JP2006308028A - Double pipe and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double pipe whose chattering sounds are prevented due to the intermittent contact of an outer pipe with an inner pipe during vibration. <P>SOLUTION: The double pipe 1 comprises the outer pipe 11, the inner pipe 12 passing through the outer pipe 11 through both ends 11b, 11c of the outer pipe 11, and branch pipes 16 inserted into both ends 11b, 11c of the outer pipe 11, respectively. Both ends 11b, 11c of the outer pipe 11 are provided with an approximately cylindrical inner pipe supporting portion 13 for closing and supporting the inner pipe 12 and an approximately cylindrical branch pipe supporting portion 15 for closing and supporting the branch pipe 16. The inner pipe supporting portion 13 is located approximately parallel to the extending direction of a general part 11a of the outer pipe 11, inside the general part 11a of the outer pipe 11 in a projection view along the extending direction of the general part 11a of the outer pipe 11. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a double pipe and a method for producing the same.

A conventional double tube is disclosed in Patent Document 1. In the double tube of Patent Document 1, after processing the end of the outer tube into a shape having two cylindrical portions, the inner tube is inserted into one cylindrical portion (inner tube support portion) and the other tube It is the structure brazed in the state which inserted the branch pipe in the shape part (branch pipe support part).
JP 58-121394 A

  In the conventional structure, the inner tube is in contact with the inner peripheral surface of the general portion of the outer tube, and when placed on a vibrating body such as a vehicle, the inner tube and the outer tube are intermittently contacted by vibration. May cause chatter noise.

  In the conventional structure, there is a possibility that the gap between the processed open end of the outer tube and the inner tube and the branch tube inserted into the open end cannot be completely sealed by brazing.

  An object of the present invention is to prevent the chatter noise from being generated due to intermittent contact between the outer tube and the inner tube due to vibration.

  The invention according to claim 1 is a double pipe, which is an outer pipe, an inner pipe that penetrates the outer pipe through both ends of the outer pipe, and a branch that is inserted into each of both ends of the outer pipe. And both ends of the outer tube have a substantially cylindrical inner tube support portion that hermetically supports the inner tube, and a substantially cylindrical branch tube support portion that hermetically supports the branch tube. The inner tube support portion is substantially parallel to the extending direction of the general portion of the outer tube and is located inside the general portion of the outer tube.

  A second aspect of the present invention is the double pipe according to the first aspect, wherein the inner pipe support part and the branch pipe support part are independent via a joint part.

  A third aspect of the present invention is the double pipe according to the second aspect, wherein the branch pipe support part is inclined with respect to the inner pipe support part.

  Invention of Claim 4 is the double pipe of any one of Claims 1-3, Comprising: The said branch pipe support part is larger diameter than the said inner pipe support part, It is characterized by the above-mentioned. To do.

  Invention of Claim 5 is a manufacturing method of a double pipe, Comprising: The process of decentering the edge part of the said outer pipe to one direction, The cylindrical inner pipe support part for the eccentric edge part of the said outer pipe And a step of pressing into a shape having a cylindrical branch pipe support, a step of passing the inner pipe through the outer pipe through the inner pipe support at both ends of the outer pipe, and a branch pipe at both ends of the outer pipe A step of inserting a branch pipe into each of the support parts; and a step of brazing a joint portion of the outer pipe, the inner pipe and the branch pipe.

  Invention of Claim 6 is a manufacturing method of the double pipe of Claim 5, Comprising: In the said press process, the said inner pipe support part and the said branch pipe support part become independent via a junction part. It is characterized by pressing.

  The invention according to claim 7 is the method for manufacturing the double pipe according to claim 6, wherein in the pressing step, the branch pipe support part is inclined so as to be inclined with respect to the inner pipe support part. It is characterized by doing.

  Invention of Claim 8 is a manufacturing method of the double pipe of Claim 6 or 7, Comprising: It press-processes so that the said branch pipe support part may be larger diameter than the said inner pipe support part. It is characterized by.

  The invention according to claim 9 is the method of manufacturing a double pipe according to any one of claims 5 to 8, wherein in the brazing step, one of the inner pipe and the branch pipe is directed upward. In a state where the other is disposed below, the joint portion of the outer tube, the inner tube, and the branch tube is brazed while supplying the brazing material upward.

