JP2016080283A - Heat exchange tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the connection of a heat exchange tube.SOLUTION: A tube 10 comprises a pair of semi-cylindrical plates 20 connected to each other. Each of the plates 20 comprises a first connection wall part 21 and a second connection wall part 22 extending in parallel at both ends. The second connection wall part 22 comprises a stepped part 24 bent in the middle thereof. In the tube 10, the first connection wall part 21 of one of the plates 20 is engaged with the stepped part 24 of the other of the plates 20 and connected to the second connection wall part 22.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a heat exchange tube through which a fluid for heat exchange flows.

  Patent Document 1 discloses a heat transfer tube 100 shown in FIG. 6 as a heat exchange tube constituting a heat exchanger.

  The heat transfer tube 100 is formed into a flat cylindrical shape by assembling and brazing the semi-cylindrical upper case 110 and the lower case 120 together.

  The upper case 110 and the lower case 120 are each formed in a semi-cylindrical shape having a U-shaped cross section by pressing a metal plate. The opening width of the upper case 110 is formed larger than the opening width of the lower case 120. The lower case 120 is fitted and assembled inside the upper case 110.

JP 2010-243125 A

  However, in such a conventional heat transfer tube 100, when the lower case 120 is fitted and assembled in the upper case 110, a variation occurs in the gap C formed between the two fitting portions. There is a problem that the bonding between the two becomes poor.

  This invention is made | formed in view of said problem, and aims at making joining of a heat exchange tube favorable.

  According to an aspect of the present invention, there is provided a heat exchange tube through which a fluid for heat exchange flows, and includes a pair of semi-cylindrical plates joined to each other, each plate extending in parallel to both ends. It has a joining wall part and a 2nd joining wall part, the 2nd joining wall part has a step part bent in the middle, and the 1st joining wall part of one plate is a step part of the other plate A heat exchange tube is provided that is engaged with and joined to the second joining wall portion.

  According to the above aspect, the first joint wall portion and the second joint wall are formed by engaging the first joint wall portion of one plate and the stepped portion formed in the second joint wall portion of the other plate. The occurrence of a gap between the heat exchanger tube and the heat exchanger tube can be satisfactorily performed.

It is a perspective view which shows the state which decomposed | disassembled the core which concerns on embodiment of this invention. It is sectional drawing which shows the state which decomposed | disassembled the heat exchange tube. It is sectional drawing which shows a heat exchange tube. It is sectional drawing which shows a core. It is sectional drawing which shows a part of core. It is a disassembled perspective view which shows the heat exchanger tube which concerns on a prior art example.

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

  A core 1 shown in FIG. 1 constitutes an EGR cooler (heat exchanger) used in an EGR (Exhaust Gas Recirculation) system (not shown) of an automobile. The EGR system includes an EGR passage that recirculates part of the exhaust gas from the exhaust passage of the internal combustion engine to the intake passage as EGR gas, and an EGR cooler interposed in the EGR passage. In the internal combustion engine, the EGR gas (heat exchange fluid) cooled by the EGR cooler is recirculated to the intake passage.

  FIG. 1 is a perspective view showing a state in which the core 1 is disassembled. The core 1 includes a cylindrical shell 4 and a plurality of (three) heat exchange tubes 10 (hereinafter simply referred to as “tubes 10”) that are stacked and accommodated inside the shell 4. In the EGR cooler, a pair of cores 1 are provided side by side.

  The shell 4 is formed in a cylindrical shape having a substantially square cross section by assembling the semi-cylindrical shell upper 2 and the shell lower 3.

  A cooling passage pipe (not shown) is connected to the outside of the shell 4. A medium flow path 5 is formed inside the shell 4. The medium flow path 5 is formed around each tube 10 so that the coolant (refrigerant) of the internal combustion engine guided through the cooling passage circulates.

  The tube 10 is formed in a flat cylindrical shape, and a heat exchange channel 11 is formed therein. The open ends (not shown) of the tubes 10 are opened side by side inside the open ends of the shell 4 (see FIG. 4). A duct (not shown) of an EGR passage is connected to the open end of the shell 4 via a header (not shown) so that EGR gas is guided to the heat exchange flow path 11 in each tube 10.

  As shown in FIGS. 2 and 3, the tube 10 is formed in a flat cylindrical shape by connecting a pair of plates 20 to each other.

