JPS58117350A - Air cleaner for internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to engine structures, and more particularly to air cleaners for internal combustion engines.

The present invention relates to the construction of an air cleaner in a stationary engine, used for driving internal combustion engines of motor vehicles, in particular automobile, ship, locomotive engines and the like, as well as generators, compressors, etc. It can be mainly applied when there is a need to reduce the noise level emanating from the suction system.

All automobile engines currently in use are equipped with means intended to reduce the amount of air-breathing noise. Ideally, this measure should simultaneously ensure both a sufficient and uniform supply of ambient air to the cylinders of the engine, while minimizing the amount of air intake noise.

The most common method is to line up the elements of the air cleaner housing, especially the filter cover with an acoustically absorbing porous material such as felt, wool, or plastic.

However, the sound absorption properties of these materials are estimated to be negligible, reducing the air-breathing noise by only /~3 dB (e.g. Eva, Mannostroeni Publication 1). Sunitsuneisyuma Avtomobilia “- Rona g, y, n.

by Lukan i n, Moscow, 79g/year, g
/~g2 page).

Much better results are obtained by using a resonant chamber as sound absorption means. It is customary to integrate the resonator in the air suction system with the air cleaner (see page g3, figure 3'7 of the above-mentioned publication). It has been shown in practice that uniform and better results are obtained when the resonant frequency matches the main natural frequency of the air suction tube. However, resonant chambers are characterized by complex shapes and dimensions.
On the other hand, the volume of this chamber is quite large.

A disadvantage inherent in such known air cleaners is that the resonant chamber is coupled to an air intake pipe that fills the air cleaner chamber and releases the noise into the atmosphere (in the above-mentioned construction, the air intake pipe is annular). gap or slot shape)
, as a result of not suppressing the vibrations of the final elements of the air intake system, which emit noise directly. In contrast, the noise emitted by the intermediate element is suppressed and
The spectrum and level of this noise is then modified by both the air cleaner chamber and the air intake pipe.

Air cleaners containing elongated smooth-surfaced conduits are also known (USSR Inventor's Certificate No. 3, No. 2, I PC
Fo, 2M 3! ; //, see 2). However, such a structure of the air cleaner gives rise to a large number of natural frequencies which induce noise radiation at these 41 sub-frequencies.

Air cleaners having a resonant chamber connected directly to the air intake pipe are also known. This resonant chamber is adapted to be connected to the air suction tube - by a hole on the blade side and on the other side through an annular gap between the inner and outer tubes (French Patent No. 3,93 g issue, IPCF
o, 2M 33100).

However, even in such a case, resonance of the air column within the air suction pipe is not effectively suppressed.

The reason for this is that - on the one hand, the holes communicate with the air suction pipe in the region of minimum pressure, and on the other hand, the arrangement of the resonator with respect to the air suction pipe is such that, in order to improve the efficiency of the resonator's action as a noise suppression means, This is because a special mold must be followed, and on the other hand the volume of the resonator as well as the number and position of the holes must be correlated.

An object of the present invention is to provide an air cleaner for an internal combustion engine, which makes it possible to efficiently and reliably suppress air intake noise generated at a resonance frequency within the air intake pipe by modifying the structure of the air intake pipe. That's true.

An air cleaner for an internal combustion engine that achieves this purpose consists of a housing with an air intake pipe fixed in a direction branching from an open end, an air intake pipe with radial holes, and a resonant housing adapted to surround the air intake pipe. In an internal combustion engine air cleaner comprising a chamber, according to the invention, the holes are arranged in a rows, -10,000 rows extending from the open end of the air intake pipe (0
,/~0. ．． 2) spaced apart by a distance L, the other column is
The flow area of each hole in the row is (0,02-0.7)S, spaced a distance (0,II~0)L from its open end
dog A, and the volume of the resonance chamber is (0,,2,t~o,
7) v, where L is the length of the air suction tube, S is the cross-sectional area of the air suction tube at the location of the radial hole, and ■ is the volume of the air suction tube. It is something to do.

