Fixing device for valve element, and valve using the same

Abstract

To provide a fixing device for a valve element and a valve using the same, capable of reliably maintaining the state of stopping the turn of and fixing the valve element, while remarkably improving the workability without the need for a fixture or the like at the time of replacing a speed reducer for example, not only sufficiently securing the strength of a stem.SOLUTION: A valve element 2 is rotatably provided in a valve box 1 via a stem 3, a speed reducer 9 is detachably mounted on an axially mounting part 11 in which the stem 3 is axially mounted, via a spacer 4, a stopper part 20 is provided on the outer periphery of the stem 3 located in the spacer 4, and a fixing member 6 is arranged on the lateral face of the spacer 4. By pushing or locking the fixing member 6 against or to the stopper part 20, the turn of the stem 3 is stopped to fix the valve element 2 to a predetermined position.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a valve body fixing device, and more particularly to a valve body fixing device suitable for use in underground piping, and a valve using the same. [Background technology]

[0002] 2. Description of the Related Art Conventionally, butterfly valves are generally known as valves used when controlling the opening and closing or intermediate opening of a flow passage of a pipe laid underground. When a butterfly valve is buried underground, a connection stand is usually provided on the top of the valve box, and an operating device (reduction gear) is attached to the top of the valve box via this stand. The operating device is provided so that it can be operated from above ground using a handle or the like, and the handle is used to operate the operating device, and the valve body can be opened and closed from the operating device via a stem. This type of butterfly valve is buried for a long period of time after installation, so it is more susceptible to deterioration than butterfly valves installed in normal pipelines, and in particular, when the operating device deteriorates, it becomes difficult to open and close it, so the operating device requires regular replacement and maintenance. In this case, in the case of a butterfly valve in a water main pipe laid underground, the operating device is usually not detachable when the water supply is interrupted, and the replacement work of the operating device is performed when the water supply is interrupted.

[0003] In response to this, for example, Patent Document 1 discloses a butterfly valve in which an operating device is provided so as to be detachable even when the water supply is not interrupted. In this butterfly valve, a stand is provided between the valve body and the operating device (reduction gear), and a plug is detachably attached to each of a number of fixing holes provided in this stand. Furthermore, a fixing rod is provided so as to be detachably inserted into the fixing holes and a through hole formed in the valve rod on the upper side. When removing the operating unit, the plug is removed from the stand to open the fixing hole, and the valve body is rotated to the fully open position to open the through hole so that it is aligned in a straight line with the fixing hole. The valve body is then fixed in the fully open position by inserting a fixing rod through the fixing hole and the through hole, and the operating unit can be removed in this state without interrupting the water supply.

[0004] On the other hand, the butterfly valve in Patent Document 2 is provided with an opening fixing jig that brakes the valve stem, two rod-shaped guides that restrict the movement of the braking member, and an opening division fixing jig that is a separate part from the stand and brakes the valve stem when the reducer is separated, allowing the reducer to be detachably attached to the valve body (see Figures 1 to 6). When removing the actuator, the opening degree fixing jig is connected to the tip of the valve stem and the guide is fixed to the top of the valve, and the reducer is moved upward along the guide with the connection between the reducer and the stand released. Next, the opening degree division fixing jig is inserted between the reducer separated from the connection base and the connection base, and the valve stem is fixed to maintain the water supply uninterrupted (valve open), and in this state the actuator can be removed and replaced. Furthermore, the same document 2 also discloses a butterfly valve in which an aperture fixing jig consisting of two jigs is used to fix and brake the valve stem from the side, without using an aperture fixing jig that fixes the tip side of the valve stem, and the reducer can be removed (see Figures 7 to 9). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6456097 [Patent Document 2] JP 2019-210962 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the former Patent Document 1, a through hole is formed in the valve stem to fix the valve body in the closed state, which reduces the strength of the valve stem. Moreover, in order to strongly hold the valve stem in the open state, the fixing stem needs to be made thicker, in which case the through hole also becomes larger in diameter, making the valve stem even thinner, making it even more difficult to ensure strength. In addition, a process is required to form a through hole in the valve stem, and the process requires high precision to accurately drill the through hole.

[0007] Furthermore, in order to fix the valve rod in a state where water supply is not suspended (valve open state) with the fixing rod, the length of the fixing rod must be at least as long as the sum of the length of the fixing hole formed in the horizontal direction of the stand and the length of the through hole, or longer. By making the fixing rod longer in this way, the load on the fixing rod when suppressing the rotation of the valve rod also becomes larger, and when fixing the valve rod in a state where water supply is not suspended, extra work space is required to insert and remove the long fixing rod into and from the fixing hole and the through hole, and to use a jig for insertion and removal. As a result, a valve case with a large internal space for installing the valve is also required. In order to insert the fixing rod into the through hole and the fixing hole, they need to be communicated in a centered state, and the alignment is also difficult.

[0008] In the case of the latter butterfly valve in FIGS. 1 to 6 of Patent Document 2, extra space is required to attach a rod-shaped guide and an opening fixing jig for connection to the tip of the valve stem, and these guides and opening fixing jigs increase the number of parts for fixing the valve stem, which causes the problem of increasing the labor required to replace the reducer. In the butterfly valve of Figures 7 to 9 of the same document 2, the fitting portion for fixing two aperture fixing jigs from the sides of the valve stem is formed with a reduced diameter, which reduces the strength of the valve stem. Furthermore, the fitting portion has opposing flat surfaces that are parallel to each other and is shaped to fit into a recess formed in the aperture fixing jig, which makes it difficult to process the fitting portion onto the valve stem and requires high dimensional accuracy.

