JPS5843661Y2 - Air purifier with silencer - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an air purifier equipped with a secondary air purifying filtration element for supplying clean secondary air to a secondary air supply source such as the exhaust system of an automobile engine. Specifically, the present invention relates to an air purifier with a muffling device for muffling the sound emitted from the secondary air supply source into the atmosphere through the inside of the air purifier.

Conventionally, in relation to automobile exhaust countermeasures, the exhaust system of the engine,
A system has been adopted that uses the exhaust pulsation to introduce secondary air.

In this system, the air purifier and the exhaust system are connected by a conduit, and a reed valve is placed in the middle of this conduit, and the negative pressure accompanying the exhaust pulsation of the exhaust system acts on the reed valve, causing the reed valve to open and close. , whereby the clean secondary air that has passed through the secondary air filtration element of the air purifier is introduced into the exhaust system through the conduit.

In such conventional exhaust systems, the sound generated when the reed valve opens and closes is emitted into the atmosphere through the intake pipe of the air purifier, following a path opposite to the secondary air introduction path, resulting in a significant amount of noise. There's a problem.

In recent years, noise regulations have become increasingly strict, and it is therefore urgent to muffle the above-mentioned noises.

The present invention was devised in view of the above points, and a secondary air introduction passage is provided inside the case in which the secondary air cleaning filtration element is installed to introduce the secondary air into the filtration element. A cover that has an opening in the middle on the side where the secondary air introduction passage is located, and that covers this opening in accordance with the first rule to form a silencing resonance chamber that is closed to the outside between the outside of the case and the outside of the case. is provided on the outside of the case, and this silencing resonance chamber is communicated with the secondary air introduction passage through the opening of the case, so that when the sound generated by the secondary air supply source passes through the secondary air introduction passage, The energy is attenuated within this passage, and the sound generates a sound wave of the same wavelength in the sound-damping resonance chamber through the opening of the case, which interferes with and is attenuated.
Furthermore, the sound is emitted into the case from the secondary air introduction passage and is diffused within the case, so even if the sound is emitted to the outside of the air purifier, it does not become noise, making this an air purifier equipped with a muffling device that has excellent muffling effects. The purpose is to obtain.

An actual case in which the present invention is applied to an air purifier for a secondary air supply device for purifying exhaust gas will be described below.

First, the relationship between the secondary air supply device and the air cleaner will be explained with reference to FIG.

The air purifier 1 houses a ring-shaped primary air cleaning filtration element 12 that supplies clean air to the vaporizer 3, and a secondary air filter element 12 that supplies clean air to the exhaust pipe 4 in the peripheral wall. A cleaning filter element 13 is attached.

The reed valve 2 has a valve seat 2a made of aluminum, a valve body 2b made of stainless steel, and a regulation plate 2c made of stainless steel that regulates the opening degree of the valve body 2b.

The valve body 2b of this reed valve 2 allows air flowing in from the air purifier 1 side to pass through, but the air supply valve (not shown)
When the exhaust valve 7 and the exhaust valve 7 overlap, the exhaust gas in the exhaust pipe 4 flowing backward from the conduit 9 side is not allowed to pass through.

In the figure, 5 indicates an intake pipe, 6 indicates a cylinder head, and 8 indicates a secondary air introduction pipe.

Next, the detailed structure of the air purifier with a silencer according to the present invention will be explained.

In FIGS. 2 and 3, a ring-shaped primary air cleaning filter element 12 is housed in a case 11. As shown in FIGS.

A casing 14 is attached to the outside of the peripheral wall 11a of this case 11 with screws 16.
A rectangular secondary air cleaning flow element 13 is installed between the housing 11 and the peripheral wall 11a of the case 11.

This casing 14 is provided with a pipe 15 connected to the secondary air introduction pipe 8 shown in FIG.

A secondary air introduction passage 20 is provided inside the peripheral wall 11a of the case 11 by a plate 1B that is airtightly joined by welding along the arcuate surface of the peripheral wall 11a.

This secondary air introduction passage 20 communicates with the secondary air cleaning flow element 13 via a small hole 22 provided in the peripheral wall 11a of the case 11, and this small hole 22 and the secondary air introduction passage 2
It is separated by a long distance from the entrance portion 20a of No. 0.

Two small holes 23 are provided in the middle of the peripheral wall 11a of the case 11 on the side where the secondary air introduction passage 20 is located. A cover 17 forming a silencing resonance chamber 19 is engaged with the peripheral wall 11a of the case 11 by welding.

