JPS597577Y2 - Air purifier for internal combustion engines - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an air cleaner for an internal combustion engine that suppresses noise caused by vibration transmission by increasing the rigidity of the cap and case.

As shown in FIG. 1, an annular filter body 3 is placed in a space formed by a thin cap 1 and a deep-bottomed case 2.
The cap 1 and the case 2 form the main body of the air purifier.

However, when the above conventional air cleaner is installed in an internal combustion engine, there is a drawback that vibrations from the internal combustion engine are transmitted to the air cleaner and generate noise.

The present inventor investigated the above-mentioned noise sources and found that the vibration of the cap 1 was particularly large, and that the cap 1 accounted for most of the noise sources.

Therefore, the present inventor investigated the cause of the cap 1 becoming a noise source, and as a result, discovered the following.

That is, in the conventional air purifier with the above structure, since the cap 1 is thin and has a shallow bottom, there is a large difference in rigidity between the cap 1 and the case 2, which has a deep bottom. When the rigidity of the cap 1 is low, for example, when vibrations from an internal combustion engine are transmitted to the air purifier, the cap 1, which has low rigidity, vibrates greatly, which increases noise due to vibration transmission from the air purifier.

Therefore, the present invention provides an air purifier for internal combustion engines that can reduce noise when vibrations from the internal combustion engine propagate by making the cap shape more rigid and the case also more rigid. It is something that makes it a priority to do something.

The present invention will be explained below with reference to examples.

In FIGS. 2 to 4, 1 is a metal cap, and 2 is a metal case, which houses an annular filter 3 and a gasket 4 to form the main body of the air purifier. , the depth ratio of case 2 is made close to 1.

Reference numeral 5 denotes a flat part provided at the center of the cap 1, and has four parts 6 on its outer periphery.

A wing nut (not shown) is supported on this plane portion 5.

Reference numeral 7 denotes an annular convex portion, which is provided on the outer periphery of the four portions 6 of the cap 1 and at a portion corresponding to the inner circumferential portion of the filter body 3 so as to protrude outward from the cap 1.

The cap 1 is provided with a flat part 8 that supports the end of the filter body 3, and the flat part 8 and the annular convex part 7 are connected through nine recesses 21 spaced apart from each other.

This concave portion 21 is comprised of a spherical portion 18 and a curved portion 19,20.

Reference numeral 9 denotes nine ribs, which are located between the concave portions 21 and connect the top portion 10 of the convex portion 7 and the flat portion 8.

Reference numeral 11 denotes an outer peripheral side wall of the cap 1, which has a flat part 12 on its inner peripheral part.

This plane part 12 and the plane part 8 are connected by a spherical part 13 so that the vertical cross-sectional shape of the cap 1 as a whole has a bowl shape.

A gasket 14 is attached to the flat portion 12, and is made of a material such as sponge rubber.

Reference numeral 15 denotes a flat part provided on the case 2, on which the end of the filter body 3 is supported and the gasket 4 is attached.

16 is a U-shaped flange portion 16 provided on the outer periphery of the case.

The flange portion 16 and the flat portion 15 are connected to the spherical portion 1 so that the longitudinal cross-sectional shape of the case 2 as a whole is bowl-shaped.
They are connected by 7.

In this embodiment, the ratio of the depths of the cap 1 and the case 2 is approximately 1.

Note that the case 2 is provided with an annular recess 22 .

In this way, by bringing the ratio close to 1, the stiffness of both becomes approximately equal.

A rubber gasket 23 is fitted into the central opening of the case 2.

The case 2 is placed on a carburetor (not shown) via this gasket 23.

In addition, when the filter body 3 is housed in the case 2 and the cap 1 is attached to the case 2, the gasket 14 of the cap 1 comes into contact with the flange part 16 of the case 2, and in this state, the gasket 14 of the cap 1 comes into contact with the flange part 16 of the case 2. The gasket 14 portion is tightened to maintain airtightness between the cap 1 and the case 2.

Further, although the air cleaner having the above structure does not include an air introduction pipe, this air introduction pipe is fixed to the side wall of the case 2 by welding.

Next, FIGS. 5 and 6 show examples of actual noise level comparisons between the air purifier having the structure of the above embodiment and the air purifier having the conventional structure shown in FIG. 1.

FIG. 5 shows the results of measuring the noise level when the engine was in a no-load operating state and the engine speed was increased.

