JPH089503Y2 - Pipe fitting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a pipe joint.

<Prior Art> When connecting a fiber-reinforced synthetic resin (hereinafter referred to as FRP) pipe, a pipe joint in which packing is embedded in the inner surface of the FRP joint body may be used. In order to manufacture this pipe joint, an already molded packing is inserted on a mandrel, a joint main body is formed on the outside of the mandrel by a filament winding method, and the mandrel is removed after the resin is hardened.

In this pipe joint, it is extremely important to secure the fixing strength of the packing to the FRP joint body in order to seal high internal pressure fluid. It is known to increase the adhesion strength of the packing to the joint body (Japanese Patent Publication No. 62-25914).

<Problems to be Solved> However, since the side surface of the annular convex portion is a vertical surface and the locking effect in the radial direction cannot be expected, there is a limit to the improvement of the fixing strength. In the field of interfacial bonding, it is known that the undercut groove or dovetail groove can remarkably improve the locking strength, but it is difficult to form the undercut groove in the molding of the packing. It is extremely difficult to use it to improve the fixing strength of the packing to the main body.

An object of the present invention is to provide a pipe joint in which the fixing strength of the packing to the FRP joint body can be improved substantially like the undercut groove, and the molding of the packing is easy.

<Means for Solving the Problems> A pipe joint according to the present invention is a pipe joint in which a packing is embedded in the inner surface of a fiber-reinforced synthetic resin joint body, and a number of tapered projections are formed on the outer peripheral surface of the packing. Is provided, the fiber-reinforced synthetic resin joint body is molded by the filament windowing method, and the protrusion is pressed and bent by the filament.

<Action> An undercut-shaped gap is formed just below the pushed and bent protrusion, and the resin of FRP bites into the gap, so that an effective locking action can be achieved.

<Description of Embodiments> Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view showing an embodiment of the present invention, in which an upper half portion is shown in a longitudinal section and a lower half portion is shown in a side surface.

In FIG. 1, reference numeral 1 is a packing, and as shown in FIG. 2, a large number of tapered projections 11, ... Are formed on the outer peripheral surface, and self-sealing lips 12 ,. Is molded. Reference numeral 2 is a joint body made of FRP, which is molded by the filament windowing method. At the time of this molding, the tapered projections 11, ... Are pressed and bent by the filament wound, and an undercut-shaped space is held immediately below the bent projections 11 ,.
The resin of P is eating in. In this tapered protrusion 11, the second moment of area is small toward the tip, and therefore it bends as far as the tip and is hard to bend as far as the root, so even if it is pressed down by the filament, A gap remains directly underneath, and packing 1 is FRed by biting resin into this gap.
Can be firmly embedded in the P joint body 2.

The protrusions 11, ... Formed on the outer peripheral surface of the packing are either spot-like dispersed as shown in FIG. 3A or streaks provided as shown in FIG. 3B. Good.

In the above, it is preferable that all of the protrusions 11, ... Are bent by filaments, but some of the protrusions may remain upright, usually at least 50%.
It suffices if the projection of is bent. Also, the protrusions 11, ...
Is within the limit of demolding during packing molding,
It may be tilted from the time of molding.

Usually, synthetic rubber such as styrene-butadiene rubber and chloroprene rubber can be used for the packing. The shape of the inner surface of the packing 1 is appropriately set depending on the type of pipe to be connected, fluid pressure, and the like.

The height h of the protrusion 11 is usually 5 to 10 mm, and the bid diameter or width is usually 0.2 to 0.7 h. Generally, glass fibers can be used as the fibers of the FRP material, and unsaturated polyester resin can be used as the resin. In addition, the winding angle of roving in filament winding is usually 45 to 65 degrees.

In order to manufacture the above pipe joint, packing is mounted on a mandrel that can be reduced in diameter through divided spacers, flanges are attached to both ends of the mandrel, and then resin impregnated glass roping is windowed between the flanges. By the roving windowing, the protrusions on the outer peripheral surface of the packing are pressed and bent, and the impregnated resin enters the gap immediately below the pressed and bent protrusions. FRP by filament widening method
Once the manufactured joint body is formed, the resin is cured, and this completes the manufacture of the pipe joint of the present invention.

FIG. 4 shows a connecting portion of a pipe using the pipe joint of the above-mentioned embodiment, and the pipe 3 is a composite FRP pipe (filled with resin concrete between the FRP inner pipe and the FRP outer pipe by the filament winding method). Have been used). Since the packing 1 is firmly embedded in the inner surface of the joint body 2, the pipe 3 can be smoothly inserted, and a high degree of sealing performance against internal pressure can be secured.

FIG. 5 shows another embodiment of the present invention. When the FRP pipe 20 integrally having the expanded diameter receiving port 2 is formed by the filament windowing method, the packing 1 is embedded in the inner peripheral surface of the receiving port. There are tapered protrusions on the outer peripheral surface of the packing 11, ...
Is bent by the pressing of the roving, and the FRP resin bites into the void just below the bent protrusion.

<Effect of the Invention> The pipe joint according to the present invention has the above-described configuration,
By winding the reinforcing fiber that constitutes the FRP of the P joint body, the protrusions on the outer peripheral surface of the packing are bent, and the FRP bites into the gap immediately below the bent protrusions. The fixing strength can be enhanced well by the same locking action as the undercut groove. Further, the protrusions on the outer peripheral surface of the packing may be upright before being bent, and the packing with the protrusions can be easily molded.

Therefore, according to the present invention, it is possible to provide a pipe joint in which the packing can be easily molded and the packing can be firmly embedded in the inner surface of the joint body.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention, FIG. 2 is a vertical sectional view showing a packing used in the present invention, and FIGS. 3A and 3B are outer peripheral surfaces of the packing used in the present invention. FIG. 4 is an explanatory view showing a protrusion, FIG. 4 is an explanatory view showing a pipe connecting portion using the embodiment of FIG. 1, and FIG. 5 is an explanatory view showing another embodiment of the present invention. 1 ... Packing, 11 ... Protrusion, 2 ... Joint body.

Claims (1)

[Scope of utility model registration request] 1. A pipe joint in which packing is embedded in the inner surface of a fiber-reinforced synthetic resin joint body, wherein a number of tapered projections are provided on the outer peripheral surface of the packing, and a fiber-reinforced synthetic resin joint body is provided. A pipe joint formed by a filament winding method, wherein the protrusion is pressed and bent by a filament.