CN1093595C - Control system of dual-fuel car for lower exhaustion - Google Patents

Abstract

The present invention relates to a control system of a dual-fuel car for reaching dual standards and lowering exhaustion, which is composed of an oxygen sensor, a speed signal sensor, a cooling water temperature sensor, an air filter, a liquefied petroleum gas (LPG) / air mixing device, a carburetor, an engine, a three-element catalytic converter, an electronic control unit ECU, an LPG evaporating pressure reducer, an LPG storage tank, an LPG gas volume control valve, an electric control gas supply valve of the carburetor. The air-fuel ratio from two sets of fuel supply systems is controlled by the electronic control unit ECU according to the related signals from the sensors. Thus, the higher catalysis conversion efficiency of the three-element catalytic converter is ensured so that whatever the LPG petroleum dual-fuel car uses the LPG or the gasoline, the exhaustion of the car can reach the standard of the existing exhausting regulation (European I number).

Description

Control system of dual-fuel car for lower exhaustion

What the present invention relates to is a kind of liquefied petroleum gas (LPG) (LPG)-gasoline double-fuel automobile double lower exhaustion control system, particularly a kind of LPG-gasoline double-fuel automobile double lower exhaustion control system that adopts technology such as electronic control, three-element catalytic conversion belongs to the automotive engineering field.

In existing technology, document " exploitation of gasoline and liquefied petroleum gas (LPG) dual fuel supply system " (" compact internal combustion engine ", (the 29th volume) the 2nd phase in 2000) described open system, carburetor type LPG-gasoline double-fuel automobile, do not adopt automatically controlled measure, air fuel ratio is not controlled, and can't reach the European I Abgasgesetz that China came into effect from last year, the automobile noxious emission does not reach requirement, and pollution emission is serious.

The objective of the invention is in order to overcome deficiency and the defective in the existing technologies, the new approaches of carburetor type dual-fuel automobile control discharging have been proposed, develop the new control system of a cover, make carburetor type LPG-gasoline double-fuel automobile when using gasoline or LPG, all the air fuel ratio of engine cylinder internal combustion is controlled, made triple mode catalytic converter three kinds of noxious emissions (HC, CO, NOx) catalytic conversion efficient is all than higher, to reach satisfied noxious emission purifying effect.Make automobile when using gasoline or LPG, its discharging all can reach European I Abgasgesetz standard.

Technological scheme of the present invention: mainly comprise lambda sensor, velocity transducer, cooling water temperature sensor, air-strainer, LPG/ air mixer, Carburetor, motor, triple mode catalytic converter, electronic control unit ECU, evaporator and pressure reducer, LPG holding vessel, LPG tolerance control valve, Carburetor aeration valve, petrol tank and solenoid valve etc.

The LPG holding vessel is connected with evaporator and pressure reducer one end by the LPG delivery pipe, the evaporator and pressure reducer the other end links to each other with the LPG suction port of LPG/ air mixer by the LPG pneumatic tube, LPG tolerance control valve is housed in the LPG pneumatic tube, the air intlet of LPG/ air mixer is connected with the outlet of air-strainer by air duct, the outlet of LPG/ air mixer links to each other with the import of Carburetor, the outlet of Carburetor links to each other with motor by the fuel mix letter shoot, engine exhaust port links to each other with triple mode catalytic converter by outlet pipe, lambda sensor is housed on outlet pipe, installation rate sensor and cooling water temperature sensor in the motor, between air-strainer and fuel mix letter shoot, the air by-pass pipe is installed, Carburetor electric controlled gas-compensation valve is installed in the air by-pass pipe, petrol tank joins by solenoid valve and Carburetor, electronic control unit ECU and lambda sensor, velocity transducer, cooling water temperature sensor, Carburetor electric controlled gas-compensation valve, LPG tolerance control valve electrical equipment connects.