[0009] When fixing the valve stem, in Patent Document 1, a fixing member is required; in Figures 1 to 6 of Patent Document 2, two rod-shaped guides, an opening fixing jig, and an opening division fixing jig are required; and in Figures 7 to 9 of Patent Document 2, an opening fixing jig consisting of two jigs is required in addition to the components of the stand. Therefore, these parts and jigs must be transported to the construction site and must be managed when not in use.

[0010] The present invention was developed to solve the above-mentioned problems, and its object is to provide a valve body fixing device and a valve using the same, which can reliably stop the rotation of the valve body and maintain a fixed state, not only ensure sufficient strength of the stem, but also eliminate the need for fixing tools when replacing the reducer, thereby significantly improving workability. [Means for solving the problem]

[0011] In order to achieve the above object, the invention of claim 1 is a valve body fixing device in which a valve body is provided within a valve box and is freely rotatable via a stem, a reducer is detachably mounted on the shaft mounting portion on which the stem is shaft mounted via a spacer, a stopper portion is provided on the outer periphery of the stem located within the spacer, and a fixing member is arranged on the side of the spacer, and the fixing member is pressed against or engaged with the stopper portion to stop the rotation of the stem and fix the valve body in a predetermined position.

[0012] The invention according to claim 2 is a fixing device for a valve body, wherein the stopper portion is a flat portion or a stopper groove formed on the outer peripheral surface of a stopper ring which is integrally provided on the outer periphery of a stem located within the spacer.

[0013] The invention according to claim 3 provides a fixing device for the valve body, in which the fixing members are arranged at least in two or more places at a predetermined interval on the side of the spacer.

[0014] The invention according to claim 4 is a fixing device for the valve disc, in which the fixing member is disposed within the spacer even when the valve disc is not fixed.

[0015] The invention according to claim 5 provides a fixing device for a valve body, in which the fixing member is a fixing bolt, and the fixing bolt is screwed into the side surface of the spacer so that the tip of the fixing bolt is pressed against or engaged with the stopper portion.

[0016] The invention of claim 6 is a valve body fixing device in which the fixing bolt is screwed through a collar so that the valve body will not be fixed even if the fixing bolt is tightened if it is not to be fixed, and the unfixed state can be visually confirmed by the position of the bolt head.

[0017] The invention of claim 7 is a valve body fixing device in which an O-ring case is provided in the shaft mounting portion, multiple O-rings are attached to the inner diameter portion of this O-ring case, and an O-ring made of fluororubber is attached to the upper opening side of the O-ring case.

[0018] The invention according to claim 8 is a valve using the valve body fixing device. Effect of the Invention

[0019] According to the invention of claim 1, the valve body is fixed in a predetermined position by stopping the rotation of the stem with the stopper portion and the fixing member provided on the outer periphery of the stem located in the spacer, so that the valve body can be fixed in a predetermined rotational state and maintained in this fixed state without special processing for fixing the fixing member to the stem, while ensuring the solid state and large diameter state of the stem and ensuring sufficient strength. By providing the fixing member in a configuration in which it is stored in the spacer, it is possible to perform the stem fixing work while significantly improving the workability without requiring external parts such as fixing tools when replacing the reducer. By preventing the fixing member from being exposed from the spacer, the overall size can be prevented from increasing, and it is possible to replace and maintain the reducer even in a narrow work space, and it is also possible to replace and maintain the internal parts.

[0020] According to the invention of claim 2, the stopper portion is a flat portion or a stopper groove formed on the outer peripheral surface of a stopper ring that is integrally provided on the outer periphery of the stem located in the spacer, so that this stopper portion can be easily formed on the stopper ring, and when the fixing member is pressed against or engaged, a force is applied to the stopper ring toward the outer diameter side, so that a strong force is applied in the rotation direction of the stem to firmly maintain the stopped state of the valve body. The stem can also be fixed at any intermediate opening degree by attaching the stopper ring in a rotated state relative to the stem, or by changing the position where the flat portion or the stopper groove is formed.

[0021] According to the invention of claim 3, the stopper portion is fixed at at least two points at a predetermined interval by the fixing members, so that the torque applied from the stem to each fixing member is halved, and the load on each fixing member is reduced, while the stem is firmly fixed by these two fixing members. In particular, if the fixing members are arranged at intervals of approximately 90°, the resultant force when fixing them can be transmitted to the stem, and the force for fixing the stem can be further improved. Furthermore, even if one of the fixing members becomes loose, the fixed state of the stopper portion can be maintained by the remaining one.

[0022] According to the invention of claim 4, the fixing member is arranged within the spacer even when the valve body is not fixed, so that when replacing the reducer, for example, no external parts such as fixing devices are required and the stem can be fixed while significantly improving workability.

