JPH09273680A - Insulating joint for water supply equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent contact corrosion of metal of different kind, by securing a bush to a water supply equipment connection side of a metal-made joint main unit through an insulating member, and forming this bush by placing a turn lock means engaged with the joint main unit in an outer side and providing an internal thread connected to a supply water equipment in an inner side. SOLUTION: In a port B in a water supply equipment connection side opposite to a port A connected to a pipe of a joint main unit 10 of a malleable cast iron-made pipe joint, a ceramic-made or metal-made bush 30 is fixed by an electric insulation bonding agent. Here, from a side of the part B of the joint main unit 10, by a metal-made lock member 40 secured through the electric insulation bonding agent, the bush 30 is locked. In order to seal between the joint main unit 10 and the bush 30, an O ring groove 11 is provided in the joint main unit 10, an O ring 12 is mounted. In the bush 30, an internal thread 30a is provided inside an end part in a side of the port B, a copper alloy-made supply water equipment is screwed thereto. In this way, between the unit and the supply water equipment is electrically insulated, contact corrosion of metal of different kind is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating joint for a water supply device that electrically insulates a connection between a pipe and a water supply device.

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional joint for water supply equipment. This is one in which an elbow type joint body 1 is formed of a malleable cast iron casting, and the inner surface of the elbow type joint body 1 is covered with an inner surface lining layer 2 by synthetic resin injection molding. Water is supplied to the female thread 3 at one end of the joint body 1. The male thread of the instrument is connected, and the female thread 4 at the other end is connected to the male thread of the inner surface of the pipe of the pipe. In addition, as another conventional technique, actual fairness 6-4
There is a water supply fitting joint shown in FIG. 5 disclosed in Japanese Patent No. 154 publication. This is an insulating joint for a water faucet device having an internal thread on the inner peripheral surface. A copper alloy bush 5 is screwed into the inner peripheral surface at one end, and an electrical insulating layer 6 and an adhesive layer 7 are attached to the external thread 5a on the outer surface of the bush. It is provided. The state of the insulating adhesive portion of this screw is shown in FIG.

In this prior art, the joint body 1 and a water supply device made of a copper alloy of a different metal are screwed to a copper alloy bush 5 connected to the joint body 1, and the bush 5 and the joint body 1 are connected to each other by the bush 5. It is electrically insulated by the resin (electrical insulation layer 6) coated on the male screw 5a, and the joint body 1 and the water supply equipment or the pipe and the water supply equipment are in an insulated state, so that electrolytic corrosion due to contact of dissimilar metals does not occur. It was An external thread 5a made of a copper alloy bush 5 is screwed onto the female thread 3 on the side of the joint body 1 that is connected to the water supply device, and is made of synthetic resin to cover the inner surface of the central portion of the joint body 1. The lining layer 2 and the bush 5 are also continuously covered and adhered by the adhesive at the time of screwing the bush through the adhesive layer.

[0004]

Normally, the water supply equipment is made of a copper alloy, and is a metal different from the steel pipe for piping and the joint body made of malleable cast iron. When these dissimilar metals come into contact with each other for a long period of time via an electrolytic solution such as tap water, galvanic cells are formed due to the potential difference between the metals, and a significant corrosion current flows due to the battery action, and the potential is low with respect to the copper alloy. Joints made of base metal such as steel and cast iron and the steel pipe side rapidly cause corrosion of dissimilar metals, leading to a leak accident.

The former prior art shown in FIG. 4 has the above-mentioned problems because there is no means for insulating the water supply equipment from the joint body 1. Further, the external thread of the water supply device is not always screwed and connected until it is in close contact with the inner surface lining layer 2 at the back of the internal thread 3 of the joint body 1, and the internal thread 3 is contacted with circulating water. For this reason, there is a problem that the screw 3 corrodes from the circulating water to generate red water in the water supply system.

In the latter prior art shown in FIG. 5, the female thread 3 of the joint body 1 and the male thread 5a of the copper alloy bush 5 are used.
Is electrically insulated and bonded through the electric insulating layer 6 and the adhesive layer 7 and has a certain screw connection strength,
If the water supply device is screwed into the female screw 5b of the copper alloy bush 5 with an excessive tightening torque, the adhesive layer 7 will be destroyed, and the electrical insulating layer 6 will be destroyed, and the electrical insulating performance will not be maintained.

