JP4873359B2 - Conveyor belt longitudinal crack detection device - Google Patents

Description

  The present invention relates to a conveyor belt longitudinal crack detection device for detecting longitudinal tears occurring in a conveyor belt in use.

  Conventionally, large-sized conveyor belts are used when conveying objects to be transported such as ores. When ore or the like is transported by such a conveyor belt, when the ore is thrown into the conveyor belt and dropped, or when the ore is transported, the conveyor belt is often damaged or longitudinally cracked.

  If the conveyor belt is torn in the vertical direction in this way, it will not only hinder the conveyance work but also suffer a great deal of damage.

  For this reason, the conveyor belt is provided with a longitudinal crack detection device that detects longitudinal tears. Various detection methods such as an exterior type and an interior type are known for detecting the vertical crack of such a conveyor belt.

  FIG. 10 is a configuration diagram illustrating an example of the above-described interior type longitudinal crack detection device. In the figure, reference numeral 1 denotes a conveyor device, which includes a drive pulley 2, a driven pulley 3, a conveyor belt 4 spanned between the drive pulley 2 and the driven pulley 3, and an electric motor 5 that rotates the drive pulley 2.

  In addition, as shown in FIG. 11, a plurality of detection objects are embedded in the conveyor belt 4 at predetermined equal intervals in the longitudinal direction. Two detection objects are embedded adjacent to the reference position of the conveyor belt 4 so that the reference position can be easily detected.

  The object to be detected is composed of, for example, a resonance circuit 6 including a coil 6a and a capacitor 6b, and a part of the conductive wire forming the coil 6a extends in the width direction of the conveyor belt 4 and is embedded in the conveyor belt 4. . The resonance frequency of the resonance circuit 6 is set to about 650 KHz.

  Further, the drive pulley 2 is provided with an encoder 7 from which N (N is a natural number) timing pulse signals TP are output at equal intervals during one rotation. The output timing of the timing pulse signal TP is set in synchronization with the movement of the resonance circuit 6 embedded in the conveyor belt 4.

  On the other hand, below the conveyor belt 4, three detectors 8a to 8c are fixedly arranged, and these detectors 8a to 8c are shifted little by little in the width direction of the conveyor belt 4 as shown in FIG. Has been placed.

  Each of these detectors 8a to 8c is provided with an antenna coil 81, an oscillation circuit 82, and a determination circuit 83 as shown in FIG. 13, from which an alternating current having a frequency of about 650 KHz is applied to the antenna coil 81. Have been supplied. Further, the determination circuit 83 receives the alternating current A supplied from the oscillation circuit 82 to the antenna coil 81 and the timing pulse signal TP output from the encoder 7, and the abnormality of the resonance circuit 6 is determined based on these signals. The presence / absence is determined, and an abnormality signal D is output when there is an abnormality.

  According to the conveyor belt longitudinal crack detection device having the above-described configuration, when the conveyor belt 4 is not longitudinally split, each resonance circuit 6 operates normally, and the resonance circuit 6 is provided on the detection units 8a to 8c. When positioned, the antenna coil 81 and the resonance circuit 6 are electromagnetically coupled. Thereby, since the energy radiated from the antenna coil 81 is absorbed by the resonance circuit 6, the level of the alternating current supplied to the antenna coil 81 is reduced, so that the normality of the resonance circuit 6 is confirmed.

  Further, when the conveyor belt 4 in use is longitudinally split due to the projections of fallen objects, the conductive wires constituting the coil 6a of the resonance circuit 6 embedded in the conveyor belt 4 are cut, and the resonance circuit 6 Does not operate, energy radiated from the antenna coil 81 is not absorbed by the resonance circuit 6. For this reason, since the level of the alternating current supplied to the antenna coil 81 does not decrease, an abnormality of the resonance circuit 6 is detected. Thereby, the longitudinal tearing of the conveyor belt is detected. When the vertical tear of the conveyor belt 4 is detected in this way, the abnormality signal D is output from the determination circuit 83 to the electric motor 5, and the electric motor 5 is stopped.

