JPS6161918A - Air intake device of internal-combustion engine - Google Patents

Abstract

PURPOSE:To enable high output by improving combustion with generation of strong swirl in a low load area and reducing suction resistance without generation of swirl in a high load area by combination of two intake valves, intake control valve and a bypass port. CONSTITUTION:An air intake system 2 of an engine body 1 is constituted by communicating an intake manifold 24 to a combustion chamber 11 through intake ports 25, 26 and intake valves 3. 4. An intake control valve 51 is provided on the way of the intake port 25, and upper and lower portions of the intake control valve 51 are communicated by a bypass port 28, and the lower opening is just above the intake valve 3 and faced to the tangent direction of a cylinder bore 12. The intake control valve 51 is opened and closed by an intake control system 5 provided with a diaphragm type actuator 52. While, the intake valve 4 releases operation of a valve stop mechanism 7 and opens by a control unit 6 based on the signal from sensors 61, 62 when the engine reaches the predetermined running condition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to an intake device for an internal combustion engine, and more specifically, an internal combustion engine with an improved method for inhaling a mixture into a combustion chamber. The present invention relates to an air intake device.

[Prior Art] In an internal combustion engine, swirl is generated in the air-fuel mixture sucked into the combustion chamber, reducing combustion efficiency. 1. It has become common to eat sea urchins. Methods for generating such swirl include a method in which the intake bow 1 is connected tangentially to the cylinder, a method in which a shroud for generating swirl is attached to the wall surface of the combustion chamber, and the like. This method is effective against the occurrence of swirl, although there are some differences, but it also has the problem of increasing the intake resistance of the air-fuel mixture, which reduces the output performance at high loads. It was causing a decline.

Conventionally, as a method to satisfy the generation of swirl and the improvement of output under high load, for example,
A J-type dual intake system described in Japanese Patent No. 50132 has been proposed. This has a low-load intake system that communicates with the primary passage of the carburetor, and a high-load intake system that communicates with the secondary passage, and intakes air only from the low-load intake system during low and medium loads. In this case, the suction port is narrowed down to increase the flow velocity of intake air, and the old suction port is oriented in the tangential direction of the cylinder to generate a strong swirl.On the other hand, when the load is high, the above In addition to the low-load intake system, some systems also take air from a high-load intake system to increase the amount of intake air and improve output.

However, in recent years, high output has been required for automobile engines, and with the above-mentioned dual intake system, when the engine is running at high speed or under high load, although there is no particular increase in intake resistance in the high-load intake system, In the intake system for low-load applications, the intake port is throttled by the swirl generating mechanism and the intake bow is connected tangentially, which increases intake resistance. There was a problem in that it took a while to achieve high output.

[Object of the Invention] The present invention has been proposed to address the above-mentioned problems, and aims to improve combustion by generating a strong swirl at low speeds and low loads near the idling opening angle I. When driving under medium load, the air-fuel mixture intake W is increased while generating a swirl adapted to driving condition 1, and at these low speeds and low loads, and at medium speeds and medium loads, fuel efficiency is improved mainly by improving combustion. The engine has been designed to improve output and drivability, reduce suction resistance under high loads, and increase the amount of air-fuel mixture intake compared to normal engines.
It is an object of the present invention to provide an improved intake system for an internal combustion engine so that 1 is given.

[Configuration 1 of the Invention 1] To achieve the purpose of this book, the present invention provides two intake valves each having a separate intake port in one combustion chamber.
J, one of the intake valves is equipped with a valve stop mechanism that keeps the intake valve closed depending on the operating state of the engine, and the other intake valve side (the intake port connected to 1
In addition to providing an intake control valve that closes when the valve is closed, a bypass port is also provided to communicate between the upstream and downstream sides of the intake control valve.
The downstream opening of the bypass port is directly upstream of the intake valve and communicates with the combustion chamber in a tangential direction.

[Embodiment 1] Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings.