[0023] According to the invention of claim 5, a general-purpose bolt can be used as the fixing member, and the fixing bolt can be screwed into the side of the spacer using a general-purpose tool, and the tip of the bolt can be pressed against or locked to the stopper part. This allows the fixing force to be increased by utilizing the tightening torque when the bolt is fastened, and the frictional force of the bolt tip prevents the fixing bolt from loosening, maintaining the fastening force and reliably holding the stem in a state where it is prevented from rotating. Furthermore, by increasing the outer diameter of the stopper ring, the length of the fixing bolt pressed against or locked to the outer circumferential surface is shortened to suppress deformation of the fixing bolt when the stem is fixed, and the distance from the stem center to the stopper part is lengthened through the outer diameter of the stopper ring, so that the moment that suppresses the rotation torque of the stem is increased, and the stem is reliably prevented from rotating even when a large rotation torque is applied to the stem by a fluid or the like. The fixing bolt can be screwed into the spacer and integrated regardless of whether the stem is fixed or not, so that the fixing bolt can be prevented from being lost, and the fixing bolt is prevented from being exposed to the outside from the spacer, thereby preventing the entire spacer from becoming large.

[0024] According to the invention of claim 6, the stem can be fixed in the valve open state or made rotatable by tightening the fixing bolt through a collar inserted into the opening of the spacer. Normally, the collar is inserted into the opening in a direction such that the locking flange is located on the opening side, and the fixing bolt is screwed into the opening from above. When the fixing bolt is tightened and the bolt head is engaged with the locking flange, the tightening of the fixing bolt is restricted. At this time, the stem is in an unfixed state because the tip surface of the fixing bolt is prevented from contacting the stopper ring, and the stem can be freely rotated by the reducer to adjust the valve to an open / closed state or an intermediate opening degree. On the other hand, when the stem is fixed, the collar is inserted into the opening in a direction such that the locking flange is located on the inner side, and the fixing bolt is screwed into the opening from above. In this case, when the fixing bolt is tightened, the tip of the fixing bolt presses the stopper ring, and the tightening torque prevents the stem from rotating and fixes the valve in the open state. At this time, when the bolt head abuts against the locking flange, excessive tightening of the fixing bolt is restricted, preventing excessive force from being applied to the stem from the fixing bolt. Because the degree of insertion of the bolt head into the spacer differs when the stem is fixed and when it is not fixed, the position of the bolt head can be visually confirmed from the outside to determine whether the stem is fixed or not fixed.

[0025] According to the invention of claim 7, the seal part is unitized by the O-ring case, and the shaft seal performance is improved by the multiple O-rings, so that leakage to the outside is reliably prevented even if the stem is fixed in the valve open state for a long period of time or if the stem is repeatedly rotated when not fixed. Moreover, the O-ring made of fluororubber provided on the upper opening side of the O-ring case is durable, and a long life can be achieved without adding another O-ring.

[0026] According to the invention of claim 8, the strength of the stem is sufficiently ensured without special processing for fixing the fixing member to the stem, and the valve body can be fixed in a specified rotational state and maintained in this fixed state. When replacing the reducer, no external parts such as fixing tools are required, and the stem can be fixed while significantly improving workability. The overall size can be prevented from increasing, and the reducer can be replaced and maintained even in a small work space, and internal parts can be replaced and maintained. If the stopper ring is configured to be fixed with a fixing member, damage to the stem can be prevented. As a result, for example, if the valve is a butterfly valve and this butterfly valve is connected to a pipe, the valve body can be firmly fixed in place at full or intermediate opening without interruption to water supply while still providing the above-mentioned functions. [Brief description of the drawings]

[0027] [Figure 1] 1 is a partially cutaway front view showing a first embodiment in which a valve body fixing device of the present invention is used in a butterfly valve. FIG. [Diagram 2] FIG. 2(a) is an enlarged, partially cutaway, side view showing the vicinity of the mounting portion of the butterfly valve of FIG. 1, and FIG. 2(b) is a cross-sectional view taken along the line AA of FIG. [Diagram 3] 3 is a partially enlarged cross-sectional view showing the vicinity of a spacer in FIG. 2, with a portion omitted. [Figure 4] 4 is a partially enlarged cross-sectional view showing the collar of FIG. 3 in a changed orientation; FIG. [Diagram 5] FIG. 4 is a half cross-sectional view showing an O-ring case. [Figure 6] FIG. 3 is a bottom view of the reducer in FIG. [Figure 7] 1A is a partially cutaway enlarged side view showing a second embodiment in which a fixing device for a valve body of the present invention is used in a butterfly valve, and FIG. [Figure 8] 10(a) is a partially cutaway enlarged side view showing a third embodiment in which a fixing device for a valve disc of the present invention is used in a butterfly valve, and FIG. [Figure 9]13 is a cross-sectional view of a main portion showing a fourth embodiment in which a fixing device for a valve body of the present invention is used in a butterfly valve. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, an embodiment of the valve disc fixing device of the present invention and a valve using the same will be described in detail with reference to the drawings. In this embodiment, an example in which the valve disc fixing device is applied to a butterfly valve will be described. Fig. 1 shows a first embodiment in which the valve disc fixing device of the present invention is applied to a butterfly valve in a closed state, and Fig. 2 shows an enlarged view of the vicinity of the mounting portion when the butterfly valve of Fig. 1 is in an open state.

[0029] In the figure, the butterfly valve comprises a valve body 1, a valve disc 2, a stem 3, a spacer 4, a stopper ring 5, a fixing member 6, a collar 7, and an O-ring case 8, and is provided on the upper part of which a reducer 9 can be mounted. In this embodiment, for example, the valve body 1 and the valve disc 2 are each formed from a metal material such as cast iron, the stem 3, the spacer 4, the stopper ring 5, the fixing member 6, and the collar 7 are each formed from a metal material such as SUS, and the O-ring case 8 is formed from a metal material such as copper casting. The butterfly valve is buried in the ground, for example, and a flow passage 1a formed on both sides of a valve box 1 is connected to a pipe (not shown).

