阅读说明：本技术 漏液检测装置 (Liquid leakage detection device ) 是由 根本英次 牧野兼三 荒木宏 堀淳二 泽良次 于 2019-06-13 设计创作，主要内容包括：本发明提供一种漏液检测装置,其具备：漏液检测部(70),其连接有一个漏液检测单元(U)或串联地连接有多个漏液检测单元(U),漏液检测单元(U)包括：漏液检测带(60),其包括一对导电线(61、62),当漏液接触时,电流流过该漏液检测带；以及节点(ND),其与漏液检测带(60)连接,具有在施加电压达到规定的电压值时导通的恒压元件(D)；电源(81)；电流传感器(82)；以及判定部(90),其根据由电流传感器(82)检测出的输入电流值来判定漏液的发生,漏液检测部(70)具有漏液检测单元(U)根据输入电压值而导通的特性,判定部(90)根据由电流传感器(82)检测出的输入电流值来判定漏液的发生。(The present invention provides a liquid leakage detection device, which comprises: a liquid leakage detection unit (70) connected with one liquid leakage detection unit (U) or connected with a plurality of liquid leakage detection units (U) in series, the liquid leakage detection unit (U) including: a leakage detection zone (60) including a pair of conductive wires (61, 62) through which a current flows when leakage is in contact; and a Node (ND) connected to the leak detection band (60) and having a constant voltage element (D) that is turned on when the applied voltage reaches a predetermined voltage value; a power supply (81); a current sensor (82); and a determination unit (90) that determines the occurrence of liquid leakage based on the input current value detected by the current sensor (82), wherein the liquid leakage detection unit (70) has a characteristic that the liquid leakage detection means (U) is turned on based on the input voltage value, and the determination unit (90) determines the occurrence of liquid leakage based on the input current value detected by the current sensor (82).)

1. A liquid leakage detection device is characterized in that,

the liquid leakage detection device is provided with:

a liquid leakage detection section connected with one liquid leakage detection unit or connected with a plurality of liquid leakage detection units in series, the liquid leakage detection unit including: a leakage detection zone including a pair of conductive wires through which a current flows when a leakage contacts between the conductive wires; and a node connected to the leakage detection band and having a constant voltage element that is turned on when an applied voltage reaches a predetermined voltage value;

a power supply connected to a start end of the leakage detecting unit;

a current detection unit that detects an input current value at the start end of the leakage detection unit; and

a determination unit that determines occurrence of liquid leakage based on the input current value detected by the current detection unit,

the leakage detecting section has a characteristic that each of the leakage detecting units is turned on in accordance with an input voltage value,

the determination unit determines occurrence of liquid leakage based on the input current value detected by the current detection unit.

2. The leak detection apparatus according to claim 1,

the node of the leakage detecting unit includes:

a pair of start-end side terminals;

a pair of terminal ends connected to the pair of conductive wires of the leakage detecting unit, respectively; and

a pair of connection lines connecting the start-side terminal and the end-side terminal in parallel,

the constant voltage element is configured to intervene in either one or both connection lines.

3. The leak detection apparatus according to claim 1 or 2,

the power supply applies a standby voltage having a predetermined voltage value to the starting end of the leakage detecting unit,

the determination unit determines whether or not liquid leakage has occurred in at least one of the liquid leakage detection units by comparing the input current value detected by the current detection unit with a predetermined threshold value.

4. The leak detection apparatus according to claim 1 or 2,

the power supply outputs a voltage corresponding to the voltage command value input from the determination unit,

the determination unit varies the input voltage value of the leakage detection unit before and after a standby voltage value by varying the voltage command value output to the power supply before and after the standby voltage value,

whether or not leakage has occurred in at least one of the leakage detection units is determined by comparing a conductance or a resistance value calculated from the voltage command value or the input voltage value and the input current value detected by the current detection unit with a predetermined threshold value.

5. The leak detection apparatus according to claim 1 or 2,

the power supply outputs a voltage corresponding to the voltage command value input from the determination unit,

the determination unit sweeps the voltage command value output to the power supply to sweep the input voltage value of the leak detection unit, and turns on the leak detection units in the order of connection with the start end,

whether or not leakage occurs in at least one of the leakage detection units in the on state is determined by comparing a conductance or a resistance value calculated from the voltage command value or the input voltage value and the input current value detected by the current detection unit with a predetermined threshold value.

6. The leak detection apparatus according to claim 1 or 2,

the power supply outputs a voltage corresponding to the voltage command value input from the determination unit,

the determination unit sweeps the voltage command value output to the power supply to sweep the input voltage value of the leak detection unit, and turns on the leak detection units in the order of connection with the start end,

calculating the conductance of one of the leak detection units using the input current value detected by the current detection unit when a range from the start end of the leak detection unit to one of the leak detection units is brought into an on state and the input current value detected by the current detection unit when a range other than one of the leak detection units in the range is brought into an on state,

and a leakage detecting means for determining that leakage has occurred by comparing the calculated conductance with a predetermined threshold value.

7. The leak detection apparatus according to claim 1 or 2,

the leakage detecting section has a disconnection detecting element connected between the conductive wires of the leakage detecting unit,

the power supply applies an input voltage of a predetermined voltage value to the starting end of the leakage detecting section,

the determination unit detects whether or not the leak detection unit is broken by comparing the input current value detected by the current detection unit with a predetermined threshold value.

8. The leak detection apparatus according to claim 1 or 2,

the leakage detecting section has a disconnection detecting element connected between the conductive wires of the leakage detecting unit,

the power supply outputs a voltage corresponding to the voltage command value input from the determination unit,

the determination unit sweeps the voltage command value output to the power supply to sweep the input voltage value of the leak detection unit, and turns on the leak detection units in the order of connection with the start end,

calculating the conductance of one of the leak detection units using the input current value detected by the current detection unit when a range from the start end of the leak detection unit to one of the leak detection units is brought into an on state and the input current value detected by the current detection unit when a range other than one of the leak detection units in the range is brought into an on state,

and a step of comparing the calculated conductance with a predetermined threshold value to determine the leakage detecting means in which the disconnection has occurred.

9. A liquid leakage detection device is characterized in that,

the liquid leakage detection device is provided with:

a liquid leakage detection section connected with one liquid leakage detection unit or connected with a plurality of liquid leakage detection units in series, the liquid leakage detection unit including: a leakage detection zone including a pair of conductive wires through which a current flows when a leakage contacts between the conductive wires; and a node connected to the leak detection tape and having a constant voltage element that is turned on when an applied voltage reaches a predetermined voltage value, wherein the leak detection unit has a resistor connected between the conductive wires at the ends thereof;

a power supply connected to a start end of the leakage detecting unit;

a voltage detection unit that detects an input voltage value at the start end of the leakage detection unit; and

a determination unit that determines the occurrence of liquid leakage based on the input voltage value detected by the voltage detection unit,

the leakage detection section has a characteristic that each of the leakage detection units is turned on in accordance with the input voltage value,

the determination unit determines occurrence of liquid leakage based on the input voltage value detected by the voltage detection unit.

10. The leak detection apparatus according to claim 9,

the node of the leakage detecting unit includes:

a pair of start-end side terminals;

a pair of terminal ends connected to the pair of conductive wires of the leakage detecting unit, respectively; and

a pair of connection lines connecting the start-side terminal and the end-side terminal in parallel,

the constant voltage element is configured to intervene in either one or both connection lines.

11. The leak detection apparatus according to claim 9 or 10,

the power supply inputs a standby current of a predetermined current value to the leakage detecting section,

the determination unit determines the occurrence of liquid leakage by comparing the input voltage value detected by the voltage detection unit with a predetermined threshold value.

12. The leak detection apparatus according to claim 9 or 10,

the power supply outputs a current corresponding to the current command value input from the determination unit,

the determination unit varies the current command value output to the power supply before and after a standby current value to vary the input current value of the leakage detection unit before and after the standby current value,

whether or not leakage has occurred at least one of the leakage detection units is determined by comparing a conductance or a resistance value calculated from the current command value or the input current value and the input voltage value detected by the voltage detection unit with a predetermined threshold value.

13. The leak detection apparatus according to claim 9 or 10,

the power supply outputs a current corresponding to the current command value input from the determination unit,

the determination unit sweeps the current command value output to the power supply to sweep the input current value of the leakage detection unit, and turns on the leakage detection units in the order of connection with the start end,

whether or not liquid leakage occurs in at least one of the liquid leakage detection units in the on state is determined by comparing a conductance or a resistance value calculated from the current command value or the input current value and the input voltage value detected by the voltage detection unit with a predetermined threshold value.

14. The leak detection apparatus according to claim 9 or 10,

the power supply outputs a current corresponding to the current command value input from the determination unit,

the determination unit sweeps the current command value output to the power supply to sweep the input current value of the leakage detection unit, and turns on the leakage detection units in the order of connection with the start end,

calculating the conductance of one of the leak detection units using the input voltage value detected by the voltage detection unit when a range from the start end of the leak detection unit to one of the leak detection units is brought into an on state and the input voltage value detected by the voltage detection unit when a range other than one of the leak detection units in the range is brought into an on state,

and a leakage detecting means for determining that leakage has occurred by comparing the calculated conductance with a predetermined threshold value.

15. The leak detection apparatus according to claim 9 or 10,

the leakage detecting section has a disconnection detecting element connected between the conductive wires of the leakage detecting unit,

the power supply inputs an input current of a predetermined current value to the leakage detecting section,

the determination unit detects whether or not the disconnection has occurred in the leakage detection unit by comparing the input voltage value detected by the voltage detection unit with a predetermined threshold value.

16. The leak detection apparatus according to claim 9 or 10,

the leakage detecting section has a disconnection detecting element connected between the conductive wires of the leakage detecting unit,

the power supply outputs a current corresponding to the current command value input from the determination unit,

the determination unit sweeps the current command value output to the power supply to sweep the input current value of the leakage detection unit, and turns on the leakage detection units in the order of connection with the start end,

calculating the conductance of one of the leak detection units using the input voltage value detected by the voltage detection unit when a range from the start end of the leak detection unit to one of the leak detection units is brought into an on state and the input voltage value detected by the voltage detection unit when a range other than one of the leak detection units in the range is brought into an on state,

and a step of comparing the calculated conductance with a predetermined threshold value to determine the leakage detecting means in which the disconnection has occurred.

17. The leak detection apparatus according to any one of claims 1, 2, 9, and 10,

the opening voltage value of the constant voltage element in the positive direction of the leakage detection unit is different from the opening voltage value in the negative direction,

the power supply is an alternating current power supply,

the determination unit makes the amount of electric charge applied in the positive direction and the amount of electric charge applied in the negative direction of the alternating current output from the power supply equal to each other.

18. The leak detection apparatus according to any one of claims 1, 2, 9, and 10,

the leak detection device includes a start-end-side leak detection zone including a pair of the conductive wires, through which a current flows when a leak contacts between the conductive wires,

the power supply is connected to the start end of the leakage detecting unit via the start end side leakage detecting belt.

Technical Field

The present invention relates to a structure of a liquid leakage detection device, and more particularly to a structure of a liquid leakage detection device using a constant voltage element.

Background

As a method of detecting the occurrence of liquid leakage from an air conditioner or the like, the following methods are used: a current is passed through a leak detection tape in which two lead wires are arranged in parallel in a non-conductive state, and a leak is detected by detecting a short circuit when the leak enters between the two lead wires.

However, in such a leak detection method, even if the leak can be detected, the leak occurrence portion cannot be detected. Therefore, a liquid leakage position detector has been proposed which uses a detection belt in which a detection sensor in which a plurality of resistance elements are connected in series via a lead wire and a lead wire arranged in parallel with the detection sensor are connected to each other via a terminating resistor, and detects a liquid leakage occurrence portion by a change in the conduction resistance of the detection belt due to liquid leakage (see, for example, japanese unexamined patent publication No. 63-101842).

Further, a leakage detector has been proposed in which two sensor wires are arranged in parallel, a constant current power supply is connected to each of both ends of the sensor wires, and a leakage occurrence portion is detected from a voltage difference between both ends of the sensor wires (for example, japanese patent application laid-open No. h 3-9256).

