JPS6139558B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an opening/closing control device for a valve body used as means for opening and closing a fluid transport pipe.

Accurately knowing the opening amount of the valve body and accurately knowing the opening/closing drive load of the valve body is extremely useful in controlling the flow rate and detecting when a foreign object is caught in the valve body at an intermediate opening. . In the past, for example, the amount of opening of a valve body was determined by mechanically slowing down the rotation speed of the opening/closing drive using a gear, etc., and then using a potentiometer or the like to derive the amount of opening.However, with this configuration, it is possible to accurately determine the amount of opening of a valve body. It was difficult to obtain. In addition, the opening/closing drive load of the valve body is detected by a mechanical mechanism, and if an overload exceeding a set value is detected, it is determined that a trouble has occurred, and the system takes measures such as cutting off the power to the opening/closing drive motor. Although this configuration has been adopted in the past, it required skill to adjust the set values. Therefore, whenever an accident requires adjustment, it is necessary for an experienced person to travel to the site each time, resulting in a large expense burden.
Furthermore, since it was a mechanical load detection mechanism, problems often occurred because the setting accuracy deteriorated due to rust and other effects that occur with long-term use.

The present invention has been made in view of the above-mentioned circumstances, and aims to provide a valve body opening/closing control device that is small, inexpensive, and capable of highly accurate detection of the opening degree of the valve body and the driving load when opening and closing the valve body.

The technical means of the present invention taken to achieve the object are: a constant speed rotation drive device; a reduction mechanism that opens and closes the valve shaft in response to the rotational force of this drive device; and a combination of these drive devices and the reduction mechanism. A means for projecting light toward a rotating member provided in a power transmission system between the two and forming and receiving a light pulse signal proportional to the rotation speed of the rotating member, and a means for integrating the number of light pulses to open the valve body. a mechanism that calculates the frequency, a mechanism that detects fluctuations in the pulse cycle to detect the opening/closing driving load of the valve body, and a mechanism that detects the driving load when the driving load is detected. The valve body is equipped with a mechanism that outputs a stop signal, and a mechanism that prevents the valve body from restarting in the same direction as the drive direction before stopping after the mechanism outputs a stop signal based on the drive load. It has the following characteristics and produces the following effects.

○B In other words, the rotational speed and rotational speed of the drive device are directly extracted as optical pulse signals, and the opening degree of the valve body is calculated by integrating the number of optical pulses.
Since the opening/closing drive load is detected by detecting fluctuations in the pulse period, inconveniences such as errors caused by the presence of mechanically moving parts are eliminated, resulting in high accuracy and excellent reliability. Furthermore, as described above, the means for obtaining the optical pulse signal is used both as a part of the structure for detecting the opening degree of the valve body and as a part of the structure for detecting the drive load of the valve body. The entire device is simpler and more compact than in the past, which required each component separately.

○B In order to obtain the above-mentioned optical pulses, in order to obtain the rotational speed and rotational speed of the rotating member provided in the power transmission system between the drive device and the deceleration mechanism, that is, the rotational speed and rotational speed of the drive device before deceleration. , more optical pulses can be formed and more precise control can be performed. Therefore, the conventional delicate adjustment for setting the opening/closing drive load of the valve element is no longer necessary, and the drive device can be stopped quickly in the event of trouble with simple adjustment.

○C If the mechanism that detects the opening/closing drive load of the valve element detects an overload that exceeds the setting and the drive device stops based on this, the valve element can only be driven again by opening/closing in the opposite direction from before the stop. This feature prevents fatal failures caused by the driver accidentally starting the drive in the same direction (the direction in which overload occurs) when the drive is stopped due to foreign objects getting caught. can.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

As shown in Fig. 1, a valve shaft 3 is attached to a valve body 1 equipped with a flange for connecting a fluid transport pipe, and a valve body 2 is attached to the valve body side seat in a closed state over the entire circumference. The valve shaft 3 can be freely installed and
One end side of the valve body bearing shaft 4 protrudes from the valve body receiving shaft 4, and a drive device 6, an example of which is an electric motor, is interlocked and connected to the shaft end via a planetary gear reduction mechanism 5. As shown in FIG. 2, a device 7 for detecting the opening degree of the valve body 2, a setting device 8 for setting the position of the opening degree of the valve body 2, and a device 7 for detecting the opening degree of the valve body 2. A mechanism 9 is provided which compares the detected value of the opening of the valve body with the value set by the setting device 8 and stops the drive device 6 when the values become the same, and automatically controls the valve body 2 to the set opening of the position. It is configured as a butterfly valve that can do the following.

The valve body opening detection device 7 includes a valve body 2
A plurality of reflecting plates a are attached at intervals in the circumferential direction to the input side rotating member 10 of the planetary gear type reduction mechanism 5 that super-decelerates the A light projector 11 that emits light, and a light receiver 12 that receives light from the projector 11 reflected by the reflection plate a in a pulsed manner as the rotating member 10 rotates, are installed in the deceleration mechanism interior case 5.
A mechanism 13 is provided which calculates and displays the opening degree of the valve body 2 based on the number of light pulses detected by the light receiver 12.

