JP2022128498A - Joint structure having dust-proof cover and valve as well as flexible soft seal gate valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint structure that comprises a resin pipe flexible unit capable of applying flexibility without impairing the advantages of a soft seal gate valve and a joint structure using the resin pipe flexible unit, is excellent in earthquake resistance and workability during plumbing work, and can prevent foreign matter from entering inside even when buried, and a valve as well as a flexible soft seal gate valve .

SOLUTION: A joint structure having a dust-proof cover is provided with: an annular concave-convex part 82 formed by forming a bellows-shaped concave-convex portion with a shallow depth along a centripetal direction from the inside of a bottom part of a cylindrical part 81 of a dust-proof cover 80; an elongated extension cylindrical part 83 in a state of extending in the centripetal direction from the inner peripheral end of the annular concave-convex part, and along an outer end axial direction of a resin pipe part 32, where the extension cylindrical part is brought into contact with the outer peripheral surface of the resin pipe part; and an annular tightening part 84 that is provided on the tip side of the extension cylindrical part, and is fastened to the resin pipe part along the axial direction of the extension cylindrical part in a state of protruding to the outer diameter side of the resin pipe part.

SELECTED DRAWING: Figure 11

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention provides a flexible resin pipe unit that imparts flexibility to a joint portion of a resin pipe, a joint structure and a valve having a dustproof cover using this flexible resin pipe unit, and a flexible type that is flexible by this joint structure. It relates to soft seal sluice valves.

In recent years, resin pipes (for example, polyethylene pipes) have been widely used as water supply pipes. Polyethylene resin is a chemically stable material and is resistant to acids and alkalis, so polyethylene pipes made of polyethylene resin do not corrode and can supply sanitary water for a long period of time.

In addition, compared to vinyl chloride pipes, which are also resin pipes, polyethylene pipes can be bent loosely due to their softness and flexibility. Not only is it possible to reduce the use of bent pipes, material costs and construction work can be reduced, but the monolithic pipes formed by EF (electrofusion) joints are flexible to ground changes caused by earthquakes. It has excellent seismic resistance that follows the displacement.

In recent years, sluice valves installed in water supply pipes have replaced the conventional metal sheet sluice valves with rubber lining on the surface of the valve body and epoxy resin powder coating on the inner and outer surfaces to prevent rust water (red water). ) has come to be used.

Since metal seat gate valves have a wedge effect between the valve body and valve seat, a pocket is provided at the bottom of the valve body and valve seat. In addition to causing pressure loss, foreign matter may accumulate in the pocket. On the other hand, the so-called soft-seal sluice valve stops water by compressing the rubber lining that covers the surface of the valve body. In addition, since foreign matter does not accumulate on the bottom, there is no chance of dust getting caught.

As a method for connecting a soft seal sluice valve having such characteristics and a polyethylene pipe, for example, there is a connection structure using a tightening ring for connecting a valve and a pipe joint disclosed in Patent Document 1. According to this connection structure, the polyethylene pipe can be firmly attached to the soft seal sluice valve without any protrusions disturbing the flow of tap water on the flow path in the soft seal sluice valve or on the inner peripheral surface of the polyethylene pipe. A soft-seal gate valve having polyethylene pipes connected to both sides of the soft-seal gate valve using the connection structure of Patent Document 1 or the like, and having a polyethylene spigot has the advantage that the polyethylene pipe can be directly fused to the spigot by EF welding. Therefore, it is often used for polyethylene pipes in water supply pipes.

By the way, even if polyethylene pipes have excellent seismic resistance that allows them to flexibly follow ground changes caused by earthquakes and are displaced, there is of course a limit to the allowable bending range. A large load is applied to the joint between the valve and the polyethylene pipe, and damage to the joint may occur. Water supply is a very important infrastructure in modern life and is an indispensable lifeline for human life. When a large earthquake occurs, if the joint between the soft seal gate valve and the polyethylene pipe is damaged, it is difficult to partially repair the damaged part on the side of the gate valve. will need to be replaced, and recovery will take time. For this reason, in order to absorb the load on the joint caused by ground fluctuations during an earthquake and prevent damage to the joint between the soft seal gate valve and the polyethylene pipe, the joint between the gate valve and the polyethylene pipe has It is important to provide flexibility and prevent joint failure.

In addition, in water supply work, the connection between the polyethylene insertion port of the soft seal gate valve and the polyethylene pipe is performed on site by EF welding as described above, but in the fusion work of the polyethylene pipes, the axes of both are aligned. If it is done in a state where the axes do not match, or when a displacement load is applied even if the axes are aligned, it will cause a poor installation (poor fusion).

Gate valves are installed in places where it is not possible to secure a large space around structures, bridges, intersections, etc., and in many cases the installation position is fixed. , cannot be moved to a position where joining is easy. In addition, the main body of the gate valve is made of cast iron and is heavy, and does not have the flexibility to be rotated in a direction for easy connection when fusion splicing with a polyethylene pipe. For this reason, when connecting a polyethylene pipe to a polyethylene insertion port of a soft seal gate valve in water supply work, it is provided with an insertion port that can be rotated so that the axis of the polyethylene insertion port and the axis of the polyethylene pipe are aligned, There is a demand for a soft seal gate valve with improved workability.

Patent Literature 2 discloses a flexible ball joint unit that imparts flexibility to a polyethylene pipe and a piping method using the same unit. In this flexible ball joint, an insert portion having a convex spherical outer peripheral surface is fitted into a socket portion having a concave spherical inner peripheral surface, and the insert portion is rotatable with respect to the socket portion. When this unit is connected to the polyethylene spigot of the soft seal sluice valve, the piping near the spigot can be made flexible.

Japanese Patent No. 6033640 Japanese Patent No. 5748632

However, in the flexible ball joint unit of Patent Document 2, the spherical diameters of the concave spherical surface of the receptacle and the convex spherical surface of the receptacle are formed to be larger than the diameters of the pipes connected to the receptacle and the receptacle. By forming the diameter of the through hole provided in the end face of the spigot on the socket part side to be larger than the inner diameter of the pipe to which it is connected, the end face of the spigot on the socket part side can accommodate the inner diameter of the pipe when it is flexible. It is designed so that it does not block. As a result, a part of the inner peripheral surface (concave spherical surface) of the socket is always exposed, creating a recessed stepped portion with respect to the inner peripheral surface of the pipe. Turbulence is generated in the flow, resulting in pressure loss.

