JPH06165308A - Hybrid vehicle - Google Patents

Abstract

PURPOSE:To suppress exhaust of harmful components by deciding a schedule of an engine speed and a load based on a catalytic temperature, and controlling the operations of the engine and a generator based on the schedule. CONSTITUTION:A temperature sensor 23 detects the temperature of a catalyst and inputs a temperature signal to an engine controller 10. The controller 10 controls the operation of an engine 1 immediately after starting based on the input temperature signal. That is, the speed of the engine 1 is gradually increased from a low level until warm-up of the catalyst is finished. The charging quantity of a battery 4 is controlled through a charge quantity controller 11 to gradually increase the load of the engine 1 from a low level. Thus, after the engine 1 is started, the engine speed and load are suppressed to low values, and the engine 1 and the generator 2 are so controlled as to gradually increase them as time is elapsed. Thus, exhaust of harmful components can be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a motor that rotates with battery power as a power source for traveling, and improves the exhaust gas purification performance in a hybrid vehicle in which a battery is charged by a generator connected to an engine. Regarding means.

[0002]

2. Description of the Related Art A hybrid vehicle equipped with a motor rotated by battery power and a generator driven by an engine has a structure shown in FIG. 4, for example.

("An Experimental Study on Gas Turbin
e / Battery Hyblid Powered Vehicle "ASME 85-GT-203)
This is performed after the chopper 5 controlled by the chopper controller 12 waveform-controls the current supplied from the generator 2 having the engine 1 as a power source through the rectifier 3 and the current supplied from the battery 4. Supply to the motor 6,
It is driven by rotation of the motor 6.

A motor 6 rotates wheels 9 via a transmission 7 and a differential gear 8.

The operation of the engine 1 is controlled by the engine controller 30, and the operation of the generator 2 is controlled by the charge amount controller 31.

The engine 1 performs rated output operation when charging the battery 4 and driving the motor 6, and otherwise performs idle operation.

[0007]

Even in such a hybrid vehicle, it is necessary to provide a catalytic converter for purifying the exhaust gas of the engine 1 in the exhaust passage of the engine 1 from the viewpoint of environmental protection.

However, in this hybrid vehicle, the engine 1 is designed to perform only two types of operation, that is, rated output operation and idle operation, so that the catalyst is not activated sufficiently and immediately after the engine 1 is started. When an operation such as acceleration is performed, there is a problem that the exhaust gas purifying action of the catalyst does not sufficiently function and a large amount of harmful components such as HC, CO and NOx are temporarily discharged.

The present invention has been made to solve the above problems, and an object thereof is to control the operation of an engine in a hybrid vehicle according to the catalyst temperature.

[0010]

SUMMARY OF THE INVENTION The present invention provides a motor for running power, a battery for supplying electric power to the motor, a generator for charging the battery, an engine for driving the generator to rotate, and an engine exhaust. In a hybrid vehicle equipped with a catalytic converter for purification, means for detecting the temperature of the catalyst, means for determining the engine speed and engine load schedule based on the catalyst temperature detected by the detection means, and the schedule determined by the determination means And means for controlling the operation of the engine and the generator based on.

[0011]

[Function] The engine speed and load schedule are determined based on the catalyst temperature, and the operation of the engine and the generator are controlled based on this schedule. Therefore, when the catalyst temperature is low and the catalyst is not fully activated, Both engine speed and load are kept low to suppress the emission of harmful components.

[0012]

1 to 3 show an embodiment of the present invention. In addition,
The same components as those of the conventional example are designated by the same reference numerals and detailed description thereof will be omitted.

The hybrid vehicle shown in FIG. 1 is equipped with a motor 6 as a driving power source, and the rotation of the motor 6 is passed through a transmission 7 and a differential gear 8 to wheels 9.
Communicate to.

The current supplied from the battery 4 and the current supplied from the generator 2 via the rectifier 3 are supplied to the motor 6 after their waveforms are controlled by the chopper 5, and the motor 6 supplies these supplied currents. To rotate. Chopper 5
Are controlled by the chopper controller 12.

The generator 2 is directly connected to the engine 1 and generates power according to the rotation of the engine 1. The charge amount of the battery 4 is controlled by the charge amount controller 11. Also, engine 1
The operation of is controlled by the engine controller 10.

