JPS6115771B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing finch tubes.

Conventionally, the manufacturing process for finch tubes can be roughly divided into the following two steps.

(1) Forming the fine coil, (2) Grooving the tube and inserting and caulking the fine coil.

Therefore, as shown in FIGS. 1 and 2, the fin coil 2 is formed by rolling a strip plate 1, which is a material for fins, and changing the amount of reduction in the width direction and changing the amount of elongation in the longitudinal direction.

That is, the fin material strip 1, which has a rectangular cross-section in the section A-A' in FIG. 2, is rolled while being sandwiched between a rolling pan 3 and a spindle roll 4, as shown in FIG. At this time, the rolling surface 3a of the rolling pan 3 for rolling the strip is inclined so that the upper part is narrower. In addition, the arrow view of the rolling pan 3 and spindle roll 4 in FIG. 1 from the X direction is shown by 4th 3 and 4. That is, as understood from FIGS. 1 and 4, the rolling surface 3a of the rolling pan 3 has a truncated conical shape.

Therefore, the fin material strip 1 rolled by the rolling pan 3 and spindle roll 4 shown in FIG.
As shown in the B-B' cross section in Figure 2, the B' end is B
It is rolled to be thinner than the edges, so
The amount of stretching increases, and a circular fin material with B' as the outer peripheral surface and B as the inner peripheral surface is formed as shown in the figure. The situation in which circular fins are formed is shown in fin 2 in FIG.

A tube with an outer diameter slightly smaller than the inner circumferential surface is fed into the inner circumferential surface from the right side of Fig. 4 so as to be in contact with the inner circumferential surface of the circular fin 2 in Fig. 4, and the fin is wound around this tube. Put it on. When wrapping a fin around a tube, the tube is rotated and sent from the right to the left.
At this time, as shown in FIG. 3, the groove tool 6 is pressed against the tube 5 to form a groove 7.
It is wrapped while rotating. In order to securely fix the fin to the tube, the outer peripheral surface of the tube near the groove 7 after wrapping is pressed with a caulking tool to caulk the fin into the groove. This situation will be explained with reference to FIG. That is, grooving and caulking are performed by pressing a grooving tool 6 against the outside of the tube 5 to form a groove 7, as shown in FIG. 3, and inserting the fine coil 2 formed in the above process into this groove 7. The fine coil 2 is caulked and fixed to the tube 5 from the outside of the groove 7 by the subsequent caulking tools 8, 8.

In order to understand the winding and caulking of the fins around the tube described in FIGS. 3 and 4, FIG. 7 shows a schematic plan view of the fin wrapping device. The fin material strip 1 is wound on a reel 21. The tube 5 is connected to the screw 18 by a connector 19. The screw 18 is fitted with a nut 20.

A motor (not shown) rotates the rolling pan 3 to the right and the spindle roll 4 to the left, and rolls the fin material strip 1 such that the rolling reduction becomes larger toward the lower side, thereby forming the fin coil 2. At this time, if the screw 18 is rotated clockwise by the motor, the tube 5 moves to the left while rotating clockwise.

A spiral groove 7 is created on the surface of the tube 5 by the grooving tool 6, and the fin coil 2 is inserted into this groove 7.
The inner circumferential side of the fin coil 2 is fitted, and the fin coil 2 is crimped from both sides of the groove 7 using the crimping tool 8.
is fixed to tube 5.

However, when rolling, bending, grooving, and caulking are performed continuously, the fin coil often collapses or is caulked on the outer surface of the tube to form so-called loose fins after the caulking process, which poses a problem.

The cause of these troubles is thought to be mainly due to the difference between the outer diameter of the tube and the inner diameter of the fine coil immediately after rolling and bending. That is, if the inner diameter of the fin coil is smaller than the outer diameter of the tube, the fins will collapse, and if it is too large, loose fins will occur.

In order to absorb the difference between the outer diameter of the tube and the inner diameter of the fin coil immediately after rolling and bending, the inner diameter of the fin coil immediately after rolling and bending is made slightly larger than the outer diameter of the tube, so that tension is applied to the fin coil when it is wound around the outside diameter of the tube. Although the rotational speed of the tube and the rolling and bending speed of the fin coil are adjusted, it has been difficult to completely eliminate the occurrence of fin collapse and loose fins.