Further, when the pipe is exposed to a harsh cold / hot water heat cycle in which hot water and cold water repeatedly flow, the adhesive layer 7 is deteriorated, the torque resistance performance, that is, the screw connection strength is lowered, and the water supply device is temporarily tightened. Conversely, when the water supply device is unscrewed for reasons such as alignment, the insulating agent layer 7
When the bushes 5 are broken and the bush 5 rotates, there is a problem that the electrical insulation performance and the sealing performance cannot be maintained. The present invention solves the above problems, electrically insulates the water supply equipment from causing corrosion of dissimilar metal contact, and shuts the inner surface of the joint including the connection portion with the pipe from the circulating water to obtain the red water. An object of the present invention is to provide an insulating joint for water supply equipment that does not generate water.

[0008]

SUMMARY OF THE INVENTION A gist of the present invention is a joint for connecting a pipe and a water supply device, in which a bush is fixedly connected to a joint body water supply device connection side made of metal via an electric insulating member, The bush has an anti-rotation means that engages with the joint body on the outside and a female screw that connects with the water faucet device on the inside, and locks the bush with the joint body by a locking member. An outer peripheral surface of the bush,
An electrically insulating collar is sandwiched between the inner peripheral surfaces of the joint body, and the bush and the joint body and the locking member are electrically insulated by the insulating layer having the configuration. It is an insulating joint for appliances. The bush may be a material having both electric insulation and heat resistance, such as ceramics. In this case, the electrically insulating collar can be omitted. Further, as the bush, it is desirable to use a metal having substantially the same potential as that of the water supply equipment to be connected. Further, it is desirable that the bush be inserted into the joint body via a seal member.

In the above, the locking member is a nut with an external thread, and has an internal thread on the water supply equipment connection side of the joint body, and the external thread and the internal thread are screwed together to lock the bush. It is an insulating joint for water supply equipment characterized by performing.
Further, in the above, the locking member has an inner thread with a cap nut, and an outer thread is provided on a side of the fitting body where the water supply device is connected. The inner thread and the outer thread are screwed and coupled, and the bush is engaged. It is an insulating joint for water supply equipment, which is characterized by stopping.
In the above, the locking member has an annular protrusion, the water supply device connection side of the joint body is fitted and coupled in the annular protrusion,
The bush may be locked. In the above, an electrically insulating collar may be inserted between the outer peripheral surface of the bush, the inner peripheral surface of the joint body, and the inner peripheral surface of the locking member. Further, in the above, the inner peripheral surface of the joint body excluding the threaded portion on the pipe side is covered with a synthetic resin lining layer, and extends from this lining layer to the female thread side for connecting to the pipe and covers the inner peripheral surface of the connection pipe. It is good also as an insulated joint for water supply equipment, characterized in that the joint main body is provided with a shaped portion, and the joint main body is blocked from circulating water by the lining layer and the bush.

[0010]

Since the present invention has the above-described structure, the pipe is connected to the joint body, and the joint body and the water supply device are connected via the bush and the locking member. The bush is made of ceramic or a metal having substantially the same potential as the water supply device, while the locking member is made of a metal having substantially the same potential as the joint body. Further, it is electrically insulated by an electric insulating member provided between the outer peripheral surface of the bush and the inner peripheral surface of the joint body. Further, the bushing is provided with a rotation stopping means that engages with the joint body, so that the torque resistance performance is improved.

