JP6326753B2 - Heat exchanger - Google Patents

Description

  The present invention relates to a heat exchanger, and more particularly to a cross fin tube heat exchanger used in an air conditioner or the like.

  A conventional cross fin tube type heat exchanger has a plurality of hairpin tubes penetrating through holes formed in a surface portion of a laminated fin in which plate-like fins are stacked at a predetermined interval, and U for connecting hairpin tubes to each other. The connection part of the said hairpin pipe | tube and the said U-shaped pipe is welded with the brazing material.

  As shown in FIG. 10, the connecting portion between the hairpin tube and the U-shaped tube forms a large-diameter portion 121 by expanding the tube end portion of the hairpin tube 120 penetrating the laminated fin 110 and having the opening portion facing upward. Further, the end portion of the hairpin tube is expanded to form the expanded portion 122. A U-shaped tube 140 having an outer diameter slightly smaller than the inner diameter of the large diameter portion 121 is inserted into the large diameter portion 121. At this time, the brazing material 150 is disposed in the expanded portion 122 of the hairpin tube, and the inner peripheral surface of the large diameter portion 121 and the outer peripheral surface of the U-shaped tube 140 are joined by the brazing material 150 by being put in a furnace (for example, publicly known) For example, see Patent Document 1).

  However, when the hairpin tube 120 and the U-shaped tube 130 are joined together in this way, the amount of use of the brazing material 150 by the welding operator and the subtle operation adjustment such as the heating temperature are affected, as shown in FIG. The material 150 may protrude from the inner surface side of the hairpin tube 120 through the gap between the joint surfaces.

  The brazing material 150 that has entered the hairpin tube 120 becomes a flow path resistance in the tube, resulting in increased pressure loss and reduced heat exchange efficiency. In the worst case, the brazing material 150 may clog the inside of the hairpin tube 120.

  In order to solve such a problem, as shown in FIG. 11, the inner peripheral surface of the end portion 41 of the U-shaped tube 40 is connected so as to fit the outer peripheral surface of the end portion 21 of the hairpin tube 20, and the hairpin tube 20 By joining the outer peripheral surface of the U-shaped tube 40 and the outer peripheral surface of the hairpin tube 20 by the auxiliary member 30 that continuously covers the outer peripheral surface of the U-shaped tube 40 and the outer peripheral surface of the U-shaped tube 40, the brazing material is a hairpin. A method of preventing the flow into the tube 20 and preventing a decrease in heat exchange efficiency due to an increase in pressure loss and clogging of the brazing material in the flow channel in the hairpin tube 20 can be considered.

  When it was set as the above structures, the number of parts increased compared with the past, and there existed a problem that a manufacturing cost also increased and the product cost increased.

JP 2002-263879 A

  The present invention was made to solve such a problem, and in the case where the hairpin tube and the U-shaped tube are connected via separate members, the heat exchanger and the heat exchange in which the number of parts and the number of manufacturing steps are reduced. It aims at providing the manufacturing method of a vessel.

The heat exchanger of the present invention includes a plurality of stacked fins, a pair of tube plates provided at both ends of the fins in the stacking direction, and a plurality of through holes provided in the fins and the tube plate. In the cross-fin type heat exchanger having a hairpin tube and a connection tube connecting different hairpin tubes, the connection tube is connected to the hairpin tube, and the connection tube end is continuous with the connection tube end. The connecting pipe end is fitted so that the inner peripheral surface thereof overlaps with the outer peripheral surface of the tube end of the hairpin pipe, and one of the pipes on the side facing the connecting pipe The plate has a plate portion and a connection auxiliary portion that continuously covers the outer peripheral surface of the hairpin tube and the outer peripheral surface of the connection tube, and the connection auxiliary portion has a smaller diameter portion larger than the outer diameter of the hairpin tube, A larger diameter portion than the outer diameter of the connecting pipe, the smaller diameter portion and the larger diameter portion And a diameter gradually increased tapered connecting portion to the large diameter portion from said small diameter portion side connecting the large-diameter portion is connected to the plate portion via the small-diameter portion And formed between the outer peripheral surface of the hairpin tube and the inner peripheral surface of the small diameter portion, and between the outer peripheral surface of the connection tube and the inner peripheral surface of the large diameter portion. It has the 2nd junction part.

