JPS59191569A - Method and device for joining end of copper pipe and steel plate - Google Patents

Abstract

PURPOSE:To obtain a beautiful and strong joint part which is formed with a rear side fillet bead without using a brazing means in the stage of performing titled joining with the arc generated by a nonconsumable electrode in an inert gaseous atmosphere by shielding specifically the joint part with inert gas. CONSTITUTION:The end part of a copper pipe 1 is inserted into the hole provided to a steel plate, and the end face of the pipe 1 is held flush with the plate 2 or slightly retreated therefrom. The arc of a TIG torch 4 in the inert gaseous atmosphere covered with a cover 3 is run at >=1 time round the circumference of the pipe 1 to melt both the circumferential edge of the hole of the plate 2 and the end of the pipe 1, by which a deposited metal 5 is obtd. The gas on the arc side is at the same time passed in the pipe 1 and is discharged to the outside from the end of the pipe 1 on the side opposite from the joint part. The rear side of the joint part is thus shielded by the inert gas and the fillet bead on the rear side is formed.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention connects the periphery of a hole in a steel plate and the rim of a copper tube using arc heat using a non-consumable electrode in an inert gas atmosphere. The present invention relates to a method and apparatus for forming a good back fillet bead by shielding the back side opposite to the arc side with an inert gas.

[Background of the invention]

BACKGROUND ART Conventionally, when joining a copper pipe to a container made of thin-walled steel plate as an inlet pipe or an outlet pipe, a brazing method is usually used. However, the 7 hex used in heel waxing remains after bonding and is corrosive, requiring additional steps such as an acid purification process to remove the heel.

[Purpose of the invention]

The present invention has been made in view of the above, and is a pipe end connection between a copper pipe and a steel plate that can form a beautiful and strong joint with the formation of a fillet heat on the back side without using brazing. Aimed to provide legal and equipment.

[Summary of the invention]

The present invention has a structure in which the end of a copper pipe is inserted into a hole provided in a steel plate, and the end of the pipe is connected by melting and solidifying both the steel plate and the copper pipe using arc heat from a non-consumable electrode in an inert gas atmosphere. Legally, shield with inert gas from the back side opposite to the arc side, '#! In this method, a fused portion is formed to join the ends of the tube.

At this time, melting due to arc heat is characterized in that both the steel plate and the copper pipe are melted, and the molten metal protrudes to the back side opposite to the arc side, forming a back fillet and a dome. In this case, the reason for performing an inert gas shield on the back side is to increase the wettability of the steel plate and copper pipe surface to make the joint easier and stronger, and the other reason is to This is to prevent oxidation of the formed back fillet bead running surface and obtain a beautiful surface.

The present invention provides a method and apparatus for realizing such a joining method. As a final method to achieve backside shielding, the end face of the joint is shielded with inert gas by a hood that covers the end face of the copper pipe provided on the arc side, and at the same time, the inert gas is introduced from inside the copper pipe to the good side of the joint NS. This is used to guide and shield the back side of the molten part.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIG. 1 and FIG.

In Fig. 1, the end of the copper pipe l is inserted into the hole provided in the steel plate 2, and the end face of the copper pipe is held flush with the steel plate 2 or in a slightly retracted state, and is covered with a cover 3. An arc generated by the non-consumable electrode 4 is caused to travel around the circumference of the copper pipe once or more than once in an inert gas atmosphere. Moreover, one embodiment of a method for shielding the back side with inert gas on the opposite side from the arc side is also shown. FIG. 2 shows the cross-sectional shape of the joint obtained by this method, in which a back fillet bead is formed and no notch in the unwelded part remains. Moreover, this provides a beautiful surface condition and eliminates the need for post-treatment after bonding.

〔Effect of the invention〕

As explained above, according to the present invention, the copper plate and copper pipe themselves melt to become weld metal, and the joining method is extremely simple without requiring an additional filler rod. have.

Further, according to the method of the present invention, it is possible to obtain a back fillet bead with a beautiful surface and sufficient dimensions.

This eliminates the need for post-processing after bonding, simplifies the equipment and process, and provides an economical bonding method.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the embodiment of the present invention. Note that the additional inert gas shown in FIG. 1 can be omitted by modifying the hood shape.

Claims (1)

[Scope of Claims] 1. In a method of joining the pipe end edge of a copper pipe and the periphery of a plate hole in a steel plate in a structure in which the end of the copper pipe is inserted into a hole provided in a steel plate, the method is performed in an inert gas atmosphere. The arc generated by the non-consumable electrode melts both the periphery of the hole in the steel plate and the end of the copper pipe, and at the same time, the inert gas on the arc side is passed through the copper pipe, and the inert gas on the side opposite to the joint is melted. A pipe end of a copper pipe and a steel plate, characterized in that an inert gas flowing out from the end of the copper pipe is guided to the back side of the joint, and the back side is also shielded with the inert gas to form a fillet bead on the back side. Joining method. 2. In a device that connects the edge of one end of a copper pipe and the periphery of a hole in a steel plate, in which the end of a copper pipe is inserted into a hole in a steel plate, a non-consumable electrode is used in an inert gas atmosphere. Features include a torch that can generate an arc, a hood that covers the entire end surface of the copper pipes to be joined, and a structure that guides the inert gas that has passed through the copper pipe to the back side of the molten part. Pipe end joining equipment for copper pipes and steel plates.