JPS6073014A - Intake apparatus for multi-intake-valve type engine - Google Patents

Abstract

PURPOSE:To improve combustion performance by strengthening the swirl in intermediate load state by generating the swirl in the same direction to the direction of the swirl supplied from an intake passage for low-load by the intake gas flow supplied from an intake passage for high-load through a communication passage, during the intermediate-load operation of an engine. CONSTITUTION:When an engine is in low-load operation, intake gas is supplied only from an intake passage 7a for low-load by the closing operation of a shutter valve 12, and a swirl Sa is formed. When the engine is in high-load state, the shutter valve 12 opening-operates, and intake gas is supplied from the both of intake passages 7a and 7b for low and high loads. In the range immediately before the opening of the shutter valve 12, namely in case of the intermediate load of the engine where the amount of intake gas is made max. by the intake passage 7a for low-load, a portion of the intake gas is supplied into a combustion chamber 4 from the intake passage 7b for high-load and an auxiliary scroll port 13a through a communication passage 13.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to an intake system for a shutter valve type multi-intake valve engine, which has a low-load intake passage and a high-load intake passage interposed with a silt valve. Regarding this, it is particularly concerned with measures to improve combustibility, which occurs in the unique area of the Shitotsuta valve, that is, during medium loads.

<Prior art> Conventionally, high-load intake passages have been installed in engine combustion chambers, such as low-load intake passages that open and cover the cylinder in a direction substantially tangential to the cylinder, and high-load intake passages that are interposed with a zigzag valve that closes at low loads and opens during high loads. and -C independently, and when the load is low, by supplying intake air only from the low-load intake passage, the intake air is throttled to increase its flow velocity, and the intake air is swirled around the combustion plan. - Generate a T stool (eddy current) and J
Ichinov, Takan, who increases the burning speed and improves combustibility.
B. For the rh-assistant, intake air is also supplied from the high-load intake passage to avoid increasing the passage surface of the intake boat, increasing the intake air filling efficiency and improving the outlet angle. The so-called shutter valve type multi-intake ↑ type intake system is well known. In addition, in such a multi-intake valve type intake system, the intake air is supplied independently into the low angle intake passage and the high load intake passage. The peak value of the intake inertia effect can be obtained in each case, and there is an advantage that the output can be improved in all regions as a whole.

By the way, in such a shutter valve type multi-intake valve type intake system, at medium load, which is the area immediately before the shutter valve hears the intake passage, that is, the maximum flow rate through the low load intake passage, the intake passage resistance increases and the filling There is a problem in that the efficiency decreases and the intake valve acts as a resistance due to the intake inertia effect, making it impossible to fully demonstrate the effect. To solve this problem, conventionally, as shown in Japanese Unexamined Patent Publication No. 57-105534, a communication passage was provided downstream of the shutter valve to communicate the low-load intake passage and the high-load intake passage.
By supplying intake air from the high-load intake passage through the communication passage during medium load, the intake resistance of Jf1 is suppressed and the intake air filling amount during medium load is increased. It has been proposed to increase the intake inertia effect and thereby improve the output.

However, in this proposal, during medium load, intake air is supplied to the combustion chamber from both the low-load intake passage and the high-load intake passage, so the swirl of intake air generated by the low-load intake passage is There is a problem in that the flow is completely canceled out by the intake flow from the high-load intake passage, and combustion performance deteriorates due to the disappearance of this swirl.

(Object of the invention) The object of the present invention is the above-mentioned tF! 'A' was further improved to generate a swirl in the same direction as the stool direction from the low-load intake passage in the intake flow from the high-load intake passage via the communication passage during medium load. 33 at medium load
While suppressing the increase in intake resistance and improving the output direction,
The objective is to effectively strengthen the swirl that occurs at medium load u11 and improve c1 combustibility.

(Structure of the Invention) In order to achieve the above-mentioned [1], the Plr1' determining means of the present invention has the structure of the above proposal. Closes when the load is high and opens when the load is high.
In addition, a communication passage is provided downstream of the shutter valve to communicate the low-load intake passage with the high-load intake passage. In the intake device, the downstream end of the communication path is
The auxiliary swirl boat is opened in the high load intake passage so as to generate swirl in the same direction as the swirl direction generated by the low load intake passage. .

As a result, at the time of medium load just before the shutter valve is activated, intake air is supplied from the auxiliary swirl bow 1~ as well as the low load intake passage, increasing charging efficiency and intake inertia effect, and also from the low load intake passage. The intake swirl flow is reinforced by the intake swirl flow from the auxiliary swirl bows 1 to 1.

(Effects of the Invention) Therefore, according to the present invention, the features of the shutter valve type multi-intake valve type intake system (improvement of combustibility at low load)
3 and all operating ranges (especially in the upper exit direction at high loads), while suppressing the increase in intake resistance during engine medium loads and aiming for the exit direction -1-, the swirl that descends during medium loads is effective. [This strengthens the combustibility of the engine, which improves drivability over the entire operating range of the engine.] 5 There are things that can be done.

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

FIGS. 1 and 2 show an intake system for a multi-intake valve engine according to an embodiment of the present invention, in which a pair of intake bows 1 for low-load and high-load applications are connected to one cylinder. A pair of glue 1
It is applied to the Bevalve type 41 Nikle engine equipped with air pressure 1~.

In the figure, 1 is a cylinder block III on which a cylinder 2 is formed, 3 is a cylinder head connected to two parts of the cylinder tube 1, and L is a cylinder 2 and a cylinder head 3. A combustion chamber 4 is formed on the lower surface.