[0030] The valve box 1 is shaped so that a long stem 3 and a disk-shaped valve element 2 can be attached thereto, and the valve element 2 is provided in the flow path of the valve box 1, and the stem 3 is attached to the valve element 2 integrally with a mounting bolt 10. A shaft mounting portion 11 is provided on the upper side of the valve box 1, and a flange portion 12 is formed on the upper end side of the shaft mounting portion 11.

[0031] The stem 3 has a reduced diameter portion 3a formed on its upper side, and a key groove 13 formed in this reduced diameter portion 3a. In this example, the key groove 13 is formed at a position perpendicular to the flow path 1a when the stem 3 is in the valve closed state or the valve open state shown in Fig. 1. A stopper ring 5 is provided on the stem 3 so that it can be attached thereto by a key 14 through the key groove 13, and the attachment structure of the stem 3 and the stopper ring 5 allows the stopper ring 5 to rotate integrally with the stem 3 when the stem 3 is rotated.

[0032] The stem 3 has an enlarged diameter portion 3c formed on the lower side from the reduced diameter portion 3a via a step portion 3b. The stem 3 is attached inside the valve box 1 with the enlarged diameter portion 3c side journaled on the journal portion 11, and is provided so as to be freely rotatable by a reducer 9 mounted on the reduced diameter portion 3a side. In this case, the valve element 2 is opened or closed when the stem 3 is operated at a rotation angle of approximately 90°.

[0033] A spacer 4 is fixed to the flange portion 12 of the valve box 1 by means of mounting bolts 15, and a reducer 9 is detachably mounted on the shaft mounting portion 11 with the spacer 4 interposed therebetween. The spacer 4 is formed in a substantially cylindrical shape, and a stem insertion hole 16 is formed in the center of the spacer 4. An enlarged diameter storage section 17 for storing the stopper ring 5 is formed in the upper side of the stem insertion hole 16, and an enlarged diameter hole section 18 for mounting the O-ring case 8 is formed in the lower side, both of which are concave.

[0034] A stopper ring 5 is attached to the outer periphery of the stem 3 located within the spacer 4 at a position corresponding to the storage portion 17. The inner periphery of the stopper ring 5 is provided with an inner diameter large enough to allow the reduced diameter portion 3a of the stem 3 to be fitted therein, and a key groove 19 into which the key 14 can be attached is formed in part. The stopper ring 5 is fixed integrally to the stem 3 in a positioned state by the key 14 through the key groove 19 and the key groove 13 formed in the stem.

[0035] The outer peripheral surface of the stopper ring 5 is provided with stopper portions 20 consisting of flat portions, and in this embodiment, four flat portions (stopper portions) 20 are formed to form an angle of approximately 90° with the adjacent flat portions 20, so that the outer peripheral surface of the stopper ring 5 is provided with an approximately square cross section, as shown in FIG. 2(b). A tip 6a of a fixing member 6, which will be described later, is provided so as to be able to be pressed against each of the four flat portions 20, and when the fixing member 6 is pressed against the tip 6a, the rotation of the stopper ring 5 is restricted, and the stem 3 is also fixed through the key 14. In this example, the key groove 19 of the stopper ring 5 is formed at a position that allows it to be fixed to the stem 3 so that the fixing member 6 can be pressed against the flat portions 20 when the stem 3 to which the stopper ring 5 is attached is in the valve closed state.

[0036] Two mounting holes 21 are formed at a side of the spacer 4 at an interval of approximately 90° so as to penetrate to the stem insertion hole 16, and in this example, each mounting hole 21 is provided with a female thread 22 and a hole-shaped opening 23. The opening 23 is formed with a predetermined depth and with a larger diameter than the female thread 22 on the mounting side of the fixed member 6, and the female thread 22 is formed to penetrate to the stem insertion hole 16, continuing from this opening 23.

[0037] The fixing members 6 are fixing bolts, and in this example are hexagon socket head bolts with male threads 24 that screw into the female threads 22. The fixing bolts 6 are screwed into the female threads 22 from the opening 23 side of the spacer 4, and are disposed at least in two or more places at a predetermined interval on the side of the spacer 4, with the fixing bolts 6 being integrally provided within the spacer 4 by this screwing.

[0038] In this embodiment, the fixing bolts 6 are arranged at two locations on the spacer 4 at an interval of approximately 90°, and when these two fixing bolts 6 are screwed in, each tip 6a is arranged to be able to be pressed against the adjacent stopper portions 20, 20 of the stopper ring 5, and by tightening each fixing bolt 6 to press the stopper portion 20, the stopper portion 20 and the fixing member 6 stop the rotation of the stem 3 and fix the valve body 2 in a predetermined position. In this example, the stem 3 (valve body 2) is rotated approximately 90° from the position shown in Figure 1 to open the valve (fully open) and is fixed in this position, making it possible to maintain the flow path 1a in an uninterrupted water supply state.

