JP2001073806A - Control device and method for hybrid automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an output of an internal combustion engine without deteriorating efficiency of the internal combustion engine. SOLUTION: An operation rate of an accelerator pedal is sensed by a CPU based on a signal sensed by means of an accelerator pedal sensor (S1). Self car speed is sensed based on a vehicular speed signal from a car speed sensor (S2). An output required by an engine is calculated from the accelerator pedal operation rate and the self car speed (S3). It is determined whether the calculated requirement output value is less than a set value or not (S4). When the answer is YES, a changeover valve is changed over according to a changeover control signal from the CPU (S5). Air heated by a radiation means of an inverter is intaken into an intake system through a heating passage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid in which an internal combustion engine and a motor are mounted as power sources, a DC output of a battery is converted to AC by an inverter to supply power to the motor, and the hybrid vehicle runs using both the internal combustion engine and the motor. The present invention relates to an automobile control device and a control method thereof.

[0002]

2. Description of the Related Art In recent years, as awareness of global environmental protection has been increasing on a worldwide scale, as a specific measure for reducing the amount of carbon dioxide in exhaust gas of automobiles, low pollution by combining a gasoline engine and a motor has been proposed. A hybrid vehicle, which is a practical vehicle, has been proposed, and specifically, for example, those described in Japanese Patent Application Laid-Open Nos. Hei 9-111010 and Hei 10-238381 have been proposed.

[0003] Generally, this type of hybrid vehicle transmits rotation generated by driving a gasoline engine, which is an internal combustion engine, to a generator and drives it, and the electric power obtained by this generator is stored in a battery. There is a series (series) type in which the power is supplied and charged and the drive motor is driven by the power of the battery, and a parallel (parallel) type in which the vehicle is driven by both the gasoline engine and the motor. .

In the case of this parallel type hybrid vehicle, a motor and a gasoline engine are switched to be used as a power source. At this time, switching between the motor and the gasoline engine is conventionally performed by, for example, a vehicle speed sensor or an accelerator pedal by a driver. Is performed based on the amount of depression of the brake pedal, on / off of the brake pedal, and the like.

In order to increase the thermal efficiency of a gasoline engine, a CVT (Continuously Variable Transmissible
On / continuously variable transmission) is controlled to drive along the best fuel consumption curve shown in the engine best fuel consumption curve diagram of FIG. Each asymptote in FIG. 5 is an equal output curve represented by (engine speed × engine torque).

[0006]

However, when running on a gasoline engine, the engine output must be reduced when the output required for running is low, for example, to run at a constant speed. When the engine output is reduced by reducing the throttle, there is a problem that the efficiency of the engine is reduced.

[0007] In addition, even if the hybrid vehicle is used in combination with a gasoline engine and a motor is used to drive the vehicle in a low engine output range such as running at a constant speed, the motor runs when the battery capacity is low. Even at a constant speed, the vehicle must rely only on the engine output.

An object of the present invention is to reduce the output of an internal combustion engine without lowering the efficiency of the internal combustion engine.

[0009]

In order to solve the above-mentioned problems, a control apparatus for a hybrid vehicle according to the present invention includes an internal combustion engine and a motor as power sources, and converts a DC output of a battery into an AC by an inverter. In the control device of the hybrid vehicle that powers the motor and travels using the internal combustion engine and the motor together, the air branched from the normal path on the upstream side of the intake system and heated by the heating unit is heated. A heating path to be supplied, a switching valve provided downstream of a junction of the normal path and the heating path, and a request output value required for the internal combustion engine is lower than a preset value. A control unit that controls the switching valve to switch the upstream of the intake system from the normal path to the heating path side.

With this structure, when the required output value required for the internal combustion engine is lower than the set value, the upstream of the intake system is switched from the normal path to the heating path by the switching valve. Is warmed, the density of the intake air to the internal combustion engine decreases, and the mass of the intake air having the same volume is lower than usual. Therefore, there is no need to throttle the throttle valve, and the pumping loss can be reduced and the efficiency of the internal combustion engine can be increased as compared with a case where the same output of the internal combustion engine is obtained by narrowing the throttle valve as in the related art.

