JP2004100804A - Valve opening/closing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve opening/closing machine preventing water hammer by automatically delaying a valve closing speed of a valve element in a small opening region than a valve closing speed in a region except for the small opening region. <P>SOLUTION: This valve opening/closing machine is provided with an input shaft 50, an output shaft 51 connected to a valve stem 3, and a power transmission means 7 interposed between the input shaft 50 and the output shaft 51. The power transmission means 7 is provided with a worm 70 provided in the input shaft 50, a Geneva worm wheel 71 provided in the output shaft 51 and geared with the worm 70, a worm wheel 73 provided in an intermediate shaft 72 and geared with the worm 70, an intermediate small gear 74 provided in the intermediate shaft 72, and a Geneva large gear 75 provided in the output shaft 51 to be geared with the intermediate small gear 74. The valve closing speed in the small opening region of the valve element 2 is automatically delayed than the valve closing speed in the region except for that. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a valve opening / closing operation device, and more particularly to a valve opening / closing operation device designed to automatically prevent water hammer.
[0002]
[Prior art]
BACKGROUND ART Conventionally, for example, there is a butterfly valve which is frequently used in a water supply piping system for water supply, industrial water, agricultural water, and the like (for example, see Patent Document 1). As shown in FIGS. 5 and 6, such a butterfly valve includes a valve box 1, a valve element 2 and a valve rod 3, and the valve element 2 to which the valve rod 3 is attached includes a valve box 1 and a water supply piping system 4. Is accommodated in the valve box 1 so as to be rotatable around the axis C2 of the valve stem 3 at the same time as the valve stem 3, and the valve body of the valve body 2 is rotated by the rotation of the valve body 2. The sheet 2A is configured to open and close while being in contact with and separated from the inner surface of the valve box 1, specifically, the valve box sheet 1A. The inner surface of the valve box 1 has a uniform inner diameter and extends in the direction of the axis C1, and its cross-sectional shape is a perfect circle.
In the butterfly valve configured as described above, when the valve body 2 is rotated clockwise from the fully closed position shown by the solid line in FIG. 6 to the fully open position shown by the two-dot chain line, the rotation angle of the valve body 2 increases. The interval on the rotation trajectory of the valve box sheet 1A of the valve box 1 and the valve sheet 2A of the valve body 2 is increased, and the cross-sectional area of the fluid flowing down is enlarged, so that the flow rate can be increased. When the valve body 2 is rotated counterclockwise from the fully open position shown by the two-dot chain line to the fully closed position shown by the solid line, the valve box seat 1A of the valve box 1 and the valve of the valve body 2 The interval on the rotation trajectory of the body sheet 2A is reduced, and the cross-sectional area of the flowing fluid is reduced, so that the flow rate can be reduced or made zero. Therefore, from the state of the flow rate 0 where the valve body 2 is positioned at the fully closed position indicated by the solid line with the rotation angle of 0 degrees, the valve body is moved within the range of the maximum flow rate positioned at the fully open position indicated by the two-dot chain line with the rotation angle of 90 degrees. The flow rate can be adjusted according to the rotation angle.
[0003]
[Patent Document 1]
JP-A-2002-213622 (FIG. 4)
[0004]
[Problems to be solved by the invention]
By the way, when the pressure of the fluid F in the water supply piping system 4 is high, if the valve body 2 is rapidly closed, a rapid change occurs in the flow velocity of the fluid F, causing a sharp increase in pressure and causing a water hammer (water hammer). appear. That is, when the valve element 2 at the fully open position shown by the two-dot chain line in FIG. 6 is rotated approximately 90 degrees counterclockwise to the fully closed position shown by the solid line, the opening (θ) shown by the one-dot chain line is about 30 degrees. If the valve closing speed is high (high) in the small opening range within a degree, a water hammer is generated due to a sudden increase in the differential pressure.
[0005]
Therefore, in order to prevent water hammer with a butterfly valve or other rotary type valve whose diameter and specifications are determined, the valve body 2 in the small opening region where the opening (θ) is within about 30 degrees is used. It was necessary to take measures to artificially slow (lower) the valve closing speed.