  Invention of Claim 10 is a manufacturing method of the double pipe of any one of Claims 5-8, Comprising: In the said brazing process, it is a large diameter among the said inner pipe and the said branch pipe. The joint portion of the outer tube, the inner tube, and the branch tube is brazed while supplying the brazing material to the upper tube in a state where the small-diameter tube is disposed below the tube. .

  According to the first aspect of the invention, the outer peripheral surface of the inner tube is reliably separated from the inner peripheral surface of the general portion of the outer tube, and the inner tube and the outer tube are intermittently contacted even when the double tube vibrates. As a result, the possibility of chatter noise is extremely reduced.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1, the inner pipe support part and the branch pipe support part are provided independently, so that the inner pipe and the branch pipe are supported by the independent support parts. And excellent support stability.

  According to the invention of claim 3, in addition to the effect of the invention of claim 2, the branch pipe support part is inclined with respect to the inner pipe support part, and therefore, between the inner pipe support part and the branch pipe support part. The joint part (joining allowance) formed in this becomes long, thereby improving the sealing property at the branch part of the double pipe and increasing the reliability against leakage.

  According to the invention of claim 4, in addition to the effect of the invention of claim 2 or 3, when the end portion of the outer tube is processed, the joined portion is hardly thinned, and the end portion of the outer tube is easily processed.

  According to the invention of claim 5, in the manufactured double pipe, the inner pipe support part at the end of the outer pipe is positioned on the inner diameter side from the inner peripheral surface of the general part of the outer pipe. Therefore, the inner tube supported by the inner tube support portion of the outer tube is surely separated from the outer peripheral surface of the outer tube, and even if the double tube vibrates, the inner tube and the outer tube are intermittently contacted to generate chatter noise. Is very unlikely to occur.

  According to the invention of claim 6, in addition to the effect of the invention of claim 5, since the inner tube support part and the branch pipe support part are provided independently, the inner pipe and the branch pipe are supported by the independent support parts, respectively. And excellent support stability.

  According to the seventh aspect of the invention, in addition to the effect of the sixth aspect of the invention, the branch pipe support portion is inclined with respect to the inner pipe support portion, and therefore, between the inner pipe support portion and the branch pipe support portion. The joining allowance of the two-ply joint formed is increased, thereby improving the sealing performance at the branch portion of the double pipe and increasing the reliability with respect to leakage.

  According to the invention of claim 8, in addition to the effect of the invention of claim 6 or 7, when the end portion of the outer tube is processed, the joining portion is hardly thinned, and the end portion of the outer tube is easily processed.

  According to the invention of claim 9, in addition to the effect of the invention of any one of claims 5 to 8, the inner pipe and the branch pipe can be brazed to the outer pipe at a time in the brazing step. In addition, a small amount of brazing material can be used.

  According to the invention of claim 10, the same effect as that of the invention of claim 9 can be obtained. In addition, the amount of brazing material supplied to the inner tube support portion and the branch tube support portion tends to be uniform, and the sealing performance at the end of the outer tube is high even if the amount of brazing material used is small.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 11 show an embodiment of the present invention.

"Overall structure of double pipe"
FIG. 1 is a perspective view showing a double tube of this embodiment. As shown in FIG. 1, the double tube 1 includes an independent outer tube 11 and an inner tube 12. The inner tube 12 flows the first fluid L1 (indicated by an arrow in FIG. 1), and is between the outer tube 11 and the inner tube 12 (between the inner peripheral surface of the outer tube 11 and the outer peripheral surface of the inner tube 12). A second fluid L2 (indicated by an arrow in FIG. 1) can flow through the passage. The flow directions of the first fluid L1 and the second fluid L2 in FIG. 1 are an example.

"Branch structure"
At both ends of the double tube 1, there are branch portions 1b and 1c. Hereinafter, the branch portions 1b and 1c of the double pipe 1 will be described in more detail.

