CN106837613A - A kind of low pressure EGR system of vehicle motor - Google Patents

Abstract

The invention provides a low-pressure EGR system of a vehicle engine, and relates to an EGR system. The low-pressure EGR system of the vehicle engine passes through the engine, wherein the engine has an intake port and an exhaust port, including an intake pipeline, an exhaust pipeline, an EGR pipeline and an electronic supercharger. The air intake pipeline is arranged before the air intake port for gas inflow of the engine. The exhaust pipeline is arranged behind the exhaust port, and is used for exhaust gas discharge of the engine. The EGR line is connected between the intake line and the exhaust line. The electronic supercharger is arranged on one side of the intake pipeline through a pipeline. An electronic supercharger is added to the air intake system of the present invention to increase the response characteristics of the engine under working conditions such as cold start, rapid acceleration, low speed, and low load. After the electronic supercharger is applied to the engine, the invention makes up for the non-supercharging working conditions of the engine such as cold start and low speed and low load, increases the air intake speed of the engine, and shortens the response speed.

Description

A low-pressure EGR system for a vehicle engine

technical field

The invention relates to an EGR system, in particular to a low-pressure EGR system of a vehicle engine.

Background technique

EGR (English full name: Exhaust Gas Recirculation, Chinese translation: Exhaust Gas Recirculation) technology plays an important role in engine fuel saving and emission reduction. With the increasingly stringent fuel consumption and emission regulations, the application of EGR technology in supercharged gasoline engines has gradually become a trend. The application of EGR technology on supercharged gasoline engines will inevitably become a mainstream in engine technology upgrades of major OEMs.

EGR technology applied to supercharged gasoline engines is mainly divided into two technical routes: high-pressure EGR and low-pressure EGR. Gasoline engine high-pressure EGR technology is relatively mature, but its contribution to the fuel consumption of the engine and the vehicle is relatively small. In the development process of the low-pressure EGR system, the slow response speed is an important reason affecting the application of the low-pressure EGR technology. Low-pressure EGR has obvious advantages over high-pressure EGR in terms of working range, knock reduction, and stability. Low-pressure EGR has relative advantages in terms of fuel saving rate, etc., and is currently a cutting-edge and mainstream engine technology upgrade route. However, in the development process of the low-pressure EGR system, slow response speed is an important problem affecting the application of low-pressure EGR technology.

In the existing technical solution, due to the long path of the low-pressure EGR system of the supercharged gasoline engine, the change of the exhaust back pressure affects the EGR exhaust gas flow, resulting in a slow EGR response speed.

Contents of the invention

An object of the present invention is to provide a low-pressure EGR system for a vehicle engine that increases engine response speed.

In particular, the present invention provides a low-pressure EGR system for a vehicle engine, passing through the engine, wherein the engine has an intake port and an exhaust port, comprising:

an air intake pipeline, arranged before the air intake port, for gas inflow of the engine;

An exhaust pipeline, arranged behind the exhaust port, is used to discharge exhaust gas from the engine;

The EGR pipeline is connected between the intake pipeline and the exhaust pipeline, and is used to send part of the exhaust gas discharged from the exhaust pipeline into the intake pipeline after exhaust gas recirculation, so as to reusing a portion of exhaust gases from said engine; and

An electronic supercharger is arranged on one side of the intake pipeline through a pipeline, through which the response characteristics of the engine under conditions such as cold start, rapid acceleration, low speed and low load are increased.

Further, the intake pipeline includes an intake pipeline, and a throttle valve, a turbocharger, a one-way valve, an intercooler, a throttle valve and an intake manifold connected in sequence through the intake pipeline;

Wherein, the electronic supercharger is connected to both sides of the one-way valve through pipelines, and is located before the intercooler, and is connected in parallel with the one-way valve to form a parallel pipeline.

