KR101990481B1 - Flexible double pipe and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a flexible double pipe and a manufacturing method thereof, wherein the flexible double pipe comprises: an outer pipe to which a spiral coil is applied; an inner tube disposed inside the outer tube; a pair of flanges connected to both ends of the inner tube and the outer tube; and a sealing device installed between both ends of the flanges, the inner tube, and the outer tube, and sealing a space between the outer tube and the flanges to prevent an air leakage. Therefore, the sealing device is applied between the outer tube and the flanges to seal a space between both ends of the outer tube and a coupling portion of the flanges for airtightness to prevent an air leakage.

Description

[0001] FLEXIBLE DOUBLE PIPE AND MANUFACTURING METHOD THEREOF [0002]

The present invention relates to a flexible double tube and a manufacturing method thereof, and more particularly, to a flexible double tube having a sealing structure to prevent leakage at a joint portion with a flange coupled to both ends of a double tube, and a manufacturing method thereof.

In general, the flexible hose is also referred to as a flexible pipe or a flexible tube. The flexible hose can be manufactured by bending a band-shaped metal plate material having a strip shape. The flexible hose can be divided into a bellows type and an interlock type .

These flexible hoses are mainly used as exhaust pipes for automobiles regardless of the molding method. They can be used for conveying grain such as grains, etc., and can be used where curvilinear arrangement is possible or when the elasticity of the connection part is required. And it is used variously according to the purpose of.

Especially, when the flexible hose is used as an automobile exhaust pipe, it is applied to an exhaust pipe connected to the engine. It is used as a connecting body connecting exhaust communication and exhaust communication, and the vibration of the engine is transmitted to the vehicle body through the exhaust pipe It is one of the important parts that function to block the transmission.

In other words, the interlock hose is manufactured by spirally winding the metal strips together, and it is a structure that can withstand the internal pressure by inserting or coating high quality packing on the mating part.

The applicant of the present invention has filed a patent application for interlock hose and bellows device technology disclosed in the following patent documents 1 and 2.

In recent years, a flexible hose having a double pipe structure has been used in order to prevent leakage to the outside from an outer pipe even when leakage occurs due to cracking or corrosion in an inner pipe.

The following patent document 3 discloses a corrugated pipe technology to which a helical coil is applied.

For example, FIG. 1 is an exemplary view of a double tube to which a spiral coil according to the prior art is applied, and FIG. 2 is an exemplary view of a double tube with the ring shown in FIG. 1 removed.

As shown in Fig. 1, a double tube 1 to which a helical coil according to the related art is applied is formed by spirally winding a cover of an outer tube 2 disposed outside of an inner tube (not shown) And the spiral coil 5 is provided on the inner surfaces of the leading cover member 4 and the trailing cover member 3 so as to maintain the cylindrical shape.

A plurality of, for example, three coils 5 are piled up in the process of coupling the ring 7 connected to the flange 6 to both ends of the double tube 1 to which the helical coil according to the related art is applied, A plurality of, for example, three ring supports 8 are welded and supported on the outer periphery.

Korean Patent Registration No. 10-1277704 (issued on June 20, 2013) Korean Patent Publication No. 10-2015-0132824 (published on November 26, 2015) Korean Patent Registration No. 10-0846950 (issued on July 17, 2008)

However, as shown in FIG. 2, the dual tube 1 to which the helical coil according to the prior art is applied is formed in a spiral shape so that the coil 5 is wound in the process of coupling the ring 7 at both ends, A discontinuous section P is generated at the end of the discontinuity section P.

As a result, fatigue due to engine vibration and displacement is concentrated in a part of the motion of the cover, resulting in cracking due to load due to fatigue rather than influence of temperature. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a flexible double tube capable of preventing leakage due to a discontinuous section occurring at both ends of a double tube to which a helical coil is applied and a method of manufacturing the same.

Another object of the present invention is to provide a flexible double tube which is hermetically sealed between a ring and a discontinuous surface which are coupled to both ends of a dual tube, and a method of manufacturing the same.

In order to achieve the above object, the flexible double tube according to the present invention comprises an outer tube to which a helical coil is applied, an inner tube disposed inside the outer tube, a pair of inner tubes connected to both ends of the inner tube and the outer tube, And a sealing device provided between the pair of flanges and both ends of the inner tube and the outer tube and sealing the outer tube and the flange to prevent leakage through the space between the outer tube and the flange.

