JPH0426886Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is configured to open and close a main valve provided in a pipe line in accordance with changes in the internal pressure of a cylinder chamber. A first pilot flow path that communicates a flow path portion in the valve box upstream of the main valve with the cylinder chamber, and a second pilot flow path that connects a flow path portion of the valve box downstream of the main valve with the cylinder chamber. The present invention relates to an improvement in a flow rate control device including a valve opening adjustment device that automatically adjusts the opening of the main valve.

[Conventional technology]

In this type of flow control device, conventionally, [1] electromagnetic on-off valves V1 and V provided in the first pilot flow path 5 and the second pilot flow path 7, respectively;
2, and the pressure in the cylinder chamber 4 for opening/closing the main valve 2 is automatically adjusted by the controller C which switches the opening/closing valves V1 and V2 to open/close in a contradictory manner according to the set control mode. (See Figure 2 of the drawing).

[2] Adjustment of the opening of the main valve by the differential pressure of the pilot pressure generated between the primary pilot flow path on the upstream side of the main valve and the secondary pilot flow path that communicates with the downstream side of the main valve. (Japanese Patent Application Laid-open No. 59-164477).

The valve opening adjustment device described in [1] and [2] above has been known.

[The problem that the idea attempts to solve]

However, in the conventional type described in the former [1], the electromagnetic on-off valves V1 and V2, which consume a large amount of power,
Frequently opening and closing requires a considerable amount of electricity, and if batteries must be used, large-capacity batteries are required, which poses problems in terms of power costs and power supply equipment costs. , improvements to save power were desired. Furthermore, during a power outage, neither of the electromagnetic on-off valves V1 and V2 could continue to maintain the valve opening position before the power outage, resulting in an uncontrollable state.

In the conventional method described in the latter [2], the pilot valve is controlled by the pilot pressure, so the control itself cannot be performed unless a sufficient differential pressure occurs, and it also prevents temporary pressure fluctuations and flow rate fluctuations in the pipeline. There was a problem that unnecessary movements were likely to occur.

The purpose of this invention is to reduce the power consumption of the valve opening adjustment device compared to those using electromagnetic on-off valves, and to maintain the valve opening during power outages without the need for special auxiliary means. It is an object of the present invention to provide a flow rate control device that can perform reliable control while avoiding as much as possible the influence of the magnitude of the differential pressure and the duration of the differential pressure between the primary side and the secondary side.

[Means to solve the problem]

The technical means of the present invention taken to solve the above-mentioned problems is configured to open and close the main valve provided in the pipe line in accordance with changes in the internal pressure of the cylinder chamber. a first pilot flow path that communicates a flow path portion in the valve box on the upstream side with the cylinder chamber; a second pilot flow path that communicates a flow path portion in the valve box downstream of the main valve with the cylinder chamber; and a flow control device including a valve opening adjustment device that automatically adjusts the opening of the main valve, including the configurations described in [A] and [B] below.

[B] The valve opening adjustment device includes a primary pressure sensor that detects the pressure of the transport fluid on the upstream side of the main valve, and a secondary pressure sensor that detects the pressure of the transport fluid on the downstream side of the main valve. an opening detector for detecting the opening of the main valve; a pilot valve for adjusting the opening provided in one of the first and second pilot flow paths; an electric motor for operating the pilot valve; It consists of a controller that automatically controls the rotation speed or rotation angle of the electric motor.

[B] The controller controls both the sensors, and
Based on information from the angle detector of the main valve,
A control signal for adjusting the valve opening is output to the electric motor so that the internal pressure in the cylinder chamber and the valve opening/closing operation force due to the pressure in the flow path in the valve box upstream of the main valve are balanced. It is equipped with a signal output means.

[Effect]

As a result of taking the above technical means, the following effects can be obtained.

a In other words, when the electric motor is rotated by the controller by the number of rotations or angle of rotation determined by the set control mode, the opening degree of the pilot valve changes in proportion to the number of rotations or angle of rotation. Therefore, in the conventional method, an electromagnetic on-off valve as a pilot valve is provided in each of the upstream pilot flow path and the downstream pilot flow path to selectively open and close either pilot flow path. In comparison, the pressure in the cylinder chamber can be increased or decreased using an electric motor that consumes less power than an electromagnetic on-off valve. The pressure inside the cylinder chamber increases or decreases at a predetermined opening of the pilot valve, which is adjusted to change the resistance to flow from the first pilot passage to the second pilot passage. It is not necessary to provide each of the pilot valves with one on-off valve, which must be used as a pilot valve.

b. Furthermore, since the electric motor is used to adjust the opening of the pilot valve provided in the pilot flow path, even if there is a power outage during operation, the electromagnetic on-off valve can be used as the pilot valve. Unlike when used as a pilot valve, the on-off valve that has been energized to either the open or closed position will not be returned to the position where it is electromagnetically energized at the same time as a power outage, and the pilot valve will not open or close. The predetermined opening degree adjusted by the electric motor is maintained.

Furthermore, since the opening degree of the pilot valve is determined by the adjustment signal given to the electric motor, it is more difficult to open and close the valve than a pilot pressure type valve, which is opened and closed directly by the differential pressure generated in the pilot flow path, for example. Even if the differential pressure in the pilot flow path is not large enough to operate the pilot valve, the opening can be adjusted by providing a sensor that can detect this. When the differential pressure generated in the pilot flow path temporarily fluctuates greatly, there is no need to operate the pilot valve in conjunction with this, so the electric motor is used to reduce unnecessary movement of the pilot valve. It is also possible to control.

