JPH036806Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a muffler installed in an exhaust system of an internal combustion engine.

[Conventional technology]

Conventionally, as a muffler for an internal combustion engine, for example, a third muffler is used.
The one shown in Fig. 4 is known.

The silencer shown in FIG. 3 has end plates 11 and 12 at both ends.
The inside is closed with three partition plates 13, 14, 15.
It includes an outer cylinder 1 defined into four compartments A, B, C, and D, and an exhaust gas introduction pipe 2 and an exhaust gas discharge pipe 3 that communicate the inside and outside of the external cylinder 1. The exhaust gas introduction pipe 2 has a gas inlet end 21 located outside the outer cylinder 1, and a gas outlet end 22 that opens into the third compartment C, and connects the first and second compartments A and B. It is arranged so that it penetrates. The exhaust outlet pipe 3 has a gas inlet end 31 that opens into the first compartment A, a gas outlet end 32 that is located outside the outer cylinder 1, and a gas outlet end 32 that opens into the first compartment A, and which opens into the second, third, and fourth compartments B and C. , D. Also, a large number of small holes 4 for communicating the first, second, and third compartments A, B, and C.
A conduit 4 having a diameter is disposed so as to pass through the partition plates 13 and 14, and these compartments A, B, and C are configured to serve as expansion chambers. Furthermore, a resonator pipe 5 is provided on the partition plate 15 so as to face the gas outlet end 22 of the exhaust gas introduction pipe 2, and the fourth compartment D is configured to serve as a resonator chamber.

The flow of exhaust gas in this muffler is shown by an arrow, and the exhaust gas discharged from the gas outlet end 22 of the exhaust introduction pipe 2 expands in the third compartment C and is rotated approximately 180 degrees. Enter conduit 4, the second
The exhaust pipe 3 is further expanded in the first compartments B and A, and rotated approximately 180 degrees in the first compartment A.
The gas enters the gas inlet end 31 of the.

The silencer shown in Fig. 4 is known as Utility Model Application No. 60-120214, and has a structure in which the second compartment B and conduit 4 in Fig. 3 are omitted. Instead, a portion of the exhaust inlet pipe 2 that penetrates into the first compartment A, and a portion of the exhaust outlet pipe 3 that penetrates the third compartment C (second in this muffler), respectively. A large number of small holes 23, 33 are bored.

The flow of exhaust gas in this muffler is also shown by arrows, and the exhaust gas that has flowed into the exhaust introduction pipe 2 is branched and expanded from the small hole 23 to the first compartment A, and the exhaust gas flows into the exhaust outlet pipe 3. The remaining branch flow enters the inlet end 31 and expands from the gas outlet end of the exhaust gas introduction pipe 2 to the third compartment C and enters the exhaust gas outlet pipe 3 through the small hole 33.

[Problem that the invention attempts to solve]

The above-mentioned muffler shown in FIG. 3 has a problem in that the exhaust pressure increases and the air flow noise increases because the exhaust gas is swirled. Furthermore, there is a problem in that pressure loss increases due to rapid expansion.

Further, the muffler shown in Fig. 4 largely eliminates the problems of the muffler shown in Fig. 3, but the divided exhaust gases enter the exhaust outlet pipe 3 separately, so the noise attenuation function is degraded. There is a problem.

[Purpose of invention]

This invention was devised to solve these conventional problems, and its purpose is to reduce pressure drop and exhaust pressure without reducing the noise attenuation function, and to reduce the exhaust pressure of internal combustion engines, including the muffler. The objective is to improve the flow of exhaust gas in the system.

[Means for solving problems]

The silencer for an internal combustion engine according to the present invention includes an outer cylinder whose both ends are closed with end plates and whose interior is defined by a partition plate into a plurality of compartments, and an exhaust inlet pipe and an exhaust outlet that communicate with the inside and outside of the outer cylinder. In a silencer for an internal combustion engine, the exhaust inlet pipe passes through at least one compartment to open its gas outlet end to a second and subsequent compartments, and each compartment of the exhaust inlet pipe A large number of small holes are bored in the penetrating portion, and a conduit is provided in each of the partition plates defining compartments through which an exhaust gas introduction pipe passes or the gas outlet end thereof is open, and these compartments are used as expansion chambers;
The exhaust outlet pipe is inserted into a compartment in which the gas outlet end of the exhaust introduction pipe is open, the gas inlet end of the exhaust outlet pipe is closed, and a large number of small holes are bored in the penetrated portion.

[Operation of the invention] The silencer for an internal combustion engine according to the invention merges the exhaust gases that are separated from the exhaust inlet pipe and discharged before being introduced into the exhaust outlet pipe, thereby reducing the pressure loss and reducing noise without reducing the noise damping function. This reduces exhaust pressure.

