JPH0942572A - Joint for pipeline - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint for a pipe line, which is free of faults experienced in former joints for a pipeline where a pipe made of synthetic resin is joined with a metallic part in a pipeline system, is excellent in working performance for fusing, and will not transfer any twisting component of winding tendency of a pipe made of synthetic resin to the metallic portion of a pipeline system. SOLUTION: A joint for a pipeline is made up of three components, namely, they are, a metallic sleeve 8, a metallic joint 2 which is rotatably mounted onto one side end part of the metallic sleeve 8, and is provided with a joint end part to be joined with the metallic part of a pipeline system, and an electro fusion joint 1 which is integrally formed at the other end part of the metallic sleeve 8, also allows a pipe made of synthetic resin in a pipeline system to be joined by electro fusion, and is provided with a joint end part where an electric heating wire 3 is buried in a contact surface with a pipe made of synthetic resin, and the electro fusion joint 1 is so constituted in structure that it can be rotated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint for joining a synthetic resin pipe used for pipes for water and sewerage, gas, etc. to a metal portion of the pipe system.

[0002]

2. Description of the Related Art In recent years, pipes made of thermoplastic synthetic resin such as polyethylene having excellent corrosion resistance have come to be used as pipes for water and sewerage and gas. There is a joining method using an electrofusion joint that has been recently developed for joining synthetic resin tubes. This electrofusion joint is one in which a heating wire is embedded in the contact surface with a pipe of a thermoplastic synthetic resin joint, and the synthetic resin on the contact surface is heated and melted by supplying electricity to this heating wire, And the tubes are fused together. In addition, a synthetic resin pipe is joined to the metal part of the piping system (for example, metal connection ports of various machinery and equipment, metal pipes, synthetic resin pipes with metal fittings attached to the joint, etc.) As a joint, one having two parts, an electrofusion joint and a conventionally known metal joint, is known.

[0003]

A conventional joint for joining a synthetic resin pipe to a metal portion of a piping system is such that an electrofusion joint is directly formed at one joint end of the metal joint by an injection molding method. If the metal part of the piping system and the metal joint are joined first, the operator sees the connection terminal to the power supply provided on the outer surface of the electrofusion joint and the confirmation hole for determining the suitability of fusion. May be located behind the electrofusion fitting,
In some cases, the fusion work became difficult to perform. Also, since the synthetic resin tube is wound around the drum etc. in a coil shape,
It has a winding curl, which contains a twisting component in addition to a bending component. Since the conventional joint transmits the twisted component to the metal part of the piping system, for example, the mounting posture of the equipment to be joined to the synthetic resin pipe may change after piping, or the metal joint may be a screw type However, when a screw is formed coaxially with the tube axis made of synthetic resin, this fastening may be loosened.

Therefore, according to the present invention, there is no defect of the conventional pipe joint for joining a synthetic resin pipe and a metal portion of a piping system, the workability of fusion is good, and the winding of the synthetic resin pipe is prevented. It is an object of the present invention to provide a pipe joint that does not transmit a twist component to a metal part of a pipe system.

[0005]

A pipe joint of the present invention for achieving the above object is provided with a metal sleeve, a metal sleeve rotatably attached to one end portion of the metal sleeve, and A metal joint having a joint end portion to be joined to the metal portion, and integrally molded to the other end portion of the metal sleeve,
In addition, a synthetic resin pipe of a piping system is joined by electric fusion, and is composed of three parts of an electrofusion joint having a joint end portion in which a heating wire is embedded in a contact surface with the synthetic resin pipe. is there. This allows the electrofusion joint to rotate with respect to the metal joint, facilitating the fusion work of the synthetic resin tube and the electrofusion joint, and the twisting component of the synthetic resin tube winding It is absorbed and does not reach the metal part of the piping system.

