JPH09159047A - Switch drive device for valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To not only adequately exhibit aperture adjustment function in relation to operation inferiority such as sticking and operation impossibility in normal operation but quickly detect abnormal operation such as control trouble so as to urgently stop. SOLUTION: An aperture position signal S1 from an aperture sensor 13 which detects an aperture position of a valve body opened/closed by a hydraulic cylinder 11 and an aperture instruction signal S2 input from the outside are differentiated respectively so that the change directions of the valve body aperture and the aperture instruction signal are detected respectively. This device is provided with a direction detection means 19 which outputs a stop signal S5 to the hydraulic cylinder 11, when signs (+, -) of the both change direction detection signals are checked and the both signs are not accorded with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve opening / closing drive device,
Specifically, it is used for controlling the flow rate of high temperature catalysts such as plug valves and slide valves, and the opening of the fluid passage inside the valve body can be adjusted by linear movement and sliding movement of the valve body, The present invention relates to a valve opening / closing drive device configured to open / close.

[0002]

2. Description of the Related Art As a valve opening / closing driving device of this type, a device having a structure shown in FIG. 4 has been generally used. In FIG. 4, reference numeral 10 denotes a valve such as a plug valve or a slide valve, and a hydraulic pressure as an opening / closing drive device for a valve body (not shown) that opens and closes an internal fluid passage (not shown) in the valve body of the valve 10. A movable rod 12 of a fluid pressure cylinder 11 such as a cylinder is connected. The fluid pressure cylinder 11 has an opening sensor 1 for detecting the opening position of the valve body.
3 is additionally provided, and an opening position signal S1 from the opening sensor 13 and an opening command signal S2 that is externally input.
Is provided to detect the deviation between the signals S1 and S2, and the servo valve 15 is operated based on the control signal S3 corresponding to the deviation output from the servo amplifier 14. Through this, the operation of the fluid pressure cylinder 11 is automatically controlled to adjust the opening degree of the valve element to the command opening degree.

Further, an opening position signal S1 from the opening sensor 13 and an opening command signal S2 that is externally input are input, and the deviation between these signals S1 and S2 is set to a set value (about 2%). ) And a predetermined time (several seconds to several tens of seconds, which is about 20% increase of the fully open and fully closed time), is provided with a detector 16, and when the detector 16 is activated, a stick or the like is provided. It is configured to perform the fail-safe operation such as determining that there is a malfunction or inoperability of the alarm signal S4, outputting the alarm signal S4, and stopping the input of the opening degree instruction signal S2 based on the alarm signal S4. There is.

[0004]

In the conventional valve opening / closing drive configured as described above, a proper opening adjusting function is exhibited even when malfunctions or inoperability of sticks and the like occur. However, if an abnormal operation occurs due to a control trouble, such as the valve element operating in the opposite direction against the opening command signal, it may be an operation delay during normal operation, that is, whether the stick or the like is malfunctioning or inoperable. Because it takes time to find out (several seconds to 10 seconds),
The response was inevitably delayed, and during that time, the opening of the valve element advanced and became fully open or fully closed, which promoted troubles and the valve opening went out of control.

Therefore, the present invention has been made in view of the above circumstances, and it is of course possible to exert a proper opening adjustment function against occurrence of malfunction or inoperability of a stick or the like during normal operation, as well as control trouble. It is an object of the present invention to provide a valve opening / closing drive device capable of quickly detecting an abnormal operation such as and performing an emergency stop.

[0006]

In order to achieve the above object, a valve opening / closing drive device according to the present invention detects a valve body for opening and closing an internal fluid passage of a valve body and an opening position of the valve body. An opening sensor that detects a deviation between the opening position signal and the opening command signal by the opening sensor, and automatically controls the opening of the valve body based on a control signal corresponding to the deviation. In a valve opening / closing drive device comprising an automatic control device, a means for differentiating the opening position signal by the opening sensor to detect the changing direction of the valve opening, and a differentiation of the opening command signal. It is characterized by comprising means for detecting the changing direction of the command signal, and means for checking the signs of both the changing direction detection signals and outputting a stop signal when the signs do not match. Yes, during normal operation, the opening position by the opening sensor The deviation between the signal and the opening command signal input from the outside is detected, and the opening of the valve element is automatically controlled based on the control signal corresponding to the deviation, for example, a malfunction of the stick or the like can be disabled. On the other hand, while always performing the appropriate opening adjustment function, the two signals are always differentiated to detect their changing directions.In this state, for example, the valve body moves in the opposite direction against the opening command signal. If an abnormal operation occurs due to control trouble such as operation, the stop adjustment signal is output promptly by checking the sign of both change direction detection signals, and the opening adjustment operation is urgent so as not to expand the trouble. It is possible to stop.

Here, as a control signal for automatically controlling the opening degree of the valve body, a servo current to a servo valve for controlling the operation of the fluid pressure type drive device is used. Further, it is desirable to activate an alarm such as a buzzer in parallel with the output of the stop signal.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of a valve opening / closing drive device according to the present invention.
Since 1, S2 and S3 have the same configuration as the conventional example shown in FIG. 4, the same reference numerals are given and detailed description thereof is omitted.

