JP3174703B2 - Electric fusion splicer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrofusion joint device for integrally molding a metal connection member such as a valve and a joint with an electrofusion joint made of synthetic resin.

[0002]

2. Description of the Related Art Generally, metal pipes are used for water supply, hot water supply, air conditioning, gas pipes, and the like. However, such metal pipes may cause contamination or leakage due to rust or corrosion. As an alternative, resin pipes such as polyethylene pipes have recently been used.

[0003] As a method of connecting the resin pipes, a method of bonding the contact surface between the resin pipe and the joint with an adhesive or inserting the resin pipe into an electric fusion joint composed of a resin joint having a heating element inside is used. Then, there is an electric fusion method in which the heating element is energized and heated to fuse and connect the pipe and the inner and outer surfaces of the joint (for example, Japanese Patent Application Laid-Open No. 5-87286).
No.). Since the above-mentioned method using an adhesive is difficult to apply to connection of a resin pipe having low adhesiveness such as a polyethylene pipe, an electric fusion method is generally used in many cases.

[0004] As described above, the resin pipes preferably use the electric fusion means. However, when connecting the metal pipe and the resin pipe, a joint having a relatively small nominal diameter (25 A or less) is used as a metal joint. There is known an electrofusion joint formed integrally by insert molding.

[0005]

However, in recent years, there has been an increasing demand for joints having a large nominal diameter (50 A or more), and this type of means for connecting a large-diameter metal pipe and a resin pipe, for example, cast iron Valves and joints having a large nominal diameter, which are means for branching from a metal pipe such as a metal pipe to a resin pipe such as a polyethylene pipe, have not yet been proposed for the following reasons.

[0006] The reason for this is that as the diameter of a valve or the like increases, the amount of synthetic resin injected for insert molding also increases, so that the amount of shrinkage increases, and as a result, the joint A shown in FIG. ₁ and A ₂ are W ₁ and W shown in FIG.
_Since gaps ₂ occur and cause leakage, this is currently not implemented especially for valves. 16 and FIG.
7, a metal cap constituting a body of a metal valve (nominal diameter of 50 A or more);
a is a resin joint portion, 2b is a fused portion incorporating a heating element 2c,
2d is a connector for connecting to the control.

Under the circumstances described above, there has been a strong demand for the development of connecting means for easily and surely connecting valves and joints for connecting a metal pipe having a large diameter and a resin pipe. The present inventor has developed a result of intensive research in order to solve technical problems such as warpage and strain, which significantly reduce the adhesion performance of the joined portion due to shrinkage of the resin after insert molding with a large diameter. The metal valve and metal joint with a large diameter are securely molded together with the electric fusion joint, so that metal pipes and resin pipes or resin pipes can be easily adhered to each other by simple means. It is an object of the present invention to provide an electrofusion-type splicing device which is excellent in terms of cost and economy.

[0008]

In order to achieve the above-mentioned object, the present invention provides a step-like connecting cylinder formed on a metal connecting member of a valve or a joint, and the like. A dovetail groove or a wedge portion was formed on the inner end face, and a synthetic resin electrofusion joint member incorporating a heating element was integrally formed with the connection member by insert molding. In this case, an irregular portion, a saw-tooth portion, a knurl portion, one of a number of concave portions formed continuously on the outer peripheral surface of the connection tube portion described above, or a combination thereof as appropriate, or a convex portion of the irregular portion is formed. Preferably, knurling is performed. Further, the dovetail groove or wedge formed on the outer end face of the connection cylinder is formed to have an inner diameter of the connection cylinder, while the dovetail groove or wedge formed on the inner end face of the connection cylinder is formed outside the connection cylinder. It is preferable to form it more than the diameter.