Since a seal member is mounted between the bush and the joint body, there is no fear of back leakage that causes the internal circulating water to leak between the joint body and the bush. Further, the inner surface of the joint body is covered with a lining layer made of synthetic resin, and the inner surface of the joint body can be continuous with the tubular portion from the inner surface of the connected pipe. Between the lining layer and the electrically insulating bush, the extension of the bush also overlaps with each other and is hermetically sealed so that both are continuously covered. For this reason, the inner surface of the joint body is shielded from the internal circulating water from the inner surface of the pipe to the water supply device, so that red water is not generated.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1, 2 and 3 are (a) and (b), respectively, a left side view and a sectional view of an insulating joint for a water faucet showing an embodiment of the present invention. Reference numeral 10 denotes a joint body, which is usually a threaded pipe joint made of malleable cast iron.
A ceramic or metal bush 30 is inserted by an electrically insulating adhesive into an opening B on the side (connection of the water supply device) opposite to the opening A connected to the piping of the joint body 10 and fixed in an insulated state. Further, the metal bushing 30 is locked by the metal locking member 40 which is fixedly connected with the electrically insulating adhesive from the mouth B side of the joint body 10. That is, since the metal locking member 40 and the metal bush 30 form a portion 50 that overlaps each other in the circumferential direction, not only the chemical bonding by the adhesive but also the axial direction by the physical pressing of the metal locking member 40. The bush 30 is attached to the joint body 1 by the retaining action to the
It never goes off. In order to ensure a tight seal between the joint body 10 and the bush 30, an O-ring groove 11 is provided in the joint body 10 to provide an O-ring 12 as a seal member.
Attach. Furthermore, if a double seal structure having two O-ring grooves 11 is provided, the reliability of airtightness is improved. In addition to the O-ring, a V packing, a lip packing, or the like may be used as the seal member. The sealing member may be made of a silicone-based or other sealing agent, a paste-like sealing agent, or a synthetic resin-based adhesive in combination to maintain the fixing and airtightness to the joint body.

A female screw 30a is provided inside the other end of the bush 30.
Is provided, and a water supply device made of a copper alloy is screwed into the female screw 30a. When the bush 30 is made of metal, the material of the metal bush 30 usually has substantially the same potential as that of the water supply equipment so that the water supply equipment and the metal bush 30 do not cause electrolytic corrosion due to contact of different metals. A copper alloy is used.
On the other hand, in order to prevent electrolytic corrosion due to contact between dissimilar metals between the joint body 10 and the metallic locking member 40, the material of the metallic locking member 40 usually has substantially the same potential as the joint body 10. Use mild steel or malleable cast iron.

When the water supply device is screwed into the female screw 30a of the bush 30, a twisting torque is naturally applied to the bush 30 and the bush 30 tends to rotate. However, in order to prevent this rotation, only the chemical adhesive force of the adhesive is used. Instead, as a rotation stopping means, a hexagonal recessed hole portion 10a is formed in the joint body 10.
Correspondingly, a hexagonal convex portion 30b having a size slightly smaller than the concave hole portion 10a is provided on the outer side of the bush 30, that is, the outer peripheral portion or a part of the outer peripheral portion. That is, the hexagonal concave portion 10a and the hexagonal convex portion 30b mesh with each other, and the rotation of the bush 30 can be physically prevented. The shape of the concave hole portion 10a of the joint body 10 and the convex portion 30b of the bush 30 which are fitted with each other as rotation stopping means is a polygonal shape other than a hexagonal shape or a two-sided width shape having two surfaces with respect to a circle or A spline shape in which a large number of grooves are cut with respect to a circle or a serration shape in which the grooves are formed into a triangular shape may be used (not shown).

In order to realize the above-mentioned insulation state, in the case of a metal bush, the outer peripheral surface thereof, that is, the portion contacting the joint body 10 including the hexagonal convex portion 30b and the O-ring 12 are provided.
The portion contacting with or the portion contacting with the metal locking member 40 is coated with resin. Alternatively, the joint body 10
Resin may be coated on the inner peripheral surface of the metal and the inner peripheral surface of the metal locking member 40, or the outer peripheral surface of the metal bush 30 and the inner peripheral surface of the joint body 10 and the metal locking member 40.
The resin may be coated on the entire inner peripheral surface of the.

Next, a synthetic resin is injection-molded on the inner surface of the joint body 10 to cover the inner surface of the lining pipe connected to the pipe connection screw 10d side, and the joint body integrally with the tubular portion 20. A lining layer 21 is formed so as to cover the inner surface of substantially the central portion of 10 except for the connection screw 10d and to be fitted with the metal bush 30.