The valve body opening degree calculation and display mechanism 13 calculates the valve body 2 relative to the drive device 6 based on the zero valve body opening degree.
Start adding and measuring the number of received light pulses by opening the
In addition, by the closing operation, subtractive measurement of the number of received light pulses is started, and based on the measured pulse number, the opening degree (θ) of the valve body 2 corresponding to the measured number is digitally displayed. The number of rotations (N) of the rotating member 10 required for 90 degree rotation of the rotating member 10, and the number of pulses (n) per one rotation of the rotating member 10 (in other words, the number of pulses per rotation of the rotating member 10)
quantity), and the number of measurement pulses added and subtracted (P)
Based on this, the valve body opening degree (θ) is configured to digitally display the valve body opening degree (θ) from the formula: Valve body opening degree (θ)=P/N÷90×n.

The position setting device 8 is configured mainly with a microcomputer so that the number of received light pulses (P') is calculated and stored by back calculation based on the opening degree (θ) of the valve body 2. The number of pulses (P') calculated by this setting device 8, that is, the set value, and the number of measured pulses (P), that is, the detected value from the valve body opening degree calculation and display mechanism 13 are inputted into the comparison mechanism 9, respectively, and the values are A control signal is inputted to the control section 6a of the drive device 6 so that the drive device 6 is stopped when the values become the same.

Note that if the drive device 6 stops with a slight time delay after the drive stop signal is sent from the comparison mechanism 9, it is possible to ensure that the comparison values are the same based on the number of pulses required for that time. By predicting the number of pulses, the drive device 6 is activated almost simultaneously with the completion of pulse number detection by the valve body opening degree detection device 7.
can be stopped.

A device 14 for detecting the driving load of the valve body 2, and a mechanism 15 for automatically stopping the valve body driving device 6 when the detected value of the valve driving load exceeds a set value are provided. 2 and the valve box side seat, or the stop control mechanism for the drive device 6 stops working in the fully closed or fully open position. It is possible to prevent this.

The valve body driving load detecting device 14 uses the light emitter 11 and the light receiver 12 of the valve body opening degree detecting device 7 to detect the period of the light reception pulse by these light emitters 11, 12 and the light receiver 12. The mechanism 16 detects the opening/closing driving load of the valve body 2 based on the fluctuation of the pulse period based on the change in the rotational speed of the rotating member 10, and the mechanism 16 detects the variable driving load of the valve body 2 based on the fluctuation of the pulse period based on the change in the rotational speed of the rotating member 10. It is displayed digitally by a computer.

The automatic stop mechanism 15 detects a set value of the valve body driving load after a set time elapses after starting the drive device when opening and closing the valve body, and the valve body driving load detection device 1.
The drive stop signal is sent to the comparison mechanism 9 so as to compare the load detection values from the drive unit 4 and stop the drive of the drive device 6 when the detection value exceeds a set value.
It is configured so that it can be entered.

A check mechanism 17 is provided to prevent the automatic stop mechanism 15 from stopping the driving of the valve body 2 even if a high load greater than a set value is detected within a set time immediately after the drive device 6 is started. With,
Further, an interlock mechanism 18 is installed in the drive device 6 to prevent the automatic stop mechanism 15 from driving the valve body in the same direction as the drive direction before stopping the valve body drive, and to allow the valve body to drive in the opposite direction. It is provided in the operating mechanism 19 for the control section 6a.

FIG. 4 shows a modified structure of the valve body opening detection device 7, in which a light emitter 1 emits light toward the rotating member 10.
A member b is connected to the rotating member 10 so that the light from the light receiver 12 is directly received by the light receiver 12, and the light is intermittently blocked. The latter light is received in a pulsed manner by the light receiver 12, and the light emitter and receiver 11, 12 are used to detect the valve by the valve body drive load detection mechanism 16. A body drive load detection device 14 is configured.

Note that the rotating member 10 may have only one reflecting plate a or one light shielding member b. Furthermore, the present invention can be installed in various valves such as slide valves and ball valves that are opened and closed by the rotary drive device 6.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, with FIG. 1 being a longitudinal sectional front view of the butterfly valve, and FIG. 2 being a sectional view of the drive unit.
FIG. 3 is a block diagram of the control system, and FIG. 4 is an explanatory diagram showing a modified structure of the valve opening detection device. 2...Valve body, 5...Deceleration mechanism, 6...Control unit,
10...Rotating member, 11...Light emitter, 12...Light receiver, 13...Opening degree calculation mechanism, 15...Automatic stop mechanism, 16...Valve body opening/closing drive load detection mechanism, 18
...Interlock mechanism, a...Reflector, b...
Light shielding member.

Claims (1)

[Claims] 1. A drive device 6 that rotates at a constant speed, and a speed reduction mechanism 5 that opens and closes the valve shaft 3 in response to the rotational force of the drive device 6.
and a means for projecting light toward a rotating member 10 provided in a power transmission system between the drive device 6 and the speed reduction mechanism 5, forming an optical pulse signal proportional to the rotational speed of the rotating member 10, and receiving the light. , a mechanism 13 that calculates the opening degree of the valve body 2 by integrating the number of light pulses, a mechanism 16 that detects the opening/closing drive load of the valve body 2 by detecting fluctuations in the pulse cycle, and a mechanism 16 that detects the drive load. a mechanism 15 that outputs a stop signal to the control section 6a of the drive device 6 when the detected value in the mechanism 16 exceeds a setting;
and a mechanism 18 that prevents the valve body from being driven again in the same direction as the drive direction before stopping after the mechanism 15 that outputs a stop signal based on the driving load is activated. Body opening/closing control device.