JP7350943B2 - Joint structure and valve with dustproof cover and flexible soft seal gate valve - Google Patents

Description

The present invention relates to a resin pipe flexible unit that provides flexibility to the joint of a resin pipe, a joint structure and a valve that have a dustproof cover using this resin pipe flexible unit, and a flexible type that is flexible using this joint structure. Regarding soft seal gate valves.

In recent years, resin pipes (for example, polyethylene pipes) have come to be frequently used as water distribution 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 so-called due to the flexibility of the pipe itself, so gentle bends can be made by bending the pipes. Not only can this reduce the use of curved pipes, reducing material costs and construction labor, but the monolithic pipe formed by EF (electrofusion) joints is more flexible to ground movements caused by earthquakes. It has excellent earthquake resistance that allows it to move according to the earthquake.

In addition, in recent years, gate valves installed in water pipes have been replaced with conventional metal sheet gate valves by coating the surface of the valve body with a rubber lining and applying epoxy resin powder coating to the inside and outside surfaces. ) soft-seal gate valves that prevent the occurrence of

Metal seat gate valves have a pocket at the bottom of the valve body valve seat to create a wedge effect between the valve body valve seat and the valve body valve seat.This pocket causes turbulence in the flow inside the valve. Not only will this cause pressure loss, but there is also the risk of foreign matter accumulating in the pockets. On the other hand, so-called soft-seal gate valves compress the rubber lining on the surface of the valve body to shut off water, so they have a straight structure with a flat bottom of the valve body, and the flow inside the valve is not disturbed, resulting in pressure loss. Also, since foreign matter does not accumulate on the bottom, there is no chance of dirt getting caught.

As a method for connecting a soft seal gate valve having such characteristics and a polyethylene pipe, there is, for example, a connection structure using a tightening ring for connecting a valve/pipe joint as disclosed in Patent Document 1. According to this connection structure, the polyethylene pipe can be firmly attached to the soft seal gate valve without creating protrusions that disturb the flow of tap water on the flow path in the soft seal gate valve or on the inner peripheral surface of the polyethylene pipe. Polyethylene pipes are connected to both side connection parts of the soft seal gate valve using the connection structure of Patent Document 1, etc., and the soft seal gate valve equipped with a polyethylene insertion port has the advantage that the polyethylene pipe can be directly fusion-connected to this insertion port by EF bonding. It is now widely used in polyethylene pipes for water distribution pipes.

By the way, even though polyethylene pipes have excellent earthquake resistance that allows them to flexibly follow ground movements caused by earthquakes, there is a limit to their permissible bending range, and if the ground movements become large enough, soft seal partitions may be used. A large load is applied to the joint between the valve and the polyethylene pipe, and there is a risk that the joint may be damaged. Water supply is an extremely important infrastructure in modern life, and an essential lifeline for human life. In the event of a major earthquake, if damage occurs at the joint between the soft seal gate valve and the polyethylene pipe, it is difficult to partially repair the damaged part on the gate valve side, so the entire gate valve is damaged. will need to be replaced, and recovery will take time. Therefore, in order to absorb the load on the joint caused by ground movement during an earthquake and prevent damage at the joint between the soft seal gate valve and the polyethylene pipe, the joint between the gate valve and the polyethylene pipe is It is important to provide flexibility and prevent damage to the joint.

In addition, in waterworks, the connection between the polyethylene insertion port of a soft seal gate valve and polyethylene pipe is performed on-site using EF bonding, as described above, but when the polyethylene pipes are fused together, the axes of both sides are aligned. If the axes do not match, or even if the axes match but a displacement load is applied, it may cause poor construction (poor fusion).

Gate valves are installed in places where it is difficult to take up a large space around structures, bridges, intersections, etc., and the installation location is often fixed, so it is difficult to deal with the connection with the polyethylene pipes to which they are connected. , cannot be moved to a position where it is easy to join. In addition, the gate valve body is made of cast iron and is heavy, and does not have the flexibility to easily rotate it in a direction that facilitates connection when fusion-splicing it to a polyethylene pipe. For this reason, when connecting a polyethylene pipe to the polyethylene socket of a soft seal gate valve in waterworks, a socket is provided that can be rotated to align the axis of the polyethylene socket with the axis of the polyethylene pipe. There is a need for soft seal gate valves with improved workability.

Patent Document 2 discloses a flexible ball joint unit that imparts flexibility to a polyethylene pipe line and a piping method using the same unit. In this flexible ball joint, an insertion part whose outer peripheral surface is formed as a convex spherical surface is fitted into a socket part whose inner peripheral surface is formed with a concave spherical surface, so that the insertion part can be rotated with respect to the socket part. When this unit is connected to the polyethylene socket of a soft seal gate valve, flexibility can be given to the piping near the socket.

Patent No. 6033640 Patent No. 5748632

However, in the flexible ball joint unit of Patent Document 2, the concave spherical surface of the socket and the convex spherical surface of the socket are formed to have larger diameters than the socket and the pipe connected to the socket. By forming the diameter of the through hole on the end face of the insertion part on the socket side to be larger than the inner diameter of the connected pipe, the end face of the insertion part on the socket side matches the inner diameter of the pipe when it is flexible. It is constructed so as not to obstruct it. As a result, part of the inner peripheral surface (concave spherical surface) of the socket is always exposed, creating a recessed step on the inner peripheral surface of the pipe. This will cause turbulence in the flow and cause pressure loss.

In addition, iron rust from inside the pipes and valves may adhere to this concave step, causing red water, and foreign matter that has accumulated within the concave step may become jammed when the insertion part is flexible, resulting in earthquake resistance. There is also a risk of harming your 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 not only will the advantages of the current soft-seal gate valve be impaired, but also , there is a risk that it will not be able to exhibit its flexibility in the event of an earthquake.