According to another aspect of the present invention, there is provided a method of manufacturing a flexible double tube, comprising the steps of: (a) fabricating a sealing device using a pair of ring members; (b) (C) forming an outer tube by inserting a coil in a spiral shape along an overlapping portion of the first interlocking portion and the second interlocking portion, And a pair of flanges at both ends of the inner tube and the outer tube to manufacture a double tube by heating both ends of the double tube to connect the pair of flanges to both ends of the inner tube and the outer tube And sealing to prevent leakage through a space between the outer tube and the flange, wherein a space between the pair of ring members is expanded and vaporized by heating And a pressure space is formed so that the space between both ends of the outer tube and the flange is sealed to seal the oil.

As described above, according to the flexible double pipe and the method of manufacturing the same according to the present invention, a sealing device is applied between the outer pipe and the flange, thereby sealing the space between the both ends of the outer pipe and the joint portion of the flange.

Particularly, according to the present invention, by forming the pressure space by expanding and vaporizing the oil by heating the sealing device in the state where oil is injected between the pair of ring members constituting the sealing device, It is possible to obtain an effect that leakage can be prevented by completely sealing the section and airtight.

1 shows an example of a double tube to which a helical coil according to the prior art is applied,
Fig. 2 is an illustration of an example of a double tube in which the ring shown in Fig.
3 is a perspective view of a flexible double tube according to a preferred embodiment of the present invention,
4 is a partially enlarged cross-sectional view of the double tube shown in Fig. 3,
Fig. 5 is a partially exploded view of the double tube shown in Fig. 3,
FIG. 6 is a process diagram for explaining steps of a method for manufacturing a flexible double tube according to a preferred embodiment of the present invention,
Figure 7 is an illustration of an enclosure according to another embodiment of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a flexible double tube according to a preferred embodiment of the present invention and a method of manufacturing the same will be described in detail with reference to the accompanying drawings.

In the case where a helical coil is applied to the outer tube of the flexible double tube, the present invention seals between the discontinuous section and the flange generated at both ends of the coil to prevent leakage.

For example, the exhaust gas temperature of a diesel vehicle can rise up to 550 ° C. Therefore, when the interlocking structure is not applied to the outer tube 20 and the inner tube 30, the surface temperature of the outer tube 20 and the inner tube 30 is increased, The silicone coating layer may be cured and may not be usable.

Therefore, in this embodiment, the structure of the flexible double tube 10 having the double interlocking structure to which the outer tube 20 and the inner tube 30 having the interlocking structure are applied so that the surface temperature of the double tube can be maintained at 250 ° C or less, Will be described in detail.

Of course, it should be noted that the present invention can be modified to apply a bellows type internal tube.

FIG. 3 is a perspective view of a flexible double tube according to a preferred embodiment of the present invention, and FIG. 4 is a partially enlarged sectional view of the flexible double tube shown in FIG.

Hereinafter, terms indicating directions such as 'left', 'right', 'forward', 'rearward', 'upward' and 'downward' are defined as indicating respective directions based on the states shown in the respective drawings do.

3 and 4, the flexible double tube 10 according to the preferred embodiment of the present invention includes an outer tube 20 to which a helical coil 23 is applied, A pair of flanges 40 and a pair of flanges 40 connected to both ends of the inner tube 30, the inner tube 30 and the outer tube 20 and the inner tube 30 and the outer tube 20 And a sealing device 50 installed between both ends and sealing to prevent leakage.

The outer tube 20 includes a first interlock part 21, a second interlock part 22, a first interlock part 22 and a second interlock part 22, which are alternately arranged by a predetermined length, And coils 23 arranged in a spiral shape along the overlapping portions of the first and second coils 21 and 22.

The first and second interlocking portions 21 and 22 may be manufactured in such a manner that the respective strip-shaped cover members are spirally rotated with respect to the axis and interconnected. In this manner, interconnecting the strip-shaped cover members is referred to as interlocking.

Here, the first interlocking portion 21 and the second interlocking portion 22 are formed by winding the belt-shaped cover members into a predetermined shape and then overlapping each other, and are arbitrarily divided according to their overlapping positions.

Each of the first and second interlocking portions 21 and 22 is made of a nonwoven fabric, a fabric, a synthetic resin, or a metal material, and the outer surfaces of the first and second interlocking portions 21 and 22 are coated with silicone A coating layer may be provided.

The first and second interlocking portions 21 and 22 are provided with coil arranging portions 24 and 25 and coil arranging portions 24 and 25 in which a substantially circular or Ω shaped space is formed, And a pair of connection portions 26, 27 connected to both ends of the connection portion 26.

