JP2012172731A - Gate valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gate valve having an upper cover that can be fixed or dismantled by easy work without requiring tightening work of rotating a member.SOLUTION: The gate valve has a valve case which constitutes a part of pipeline, a valve body which displaces between the close position to block the channel in the valve case and the open position which opens this channel, a valve stem 23 which can operate the displacement of the valve body, and a valve cover 25 which rotatably supports the valve stem 23. The valve cover 25 has a bush 16 which is inserted into an opening part on the top face of the valve cover 25 and supports the valve stem 23 from the top face, and an upper cover 17 to cover the bush 16 and block the opening. The bush 16 is engaged to the opening part by a bayonet mechanism. The caulking projection 16c, which is prepared in the bush 16, is inserted into the through hole 17a formed in the upper cover 17, and the upper cover 17 is fixed to the bush 16 by caulking the caulking projection 16c.

Description

  The present invention relates to a gate valve used for a fluid pipe such as water supply.

  In recent years, in branch pipe connection work in which a branch pipe is provided in the middle of an existing fluid pipe such as a water pipe, the peripheral wall of the fluid pipe is perforated while maintaining the state of uninterrupted water without stopping the pipe on the upstream side, A method of connecting branch pipes is used. In such a construction method, a branch valve having a built-in valve that displaces the flow path in the valve box in an openable / closable manner according to the operation of the valve shaft, and a branch case mounted around the perforated portion of the fluid pipe. A pipe connection device is used, and a branch pipe is connected to the branch case with a gate valve interposed therebetween.

  Patent Document 1 by the present applicant discloses a branch pipe provided with a bifurcated case 91 divided into upper and lower parts and a gate valve 92 that is connected with its end portion sandwiched between the split surfaces of the branch case 91 as shown in FIG. A connection device is disclosed. In this device, the split surface 90 of the branch case 91 is positioned in a substantially horizontal direction, and the branch case 91 and the gate valve 92 are connected by fastening of the split surface 90. Therefore, a large load in the pipe axis direction due to ground fluctuation or the like. Even if acted, the load is less likely to act in the direction in which the bolt of the fastener 98 extends, and the opening of the branch case 91 can be suppressed to effectively prevent fluid leakage.

  At the time of construction, as shown in FIG. 21, a punching device 96 is connected to the gate valve 92 and the valve body 93 is raised, and then the cutter 97 is advanced to punch the peripheral wall of the water pipe K. When the drilling is completed, the cutter 97 is moved backward, the valve body 93 is lowered, and the inside of the gate valve 92 is shut off. Subsequently, the punching device 96 is removed from the gate valve 92, and a branch pipe (not shown) is connected instead. Then, if the valve body 93 is raised and the inside of the gate valve 92 is opened, water flows from the water pipe K to the branch pipe. According to such a construction method, since the branch pipe can be connected to the existing water pipe without water interruption, it is excellent in convenience.

  The gate valve 92 is displaced between a valve box 94 constituting a part of the pipe line, a closed position (see FIG. 21) that blocks the flow path in the valve box 94, and an open position that opens the flow path. It has a valve body 93, a valve shaft 95 capable of operating the displacement of the valve body 93, and a valve lid 99 incorporating the valve shaft 95. The valve body 93 is formed by lining a thick seal rubber on the entire surface of the box-shaped body 93a, and the thickness T9 in the tube axis direction tends to increase. Is greatly secured.

  By the way, in the soft seal gate valve 92 as described above, the valve lid 99 rotatably supports the valve shaft 95, and is configured so that the valve body 93 can be displaced in accordance with the rotation operation of the valve shaft 95. Yes. An opening is provided on the top surface of the valve lid 99, and an upper lid is attached so as to shield the opening with the top of the valve shaft 95 protruding. Conventionally, a method of fastening with a plurality of bolts as disclosed in Patent Documents 2 and 3 is adopted for fixing the upper lid, but there is a problem that it takes time to tighten the bolts.

