JP2008282066A - Failure prediction relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a failure prediction relay capable of predicting failures using simple configuration that uses hardware relay and timers. <P>SOLUTION: The failure prediction relay 3 is constituted of a holding relay 4, a failure prediction timer 5, a failure detection timer 6, and a signal relay 7. The hold relay 4 is actuated by a pump operation instruction 1a, and the failure prediction timer 5 and the failure detection timer 6 start counting. The signal relay 7 is actuated by a water passage detection signal 2a, and water passage detection is carried out. When the water passage detection signal 2a is not inputted, even after a lapse of a first time-up period causing a trouble in continuity of process operation, a failure detection signal is outputted by the failure detection timer 6. When the water passage detection signal 2a is not inputted, even after a lapse of a second time-up period shorter than the first time-up period, a failure prediction signal is outputted by the failure prediction timer 5. As a result of this, failure prediction can be carried out by the simple structure using the hardware relay and the timers. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a failure notification relay for providing failure notification of individual processes in a plant.

  Generally, a plant stops the plant when a failure occurs that hinders operation. Therefore, there is a problem that the plant cannot be operated until the failure is recovered.

  If you can see the signs of a failure, you can deal with it and continue to operate the plant before it breaks down.

  Normally, people visit the plant during inspections, and care is taken to ensure that safe driving is not hindered, such as visual confirmation and abnormal noise.

  However, in general, it is difficult to detect machine / equipment with a slow deterioration rate, clogged pipes, or sensor deterioration, and the more the deterioration progresses, the slower the reaction speed of the process, eventually causing a failure. The event could not be grasped until all the way, so it was not possible to respond in advance.

  Therefore, conventionally, for example, in a control panel (PLC) 20 of a plant monitoring / control system comprising a monitoring / control device 10, a control panel (PLC) 20, a relay panel 30, and a water flow process 40 as shown in FIG. It is considered to perform failure detection and failure notice by controlling the water flow process 40 and monitoring the time from when the operation command is output until the water flow detection signal is detected. .

On the other hand, in a remote monitoring and control device composed of a control station and a controlled station, the control response time of the device is measured, and compared with a reference response time set in advance, an output is generated when the value is equal to or greater than a predetermined value. There is known a control diagnostic apparatus that can know a failure of a controlled device in advance by generating a failure notice signal when the values are accumulated and exceed a predetermined value (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 3-163955

  However, the detection of the failure warning signal by the remote monitoring control device as in Patent Document 1 cannot be detected unless the remote monitoring control device is operating normally.

  Even in the plant, the control device provided for controlling the plant, that is, the control panel (PLC) 20 of FIG. 5 can have the same function in software as described above. ) Failure notice signal cannot be detected unless 20 is operating normally. Further, when the control panel (PLC) 20 is stopped and the plant is operated with a limited range, there is a problem that a failure warning signal cannot be detected.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a failure notification relay capable of performing failure notification with a simple configuration using a hard relay and a timer.

  In order to achieve the above object, a failure warning relay according to the present invention is provided in each process of a plant, operates in response to a process operation start signal, and resets with a process operation completion signal. A relay, a second relay that outputs a signal indicating a normal state upon receipt of a completion signal, and a time from receipt of the start signal to receipt of the completion signal exceeds a predetermined first time-up time A failure detection timer for outputting a failure detection signal, and a time from receiving a start signal to receiving a completion signal exceeds a predetermined second time-up time shorter than the first time-up time, A failure notification timer for outputting a failure notification signal is provided.

  According to the present invention, even if the control device provided for controlling the plant is stopped, failure notification can be performed with a simple configuration using a hard relay and a timer without increasing the installation space and wiring. It can provide a failure warning relay with high reliability and versatility.

  Hereinafter, a failure notification relay according to an embodiment of the present invention will be described in detail with reference to the drawings. In the following drawings, the same symbols indicate the same or corresponding parts.

