JP4641856B2 - Butterfly valve with water filling function - Google Patents

Description

  The present invention relates to a butterfly valve having a filling function, and relates to a technology of a valve that supplies a fluid at a constant flow rate when filling a pipe.

  Conventionally, at the time of initial filling and refilling when laying pipes, the pipe may be damaged by a water hammer or the like when the pipe is full due to sudden filling, so a butterfly valve provided in the middle of the pipe Was opened to a small opening, and the downstream pipe was filled with a small flow rate.

  However, a general butterfly valve is difficult to control the flow rate at a small opening, cannot supply a constant flow rate, and it is difficult to calculate in advance the time required from the start of filling to the full pipe state. It was.

  As a countermeasure against this, as shown in FIG. 5, a main pipe 2 provided with a butterfly valve 1 is provided with a sub pipe 3 for filling water, and a sub pipe valve 4 is provided in the middle of the sub pipe 3. One end of the sub pipe 3 is connected to the main pipe 2 on the upstream side of the butterfly valve 1, and the other end of the sub pipe 3 is connected to the main pipe 2 on the downstream side of the butterfly valve 1.

  According to this, at the time of water filling, the butterfly valve 1 is closed and the sub pipe valve 4 is opened, so that the fluid in the main pipe 2 passes through the sub pipe 3 from the upstream side of the butterfly valve 1 to the butterfly valve. 1 flows downstream, and the downstream pipe is filled with a small flow rate. In general, the diameter of the secondary pipe 3 is set to 1/5 of the diameter of the main pipe 2 according to standards and the like. Therefore, the cross-sectional area of the secondary pipe 3 is 1/25 of the cross-sectional area of the main pipe 2. It has become.

  However, in the case where the sub pipe 3 and the sub pipe valve 4 are provided as described above, there is a problem that a space required for piping installation becomes large. As a countermeasure against such a problem, it is conceivable to use a butterfly valve 10 with a water filling function as shown in FIGS.

  That is, as shown in FIGS. 6 to 8, the valve body 12 is disposed in the vertical direction of the valve stem 13 in the valve box 11 connected between the upstream pipe 20 and the downstream pipe 21. It is rotatably arranged around the core 13a. An annular valve box seal 14 is disposed on the inner peripheral surface of the valve box 11, and the valve body 12 is slidably contacted with the valve box seal 14 at the fully closed position S. The valve body 12 is provided with disc tail portions 15a and 15b in each of a pair of left and right valve body pieces 12a and 12b via a valve rod 13, and the pair of disc tail portions 15a and 15b is a valve body at the time of opening operation. 12 on the back side in the rotational direction A (see FIG. 9).

  Both disc tail portions 15 a and 15 b rise from the plate surface at the peripheral edge of the valve body 12, and have outer circumferential surfaces that are curved in a spherical shape that are in sliding contact with the valve box seal 14. Both disc tail portions 15a and 15b have water passage holes 17, respectively. One end of each water passage hole 17 opens on the outer peripheral surface of the disc tail portions 15a and 15b, and the other end of the disc tail portions 15a and 15b. The back surface of the valve body 12, that is, the back surface side of the valve body 12 during the opening operation.

  As shown in FIG. 9, in one disc tail portion 15a provided in the valve body piece 12a that rotates downstream during the opening operation, the water passage hole 17 has an opening on the back side of the valve body 12 serving as the inlet 17a. The opening on the outer peripheral surface side of the disc tail portion 15a forms the discharge port 17b. Further, in the other disc tail portion 15b provided on the valve disc piece 12b that rotates upstream during the opening operation, the water passage hole 17 has an opening on the outer peripheral surface side of the disc tail portion 15b serving as an inflow port 17c. An opening on the back side of 12 forms a discharge port 17d. In addition, the opening shape of the water passage hole 17 is an oval shape along the circumferential direction of the valve body 12. Note that the total opening area of both the water passage holes 17 is set to be the same as the cross-sectional area of the sub pipe 3 shown in FIG. 5, that is, the pipe 20 connected to the butterfly valve 10, It is 1/25 of the channel cross-sectional area of 21.

