JP2000193388A - Corrugated fin and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve working efficiency in the manufacturing process of a core assembly process, a joint process, or the like, and at the same time the quality of a heat exchanger. SOLUTION: In a corrugated fin, a part where mechanical strength is increased due to machining cure is widened, and at the same time the sectional shape of a bending part 131 is set to an elliptical shape so that the radius of curvature is increased toward a top part 131a of the bending part 131, thus bending the bending part 131 before a plane part 132 for preventing the buckling deformation of the plane part 132, and hence improving the working efficiency of a core assembly process even if a load P is applied to the bending part 131. Also, since the radius of curvature of the bending part 131 is large, the contact area between a tube 110 and a fin 130 can be increased, thus securely brazing the tube 110 to the fin 130, and hence improving the quality of a heat exchanger.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrugated fin for a heat exchanger formed in a wave (sinusoidal) shape, and is effective when applied to a radiator or a condenser.

[0002]

2. Description of the Related Art As shown in FIG. 7B, a bent portion (a peak portion and a valley portion) of a corrugated fin has a shape (round-top shape) obtained by bending a thin plate material into an arc shape with a substantially constant radius of curvature. ) Is common.

[0003]

As shown in FIG. 7A, the core of the heat exchanger is assembled by alternately stacking corrugated fins 130 and tubes 110 (core assembling step). Thereafter, they are integrally joined by joining means such as brazing (joining step).

In this core assembling step, as shown in FIG. 7B, a load P (a force from the peak to the valley or a direction from the valley to the peak) compressing the corrugated fin 130 is bent. Therefore, there is a possibility that the corrugated fin 130 may be buckled and deformed in the flat portion 132 connected to the bent portion 131. For this reason, there is a high possibility that the workability of the core assembling process is deteriorated.

The bent portion 1 of the corrugated fin 130
If the radius of curvature of 31 is small, the contact area between the tube 110 and the corrugated fin 130 is small during the joining step, so that it is difficult to supply a sufficient brazing material to the contact portion between the tube 110 and the corrugated fin 130, resulting in poor brazing. And the quality of the heat exchanger is likely to be degraded.

SUMMARY OF THE INVENTION In view of the above, the present invention improves workability during a manufacturing process such as a core assembling process and a joining process, and
An object is to prevent the quality of a heat exchanger from being improved.

[0007]

The present invention uses the following technical means to achieve the above object. Claim 1
In the invention described in Item 3, the bent portion (13
The cross-sectional shape of 1) is substantially elliptical.
Thereby, even when the above-mentioned load P acts on the bent portion (131) during the core assembling process, the radius of curvature is larger than that of the round-top bent portion.
1) is bent before the flat portion (132), and the bent portion (13) is bent.
The load P is absorbed in 1). Therefore, the plane portion (13
Since 2) can be prevented from being buckled, the workability in the core assembling process can be improved.

Further, since the radius of curvature is larger than that of the round-top bent portion, the contact area between the tube and the corrugated fin can be increased, so that a sufficient amount of brazing material is supplied to the contact portion between the two. And it is possible to reliably braze the two. As described above, according to the present invention, it is possible to improve the workability of the core assembling step, prevent the brazing failure between the tube and the corrugated fin, and improve the quality of the heat exchanger.

Incidentally, the reference numerals in parentheses of the above means are examples showing the correspondence with specific means described in the embodiments described later.

[0010]

FIG. 1 is a front view of a condenser 100 in which a heat exchanger according to the present invention is applied to a condenser (condenser) of a refrigeration cycle.
In FIG. 1, reference numeral 110 denotes a plurality of flat aluminum tubes (hereinafter, abbreviated as tubes) through which a refrigerant (fluid) flows. Both ends of the tubes 110 in the longitudinal direction are inserted into the header tank 120.

An aluminum corrugated fin (hereinafter abbreviated as a fin) 130 having a number of bent portions (peaks and valleys) 131 and formed in a wave shape is provided between the tubes 110. The fins 130 are
It is joined to the tube 110 outside the bent portion 131. Then, as shown in FIG. 2A, the cross-sectional shape of the bent portion 131 has two relatively small curvature radii R1 and R2 such that the radius of curvature increases toward the top 131a of the bent portion 131. First and second arc portions 131b, 13 having
Third arc portion 131 having a large radius of curvature R3 between portions 1c
It is formed in a substantially elliptical shape so as to smoothly connect at d.

In FIG. 2B, reference numeral 134 denotes the fin 13.
A louver in the shape of an armored window formed by cutting and raising a part of the zero (a flat part 132 connected to the bent part 131). The louver 134 increases the thickness of the temperature boundary layer of the air passing through the fin 130. To improve the heat transfer coefficient. Next, a method for manufacturing the capacitor 100 will be described.

