Flexible tube for exhaust pipe of automobile

Abstract

A flexible tube for an exhaust pipe of an automobile is disclosed, of which the bellows member has protrusion portions, a center portion and both end portions such that the protrusion portions have a uniform outer diameter, and the center portion has a maximum depression inner diameter which is larger than a minimum depression inner diameter of the both end portions, and the outer cover member is formed of an outer net with a network structure, wherein a depression inner diameter in the center of a bellows is larger than a depression inner diameter at the both ends such that a gap from an interlocking member increases so as to prevent the interference between the bellows and the interlocking member.

Claims

1. A flexible tube for an exhaust pipe of an automobile, comprising: a bellows member made from a metal material in the shape of a hollow cylinder having corrugations which are repetitively formed in a wave form, wherein the bellows member has protrusion portions, a center portion, and two end portions; an interlocking member positioned in the bellows member with a predetermined gap from the bellows member and having a spiral groove spirally formed on the interlocking member so as to absorb deformation; an outer member surrounding the outside of the bellows member; cap members for coupling the outer cover member such that the outer cover member is fixed to an outside of both end portions of the bellows member; and intermediate members formed in the shape of a ring, of which one end is fixed to the bellows member and the other end is fixed to the interlocking member by overlapping the interlocking member inwards, wherein the protrusion portions have a uniform outer diameter, and the center portion has a maximum depression inner diameter which is larger than a minimum depression inner diameter of both end portions, and wherein the outer cover member is formed of an outer net with a network structure.

2. The flexible tube for an exhaust pipe of an automobile according to claim 1, wherein the bellows member has a depression inner diameter which is formed such that depression portions gradually increase from the minimum depression inner diameter of both end portions to the center portion in the outward direction, and a maximum depression inner diameter which is uniformly formed in the center.

3. The flexible tube for an exhaust pipe of an automobile according to claim 1, wherein the center portion of the bellows member further includes reinforcement sections formed with low protrusion portions and high depression portions, of which each height is smaller than the protrusion portions and the depression portions which are uniformly repeated.

4. The flexible tube for an exhaust pipe of an automobile according to claim 2, wherein the minimum depression inner diameter of both end portions of the bellows member gradually increases at a uniform angle towards the maximum depression inner diameter of the center portion such that the inner diameter of the center portion is formed to be large, and the reinforcement sections is formed in the shape of a ring with the low protrusion portions and the high depression portions, of which each height is smaller than the protrusion portions and the depression portions which are uniformly repeated in the center portion.

5. The flexible tube for an exhaust pipe of an automobile according to claim 1, wherein a gap formed between the interlocking member and the bellows member is further provided with a wire mesh so as to prevent the contact of the interlocking member and the bellows member.

6. The flexible tube for an exhaust pipe of an automobile according to claim 1, wherein the outer cover member formed of the outer net is further surrounded by a braid member on the outside thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a half-sectional view showing the basic structure of a flexible tube for an exhaust pipe of an automobile according to one embodiment of the present invention.

(2) FIG. 2 is an expanded sectional view showing the structure of a bellows member according to the present invention.

(3) FIG. 3 to FIG. 5 are expanded sectional views showing flexible tubes for an exhaust pipe of an automobile according to other embodiments of the present invention.

(4) FIG. 6 is a half-sectional view showing the structure of a prior art bellows member.

(5) FIG. 7 to FIG. 10 are half-sectional views showing flexible tubes for an exhaust pipe of an automobile according to other embodiments of the present invention.

(6) FIG. 11 is an expanded sectional view of portion A of FIG. 7, and

(7) FIG. 12 is an expanded sectional view of portion B of FIG. 8.

(8) FIG. 13 is a half-sectional view showing a flexible tube for an exhaust pipe of an automobile according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(9) Hereinafter, the present invention will be described in greater detail by reference to the drawings. However, the present invention should not be construed as being limited thereto.

(10) In a flexible tube for an exhaust pipe of an automobile according to the present invention, as shown in the accompanied drawings, the depression inner diameter of the center portion of a bellows member is formed to be larger than the depression inner diameter of both end portions so as to increase a gap from an interlocking member, such that the interference between the bellows member and the interlocking member may be prevented. The depression portions of the both end portions are formed to be small so as to flexibly absorb the external force and displacement applied to the bellows member such that the flexibility and durability of the bellows member may be improved.