Further, the turbocharger includes two groups of inlet and outlet ports, wherein the first group of inlet and outlet ports are connected to the intake pipeline, and the second group of inlet and outlet ports are connected to the exhaust pipeline;

The intake air enters the turbocharger through the intake port of the first group of inlet and outlet ports of the turbocharger after passing through the throttle valve through the intake pipe, and the turbocharger After the gas is pressurized, it comes out of the gas outlet of the first group of gas inlet and outlet ports, and then flows through the parallel pipeline, the intercooler, the throttle valve and the intake manifold to the The air intake of the engine flows into the engine.

Further, the parallel pipeline is configured such that when the electronic supercharger is working, the one-way valve is automatically closed, and all the gas from the turbocharger flows through the electronic supercharger. flow to the intercooler, and the one-way valve is used to prevent the gas flowing from the electronic supercharger to the intercooler from flowing back through the passage at the one-way valve; when the electronic supercharger is closed , the electronic supercharger is a gas channel, the gas coming out of the turbocharger is divided into two parts, most of the gas flows to the intercooler after passing through the one-way valve, and the remaining part of the gas passes through the The electronic supercharger then flows to the intercooler.

Further, the exhaust pipeline includes an exhaust pipe, and an exhaust manifold, the turbocharger, a front catalytic converter and a rear catalytic converter which are sequentially connected through the exhaust pipe.

Further, one end of the EGR pipeline is connected to the exhaust pipe between the front catalytic converter and the rear catalytic converter, and the other end is connected to the throttle valve and the turbocharger. between the intake ducts,

Wherein, the exhaust gas coming out from the exhaust port of the engine enters the turbocharger after passing through the exhaust manifold, the air inlet of the second group of air inlet and outlet ports of the turbocharger in sequence, and then enters the turbocharger from the first After the gas outlets of the two groups of air inlets and outlets pass through the front catalytic converter, part of the exhaust gas is discharged after passing through the rear catalytic converter, and the other part of exhaust gas enters the EGR pipeline for exhaust gas recirculation and then is sent to the intake pipeline .

Further, according to the flow direction of the exhaust gas, the EGR pipeline includes an EGR filter screen, an EGR cooler and an EGR valve connected in sequence through the pipeline.

Further, a temperature sensor is further arranged between the EGR valve and the EGR cooler, and a pressure difference sensor is arranged on both sides of the EGR valve.

Further, the engine is a three-cylinder supercharged gasoline engine.

In the present invention, an electronic supercharger is added to the air intake system to increase the response characteristics of the engine under working conditions such as cold start, rapid acceleration, low speed, and low load. After the application of the electronic supercharger on the engine, the present invention makes up for the non-supercharged working conditions of the engine such as cold start and low speed and low load, and can increase the air intake speed of the engine and shorten the response speed. In the EGR operating area, the rapid acceleration working condition Under the condition of response lag, the electronic supercharger can also shorten the engine response time by increasing the intake air volume and intake pressure.

When the engine is started, the temperature in the cylinder is low, the fuel atomization effect is poor, and the fuel injection is often too thick. In this operating range, the exhaust gas turbocharger has not yet been involved in the work. After adding the electronic supercharger, it can increase the intake The amount of air in the cylinder promotes full combustion of fuel, improves fuel economy, and reduces engine emissions. In addition, compared with the previous situation where some fuel injections were too rich and part of the fuel was lost, the heat released by the loss of part of the fuel combustion can accelerate engine warm-up. Reduce friction work.

In the engine's full-throttle operating area, the electronic supercharger can increase the intake pressure on the basis of turbocharging, thereby increasing the intake air volume. Therefore, the electronic supercharger can increase the power of the original engine in the full-throttle area. and torque output, which increases the external characteristic performance of the engine.

The engine in the present invention is a three-cylinder supercharged gasoline engine, there is no exhaust interference between the exhaust phases of the three-cylinder engine, and an electronic supercharger is added to the intake system to increase the intake air volume and intake pressure of the engine, which is beneficial to clear the cylinder more quickly The residual exhaust gas in the cylinder improves the scavenging efficiency and reduces the temperature of the gas in the cylinder. When the temperature is lowered, the combustion temperature will be reduced to a certain extent and knocking will be suppressed. At this time, the ignition advance angle can be increased to improve the combustion efficiency.

