JP3963909B2 - Valve installation method for existing pipe and cutting device used therefor - Google Patents

Description

The present invention provides a valve installation method useful when a new valve is installed in the middle of an existing pipe in a continuous flow (non-continuous water) state while maintaining the flow of fluid in the pipe, or when an old valve is replaced with a new valve, and The present invention relates to an improvement of a cutting device used therefor.

Various methods have been proposed as valve installation methods for existing pipes, and typical methods are as follows (1) and (2).
(1) The existing pipe is provided with a working housing that seals an area slightly wider than the planned cutting position, and the existing pipe is cut to cut the peripheral wall along the circumferential direction of the planned cutting and removal pipe section. A cutting device having a pair of cutting units provided with a cutting tool, a guide support part that rotatably supports the cutting unit around the axis of the tube, and a driving part that drives and rotates the cutting unit is assembled, The existing pipes that are to be left in the left and left pipes can be slidably operated so that both the connecting pipes of the new valve corresponding to the cutting and removing pipes are connected in a concentric manner. In addition, a lifting and lowering holding device for holding and lowering the cutting and removing pipe portion and holding and replacing the replacement valve, and a rising position and a lowering position thereof, Between Assembling the working-off valve for blocking the working housing into an upper space and a lower space.

  Then, by cutting and cutting both cutting units of the cutting device, the cutting tool of each cutting unit is sent inward in the radial direction of the pipe, so that the existing pipe is cut and removed in an undisturbed state while maintaining the flow of the fluid in the pipe. The cut and removed tube portion is lifted into the upper space of the working housing by the lifting and lowering holding device together with the cutting device, and the working on-off valve is closed and held by the lifting and lowering holding device. The cutting and removing pipe part and the cutting device which have been removed are taken out to the outside, and a new valve is attached to the lifting and holding device.

  Next, the work on / off valve is opened and the new valve held by the lifting / lowering holding device is lowered into the lower space of the work housing. Keep the concentric state opposite to the part, and slide the joint unit held in the both cutting residual pipe parts to the new valve side in this state, so that both the cutting residual pipe part and the new valve After connecting and connecting the connecting pipe portion in a concentric state, the lifting / lowering holding device and the working housing are removed (for example, see Patent Documents 1 to 3).

  (2) The existing pipe is fitted with a split valve box that seals an area slightly wider than the planned cutting area, and the tubular valve body insertion port formed on the upper part of the valve box is cut off. A working housing having an upper space in which the removal pipe portion and the valve body can be alternatively stored, and a working on-off valve that shuts the working housing into an upper space and a lower space on the valve box side. At the top of the work housing, a hole saw with a cutting diameter larger than the pipe diameter of the existing pipe, and feeding the hole saw from the upper space in the work housing to the existing pipe cutting completion position in the valve box And a cutting device provided with a drive unit for driving and rotating the hole saw.

  Then, while the work on-off valve is opened, the hole saw of the cutting device is driven to rotate and sent into the valve box, so that the existing pipe can be cut and removed in an undisturbed state while maintaining the flow of the fluid in the pipe. After cutting into a cylindrical shape from above and below in the state of being divided, the cut and removed pipe part is lifted into the upper space of the work housing while being held in the hole saw, and the work on-off valve is closed again. The cutting device is removed from the upper portion of the working housing together with the cutting and removing pipe portion.

  Next, the lifting / lowering holding device attached to the upper part of the working housing has a disc-shaped lid portion that seals the valve body insertion port of the valve box and a valve body that is pressed against the valve seat formed on the inner wall surface of the valve box. After holding the valve body consisting of the part, open the operation on-off valve and lower the valve body part of the valve body held by the lifting and lowering holding device without touching the cut end face of the remaining cutting pipe part Then, the flow path of the existing pipe is blocked by the pressure contact between the valve body and the valve seat of the valve box.

  After that, with the bolts provided at multiple locations in the circumferential direction of the valve body insertion port of the valve box, the valve body is secured to the valve box in a pressed state, and then the valve lid is sealed at the valve body insertion port of the valve box (See Patent Document 3).

Japanese Patent Laid-Open No. 55-44167 JP-A-9-79430 Japanese Patent Laid-Open No. 5-280855

  In the conventional valve installation method according to (1), it is possible to easily cope with the change in the length of the cut and remove pipe portion of the existing pipe by adjusting the distance between the two cutting units constituting the cutting apparatus in the tube axis direction. However, both the connection pipe parts of the new valve corresponding to the cutting and removal pipe part and the cutting residual pipe part are connected in a concentric state to the planned cutting and leaving pipe parts of the existing pipe remaining in the working housing. In order to install a joint unit that can be slidably operated, the working housing becomes larger in the direction of the tube axis as much as the space for assembling both joint units, and a working housing that covers the entire new valve is required. Therefore, it took time and effort to remove the valve after it was installed.

