JPH0674026A - Exhaust emission control device for automobile - Google Patents

Abstract

PURPOSE:To suppress waste of power to minimum and improve purification performance by providing a circuit and program which operate a circuit for preheating only a heater of an oscillating tube of microwave to heat a catalyst. CONSTITUTION:A battery 2 and a magnetron 7 for radiating microwave are provided. A heater trans 11 heats a heater of the magnetron 7. A door switch 12 is set ON when a door of a vehicle is opened, while a seat switch 13 is set ON when a driver seats. A key switch is set ON when a key is inserted so as to start an engine, while a start switch 15 is set ON when the key is turned at the time of starting the engine. The above-mentioned switches are operated for a period previously set in a series, and the start switch 15 is set ON. Then, a microwave control device 9 is operated for a predetermined period for irradiating microwave. Waste of power is suppressed to minimum, and purification performance is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle exhaust gas purifying apparatus.

[0002]

2. Description of the Related Art As shown in FIG. 1, an automobile exhaust gas purifying apparatus comprises a main exhaust gas purifying apparatus and a sub exhaust gas purifying apparatus.
Most of the methods are adopted in the place. However,
The volume of the main and subordinate automobile exhaust gas purifiers is about 1000 cc each (depending on the exhaust gas capacity of the automobile), so this catalyst can be used for a short time (about 10 to 10%) when the engine is cold-started (cold start). The temperature could not be raised to a temperature at which the catalyst works (about 250 ° C. to 300 ° C.) within 20 seconds, and harmful exhaust gas generated within 1 minute was released to the atmosphere. In order to prevent this, it is necessary to rapidly heat the catalyst, and it is considered to use microwaves as a heating means. In this case, even if the circuit that radiates microwaves is activated at the same time when the engine is started, by the time the heater (cathode) of the magnetron heats up,
Since it takes 3 to 5 seconds, it was difficult to raise the temperature of the purifying means (catalyst) to 250 to 300 ° C. within 10 to 20 seconds after starting the engine. As a measure against this, a means for heating immediately before engine start (several tens of seconds to 1 minute), that is, a program configuration for starting heating when the door is opened, when a seat is seated, or when a key is inserted There was a problem that the heating means worked and the battery power was consumed even when the engine was not started, such as when inserting the key when listening to the radio when you left something in the car or when waiting for a person in the car. . The present invention aims to minimize this wasted power and improve the purification performance.

[0003]

However, in the above-mentioned conventional structure, since the heating is performed when the door is opened or when the seat is seated, even when the engine is not started, such as when something is left behind in the vehicle. When the door is opened, the heating means operates and the battery power is consumed.

The present invention is intended to minimize this wasteful power and improve the purification capacity.

[0005]

In order to achieve the above object, the present invention provides an exhaust gas purifying apparatus equipped with a catalyst in an exhaust portion of an engine of an automobile, and a means for heating the catalyst when the engine is started. , When the door key of the car is inserted or when the door is opened, when sitting on the driving seat, when the engine start key is inserted, the heater of the microwave oscillation magnetron that heats the catalyst is preheated. Only the circuit is operated, and high pressure is applied only when the engine is started to heat the catalyst. With this configuration, when only the door is opened, only the preheating circuit of the heater of the microwave oscillation tube is operated, and the current in this case is about 3 to 4 A (ampere) and can be processed by the capacity of the conventional battery. . Further, in the conventional example, the current flows about 100 A (ampere), which is about 33 times that of the present invention. About 10 without starting the engine
The waste of 0 A (ampere) was a fatal drawback for the battery, and it was necessary to increase the capacity of the battery or install another battery.

