Engine and its device for controlling egr rate

Abstract

The invention discloses an engine and a device for controlling the exhaust gas recirculation (EGR) rate thereof. The device comprises a housing and an adjusting valve, wherein the housing is provided with a back pressure cavity, a first channel, a second channel and an exhaust channel; the first channel and the second channel respectively communicate with an air inlet pipe; the second channel communicates with the exhaust channel; a valve film of the adjusting valve is located in the back pressure cavity, and the back pressure cavity is divided into a first pressure part which communicates with the first channel and a second pressure part which communicates with the external atmospheric pressure by the valve film; one end of a valve core of the adjusting valve is connected with the valve film through an elastic piece, and the other end of the valve core of the adjusting valve is used for adjusting the opening degree of the communication of the second channel and the exhaust channel; under the effect of the pressure difference, the elastic piece is elastically deformed, and the position of the valve core is changed, so that the opening degree of the communication of the second channel and the exhaust channel is adjusted; and the first channel is connected with the air inlet pipe, and when the engine is under different working conditions, different pressure is generated, so that the purpose of adjusting the corresponding EGR rate according to the working conditions of the engine is realized. The device disclosed by the invention adopts a pure mechanical structure, is not provided with a control system, and is extremely high in electromagnetic interference resistance, and the reliability is improved.

Description

technical field [0001] The invention relates to the technical field of engines, in particular to an engine and a device for controlling EGR rate thereof. Background technique [0002] Existing EGR control technology is divided into two types: internal EGR and external EGR. Internal EGR adjusts the gas distribution phase of the camshaft to make the engine scavenging coefficient less than 1 and form a certain amount of residual exhaust gas. External EGR controls EGR by shunting a part of the exhaust gas on the exhaust and introducing it into the intake pipe. The existing technology for external EGR control uses electronic actuators such as electromagnetic poppet valves and butterfly valves, and is calculated by detecting parameters such as intake pipe pressure and air flow. The set opening degree of EGR is controlled by the ECU to open and close the EGR valve. [0003] However, the existing EGR rate control is to control the electronic actuator through the ECU, which is diffi...

AI Technical Summary

Problems solved by technology

[0003] However, the existing EGR rate control is to control the electronic actuator through the ECU, which is difficult to control, involves many variables, and the calibration process is complicated. Since the EGR valve uses electrical components, the reliability is low, the anti-electromagnetic interference ability is poor, and the cost is high.

EGR matching supercharger has high requirements and is difficult to match

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