JPH0446717A - Cutter for molding corrugated fin - Google Patents

Abstract

PURPOSE:To improve heat efficiency of a corrugated fin by extending a blade for shearing a looper up to the maximum outside diameter section of a cutter, and providing a low step part and a notched recess part at an outer end of the blade in the cutter for molding a corrugated fin which is used in a heat exchanger. CONSTITUTION:A blade section 8a is formed by extending an outer end up to the teeth tip circle on the front side in the direction of rotation A with a teeth tip section 9 of a cutter 3 for molding a corrugated fin as the boundary. A blade section 8b is formed, on the other hand, by making is outer end lower than the external end of the blade 8a on the rear side in the direction of rotation A. A low step 17 with difference in level l which is located at the outer end and a notched recess part 18 are formed in the blade 8a on the front side in the direction of rotation A. As for the position of the low step part 17 and the difference in step l, when the blade 8a is provided up to the maximum outside diameter part 21 on the front side in the direction of rotation A, the difference in step l in the low step part 17 becomes 1/3 to 1.75 times fin material. As for the position and depth of the notched recess part 18, it is located at the position which is obtained by multiplying the height H of angle 20 of the blade 8b on the rear side by 1 to 2, and it is made deeper than the difference in step l the low step part 17.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a cutter for forming corrugated fins used in heat exchangers.

<Prior Art> Full gate fins are used in heat exchangers such as car coolers and radiators. A conventional example of this corrugate fin manufacturing apparatus is explained with reference to FIG. 6. 1 is a material roll, 2 is a material fed out from the material roll 1, and 3.
are a pair of cutters for forming corrugate fins that mesh with each other, 4 is a pitch determining device, and 5 is a cutter, and the material 2 fed from the material roll 1 is sent between a pair of cutters 3 for forming corrugate fins that mesh with each other. It is then sent to a pitch determining device 4, where the R part (13 in Fig. 10) of the corrugated fin is formed, and then sent to a cutter 5, where it is cut into a predetermined length. cut into
Becomes a corrugated fin. FIG. 7 shows the same full gate fin, and in FIG. 7, 6 is a wave-shaped plate-like part, and 7 is a group of louvers (wings) formed by cutting the same wave-like plate-like part 6. Moreover, FIG. 8 shows the cutter 3 for forming a full gate fin, and FIG. B) shows a portion of the corrugate fin forming cutter 3 that forms the looper 7, and in FIG. 9(B), 8 indicates a blade portion that shears the louver 7;
9 is the tooth tip and 10 is the tooth bottom.

<Problems to be Solved by the Invention> In order to improve the thermal efficiency of corrugated fins, it is necessary to suppress variations in the height of the corrugated fins within a range of ±0.005 mm. When a corrugated fin is formed using the full gate fin forming cutters 3 and 3 shown in Fig. 6.8.9, the material 2 fed out from the material opening 1 is covered with other parts as shown in Fig. 10. Also, the elongated fold 11 with large curvature and the partial fold 12 are aligned in the rotation direction (A
), and then, when sent to the pitch determining device 4, the R portion 13 of the corrugated fin is formed starting from the crease 11° 12, so the corrugated fin R
The shape of the portion 13 becomes irregular in the width direction, and the height of the corrugated fin varies within a range of ±0.1 to 0.2 cm, making it impossible to improve the thermal efficiency of the corrugated fin. This point will be explained more specifically. Among the above-mentioned folds, the fold 11 on the rear side in the direction of rotation (person) is the first fold at the beginning of forming the material 2 with the corrugate fin forming cutters 3
As shown in Figures 1 and 12, it has been found that the material 2 is sandwiched between the cutter tooth tip 9 and the tooth end @14 on the tooth bottom side corresponding to the cutter tooth tip 9, resulting in creases 11. . On the other hand, the fold line 12 on the front side in the direction of rotation (person) is 13.14.
．． Looper 7 cut into material 2 as shown in Figure 15
The opening direction of the corrugated fins is different for each adjacent louver 7, and therefore the shapes of the left and right portions 15°15 that do not form the looper 7 and the center portion 16 that does not form the looper 7 are also different. Among the parts that do not form a looper, the parts 15 are weak in strength despite receiving the same moment M during bending.
．． It has been found that buckling occurs locally in 15, the curvature increases, and creases 12 occur. As a result, the left and right portions 15. which do not form the looper 7. Is and the center portion 16 where the looper 7 is not formed, the shape of the R portion 13 of the full gate fin is irregular in the width direction, and the height of the corrugated fin is Δh (±01 to
There was a problem that the thermal efficiency of the corrugated fins could not be improved because the thermal efficiency of the corrugated fins varied within the range of

In addition, in order to solve the above problem, if the blade part 8 on the front side in the rotational direction is raised to the maximum outer diameter of the cutter and molded with a cutter with a height difference from the blade part 8 on the rear side, the fin height will be reduced. Although the variation was resolved, the long looper cut increased the twisting of the looper as shown in Fig. 5, resulting in the problem that the way the looper was raised was greatly different between the top and bottom, and the strength against buckling was reduced.

Furthermore, if the blade part 8 is symmetrical with respect to the cutter tooth tip 9 as shown in FIGS. There were variations in the size.

Therefore, the object of the present invention is to suppress the variation in the height of corrugated fins within the range of ±004■,
The object of the present invention is to provide an improved cutter for forming corrugated fins, which can reduce the twisting of the looper 7 shown in FIG. 10, improve the rise of the looper, and improve the thermal efficiency of the corrugated fins.