[Effect of idea]

As a result, (a) From the effect of a above, it is possible to avoid using an electromagnetic shut-off valve that consumes a lot of power as a pilot valve, and to reduce the number of pilot valves used, thereby improving overall control of the opening of the pilot valve. Power consumption can be reduced.

(b) Due to the effect described in b above, the position of the pilot valve can be maintained even in the event of a power outage, and pressure changes in the cylinder chamber can be regulated, thereby suppressing large changes in the flow rate of the fluid flowing through the pipe line in which the main valve is provided.

C. Due to the effect of c above, the pilot valve can be operated even with a small differential pressure, and the influence of instantaneous changes in the differential pressure in the pilot flow path can be avoided.
It is also advantageous in that it is easy to perform control stably.

〔Example〕

Next, an example will be shown with reference to FIG.

A bottomed cylindrical main valve 2 with a large number of small holes 2a around its periphery is provided in a valve box 3, with the end opening of the main valve 2 facing the upstream channel section F1 in the valve box. . A bottomed cylindrical piston 1 is connected to a main valve 2 by bolts to form a valve box 3.
The main valve 2 slides against the annular valve box side seat 3a as the piston 1 slides, and the number of small holes 2a facing the downstream valve box internal flow path portion F2 is changed. , the flow rate is adjusted.

The cylinder chamber 4 formed by the valve box 3 and the piston 1 has an upstream valve box internal flow path F1 through the first pilot flow path 5, and a downstream internal valve box flow path F2 through the second pilot flow path 7. are connected to each other, and the internal pressure of the cylinder chamber 4 is adjusted by the action of the valve opening adjustment device, which will be described later. It is configured to set the opening degree.

The above-mentioned valve opening adjustment device is constructed by providing a pilot valve 6 in the second pilot flow path 7, an electric motor M for opening and closing the pilot valve 6, and a first sensor for detecting the upstream pressure inside the valve box. 10. Based on information from the second sensor 11 that detects the downstream pressure inside the valve box and the potentiometer 8 that detects the opening degree of the main valve 2, the flow rate on the downstream side of the main valve 2 is set within a set range. To maintain the electric motor M
Controller 1 that automatically controls the rotation speed or rotation angle of
2 are provided.

With this configuration, when the pilot valve 6 provided in the second pilot flow path 7 is opened, the pressure in the cylinder chamber 4 decreases, and the main valve 2 is closed by the upstream pressure inside the valve box 3. When the main valve 2 is opened, the upstream pressure inside the valve box 3 decreases, and the opening degree of the main valve 2 increases until the operating force due to the cylinder chamber 4 pressure and the upstream pressure inside the valve box 3 are balanced.

Conversely, when the pilot valve 6 is closed, the pressure in the cylinder chamber 4 increases and the main valve 2 is closed.
The upstream pressure inside the valve box 3 increases, and the opening degree of the main valve 2 decreases until the operating force due to the cylinder chamber 4 pressure and the upstream pressure inside the valve box 3 are balanced.

[Another example]

Next, another embodiment will be described.

The specific structures of the valve box 3, main valve 2, and pilot valves 6, 6 can be changed in various ways, and for example, gate valve types, butterfly valve types, and other suitable types can be used.

The specific structure for opening and closing the main valve 2 in response to changes in the internal pressure of the cylinder chamber 4, and the specific structure for changing the opening degree of the pilot valves 6, 6 by the electric motor M, can be changed in various ways. For example, the interlocking mechanism may include a reduction part. It is possible to do so.

A pilot valve 6 may be provided in the first pilot flow path 5.

How the pilot valve 6 is automatically operated by the controller 12 can be programmed as necessary, and the specific configuration of the controller 12 can be appropriately selected in accordance with the program to be set. The purpose of the flow control device, the type of target fluid, etc. do not matter.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG.
The figure is a sectional view of a conventional example. 2...Main valve, 4...Cylinder chamber, 5...First pilot flow path, 6...Pilot valve, 7...Second
Pilot flow path, 12...Controller, F1...Upstream valve box flow path portion, F2...Downstream valve box flow path portion, M...Electric motor.

Claims (1)

[Claims for Utility Model Registration] A main valve 2 provided in a pipe is configured to be opened and closed according to changes in the internal pressure of a cylinder chamber 4, and a valve on the upstream side of the main valve 2 A first pilot flow path 5 communicates a flow path portion F1 in the box with the cylinder chamber 4, and a second pilot flow path communicates a flow path portion F2 in the valve box downstream of the main valve 2 with the cylinder chamber 4. 7 and a valve opening adjustment device that automatically adjusts the opening of the main valve 2, and further includes the configurations described in [A] and [B] below. [B] The valve opening adjustment device includes a primary pressure sensor 10 that detects the pressure of the transport fluid on the upstream side of the main valve 2, and a secondary pressure sensor 10 that detects the pressure of the transport fluid on the downstream side of the main valve 2. A sensor 11, an opening detector 8 for detecting the opening of the main valve 2, a pilot valve 6 for adjusting the opening provided in one of the first and second pilot channels 5, 7, and It is comprised of an electric motor M that operates the pilot valve 6, and a controller 12 that automatically controls the rotation speed or rotation angle of the electric motor M. [B] The controller 12 controls both the sensors 1
0, 11, and information from the angle detector 8 of the main valve 2, the internal pressure of the cylinder chamber 4 and the flow path portion F1 in the valve box on the upstream side of the main valve 2 are determined.
A signal output means is provided for outputting a control signal for adjusting the valve opening degree to the electric motor M so that the valve opening/closing operation force due to the pressure is balanced.