JPH0137798Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a needle-like fin forming roll intended to further improve heat exchange efficiency in a heat exchanger equipped with needle-like corrugated fins.

In compact heat exchangers such as car air conditioners and radiators, those having a structure in which corrugated fins are interposed between meandering heat transfer tubes are most commonly used. The appearance of this corrugated heat exchanger is shown in Figs. 1 and 2. In the figure, internal partition wall 1
A connection union 3 is integrally fixed to the end of the heat exchanger tube 1 partitioned by a, and this heat exchanger tube 1
are alternately bent 180 degrees at the bend portions (bent pipe portions), and meander as if sandwiching the corrugated fins 2. In recent years, corrugated fins 2 having the shape shown in FIG. 3 have been adopted with the aim of improving heat exchange efficiency. As shown in the figure, the fins 2b of the corrugated fins 2 have a predetermined gap 2 within the plate thickness.
The corrugated fins 2 and the heat transfer tubes 1 are integrated at the edges 2a of the corrugated fins, and the heat medium flowing inside the heat transfer tubes 1 is formed in parallel with the air passing through the corrugated fins 2. to perform heat exchange.

In order to further improve the heat exchange efficiency while preventing pressure loss, as shown in FIGS. It is desirable to alternately displace them in opposite directions along the line.

By the way, when molding corrugated fins in which the cross section of the fins is circular and the fins are bulged in opposite directions alternately along the plate thickness direction as described above, an example thereof is shown in FIGS. 6 to 8. A roll that simultaneously shapes the cross section of the fin and bulges the fin can be considered. That is, the forming roll 4,
An arcuate groove 7 is provided at the tip of each tooth 6 of the roller 5, and a ladder-shaped material 8 is fed into the forming rolls 4 and 5. Here, disk-shaped presser rolls 9 and 10 are integrally fixed to both end surfaces of the forming rolls 4 and 5, and hold the edge portion 2a of the material 8, so that the teeth of the forming rolls 4 and 5 are engaged with each other. The square fin portion 11 of the material 8 is sandwiched between the groove 7 and the tooth bottom 12, and the square fin portion 11 is inserted into the round rod-like needle-like fin 2b.
Plastically processed. Also, at the same time, forming rolls 4 and 5
Due to the meshing phenomenon, the fins 2b become needle-like fins bent in opposite directions alternately along the thickness direction of the material 8 (vertical direction in FIG. 6), and by bending them into a corrugated shape, A corrugated fin 2 as shown in FIG. 5 is manufactured.

However, such forming rolls have the following drawbacks. First, since the forming roll has presser rolls at both ends, it is expensive. As shown in FIG. 8, since the material 8 is caught between the forming rolls 4 and 5 and the bent portion 2d is formed on the fin 11 itself by the slope 13, the fin 11 tends to separate from the groove 7, making high-speed forming difficult. Further, when forming the bent portion 2d on the fin 11, the edge portion 2a is pulled, and as a result, a bending moment that tends to bend the edge portion 2a in a zigzag shape is applied to the edge portion 2a, and the end face 2e of the edge portion 2a is
becomes a wavy surface and the heat exchanger tube 1 and corrugated fin 2
The area around the wax becomes bad when the parts are brazed together.

Therefore, the object of the present invention is to provide a needle-like fin forming roll that eliminates such drawbacks.

The structure of the present invention to achieve this purpose is as follows:
A forming roll for forming a ladder-like material into needle-like fins, in which edge portions that are substantially parallel to each other are connected by fins provided at approximately equal intervals, and the length in the axial direction of the roll is Teeth corresponding to the length of the fins are formed at approximately equal intervals in the circumferential direction on the outer peripheral surface of the roll, and grooves are formed at the tips of the teeth to shape the cross-sectional shape of the fins from a square to a circle. Features.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 9 shows a processing diagram of a state in which a ladder-shaped material is being formed using the forming roll according to the present invention, and FIG. 10 shows a sectional view taken along the line D--D in FIG. 9. As in Figure 6, forming roll (hereinafter simply referred to as roll)
20 and 21 have teeth 22 extending in the axial direction of the roll.
are formed at approximately equal intervals in the circumferential direction of the roll,
A fin 2 of a ladder-like material 26 is provided at the tip of the tooth 22.
A groove 24 is formed for shaping the cross-sectional shape of 7 from a square to a circle. This roll 20, 21
The total length of the roll is slightly shorter than the length of the fins 27, and the teeth 22 are formed over the entire length of the roll.
6, only the edge portion 29 is attached to the rolls 20, 21.
I'm learning not to get caught up in it. Also, from the axis of the rolls 20 and 21 to the tip of the tooth 22 is r ₂ ,
The distance from the axis of the rolls 20, 21 to the tooth bottom 23 is _r1 .