1 and 2, the case where the intake system of the present invention is applied to an automobile internal combustion engine will be explained. The symbol @1 is the engine body, and the intake system 2 of the engine body 1 is connected to the air cleaner 21. It is difficult to install the vaporizer 22 downstream of the vaporizer 2.
An intake manifold 24 that branches into two is connected downstream of the intake manifold 2, and the first intake manifold 24 is connected to the first intake bow 1 to 25J5 on one side and the second intake port 26 on the other side corresponds to each intake port 25.26. It is configured to communicate with a combustion chamber 11 of the engine body 1 via an intake valve 3 and an intake valve 4, and 41 air in the combustion chamber 11 is extracted by an exhaust valve 9.

” - In the middle of the first intake port 25, an intake control system 5 is installed.
An intake control valve 51 is provided whose opening and closing are controlled by (). The intake control valve 51 is controlled by a diaphragm actuator 52, and a negative pressure in the intake pipe is applied to the diaphragm chamber 53 of the diaphragm actuator 52 through the negative pressure passage 27. This negative pressure operates the dial flam and the link 54 to rotate the support shaft 55 of the intake control valve 51. At this time, the shallower the suction pipe negative pressure, the closer the intake control valve 51 controlled by the diaphragm actuator 52 is to the fully open state, but another control valve 56 is installed in the middle of the negative pressure passage 27. This control valve 5G is involved in controlling the intake control valve 51 via a solenoid 57 which is driven by the control unit 6 when a sensor 61 detects an ignition signal or the like (rotation state) of the engine body 1.

In addition, the first intake bows 1 to 25 are provided with bypass ports 28 that communicate the upstream and downstream of the intake control valve 51, and the downstream opening of the bypass bows 1 to 28 is connected to the intake valve 3. It is located directly upstream and communicates with the cylinder bore 12 in a tangential direction.

In addition, although the intake valve 4 of the second intake port 26 normally does not operate and remains closed, the engine rotation speed detection sensor 6
1 and the self-pressure pressure detection sensor 62, the control unit 6 shuts down the operating state of the engine, and as described later, when the engine reaches a predetermined state (when the soil is under high load), the valve is activated. The operation of the stop mechanism 7 is released and the intake valve 4 is controlled to be closed.

Next, the operation of the intake device having the above structure will be explained based on FIGS. 3 to 6.

In this embodiment, the operation of the intake control valve 51 is in the closed state in the region (1) of the engine shown in FIG. , 6D
and 6iD, that is, at low, medium speeds, or medium-high loads, the valve stop mechanism 7 is set to be in the open state at low, medium speeds, or medium-high loads, and the operation of the valve stop mechanism 7 is set to be in the open state at low, medium speeds, or medium-high loads, which are in the areas of <1) and 61). In the following, the intake valve 4 is set to remain closed.

Therefore, the operating state of the engine can be changed to (i>, (ii
To explain the operation of the intake system in the regions of , the intake valve 4 is closed, and the intake control valve 51 is also open, so the air-fuel mixture from the carburetor 22 is fully opened to the bypass port 1-.
28 and flows into the combustion chamber 11 from the intake valve 3 side J
- As shown by the arrow in Figure 4, a strong swirl of the air-fuel mixture is generated in the combustion chamber, and this strong swirl improves combustion to a large extent, resulting in good fuel efficiency at low loads. It acts as follows.

60, when the engine is at low, medium speed, or medium-high load, the intake valve 4 is in the open state, but the intake control valve 51 is in the open state, as shown in FIG. The air is divided into the intake port 25 and the bypass port 28, flows into the combustion chamber 11 from the intake valve 3, and flows as indicated by the arrow in FIG. Therefore, during steady running, while the airflow of the air-fuel mixture passing through the bypass port 28 generates a mid-air swirl (swirl adapted to operation condition A'1), a part of the air-fuel mixture flows directly from the intake port 25. By being inhaled, the intake capacity of the air-fuel mixture increases, and by kneading, combustion is improved, which improves fuel efficiency, output and drivability, and also increases the inertia effect of the intake air. Since the air-fuel mixture quickly flows into the combustion chamber 11, the engine output is increased.

