US20060005536A1

US20060005536A1 - Exhaust decoupler

Info

Publication number: US20060005536A1
Application number: US10/998,256
Authority: US
Inventors: Jin-Kwon An
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-07-06
Filing date: 2004-11-26
Publication date: 2006-01-12
Also published as: KR100537959B1

Abstract

A decoupler of an exhaust pipe having spaces for absorbing various stresses caused by impact, vibration, heat distortion, or the like. The decoupler includes a corrugated bellows repeatedly formed with corrugations, a sleeve for protecting the bellows against exhaust gas, an outer cap for enclosing the outer side of one end of the bellows, an inner cap for enclosing the outside of the bellows, and wire mesh buffering members installed in spaces defined by the inner cap and the outer cap, to support the inner cap and the outer cap and to maintain air tightness between the inner cap and the outer cap. The outer cap has bending portions formed at the ends thereof, so as to maintain a gap between the outer surface of the inner cap and the end of the outer cap. The surfaces of the buffering members are closely attached to the outer surface of the inner cap, upper inside surfaces of the bending portions and lateral inner surfaces of the bending portions, so as to define buffering spaces between the buffering members and the bending portions. Thus, the deformation of the decoupler can be prevented so as to reduce wearing of the decoupler and frictional noise and to enhance the durability of the decoupler.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a decoupler of an exhaust pipe, and more particularly to a decoupler including a bellows having one end coupled between a sleeve and an outer cap, the other end coupled to the inner circumferential surface of an inner cap, side corrugations connected to the outer cap and the inner cap and smaller than a middle corrugation so as to form a rounded overall shape of the bellows, the inner cap formed with curved surfaces corresponding to the overall shape of the bellows, the outer cap formed with bending portions so as to have corners, buffering members supported by the curved surfaces of the inner cap and the inner surfaces of the bending portions of the outer cap, and spaces formed in the insides of the bending portions, so that various stresses due to impact, vibration, and heat distortion, are absorbed by the spaces, and the deformation of the decoupler can be prevented.
2. Description of the Related Art
Generally, a vehicle engine is connected with an exhaust pipe having a muffler to exhaust the exhaust gas. At the connection point of the exhaust pipe is installed a decoupler, as a connecting device. The decoupler prevents vibration from being transmitted to the vehicle body by absorbing vibration caused by explosions in the engine, and prevents external shock from being transmitted to the engine. Moreover, the decoupler absorbs displacement caused by vibration and impact load and buffers heat distortion. The decoupler includes a bellows, a sleeve, an outer cap for enclosing the outside of the bellows, and an inner cap. The bellows has a plurality of corrugations and is disposed between an engine and the exhaust pipe coupled to the vehicle body. The sleeve is inserted into one side of the bellows to be connected to the engine. The inner cap is disposed between the bellows and the outer cap, and is spaced from the outer cap.
The decoupler constructed as described above prevents vibration from being transmitted to the vehicle body by absorbing the vibration generated from the engine, and prevents vibration generated from the vehicle body due to uneven road conditions from being transmitted to the engine, so as to protect the engine. The decoupler must absorb the vibration and displacement generated at the exhaust system of the vehicle. Stress and displacement absorbed by the decoupler may include various stresses, such as tensile stress, compressive stress, bending stress, and torsional stress, and excessive displacement generated in every direction.
The decoupler includes a bellows disposed between rims and a buffering member, for enclosing the outer surface of the engine. The rims and the buffering members absorb vibration of the engine, the expansion displacement in the longitudinal direction generated by impact when in motion, and bending displacement when the central axes of exhaust connecting devices are deviated from each other. Since the inner cap coupled to the engine is separated from the outer cap coupled to the exhaust pipe, the buffering member and the bellows are formed with respective elastic portions. The elastic portions are disposed between the inner cap and the outer cap and support the inner cap and the outer cap, so as to absorb the deformation, vibration, and impact stress.
Therefore, in the decoupler, it is very important that the bellows and a wire mesh, of which one end is connected to the engine and the other end is connected to the exhaust pipe, allow the exhaust gas to flow through a central part thereof, and are expanded to absorb the impact and the deformation generated between the engine and the exhaust pipe.
To overcome the above-described disadvantage, extensive research and a variety of approaches have been proposed. A conventional decoupler for connecting an exhaust pipe to an engine, as shown in FIG. 1, includes a sleeve 20 coupled to the engine 200, a bellows coupled to an outer surface of one end of the sleeve 20 which is coupled to the engine 200, an outer cap 20 installed outside the bellows 10, an inner cap 40 disposed between the outer cap 30 and the bellows 30 and integrally connected to the other end of the bellows 10, in which the exhaust pipe 300 is coupled, and supporting wire meshes 500 filled in a space on one end 31 of the outer cap 30, defined by the outer cap 30 and the inner cap 40, and a space on one end 41 of the inner cap 40, defined by the outer cap 30 and the inner cap 40.
However, the above-mentioned decoupler does not sufficiently manage impact, vibration, and heat distortion, and is not flexible because of the deformation of the inner cap 40 and/or the outer cap 30, so that the decoupler cannot fulfill its designed functions.
The development of the above-described decoupler is shown in FIG. 2. As shown in FIG. 2, the development of the decoupler includes a sleeve 20 coupled to the engine 200, a bellows coupled to an outer surface of one end of the sleeve 20 which is coupled to the engine 200, an outer cap 20 installed outside the bellows 10, an inner cap 40 disposed between the outer cap 30 and the bellows 30 and integrally connected to the other end of the bellows 10, to which the exhaust pipe 300 is coupled, supporting wire meshes 500 filled in a space on one end of the outer cap 30, defined by the outer cap 30 and the inner cap 40, and a space on one end of the inner cap 40, defined by the outer cap 30 and the inner cap 40, and shock-absorbing wire meshes 600 filled the outside spaces of the supporting wire meshes 500, defined between the supporting wire meshes 500. However, the above-mentioned decoupler, does not sufficiently manage impact, vibration, and heat distortion, and is not flexible because of the deformation of the inner cap 40 and/or the outer cap 30, so that the decoupler cannot fulfill its designed functions.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a decoupler including a bellows having one end coupled between a sleeve and an outer cap, the other end coupled to the inner circumferential surface of an inner cap, side corrugations connected to the outer cap and the inner cap and smaller than a middle corrugation, to form a rounded whole shape of the bellows, the inner cap formed with curved surfaces corresponding to the rounded overall shape of the bellows, the outer cap formed with bending portions to have corners, buffering members supported by the curved surfaces of the inner cap and the inner surfaces of the bending portions of the outer cap, and spaces formed in the insides of the bending portions, so that various stresses due to impact, vibration, and heat distortion, are absorbed by the spaces.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other objects and advantages of the present invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a cross-sectional view of a conventional decoupler;