  Further, the conveyor belt 4 may be displaced in the width direction during conveyance. However, since the plurality of detection portions 8a to 8c are arranged as described above, the state of the resonance circuit 6 can be reliably detected. .

  As an example of the above-described apparatus, for example, a conveyor belt vertical crack detection apparatus disclosed in Japanese Patent Laid-Open No. 58-222001 (Patent Document 1), disclosed in Japanese Utility Model Laid-Open No. 59-108726 (Patent Document 2). A conveyor belt longitudinal crack detection device disclosed in JP-A-60-165540 (Patent Document 3), and disclosed in JP-A-61-018618 (Patent Document 4). Conveyor Belt Longitudinal Crack Detection Control Method and Control Device, Conveyor Belt Longitudinal Crack Detection Device Disclosed in Japanese Patent Laid-Open No. Sho 61-081315 (Patent Document 5) A conveyor belt longitudinal crack detection device disclosed in Document 6), a conveyor belt longitudinal crack detection device disclosed in Japanese Patent Laid-Open No. 6-048549 (Patent Document 7), and A conveyor belt longitudinal crack detection device disclosed in Japanese Patent No. 8-324752 (Patent Document 8), and a conveyor belt longitudinal crack detection device disclosed in Japanese Patent Laid-Open No. 11-208862 (Patent Document 9) are known. Yes.

  The conveyor belt vertical crack detection device disclosed in the above Japanese Patent Application Laid-Open No. 58-222001 (Patent Document 1) includes a coil, a lead wire, and a capacitor embedded in a cover rubber of the conveyor belt. In the conveyor belt vertical crack detection device that constitutes a resonant circuit for detecting vertical cracks, the coil is formed by winding a coil of a conductive wire inside the widthwise end of the conveyor belt and both ends of the coil. A vortex capacitor is embedded in parallel, and a plurality of lead wires are arranged in parallel in the width direction of the conveyor belt from the coil and the vortex capacitor, respectively, and the coil, the vortex capacitor, and a plurality of parallel lead wires are arranged. Thus, a resonant circuit for detecting a vertical crack is configured.

  The conveyor belt longitudinal crack detection device disclosed in Japanese Utility Model Laid-Open No. 59-108726 (Patent Document 2) has a coil in a desired position in the longitudinal direction of the conveyor belt in a direction perpendicular to the longitudinal direction of the conveyor belt. And a resonance circuit for detection composed of a capacitor and a lead wire connecting them, and a resonance circuit for mark composed of a coil and a capacitor is embedded adjacent to the detection resonance circuit, and the detection resonance circuit While the resonance frequency of the circuit and the mark resonance circuit are substantially matched, the coil center of the detection resonance circuit and the coil center of the mark resonance circuit are parallel to the traveling direction of the belt at the side end of the conveyor belt, and It is arranged so as to be positioned in a straight line.

  The conveyor belt longitudinal crack detection device disclosed in Japanese Patent Laid-Open No. 60-165540 (Patent Document 3) is a resonance circuit detection sensor embedded in the conveyor belt and installed outside the conveyor belt. In the device for detecting longitudinal tearing, belt position detecting means for detecting the distance traveled by the conveyor belt by the number of pulses is attached to the conveyor device. On the other hand, the number of pulse signals from the belt position detecting means and the sensor for detecting the resonance circuit are detected. A control device for storing the respective pulse signals is provided, and an abnormality of the conveyor belt is detected by comparing the number of stored pulse signals with the number of newly detected pulse signals.

  The conveyor belt longitudinal crack detection control method and control device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 61-018618 (Patent Document 4) are embedded so as to satisfy at least the belt width in the direction intersecting the longitudinal direction of the conveyor belt. A plurality of resonance circuits, and a plurality of resonance detectors provided at positions corresponding to the coil portions of the resonance circuit, and when the resonance detector detects a resonance phenomenon, a signal is output, A signal indicating that the conveyor belt is abnormal is output to the drive control device of the conveyor belt only when there is a longitudinal crack in the conveyor belt and a detection signal cannot be obtained by any one of the plurality of detectors. is there.

