JPS58172424A - Intake system in internal-combustion engine - Google Patents

Abstract

PURPOSE:To stabilize combustion in a dual intake port locating a branch point of two ports in a cylinder head by forming an outlet of a sub-intake port such that the horizontal component of flow from the outlet is directed toward the center axis of a cylinder bore. CONSTITUTION:A sub-intake port 4 of two intake ports 3, 4 provided in the region of a cylinder bore 2 is branched from the inner helical peripheral side of a main intake port 3, the branch point 8 being located in a cylinder head. Namely the port 4 is branched from the the introducing portion 3a of said port 3 and the straight portion 4a is extended approximately horizontally and straight and bent down at the terminal end to have a hollow cylindrical outlet 4b having the diameter smaller than that of the cylindrical portion 3b of the port 3 and extend downward parallel to the center axis A of a cylinder bore 2 so that said port 4 is opened to the lower flat end surface of the cylinder head 1. And the outlet 4b determines the direction of flow flowing obliquely out of the outlet 4b toward the center axis A of the cylinder bore 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an intake system of an internal combustion engine, and particularly relates to a structure of an intake system in which a natural intake boat is used, and the branch point of the two boats is located within the cylinder head.

In an internal combustion engine for automobiles, in order to achieve both low fuel consumption and high output performance, the intake boat 1 is made into dual ports independent of each other, one side is a helical port, and the other is a straight boat vcII! It has already been proposed for the developed internal combustion engine.

By the way, when adopting the dual intake boat system, the area of the 8 passages 11 is reduced to reduce fuel adhesion to the wall surface, reduce the amount of unburned hydrocarbons released, and improve drivability.
In order to reduce the space occupied by the intake passage in the cylinder head and to facilitate cooling of the combustion chamber, etc.
It is desirable to construct the own boat into a so-called Siamese boat, which is a twin-shaped boat that branches out from each other within the cylinder head. However, in this case, compared to two independent ports, and compared to a case where a throttle valve is provided on at least one of the 1J hoards, the mutually extending carvings of the two boats are very strong. How the two boats are related to each other and how the flows from the two boats interact within the combustion chamber determines the degree of mixing of fuel and air and the degree of vortex and turbulence formation. Therefore, the combustion speed and combustion stability are also different, and the above is t'.

The degree to which high output performance is achieved will also be greatly affected.

In the present invention, one boat is a helical boat, and the branching point of the two intake boats is inside the cylinder head. The production of icroturbine and the combustion device have been greatly improved, and therefore the low and medium speed range Kk
The object of the present invention is to provide a structure for an internal combustion engine @0 intake system that can effectively achieve low fuel consumption and high output at high speeds.

To achieve this purpose, in the intake system of an internal combustion engine according to the present invention, there is a main intake boat consisting of a helical port and a straight boat.The branch point of the intake boat is located in the cylinder head. A Siamese port is formed, and a copper intake port is connected to the outlet thereof.The horizontal component of the flow is directed toward the center axis of the cylinder pore. Due to this structural pipe and lever, the intake air flowing through the main intake boat is swirled into the combustion chamber.
t- generated, while the horizontal component of the intake air flowing in through the rigid intake port Yt heads toward the center line of the cylinder bore and collides with the swirl fi in a straight direction, generating a large amount of micro-turbulence without weakening the swirl*1- . The coexistence of this swirling flow and small turbulence improves the combustion level to a large one.

The mixture of fuel and air also improves, stabilizing combustion, and increasing lean lint, making it possible to improve fuel efficiency.

A preferred practical example of the intake system of an internal combustion engine according to the present invention will be described below with reference to the drawings.

Figure 1 and! ! FIG. 2 shows the structure of the vicinity of a cylinder head equipped with an intake system according to an embodiment of the present invention. In the figure, 1 is the cylinder head, 2σ cylinder pore, and K[ within the area of cylinder bore 2.

Two intake boats 3.4 and one exhaust boat 5 (there may be two exhaust boats) are provided, each boat 3, 4.5 being connected by an intake valve 6.7 and an exhaust valve, respectively. It is designed to be opened and closed.

One of the two intake boats has an air port, i.e., main intake boat 3, and is longer than the other lk air port, i.e., sub-intake boat 4.1. It has a large connecting cross-sectional area and is formed in a helical shape. The main intake boat is extended from the bottom. The sub-intake boat 4 branches from #dllll in the main intake boat) 30 helical shape 0, and its branching point 8
Between the 0 branch point 8 located in the cylinder head 1 and the intake valves 6, 7, there is no special throttle valve or intake control valve of the 1-car port 3, 4 company.

