KR100697948B1 - Malfunction detector - Google Patents

Abstract

assignment

An open / short fault of the SSR device cannot be detected.

Resolution

The SSR apparatus 3 which is arrange | positioned between the heater 1 and the power supply part 1A, adjusts the amount of electric power supplied to a heater from a power supply part according to a temperature control control signal, and monitors the temperature of a heater, and based on this monitoring result In order to set the temperature of a heater to a target temperature, it is connected to the temperature control system which has a temperature control apparatus 6 which outputs a temperature control control signal, and is a failure detection apparatus 4 which detects the failure of an SSR apparatus, and temperature control A temperature control control signal determination unit 33 for determining whether the control signal is in an on state, a heater current determination unit 34 for determining whether a heater current between the SSR apparatus and the heater is in an on state, and temperature control control The SSR failure determination part 35 which judged the failure of the SSR apparatus based on the determination result of the signal determination part, and the determination result of the heater current determination part is provided.

Fault detection

Description

Fault detection device {MALFUNCTION DETECTOR}

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows schematic structure of the whole temperature control system which shows 1st Embodiment which concerns on the failure detection apparatus of this invention.

Fig. 2 is a block diagram showing a schematic configuration inside the failure detection device according to the first embodiment.

Fig. 3 is a block diagram showing a schematic configuration inside a CPU in the failure detection device according to the first embodiment.

4 is a block diagram showing an example of a heater current measurement unit inside the CPU according to the first embodiment.

Fig. 5 is a block diagram showing an example of a heater current measurement unit inside the CPU according to the first embodiment.

Fig. 6 is a block diagram showing a schematic configuration inside a CPU in the failure detection device according to the second embodiment.

7 is an explanatory diagram showing a system configuration of a temperature control system according to another embodiment.

8 is a block diagram showing a schematic configuration of an entire temperature control system according to another embodiment.

♠ Explanation of symbols on the main parts of the drawings.

1: heater

1A: Power section

2: temperature control system

3: SSR device

4: failure detection device

32: heater current measuring unit (heater current detecting means)

33: temperature regulation control signal determination unit (first determination means)

34: heater current determination unit (second determination means)

35: SSR failure determination unit (failure determination means)

36: output processing unit (notification means)

42, 52: A / D sampling value acquisition unit (A / D sampling value acquisition unit)

43: basic value calculating part (basic value calculating means)

44, 53: heater current value conversion unit (heater current value conversion means)

61: layer short threshold memory (layer short threshold memory)

62: threshold adjustment unit (layer short threshold adjustment means)

63: heater layer short determination unit (layer short threshold determination means and layer short determination means)

b: heater current detection circuit (heater current detection means)

D: notification control circuit (notification means)

Technical field

The present invention is, for example, disposed between a heater to be used for an industrial furnace heater, a semiconductor cleaning device, a plastic molding machine, and the like, a power supply unit for supplying electric power to the heater, and a heater and a power supply unit. A solid state relay device (hereinafter referred to simply as an SSR device) that adjusts the amount of power supplied from the power supply unit to the heater in accordance with an adjustment control signal, and the temperature of the heater is monitored, and the temperature of the heater is based on the monitoring result. To a temperature control system having a temperature control device for outputting the temperature control control signal to set a target temperature to a target temperature, and a failure detection device for detecting a failure of the SSR device or the heater.

Background technology

Background Art Conventionally, for example, in a plastic molding machine, a heater to be controlled disposed in an injection cylinder, a power supply unit for supplying electric power to the heater, and disposed between these heaters and a power supply unit, and the power supply unit is arranged from the power supply unit according to a temperature control control signal. In order to monitor the temperature of the solid state relay device (hereinafter only referred to as SSR device) for adjusting the amount of power supplied to the heater and the heater, and to set the temperature of the heater to a target temperature based on the monitoring result, Background Art A temperature regulation system having a temperature regulation device for outputting a temperature regulation control signal is known.

According to such a temperature control system, in order to detect faults, such as a disconnection of a heater quickly, the fault detection apparatus demonstrated below is known.

This failure detection apparatus memorizes in advance the control amount of the temperature control control signal at the time until the heater temperature reaches the target temperature, and the temperature control control signal until the heater temperature reaches the target temperature in the temperature adjusting device. The control amount is measured, the measured control amount is compared with the stored control amount during normal operation, and when the comparison result exceeds a predetermined threshold and the control amount is increased during measurement, the heater is judged to be disconnected (for example, Patent Document 1 Reference).

According to the failure detection device of Patent Document 1, it is possible to monitor the control amount of the temperature control control signal to the SSR device and detect the disconnection of the heater without using the heater current meter for measuring the heater current.

In addition, as another fault detection apparatus, a current transformer for detecting a heater current, a DC voltage output circuit for outputting a DC voltage corresponding to the heater current of the current transformer, and a plurality of times that the DC voltage is digitally converted and sampled at predetermined intervals is accepted. The reference value of the heater current is determined based on the means for calculating the moving average value of the input signal and the calculated moving average value, and the reference value of the heater current is compared with the current value of the current, and the heater is performed when the current value is smaller than the reference value. It is known to have a heater disconnection determination means judged to be disconnection (see Patent Document 2, for example).

According to the failure detection device of Patent Literature 2, the moving average value of a plurality of input signals sampled at predetermined intervals is calculated, and the reference value of the heater current is determined based on the calculated moving average value, and the reference value of the heater current and Since the current value is compared and it is judged that the heater is disconnected when the current value is smaller than the reference value, the disconnection of the heater can be reliably detected by resetting the reference value even if the characteristic is changed due to the secular variation of the heater. have.

[Patent Document 1]

Japanese Patent Laid-Open No. 2002-343537 (see [0079] and FIG. 14).

[Patent Document 2]

Unexamined Patent Application No. 7-41117 (Refer to [Scope of Utility Model Registration Claim] and FIG. 2)

However, according to the failure detection device of Patent Document 1, the temperature adjusting device measures the control amount of the temperature control control signal until the temperature of the heater reaches the target temperature, and the measured control amount and the control amount at the time of normal storage are measured. In comparison, when the comparison result exceeds a predetermined threshold and the control amount during the measurement becomes large, the heater is determined to be disconnected. However, failure of the SSR device in the temperature control system, for example, open failure or short failure cannot be determined.

In addition, according to the failure detection device of Patent Document 2, a moving average value of a plurality of times of input signals sampled at predetermined intervals is calculated, and the reference value of the heater current is determined based on the calculated moving average value, It is possible to reliably detect the disconnection of the heater by comparing the reference value with the current value, and determining that the heater is disconnected when the current value is less than the reference value, and resetting the reference value even if the characteristics have changed due to the secular variation of the heater. Although it is possible to, the heater disconnection life before the heater disconnection is not recognized.

The present invention has been made in view of the above problems, and an object thereof is to provide a failure detection device capable of detecting a failure of an SSR device.

Another object of the present invention is to provide a failure detection apparatus capable of recognizing a heater disconnection life, that is, a layer short before the heater disconnection.

