JPH0882375A - Valve - Google Patents

Abstract

PURPOSE: To prevent the falling off of a joint part and the deformation in a radial direction by a method wherein a thermal fusion joint made of synthetic resin with a built-in heat generating body is integrally fixed to at least one connection port, formed in a valve box, through a locking means to conduct locking both in a connection direction and radial direction. CONSTITUTION: In a ball valve, a ball 13 having a through-hole 12 is rotatably contained in a valve box 10 to which a cap and a body are coupled by means of a screw 11. Ball seats 14 are arranged on both sides of the ball 13 and by rotating a lever handle 15, a flow passage is opened and closed. A thermal fusion joint 18 made of synthetic resin is attached to a connection port 17 formed in the valve box 10 and being an inlet and an outlet. In this case, uneven surface parts 21... and 22 are formed in the outer peripheral surface and the end face in a radial direction of the stepped part 20 of the connection port 17 of a valve body 19. By internally molding the thermal fusion joint 18 made of synthetic resin by utilizing the uneven surface 21 and 22, the connection direction and the radial direction are locked to improve adhesion of the joint.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve such as a ball valve in which a metal valve body and a synthetic resin heat-sealing joint are integrally molded.

[0002]

2. Description of the Related Art Metal pipes are used for water supply, hot water supply, air conditioning, gas pipes, etc., but this metal pipe may cause pollution or water leakage due to rust, corrosion, etc. Recently, there is a tendency that resin pipes are used.

By the way, conventionally, the following means can be mentioned as a method for connecting the resin pipe to the metal valve. First, the method of connecting the resin pipe through the mechanical joint connected to the connection port of the metal valve, and the joint fitting in which the mechanical joint and the heat-sealing joint are integrally joined. A method in which the connection port is connected by screw connection or flange connection, and the resin pipe is fused and attached to the heat fusion joint side, and other fittings consisting of a mechanical joint and a resin pipe are used. There is known a method of connecting a resin pipe with an adhesive agent. In addition, a method has also been proposed in which a resistance heating wire is embedded in a connection port of a synthetic resin valve box and the embedded portion and a resin pipe are fused (see Japanese Utility Model Laid-Open No. 1-131074).

[0004]

However, among the above-mentioned means, the method of connecting through a mechanical joint not only requires a joint component, but also increases the number of working steps and causes rattling during use. If the pipe is pulled out or pulled out, the joint may loosen, which may cause leakage. In addition, a joint tool consisting of a mechanical joint and a heat fusion joint requires a step of connecting the mechanical joint and the valve in addition to the step of fusion with the resin pipe, which leads to an increase in cost due to an increase in the number of parts. Therefore, there has been a strong demand for the development of a connection method that solves this problem.

Further, when the resin heat-sealing joint 2 having the heating element 3 of the fitting 1 shown in FIG. 4 and the metal joint body 4 are joined together, in the case of a joint having a relatively small nominal diameter, they are integrated. Although it is easy to mold, in the case of the fitting 1 having a large nominal diameter, the thickness of the tubular portion of the heat-sealing joint 2 and the joint body 4 becomes thicker, and the resin shrinks after the integral molding. Due to the strain, there is a technical problem such as a decrease in the adhesion performance of the bonded portion as shown in FIG. 4, and therefore there is a problem in bonding the metal body having a large nominal diameter and the resin material.

Since the synthetic resin valve described in Japanese Utility Model Laid-Open No. 1-131074 is a heat fusion type, there is a risk that the seal portion with the valve body provided inside the synthetic resin material is affected by heat. Therefore, parts such as metal packing cases that are not subject to thermal deformation are required, which not only complicates the structure but also increases the cost, which poses a problem in terms of economic value. Had.

The present invention was developed in order to solve the above-mentioned problems that have hitherto existed, and its object is to use a simple means when connecting a resin pipe to a metal valve. An object of the present invention is to provide a valve which has improved adhesion and is excellent in economical efficiency.

