JPS58148228A - Intake device of internal-combustion engine - Google Patents

Abstract

PURPOSE:To easily generate and promote a swirl in a cylinder, by arranging a device such that intake air from a low load intake passage is moved turning in the peripheral direction of an intake port at a low load. CONSTITUTION:At a low load when only a primary side passage 3 of a carburetor 2 is used, a mixture supplied from the passage 3 flows down into a low load mixture distributive chamber 10 via a throttle valve 5 and cylinder 8. The mixture flows turning in the peripheral direction of intake ports 22 into a cylinder combustion chamber 21 from an intake port 26 via small contoured low load intake passages 25, 24 and from ventilating ports 23 along guide grooves 18 formed to internal walls of the ports 22.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake system for an internal combustion engine that is divided into two passages: a low-load intake passage and a high-load intake passage.

2. Description of the Related Art Conventionally, an intake system in which two intake passages, one for low load and one for high load, are independently opened into a combustion chamber of an engine, a so-called multiple intake system, is generally well known. This dual intake system uses only the small-diameter, low-load intake passage when the engine is operating at low speeds and low loads, increasing the flow rate of the air-fuel mixture and vaporizing the fuel.
In addition to promoting atomization, combustion efficiency is improved by causing intake air to flow into the cylinder from a tangential direction to generate or promote swirl within the cylinder. In addition, during high loads, air-fuel mixture is also supplied from the high-load intake passage to improve output.

However, in the conventionally proposed dual intake system, the intake passage connecting the throttle valve of the carburetor and the air-fuel mixture intake port, which opens into the cylinder combustion chamber and is opened and closed by the intake valve, runs almost the entire length of the low-load intake passage. In many cases, the intake passage is separated into two passages: a high-load intake passage and a high-load intake passage. Therefore, as disclosed in Japanese Patent Application Laid-Open No. 54-76718, ``Intake System J for 4-stroke Engines,'' a low-load intake passage leading to the intake port of the cylinder head
No. 4-76718 discloses that configuring the ventilation passage of the communication passage and the ventilation port opening to the intake port so as to generate a swirl of the intake air flowing into the cylinder combustion chamber is especially necessary in the case of a multi-cylinder engine. There was a problem that there was less freedom in layout and it was more complicated to manufacture.

In addition, as disclosed in JP-A-54-52220 ``Engine Intake Passage Device'', a low-load intake passage (in JP-A-111i4-52220, one way is to lead to primary suction; intake passage for use and intake passage for high load (
In Japanese Patent Application Laid-Open No. 54-52220, turning the upstream and downstream sides of the secondary intake passage (secondary intake passage) 90 degrees to each other means that engine cooling water for heating the intake air is generally used in modern engines. In the intake manifold, where an exhaust gas passage or an exhaust gas recirculation passage is provided as a countermeasure against exhaust gas, it is difficult to layout the intake manifold due to the manufacturing process due to the casting process. It is necessary to have a partition wall between the intake passage and the high-load intake passage, and the manufacturing process is unavoidably complicated.

Therefore, the present invention provides a vent position that opens from the low-load intake passage to the intake port of the cylinder head near the entrance of the intake boat, and also allows the intake air from the low-load intake passage to swirl in the circumferential direction of the intake port. The low-load intake passage is arranged in such a manner that the intake port of the cylinder head is arranged so that the intake air is directed in a direction that coincides with the inner circumferential component of the intake air applied to the low-load intake passage. By forming the whitening component into a rectangular shape, it is possible to easily generate, promote, and strengthen swirl within the V-Syder, and with good productivity.

The present invention will be explained below based on the drawings.

1 and 2 are diagrams showing an embodiment of the present invention. This is an example applied to an intake system for a four-cylinder internal combustion engine. First, the configuration will be explained. The cylinder body 7 has an intake boat 22 formed in a circular shape, and its upstream side is connected to the sub-intake manifold 14 and the main intake manifold 12. The downstream side opens into a combustion chamber 21 formed by a cylinder body 20 and a cylinder head 17 via an intake valve 19 . Further, a downdraft type carburetor 2 consisting of a primary passage 8 and a secondary passage 4 is connected to the upstream side of the main intake manifold 12 via an insulator 7, and an air cleaner l is further connected to the carburetor 2. ing.

The main intake manifold 12 and the sub-intake manifold 14 are
A partition wall 18 formed in the main intake manifold 12 is connected to the downstream end of the partition wall 13, and is divided into two parts by a partition wall 15 formed in the sub-intake manifold 14. A large-diameter high-load intake passage 29.28 is defined. A cylindrical tube 8 is attached to the downstream side of the throttle valve 5 in the primary passage 8 of the carburetor 2, and extends downward to connect to the low-load mixture distribution chamber 10. The load air-fuel mixture distribution chamber IO has the intake port 2 of the low load intake passage 24,25.
6 is open.

