JPH078518U - silencer - Google Patents

Abstract

(57) [Abstract] [Purpose] The purpose is to reduce noise emitted from the end plates due to resonance with exhaust noise and improve quietness in the passenger compartment. [Structure] The end plate that constitutes the silencer is formed into a dome shape that bulges outward, and a reinforcing plate is joined and fixed so as to pull in the amplitude direction between the inner edges of the end plate. By making the end plate a dome shape, resonance of the end plate itself can be prevented and the resulting vibration at the joint between the end plate and the outer shell can be eliminated by the reinforcing plate, which is the main cause of exhaust noise. It is possible to reduce the radiated sound of the end plate, which is a cause, to reduce the size of the silencer and to reduce the exhaust noise as a whole, and to improve the quietness in the passenger compartment.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement in the structure of a silencer mounted on a vehicle's internal combustion engine exhaust system for noise reduction.

[0002]

[Prior art]

 BACKGROUND OF THE INVENTIONSilencers that have been conventionally installed in the exhaust system of a vehicle internal combustion engine for the purpose of noise reduction are mainly for attenuating the exhaust sound of the exhaust sound and the radiated sound generated by the exhaust system of the internal combustion engine. It is required to increase the silencer size as well as to reduce noise, but it is required to increase the size of the silencer. However, since the rigidity of the outer shell and end plate that make up the silencer is reduced, the radiation sound generated by the silencer itself tends to increase.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned conventional one, the size of the silencer is increased, and at the same time, the weight of the vehicle is reduced, so that the rigidity of the outer shell and the end plate that constitute the silencer is reduced, and the radiation noise generated by the silencer itself increases. In this case, measures are taken to improve the rigidity of the end plate that significantly affects the generation of radiated sound, for example, by providing a bead on the outer surface of the end plate, and on the inner surface of the end plate. Although a reinforcing plate or a reinforcing rib is arranged in the radial direction of the end plate (Actual No. 59-81728), there is a bead on the surface of the end plate. Alternatively, by disposing a reinforcing plate or reinforcing rib on the inner surface of the end plate as in Japanese Utility Model Laid-Open No. Sho 59-81728, Although the rigidity of the body is improved, most of the radiated sound generated by the end plate is caused by resonance with the exhaust sound, and there are various input frequencies to the end plate due to this exhaust sound up to 8 kHz. , It is difficult to shift all resonance frequencies including these various frequencies to 8kHz or higher, so improving the rigidity of the silencer end plate does not lead to a reduction in the radiation noise of the silencer end plate. .

Therefore, the present invention is intended to improve the drawbacks of the above-described conventional ones, and in a silencer that is increased in size for the purpose of reducing exhaust noise, an end plate of the silencer, which is a main cause of noise together with exhaust noise, is generated. It is intended to reduce the radiated sound.

[0005]

[Means for Solving the Problems]

 Therefore, in a silencer composed of a cylindrical outer shell having an elliptical cross section and end plates formed by closing both open ends of the outer shell, an end plate formed by closing the opening of the outer shell. Has a dome shape that bulges outward, and a reinforcing plate is joined and fixed between the inner edges of the end plate so as to pull in the amplitude direction.

[0006]

[Action]

 Since the above-mentioned configuration is provided, the end plate formed by closing the opening of the outer shell has a dome shape that bulges outward, and the end plate is pulled in the amplitude direction between the inner edges. When the reinforcing plate is joined and fixed, the end plate that resonates due to the exhaust sound generated from the exhaust system of the internal combustion engine has a shape that bulges outward, so that the end play due to the exhaust sound as in the past From the surface vibration of the end plate, only the resonance at the joint between the outer shell and the end plate can be made, and between the inner edges of the end plate that is bulged outward. Since the reinforcing plate is joined so as to pull it in the amplitude direction, it is possible to suppress resonance at the joint between the outer shell and the end plate. Silencers, in particular to reduce the generated sound radiated end plate itself constituting the silencer.

[0007]

Embodiments The invention will be further described with reference to the embodiments shown in the drawings. (1) is a silencer comprising an embodiment of the present invention. This silencer (1) has a cylindrical outer shell (2) having an elliptical cross section and an opening of the outer shell (2). The exhaust gas of the internal combustion engine, which is composed of end plates (3) with both ends closed, is introduced into the silencer (1) through an intake pipe (7) that penetrates the end plates (3), , The pressure is lowered by rapidly expanding the exhaust, or a resonator is provided inside the silencer (1) and the resonance frequency of the resonator attenuates the sound wave of the same frequency in the exhaust sound, or the silencer ( 1) By providing bypass pipes with different lengths inside, the wavelengths of the sound waves in the exhaust sound are shifted and the silencer (1 To the silencing of the exhaust gas introduced through the internal to the suction pipe (7) is made to emit to the outside from the exhaust pipe (8).

