JPS582957Y2 - tube socket - Google Patents

Description

[Detailed description of the invention] The present invention relates to a pipe socket in which an FRP bell part is formed at the end of a headless pipe, and particularly relates to a structure of a pipe socket with increased flexibility in the socket part. It is.

If you want to use a pipe that cannot be formed into a socket shape through secondary processing, such as a thermosetting resin pipe, an FRP pipe, or a composite pipe made by combining FRP material and resin mortar material, as a pipe socket, A method is adopted in which a bell portion constituting a socket is formed at the end of the head tube.

When forming the bell part, a core mold for socket molding is attached to the end of the headless tube, and FRP material is covered from the outer periphery of the end of the headless tube to the outer periphery of the core mold. It is said that a method of curing, forming a bell portion, and joining the bell portion to the end of the headless tube all at once is advantageous.

The FRP bell part formed in this way has considerable flexibility, and when applied to buried pipes, etc., bending force is applied to the socket part due to uneven ground, etc. Even if it is stiff, it has the function of absorbing bending force due to the flexibility of the socket part, that is, the bell part, so it is considered to be preferable in terms of increasing the durability of the joint part.

However, when forming an FRP bell portion at the end of a headless tube, there are the following difficulties, and the flexibility of the FRP bell portion is often not fully exhibited.

That is, FIG. 1 is a vertical cross-sectional view of a main part illustrating a known pipe socket, in which an FRP bell part 2 is formed at the end of a headless pipe 1, and the outer peripheral part of the tip of the headless pipe 1 is Equivalent to Atsushi hOFRP
A layer of material is formed.

As a result, at the tip of the headless tube 1, the wall thickness of the bell section and the wall thickness ho of the headless tube 1 are added to make the thickness even smaller, which increases the rigidity of this part and reduces its flexibility. sexuality is markedly reduced.

As a result, the flexibility with respect to bending force, which is a characteristic of the FRP bell portion, is reduced, and damage may occur from the base portion 2a of the socket.

In particular, when using a relatively rigid headless pipe such as a pipe with a built-in mortar layer, the rigidity at the back of the socket increases rapidly due to the addition of the rigidity of the headless pipe 1 itself.
The damage to the socket base 2a becomes even more significant.

Therefore, when forming an FRP bell part at the end of a headless pipe to form a pipe socket, it is possible to suppress the tendency of local thickening at the joint part as much as possible, and to dramatically increase the rigidity. It is necessary to take measures to prevent this and maximize the flexibility of the FRP bell part.

The present invention was developed with attention to the above circumstances, and the purpose is to create a pipe socket that maximizes the flexibility of the FRP bevel part and exhibits outstanding durability. This is what we are trying to provide.

The configuration of the present invention that has achieved these objectives is that the outer periphery of the tip of the headless tube is equipped with an FRP Berber fitting that has a large diameter part at the tip that is larger than the inner diameter of the headless tube. In a pipe socket formed with a mouth, the FRP Berber head is formed so as to circumferentially cover all or part of the outer circumferential surface of the distal end and the most distal end surface of the pipe, and the FRP Berber head has no head. The outer diameter surface from the outer circumferential surface of the tube tip end to the large diameter portion and the inner diameter surface from the tip end position of the headless tube to the large diameter portion are each tapered surfaces, and the wall thickness of the tapered portion of the FRP bellbell portion of,
The main idea is that the headless tube is gradually thinned from the most extreme position to the large diameter section, and prevents a local and sudden decrease in flexibility at the joint with the FRP Berber head tube. As a result, flexibility with respect to bending force can be greatly improved.

The configuration and effects of the present invention will be explained below with reference to the drawings, which are examples. However, the present invention is not limited to the following, and may be implemented with appropriate modifications in keeping with the spirit of the above and later explanations. All of these are included within the technical scope of the present invention.

FIG. 2 is a longitudinal cross-sectional view of the main part illustrating the tube socket according to the present invention, showing the outer circumferential surface of the distal end (hereinafter abbreviated as "the outer circumference of the end") and the most distal end surface (hereinafter "the end surface") of the headless tube 1. The bell portion 2 is shown firmly joined using the joint surface (abbreviated as "").

