JPS60234724A - Forming method of corrugated fin and its forming device - Google Patents

Abstract

PURPOSE:To elevate a dimensional accuracy by allowing the thread part of a fin to progress along a spiral groove of which pitches are lessened in order after the formation of a corrugated fin having the prescribed shape. CONSTITUTION:An extremely thin copper material is passed through between forming rollers under the prescribed tension to perform a corrugation bending and a louver working at the 1st stage. This formed fin 1 is guided by a pair of feeding rollers 4, 4 and fed to a pair of worm gears 7, 7'. The shape of lead grooves 7a, 7a' of the worm gears 7, 7' is made as a trapezoidal recessed groove and the depth of grooves is deepened toward outlet side from inlet side and the grooves width is narrowed as well. Consequently the tip of the thread part of the fin 1 progresses along the lead grooves 7a, 7a' and is bent and the fin pitch is lessened. The fin 1 formed with this method has no deformation, etc. of the louver part and the dimensional accuracy is improved.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for forming wavy fins used in heat exchangers, etc., and a forming apparatus therefor. It is effective when used.

(Prior art) Conventional wavy fin forming involves passing an ultra-thin copper layer, etc., continuously between a pair of float-shaped forming rolls called corrugated gears while applying a certain tension, and then bending the material into a wavy shape. Forming and recessing to cut the louvers are done at the same time.
It is molded into a predetermined fin shape. Thereafter, it is sent to a pinching device by a fin feed roller. The pinching device compresses the fins to a constant fin pitch, and the cutting device in the final step cuts the fins into a predetermined number of fins. This pinching device compresses the fins by utilizing the frictional force generated when the fins pass through two parallel guides. That is, a guide is pressed against the crest of a flowing fin formed into a predetermined fin shape, and the fin pitch is reduced by the resistance generated by the braking force. As a result, the following problems have arisen.

First of all, since the guide is pressed against the peaks of the wavy fins to compress the fins, the shape of the peaks of the fins is not good. That is, the ridge portions do not have a predetermined rounded shape and are deformed, and at the same time, the lengths of the wavy fins after being cut vary. In addition, since the force with which the guide is pressed is set constant by means such as a spring, when the speed of the fins flowing through the pitch determining device changes,
At the same time that the fin pinch is not constant, the length of the wavy fins after cutting varies. For this reason, there was a problem in that the speed at which the fins flow, that is, the speed at which the fins are formed, cannot be made high, and the speed cannot be changed.

Secondly, since the wavy fins are fed to the pitching device by the rotation of the fin feed roller, the louvers of the wavy fins are directly pressed by the teeth provided on the roller. For this reason, there is a problem that the angle at which the louver is placed becomes small and the louver is damaged. Further, the wavy fins compressed by the pinching device are compressed to the extent that adjacent louvers touch, taking into account the spring bank after molding. Therefore, there is a problem in that the louvers come into contact with each other, further reducing the angle of the louvers. When the wavy fins having louvers as described above are used as corrugated fins of a heat exchanger, a problem arises in that the heat exchange efficiency decreases.

(Object of the Invention) The present invention has been made in view of the above-mentioned points, and its object is to provide a wavy fin in which the fin pitch and notch after molding are equal and the shape of the ridge portion of the wavy fin is good. This provides a molding method.

A further object of the present invention is to provide a wavy fin forming apparatus that can easily carry out the above-described forming method.

(Example) Next, an example of the present invention will be described. First, as shown in FIG. 1(a), as shown in FIG. 1(a), a pair of gear-shaped forming rollers 3
During this time, the sheet is passed continuously, and then the wavy bending and shearing process to cut the louver 2 are carried out simultaneously.
It is the same as the conventional one. In this step, the wavy fins formed into a predetermined fin groove and a predetermined fin shape flow to a second step described below. In addition, FIG. 1 (bl is a perspective view of a predetermined wavy fin after the first step,
Figure (C1 is a sectional view taken along the line A-A' in Figure 1 (bl), and α is the angle of the louver 2.

Next, the second step will be explained based on FIGS. 2 to 10.

The second step is a step in which the predetermined wavy fins formed in the first step are further compressed, that is, the fin notches are made smaller and at the same time, each fin notch is made equal.

FIG. 2 is a schematic diagram of the apparatus used in the second step. Reference numeral 1 in the figure indicates a predetermined wavy fin formed in the first step. This fin 1 is connected to a pair of feed rollers 4, 4'
is guided by a worm gear 1 having a pair of parallel shafts.
Sent to 00.

Then, the worm gear 100 reduces the fin pitch. Thereafter, it is cut according to the peaks defined by a cutting device (not shown), and is placed on a belt 6 moving in the direction of arrow a by the rotation of the belt pulley 5 and carried out.