The connecting portion 26 provided on one side, for example, the right side, of the pair of connecting portions 26 provided in the first interlock portion 21 may be formed to be shorter than the connecting portion 26 provided on the left side.

The connecting portion 27 provided on one side of the pair of connecting portions 27 provided on the second interlock portion 22 may be formed shorter than the connecting portion 27 provided on the right side.

Therefore, the coil 23 is disposed inside the space formed in the coil arranging portions 24 and 25 of the first and second interlocking portions 21 and 22, and is coupled to the outer surface of the coil arranging portions 26 and 27 And can be stably fixed by the fixed cap 28.

The inner tube 30 may be provided with an interlock hose which is inserted into and coupled to the pair of flanges 40 at both ends inside the outer tube 20. [

To this end, the inner tube 30 may include third and fourth interlocking portions 31, 32 that are folded and overlapped and connected in an interlocking manner.

The third interlock portion 31 has a first leg portion 33 and a first end portion 34 and the fourth interlock portion 32 has a second leg portion 35 and a second end portion 36 do.

The first leg portion 33 and the first end portion 34 are connected in a ⊃ shape and the second leg portion 35 and the second end portion 36 are connected in a ⊂ shape.

Here, the third interlocking unit 31 and the fourth interlocking unit 42 are shown for the sake of convenience, and the present invention is not limited thereto, and may be configured in the reverse order.

The first end portion 34 is inserted into the fourth interlock portion 32 and the second end portion 36 is inserted into the third interlock portion 31. The first end portion 34 and the second end portion 36 And may be configured to be in surface contact or line contact with each other.

Thus, the inner tube having the interlocking structure prevents leakage of the exhaust gas due to contact of the third and fourth interlock portions or contact with each other in one line regardless of the movement of the inner tube in the interlocking structure. Even if tensile force or vertical drag acts, This does not work.

In the meantime, although the inner pipe is configured as an interlocking structure in the present embodiment, the present invention is not necessarily limited to this, and the inner pipe may be modified to apply a corrugated corrugated pipe having an acid and a bone.

Each of the pair of flanges 40 is formed into a substantially cylindrical shape and an inner surface of each flange 40 is provided with a coupling portion 41 to which the inner tube 30 and the outer tube 20 are coupled.

Each of the engaging portions 41 may be bent toward the central portion of the double tube 10 to have a substantially '┏' or '┓' shape in cross section.

The engaging portion 41 may be formed with an engaging space 42 to be coupled with the one end of the sealing device 50 and the outer tube 20 and an engaging groove 43 to which the inner tube 30 is coupled.

A plurality of support members 44 may be installed at each of the engaging portions 41 so as to be spaced apart from each other by a predetermined angle so as to fix both ends of the outer tube 20. [

The support member 44 may be bent toward the outer side of the double tube 10 to have a substantially '┓' or '┏' shape in cross section.

For example, three support members 44 may be provided at each of the engaging portions 41 at intervals of 120 degrees.

Of course, the number of the support members 44 may be changed so that two or four or more thereof are installed.

Meanwhile, since the coil 23 applied to the outer tube 20 is formed in a spiral shape, a discontinuous section is formed at both ends of the outer tube 20.

Therefore, when the support member 44 is provided in a state where a plurality of coils 23 are overlapped with each other and both ends of the outer tube 20 are coupled to the coupling portion 41, A fine space may be formed between the first and second portions 41 and 42. [

Thus, the sealing device 50 is disposed at both ends of the outer tube 20 to seal the spaces between the opposite ends of the outer tube 20 and the engaging portions 41, thereby hermetically sealing them, thereby preventing leakage.

The configuration of the sealing device will be described in detail with reference to Figs. 4 and 5. Fig.

5 is a partial exploded view of the double tube shown in Fig.

The sealing device 50 may be provided with a substantially ring-shaped gasket member, as shown in Figs.

Specifically, the sealing device 50 includes first and second ring members 51 and 52 which are formed in a substantially ring shape and overlap each other, and the inner side of the first and second ring members 51 and 52 And the outer edge can be joined to each other in a welding manner.

The first and second ring members 51 and 52 can be formed into a ring shape using a metal material or a synthetic resin material.

A preset amount of oil is introduced between the first ring member 51 and the second ring member 52 and the first ring member 51 and the second ring member 51 are heated in the heating process of both ends of the assembled double pipe 10, The pressure space S in which a certain pressure acts is generated by generating pressure while the oil injected between the ring members 52 is vaporized and expanded.

