JPH0333463A - Exhaust gas feedback amount control device - Google Patents

Abstract

PURPOSE:To enhance the drive feeling by putting No.1 passage leading from No.1 chamber of an EGR valve to immediately upstream a throttle valve in communication with No.2 passage leading from No.2 chamber to the upstream through No.3 passage with a jet interposed. CONSTITUTION:On the way of a circulative passage 12, an EGR value 14 is installed, which is separated by a diaphragm 16 into No.1 chamber 18 and No.2 chamber 20. The No.1 chamber 18 is communicating to a No.1 port 34 immediate upstream a throttle valve 8 through No.1 passage 26, while No.2 chamber 20 communicating to No.2 port 36 upstream the throttle valve 8 through No.2 passage 28. These No.1 and No.2 passages 26, 28 are put in communication through a No.3 passage 32 with a jet 30 interposed. This jet 30 enables controlling into an exhaust gas feedback amount in accordance with the varying speed of the degree of throttle valve opening, contributing to maintaining the drive feeling favorable even during semi-accelerative or less accelerative operation.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an exhaust gas recirculation amount control device, and particularly relates to an exhaust gas recirculation amount control device that recirculates exhaust gas in an exhaust passage to an intake passage by an EGR valve, and The present invention relates to an exhaust gas recirculation amount control device equipped with a supercharger.

[Prior Art] An exhaust gas recirculation device cleans the exhaust gas by installing EGR pulp in the recirculation passage and controlling the opening and closing of the EGR valve according to the engine operating state when the exhaust gas is recirculated to the intake passage. It is. Additionally, there are two types of superchargers: a turbocharger, which uses exhaust energy, and a supercharger, which is a mechanical type, and both improve output and fuel efficiency.

As the exhaust gas recirculation amount control device, the
There is one disclosed in Publication No. 787.

The exhaust gas recirculation amount control device for a turbocharged engine disclosed in this publication introduces the pressure of air supply compressed by the compressor of the turbocharger into a pressure chamber formed on one side of the responsive body of the differential pressure responsive device. In addition, the pressure chamber formed on the other side of the reaction body has a boat that opens into an air supply passage that is slightly upstream from the fully closed position of the throttle valve and downstream when the throttle valve reaches a predetermined opening degree or more. This reduces the amount of NOx in the exhaust gas and minimizes the reduction in output and drivability.

[Problems to be Solved by the Invention] By the way, in the conventional exhaust gas recirculation amount control device, when the supercharger is provided in the upstream part of the throttle valve, the first Suction pressure slightly upstream of the throttle valve fully closed position, that is, just upstream, is introduced into the chamber, and suction pressure upstream of the throttle valve is introduced into the second chamber, which is the lower chamber of the EGR pulp. It enables wide-area operation.

The exhaust gas recirculation amount control device includes an operating method using sensing as shown in FIG. 3, and an operating method using a vacuum switching valve (VSV) as shown in FIG.

In other words, in the former type of operation using sensing, as shown in FIG.
18 through the first passage 12E3, and the upstream pressure of the throttle valve 108 is introduced into the EGR valve 114.
is introduced into a second chamber 120 by a second passage 128.

Also, the latter vacuum switching valve (VS
The operation method using V) is as shown in Figure 4.
The pressure on the downstream side of the throttle valve 208 is changed to the EGR valve 2.
14 into the first chamber 218 through the first passage 226, and the upstream pressure of the throttle valve 208 is
A third passage 232 is provided, which introduces the pulp 214 into the second chamber 220 through a second passage 228 and communicates the first and second passages 226 and 228.
A vacuum switching valve (V
SV) 240 is provided, and this vacuum switching
The first chamber 2 of the EGR valve 214 is opened by the valve 240.
The pressure introduced into 18 is switched to either the upstream side or the downstream side.

As shown in FIG. 5, in each of the former and latter systems described above, a constant amount of exhaust gas is always recirculated from the exhaust passage to the intake passage, regardless of the rate of change in throttle valve opening during slow acceleration or semi-acceleration. ing.

That is, in order to reduce NOx in the exhaust gas, the same amount of exhaust gas is recirculated during slow acceleration as during half acceleration.

It also maintains a good drive feel during half-acceleration.