Further, according to the present invention, a retaining member made of a thin metal sleeve is provided on the inner surface of the metal sleeve, and both ends of the retaining member are bent outward to engage with the metal joint side. And a flange portion to be engaged with the end surface of the metal sleeve on the electrofusion joint molding side are formed on the retaining body. This ensures that the electrofusion joint and the metal joint can be securely joined together while allowing the rotation of the electrofusion joint.

Further, according to the present invention, the flange portions at both ends of the retaining member according to claim 2 are provided with an engagement surface on the metal joint side which engages with each flange portion and an end surface on the electrofusion joint molding side of the metal sleeve. A seal member is provided between them. As a result, it is possible to reliably prevent leakage from the joint between the electrofusion joint and the metal joint while allowing the rotation of the electrofusion joint, and at the same time, water enters the joint, that is, the rotating portion, and dead water is generated. Can be prevented.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an overall view of a portion of a socket-type pipe joint that is mainly used for joining a synthetic resin pipe end (not shown) and a metal pipe end (not shown) in a straight line. One of the joint ends is composed of a sleeve-shaped synthetic resin electrofusion joint (hereinafter referred to as an EF joint) for joining the synthetic resin pipe ends by electric fusion, and the other joint end is made of metal. It is composed of a sleeve-shaped screw-in type metal joint (2) for joining the pipe ends made of steel by screwing.

The EF joint (1) has a heating wire (3) embedded in a coil shape on the inner surface which comes into contact with the outer surface of the synthetic resin tube end to be inserted therein, and supplies electricity to the heating wire (3). By doing so, the synthetic resin on the inner surface of the EF joint (1) and the synthetic resin on the outer surface of the pipe end are heated and melted to perform fusion bonding. Therefore, the pipe and the EF joint (1) are made of thermoplastic synthetic resin,
The molding material of the EF joint (1) is the same synthetic resin as the molding material of the pipe. In addition, the heating wire (3) is closely coiled along the cylindrical surface without any gaps and is coiled to retain the shape of a sleeve. Therefore, a coated wire obtained by coating a wire of nickel or nickel alloy with a synthetic resin is used. Short circuit due to mutual contact is prevented. In this case, as the coating resin, the same synthetic resin as the molding material of the EF joint (1) is used. Further, in order to connect to the power supply device at the end surface of the EF joint (1), the heating wire (3) is connected so that both ends of the heating wire (3) to which the power supply connection terminal (4) is attached are drawn from one side. The power supply connection terminals (4) are wound in a coil shape in a folded state and provided in a pair of shaft holes (5) which are close to the end surfaces of the EF joint (1) and open at one end so as to project from the bottom surfaces. . In order to visually check the molten state of the synthetic resin at the time of fusing and to judge whether the electric power supply to the heating wire (3) is continuously interrupted, the inner heating wire (3) is attached to the outer peripheral surface of the EF joint (1). ) Is provided with a small circular confirmation window (6) that allows the molten resin to flow to the outer surface of the EF joint (1) by thermal expansion pressure from the confirmation window (6).

The metal joint (2) has a female taper screw (7) corresponding to a male taper screw cut on the outer surface of the metal pipe end to be joined to the metal joint (2) on the inner surface, and is joined to the metal pipe end. It is done by screwing. As the metal material of the metal joint (2), a commonly used metal material of the joint is selectively used according to the application.

The above EF joint (1) and metal joint (2)
Are connected by a metal sleeve (8) unlike the conventional direct joint type pipe joint. As the material of the sleeve (8), a metal material of a commonly used joint or pipe, like the metal joint (2), is selectively used according to the application. The boss (9) for rotatably fitting one end of the sleeve (8) has a metal joint (2).
Of the boss part (9) provided on the joint side with the EF joint (1) and projecting in a ring shape on the inner surface of the metal joint (2), the inner side of the female taper screw (10) beyond the sleeve insertion hole bottom (10). It is a joint end (11) obtained by cutting 7). At one end of the sleeve (8), the boss (9) of the metal joint (2) is attached.
Is rotatably fitted, and the EF joint (1) is integrally formed with the other end of the sleeve (8) protruding from the boss (9) of the metal joint (2). This gives E
The F joint (1) and the metal joint (2) are rotatably joined to each other.