In the illustrated example, the thickness hl of the FRP layer formed on the outer periphery of the end of the headless tube 1 is made as thin as possible h1<h, and the thickness gradually becomes thinner toward the center of the headless tube 1 (toward the right side of the drawing). Form it so that it becomes

The lack of strength of the bell part due to the thinning of the FRP material layer on the outer periphery of the end of the headless tube 1 is reinforced by forming an FRP material layer on the end surface 1ast of the headless tube 1. A tapered part 3 having an inclination angle θ is formed at the inner depth of the bell part 2, and the FRP material layer is formed so that it gradually becomes thinner as it goes from the end face 1a position to the opening side of the bell part 2 (left side in the drawing). do.

In this way, the bell portion 2 is firmly joined to the outer periphery of the end of the headless tube 1 and the end surface 1a.

Also, as is clear from the diagram, the overall wall thickness of the pipe socket of the present invention is maximum at the end face 1a of the headless pipe 1, but the thickness of the FRP material layer is thicker on the left and right of this part as a border. Since the thickness is made to gradually become thinner, there is no possibility that the rigidity changes abruptly at the inner part 2a of the socket as in the known example shown in FIG.

Moreover, the FRP material layer (thickness hx) formed on the outer periphery of the end surface 1a portion and the FRP material layer formed on the right side thereof are
Since it is significantly thinner than the example shown in FIG. 1, the increase in rigidity of the entire end portion of the headless tube 1 is also significantly suppressed.

Although the FRP material layer is slightly thicker immediately to the left of the end surface 1a of the headless tube 1, this portion can exhibit sufficient flexibility due to the characteristics of the FRP material itself.

In any case, in the present invention, the FRP material layer at the end of the headless tube is formed as thin as possible, so the flexibility over the entire socket is increased, and the FRP material layer is gradually thinned at the front and back of the end surface 1a. By doing so, local damage accidents that tend to occur in the case of Fig. 1 can be suppressed as much as possible.

In addition, referring to the example in FIG. 2, the joining length L between the headless pipe 1 and the bell part 2, and the inclination angle θ of the tapered part 3 formed on the inner surface of the bell part 2 are determined.
The wall thickness of the large diameter portion of the bell portion 2 is not particularly limited, and should be set appropriately depending on the strength and flexibility required for the pipe socket. In their experiments, it was confirmed that setting according to the following formula is the most advantageous and general.

That is, when the inner diameter of the headless tube 1 is d1, the wall thickness is t1, the inner diameter of the large diameter portion of the bell portion 2 is D1, and the length of the tapered portion 3 is t, the joining length L is set to be approximately 15 times the factor of d. The necessary and sufficient bonding force can be obtained, d. The wall thickness T is -Xo, 00 when set to 70. The strength balance can be maintained most easily, and the inclination angle θ of the tapered portion 3-d is set to θf-tan. ' It was confirmed that the formation work of the bell portion 2, which will be described later, is simplified.

These values indicate the preferred values when the composite pipe with a built-in mortar layer is a headless pipe, and the suitable values may differ slightly depending on the material of the headless pipe 1 or the type of FRP material. Of course it will come.

For example, the pipe socket of the present invention is constructed as described above,
The key is to make the FRP layer gradually thicker from the opening of the bell part 2 to the pipe end joint, so that the overall flexibility of the pipe socket is increased and the rigidity is locally and rapidly increased. It is distinctive in that it eliminates the negative parts.

Therefore, as long as such characteristics can be effectively exhibited, the shape of the joint is not limited to the example shown in FIG. or the end surface 1a of the headless tube 1 as shown in FIG.
Of course, it is also possible to leave a part of the part and join it, and it goes without saying that these changes are included in the technical scope of the present invention.

Next, an example of a method for forming a pipe socket according to the present invention will be briefly explained with reference to the drawings.

FIG. 5 is a vertical cross-sectional view of the main part illustrating the pipe socket forming method, in which a bell part 2 is formed on the outer periphery of the end of the headless pipe 1 using a core mold 5 for socket forming.
The figure shows the case where a pipe is formed to form a pipe socket.

