JP3456687B2 - Fitting for soft synthetic resin pipe - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint used for a soft synthetic resin pipe such as a water pipe polyethylene pipe.

[0002]

2. Description of the Related Art Conventionally, when connecting a polyethylene pipe and a device such as a valve when constructing a water supply pipe,
Since direct connection between the two is not possible, a flanged polyethylene short pipe is normally used for connection. This short polyethylene pipe with a flange is a short polyethylene pipe to which one end is integrally fixed in advance with a metal flange by factory production. And the connection construction of this, first, the end of the piped polyethylene pipe and the end on the polyethylene side of the short pipe with a flange are connected by an electrothermal fusion method, and then the flange is used to Connect to the device.

[0003]

However, in the method using the short pipe with a flange, since the pipes are fused and connected,
When working in a bad environment such as during rainfall, it is easy for construction defects to occur. In particular, since waterworks are carried out in an excavated place, muddy water or the like is often applied to the connection points, which hinders fusion splicing, which easily causes connection failures, resulting in poor construction reliability.

In view of the above points, the present invention provides a joint for a soft synthetic resin pipe using a mechanical connection system and having high construction reliability. Further, the present invention is to provide a joint for a soft synthetic resin pipe which is easy to construct and has high connection strength.

[0005]

The technical means of the soft synthetic resin pipe joint of the present invention comprises a pressing flange and an inner sleeve, and the inner surface of the tube inserting portion of the pressing flange and the outer surface of the inner sleeve have a reinforced joint shape. Or
The inner edge of the step on the inner surface of the presser flange
Projecting annular have a small protrusion is formed on, Rutotomoni is enlarged by fitting an inner sleeve on the inner surface of the inserted pipe end in the pressing flange, the ends of the inner sleeve is a small protrusion
Is to enclose and support the pipe end firmly.

It is preferable that the inner surface of the pressing flange is a corrugated surface. Also, the inner sleeve has a hole,
And the holes should be staggered .

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a joint according to the present invention will be described based on Examples of the drawings. The joint of the present invention comprises a pressing flange 1 and an inner sleeve 2, and FIG. 1 shows a state in which the joint is connected to a polyethylene pipe A for water supply.
The inner surface of the pressing flange 1 at the tube insertion portion has a reinforced connection shape. That is, in the embodiment, the uneven surface 3 is formed, and the tube wall of the polyethylene tube A is embedded in the uneven surface. The concavo-convex shape is free and may be corrugated or saw-tooth. However, in the case of a waveform, there is an advantage that the bite does not break. 4 is an elastic ring (O-ring) for stopping water, which is fitted into a groove at the center of the uneven surface 3.

After the inner sleeve 2 is fitted into the inner surface of the polyethylene pipe A, it is expanded and deformed. As a result, the polyethylene pipe A swells outward and bites into the uneven surface 3 as shown in detail in FIG. Further, the wall surface of the inner sleeve 2 has a reinforced joint shape. That is, in the embodiment, a plurality of holes 5 are formed on the wall surface. This hole 5 facilitates deformation when the sleeve diameter is expanded, and
After expanding the diameter, it has a function of making the inner surface of the polyethylene pipe A bite into the hole 5 to strengthen the retaining function. In the example,
The sleeve has a diameter of 91 mm, a length of 65 mm, and a wall thickness of 1.5.
It is made of stainless steel having a diameter of 15 mm and is provided with a total of 18 holes 5 having a diameter of 15 mm as shown in the drawing. The holes 5 are arranged in two rows with nine holes in one row and arranged in a staggered pattern. The result of testing in this example shows that the force required for expanding the diameter is 1/2 that of the non-perforated one.
In addition to the above, the holes were arranged in a zigzag pattern, so that the strength of the sleeve was not significantly reduced and the polyethylene pipe was sufficiently bited.

Reference numeral 6 denotes a step portion provided on the inner surface of the pressing flange 1, which serves as a stopper when the polyethylene pipe A is inserted. In addition, an annular small protrusion 7 protruding inward is formed at the end edge of the step portion 6, and the end portion of the sleeve 2 whose diameter has been expanded surrounds the small protrusion 7. Therefore, the holding force of the sleeve 2 is increased, and the sleeve 2 does not easily come out.

Next, the connection procedure will be described. FIG. 3 shows a state before connection. An elastic ring 4 for waterproofing, for example, an O-ring is previously fitted to the inner surface of the pressing flange 1. However, the ring 4 is not indispensable and can be used without the ring. Next, the end of the polyethylene pipe A is inserted into the holding flange 1. On this occasion,
Insert the tube A until the end face collides with the step 6. At this point, the diameter of the pipe A is not expanded, and the diameter of the pipe A is equal to or smaller than the diameter of the uneven surface 3, so that the pipe A can be easily inserted. Then, the inner sleeve 2 is inserted inside the tube A. Also in this case, since the sleeve 2 is not expanded, it can be easily inserted.

After setting in this way, the jack 10 is inserted into the inner sleeve 2 as shown in FIG. The jack 10 has a split expander 11 and a conical wedge 12.
When the oil is fed from the manual hydraulic pump 14 to the cylinder 13, the conical wedge 12 is pulled in the axial direction, and accordingly, the split expander 11 is pushed outward and the inner sleeve 2 of the inner sleeve 2 is pushed. Expanding force is applied to the inner surface.
The inner sleeve 2 has a hole 5 on its wall surface and is easily expanded and deformed. Therefore, when the expanding force of the jack 10 is applied, the inner sleeve 2 easily expands outward. Note that FIG. 5 shows the state before the diameter expansion and FIG. 6 shows the state after the diameter expansion.

