JP5171177B2 - 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 an auxiliary machine is driven by an internal combustion engine, there is a possibility that the driving state cannot be maintained by idling operation. 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.

  In the above-described configuration, depending on the shift speed of the transmission while the internal combustion engine is idling with the clutch disconnected, a shift operation may be required when the clutch is connected. That is, when running with an electric motor and the internal combustion engine is idling, the transmission is at an intermediate shift position between the low speed stage and the high speed stage so that it can quickly respond to the running state at that time. . For this reason, it is necessary to shift the transmission according to the traveling state, and there is a possibility that the control of the transmission when the clutch is connected becomes complicated.

  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 driving shaft that transmits driving force to the driving wheel, a first transmission system that transmits driving force of the electric motor to the driving shaft, an automatic transmission, and a joint device disposed between the automatic transmission and the internal combustion engine, A second transmission system configured separately from the first transmission system that transmits the driving force of the internal combustion engine to the drive shaft via the automatic transmission when the coupling device is connected; and the first transmission Motor driving force control means for controlling the motor to output the driving force required for traveling when the driving force of the motor is transmitted to the drive wheels via the system, and the joint device is disconnected when traveling by the motor It was always an automatic transmission car even in a state And a transmission control means for controlling the shift speed corresponding to the running state based on the operation amount of the accelerator pedal, a state where the cut coupling device during driving by the electric motor always operating an internal combustion engine is also idle speed And an engine output control means for controlling the engine output of the internal combustion engine so as to be substantially equal to the rotational speed of the input side rotary shaft of the automatic transmission exceeding the above.

  According to such a configuration, when traveling by transmitting the driving force of the electric motor to the driving wheel, the coupling device of the second transmission system is cut, so that the internal combustion engine is prevented from being dragged due to road surface conditions or the like. Can do. In addition to this, since the engine output control means controls the engine output so that the engine speed of the internal combustion engine becomes the speed of the input side rotating shaft of the transmission, the number of revolutions on the input side and the output side of the joint device Almost match. During this time, since the automatic transmission is controlled by the transmission control means to the gear stage according to the running state, the automatic transmission is maintained in the operating state almost the same as when the driving is performed by the driving force of the internal combustion engine. Be drunk.

  In such a state, when switching from running by the electric motor to running 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 automatic transmission Even if it exists, since it is operating according to the running at that time, it becomes possible to quickly add the driving force of the internal combustion engine.

  Furthermore, while the vehicle is running, the rotation speed of the input-side rotary shaft of the transmission is higher than the idle rotation speed of the internal combustion engine, so that the operation of the internal combustion engine is prevented from stopping even if 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 wheels, the coupling device of the second transmission system is cut off. In the automatic transmission, the transmission control means is changed according to the running state, so that when the coupling device is connected, the gear position is adjusted according to the operating state of the automatic transmission. Control can be lost.

  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 At least an alternator 12 for charging the low voltage battery 11 serving as a power source for the device 8 and the like and a 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, transmission 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, and may be configured to use a stationary charger in a home or a gas station.

  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 supplies a driving force to a drive shaft 4 via an automatic transmission 6a constituting the second transmission system 6 and a clutch 6b which is a joint device disposed between the automatic transmission 6a and the internal combustion engine 1. Is output.

  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 automatic 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 automatic transmission 6a by connecting the clutch 6b. Is. In the automatic transmission 6a, the gear ratio is changed based on the traveling speed of the vehicle, that is, the vehicle speed, and the operation amount of an accelerator pedal, that is, a throttle opening that will be described later. The clutch 4 can connect and disconnect between the input side rotating shaft 6c of the automatic transmission 6a and the internal combustion engine 1. The drive shaft 4 is connected to the output side rotation shaft of the automatic transmission 6a. As the clutch 6b, an existing forward clutch may be substituted. Since the forward clutch is connected when the automatic transmission 6a is operated at least in the D range, no special control is required 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 is a so-called electronic throttle that opens and closes when the electric actuator is controlled by a control amount set based on a signal output from the accelerator sensor. Needless to say, the output of the electric motor 2 is controlled based on the output signal 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 cutting 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. In this engine output control program, when the vehicle is driven by the driving force of the electric motor 2 and the clutch 6b of the second transmission system 6 is disconnected, that is, the driving force of the internal combustion engine 1 is transmitted to the drive wheels 4. It is executed in an operation state that is not performed.

