JP2005256911A - Structure of branching portion of double pipe and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure of a branch portion of a double pipe, capable of preventing the generation of chatter noise caused by intermittent contacts between an outer pipe and an inner pipe due to vibration. <P>SOLUTION: An end portion 11b of the outer pipe 11 is formed so as to have a cross section in a shape of glasses or a snowman-silhouetted cross section, including a roughly cylindrical inner pipe support portion 13 for supporting the inner pipe 12 and a roughly cylindrical branch pipe support portion 15 for supporting a branch pipe 16. The inner pipe 12 and the branch pipe 16 are brazed on the end portion 11b in the state where the inner pipe 12 and the branch pipe 16 are inserted into the end portion 11b. The inner pipe support portion 13 is located more on the inner peripheral side than a general portion 11a of the outer pipe 11 in a projection figure in the direction along general portion 11a of the outer pipe 11. Therefore, the inner pipe 12 supported by the inner pipe support portion 13 of the outer pipe 11 is surely separated from the inner peripheral surface of the outer pipe 11. Thus, the generation of chatter noise caused by intermittent contacts between the outer pipe 11 and the inner pipe 12 is prevented even when a double pipe 1 vibrates. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a structure of a branch portion of a double pipe in which an inner pipe is passed through an outer pipe and a manufacturing method thereof.

There is a double pipe in which an inner pipe is provided inside the outer pipe so that a double flow path can be obtained. The use of such a double pipe is advantageous when the pipe layout is greatly limited because the pipe layout can be made simple and compact. This is particularly advantageous when the piping layout is largely limited by the vehicle body structure or the like, such as a vehicle air conditioner. In addition, when the double pipe is used, the assembly work of the air conditioner is simplified, and the manufacturing cost can be reduced.
JP 58-121394 A

  Such a double pipe requires a structure for branching the inner pipe and the outer pipe, and there is a structure disclosed in Patent Document 1 as a structure of a branch portion of the double pipe. The structure of the branch part of the double pipe of Patent Document 1 is a structure in which the end part of the outer pipe is expanded and the inner pipe and the connecting pipe are inserted. For this reason, the inner tube is in contact with the inner peripheral surface of the general portion of the outer tube, or the inner tube is in contact with the inner tube, so that when the double tube is placed on a vibrating body such as a vehicle, the inner tube As the tube or the outer tube vibrates, there is a possibility that the inner tube and the outer tube are intermittently contacted to generate chatter noise.

  In view of the above circumstances, an object of the present invention is to provide a structure of a branch portion of a double pipe that can prevent chatter noises due to intermittent contact between an outer pipe and an inner pipe due to vibration, and a method for manufacturing the same. To do.

  According to the first aspect of the present invention, an inner tube and a branch tube are provided at the end of an outer tube having a substantially cylindrical inner tube support portion for supporting the inner tube and a substantially cylindrical branch tube support portion for supporting the branch tube. The inner pipe support portion is a structure of the branch portion of the double pipe brazed in a state where the inner pipe is inserted, and the inner pipe support portion is formed in the projection of the general portion of the outer pipe. It is located inside the peripheral surface.

  The invention of claim 2 is the structure of the branch part of the double pipe according to claim 1, wherein the end part of the outer pipe is connected to the inner pipe support part and the branch pipe support part via a joint part. It is provided independently and has a cross-sectional glasses shape.

  The invention of claim 3 is the structure of the branch portion of the double pipe according to claim 1, wherein the end portion of the outer tube is provided with the inner tube support portion and the branch tube support portion communicating with each other. Thus, the cross-section is substantially daruma-shaped.

  Invention of Claim 4 is a structure of the branch part of the double pipe of any one of Claims 1-3, Comprising: The terminal is a taper shape in the said inner pipe support part and the said branch pipe support part. It is characterized by being expanded.

According to the invention of claim 5, the end portion of the outer tube is processed into a cross-sectional glasses shape or a cross-shaped dart shape having a cylindrical inner tube support portion and a cylindrical branch tube support portion, and the end portion of the outer tube In the projection, the inner tube support portion is positioned inside the inner peripheral surface of the general portion of the outer tube in the projection view along the extending direction of the general portion of the outer tube,
Joining the outer tube, the inner tube, and the branch tube with the inner tube inserted into the outer tube through the inner tube support portion of the outer tube and the branch tube inserted into the branch tube support portion of the outer tube It is characterized by brazing the part.