In addition, iron rust adheres to the inside of the pipe and valve inside the recessed stepped portion, causing red water. There is also the risk of loss of sexuality.

Therefore, even if the flexible ball joint unit of Patent Document 2 is connected to the polyethylene insertion port of the soft-seal gate valve to provide flexibility, there is a risk that the advantages of current soft-seal gate valves may be lost. , there is a risk that it will not be able to demonstrate its flexibility when an earthquake occurs.

On the other hand, in the above flexible ball joint unit, since the joint portion between the socket and the insertion portion is exposed to the outside, when this unit is buried in the ground, foreign matter such as sand and soil may get into the joint. There is a possibility of getting inside from the part. In this case, foreign matter may be caught between the receptacle portion and the insertion portion, resulting in work failure and inability to flex.

The present invention was developed in order to solve the above problems, and its object is to provide a flexible resin tube unit that can impart flexibility without impairing the advantages of soft seal gate valves. and a joint structure using the resin pipe flexible unit, excellent in earthquake resistance and workability during plumbing work, and a joint structure and valve that can prevent foreign matter from entering the interior even when buried, and a flexible To provide a type soft seal gate valve.

In order to achieve the above object, the invention according to claim 1 provides a flexible joint portion in a state where the joint portion of the joint body is expanded in diameter, and joins a resin pipe portion to the inner peripheral spherical surface portion of this flexible joint portion. A joint structure in which a resin pipe flexible unit is flexibly inserted and a dust cover is attached between the open end of the outer peripheral surface of the flexible joint and the resin pipe, and the bottom of the cylindrical part of the dust cover An annular concave-convex portion is provided along the centripetal direction from the inside, and the depth of the bellows-shaped concave-convex portion is shallow. A long extension cylinder part is provided along the center direction, and this extension cylinder part is brought into contact with the outer peripheral surface of the resin pipe part. The joint structure has a dustproof cover provided with an annular tightening portion that is tightened to the resin pipe portion along the axial direction of the extended tubular portion while protruding radially.

The invention according to claim 2 is a valve in which the joint structure is applied to one end or both ends of the valve body.

The invention according to claim 3 is a flexible soft-seal gate valve in which the valve described above is applied to a soft-seal gate valve.

According to the first aspect of the invention, the dustproof cover can be attached to the opening end of the flexible joint through the cylindrical portion. It deforms so as to follow it, prevents the occurrence of a gap with the resin pipe portion, and reliably prevents the intrusion of foreign matter. In this case, since the extending cylindrical portion is provided from the inner peripheral end of the annular concave-convex portion, and the annular tightening portion for tightening the resin pipe portion is provided at the tip of the extending cylindrical portion, the annular tightening portion and the resin pipe It prevents foreign matter from entering between the part and the part, secures the elasticity of the annular concave and convex part near the inner peripheral end, and maintains the followability to the resin pipe part when the resin pipe is flexible. Even if this is done, the influence of hardened soil and sand on the annular tightening portion can be suppressed, and the tightening force of the annular tightening portion can be reliably maintained to exhibit dust resistance.

According to the inventions of claims 2 and 3, the flexible resin pipe unit is flexibly inserted into and attached to the flexible joint provided at one end or both ends of the main body of the soft seal gate valve. Since a flexible soft-seal gate valve can be configured, even if the polyethylene pipe connected to the soft-seal gate valve is displaced due to changes in the ground when an earthquake occurs, the flexible joint will flex following this displacement. This makes it possible to absorb the impact, prevent damage to the joint between the soft seal gate valve and the polyethylene pipe, and maintain the function of the water supply, which is an important infrastructure.

In addition, since the flexible joint makes the polyethylene insertion port of the soft-seal gate valve flexible, during connection work, there is no gap between the axis of the polyethylene insertion port of the soft-seal gate valve and the shaft center of the polyethylene pipe. If misalignment occurs, the axis of the polyethylene insertion port of the soft-seal gate valve can be aligned with the axis of the polyethylene pipe simply by rotating and flexing the polyethylene port of the soft-seal gate valve. Therefore, it is possible to prevent defective fusion and greatly improve workability.

Furthermore, in the flexible joint where the resin pipe flexible unit is flexibly inserted and attached, the range of the recessed stepped portion (pocket) caused by the exposure of the inner peripheral surface of the enlarged diameter portion is reduced. Occurrence of pressure loss caused by turbulent flow caused by the presence of this recessed stepped portion, generation of red water due to the inflow of iron rust inside the water pipe adhering to the inside of the recessed stepped portion, and foreign matter accumulated inside the recessed stepped portion It is possible to suppress the occurrence of entrapment. For this reason, the soft-seal gate valve is made flexible without impairing the characteristics of the soft-seal gate valve, such as no pressure loss due to the flat straight structure at the bottom of the valve body, and no accumulation of foreign matter on the bottom. can do.

1 is a cross-sectional view showing one embodiment of a flexible soft seal gate valve according to the present invention; FIG. (a) is drawing which shows the left side of the resin pipe flexible unit of this invention, (b) is drawing which shows the front view. It is sectional drawing of FIG.2(b). It is drawing which shows a ring body. It is drawing which shows a press ring. It is drawing which shows a dustproof cover. It is drawing explaining the assembly process of the joint structure of this invention. FIG. 4 is an enlarged view of the flexible portion of the joint structure of the present invention (assembled state); FIG. 4 is an enlarged view of a flexible portion (flexible state) of the joint structure of the present invention; It is drawing which shows the other example of a dustproof cover. 11(a) is an enlarged cross-sectional view of a main part showing the attached state of the dustproof cover of FIG. 10; FIG. (b) is an enlarged cross-sectional view of part A in (a). Fig. 11(a) is an enlarged cross-sectional view of a main part showing a state in which the resin tube flexible unit in Fig. 11(a) is flexible; It is a drawing showing a flexible soft seal gate valve having a joint structure of the present invention on one end side and a flange on the other end side. (a) is a partially cutaway front view showing a state in which a dustproof cover is attached to a joint portion. (b) is an enlarged cross-sectional view of part B of (a). 15(a) is a partially cutaway front view showing an embedded state of the joint portion in FIG. 14. FIG. (b) is a partially cutaway front view showing the flexible state of (a).

