JP5642959B2 - Weighing device, load detector, weighing system, and method of detecting deterioration of lightning protection element - Google Patents

Description

  The present invention relates to a load detector for detecting a load, a weighing device connected to the load detector via a connection line, a weighing system including them, and a method of detecting deterioration of a lightning arrester connected to the connection line. .

  In the weighing system, the load of the platform on which an object to be weighed such as a vehicle is detected by the load cell, the load signal from the load cell is processed by an indicator connected to the load cell, and the weight of the object to be weighed is displayed. There is something like that (see, for example, Patent Document 1).

  In such a weighing system, the load cell, which is a load detector, is installed outdoors, and the indicator that processes the load signal from the load cell and displays the measured value is installed indoors, and both are connected by a long connection line. There may be a lightning arrester such as a gas arrester or semiconductor arrester that absorbs a surge voltage due to induced lightning between the connection line and the ground at positions close to the load cell and the indicator at both ends of the connection line. Is inserted to protect the load cell and the indicator.

JP-A-5-322637

  The insulation resistance of a lightning protection element that is generally used is, for example, 60 GΩ or more for a gas arrester and 500 MΩ or more for a semiconductor arrester. The lightning arrester is deteriorated by the number of surges applied, the voltage, and the current. When the lightning arrester is deteriorated, correct measurement cannot be performed because the measured value becomes unstable.

  Conventionally, when a phenomenon such as an unstable measurement value occurs, to determine whether the cause is due to deterioration of the lightning protection element, an insulation resistance meter is used to determine the insulation resistance of each lightning protection element. The value was measured to determine the presence or absence of deterioration.

  Measurement with such an insulation resistance meter must be performed for each lightning protection element of a plurality of lightning protection elements connected to a plurality of connection lines, and the measurement work is troublesome. Therefore, a deteriorated lightning protection element is identified, and a new lightning protection element is identified. There is a problem that it takes time to replace the element and restore the weighing system, and the non-operation time until the weighing is restarted is increased.

  Also, if you do not have an insulation resistance meter at the site where the measured value becomes unstable, etc., whether the measured value is unstable due to the deterioration of the lightning protection element It is difficult to make such a determination.

  The present invention has been made in view of the above points, and it is an object of the present invention to detect deterioration of a lightning arrester without an insulation resistance meter.

  In order to achieve the above object, the present invention is configured as follows.

(1) That is, the weighing device of the present invention is connected to a load detector that converts a load into an electrical signal via a plurality of connection lines, and processes the electrical signal from the load detector to be weighed. A weighing device for weighing an object, wherein a plurality of lightning protection elements are connected to the plurality of connection lines, and includes deterioration detection means for detecting deterioration of the lightning protection elements, and the deterioration detection means includes the plurality of lightning protection elements . A selection unit that individually selects each connection line of the connection line, a voltage application unit that applies a voltage to the connection line selected by the selection unit, and a combined resistance value on the connection line side to which a voltage is applied by the voltage application unit And a determination unit for determining the presence or absence of a lightning arrester having a deteriorated insulation resistance based on the measured voltage value .

  The number of lightning protection elements and connection locations are not particularly limited, but it is preferable to connect to a connection line at a location close to the load detector and the weighing device.

  The connection line is not limited to an external connection line of the weighing device, and may include an internal connection line.

  According to the weighing device of the present invention, since the deterioration detecting means for detecting the deterioration of the lightning arrester connected to the plurality of connection lines between the load detectors is provided, the lightning arrester can be installed without an insulation resistance meter. Degradation can be detected. For example, when a phenomenon such as an unstable measurement value occurs, the degradation detection means determines whether the cause is due to degradation of the lightning protection element. It is possible to check whether or not the lightning protection element is deteriorated by the deterioration detecting means before starting the weighing operation.

The metering equipment of the present invention, the deterioration detecting means, applying a selection unit for selecting individually each connection line of said plurality of connection lines as described above, the voltage on the connection line selected by the selecting section A voltage applying unit, a voltage measuring unit for measuring a voltage value based on a combined resistance value on a connection line side to which a voltage is applied by the voltage applying unit, and a lightning protection element having a deteriorated insulation resistance based on the measured voltage value. A determination unit for determining presence or absence.

  Based on the measured voltage value, the insulation resistance value of the lightning protection element may be calculated to determine the presence or absence of deterioration, or the measured voltage value is compared with a predetermined threshold without calculating the insulation resistance value. Then, the presence or absence of deterioration may be determined.

According to the weighing device of the present invention , each connection line is selected, and the presence or absence of a deteriorated lightning arrester is determined based on the voltage value based on the combined resistance value on the selected connection line side. Whether or not the lightning protection element connected to the connection line has deteriorated can be determined.

  Therefore, for example, when a load cell that is a load detector is connected to the weighing device via a plurality of connection lines, when one of the plurality of connection lines is selected, the selected connection line is Is connected to all the connection lines of the plurality of connection lines via the bridge circuit, so whether or not all the lightning arresters connected to all the connection lines include a deteriorated lightning arrester. Can be determined. In addition, when one of the plurality of connection lines is selected in a state where the load cell is separated and separated from the plurality of connection lines, a deteriorated lightning arrester is connected to the lightning arrester connected to the selected connection line. It can be determined whether or not it is included, that is, it can be determined whether there is a lightning arrester deteriorated for each connection line. Further, when one of the plurality of connection lines is selected in a state where the cable constituting the main part of the connection line is disconnected, the part other than the cable constituting the main part of the selected connection line, for example, the measurement It is possible to determine whether or not the lightning protection element connected to the connection terminal portion of the device has deteriorated.

