JPH0712772U - Flat tube for heat exchanger - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a flat tube for a heat exchanger that can be easily assembled at a predetermined position without the inner fin moving in the width direction when the flat tube is assembled. [Structure] A corrugated inner fin is inserted into a tube inner flow passage formed in an oval cross section, and the wavy top portion is joined to an inner wall surface in the tube, and the tube flow passage is formed in a longitudinal direction. A flat tube of a heat exchanger divided into a plurality of flow passages along a. Providing an inwardly projecting protrusion on the inner wall surface of the tube at a position facing the wavy concave portion of the inner fin, b. One or both of the following are provided: a concave portion that is buried outward is provided on the inner wall surface of the tube at a portion facing the wavy top portion of the inner fin.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a flat tube for a heat exchanger having inner fins provided therein for partitioning a plurality of refrigerant flow passages therein.

[0002]

[Prior art]

 Generally, a parallel flow type heat exchanger has inlet and outlet header tanks connected to both ends of a plurality of flat tubes stacked in parallel with each other via corrugated fins, and between both header tanks. The heat exchange medium flows in parallel.

As the flat tube, for example, as shown in FIGS. 7 and 8, a wavy inner fin 22 is inserted inside the tube so that the wavy top portion is inside the tube. A heat exchanger using a flat tube 21 joined to a wall surface 23 and having a tube flow passage divided into a plurality of flow passages along the longitudinal direction is known (for example, JP-A-5-1893).

In this type of flat tube 21, a predetermined forming plate is bent by roll forming or the like to form a tube body having an oval cross section, and the inner fin 22 is inserted into the tube body to set and press it. The inner fin 22 is assembled by crushing with. The overall width of the inner fin 22 is formed to be narrower than the width of the tube body in order to facilitate insertion.

[0005]

[Problems to be solved by the device]

 In the flat tube with the inner fin inserted, the inner fin is set on the forming plate, and the forming plate is bent by a press or the like to form the flat tube, so that the tube body and the inner fin are assembled. However, there is a problem that the inner fin moves in the width direction of the tube when the molded plate is bent.

In view of the above, the present invention provides a heat exchanger that can be easily assembled to a predetermined position in an inner fin type flat tube without the inner fin moving in the width direction when the flat tube is assembled. The purpose is to provide flat tubes.

[0007]

[Means for Solving the Problems]

 In the flat tube of the present invention, a corrugated inner fin is inserted into the tube inner flow passage formed in an oval cross section, and the corrugated top is joined to the inner wall surface of the tube, and In the flat tube of the heat exchanger whose passage is divided into a plurality of flow passages along the longitudinal direction, a. Providing an inwardly projecting protrusion on the inner wall surface of the tube at a location facing the wavy concave portion of the inner fin, b. A concave portion that is buried outward is provided on the inner wall surface of the tube at a location facing the wavy top portion of the inner fin.

[0008]

[Action]

 Therefore, when inserting the inner fins into the flat tube and assembling, the wavy tops of the inner fins are locked to the projections or recesses provided on the tube body, or both, so that the inner fins are positioned reliably. It is possible to avoid the disadvantage that the inner fin moves in the width direction as in the conventional case. Furthermore, when a projection is provided on the inner wall surface of the flat tube, the strength of the flat tube is improved by this projection, and when a recess is provided on the inner wall surface of the flat tube, brazing is performed at the recess. Therefore, the strength of the flat tube is improved, and in any case, it is possible to reduce the thickness of the flat tube. Furthermore, since the fillet portion at the top of the inner fin is formed over the projection and the recess of the flat tube during the integral brazing, the brazing property of the fillet portion of the inner fin is improved.

[0009]

【Example】

 A first embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, in the heat exchanger 1 of the present embodiment, a plurality of flat tubes 2 are laminated in parallel with each other via corrugated fins 3, and both end portions of the flat tubes 2 are arranged in parallel with each other. Each of the header tanks 4 is inserted into a tube insertion hole 5 provided in each header tank 4 and integrally joined by brazing. In FIG. 1, 6 is a blind cap, 7 is an inlet joint, and 8 is an outlet joint.

As shown in FIGS. 2 and 3, the flat tube 2 has a tube body 10 formed of a single molding plate and having an oval cross section, and a corrugated tube body 10 that is inserted into the tube body 10. The inner fin 12 is formed. The tube body 10 is formed by bending a single molding plate by roll molding to form an oval cross section, and integrally brazing a joint piece 11 formed by bending the side portion. It is formed by joining. The inner fin 12 is formed to have a lateral width dimension shorter than the width dimension inside the tube body 10, is formed in a wavy shape that undulates in the width direction, and is inserted into the tube body 10 to integrally braze the wavy top portion 12a and the like. Are joined by.

Such a flat tube 2 is set by inserting an inner fin 12 into a tube body 10 formed by bending a molding plate, and crushing the tube body 10 by pressing or the like to form the tube body 10 and the inner fin. The tube body 10 and the inner fin 12 are joined to each other and the joining piece 11 of the tube body 10 is joined to the tube body 10 by integral brazing.

Further, on the inner wall surface of the tube body 10 of the flat tube 2, between each of the wavy top portions 12 a of the inner fin 12, that is, at each of the wavy concave portions of the inner fin 12, A projecting portion 13 projecting toward one side is provided.