The metal locking member 40 shown in FIGS. 1 (a) and 1 (b) is an externally threaded nut having an external thread 40a on its outer circumference, and an internal thread 10b is provided at the mouth B of the joint body 10 on the water supply equipment connection side. And has the outer screw 40a and the inner screw 10b screwed together to lock the metal bush 30. Next, FIG.
The metal locking member 40 shown in (a) and (b) is a cap nut having an inner thread 40b on the inner circumference, and has an outer thread 10c at the mouth B of the joint body 10 on the water supply equipment connection side, and an inner thread. Four
0b and the outer screw 10c are screwed together to lock the metal bush 30. As yet another example, FIG.
The metal locking member 40 shown in (b) and (b) has a hexagonal recessed hole portion 10a and an annular protrusion 40c that fit into the hexagonal convex portion 30b of the bush 30 on the inner peripheral portion thereof.
The inner diameter of 0c is set to be slightly larger than the outer diameter of the mouth B of the joint body 10 on the water supply equipment connection side, the mouth B is inserted into the annular protrusion 40c, and the end of the annular protrusion 40c is plastically deformed. The locking member 40 is fitted and coupled to the joint body 10. Alternatively, the inner diameter of the annular protrusion 40c may be formed to be slightly smaller than the outer diameter of the mouth B, and the mouth B may be directly press-fit into the annular protrusion 40c for caulking.

In the case of a metal bush, the above-mentioned resin coating can ensure the electric insulation, but in order to obtain more reliable electric insulation, the outer surface of the metal bush 30 and the inner peripheral surface of the joint body 10 are Metal locking member 40
An electrically insulating collar 60 is inserted between the collar 60 and the inner peripheral surface. For the material of the collar 60, thermoplastic engineering plastic (engineering plastic) is used for water piping, and ceramic, thermoplastic engineering plastic, or thermosetting engineering plastic is used for hot water hot water piping. Examples of thermoplastic engineering plastics excellent in heat resistance and strength include polyphenylene oxide, polyetherimide, polyether sulfone, polysulfone, polyphenylene sulfide, and examples of thermosetting engineering plastics are phenol. Resin, epoxy resin, etc. are available.

[0019]

As described above, the insulating joint for a water supply device of the present invention is bonded even when the water supply device is screwed into the bush with excessive tightening torque or when the pipe is exposed to a severe cold and hot water heat cycle. Sufficient strength due to the chemical connection strength of the chemical agent and the physical torque resistance performance of the bush rotation stopping means via the electric insulation collar does not destroy the insulation layer and, in turn, ensures highly reliable electricity. Insulation performance can be maintained. Furthermore, there is no corrosion of the joint body and piping due to contact with dissimilar metals, and the steel ground of the joint body and piping does not come into contact with the internal circulating water, so corrosion and red water do not occur.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention,
(A) is a left side view and (b) is a sectional view.

FIG. 2 is an explanatory view showing another embodiment of the present invention,
(A) is a left side view and (b) is a sectional view.

FIG. 3 is an explanatory view showing another embodiment of the present invention,
(A) is a left side view and (b) is a sectional view.

FIG. 4 is a cross-sectional view showing a conventional technique.

FIG. 5 is a cross-sectional view showing another conventional technique.

FIG. 6 is an enlarged cross-sectional view showing a state of an insulating adhesive portion.

[Explanation of symbols]

 10 Joint body 10a Hexagonal recessed hole portion of joint body 10b Inner thread 10c Outer thread 10d Connection thread for piping 11 O-ring groove 12 O-ring 20 Cylindrical part 21 Lining layer 30 Bushing 30a Female thread for water supply equipment and screwing 30b Hexagonal convex portion of bush 40 Metal locking member 40a External screw 40b Inner screw 40c Annular protrusion 50 Portion where locking member and bush overlap in the circumferential direction 60 Color

Claims (3)

[Claims] 1. A joint for connecting a pipe and a water supply device, wherein a bush is fixedly coupled to a water supply device connection side of a metal joint body through an electrically insulating member, and the bush is engaged with the joint body. An insulating joint for a water faucet, characterized in that it has an anti-rotation means on the outside and a female screw on the inside for connecting to the water supply device. 2. The insulating joint for water supply equipment according to claim 1, wherein an electrically insulating collar is inserted between the outer peripheral surface of the bush and the inner peripheral surface of the joint body. 3. The inner peripheral surface of the joint body excluding the threaded portion on the pipe side is covered with a synthetic resin lining layer, and extends from this lining layer to the female thread side for connecting with the pipe to cover the inner peripheral surface of the connecting pipe. The insulated joint for water supply equipment according to claim 1 or 2, wherein a tubular portion is provided, and the joint body is shielded from circulating water by the lining layer and the bush.