First, a method of manufacturing the fins 130 (fin manufacturing process) will be described using a fin manufacturing apparatus 200 shown in FIG. 3 as an example. In FIG. 3, reference numeral 210 denotes a material roll (uncoiler) around which a band-shaped fin material (thin plate material) 211 is wound, and the fin material 211 taken out from the material roll
Is tensioned by a tension device 220 that applies a predetermined tension to the fin material 211.

The tension device 220 includes a weight tension portion 221 that applies a constant tension to the fin material 211 by gravity, a roll 222 that rotates as the fin material 211 advances, and a predetermined force applied to the fin material 211 via the roll 222. Spring means 22 for applying tension
3 and a roll tension portion 223 composed of

The reason why a predetermined tension is applied to the fin material 211 by the tension device 220 is that the fin height h (see FIG. 2B) of the fin bent and formed by the fin forming device 230 described later is kept constant. To do that. The bent portion 13 is attached to the fin material 211 to which a predetermined tension is given by the tension device 220.
This is a fin forming device that forms a louver 133 on a flat portion 132 (see FIG. 2B) connected to a bent portion 131 while forming a louver 133.

The fin forming apparatus 230 includes a pair of gear-shaped forming rollers 231. A louver 133 is formed on the tooth surface of the tooth portion 232 of the forming roller 231 as shown in FIG. A cutter 232a is provided. Further, the tip 231b of the forming roller 231
Is formed in a concave shape composed of two protrusions 231c and 231d, and the tooth bottom 231e is
It is formed in a convex shape corresponding to b.

For this reason, the fin material (band-shaped thin plate material) 2
11 is fed in the longitudinal direction while forming rollers 231
When the fin material 211 passes through the gap, it is bent along the teeth 232 to form the bent portion 131 and the louver 134, and the cross-sectional shape of the bent portion 131 is in the feed direction D1 of the fin material 211 (see FIG. 3). A substantially elliptical shape is formed so that the corresponding direction D2 becomes the major axis direction (fin forming step).

Note that, of the two protrusions 231c and 231d, the protrusion 231c that comes into contact with the fin material 211 first.
As shown in FIG. 4, the radius of curvature r1 of the distal end portion is set to be smaller than the radius of curvature r2 of the distal end portion of the projection 231d that comes into contact later. Also, in FIG.
Numeral 0 denotes a feeding device for sending out the fin material 211 after the fin forming process to the next process (a shrinking process for adjusting the pitch of the fins 130 by pressing and shrinking the fins formed in the fin forming device 230). The fin forming device 230 includes a pair of gear-shaped feed rollers 241 having a reference pitch substantially equal to the distance between the bent portions 131 formed in the fin forming device 230.

Next, a fin manufacturing process (fin manufacturing apparatus 2)
00)) and the tube 110 are laminated and assembled (see FIG. 1), and the header tank 120 is inserted into the tube 110, and these 110, 1
20 and 130 are fixed by a jig (not shown) (core assembling step). Then, the tube assembled in the core assembling step is heated in a furnace, and the tube 110 and the header tank 1 are heated.
The fins 20 and the fins 130 are joined by brazing (joining step).

Incidentally, the header tank 120 and the tube 1
30 is a coating (cladding) on the surface of the header tank 120
The tube 110 and the fins 130 are brazed by the brazing material coated on both front and back surfaces of the fins 130. Next, features of the present embodiment will be described. In the core assembling process, the fin 1
Even if a load P (see FIG. 2A) that compresses 30 acts, the fin 130 according to the present embodiment has a larger radius of curvature of the bent portion 131 than the round-top shape.
As is apparent from the following mathematical expression 1 and FIG.
Is bent before the plane portion 132 and the load P
Absorb. Therefore, the buckling deformation of the flat portion 132 can be prevented, so that the workability in the core assembling process can be improved.

[0021]

Δ = (P · R ³ ) / (E · I) · (π / 4−2 / π) δ: buckling displacement P: load R: radius of curvature E: Young's modulus I: secondary section Moment Also, since the radius of curvature is larger than that of the bent portion having the round top shape, the contact area between the tube 110 and the fin 130 can be increased.
Sufficient brazing material can be supplied to the contact portion of
10, 130 can be reliably brazed.

As described above, according to the present embodiment, it is possible to improve the workability of the core assembling step while improving the workability of the tube 11.
Poor brazing between the fins 130 and the fins 130 can be prevented, and the quality of the capacitor can be improved. By the way, since the bent portion 131 is formed by plastically deforming the fin material 211, the mechanical strength of the bent portion 131 increases due to work hardening. Therefore, even in a conventional round top shape formed by bending a thin plate material into an arc shape with a substantially constant radius of curvature, the mechanical strength of the bent portion is increased by work hardening.

