JP2004301002A - Engine intake flow control device - Google Patents

Abstract

In a four-cycle engine in which EGR gas is introduced into an intake passage, stable opening of the EGR gas into the intake passage is controlled by controlling opening and closing of an intake flow control valve. Provided is an intake air flow control device for an engine that can simultaneously maintain good combustion performance while avoiding inhibition of an intake pulsation effect due to communication of an EGR gas passage under load.
In an engine having an EGR gas (exhaust gas recirculation gas) passage opened in an intake passage formed having a hollow passage in an intake manifold and an intake port of a cylinder head, an intake flow is supplied to the intake passage. An intake flow control valve for deflecting the air is provided, and the opening of the EGR gas passage can be opened and closed by the intake flow control valve.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is applied to a vehicle engine or the like, and includes an intake passage formed with a hollow passage of an intake manifold and an intake port of a cylinder head, and an intake flow control valve for adjusting a degree of deflection of an intake flow. The present invention relates to an intake air flow control device for an engine having an EGR gas passage opened in a passage.
[0002]
[Prior art]
In a four-stroke engine, the intake air is introduced into the intake passage near the inlet of the intake port in order to improve the fuel consumption rate by improving the combustion performance in the partial load, particularly in the low and medium load operation range, and to maintain the stability of combustion after starting. By installing a flow control valve (tumble valve or swirl valve) and narrowing the intake passage with the intake flow control valve, the intake air flow is generated so that the intake air generates a deflected flow (tumble flow or swirl flow) in the cylinder. Means for deflecting is provided, for example, in Patent Document 1 (Utility Model Registration No. 2605777).
[0003]
[Patent Document 1]
Japanese Utility Model Registration No. 2605777
[Problems to be solved by the invention]
In the four-stroke engine of Patent Document 1, an intake flow control valve is installed in an intake passage near an inlet of an intake port, and the intake flow control valve narrows the intake passage so that intake air generates a deflected flow in a cylinder. By deflecting the intake air flow into the fuel cell, it is possible to improve the fuel consumption rate by improving the combustion performance in a partial load, particularly in a low and medium load operation range, and to maintain the stability of combustion after starting. Does not state that EGR gas is introduced into the intake passage. If EGR gas is introduced into the intake passage as it is, matching between opening and closing of the intake flow control valve and introduction of the EGR gas is not described. Is not performed, there is a possibility that the combustion performance and the charging efficiency are reduced.
And the like.
[0005]
The present invention has been made in view of the problems of the related art, and in a four-stroke engine that introduces EGR gas into an intake passage, controlling the opening and closing of an intake flow control valve to achieve stable combustion when introducing EGR gas into the intake passage; Provided is an intake air flow control device for an engine capable of simultaneously realizing good full load performance while avoiding inhibition of an intake pulsation effect due to communication between an EGR gas passage and an intake passage at high load, including when the throttle is fully opened. The purpose is to do.
[0006]
[Means for Solving the Problems]
The present invention achieves the above object and provides an engine in which an EGR gas (exhaust gas recirculation gas) passage is opened in an intake passage formed by including a hollow passage in an intake manifold and an intake port of a cylinder head. An intake flow control valve for deflecting the intake flow is provided in the intake passage, and the opening of the EGR gas passage can be opened and closed by the intake flow control valve.
[0007]
In this invention, preferably, the intake flow control valve is configured to completely close the opening of the EGR gas passage when the degree of deflection of the intake flow is minimum.
In this invention, it is preferable that the intake flow control valve opens the EGR gas passage and introduces the EGR gas into the intake passage during a deflection degree adjustment period in which the degree of deflection of the intake flow is adjusted to a maximum side. It is constituted as follows.
[0008]
Preferably, a spacer having an intake path communicating the hollow passage and the intake port of the intake manifold is interposed between the intake manifold and the cylinder head. An EGR gas passage is opened and the intake flow control valve is provided.
The intake flow control valve is preferably configured as follows.
That is, the intake flow control valve includes a valve shaft that is rotationally driven by an actuator and a plate-shaped valve body fixed to the valve shaft, and the EGR gas passage is opened and closed by rotation of the valve shaft and the valve body. And a rotary plate-like valve for adjusting the degree of deflection of the intake air flow.
[0009]
According to this invention, in the low load region where the throttle opening is small and the intake air amount is small, the intake flow control valve deflects the intake flow so that the intake generates a deflected flow (tumble flow or swirl flow) in the cylinder. And the EGR gas passage is fully opened.
Thus, the EGR gas is supplied into the cylinder via the intake passage. At this time, since the intake generates a deflected flow in the cylinder by adjusting the opening of the intake flow control valve to the throttle side, a decrease in combustion performance due to the introduction of the EGR gas is suppressed, and stable combustion is achieved. can get.
[0010]
On the other hand, during high load, including when the throttle is fully opened, the intake flow control valve fully opens the intake passage and completely closes the opening of the EGR gas passage to the intake passage. In addition, the EGR gas passage communicating with the intake passage prevents the intake pulsation effect in the intake passage from being impaired.
[0011]
Therefore, according to the invention, when the EGR gas is supplied to the intake passage in a low load region or the like, the intake flow control valve is adjusted to the throttle side, that is, the degree of deflection of the intake flow is adjusted to the maximum side. As a result, it is possible to suppress a decrease in combustion performance due to the introduction of the EGR gas due to the deflected flow of intake air in the cylinder, whereby stable combustion performance can be obtained.
In addition, when the load is high, including when the throttle is fully opened, the intake flow control valve fully opens the intake passage to minimize the degree of deflection of the intake flow, and completely closes the opening of the EGR gas passage to the intake passage. Therefore, it is possible to prevent the intake pulsation effect from being hindered by the inflow of the EGR gas into the intake passage, and to maintain good combustion performance.
As a result, stable combustion when the EGR gas is introduced into the intake passage, and good combustion that avoids the inhibition of the intake pulsation effect due to the communication between the EGR gas passage and the intake passage under a high load, including when the throttle is fully opened, during high load And the full load performance can be maintained at the same time.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail using embodiments shown in the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. It's just
