JPS5915823Y2 - End connection structure of small diameter metal tube - Google Patents

Description

[Detailed description of the invention] This invention prevents the mechanical function of the small diameter metal connecting pipe from decreasing due to overheating of the burner when the end of the small diameter metal pipe is soldered to the metal end fitting using a burner. The purpose of this method is to connect the edge of a small-diameter metal tube to the shaft core to prevent the occurrence of cracks or breakage on the tube side near the solder weld. The front end surface of the head of the metal end fitting that has been attached is brought into contact with the rear retaining surface of the connection body, and the metal end fitting is tightened by a nut that is engaged with the rear pressure receiving surface of the head of the metal end fitting. A pipe with a diameter of 30 m that is often used as a supply pipe for refueling and air supply for automobiles or various mechanical devices, etc., which is tightened to the connection body and the end of the small diameter metal pipe is connected to it.
A metal having an end connection structure for a small diameter metal tube of about 100 yen or less, in which an escape hole is provided in the inner core on the rear side of the head of the metal end fitting between the inner core and the outer circumferential surface of the small diameter metal tube. It is characterized in that a sleeve cylinder is arranged in a row, and the end edge of the small diameter metal tube is welded to the engagement hole in the inner core of the head of the metal end fitting.

Conventionally, as the end structure of this type of small diameter metal tube, the inner surface of the engagement hole of the axial center of the metal sleeve cylinder at the rear of the metal end fitting,
It is known that the end edge of a small diameter metal tube is engaged and welded.

According to this structure, the overheating of the burner during solder welding will affect the entire surface of the solder welded part of the small diameter metal connecting pipe, resulting in a decrease in the mechanical function of the solder welded part or problems. This tends to cause cracks and breaks on the pipe side near the solder weld.

Conventionally, as a vibration-resistant narrow tube end having a brazed flange, a tubular projection having the same diameter as the through hole of the flange member is protruded from the front surface of the steel member, and the narrow diameter end is attached to the projection. Insert the tip edge of the thin tube end from the opening of the projection, and fill the gap between the flange member and the thin tube end with the burner overripe through the gap created by the opening edge of the projection and the thin tube wall in contact with the iron wire. It is known to inject molten metal to form a solder layer in the gap.

In this conventional structure, since the flange member and the steel pipe end are welded over the entire surface of their mutual engagement, the effect of reducing cracks and breakage due to burner heated solder welding can be achieved. There is a drawback that it cannot be done.

Furthermore, conventionally, as a connecting fitting for the end of a small diameter metal pipe, a cylindrical body part is integrally provided on the back of a headband-shaped metal head having a pressing surface or a seat surface on the front surface, and the metal head and the cylindrical body are A series of through-holes into which the connecting end of the thin-diameter metal tube is tightly fitted or brazed are provided in the axis of the part, and narrow straight cylindrical surfaces are provided in stages on the outer periphery of the cylindrical part. is also known.

Even in this conventional structure, the outer circumferential surface of the metal tube is tightly fitted or soldered over the entire surface up to the rear end of the through hole, so it is effective to prevent cracks and breakage caused by burner heated solder welding. There is a drawback that it cannot be played.

In contrast to these known structures, the invention of this application eliminates the drawbacks of these known structures. A metal sleeve cylinder with an escape hole interposed between it and the outer peripheral surface of the small diameter metal tube is connected, and the end of the small diameter metal tube is inserted into the retaining hole of the inner core of the head of the metal end fitting. Since the edges are welded, the pressure is lower than the pressure-receiving engagement surface of the metal end fitting, which is the fulcrum of vibration.
The welded part (fixed part of the metal connecting pipe) is on the inside, reducing vibration fatigue of the metal connecting pipe, and the escape hole and the small diameter metal connecting pipe do not come into contact, preventing breakage from that part. This is extremely useful since there is no metal fatigue of the metal connecting pipe due to overheating of the burner during welding, and cracking and breakage can be prevented.

The invention of this application will now be explained with reference to the drawings.

In the embodiment shown in FIGS. 1 to 3, an engagement hole 1 that engages the edge of a small diameter metal tube 5 is provided through the axis of the head, and an escape hole that communicates with the engagement hole 1. A metal end fitting 4 is constructed by protruding a sleeve cylinder 3 in which a sleeve cylinder 3 is provided with a step-through structure 2 facing backward;
An end edge 6 of a small-diameter metal connecting pipe 5 is engaged and welded 7 into an engagement hole 1 penetrated through the axis of the head of the metal end fitting 4, and the front edge of the metal end fitting 4 An engagement surface 12 on the inner rear side of the joint body 11, which has a through hole 10 in its axis that communicates with the through hole 9 in the axis of the small diameter metal connecting tube 5.
The outer pair of the cylindrical protruding walls 3 are fitted with a pressure receiving engagement surface 13 protruding from the root, and the shaft core 15 is loosely fitted onto the outer periphery 14 of the sleeve cylinder 3 and tightened with a nut. 16 is screwed onto the joint main body 11 to integrally connect and tighten the small diameter metal connecting pipe 5 and the metal end fitting 4 to the joint main body 11.

In the drawings, reference numeral 17 indicates a small gap within the escape hole 2.

In the embodiment shown in FIG. 4, the contact end surface 8 provided on the front edge of the metal end fitting 4 is formed into a convex arc surface 8'' to prevent mechanical function from decreasing due to overheating during welding work, etc. This makes it possible to prevent cracks and breaks from occurring on the tube side near the solder weld due to defects.

Fig. 5 shows a conventional structure in which the end edge 6' of the small diameter metal tube 5' is engaged with the inner surface of the engagement hole in the axis of the metal sleeve cylinder 3' at the rear of the metal end fitting 4'. The joint is welded 7'.

[Brief explanation of the drawing]

Figure 1 is a side view of one embodiment of this invention, Figure 2 is Figure 1 I.
-I line sectional view, Figure 3 is figure 2 II -II line sectional view,
FIG. 4 shows a longitudinal sectional view of another embodiment, and FIG. 5 shows a longitudinal sectional view of a conventional structure. In the drawings, the same reference numerals indicate the same or equivalent parts, 1 is the engagement hole, 2 is the escape hole, 3 is the sleeve cylinder, 4 is the metal end fitting, 5 is the small diameter metal connecting pipe, and 6 is the edge thereof. , 7 is the engagement welding part, 8 is the opposing end surface, 9° 10 is the through hole, 11 is the joint body, 12 is the engagement surface, 13 is the pressure receiving engagement surface, 14 is the outer periphery of the sleeve cylinder 3, 15 is the The shaft center free hole, 16 indicates a tightening nut.

Claims (1)

[Scope of utility model registration request] The front end surface of the head of the metal end fitting, which has the edge of the thin metal tube attached to the shaft core, is brought into contact with the rear retaining surface of the connection body, and the front end surface of the head of the metal end fitting is engaged with the rear pressure receiving surface of the head of the metal end fitting. In the case where the metal end fitting is tightened to the connection body and the end of the small diameter metal tube is connected, the tightening is performed by tightening the metal end fitting to the inner core on the back side of the head of the metal end fitting. A metal sleeve cylinder with an escape hole interposed between it and the outer peripheral surface of the small diameter metal tube is connected, and the end of the small diameter metal tube is inserted into the engagement hole of the inner core of the head of the metal end fitting. An end connection structure for small diameter metal tubes characterized by welded edges.