JPH0732928B2 - Heat transfer tube manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a heat transfer tube having a grooved inner surface for use in a heat transfer device such as an evaporator or a condenser.

[0002]

2. Description of the Related Art Conventionally, in a heat transfer device involving boiling and condensation, a heat transfer tube having a high heat transfer efficiency and a small pressure loss is generally made of a copper material having a spiral groove on its inner surface.

The inventors of the present invention manufacture a heat transfer tube in which a metal strip having a grooved portion left on both side ends is formed into a tubular shape with the grooved surface inside and then the abutting portions are welded. A method was developed and proposed (JP-A-1-108411). However, when the groove to be formed has an inclination angle with respect to the traveling direction of the metal strip, the widthwise strip is formed at the stage where the metal strip 1 passes through the grooving roll 2 as shown in FIG. There is a problem that a shift (direction of arrow) occurs.

As a means for preventing such a plate displacement phenomenon, a method of forming left and right symmetrical inclined grooves on a metal strip plate surface is applied. That is, in this method, as shown in FIG. 6, a pattern in which a groove is symmetrical to the left and right through two grooved rolls 2 and 3 having different inclination directions on one surface of the metal strip 1 that is continuously fed. After forming the slanted groove 4 of No. 1 and then cutting it with the slitter 5 and bending it with the forming rolls 6 in multiple stages, the welded portion is welded with the welder 7 and finally drawn by the drawing machine 8. And the step of obtaining the heat transfer tube 9 with the inner surface groove.

[0005]

However, when the above-mentioned process is adopted, it is effective for preventing the plate misalignment, but the inner groove having the right inclination and the left inclination is formed at the same time. Therefore, there is a problem in that a product having a standardized inclined inner surface groove cannot be produced. In addition, since chips are generated by the slitter, there is a problem that the material yield is deteriorated.

The present invention was developed in order to solve the above-mentioned problems, and its purpose is to provide an effect of the displacement (plate shift phenomenon) of a metal strip that occurs when a grooved roll having a unidirectionally inclined groove is used. It is an object of the present invention to provide a method of manufacturing a heat transfer tube having a slanted inner surface groove which is constantly corrected and always shaped.

[0007]

In order to achieve the above object, a method of manufacturing a heat transfer tube according to the present invention comprises a grooved roll having a unidirectional slant groove engraved while feeding a metal strip. In the method of forming a tubular body by grooving, then butt-welding both edges to obtain a heat transfer tube with internal groove, when the metal strip passes through the grooving roll during grooving Depending on the deviation in the width direction that occurs on the metal strip,
By adjusting the degree of processing at both ends of the metal strip,
The structural feature is that the deviation in the width direction is corrected and the metal strip is fed straight.

Copper or aluminum is effectively used as the material of the metal strip in terms of workability and heat transfer. As shown in FIG. 1, the grooving process is performed between the grooving roll 2 in which the metal strip 1 continuously fed from the raw material coil 10 is engraved with a unidirectional slant groove and the lower roll 11 having a smooth surface. Is carried out by the process of passing through.

The main requirement of the present invention resides in a process portion for adjusting the working degree of both side portions of the metal strip in accordance with the deviation of the metal strip in the width direction during the grooving process. As shown in the roll front view of FIG. 2, a specific process for adjusting the working degree is performed by inclining the contact surface of the grooved roll 2 with respect to the metal strip 1 by the arrow method, and This can be done by changing the degree of reduction of. At this time, in correcting the displacement phenomenon in which the metal strip 1 is displaced to the right with respect to the traveling axis during the groove forming, the grooved roll 2 is tilted in the direction of the solid line arrow, while the displacement to the left is caused. In contrast, the grooved roll 2 is inclined and corrected in the direction of the broken line arrow.

Another mode for adjusting the degree of processing is shown in FIG.
As shown in FIG. 5, a pressure roll 12 having a mechanism in which the contact surface is inclined with respect to the metal strip 1 is provided in the preceding stage of the grooved roll 2, and the tension on both sides of the metal strip is changed by the inclined contact. There is a process. In this case, as shown in the roll front view of FIG. 4, the contact surface of the pressure roll 12 with respect to the metal strip 1 is inclined in the direction of the solid line arrow so that the metal strip 1 shifts to the right. The position is corrected, and conversely, by giving the contact inclination in the direction of the broken line arrow, it becomes possible to correct the plate displacement deviation to the left.

In the above embodiment, as shown in FIGS. 1 and 3, the deviation detector 13 of the metal strip 1 is installed at the rear stage position of the grooved roll 2 and the signal from the deviation detector 13 is detected. Grooving roll 2 or pressure roll for metal strips based on
It is preferable to add a mechanism for adjusting the inclination of 12.