The resin pipe flexible unit, joint structure, valve, and flexible soft seal gate valve according to the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of one embodiment of a flexible soft seal gate valve, FIG. 2 is a flexible resin pipe unit, and FIG. 3 is a cross-sectional view of the flexible resin pipe unit.

In FIG. 1, a flexible soft seal gate valve 11 is provided with a connection socket 14 at one end of a valve body 13 of a valve body 12 comprising a soft seal gate valve for water supply, and a flexible joint 15 at the other end. ing. A resin pipe 16 is fitted on the outer peripheral side of the connecting socket 14 , and a cylindrical tightening ring body 17 is fitted on the outer peripheral side of the resin pipe 16 to fix the resin pipe 16 to the connecting socket 14 . In addition, in this figure, the valve body 13a is in a position to open the gate valve.

The flexible joint 15 is formed by enlarging the diameter of the joint 18 of the valve body 13 , and a pressing ring 23 is attached to the open end 19 with the resin tube flexible unit 21 inserted from the open end 19 . is attached, and the resin tube flexible unit 21 is accommodated in a flexible manner.

First, the resin pipe flexible unit 21 will be described. As shown in FIGS. 2 and 3, the resin pipe flexible unit 21 includes a press-fit sleeve 30 having a locking portion 27 on an outer peripheral surface 26 and a collar portion 29 having a rounded surface 28 on the outer end side, A resin tube portion 32 of a predetermined length press-fitted and fixed to the press-fitting sleeve 30, and a ring body 36 having a ball surface 33 connected to the rounded surface 28 and having a retaining portion 35 on an inner peripheral surface 34. It has

As shown in FIG. 3, the press-fit sleeve 30 has a flange 29 on the outer end side of a tubular body having a locking portion 27 protruding from an outer peripheral surface 26. The outer peripheral surface of the flange 29 is rounded. 28, a tapered surface 38 is formed on the inner peripheral surface side. In this embodiment, the press-fit sleeve 30 is made of spheroidal graphite cast iron (FCD450-10), and the entire surface is powder-coated with epoxy resin.

It should be noted that the outer peripheral surface of the collar portion 29 of the press-fitting sleeve 30 is formed into a rounded surface 28 having substantially the same spherical radius as the spherical surface portion 46 formed on the inner peripheral surface of the flexible joint portion 15 for reasons described later. However, if the outer peripheral surface 26 of the flange 29 is formed as an inclined surface corresponding to the tangential angle, or if the flange 29 is formed as a simple flat plate with an appropriate thickness, Even if it does, although it is limited, the effect of the present invention can be obtained.

The press-fitting sleeve 30 has a slightly smaller outer diameter on the side into which the resin pipe portion 32 is press-fitted, and is larger than the inner diameter of the resin pipe portion. It is formed to increase as it approaches the collar portion 29 from the side where the pipe portion 32 is press-fitted. In addition, the inner periphery of the inlet of the resin pipe portion 32 is chamfered to facilitate the work of press-fitting the press-fitting sleeve 30 into the resin pipe portion 32 and to prevent the resin pipe portion 32 from coming out of the press-fitting sleeve 30 after being press-fitted and fixed. exert a different effect.

By forming the tapered surface 38 on the inner peripheral surface side of the collar portion 29 of the press-fit sleeve 30, the body flow path 39 inside the valve body 12 of the valve body 13 and the inner peripheral flow path 40 of the press-fit sleeve 30 are smoothly connected. to suppress the generation of turbulence. In addition, since the diameter of the inner peripheral flow path 40 of the press-fit sleeve 30 is substantially the same as the inner diameter of the connection socket 14 as shown in FIG. Since the channels having substantially the same cross-sectional area are formed smoothly and continuously, the occurrence of pressure loss can be suppressed.

The opening angle of the tapered surface 38 formed on the inner peripheral surface side of the collar portion 29 of the press-fit sleeve 30 affects the securing of the flow passage area and the generation of pressure loss during normal use and flexibility. Although it is necessary to sufficiently trade off the effects on these factors, even when the resin tube flexible unit 21 is flexed, the body flow path 39 inside the valve body 12 and the inner peripheral flow path 40 of the press-fit sleeve 30 are separated as much as possible. The angle slightly larger than the flexible angle .theta. It is preferable to set the angle to 20 degrees or less.

The resin pipe portion 32 is preferably a polyethylene pipe for water distribution, and a polyethylene pipe with a nominal diameter of 50 or 75 can be used. In this embodiment, a case of using a polyethylene pipe with a nominal diameter of 75 is described.

As shown in FIG. 4 , the outer peripheral surface of the ring body 36 is formed on the ball surface 33 , and the inner peripheral surface 34 is provided with the retaining portion 35 and the seal member mounting groove 41 . The retainer portion 35 is provided at a portion closer to the surface of the press-fit sleeve 30 that abuts on the flange portion 29 than the seal member mounting groove 41 , but the retainer portion 35 protrudes from the outer peripheral surface 26 of the press-fit sleeve 30 . Since the resin pipe portion 32 is strongly prevented from slipping off by substantially facing the locking portion 27 that has been bent, the press-fit sleeve 30 is formed to have a sufficiently high locking portion 27 . This is because the retaining portion 35 is provided in the portion corresponding to the neighboring portion.

In addition, the spherical diameter of the ball surface 33 of the ring body 36 is set to be substantially equal to the spherical diameter of the rounded surface 28 formed on the outer peripheral surface side of the flange 29 of the press-fit sleeve 30. When the ring body 36 is brought into contact with the collar portion 29, the ball surface 33 of the ring body 36 and the rounded surface 28 of the press-fit sleeve 30 are connected to form an outer peripheral spherical shape. In this embodiment, the ring body 36 is made of stainless steel (SUS304) and used without coating. The diameter of the inner peripheral surface 34 of the ring body 36 is set to be slightly smaller than the outer diameter of the resin pipe portion 32 into which the press-fit sleeve 30 is inserted. Thereby, the ring body 36 can be press-fitted and fixed to the outer circumference of the resin pipe portion 32 .

