JPH0622521U - Exhaust system for automobile engine - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention relates to an exhaust system of an automobile engine, particularly an exhaust system equipped with a resonance type muffler, and is capable of exhibiting a good muffling effect by the resonance type muffler, and an exhaust having excellent sound deadening performance. The purpose is to provide a device. In an exhaust system for an automobile engine having a resonance type muffler 3 in addition to a main muffler 2, the resonance type muffler 3 is arranged close to a downstream side of the main muffler 2. .

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an exhaust system for an automobile engine, and more particularly to an exhaust system provided with a resonance type muffler in addition to a main muffler.

[0002]

[Prior art]

 Conventionally, in the engine exhaust system as described above, there is known an exhaust system provided with a resonance type muffler in addition to the main muffler. FIG. 5 shows an example of such an arrangement. The main muffler 2 is arranged near the downstream end of the exhaust system 1 of the engine, and the resonance muffler 3 is arranged at a position upstream from the main muffler 2. is there. In the figure, 4 is an exhaust pipe and 5 is a catalyzer.

In the resonance type muffler 3, conventionally, for example, as shown in FIG. 6, an outer cylinder 31 is attached by welding or the like so as to cover the periphery of the exhaust pipe 4, and the space between the outer cylinder 31 and the exhaust pipe 4 is attached. Is defined as a resonance chamber 30, and a hole 32 for communicating the resonance chamber 30 with the inside of the exhaust pipe 4 is formed in the exhaust pipe 4, and a member 33 having a substantially semicircular cross section is formed so as to cover the hole 32. A so-called throat portion for the resonance chamber 30 is formed by arranging the exhaust pipe 4 on the outer peripheral surface thereof and welding the contact portion with the exhaust pipe 4 over the entire length by welding.

[0004]

[Problems to be solved by the device]

 However, in the case where the resonance type muffler 3 is provided on the upstream side of the main muffler 2 as in the above-mentioned conventional, the temperature and flow velocity of the exhaust gas from the engine fluctuate greatly, and the frequency band of the exhaust sound is wide and unstable. Therefore, there is a problem that the sound deadening effect of the resonance type muffler 3 cannot always be sufficiently exhibited. The present invention has been proposed in view of the above problems, and it is an object of the present invention to solve the above problems in an exhaust system for a vehicle engine equipped with a resonance type muffler.

[0005]

In order to achieve the above object, an exhaust system for an automobile engine according to the present invention has the following configuration. That is, in an exhaust system for an automobile engine equipped with a resonance type muffler in addition to the main muffler, the resonance type muffler is arranged close to the downstream side of the main muffler.

[0006]

[Action]

 By placing the resonance type muffler close to the downstream side of the main muffler as described above, the exhaust gas from the engine is guided to the resonance type muffler after passing through the main muffler, and the temperature of the exhaust gas passes through the main muffler. Since the flow velocity is stable and fluctuations in the frequency band of the exhaust sound are reduced, it is possible to effectively exhibit the silencing effect of the resonance muffler 3.

[0007]

【Example】

 Hereinafter, an exhaust system for an engine according to the present invention will be described in detail with reference to an embodiment shown in the drawings. FIG. 1 is a side view showing an embodiment of an exhaust system for an engine according to the present invention, and FIG. 2 is a vertical cross-sectional view of a resonance type muffler. Members having the same functions as those of the conventional example are designated by the same reference numerals. And explain.

In the illustrated exhaust system, a main muffler 2 is provided on the downstream side of the catalyzer 5 provided on the upstream side of the exhaust system 1 so as to be in close proximity thereto, and a resonance type muffler 3 is provided on the downstream side of the main muffler 2. It was made to be provided. Reference numeral 6 in the figure denotes a sub muffler provided on the downstream side of the exhaust system 1, which is provided if necessary.

Although the internal structure of the resonance type muffler 3 described above is appropriate, FIG. 2 shows the throat portion on the peripheral surface of the exhaust pipe 4 in the resonance chamber 30 provided around the exhaust pipe 4 as in the conventional example. The thin tube 34 constituting the above is arranged, and the thin tube 34 and the hole 32 formed in the exhaust pipe 4 are made to communicate with each other through the connecting member 35. The connecting member 35 is fixed to the outer peripheral surface of the exhaust pipe 4 by welding, and the thin tube 34 is airtightly fitted and fixed to the connecting member 35.

