JP2007177848A - Piping - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide piping facilitating positioning of a small diameter pipe with respect to a pipe and capable of preventing a jointing material from being flowed in inside of the pipes at the time of jointing of the both pipes. <P>SOLUTION: This piping is provided with the pipe 110 having a burring 113 formed so as to surround an opening 112 provided on a pipe wall 111 and to project outwardly; the small diameter pipe 120 having, at a tip, a flange part 121 formed so as to expand along the outer face of the pipe wall 111 outside the burring 113, covered with the burring 113 and communicating with the pipe 110 via the opening 112 inside the burring 113; and the joint material for jointing a space between the pipe wall 111 and the flange part 121. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pipe having one pipe and a small-diameter pipe branched from the pipe, and is suitable for use in, for example, a double pipe having an inner pipe and an outer pipe.

Conventionally, as a pipe having a small-diameter pipe branched from one pipe, for example, one shown in Patent Document 1 is known. This pipe is applied to a double pipe heat exchanger having an outer pipe and an inner pipe, and a branch guide pipe (small diameter pipe) is provided on the outer pipe (one pipe). That is, a branch opening that is a simple round hole is formed on the outer peripheral wall (branch connection portion) of the outer tube, and an abutting portion (so-called flange portion) is formed on one end side of the branch guide tube. Then, an abutting portion is connected (joined) around the branching opening to form a pipe.
JP 2002-318083 A

  However, in the above piping, when the outer pipe and the branch guide pipe are joined, the flange portion can be arbitrarily arranged (set) on the outer peripheral wall of the outer pipe with respect to the branch opening, and the branch opening When the branch guide pipe is set from above, the branch opening is hidden by the flange portion and cannot be visually observed. Therefore, it is difficult to align the center positions of the branch opening and the branch guide pipe. When the branch guide tube is joined to the branching opening so that the flange portion straddles the branching opening due to the position shift at this time, the joining area is reduced and the joining strength is lowered. Further, in the joint portion, the branch connection portion and the flange portion are formed such that the flat plates overlap each other, so that the joining material may flow into the pipe at the time of joining.

  In view of the above problems, an object of the present invention is to provide a pipe that facilitates the positioning of a small-diameter pipe with respect to the pipe and prevents the joining material from flowing into the pipe when the two pipes are joined.

  In order to achieve the above object, the present invention employs the following technical means.

  According to the first aspect of the present invention, in the pipe, the pipe (110) formed with the burring (113) projecting outwardly surrounding the opening (112) provided in the pipe wall (111), and the burring at the tip A flange portion (121) extending along the outer surface of the outer tube wall (111) of (113) is formed, and the tube portion (110) is placed over the burring (113) and through the opening (112) in the burring (113). ), And a joining material that joins between the pipe wall (111) and the flange portion (121).

  Thereby, when joining a pipe | tube (110) and a small diameter pipe | tube (120), a small diameter pipe | tube (130) can be easily positioned with a burring (113). Further, when joining the pipe (110) and the small diameter pipe (120), the burring (113) serves as a weir, and the joining material can be prevented from flowing into the pipe (110).

  In the invention according to claim 2, the small diameter pipe (120) has a large diameter part (122) for accommodating the burring (113) and a small diameter part (123) smaller than the outer diameter of the large diameter part (122). It is characterized by that.

  Accordingly, the inner diameter of the burring (113) and the inner diameter of the small diameter portion (120) can be made closer to each other, and the step between them can be reduced, so that the fluid flowing through the burring (113) and the small diameter portion (120) It is possible to reduce the distribution resistance.

  The invention according to claim 3 is characterized in that the small diameter portion (123) has an inner diameter substantially equal to the inner diameter of the burring (113) and extends long.

  As a result, the step between the inner diameter of the burring (113) and the inner diameter of the small diameter portion (120) can be made substantially zero, and further, the flow resistance of the fluid flowing through the burring (113) and the small diameter portion (120). Can be reduced.

  The invention according to claim 4 is characterized in that a stepped portion (124) is formed between the large diameter portion (122) and the small diameter portion (123).

  Thereby, a small diameter pipe (120) can be formed without failure.

  As in the invention described in claim 5, the joining material can be a brazing material.

  In the invention according to claim 6, the pipe (110) is an outer pipe (110) of a double pipe (10) in which an inner pipe (130) and an outer pipe (110) are arranged in an inner and outer double. It is characterized by that.

