JPS5935329B2 - Molding method of pipe socket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a pipe socket, and more particularly, a bell part is formed by winding a resin-impregnated fiber material around the outer periphery of the end of a headless pipe to form a pipe socket. It is about the method.

The headless open end (insertion part) of pipes that are relatively difficult to perform secondary molding or that cannot be subjected to secondary processing, such as thermosetting resin pipes, FRP pipes, composite pipes, etc. If you wish to use it as a socket, a method of forming a bell part on the headless end and using it as a socket may be considered.

This type of method includes joining a pre-formed bell part to the end of the headless pipe, and placing a bell part molding core at the end of the headless pipe and starting from the outer periphery of the end of the headless pipe. Methods are known in which a resin-impregnated fiber material is roped and wound around the outer periphery of the core, a fiber mat is narrowed between these ropes, or silica sand is rolled in. The latter method is said to be preferable in that it is possible to form the bell portion and join it to the end portion of the headless tube in one step. In particular, when FRP pipes or composite pipes are used as headless pipes, the bell portion is formed using the latter roping winding method in most cases. By the way, the roping winding method is a method as shown in FIG. 1, which is a partially sectional perspective view, and FIG. 2, which is a front view with the upper half cut away. At the same time, a metal fitting 3 is placed on the outer circumference of the headless tube 2 at a suitable position, and a resin-impregnated fiber material 4 is roped and wound from the outer circumference of the end of the headless tube to the outer circumference of the core 1. In this way, a bell portion 5 is formed and serves as a pipe socket. In this case, the joint between the outer periphery of the headless tube 2 and the bell part 5 may be bonded using the adhesive force of the resin contained in the resin-impregnated fiber material 4, but usually the joint is made of epoxy resin or the like. A method is employed in which adhesive 6 is applied and then adhesively fixed. By the way, when a pipe constructed using such a pipe socket is subjected to bending force or shearing force due to earth pressure, pressure from passing vehicles, etc., these external forces are most likely to be concentrated at the connection part, especially at the bell part. 5 and the headless pipe 2. In the conventional pipe socket as described above, since the bell part 5 and the headless pipe 2 are fixed with adhesive, external force cannot be applied to the connection part. Since the stress cannot be absorbed, the state of stress concentration at the connection portion will continue for a long period of time. As a result, the adhesive surface between the bell portion 5 and the headless tube 2 may peel off, or the bell portion 5 may be deformed or damaged, resulting in a loss of watertightness. In particular, when the bell portion 5 is formed by the roping winding method, the bell portion 5 itself has considerable flexibility. The peeling phenomenon of the adhesive surface when joined to the head tube 2 tends to become even more remarkable, and if the rigidity becomes excessively higher than that of the bell part 5, the peeling phenomenon will occur at the joint between the two as described above. As a result, the overall quality of the pipe socket was not necessarily good due to the lack of strength on the adhesive surface as described above, and the bell part was not able to effectively utilize its excellent flexibility, durability, and other properties. The current situation is that this is not the case. The present invention has been made in view of the above-mentioned circumstances, and its purpose is to prevent headless pipes from being damaged when forming a bell portion at the end of the headless pipe using the roping winding method to form a pipe socket. A pipe holder that provides excellent flexibility and adhesion to the adhesive surface between the pipe and the bell part, and prevents the adhesive surface from easily peeling off and losing watertightness even when external force is applied to the connection part. Excellent flexibility of the bell part obtained by the roping winding method, when trying to provide a mouth.
The purpose is to provide a pipe socket that can maximize its characteristics such as durability.

The pipe socket forming method of the present invention that achieves this objective is as follows:
The gist is that by interposing a soft or elastic material between the headless pipe and the bell part, excellent flexibility and watertightness can be imparted to the adhesive surface. The structure is that a bell molding core is placed at the tip of a headless tube, and a resin-impregnated fiber material is wound from the outer periphery of the end of the headless tube to the outer periphery of the core to form a tube socket. A soft material or an elastic material is bonded to the outer periphery of the end of the headless tube, and the resin-impregnated fiber material is wound around and tightened around the soft material or elastic material from the outer periphery to form a bell portion. In the present invention, when forming a bell portion by winding a resin-impregnated fiber material around the tip of the headless tube, a soft material or an elastic material is placed around the outer periphery of the tip of the headless tube. Then, the resin-impregnated fiber material is tightly wound around the outer periphery of this soft material or elastic material to form a bell portion, and the entire material is hardened.

