JPH0245474Y2 - - Google Patents

Description

[Detailed explanation of the idea]

INDUSTRIAL APPLICATION FIELD The present invention relates to an intake vortex control device for an internal combustion engine. Prior Art It has been known for a long time that a swirling flow can be generated in a combustion chamber using a helical intake port. and a connected and generally straight-extending inlet passageway. However, if you try to use such a helical intake port to generate a strong swirling flow in the combustion chamber of the engine during low-speed, low-load operation of the engine with a small amount of intake air, the shape of the intake port will have a large flow resistance. A problem arises in that the filling efficiency decreases when the engine is operated at high speed and under high load with a large amount of intake air. In order to solve this problem, a branch path is formed in the cylinder head that branches from the helical intake port inlet passage and communicates with the spiral end of the helical intake port spiral section, and an on-off valve is installed in the branch path. The applicant has already proposed a helical intake port in which an on-off valve is opened during high-speed, high-load engine operation. In this helical type intake port, when the engine is operated at high speed and under high load, a part of the intake air sent into the helical type intake port inlet passage is sent into the helical type intake port spiral part through a branch path, so the intake air flow path is The cross-sectional area increases, thus making it possible to improve charging efficiency, and by closing the branch passage when the engine is operating at low to medium speeds and low to medium loads, the intake air flow flowing in from the branch passage is cut off, and the air flow inside the combustion chamber is reduced. can generate a strong swirling flow.
However, especially when attempting to improve the fuel consumption rate by further reducing the air-fuel ratio during idling, it is necessary to generate a more powerful swirling flow in order to obtain stable combustion. However, although the above-mentioned helical intake port can generate the swirling flow necessary to obtain stable combustion when the engine is operating at medium speed and under medium load, there is a problem in that the swirling flow is too weak during idling operation. Purpose of the invention This invention enables stable idling operation even when the air-fuel mixture is lean during idling by strengthening the swirling flow that occurs during low-speed, low-load engine operation than the swirling flow that occurs during engine speed and medium-load operation. An object of the present invention is to provide an intake air vortex control device that can secure the airflow. Configuration of the Invention The configuration of the present invention includes an intake port defined by an upper wall surface, a lower wall surface, a first side wall surface, and a second side wall surface, the intake port protruding downward from the upper wall surface and spaced apart from each other. A first partition wall and a second partition wall extending in the axial direction of the intake port are provided in the intake port, and a first intake passage is formed between the first side wall surface of the intake port facing the first partition wall and the first partition wall.
A second intake passage is formed between the partition wall and the second partition wall, and a second side wall surface of the intake port facing the second partition wall and a second intake passage are formed between the partition wall and the second partition wall.
A third intake passage is formed between the partition walls, and a first intake control valve that opens during engine high speed and high load operation is disposed within the first intake passage. The second intake control valve for valving is disposed within the second intake passage. Embodiment Referring to FIGS. 1 and 2, 1 is a cylinder head, 2 is an intake port formed in the cylinder head 1, 3 is an intake valve, and 4 is a combustion chamber. a side wall surface 5, a second side wall surface 6 disposed opposite to the first side wall surface 5, and an upper wall surface 7.
and a lower wall surface 8. Furthermore, the intake port 2 includes a semi-cylindrical side wall surface 10 formed around the valve stem 9 of the intake valve 3, and the first side wall surface 5 and the second side wall surface 6 are formed at corresponding ends of the semi-cylindrical side wall surface 10. The parts are smoothly connected to each other. The semi-cylindrical side wall surface 10 bulges outward from the outer peripheral edge of the bulk part of the intake valve 3 near the intersection of the second side wall surface 6 and the semi-cylindrical side wall surface 10. As it approaches the first side wall surface 5, it gradually approaches the outer peripheral edge of the bulk part of the intake valve 3. On the other hand, as shown in FIG.
Connects smoothly to the top end of 0. As shown in FIGS. 1 and 2, the upper wall surface 7
At the top, there are a first partition wall 12 and a second partition wall 1 that protrude downward.
3 are integrally formed, and the first partition wall 12 and the second partition wall 13 extend substantially parallel to each other in the axial direction of the intake port 2. Furthermore, the first partition wall 12 and the second partition wall 12
The partition wall 13 has a substantially constant height over its entire length,
The lower ends of the first partition wall 12 and the second partition wall 13 are the lower wall surface 8
extends to the vicinity of The first partition wall 12 is the intake port 2
The distance between the first partition wall 12 and the first side wall surface 5 is equal to the distance between the first partition wall 12 and the first side wall surface 5. It gradually becomes wider as it approaches. On the other hand, the second partition wall 13 is connected to the first partition wall 12 and the first side wall surface 6.
It extends substantially parallel to the second side wall surface 6 at substantially the center. The upstream end of the second partition wall 13 is located at a downstream end of the first partition wall 12, and the downstream end of the second partition wall 13 is located closer to the semi-cylindrical side wall surface 10 than the downstream end of the first partition wall 12. Located in The downstream portion 14 of the second partition 13 extends along the semi-cylindrical side wall surface 10, and thus the second partition downstream portion 14 has a curved shape that bends inward. The interior of the intake port 6 is divided into three parts by the first partition wall 12 and the second partition wall 13, and a first intake passage 15 that expands toward the downstream side is provided between the first partition wall 12 and the first side wall surface 5. ,
A second intake passage 16 having a substantially uniform width over the entire length is located between the first partition wall 12 and the second partition wall 13.
A third intake passage 17 is formed between the partition wall 13 and the second side wall surface 6 and has a substantially uniform width over its entire length. The width of the entrance of the first intake passage 15 is approximately equal to the width of the second intake passage 16, and the width of the third intake passage 17 is approximately equal to the width of the second intake passage 16.
has a width slightly narrower than that of the second intake passage 16.
As shown in FIG.
5 and thus the first septum 12 is located within the valve stem 9
It extends to the second side wall surface 6 side. As shown in FIGS. 1 to 3, at the entrance of the first intake passage 15 there is a first valve shaped like a butterfly valve.
An intake control valve 18 is disposed, and a second intake control valve 19 similarly in the form of a butterfly valve is disposed at the inlet of the second intake passage 16. These first intake control valve 18 and second intake control valve 19 are connected to the intake port 2.
It extends substantially perpendicularly from the upper wall surface 7 to the lower wall surface 8.
The first intake control valve 18 and the second intake control valve 19 are connected to a first actuator 20 and a second actuator 21, respectively. Opening/closing is controlled by an actuator 21. The first actuator 20 and the second actuator 21 are negative pressure diaphragm devices controlled by engine speed and intake pipe negative pressure;
The first intake control valve 18 and the second intake control valve 19 are controlled to open and close as shown in detail.