  That is, by detecting deterioration in different connection states such as a state where the load detector is connected, a state where the load detector is disconnected, and a state where the cable constituting the main part of the connection line is disconnected, It becomes possible to narrow down the range of the lightning protection elements to be detected, and to identify the finally deteriorated lightning protection elements.

  Therefore, when a phenomenon such as the measurement value becoming unstable occurs, even if there is no insulation resistance meter, the deteriorated lightning arrester is identified, and the weighing device is restored by replacing the identified lightning arrester with a new one. Can be made.

  Moreover, in the insulation resistance meter, it is necessary to measure the insulation resistance for each of the lightning protection elements of the plurality of lightning protection elements to determine the presence or absence of deterioration, but according to this embodiment, if the deterioration is detected in different connection states, Well, the time required to restore the weighing device can be shortened.

  The different connection states are not limited to the state in which the load detector is connected, the state in which the load detector is disconnected, or the state in which the cable constituting the main part of the connection line is disconnected. It is good also as another connection state according to the number.

  In addition, as described above, in a state where the load cell that is a load detector is connected to the weighing device via a plurality of connection lines, by detecting deterioration, all the load cells that are connected to the plurality of connection lines are detected. Since it is possible to determine whether or not a lightning arrester element is included in the lightning arrester, self-diagnosis is performed to determine whether or not a lightning arrester element that has deteriorated is included before the weighing operation, for example, when the power is turned on. It becomes possible.

  In another embodiment of the present invention, an operation guide unit that guides an operation procedure for specifying a deteriorated lightning arrester according to a determination result of the determination unit by at least one of display output and audio output. May be included.

  By detecting the deterioration in different states such as the state in which the load detector is connected as described above, the state in which the load detector is disconnected, and the state in which the cable constituting the main part of the connection line is disconnected. By narrowing down the range of lightning protection elements to be detected, it is possible to identify the finally deteriorated lightning protection elements. According to this embodiment, the operation instructions such as disconnecting the load detector and disconnecting the cable are displayed. By guiding by voice or voice, it is possible to identify a lightning arrester that has deteriorated smoothly.

( 2 ) In another preferred embodiment of the weighing device of the present invention, the load detector and the plurality of connection lines are either connected / disconnected between the load detector and the plurality of connection lines. Switching means for switching to such a state is provided, and further includes a control unit for controlling switching by the switching means.

  According to this embodiment, since the control unit can control the switching means to switch connection / disconnection between the load detector and the plurality of connection lines, the operator can connect the load detector to the plurality of connection lines. It is possible to detect deterioration in different connection states without disconnecting from or connecting to.

  In another embodiment of the present invention, the switching means is added at a different position depending on the connection point of the lightning arrester, for example, between the cable constituting the main part of the connection line and the measuring device, and the control unit The switching may be controlled.

  In another embodiment of the present invention, the control unit may be provided on the load detector side instead of the weighing device side, or may be provided in the vicinity of the switching means.

( 3 ) The load detector of the present invention is a load detector that is connected to the weighing device via a plurality of connection lines, converts the load into an electrical signal, and outputs the electric signal to the weighing device. A plurality of lightning protection elements are connected to the connection line, and provided with deterioration detection means for detecting deterioration of the lightning protection elements , wherein the deterioration detection means selects each connection line of the plurality of connection lines individually. A voltage application unit that applies a voltage to the connection line selected by the selection unit, a voltage measurement unit that measures a voltage value based on a combined resistance value on the connection line side to which the voltage is applied by the voltage application unit, and a measurement The determination part which determines the presence or absence of the lightning arrester in which insulation resistance deteriorated based on the voltage value which performed is comprised.

  According to the load detector of the present invention, since it includes the deterioration detecting means for detecting the deterioration of the lightning arrester connected to the plurality of connection lines with the weighing device, the lightning arrester of the lightning arrester can be provided without an insulation resistance meter. Degradation can be detected. For example, when a phenomenon such as an unstable measurement value occurs, the degradation detection means determines whether the cause is due to degradation of the lightning protection element. It is possible to check whether or not the lightning protection element is deteriorated by the deterioration detecting means before starting the weighing operation.

( 4 ) The weighing system of the present invention is connected to the load detector for converting a load into an electrical signal, a plurality of connection lines to which lightning protection elements are connected, and the load detector via the plurality of connection lines. And a weighing device that processes an electrical signal from the load detector and measures an object to be weighed, wherein a plurality of lightning protection elements are connected to the plurality of connection lines. The measuring device or the measuring device comprises a deterioration detecting means for detecting deterioration of the lightning protection element, the deterioration detecting means comprising: a selecting section that individually selects each connection line of the plurality of connecting lines; and the selecting section A voltage application unit that applies a voltage to the selected connection line, a voltage measurement unit that measures a voltage value based on a combined resistance value on the connection line side to which a voltage is applied by the voltage application unit, and a voltage value based on the measured voltage value. Te, and a determination unit for determining presence or absence of a lightning protection device insulation resistance is deteriorated.

  According to the weighing system of the present invention, the load detector or the weighing device includes the deterioration detecting means for detecting the deterioration of the lightning protection elements connected to the plurality of connection lines. For example, when a phenomenon such as the measurement value becoming unstable occurs, the deterioration detection means determines whether or not the cause is due to deterioration of the lightning protection element. It is possible to check whether or not the lightning protection element is deteriorated by the deterioration detecting means before starting the weighing operation.

