JPS60233314A - Aspiration control device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve the combustion under low load conditions by forming the aspiration system of an engine having two intake valves per cylinder with a separate intake passage for each intake valve and a common intake passage having an open-close valve and an injection valve, which are communicated at respective intake ports. CONSTITUTION:Each cylinder 4 has two intake valves 6a, 6b, and separate intake passages 16a, 16b for each intake valve are disposed on both sides with an intake passage 15 common to respective intake valves occupying the center. The passage 15 has an open-close valve 22 operative at high speeds and an injection valve 21 on the downstream side, which are communicated at the respective intake ports and end of a separator wall 20. Under low load conditions, the open- close valve 22 remains closed, and the intake air is supplied to the respective ports from the outer passages at a high speed along the cylinder wall. The intake air streams collide head-on with each other to generate a strong turbulence, and the intake air merged from both the ports in the common passage gathers in the center of the cylinder together with the injected fuel as a rich mixture, where the ignition takes place by a spark plug.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an intake control system for a multi-intake valve internal combustion engine in which each intake has a pair of intake valves.

Prior art JP-A-57-70914 or JP-A-57-105
No. 534 discloses an intake control device that is provided with a pair of intake valves per cylinder, and is provided with an intake control valve inside the intake passage, and opens and closes the intake control valve according to visual operating conditions. be.

Furthermore, Japanese Patent Laid-Open No. 59-15628 discloses an intake control device in which an intake passage is branched into two corresponding to a pair of intake valves, and a partition wall is formed in each branched intake passage to protrude downward from an upper wall surface. is disclosed.

Furthermore, the present applicant has developed a method that can generate strong turbulence in the combustion chamber during light load operation of the engine while ensuring high charging efficiency during engine high speed and high load operation, and further improve ignition performance and good acceleration operation. In order to secure the
No. 51 (filed on January 13, 1980), proposed an intake passage in which the intake passage was divided into three parts. That is, the intake passage is divided into three by a pair of partition walls extending upstream from the stem guide of each intake valve into a central passage and a pair of side passages formed on both sides of the central passage, which are closed during light engine load operation. An intake control valve for valving is arranged at the upstream end of the central passage, a separation wall extending along the center of the pair of partition walls is formed at the downstream end of the central passage, the downstream end of the central passage is divided into two by the separation wall, and the separation wall This intake control device has a communication port that communicates a central passage and a side passage formed in a partition wall adjacent to the partition wall, and a fuel injection valve is disposed in the central passage between the partition wall and the intake control valve.

Purpose of the Invention The purpose of the present invention is to further improve the intake system of an internal combustion engine described in the previously proposed Japanese Patent Application No. 59-3551, and to improve the output (torque) especially in the low and medium speed range. be.

Structure of the Invention According to the present invention, each cylinder has a pair of intake valves, and the intake passages communicating with these intake valves extend from the stem guide of each intake valve upstream to the surge tank. The air intake control valve is divided into three parts by a partition wall into one central passage and a pair of side passages formed on both sides of the central passage, and an intake control valve that closes during light engine load operation is disposed within the central passage. forming a separation wall extending along the center at the downstream end of the central passage, dividing the downstream end of the central passage into two by the separation wall;
A multi-intake valve type internal combustion engine in which a communication opening is formed in a partition wall adjacent to the partition wall to communicate a central passage and a side passage, and a fuel injection valve is disposed in the central passage between the partition wall and the intake control valve. An intake control device is provided. In this case,
The three-part passage is formed by a central passage and two side passages formed inside the intake port of the cylinder head, and a central passage and two side passages formed inside the intake branch pipes communicating with these passages, respectively. be done. Preferably, the intake control valve is located within the central passage of the intake branch, close to the intake boat of the cylinder head.

