JPS58150025A - Intake passage in internal-combustion engine - Google Patents

Abstract

PURPOSE:To enhance the manufacturing accuracy of a port arrangement in a combustion chamber, in an intake port arrangement provided with a main intake port of helical shape and a subintake port of straight shape, by making both ports in a Siamease twin shape having their branching part disposed in the cylinder. CONSTITUTION:Two intake ports 3, 4 and one exhaust port 5 are opened to the area in a cylinder head 1, corresponding to a cylinder bore 2, and are opened and closed by means of intake valves 6, 7 and an exhaust valve 8, respectively. Of the two intake ports 3, 4, the main intake port 3 has a cross-sectional passage-area larger than that of another subintake port 4, and is formed in a helical shape. That is, the main intake port 3 constitutes a substantially linear induction part 3a on the inlet side and a spiral part 3b on the outlet side, extending continuously to the induction part 3a, and the subintake port 4 is formed in a substantialy straight shape. Further, the subintake port 4 is branched off in a fork-like shape from the inner peripheral side of the induction part, thereby both ports 3, 4 are constituted as a siamease twin shape port arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to #Ii structure of an intake passage of an internal combustion engine employing a dual intake system.

Conventionally, @l is equipped with an intake boat and a second intake port, and wc
Flow path ilfiMIt from the 1st intake port to the 2nd intake port
The main intake boat is formed into a large helical shape.

And a throttle valve is provided on the sub-intake boat of the second intake port, C
With the tVH construction, the throttle valve is fully closed in the low and medium speed range of the engine, and the intake air is supplied to the combustion chamber via the all-helical main intake boat, thereby generating a strong vortex RYr in the combustion chamber to ensure stable combustion. - In high-speed ranges, the throttle valve is fully opened to supply intake air into the combustion chamber from both the main intake boat and the auxiliary intake boat, increasing charging efficiency and achieving high output. An internal combustion engine has been proposed. In this type of intake passage, we decided to provide a throttle valve.

Since this increases the flow resistance of the air-fuel mixture and complicates the entire structure, an intake passage structure consisting of two independent ports has been proposed in which the t- and rCh throttle valves are removed.

However, in the above-mentioned conventional dual intake boat where the main intake port is connected to the main intake port, and in the structure of the intake passage without a throttle valve, the flow to the sub intake boat in the low and medium speed range is low even without the throttle valve t. The Kh main intake port and the auxiliary intake boat were configured as independent intake passages to prevent imbalance, and for this reason, independent cores had to be used in the manufacture of the intake passages, which inevitably resulted in poor manufacturing accuracy. There is a problem in that, in the case of mass production, variations in manufacturing accuracy may cause variations in performance.

In addition, in the case of two independent boats, the wall area of the Fi1 passage becomes large, and the amount of fuel flowing into the wall increases.

It is necessary to consider reducing the release of unburned hydrocarbons and improving drivability, and furthermore, the space occupied by the intake passage in the cylinder head becomes large.

There was also the problem that it was necessary to consider improving the cooling performance of the combustion chamber.

In order to eliminate such variations in manufacturing accuracy, the present invention makes it possible to use an integral Q'J core,
The purpose of the present invention is to provide an intake passage structure 1 which can reduce the passage wall area and the space occupied by the intake passage by 1 smaller than that of two independent boats.

In addition, the present invention provides an intake passage which is manufactured using the above-mentioned integrated core and which ensures sufficient flow to the helical port in the low and medium speed range, even in an intake passage with a compact passage. Another purpose is to provide a complete structure.

To achieve these objects, the intake passage of the internal combustion engine of the present invention includes a main intake passage consisting of a helical port forming the intake passage.

The auxiliary intake passages made of straight boats are mutually formed into twin boats, so-called Siamese boats, and the branching portion of the Siamese ports is located within the cylinder head. 17'h & The intake manifold connected to the Siamese boat is preferably oriented toward the helical outer circumference of the main intake boat at its outlet to the Siamese boat. This structure, in other words, the Iamies boat inside the cylinder head, makes it possible to use an integrated core and make the boat more compact, improving production accuracy, reducing unburned hydrocarbons, and improving drivability. By adopting an inflow-oriented shape, a sufficient flow is ensured for the helical main intake boat in the low-to-medium speed range, even though the Iamy's port in the cylinder head is a component of the engine.

A preferred embodiment of an intake passage for an internal combustion engine according to the present invention will be described below with reference to all drawings UkJvi7.

1 and 2 show an intake passage according to an 8g1 embodiment of the present invention. In the figure, lF′i cylinder head, 2
Fi is indicated by an imaginary line at the cylinder bore of each cylinder. In this region within the cylinder bore 2 there are two intake boats 3.
4 and two exhaust boats 5 are open, and each boat) 3
, 4.5 are opened and closed by the intake valves 6, 7 and the exhaust valve 8Kj, respectively.