In order to achieve the above object, the failure detection device of the present invention is arranged between a heater to be controlled, a power supply unit for supplying electric power to the heater, and between these heaters and the power supply unit, and the heater from the power supply unit in accordance with a temperature control control signal. And a temperature adjusting device that monitors the temperature of the heater and outputs the temperature control control signal to set the temperature of the heater to a target temperature based on the monitoring result. A failure detection device connected to a temperature control system and detecting a failure of the SSR device, comprising: heater current detection means for detecting a heater current between the SSR device and the heater, and a control amount of the temperature control control signal equal to or greater than a first predetermined level First determining means for determining whether or not the first and second heater currents detected by the heater current detecting means are second predetermined; Bell was to have a second determination means, and deterioration determining means for determining a failure of the SSR device in accordance with the determination result of the determination result and the second determination means of the first determining means for determining whether or not the above.

In the failure detecting device of the present invention, the failure determining means determines that the temperature control control signal is a control amount equal to or greater than a first predetermined level in the first determining means, and the heater current is determined by the second determining means in a second predetermined amount. If it is determined that the level is not abnormal, it is determined that the SSR open failure of the SSR device.

In the failure detecting apparatus of the present invention, the failure determining means determines that the temperature control control signal is not a control amount equal to or greater than a first predetermined level in the first determining means, and the heater current is second in the second determining means. When it is determined that the predetermined level or more is determined, it is determined that the SSR short failure of the SSR device.

The failure detection apparatus of the present invention has a notification means for notifying and outputting the determination result of the failure determination means.

The failure detection device of the present invention includes: A / D sampling value acquisition means, wherein the heater current detection means acquires a predetermined number of A / D sampling values within a predetermined period between the SSR device and the heater; By a base value calculating means for calculating a base value based on a predetermined number of A / D sampling values acquired by said A / D sampling value obtaining means, and by a square-average value of the base value for a predetermined period calculated by this base value calculating means. It was made to have the heater electric current value converting means converted into the calculated electric current value as the heater electric current value judged by the said 2nd determination means.

In the fault detection apparatus of the present invention, the heater current detecting means has A / D in which the heater current value between the SSR apparatus and the heater is full-wave rectified to obtain a predetermined number of A / D sampling values within a predetermined period. The current value calculated by integrating the D sampling acquiring means and the A / D sampling values for the predetermined number and squared-averaging the integrated A / D sampling value is converted into a heater current value determined by the second determining means. It was made to have a heater current value converting means.

The failure detection device of the present invention has wireless communication means for wirelessly connecting with a higher level device and another failure detection device, and through the wireless communication means, determines a result of the determination of the failure determination means, either the higher level device or the other failure detection device. Send and receive between and.

Moreover, in order to achieve the said objective, the fault detection apparatus of this invention is arrange | positioned at the heater of a control object, the power supply part which supplies electric power to this heater, these heaters, and a power supply part, and is provided from the said power supply part according to a temperature control control signal. An SSR device for adjusting the amount of power supplied to the heater, and a temperature adjusting device for monitoring the temperature of the heater and outputting the temperature control control signal to set the temperature of the heater to a target temperature based on the monitoring result. A failure detection device for detecting a failure of the heater, connected to a temperature control system having: a heater current detection means for detecting a heater current between the SSR device and the heater, and an overcurrent value immediately before disconnection of the heater; And a layer short threshold memory means for storing in advance as the memory and the heater current detection means. When it is shipped, layer short threshold determination means for determining whether or not this heater current has exceeded the layer short threshold stored in the layer short threshold storage means, and the heater current is determined by the layer short threshold determination means. When it determines with exceeding, it was made to have layer short determination means judged as layer short of the said heater.

The fault detection apparatus of the present invention has first determination means for determining whether the temperature adjustment control signal is a control amount equal to or greater than a first predetermined level, and the layer short determination means includes the temperature adjustment control in the first determination means. If it is determined that the signal is a control amount equal to or greater than the first predetermined level and the layer short threshold determining means determines that the heater current has exceeded the layer short threshold, a determination operation of determining that the heater is a layer short is performed. If it is determined in the layer short threshold value determining means that the heater current has exceeded the layer short threshold value, and the first judgment means determines that the temperature control control signal is not a control amount equal to or greater than a first predetermined level, the layer of the heater. The judgment operation judged as a short was prohibited.

The fault detection apparatus of the present invention adjusts the layer short threshold stored in the layer short threshold storage means based on a set current value of the temperature control control signal, and the adjusted layer short threshold value is stored in the layer short threshold storage means. Has a layer short threshold adjusting means for memory updating.

The failure detection apparatus of the present invention has a notification means for notifying and outputting this determination result when the layer short determination means determines that the heater is a layer short.

The failure detection device of the present invention includes: A / D sampling value acquisition means, wherein the heater current detection means acquires a predetermined number of A / D sampling values within a predetermined period between the SSR device and the heater; A basic value calculating means for calculating a base value on the basis of a predetermined number of A / D sampling values obtained by the A / D sampling value obtaining means, and a base value of a predetermined period portion calculated by the base value calculating means as a square average value; The current value calculated by this was provided with the heater current value converting means converted into the said heater current value determined by the said layer short threshold value determination means.

In the fault detection apparatus of the present invention, A / D sampling acquisition means in which the heater current detecting means propagates and rectifies a heater current value between the SSR device and the heater to obtain a predetermined number of A / D sampling values within a predetermined period. And a heater current value that is converted into the heater current value determined by the layer short threshold value determination means by integrating the predetermined number of A / D sampling values and square-averaging the integrated A / D sampling value. It was made to have a conversion means.

The failure detection apparatus of the present invention has wireless communication means for wirelessly connecting with a higher level device and another failure detection device, and the determination result of the layer short decision means is determined by the higher level device or the other failure detection device through the wireless communication means. Send and receive between and.

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Hereinafter, the temperature control system which shows embodiment which concerns on the failure detection apparatus of this invention based on drawing is demonstrated.

(Embodiment 1)

FIG. 1 is a block diagram showing a schematic configuration inside a temperature control system showing a first embodiment.

The temperature control system 10 shown in FIG. 1 is, for example, a heater 1 to be controlled arranged in a cylinder in an injection molding machine, and a three-phase AC power supply unit (hereinafter, simply referred to as a power supply unit) that supplies electric power to the heater 1. 1 A and the SSR apparatus 3 which is arrange | positioned between these heater 1 and the power supply part 1A, and adjusts the electric power amount supplied from the power supply part 1A to the heater 1 according to a temperature control control signal, In order to monitor the temperature of the heater 1 with the temperature sensor which is not shown in figure, and to set the temperature of the heater 1 to a target temperature based on this monitoring result, the temperature adjusting apparatus 6 which outputs a temperature control control signal, and ON / OFF of the temperature control control signal between the heater current detectors 5 (5A, 5B) for detecting the heater current between the SSR device 3 and the heater 1, and the temperature regulating device 6 and the SSR device 3. The high state of the SSR device 3 is based on the off state and the on / off state of the heater current detected by the heater current detector 5. It has the failure detection apparatus 4 which determines a fault.

FIG. 2 is a block diagram showing a schematic configuration inside the failure detection apparatus 4 according to the first embodiment.

The failure detection device 4 shown in FIG. 2 includes a temperature control control signal monitoring circuit A for monitoring a temperature control control signal transmitted between the SSR device 3 and the temperature adjusting device 6, and a heater current detector. The heater current detection circuit B which detects the heater current from (5), the power supply circuit C which supplies electric power to the failure detection apparatus 4, and the failure detection apparatus 4 itself are turned on / off. A switch input circuit 17, a memory circuit 12 for storing various types of information, a notification control circuit D for notifying and outputting various types of information, a CPU 11 for controlling the entire failure detection device 4, And a communication interface E in charge of the communication interface with the upper level personal computer (hereinafter only referred to as the upper level PC) 100, and a reset / power end detection circuit 18 for detecting a reset or a power supply end.