  Further, the connection auxiliary portion connects the small diameter portion larger than the outer diameter of the hairpin tube, the large diameter portion larger than the outer diameter of the connection tube, and the small diameter portion and the large diameter portion from the small diameter portion side. And a tapered connection portion having a diameter that gradually increases toward the large-diameter portion.

In the heat exchanger manufacturing method of the present invention, a plurality of hairpin tubes are arranged at a predetermined interval, and the plurality of laminated fins are inserted into a plurality of through holes provided in the hairpin tubes. A step of assembling so as to be inserted; a small diameter portion where the inner peripheral surface overlaps with the outer peripheral surface of the hairpin tube when the hairpin tube is penetrated; and a large diameter portion that is coaxial and has a larger inner diameter than the small diameter portion a step for inserting arranged a tube plate is laminated on the fins and tube expanding said plurality of hairpin tubes, and joining the fins and the tube plate and the hairpin tube, and the small-diameter portion and the hairpin tube A step of forming a first joint portion therebetween, and a pipe end portion of a connecting pipe that connects pipe flow paths between different hairpin pipes in a radial gap between the hairpin pipe and the large diameter portion. The step of inserting, and the end of the hairpin tube is And a step of forming a second joint portion between the connecting pipe and the large-diameter portion in a state of facing toward the direction.

  According to the present invention, since the hairpin tube and the U-shaped tube are connected via the connection auxiliary portion provided in the tube plate, the number of parts and the number of manufacturing steps can be reduced.

It is a schematic perspective view which shows the whole heat exchanger of 1st Embodiment of this invention. It is a schematic perspective view which shows the components which comprise the heat exchanger of 1st Embodiment of this invention. It is a schematic sectional drawing which shows the hairpin tube and auxiliary | assistant tube plate after joining with the fin set in the heat exchanger of 1st Embodiment of this invention. It is a schematic sectional drawing which shows the hairpin tube and U-shaped tube after welding the tube plate with an auxiliary | assistant in the heat exchanger of 1st Embodiment of this invention. It is a schematic sectional drawing which shows the hairpin tube and auxiliary | assistant tube sheet after insertion of the U-shaped tube in the heat exchanger of 1st Embodiment of this invention. It is a schematic sectional drawing which shows the connection part of the hairpin pipe | tube and U-shaped pipe after welding in the heat exchanger of this invention. It is a schematic sectional drawing which shows the hairpin tube and auxiliary | assistant tube plate after joining with the fin group in the heat exchanger of 2nd Embodiment of this invention. It is a schematic block diagram which shows the hairpin tube and U-shaped tube after welding the tube plate with an auxiliary | assistant in the heat exchanger of 2nd Embodiment of this invention. It is a schematic perspective view which shows the hairpin tube and auxiliary | assistant tube plate after insertion of the U-shaped tube in the heat exchanger of 2nd Embodiment of this invention. It is sectional drawing which shows the connection part of the hairpin tube and U-shaped tube of the conventional heat exchanger. It is sectional drawing which shows the connection part of the hairpin tube and U-shaped tube of the heat exchanger used as the original proposal of this invention.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The present invention is not limited to the following embodiments, and can be variously modified without departing from the gist of the present invention.

  FIG. 1 shows a heat exchanger 1 according to the present embodiment, which is a fluid such as a refrigerant flowing through an in-tube flow path formed by a hairpin tube 20 and a U-tube 40 described later, and air passing between laminated fins 11. FIG. 2 is a schematic perspective view of a cross fin tube type heat exchanger that performs heat exchange with a fluid such as FIG. 2, and FIG. 2 is an exploded perspective view of the heat exchanger 1.

  As shown in FIG. 2, the heat exchanger 1 of the present embodiment includes a fin set 10 including a laminated fin 11 in which fins 11 a are stacked, a tube plate 12, and an auxiliary tube plate 60, a plurality of hairpin tubes 20, It is composed of a plurality of U-shaped tubes 40 and a ring brazing material 50 described later.

  The fin 11a is a plate-like aluminum fin having a slit or the like formed on the surface thereof, and transfers heat of a fluid such as a refrigerant flowing through the hairpin tube 20. The laminated fins 11 are formed by overlapping a plurality of fins 11a in the vertical direction with a predetermined interval.

