JP2000094079A - Heat exchanger fin and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger fin which is hard to generate a crack in the flare formed at a tip part of a cylindrical body of collared inserting hole even in the case a thin and hard metal plate short of ductility. SOLUTION: In the heat exchanger fin 10 in which the collar 20 formed with flares 18 at a tip part so as to encircle around inserting hole to insert a heat exchange tube is erected on a metal plate 12, the bulged part bulged outward from two places of the tip part of the collar 20 is the flare 18 of oval shape formed as interposing and symmetrical to an inserting hole 16, each of the bulged parts forming the flare 18 are formed to a height equal from the metal plate 12 face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fin for a heat exchanger and a method of manufacturing the same, and more particularly, to a fin having a flare formed at a distal end thereof so as to surround an insertion hole into which a heat exchange tube is inserted. The present invention relates to a fin for a heat exchanger in which a collar having a height is erected on a metal plate and a method of manufacturing the fin.

[0002]

2. Description of the Related Art Heat exchanger fins used as heat radiating portions of heat exchangers such as automotive coolers and room coolers are formed by inserting a plurality of collars having a predetermined height into a thin metal plate such as a rectangular aluminum plate. Holes are dotted. In the heat exchanger including the heat exchanger fins, after stacking a plurality of heat exchanger fins so that the collared insertion holes formed in the heat exchanger fins match, the heat exchanger fins are inserted into the collared insertion holes. A heat exchange tube made of a metal having high thermal conductivity such as copper inserted therein is expanded to form a heat exchanger fin and a heat exchanger tube integrally. Such heat exchanger fins are industrially manufactured by, for example, the draw processing method shown in FIG. 8 or the drawless processing method shown in FIG. In the drawing method shown in FIG. 8, a truncated cone-shaped or column-shaped shallow container 106 is formed on a thin metal plate 100 such as aluminum [step (i)]. The diameter of the opening of the shallow container portion 106 that opens into the metal plate 100 is larger than the opening diameter of the insertion hole with a collar to be formed. Next, a drawing process for gradually increasing the height while reducing the diameter of the shallow container portion 106 is performed [(ii) (iii) (i
v) process]. The cylindrical body 104 is formed by performing a boring process and a burring process on the bottom surface of the container portion 109 having a predetermined height by performing the drawing process (step (v)). The flare 105 is formed by bending (step (vi)).

[0005] In the drawless processing method shown in FIG. 9, a perforation processing and a burring processing are performed on a metal plate 100 to form a perforation hole 102 whose peripheral edge is surrounded by a formed protruding piece 102 [( a)], while extending the diameter of the perforated hole 101 by performing ironing on the protruding piece 102 to form a cylindrical body 104 having a predetermined height [step (b) and (c)]. . Next, the cylindrical body 1 having a predetermined height
The flare 105 is formed by bending the tip of the substrate 04 [step (d)]. When the fins for heat exchangers are stacked, the flare 105 formed by the processing method shown in FIG. 8 or 9 and the flare 105 formed on the outer periphery of the distal end of the cylindrical portion 104 is used for another heat exchanger. The flare 105 is brought into contact with the metal plate of the fin to determine the distance between the heat exchanger fins.

[0004]

In the working method shown in FIGS. 8 and 9, a bottom surface of the container portion 109 or a metal plate 100 formed by performing a drawing process is usually formed by performing a boring process. The holes are circular. Further, the flare 105 formed at the distal end of the cylindrical body 104 of the insertion hole with the collar formed by the processing method shown in FIG. 8 or 9 also substantially extends over the entire outer circumference of the distal end of the cylindrical body 104. It is formed with equal width. However, in recent years, the demand for lighter heat exchangers and the like has increased, and in order to reduce the weight of heat exchanger fins,
Further, it is required to form an insertion hole with a collar in the thin metal plate 100. On the other hand, metal plate 1
Even if the thickness of the metal plate 100 is reduced, a thin and hard metal plate is being used as the metal plate 100 forming the insertion hole with a collar in order to maintain the mechanical strength and the like of the heat exchanger fin.