  In the double pipe (10), it is necessary to set a branch pipe in the outer pipe (110), which is preferable using the present invention.

  The invention according to claim 7 is characterized in that a spiral groove (132) is formed in the inner tube wall (131) of the inner tube (130).

  Thereby, since the cross-sectional area of the internal / external flow path (10a) between the outer pipe (110) and the inner pipe (130) can be enlarged by the spiral groove (132), the internal / external flow path (10a) The flow resistance of the flowing fluid can be reduced. Therefore, the flow rate of the fluid flowing through the inner-outer flow path (10a) can be increased, and the heat exchange efficiency when heat exchange with the fluid flowing through the inner pipe (130) can be improved.

  Further, in the inner-outer flow path (10a), the spiral groove (132) can form a vortex flow (turbulence of flow) due to the spiral flow with respect to the original flow in the longitudinal direction. It is possible to improve the heat exchange efficiency when performing heat exchange between the fluid flowing in the inner pipe (130) and the fluid flowing in the inner-outer flow path (10a).

  In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment description mentioned later.

(First embodiment)
The pipe 100 of the present embodiment is applied to the double pipe 10 disposed in the refrigeration cycle of the vehicle air conditioner. Hereinafter, a specific configuration will be described with reference to FIGS. 1 and 2. To do. 1 is a cross-sectional view showing the entire double tube 10, and FIG. 2 is a cross-sectional view showing a portion II in FIG.

  The double pipe 10 has a total length of about 700 to 900 mm, and in order to avoid interference with the vehicle engine and other equipment, the body, etc., the double pipe 10 has a plurality of bends with respect to the straight pipe portion that extends straight. A portion (not shown) is formed and mounted in the vehicle engine room.

  As shown in FIGS. 1 and 2, the double pipe 10 includes a pipe 100 including an outer pipe (corresponding to a pipe in the present invention) 110 and two liquid pipes (corresponding to a small diameter pipe in the present invention) 120, and an outer pipe. 110 and an inner tube 130 inserted into 110.

  The outer tube 110 is, for example, an aluminum φ22 mm tube (outer diameter 22 mm, inner diameter 19.6 mm). After the longitudinal direction both ends (henceforth, edge part) 114 of the outer tube | pipe 110 are combined with the inner tube | pipe 130, the perimeter is shrink | contracted toward radial inside, and also the circumferential wall surface 131 of the inner tube | pipe 130 is further reduced. (As will be described later, the outer diameter is 19.1 mm) and is brazed so as to be airtight or liquid-tight and formed as a joint 10b. Therefore, a space is formed between the outer tube 110 and the inner tube 130, and this space becomes the inner-outer flow path 10a.

  A circumferential wall surface (corresponding to the tube wall in the present invention) 111 adjacent to the end portion 114 of the outer tube 110 is provided with a hole (corresponding to the opening in the present invention) 112 that allows communication between the outside and the internal / external flow path 10a. A burring 113 projecting outward is provided around the hole 112 (two places).

  These burrings 113 can be formed by a mold shown in FIG. The mold includes an inner mold 201 and an outer mold 202. The inner mold 201 has a rod shape that can be inserted into the outer tube 110, and further has a shape that can move in the radial direction within the outer tube 110. The inner mold 201 is provided with a cylindrical protrusion corresponding to the inner shape of the burring 113. The outer mold 202 is provided with a recess for receiving the convex portion of the inner mold 201 and receiving the wall surface of the outer tube 110 between the inner mold 201 and the outer mold 202. In the molding process of the outer tube 110, first, a small hole is opened in the wall of the outer tube 110. Next, the inner mold 201 is pushed into the small holes from the inside of the outer tube 110, and the wall of the outer tube 110 surrounding the holes is deformed outward. As a result, a hole 112 is formed in the burring 113 protruding toward the outside of the outer tube 110.

  In order to process the burring 113, the position of the hole 112 is set to a position close to the edge of the outer tube 110. However, a width for caulking the outer tube 110 toward the inner tube 130 is provided between the edge of the outer tube 110 and the hole 112. The distance between the edge of the outer tube 110 and the hole 112 is set so that the brazing material between the outer tube 110 and the inner tube 130 does not flow into the hole 112. For example, a substantially complete cylindrical portion remains between the caulking portion that narrows the outer tube 110 radially inward and the burring 113. The axial length of the cylindrical portion is formed to be larger than the width of the flange portion 121 of the liquid pipe 120 described later, thereby enabling reliable joining.