On the other hand, in the above-mentioned flexible ball joint unit, the joint between the socket and insertion part is exposed to the outside, so when this unit is buried underground, foreign matter such as sand and soil may leak into the joint from the exposed part. There is a possibility that it may get inside from the inside. In this case, there is a risk that foreign matter will be caught between the receptacle part and the insertion part, resulting in poor workmanship and the inability to flex.

The present invention was developed to solve the above-mentioned problems, and its purpose is to provide a resin pipe flexible unit that can be provided with flexibility without sacrificing the advantages of soft seal gate valves. It has a joint structure that uses a flexible resin pipe unit, and has excellent earthquake resistance and workability during waterworks work, and a joint structure and valve that can prevent foreign matter from entering the interior even when buried, and a flexible unit. The purpose of the present invention is 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 with an enlarged diameter at the joint of the joint body, and a resin pipe part is joined to the inner spherical surface of the flexible joint. A joint structure in which a resin pipe flexible unit is flexibly inserted, and a dustproof 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 dustproof cover An annular uneven portion is provided in which the depth of the bellows-like uneven portion is made shallow from the inside along the centripetal direction . An elongated extension cylinder is formed with the inner end of the extension extending along the axial direction of the outer end of the resin pipe, and the insertion hole formed in the inner peripheral surface of the extension cylinder is inserted into the resin pipe. This is a joint structure having a dustproof cover that is brought into circumferential contact with the outer circumferential surface of the resin tube, and is provided with an annular tightening part for tightening the outer circumference of the resin pipe part on the outer circumferential surface of the distal end of the extended cylindrical part.

The invention according to claim 2 is a joint structure having a dustproof cover in which a protrusion is provided at the tip of the inner periphery of the annular tightening part, and the outer periphery of the resin pipe part is held in a tightened state by the protrusion.

The invention according to claim 3 is a flexible soft seal valve in which a joint structure is applied to a valve body of a soft seal gate valve .

According to the invention according to claim 1, the dustproof cover can be attached to the open end of the flexible joint part through the cylindrical part, and after the attachment, the dustproof cover can be attached to the flexible resin pipe part through the annular uneven part. It deforms in a manner that follows the resin pipe, and prevents the generation of a gap with the resin pipe portion, thereby reliably preventing intrusion of foreign matter. In this case, an extending cylindrical portion is provided from the inner circumferential end of the annular uneven portion, and an annular tightening portion for tightening the resin pipe is provided at the tip of this extending cylindrical portion. It prevents foreign matter from entering between the inner circumferential end and the elasticity of the annular uneven part near the inner peripheral edge to maintain the ability to follow the resin pipe when it is flexible. Even if this is done, the influence of hardened soil or sand on the annular clamping part can be suppressed, and the clamping force of the annular clamping part can be reliably maintained and dustproof performance can be achieved.
In particular, when it is flexible, there is no risk of creating a gap between the resin pipe section and the dustproof cover opening, and there is no risk of sand getting in. Furthermore, the circumferential contact between the resin pipe section and the dustproof cover is widened, and the contact surface is Since an annular tightening part is provided on the outer circumferential surface of the tip of the extension tube, it is possible to tighten it reliably, and the other extension tube parts are provided with a degree of freedom, which improves followability. , it is possible to reliably prevent sand and soil from entering the dustproof cover.
Further, according to the invention according to claim 2, not only is it easy to insert the dustproof cover into the resin pipe part, but also the restoring force generated when the diameter of the protrusion is expanded by inserting the resin pipe part is used to make the resin pipe part. Since the outer peripheral surface is strongly gripped to exhibit the dust sealing effect and the braking function, the covered state can be maintained without moving the gripping position of the protrusion.

According to the invention according to claim 3 , the valve, particularly the soft-seal gate valve, can be made flexible by inserting and attaching the resin pipe flexible unit to the flexible joint provided at one end or both ends of the main body. Since the soft-seal gate valve can be constructed, even if the polyethylene pipe connected to the soft-seal gate valve is displaced due to ground movement during an earthquake, the flexible joint follows this displacement and flexes. It absorbs the impact, prevents damage to the joint between the soft seal gate valve and the polyethylene pipe, and maintains the functionality of the water supply, which is an important infrastructure.

In addition, since the flexible joint allows the polyethylene insertion port of the soft seal gate valve to be flexible, there is a gap between the axis of the polyethylene insertion port of the soft seal gate valve and the axis of the polyethylene pipe during connection work. If misalignment occurs, simply rotate and flex the polyethylene insertion port of the soft seal gate valve to align the axis of the polyethylene insertion port of the soft seal gate valve with the axis of the polyethylene pipe. Therefore, poor fusion can be prevented and workability can be greatly improved.

Furthermore, in the flexible joint where the resin tube flexible unit is flexibly inserted and attached, the range of the recessed step (pocket) caused by exposing the inner peripheral surface of the enlarged diameter part is reduced. Pressure loss occurs due to turbulent flow caused by the presence of this concave step, red water occurs due to the inflow of iron rust inside the water pipe that adheres to the inside of the concave step, and foreign matter accumulated inside the concave step It is possible to suppress the occurrence of jamming. Because of this, the bottom of the valve body has a flat, straight structure, so there is no pressure loss, and the soft seal gate valve can be made more flexible without compromising its characteristics of preventing foreign matter from accumulating on the bottom. can do.