[0039] The collar 7 is formed in a cylindrical shape with a predetermined outer diameter and length that allows it to be inserted into the opening 23, and an annular locking flange 30 is formed on the inner peripheral end of the collar 7. The locking flange 30 is formed so that its inner diameter is slightly larger than the male thread 24 of the fixing bolt 6 and protrudes further inward than the head 31 of the fixing bolt 6, and is provided to allow the male thread 24 to be inserted and lock the head 31. The collar 7 is provided so that it can be inserted into the opening 23 with its insertion direction relative to its axial direction changed, that is, with the locking flange 30 positioned on the front side or the back side with respect to the opening 23, and by inserting the fixing bolt 6 into the mounting hole 21 through the collar 7, it is possible to change the position of the fixing bolt 6 in the longitudinal direction and change the tightening length.

[0040] 3 shows the collar 7 inserted with the locking flange 30 positioned at the rear side of the opening 23. In this case, the length that the fixing bolt 6 can be tightened is increased, and when the fixing bolt 6 is tightened, the tip 6a can be screwed in until it presses against the flat surface 20 of the stopper ring 5, and the tip 6a can press the flat surface 20 to fix the stem 3 (valve body 2).

[0041] On the other hand, Fig. 4 shows a state in which the collar 7 is inserted with the locking flange 30 positioned on the front side with respect to the opening 23. In this case, when the fixing bolt 6 is tightened, its head 31 is locked to the locking flange 30, and its tip 6a is not screwed in to a position where it presses against the flat surface 20 of the stopper ring 5. In this way, the length by which the fixing bolt 6 can be tightened is shorter than in the case of Fig. 3, so that the stem 3 (valve element 2) is not fixed, and the stem 3 (valve element 2) can be rotated to open / close or intermediate opening degree through the reducer 9 by a handle or the like (not shown). The above-mentioned fixing bolt 6 and collar 7 are incorporated in the spacer 4 in the state shown in either FIG. 3 or FIG. 4 as components constituting the butterfly valve, even when the butterfly valve is not in use.

[0042] 5 shows an O-ring case 8, which is formed in a cylindrical shape and has an annular flange 32 at the top and a cylindrical portion 33 below the annular flange 32, the cylindrical portion 33 having a smaller diameter than the annular flange 32. A plurality of mounting grooves 34 are formed in the outer and inner diameter portions of the O-ring case 8, and an O-ring 35 made of a rubber material such as NBR (acrylonitrile butadiene rubber) is mounted in each mounting groove 34. Furthermore, an O-ring 36 made of a durable material such as fluororubber is mounted in the mounting groove 34 on the upper end opening side above the two O-rings 35 at the center and bottom of the O-ring case 8.

[0043] As shown in Figures 1 and 2, the O-ring case 8 with O-rings 35, 36 attached is attached between the valve box 1 and the spacer 4 with its cylindrical portion 33 inserted into the mounting portion 11 and its annular flange portion 32 housed in the enlarged diameter hole portion 18, and the inner and outer periphery of this O-ring case 8 are sealed by the O-rings 35, 36, respectively, thereby preventing leakage from the valve box 1 side.

[0044] The reducer 9 shown in FIG. 6 is provided to reduce the speed of rotation from the handle and transmit it to the stem 3, and is provided with a reduction mechanism (not shown) inside. An output shaft 40 of the reduction mechanism is provided at the lower center, which is the output side of the reducer 9, and an insertion hole 41 is formed in the output shaft 40 with an inner diameter large enough to insert the reduced diameter portion 3a at the upper part of the stem 3. Two key grooves 42 are formed in the insertion hole 41 at approximately 90° intervals and have approximately the same cross-sectional shape as the key groove 19 of the stopper ring 5, and the key 14 engaged with the stem 3 or a key (not shown) provided separately from the key 14 is provided so that it can be engaged with each key groove 42. Four communication holes 43 are formed at equal intervals on the outer periphery of the bottom surface of the reducer 9, and the reducer 9 is provided so that it can be mounted integrally with the upper part of the spacer 4 through the communication holes 43 with bolts and nuts 44, as shown in FIG. 1.

[0045] When the reducer 9 is mounted on the spacer 4, the output shaft 40 of the reducer 9 is rotated to the valve open or closed position, and the output shaft 40 is connected to the stem 3 by the key 14 or another key attached to the keyway 13 of the stem 3 while engaging the key 14 or another key with one of the two keyway portions 42, and in this state, the reducer 9 is connected to the upper part of the spacer 4 by a bolt nut 44 through the communication hole 43 as shown in FIG. 1. This makes it possible to attach the reducer 9 to the butterfly valve in the valve closed or valve open state, while fixing the output shaft 40 in a position on the stem 3 through the keyway portion 42 while aligning the opening and closing operation direction. As described above, the output shaft 40 of the reducer 9 can be connected to the stem 3 by the key 14 attached to the stem 3 or a key provided separately from the key 14, and in either case, it is firmly connected to the stem 3.

[0046] In this case, by providing the two key groove portions 42 in the reducer 9, the butterfly valve can be set in either an open or closed state, and by mounting the reducer 9 in a predetermined orientation so that the position of the key groove portions 42 is aligned with the key groove 13 of the stem 3, the opening and closing direction of the valve body 2 can be changed with respect to the rotation direction of the reducer 9. This makes it possible to accommodate either the case where a butterfly valve is attached to the reducer 9 so that it opens when rotated to the left (a butterfly valve that opens in a left direction) or the case where a butterfly valve is attached to the reducer 9 so that it opens when rotated to the right (a butterfly valve that opens in a right direction), by changing the orientation of the reducer 9 and connecting it. In this embodiment, the butterfly valve is set to open when the operating device 9 (valve body 2) is rotated to the left.