  In the conveyor belt longitudinal crack detection device disclosed in Japanese Patent Laid-Open No. 61-081315 (Patent Document 5), resonance circuits are embedded in the longitudinal direction of the conveyor belt at substantially equal intervals. In a longitudinal crack detection device in which two detectors installed at a predetermined distance from each other detect the passage of the resonance circuit to detect the longitudinal crack of the conveyor belt, in the vicinity of the outer peripheral portion of the driven wheel of the conveyor belt at equal intervals In addition to providing a pulse generating member, a pulse detection device is provided above the trajectory of the pulse generating member so that the belt travel distance can be detected by the number of pulses, and the control device of the longitudinal crack detection device passes the resonance circuit through the belt. A longitudinal crack of the conveyor belt is detected while contrasting with the distance.

  In the conveyor belt longitudinal crack detection device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. Sho 62-28581 (Patent Document 6), an object to be detected is buried in the conveyor belt, and a longitudinal crack is detected by a detector installed outside the conveyor belt. An apparatus for detecting, comprising: means for detecting the travel distance of the conveyor belt by the number of pulses; and storage means for storing the embedment position of the detected object according to the number of pulse signals from the detection means. A control device that, when a signal from the detector is obtained, collates with the stored contents of the storage means, and determines whether the signal is a normal signal based on the passage of the detected object; is there.

  The conveyor belt longitudinal tear detection device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 6-048549 (Patent Document 7) detects a normal state or a disconnection state of a detection object embedded in a plurality of locations of the conveyor belt by an externally installed sensor. Then, in a device for detecting the occurrence of longitudinal tearing of the belt by performing a predetermined process on the voltage signal generated from the sensor by the control device, the voltage signal generated from the sensor is converted to a frequency in the vicinity of the sensor. A V / F converter is arranged, and an F / V converter that converts the frequency into a voltage signal again is arranged in the control device, and these V / F converter and F / V converter are connected by a signal cable.

  The conveyor belt longitudinal crack detection device disclosed in the above-mentioned JP-A-8-324752 (Patent Document 8) includes a plurality of coils including conductive wires embedded in the conveyor belt and extending in the width direction of the conveyor belt. An object to be detected, a detection unit which is fixedly disposed at a predetermined position below the conveyor belt and outputs a predetermined detection signal, and whether or not the conductive wire of the detection object is cut based on the detection signal In the conveyor belt longitudinal crack detection device that detects longitudinal cracks of the conveyor belt, the determination unit is arranged at a predetermined distance from the conveyor belt.

The conveyor belt longitudinal crack detection device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 11-208862 (Patent Document 9) is a conveyor in which a plurality of detected objects having loop coils including conductive wires extending in the width direction of the belt are embedded. A conveyor belt longitudinal crack detection device comprising a belt and detecting a longitudinal crack of the conveyor belt by cutting a loop coil of the detected object, and a transmitting coil disposed at a predetermined distance that causes mutual induction And an antenna provided opposite to the belt surface of the conveyor belt, an oscillating means for oscillating the AC signal having a predetermined amplitude having a predetermined amplitude as a reference signal, and the transmitting coil Driving means for supplying a drive signal based on the reference signal, and information indicating that the detected object is within a predetermined distance from the antenna unit Based on the presence detection means to be obtained, the information that the detected object is present within a predetermined distance from the antenna unit, and the level of the AC signal induced in the sense coil, the detected object is at a predetermined distance from the antenna unit. And a disconnection detecting means for detecting that the loop coil of the detected object is disconnected when the level change of the AC signal induced in the sense coil when it is present within a predetermined value or less. .
JP 58-222001 Japanese Utility Model Publication No.59-108726 JP 60-165540 A JP-A-61-018618 JP 61-081315 A Japanese Patent Laid-Open No. 62-285813 JP-A-6-048549 JP-A-8-324752 Japanese Patent Laid-Open No. 11-208862

  In each of the conventional devices described above, a resonance circuit including a coil or the like is embedded in the conveyor belt, and a detection circuit fixed to the outside of the belt is provided with a resonance circuit including a detection coil. By detecting the change in inductance due to the resonance phenomenon caused by the coupling of the coil of the resonance circuit that becomes the detection body and the coil of the detection resonance circuit, the resonance circuit in the conveyor belt operates normally, and the belt splits vertically. It is determined that it is not. In addition, when a longitudinal tear occurs in the conveyor belt, the resonance circuit is disconnected and becomes inoperable, thereby detecting the longitudinal tear of the conveyor belt.