[0008]

In order to achieve the above-mentioned object, the present invention provides a metal valve in which a valve body which is opened and closed by turning or raising and lowering a stem is provided inside a metal valve box. , A synthetic resin heat-sealing joint having a built-in heating element is integrally fixed to at least one connection port provided in the valve box via locking means for locking both the connecting direction and the radial direction. It is a valve that constitutes the main body.

This valve is a ball valve, a butterfly valve, a gate valve, a globe valve, a check valve or a plug valve, or other various valves.
Further, the locking means preferably has a structure in which a heat-sealing joint made of synthetic resin is integrally formed with the uneven portion provided on the outer peripheral surface of the step portion of the connection port of the valve body and the uneven portion provided on the end surface in the radial direction. .
The other locking means may have a structure in which the heat-sealing joint is integrally formed with the saw-tooth portion provided on the outer peripheral surface of the step portion of the connection port of the valve body and the uneven portion provided on the radial end surface. Furthermore, the locking means of another example is such that a heat-sealing joint made of synthetic resin is provided on the uneven portion or the sawtooth portion provided on the inner peripheral surface of the step portion of the connection port of the valve body and the uneven portion provided on the end surface in the radial direction. The structure may be integrally formed. In each of the above examples, an adhesive may be applied to the joint surface of the connection port of the valve box in advance.

Further, it is preferable that the joint body of the heat-sealing joint made of synthetic resin is formed in a cylindrical shape from a crosslinkable thermoplastic resin such as crosslinked polyethylene or crosslinked polypropylene.

[0011]

Since the present invention is configured as described above, when a synthetic resin heat-sealing joint is integrally formed with the connection port provided in the valve box, the locking is performed in the connecting direction and the radial direction. Since the means is provided, it is possible to prevent the joining portion from coming off and prevent the distortion in the radial direction, so that it is possible to enhance the adhesiveness of the joining portion.
Since the unevenness is provided on the outer peripheral surface of the step portion of the valve body and the end surface in the radial direction to join the two together, the effect of increasing the adhesiveness of the joint due to heat shrinkage after resin molding .

When a resin pipe is inserted into the joint portion of the valve body and then the heating element is heated, the heating portion provided inside the non-crosslinking thermoplastic resin generates heat and the fusion portion of the heating element The insertion portion of the resin pipe is melted and integrally fused.

[0013]

EXAMPLE An example in which the valve of the present invention is applied to a ball valve will be described in detail below. FIG. 1 is a vertical cross-sectional view of a ball valve, and FIGS. 2 and 3 are partially cut-away cross-sectional views showing another example of the above-mentioned joint portion. In FIG. 1, 1
Reference numeral 0 denotes a metal valve box that is connected by a screw 11 with a cap and a body, and a through hole 1 is provided inside the valve box 10.
A ball 13 having a ball 2 is rotatably provided, and the ball 1
Ball seats 14 are provided on both sides of the lever handle 1
The stem 16 connected to the ball 13 is rotated by rotating the actuator 5 or an actuator (not shown) to rotate the ball by about 90 ° to open and close the flow path. Further, a synthetic resin heat-sealing joint 18 is integrally fixed to one or both of the inlet port and the outlet port 17 provided in the valve box 10 to form the valve body 19.

The engaging means between the connection port 17 and the joint 18 in FIG. 1 is provided with a plurality of uneven portions 21 on the outer peripheral surface of the step portion 20 of the connection port 17 of the valve body 19, and the end surface of the step portion 20 in the radial direction. The heat-sealed joint 18 made of synthetic resin is provided with the uneven portion 22 on the
Are integrally molded and the connection direction and the radial direction are locked to enhance the adhesion of the joint.

FIG. 2 shows another example of the locking means.
FIG. 3 shows an example in which a plurality of sawtooth portions 27 are provided on the outer peripheral surface of the connection opening of the valve body 19, and FIG. 3 shows a locking means of another example. The heat-sealing joint 18 made of synthetic resin is formed on the uneven portion 23 provided on the inner peripheral surface of the step portion 20 of the connection port 17 and the uneven portion 22 provided on the end surface in the radial direction.
Are integrally molded, and the connection direction and the radial direction are locked to enhance the adhesion of the joint.

