JP3378080B2 - Shut-off valve - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shutoff valve for shutting off the flow of a fluid such as a gas. 2. Description of the Related Art In a gas meter, an outlet of the gas meter is used to prevent a fluctuation (pulsation) of gas pressure generated by a device connected downstream of the gas meter from being transmitted to a measuring section of the gas meter or an upstream side of the gas meter. In addition, there have been proposed ones provided with a diaphragm, a punching metal (a metal plate having a large number of holes formed therein), a porous plate such as a sintered metal, or a buffer channel such as a rubber tube. [0003] However, in a gas meter, pressure fluctuations occur on the upstream side of the gas meter depending on the state of the nearby gas meter, the usage state of the nearby gas, and the like. No consideration was given to pressure fluctuations at Therefore, for example, when a fluidic flow meter is used as the gas meter, a problem described below has occurred due to pressure fluctuation on the upstream side. In addition, the fluidic flow meter has a flow path enlarged portion formed by a pair of side walls on the downstream side of the nozzle that generates the jet, and a fluid that has passed through the nozzle is returned to each side wall by a return guide provided outside the side wall. Forming a pair of feedback passages leading to the nozzle outlet side along the outside of the nozzle, utilizing the phenomenon in which the fluid passing through the nozzle flows alternately through the pair of feedback passages, in the direction of flow of the fluid passing through the nozzle. The flow rate of the fluid is measured based on the switching frequency (hereinafter, referred to as an oscillation frequency). When this fluidic flow meter is used,
Oscillation frequency of the fluidic flow meter is disturbed by pressure fluctuations on the upstream side.
In some cases. For this reason, there has been a problem that the error of the measured flow rate increases or the flow rate cannot be measured. Here, an example of a fluidic flow meter used as a gas meter will be described with reference to FIG. The fluidic flow meter includes a main body 10 having an inlet 11 for receiving gas (gas) and an outlet 12 for discharging gas. A partition 13 is provided in the main body 10, a first gas flow path 14 is formed between the partition 13 and the inlet 11, and a second gas flow path 15 is formed between the partition 13 and the outlet 12. Are formed. An opening 16 is provided in the partition 13, and a shutoff valve 17 capable of closing the opening 16 is provided in the first gas flow path 14. A solenoid 18 is fixed to the outside of the main body 10, and a plunger 19 of the solenoid 18 penetrates a side wall of the main body 10 and is joined to the shutoff valve 17. A spring 20 is provided around the plunger 19 between the shutoff valve 17 and the main body 10, and the spring 20 urges the shutoff valve 17 toward the opening 16. And the solenoid 18
Is in the demagnetized state, the plunger 19 projects and the shut-off valve 1
When the solenoid 7 closes the opening 16 and the solenoid 18 is in the excited state, the shut-off valve 17 is separated from the opening 16 and the opening 16 is opened. [0006] A nozzle 21 is provided in the second gas flow path 15 for passing the gas received from the inlet 11 to generate a jet. A rectifying member 22 for regulating the flow of gas is provided upstream of the nozzle 21. Downstream of the nozzle 21, a pair of side walls 23 and 24 that form an enlarged flow path are provided. These side walls 23, 24
A first target 25 is provided on the upstream side and a second target 26 is provided on the downstream side at predetermined intervals. The nozzle 2 is located outside the side walls 23 and 24.
A return guide 29 is provided which forms a pair of feedback flow paths 27 and 28 for returning the gas passing through 1 to the ejection port side of the nozzle 21 along the outer peripheral portions of the side walls 23 and 24. A return guide 29 is provided between each outlet portion of the feedback flow paths 27 and 28 and the outlet portion 12.
