JP2000337127A - Muffler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a muffler provided with a function for purifying the harmful exhaust gas discharged from an internal combustion engine such as an automobile and a noise reducing function. SOLUTION: A muffler is provided with a noise reducing means 1 for lowering the exhaust noise, an exhaust accelerating part 11 provided in the noise reducing means 1 and having an accelerating passage 14 having a cross sectional diameter to be gradually reduced toward the downstream side and for accelerating flow of the exhaust gas, a negative pressure generating part 12 provided in the downstream side of the exhaust accelerating part 11 and for generating the negative pressure in a high speed area of the accelerated exhaust gas, and a suction passage 13 for connecting the negative pressure generating part 12 and the noise reducing means 1 to each other and for sucking a part of the exhaust gas of the upstream side to the negative pressure generating part 12 side with the generated negative pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muffler having a function of purifying harmful exhaust gas emitted from an internal combustion engine of an automobile or the like and a function of silencing the muffler.

[0002]

2. Description of the Related Art At present, the problem of air pollution has been greatly highlighted on a worldwide scale, and in particular, harmful exhaust gas emitted from an internal combustion engine of an automobile has become the most important issue that must be promptly improved. . Conventionally, mufflers that have a noise reduction function to reduce exhaust noise are broadly classified into manufacturer standard mufflers and sports mufflers, but a retrofit structure in which an exhaust gas purification device is connected to the downstream side of these existing mufflers by flanges or welding. Solved the above-mentioned problem.

[0003]

However, the conventional muffler has no function of purifying harmful exhaust gas discharged from the internal combustion engine. Although several types of exhaust gas purifying devices are sold, their functions vary, and there is no silencing function. For this reason, the exhaust gas purification device must be retrofitted to the muffler,
Depending on the type of vehicle, there is a problem that the exhaust gas purifying device hits the rear part of the vehicle body or projects greatly.

Accordingly, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a muffler having both a function of purifying harmful exhaust gas emitted from an internal combustion engine such as an automobile and a silencing function. Is to provide.

[0005]

Means for Solving the Problems Among the present invention to achieve the above object, the invention of claim 1 is a muffler, a muffler for reducing exhaust noise, and a muffler provided on the muffler, and is provided with a downstream side. An exhaust accelerating unit having an acceleration flow path with a gradually decreasing cross-section and accelerating the flow of exhaust gas, and a negative pressure generator provided downstream of the exhaust accelerating unit and generating a negative pressure in a high-speed region of the accelerated exhaust gas And a suction flow path that connects the negative pressure generating unit and the muffling unit, and suctions a part of the exhaust gas on the upstream side to the negative pressure generating unit side by the generated negative pressure. .

According to the present invention, in addition to the silencing function, the residual gas pressure in the cylinder can be reduced to promote complete combustion, thereby purifying harmful exhaust gas, purifying black smoke,
Various functions can be exhibited, including improved fuel efficiency and increased torque power. Therefore, it is not necessary to retrofit the exhaust gas purifying device, and it is possible to solve the problem that the exhaust gas purifying device hits the rear portion of the vehicle body or projects greatly.

Further, the invention of claim 2 is characterized in that an outside air intake port for taking in outside air is formed downstream of the negative pressure generating section. According to the present invention, it is possible to mix and diffuse the outside air into the exhaust gas, cool the exhaust gas, and discharge the exhaust gas to the atmosphere.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a muffler according to an embodiment, and FIG. 2 is a cross-sectional view showing a main part of the muffler of FIG. The muffler according to the embodiment is characterized in that it has both a function of purifying harmful exhaust gas emitted from an internal combustion engine such as an automobile and a function of silencing.

More specifically, the muffling means 1 for performing the muffling function is obtained by combining an interference type muffler 2, an expansion type muffler 3, and an expansion type muffler 4 having a partition wall which are sequentially connected from the upstream side to the downstream side. Become.

The interference type silencer 2 comprises one main exhaust pipe 6 extending from the end of the exhaust pipe 5 and two bypasses 7 branching from the end of the exhaust pipe 5. The main exhaust pipe 6 and the bypass 7 are assembled with different lengths. When the exhaust gas merges through the main exhaust pipe 6 and the bypass 7, the phase of the sound wave is shifted by a half wavelength. The structure is such that exhaust noise is reduced by interfering with each other.

The inflatable silencer 3 includes a tubular inflatable chamber 8, and the exhaust gas entering the inflatable chamber 8 is rapidly expanded to reduce the pressure, thereby attenuating a wide range of sound waves to mute the sound. It is a vessel. The inflatable silencer 4 with a partition wall has an exhaust passage 9 at the center, and a plurality of partition walls 10 having an annular cross section are provided concentrically around the exhaust passage 9, and small holes are formed in each of the partition walls 10. This is a silencer that moves and expands a part of the exhaust gas in the flow path 9 sequentially to the outside of the partition wall through the small holes to muffle the sound.

The function of purifying the harmful exhaust gas is to accelerate the flow of the exhaust gas from the exhaust passage 9 in the expansion type silencer 4 with a partition wall at a high speed to generate a negative pressure in a high speed region. It is obtained by sucking the exhaust gas on the upstream side by negative pressure. That is, an exhaust gas accelerating unit 11 is connected to the exhaust gas channel 9, and the exhaust gas channel 11 has an acceleration channel 14 whose diameter gradually decreases in section toward the downstream side, and has a structure for accelerating the flow of exhaust gas. Has become.

