JPH0721874Y2 - Internal combustion engine intake system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an intake device for an internal combustion engine, and more particularly, to a powerful one in a combustion chamber of a four-valve four-cycle internal combustion engine having two intake and two exhaust valves. The present invention relates to a mechanism for generating a large eddy current.

[Conventional technology]

Conventionally, various contrivances have been made to generate a swirl (swirl) in intake air in a combustion chamber of an internal combustion engine to obtain a favorable combustion state. Among them, a four-valve engine having two intake and exhaust valves each With respect to the above, Japanese Utility Model Laid-Open No. 57-136833 and Japanese Patent Laid-Open No. 57-136833
-62926 and the like have been disclosed.

Among them, the one proposed in Japanese Utility Model Laid-Open No. 57-136833 is exemplified, as shown in FIG. 3, in the cylinder head 1, a symmetrical position with respect to the cylinder center 0 on one diameter line XX of the cylinder 2. Intake valve holes 3a and 3b are provided in the
-Exhaust valve holes 4a and 4b are provided at positions symmetrical with respect to the cylinder center 0 on another diameter line Y-Y intersecting at right angles with -X, and the intake valve holes 3a (3b) and the exhaust valve hole 4a addressed to each one of them.
The intake port 5a (5b) and the exhaust ports 6a and (6b) are arranged in the direction of a line Ma-Ma (Mb-Mb) connecting the centers of (4b).

With the above configuration, the flow of fresh air in the intake stroke as shown in FIG. 3 flows in the left and right intake ports 5a, 5b in the directions of arrows Aa, Ab,
Flows in the opposite direction into the combustion chamber from the intake valve holes 3a, 3b at a position symmetrical with respect to the cylinder center 0, and swirls Ba, Bb are generated and well mixed in the combustion chamber.

[Problems to be solved by the device]

According to the above-mentioned conventional example, since the intake ports are opposed to each other in a normal operating state, a swirl flow is well generated as shown by the arrow in the figure, and the effect of improving combustion can be obtained. Is not effective enough. That is, since the amount of intake air is small when the load is light, it is not possible to generate a strong vortex just by facing the intake ports as described above.

The present invention has been made in view of the above problems, and an object thereof is to provide an intake device for the intake device of the two-valve system having the above-mentioned configuration, which sufficiently generates a swirl flow even at a light load.

[Means for solving the problem]

In order to solve the above problems, in the present invention, two intake valve holes and two exhaust valve holes are provided at symmetrical positions with respect to the center of the cylinder.
In a four-valve four-cycle internal combustion engine that has cylinder heads provided for each of them, and the intake ports are arranged in a line direction connecting the centers of the intake valve holes and the exhaust valve holes for each one of them,
An intake control valve that opens and closes according to the load of the engine and can cover approximately half of the intake port when the chain is opened is provided in the intake port from the intake port center line in one intake port. Also provided is an intake device for an internal combustion engine, wherein the intake device is arranged in the intake passage on the side closer to the cylinder center and in the intake passage on the side farther from the cylinder center than the intake port center line in the other intake port. To do.

[Action]

When the load is light, the intake control valve provided in the intake port is closed, and the intake passage is narrowed to increase the flow velocity of the intake air.The intake control valve is set to be displaced from the center of the intake port. Therefore, the vortex flow generated in the combustion chamber at this time is left-right asymmetrical, and its behavior becomes irregular, as a result of which turbulence of intake air increases and turbulent combustion occurs,
Good combustion condition.

When the load is medium or high, the intake control valve is opened, so that the intake air is not disturbed by the control valve and passes through two intake valve holes that are symmetrically opposed to the center of the cylinder. Vortex flows into the cylinder, and its combustion is promoted.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

The embodiment is shown in FIGS. 1 and 2, FIG. 1 is a sectional view of a main part of the present invention, and FIG. 2 is a sectional view taken along line II-II of FIG.

The arrangement of the intake valve of this embodiment is the same as that of the prior art shown in FIG. 3, the same parts are designated by the same reference numerals, and detailed description thereof will be omitted.

