JPS628477Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is generally installed and used in many automobiles or various machines, equipment, devices, etc. as supply channels for oil supply, air supply, etc. The present invention relates to an improvement in a structure for brazing and fixing an end of a thin-walled metal pipe having a small diameter and a wall thickness of about 2 m/m or less and a connecting end fitting.

As shown in FIG. 4, the conventional brazing fixing structure for connection end fittings is such that the front end side in the longitudinal direction is stepped in the connection brazing hole 15 provided on the end fitting 11 side having various shapes. The branch pipe 14 has a reduced diameter cylindrical wall 13 connected to the attached part, and the reduced diameter cylindrical wall side is soldered 16, and the piping body 12 is soldered 17 to the cylindrical wall on the rear end side. Was.

However, due to the structure in which this branch pipe 14 is brazed and welded 16 to the diameter-reduced cylindrical wall 13 connected to the stepped portion, it is difficult for inexperienced workers to manually roast the mutually engaging peripheral wall portions with a burner. Overheating causes brittleness due to excessive growth of metal particles near the base of the heated stepped section on the branch pipe 14 side. Due to the tightening, the root of the stepped portion on the side of the branch pipe 14 often suffers from cracks and breakage due to dust and vibration during installation and use.

The purpose of the present invention is to provide a structure for brazing and fixing the end of a small-diameter metal pipe and a connecting end fitting, which extremely effectively solves the above-mentioned problems. 3, in the present invention, the metal piping body 2 has a cylindrical wall 3 on the tip side preferably having the same pipe diameter as the piping body, and the outward cross section is bridge-like, knot-like, or back-shaped. It is formed by integrally projecting an annular bulging wall portion 4 with a slanted shape, etc., and has a diameter and wall thickness equal to or less than the above-mentioned pipe diameter and wall thickness, and the cylindrical wall 3 can be connected to a connection having various shapes. With the connecting brazing hole or the connecting brazing tube hole 5 on the side of the end fitting 1 being inserted and engaged, the connecting brazing hole or the connecting brazing tube hole and the entire surface of the cylindrical wall 3 are connected. The mutually engaging circumferential surfaces are soldered and welded 6. In addition, FIG. 5 shows comparative characteristic curves of the breakage test, where A shows the product of the present invention and B shows the conventional product.

As described above, according to the present invention, even in the case of excessive tightening due to defects in the product bending shape, etc., taking advantage of the embrittlement caused by overheating during the soldering work in the six soldering parts, As it is tightened, the annular directionality of the bulging wall portion 4 exerts a free direction adjustment function due to elastic deformation, and the abnormal fatigue stress concentrated on the piping body 2 near the solder weld 6 portion. As a result, cracks and breakage on the side of the pipe body 2 near the welded 6 parts are extremely reduced even when used under vibration conditions, as shown in Fig. 5. As a result, the mechanical strength against cracking and breakage was significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway sectional view showing a brazing fixing structure between the end of a small diameter metal pipe and a connecting end fitting according to one embodiment of the present invention, and FIGS. 2 and 3 are views of other embodiments, respectively. FIG. 4 is a partially cutaway sectional view of the brazing fixing structure according to the conventional example, and FIG. 5 is a comparative characteristic curve diagram. 1... Connection end fitting, 2... Metal piping body, 3...
...Cylindrical wall portion, 4...Bulging wall portion, 5...Connection brazing hole or connection brazing cylindrical hole, 6...Brazing welding.

Claims (1)

[Scope of utility model registration request] On the tip side, there is a cylindrical wall 3 having substantially the same pipe diameter.
The cylindrical wall portion of the metal piping body 2, which has an annular bulging wall 4 integrally projecting outward, is connected to the connection brazing hole on the connection end fitting 1 side or the connection brazing cylindrical hole 5. 3, and is constructed by welding a solder 6 to the mutually engaging peripheral surface of the connecting brazing hole or the connecting brazing cylindrical hole and the entire surface of the cylindrical wall 3. Brazed fixation structure between the diameter metal pipe end and the connecting end fitting.