JPS5828511A - Internal combustion engine having combustion chamber with multiple suction ports - Google Patents

Abstract

PURPOSE:To ensure the charging efficiency during a high load operation and to improve the combustion stability during idling by constituting said engine provided with a passage control valve on the secondary suction port so that said passage control valve is closed only when a throttle is fully closed. CONSTITUTION:A transfer control valve 41 is fitted on a negative pressure pipe 37 connecting an actuator 20 and the primary suction port in an engine provided with the primary suction port 3 and the secondary suction port 6 having a passage control valve 9 actuated by the actuator 20 operating in response to the suction negative pressure. The transfer control valve 41 operates in response to the signal S from a transfer switch 45 which senses the fully closed position of a throttle valve 17 of a carburetor 15, and it is constituted so as to bleed the negative pressure pipe 37 to the atmosphere A normally and to connect the negative pressure pipe 37 to the port 3 only when the signal S is received. The actuator 20 is constituted so as to close a sub-throttle valve 9 and to cut off the intake air from the port 6 when the suction negative pressure is applied.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a disc internal combustion engine having a combustion chamber with a plurality of intake valves.

Conventionally, one of the techniques for reducing fuel consumption was to configure the intake port of the combustion chamber as a helical port, which gave a high swirl to the fresh intake air and combusted it. The large intake resistance caused by the helical shape was a problem, reducing charging efficiency and causing deterioration in output and fuel efficiency.

Therefore, in order to compensate for this drawback, this Heri Calport (first
It has also been proposed to provide a second intake, If-) in addition to the intake port) to ensure charging efficiency at high speeds and high loads. As the flow velocity of the fresh intake air decreases, it becomes difficult to generate an effective swirl, leading to deterioration in output and fuel efficiency in this region.

The present invention has been developed to solve the above-mentioned problems, and while ensuring the charging efficiency at high speeds and heavy loads, it also shuts off the secondary intake port at idle (when the throttle is fully closed). The objective is to improve combustion stability during deceleration and idling, improve emissions (especially HC), and improve fuel efficiency during deceleration and idling.

An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, 1 is a cylinder head of a cylinder, and 2 is a combustion chamber. A helical type primary intake spear 3 for generating a one-height swirl opens near the ignition i & 4 of the combustion chamber °2, and an exhaust port 5 opens at a position opposite thereto.

Further, in the vicinity of the primary intake port 3 in the combustion chamber 2, a secondary intake port (eccentric port) 6 is provided which preferably generates a swirl in the same direction as the primary intake air/-) 3. Each 4-) 3, 6.5 has a primary intake valve 7 and a secondary intake valve 8 which are independently actuated by respective cams.
, and an exhaust pulse f (not shown).

The primary intake /-)3 is a helical /-) to obtain a sufficiently high swirl, while the secondary intake /-)6
is the primary intake, so that the intake resistance can be minimized.
It is formed to have a smaller diameter than the jet, and the primary intake port 3
The eccentric I-toe provides a biased flow along the cylinder wall so as to properly bias the generated swirl. Upstream of the secondary intake port 6, there is provided a flow path control/arm loop (auxiliary slot, torque/guru f) 9 that opens in a medium to high load range. This flow path control valve 9 operates according to the engine load or rotation speed.

In the illustrated embodiment, the pulp 9 is controlled to open and close by a negative pressure actuator 20 depending on the engine load. Therefore, the pulp 9 is connected to the actuating rod 25 of the actuator 2o via the link mechanism 23. The actuator 2o has a negative pressure working chamber 31 partitioned by a diaphragm 27 and a chamber 33 open to the atmosphere.
II"i, connected to the diaphragm 27 and interlocked with the diaphragm. The negative pressure working chamber 31 is connected to the intake negative pressure region, for example, upstream of the primary intake port 3 via the pipe 37. Note that 35 is the diaphragm 27 return sgering.

According to the invention, a switching control valve 41 is provided in the negative pressure line 37, preferably in the form of a solenoid valve.

The control valve 41 is, for example, the throttle pulse f17 of the carburetor 15.
It is activated in response to a signal S from the idle switch 45 which senses the fully closed position of the idle switch 45.

The idle switch 45 is, for example, Slo, Torparg 170.
An electrical limit switch that detects the fully closed position may be used.
The changeover switch 45 normally bleeds the negative pressure line 37 to the atmosphere, and only bleeds the negative pressure line 121 when receiving the idle signal S.
37 is connected to the intake negative pressure. acti crystal eta 2oF
Only when negative intake pressure is applied, the sub-throttle valve 9 is closed and the intake air from the secondary intake hole 6 is cut off.

In the second engine having the above-mentioned configuration, when the throttle is fully closed during idling or sudden deceleration, the flow path control paddle f9 is closed as described above. Therefore, the new air-fuel mixture flows between the primary intake and the primary intake. Since the fuel is drawn into the combustion chamber 2 only from the exhaust port 3, a sufficiently large flow velocity is obtained and a high swirl is generated. As a result, stratified combustion is possible especially during idling9, high output and low fuel consumption can be achieved.

On the other hand, at medium-high speeds and medium-high loads, the flow velocity in the primary intake port 3 should be high enough to obtain a sufficiently high swirl. However, since the negative pressure acting on the actuator 20 is bled to the atmosphere by the switching valve 41, the flll side passage/group 9 on the side of the secondary intake mate 6 opens and the new air-fuel mixture to compensate for the shortage is opened. Inhaled.

In this case, although the flow velocity of the primary intake/-) 3 cases decreases slightly and the swirl weakens, the swirl is energized by the drift along the cylinder wall on the secondary intake port 6 side, and as a result, the swirl is sufficiently increased. Swirl is obtained, and good stratified combustion similar to that at idle is possible. Therefore, high output and low fuel consumption can be achieved even at medium-high speeds and medium-high loads.The primary intake port 3 is preferably #'
The secondary intake port 6 has a larger cross section than the secondary intake port 6, but this is because a small diameter does not generate sufficient swirl. This is to minimize the deterioration of drivability when it is in the commonly used range.

As is clear from the above explanation, according to the present invention, two
By installing a flow path control valve in the next intake port that closes only when the throttle is fully closed, it can achieve medium to high speeds.

While ensuring sufficient swirl and charging efficiency in the medium and high load range, it is possible to ensure high swirl and improve combustibility during idling or deceleration.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view of a combustion chamber of an internal combustion engine showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line ■--■ in FIG. 2... Combustion chamber, 4... Ignition function 1.3... Primary intake port, 6... Secondary intake port, 9... Flow path control valve, 15... Carburizer, 17 ... Throttle pulp, 20... Actuation eater, 41... Switching control valve,
45...Idle switch. 1 country 1-111 sea.”

Claims (1)

[Claims] An internal combustion engine having a combustion chamber equipped with a primary intake port in the form of a helical/-) for generating high swirl and a secondary intake date equipped with a flow path control valve operated by an actuator that responds to intake negative pressure. In the engine, the fully closed position of the throttle valve of the carburetor is sensed during the actuator's negative pressure circuit, and the actuator's negative pressure circuit is selectively vented to the atmosphere.
9. An internal combustion engine having a plurality of combustion chambers with intake air/-), characterized in that a switching control valve is provided.