JPS60147527A - Suction device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the engine in its output performance both during a low and a high speed runnings with a compact structure, by arranging the same such that all suction chambers may automatically change their effective volumes from a small to a high level, upon the engine operation changed from a low speed suction passage to a high speed suction passage. CONSTITUTION:While an engine is operated in a low speed, an actuator 15 remain inoperative closing switch valves 9, 10 to interrupt the inlet side of high speed suction passage 5 and also the communication between suction chambers 7, 8. Thus, an air or a fuel-air mixture is withdrawn into the suction chamber 7 through a suction air controlling device 12 and sucked into the combustion chamber 2, passing through a low speed suction passage 6, a branch port 5a, the downstream side of high speed suction passage 5 and a suction port 3. In this way, the engine can provide a desired output performance in its low speed. During the high speed operation of engine, the high speed suction passage 5 is opened to establish communication between suction chambers 7, 8. The air or the fuel-air mixture is thus caused to expand immediately up to the suction chamber 8, and withdrawn into the combustion chamber 2 through the high speed suction passage 5 and the suction port 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention connects a low-speed intake passage and a high-speed intake passage of an internal combustion engine with different intake port lengths in parallel, and selects the two eye airways according to the low-speed and high-speed operating conditions of the engine. The present invention relates to an intake system for an internal combustion engine that is operated in a controlled manner and constantly increases the filling efficiency of the engine due to the intake inertia effect to achieve high output.

Conventionally, as such an intake device, the entrances of the low-speed and high-speed intake passages are opened to a common intake chamber, and the high-speed intake passage is provided with an on-off valve that closes when the engine is running at low speed and opens when the engine is running at high speed. something is known. Such an intake system has the advantage that the intake air amount of the engine can be controlled by one intake air amount control device, but because the low-speed and high-speed intake paths of different lengths are opened into a common intake chamber, The intake chamber will inevitably be formed large.

By the way, the present inventors have found through various test studies that the size of the volume of the intake chamber has the following influence on the operating performance of the engine.

(1) If the volume of the intake chamber exceeds this value, the idle link of the engine may become unstable when the low-speed intake passage is activated.
Engine responsiveness may decrease when sudden acceleration is performed from idle link.

(2) When one intake chamber is commonly used for each cylinder in a multi-cylinder internal combustion engine, if the volume of the intake chamber is too small, the intake pulsations of each cylinder will interfere with each other and the charging efficiency will decrease.
The desired high output performance will no longer be achieved.

(3) When performing resonance supercharging in a multi-cylinder internal combustion engine, the resonance point (engine speed) is determined by the volume of the intake chamber.

Based on these results, in order to always improve the operating performance of the engine, it is desirable to be able to adjust the volume of the intake chamber depending on the high-speed and low-speed operating ranges of the engine. The purpose of the present invention is to provide the above-mentioned intake device that can satisfy the above requirements, and its characteristics are that a low-speed intake passage and a high-speed intake passage of different lengths are connected in parallel to the intake port of an internal combustion engine,
At the entrance of the low-speed intake passage, there is a first valve connected to the intake air amount control device.
A second intake chamber is connected to the inlet of the high-speed intake passage via a first on-off valve, and a second on-off valve is connected to the first on-off valve to connect the first and second intake chambers. They are connected to each other via two on-off valves.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. A cylinder head 1 of an internal combustion engine includes a combustion chamber 2 and a combustion chamber 2.
An intake port 3 that opens to is provided, and this intake port 3 is opened and closed by an intake valve 4.

The intake port 3 has an outer end opened on one side of the cylinder head 1, and a high-speed intake passage 5 is continuously connected to this. A branch port 5a is provided in the middle of the high-speed intake passage 5, and a low-speed intake passage 6 is connected to this branch port 5a.

A first intake chamber 7 is connected to the entrance of the low-speed intake passage 6 so as to be in continuous communication with the first intake chamber 7 . Further, a second intake chamber 8 is connected to the entrance of the high-speed intake passage 5 via a first on-off valve 9 . Further, the first and second intake chambers 7 and 8 are connected to each other via a second on-off valve 10.

Thus, the cross-sectional area of the high-speed intake passage 5 is set larger than that of the low-speed intake passage 6. In addition, the total length of the intake port 3 and the high-speed intake passage 5 is set to a length that can maximize the charging efficiency during high-speed operation due to the intake inertia effect, and the total length of the intake port 3 and the branch port 5a is The total length of the downstream high-speed intake passage 5 and low-speed intake passage 6 is set to the second length L2 that can maximize the charging efficiency during low-speed operation due to the intake inertia effect, and therefore the second length L2 is the first length,
It is larger than.

At the inlet of the first intake chamber 7, primary and secondary throttle valves 11. ．． An intake air amount control device 12 having a diameter of 11□ is installed.