[0047] In the above embodiment, an example was described in which the valve body fixing device of the present invention was applied to a butterfly valve, but the application of the valve body fixing device of the present invention is not limited to butterfly valves and can be applied to various types of valves.

[0048] Although a fixing bolt is used as the fixing member 6, the fixing member 6 is not limited to the fixing bolt 6 and any fixing member 6 provided in any manner can be used as long as it can stop the rotation of the stem 3 through the stopper ring 5 provided on the stem 3. Therefore, the mounting hole 21 of the spacer 4 does not necessarily need to have a male thread 24 formed therein.

[0049] In addition, the stopper ring 5 is provided separately from the stem 3 and attached to the stem 3, but the stopper ring 5 may be formed directly on the stem 3 and the stem 3 and the stopper ring 5 may be provided integrally.

[0050] The stopper portion 20 that presses the fixing bolt 6 against the outer peripheral surface of the stopper ring 5 is formed as a flat portion, but this stopper portion 20 can be formed in various shapes as long as it is capable of exerting frictional force between itself and a groove portion (not shown), a curved portion, or the tip of a fixing member to stop and maintain the rotation of the stem.

[0051] The fixing bolts (fixing members) 6 may be provided at two or more locations on the side of the spacer 4 at intervals other than approximately 90°, and can also be arranged at any interval (angle) as long as they are provided at at least two or more locations on the side of the spacer at a predetermined interval. Therefore, it is also possible to provide the fixing members 6 at three or more locations at equal intervals, or to arrange them at three or more locations at any interval. In this case, it is sufficient to change the position of the stopper portion 20 of the stopper ring 5 in accordance with the position of the fixing members 6.

[0052] When a fixing bolt is used as the fixing member 6, the position of the fixing bolt 6 in the longitudinal direction is changed by changing the insertion direction of the collar 7 equipped with the locking flange 30, but if the position of the tip 6a of the fixing member 6 can be adjusted so that the stem 3 (valve body 2) can be changed to either a fixed state or a rotatable state (unfixed state), a part other than the collar 7 may be provided. For example, when the stem 3 is in an unfixed state, a washer (not shown) may be attached between the fixing bolt 6 and the spacer 4, and when the stem 3 is fixed, the washer may be removed. In this case, by making it possible to attach the removed washer to a part such as the valve box 1, it is possible to prevent the washer from being lost when not in use.

[0053] Next, a procedure and operation for fixing the stem 3 (valve 2) in the above embodiment of the fixing device for the valve body of the present invention will be described. Fig. 1 shows a rotatable state of the stem 3 (valve body 2) of a butterfly valve to which a valve body fixing device is applied. In this case, as shown in Fig. 4, the collar 7 is attached to the spacer 4 with the locking flange 30 located in front of the opening 23. When the fixing bolt 6 is screwed into the female thread 22 and tightened, the head 31 is locked with the locking flange 30, preventing the fixing bolt 6 from being screwed further inward, restricting tightening, and the tip 6a is separated from the flat surface portion (stopper portion) 20. Therefore, the stem 3 is in an unfixed state and can be rotated, and the valve body 2 can be rotated through the stem 3 by the reducer 9.

[0054] When the reducer 9 is replaced or maintained due to deterioration or failure of the reducer 9, the stem 3 is first rotated approximately 90° by the reducer 9 from the valve closed state shown in Fig. 1 to the valve open state, and in this state the fixing bolt 6 is loosened and removed from the spacer 4 using a general-purpose tool (not shown). At this time, the male thread 24 is caught on the inner periphery of the locking flange 30, so that the collar 7 can be easily removed at the same time as the fixing bolt 6. If the collar 7 remains inside the opening 23, the collar 7 can be easily removed by hooking an appropriate tool onto the inside of the locking flange 30 and pulling it out.

[0055] 2, the insertion direction of the collar 7 relative to the axial direction is changed, and the collar 7 is inserted into the opening 23 so that the locking flange 32 is at the rear, and the fixing bolt 6 is screwed into the female thread 22. At this time, since the locking flange 30 is located at the rear of the opening 23, the tip 6a of the fixing bolt 6 is pressed against the flat portion 20 before the head 31 is locked with the locking flange 30.

[0056] When the fixing bolt 6 is further tightened from this state, the tightening torque is used to cause the tip 6a to press the flat portion 20 in a surface contact state from a direction approximately perpendicular to the axial direction of the stem 3, exerting a strong frictional force on the stem 3 and applying a force in a direction that maintains its stopped rotation. This stops the stem 3 from rotating in the open state and fixes it, restraining the valve body 2 in a state where water supply is not cut off. Fixing the valve body 2 in this way also suppresses vibration of the valve body 2 due to backlash in the reduction mechanism of the reducer 9. In this state, the reducer 9 can be removed for replacement or maintenance.

[0057] By making the outer diameter of the stopper ring 5 larger than the outer diameter of the stem 3, the distance from the center of the stem 3 to the flat portion 20 becomes longer, and the moment for suppressing the rotational torque of the stem 3 can be increased, thereby increasing the force for stopping the rotation of the stem 3. In this manner, since the stopper ring 5 (stem 3) is fixed by pressing the fixing bolt tip 6a against the flat portion 20, there is no need to finely rotate the stopper ring 5 to align it when the fixing bolt 6 is tightened.