This combustion chamber 4 has two intake ports 1 to 5a, 5b for low-angle engine use and high-load use open on one side, and a 135th and second two exhaust ports on the other side. 1
-6a and 6b are frontage. The above low load boat 5
A low load intake passage 7a is connected to the high load intake passage 7a, and a high load intake passage 7b is connected to the high load intake boat 5b. Therefore, the low load intake passage 7a and the high load intake passage 7b are connected to Intake port 1 to 5 for low load and high load respectively
It is independently connected to the combustion chamber 4 via a and 5b.

In addition, the low-load intake ports 1 to 5a, which are downstream ends of the low-load intake passage 7a, are formed with openings in the tangential direction of the cylinder 2, and flow into the combustion chamber 4 from the low-load intake passage 7a. Swirl Sa is generated by the intake air flow. On the other hand, the '1st and 24th J+ air boats 6a, (31) are gathered together and connected to the exhaust passage 8. Note that 9 is the connection between each intake boat 5a and bb to the combustion chamber 4. This is an intake well disposed in the section, which opens each intake port 1 to 5a, 5b at a predetermined timing in the intake stroke in synchronization with the engine.Also,
Reference numeral 10 denotes an exhaust valve disposed at the opening of each exhaust boat 6a, 6b to the combustion chamber 4, which opens each exhaust port 1 at a predetermined timing in the II stroke in synchronization with the engine.
- There is a type C that separates 6a and 6b. '11 is combustion chamber 4
This is the ignition plug mounted on J, which is located in the center of the upper part of the vehicle.

Then, in the high load intake passage 71) (L, shutter valve 12 that closes at low engine load and listens at high load).
A-3 is interposed, and low load (low angle 111 river intake due to the closing operation of J series ~ l ivy valve '12) 1η
One force that supplies intake air only from path 7a, high angle '+jj I
For f;'+, intake air is also supplied from the intake passage 7b for J and high angle (Aj) in response to the closing operation of the X/ivy valve 12.

Further, the low-load intake passage 7a and the high-load intake passage 71] are communicated with each other by a communication passage 13 upstream of the seat valve '12. The downstream end of the communication passage 13 (that is, the frontage to the Oi negative Sengawa air passage 711) is
Swirl 3 generated in L low load intake vent D73
The auxiliary swirl ports 1 to 1 are opened to the high-load intake passage 7b so as to generate a swirl sb in the same direction as the direction a.
13a (!-), the fuel 1 is installed in the low-load intake passage 7a upstream of the upstream end (opening to the low-load intake passage 7a) 13b of the communication passage 13. A fuel injection nozzle 14 is provided to supply fuel to the combustion chamber 4 from the high-load intake passage 71 via the low-load intake passage 7a and the communication passage 13.

Next, to explain the effects of the above embodiment, when the engine load is low, the closing operation of the shutter valve 12 is
: By supplying intake air only from the low-load intake passage 7a, the intake air is throttled and its flow velocity is increased, and a swirl Sa is generated by the intake air flowing into the combustion chamber 4 from the low-load intake passage 7a. Both effects increase the combustion rate and improve combustibility. On the other hand, when the engine is under high load, the intake air is supplied from both the low-load and high-load intake passages 7a and 7b by the operation of the shatter valve 120, which increases the intake air flow and improves the output. do. In addition, in this way, the low load intake passage 7a and the high load intake passage 7h are connected to /I't++lL/E/
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■Reprint: [1] The intake inertia J Song will improve the output.

On the other hand, the shutter valve'] own area for 2 hours,
In other words, the low-load intake passage 7a+: 96ij It, '+ in the engine where the intake flow rate is maximum, the intake resistance increases, but part of the intake air flows through the communication passage '13 to the high-load intake. Passage 7b (Auxiliary stool port 1-13a
) is supplied to the combustion chamber 4 from (J, 1), the increase in intake resistance is suppressed, and the intake light efficiency it> and the intake inertia effect are enhanced (4r). You can aim for the direction of exit. Furthermore, during this medium load, in the combustion chamber 4, the intake air for low negative current d)1)) is generated by the path 7a. Swirl 3b in the same direction as the swirl Sa is generated, and the swirl Sa
It is effective (2) because it is strengthened, and it also improves flammability.

Note that the peak value of the above-mentioned intake inertia effect is shifted due to the formation of the communication passage 13, but since the passage area of the communication passage 13 is extremely smaller than the passage area of each intake passage 7a, 7b, the effect is Small, outgoing direction that covers all operating ranges.
There is no problem in terms of

[Brief explanation of the drawing]

The drawings show embodiments of the invention, with FIG. 1 being a schematic cross-sectional view;
FIG. 2 is a longitudinal sectional view of the same. 2...Cylinder, 4...Combustion chamber, 7a...Intake passage for low load, 7b...Intake passage for high load, 12...
Shutter valve, 13...Communication path, 13a...Auxiliary swirl boat, Sa...Swirl generated by the low-load intake passage, sb...Swirl generated by the auxiliary swirl boat.

Claims (1)

[Claims] (1) Open D' in the substantially tangential direction of the cylinder! A low-load intake passage named J' and a high-load intake passage equipped with a Shitotsuta valve that closes at low load and opens at high load are opened into the combustion chamber independently in each nozzle, and the low-load intake passage is inserted into the combustion chamber downstream of the Shitotsuta valve. In an intake system for a multi-intake valve engine that is provided with a communication passage that communicates a high-load intake passage with a high-load intake passage, the 1: origin of the communication passage is connected to the swirl direction generated by the low-load intake passage. An intake system for a multi-intake valve type engine, characterized in that an auxiliary swirl bow is opened in a high-load intake passage so as to generate a swirl in the same direction.