[0006]
On the other hand, opening and closing of the valve element 2 is generally performed by an output of an opening and closing operation device of a valve connected to the valve rod 3. As a conventional valve opening / closing operation device, for example, those shown in FIGS. 7 and 8 are known. 7 and 8, a valve opening / closing operating device 5 includes an input shaft 50 to which a valve opening / closing operation force is input, and an input / output shaft 50 that rotates simultaneously with the input shaft 50 to output the opening / closing operation force. 6, an output shaft 51 rotatably connected to the valve stem 3 via the shaft 6, and a power transmission interposed between the input shaft 50 and the output shaft 51 for transmitting the rotational operation force of the input shaft 50 to the output shaft 51. The power transmission means 7 includes a worm 70 provided on the input shaft 50, and a worm wheel 71 provided on the output shaft 51 and meshing with the worm 70. It is freely supported.
[0007]
Now, with the valve body 2 shown in FIG. 6 in the fully closed position shown by the solid line, the input shaft 50 of the valve opening / closing device 5 shown in FIGS. 7 and 8 is rotated in the valve opening direction by the valve opening / closing operation force. Then, this rotation is transmitted to the valve stem 3 through the path of the worm 70 → the worm wheel 71 → the output shaft 51 → the coupling 6, and the valve stem 3 is rotated in the valve opening direction, so that the valve element 2 It can be rotated to the fully open position indicated by the two-dot chain line. Conversely, in the state where the valve body 2 in FIG. 6 is in the fully open position indicated by the two-dot chain line, the input shaft 50 of the valve opening / closing operating device 5 shown in FIGS. This rotation is transmitted to the valve stem 3 through the path of the worm 70 → the worm wheel 71 → the output shaft 51 → the coupling 6, and the valve stem 3 is rotated in the valve closing direction to rotate the valve body 2 in FIG. Can be rotated to the fully closed position indicated by the solid line.
[0008]
Therefore, in the case of a manual valve opening / closing device 5 in which the valve opening / closing operation force is input to the input shaft 50 by human power, the valve body 2 in the small opening region where the opening (θ) is within about 30 degrees. Water hammer can be prevented by taking measures to artificially slow (lower) the valve closing speed. However, in the case of an automatic valve opening / closing device 5 in which a valve opening / closing force is input to the input shaft 50 by an electric motor (not shown), the opening / closing speed is constant regardless of the opening range of the valve body 2. Therefore, the valve closing speed of the valve element 2 in the small opening region cannot be automatically made lower (lower) than the valve closing speed in the region other than the small opening region, thereby preventing the water hammer. Could not.
[0009]
The present invention has been made in view of such circumstances, and automatically reduces a valve closing speed of a valve body in a small opening region to a valve closing speed in a region other than the small opening region, thereby providing water. It is an object of the present invention to provide a valve opening / closing device capable of preventing a hammer.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a valve opening / closing device according to the present invention is rotatably housed in a valve box, and is simultaneously rotatably mounted on a valve body for closing and opening the inside of the valve box. In a valve opening / closing device that rotationally drives the valve stem around its axis, an input shaft to which a valve opening / closing operation force is input, and the input shaft rotates simultaneously to output the opening / closing operation force, An output shaft connected to the valve shaft so as to be rotatable at the same time; and a power transmission unit interposed between the input shaft and the output shaft to transmit a rotational operation force of the input shaft to the output shaft. Is characterized in that the opening and closing speed of the valve element in the small opening region is made lower than the opening and closing speed of the region other than the small opening region so that the transmission can be performed.
[0011]
According to the present invention, the power transmission means for transmitting the rotational operating force of the input shaft to the output shaft reduces the opening / closing speed of the valve body in the small opening region to be lower than the opening / closing speed in the region other than the small opening region. With this configuration, the opening / closing speed of the valve body in the small opening region is automatically lower than the opening / closing speed in the region other than the small opening region. That is, the water hammer can be prevented by setting the valve closing speed of the valve body in the small opening region to be lower than the valve closing speed in the region other than the small opening region.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings. The same or corresponding parts as those of the conventional example are denoted by the same reference numerals and described.