After press-fitting the press-fitting sleeve 30 to the inner peripheral side of the resin pipe portion 32, a ring body 36 having a seal member (O-ring made of nitrile rubber) 42 disposed in the seal member mounting groove 41 is attached to the outer peripheral side of the resin pipe portion 32. When press-fitted, as shown in FIG. 3, the engaging portion 27 protruding from the outer peripheral surface 26 of the press-fit sleeve 30 bites into the inner peripheral surface 43 of the resin tube portion 32, and the inner peripheral surface 34 of the ring body 36 is recessed. The resin pipe flexible unit 21 in which the resin pipe portion 32, the press-fit sleeve 30, and the ring body 36 are firmly fixed and integrated is formed by the outer peripheral surface 37 of the resin pipe portion 32 biting into the retaining portion 35 provided. Can be configured.

These press-fitting operations are performed using a press-fitting machine that is used when press-fitting a cylindrical tightening ring body on the outer peripheral side of the resin pipe after press-fitting the resin pipe on the outer peripheral side of the socket for connection of the gate valve. Therefore, it does not become a factor to increase the manufacturing cost. It should be noted that the arrangement of the retaining portion 35 and the sealing member is arbitrary.

The resin pipe flexible unit is not limited to the above structure as long as the resin pipe portion 32 can be flexibly inserted into the spherical portion 46 of the inner peripheral surface of the flexible joint portion 15 of the joint portion 18. It can be provided in various internal structures. Furthermore, although the valve body 12 to which this resin pipe flexible unit is joined is applied to the soft seal gate valve 11, it may be applied to valves other than the soft seal gate valve.

Next, the flexible joint 15 provided on the other end side of the valve body 13 of the valve body 12 will be described.
As described above, the flexible joint 15 is provided in a state in which the diameter of the joint 18 of the valve body 13 is expanded, has an open end 19, and has a concave spherical surface 46 on the inner peripheral surface. there is The spherical surface diameter of the spherical surface portion 46 is formed substantially equal to the spherical surface spherical diameter of the rounded surface 28 of the collar portion 29 of the press-fit sleeve 30 and the spherical surface spherical diameter of the ball surface 33 of the ring body 36 .

A stepped portion 48 for mounting a seal member 47 following the spherical portion 46 is provided on the inner peripheral surface of the flexible joint portion 15 . A bolt hole 52 for attaching the pressing ring 23 is provided in a circumferential shape at the open end 19 of the flexible joint 15, and a dustproof cover 61, which will be described later, is engaged with the outer periphery of the open end 19. A protrusion 53 for attachment is protruded in an annular shape.

As shown in FIG. 5(b), the pressing ring 23 is formed in a substantially donut shape with an insertion hole 55 for inserting the resin pipe portion 32 of the resin pipe flexible unit 21 in the center. is provided with a bolt hole 56 in a circumferential shape. Further, as shown in FIG. 5(a), a stepped portion 57 is formed in the thickness direction of the push ring 23, and this stepped portion 57 is inserted into the open end portion 19 of the flexible joint portion 15, and the flexible joint portion 15 is The pressing ring 23 is attached to the open end portion 19 of the flexible joint portion 15 with the axial center of the pressing ring 23 aligned with the axial center of the pressing ring 23 .

Further, the inner peripheral side of the insertion hole 55 on the side of the stepped portion 57 is formed as a contact rounded surface 58, and the spherical surface portion 46 of which the spherical diameter of the contact rounded surface 58 is provided on the inner peripheral surface of the flexible joint portion 15. , so that when the press ring 23 is attached to the open end 19 of the flexible joint 15, the contact radius surface 58 of the press ring 23 and the spherical surface 46 of the flexible joint 15 are aligned with the center. A spherical surface with the same spherical diameter is constructed. As described above, the presence of the stepped portion 57 ensures that the axial center of the flexible joint 15 and the axial center of the push ring 23 are aligned. Such an effect can be obtained just by installing it. Furthermore, when the press ring 23 is attached to the open end 19 of the flexible joint 15, the space surrounded by the tip surface of the press ring 23, the inner peripheral surface of the flexible joint 15, and the ball surface 33 of the ring body 36 is An accommodating portion for mounting the seal member 47 is formed.

The side opposite to the stepped portion 57 of the insertion hole 55 is formed as an enlarged diameter hole 60 whose diameter is enlarged toward the end face 59, so that the flexible region of the resin pipe portion 32 of the resin pipe flexible unit 21 when flexible is increased. In addition, when the resin pipe portion 32 of the resin pipe flexible unit 21 comes into contact with the inner peripheral surface of the enlarged diameter hole 60, the flexible range of the resin pipe flexible unit 21 can be restricted.

In this embodiment, the press ring 23 is made of spheroidal graphite cast iron (FCD450-10) like the press-fitted sleeve 30, and the entire surface is powder-coated with epoxy resin.

In this embodiment, the flexible joint is provided at one end of the valve body 12, but may be provided at one or both ends of the valve body or a joint body (not shown).

The dustproof cover 61 is attached between the open end 19 of the flexible joint 15 and the resin tube portion 32 . The dustproof cover 61 is made of a flexible material such as rubber, and as shown in FIG. It is formed by continuously increasing toward. A groove portion 65 is provided on the inner peripheral side of the open end 62 for inserting the protrusion 53 projecting annularly from the outer periphery of the open end portion 19 of the flexible joint portion 15 .

An insertion hole 66 having a smaller diameter than the outer diameter of the resin pipe portion 32 of the flexible resin pipe unit 21 is formed in the center of the bottom portion 63 of the dustproof cover 61, and a projection having a sharp tip is formed on the inner periphery of the insertion hole 66. Along with providing a portion 67, as shown in FIG. 6, a bellows portion 68 is provided around the insertion hole 66 so that the depth width is changed concentrically and folds are formed.