  In the gate valve described in Patent Document 4, instead of a method of fastening with a plurality of bolts, a packing box that rotatably supports the valve shaft is built in, and a method of screwing the packing box to an upper lid or a presser lid is used. Adopted. However, also in this gate valve, the operation | work which rotates and fastens a member is still required, and it will take an effort correspondingly. In addition, since the outer peripheral surface of the packing box and the inner peripheral surfaces of the upper lid and the presser lid must be threaded, the manufacturing cost tends to increase.

  In a shut-off armature (corresponding to a gate valve) described in Patent Document 5, a bearing collar projecting on a spindle is sandwiched between a bearing flange and a seal support, and the seal support is locked by a bayonet mechanism to form a neck ring (upper cover). It is configured to be surrounded by However, in this apparatus, since the neck ring is locked by the hook-shaped spring arm, the work of disassembling the neck ring tends to be complicated. Further, the seal support may rotate together with the rotation of the spindle, and it is considered that there is a problem in safety during disassembly.

JP 2007-309474 A JP 2008-95795 A Japanese Utility Model Publication No. 55-127169 Japanese Utility Model Publication No. 04-117264 JP 2005-535839 A

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a gate valve that does not require an operation of rotating and tightening a member, and can easily fix and disassemble the upper lid. It is in.

  The above object can be achieved by the present invention as described below. That is, the gate valve according to the present invention is a valve that is displaced between a valve box that forms a part of a pipe line, a closed position that blocks a flow path in the valve box, and an open position that opens the flow path. In a gate valve having a body, a valve shaft capable of operating the displacement of the valve body, and a valve lid that rotatably supports the valve shaft, the valve lid is an opening provided on a top surface of the valve lid A bush that is fitted in a portion and supports the valve shaft from the top surface side, and an upper lid that covers the bush and shields the opening, and the bush is locked to the opening by a bayonet mechanism, The upper lid is fixed to the bush by inserting a caulking projection provided in the bush into a through hole formed in the upper lid and caulking the caulking projection.

  In this gate valve, the bush that supports the valve shaft from the top side is locked to the opening of the valve lid by the bayonet mechanism, and the upper lid is fixed to the bush by caulking the caulking projection of the bush. When fixing, the work of rotating and tightening the member is not required. In addition, there is no need for threading, which reduces manufacturing costs. Further, when disassembling the upper lid, it is only necessary to grind the caulked portion of the caulking projection with a grinder or the like, and it can be performed easily.

  In the gate valve of the present invention, the bayonet mechanism locks the first overhanging portion formed on the inner peripheral surface of the opening and the second overhanging portion formed on the outer peripheral surface of the bush. A notch that allows the second overhanging portion to enter is formed on the inner peripheral surface of the opening, and the bushing is formed by inserting a rotation prevention protrusion provided on the upper lid into the notch. It is preferable that it is configured to prevent the rotation.

  As a result, it is possible to prevent the bushes from rotating together with the rotation of the valve shaft, and to ensure safety when the upper lid is disassembled. That is, if the structure allows the bushes to rotate together, the lock of the bush by the bayonet mechanism will be released without noticing it, and the valve shaft will come out unexpectedly when the upper lid is disassembled, which is dangerous. According to the above configuration of the invention, such a situation can be prevented and the dismantling operation can be easily performed.

  In the gate valve of the present invention, a cylindrical collar is fitted into the opening, and a flange provided on the valve shaft is sandwiched between the bush and the collar so as to rotatably support the valve shaft. Is preferred. With this configuration, the valve shaft can be supported so as to rotate stably and smoothly.