The temperature control signal monitoring circuit A monitors the voltage value between the SSR device 3 and the temperature control device 6, which is necessary for determining the on / off state of the temperature control control signal, and monitors the voltage value of the photocoupler. (14) The CPU 11 is notified by way of example. In addition, it is assumed that the temperature regulation control signal monitoring circuit A and the CPU 11 are insulated from each other, and are connected by infrared rays by the photocoupler 14. In addition, voltage values are two types, 0v and 5v.

The heater current detection circuit B digitally converts the heater current detected by the heater current detector 5 and notifies the CPU 11, and detected by the detection unit CT1 5A in the heater current detector 5. The A / D conversion circuit 16A for digitally converting the heater current and the A / D conversion circuit 16A are disposed in front of the A / D conversion circuit 16A so as to protect the A / D conversion circuit 16A. The over-input protection circuit 15A for preventing an error, the A / D conversion circuit 16B for digitally converting the heater current detected by the detection unit CT2 5B in the heater current detector 5, and the A / D conversion. It has the over input protection circuit 15B which protects the circuit 16B.

The power supply circuit C is a circuit for supplying power to the failure detection device 4 main body, and a full-wave rectifier circuit 26 for full-wave rectifying the power supply voltage obtained from the commercial power supply via the over-input protection circuit 24. The switching power supply circuit 27 generates a power supply voltage on the secondary coil side by supplying and switching the full-wave rectified power supply voltage to the primary coil side, and the power supply voltage generated in the secondary coil by the power supply according to each circuit. Constant voltage circuits 28A, 28B, 28C for converting to voltage and voltage level detection circuit 25 for monitoring the level of the power supply voltage from the commercial power supply are included.

The notification control circuit D includes a display LED drive circuit 22 for driving control of the LED 23 according to a failure notification signal from the CPU 11 described later, and a photocoupler 20 for alarm output in accordance with the failure notification signal. ) And a drive circuit 19 for driving control of the output relay 21.

The communication interface E is a part in charge of the communication interface between the host PC 100 and the CPU 11, and the driver 30 for controlling the drive of the photocoupler 30A and the over-input protecting the driver 30. It has a protection circuit 29, and performs communication operation between the host PC 100 and the CPU 11 via the photocoupler 30A.

3 is a block diagram showing a schematic configuration inside the CPU 11 in the failure detection apparatus 4 according to the first embodiment.

The CPU 11 includes a temperature control signal detection unit 31 for detecting a voltage value of the temperature control signal between the SSR device 3 and the temperature control device 6 via the temperature control signal monitoring circuit A; The on-state or off-state of the temperature control control signal is determined based on the heater current measuring unit 32 that measures the heater current value through the heater current detection circuit B and the voltage value detected by the temperature control control signal detection unit 31. A temperature adjustment control signal 33 and a heater current determination unit 34 that determines an on state or an off state of the heater current based on the heater current value measured by the heater current measurement unit 32. An SSR failure determination unit 35 that determines the failure details of the SSR device 3 based on the determination result of the determination unit 33 and the determination result of the heater current determination unit 34, and the SSR failure determination unit 35. Fault notification signal based on the judgment result It has an output processor 36 for outputting.

When it is determined that the control amount of the temperature control signal, for example, the voltage value is 5v continuously for 100 m seconds, the temperature control control signal determination unit 33 determines that the same temperature control control signal is on, and the voltage value continues for 100 m seconds. If it is determined not to be 5v, it is determined that the same temperature control signal is off.

If it is determined that the heater current is 45% or more of the measured minimum current value of the heater current, the heater current determination unit 34 determines that the heater current is on, and if it is determined that the heater current is not 45% or more of the measured minimum current value of the heater current, the heater It is determined that the current is off.

The SSR failure determination unit 35 determines that the temperature control control signal is in the on state by the temperature control control signal determination unit 33, and determines that the heater current is in the on state in the heater current determination unit 34. (3) is judged to be normal.

When the SSR failure determination unit 35 determines that the temperature control control signal is in the on state by the temperature control control signal determination unit 33 and also determines that the heater current is in the off state in the heater current determination unit 34, the SSR device is determined. It is judged that (3) is an open fault.

In addition, when the SSR failure determination unit 35 determines that the temperature control control signal is in the off state by the temperature control control signal determination unit 33, and determines that the heater current is in the on state in the heater current determination unit 34, It is judged that the SSR apparatus 3 is a short failure.

When the SSR failure determining unit 35 determines that the SSR device 3 is an open failure, the output processing unit 36 outputs a failure notification signal corresponding to the open failure to the drive circuit 19 and the SSR. If the failure determination unit 35 determines that the short failure of the SSR device 3 occurs, the failure notification signal corresponding to the short failure is output to the drive circuit 19.

In addition, the power supply unit according to the claims, the power supply unit 1A, the heater current detection means is a heater current detection circuit (B) and the heater current measurement unit 32, the first determination means is a temperature control control signal determination unit 33, the second determination The means is a heater current determination unit 34, the failure determination unit is an SSR failure determination unit 35, the control amount of the first predetermined level or more is a voltage value of 5v or more, the second predetermined level is 45% of the measured minimum current value, and the notification means is output. This corresponds to the processing unit 36 and the notification control circuit D. FIG.

Next, operation | movement of the failure detection apparatus 4 in the temperature control system 10 which shows 1st Embodiment is demonstrated.

The temperature regulation control signal monitoring circuit A in the failure detection apparatus 4 monitors the voltage value of the temperature regulation control signal transmitted between the SSR apparatus 3 and the temperature regulation apparatus 6, and this voltage value is measured by a photocoupler ( 14) The CPU 11 is notified.

When the temperature control signal detection unit 31 in the CPU 11 detects the voltage value of the temperature control control signal via the photocoupler 14, the temperature control signal detection unit 31 transmits the voltage value to the temperature control control signal determination unit 33.

The temperature control control signal determination unit 33 determines whether the voltage value of the temperature control control signal is 5v or more continuously for 100m seconds, and if it is determined that the voltage value is 5v or more continuously for 100m seconds, the temperature control control signal is It judges that it is an ON state, and transmits this determination result to the SSR failure determination part 35. FIG. In addition, if it is determined that the voltage value of the temperature control control signal is not 5v or more continuously for 100 m seconds, it is determined that the temperature control control signal is in an off state, and the determination result is transmitted to the SSR failure determining unit 35.

In addition, the heater current detection circuit B in the failure detection device 4 digitally converts the heater current detected by the heater current detector 5, and transmits the digitally converted heater current to the CPU 11.

The heater current measurement unit 32 of the CPU 11 measures the heater current value based on the heater current from the heater current detection circuit B, and transmits this heater current value to the heater current determination unit 34.

The heater current determination unit 34 determines whether the heater current value is 45% or more of the measured minimum current value, and when the heater current value is determined to be 45% or more of the measured minimum current value, determines that the heater current is on. This determination result is transmitted to the SSR failure determination unit 35. If it is determined that the heater current value is not 45% or more of the measured minimum current value, it is determined that the heater current is in an off state, and the determination result is transmitted to the SSR failure determination unit 35.