A pair of discharge paths 31 and 32 are formed by the back surface of the
Are formed. Pressure sensors 33 and 34 for detecting a change in the direction in which the gas flowing through the nozzle 21 flows are provided near the nozzle 21 of the nozzle 21. As shown in FIG. 8, the gas meter includes:
Shutoff valve 17 that shuts off gas flow in case of emergency such as gas leak
Some have. However, the shutoff valve 17 cannot cut off the flow of gas, but cannot reduce the influence of the pressure fluctuation. The present invention has been made in view of such a problem, and an object of the present invention is to provide a shut-off valve capable of reducing the influence of upstream pressure fluctuation on a flow meter or the like. A shut-off valve according to the present invention has a main valve for covering an opening through which a fluid passes in a fluid flow path, and a main valve disposed in the fluid flow path. A first hole provided in the container and communicating the outside of the container with the fluid storage chamber;
A second hole provided in the main valve for communicating the opening with the fluid storage chamber, a sub-valve capable of closing the second hole, and moving the main valve and the sub-valve to be upstream of the fluid flow path Of the fluid on the side
If the magnitude of the pressure fluctuation does not exceed the predetermined value, the first state in which the opening is opened is selected, and the first state is selected above the fluid flow path.
The magnitude of the pressure fluctuation of the fluid on the flow side exceeds a predetermined value
When you're selects the second opened state of the second hole covers the opening portion by the main valve, flow in the fluid flow path
Depending on the flow rate of the body, and a state selection means for selecting a third state of closing the second hole by the auxiliary valve covers the opening by the main valve, the first hole in the second state, the flow
Upstream of the fluid flow path by the body housing chamber and the second hole
To absorb the pressure fluctuation of the fluid at In this shut-off valve, the main valve and the sub-valve are moved by the state selecting means, and three states are selected. In the first state where the opening is opened, the fluid passes through the opening. In the second state where the opening is covered by the main valve and the second hole is opened, the fluid passes through the first hole, the fluid storage chamber, and the second hole, at which time the pressure fluctuation of the fluid is reduced. You. In the third state in which the opening is covered by the main valve and the second hole is closed by the sub-valve, the flow of the fluid is shut off. Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view showing the configuration of a fluidic flow meter using a shut-off valve according to one embodiment of the present invention. The shutoff valve of the present embodiment is an example of a shutoff valve that shuts off gas flow in a fluidic flow meter used as a gas meter. As shown in FIG. 1, the fluidic flow meter includes a main body 10 having an inlet 11 for receiving gas (gas) and an outlet 12 for discharging gas.
A partition 13 is provided in the main body 10, a first gas flow path 14 is formed between the partition 13 and the inlet 11, and a second gas flow path 15 is formed between the partition 13 and the outlet 12. Are formed. The partition 13 is provided with an opening 16 through which gas passes, and near the opening 16, the shutoff valve 5 of the present embodiment is provided.
0 is provided. FIG. 2 is an enlarged sectional view showing the shut-off valve 50 in FIG. This shut-off valve 50 is disposed in the first gas flow path 14 and is a main valve 51 for covering the opening 16.
And the main valve 51 disposed in the first gas passage 14.
And a container 52 that forms a gas storage chamber 53 therein.
A first hole 54 provided in the container 52 for communicating the outside of the container 52 with the gas storage chamber 53;
And a second hole 55 that communicates between the opening 16 and the gas storage chamber 53 and a second hole 55 that is disposed in the gas storage chamber 53.
Sub-valve 56 capable of closing the hole 55, and an actuator 6 as a state selecting means for moving the main valve 51 and the sub-valve 56
0. The second hole 55 has a smaller diameter than the opening 16, and the first hole 54 has substantially the same diameter as the second hole 55. The actuator 60 is inserted into the first hole 54, one end is connected to the sub-valve 56, and the other end is connected to the main body 1.
A rod 61 penetrating through the side wall of the main body 10 and led out of the main body 10; an actuator main body 62 fixed to the outside of the main body 10 and holding the other end of the rod 61 and moving the rod 61 in the axial direction; A first spring 63 provided around the rod 61 between the back surface of the container 52 and the side wall of the main body 10 and biasing the container 52 toward the opening 16; A second valve is provided around the rod 61 between the first and second valves to bias the sub-valve 56 toward the opening 16.
