JP2511253Y2 - Intake passage of intake multi-valve engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a plurality of passages that branch from one intake passage to introduce intake air into the engine combustion chamber, and the openings of these passages to the engine combustion chamber. The present invention relates to an intake passage of an intake multi-valve engine including a plurality of intake ports that form a section and a plurality of intake valves that are combined with the intake ports.

(Prior Art) Conventionally, an engine is known in which a plurality of intake ports that open to an engine combustion chamber are provided and intake introduction is controlled according to an engine operating state.

For example, in Japanese Utility Model No. 63-14830, one intake passage is first branched into two, and one of them is further branched into two so that intake air can be introduced from a total of three ports. When the engine is running at low to medium speeds, the intake air is introduced from the two ports that pass through the one branch passage branching from the intake passage and communicates with it, and at the time of high rotation, the intake air is also introduced from the other branch passage. Intake device is disclosed.

With this configuration, at low and medium speeds, the combustibility can be improved by increasing the flow velocity of intake air and creating swirl, and sufficient intake air can be introduced at high speeds, so charging efficiency can be improved. You can get the effect that you can raise.

(Problems to be Solved) In the structure of the conventionally known intake passage of this type, at the branch passage for branching from one upstream intake passage to the low-medium rotation branch passage and the high-rotation branch passage, The one intake passage constituting the upstream side of the branch point communicates straight with the branch passage for low and medium rotations, and the branch passage for high rotation is substantially straight from the upstream side to the downstream side across the branch point. In order to make the vicinity of the intake passage and the branch passage for low and medium rotations compact, the branch passage is usually configured to branch at a relatively large take-out angle and extend downstream. is there.

However, in this case, the take-off angle of the high-speed branch passage becomes large, and thus the passage resistance becomes large. It is difficult in terms of layout to make the cross section of the high-speed branch passage sufficiently large so as to cover the disadvantage caused by the increase in the passage resistance. As a result, there is a problem that sufficient intake air cannot be introduced from this passage at the time of high rotation in which the intake air flow velocity becomes high, and therefore the output performance can be adversely affected.

(Means for Solving Problems) The present invention is configured in view of the above circumstances, and is capable of sufficiently introducing intake air at a high rotation speed, and thus can improve the charging efficiency. The purpose is to provide an intake passage for the engine.

Another object of the present invention is to provide an intake passage of an intake multi-valve engine that can improve combustibility by generating an appropriate swirl when the engine rotates at low and medium speeds.

The above object of the present invention is to provide an intake passage that branches into two at a predetermined position of the intake system, a first branch passage that branches from the intake passage and introduces intake air into the engine combustion chamber over the entire operating region, and the intake passage. A second branch passage that branches off from the first branch passage and branches off from the first branch passage to introduce intake air in a substantially tangential direction toward a side portion of the engine combustion chamber. A passage and a center passage that branches from the first branch passage and is provided so as to introduce intake air toward a central portion of the engine combustion chamber as compared with the swirl passage, The intake passage is deflected in the direction of the second branch passage on the upstream side near the branch point with the first and second branch passages, and the first branch passage is separated from the second branch passage on the downstream side near the branch point. Person It is deflected can be achieved by the intake passage of the intake multiple valve engine according to claim.

In a preferred aspect of the present invention, the second branch passage is introduced in such a direction as to introduce the intake air toward the center of the engine combustion chamber, that is, in the direction opposite to the flow of the intake air introduced from the swirl passage. The vicinity of the port is formed in the direction to do.

(Operation) According to the present invention, the intake passage is deflected at one end on the upstream side in the vicinity of the branch point to the side of the second branch passage, which is a branch passage for high rotation, and the second branch passage is branched at the deflected portion. A branch point is provided.

Here, when the intake passage is deflected to the second branch passage side,
The center line of the intake passage is curved in the vicinity of the branch point along the flow of intake air from the upstream side thereof in the direction in which the second branch passage is located, and the passage configuration also corresponds to the direction of the second branch passage. It means that it is curved. Therefore, the intake air is already directed toward the second branch passage before reaching the branch point.