[0013]
FIG. 1 is a cross-sectional view of a main part (a cross-sectional view taken along the line AA in FIG. 2) showing a vicinity of an intake flow control valve mounting portion of a spacer in a vehicle engine according to an embodiment of the present invention, and FIG. FIG. 3 is a sectional view taken along the line BB of FIG. 1, and FIG. 4 is a sectional view taken along the arrow C of FIG. FIG. 5 is an explanatory diagram of the operation of the intake flow control valve.
[0014]
1 to 4, reference numeral 7 denotes an intake port formed in a cylinder head 07, reference numeral 6 denotes an intake manifold integrated with four cylinders (a plurality of cylinders are required), and a cylinder head 07 and an intake manifold 6 are provided between the cylinder head 07 and the intake manifold 6. A four-cylinder (only a plurality of cylinders) integral spacer 1 is fastened by bolts (not shown).
Reference numeral 4 denotes an intake passage formed in the spacer 1, which communicates the intake port 7 of each cylinder with a hollow passage in the intake manifold 6. An intake passage is formed by the hollow passage in the intake manifold 6, the intake passage in the spacer 1, and the intake port 7.
In FIG. 3, reference numeral 2 denotes an EGR passage extending in the axial direction of the engine inside the lower portion of the spacer 1, and an EGR pipe 9 is connected to an inlet thereof. Reference numeral 10 denotes an EGR valve for controlling a passage area of the EGR pipe 9. Reference numeral 3 denotes an EGR hole of each cylinder, which branches off from the EGR passage 2 and opens to the intake passage 4 in the spacer 1.
[0015]
Reference numeral 5 denotes an intake flow control valve (tumble valve) provided in the intake passage 4, which has a function of deflecting the intake flow by adjusting the opening degree of the intake passage 4, that is, the passage area. It comprises a valve shaft 5a extending in the crankshaft direction and rotatably supported by the spacer 1, and a plate-shaped valve body 5b attached to the valve shaft 5a for each cylinder.
When the valve body 5b is in a horizontal position as shown by a two-dot chain line in FIG. 1 and is seated on a valve seat portion 06 formed on the spacer 1, by the rotation of the valve shaft 5a. When the EGR hole 3 is closed and the intake path 4 is fully opened, and the valve element 5b is in a vertical position as shown by the solid line in FIG. It is configured to focus on.
[0016]
A diaphragm actuator 8 reciprocates an output shaft 8a by operating air pressure as shown in FIG. The valve body 5b is a lever fixed to the shaft end of the valve shaft 5a, and has a small end connected to the output shaft 8a. Therefore, as shown by the arrow in FIG. 4, when the output shaft 8a reciprocates by the diaphragm actuator 8, the lever 5b is rotated through the pin 5c, so that the output shaft 8a rotates. Has become.
[0017]
In a vehicle engine provided with the intake air flow control valve device having such a configuration, during low load operation with a small throttle opening and a small intake air amount, or after starting, the diaphragm shaft 8 causes the output shaft 8a and the pin 5c to be driven. The valve shaft 5a is rotated via the lever 5b and the valve body 5b is brought to a vertical position as shown by the solid line in FIG. 1, and the opening degree of the intake passage 4, that is, the passage area is minimized, and the intake air flow is reduced. The degree of deflection is maximized.
[0018]
The valve element 5b has the EGR hole 3 fully open, and as shown in FIG. 5, the EGR valve 10 is open and is in the EGR gas introduction region C, so that the EGR gas flows from the EGR hole 3 through the intake passage. 4.
However, as described above, the intake air flow control valve 5 has an intake air flow control valve operating area (area B in FIG. 5) in which the passage area of the intake air passage 4 is narrowed. The intake air flowing through the intake passage 4 and the intake port 7 is deflected to generate an axial flow (tumble flow) in the cylinder.
By the operation of the intake flow control valve 5, a decrease in combustion performance in the cylinder due to the introduction of EGR gas from the EGR hole 3 is suppressed, and stable combustion can be performed.
[0019]
On the other hand, in the middle of a high load operation region including the time when the throttle is fully opened, that is, in the inactive region of the intake flow control valve in FIG. 5A, the rotation of the valve shaft 5a causes the valve body 5b of the intake flow control valve 5 to move as shown in FIG. The EGR hole 3 is closed at the horizontal position as indicated by the dashed line, and the opening degree of the intake passage 4, that is, the passage area is maximized to minimize the degree of deflection of the intake flow (here, zero).
Therefore, when the intake path 4 is fully opened, the EGR hole 3 is closed, so that the inflow of the EGR gas into the intake path 4 is interrupted. The communication between the EGR gas passages (the EGR holes 3 and the EGR passages 2) and the plurality of intake passages 4 does not impair the intake pulsation effect in all intake passages.
This makes it possible to maintain good combustion performance while avoiding the inhibition of the intake pulsation effect by the EGR gas passage during high load, including when the throttle is fully opened.
Further, since the EGR gas passage for introducing the EGR gas is disposed in the portion of the spacer 1 close to the intake port 7, a response delay of the EGR due to the volume of the intake manifold 6 can be avoided. In addition, when the intake manifold 6 is made of a resin material, thermal deterioration due to EGR gas can be avoided.
[0020]
【The invention's effect】
As described above, according to the present invention, when the EGR gas is supplied to the intake passage in a low load region or the like, the cylinder generated by adjusting the degree of deflection of the intake flow by the intake flow control valve to the maximum side. Due to the deflected flow of intake air in the inside, it is possible to suppress a decrease in combustion performance due to the introduction of the EGR gas, and thereby it is possible to obtain stable combustion performance.
In addition, during high loads, including when the throttle is fully opened, the degree of deflection of the intake flow by the intake flow control valve is minimized, and the opening of the EGR gas passage to the intake passage is fully closed. Disturbance of the intake pulsation effect due to communication between the passage and the intake passage can be avoided, and good combustion performance can be maintained.
As a result, stable combustion at the time of introduction of the EGR gas into the intake passage, and good combustion and full load performance avoiding the inhibition of the intake pulsation effect due to the communication of the EGR gas passage at a high load, including when the throttle is fully opened, Can be simultaneously realized.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view (a cross-sectional view taken along the line AA in FIG. 2) of a main part of a vehicle engine according to an embodiment of the present invention, showing the vicinity of an intake flow control valve mounting portion of a spacer.
FIG. 2 is a front view of the spacer (as viewed in the direction of arrow Z in FIG. 1).
FIG. 3 is a sectional view taken along line BB of FIG. 1;
FIG. 4 is a view taken in the direction of arrow C in FIG. 2;
FIG. 5 is an explanatory diagram of an operation of an intake flow control valve.
[Explanation of symbols]
1 Spacer 2 EGR passage 3 EGR hole 4 Intake path 5 Intake flow control valve 5a Valve shaft 5b Valve 6 Intake manifold 06 Valve seat 7 Intake port 07 Cylinder head 8 Diaphragm actuator 9 EGR pipe 10 EGR valve