Invention of Claim 6 is a manufacturing method of the branch part of the heavy pipe of Claim 5, Comprising: The edge part process of the said outer pipe | tube is as follows.
A bending step of bending the end of the outer tube before processing;
A pressing step of processing the end portion of the curved outer tube from a radial direction by a press mold into a cross-sectional glasses shape or a cross-sectional shape having the inner tube support portion and the branch tube support portion;
It is characterized by providing.

Invention of Claim 7 is a manufacturing method of the branch part of the double pipe of Claim 5, Comprising: The edge part process of the said outer pipe | tube is as follows.
In the end portion of the outer tube before processing, a punch step for decentering the end portion of the outer tube with respect to the general portion by pressing a rod-shaped punch having an inclined surface at the tip, and
A pressing step in which the end portion of the eccentric outer tube is sandwiched from the radial direction with a press die and is processed into a cross-section glasses shape or a cross-section shape having the inner tube support portion and the branch tube support portion;
It is characterized by providing.

Invention of Claim 8 is the manufacturing method of the branch part of the double pipe | tube of Claim 6 or Claim 7, End part processing of the said outer pipe | tube is carried out,
The method further comprises a step of expanding the end of the inner tube support portion and the branch tube support portion in a tapered shape after the pressing step.

  According to the structure of the branch part of the double pipe of the invention of claim 1, the inner pipe support part of the outer pipe is located on the inner diameter side from the inner peripheral surface of the general part of the outer pipe. The inner tube supported by the support portion 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 can be prevented from coming into contact and generating chatter noise.

  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 1, the inner pipe support part and the branch pipe support part are provided in communication with each other, so The constricted part can be abolished. Therefore, it becomes easy to press the Daruma-shaped opening. In addition, depending on the direction of the press working, a daruma-shaped opening having an inner pipe support part and a branch pipe support part may be provided once while the inner pipe support part is positioned on the inner diameter side of the inner peripheral surface of the general part of the outer pipe. There is also an advantage that can be processed with the press.

  According to the invention of claim 4, in addition to the effect of the invention of any one of claims 1 to 3, the inner pipe support part and the branch pipe support part are widened in a tapered shape, so that the manufacturing process In this case, the placement stability of the brazing material disposed at the open ends of both support portions is enhanced, and the brazing process is simplified.

  According to the manufacturing method of the branch part of the double pipe of the invention of claim 5, in the manufactured double pipe, the inner pipe support part at the end of the outer pipe is on the inner diameter side from the inner peripheral surface of the general part of the outer pipe. Will be located. 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 come into contact with each other and chatter noise is generated. Can be prevented.

  According to the invention of claim 6, in addition to the effect of the invention of claim 5, the end portion of the outer tube can be processed with relatively few steps. The bending step can be performed by pressing from the radial direction of the outer tube with a press die or bending with a bender.

  According to the invention of claim 7, in addition to the effect of the invention of claim 5, the end portion of the outer tube can be processed with relatively few steps. In addition, since it is possible to expand the end of the outer tube in the punching process, it is possible to increase the diameter size of the inner tube and the branch tube supported on the end of the outer tube.

  According to the invention of claim 8, in addition to the effect of the invention of claim 6 or 7, it becomes easy to place the brazing material at the opening ends of both support portions, and the brazing process is simplified by the placement stability of the brazing material. To do.

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

  1st Embodiment: FIGS. 1-9 shows 1st Embodiment of this invention.

"Overall structure of double pipe"
FIG. 1 is a perspective view showing a use state in which a joint is attached to the double pipe of the first embodiment to which the structure of the branch section of the double pipe of the present invention is applied, and FIG. 2 is a branch section of the double pipe of the present invention. It is a perspective view which shows the double tube of 1st Embodiment to which this structure is applied. The double tube 1 includes an outer tube 11 and an inner tube 12 as shown in FIGS. The inner pipe 12 flows the first fluid L1 (indicated by an arrow in FIGS. 1 and 2), and is between the outer pipe 11 and the inner pipe 12 (between the inner peripheral surface of the outer pipe 11 and the outer peripheral surface of the inner pipe 12). The second fluid L2 (indicated by an arrow in FIGS. 1 and 2) can flow through the passage between the two. The flow directions of the first fluid L1 and the second fluid L2 in FIGS. 1 and 2 are examples. In the double pipe 1, the outer pipe and the inner pipe are not integrally formed through ribs as in the conventional case (see, for example, JP-A-2002-228072). The outer tube 11 is manufactured by combining a small diameter tube (inner tube 12). More specifically, the outer tube 11 and the inner tube 12 are connected in a state where the inner tube 12 is passed through the outer tube 11 through two cylindrical inner tube support portions 13 and 14 processed into the outer tube 11. It is brazed. Since both the inner tube support portions 13 and 14 are located on the inner diameter side of the general portion 11a of the outer tube 11 in the projection plane view along the axial direction of the outer tube 11, they are supported by both the inner tube support portions 13 and 14. The inner tube 12 is separated from the inner peripheral surface of the outer tube 11. For this reason, it is prevented that the double tube vibrates and the outer tube 11 and the inner tube 12 come into contact intermittently.