Furthermore, the worm gear 100 will be explained in detail based on FIG. 3. In the figure, 7.7' indicates a pair of worm gears. The pair of worm gears 7, 7' are arranged above and below the fin 1, and their rotational axes are arranged parallel to the direction in which the fins travel. This worm gear 7.7
' is 20.20' with bearings on both ends of the top and bottom.
It is rotatably supported. A toothed belt wheel 8.8' is fixed to one end of the worm gear 7.7', and is tightened to a shaft 10°10' which rotates by the drive of a toothed heald 9.9'. and rotate.

Note that the feed roller 4.4' and the worm gear 7.7' are mechanically connected, and the movement of one tooth of the feed roller 4 causes the worm gear 7.7' to rotate once.

Each worm gear 7.7' has a spiral lead groove on its outer circumference? a and 7a' are machined, and the tips of the ridges of the fin 1 are restrained in these grooves one by one. Also, the arrangement of the fin 1 and the worm gear 7.7' is as shown in Fig. 4.
Of the peaks of the fins, only the uncut end portions of the louvers 2, that is, the R-shaped portions, are restrained by the lead grooves 7a, 7a'', and the bottoms of the lead grooves 7a, 7a' are located above and below the fins 1. It also serves as a direction guide. In the figure, reference numeral 11 denotes a guide plate, which is a die that prevents the fin 1 from shifting in the left-right direction. Combine the two lines,
The exit side of the fin 1 is processed to have a single thread opening. Here, the relationship is shown in FIG. 5, where the negative lead grooves are designated 7b and 7b', respectively. In FIG. 5, the horizontal axis shows the length of the worm gear, and the vertical axis shows the deployment angle. A and B indicate the respective center trajectories of the double lead grooves 7a and 7a', and C indicates the confluence point. The lead groove pitch on the inlet side of the worm gear 7 starts from the same number as the fin pitch of the fins 1 on which the fins 1 are formed and is sent by the feed roller 4,
As the fin 1 advances, the cutting is decreased by 1 per revolution of the worm gear 7.7'. Here, FIG. 7 shows the fin 1 after being molded in the first step, and FIG. 8 shows the fin 1' after being molded in the second step. In the figure, H and H' indicate the height of the fin 1.1', L and H' indicate the width of the tip portion of the bent fin 1.1' where the louver 2 is not cut, and P The pitch of the peaks of fin 1.1' is shown. Further, FIG. 9 shows the relationship between the pitch P and the height H of the fin 1, and FIG. 10 shows the relationship between the pitch P and the width of the tip portion without a louver. That is, the pitch P
When the peaks of the fin 1 are reduced, that is, the peaks of the fin 1 are shortened to form the fin 1', the peak height H of the fin increases, and the width of the tip portion without a louver decreases. In addition, in order to prevent damage to the fin 1 and the louvers 2 provided on the fin 1, the shape of the lead grooves 7a and 7a' of the worm gear 7.7' is a trapezoidal concave groove, and as the fin pitch decreases, the inlet side The groove depth of the lead grooves 7a, 7a'' is deepened toward the exit side, and at the same time, the groove width is narrowed.For this reason, the fin 1 does not damage the louver 2 provided on the fin 1. It can proceed smoothly along the lead grooves 7a, 7a'.

Next, its operation will be explained based on the above configuration.

The second process of forming the fin 1 will be explained with reference to FIG.

The fin 1, which has been formed into a predetermined shape by a pair of forming rollers 3 and 3', is sent in the direction of arrow B by a feed roller 4, and the ridge portion of the fin 1 is placed in the upper lead groove of the worm gear 7.
He sent one mountain at a time to A and returned home. By this rotation of the worm gear 7, the fins 1 are sent one by one while being restrained by one lead groove 7a, and are also bitten into the lead groove 7a of the lower worm gear 7'. Upper and lower worm gear 7°7'
The fin 1 restrained by the lead grooves 7a and 7a' moves leftward in the figure as the worm gear 7.7' rotates. Here, as shown in FIG. 6, the tip of the mountain portion of the fin 1 advances along the lead grooves 7a, 7a',
As the fins are bent, the fin pitch P becomes smaller and the fins are contracted. Furthermore, two lead grooves? In the single lead grooves 7b and 7b' after the merging of the lead grooves a and 7a' (see FIG. 6), two fins 1 are restrained in each lead groove 7b and 7b'. And worm gear 7.7'
As the fins 1 rotate, the pitch P of the fins 1 is further reduced, and on the exit side, the fins are shrunk to a final wave shape. In addition, on the inlet side and outlet side of the worm gear 7.7',
Guide plate 1 that guides the bottom and left and right sides of fin 1゜1'
1 is provided.

