JPH0326377Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The invention is generally applicable to automobiles, various machines,
This invention relates to an improvement in the connection structure of metal pipes or hard resin pipes that are relatively small in diameter, with a pipe diameter of about 30 m/m or less, and are often installed as supply paths for oil and air in equipment, etc.

[Conventional technology]

Conventionally, as illustrated in FIG. 3, a conventional connection structure of this type includes a joint body 11 having a communication hole 12 extending through the shaft core, and a connection tube wall protruding from the front part of the joint body 11, as shown in FIG. Insert the metal seal ring member 14 in the shape of a Soroban beads, which has been assembled in advance near the end of the tube body P', and tighten the seal by screwing it onto the connecting cylinder wall with the tightening nut 13. The ring member is clamped between the outer circumferential end of the opposing communication hole 12 and the bottom wall of the tightening nut 13, and the vicinity of the thin edge portions on both front and rear sides of the ring member are bitten into the outer circumferential surface of the tube P' side. It was configured in such a way that it

[Problem that the invention attempts to solve]

However, in such a conventional connection structure, since the connecting pipe P' and the flow hole 12 need to be concentric with each other, a high degree of dimensional accuracy is required, making processing and insertion difficult. In addition, the metal seal ring 14 in the shape of a Soroban bead bites into the outer peripheral surface of the tube P′ side near the thin edge portion, resulting in thinning of the tube body, and fatigue caused by the thinning. Concentration of stress leads to deterioration of mechanical strength, and often combined with vibration during installation, cracks and breakage occur on the side of the tube P' near the biting part, resulting in deterioration of vibration resistance. Furthermore, if the tube P' is not concentric with the flow hole 12 or is tilted, there are other problems such as the inability to make a connection.

In order to extremely effectively solve the above-mentioned conventional problems, the present invention has been developed to
Insert it into the flow hole on the connecting cylinder wall side of the joint body,
As the tightening nut is tightened, the elastic seal ring is elastically pressed in the axial direction so that the inner circumferential surface of the bent hole is brought into close contact with the outer circumferential surface of the tube body, Eliminate the thinning of the tube body side due to extreme biting into the outer circumferential surface of the tube body and the concentration of fatigue stress due to this thinning, and reduce the deterioration of mechanical strength near the strong compression joint on the outer circumferential surface of the tube body side. We propose a connection structure that eliminates the worries of cracks and breakage, exhibits good vibration resistance, and allows connection even if the pipe body is not concentric with the flow hole or is tilted. The purpose is to

[Means for solving problems]

The present invention has a joint main body having a communication hole penetrating through the shaft core and a connecting cylinder wall whose outer periphery is a threaded surface protruding from the front part. A short elastic seal ring made of a rubber material, resin material, or metal spring material and having an accordion wall-like cross section, and covering the inner bent hole circumference side with an annular sealing material made of rubber material or resin material. and a tightening nut are inserted into the connecting end side of the tube body, and as the tightening nut screws into the threaded surface, an elastic seal ring is attached to the circumferential end of the hole on the connecting tube wall side. A connection structure for a small diameter tube is configured such that the tube is elastically clamped between the front surface of the tube and the bottom wall of the tightening nut, and the circumferential surface of the bent hole on the inside of the tube is tightly pressed against the outer circumferential surface of the tube body. Further, the inner peripheral side of the front surface of the circumferential end of the hole is configured as a stepped enlarged diameter opening, and a washer is interposed on the bottom wall of the tightening nut.