However, the same amount of exhaust gas as the amount of exhaust gas recirculated during half-acceleration is recirculated even during slow acceleration at low rotation speed and low negative pressure, causing EGR surge (EGR pulsation) and drive failure during slow acceleration. This has disadvantages in that it damages the ring, worsens riding comfort, and is disadvantageous in practical terms.

[Purpose of the Invention] Therefore, an object of the present invention is, in order to eliminate the above-mentioned disadvantages, to recirculate exhaust gas and to connect the first and second chambers by means of a diaphragm in the middle of the recirculation passage of an engine equipped with a supercharger upstream of the throttle valve. A first passage is provided which opens immediately upstream of the throttle valve and communicates with the first chamber of the EGR valve, and which opens downstream of the supercharger and upstream of the throttle valve. a second passage communicating with the second chamber of the EGR pulp;
By providing a third passage that communicates between the second passages via a jet, the amount of exhaust gas recirculation can be controlled by the jet in accordance with the rate of change in opening of the throttle valve, improving drive feeling during half-acceleration. An object of the present invention is to realize an exhaust gas recirculation amount control device that can maintain a good driving feeling, prevent the occurrence of EGR surge during cruising and slow acceleration, and improve drive feeling.

[Means for Solving the Problems] To achieve this object, the present invention provides an engine that recirculates exhaust gas from the exhaust passage to the intake passage through a recirculation passage and is equipped with a supercharger in the intake passage upstream of the throttle valve. An EGR valve that is separated into a first chamber and a second chamber by a diaphragm is provided in the middle of the recirculation passage,
A first passage is provided that opens immediately upstream of the throttle valve and communicates with a first chamber of the EGR valve, and also opens downstream of the supercharger and upstream of the throttle valve and communicates with a second chamber of the EGR valve. A second passage is provided to
The present invention is characterized in that a third passage is provided that communicates between the first passage and the second passage via a jet.

[Operation] With the above-described configuration, when the engine is driven, the jet in the third passage controls the amount of exhaust gas recirculation in accordance with the rate of change in the opening degree of the throttle valve, thereby reducing the drive fee during half acceleration. In addition to maintaining the ring in good condition, it prevents EGR surge from occurring during cruising and slow acceleration, improving drive feeling.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

Figure 1.2 shows an embodiment of the invention. 1st
In the figure, 2 is an engine, 4 is an intake passage, 6 is a combustion chamber, 8 is a throttle valve, and 10 is an exhaust passage.

A supercharger (not shown) is provided in the intake passage 4 upstream of the throttle valve 8.

Further, a recirculation passage 12 is provided to recirculate exhaust gas from the exhaust passage 10 to the intake passage 4, and an EGR valve 14 is provided in the middle of the recirculation passage 12 to open and close the passage. The EGR valve 14 includes a diaphragm 16 and a first chamber 18 and a second chamber 2 separated by the diaphragm 16.
0, an on-off valve 22 that is connected to the diaphragm 16 and opens and closes the criminal record recirculation passage 12 according to the operation of the diaphragm 16, and a first valve that is arranged to maintain the closed state of the on-off valve 22.
It consists of a second spring 24a124b.

A first passage 26 is provided that opens directly upstream of the throttle valve 8 and communicates with the first chamber 18 of the EGR valve 14, and an EGR valve that opens downstream of a supercharger (not shown) and upstream of the throttle valve 8. 14 second chamber 2
0, and a third passage 32 that communicates between the first passage 26 and the second passage 28 via a jet 30.

Specifically, the first passage 26 is connected to the throttle bar.
The first port 3 opens immediately upstream of the loop 8, that is, slightly upstream of the fully closed position of the throttle valve 8, and downstream when the throttle valve 8 reaches a predetermined opening degree or more.
4 and the first chamber 18 of the EGR valve 14.

Further, the second passage 28 is provided to communicate the second chamber 20 of the EGR valve 14 with a second port 36 that opens downstream of a supercharger (not shown) and upstream of the throttle valve 8. .

Next, the effect will be explained.

When the engine 2 is driven and the operating state is in a half-acceleration state where the throttle valve opening change rate is large, the throttle valve 8 rotates to a predetermined opening or more and opens the first port 3.
4 is slightly downstream of throttle valve 8, and EG
Negative pressure from the first port 34 acts on the first chamber 18 of the R valve 14 via the first passage 26, causing the EGR valve 14 to open and exhaust gas recirculation.