By forming the bellows portion 68 with a different depth width concentrically with the insertion hole 66 in the bottom portion 63 of the dustproof cover 61, the dustproof cover 61 can be given sufficient stretchability, and the resin when flexible. The dustproof cover 61 is flexibly deformed following the movement of the tube flexible unit 21, and the cover state can be maintained. By increasing the depth of the uneven portion of the bellows portion 68, the flexibility is improved and the movement of the flexible resin pipe unit 21 can be easily followed.

In addition, since the side surface 64 of the dustproof cover 61 is formed by increasing the thickness continuously from the bottom portion 63 toward the opening end 62, and the groove portion 65 is provided on the inner peripheral side of the opening end 62 where the thickness is increased most, this The groove portion 65 is hard to deform and has a sufficient holding force. Even if the dustproof cover 61 is deformed when the flexible resin tube unit 21 is flexed, the projection portion 53 is continuously held in the groove portion 65 and the dustproof cover is held. 61 can be prevented from coming off the flexible joint 15 .

On the insertion hole 66 side of the dustproof cover 61, a thick annular tightening portion 69 is provided so as to protrude in the inner peripheral direction. The tightening portion 69 is formed with an appropriate thickness and length so as to be in contact with the outer periphery of the resin pipe portion 32 at a position where it does not protrude outward from the bellows portion 68 on the connection port side of the resin pipe portion 32 . By providing the tightening portion 69 , the diameter of the insertion hole 66 is made smaller than the outer diameter of the resin pipe portion 32 . Therefore, the dustproof cover 61 is attached to the resin tube portion 32 by enlarging the diameter of the insertion hole 66 .

Further, the dust-proof cover 61 has a protrusion (lip) 67 with a sharp tip on the inner peripheral side of the insertion hole 66 formed to have a smaller diameter than the outer diameter of the resin pipe portion 32 of the flexible resin pipe unit 21 . are provided. The protrusion 67 not only facilitates the insertion of the resin tube portion 32 of the flexible resin tube unit 21 into the dustproof cover 61, but also provides a restoring force generated by the expansion of the diameter of the protrusion 67 due to the insertion of the resin tube portion 32. , the outer peripheral surface 37 of the resin pipe portion 32 is strongly gripped to exert a dust sealing effect and a braking function. The cover state can be maintained without moving and without impairing the dust sealing function.

In this embodiment, the dustproof cover 61 is made of ethylene propylene rubber (EPDM), which is excellent in water resistance, weather resistance, cold resistance, and ozone resistance.

Next, referring to FIG. 7, the process of assembling the resin pipe flexible unit and joint structure of the present invention will be described. The first step is the assembly step of the resin tube flexible unit. In this step, as shown in FIG. 7(a), the collar portion 29 of the press-fitting sleeve 30 is supported by a jig (not shown), and the resin pipe portion 32 is pressed to move the press-fitting sleeve 30 toward the inner peripheral side of the resin pipe portion 32. As shown in FIG. press into. At this time, the press-fitting sleeve 30 is press-fitted while expanding the diameter of the resin pipe portion 32 , so that the locking portion 27 projecting from the outer peripheral surface 26 of the press-fitting sleeve 30 bites into the inner peripheral surface 43 of the resin pipe portion 32 . It is press-fitted and fixed.

In the next step, as shown in FIG. 7(b), the collar portion 29 of the press-fitted sleeve 30 press-fitted and fixed to the inner peripheral side of the resin pipe portion 32 is supported by a jig (not shown), and the seal member mounting groove 41 is sealed. The ring body 36 with the member 42 arranged thereon is press-fitted to the outer peripheral side of the resin pipe portion 32 . At this time, the inner peripheral surface 34 of the ring body 36 is press-fitted while strongly pressing the outer surface of the resin pipe portion 32 whose diameter is expanded by press-fitting the press-fitting sleeve 30 . The ring body 36 and the resin pipe portion 32 to which the press-fit sleeve 30 is press-fitted are press-fitted and fixed in a state in which the outer peripheral surface 37 of the resin pipe portion 32 bites into the retainer portion 35 recessed in the outer circumference. At this time, the locking portion 27 of the press-fitting sleeve 30 and the retainer portion 35 of the ring body 36 are disposed substantially opposite to each other, thereby forming the resin tube flexible unit 21 that is firmly fixed and integrated.

Next, the process moves to the assembly process of the joint structure. In this step, as shown in FIG. 7(c), a sealing member 47 is attached to the stepped portion 48 of the flexible joint 15, and the resin tube flexible unit 21 completed in the previous step can be moved from the open end portion 19. Insert into flex joint 15 . After that, the stepped portion 57 of the push ring 23 is inserted into the open end portion 19 of the flexible joint portion 15 while inserting the resin pipe portion 32 of the flexible resin pipe unit 21 into the insertion hole 55, and the flexible joint portion 15 is opened. attached to the open end 19 of the .

Next, as shown in FIG. 7(d), a bolt 70 is passed through the bolt hole 56 of the press ring 23 and screwed into the bolt hole 52 provided circumferentially in the open end 19 of the flexible joint 15. The joint structure is then completed. At this time, since the stepped portion 57 of the pressing ring 23 is inserted into the open end portion 19 of the flexible joint portion 15, the axial center of the flexible joint portion 15 and the axial center of the pressing ring 23 are reliably aligned. In addition, since the press ring 23 is firmly bolted to the open end 19 of the flexible joint 15, the spherical surface portion 46 of the flexible joint 15 and the contact radius surface 58 of the press ring 23 are spherical. Concave inner peripheral spherical surfaces having the same spherical diameter are continuously provided.

As described above, the rounded surface 28 of the flange 29 of the press-fitting sleeve 30 of the flexible resin pipe unit 21 and the ball surface 33 of the ring body 36 are connected to form an outer peripheral spherical shape. , the contact radius surface 58 of the press ring 23, the radius surface 28 of the press-fit sleeve 30, and the ball surface 33 of the ring body 36 are formed to have the same spherical diameter. The inner peripheral spherical surface formed by the abutting rounded surface 58 of the pressing ring 23 is rotated and flexible with the outer peripheral spherical surface formed by the rounded surface 28 of the resin tube flexible unit 21 and the ball surface 33 of the ring body 36. can support. If the push ring 23 is attached to the open end 19 of the flexible joint 15 by a bayonet method, the push ring 23 cannot be securely attached to the open end 19 and looseness will occur. Since the surface where the spherical surface of the flexible joint and the contact radius surface of the press ring are connected cannot form a correct inner peripheral spherical surface, the rotation and flexibility of the resin pipe flexible unit may be affected, or the resin pipe may be damaged. When the flexible unit rotates and bends, it may come off the rotation track and the spherical surface of the flexible joint may be damaged by the end face of the ring body.