Disclosure of Invention

However, the resistance value is often detected by detecting a current value when a minute voltage is applied to the resistor. The detection sensor of the leakage detector described in japanese unexamined patent publication No. 63-101842 is formed by connecting a plurality of fixed resistors in series, and when leakage occurs at a position close to a power supply, a change in a detected current value is large, but when leakage occurs at a position far from the power supply, a change in the detected current value is small. The flow resistance of water when liquid leakage occurs is not always constant, and the detected current value also changes according to the change in the flow resistance. When liquid leakage occurs at a position distant from the power supply, the change in the detection current value is lost by the change in the current value due to the change in the flow resistance of water, and detection of the liquid leakage occurrence portion may become difficult.

Further, in the leak detector described in japanese patent application laid-open No. 3-9256, a constant current power supply needs to be connected to both ends of the sensor wire, and a voltage difference is detected by a differential amplifier, which makes the configuration complicated.

Therefore, an object of the present invention is to improve the reliability of the leakage determination with a simple configuration.

Means for solving the problems

The liquid leakage detection device of the present invention is characterized by comprising: a liquid leakage detection section connected with one liquid leakage detection unit or connected with a plurality of liquid leakage detection units in series, the liquid leakage detection unit including: a leakage detection zone including a pair of conductive wires through which a current flows when a leakage contacts between the conductive wires; and a node connected to the leakage detection band and having a constant voltage element that is turned on when an applied voltage reaches a predetermined voltage value; a power supply connected to a start end of the leakage detecting unit; a current detection unit that detects an input current value at the start end of the leakage detection unit; and a determination unit that determines occurrence of a liquid leak based on the input current value detected by the current detection unit, the liquid leak detection unit having a characteristic that each of the liquid leak detection units is turned on based on an input voltage value, and the determination unit determining occurrence of a liquid leak based on the input current value detected by the current detection unit.

Thus, the reliability of the liquid leakage determination can be improved with a simple configuration.

In the liquid leakage detection apparatus of the present invention, the node of the liquid leakage detection unit may include: a pair of start-end side terminals; a pair of terminal ends connected to the pair of conductive wires of the leakage detecting unit, respectively; and a pair of connection lines connecting the start-side terminal and the end-side terminal in parallel, wherein the constant voltage element is disposed so as to intervene in one or both of the connection lines.

In this way, the arrangement of the constant voltage elements of the nodes can be variously changed according to the liquid to be detected, and therefore, leakage detection according to the liquid to be detected can be performed.

In the leakage detection device according to the present invention, the power supply may apply a standby voltage having a predetermined voltage value to the start end of the leakage detection unit, and the determination unit may determine whether or not leakage has occurred in at least one of the leakage detection units by comparing the input current value detected by the current detection unit with a predetermined threshold value.

In this way, the occurrence of liquid leakage can be determined in a short time by a simple configuration in which the standby voltage value is set to a predetermined voltage value.

In the leakage detection device according to the present invention, the power supply may output a voltage corresponding to a voltage command value input from the determination unit, the determination unit may change the voltage command value output to the power supply before and after a standby voltage value to change the input voltage value of the leakage detection unit before and after the standby voltage value, and may determine whether or not leakage has occurred in at least one of the leakage detection units by comparing a conductance or a resistance value calculated based on the voltage command value or the input voltage value and the input current value detected by the current detection unit with a predetermined threshold value.

In this way, since the determination of the leakage is performed by calculating the conductance or the resistance value by varying the input voltage value of the leakage detecting unit before and after the standby voltage value, the determination of the leakage can be performed by a physical quantity different from the input current value.

In the leakage detection device according to the present invention, the power supply may output a voltage corresponding to a voltage command value input from the determination unit, and the determination unit may sweep the input voltage value of the leakage detection unit by sweeping the voltage command value output to the power supply, turn on each of the leakage detection units in order of connection with the start end, and compare a conductance or a resistance value calculated from the voltage command value or the input voltage value and the input current value detected by the current detection unit with a predetermined threshold value, and determine whether or not leakage has occurred in at least one of the leakage detection units in an on state.

Since the determination of the leakage is performed by calculating the conductance or the resistance value by sweeping the input voltage value of the leakage detection unit in this way, the determination of the leakage can be performed by a physical quantity different from the input current value.

In the leakage detection device of the present invention, the power supply may output a voltage corresponding to a voltage command value input from the determination unit, the determination unit may sweep the voltage command value output to the power supply to sweep the input voltage value of the leakage detection unit, turn on the leakage detection units in order of connection with the start end, calculate the conductance of one of the leakage detection units using the input current value detected by the current detection unit when a range from the start end of the leakage detection unit to one of the leakage detection units is brought into an on state and the input current value detected by the current detection unit when a range other than one of the leakage detection units in the range is brought into an on state, and compare the calculated conductance with a predetermined threshold value, and the leakage detection unit is used for determining the occurrence of leakage.

In this way, the input voltage value of the leakage detecting unit is swept to turn on the leakage detecting means in the order of connection to the start end, the conductance of each leakage detecting means is calculated, and the calculated conductance is compared with a predetermined threshold value, so that the leakage detecting means in which leakage has occurred can be specified. This can improve the detection reliability of the liquid leakage portion with a simple configuration.

In the leakage detection device according to the present invention, the leakage detection unit may include a disconnection detection element connected between the conductive wires of the leakage detection means, the power supply may apply an input voltage of a predetermined voltage value to the start end of the leakage detection unit, and the determination unit may detect whether or not a disconnection has occurred in the leakage detection unit by comparing the input current value detected by the current detection unit with a predetermined threshold value.

Thus, the disconnection of the leakage detecting section can be detected with a simple configuration.

In the leak detection device according to the present invention, the leak detection unit may include a disconnection detection element connected between the conductive wires of the leak detection unit, the power supply may output a voltage corresponding to a voltage command value input from the determination unit, the determination unit may sweep the voltage command value output to the power supply to sweep the input voltage value of the leak detection unit, the leak detection units may be turned on in order of being connected to the start end, the input current value detected by the current detection unit when a range from the start end of the leak detection unit to one of the leak detection units is turned on, and the input current value detected by the current detection unit when a range other than one of the leak detection units in the range is turned on may be used, and calculating the conductance of one of the leak detection units, and comparing the calculated conductance with a predetermined threshold value to determine the leak detection unit in which the disconnection has occurred.

Thus, the leakage detecting means in which the disconnection has occurred can be specified with a simple configuration.

The liquid leakage detection device of the present invention is characterized by comprising: a liquid leakage detection section connected with one liquid leakage detection unit or connected with a plurality of liquid leakage detection units in series, the liquid leakage detection unit including: a leakage detection zone including a pair of conductive wires through which a current flows when a leakage contacts between the conductive wires; and a node connected to the leak detection tape and having a constant voltage element that is turned on when an applied voltage reaches a predetermined voltage value, wherein the leak detection unit has a resistor connected between the conductive wires at the ends thereof; a power supply connected to a start end of the leakage detecting unit; a voltage detection unit that detects an input voltage value at the start end of the leakage detection unit; and a determination unit that determines occurrence of liquid leakage based on the input voltage value detected by the voltage detection unit, the liquid leakage detection unit having a characteristic that each of the liquid leakage detection units is turned on based on the input voltage value, and the determination unit determining occurrence of liquid leakage based on the input voltage value detected by the voltage detection unit.

Thus, the reliability of the liquid leakage determination can be improved with a simple configuration.

In the liquid leakage detection device according to the present invention, the power supply may input a standby current having a predetermined current value to the liquid leakage detection unit, and the determination unit may determine the occurrence of liquid leakage by comparing the input voltage value detected by the voltage detection unit with a predetermined threshold value.

In this way, the occurrence of liquid leakage can be determined in a short time by a simple configuration in which the standby current value is set to a predetermined current value.

In the leakage detection device according to the present invention, the power supply may output a current corresponding to a current command value input from the determination unit, the determination unit may change the current command value output to the power supply before and after a standby current value, so that an input current value of the leakage detection unit changes before and after the standby current value, and a determination may be made as to whether or not leakage has occurred in at least one of the leakage detection units by comparing a conductance or a resistance value calculated based on the current command value or the input current value and the input voltage value detected by the voltage detection unit with a predetermined threshold value.

In this way, since the determination of the leakage is performed by calculating the conductance or the resistance value by varying the input current value of the leakage detecting unit before and after the standby current value, the determination of the leakage can be performed by a physical quantity different from the input voltage value.

In the leakage detection device according to the present invention, the power supply may output a current corresponding to a current command value input from the determination unit, and the determination unit may sweep the current command value output to the power supply to sweep an input current value of the leakage detection unit, turn on the respective leakage detection units in order of connection with the start end, and compare a conductance or a resistance value calculated from the current command value or the input current value and the input voltage value detected by the voltage detection unit with a predetermined threshold value to determine whether or not leakage has occurred in at least one of the leakage detection units in an on state.

Since the determination of the leakage is performed by calculating the conductance or the resistance value by sweeping the input current value of the leakage detection unit in this way, the determination of the leakage can be performed by a physical quantity different from the input voltage value.

In the leakage detection device of the present invention, the power supply may output a current corresponding to a current command value input from the determination unit, the determination unit may sweep the current command value output to the power supply to sweep an input current value of the leakage detection unit, turn on the leakage detection units in order of connection with the start end, calculate a conductance of one of the leakage detection units using the input voltage value detected by the voltage detection unit when a range from the start end of the leakage detection unit to one of the leakage detection units is turned on and the input voltage value detected by the voltage detection unit when a range other than one of the leakage detection units in the range is turned on, and compare the calculated conductance with a predetermined threshold value, and the leakage detection unit is used for determining the occurrence of leakage.

In this way, the input current value of the leakage detecting unit is swept to turn on the leakage detecting means in the order of connection to the start end, the conductance of each leakage detecting means is calculated, and the calculated conductance is compared with a predetermined threshold value, so that the leakage detecting means in which leakage has occurred can be specified. This can improve the detection reliability of the liquid leakage portion with a simple configuration.

In the leakage detection device according to the present invention, the leakage detection unit may include a disconnection detection element connected between the conductive wires of the leakage detection means, the power supply may input an input current of a predetermined current value to the leakage detection unit, and the determination unit may detect whether or not the disconnection has occurred in the leakage detection unit by comparing the input voltage value detected by the voltage detection unit with a predetermined threshold value.

Thus, the disconnection of the leakage detecting section can be detected with a simple configuration.

In the leak detection device according to the present invention, the leak detection unit may include a disconnection detection element connected between the conductive wires of the leak detection unit, the power supply may output a current corresponding to a current command value input from the determination unit, the determination unit may sweep the current command value output to the power supply to sweep an input current value of the leak detection unit, the leak detection units may be turned on in order of being connected to the start end, the input voltage value detected by the voltage detection unit when a range from the start end of the leak detection unit to one of the leak detection units is turned on and the input voltage value detected by the voltage detection unit when a range other than the one of the leak detection units in the range is turned on may be used, and calculating the conductance of one of the leak detection units, and comparing the calculated conductance with a predetermined threshold value to determine the leak detection unit in which the disconnection has occurred.

Thus, the leakage detecting means in which the disconnection has occurred can be specified with a simple configuration.

In the leakage detection device of the present invention, the constant voltage element of the leakage detection means may have a positive-direction on-voltage value different from a negative-direction on-voltage value, the power supply may be an ac power supply, and the determination unit may make a positive-direction amount of electric charge of an ac current output from the power supply equal to a negative-direction amount of electric charge of the ac current.

This can suppress occurrence of electrolytic corrosion of the liquid leakage detection zone when liquid leakage occurs.

In the leak detection device according to the present invention, the leak detection device may include a start-side leak detection section including a pair of the conductive wires, and when a leak contacts between the conductive wires, a current may flow through the start-side leak detection section, and the power supply may be connected to the start of the leak detection section via the start-side leak detection section.

This allows detection of leakage between the leakage detection unit and the power supply.

Effects of the invention

The invention can improve the reliability of the liquid leakage judgment by a simple structure.

Drawings

Fig. 1 is a system diagram showing a configuration of a leakage detection device according to an embodiment.

Fig. 2 is a system diagram showing the configuration of a leak detection unit of the leak detection apparatus shown in fig. 1.

Fig. 3 is a graph showing current versus voltage characteristics of a constant voltage device in which ideal zener diodes are connected in anti-series.

FIG. 4 is a view showing a leak detection unit U of the leak detection apparatus shown in FIG. 1_mA system diagram of current flow when liquid leakage occurs.