FIG. 1 is a sectional view showing an embodiment of a flexible soft seal gate valve according to the present invention. (a) is a drawing showing the left side of the resin tube flexible unit of the present invention, and (b) is a drawing showing the front view. It is a cross-sectional view of FIG. 2(b). It is a drawing showing a ring body. It is a drawing showing a press ring. It is a drawing showing a dustproof cover. It is a drawing explaining the assembly process of the joint structure of this invention. FIG. 3 is an enlarged view of the flexible portion of the joint structure of the present invention (in a fully assembled state). FIG. 2 is an enlarged view of the flexible portion of the joint structure of the present invention (flexible state). It is a drawing which shows another example of a dustproof cover. (a) is an enlarged sectional view of a main part showing a state in which the dustproof cover of FIG. 10 is attached. (b) is an enlarged sectional view of section A in (a). FIG. 12 is an enlarged sectional view of a main part showing a flexible state of the resin tube flexible unit in FIG. 11(a). 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 sectional view of section B in (a). (a) is a partially cutaway front view showing the buried state of the joint portion in FIG. 14; (b) is a partially cutaway front view showing the flexible state of (a).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Below, the resin pipe flexible unit, joint structure, valve, and flexible soft seal gate valve of the present invention will be explained with reference to the drawings. FIG. 1 is a sectional view of an embodiment of a flexible soft seal gate valve, FIG. 2 is a sectional view of a resin tube flexible unit, and FIG. 3 is a sectional view of a resin tube flexible unit.

In FIG. 1, a flexible soft-seal gate valve 11 includes a connection socket 14 at one end of a valve box 13 of a valve body 12, which is a soft-seal gate valve for water supply, and a flexible joint 15 at the other end. ing. A resin pipe 16 is fitted into the outer periphery of the connection socket 14, and a cylindrical tightening ring body 17 is fitted into the outer periphery of the resin pipe 16 to fix the resin pipe 16 to the connection socket 14. In this figure, the valve body 13a is in a position to open the gate valve.

The flexible joint 15 is provided with the joint 18 of the valve body 13 expanded in diameter, and the push ring 23 is attached to the open end 19 with the resin pipe flexible unit 21 inserted from the open end 19. is attached, and the resin tube flexible unit 21 is flexibly accommodated.

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

As shown in FIG. 3, the press-fit sleeve 30 has a flange 29 on the outer end side of a tubular body with a locking part 27 protruding from the outer circumferential surface 26, and a rounded surface on the outer circumferential side of the flange 29. 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.

Note that when the outer circumferential surface of the flange portion 29 of the press-fit sleeve 30 is formed into a rounded surface 28 having approximately the same spherical radius as the spherical surface portion 46 formed on the inner circumferential surface of the flexible joint portion 15, for reasons described later. However, the effects of the present invention can be maximized by forming the outer circumferential surface 26 of the flange 29 into an inclined surface according to the tangential angle thereof, or by forming the flange 29 into a simple flat plate shape with an appropriate thickness. The effects of the present invention can also be obtained, although in a limited manner.

The press-fitting sleeve 30 has an outer diameter slightly smaller on the side into which the resin pipe portion 32 is press-fitted and larger than the inner diameter of the resin pipe portion, and the height of the locking portion 27 protruding from the outer circumferential surface 26 is larger than the resin pipe portion 32. It is formed so that it increases as it approaches the collar part 29 from the side where the pipe part 32 is press-fitted. In addition, a chamfer is provided on the inner periphery of the entrance of the resin pipe part 32, thereby making it easier to press-fit the press-fit sleeve 30 into the resin pipe part 32, and making it difficult for the resin pipe part 32 to come off from the press-fit sleeve 30 after being press-fitted and fixed. It has a certain effect.

By forming a tapered surface 38 on the inner circumferential surface side of the flange 29 of the press-fit sleeve 30, the body passage 39 inside the valve body 12 of the valve box 13 and the inner circumferential passage 40 of the press-fit sleeve 30 are smoothly connected. This suppresses the occurrence of turbulence. Furthermore, the diameter of the inner peripheral flow path 40 of the press-fit sleeve 30 is approximately the same as the inner diameter of the connection socket 14 as shown in FIG. Since the flow channels having substantially the same cross-sectional area are configured to be smoothly continuous, the occurrence of pressure loss can be suppressed.

Note that the opening angle of the tapered surface 38 formed on the inner peripheral surface of the flange 29 of the press-fit sleeve 30 affects securing the flow path area and generating pressure loss during normal use and when flexible. It is necessary to make a decision by sufficiently trading off the influence on these, but even when the resin tube flexible unit 21 is flexible, the body flow path 39 inside the valve body 12 and the inner peripheral flow path 40 of the press-fit sleeve 30 can be maintained as much as possible. In order to connect smoothly and suppress the occurrence of pressure loss, the angle is slightly larger than the flexibility angle θ of the resin tube flexible unit 21, for example, if the flexibility angle of the nominal diameter 75 is 15 degrees, the angle is greater than 15 degrees. 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 mm can be used. In this embodiment, a case is explained in which a polyethylene pipe with a nominal diameter of 75 is used.

As shown in FIG. 4, the outer peripheral surface of the ring body 36 is formed into a ball surface 33, and the inner peripheral surface 34 is provided with a retaining portion 35 and a seal member mounting groove 41. The retaining portion 35 is provided in a portion closer to the surface of the press-fit sleeve 30 that comes into contact with the flange 29 than the seal member mounting groove 41; By substantially opposing the locking portion 27, the resin tube portion 32 is strongly prevented from coming off. This is because the retaining portion 35 is provided in a portion corresponding to the neighboring portion.