  The tube plate 12 is a metal plate that is provided on one side in the stacking direction of the stacked fins 11 and has higher rigidity than the fins 11a. The tube plate 12 is provided with a fixing portion (not shown) for screw fixing when the heat exchanger 1 is attached to a product main body such as an air conditioner.

  The auxiliary tube plate 60 is a metal plate that is provided on the other side in the stacking direction of the stacked fins 11 and has higher rigidity than the fins 11a. Similarly to the tube plate 12, the auxiliary tube plate 60 is provided with a plate portion 62 provided with a fixing portion (not shown) for fixing the heat exchanger 1 to a product main body such as an air conditioner, and a connection described later. It consists of an auxiliary part 61.

  Further, as described above, the fin set 10 is constituted by the laminated fin 11 and the tube plate 12 and the auxiliary tube plate 60 provided on both sides of the laminated fin 11 in the lamination direction.

  The laminated fin 11, the tube plate 12, and the auxiliary tube plate 60 constituting the fin set 10 are provided with a through hole 13 provided to penetrate an end portion 21 of the hairpin tube 20 described later. The diameter of the through hole 13 is slightly larger than the outer diameter of the hairpin tube 20.

  The hairpin tube 20 is a metal tube having a groove shape or the like inside, and is bent into a U shape as shown in the figure. When the heat exchanger 1 is used, a fluid such as a refrigerant flows through the inside, and the hairpin tube 20 transfers the heat of the fluid to the fins 11a. The hairpin tube 20 is expanded through the end 21 through the through holes 13 of the laminated fin 11, the tube plate 12, and the auxiliary tube plate 60, and is brought into pressure contact with the fin set 10. Thereby, the fin set 10 and the hairpin tube 20 are joined.

  The U-shaped tube 40 is a metal tube and includes a bent tube portion 42 formed in a U shape and an end portion 41 that is a tube end. It is a connecting pipe that connects the end portions 21 of adjacent hairpin tubes 20 fixed to the fin set 10 and connects the in-tube flow paths of the hairpin tubes 20. The end 41 of the U-shaped tube 40 is expanded, and the inner diameter is slightly larger than the outer diameter of the hairpin tube 20 after the expansion. In this embodiment, the U-shaped tube end 41 is expanded, but if the inner diameter of the curved tube 42 is slightly larger than the outer diameter of the hairpin tube 20 after expansion, the expanded tube is used. There is no need to do this, and the number of processes can be reduced. Moreover, although it is set as the U-shaped pipe | tube 40 which connects the edge parts 21 of the adjacent hairpin tube 20 fixed to the fin set 10 in a present Example, if the edge parts 21 of different hairpin tubes 20 are connected, it is. It may be a connecting pipe that connects the end portions 21 that are not adjacent to each other. More specifically, it may be a connecting tube that connects the hairpin tube 20a and the hairpin tube 20c or the hairpin tube 20d in FIG.

  Next, the connection auxiliary part 61 of the auxiliary tube sheet 60 will be described with reference to FIG. The connection auxiliary part 61 is formed integrally with the plate part 62, and is formed by successively connecting a small diameter part 611, a connection part 613, a large diameter part 612, and a pipe expansion part 614, and the hairpin tube 20 and the U-shaped tube. 40 is connected.

  The small-diameter portion 611 is a part of the connection assisting portion 61 and has an inner diameter slightly larger than the outer diameter after the hairpin tube 20 is expanded.

  The large-diameter portion 612 is a part of the connection auxiliary portion 61 and has an inner diameter slightly larger than the outer diameter of the U-shaped tube end portion 41.

  The connection part 613 is a part of the connection auxiliary part 61 and is located between the small diameter part 611 and the large diameter part 612 and has a tapered surface whose inner diameter gradually decreases from the large diameter part 32 side to the small diameter part 31 side. have.

  The expanded pipe portion 614 is a part of the connection assisting portion 61, and has an inner diameter that is larger than that of the large diameter portion 612 and is tapered so that the inner diameter increases from the large diameter portion 612 toward the end. The pipe expansion part 614 becomes an installation place of the ring brazing material 50 described later at the time of welding.

