JPS58113570A - Egr controller for diesel engine - Google Patents

Abstract

PURPOSE:To improve the accuracy of EGR control by performing the EGR control while compensating the rotation, cooling water temperature or lubricant oil temperature and absolute pressure in a suction pipe. CONSTITUTION:In order to achieve EGR corresponding to the rotary angle of a fuel measuring rotary shaft, a regulating valve 4 will control the negative pressure. The original negative pressure is fed by a vacuum pump 6. Under the operational condition such as low rotation, low water temperature or absolute pressure in a low suction pipe, factors matching to said condition is determined and it is calculted in a calculating circuit 7 to control the atmosphere conducting ratio of an electromagnetic valve 2 thus to reduce the lift of EGR valve 1. Consequently EGR is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides exhaust gas recirculation (KGB) for diesel engines.
) regarding equipment.

1. If EGR (i-) is applied to a diesel engine, a reduction in NOx cannot be expected if the amount of EGR is small, and if the amount of 10R is too large, it will lead to an increase in HC and carbon dioxide smoke. Therefore, it is reasonable to consider the amount of EGR just before any one of IC, COT or smoke increases rapidly as the appropriate EGR amount.Based on this idea, the amount of EGR that is appropriate for various engines under various operating conditions is reasonable. As a result of the investigation, we found that the fuel amount G(f) is equal to the intake air amount gGR,l
! It is desirable to do as shown in Figure 1 for the value divided by the amount of intake air (which can be represented by the amount of intake air G (a, 0) when not using gGR), and it depends on the engine speed N. Not done. In Figure 1, the vertical axis represents the EGR rate @gr(%
) Hail.

However, depending on the type of fuel supply #C, the rotation angle of the fuel metering rotary shaft is often not the same with respect to the engine rotation speed, and if the rotation speed is compensated for by taking this into consideration, for example, as shown in Fig. 2 or 3. EGR4li' in the proportions shown in the figure
In addition, in the low water temperature range up to steady operating conditions, it is preferable to reduce the EGR amount from the EGR amount in the steady operating range, as shown in FIG. 4, for example. In addition, in FIG. 4, 2 indicates the water temperature. The absolute pressure inside the intake pipe can reflect the size of the intake airway, and as can be easily inferred from Figure 1: When the amount of intake air decreases, that is, when the absolute pressure P inside the intake pipe decreases. should reduce the KGB amount, for example as shown in FIG. In addition, the fifth
In the figure, P is normal pressure tap water.

In addition, the excess air ratio in the exhaust pipe can inform the amount of air and fuel to be converted by the amount of KGB, and serves as a standard for determining whether the currently available I□B is appropriate. Therefore, instead of the absolute pressure in the intake pipe, the excess air ratio is used to calculate the
It is also possible to perform a 1L amount correction. However, the conventional I
In the GR11 control scissors installation, the above-mentioned 11Ik
There was a problem in that control taking these factors into account was not carried out satisfactorily.

The purpose of the present invention is to solve the problems in the conventional type described above.
It is possible to improve the accuracy of gGB control by performing fill control with compensation for engine speed, cooling water temperature or lubricating oil temperature, and absolute pressure in the intake pipe.

In the present invention, as a first aspect of the invention, an exhaust gas recirculation (IGIL) valve having a diaphragm il, means for supplying pressure to the diaphragm chamber, and a means for supplying pressure to the diaphragm chamber, and a means for supplying pressure to the diaphragm chamber according to a rotation angle of a rotation shaft for fuel quantity. gGR111JII device for a diesel engine, which includes means for detecting operating condition values such as engine speed, cooling water temperature, lubricating oil temperature, and intake pipe absolute pressure; and detecting the operating condition values. Means is provided for releasing a portion of the pressure supplied to the diaphragm chamber to the atmosphere based on the operating condition value detected by the means, thereby causing the EGR
The value is the amount of OR amount E depending on the rotation angle of the rotating shaft for fuel metering.
(0), and a correction function value given by each of the operating condition values.