The method of joining the press ring 23 to the open end 19 of the flexible joint 15 is not limited to the above-described bolting. 58 are continuously arranged to form a correct inner peripheral spherical surface. , and the push ring 23 may be screwed onto the flexible joint 15 .

Finally, by attaching the dustproof cover 61, the resin pipe flexible unit 21 is dustproof without affecting its rotation and flexibility, and foreign matter is prevented from being caught between the pressing ring 23 and the ring body 36. be able to.

The details and operation of the joint structure of the present invention are described below. FIG. 8 is an enlarged view of the flexible portion of the joint structure of the present invention, showing the completed assembly. Normally, the joint structure 72 is used with the axial center 73 of the flexible joint 15 and the axial center 74 of the resin pipe flexible unit 21 aligned, as shown in this figure.

As shown in FIG. 8, the collar portion 29 of the press-fit sleeve 30 of the resin tube flexible unit 21 is positioned within the inner peripheral spherical surface formed by the spherical surface portion 46 of the flexible joint portion 15 and the contact rounded surface 58 of the pressing ring 23. The rounded surface 28 and the ball surface 33 of the ring body 36 enclose an outer peripheral spherical surface. The spherical diameter of the inner peripheral spherical surface formed by connecting the spherical surface portion 46 of the flexible joint 15 and the contact rounded surface 58 of the press ring 23, and the rounded surface 28 of the collar portion 29 of the press-fit sleeve 30 of the resin tube flexible unit 21 and the ring. Since the spherical diameters of the outer peripheral spherical surfaces connected to the ball surfaces 33 of the body 36 are substantially equal and share the center 75, the resin tube flexible unit 21 is formed by the spherical surface portion 46 of the flexible joint 15 and the pressing ring 23. It is rotatably and flexibly supported within the inner peripheral spherical surface where the contact rounded surface 58 is continuously provided.

As a result, the flexible resin pipe unit 21 is rotatably and flexibly connected to the flexible joint 15, so that when an earthquake occurs, the water pipe connected to the resin pipe portion 32 of the flexible resin pipe unit 21 may be broken into the ground. When it is displaced due to fluctuation, it can be rotated and flexed accordingly. In this embodiment, the flexible region of the resin tube flexible unit 21 is set to about 15 degrees, and the diameter expansion angle of the diameter expansion hole 60 of the pressing ring 23 is set accordingly.

If the axis of the resin pipe portion 32 does not coincide with the axis of the water pipe (polyethylene pipe) connected thereto during the connection work, the resin pipe flexible unit 21 is made flexible. By aligning the axial center of the pipe portion 32 with the axial center of the water pipe, it is possible to prevent installation defects (fusion defects).

The press-fit sleeve 30 has a collar portion 29 and a rounded surface 28 is formed on the outer peripheral surface side of the collar portion 29 , so that the rounded surface 28 of the collar portion 29 conforms to the spherical surface portion 46 of the flexible joint 15 . The range of the recessed stepped portion (pocket) 78 caused by the contact and the exposure of the spherical portion 46 of the flexible joint 15 is greatly reduced.

As a result, pressure loss caused by turbulent flow caused by the recessed stepped portion 78 occurs, red water occurs due to the inflow of iron rust inside the water pipe adhering to the inside of the recessed stepped portion 78, and foreign matter accumulates inside the recessed stepped portion 78. It is possible to suppress the occurrence of jamming caused by.

When fluid pressure is applied, the resin tube flexible unit 21 is pushed toward the press ring 23, and the contact radius surface 58 of the press ring 23 supports the ball surface 33 of the ring body 36 in a flexible state.

Further, the application of the fluid pressure also moves the seal member 47 disposed at the stepped portion 48 of the flexible joint 15 toward the push ring 23 , so that the open end 19 of the flexible joint 15 is closed while being in close contact with the push ring 23 . and the ring body 36 in a flexible state.

Next, referring to FIG. 9, the flexible state of the resin tube flexible unit 21 will be described. FIG. 9 shows a state in which the resin pipe flexible unit 21 is maximally flexible with respect to the flexible joint 15 . At this time, the angle θ between the axis 73 of the flexible joint 15 and the axis 74 of the flexible resin pipe unit 21 is 15 degrees, and the outer peripheral surface of the resin pipe portion 32 of the flexible resin pipe unit 21 is the press ring. 23 is in contact with the inner peripheral surface of the enlarged diameter hole 60, and further flexibility is restricted.

At this time, the range where the inner peripheral surface of the enlarged diameter hole 60 of the press ring 23 and the outer peripheral surface of the resin pipe portion 32 contact is the outer peripheral surface 26 of the press-fitted sleeve 30 press-fitted and fixed to the inner peripheral side of the resin pipe portion 32. , the force received by the resin pipe portion 32 from the inner peripheral surface of the enlarged diameter hole 60 of the press ring 23 due to the flexibility of the resin pipe flexible unit 21 is supported by the press-fit sleeve 30, and the resin pipe portion 32 is deformed. can be prevented.

Further, since the tapered surface 38 is formed on the inner peripheral surface side of the collar portion 29 of the press-fitting sleeve 30, the flow path of the joint portion 18 with respect to the body flow path 39 is sharp when the resin pipe flexible unit 21 is in a flexible state. It is possible to prevent a change in area, suppress pressure loss during bending, and secure a flow path.

The influence of the flexible resin tube unit 21 also affects the dustproof cover 61, but as described above, the bottom 63 of the dustproof cover 61 is formed with the bellows portion 68 by changing the width of the depth. Since the dustproof cover 61 is provided with sufficient stretchability, the dustproof cover 61 can be flexibly deformed following the movement of the resin tube flexible unit 21 when it is flexible.