[Example of idea]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a muffler for an internal combustion engine according to the present invention will be described below with reference to FIGS. 1 and 2.

Figure 1 shows the basic principle of this invention.
As can be understood from a comparison with the conventional example shown in FIG. 4, the characteristic is that the gas inlet end 31 of the exhaust outlet pipe 3 is closed and both compartments A and C are communicated through a conduit 6.

That is, the exhaust gas branch flow from the exhaust gas introduction pipe 2 is interfered and mixed in the compartment C by the conduit 6 and enters only the small hole 33 of the exhaust gas discharge pipe 3, so that the noise damping function is prevented from deteriorating. be.

Figure 2 shows the specific structure of the present invention, and the configuration of the outer cylinder 1 and the compartments A, B, C, and D is the third one.
This is the same as in the figure, and the configurations of the exhaust gas introduction pipe 2 and the exhaust gas discharge pipe 3 are substantially the same as in FIG. The small holes 23 bored in the exhaust gas introduction pipe 2 are connected to the first and second compartments A,
The gas inlet end 31 of the exhaust outlet pipe 3 is closed by fitting the plug 7 thereto.

In such a structure, the exhaust gas flowing into the exhaust introduction pipe 2 from the gas inlet end 31 is branched and expanded into the first and second compartments A and B through the small hole 23, and the exhaust gas flows through the gas outlet end. The flow is also branched and expanded to the third compartment C through 22. Therefore, in the exhaust gas introduction pipe 2, the exhaust gas is gradually branched and expanded, and the flow velocity of the exhaust gas is gradually reduced, resulting in a reduction in pressure loss. Incidentally, if the number of such compartments A and B is increased, the reduction in pressure loss will be further improved, but the gas outlet end 2 of the exhaust introduction pipe 2
If the resonator pipe 5 is provided so as to face the resonator pipe 2, the resonance function of the fourth compartment D (resonator chamber) will decrease due to the increase in the number of compartments A and B. Preferably, there are separate compartments A and B. Moreover, such a gradual decrease in the flow velocity of exhaust gas causes the end plates 11 and 12 and the partition plates 13 and 1 to
It is also effective in reducing the load on 4 and 15 and preventing the generation of vibrations and abnormal noises. The exhaust gas divided and expanded in this way is interferingly mixed in the third compartment C through the conduit 6, and the noise is further attenuated. Moreover, since no rapid turning is performed during this time, the exhaust pressure does not increase and the airflow noise does not become high. Note that the interference mixing in the third compartment C is expected to be carried out sufficiently because the exhaust gas enters the exhaust outlet pipe 3 only through the small hole 33, but preferably it is possible. It is preferable to provide as many small holes 33 as possible.

[Effect of idea]

As described above, the internal combustion engine silencer according to the present invention has the effect of preventing exhaust gas from swirling rapidly, thereby preventing an increase in exhaust pressure and air flow noise, and also because it does not expand rapidly. This has the effect of reducing pressure loss. Furthermore, since the divided exhaust gas flows are interferingly mixed, there is an effect that the noise attenuation function is not deteriorated.

Furthermore, such improved performance of the muffler has the effect of improving the flow of exhaust gas throughout the exhaust system of the internal combustion engine.

[Brief explanation of drawings]

Figure 1 is a simplified sectional view showing the basic principle of the present invention.
FIG. 2 is a cross-sectional view showing a specific structure of a muffler for an internal combustion engine according to the present invention, and FIGS. 3 and 4 are simplified cross-sectional views showing conventional examples. DESCRIPTION OF SYMBOLS 1... Outer cylinder, 2... Exhaust introduction pipe, 3... Exhaust outlet pipe, 6... Conduit, 22... Gas outlet end, 23...
...Small hole, 31...Gas inlet end, 33...Small hole,
A, B, C, D... compartment.

Claims (1)

[Scope of utility model registration request] A silencer for an internal combustion engine, comprising an outer cylinder whose both ends are closed with end plates and whose interior is divided into a plurality of compartments by a partition plate, and an exhaust inlet pipe and an exhaust outlet pipe that communicate the inside and outside of the outer cylinder. The exhaust gas introduction pipe is passed through at least one compartment and its gas outlet end is opened to the second and subsequent compartments, and a large number of small holes are bored in the portion of the exhaust gas introduction pipe that penetrates each compartment. , a conduit is provided in each partition plate defining a compartment through which an exhaust inlet pipe passes or whose gas outlet end is open, and these compartments are used as expansion chambers, and an exhaust outlet pipe is connected to the gas outlet end of the exhaust inlet pipe. Infiltrate the opening into the compartment, and
1. A silencer for an internal combustion engine, characterized in that a gas inlet end of an exhaust outlet pipe is closed, and a number of small holes are bored in the penetrated portion.