The inner diameter of the fin coil set during the preparatory work changes when the rotational speed of the rolling pan and spindle roll during operation, that is, the rolling bending speed (expressed by the motor rotation speed in the present invention) changes from the rolling bending speed set during the preparatory work. The inner diameter changes. If the rolling bending speed is slow, the inner diameter of the fin coil becomes large, and the fin becomes loose because it cannot be caulked to the tube. Furthermore, as the rolling and bending speed increases, the inner diameter of the fin coil becomes smaller, causing the fin to fall down when being wound around the tube. especially,
The fins tend to loosen when the motor starts and stops.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a method for manufacturing a finch tube that does not cause fin collapse or loose fins.

In short, the present invention is characterized in that tension is applied to the fin material before rolling and bending, and the tension is controlled to stabilize the diameter of the fin coil during rolling and bending.

The present invention will be explained based on embodiments and with reference to the drawings. In FIGS. 3, 4, and 7, a strip 1 of material for fins is rolled and bent using a rolling pan 3 and a spindle roll 4 to form a fin coil 2, and a tube 5 processed using a grooving tool 6. into groove 7.

Immediately thereafter, the outside of the groove is caulked from both sides of the groove using caulking tools 8, and the fin coil 2 is fixed to the tube 5.

Here, 9 is a tension load control mechanism for the strip plate 1, which applies a required tension to the fin material.

With such a configuration, the strip 1, which is the material for the fins, is rolled into a fin coil by rolling and bending between the rolling pan 3 and the spindle roll 4 while being loaded with the required tension through the tension load control mechanism 9. 2, and by controlling the tension, a coil with a stable diameter can be formed.

Now, the reason why it is possible to stabilize the inner diameter of the fin coil through tension control and prevent loose fins or collapse of the fins will be explained.

FIG. 5 is a diagram showing the relationship between rolling bending speed n (rpm) on the horizontal axis and inner diameter d (mm) of the fine coil on the vertical axis.

As the machining speed increases, the fin inner diameter decreases. In other words, if the outer diameter of the tube and the inner diameter of the fin coil are matched at low speeds, the fins tend to fall down when operating at high speeds, and when the outer diameter of the tube and the inner diameter of the fin coil are matched at high speeds and then operated at low speeds, loose fins are likely to occur. Become.

FIG. 6 is a diagram showing the relationship between the tension T (Kg) of the fin material at the entrance of rolling bending on the horizontal axis and the inner diameter d (mm) of the fin coil on the vertical axis.

As is clear from the figure, the larger the applied tension, the smaller the inner diameter of the formed fine coil.

The present invention takes advantage of these relationships.
In other words, the tension is controlled by the tension load control mechanism 9 so that the tension is large during low-speed rotation when the device is started, and is small during high-speed rotation. The load control mechanism 9 is located between the reel 21 and the rolling pan 3 and spindle roll 4, and applies tension to the fin material strip 1 between the tension load control mechanism 9 and the rolling pan 3 and spindle roll 4. The method for manufacturing a finch tube according to the present invention makes it possible to manufacture a stable finch tube without collapsing the fins or causing loose fins, not only during steady operation but also when the motor is started or stopped. There are some things that are very effective.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing a conventional method for manufacturing a fin coil, Figure 2 is a schematic diagram of fin coil forming, Figure 3 is a schematic diagram of a fin coil manufacturing method, and Figure 4 is a schematic diagram of a fin coil manufacturing method.
7 is a plan view of an embodiment of the present invention, and FIG.
6 are diagrams showing experiments that are the basis of the present invention. 1... Material strip plate for fins, 2... Fin coil, 3... Rolling pan, 4... Spindle roll, 5... Tube, 6... Grooving tool, 7...
... Groove, 8 ... Caulking tool, 9 ... Tension load control mechanism, 18 ... Screw, 19 ... Connector, 20 ...
Nut, 21... Reel, d... Fin coil inner diameter, n... Rolling bending speed, T... Load tension.

Claims (1)

[Claims] 1. When forming a fin coil by rolling and bending a fin material, tension is applied to the fin at the entrance of the rolling and bending process, and when the rolling and bending speed of the fin is low, the tension is increased, and when the rolling and bending speed is high, the tension is applied. A method for manufacturing a fin fin that obtains a stable coil fin by controlling the tension to a small value.