JPH0322518Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to an intake system suitable mainly for high-speed engines for passenger cars.

[Conventional technology]

Conventionally, it has been known to install a butterfly valve in an intake passage in order to control the output of a multi-cylinder engine (for example, Japanese Patent Laid-Open No. 110765/1983). However, butterfly valves have a problem in that the valve stem passes through the center of the intake passage, which increases intake resistance.In order to improve this problem, it is also known to install the valve stem close to the wall of the intake passage.
(For example, Japanese Patent Application Laid-Open No. 57-108409) However, the latter odor is caused by the fact that the valve plate is configured asymmetrically with respect to the valve shaft, so the valve shaft receives biasing force due to the action of negative intake pressure, causing the valve shaft to rotate. Therefore, if the opening changes unexpectedly due to changes in intake negative pressure, and the rotational resistance is increased to avoid this change,
A new problem arises that requires a large operating force for normal opening/closing operations.

[Means to solve the problem]

This invention aims to solve the above-mentioned problems, and includes a valve shaft provided in at least two intake passages connected to the combustion chamber close to the wall of the intake passage, and a valve shaft provided on one side of the valve shaft. A pair of control valves each consisting of a supported asymmetrical valve plate, one of the control valves opens in the direction of the airflow, and the other control valve opens in the direction opposite to the airflow. It is distinctive in that it is structured as follows.

〔Example〕

Hereinafter, this invention will be explained with reference to the illustrated embodiment. In FIG. 5 is an intake passage connected to the combustion chamber 1 via an intake valve 6; an intake pipe 7;
It is formed in series through an air intake distribution box 8 and one atmospheric pipe 9, and the other end communicates with the atmosphere. A throttle valve 10 is installed in the atmospheric pipe 9 and is manually operated to control the engine output. 11 is an electromagnetically actuated fuel injection valve, and 12 is a known valve mechanism for opening and closing the intake valve 6.

To explain the engine in more detail, as shown in FIG. 1, the combustion chamber 1 is provided with two intake valves 6 and two intake valves 6A, forming a so-called multi-valve engine. A first intake passage 5a for low speed or low output is connected to the combustion chamber 1 through one of the two intake valves 6, and a second intake passage 5b for high speed or high output is connected through the other of the intake valves 6. ing. The second intake passage 5b is provided with a control valve 15 that closes at low speeds or low outputs depending on the speed or output of the engine.

As shown in FIG. 3, the second intake passage 5b has a substantially rectangular cross section with large curved corners, and a valve shaft 16 extending vertically on the wall thereof.
is rotatably supported, and the valve shaft 16 has a valve plate 17 extending toward the second intake passage 5b on one side.
is supported asymmetrically. The valve plates 17 provided in each of the second intake passages 5b of the adjacent cylinders are attached so that one valve plate opens in the direction of the air flow, and the other valve plate opens in the direction opposite to the air flow.

One end of the valve shaft 16 protrudes from the outer surface of the intake pipe 7, and is connected to the diaphragm device 21 via an arm 18 attached thereto and a rod 19 connecting each arm 18.

Therefore, each of the control valves 15 is provided with one that opens in the direction of the cylinder and another that opens in the direction opposite to the airflow. and are connected to each other so that biasing forces acting on the control valve 15 cancel each other out.

The inside of the diaphragm device 21 is divided into a pressure chamber 23 and an atmospheric chamber 24 separated by a bullet membrane 22, and the pressure chamber 23 is connected to the exhaust pipe 26 of the engine via a passage 25.
The atmospheric chamber 24 is open to the atmosphere. 27 is a return spring.

Next, the operation of this embodiment will be explained. First, when the engine is operating at low speed or low load, the pressure of the exhaust gas is low, so the control valve 15 is closed by the return spring 27, and the total amount of air metered by the throttle valve 10 is is taken into the combustion chamber 1 through the first intake passage 5a for low output. That is, each control valve 15 is completely closed, completely blocking the intake air flow to the second intake passage 5b for high speed or high output, and directing the intake air to the first intake passage for low speed or low output. It reaches the combustion chamber 1 only through 5a. That is, the intake air flows through the first intake passage 5.
Since the air flows through a relatively small passage area of only a, a high intake flow rate is obtained, and large turbulence is generated in the combustion chamber, resulting in efficient combustion and good acceleration characteristics.

When the throttle valve 10 is greatly opened to a predetermined opening degree in order to increase the output of the engine, the exhaust pressure increases as the intake air amount increases, and the elastic membrane 22 returns to the spring 27.
The control valve 15 is opened by moving forward against the pressure. The opening degree of the control valve 15 is determined by the balance between the exhaust pressure and the return spring 27, but in practice it is operated at a fully open position and a fully closed position, and functions as a so-called on-off valve.

When the control valve 15 opens, a larger amount of intake air is supplied to the combustion chamber 1 through the second intake passage 5b for high speed or high output, and a large output is obtained. is provided along the vertical wall surface of the second intake passage 5b so that half of the surface is embedded, and does not provide a large resistance to the flow of intake air.

On the other hand, the valve plate 17 is asymmetrical with respect to the valve shaft, but each control valve 15 is a pair of one that opens in the direction of the airflow and one that opens in the direction opposite to the airflow. , the biasing forces acting on it cancel each other out.

[Effect of idea]

As described above, in this invention, the control valve 15 is composed of a valve stem provided close to the wall surface of the intake passage and an asymmetrical valve plate supported on one side by the valve stem. Compared to conventional butterfly valves in which the valve passes through the center of the intake passage, intake resistance can be reduced, making it possible to improve engine performance. In addition, control valve 1
Although the control valve 5 is constructed with an asymmetric valve plate, the control valve 15 has two valve plates, one that opens in the direction of the airflow and one that opens in the direction opposite to the airflow. Since the control valve 15 is configured as such, the effects of the intake air flow are canceled out and eliminated, and there is an effect that a large actuation force is not required to open and close the control valve 15.

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is a partially cutaway plan view of the engine, FIG. 2 is a sectional view thereof, and FIG. 3 is a sectional view thereof. 5a...first intake passage, 5b...second intake passage, 8...intake distribution box, 10...throttle valve, 15...
...Control valve, 16...Valve stem, 17...Valve plate, 21...
...Diaphragm device, 22...Blast membrane, 23...Pressure chamber, 24...Atmospheric chamber, 27...Return spring.

Claims (1)

[Claims for Utility Model Registration] (1) A valve shaft provided in at least two intake passages connected to the combustion chamber close to the wall of the intake passage, and an asymmetric valve shaft supported on one side by the valve shaft. In a control valve that is provided with a pair of control valves consisting of a shaped valve plate, one control valve is configured so that the valve plate opens in the direction of the airflow, and the other control valve opens in the direction opposite to the airflow. Intake system for multi-cylinder engines. (2) The two intake passages are composed of a plurality of intake passages that are connected to a common combustion chamber and have at least a first intake passage for low speed or low output and a second intake passage for high speed or high output. The second intake passage is provided with a control valve that closes at low speed or low output depending on the speed or output of the engine, and the pair of said two control valves are control valves provided in the second intake passage. An intake system for a multi-cylinder engine according to claim 1. (3) The intake system for a multi-cylinder engine according to claim 1, wherein the pair of control valves are of a negative pressure opening/closing type that opens and closes using intake negative pressure as an operating source. (4) The intake system for a multi-cylinder engine according to claim 1, wherein the inner wall of the intake passage that shares the two pairs of control valves has a substantially rectangular cross section.