1 is a cylinder head, 2 is a cylinder, 3a, 3b are intake valve holes, 4a, 4b are exhaust valve holes, 5a, 5b are intake ports, 6a, 6
b is an exhaust port, 0 is a cylinder center, XX and YY are orthogonal to each other, and are diameter lines passing through the cylinder center 0, passing through the centers of the intake valve holes 3a and 3b and the exhaust valve holes 4a and 4b, respectively. There is. Aa and Ab are fresh air flows entering the intake ports 5a and 5b, respectively.

The configuration up to this point is the same as the above-mentioned conventional example, but as a feature of the present invention, in addition to the above, the intake ports 5a and 5b are opened and closed according to the load of the engine, and when closed, the intake port 5
Intake control valves 7a, 7 that can cover approximately half of the a, 5b passages
Install b. At this time, the intake control valve is located in one of the intake ports, for example, 5a, in the intake passage on the side closer to the cylinder center 0 and eccentric from the intake port center line Ma-Ma, and in the other intake port 5b, the intake port center. It is arranged in the intake passage on the side farther from the cylinder center 0, eccentric from the line Mb-Mb. In FIG. 1, Da-Da, Db-Db are the positions in which the control valves 7a, 7b are closed, Ea-Ea, Eb-Eb are the positions in which the valves are open, and Ea- in the normal operation. It has the form of Ea, Eb-Eb, and the intake port is fully open.

The control valves 7a, (7b) are connected to the link 1 as shown in FIG.
It is opened / closed by appropriate actuators 15a, (15b) via 3a, (13b). The actuator has, for example, a diaphragm chamber partitioned by a diaphragm into an atmospheric pressure chamber and a variable pressure chamber, and a negative pressure or atmospheric pressure is introduced into this variable pressure chamber according to the operating state of the engine to control valves 7a, (7b). A negative pressure control type actuator that controls the opening and closing of is used. Also, this actuator is controlled by the ECU.

The operation of the intake device having the above-described structure will be described below. When the air load is small and the load is small, the control valves 7a and 7b are set to the positions shown in FIG.
By closing as shown by -Da, Db-Db, the passage of the intake port is narrowed to increase the flow velocity of the intake air sucked from the intake ports 5a, 5b, and a strong swirl flow is generated in the combustion chamber. Further, when the intake control valve 7a is closed, half of the passage of the intake port 5a close to the center of the cylinder is covered, and the control valve 7b covers half of the passage of the intake port 5b on the side far from the center of the cylinder. The fresh air vortexes Ba and Bb flowing into the cylinder do not become rigid vortex vortices, and as shown in the figure, the swirl center moves and causes irregular behavior that deviates from the cylinder center. Disturbance occurs.

Due to the above-mentioned action, a large turbulence of a strong vortex is obtained, turbulent combustion occurs in the combustion chamber, and the combustion at a light load is significantly improved as compared with the conventional case.

[Effect of device]

By implementing the present invention, at the time of light load, by closing the two intake control valves which are asymmetrically arranged, the flow velocity of the intake air in the combustion chamber is increased, and turbulent combustion due to vortex flow with strong irregular behavior is generated. Occurs and a significant improvement in combustion is obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of an intake device according to the present invention and a flow of a vortex flow, FIG. 2 is an intake control valve and its operation explanatory diagram according to a II-II sectional view of FIG. 1, and FIG. FIG. 3 is a cross-sectional view showing a main part of an intake device and a vortex flow according to FIG. 1 ... Cylinder head, 2 ... Cylinder, 3a, 3b ... Intake valve hole, 4a, 4b ... Exhaust valve hole, 5a, 5b ... Intake port, 7a, 7
b ... intake control valve, 0 ... cylinder center, Ma-Ma, Mb-Mb ... intake port center line.

Claims (1)

[Scope of utility model registration request] 1. A cylinder head having two intake valve holes and two exhaust valve holes at symmetrical positions with respect to the center of the cylinder,
In a four-valve four-cycle internal combustion engine in which an intake port is arranged in a line direction connecting the centers of the intake valve hole and the exhaust valve hole for each one of them, in the intake port, open and close according to the load of the engine, An intake control valve that can cover approximately half of the intake port when the chain is opened is provided in the intake passage on one side closer to the cylinder center than the intake port centerline in the other intake port. An intake device for an internal combustion engine, wherein the intake device is arranged in an intake passage on a side farther from a cylinder center than an intake port center line in the port.