Embodiment Referring to FIG. 1 and FIG. 2, 1 is a cylinder block, 2 is a piston that reciprocates within the cylinder block 1,
3 is a cylinder head fixed on the cylinder block 1, 4 is a combustion chamber formed between the piston 2 and the cylinder head 3, 5 is a spark plug arranged in the combustion chamber 4, and 6a is a first
6b is the second intake valve, 7a is the first intake valve 6a
7b is a stem guide of the second intake valve 6b, 8 is an intake port formed in the cylinder head 3, 9 is a stem kite;
indicates an intake branch pipe, lOa indicates a first exhaust valve, IOb indicates a second exhaust valve, 11 indicates an exhaust port, and cylinder head 3
The intake boat 8 and the passage within the intake branch pipe 9 form an intake passage 12. As shown in FIG. 2, both side wall surfaces 13a, 13b of the intake boat 8 have corresponding intake valves 6a,
extending substantially straight in a tangential direction to the peripheral edge of 6b;
Furthermore, both side wall surfaces 13a and 13b are provided with intake valves 6a and 6.
Expand towards b. However, the side wall surfaces 13a and 13b of the intake passage 120 extend substantially parallel to the surge tank 30 in the region of the intake branch pipe 9.

In the intake passage 12, there is a first partition wall 14a extending upstream from the stem guide 7a to the surge tank 30 upstream of the intake branch pipe 9, and a first partition wall 14a extending upstream from the stem guide 7b to the surge tank 30 upstream of the intake branch pipe 9. A second partition wall 14b extending to the tank 30 is formed. Therefore, the interior of the intake passage 12 is defined by the pair of partition walls 14a and +4b.
a central passage 15 formed between central passage 14b; a pair of side passages 16a formed on both sides of central passage 5;
It is divided into three parts, 16b and 16b. These partition walls 14a, 1
4b are the side wall surfaces 13a, 1 of the intake passage 12 (the intake boat 8 and the intake branch pipe 9) over almost their entire length.
31+, respectively. Therefore, side passage 1
6a and 16b have a substantially uniform width (cross-sectional area) over the entire length.

On the other hand, the central passage 15 is connected to the intake valve 6 in the region of the intake boat 8.
a, 6b, whereas the area of the intake branch pipe 9 has a substantially uniform width (cross-sectional area).

At the downstream end of the central illumination passage 15, both intake valves 6a, 6 are provided.
Upstream from between the valve seat openings of b, both partition walls 14a, 1
A separation wall 17 is formed extending along the center of the central passage 4b, and the downstream end of the central passage 15 is divided into two into a pair of branch passages 15a and 15b. This separation wall 1
As shown in FIG. 1, 7 is a valve stem guide 7a,
It extends to a portion slightly beyond 7b.

As shown in FIGS. 1 and 4, the separation wall 17 extends from the upper wall surface of the intake boat 8 to the lower wall surface.

On the other hand, as shown in FIGS. 1 to 4, each partition wall 14a
, 14b extend from the upper wall surface to the lower wall surface of the intake boat 8 and the intake branch pipe 9 in the upstream portion A of the intake boat 8 and all areas A2 of the intake branch pipe 9, and each partition wall 14a, 14b is adjacent to the separation wall 17. The downstream portion B of the intake port 8 extends from the upper wall surface of the intake boat 8 to an intermediate height position of the intake boat 8. Therefore, below the downstream portion B of each partition 14a, 14b, there is a central passage 15, a side passage 16a,
A communication opening 18 is formed that communicates with the opening 16b. 1st
As shown in the drawings and FIG. 2, the upstream end 19 of the communication opening 18 is located upstream of the upstream end 20 of the separation wall 17. A fuel injection valve 21 is disposed on the upper wall surface of the central passage 15 upstream of the upstream end 20 of the separation wall 17.
From there fuel is injected toward the upstream end 20 of the separation wall 17. On the other hand, inside the central passage 15 in the area of the intake branch pipe 9,
An intake control valve 22 in the form of a butterfly valve is inserted in a position close to the intake boat 8 , and this intake control valve 22 is rotatably supported by a valve holder 23 fixed to the intake branch pipe 9 . An arm 24 is fixed to the upper end of the intake control valve 22 .

The intake control valve 22 is opened and closed by a known means (not shown) depending on the engine load or engine speed. That is, the valve is controlled to close during light load operation.

During engine operation, fuel injected from the fuel injection valve 21 is evenly distributed within the branch passages 15a and 15b.

If the engine load is low at this time, the intake control valve 22 closes to close the central passage 15 as described above.