Claims (5)

In an engine in which an EGR gas (exhaust gas recirculation gas) passage is opened in an intake passage formed having a hollow passage in an intake manifold and an intake port of a cylinder head, an intake flow for deflecting the intake flow to the intake passage. An intake air flow control device for an engine, further comprising a control valve, wherein the opening of the EGR gas passage can be opened and closed by the intake air flow control valve. 2. The intake flow control of an engine according to claim 1, wherein the intake flow control valve is configured to completely close an opening of the EGR gas passage when a degree of deflection of the intake flow is minimum. apparatus. The intake flow control valve is configured to open the EGR gas passage and introduce the EGR gas into the intake passage during a deflection degree adjustment period in which the degree of deflection of the intake flow is adjusted to a maximum side. The intake air flow control device for an engine according to claim 1, wherein: The intake flow control valve includes a valve shaft that is rotationally driven by an actuator, and a plate-shaped valve body fixed to the valve shaft. The rotation of the valve shaft and the valve body opens and closes the EGR gas passage. 2. The intake air flow control device for an engine according to claim 1, wherein the intake air flow control device is configured as a rotary plate-shaped valve that adjusts a degree of deflection of the intake air flow. A spacer is provided between the intake manifold and the cylinder head, the spacer including an intake passage communicating the hollow passage of the intake manifold and the intake port, and the EGR gas passage is opened in the intake passage of the spacer. 5. The intake flow control device for an engine according to claim 1, wherein the intake flow control valve is provided.

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