Further, since the spherical diameter of the ball surface 33 of the ring body 36 is set to be approximately 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 in a continuous state, forming an outer spherical shape. In this embodiment, the ring body 36 is made of stainless steel (SUS304) and is used without painting. 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 section 32 into which the press-fit sleeve 30 is inserted. Thereby, the ring body 36 can be press-fitted and fixed to the outer periphery of the resin pipe portion 32.

After the press-fitting sleeve 30 is press-fitted into the inner circumferential side of the resin pipe part 32, a ring body 36 with a seal member (O-ring made of nitrile rubber) 42 arranged in the seal member mounting groove 41 is attached to the outer circumferential side of the resin pipe part 32. When press-fitted, as shown in FIG. 3, the locking part 27 protruding from the outer circumferential surface 26 of the press-fitting sleeve 30 bites into the inner circumferential surface 43 of the resin tube part 32, and a recess is formed in the inner circumferential surface 34 of the ring body 36. The outer circumferential surface 37 of the resin pipe part 32 bites into the provided retaining part 35, so that the resin pipe part 32, the press-fit sleeve 30, and the ring body 36 are firmly fixed, thereby forming the integrated resin pipe flexible unit 21. Can be configured.

These press-fitting operations are performed using the same press-fitting machine that is used to press-fit the cylindrical tightening ring body to the outer circumference of the resin pipe, after press-fitting the resin pipe to the outer circumference of the connection socket of the gate valve. Therefore, it does not become a factor that increases manufacturing costs. Note that the arrangement of the retaining portion 35 and the sealing member is arbitrary.

The resin tube flexible unit is not limited to the above structure as long as the resin tube portion 32 can be flexibly inserted into the spherical surface 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 tube flexible unit is joined is applied to the soft seal gate valve 11, it may be applied to valves other than soft seal gate valves.

Next, the flexible joint 15 provided on the other end side of the valve body 13 of the valve body 12 will be explained.
As described above, the flexible joint portion 15 is provided with the joint portion 18 of the valve box 13 expanded in diameter, and has an open end portion 19 and a concave spherical portion 46 on the inner circumferential surface. There is. The spherical diameter of the spherical portion 46 is approximately equal to the spherical diameter of the rounded surface 28 of the flange 29 of the press-fit sleeve 30 and the spherical diameter of the ball surface 33 of the ring body 36.

A stepped portion 48 is provided on the inner circumferential surface of the flexible joint portion 15 following the spherical portion 46 to which a sealing member 47 is mounted. Further, the open end 19 of the flexible joint 15 is provided with bolt holes 52 circumferentially for attaching the press ring 23, and a dustproof cover 61, which will be described later, is secured to 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 press ring 23 is formed into a substantially donut shape with an insertion hole 55 in the center for inserting the resin tube part 32 of the resin tube flexible unit 21, and the outer periphery of the insertion hole 55. Bolt holes 56 are provided in a circumferential manner. Further, as shown in FIG. 5(a), a stepped portion 57 is formed in the thickness direction of the press ring 23, and this stepped portion 57 is inserted into the open end 19 of the flexible joint 15. The press ring 23 can be attached to the open end 19 of the flexible joint 15 with the axis of the press ring 23 aligned with the axis of the press ring 23.

Further, the inner peripheral side of the insertion hole 55 on the side of the stepped portion 57 is formed into a contact radius surface 58, and the spherical surface portion 46 is provided with the spherical diameter of the contact radius surface 58 on the inner peripheral surface of the flexible joint portion 15. 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 part 46 of the flexible joint 15 are aligned with the center. Construct a spherical surface with the same diameter. As described above, the presence of the stepped portion 57 makes it possible to ensure that the axis of the flexible joint 15 and the axis of the press ring 23 are aligned, so that the press ring 23 is simply attached to the open end 19 of the flexible joint 15. You can get this kind of effect 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 end 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 A housing portion for mounting the seal member 47 is formed.

The side opposite to the stepped portion 57 of the insertion hole 55 is formed with an enlarged diameter hole 60 whose diameter increases toward the end surface 59, thereby reducing the flexible region of the resin pipe portion 32 of the resin pipe flexible unit 21 when flexible. At the same time, the flexible range of the resin pipe flexible unit 21 can be restricted at the stage when the resin pipe portion 32 of the resin pipe flexible unit 21 comes into contact with the inner circumferential surface of the enlarged diameter hole 60.

In this embodiment, the press ring 23 is made of spheroidal graphite cast iron (FCD450-10) like the press-fit sleeve 30 described above, 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 it 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 pipe section 32. The dustproof cover 61 is made of a flexible material such as rubber, and has a cylindrical shape with an open end 62 and a bottom 63 as shown in FIG. It is formed by continuously increasing towards the direction. Furthermore, a groove 65 is provided on the inner circumferential side of the open end 62 into which the protrusion 53 that protrudes annularly from the outer circumference of the open end 19 of the flexible joint 15 is inserted.

An insertion hole 66 having a smaller diameter than the outer diameter of the resin tube portion 32 of the resin tube flexible unit 21 is formed in the center of the bottom portion 63 of the dustproof cover 61, and a projection with a pointed tip is formed on the inner periphery of the insertion hole 66. As shown in FIG. 6, a bellows portion 68 is provided concentrically around the insertion hole 66 with a folded portion 67 having a varying depth and width.

By forming a bellows part 68 with varying depth concentrically with the insertion hole 66 on the bottom 63 of the dustproof cover 61, the dustproof cover 61 can be given sufficient elasticity, and the resin when flexible is The dustproof cover 61 is flexibly deformed following the movement of the flexible tube unit 21, and can maintain the covered state. By increasing the depth of the uneven portion of the bellows portion 68, flexibility is improved and the movement of the resin tube flexible unit 21 can be easily followed.

