JPS5840299Y2 - Internal combustion engine air cleaner - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an air cleaner for an internal combustion engine.

Generally, in internal combustion engines, if outside air is drawn into the engine, the pistons and cylinders will wear out due to the dust contained in the air, so it must be cleaned with an air cleaner before being supplied.

In addition, a long intake pipe has been added to reduce intake noise.

For this reason, the shape of the air cleaner has a large effect on engine performance even within the intake system, and in order to improve internal output of engine performance, it is necessary to increase the filling efficiency in areas that are proportional to the volumetric efficiency of intake air. It is.

However, the volumetric efficiency of the intake air taken in by the air cleaner is approximately proportional to the displacement volume of the engine, so unless intake noise is ignored and the shape of the intake pipe is degraded, or if supercharging is not performed, it will not be improved. It's impossible.

Conventionally, in order to solve this problem, a method has been adopted in which the suction pipe is made long, and instead a small hole is bored in the air cleaner case, and auxiliary air intake is performed through this small hole.

However, with this method, the flow form of the intake air is a pulsating flow (repetition of positive pressure and negative pressure) commensurate with the engine's explosion order, so if the inside of the air cleaner case becomes positive pressure, 1 In the next intake stroke, a phenomenon occurs in which a positive pressure wave pushes back the airflow that becomes negative pressure and is inhaled.

As a result, the intake air from J4L flows into the air cleaner, and the improvement in volumetric efficiency Vck is insufficient.

This invention was developed in view of the above-mentioned drawbacks of conventional air cleaners.

This has been improved and removed.

The structure of this invention will be explained below according to an embodiment shown in the drawings.

In FIG. 1, 1 is a suction pipe, and 2 is an upper case 3, which is a lower case that fits into the upper case 2.

The lower case 3 has a conductor W in the center that communicates with the carburetor 4.
5.

6 is a filter element.

Also, the upstream side of the filter element 6 of the lower case 3 (
The required number of small holes 7 for auxiliary intake are drilled in the side of the engine.

A plate spring 8 having a weak elastic force is fixed to the inside of the small hole 1 by a stopper 9, and the small hole 7 is opened and closed as necessary to form a reed valve 10.

The opening and closing of the throttle valve 10 is synchronized with the pulsating flow commensurate with the engine's explosion order.

In other words, if the pressure in chamber a of air cleaner A becomes positive when the intake and exhaust valves (not shown) overlap, a pushback wave is generated in chamber a, and the air in chamber A flows out through the small hole 7. try to.

As if to prevent this, the plate spring 8 of the IJ-do valve 10 is pressed against the lower case 3 by the push-back wave, and the small hole 7 is closed.
Let be closed.

As a result, the air pressure in room a rises slightly due to the push-back wave, and is maintained in this state.

Then, when negative pressure acts on chamber A during the engine's next intake stroke, the pressure difference between the increased pressure and the negative pressure generates an airflow flowing to the engine, and the carburetor 4 generates fuel proportional to this airflow. is supplied to the engine at a predetermined air-fuel ratio.

In this case, the leaf spring 8 constituting the reed valve 10 is bent in the direction of the arrow about the stopper 9 as a fulcrum due to the pressure difference between the negative pressure acting on the chamber a and the atmospheric pressure, thereby opening the small hole 7.

Therefore, auxiliary air flows into chamber a from the small hole 7, and the flow rate of intake air taken into the engine increases.

In addition, as mentioned above, the pressure in chamber A is slightly increased due to the pushback wave during positive pressure, so the flow rate of intake air flowing in the intake pipe increases.

The increased pressure increases the speed, resulting in an increase in the overall intake air flow rate.

The volumetric efficiency of the intake air increases.

FIG. 2 shows volumetric efficiency μV curves with respect to engine speed in the case where the reed valve 10 is provided and in the normal case.

As is clear from this experimental result, the volumetric efficiency μV when the reed valve 10 is provided is far superior to that of the conventional case.

Further, FIG. 3 shows the intake noise level per output, and in this case as well, the intake noise is reduced by providing the reed valve 10.

In summary, the present invention has two or more small holes in the air cleaner case, and the small holes are provided with a leaf spring and a reed valve that is cut from the stopper in the air cleaner case. The internal pressure of the air cleaner case can be increased using waves, and auxiliary air intake can be performed from the small holes without being affected by pulsating waves, which improves the volumetric efficiency of intake air and reduces intake noise per output. This reduces the amount of heat generated and improves various engine performances.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an air cleaner according to the present invention. Figure 2 is a diagram comparing the volumetric efficiency of the intake air of the engine when the present invention is applied and the conventional case, and Figure 3 is a diagram comparing the intake air per output and noise level when the present invention is applied and the conventional case. This is a comparative diagram. 2... Upper case, 3... Lower case, 7... Small hole, 8... Leaf spring, 9...
... Stopper, 10 ... Reed valve.

Claims (1)

[Scope of claim for utility model registration] Two or more small holes are bored in the air cleaner case. An air cleaner for an internal combustion engine, characterized in that the small hole is provided in an air cleaner case serving as a reed valve so as to open inward.