Therefore, a soft or elastic material (hereinafter sometimes referred to as soft elastic material) is interposed at the connection between the headless pipe and the bell part, but the soft elastic material is made of resin-impregnated fibers during the bell part molding process. Since it is tightened from the outer periphery by the material (i.e. the main body of the bell part), the connection part has high adhesion and exhibits excellent watertightness, and the soft elastic material can deform appropriately when external force is applied to the connection part. Since it has soft elasticity, the joint as a whole has excellent flexibility. Thus, the pipe socket obtained by the present invention has appropriate flexibility and excellent watertightness at the same time, and can maximize the various characteristics of the bell section obtained by the roping winding method. The configuration and effects of the present invention will be explained below based on the drawings which are examples, but the drawings are only for illustrating typical ones.
It is of course possible to make various design changes in keeping with the spirit of the above and later explanations, and all of these are included within the technical scope of the present invention. Figures 3 and 4 illustrate the molding method of the present invention. In the explanatory drawings, FIG. 3 is a schematic vertical sectional view, and FIG. 4 is a sectional view of the main part of the bell portion, showing only the upper half.

When forming a pipe socket by the molding method shown in the figure, first, the open end of the headless pipe 2 is surface-treated as necessary, and then a soft elastic material 7 is applied to the surface with an appropriate adhesive 6. This headless tube 2 is held between the bell portion molding core 1 and the tailstock member 8. In this case, fittings 3 and 9 are placed at appropriate positions on the outer periphery of the headless tube 2 and the outer periphery of the base of the bell forming core 1 as desired in order to regulate the end surface of the bell portion 5 to be wound and formed. be done. Next, the molding core 1 and the tailstock member 8 are rotated by an appropriate rotation drive source (not shown), and the resin-impregnated fiber material is wound from the outer periphery of the soft elastic material 7 while rotating the headless tube 2. do.
In this case, the soft elastic material 7 is wound while applying a predetermined tension so that it is tightened by the resin-impregnated fiber material. The bell portion 5 is formed by winding a resin-impregnated fiber material of a predetermined thickness from the outer periphery of the soft elastic material 7 to the outer periphery of the molding core 1. Therefore, after the bell portion is heated and hardened in this state, the molding core 1 is removed to the left in the drawing, and a tube socket is obtained. In the present invention, the bell portion 5 is formed by tightening the soft elastic material 7 joined to the outer periphery of the headless tube 2 with a resin-impregnated fiber material, and is thermally hardened in the tightened state. The adhesion of the joint with the head pipe 2 is excellent. Moreover, since the joint has flexibility due to the presence of the soft elastic material 7, even if external force is concentrated on the joint, the resulting stress concentration will be concentrated only on the soft elastic material 7. It is dispersed and absorbed, and the phenomenon of peeling of the joint is also eliminated. As is clear from the above explanation, in the present invention, the headless tube 2
A soft elastic material 7 is joined to the outer periphery of the end of the soft elastic material 7.
The characteristic is that the bell part 5 is formed in a state in which the bell part 5 is tightened, but if the soft elastic material 7 is further joined so as to extend to the end surface 2a of the headless pipe 2 as shown in the figure, the obtained pipe holder is This reduces the impact force and pressing force at the tip of the inlet tube when the inlet tube is inserted into the mouth, resulting in more favorable results. Moreover, if the soft bullet material 7 is made to extend to the end surface 2a of the headless tube 2,
This is extremely advantageous since it also prevents slippage when the headless tube 2 is held between the core 1 and the tailstock member 8 and rotated. In this case, the soft elastic material 7 and the end surface 2a are firmly adhesively fixed by the clamping force between the core 1 and the tailing member 8. Moreover, the soft elastic material 7 is connected to the joint end (second
It also has the effect of making it possible to properly mold 10) in the figure, and by the way, if the soft elastic material 7 is not used, there will be a gap between the core 1 and the end surface 2a of the headless tube 2. As mentioned above, the soft bullet material 7 used in the present invention includes soft materials and elastic materials, and all the materials conventionally used as packing materials are soft bullets that can be used. The material 7 can be tightened between the headless pipe 2 and the bell part 5 to exhibit excellent adhesion and watertightness, and can be made of any suitable material as long as it can impart appropriate flexibility to the connection part. There are no limitations at all, and various elastic and soft materials such as rubber, asbestos, and linen can be used. The thickness and width of these soft bullet materials 7 must be selected appropriately depending on the size of the pipe socket to be molded and the type of soft bullet material 7, and cannot be uniformly determined, but most commonly The thickness is approximately 1 to 5 mm, and the width is approximately 50 to 200 steps. Furthermore, it is of course recommended as a preferable means to subject the inner and outer surfaces of these soft elastic materials 7 to appropriate surface treatment as desired to enhance the adhesion with the headless tube 2 and the bell portion 5. In addition, the adhesive used to bond these to the outer periphery of the headless tube 2 may be appropriately selected so that it does not violate these conditions depending on the type of soft bullet material and the material of the headless tube 2. Adhesives such as epoxy resin, polyester resin, and phenol resin are used.
In this case, in order to increase the adhesion force of the soft elastic material 7, it is effective in the present invention to roughen the outer periphery of the end of the headless tube 2 with a grinder or the like to increase the adhesion area. In order to further increase the tightening force, a method is adopted in which the bell portion 5 is formed by tightening the soft elastic material 7 from the outer periphery before the adhesive hardens, and then the adhesive is hardened at the same time as the bell portion 5 hardens. In the present invention, the resin-impregnated fiber material constituting the bell portion is most commonly polyester resin-impregnated glass fiber, but in addition, natural fibers such as hemp, vinylon, polyamide, carbon fiber, etc. Examples include synthetic fibers or metal fibers impregnated with a suitable resin, or a combination of glass fibers and other fibers.

