JPH11123593A - Welding method of copper tube and adjusting tool for gas pressure inside copper tube in welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely exert an antioxidation function without an adverse effect on the penetration of a filler metal for example and to effectively prevent generation of scales by spraying an antioxidant such as an ester based aerosol type into a copper tube. SOLUTION: This adjusting tool is constituted such that, in welding copper tubes 11 to each other with a tube joint 12 by spraying an antioxidant A such as an ester based aerosol type into each copper tube 11, each opening end of the tube 11 is blocked with a required blocking member 14, 15, that an escape hole 16 for adjusting gas pressure is provided in one of the blocking members at least, and that, while the gas is suitably released which is generated with the heating of the antioxidant, the gas pressure inside the tube is properly adjusted and retained. In addition, the blocking member 14, 15 consists of a blind blocking cap body 14, which is freely attachable and detachably to the opening end of the copper tube 11, and of a gas pressure adjusting cap body 15 which is provided with the escape hole 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for welding a copper pipe at the time of piping such as refrigeration and air conditioning, and a tool for adjusting the gas pressure in the pipe at the time of welding the copper pipe.

[0002]

2. Description of the Related Art Copper tubes have good workability, corrosion resistance, etc., are beautiful in color, and are relatively inexpensive. It is generally widely used as a piping material.

By the way, when such a copper tube is welded and connected at the time of piping such as refrigeration and air conditioning, the inside of the copper tube is oxidized by a heating action at the time of welding to produce a scale.
It causes various adverse effects. For this reason, conventionally, in order to prevent such oxidation inside the copper tube, a welding method in which nitrogen gas is ejected from one end opening of the copper tube toward the other end opening thereof at the time of welding has been widely adopted. However, while this copper pipe welding method can effectively prevent oxidation inside the copper pipe, it is very difficult in actual piping work to carry a heavy nitrogen cylinder and to make it difficult to manage and check. Workability was poor.

In order to solve the above-mentioned problems of the prior art, a method of welding a copper pipe by spraying a required antioxidant such as an ester type aerosol into the copper pipe has been proposed. Explanation will be given based on FIG. First,
A required antioxidant A such as an ester-based aerosol type is sprayed from the opening of each copper tube 11 to be connected (see FIG. 5). Thereafter, the copper pipes 11 to be connected are connected to each other via the copper elbow 12, and the connection portions are welded by a required welding means 13 such as a gas welding method or a brazing method (see FIG. 6). At this time, the antioxidant A attached to the inner peripheral surface of the copper tube 11 is decomposed and gasified by the heating action during welding, and is reduced while filling the inside of the copper tube 11 to oxidize the inner peripheral surface of the copper tube 11. To prevent the occurrence of scale.

In the above-mentioned conventional example, the operation can be performed very easily. On the other hand, the required oxidation such as an ester-based aerosol type is performed under the condition that both ends of the copper tube 11 to be brought into contact are opened. Since the antioxidant A is sprayed and welded, the antioxidant A is easily decomposed and gasified by the heating action at the time of welding, and easily flows out through the openings at both ends of the copper pipe 11. In addition, the reducing atmosphere in the copper tube 11 is easily damaged, and the inner peripheral surface of the copper tube 11 is easily oxidized to generate scale.

In order to solve the problems of the conventional example, a method of spraying an antioxidant into the inside of the copper pipe and then welding while closing the openings at both ends can be considered. While it can effectively prevent oxidation of the surface, the gas pressure inside the copper tube becomes abnormally high due to the decomposition and gasification of the antioxidant, which adversely affects the penetration of the welding braze and easily causes welding defects. is there.

The present invention solves the problems of the prior art at a glance, and sprays a required antioxidant such as an ester-based aerosol type into the inside of a copper tube to prevent oxidation without adversely affecting the penetration of a welding wax. An object of the present invention is to provide a method for welding a copper pipe, which can surely exhibit its function and effectively prevent the occurrence of scale, and a gas pressure adjusting tool used at the time of such welding.

[0008]

That is, the invention according to claim 1 of the present application provides a required antioxidant, such as an ester-based aerosol type, inside each copper tube in order to connect the copper tubes with a pipe joint. Spraying and welding
Each opening end of the copper pipe is closed with a required closing member, and at least one of the closing members is provided with a relief hole for adjusting gas pressure, and the relief hole is generated by heating the antioxidant from the relief hole. A gist of the present invention is a method for welding a copper pipe, characterized in that the gas pressure in the pipe is appropriately adjusted and held while appropriately releasing gas.

In the method for welding a copper pipe according to the present invention, the gas pressure in the copper pipe is always appropriately adjusted and maintained while appropriately releasing gas generated by decomposition and gasification of the antioxidant during welding to the outside. At the very least, the antioxidant function can be reliably exerted without adversely affecting the reducing atmosphere and the penetration of the welding braze.

Further, the invention according to claim 2 of the present application provides a blind closing cap body detachably attached to an open end of a copper pipe connected by welding means via a pipe joint,
A gas pressure adjusting cap body having an escape hole of the same required diameter, which is appropriately attached to the opening end of a copper pipe to be connected to each of the cap bodies, and a gas generated by heating the antioxidant during welding. The gist of the invention is a tool for adjusting the gas pressure in a pipe at the time of welding a copper pipe, which is characterized in that the gas pressure in the pipe is appropriately adjusted and held while being appropriately released.

