JPS602037A - Opening and closing state detector of switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to an open/close state detection device for a switch such as a limit switch that detects and displays the open/close state of a switch such as a limit switch using a pulse signal, and is particularly applicable to nuclear power generation facilities. Opening/closing of a switch that is linked to the opening/closing status of multiple valves, etc. installed in a vehicle, etc., and detects and displays the opening/closing status of the valve, etc. The present invention relates to a state detection device.

[Technical background of the invention and other problems] Generally, in nuclear power generation equipment, the reactor containment vessel (hereinafter referred to as I
The reactor pressure vessel, recirculation membrane equipment, and other reactor-subsystem equipment are housed in the F'CVJ (F'CVJ), so that even if a viable substance leaks from the reactor subsystem due to an accident, it will not be destroyed. It is designed to prevent it from spreading outside. Various valves are provided within the PCV.

A conventional open/close state detection device for detecting and displaying the open/close state of a valve installed under such conditions is known, for example, as shown in FIG.

In FIG. 1, reference numeral 1 indicates n valves installed in the PCV, each valve 1-1, 1-2, . . . 1-n.
are provided with movable parts 2-1, 2-2, . When the movable part 2 protrudes, the limit switch 3
-1.3. -2, . . . 3-n movable parts are pressed to close the contacts of each limit switch 3. Each limit switch 3 is connected to a signal cable l-1, 4-2...4-n.
and 5-1, 5-2...5-n are connected, and a closed circuit is formed by closing the contacts of each limit switch 3.

Here, the signal cables 4 and 5 have a radioactive material shielding number (q
Connector 6- inserted into plate (penetration) 7
1.6-2...6-n, and the signal cable 5 has an ammeter 8-1.8-2...F3.
-n and DC power supplies 9-1.9-2.9...n are connected in series, respectively. Therefore, when the limit switch 3 is turned on, a current flows from the DC current 9 to the cables 4 and 5 and the hook of the ammeter 8 is touched, so that the open state of the valve 1 can be detected.

However, this type of device requires as many electrical circuits as the number of valves, and therefore as many connectors 6 as there are valves 1. On the other hand, since the number of valves ranges from several tens to several 1000, there is a drawback that connector installation work and cable connection work are complicated.

Therefore, there has been a demand for an open/close state detection device that covers as few connectors 6 as possible.

Therefore, the applicant proposed an open/close state detection device as shown in FIG. That is, valves 1-1.1-2,...1
A cable 4-n is connected to a movable part 2-1, 2-2, .
1.4-2°...4-n tip 3-1.3-2,.
3-n is installed nearby, and its tip 3 is configured with a switch such as a limit switch, and the cable 4 is connected by the movement of the movable part 2.
Make sure that the tip load is open and short. A plurality of signal tuples 4 corresponding to each valve 1 and one connector 6-1 inserted through the mounting plate 7 are connected by a branching portion 10 for branching the tuples. On the other hand, at the other end of the connector 6-1, there is a pulse oscillator 11 that applies pulses to the cable 4, and an echo (!
A signal processing section 12 that detects the positive and negative polarities of the reflected waves (2 reflected waves) and echo pulse time to determine whether each valve 1 is open or not is connected to a display device 13 that displays the results of the signal processing section 12.

The most important point in the opening/closing state detection device constructed in this way is to use cables of different lengths from the branch section 10 to the valve 1.

Next, the operation of this device will be explained. First, the pulse oscillator 11
Apply narrow pulses to the cable from
This pulse is transmitted via branch 10 to each valve 1-1.1-
2,...1-n, each tip 3-1.3-2,...
...3-n foul. At this time, the tip section 3 is opened when the valve 1 is open, and the tip section 3 is shorted when the valve 1 is open. , for a positive applied pulse, a positive pulse is obtained when valve 1 is open, while a positive pulse is obtained when valve 1 is open. Also, since the lengths of the cables/l-11-2,...4-n are all different, the time it takes for the applied pulse to propagate through the cable and return (i.e. one hour of eco-time) depends on the length of each cable. Correspondingly different. The echo palaces thus obtained are individually selected, and the polarity and time of each pulse are detected and measured to determine whether each valve 1-1.1-2, . . . 1-n is open or not. The results are displayed on the display device 13 in various forms.