This geometrical relationship between the radial holes, the dimensions of the communicator and the air suction tube provides efficient suppression of the resonance of the air column within the air suction tube, which is accompanied by a reduction in air suction noise.

In FIG. 1, an air cleaner for an internal combustion engine includes a housing 1 having a filter cover 2 and a filter element 3. The housing 1 has an inlet opening 4 and an outlet roller part 5.
It is equipped with The artificial opening 4 communicates with an air intake tube 6 having Ω rows 7 and 8 (FIG. 2) of calibrated holes 9 and 10 (FIGS. 1 and 2). A casing is attached to the air suction pipe 6, and the interior of the cage 7 defines a resonant chamber 11.

The air cleaner for an internal combustion engine according to the present invention operates as follows.

-r-7 When the engine is running, especially when the engine inlet valve is open, ambient air is drawn into the housing via the air intake pipe 6 and into the engine/nozzle/dazzle via the conduit system. further transported to. At the same time, the variable component of the volumetric flow rate of air during intake, which is determined by the amount of change in engine-to-cylinder displacement at the intake valve in the open position, is weakened in the air cleaner no. Noise and dust are emitted into the atmosphere through the open end of the screen. At the frequency determined by the following formula: However, f, - Frequency of vibration C - Speed of sound t - Length of air suction pipe -7, 2, 3... (sequence of natural numbers) Resonant vibration occurs (on both sides) (at the fixed frequency of the open air suction pipe) increases the noise radiation occurring at the open end of the air suction pipe 6. In order to suppress these, a resonance chamber 1 is defined by a Cane knob that tightly surrounds the outside of the air suction pipe 6 and its outer surface.
1 is provided parallel to the air suction pipe 6 by holes 9 and 10 grouped into λ sections of the air suction pipe 6.

During steady-state resonant oscillations of frequency fk, the air suction pipe 6
A standing wave is formed with distinct pressure wave antinodes and nodes in the length direction. The lowest frequency vibration (Fig. 2;
, second -) and third -3) are the most intense and have the largest sound pressure amplitude. The holes 9 and 10 are arranged in the air suction pipe 6 to ensure that air is forced through into the resonant chamber 11.
The sound energy is dissipated and converted into heat energy within the resonant chamber. Therefore, the resonance chamber 11 acts as if it were to smoothly dampen the mutual vibration of the frequency f, thereby reducing its vibration.

Range of flow areas for holes 9 and 10 in rows 7 and 8, respectively <0.0
2-〇, /) S (S is the cross-sectional area of the air suction pipe 6 at the location where the holes 9 and 10 are arranged) is the cross-sectional area of the air suction pipe 6 of the air cleaner used in modern automobiles. It covers the frequency range of the sound spectrum of synocular radiation at the lowest natural resonance form of the air volume, which can be effectively suppressed by the air cleaner proposed herein. If the area (F) of the hole is smaller than 0028, the attenuation will be weak and the air will not be effectively forced through the air suction pipe 6 into the resonance chamber 11. Conversely, if the area of the hole is 0. / S, the same amount of air Q determined by the volume of the resonant chamber 11 and the amplitude of the pressure oscillations is simultaneously forced through, the velocity of the gas forced through becomes smaller, and the other area This is because.

In order to suppress the initial low frequency vibration, the resonance chamber 11
The volume of is 0.0 of the volume of the air suction pipe 6. J 5-0.7
Must be double. When the relationship between the volumes is less than 0.25, the volume of air contained within the resonance chamber 11 is negligible and insufficient for the efficient operation of the camera camera 8. be. At values where the relationship between the volumes exceeds 0.7, when the areas of the holes 9 and 10 are in a predetermined optimal relationship, the decisive factor influencing the efficiency of noise reduction is the diameter of the calibrated hole 9 and is the resistance to flow in 10.

For values larger than 0.7, the dimensions of the resonant chamber 110 and the amount of metal consumed for its manufacture increase, while the strength of the connection between the air suction pipe 6 and the housing 1 increases. decreases.