The gas pressure adjusting tool according to the present invention has a capping member fitted to one end of one copper tube to be welded and a gas pressure adjusting device attached to one end of the other copper tube. The cap body is fitted for use. Then, while spraying a required antioxidant such as an ester-based aerosol type from the opening end of each copper tube to the inside, and connecting with a pipe joint to perform welding,
While appropriately releasing gas generated by decomposition and gasification of the antioxidant from the escape hole of the gas pressure adjusting cap body,
The gas pressure in the copper tube is always adjusted and maintained properly.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the drawings, reference numeral 14 denotes a blind closing cap body which can be fitted to the opening edge of the copper tube 11 to be welded, and reference numeral 15 denotes a gas pressure adjusting cap body which can be similarly fitted. The gas pressure adjusting cap body 15
Is formed with a small-diameter relief hole 16 at the center of the hole. Other parts are the same as those of the conventional example, and the same reference numerals indicate the same parts.

First, a closing cap body 14 is fitted to one end of one copper tube 11 to be welded,
A gas pressure adjusting cap body 15 is attached to one end of the other copper tube 11.
After that, a required antioxidant A such as an ester-based aerosol type is sprayed from the open end of each copper tube 11 (see FIG. 1). Thereafter, the copper pipes 11 are connected to each other via the elbows 12, and the connection portions of the copper pipes 11 are welded by required welding means 13 such as brazing (see FIG. 2). At this time, the antioxidant A adhering to the inner peripheral surface of the copper tube 11 is decomposed and gasified by the heating action during welding and fills the copper tube 11 to generate a gas pressure. By appropriately discharging the generated gas through the escape hole 16 of the body 15, the gas pressure in the copper tube 11 can be constantly adjusted and maintained. For this reason, the antioxidant function can be reliably exerted without adversely affecting the reducing atmosphere in the copper tube 11 and the penetration of the welding braze, and the occurrence of scale can be effectively prevented, so that reliable welding can always be performed. Things. When the welding is completed, the closing cap body 14 and the gas pressure adjusting cap body 15 are removed from both ends of the copper pipe 11, respectively, and the welding operation is completed.

In the above embodiment, the gas pressure adjusting cap body 15 has a small-diameter relief hole 16 formed at the center thereof. However, the present invention is not limited to this. 3 and 4 according to the diameter and length of the tube 11.
As described above, the diameter of the escape holes 26 and 36 may be changed to a required size and formed on the gas pressure adjusting cap bodies 25 and 35, and in some cases, the escape holes 16 and 26.3 may be formed.
6 may be provided with a required relief valve. The copper pipe 11 is welded while being connected via an elbow 12, but is connected to a required shape through another pipe joint such as a cheese or by combining these pipe joints. It can be applied sufficiently to welding, and in such a case, a plurality of gas pressure adjusting cap bodies 15, 25, 35 are fitted to increase the number of escape holes 16, 26, 36. It is possible to make a mistake. Further, as an antioxidant, ester-based azo-
However, the present invention is not limited to this, and can be applied when other antioxidants similar to this are used.

[0015]

The invention according to claim 1 of the present application is configured as described above, so that the gas generated by decomposition and gasification of the antioxidant during welding of the copper pipe is appropriately released to the outside while being released. The gas pressure inside the copper tube is always adjusted and maintained properly.
The antioxidant function can be surely exerted without adversely affecting the reducing atmosphere and the penetration of the welding braze, and the copper pipe can always be reliably welded.

Since the invention according to claim 2 of the present application is constructed as described above, a closing cap body is fitted to one end of one copper tube to be welded, and the other copper tube is fitted to the other copper tube. With a very simple operation of fitting a cap body for gas pressure adjustment to one end, a required antioxidant such as an ester-based aerosol type is sprayed from the open end of each copper pipe to the inside, and connected by a pipe joint. During welding, the gas generated by the decomposition and gasification of the antioxidant during welding is released to the outside of the gas pressure adjusting cap body appropriately, and the gas pressure in the copper tube is always adjusted appropriately. Can be adjusted and held.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, in which one end of one copper tube 11 to be connected is provided with a closing cap body 14;
While fitting the gas pressure adjusting cap body 15 to one end of the other copper tube 11,
It is a longitudinal cross-sectional view which shows the state which sprays the antioxidant A from the opening end part.

FIG. 2 is a partially enlarged longitudinal sectional view showing the welding state.

FIG. 3 is a perspective view showing another gas pressure adjusting cap body 25. FIG.

FIG. 4 is a perspective view showing another cap body 35 for adjusting gas pressure.

FIG. 5 shows a conventional example, and a copper tube 1 to be connected.
1 is a longitudinal sectional view showing a state in which an antioxidant A is sprayed into 1.

FIG. 6 is a partially enlarged longitudinal sectional view showing the welding state.

[Description of Signs] 11 Copper tube 12 Elbow 13 Welding means 14 Closure cap body 15, 25, 35 Gas pressure adjustment cap body 16, 26, 36 Escape hole

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // B23K 5/14 B23K 5/14 9/23 9/23 E

Claims (2)

[Claims] An opening end of each of the copper tubes is required to be welded by spraying a required antioxidant such as an ester-based aerosol type into each of the copper tubes so as to connect the copper tubes with a pipe joint. At least one of the closing members is provided with a relief hole for gas pressure adjustment, and the gas generated in the pipe along with the heating of the antioxidant is appropriately released from the relief hole to reduce the gas pressure in the pipe. A method for welding copper pipes, characterized by appropriately adjusting and holding. 2. A blind closing cap body detachably attached to an open end of a copper pipe connected by welding means via a pipe joint, and a gas pressure adjusting cap body having an escape hole of the same required diameter. The above-mentioned cap bodies are appropriately attached to the open ends of the copper tubes to be connected, and the gas pressure generated during heating of the antioxidant during welding is appropriately released and the gas pressure in the tubes is appropriately adjusted and held. A tool for adjusting the gas pressure in a pipe when welding a copper pipe.