In this device, the eco time is changed depending on the length of the cables 4-1.4-2,...4-n, and each valve 1-1.1-2
, . . . 1-n are separated to detect the open/closed state of the valve 1.

On the other hand, as a method of separating echoes, each cable 4-1, 4-2, .
For example, delay circuits having different delay times using delay lines or the like may be inserted in n.

However, as the number of valves increases, the level of echo pulses decreases, waveform distortions, disturbances, etc. may cause the echoes to overlap, leading to possible malfunctions, resulting in reliability problems.

[Objective of the Invention 1] The present defense has been made in view of the above-mentioned points, and it is possible to reduce the number of cables and connectors for connecting cables, reduce malfunctions, have high reliability, and be able to withstand high temperatures, high humidity, It is an object of the present invention to provide an open/close state detection device for a switch that is suitable even under environments such as high radiation.

[Summary of the Invention] In order to achieve this object, the present invention provides a delay element to avoid delaying the echo by making a plurality of cables long and short or providing a delay circuit, and also provides a pulse width limiting circuit for echo pulses to transmit pulses. The pulse width limiting circuit separates the echoes of pulses applied to multiple cables by the machine, the signal processing section detects and measures the polarity and time of the echoes, and the results are displayed on the display device. This is an open/close state detection device for an on-off valve, characterized by:

Embodiment of the Invention] An embodiment of the invention will now be described with reference to FIGS. 3 and 4.

FIG. 3 is a block diagram showing the configuration of the opening/closing state detection device, and the same elements as in FIG. 2 are given the same reference numerals.

This device differs from the device shown in FIG. 2 in that a pulse width limiting circuit 20 is inserted into the connector 6 and the signal processing section 12, and a delay element is provided in the cable 4.

That is, in this switch open/close state detection device, each valve 1-1
．． Tip portion 3-1.3- corresponding to 1-2,...1-n
2,...3-n and branch cable 4-1.4-2,
. . 4-n is provided with delay circuits 26.26-1 to 26-n and connected to one end of the connector 6 via the branch portion 10. The connector 6 is fixed to a slot plate 7, and an electric signal cable 27 led out from the connector 6 is provided with a pulse oscillator 11, a pulse width limiting circuit 20, a signal processing section 12, and a display device 13. Here, the pulse width limiting circuit 20 outputs only a predetermined portion of the input waveform, and for example, a sampling circuit or the like is used.

The signal processing unit 12 also includes a polarity detection circuit 21 that detects the positive and negative polarities of the echo pulses, an eco-hour measuring circuit 22 that measures the echo pulse, and a polarity detection circuit 22 that measures the echo pulse and the echo pulse. Cable tip 3-1, 3-2,...
It is constituted by an open/close state determination circuit 23 that determines whether each switch installed at 3-n is an open loop or a closed loop, that is, whether each valve 1-1, 1-2, . . . 1-11 is open or open. Each of these circuits 20.21.22.23 and the pulse oscillator 11
is a control circuit 2 having a memory function, a dripping function, a control function, etc.
4 according to a predetermined program.

Data and the like are input to the control circuit 24 via the console 25. An example of the operation of the opening/closing state detection device configured as described above will be explained with reference to FIGS. 3 and 4.

First, a pulse (A) is applied from the pulse oscillator 11 to the electric signal cable 27 based on a control command signal from the control circuit 24 . The pulse (A) is connected to branch couples 4-1, 4-2, . . . corresponding to each valve 1 at the branch section 10.
Branched into 4-n, each valve 1-1.1-2,...1-n
and is reflected by the tip portions 3-1, 3-2, . . . 3-n.

In this case, as explained in FIG. 2 above, a positive echo pulse is obtained when the valve 1 is in the middle (that is, when the tip 3 is open), and on the other hand, when the valve 1 is closed, that is, the tip 3 is short-circuited. ) a negative pulse is obtained. In Fig. 3, valves 1-1, 1-2, ... 1-n are open, so positive echo pulses (b), (c), ... (force) are obtained (Fig. 4 a). reference).