In FIG. 1, 17 and 18 are differentiating circuits,
One of the differentiating circuits 17 is means for differentiating the opening position signal S1 from the opening sensor 13 to detect the direction of change of the valve opening, and the other differentiating circuit 18 is an opening command input from the outside. The signal S2 is differentiated and its opening command signal S2
And a means for detecting the direction of change of the respective. 1
Reference numeral 9 denotes a direction determination circuit, which checks the signs (+,-) of the both changing direction detection signals and outputs a stop signal S5 to the servo valve 15 when the signs (+,-) do not match. When the stop signal S5 is output, the operation of the hydraulic cylinder 11 as the fluid pressure cylinder is stopped urgently.

FIG. 2 shows a sectional structure of a slide valve applied as an example of the valve 10. Reference numeral 1 denotes a valve main body, which has a fluid passage 1A for a catalyst or the like, and a fluid pipe 2 It is connected. Reference numeral 3 denotes a slide valve body, and the slide valve body 3 is provided on the valve body 1 so as to face the step portions 1B and 1B formed on both sides of the fluid passage 1A inside the valve body 1 and the step portions 1B and 1B. It is slidably guided by the fixed guides 4 and 4 and supported so as to be slidable in a direction traversing the fluid passage 1A. The sliding movement adjusts the opening of the fluid passage 1A, and , Is configured to open and close. One end of the slide valve body 3 is connected to the movable rod 12 of the hydraulic cylinder 11.

In the opening / closing drive device for the slide valve 10 configured as described above, normally, the opening command signal S2 input from the outside and the current opening position signal S1 detected by the opening sensor 13 are provided. A deviation is detected by the servo amplifier 14, and a control signal S corresponding to the detected deviation is detected.
3 through the servo valve 15 based on the hydraulic cylinder 1
The operation of No. 1 is automatically controlled to adjust the opening of the slide valve body 3 to the command opening, and a predetermined flow rate control is performed.

Even in such a normal flow rate control operation, the two signals S1 and S2 are always differentiated by the differentiating circuits 17 and 18, respectively, and the changing directions of the valve opening and the opening command signal S2 are changed. Is detected, and the signs (+, −) of the both change direction detection signals are checked by the direction determination circuit 19, and the slide valve body 3 operates in the opposite direction against the opening command signal S2, for example. When a control trouble such as the above occurs, the signs (+, −) of the both change direction detection signals become inconsistent, and the stop signal S5 is immediately output from the direction determination circuit 19, which causes the servo valve 15 to operate. The opening degree adjusting operation of the valve body 3 by the hydraulic cylinder 11 is urgently stopped via the, so that the trouble can be prevented from spreading.

In the above embodiment, the slide valve 1
However, other than this, for example, as shown in FIG. 3, a fluid in which a cone-shaped seat portion 5a for sucking the high temperature catalyst b with the ejection of lift air a is formed at the tip is formed. Pipe 5 (valve body) and hydraulic cylinder 11
Is fixed to the tip of the stem tube 6 which is linearly reciprocally driven along the axial direction of the fluid pipe 5 via
The plug 7 (valve body) that moves in and out of the cone-shaped seat portion 5a by the linear movement to open and close the flow path 5A in the fluid pipe 5
Even if it is applied to a plug valve composed of, the same effects as above can be obtained.

Further, as indicated by the phantom line in FIG. 1, by causing the alarm device 8 such as a buzzer to operate in parallel with the output of the stop signal S5 from the direction determination circuit 19, the occurrence of trouble is prevented. Can be notified.

[0015]

As described above, according to the present invention, during normal operation, the valve is operated based on the control signal corresponding to the deviation between the opening position signal from the opening sensor and the opening command signal input from the outside. Although it is possible to automatically control the opening of the body and perform an accurate opening adjustment function even for malfunctions and inoperability of, for example, sticks, for example, the valve body does not respond to the opening command signal. If an abnormal operation occurs due to control trouble, such as operating in the opposite direction, it is possible to quickly detect the abnormal operation and perform an emergency stop.
It is possible to prevent the trouble from spreading and the runaway caused by the abnormal operation continuing for a long time, and to improve the safety.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a valve opening / closing drive device according to the present invention.

FIG. 2 is a vertical sectional view showing a specific structure of a slide valve to which the present invention is applied.

FIG. 3 is a vertical cross-sectional view of a main part showing a specific structure of a plug valve to which the present invention can be applied.

FIG. 4 is an overall configuration diagram of a conventional valve opening / closing drive device.

[Explanation of symbols]

 1 valve body 1A fluid passage 3 valve body 10 valve 11 hydraulic cylinder 13 opening sensor 17, 18 differentiating circuit 19 direction determining circuit S1 opening position signal S2 opening command signal S3 control signal S5 stop signal

Claims (1)

[Claims] 1. A valve body for opening and closing an internal fluid passage of a valve body, an opening sensor for detecting an opening position of the valve body, and a deviation between an opening position signal and an opening command signal by the opening sensor. And an opening and closing drive device for automatically controlling the opening degree of the valve element based on a control signal corresponding to the deviation, A means for differentiating the signal to detect the changing direction of the valve opening, a means for differentiating the opening command signal to detect the changing direction of the command signal, and the signs of both changing direction detection signals are checked. And a means for outputting a stop signal when the two signs do not match, the valve opening / closing drive device.