  In the branch parts 1b and 1c of the double pipe 1, the end parts 11b and 11c of the outer pipe 11 are independent cylindrical inner pipe support parts 13 (not necessarily cylindrical in the present invention) and cylindrical branches. It has a tube support 15 (not necessarily cylindrical in the present invention). The inner tube 12 penetrates the outer tube 11 through the inner tube support portions 13 at both ends of the outer tube 11, and is hermetically brazed in a state where the inner tube 12 is supported by both the inner tube support portions 13. Further, the branch pipe support portions 15 at both ends of the outer pipe 11 are hermetically brazed with the branch pipe 16 inserted and supported.

  The inner tube support portion 13 and the branch tube support portion 15 are formed in a closed cross-sectional structure that is independent from each other with a two-layer joint portion 17 interposed therebetween. That is, the end portions 1b and 1c of the beam outer tube 11 have a cross-sectional shape formed of glasses.

  The inner tube support portion 13 is formed to have a smaller diameter than the linear general portion 11 a of the outer tube 11. Further, the inner tube support portion 13 is smoothly continuous with the general portion 11a of the outer tube 11 via the inclined portion 18, and from the inner peripheral surface of the general portion 11a in the projection view along the extending direction of the general portion 11a. Located on the inner diameter side. In this example, the inner tube 12 is positioned at the axial center position of the general portion 11 a of the outer tube 11. That is, the axis of the inner tube 12 coincides with the axis of the general portion 11a of the outer tube 11. In other words, the axis of the inner tube support portions 13 and 14 and the axis of the general portion 11a of the outer tube 11 are aligned. And are consistent.

  The branch pipe support 15 is formed to have a smaller diameter than the general part 11 a of the outer pipe 11 and a larger diameter than the inner pipe support 13. Further, the branch tube support portion 15 has an axis that is offset from the axis of the general portion 11 a of the outer tube 11 and is inclined with respect to the general portion 11 a and the inner tube support portion 13 of the outer tube 11.

"Production method of double pipe"
Next, a method for manufacturing a double pipe will be described with reference to FIGS.

  The manufacturing method of the double pipe includes a step of eccentrically ending the end portions 11b and 11c of the outer tube 11, and a cylindrical inner tube support portion 13 and a cylindrical branch tube support for the eccentric end portions 11b and 11c of the outer tube 11. A step of pressing into a shape having a portion 15, a step of passing the inner tube 12 through the outer tube 11 through the inner tube support portions 13 of both ends 11 b and 11 c of the outer tube 11, and a branching of both ends 11 b and 11 c of the outer tube 11. A step of inserting the branch pipe 16 into the pipe support portion 15, and a step of brazing the joint portion of the outer pipe 11, the inner pipe 12 and the branch pipe 16.

Eccentric Step First, as shown in FIGS. 3 to 4, the end portion 11 b of the outer tube 11 is press-fitted into the end portion 11 b of the linear outer tube 11 before processing, so that the general portion 11 a of the outer tube 11 is inserted. Is decentered while being curved (FIG. 4). A part X of the deformed end portion 11b of the outer tube 11 is formed in parallel with the general portion 11a of the outer tube 11 and projected along the extending direction of the general portion 11a of the outer tube 11 as shown in FIG. When viewed from the surface, the outer tube 11 is eccentric to the inner diameter side of the general portion 11a. Further, a part Y of the deformed end portion 11 b of the outer tube 11 is inclined so as to expand outward with respect to the general portion 11 a of the outer tube 11.

  Here, the punch 22 is substantially rod-shaped as a whole, and has a structure having an inclined surface 22b at the tip when viewed in a longitudinal section along the axial direction as shown in FIG. 4a and in the radial direction as shown in FIG. 4b. When viewed along the transverse cross section, one is a deformed ellipse in which one is a large-diameter semicircle and the other is a small-diameter semicircle. In addition, the punch 22 is positioned before the punching shown in FIG. 3, as shown in FIG. 3 a, and is positioned on the outer side in the axial direction of the outer tube 11 and along the axial direction of the outer tube 11. Is partially wrapped around the periphery of the outer tube 11. Reference numeral 21 in the figure denotes a die, and the die 21 includes a holding hole 21 a for holding the outer tube 11. The die 21 includes an inclined surface 21b corresponding to the inclined surface 22b at the tip of the punch 22 on the opening end side of the holding hole 21a. The inclined surface 21 b of the die 21 supports the end portion processing of the outer tube 11 by the punch 22.

