JPH0787942B2 - Heat transfer tube manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a heat transfer tube, and particularly to a heat transfer tube used for a refrigerator or a heating / cooling device having a mesh layer on an inner surface or an outer surface. The present invention relates to a manufacturing method.

"Prior Art" For example, Japanese Patent Application Laid-Open No. 55-116098 discloses a technique of fixing a wire mesh to the inner wall surface of the pipe as one means for forming a porous layer on the inner wall surface of the pipe.

"Problems to be solved by the invention" Recently, especially for air conditioning equipment, a pipe with a small diameter such as 10 mm or less and a thin wall (0.3 mm or less) is used due to high performance, miniaturization, and weight reduction. However, as in the manufacturing method described in the above publication, it is difficult to manufacture a heat transfer tube having a small diameter or a thin heat transfer tube by means of fixing a wire mesh or other mesh to the inner wall surface of the tube, There is a drawback that it takes time and effort to fix the mesh to the inner wall surface of the pipe and the manufacturing cost increases.

Further, as a general method for producing a heat transfer tube, there is a means of forming unevenness of a constant shape on one surface of a metal strip by a working roll, rolling the strip in the width direction, and welding both edges thereof. According to this method, when the strip plate is made of a hard material such as a copper alloy or an iron-based metal, it is extremely difficult to form the unevenness.

It is an object of the present invention to provide a method for manufacturing a heat transfer tube, in which such drawbacks are improved.

"Means for Solving Problems" In order to achieve the above-mentioned object, the method of the present invention comprises a step of fixing a mesh or a porous sheet with a melted low melting point alloy on one surface or both surfaces of a metal strip, Rolling the strip in the width direction and welding both edges of the strip.

The low melting point alloy is interposed on the entire surface between the surface of the metal strip and the mesh or the porous sheet as long as the mesh or the porous sheet can maintain the state of being fixed to the metal strip. Alternatively, or by interposing it in a part thereof.

"Function" The mesh or porous sheet fixed to the surface of the metal strip plate forms irregularities corresponding to the mesh or porous shape on the inner surface or the outer surface of the heat transfer tube, and promotes boiling and condensation of the medium liquid.

[Embodiment] A preferred embodiment of the present invention will be described below with reference to the drawings.

The uncoilers 10, 20 and 30 are installed in a state where their respective rotation axes are parallel to each other, and the payout rolls 4 and 4 are used to move the uncoiler 10 to a copper metal strip 1 having a thickness of 0.2 mm and a width of 33 mm, and the uncoiler 20 to a width. From the uncoiler 30, the wire diameter of several low melting point alloys 2 consisting of solder of about 5 to 2 mm at regular intervals
A metal mesh 3 made of zinc-plated steel wire of 0.19 mm, the same width as the strip plate and having a rhombic mesh of about 40 mesh is fed out from below at a constant speed in a state of being stacked in the above order.

The low-melting-point alloy 2 is preferably fed into a state in which narrow ones are evenly arranged within the width of the metal strip 1 as shown in FIGS. The low melting point alloy 2 at the edge is narrower than that at other positions.

While the low melting point alloy 2 is partially sandwiched between the metal strip 1 and the mesh 3, the metal strip 1 and the mesh 3 are pushed forward by the pressure rolls 5 and 5 at the forward position in the feeding direction.
Are temporarily fixed to each other through the low melting point alloy 2 by pressure bonding to form a composite sheet 1 ', and then the composite sheet 1'is formed by the alloy 2
Furnace 6 at a temperature above the melting point of (290-300 ° C in this example)
The low melting point alloy 2 is passed through the inside to melt the low melting point alloy 2 to fix the mesh 3 on the upper surface of the metal strip 1 in the composite sheet 1 '.

After the above-mentioned steps are finished, the composite sheet 1'is unrolled.
Are sequentially rolled in the width direction by various forming roll groups 70 to 77, and the both edges of the tubular composite sheet 1'which is passed through the welding induction coil and rolled into a tubular shape are welded to manufacture the heat transfer tube 11.

Finally, the heat transfer tube 11 is formed into a heat transfer tube having an outer diameter of 9.53 mm and a substantially circular cross section by using appropriate shaping rolls 78 and 79 or by guiding to a die (not shown) and cold drawing.

By the above manufacturing method, as shown in FIG. 3, a heat transfer tube 11 having a diamond-shaped fine irregularity 12 on the inner peripheral wall surface and having excellent heat transfer properties for promoting boiling and condensation of a medium liquid such as Freon is manufactured. be able to. Further, according to the manufacturing method of the above-mentioned embodiment, as compared with the conventional method of gluing the mesh on the inner wall surface of the tube, it is possible to mass-produce the heat transfer tube having a thinner wall and a smaller diameter at low cost, and the iron-based alloy and other solid materials. Even when the heat transfer tube is manufactured by, the irregularities can be formed extremely easily.

In the method of the present invention, the shape of the mesh is not particularly limited. Further, instead of the mesh 3, a porous sheet in which fine holes are densely formed can be used, and the low melting point alloy 2
Instead of partially interposing between the metal strip 1 and the mesh 3 or the perforated sheet, a low melting point alloy 2 having the same width as the strip 1 is used, and the entire surface between the both 1 and 2 is used. Low melting point alloy 2
It is also possible to implement even if it is configured to intervene.

Further, the mesh 3 and the like can be fixed on both surfaces of the metal strip 1, and in order to fix the mesh 3 and the like on the surface of the metal strip 1, instead of using the low melting point alloy as described above, The mesh 3 or the like can be fixed to the strip 1 by spot welding.

Further, the means for rolling the metal strip 1 on which the mesh 3 or the like is fixed is not limited to the configuration of the above-described embodiment, and the means for welding both edges of the metal strip 1 is not limited to the high frequency induction welding as described above, and other known methods are known. A welding method is preferably used.

[Advantages of the Invention] According to the method of the present invention, it is possible to mass-produce a heat transfer tube having a fine diameter and a fine mesh due to a mesh or a porous sheet on the inner surface, and having a smaller diameter and a thinner wall at low cost. Even when a heat pipe is manufactured, it is possible to easily form irregularities on the inner peripheral surface or the outer peripheral surface thereof.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a manufacturing process of a heat transfer tube in an embodiment of the method of the present invention, FIG. 2 is a partial plan view showing an arrangement of a low melting point alloy with respect to a metal strip plate in the embodiment of FIG. The drawing is a partially enlarged sectional view of the heat transfer tube manufactured in the embodiment of FIG. DESCRIPTION OF SYMBOLS IN MAIN FIGURES 1 is a metal strip, 1'is a composite sheet, 11 is a manufactured heat transfer tube, 2 is a low melting point alloy, 3 is a mesh, 10, 20 and 30 are uncoilers, 4 is a feeding roll, 5 Is a pressure roll, 6 is a heating furnace, 70 to 77 are forming rolls, and 9 is an induction coil.

Claims (1)

[Claims] 1. A step of fixing a mesh or a porous sheet with a melted low melting point alloy on one or both sides of a metal strip, and rolling the metal strip in the width direction to weld both edges of the strip. And a step of manufacturing the heat transfer tube.