Downstream of the exhaust accelerating section 11, a negative pressure generating section 12 for generating a negative pressure in a high speed region of the exhaust gas is formed. In addition, between the negative pressure generating unit 12 and the inflatable silencer 4 with the partition wall, a suction flow for sucking the exhaust gas in the inflatable silencer 14 with the partition wall toward the negative pressure generating unit 12 due to the generated negative pressure. A passage 13 is formed. The negative pressure generator 1
An outside air intake port 15 for taking in outside air is formed downstream of 2.

Next, the operation of the muffler having the above configuration will be described. First, regarding the silencing effect, when the exhaust gas discharged from the internal combustion engine reaches the interference type silencer 2, when the exhaust gas joins through the main exhaust pipe 6 and the bypass 7, the main exhaust pipe 6 and the bypass 7 The phase of the sound wave is shifted by a half wavelength and interferes with each other due to the difference in the flow path length between them, and the exhaust sound is attenuated by the cancellation.

When the exhaust gas that has passed through the interference type silencer 2 reaches the expansion type silencer 3, the exhaust gas that has entered the expansion chamber 8 expands abruptly, and its pressure drops. Decay.

When the exhaust gas that has passed through the inflatable silencer 3 reaches the inflatable silencer 4 with a partition, a part of the exhaust gas in the exhaust channel 9 flows into the outside of the partition 10 sequentially through the small holes. Each time it expands, the exhaust noise is muted.

With respect to the action of purifying harmful exhaust gas, which is the gist of the embodiment, when the exhaust gas in the exhaust flow passage 9 reaches the exhaust acceleration unit 11, the acceleration flow passage 14 has a shape narrowed toward the downstream side. The exhaust gas is accelerated as it flows.

In the negative pressure generating section 12, immediately after exhaust gas is emitted from the exhaust accelerating section 11, the exhaust gas flows at the highest speed, and in this high speed region, a negative pressure corresponding to the high speed is generated.
Since the generated negative pressure acts on the inflatable silencer 4 with the partition via the suction flow path 13, the exhaust gas in the inflatable silencer 4 with the partition is sucked toward the negative pressure generating unit 12 side, and the mainstream exhaust gas is exhausted. Merge with gas.

Further, since the outside air intake port 15 for taking in outside air is formed downstream of the negative pressure generating section 12, a negative pressure corresponding to the flow rate of the exhaust gas is generated. As a result, the outside air is sucked from the outside air suction port 15, mixed and diffused into the exhaust gas, cools the exhaust gas, and is discharged into the atmosphere together with the exhaust gas.

As described above, the negative pressure generated by the negative pressure generating section 12 causes a part of the exhaust gas on the upstream side to be reduced.
Since the suction is performed on the two sides, the pressure of the residual gas remaining in the cylinder can be reduced. As a result, the intake of a new air-fuel mixture is promoted, and complete combustion can be improved. As a result, in addition to the noise reduction function, it is possible to exhibit various functions such as purification of harmful exhaust gas, purification of black smoke, improvement of fuel efficiency, and increase of torque power.

As a result, it is possible to provide a muffler having both a function of purifying harmful exhaust gas discharged from the internal combustion engine and a function of silencing, so that it is not necessary to retrofit an exhaust gas purifying device, and the exhaust gas purifying device hits a rear portion of a vehicle body. Or the problem of large protrusion can be solved.

Further, since the outside air suction port 15 for taking in outside air is formed on the downstream side of the negative pressure generating section 12, the outside air can be mixed and diffused into the exhaust gas, and the exhaust gas can be cooled and discharged to the atmosphere. .

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made. For example, the present invention can be applied not only to automobiles but also to diesel freight vehicles, forklifts, and construction machines, and can also be applied to ships, motorcycles, and agricultural machines as applied fields.

[0024]

As is apparent from the above description, according to the first aspect of the present invention, the flow rate of the exhaust gas in the muffler is increased, and a negative pressure is generated in a high-speed region. The exhaust gas on the upstream side is suctioned by the pressure, so in addition to the silencing function, the residual gas pressure is reduced to promote complete combustion, thereby purifying harmful exhaust gas, purifying black smoke, improving fuel efficiency, and improving torque power. A variety of functions can be exhibited up. Therefore, it is not necessary to retrofit the exhaust gas purifying device, and it is possible to solve the problem that the exhaust gas purifying device hits the rear portion of the vehicle body or projects greatly.

Further, according to the second aspect of the present invention, since the outside air intake port for taking in outside air is formed downstream of the negative pressure generating portion, the outside air is mixed and diffused into the exhaust gas, and the exhaust gas is cooled to cool the air. Can be released into.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a muffler according to an embodiment.

FIG. 2 is a sectional view showing a main part of the muffler of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Silencer 2 Interference type silencer 3 Expansion type silencer 4 Expansion type silencer with a partition 5 Exhaust pipe 6 Main exhaust pipe 7 Bypass 8 Expansion chamber 9 Exhaust flow path 10 Partition 11 Exhaust acceleration part 12 Negative pressure generation part 13 Suction flow Road 14 Acceleration channel 15 Outside air inlet

Claims (2)

[Claims] An exhaust accelerating unit provided in the silencing unit, the acceleration accelerating unit having an accelerating flow path whose diameter gradually decreases toward the downstream side, and accelerating the flow of exhaust gas; A negative pressure generator, which is provided downstream of the exhaust acceleration unit and generates a negative pressure in a high-speed region of the accelerated exhaust gas, is connected to the negative pressure generator and the silencing means. A muffler comprising: a suction flow path for suctioning a part of the exhaust gas to a negative pressure generating unit side. 2. The muffler according to claim 1, wherein an outside air intake port for taking in outside air is formed downstream of the negative pressure generating section.