to the drive wheels.

In the hybrid vehicle having such a configuration, for example, in the one described in Patent Document 1, in order to improve the performance of fuel consumption and emission, when the vehicle speed is low during traveling at a reduced speed or when the vehicle is traveling by an electric motor. The clutch is disengaged and the internal combustion engine is idling.
JP-A-9-224303

  By the way, when the internal combustion engine is set to the idling operation in a configuration like that of Patent Document 1, that is, when running by an electric motor, the following problems occur. That is, when the clutch is connected, it may take time to synchronize the transmission and the internal combustion engine. This is a problem of responsiveness of the internal combustion engine, and is caused because the rotation of the internal combustion engine is slow after idling operation. Further, when the auxiliary machine is driven by the internal combustion engine, there is a possibility that the idling operation and the driving state cannot be maintained. Particularly in an internal combustion engine with a small displacement, depending on the load of the auxiliary machine, that is, for example, when a compressor of an air conditioner (hereinafter referred to as an air conditioner) becomes a load, the internal combustion engine may stop. . Furthermore, during the idling operation, since the intake pressure is substantially constant, it is difficult to secure a negative pressure for braking.

  Therefore, the present invention aims to eliminate such problems.

That is, the hybrid vehicle of the present invention can generate a driving force according to traveling and also function as a generator, an internal combustion engine that can drive an auxiliary machine and generate driving force according to traveling, A joint device including a drive shaft for transmitting a drive force to the drive wheels, a first transmission system for transmitting the drive force of the electric motor to the drive shaft, and a joint device disposed between the transmission and the transmission and the internal combustion engine. When the second transmission system that transmits the driving force of the internal combustion engine to the drive shaft via the transmission and the driving force of the electric motor that is transmitted to the drive wheels via the first transmission system when traveling, An electric motor driving force control means for controlling the electric motor to output a driving force necessary for traveling, and an input side of the transmission when traveling by transmitting the driving force of the electric motor to the driving wheels via the first transmission system. The rotational speed of the rotary shaft is detected, and the internal combustion engine is converted to the detected rotational speed. By operating the throttle opening such that the rotational speed is substantially equal to control the engine output of the internal combustion engine, the driving force of the internal combustion engine despite a state connecting the coupling device of the second transmission system of the drive wheel And an engine output control means that does not contribute to traveling by rotation.

  According to such a configuration, when traveling by transmitting the driving force of the electric motor to the driving wheels, the coupling device of the second transmission system is connected, and the engine output control means changes the engine speed of the internal combustion engine to that of the transmission. Since the engine output is controlled so as to be the rotational speed of the input-side rotary shaft, the rotational speeds on the input side and the output side of the joint device are substantially matched. In such a state, when switching from traveling by the electric motor to traveling by the electric motor and the internal combustion engine, there is no need to perform a synchronization process for adjusting the rotational speeds of the input side and the output side of the joint device, and the internal combustion engine can be quickly operated. It becomes possible to add a driving force.

  In addition, when the vehicle is running, the rotational speed of the input-side rotary shaft of the transmission is higher than the idle rotational speed of the internal combustion engine, so that the operation of the internal combustion engine is prevented from stopping even when the auxiliary machine is loaded. Is possible. In addition, it is easy to secure the brake negative pressure during deceleration.

  The present invention is configured as described above, and when traveling by transmitting the driving force of the electric motor to the driving wheel, the rotational speed on the input side and the output side of the joint device is made to substantially coincide with each other by the electric motor. When switching from traveling to traveling by an electric motor and an internal combustion engine, it is not necessary to perform a synchronization process for matching the rotational speeds of the input side and output side of the joint device, and the driving force of the internal combustion engine can be quickly added. it can.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  The hybrid vehicle of this embodiment includes an internal combustion engine 1 and an electric motor 2 that generate driving force required for traveling, a drive shaft 4 connected to the drive wheels 3, and a first that transmits the drive force of the electric motor 2 to the drive shaft 4. A transmission system 5, a second transmission system 6 that transmits the driving force of the internal combustion engine 1 to the drive shaft 4, an electric motor control device 7 that controls the rotation and power generation of the electric motor 2, and an electronic control that controls the operation of the internal combustion engine 1 Device 8. Further, a battery 9 as a power source of the electric motor 2, a charger 10 that generates charging power from power from a household outlet, that is, a power line, for example, a headlamp or electronic control for charging the battery 9 during long-time parking A low voltage battery 11 serving as a power source for the device 8 and the like, and an alternator 12 for charging the low voltage battery 11 are provided. The electric motor control device 7 and the electronic control device 8 function as electric motor driving force control means and engine output control means. Reference numeral 13 denotes a differential gear. Moreover, the charger 10 does not necessarily need to be mounted.