( 5 ) A method for detecting the deterioration of a lightning arrester according to the present invention includes a load detector for converting a load into an electrical signal, a load detector connected to the load detector via a plurality of connection lines, and a connection from the load detector. A method of detecting deterioration of the lightning arrester in a measuring system comprising a weighing device that processes an electrical signal and measures an object to be weighed, and a plurality of lightning arresters connected to the plurality of connection lines, A selection step for individually selecting each connection line of the plurality of connection lines, a voltage application step for applying a voltage to the selected connection line, and a voltage value based on a combined resistance value on the connection line side to which the voltage is applied And a determination step of determining the presence / absence of a lightning arrester having a deteriorated insulation resistance based on the measured voltage value.

  According to the lightning arrester degradation detection method of the present invention, each connection line is individually selected in the selection step, a voltage is applied to the connection line selected in the voltage application step, and the voltage is applied in the measurement step. Since the voltage value based on the resistance value is measured, and the presence or absence of the lightning protection element whose insulation resistance has deteriorated is determined based on the voltage value measured in the determination step, the lightning protection connected to the connection line for each selected connection line Whether or not the element has deteriorated can be determined.

  Therefore, for example, when a load cell that is a load detector is connected to a weighing device via a plurality of connection lines, if one of the plurality of connection lines is selected, the selected connection line is Since it is connected to all the connection lines of the plurality of connection lines via the bridge circuit, it is determined whether or not a deteriorated lightning protection element is included in all the lightning protection elements connected to all the connection lines. It can be judged. In addition, when one of the plurality of connection lines is selected in a state where the load cell is separated and separated from the plurality of connection lines, a deteriorated lightning arrester is connected to the lightning arrester connected to the selected connection line. It can be determined whether or not it is included, that is, it can be determined whether there is a lightning arrester deteriorated for each connection line. Further, when one of the plurality of connection lines is selected in a state where the cable constituting the main part of the connection line is disconnected, the part other than the cable constituting the main part of the selected connection line, for example, the measurement It is possible to determine whether or not the lightning protection element connected to the connection terminal portion of the device has deteriorated.

  That is, by detecting deterioration in different connection states such as a state in which the load detector is connected, a state in which the load detector is disconnected, and a state in which the cable constituting the main part of the connection line is disconnected, It becomes possible to narrow down the range of the lightning protection elements to be detected, and to identify the finally deteriorated lightning protection elements.

  Therefore, when a phenomenon such as the measurement value becoming unstable occurs, even if there is no insulation resistance meter, the deteriorated lightning arrester is identified, and the weighing device is restored by replacing the identified lightning arrester with a new one. Can be made.

  Moreover, in the insulation resistance meter, it is necessary to measure the insulation resistance for each of the lightning protection elements of the plurality of lightning protection elements to determine the presence or absence of deterioration, but according to this embodiment, if the deterioration is detected in different connection states, Well, the time required to restore the weighing device can be shortened.

  In addition, as described above, in a state where the load cell that is a load detector is connected to the weighing device via a plurality of connection lines, by detecting deterioration, all the load cells that are connected to the plurality of connection lines are detected. Since it is possible to determine whether or not a lightning arrester element is included in the lightning arrester, self-diagnosis is performed to determine whether or not a lightning arrester element that has deteriorated is included before the weighing operation, for example, when the power is turned on. It becomes possible.

  According to the present invention, it is possible to detect the deterioration of the lightning protection element without an insulation resistance meter. For example, when a phenomenon such as the measurement value becoming unstable occurs, the cause is detected by the deterioration detecting means. It is possible to determine whether or not the lightning arrester is caused by deterioration, or before starting the weighing operation, it is possible to check whether or not the lightning arrester is deteriorated by the deterioration detecting means. .

  Further, according to the lightning arrester deterioration detection method of the present invention, each connection line is selected, and the presence or absence of a deteriorated lightning arrester is determined based on the voltage value of the combined resistance value on the selected connection line side. Since it can be determined for each connection line whether or not the lightning arrester connected to the connection line has deteriorated, the deteriorated lightning arrester can be identified by detecting the deterioration in different connection states.

FIG. 1 is a configuration diagram of a weighing system including a weighing device according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a main part of FIG. FIG. 3 is an equivalent circuit diagram showing a connection state of the strain gauge and the lightning arrester. FIG. 4 is an equivalent circuit diagram corresponding to FIG. FIG. 5 is a configuration diagram of a main part showing a state in which the load cell is separated. FIG. 6 is a configuration diagram of a main part showing a state where the relay cable is disconnected. FIG. 7 is a flowchart showing a procedure for detecting deterioration of the lightning protection element. FIG. 8 is a configuration diagram of a weighing system including a load detector according to another embodiment of the present invention. FIG. 9 is a configuration diagram of a main part corresponding to FIG. 2 according to another embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing the overall configuration of a weighing system according to an embodiment of the present invention.

  The weighing system of this embodiment includes a load cell 1 serving as a load detector that detects a load on a platform (not shown) on which a vehicle such as a truck is mounted, and a weighing connected to the load cell 1 via a long relay cable 2. An indicator 3 as a device is provided.

  The load cell 1 includes four first to fourth strain gauges R1 to R4 of strain generating bodies disposed on the above-described table, and a Wheatstone bridge circuit is configured by these strain gauges R1 to R4.

Input 4 and 5 of the Wheatstone bridge circuit, the junction box 6 and a power relay cable 2 _2, 2 ₅ via respective indicator 3 of the second is connected to the fifth connection terminal 7 _2, 7 ₅ In order to detect a voltage drop caused by the power supply relay cables 2 ₂ and ₂₅ , the third and sixth connection terminals 7 ₃ and 7 ₃ of the indicator 3 are connected to the connection box 6 and the sensing relay cables 2 ₃ and 2 ₆ , respectively. 7 is connected to ₆ . The output terminals 8 and 9 of the Wheatstone bridge circuit are connected to the first and fourth connection terminals 7 ₁ and 7 ₄ of the indicator 3 via the connection box 6 and the signal relay cables 2 ₁ and 2 ₄ , respectively. .