Moreover, FIG. 6 shows the results of measuring the sound pressure level for each frequency when the engine was kept at 3900 revolutions with no load.

In addition, both Figures 5 and 6 show the air purifier cap 1.
A noise measuring microphone was installed at a position 30 cm above the noise level.

Further, in the figure, the broken line indicates the conventional example, and the solid line indicates the present embodiment.

As is clear from the measurement results shown in FIGS. 5 and 6, it can be seen that the noise of this example is lower overall than that of the conventional example.

This is because the shapes of the cap 1 and case 2 are made as shown in FIG. 2 to increase the rigidity of both.

In the above embodiment, an odd number of nine ribs 9 are provided, and according to experiments conducted by the present inventor, it has been found that an odd number of ribs 9 is more effective in suppressing the vibration of the cap 1 than an even number of ribs. .

In addition, in the present invention, as shown in FIG.
As shown in the figure, a recess 24 may be provided in the inner circumference of the flat portion 12, and the recess 24 and the flat portion 8 may be connected by the spherical portion 13.

Furthermore, an odd number of ribs 25 may be provided in the case 2 as shown in FIG.

Furthermore, although the number of ribs 9 and concave portions 21 is nine in the above embodiment, the number is not limited to this number, and an even number may be used.

In the above embodiment, the cap 1 and the case 2 are made of metal, but of course they may be made of composite or resin.

Further, the airtight structure between the cap 1 and the case 2 via the gasket 14 is not limited to the above embodiment.

As described above, the present invention has the following advantages: (1) The filter body supporting flat part 8 of the cap 1 and the annular convex part 7 provided in the portion of the cap 1 corresponding to the inner peripheral part of the filter body 3 are By connecting the top side of the convex part 7 and the flat part 8 with several ribs 9, the rigidity of the inner circumference side of the filter body 3 of the cap 1 is increased, and ( 2) On the other hand, by connecting the outer peripheral part of the cap 1 and the flat part 8 with the spherical part 13 so that the longitudinal cross-sectional shape of the cap 1 as a whole becomes a bowl shape, the outer peripheral part of the filter body 3 of the cap 1 is (3) On the other hand, by connecting the outer peripheral part of the case 2 and the flat part 15 with the spherical part 17 so that the longitudinal cross-sectional shape of the case 2 as a whole becomes a bowl shape, the filter body 3 of the case 2 is improved. The rigidity of the outer circumferential side of the cap 1 is increased, so the cap 1
Due to the lack of rigidity, it is possible to avoid large vibrations of the cap 1 due to vibrations from the internal combustion engine, and the case 2 is also shaped with increased rigidity, so that the rigidity between the cap 1 and the case 2 can be balanced. Therefore, the present invention has the excellent effect of making it possible to reduce noise when vibrations are transmitted from the internal combustion engine to the air cleaner.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventionally used air purifier, Fig. 2 is a sectional view showing an embodiment of the air purifier of the present invention, Fig. 3 is a partial plan view of Fig. 2, and Fig. 4 is a sectional view showing an embodiment of the air purifier of the present invention. The figure is A- in Figure 3.
A sectional view, FIGS. 5 and 6 are characteristic diagrams for explaining the effects of the present invention, and FIG. 7 is a partial sectional view showing another embodiment of the present invention. 1...Cap, 2...Case, 3.
...Filter body, 7...Protrusion, 8...
・Plane part, 10... Top part, 9... Rib, 12... Plane part, 13... Spherical part,
15... Planar part, 17... Spherical part, 2
1... Concave portion.

Claims (1)

[Scope of utility model registration request] In an air cleaner for an internal combustion engine, an annular filter body for supplying clean air to the internal combustion engine is housed in a space formed between a cap and a case, and an end of the filter body is attached to the cap and the case. an annular protrusion protruding outward from the cap is provided in a portion of the cap that corresponds to the inside of the filter body, and the protrusion and the planar part of the cap several concave portions spaced apart from each other, and several concave portions located between the concave portions to connect the flat portion of the cap and the top side of the convex portion. The air for an internal combustion engine is characterized in that a rib is provided on the cap, and further, the outer peripheral part and the flat part of each of the case and the cap are connected by a spherical part so that the vertical cross-sectional shapes of the case and the cap are bowl-shaped as a whole. Purifier.