JP2006112651A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger capable of preventing the breakage of a tube caused by a flying pebble or the like during traveling. <P>SOLUTION: In this heat exchanger 100 comprising a heat exchanger core 101 formed by alternately arranging flat tubes 1 having passages 3 for circulating heat exchange mediums inside and cooling fins 14, and header pipes 102, 103 respectively communicated with both ends of the flat tubes 1, the flat tubes 1 are formed by folding and joining a sheet material having a bent portion 5 in the width direction into two at the bent portion 5, and the flat tubes 1 are incorporated in such a state that the bent portions 5 of the flat tubes 1 are directed to an upstream side with respect to the air flowing direction C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat exchanger such as a condenser and an evaporator of an air conditioner, and more particularly to a heat exchanger that prevents a tube from being damaged by a stepping stone when mounted on a vehicle.

  2. Description of the Related Art Conventionally, a laminated heat exchanger is known in which two core plates that form a heat exchange medium passage are joined to form a flat tube, which is superposed together with a heat radiation fin. Since such a heat exchanger is arranged on the front side of the traveling direction of the vehicle, the flat tube is likely to be damaged by a stepping stone during traveling, and when it is damaged, the heat exchange performance deteriorates due to the leakage of the heat exchange medium. It is possible that the device will not function properly.

Therefore, as a conventional technique for preventing the flat tube from being damaged, Patent Document 1 describes heat exchange in which a plate material is formed into a U-shaped cross-section, its joint is directed to the leeward side, and the folded part is directed to the leeward side. A vessel is disclosed. Further, Patent Document 2 discloses a heat exchanger in which a front surface portion that becomes the windward side of the tube is thick.
Japanese Patent Laid-Open No. 10-19485 (FIG. 1) Japanese Utility Model Laid-Open No. 4-138666 (FIG. 4)

  However, the heat exchanger disclosed in Japanese Patent Application Laid-Open No. 10-19485 has a thin folded portion, so there is a concern about insufficient strength against impacts such as stepping stones. It is possible to become. Further, in the heat exchanger disclosed in Japanese Utility Model Publication No. 4-138666, the tube is formed by an extruded material or the like, and therefore, the material and processing cost are higher than those obtained by processing a plate material. It was.

  An object of the present invention is to provide a heat exchanger that can prevent a tube from being damaged by a stepping stone during traveling.

  A heat exchanger according to the present invention includes a heat exchanger core in which a flat tube in which a passage through which a heat exchange medium flows and a fin for cooling are alternately arranged, and both ends of each flat tube, respectively. In the heat exchanger having a header pipe that communicates with each other, the flat tube is joined by folding a plate material provided with a bent portion in the width direction into two folded portions at the bent portion, and the bent portion with respect to the air flow direction. It is assembled so that it may face the upstream side.

  As a preferred embodiment, the flat tube is provided with a bent portion in the width direction of the plate material, and a plurality of protrusions and grooves are alternately formed in parallel with the bent portion on the inner surface side of the plate material, and the plate material is bent. Then, it is folded in half, and the projections facing each other are brought into close contact with each other to be brazed and joined.

  According to the heat exchanger according to the present invention, even when a stepping stone hits the flat tube from the front side of the traveling direction of the vehicle during traveling, the thick bent portion of the flat tube is not damaged because of its high strength. For this reason, it is possible to prevent the flat tube from being damaged by a stepping stone during traveling.

  Hereinafter, the structure of the heat exchanger according to the present invention will be described in Example 1, and the manufacturing method of the flat tube used in Example 1 will be described in Example 2.

  1 to 3 show a first embodiment of the present invention, FIG. 2 is a front view of a heat exchanger, FIG. 3 is an enlarged view of a region A in FIG. 2, and FIG. 1 is a BB line in FIG. It is an expanded sectional view in alignment with.