Fig. 5 is a graph showing voltage values applied to the respective leak detection cells when the input voltage value is increased in the leak detection device shown in fig. 1.

Fig. 6 is a graph showing voltage values applied to the respective leak detection cells when the input voltage value is set to the standby voltage value in the leak detection device shown in fig. 1.

Fig. 7 is a graph showing time changes of 3 kinds of input voltage values input to the leakage detecting device shown in fig. 1.

Fig. 8 is a graph showing a change characteristic (VI characteristic) of an input current value with respect to a change in an input voltage value in the case where liquid leakage occurs and the case where liquid leakage does not occur in the liquid leakage detection device shown in fig. 1, and a change in the input current value due to the occurrence of liquid leakage.

Fig. 9 is a graph showing a change characteristic (VI characteristic) of an input current value with respect to a change in an input voltage value in the case where liquid leakage occurs and the case where liquid leakage does not occur in the liquid leakage detection device shown in fig. 1, and a change in the input current value when the input voltage is changed before and after the standby voltage value when liquid leakage occurs.

Fig. 10 is a graph showing a change characteristic (VG characteristic) of the conductance with respect to a change in the input voltage value and a change in the conductance due to the occurrence of the leakage in the leakage detection device shown in fig. 1, in the case where the leakage occurs and the case where the leakage does not occur.

FIG. 11 is a view showing a leak detection unit U of the leak detection apparatus shown in FIG. 1_mA system diagram of current flow when liquid leakage occurs.

FIG. 12 is a view showing a leak detection unit U of the leak detection apparatus shown in FIG. 1_mA graph of a change characteristic (VI characteristic) of the input current value with respect to a change in the input voltage value when leakage occurs or when leakage does not occur, a change in the input current value with respect to a change in the input voltage value in each leakage detection unit when the input voltage value is swept, and a change in the conduction range.

Fig. 13 is a graph showing the change in conductance with respect to the input voltage value (VG characteristic) calculated based on the VI characteristic shown in fig. 12.

Fig. 14 is a graph showing the conductance of each leakage detection cell obtained from the characteristics shown in fig. 13.

FIG. 15 is a view showing two leak detection units U of the leak detection apparatus shown in FIG. 1₂、U_mA system diagram of current flow when liquid leakage occurs.

FIG. 16 is a view showing two leak detection units U of the leak detection apparatus shown in FIG. 1₂、U_mChange from input voltage value when leakage occurs or when leakage does not occurA change characteristic (VI characteristic) of the input current value with respect to each other, a change in the input current value with respect to a change in the input voltage value in each of the leak detection units when the input voltage value is swept, and a change in the conduction range.

Fig. 17 is a graph showing a change in conductance with respect to the input voltage value (VG characteristic) calculated based on the VI characteristic shown in fig. 16.

Fig. 18 is a graph showing the conductance of each leakage detection cell obtained from the characteristics shown in fig. 17.

Fig. 19 is a system diagram showing a configuration of a leakage detection device according to another embodiment.

FIG. 20 is a view showing a leak detection unit U of the leak detection apparatus shown in FIG. 19_mA system diagram of current flow when liquid leakage occurs.

Fig. 21 is a graph showing the temporal changes of 3 kinds of input current values input to the leakage detection device shown in fig. 19.

FIG. 22 shows a leak detection unit U of the leak detection apparatus shown in FIG. 19_mA graph of the change in input voltage when a liquid leak occurs and the voltage applied to each of the leak detection cells.

FIG. 23 is a view showing a leak detection unit U of the leak detection apparatus shown in FIG. 19_mAnd a graph showing a change characteristic (IV characteristic) of an input voltage value with respect to a change in an input current value in a case where liquid leakage occurs or a case where liquid leakage does not occur, and a change in an input voltage value due to the occurrence of liquid leakage.

Fig. 24 is an example of a lookup table of input voltage values detected by the voltage sensor and numbers of the leakage detecting means in which leakage has occurred.

FIG. 25 is a view showing a leak detection unit U of the leak detection apparatus shown in FIG. 19_mA graph showing a change characteristic (IV characteristic) of an input voltage value with respect to a change in an input current value when liquid leakage occurs or when liquid leakage does not occur, and a change in an input voltage value when the input current is changed before and after a standby current value when liquid leakage occurs.

FIG. 26 is a schematic view showingA leak detection unit U of the leak detection apparatus shown in FIG. 19_mAnd a change characteristic of conductance (IG characteristic) against a change in input current value when liquid leakage occurs or when liquid leakage does not occur, and a change in conductance due to the occurrence of liquid leakage.

FIG. 27 is a view showing a leak detection unit U of the leak detection apparatus shown in FIG. 19_mA system diagram of current flow when liquid leakage occurs.

Fig. 28 is a graph showing temporal changes in input current values and input voltage values when the input current values input to the leakage detection device shown in fig. 19 are swept.

FIG. 29 is a view showing a leak detection unit U of the leak detection apparatus shown in FIG. 19_mA change characteristic (VI characteristic) of the input current value with respect to a change in the input voltage value when leakage occurs or when leakage does not occur, a change in the input current value with respect to a change in the input voltage value in each leakage detection unit when the input current value is swept, and a change in the conduction range.

Fig. 30 is a graph showing the change in conductance with respect to the input voltage value (VG characteristic) calculated based on the VI characteristic shown in fig. 29.

Fig. 31 is a graph showing the conductance of each leakage detecting element obtained from the characteristics shown in fig. 30.

FIG. 32 is a view showing a leak detection unit U of the leak detection apparatus shown in FIG. 19₂、U_mA system diagram of current flow when liquid leakage occurs.

FIG. 33 is a view showing a leak detection unit U of the leak detection apparatus shown in FIG. 19₂、U_mA change characteristic (VI characteristic) of the input current value with respect to a change in the input voltage value when leakage occurs or when leakage does not occur, a change in the input current value with respect to a change in the input voltage value in each leakage detection unit when the input current value is swept, and a change in the conduction range.

Fig. 34 is a graph showing the change in conductance with respect to the input voltage value (VG characteristic) calculated based on the VI characteristic shown in fig. 33.

Fig. 35 is a graph showing the conductance of each leakage detection cell obtained from the characteristics shown in fig. 34.

FIG. 36 shows a leakage detecting unit U at the end of the leakage detecting device according to the embodiment shown in FIGS. 1 and 19_NendA system diagram of a leakage detection device according to another embodiment to which the disconnection detecting element is connected.

Fig. 37 is a graph showing a change characteristic (VI characteristic) of an input current value with respect to a change in an input voltage value in the case where disconnection occurs and the case where disconnection does not occur in the leak detection device shown in fig. 36, and a change in the input current value due to the occurrence of leakage.

Fig. 38 is a graph showing a change characteristic (VI characteristic) of an input current value with respect to a change in an input voltage value in the case where disconnection occurs and the case where disconnection does not occur in the leak detection device shown in fig. 36, and a change in the input current value due to the occurrence of leakage.

FIG. 39 shows a leakage detecting device according to the embodiment shown in FIGS. 1 and 19, in which each leakage detecting unit U is provided₁～U_NendA system diagram of a leakage detection device according to another embodiment in which the disconnection detection elements are connected to each other.

Fig. 40 is a graph showing a change characteristic (VI characteristic) of the input current value with respect to a change in the input voltage value in the case where the disconnection occurs and the case where the disconnection does not occur in the leakage detection device shown in fig. 39, and a change in the VI characteristic due to the occurrence of leakage.

Fig. 41 is a graph showing the change in conductance with respect to the input voltage value (VG characteristic) calculated based on the VI characteristic shown in fig. 40.

Fig. 42 is a graph showing the conductance of each leakage detection cell obtained from the characteristics shown in fig. 41.

Fig. 43 is a diagram showing changes in input voltage values, other input voltage values when sweeping the input current values, and other input current values.

Fig. 44A is an explanatory diagram showing another example of a node applied to the leakage detection device shown in fig. 1 and 19.

Fig. 44B is an explanatory diagram showing another example of a node applied to the leakage detection device shown in fig. 1 and 19.

Fig. 44C is an explanatory diagram showing another example of a node applied to the leakage detection device shown in fig. 1 and 19.

Fig. 44D is an explanatory diagram showing another example of a node applied to the leakage detection device shown in fig. 1 and 19.

Fig. 44E is an explanatory diagram showing another example of a node applied to the leakage detection device shown in fig. 1 and 19.

Fig. 44F is an explanatory diagram showing another example of a node applied to the leakage detection device shown in fig. 1 and 19.

Fig. 45 is a graph showing current versus voltage characteristics of constant voltage elements having different on-voltage values in the positive direction and negative direction.

Fig. 46 is a diagram showing a waveform of an output current of a power supply when the liquid leakage detection device according to the other embodiment is configured using the constant voltage element having the voltage-current characteristic shown in fig. 45.

Fig. 47 is a system diagram showing a leakage detection device according to another embodiment.

Fig. 48 is a system diagram showing a leakage detection device according to another embodiment.

Description of the reference symbols

11a, 11 b: a Zener diode; 12: a connecting wire; 13. 15: a starting end side terminal; 14. 16: a terminal at the end; 22: a constant voltage element circuit; 60: a leakage detection zone; 61. 62: a conductive wire; 61e, 62 e: an end portion; 63: insulating the coated wire; 65: a liquid leaking portion; 66: a starting end side leakage detection zone; 70: a liquid leakage detection unit; 71: a starting end; 72: a terminal end; 78: a disconnection detecting element; 79: a terminal resistance; 81: a power source; 82: a current sensor; 83: a voltage sensor; 90: a determination unit; 91: a CPU; 92: a memory; 93: an input interface; 94: an output interface; 95: a data bus; 100. 110, 120, 200, 210, 220, 300, 400: a liquid leakage detection device; D. d₁～D₅、D_m: a constant voltage element; n: numbering a liquid leakage detection unit; ND, ND₁～ND₅、ND_m: a node; u, U₁～U_Nend、U_m: and a liquid leakage detection unit.

Detailed Description

< construction of the leaked liquid detecting apparatus 100 according to embodiment 1 >

Hereinafter, the leakage detection apparatus 100 according to the embodiment will be described with reference to the drawings. As shown in fig. 1, the liquid leakage detection apparatus 100 includes: a liquid leakage detection unit 70; a power supply 81 connected to the start end 71 of the leakage detecting unit 70; a current sensor 82 as a current detection unit for detecting an input current value of the leakage detection unit 70; and a determination unit 90 for determining leakage based on the input current value detected by the current sensor 82.

As shown in FIG. 1, the leakage detecting section 70 is formed by combining a plurality of leakage detecting units U₁～U₅Are connected in series. Referring to FIG. 2, the secondary leakage detecting unit U is shown₁～U₅The leakage detecting unit number N of the connection order from the start end 71 of the leakage detecting unit 70 is m (N is m), that is, the m-th leakage detecting unit U from the start end 71_mThe structure of (a) will be explained. The number of the leakage detecting units U constituting the leakage detecting unit 70 is not limited to 5, and may be any number, and may be 1, or may be 6 or more.

As shown in fig. 2, a leakage detecting unit U_mHaving a constant voltage element D_mNode ND of_mAnd a leakage detecting tape 60 composed of a pair of conductive wires 61, 62. Node ND_mThe method comprises the following steps: a pair of start-end terminals 13, 15; a pair of distal-side terminals 14, 16; and a pair of connection lines 12 connecting the start-end terminals 13, 15 and the end-end terminals 14, 16 in parallel. As shown in fig. 2, a constant voltage element D is connected to the middle of the connection line 12 connecting the one start-end terminal 13 and the end-end terminal 14 with a constant voltage element D interposed therebetween_m. The other of the start-side terminal 15 and the end-side terminal 16 is connected to the constant voltage element D via the connecting wire 12_m. The pair of end terminals 14, 16 are connected to leakage detectionA pair of conductive wires 61, 62 of the tape 60, and end portions 61e, 62e of the pair of conductive wires 61, 62 on the respective distal ends side become a leakage detecting unit U_mThe end portion on the distal end side of (3). The pair of start-end terminals 13 and 15 serve as a leakage detecting unit U_mThe end portion on the starting end side. In this way, the leakage detecting section 70 includes a node ND connected in series from the start end 71 to the end 72_mLiquid leakage detection unit U_mThe node ND_mA constant voltage element D is arranged between the connection lines 12 on the side of the conductive line 61_m。

As shown in fig. 3, a constant voltage element D_mThe element is turned on when the absolute value of the applied voltage reaches a predetermined on-voltage value Vf, and is turned off when the absolute value of the applied voltage does not reach the on-voltage value Vf. In the leakage detection device 100 of the present embodiment, the constant voltage element D is provided_mThe zener diodes 11a and 11b having the turn-on voltage Vf are connected in anti-series to constitute the constant voltage device D having the characteristics shown in fig. 3_m. In the leakage detection device 100 of the present embodiment, each constant voltage element D is provided with a voltage detection circuit₁～D₅The case where all the on-voltage values of (b) are Vf and the same will be described. However, the constant voltage element D_mThe structure of (2) is not limited thereto. This point will be explained later.