  The tube 10 may have a configuration in which corrugated fins (not shown) are interposed between the plates 20.

  The plate 20 is formed into a semi-cylindrical shape by pressing a metal plate. The plate 20 includes a lateral wall portion 29 extending in the lateral direction, a first joining wall portion 21 extending longitudinally from the corner portion 27 formed at one end of the lateral wall portion 29, and a corner portion formed at the other end of the lateral wall portion 29. And a second joint wall portion 22 extending in the longitudinal direction from the main body 28. The first joint wall portion 21 and the second joint wall portion 22 extend substantially parallel to each other.

  The cross section of the first joining wall portion 21 extends from the lateral wall portion 29 in a straight line substantially orthogonally. The plate 20 is formed so that the sandwiching angle between the cross section of the first joining wall portion 21 and the cross section of the lateral wall portion 29 is slightly larger than 90 degrees. The corner 27 is shaped to bend with an angle slightly greater than 90 degrees. Accordingly, when the plate 20 is press-fitted into the shell 2, the sandwich angle between the cross section of the first joint wall portion 21 and the cross section of the lateral wall portion 29 becomes approximately 90 degrees, and the first joint is made by the elastic restoring force of the plate 20 The wall portion 21 is pressed against the inner wall surface 4 </ b> A of the shell 2. In other words, the first joint wall 21 is pressed from the inner wall surface 4A of the shell 2 as shown by the arrow D in FIG.

  The cross section of the second joining wall portion 22 has a stepped shape bent in a crank shape. The second joining wall portion 22 is bent from the lateral wall portion 29 and extends in the longitudinal direction, and the stepped portion 24 is bent from the proximal end portion 23 and extends in the lateral direction toward the first joining wall portion 21; And a distal end portion 25 that is bent from the stepped portion 24 and extends in the vertical direction.

  The cross section of the base end portion 23 extends in a straight line from the lateral wall portion 29 substantially orthogonally. The plate 20 is formed such that the sandwich angle between the cross section of the base end portion 23 and the cross section of the lateral wall portion 29 is slightly larger than 90 degrees. The corner 28 is shaped to bend with an angle slightly greater than 90 degrees. Thereby, when the plate 20 is press-fitted into the shell 2, the sandwiching angle between the cross section of the base end portion 23 and the cross section of the lateral wall portion 29 becomes approximately 90 degrees, and the base end portion 23 is moved by the elastic restoring force of the plate 20. Pressed against.

  The distal end portion 25 is spaced laterally with respect to the proximal end portion 23 and extends parallel to the proximal end portion 23. The plate 20 is formed such that the sandwiching angle between the cross section of the distal end portion 25 and the cross section of the lateral wall portion 29 is slightly larger than 90 degrees. As a result, when the plate 20 is press-fitted into the shell 2, the sandwiching angle between the cross-section of the tip portion 25 and the cross-section of the lateral wall portion 29 becomes approximately 90 degrees, and the tip portion 25 is shown in FIG. Is pressed against the first joining wall portion 21 of the mating plate 20 as indicated by an arrow C in FIG.

  The stepped portion 24 extends between the base end portion 23 and the distal end portion 25 and forms a step in the middle of the second joint wall portion 22.

  When manufacturing the EGR cooler, an assembly process for assembling the members 2, 4, 20, etc. constituting the shell 4 and the tube 10 and a brazing process for joining the members 2, 4, 20, etc. by brazing are sequentially performed. Is called.

  First, in the assembling process, before assembling the members 2, 4, 20 and the like, the brazing material is applied to the joining portion.

  In the assembly process, the pair of plates 20 are assembled so as to face each other, and the tube 10 is assembled. When assembling the pair of plates 20 to each other, the other plate 20 is moved vertically with respect to one plate 20 as shown by arrow A in FIG. 2, and horizontally as shown by arrow B in FIG. Move in the direction. Thereby, as shown in FIG. 3, each 1st joining wall part 21 is engaged and assembled | attached so that each front-end | tip part 25 and the stepped part 24 may be contact | abutted. The EGR cooler is joined with a pair of cores 1 arranged side by side.

  In the subsequent brazing process, as shown in FIG. 4, the core 1 is transferred to a heating furnace (not shown) in a state where the tubes 10 are assembled inside the shell 4 and subjected to heat treatment, whereby each joint is brazed. Combined by attaching.