  As shown in FIG. 2, the heat exchanger 100 includes a heat exchanger core 101 and header tanks 102 and 103. As shown in FIG. 3, the heat exchanger core 101 includes a plurality of flat tubes 1 through which a heat exchange medium flows and corrugated fins 14 arranged between adjacent flat tubes 1 alternately. Configured. A plurality of flat tubes 1 are arranged in parallel along the longitudinal direction of the header tanks 102 and 103. And each flat tube 1 is assembled | attached so that the bending part 5 mentioned later may face an upstream with respect to the air flow direction C, as shown in FIG. In FIG. 1, the upstream side (the right side in the figure) with respect to the air flow direction C corresponds to the front side in the traveling direction of the vehicle.

  According to the heat exchanger 100 of the present embodiment, even when a stepping stone hits the flat tube 1 from the front side in the traveling direction of the vehicle during traveling, the bent portion 5 that is a thick wall of the flat tube 1 is damaged due to its high strength. Therefore, the flat tube 1 can be prevented from being damaged by a stepping stone during traveling.

  In particular, in the flat tube 1 shown in the present embodiment, the thickness from the tube end to the outermost passage is thick, and the bent portion 5 has a high strength due to work hardening by rolling during bending forming. Compared with a folded portion having a U-shaped cross section such as the above, or a joined portion where end portions are joined together, a sufficient strength can be given to impacts such as stepping stones. Therefore, the possibility of tube breakage can be reduced even during long-term use. Moreover, since the flat tube 1 shown in a present Example can be manufactured with a cheap board compared with what was shape | molded by the extrusion material etc. like patent document 2, it can reduce material and a processing cost.

  4 to 10 show a second embodiment of the present invention. FIG. 4 is a cross-sectional view of a flat tube obtained by the manufacturing method of the present embodiment. FIG. 5 is a view of a plate material in which protrusions and grooves are processed on the inner surface side. 6 is an enlarged view of the D range portion of FIG. 5, FIG. 7 is a sectional view showing a V-shaped bending state of the plate material, FIG. 8 is an enlarged view of the E range portion of FIG. 4, and FIG. FIG. 10 is an enlarged view of the F range portion of FIG. 9.

  In the heat exchanger to which the flat tube 1 of the second embodiment is applied, as shown in the first embodiment, a plurality of flat tubes arranged in parallel are connected in communication between a pair of opposed header tanks, and a heat exchange medium is used. The heat exchange medium introduced into one header tank is fed to the other header tank via the flat tube, and the flattened tube is configured so that the fins for heat dissipation are interposed between the flat tubes. In the process of circulating the tubes, heat exchange is performed between the heat exchange medium and the air flowing between the flat tubes.

  The heat exchanger 100 according to the first embodiment is used in a refrigeration cycle or a heat pump cycle in which carbon dioxide is used as a heat exchange medium. Since the internal pressure of the heat exchanger is significantly increased, as shown in FIG. In addition, the flat tube 1 has a structure in which a plurality of passages 3 partitioned by a partition wall 2 are arranged in parallel in order to ensure pressure resistance.

  As shown in FIGS. 5 and 6, the flat tube 1 is provided with a bent portion 5 at the center in the width direction of a plate material 4 made of an aluminum material. A plurality of protrusions 6 and grooves 7 are alternately formed symmetrically with respect to the bent portion 5, and the plate material 4 is folded in two at the bent portion 5 so that the opposing protrusions 6 and 6 are brought into close contact with each other. It is completed by attaching.

  That is, the partition 2 is constituted by the opposed protrusions 6 and 6, and the passage 3 is constituted by the opposed grooves 7 and 7.

  As described above, a clad material having an aluminum material as a base material and a brazing material layer provided on the outer surface is used as the plate material 4 as described above, and this is processed into a plurality of protrusions 6 and grooves by rolling or pressing. 7 is formed.

  Here, the bent portion 5 is formed with a convex portion 5 a having the same height as the protrusion 6 on the inner surface side, and a concave portion 5 b provided in the central portion on the outer surface side of the bent portion 5. The thickness t1 is smaller than the thickness t2 of the portion of the plate 4 where the groove 7 is formed (t1 <t2).

  The plate 4 obtained in this way is folded in half as follows.

  FIGS. 7 and 8 show a roll forming step before the plate material 4 is folded in two. In this roll forming step, the lower roll 10 and the upper roll 11 are used to place the plate material 4 on the basis of the center of the bent portion 5. It is designed to be bent into a letter shape.