The indicator 3 includes a weighing A / D converter 10 connected to the first to sixth connection terminals 7 _{1 to} 7 ₆ , a CPU 11 that performs calculation of a measured value and controls each unit, a program, and the like. A stored memory 12, a key operation unit 13 for performing various settings, a display unit 14 for displaying a measurement value, and a measurement unit 15 for performing measurement for detecting deterioration described later are provided.

When weighing a vehicle such as a truck mounted on a mounting table, the weighing A / D converter 10 of the indicator 3 is connected to the input terminal 4 of the load cell 1 via the power supply relay cables 2 ₂ and 2 ₅ and the connection box 6. 5, a bridge voltage is applied, and an analog load signal from the output terminals 8 and 9 of the load cell 1 and an analog sensing signal from the input terminals 4 and 5 are connected to the junction box 6 and the signal relay cables 2 ₁ and 2. ₄ and the sensing relay cables 2 ₃ and 2 ₆ , converted into digital signals, and output to the CPU 11. Based on the input digital signal, the CPU 11 calculates the mass value of the vehicle on the platform and displays it on the display unit 14. The operation at the time of the above weighing is the same as the conventional one.

In the weighing system of this embodiment, in order to protect the load cell 1 and the indicator 3 connected by the relay cable 2 constituting a plurality of connection lines from surges, the connection box 6 and the indicator 3 in the vicinity of the load cell 1 are protected. Are connected to lightning protection devices Z _{L1 to} Z _L4 and Z _{I1 to} Z _I6 , respectively.

That is, the lightning protection elements Z _L1 and Z _L3 and the lightning protection elements Z _L2 and Z between the signal relay cables 2 ₁ and 2 ₄ and the power supply relay cables 2 ₂ and 2 ₅ in the junction box 6 and the ground (PE). Each _L4 is inserted. The sensing relay cables 2 ₃ and 2 ₆ are short-circuited to the power relay cables 2 ₂ and 2 ₅ on the load cell 1 side and have the same potential, and thus no lightning protection elements are provided. Further, in the indicator 3, between each connection line from the _first to sixth connection terminals 7 _{1 to} 7 ₆ of the indicator 3 to the measuring A / D converter 10 and the ground (PE), Lightning arresters Z _{I1 to} Z _I6 are respectively inserted.

Thus, the lightning arresters Z _{L1 to} Z _L4 and Z _{I1 to} Z _I6 are connected to the plurality of connection lines from the load cell 1 to the metering A / D converter 10 of the indicator 3, and the lightning arrester Z by _{L1 ~Z L4, Z I1 ~Z I6} , so as to protect the load cell 1 and the indicator 3 to absorb a surge voltage due to lightning.

  Needless to say, the number of lightning protection elements and the connection locations are not limited to this embodiment.

The present embodiment is configured as follows so that the lightning arresters Z _{L1 to} Z _L4 and Z _{I1 to} Z _I6 can be detected even without an insulation resistance meter.

That is, the indicator 3 includes a measurement unit 15 for detecting deterioration connected to each connection line of the _first to sixth connection terminals 7 _{1 to} 7 ₆ , similarly to the A / D conversion unit 10 for measurement. The measurement unit 15 measures the voltages corresponding to the insulation resistances of the lightning protection devices Z _{L1 to} Z _L4 and Z _{I1 to} Z _I6 as described later. The measurement unit 15, the CPU 11, and the memory 12 constitute a deterioration detection unit that detects the deterioration of the lightning protection devices Z _{L1 to} Z _L4 and Z _{I1 to} Z _I6 .

  FIG. 2 is a diagram illustrating the configuration of the measurement unit 15 in FIG. 1. In FIG. 2, the above-described measurement A / D conversion unit 10 and CPU 11 are omitted.

Measuring unit 15 is provided with first to sixth switch SW1~SW6 as a selection unit off is controlled by the CPU11 of the above, one end of each switch SW1~SW6 are first to sixth connection terminals _{7 1 7-6} are connected, the other end is connected in common to one input terminal 16a of the amplifier 16. The other input terminal 16b of the amplifier 16 is grounded (PE). Also, one input terminal 16a of the amplifier 16 is connected to the power source Vc + via a seventh switch SW7 whose on / off is controlled by the CPU 11 and the resistor Rc1, and the other input terminal 16b is on / off controlled by the CPU 11. The eighth switch SW8 and the resistor Rc2 are connected to the power source Vc−. The seventh and eighth switches SW7 and SW8, the resistors Rc1 and Rc2, and the power sources Vc + and Vc− constitute a voltage application unit.

The output of the amplifier 16 is supplied to the A / D conversion circuit 17 and converted into a digital signal. The digital signal from the A / D conversion circuit 17 is supplied to the CPU 11 described above, and the CPU 11 as a determination unit determines whether or not the lightning protection elements Z _{L1 to} Z _L4 and Z _{I1 to} Z _I6 are deteriorated.

In this embodiment, when detecting the deterioration of the insulation resistance of the lightning protection elements Z _{L1 to} Z _L4 and Z _{I1 to} Z _I6 , the key operation unit 13 in FIG. 1 described above is operated to switch from the measurement mode to the deterioration detection mode. Switch.

This deterioration detection mode, metering A / D converter 10 of FIG. 1 is disconnected from the first to sixth connection terminals ₇ 1-7 ₆ by the built-in switch, the first to sixth connection terminals ₇ 1-7 ₆ and the measurement A / D converter 10 are internally disconnected.