That is, as the oil charged between the first ring member 51 and the second ring member 52 expands to a volume of about 800 times or more while being vaporized when heated to a temperature of the boiling point or higher, for example, about 200 ° C or higher, The gap between the central portion of the first ring member 51 and the central portion of the second ring member 52 is expanded and a pressure space S is formed.

In the pressure space S thus formed, a constant pressure is applied by the oil that has changed to the gaseous state.

The intermediate space between the first ring member 51 and the second ring member 52 is separated from each other by the pressure space S formed in this manner and the pressure space S can be maintained even when the temperature is lowered after the end of the heating process, The first and second ring members 51 and 52 are maintained in the same expanded shape.

Accordingly, the sealing device 50 hermetically closes the space between both ends of the outer tube 20 and the engaging portion 41 of the flange 40, so that the present invention can be applied to the outer tube 20 and the flange 40, It is possible to prevent leakage through the space.

On the other hand, the amount of oil injected between the first ring member 51 and the second ring member 52 is set so that the volume of the pressure space to be formed between the first ring member 51 and the second ring member 52 The area of the first ring member 51 and the area of the second ring member 52, and the like.

Next, a method of manufacturing a flexible double tube according to a preferred embodiment of the present invention will be described in detail with reference to FIG.

FIG. 6 is a process diagram for explaining steps of a method for manufacturing a flexible double tube and a sealing device according to a preferred embodiment of the present invention.

In step S10 of Fig. 6, the operator manufactures the sealing device 50. Fig.

In other words, the sealing device 50 can be manufactured by joining the inner and outer edges of the first and second ring members 51 and 52 in a welded manner.

At this time, a predetermined amount of oil is injected between the first and second ring members 51, 52 so as to expand and vaporize by heating to form a pressure space S.

In step S12, the operator assembles the outer tube 20 and the inner tube, respectively.

That is, a spiral coil 23 is disposed on the overlapped portion in a state in which a part of the first and second interlocking portions 21, 22, which are formed in a band shape and have a predetermined length, are arranged so as to overlap with each other, And the outer tube 20 is manufactured by winding in a spiral shape with the center.

At this time, the fixed cap 28 is coupled to the outer surface of each coil arrangement part 24 of the outer tube 20.

The inner tube 30 is assembled by combining the third and fourth interlock portions 31 and 32 with each other in the interlocking structure at Step S14.

The outer tube 20 is disposed on the outer side of the inner tube 30 in step S16 and the two tubes 20 and 20 are coupled to each other with the sealing device 50 and the flange 40 disposed on both ends of the outer tube 20, ).

Both ends of the assembled double tube 10 are heated in step S18.

At this time, both ends of the double pipe 10 are connected to the first and the second ring members 51 and 52 of the sealing device 50 at predetermined preset temperatures by the induction heating method in the heating chamber (not shown) It may be heated to a temperature higher than the boiling point for a predetermined set time.

Here, the set temperature may be set to about 200 DEG C, and the set time may be set to about 30 minutes.

Then, as the heated oil expands and vaporizes, a pressure space S is formed between the first and second ring members 51, 52 of the sealing device 50, and the sealing device 50 is expanded The space between the opposite ends of the outer tube 20 and the engaging portions 41 of the flanges 40 is sealed (S20).

The pressure space S formed in the sealing device 10 maintains the deformed shape even if the atmospheric temperature is lower than the boiling point of the oil so as to prevent leakage between the outer tube 20 and the flange 40 .

Particularly, when the double pipe 10 is mounted on the exhaust pipe of the vehicle or the like, the sealing device 50 is operated to return the exhaust gas to the outside The space between the pipe 20 and the flange 50 is completely sealed and airtight so that leakage can be blocked.

Through the above-described process, the sealing device is applied between the outer tube and the flange to completely seal the space between the opposite ends of the outer tube and the flange, thereby airtightly preventing leakage.

Accordingly, the present invention is capable of preventing the leakage due to the discontinuous section by sealing the space between the member having the discontinuous section such as the helical coil and the other member completely.

Meanwhile, in the above-described embodiment, the ring-shaped first and second ring members are arranged side by side in the lateral direction and are overlapped with each other, and then the inner and outer edges are joined to manufacture the sealing device. However, The present invention is not limited thereto.

For example, Figure 7 is an illustration of an enclosure in accordance with another embodiment of the present invention.