  Further, in the conventional valve installation method according to (2), a split structure valve box that seals an area slightly wider than the planned cutting site is attached to an existing pipe, and the valve body insertion port portion of this valve box, In order to mount the work housing and the work on-off valve, in other words, the valve box of the valve to be installed is also used as a part of the work housing, so the removal work after the valve installation can be done with little effort However, it is necessary to use a hole saw with a cutting diameter larger than the pipe diameter of the existing pipe in order to cut it into a cylindrical shape from above and below in a state where the planned cutting and removal portion of the existing pipe is divided. The flow resistance increases due to the penetration of the hole saw into the pipe, and when the length of the cut-and-removed pipe portion of the existing pipe is shorter than the pipe diameter, the construction cannot be performed, and the application range is limited.

  The present invention has been made in view of the above-described actual situation, and the first main problem is that the efficiency of the removal work after the valve installation and the labor saving are improved, while the cutting and removing pipe portion of the existing pipe is removed. The second problem is to provide a valve installation method for a useful existing pipe that can be reliably and easily constructed even under a condition where the length is shorter than the pipe diameter. The second problem is that the pipe is discharged when the existing pipe is cut. The present invention is to provide an existing pipe installation valve that can efficiently discharge chips and the like and effectively suppress the occurrence of poor sealing due to chips adhering to the valve seat surface.

The first characteristic configuration according to the present invention is such that an existing pipe is provided with a split-structure valve box that encloses a portion to be cut and removed in a sealed state, and can be opened and closed on the valve body insertion port side of the valve box. A cutting tool for attaching an on-off valve, and cutting and removing the existing pipe to be cut and removed in a ring shape with a cutting width smaller than the diameter of the pipe, and the valve box at a position below the pipe to be cut and removed A cutting device having a leg member that is detachably mounted on and supported by the inner bottom wall surface of the valve box in a state of straddling the lower valve seat portion of the valve seat that is formed to protrude from the inner bottom wall surface of the valve box. The pipe part that has been cut and removed is previously attached to the pipe part to be cut and removed, and the cutting and removal part of the existing pipe is cut and removed with a cutting width smaller than the diameter of the existing pipe while being in an uninterrupted flow state. In addition, after taking out the cutting device to the outside through the valve body insertion port of the valve box, A valve body provided with a lid for sealing the valve body insertion port is inserted and fixed between the cut end surfaces of both cutting residual pipe sections, and the pressure contact between the valve body and the valve seat formed on the inner wall surface of the valve box Therefore, the flow path of the existing pipe is blocked.

  According to the above-described characteristic configuration, in a valve box having a divided structure that encloses a planned cutting / removal point of an existing pipe in a sealed state, a valve body insertion port of the valve box that is mounted in advance on the planned cutting / removal pipe part in the valve box With the cutting device inserted through the cutting device, the existing pipe is cut and cut with a cutting width smaller than the diameter of the existing pipe in an uninterrupted state. Take out to the outside through the valve body insertion port and work on-off valve.

  Next, the valve body inserted through the valve body insertion port of the valve box and the working on-off valve is sent between the cut end faces of both the cutting and remaining pipe parts of the existing pipe, and the valve seat is formed on the inner wall surface of the valve box. When the valve body is fixed to the valve box in the pressure contact state, the valve body insertion port of the valve box is sealed with the lid of the valve body, and at the same time, the flow path of the existing pipe is blocked.

  Therefore, the valve box of the valve to be installed can be used as a part of the working housing, and a cutting device that cuts and removes the planned cutting and removal portion of the existing pipe with a cutting width smaller than the pipe diameter is used. With this, the efficiency of the removal work after installation of the valve and saving labor are reduced, but the length of the cutting and removing pipe part of the existing pipe is shorter than the pipe diameter, and the length of the valve box is shorter than the pipe diameter. It can be reliably and easily installed even under conditions.

Further, due to the vortex phenomenon of the fluid generated on the valve seat surface of the lower valve seat portion that is raised from the inner bottom wall surface of the valve box, chips generated by the cutting action by the cutting device accumulate on the valve seat surface. It is possible to effectively suppress this, and it is possible to prevent the occurrence of a sealing failure due to chips adhering to the valve seat surface.

According to a second characteristic configuration of the present invention, both the cutting tools of the cutting device are moved along the pipe circumferential direction at a planned cutting position that is an end face of both of the remaining cutting pipes, so that the existing pipe remains in an undisturbed state. The tube portion to be cut and removed is cut and removed in a ring shape with a cutting width smaller than the diameter of the tube, and at the lower position of both the planned cutting positions of the existing tube, the upstream side of the lower valve seat portion of the valve seat and The configuration is such that chips and the like are discharged from a discharge port provided on the downstream side, and further, the leg member of the cutting device is configured to cover the center side of the lower valve seat portion of the valve seat .