  FIG. 1 is a diagram showing a circuit configuration of a failure notification relay according to an embodiment of the present invention, FIG. 2 is a flowchart showing its operation, and FIG. 3 is an external view of the failure notification relay according to an embodiment of the present invention. FIG. 4 is a diagram showing an example of a plant monitoring and control system to which a failure notification relay according to an embodiment of the present invention is applied.

  As shown in FIG. 1, the pump 1 is operated by a pump operation command 1a. This operation command 1 a and a water flow detection signal 2 a generated at the contact 2 a of the water flow sensor 2 that detects that water has flowed after the pump operation is input to the failure notification relay 3. The failure warning relay 3 includes a holding relay 4 that self-holds at the contact 4a until a water flow is detected when the pump operation command 1a is input, and a time-up time that is shorter than a time that hinders operation continuation. A failure warning timer 5 set on the basis of the measured value at the time, and an external output contact 5a for notifying that some abnormality is occurring in a part of the plant when the time is up are provided. Moreover, the failure detection timer 6 set to the time when time-up time has trouble in driving | running continuation, and the external output contact 6a for notifying that there is trouble in driving continuation when time-up is provided. If the water flow process is normal and the time when water flow is detected after the pump operation is about 10 seconds at the maximum, for example, the time-up time of the failure warning timer 5 is about 15 seconds. The time-up time of the detection timer 6 is about 20 seconds.

  Furthermore, after the pump operation, the signal relay 7 that operates by water flow, the external output signal contact 7a for notifying that the process is in a normal state, the release of the holding relay 4, the failure warning timer 5 and the failure detection timer A contact 7b for stopping the count of 6 is provided.

  Next, the operation of this embodiment will be described with reference to FIG.

  When the pump is operated according to the pump operation command 1a (step S31), a process operation start signal based on the pump operation command 1a is input to the failure warning relay 3, and the holding relay 4 is operated (step S32), and is self-held by the contact 4a. . At the same time, the failure notice timer 5 and the failure detection timer 6 start counting (steps S33 and S34). Next, it is determined whether or not a water flow detection signal 2a, which is a process operation completion signal generated by pump operation, is input (step S35). If the failure warning timer 5 is counted up (timed up) before the water flow detection signal 2a is input (step S36), the external output contact 5a is turned on to output a failure warning signal and some abnormality in the process. A failure notice is made to inform the outside that this is happening (step S37). Furthermore, when the water flow detection signal 2a is not input even after a predetermined time has elapsed, the failure detection timer 6 counts up (time up) (step S38), the external output contact 6a is turned on and a failure detection signal is output. Then, a failure output is made to notify the outside that there is an obstacle to the operation of the plant (step S39). If the water flow detection signal 2a is input before the failure warning timer 5 or the failure detection timer 6 counts up (time up), the signal relay 7 operates (step S40), the external output contact 7a is turned on, A water detection signal is output to detect that the process is in a normal state (S41). At the same time, the contact 7b is turned off, the holding relay 4 is released, and the failure notice timer 5 and the failure detection timer 6 are stopped.

  Thus, it is possible to provide a failure notification relay that can be used not only for detection of a failure notification signal but also for normal failure detection and normal operation detection.

  Next, the configuration of this embodiment will be described with reference to FIG.

  As shown in FIG. 3 (a), the failure notification relay 3 includes a holding relay 4, a failure notification timer 5, a failure detection timer 6, and a signal relay 7 housed in a single unit in a multi-stage configuration. A circuit is configured. A terminal block 8 is combined for external connection of this unit. The time-up time of the failure warning timer 5 and the failure detection timer 6 is set by a digital switch provided on the front panel 9. FIG. 3B is an enlarged view of the front panel 9. With such a configuration, the number of contact points of the relays and timers to be used is limited, so that even if they are housed in one unit, a large space is not required and they can be compactly assembled. Even if a plurality of these are used and stored in the board, they can be arranged without expanding the mounting space and wiring. In addition, timer setting (time-up time setting) can be performed from the front, so confirmation and maintenance can be easily performed.