  The burring 113 is provided with two aluminum liquid pipes 120 (corresponding to the small-diameter pipes in the present invention) that form high-pressure pipes of the refrigeration cycle. A flange portion 121 that extends in a circular shape along the circumferential wall surface 111 is formed at the tip of the liquid pipe 120 on the burring 113 side. The flange portion 121 is annularly provided at the end of the liquid pipe 120 and is curved along the circumferential wall surface 111. The liquid pipe 120 has a large-diameter portion 122 that accommodates the burring 113 on the flange portion 121 side. The inner diameter of the large diameter portion 122 is slightly larger than the outer diameter of the burring 113. The end of the liquid pipe 120 is put on the burring 113 of the outer pipe 110. In addition, the inner wall surface of the large-diameter portion 122 can at least partially contact the outer wall surface of the burring 113, and the liquid pipe 120 is reliably positioned on the burring 113. After the liquid pipe 120 is put on the burring 113, it is brazed (corresponding to the joining in the present invention). As a result, in the state where the burring 113 and the circumferential wall surface 111 surrounding the burring 113 are covered with the large diameter portion 122 and the flange portion 121 of the liquid pipe 120, the gap between them is a brazing material (the bonding material in the present invention). Corresponding) and both are joined.

  A small-diameter portion 123 having an outer diameter smaller than the outer diameter of the large-diameter portion 122 is extended on the side opposite to the flange portion of the large-diameter portion 122. A step portion 124 is formed between the large diameter portion 122 and the small diameter portion 123. Further, the inner diameter of the small diameter portion 123 is substantially equal to the inner diameter of the burring 113, and the diameter of the flow path along the flow direction between the hole 112 defined in the burring 113 and the inside of the liquid pipe 120 is the same. I try to suppress changes.

  One (left side in FIG. 1) liquid pipe 120 is connected to the condenser of the refrigeration cycle, and the other (right side in FIG. 1) liquid pipe 120 is connected to the expansion valve. A high-pressure refrigerant flows through the inter-channel 10a and the other liquid pipe 120.

  On the other hand, the inner tube 130 is, for example, an aluminum 3/4 inch tube (outer diameter 19.1 mm, inner diameter 16.7 mm), similar to the outer tube 110 described above. That is, the surface area of the inner tube 130 can be increased as close as possible to the outer tube 110 while ensuring a channel cross-sectional area (inner / outer channel 160a) through which the high-pressure refrigerant can flow in the inner / outer channel 10a. is doing.

  The circumferential wall surface (corresponding to the inner tube wall in the present invention) 131 of the inner tube 130 corresponding to the region where the inner / outer flow path 10a is formed is provided with the circumferential groove portion 133 and the spiral groove portion (the spiral groove in the present invention). 132) is provided. Circumferential groove 133 is a groove extending in the circumferential direction of inner tube 130 provided corresponding to the position of the connection between outer tube 110 and each liquid pipe 120. In addition, the spiral groove 132 is a multiple groove (here, three) that is connected to each of the circular grooves 133 and extends spirally in the longitudinal direction of the inner tube 130 between the circular grooves 133. The inner / outer flow path 160a is enlarged by the circumferential groove 133 and the spiral groove 132.

  One longitudinal end of the inner pipe 130 (left side in FIG. 1) is connected to the compressor of the refrigeration cycle, and the other longitudinal end (right side in FIG. 1) is connected to the evaporator. A low-pressure refrigerant flows in the pipe 130.

  Therefore, the double pipe 10 functions as a heat exchanger that exchanges heat between the high-pressure refrigerant that flows through the inner-outer flow path 10 a described above and the low-pressure refrigerant that flows through the inner pipe 130.

  In this embodiment, since the burring 113 is provided in the hole 112 of the outer pipe 110, the liquid pipe 130 can be easily positioned by the burring 113 when the outer pipe 110 and the liquid pipe 120 are brazed. it can. Therefore, the flange portion 121 does not cross the hole 112 due to the displacement, and the brazing can be reliably performed between the flange portion 121 and the circumferential wall surface 111, and the bonding strength of the liquid pipe 120 to the outer pipe 110 is sufficient. Can be secured.

