KR20180017561A - Heat exchange pipe expanding method - Google Patents

Abstract

The present invention relates to a method to expand a heat exchanger pipe. According to the present invention, the method to expand the heat exchanger pipe comprises: a step of preparing a plurality of plate-shaped heat exchanger fins and a hollow pipe which penetrates the heat exchanger fins; a step of forming a male screw unit on the outer circumference to prepare a rotary pipe-expanding core inserted into the inner circumference of the pipe to rotate along the inner circumference of the pipe and expand the pipe; a step of inserting the pipe into the heat exchanger fins; a step of spreading a lubricant on the male screw unit of the rotary pipe-expanding core; and a step of rotating and moving the rotary pipe-expanding core along the inner circumference of the pipe to expand the inner circumference of the pipe. That is, the present invention is able to prevent a lubricant from adhering by moisture generated by dew condensation in the pipe and to prevent damage to the pipe by an increased frictional force in case of pipe expansion. The present invention is able to rotate the rotary pipe-expanding core by a screw method, to make the lubricant evenly adhere to a groove in the male screw unit, and to reduce the frictional force in case of pipe expansion, thereby reducing the wall thickness as compared to the existing wall thickness to reduce costs and a defective rate.

Description

HEAT EXCHANGE PIPE EXPANDING METHOD [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of expanding a heat exchange pipe, and more particularly, to a method of expanding a heat exchange pipe by improving the assembly of the pipe and the heat exchange fin.

Generally, heat exchange pipes used in heat exchangers such as refrigerators, air conditioners, and automobiles are mostly made of aluminum or copper.

Heat exchange pipes are a measure of the ability to reduce the performance and power consumption of products that require efficient heat dissipation.

Therefore, in order to increase the heat radiation area of the heat exchange pipe, a cooling blade or a heat exchange fin is attached to the outer periphery of the pipe, or the outer surface area of the pipe is increased.

Most of the heat exchange pipes have a circular cross sectional shape and a plurality of heat exchange fins are formed at intervals on the outer circumferential surface of the hollow pipe in order to increase the outer surface area of the pipe and increase the heat exchange efficiency.

Particularly, in the case of a heat exchange pipe to which a plate heat exchange fin is attached, the heat exchange efficiency of the heat exchange pipe is determined based on whether or not the pipe and the heat exchange fin are firmly coupled to each other.

That is, there is a problem that heat exchange is restricted when the pipe and the heat exchange fin are not tightly coupled to each other.

Therefore, conventionally, the heat exchange fins are simply inserted into the outside of the pipe, so that there is a gap between the outer circumferential surface of the pipe and the inner circumferential surface of the heat exchange fin, thereby failing to efficiently perform heat exchange.

Further, even if the heat exchange fin is firmly coupled to a part of the outer circumferential surface of the pipe, the heat exchange function is not firmly coupled to the other part, so that the heat exchange action occurs unevenly depending on the position, and the overall heat exchange efficiency is lowered.

Thus, in the case of the conventional finned heat exchange pipe, the pipe is expanded to couple a plurality of plate-shaped heat exchange fins to the outer peripheral surface of the pipe.

That is, in the conventional finned heat exchange pipe, a plurality of heat exchange fins are slidably coupled to the outer peripheral surface of the pipe, and a plurality of heat exchange fins are fixed with a jig, The tubular core is forcibly inserted into the inner circumferential surface of the pipe and linearly moved along the longitudinal direction of the pipe so that the plurality of heat exchanging fins are firmly coupled to the outer circumference of the pipe with respect to the inner circumferential surface of the pipe.

On the other hand, when moisture is present on the inner peripheral surface of the pipe to be expanded, the frictional resistance between the core for deepening and the pipe becomes large, and the pipe is bent due to excessive pressing force of the core for corrugation.

In the conventional method of expanding a heat exchange pipe, as the core for diffusing is inserted into the inner circumferential surface of the pipe in a forced interference fit, the pipe moves linearly along the longitudinal direction of the pipe, There is a problem that it causes defects.

In order to solve such a problem, there is a problem that a pipe having a thickness more than necessary is required, which not only raises manufacturing cost but also hinders heat exchange.

Domestic Public Utility Model Bulletin No. 10-1993-0008340 (Name of Design: Nonferrous metal pipe expanding machine, published on May 24, 1993)

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to reduce frictional resistance between a pipe and a rotating expanding core during an expanding operation, to stably expand a pipe without applying excessive force to the pipe, The present invention provides a method of expanding a heat exchange pipe that can use a pipe having a thickness.

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat exchanger comprising a plurality of plate heat exchange fins and a hollow pipe passing through the plurality of heat exchange fins; Forming a male screw portion on an outer periphery of the pipe and providing a rotatable expansion core inserted into the inner periphery of the pipe and rotating and expanding along the inner periphery of the pipe; Inserting the pipe into the plurality of heat exchange fins; Applying a lubricant to the male screw portion of the rotary expanding core; and rotating the rotary expanding core along the inner periphery of the pipe to expand the inner circumference of the pipe. Method. ≪ / RTI >

Here, the pipe and the plurality of heat exchange fins are made of aluminum or copper.