The longitudinal cross-sectional view which shows an example of the branch pipe connection apparatus provided with the gate valve which concerns on this invention Cross-sectional view of the main part showing the valve body in the closed position Longitudinal sectional view showing the periphery of the top surface of the valve lid that supports the valve stem XX arrow sectional view of FIG. (A) plan view and (b) longitudinal sectional view showing the periphery of the top surface of the valve lid (A) Top view and (b) Front view half sectional view of bush (A) Front view half sectional view and (b) Bottom view of the top lid Longitudinal sectional view showing the state before fixing the upper lid Side view of gate valve and plan view of lock pin Front view of valve lid Longitudinal sectional view of gate valve showing joint part of valve box and valve lid Longitudinal sectional view showing a modification of the joint part between the valve box and the valve lid The figure which shows the state before compression of the sealing material of FIG. (A) Front view, (b) Rear view, and (c) Longitudinal sectional view of the valve body Sectional drawing which shows the state of (a) just before the completion of the transition to the closed position of the valve body and (b) the state of the completion of the transition Cross-sectional view of the main part showing the protrusion entering the notch Cross-sectional view of the main part showing the valve body when moving to the open position The figure which shows the state which connected the punching device to the gate valve Sectional drawing which shows the principal part which shows the gate valve which concerns on another embodiment of this invention. 19A is a front view, FIG. 19B is a rear view, and FIG. 19C is a longitudinal sectional view. The longitudinal cross-sectional view which shows the branch pipe connection apparatus currently disclosed by the said patent document 1

  Hereinafter, embodiments of a gate valve according to the present invention will be described with reference to the drawings, taking as an example a case where a branch pipe is connected to an existing water pipe (an example of a fluid pipe). The branch pipe connection device shown in FIG. 1 is attached to a branch case 1 that is installed surrounding a water pipe K that is an existing pipe and is divided into a plurality of parts in the circumferential direction of the water pipe K, and a split surface 10 of the branch case 1. And a gate valve 2 connected with the end portion interposed therebetween.

  The gate valve 2 includes a valve box 21 constituting a part of a pipe line, a valve body 22 that is displaced between a closed position that blocks a flow path in the valve box 21 and an open position that opens the flow path, It has a valve shaft 23 that can operate the displacement of the valve body 22 and a valve lid 25 that rotatably supports the valve shaft 23. The valve box 21 is formed of a tubular body that can communicate between both ends, and constitutes a part of a pipe line that is branched from the water pipe K. In this gate valve 2, a flange is formed at the branch pipe side end on the right side of FIG. 1, but the shape of the end is not particularly limited. For example, the inlet end of the branch pipe can be connected to a receiving port. It doesn't matter.

  An insertion port 24 is formed through the valve box 21 so that the valve body 22 can enter and exit the valve box 21 through the insertion port 24. FIG. 1 shows a state in which the valve body 22 is raised and is in the open position. When the valve body 22 is lowered, the valve body 22 moves to the closed position shown in FIG. . The valve lid 25 protrudes outward from the valve box 21 in the pipe diameter direction, and accommodates the valve shaft 23 and the valve body 22 in the open position while covering the insertion port 24. A jig (not shown) is attached to the top 23a of the valve shaft 23 protruding from the top surface of the valve lid 25 as necessary.

  As shown in enlarged views in FIGS. 3 to 5, an opening 25 b through which the valve shaft 23 passes is provided on the top surface of the valve lid 25. The valve lid 25 includes a bush 16 that is fitted into the opening 25b and supports the valve shaft 23 from the top surface side, and an upper lid 17 that covers the bush 16 and shields the opening 25b. The bush 16 is a cylindrical member as shown in FIG. 6, and receives the flange 23b provided on the valve shaft 23 from above in a state where the valve shaft 23 is inserted into the insertion hole 16a, and from the opening 25b. The valve shaft 23 is supported so as not to come out.

  The bush 16 is locked to the opening 25b by a bayonet mechanism. In the present embodiment, the bayonet mechanism has a pair of overhanging portions 16b formed on the outer peripheral surface of the bush 16 on a pair of overhanging portions 25c (first overhanging portions) formed on the inner peripheral surface of the opening 25b. It is comprised so that (2nd overhang | projection part) may be latched. The overhang portion 25c is provided in an inner collar shape on the inner peripheral surface of the opening 25b, and a pair of notch portions 25d that allow the overhang of the overhang portion 16b of the bush 16 is provided between the pair of overhang portions 25c. Is formed.