The SC sigmal control LPG tolerance control valve that electronic control unit ECU provides according to lambda sensor, velocity transducer, cooling water temperature sensor etc. and the moving law of Carburetor aeration valve.When dual-fuel automobile used gasoline, electronic control unit ECU closed LPG tolerance control valve, makes Carburetor electric controlled gas-compensation valve events, adopted electric controlled gas-compensation, to guarantee near air fuel ratio (air excess factor is generally 0.98～1.02) theoretical air fuel ratio.During Carburetor electric controlled gas-compensation opening of valves, utilize pressure in the fuel mix letter shoot and extraneous pressure difference with replenish air in the fuel mix letter shoot, thereby change air fuel ratio.All these actions of electric controlled gas-compensation valve all are under the control of electronic control unit ECU, carry out according to the signal of relevant sensor.

When dual-fuel automobile used LPG, electronic control unit ECU closed the Carburetor electric controlled gas-compensation valve when using gasoline automatically, then control LPG tolerance control valve.LPG reduces pressure in evaporator and pressure reducer, absorbs heat, vaporizes, and enters the LPG/ air mixer through LPG tolerance control valve, and enters motor after the air mixing.Lambda sensor detects the content of oxygen in the exhaust, electronic control unit ECU is according to relevant sensor signal, by LPG tolerance control valve, control enters the LPG amount of motor, makes the air fuel ratio of LPG mixed gas in the motor be controlled near chemically correct fuel (air excess factor is generally 0.98～1.02).Make the comprehensive conversion efficiency of triple mode catalytic converter reach higher value, obtained good purification after the effect of automobile engine tail gas process triple mode catalytic converter, thereby improved the blowdown situation of vehicle greatly.

Beneficial effect of the present invention: the present invention adopts technology such as electronic control, three-element catalytic conversion, make LPG-gasoline double-fuel automobile when using gasoline and LPG, discharging all can reach the European I Abgasgesetz standard that China implemented in 1999, broken through of the dependence of LPG-gasoline double-fuel automobile to the LPG gas station, make the dual-fuel automobile operation more flexible, starting performance is good, the control accuracy height, control system is reliable, has solved the idling matching problem when automobile uses different fuel simultaneously.

The invention will be further described below in conjunction with accompanying drawing:

Fig. 1 is a structure principle chart of the present invention.

As shown in Figure 1, concrete enforcement of the present invention is: mainly comprise lambda sensor 1, velocity transducer 2, cooling water temperature sensor 3, Carburetor electric controlled gas-compensation valve 4, LPG tolerance control valve 5, air-strainer 7, LPG/ air mixer 9, Carburetor 10, motor 14, triple mode catalytic converter 16, electronic control unit ECU 17, evaporator and pressure reducer 18, LPG holding vessel 20, LPG solenoid valve 21, petrol tank 12 and gasoline solenoid valve 11 and relevant connected element etc.

LPG holding vessel 20 is connected with evaporator and pressure reducer 18 1 ends by the LPG delivery pipe 19 that LPG solenoid valve 21 is housed, evaporator and pressure reducer 18 the other ends link to each other with the LPG suction port of LPG/ air mixer 9 by LPG pneumatic tube 22, LPG tolerance control valve 5 is housed in LPG pneumatic tube 22, the air intlet of LPG/ air mixer 5 is connected by the outlet of air duct 8 with air-strainer 7, the outlet of LPG/ air mixer 9 links to each other with the import of Carburetor 10, the outlet of Carburetor 10 links to each other with motor 14 suction ports by fuel mix letter shoot 13, motor 14 relief openings link to each other with triple mode catalytic converter 16 by outlet pipe 15, lambda sensor 1 is housed on outlet pipe 15, installation rate sensor 2 and cooling water temperature sensor 3 in the motor 15, between air-strainer 7 and fuel mix letter shoot 13, air by-pass pipe 6 is installed, Carburetor electric controlled gas-compensation valve 4 is installed in air by-pass pipe 6, petrol tank 12 joins electronic control unit ECU17 and lambda sensor 1 by solenoid valve 11 and Carburetor 10, velocity transducer 2, cooling water temperature sensor 3, Carburetor electric controlled gas-compensation valve 4, LPG tolerance control valve 5 electrical equipment connect.