In addition, the side surface 64 of the dustproof cover 61 is formed with a thickness that increases continuously from the bottom 63 toward the open end 62, and the groove 65 is provided on the inner peripheral side of the open end 62 where the thickness increases the most. The groove 65 is difficult to deform and has sufficient holding power, so even if the dustproof cover 61 is deformed when the resin tube flexible unit 21 is flexible, the protrusion 53 continues to be held within the groove 65 and the dustproof cover is 61 can be prevented from coming off from the flexible joint 15.

A thick, annular tightening portion 69 is provided on the insertion hole 66 side of the dustproof cover 61 so as to protrude in the inner circumferential 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 tube portion 32 at a position that does not protrude outward from the bellows portion 68 on the connection port side of the resin tube portion 32 . By providing this tightening portion 69, the diameter of the insertion hole 66 becomes smaller than the outer diameter of the resin pipe portion 32. Therefore, the dustproof cover 61 is attached to the resin pipe portion 32 by enlarging the diameter of the insertion hole 66.

Further, the dustproof cover 61 has a protrusion (lip portion) 67 with a pointed tip on the inner circumferential side of the insertion hole 66 which is formed to have a smaller diameter than the outer diameter of the resin tube portion 32 of the resin tube flexible unit 21. It is set up. This protrusion 67 not only makes it easier to insert the resin tube section 32 of the resin tube flexible unit 21 into the dustproof cover 61, but also provides a restoring force generated by the diameter of the protrusion 67 being expanded by inserting the resin tube section 32. Since the outer circumferential surface 37 of the resin pipe portion 32 is strongly gripped to exert a dust sealing effect and a braking function, even if the resin pipe flexible unit 21 is flexible and the dustproof cover 61 is deformed, the gripping position of the protrusion 67 remains unchanged. It does not move and can maintain the cover state without impairing the dust seal function.

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

Next, referring to FIG. 7, the assembly process of the resin pipe flexible unit and joint structure of the present invention will be explained. The first step is assembling the resin tube flexible unit. In this step, as shown in FIG. 7(a), the flange 29 of the press-fit sleeve 30 is supported by a jig (not shown), and the resin pipe part 32 is pressed to move the press-fit sleeve 30 to the inner peripheral side of the resin pipe part 32. Press fit into. At this time, since the press-fit sleeve 30 is press-fitted while expanding the diameter of the resin pipe part 32, the locking part 27 protruding from the outer peripheral surface 26 of the press-fit sleeve 30 is in a state where it bites into the inner peripheral surface 43 of the resin pipe part 32. It is press-fitted and fixed.

In the next step, as shown in FIG. 7(b), the flange 29 of the press-fit sleeve 30 press-fitted and fixed to the inner peripheral side of the resin tube 32 is supported by a jig (not shown), and a seal is placed in the seal member mounting groove 41. The ring body 36 with the member 42 disposed thereon is press-fitted onto the outer circumferential side of the resin pipe portion 32. At this time, the inner circumferential surface 34 of the ring body 36 is press-fitted while strongly pressing the outer surface of the resin pipe portion 32 whose diameter has been expanded by press-fitting the press-fit sleeve 30. The ring body 36 is press-fitted and fixed to the resin pipe part 32 to which the press-fit sleeve 30 is press-fitted, with the outer circumferential surface 37 of the resin pipe part 32 biting into the retaining part 35 recessed in the ring body. At this time, the locking portion 27 of the press-fit sleeve 30 and the retaining portion 35 of the ring body 36 are arranged at substantially opposing positions, 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 is inserted through the open end 19. Insert into the flexible joint 15. Thereafter, while inserting the resin tube part 32 of the resin tube flexible unit 21 into the insertion hole 55 and inserting the stepped part 57 of the press ring 23 into the open end 19 of the flexible joint part 15, the flexible joint part 15 is inserted. Attach it to the open end 19 of the.

Next, as shown in FIG. 7(d), the bolts 70 are passed through the bolt holes 56 of the push ring 23, and the bolts are screwed into the bolt holes 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 press ring 23 is inserted into the open end 19 of the flexible joint 15, the axis of the flexible joint 15 and the axis of the press ring 23 are surely aligned. In addition, since the push ring 23 is firmly bolted to the open end 19 of the flexible joint 15, the spherical portion 46 of the flexible joint 15 and the abutment radius surface 58 of the push ring 23 are spherical. It is constructed by consecutively arranging concave inner circumferential spherical surfaces with the same spherical diameter.

As described above, the rounded surface 28 of the flange 29 of the press-fit sleeve 30 of the resin tube flexible unit 21 and the ball surface 33 of the ring body 36 form a continuous outer peripheral spherical shape. The spherical portion 46 of the flexible joint 15, the contact radius surface 58 of the push 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 diameter. The inner spherical surface to which the contact radius surface 58 of the push ring 23 is connected can rotate and flexibly rotate the outer spherical surface to which the radius surface 28 of the resin tube flexible unit 21 and the ball surface 33 of the ring body 36 are connected. can be supported. Note that if the press ring 23 is attached to the open end 19 of the flexible joint 15 using a bayonet method, the press ring 23 cannot be attached to the open end 19 in a secure manner, causing play. The surface where the spherical part of the flexible joint and the contact radius surface of the press ring cannot form a correct inner spherical surface, so the rotation and flexibility of the resin pipe flexible unit may be affected, and the resin pipe may When the flexible unit rotates and flexes, it may come off the rotational path and the end face of the ring body may damage the spherical part of the flexible joint.