  According to the above-described characteristic configuration, when cutting and removing the existing pipe to be cut and removed with a cutting width smaller than the diameter of the existing pipe while maintaining the uninterrupted flow state, both cutting tools of the cutting device are both left to be cut. Since it cuts in a ring shape while moving along the pipe circumferential direction at the planned cutting position, which is the end face of the cutting tool, the cutting allowance of the cutting tool into the pipe line at the time of cutting is reduced, and the cutting tool enters and moves into the pipe line In addition, the increase in flow resistance caused by the cutting tool can be greatly suppressed, and the amount of chips generated due to the cutting action by the cutting tool can be reduced, and the generated chips can be removed from the existing pipe. Therefore, it is possible to smoothly discharge the chips from the respective outlets provided at the lower positions of both of the scheduled cutting positions, and it is possible to satisfactorily suppress the outflow of chips and the accumulation on the valve seat.

A third characteristic configuration according to the present invention is a cutting device used in the valve installation method for an existing pipe according to claim 1 or 2, wherein the valve box is disposed at a position below the pipe portion to be cut and removed. A leg member is provided that is detachably mounted and supported on the inner bottom wall surface of the valve box in a state of straddling the lower valve seat portion of the valve seat formed so as to protrude from the inner bottom wall surface .

[First Embodiment]
1 to 12 show an example of an existing water pipe 1 buried in the ground, which is an example of an existing pipe, and a gate valve V provided with a flow rate adjustment function (flow rate control function), which is an example of a valve, in an unreserved water state (unless Shows a valve installation facility installed in the flow state) and a valve installation method using the same, and the valve installation facility includes a valve with a split structure that encloses an area a little wider than the planned cut and removal location of the existing water pipe 1 in a sealed state A work housing C having a work open / close valve B that can be freely opened and closed, which forms a work space sealed with the box A and the valve box A, and a cutting bit 4 that is an example of both cutting tools are left behind. Placed in the undisturbed water state by moving it inwardly in the radial direction along the pipe circumferential direction at the planned cutting position, which becomes the end surface 1b of the pipe placement section (previously described as the cutting remaining pipe section before cutting) 1B Cut and removal pipe part of the water pipe 1 (cut and removal pipe part after cutting) A cutting device E that cuts and removes 1A in a ring shape with a cutting width W smaller than its tube diameter D, and a valve body insert of the valve box A together with the cutting device E while holding the cut and removed pipe portion 1A. With respect to the first elevating and holding device F that can be raised and lowered to the upper space S1 in the working housing C through the opening 8 and the working on-off valve B, and the lid portion 2A that seals the valve body insertion port 8 of the valve box A, A valve body 2B that cuts off the flow path at the cut and removed portion of the existing water pipe 1 is integrally formed in a T-shape, and is opposed to the cut openings 1a of both of the remaining cut pipe sections 1B in a concentric state. A valve body 2 in which an auxiliary valve body 3 that can be opened and closed around a longitudinal axis Y along the radial direction passing through the tube axis X is assembled to the valve body 2B, and the valve body 2 is held and held. Between the cutting end face 1b of both cutting residual pipe parts 1B through the valve body insertion port 8 of the valve box A and the work on-off valve B. Second lifting holding device G elevating freely inserting untouched in Les to a predetermined valve body mounting position is provided as main components.

  As shown in FIGS. 3 and 4, the valve box A is in a sealed state with respect to the cutting / removal planned pipe part 1 </ b> A of the existing water pipe 1 and the cutting remaining planned pipe part 1 </ b> B for mounting the valve box continuous on both sides thereof. The lower case 6 having an upward opening that covers from below and the upper case 7 having a downward opening that covers the cutting and removal planned pipe portion 1A and the cutting remaining planned pipe portion 1B in a sealed state from above are provided as main components. The cases 6 and 7 are configured to be integrated by welding at the time of mounting on the existing water pipe 1 at the split mating surface on the virtual horizontal plane passing through the tube axis X of the existing water pipe 1 and the upper case 7. A cylindrical valve body insertion port portion 7B having a valve body insertion port 8 and a connecting flange portion 7A through which the cutting device E and the valve body 2 can be inserted and removed from the vertical direction is integrally formed.

  Further, as shown in FIG. 5, of the integrated cases 6 and 7, there are connecting flanges at the ends of the cylindrical case portions 6 </ b> A and 7 </ b> C that are fitted and held on the outer peripheral surface of the existing water pipe 1. The connecting cylindrical case 9 having a two-divided structure having a tapered surface whose inner diameter increases toward the outer portion 9A is integrally formed by welding, and the connecting flange portion 9A of each connecting cylindrical case 9 is connected to the connecting flange portion 9A. A push ring 11 having a two-part structure for compressing an elastic sealing material 10 interposed between the tapered surface of the cylindrical case 9 and the outer peripheral surface of the existing water pipe 1 from the tube axis X direction includes a plurality of T-bolts 12. The nuts 13 are fastened and fixed. Further, at a plurality of locations in the circumferential direction of each pusher wheel 11, detachment prevention bolts 14 that bite into the outer peripheral surface of the existing water pipe 1 are screwed.