  That is, in this bayonet mechanism, the protruding portion 16b of the bush 16 fitted into the opening 25b is inserted into the cutout portion 25d, and then the bush 16 is displaced around the axis so that the protruding portion 16b is moved to the protruding portion. By facing 25c, the bush 16 is locked to the opening 25b. Further, when the bush 16 in the locked state is displaced around the axis so that the overhanging portion 16b and the overhanging portion 25c do not face each other, the bush 16 is detached from the opening 25b.

  A pair of caulking projections 16c are provided on the upper surface of the bush 16 as shown in FIG. 6, and a pair of through holes 17a are formed in the upper lid 17 as shown in FIG. The caulking projection 16 c is inserted into the through hole 17 a of the upper lid 17 that covers the bush 16, and the upper lid 17 is fixed to the bush 16 by caulking the caulking projection 16 c. FIG. 8 shows a state before the upper lid 17 is fixed, and the state shown in FIG. 3 is obtained by caulking the protrusion of the caulking protrusion 16c with a hammer or the like. The bush 16 is made of, for example, a gun metal, but is not limited thereto.

  Thus, in the gate valve 2, after the bush 16 is locked to the opening 25 b by the bayonet mechanism, the upper lid 17 is fixed to the valve lid 25 by caulking the caulking protrusion 16 c of the bush 16 covered with the upper lid 17. The Therefore, it is not necessary to rotate and tighten the member, and the bush 16 and the upper lid 17 do not need to be threaded. Nevertheless, when the upper lid 17 is disassembled for some reason, it is only necessary to grind the caulked portion of the caulking protrusion 16c with a grinder or the like, which can be performed easily.

  In the present embodiment, the upper lid 17 is provided with a pair of anti-rotation protrusions 17b, which are inserted into the notch 25d as shown in FIG. 4 to prevent the bush 16 from rotating. This prevents the bushing 16 from rotating together with the rotation of the valve shaft 23 and prevents the locking of the bushing 16 by the bayonet mechanism without being noticed, and the safety when the upper lid 17 is disassembled. Can be secured. The rotation preventing projection 17b has a curved shape corresponding to the notch 25d, and is inserted into the notch 25d when the bush 16 is covered with the upper lid 17.

  In the present embodiment, the cylindrical collar 18 is fitted into the opening 25b, and the flange 23b is sandwiched between the bush 16 and the collar 18 so as to rotatably support the valve shaft 23. With this configuration, the valve shaft 23 can be supported so as to rotate stably and smoothly. The collar 18 is preferably formed of a material having a small frictional resistance with the valve shaft 23, and is made of a resin such as Duracon (registered trademark), but is not limited thereto.

  In the present embodiment, the valve box 21 and the valve lid 25 are separate, and an example in which the valve box 21 and the valve lid 25 are joined using a pair of lock pins 4 as shown in FIG. FIG. 10 is a front view of the valve lid 25, and FIG. 11 is a vertical cross-sectional view of the gate valve 2 showing a joint portion between the valve box 21 and the valve lid 25. The cross section of FIGS. 1 and 2 corresponds to the arrow AA in FIG. 10, and the cross section of FIG. 11 corresponds to the arrow BB in FIG. A box-shaped portion 21 a having an upper opening is provided on the outer peripheral surface of the valve box 21, and a lower end portion of the valve lid 25 is inserted therein.

  The lock pin 4 is U-shaped with a pair of insertion shafts 4a, and is inserted into a hole formed at a joint portion between the valve box 21 and the valve lid 25 (on the opposite side not depicted in FIG. 9). The same). This hole is configured by a concave groove 21b formed in the inner wall of the box-shaped portion 21a and a concave groove 25a formed in the lower end portion of the valve lid 25 facing each other. In the state where the lock pin 4 is inserted, the valve lid 25 is engaged with the valve box 21 via the insertion shaft 4a, and the valve box 21 and the valve lid 25 are firmly joined.

