JPH0127809B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing heat exchanger fins for various air conditioners (room air conditioners, car coolers, etc.).

The shapes of the fins used in heat exchangers such as air conditioners vary depending on the model, and naturally the methods of manufacturing the fins also differ. Fig. 1 shows the shape of the fin 1 that is the object of the present invention, and the conventional method for making the shape of the fin 1 is () flat plate 2 (width W _c × thickness t _p × length A method (2) of adhering and forming rod-shaped material 3 (outer diameter d x height h) on a material 5 (outer diameter d x height h) at intervals of pitch p. A manufacturing method is also known in which both ends of the pipe are cut with a cutting roll 6, and then bent with a bending device 7 and wound around a pipe 8.

However, the method (2) is not only inefficient but also has drawbacks such as poor adhesion and is not suitable for mass production. Furthermore, although the method in () is suitable for mass production, it merely involves cutting the plate and only yields fins with a rectangular cross section.
Note that fins with a rectangular cross section have a disadvantage of poor heat transfer coefficient.

The present invention was proposed in order to eliminate the above-mentioned conventional drawbacks, and aims to provide a method for manufacturing heat exchanger fins that is suitable for mass production and that can manufacture fins with good heat transfer coefficient.

The present invention will be explained below with reference to the embodiments shown in the drawings. Figure 2 A, B, C, and D show an embodiment of the method for manufacturing the fin 1 of the present invention, and the material 2a in Figure 2 A is
(Plate width W _p ×Plate thickness t _p ) is pulled out from the material unwinding roll 9 in FIG. 3 via the pinch roll 10, and is subjected to groove processing by a pair of upper and lower groove forming rolls 11, 11. . By this processing using the grooved forming roll 11, the material 2a is formed into a shape 2a' having an unprocessed flat plate part 2b in the center and rounded uneven parts on both sides, as shown in FIG. A convex portion 3a' which becomes a rod-shaped portion 3a is provided in the portion.

A detailed view of part A in FIG. 2B is shown in FIG. 4, and a cross section from B to B is shown in FIG. The dimensional relationship of each part in FIGS. 4 and 5 is under the following conditions, and the unprocessed flat plate part 2b has a width W _c and a plate thickness t _p . Further, d is the outer diameter of the rod-shaped portion, t ₁ is the plate thickness of the connecting portion between the protrusions 3a' and 3a', which becomes the rod-shaped portion 3a, and b is the width of the connecting portion between the protrusions 3a' and 3a'.
p is the distance between the centers of the convex parts 3a' and 3a', and h is the distance between the centers of the convex parts 3
a′, that is, the length of the rod-shaped portion 3a, t _p =(0.7 to 1.2) d t ₁ =(0.03 to 0.5) d b =(0.2 to 0.4) d.

FIG. 7 shows details of the state in which the shape 2a' of FIG. 2B is formed by the hole-shaped forming rolls 11, 11 of FIG. 3. Next, the material formed into the shape 2a' shown in FIG. In this cutting unit, the convex portion 3 shown in FIGS. 4 and 5
The one cutting roll ₁₃ and 1
Continuously between the flat rolls 14 of
a' is formed into a rod-shaped portion 3a (FIG. 2C). The details of the cutting portion by the cutting roll 13 and the flat roll 14 are shown in FIG.

Figure 9 shows an enlarged view of the main parts in Figure 8,
The cutting edge 13a of the cutting roll 13 has a wrap amount γ=(5-10) _t1 . Here t ₁ ≒
If it is 0.01 mm, the wrap amount γ is approximately 0.05 to 0.1 mm, and with this wrap amount γ, the connecting portion 3b between the convex portions 3a'
(plate thickness t ₁ ) is cut. In other words, as shown in FIG. 15, if the length from the top surface of the protrusion 3a' to the connecting part is l ₁ , and the length to the cutting edge 13a is l ₂ , then l ₂ - _{l 1}
=γ, and the connection portion 3b is disconnected. In addition, in Fig. 9, the lower surface on the opposite side of the connecting part 3b is free and there is no support, but in this state, the cutting edge 1
3a allows the connection 3b to be disconnected. That is, the reason for this is the principle of shear, and since the adjacent bar-shaped protrusions 3a' are connected to each other, if they are pushed further by the amount of overlap γ, they can be naturally cut. In other words, the convex portion 3a' becomes a resistance corresponding to a support.

