Adjusting and controlling mechanism for EGR rate

Abstract

The invention discloses an adjusting control mechanism for EGR rate. The adjusting and controlling mechanism for EGR rate comprises a venturi tube, a valve nozzle and a displacement controller. The venturi tube comprises an inlet section, an outlet section and a throat portion, wherein the inlet section comprises a valve nozzle inserting section and an inlet conical section; an air inlet is formedin the inner end of the valve nozzle insertion section. The valve nozzle comprises an inserting section of the inlet section, a waste gas inlet conical section and a waste gas outlet section, whereinthe inlet section inserting section is cylindrical, and is connected with the valve nozzle inserting section of the venturi tube in an adaptive mode with moving left and right; the large opening endof the waste gas inlet conical section is connected with the inserting section of the inlet section, and the small opening end is connected with the waste gas outlet section; the waste gas outlet section is cylindrical, and is connected with the throat portion of the venturi tube in the adaptive mode. According to the adjusting and controlling mechanism for EGR rate, the EGR drainage function is achieved, left and right horizontally movement through the valve nozzle mechanism in front of the venturi tube is achieved, so that the control of the EGR rate is realized.

Description

Technical field [0001] The invention relates to the field of engines, in particular to an EGR rate adjustment control mechanism. Background technique [0002] With the upgrade of exhaust emissions, diesel engines are increasingly adopting EGR technology to reduce NOx emissions from the original engine, and exhaust gas is directly introduced from the exhaust turbine into the engine's intake pipe. In order to control the EGR rate, it is usually necessary to install an EGR control valve. At the same time, in order to reduce the operating temperature of the control valve, an EGR cooler must be added to reduce the exhaust gas temperature. [0003] For heavy-duty diesel engines, due to the small speed range, better turbocharger efficiency can usually be achieved when the turbocharger is matched. Due to the high efficiency of the supercharger, the exhaust gas pressure will be lower than the pressure in the intake pipe, and the exhaust gas cannot be introduced. For this problem, many re...

AI Technical Summary

Problems solved by technology

[0005] 1. There are many parts and high cost, and the high cost of EGR valve and EGR cooler is required

[0006] 2. The reliability of the EGR valve is low. If the temperature of the exhaust gas after the EGR cooler is low, it is easy to make coke particles easily adsorb on the EGR control valve, which will cause the valve to block or fail to close; if the temperature of the exhaust gas after the EGR cooler is high, the EGR valve Thermal fatigue reduces service life

Therefore, the failure rate of the EGR valve has always been high

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