Description of drawings

Hereinafter, some specific embodiments of the present invention will be described in detail by way of illustration and not limitation with reference to the accompanying drawings. The same reference numerals in the drawings designate the same or similar parts or parts. In the attached picture:

FIG. 1 is a schematic structural diagram of a low-pressure EGR system for a vehicle engine according to an embodiment of the present invention.

detailed description

FIG. 1 is a schematic structural diagram of a low-pressure EGR system for a vehicle engine according to an embodiment of the present invention.

In particular, referring to FIG. 1 , the present invention provides a low-pressure EGR system for a vehicle engine through an engine 5 having an intake port and an exhaust port. The system may include an intake pipeline 2 , an exhaust pipeline 3 , an EGR pipeline 4 and an electronic supercharger 1 . Wherein, the air intake pipeline 2 is arranged before the air intake port, and is used for gas inflow of the engine 5 . The exhaust pipeline 3 is arranged behind the exhaust port, and is used for exhaust gas of the engine 5 to be discharged. The EGR pipeline 4 is connected between the intake pipeline 2 and the exhaust pipeline 3, and is used to send part of the exhaust gas discharged from the exhaust pipeline 3 into the intake pipeline after exhaust gas recirculation 2, so that part of the exhaust gas discharged from the engine 5 is reused. The electronic supercharger 1 is arranged on one side of the intake pipe 2 through a pipeline, through which the electronic supercharger 1 increases the response of the engine 5 under conditions such as cold start, rapid acceleration, low speed and low load characteristic.

The electronic supercharger 1 is added to the air intake system of the present invention to increase the response characteristics of the engine 5 under working conditions such as cold start, rapid acceleration, low speed and low load. After the engine 5 of the present invention is applied with the electronic supercharger 1, the non-supercharged working conditions of the engine 5 such as cold start and low speed and low load can be compensated, the air intake speed of the engine 5 can be increased, the response speed can be shortened, and rapid acceleration can be achieved in the EGR operating region. Under working conditions, the response lags, and the electronic supercharger 1 can also shorten the response time of the engine 5 by increasing the intake air volume and intake air pressure.

When the engine 5 is started, the temperature in the cylinder is low, the fuel atomization effect is poor, and the fuel injection is often too thick. Increase the amount of air entering the cylinder, promote full combustion of fuel, improve fuel economy, and reduce engine emissions. In addition, compared with the previous situation where some fuel injections were too rich and part of the fuel was lost, the heat released by the loss of part of the fuel combustion can accelerate the engine. 5 warm up, reduce friction work.

In the engine 5 full-throttle operating region, the electronic supercharger 1 can increase the intake pressure on the basis of turbocharging, thereby increasing the intake air volume. The power and torque output in the open area increase the external characteristic performance of the engine 5.

As a specific embodiment, as shown in FIG. 1 , the direction indicated by the thin line arrow A in the figure is the flow direction of the gas in the intake pipe 2 . The intake pipeline 2 includes an intake pipeline 21, and a throttle valve 25, a turbocharger 23, a one-way valve 26, an intercooler 22, a throttle valve 24 and an intake air intake pipe 21 connected in sequence through the intake pipeline 21. manifold27. Wherein, the electronic supercharger 1 is connected to both sides of the one-way valve 26 through pipelines, and is connected in parallel with the one-way valve 26 to form a parallel pipeline.