When the SSR failure determination unit 35 determines that the temperature control control signal is in the on state by the temperature control control signal determination unit 33 and also determines that the heater current is in the off state in the heater current determination unit 34, the SSR device is determined. It judges that (3) is an open fault, and notifies the output processing part 36 of this determination result.

The output processing unit 36 notifies the drive circuit 19 and the display LED drive circuit 22 of the failure notification signal corresponding to the open failure of the SSR device 3. When the drive circuit 19 detects the failure notification signal, the drive circuit 19 drives the photocoupler 20 or the output relay 21 to control the alarm of the open failure of the SSR device 3. In addition, when the display LED drive circuit 22 detects the failure notification signal, the display LED drive circuit 22 drives the LED 23 to control the open failure of the SSR device 3.

In addition, when the SSR failure determination unit 35 determines that the temperature control control signal is in the off state by the temperature control control signal determination unit 33, and determines that the heater current is in the on state in the heater current determination unit 34, The SSR device 3 determines that a short failure occurs, and notifies the output processing unit 36 of this determination result.

The output processing unit 36 notifies the drive circuit 19 and the display LED drive circuit 22 of the failure notification signal corresponding to the short failure of the SSR device 3. When the drive circuit 19 detects the failure notification signal, the drive circuit 19 drives the photocoupler 20 or the output relay 21 to control the short failure of the SSR device 3. In addition, when the display LED drive circuit 22 detects the failure notification signal, it drives the LED 23 to notify the short failure of the SSR apparatus 3.

In addition, when the output processing part 36 detects the determination result of the open fault or the short fault of the SSR apparatus 3, it will notify the host PC 100 of the determination result through the communication interface E. FIG.

According to the first embodiment, the temperature control control signal determination unit 33 for determining the on state or the off state of the temperature control control signal, and the heater current determination unit 34 for determining the on state or the off state of the heater current. ), The temperature control signal determination section 33 determines that the temperature control signal is in the on state, and the heater current determination section 34 determines that the heater current is in the off state. Since it is determined that the failure has occurred, an open failure of the SSR device 3 can be recognized.

According to the first embodiment, the SSR apparatus is determined when the temperature control control signal is turned off by the temperature control control signal determiner 33 and when the heater current is turned on by the heater current determiner 34. Since the short fault of (3) is judged, the short fault of the SSR apparatus can be recognized.

According to the first embodiment, the failure notification signal corresponding to the failure determination result of the SSR device 3 is output to the drive circuit 19, and the drive circuit 19 outputs the photocoupler 20 or the output relay. Since the failure determination result is notified and outputted by driving control of 21, the user of the failure detection apparatus 4 can recognize the failure content of the SSR apparatus 3.

In addition, in the first embodiment, the temperature control signal monitoring circuit A monitors the voltage value (control amount) of the temperature control control signal, and the temperature control control signal determination unit 33 keeps the same voltage value for 10 m seconds. Subsequently, if it is determined to be 5v or more, it is determined that the temperature control control signal is on, and if it is determined that the same voltage value is not 5v or more continuously for 10 0 m seconds, the temperature control control signal is judged to be off, The adjustment control signal is set to a current value that changes linearly in the range of 4 kV to 20 kV, the current value of the temperature control control signal is monitored as a control amount, and the dynamic current value is 4 kV in the temperature adjustment control signal determination unit 33. If it is determined to be abnormal, it is judged that the temperature control control signal is in an on state, and if it is determined that the dynamic current value is not more than 4 mA, the temperature control control signal is in an off state. Needless to say, the same effect can be achieved even if it is judged.

In addition, similarly, the current value of the temperature control control signal is monitored as the control amount, and the temperature control control signal determination unit 33 determines whether the current value is 45% or more of the measurement minimum current value, and the current value is 45 degrees of the measurement minimum current value. If it is determined that the temperature adjustment control signal is on or more, it is determined that the temperature control control signal is on, and if it is determined that the dynamic current value is not more than 45% of the measured minimum current value, the same effect can be obtained even by judging that the temperature control control signal is off. .

In the first embodiment, the heater current measurement unit 32 measures the heater current value from the heater current detection circuit B. However, the heater current measurement unit 32 is shown in FIG. 4 or 5. It may be configured by software.

4 is a block diagram showing a schematic configuration inside the heater current measuring unit 32.

The heater current measuring unit 32 shown in FIG. 4 acquires the A / D sampling value every 15 ° with the heater current from the heater current detection circuit B being 360 ° for one cycle, and A for 24 cycles in one cycle. A / D sampling value acquisition unit 42 storing the D / D sampling values in the RAM area 41 and the 24 A / D sampling values stored in the RAM area 41 acquired by the A / D sampling value acquisition unit 42. A base value calculation unit 43 for calculating a base value based on the D sampling value, and a current value calculated by square-averaging the base value for one cycle calculated by the base value calculation unit 43; Has a heater current value conversion section 44 which is converted into a heater current value determined by the heater current determination section 34.

The basic value calculating unit 43 calculates the basic value by applying the 24 A / D sampling values stored in the RAM area 41 to the following expression.

ym = (xm- (xm-12) + (xm-4)-(xm-16)) / 2√3

 xm is the A / D sampling value at the sampling point m

 ym is the default value at sampling point m

 (xm-12) is A / D sampling value at sampling point 12 times before xm

 (xm-4) is A / D sampling value when sampling point 4 times before xm

 (xm-16) is A / D sampling value when sampling point 16 times before xm

The heater current value conversion unit 44 calculates a current value by square-averaging the base value for 24 (one cycle) calculated by the base value calculation unit 43, and converts this current value into a heater current value.

In addition, the A / D sampling value acquisition means of the claim described in the A / D sampling value acquisition portion 42, the basic value calculation means is the basic value calculation portion 43, the heater current value conversion means is the heater current value conversion portion 44 It is equivalent.

According to the heater current measurement part 32 of the software structure shown in FIG. 4, A / D sampling value is acquired every 15 degrees with the heater current from the heater current detection circuit B being 360 degree | times for 1 cycle, and one cycle 24 Based on the 24 A / D sampling values stored in the RAM area 41, the A / D sampling values are stored in the RAM area 41, and the base value is calculated. Since the current value calculated by the square-averaged value is converted to the heater current value determined by the heater current determination unit 34, the heater current value is obtained not digitally, but instead of being affected by noise. The reaction speed which can respond to a change of electric current can be ensured, and as a result, the failure determination precision of the SSR apparatus 3 can be improved.

5 is a block diagram showing a schematic configuration of the heater current measurement unit 32.

The heater current measuring part 32 shown in FIG. 5 acquires an A / D sampling value every 3 degrees by setting the heater current from the heater current detection circuit B to 360 degrees per cycle, and obtains A / D sampling values for 120 cycles per one cycle. The A / D sampling value acquisition unit 52 which stores the D sampling value in the RAM area 51 and the 120 A / D sampling values which are stored in the RAM area 51 are accumulated, and the integrated A / D is accumulated. The heater current value conversion part 53 which converts the electric current value computed by making the sampling value into a square average value as the heater current value determined by the heater current determination part 34 is provided. In addition, the A / D sampling value acquisition means 52 of the Claim description corresponds to the A / D sampling value acquisition part 52, and the heater current value conversion means corresponds to the heater current value conversion part 53. As shown in FIG.