  However, if the conveyor is driven for a long time, the resonance circuit in the conveyor belt does not break or break, and the resistance value of the conductive wire increases due to fatigue damage, or the inductance value of the coil or capacitor When the capacitance value changes, the resonance frequency changes, the degree of the resonance phenomenon with the detection resonance circuit decreases, and the normal detection signal often fails to detect the operation of the resonance circuit of the detected object. . For this reason, it is erroneously detected that a vertical tear has occurred in the conveyor belt even though no vertical tear has occurred in the conveyor belt, and the drive of the conveyor belt is stopped. When the drive of the conveyor belt is stopped due to such erroneous detection, the work efficiency is significantly lowered.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to provide a longitudinal conveyor belt that can detect fatigue damage of the resonance circuit of the detected object at an early stage and reduce false detection of belt longitudinal tearing. It is in providing a crack detection apparatus.

In order to achieve the above object, the present invention provides a single resonance circuit comprising a coil including a conductive wire embedded in a conveyor belt at a predetermined interval in the longitudinal direction of the conveyor belt and extending in the width direction of the conveyor belt. A detection unit configured to be fixed at a predetermined position below the conveyor belt and resonate with a resonance circuit of the detection target to detect the resonance state; the detection unit; and the detection target. And a determination unit for determining whether or not the conductive wire of the detected object is cut based on a resonance state with the body, and in a conveyor belt longitudinal crack detecting device for detecting longitudinal tear of the conveyor belt, the progress of the conveyor belt with each being arranged at predetermined intervals in the direction and comprises a first detector and a second detector having an antenna coil, the detection sense of the resonance state by the first detection unit Wherein which the detection sensitivity of the resonant state is set to different values by the second detector and the decision unit, the supplies a predetermined first alternating current to the first detecting portion of the antenna coil the Current supply means for supplying a predetermined second alternating current to the antenna coil of the two detectors; current amount monitoring means for monitoring the amount of current supplied to the first detector and the second detector; and the first detector The current amount of the first alternating current supplied to the first reference value is compared with a first reference value, and when the current amount of the first alternating current does not satisfy the first reference value, the current passes through the vicinity of the first detection unit. A first determination means for determining that an abnormality has occurred in the detected object; and a current amount of the second alternating current supplied to the second detection unit is compared with a second reference value to determine the second alternating current When the amount of current is less than the second reference value, the vicinity of the second detection unit Of the first determination means and the second determination means, the second determination means determines that an abnormality has occurred in the detected object that has passed, and the determination results of the first determination means and the second determination means. When it is determined that an abnormality has occurred only by the determination means corresponding to the detection unit having a low detection sensitivity, it is determined that fatigue damage has occurred in the detection target object, and the first determination Of the conveyor belt when the abnormality is determined by the determination means corresponding to the detection unit having a high detection sensitivity among the first determination means and the second determination means. When the first and second determination means do not determine that an abnormality has occurred in the object to be detected, the conveyor belt has no vertical tearing and is not covered. If an abnormality occurs in the detection object And a comprehensive determination means for determining that there is not, and at least one of the set of the first alternating current and the second alternating current or the set of the first reference value and the second reference value has a different value. Is set.

  According to the conveyor belt longitudinal crack detection apparatus of the present invention, the first detection unit and the second detection unit are arranged in parallel at a predetermined interval in the traveling direction of the conveyor belt. The detection sensitivity of the state and the detection sensitivity of the resonance state by the second detection unit are set to different values.