Next, as shown in FIGS. 5 to 6, the outer tube end portion 11b is pressed from the radial direction with the two core bars 24 and 25 being inserted into the end portion 11b of the eccentric outer tube 11. The mold surface 26b of the mold 26 is crushed into a cross-section glasses. At this time, the cored bar 24 matches the diameter of the inner tube 12 and the cored bar 25 matches the diameter of the branch pipe 16. The cored bar 24 corresponding to the inner tube 12 is arranged corresponding to the portion X eccentrically inward with respect to the general portion 11a of the outer tube 11 as shown in FIG. Similarly, as shown in FIG. 5, 25 is arranged corresponding to a portion Y that is curved so as to expand outward with respect to the general portion 11a of the outer tube.

  As shown in FIG. 6, one cylindrical portion of the end portion 11 b deformed into a cross-section glass shape becomes the inner tube support portion 13, and the other cylindrical portion becomes the branch tube support portion 15. Among these, the inner tube support portion 13 is located more inside than the inner peripheral surface of the general portion 11 a of the outer tube 11 in the projection view along the extending direction of the general portion 11 a of the outer tube 11.

  The shape shown in FIG. 7 is obtained through the eccentric process and the press process described above. And the same process is given to the other end part 11c of the outer tube | pipe 11, and the shape shown in FIG. 8 is obtained. At this time, the inner tube support portions 13 at both ends 1b and 1c are provided substantially parallel to the general portion 11a of the outer tube 11. Moreover, the inner pipe support part 13 at one end and the inner pipe support part 13 at the other end are provided on a straight line. As shown in FIG. 7 a, the inner tube support portions 13 at both ends are located on the inner diameter side of the inner peripheral surface of the general portion 11 a of the outer tube 11.

Insertion Step The inner tube 12 and the two branch tubes 16 are inserted into the outer tube 11 obtained as described above as shown in FIG. 9 to form a temporary assembly. It is supported by the tool 103. At this time, one of the inner tube support portion 13 and the branch tube support portion 15 (in this example, the branch tube support portion 15) is disposed above the other (in this example, the inner tube support portion 13). In other words, one of the inner pipe 12 and the branch pipe 16 (the branch pipe 16 in this example) is disposed above the other (the inner pipe 12 in this example).

"Brazing process"
Then, as shown in FIG. 10, the brazing material 111 is melted while the burner 113 is moved up and down (arrow Z in FIG. 10 b) while supplying the brazing material 111 to the opening end of the upper support portion 15 by the feeder 110. The brazing material 111 is inserted into the contact surface between the outer tube 11 and the branch tube 16 and the contact surface between the outer tube 11 and the inner tube 12, and the gap is sealed with the brazing material 111.

Cooling process Finally, as shown in FIG. 11, the double pipe 1 shown in FIG. 1 and FIG. 2 is obtained by removing the flux while cooling both ends 11b and 11c of the outer pipe 11 by the shower machine 120.

"effect"
Next, the effect of this embodiment will be described.

  First, according to the double tube 1 of the present embodiment, the inner tube support portion 13 is located on the inner diameter side of the inner peripheral surface of the general portion 11a of the outer tube 11, so that the inner tube support of the outer tube 11 is supported. The inner tube 12 supported by the portion 13 is reliably separated from the inner peripheral surface of the outer tube 11. Therefore, even if the double pipe 1 vibrates, the inner pipe 12 and the outer pipe 11 can intermittently come into contact with each other and chatter noise can be prevented from being generated.

  Secondly, the adjacent inner pipe support part 13 and the branch pipe support part 15 are provided independently. Therefore, since the inner pipe 12 and the branch pipe 16 are supported by the independent cylindrical support portions 13 and 15, respectively, the cylindrical support portions 13 and 15 communicate with each other without being independent (for example, Patent Document 1). Excellent support stability.

  Further, in the double pipe 1 of the present embodiment, the branch pipe support part 15 is inclined with respect to the inner pipe support part 13. For this reason, the two-layered joining portion 17 (joining allowances d1 and d2) formed between the inner tube support portion 13 and the branch tube support portion 15 is lengthened, whereby the branch portions 1b at both ends of the double tube 1 are lengthened. The sealing property in 1c is improved.