A retaining member (12) made of a metal sleeve is fitted on the inner surface of the sleeve (8). The outer surface of the retaining body (12) is in close contact with the inner surface of the sleeve (8). Further, one end of the retaining body (12) has a metal joint (2).
Of the sleeve insertion hole bottom (10), and extends back to the inside of the joint end (11) and is folded back inward.
A collar (13) having a heavy structure is formed at one end of the retaining body (12), and the other end of the retaining body (12) extends into the EF joint (1) and serves as a bottom of an insertion hole of the synthetic resin pipe. A double-structured collar (14) is formed on the other end of the retaining body (12) by bending outward and folding back on the outer side of the end face of the sleeve (8) on the side where the EF joint is formed. 12) The collar (13) at one end is the bottom (1) of the sleeve insertion hole of the metal joint (2).
0) and the flange (14) at the other end engages with the end surface of the sleeve (8) on the EF joint forming side in the direction in which the boss (9) of the metal joint (2) comes out from the sleeve (8). , The EF joint (1) and the metal joint (2) are kept in a rotatable joint by the sleeve (8). As the material of the retaining body (12), stainless steel having excellent corrosion resistance is used, and thin sleeves made of stainless steel are used to perform flare processing on both ends.

Between the collar (13) on one side of the retaining body (12) and the rear surface of the sleeve insertion hole bottom (10) of the metal joint (2) engaging with this, and the other side of the retaining body (12). A sealing material is provided between the collar (14) and the end surface of the sleeve (8) that engages with the EF joint molding side, and the O-rings (15) and (16) are used as the sealing material. The one O-ring (15) is pressed against the rear surface side of the sleeve insertion hole bottom (10) of the metal joint (2) by the back surface of the one collar (13) of the retaining body (12), and the two surfaces are opposed to each other. The inner peripheral surface is in close contact with the outer surface of the retaining body (12), and the other O-ring (16) is on the rear surface of the other flange (14) of the retaining body (12) and is on the sleeve (8). The sleeve (8) and the metal joint (2) are joined by being pressed against the end surface of the molding side of the EF joint and closely adhering to the surfaces facing each other and the inner peripheral surface closely adhering to the outer surface of the retaining body (12). Prevents leakage from the surface.

The metal joint (2) is more firmly prevented from coming off from the sleeve (8), and leakage from the joint surface between the sleeve (8) and the metal joint (2) is more reliably prevented. In order to prevent this, two O-rings (17) are provided between the inner surface of the boss (9) and the outer surface of the sleeve (8) of the metal joint (2).
(18) and one metal ring (19), the boss (9) which is fitted to the boss (9) in the sleeve (8).
Ring groove (17a) (18a) (19a) of each ring (17) (18) (19) on the inner surface and ring groove (17b) of each ring (17) (18) (19) on the outer surface of the sleeve (8) ) (17b) (18b).

In order to make the integration of the sleeve (8) and the EF joint (1) stronger, the ring groove (20) is formed on the outer surface of the sleeve (8) covered with the synthetic resin of the EF joint (1).
By providing the EF joint (1), the ring-shaped retaining protrusion (2) that bites into the outer surface of the sleeve (8) is formed on the inner surface of the EF joint (1).
1) forming E, and further covering the outer surface of the sleeve (8) with E
The caulking ring (2) is attached to the small diameter portion on the outer surface of the end of the F joint (1).
2) is provided, and the end portion of the EF joint (1) is caulked and fixed to the sleeve (8) by the caulking ring (22).
It should be noted that the metal surface on the outer surface of the sleeve (8) and the synthetic resin on the inner surface of the EF joint (1) are in close contact with each other and are placed integrally, so that there is no leakage from the joint surface between the EF joint (1) and the sleeve (8).

In the socket type pipe joint constructed as described above, a synthetic resin pipe end is joined to one joint end portion of the joint made of EF joint (1) by electric fusion. Of the metal joint (2), the pipe end made of metal is joined by screwing, and therefore the pipe end made of synthetic resin and the pipe end made of metal are aligned in the joint. To be joined.