In addition, a step-shaped connecting cylinder is formed in a metal connecting member of a valve or a joint, and a tapered groove having a depth of H and a length of L is formed on an inner end surface of the connecting cylinder, and heat is generated. An electric fusion type joint member made of a synthetic resin having a built-in body is integrally formed with the above-mentioned connecting member by insert molding, and an outer end of the joint side of the joint side is inserted into the above-mentioned tapered groove to perform insert molding. I did it. In this case, an O-ring may be attached to at least one of the corner of the tapered groove and the inner corner of the inner end surface to integrally mold the joint member and the connection member, and a sheet may be formed on the end surface of the tapered groove. It is preferable that the joint member and the connection member are integrally formed by mounting.

Further, a stepped connecting cylinder portion is formed on a metal connecting member such as a valve and a joint, and a synthetic resin electric fusion type joint member having a built-in heating element is formed by insert molding with the above connecting member. A metal ring was fitted on the outer peripheral surface of the joint member externally fitted to the connection tube part, while being provided integrally.
In this case, it is preferable that the outer periphery of the metal ring fitted to the outer peripheral surface of the joint member is made uneven so that the joint member is tightened, and the above-described metal ring is attached to the outer peripheral surface of the joint member and the outer periphery of the connection member adjacent thereto. It is preferable to fit so as to straddle the surface. Furthermore, a flange is formed at the end of the metal ring on the connection member side, and this flange is locked in the outer peripheral groove of the connection member, and is formed on the outer end surface and the inner end surface of the connection tube portion of the metal connection member. Form a dovetail groove, a wedge groove or a tapered groove, or form a continuous uneven portion on the outer peripheral surface of the connection tube portion, a saw tooth portion, a knurl portion, one of a number of depressions, or appropriately combine these, Alternatively, it is preferable to apply knurls to the convex portions of the concave and convex portions.

[0011]

Since the present invention is constructed as described above, when the resin is injected during the molding, the resin in the axial direction is drawn by the dovetail groove or the wedge formed in the connecting cylinder of the metal connecting member during cooling. Is prevented, the generation of a gap between the joining surfaces can be prevented, and the strength and sealing performance can be improved.

Since the other invention is also configured as described above, when the resin enters the tapered groove and starts cooling after molding, the resin shrinks more in the radial direction, so that the metal connection cylinder is tightened. On the other hand, in the length direction, since the metal side and the resin side contract in opposite directions, the tapered surface of the tapered groove generates a strong surface pressure, increases strength and sealing performance, and also generates a gap between the joining surfaces. Absent. In this case, if an O-ring is attached to the corner of the tapered groove and the corner of the inner end face, or if a sheet is attached to the inner end side of the tapered groove, the sealing performance can be further improved.

Further, since the other invention is also configured as described above, the metal ring whose diameter is increased by increasing the temperature immediately after molding or after completion of molding is fitted, and after cooling, the joint member is tightened with the metal ring. The strength is increased and there is no gap between the joining surfaces. In this case, if the outer periphery of the metal ring is made uneven, the joint member can be further tightened with the metal ring, and the sealing performance can be improved. Further, when the flange portion of the metal ring is locked in the outer peripheral groove of the connection member, the joint member is tightened so as to approach the connection member side by contraction on the resin side, so that the strength and the sealing property are further improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the electric fusion splicing apparatus according to the present invention will be described. FIGS. 1 and 2 are partial longitudinal sectional views showing a first embodiment. In FIGS. 1 and 2, reference numeral 11 denotes a large-diameter valve, fittings, etc. formed of metal such as cast iron or another metal material. In this example, the connection member is a flanged cap that constitutes the body of a ball valve (160A) made of ductile cast iron. Have. Although not shown, this ball valve is a valve for rotatably providing a ball having a through hole inside a body to open and close a flow path.