As described above, a thin and hard metal plate has poor spreadability and poor press workability as compared with a thick and soft metal plate. In particular, the cylindrical body 1
When the flare 105 is formed by bending the tip portion of the flare 104, a tensile force acts in the outer circumferential direction of the flare 105, but when a thin and hard metal plate with poor spreadability is used, FIG. As shown, a crack 106 may occur in the flare 105. This is because the tip of the flare 105 is most extended. Therefore, an object of the present invention is to provide a heat exchanger fin in which a flare formed at the distal end of a cylindrical body of an insertion hole with a collar is less likely to crack even if a thin and hard metal plate having poor spreadability is used. It is to provide a manufacturing method thereof.

[0006]

As a result of repeated studies to solve the above-mentioned problems, the present inventor has found that the flare formed at the tip of the collar of the collar-made insertion hole has an elliptical shape, so that the cylindrical body can be formed. When the flare was formed by bending the tip portion of the flare, it was found that the flare was hardly cracked, and the present invention was reached. That is, the present invention provides a heat exchanger fin comprising a metal plate having a collar having a predetermined height and a flare formed at a tip end thereof, which surrounds an insertion hole into which a heat exchange tube is inserted. In the above, an overhang portion formed by projecting outward from two places at a tip end portion of the collar is an elliptical flare formed by sandwiching the insertion hole, and the flare is formed. Each of the overhang portions is formed at an equal height from the surface of the metal plate.

[0007] The present invention also provides a heat exchanger comprising a metal plate having a collar of a predetermined height with a flare formed at the end thereof so as to surround an insertion hole into which a heat exchange tube is inserted. When manufacturing the exchanger fins, the metal plate is subjected to drawing processing to form a cylindrical or frustoconical container portion, and then an piercing hole is formed in the bottom surface of the container portion to form an elliptical hole. Processing and burring for burring the perforated hole were performed, and two convex portions were formed along the circumferential direction of the insertion hole so as to surround the periphery of the insertion hole perforated in the metal plate. Forming a cylindrical body with a concave-convex tip, and then simultaneously pressing the two convex portions of the tubular body, an overhanging portion that protrudes outward from two places at the distal end of the collar. Forming an elliptical flare formed by sandwiching the insertion hole. As, in the heat exchanger manufacturing method of the fins, characterized by bending.

Further, the present invention provides a heat exchanger comprising a metal plate having a collar having a predetermined height with a flare formed at a tip end thereof so as to surround an insertion hole into which a heat exchange tube is inserted. When manufacturing the fins for the exchanger, after performing piercing processing for drilling an elliptical drilling hole and burring processing for burring the drilling hole in the metal plate, the periphery of the formed opening hole is removed. The surrounding protruding piece is subjected to an ironing process so as to surround the periphery of the insertion hole formed in the metal plate so as to surround the periphery of the insertion hole. A body is formed, and then the two convex portions of the cylindrical body are simultaneously pressed, and the projecting portions projecting outward from two places at the tip of the collar sandwich the insertion hole. Bend to form an elliptical flare formed by DOO is also a method for manufacturing a heat exchanger fins, wherein.

When the tip of the cylindrical body is pressed and bent to form a flare having a substantially constant width over the entire circumference of the tip of the collar, the flare is formed in the circumferential direction of the outer peripheral edge of the flare. A stronger tensile force acts than the vicinity of the inner circumference. Furthermore, on the tip end surface of the cylindrical body forming the outer peripheral edge of the flare, there are a cut surface cut by the punch used for the boring process, and a fractured surface cut by the punch and broken. The cross section is a rough and rough surface and is also a hardened surface. For this reason, when forming a flare by pressing the tip of the tubular body, if a strong tensile force acts on the outer peripheral edge of the flare in the circumferential direction, cracks are likely to be generated from the outer peripheral edge of the flare. In this regard, according to the present invention, the flare formed at the tip of the collar is such that the overhang is formed intermittently along the outer periphery of the collar,
During flaring, the tensile force acting on one of the overhangs has little effect on the other overhangs. For this reason, when forming the flare by pressing the tip of the tubular body, it is possible to prevent a tensile force enough to generate a crack from acting in the circumferential direction of the outer peripheral edge of the flare, and the crack is formed from the outer peripheral edge of the flare. It can be prevented from occurring.