When the power supply connection terminal (4) and the confirmation window (6) are located on the opposite side from the operator's side when the EF joint (1) and the synthetic resin pipe are fused together, , The EF joint (1) can be positioned on the operator side by rotating the power supply connection terminal (4) and the confirmation window (6). Since it can be changed, it is excellent in fusion workability. This also applies to the joining of the metallic joint (2) and the metallic pipe.

Further, the twisting component of the winding behavior of the synthetic resin pipe to be joined to the EF joint (1) causes the EF joint (1) to rotate with respect to the metal joint (2), whereby the metal joint (2 ) And the metal pipe to be joined with the metal pipe (2), and the screwing between the metal joint (2) and the metal pipe is not loosened, and instruments are joined to the metal joint (2). When doing so, it is possible to prevent the proper mounting posture of the instrument from being changed.

The socket type pipe joint constructed as described above has ring grooves (17b) (18b) and (19b).
The one side end of the sleeve (8) fitted with the O-rings (17) (18) and the metal ring (19) is press-fitted into the boss (9) of the metal joint (2) for fitting. After that, the O-rings (15) and (16) are attached to both ends of a simple tubular retainer (12) that is press-fitted to the inner surface of the sleeve (8), and flares (13) and (14) are formed by flare processing. To do. This EF joint in the unmolded state and the heating wire (3) which is shaped like a sleeve and has power supply connection terminals (4) at both ends are set in a mold of an injection molding machine, and a sleeve is formed. It can be manufactured by integrally molding the EF joint (1) at one end of (8) and finally caulking and fixing the EF joint (1) to the sleeve (8) with a caulking ring (22).

FIG. 2 is a synthetic resin tube end (not shown).
FIG. 2 is an overall cross-sectional view of a part of another socket-type pipe joint used for joining a metal connection port (not shown) of various machinery and equipment to the pipe joint and the metal joint shown in FIG. 1. Since the other structure is the same except for the shape of the joint end of, the same structure as the pipe joint of FIG. 1 is given the same part number and its description is omitted. The metal joint (2
A) is a union type and has a joint end (11A) made of a cap nut that is slidable in the pipe axis direction, and a parallel screw (not shown) cut on the outer surface of the metal connection port of various machines and instruments. The parallel screw (7a) corresponding to is cut on the inner surface, and is joined to the metal connection port of various machines and appliances by screwing using packing. An edge (9a) for preventing the cap nut (11A) from coming off is provided at the end of the boss (9).

FIG. 3 is also a sectional view of a part of another socket-type pipe joint mainly used for joining a synthetic resin pipe (not shown) and a metal connection port (not shown) of various machines and instruments. FIG. 1 is a general view showing that the pipe joint shown in FIG. 1 is the same as the pipe joint shown in FIG. 1 except for the shape of the joint end, and other structures are the same. And its description is omitted. The metal joint (2
B) has a single-ended nipple-shaped joint end (11B), and a male taper screw (7B) corresponding to a female taper screw (not shown) cut on the inner surface of the metal connection port of various machines and equipment is provided on the outer surface. It has been cut, and various machinery and equipment are joined with metal connection ports by screwing.

In the case of this metal joint (2B), one end of the retaining member (12) extends to the outside of the end face of the joint end (11B), and at this portion, the collar (13) is flared.
Is formed, the collar (13) and the joint end (11
An O-ring (15) is provided between the end face of B).