Compared to known devices, the improved reliability of noise suppression by the resonant chamber 11 is due to the vibration antinode (ant 1node)
irrespective of whether a node of vibration (through which air is forced through efficiently) or a node of vibration (through which air is forced through inefficiently) lies in the area of the calibrated holes 9 and 10. , is ensured by the fact that the noise is effectively forced through into the interior of the resonant chamber 11. This means that the air suction pipe 6 has a conical contour, while the calibrated holes 9 and 10 are respectively (07-0..2) L from the air suction pipe 6.
and (0, group 0) two columns 7 separated by a distance of L
This is guaranteed by the fact that it is divided into 8K groups. In this case, if, for example, in one area of the row 7 or 8 of the calibrated holes 9 or 10 a pressure node is formed instead of a pressure antinode (the phase of the pressure and velocity of the vibration is offset by π/λ), to which air is forced through into the resonant chamber 11 due to the substantial difference in the amplitude of the pressure in the various sections of the suction pipe 6, which Accordingly, the air flow circulates from the air suction tube 6 into the resonance chamber 11 and from the resonance chamber 11 into the air suction tube 6 via the holes 9 and 10 in the rows 7 and 8. In other words, even in the above-mentioned case, the resonant chamber 11 acts and provides reliable noise suppression (see curve for the case of ==, ) for pressure P and velocity V). At the same time, analysis of the pressure curve at the lowest natural resonance form of vibration of the air volume in the air suction pipe of a known air cleaner shows that the coupling hole between the interior of the resonant chamber and the pipe is located at the pressure node (zero pressure areas), which reduces the efficiency with which these resonant pressures are forced into the interior of the resonant chamber.

1 The efficiency of the noise suppression produced by the air suction pipe by the device proposed here is shown in FIG. solid line a
shows the spectrum of the noise emitted through the air intake pipe 6 in a prior art air cleaner of an internal combustion engine, while the dashed line shows the noise spectrum for the here proposed air cleaner of an internal combustion engine.

As can be seen from the attached noise spectrum photo, the machine/generator equipped with air intake temperature control means was operated at full torque rotation (r
With the use of the present invention, while operating at 37S
It is possible to effectively suppress air intake noise in the frequency range between Hertz and 300 Hertz to a low level. The range from 37S to 300 Hertz characterizes the resonant radiation at the lowest natural vibrational form of the volume of air in the air suction pipe of the air cleaner.

The objects of the invention are achieved as described above.

[Brief explanation of drawings]

FIG. 1 shows an air cleaner for an internal combustion engine according to the invention. 2 FIG. 2 shows a curve depicting the distribution of the lowest form of the natural vibration of the air volume in the air suction pipe of the air cleaner according to the present invention. FIG. 3 depicts the advantageous effects obtained by the present invention. Represents a noise spectrum photograph. 1 Housing 2 Filter cover 3 Filter element 4 Artificial opening 5 Outlet opening 6 Air intake pipe 7.8 Row of holes 9.10 Holes 11... Resonance chamber. Continuing from page 1 ■ Inventor Yuri Petrovitch Lazarev Soviet Union Tolyatsky Kuibysiyevskoy Obrasti Pourvary Budenogo 14Kevy 56 ・n) Inventor Evgeny Vasilyevich Lysen Tolyatchi Kuibysiyevskoy Obrasti Leningradskaya Ulitsa 6 Kev 21

Claims (1)

[Claims] An air suction tube fixed in a direction branching from an open end, an air suction tube provided with radial holes, and a resonance chamber adapted to surround the air suction tube. In the air cleaner for an internal combustion engine, the holes 9, 10 are arranged in Ω rows 7, 8, each row having a distance (0, / ~ O, , 2) L from the open end of the air intake pipe 6. and the other row is spaced a distance (0, O3) L from its open end, and the flow area of each hole 9,100 in row 7.8 is (
002~0. / ) There is a thickness of S, resonance chamber 11
The volume of is (0,,2,S-~0.7)V, where shi is the length of the air suction pipe 6 and S is the radial hole 9, 1 (at the location of 1) An internal combustion engine characterized by the following: 1) Air cleaner, where f is the cross-sectional area of the air suction pipe 6, and (2) is the volume of the air suction pipe 6.