  As shown in FIGS. 4 to 6, in the inner bottom wall surface 6 a of the lower case 6, a portion of the existing water pipe 1 that is located below both scheduled cutting positions is cut by the cutting tools 4 of the cutting device E. A discharge port (drainage port) 16 for discharging the generated chips together with a part of tap water to the outside is formed, and a discharge pipe (drainage tube) 17 communicating with each discharge port 16 can be opened and closed freely. A valve (drain valve) 18 is provided, and a leg member 42 provided on the bottom of the guide support portion E2 of the cutting device E on both sides in the circumferential direction of each discharge port 16 on the inner bottom wall surface 6a of the lower case 6. A cradle 19 is provided for mounting and supporting the detachable from above and below in a fitted state.

The two discharge ports 16 are dispersedly arranged on the upstream side and the downstream side of the valve body 2 in the flow path cut-off state , in other words , dispersed on the upstream side and the downstream side of the lower valve seat portion 20A of the valve seat 20. Since it will be arranged, as shown by the phantom line in FIG. 12, after the cutting by the cutting device E, the two discharge valves 18 are connected to each other by the connecting pipe 57 to be assembled to the valve body 2. When the auxiliary valve body 3 is opened, the pressure difference between the upstream side and the downstream side of the valve body 2 can be reduced by opening both the discharge valves 18, so that the opening and closing operation of the auxiliary valve body 3 can be easily performed with little effort. It can be carried out.

As shown in FIGS. 3 to 5, an elastic sealing material 2 </ b> C provided on the outer peripheral surface of the valve body portion 2 </ b> B of the valve body 2 is pressed against the inner wall surfaces of the integrated cases 6 and 7 to a sealed state. The lower valve seat portion 20A of the valve seat 20 is formed so as to rise above the inner bottom wall surface 6a of the lower case 6, and the lowermost valve seat of the lower valve seat portion 20A is formed. The surface 20 a is disposed at an upper and lower intermediate position between the discharge port 16 formed in the inner bottom wall surface 6 a of the lower case 6 and the lowest end position of the existing water pipe 1.
As shown in FIGS. 2 to 9, the leg member 42 extends over the lower valve seat portion 20 </ b> A of the valve seat 20 formed so as to protrude from the inner bottom wall surface 6 a of the lower case 6. The leg member 42 is mounted and supported on the cradle 19 and is formed with a recessed portion having a downward opening in which the central side of the lower valve seat portion 20A can enter, and covers the central side of the lower valve seat portion 20A. Has been.

  As shown in FIGS. 10 to 12, the inner peripheral surface of the valve body insertion port portion 7 </ b> B of the upper case 7 is pressed to the sealed state with the elastic sealing material 2 </ b> D provided on the outer peripheral surface of the lid portion 2 </ b> A of the valve body 2. The upper corner portion of the lid portion 2A of the valve body 2 is formed in a tapered surface located closer to the center side, and a plurality of circumferential directions of the valve body insertion port portion 7B of the upper case 7 are formed. At the location, when the valve body 2 is in a valve body mounting position where the flow path is blocked, the valve body 2 is pressed against the valve seat 20 of the valve box A in a state where it is secured and fixed so that the lid 2A of the valve body 2 is closed. A presser bolt 21 having a tapered pressing surface for pressing the tapered surface downward is formed on the tip side and is screwed in from the horizontal direction.

  As shown in FIGS. 11 and 12, when the valve body 2 is pressed and fixed to the valve seat 20 of the valve box A, the connection flange portion 7 </ b> A of the valve body insertion port portion 7 </ b> B of the upper case 7 has A valve lid 22 for sealing the valve body insertion port 8 of the valve box A is fixedly connected in a sealed state via bolts 27 and nuts 28, and an upper valve of the valve body 2 is provided at the center of the valve lid 22. A bearing portion 22A for supporting the shaft portion 2E is formed, and an operating shaft of the operating means 5 for opening and closing the auxiliary valve body 3 from the outside of the valve box A is connected to the connecting flange portion 22B formed at the upper end of the bearing portion 22A. A reduction gear 15 that is detachably linked to 5A from above and below is attached.

  As shown in FIG. 11, the operating means 5 is formed at both upper and lower end portions of the auxiliary valve body 3 in order to support the auxiliary valve body 3 so as to be rotatable around the longitudinal axis Y with respect to the valve body 2. Among the rotating fulcrum shafts, the upper rotating fulcrum shaft is integrally formed with the operating shaft 5A, and the upper surface of the speed reducer 15 is connected to the operating shaft 5A of the operating means 5 via a reduction gear mechanism. Rotating operation shaft 15A that interlocks with each other is projected.