And a spring 64. Actuator body 62
Is a drive means such as a proportional solenoid or a linear motor, which can switch the axial position of the rod 61 in at least three steps. In the shut-off valve 50 of this embodiment, the main valve 51 and the sub-valve 56 are moved by the actuator 60 to open the opening 16, and the main valve 51 covers the opening 16 and the second state. The second state in which the hole 55 is opened, the opening 16 is covered by the main valve 51 and the sub-valve 56
Thus, the third state in which the second hole 55 is closed can be selected. In the second gas passage 15, there is provided a nozzle 21 for passing the gas received from the inlet 11 to generate a jet. A rectifying member 22 for regulating the flow of gas is provided upstream of the nozzle 21. Downstream of the nozzle 21, a pair of side walls 23 and 24 that form an enlarged flow path are provided. These side walls 23, 24
A first target 25 is provided on the upstream side and a second target 26 is provided on the downstream side at predetermined intervals. The nozzle 2 is located outside the side walls 23 and 24.
A return guide 29 is provided which forms a pair of feedback flow paths 27 and 28 for returning the gas passing through 1 to the ejection port side of the nozzle 21 along the outer peripheral portions of the side walls 23 and 24. A return guide 29 is provided between each outlet portion of the feedback flow paths 27 and 28 and the outlet portion 12.
A pair of discharge paths 31 and 32 are formed by the back surface of the
Are formed. Pressure sensors 33 and 34 for detecting a change in the direction in which the gas flowing through the nozzle 21 flows are provided near the nozzle 21 of the nozzle 21. FIG. 3 is a block diagram showing the configuration of a circuit for calculating the flow rate in the fluidic flow meter shown in FIG. 1 and controlling the shutoff valve 50 of the present embodiment. This circuit is
The flow rate calculation unit 41 that receives the outputs of the pressure sensors 33 and 34 and calculates the flow rate, the display unit 42 that displays the flow rate calculated by the flow rate calculation unit 41, and the middle of a pipe connected to the inlet 11 Pressure sensor 71 for detecting the pressure of the gas on the upstream side of the fluidic flow meter
A pressure fluctuation determining unit 72 that determines whether or not the magnitude of the pressure fluctuation exceeds a predetermined value based on the output of the pressure sensor 71; a flow rate calculating unit 41 and the pressure fluctuation determining unit 72; An actuator drive circuit 73 for driving the main body 62 is provided. The flow rate calculation unit 41 binarizes the output of each of the pressure sensors 33 and 34 and pulsates the output, counts the number of pulses per unit time, obtains the switching frequency of the gas flowing through the nozzle 21, for example, This frequency is converted to a flow rate. The flow rate calculating unit 41 controls the actuator driving circuit 73 to drive the actuator main body 62 when the flow rate is equal to or more than a predetermined amount or when the predetermined flow rate is detected for a predetermined time or more. In the third state, the opening 16 is closed to shut off gas. The pressure fluctuation determining section 72 determines, for example, the difference between the maximum value and the minimum value of the output of the pressure sensor 71 within a predetermined time as the magnitude of the pressure fluctuation, and determines whether or not the difference exceeds a predetermined value. judge. Then, the pressure fluctuation determination unit 7
2, when the magnitude of the pressure fluctuation does not exceed the predetermined value, the shut-off valve 50 is set to the first state, the opening 16 is opened, and when the magnitude of the pressure fluctuation exceeds the predetermined value,
With the shut-off valve 50 in the second state, the opening 16 is covered by the main valve 51 and the second hole 55 is opened. The flow rate calculating section 41 and the pressure fluctuation determining section 72 are realized by a microcomputer, for example. Next, the operation of the fluidic flow meter configured as described above will be described. Normally, the inlet 1 of the fluidic flow meter
The gas received from 1 passes through the first gas flow path 14 and the opening 16 and enters the second gas flow path 15. Second
The gas that has entered the gas flow path 15 passes through the rectifying member 22,