  The internal combustion engine 1 is, for example, a gasoline engine or a diesel engine, and can drive auxiliary machines such as an oil pump, an alternator 12 and a compressor of an air conditioner (air conditioner) and can generate a driving force according to traveling. The internal combustion engine 1 outputs a driving force to the drive shaft 4 via a transmission 6a constituting the second transmission system 6 and a clutch 6b which is a joint device disposed between the transmission 6a and the internal combustion engine 1. To do.

  The electric motor 2 can generate a driving force necessary for traveling, and is also driven by the internal combustion engine 1 or the driving wheel 3 to function as a generator by a regenerative operation. The electric motor 2 is selectively connected to the drive shaft 4 via the first transmission system 5.

  The first transmission system 5 includes a transmission gear device and a clutch. When the drive wheel 3 is driven by the internal combustion engine 1, the clutch is disconnected when the rotational speed of the drive shaft 4 exceeds the allowable limit rotational speed. Are controlled by In this case, the clutch may be either hydraulic or electromagnetic. As long as the first transmission system 5 can transmit the driving force of the electric motor 2 to the drive shaft 4, the configuration is not particularly limited to the above-described configuration, and the first transmission system 5 may be configured only with the rotary shaft. Good.

  The second transmission system 6 includes the transmission 6a and the clutch 6b described above, and transmits the driving force of the internal combustion engine 1 to the drive shaft 4 via the transmission 6a by connecting the clutch 6b. is there. The transmission 6a is an automatic transmission that changes the gear ratio according to the engine speed. The clutch 4 is capable of intermittently connecting between the input side rotating shaft 6c of the transmission 6a and the internal combustion engine 1. The drive shaft 4 is connected to the output side rotation shaft of the transmission 6a. As the clutch 6b, an existing forward clutch may be substituted. Such a forward clutch is connected when the transmission 6a is operated at least in the D range, and therefore does not require any special control for the intermittent operation.

  The electric motor control device 7 controls electric power supplied to the electric motor 2 so that the electric motor 2 outputs a driving force necessary for traveling. The electric motor control device 7 charges the battery 9 with electric power output from the electric motor 2 that is regeneratively operated when the vehicle is traveling at a reduced speed. Such a motor control device 7 includes an inverter or a DC-DC converter depending on the type of the motor 2.

  The electronic control unit 8 is an internal combustion engine based on signals output from various sensors attached to the internal combustion engine 1, an accelerator sensor that detects an operation amount of an accelerator pedal, and a brake sensor that detects an operating state of a brake pedal. The operating state of the engine 1 and the traveling state of the vehicle are detected, and the operating state of the internal combustion engine 1 is controlled according to the traveling state of the vehicle. The accelerator pedal is not mechanically connected to the throttle valve of the internal combustion engine 1, but is electrically connected to the throttle valve. In other words, the throttle valve opens and closes by controlling the electric actuator by a control amount set based on a signal output from the accelerator sensor.

  In addition to the control program for controlling the operating state of the internal combustion engine 1 so as to generate the driving force required for traveling, the electronic control unit 8 includes a clutch 6b of the second transmission system 6 when traveling by the driving force of the electric motor 2. A program for connecting and controlling the engine output of the internal combustion engine 1 is stored. This engine output control program will be described with reference to FIG. The engine output control program is executed when the vehicle is running with the driving force of the electric motor 2 and the clutch of the second transmission system 6 is connected.

  First, in step S1, the rotational speed of the input side rotating shaft 6c of the transmission 6a of the second transmission system 6 is detected. The rotational speed of the input-side rotary shaft 6c is directly measured by providing a rotational speed sensor on the input-side rotary shaft 6c, or is obtained by calculation based on the traveling speed of the vehicle at that time and the gear ratio of the transmission 6a. Any of them may be used.

  In step S2, the engine output of the internal combustion engine 1 is controlled so that the engine speed of the internal combustion engine 1 becomes the rotational speed of the input side rotary shaft 6c of the transmission 6a detected in step S1. That is, in this case, the amount of operation of the accelerator pedal changes in the running state, but the engine output of the internal combustion engine 1 controls the opening of the throttle valve, that is, the throttle opening regardless of the change in the amount of operation of the accelerator pedal. As a result, the engine speed of the internal combustion engine 1 is controlled to be the speed of the input side rotating shaft 6c of the transmission 6a.

  The control of the engine output in step S2 is performed so that the difference between the engine speed and the speed of the input side rotating shaft 6c of the transmission 6a falls within a predetermined range. This predetermined range excludes that the engine speed increases as the fuel consumption decreases, and that the engine speed decreases as the motor 2 assists the internal combustion engine 1 and affects the running speed. This is what you set.