  The sealing material 21c is fitted in a recess formed in the inner wall of the box-shaped portion 21a, and is compressed between the valve box 21 and the valve lid 25 to seal the gap therebetween. According to such a configuration, when the valve lid 25 is joined to the valve box 21, it is only necessary to insert the lower end portion of the valve lid 25 into the box-like portion 21a to which the sealing material 21c is attached, and then insert the lock pin 4. Compared with a structure in which bolts and nuts are fastened (see FIG. 21), the workability at the time of attaching and detaching the valve lid 25 can be remarkably improved.

  In the modification shown in FIG. 12, the sealing material 20 is fitted in a recess formed in the lower end portion of the valve lid 25. In the structure of FIG. 11, when the valve lid 25 is joined to the valve box 21, there is a concern that the sealing material 21 c is pushed by the valve lid 25 and comes out of the recess. Since the lower end portion of the valve lid 25 to which the sealing material 20 is attached is inserted into the box-shaped portion 21a, occurrence of such a problem can be avoided.

  The sealing material 20 attached to the lower end portion of the valve lid 25 has a shape illustrated in FIG. 13 in a state before being compressed. The front end portions 20a of these sealing materials 20 are formed to bulge with a substantially circular cross section. When the valve lid 25 is joined to the valve box 21, the distal end 20a of the sealing material 20 is pressed against the inclined surface 21d provided on the inner wall of the box-shaped part 21a and is sufficiently compressed, so that the sealed state is accurate. It is configured to be obtained.

  The valve body 22 is formed by a plate-like body facing the valve shaft 23 from one side in the tube axis direction (left and right direction in FIG. 1) at the open position, and the details are as shown in FIG. With this structure, the thickness of the valve body 22 can be greatly reduced as compared with the valve body provided in the conventional soft seal gate valve, and the inter-surface dimension L of the gate valve 2 is shortened. When the flange is formed at the branch pipe side end as in this example, the inter-surface dimension L can be set to, for example, 230 mm or less regardless of the pipe diameter. In the present embodiment, the thickness T of the valve body 22 (the thickness of a body 22a described later) is smaller than the thickness (screw diameter) of the valve shaft 23, and the thickness t of the sealing material 3 is smaller than the thickness T of the valve body 22. .

  Moreover, the gate valve 2 has a thin-film-like sealing material 3 on the front surface on the branch pipe side, and a seal compressed between the valve body 22 and the valve box 21 in the closed position in the pipe axis direction. It is configured to be sealed with the material 3. Specifically, the peripheral edge portion of the valve body 22 in the closed position enters the peripheral groove 26 formed on the inner peripheral surface of the valve box 21, and the sealing material 3 is inserted into the groove wall surface 26 a of the peripheral groove 26 in the pipe axis direction. It is pressed and compressed. For this reason, it is not necessary to press the valve body 22 strongly against the inner peripheral surface of the valve box 21 to bring it into close contact in the radial direction, and the sealing function can be appropriately ensured while reducing the thickness of the valve body 22.

  In this gate valve 2, it is not necessary to closely contact the valve body 22 in the radial direction. Therefore, even if chips generated when the water pipe K is drilled are accumulated in the groove bottom of the circumferential groove 26, the sealing function is hindered thereby. It will not be done. In addition, in the valve box 21 of this embodiment, as shown in FIG. 2, the hollow 36 is formed in the existing pipe side rather than the circumferential groove 26 so that a chip may not adhere to the circumferential groove 26 or the valve body 22, and there exists it. Measures are taken to collect chips. Chips around the depression 36 can be discharged to the outside through the drain 37.