Specifically, the turbocharger 23 includes two groups of air inlets and outlets, wherein the first group of inlets and outlets are connected to the intake pipeline 2 , and the second group of inlets and outlets are connected to the exhaust pipeline 3 . The intake gas flows along the direction indicated by arrow A, flows through the intake pipe 21, passes through the throttle valve 25, and then enters the intake port 231 of the first group of intake and exit ports of the turbocharger 23. The turbocharger 23, after the turbocharger 23 pressurizes the gas, it comes out from the gas outlet 232 of the first group of gas inlet and outlet ports, and then flows through the parallel pipeline, the intercooler The intake port of the engine 5 flows into the engine 5 through the valve 22 , the throttle valve 24 and the intake manifold 27 .

Specifically, at the parallel pipeline, when the electronic supercharger 1 is working, the check valve 26 is automatically closed, and all the gas from the turbocharger 23 flows through the electronic supercharger 1 Then flow to the intercooler 22, the check valve 26 is used to prevent the gas flowing from the electronic supercharger 1 to the intercooler 22 from flowing back through the passage at the check valve 26; when the When the electronic supercharger 1 is closed, the electronic supercharger 1 is a gas passage, and the gas coming out from the turbocharger 23 is divided into two parts, and most of the gas passes through the one-way valve 26 and then flows into the middle. Cooler 22, and the rest of the gas passes through the electronic supercharger 1 and then flows to the intercooler 22.

As a specific embodiment, as shown in FIG. 1 , the direction indicated by the thick arrow B is the flow direction of the gas in the exhaust pipeline 3 . The exhaust pipeline 3 includes an exhaust pipeline 31 , and an exhaust manifold 34 , the turbocharger 23 , a front catalytic converter 32 and a rear catalytic converter 33 are sequentially connected through the exhaust duct 31 .

As a specific example, as shown in FIG. 1 , the direction indicated by the dotted arrow C is the flow direction of the gas in the EGR pipeline 4 . One end of the EGR pipeline 4 is connected to the exhaust pipe 31 between the front catalytic converter 32 and the rear catalytic converter 33, and the other end is connected to the throttle valve 25 and the turbocharger. The intake duct 21 between the devices 23. Wherein, the exhaust gas coming out from the exhaust port of the engine 5 enters the turbocharger 23 after passing through the exhaust manifold 34 and the intake port 233 of the second group of inlet and outlet ports of the turbocharger 23 in sequence, After coming out of the gas outlet 234 of the second group of gas inlet and outlet ports and passing through the front catalytic converter 32, a part of exhaust gas is discharged after passing through the rear catalytic converter 33, and another part of exhaust gas enters the EGR pipeline 4 for exhaust gas recirculation. After that, it is sent into the air intake pipeline 2. According to the flow direction of the exhaust gas, the EGR pipeline 4 includes an EGR filter 43 , an EGR cooler 44 and an EGR valve 45 connected in sequence through the pipeline. A temperature sensor 47 is also provided between the EGR valve 45 and the EGR cooler 44 , and a differential pressure sensor 48 is provided on both sides of the EGR valve 45 .

As a specific embodiment, the engine 5 is a three-cylinder supercharged gasoline engine. The engine 5 in the present invention is a three-cylinder supercharged gasoline engine, there is no exhaust interference between the exhaust phases of the three-cylinder engine, and the increase of the electronic supercharger 1 in the intake system increases the intake air volume and intake pressure of the engine 5, which is conducive to faster Effectively remove the residual exhaust gas in the cylinder, improve the scavenging efficiency, and reduce the temperature of the gas in the cylinder. When the temperature is lowered, the combustion temperature will be reduced to a certain extent and knocking will be suppressed. At this time, the ignition advance angle can be increased to improve the combustion efficiency.