  First, in step S1, the gear position of the automatic transmission 6a is controlled based on the vehicle speed at this time and the operation amount of the accelerator pedal. In other words, since the driving state of the vehicle is set by the driver operating the accelerator pedal, the speed required to obtain the driving state requested (desired) by the driver is determined by operating the vehicle speed and the accelerator pedal. The map set according to the amount is searched, and the automatic transmission 6a is operated so as to be the gear position.

  In step S2, the rotational speed of the input side rotating shaft 6c of the automatic transmission 6a of the second transmission system 6 is detected. The rotational speed of the input side rotational shaft 6c is directly measured by providing a rotational speed sensor on the input side rotational shaft 6c, or is calculated and calculated based on the traveling speed of the vehicle at that time and the gear ratio of the automatic transmission 6a. Any of them may be used.

  In step S3, 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 automatic transmission 6a detected in step S2. 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 automatic transmission 6a.

  The control of the engine output in step S3 is performed so that the difference between the engine speed and the speed of the input side rotating shaft 6c of the automatic 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 disengaged, the steps S1 to S3 are executed in this order to make the automatic transmission 6a The speed is controlled according to the driving state at the time, and the engine speed of the internal combustion engine 1 substantially matches the speed of the input side rotary shaft 6c of the automatic transmission 6a, that is, the engine speed and the automatic transmission 6a. The engine output is controlled to a torque such that the difference from the rotational speed of the input side rotary shaft 6c falls within a predetermined range.

  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 automatic transmission 6a, the internal combustion engine 1 is operated at an engine speed that exceeds the idle speed according to the running state. Is. However, the internal combustion engine 1 is substantially in a no-load operation state because the driving force does not contribute to traveling because the clutch 6b of the second transmission system 6 is disengaged. 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, the engine speed of the internal combustion engine 1 is higher than the idle speed because it is substantially the same as the rotational speed of the input-side rotary shaft 6c of the traveling automatic transmission 6a, so that the alternator 12 and the compressor of the air conditioner Even if such a high load is generated by the auxiliary machines, these auxiliary machines can be driven easily. Therefore, the charging efficiency of the low voltage battery 12 can be increased. In addition, the negative pressure for the brake booster can be efficiently secured.

  Further, since the internal combustion engine 1 is separated from the drive wheels 4 by the clutch 6b, the internal combustion engine 1 is not affected by the road surface condition during traveling. Therefore, dragging of the internal combustion engine 1 due to road surface conditions or the like can be prevented, and the internal combustion engine 1 can be operated efficiently.

  In this way, with the clutch 6b of the second transmission system 6 disengaged, the automatic transmission 6a is controlled to a gear position according to the running state at that time, and the engine speed of the internal combustion engine 1 is controlled by the automatic transmission 6a. By operating in a state substantially equal to the rotational speed of the input side rotating shaft 6c, at the time when the clutch 6b is connected, that is, traveling from the electric motor 2 to traveling by the electric motor 2 and the internal combustion engine 1, or only by the internal combustion engine 1 When switching to traveling, it is possible to omit the need to synchronize the engine speed of the internal combustion engine 1 and the rotation speed of the input side rotary shaft 6c of the transmission 2, and at this time the speed of the automatic transmission 6a is changed. It is not necessary to perform control to change according to the running state. Therefore, switching of the power source between the internal combustion engine 1 and the electric motor 2 can be performed quickly and smoothly as desired.

  Furthermore, since the throttle opening is controlled based only on the rotational speed of the input side rotating shaft 6c of the automatic 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. What is necessary is just to arrange | position the electric motor 2 so that a driving force can be transmitted to the driving wheel 3 independently.

  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 ... 1st transmission system 6 ... 2nd transmission system 6a ... Automatic transmission 6b ... Clutch 6c ... Input side rotating shaft 7 ... Electric motor control apparatus 8 ... Electronic control apparatus

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 first transmission system that includes an automatic transmission and a joint device disposed between the automatic transmission and the internal combustion engine, and transmits the driving force of the internal combustion engine to the drive shaft via the automatic transmission when the joint device is connected. A second transmission system configured separately from the drive shaft,
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;
A transmission control means for controlling the automatic transmission to a gear position according to the traveling state based on the vehicle speed and the amount of operation of the accelerator pedal at all times even when the coupling device is disconnected during traveling by the electric motor;
Even when the coupling device is disconnected during traveling by the electric motor, the internal combustion engine is always operated, and the engine output of the internal combustion engine is controlled so as to be approximately equal to the rotational speed of the input side rotational shaft of the automatic transmission that exceeds the idle rotational speed A hybrid vehicle comprising engine output control means.

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