In the figure, 10 is an intake pipe, and 21 is a lid.

In the above configuration, the operation will be explained.

When the exhaust valve 7 and the intake valve overlap, the vicinity of the exhaust valve 7 becomes negative pressure, and the valve body 2 of the reed valve 2
b opens.

Therefore, after the secondary air is taken into the case 11 through the intake pipe 10, it is guided to the secondary air introduction passage 20 through the inlet 20a of the secondary air introduction passage 20, and the secondary air is introduced into the secondary air introduction passage 20 through the small hole 22 provided in the case 11. More secondary air cleaning filtration element 13
After passing through the pipe 15 and the inlet pipe 8, it is guided to the riet valve 2 and introduced into the exhaust pipe 4.

The exhaust sound near the exhaust valve 7 that propagates when secondary air is supplied, and the valve seat 2 when the valve body 2b of the reed valve 2 closes.
The sound that collides with a follows a path in the opposite direction to the above-mentioned secondary air supply path as a sound wave.

Therefore, the sound waves transmitted to the secondary air introduction passage 20 are
The energy is attenuated while reaching the entrance 20a of the secondary air introduction passage 20, and furthermore, the energy is attenuated by resonance in the resonance frequency region of the silencing resonance chamber 19 communicated with the small hole 23.

Therefore, the sound pressure level of the sound waves emitted into the case 11 from the inlet 20a of the secondary air introduction passage 20 becomes very small, and is further diffused inside the case 11 and further muffled, so that the air intake pipe The sound pressure level emitted into the atmosphere from No. 10 poses no problem in terms of noise.

4 and 5 show a second practical example of the present invention, which extends the length of the secondary air introduction passage 20, improves the silencing effect of the silencing resonance chamber 19, and widens the frequency range. This is an attempt to obtain a silencing effect in the area.

That is, in order to extend the secondary air introduction passage 20, another plate 24 is joined and this plate 24 and the plate 18 are connected.
A secondary air introduction passage 25 having an inlet 25a is formed by this.

FIGS. 6 and 7 show the third embodiment of the present invention, which is provided with a plurality of silencing resonance chambers having different volumes. A fourth example is shown.

The silencing characteristics of a silencing resonance chamber are greatly influenced by the single resonant frequency range, so by providing multiple silencing resonance chambers each set to a different resonance frequency, it is possible to achieve sound reduction over a wide frequency range. Can be muted.

In the third embodiment shown in FIG. 6, a small hole 23a is provided in the bottom of the case 11 on the side where the secondary air introduction passage 20 is provided, and a small hole 23b that matches the small hole 23a is provided in the cover 17. Another cover 17a is welded to the bottom of the one resonance chamber 19, and another silencing resonance chamber 19a is formed at the bottom of one of the resonance chambers 19, and this silencing resonance chamber 19a is communicated with the secondary air introduction passage 20. be.

On the other hand, the fourth embodiment shown in FIG. 7 has a structure in which another silencing resonance chamber 19a is spaced apart from one silencing resonance chamber 19 by a distance.

8 to 13 show a fifth embodiment of the present invention in which the structure of the small hole 23 for communicating the secondary air introduction passage 20 and the silencing resonance chamber 19 shown in the first actual case of FIG. 2 is changed. Examples to Example 8 will be shown.

FIG. 8 shows a fifth embodiment in which a plurality of burring-shaped small holes 23 are provided, and FIG. 9 shows a sixth example in which a pipe 27 is joined to the small holes 23 by welding.

FIGS. 10 and 11 show a seventh embodiment in which a plate 28 having a groove or arc shape in cross section is fixed by welding to the outside of the silencing resonance chamber 19 of the peripheral wall 11a of the case 11.
3 is covered with a plate 28.

12 and 13 show a small hole 23 with a louver 29.
An eighth embodiment is shown below.

FIG. 14 shows a ninth embodiment of the present invention in which a reed valve 2' is directly provided by a casing 31 having a pipe 15 on the outside of a housing 14 in which a flow element 13 for secondary air purification is mounted. , other structures are shown in Fig. 4, 2
The structure of actual cases is adopted.

Next, it will be described that the air purifier according to the present invention has an excellent noise reduction effect.

An air purifier A having the structure of the first embodiment shown in FIGS. 2 and 3 is prepared, and is equipped with a silencing resonance chamber 19, a secondary air introduction passage 20, and a small hole 23 as shown in FIG. A conventional air purifier B having the same structure as that shown in FIG. 2 was prepared, and an air purifier C having the structure of the second actual case shown in FIGS. The difference in the silencing effect was experimentally determined.