In the present v4VC, as a $12 form of the invention,
exhaust gas recirculation (KGB) valve with a diaphragm chamber;
In the EGR 1111il device for a diesel engine, which is equipped with a means for supplying pressure to the tum chamber and a means for adjusting the pressure according to the rotation angle of the rotating shaft for fuel metering, the engine speed and the cooling water are controlled. A means for detecting operating condition values such as temperature of at1 lubricating oil, intake air amount and fuel amount, λ value as a ratio of theoretical air/fuel ratio, and based on the operating condition value detected by the operating condition value detecting means. , a means is provided for releasing a part of the pressure supplied to the diaphragm chamber to the atmosphere, so that the final KGB value is equal to the IGR amount E(0) corresponding to one rotation angle of the fuel metering rotary shaft, and the corresponding A diesel engine CJEG & control device is provided which is characterized in that the correction function value is determined by the correction function value given by each of the operating condition values.

The present invention also provides, as a third aspect of the invention, an exhaust gas recirculation (IGiL) valve having one diaphragm, a means for supplying pressure to the diaphragm chamber, and a rotation angle of a rotating shaft for metering the fuel. The EGR control device for a diesel engine includes means for detecting engine rotation speed, cooling water temperature or lubricating oil temperature, and absolute pressure in the intake pipe, and has the following formula: 1=]c(0)X/( N)X/(#)X/(P) ・
・−・−(1) Here, E: Final KGB amount g (0): KGB according to the rotation angle 4C of the rotating shaft for fuel g amount
Quantity f(N): Correction function spread over engine speed f(θ): Correction function due to cooling water @ or lubricating oil temperature f(P): Correction function depending on the absolute pressure in the intake pipe. An EGR control system for a diesel engine is provided, which features a means for releasing a part of the pressure supplied to the diaphragm chamber to the atmosphere so that f CP) becomes a smaller function as f CP decreases. Ru.

IGB of a diesel engine as an embodiment of the present invention
The control device is shown in FIG.

In the apparatus shown in FIG. 6, a leg rating valve 4 is installed on the rotating shaft for metering fuel. The device shown in Figure 6 is
Regi Gourd Rating Pulp 4, EGR Valve 1, Solenoid Valve 2,
Negative pressure switch 3, vacuum pump 6, fuel lever 53, calculation circuit 7, engine speed sensor 81. A water temperature sensor 82, an intake 1 yen absolute pressure sensor 83, and a λ sensor 84 are provided.

In the leg rating valve 4, the case 41 has an air hole and two negative pressure inlets and outlets 9, and a slide shaft 42 having a negative pressure passage inside has airtight and smooth sliding properties with the case 41. It is built to last. Furthermore, a seven-diamond comb 44 is attached to the lower end of the slide shaft 42 to prevent leakage. The outer circumference of the diaphragm 44 is attached to the case 41! 9, case 41. The slide shaft 42 and the diamond 7 rim 44 constitute an airtight chamber 46. A compression spring 43 for fixing the upper end to the case 41° and the lower end to the slide shaft 42 at an initial position t is incorporated inside this airtight i[46]. Diamond 7:P
A compression spring 45 is also incorporated in the airtight chamber 460 opposite the spring 44, and its lower end is fixed to a face cam or special screw 51 connected to the fuel metering rotation shaft s2.

The face cams 1 and 1 special screws 51 are designed to correspond between the fuel level and the EGR amount at the rotation speed of N in @If, 4. The stay 54 is a fuel-lid rotating shaft 52
This is a mounting tool that has a degree of freedom so that the axes of the slide shaft 42 and the face cam or special screw 51 coincide with each other.

EGR*lH, exhaust manifold, intake manifold and t-
There is an airtight m15 formed by a diaphragm 13 inside a case 11 that is installed in the middle of the connecting IGR pipe and has a negative pressure supply hole. When there is no negative pressure in this airtight chamber 15, the diaphragm 13 is pushed back by the return coil spring 12VC, but the valve rod 14 attached to the diaphragm 23vC is simultaneously pushed to block the passage between the exhaust pipe and the intake pipe.

The solenoid valve 2 is VC installed between the negative pressure switch 3 and IGR4PI, 11-)! Atmospheric pressure or negative pressure is supplied to the IcGR valve 1 by a signal from the circuit 7.

The negative pressure switch 3 is installed between the regierating valve 4 and the solenoid valve 2, and is designed to turn on the electric switch at a pressure lower than the wax pressure that the EGR valve can produce MAwJ. The Baquième pump 6 has salt 9 attached to the engine, etc., and while the engine is running, the gGR valve l
The fuel metering lever 53 is capable of supplying a pressure higher than the negative pressure that causes the pump to fully open. Has the function t-.