Here, signal cables 4-1, 4-2,...
- Make the lengths of 4-n different, or insert delay circuits 26.26-1 to 26-n. However, as the cable becomes longer, the fall time of the echo pulse becomes longer and the pulse width tends to become wider. Also, the tip 3-
1.Echo reflected by 3-2,...3-n (b), (
(c), ... (force) is partially reflected by the branch part 10 and the connector taro, etc., and reflected again by the tip part 3 (b), (c), ... (force) and a little bit on the time axis It is possible that they may shift and overlap. Therefore, when the echo pulse 3 propagates through the cable 4 and returns, it cannot be completely separated as shown in FIG. 4(a). There are also cases where the waveform is significantly distorted.

However, the position of the echo pulse on the time axis is determined by the C law according to the length of the signal cables 4-1, 4-2, . . . 4-n. If you cut out just that part, you can detect the echo polarity.

Therefore, the pulse width limiting circuit 2o inputs the echo pulse train (a) that propagated through the cable 4 and returned, and receives the sampling pulse ( b) and output only the necessary echo pulse (c) using an AND gate or the like.

The pulse train of the separated echoes thus obtained is sent to the polarity detection circuit 21 of the signal processing section 12 and the echo 11. ¥11
11 measurement circuit 22, these circuits 21.22
The polarity and time are detected and measured, and the results are transmitted to the open/close state determination circuit 23. Then, the open/close state determination circuit 23 determines the open/close state of each valve 1-1, 1-2, .

In this embodiment, the pulse width limiting circuit 20 is used to reliably separate the echo pulses into pulse arrays, and the polarity of these echoes is measured to detect the open/closed state of the valve 1, and a plurality of pulse Σ identifications are performed. Since the system employs a determination method using the eco-time difference, the number of cables and connectors can be minimized, and the open/closed status of the valve can be accurately detected and displayed.

In the above embodiment, an example in which the echo is delayed due to the difference in cable length was mainly explained, but each cable 4-1, 4-2, . . . Delay circuit 26.26-1 to 26- that gives a certain delay to the signal
It goes without saying that the same effect can be achieved by inserting n.

Further, in the above embodiment, an example was explained in which the open/closed state of the valve 1, which is the detected part, is detected and displayed, but the present invention can also be applied to other detected objects other than valves.

[Effects of the Invention] As explained above, according to the open/closed state detection device for a switch according to the present invention, the echo polarity detection and processing can be performed by limiting the pulse width and separating the echoes into tilts before performing the one-hour measurement. I try to do that. Therefore, the open/closed state of the switch can be accurately detected and displayed with a minimum number of signal cables and connectors.

In addition, since there is a device that samples only the necessary portions of ``-'', it can sufficiently cope with cases where the number of valves, etc. increases, the overall echo level drops by 411, or the waveform is greatly distorted. Furthermore, the open/closed states of multiple valves, etc. are not displayed incorrectly, and system checks are extremely easy, eliminating the need for specialized equipment.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a conventional open/close state detection device for a switch, Fig. 2 is a block diagram showing a prior art switch open/close state detection device, and Fig. 3 is a block diagram showing an embodiment of the present invention. FIG. 4 is a block diagram of the opening/closing state detection device for the breaker, and is a waveform diagram showing pulses at various parts of the circuit shown in FIG. 3. 1, 1-1, 1-2, 1-3, 1-4,...1-
rl...Valve 2.2-1.2-2.2-3.2-4,...2-n.
...Valve movable part 3.3-1.3-2.3-3.3-4, ...3-n,
... Cable tip 4.4-1.4-2.4-3.4-4, ...4-n.
...Signal cable, 6.6-1.6-2.6-3, ...6-nl...Connector, 10...Branch section 11...Pulse oscillator 12...Signal processing section 13・
...Display section 20...Pulse width limiting circuit 26.26-
1.2G-2, 26-3, 26-4...26-n...
・Delay circuit application agent Patent attorney Gobe Kikuchi

Claims (1)

[Claims] (1) A connector that provides multiple branch cables with a switch that can be electrically turned on and off at the tip, a pulse oscillator that applies electrical pulses to the electrical signal cable of this connector, and a pulse oscillator that applies electrical pulses to the electrical signal cable of this connector. A pulse width limiting circuit that shapes the echo waveform of the applied pulse reflected from the tip of the branch cable and returned, and detects and measures the polarity and time of this shaped echo to determine the on/off state of the switch. An open/closed state detection device for a switch, comprising: a signal processing unit that outputs a signal, a display device that displays a determination result of the signal processing unit, and a delay element that delays the echo in the plurality of branch cables.