JP4166137B2 - Heat exchange tube in heat exchanger - Google Patents

Description

  The present invention provides, for example, an inner fin provided in an interior of a heat exchanger in which a fluid such as exhaust gas or lubricating oil that recirculates to an intake system in an internal combustion engine is cooled by ventilation of atmospheric air. The present invention relates to a heat exchange tube made of a metal plate.

  Patent document 1 as a prior art discloses the technique described below about this kind of heat exchange tube.

That is, in the state where two tube pieces having a U-shaped cross-section facing each other are inserted with inner fins between them, the left and right bent portions in one tube piece are both left and right in the other tube piece. It fits together so that it may cover the outer side of a bending part, and it is set as the structure which joins the joining part in the right and left both sides by brazing.
JP-A-6-257974

  However, since the heat exchange tube of the prior art has a structure that is not coupled to each other when the two tube pieces are fitted together, when joining the two tube pieces by brazing, By pressing the tube pieces so as to sandwich each other, the inner fins inserted between the tube pieces are brought into close contact with the tube pieces, and the above-described brazing joining is performed in a state where the pressure is held. If the pressure is loosened even a little, the inner fins are separated from both tube pieces, and the thermal conductivity between them is significantly reduced.

  That is, when brazing and joining the two tube pieces, until the brazing joining is completed, the tube pieces are always strongly pressed so that the close contact with the inner fin is not loosened. Must be. In addition, in the prior art heat exchange tube, when both tube pieces are fitted to each other, there is a gap between the left and right bent portions of one tube piece and the left and right bent portions of the other tube piece. In addition, since there is a variation in the gap, as described above, it is ensured that the tube pieces are always strongly pressed so that the close contact with the inner fin is not loosened. Combined with this, it is not only difficult to braze, but the brazing work becomes very difficult, so there is a high risk of defects in brazing and joining. There was a problem that the cost required increased significantly.

  In some cases, as described above, the heat exchange tube incorporating the inner fin is formed into one tube piece and the other tube piece sandwiching the inner fin by folding a single metal plate into two. The two tube pieces are fitted so that the bent portion of the other tube piece covers the outside of the inward bent portion provided at the tip of one tube piece, and the fitting portion is brazed and joined. In this case as well, in this case, when brazing the mating portion, the tube pieces are always strongly pressed so as not to loosen the inner fin. There was a problem similar to the above.

  This invention makes it a technical subject to provide the heat exchange tube which eliminated these problems.

In order to achieve this technical problem, claim 1 of the present invention provides:
“Two metal plate tube pieces folded in a U-shaped cross section facing each other, with an inner fin interposed therebetween, and the other tube on the outside of the left and right bent portions of one tube piece. In the heat exchange tube formed by fitting so that the left and right bent parts of the piece are covered, and brazing the mating parts on the left and right sides,
An inclined surface that is inclined outwardly toward the other tube piece is provided outside the both bent portions of the one tube piece, while the two bent portions of the other tube piece have their tips at the one tube piece. Were bent inward so as to elastically contact the inclined surfaces of the two bent portions. "
It is characterized by that.

Further, claim 2 of the present invention provides
“A single metal plate is folded in half to form one tube piece sandwiching the inner fin and the other tube piece, and the inward facing provided at the tip of one of these tube pieces. In the heat exchange tube formed by fitting outside the bent part so that the inwardly bent part of the other tube piece covers, and joining the mated part by brazing,
An inclined surface that is inclined outwardly toward the other tube piece is provided outside the bent portion of the one tube piece, while the bent portion of the other tube piece is bent at the tip of the one tube piece. Bent inward to elastically contact the inclined surface of the part. "
It is characterized by that.

Furthermore, claim 3 of the present invention provides
“In the description of claim 1 or 2, either one or both of the plate portion of the one tube piece and the plate portion of the other tube piece are curved inwardly.”
It is characterized by that.

  According to the first and second aspects of the present invention, in the other tube piece, the tip of the bent portion bent inward is elastically contacted with the outward inclined surface provided in the bent portion of the one tube piece. By doing so, the tube pieces fit together so that they are not separated from each other, and the elastic force of the tube pieces acts on the inclined surface, so that the tube pieces attract each other. Therefore, at the time of brazing and joining, when pressing both tube pieces so as to sandwich each other as in the prior art, the inner fins are not attached to both tube pieces even if the pressing may be slightly loosened. It is possible to reliably maintain a close state. In addition to this, the tip of the bent portion bent inward in the other tube piece is in elastic contact with the outward inclined surface provided in the bent portion in one tube piece, thereby It is possible to reliably eliminate a gap in the part to be attached.

