JPH11311494A - Pipe joint method for tank for heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a member which enables self-holding of the tip part of a pipe in a pipe insertion hole of a tank in soldering between the tank for heat exchanger made of metal and the pipe. SOLUTION: A hole rim part of a pipe insertion hole 2 of the body 1 of a tank is made as burring work part 4 cylindrically protruding on the side of an internal surface and moreover, an open rim on the side of an external surface is formed slightly in radius for guiding a pipe. A spool part 5 and a circular protruded part 6 for a stopper are formed at the tip part of the pipe 3 from the side of the tip thereof to make the interval between both of them coincide with the length of the burring work part 4. The pipe 3 is self-held on the body 1 of the tank by forcing the pipe 3 into the pipe insertion hole 2, a condition under which insertion parts of both of them are soldered and fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining an aluminum radiator tank for cooling engine cooling water to a cooling water inlet / outlet pipe brazed to a side surface of the tank as an example.

[0002]

2. Description of the Related Art A joining method of a tank and a pipe of an aluminum heat exchanger has been performed as follows. FIG.
As shown in FIG. 1, a pipe insertion hole 2 is formed in a side surface of a tank body 1 formed in a box shape. The burring portion 4 is formed by projecting the edge of the pipe insertion hole 2 toward the outer surface. Next, an annular convex portion 6 for stopper is provided at the tip of the pipe 3.
And the tip of the pipe 3 is inserted into the burring portion 4. Next, the leading edge of the pipe 3 is connected to the tank body 1.
Is expanded from the inner surface side to form an expanded portion 9. The outer surface of the pipe 3 or the inner surface of the tank body 1 is coated with a brazing material in advance. Then, the periphery of the tube plate into which a number of tubes have been inserted is fitted into the opening of the tank body 1, and the whole is inserted into a high-temperature furnace in a state of being assembled. Then, the previously coated brazing material was melted, and then solidified to fix the components in a liquid-tight manner by brazing.

[0003]

The conventional method of joining a tank and a pipe requires a step of mechanically expanding and fixing the tip of the pipe so that the pipe does not fall off the tank during brazing. It was extremely troublesome to do this from the inside of the narrow tank. Therefore, an object of the present invention is to provide a method for joining pipes of a heat exchanger tank with good workability by eliminating such mechanical opening work.

[0004]

According to the method for joining pipes of a heat exchanger tank of the present invention, one end of a metal pipe 3 is inserted into a pipe insertion hole 2 formed in a side surface of a metal tank body 1. In a method for joining pipes of a tank for a heat exchanger in which the insertion portion is brazed and joined in a liquid-tight manner, a burring processing portion 4 is provided on the inner surface of the hole of the pipe insertion hole 2 so as to protrude slightly in a cylindrical shape. Then, an outer opening edge of the burring portion 4 is slightly formed in a pipe guide radius R, and a spool portion 5 having a slightly tapered spool at the outer peripheral edge of one end of the pipe 3 is expanded. The outer diameter of the rear end of the spool portion 5 projects slightly outward in the radial direction from the inner diameter of the front end of the pipe insertion hole 2, and the burring portion 4 extends from the spool portion 5 to the rear end side of the pipe 3. Separated by the length of An annular convex portion 6 for stopper is formed on the outer surface of the pipe 3 by bulging, and one end of the pipe 3 is pressed into the pipe insertion hole 2 from the outer surface side of the tank body 1 to form the spool portion 5. The rear end edge is engaged with the tip of the burring portion 4, and the insertion portion of the pipe 3 is brazed and fixed in this state.

[0005] According to this joining method, the burring portion 4 can be easily retained in the burring portion 4 simply by pressing the tip of the pipe 3 into the burring portion 4. Then, in this state, the insertion portion of the pipe 3 can be brazed, and a brazing structure with good workability and high strength can be provided.