In the region (iii>), that is, when the engine is under high load, the intake valve 4 is in the operating state as shown in FIG.
Since the intake control valve 51 is also fully open, the air-fuel mixture has a high flow rate and flows into the combustion chamber 11 from the two intake valves 3 and 4 as shown by the arrows in FIG. Since almost no air-fuel mixture flows into the 28, there is no swirl, which greatly reduces the intake resistance.Also, since the air-fuel mixture flows into the two intake valves, the intake amount of the air-fuel mixture is also large (, Significantly higher output of the engine can be achieved.

As described above, at low speeds and low loads near the idling mark, and at medium speeds and medium loads during steady driving, it is possible to improve fuel efficiency and improve output by improving combustion. Since the valves 3 and 4 are independent, the valve timing of one intake valve 3 can be set to a low speed type by reducing the valve timing opening, and the valve timing of the other intake valve 4 can be set to a high speed type by increasing its opening angle. Setting 1- can be done independently, and by overriding the setting in this way, the above (1) and (
In the region 1i), the entire intake valve operates only as a low-speed valve timing, so the actual compression ratio is
In addition, the residual gas rate is reduced and combustion is further improved, and even in the 610 range, the intake valve 4 operates with high-speed valve timing, so compared to engines with normal intake valves. Improve the output of the engine by 1! The effect is also the same.

[Effect of the Invention 1] The present invention provides the above-mentioned J, the combination of the two intake valves, the intake control valve, the J, and the bypass port.
In the low load range of i>, it is possible to generate a strong swirl to improve fuel efficiency by improving combustion, and in the medium load range of Oi), it is possible to generate a moderate amount of swirl by adapting to the operating conditions. In addition, since the intake inertia effect can be obtained, fuel efficiency and output can be improved, and (
In the high load range of tlt), almost no swirl is generated/
Since the two intake valves can greatly reduce intake resistance and increase the amount of intake air, the engine can achieve high output.
All operating ranges of the engine (i), 61) (LiD has the effect of providing high output with low fuel consumption.

Due to the combustion improvement effect of 6L due to the roughly powerful swirl, combustion fluctuations are also reduced, the lean limit and EGR limit are expanded, vibration is reduced, and engine drivability is greatly improved. This effect is also affected.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an example of the present invention applied to an internal combustion engine through an intake system, Fig. 2 is a block diagram of the combustion chamber shown in Fig. 1, and Fig. 3 is a block diagram of an example of the application to an internal combustion engine. An explanatory diagram illustrating the operating range 1 of the engine, Figure 4 is a diagram showing the operating state of the intake system in the area (1) of Figure 3, and Figure 5 is a diagram showing the operating state of the intake system in the area 61) of Figure 3. Fig. 6 shows the operating state in the region of (i:+> in Fig. 3. 1...Engine main body, 11...Combustion Chamber, 12...Shilling bore, 25, 26...To intake bow 1, 28...
Bypass Beau 1~. 3゜4...Intake valve, 5...Intake control valve, 7...Valve stop 1] mechanism. Figure 1

Claims (1)

[Claims] One combustion chamber is provided with two intake valves each having a different intake port, one of the intake valves is provided with a valve stop mechanism that keeps the intake valve closed depending on the operating state of the engine, and the other is provided with a valve stop mechanism that keeps the intake valve closed depending on the operating state of the engine. The intake port that communicates with the intake valve side is provided with an intake control valve that closes at low speeds or low loads, and is also provided with a bypass port that communicates between the upstream and downstream sides of the intake control valve. An intake device for an internal combustion engine, characterized in that the intake device is located directly upstream of a valve and communicates with the combustion chamber in a direction tangential to the combustion chamber.