  FIG. 4 shows an example of a plant monitoring and control system to which a failure notification relay according to an embodiment of the present invention is applied. In FIG. 4, 10 is a monitoring / control device, 20 is a control panel (PLC), 30 is a relay panel to which a failure warning relay 3 is attached, and 40 is a water flow process.

  In this embodiment, the control of the water flow process 40 in the control panel (PLC) 20 of the plant monitoring / control system is the same as in the prior art. Failure detection and failure notification that have been performed are performed by the failure notification relay 3. As described above, failure detection and failure notification are performed by hardware having a simple configuration using a hardware relay or a timer in the failure notification relay 3, so when these are performed on the control panel (PLC) 20 by software. Compared to that, it is much more reliable. Moreover, even when the control panel (PLC) 20 is stopped, it is possible to detect a failure or notify a failure.

  As described above, according to this embodiment, not only normal failure detection and normal operation detection, but also the wear of slow-down machines / equipment in individual processes of the plant, the clogging of piping, or the deterioration of sensor accuracy are detected. In addition, it can be grasped by the failure warning timer in which the time-up time is set on the basis of the planned value or the measured value at the time of trial operation, and can be dealt with before the failure of the process.

  In addition, since the number of contact points of relays and timers used is limited, it does not require a large space even if it is housed in a single unit, and it can be compactly packed. Can be placed without increasing.

  In addition, since fault detection and fault warning that were conventionally performed in software are performed by hardware using hardware relays and timers, fault detection and fault notification are performed more than when software is used in the control panel (PLC). The reliability of doing can be improved. Furthermore, even when the control panel (PLC) fails or when the control panel (PLC) is stopped, it is possible to detect a failure or notify a failure.

  Conventionally, failure detection and failure warning are performed by software on the control panel (PLC). Therefore, the timer setting / change of failure detection and failure warning is performed by a command from the monitoring / control device, or the control panel ( Although it was necessary to connect a tool for setting / changing the timer to the PLC), according to the present embodiment, the digital switch provided on the front panel of the failure warning timer for each process of each machine It can be done easily.

The figure which shows the circuit structure of the failure notification relay concerning one Embodiment of this invention. The flowchart which shows operation | movement of one Embodiment of this invention. The figure which shows the external appearance of the failure notification relay concerning one Embodiment of this invention. The figure which shows the example of the monitoring and control system of the plant to which the failure warning relay concerning one Embodiment of this invention is applied. The figure which shows the example of the monitoring and control system of the conventional plant.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pump 1a ... Pump operation command 2 ... Water flow sensor 2a ... Water flow detection signal 3 ... Failure warning relay 4 ... Holding relay 4a ... Holding relay a contact 5 ... Failure warning timer 5a ... Failure warning timer a contact 6 ... Failure detection Timer 6a ... Fault timer a contact 7 ... Signal relay 7a ... Signal relay a contact 7b ... Signal relay b contact 8 ... Connection terminal block 9 ... Timer setting panel 10 ... Monitoring / control device 20 ... Control panel (PLC)
30 ... Relay panel 40 ... Water flow process

Claims (2)

  A first relay that is provided in each individual process of the plant, operates in response to a process operation start signal, and resets in response to a process operation completion signal; and a signal that indicates a normal state in response to the completion signal A failure detection timer that outputs a failure detection signal when a time from receiving the start signal to receiving the completion signal exceeds a predetermined first time-up time; A failure warning timer for outputting a failure warning signal when a time from receiving the start signal to receiving the completion signal exceeds a predetermined second time-up time shorter than the first time-up time; A failure warning relay characterized by comprising.   The failure notification relay according to claim 1, wherein the first relay, the second relay, the failure detection timer, and the failure notification timer are housed in one unit.

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