The conductive wires 61 and 62 are nonconductive when no leakage occurs, and are conductive when leakage occurs. The conductive wires 61 and 62 may be formed by twisting copper wires covered with a hygroscopic insulating film or the like, for example.

As shown in fig. 1 and 2, the leakage detecting unit 70 includes a leakage detecting unit U_mThe end portions on the distal end side of (1), that is, the end portions 61e, 62e on the distal end side of the conductive wires 61, 62, and the leakage detecting unit U in this order_m+1The start-end-side terminals 13 and 15 are connected to each other. The 1 st leak detection unit U from the start end 71 of the leak detection unit 70₁The start-end side terminals 13 and 15 of the liquid leakage detecting section 70 constitute a start end 71 of the liquid leakage detecting section 70, and the 5 th liquid leakage detecting unit U is located from the start end 71 of the liquid leakage detecting section 70₅The end portions 61e, 62e of the conductive wires 61, 62 on the end side constitute the end 72 of the leakage detecting section 70. Make up for leakage detectionLiquid leakage detection unit U of start end 71 of measurement unit 70₁The start-end terminals 13 and 15 are connected to a power supply 81 via an insulating coated wire 63. In the power supply 81 and the leakage detecting unit U₁The current sensor 82 is connected between the one start terminal 13. Further, the end 72 of the leakage detecting section 70 is opened.

The power supply 81 is an alternating current power supply. The power supply 81 may be, for example, a power supply having an ac power of 100Hz and an output voltage of about 10V. The current sensor 82 is an alternating current detector that detects an alternating current value. The determination unit 90 is a computer having therein a CPU91, a memory 92, an input interface 93 connected to the power supply 81 and the current sensor 82, and an output interface 94 for outputting the calculation result of the CPU 91. The CPU91, memory 92, input interface 93, and output interface 94 are connected by a data bus 95. The power supply 81 outputs a voltage corresponding to the voltage command value input from the determination unit 90. The configuration of the determination unit 90 is not limited to this, and may be configured by an analog circuit, for example.

< operation of determining leakage of liquid leakage detecting apparatus 100 >

Hereinafter, the operation of determining the leakage of the leakage detecting apparatus 100 will be described with reference to fig. 4 to 10, and first, the input voltage value, the applied voltage of each leakage detecting unit U, and the conduction range a will be described with reference to fig. 5 and 6.

< input Voltage value and conduction Range >

When the input voltage value is zero, all the constant voltage elements D are turned off and become non-conductive. As shown in fig. 5, when the input voltage value at the start end 71 is increased from zero to the on-voltage value Vf, the leakage detecting unit U for the 1 st from the start end 71₁Constant voltage element D₁A voltage of Vf is applied. Thus, the constant voltage element D₁And (4) switching on. Constant voltage element D₁Is Vf, so that when the voltage at the start exceeds Vf, the leakage detecting unit U₁Between the conductive lines 61, 62 a voltage starts to be applied. Thereby, the leakage detecting unit U can be provided₁Carrying out liquid leakage detection. Thereafter, when the input voltage is increased, the voltage gradually increases from zero between the conductive lines 61 and 62. Conduction Range A at this time₁Only the leakage detecting unit U₁。

As shown in fig. 5, when the input voltage value is increased to 2 times the turn-on voltage value Vf by 2 × Vf, the leakage detecting unit U detects leakage₁Reaches Vf, and the 2 nd leak detection unit U starts from the start end 71₂Constant voltage element D₂The turn-on voltage value Vf is applied. Thus, the constant voltage element D₂Is connected to a leakage detecting unit U₂The voltage starts to be applied between the conductive lines 61 and 62, and the leakage detecting unit U can be operated₂And (4) detecting leakage. Conduction Range A at this time₂Is a leakage detecting unit U₁、U₂。

Similarly, when the input voltage value is increased to V_mWhen m × Vf, the leakage detecting unit U_mConstant voltage element D_mIs switched on, and a leakage detecting unit U is switched on₁To leakage detection unit U_mThe respective leak detection units U are turned on. The conduction range at this time is A_m. When the input voltage value is increased in this way, the leak detection units U are sequentially turned on in the order of connection with the start end 71 every time the input voltage value increases Vf.

Then, as shown in FIG. 6, when the input voltage value is raised to V_NendWhen Nend × Vf (herein Nend is the number of the leakage detecting unit U of the end 72), the leakage detecting unit U is driven by the motor₁To leakage detection unit U_NendAll the leak detection units U are turned on, and the leak can be detected in all the leak detection units U. Therefore, by setting the input voltage value to the ratio V_NendHigh standby voltage value V₀The leakage can be detected in all of the leakage detection units U.

Hereinafter, the input voltage value is set to the ratio V_NendHigh standby voltage value V₀The operation in the case of detecting leakage will be described. In this case, the input voltage value is made constant to the standby voltage value V as shown by the line a in FIG. 7₀The method (1 st determination operation) of setting the input voltage value to the standby voltage value V as shown by the line b in FIG. 7₀The method of (2 nd determination operation) and the voltage value V between zero and the standby voltage value V as shown by the line c in FIG. 7₀Is swept betweenThe method of inputting a voltage value (decision operation No. 3). Hereinafter, the 1 st determination operation will be described first, and the 2 nd and 3 rd determination operations will be described next.

< decision action 1 >

The determination unit 90 outputs the output voltage to the power supply 81 so that the output voltage is constant at the standby voltage value V₀Voltage command value of (1). Thus, the power supply 81 applies a constant standby voltage value V to the start end 71₀The voltage of (c).

As shown in fig. 8, when no leakage occurs, no current flows between the conductive lines 61 and 62 of each leakage detection unit U, and therefore the input current value detected by the current sensor 82 is zero.

On the other hand, as shown in FIG. 4, when the m-th leak detection unit U is detected_mWhen liquid leakage occurs, the liquid leakage detection unit U_mIs passed through I between the conductive lines 61, 62_m＝G_m(V₀-V_m) The current of (2). Here, G_mIs a leakage detecting unit U_mThe electrical conductance between the conductive lines 61, 62.

Therefore, the determination unit 90 compares the input current value detected by the current sensor 82 with a predetermined threshold value, and determines that liquid leakage has occurred when the input current value is greater than the predetermined threshold value. When determining that liquid leakage has occurred, the determination unit 90 issues an alarm to the external device via the output interface 94.

Here, the predetermined threshold value can be freely set, but may be determined by an experiment or the like according to the type of liquid or the like.

< decision action 2 >

As described above, when the input voltage value is raised to V_mWhen m × Vf, the leakage detecting unit U_mConstant voltage element D_mIs switched on, and a leakage detecting unit U is switched on₁To leakage detection unit U_mThe respective leak detection units U are turned on. In this case, when the m-th leak detection unit U is present_mWhen leakage occurs, the current starts to flow in the leakage detecting unit U_mBetween the conductive lines 61, 62. At this time, the conductance of the drain portion 65 is G_m. Then, when the input voltage value is raised, the leakage detecting unit U_mThe voltage between the conductive lines 61 and 62 becomes larger, and the input current value becomes larger. Therefore, when the leakage detecting unit U is in the state_mWhen the leakage occurs, the characteristic of the change in the input current value with respect to the change in the input voltage value (hereinafter referred to as VI characteristic) is shown by a broken line in fig. 9 until the input voltage value reaches V_mUntil now, the input current value is zero, and when the input voltage value exceeds V_mThe input current value increases with a certain slope. Further, the change characteristic of the conductance with respect to the change in the input voltage value (hereinafter referred to as VG characteristic) is shown by a broken line in fig. 10 until the input voltage value reaches V_mUntil now, the conductance G is zero, and exceeds V for the input voltage value_mThe conductance of the drain portion 65 is G_m。

Therefore, in the 2 nd determination operation, as shown in fig. 9, the input voltage value is set to the standby voltage value V₀The amount of change Δ I of the input current value is calculated from the change in the input current value detected by the current sensor 82, the conductance G is calculated as Δ I/Δ V, and the calculated conductance G is compared with a predetermined threshold value to determine leakage.

Determination unit 90 sets the voltage command value output to power supply 81 to standby voltage value V₀By Δ V. The power supply 81 sets the input voltage value applied to the start terminal 71 to the standby voltage value V according to the voltage command value₀By Δ V. Determination unit 90 detects the input current value by current sensor 82. Determination unit 90 calculates a change amount Δ I of the input current value from two input current values corresponding to two different voltage command values. Then, the determination unit 90 calculates the conductance G ═ Δ I/Δ V, and compares the calculated conductance G ═ Δ I/Δ V with a predetermined threshold value. Then, as shown in fig. 10, when the calculated conductance G is larger than a predetermined threshold value, it is determined that liquid leakage has occurred.

The calculation of the amount of change Δ I of the input current value is not limited to the use of two input current values corresponding to two different voltage command values, and may be performed using input current values corresponding to 3 or more voltage command values. In the 2 nd determination operation, instead of the conductance G, the resistance value R may be calculated as Δ V/Δ I, and it may be determined that liquid leakage has occurred when the resistance value is smaller than a predetermined threshold value.

In the above description, the amount of change Δ I of the input current value is calculated from two input current values corresponding to two different voltage command values, but a voltage sensor 83 for detecting the input voltage value of the start end 71 may be provided to detect the input voltage value, and the input voltage value detected by the voltage sensor 83 may be used instead of the voltage command value. In this case, the amount of change Δ I in the input current value is calculated from two input current values corresponding to two different input voltage values.

< decision action 3 >

In the 3 rd determination operation, the determination unit 90 determines that the voltage value V is zero and the standby voltage value V as indicated by the line c in fig. 7₀The sweep voltage command value is used to calculate the variation Δ I of the input current value from two input current values corresponding to the two voltage command values that vary due to the sweep. Then, similarly to the determination operation 2, the conductance G is calculated as Δ I/Δ V, and when the calculated conductance G is larger than a predetermined threshold value, it is determined that liquid leakage has occurred. In this case, the conductance G may be calculated using the input current value at the minimum voltage value and the input current value at the maximum voltage value.

In addition, as in the case of the 2 nd determination operation, the amount of change Δ I of the input current value is not limited to the use of two input current values corresponding to two voltage command values, and may be calculated using input current values corresponding to 3 or more voltage command values. Alternatively, instead of the conductance G, the resistance value R may be calculated to be Δ V/Δ I, and it may be determined that liquid leakage has occurred when the resistance value is smaller than a predetermined threshold value. In the same manner as in the above-described determination operation 2, the amount of change Δ I in the input current value may be calculated using the input voltage value detected by the voltage sensor 83 instead of the voltage command value.

In the description of the present operation, zero and the standby voltage value V are described₀The maximum value of the voltage command value is larger than V_Nend＝Nend×VfI.e. can be smaller than the standby voltage value V₀Or greater than the standby voltage value V₀。

As described above, in the 1 st determination operation, the standby voltage value V can be set₀The determination of the occurrence of liquid leakage is performed in a short time by a simple configuration in which the voltage is constant at a predetermined voltage value. In addition, the 2 nd and 3 rd judging operations make the input voltage value at the standby voltage value V₀The determination of the leakage is performed by calculating the conductance or the resistance value by sweeping the input voltage value, and therefore, the determination of the leakage can be performed by a physical quantity different from the input current value.

< operation for specifying leakage detecting means in which leakage has occurred >

Next, the operation of determining the leakage detection unit U in which leakage has occurred will be described with reference to fig. 11 to 14.