According to the present invention, it is possible to reduce the frictional resistance between the pipe and the rotating expanding core during the expanding operation, to stably expand the pipe without imposing excessive force on the pipe, to reduce manufacturing defects, have.

1 is a flowchart of a method for expanding a heat exchange pipe according to the present invention,
FIG. 2 is a cross-sectional view illustrating a process of expanding a heat exchange pipe according to the present invention,
Figure 3 is a perspective view of the rotatable expanding core of Figure 2;

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, Is provided to fully convey the scope of the present invention to a technician, and the present invention is only defined by the scope of the claims.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense that is commonly understood by one of ordinary skill in the art to which this invention belongs. In addition, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings.

Prior to the description, it is to be noted in advance that the pipe can be made of a material excellent in ductility and heat conductivity such as aluminum and copper.

FIG. 1 is a flowchart of a method for expanding a heat exchange pipe according to the present invention, and FIG. 2 is a cross-sectional view illustrating a process of expanding a heat exchange pipe according to the present invention.

A method of expanding a heat exchange pipe according to the present invention will be described as follows.

First, a plurality of plate-shaped heat exchange fins 10 and a hollow pipe 20 penetrating a plurality of heat exchange fins 10 are provided (S10).

The heat exchange fin (10) is formed by drilling an insertion hole (15) having a diameter corresponding to the outer diameter of the pipe (20) at the center of the plate-like material.

Here, it is preferable that the diameter of the insertion hole (15) has a dimension of a tolerance to be half fitted with the outer diameter of the pipe (20).

Next, a rotating expanding core 30 inserted into the inner periphery of the pipe 20 and enlarging the inner periphery of the pipe 20 is provided (S20).

The rotary expanding core 30 has a rod shape having a predetermined length. As shown in FIG. 2, a male threaded portion 35 having threads and threaded bosses is formed on the outer periphery of the expanding core 30.

Here, the order of arranging the plurality of heat exchange fins 10 and providing the rotary expanding core 30 may be changed.

Then, the pipe 20 is inserted into the insertion hole 15 of the plurality of heat exchange fins 10 (S30).

At this time, the plurality of heat exchange fins 10 are disposed at intervals in the pipe 20, and are intermeshed with the pipe 20, for example, slidingly coupled.

Subsequently, the lubricant 5 is applied to the male threaded portion 35 of the rotating expanding core 30 (S40).

2, the rotary expanding core 30 is rotated and moved along the inner periphery of the pipe 20 while the plurality of heat exchange fins 10 are fixed by the jig, (S50).

On the other hand, when the rotary expanding core 30 is moved along the inner periphery of the pipe 20, the lubricant 5 applied to the groove of the male threaded portion 35 of the rotary expanding core 30 contacts the rotary expanding core 30 and the pipe 20 so that the frictional resistance between the rotary expanding core 30 and the inner periphery of the pipe 20 is minimized and the rotary expanding core 30 is smoothly moved along the inner periphery of the pipe 20 , The pipe 20 can be stably expanded without applying excessive force.

That is, the lubricant is not adhered to the inside of the pipe 20 due to the moisture generated by the condensation phenomenon, thereby preventing the pipe 20 from being damaged due to an increase in frictional force during the expansion.

The rotary expanding core 30 is screwed and the lubricant is evenly adhered to the grooves of the male threaded portion 35 to reduce frictional force during the expanding operation so as to reduce the thickness of the wall compared with the existing wall to reduce costs and reduce defects .

As a result, the inner circumference of the pipe 20 is enlarged, so that the plurality of heat exchange fins 10 are firmly coupled to the outer periphery of the pipe 20, and at the same time, the heat exchange pipe 1 without cracking can be obtained.

As described above, according to the present invention, after the rotary expanding core formed with the male thread portion on the outer periphery is poured into the inner periphery of the pipe inserted into the plurality of heat exchange fins, the rotary expanding core is rotated and moved along the inner periphery of the pipe, By expanding the inner circumference, it is possible to reduce the frictional resistance between the pipe and the rotary expanding core, to stably expand the pipe without applying excessive force to the pipe, to reduce manufacturing defects, and to use the pipe with the optimum thickness.

1: Heat exchange pipe 5: Lubricant
10: heat exchange pin 15: insertion hole
20: Pipe 30: Rotary expansion core
35:

Claims (2)

Providing a plurality of plate heat exchange fins and a hollow pipe through the plurality of heat exchange fins;
Forming a male screw portion on an outer periphery of the pipe and providing a rotatable expansion core inserted in the inner periphery of the pipe and rotating and extending along the inner periphery of the pipe;
Inserting the pipe into the plurality of heat exchange fins;
Applying a lubricant to the male threaded portion of the rotating expanding core;
And rotating and expanding the rotary expanding core along the inner periphery of the pipe to expand the inner periphery of the pipe. The method according to claim 1,
Wherein the pipe and the plurality of heat exchange fins are made of aluminum or copper.

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