While rotating the rolls 20 and 21, a ladder-shaped material 26 is fed between the rolls 20 and 21 as shown in FIG. Then, the fin 27, which had a rectangular cross-sectional shape, is compressed between the tooth bottom 23 and the groove 24, and becomes a fin 28 whose cross-sectional shape is circular. In addition, since the fins 27 are formed by being placed alternately in the grooves 24 at the tips of the roll teeth 22 and the tooth bottoms 23, the rolls 20 and 21
The edge portion 29 that moves without being bitten by 1 is bent into a meandering shape. This bent portion is a joint portion between the edge portion 29 and the fin 27, and as a result, a needle-like fin 30 bent in a meandering manner is completed. FIG. 11 shows a perspective view of a needle-shaped corrugated fin 31 obtained by corrugating the needle-shaped fin 30 thus produced. Here, H ₁ is the width of the corrugated fin, H ₂ is the width of the edge, and H ₃ is the distance between the edges. Moreover, FIG. 12 is a sectional view when the corrugated fins 31 are brazed to the heat transfer tubes 32. Forming of needle-like fins using such forming rolls is done by bending the edges to bulge the fins, so there are no irregularities on the end surfaces of the edges, and the brazing between the corrugated fins and the heat exchanger tubes is strong. become.

Other examples of forming rolls are shown in Fig. 13 and Fig. 1.
Shown in Figure 4. In this example, the total length of the roll is longer than that of the previous example. In other words, the total length of the roll is increased by 2W ₂ to make the total length W ₁ =W ₃ +2W ₂ , and notches 25 are formed by the length W ₂ at both ends of the teeth 22 in the rolls 20a and 21a. . The notch 25 is formed into a groove 24 as shown in FIG.
It is formed by removing the tip of the tooth 22a from the bottom of the tooth 22a toward the tooth bottom 23a, and therefore the length from the notch 25 at one end to the notch 25 at the other end, that is, the tooth 22a. The length of the fin 27 is slightly shorter than that of the fin 27.

By such rolls 20a and 21a, the material 26
, the edge portion 29 is bent into a meandering shape with the edge portion 29 housed in the notch 25, and the first edge portion 29 is bent into a meandering shape.
As shown in Figure 0, the total length of the roll is W ₃ , and the shape is the same as that of the needle-like fin formed with a forming roll in which teeth are formed over the entire length.

In the embodiment, only the tips of the teeth at both ends of the roll are cut out, but the cuts may be made up to the base ends of the teeth. Further, the value of W ₃ is limited to be slightly shorter than the length of the fin, but the value of W ₂ is not limited and may be zero as shown in FIG. In other words, it is sufficient as long as it does not hinder the bending of the edge portion.

As described above with reference to the embodiments and drawings, according to the present invention, the teeth with grooves formed on the tips of the teeth are formed to be slightly shorter than the overall length of the fins, so that the cross-sectional shape of the fins made of a ladder-like material It is possible to shape a material from a square to a circle and at the same time bend the edges of the material into a meandering shape. In other words, as a forming roll, it is only necessary to process the teeth and grooves, and the cost of the roll is low.
Furthermore, since the fins themselves are not bent, but the edges extending in the flow direction of the material are bent, the fins are less likely to derail from the grooves and high-speed molding is possible.
Furthermore, since no force is applied in the direction perpendicular to the end face of the helical part during molding of the material, the end face is not uneven and the solder is well-circulated, so that the corrugated fin and the heat exchanger tube are firmly connected.

[Brief explanation of the drawing]

Figures 1 and 2 are front and side views of the corrugated heat exchanger, Figure 3 is a sectional view taken along the line A-A in Figure 1, and Figure 4 is viewed along the line B-B in Figure 3. Cross section, 5th
The figure is a perspective view of a corrugated fin, FIGS. 6 to 8 relate to a conventional needle-like fin forming roll, FIG. 6 is a cross-sectional view of the forming roll as viewed from the axial direction, and FIG.
Figure and Figure 8 show when the material is not bitten, respectively.
A sectional view taken along the line C-C in FIG. 6 when biting, FIGS. 9 and 10 relate to an embodiment of the needle-like fin forming roll according to the present invention, and FIG. 9 shows the axis of the forming roll. FIG. 10 is a sectional view taken along the line D-D in FIG. 9, and FIGS. 11 and 12 are cross-sectional views taken from the core direction, and FIGS. A perspective view showing corrugated fins, a cross-sectional view showing corrugated fins brazed to heat transfer tubes, FIGS. 13 and 14 relate to other embodiments of the forming roll according to the present invention, and
3 is a sectional view corresponding to FIG. 10, and FIG. 14 is an enlarged perspective view of the notch. In the drawing, 20, 20a, 21, 21a are forming rolls, 22, 22a are teeth, 23, 23a are tooth bottoms,
24, 24a are grooves, 25 is a notch, 26 is a material,
27 and 28 are fins, 29 is an edge portion, and 30 is a needle-like fin.

Claims (1)

[Scope of utility model registration request] A forming roll for forming a ladder-like material into needle-like fins, in which edge portions that are substantially parallel to each other are connected by fins provided at approximately equal intervals, and the length in the axial direction of the roll is Teeth corresponding to the length of the fins are formed at approximately equal intervals in the circumferential direction on the outer peripheral surface of the roll, and grooves are formed at the tips of the teeth to shape the cross-sectional shape of the fins from a square to a circle. Features a needle-like fin forming roll.