[0006]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partial sectional view showing a preparatory stage of a method for joining pipes of a heat exchanger tank according to the present invention, and FIG. 2 is an explanatory diagram showing the next stage. The tank body 1 constitutes an aluminum tank for a radiator for cooling engine cooling water, and a pipe insertion hole 2 is formed on one side of the tank. At the edge of the pipe insertion hole 2, there is provided a burring portion 4 which projects slightly into a cylindrical shape on the inner surface side of the tank main body 1, and the outer edge of the burring portion 4 on the outer surface side is slightly used for pipe guiding. Are formed in R. It is preferable that the burring portion 4 is formed to have an extremely slightly tapered shape from the outer surface side opening toward the tip. Next, the pipe 3 has a spool portion 5 in which a slightly tapered spool is bulged at the outer periphery of one end portion thereof, and the outer diameter of the rear end of the spool portion 5 is slightly smaller than the inner diameter of the tip end of the pipe insertion hole 2. It projects outward in the radial direction. Further, an annular convex portion 6 for stopper is formed on the outer surface of the pipe 3 at a position separated from the spool portion 5 toward the rear end side of the pipe 3 by the length of the burring portion 4. The stopper annular convex portion 6 is formed to be larger than the opening edge of the burring portion 4.

Next, the front end of the pipe 3 is pressed into the pipe insertion hole 2 from the outer surface side of the tank body 1, and the rear end edge of the spool 5 is engaged with the front end of the burring portion 4.
The stopper annular projection 6 is brought into contact with the edge of the pipe insertion hole 2. Next, as shown in FIG. 2, the periphery of the tube plate 7 into which the many tubes 8 are inserted is fitted to the opening edge of the tank body 1. Although only the upper tank is shown in FIG. 2, the lower tank is formed in the same manner, and the upper and lower ends of the tube 8 are inserted into the respective tube plates 7. Further, fins (not shown) are interposed between the adjacent tubes 8. In the assembled state in this way, the whole is inserted into a high-temperature furnace, and the brazing material coated on at least one side of each part is melted, and then solidified, thereby integrally connecting the parts. In addition, it is brazed and fixed in a liquid-tight manner to complete an aluminum heat exchanger.

[0008]

According to the method for joining pipes of a heat exchanger tank of the present invention, a burring portion 4 protruding inward is provided.
A pipe guide radius R is formed slightly on the outer side opening edge of the pipe 3, and a spool portion 5 and a stopper annular convex portion 6 are formed at the tip of the pipe 3 at an interval between the burring portions 4 and
Since the outer diameter of the rear end edge of the spool portion 5 is slightly larger than the inner diameter of the burring portion 4, only the tip of the pipe 3 is press-fitted into the burring portion 4, and it is moved to the burring portion 4. Can be retained. Then, in this state, the insertion portion of the pipe 3 can be brazed, and a brazing structure with good workability and high strength can be provided.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a preparation stage of a method for joining pipes of a heat exchanger tank according to the present invention.

FIG. 2 is an explanatory view showing the next stage of the pipe joining method.

FIG. 3 is an explanatory view of a pipe joining method of a conventional heat exchanger tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tank main body 2 Pipe insertion hole 3 Pipe 4 Burring processing part 5 Spool part 6 Annular convex part for stopper 7 Tube plate 8 Tube 9 Expansion part

Claims (1)

[Claims] 1. A heat exchanger tank in which one end of a metal pipe 3 is inserted into a pipe insertion hole 2 formed in a side surface of a metal tank body 1, and the insertion portion is liquid-tight brazed and joined. In the pipe joining method, a burring portion 4 is provided on the inner surface of the hole of the pipe insertion hole 2 so as to protrude slightly in a cylindrical shape, and the outer opening edge of the burring portion 4 is slightly pipe-guided. The pipe 3 is provided with a spool portion 5 in which a slightly tapered spool is bulged at an outer peripheral edge of one end of the pipe 3, and a rear end outer diameter of the spool portion 5 is set to the pipe insertion hole 2. The outer periphery of the pipe 3 is located at a position slightly spaced from the spool 5 by a length of the burring portion 4 at the rear end side of the pipe 3 from the spool portion 5 and has an annular stopper. The convex portion 6 is formed to bulge, One end of the pipe 3 is pressed into the pipe insertion hole 2 from the outer surface side of the tank body 1, and the rear end edge of the spool part 5 is engaged with the tip of the burring processing part 4. A pipe joining method for a heat exchanger tank, wherein an insertion portion of the pipe 3 is brazed and fixed.