The step of forming the tubular body is carried out by a method in which the metal strip after groove processing is bent by the forming roll 6 with the processed surface inside. Then, the abutting portions of both end edges are welded using a welder 7 such as TIG welding, MIG welding, electron beam welding, and high frequency welding. The tubular body after welding is
Finally, a drawing machine 8 is used for drawing to obtain a heat transfer tube 9 having an inner grooved structure with a constant inclination pattern.

[0013]

According to the present invention, the grooving roll having the unidirectional inclined groove is used by adjusting the working degree of both side portions of the metal strip in accordance with the deviation of the metal strip in the width direction during the grooving. It is possible to effectively correct the plate misalignment phenomenon that occurs at that time. In the rolling process, this straightening mechanism normally uses the strip speed V _S on the roll exit side and the roll peripheral speed V _R to calculate f.
= (V _S −V _R ) / V _R based on the advance rate f obtained by the relationship, the advance rate f is substantially changed by changing the rolling reduction or the tension on both sides of the metal strip. The effect of correcting the plate misalignment is brought about.

Through such an action, it is possible to always prevent the metal strip plate from being displaced during the grooving process.

[0015]

Example 1 A metal strip made of phosphorus deoxidized copper having a width of 31 mm and a thickness of 0.6 mm is placed on the apparatus shown in FIG. 1, and a groove having a diameter of 100 mm and a width of 40 mm and having an inclination angle of 17 ° with respect to the running direction of a strip. Grooving was performed under a load of 5 tons using a grooved roll with a depth of 0.20 mm and 50 threads (5 mm on each side was a smooth part). When the grooving roll is held horizontally and processed, the groove on the roll surface shifts 8 mm when moving 26 mm to the feed side, but the plate deviation is smaller than this and 0.8 mm to the right of the running direction. Caused plate misalignment.
However, when grooving was performed while giving a slope (in the direction of the solid line arrow in FIG. 2) to the contact surface of the grooved roll to increase the rolling reduction on the right side of the metal strip, the plate displacement deviation was corrected. Straight running was confirmed.

Example 2 The same metal strip as in Example 1 was used to manufacture a heat transfer tube using the apparatus shown in FIG. A grooved roll having the same shape as that of Example 1 was used, and a grooved groove was formed by interposing a pressure roll having a slope (indicated by the solid arrow in FIG. 4) on the contact surface of the preceding stage. . In this example, the tension on the left side of the metal strip was increased to correct the plate misalignment, and it was confirmed that there was straight line running without deviation in the width direction.

[0017]

As described above, according to the present invention, it is possible to always smoothly manufacture the heat transfer tube having the inner surface inclined groove in the same direction without causing the plate displacement deviation during the groove forming. Moreover, since no chips are produced by the slitter as in the conventional plate misalignment prevention technique shown in FIG. 6, the material yield is not reduced.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view illustrating an apparatus for manufacturing a heat transfer tube used in the present invention.

FIG. 2 is a front explanatory view showing a grooved roll portion in FIG.

FIG. 3 is a schematic cross-sectional view illustrating an apparatus for manufacturing a heat transfer tube used in the present invention.

FIG. 4 is a front explanatory view showing a pressure roll portion in FIG.

FIG. 5 is an explanatory plan view showing a plate shift state at the time of grooving processing when using a unidirectionally inclined grooving roll.

FIG. 6 is a perspective view showing a heat transfer tube manufacturing apparatus with a conventional mechanism for the purpose of preventing plate misalignment.

[Explanation of symbols]

 1 Metal Strip 2 Grooving Roll 3 Grooving Roll 4 Inclined Groove 5 Slitter 6 Forming Roll 7 Welding Machine 8 Drawing Machine 9 Heat Transfer Tube 10 Raw Material Coil 11 Lower Roll 12 Pressure Roll 13 Deviation Detector

Claims (4)

[Claims] 1. A grooved roll is formed on one surface of a metal strip plate while feeding a metal strip through a grooved roll having a unidirectional slanted groove.
In the method of forming a tubular body and then butt-welding both edges to obtain a heat transfer tube with internal groove, in the width direction that occurs in the metal strip at the stage when the metal strip passes through the grooving roll during grooving The degree of processing at both end portions of the metal strip plate is adjusted according to the deviation of the metal strip plate to correct the shift in the width direction and the metal strip plate is fed straight. Method of manufacturing heat tube. 2. The degree of working is controlled by changing the degree of reduction of both side portions of the metal strip so that the contact surface of the grooved roll with respect to the metal strip is inclined. Method for manufacturing heat transfer tube. 3. The degree of working is controlled by installing a pressure roll whose contact surface is inclined with respect to the metal strip in front of the grooved roll and changing tensions on both sides of the metal strip. Item 1. A method for manufacturing a heat transfer tube according to item 1. 4. A deviation detector for the metal strip is installed at a position subsequent to the grooved roll, and the inclination of the grooved roll or the pressure roll with respect to the metal strip is determined based on a signal from the deviation detector. The method for manufacturing a heat transfer tube according to claim 2, wherein the heat transfer tube is adjusted.