The operation of determining the occurrence of the leakage in the leakage detecting means is performed at zero and the standby voltage value V as shown by the line c in FIG. 7₀Sweep voltage command value, turn on the leakage detecting unit U in the order of connection with the starting end 71, and turn on the leakage detecting unit U according to the order₁～U_m-1Total conductance in the on state [ G ]₁+…+G_m-1]And a leakage detecting unit U₁～U_mTotal conductance in the on state [ G ]₁+…+G_m]Difference, calculating leakage detecting unit U_mConductance G of_mThe calculated conductance G_mThe determination unit determines a leakage detection unit U in which leakage has occurred by comparing the detected leakage with a predetermined threshold value.

< input Voltage value, conductance and conduction Range >

When the input voltage value is raised from zero to the standby voltage value V as shown by line c in FIG. 7₀As described above with reference to fig. 5, the leak detection units U are sequentially turned on in the order of connection to the start end 71. Fig. 12 is a graph in which VI characteristics are superimposed on changes in input current values and changes in conduction ranges in the respective leak detection units with respect to changes in input voltage values. Solid line of FIG. 12 showsVI characteristic in the case where no leakage occurs, and a dotted line shows the leakage detecting unit U_mThe VI characteristic in the case where liquid leakage occurs.

When the input voltage value is raised to V as shown in FIG. 12_mAnd V_m+1In between, leakage detecting unit U₁～U_mAnd becomes an on state. In this state, the input voltage value is varied by Δ V, and the variation Δ I of the input current value is calculated from the input current value detected by the current sensor 82, and in this case, as shown in fig. 13, the conductance G calculated by Δ I/Δ V is expressed by the following equation (1), and the leak detection unit U is turned on₁～U_mEach conductance G of₁～G_mThe total conductance of (c).

[ mathematical formula 1 ]

Similarly, when the input voltage value is increased to V_m-1And V_mIn between, leakage detecting unit U₁～U_m-1The conductance G calculated by the Δ I/Δ V is turned on, and the leak detection unit U is turned on as shown in the following equation (2)₁～U_m-1Each conductance G of₁～G_m-1The total conductance of (c).

[ mathematical formula 2 ]

Therefore, by subtracting the equation (2) from the equation (1), the leakage detecting unit U can be calculated as shown in fig. 14_mConductance G of_m. Then, by comparing the conductance G_mCan be judged in the leakage detecting unit U according to a predetermined threshold value_mAnd the leakage is not generated.

< details of the operation of specifying the leaking liquid detection means in which the leaking liquid occurred >

Hereinafter, a leakage detecting unit in which leakage occurs will be described with reference to fig. 12 to 14Determine details of the action. In the following description, the leakage detecting unit U is described_mThe case where liquid leakage occurs will be described.

The determination unit 90 sweeps the voltage value command value from zero to the standby voltage value V along the line c in fig. 7₀. Thus, the power supply 81 sweeps the input voltage value applied to the start terminal 71 from zero to the standby voltage value V in accordance with the voltage command value₀. As described above, when the input voltage value reaches Vf, the leakage detection unit U can detect leakage₁And (6) carrying out liquid leakage detection.

The determination unit 90 sweeps the voltage command value from Vf to a value slightly smaller than 2 × Vf, and sweeps the input voltage value from Vf to a value slightly smaller than 2 × Vf. During this time, only the leak detection unit U₁Becomes a conduction range (conduction range A)₁). During this period, the determination unit 90 detects two input current values corresponding to two voltage command values having a difference Δ V between the voltage command values by the current sensor 82. Then, the change amount Δ I of the input current value is calculated from the detected input current value, and the conductance G is calculated₁Δ I/Δ V. In the leakage detecting unit U₁No leakage occurs, and as shown in fig. 12, the input current value is maintained at zero between Vf and 2 × Vf, and therefore the conductance G₁＝ΔI/ΔV＝0。

Next, the determination unit 90 sweeps the voltage command value from 2 × Vf to a value slightly smaller than 3 × Vf, thereby sweeping the input voltage value from 2 × Vf to a value slightly smaller than 3 × Vf. During this period, the leakage detecting unit U₁And U₂Becomes a conduction range (conduction range A)₂). During this period, the determination unit 90 detects two input current values corresponding to two voltage command values having a difference Δ V between the voltage command values by the current sensor 82. Then, the variation Δ I of the input current value is calculated from the detected input current value, and the leakage detecting means U as the conduction range is calculated₁、U₂Total value of conductance [ G ]₁+G₂]＝ΔI/ΔV。

In the leakage detecting unit U₁、U₂No leakage occurs, and as shown in FIG. 12, the input current is increased from 2 x Vf to 3 x VfThe value remains zero, so Δ I equals 0, the total value of conductance [ G [ ]₁+G₂]Δ I/Δ V is 0. Judging part 90 from [ G ]₁+G₂]Subtracting the previously calculated G₁To obtain G₂Results are 0.

Similarly, the determination unit 90 calculates the total value Σ G of the conductance of the leak detection unit U in the conduction range every time the conduction range is expanded by sweeping the voltage command value, and calculates each conductance G of each leak detection unit U from the difference between the total value of the conductances calculated in the previous conduction range. In the leakage detecting unit U₁～U_m-1There occurs no leakage, and therefore, as shown in fig. 12, until the input voltage value reaches V_mThe input current values are all zero, and as shown in fig. 13, the calculated conductances G of the respective leak detection units U are all zero.

The determination unit 90 sweeps the voltage command value from m × Vf to a value slightly smaller than (m +1) × Vf, thereby sweeping the input voltage value from m × Vf to a value slightly smaller than (m +1) × Vf. During this period, the leakage detecting unit U₁～U_mBecomes a conduction range (conduction range A)_m). During this period, the determination unit 90 detects two input current values corresponding to two voltage command values having a difference Δ V between the voltage command values by the current sensor 82. Then, the variation Δ I of the input current value is calculated from the detected input current value, and the leakage detecting means U as the conduction range is calculated₁～U_mTotal value of conductance [ G ]₁+…+G_m]＝ΔI/ΔV。

In the leakage detecting unit U_mSince leakage occurs in the region, as shown in fig. 12, the change in the input current value during the period in which the input voltage value changes by Δ V is not zero, [ G [₁+…+G_m]Δ I/Δ V is a value other than 0. Judging part 90 from [ G ]₁+…+G_m]Subtract the previously calculated [ G ]₁+…+G_m-1]To obtain G_mThe value of (c).

The determination unit 90 sweeps the voltage command value from (m +1) × Vf to a value slightly smaller than (m +2) × Vf, thereby sweeping the input voltage value from (m +1) × vfto a value slightly smaller than (m +2) × Vf. During this period, the leakage detecting unit U₁～U_m+1Becomes a conduction range (conduction range A)_m+1). During this period, the determination unit 90 detects two input current values corresponding to two voltage command values having a difference Δ V between the voltage command values by the current sensor 82. Then, the variation Δ I of the input current value is calculated from the detected input current value, and the leakage detecting means U as the conduction range is calculated₁～U_m+1Total value of conductance [ G ]₁+…+G_m+1]＝ΔI/ΔV。

In the leakage detecting unit U_m+1Since no leakage occurs, as shown in fig. 12, the change in the input current value during the period in which the input voltage value changes by Δ V and the leakage detection unit U are detected₁～U_mBecomes a conduction range (conduction range A)_m) The same applies to the slope of the VI characteristic. Thus, [ G ]₁+…+G_m+1]Δ I/Δ V and G_mAre the same value. Judging part 90 from [ G ]₁+…+G_m+1]＝G_mSubtract the previously calculated [ G ]₁+…+G_m]＝G_mTo obtain G_m+1A value of 0.

In the leakage detecting unit U_mSince no leakage occurs thereafter, the gradient of the VI characteristic shown in FIG. 12 does not change, [ G ]₁+…+G_m+1]To [ G ]₁+…+G_Nend]All of them are G_mAs shown in FIG. 13, each conductance G_m+1～G_NendAll are zero.

Each of the leak detection units U calculated as described above₁～U_m+1Each conductance G of₁～G_m+1As shown in fig. 14, a leakage detecting unit U in which only leakage occurs_mIs a value other than 0G_mAll the conductances G of the other leakage detection units U are zero.

The determination unit 90 calculates each leakage detection unit U₁～U_m+1Each conductance G of₁～G_m+1A leakage detecting unit U for comparing the conductance G with a predetermined threshold value and detecting leakage of liquid having a conductance G larger than the predetermined threshold value_mAnd a leakage detecting unit U for determining that leakage occurs.

Next, referring to fig. 16 to 18, two leakage detections are performedUnit U₂、U_mThe determination operation of the leakage detecting means when leakage occurs will be described. For the in-leakage detecting unit U as described above_mThe operation of determining the leakage detecting unit U in the case where leakage occurs will be described in brief.

In the leakage detecting unit U, the same as described above with reference to FIGS. 11 to 14₁No leakage occurred, therefore G₁＝0。

In the leakage detecting unit U₂Leakage occurs, and thus the conductance G₂A value other than 0. In the leakage detecting unit U₃～U_m-1No leakage occurred, and therefore, as shown in fig. 16, the slope of the VI characteristic was constant, as shown in fig. 17, and the total conductance [ G₁+…+G₃]～[G₁+…+G_m-1]Constant is G₂. Further, as shown in fig. 18, a leakage detecting unit U₃～U_m-1Each conductance G of₃～G_m-1All are zero.

Further, as described above, the leakage detecting unit U is shown in fig. 18_mConductance G of_mA value other than 0, and m +1 th and subsequent leakage detecting units U_m+1～U_NendEach conductance G of_m+1～G_NendAll are zero.

The determination unit 90 calculates each leakage detection unit U₁～U_m+1Each conductance G of₁～G_m+1A leakage detecting unit U for comparing the conductance G with a predetermined threshold value and detecting leakage of liquid having a conductance G larger than the predetermined threshold value₂、U_mAnd a leakage detecting unit U for determining that leakage occurs.

The operation of determining the leakage detection unit U in which leakage occurs when leakage occurs in two leakage detection units U has been described above, but the operation of determining in which leakage occurs in 3 or more leakage detection units U is also the same as the operation of determining described above.

In the above-described determination operation, the input voltage value is swept to turn on the leak detection units U in the order of connection to the start end 71, the conductance G of each leak detection unit U is calculated, and the calculated conductance G is compared with a predetermined threshold value, so that the leak detection unit U in which a leak has occurred can be determined. This can improve the detection reliability of the liquid leakage portion with a simple configuration.

In the above determination operation, the amount of change Δ I of the input current value is calculated from two input current values corresponding to two different voltage command values, but as in the above-described determination operation 2, a voltage sensor 83 for detecting the input voltage value of the start end 71 may be provided to detect the input voltage value, and the input voltage value detected by the voltage sensor 83 may be used instead of the voltage command value. In this case, the amount of change Δ I in the input current value is calculated from two input current values corresponding to two different input voltage values.

In the above description of the determination operation, the leakage detecting unit U is described to be operated in accordance with the detected leakage₁～U_m-1Total conductance in the on state [ G ]₁+…+G_m-1]And a leakage detecting unit U₁～U_mTotal conductance in the on state [ G ]₁+…+G_m]Difference, calculating leakage detecting unit U_mConductance G of_mHowever, the leakage detecting unit U may be calculated by a calculation method other than the calculation method_mConductance G of_m。

For example, the leakage detecting unit U may be set to be in accordance with₁～U_NendTotal conductance in the case of being in the on state [ G₁+…+G_Nend]And a leakage detecting unit U₁～U_m-1Total conductance in the case of being in the on state [ G₁+…+G_m-1]The difference is calculated to make the leakage detection unit U_m～U_NendTotal conductance [ G ] when the conductive state is assumed to be on_m+…+G_Nend]. Furthermore, according to the total conductance [ G₁+…+G_Nend]And a leakage detecting unit U₁～U_mTotal conductance in the case of being in the on state [ G₁+…+G_m]The difference is calculated to make the leakage detection unit U_m～U_NendHypotheticalTotal conductance when ground is brought into the on state [ G ]_m+1+…+G_Nend]. Then, according to the total conductance [ G ]_m+…+G_Nend]And total conductance [ G_m+1+…+G_Nend]Difference calculation G_m。

< construction of the leaked liquid detecting apparatus 200 according to embodiment 2 >

Next, a description will be given of the liquid leakage detection device 200 according to embodiment 2 with reference to fig. 19 to 35. The same parts as those of the leakage detection apparatus 100 described above with reference to fig. 1 to 18 are denoted by the same reference numerals, and description thereof is omitted.