The connecting member 11 has a stepped connecting cylindrical portion 12.
Are formed, and dovetail grooves 13 and 14 as shown in FIG. 1 are formed on the outer end face and the inner end face of the connection tubular portion 12, respectively. By setting the dovetail groove 13 side as far as possible from the inner diameter and the dovetail groove 14 side as far as possible from the outer diameter, the shrinkage of the resin is further reduced. Further, the saw-tooth portion 1 continuous with the outer peripheral surface of the connection tube portion 12 is formed.
5 is formed to improve the adhesiveness of the resin, and in addition to the example of the sawtooth portion 15, one of a continuous uneven portion, a knurl portion, and a concave portion, or a combination thereof as appropriate, or an uneven portion is formed. Knurling may be applied to the surface of the projection. These saw-tooth portions and the like prevent the connection member 11 and the joint member 16 from rotating in the twisting direction.

In the drawing, reference numeral 16 denotes a joint member formed by injecting a cross-linkable thermoplastic resin such as cross-linked polyethylene or cross-linked polypropylene into the mold in a state where the connecting member 11 is built in a not-shown die. It is. A fusion portion 17 is provided on the inner peripheral surface of the joint member 16, and the fusion portion 17 is formed of a non-crosslinkable thermoplastic resin such as polyethylene, polypropylene, polybutene, or polyvinyl chloride. It is constituted by a resistance heating wire 18 (heating element) such as a nickel wire or a nichrome wire buried inside the portion 17 so as not to be electrically short-circuited.

The resistance heating wire 18 generates heat when energized from a power supply or controller (not shown) and a connector 19 through a connection wire 20, and the heat generated by the heating wire 18 causes the fused portion 1 to be heated.
7 and the outer peripheral surface of the inserted portion of the resin pipe (not shown) are fused and fused. As the above-mentioned electric fusion joint member 16 made of synthetic resin, a commonly used one may be used, and any structure of the electric fusion joint is included and can be used. Note that it is also possible to generate heat by induction heating in which a high-frequency magnetic field is applied to the heating element from outside the joint member.

FIG. 2 shows another example of the dovetail grooves 13 and 14, in which a wedge portion 21 is formed at the outer end of the connecting tube portion 12 and a wedge portion 22 is formed at the inner end. To resist resin shrinkage.
The same effects are obtained.

In FIGS. 1 and 2, dovetail grooves 13 and 14 or wedge portions 21 and 2 are formed on the outer end surface and the inner end surface of the connecting cylinder portion 12, respectively.
When the synthetic resin is provided in the mold at the time of molding, the shrinkage in the axial direction can be prevented at the time of cooling, the generation of a gap as shown in FIG. 17 can be prevented, and the strength and sealing performance can be improved. .

FIGS. 3 to 6 are partial longitudinal sectional views showing a second embodiment. In FIG. 3, a step-like connecting cylinder 12 is provided on a metal connecting member 11 such as a valve or a joint. And a tapered groove 23 having a depth H and a length L formed on the inner end surface of the connecting cylinder portion 12. When insert molding is performed, the resin enters the tapered groove 23 and connects the joint member 16 to the connecting member 16. The enlarged diameter portion 24 is formed at the outer end on the side of
A tapered surface 25 is formed on the contact surface between the third portion 3 and the enlarged diameter portion 24.

In FIG. 3, since a tapered groove 23 having a depth H and a length L is formed on the inner end surface of the connecting cylinder 12 provided on the connecting member 11, the resin enters here at the time of molding, thereby cooling after molding. Then, the resin shrinks more in the radial direction, so that the outer peripheral surface of the connection tubular portion 12 is tightened. Also,
In the longitudinal direction, since the connecting member (metal side) 11 and the joint member (resin side) 16 contract in opposite directions, the tapered surface 2
In No. 5, a strong surface pressure is generated, strength and sealing properties are increased, and no gap is generated, so that the commercial value is also increased.

