JPS5851409Y2 - Air purifier for internal combustion engines - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an air purifier intended to reduce intake noise of an internal combustion engine.

Traditionally, air purifiers for internal combustion engines have had the function of not only filtering the air taken into the engine, but also a muffler to muffle the intake noise emitted by the engine. ,
In recent years, there has been a growing social demand for pollution issues, especially noise reduction.
Air purifiers are increasingly required to function as silencers.

An example of an air purifier that was devised to have the function of a muffler in addition to the function of a filtration device is the Utility Model Publication No. 38-9.
It is shown in Publication No. 001.

In the case of this known example, the air purifier is provided with a main air introduction pipe and a sub air introduction pipe, and the sub air introduction pipe is closed by a valve during engine idling operation and low load operation, where engine intake noise is a particular problem. The valve is kept closed, and when the engine is running at high speed, which requires a large amount of intake air, the valve is opened to allow air to flow in from the auxiliary air inlet pipe by utilizing the venturi negative pressure of the carburetor.

However, providing the auxiliary air introduction pipe in addition to the main air introduction pipe as in the above-mentioned known example poses a problem in terms of manufacturing costs.

Also, since there is no large negative pressure in the venturi part of the carburetor, the valve in the auxiliary air introduction pipe is opened by the venturi negative pressure.
The negative pressure motor (actuator) for the closing operation must be large and have a large pressure receiving area, which is also a problem from the viewpoint of manufacturing costs.

In view of the above-mentioned problems, an object of the present invention is to provide an air cleaning device equipped with an engine intake noise muffling device that has a simple structure, can be manufactured at low cost, and operates reliably and stably.

Hereinafter, the present invention will be described in detail with reference to the embodiment shown in the drawings. In FIG. 1, 1 is a carburetor and 2 is an intake pipe, which is connected to an engine main body (not shown).

3 is an air purifier body connected to the upper end of the vaporizer 1, which has a swell body 4 inside and an air introduction pipe 5 on the surface.
6 is a negative pressure motor attached to the air introduction pipe 5, and this negative pressure motor 6 is composed of two cup-shaped housing parts made of metal or plastic, as shown in FIG. A hollow housing 6a consisting of 6a-L6a-2, stretched within this housing 6a,
A diaphragm 6c forming a negative pressure chamber 6b between the housing parts 6a-1-, a spring 6d provided in the negative pressure chamber 6b to press the diaphragm 6c, and a rod 6e having one end fixed to the diaphragm 6c. It consists of

The atmospheric pressure chamber 6f formed between the housing part 6a-2 and the diaphragm 6c is connected to the air introduction pipe 5 through the opening 6g.
The rod 6e communicates with the inside of the atmospheric pressure chamber 6f and the opening 6.
gY and extends into the air introduction pipe 5.

As shown in FIG. 1, the negative pressure chamber 6b is always in communication with the intake pipe 2 downstream of the throttle valve through a negative pressure conduit 6h.The other end of the rod 6e of the negative pressure motor 6 is connected to the air introduction pipe 5. It is connected to a flap valve 7 provided in the valve 7 and opens and closes this valve.

As shown in FIGS. 3a and 3b, this valve 7 is attached to a valve plate 7c hinged by a pin 7b to a valve mounting piece 7a fixed to the bottom wall 5a of the air introduction pipe 5 by spot welding or the like. A rod connecting piece 7d is fixed to the upper surface of the valve plate 7c by, for example, spot welding, and the free end of the rod connecting piece 7d is bent to form a hollow bearing 7e.

The bent horizontal lower end of the rod 6e of the negative pressure motor 6 is rotatably connected to the bearing 7e via a resin bushing 7f, as shown in FIG. 2.
An open lower g is formed in the valve plate 7.
Even when the air introduction pipe 5 is closed by c, the opening lower g ensures the amount of intake air required for idling or light load operation of the engine.