[Table] As can be seen from the above table, when the engine is operating at low speed and low load, both the first intake control valve 18 and the second intake control valve 19 are closed as shown by the broken line in FIG. Air flows through the third intake passage 17 along the first side wall surface 6 and the semi-cylindrical side wall surface 10. In this way, when the engine is operating at low speed and low load, the flow path area is narrowed, so the intake air flows at a high speed in the third intake passage 17, and since this intake air flows along the semi-cylindrical side wall surface 10, it is A swirling flow is generated. On the other hand, when the engine is operating at medium speed and under medium load, the second intake control valve 19 is opened, so that intake air flows through the third intake passage 17 and the second intake passage 16 at this time. Therefore, when the engine is operating at medium speed and under medium load, a necessary amount of intake air is supplied into the combustion chamber 4 to increase the flow passage area. Furthermore, at this time, the third intake passage 1
The intake air that has passed through 7 advances along the semi-cylindrical side wall surface 10, and the intake air flowing out from the second intake passage 16 has a semi-cylindrical flow path due to the curved downstream portion 14 of the second partition wall 13. It is deflected in the direction along the side wall surface 10, thus generating a strong swirling flow necessary to obtain stable combustion in this case as well. On the other hand, during engine high-speed, high-load operation, the first intake control valve 18 is also opened, so that the intake air is distributed throughout the intake passage 1.
5, 16, 17, thus high filling efficiency can be obtained. Effects of the invention A strong swirling flow can be generated when the engine is operated at low speed and under low load, especially when idling, so stable combustion can be ensured even if the air-fuel mixture is thinned during idling. Therefore, stable combustion can be ensured even if the idling speed is set low and the air-fuel mixture is made lean, so it is possible to improve the fuel consumption rate while ensuring stable idling operation. On the other hand, when the engine is operating at medium speeds and under medium load, the flow passage area increases, so the required amount of intake air can be supplied into the combustion chamber.Furthermore, a strong swirling flow is generated even at this time, resulting in stable medium speed operation. Medium load operation can be ensured.
Furthermore, during high-speed, high-load operation of the engine, the intake air flows through the entire cross section of the intake port, so high filling efficiency can be obtained, and thus high output can be obtained.

[Brief explanation of drawings]

1 is a plan sectional view of the cylinder head, FIG. 2 is a side sectional view taken along the - line in FIG. 1, and FIG. 3 is a sectional view taken along the - line in FIG. 2... Intake port, 5... First side wall surface, 6...
Second side wall surface, 12...First partition, 13...Second partition, 15...First intake passage, 16...Second intake passage, 17...Third intake passage, 18...First intake control Valve, 19...second intake control valve.

Claims (1)

[Scope of utility model registration request] The intake port has an intake port defined by an upper wall surface, a lower wall surface, a first side wall surface, and a second side wall surface, and has a second section that projects downward from the upper wall surface of the intake port and extends in the axial direction of the intake port at a distance from each other. A first partition wall and a second partition wall are provided in the intake port, and a first intake passage is formed between the first side wall surface of the intake port facing the first partition wall and the first partition wall, and a first intake passage is formed between the first partition wall and the second partition wall. a second intake passage is formed in the second partition wall, and a third intake passage is formed between the second side wall surface of the intake port facing the second partition wall and the second partition wall, and the first intake control valve is opened during high-speed and high-load operation of the engine. Intake vortex flow control for an internal combustion engine, in which a valve is disposed in the first intake passage, and a second intake control valve, which opens during engine high speed and high load operation and during engine speed and medium load operation, is disposed in the second intake passage. Device.