  Here, in order to connect separate pipes to the inner pipe 12 and the outer pipe 11 at both ends of the double pipe 1, branch structures 1b and 1c are necessary.

  In the branch part 1b on the one end side of the double pipe 1, the end part 11b of the outer pipe 11 is provided with two cylindrical parts 13 and 15 and is processed into a cross-sectional glasses shape. The inner tube 12 passes through the portion 13), and the branch tube 16 is connected and supported by the other cylindrical portion (branch tube support portion 15). Thereby, the branch part 1b of the one end side of the double pipe 1 is formed.

  In the branch portion 1c on the other end side of the double tube 1, the outer tube 11 is curved and formed in an L shape, and the cylindrical inner tube support portion 14 is drilled or burred on the L shaped curved portion 11c. The inner tube 12 penetrates the outer tube 11 through the inner tube support portion 14. Thereby, the branch part 1c on the other end side of the double pipe 1 is formed.

"Branch structure"
Since this embodiment is characterized by the structure of the branch portion 1b on one end side of the double tube 1, the structure of the branch portion 1b on one end side will be described in more detail below.

  In the branch part 1b on the one end side of the double pipe 1, the end part 11b of the outer pipe 11 includes an independent cylindrical inner pipe support part 13 (not necessarily cylindrical in the present invention) and a cylindrical branch pipe. It has a support portion 15 (not necessarily cylindrical in the present invention). The inner tube 12 is brazed to the inner tube support portion 13 in a state where the inner tube 12 is supported through, and the branch tube 16 is brazed to the branch tube support portion 15 in a state where the branch tube 16 is connected 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 joint portion 17 formed of two stacked flat plates. Thus, the end portion 1b of the outer tube 11 is formed in a spectacle shape in cross section at a predetermined length.

  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. The branch pipe support 15 may be smaller in diameter than the inner pipe support 13, or the branch pipe support 15 may be larger in diameter than the general part 11 a of the outer pipe 11. 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.

  The opening ends 13b and 15b of the inner tube support portion 13 and the branch tube support portion 15 are formed in a flared shape as shown in FIG. 8, and as a result, as shown in FIG. When the ring-shaped brazing material 20 is disposed at the opening terminals 13b and 15b with the branch pipe support portion 15 and the outer pipe 11, the inner pipe 12 and the branch pipe 16 are brazed and fixed, the brazing material 20 is stably disposed. It has come to improve.

"Manufacturing method of branch part"
Next, the manufacturing method of the branch part 1b is demonstrated with reference to FIGS.

  The manufacturing process of the branch portion 1b is roughly divided into an “end portion processing step” in which the end portion 11b of the outer tube 11 is processed into a predetermined shape, and the inner tube 12 and the branch tube 16 are inserted and brazed after this end portion processing. The “brazing process”.

"End machining process"
(I) First, as shown in FIGS. 3 to 4, the end portion 11 b of the outer tube 11 is pressed into the end portion of the linear outer tube 11 before processing to press the end portion 11 b of the outer tube 11 into the general portion 11 a of the outer tube 11. Is decentered while being curved (FIG. 4). As shown in FIG. 4, a part X of the deformed end portion 11 b of the outer tube 11 is formed in parallel with the general portion 11 of the outer tube 11 and is projected along the extending direction of the general portion 11 a of the outer tube 11. 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 of the outer tube 11.

  Here, the punch 22 is generally 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.

  (Ii) Next, as shown in FIG. 5 to FIG. 6, in a state where the two core bars 24 and 25 are inserted into the end portion 11b of the eccentric outer tube 11, the outer tube end portion 11b is moved from the radial direction. The mold surface 26b of the press die 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.