  As shown in FIG. 4, the ring brazing material 50 is a brazing material formed in a ring shape, and an alloy having a melting point lower than that of the hairpin tube 20, the U-shaped tube 40, and the connection auxiliary portion 61, which are base materials, is used.

  Next, the connection location of the hairpin tube 20 and the U-shaped tube 40 will be described in detail with reference to FIG.

  As shown in FIG. 6, the end 21 of the hairpin tube 20 penetrating the fin set 10 is inserted into the end 41 of the U-shaped tube 40. Further, there is a slight space between the outer peripheral surface of the hairpin tube 20 and the inner peripheral surface of the small-diameter portion 611 of the connection assisting portion 61, and the ring brazing material 50 installed in the expanded tube portion 614 is dissolved and the space is concerned. And the joint portion 51B is formed. Further, there is a slight space between the outer peripheral surface of the end portion 41 of the U-shaped tube 40 and the inner peripheral surface of the large-diameter portion 612 of the connection assisting portion 61, and the ring brazing material 50 installed in the pipe expanding portion 614. Melt | dissolves and flows into the said space, and forms the junction part 51A. With the above configuration, the fitting portion between the hairpin tube 20 and the U-shaped tube 40 is covered by the connection assisting portion 61, and the connection assisting portion 61 includes the small diameter portion 611 and the hairpin tube 20. Since the diameter portion 612 and the U-shaped tube 40 are each welded with the brazing material, the in-tube flow path of the hairpin tube 20 and the in-tube flow path of the U-shaped tube 40 are connected in a state where airtightness is ensured.

  Next, the manufacturing process of the heat exchanger 1 of this embodiment is demonstrated in detail using FIG. 2 thru | or 6. FIG.

  As shown in FIG. 2, in the cross fin tube heat exchanger of the present invention, first, the hairpin tube 20 has a plurality of through holes 13 provided in the fin assembly 10 so that the end portion 21 faces upward. A plurality are arranged at an interval corresponding to the arrangement interval. The through hole 13 of the fin set 10 is made to penetrate from the upper side to the end portion 21 of the arranged hairpin tube 20. After penetration, each hairpin tube 20 and the fin set 10 are joined by expanding each hairpin tube 20.

  When the hairpin tube 20 and the fin set 10 are joined, as shown in FIG. 3, the connection auxiliary portion 61 is the end portion 21 of the hairpin tube 20 so that the small diameter portion 611 is on the lower side and the large diameter portion 612 is on the upper side. It will be in the state fitted on the outside. At this time, the outer diameter of the hairpin tube 20 is slightly smaller than the inner diameter of the small-diameter portion 611 of the connection auxiliary portion 61. Further, a gap is formed between the large diameter portion 612 of the connection assisting portion 61 and the end portion 21 of the hairpin tube 20 in which the U-shaped tube end portion 41 can be inserted in the radial direction.

  Next, as shown in FIG. 4, the ring brazing material 50 is fitted on the outer side of the U-shaped tube 40, and the U between the large-diameter portion 612 of the connection auxiliary portion 61 and the end portion 21 of the hairpin tube 20 described above. Insert the end 41 of the tube 40. At this time, the inner diameter of the end 41 of the U-shaped tube 40 is slightly larger than the outer diameter of the hairpin tube 20, and the outer diameter of the U-shaped tube 40 is slightly smaller than the inner diameter of the large-diameter portion 612 of the connection assisting portion 61. After the insertion, when the ring brazing material 50 that has been fitted to the outside of the U-shaped tube 40 in advance is installed in the expanded tube portion 614 of the connection assisting portion 61, the state shown in FIG.

  5, the ring brazing material 50 is melted and flows between the U-shaped tube end portion 41 and the large diameter portion 612 by its own weight as shown in FIG. 6. Further, the ring brazing material 50 also flows between the hairpin tube 20 and the small diameter portion 611. As a result, the U-shaped tube end portion 41 and the large-diameter portion 612, and the hairpin tube 20 and the small-diameter portion 611 are welded to form joint portions 54 and 53, respectively, and the joint portions 54 and 53 are sealed with brazing material. . In this embodiment, after the ring brazing material 50 is fitted in advance to the outside of the U-shaped tube 40, the U-shaped tube end portion 41 is connected to the large-diameter portion 612 of the connection auxiliary portion 60 and the end portion 21 of the hairpin tube 20. The ring brazing material 50 that is inserted into the gap and then fitted to the outside of the U-shaped tube 40 is installed in the expanded portion 614 of the connection auxiliary portion 61, but the ring brazing material 50 is installed in the expanded portion 614. The U-shaped tube end portion 41 may be inserted into the gap between the large diameter portion 612 of the connection assisting portion 60 and the end portion 21 of the hairpin tube 20.