Further, when manufacturing a heat exchanger fin having an insertion hole with a collar, it is necessary to set the height of a cylindrical body, which is pressed to form a flare, to a metal plate to a predetermined height. In conventional heat exchanger fins, the height to the metal plate must be a predetermined height over the entire circumference of the tip of the cylindrical body, and the entire cylindrical body is drawn or ironed to a predetermined height. It is necessary to. On the other hand, in the method for manufacturing a fin for a heat exchanger having the insertion hole with the collar of the present invention, the tip of the tubular body that is pressed and bent to form a flare is formed into an uneven shape having convex portions formed at equal intervals. Since it is formed at the tip, the height from the tip of the convex portion to the metal plate can be the height of the cylindrical body, and the height from the metal plate to the predetermined height over the entire circumference of the tip of the cylindrical body. Compared with the conventional method for manufacturing a heat exchanger fin, a collar having a predetermined height can be easily formed by press working.

[0011]

FIG. 1 is a perspective view showing an example of a heat exchanger fin according to the present invention. The heat exchanger fin 10 shown in FIG. 1 is a rectangular aluminum metal plate 12.
A plurality of collared insertion holes 14, 1
4 ... are provided. Insert hole 14 with this collar
Is formed with a collar 20 having a predetermined height and a flare 18 formed at a distal end portion so as to surround the insertion hole 16 into which the heat exchange tube is inserted. Such a flare 18
As shown in the plan view of FIG. 2, the protrusions 18 a are formed in an elliptical shape, and protrude outward from two places at the front end of the collar 20. Is formed. Between the overhang portions 18a, 18a,
A narrow portion 18b formed narrower than the sticking portion 18a is formed.

A-A of the insertion hole 14 with a collar shown in FIG.
FIG. 3 is a cross-sectional view taken along the plane. As shown in FIG.
A flat portion is formed on the overhang portion 18a forming the portion 8. When the plurality of heat exchanger fins 10 are stacked, the flat portion of the overhang portion 18a forms the back surface of the other heat exchanger fins (the insertion holes 14 with the collars of the metal plate 12 are formed). (A surface opposite to the surface on which the fins are formed) and supports other heat exchanger fins.
Therefore, the flat portions of the overhang portions 18a, 18a are formed at the same height from the surface of the metal plate 12, so that other heat exchanger fins to be supported can be stably supported. On the other hand, no flat portion is formed in the narrow portion 18b, and the narrow portion 18b has substantially no role of supporting other heat exchanger fins. However, the narrow portion 1 from the surface of the metal plate 12
The height of 8b is preferably formed so that each highest part thereof is equal in height to each flat part of the overhang portion 18a. When the narrow portion 18b is lower than the flat portion of the overhang portion 18a, when a plurality of heat exchanger fins 18 are stacked, a heat exchange tube inserted into the insertion hole 16 of the heat exchanger fin 18 between the fins. Are exposed, that is, so-called red eyes, which tend to be unfavorable in terms of appearance and thermal efficiency. In addition, as shown in FIG. 3, the narrow portion 18b is also bent outward from the inner wall of the insertion hole 16, so that the heat exchange tube can be inserted smoothly, which is preferable.