  (Iii) Next, as shown in FIG. 7, the end portion 11b having the cross-section glasses is held by the clamp 28, and the opening ends 13b and 15b of the inner tube support portion 13 and the branch tube support portion 15 are expanded punches. 29 and 30 expand in a tapered shape. Here, tapered inclined surfaces 29b and 30b are formed at the tips of the circular expansion punches 29 and 30, and the tapered inclined surface is formed at the opening end of the outer tube holding hole 31 of the clamp 28. 32 is formed.

  Through the steps (i), (ii), and (iii), the outer tube 11 has a shape as shown in FIG. In addition, before or after the processing of the end portion 11b on the one end side of the outer tube 11, the end portion 11c on the other end side of the outer tube 11 is bent into an L shape so that the L-shaped bending portion 11c is formed. The cylindrical inner tube support 14 is drilled or burred (see FIG. 9). The inner tube support portion 14 and the inner tube support portion 13 are provided on a straight line. In this example, the inner tube support portion 14 protrudes from the inner side of the outer tube 11. However, in the present invention, the inner tube support portion 14 protrudes from the outer tube 11. Also good.

"Brazing process"
Then, as shown in FIG. 9, the straight inner tube 12 is passed through the outer tube 11 through both inner tube support portions 13 and 14 of the outer tube 11, and the branch tube 16 is inserted into the branch tube support portion 15. Further, the brazing material 20 is disposed at the end of each support portion 13, 14, 15 and heated to a predetermined temperature in this state to fix the outer tube 11, the inner tube 12 and the branch tube 16 to each other, and to support each support portion 13. , 14 and 15 are sealed with a molten brazing material 20. Thereby, the double tube 1 as shown in FIGS. 2 and 9 is obtained.

"effect"
Next, effects of the first embodiment will be described.

  According to the structure of the branch part 1b of the double pipe 1 of the first embodiment, first, the inner pipe support part 13 is located closer to the inner diameter side than the inner peripheral surface of the general part 11a of the outer pipe 11. The inner tube 12 supported by the inner tube support portion 13 of the outer tube 11 is reliably separated from the inner peripheral surface of the outer tube 11. Therefore, even if the double tube 1 vibrates, it is possible to prevent the chatter noise from being generated due to the contact between the inner tube 12 and the outer tube 11.

  Second, since the adjacent inner tube support portion 13 and the branch tube support portion 15 are provided independently, the one end portion 11b of the outer tube 11 becomes an eyeglass-shaped opening, that is, the inner tube 12 and the branch tube. Since 16 is supported by independent cylindrical support portions 13 and 15, the support is stable compared to a structure in which the cylindrical support portions 13 and 15 communicate with each other (for example, fifth and sixth embodiments described later). Excellent in properties.

  Thirdly, since the opening ends 13b and 15b of the inner tube support portion 13 and the branch tube support portion 15 are expanded in a flared shape, the brazing material 20 is attached to the opening ends 13b and 15b of the both support portions 13 and 15. Easy to place. Thereby, the placement stability of the brazing material 20 in the brazing process is increased, and the manufacturing process is simplified.

  Moreover, according to the manufacturing method of the branch part 1b of the double pipe 1 of this 1st Embodiment, the edge part process of the outer tube 11 is the outer pipe | tube 11 before processing the rod-shaped punch 22 provided with the inclined surface 22b at the front-end | tip. A punching process in which the end portion 11b of the outer tube 11 is eccentric with respect to the general portion 11a by press-fitting into the end portion, and the end portion 11b of the eccentric outer tube 11 is sandwiched from the radial direction by a press die 26. Since it has a pressing process in the shape of glasses, there is an advantage that the end portion 11b of the outer tube 11 can be processed with relatively little processing. Moreover, since it is possible to expand the end portion 11b of the outer tube 11 with the punch 22, the diameter sizes of the inner tube 12 and the branch tube 16 supported by the end portion 11b of the outer tube 11 can be set large. Design flexibility increases.

  Hereinafter, other embodiments of the present invention will be described. In addition, about the structure which is the same as that of 1st Embodiment, or similar, the same code | symbol is attached | subjected and the description of the structure and effect is abbreviate | omitted.