  Further, since the branch pipe support portion 15 is inclined with respect to the inner pipe support portion 13, a structure in which the inner pipe support portion and the branch pipe support portion are adjacently arranged in parallel as in the prior art (for example, Patent Documents). Compared to 1), it is easy to cope with various piping layouts by freely changing the inclination angle of the branch pipe 16.

  Moreover, according to the manufacturing method of the double pipe 1 of the present embodiment, the eccentric step of decentering the end portions 11b, 11c of the outer tube 11 with respect to the general portion 11a, and the end portion 11b of the eccentric outer tube 11, The inner tube 12 is connected to the outer tube 11 through a pressing process in a shape having two cylindrical portions 13 and 15 by sandwiching 11c from the radial direction by a press die 26, and inner tube support portions 13 at both ends 11b and 11c of the outer tube 11. A step of inserting the branch pipe 16 into each of the branch pipe support portions 15 at both ends of the outer pipe 11, and brazing the joint portion of the outer pipe 11, the inner pipe 12 and the branch pipe 16. And a step of performing. Therefore, in the obtained double pipe 1, the inner pipe support part 13 is located on the inner diameter side of the inner peripheral surface of the general part 11 a of the outer pipe 11. Therefore, even if the double pipe 1 vibrates, the inner pipe 12 and the outer pipe 11 are unlikely to contact intermittently and chatter noise is unlikely to occur.

  Moreover, according to the manufacturing method of the double pipe 1 of this embodiment, since it is the method of curving the edge parts 11b and 11c of the outer tube | pipe 11 with the punch 22 from an axial direction in an eccentric process, The portion 11b can be expanded. Therefore, the diameter size of the inner tube 12 and the branch tube 16 supported by the end portions 11b and 11c of the outer tube 11 can be set large. In the present invention, the end portions 11b and 11c of the outer tube 11 may be curved by other methods.

  In addition, according to the method for manufacturing the double pipe 1 of the present embodiment, the inner pipe support portion 13 and the branch pipe support portion 15 are pressed by the press die so as to be independent via the joint portion 17. At the end portions 1b and 1c of the obtained double tube 1, the cylindrical support portions 13 and 15 have an independent structure. Therefore, compared with the structure (for example, patent document 1) in which the cylindrical support parts 13 and 15 are connected independently, it is excellent in support stability.

  Moreover, according to the manufacturing method of the double tube 1 of the present embodiment, a small gap d5 (in this example, 0.05 mm to 5 mm) is formed in the two-layered joint portion 17 obtained by pressing as shown in FIGS. 1 mm). Therefore, the brazing property of the joint portion 17 is improved.

  Further, according to the method for manufacturing the double pipe 1 of the present embodiment, the press working is performed so that the branch pipe support 15 is inclined (θ1, θ2) with respect to the inner pipe support 13 by a press die. Therefore, the obtained double pipe 1 has a large joint 17 (joining allowances d1, d2) between the inner pipe support part 13 and the branch pipe support part 15, and both ends 1b, 1c of the double pipe 1 are increased. The sealing performance of the is improved.

  Moreover, according to the manufacturing method of the double pipe 1 of this embodiment, it press-processes so that the branch pipe support part 15 may be larger diameter than the inner pipe support part 13 with a press die. Therefore, in the press process, the joint portion 17 is not easily thinned, and the end portion processing of the outer tube 11 is facilitated.

  Further, according to the method for manufacturing a double pipe of the present embodiment, in the brazing step, one of the inner pipe 12 and the branch pipe 16 (in this example, the branch pipe 16) is directed upward while the other (in this example, the inner pipe 12). The brazing material 111 is supplied to the upper side (in this example, the branch pipe 16), and the joint portion of the outer pipe 11, the inner pipe 12 and the branch pipe 16 is brazed. Therefore, the excess of the brazing material 111 supplied to the upper pipe (in this case, the branch pipe 16) is supplied to the lower pipe (in this example, the inner pipe 12). As a result, the inner pipe 12 and the branch pipe 16 can be brazed at once without the need for the brazing material 111 separately. Moreover, a small amount of brazing material 111 is used.