FIG. 4 shows a flexible pipe (23) in which pipe ends (not shown) made of synthetic resin are joined to both ends by electric fusion.
Is a general view of a section of a portion of the flexible tube (23),
A flexible tube made of stainless steel (hereinafter referred to as "flexible tube") in which the tube walls other than both ends are molded into a sleeve shape.
(24), a braided blade (25) on the outer surface of the flexible tube (24), and a cover rubber (26), and one end (right side of the drawing) of the flexible tube (23) is the EF shown in FIGS. The EF joint (1) is rotatably attached with a pipe joint structure composed of three parts: a joint (1), a metal joint (2), and a metal sleeve (8). That is, at this time, the metal joint (2C) has a sleeve-shaped joint end (7C) having an inner diameter substantially the same as the outer diameter of the straight pipe portion (24a) at the right end of the flexible tube (24). On the outer surface of the straight tube portion (24a) of the flexible tube (24) into which the joint end portion (7C) is inserted,
A metallic caulking ring (7c) fitted to the outside of the joint end (11c) is caulked and fixed to join. As a result, the EF joint (1) is rotatably attached to the end of the flexible pipe (23). On the other hand, the EF joint (1) shown in FIGS. 1 to 3 is fixedly attached to the other end (left side in the drawing) of the flexible pipe (23) by a method of directly joining the sleeve (8). That is, the straight tube portion (24b) at the left end of the flexible tube (24) is inserted into the sleeve (8) with the metal joint removed in the pipe joint structure shown in FIGS. 8) is joined to the outer surface of the straight tube portion (24b) of the flexible tube (24) by caulking and fixing with a metal caulking ring (27) fitted to the outside of the sleeve (8). As a result, the EF joint (1) is fixedly attached to the end of the flexible pipe (23).

As described above, the rotary EF joint (1) is provided at either one end or both ends of the flexible pipe (23).
By mounting the EF joint (1) and the synthetic resin pipe, the fusion workability is improved, and at the same time, the twist from the synthetic resin pipe portion cannot be transmitted to the flexible tube (23). Especially in the case of flexible pipe (23), this pipe (23)
Can be absorbed by the rotation of the EF joint (1) and is not transmitted to the synthetic resin pipe side.

Further, in order to utilize the flexible tube (24) of the flexible tube (23) as a retaining body, the straight tube portions (24a) at both ends of the flexible tube (24).
A collar (28) that extends (24b) through the inside of the left and right sleeves (8) to the inside of the left and right EF joints (1) and engages with the end faces of the left and right sleeves (8) on the EF joint molding side.
1 to 3 are formed on both ends of the flexible tube (24) similarly to the collar (14) shown in FIGS. 1 to 3, and a 0 ring is formed between each collar (28) and the end surface of the sleeve (8) on the EF joint molding side. (2
By providing 9), it is possible to prevent the left and right EF joints (1) from coming off and prevent leakage from the joint portion between these EF joints (1) and the flexible pipe (27).

The metal joint (2) shown in FIGS. 1 to 4.
Instead of the retaining metal ring (19) provided between the boss (9) and the sleeve (8) of (2A) (2B) (2C), the boss (9) as shown in FIG. The ring-shaped projecting portion (30) provided on the inner surface is provided on the outer surface of the sleeve (8) by pressing the boss portion (9) from the outer surface toward the center after fitting the boss portion (9) to the sleeve (8). A caulking type retaining structure that fits in the groove (31) may be used. In this case, the inner diameter of the overhanging portion (30) of the boss portion (9) is substantially the same as or slightly larger than the outer diameter of the sleeve (8). The sleeve (8) and the boss (9) can be easily fitted together.

FIG. 6 shows an EF joint (1) and a metal joint (2).
The structure for sliding not only the rotation but also the tube axis direction of the sleeve (8) is shown, and the ring grooves (17a) (18a) (19a) on the inner surface of the boss (9) of the metal joint (2) are shown.
The width of the ring groove (17b) (1
8b) (19b) width and each ring (17) (18)
By making it wider than the cross-sectional diameter of (19) and wide in one direction, the metal joint (2) can be slid along the outer surface of the sleeve (8) in the pipe axis direction.
Conversely, ring grooves (17b) (18b) on the sleeve (8) side
By widening (19b), it is possible to slide the integrated sleeve (8) and EF joint (1) along the inner surface of the boss (9) of the metal joint (2) in the axial direction of the pipe. . Further, each ring groove (17a) (18a) on both the boss (9) side and the sleeve (8) side of the metal joint (2).
(19a) (17b) (18b) (19b) is made wider than the cross-sectional diameter of each ring (17) (18) (19), so that a metal joint (2) and an integral sleeve are provided as compared with the one side described above. The sliding length of the EF joint (1) is doubled.