The rotation of the valve rod 13 is performed by an opening / closing operation device including a speed reducer and a handle or a motor.
According to this, the valve body 12 is in a fully closed state as shown in FIG. 6 at the beginning of the operation at the time of water filling, and the butterfly valve 10 is opened to a small degree to prevent the pipe from being damaged by sudden water filling. And the downstream pipe is filled with a small flow rate. That is, as shown in FIG. 9, the valve body 12 is opened to a small opening (about 15 to 20%) by the opening operation, and the outer peripheral surfaces of the disc tail portions 15a and 15b are brought into sliding contact with the valve box seal 14. In this state, the water passage hole 17 is fully opened.

  When the water passage hole 17 is fully opened at the small opening of the valve body 12, the upstream region and the downstream region inside the valve box 13 through the valve body 12 are only passed through the water passage holes 17 of the disc tail portions 15a and 15b. The water flowing into the valve box 11 from the upstream pipe 20 is passed through the water passage hole 17 to the downstream pipe 21.

  At this time, since the flow rate flowing through the water flow hole 17 is determined in advance according to the flow path shape such as the flow channel cross-sectional area of the water flow hole 17, the downstream pipe 21 can be filled with a constant flow rate. The required time from the start of filling to the full pipe state can be calculated in advance.

In addition, the butterfly valve 10 with a water filling function in which the valve body 12 includes the pair of disc tail portions 15a and 15b as described above is described in Patent Document 1 below.
However, in the above conventional format, for example, when the fluid is agricultural water or the like, as shown in FIG. 10, foreign matter 22 larger than the width of the water passage hole 17 may be included in the water. There is a problem that such foreign matter 22 is clogged in the inlets 17a and 17c of the water flow holes 17 of the disc tail portions 15a and 15b.

In particular, when the foreign matter 22 is clogged in the inlet 17c of the water flow hole 17 of the other disc tail portion 15b that rotates upstream during the opening operation, the foreign matter 22 is in this state and the other disc tail portion 15b. There is a problem in that the valve body 12 cannot be rotated from the small opening to the fully closed position S by the closing operation.
JP 2003-120829 A

  The present invention prevents the foreign matter from clogging the water passage hole, and prevents the foreign matter from being caught between the outer peripheral surface of the disc tail portion that rotates upstream during the opening operation and the inner peripheral surface of the valve box. An object is to provide a butterfly valve with a water filling function that can be prevented.

In order to achieve the above object, the first invention includes a valve box seal disposed in the valve box, a valve body that rotates around the axis of the valve stem and slides in contact with the valve box seal in the fully closed position, A butterfly valve with a water filling function having a pair of disc tail portions provided on the back side of the valve body in the rotation direction during the opening operation,
The shaft center of the valve stem is provided in the lateral direction or diagonally lateral direction,
The pair of disc tail portions have outer circumferential surfaces curved in a spherical shape that are in sliding contact with the valve box seal,
One disc tail portion that rotates only in the downstream direction from the fully closed position during the opening operation is formed with a water passage hole having one end opened on the outer peripheral surface and the other end opened on the back side of the valve body. ,
A strainer is provided on the inlet side of the water hole ,
When the valve body is opened to a predetermined opening degree, the end surface of the end portion in the rotation direction at the time of closing operation of one of the disc tail portions is directed downward .

  According to this, at the time of filling with water, the valve body is opened to a small opening by the opening operation, and the water passage hole is fully opened in a state where the outer peripheral surfaces of both disc tail portions are in sliding contact with the valve box seal. As a result, the upstream region and the downstream region inside the valve box through the valve body communicate with each other only through the water passage hole, and the fluid flowing into the valve box from the upstream side passes through the water hole to the downstream side. The

  At this time, since the flow rate flowing through the water passage hole is determined in advance according to the flow channel shape such as the flow channel cross-sectional area of the water flow hole, the water can be charged downstream at a constant flow rate. It is possible to calculate in advance the time required to reach the full pipe state.

  In addition, since a strainer is provided in the water passage hole of one disc tail portion, foreign matter in the fluid is prevented from being captured by the strainer and entering the water passage hole when the water is filled. Can be prevented from clogging the water passage hole of one of the disk tail portions.

  Further, when the water passage hole is formed only in one disc tail portion, foreign matter can be prevented from being caught between the outer peripheral surface of the other disc tail portion and the inner peripheral surface of the valve box. Can be reliably rotated from a small opening to a fully closed position by a closing operation.

In addition, by closing another valve or the like provided on the downstream side of the butterfly valve with a water filling function to stop the flow in the valve box of the butterfly valve, in this state, by opening the valve body to a predetermined opening, Since the end surface in the rotational direction at the time of closing operation of one of the disc tail portions faces downward, the foreign matter captured by the strainer falls below the valve body. Thereby, the foreign material captured by the strainer can be easily removed from the valve body.