Main intake hoe) 3f1. ! ! 3aOo! IIK4
As shown in the figure, there is a y-direction 113a extending straight, a spiral ll3b extending downstream lIK, and fIk.
There is a relatively short cylindrical part extending downward from the terminal end of the cylindrical part 3b with a young slope, and the lower end of the cylindrical part opens into the combustion chamber recess 9.

The helical shape 0 inner wall 1i10 of the main intake boat 3 is:
The closer the main intake port 30 approaches the earth wall surface 11 of the passage cross section or the further downstream it is, the more it bulges out toward the helical-shaped outer peripheral side wall surface 12. Therefore, the upper J! The closer it is to 11011, the narrower the flow path is on the downstream side.

Further, the upper portion 11111fl 11 of the main intake boat 3 gradually descends as it goes downstream.

On the other hand, the sub-intake boat 4, which is a straight boat, has a third
The structure shown in the figure and FIG.
The cylindrical part 3C has a hollow cylindrical outlet part 4b with a small diameter and a circular cross section, and extends downward parallel to the center axis A of the cylinder bore 2 to form a large squish area on the opposite side of the spark plug 13. It is open to the lower end flat surface 14 of the cylinder head forming the upper part [1fi]. Therefore, the outlet portion 4bσ is located at the next position t1tK shifted from the central axis A of the cylinder bore 2 in the radial direction. The outlet section 41) ff of the sub-intake boat 4 is relatively short in length, and the flow S is limited to the outlet section 4.
At b, it cannot completely change vertically downward and flows diagonally downward. In this case, the outlet portion 4b is such that the flow obliquely flowing out from the outlet portion 4b is aligned with the central axis AK of the cylinder bore 2.
The direction is determined.

Further, the opening WAK is provided with the aforementioned intake valve 7, and intake air flows into the combustion chamber from the gap between the intake valve 7 and the valve seat. In addition, the straight S extending in the horizontal direction of the auxiliary intake port 4
Soil wall direction of pot 1512. The roots going downstream are descending.

The auxiliary intake boat 4 is separated from the main intake boat 3 by constructing a bulkhead 16, but in this case, the upper wall th15 of the at air boat 4 is the upper wall th15 of the main intake boat 3! The boats are arranged so that they are located at a lower position than t 11 K, and are separated by a bulkhead 16r. The bulkhead 16 extends approximately 1I above the cross section of the passageway of the Siamese boat. It extends to a position close to is 17K, that is, on the upstream side, and is retracted to the downstream side VC@11 below the cross section of one passage. As a rule, the main intake boat 3 and the sub-intake boat No. 3 are separated from each other at the upper position of the passage cross section on the upstream side, and are separated from each other at the lower position of the passage cross section on the downstream side. This means that the and 1 car boat 3
, 4 upper wall END 11. Differences in bulk of Is and bulkhead 16
Due to the structure, #111 intake boat number is located at the lower part of the main intake port 30 passage cross section, that is, the main intake port 30
It branches from the main intake boat 3 at a portion along the F4i plane, and communicates with the clJ'F side at a portion where the partition wall 16 is present.

Next, the operation of the intake system of the internal combustion engine having the above configuration will be explained.

First, let's look at the intake air flowing into the Siamese boat.

The air is separated into the main intake boat 3 and the sub-intake boat number by the partition II 16 K, and then flows into the combustion chamber.

Inside the main intake boat 3, the surface of the partition wall 16, which constitutes the 10 helical-shaped inner cylinder side wall surfaces, bulges out toward the outer periphery @ wall 111112.

The flow is flowing outward, and by constricting the flow and lowering the upper wall surface 11, the force of swirling and descending is increased while increasing the speed. given, the person in the spiral part 3b makes a strong rotation at
After the combustion occurs, the gap between the intake valve 6 and its valve seat is traced back to combustion.
As shown by arrow B in Fig. 2, a strong cross current, so-called swirl, is generated. In the low-medium speed range, the increase in resistance due to the helical flow is not so large, so much of the intake air flows into the main intake boat 3, generating a strong swirl, and therefore, combustion becomes stable in the low-medium speed range.

The lean limit tube can be expanded, promoting lower fuel consumption. The flow on the lower wall surface 18Ke of the main intake boat 3 is as follows.

The rate at which the flow is constricted is smaller than the flow along the earthen wall IN 11 K, and it communicates with the sub-intake boat 4 over a certain distance below the bulkhead 16.

In terms of swirl generation, it does not contribute to the flow along the upper lateral 1i 11 K, but when the flow resistance at the upper part of the passage cross section increases in the high-speed region, from the viewpoint of maintaining the VC and inflow air amount, Compared to the flow along the upper wall surface 11, it contributes more than L and gives a large shadow 461.

