FI124220B - exhaust muffler - Google Patents

Description

exhaust muffler

The present invention relates to an exhaust-gas silencer according to the preamble of claim 1, comprising a casing to be connected to the exhaust pipe through which the exhaust gases are arranged to be conducted and having a flow-reactive portion of the exhaust gases and an absorbent portion.

Big internal combustion engines generate noise, a significant source of which is 10 engine exhaust noise, which is mainly due to pressure fluctuations between the engine cylinders and the outside air. Various silencers for attachment to the exhaust manifold or exhaust pipe are known in the art. The problem is to combine a sufficiently effective silencer with a relatively simple and inexpensive design that does not cause the exhaust system too high backpressure.

JP 2-112911 U discloses an exhaust silencer for an internal combustion engine comprising a housing through which the exhaust gases are arranged to be conducted. The damper has a reactive part and an absorbent part. The reactive portion 20 has three separate chambers, and from the reactive portion the exhaust gases are directed directly through a pipe mounted in the middle of the absorbent portion. The structure known from the publication is complicated and not suitable for large engines.

FR 2392228 A discloses an exhaust silencer for an internal combustion engine.

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o 25 nin with reactive and absorbent moiety. The exhaust gases are passed through the absorbent part A via a pipe arranged in the center thereof. Also known from this publication, the co solution is unsuitable for large engines due to their complex structure

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It is an object of the invention to provide a better solution to the aforementioned problem, particularly with regard to exhaust silencer ™ for large internal combustion engines. In particular, it is an object of the invention to provide an exhaust gas muffler which effectively eliminates various vocalization frequencies in a structurally advantageous manner. Another object of the invention is to provide a silencer which is also capable of purifying exhaust gases.

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The objects of the invention are mainly achieved in the manner detailed in claim 1 and other claims. According to the invention, the reactive portion of the silencer is essentially hollow and has an inlet end having a first exhaust pipe for supplying exhaust gases to the reactive portion 10 and an outlet end having a second exhaust outlet for introducing exhaust gases from the reactive portion to The absorbent member comprises an absorbent filler element which substantially fills the absorbent portion of the housing and is shaped at the inlet end 15 of the absorbent portion to direct the exhaust gases into the space between the filler element and the housing casing.

The structure according to the invention can efficiently attenuate the low frequencies, mid frequencies and high frequencies of the engine compression, while still being as simple as possible. The solution is also advantageous in terms of the total back pressure exerted by the exhaust system.

Said first and second exhaust pipes are preferably dimensioned to attenuate the lowest frequencies of the exhaust noise by utilizing mutual attenuation interference of the sound waves. In this case, further mentioned

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The opposing orifices of the first and second exhaust pipes are spaced apart. In practice, said first para gas pipe extends into the reactive portion about a quarter of the total length of the reactive x portion. Correspondingly, said second exhaust pipe extends

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about half of the total length of the reactive portion.

δ 30 ra o By arranging a spark quench between the reactive part and the absorbent part

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This means that the soot particles in the exhaust gases can be effectively separated before the exhaust gases are discharged into the environment. The purpose here is not only to purify the exhaust gases as such, but also to prevent sparks from escaping from the exhaust pipe, possibly causing fire safety risks.

Preferably, the spark arresting means comprises a plurality of radially extending plate members configured to guide the exhaust gas stream in a rotating motion around the fill member. Thus, the centrifugal force can effectively guide the soot particles to the inner casing of the housing. Thus, by providing the absorbent member in the housing with the spark extinguishing means 10 after the spark extinguishing means, the soot particles can be recovered and, if necessary, easily removed from the housing.

By guiding the exhaust gases towards the inner surface of the housing, the distance between the housing and the filler element can be made relatively small compared to the diameter of the filler element. In this case, the total cross-sectional area of the gap can be considered large enough so that the arrangement does not significantly increase the back pressure of the exhaust silencer. All in all, this arrangement also contributes to the improvement of mid- and high-frequency attenuation.

In order to effectively control the exhaust gases, the filler element is preferably sharp-pointed and preferably conical on the side of the reactive part.

Preferably, the padding element is mainly rock wool, which is housed within the housing within a supported perforated plate, mesh or the like.

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δ 25 c \ j -J- The housing is preferably positioned vertically in the operating position so that the para gas is fed into the housing from below.

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The invention will now be described, by way of example, with reference to the accompanying drawings in which: o - Figure 1 illustrates an embodiment of the silencer according to the invention

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and Fig. 4 is a perspective view of the silencer of Fig. 1 with the silencer housing open with the absorbent material removed.

Reference numeral 1 denotes a muffler housing that is attached to a combustion engine exhaust manifold to direct exhaust gases through the muffler. The housing 1 comprises a reactive portion 2 and an absorbent portion 3 arranged in succession in a flow direction.