Further, as shown in FIGS. 4 and 5, at least one of the corners of the tapered groove 23 and the inner corner of the inner end face is made of a flexible material in order to enhance the sealing performance of the joint between the two. When the O-rings 26 and 27 are molded with the O-rings 26 and 27 inserted, the O-rings 26 and 27 are compressed by the resin that is press-fitted during molding, and when the resin contracts upon cooling, the O-rings 26 and 27 are restored to eliminate gaps and seal. Enhance the nature. Further, as shown in FIG. 6, a sheet 28 may be attached to the end face on the side of the tapered groove 23, and in this case, the sealing property can be improved.

As described above, it is possible to enhance the sealing property by appropriately providing a groove whose adhesive surface is strongly in contact with the contraction direction of the metal side and the resin side. Further, each of the above examples has been described using a metal material, but the same applies to other materials. At an appropriate time after the molding, the surface pressure of the tapered surface 25 can be increased by pressing the portion A in FIG. 3 inward with a roller or the like. Other configurations in FIGS. 3 and 4 are the same as those in FIG. 1 and exhibit the same functions and effects.

FIGS. 7 to 15 are partial longitudinal sectional views showing the third embodiment. In FIG. 7, immediately after the insert molding or at an appropriate time after the completion of the molding, the metal ring 29 whose diameter has been increased and the diameter thereof has been expanded is fitted to the outer peripheral surface of the joint member 16 which is externally fitted to the connecting tube portion 12, and After the ring 29 is cooled, the metal ring 29 is attached to the metal ring 29 in a state where a torsion stress is generated so that the resin is tightened (see FIG. 8). Thereby, a connecting device can be obtained in which the strength is increased and no gap is formed between the joining portions.

Further, as shown in FIG.
The outer periphery of the metal ring 29 fitted to the outer peripheral surface is made uneven to form the uneven portion 30. This means that the metal ring 29 is fitted at an appropriate time immediately after the molding as shown in FIG. 9, and then the resin is tightened by the partial mold 31 or the full circumference simultaneous mold as shown in FIG.

As shown in FIG. 12, the metal ring 29, which has been raised in temperature after molding, is fitted over the outer peripheral surface of the joint member 16 and the outer peripheral surface of the connecting member 11 adjacent thereto,
When the metal ring 29 cools, the state as shown in FIG. 13 is obtained, so that the strength and the sealing performance are improved.

Further, a flange 32 is formed at the end of the metal ring 29 on the connection member 11 side, and this flange 32 is connected to the connection member 11.
When the metal ring 29 is engaged with the outer peripheral groove 33, the temperature of the metal ring 29 is raised after molding and the fitted metal ring 29 cools down. Since the metal ring can be contracted, the metal ring contracts while tightening the resin, and the state shown in FIG. 15 is obtained. At this time,
The metal ring 29 is tightened so that the resin is brought closer to the metal connecting member 11 because the flange 32 is locked in the outer peripheral groove 33, so that the strength and the sealing performance are further improved. The other configuration is the same as the configuration in FIG. 1 and has the same function and effect.

Although the second and third embodiments are not shown, the dovetail grooves 13 and 14 or the wedge portions 21 and 22 or the saw-toothed portions, the uneven portions, the knurled portions, and the dents provided in the first embodiment are not shown. Needless to say, it can be arbitrarily implemented by appropriately combining the parts and combining a wedge groove, a tapered groove, and the like on the outer end face and the inner end face of the connection cylindrical portion 12 of the metal connection member.
Further, the connecting cylinder portion of the connecting member may be formed by insert molding so as to be embedded inside the joint member. In addition, although each said example demonstrated the example applied to the cap with the flange of a ball valve, it is not limited to this, but a butterfly valve, a gate valve, a globe valve, a check valve, a plug valve or other The present invention can be applied to a valve or a part thereof, and can be applied not only to a two-way valve but also to a three-way valve, and further to a joint and other connecting members.