[0006]

With the above structure, the present invention can quickly raise the temperature of the catalyst to a temperature (about 250 ° C. to 300 ° C.) at which exhaust gas can be purified immediately after the engine of the automobile is started. Hydrocarbons (HC)
Can be reduced reasonably.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, 1 is an engine, 2 is a battery for starting the engine and also serves as a microwave power source, 3 is a manifold for connecting engine exhaust to an exhaust pipe, and 4 is a main exhaust gas purifying catalyst unit (three-way catalyst). It works to purify various harmful exhaust gases. A sub-exhaust gas purification catalyst unit 5 serves to completely purify harmful exhaust gas that could not be purified by the main exhaust gas purification catalyst unit. Reference numeral 6 is a cold start exhaust gas purifying catalyst unit of the present invention, which is made of a material such as ceramics that transmits microwaves, and is coated or impregnated with a radio wave absorber and attached with a catalyst material. Reference numeral 7 is a magnetron for generating microwaves, 8 is a waveguide for supplying the microwaves generated by the magnetron 7 to the cold start exhaust gas purification catalyst unit 6, and 9 is a microwave for controlling the generation of microwaves. Wave controller,
10 is a state in which the engine 1 is once started and the temperature of each of the attached catalysts 4, 5 or 6 rises, and then the engine 1 is turned off, and the respective catalysts 4, 5 or 6 remain warm (the catalyst is activated). It is a temperature switch for stopping the generation of microwaves when restarting during the (state).

FIG. 2 is a detailed embodiment of the microwave controller 9 of FIG. 1, in which 2 is a battery, 7 is a magnetron for irradiating microwaves, 11 is a heater transformer for heating a heater of the magnetron, A door switch 12 that is turned on when the vehicle door is opened, and a seat switch 1 that is turned on when the vehicle door is opened and the driver is seated
3. A key switch 14 that is turned on when a key is inserted to start the engine, and a start switch 15 that is turned on when the key is turned to start the engine. The above switches operate for a preset time in the series, and when the start switch 15 is turned on, the microwave control device 9 operates for a preset time and radiates microwaves. Each preset time is a program in which the remaining time of the previous process is cut off when the switch of the next process is turned on.

FIGS. 3a, 3b and 3c are time charts showing the program operation of FIG. 2 for easy understanding. a is a normal engine starting state, b is a state in which the door is opened in a state where there is no possibility of starting the engine such as when something left inside the vehicle, and c is a state in which the vehicle is used for a preset time. is there.

A is about 5 seconds from inserting the door key to open the door and sitting on the seat, about 10 seconds from sitting on the seat and putting on the safety belt to insert the key, about 1 second from inserting the key to starting the engine, After starting the engine, the microwave oscillating time is about 20 seconds and the exhaust gas purifying device is stopped. (The power consumption at this time is about 0.068 Kwh, which is about 1 of the conventional example.
/1.8) In the case of the present invention, 12V x 3.5A x 16 seconds ÷ 3600 seconds + 12V x 100A x
20 seconds / 3600 seconds = 0.068Kwh In the case of the conventional example 12V × 100A × 36 seconds / 3600 seconds = 0.1
2Kwh (1.76 times) b is the state when the door is opened for about 2 minutes, such as when you forget something in the car. (Power consumption at this time is about 0.00
7Kwh About 1/29 of the conventional example) In the case of the present invention 12V × 3.5A × 60 seconds / 3600 seconds = 0.0
07Kwh In case of conventional example 12V × 100A × 60 seconds / 3600 seconds = 0.2
Kwh (28.5 times) c is about 1 time until the seat is seated after the door key is inserted and the door key is inserted according to the embodiment of the present invention which has been used for a preset time.
It takes about 1 minute to sit on the seat and put on the safety belt to insert the key, and about 1 minute to insert the key and start the engine. After the engine starts, the microwave emission time is about 20 seconds and the exhaust gas purification device stops. To do. (The power consumption at this time is about 0.088 Kwh, which is about 1 / 7.6 of the conventional example.) In the case of the present invention, 12V × 3.5A × 180 seconds / 3600 seconds + 12V × 100A
× 20 seconds ÷ 3600 seconds = 0.088Kwh In the case of the conventional example 12V × 100A × 200 seconds ÷ 3600 seconds = 0.
67Kwh (7.6 times) FIGS. 4a and 4b are timing charts showing the relationship between the temperature rise of the cold start exhaust gas purification catalyst unit 6 and the generation amount of hydrocarbons (HC) and purification based on experimental data. 4a is a purification curve when the magnetron heater of the present invention is preheated, and FIG. 4b is a purification curve when the magnetron heater is not preheated. The change in the exhaust gas purification rate due to the difference in the preheat time lag of the magnetron heater is clearly understood. A curve A is an example of a curve of the amount of hydrocarbon (HC) exhaust in the state without the exhaust gas purifying device of the present invention, and actually varies greatly depending on the engine speed (how the accelerator is depressed). Curve B
Is the average temperature rise value of the cold start exhaust gas purification catalyst, and at the same time represents the purification capacity of the catalyst. According to the apparatus of the present invention, when the magnetron heater of the cold start exhaust gas purifying apparatus is preheated (Fig. 4a), the temperature of the catalyst is about 250 ° C in about 15 seconds. A curve C is a product of the hydrocarbon (HC) concentration and the purification rate and represents the purification state.