FIG. 4 shows an example in which the heat exchange fin 10 having the insertion hole 14 with the collar shown in FIGS. 1 to 3 is manufactured by the drawing method shown in FIG. In FIG. 4, the container portion 22 having a predetermined height of the metal plate 12 made of aluminum shown in FIG. 4A is obtained by the steps similar to the steps (i) to (iv) of the drawing process shown in FIG. be able to. The bottom surface 24 of the obtained container part 22 of FIG.
Then, a boring process is performed to form a boring hole 26 (step (b)). As shown in FIG. 5, the perforated hole 26 is
Has a smaller area than the bottom surface 24 and has an elliptical shape.
Next, a perforation hole 26 formed in the bottom surface 24 of the container portion 22 is formed.
Is subjected to burring to form a cylindrical body 28 whose tip is formed in an uneven shape [step (c)].
A convex portion 28a and a concave portion 2
8b are formed, and two convex portions 28a (concave portions 28a) are formed.
b) is formed in the circumferential direction of the cylindrical body 28. The protruding portion 28a is formed in the elliptical perforated hole 26 shown in FIG.
6a, and the concave portion 28b is formed by a portion 26b along the short axis in the elliptical hole 26 shown in FIG.

Thereafter, by pressing the concave and convex tips of the cylindrical body 28 and simultaneously pressing and flattening the two projections 28a, the tension projecting outward from the two places at the tip of the collar 20 is obtained. The elliptical flare 1 shown in FIG. 2, in which the projections 18 a and 18 a are formed symmetrically with the insertion hole 14 interposed therebetween.
8 can be formed [step (d)]. By pressing at this time, the convex portion 28a is pressed until it is flattened, and at the same time, a part of the tip portion of the concave portion 28b is pressed, as shown in FIG. 2 or FIG. The narrow portion 18b can also be formed. The formed narrow portion 18b
Is preferably approximately equal to the height of the overhang portion 18a. In the method for manufacturing the heat exchanger fins shown in FIG. 4, a drilling step of drilling an elliptical drilling hole 26 in the bottom surface 24 of the container section 22 [step (b)].
And a burring step (step (c)) of burring the perforated hole 26 may be sequentially performed as separate steps. Also, the boring process and the burring process are performed in one step, that is, in the mold including the upper mold and the lower mold, from when the upper mold starts descending in the lower mold direction to when the bottom dead center is reached. Is also good.

Next, FIG. 6 shows an example in which the heat exchanger fin 10 in which the insertion hole 14 with the collar shown in FIGS. 1 to 3 is formed by the drawless processing method shown in FIG.
In the drawless processing method, a perforating process is performed on the metal plate 12 to form a perforated hole 30 (step (a)). This perforated hole 30 is formed in an elliptical shape as shown in FIG. Next, a burring process for burring the perforated hole 30 is performed to form a burring hole 34 whose periphery is surrounded by the formed protruding pieces 32 [step (b)].
While expanding the diameter of the burring hole 34, the protruding piece 32 is subjected to ironing and extended to form a cylindrical body 36 having a predetermined height with an uneven tip (step (c)). A convex portion 36a and a concave portion 36
b are formed, and two convex portions 36a (concave portions 36a) are formed.
b) is formed in the circumferential direction of the cylindrical body 36. In the elliptical hole 30 shown in FIG. 7 formed in the metal plate 12,
a, and the concave portion 30b is formed by a portion 30b along the short axis of the elliptical hole 30 shown in FIG.

Thereafter, the uneven tip of the cylindrical body 30 is pressed, and the two protrusions 36a are simultaneously pressed and bent to flatten, so that the collar 20 is stretched outward from the tip of the collar 20 in two directions. The projecting portions 18a, 18a are formed, and the elliptical flare 18 shown in FIG. 2 can be formed [step (d)]. By pressing at this time, the convex portion 36a
Is pressed until it is flattened, and the concave portion 36b
2 or 3 by pressing a part of the tip portion of FIG.
As shown in FIG. 5, a narrow portion 18b narrower than the overhang portion 18a can be formed. It is preferable that the height of the formed narrow portion 18b from the metal plate 12 is substantially equal to the height of the overhang portion 18a. In the method for manufacturing the heat exchanger fins shown in FIG. 6, a step of forming an elliptical hole 30 in the metal plate 12 [step (a)] and a burring step of burring the hole 30 are performed. Step [Step (b)]
And each step may be sequentially performed as a separate step, and the boring process and the burring process are performed in one step (in the mold including the upper mold and the lower mold, the upper mold starts to descend in the lower mold direction). From the time when it reaches the bottom dead center).