Then, the end plate (3) formed by closing the opening of the outer shell (2) having an elliptical cross-section that constitutes the silencer (1) is outwardly bulged and The reinforcing plate (5) is stretched across the inner edge (4) of the end plate (3) in the amplitude direction, for example, in the short axis direction of the end plate (3) which is elliptical in FIG. ) Is joined and fixed.

Since the present invention has the above-mentioned structure, the end plate (3) which closes the opening of the outer shell (2) is made to bulge outward and the end plate (3) is formed. The end plate (3) that resonates due to the exhaust sound generated from the exhaust system of the internal combustion engine is fixed by joining and fixing the reinforcing plate (5) between the inner edges (4) of the engine so as to pull it in the amplitude direction. Since it has a shape that bulges outward, the resonance of the end plate (3) due to exhaust noise as in the past, and the resonance due to the surface vibration of the end plate (3) change from the outer shell (2). Between the end edges (4) on the inside of the end plate (3), which can only resonate at the joint (6) between the end plate (3) and the end plate (3). In the amplitude direction Since the reinforcing plate (5) is joined so as to pull it, the resonance at the joining portion (6) between the outer shell (2) and the end plate (3) is joined so as to pull in the amplitude direction. Since it can be suppressed by the fixed reinforcing plate (5), it is possible to reduce the radiated sound generated by the silencer (1), particularly the end plate (3) itself constituting the silencer (1), Furthermore, in combination with the reduction of exhaust noise accompanying the increase in size of the silencer (1), noise of the exhaust system of the internal combustion engine can be reliably reduced, and quietness in the vehicle interior can be enhanced.

The end plate (3) formed by closing the opening of the outer shell (2) has an outwardly bulging shape, and the inside edge (4) of the end plate (3) is closed. The reinforcing plate (5), which is joined and fixed to the end plate (3) by pulling it in the amplitude direction, has a space with respect to the end plate (3), but also adheres to the surface of the end plate (3) Even if they are joined and fixed, the radiated sound generated by the end plate (3) due to resonance with exhaust sound can be sufficiently reduced.

Therefore, when the end plate (3) is simply formed into a dome shape, or when the end plate (3) is formed into a dome shape, the end plate (3) is stretched in the amplitude direction between the end edges (4). When the noise of the silencer (1), which is an embodiment of the present invention in which the reinforcing plate (5) is joined as described above, is measured, the end plate (3) constituting the silencer (1) is simply dome-shaped. In contrast to the case of 110.5 dB, in the example of the present invention, it was lowered to 73.5 dB, and the effect was remarkably recognized.

[0012]

[Effect of device]

 As described above, the end plate that constitutes the silencer and closes the opening of the outer shell that has an elliptical cross section has a dome shape that bulges outward, and between the inner edges of the end plate, By joining and fixing the reinforcing plate so as to pull it in the amplitude direction, it is possible to reduce the radiated sound caused by resonance with the exhaust sound, so the weight reduction required with the increase in size of the silencer is achieved. The silencer itself has an excellent effect that the exhaust noise is sufficiently reduced even if the exhaust noise is increased due to the decrease in rigidity of the silencer, and the quietness in the vehicle interior is improved.

[Brief description of drawings]

FIG. 1 is a front view of a silencer according to an embodiment of the present invention.

FIG. 2 is a front view of an end plate that constitutes a silencer according to an embodiment of the present invention.

3 is a cross-sectional view taken along the line AA in FIG.

FIG. 4 is a sectional view taken along line BB in FIG.

FIG. 5 is a cross-sectional view of an end plate according to another embodiment of the present invention.

[Explanation of symbols]

 1 Silencer 2 Outer Shell 3 End Plate 4 End Edge (of End Plate) 5 Reinforcement Plate 6 Joint 7 Intake Pipe 8 Exhaust Pipe

Claims (1)

[Scope of utility model registration request] 1. A silencer comprising a cylindrical outer shell having an elliptical cross section and end plates formed by closing both open ends of the outer shell, wherein an end formed by closing the opening of the outer shell. A silencer in which a plate is formed into a dome shape that bulges outward, and a reinforcing plate is joined and fixed so as to be pulled between the inner edges of the end plate in the amplitude direction.