Further, a high-load mixture distribution chamber 9 is provided downstream of the throttle valve 6 in the secondary passage 4 of the carburetor 2, and the intake ports of the high-load intake passages 28 and 29 are open. At the same time, the high-load mixture distribution chamber 9 and the low-load mixture distribution chamber 10 are arranged so that the mixture from the primary side passage 8 of the carburetor 2 can also be supplied to the high-load intake passages 28 and 29. are connected to each other through a communication gap 11. Furthermore, a carburetor 2 is installed in the high-load intake passage 29.
Apart from the throttle valve 5.6, an auxiliary throttle valve 16 is provided, and its opening/closing can be controlled by interlocking with the throttle valve 5 of the carburetor 2 using a link mechanism using known technology, or by controlling the negative pressure in the intake road. It is controlled by diaphragm operation.

The small-diameter low-load intake passages 25.24 and the large-diameter high-load intake passages 29.28 each communicate with the intake boat 22 of the cylinder head 17 at their downstream sides, and the opening of the low-load intake passage 24 The vent hole 28 is displaced to one side from the central axis of the intake boat 22 and is provided approximately at the entrance of the intake boat 22. Furthermore, the intake boat 22 is formed in a helical shape, and a spiral intake guide groove 18 is formed on the inner wall from the outer peripheral side of the center axis, and the upstream side of the guide groove 18 is connected to the vent hole. 28
The downstream side thereof extends to the vicinity of the air-fuel mixture intake port 22b, which is opened and closed by the intake valve 19.

Next, the effect will be explained. In the engine equipped with the dual intake system, during low load when only the primary passage 8 of the carburetor 2 is used, the air-fuel mixture with atomized fuel supplied from the primary passage 8 is throttled. 5. The cylinder 8 is flowed down into the air-fuel mixture distribution chamber 10 for light and low load use.

Then, the air-fuel mixture flows down at a high flow rate from the suction port 26 that smoothly opens into the distribution chamber IO to the small-diameter low-load intake passage 25.24, and vaporization and atomization of the fuel are promoted. The air is drawn into the intake boat 22 in a well-distributed manner from each cylinder. At this time, the air-fuel mixture swirls in the circumferential direction of the helical intake boat 22 from the air vent 28 of the cargo intake passage round along the guide groove 18 formed on the inner wall of the helical intake boat 22. A strong swirl is generated in the cylinder combustion chamber 21 together with the intake boat 22, thereby increasing combustion efficiency.

At medium load, when only the primary passage 8 of the carburetor 2 is used and the auxiliary throttle valve 16 in the high-load intake passage 29 begins to open, atomized fuel is supplied from the primary passage 8. The air-fuel mixture is passed through the small-diameter low-load intake passage 25.
24, from the low-load mixture distribution chamber 10 through the communication gap 11, and from the high-load mixture distribution chamber 9 to the auxiliary throttle valve 16.
Large-diameter high-load intake passages 29 and 2 provided with
8, a relatively lean air-fuel mixture also flows down. The relatively rich air-fuel mixture flowing down from the vent 28 of the low-load intake passage 24 swirls in the circumferential direction of the intake boat 22 along the guide groove 18 and flows down from the high-load intake passage 28, forming a helical shape. A strong swirl is generated in the cylinder combustion chamber 21 together with the air-fuel mixture having a circumferential component provided by the intake boat 22. Primary side passages 8 and 2 of the carburetor 2
During high load when the next passage 4 is used, the auxiliary throttle valve 16 opens, and the air-fuel mixture is also supplied from the large-diameter high-load intake passage 29, 28 to the combustion chamber 1 through the intake boat 22. We are trying to improve the output.

Other embodiments are shown in FIGS. 8-4. This embodiment differs from the embodiment shown in FIGS.
The positions of the vents 2t and 2f and the guide grooves and grooves are different. In other words, although the vent ports 2 and 2Ft are located near the inlet of the intake boat 2t121 of the cylinder head 1τ, they are provided in the sub-intake manifold 1i, and are located in the guide groove 18 at the intake boat 22° and 2p.
A part of the upstream side of the sub-intake manifold 14'O is also formed on the downstream side. In addition, in FIG. 4, the vent 2FK and the guide groove 18° in one cylinder are provided displaced to the same side from the center axis of the intake boat 21 as in the above-mentioned actual problem example, but they are provided in a different cylinder. Ventilation port 2 Air intake port 2i'o Inner wall formed in a hexagonal shape Displaced to the side opposite to the outer circumferential side, and guide groove ttN Intake port 2 is moving to. Both the helical intake boat 22', the guide groove ts' formed on the inner wall of the boat 22', and the guide groove ts' have a stronger helical shape than the embodiment shown in FIG.