When the inner sleeve 2 is expanded,
Along with this, since the polyethylene pipe A is also a soft material, its diameter is easily expanded and deformed, and the outer wall of the pipe A bites into the uneven surface 3 as shown in the figure. At the same time, the inner wall of the pipe A bites into the hole 5 of the inner sleeve 2. Further, as shown in FIG. 5, a ring-shaped groove 15 is formed on the outer surface of the split expander 11, and the position of the groove 15 and the position of the small ridge 7 coincide with each other. At the same time, the end of the sleeve 2 is deformed so as to wrap the small protrusion 7.

When the above diameter expansion work is completed, the jack 1
Remove 0. This completes the connection procedure. In the connected state, the polyethylene pipe A strongly digs into the concave-convex surface 3 of the pressing flange 1, so that it is possible to obtain a sufficient waterproofing property without an O-ring, and also to have a sufficient fixing and holding force for easy removal. Absent. Further, since the polyethylene pipe A bites into the hole 5 of the inner sleeve 2 and the sleeve end encloses the small protrusion 7, the sleeve 2 is completely prevented from coming out.

The present invention is not limited to the above embodiments, but can be freely modified within the scope of the claims. In particular, the detailed shape of the pressing flange 1, the kind of the joint strengthening shape on the inner surface of the tube insertion portion, and the shape of the uneven surface 3 are arbitrary. Further, the shape of the joint strengthening applied to the wall surface of the inner sleeve 2 is also free, and it is possible to form knurls or screw-like small irregularities on the outer surface of the inner sleeve 2 instead of the holes 5 of the embodiment. Even when the holes 5 are provided, the number of
The shape, formation position, etc. are free.

[0015]

EFFECTS OF THE INVENTION The joint of the present invention has a high joint strength because the pipe end of the soft synthetic resin pipe is strongly sandwiched and firmly fixed by the pressing flange and the inner sleeve, so that it is strong against earthquakes. that the tensile force is get out of the tube even if the action is not the name. Also, expand the inner sleeve
So that the end will wrap around the small protrusion of the presser flange.
Therefore, the inner sleeve has a strong holding force, and
The inner sleeve does not come out carelessly. Furthermore,
In the present invention, since the connection is achieved by a complete mechanical method, not by the fusion method, the construction reliability is high and the construction failure does not occur even in the work under bad environment. In addition, the joint of the present invention has a practical advantage that the work at the time of connection is simple and the work efficiency is high, and moreover, it can be provided at a lower cost than the conventional short pipe with a flange.

According to the second aspect of the present invention, the inner surface of the pressing flange has an uneven surface, so that the pipe end bites into the uneven surface when sandwiched, and the connection strength is further enhanced.

According to the third aspect of the present invention, since the inner surface of the pressing flange has a corrugated uneven surface, the pipe is not easily bited, and there is no breakage at the biting portion, which is safe for long-term use. Is.

According to a fourth aspect of the present invention, the inner sleeve has a hole formed in the wall surface thereof, and when the inner sleeve is sandwiched, the pipe end bites into the hole, so that the inner sleeve has a strong position holding force. It's not easy to get out.

According to the fifth aspect of the present invention, since the holes of the inner sleeve are arranged in a zigzag manner, the strength of the sleeve is not significantly reduced due to the perforation, and the diameter of the sleeve is easily expanded, so that the joint has both workability and strength. Can be obtained.

[0020]

[Brief description of drawings]

FIG. 1 is a half sectional view of a joint of the present invention in a connected state.

FIG. 2 is an enlarged cross-sectional view of a main part.

FIG. 3 is a half sectional view before connection.

FIG. 4 is a cross-sectional view showing a diameter expansion work state.

FIG. 5 is an enlarged cross-sectional view of the main part of the initial stage of the diameter expansion work.

FIG. 6 is an enlarged cross-sectional view of the essential parts at the final stage of the diameter expansion work.

[Explanation of symbols]

1 Presser flange 2 Inner sleeve 3 uneven surface 4 O-ring 5 holes 6 steps 7 small ridges 10 jacks 11 Expander 12 Conical wedge 13 cylinders 14 Hydraulic pump 15 annular groove

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Claims (5)

(57) [Claims] 1. A presser flange and an inner sleeve, wherein the inner surface of the tube insertion portion of the presser flange and the outer surface of the inner sleeve have a strengthened joint shape , and
Projected inward at the edge of the step provided on the inner surface of the flange
Annular have a small protrusion is formed, wrapped <br/> of diameter fitted to the inner sleeve to the inner surface of the inserted pipe end in the pressing flange so Rutotomoni, the end of the inner sleeve is a small protrusion Included
A joint for soft synthetic resin pipes that firmly joins and supports the pipe ends. 2. The joint for a soft synthetic resin pipe according to claim 1, wherein an uneven surface 3 is formed on the inner surface of the pipe insertion portion of the holding flange 1. 3. The joint for a soft synthetic resin pipe according to claim 2, wherein the uneven surface 3 of the pressing flange is corrugated. 4. A plurality of holes 5 in the wall surface of the inner sleeve 2.
The joint for soft synthetic resin pipe according to claim 1, wherein the joint is formed. 5. The soft synthetic resin pipe joint according to claim 4, wherein the holes 5 of the inner sleeve are formed in a zigzag shape.