The SC sigmal control LPG tolerance control valve 5 that electronic control unit ECU17 provides according to lambda sensor 1, velocity transducer 2, cooling water temperature sensor 3 etc. and the moving law of Carburetor electric controlled gas-compensation valve 4.When dual-fuel automobile uses gasoline, LPG solenoid valve 21 cuts out, gasoline solenoid valve 11 is opened, electronic control unit ECU17 closes LPG tolerance control valve 5, make 4 actions of Carburetor electric controlled gas-compensation valve, adopt electric controlled gas-compensation, to guarantee near air fuel ratio (air excess factor is generally 0.98～1.02) theoretical air fuel ratio.When Carburetor electric controlled gas-compensation valve 4 is opened, utilize pressure in the fuel mix letter shoot 13 and extraneous pressure difference with replenish air in fuel mix letter shoot 13, thereby change air fuel ratio.All these actions of Carburetor electric controlled gas-compensation valve 4 all are under the control of electronic control unit ECU17, carry out according to the signal of relevant sensor.

When dual-fuel automobile used LPG, LPG solenoid valve 21 was opened, and gasoline solenoid valve 11 cuts out, and electronic control unit ECU17 closes the Carburetor electric controlled gas-compensation valve 4 when using gasoline automatically, then control LPG tolerance control valve 5.LPG reduces pressure in evaporator and pressure reducer 18, absorbs heat, vaporizes, and enters LPG/ air mixer 9 through LPG tolerance control valve 5, and enters motor 14 after the air mixing.Lambda sensor 1 detects the content of oxygen in the exhaust, electronic control unit ECU17 is according to relevant sensor signal, by LPG tolerance control valve 5, control enters the LPG amount of motor 14, makes the air fuel ratio of LPG mixed gas in the motor 14 be controlled near chemically correct fuel (air excess factor is generally 0.98～1.02).Make the comprehensive conversion efficiency of triple mode catalytic converter 16 reach higher value, 1 of automobile engine 4 tail gas have obtained good purification after acting on through triple mode catalytic converter 16, thereby improve the blowdown situation of vehicle greatly.

Claims (1)

1. A low-emission control system for dual-fuel vehicles, including a speed sensor (2), a cooling water temperature sensor (3), an air filter (7), an LPG/air mixer (9), a carburetor (10 ), engine (14), evaporator (18), LPG storage tank (20), LPG solenoid valve (21), gasoline tank (12) and gasoline solenoid valve (11) and related connecting parts, etc., it is characterized in that , also includes oxygen sensor (1), carburetor electronically controlled air supply valve (4), LPG gas volume control valve (5), three-way catalytic converter (16), electronic control unit ECU (17), LPG storage tank ( 20) Connect one end of the evaporator decompressor (18) through the LPG delivery pipe (19) equipped with the LPG solenoid valve (21), and the other end of the evaporator decompressor (18) is connected to the LPG/air The LPG air inlet of the mixer (9) is connected, and the LPG gas volume control valve (5) is installed in the LPG air delivery pipe (22), and the air inlet of the LPG/air mixer (5) passes through the air pipe (8) and the air filter The outlet of the cleaner (7) is connected, the outlet of the LPG/air mixer (9) is connected with the inlet of the carburetor (10), and the outlet of the carburetor (10) is connected to the engine through the fuel mixture delivery pipe (13). (14) air inlet links to each other, engine (14) exhaust port links to each other with three-way catalytic converter (16) by exhaust pipe (15), oxygen sensor (1) is housed on exhaust pipe (15), engine ( 15) A speed sensor (2) and a cooling water temperature sensor (3) are installed inside, and an air bypass pipe (6) is installed between the air filter (7) and the fuel mixture delivery pipe (13). The carburetor electric control air supply valve (4) is installed in the pipe (6), the gasoline tank (12) is connected with the carburetor (10) through the solenoid valve (11), the electronic control unit ECU (17) and the oxygen sensor (1), speed sensor (2), cooling water temperature sensor (3), carburetor electric control air supply valve (4), LPG air volume control valve (5) electrical connections.

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