  At the time of brazing, the tube 10 assembled inside the shell 4 is press-fitted so as to be sandwiched between the inner wall surfaces 4A of the shell 4 extending parallel to both ends. Thus, the tube 10 elastically deformed inside the shell 4 generates an elastic restoring force that the first joint wall portion 21 and the second joint wall portion 22 of the plate 20 are to expand. As a result of the elastic restoring force generated in each plate 20 in this way, the first joint wall 21 is pressed against the shell upper 2 as shown by the arrow C in FIG. 5, and the first joint wall 21 is shown by the arrow D in FIG. It is pressed against the tip 25 of the second joint wall 22. Thus, the first joint wall portion 21 and the second joint wall portion 22 are brazed in a state of being pressed against each other, and are joined without generating a gap therebetween.

  The EGR cooler manufactured in this way is assembled to a vehicle to constitute an EGR system.

  During operation of the EGR system, the EGR gas flows through the heat exchange flow path 11 in each tube 10, while the coolant circulates through the medium flow path 5 in the shell 4. The heat of the EGR gas is transmitted to the coolant via each tube 10, and the EGR gas is cooled.

  Next, the effect of this embodiment will be described.

  According to the present embodiment, the tube 10 includes a pair of semi-cylindrical plates 20 that are joined together. The plate 20 has a first joint wall portion 21 and a second joint wall portion 22 that extend in parallel to both ends. The 2nd junction wall part 22 has the step part 24 bent in the middle. The first joining wall portion 21 of one plate 20 is engaged with the stepped portion 24 of the other plate 20 and joined to the second joining wall portion 22.

  Based on the above configuration, the first joining wall portion 21 of one plate 20 and the stepped portion 24 formed on the second joining wall portion 22 of the other plate 20 are engaged, and the first joining wall portion 21 and the second joining wall portion 22 are engaged with each other. The two joint walls 22 are assembled without causing a gap. As a result, the tube 10 is well joined by brazing the two, and leakage of EGR gas flowing through the heat exchange channel 11 is prevented.

  When the tube 10 is assembled, each plate 20 can be moved and assembled in the lateral direction (the direction of arrow B in FIG. 2). Thereby, the assembly | attachment operation | work of each plate 20 can be performed rapidly, and the productivity of the tube 10 can be improved.

  On the other hand, in the conventional heat transfer tube 100 shown in FIG. 6, it is necessary to fit the lower case 120 into the upper case 110 and assemble it. Absent.

  Moreover, in this embodiment, since the pair of plates 20 to be joined to each other have the same shape, each plate 20 can be formed using a common mold. Thereby, the tube 10 can reduce the cost which shape | molds each plate 20. FIG.

  In addition, the tube 10 is press-fitted into the box-shaped shell 4 and joined so that the first joining wall portion 21 of one plate 20 and the second joining wall portion 22 of the other plate 20 are pressed against each other. It was.

  Based on the above configuration, the first joining wall portion 21 and the second joining wall portion 22 are joined in a state of being pressed against each other, and a gap is prevented from being generated between them. Thereby, the tube 10 is prevented from leaking EGR gas flowing through the heat exchange flow path 11.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  The present invention is suitable as a heat exchange tube for an EGR cooler mounted on a vehicle, but a heat exchanger such as a radiator, an oil cooler, an intercooler, or a condenser mounted on the vehicle, or a heat exchanger used other than the vehicle. It can also be applied to.

4 Shell 10 Heat exchange tube 11 Heat exchange flow path 20 Plate
21 1st joining wall part 22 2nd joining wall part 24 Stepped part

Claims (3)

A heat exchange tube through which a fluid for heat exchange flows,
A pair of semi-cylindrical plates joined together;
Each of the plates has a first joining wall portion and a second joining wall portion extending in parallel to both ends,
The second joining wall portion has a stepped portion bent in the middle thereof,
The heat exchange tube, wherein the first joining wall portion of the one plate is engaged with the stepped portion of the other plate and joined to the second joining wall portion. The heat exchange tube according to claim 1,
A pair of the plates to be joined together have the same shape as each other. The heat exchange tube according to claim 1 or 2,
The heat exchange is characterized by being press-fitted into the box-shaped shell and joined so that the first joining wall portion of the one plate and the second joining wall portion of the other plate are pressed against each other. tube.

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