The first branch passage forming the branch passage for low to medium rotation is deflected in the direction away from the second branch passage on the downstream side in the vicinity of the branch point. That is, the center line of the first branch passage is curved from the branch point so as to cancel the deflection of the intake passage on the upstream side thereof. As a result, the line connecting the upstream centerline where the bending of the intake passage starts and the downstream centerline where the bending of the first branch passage ends is the intake passage and the first branch when the bending does not occur. Aligns with the centerline of the passage.

Therefore, at the time of high rotation, a part of the intake air that is once deflected to the second branch passage side on the upstream side of the branch point is
Again directed towards the first branch passage.

(Description of Embodiments) Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an example in which the intake passage of the intake multi-valve engine according to the present invention is applied to a V-type 6-cylinder engine.

In FIG. 1, the engine 1 comprises six cylinders, which are divided into two banks of three, arranged so that each cylinder extends in the opposite direction and with a different inclination. ing. The structure of the cylinder block constituting the combustion chamber 2 of the engine, the structure of the cylinder block, and the structure of the exhaust system of the engine are generally well known and have no direct relation to the features of the present invention. Omit it.

Although the present invention relates to the intake system of the engine, and particularly to the structure near the branch portion of the intake passage near the combustion chamber 2, a general description of the intake system will be omitted.

In addition, the intake passage is generally branched by the manifold 3 in order to introduce the intake air from a single air cleaner and then distribute and introduce the intake air into each cylinder. The respective structures are basically the same, and their mutual relations have no particular relation to the features of the present invention. Therefore, one of the intake passage structures will be representatively described, and the description of the other will be omitted.

FIG. 1 shows the vicinity of the mounting portion of the manifold 3 to the cylinder head. The manifold 3 is provided for each of the two banks and is attached to the cylinder head by bolts 3a.

After branching in the manifold 3, the intake passage 3 is
Furthermore, finally, it branches into three and communicates with the combustion chamber 2.

FIG. 2 is a perspective view showing the structure of an intake passage 4 that branches into and communicates with the combustion chamber 2. The combustion chamber 2 has ports for low and medium rotations, and intake air is supplied to the combustion chamber 2. Of the combustion chamber 2 adjacent to the swirl port 5 and the swirl port 5 for introducing the swirl of intake air efficiently to generate the swirl of the intake air. Center port 6 that opens slightly from the center
And a high rotation port 7 which is a port for high rotation and which is opened at a target position of the swirl port 5 in the combustion chamber 2, that is, a position near the side portion of the combustion chamber 2 on the opposite side of the port 5. One intake port is open.

In addition, on the side facing these three intake ports,
Two exhaust ports 8 and 9 are open and the respective exhaust passages 10 and 11 extending from these exhaust ports 8 and 9
Communicates with one collective exhaust passage 12 downstream to form an exhaust system.

Further referring to FIG. 3 together, the intake passage 4 is
In the vicinity of the combustion chamber 2, it branches into two, a first branch passage 13 which is a branch passage for low and medium rotation and a second branch passage 14 which is a branch passage for high rotation.

In this case, the first branch passage 13 has a larger passage cross-sectional area than the second branch passage 14, which is a high-speed branch passage, and is curved to some extent, but is smoothly continuous from the intake passage 4. Extend.

On the other hand, the second branch passage 14 branches off from the intake passage 4 at a relatively large angle, and is thereafter curved so as to extend substantially parallel to the first branch passage 13. The portion that branches from the intake passage 4 into the first branch passage 13 and the second branch passage 14 will be described in detail. In FIG. 3, the center lines L of the intake passage 4, the first branch passage 13 and the second branch passage 14,
An intersection P of L1 and L2 indicates a branch point.

As shown in FIG. 3, the center line L of the intake passage 4 is curved in the direction of the second branch passage 14 by Θ on the upstream side in the vicinity of the branch point P, whereby the intake passage 4 becomes the second branch passage. 14
The direction is biased.

Due to the bending of the intake passage 4, the branch point P is located at a position offset by the distance t from the center line L3 when the bending does not occur.

Then, on the downstream side in the vicinity of the branch point P, the center line L1 of the first branch passage 13 is separated from the second branch passage 14, that is, the curvature of the intake passage 4 on the upstream side of the branch point P is canceled. To the first branch passage 13
Is biased in the original direction.

That is, the center line of the first branch passage 13 coincides with the center line L3 when no curve is generated at a predetermined position downstream of the branch point P.