When the dust-proof cover 61 is attached to the flexible joint 15, the groove 65 of the dust-proof cover 61 into which the projection 53 of the flexible joint 15 is inserted is provided at the portion where the thickness of the side surface 64 increases the most. It is difficult to deform and has a sufficient holding force, so that even if the dustproof cover 61 is deformed, the protrusion 53 can be kept in the groove 65 without being affected by the deformation.

In addition to this, the dustproof cover 61 has a protrusion (lip portion) with a sharp tip on the inner peripheral side of an insertion hole 66 formed to have a smaller diameter than the outer diameter of the resin pipe portion 32 of the flexible resin pipe unit 21 . 67 is provided. The protrusion 67 not only facilitates the insertion of the resin tube portion 32 of the flexible resin tube unit 21 into the dustproof cover 61, but also provides a restoring force generated by the expansion of the diameter of the protrusion 67 due to the insertion of the resin tube portion 32. , the outer peripheral surface 37 of the resin pipe portion 32 is strongly gripped to exert a dust sealing effect and a braking function. The cover state can be maintained without moving and without impairing the dust sealing function.

Next, another example of the dustproof cover described above will be described. 10 shows another example of the dustproof cover, and FIGS. 11A and 12 show the attached state of the dustproof cover of FIG. In addition, hereinafter, the same parts as those described before are indicated by the same reference numerals, and the description thereof is omitted.

The dust-proof cover 80 of FIG. 10 includes a cylindrical portion 81, an annular uneven portion 82, an extended tubular portion 83, and an annular tightening portion 84. As with the dust-proof cover 61, the flexible joint portion 15 and the open end portion 19 are provided. mounted between.
The cylindrical portion 81 is formed in a substantially cylindrical shape with a diameter that can be attached to the open end portion 19 , and an annular concave-convex portion 82 is provided at the tip of the cylindrical portion 81 .

The annular concave-convex portion 82 is provided inside the bottom portion 63 along the centripetal direction from the cylindrical portion 81 in a bellows shape with a width W that is uniform in the depth direction. Thus, each concave-convex portion of the annular concave-convex portion 82 is formed shallow.

The extension tube portion 83 is formed to extend from the inner peripheral end 82 a of the annular concave-convex portion 82 in the direction of the axis 74 of the resin pipe portion 32 by a length L. As shown in FIG. The inner peripheral end 82a is located on the side of the bottom 63 of the annular concave-convex portion 82, and the extended tubular portion 83 is provided from the inner peripheral end 82a, so that the extended tubular portion 83 contacts the outer periphery of the resin pipe portion 32. becomes longer and the contact area with the resin pipe portion 32 becomes larger.

In FIG. 11(b), the annular tightening portion 84 is provided on the distal end side of the extended tubular portion 83, and extends through the extended tubular portion 83 from the bent portion with the resin pipe portion 32 composed of the annular concave-convex portion 82. spaced apart. The annular tightening portion 84 protrudes toward the outer circumference (outer diameter) of the extended cylindrical portion 83 and has a thickness T that is approximately half the length of the extended cylindrical portion 83 in the axial center 74 direction. formed by The thickness T and length of the annular tightening portion 84 can be set appropriately.
With the above configuration, the dustproof cover 80 is provided in a shorter shape than the dustproof cover 61 described above in the insertion port (axis 74) direction.

Here, when installing a dustproof cover with such a structure, when the joint portion and the valve are buried in the ground, sand and dirt may be trapped in the concave portion on the outside of the annular uneven portion (the side in contact with sand and soil). The soil is pushed in and can become tamped and fixed in this state. In this case, the expansion and contraction flexibility of the bellows of the annular concave-convex portion is extremely lost, and when the resin pipe portion is bent by an external force or the like in this state, the following of the dust-proof cover is hindered, and the resin pipe portion of the dust-proof cover is bent. A gap is generated on the contact side, and there is a risk that sand and soil will enter one after another from this gap. As a result, sand and soil also enter the joint portion, reducing the flexibility of the resin pipe flexible unit and also causing a problem that it is difficult to restore the pipe to its original state. As a result, the functionality is significantly lost and the commercial value is also lowered.

On the other hand, in the dustproof cover 80 of the present embodiment, in FIGS. 11A and 11B, the extended tubular portion 83 extends from the inner peripheral end 82a of the annular uneven portion 82 on the bottom portion 63 side to the resin pipe. Extending along the axial direction of the portion 32 , an annular tightening portion 84 is provided at the distal end portion of the extended tubular portion 32 . Therefore, for example, when the resin pipe portion 32 is bent in the X direction due to an external force or the like, it is less likely to be affected by the annular concave-convex portion 82 formed by compaction of sand or soil, and an annular The tightening portion 84 tightens the resin pipe portion 32, and the annular concave-convex portion 82 near the inner peripheral end 82a and the extended cylindrical portion 83 extend and bend so as to follow the flexibility of the resin pipe portion 32, whereby the annular tightening is achieved. It is possible to reliably prevent the occurrence of a gap between the attached portion 84 and the resin pipe portion 32 . As a result, even when the resin pipe flexible unit 21 is in the flexible state shown in FIG. 12, sand and soil are prevented from entering. The dustproofness of the contact portion between the resin pipe portion 32 and the dustproof cover 80, which requires particularly high conformability, can be ensured without being affected by the dust.

Moreover, by reducing the width W of the annular concave-convex portion 82 and providing a shallow depth of the concave-convex portion, the amount of sand or soil pushed into the concave portion is reduced, and the bendability of the annular concave-convex portion 82 is reduced. is suppressed.
The extension cylinder portion 83 is formed in a long shape with a length L, and the contact area between the extension cylinder portion 83 and the resin pipe portion 32 is increased. It becomes possible to enhance the retention (integrity). By providing the annular tightening portion 84 with approximately half the length of the extended tubular portion 83 in the axial center 74 direction, the tightening force of the annular tightening portion 84 is increased, while the length of the other portions The degree of freedom of the extension cylindrical portion 83 as a whole is increased to improve followability.