FIG. 1 is a front view showing an embodiment of the present invention, and FIG. 2 is a plan view of FIG. In these figures, a valve opening / closing operating device 5 is provided with an input shaft 50 to which a valve opening / closing operation force is input, and simultaneously rotates with the input shaft 50 to output the opening / closing operation force, and via a coupling 6. A power transmission means 7 interposed between the input shaft 50 and the output shaft 51 for transmitting the rotational operating force of the input shaft 50 to the output shaft 51; It has.
[0013]
The power transmission means 7 includes a worm 70 provided on the input shaft 50, a Geneva worm wheel 71 provided on the output shaft 51 and meshing with the worm 70, and a worm 70 provided on an intermediate shaft 72 parallel to the output shaft 51 and meshing with the worm 70. A worm wheel 73, an intermediate small gear 74 provided on the intermediate shaft 72, and a Geneva large gear 75 provided on the output shaft 51 so as to mesh with the intermediate small gear 74, are housed in the casing 8, and are rotatable. It is supported by. The input shaft 50 is driven to rotate by an electric motor (not shown).
[0014]
In the above configuration, in a state where the valve body 2 in FIG. 6 is in the fully closed position indicated by the solid line, the Geneva worm wheel 71 of the power transmission means 7 in the valve opening / closing operating device 5 does not engage with the worm 70 as shown in FIG. , A Geneva large gear 75 meshes with the intermediate small gear 74. When the input shaft 50 of the valve opening / closing device 5 shown in FIGS. 1 and 2 is rotated in the valve opening direction by a valve opening / closing operation force by an electric motor (not shown), this rotation is performed by the worm 70 → the worm wheel 73 → intermediate. The shaft 72 → the intermediate small gear 74 → the Geneva large gear 75 → the output shaft 51 → is transmitted to the valve stem 3 through the path of the coupling 6, and is transmitted to the worm wheel 73, the intermediate small gear 74, the Geneva large gear 75, the output shaft 51 and the Geneva worm. Each of the wheels 71 starts rotating in the direction of the solid arrow in FIG. 2, and this rotation is transmitted to the valve stem 3 through the path from the output shaft 51 to the coupling 6 to rotate the valve stem 3 in the valve opening direction.
[0015]
Since the speed reduction mechanism is configured by setting the gear ratio between the Geneva large gear 75 and the intermediate small gear 74 to be large, while the Geneva large gear 75 is engaged with the intermediate small gear 74, that is, the Geneva large gear 75 During rotation from the position 2 to the position in FIG. 3 at a rotation angle of, for example, about 30 degrees, the valve body 2 indicated by the solid line in FIG. 6 is opened at the opening indicated by the dashed line (θ = about 30 degrees). The valve opening speed is slow (low).
[0016]
When the valve element 2 is opened to the position shown by the dashed line in FIG. 6 and the valve opening / closing device 5 is rotated in the state shown in FIG. 3, the input shaft 50 of the valve opening / closing device 5 is further rotated in the valve opening direction. This rotation is transmitted to the valve stem 3 through the path of the worm 70 → Geneva worm wheel 71 → Output shaft 51 → Coupling 6, and the Geneva worm wheel 71 and the output shaft 51 rotate in the direction of the solid arrows in FIG. 3, respectively ( At the same time, the worm wheel 73 and the intermediate small gear 74 also rotate in the direction of the solid arrow), and this rotation is transmitted to the valve rod 3 through the path from the output shaft 51 to the coupling 6, and the valve body 2 is moved at a steady valve opening speed. The valve is opened to the fully open position indicated by the two-dot chain line in FIG.