Note that the method of joining the push ring 23 to the open end 19 of the flexible joint 15 is not limited to the bolting method described above, and the method of joining the press ring 23 to the open end 19 of the flexible joint 15 is not limited to the bolting method described above. 58 are connected in a row to form a correct inner spherical surface. A male screw portion may be formed in the flexible joint portion 15, and the press ring 23 may be screwed onto the flexible joint portion 15.

Finally, by attaching the dustproof cover 61, the resin tube flexible unit 21 is dustproofed without affecting its rotation and flexibility, and foreign objects are prevented from getting caught between the press ring 23 and the ring body 36. be able to.

The details and operation of the joint structure of the present invention will be explained below. FIG. 8 is an enlarged view of the flexible portion of the joint structure of the present invention, showing the state when the assembly is completed. Normally, the joint structure 72 is used in a state where the axis 73 of the flexible joint 15 and the axis 74 of the resin tube flexible unit 21 are aligned, as shown in this figure.

As shown in FIG. 8, the flange 29 of the press-fit sleeve 30 of the resin tube flexible unit 21 is located within the inner spherical surface where the spherical surface 46 of the flexible joint 15 and the contact radius surface 58 of the press ring 23 are connected. The rounded surface 28 and the ball surface 33 of the ring body 36 enclose a continuous outer peripheral spherical surface. The spherical diameter of the inner spherical surface where the spherical part 46 of the flexible joint part 15 and the contact rounded surface 58 of the push ring 23 are connected, and the rounded surface 28 of the collar part 29 of the press-fit sleeve 30 of the resin tube flexible unit 21 and the ring The spherical diameters of the outer peripheral spherical surfaces connected to the ball surfaces 33 of the body 36 are approximately equal and they share the center 75. The abutting rounded surfaces 58 are rotatably and flexibly supported within the continuous inner circumferential spherical surface.

As a result, the resin pipe flexible 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 part 32 of the resin pipe flexible unit 21 is When it is displaced due to fluctuations, it can be rotated and flexible in accordance with the displacement. In this embodiment, the flexibility range 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 press ring 23 is set accordingly.

In addition, during connection work, if the axis of the resin pipe section 32 and the axis of the water pipe (polyethylene pipe) connected thereto do not match, the resin pipe flexible unit 21 can be flexed. By aligning the axial center of the pipe portion 32 with the axial center of the water pipe, poor construction (poor fusion) can be prevented.

The press-fit sleeve 30 has a flange 29 and a rounded surface 28 is formed on the outer peripheral surface of the flange 29, so that the rounded surface 28 of the flange 29 contacts the spherical surface 46 of the flexible joint 15. The range of the recessed step portion (pocket) 78 that occurs when the spherical portion 46 of the flexible joint portion 15 is exposed due to the contact is greatly reduced.

As a result, pressure loss occurs due to turbulent flow caused by the recessed step 78, red water is generated due to the inflow of iron rust inside the water pipe adhering to the inside of the recessed step 78, and foreign matter accumulates inside the recessed step 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 push ring 23, and the contact radius surface 58 of the push ring 23 supports the ball surface 33 of the ring body 36 in a flexible state.

Furthermore, due to the application of fluid pressure, the sealing member 47 disposed on the stepped portion 48 of the flexible joint 15 also moves toward the press ring 23 and remains in close contact with the press ring 23 at the open end 19 of the flexible joint 15. A flexible seal is formed between the inner peripheral side of the ring body 36 and the ring body 36.

Next, the flexible state of the resin tube flexible unit 21 will be explained with reference to FIG. FIG. 9 shows a state in which the resin pipe flexible unit 21 is maximally flexible with respect to the flexible joint 15. As shown in FIG. At this time, the angle θ formed by the axis 73 of the flexible joint 15 and the axis 74 of the resin tube flexible unit 21 is 15 degrees, and the outer peripheral surface of the resin tube portion 32 of the resin tube flexible unit 21 is 23, and further flexibility is restricted.

At this time, the range where the inner circumferential surface of the enlarged diameter hole 60 of the press ring 23 and the outer circumferential surface of the resin pipe part 32 come into contact is the area where the outer circumferential surface 26 of the press-fit sleeve 30 press-fitted and fixed to the inner circumferential side of the resin pipe part 32 exists. Therefore, the force that the resin tube section 32 receives from the inner peripheral surface of the enlarged diameter hole 60 of the press ring 23 due to the flexibility of the resin tube flexible unit 21 is supported by the press-fit sleeve 30, and the force that the resin tube section 32 receives from the inner circumferential surface of the enlarged diameter hole 60 of the press ring 23 is supported by the press-fit sleeve 30, thereby preventing the deformation of the resin tube section 32. can be prevented.

In addition, since the tapered surface 38 is formed on the inner peripheral surface side of the flange 29 of the press-fit sleeve 30, the flow path of the joint portion 18 relative to the body flow path 39 is sharply formed when the resin tube flexible unit 21 is flexible. It is possible to prevent changes in area, suppress pressure loss during flexibility, and secure a flow path.

The influence of the flexibility of the resin tube flexible unit 21 also extends to the dustproof cover 61, but as described above, the bottom part 63 of the dustproof cover 61 is formed with a bellows part 68 with a different depth, so that the dustproof cover 61 is sufficiently Since the dustproof cover 61 is given elasticity, it can be flexibly deformed following the movement of the resin tube flexible unit 21 when it is flexible.

When attaching the dustproof cover 61 to the flexible joint part 15, the groove part 65 of the dustproof cover 61 into which the projection part 53 of the flexible joint part 15 is inserted is provided at the part where the thickness of the side surface 64 increases the most. It is difficult to deform and has sufficient holding power, so that even if the dustproof cover 61 is deformed, the protrusion 53 can continue to be held within the groove 65 without being affected by the deformation.