As shown in FIG. 7, the sealing device 50 using the gasket according to another embodiment of the present invention is configured such that the first and second strip members 53 and 54 are arranged side by side along the vertical direction And then joining both side edges thereof, molding them into a ring shape, and joining both ends by welding.

Therefore, as the oil injected between the first and second belt members 53, 54 is expanded and vaporized by the heating process, the central portions of the first and second belt members 53, 54 are convex upward and downward, respectively The pressure space S is formed between the first and second belt members 53,

As described above, according to the present invention, a pressure space is formed inside a pair of belt members so that the members vertically connected can be hermetically sealed.

Although the invention made by the present inventors has been described concretely with reference to the above embodiments, the present invention is not limited to the above embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

That is, in the above-described embodiments, the structure of the flexible double tube having the double interlocking structure in which the inner tube and the outer tube having the interlocking structure are respectively applied is explained. However, according to the present invention, the bellows type inner tube .

In addition, the present invention can be applied not only to a double tube, but also to a single tube having a single structure or multiple tubes having a triple or more structure.

In addition, the present invention may be modified so as to be applicable not only to the tube but also to a connecting device of various members in which a space is generated due to a discontinuous section between a pair of members to be coupled with each other.

The present invention relates to a flexible double tube which completely seals the space between the opposite ends of the outer tube and the flange by sealing the space between both ends of the outer tube to which the helical coil is applied and the flange, Methodology.

10: Double tube
20: outer tube 21, 22: first and second interlock parts
23: coils 24, 25:
26, 27: connecting portion 28: fixed cap
30: inner pipe 31, 32: third and fourth interlock parts
33, 35: first and second leg portions 34, 36: first and second ends
40: flange 41:
42: engaging space 43: engaging groove
44: support member 50: sealing device
51, 52: first and second ring members 53, 54: first and second belt members
S: Pressure space

Claims (8)

An outer tube to which a helical coil is applied,
An inner tube disposed inside the outer tube,
A pair of flanges connected to both ends of the inner tube and the outer tube,
And a sealing device installed between the pair of flanges and both ends of the inner tube and the outer tube and sealing to prevent leakage through a space between the outer tube and the flange,
The sealing device includes first and second ring members each formed in a ring shape and overlapping each other,
Wherein the oil inflated between the first and second ring members expands to form a pressure space therein while expanding and vaporizing by heating to seal the space between both ends of the outer tube and the flange to thereby airtight. Double pipe. delete The method according to claim 1,
Wherein the first and second ring members have their inner and outer edges joined together,
The pressure space maintains the same shape even if the atmospheric temperature is lower than the boiling point of the oil,
Wherein when the temperature rises in the use environment, the inside pressure is increased, and both ends of the outer tube and the flange are sealed. The method according to claim 1,
The outer tube includes a first interlock part and a second interlock part which are alternately arranged by a preset length and are partially overlapped with each other and connected in an interlocking manner,
And a coil provided in a spiral shape along the overlapping portions of the first and second interlock portions,
The first and second interlock portions are each provided with a coil arrangement portion in which the coils are arranged,
And a fixed cap for fixing the coil is coupled to the coil arrangement portion of the first and second interlock portions. 5. The method of claim 4,
Wherein the inner tube is provided with an interlock hose in which both side ends of the inner tube are inserted and coupled to the pair of flanges. 5. The method of claim 4,
Wherein the inner tube is provided with a corrugated corrugated tube having an acid and a valley. (a) manufacturing a sealing device by overlapping a pair of ring members,
(b) fabricating an outer tube by arranging a coil in a spiral shape along the overlapping portion of the first interlocking portion and the second interlocking portion, which are alternately arranged by a predetermined length and are overlapped with each other and interlocked with each other,
(c) disposing an inner tube on the inner side of the outer tube and a pair of flanges on both ends of the inner tube and the outer tube to manufacture a double tube; and
(d) sealing both ends of the double tube by heating to prevent leakage through a space between the pair of flanges and both ends of the inner tube and the outer tube, and through the space between the outer tube and the flange,
Wherein the oil is inflated between the pair of ring members to expand and vaporize by heating to form a pressure space so that a space between both ends of the outer tube and the flange is sealed and airtight. 8. The method of claim 7,
In the step (a), the inner and outer edges of the pair of ring members are bonded to each other,
The pressure space maintains the same shape even if the atmospheric temperature is lower than the boiling point of the oil,
Wherein when the temperature rises in the use environment, the inner pressure increases while sealing between the both ends of the outer tube and the flange.

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