Also, the current amount of the alternating current supplied to the detection unit by the determination unit without detecting the resonance with the detection target by the detection unit whose detection sensitivity of the first detection unit and the second detection unit is set low. Is in a state that does not satisfy the reference value, and the detection unit having a high detection sensitivity among the first detection unit and the second detection unit detects resonance with the detected object and is supplied to the detection unit When the current amount of the alternating current reaches the reference value, it is determined that fatigue damage has occurred in the detected object. Further, the determination unit sets at least one of the first detection unit and the second detection unit so that the detection unit set to a high detection sensitivity does not detect resonance, and the amount of alternating current supplied to the detection unit is set to the reference value. When the condition is not satisfied, it is determined that the conveyor belt has a longitudinal tear and the conductive wire of the object to be detected is cut, and both the first detection unit and the second detection unit detect the resonance, respectively. When the current amount of the alternating current supplied to the detection unit has reached the reference value, it is determined that no vertical tear has occurred in the conveyor belt and no abnormality has occurred in the detected object.

  According to the longitudinal crack detection device for a conveyor belt of the present invention, the resonance circuit in the conveyor belt does not reach disconnection or breakage, and it can be detected at an early stage that fatigue damage has occurred. As a result, when the resistance value of the conductive wire of the resonance circuit of the detection target increases, or when the inductance value of the coil or the capacitance value of the capacitor changes, the resonance frequency changes, and the degree of the resonance phenomenon with the detection resonance circuit Can be detected at an early stage, so even though the conveyor belt is not longitudinally split, it is erroneously detected as having occurred in the conveyor belt and the drive of the conveyor belt is stopped. Therefore, it is possible to prevent the conveyor belt from being stopped due to such a malfunction, so that the work efficiency can be improved.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a configuration diagram showing a conveyor device and a conveyor belt longitudinal crack detection device according to the first embodiment of the present invention, and FIG. 2 shows an electric circuit of the conveyor belt longitudinal crack detection device according to the first embodiment of the present invention. FIG. 3 is a block diagram and FIG. 3 is a diagram for explaining the arrangement of detection units in the first embodiment of the present invention.

  In the figure, reference numeral 10 denotes a conveyor device including a conveyor belt longitudinal crack detection device, which includes a drive pulley 12, a driven pulley 13, a conveyor belt 14 and a drive pulley 12 spanned between the drive pulley 12 and the driven pulley 13. An electric motor 15 to be rotated, an encoder 16, a hopper 17 for loading and dropping a transported object such as rock or iron ore onto the conveyor belt 14, detection units 18 </ b> A and 18 </ b> B, and a determination unit 19. In the present embodiment, the detection unit 18A, 18B and the determination unit 19 constitute the conveyor belt longitudinal crack detection device of the present invention.

  Further, similarly to the conventional example shown in FIG. 11, a plurality of detection objects are embedded in the conveyor belt 14 at predetermined equal intervals in the longitudinal direction. In addition, the resonance circuit 6 of two to-be-detected bodies is embedded adjacent to the reference position of the conveyor belt 14, so that the reference position can be easily detected.

  The object to be detected is composed of, for example, a resonance circuit 6 including a coil 6a and a capacitor 6b, and a part of the conductive wire forming the coil 6a extends in the width direction of the conveyor belt 14 and is embedded in the conveyor belt 14. . The resonance frequency of the resonance circuit 6 is set to about 650 KHz.

  The driven pulley 13 is provided with an encoder 16 from which N (N is a natural number) timing pulse signals TP are output at equal intervals during one rotation. The output timing of the timing pulse signal TP is set in synchronization with the movement of the resonance circuit 6 embedded in the conveyor belt 14. Since the conveyor belt 14 easily slips on the drive pulley 12 side, if the encoder 16 is provided on the drive pulley 12 side, the output timing of the timing pulse signal TP may not be synchronized. In this embodiment, the driven pulley An encoder 16 is provided on the 13th side.

  On the other hand, two detection units 18A and 18B are fixedly disposed below the conveyor belt 14 on which the object to be conveyed is placed, and these detection units 18A and 18B are arranged side by side in the longitudinal direction of the conveyor belt 14. Has been. Further, one detection unit 18A is disposed immediately before the hopper 17 provided on the starting end portion of the conveyor belt 14, that is, in front of the conveyor belt 14, and the other detection unit 18B is disposed immediately after the hopper 17. Yes. In general, since there is a higher probability that the vertical crack of the conveyor belt 14 will occur on the side of the conveyor belt 14 in the traveling direction than directly below the hopper 17, the detection units 18A and 18B are arranged as described above to be described later. As described above, the fatigue damage of the resonance circuit 6 can be easily detected, and the breakage of the resonance circuit 6, that is, the occurrence of the longitudinal tearing of the conveyor belt 14 can be detected at an early stage.