Further, the control device for a hybrid vehicle according to the present invention is characterized in that the heating means comprises a heat radiating means of the inverter, and supplies the air heated by the heat radiating means from the heating path.

[0012] In this case, by supplying the air heated by the heat radiating means of the inverter to the internal combustion engine, the heat generated by the inverter, which has been discharged to the outside, can be effectively used.

Further, in the control apparatus for a hybrid vehicle according to the present invention, the control unit may control the required output value based on an accelerator pedal depression amount detected by an accelerator pedal sensor and a vehicle speed detected by a vehicle speed sensor. Is calculated.

Thus, the required output value required for the internal combustion engine can be calculated.

In the method for controlling a hybrid vehicle according to the present invention, a heating path for supplying the air heated by the heating means is branched from a normal path on the upstream side of the intake system to form a branch in the internal combustion engine. When the required output value is lower than a preset value, the normal path and the heating path are switched by a switching valve provided downstream of a junction of the normal path and the heating path. It is characterized by:

With this configuration, when the required output value required for the internal combustion engine is lower than the set value, the upstream of the intake system is switched from the normal path to the heating path, so that the intake air to the internal combustion engine is warmed. This eliminates the need to throttle the throttle valve, and makes it possible to reduce the pumping loss and increase the efficiency of the internal combustion engine as compared with the case where the same internal combustion engine output is obtained by narrowing the throttle valve as in the conventional case. .

Further, in the method of controlling a hybrid vehicle according to the present invention, the heating path supplies the air heated by the heat radiating means of the inverter. In this case, by effectively utilizing the heat generated by the inverter, the output of the internal combustion engine can be reduced without lowering the efficiency of the internal combustion engine.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. 1 to 4, wherein FIG. 1 is a schematic configuration diagram of a gasoline engine, FIG.
FIG. 3 is an operation explanatory diagram, and FIG. 4 is a flowchart for operation explanation.

First, the configuration of a gasoline engine as an internal combustion engine according to this embodiment will be described. As shown in FIG. 1, a throttle valve 2 that opens and closes in response to an accelerator pedal (not shown) is provided in an intake system 1. A surge tank 3 is provided on the downstream side, and a fuel injection valve 5 is provided near one end of an intake manifold 4 of the intake system 1 communicating with the surge tank 3. 6, the injection time of the fuel injection valve 5 is controlled.

On the other hand, in the exhaust system 20, an O ₂ sensor 21 for detecting the amount of oxygen in the exhaust gas is provided upstream of a three-way catalyst 22 disposed in an exhaust pipe leading to a muffler (not shown). The O ₂ sensor 21 outputs a voltage signal corresponding to the amount of oxygen to the electronic control unit 6.

The electronic control unit 6 includes a central processing unit (hereinafter, referred to as CPU) 7, a RAM 8 for temporarily storing data, an input interface (hereinafter, interface is referred to as I / F) 9, Output I / F10
And a ROM 11 storing a predetermined control program and the like.

At this time, the input I / F 9 includes a vehicle speed signal from a vehicle speed sensor 14 for detecting the vehicle speed, a throttle opening signal from a throttle sensor 15 for detecting the opening of the throttle valve 2, and a cooling water temperature of the engine. In addition to the water temperature signal from the water temperature sensor 16 and the voltage signal from the O ₂ sensor 21 described above, a detection signal proportional to the amount of depression of the accelerator pedal is input from an accelerator pedal sensor 17 for detecting the amount of depression of the accelerator pedal (not shown). You. The output I / F 10 outputs a fuel injection signal to the fuel injection valve 5 and outputs an ignition pulse to the spark plug 18.

Further, as shown in FIGS. 1 and 2, on the upstream side of the intake system 1, a motor drive as a power source (not shown) is connected to a normal path 32 for sucking outside air through an air cleaner 31. The heat radiating means 33 of the inverter is used as a heating means, and a heating path 34 for supplying the air heated by the heat radiating means 33 of the inverter is formed to be branched, and is switched to a downstream side from a junction of the normal path 32 and the heating path 34 Valve 3
5 is provided, and the CPU 7 that functions as a control unit
A required output value required for the gasoline engine is calculated, and when the required output value is lower than a preset value, the upstream of the intake system 1 is moved from the normal path 32 to the heating path 34.
The switching control signal is output from the CPU 7 to the switching valve 34 via the output I / F 10 to switch to the switching valve 35.
Is switched.

At this time, the radiating means 33 of the inverter is a radiating plate, a radiating fan, or the like attached to the elements constituting the inverter to release heat generated by the elements. The heating path 34 heats and inhales the air by the applied heat.

The required output value of the gasoline engine by the CPU 7 is calculated based on the detection signal from the accelerator pedal sensor 17 and the vehicle speed signal from the vehicle speed sensor 14 input to the CPU 7. That is, as shown in FIG.
The amount of depression of the accelerator pedal is, for example, 100%, 95%
%, 90%,..., The relationship between the vehicle speed (km / h) and the driving force (N) is derived in advance, and the relationship is stored in the ROM 11 in advance as a map. Then, the driving force (N) of the vehicle required at that time is read from the above-mentioned map from the accelerator pedal depression amount based on the detection signal and the own vehicle speed based on the vehicle speed signal, and the read driving force (N) and engine speed are read. (Rpm), the required output value (kW) required of the engine is calculated.

The required output value thus calculated is
When the value is lower than the predetermined set value, the switching valve 35 is switched as described above, and the air heated from the heating path 34 is sucked into the intake system 1. If the required output value is higher than a predetermined set value, the switching valve 35 is not switched, and normal-temperature air is drawn into the intake system 1 from the normal path 32.

Next, the operation will be described with reference to the flowchart of FIG.

As shown in FIG. 4, the depression amount of the accelerator pedal is detected by the CPU 7 based on the detection signal from the accelerator pedal sensor 17 (S1), and the own vehicle speed is detected based on the vehicle speed signal from the vehicle speed sensor 14. (S
2) From the detected depression amount of the accelerator pedal and the own vehicle speed, the required output value required for the engine is calculated as described above (S3), and whether the calculated required output value is lower than the set value or not. Is determined (S
4).

Then, the decision result in the step S4 is YES.
, The switching valve 3 is switched by the switching control signal from the CPU 7.
5 is switched (S5), and the heat radiating means 33 of the inverter is switched.
The air warmed by the air passes through the heating path 34 and passes through the intake system 1.
Inhaled. On the other hand, if the decision result in the step S4 is NO, the switching control signal is not output from the CPU 7, the switching of the switching valve 35 is not performed (S6), and the normal-temperature air is passed through the normal path 32 to the intake system. Inhaled into 1.
Thereafter, after the processes of steps S5 and S6, the process returns to the start.

Therefore, according to the above-described embodiment, when the required output value required for the gasoline engine is lower than the set value, the switching valve 35 moves the upstream of the intake system 1 from the normal path 32 to the heating path 34 side. By being switched,
Heated air can be supplied to the engine, and the density of the intake air to the engine decreases, so that the mass of the intake air of the same volume becomes lower than usual. As compared with a case where the same engine output is obtained by reducing the throttle valve 2, the pumping loss can be reduced, and the output of the engine can be reduced while maintaining the engine thermal efficiency in a high efficiency state.

As a result, in a parallel-type hybrid vehicle, when the vehicle is running with a low engine output, such as when traveling at a constant speed, the vehicle should be driven only by the engine because the remaining battery power is small. Even when it is necessary to operate the engine, the engine can be operated in a highly efficient state.

Further, since the heat radiating means 33 of the inverter is used as the heating means, the heat generated by the inverter can be effectively used, and the engine output can be reduced without lowering the engine efficiency.

In the above embodiment, the case where the heating means is the heat radiating means 33 of the inverter has been described. However, the heating means is not particularly limited to this, and other heating elements may be used. .

In the above-described embodiment, the internal combustion engine is described as a gasoline engine. However, the internal combustion engine is not limited to this, and may be another internal combustion engine.