In the drawing method shown in FIG. 4, an elliptical hole 26 is formed in the bottom surface 24 of the container 22 as shown in FIG. The insertion hole 14 with a collar higher than the perforation hole 27 (shown by a dashed line in FIG. 5) can be formed. That is, the portion a between the elliptical perforated hole 26 and the circular perforated hole 25 corresponds to the protrusion 28a of the cylindrical body 28 shown in FIG. This is because it contributes to the height and consequently can contribute to the color height.
Further, since the protruding portion 18a is formed by pressing the convex and concave portions of the cylindrical body 28 forming the flare 18 and bending the convex portion 28a, the metal plate 12 It is sufficient that the height up to the predetermined height is sufficient.
It is not necessary to set the height of the entire circumference to a predetermined height. Moreover, when the two protrusions 28a are simultaneously pressed and bent to form the two protrusions 18a, each of the protrusions 18a is intermittently formed along the outer periphery of the collar 20, The tensile force acting on one of the independent overhangs 18a has little effect on the other overhang 18a.

By forming the elliptical hole 26 in the bottom surface 24 of the container 22 in this manner, the insertion hole 1 with a collar that is higher than the circular hole 27 circumscribing the hole 26 is formed.
4, the height of the container portion 22 can be reduced when the insertion hole 14 with a collar having the same height as the circular perforation hole 27 is formed. Therefore, as the metal plate 12, it is possible to use a metal plate that is thinner and harder than a metal plate in which a circular perforation hole 27 is formed to form an insertion hole with a collar. In fact, the height of a flared collar that can be formed around a 10 mm diameter insertion hole 16 in a 0.1 mm thick aluminum metal plate 12 is limited to 2 mm in the conventional drawing method shown in FIG. However, the draw processing method shown in FIG.
The color 20 with the flare 18 was formed.

6, the elliptical hole 30 formed in the metal plate 12 and the circular hole circumscribing the hole 30 are also provided. A portion a can be formed between the hole 31 (indicated by a dashed line) and the projecting piece 32 is ironed while extending the diameter of the burring hole 34 formed by burring the perforated hole 30 and extended. The obtained cylindrical body 3 shown in FIG.
6 and, consequently, the color height.
Further, it is sufficient that the convex portion 36a of the cylindrical body 36 forming the flare 18 has a predetermined height, and it is not necessary to set the height of the entire circumference of the cylindrical body 36 to the predetermined height. When simultaneously pressing and bending 36a to form four overhangs 18a,
The point that the pulling force acting on one of the independent overhang portions 18a hardly affects the other overhang portions 18a is the same as the draw processing method. Therefore, when the insertion hole 14 with a collar having the same height as the circular perforation hole 31 is formed, the height of the cylindrical body 36 can be reduced. For this reason, the degree of ironing performed on the protruding piece 32 can be eased while the opening diameter of the burring hole 34 is enlarged, and even if the metal plate is poor in extensibility and is a thin and hard metal plate, the collared insertion hole 14 having a predetermined height can be obtained.
Can be formed.

In the above description, FIG. 1 shows that the insertion hole 14 with the collar is a rectangular metal plate 12.
Are formed in one line in the long axis direction, but the insertion holes with collars 14) may be arranged in two lines or in a staggered manner. Furthermore,
The tip of the overhang 18 a projecting from the tip of the collar 20 may be a curled portion curled in the direction of the metal plate 12. Such a curled portion is formed only at the tip end of the overhang portion 18a, and the narrow portion 18b (42b)
Is not formed. For this reason, even if the processing oil adhering to the heat exchanger fin obtained by the press working enters the curled portion, it can be easily removed.