As shown in fig. 19, the leakage detection device 200 is provided with a voltage sensor 83 as a voltage detection unit instead of the current sensor 82 of the leakage detection device 100 described above. Further, power supply 81 outputs a current corresponding to the current command value input from determination unit 90. The end 72 of the leakage detecting section 70 is not opened, and the leakage detecting unit U constituting the end 72₅The end portions 61e and 62e of the conductive wires 61 and 62 on the end side are connected by an end resistor 79. The resistance value of the end resistor 79 is larger than the resistance value of the liquid for detecting liquid leakage.

< operation of determining leakage of liquid leakage detecting apparatus 200 >

The operation of the leakage determination by the leakage detection device 200 will be described below with reference to fig. 20 to 26. The determination operation has the input current value being made constant at the standby current value I as shown by the line a in FIG. 21₀The method (1 st determination operation) of setting the input current value at the standby current value I as shown by the line b in FIG. 21₀The method of (2 nd determination operation) and the standby current value I at zero as shown by the line c in FIG. 21₀The method of sweeping the input current value. First, the input voltage value, the applied voltage of each leakage detection unit U, and the conduction range a will be described with reference to fig. 22.

< input Voltage value and conduction Range >

When no leakage occurs, as described above with reference to fig. 5, each leakage detection unit U inputs power every time when the input voltage value is increased from zeroWhen the pressure value increases Vf, the leakage detecting unit U is connected to the start end 71 in this order₁～U_NendAre sequentially turned on. Then, when the input voltage value reaches V_NendWhen the value is (Nend) × Vf, the leakage detection unit U₁To leakage detection unit U_NendAll the leak detection units U are turned on, and the leak can be detected in all the leak detection units U.

When the input voltage value exceeds V_NendWhen this occurs, current starts to flow through the end resistor 79. As shown in FIG. 21, the standby current value I is maintained constant while the input current value is maintained₀In the case of (3), the current value flowing through the end resistor 79 becomes the standby current value I₀The voltage drop Δ V of the end resistor 79 at this time_EAt the end of the resistor 79 is set to G_EBecomes Δ V at the time_E＝I₀/G_E. And the input voltage value is V_Nend+ΔV_E。

The solid line in fig. 23 shows a change characteristic of the input voltage value with respect to a change in the input current value at this time (hereinafter referred to as an IV characteristic). As shown by the solid line in fig. 23, until the input voltage value reaches V_NendThe input current value is zero, and the current value flowing through the leakage detection unit 70 is zero. When the input voltage value exceeds V_NendWhen the input voltage value becomes larger, the input current value also becomes larger, and when the input voltage value reaches V_Nend+ΔV_EWhen the input current value reaches the standby current value I₀。

As shown in FIG. 20, the input current value is maintained at the standby current value I₀In the state of (1), in the leakage detecting unit U_mUnder the condition that liquid leakage occurs, a liquid leakage detection unit U_mConductance G of_mFrom zero to large, leakage detection unit U_mMedium current passing through I₀. Thereby, as shown in fig. 22 and 23, the leakage detecting unit U_mVoltage of (2) is set to Δ V in a voltage drop of the leakage portion 65_W0Time is decreased to V_m+ΔV_W0. Here, the voltage drop Δ V of the liquid leaking portion 65_W0The conductance of the drain portion 65 is set to G_mBecomes Δ V at the time_W0＝I₀/G_m。

In addition, to the specific leakage detecting unit U_m+1Leakage detecting unit U near the end_m+1～U_NendConstant voltage element D_m+1～D_NendThe voltage at is less than Vf. Thus, the constant voltage element D_m+1～D_NendBecomes non-conductive.

As described above, the standby current value I is maintained constant at the input current value₀In the case of (3), as shown in fig. 22 and 23, the input voltage value detected by the voltage sensor 83 is set to be V when there is no leakage_Nend+ΔV_EDown to V_m+ΔV_W0。

< decision action 1 >

The determination unit 90 outputs the output current to the power supply 81 so that the output current is constant at the standby current value I₀The current command value of (1). At this time, the input voltage value is set to V_Nend+ΔV_ESo that a standby current flows in the termination resistor 79. Thus, the power supply 81 outputs the standby current value I₀The current value flowing through the end resistor 79 becomes the standby current value I₀。

As described above, when no liquid leakage occurs, the input voltage value detected by the voltage sensor 83 is V_Nend+ΔV_E。

If in the leakage detection unit U_mWhen leakage occurs, the input voltage value detected by the voltage sensor 83 is V_Nend+ΔV_EDown to V_m+ΔV_W0. The determination unit 90 compares the input voltage value detected by the voltage sensor 83 with a predetermined threshold value to determine the occurrence of liquid leakage. For example, the determination unit 90 may determine that liquid leakage has occurred when the input voltage value decreases by a predetermined voltage value from the input voltage value in the standby state.

Further, when the leakage occurs, the input voltage value detected by the voltage sensor 83 decreases to V_m+ΔV_W0. Here, V_mSince the input voltage value detected by the voltage sensor 83 is (m) × Vf, the input voltage value becomes (m) × Vf + Δ V_W0. In this way, the input voltage value is based on occurrenceThe number of the leakage detecting unit U for leakage is different. For example, the leakage detecting means in which leakage occurs is U₁In the case of (2), the input voltage value is Vf + Δ V_W0. Then, Vf and standby current I are selected₀So as to make Δ V_W0Not exceeding Vf, enabling the leakage detection unit U_mInput voltage value (m) × Vf + Δ V in the case where liquid leakage occurs_W0Between (m) × Vf and (m +1) × Vf.

In this case, the comparison table shown in fig. 24 (a) is stored in the memory 92, and the determination unit 90 can determine the occurrence of liquid leakage and identify the liquid leakage detection unit U in which liquid leakage has occurred by comparing the input voltage value detected by the voltage sensor 83 with the range of the input voltage value in the comparison table.

For example, as shown in fig. 24 (a), when the input voltage value detected by the voltage sensor 83 is between Vf and 2 × Vf, it is determined that the leakage detecting means U is present₁Liquid leakage occurs. When the input voltage value detected by the voltage sensor 83 is between 2 × Vf and 3 × Vf, it is determined that the leakage detection unit U is present₂Liquid leakage occurs.

When the on-voltage values Vf of the constant voltage devices D in the leak detection units U are not all the same, the leak detection unit U in which the leak has occurred can be identified by applying the table shown in fig. 24 (b).

The table shown in (b) of FIG. 24 is applied to the constant voltage element D₁～D₅Respectively of 1(V), 2(V), 1(V), 1.5(V), and a leakage detection unit U₁～U₅Each of the input voltage values is configured to be turned on when the input voltage value exceeds 1(V), 3(V), 4(V), 5(V), and 6.5 (V). The determination unit 90 determines that the leakage detection unit U is in the case where the input voltage value detected by the voltage sensor 83 is 1(V) or more and less than 3(V), for example₁A leakage detection unit U for determining the occurrence of leakage, and when the input voltage value detected by the voltage sensor 83 is 3(V) or more and less than 4(V), the leakage detection unit U is set₂And a leakage detecting unit U for determining that leakage occurs.

< decision action 2 >

Next, the 2 nd determination operation will be described with reference to fig. 25. As shown by the solid line in fig. 25, when the input voltage value exceeds V in the case where no liquid leakage occurs_NendSince a current flows through the terminating resistor 79, the input current value increases as the input voltage value increases. In addition, as shown by the broken line in fig. 25, in the leakage detecting unit U_mWhen leakage occurs, the input voltage value exceeds V_mIn this case, since a current flows through the leakage portion 65, the input current value increases as the input voltage value increases. Conductance G of terminal resistor 79_EConductance G smaller than leakage part 65_mAnd thus the slope of the solid line is greater than the slope of the dashed line. The 2 nd determination operation is performed by setting the input current value to the standby current value I as shown in FIG. 25₀The amount of change Δ V of the input voltage value is calculated from the change in the input voltage value detected by the voltage sensor 83, the conductance G is calculated to be Δ I/Δ V, and the calculated conductance G is compared with a predetermined threshold value to determine leakage. As shown in FIG. 25, when no liquid leakage occurs, the input voltage value is V_Nend+ΔV_EFront to back. In addition, when the standby current value is I₀In the case of (3), when the leakage occurs, the input voltage value decreases to V_m+ΔV_W0So that the input voltage value is at V_m+ΔV_W0Front to back.

As shown in fig. 25, determination unit 90 sets the current command value output to power supply 81 to standby current value I₀By Δ I. At this time, the input voltage value is set to the ratio V_Nend+ΔV_ELarge so that a standby current flows in the end resistor 79. The power supply 81 sets the input current value to the standby current value I according to the current instruction value₀By Δ I. When no leakage occurs, the input voltage value is V_Nend+ΔV_EFront to back. When liquid leakage occurs, the input voltage value is V_m+ΔV_W0Front to back.

The determination unit 90 detects the input voltage value by the voltage sensor 83. As shown in fig. 25, the determination unit 90 calculates the amount of change Δ V of the input voltage value from two input voltage values corresponding to two different current command values. Then, the determination unit 90 calculates the conductance G ═ Δ I/Δ V, and compares the calculated conductance G ═ Δ I/Δ V with a predetermined threshold value. Then, as shown in fig. 26, when the calculated conductance G is larger than a predetermined threshold value, it is determined that liquid leakage has occurred.

Here, the predetermined threshold can be freely selected, but must be the conductance G of the specific end resistance 79_EA large value. For example, it may be conductance G_E1.5-2 times of the total amount of the active component.

The calculation of the change amount Δ V of the input voltage value is not limited to the use of two input voltage values corresponding to two different current command values, and may be calculated using input voltage values corresponding to 3 or more current command values. In the 2 nd determination operation, instead of the conductance G, the resistance value R may be calculated as Δ V/Δ I, and it may be determined that liquid leakage has occurred when the resistance value is smaller than a predetermined threshold value.

In the above description, the change amount Δ V of the input voltage value is calculated from two input voltage values corresponding to two different current command values, but the input current value may be detected by providing the current sensor 82 that detects the input current value of the start end 71, and the input current value detected by the current sensor 82 may be used instead of the current command value. In this case, the change amount Δ V of the input voltage value is calculated from two input voltage values corresponding to two different input current values.

< decision action 3 >

In the 3 rd determination operation, the determination unit 90 determines that the standby current value I is zero as indicated by the line c in fig. 21₀The sweep current command value is used to calculate the change amount Δ V of the input voltage value from two input voltage values corresponding to the two current command values changed by the sweep. At this time, the input voltage value is set to the ratio V_NendLarge so that a standby current flows in the end resistor 79. When no leakage occurs, the input voltage value is in the ratio V_NendVarying over a large range. In addition, when liquid leakage occurs, the input voltage value is set to be smaller than that in the case where liquid leakage does not occurLow voltage value in the ratio V_mVarying over a large range.

Then, similarly to the determination operation 2, the conductance G is calculated to be Δ I/Δ V, and when the calculated conductance G is larger than a predetermined threshold value, it is determined that liquid leakage has occurred. In this case, the conductance G may also be calculated using the input voltage value at the time of the minimum current value and the input voltage value at the time of the maximum current value.

Further, as in the case of the 2 nd determination operation, the calculation of the change amount Δ V of the input voltage value is not limited to the use of two input voltage values corresponding to two current command values, and may be calculated using input voltage values corresponding to 3 or more current command values. Alternatively, instead of the conductance G, the resistance value R may be calculated to be Δ V/Δ I, and it may be determined that liquid leakage has occurred when the resistance value is smaller than a predetermined threshold value. In addition, as in the case of the above-described determination operation 2, the input current value detected by the current sensor 82 may be used instead of the current command value.

In the description of the present operation, zero and the standby current value I are described₀The sweep current command value is set to be larger than the standby current value I₀Is large.

As described above, in the 1 st determination operation, the standby current value I can be set₀The determination of the occurrence of liquid leakage is performed in a short time by a simple configuration in which the leak current is constant at a predetermined current value. In addition, the 2 nd and 3 rd decision operations are performed by setting the input current value to the standby current value I₀The determination of leakage is performed by calculating the conductance or the resistance value by sweeping the input current value, and therefore, the determination of leakage can be performed by a physical quantity different from the input voltage value.