According to the second aspect of the present invention, when the valve body is opened to a predetermined opening, a drain removing device for discharging the foreign matter captured by the strainer is provided below the end portion in the rotational direction during the closing operation of one disc tail portion. It is what has been.

  As described above, according to the present invention, it is possible to prevent foreign matter from clogging the water passage hole of one disc tail portion. In addition, foreign matter can be prevented from biting between the outer peripheral surface of the other disk tail and the inner peripheral surface of the valve box, and the valve body is reliably rotated from a small opening to a fully closed position by a plugging operation. Can be made. Furthermore, the foreign matter captured by the strainer can be easily removed from the valve body.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In addition, about the same member as the conventional thing mentioned above, the same code | symbol is attached and the description is abbreviate | omitted.
As shown in FIGS. 1 to 3, the water passage hole 17 is formed in one disc tail portion 15 a that rotates downstream during the opening operation, and the other that rotates upstream during the opening operation. It is not formed on the disc tail portion 15b. Further, a thin plate-like strainer 31 made of a wire mesh, a perforated plate, or the like is attached to the inlet 17a side of the water passage hole 17.

  Further, the axis 13a of the valve rod 13 is provided in a horizontal direction (lateral direction) orthogonal to the flow direction, and as shown in FIG. 2, the valve body 12 is fully opened to an opening degree of 100% (an example of a predetermined opening degree). At this time, the butterfly valve 32 with a water filling function is installed so that the end E in the rotation direction B when the one disk tail portion 15a is closed is turned downward.

  In addition, a drain removal device 36 including a drain removal pipe 34 and a drain removal valve 35 is provided at the bottom of the downstream pipe 21. The drainage device 36 is disposed below the end E of one disc tail portion 15a when the valve body 12 is fully opened to an opening degree of 100%.

Hereinafter, the operation of the above configuration will be described.
When the water is filled, as shown in FIG. 1, the valve body 12 is opened to a small opening degree (opening degree: about 15 to 20%) by opening operation, and the outer peripheral surfaces of both disc tail portions 15a and 15b are sealed with a valve box. The water passage hole 17 is fully opened in a state where it is in sliding contact with 14. Thereby, the upstream region and the downstream region inside the valve box 11 via the valve body 12 communicate only through the water passage hole 17, and water (an example of fluid) flowing into the valve box 11 from the upstream side is communicated. Water is passed downstream through the water passage hole 17.

  At this time, the flow rate flowing through the water flow hole 17 is determined in advance according to the flow path shape such as the flow channel cross-sectional area of the water flow hole 17, so that the water can be charged downstream at a constant flow rate. It is possible to calculate in advance the required time from the start to the full pipe state.

  In addition, since the strainer 31 is provided on the inlet 17a side of the water passage hole 17 of the one disk tail portion 15a, the foreign matter 22 contained in the water is captured by the strainer 31 when the water is filled and the water passage hole 17 is filled. This prevents entry of foreign matter into the water passage hole 17 of one of the disc tail portions 15a.

  Further, the water passage hole 17 is formed only in one disk tail portion 15a that rotates downstream during the opening operation, and the other disk tail portion 15b that rotates upstream during the opening operation. Since the foreign matter 22 is not formed, the foreign matter 22 does not clog the water passage hole of the other disc tail portion 15b when the water is filled. It is possible to prevent biting with the peripheral surface, and the valve body 12 can be reliably rotated from the small opening to the fully closed position S by the closing operation.

  Further, another valve (not shown) provided on the downstream side of the butterfly valve 32 with a water filling function is closed to stop the flow of the butterfly valve 32 in the valve box 11, and this state is shown in FIG. As described above, when the valve body 12 is fully opened to the opening degree of 100% (or opened to the vicinity of the opening degree of 100%), the end E of the one disk tail portion 15a faces downward, and thus is captured by the strainer 31. The foreign material 22 falls below the valve body 12. Thereafter, by opening the drain valve 35, the foreign matter 22 is discharged to the outside from the drain pipe 34, whereby the foreign matter captured by the strainer 31 can be easily removed from the valve body 12.