Therefore, at this time, most of the intake air is transferred from the surge tank 30 to the side passages 16a and 16b as shown by arrow P in FIG.
A portion of the intake air flows straight into the combustion chamber 4 from the side passages 16a, 16b as shown by the arrow Q in FIG. 15a, 15b, and then into the combustion chamber 4. Side passage 16a.

The intake air flowing into the combustion chamber 4 from 16b turns in opposite directions while following the peripheral wall of the combustion chamber 4 as shown by arrow P, and collides head-on with each other, generating strong turbulence within the combustion chamber 4. On the other hand, as shown by arrow Q, branch passage 15a
, the intake air flowing into the branch passage 15a
, 15b, and mixes with the injected fuel to form a rich mixture. This rich air-fuel mixture flows into the center of the combustion chamber 4, and thus the area around the spark plug 5 is filled with the rich air-fuel mixture. Therefore, the air-fuel mixture is easily ignited by the spark plug 5, and since strong turbulence is generated in the combustion chamber 4 as described above, the combustion speed is increased. In this way, good ignitability can be ensured even under light loads, and stable combustion can be obtained.

On the other hand, during high-load engine operation, the intake control valve 22 fully opens the central passage 15, so that intake air flows from the surge tank 30 to the central passage 15 and side passages 16a.

It flows into the combustion chamber 4 through 16b. Side passages 16a, 16b, central passage 15 as shown in FIG.
Since the branch passages 15a and 15b extend almost straight, the flow resistance of these passages is small, and the intake air flows smoothly within these passages, so that high filling efficiency can be obtained.

Effects of the Invention When the engine is operated under light load, a rich air-fuel mixture is formed around the spark plug, and strong turbulence is generated within the combustion chamber, ensuring good ignition performance and increasing the combustion speed. It is possible to obtain stable combustion with low fuel consumption. The intake air flows through two relatively long and narrow side passages 16a,
Since the intake air flows into the combustion chamber 4 through the intake air 16b, the torque can be improved in the low and medium rotation range due to the pulsation of the intake air and the inertia effect.

On the other hand, when the engine is operated under high load, the intake air flows almost straight from the surge tank through the intake passage and into the combustion chamber, so the flow resistance to the intake air flow is small, and thus high charging efficiency can be obtained. Moreover, most of the fuel injected from the combustion injection valve is immediately supplied into the combustion chamber without adhering to the inner wall surface of the intake passage, so that good acceleration operation can be ensured.

[Brief explanation of the drawing]

1 is a side sectional view of an internal combustion engine according to the present invention taken along line I-I in FIG. 2, FIG. 2 is a sectional plan view of FIG. 1, and FIG. 3 is a line MM in FIG. FIG. 4 is a cross-sectional view taken along line IV--IV in FIG. 2. 6a, 6b...Intake valve, 7a, 7b...Stem guide, 8...Intake boat, 9...Intake branch pipe, 12...
・Intake passage, 14a, 14b... bulkhead, 15...
Central passage, 16a, 16b... Side passage, 17...
- Separation wall, Work 8... Communication opening, 21... Fuel injection valve, 22... Intake control valve, 30... Surge tank.

Claims (1)

[Scope of Claims] 1. Each cylinder has a pair of intake valves, and a pair of partition walls extends the intake passage communicating with these intake valves from the stem guide of each intake valve upstream to the surge tank. The air intake control valve is divided into one central passage and a pair of side passages formed on both sides thereof, and an intake control valve that closes during light engine load operation is arranged in the central passage. A separation wall extending along the central passageway is formed at the downstream end of the central passageway, the downstream end of the central passageway is divided into two parts by the separation wall, and the central passageway and the side passageway are connected to each other in a partition wall portion adjacent to the separation wall. An intake control device for a multi-intake valve type internal combustion engine, in which an opening is formed and a fuel injection valve is disposed in a central passage between the separation wall and the intake control valve. 2. The three divided passages include a central passage and two side passages formed inside the intake boat of the cylinder head, and a central passage and two side passages formed inside the intake branch pipes communicating with these, respectively. An intake control device according to claim 1, which is formed by: 3. The intake control device according to claim 1, wherein the intake control valve is provided inside the central passage of the intake branch pipe close to the intake port of the cylinder head.