Second Embodiment: In the first embodiment described above, the structures of the branch portions 1b and 1c on the one end side and the other end side of the double tube 1 are different. In the present invention, the second embodiment shown in FIG. As in the embodiment, the branch portions 1b and 1c on both ends of the double tube 1B may have an equivalent structure. Also in the second embodiment, the same operational effects as in the first embodiment can be obtained.

  Third Embodiment: In the first embodiment described above, in the method of manufacturing the branch portion 1b of the double pipe 1, the end portion 11b of the outer pipe 11 before processing is eccentrically formed by the punch 22 as shown in FIGS. However, the end portion 11b of the outer tube 11 is bent by a predetermined angle θ with respect to the general portion 11a of the outer tube 11 by, for example, a press or a bender from the radial direction of the outer tube 11 to be eccentric. It may be.

  Since an existing bender can be used in such a bending process, it is not necessary to use a special processing apparatus (the die 21 and the punch 22) as shown in the first embodiment, and the end portion of the outer tube is relatively low cost. There is an advantage that can be processed.

  Fourth Embodiment: In the structure of the branch portion 1b of the double pipe 1 of the first embodiment described above, the branch pipe support portion 15 is inclined with respect to the inner pipe support portion 13. As in the double pipe 1D shown in FIG. 15, the inner pipe support 13 and the branch pipe support 15D may be arranged in parallel. Here, FIG. 12 to FIG. 14 are diagrams for supplementarily explaining the process when the inner pipe support part 13 and the branch pipe support part 15D are processed in parallel, but include the same manufacturing process as in the first embodiment. Description is omitted. 12 corresponds to FIG. 4 of the first embodiment, FIG. 13 corresponds to FIG. 5 of the first embodiment, and FIG. 14 corresponds to FIG. 6 of the first embodiment. Reference numeral 21D indicates a die, reference numeral 25D indicates a cored bar, and reference numeral 26D indicates a press die.

  Fifth Embodiment: In the first embodiment described above, the end portion 11b of the outer tube 11 is formed in the shape of a cross-sectional eyeglass by independent cylindrical support portions 13 and 15, but in the present invention, As shown in the double pipe 1E shown in FIG. 20, the inner pipe support part 13E and the branch pipe support part 15E may be communicated to form a cross section. FIG. 21 is a perspective view of the branch pipe 16 </ b> E, in which a concave portion 37 matching the shape of the inner pipe 12 is provided at the contact portion with the inner pipe 12. In the fifth embodiment, the inner tube support portion 13E and the branch tube support portion 15E are provided in parallel. 16 to 19 are diagrams for supplementarily explaining the process when the end portion 11b of the outer tube 11 is processed to have a cross section, but the description is omitted because it is the same manufacturing process as in the first embodiment. . 16 corresponds to FIG. 3 of the first embodiment, FIG. 17 corresponds to FIG. 4 of the first embodiment, FIG. 18 corresponds to FIG. 5 of the first embodiment, and FIG. This corresponds to FIG. In the figure, reference numeral 21E denotes a die, reference numeral 22E denotes a punch, reference numeral 33 denotes a cored bar, and reference numeral 35 denotes a die surface of the press mold 26E. Unlike the first embodiment, the cross-sections of the core metal 33 and the mold surface 35 are each formed in a daruma shape combining two circles.

  Sixth Embodiment: Similarly to the fifth embodiment, even in the structure in which the end 11b of the outer tube 11 is formed in the shape of a cross section, like the double tube 1F of the sixth embodiment shown in FIG. The branch pipe 16F may be inclined with respect to the inner pipe 12. FIG. 22b is a perspective view showing the relationship of the contact portion between the branch pipe 16F and the inner pipe 12.

  Seventh Embodiment: In the method for manufacturing the double pipe 1 of the first to sixth embodiments described above, the step of processing the end portion 11b of the outer pipe 11 into a glass shape or a daruma shape is performed by punching and pressing. However, it may be formed by one press working with the press die 26G as in the seventh embodiment shown in FIG. When there is no constricted portion in the shape of the end portion 11b of the outer tube 11 to be processed as in the seventh embodiment, the end portion 11b of the outer tube 11 can be processed into a circular cross section 13E, 15E by a single press process.

  In short, according to the present invention, since the inner tube support portion is located on the inner diameter side of the inner peripheral surface of the general portion of the outer tube, the inner tube supported by the inner tube support portion of the outer tube is reliably removed. Separate from the outer peripheral surface of the tube. Therefore, even if the double pipe vibrates, it can be prevented that the inner pipe and the outer pipe are in contact with each other and chatter noise is generated.