[0029]

As is apparent from the above, the present invention has the following effects. When connecting a metal connecting member and a synthetic resin connecting member, even if both have a large diameter, they can be firmly connected without forming a gap in the mating surface, and the strength and sealing performance can be significantly improved. Since it can be mass-produced at low cost, it is possible to provide an economically excellent connection device. Also, since the electric fusion joint can be easily connected to the metal valve or the metal joint that branches the metal pipe and the resin pipe or between the resin pipes, even if the nominal diameter is large, the joining means can be executed without any trouble, and the joint is securely performed. It has effects such as being able to.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view showing a first embodiment of an electric fusion splicing apparatus according to the present invention.

FIG. 2 is a partial longitudinal sectional view showing another example of FIG.

FIG. 3 is a partial longitudinal sectional view showing a second embodiment of the electric fusion splicing device according to the present invention.

FIG. 4 is an enlarged detail view of a part a showing another example of FIG. 3;

FIG. 5 is an enlarged detail view of a part showing another example of FIG. 3;

FIG. 6 is an enlarged detail view of a part a showing another example of FIG. 3;

FIG. 7 is a partial longitudinal sectional view showing a third embodiment of the electric fusion splicing device according to the present invention.

FIG. 8 is a partial longitudinal sectional view showing the metal ring after cooling in FIG. 7;

FIG. 9 is a cross-sectional view of a cross section taken along line XX of FIG.

FIG. 10 is a partial longitudinal sectional view showing another example of FIG. 7;

FIG. 11 is a cross-sectional view of another example of FIG.

FIG. 12 is a partial longitudinal sectional view showing another example of FIG. 7;

13 is a partial longitudinal sectional view showing a state after the metal ring of FIG. 12 has been cooled.

FIG. 14 is a partial longitudinal sectional view showing another example of FIG. 7;

FIG. 15 is a longitudinal sectional view showing a state after the metal ring of FIG. 14 is cooled.

FIG. 16 is a partial longitudinal sectional view of an electric fusion connection structure showing a conventional example.

FIG. 17 is a partial longitudinal sectional view showing a state in which a gap is formed in a mating surface between a resin and a metal after molding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Connection member 12 Connection cylinder part 13, 14 Dovetail groove 15 Sawtooth part 16 Joint member 17 Fused part 18 Heating element 21, 22 Wedge part 23 Tapered groove 24 Large diameter part 25 Tapered surface 26, 27 O-ring 28 Sheet 29 Metal ring 32 Flange 33 Outer peripheral groove

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor, Changning Hayashi 1-209, Otashinmachi, Yao-shi, Osaka Specialty Co., Ltd. (56) References JP-U 4-136396 (JP, U) JP-U 4- 3589 (JP, U) Japanese Utility Model Application 58-144180 (JP, U) Japanese Utility Model Application 64-64289 (JP, U) Japanese Utility Model Application Hei 3-115289 (JP, U) (58) Field surveyed (Int. ⁷ , DB name) F16L 47/00-47/06 F16L 23/04 F16L 33/02 B29C 45/14 B29C 65/34 F16K 27/00

Claims (3)

(57) [Claims] 1. A stepped connecting cylinder portion is formed on a metal connecting member of a valve or a joint, and a dovetail groove or a wedge portion is formed on an outer end surface and an inner end surface of the connecting cylinder portion, and a heating element is formed. Inside
Built electrical fusion type connection apparatus characterized by being configured integrally made of synthetic resin electro fusion Chakushiki catch member by the connecting member and the insert molding. 2. The unevenness which is continuous on the outer peripheral surface of the connecting cylinder portion.
Part, sawtooth part, knurl part, one of many depressions
Are formed, or these are appropriately combined, or
The electrofusion splicing device according to claim 1 , wherein knurls are applied to the protrusions . 3. A dovetail groove formed on an outer end surface of the connection tube portion.
Or the wedge part is formed more than the inside diameter of the connection cylinder part,
Connect the dovetail groove or wedge formed on the inner end face of the connection
The electrofusion splicing device according to claim 1, wherein the electrofusion splicing device is formed to have an outer diameter that is larger than an outer diameter of the connecting cylinder .