  Further, when the outer pipe 110 and the liquid pipe 120 are brazed, the burring 113 serves as a weir, and the brazing material can be prevented from flowing into the outer pipe 110 from the hole 112. That is, the brazing material is not clogged in the hole 112 or the outer tube 110, and the flow resistance of the high-pressure refrigerant is not deteriorated.

  Further, in the liquid pipe 120, a large diameter portion 122 and a small diameter portion 123 are formed so that the outer diameter of the small diameter portion 123 is smaller than the outer diameter of the large diameter portion 122. Is substantially equal to the inner diameter of the burring 113, the step between the inner diameter of the burring 113 and the inner diameter of the liquid pipe 120 can be suppressed, and the flow resistance of the high-pressure refrigerant flowing through the burring 113 and the liquid pipe 120 can be reduced. Can be small.

  Since the step portion 124 is provided between the large diameter portion 122 and the small diameter portion 123, the liquid pipe 120 can be formed without failure.

  In addition, since the spiral groove 132 is formed on the circumferential wall surface 131 of the inner tube 130 as the double tube 10, the spiral groove 132 can enlarge the cross-sectional area of the inner / outer channel 10a, The distribution resistance of the circulating high-pressure refrigerant can be reduced. Therefore, the flow rate of the fluid flowing through the inner-outer flow path 10a can be increased, and the heat exchange efficiency when heat exchange with the low-pressure refrigerant flowing through the inner pipe 130 can be improved.

  Further, in the inner-outer flow path 10a, the spiral groove 132 can form a vortex flow (turbulence of flow) due to the spiral flow with respect to the original longitudinal flow, so that the heat transfer rate can be improved and the heat exchange described above The heat exchange efficiency when performing can be improved.

(Other embodiments)
In the first embodiment, the pipe 100 has been described as being applied to the double pipe 10. However, the present invention is not limited to this, and as illustrated in FIG. 4, a small-diameter pipe 120A that branches from the main pipe 110A in the refrigeration cycle. You may apply to the piping 100A which has. Furthermore, any pipe other than the refrigeration cycle can be widely applied as long as it is a pipe formed by joining a small-diameter pipe branched to a main pipe.

  Further, the setting of the small diameter portion 123 of the small diameter pipe (liquid pipe 120) and the diameter reduction of the small diameter section 123 may be unnecessary depending on the flow resistance of the fluid flowing through the inside. It is possible to prevent the bonding material from flowing in and positioning.

It is sectional drawing which shows the whole double pipe in 1st Embodiment. It is sectional drawing which shows the II section in FIG. It is sectional drawing of the type | mold for forming the burring part of 1st Embodiment. It is a front view which shows piping in other embodiment.

Explanation of symbols

10 Double pipe 100 Pipe 110 Outer pipe (pipe)
111 Circumferential wall (pipe wall)
112 hole (opening)
113 Burring 120 Liquid piping (small diameter pipe)
121 Flange part 122 Large diameter part 123 Small diameter part 124 Step part 130 Inner pipe 131 Circumferential wall surface (inner pipe wall)
132 Spiral groove (spiral groove)

Claims (7)

A pipe (110) formed with a burring (113) projecting outwardly surrounding an opening (112) provided in the pipe wall (111);
A flange portion (121) that extends along the outer surface of the tube wall (111) outside the burring (113) is formed at the tip, and the flange portion (121) extends over the burring (113) to cover the burring (113). A small diameter tube (120) communicating with the tube (110) through an opening (112);
Piping characterized by including the joining material which joins between the said pipe wall (111) and the said flange part (121). The small diameter pipe (120) includes a large diameter part (122) for accommodating the burring (113),
The pipe according to claim 1, further comprising a small-diameter portion (123) smaller than an outer diameter of the large-diameter portion (122).   The pipe according to claim 2, wherein the small diameter portion (123) has an inner diameter substantially equal to an inner diameter of the burring (113) and extends long.   The pipe according to claim 2 or 3, wherein a step portion (124) is formed between the large diameter portion (122) and the small diameter portion (123).   The piping according to claim 1, wherein the bonding material is a brazing material.   The said pipe | tube (110) is the said outer pipe | tube (110) of the double pipe | tube (10) formed by arrange | positioning an inner pipe | tube (130) and an outer pipe | tube (110) double inside and outside. The piping according to any one of claims 1 to 5.   The piping according to claim 6, wherein a spiral groove (132) is formed in the inner tube wall (131) of the inner tube (130).

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