  As shown in FIG. 14, the valve body 22 includes a disk-shaped body 22a, a head 22b protruding upward from the body 22a, and a thin-film sealing material 3 bonded to the front surface of the body 22a. The body 22a is formed of a highly rigid material suitable for water stop, for example, a metal such as steel, and the sealing material 3 is formed of an elastic material such as rubber. In this embodiment, since the sealing material 3 is provided on the branch pipe side of the body 22a, when the water pressure from the water pipe K acts on the gate valve 2 in the closed position, the sealing material 3 is compressed in the pipe axis direction. To improve the sealing performance.

  The sealing material 3 of the present embodiment is formed in a circular shape, but substantially contributes to sealing between the valve body 22 and the valve box 21 and extends in an annular shape along the peripheral edge of the valve body 22. Part. The sealing material 3 has a lip portion 30 that protrudes in the tube axis direction and extends along the peripheral edge portion of the valve body 22 at the annular portion. The lip portion 30 includes an outer lip 31 and an inner lip 32 that is formed on the inner peripheral side of the outer lip 31 via a recessed groove 33 and has a raised height smaller than that of the outer lip 31. The lip portion 30 faces the groove wall surface 26a and develops a compressing action as will be described later.

  A valve shaft 23 is connected to the head 22b of the valve body 22, and the valve body 22 in the open position faces the valve shaft 23 from the existing pipe side on the left side in FIG. The valve shaft 23 is a male screw member extending along the displacement direction of the valve body 22, and a female screw top 27 screwed into the valve shaft 23 is fitted into the head 22b with play in the tube axis direction. ing. When the valve shaft 23 is rotated through a jig (not shown) such as a handle attached to the top 23a, the female screw top 27 moves up and down, and the valve body 22 moves up and down in conjunction therewith.

  As described above, in the gate valve 2, the peripheral portion of the valve body 22 enters the circumferential groove 26, so that a sealed state by the sealing material 3 is obtained. At this time, when the groove width of the circumferential groove 26 is set to be appropriately larger than the thickness T of the valve body 22, the peripheral portion of the valve body 22 smoothly enters the circumferential groove 26 and shuts off the gate valve 2. The torque is reduced. However, on the other hand, since the sealing material 3 is difficult to be compressed in the tube axis direction, the gate valve 2 is provided with a protrusion 5 on the inner peripheral surface of the valve box 21 as shown in FIG.

  FIG. 15 is a view of the gate valve 2 viewed from the right direction in FIG. 2, and shows a cross section in which the valve box 21 and the valve body 22 are cut at the center of the circumferential groove 26. A plurality of projections 5 are provided on the groove wall surface 26b of the circumferential groove 26 at intervals in the circumferential direction. These protrusions 5 are arranged so that the rear surface of the peripheral edge of the valve element 22 is in the tube axis direction (in this embodiment, on the branch pipe side) And) to push the seal material 3 to be compressed. According to such a configuration, the sealing state by the sealing material 3 can be expressed smoothly, and the sealing function can be improved satisfactorily.

  Further, the valve body 22 is somewhat lowered until the transition to the closed position is completed after the peripheral edge of the valve body 22 starts to enter the circumferential groove 26. During this time, the sealing material 3 is applied to the groove wall surface 26a. When pressed, the sealing material 3 may be dragged and damaged, or the torque may increase. Therefore, in this gate valve 2, not only the protrusion 5 is provided on the inner peripheral surface of the valve box 21, but also a notch 6 having an inclined surface is formed at a location facing the protrusion 5 of the valve body 22. The protrusion 5 enters the notch 6 as the valve body 22 moves to the closed position.

  When the valve body 22 moves to the closed position, in the process from the state shown in FIG. 15 (a) to the state shown in FIG. 15 (b), as shown in FIG. 16, the protrusion 5 entering the notch 6 rubs against the inclined surface. To touch. As described above, the protrusion 5 slides against the inclined surface of the notch 6 and gradually presses the valve body 22, so that the drag of the seal material 3 can be suppressed and the compression can be performed little by little. Increase can be prevented. In the present embodiment, in the state of FIG. 15B in which the transition to the closed position is completed, the protrusion 5 is positioned above the notch 6, and the protrusion 5 detached from the notch 6 stabilizes the valve body 22. Press.