Graphs G1 and G2 in FIG. 4 show the relationship between the opening degree (%) of the valve body 12 and the loss coefficient fv of the butterfly valves 10 and 32.
Here, the filling water flow velocity in the pipe 20 upstream of the butterfly valves 10 and 32 when filling the water through the water passage hole 17 is V (m / s), and the pressure head on the upstream side of the butterfly valves 10 and 32 is When H (m) is assumed and the gravitational acceleration is g (= 9.8 m / s ² ), the loss coefficient fv is obtained by the following equation (1).

fv = H × 2 × g / V ² Formula 1

Among these, the graph G1 drawn by the two-dot chain line relates to the conventional butterfly valve 10 shown in FIGS. 6 to 10, and the water flow holes 17 are formed in both the disk tail portions 15a and 15b, respectively. The total opening area of the water passage holes 17 is set to 1/25 of the flow path cross-sectional area of the pipes 20 and 21.

  When the opening is in the range of 20% or less, the outer peripheral surfaces of the disc tail portions 15a and 15b are in sliding contact with the valve box seal 14, and in the range of 15 to 20%, the water passage holes 17 are fully opened. . According to this, as the opening degree of the valve body 12 increases, the graph G1 tilts downward and the loss factor fv decreases. However, in the range of the opening degree of 15 to 20%, the two water passage holes 17 are fully opened. Therefore, there is a horizontal region Ra in which the loss coefficient fv is a substantially constant value. In addition, at the time of the said water filling, it is used with the opening degree of 20% or less.

  A graph G2 drawn by a solid line relates to the butterfly valve 32 of the present invention shown in FIGS. 1 to 3, and the water passage hole 17 is formed only in one disk tail portion 15a. Net opening area (that is, a value obtained by multiplying the opening area of the water passage hole 17 by the opening ratio of the strainer 31) is approximately ½ of the conventional butterfly valve 10, that is, the flow breaks of the pipes 20 and 21. This is a case where the setting is reduced to approximately 1/50 of the area. As a result, the horizontal region Rb existing in the graph G2 rises higher than the horizontal region Ra in the conventional graph G1. Thus, in the first embodiment, the loss factor fv of the horizontal region Rb can be changed by changing the net opening area of the water passage hole 17.

  Based on this, in the second embodiment described below, the filling in the pipe 20 on the upstream side of the butterfly valve 32 when filling the water from the water passage hole 17 of the one disk tail portion 15a. The water flow velocity V (m / s) and the pressure head H (m) on the upstream side of the butterfly valve 32 are set, and an appropriate value of the loss coefficient fva is determined by the set charging flow velocity V and the pressure head H. Thus, the net opening area of the water passage hole 17 of one of the disk tail portions 15a (= opening area of the water passage hole 17 × opening ratio of the strainer 31) is set so that the horizontal region Rb has the loss factor fva having the appropriate value. ) Is set.

  According to this, the side area Rb corresponds to an opening degree of about 15 to 20%, and at the time of filling, the valve body 12 is filled with a predetermined opening within the opening degree of about 15 to 20%. The loss coefficient fv of the butterfly valve 32 becomes an appropriate loss coefficient fva, and the water is charged at the set charging flow velocity V. At this time, even if the opening degree of the valve body 12 fluctuates slightly from the predetermined opening degree, the fluctuation of the opening degree is included in the horizontal region Rb (that is, within the opening degree of 15 to 20%). As long as this is done, the change in the loss factor fv is reduced, so that the variation in the charging water flow velocity V is reduced, and the variation in the charging water flow rate is suppressed and stabilized. Thereby, the shift | offset | difference of the actual required time until it becomes a full pipe state from the filling start and the time calculated beforehand can be made small.

For example, when the butterfly valve 32 is installed in a water pipe, the pressure head H on the upstream side of the butterfly valve 32 is set to 100 m (= 9.8 × 10 ⁵ Pa) as a standard hydraulic condition of the water pipe. The charging flow velocity V in the upstream pipe 20 at the time of charging is generally set to 0.5 m / s in consideration of safety. Under this condition, the loss factor fv obtained from the above equation 1 is about 8000, and this is a suitable loss factor fva.

  Then, as described above, the net opening area of the water passage hole 17 of one disk tail portion 15a of the butterfly valve 32 is approximately ½ that of the conventional butterfly valve 10, that is, the flow path of the pipes 20 and 21 is cut off. By setting it to approximately 1/50 of the area, as shown in the graph G2 of FIG. 4, the horizontal region Rb exists in the vicinity of the loss factor fva (= about 8000) of an appropriate value.