The calculation circuit 7 has an arithmetic function that can realize equation (1), and calculates the atmospheric pressure and negative pressure per unit time of the solenoid valve 2 and the EGR valve l.
It has a function to control the on/off signal that gives the conduction time ratio. The engine rotation speed sensor 81 is mounted at a location where it is difficult to detect the engine rotation speed. Water temperature sensor 82 is installed at a location where the temperature of engine cooling water can be detected. The intake pipe absolute pressure sensor 83 is installed inside the intake pipe. The λ sensor 84 is installed inside the exhaust pipe.

In the Chin 6 device, the amount of EGR is adjusted according to the rotation angle of the fuel metering rotary shaft at the rotational speed in Fig. 1.
The negative pressure of rating pulp 4#i is controlled.

The original negative pressure is supplied by a vacuum pump 6. formula(
If f (N), f (01f (P), and be done.

For operating conditions such as a rotation speed other than N, low water temperature, and low absolute pressure in the intake pipe, a coefficient that meets the conditions has been determined, and the calculation circuit calculates the coefficient to change the atmospheric conduction of the solenoid valve 2. The ratio is controlled to reduce the lift amount of the EGR valve 1. As a result, EGR'Jl decreases. In addition, instead of the intake pipe internal pressure, the current excess air ratio is detected by a λ sensor 84 installed in the exhaust pipe, and the current excess air ratio is manually input to the calculation circuit 7.
It is also possible to correct the EGR amount.

The negative pressure switch 3 has a calculation circuit that turns on the switch and completely closes the EGR valve 1 when the negative pressure regulated by the regierating valve 4 becomes less than the driving negative pressure of the EGIL valve 1. Sends a signal to 7 and connects the solenoid valve 2 to the atmosphere @
to contact. Now the EGR valve is 10 v! j′M1s
t- Bring the pressure to full atmospheric pressure and bring EGRli to zero.

EG of a diesel engine as another embodiment of the present invention
R system # control device is shown in Figure 7.

In the device shown in FIG. 7, regulating valve 4
An electric mechanism (linear renoid) 47 is directly connected below. For this reason, for example, it is necessary to directly measure the amount of fuel using the position detection sensor 85 of the spill ring. The measured fuel amount is input to the calculation circuit 7 V (V), and the toilet tank including all other toilet tanks is output to the electric mechanism. No correction is necessary,
N, only the correction for the larger rotational speed becomes K. Furthermore, the λ sensor may be attached to either the exhaust pipe or the intake pipe.
When installed in an exhaust pipe, a zirconia element or the like is used to detect O1'#. 4 in the intake pipe!
If it is installed in the evening, use a heat-edge type air flow meter.

By calculating from these measured values and the fuel amount using the following formula, λt)lc can be calculated. 11k of the EGR system is improved.

[Brief explanation of the drawing]

Figures 1 to 5 are diagrams for explaining the present invention in detail, and Figure 1 shows the characteristics of the through EGR rate with respect to the value obtained by dividing the fuel amount by the sum of intake air and EGR gas violet. Figures 2 and 3 are diagrams showing an example of a correction function based on rotation speed, Figure 4 is a diagram showing an example of a correction function based on water temperature, and Figure 5 is a diagram showing an example of a correction function based on intake pressure. FIG. 6 is a diagram showing an EGR control device for a diesel engine as an embodiment of the present invention, and FIG. 7 is a diagram showing an EGR control device for a diesel engine as another embodiment of the present invention. l...EGR valve, 11 valve case, 12...return coil panel, 13...diaphragm, 14...valve stem,
15... Airtight chamber, 2... Solenoid valve, 3 river negative pressure switch, 4... Ray 2 rating valve, 41... Valve case, 42... Slide shaft, 43 River compression spring, 4
4...Diaphragm, 45...Compression spring, 46...
・Bar, 6... Baki tool - mpop/pu, 7... Calculation circuit, e9 "8"... Engine ti11 rotation speed sensor, 82
...Water temperature sensor, 83...Intake pipe pressure sensor, 84.
...λ sensor, 85...Fuel amount sensor. Patent Applicant Japan Auto Parts Research Institute Co., Ltd.% Fraudulent Application Agent Patent Attorney Akira Aoki Patent Attorney Aiyuki Nishidate Patent Attorney Masashi Matsushita Akira Yamaguchi Figure 1 G(+ ＞／G＜ap＞ Figure 2 Figure 4 Figure 15 θ