  When the transition of the valve body 22 to the closed position is completed, the space between the valve body 22 and the valve box 21 is sealed by the sealing material 3. At this time, the lip portion 30 comes into contact with the groove wall surface 26a, and as shown in FIG. Is increased. Further, by supporting the outer lip 31 that has fallen and deformed by the inner lip 32, the sealing material 3 can be prevented from being cut or peeled off. Further, as shown in FIG. 17, when the lip portion 30 passes through the insertion port 24, the inner lip 32 can come into contact with the inner peripheral surface of the valve box 21 before the outer lip 31. Cutting of the material 3 can be prevented.

  On the other hand, when the inner lip 32 is not formed, the outer lip 31 that has fallen and deformed cannot be supported, so that the lip portion 30 is entirely pulled toward the inner peripheral side, and the sealing material 3 is peeled off from the body 22a. There is a concern. Moreover, when the lip | rip part 30 does not comprise the concave groove 33 but has raised in the shape of a mere mountain, there exists a possibility that the improvement of the compression effect | action mentioned above cannot be obtained and it may cut | disconnect from a root. The concave groove 33 is preferably a U-shaped groove as in the present embodiment, whereby the outer lip 31 tends to fall to the inner peripheral side.

  As shown in FIG. 14B, guide parts 7 projecting in the tube axis direction are formed on the back surface of the valve body 22 at three locations on the upper side and the left and right sides. The outer surface of the guide portion 7 is inclined along the displacement direction of the valve body 22, and an inclined surface 28 having an inclination that matches the outer surface of the guide portion 7 is formed at a contact portion of the valve box 21 with the guide portion 7. Is formed. Accordingly, when the valve body 22 is shifted to the closed position, the valve body 22 can be guided and properly positioned by contact between the guide portion 7 and the inclined surface 28.

  In the present embodiment, positioning protrusions 29 are formed on the outer peripheral surface of the gate valve 2, and these are used for connection with the branch case 1. The branch case 1 is composed of divided bodies 1A and 1B that can be water-tightly attached to the water pipe K, and has a split T-shaped pipe shape that is split into two vertically in FIG. On the split surface 10 of the branch case 1, the flanges of the split bodies 1 </ b> A and 1 </ b> B are fastened by a fastener 11 composed of a bolt and a nut. By tightening the fastener 11, the dividing surface 10 is watertightly closed via the packings 12 and 13, and the gate valve 2 is connected to the branch case 1.

  Since the split surface 10 of the branch case 1 is positioned in a substantially horizontal direction, even if a large load is generated due to ground fluctuation or secular change, the load is unlikely to act in the direction in which the bolt of the fastener 11 extends. It is possible to effectively prevent water leakage by suppressing the unexpected opening. The positioning protrusion 29 of the gate valve 2 is fitted into the recess of the extending portion 15 formed in the branch case 1, thereby positioning the gate valve 2 in the circumferential direction. As such a branch case, the structure disclosed in Japanese Patent Application Laid-Open No. 2009-127686 and Japanese Patent Application Laid-Open No. 2009-299826 by the present applicant can be applied in addition to the above-mentioned Patent Document 1.

  An example of a procedure for connecting a branch pipe to an existing water pipe K using this branch pipe connection device will be briefly described. First, as shown in FIG. 1, the branch case 1 is externally fitted to the water pipe K and attached, and the end portion of the gate valve 2 is sandwiched between the dividing surfaces 10 and watertightly connected. Next, as shown in FIG. 18, the punching device 8 is connected to the gate valve 2, and the peripheral wall of the water pipe K is punched by the cutter 80. When the drilling is completed, the cutter 80 is moved backward to move the valve body 22 to the closed position as shown in FIG.