  As shown in FIGS. 6 to 9, the working housing C is configured by alternately connecting the cutting device E and the valve body 2 to the connecting flange portion 7 </ b> A of the valve box A and the internal space of the valve box A. A lower connecting flange portion 23A of the first housing portion 23 that forms a lower space S2 that can be stored in the housing is fixedly connected via a bolt 27 and a nut 28, and the upper connecting flange portion 23B of the first housing portion 23 has a work The lower connecting flange portion 24A of the second housing portion 24 having the on-off valve B is fixedly connected in a sealed state via bolts 27 and nuts 28, and the upper connecting flange portion 24B of the second housing portion 24 includes The lower connecting flange portion 25A of the third housing portion 25 that forms an upper space S1 that can alternatively accommodate the cutting device E and the valve body 2 is fixedly connected in a sealed state via bolts 27 and nuts 28. Further, the upper connecting flange portion 25B of the third housing portion 25 supports the elevating cylinder shaft 29 of the first elevating / holding device F or the elevating tube shaft 29 of the second elevating / holding device G so as to be slidable in the vertical direction. The lower connecting flange portion 26A of the lid cover 26 is fixedly connected in a sealed state via bolts 27 and nuts 28.

  As shown in FIGS. 3 and 5 to 9, the cutting device E is a cutting tool 4 that cuts along the pipe circumferential direction at a planned cutting position that is an end face of both of the remaining cutting pipe portions 1 </ b> B of the existing water pipe 1. And a pair of left and right sprocket wheels 31 equipped with the cutting unit E1, and a pair of left and right guides that are fitted and supported rotatably around the tube axis X of the existing water pipe 1. It comprises a disk 30 and a guide support part E2 having a two-part structure that is externally fixed to the cut and removal planned pipe part 1A of the existing water pipe 1, and a drive part E3 that drives and rotates both sprocket wheels 31. Yes.

  Each cutting unit E1 includes a sliding guide portion 34 for slidably guiding a cutting tool holder 33 for detachably holding the cutting tool 4 in a pipe radial direction to a mounting part 32 provided on the sprocket wheel 31; The feed screw shaft 35 is united by the engagement of the feed screw shaft 35 for sliding the tool holder 33 along the guide portion 34 and the engagement member 36 provided on the guide support portion E2 on the side of the rotation path of the cutting unit E1. A passive rotating body 37 that provides rotation corresponding to the feed amount is provided.

  The drive part E3 is driven and rotated around an axis parallel to the pipe axis X of the existing water pipe 1 in conjunction with the input shaft 38 which is rotatable around the vertical axis Y at the upper part of the guide support part E2. A transmission case 40 having a pair of left and right drive sprockets 39 is provided, and a transmission chain 41 is wound around each drive sprocket 39 and each sprocket wheel 31 located on the same side thereof.

  The first elevating / holding device F and the second elevating / holding device G have the same structure, and the lower end portion of each elevating cylinder shaft 29 has a transmission case 40 of the cutting device E or the upper valve shaft portion of the valve body 2. A connecting portion 44 that is fixedly connected in a state that can be selectively hung with respect to 2E is provided, and a transmission shaft that transmits power to the input shaft 38 of the cutting device E is provided in each lifting cylinder shaft 29. (Not shown) is provided, and an electric motor 45 for driving the transmission shaft is detachably provided at the upper end of each lifting cylinder shaft 29.

  Each of the front and back both surfaces of the auxiliary valve body 3 assembled to the valve body 2 is configured as a partial spherical surface from which the tube axis X side of the existing water pipe 1 protrudes most.

  As shown in FIGS. 6 to 9, the working on-off valve B includes a horizontally slidable gate valve body 46 that shuts off the internal passage of the second housing portion 24 in a sealed state, and a gate valve body 46. An operation handle 48 that opens and closes via a screwed shaft 47 is configured.

Next, a valve installation method using the valve installation facility configured as described above will be described.
As shown in FIG. 1, a work pit P is formed by excavating a work area including a valve installation position of an existing water pipe 1 buried in the ground, and a base concrete 50 containing a reinforcing bar is formed at the bottom of the work pit P. Is constructed, and reinforcing column concrete 51 containing reinforcing bars for maintaining the concentric state after cutting both the cut and left pipe portions 1B of the existing water pipe 1 is constructed.

As shown in FIG. 2, the sprocket wheel 31 and the like provided with a two-piece structure guide support portion E2 and a plurality of cutting units E1 constituting the cutting device E are assembled to the cutting and removal planned pipe portion 1A of the existing water pipe 1. .
At this time, the mounting interval in the tube axis direction of the cutting tool 4 of the cutting unit E1 equipped in both sprocket wheels 31 is set to a predetermined cutting width W narrower than the pipe diameter D of the existing water pipe 1. .