Claims (1)

[Claims] 1. Exhaust gas recirculation (IGB) with diaphragm i1
lG R111 of a diesel engine comprising a valve, a means for supplying pressure to the tire flam chamber, and a means for adjusting the pressure in accordance with the rotation angle of a rotating shaft for fuel metering.
At the 111 fl engine position, the diaphragm Means is provided for releasing a part of the pressure supplied to the chamber to the atmosphere, and the final EGR1 [depending on the rotation angle of the fuel metering rotary shaft] CGR3ll (of, - and the value of the operating condition) is provided. IG1 control device for a diesel engine, characterized in that the IG1 control device is determined by a correction function value determined by each individual: i Exhaust gas recirculation (gGR) with a diaphragm chamber
, a valve, a means for supplying pressure to the diaphragm chamber, and a means for adjusting the pressure according to the rotation angle of a rotating shaft for fuel metering. temperature, lubricating oil temperature, operating condition values such as λ value as a ratio of intake air amount to fuel amount/stoichiometric air-fuel deposition [means for detecting, and operating condition value detected by the operating condition value detection means] Based on this, a means is provided for releasing a part of the pressure supplied to the diaphragm chamber to the atmosphere, so that the final IGB value is E G RjiE (0) according to the rotation angle of the fuel metering rotary shaft, and , a correction function value given by each of the operating condition values. 3. Exhaust gas recirculation (IGR) with diaphragm chamber
In an EGR control device for a diesel engine, which includes a valve, a means for supplying the diaphragm pressure, and a means for adjusting the pressure according to the rotation angle of a rotary shaft for fuel metering, the engine rotation speed, the cooling water temperature, or the lubrication oil temperature,
It has means for detecting the absolute pressure of intake air, and has the following formula, El(0)xf(N)xf(#)Xf(f)...
...-... (11 Here, E: Final EGR amount 1 (0): EGR amount according to the rotation angle of the rotating shaft for fuel metering f (N): Correction function according to the engine rotation speed / ( $): Correction function according to the cooling water temperature or lubricating oil temperature / (P): Correction function according to the absolute pressure in the intake pipe, which is a function in which fCP) decreases as the pressure decreases. 1. An EGR control device for a diesel engine, characterized in that a means is provided for releasing a part of the pressure generated by VC to the atmosphere. 4. EGR valve equipped with a diaphragm chamber, means for supplying pressure to the diaphragm chamber, means for adjusting the pressure according to the rotation angle of the rotating shaft for fuel metering, engine @ rotation speed detection means, water temperature or lubrication Oil temperature 4A output means, and intake/
EGR of a diesel engine, which has an absolute pressure detection means within g and a means for releasing a part of the pressure supplied to the diaphragm 444 to the atmosphere as shown in the above (type 13).
In the above equation (1) in the control device, f (N) is low rotation speed N, below is 01 high rotation speed N, and l
A complementary f:, @ number such that ! (#) is a correction function such that when the set cooling water temperature (or lubricating oil source) is below θl and 0.01 or above, 1 (however, θ, < e, >), f (P) is 1 at normal pressure, and /(P)≧0, so that the correction function is such that the self-destructive diesel engine Qki G
Rllll1lliU! It. 5. An EGR valve equipped with 4 diaphragms, a means for supplying pressure ft to the diaphragm chamber, a means for adjusting tJ4 according to the rotation angle of the rotating shaft for adjusting the pressure metal fuel, a means for detecting rotation a of the engine, and cooling. In the 4111 device for the 11iGIL1 of a diesel engine, which has a water temperature detection means, an intake air/1 internal absolute pressure detection means, and a hand R for releasing a part of the pressure supplied to the diaphragm storm to the atmosphere as shown in the above-mentioned +11 type. In the above equation (1), f (N) is 0 at low rotational speeds N1 or less, and 1 at high rotational speeds, but between N and the tow, it is lll1s or a bent edge. However, N, < N < N, and 0</(N) < 1. and/ (N)>((N-N, )/(Nt Ns)
) is a correction function such that ! (-) is the set cooling water temperature or lubricating oil temperature e, below 0.
03 or more in, <8. ) with a correction function such that p
l 2 (P) is 1 when the absolute pressure inside the intake pipe is normal pressure, and /
The diesel engine oxam control device according to claim 4, wherein the correction function is such that (P)≧O.