JPS6339502Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a safety pipe joint, and is particularly preferred as a pipe joint for hydraulic piping systems, although it is not limited thereto. More specifically, the present invention provides a sealing ring having an inner and outer tapered conical tip and having two or more cutting edges of different diameters on the inner surface when the connection is completed, and a connecting member having an inner conical surface and a threaded cap. The present invention relates to a safety pipe joint that uses a sealing ring to connect pipes and is inserted between shaped pressure members. When the pressure member or nut is tightened axially along the fixed end of the pipe, the sealing ring is moved forward and at the same time cuts into the wall of the pipe with its cutting edge to press against the wall material.

[Conventional technology and problems]

Known sealing rings of this type have two or more cutting edges of different diameters in succession.
The rear inner surface that is continuous with the cutting edge and located rearward in the direction of movement has a conical inner surface that is continuous with the cylindrical inner surface of the rear part of the sealing ring, which cylindrical inner surface is connected to the outer surface of the pipe when the connection is completed. It is located plastically relative to the stopper, so that no sense of stopping can be obtained by the assembler. Therefore, it is extremely difficult for the assembly operator to tighten the connection accurately, which may result in threading of the threaded connection.

[Purpose of invention]

The aim of the present invention is to eliminate these shortcomings and maintain the required strength factor, while exhibiting an active increase in cutting forces upon completion of the connection, and further damping vibrations to prevent breakage in the area of the sealing connection due to mechanical vibrations. Or it relates to a safety pipe joint with a sealing ring that prevents cracking.

[Structure of the idea]

In the safety pipe joint according to the present invention, the diameter of the second cutting edge of the sealing ring is larger than the diameter of the first cutting edge, and the thickness of the sealing ring immediately behind the limiting edge is equal to or smaller than the inner conical surface of the connecting member. The cylindrical inner surface of the sealing ring has a diameter that is substantially half the difference between the maximum diameter and the outer diameter of the pipe to be connected by the safety fitting, and that gradually increases at a position opposite the limiting edge. a convex curved surface having a convex surface connected thereto, and the limiting edge being substantially perpendicular to the cylindrical inner surface and located proximate the largest diameter portion of the inner conical surface in the connected state of the pipe; It is characterized by not substantially cutting into the outer surface of the pipe.

[Effect of idea]

According to the invention, the limiting edge becomes effective at the final stage of assembly. By connecting a convex curved surface with an increased diameter to the cylindrical inner surface of the sealing ring, as shown in the example, this surface ensures a soft but firm press against the pipe surface, so that no mechanical vibrations occur At times, vibrations are sufficiently damped to prevent breakage or breakage of the sealing connection area.

Since the ring diameter of the second cutting edge of the sealing ring is larger than the corresponding diameter of the first cutting edge, a positive increase in the cutting force is produced due to the action of the limiting edge, which results in a sharp increase in the cutting force. The thickness of the sealing ring immediately after the front surface of the limiting rim corresponds to the maximum diameter of the cone of the connecting member and half the outside diameter of the pipe, so that in the connected state of the pipe the limiting rim is in the vicinity of the largest diameter part of the connecting member. As the limiting edge approaches the connecting member, the cutting resistance increases rapidly, allowing the assembly worker to reliably feel the stopping sensation and tighten the connecting part accurately. . In addition, by making the inner diameter of the unthreaded part of the pressure member in the shape of a screw cap larger than the outside diameter of the pipe surface, and making the unthreaded part of the pressure member into a cylindrical or funnel-shaped cut-out part, the pipe can be tightened when the connection is completed. This allows for a significant vibration damping effect.

Therefore, according to the present invention, it is possible to reliably construct a pipe joint with sufficient tightening force without breaking the pipe joint, and it becomes possible to use the pipe joint in a piping system where the pressure inside the pipe is higher than that in the past.

〔Example〕

The invention will be more easily understood from the following description of illustrative embodiments of the invention and with reference to the accompanying drawings.

As shown in the drawings, the connecting member 1 has an inner conical surface 2 for mounting a sealing ring 3, and the sealing ring 3 is pressed against the pipe 4. The pipe ends to be connected are seated on the contact surface 5 of the connecting member 1. When the connection is completed, the pressure member 6 in the shape of a screwed cap is tightened, so that its front conical surface 18 abuts against the conical slope 12 having a cone angle of 90° of the sealing ring 3, and the sealing ring 3 is connected to the pipe 4 on the left side in the figure. Press in the axial direction.

The sealing ring 3 comprises two different and sequentially arranged first and second cutting edges 7, 8;
In its initial state shown in FIG. 1, the first cutting edge 7 located at the front end of the sealing ring 3 has a smaller internal diameter than the second cutting edge 8 that follows it; Cut into the surface of pipe 4. There is a clear relationship between the depth of cut and the distance between the two cutting edges 7, 8.