  According to said structure, the location where the hairpin pipe | tube 20 and the U-shaped pipe | tube 40 fit is covered with the connection auxiliary | assistant part 60, Furthermore, as for the connection auxiliary | assistant part 61, the small diameter part 611 is the hairpin pipe | tube 20, and The large diameter portion 612 is joined to the U-shaped tube 40, respectively. Therefore, the hairpin tube 20 and the U-shaped tube 40 are connected in a state where airtightness is ensured.

  As described above, the inner peripheral surface of the end portion 41 of the U-shaped tube 40 is connected so as to fit the outer peripheral surface of the end portion 21 of the hairpin tube 20, and the outer peripheral surface of the hairpin tube 20 and the U-shaped tube 40. Since the outer peripheral surface of the U-shaped tube 40 and the outer peripheral surface of the hairpin tube 20 are joined by the connection auxiliary portion 61 that continuously covers the outer peripheral surface of the brazing material, the brazing material flows into the hairpin tube 20. Therefore, it is possible to prevent a decrease in heat exchange efficiency due to an increase in pressure loss and clogging of the brazing material in the flow path in the hairpin tube 20.

  In the present embodiment, the connection pipe connected to the hairpin tube 20 is the U-shaped tube 40, but this is not limited as long as it is a component that connects the flow path in the hairpin tube 20, for example, a three-way vent pipe or the like. The same effect as the invention can be exhibited.

  Next, it is the heat exchanger 1 which concerns on 2nd Embodiment using this invention, Comprising: The manufacturing process for the suitability confirmation of the welding at the time of manufacture of the heat exchanger 1 is demonstrated using FIG. 7 thru | or FIG. . Except for the addition of the brazing filler metal 52 and the manufacturing process, other configurations are the same as those of the first embodiment, and thus detailed description other than the added configuration is omitted.

  Conventionally, in welding by placing brazing using a ring brazing material as in the present invention, whether or not welding has been performed so as to sufficiently establish airtightness has been confirmed by visual inspection of the joint. More specifically, the determination was made based on whether or not the gap A in FIG. 7 is filled with the brazing material over the entire circumference.

  In Example 1, at the time of welding, as shown in FIG. 6, the ring brazing material 50 is melted and flows between the U-shaped tube 40 and the large-diameter portion 612 by its own weight. Further, the ring brazing material 50 also flows between the hairpin tube 20 and the small diameter portion 611. As a result, the U-shaped tube 40 and the large-diameter portion 612, and the hairpin tube 20 and the small-diameter portion 611 are welded to form joint portions 54 and 53, whereby the hairpin tube 20 and the U-shaped tube 40 are hermetically sealed. Connected in a secure manner.

  However, since there is no means for confirming whether or not the brazing has turned until the airtightness is sufficiently established between the inner peripheral surface of the small diameter portion 611 and the outer peripheral surface of the hairpin tube 20, the welding can be divided into two steps. preferable. Hereinafter, the manufacturing process of the heat exchanger 1 in this embodiment is demonstrated in detail.

  FIG. 7 shows a state where each hairpin tube 20 is expanded and each hairpin tube 20 and the fin set 10 are joined, and further, the large-diameter portion 612 of the connection auxiliary portion 61 of the auxiliary tube plate 60 and the hairpin tube. A small-diameter ring brazing material 52 is disposed in the gap with the end portion 21 of the 20. If it puts into a furnace in this state (1st welding process), as shown in FIG. 8, the small diameter brazing filler metal 52 will melt | dissolve and the auxiliary | assistant tube plate 60 and the hairpin tube 20 will be welded, and it will become the junction part 53, and joining. In the part 53, it connects in the state by which airtightness was ensured with the brazing material.