Methods for winding these fiber materials include a method of continuously winding a continuous single fiber, a method of winding a large number of fiber groups bundled in the width direction, or a method of winding a large number of fibers bundled in the width direction, or a method of winding not only the circumferential direction but also the axial direction. In order to reinforce the strength of the fibers, it is possible to use a fiber cloth with a blind weave, or to wind short fibers for axial reinforcement together with the circumferential fibers. The pipe socket forming method of the present invention is configured as described above, for example, but the gist is that the soft elastic material 7 is joined to the outer periphery of the end of the headless pipe 2,
The bell portion 5 is formed by winding the resin-impregnated fiber material while tightening the soft elastic material 7, thereby obtaining a joint having excellent adhesion and watertightness, and providing flexibility to the joint. The feature is that it eliminates the phenomenon of peeling when the joint is subjected to external force.

Therefore, the material of the headless tube 2, the material and form of the resin-impregnated fiber material, the type of adhesive, etc. are not limited in any way as long as the above gist and characteristics can be effectively exhibited, and various changes as described above can be made. be. Furthermore, the configuration of the molding device is not limited to that shown in FIGS. 3 and 4, and can be modified as long as it can perform roping winding by gripping the headless tube 2 and rotating the bell molding core 1 at the same time. It is also possible to adopt this mechanism. Furthermore, it is also possible to fix the headless tube 2 and the bell portion molding core 1 and to form the bell portion by winding and covering the resin-impregnated fiber material, and any of these degree of design changes are within the scope of the present invention. Since the present invention is constructed as described above, when a bell portion is formed at the tip of a headless tube to obtain a tube socket, the adhesiveness and watertightness of the connection portion are improved. In addition, the joint part exhibits excellent flexibility due to the presence of soft elastic material, so even if external force is applied to the pipe socket and stress is concentrated at the joint part, Since these stresses are relaxed or absorbed by the soft elastic material, the situation where the bonded portion peels off is eliminated.

In this way, the pipe socket obtained by the present invention can effectively exhibit the excellent flexibility and durability of the bell portion reinforced with the fiber material through the intervention of the soft elastic material. It is something that

[Brief explanation of the drawing]

The drawings are for explaining the present invention, and Figures 1 and 2 illustrate a known pipe socket forming method, with Figure 1 being a partially sectional perspective view, and Figure 2 being a partially sectional side view of the main part. It is. Figures 3 and 4 are explanatory diagrams illustrating the method of molding the pipe socket according to the present invention, with Figure 3 being a vertical sectional view of the main part, and Figure 4 showing only the upper half of the socket (bell part). This is what is shown on the screen. 1...
・・Bell part molding core, 2・・・・ Headless tube, 3, 9・
...Metal fitting, 5...Bell part, 6...
...Adhesive, 7...Soft material (or elastic material), 8
...Tailstock member.

Claims (1)

[Claims] 1. When forming a pipe socket by placing a bell molding core at the tip of the headless pipe and winding a resin-impregnated fiber material from the outer periphery of the end of the headless pipe to the outer periphery of the core, A soft material or an elastic material is bonded to the outer periphery of the end of the head pipe, and the resin-impregnated fiber material is wound around and tightened around the soft material or elastic material from the outer periphery to form a bell portion. A method of forming pipe sockets.