〔Example〕

As mentioned above, the embodiment of the present invention will be explained based on the drawings. Fig. 1 is a partially cutaway vertical cross-sectional view showing the connection structure of the small diameter pipe of the present invention, and Fig. 2 is the same as the above of another embodiment. 1 is a longitudinal cross-sectional view with a partial cutaway, and 1 is a joint body having a communication hole 2 penetrating through the shaft core and a connecting cylindrical wall 4 protruding from the front part with a threaded surface 3 on the outer periphery. , a connecting end of a tube P in which a short elastic seal ring 6 made of a rubber material or a resin material with an accordion wall-like cross section and a tightening nut 5 are assembled in advance into the communication hole 2 portion on the connecting tube wall side; As the tightening nut screws into the threaded surface 3, the elastic seal ring 6 is inserted between the front surface of the peripheral end of the hole on the connecting cylinder wall 4 side and the bottom wall of the tightening nut 5. The inner circumferential surface of the bent hole is tightly pressed against the outer circumferential surface of the tubular body P. Reference numeral 7 denotes a stepped enlarged diameter opening provided on the inner peripheral side of the front surface of the peripheral end of the hole as desired, and by protruding and clamping the elastic seal ring 6, an even stronger sealing effect is achieved. It is something that can be done. Reference numeral 8 denotes a washer provided on the bottom wall of the tightening nut 5 and having a sliding function during tightening.

In connection with the use of the metal spring material, a slightly protruding annular pressure wall is provided on at least one of the front surface of the peripheral end of the hole or the bottom wall of the tightening nut 5 to increase sealing performance. Of course, it may be configured to do so.

[Effect]

Since the present invention is configured in this way, when making a connection, the connection end side of the tube body P side in which the elastic seal ring 6 is incorporated is inserted into the flow hole 2 part of the connection cylinder wall 4 of the joint body 1. Then, by screwing and tightening the tightening nut 5 to the connecting cylinder wall 4, the elastic seal ring is elastically clamped and the inner bent hole circumferential surface is strongly pressurized and tightly fitted to the outer circumferential surface of the tube body P. Close it and connect.

[Effect of idea]

As explained above, the connection structure for small-diameter pipes according to the present invention allows the elastic seal ring 6, which has an accordion wall-like cross-section, to bend the inside of the tightening nut 5 by the clamping pressure of the elastic force accompanying the screwing and tightening of the tightening nut 5. Since the hole circumferential surface is connected to the outer circumferential surface of the tube P side under strong pressure, the structure of the arcuate circumferential surface having a resilient shape at the bending portion prevents the tube P due to biting at the strong pressure fit.
There is almost no thinning on the sides and concentration of fatigue stress due to the thinning, thus preventing deterioration of mechanical strength at the strongly compressed joint and preventing cracks caused by vibration etc. in the installed state. This is an extremely useful connection structure for small-diameter pipes, as it eliminates the fear of breakage and exhibits good vibration resistance.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway vertical cross-sectional view of a connecting structure for small diameter pipes showing one embodiment of the present invention, Fig. 2 is a partially cutaway longitudinal cross-sectional view of the same as the same according to another embodiment, and Fig. 3 is a conventional It is a partially notched vertical cross-sectional view showing an example. 1... Joint body, 2... Communication hole, 3... Thread surface, 4... Connection cylinder wall, 5... Tightening nut, 6...
...Elastic seal ring, 7... Expansion port, 8... Washer, P... Pipe body.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) The connecting cylinder of the joint body 1, which has a communication hole 2 penetrating through the shaft core and a connecting cylinder wall 4 whose outer periphery is a threaded surface protruding from the front part. A short elastic seal ring 6 and a tightening nut 5 are attached to the two parts of the wall-side communication hole, the cross section of which has an accordion wall shape, and the circumferential surface of the inner bent hole is covered with an annular sealing material. Insert the connecting end side of the tubular body P incorporating the above, and as the tightening nut tightens the elastic seal ring 6 to the threaded surface 3, the elastic seal ring 6 is attached to the circumferential end of the hole on the connecting cylinder wall 4 side. It is elastically clamped between the front surface of the part and the bottom wall of the tightening nut 5, and as a result of the clamping pressure, the circumferential surface of the bent hole on the inside thereof is strongly press-tightly fitted to the outer circumferential surface of the tube P side. A connecting structure for small diameter pipes. (2) Utility Model Registration The connection structure for small diameter pipes as set forth in claim 1, characterized in that the inner peripheral side of the front surface of the peripheral end of the hole is configured as a stepped enlarged diameter opening 7. (3) The connection structure for small diameter pipes as claimed in claim 1, characterized in that a washer 8 is interposed on the bottom wall of the tightening nut 5.