  Also, at this time, as shown in FIG. 10, the minute gap d5 of the two-layer joint portion 17 becomes the upper and lower brazing material supply passages, and the brazing material is quickly supplied to the lower pipe (in this example, the inner pipe 12). , Brazing is improved.

  Further, according to the method of manufacturing a double pipe of the present embodiment, in the brazing process, the large diameter pipe (in this example, the branch pipe 16) of the inner pipe 12 and the branch pipe 16 is moved upward with a small diameter pipe (this In the example, the joint portion of the outer tube 11, the inner tube 12 and the branch tube 16 is supplied while supplying the brazing material 111 to the upper tube (in this example, the branch tube 16) with the inner tube 12) disposed below. Brazing. In other words, the upper pipe (branch pipe 16 in this example) and the brazing material 111 supplied to the lower pipe (in this example, the inner pipe 12) to which the brazing material 111 is indirectly supplied are not insufficient. The brazing material 111 is easily supplied uniformly to the lower pipe (in this example, the inner pipe 12), and the sealing performance of the ends 1b and 1c of the double pipe 1 is enhanced even if a small amount of brazing material 111 is used.

  In addition, this invention is not limitedly interpreted by the above-mentioned embodiment.

  For example, in the above-described embodiment, as shown in FIGS. 3 to 4, the end portion 11 b of the outer tube 11 is decentered by the punch 22 from the axial direction of the outer tube 11 before processing. The end portion 11b of the outer tube 11 may be bent by a predetermined angle θ with respect to the general portion 11a of the outer tube 11 by a press or bender from the direction.

  In the above embodiment, the end portions 11b and 11c of the outer tube 11 are separately pressed. However, in the present invention, as shown in FIGS. 12 to 14, both end portions 11b of the outer tube. 11c may be pressed at the same time. FIG. 12 is a view showing a press die 26B used for press working. FIG. 13 shows a state before pressing by the press die 26. The outer tube 11 in which both end portions 11b and 11c are eccentric with respect to the general portion 11a is arranged on the press die 26, and the outer tube 11 The figure which shows the state which inserted the metal core 24 and the metal core 25 into the edge parts 11b and 11c. FIG. 14 is a diagram showing a state after pressing.

  In the above embodiment, the brazing filler metal 111 is supplied by the feeder 110 as shown in FIG. 10, but in the present invention, for example, as shown in FIG. The brazing materials 111A and 111B may be applied to the end portions 11b and 11c of the outer tube 11 and heated with a burner.

  Further, in the above-described embodiment, the branch pipe support 15 is inclined with respect to the inner pipe support 13, but in the present invention, for example, as shown in FIG. 16, the inner pipe support 13 and the branch pipe support are provided. The part 15D may be set in parallel. Various other changes may be made without departing from the technical idea of the present invention.

The perspective view of the double tube of one embodiment of the present invention. Sectional drawing of the double pipe of FIG. Among explanatory drawings explaining the manufacturing method of a double tube, it is a figure which shows the state before the punch process which decenters the edge part of an outer tube, Comprising: (a) is a side view, (b) is a top view. Among explanatory drawings explaining the manufacturing method of a double tube, it is a figure which shows the punch process which decenters the edge part of an outer tube, Comprising: (a) is a side view, (b) is a top view. Among explanatory drawings explaining the manufacturing method of a double pipe, it is a figure which shows the state before the press process which presses the edge part of the eccentric outer pipe, (a) is a side view, (b) is a top view . It is a figure which shows the press process which presses the edge part of the eccentric outer pipe | tube among explanatory drawings explaining the manufacturing method of a double pipe, (a) is a side view, (b) is a top view. Among explanatory drawings explaining the manufacturing method of a double tube, it is a figure which shows the shape of the one end part of the outer tube which finished the edge part process, (a) is a top view, (b) is a longitudinal direction of an outer tube FIG. The figure which shows the shape of the outer pipe | tube which complete | finished the edge part process of both ends among explanatory drawings explaining the manufacturing method of a double pipe. The figure which shows the state after insertion of an inner pipe and a branch pipe among explanatory drawings explaining the manufacturing method of a double pipe. The figure which shows during brazing among explanatory drawings explaining the manufacturing method of a double pipe. The figure which shows the cooling process after brazing among explanatory drawings explaining the manufacturing method of a double pipe. It is a figure explaining the modification of a press process, Comprising: The top view which shows the press metal mold | die used for a press process. It is a figure explaining the modification, Comprising: The top view which shows the state which has arrange | positioned the outer tube | pipe whose end part was eccentric to the press die. It is a figure explaining the modification, Comprising: The top view which shows the state after a press. The figure which shows the modification of a brazing process. The figure which shows the modification of the double tube | pipe concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Double pipe 1b, 1c ... Branch part (end part)
DESCRIPTION OF SYMBOLS 11 ... Outer pipe 11a ... General part 11b, 11c ... End part 12 ... Inner pipe 13 ... Inner pipe support part 15 ... Branch pipe support part 15D ... Branch pipe support part 16 ... Branch pipe 17 ... Joint part 111 ... Brazing material 111A, 111B ... brazing material

Claims (10)

An outer tube (11), an inner tube (12) penetrating the outer tube (11) through both ends (11b, 11c) of the outer tube (11), and both ends (11b, A branch pipe (16) inserted into each of 11c),
Both end portions (11b, 11c) of the outer tube (11) are substantially cylindrical inner tube support portions (13) for hermetically supporting the inner tube (12), and substantially for hermetically supporting the branch tube (16). A cylindrical branch pipe support (15),
The inner tube support portion (13) is substantially parallel to the extending direction of the general portion (11a) of the outer tube (11) and is located inside the general portion (11a) of the outer tube (11). A double tube (1) characterized in that A double pipe (1) according to claim 1,
The double pipe (1), wherein the inner pipe support (13) and the branch pipe support (15) are independent via a joint (17). A double pipe (1) according to claim 2,
The double pipe (1), wherein the branch pipe support (15) is inclined with respect to the inner pipe support (13). The double pipe (1) according to any one of claims 1 to 3,
The double pipe (1), wherein the branch pipe support (15) has a larger diameter than the inner pipe support (13). Decentering the end (11b) of the outer tube (11) in one direction;
Pressing the eccentric end (11b) of the outer pipe (11) into a shape having a cylindrical inner pipe support (13) and a cylindrical branch pipe support (15);
Passing the inner pipe (12) through the outer pipe (11) through the inner pipe support (13) at both ends (11b, 11c) of the outer pipe (11);
Inserting the branch pipe (16) into each of the branch pipe support portions (15) at both ends (11b, 11c) of the outer pipe (11);
Brazing the joint of the outer pipe (11), the inner pipe (12) and the branch pipe (16);
A method of manufacturing a double pipe, comprising: It is a manufacturing method of the double pipe according to claim 5,
In the pressing step, the inner pipe support portion (13) and the branch pipe support portion (15) are pressed so as to be independent via a joint portion (17). It is a manufacturing method of the double pipe according to claim 6,
In the pressing step, the double pipe manufacturing method is characterized by pressing so that the branch pipe support part (15) is inclined with respect to the inner pipe support part (13). It is a manufacturing method of the double pipe according to claim 6 or 7,
A method of manufacturing a double pipe, wherein the branch pipe support part (15) is pressed so as to have a larger diameter than the inner pipe support part (13). It is a manufacturing method of the double pipe according to any one of claims 5 to 8,
In the brazing step, the outer pipe is supplied while supplying the brazing material (111) to the upper pipe in a state where one of the inner pipe (12) and the branch pipe (16) is arranged upward and the other is arranged downward. (11) A method of manufacturing a double pipe, characterized in that a joint portion between the inner pipe (12) and the branch pipe (16) is brazed. It is a manufacturing method of the double pipe according to any one of claims 5 to 8,
In the brazing step, the brazing material (111) is placed on the upper pipe in the state where the large-diameter pipe of the inner pipe (12) and the branch pipe (16) is arranged above and the small-diameter pipe is arranged below. A method of manufacturing a double pipe, wherein a joint portion of the outer pipe (11), the inner pipe (12) and the branch pipe (16) is brazed while being supplied.

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