The perspective view which shows the use condition of the double pipe to which the structure of the branch part of the double pipe of 1st Embodiment is applied. The perspective view which shows the double pipe to which the structure of the branch part of the double pipe of 1st Embodiment is applied. Among explanatory drawings explaining the manufacturing method of the branch part of the double pipe of 1st Embodiment, it is a figure which shows the state before the punch process which decenters the edge part of an outer pipe, (a) is a side view, (B) is a top view. Among explanatory drawings explaining the manufacturing method of the branch part of the double pipe of 1st Embodiment, it is a figure which shows the punch process which decenters the edge part of an outer pipe, (a) is a side view, (b) is Top view. It is a figure which shows the state before the press process which presses the edge part of the eccentric outer tube among explanatory drawings explaining the manufacturing method of the branch part of the double tube of 1st Embodiment, (a) is a side surface FIG. 4B 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 the branch part of the double pipe of 1st Embodiment, (a) is a side view, (b) ) Is a top view. Among explanatory drawings explaining the manufacturing method of the branch part of the double pipe of 1st Embodiment, it is a figure which shows the punch process which punches to expand the opening terminal of an inner pipe support part and a branch pipe support part, a) Side view, (b) Top view. It is a figure which shows the shape of the one end part of the outer pipe | tube which finished the edge part process among the explanatory drawings explaining the manufacturing method of the branch part of the double pipe of 1st Embodiment, (a) is a top view, b) is a cross-sectional view along the longitudinal direction of the outer tube. Sectional drawing which follows the longitudinal direction of the outer tube | pipe which shows the brazing process among explanatory drawings explaining the manufacturing method of the branch part of the double tube | pipe of 1st Embodiment. The perspective view which shows the double tube of 2nd Embodiment. It is explanatory drawing explaining the manufacturing method of the branch part of the double tube of 3rd Embodiment, Comprising: The figure which shows the bending process which decenters the edge part of an outer tube. Among explanatory drawings explaining the manufacturing method of the branch part of the double pipe of 4th Embodiment, it is a figure which shows the punch process which decenters the edge part of an outer pipe, (a) is a side view, (b) is Top view. Among explanatory drawings explaining the manufacturing method of the branch part of the double pipe of 4th Embodiment, 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 surface FIG. 4B is a top view. Among explanatory drawings explaining the manufacturing method of the branch part of the double pipe of 4th Embodiment, it is a figure which shows the press process which presses the edge part of the eccentric outer pipe, (a) is a side view, (b ) Is a top view. Sectional drawing which follows the longitudinal direction of the outer tube | pipe which shows the structure of the branch part of the double tube | pipe of 4th Embodiment. Among explanatory drawings explaining the manufacturing method of the branch part of the double pipe of a 5th embodiment, it is a figure showing the state before the punching process which decenters the end of an outer pipe, and (a) is a side view, (B) is a top view. Among explanatory drawings explaining the manufacturing method of the branched part of the double pipe of 5th Embodiment, it is a figure which shows the punch process which decenters the edge part of an outer pipe, (a) is a side view, (b) is Top view. Among explanatory drawings explaining the manufacturing method of the branched part of the double pipe of 5th Embodiment, 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 surface FIG. 4B is a top view. Among explanatory drawings explaining the manufacturing method of the branched part of the double pipe of 5th Embodiment, it is a figure which shows 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 structure of the branch part of the double pipe of 5th Embodiment, (a) is sectional drawing in alignment with the longitudinal direction of an outer pipe | tube, (b) is a top view. The perspective view which shows partially the shape of the branch pipe used for the structure of the branch part of the double pipe of 5th Embodiment. It is a figure which shows the structure of the branch part of the double pipe of 6th Embodiment, (a) is sectional drawing in alignment with the longitudinal direction of an outer pipe, (b) is a perspective view which shows the contact state of an inner pipe and a branch pipe Figure. It is explanatory drawing explaining the manufacturing method of the branch part of the double pipe of 7th Embodiment, Comprising: The end part of the outer pipe | tube before a process is a cross-sectional darling shape which has an inner pipe support part and a branch pipe support part by one press. The process which processes to the edge part of this.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1B, 1D, 1E, 1F ... Double pipe 1b ... Branching part 11 ... Outer pipe 11a ... General part 11b ... End part 12 ... Inner pipe 13, 13E ... Inner pipe support part 13b ... Opening terminal 15, 15D, 15E ... branch pipe support part 16, 16E, 16F ... branch pipe 17 ... joint part 18 ... inclined part 20 ... brazing material 22, 22E ... punch 22b ... inclined surface 26, 26D, 26E ... press die 29 ... expansion punch