So far, those skilled in the art should appreciate that, although a number of exemplary embodiments of the present invention have been shown and described in detail herein, without departing from the spirit and scope of the present invention, the disclosed embodiments of the present invention can still be used. Many other variations or modifications consistent with the principles of the invention are directly identified or derived from the content. Accordingly, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims (9)

1. a kind of low pressure EGR system of vehicle motor, by engine, wherein, the engine has air inlet and exhaust Mouthful, including：

Air inlet pipeline, before being arranged at the air inlet, the gas for the engine is flowed into；

Gas exhaust piping, is arranged at after the exhaust outlet, for the waste gas discharge of the engine；

EGR line, is connected between the air inlet pipeline and the gas exhaust piping, for the portion that will be discharged at the gas exhaust piping Point waste gas send into after waste gas recycling in the air inlet pipeline, so that the portion of engine discharge is repeated profit With；With

Electron pressurizing unit, it passes through the side that pipeline is arranged at the air inlet pipeline, increases described by the Electron pressurizing unit Response characteristic of the engine under the operating modes such as cold start-up, anxious acceleration, the slow-speed of revolution and underload.

2. the low pressure EGR system of vehicle motor according to claim 1, it is characterised in that

The air inlet pipeline includes admission line, and choke valve, turbocharger, the list being sequentially connected through the admission line To valve, charge air cooler, air throttle and inlet manifold；

Wherein, the Electron pressurizing unit is connected to the both sides of the check valve by pipeline, and before the charge air cooler, with The check valve is in parallel to form parallel pipeline.

3. the low pressure EGR system of vehicle motor according to claim 2, it is characterised in that

The turbocharger includes two groups of air inlet/outlets, wherein first group of air inlet/outlet is connected in the air inlet pipeline, the Two groups of air inlet/outlets are connected in the gas exhaust piping；

The air inlet gas enters after the admission line flows through choke valve into described first group of the turbocharger The air inlet of gas outlet enters the turbocharger, and the turbocharger by described first group after the gas boosting to being entered The gas outlet of gas outlet out, then flows through the parallel pipeline, the charge air cooler, the air throttle and the inlet manifold successively Air inlet to the engine flows into the engine.

4. the low pressure EGR system of the vehicle motor according to Claims 2 or 3, it is characterised in that

It is configured at the parallel pipeline,

When the Electron pressurizing unit works, the check valve is automatically switched off, from turbocharger gas whole out The charge air cooler is flowed to after flowing through the Electron pressurizing unit, the check valve is used to prevent described from Electron pressurizing unit flow direction The gas of charge air cooler is flowed back by the path at the check valve；

When the Electron pressurizing unit is closed, the Electron pressurizing unit is gas passage, from turbocharger gas out Body is divided into two parts, and, by flowing to the charge air cooler after the check valve, remaining portion gas are through the electricity for most of gas The charge air cooler is flowed to after sub- booster again.

5. the low pressure EGR system of the vehicle motor according to claim 3 or 4, it is characterised in that

The gas exhaust piping includes discharge duct, and exhaust manifold, the turbine being sequentially connected by the discharge duct Booster, preceding catalyst converter and rear catalyst converter.

6. the low pressure EGR system of vehicle motor according to claim 5, it is characterised in that

One end of the EGR line is connected at the discharge duct between the preceding catalyst converter and the rear catalyst converter, separately One end is connected at the admission line between the choke valve and the turbocharger,

Wherein, waste gas from the exhaust outlet of the engine out sequentially passes through the exhaust manifold, the turbocharger Enter turbocharger after second group of air inlet of air inlet/outlet, then out pass through from the gas outlet of second group of air inlet/outlet After the preceding catalyst converter, a part of waste gas is discharged after described after catalyst converter, and another part waste gas enters into the EGR line In send into after waste gas recycling the air inlet pipeline.

7. the low pressure EGR system of vehicle motor according to claim 6, it is characterised in that

According to EGR filter screens, cooler for recycled exhaust gas and EGR valve that EGR line described in exhaust gas flow direction includes being sequentially connected with through pipeline.

8. the low pressure EGR system of vehicle motor according to claim 7, it is characterised in that

Temperature sensor is additionally provided between the EGR valve and the cooler for recycled exhaust gas, the both sides of the EGR valve are provided with pressure difference Sensor.

9. the low pressure EGR system of the vehicle motor according to any one of claim 1-8, it is characterised in that

The engine is three cylinder supercharging gasoline engines.