  That is, according to the present invention, brazing between both tube pieces can be performed in a state in which both tube pieces are not firmly sandwiched with a large force and there is no gap, which is necessary for the brazing operation. The number of operations can be greatly reduced, and the workability of brazing can be greatly improved, so that reduction of costs and occurrence of defective brazing can be reliably achieved.

  Moreover, according to the structure described in Claim 3, when the plate part in both said tube pieces joins together and joins both tube pieces, it is flat from the state which the plate part in the one or both curved inwardly convex, or Since it will be pressed with respect to an inner fin with the elastic force at the time of elastically deforming so that it may approach flat, the close_contact | adherence with respect to the inner fin of both tube pieces can be improved reliably.

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

  1 to 3 show a heat exchanger 1 using a heat exchange tube according to the present invention, and this heat exchanger 1 has a plurality of heat exchanges between an inlet header 2 and an outlet header 3. Tubes 4 are provided, and each of the heat exchange tubes 4 flows through the inlet header 2 toward the outlet header 3 (for example, in an internal combustion engine, exhaust gas or lubricating oil that recirculates to the intake system), The outside of each heat exchange tube 4 is configured to exchange heat with a fluid such as atmospheric air flowing across the tube.

  Each of the heat exchange tubes 4 is formed in a flat shape such as an oval in cross section with a metal plate such as aluminum, and the heat exchange tube 4 is formed by bending the metal plate into a corrugated cross section. Inner fin 5 is inserted.

  And in 1st Embodiment shown in FIGS. 4-7, each heat exchange tube 4 consists of two metal-plate tube pieces 6 and 7, and the said inner fin 5 inserted between them, both said One of the tube pieces 6 and 7 (upper side in the figure) is formed in a U-shaped cross-section so as to have downward bent portions 6b and 6c on both left and right sides of the plate portion 6a. The tube piece 7 (lower side in the figure) is formed in an upward U-shaped cross section so as to have upward bent portions 7b, 7c on the left and right sides of the plate portion 7a.

  The inner fin 5 is interposed between the tube pieces 6 and 7 so that the left and right bent portions 7b and 7c of the other tube piece 7 are covered outside the left and right bent portions 6b and 6c of the one tube piece 6. The inner fins 5 are fitted to each other, and the inner fins 5 are in close contact with the plate portions 6a and 7a of the tube pieces 6 and 7, and the mating portions on the left and right sides thereof are brazed and joined.

  In this case, by bending the left and right bent portions 6b, 6c of one of the tube pieces 6, 7 (upper side in the figure) inward, the other tube piece 7 is formed on the outer surface thereof. The left and right bent portions 7b and 7c of the tube piece 7 on the other side (lower side in the figure) of the tube pieces 6 and 7 are bent inward while the inclined surfaces 6d and 6e are provided to be inclined outward. As a result, the tips 7d and 7e are configured to elastically contact the inclined surfaces 6d and 6e of the left and right bent portions 6b and 6c of the one tube piece 6, and the tips 7d and 7e. Is configured to be joined to the inclined surfaces 6d and 6e by brazing. In addition, a brazing part is shown with the code | symbol 8. FIG.

  Thus, in the other tube piece 7 of the tube pieces 6 and 7, the left and right bent portions 7b and 7c bent inward are connected to one tube of the tube pieces 6 and 7, respectively. The tube pieces 6 and 7 are fitted so as not to be separated from each other by elastically contacting the outward inclined surfaces 6d and 6e provided at the left and right bent portions 6b and 6c of the piece 6. It will be a good match.

  In addition to this, the elastic force P acts on the inclined surfaces 6d, 6e of the one tube piece 6 as shown in FIG. When the two pieces are pressed together so as to sandwich each other as in the above prior art, the pressure may be slightly loosened. The state in which the inner fin 5 is in intimate contact with both the tube pieces 6 and 7 can be maintained.

  Further, the distal ends 7d and 7e of the left and right bent portions 7b and 7c bent inward in the other tube piece 7 are outwardly inclined surfaces 6d and 6b provided in the left and right bent portions 6b and 6c of the one tube piece 6, respectively. The elastic contact with 6e can surely eliminate the formation of a gap in the brazed portion.

  In addition, as shown by a two-dot chain line in FIGS. 5 and 6, one or both of the plate portion 6 a in the one tube piece 6 and the plate portion 7 a in the other tube piece 7 It is curved in the direction of convexity, and when the tube pieces 6 and 7 are joined, the inwardly convex curve is elastically deformed so as to resist the elasticity or approach the flat.

  With this configuration, the plate portions 6a and 7a of the tube pieces 6 and 7 are pressed against the inner fin 5 by the elastic force, so that the closeness of the tube pieces 6 and 7 to the inner fin 5 is ensured. It can be improved.

  Next, FIGS. 8 and 9 show a second embodiment.

  In the second embodiment, a single metal plate is folded in half to form one tube piece 6 ′ and the other tube piece 7 ′ sandwiching the inner fin 5.

  An inwardly bent portion 6b 'of the other tube piece 7' is provided outside the inwardly bent portion 6b 'provided at the tip of one of the tube pieces 6' and 7 '. The heat exchange tube 4 'is formed by fitting so as to cover them and brazing and joining the joints.

  In addition, a brazing part is shown with the code | symbol 8 '. The tube pieces 6 'and 7' are arranged on the outside of the inwardly bent portion 6b 'provided at the tip of the one tube piece 6' and on the inwardly bent portion 6b 'of the other tube piece 7'. When fitted so as to cover, the plate portions 6a 'and 7a' of the tube pieces 6 'and 7' are configured to be elastically in close contact with the inner fin 5 therebetween.

  Also in this case, as in the first embodiment, on the outer surface of the bent portion 6b 'of one of the tube pieces 6' and 7 ', the other tube piece 7' is provided. An inclined surface 6d 'that is inclined outward is provided, while the tip 7d' of the bent portion 7b 'of the other tube piece 7' of the two tube pieces 6 ', 7' is in the one tube piece 6 '. The bent portion 6b 'is configured to elastically contact the inclined surface 6d', and the tip 7d 'is joined to the inclined surface 6d' by brazing.

  With this configuration, when the two tube pieces are pressed so as to sandwich each other, the inner fins 5 are reliably attached to both the tube pieces 6 ′ and 7 ′ even if the press is slightly loosened. It is possible to maintain a close contact state and reliably eliminate a gap in the brazed portion.

  In the second embodiment, either one or both of the plate portion 6a 'in the one tube piece 6' and the plate portion 7a 'in the other tube piece 7' are shown in FIG. As shown by a two-dot chain line, the inwardly convex curve is curved in advance, and when the tube pieces 6 'and 7' are joined, the inwardly convex curve is flattened against its elasticity. It is possible to improve the closeness of the tube pieces 6 and 7 to the inner fin 5 by elastic deformation so as to approach the flat.

It is a perspective view which shows a heat exchanger. It is a front view of FIG. FIG. 3 is an enlarged sectional view taken along line III-III in FIG. 1. It is an expanded sectional view of the heat exchange tube by 1st Embodiment used for the said heat exchanger. It is a disassembled perspective view of the heat exchange tube by the said 1st Embodiment. FIG. 6 is a sectional view taken along line VI-VI in FIG. 5. It is a figure which shows the principal part of the heat exchange tube by the said 1st Embodiment. It is an exploded view of the heat exchange tube by 2nd Embodiment. It is sectional drawing of the heat exchange tube by 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2, 3 Header 4, 4 'Heat exchange tube 5 Inner fin 6, 6' One tube piece 6a, 6a 'Plate part 6b, 6c, 6b', 6c 'Bending part 6d, 6e, 6d' Inclined surface 7, 7 'The other tube piece 7a, 7a' Plate part 7b, 7c, 7b ', 7c' Bending part 7d, 7e, 7d 'End of bending part 8, 8' Brazing part

Claims (3)

Two metal plate tube pieces bent in a U-shaped cross section facing each other are inserted with an inner fin between them, and the other tube piece is placed outside the left and right bent portions of one of the tube pieces. In the heat exchange tube formed by fitting so as to cover the left and right bent parts in and brazing the mating parts on the left and right sides,
An inclined surface that is inclined outwardly toward the other tube piece is provided outside the both bent portions of the one tube piece, while the two bent portions of the other tube piece have their tips at the one tube piece. A heat exchange tube in a heat exchanger, wherein the heat exchange tube is bent inwardly so as to elastically contact the inclined surfaces of the two bent portions. A single metal plate is folded in half to form one tube piece sandwiching the inner fin and the other tube piece, and an inward bend provided at the tip of one of these tube pieces. In the heat exchange tube formed by fitting the outer part of the other tube piece so that the inwardly bent portion of the other tube piece covers, and brazing and joining the mating part,
An inclined surface that is inclined outwardly toward the other tube piece is provided outside the bent portion of the one tube piece, while the bent portion of the other tube piece is bent at the tip of the one tube piece. A heat exchange tube in a heat exchanger, wherein the heat exchange tube is bent inward so as to elastically contact the inclined surface of the part.   The heat exchange according to claim 1 or 2, wherein one or both of the plate portion of the one tube piece and the plate portion of the other tube piece are curved inwardly. Heat exchange tube in the oven.

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