[0058] 2, by providing the fixing bolts 6 in two places on the side of the spacer 4, the two fixing bolts 6 can double the fastening force on the stem 3, and since the two fixing bolts 6 are spaced at an interval of approximately 90°, in addition to the force applied in the fastening direction of each fixing bolt 6, the resultant force of the fastening directions of the fixing bolts 6 can also be applied to the stem 3. This makes it possible to significantly improve the force preventing the stem 3 from rotating.

[0059] As described above, the fixing device for the valve body of the present invention is configured such that the stopper ring 5 is fixed to the outer periphery of the stem 3 located within the spacer 4, and the flat portion 20 against which the tip 6a of the fixing bolt 6 is pressed is formed on the outer periphery of this stopper ring 5, so that the strength of the stem 3 can be ensured without special processing of the stem 3 or forming the stem 3 with a large diameter. In this case, by utilizing the spacer 4 provided between the valve box 1 and the reducer 9 and fixing using the stopper ring 5 provided within this spacer 4 and the fixing bolt 6, no external parts such as fixtures are required, and the work can be easily performed even in a narrow work space.

[0060] During work, the stem 3 can be easily fixed by tightening the fixing bolt 6 with the stem 3 fully open, and the tightening torque exerts sufficient tightening force to reliably maintain an uninterrupted water supply. This makes it possible to remove the reducer 9 in this uninterrupted water supply state and replace or perform maintenance on the reducer 9, or to change the installation direction of the reducer 9 and remount it to change the valve opening direction.

[0061] In the above embodiment, the stem 3 (valve element 2) stopped in the fully open state is fixed, but the stem 3 (valve element 2) in the fully closed state can also be fixed in the same manner as above using the fixing bolt 6. In this case, the stem 3 can be fixed in a state where its rotation is reliably prevented in the fully closed state, making it possible to exhibit excellent water stopping properties.

[0062] In either case above, when releasing the fixed state of the stem 3 and returning this stem 3 (valve element 2) to a state in which it can be rotated, the fixing bolt 6 and collar 7 are removed from the spacer 4 again, and then the collar 7 is inserted into the opening 23 with the locking flange 30 facing forward, and the fixing bolt 6 is screwed into the spacer 4 from above the collar 7. In this way, the valve element 2 can be switched between a rotatable state and a fixed state without the need for complicated operations.

[0063] Whether the valve body 2 is in an unfixed state or a fixed state, the fixing bolt 6 and collar 7 are integrally incorporated into the spacer 4, so that the fixing bolt 6 and collar 7 will not come off the spacer 4 naturally and can be prevented from being lost.

[0064] The fixing bolt 6 is a general-purpose hexagon socket bolt, so a mass-produced product can be used without having to be manufactured separately, and the collar 7 is easily manufactured because it is cylindrical with a locking flange 30 on its inner circumference. Furthermore, the stem 3 is easily machined because it only requires that the upper reduced diameter portion 3a be formed to a length that allows the stopper ring 5 and the output shaft 40 of the reducer 9 to be attached, and that the key grooves 13 be formed at the mounting positions for the stopper ring 5 and the output shaft 40.

[0065] The stopper ring 5 can be attached and detached from above the reduced diameter portion 3a of the stem 3 to which the key 14 is attached, making it easy to install and remove, and it can be attached while being accurately aligned with the stem 3 through the key 14. By attaching the stopper ring 5 to the stem 3 through the key 14 in this way, loosening can be prevented and rattling of the stem 3 can be suppressed during assembly.

[0066] Since the flat surface 20 is formed on the outer peripheral surface of the stopper ring 5, which is separate from the stem 3, this flat surface 20 can be easily formed, and by fixing the stopper ring 5 to the stem 3 using the key 14 as described above, the orientation of the flat surface 20 when fully open or fully closed can be accurately positioned. Therefore, the stem 3 can be firmly fixed by accurately pressing the fixing bolt tip 6a from a substantially vertical direction against the flat surface 20 when fully open or fully closed.

[0067] Two rubber O-rings 35 are provided on the inner diameter of the O-ring case 8 shown in FIG. 5 toward the lower side, and these O-rings 35 ensure the sealing between the stem 3 and the O-ring case 8 to prevent leakage. Furthermore, a durable O-ring 36 made of fluororubber is attached to the upper end opening side above these two O-rings 35, so that even if the two O-rings 35 deteriorate and cause leakage, the upper O-ring 36 can reliably prevent leakage to the outside. On the other hand, two rubber O-rings 35 are provided on the outer diameter of the O-ring case 8 shown in FIG. 5, and these multiple O-rings 35 ensure the sealing between the O-ring case 8 and the valve box 1 to prevent leakage.

[0068] 7 shows a second embodiment of a butterfly valve using a valve body fixing device of the present invention. In this and subsequent embodiments, the same parts as those in the previously described embodiments are designated by the same reference numerals, and the description thereof will be omitted.

[0069] In this embodiment, two mounting holes 21 are formed at an interval of approximately 180° on the side of the spacer 4, each penetrating to the stem insertion hole 16, and these mounting holes 21 are provided by the above-mentioned female thread 22 and opening 23. The fixing bolts 6 are provided at two locations at an interval of approximately 180° on the spacer 4 through the opening 23 and the female thread 22, and each fixing bolt 6 can be pressed against a flat portion 20 at an opposing position on the outer circumferential surface of the stopper ring 5 to fix the stem 3 in a fully open or fully closed state.