  As a result, even when the valve body 12 fluctuates slightly from a predetermined opening within the opening of about 15 to 20%, the change in the opening is within the horizontal region Rb (that is, the opening of 15 to 20). %), The change of the loss factor fv (= about 8000) with respect to this becomes small, so the fluctuation of the set charge flow velocity V (= 0.5 m / s) is also reduced. The fluctuation of the charge flow rate is suppressed and stabilized.

  In the above-described embodiment, the net opening area of the water passage hole 17 is set to approximately 1/50 of the flow passage cross-sectional area of the pipes 20 and 21, but may be set to other numerical values. In addition, as standard hydraulic conditions for water pipes, the charging flow velocity V is set to about 0.5 m / s, the pressure head H is set to about 100 m, and an appropriate loss factor fva is set based on these two values. Although it is determined to be 8000, these numerical values are examples and are not limited to these.

  In the above embodiment, when the valve body 12 is fully opened, the axial center 13a of the valve stem 13 is set in a horizontal direction (horizontal (horizontal) perpendicular to the flow direction) so that the end E of one disc tail portion 15a faces downward. Direction), but may be provided in an oblique lateral direction.

  Moreover, in the said embodiment, as shown in FIG. 3, although the one water flow hole 17 is formed in one disk tail part 15a, you may form in multiple numbers. Moreover, although the water flow hole 17 is made into an oval shape, you may make it shapes other than this, for example, a regular circle and a polygon.

  Moreover, in the said embodiment, although the water flow hole 17 and the strainer 31 are provided only in one disk tail part 15a, you may provide in the other disk tail part 15b.

It is a longitudinal cross-sectional view orthogonal to the axial center of the valve stem of the butterfly valve with a water filling function in the first embodiment of the present invention, and shows a state where water is filled by opening the valve body by a small opening. It is a longitudinal cross-sectional view orthogonal to the axial center of the valve stem of a butterfly valve with a water filling function, showing a state where the valve element is fully opened. It is a perspective view of the valve body of a butterfly valve with a water filling function. It is a graph which shows the relationship between the opening degree of a butterfly valve with a water-filling function in 1st Embodiment, and the conventional butterfly valve with a water-filling function, and a loss factor. It is a figure of the water filling mechanism using the conventional subpipe and a subpipe valve. It is a cross-sectional view orthogonal to the axial center of the valve stem of the conventional butterfly valve with a water filling function, and shows a state where the valve body is in the fully closed position. It is a side view of a butterfly valve with a water filling function. It is a perspective view of the valve body of a butterfly valve with a water filling function. It is a cross-sectional view orthogonal to the axial center of the valve stem of the butterfly valve with a water filling function, and shows a state where water is filled by opening the valve body by a small opening. It is a cross-sectional view orthogonal to the axial center of the valve stem of the butterfly valve with a water filling function, and shows a state where foreign matter is clogged in the water passage hole during water filling.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Valve box 12 Valve body 13 Valve rod 13a Shaft center 14 Valve box seal 15a One disk tail part 15b The other disk tail part 17 Water flow hole 31 Strainer 32 Butterfly valve A with a water filling function A Rotation direction B at the time of opening operation Direction of rotation E during closing operation End S of one disk tail S Fully closed position

Claims (2)

A valve box seal placed in the valve box, a valve body that rotates around the shaft center of the valve stem and slides in contact with the valve box seal in the fully closed position, and on the back side of the valve body in the rotational direction during the opening operation A butterfly valve with a water filling function having a pair of disc tail portions provided,
The shaft center of the valve stem is provided in the lateral direction or diagonally lateral direction,
The pair of disc tail portions have outer circumferential surfaces curved in a spherical shape that are in sliding contact with the valve box seal,
One disc tail portion that rotates only in the downstream direction from the fully closed position during the opening operation is formed with a water passage hole having one end opened on the outer peripheral surface and the other end opened on the back side of the valve body. ,
A strainer is provided on the inlet side of the water hole ,
A butterfly valve with a water filling function, characterized in that when the valve body is opened to a predetermined opening degree, the end surface of the end portion in the rotational direction at the time of plugging operation of one of the disc tail portions faces downward . When the valve body is opened to a predetermined opening, a drain removing device is provided below the end in the rotational direction during the closing operation of one of the disk tail portions to discharge foreign matter captured by the strainer. The butterfly valve with a water filling function according to claim 1.

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