According to the heater current measurement unit 32 of the software configuration shown in FIG. 5, the A / D sampling value is acquired every 3 ° with the heater current from the heater current detection circuit B being 360 ° for one cycle, and 120 cycles for one cycle. The A / D sampling values are stored in the RAM area 51, 120 A / D sampling values stored in the RAM area 51 are accumulated, and the integrated A / D sampling values are squared. Since the calculated current value is converted into the heater current value determined by the heater current determination unit 34, the heater current value is acquired not in analog but digitally, so that the current change in the heater current value is not affected by noise. A corresponding reaction speed can be ensured, and as a result, the failure determination accuracy of the SSR device 3 can be improved.

In addition, although the failure detection apparatus 4 which detects the failure of the SSR apparatus 3 was demonstrated in the said 1st Embodiment, the heater disconnection life before heater disconnection is detected beforehand. The functions that can be done, namely the heater layer short function, are also considered.

So, the failure detection apparatus 4 provided with such a heater layer short function is demonstrated as 2nd Embodiment.

(Embodiment 2)

6 is a block diagram showing a schematic configuration inside the CPU 11 in the failure detection apparatus 4 according to the second embodiment. In addition, the same code | symbol is attached | subjected about the structure same as the fault detection apparatus 4 which concerns on 1st Embodiment, and the description of the overlapping structure and operation | movement is abbreviate | omitted.

The CPU 11 in the failure detection device 4 shown in FIG. 6 uses a temperature control signal monitoring circuit A to determine the current value of the temperature control control signal between the SSR device 3 and the temperature control device 6. A temperature control control signal detection unit 31 that monitors as a control amount and detects the current value, a heater current measurement unit 32 that measures the heater current value through the heater current detection circuit B, and a temperature control control signal detection unit 31. A layer which previously stores an overcurrent value immediately before disconnection of the heater 1 and the overcurrent value immediately before disconnection of the heater 1, as a layer short threshold, for determining the on state or the off state of the temperature control control signal based on the current value detected by The layer short threshold stored in the short threshold value storage section 61 and the layer short threshold storage section 61 is adjusted based on the set current value of the temperature control control signal. It is determined whether or not the threshold value adjusting unit 62 for storing and updating the memory unit 61 and the heater current value measured by the heater current measuring unit 32 have exceeded the layer short threshold stored in the layer short threshold storage unit 61, If it is determined that the heater current value has exceeded the layer short threshold value, the failure notification signal is determined based on the heater layer short determination unit 63 that determines that the heater short is the layer short of the heater 1 and the determination result of the heater layer short determination unit 63. It has an output processor 36 for outputting.

The temperature control signal detection unit 31 sets, for example, the temperature control signal to a current value that changes linearly in the range of 4 kW to 20 kW, and monitors the current value of the temperature control control signal as a control amount.

When it is determined that the current value of the temperature control control signal detected by the temperature control control signal detection unit 31 is 4 mA or more, the temperature control control signal determination unit 33 determines that the temperature control control signal is in an on state, and determines the dynamic current value. Is determined to be not more than 4 dB, it is determined that the temperature regulation control signal is in an off state.

In general, the layer short threshold stored in the layer short threshold storage unit 61 is characterized by the fact that when the disconnection life of the heater 1 approaches, the insulation value inside the heater 1 decreases, thereby increasing the current value flowing through the heater 1. In this case, the overcurrent value immediately before the disconnection of the service life is set. In addition, the layer short threshold value memorize | stored in the layer short threshold memory | storage part 61 can be changed suitably from the operation part which is not shown in figure, or the host PC 100. FIG.

The threshold adjustment unit 62 adjusts the layer short threshold value based on a ratio of 20 mA, which is the set current value of the temperature control control signal, and stores and updates the adjusted layer short threshold value in the layer short threshold storage unit 61. . The threshold adjustment unit 62 stores and updates the optimal layer short threshold value corresponding to the setting of the current temperature control system 10 in the layer short threshold storage unit 61.

The heater layer short determination unit 63 determines that the temperature adjustment control signal is in the ON state in the temperature control control signal determination unit 33, and determines that the heater current value has exceeded the layer short threshold value. Is to execute the judgment operation. In addition, even if it is determined that the heater current has exceeded the layer short threshold, the heater layer short determination unit 63 determines that the temperature control control signal is in the off state by the temperature control control signal determination unit 33. Determination of determining that the layer is short is prohibited.

The output processor 36 outputs a failure notification signal corresponding to the heater layer short to the drive circuit 19 when it is determined that the heater layer short determiner 63 is a layer short of the heater 1.

In addition, the heater current detection means described in the claim is a heater current measurement unit 32, the layer short threshold storage means is a layer short threshold storage unit 61, a layer short threshold determination means and a layer short determination means are a heater layer short determination unit 63 ), The first determination means corresponds to the temperature control control signal determination unit 33, the layer short threshold adjustment means corresponds to the threshold adjustment unit 62, and the notification means corresponds to the output processor 36 and the notification control circuit D. FIG.

Next, operation | movement of the failure detection apparatus 4 in the temperature control system 10 which shows 2nd Embodiment is demonstrated based on FIG. 2 and FIG.

The temperature control control signal monitoring circuit A in the failure detection device 4 monitors the current value of the temperature control control signal transmitted between the SSR device 3 and the temperature control device 6, and the current value is measured using a photocoupler ( 14) The CPU 11 is notified.

When the temperature control signal detection unit 31 in the CPU 11 detects the current value of the temperature control control signal via the photocoupler 14, the temperature control signal detection unit 31 transmits this current value to the temperature control control signal determination unit 33.

The temperature control control signal determination unit 33 determines whether or not the current value of the temperature control control signal is 4 mA or more. When it is determined that the current value is 4 mA, the temperature control control signal determination unit judges that the temperature control control signal is in an on state. The determination result is transmitted to the heater layer short determination unit 63. Further, when it is determined that the current value of the temperature control control signal is not more than 4 mA, the temperature control control signal determining unit 33 determines that the temperature control control signal is in an off state, and the result of this determination is determined by the heater layer short determination unit 63. To send).

In addition, the heater current detection circuit B in the failure detection device 4 digitally converts the heater current detected by the heater current detector 5, and transmits the digitally converted heater current to the CPU 11.

The heater current measurement unit 32 of the CPU 11 measures the heater current value based on the heater current from the heater current detection circuit B, and transmits this heater current value to the heater layer short determination unit 63.

When the heater layer short determination unit 63 detects the determination result that the temperature control control signal is in the on state by the temperature control control signal determination unit 33, the heater current value measured by the heater current measurement unit 32 stores the layer short threshold value. When it determines with the layer short threshold value memorize | stored in the part 61, it determines with the layer short of the heater 1, and notifies the output processing part 36 of this determination result.

When the output processing part 36 detects the determination result of the layer short of the heater 1, the output processing part 36 transmits the failure notification signal corresponding to the layer short of this heater 1 to the drive circuit 19 and the display LED drive circuit 22. Notify. When the drive circuit 19 detects the failure notification signal, the drive circuit 19 drives the photocoupler 20 or the output relay 21 to control the alarm output. In addition, when the display LED drive circuit 22 detects the failure notification signal, it drives the LED 23 to notify the short of the layer of the heater 1. When the output processor 36 detects the determination result of the heater layer short, the output processing unit 36 notifies the host PC 100 of the determination result through the communication interface E.

