JPH0125834Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is generally installed and used in many vehicles and other various machines and devices as supply paths for oil supply, air supply, etc.
This invention relates to an improvement in a connecting tube end structure provided at the end of a relatively thin-walled, small-diameter metal tube having a tube diameter of about 30 m/m or less.

As shown in FIG. 4, the conventional connecting pipe end structure simply has an outwardly opened flare 12 at the end of the piping body 11. Therefore, when using the connection, with the flare 12 in contact with the conical bearing surface 13' protruding from the bottom of the connection hole of the mating joint main body 13, as the tightening nut 14 spirals, the tightening nut side Due to this direct clamping structure, the flare 12 is subjected to extremely thin wall deformation as pressure is applied during tightening, and the lower part of the neck of the flare is This combined with the twisting tendency caused by the flare and vibrations during installation and use caused cracks and breakage to occur from around the 12 part of the flare. Additionally, there are other problems related to this thin wall deformation, such as the fact that it is impossible to reconnect and use the device after it has been removed.

The purpose of the present invention is to provide a connecting pipe end structure for thin-walled, small-diameter metal pipes that extremely effectively solves the above-mentioned problems.
To explain the figure in detail, the thin-walled and small-diameter piping body 1 is
It is constructed by integrally protruding a flare 2 having a coaxial shape and opening outward at the connecting end, and a brim-like bulging wall 3 which is continuous to the back of the flare and is double bent toward the outer circumference. It is. When connecting and using such a piping body 1, the flare 2 portion is attached to a conical seat surface 4' protruding from the bottom of the connection hole on the side of the mating joint body 4.
At the same time, the bulging wall 3 is pressed by the circumferential surface of the installation hole of the tightening nut, and the end of the pipe is pinched and connected between the bulging wall 3 and the tightening nut 5. It is something that must be done.

As described above, according to the connecting tube end structure according to the present invention, in particular, the flange-shaped bulging wall 3 integrally provided at the back has the function of engaging with the tightening nut 5, and the joint body 4
Pressure is applied between the seat surface on the outside of the side tip and the circumferential surface of the installation hole of the tightening nut 5, and the flare 2 part is kept in strong pressure contact with the conical seat surface 4', and the flare 2 part is directly attached. Since clamping pressure is avoided, when the connection is used, there is no concern about thin wall deformation due to clamping pressure at the two flare parts as in the conventional technology, and therefore there is no deterioration in mechanical strength due to thin wall deformation and tendency to twist at the lower part of the neck. This can prevent cracks and breakage in the vicinity of the flare 2, and can also provide a locking function to the tightening nut 5.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of a connecting tube end structure of a thin-walled small diameter metal tube according to one embodiment of the present invention, FIG. 2 is a partially cutaway side view of the same according to another embodiment, and FIG. The figure is a partially cutaway sectional view showing the connected state of use shown in FIG. 1, and FIG. 4 is a partially cutaway sectional view of the connected state of use according to the conventional example. 1...Piping body, 2...Flare, 3...Bulging wall.

Claims (1)

[Scope of utility model registration request] In a tube end structure in which the end of the piping body has a flare shape that opens coaxially outward, a tightening nut 5 installed on the piping body 1 side is attached to the outer peripheral side of the flare 2. A doubly bent flange-like bulging wall 3 that is engaged with the circumferential surface of the installation hole is protruded, and as the tightening nut 5 is screwed and pressed against the mating joint body 4, the flare 2 portion is pushed toward the joint body 4 side. The thin-walled thin nut is configured so as to be brought into strong pressure contact with the conical bearing surface 4' provided at the bottom of the connecting hole, and to press the circumferential surface of the mounting hole of the tightening nut against the bulging wall 3. Connecting pipe end structure for diameter metal pipes.