  As shown in FIGS. 3 and 4, a cutting device E is configured with respect to the cutting and removal planned pipe portion 1A of the existing water pipe 1 and the cutting remaining planned pipe portion 1B for mounting the valve box continuous on both sides thereof. In a state of covering the guide support portion E2 and the cutting unit E1 etc. of the divided structure, the lower case 6 of the upward opening and the upper case 7 of the downward opening constituting the valve box A are mounted, and both the cases 6, 7 are attached. In the split joint surface on the virtual horizontal plane passing through the tube axis X of the existing water pipe 1, it is integrated by welding when mounted on the existing water pipe 1, and among the integrated cases 6 and 7, the existing water pipe 1 In the connecting cylindrical case 9 integrated by welding to the ends of both cylindrical case parts 6A and 7C that are externally fitted and held on the outer peripheral surface of the connecting cylindrical case 9, the tapered surface of the connecting cylindrical case 9 and the existing water pipe 1 The elastic sealing material 10 interposed between the outer peripheral surface and the tube axis X The push ring 11 of the two-part structure that compresses from the direction is fastened and fixed, and the detachment prevention bolts 14 screwed into a plurality of locations in the circumferential direction of each push ring 11 are fixedly operated while being bitten into the outer peripheral surface of the existing water pipe 1. Then, the valve box A is tightly retained and fixed to the planned cutting remaining pipe portion 1B of the existing water pipe 1 in a sealed state.

As shown in FIG. 5, the lower connection flange portion 52A of the hydraulic pressure test cover 52 is fixedly connected to the connection flange portion 7A of the upper case 7 through bolts 27 and nuts 28 in a sealed state. A water pressure gauge 53 and a pressure water supply pipe 55 provided with a water pressure pump 54 are connected to 52, and water leakage from the valve box A is tested.
When it is confirmed that there is no water leakage, the test water in the valve box A and the water pressure test cover 52 is discharged to the outside through both discharge ports 16 formed in the inner bottom wall surface 6a of the lower case 6, and then the upper case 7 is connected. The water pressure test cover 52 is removed from the flange portion 7A.

  As shown in FIGS. 6 and 7, the connecting flange portion 7 </ b> A of the upper case 7 has a first housing portion 23 constituting the working housing C, a second housing portion 24 provided with the working on-off valve B, and a cutting device E. And the third housing portion 25 and the lid cover 26 that form an upper space S1 that can alternatively accommodate the valve body 2 in a sealed state, and the lifting cylinder shaft 29 of the first lifting holding device F is The lid cover 26 is penetrated and supported, and the connecting portion 44 of the lifting cylinder shaft 29 and the transmission case 40 of the cutting device E are fixedly connected.

  Further, a transmission shaft (not shown) provided in each lifting cylinder shaft 29 and an input shaft 38 of the cutting device E are interlocked and connected, and the transmission is transmitted to the upper portion of the lifting cylinder shaft 29 of the first lifting / lowering holding device F. An electric motor 45 for driving the shaft is attached.

  Next, when the electric motor 45 is started, both the sprocket wheels 31 equipped with the cutting unit E1 are driven to rotate through the transmission shaft in the lifting cylinder shaft 29, the input shaft 3, the pair of left and right drive sprockets 39, and the transmission chain 41. The cutting tool 4 mounted on the tool holder 33 slidable in the pipe radial direction with respect to the sliding guide part 34 of each sprocket wheel 31 is scheduled to be cut to become the end face 1b of both of the remaining cutting pipe parts 1B. The passive rotating body 37 of the feed screw shaft 35 that moves along the pipe circumferential direction at the position and slides the tool holder 33 is engaged with the engaging member 36 provided on the guide support portion E2 beside the rotation path of the cutting unit E1. In this case, rotation corresponding to the unit feed amount is applied to the feed screw shaft 35, and the cutting tool 4 is fed by the unit feed amount inward in the pipe radial direction.

  Thus, by moving the cutting tool 4 while feeding it radially inward along the circumferential direction of the pipe at the planned cutting position that becomes the end face 1b of both of the remaining cutting pipes 1B, the existing water pipe 1 remains in an undisturbed state. 1A can be cut and removed in a ring shape with a cutting width W smaller than its tube diameter D.

  At this time, by opening both the discharge valves 18, chips and the like generated by the cutting action of the cutting tool 4 by the cutting tool 4 are disposed at the respective positions below the planned cutting positions of the existing water pipe 1. Since each can be smoothly discharged from the outlet 16, the outflow of chips and the like to the downstream side and the accumulation on the lower valve seat portion 20A of the valve seat 20 can be satisfactorily suppressed.

  Further, since the cutting tool 4 of the cutting device E is cut in a ring shape while being moved along the pipe circumferential direction at the planned cutting position that becomes the end surface 1b of both of the remaining cutting pipe portions 1B, the cutting that occurs with the cutting action is performed. The amount of generated waste can be reduced, and the protrusion margin of the two cutting tools 4 into the pipe line at the time of cutting is small, and an increase in the flow resistance of tap water can be suppressed.

  As shown in FIGS. 8 and 9, the lifting cylinder shaft 29 of the first lifting / lowering holding device F is lifted by the lifting means such as a crane with respect to the lid cover 26 of the working housing C, and the cutting device E is cut and removed. After taking out into the upper space S1 of the working housing C together with 1A, the working on-off valve B is closed to connect the upper connecting flange portion 25B of the third housing portion 25 and the lower connecting flange portion 26A of the lid cover 26. And the cutting device E is removed to the outside together with the cutting / removing tube portion 1A and the lid cover 26.