In addition, the heater layer short determination unit 63 prohibits the comparison determination operation between the heater current value and the layer short threshold value when detecting the determination result that the temperature control control signal is in the off state by the temperature control control signal determination unit 33. do.

According to the second embodiment, when the heater disconnection life approaches, the insulation inside the heater 1 decreases, and attention is paid to the fact that the current flowing in the heater 1 increases immediately before the lifetime, so that the heater 1 disconnects. Having a layer short threshold storage unit 61 which stores in advance an overcurrent value as a layer short threshold in advance, and if it is determined that the temperature control control signal is in an on state, it is determined whether the heater current has exceeded the stored layer short threshold, When it is determined that the heater current has exceeded the layer short threshold, it is determined that the heater is a layer short. Therefore, the heater layer short before the heater is disconnected can be recognized. As a result, it is easy to identify the cause of the failure in the heater disconnection. Can be secured. Moreover, since the heater 1 can be replaced before heater disconnection by grasping the indication before heater disconnection, ie, a layer short, the preventive integrity can be ensured.

In addition, according to the second embodiment, when it is determined that the temperature control control signal is in the off state, the comparison determination operation between the heater current and the layer short threshold value is prohibited, so that the comparison in the off state of the temperature control control signal is performed. The misjudgment of the heater layer short by the determination operation can be reliably prevented.

According to the second embodiment, the layer short threshold stored in the layer short threshold storage unit 61 is adjusted based on the set current value of the temperature control control signal, and the adjusted layer short threshold is stored in the layer short threshold storage unit ( Since the memory is updated to 61), an optimal layer short threshold value corresponding to the setting of the current temperature control system 10 can be set.

In the second embodiment, the heater current measurement unit 32 measures the heater current value from the heater current detection circuit B. However, the heater current measurement unit 32 is shown in FIG. 4 or 5. It may be configured by software.

In the second embodiment, the threshold adjustment unit 62 for adjusting the layer short threshold is provided, but the layer stored in the layer short threshold storage unit 61 without the provision of the threshold adjustment unit 62 is provided. It goes without saying that the layer short of the heater 1 can be determined based on the short threshold and the heater current.

In the second embodiment, when it is determined that the temperature control control signal is in the off state, the comparison determination operation between the heater current and the layer short threshold value is prohibited. However, even if the temperature control control signal is in the off state, the heater current value and It goes without saying that it is also possible to determine that the heater current value is the layer short of the heater 1 when the comparison determination operation with the layer short threshold is performed and the heater current value is determined as the layer short threshold.

Moreover, in the failure detection apparatus 4 which concerns on said 1st Embodiment and 2nd Embodiment, the failure result of the SSR apparatus 3 by the failure detection apparatus 4 using the communication interface E. Moreover, in FIG. Alternatively, although the host PC 100 is notified of the determination result of the layer short of the heater 1, as shown in FIG. 7, the infrared communication interface F for performing infrared communication with another adjacent failure detection device is provided. A system configuration may be provided in which the failure detection device 4 can be notified of the determination result using the infrared communication interface F.

In this case, for example, a request command from the host PC 100 is distributed to each failure detection device 4 via each failure detection device 4, and each failure detection device ( Since the determination result from 4) is notified to the host PC 100, the host PC 100 can collectively manage the failure result of the SSR device 3 and the layer short result of the heater 1.

In addition, in the temperature control system which communicates and connects between the plurality of failure detection apparatuses 4 and the upper level PC 100, an identification number is assigned to each of the failure detection apparatuses 4, and a request command to which the identification number is assigned is given. When the failure detection device 4 receives the request command from the host PC 100, the identification number given to the request command is extracted, and if the extracted identification number is its own identification number, The host PC 100 may be notified to the host PC 100 of the failure of the SSR device 3 by the failure detector 4 or the determination result of the heater layer short. It is possible not only to collectively manage the judgment result, but also to individually extract only the judgment result of the desired failure detection device 4.

In addition, in the said embodiment, although the heater 1 demonstrated the three-phase heater as an example, as shown in FIG. 8, even if it is the single-phase heater 1B, the SSR apparatus 3 and the temperature control apparatus 6 were demonstrated. The open fault or the short fault of the SSR device 3 is determined on the basis of the on / off state of the temperature control control signal between the SSR device 3 and the on / off state of the heater current between the SSR device 3 and the single-phase heater 1B. In addition, it goes without saying that it is also possible to determine a heater layer short based on the heater current and layer short threshold between the SSR apparatus 3 and single-phase heater 1B.

Industrial availability

The failure detection device of the present invention detects a failure (open / short) of the SSR device and generates an alarm distinguished from the heater disconnection, thereby making it easy to determine the cause of the failure of the system in which the failure detection device is assembled. It has an effect, and is useful for the temperature control system which uses heaters, such as an industrial furnace heater, a semiconductor cleaning device, and a plastic molding machine.

According to the failure detecting device of the present invention configured as described above, first determination means for determining whether the temperature control control signal is a control amount of a first predetermined level or more, and whether the heater current is of a second predetermined level or more. A failure of the SSR apparatus, e.g., an open, because it has a second determination means for determining a failure and the failure of the SSR apparatus is determined based on the determination result of the first determination means and the determination result of the second determination means. Failure or short failure can be determined.

According to the failure detecting apparatus of the present invention, it is determined in the first determining means that the temperature control control signal is a control amount equal to or greater than a first predetermined level, and in the second determining means, it is determined that the heater current is not equal to or greater than a second predetermined level. If it is determined that the SSR device has an SSR open failure, the open failure of the SSR device can be determined.

According to the failure detecting device of the present invention, it is determined in the first determining means that the temperature control control signal is not a control amount equal to or greater than a first predetermined level, and further, the second determining means determines that the heater current is equal to or greater than a second predetermined level. If it is determined that the SSR short failure of the SSR device, the short failure of the SSR device can be determined.

According to the failure detection apparatus of the present invention, the determination result of the failure determination means is made to notify the notification means of the notification output, for example, the display output or the speaker output, so that the user of the failure detection apparatus recognizes the determination result of the failure determination means. can do.

According to the failure detecting device of the present invention, the heater current detecting means acquires a predetermined number of A / D sampling values within a predetermined period of the heater current value between the SSR device and the heater, and obtains the acquired number of A / D sampling values. The basic value is calculated based on the D sampling value, and the current value calculated by converting the calculated basic value for the predetermined period into a squared average value is converted into a heater current value determined by the second judging means. By appropriately acquiring the heater current value, the reaction rate of the heater current value to the current change can be secured without being affected by noise, and as a result, the failure determination accuracy of the SSR device can be improved.

According to the failure detecting device of the present invention, the heater current detecting means propagates the heater current value between the SSR device and the heater to obtain a predetermined number of A / D sampling values within a predetermined period, Since the A / D sampling values for the predetermined number are integrated and the current value calculated by the squared-averaged squared A / D sampling value is converted to the heater current value determined by the second judging means, the analog In addition, by digitally acquiring the heater current value, the reaction rate of the heater current value to the current change can be secured without being affected by noise, and as a result, the failure determination accuracy of the SSR device can be improved.