(11) First of all, a flexible tube 1 for an exhaust pipe according to the present invention includes a bellows member 10 formed in the shape of a hollow cylinder and having corrugations which are repetitively formed in a wave form, an interlocking member 20 positioned in the bellows member 10 with a predetermined gap from the bellows member 10, an outer cover member 30 for surrounding the outside portion of the bellows member 10, cap members 40 for fixing the outer cover member 30 to the outside portions of the both ends of the bellows member 10, and intermediate members 50 having one end fixed to the bellows member 10 and the other end fixed to the interlocking member 20 by overlapping the interlocking member 20 inwards, wherein it is important to sufficiently maintain the gap from the interlocking member 20 by forming the maximum depression inner diameter D3 of the center portion C to be larger than the minimum depression inner diameter D1 of the both end portions U.

(12) At this time, it is important that the bellows member 10 is formed such that the maximum depression inner diameter D3 of the center portion C is expanded to be larger than the minimum depression inner diameter D1 of the both end portions U so as to sufficiently maintain the gap from the interlocking member 20.

(13) To this end, referring to FIG. 2 which shows the approximate directions used in the description, the bellows member 10 is made from a metal material in the shape of a pipe, wherein the bellows member 10 is provided with repetitive corrugations in a wave form by protrusion portions 12 and depression portions 13 which are continuously formed in the lengthwise direction. Therefore, as the displacement is generated in the axial direction or in the bending direction due to the vibration or shocks, the protrusion portions 12 and the depression portions 13 which are continuously formed in the lengthwise direction serve to absorb the displacement by being elastically bent, to prevent the leakage of exhaust gas, to absorb extension and bending. The protrusion portions 12 and the depression portions 13 are restored after the displacement is absorbed and the external force is removed.

(14) Further, the interlocking member 20 is positioned in the bellows member 10 while maintaining a predetermined gap from the bellows member 10.

(15) The interlocking member 20 has a spiral groove which is spirally formed throughout the interlocking member 20 such that the damping effect is generated by the friction in the spiral groove at the time of the axial or bending displacement is generated, wherein the spiral groove mainly absorbs the deformation in the lengthwise direction and uniformly maintains the space of a path through which the exhaust gas passes, thereby serving to restrain the generation of turbulence.

(16) The outer cover member 30 surrounds the outside of the bellows member 10, wherein an outer net which is braided with a thin metal wire in a net structure is selected as for the outer cover member 30.

(17) Therefore, the bellows member 10 may be flexibly deformed with a large displacement even with respect to the displacement and tension in the compression direction. The outer cover member 30 and the both end portions of the outside of the bellows member 10 are coupled to the cap members 40 such that the cap members 40 are fixed to the bellows member 10.

(18) Meanwhile, the bellows member 10 and the interlocking member 20 are connected to each other by the intermediate member 50 which is formed in the shape of a ring.

(19) That is, in the state that the front ends of the intermediate members 50 are in accordance with the end portions of the bellows member 10 and the horizontal portions of the bellows member 10, the outer cover member 30 and the cap members 40 are mutually overlapped, the front ends of the intermediate members 50 is attached to the bellows member 10 by clamping means which have fastening function in the circumferential direction or by carrying out spot-welding on the several points thereof.

(20) Further, the other ends of the intermediate members 50 are partially overlapped by the interlocking member 20 in the state that the other ends of the intermediate members 50 are folded towards the inside of the interlocking member 20, and then the spot-welding is carried out on several points such that the bellows member 10 and the interlocking member 20 are maintained in a completely coupled state.

(21) At this time, the bellows member 10 according to the present invention has, as shown in FIG. 2, a uniform outer diameter of the protrusion portions 12, and the maximum depression inner diameter D3 of the center portion C is formed to be larger than the minimum depression inner diameter D1 of the both end portions U.

(22) That is, the bellows member 10 has the maximum depression inner diameter D3 of the center portion C which is formed to be larger than the minimum depression inner diameter D1 of the both end portions U, and the protrusion portions 12 which are continuously formed in the lengthwise direction with the same height, in the state that the minimum depression inner diameter D1 of the both end portions U is formed to be equal to or larger than the inner diameter Dt of the end portions 11.

(23) Therefore, the bellows member 10 may maintain the same gap as the conventional one between the interlocking member 20 which is positioned in the bellows member 10 and the both end portions U and a larger gap than the conventional one between the interlocking member 20 and the center portion C.

(24) If the displacement in the axial direction or the bending direction is generated to the bellows member 10 and the interlocking member 20 due to the vibration or shock, displacement is generated more seriously in the center portion C of the bellows member 10 rather than in the both end portions U. However, the center portion C according to the present invention maintains the sufficient gap such that the damage to the bellows member 10 by the interlocking member 20 may be prevented.