The present invention is not limited to the above embodiment, and various changes other than those described above can be made without departing from the gist of the present invention.

[0036]

As described above, according to the first and fourth aspects of the present invention, when the required output value required for the internal combustion engine is lower than the set value, the upstream of the intake system is heated from the normal path. By switching to the path side, the intake air to the internal combustion engine can be warmed, and there is no need to throttle the throttle valve.In comparison with the case where the same internal combustion engine output is obtained by narrowing the throttle valve as in the past, pumping loss is reduced. Thus, the efficiency of the internal combustion engine can be increased.

Therefore, when the hybrid vehicle runs at a low output of the internal combustion engine, such as running at low speed,
Even when running with only the internal combustion engine is required with a low remaining battery, the thermal efficiency of the internal combustion engine can be maintained in a high efficiency state, and the fuel consumption can be further reduced.

According to the second and fifth aspects of the present invention, the air heated by the heat radiating means of the inverter is supplied to the internal combustion engine, so that the heat generated by the inverter which has radiated heat to the outside is effectively used. be able to.

According to the third aspect of the present invention, it is possible to calculate a required output value required for the internal combustion engine.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a gasoline engine according to an embodiment of the present invention.

FIG. 2 is a partial detailed configuration diagram according to an embodiment of the present invention.

FIG. 3 is an operation explanatory diagram according to the embodiment of the present invention.

FIG. 4 is a flowchart illustrating an operation according to the embodiment of the present invention.

FIG. 5 is an operation explanatory diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intake system 7 CPU (control part) 14 Vehicle speed sensor 17 Accelerator pedal sensor 32 Normal path 33 Inverter heat radiating means (heating means) 34 Heating path 35 Switching valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Minoru Yoshida, 2-1-1, Taoyuan, Ikeda-shi, Osaka Inside Daihatsu Industry Co., Ltd. (72) Tsutomu Michioka 2-1-1, Taoyuan, Ikeda-shi, Osaka Inside Daihatsu Kogyo Co., Ltd. (72) Kazuyuki Yamaguchi 2-1-1 Taoyuan, Ikeda-shi, Osaka Prefecture Inside Daihatsu Kogyo Co., Ltd. Takashi Kurimoto 2-1-1 Taoyuan, Ikeda-shi, Osaka Daiha F Kogyo Co., Ltd. F-term (reference) TB01 TE03 TE04 TE08 TO21

Claims (5)

[Claims] 1. A hybrid vehicle equipped with an internal combustion engine and a motor as power sources, converting a DC output of a battery into AC by an inverter, supplying power to the motor, and controlling a hybrid vehicle that runs using both the internal combustion engine and the motor. In the apparatus, a heating path that is formed by branching off from a normal path on the upstream side of the intake system and supplies the air heated by the heating means, and is provided downstream from a junction of the normal path and the heating path. And controlling the switching valve to switch the upstream of the intake system from the normal path to the heating path side when a required output value required for the internal combustion engine is lower than a preset value. A control device for a hybrid vehicle, comprising: a control unit. 2. The hybrid vehicle control device according to claim 1, wherein said heating means comprises a heat radiating means of said inverter, and supplies the air heated by said heat radiating means from said heating path. 3. The control unit calculates the required output value based on an accelerator pedal depression amount detected by an accelerator pedal sensor and a vehicle speed detected by a vehicle speed sensor. 3. The control device for a hybrid vehicle according to 1 or 2. 4. Control of a hybrid vehicle equipped with an internal combustion engine and a motor as power sources, converting DC output of a battery into AC by an inverter, supplying power to the motor, and running using the internal combustion engine and the motor together. In the method, a heating path for supplying air heated by heating means is branched and formed with respect to a normal path on the upstream side of the intake system, and a required output value required for the internal combustion engine is set to a predetermined setting. A control method for a hybrid vehicle, wherein when the value is lower than the value, the normal path and the heating path are switched by a switching valve provided downstream of a junction of the normal path and the heating path. 5. The control method for a hybrid vehicle according to claim 4, wherein said heating path supplies air heated by heat radiating means of said inverter.