[0070] In this way, even if the spacing between the fixing bolts 6 is changed to approximately 180°, just as in the case where they are arranged at intervals of approximately 90° as described above, the stopper ring 5 can be easily regulated to the valve open or closed state by pressing the tip 6a against the flat portion 20, thereby stopping the rotation of the stem 3 and reliably maintaining the valve body 2 fixed in the specified position.

[0071] FIG. 8 shows a third embodiment of a butterfly valve using a valve body fixing device of the present invention. In this butterfly valve, stopper grooves 50 of a predetermined width and depth are formed as stopper portions at four locations at intervals of approximately 90° along the axial direction of the stopper ring 5 on the outer peripheral surface of the stopper ring 5 formed in a cylindrical shape. Meanwhile, fixing members 51 are arranged at two locations at intervals of approximately 90° on the side portion of the spacer 4, and a male thread 52 is formed on this fixing member 51, and a cylindrical locking portion 53 that can be locked into the stopper groove 50 is formed at the tip of this male thread 52. This locking portion 53 is formed with a diameter smaller than that of the male thread 52 and with a predetermined length.

[0072] With this configuration, when the fixing member 51 is tightened with the stem 3 rotated fully open or fully closed, the locking portion 53 locks into the stopper groove 50 to fix the stem 3. At this time, the fixing members 51 arranged at approximately 90° intervals press the stem from two points perpendicular to the axis of the stem 3 with their axes overlapping, and the axis of the fixing bolts at these two points can be aligned with the axis of the stem, so that the stem can be centered and fixed in a state where eccentricity is prevented.

[0073] FIG. 9 shows a cross-sectional view of a main portion near a spacer in a fourth embodiment of a butterfly valve using a valve body fixing device of the present invention. In this embodiment, a key groove 19 is formed at a predetermined position on the stopper ring 5 so that when the stem 3 to which the stopper ring 5 is attached is set to an intermediate opening degree, the tip 6a of the fixing bolt 6 can be pressed against the flat surface portion 20 of the stopper ring 5 to fix the stem 3. Specifically, the key groove 19 is provided at a predetermined position on the stopper ring 5 so that the tip 6a of the fixing bolt can be pressed against the flat surface portion 20 when the stem 3 is set to an intermediate opening degree where the angle θ is approximately 60° from the fully closed state.

[0074] In this way, by changing the position of the key groove 19 of the stopper ring 5, the stem 3 can be fixed at an intermediate opening angle of approximately 60°. When fixing the stem 3, the stem 3 is rotated to the intermediate opening angle while adjusting the angle (orientation) of the flat portion 20, and then the tip 6a is pressed against the flat portion 20 and the fixing bolt 6 is tightened, thereby easily positioning the valve body 2 at the intermediate opening angle and fixing it. Furthermore, by forming a key groove 19 in advance on the stopper ring 5 at a position that can be set to various intermediate opening degrees (valve opening degrees), it becomes possible to fix the valve body 2 at the desired intermediate opening degree by replacing the stopper ring 5.

[0075] Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the description of the embodiment, and various modifications can be made without departing from the spirit of the invention described in the claims of the present invention. [Explanation of symbols]

[0076] 1 Valve box 2 Valve body 3. Stem 4 Spacer 5 Stopper Ring 6 Fixing bolt (fixing member) 6a Tip 7 Color 8 O-ring case 9 Reducer 11 Shaft mounting 20 Flat surface (stopper) 23 Opening 30 Locking flange 31 Bolt Head 35, 36 O-ring 50 Stopper groove (stopper part) 51 Fixing member 53 Locking part

Claims

1. A valve body fixing device comprising: a valve body provided within a valve box and rotatably supported by a stem; a reducer is detachably mounted on the shaft mounting portion to which the stem is shaft mounted via a spacer; a stopper portion is provided on the outer periphery of the stem located within the spacer; a fixing member is disposed on a side portion of the spacer; and the fixing member is pressed against or engaged with the stopper portion to stop the rotation of the stem and fix the valve body in a predetermined position.

2. 2. The valve body fixing device according to claim 1, wherein the stopper portion is a flat portion or a stopper groove formed on an outer peripheral surface of a stopper ring provided integrally with the outer periphery of the stem located within the spacer.

3. 3. The valve body fixing device according to claim 1, wherein the fixing members are disposed at at least two positions on a side of the spacer at a predetermined interval.

4. 4. The valve body fixing device according to claim 1, wherein the fixing member is disposed within the spacer even when the valve body is not fixed.

5. 5. The valve body fixing device according to claim 1, wherein the fixing member is a fixing bolt, the fixing bolt being screwed into the side surface of the spacer so that a tip of the fixing bolt is pressed against or engaged with the stopper portion.

6. The valve body fixing device according to claim 5, wherein the fixing bolt is screwed through a collar so that the valve body will not be fixed even if the fixing bolt is tightened when the valve body is not fixed, and the unfixed state can be visually confirmed from the position of the bolt head.

7. 7. A valve body fixing device as claimed in any one of claims 1 to 6, wherein an O-ring case is provided on the shaft mounting portion, a plurality of O-rings are fitted to the inner diameter portion of this O-ring case, and an O-ring made of fluororubber is fitted to the upper end opening side of the O-ring case.

8. A valve using the valve body fixing device according to any one of claims 1 to 7.

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