  Since the face-to-face dimension is suppressed in this gate valve 2, when the peripheral wall of the water pipe K is punched, the moving stroke of the cutter 80 is short, and a small punching device can be used. If a flange is formed at the branch pipe side end as in this example, the pipe axial distance from the flange to the peripheral wall of the water pipe K is, for example, 240 mm or less, regardless of the pipe diameter of the gate valve 2. It is possible to set.

  In this embodiment, since the valve body 22 is disposed closer to the branch case with respect to the valve shaft 23 (that is, on the water pipe K side), the valve body 22 in the closed position with respect to the cutter 80 in the retracted position. Since the valve shaft 23 can be moved away from the branch case 1 in the tube axis direction, the inter-face dimension of the gate valve 2 can be skillfully shortened and the drilling stroke can be effectively performed. Can be shortened. If the piercing device 8 is removed from the gate valve 2 and a branch pipe (not shown) is connected instead, and the valve body 22 is displaced to the open position, the water is divided from the water pipe K and the branch pipe is used. It will be ready.

  In the above-described embodiment, an example in which a sealing material is provided on the front surface of the valve body on the branch pipe side and a notch or a guide portion is provided on the back surface of the valve body on the existing pipe side is shown. As in 19, they may be arranged in reverse. In the valve body 22 shown in FIG. 19, in order to prevent the central guide portion 7 from interfering with the valve shaft 23, a vertical groove 72 is provided in the central guide portion 7 as shown in FIG. For the purpose of preventing rust, rubber lining may be applied to both surfaces of the valve body.

  The present invention is not limited to the embodiment described above, and various improvements and modifications can be made without departing from the spirit of the present invention. Therefore, regarding the structure of the gate valve, for example, the valve box and the valve lid may be integrally manufactured, or the valve body may be directly screwed to the valve shaft without using a screw top. Alternatively, contrary to the above-described embodiment, a sealing material may be provided on the front surface of the valve body on the branch pipe side, and a notch or a guide portion may be provided on the back surface of the valve body. It may be arranged on the branch pipe side of the shaft.

  In the above-mentioned embodiment, although the example which uses the gate valve concerning the present invention for the branch pipe connection construction for connecting a branch pipe to an existing water pipe was shown, it is not limited to this. In the gate valve used for various fluid pipes, such as agricultural water and industrial water, it can apply without restriction.

2 Gate valve 3 Sealing material 4 Lock pin 16 Bushing 16b Overhang part (second overhang part)
16c Caulking projection 17 Upper lid 17a Through hole 17b Anti-rotation projection 18 Collar 21 Valve box 21a Box-shaped portion 21b Groove 21c Sealing material 21d Inclined surface 22 Valve body 23 Valve shaft 23b Hook 25 Valve lid 25a Groove 25b Opening 25c Tension Outing part (first overhanging part)
25d Notch K Water pipe (an example of a fluid pipe)

Claims (3)

A valve box that forms part of a pipe line, a valve body that is displaced between a closed position that blocks a flow path in the valve box and an open position that opens the flow path, and the displacement of the valve body is manipulated In a gate valve having a possible valve shaft and a valve lid that rotatably supports the valve shaft,
The valve lid includes a bush that is fitted into an opening provided on a top surface of the valve lid and supports the valve shaft from the top surface side, and an upper lid that covers the bush and shields the opening.
The bush is locked to the opening by a bayonet mechanism,
A gate valve characterized in that the upper lid is fixed to the bush by inserting a caulking projection provided in the bush into a through hole formed in the upper lid and caulking the caulking projection. The bayonet mechanism locks the first overhang formed on the inner circumferential surface of the opening and the second overhang formed on the outer circumferential surface of the bush;
A cutout portion that allows the second overhanging portion to enter is formed on the inner peripheral surface of the opening, and the rotation of the bush is rotated by inserting a rotation prevention protrusion provided on the upper lid into the cutout portion. The gate valve according to claim 1, which is configured to be preventable. The cylindrical collar is inserted in the opening, and a flange provided on the valve shaft is sandwiched between the bush and the collar to support the valve shaft rotatably. Gate valve.

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