In the degradation detection mode in which the A / D conversion unit 10 for measurement is disconnected from the _first to sixth connection terminals 7 _{1 to} 7 ₆ , the CPU 11 in FIG. 1 performs the first switch SW 1 and the first switch SW 1 of the measurement unit 15 shown in FIG. 7, the eighth switch SW7,8 on, the voltage for insulation resistance measurement is applied, measuring the voltage between the ₁ and the first connection terminal 7 and earth (PE).

The first to the connection state of the fourth strain gauges R1~R4 lightning arrester element _{Z L1 ~Z L4, Z I1 ~Z} I6 and load cell 1 at this time can be represented by the equivalent circuit diagram of FIG. Here, the resistance value of the first to fourth strain gauges R1 to R4 R1 to R4, the resistance value of the lightning protection device _{Z L1 ~Z L4, Z I1 ~Z} I6 and _{Z L1 ~Z L4, Z I1 ~Z} I6 To do.

In FIG. 3, the combined resistance of the first portion P1 surrounded by the virtual line is
{R1 × (R2 + R3 + R4)} / {R1 + (R2 + R3 + R4)}
If R1 = R2 = R3 = R4 = R, then
{R × (3R)} / {R + (3R)} = {R × (3R)} / 4R = (3/4) R.

The combined resistance of the second portion P2 surrounded by the virtual line is
{(R1 + R2) × (R3 + R4)} / {(R1 + R2) + (R3 + R4)}
If R1 = R2 = R3 = R4 = R, then
(2R × 2R) / (2R + 2R) = (2R × 2R) / 4R = R.

  The combined resistance of the third portion P3 surrounded by the imaginary line is calculated in the same manner as the first portion P1, and becomes (3/4) R.

The combined resistance of the fourth portion P4 surrounded by the virtual line is
( _ZL1 * _ZI2 * _ZI3 ) / {( _ZI2 * _ZI3 ) + ( _ZL1 * _ZI3 ) + ( _ZL1 * _ZI2 )}.

The combined resistance of the fifth portion P5 surrounded by the virtual line is
(Z _L3 × Z _I4 ) / (Z _L3 + Z _I4 ).

The combined resistance of the sixth portion P6 surrounded by the virtual line is
( _ZL4 + _ZI5 + _ZI6 ) / {( _ZI5 * _ZI6 ) + ( _ZL4 * _ZI6 ) + ( _ZL4 + _ZI5 )}.

  Therefore, the equivalent circuit diagram of FIG. 3 becomes like the equivalent circuit diagram shown in FIG. 4, and the amplifier 16 of the measurement unit 15 measures the voltage based on the combined resistance value on the connection line side shown in FIG. This measurement voltage is supplied to the CPU 11 via the A / D conversion circuit 17.

In this case, although the measurement precision insulation resistance of the lightning protection element _{Z L1 ~Z L4, Z I1 ~Z} I6 can not perform, even one of the lightning protection device _{Z L1 ~Z L4, Z I1 ~Z} I6 insulation When the resistance is deteriorated, the combined resistance value is affected. Therefore, it is possible to determine the presence or absence of deterioration relative to the value before the deterioration.

Therefore, in this embodiment, whether or not the deteriorated lightning protection element is included in the lightning protection elements Z _{L1 to} Z _L4 and Z _{I1 to} Z _I6 in the memory 12 in the indicator 3 shown in FIG. A threshold value for determining whether or not is stored in the memory 12 in advance.

This threshold value is determined in advance based on a voltage value corresponding to the combined resistance of FIG. 4 when the lightning protection devices Z _{L1 to} Z _L4 and Z _{I1 to} Z _I6 are not deteriorated, for example, at the time of factory shipment. Is done.

In CPU 11, that the voltage value between the first connecting terminal ₇₁ and the ground measured to determine whether it exceeds the threshold value stored in the memory 12, lightning protection element Z _L1 to Z _L4, Z _I1 to Z in _I6, whether contains deteriorated lightning protection device, i.e., it is possible to detect whether the arrester element _{Z L1 ~Z L4, Z I1 ~Z} I6 is deteriorated.

When it is detected that the lightning arresters Z _{L1 to} Z _L4 and Z _{I1 to} Z _I6 have deteriorated, which lightning arrester has deteriorated, that is, the deteriorated lightning arrester is specified as follows. .

In this case, when the CPU 11 detects that the lightning protection elements Z _{L1 to} Z _L4 and Z _{I1 to} Z _I6 have deteriorated, the display instructing the display unit 14 in FIG. 1 to disconnect the load cell 1 is displayed. I do.

  Therefore, the operator disconnects the load cell 1 from the connection box 6 and disconnects it from the indicator 3, and then operates the key operation unit 13 to input that it has been disconnected to the indicator 3.

  FIG. 5 is a view corresponding to FIG. 2 described above, showing a state in which the load cell 1 is disconnected from the indicator 3.

  When it is input by operating the key operation unit 13 that the load cell 1 has been disconnected, the CPU 11 turns on the first to sixth switches SW1 to SW6 in order with the seventh and eighth switches SW7 and 8 turned on. Turn on to select each connection line individually and measure the voltage of each connection line in turn to detect the presence or absence of deterioration.

First, by turning on the first switch SW1, detecting the presence or absence of degradation by measuring a voltage corresponding to the insulation resistance of the lightning protection element Z _L1, Z _I1 connected to the signal junction cable 2 ₁ connection line To do. In the same manner as described above, the presence / absence of this deterioration is also compared with a threshold value stored in advance in the memory 12, and the deterioration of the lightning arresters Z _{L1 and} Z _I1 is determined depending on whether or not the measured voltage exceeds the threshold value. Detect the presence or absence. This threshold value is also determined based on the voltage at the time of factory shipment, which is normal.