According to the failure detecting apparatus of the present invention, there is provided a wireless communication means for wirelessly connecting a host apparatus and another failure detecting apparatus to a wireless connection, for example, infrared light, and through this wireless communication means, the determination result of the failure determining means is determined. Since transmission and reception are performed between the host device and the other fault detection device, the host device or the other fault detection device can recognize the failure result of the failure detection device, that is, the failure of the SSR device, while saving wiring. . As a result, failure of the SSR device can be recognized throughout the system.

In addition, according to the fault detection apparatus of the present invention configured as described above, when the disconnection life of the heater approaches, the insulation inside the heater decreases, and attention is paid to the fact that the current flowing through the heater increases immediately before the life of the heater is disconnected. And a layer short threshold storage means for storing in advance a current overcurrent value as a layer short threshold value. When the heater current is detected, it is determined whether the heater current exceeds a stored layer short, and the heater current is the layer short. When it is determined that the threshold value is exceeded, it is determined that the heater is a layer short, so that the layer short before the heater is disconnected, and as a result, it is easy to grasp the cause of the failure in the heater disconnection, thereby ensuring maintenance. have. In addition, since it is possible to replace the heater before the heater disconnection by grasping the symptoms before the heater disconnection, that is, the layer short, the preventive maintenance can be ensured.

According to the failure detecting apparatus of the present invention, the apparatus has first determining means for determining whether the temperature control control signal is a control amount of a first predetermined level or more, wherein the temperature control control signal is determined to be a control amount of a first predetermined level or more, In addition, when it is determined that the heater current exceeds the layer short threshold, it is determined that the heater is a layer short, and even if it is determined that the heater current exceeds the layer short threshold, the temperature control control signal is first predetermined. If it is determined that the control amount is not equal to the level or higher, the determination operation for determining that the heater is a layer short is prohibited. It can prevent.

According to the fault detection apparatus of the present invention, the layer short threshold stored in the layer short threshold storage means is adjusted based on a set current value of the temperature control control signal, and the adjusted layer short threshold is stored in the layer short threshold. Since the memory is updated by the means, even if there is a change in the set current value of the temperature control control signal, the layer short threshold value corresponding to the set current value can be automatically updated.

According to the failure detecting apparatus of the present invention, when it is determined that the heater is a layer short, the result of the determination is provided with a notification means for notifying the output of a display, for example, a display output or a speaker. You can recognize the layer short of.

According to the failure detecting device of the present invention, the heater current detecting means acquires a predetermined number of A / D sampling values within a predetermined period from the heater current value between the SSR device and the heater, and acquires the predetermined number of A's. The base value is calculated based on the / D sampling value, and the current value calculated by making the calculated base value for the predetermined period is the squared average value is converted into the heater current value determined by the layer short threshold value determining means. However, by digitally acquiring the heater current value, the reaction rate of the heater current value to the current change can be ensured without being influenced by noise, and as a result, the determination accuracy of the layer short immediately before the heater disconnection can be improved.

According to the failure detecting device of the present invention, the heater current detecting means propagates and rectifies a heater current value between the SSR device and the heater to obtain a predetermined number of A / D sampling values within a predetermined period, Since the current value calculated by integrating the A / D sampling value of the A / D sampling value and the squared average value of the integrated A / D sampling value is converted into the heater current value determined by the layer short threshold value determination means, the digital value is not analogous. By acquiring the heater current value, the reaction rate to the current change of a heater current value can be ensured without being influenced by noise, and as a result, the determination precision of the layer short immediately before heater disconnection can be improved.

According to the failure detecting apparatus of the present invention, there is provided a wireless communication means for wirelessly connecting the host apparatus and other failure detection apparatuses, for example, infrared light, and through the wireless communication means, the determination result of the layer short determination means is obtained. Since the transmission and reception is performed between the host device and the other fault detection device, the host device or the other fault detection device can recognize the result of the determination of the fault detection device, that is, the layer short before the heater is disconnected, while saving wiring. . As a result, water retention and preventive maintenance regarding the heater of the whole system can be secured.

Claims (14)