FIG. 2 is a cross-sectional view of another conventional decoupler;
FIG. 3 is a partial cross-sectional view of a decoupler according to the present invention; and
FIG. 4 is a schematic view illustrating installation of the decoupler according to the present invention and the conventional decoupler to the vehicle engine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a decoupler according to the present invention will be described in connection with the accompanying drawings.
As shown in FIG. 3, the decoupler includes a corrugated bellows 10, a sleeve 20, an outer cap 30, an inner cap 40, and buffering members 50 made of wire meshes.
The corrugated bellows 10 is formed with repeated wave-formed corrugations. The sleeve 20 is inserted into the bellows 10 and protects the bellows 10 against exhaust gas. The sleeve 20 has one end with a large diameter fixed to an inner surface of one end of the bellows 10, and a free end of a small diameter spaced apart from an inner surface of the bellows 10.
The outer cap 30 encloses the outer side of one end of the bellows 10 where the sleeve 20 is coupled. The inner cap 40 is installed between the outer cap 30 and the bellows 10, and is also coupled to the other end of the bellows 10, so as to enclose the outside of the bellows 10.
The buffering members 50 are installed in a space on one end of the inner cap 40, defined between an outer surface of the inner cap 40 and an inner surface of the outer cap 30, and in a space on one end of the outer cap 30, defined between the outer surface of the inner cap 40 and the inner surface the outer cap 30, so as to support the inner cap 40 and the outer cap 30 and to maintain air tightness between the inner cap 40 and the outer cap 30.
The corrugations 11 formed at sides of the bellows 10 are smaller than corrugations 12 formed at a middle portion of the bellows 10. Thus the bellows forms a gentle curved line R.
The inner cap 40 has curved surfaces 45 respectively formed at a leading end and the other end thereof, so that the curved surfaces of the inner cap 40 correspond to the curved line formed by the corrugations 11 and 12 of the bellows 10. The inner cap 40 encloses surfaces of the corrugations 11 and 12 to be adjacent to the surfaces of the corrugations 11 and 12 of the bellows 10.
However, it is very important that the inner cap 40 does not interfere with the bellows 10.
The outer cap 30 has L-shaped cross-sectional bending portions 35 respectively formed at the end 31 of the outer cap 30 and at a portion corresponding to the end 41 of the inner cap 40, and the end 31 of the outer cap 30 has an inner diameter sufficient to be spaced apart from an outer circumference of the inner cap 40, so as to maintain a gap between the outer surface of the inner cap 40 and the end of the outer cap 30. Thus, the outer cap 30 properly manages the tensile stress and the bending stress.
The lower surfaces 51 of the buffering members 50 are closely attached to an outer curved surface of the inner cap 40, upper surfaces 52 of the buffering members 50 are closely attached to upper inside surfaces of the bending portions 35 and lateral surfaces 53 of the buffering members 50 are closely attached to lateral inner surfaces of the bending portions, so as to define buffering spaces 60 between the buffering members 50 and the bending portions 35.
Reference numeral 200 indicates the vehicle engine, and reference numeral 300 indicates the exhaust pipe of the vehicle having the muffler.
When the decoupler according to the present invention will be used by being installed to the vehicle engine 200, as shown in FIG. 4, there may appear various situations caused by road conditions in the traveling and heat distortion due to the heat of the exhaust gas generated from the engine 200. Here, the effect of the decoupler according to the present invention will be described by using some situations as examples.
The sleeve 20 having a free end is the first to absorb the heat generated from the exhaust gas, the rest of the heat is transmitted to the bellows 10. The corrugations of the bellows 10 absorb stress caused by the heat as much as possible. Moreover, the bellows 10 absorbs the vibration due to the explorations in the engine 200 so as to prevent the vibration from being transmitted to the exhaust pipe 300.
In this state, when various stresses, such as vibration, bending stress, tensile stress, and the like, generated from wheels of the vehicle when in motion are transmitted to the decoupler via the exhaust pipe 300, the bending stress and the torsional stress are absorbed by the deformation and restoration of the bellows 10 by which the wire mesh buffering members 50, disposed between the outer cap 30 and the inner cap 40, are slid over the outer surface of the inner cap 40. The tensile stress and the impact stress are absorbed in a manner that the wire mesh buffering members 50, disposed between the inner cap 40 and the outer cap 30, are deformed and restored in the spaces 60 defined between the outer cap 30 and the bending portions 35.
As described above, the bellows 10 is installed such that one end of the bellows 10 is coupled between the sleeve 20 and the outer cap 30 and the other end of the bellows 10 is coupled to the inner circumferential surface of the inner cap 40. The bellows 10 has the side corrugations 11, connected to the outer cap 30 and the inner cap 40, smaller than the middle corrugation 12, so as to form a rounded overall shape. The inner cap 40 is formed with the curved surfaces 45 corresponding to the overall shape of the bellows 10. The outer cap 30 is formed with the bending portions 35 so as to have corners. The buffering members 50 are supported by the curved surfaces 45 of the inner cap 40 and the inner surfaces of the bending portions 35 of the outer cap 30. The spaces 60 are formed in the insides of the bending portions 35, so that various stresses due to impact, vibration, and heat distortion, are absorbed in the spaces 60. Thus, the deformation of the decoupler can be prevented so as to reduce wearing of the decoupler and frictional noise and to enhance the durability of the decoupler.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. An exhaust decoupler for an engine comprising:

a corrugated bellows formed with wave-formed corrugation repeatedly;

a sleeve, inserted into the bellows, for protecting the bellows against exhaust gas, having one end with a large diameter fixed to an inner surface of one end of the bellows, and a free end of a small diameter spaced apart from an inner surface of the bellows;

an outer cap for enclosing the outer side of one end of the bellows where the sleeve is coupled;

an inner cap, installed between the outer cap and the bellows, and coupled to the other end of the bellows, for enclosing the outside of the bellows; and

wire mesh buffering members, installed in a space on one end of the inner cap, defined between an outer surface of the inner cap and an inner surface of the outer cap, and in a space on one end of the outer cap, defined between the outer surface of the inner cap and the inner surface of the outer cap, for supporting the inner cap and the outer cap and maintaining air tightness between the inner cap and the outer cap, wherein

corrugations formed at sides of the bellows are smaller than corrugations formed at a middle portion of the bellows, so as to form a gentle-curved-line-shaped bellows,

the outer cap has L-shaped cross-sectional bending portions respectively formed at the end of outer cap and a portion corresponding to the end of the inner cap, and the end of the outer cap has an inner diameter sufficient to be spaced apart from an outer diameter of the inner cap, so as to maintain a gap between the outer surface of the inner cap and the end of the outer cap, and

lower surfaces of the buffering members are closely attached to an outer curved surface of the inner cap, upper surfaces of the buffering members are closely attached to upper inside surfaces of the bending portions and lateral surfaces of the buffering members are closely attached to lateral inner surfaces of the bending portions, so as to define buffering spaces between the buffering members and the bending portions.