A limiting edge 11 is provided after the cutting edge 8, and the front end of the limiting edge 11 is oriented perpendicularly to the surface of the pipe 4. The sealing ring 3 has a cylindrical inner surface 14 which has a convex curved surface 10 with a diameter 9 increasing successively at the end of the sealing ring 3.
, forming a trumpet-shaped outlet 13. As shown in FIG. 2, the sealing ring 3 may be slightly bent due to the axial pressing force by the pressure member 6, creating a small gap 19, but when the convex curved surface 10 is bent, the pipe 4 of the sealing ring 3 Does not impair adhesion.

Due to the axial movement of the sealing ring 3 and the resulting diameter reduction of the inner conical surface 2, the cutting edge 7 penetrates into the surface of the pipe 4 and displaces some of the pipe material 15.

Following the cutting edge 7, a cutting edge 8 is provided with a predetermined dimension. At this stage of assembly, the limiting edge 11 is connected to the connecting member 1.
creates a sealing effect between the inner inner surface 2 of and the pipe 4, so that the sealing ring 3 can no longer be moved in the axial direction. That is, at this time, the limiting edge 11 presses against the outer surface of the pipe 4, and the outer conical surface of the sealing ring 3 presses against the inner conical surface 2 of the connecting member 1. In this state, the limiting edge 11
is located in the region of the maximum diameter 16 of the conical surface 2 creating a strong pressure in the pipe 4. That is, the thickness of the sealing ring immediately after the limiting edge 11 is half the difference between the maximum diameter 16 and the outer diameter of the pipe 4, and the limiting edge 11 does not substantially cut into the outer surface of the pipe 4. . Since the limiting edge 11 presents a clearly observable resistance to the assembly operator during the final stage of the assembly operation, further tightening of the pressure element 6 is only possible using very strong forces.
The assembly operator will therefore receive clear instructions when the connection is complete. The geometry of the limiting edge 11 has a convex curved surface and an outlet 1 of the sealing ring 3.
The trumpet-shaped exit at 3 remains unchanged. The pipe 4 is therefore pressed softly and strongly into a sheath onto the conical slope 12 with a cone angle of 90 DEG and under the pressure of the sealing ring 3 and the screw cap 6.

It is preferable that the unthreaded portion 20 at the rear end of the pressure member 6 has a funnel-shaped cutout (solid line) or a cylindrical cutout (broken line) shape with a diameter larger than the outer diameter of the pipe 4, as shown in the figure. With such a shape, the surface of the pipe 4 can be inclined as shown by angle 17 in FIG. For this reason, mechanical vibrations are damped in this way and breakage of the connection is avoided in the area of the sealing ring.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of the upper half of the pipe connection with a sealing ring according to the present invention in its initial state;
The figure is a longitudinal sectional view of the embodiment of FIG. 1 when the connection is complete. 1... Connecting member, 2... Inner conical surface, 3... Sealing ring, 4... Pipe, 5... Collision surface,
6... Pressure member (screwed cap), 7, 8...
... Cutting edge, 10 ... Convex conical surface, 11 ... Limiting edge, 12 ... Conical slope, 14 ... Cylindrical inner surface.

Claims (1)

[Scope of utility model registration request] A safety pipe fitting comprising a sealing ring for use in pipe connections, the sealing ring having a tapered conical tip having an inner surface and an outer surface, the inner surface having at least two annular rings of different diameters. said sealing ring having a cutting edge is inserted between a coupling member and a pressure member having an abutment surface abutting the end of the pipe and an inner conical surface connecting to a cylindrical surface, said pressure member being connected to a threaded cap. and has a cylindrical or funnel-shaped recess in the unthreaded part, and the sealing ring has a limiting edge on its inner surface behind the conical tip, and a circular cutout behind the limiting edge. In the safety pipe joint having a columnar inner surface, the diameter of the second cutting edge of the sealing ring is larger than the diameter of the first cutting edge, and the thickness of the sealing ring 3 immediately behind the limiting edge 11 is greater than that of the connecting member. 1 and the outer diameter of the pipe 4 connected by the safety pipe joint, and the cylindrical inner surface of the sealing ring has the limiting edge. A convex curved surface having a successively increasing diameter is connected to the opposite position of the pipe 4, and the limiting edge is substantially perpendicular to the cylindrical inner surface and in the connected state of the pipe 4 is connected to the inner conical surface. 2. A safety pipe joint characterized in that it is located near the maximum diameter portion of pipe 4 and does not substantially cut into the outer surface of pipe 4.