  In such a configuration, when the vehicle is running with the driving force of the electric motor 2 and the clutch 6b of the second transmission system 6 is connected, the steps S1 and S2 are executed in this order, and the engine rotation of the internal combustion engine 1 is performed. The torque is such that the number substantially matches the rotational speed of the input side rotary shaft 6c of the transmission 6a, that is, the difference between the engine speed and the rotational speed of the input side rotary shaft 6c of the transmission 6a is within a predetermined range. Control engine output.

  In an operating state in which the engine speed is substantially the same as the rotational speed of the input-side rotary shaft 6c of the transmission 6a, the internal combustion engine 1 is operated at an engine speed that exceeds the idle speed according to the running state. is there. However, since the driving force of the internal combustion engine 1 does not contribute to traveling, it is in a substantially no-load operation state. Therefore, the amount of fuel consumed during the execution of this control does not increase so as to affect the overall fuel consumption during traveling. Further, since the engine speed of the internal combustion engine 1 is higher than the idle speed, even if a high load is generated by an auxiliary machine such as an air conditioner compressor, the auxiliary machines can be easily driven. In addition, the negative pressure for the brake booster can be efficiently secured.

  Further, when the hybrid vehicle starts to decelerate, the fuel of the internal combustion engine 1 is stopped, that is, the fuel is cut, but the internal combustion engine 1 continues to rotate by the driving force from the drive shaft 4 because the clutch 6b is connected. Therefore, the consumption of fuel is eliminated and the internal combustion engine 1 continues to rotate, so that the auxiliary machine can be driven and the negative pressure for the brake booster can be ensured as described above. Thus, by performing fuel cut at the time of deceleration, the total fuel consumption while operating the internal combustion engine 1 is reduced as compared with that in the prior art. Therefore, fuel consumption can be improved.

  In this way, by operating the engine 6 with the engine speed of the internal combustion engine 1 substantially equal to the speed of the input side rotary shaft 6c of the transmission 6a with the clutch 6b of the second transmission system 6 connected, the electric motor At the time of switching from running by 2 to running by the electric motor 2 and the internal combustion engine 1, it is possible to omit the necessity of synchronizing the rotational speeds of the internal combustion engine 1 and the transmission 2 when the clutch 6b is connected. Therefore, it is possible to smoothly switch between the internal combustion engine 1 and the electric motor 2 that are power sources.

  Furthermore, since the throttle opening is controlled based only on the rotational speed of the input side rotating shaft 6c of the transmission 6a, the development of the control program is facilitated. Specifically, for example, an existing transmission control program can be used for the control program of this embodiment.

  In the embodiment described above, in FIG. 1, the electric motor 2 is disposed on the side opposite to the internal combustion engine 1 with the differential gear 13 interposed therebetween. However, the electric motor 2 is arranged as shown in FIG. 1. It is not limited. The electric motor 2 may be arranged so as to be able to transmit the driving force to the driving wheel 3 alone and to be assisted by the driving force of the internal combustion engine 1. Specifically, for example, the electric motor 2 is disposed between the clutch 6b and the transmission 6a.

  In addition, the specific configuration of each part is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

The block diagram which shows the structure of embodiment of this invention. The flowchart which shows the procedure of control of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Electric motor 3 ... Drive wheel 4 ... Drive shaft 5 ... First transmission system 6 ... Second transmission system 6a ... Transmission 6b ... Clutch 6c ... Input side rotating shaft 7 ... Electric motor control device 8 ... Electronic control device

Claims (1)

An electric motor that can generate a driving force according to traveling and also functions as a generator;
An internal combustion engine capable of driving an auxiliary machine and generating a driving force according to traveling;
A drive shaft that transmits drive force to the drive wheels;
A first transmission system for transmitting the driving force of the electric motor to the drive shaft;
A second transmission system that includes a transmission and a joint device disposed between the transmission and the internal combustion engine, and transmits the driving force of the internal combustion engine to the drive shaft via the transmission when the joint device is connected;
An electric motor driving force control means for controlling the electric motor to output a driving force necessary for traveling when traveling by transmitting the driving force of the electric motor to the driving wheels via the first transmission system;
When traveling by transmitting the driving force of the electric motor to the driving wheels via the first transmission system, the rotational speed of the input side rotary shaft of the transmission is detected, and the rotational speed of the internal combustion engine is substantially equal to the detected rotational speed. The engine output of the internal combustion engine is controlled by controlling the throttle opening so that the driving force of the internal combustion engine contributes to the traveling by the rotation of the drive wheels, even though the coupling device of the second transmission system is connected. A hybrid vehicle comprising engine output control means for preventing the engine from being output.

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