The results are shown in FIG.

FIG. 15 is a characteristic diagram showing the relationship between the frequency of a given sound and the sound pressure level of the sound emitted into the atmosphere from the intake pipe 10 of the air purifier, and the solid line is from the air purifier B above. The broken line indicates the sound pressure level characteristics of the generated sound, and the broken line indicates the second
The structure of the second embodiment shown in FIGS. 4 and 5 shows the sound pressure level characteristics of the sound generated from the air purifier having the structure of the first embodiment shown in FIGS. This shows the sound pressure 17/bell characteristics of the sound generated from the air purifier.

As is clear from the comparison of the lines in FIG. 15, it can be seen that the air purifier having the silencing resonance chamber of the present invention has an extremely excellent silencing effect.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and the sound damping effect can be further improved by filling the inside of the sound damping resonance chambers 19, 19a with a sound absorbing material such as glass wool.

In addition, the case 11, cover 17 in each of the above embodiments,
Although the plate 18 and the like are made of metal, they may of course be made of strong synthetic resin.

As detailed above, in the present invention, the secondary air cleaning flow element for the target secondary air supply source is attached to the case housing the primary air cleaning flow element for the target air supply source, A secondary air introduction passage for introducing secondary air into the secondary air cleaning flow element is provided inside the case, and an opening is provided in the middle of the case on the side where the secondary air introduction passage is located, and A cover is provided on the outside of the case that covers this opening on the outside and forms a silencing resonance chamber closed to the outside between the case and the outside of the case, and the silencing resonance chamber and the secondary air introduction passage are connected to the outside of the case. Since the communication is made through the opening, the sound generated by the secondary air supply source follows the reverse path of the secondary air introduction path, but in this case, the sound is transmitted through the opening in the peripheral wall of the case and into the sound-dampening resonance chamber. A sound wave of the same wavelength is generated, and this sound wave and the sound wave of the above-mentioned sound interfere, and the sound pressure of the above-mentioned sound is attenuated.Also, the sound passes through the secondary air introduction passage, so it travels through this passage to the inside of the case. The sound pressure of the sound is also attenuated,
Furthermore, the sound is diffused inside the case, so the sound is muffled, and even if it is emitted to the outside of the air purifier, there is an excellent effect that there is no adverse effect as noise.

[Brief explanation of the drawing]

Figure 1 is for explaining the present invention, and is a sectional view showing the relationship between the air cleaner and the secondary air supply device, and Figure 2 is a partially assembled sectional view showing the first actual case of the air cleaner of the present invention. , FIG. 3 is a sectional view taken along the line A-A in FIG. 2, FIG. 9 to 9 are sectional views showing the main parts of the third to sixth embodiments of the present invention, FIG. 10 is a sectional view showing the main parts of the seventh embodiment of the invention, and FIG. 11 is a sectional view showing the main parts of the seventh embodiment of the invention. 10 is a sectional view taken along line C-C in FIG. 10, FIG. 12 is a sectional view showing the essential parts of the eighth embodiment of the present invention, FIG. 13 is a sectional view taken along line DD in FIG. 12, and FIG. FIG. 15 is a cross-sectional view showing the main parts of the ninth embodiment, and is a sound characteristic diagram for explaining the effects of the air purifier of the present invention. 2... Reed valve, 3... Carburizer serving as a source of secondary air supply, 4... Exhaust pipe serving as a source of secondary air supply, 11... ...Case, 12...
...-Next air purification filtration element, 13...
・Secondary air cleaning flow element, 17, 17a...
...Cover, 18...Plate, 19,19
a... Sound deadening resonance chamber, 20°25...
Secondary air introduction passage, 23...Small hole forming an opening.

Claims (1)

[Scope of utility model registration request] The case includes a primary air cleaning filter element that supplies clean air to the secondary air supply source, and a secondary air cleaning filter element that supplies clean air to the secondary air supply source. In the air purifier equipped with the above, a secondary air introduction passage for introducing secondary air to the secondary air purifying lightning over element is provided inside the case, and the secondary air introduction passage is located in the case. An opening is provided in the middle of the side where the noise is to be removed, this opening is covered from the outside of the case, and a cover is provided between the case and the outside to form a sound-reducing resonance chamber closed to the outside. An air purifier with a muffler, characterized in that a resonance chamber is connected to the secondary air introduction passage through an opening of the case.