In the embodiment described above, the two lead grooves on the entrance side merge into one lead groove from the middle, but the lead groove on the entrance side has a plurality of grooves, that is, 2 to the nth power (n = positive integer). But that's fine. In this case, the lead grooves are merged so that the order (n) is gradually decreased from the middle, and the lead grooves are received near the exit side so as to finally merge into a single lead groove.

For example, a lead groove with four grooves on the entrance side becomes two grooves in the middle, and finally becomes a single lead groove. Here, the outlet side does not necessarily have to be a single strip.

In addition, although the example shows that the pinch of the lead groove of the worm gear is reduced by one revolution of the worm gear, the final fin is The shape can be further improved. When the number of fins is 0, the fin pitch is not reduced, and the shape of the peaks of the fins is simply shaped.

Further, in the above-described embodiment, the shape of the lead groove is a trapezoidal groove, but other shapes may be used as long as the shape does not damage the fins and the louvers of the fins.

For example, there is no problem even if the groove is rounded or triangular.

Moreover, when the width of the grooved fin is wide, a plurality of worm gears similar to those described above are arranged in parallel and molded.

Further, in the above embodiment, the fin feeding roller for the second step was provided separately from the forming roller for the first step, but the forming roller for the first step may be used directly as the fin feeding roller for the second step. At this time, the forming roller is meshing with the worm gear of the second step.

Further, the small spiral groove provided in the worm gear may be a spiral protrusion.

(Effects of the Invention) As described above, the present invention is characterized in that the crests of the wavy fins advance along the spiral grooves provided in a pair of worm gears, thereby shrinking and forming the fins to reduce the fin pinch. It is something to do.

Therefore, the angle of the louver cut into the wavy fin does not become small. That is, the louver will not be deformed or damaged during molding. In addition, the shape of the peaks of the final wavy fin after molding is good, without deformation.
That is, it can be formed into an R shape. At the same time, since each fin pitch can be made equal, variations in the length of the wavy fins after cutting can be suppressed.

Furthermore, by changing the rotation speed of the worm gear,
The molding speed can be easily changed without impairing the accuracy of the final shape after molding and the dimensions after cutting. The present invention exhibits various excellent effects as described above.

[Brief explanation of drawings]

FIG. 1(a) is a schematic diagram showing the first step of the present invention, FIG. 1(0)l is a perspective view showing a fin formed in the first step, and FIG. ), FIG. 2 is a schematic diagram showing the second step of the present invention, FIG. 3 is a perspective vertical cross-sectional view of essential parts showing the apparatus used in the second step of the present invention, and FIG. The figure is a cross-sectional view showing the device used in the second step of the present invention, FIG. 5 is a diagram showing the locus of the lead groove of the worm, and FIG.
7 is a schematic diagram showing the fin after the first step, FIG. 8 is a schematic diagram showing the fin in the second step, and FIG. 9 and FIG. It is a figure provided for explanation of the present invention. ■... Wavy fin after the first step, 1'... Wavy fin after the second step, 2... Louver, 3... Forming roller, 7.7'... Worm gear, 7a, ? a'...Two lead grooves, 7b, 7b'...-lead grooves, 1
00...Pair of worms, P...Fin pitch. Representative Patent Attorney Takashi Okabe Figure 1 (a) (b) (C) Figure 4 Figure 5 Figure 7 Figure 9 Figure 1111111 Sea Figure 8 Figure 10-111 1111ra-

Claims (4)

[Claims] (1) A first step of forming a plate material into wavy fins having a predetermined fin pitch and louvers, and forming the crests of the fins into spiral grooves that are created so that the groove pinch becomes progressively smaller. a second step of making the fin pitch smaller than the predetermined fin pitch by advancing along the wavy fin. (2) a pair of meshing forming rollers for forming a wavy fin having a predetermined fin pinch and louver from a sheet metal; and a worm gear provided with a spiral groove and in which the groove pinch of the groove becomes gradually smaller; The fin pinch of the wavy fin is formed to be smaller than the predetermined fin pitch by causing the peak portion of the wavy fin formed by the forming roller to advance along the groove as the worm gear rotates. A wavy fin forming device featuring: (3) The wavy fin forming apparatus according to claim 2, wherein the groove has a narrower groove width and a deeper groove depth as the groove pinch becomes smaller. (4) The wavy fin forming device according to claim 2 or 3, wherein the grooves are a plurality of grooves at one end of the worm gear, merge in the middle, and form a single groove at the other end.