  Next, the elevating cylinder shaft 29 of the second elevating / holding device G is passed through the lid cover 26 and the connecting portion 44 of the elevating cylinder shaft 29 and the valve body 2 are fixedly connected, and then the valve body 2 and the lid cover 26 are attached. The valve body 2 is lifted by lifting means such as a crane, the valve body 2 is inserted into the third housing part 25 of the working housing C, and the upper connecting flange part 25B of the third housing part 25 and the lower connecting flange part 26A of the lid cover 26 are connected. Securely connect in a sealed state.

  As shown in FIGS. 9 and 10, the work on-off valve B is opened and the lifting cylinder shaft 29 of the second lifting / lowering holding device G is lowered by the lifting means such as a crane with respect to the lid cover 26 of the working housing C. Then, the valve body 2 is inserted up to a predetermined valve body mounting position without touching the cut end face 1b of the both cutting residual pipe portions 1B through the valve opening 8 of the work on-off valve B and the valve box A.

  In this state, the elastic sealing material 2D provided on the outer peripheral surface of the lid portion 2A of the valve body 2 is pressed against the inner peripheral surface of the valve body insertion port portion 7B of the upper case 7 in a sealed state, and the valve body 2 The elastic sealing material 2C provided on the outer peripheral surface of the valve body portion 2B is pressed in a sealed state on the valve seat 20 formed on the inner wall surfaces of the integrated cases 6 and 7, and the existing water pipe 1 is cut and removed. The flow path is blocked at the location.

  Next, as shown in FIG. 10, when the presser bolts 21 that are screwed and attached to a plurality of locations in the circumferential direction of the valve body insertion port portion 7 </ b> B of the upper case 7 are tightened radially inward, the presser bolts 21. The taper-shaped pressing surface formed on the front end side of the valve body comes into contact with the tapered surface formed on the upper corner portion of the lid portion 2A of the valve body 2 from the horizontal direction, and the valve body 2 is the valve seat of the valve box A. In a state where it is pressed by 20, it is fixed and secured.

  As shown in FIGS. 10 to 12, the fixed connection between the connecting flange portion 7 </ b> A of the upper case 7 and the lower connecting flange portion 23 </ b> A of the first housing portion 23 is released, and the working housing C and the second lifting and lowering holding device G are released. The valve lid 22 for sealing the valve body insertion port 8 of the valve box A is fixedly connected to the connection flange portion 7A of the upper case 7 via a bolt 27 and a nut 28, and the bearing of the valve lid 22 is further supported. A speed reducer 15 that is detachably linked to the operation shaft 5A of the operation means 5 for opening / closing the auxiliary valve body 3 from the outside of the valve box A is connected to the connecting flange portion 22B formed at the upper end of the portion 22A. Install.

  Further, not only can the flow rate be reliably and easily adjusted by opening / closing the auxiliary valve body 3 while the valve body 2 is maintained in the flow path shutoff posture, but the auxiliary valve body 3 has the same inner diameter as the existing water pipe 1. Even if it is configured to have a diameter or a slightly larger diameter, the internal space on the side of the cutting opening 1a in each cutting residual pipe portion 1B can be sufficiently utilized as an operating space for rotating and opening the auxiliary valve body 3. Even under conditions where the minimum gap (cutting width W) between the cut end faces 1b of both cut residual pipe portions 1B is considerably smaller than the pipe diameter D, the flow rate can be reliably and easily adjusted in a compact and efficient manner. In addition, the flow resistance when the auxiliary valve body 3 is in the maximum opening operation position can be reduced.

  Moreover, not only can the operating shaft 5A of the operating means 5 for opening and closing the auxiliary valve body 3 be easily operated with a small operating force, but the speed reducer 15 for this purpose can be used as the upper valve shaft portion 2E of the valve body 2. Can be mounted using the valve lid 22 that seals the valve body insertion port 8 of the valve box A, and the mounting structure can be simplified.

[Other Embodiments]
(1) In the first embodiment described above, a cutting tool is used as the cutting tool 4 of the cutting device E. However, instead of this, a disc-shaped cutting tool or an end meal is used, and both cutting residual pipe portions 1B are used. By moving the pipe in the radial direction along the pipe circumferential direction at the planned cutting position, which is the end face of the pipe, the pipe part 1A to be cut and removed from the existing water pipe 1 in an undisturbed state is kept from its pipe diameter D. You may comprise so that it may cut | disconnect in a ring shape with the cutting width W small.

  (2) In each of the embodiments described above, the valve box A is divided into two in the circumferential direction, but may be divided into three or more in the circumferential direction.

(3) In the first embodiment described above, a portion of the valve body 2 that is concentrically opposed to the cutting opening 1a of both of the remaining cutting tubes 1B is along the radial direction passing through the tube axis X. Although the auxiliary valve body 3 that can be rotated and opened around the vertical axis Y is assembled, the auxiliary valve body 3 may be assembled to the valve body 2 in a state that can be opened and closed by sliding in the vertical direction.
In the first embodiment described above, the auxiliary valve body 3 is configured to have the same or substantially the same outer diameter as the inner diameter of the existing water pipe 1, but the auxiliary valve body 3 is smaller than the inner diameter of the existing water pipe 1. It may be configured and implemented.
Furthermore, you may implement using the valve body 2 in which such an auxiliary valve body 3 is not provided.