[0021]

According to the present invention, even if the metal plate becomes thin and hard, the insertion hole with the collar having a predetermined height can be easily formed, and it is possible to meet the demand for the weight reduction of the heat exchanger.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a heat exchanger fin according to the present invention.

FIG. 2 is a plan view of an insertion hole with a collar 14 formed in the heat exchanger fin shown in FIG.

FIG. 3 is a cross-sectional view of the insertion hole with a collar 14 formed in the heat exchanger fin shown in FIG.

FIG. 4 is a process diagram illustrating an example of a method for manufacturing the heat exchanger fins illustrated in FIG.

FIG. 5 is a plan view illustrating the shape of a perforation hole 26 formed in the step of FIG. 4 (b).

FIG. 6 is a process chart for explaining another example of the method of manufacturing the heat exchanger fin shown in FIG.

FIG. 7 is a plan view illustrating the shape of a perforation hole 30 formed in the step of FIG.

FIG. 8 is a process diagram illustrating an example of a method of manufacturing a conventional heat exchanger fin.

FIG. 9 is a process diagram illustrating another example of a method of manufacturing a conventional heat exchanger fin.

FIG. 10 is a perspective view of an insertion hole with a collar in which a crack has occurred in a flare.

[Explanation of symbols]

 Reference Signs List 10 Fin for heat exchanger 12 Metal plate 14 Insertion hole with collar 16 Insertion hole 18 Flare 18a Overhanging portion 18b Narrow portion 20 Collar 22 Container portion 24 Bottom surface 26, 30 Drilling hole 28, 36 of tubular portion 22 28a, 36a convex portion 28b, 36b concave portion 34 burring hole

Claims (4)

[Claims] 1. A heat exchanger fin comprising a metal plate having a collar having a predetermined height and a flare formed at a tip end thereof, which surrounds an insertion hole into which a heat exchange tube is inserted. An overhanging portion extending outward from two locations at the tip of the collar is an elliptical flare formed with the insertion hole interposed therebetween, the overhanging portion forming the flare Are formed at the same height from the surface of the metal plate. 2. A protruding portion formed by projecting a flare outward from two locations at the tip of the collar, and a narrow portion formed narrower than the protruding portion. The fin for a heat exchanger according to claim 1, which is a flare. 3. A heat exchanger fin having a collar with a predetermined height and a flare formed at a tip end thereof is formed on a metal plate so as to surround an insertion hole into which a heat exchange tube is inserted. At the time of manufacture, after the metal plate is subjected to drawing to form a cylindrical or truncated cone-shaped container portion, piercing is performed to form an elliptical hole in the bottom surface of the container portion, and the piercing is performed. A burring process for burring the installation hole is performed, so that two protrusions are formed along the circumferential direction of the insertion hole so as to surround the periphery of the insertion hole formed in the metal plate. Forming a tubular body, and then simultaneously pressing the two convex portions of the tubular body, and projecting outward from two places at the distal end of the collar into the insertion hole. Bent so as to form an elliptical flare formed A method for producing a fin for a heat exchanger. 4. A heat exchanger fin comprising a metal plate having a collar having a predetermined height and a flare formed at a tip end thereof, surrounding a periphery of an insertion hole into which a heat exchange tube is inserted. At the time of manufacturing, after performing piercing processing for drilling an elliptical drilling hole and burring processing for burring the drilling hole in the metal plate, a projecting piece surrounding the periphery of the formed opening hole is formed. An ironing process is performed to form a cylindrical body having an uneven tip in which two protrusions are formed along the circumferential direction of the insertion hole so as to surround the insertion hole formed in the metal plate. Then, the two convex portions of the cylindrical body are simultaneously pressed, and a projecting portion projecting outward from two places at the tip of the collar is formed with the insertion hole interposed therebetween. Bends to form an elliptical flare Of producing heat exchanger fins.