In addition, the dustproof cover 61 has a protrusion (lip portion) with a pointed tip on the inner circumferential side of the insertion hole 66 formed to have a smaller diameter than the outer diameter of the resin tube portion 32 of the resin tube flexible unit 21. 67 are provided. This protrusion 67 not only makes it easier to insert the resin tube section 32 of the resin tube flexible unit 21 into the dustproof cover 61, but also provides a restoring force generated by the diameter of the protrusion 67 being expanded by inserting the resin tube section 32. Since the outer circumferential surface 37 of the resin pipe portion 32 is strongly gripped to exert a dust sealing effect and a braking function, even if the resin pipe flexible unit 21 is flexible and the dustproof cover 61 is deformed, the gripping position of the protrusion 67 remains unchanged. It does not move and can maintain the cover state without impairing the dust seal function.

Next, another example of the above-mentioned dustproof cover will be explained. FIG. 10 shows another example of the dustproof cover, and FIGS. 11(a) and 12 show the state in which the dustproof cover of FIG. 10 is attached. In addition, hereinafter, parts that are the same as those described before are represented by the same reference numerals, and the description thereof will be omitted.

The dustproof cover 80 in FIG. 10 includes a cylindrical part 81, an annular uneven part 82, an extended cylindrical part 83, and an annular tightening part 84, and, like the dustproof cover 61, the flexible joint part 15 and the open end part 19. installed between.
The cylindrical portion 81 is formed into a substantially cylindrical shape with a diameter that can be attached to the open end portion 19, and an annular uneven portion 82 is provided at the tip of the cylindrical portion 81.

The annular uneven 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, and in this dustproof cover 80, the width W is provided small. As a result, each uneven portion of the annular uneven portion 82 is formed shallowly.

The extending cylindrical portion 83 extends from the inner circumferential end 82a of the annular uneven portion 82 to the outer circumferential surface of the resin pipe portion 32 as shown in FIG. It is formed to extend a length L from the end in the direction of the axis 74 of the resin pipe portion 32. The inner circumferential end 82a is located on the bottom 63 side of the annular uneven portion 82, and by providing the extending cylindrical portion 83 from the inner circumferential end 82a, the contact portion of the extending cylindrical portion 83 with the outer periphery of the resin pipe portion 32 is reduced. 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 cylindrical portion 83, and extends from the bent portion of the resin pipe portion 32 constituted by the annular uneven portion 82 through the extended cylindrical portion 83. and placed in a remote location. This annular tightening part 84 is in a state of protruding toward the outer periphery (outer diameter) side of the extended cylindrical part 83, and has a thickness of approximately half the length of the extended cylindrical part 83 in the direction of the axis 74. formed by The thickness T and length of the annular tightening portion 84 can be set to appropriate sizes.
With the above configuration, the dustproof cover 80 is provided in a shorter length than the dustproof cover 61 described above in the direction of the insertion opening (axis 74).

When installing a dustproof cover with such a structure, when the joint part and the valve are buried in the ground, sand or dirt may be deposited on the concave part on the outside of the annular concavo-convex part (the side that comes in contact with sand or soil). Soil is pushed in and in this state it can become compacted and fixed. In this case, the elasticity of the annular uneven part as a bellows is extremely lost, and when the resin pipe part bends due to external force etc. in this state, the following of the dust-proof cover is inhibited, and the resin pipe part of the dust-proof cover A gap will be created on the contact side, and there is a risk that sand and soil will infiltrate one after another through this gap. As a result, sand and soil enter the joint portion, reducing the flexibility of the resin pipe flexible unit and causing difficulty in returning to the original piping state. This results in a significant loss of functionality and a decrease in commercial value.

On the other hand, in the dustproof cover 80 of this example, as shown in FIGS. 11(a) and 11(b), the extending portion 82b is extended from the inner peripheral end 82a located on the bottom 63 side of the annular uneven portion 82. Further, an extending cylindrical portion 83 is provided to extend along the axial direction of the resin tube portion 32, and an annular tightening portion 84 is provided at the distal end portion of the extending cylindrical portion 32. Therefore, when the resin pipe part 32 is bent in the X direction due to external force, for example, it is less affected by the annular uneven part 82 where sand or soil is compacted, and the annular shape is formed at a position away from the annular uneven part 82. The tightening part 84 tightens the resin pipe part 32, and the annular uneven part 82 near the inner peripheral end 82a and the extension cylinder part 83 extend and bend to follow the flexibility of the resin pipe part 32, thereby tightening the annular part 32. It is possible to reliably prevent the occurrence of a gap between the attaching portion 84 and the resin pipe portion 32. This prevents sand and soil from entering even if the resin pipe flexible unit 21 in FIG. It is hardly affected by this, and dustproofness can be ensured at the contact area between the resin pipe portion 32 and the dustproof cover 80, which requires particularly high followability.

Furthermore, by reducing the width W of the annular uneven portion 82 and making the depth of the uneven portion shallow, the amount of sand or soil pushed into the recessed portion is reduced, thereby reducing the flexibility of the annular uneven portion 82. is suppressed.
Since the extended cylindrical portion 83 is formed into an elongated shape with a length L, and the contact area between the extended cylindrical portion 83 and the resin pipe portion 32 is increased, the extension cylindrical portion 83 can reduce the contact area of the resin pipe portion 32. It becomes possible to improve retention (integrity). By providing the annular tightening portion 84 at approximately half the length of the extended cylindrical portion 83 in the direction of the axis 74, the tightening force by the annular tightening portion 84 is increased, and the length of the other portions increases. The degree of freedom of the entire extended cylindrical portion 83 during flexibility is increased to improve followability.