Then, by turning on the second switch SW2, similarly detected the presence or absence of degradation of the arrester element Z _L2, Z _I2 which is connected to the power supply junction cable 2 _second connection lines.

Then, by turning on the third switch SW3, similarly detected whether the deterioration of the arrester element Z _I3 which is connected to the connection line of the sensing power cable 2 _3.

Then, by turning on the fourth switch SW4, to detect the presence or absence of degradation of the arrester element Z _L3, Z _I4 connected to the connection line of the signal relay cable 2 ₄ Similarly.

Next, by turning on the fifth switch SW5, the presence or absence of deterioration of the lightning arresters Z _L4 and Z _I5 connected to the connection line of the power supply relay cable ₂₅ is similarly detected.

Next, by turning on the sixth switch SW6, the presence or absence of deterioration of the lightning arrester Z _I6 connected to the connection line of the sensing relay cable ₂₆ is similarly detected.

Furthermore, by measuring the voltage in a state shown in FIG. 5, one of the degradation of the arrester element Z _L1, Z _I1 connected to the signal junction cable 2 ₁ connection line, the power relay cable 2 ₂ any degradation, or deterioration of the arrester element Z _L3, Z _I4 connected to the connection line of the signal relay cable 2 ₄ arrester element Z _L2, Z _I2 which is connected to the connection line, or the power supply When one of the lightning arresters Z _L4 and Z _I5 connected to the connection line of the relay cable ₂₅ is detected, the deteriorated lightning arrester is identified as follows.

  That is, the CPU 11 performs a display for instructing the display unit 14 to disconnect the relay cable 2 to which the lightning protection element whose deterioration has been detected is connected.

  Therefore, the operator disconnects the corresponding relay cable 2 from the indicator 3 and then operates the key operation unit 13 to input to the indicator 3 that it has been disconnected.

  FIG. 6 is a view corresponding to FIG. 5 in a state where the relay cable 2 is disconnected.

The CPU 11 turns on the first, second, fourth, and fifth switches SW1, 2, 4, and 5 in order and measures the voltage in the state where the relay cable 2 is disconnected as described above, whereby the connection box 6 It is possible to identify whether the lightning arresters Z _{L1 to} Z _L4 installed in the terminal are deteriorated or the lightning arresters Z _{I1 to} Z _I6 in the indicator 3 are deteriorated.

Note that whether or not the lightning arresters Z _{I1 to} Z _I6 are deteriorated is determined by comparison with a threshold value stored in advance in the memory 12 in the indicator 3 as described above. This threshold is determined based on the voltage value at the time of factory shipment, which is normal.

  As described above, a series of operations are performed according to the guidance display on the display unit 14 as the operation guidance unit of the indicator 3. Further, the measurement value at that time is stored in the memory 12. As a result, the indicator 3 comprehensively determines, specifies the deteriorated lightning arrester, and displays the result on the display unit 14. Therefore, the operator can easily restore the weighing system by grasping the deteriorated lightning protection element by looking at the display on the display unit 14 and replacing the lightning protection element with a new lightning protection element.

  FIG. 7 is a flowchart showing the above-described procedure for detecting deterioration.

  In the measurement mode, a measurement screen including a measurement value is displayed on the display unit 14. When detecting the deterioration of the lightning arrester, the key operation unit 13 of the indicator 3 is operated to shift from the measurement mode to the deterioration detection mode, and a display menu is displayed on the display unit 14 (step n1). ).

  Next, voltage measurement corresponding to the insulation resistance is started by a key operation for starting measurement (step n2). In this measurement, in the state shown in FIG. 2, the first, seventh, and eighth switches SW1, 7, and 8 are turned on to measure the voltage corresponding to the insulation resistance (step n3).

  The measured voltage value and the threshold value stored in the memory 12 in advance are compared to determine the presence or absence of a deteriorated lightning protection element (step n4). When there is no deteriorated lightning protection element, the display unit 14 indicates that it is normal. Display and finish (step n5).

  When there is a deteriorated lightning protection device, the display unit 14 is displayed to indicate that it is abnormal and that a key operation is required to specify whether or not the deteriorated lightning protection device (abnormal part) is specified (step n6).

  Next, based on the key operation performed by the operator, it is determined whether or not the deteriorated lightning protection element is specified (step n7). When specifying, the display unit 14 is instructed to detach the load cell 1 to the state shown in FIG. 5 and to request a key operation indicating that the preparation is completed after the detachment (step n8). ).

  Next, it is determined whether or not a key operation indicating that the preparation has been completed is performed (step n9). When the key operation is performed, both the seventh and eighth switches SW7 and SW8 are turned on in the state shown in FIG. In addition to turning on, the first to sixth switches SW1 to SW6 are sequentially turned on to measure the voltage corresponding to the insulation resistance and store the measured value (step n10).

  Next, the relay cable 2 is instructed to be disconnected and brought into the state of FIG. 6 described above, and the display unit 14 is displayed to request a key operation indicating that the preparation has been completed after the disconnection (step n11). ).

  Next, it is determined whether or not a key operation indicating whether or not preparation has been completed (step n12). When completed, the seventh and eighth switches SW7 and SW8 are turned on in the state shown in FIG. While both are turned on, the first, second, fourth and fifth switches SW1, 2, 4 and 5 are switched on in order, the voltage corresponding to the insulation resistance is measured, and the measured value is stored (step n13). .