(25) To the contrary, a minimum gap is maintained from the interlocking member 20 to the both end portions U of the bellows member 10 at which the vibration is not serious. Therefore, the height of the protrusions of the both end portions U may be high, improving the flexibility and durability of the bellows member.

(26) Further, the bellows member 10 according to another embodiment, as shown in FIG. 3, has a depression inner diameter D2 which gradually increases from the minimum depression inner diameter D1 of the both end portions U to the center portion C, and a uniformly maximum inner diameter D3 in the center.

(27) As described above, by forming a predetermined inclination from the both end portions U of the bellows member 10 to the center portion C, the bellows member 10 may be guided with an inclination with respect to the bending displacement such that the concentration of the stress generated by a sharp change of shape may be prevented and smooth movement may be secured.

(28) In general, 5-25 is basically employed as the inclination of the inclined depression portions 13, and the number of the inclined depression portions is preferably set to be 1-3.

(29) Further, as shown in FIG. 4, the center portion C of the bellows member 10 according to another embodiment of the present invention further includes reinforcement sections S which are formed with low protrusion portions 12a and high depression portions 13a, of which each height is lower than the protrusion portions 12 and the depression portions 13 which are uniformly repeated.

(30) Furthermore, as shown in FIG. 5, the inner diameter of the depression portions 13 of the both end portions U of the bellows portion 10 gradually increases at a uniform angle towards the inner diameter of the depression portions 13 of the center portion C such that the inner diameter of the center portion C is formed to be large, and the center portion C further includes the reinforcement sections S which are formed in the shape of a ring and have the low protrusion portions 12a and the high depression portions 13a, of which each height is lower than the protrusion portions 12 and the depression portions 13 which are uniformly repeated on the center portion C.

(31) The reinforcement sections S have advantages, wherein 25 protrusions of the center portion C of the bellows member 10 may be reduced, thereby reducing the consumption of materials so as to reduce manufacturing costs.

(32) Meanwhile, as shown in FIG. 8 and FIG. 10, it is possible to further provide a wire mesh 60 to the gap which is formed between the interlocking member 20 and the bellows member 10 so as to prevent the contact of the interlocking member 20 and the bellows member 10.

(33) The wire mesh 60 is an elastic material which is formed in the shape of a tube by compressing a net structure which is braided with a thin metal wire and the wire mesh 60 is fitted in the gap so as to elastically absorb the shock resulting from the vibration of the engine or the road surface during driving as well as the bending displacement or the like.

(34) In addition, the wire mesh 60 can prevent the mutual contact of the bellows member and the interlocking member by the vibration during driving, thereby removing the sources of noise generation.

(35) Furthermore, an elastic member 70 can be preferably mounted on the outside of the outer cover member 30 as shown in FIG. 9 and FIG. 10.

(36) The elastic member 70 is a spring member which is basically formed in the shape of a ring for surrounding the bellows member 10 and the outer cover member 30, wherein the elastic member 70 is formed in the shape of undulating so as to be bent and to obtain tension.

(37) The elastic member 70 generates fastening force towards the bellows member 10.

(38) At this time, the radial diameter of the corrugations decreases in the approximately middle portion of the bellows member 10 so as to form a securing groove 17, and the elastic member 70 is received in the securing groove 17 and prevented from escaping.

(39) Meanwhile, it is preferable to mount another braid member 80 on the outside of the outer cover member 30 which is made from an outer net.

(40) The braid member 80 is braided with a thin metal wire and further surrounds the outside of the outer cover member 30 for the flexible deformation by the large displacement with respect to the displacement and tension in the compression direction.

(41) The braid member 80 is coupled to the cap members 40 at the both end portions of the outside thereof as the outer cover member 30 and the mainly fixed with the bellows member 10 by clamping FIG. 13.

(42) Having described our invention as related to the present embodiments, it is our intention that the invention not be limited by any of the embodiments and drawings of the description, and it is apparent to those skilled in the art that various changes and modifications of the present invention may be made without departing the spirit and scope of the invention.

(43) TABLE-US-00001 Brief Explanation of Reference Signs 101 - flexible tube for an exhaust pipe 10 - bellows member 12 - protrusion portions 12a - low protrusion portions 13 - depression portions 13a - high depression portions 20 - interlocking member 30 - outer cover member 40 - cap member 50 - intermediate member 60 - wire mesh 70 - elastic member 80 - braid member C: center portion U: both end portions S: reinforcement section D1 - minimum depression inner diameter D3 - maximum depression inner diameter