KuH! ! Means for Solving the Problem> The configuration of the present invention to achieve the above object is such that, in a pair of full-gate fin forming cutters that mesh with each other, a looper shearing blade portion is formed on the front side in the rotational direction with the tooth tips as a boundary. It is characterized by extending to the maximum outer diameter of the cutter, and having a low step part and a notch recessed part on the outer end side of this blade part.

<Operation> According to the above configuration, when the material fed out from the material roll passes between the cutters, a 9th crease is made near the center of the R portion of the corrugated fin, and the material is sent to the pitch determining device, where it is corrugated. The R portion of the fin is preferentially bent from the above crease to form the R portion.

At this time, the provision of the low step portion reduces the number of notches in the louver, increasing the strength against buckling and preventing creases from occurring on the front side in the direction of rotation, and the provision of the notch recess eliminates twisting of the louver. The louvers will no longer move up or down.

As a result, there is no difference in the fin radius shape between the left and right portions where no louvers are formed and the center portion, and there is no variation in the height of the corrugated fins.

Embodiment> An embodiment of the present invention will be described below based on the accompanying drawings.

As shown in Figures 1 and 2, the outer end of the corrugated fin forming cutter 3 is extended toward the front side in the rotational direction from the tip 9 of the cutter 3 to the tip circle (i.e., the maximum outer diameter of the cutter). In this way, the blade portion 8a is formed. On the other hand, on the rear side in the rotational direction A, a blade part 8b is formed with its outer end lower than the outer end of the blade part 8a. This blade portion 8b is formed so as not to interfere with the blade portion of the other cutter that engages with the cutter 3 on the front side in the rotational direction. In addition, 10 in FIG. 2 is a tooth bottom part.

The blade portion 8a on the side of the rotational direction Afi is provided with a low step portion 17 having a step l and a notch recess 18 located at the outer end portion.

Regarding the position of the low step portion 17 and the step 1, as shown in FIG. 3, in order to suppress the variation Δh in the fin height to within ±0.05, the blade on the rear side in the rotation direction A in FIG. The corner portion 20 of the portion 8b, the maximum outer diameter portion on the front side is 21, the blade portion 8b
Assuming that the virtual symmetrical corner of is 22, the value of the ratio of r]-Ding Go to the sum of straight line r]-Y Go and rDing■R is 058 to 07.
It can be seen that a range of 8 is sufficient. Therefore, when the blade portion 8a is provided up to the maximum outer diameter portion 21 on the front side in the rotational direction, the difference in level of the low step portion 17! is 1/3 to 175 times the value of the fin material 2. The position and depth of the notch recess 18 is set at a position that is twice the height HXI of the angle 20 of the rear blade portion 8b, as shown in FIG.

With this configuration, the variation Δh in fin height is stably within ±003, the twisting phenomenon of the louver 7 is eliminated, and there is no difference in the way the louver 7 rises between the upper and lower sides, improving the thermal efficiency of the fin.

<Effects of the Invention> As described above, according to the present invention, a low step portion is provided in the blade portion up to the maximum outer diameter portion on the front side in the rotational direction, and a notch recess is provided at a position slightly lower than the maximum outer diameter portion. When the material fed out from the material roll passes through the cutter, a crease is created near the center of the R part of the corrugated fin and sent to the pitch determining device, where the R part of the corrugated fin is preferentially cut from the crease. Since the R part is formed by bending the full gate fin, the variation in height of the full gate fin can be suppressed within the range of ±005-, and the louver does not twist.
It is also possible to prevent the problem of the louvers rising differently on the upper and lower sides, and improve the thermal efficiency of the corrugated fins.

[Brief explanation of drawings]

Fig. 1 is a side view of the cutter tooth tip according to the first embodiment of the present invention, Fig. 2 is a side view of the main part of the cutter, and Fig. 3 is the position of the low step and the fin height. Fig. 4 is a perspective view showing the variation in the height of the corrugated fins, Fig. 5 is an explanatory drawing showing the problem of how the louvers of the corrugated fins rise, and Fig. 6 is a diagram showing the relationship between the variations in the height of the corrugated fins. , FIG. 7 is a side view showing a conventional corrugated fin manufacturing device (and FIG. 8 is a perspective view showing a full gate fin manufactured by the same manufacturing device, and FIG. 8 is a side view showing a conventional corrugated fin forming cutter, FIG. 9 (A), (B) i!, each side view showing an enlarged part of the cutter for forming corrugated fins,
FIG. 10 is a perspective view showing the creases that occur in the corrugated fin, FIGS.
FIG. 5 is an explanatory diagram showing the causes of creases on the front side in the rotational direction of the cutter, and FIG. 16 is an explanatory diagram showing variations in the height of the corrugated fins. In addition, in the drawing, 1 is a material roll, 2 is a material (fin material), 3 is a cutter for forming a full gate fin, 4 is a pitch determining device, 5 is a cutting section, 6 is a corrugated plate-shaped section, and 7 is a louver (blade) , 8.8a and 8b are the blade parts that shear the louver, 9 is the tooth tip, 10 is the tooth bottom, 11 is a long fold with a large curvature, 12 is a partial crease, 13 is the R part of the corrugated fin, 14 is the tooth end on the bottom side of the tooth, 15 is the left and right wavy plate-like parts that do not form a looper, 6 is the central wavy plate-like part that does not form a looper, 7 (low step part), 8: notch It is a recess. Mitsubishi Heavy Industries, Ltd.

Claims (1)

[Claims] In a pair of cutters for forming corrugate fins that mesh with each other, a blade for louver shearing formed on the front side in the rotational direction with the tip of the tooth as a boundary is extended to the maximum outer diameter of the cutter, and a low step part is formed on the outer end of this blade. A cutter for forming corrugate fins, which is characterized by having a notched recess.