< operation for specifying leakage detecting means in which leakage has occurred >

Next, the operation of determining the leakage detection unit U in which leakage has occurred will be described with reference to fig. 27 to 35. In the following description, the leakage detecting unit U is described_mThe case where liquid leakage occurs will be described.

The operation of determining the occurrence of a liquid leak in the liquid leak detection means is, as shown by the line c in FIG. 28Shown at zero and a predetermined maximum current value I_maxSweep current command value, turn on the leakage detecting unit U in the order of connection with the start end 71, and turn on the leakage detecting unit U according to the order₁～U_m-1Total conductance in the on state [ G ]₁+…+G_m-1]And a leakage detecting unit U₁～U_mTotal conductance in the on state [ G ]₁+…+G_m]Difference, calculating leakage detecting unit U_mConductance G of_mThe calculated conductance G_mThe determination unit determines a leakage detection unit U in which leakage has occurred by comparing the detected leakage with a predetermined threshold value.

When no leakage occurs, the input voltage value is set to V so that a current flows through the end resistor 79_NendIn the above range, the current value is zero and the predetermined maximum current value I_maxSweep the input current value.

Determination unit 90 sweeps the current command value from zero to the maximum current value I along line c in fig. 28_max. Furthermore, the determination unit 90 sets the power supply 81 so that the input voltage value is at V_NendThe above range. Thus, the power supply 81 is set to zero and I according to the current command value_maxThe output current value is swept in between. At this time, as shown by the broken line in fig. 28 and fig. 29, the input voltage value is at V according to the input current value_NendThe above ranges. In this state, all the leak detection units U₁～U_NendAnd becomes an on state. Further, as shown by the solid line in fig. 29, when the input current value is zero, the input voltage value is V_NendIf the input current value becomes large, the input voltage value also becomes large.

In this state, as shown in fig. 29, the determination unit 90 sweeps the current command value by Δ I, and detects two input voltage values corresponding to two current command values having a difference Δ I between the current command values by the voltage sensor 83. Then, the change amount Δ V of the input voltage value is calculated from the detected input voltage value, and the conductance G ═ Δ I/Δ V is calculated. A leakage detecting unit U in which the conductance G calculated by the Δ I/Δ V is on₁～U_NendEach conductance G of₁～G_NendTotal conductance of [ G ]₁+…+G_Nend]. In the case where no leakage occurs, the leakage detecting unit U₁～U_Nend-1Each conductance G of₁～G_Nend-1All of which are zero, so that the judgment section 90 can detect the leakage detecting unit U by the above calculation_NendConductance G of_Nend. In the leakage detecting unit U_NendIn the case of no leakage, the conductance G_NendConductance G as terminal resistance 79_E。

When the leakage occurs, as described above, the input voltage value when the input current value is zero is set to be from V_NendDown to V_m. Therefore, if at zero and the specified maximum current value I_maxSweep the input current value between, the input voltage value is at V according to the input current value as shown by the one-dot chain line in FIG. 28_mThe above ranges. Further, as shown by the broken line in fig. 29, when the input current value is zero, the input voltage value is V_m(m × Vf), if the input current value becomes large, the input voltage value also becomes large. When the input current value becomes larger, the input voltage value exceeds V_NendWhen (═ Nend × Vf), a current flows through the end resistor 79, and therefore the slope of the VI characteristic increases.

In this case, when the input current value is zero, the leakage detecting unit U₁～U_mBecomes a conduction state and becomes a specific leakage detecting unit U_mLeakage detecting unit U near the end_m+1～U_NendAnd becomes a non-conductive state. Then, the input current value is increased to increase the input voltage value, and each of the leak detection units U is sequentially turned on in the order of connection to the start end 71 each time Vf increases the input voltage value. Then, when the input voltage value reaches V_NendAll the leakage detecting units U₁～U_NendThe on state is established, and a current starts to flow through the end resistor 79.

The determination unit 90 sweeps the current command value by Δ I so that the input voltage value falls within a range from m × Vf to a value slightly smaller than (m +1) × Vf. Then, two current command values having a difference Δ I from the current command value are detected by the voltage sensor 83Corresponding two input voltage values. Then, the change amount Δ V of the input voltage value is calculated from the detected input voltage value, and the conductance G ═ Δ I/Δ V is calculated. A leakage detecting unit U in which the conductance G calculated by the Δ I/Δ V is on₁～U_mEach conductance G of₁～G_mTotal conductance of [ G ]₁+…+G_m]。

In the leakage detecting unit U₁～U_m-1No leakage occurs, so the leakage detecting unit U₁～U_m-1Each conductance G of₁～G_m-1All are zero. Therefore, the judgment unit 90 can detect the leakage detection unit U by the above calculation_mConductance G of_m. In the leakage detecting unit U_mWhere leakage occurred, therefore G_mBecomes a value other than zero. However, since the resistance value of the end resistor 79 is set to be larger than the resistance value of the leakage portion 65, G_mG calculated before_EIs large.

The determination unit 90 further sweeps the current command value by Δ I so that the input voltage value falls within a range from (m +1) × Vf to a value slightly smaller than (m +2) × Vf. Thereby, the leakage detecting unit U_m+1And becomes an on state. Then, as described above, the voltage sensor 83 detects two input voltage values corresponding to two current command values having a difference Δ I between the current command values, and calculates the conductance G ═ Δ I/Δ V. A leakage detecting unit U in which the conductance G calculated by the Δ I/Δ V is on₁～U_m+1Each conductance G of₁～G_m+1Total conductance of [ G ]₁+…+G_m+1]. The judgment part 90 conducts electricity from the total electric conductance G₁+…+G_m+1]Subtract the previously calculated total conductance G₁+…+G_m]To calculate the leakage detecting unit U_m+1Conductance G of_m+1。

As shown in fig. 29, since the slope of the VI characteristic between the input voltage values m × Vf and (m +1) × vfis the same as the slope of the VI characteristic between the input voltage values (m +1) × vfand (m +2) × Vf, the values of Δ I/Δ V are equal to each other. Thus, as shown in FIG. 30, the total conductance [ G ]₁+…+G_m]Value of (d) and total conductance [ G₁+…+G_m+1]Are equal in value. Therefore, the conductance G_m+1Is zero.

Thereafter, similarly, the input current value is increased while the input voltage value is detected by the voltage sensor 83, and based on this, the leakage detection unit U is calculated_m+2～U_Nend-1Each conductance G of_m+1～G_Nend-1. As shown in fig. 29, until the input voltage value reaches V_NendThe slope of the VI characteristic is constant until now, so that the total conductance calculated at each stage has the same value, conductance G_m+2～G_Nend-1All are zero.

Determination unit 90 increases the current command value further, and when the input voltage value detected by voltage sensor 83 exceeds V_NendIn this case, the slope of the VI characteristic becomes large. Similarly to the above description, the input voltage value is detected by the voltage sensor 83 while increasing the input current value, and based on this, the conductance G is calculated₁～G_NendTotal conductance of [ G ]₁+…+G_Nend]。

The judgment part 90 conducts electricity from the total electric conductance G₁+…+G_Nend]Subtract the previously calculated total conductance G₁+…+G_Nend-1]To obtain G_NendAs a leakage detecting unit U_NendThe conductance of (2). In the leakage detecting unit U_NendIn the case of no leakage, the conductance G_NendConductance G as terminal resistance 79_E。

FIG. 31 shows each of the leakage detecting units U calculated by the determination unit 90 as described above₁～U_NendEach conductance G of₁～G_NendA change in (c). As shown in fig. 31, a leakage detecting unit U that causes leakage_mConductance G of_mA value other than zero. Further, a leakage detecting unit U including a terminal resistor 79_NendConductance G of_NendConductance G as terminal resistance 79_E. The conductance G of each of the other leakage detecting units U is all zero.

Then, the value of the conductance G exceeds the conductance G of the specific end resistance 79_EWhen the predetermined threshold value is large, the determination unit 90 determines the leakage detection unit U as the leakage detection in which leakage has occurredAnd a unit U is measured.

Next, referring to fig. 32 to 35, as shown in fig. 32, the leakage detecting unit U is aligned with the liquid leakage detecting unit U₂And a leakage detection unit U_mThe determination operation in the case where liquid leakage occurs at these two points will be described. For the in-leakage detecting unit U as described above_mThe operation similar to the determination operation when liquid leakage occurs will be briefly described.

As shown in fig. 33, in the leakage detecting unit U₂When the leakage occurs, the input voltage value when the input current value is zero is decreased to 2 × Vf. When the input current value is swept, the input voltage value changes in a range of 2 × Vf or more in accordance with the input current value.

The determination unit 90 sweeps the current command value by Δ I so that the input voltage value falls within a range from 2 × Vf to a value slightly smaller than 3 × Vf. Then, two input voltage values corresponding to two current command values having a difference Δ I between the current command values are detected by the voltage sensor 83. Then, the change amount Δ V of the input voltage value is calculated from the detected input voltage value, and the conductance G ═ Δ I/Δ V is calculated. A leakage detecting unit U in which the conductance G calculated by the Δ I/Δ V is on₁～U₂Each conductance G of₁～G₂Total conductance of [ G ]₁+G₂](refer to fig. 34).

In the leakage detecting unit U₁No leakage occurs, so the conductance G₁Is zero. Therefore, the determination unit 90 can calculate the leakage detection unit U by the above calculation₂Conductance G of₂. In the leakage detecting unit U₂Where leakage occurred, therefore G₂Is a certain value other than zero and is a ratio G_EA large value.

The determination unit 90 detects the input voltage value by the voltage sensor 83 while increasing the input current value, and calculates the leakage detection unit U based on the detected input voltage value₃～U_m-1Each conductance G of₃～G_m-1. As shown in fig. 33, until the input voltage value reaches V_mThe slope of the VI characteristic is constant until then, so the total conductance calculated at each stage isOf the same value, conductance G₃～G_m-1All are zero.

Determination unit 90 increases the current command value further, and when the input voltage value detected by voltage sensor 83 exceeds V_mIn this case, as shown in fig. 33, the slope of the VI characteristic increases. Similarly to the above description, the input voltage value is detected by the voltage sensor 83 while increasing the input current value, and based on this, each conductance G is detected₁～G_mTotal conductance of [ G ]₁+…+G_m](refer to fig. 34).

The judgment part 90 conducts electricity from the total electric conductance G₁+…+G_m]Subtract the previously calculated total conductance G₁+…+G_m-1]To obtain G_mAs a leakage detecting unit U_mThe conductance of (2). In the leakage detecting unit U_mWhere leakage occurred, therefore G_mIs a certain value other than zero and is a ratio G_EA large value.

The determination unit 90 increases the input voltage command value further, and obtains the leakage detection unit U in the same manner as described above_NendConductance G of_Nend. In the leakage detecting unit U_NendIn the case of no leakage, the conductance G_NendConductance G as terminal resistance 79_E(refer to fig. 34).

FIG. 35 shows each of the leak detection units U calculated by the judgment unit 90 as described above₁～U_NendEach conductance G of₁～G_NendA change in (c). As shown in fig. 35, a leakage detecting unit U that causes leakage₂、U_mConductance G of₂、G_mBecomes a value other than zero. Further, a leakage detecting unit U including a terminal resistor 79_NendConductance G of_NendConductance G as terminal resistance 79_E. The conductance G of each of the other leakage detecting units U is all zero.

Then, the value of the conductance G exceeds the conductance G of the specific end resistance 79_EWhen the predetermined threshold value is large, the determination unit 90 identifies the leakage detection unit U as a leakage detection unit U in which leakage has occurred.

In addition, in the leakage detecting unit U_NendIs arranged atIn the case of a leak, the leak detection unit U including the end resistor 79_NendConductance G of_NendBecomes the conductance G of the terminal resistor 79_ETo which an increased value of the conductance caused by the leakage is added. The value is G shown in FIG. 35_mThe same size.

The operation of determining the leakage detection unit U in which leakage occurs when leakage occurs in two leakage detection units U has been described above, and the operation of determining in which leakage occurs in 3 or more leakage detection units U is also the same as the operation of determining described above.