It passes through the nozzle 21 and is ejected from the nozzle 21 as a jet. The gas ejected from the nozzle 21 flows along one side wall due to the Coanda effect. Here, it is assumed that the flow first flows along the side wall 23. The gas flowing along the side wall 23 is further returned to the ejection port side of the nozzle 21 through the feedback channel 27 and discharged from the outlet section 12 through the discharge path 31. At this time, the direction of the gas ejected from the nozzle 21 is changed by the gas flowing through the feedback channel 27, and the gas then flows along the other side wall 24. This gas is further returned to the ejection port side of the nozzle 21 through the feedback flow path 28 and discharged from the outlet section 12 through the discharge path 32. Then, the direction of the gas ejected from the nozzle 21 is changed by the gas flowing through the feedback channel 28 this time,
It again flows along the side wall 23 and the feedback channel 27. By repeating the above operation, the gas that has passed through the nozzle 21 is
28 alternately. The switching frequency of this gas flow direction has a correspondence with the flow rate. The switching frequency of the direction in which the gas flows through the nozzle 21 is determined by the flow rate calculation unit 41 based on the outputs of the pressure sensors 33 and 34. The flow rate calculation unit 41 calculates the flow rate from the determined frequency and displays the flow rate on the display unit 42. Next, the operation of the shut-off valve 50 of this embodiment will be described with reference to FIGS. First, when the pressure fluctuation judging section 72 judges that the magnitude of the pressure fluctuation on the upstream side of the fluidic flow meter does not exceed a predetermined value, the actuator main body 62 is driven by the actuator driving circuit 73, and FIG. As shown in FIG. 5, the shutoff valve 50 is set to the first state. That is, the rod 61 is brought into the most retracted state, the main valve 51 is separated from the opening 16, and the opening 16 is opened. In this state, the gas passes through the opening 16 and enters the second gas passage 15 from the first gas passage 14. On the other hand, when the pressure fluctuation judging section 72 judges that the magnitude of the pressure fluctuation on the upstream side of the fluidic flow meter exceeds a predetermined value, the actuator main body 62 is driven by the actuator driving circuit 73, and FIG. As shown in FIG. 6, the shutoff valve 50 is set to the second state. That is, the retracted amount of the rod 61 is set to an intermediate state, the opening 16 is covered by the main valve 51, the sub-valve 56 is separated from the second hole 55, and the second hole 55 is opened. In this state, the gas enters the gas storage chamber 53 through the first hole 54, passes through the gas storage chamber 53, passes through the second hole 55, and the opening 16, and passes through the first gas passage 1.
4 and enters the second gas flow path 15. In this case, the first hole 54 and the second hole 55 act as a throttle. When the gas having the pressure fluctuation passes through the first hole 54, the gas storage chamber 53, and the second hole 55, first, the pulsation component of the pressure fluctuation is reduced in the first hole 54 acting as the upstream throttle. Is done. Next, in many cases, the time when the pressure fluctuation wave that has passed through the first hole 54 reaches the second hole 55 is different from an integral multiple of 1/2 of the cycle of the pressure fluctuation wave (pulsation component).
In the second hole 55, an action of mutually canceling the pulsation components occurs, and the pulsation components are reduced. FIG. 4 shows an electric equivalent circuit of a structure including the first hole 54, the gas storage chamber 53, and the second hole 55. In this figure, a first hole 54 is a resistor 81
, The second hole 55 corresponds to the resistor 82, the gas accommodating chamber 53 corresponds to the capacitor 83, and the resistors 81 and 82 connected in series and the midpoint between the resistors 81 and 82 are connected. A circuit connected to the ground via the capacitor 83 constitutes a high frequency component removing filter. in this way,
The structure including the first hole 54, the gas storage chamber 53, and the second hole 55 functions as a high-frequency component removing filter that reduces a pulsating component of pressure fluctuation. When the flow rate calculating section 41 detects a flow rate equal to or more than a predetermined amount, or when a predetermined flow rate is detected for a predetermined time or longer, the actuator driving circuit 73 drives the actuator main body 62, as shown in FIG. Thus, the shutoff valve 50 is set to the third state. That is, the rod 61 is brought into the most protruding state, and the main valve 51 opens the opening 16.