  Here, although it is determined by welding of the joint portion 53, it can be visually confirmed from above whether airtightness is sufficiently established. Specifically, the determination is made based on whether or not the joint portion 53 is filled with the brazing material over the entire circumference.

  Next, as shown in FIG. 9, the end portion 41 of the U-shaped tube 40 is inserted into the gap between the large-diameter portion 612 of the connection assisting portion 61 of the auxiliary tube plate 60 and the end portion 21 of the hairpin tube 20. At this time, the inner diameter of the end 41 of the U-shaped tube 40 is slightly larger than the outer diameter of the hairpin tube 20, and the outer diameter of the U-shaped tube 40 is slightly smaller than the inner diameter of the large-diameter portion 612 of the connection assisting portion 30. After the insertion, the ring brazing material 50 fitted in advance to the outside of the U-shaped tube 40 is placed in the furnace in the state where the ring brazing member 614 of the connection auxiliary portion 61 is installed (second welding step).

  The ring brazing material 50 is melted by being placed in the furnace as shown in FIG. 9 and flows between the U-shaped tube 40 and the large diameter portion 612 by its own weight. As a result, as shown in FIG. 10, the U-shaped tube 40 and the large-diameter portion 612 are welded to form the joint portion 54, and the joint portion 54 is connected in a state where airtightness is ensured by the brazing material.

  According to said structure, the location where the hairpin tube 20 and the U-shaped tube 40 fit is covered with the connection auxiliary | assistant part 61 of the tube plate 60 with an auxiliary | assistant, Furthermore, as for the auxiliary | assistant part 61, the small diameter part 611 is a hairpin. The pipe 20 and the large diameter portion 612 are joined to the U-shaped pipe 40, respectively. Therefore, the hairpin tube 20 and the U-shaped tube 40 are connected in a state where airtightness is ensured.

  Note that the small-diameter ring brazing material 52 melted in the first welding process may flow down during the second welding process, and the connection state between the auxiliary tube plate 60 and the hairpin tube 20 by the joint portion 53 may not be maintained. Therefore, a structure in which the melting point of the ring brazing material 50 is lower than the melting point of the small-diameter ring brazing material 52 may be used. By doing so, the temperature of the furnace in the second welding process is set lower than the temperature of the furnace in the first welding process without melting the joint 53 formed by the small-diameter ring brazing material 52 during the second welding process. The ring brazing material 50 can be melted to form the joint 54.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 10 Fin assembly 11 Laminated fin 11a Fin 12 Tube plate 12a Protrusion part 13 Through-hole 20 Hairpin tube 21 End part 30 Auxiliary member 31 Small diameter part 31a Notch part 31b Notch part 31c Peep hole 32 Large diameter part 33 Connection Portion 34 Expanded tube portion 40 U-shaped tube 41 U-shaped tube end portion 50 Ring brazing material 60 Tube plate with auxiliary 61 Connection auxiliary portion 611 Small diameter portion 612 Large diameter portion 62 Plate portion

Claims (1)

A plurality of stacked fins;
A pair of tube plates provided at both ends of the fin in the stacking direction;
A plurality of hairpin tubes inserted through through holes provided in the fins and the tube plate;
In a cross-fin type heat exchanger having a connecting tube for connecting different hairpin tubes,
The connecting pipe is composed of a connecting pipe end connected to the hairpin pipe, and a bent pipe continuous with the connecting pipe end.
The connecting pipe end is fitted so that the inner peripheral surface overlaps the outer peripheral surface of the tube end of the hairpin tube,
One of the tube plates on the side facing the connection tube has a connection portion that continuously covers the plate portion, the outer peripheral surface of the hairpin tube and the outer peripheral surface of the connection tube,
The connection auxiliary portion has a smaller diameter portion larger than the outer diameter of the hairpin tube,
A larger diameter portion than the outer diameter of the connecting pipe;
A tapered connection portion that connects the small diameter portion and the large diameter portion and gradually increases in diameter from the small diameter portion side to the large diameter portion side,
The large diameter portion is connected to the plate portion via the small diameter portion,
Formed between the outer peripheral surface of the hairpin tube and the inner peripheral surface of the small-diameter portion, and between the outer peripheral surface of the connecting tube and the inner peripheral surface of the large-diameter portion. A heat exchanger characterized by having a second joint.

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