The effect is almost the same as that of the embodiment shown in Figs. 1 and 2, but the circumferential component of the swirl of the air-fuel mixture flowing down from the low-load intake passage z4', 24''Z>- in the intake boat 21.2g. Furthermore, although not shown in the figures in the other embodiment, the hot water passage for heating the intake air by engine cooling water is the low-load intake passage 25.2+"1. is 26.24'
) If parallel, sub-intake manifold 14'$? This embodiment also has the effect that it is easier to arrange each passage in the cylinder head 17' than in the previous embodiment.

Further, in the embodiments shown in FIGS. 1 to 4, the air-fuel mixture from the low-load intake passage in the intake boat is guided by a groove, but it is also possible to use a guide wall instead.

As explained above, according to this invention, the configuration is
In an internal combustion engine equipped with a dual intake system, an opening position for supplying intake air from the low-load intake passage to the cylinder is provided near the inlet of the intake boat in the cylinder head, and the intake air from the low-load intake passage is placed in the intake boat of the cylinder head. Since the low-load intake passage is arranged so as to swirl in the circumferential direction, it is possible to generate or promote the swirl of intake air in the cylinder combustion chamber, which is the original function of the dual intake system, and improve combustion efficiency. can be done. Furthermore, since the present invention can be applied with almost no modification to the cylinder head commonly used in the past, it is possible to easily allocate each passage in the multiple intake system and improve productivity.

Each of the embodiments has the following effects in addition to the above-mentioned common effects. Since the structure is such that the intake air from the low-load intake passage circulates circumferentially at the intake boat of the cylinder head, the opening position and direction for supplying intake air from the low-load intake passage to the intake boat can be freely arranged. Therefore, the swirl of the intake air in the cylinder combustion chamber can be easily controlled, and the shape of the intake boat can be formed relatively straight to match the high speed and high load of the engine. Furthermore, while the intake air drift caused by the helical intake boat is a relatively large-scale turbulence, the intake air from the low-load intake passage, especially the intake air flow guided by the guide groove or guide wall in the intake boat, is a disturbance on a relatively large scale. Since this becomes a small-scale turbulence, the air-fuel mixture flows well within the combustion chamber and combustion can be improved.

[Brief explanation of the drawing]

Fig. 1 is an explanatory cross-sectional view showing one embodiment of the present invention, Fig. 2 is an explanatory cross-sectional view of the main part seen from above in Fig. 1, and Fig. 88 is an explanatory cross-sectional view showing another embodiment of the present invention. , FIG. 4 is a cross-sectional explanatory diagram of the main parts seen from above of FIG. 8. 1... Air cleaner 2... Carburetor 8... 1
Next side passage 4...Secondary side passage 5.6...Carburizer throttle valve 7...Insulator 8...Cylinder
9...High-load mixture distribution chamber 10...Low-load mixture distribution chamber 11...Connection story 12...Main intake manifold 18.15...Partition wall 14.14'...
Sub-intake manifold 16... Auxiliary valve 17, 17
'...Cylinder head xs, tg', tf? ...Guide groove 19...Intake valve 20...Cylinder 21...Combustion chamber 2s, 2g, 2t?
・Vent port 24.2a', 24τ25...Low load intake passage 28.28°, 29...High load intake passage special
Applicant: Aichi Machine Industry Co., Ltd. 132- Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] (1) It has a low-load intake passage and a high-load intake passage,
In an internal combustion engine, intake air is supplied to the cylinder from the low-load intake passage when the engine is under low load, and from the low-load and high-load intake passages when the engine is under high load.In an internal combustion engine, intake air is supplied from the low-load intake passage to the cylinder. The opening position is provided near the inlet of the intake port of the cylinder head, and the low-load intake passage is arranged so that the intake from the low-load intake passage turns in the local direction of the g-air port. intake system for internal combustion engines. M(2) The internal combustion engine according to claim (1), wherein the opening position of the low-load intake passage in the vicinity of the intake port inlet of the cylinder head is displaced to one side with respect to the central axis of the intake port. Intake device. (8) Claims (1) or (2) include providing an intake guide groove or a guide wall on the inner wall of the intake port of the cylinder head in the direction in which the intake air from the low-load intake passage swirls. ＠Air device of internal combustion engine. (4) ¥! The intake port of the J-da head is formed in a helical shape, and the circumferential component of the intake air given to the helical intake port is configured to match the circumferential component of the intake air from the low-load intake passage. An intake system for an internal combustion engine according to claim (1), (2), or (8).