  By comparing the voltage value stored in step n10 and step n13 described above with the threshold value stored in the memory 12 in advance, a deteriorated lightning protection element is specified, and a screen display for specifying the deteriorated lightning protection element is displayed on the display unit 14 ( Step n14).

  The operator replaces the deteriorated lightning arrester with a new lightning arrester by looking at the display on the display unit 14, and restores the weighing system.

In this embodiment, the key operation unit 13 is operated to shift to the deterioration detection mode. However, as another embodiment of the present invention, for example, when the power is turned on, the above-described steps n3 and n4 are automatically executed to prevent lightning. Self-diagnosis may be performed to determine whether or not a deteriorated lightning arrester is included in the elements Z _{L1 to} Z _L4 and Z _{I1 to} Z _I6 , and normality and abnormality may be displayed on the display unit 14. Thus, the operator can confirm the presence or absence of deterioration of the lightning arresters Z _{L1 to} Z _L4 and Z _{I1 to} Z _I6 before starting the work. In this way, the deteriorated lightning protection element can be identified and replaced with a new lightning protection element, and the weighing operation can be started.

(Embodiment 2)
In the above-described embodiment, the deterioration detecting means for detecting the deterioration of the lightning protection element is provided on the indicator 3 side. However, as another embodiment of the present invention, as shown in FIG. 8, the deterioration detecting means is provided on the load cell side. May be.

That is, the load cell 1a of this embodiment incorporates the ninth to fourteenth switches SW9 to SW14 for connecting to or disconnecting the above-described relay cables 2 ₁ to ₂₆ and the relay cables 2 ₁ to _26. And 15th to 20th switches SW15 to 20 as selection units for individually selecting the connection lines.

  Further, as voltage application units for applying a voltage to the connection lines selected by the 15th to 20th switches SW15 to 20th, the seventh and eighth switches SW7 and 8, resistors Rc1 and Rc2, and power sources Vc + and Vc−. And an amplifier 16 for measuring a voltage based on a combined resistance value on the connection line side when a voltage is applied, and an A / D conversion circuit 17 for A / D converting the output of the amplifier and supplying it to the CPU 20. .

CPU20, each switch SW9~SW14 above, controls the on-off of SW15～20, like the CPU11 of the above-described embodiment, the presence or absence of degradation of the arrester element _{Z L1 ~Z L4, Z I1 ~Z} I6 judge. The memory 21 stores a program, a threshold value, and the like, and the display unit 22 displays an operation procedure, a connection portion of a deteriorated lightning arrester, and the like.

On the other hand, in the indicator 3a, the measurement unit 15 described above is omitted, and the first to sixth switches SW21 to 26 are provided between the _first to sixth connection terminals 7 _{1 to} 7 ₆ and the A / D conversion unit 10 for measurement. SW26 is provided, and these switches SW21 to SW26 are all turned on in the normal measurement mode, and in the deterioration detection mode, all of them can be turned off by operating a setting switch (not shown) of the weighing device 3a. it can.

  In the normal weighing mode, the ninth to fourteenth switches SW9 to SW14 of the load cell 1a are all turned on, and the fifteenth to twentieth switches SW15 to SW20 are all turned off. On the other hand, the 21st to 26th switches SW21 to SW26 of the indicator 3a are all turned on.

In this weighing mode, the weighing A / D converter 10 of the indicator 3 a applies a bridge voltage to the input terminals 4 and 5 of the load cell 1 via the power supply relay cables 2 ₂ and 2 ₅ and the connection box 6. The analog load signal from the output terminals 8 and 9 of the load cell 1 and the analog sensing signal from the input terminals 4 and 5 are connected to the junction box 6, the signal relay cables 2 ₁ and 2 ₄ and the sensing relay cable 2 _3. takes over the _{2 6,} and outputs the CPU11a is converted into a digital signal. The CPU 11a calculates the mass value of the vehicle on the platform based on the input digital signal and displays it on the display unit 14a. The operation at the time of the above weighing is the same as the conventional one.

In this embodiment, when detecting deterioration of the arrester element _{Z L1 ~Z L4, Z I1 ~Z} I6 is indicator 3a first 21 to second 26 switch by operating the above-described setting switch (not shown) of the SW21~SW26 all is turned off, disconnecting the metering a / D converter 10 from the first to sixth connection terminals ₇ 1-7 _6.

In this state, the key operation unit 23 of the load cell 1a is operated to shift to the deterioration detection mode. In this deterioration detection mode, the CPU 20 turns on the fifteenth switch SW15, the seventh, and eighth switches SW15, 7, and 8 while applying all voltages while keeping all the ninth to fourteenth switches SW9 to SW14 on. to measure the voltage by the amplifier 16, CPU 20 may determine in the same manner as in the embodiment described above, in the lightning protection device _{Z L1 ~Z L4, Z I1 ~Z} I6, whether contains deteriorated arrester elements To do.

  If a deteriorated lightning protection element is included, the CPU 20 turns off all the ninth to fourteenth switches SW9 to SW14 and disconnects the Wheatstone bridge circuit of the load cell.

  In this state, the CPU 20 turns on the seventh and eighth switches SW7 and SW8, turns on the fifteenth to twentieth switches SW15 to SW20 in order, individually selects the connection lines, and deteriorates for each connection line. It is determined whether or not a lightning protection element is included.

  Thereafter, the CPU 20 instructs the display unit 22 to disconnect the indicator 3a, detects a lightning arrester that has deteriorated in a state in which the indicator 3a is disconnected, and thus deteriorated, as in the above-described embodiment. A lightning protection element, that is, an abnormal part can be identified. The CPU 20 displays the identified abnormal location on the display unit 14a.