In this example, since the dustproof cover 80 is provided in a short shape, the attachment length of the dustproof cover 80 in the direction of the axis 74 of the resin pipe portion 32 can be shortened. Thereby, 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 get in the way of the work, increasing work efficiency.

As explained above, the joint structure using the resin tube flexible unit of the present invention reduces the range of the recessed stepped portion that is caused by exposing the inner peripheral surface of the enlarged diameter portion that accommodates the resin tube flexible unit. , a substantially straight flow path can be obtained within the joint structure. Because of this, the bottom of the valve body has a flat, straight structure, so there is no pressure loss, and the soft seal gate valve can be made more flexible without compromising its characteristics of preventing foreign matter from accumulating on the bottom. This is the optimal joint structure for this purpose.

Furthermore, although the above explanation has been made on the assumption that the soft seal gate valve is provided with flexibility and has a polyethylene insertion port with polyethylene pipes connected to both side connection parts, it is not limited to this, and for example, As shown in Fig. 13, it can also be used to give flexibility to one side of a gate valve with a flange structure, and it can also be used to give flexibility to ordinary joints other than gate valves. Of course, it can also be used for other purposes.

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

The resin pipe portion 32 to be connected in this example was made of a polyethylene pipe with a diameter of 50 mm, and the joint portion was housed and buried in a burying box with a dustproof cover 80 attached.
Before embedding the joint portion, a marking line 85 was drawn with a pen on the outer periphery of the resin pipe portion 32 at the end face position of the annular tightening portion 84 as a reference line.

In the state shown in FIG. 14A before burying, the inner peripheral end 82a is located on the bottom 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. In this state, even if the joint part (and the valve) is buried and the sand or soil is tamped down, and the vicinity of the extension cylinder part 83 shifts in the direction of the valve (joint part 18), in FIG. 14(b), There is no possibility that the extending cylinder part 83 or the annular tightening part 84 will enter the annular space G provided between the ring body 36, the press ring 23, and the resin pipe part 32. Therefore, even after embedding, a space G for the entire dustproof cover 80 to be flexible can be secured, and a predetermined flexibility angle θ of the resin pipe flexible unit 21 can be secured.

Next, mountain sand Sa was spread and tamped inside the box, and the joint portion was buried. FIG. 15(a) shows a state in which the joint portion to which the dustproof cover of FIG. 14(a) is attached is buried and tamped.
In this state, a part of the mountain sand Sa on the outer peripheral side of the joint part was dug up 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 part 84 side was shifted by a distance ΔS=10 mm from the initial position shown by the two-dot chain line toward the valve side (arrow side). From these results, it was confirmed that the dustproof cover 80 was compacted with mountain sand Sa during burial, and its opening was pushed approximately 10 mm toward the valve side.

Next, the excavated portion was buried and tamped, and after the resin tube flexible unit 21 was made flexible at a bending angle θ=15 degrees, a portion 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 created in the original position of the resin pipe portion 32 due to the flexibility, the annular uneven portion 82 does not function as a bellows due to the influence of tamping into the concave portion. Function is impaired and movement becomes difficult. However, the annular tightening portion 84 did not substantially deviate from the tightening position immediately after being buried, and no deformation in the diametrical direction was observed.

This is because, on the upper side of the axis 74 in FIG. This is thought to be due to the fact that, on the other hand, the extension tube portion 83 is deformed so as to be bent on the lower side of the axis 74, making it less susceptible to the effects of compaction of the annular uneven portion 82. Due to the functionality of this dustproof cover 80, even if the resin pipe flexible unit 21 is bent due to an earthquake, etc., it is possible to suppress the generation of a gap with the resin pipe part 32 and reliably prevent the infiltration of sand and soil. becomes.

11 Flexible soft seal gate valve 12 Valve body 13 Valve box 15 Flexible joint 18 Joint 19 Open end 21 Flexible resin pipe unit 23 Push ring 27 Locking part 28 Round surface 29 Flange 30 Press-fit sleeve 32 Resin pipe Part 33 Ball surface 35 Retaining part 36 Ring body 42 Seal member 46 Spherical part 58 Contact radius surface 61, 80 Dust 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 with an enlarged diameter is provided at the joint of the joint body, and a resin pipe flexible unit with a resin pipe joined to the inner spherical surface of the flexible joint is flexibly inserted, and the The joint structure has a dustproof cover installed between the open end of the outer circumferential surface of the flexible joint and the resin pipe part, and the dustproof cover has a bellows-shaped uneven portion extending from the inside of the bottom of the cylindrical part in the centripetal direction. An annular uneven part is formed to have a shallow depth, and an extending part is extended from the inner circumferential end of the annular uneven part to the outer circumferential surface of the resin pipe part, and the inner end of this extending part is connected to the outer circumferential surface of the resin pipe part. An elongated extending cylindrical portion is formed along the outer end axial direction, and an insertion hole formed in the inner circumferential surface of the extending cylindrical portion is brought into peripheral surface contact with the outer circumferential surface of the resin pipe portion. A joint structure having a dustproof cover, characterized in that an annular tightening portion for tightening the outer periphery of the resin pipe portion is provided on the outer circumferential surface of the distal end of the extending cylindrical portion . 2. The joint structure having a dustproof cover according to claim 1, wherein a protrusion is provided at the tip of the inner periphery of the annular tightening part, and the protrusion grips the outer periphery of the resin pipe part in a tightened state. A flexible soft seal valve, characterized in that the joint structure according to claim 1 or 2 is applied to a valve body of a soft seal gate valve .

Images