EGR rate control device based on worm and gear drive variable venturi tubes and control method thereof

Abstract

The invention provides an EGR rate control device based on worm and gear drive variable venturi tubes and a control method thereof. An exhaust gas recirculating system is included, the diesel engine gas inlet end is connected with a first gas inlet pipe and a second gas inlet pipe, the first venturi tube communicates to the first gas inlet pipe, the second venturi tube communicates to the second gas inlet pipe, a first waste gas backflow pipe and a second waste gas backflow pipe communicate to a waste gas backflow main passage, and worms are fixedly connected to the first waste gas backflow pipe and the second waste gas backflow pipe; the control device further comprises a first stepping motor and a second stepping motor, and worm gears are fixed to the output ends of the first stepping motor and the second stepping motor; and a worm and gear mechanism can be used for enabling relative positions of the waste gas backflow pipes and the venturi tubes which are correspondingly arranged tochange so as to change the actual internal areas of the venturi tubes to achieve EGR rate control, on the premise that the diesel engine dynamic property is not changed, the burning temperature in acylinder is reduced, NOx in the waste gas is reduced, and emission is reduced.

Description

technical field [0001] The present invention relates to a method for controlling the EGR rate of a vehicle diesel engine, in particular to a method for controlling the EGR rate of a variable venturi tube driven by a worm gear, which belongs to the technical field of vehicle emission reduction. EGR rate control device with variable venturi tube. Background technique [0002] EGR (Exhaust Gas Recirculation), refers to the technology (method or method) of separating a part of the exhaust gas after combustion in an internal combustion engine, and introducing it into the intake side for recombustion. The main purpose is to reduce nitrogen oxides (NOx) in the exhaust gas and improve fuel consumption when sharing part of the load. The EGR rate is defined as the ratio of the amount of recirculated exhaust gas to the total amount of intake air inhaled into the cylinder. Reasonable control of the EGR rate is extremely important for the purification effect of nitrogen oxides and the e...

AI Technical Summary

Problems solved by technology

[0003] The present invention improves the above-mentioned problems, that is, the technical problem to be solved by the present invention is that when an existing automobile with an exhaust gas recirculation system starts, accelerates or loads, due to the high combustion temperature in the cylinder of the diesel engine, the exhaust NOx The sharp rise will pollute the environment. At the same time, the control accuracy of the EGR rate under different working conditions is not high enough, so that the emission cannot be improved.

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