JPS6025677B2 - Valve abnormality detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a valve abnormality detection device for detecting abnormalities in electromagnetic valves.

In press machines and the like, safety is improved by connecting a pair of electromagnetic valves in series to control a brake and a clutch.

Recently, the operation of these electromagnetic valves is also monitored, and if an abnormality occurs, the entire operation is stopped in an effort to improve safety.

However, conventional valve abnormality detection devices measure and monitor the time from when one solenoid valve completes its operation until the other solenoid valve completes its operation. There was a drawback that abnormalities could not be monitored until the operation of the valve body was completed.

Further, although conventional devices can detect the presence or absence of an abnormality, they have the disadvantage that they cannot determine which electromagnetic valve has an abnormality. Furthermore, although conventional devices detect abnormalities in electromagnetic valves, they have a drawback in that they cannot detect abnormalities in output relays.

The present invention has been developed with these points in mind, and has the ability to reliably detect abnormally delayed operation of electromagnetic valves and to be used safely for controlling brakes and clutches of press machines, etc. The purpose of the present invention is to provide a valve abnormality detection device capable of determining which of individual electromagnetic valves has an abnormality, and further,
The object of the present invention is to provide a valve abnormality detection device that can also detect abnormalities in output relays. To this end, the present invention provides a valve abnormality detection device including an operation detection switch that outputs a detection signal when the valve body of an electromagnetic valve operates, and an operation detection switch that outputs a detection signal after an excitation current starts flowing through the excitation coil of the electromagnetic valve. a valve abnormality determination circuit that detects the time from when the excitation current ends to when the operation detection switch ends to output the detection signal and outputs a valve abnormality signal when the time exceeds a predetermined time; By configuring it like this,
Abnormal delays in the operation of electromagnetic valves can be reliably detected by the presence or absence of a valve abnormality signal generated by the valve abnormality detection circuit described above, and the valve abnormality detection circuit can be safely used for controlling the brakes and clutches of press machines. This realizes a detection device.

The present invention further provides first to nth operation detection switches that output detection signals when the valve bodies of the first to nth electromagnetic valves operate, and each excitation coil of the first to nth electromagnetic valves. Detect each time from when the excitation current begins to flow until each of the operation detection switches begins to issue a detection signal, or after the excitation current stops flowing until each of the operation detection switches finishes outputting a detection signal. first to n-th valve abnormality determination circuits each outputting a valve abnormality signal when the period exceeds a predetermined time; By configuring a valve abnormality detection device with the first to n-th abnormality determination means that perform abnormality determination operation based on the valve abnormality signal, the abnormality of each electromagnetic valve is determined by the valve abnormality signal generated by each valve abnormality determination circuit. It can reliably detect delayed operations and can be safely used to control the brakes and clutches of press machines.
It is possible to determine which of the electromagnetic valves has an abnormality by the action of each abnormality determining means provided corresponding to each valve abnormality determining circuit.

Furthermore, the present invention provides a valve abnormality detection device for detecting valve abnormalities.
The first to nth operation detection switches each output a detection signal when the valve body of the electromagnetic valve operates, and each operation is detected after an excitation current starts flowing through each excitation coil of the first to nth electromagnetic valve. Each time is detected until the switch begins to issue a detection signal, or after the excitation current stops flowing until each of the operation detection switches finishes issuing a detection signal, and when each time exceeds a predetermined time, each valve is abnormal. first to nth valve abnormality determination circuits that output signals, and first to nth valve abnormality determination circuits that are provided correspondingly to the first to nth valve abnormality determination circuits and are driven by valve abnormality signals from the corresponding circuits. An n-th output switch, an output relay driven by the on/off of each of the output switches, and an output relay that detects the operating state of each of the output switches, and detects a deviation in the operating state of any of the output switches for a predetermined period of time. and an output relay abnormality determination circuit which outputs an output IJ relay abnormality signal when the output IJ relay is exceeded, thereby ensuring detection of abnormal delayed operation of each electromagnetic valve by the valve abnormality signal generated by each valve abnormality determination circuit. The output relay abnormality determination circuit detects the operating status of each output switch driven by the valve abnormality signal from each valve abnormality determination circuit. It is also possible to detect an abnormality in the output relay using the output relay abnormality signal.

Hereinafter, a detailed description will be given with reference to embodiments shown in the drawings.

FIG. 1 shows an example in which the present invention is applied to a dual valve in which a first electromagnetic valve 1 and a second electromagnetic valve 2 are connected in series. These first and second electromagnetic valves 2 are connected to valve bodies 3 and 4, and these valve bodies 3 and 2 are connected to valve bodies 3 and 4.
, 4, and first and second operation detection switches 7 that detect the operating state of each valve body 3, 4. The operation detection switches 7 and 8 may be any type of switch, such as a proximity switch or a limit switch, as long as it outputs an electric signal when the valve bodies 3 and 4 operate. FIG. 2 shows an example of an abnormality detection device for the dual valve shown in FIG. 1.

The first and second electromagnetic solenoids 5 and 6 have their excitation coils 5
When an alternating current excitation current flows through A and 6A, this excitation current is converted to direct current by AC-DC conversion circuits 9 and 10, and the respective DC outputs are passed through the first and second valves formed by exclusive OR circuits. It is applied to the abnormality detection circuits 11 and 12. Detection signals are also applied to the first and second valve abnormality detection circuits 11 and 12 from the corresponding first and second operation detection switches 7 and 8. Hereinafter, the logical values when the voltage of the input/output signal of the circuit component device is at a high level and a low level will be indicated as "1" and "0", respectively. These valve abnormality detection circuits 11 and 12 have an output signal of "1" when the excitation current starts flowing through the excitation coils 5A and 6A, and an output signal of "0" when the detection signal is output from the operation detection switches 7 and 8.
It is designed to become. Each valve abnormality detection circuit 11,
The output signal from 12 is given to first and second valve operation time detection timers 13 and 14, the duration of the output signal is measured, and when a predetermined time is exceeded, first and second valve abnormality signals are output. It looks like this. These valve abnormality detection circuits 11 and 12 and valve operation time detection timers 3 and 14 constitute first and second valve abnormality determination circuits 15 and 16. The valve abnormality signal from each valve abnormality determination circuit 15, 16 is transmitted to the first, second OR circuit 17, 18, first,
The signal is input as a set signal to the first and second memory circuits 21 and 22 via the second differentiating circuits 19 and 20.

The memory of each memory circuit 21, 22 is erased by a reset signal from a reset switch 23. Each memory circuit 21, 22 has a first and a second electromagnetic valve 1, 2.
It is designed to output an output signal of "1" when it is normal, and to output a "0" signal when it is abnormal. Each memory circuit 21,
The output signal 22 is given to control switches 24 and 25 as first and second discrimination driving means, and is applied to abnormality display means 26 and 27 as first and second abnormality discrimination means such as lamps and light emitting diodes. It is designed to control the display. First and second abnormality display means 26 and 27 When the first and second electromagnetic valves 1 and 2 are normal, they are supplied with power from the AC power source 28 and turn on to indicate normality, and when an abnormality occurs, they turn off and indicate an abnormality. It is supposed to notify you of the occurrence of. Note that this display means is designed to turn on when the electromagnetic valve is normal to indicate normal operation, but it is of course also possible to turn off the light when it is normal and turn on when there is an abnormality. . In this case, the inputs of each control switch 24, 25 may be connected to the side where the output becomes "1" by the set signal of each memory circuit 21, 22. The output signals of the memory circuits 21 and 22 (inverted signals of the valve abnormality signals) are applied to the first and second output switches 29 and 3, respectively.

These output switches 29, 30' are connected in series with an output relay 31, and power is supplied from an AC power source 28 to these series circuits. Each output switch 29
, Mitsukawa are connected to first and second output-side AC-DC conversion circuits 32 and 33 that detect the operating state and perform AC-DC conversion. The output signals of these circuits 32 and 33 are applied to an output relay abnormality detection circuit 34 consisting of an exclusive OR circuit. That is, this output relay abnormality detection circuit 34
In this case, when either one of the AC-DC converter circuits starts outputting DC output, the output signal becomes "1", and both AC-DC converter circuits become "1".
When the conversion circuit starts outputting DC output, the output signal becomes "0". The output signal of such an output relay abnormality detection circuit 34 is given to an output deviation time detection timer 35, which measures the deviation between the operating times of the output switches 29 and 30, and when the time exceeds a predetermined time, outputs an output relay abnormality signal. It's about to come out. These output relay abnormality detection circuit 34 and output deviation time detection timer 35 constitute an output relay abnormality determination circuit 36. The output relay abnormality signal from the output relay abnormality determination circuit 36 is provided as the other input of each of the OR circuits 17 and 18 described above. 37 is one of the relay switches controlled by the excitation of the output relay 31, and is adapted to control the power supply to the excitation coils 5A and 6A.

Now, in such a device, when the operations of both electromagnetic valves 1 and 2 are normal, each valve abnormality determination circuit 15,
No. 16 valve abnormality signal is "0". In this state, each memory circuit 21, 22 has an output signal of “1” due to the initial input.
Therefore, each switch 24, 25, 29, and all three switches are in the on state. For this reason, both the first and second abnormality display means 26 and 27 are lit to indicate normality. Furthermore, power is being supplied to the output relay 31 and the relay switch 37 is turned on. Next, for example, if an abnormality occurs in the first electromagnetic valve 1, the exciting coil 5
After A is excited, the first operation detection switch 7 issues a detection signal (it may not issue it).

), more than a predetermined time has elapsed. Therefore,
Since this time exceeds the set time (for example, 0.1 seconds) of the first valve operation time detection timer 13, the first valve abnormality determination circuit 15 issues a first valve abnormality signal. This valve abnormality signal is differentiated by the differentiating circuit 19 and applied to the first memory circuit 21, to invert its storage state. As a result, the first display control switch 24 is turned off, and the first display control switch 24 is turned off.
The abnormality display means 26 is lit to notify that an abnormality has occurred on the first electromagnetic valve 1 side. Furthermore, when the stored contents of the first memory circuit 21 reach this state, the first output switch 29 is turned off and the output relay 31 is demagnetized.
As a result, the relay switch 37 is turned off, power supply to the excitation coils 5A and 6A is stopped, and the press machine is also stopped. Even when an abnormality occurs in the second electromagnetic valve 2, it is detected in the same manner. Next, when an abnormality occurs in the output switch 29, for example, when an abnormality occurs in the output switch 29, the output switch 29 is turned off at that point.

At this time, only the first output side AC-DC conversion circuit 32 starts outputting a DC output signal, and the second output side AC-DC conversion circuit 33 does not output a DC output signal. 1st AC-DC
When the output signal of the output relay abnormality detection circuit 34 is "1" due to the application of the DC output signal from the conversion circuit 32 and exceeds the set time of the output deviation time detection timer 35, the output relay abnormality determination circuit 36 activates the output relay abnormality detection circuit 34. Gives an abnormal signal. This signal is applied to the first and second memory circuits 21 and 22 via OR circuits 17 and 18 and differentiating circuits 19 and 20, and inverts the respective stored contents. This allows the first and second
Both the abnormality display means 26 and 27 are turned off, and the output relay 31 is demagnetized. If an abnormality is confirmed, the reset switch 23 is pressed to reset the memory contents of each memory circuit 21, 22 to the initial state.

Note that the present invention is not limited to the above embodiments, and the following changes can be made.

In addition to this, the magnetic valve can be suspended in a similar manner by measuring the time from when the excitation current ends flowing through the coil until the operation detection switch ends outputting the detection signal.

When the power source of the excitation coils 5A, 6A and the power source 28 are DC, each AC-DC conversion circuit 9, 10, 32, 33 can be omitted.

The present invention can be similarly applied to a case where the number of electromagnetic valves is one or N.

The abnormality display means 26 and 27 not only display by light but also
Other indications, such as an audible indication, can also be provided.

As explained above, the valve abnormality detection device according to the present invention can be used from the time when the excitation current starts flowing in the excitation coil of the electromagnetic valve until the valve body operates and the operation detection switch starts to output a detection signal, or when the excitation current starts flowing through the excitation coil of the electromagnetic valve. Since abnormalities are determined by measuring the time from when the operation detection switch finishes issuing the detection signal, it is also possible to detect abnormal delayed operation of electromagnetic valves, which was impossible with conventional devices of this type. be able to.

Further, according to the present invention, even if an abnormality occurs in any one of the plurality of electromagnetic valves, the abnormal valve can be immediately pointed out, and repair work can be easily performed. Further, according to the present invention, even if an abnormality such as a shift in operation occurs in each output switch that controls the output relay, this can be detected, and therefore safety can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of a dual valve using the present invention, and FIG. 2 is a block diagram showing an embodiment of the valve abnormality detection device according to the present invention. 1, 2...First and second electromagnetic valves, 3, 4...
... Valve body, 5, 6... Electromagnetic solenoid, 5A,
6A... Excitation coil, 7, 8... 1st, 2nd
operation detection switch, 15, 16... first and second valve abnormality determination circuits, 26, 27... first
, second abnormality display means...29,30...
...first and second output switches, 31...output relay,
36...Output relay abnormality determination circuit. "Fin" Diagram N Chicks

Claims (1)

[Scope of Claims] 1. An operation detection switch that outputs a detection signal when the valve body of the electromagnetic valve is operated, and from the time when an excitation current starts flowing through the excitation coil of the electromagnetic valve until the operation detection switch starts outputting a detection signal, Alternatively, the valve abnormality determination circuit detects the time from when the excitation current ends to when the operation detection switch finishes outputting the detection signal, and outputs a valve abnormality signal when the time exceeds a predetermined time. A valve abnormality detection device characterized by: 2 Excitation current flows through the first to n-th operation detection switches that respectively output detection signals when the valve bodies of the first to n-th electromagnetic valves operate, and to the respective excitation coils of the first to n-th electromagnetic valves. Each time from the start until each of the operation detection switches starts outputting a detection signal, or after the excitation current stops flowing until each operation detection switch ends outputting a detection signal is detected, and each time is determined as a predetermined time. first to nth valve abnormality determination circuits each outputting a valve abnormality signal when the voltage exceeds the threshold; The first part performs abnormality determination operation.
What is claimed is: 1. A valve abnormality detection device comprising: nth to n-th abnormality determination means. 3 Excitation current flows through the first to n-th operation detection switches that output detection signals when the valve bodies of the first to n-th electromagnetic valves operate, and to the respective excitation coils of the first to n-th electromagnetic valves. Each time from the start until each of the operation detection switches starts outputting a detection signal, or after the excitation current stops flowing until each operation detection switch ends outputting a detection signal is detected, and each time is determined as a predetermined time. first to nth valve abnormality determination circuits each outputting a valve abnormality signal when the voltage exceeds the threshold; 1st to nth driven
The output switch, the output relay driven by the on/off of each of the output switches, and the operating state of each of the output switches are detected, and when the deviation in the operating state of any of the output switches exceeds a predetermined time. A valve abnormality detection device comprising: an output relay abnormality determination circuit that outputs an output relay abnormality signal.