FIG. 16 shows a cross-sectional view of the flat roll 14. This flat roll 14 has a longitudinal elastic modulus E=100 to 1000 Kg/mm ²
For example, a steel roll whose surface is lined with hard urethane rubber 14a can be used. But E＜100
Kg/mm ² will not break due to elasticity. That is, since the roll is too soft, the convex portion 3a' will be wedged into the flat roll 14 by a dimension δ as shown in FIG. Further, if E>1000 Kg/mm ² , the rod-shaped portion 3a changes due to the cutting resistance during cutting, and good cutting cannot be achieved in any of these cases.

Next, the material 2c (molded product) exiting the cutting unit is transferred to the bending device 1 via pinch rolls 15.
Enter 6. By this bending device 16, the material 2c having the shape shown in FIG. It is bent and formed into the fin 1 as shown in FIG. 2D. Next, the fins 1 leaving the folding device 16 pass through a pinch roll 17 and are wound around a winding roll 18.

FIG. 11 shows another embodiment, in which rod-shaped portions 3a, 3a are provided on both sides of the flat plate portion 2b, like the fin 1 in FIG.
This is the case where the rod-shaped portion 3a is present only on one side of the flat plate portion 2b. Furthermore, the cross-sectional shape of the rod-shaped portion 3 is not limited to only a circular shape as shown in FIGS. 2 and 8, but may be rounded.
Various shapes such as an oval as shown in the figure or a square as shown in FIG. 13 may be used.

As described above in detail, the present invention allows mass production because the fins can be manufactured continuously from plate material. In addition, after forming the plate material into a flat plate part and a rounded uneven part using a groove forming roll,
Since the connecting parts between the convex parts of the same convex-convex shaped part are cut by cutting rolls to form each independent bar-shaped part, these bar-shaped parts have a rectangular cross-section as if the sides of a flat plate were simply cut. Instead, it is easily formed into a round cross section. Therefore, the heat transfer coefficient is improved (approximately 1.5 times) compared to a square cross section, and performance can be improved.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the fin shape targeted in the present invention, Fig. 2 A, B, C, and D are explanatory diagrams sequentially showing the steps of the method of the present invention, and Fig. 3 is an implementation of the method of the present invention. FIG. 4 is a detailed view of section A in FIG. 2B, and FIG.
B sectional view, FIG. 5B is the same side view, FIG. 6 is a C-C sectional view of FIG. Fig. 8 is an enlarged view of the cutting unit section in Fig. 3, Fig. 9 is an enlarged view of the main part in Fig. 8, and Fig. 10 A explains the shape of the stepped portion of the groove forming roll or cutting roll. Figure 11 is a cross-sectional view of the fin with a different shape from that in Figure 6, and Figures 12 and 13 are the cross-sectional shape of the fin in Figure 8. 14 is a side sectional view showing an example of a conventional fin manufacturing apparatus;
FIG. 5 is an explanatory diagram showing a state in which the connecting portion of the material is separated, FIG. 16 is a side sectional view of the flat roll, and FIG. 17 is an explanatory diagram showing the state in which the rod-shaped portion of the material is bitten into the flat roll. Explanation of the main parts of the diagram, 1...Fin, 2a...
Plate material, 2b... unprocessed flat plate part, 2a'... shape having flat plate part 2b and rounded uneven parts, 3a
. . . rod-shaped portion, 3a′ . . . convex portion, 11 .

Claims (1)

[Claims] 1. After forming the plate material into a flat plate part and a rounded concave-convex shaped part using a hole-shaped forming roll, the connecting parts between the convex parts of the concave-convex shaped part are cut with a cutting roll to form each independent rod-shaped part. 1. A method for manufacturing a heat exchanger fin, comprising: forming a fin, and then bending the rod-shaped portion at right angles to the flat plate portion.