(Embodiment 3)
In each of the above-described embodiments, the load cell 1, the relay cable 2, or the indicator 3a is disconnected and connected by an operator. However, in other embodiments of the present invention, it can be automatically disconnected and connected. It may be.

  FIG. 9 is a configuration diagram of a main part corresponding to FIG. 2 described above according to another embodiment of the present invention.

In this embodiment, each of the relay cables 2 ₁ to ₂₆ between the load cell 1 and the connection box 6 is provided with a first switch group 31 as a switching unit including 27th to 32nd switches SW27 to SW32. Each of the relay cables 2 ₁ to ₂₆ between the junction box 6 and the indicator 3 is provided with a second switch group 32 as switching means including 33rd to 38th switches SW33 to SW38.

  Further, on / off of each of the switches SW27 to SW32 and SW33 to SW38 of these switch groups 31 and 32 is controlled via a control line (not shown) as a control unit in FIG.

According to such a configuration, the CPU 11 controls the on / off of each of the switches SW27 to SW32 of the first switch group 31, thereby connecting the load cell 1 and the plurality of relay cables 2 ₁ to ₂₆ connected to the indicator 3. The connection box 6 provided with the lightning protection elements Z _{L1 to} Z _L4 can be switched / disconnected (disconnected) and the CPU 11 controls the on / off of the switches SW33 to SW38 of the second switch group 32. The connection / disconnection (disconnection) of the plurality of relay cables 2 ₁ to ₂₆ connected to the indicator 3 can be switched.

  This eliminates the need for the operator to disconnect the load cell 1 from the indicator 3 or to detect the deterioration by disconnecting the relay cable 2 from the indicator 3, and the CPU 11 automatically switches to a different connection state to deteriorate the lightning protection element. Can be detected.

  The present invention is useful for detecting deterioration of a lightning protection element attached to a plurality of connection lines connecting a load detector and a weighing device.

1,1a Load cell (load detector)
2 Relay cable 2 ₁ , 2 ₄ Signal relay cable 2 ₂ , 2 ₅ Relay cable for power supply 2 ₃ , 2 ₆ Relay cable for sensing ₃ , 3 a Indicator (metering device)
6 Junction box 7 _{1 to} 7 ₆ 1st to 6th connection terminal 10 A / D converter for weighing 11, 20 CPU
12, 21 Memory 14, 22 Display unit 15 Measurement unit

Claims (5)

A weighing device that is connected to a load detector that converts a load into an electrical signal through a plurality of connection lines and that processes an electrical signal from the load detector to measure an object to be weighed,
A plurality of lightning protection elements are connected to the plurality of connection lines,
Comprising a deterioration detecting means for detecting deterioration of the lightning protection element ,
The deterioration detecting means includes
A selection unit that individually selects each connection line of the plurality of connection lines;
A voltage application unit for applying a voltage to the connection line selected by the selection unit;
A voltage measuring unit for measuring a voltage value based on a combined resistance value on a connection line side to which a voltage is applied by the voltage applying unit;
Based on the measured voltage value, a determination unit that determines the presence or absence of a lightning protection element having a deteriorated insulation resistance;
A weighing apparatus comprising: Between the load detector and the plurality of connection lines, switching means for switching the load detector and the plurality of connection lines to any state of connection / disconnection is provided,
A control unit for controlling switching by the switching means;
The weighing device according to claim 1, further comprising: A load detector connected to the weighing device via a plurality of connection lines, converting a load into an electric signal and outputting the electric signal to the weighing device,
A plurality of lightning protection elements are connected to the plurality of connection lines,
Comprising a deterioration detecting means for detecting deterioration of the lightning protection element,
The deterioration detecting means includes
A selection unit that individually selects each connection line of the plurality of connection lines;
A voltage application unit for applying a voltage to the connection line selected by the selection unit;
A voltage measuring unit for measuring a voltage value based on a combined resistance value on a connection line side to which a voltage is applied by the voltage applying unit;
Based on the measured voltage value, a determination unit that determines the presence or absence of a lightning protection element having a deteriorated insulation resistance;
A load detector comprising: A load detector that converts a load into an electrical signal, a plurality of connection lines to which lightning protection elements are connected, and the load detector connected to the load detector via the plurality of connection lines, and an electric power from the load detector A weighing system comprising a weighing device for processing a signal and weighing an object to be weighed, wherein a plurality of lightning protection elements are connected to the plurality of connection lines,
The load detector or the weighing device comprises a deterioration detecting means for detecting deterioration of the lightning protection element,
The deterioration detecting means includes
A selection unit that individually selects each connection line of the plurality of connection lines;
A voltage application unit for applying a voltage to the connection line selected by the selection unit;
A voltage measuring unit for measuring a voltage value based on a combined resistance value on a connection line side to which a voltage is applied by the voltage applying unit;
Based on the measured voltage value, a determination unit that determines the presence or absence of a lightning protection element having a deteriorated insulation resistance;
A weighing system comprising: A load detector that converts a load into an electrical signal, and a weighing device that is connected to the load detector via a plurality of connection lines and that processes an electrical signal from the load detector to measure an object to be weighed A method of detecting deterioration of the lightning arrester in a measuring system in which a plurality of lightning arresters are connected to the plurality of connection lines,
A selection step of individually selecting each connection line of the plurality of connection lines;
A voltage applying step for applying a voltage to the selected connection line;
A measurement step of measuring a voltage value based on a combined resistance value on the connection line side to which the voltage is applied;
A determination step of determining the presence or absence of a lightning protection element having a deteriorated insulation resistance based on the measured voltage value;
A method for detecting deterioration of a lightning arrester, comprising:

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