Claims (8)

A substantially cylindrical inner tube support portion (13, 13E) for supporting the inner tube (12) and a substantially cylindrical branch tube support portion (15, 15D, 15E) for supporting the branch tubes (16, 16E, 16F); The double pipe (1, 1B, 1D, 1E) brazed with the inner pipe (12) and the branch pipe (16, 16E, 16F) inserted into the end (11b) of the outer pipe (11) having 1F) of the branch (1b),
The inner tube support portions (13, 13E) are located on the inner side of the general portion (11a) of the outer tube (11) in a projection view along the extending direction of the general portion (11a) of the outer tube (11). The structure of the branch part (1b) of the double pipe (1, 1B, 1D, 1E, 1F) characterized by the above-mentioned. It is the structure of the branch part of the double pipe according to claim 1,
The end portion (11b) of the outer tube (11) has a cross section in which the inner tube support portion (13) and the branch tube support portion (15, 15D) are provided independently via a joint portion (17). The structure of the branch part (1b) of the double pipe (1, 1B, 1D) characterized by being in the form of glasses. It is the structure of the branch part of the double pipe according to claim 1,
The end portion (11b) of the outer pipe (11) has a substantially darling cross section when the inner pipe support portions (13E, 13F) and the branch pipe support portions (15E, 15F) are provided in communication with each other. The structure of the branch part (1b) of the double pipe (1E, 1F) characterized by these. It is the structure of the branch part of the double pipe according to any one of claims 1 to 3,
The inner tube support portion (13) and the branch tube support portion (15) have branch ends (12) of the double tube (1) characterized in that open terminals (13b, 15b) are expanded in a tapered shape. The structure of 1b). The end portion (11b) of the outer tube (11) has a cross-sectional glasses shape or a cross-drum shape having a cylindrical inner tube support portion (13, 13E) and a cylindrical branch tube support portion (15, 15D, 15E). In the projection view along the extending direction of the general portion (11a) of the outer tube (11), the inner tube support portion (13, 13E) is processed into the end portion of the outer tube. It should be located inside the general part (1a)
The inner pipe (12) is inserted into the outer pipe (11) through the inner pipe support parts (13, 13E) of the outer pipe (11) and the branch pipe support parts (15, 15D, 15E) of the outer pipe (11). ), With the branch pipes (16, 16E, 16F) inserted, the joints of the outer pipe (11), the inner pipe (12), and the branch pipes (16, 16E, 16F) are brazed. The manufacturing method of the branch part (1b) of the double pipe (1, 1B, 1D, 1E, 1F) characterized by the above-mentioned. It is a manufacturing method of the branch part of the double pipe according to claim 5,
End processing of the outer tube is
A bending step of bending the end (11b) of the outer tube (11) before processing;
The end (11b) of the curved outer tube (11) is sandwiched from the radial direction by a press die (26, 26D, 26E), and the inner tube support portion (13, 13E) and the branch tube support portion (15, 15D, 15E) a pressing step for processing into a cross-section glasses or a cross-section dart;
The manufacturing method of the branch part of a double pipe characterized by comprising. It is a manufacturing method of the branch part of the double pipe according to claim 5,
End processing of the outer tube is
The end (11b) of the outer tube (11) is pressed by pressing a rod-shaped punch (22, 22E) having an inclined surface (22b) at the tip into the end (11b) of the outer tube (11) before processing. ) Is eccentric with respect to the general part (11a),
A pressing step in which the end portion (11b) of the eccentric outer tube (11) is sandwiched from the radial direction by a press die (26, 26D, 26E) to form a cross-section glass shape or a cross-section dart shape;
The manufacturing method of the branch part of a double pipe characterized by comprising. In the manufacturing method of the branch part of the double pipe according to claim 6 or 7,
End processing of the outer tube is
A double pipe characterized by further comprising a step of expanding the opening ends (13b, 15b) of the inner pipe support portion (13) and the branch pipe support portion (15) in a tapered shape after the pressing step. Manufacturing method of the branch part.

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