EGR system for small diesel engines

专利摘要:
The present invention relates to an EGR (exhaust gas recirculation device) system for a small diesel engine, and in particular for the reduction of nitrogen oxides in the exhaust gas components of a small diesel engine. In the present invention, the engine control unit reads an input variable of the engine speed, the control lever opening degree and the water temperature, and controls the duty solenoid valve to adjust the back pressure according to the respective operating conditions of the engine, the command of the engine control unit A duty solenoid valve for transmitting a pressure regulating valve for storing the back pressure at all times and transferring the back pressure to the duty solenoid valve if necessary.
公开号:KR19980044747A
申请号:KR1019960062872
申请日:1996-12-07
公开日:1998-09-05
发明作者:정하영
申请人:박병재；현대자동차 주식회사；
IPC主号:

专利说明:

EGR System for Small Diesel Engines
The present invention relates to an EGR (exhaust gas recirculation device) system for a small diesel engine, and in particular for the reduction of nitrogen oxides in the exhaust gas components of a small diesel engine.
In general, the exhaust gas recirculation apparatus is a means for reducing nitrogen oxides in the exhaust gas, which returns a part of the exhaust gas back to the intake tube to lower the maximum temperature when the mixer burns, thereby reducing the amount of nitrogen oxides produced. The amount of exhaust gas returned to the air is controlled by an EGR valve controlled by a negative pressure near the throttle valve and an exhaust pressure in the exhaust pipe.
In such an exhaust gas recirculation apparatus, the EGR introduction amount is the current duty ratio according to the engine speed and the engine load, but even the same duty may actually change the amount of EGR introduced due to external influences. The problem is pointed out that not only the amount of produced can be greatly reduced, but also fuel economy is increased.
In the related art, as shown in Fig. 1, an exhaust gas recirculation apparatus for reducing nitrogen oxides in exhaust gas has been introduced. That is, the engine control unit 21 which reads the input variables of the engine speed, the control lever opening degree and the water temperature, and controls the first solenoid valve 20 for adjusting the VACUUM pressure corresponding to each operating condition of the engine and In addition, the second solenoid valve 22 is added to the first solenoid valve 20 and the engine control unit 21 so as to transfer an appropriate amount of back pressure to the EGR valve 23 more quickly.
In the figure, 24 is an engine, 25 is a vacuum pump, and 26 is an alternator.
The exhaust gas recirculation device of such a configuration does not maintain the constant back pressure, causing fluctuations in the back pressure, and therefore, failing to deliver stable back pressure to the solenoid valves 20 and 22. Rate). That is, since the back pressure from the back pump 25 is transmitted to the solenoid valve side without being stored, there is a problem in that the back pressure fluctuates, resulting in acceleration and EGR shock.
The present invention was created in order to solve the problems of the conventional exhaust gas recirculation device, by using a regulating valve, which is a storage tank of the arm, to prevent the fluctuation of the back pressure, thereby providing a stable back pressure in the duty solenoid valve The aim is to achieve a more accurate EGR rate by delivering.
The present invention for achieving the above object is in the engine control unit for controlling the duty solenoid valve for reading the input variable of the engine speed, the control lever opening degree and the water temperature and adjust the back pressure according to the respective operating conditions of the engine, And a duty solenoid valve for transmitting the command of the engine control unit, a regulating valve for storing the back pressure at all times and transferring the back pressure to the duty solenoid valve if necessary.
1 is a system diagram showing an EGR system of a conventional small diesel engine.
Figure 2 is a schematic diagram showing an EGR system for explaining the present invention.
※ Explanation of code for main part of drawing
1: engine speed, control lever opening and water temperature sensor
2: engine
3: Duty solenoid valve
4: Engine Control Unit
5: EGR valve
6: regulating valve
2 shows a schematic diagram of the present invention, which reads each of the engine speed, the control lever opening degree, and the input variables from the water temperature sensor 1, and the duty solenoid for adjusting the back pressure according to the operating conditions of the engine 2, respectively. The engine control unit 4 which controls the valve 3, the duty solenoid valve 3 which receives the command of the engine control unit 4, and delivers the back pressure to the EGR valve 5, and always back pressure It consists of a regulating valve (6), which stores and transfers the back pressure to the duty solenoid valve (3) if necessary.
In the figure, 6 'is a constant pressure chamber, 7 is a vacuum pump, 8 is an alternator.
In the above, the duty solenoid valve (3) receives the EGR rate set according to the engine speed from the engine control unit (4) as a voltage, and moves the orifice (3 ') in accordance with the received voltage to open the distribution passage, By closing, the back pressure is transmitted to the EGR valve 5, and the regulating valve 6 stores the vacuum pressure generated by the back pump 7 and supplies it to the duty solenoid valve 3 side. The vacuum pump 7 takes an arbitrary negative pressure when generating a vacuum pressure, and the diaphragm in the regulating valve 6 receives a static pressure so that the pressure is immediately delivered to the duty solenoid valve 3 by these pressure differences. In this case, the response time is improved, and the regulating valve 6 can serve as a storage tank, thereby preventing the fluctuation of the back pressure, so that a stable back pressure can be transmitted to the duty solenoid valve 3.
As described above, the present invention installs a regulating valve, which is a storage tank of the back pressure, which does not exist in the conventional exhaust gas recirculation device, between the back pump and the duty solenoid valve, thereby preventing the back pressure from fluctuating. By providing pressure pressure, more accurate EGR rate can be achieved, and at the same time, acceleration and EGR shock is prevented.

权利要求:
Claims (1)
[1" claim-type="Currently amended] An engine control unit (4) that reads the engine speed, the control lever opening and the input variables from the water temperature sensor (1) and controls the duty solenoid valve (3) for adjusting the back pressure according to the respective operating conditions of the engine (4). ), A duty solenoid valve (3) for receiving the command of the engine control unit (4) and delivering the back pressure to the EGR valve (5), and always storing the back pressure and supplying the back pressure if necessary. Regulating valve (6) to be delivered to), and EGR system for a small diesel engine, characterized by consisting of.

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同族专利:

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公开号 | 公开日

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引用文献:

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公开号 | 申请日 | 公开日 | 申请人 | 专利标题

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法律状态:
1996-12-07|Application filed by 박병재, 현대자동차 주식회사

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1996-12-07|Priority to KR1019960062872A

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1998-09-05|Publication of KR19980044747A

优先权:

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申请号 | 申请日 | 专利标题

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KR1019960062872A|KR19980044747A|1996-12-07|1996-12-07|EGR system for small diesel engines|