JPS6340711Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The invention is generally used in automobiles, various machines, equipment, etc. as a supply path for refueling, air supply, corrosive fluids, etc. Pipe diameter 30 with a tube made of resin or rubber material tightly fitted inside.
Relatively small diameter of about m/m or less, and wall thickness of 2m/m
The present invention relates to an improvement in a connecting support structure consisting of a double flare that is integrally provided at the tube end connection portion of a thin-walled metal tube with a thickness of less than m.

[Conventional technology]

Conventionally, this type of double-flare tube end connection support structure includes, for example, a tube end connection portion of a metal tube 11 having a tube 12 made of a resin material or a rubber material inside, as illustrated in FIG. Then, the inner tip of the inner peripheral wall 15, whose front surface is the seat surface 14 and which is bent next to the outer peripheral wall 13 which forms a double flare and opens outward, is simply bent to form the end of the inclined surface with the opening inclined. The end portion of the tube 12 was sandwiched between the outer circumferential wall 13 and the inner circumferential wall 15. In FIG. 2, 16 is the opening below the head and neck of the double flare.

[Problem that the invention attempts to solve]

However, in such a conventional tube end connection and support structure, since the inner tip of the bent inner circumferential wall 15 is simply an open end with an inclined surface, there is , the clamping function is generally insufficient due to the spring pack (rebound) that occurs after machining, and when machining an inclined surface due to the impact pressure on the inside of the shaft core by the punch in the second step,
Due to the inward escape of the tube 12 side end, the vicinity of the end cannot be sufficiently sandwiched between the outer peripheral wall 13 and the inner peripheral wall 15, and it is often the case that the tube 12 side end is in a state where it cannot be sufficiently sandwiched between the outer peripheral wall 13 and the inner peripheral wall 15. The internal fluid flows from the clamping part to the metal tube 11.
This has caused problems such as detour penetration into the inner circumferential surface of the side, causing rust and other problems.

In order to extremely effectively solve the above-mentioned conventional problems, the present invention aims to extend the inner tip of the inner circumferential wall formed with the double flare as a pipe end connecting support structure from the lower part of the opening head and neck to the lower part of the neck. By forming a thin cylindrical wall that extends to a position that extends to the adjacent cylindrical wall and press-fits the opposing wall portions of the tube, the cylindrical wall structure at the inner tip allows the tip to be processed after processing. This eliminates the worry of spring back caused by the metal tube, and the structure that presses against the wall of the tube provides a sufficient clamping function, preventing bypass penetration from the clamping part to the inner peripheral surface of the metal tube in the installed state. The object of the present invention is to propose a pipe end connection and support structure that can reliably prevent rusting and other problems from occurring.

[Means to solve the problem]

The present invention utilizes a coaxial front surface of an inner circumferential wall that is bent to connect with an outer circumferential wall that is coaxially opened outward at the tube end connection part of a metal tube in which a tube made of a resin material or a rubber material is tightly fitted. is the abutting seat surface for the mating seat part, and in a double flare structure formed by sandwiching and interposing the end of the tube between the outer circumferential wall and the inner circumferential wall, the front surface is the abutting seat surface. The inner tip of the inner circumferential wall is extended from the lower part of the opening of the head and neck to the cylindrical tube wall near the neck, and is formed into a thin cylindrical wall that presses and presses the opposing wall of the tube. The gist of this invention is a tube end connection and support structure for a small diameter thin-walled metal tube.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings. Fig. 1 is a partially cutaway cross-sectional view of the tube end connection and support structure for a small diameter thin-walled metal pipe of the present invention,
Reference numeral 1 denotes a metal tube, in which a tube 2 made of a resin material or a rubber material is tightly fitted inside by pulling together, etc., and a tube 2 is integrally connected coaxially outward to the tube end connection part of the metal tube. A seating surface 4 whose front surface, which is bent along with the opening outer peripheral wall 3, is brought into contact with a mating seat (not shown).
and an inner circumferential wall 5 to form a double flare as a connection and locking structure. The end of the tube 2 is sandwiched between the outer circumferential wall 3 and the inner circumferential wall 5 forming the double flare, and the inner tip of the inner circumferential wall 5 has its front surface as the abutting seat surface 4. extending from the opened lower part of the head and neck to a position extending to the circular tube wall 8 near the lower neck,
Moreover, the opposing wall portions of the tubes 2 are formed into a thin cylindrical wall 7 that presses into tight contact with each other. In addition, 9 in FIG. 1 is a tightening nut.

[Effect]

Since the present invention is configured in this manner, the inner end portion on the inner circumferential wall 5 side formed with a double flare is connected to the circular pipe wall 8 near the neck portion from the open lower head neck portion 6. Since the structure has a thin cylindrical wall 7 that presses and presses the wall portions of the tubes 2 which are extended to the opposite position, the spring at the tip portion after processing is formed by the thin cylindrical wall structure at the inner tip portion. In addition, the pressure-fitting structure of the tube 2 against the wall of the tube 2 provides a sufficient clamping function, and the internal pressure caused by the punch to the inside of the shaft during the second process is eliminated. Even when the peripheral wall 5 is bent, the tube 2 side end does not escape inward and is sufficiently sandwiched between the outer peripheral wall 3 and the inner peripheral wall 5.

[Effect of idea]

As explained above, the tube end connection and support structure according to the present invention can be easily installed in the installed state due to the structure of the thin cylindrical wall 7 at the inner tip on the inner circumferential wall 5 side, and due to the sufficient clamping function of the cylindrical wall. This is an extremely useful method that can reliably prevent corrosive internal fluids from bypassing and penetrating into the inner peripheral surface of the metal tube 1, thereby preventing rusting and other problems from occurring on the inner peripheral surface. This is a tube end connection support structure for small diameter thin-walled metal tubes.

[Brief explanation of drawings]

FIG. 1 is a partially cut-away sectional view of a tube end connection and support structure for a small diameter thin-walled metal tube showing an embodiment of the present invention, and FIG. 2 is a partially cut-away sectional view showing a conventional example. . 2...Tube, 4...Abutting seat surface, 5...Inner peripheral wall, 6...Below the head and neck, 7...Thin cylindrical wall, 8...
circular tube wall.

Claims (1)

[Scope of utility model registration request] A mating seat is the front surface of the inner circumferential wall that is bent in continuation with the outer circumferential wall that is coaxially opened to the outside and is integrally provided at the tube end connection part of the metal tube in which a tube made of resin material or rubber material is tightly fitted and inscribed. In a double flare structure formed by sandwiching the end of the tube between the outer circumferential wall and the inner circumferential wall, the inner circumferential wall has a front surface as the abutting seat surface 4. 5
A thin cylindrical wall 7 whose inner tip extends from the opened lower part of the head and neck to a position reaching the circular tube wall 8 near the lower neck, and presses and presses the opposing wall parts of the tube 2. A pipe end connection structure for a small diameter thin-walled metal pipe, characterized in that the structure is constructed of: