JP2017009360A - Fault detection device and failure prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fault detection device capable of easily detecting fault in a plurality of monitoring targets under different conditions.SOLUTION: A fault detection device includes a common electrode 2, detection units 3a-3c configured to detect continuity fault under a plurality of different conditions, resistors R1, R2 connected between respective detection units, and a resistance measurement circuit 5 configured to measure resistance between the common electrode and any one of the detection units.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an abnormality detection device that detects an abnormality in a wiring pattern or the like formed on a printed circuit board or the like.

  In electronic equipment used in environments such as chemical plants and sewage treatment plants, wiring resistance increases or breaks due to corrosion of the wiring pattern formed on the printed circuit board due to corrosive gas or dust contained in the atmosphere, or wiring Problems such as a decrease in insulation may occur.

  Therefore, in such an electronic device, a wiring pattern due to pattern corrosion is formed by forming a simulated pattern on a printed circuit board, applying a reference voltage to one end of the simulated pattern, and detecting the voltage at the other end of the simulated pattern. Some of them are equipped with a detection device that detects an increase, disconnection, or insulation drop.

  Patent Document 1 discloses a detection device in which a detection voltage output from a deterioration detection pattern is converted into a digital value by an A / D converter, and an abnormality of the deterioration detection pattern is detected based on the digital value. Has been.

  Patent Document 2 discloses a control panel including a printed circuit board that can detect a disconnection due to pattern corrosion, a short circuit due to migration, or the like due to a pattern having a narrower width than other wiring or a pattern having a short insulation distance. .

  In Patent Document 3, different types of metals and resistance elements having different resistance values for each metal are connected in series, and these are connected in parallel to determine the resistance value between both terminals of the parallel circuit. A corrosion detection device that detects the corrosion rate of each metal by detection is disclosed.

Japanese Patent Laid-Open No. 10-62476 JP 2001-251026 A JP 2014-153089 A

  In the detection device disclosed in Patent Document 1 and the control panel disclosed in Patent Document 2, in order to detect an abnormality under a plurality of different conditions, a detection pattern and a determination circuit are required for each condition. The configuration of the detection device or the control panel becomes complicated. Further, in order to accurately detect a pattern abnormality, it is necessary to improve the accuracy of the detection circuit or the determination circuit, which causes an increase in cost.

  In the corrosion detection device disclosed in Patent Document 3, since a plurality of corrosion monitoring targets are connected in parallel, when any one of the corrosion monitoring targets is in a high resistance state without being disconnected, any of the corrosion monitoring targets is detected. It may not be possible to determine whether corrosion has progressed.

  This invention is made in view of such a situation, and the objective is to provide the abnormality detection apparatus which can detect easily the abnormality of the several monitoring object of different conditions.

  An abnormality detection device that solves the above problems includes a common electrode, a detection unit that causes an abnormality in conduction to the common electrode under a plurality of different conditions, and a resistor that is connected between the detection units. And a resistance value measuring circuit for supplying a constant voltage to the common electrode and measuring a resistance value between the common electrode and any one of the detection units.

With this configuration, when a conduction abnormality occurs in the detection unit, a change in resistance value is detected by the resistance value measurement circuit.
In the abnormality detection device, the detection unit includes a plurality of detection electrodes each having a different interval from the common electrode, and the resistance measurement circuit includes the electrode having the widest interval from the common electrode and the common electrode. It is preferable to measure a resistance value between the electrodes.

With this configuration, when a short circuit occurs between each detection electrode and the common electrode, a resistance value change is detected by the resistance value measurement circuit.
Further, in the above abnormality detection device, the detection unit includes a plurality of detection patterns whose base end portions are connected to the common electrode and have different conditions for corrosion resistance, and the resistance is provided between the front end portions of the detection patterns. It is preferable that the resistance value measuring circuit measures a resistance value between a tip portion of the detection pattern having the lowest corrosion resistance and the common electrode.

With this configuration, when a disconnection due to corrosion occurs in each detection pattern, a resistance value change is detected by the resistance value measurement circuit.
Further, in the abnormality detection apparatus, the detection unit includes a plurality of temperature fuses each having one end connected to the common electrode and different fusing temperatures, and the resistor is provided between the other end portions of the temperature fuse. The resistance value measuring circuit is connected and can detect the temperature reached at the measurement point by measuring the resistance value between the other end of the thermal fuse having the lowest fusing temperature and the common electrode.

With this configuration, when each temperature fuse is blown, the resistance value detection circuit detects a change in resistance value.
In the abnormality detection apparatus, it is preferable that a plurality of detection units connected to the resistor are connected in series between a constant voltage supply terminal and a resistance value detection terminal of the resistance value measurement circuit.

With this configuration, the resistance value measurement circuit can detect the change in the resistance value in multiple stages by a large number of detection units.
In addition, the failure prevention apparatus that solves the above problems includes a determination unit that determines abnormality based on a measurement value of a resistance value measurement circuit of the abnormality detection device, and an abnormality that suppresses the cause of the abnormality based on the determination result of the determination unit And a suppression device.

  With this configuration, when an abnormality is determined, the abnormality cause is suppressed by the abnormality suppressing device.

  According to the abnormality detection device of the present invention, it is possible to easily detect abnormality of a plurality of monitoring targets under different conditions.

It is a block diagram which shows a failure prevention apparatus. It is a circuit diagram which shows the wiring abnormality detection circuit of 2nd embodiment. It is a block diagram which shows 3rd embodiment. It is a circuit diagram which shows 4th embodiment.

(First embodiment)
FIG. 1 shows an installation of an environment containing a corrosive gas such as hydrogen sulfide in an atmosphere. By detecting the occurrence of migration due to the corrosive gas, the wiring pattern of another electronic device installed in the environment is abnormal. An example of the failure prevention apparatus for preventing a failure in advance is shown.

  In the wiring abnormality detection circuit 1 provided in the failure prevention device, the detection electrodes 3a, 3b, and 3c are arranged to face the common electrode 2. The intervals between the detection electrodes 3a, 3b, 3c and the common electrode 2 are set to different intervals.

  The distance between the detection electrode 3a and the common electrode 2 is the smallest, and the distance between the detection electrode 3c and the common electrode 2 is the largest. The distance between the detection electrode 3b and the common electrode 2 is intermediate between the detection electrode 3a and the detection electrode 3c.

A plurality of irregularities 4 having a triangular cross section are continuously formed on the surface of the detection electrode 3a facing the common electrode.
The detection electrode 3a and the detection electrode 3b are connected via a resistor R1, and the detection electrode 3b and the detection electrode 3c are connected via a resistor R2. In this embodiment, the resistance values of the resistors R1 and R2 are set to about 3 to 10 times the resistance value of the resistor R2, and the resistance values of the resistors R1 and R2 are in the range of 1 to 100 kΩ. It is desirable to set with.

  A constant voltage is applied to the common electrode 2 from the resistance value measurement circuit 5, and the detection electrode 3 c is connected to the resistance value measurement circuit 5. In the resistance value measurement circuit 5, the resistance value between the common electrode 2 and the detection electrode 3c is based on the constant voltage applied to the common electrode 2 and the current value flowing from the detection electrode 3c to the resistance value measurement circuit 5. It is to be measured.

  With such a configuration, for example, when only the detection electrode 3a is short-circuited with the common electrode, the resistance value detected by the resistance value measurement circuit 5 is R1 + R2. Further, when the detection electrode 3b is in a short circuit state, the resistance value detected by the resistance value measuring circuit 5 is R2. Further, when the detection electrode 3c is in a short circuit state, the resistance value detected by the resistance value measuring circuit 5 becomes almost zero. If all of the detection electrodes 3a to 3c are in a non-conductive state, the resistance value detected by the resistance value measuring circuit 5 is infinite.

Therefore, in the wiring abnormality detection circuit 1, different resistance values can be detected by the resistance value measurement circuit 5 based on which detection electrode is in a short circuit state.
The resistance value measured by the resistance value measurement circuit 5 is output to the resistance value determination circuit 6. The resistance value determination circuit 6 determines the progress of migration based on the input resistance value and outputs the determination signal to the fan control circuit 7.

  The fan control circuit 7 controls the air flow rate of the fan 8 based on the determination signal. Then, based on the operation of the fan 8, the atmosphere around the installation environment of the electronic device is ventilated through the corrosive gas removing device 9, and the corrosive gas is removed. The corrosive gas removing device 9 contains iodine-impregnated charcoal as a corrosive gas adsorbent.

Next, the operation of the failure prevention apparatus configured as described above will be described.
When the installation environment of the failure prevention apparatus is favorable, insulation between the common electrode 2 and the detection electrodes 3a to 3c is ensured in a state where a constant voltage is applied to the common electrode 2. Then, since the resistance value between the common electrode 2 and the detection electrode 3c becomes almost infinite, the resistance value determination circuit 6 determines that migration is not progressing based on the input resistance value. As a result, the fan 8 is not operated or the air flow rate is set low.

  In a situation in which corrosion gas, salt, humidity, or the like increases in the atmosphere in the installation environment of the failure prevention apparatus and migration tends to occur in the wiring pattern of the electronic device, migration is performed as the electrode is closer to the common electrode 2. Easy to progress. Therefore, first, migration occurs in the uneven portion 4 of the detection electrode 3a, so that the insulation with the common electrode 2 is lowered, or a short circuit state occurs.

  In this state, the resistance value between the common electrode 2 and the detection electrode 3c measured by the resistance value measurement circuit 5 decreases to R1 + R2. Then, the resistance value determination circuit 6 determines that migration due to corrosive gas or the like is likely to occur in the wiring pattern of the adjacent electronic device.

  In addition, when the insulation between the common electrode 2 and the detection electrode 3b is reduced or when a short circuit occurs, the resistance value between the common electrode 2 and the detection electrode 3c is reduced to approximately R2. Then, the resistance value determination circuit 6 determines that the migration is more likely to occur in the wiring pattern of the adjacent electronic device.

  Further, when the insulation between the common electrode 2 and the detection electrode 3c is lowered or short-circuited, the resistance value between the common electrode 2 and the detection electrode 3c becomes almost zero. Then, the resistance value determination circuit 6 determines that the migration is more likely to occur in the wiring pattern of the adjacent electronic device.

  Based on such a determination result, the fan 8 is operated or the air flow rate is increased to remove the corrosive gas from the atmosphere, and the printed circuit board of the electronic device is replaced as necessary.

The voltage application to the common electrode 2 may be either always or intermittently, but it is desirable to always apply the voltage in order to promote the progress of migration.
If the supply of the constant voltage to the common electrode 2 is stopped when the detection electrode 3c is short-circuited, useless power consumption can be suppressed.

  Further, if the resistance value between the common electrode 2 and the detection electrode 3c is measured at regular time intervals such as once a day, for example, it is approximately until the detection electrodes 3a to 3c having different conditions are short-circuited. Can be detected.

And when a short circuit of each electrode is detected, you may make it output a warning signal and a warning signal sequentially.
In the failure prevention apparatus as described above, the following effects can be obtained.
(1) By detecting a change in the resistance value between the common electrode 2 and the detection electrode 3c, it is possible to detect a decrease in insulation or a short circuit due to migration in the detection electrodes 3a to 3c. Therefore, it is possible to estimate the damage of the printed circuit board of the electronic device that is disposed adjacently.
(2) By measuring the three-stage resistance change between the common electrode 2 and the detection electrodes 3a to 3c with one wiring abnormality detection circuit 1 and the resistance value measurement circuit 5, three kinds of line widths are measured. The possibility of occurrence of a short circuit due to migration in the gap between the wiring patterns can be determined. Therefore, the possibility of occurrence of an abnormality under a plurality of different conditions can be determined with a simple configuration.
(3) Even when the common electrode 2 and each of the detection electrodes 3a to 3c are connected with high resistance by setting the resistance values of the resistors R1 and R2, the state is easily determined based on the change in the resistance value. can do.
(Second embodiment)
FIG. 2 shows another embodiment of the wiring abnormality detection circuit. The same components as those in the first embodiment will be described with the same reference numerals. The wiring abnormality detection circuit 10 of this embodiment is suitable as an abnormality detection unit that detects disconnection of a wiring pattern due to corrosive gas or the like.

  The four detection patterns 12a to 12d extending in parallel from the common electrode 11 are formed with different line widths, and are formed so as to gradually increase from the detection pattern 12a to the detection pattern 12d. The base ends of the detection patterns 12 a to 12 d are connected to the common electrode 11.

  The tip of the detection pattern 12a and the tip of the detection pattern 12b are connected via a resistor R3, and the tip of the detection pattern 12b and the tip of the detection pattern 12c are connected via a resistor R4. The tip of the detection pattern 12c and the detection pattern The tip of 12d is connected via a resistor R5. The resistance values of the resistors R3 to R5 are the same in this embodiment.

A constant voltage is supplied to the common electrode 11 from the resistance value measurement circuit 5, and a terminal of the detection pattern 12 a is connected to the resistance value measurement circuit 5.
In addition, it is preferable that the common electrode 11 has a configuration in which corrosion due to a corrosive gas does not occur due to resin coating or plating.

  In the wiring abnormality detection circuit 10 configured as described above, the resistance value between the common electrode 11 and the wiring pattern 12a is substantially zero if the detection patterns 12a to 12d are not disconnected due to corrosion.

  When the corrosion of the wiring patterns 12a to 12d proceeds due to the corrosive gas, the wiring pattern 12a is first disconnected. Then, the resistance value between the common electrode 11 and the tip of the wiring pattern 12a measured by the resistance value measuring circuit 5 is the resistance value of the resistor R3.

Next, when the wiring pattern 12b is disconnected, the resistance value between the common electrode 11 and the tip of the wiring pattern 12a is the sum of the resistance values of the resistors R3 and R4.
Next, when the wiring pattern 12c is disconnected, the resistance value between the common electrode 11 and the tip of the wiring pattern 12a is the sum of the resistance values of the resistors R3, R4, and R5.

Next, when the wiring pattern 12d is disconnected, the resistance value between the common electrode 11 and the tip of the wiring pattern 12a becomes almost infinite.
In addition, if a constant voltage is applied to the common electrode 11 at regular time intervals, for example, once a day, and the resistance value between the common electrode 11 and the detection pattern 12a is measured, detection under different conditions is performed. It is possible to determine whether there is an abnormality in the patterns 12a to 12d.

When such a wiring abnormality detection circuit 10 is used in a failure prevention device similar to that of the first embodiment, the following effects can be obtained.
(1) By detecting a change in resistance value between the common electrode 11 and the detection pattern 12a, it is possible to detect disconnection due to corrosion in the detection patterns 12a to 12d under a plurality of different conditions.
(2) One wiring abnormality detection circuit 10 and the resistance value measurement circuit 5 measure the change in resistance value in four steps between the common electrode 11 and the tips of the detection patterns 12a to 12d, thereby causing a wiring abnormality detection circuit. The possibility of disconnection due to corrosion of the corresponding four kinds of different wiring patterns in the electronic device disposed adjacent to the circuit 10 can be determined. Therefore, the possibility of disconnection of the wiring pattern under a plurality of different conditions can be determined with a simple configuration.
(Third embodiment)
FIG. 3 shows another embodiment of the wiring abnormality detection circuit. In this embodiment, wiring abnormality detection circuits 13a to 13c similar to the wiring abnormality detection circuit 10 of the second embodiment are connected in three stages in series.

  The abnormality detection units 13a to 13c are similar in circuit to the wiring abnormality detection circuit 10 of the second embodiment, and the detection pattern conditions of the abnormality detection units 13a to 13c are different. Then, a detection pattern is formed in which conditions are severe from the abnormality detection unit 13a toward the same 13c, and the wire is easily disconnected due to corrosion.

With such a configuration, it is possible to determine the possibility of disconnection in a number of different conditions and places as compared to the second embodiment.
(Fourth embodiment)
FIG. 4 shows another embodiment of the abnormality detection unit. The abnormality detection circuit 14 of this embodiment detects an abnormal increase in temperature at the installation position of the electronic device, and the detection patterns 12a to 12d of the wiring abnormality detection circuit 10 of the second embodiment are used as the temperature fuses 15a to 15a. It is replaced with 15d.

  The fusing temperatures of the temperature fuses 15a to 15d are set so as to increase sequentially from the temperature fuse 15a toward the fifteenth d. For example, the fusing temperature of the temperature fuse 15a is 80 ° C., the fusing temperature of the temperature fuse 15b is 100 ° C., and the temperature fuse The fusing temperature of 15c is 120 ° C., and the fusing temperature of the thermal fuse 15d is 140 ° C.

  With such a configuration, when the temperature fuses 15a to 15d are sequentially blown in this order due to an increase in the ambient temperature, the resistance values detected by the resistance value measuring circuit 5 are sequentially increased. When all the thermal fuses 15a to 15d are blown, the resistance value detected by the resistance value measuring circuit 5 becomes infinite.

By such an operation, an increase in temperature can be detected in stages.
In addition, you may change the said embodiment as follows.
-In 1st embodiment, you may provide an unevenness | corrugation in all the opposing surfaces with the common electrode of a 1st-3rd detection electrode.
-In 1st embodiment, you may provide a some perforation part in the opposing surface with the common electrode of a 1st-3rd detection electrode.
In the second embodiment, instead of detection patterns with different line widths, detection patterns with different conditions may be formed by changing the thickness of the pattern.
In the second embodiment, detection patterns having different conditions may be formed by changing the material of the detection pattern, such as copper or silver.
-The wiring abnormality detection circuit 1 of the first embodiment and the wiring abnormality detection circuit of the second embodiment are operated in parallel to detect wiring abnormality due to migration and wiring abnormality due to corrosion in parallel. May be.

DESCRIPTION OF SYMBOLS 1,10,13a-13c, 14 ... Detection circuit (abnormality detection circuit), 2,11 ... Common electrode, 3a-3c ... Detection part (detection electrode), 4 ... Concavity and convexity, 5 ... Resistance value measurement circuit, 6 ... Determination Parts (resistance value determination circuit), 7 ... abnormality suppression device (fan control circuit), 8 ... abnormality suppression device (fan), 9 ... abnormality suppression device (corrosion gas removal device), 12a to 12d ... detection unit (detection pattern) , 15... Detection unit (temperature fuse).

Claims (6)

A common electrode;
For the common electrode, a detection unit configured to cause conduction abnormality under a plurality of different conditions;
Resistors respectively connected between the detection units;
An abnormality detection apparatus comprising: a resistance value measurement circuit that supplies a constant voltage to the common electrode and measures a resistance value between the common electrode and any one of the detection units. The abnormality detection device according to claim 1,
The detection unit includes a plurality of detection electrodes each having a different interval from the common electrode,
The abnormality detection device, wherein the resistance value measurement circuit measures a resistance value between an electrode having the widest distance from the common electrode and the common electrode. The abnormality detection device according to claim 1,
The detection unit includes a plurality of detection patterns in which a base end portion is connected to the common electrode and conditions for corrosion resistance are different from each other.
Connecting each of the resistors between the ends of the detection pattern;
The abnormality detection device, wherein the resistance value measurement circuit measures a resistance value between a tip portion of the detection pattern having the lowest corrosion resistance and the common electrode. The abnormality detection device according to claim 1,
The detection unit includes a plurality of temperature fuses each having one end connected to the common electrode and different fusing temperatures,
Connecting each of the resistors between the other ends of the thermal fuse;
The resistance value measuring circuit measures a resistance value between the other end of the thermal fuse having the lowest fusing temperature and the common electrode. In the abnormality detection device according to claim 3 or 4,
An abnormality detection device, wherein a plurality of detection units connected to the resistor are connected in series between a constant voltage supply terminal and a resistance value detection terminal of the resistance value measurement circuit. A determination unit that determines an abnormality based on a measurement value of a resistance value measurement circuit of the abnormality detection device according to any one of claims 1 to 5;
A failure prevention apparatus comprising: an abnormality suppression apparatus that suppresses an abnormality cause based on a determination result of the determination unit.

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