JP2553658Y2 - Connection flare structure at pipe end - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to a comparison of a pipe diameter of 20 m / m and a wall thickness of about 1.5 m / m or less, which are generally provided as an oil supply / supply path for an automobile or various machines and devices. The present invention relates to an improvement in a connection flare structure provided at a connection end portion of a metal tube having a small diameter and a thin wall.

Conventionally, as this type of connection flare structure,
For example, as shown in FIG. 3, it is formed with an opening wall (11 ') formed by a flare (11) at a connection end of a pipe (P') and a smooth conical wall (12) which simply opens outward, At the time of connection, the pressure receiving seat surface of the mating joint (13) and the pressing seat surface of the assembled nut (14) are configured so as to be firmly pressed and connected together with the screwing tightening.

[0003]

However, in such a conventional technique, since the structure of the smooth conical wall (12) causes the bearing surface of the flare (11) to abut on the mating pressure receiving seat surface in its entirety. The surface pressure does not easily rise and leakage is likely to occur. In addition, excessive tightening to cope with leakage due to one-sided contact on the mating pressure receiving seat surface due to variations in the bending shape on the pipe (P ') side,
Due to the structure of the pipe (P ') itself, which is relatively thin, and the state of installation under vibration, the fatigue stress is often concentrated at the lower part of the neck of the flare (11). There was a problem that induced.

The present invention has been made in view of the above-mentioned problems of the prior art. By providing a resiliently deformable wall at an opening wall formed by a flare, a resilient force is generated at the time of connection to generate surface pressure. The end of the tube can be increased to eliminate the need for excessive tightening force, while at the same time dispersing the stress concentration in the lower part of the flare to reduce fatigue and eliminating concerns about cracks and breaks in the lower part of the flare over a long period of time. The purpose of the present invention is to propose a connection flare structure.

[0005] In order to achieve the above object, the present invention provides a flare structure which is formed integrally with a tube end which is connected in a trumpet shape and which is formed along the peripheral wall of the opening wall formed by the flare. The gist is a connection flare structure at the pipe end, which is provided with a resiliently deformable wall consisting of an annular convex or concave part that generates an elastic force with clamping and tightening at the time of connection, at the middle waist. is there.

[0006]

According to the present invention, the structure of the resiliently deforming wall at the opening wall makes it possible to use the resilient force generated by the tightening of the nut with the pressure receiving seat surface of the joint. The surface pressure will be increased, and therefore, even if it is in one contact with the pressure receiving seat surface, an excessive tightening force is unnecessary, and at the same time, the stress concentration at the lower part of the flare neck can be reduced and effectively dispersed, Even under the arrangement in the vibrating state, the connection can be stably and reliably performed for a long period without worrying about cracks and breakage at the lower part of the neck.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway plan view of a connection flare structure at a pipe end of the present invention, and FIG. 2 shows another embodiment. FIG. 3 is a partially cut-away longitudinal sectional view showing the connection state of FIG. 1, and (1) is a flare at the end of the pipe (P), which is located at the connection end. And an annular convex portion (2 ') in the middle portion along the peripheral wall of the opening wall (1') formed by the flare which is provided integrally in a trumpet shape outward in the axial center direction (FIG. 1) Or a recess (not shown) or an outwardly extending annular upright (2 ") at its tip
(FIG. 2). The elastic deformation wall (2) is provided. At the time of connection, the elastically deformed wall portion is
The pressure receiving seat surface of (3) and the pressing seat surface of the assembled nut (4) are connected by being resiliently pressed together with the screwing.

The elastically deformable wall (2) may be formed as an opening wall if desired.
It is also possible to form a wave shape over the entirety of (1 ′).

[0009]

[Effects of the Invention] As described above, the connection flare structure according to the present invention is constructed by providing the elastically deformable wall (2) by pressing only in the opening wall (1 ') formed by the flare (1). However, the resilient force generated by the resiliently deforming wall portion generated by the tightening at the time of connection results in an increase in the surface pressure on the seating surface. This eliminates the need for excessive tightening force, and at the same time reduces the stress concentration at the lower part of the flare (1), effectively dispersing it. This is an extremely useful tube end connection flare structure, such as being able to stably and reliably connect for a long period of time without worrying.

[Brief description of the drawings]

FIG. 1 is a partially cutaway plan view of a connection flare structure at a pipe end.

FIG. 2 is a diagram corresponding to FIG. 1 showing another embodiment.

FIG. 3 is a partially cutaway longitudinal sectional view showing a connection state of FIG. 1;

FIG. 4 is a partially cutaway longitudinal sectional view of a connection flare structure showing a conventional example in a connection state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flare 1 'Opening wall 2 Resiliently deforming wall 2' Convex part or concave part 2 "Standing part

Claims (1)

(57) [Scope of request for utility model registration] 1. A flare structure which is integrally formed with a trumpet-shaped opening at an end of a pipe to be connected, wherein an opening wall (1 ') formed by a flare (1) is formed along a peripheral wall of the opening wall. A pipe end characterized in that a waist portion is provided with an elastically deformable wall (2) comprising an annular convex portion (2 ') or a concave portion for generating an elastic force with clamping and tightening at the time of connection. Connection flare structure.