The joint body 24 of the heat-sealing joint 18 made of synthetic resin is formed in a cylindrical shape from a crosslinkable thermoplastic resin such as crosslinked polyethylene or crosslinked polypropylene. A heating element 25 is provided on the inner peripheral surface of the joint body 24. The heating element 25 is a fusion-bonded portion formed of a non-crosslinking thermoplastic resin such as polyethylene, polypropylene, polybutene, or polyvinyl chloride. It is composed of a heating coil embedded inside the fusion-bonded portion.
This coil is caused to generate heat, and the fusion-bonded portion and the insertion portion of the resin pipe 26 are fused and fused. To heat the coil, the coil is energized to generate heat, or the coil is heated by induction heating that applies a high-frequency magnetic field to the coil from outside the joint body 24.

The above-mentioned example is a ball valve, but it is not limited to this, but it can be applied to a butterfly valve, a gate valve, a globe valve, a check valve, a plug valve or other valves. Of course, it can be applied not only to the two-way valve but also to the three-way valve.

Next, the operation of the above embodiment will be described.
When the synthetic resin heat-sealing joint 18 is formed integrally with the connection port 17 provided in the metal valve box 10, since the uneven portions 22 and 23 and the sawtooth portion 27 are provided in the connection direction and the radial direction, Even if the resin shrinks after the integral molding, the adhesiveness of the joint can be maintained and the sealing performance can be improved.

When the resin pipe 26 is inserted into the joint 18 of the valve body 19 and then the heating element 25 is heated,
The fusion-bonded portion of the heating element 25 and the insertion portion of the resin pipe 26 are melted, and after cooling for a certain period of time, both are integrally molded.

[0020]

As is apparent from the above, according to the present invention, a valve body can be constructed in which a metal valve and a heat-fusion-bonding joint are securely joined in a state in which the adhesion is improved. As described above, the resin pipe can be connected by a simple joining process without requiring an extra mechanical joint, which is not only excellent in economic effect, but also the connecting process can be omitted.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment in which a valve according to the present invention is applied to a ball valve.

FIG. 2 is a partially cutaway cross-sectional view showing another example in which the connection port and the joint portion of the above valve box are joined.

FIG. 3 is a partially cutaway sectional view showing another example of FIG.

FIG. 4 is a partially cutaway cross-sectional view of a heat fusion joint showing a conventional example.

[Explanation of symbols]

 10 Valve Box 13 Ball 17 Connection Port 18 Thermal Fusion Joint 19 Valve Body 20 Step 21 Unevenness 22 Unevenness 23 Unevenness 24 Joint Body 25 Heating Element 26 Resin Pipe 27 Sawtooth Part

Claims (6)

[Claims] 1. A metal valve having a valve body which is opened and closed by turning or raising and lowering a stem inside a metal valve box, wherein at least one connection port provided in the valve box has a connecting direction. A valve body characterized in that a synthetic resin heat fusion joint having a built-in heating element is integrally fixed to the valve body via locking means for locking both in the radial direction. 2. The valve is one of a ball valve, a butterfly valve, a gate valve, a globe valve, a check valve or a plug valve.
The valve described. 3. The locking means is formed by integrally molding a heat-sealing joint made of synthetic resin on the uneven portion provided on the outer peripheral surface of the step portion of the connection port of the valve body and the uneven portion provided on the end surface in the radial direction. The valve according to claim 1 or 2, wherein 4. The heat-sealing joint is integrally formed with the engaging means on the saw-tooth portion provided on the outer peripheral surface of the step portion of the connection port of the valve body and the uneven portion provided on the end surface in the radial direction. Or the valve described in 2. 5. The heat-sealing member made of synthetic resin is attached to the uneven portion or the sawtooth portion provided on the inner peripheral surface of the step portion of the connection port of the valve body and the uneven portion provided on the radial end surface. The valve according to claim 1, wherein the joint is integrally molded. 6. The valve according to claim 1, wherein the joint body of the heat-sealing joint made of synthetic resin is formed in a cylindrical shape from a crosslinkable thermoplastic resin such as crosslinked polyethylene or crosslinked polypropylene.