When at least a part of the throat is formed by the thin tube 34 as described above, the semi-arcuate member 33 is arranged on the outer peripheral surface of the exhaust pipe 4 as in the conventional case, and the contact portion with the exhaust pipe 4 is arranged. Compared to the case of welding over the entire length, there are fewer welding points, there are advantages that distortion, deformation, rust, etc. due to welding are reduced, and that it can be manufactured easily and cheaply.

The thin tube 34 may be simply press-fitted into the connecting member 35, but if necessary, may be fixed at least partially by welding or the like. If necessary, the thin tube 34 may be fixed to the exhaust pipe 4 by spot welding or the like. Further, for example, as shown in FIG. 3, the end portion of the thin pipe 34 as described above is formed into a shape that can be airtightly adhered to the outer peripheral surface of the exhaust pipe 4 by press working or the like so that the exhaust pipe 4 around the hole 32 can be formed. It is also possible to directly attach it to the outer peripheral surface by welding W or the like, which makes it possible to further simplify the structure of the throat.

Further, as in the embodiment shown in FIGS. 2 and 3, when the thin tube 34 has a contact surface with the exhaust pipe 4 formed into a curved surface having substantially the same curvature as the outer peripheral surface of the exhaust pipe 4, It is possible to improve the adhesion and airtightness with the exhaust pipe 4. However, a circular cross section or any other shape may be used. When the diameter of the exhaust pipe 4 in the resonance muffler 3 is reduced as in the embodiment of FIGS. 2 and 3, the volume of the resonance chamber 30 and the diameter of the resonance chamber 30 are reduced even when the outer diameter of the outer cylinder 31 is restricted. The diameter of 34 and the clearance with the outer cylinder 31 can be sufficiently secured, and the degree of freedom in design can be increased. However, it is needless to say that the diameter of the exhaust pipe 4 in the resonance muffler 3 does not necessarily have to be small as described above.

Further, for example, as shown in FIG. 4, a cylinder body 36 having a larger diameter than that is arranged on the outer circumference of the exhaust pipe 4, and one end of the cylinder body 36 is formed to have a small diameter so that the outer peripheral surface of the exhaust pipe 4 is formed. It is also possible to make the annular space between the tubular body 35 and the exhaust pipe 4 a throat by fixing with welding W or the like, and there is the same advantage as above. In this case, a plurality of holes 32 for communicating the annular space between the tubular body 35 and the exhaust pipe 4 with the inside of the exhaust pipe 4 may be provided, for example, at substantially equal intervals in the circumferential direction of the exhaust pipe 4. .

[0014]

[Effect of device]

 As described above, according to the present invention, in the exhaust system for an automobile engine including the resonance type muffler 3 in addition to the main muffler 2, the resonance type muffler 3 is arranged close to the downstream side of the main muffler 2. Therefore, the exhaust gas from the engine passes through the main muffler and is then guided to the resonance type muffler.By passing through the main muffler, the temperature and flow velocity of the exhaust gas are stabilized, and fluctuations in the frequency band of the exhaust sound are reduced. Since the muffler 3 can effectively exhibit the sound deadening effect, it is possible to provide an exhaust system having a good sound deadening property by utilizing the advantages of the resonance muffler.

[0015]

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of an exhaust system for an automobile engine according to the present invention.

FIG. 2A is a vertical cross-sectional view showing an example of the internal structure of a resonance type muffler. (B) is the bb sectional view taken on the line in (a).

FIG. 3A is a vertical cross-sectional view showing another example of the internal structure of a resonance-type muffler. (B) is the bb sectional view taken on the line in (a).

FIG. 4A is a vertical cross-sectional view showing still another example of the internal structure of the resonance type muffler. (B) is the bb sectional view taken on the line in (a).

FIG. 5 is a side view showing an example of a conventional engine exhaust system.

FIG. 6A is a vertical cross-sectional view showing an example of the internal structure of a conventional resonance muffler. (B) is the bb sectional view taken on the line in (a).

[Explanation of symbols]

 1 Exhaust system 2 Main muffler 3 Resonance type muffler 4 Exhaust pipe 5 Catalyzer 6 Sub muffler

Claims (1)

[Scope of utility model registration request] 1. An exhaust system for an automobile engine, comprising a resonance type muffler in addition to a main muffler, wherein the resonance type muffler is arranged close to a downstream side of the main muffler. Exhaust system of the engine.