In the present embodiment, the projections 13 are provided so as to be continuous along the longitudinal direction of the flat tube 2 as shown in FIG. The width of the protrusion 13 is smaller than the distance between the tops 12a of the inner fins 12 so that the inner fins 12 can be easily inserted. The protrusions 13 are provided on the molding plate in advance at predetermined positions by pressing or the like.

Therefore, in the flat tube of the present embodiment, when the inner fin is inserted into the tube body and assembled, the wavy tops of the inner fins are locked to the protrusions provided on the tube body, Positioning of the fins is ensured, and it is possible to avoid the disadvantage that the inner fins move in the width direction as in the conventional case. Moreover, since the projection is provided on the tube body, the strength of the tube body is improved, and the thickness of the tube body can be reduced. Further, when the inner fin and the tube body are integrally brazed, the fillet portion at the top of the inner fin is formed over the projection of the tube body, so that the brazeability of the fillet portion of the inner fin is improved. .

Next, a second embodiment of the present invention will be described.

In this embodiment, as the projection 13 provided on the tube body 10, as shown in FIG. 4, an oval projection 13 is provided.

That is, between the wavy tops 12a of the inner fins 12 on the inner wall surface of the tube body 10, elliptical protrusions 13 having a predetermined length are intermittently provided at a predetermined interval. ing.

Therefore, also in the present embodiment, the same effect as described above is obtained, and since the projections are provided intermittently, a turbulent flow effect is imparted to the refrigerant flowing through the partition flow passage in which the projections are provided. The heat exchange efficiency can be improved.

Next, a third embodiment of the present invention will be described.

In this embodiment, as the protrusion provided on the tube body 10, a circular protrusion 13 is provided as shown in FIG.

That is, between the wavy tops 12a of the inner fins 12 on the inner wall surface of the tube body 10, circular protrusions 13 having a predetermined diameter are intermittently provided at predetermined intervals. .

Therefore, also in this embodiment, the same effect as that of the second embodiment can be obtained.

Next, a fourth embodiment of the present invention will be described.

In this embodiment, as shown in FIG. 6, the outer wall surface of the tube body 10 is formed into a flat surface, and the outer wall of the inner fin 12 is buried in the inner wall surface of the tube at a position facing the wavy top portion 12a. The recess 14 is provided.

Also in this case, when the inner fins are inserted into the tube body and assembled, the wavy tops of the inner fins are locked in the recesses provided in the tube body, so that the inner fins can be positioned reliably, and It is possible to avoid the disadvantage that the inner fin moves in the width direction as described above. Further, since the outer wall surface of the tube body is formed flat, that is, there is no unevenness on the outer wall surface of the tube body, insertion of the flat tube into the header tank is facilitated, and brazing is also reliable. Further, when the inner fin and the tube body are integrally brazed, the fillet portion at the top of the inner fin is formed over the recessed portion of the tube body, so that the brazeability of the fillet portion of the inner fin is improved and Even if the recess is thin, brazing is performed at this portion, so that the strength of the flat tube is improved overall.

[0027]

[Effect of device]

 As described above, according to the present invention, when the inner fin is inserted and assembled in the flat tube, the wavy top of the inner fin is locked to the projection or the recess provided on the tube body or both. Therefore, the positioning of the inner fin is ensured, and it is possible to avoid the disadvantage that the inner fin moves in the width direction as in the conventional case.

Furthermore, when a protrusion is provided on the inner wall surface of the flat tube, the strength of the flat tube is improved by this protrusion, and when a recess is provided on the inner wall surface of the flat tube, the recess is also affected. Since the brazing is performed in the above, the strength of the flat tube is improved, and in any case, it is possible to reduce the wall thickness of the flat tube. Furthermore, since the fillet portion at the top of the inner fin is formed over the projection and the recess of the flat tube during the integral brazing, the brazing property of the fillet portion of the inner fin is improved.

[Brief description of drawings]

FIG. 1 is a front view of a heat exchanger according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a flat tube.

FIG. 3 is a cross-sectional view of a flat tube.

FIG. 4 is a perspective view of a flat tube according to a second embodiment of the present invention.

FIG. 5 is a perspective view of a flat tube according to a third embodiment of the present invention.

FIG. 6 is a cross-sectional view of a flat tube according to a fourth embodiment of the present invention.

FIG. 7 is a perspective view of a flat tube according to a conventional example.

FIG. 8 is a transverse cross-sectional view of the above flat tube.

[Explanation of symbols]

 1 Heat Exchanger 2 Flat Tube 12 Inner Fin 12a Top 13 Projection 14 Recess

Claims (1)

[Scope of utility model registration request] 1. An inner fin having a wavy shape is inserted into a tube inner flow passage formed to have an oval cross section, and the wavy top portion is joined to an inner wall surface of the tube to form the tube flow passage. A flat tube of a heat exchanger, wherein the flat tube of the heat exchanger is divided into a plurality of flow passages along the longitudinal direction, and the flat tube of the heat exchanger is provided with either or both of the following a and b. Note a. Providing an inwardly projecting portion on the inner wall surface of the tube facing the wavy concave portion of the inner fin. B. A concave portion that is buried outward is provided on the inner wall surface of the tube at a portion facing the wavy top portion of the inner fin.