A heater to be controlled, a power supply unit supplying electric power to the heater, an SSR device disposed between these heaters and the power supply unit, and adjusting an amount of electric power supplied from the power supply unit to the heater in accordance with a temperature control control signal; In order to monitor the temperature and set the temperature of the heater to a target temperature based on the monitoring result, a temperature control system having a temperature adjusting device for outputting the temperature control control signal is connected, and a failure of the SSR device is detected. As a failure detection device to Heater current detection means for detecting a heater current between the SSR device and the heater; First judging means for judging whether or not the temperature adjustment control signal is a control amount of a first predetermined level or more; Second judging means for judging whether or not the heater current detected by the heater current detecting means is equal to or greater than a second predetermined level; And a failure determination means for determining a failure of the SSR apparatus based on the determination result of the first determination means and the determination result of the second determination means, The failure determining means, If it is determined in the first determining means that the temperature control control signal is a control amount equal to or greater than a first predetermined level, and if it is determined in the second determining means that the heater current is not equal to or greater than a second predetermined level, the SSR open fault of the SSR apparatus. Judging by The failure determining means, If it is determined by the first determining means that the temperature control control signal is not a control amount equal to or greater than a first predetermined level, and when it is determined by the second determining means that the heater current is equal to or greater than a second predetermined level, an SSR short failure of the SSR apparatus is performed. And a failure detection device, characterized in that. delete delete The method of claim 1, And a notification means for notifying and outputting the determination result of the failure determination means. The method of claim 1, The heater current detection means, A / D sampling value acquiring means for acquiring a predetermined number of A / D sampling values within a predetermined period of the heater current value between the SSR apparatus and the heater; Basic value calculating means for calculating a basic value based on a predetermined number of A / D sampling values acquired by said A / D sampling value obtaining means; And a heater current value converting means for converting the current value calculated by converting the basic value of the predetermined period calculated by the basic value calculating means into a squared average value as the heater current value determined by the second determining means. The method of claim 1, The heater current detection means, A / D sampling value acquisition means for full-wave rectifying the heater current value between the SSR apparatus and the heater to obtain a predetermined number of A / D sampling values within a predetermined period; A heater current value converting means for converting the current value calculated by integrating this predetermined number of A / D sampling values and converting the integrated A / D sampling values into a square average value, as the heater current value determined by the second determining means; Failure detection apparatus characterized by having. The method of claim 1, And wireless communication means for wirelessly connecting to a higher level device and another failure detection device, wherein the wireless communication means transmits / receives the determination result of the failure determination means with the higher level device or the other failure detection device. Fault detection device. delete A heater to be controlled, a power supply unit supplying electric power to the heater, an SSR device disposed between these heaters and the power supply unit, and adjusting an amount of electric power supplied from the power supply unit to the heater in accordance with a temperature control control signal; In order to monitor the temperature and to set the temperature of the heater to a target temperature based on the monitoring result, a temperature control system having a temperature adjusting device for outputting the temperature control control signal is connected to detect a failure of the heater. As a fault detection device, Heater current detection means for detecting a heater current between the SSR device and the heater; Layer short threshold memory means for storing an overcurrent value immediately before disconnection of the heater as a layer short threshold value; Layer short threshold determination means for determining whether or not the heater current exceeds the layer short threshold stored in the layer short threshold storage means when the heater current is detected by the heater current detecting means; If it is determined in the layer short threshold value determining means that the heater current has exceeded the layer short threshold value, the layer short determination means has a layer short determination means for determining that it is a layer short of the heater, And a first judging means for judging whether or not the temperature adjustment control signal is a control amount of a first predetermined level or more, The layer short determination means, If it is determined in the first determining means that the temperature control control signal is a control amount equal to or greater than a first predetermined level, and if it is determined in the layer short threshold determining means that the heater current exceeds the layer short threshold, it is called a layer short of the heater. Execute the judgment operation to judge, If it is determined in the layer short threshold value determining means that the heater current has exceeded the layer short threshold value, and the first judgment means determines that the temperature control control signal is not a control amount equal to or greater than a first predetermined level, the layer of the heater. The fault detection apparatus characterized by prohibiting the judgment operation judged as a short. The method of claim 9, The layer short threshold adjustment which adjusts the said layer short threshold stored in the said layer short threshold storage means based on the setting current value of the said temperature control control signal, and memory-updates this adjusted layer short threshold value to the said layer short threshold storage means. Means for detecting a failure. A heater to be controlled, a power supply unit supplying electric power to the heater, an SSR device disposed between these heaters and the power supply unit, and adjusting an amount of electric power supplied from the power supply unit to the heater in accordance with a temperature control control signal; In order to monitor the temperature and to set the temperature of the heater to a target temperature based on the monitoring result, a temperature control system having a temperature adjusting device for outputting the temperature control control signal is connected to detect a failure of the heater. As a fault detection device, Heater current detection means for detecting a heater current between the SSR device and the heater; Layer short threshold memory means for storing an overcurrent value immediately before disconnection of the heater as a layer short threshold value; Layer short threshold determination means for determining whether or not the heater current exceeds the layer short threshold stored in the layer short threshold storage means when the heater current is detected by the heater current detecting means; If it is determined in the layer short threshold value determining means that the heater current has exceeded the layer short threshold value, the layer short determination means has a layer short determination means for determining that it is a layer short of the heater, And a first judging means for judging whether or not the temperature adjustment control signal is a control amount of a first predetermined level or more, The layer short determination means, If it is determined in the first determining means that the temperature control control signal is a control amount equal to or greater than a first predetermined level, and if it is determined in the layer short threshold determining means that the heater current exceeds the layer short threshold, it is called a layer short of the heater. Execute the judgment operation to judge, And a notification means for notifying and outputting this determination result, when the layer short determination means determines that the heater is a layer short. A heater to be controlled, a power supply unit supplying electric power to the heater, an SSR device disposed between these heaters and the power supply unit, and adjusting an amount of electric power supplied from the power supply unit to the heater in accordance with a temperature control control signal; In order to monitor the temperature and to set the temperature of the heater to a target temperature based on the monitoring result, a temperature control system having a temperature adjusting device for outputting the temperature control control signal is connected to detect a failure of the heater. As a fault detection device, Heater current detection means for detecting a heater current between the SSR device and the heater; Layer short threshold memory means for storing an overcurrent value immediately before disconnection of the heater as a layer short threshold value; Layer short threshold determination means for determining whether or not the heater current exceeds the layer short threshold stored in the layer short threshold storage means when the heater current is detected by the heater current detecting means; If it is determined in the layer short threshold value determining means that the heater current has exceeded the layer short threshold value, the layer short determination means has a layer short determination means for determining that it is a layer short of the heater, And a first judging means for judging whether or not the temperature adjustment control signal is a control amount of a first predetermined level or more, The layer short determination means, If it is determined in the first determining means that the temperature control control signal is a control amount equal to or greater than a first predetermined level, and if it is determined in the layer short threshold determining means that the heater current exceeds the layer short threshold, it is called a layer short of the heater. Execute the judgment operation to judge, The heater current detection means, A / D sampling value acquiring means for acquiring a predetermined number of A / D sampling values within a predetermined period of the heater current value between the SSR apparatus and the heater; Basic value calculating means for calculating a basic value based on a predetermined number of A / D sampling values acquired by said A / D sampling value obtaining means; And a heater current value converting means for converting the current value calculated by converting the base value for the predetermined period calculated by the basic value calculating means into a heater current value determined by the layer short threshold value determining means. Device. A heater to be controlled, a power supply unit supplying electric power to the heater, an SSR device disposed between these heaters and the power supply unit, and adjusting an amount of electric power supplied from the power supply unit to the heater in accordance with a temperature control control signal; In order to monitor the temperature and to set the temperature of the heater to a target temperature based on the monitoring result, a temperature control system having a temperature adjusting device for outputting the temperature control control signal is connected to detect a failure of the heater. As a fault detection device, Heater current detection means for detecting a heater current between the SSR device and the heater; Layer short threshold memory means for storing an overcurrent value immediately before disconnection of the heater as a layer short threshold value; Layer short threshold determination means for determining whether or not the heater current exceeds the layer short threshold stored in the layer short threshold storage means when the heater current is detected by the heater current detecting means; If it is determined in the layer short threshold value determining means that the heater current has exceeded the layer short threshold value, the layer short determination means has a layer short determination means for determining that it is a layer short of the heater, And a first judging means for judging whether or not the temperature adjustment control signal is a control amount of a first predetermined level or more, The layer short determination means, If it is determined in the first determining means that the temperature control control signal is a control amount equal to or greater than a first predetermined level, and if it is determined in the layer short threshold determining means that the heater current exceeds the layer short threshold, it is called a layer short of the heater. Execute the judgment operation to judge, The heater current detection means, A / D sampling acquiring means for full-wave rectifying the heater current value between the SSR apparatus and the heater to acquire a predetermined number of A / D sampling values within a predetermined period; Heater current value conversion which converts the current value calculated by integrating this predetermined number of A / D sampling values, and averages this integrated A / D sampling value by the squared average value, as the heater current value determined by the layer short threshold determination means. Means for detecting a failure. A heater to be controlled, a power supply unit supplying electric power to the heater, an SSR device disposed between these heaters and the power supply unit, and adjusting an amount of electric power supplied from the power supply unit to the heater in accordance with a temperature control control signal; In order to monitor the temperature and to set the temperature of the heater to a target temperature based on the monitoring result, a temperature control system having a temperature adjusting device for outputting the temperature control control signal is connected to detect a failure of the heater. As a fault detection device, Heater current detection means for detecting a heater current between the SSR device and the heater; Layer short threshold memory means for storing an overcurrent value immediately before disconnection of the heater as a layer short threshold value; Layer short threshold determination means for determining whether or not the heater current exceeds the layer short threshold stored in the layer short threshold storage means when the heater current is detected by the heater current detecting means; If it is determined in the layer short threshold value determining means that the heater current has exceeded the layer short threshold value, the layer short determination means has a layer short determination means for determining that it is a layer short of the heater, And a first judging means for judging whether or not the temperature adjustment control signal is a control amount of a first predetermined level or more, The layer short determination means, If it is determined in the first determining means that the temperature control control signal is a control amount equal to or greater than a first predetermined level, and if it is determined in the layer short threshold determining means that the heater current exceeds the layer short threshold, it is called a layer short of the heater. Execute the judgment operation to judge, And a wireless communication means for wirelessly connecting to a higher level device and another failure detecting device, wherein the result of the determination of the layer short determining means is transmitted and received between the higher level device and the other failure detecting device. Failure detection device characterized in that.

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