FIG. 4a shows about 55% purification about 15 seconds after the engine is started and about 75% purification about 20 seconds after the engine is started.

FIG. 4b shows almost no purification for about 15 seconds after engine start. About 20 seconds after starting the engine,
It is a purification of about 55%.

[0014]

As described above, the following effects can be obtained in the cold start exhaust gas purifying apparatus for an automobile according to the present invention.

By effectively using the electric power of the battery, it is possible to purify a large amount of hydrocarbons (HC) generated in a short time of about 1 minute from the start of the engine without mounting a dedicated battery for purification.

[Brief description of drawings]

FIG. 1 is a principle diagram of an exhaust gas purifying apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a microwave control device of the exhaust gas purification device.

FIG. 3 is a control timing chart of an engine starting state of the exhaust gas purification device.

FIG. 4A is a characteristic diagram of the exhaust gas purifying apparatus of the present invention when the magnetron heater is preheated, and FIG. 4B is a characteristic diagram of the same exhaust gas purifying apparatus when the magnetron heater is not preheated.

[Explanation of symbols]

 6 Cold start Exhaust gas purification catalyst unit 9 Microwave control device 12 Door switch 13 Seat switch 14 Key insertion switch 15 Start switch

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location F02D 45/00 395 Z 7536-3G F02N 11/08 Y 8614-3G

Claims (5)

[Claims] 1. A vehicle equipped with a catalyst in an exhaust portion of an engine of a vehicle, and a vehicle having a cold start exhaust gas purifying apparatus that uses a microwave as a means for heating the catalyst when the engine is started, has a door key inserted or a door of the vehicle installed. A circuit and program for operating a circuit for preheating only the heater of the microwave oscillation tube that heats the catalyst when opened, sitting in the driver's seat, or inserted with the engine key Equipped vehicle exhaust gas purification device. 2. A circuit for operating only a preheating circuit of a heater of a microwave oscillation tube for a preset time when a door key of the vehicle is inserted or a door is opened in a vehicle with a cold start exhaust gas purifying device using microwaves. The exhaust gas purifying apparatus for an automobile according to claim 1, further comprising: 3. A vehicle equipped with a cold start exhaust gas purifying apparatus using microwaves, comprising a circuit and a program for activating only a preheating circuit of a heater of a microwave oscillation tube for a preset time when sitting in a driver's seat. Claim 1
Exhaust gas purifying device for automobiles described. 4. A vehicle equipped with a cold start exhaust gas purifying device using microwaves, comprising a circuit and a program for operating only a preheating circuit of a heater of a microwave oscillation tube for a preset time when an engine key is inserted. The exhaust gas purifying apparatus for an automobile according to claim 1. 5. A microwave for heating the catalyst of the exhaust gas purifying apparatus in all states of a vehicle door key being inserted or a door being opened, a driver's seat being seated, or an engine key being inserted. When only the preheating circuit of the heater of the oscillator tube is operated for the preset time, the remaining time of the preset time of the previous process is cut off within the preset time of each of the above states and when the next process is started. The exhaust gas purifying apparatus for an automobile according to claim 1, 2, 3, or 4, comprising a program.