As shown in FIG. 2, the first branch passage 13 branches further downstream into a swirl passage 15 leading to the swirl port 5 and a center passage 16 leading to the center port 6.

In this case, the first branch passage 13 is deflected in the direction away from the second branch passage 14 on the downstream side in the vicinity of the branch point P, so that the intake air flowing in the first branch passage 13 is discharged from the center passage 16
Rather, it is directed towards the swirl passage 15 and is preferentially introduced towards the swirl port 5.

The three passages of the swirl passage 15 and the center passage 16 which are further branched from the second branch passage 14 and the first branch passage 13 extend substantially in parallel toward the downstream side.
The branch passage 14 is curved slightly toward the center of the combustion chamber 2 near the port. As a result, the intake air is introduced from the high speed port 7 so as to oppose the flow of the intake air introduced from the swirl port.

The operation of the above device will be described. The intake air introduced into the intake passage 4 is once introduced into the second branch passage upstream of the branch point P.
It is oriented in the direction 14 and is again oriented in the original direction after passing the branch point P. Further, the intake air to the second branch passage 14 is introduced into the second branch passage 14 while being directed to the second branch passage 14 at the branch point P.

Since the intake air introduced into the first branch passage 13 is redirected to the original direction downstream of the branch point P as described above, the swirl passage 15 on the side of the center passage 16 is preferentially directed to the swirl passage 15. Introduced to effectively generate swirl at low and medium speeds.

Further, the intake air introduced into the second branch passage 14 by opening the control valve 17 at the time of high rotation is introduced into the combustion chamber 2 from the high rotation port 7. In this case, the second branch passage 14 is directed toward the center of the combustion chamber 2 in the vicinity of the port 7, and is introduced into the combustion chamber 2 so as to cancel the intake flow introduced from the swirl port 5.

(Effect of the Invention) According to the present invention, since the intake air to the high-speed second branch passage is deflected toward the second branch passage on the upstream side in the vicinity of the branch point. It is introduced smoothly without any significant change in flow direction at the point.

Therefore, at the time of high rotation, the passage resistance in the branch passage for high rotation is reduced, and a desired intake air amount can be secured. As a result, the conventional inconvenience in terms of output performance can be eliminated.

Further, conventionally, there is a problem that the swirl is not eliminated by the flow due to the intake air from the swirl port 5 at the time of high rotation, so that the diffusion of fuel particles is impaired and adheres to the wall surface of the combustion chamber. However, according to the above-described configuration of the present invention, the introduction of intake air from the second branch passage is made to oppose the intake flow of the first branch passage for low and medium rotations, so that the intake flow from the swirl port. Therefore, the fuel can be sufficiently diffused to prevent the fuel from adhering to the wall surface of the combustion chamber and ensure good combustion.

[Brief description of drawings]

FIG. 1 is a plan view of an engine body manifold mounting portion according to an embodiment of the present invention, FIG. 2 is a schematic plan view showing positions of intake and exhaust passages around a combustion chamber, and FIG.
FIG. 4 is a cross-sectional view of the vicinity of a branch portion of the intake passage. 1 ... Engine, 2 ... Combustion chamber, 3 ... Manifold, 4
...... Intake passage, 5 ...... Swirl port, 6 ...... Center port, 7 ...... High rotation speed port, 8, 9 ...... Exhaust port,
10, 11 and 12 ... Exhaust passage, 13 ... First branch passage, 14
…… Second branch passage, 15 …… Swirl passage, 16 …… Center passage, L, L1, L2 and L3 …… Center line.

Claims (1)

(57) [Scope of utility model registration request] 1. An intake passage that branches into two at a predetermined position of an intake system, a first branch passage that branches from the intake passage and introduces intake air into an engine combustion chamber over the entire operating region, and a branch from the intake passage. A second branch passage for introducing intake air at high engine speed, and a swirl passage branching from the first branch passage for introducing intake air substantially tangentially toward a side portion of the engine combustion chamber. And a center passage that branches from the first branch passage and is provided so as to introduce intake air toward a central portion of the engine combustion chamber as compared with the swirl passage. The passage is deflected toward the second branch passage at the upstream side near the branch point with the first and second branch passages, and the first branch passage is away from the second branch passage at the downstream side near the branch point. Intake passage of the intake multiple valve engine characterized in that it deflects.