However, in the round-top shape, the portion where the mechanical strength is increased by work hardening is, as shown in FIG. 6B, a bent portion (thick dashed line portion) bent in an arc with a constant radius of curvature. In the present embodiment, on the other hand, in the present embodiment, the bent portion 131 is moved in the feed direction D1 of the fin material 211.
Since it is formed in a substantially elliptical shape (oval top shape) so that the direction D2 corresponding to the (longitudinal direction of the corrugated fin) becomes the major axis direction, the machine is hardened by work hardening as compared with the round-top bent portion. The portion where the target strength is increased becomes wider (see FIG. 6A).

On the other hand, in the shrinking step, a force for compressing and shrinking the fins 130 from the longitudinal direction of the corrugated fins (hereinafter, this force is referred to as a compressing force F) must be applied to the fins 130. When the compressive force increases, the louver 13
Due to the residual strain at the time of forming the fins 130, the fins 130 are asymmetrically arranged such that the radius of curvature of the bent portion 131 decreases from the center of the fins 130 in the width direction (the direction perpendicular to the length direction of the corrugated fin) toward the end. Since the fins 130 are deformed, when the pitch of the fins 130 is corrected to be widened, the entire fins 130 are deformed in an arc shape.

On the other hand, in the oval-top fin 130 according to the present embodiment, since the work hardening range of the bent portion 131 is larger than that of the conventional round-top fin, the residual strain when the louver 134 is formed is reduced. Due to the effect of
The fin 130 can be prevented from being asymmetrically or arcuately deformed. In the above-described embodiment, the corrugated fin according to the present invention is applied to the condenser. However, the present invention is not limited to this, and can be applied to other heat exchangers such as a radiator.

[Brief description of the drawings]

FIG. 1 is a front view of a capacitor according to an embodiment of the present invention.

FIG. 2A is an enlarged view of a bent portion, and FIG. 2B is a perspective view of a tube and a fin.

FIG. 3 is a schematic diagram of a fin manufacturing apparatus.

FIG. 4 is an enlarged view of a portion A in FIG. 3;

FIG. 5 is a graph showing a relationship between weight and displacement.

FIG. 6A is an enlarged view of a bent portion of a corrugated fin according to the present embodiment, and FIG. 6A is an enlarged view of a bent portion of a corrugated fin according to a conventional technique.

FIG. 7A is a front view of a heat exchanger having a corrugated fin according to the related art, and FIG. 7B is an enlarged view of a bent portion of the corrugated fin according to the related art.

[Explanation of symbols]

110 ... tube, 130 ... corrugated fin, 131
... Bends.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B21D 53/08 B21D 53/08 K

Claims (4)

[Claims] 1. A corrugated fin for a heat exchanger having a plurality of bent portions (131) and a plurality of flat portions (132) formed in a thin plate material (211) and having a corrugated shape. The cross-sectional shape of the corrugated fin is substantially elliptical so that the radius of curvature increases toward the top (131a) of the bent portion (131). 2. A plurality of bent portions (131) and flat portions (132) are formed by a pair of gear-shaped forming rollers (231) while feeding a belt-shaped thin plate material (211) in the longitudinal direction. A corrugated fin for a heat exchanger having a wavy shape, wherein the cross-sectional shape of the bent portion (131) is
A corrugated fin, which is formed in a substantially elliptical shape so that a direction (D2) corresponding to the feed direction (D1) in 1) is a major axis direction. 3. A plurality of bent portions (131), flat portions (132) and louvers (131) are fed by a pair of gear-shaped forming rollers (231) while feeding the belt-shaped thin plate material (211) in its longitudinal direction. 133) is a corrugated fin for a heat exchanger formed into a corrugated shape, wherein the cross-sectional shape of the bent portion (131) is the same as that of the thin plate material (21).
A corrugated fin, which is formed in a substantially elliptical shape so that a direction (D2) corresponding to the feed direction (D1) in 1) is a major axis direction. 4. The method of manufacturing a corrugated fin (130) according to claim 1, wherein the tooth tips (231) of a pair of gear-shaped forming rollers (231) are provided.
b) has a concave shape composed of two protrusions (231c, 231d), and its root (231e) has a convex shape corresponding to the tooth tip (231b), and the band-shaped thin plate (211) has a longitudinal direction. A corrugated fin manufacturing method, wherein a number of bent portions (131) are formed by the forming roller (231) while forming the corrugated fins.