  (4) In the first embodiment described above, the two cases 6 and 7 constituting the valve box A are attached to the existing water pipe 1 on the split mating surface on the virtual horizontal plane passing through the tube axis X of the existing water pipe 1. Although sometimes configured to be integrated by welding, the two cases 6 and 7 may be configured to be flange-joined.

  (5) In the first embodiment described above, the valve body 2 is not touched between the cut end faces 1b of the two cut residual pipe portions 1B through the valve body insertion port 8 of the valve box A and the work on-off valve B. Although it is configured to be inserted up to a predetermined valve body mounting position, no burrs or the like are generated on the cut end face 1b of both of the cutting residual pipe portions 1B, and the valve body 2 or the auxiliary valve body 3 is applied. When not seriously damaging the sealing material, a part or the whole of the cut end face 1b of both of the cut remaining pipe portions 1B may be used as the lifting guide portion of the valve body 2.

Sectional side view at the time of working pit excavation showing the first embodiment of the valve installation method of the present invention Cross-sectional side view with cutting device installed Exploded sectional front view when assembling both cases of the valve box with the cutting device covered Cross-sectional front view when welding both cases of the valve box with the cutting device covered Cross-sectional side view during water pressure test Cross-sectional side view before connecting the cutting device and the first lifting / lowering holding device Cross-sectional side view when cutting Sectional side view when the cutting device is taken out into the upper space of the working housing together with the cutting and removing pipe portion Cross-sectional side view when replacing the cutting device and valve body Cross-sectional side view when the valve body is fixed and the work housing is removed Cross-sectional side view of the main part just before mounting the reducer on the valve body Cross-sectional side view when the reducer is attached to the valve disc

Explanation of symbols

A Valve box B Work on-off valve E Cutting device D Pipe diameter (outer diameter)
W Cutting width 1 Existing pipe (existing water pipe)
1A Cutting / removing tube (cutting / removal planned tube)
1B Cutting and leaving pipe (cutting and leaving planned pipe)
1a Cutting opening 1b Cutting end face 2 Valve body 2A Lid 2B Valve body 2E Upper valve stem 3 Auxiliary valve body 4 Cutting tool (cutting tool)
5 Operation means 5A Operation shaft 6a Inner bottom wall surface 8 Valve element insertion port 15 Reducer 16 Discharge port 20 Valve seat 20A Lower valve seat portion 20a Lowermost valve seat surface

Claims (3)

Fitted with a valve body of divided structure surrounding its cut and removed planned portion sealingly into the existing pipe, is attached to opening and closing freely work off valve the valve body insertion opening side of the valve casing, said existing pipe A cutting tool for cutting and removing the cutting and removal planned pipe part in a ring shape with a cutting width smaller than the diameter of the pipe, and a lower part of the cutting and removing planned pipe part formed above the inner bottom wall surface of the valve box A cutting device provided with a leg member that is detachably mounted and supported on the inner bottom wall surface of the valve box in a state of straddling the lower valve seat part of the valve seat , is attached in advance to the cutting and removal planned pipe part in the valve box , This cutting device cuts and removes the planned cutting and removal portion of the existing pipe with a cutting width smaller than the diameter of the existing pipe while maintaining the undisturbed flow state, and inserts the cutting device together with the cut and removed pipe portion into the valve body valve body. After removing it through the mouth, remove the lid that seals the valve body insertion port of the valve box. The inserted valve body is inserted and fixed between the cut end faces of both of the remaining cutting pipe parts, and the flow path of the existing pipe is blocked by the pressure contact between the valve body and the valve seat formed on the inner wall surface of the valve box. The valve installation method for existing pipes. By moving the two cutting tools of the cutting device along the pipe circumferential direction at the planned cutting position which is the end face of both of the remaining cutting pipe parts, the existing pipes to be cut and removed can be removed from the existing pipes in an uninterrupted state. Cut and remove in a ring shape with a cutting width smaller than the diameter, and chips from the outlets provided on the upstream side and downstream side of the lower valve seat part of the valve seat at the lower position of both scheduled cutting positions of the existing pipe The valve installation method for an existing pipe according to claim 1 or 2 , wherein the central part of the lower valve seat portion of the valve seat is covered with a leg member of the cutting device. . It is a cutting device used for the valve installation method of the existing pipe of Claim 1 or Claim 2 , Comprising: The valve raised from the inner bottom wall surface of the said valve box in the downward position of the said cutting-and-removal planned pipe part A cutting device provided with a leg member that is detachably mounted and supported on the inner bottom wall surface of the valve box in a state of straddling the lower valve seat portion of the seat .

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