To explain the operation of the present invention having the above configuration, when the engine is idling or operating under light load, the negative pressure in the intake pipe 2 is large, so the diaphragm 6c of the negative pressure motor 6 is pressed against the spring 6.
The rod 6e'x is displaced upward against the force d, and as a result, the valve plate 7c is rotated upward around the pin 7b, becoming fully closed. Since the valve plate 7c is set to be open lower, it does not interfere with the operation of one engine.

Further, by the above operation, the passage area of the air introduction pipe 50 is narrowed down to the area of the open lower g, so that the intake noise discharged from the engine to the outside through the air purifier is significantly reduced.

Furthermore, when the engine is operating under light to medium load, the negative pressure in the intake pipe 2 decreases, so the valve 7 in the air introduction pipe 5 becomes intermediately open. In addition, since the passage area is smaller than when the valve 7 is fully open, it is possible to ensure the noise reduction effect.

Furthermore, when the engine is operating under a high load, the negative pressure in the intake pipe 2 becomes close to the atmospheric state, and the valve 7 is fully opened, making it possible to secure the amount of air necessary for the engine.

The above-mentioned changes in the negative pressure of the intake pipe 2 are shown in FIG. 4 along with changes in the passage area of the air introduction pipe 5 (ie, changes in the opening degree of the valve 7).

In the above embodiment, the valve plate 7c of the valve 7 is provided with an opening lower g to ensure the minimum required amount of air, but as shown in FIGS. The air introduction pipe 5 has a convex portion 7h on the edge and serves as an air circulation gap to ensure the minimum required amount of air for the engine when the valve plate 7c is fully closed.
It is also possible to leave it between the earthen wall and the earthen wall.

As described in detail above, the present invention has a negative pressure motor 6 having a negative pressure chamber 6bY communicating with the intake pipe 2 downstream of the throttle valve, and the air introduction pipe 5 of the air purifier even when the engine is in the maximum intake pipe negative pressure state. Since it has a valve 7 that can secure the minimum passage cross-sectional area, it is possible to secure the amount of air required by the engine under any engine operating condition, and it also greatly reduces the intake noise emitted from the engine through the air purifier. can be reduced.

In addition, in the present invention, the conventional air purifier main body is used with almost no design changes, and a valve 7 is rotatably attached to the air introduction pipe 5 of the air purifier, and this is driven by a diaphragm type negative pressure motor 5. This has the advantages of simple structure, low manufacturing cost, and reliable and stable operation.

[Brief explanation of drawings]

Figure 1 is a schematic sectional view of the air purifier according to the present invention, Figure 2
The figures are an enlarged sectional view taken along the line ■-■ in Figure 1, Figure 3a,
b is a detailed enlarged top view and side view of the valve in FIGS. 1 and 2, FIG. 4 is a characteristic diagram for explaining the present invention, and FIGS. 5a and 9b are modified examples of the valve. FIG. 2 is an enlarged top view and a side view of the same. 3... Air purifier main body, 5... Bent air introduction pipe,
6... Negative pressure motor, 7c... Valve plate, 6e... Lot I... Pal 7g...
...Opening, 7h...Protrusion.

Claims (3)

[Scope of utility model registration request] (1) An air purifier for an internal combustion engine, comprising a pulp hinged to open and close in the air inlet pipe of the purifier, and a diaphragm connected to the pulp by a rond, downstream of the throttle valve of the engine. and a negative pressure motor that performs the pulp opening and closing operations in response to changes in the negative pressure on the side, and the negative pressure motor is in the pulp fully closed state when the negative pressure becomes greater than a predetermined value. An air purifier characterized in that the pulp is structured to ensure a minimum amount of intake air required for engine operation even when the pulp is in a fully closed state. (2) The air purifier according to claim 1, which is a registered utility model, characterized in that an opening is formed in the valve plate constituting the pulp to ensure a minimum required amount of intake air. (3) A protrusion is provided on the free end of the valve plate constituting the pulp, and when the valve plate is in a fully closed state, the protrusion creates an air circulation gap between the inner surface of the air introduction pipe and the valve plate. The air purifier according to claim 1, wherein the air purifier is characterized in that the air purifier is configured such that the air purifier remains intact.