A catalytic converter 21 and a muffler 22 are provided in the exhaust passage 24 of the engine 1. A temperature sensor 23 that detects the temperature of the catalyst is attached to the catalytic converter 21. The temperature sensor 23 detects the temperature of the catalyst and inputs a temperature signal to the engine controller 10.

The engine controller 10 controls the operation of the engine 1 immediately after starting based on the input temperature signal. That is, until the catalyst warm-up ends, the engine 1
The number of revolutions of is gradually increased from a low level. In addition, the load of the engine 1 is gradually increased from a low level by controlling the charge amount of the battery 4 via the charge amount controller 11. For this purpose, the engine controller 10 obtains a map for obtaining the longest warm-up time for the catalyst temperature at startup, a map that defines the engine speed according to the elapsed time at startup for each catalyst temperature at startup, and a map for startup. And a map that defines engine load (battery charge) according to time for each catalyst temperature at startup.

Next, the operation will be described.

The operation of the engine 1 and the generator 2 in this hybrid vehicle is controlled according to the flow chart shown in FIG.

That is, immediately after the engine 1 is started, the temperature sensor 23 first detects the catalyst temperature To in step 1 and inputs a temperature signal to the engine controller 10.

Based on the input catalyst temperature T ₀ , the engine controller 10 reads the maximum time t _LIM required for warming up the catalyst from the map in step 2.

Further, based on this catalyst temperature T ₀ , the increase schedule of the engine speed N with respect to the elapsed time t from the start is read from the map in step 3, and the engine speed of the engine 1 is controlled according to this schedule (step 4). ).

Further, based on the catalyst temperature T ₀ , step 5
In the map, the increase schedule of the engine load W with respect to the elapsed time t from the start is read, and the charge amount of the battery 4 is controlled via the charge amount controller 11 according to this schedule to control the engine load W (step 6).

This control is continued until the catalyst temperature T _c detected by the temperature sensor 23 reaches the preset temperature T _set in step 7, or the maximum warm-up time t _LIM set in step 1 elapses. (Steps 7 and 8).

In this way, as shown in FIG. 3, after the engine 1 is started, both the engine speed and the load are kept low, and the engine 1 and the generator 2 are controlled so that they gradually increase over time. Therefore, it is possible to prevent the inconvenience that the number of revolutions and the load of the engine 1 rapidly increase and the emission of harmful components increases before the catalyst is sufficiently warmed up.

It should be noted that the temperature sensor is often provided conventionally for detecting abnormal overheat, and by using this as the temperature sensor 23, the cost of hardware can be reduced.

[0027]

As described above, in the hybrid vehicle of the present invention, the engine speed and the engine load schedule are determined based on the catalyst temperature, and the engine and the charger are controlled based on the determined schedule. It is possible to prevent the inconvenience that a large amount of harmful components are discharged due to sudden acceleration or the like before the catalyst is warmed up, and there is a preferable effect in preventing environmental pollution.

[Brief description of drawings]

FIG. 1 is a block diagram of a power unit for a hybrid vehicle showing an embodiment of the present invention.

FIG. 2 is a flowchart illustrating control contents of an engine and a generator.

FIG. 3 is a graph showing increasing characteristics of charge amount, catalyst temperature, exhaust temperature and engine speed immediately after startup.

FIG. 4 is a block diagram of a power unit for a hybrid vehicle showing a conventional example.

[Explanation of symbols]

 1 engine 2 generator 4 battery 6 motor 11 charge amount controller 20 engine controller 21 catalytic converter 22 temperature sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Innovator and tip Shinwa No. 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Mitsunori Ishii No. 2 Takara-cho, Kanagawa, Yokohama, Nissan Nissan Motor Co., Ltd. (72) Inventor Masaki Sugimoto 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Inventor ▲ Yoshi ▼ Shigeki Oka, 2 Takaracho, Kanagawa-ku, Yokohama, Japan Nissan Motor Co., Ltd.

Claims (1)

[Claims] 1. A motor for traveling power, a battery for supplying electric power to the motor, a generator for charging the battery, an engine for rotationally driving the generator, and a catalytic converter for purifying engine exhaust gas. In a hybrid vehicle, means for detecting the temperature of the catalyst, means for determining the engine speed and engine load schedule based on the catalyst temperature detected by the detecting means, and operation of the engine and generator based on the schedule determined by the determining means And a means for controlling the vehicle.