In the above-described determination operation, the input current value is swept to turn on the leak detection units U in the order of connection to the start end 71, the conductance G of each leak detection unit U is calculated, and the calculated conductance G is compared with a predetermined threshold value, so that the leak detection unit U in which a leak has occurred can be determined. This can improve the detection reliability of the liquid leakage portion with a simple configuration.

In the above description, the change amount Δ V of the input voltage value is calculated from two input voltage values corresponding to two different current command values, but the input current value may be detected by providing the current sensor 82 that detects the input current value of the start end 71, and the input current value detected by the current sensor 82 may be used instead of the current command value. In this case, the change amount Δ V of the input voltage value is calculated from two input voltage values corresponding to two different input current values.

< wire breakage detection action >

The disconnection detection operation of the leakage detecting unit 70 will be described below with reference to fig. 36 to 38. The leakage detecting device 110 shown by a solid line in fig. 36 is the leakage detecting unit U of the leakage detecting device 100 described above with reference to fig. 1_NendThe disconnection detecting element 78 is connected to detect disconnection. The leakage detection device 210 shown by a broken line in fig. 36 shows a case where the voltage sensor 83 is attached in place of the current sensor 82 of the leakage detection device 110. The disconnection detecting element 78 may be a resistor or may be a resistor that limits the current to a constant levelA constant current element of the flow value.

Fig. 37 shows VI characteristics of the leakage detection apparatus 100 shown in fig. 36. As shown by the solid line in fig. 37, when the disconnection does not occur, the input voltage value reaches V_NendUntil now, the input current value is zero, and when the input voltage value exceeds V_NendWhen the current starts to flow through the disconnection detecting element 78, the current value starts to increase from zero. When the disconnection occurs, no current flows through the disconnection detection element 78, and therefore, even if the input voltage value exceeds V_NendThe input current value is also kept at zero.

Determination unit 90 applies standby voltage value V to start end 71₀The input current value is detected by the current sensor 82. As shown in fig. 37, when the disconnection does not occur, the input current value detected by the current sensor 82 is equal to or greater than a predetermined threshold value that is greater than zero.

When the disconnection occurs, the input current value detected by the current sensor 82 becomes zero which is lower than the threshold value. In this way, the determination unit 90 detects the occurrence of a wire break by comparing the input current value detected by the current sensor 82 with a predetermined threshold value.

As shown in fig. 38, when a standby current flows instead of the standby voltage and the voltage sensor 83 detects the input voltage value, the standby current value I is set to be the standby current value I when the line is not broken₀The voltage drop of the disconnection detecting element 78 in the case of (3) is set to Δ V_DThe input voltage value detected by the voltage sensor 83 is V_Nend+ΔV_D. On the other hand, in the leakage detecting unit U_mWhen the disconnection occurs, the voltage detected by the voltage sensor 83 is increased to the maximum output voltage value V of the power supply 81_max。

Therefore, determining unit 90 sets standby current value I₀Flows through the leakage detecting section 70, and passes through the input voltage value detected by the voltage sensor 83 and the initial voltage value V_Nend+ΔV_DBy performing the comparison, the occurrence of disconnection can be detected. In addition, V may be replaced by V_Nend+ΔV_DAnd comparing the detected value with a predetermined threshold value to detect the occurrence of a disconnection.

In the leak detectors 110 and 210, the disconnection detecting element 78 and the end leak detecting unit U have been described_NendIn the case of connection, the disconnection detecting element 78 may be connected to any leakage detecting unit U, but the connection is not limited thereto.

< determination of means for detecting leakage of broken wire >

Next, the determination of the leakage detecting unit U in which the wire breakage has occurred will be described with reference to fig. 39 to 42. In the following description, a case where a wire break occurs in the leak detection unit Um is described.

The leakage detection device 120 shown by a solid line in fig. 39 is a device for identifying a leakage detection unit U in which a disconnection has occurred by connecting the disconnection detecting element 78 between the conductive lines 61 and 62 of each leakage detection unit U in the leakage detection device 100 described above with reference to fig. 1. The leakage detection device 220 shown by a broken line in fig. 39 shows a case where the voltage sensor 83 is attached in place of the current sensor 82 of the leakage detection device 120. The disconnection detecting element 78 may be a resistor, or may be a constant current element that limits the current to a constant current value.

As shown in FIG. 38, the leakage detecting units U attached to the respective units will be described₁～U_NendThe conductance of the disconnection detecting element 78 is conductance G₁～G_NendThe case (1).

As described above, when the input voltage value is swept and increased, the respective leakage detecting units U are sequentially turned on in the order of connection with the start end 71 every time the input voltage value increases Vf. As shown in fig. 40 and 41, when the input voltage value is increased to Vf, the leakage detecting unit U₁On, the input voltage value is swept by Δ V in this state, the variation Δ I of the input current value is calculated from the input current value detected by the current sensor 82, and the leakage detection unit U is calculated from Δ I/Δ V₁Conductance G of₁. Then, the input voltage value is increased to 2 × Vf, and the leakage detecting unit U is caused to leak₁、U₂On, the input voltage value is swept by Δ V in this state, and the input voltage value is measured from the input current value detected by the current sensor 82Calculating the variation delta I of the input current value, and calculating the leakage detection unit U according to delta I/delta V₁～U₂Total conductance of [ G ]₁+G₂]. Then, from [ G ]₁+G₂]Minus G₁To calculate G₂。

Similarly, the input voltage value is increased from (m-1) Vf to a value slightly smaller than (m) Vf, and the leakage detecting means U is operated₁～U_m-1Conducting and calculating leakage detection unit U₁～U_m-1Total conductance of [ G ]₁+…+G_m-1]Then, the input voltage value is increased from (m) × Vf to a value slightly smaller than (m +1) × Vf, and the leakage detecting means U is caused to detect leakage₁～U_mConducting and calculating leakage detection unit U₁～U_mTotal conductance of [ G ]₁+…+G_m]From the total conductance [ G₁+…+G_m]Minus [ G ]₁+…+G_m-1]To calculate the leakage detecting unit U_mConductance G of_mRepeating the above steps to calculate each leakage detection unit U₁～U_NendEach conductance G of₁～G_Nend。

Each leakage detecting unit U is not broken₁～U_NendEach conductance G of₁～G_NendIs mounted on each leakage detecting unit U₁～U_NendRespective conductance G of the disconnection detecting element 78₁～G_NendAnd therefore does not become zero. Respective conductance G of the disconnection detecting element 78₁～G_NendIs G_NAnd in the same case, as shown in fig. 42, each of the leak detection units U₁～U_NendAll are G_N。

On the other hand, as shown in fig. 39, in the leakage detecting unit U_mWhen the disconnection of the start end of the disconnection detecting element 78 is detected, the input voltage value is increased to V_mAbove, leakage detecting unit U_m+1～U_NendIt is not in the energized state. In this case, as shown by the broken line in fig. 40, the input current value becomes larger as the input voltage value becomes larger, but the VI characteristic slope is constant and the slope does not change.

Thus, inLiquid leakage detection unit U_mWhen the disconnection of the leading end side of the disconnection detecting element 78 in (2) occurs, the total conductance calculated from Δ I/Δ V is constant at [ G ] as shown by the broken line in fig. 41₁+…+G_m-1]. Therefore, as shown in fig. 42, the specific leakage detecting unit U is calculated_mLeakage detecting unit U near the end_m～U_NendEach conductance G of_m～G_NendAll are zero.

As described above, the determination unit 90 detects leakage of each liquid leakage detection unit U₁～U_NendEach conductance G of₁～G_NendThe presence of disconnection in the leakage detecting unit U on the first end side among the leakage detecting units U having a conductance G smaller than the predetermined threshold value can be determined by comparison with the predetermined threshold value.

As shown by the broken line in fig. 39, since the voltage sensor 83 is provided instead of the current sensor 82 and the input current value is increased by sweeping the input current value, the input voltage value is increased in accordance with the input current value, and therefore, the leakage detecting unit U in which the disconnection has occurred can be identified by the same method as described above.

< other Voltage, Current sweep waveform >

As previously explained with reference to fig. 7, the input voltage value is swept such that the input voltage value is at zero and the standby voltage value V₀The sweep is performed so as to change linearly, but the sweep is not limited to this, and as shown in fig. 43, the input current value may be increased in a stepwise manner in units of Vf, and the sweep may be performed so that the input voltage value varies between m × Vf and (m +1) × Vf. The sweep waveform has a strong anti-noise effect.

In addition, when sweeping the input current value, the input current value may not be set to zero and the maximum current value I as shown in fig. 28_maxThe sweep is performed so as to change linearly, but as shown in fig. 43, the input current value is increased in stages, and the input current is varied in each stage.

< variation of constant Voltage element >

Referring to FIGS. 44A to 44F, the constant voltage element D is provided_mVariations of (2) will be described. In-leakage detection deviceIn the devices 100 and 200, with respect to the constant voltage element D_mThe case where the zener diodes 11a and 11b are connected in anti-series with one connecting line 12 interposed therebetween has been described, but the present invention is not limited thereto, and may be configured as shown in fig. 44A to 44F.

As shown in fig. 44A, the zener diodes 11a and 11b may be connected in anti-series in the opposite direction to the state shown in fig. 2. As shown in fig. 44B, the connection line 12 may be disposed on the side opposite to the side shown in fig. 2. Further, as shown in fig. 44C and 44D, one zener diode 11a, 11b may be disposed in the same direction on each of the two connection lines 12, and the two zener diodes 11a, 11b may be connected in anti-series with respect to the flow of current when liquid leakage occurs. As shown in fig. 44E, the zener diode 11a may be interposed only in one of the connection lines 12. In this case, the power supply 81 may be configured using a dc power supply. As shown in fig. 44F, instead of the zener diodes 11a and 11b, the constant voltage device circuit 22 may be used, and the constant voltage device circuit 22 may be a circuit having the voltage-current characteristics shown in fig. 3, such as an IC.

Thus, the node ND is detected by the liquid according to the detection object_mConstant voltage element D_mThe arrangement of (3) is variously changed, and leakage detection can be performed in accordance with the liquid to be detected.

In the leakage detection device 100 of the embodiment, the constant voltage element D is provided_mWhile the absolute value of the on-voltage value in the positive direction and the absolute value of the on-voltage value in the negative direction are the same Vf, the present invention is not limited to this, and a constant voltage element having a positive on-voltage value Vf1 and a negative on-voltage value Vf2 that are different in absolute value may be used as shown in fig. 45.

In this case, since the input current value in the positive direction is different from the input current value in the negative direction, there is a case where electrolytic corrosion occurs in the conductive lines 61 and 62. Therefore, the time for outputting the positive current from the power supply 81 and the time for outputting the negative current are set to have different lengths, and the area of the positive region (indicated by left hatching) and the area of the negative region (indicated by right hatching) shown in fig. 46 are made the same. Accordingly, the amount of electric charge flowing in the positive direction of the conductive lines 61 and 62 of the alternating current output from the power supply 81 is equal to the amount of electric charge flowing in the negative direction, and the occurrence of electrolytic corrosion on the conductive lines 61 and 62 can be suppressed.

Next, a liquid leakage detection device 300 according to another embodiment will be described with reference to fig. 47. FIG. 47 shows constant voltage elements D alternately arranged in odd-numbered liquid leakage detecting units U and even-numbered liquid leakage detecting units U_mA drawing of the connecting line 12. The leakage detection device 300 of the present embodiment has the same operation and effect as the leakage detection device 100 described above.

Fig. 48 shows a leakage detection apparatus 400 according to another embodiment. The leak detection device 400 is connected between the power supply 81 and the start end 71 via the start end side leak detection belt 66, and the start end side leak detection belt 66 is formed of the conductive wires 61 and 62, and when a leak contacts, a current flows through the start end side leak detection belt 66.

In the present embodiment, when the input voltage value is between zero and Vf and the current value detected by the current sensor 82 exceeds a predetermined threshold value, it can be determined that liquid leakage has occurred on the leading end side of the leading end 71. The leakage detecting device 400 has fewer constant voltage elements D than the leakage detecting device 100_mThe same number of the functional components plays the same role and effect. The number of the leakage detecting units U constituting the leakage detecting unit 70 is not limited to 5, and may be any number, and may be 1, or may be 6 or more.

The leakage detection devices 100, 200, 300, and 400 according to the embodiments described above can improve the reliability of the leakage determination with a simple configuration.