One of the two intake boats has a large cross-sectional area between the intake hoard 3 and the other intake boat 4j.

And it has a helical shape. For more details,
The intake boat 3 on the port side consists of an introductory part of the y-direction and a horizontal winding W63 on the outlet side extending continuously therefrom. The other intake boat 4 extends in the form of a vertical VC.

The auxiliary intake boat 4 is twin-branched from the inner peripheral side of the introduction part of the main intake boat 3, and the two intake boats 3.4 are Siamese boats. There are also two intake boats 3.4 Fi, separated by a gap 9 [j, but a gap 9 of Jin.
It is located at the starting position, that is, in the branch part IF 10 d of the main intake hoard 3 and the sub-intake boat 4,
And the combustion chamber 11 from the inflow part 11 to the Siamese port
It is located in the position of 1.

The upper surface 12 of the main intake boat 3 gradually lowers as it goes downstream from the inflow section 11. [On the L partition wall 9, on the wall l113 that constitutes the inner wall surface of the car boat (i10
12, the further downstream the helical-shaped outer peripheral wall surface 14111 bulges, that is, the helical port 3 has a flow path narrower toward the upper phase or downstream. At the exits of boats 3 and 4, both boats open downward into the combustion chamber. Main intake bolt 3 and exhaust boat 5
The cylinder head combustion chamber recess 15 opens into the combustion chamber, and the auxiliary intake boat 4 opens into the combustion chamber, for example, in a squish area 17t'r having a large area, preferably located 1 ift opposite the spark plug 16. 18, 19
, 20ilt are valve stem guides for each boat 3, 4, and 5, respectively. In addition, the inflow section 1 of the Siamese port
1 is connected to the outflow portion 22 of the intake manifold.

Once constructed as described above, the operation of the intake passage according to the first practical example f will be explained.

First, regarding 1M surface construction, a core 30tj for Siamese port creation is shown in Figure 5.

Main intake boat creation part 31. The part 32 for making the sub-intake port is formed integrally with the other, so that it can be used as a prerequisite, and there is no need to use separate core tubes. Therefore, manufacturing accuracy is improved, and fluctuations in performance in mass-produced engines are suppressed. It will be done. Furthermore, by taking this structure, the dual baud) tl is significantly more compact than the conventional independent two baud ff.

Regarding the flow in the intake passage, in the low-to-medium speed range, the intake air flowing from the intake manifold 21 into the Iamy's boat inside the cylinder head is as follows.

The main intake boat 3 has a larger cross-sectional area than the sub-intake boat 41.The air-fuel mixture that has flowed into the main intake boat 3, which is a helical boat, tends to flow more toward the main intake boat 3, which has a larger cross-sectional area.
As the flow path gradually narrows due to the introduction error, the speed increases, and since the upper surface gradually lowers, a downward force is applied, and the flow flows into the spiral portion 3b, where a strong swirling flow is generated. 6 and its valve seat into the combustion chamber, generating a strong vortex flow within the combustion chamber. This stabilizes combustion.

The lean limit is improved and fuel efficiency is promoted.

On the other hand, at high speeds, the current of the air-fuel mixture flowing through the Siamese boat increases, but the flow resistance due to the helical shape of the main intake boat 3 gradually increases, and the flow rate flows to the auxiliary intake boat 4 of the straight boat, where the resistance increases less. The ratio increases, ensuring charging efficiency and maintaining bird output performance.

Figure m3 shows an intake passage according to a second embodiment of the present invention. In the non-embodiments, the intake passage described in the first embodiment is applied as is.

The structure of the intake manifold connected to the inlet side of the Siamese is unique. In FIG. 3, the inlet 11 to the Siamese boat has one outlet n of the intake manifold 21.
is connected. Upper surface 23 of intake manifold outlet n. Lower surface 24. The raised I surface 25F'i, which is connected to the helical outer circumferential side wall (3) of the Siamese boat among the machining sides, smoothly connects between the upper and lower [1]] of the Siamese boat inlet 11 and the outer circumferential side wall. However, among the side surfaces of the intake manifold outflow section 4, the helical inner wall surface 26 of the Siamese port is desirably formed with a bulging portion 27t gradually extending downwardly toward the opposing wall surface 25. Stage 2 at the boundary between 21 and cylinder head 1
8 pieces are formed.

In the second implementation m+, as configured in this way.

The intake air flowing from the intake manifold 21 into the Iamy's boat in the cylinder head is directed toward the main intake boat 3 side through the bulge 27VC on the inner circumferential wall surface of the intake manifold outflow section 22, forming a helical shape. Perimeter @r(
Therefore, the vortex flow is further strengthened in the low-medium speed range by the presence of the turbulent TRS bulge 27 in the combustion chamber, which further improves the lean limit and promotes fuel efficiency. Although the flow resistance of the helical boat 3 increases in the high speed range, the auxiliary intake boat 4 provides high volumetric efficiency and high output, as in the first embodiment.