  In this roll forming process, the plate 4 is passed through a plurality of pairs of upper and lower pairs of rolls 10 and 11, and the V-shaped bending angle is gradually narrowed. The V groove of the lower roll 11 used in this roll forming process The top portion 11a is formed flat, while the V-projection top portion 10a of the upper roll 10 has a simple V shape.

  In addition to these, the lower rolls 10 and 11 are used to bend the plate material 4 into a V shape with the center of the bent portion 5 as a base point. In order to perform the V shape bending of the plate material 4 with higher accuracy, for example, as shown in FIG. Thus, it is preferable to provide the notch 8 at the center of the concave portion 5b on the outer surface side of the bent portion 5.

  Then, after bending the plate material 4 into a V-shape with a required clamping angle in the roll forming process, the plate material 4 is completely folded in two by the left and right rolls 12 and 13 in the wrist-like process as shown in FIGS. The flattened tube 1 shown in FIG. 4 is configured by bringing the projections 6 and 6 and the convex portions 5a and 5a facing each other into close contact with each other.

  The flat tube 1 is finally heated in a heating furnace (not shown) in the heating process to braze the opposed protrusions 6 and 6 and the protrusions 5a and 5a together. In this heating process, the flat tube 1 is flattened. A plurality of tubes 1 are connected in communication with a pair of header tanks (not shown), and a heat exchanger is formed by interposing a radiating fin between the flat tubes 1, 1. The header tank is heated by a heating furnace. The flat tube 1 and the radiation fins are brazed and joined at once, and the above-described protrusions 6 and 6 and the projections 5a and 5a are brazed and joined simultaneously in the heating step.

  As described above, according to the present embodiment, when the plate material 4 is bent into a V shape by roll forming in the process of folding the plate material 4 in two and overlapping, the bending portion 5 of the plate material 4 Since the convex portion 5 a having the same height as the protrusion 6 is provided on the inner surface side, the cross-sectional shape of one roll 10 that processes the inner surface side of the plate material 4 can be a simple V-shape. Since the concave portion 5b is formed in the central portion of the outer surface 5 and the thickness of the central portion of the bent portion 5 is thinned, the V-shaped bending of the plate material 4 can be accurately performed without complicating the roll shape. Can be done well.

  Then, when the plate material 4 is folded into two in the wrist-like process after the V-shaped bending process, the convex portion 5a of the bent portion 5 is folded in two from the center to become a solid state. In addition, the bending points are not deformed and displaced, and the protrusions 6 can be formed in close contact with each other accurately, and both the inner shape and the outer shape of the flat tube 1 can be formed with high accuracy. .

The expanded sectional view along the BB line of FIG. The front view of the heat exchanger in Example 1 of this invention. The enlarged view of the A range part of FIG. Sectional drawing which shows the flat tube obtained by the manufacturing method of Example 2 of this invention. Sectional drawing of the board | plate material in Example 1 of this invention. The enlarged view of the D range part of FIG. Sectional drawing which shows the V-shaped bending state of the board | plate material in Example 2 of this invention. The enlarged view of the E range part of FIG. Sectional drawing which shows the processing state superimposed on the folding of the board | plate material in Example 2 of this invention. The enlarged view of the F range part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Flat tube 2 Partition 3 Passage 4 Board | plate material 5 Bending part 5a Convex part 5b Concave part 5c Bending guide protrusion 5d Notch groove 6 Protrusion 7 Groove 8 Notch 10 Upper roll 11 Lower roll 12 Left roll 13 Right roll 14 Fin 100 Heat exchanger 101 Heat Exchanger core 102, 103 Header tank

Claims (1)

A flat tube (1) in which a passage (3) through which a heat exchange medium flows is formed, and a heat exchanger core (101) in which cooling fins (14) are alternately arranged, and the flat tubes (1) ), And a heat exchanger provided with header pipes (102, 103) respectively communicating with both ends of the
The flat tube (1) is joined by folding a plate material (4) provided with a bent portion (5) in the width direction into two at the bent portion (5), and the bent portion (5) is in the direction of air flow. The heat exchanger is assembled so as to face the upstream side.

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