Is covered, the second hole 55 is closed by the sub-valve 56, the opening 16 is closed, and the supply of gas (gas) to the downstream side of the fluidic flow meter is stopped. As described above, the shut-off valve 5 of this embodiment
According to 0, in the second state in which the opening 16 is covered by the main valve 51 and the second hole 55 is opened, the gas passes through the first hole 54, the gas storage chamber 53, and the second hole 55. At this time, the fluctuation in gas pressure is reduced, so that the oscillation frequency of the fluidic flow meter is stabilized. The present invention is not limited to the above embodiment,
For example, the shut-off valve 50 may be provided in the second gas flow path 15 to close the opening 16 from the downstream side. In this case, in the second state, the gas flows through the second hole 55,
The gas passes through the gas chamber 53 and the first hole 54 in this order. In the above embodiment, the shut-off valve used for the fluidic flow meter has been described. However, the shut-off valve of the present invention can be used for a flow meter other than the fluidic flow meter. Instead, it can also be used as a shut-off valve that shuts off the flow of liquid. As described above, according to the shut-off valve of the present invention, in the second state in which the main valve covers the opening and the second hole is opened, the fluid flows through the first hole, Since the pressure fluctuation of the fluid when passing through the fluid storage chamber and the second hole is reduced, there is an effect that the influence of the pressure fluctuation on the upstream side on the flow meter and the like can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a configuration of a fluidic flow meter using a shut-off valve according to one embodiment of the present invention. FIG. 2 is an enlarged sectional view showing a shut-off valve in FIG. FIG. 3 is a block diagram showing a configuration of a circuit for calculating a flow rate and controlling a shutoff valve according to an embodiment of the present invention in the fluidic flow meter shown in FIG. 1; FIG. 4 shows a first hole in a shutoff valve according to an embodiment of the present invention;
FIG. 4 is a circuit diagram showing an electrical equivalent circuit of a structure including a gas storage chamber and a second hole. FIG. 5 is a sectional view showing a first state of the shut-off valve according to one embodiment of the present invention; FIG. 6 is a sectional view showing a second state of the shut-off valve according to one embodiment of the present invention. FIG. 7 is a sectional view showing a third state of the shut-off valve according to one embodiment of the present invention; FIG. 8 is a sectional view showing an example of a fluidic flow meter. DESCRIPTION OF SYMBOLS 11 Inlet 12 Outlet 14 First gas flow path 15 Second gas flow path 16 Opening 50 Shut-off valve 51 Main valve 52 Container 53 Gas storage chamber 54 First hole 55 Second hole 56 Sub valve 60 Actuator 61 Rod 62 Actuator body

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-290281 (JP, A) JP-A 64-781 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16K 17/36 F16K 31/06

Claims (1)

Claims: 1. A main valve for covering an opening through which a fluid passes in a fluid flow path, and a main valve disposed in the fluid flow path and coupled to the main valve. A container forming a fluid storage chamber therein; a first hole provided in the container, for communicating the outside of the container with the fluid storage chamber; a opening provided in the main valve, the opening and the fluid storage chamber A second valve for communicating with the second valve, a sub-valve capable of closing the second hole, moving the main valve and the sub-valve, and upstream of the fluid flow path.
The magnitude of the pressure fluctuation of the fluid on the side exceeds a predetermined value
If not , the first state in which the opening is opened is
Select the fluid flow upstream of the fluid flow path.
When the magnitude of the pressure fluctuation exceeds a predetermined value , the main valve covers the opening and selects the second state in which the second hole is opened, and selects the second state in the fluid flow path.
A third valve in which the opening is closed by the main valve and the second hole is closed by the auxiliary valve according to the flow rate of the fluid;
State selecting means for selecting the state of
In the state, the first hole, the fluid storage chamber, and the
A second hole upstream of the fluid flow path
A shut-off valve for absorbing pressure fluctuation of the fluid .