At this time, negative pressure gradually reaches the second passage 28 from the first passage 26 via the jet 30 of the third passage 32,
Negative pressure also acts on the second chamber 20, and the opening degree of the EGR valve 14 is slightly suppressed.

In addition, when the operating state is a slow acceleration with a small throttle valve opening change rate, the throttle valve 8 does not rotate beyond the predetermined opening, resulting in a low rotation and low negative pressure state, and the first port 34 is slightly upstream of the throttle valve 8, and the negative pressure from the first port 34 is EGR.
Even if it acts on the first chamber 20 of the valve 14, the EGR valve 14
cannot be opened, and exhaust gas recirculation cannot take place.

At this time, negative pressure gradually reaches the second passage 28 from the first passage 26 via the jet 30 of the third passage 32.
This negative pressure acts on the second chamber 20 and contributes to maintaining the EGR valve 14 in the closed state.

As a result, during half-acceleration, exhaust gas recirculation is performed in the same manner as before, and the amount of NOx emissions in the exhaust gas can be reduced.
This allows good drive feeling to be maintained.

In addition, since exhaust gas recirculation does not occur during cruising and slow acceleration at low rpm and low negative pressure, it is possible to prevent the occurrence of EGR surges, improve the drive feeling compared to conventional models, and provide a comfortable ride. Therefore, it is practically advantageous.

[Effects of the Invention] As described above in detail, according to the present invention, a diaphragm is used to recirculate exhaust gas and to provide a first gas recirculation path in the recirculation passage of an engine equipped with a supercharger on the upstream side of the throttle valve.
An EGR valve is provided which is separated into a chamber and a second chamber, and a first passage is provided which opens immediately upstream of the throttle valve and communicates with the first chamber of the EGR valve, and which is located downstream of the supercharger and upstream of the throttle valve. A second passage is provided which opens to the second chamber of the EGR valve and communicates with the second chamber of the EGR valve, and a third passage is provided which communicates between the first and second passages via a jet. It is possible to control the amount of exhaust gas recirculation according to the current speed, and the exhaust gas recirculation is carried out in the same way as before at single-side speed, reducing the amount of NOx emissions in the exhaust gas, maintaining a good drive feeling, and reducing the speed at low rotation speeds. - Exhaust gas recirculation is not performed during cruising and slow acceleration under low negative pressure conditions, preventing the occurrence of EGR surges, and improving drive feeling compared to conventional systems, which is advantageous in practice.

[Brief explanation of drawings]

Fig. 1.2 shows an embodiment of the present invention, Fig. 1 is a schematic diagram of an exhaust gas recirculation amount control device, and Fig. 2 shows an engine operating range and an EGR operating range in relation to engine speed and suction pressure. It is a diagram. Figures 3 to 5 show the prior art of this invention, Figure 3 is a schematic diagram of an exhaust gas recirculation amount control device using sensing-based EGR valve operation, and Figure 4 is a vacuum switching valve (VSV). FIG. 5 is a schematic diagram of an exhaust gas recirculation amount control device using an EGR valve operation method using the EGR valve operation method. In the figure, 2 is an engine, 4 is an intake passage, 6 is a combustion chamber, 8 is a throttle valve, 10 is an exhaust passage, 12 is a recirculation passage, 14 is an EGR valve, 16 is a diaphragm, 18
is the first chamber, 20 is the second chamber, 22 is the on-off valve, and 24a is the first chamber.
Spring, 24b is a second spring, 26 is a first passage, 28 is a second passage, 30 is a jet, 32 is a third passage,
34 is a first port, and 36 is a second boat. License Applicant: Suzuki Motor Co., Ltd. Patent attorney
Yoshimi Nishigo Figure 1 Figure 2 Suction pressure Figure 3 Figure 4 20 days Figure 5 Suction pressure

Claims (1)

[Claims] 1. In an engine that recirculates exhaust gas from the exhaust passage to the intake passage through a recirculation passage and is equipped with a supercharger in the intake passage upstream of the throttle valve, the recirculation passage is separated into a first chamber and a second chamber by a diaphragm. E to be
A GR valve is provided, and a first passage is provided that opens immediately upstream of the throttle valve and communicates with a first chamber of the EGR valve, and also opens downstream of the supercharger and upstream of the throttle valve. An exhaust gas recirculation amount control device comprising: a second passage communicating with a second chamber; and a third passage communicating between the first passage and the second passage via a jet.