The first and second on-off valves 9 and 10 are supported on a single valve shaft 13 so as to be interlocked with each other, and an actuator 15 is connected to an operating lever 14 fixed to one end of the valve shaft 13. This actuator 15 normally holds both the on-off valves 9 and 10 in the closed position, but when the engine enters a predetermined high-speed operating state, the actuator 15 simultaneously opens both on-off valves 9 and 10. It is now possible to speak.

Next, the operation of this embodiment will be explained. When the engine is operating at low speed, the actuator 15 is in an inactive state and closes the first and second on-off valves 9 and 10, opening the inlet side of the high-speed intake passage 5. At the same time, communication between the first and second intake chambers 7 and 8 is also interrupted. Therefore, the air or mixture sucked into the first intake chamber 7 through the intake air amount control device 12 during the intake stroke of the engine passes through the low-speed intake passage 6, and then passes through the downstream side of the high-speed intake passage 5 from the branch port 5a and is then taken into the intake air. It passes through port 3 and is sucked into combustion chamber 2.

Therefore, as described above, the total length of the low-speed intake passage 6, the high-speed intake passage 5 downstream of the branch port 5a, and the intake port 3 can maximize the charging efficiency due to the intake inertia effect during low-speed operation of the engine. Since the first length is set to be relatively long, the low speed output performance of the engine can be satisfied.

When the engine enters a predetermined high-speed operating state, the actuator 15 operates to open the first and second on-off valves 9 and 10, thereby making the high-speed intake passage 5 conductive and opening the first and second intake chambers 7, Connect between 8. Then, during the intake stroke of the engine, the air or mixture sucked into the first intake chamber 7 by the intake air amount control device 12 immediately spreads to the second intake chamber 8, and then flows through the low-speed intake path 6.
High-speed intake passage 5 with a larger cross-sectional area and lower intake resistance than
The air is drawn into the combustion chamber 2 via the intake port 3.

As mentioned above, the high-speed intake passage 5 is continuously connected to the intake port 3, and the total length of the high-speed intake passage 5 and the intake boat 30 is limited by the intake inertia effect during predetermined high-speed operation of the engine. A relatively short first step that can maximize efficiency.
Since the length Ll is set, the intake inertia effect is effectively exhibited and the high output performance of the engine can be satisfied.

In addition, as described above, during low-speed operation, the second intake chamber 8 is stopped by closing the second on-off valve 10, and only the first intake chamber 7 is communicated with the low-speed intake passage 6, and during high-speed operation, the second on-off valve 1
Since both eye air chambers 7.8 are communicated with the high-speed intake passage 5 by opening the valve at 0, the effective volume of the total intake chamber 7.8 is automatically controlled to be small during low-speed operation and large during high-speed operation. Therefore, when driving at low speeds, it is possible to stabilize the idle link and improve acceleration from the idle link.
During high-speed operation, in the case of a multi-cylinder internal combustion engine, the high-speed intake passage 5 exerts the desired intake inertia effect without being interfered with by the intake pulsation of other cylinders, and the engine output can be improved.

Furthermore, if the total volume of the first and second intake chambers 7 and 8 is set to perform resonance supercharging in the desired high-speed operating range of the engine, the charging efficiency can be further increased and the engine output can be further improved. I can do it.

As described above, according to the present invention, a low-speed intake passage and a high-speed intake passage of different lengths are connected in parallel to the intake port of an internal combustion engine,
At the entrance of the low-speed intake passage, there is a first valve connected to the intake air amount control device.
A second intake chamber is connected to the inlet of the high-speed intake passage via a first on-off valve, and a second on-off valve is connected to the first on-off valve to connect the first and second intake chambers. Since they are connected to each other through the two on-off valves, the effective volume of the total intake chamber is automatically switched from small to large when switching from low-speed intake passage to high-speed intake passage, and as a result, when the low-speed intake passage is activated, It is possible to obtain the desired low-speed output performance of the engine, stabilize the idle link, and improve acceleration from the idle link, and when the high-speed intake passage is activated, the intake air between each cylinder can be improved even in the case of a multi-cylinder engine. The desired high-speed output performance of the engine can be obtained while avoiding pulsation interference. Furthermore, the configuration is simple and can be provided at low cost.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional side view showing one embodiment of the device of the present invention. DESCRIPTION OF SYMBOLS 1... Cylinder head, 2... Combustion chamber, 3... Intake port, 4... Intake valve, 5... High speed intake path, 5a
... Branch port, 6 ... Low speed intake path, 7, 8 ... 1st
．． 2nd intake chamber, 9.10...1st. Second on-off valve, 12
... Intake air flow control device, 15... Actuator patent applicant Honda Motor Co., Ltd. CF de i? "1'

Claims (1)

[Claims] A low-speed intake passage and a high-speed intake passage of different lengths are connected in parallel to an intake boat of an internal combustion engine, and a first intake chamber connected to an intake air amount control device is connected to the entrance of the low-speed intake passage. A second intake chamber is connected to the entrance of the passage via a first on-off valve, and the first and second intake chambers are connected to each other via a second on-off valve that is interlocked with the first on-off valve. Become. Intake system for internal combustion engines.