[0017]
In the state where the valve body 2 in FIG. 6 is in the fully open position shown by the two-dot chain line, as shown in FIG. 4, the Geneva large gear 75 of the power transmission means 7 in the valve opening / closing operating device 5 does not mesh with the intermediate small gear 74, Geneva worm wheel 71 meshes with worm 70. When the input shaft 50 of the valve opening / closing device 5 shown in FIG. 4 is rotated in the valve closing direction by the valve opening / closing operation force of the electric motor 9, the worm wheel 73, the intermediate shaft 72, the intermediate small gear 74, and the Geneva worm wheel 71 , The output shaft 51 and the Geneva large gear 75 each start reverse rotation in the direction of the dashed arrow in FIG. 4, and this reverse rotation is transmitted to the valve rod 3 through the path from the output shaft 51 to the coupling 6, and At a steady valve closing speed until the opening (θ = about 30 degrees) indicated by the dashed line in FIG.
[0018]
When the valve body 2 is closed to the position shown by the dashed line in FIG. 6 and the valve opening / closing device 5 is in the state of FIG. 3, the input shaft 50 of the valve opening / closing device 5 is further rotated in the valve closing direction in the reverse direction. This reverse rotation is transmitted to the valve stem 3 through the path of the worm 70 → the worm wheel 73 → the intermediate shaft 72 → the intermediate small gear 74 → the Geneva large gear 75 → the output shaft 51 → the coupling 6, and the worm wheel 73 and the intermediate shaft The intermediate pinion 72, the intermediate small gear 74, the Geneva worm wheel 71, the output shaft 51, and the Geneva large gear 75 are reversely rotated in the directions indicated by broken arrows in FIG. 3 to rotate the valve rod 3 backward in the valve closing direction.
[0019]
Since the speed reduction mechanism is configured by setting the gear ratio between the Geneva large gear 75 and the intermediate small gear 74 to be large, the Geneva large gear 75 is rotated from the position of FIG. 3 to the position of FIG. The valve closing speed during the reverse rotation to close the valve element 2 shown by the dashed line in FIG. 6 to the fully closed position shown by the solid line is suppressed (low).
[0020]
That is, according to the present invention, the valve closing speed of the valve body 2 in the small opening degree region where the opening degree of the valve body 2 is from 0 degree to about 30 degrees or less, for example, is more automatically than the valve closing speed in other regions. Therefore, water hammer can be reliably prevented.
[0021]
【The invention's effect】
As described above, since the valve opening / closing operating device of the present invention is configured, the following special effects can be obtained.
[0022]
That is, the power transmission means for transmitting the rotational operation force of the input shaft to the output shaft is configured to lower the opening / closing speed of the valve body in the small opening region than the opening / closing speed in regions other than the small opening region. Thus, the valve closing speed of the valve body in the small opening degree region is automatically made lower than the valve closing speed in the region other than the other region, and the water hammer can be reliably prevented.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of the present invention.
FIG. 2 is a plan view of FIG. 1 when the valve body is at a fully closed position.
FIG. 3 is a plan view when a valve body is at a boundary position between a small opening area and other opening areas.
FIG. 4 is a plan view when the valve element is at a fully open position.
FIG. 5 is a front view of a butterfly valve to which the present invention is applied.
FIG. 6 is a sectional view taken along line AA of FIG. 5; FIG. 7 is a front view showing an example of a conventional valve opening / closing device.
FIG. 8 is a plan view of FIG. 7;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Valve box 2 Valve element 3 Valve rod 5 Valve opening / closing operation device 7 Power transmission means 50 Input shaft 51 Output shaft

Claims (1)

A valve stem rotatably housed inside a valve box and rotatably attached to a valve body that closes and opens the inside of the valve box so as to be simultaneously rotatable, in a valve opening / closing operating device that rotates around its axis. An input shaft to which a valve opening / closing operation force is input, an output shaft connected to the valve shaft so as to rotate simultaneously with the input shaft and output the opening / closing operation force, and an output shaft connected to the valve shaft; Power transmission means interposed between the shafts for transmitting the rotational operating force of the input shaft to the output shaft, the power transmission means controlling the opening / closing speed of the valve body in the small opening region other than the small opening region. A valve opening / closing operation device configured to be able to transmit at a speed lower than the opening / closing speed of the region.

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