The shape of the EF joint (1), the shape of the metal joint, and the shape of the entire pipe joint in the present invention are not limited, and those corresponding to the place of use are given.

[0029]

As is apparent from the above embodiments, the present invention provides a metal sleeve and a joint end rotatably attached to one end of the metal sleeve and joined to a metal portion of a piping system. On a contact surface with a synthetic resin pipe, which is integrally molded with the metal joint having a portion and the other end of the metallic sleeve, and which joins a synthetic resin pipe of a piping system by electric fusion Since the electrofusion joint rotates with respect to the metal joint because it is composed of three parts of the electrofusion joint having the joint end portion in which the heating wire is buried, the electrofusion joint is made of synthetic resin as compared with the conventional pipe joint. The pipe and the EF joint are easily fused together, and the twisting component of the winding of the synthetic resin pipe is absorbed by the joint and is not transmitted to the metal part of the piping system.

Further, according to the present invention, a retaining member made of a thin metal sleeve is provided on the inner surface of the metal sleeve, and both ends of the retaining member are bent outward to engage with the metal joint side. By forming the collar portion that engages with the end surface of the metal sleeve on the electrofusion joint molding side on the retaining body, the EF joint and the metal joint can be joined securely while allowing the rotation of the EF joint. Can be maintained.

Further, according to the present invention, there are provided flange portions at both ends of the retaining member according to claim 2, an engagement surface on a metal joint side which engages with each flange portion, and an end surface on the electrofusion joint molding side of a metal sleeve. By providing a seal member between
While allowing the rotation of the EF joint, it is possible to reliably prevent leakage from the joint between the EF joint and the metal joint, and it is possible to prevent water from entering the joint, that is, the rotating portion, to cause dead water.

[Brief description of drawings]

FIG. 1 is an overall view in which a part of a pipe joint according to the present invention is sectioned.

FIG. 2 is an overall view in which a part of another pipe joint according to the present invention is sectioned.

FIG. 3 is an overall view of a cross section of a part of another pipe joint according to the present invention.

FIG. 4 is an overall cross-sectional view of a part of a flexible pipe having a pipe joint according to the present invention.

FIG. 5 is a partially enlarged cross-sectional view showing a modification of the retaining structure between the sleeve and the metal joint.

FIG. 6 is a partially enlarged cross-sectional view showing a modification of the retaining structure between the sleeve and the metal joint.

[Explanation of symbols]

 (1) Electrofusion joint (2) Metal joint (3) Heating wire (8) Metal sleeve

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Hideaki Baba 312 Ohbo, Mihara-cho, Minamikawachi-gun, Osaka Prefecture

Claims (3)

[Claims] 1. A metal sleeve, a metal joint having a joint end rotatably attached to one end of the metal sleeve and joined to a metal portion of a piping system, and the metal sleeve. Electro having a joint end part integrally molded with the other end part of the piping system, in which a synthetic resin pipe of a piping system is joined by electric fusion bonding, and a heating wire is embedded in a contact surface with the synthetic resin pipe. A piping joint comprising three parts of a fusion joint. 2. A metal sleeve is provided with a retaining member made of a thin metal sleeve on its inner surface, and both ends of the retaining member are bent outward to engage with a metal joint side. The pipe joint according to claim 1, wherein the retaining member is formed with a flange portion that engages with an end surface of the sleeve on the electrofusion joint forming side. 3. Between the flange portions at both ends of the retaining member according to claim 2, the engagement surface on the metal joint side that engages with each flange portion, and the end surface on the electrofusion joint molding side of the metal sleeve. The pipe joint according to claim 1, wherein a seal member is provided.