The reactive portion 2 is for attenuating low noises and is provided with a first exhaust pipe 5 through which the exhaust gases are fed into a housing 1 and a second exhaust pipe 6 spaced from the first exhaust pipe 5 and through which the exhaust gases are directed to the 3, which in turn provides for attenuation of mid- and high-frequency exhaust noise before exhausting the exhaust gases from the silencer to the environment.

To attenuate low noises, the first exhaust pipe 5 extends within the reactive portion 2 to about a quarter of the total length of the reactive portion 2. Correspondingly, the second exhaust gas pipe 6 extends into the reactive part 2 about 20% of the total length of the reactive part 2. This low noise can be effectively attenuated by taking advantage of the interference suppression of the sound waves. In addition, in order to improve the efficiency of silencing, dimensioning should take into account the ignition frequency of the internal combustion engine and the diameters of the silencer and engine exhaust, as well as

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δ 25 Requirements in each case.

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The absorbent member 3 has a filler element 7, preferably of rock wool and x surrounded by a perforated sheet material supported on the housing 1,

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collet or the like. The filling element 7 is conically shaped at its end on the side of the reactive portion 2 so that the exhaust gases are directed to the space 8 between the inner shell of the housing 1 and the filling element 7 for further extraction.

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The spark arresting means 4 include a plurality of radially extending plate elements 9 configured to direct the exhaust gas stream in a rotating motion around the filler element 7. The rotary motion thus obtained is capable of guiding the soot particles heavier than the exhaust gases towards the inner casing of the housing 15, from which they can be easily collected and removed from the housing through the longitudinal soot hood 10.

The silencer according to the invention is preferably rotationally symmetrical in structure and can preferably be positioned vertically as required by the application. In this position the soot hatch is also easily opened and emptied.

The structure of the silencer according to the invention is advantageous in terms of the total back pressure exerted on the exhaust system. In addition, it is easily integrated with spark arresting means, which at the same time contribute to the exhaust gases radially outwardly towards the inner casing of the housing.

The invention is not limited to the embodiment shown, but many variations are conceivable within the scope of the appended claims.

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Claims (11)

An internal combustion engine exhaust silencer, comprising a coupler housing (1) coupled to the exhaust pipe, through which the exhaust gases are arranged to be directed and the flow direction of the exhaust gas has a reactive portion (2) and an absorbent portion (3), wherein the reactive portion (2) ) is substantially hollow and at its feed end there is a first exhaust pipe (5) for feeding the exhaust gases to the reactive part (2), and at its outlet end there is a second exhaust pipe (6) for passing the exhaust gases from the reactive part (2). to the absorbent member (3), wherein both exhaust pipes 10 (5, 6) of the reactive member (2) are arranged to extend substantially into the reactive member (2) of the housing, characterized in that in the absorbent member (3) ) is provided with an absorbent filler element (7) which substantially fills the absorbent portion (3) of the housing and is so shaped at the feed end of the absorbent portion (3) that it directs the exhaust gases from the center region of the housing (1) into a space (8) between 15 lan the filling element (7) and the inner sheath of the housing (1). Silencer according to Claim 1, characterized in that said first and said second exhaust pipes (5, 6) are dimensioned to attenuate the lowest frequencies of the exhaust sound by utilizing the muting interference of the sound paths. Silencer according to Claim 1 or 2, characterized in that said first and said second exhaust pipes (5, 6), opposite to each other, are arranged at a distance from each other. CO δ 25 c \ j -A Silencer according to any one of the preceding claims, characterized in that the insertion distance of said first exhaust pipe (5) in the reactive part (2) is about x about a quarter of the total length of the reactive part (2). CL CO o 30 Silencer according to any of the preceding claims, characterized in that the insertion distance of said second exhaust pipe (6) in the reactive part (2) is approximately C about half of the total length of the reactive part (2). Silencer according to any of the preceding claims, characterized in that between the reactive part (2) and the absorbent part (3) there are spark extinguishing means (4). 5 A muffler according to claim 6, characterized in that the spark extinguishing means (4) consist of a plurality of radially directed disc elements (9) which are designed to control the exhaust gas flow to carry out a rotary movement around the filling element (7) in the absorbent part (3). . 10 Silencer according to claim 6 or 7, characterized in that on the housing (1), in conjunction with the absorbent part (3), after the spark extinguishing means (4), a soot lid (10) parallel to the longitudinal direction of the housing (1) is provided for collecting up soot particles and, if necessary, remove them from the housing (1). 15 Silencer according to any one of the preceding claims, characterized in that the filling element (7) is pointed and raised conically against the reactive part (2). Silencer according to any of the preceding claims, characterized in that the filling element (7) is mainly of rock wool arranged inside a heel plate, a net or the like supported / supported against the housing (1). 11. Silencer according to any of the preceding claims, characterized in that the housing (1) is in vertical position so that the exhaust gases are measured to the housing (1) from below. c \ j i oo c \ j X cc CL CO δ m oo o o c \ j