The core mold 5 is provided with a fitting part 5a, a tapered part 5b, a large diameter part molded part 5c, etc., and is configured to be rotated by an appropriate drive source.

Then, the tip opening of the headless tube 1 is fitted into the fitting part 5a,
It is fixed so as to rotate together with the core mold 5.

In this case, a pre-manufactured headless tube 1 is used, and the outer periphery of its tip is cut in advance with a grinder, etc., and the protective film (for example, non-woven fabric, etc.) on the outermost periphery is removed, or unevenness is formed. Alternatively, a method may be adopted in which the bell portion is formed subsequent to the molding of the main pipe 1.

Next, the core mold 5 is rotated to begin the winding molding work of the bell portion 2, but before that, a release agent is applied to the outer periphery of the core mold 5 (or wrapped) in order to facilitate demolding of the core mold 5. Furthermore, it is preferable to cover the inner circumferential surface of the bell portion 2 with a non-woven fabric to give it a smooth finish.

After that, from the outer periphery of the end of the headless tube 1 to the tip surface 1a and the core mold 5
The FRP material may be in any form, such as resin-impregnated long fibers, band-shaped glass cloth, chopped strand mats, etc. Various known FRP materials can be wound into a single layer or multiple layers.

In the example shown in Figure 5, the hoop winding layer (circumferential direction)
2b and longitudinal winding layer (parallel to the axis) 2c
These are combined to form a multi-layer structure, so that an even stronger bell section 2 is formed.

In order to simplify the winding work at the stepped portion between the distal end surface 1a of the headless tube 1 and the Taber molded part 5b, in the illustrated example, winding is first performed to a predetermined thickness from the distal end surface 1a to the outer periphery of the core mold 5. Then, 75 pieces of steel are wound around the outer circumference of the end of the headless tube 1.

The hoop winding layer 2b and the vertical winding layer 2c are preferably set so that the weight ratio of the former to the latter is approximately 3:1 in order to maximize physical strength.

Moreover, it is preferable that the thickness of the longitudinal winding layer 2c be kept to less than 2 wn; if the thickness exceeds 2 wn, delamination may occur, which is not preferable.

After repeating the winding operation in this manner until the bell portion 2 reaches a predetermined thickness, the outermost periphery is covered with nonwoven fabric to give it a beautiful finish, and this is hardened by heat treatment to form a pipe socket. It turns out.

The pipe socket of the present invention is manufactured, for example, as described above,
The manufacturing method itself does not limit the present invention, and various known FRP bell molding methods or improvements thereof may be freely applied.

The present invention is constructed as described above, and the rigidity at the pipe socket is made as small as possible, and the rigidity gradually changes from the socket to the end of the headless pipe to prevent local concentration of bending force. As a result, the strength and durability against bending force of the pipe socket can be greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the main part illustrating a conventional pipe socket, FIG. 2 is a longitudinal cross-sectional view of the main part illustrating the pipe socket according to the present invention, and FIG.
FIG. 4 is a longitudinal cross-sectional view of a main part showing another embodiment, and FIG. 5 is a longitudinal cross-sectional view of a main part showing an example of manufacturing a pipe socket according to the present invention. 1... Headless pipe, 2... Bell part, 3...
...Tapered portion, 4...Tapered surface, 5...
...Core mold for socket molding, 1a... Tip surface of headless tube, 2b... Hoop winding layer, 2c
・・・・・・Vertical winding layer.

Claims (1)

[Scope of utility model registration request] In a tube socket formed by wrapping an FRP bell part having a large diameter part with an inner diameter larger than the inner diameter of the headless tube around the outer periphery of the tip of the headless tube to form a socket, The bell part is formed to circumferentially cover all or part of the outer circumferential surface and the most distal end surface of the headless tube, and the FRP bell section extends from the outer circumferential surface of the tip end of the headless tube to the large diameter part. The outer diameter surface extending from the tip of the headless tube to the large diameter portion is tapered, and the wall thickness of the tapered portion in the FRP bell section is set to a large diameter from the tip of the headless tube to the large diameter portion. A pipe socket characterized by being gradually thinner toward the diameter.