On the other hand, the intake air flowing into the sub-intake boat 4.

1rssaaen and bent diagonally downward at the end 1
The cylindrical downward opening 4k)'t 1111 flows into the combustion chamber through the entire gap between the intake valve 7 and its valve seat. This cylinder #
Since the downward opening portion 4b is relatively short, the liquid flows diagonally downward f in the direction of fL, as shown by arrow C in FIG.

It flows out toward the central axis A of the cylinder bore 2. This flow is similar to the helical boat 3, swirling flow KI, angular direction VC
Because it is hot, it does not weaken the swirl.

In addition, it collides with the swirling flow and causes small ridge disturbances called microturbulence tVcQ.

Mile 'C1fi- Burens generation ha, turning fiK
It is also effective to collide with the flow from the X direction, but this will attenuate the swirl. Mayu, swirling flow V
In the direction of Ce, only the swirling flow is promoted, and small ridge turbulence does not occur in the multi-VC. Therefore, it is preferable to apply the ridge perpendicularly to the swirl so as to preserve the circumferential component of the swirl to generate small ridge disturbances, and this has been achieved in the present invention.

As a result, swirl and microturbulence coexist, which improves the mixing of fuel and air within the combustion chamber, distributes the air-fuel mixture uniformly within the combustion chamber, and greatly improves the combustion speed. It will be done. In addition, to generate such a large amount of microturbulence, it is possible to generate two independent boats or install a throttle valve on one side of the boat. Combustion stability is achieved, and it is possible to eliminate the throttle valve in the cylinder head internal ear construction.

It also contributes to ensuring high output in the high speed range for the sub-intake boat 4. In other words, even if the flow resistance on the main intake boat 3 side increases in a helical manner as the high speed range Kt increases, the flow resistance of the straight port auxiliary intake boat 4 does not increase as much as the main intake port 3. In the high-speed range, the secondary flow flowing from the lower section of the main intake boat 3 all the way below the bulkhead 16 and flowing into the sub-intake boat 4 increases, and the amount of intake air flowing through the 1111 intake boat 1'kR increases, achieving high volumetric efficiency. .

High output is ensured.

Since the above is as follows, 1. When using the intake system of the internal combustion engine of the present invention, since the horizontal component of the flow at the outlet of the sub-intake boat is oriented in the direction of the central axis of the cylinder bore, a helical bow is formed. Injects a large amount of microturbience into the combustion chamber without completely weakening the swirl.
! I can do it.

It is said that it is possible to improve the fuel efficiency by improving the engine limit by stabilizing combustion.

High output performance can be obtained even at high speeds. By generating the microturbulence, combustion can be stabilized even if the intake control valve is removed,
Therefore, even if the Iamy's boat system inside the cylinder head is fully adopted, the intake control valve can be eliminated, simplifying the system.
It is possible to reduce rent resistance.

Further, other effects can be obtained by adopting the Iamy's boat configuration within the cylinder head. For example, the partition wall is reduced compared to the two independent boats.

It is possible to reduce the amount of fuel adhering to the wall surface, reduce the release of unburned hydrocarbons, and improve drivability. Furthermore, compared to two independent boats, the space occupied by the water jacket on the upper surface of the combustion chamber wall can be increased, and fuel efficiency can be improved by improving the cooling effect and the knock limit accordingly.

Furthermore, the use of Siamese engines allows the use of a one-piece core during production, which also reduces variations in the performance of produced engines.

4. Simplified drawings a52 #4 FIG. 1 is a vertical cross-sectional view of the vicinity of a cylinder head portion of an internal combustion engine having an intake system according to an embodiment of the present invention.

Is there only a cross-sectional view of the cylinder head in Figure 1 in Figure 2? The perspective view taken out.

It is.

l...Cylinder head.

3...Intake boat.

Literary 0 Introduction.

3b@fist... spiral part.

4... Canopy intake boat.

Pot/0-direct sg.

4b...Cylindrical outlet part.

7.---Intake valve.

11... Same wall surface of the main intake boat.

12. Taste: Outer pigeon wall of main intake boat.

16... Bulkhead.

17-...e Siamese boat entrance.

Claims (1)

[Claims] (1) A Siamese port with a main intake boat consisting of a helical boat and an auxiliary intake boat consisting of a straight boat, with the branching point of both boats located inside the cylinder head.
1. An intake system for an internal combustion engine, characterized in that the horizontal component of the flow from the outlet part of the sub-intake boat is directed toward the central axis a1 of the cylinder pore.