FIG. 4 shows an intake passage according to a third practical example of the present invention. This embodiment differs from the second actual example in the intake-oriented structure of the flow from the intake manifold to the Siamese boat. In FIG. 4, the outlet 22 of the intake manifold 21
The central axis @ feather is the central axis s of the Siamese boat inflow section 11! 34, it is directed toward the outer periphery @ surface side of the helical boat 3, and the 34Fi intake manifold 21 and the cylinder head 1 are bent and intersected with each other at the boundary portion of the central axis 33. With this structure, the intake manifold 21
The intake air flowing from the Siamese boat inlet 11 is a helical boat. It is directed to flow strongly into the main intake boat 3@. This promotes the generation of a barrel flow within the combustion chamber in the medium speed range. Other configuration 1 effects tjgl and the second embodiment are the same.

The corresponding parts FC are designated by the same reference numerals as those in FIGS.

As described above, when using the intake passage of the internal combustion engine according to the present invention, the advantageous effect can be obtained.

First of all, in the dual intake system, the internal combustion engine is installed in the cylinder head, which improves the special design of the boat arrangement in the combustion chamber.

It is possible to suppress the exaggeration of sexual bonds in the Okiya engine.

Therefore, precise control to increase the fuel-air ratio limit by 1 lil VC is possible.

It can contribute to lower fuel consumption by improving the lean limit.

In addition, the number of partition walls is reduced compared to the Siamese-style two-independent boat, and the inner wall area of the boat is reduced, so there is one less fuel droplet on the wall, and there is no un-hydrocarbon content. Reducing and improving drivability can help you sleep better.

Also, my Siamese friend, 11! Compared to an I-stand dual port, the space occupied by the single-taper jacket wall on the upper surface of the combustion chamber wall is much deeper, and the space between the combustion chamber wall and the combustion chamber wall is better, improving the knock limit and contributing to lower fuel consumption.

Furthermore, by configuring the intake manifold to be oriented toward the helical port inflow, it is possible to enhance the intake control effect of the helical port, especially at low speeds and low loads, expand the combustion stability flammable range, especially the lean range, and improve fuel efficiency. can.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an intake passage of an internal combustion engine according to the present invention. FIG. 2 is a cross-sectional view of an intake passage of an internal combustion engine according to a first embodiment of the present invention. FIG. 3 is a cross-sectional view of an intake passage of an internal combustion engine according to a second practical example of the present invention. #! FIG. 4 is a cross-sectional view of an intake passage of an internal combustion engine according to a third practical example of the present invention. gS is a perspective view showing an example of a core tube that can be used for the construction of the Siamese boat part of the intake passage of the internal combustion engine of the present invention. It is. l...Cylinder head. 2.--Cylinder bore. 3.--Main intake boat. Lyrics/ss introduction. 3b...Enthusiasm/Wirl part. 4.--Sub-intake boat. 5 @1111+1 exhaust port. 6.7 fist...intake valve. 8...Exhaust valve. 9...Fist bulkhead. 10@... Branch. 11 @...Punishment for influx of fist Iamy's boat. 12... i1 on the main intake boat]. 13... Main intake boat inner peripheral wall surface. 14...Main intake port outer periphery II surface. 15...Fist/combustion chamber recess. 16...Spark plug. 17- @ Squish area. 21...9 intake manifold. 22nd issue...Intake manifold outflow part. 27...bulge S. Attack...Dan. Sono...Nakako.

Claims (1)

[Scope of Claims] (1) In the intake passage of an internal combustion engine having a main intake boat consisting of a helical boat and a sub-intake boat consisting of a straight boat, #tJ Bishop main intake boat II intake boat is connected to the branch part of both. An intake passage for an internal combustion engine, characterized in that the intake passage of an internal combustion engine is configured in an Iamize method in which the Iamize boat is located inside the cylinder head, and the outflow section of the intake manifold is connected to the inflow section of the Iamiz boat marked with #. (2. In the intake passage for an internal combustion engine according to claim 1, the outflow portion of the intake manifold is configured to be oriented toward the inflow of the helical outer circumference 11rC of the main intake boat. (3) In the intake passage for an internal combustion engine according to claim 2, the inflow direction of the intake manifold outlet portion is
Inner periphery 11 of the # distribution helical shape of the intake manifold outlet part
This is done by a protrusion formed on a wall 11 that is continuous with 1. (4) In the intake passage of the internal combustion engine according to claim 2, the inflow direction of the intake manifold outlet part is
This is achieved by directing the entire center axis of the passage of the intake manifold outlet toward the outer periphery 1IIIk surface of the helical shape.