In this example, since the dust-proof cover 80 is provided in a short shape, the installation length of the dust-proof cover 80 in the axial center 74 direction of the resin tube portion 32 can be shortened. As a result, for example, when the resin pipe portion 32 is joined to an external resin joint (not shown) by EF joining or the like, the dustproof cover 80 does not interfere with the work, thereby improving workability.

As described above, the joint structure using the resin pipe flexible unit of the present invention reduces the range of the recessed stepped portion caused by the exposure of the inner peripheral surface of the expanded diameter portion that accommodates the resin pipe flexible unit. , a substantially straight flow path can be obtained in the joint structure. For this reason, the soft-seal gate valve is made flexible without impairing the features of the soft-seal gate valve, such as no pressure loss due to the flat straight structure at the bottom of the valve body, and foreign matter not accumulating at the bottom. It is the optimal joint structure for

In addition, the above description is based on the premise that the soft seal gate valve having a polyethylene insertion port with polyethylene pipes connected to both side connection portions is made flexible, but the present invention is not limited to this. , as shown in FIG. 13, can also be used to provide flexibility to one side of a sluice valve with a flanged construction on one side, and to provide flexibility to ordinary joints in addition to sluice valves. Of course, it can also be used for

Next, as an example of the joint structure described above, an experimental example in which the joint portion to which the dustproof cover is attached is buried will be described. FIG. 14 shows a state in which the dustproof cover 80 is attached to the joint portion described above, and FIG. 15 shows a state in which the joint portion in FIG. 14 is embedded.

The resin pipe portion 32 to be connected in this embodiment is made of a polyethylene pipe with a diameter of 50 mm.
Before burying the joint portion, a marking line 85 was drawn with a pen on the outer circumference of the resin pipe portion 32 at the end surface position of the annular tightening portion 84 as a reference line.

In the state before embedding in FIG. 14(a), the inner peripheral end 82a is located on the bottom portion 63 side in the direction of the axis 74, and the total length S1 of the dustproof cover 80 at this time is 80 mm. From this state, even if the joint portion (and valve) is buried and sand or soil is tamped down, and the vicinity of the extended tubular portion 83 is displaced in the direction of the valve (joint portion 18), in FIG. 14(b), The annular space G provided between the ring body 36, the pressing ring 23, and the resin pipe portion 32 is free from the risk of the extended cylindrical portion 83 and the annular tightening portion 84 entering. As a result, the space G for flexing the dustproof cover 80 as a whole is secured even after the burying, and the predetermined flexing angle θ of the resin tube flexible unit 21 can be secured.

Subsequently, mountain sand Sa was laid in the box and tamped down to bury the joint portion. FIG. 15(a) shows a state in which the joint portion to which the dustproof cover of FIG. 14(a) is attached is embedded and tamped down.
In this state, part of the mountain sand Sa on the outer peripheral side of the joint portion was excavated and the total length of the dustproof cover 80 was measured, and the total length S2 was 70 mm. At this time, it was confirmed from the position of the marking line 85 that the annular tightening portion 84 side was displaced from the initial position indicated by the two-dot chain line toward the valve side (arrow side) by a distance ΔS=10 mm. From these facts, it was confirmed that the dustproof cover 80 was tamped down with mountain sand Sa at the time of burying, and that the opening portion was pushed into the valve side by about 10 mm.

Next, after the excavated portion was buried and tamped down, and the flexible resin tube unit 21 was made flexible at a flexible angle θ of 15 degrees, a part of it was dug up again and the state of the dustproof cover 80 was checked.
In this case, as shown in FIG. 15(b), although a space R is formed in the original position of the resin tube portion 32 due to the flexibility, the annular concave-convex portion 82 acts as a bellows due to the impact of tamping into the concave portion. Impairment of function and difficulty in movement. However, the annular tightening portion 84 was not substantially displaced from the tightening position immediately after the embedding, and no deformation in the radially expanding direction was confirmed.

15(a), the vicinity of the inner peripheral end 82a, the annular concave-convex portion 82, and the extended tubular portion 83 are arranged to follow the flexibility of the resin pipe portion 32 and extend. On the other hand, on the lower side of the shaft center 74, the extended tubular portion 83 is deformed so as to be bent, so that it is less likely to be affected by the tamping of the annular concave-convex portion 82. Due to the functionality of this dustproof cover 80, even if the resin pipe flexible unit 21 is flexed due to an earthquake or the like, it is possible to suppress the occurrence of gaps with the resin pipe portion 32 and reliably prevent sand and soil from entering. becomes.

REFERENCE SIGNS LIST 11 flexible soft seal gate valve 12 valve main body 13 valve body 15 flexible joint 18 joint 19 opening end 21 resin pipe flexible unit 23 press ring 27 locking portion 28 rounded surface 29 flange 30 press-fit sleeve 32 resin pipe Part 33 Ball surface 35 Retaining part 36 Ring body 42 Sealing member 46 Spherical surface part 58 Abutting R surface 61, 80 Dustproof cover 74 Axial center 81 Cylindrical part 82 Annular uneven part 82a Inner peripheral end 83 Extended cylindrical part 84 Annular tightening Department

Claims (3)

A flexible joint is provided in a state in which the diameter of the joint of the joint body is expanded, and a flexible resin pipe unit having a resin pipe joined to the inner peripheral spherical surface of the flexible joint is flexibly inserted into the flexible joint. A joint structure in which a dustproof cover is attached between the open end of the outer peripheral surface of the flexible joint and the resin pipe portion, and a bellows-shaped uneven portion extending from the inside of the bottom of the cylindrical portion of the dustproof cover in the centripetal direction. is formed with a shallow depth, extends in the centripetal direction from the inner peripheral end of the annular uneven portion, and extends along the outer end axial direction of the resin pipe portion. An extended tubular portion is provided, and this extended tubular portion is brought into contact with the outer peripheral surface of the resin pipe portion. A joint structure having a dustproof cover, characterized in that an annular tightening portion is provided which is tightened to the resin pipe portion along the axial direction of the extended tubular portion. A valve, wherein the joint structure according to claim 1 is applied to one end or both ends of a valve body. A flexible soft-seal gate valve, wherein the valve according to claim 2 is applied to a soft-seal gate valve.

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