  Each of the detection units 18A and 18B has, for example, an insulator casing 111 having a width of 10 cm, a length of 25 cm, and a thickness of 3 cm, and the antenna coil 112 and the variable resistor 113 are accommodated in the casing 111. ing. The antenna coil 112 is formed in a shape substantially corresponding to the casing 111, that is, rectangular or elliptical, and the detection units 18A and 18B are arranged so that the antenna coil 112 extends in the width direction of the conveyor belt 14.

  The determination unit 19 includes an oscillation circuit 211, a first current value detection circuit 212, a second current value detection circuit 213, a first determination circuit 214, a second determination circuit 215, a comprehensive determination circuit 216, a display control circuit 217, and a display unit. 218, an alarm signal generation circuit 219, and a power supply circuit 220.

  The oscillation circuit 211 operates by the electric power supplied from the power supply circuit 220, and supplies an alternating current of about 650 KHz to the antenna coil 112 of each detection unit 18A, 18B. That is, one output terminal of the oscillation circuit 211 is connected to one end of the antenna coil 112 of each detection unit 18A, 18B. The other output terminal of the oscillation circuit 211 is connected to the other end of the antenna coil 112 of the detection unit 18A via the first current value detection circuit 212 and the variable resistor 113, and the second current value detection circuit 213. The other end of the antenna coil 112 of the detection unit 18B is connected via the variable resistor 113.

  The first current value detection circuit 212 converts the alternating current supplied from the oscillation circuit 211 to the antenna coil 112 of the one detection unit 18A into a voltage, and then converts the current into a direct current voltage by full-wave rectification and smoothing. Is output to the first determination circuit 214.

  The second current value detection circuit 213 converts the alternating current supplied from the oscillation circuit 211 to the antenna coil 112 of the other detection unit 18B into a voltage, and then converts the direct current into a direct current voltage by full-wave rectification and smoothing. The voltage is output to the second determination circuit 215.

  The first determination circuit 214 receives the DC voltage output from the first current value detection circuit 212 and the timing pulse signal TP output from the encoder 16, and the resonance circuit 6 of the detected object passes over the detection unit 18A. It is determined whether or not the DC voltage value at this time is equal to or less than a predetermined first reference value TH1, and if it is not less than or equal to the first reference value TH1, an abnormality occurs in the resonance circuit 6 of the detected object. A signal indicating an abnormal state is output to the overall determination circuit 216.

  The second determination circuit 215 receives the DC voltage output from the second current value detection circuit 213 and the timing pulse signal TP output from the encoder 16, and the resonance circuit 6 of the detected object passes over the detection unit 18B. It is determined whether or not the DC voltage value at this time is equal to or less than a predetermined second reference value TH2. If the DC voltage value is not equal to or less than the second reference value TH2, an abnormality occurs in the resonance circuit 6 of the detected object. A signal indicating an abnormal state is output to the overall determination circuit 216.

  The first reference value TH1 and the second reference value TH2 are set to the same value.

  The overall determination circuit 216 receives the output signal of the first determination circuit 214 and the output signal of the second determination circuit 215, determines the state of the resonance circuit 6 of the detected object based on these, and based on the determination result Thus, a signal for driving the display control circuit 217 and the alarm signal generation circuit 219 is output. That is, the overall determination circuit 216 determines that there is no abnormality in the resonance circuit of the detected object when both the output signal of the first determination circuit 214 and the output signal of the second determination circuit 215 do not indicate an abnormal state. The display control circuit 217 outputs a signal for performing display without abnormality, and the alarm signal generation circuit 219 does not output a drive signal. The overall determination circuit 216 causes fatigue damage to the resonance circuit 6 of the detected object when the output signal of the first determination circuit 214 indicates an abnormal state and the output signal of the second determination circuit 215 does not indicate the abnormal state. Therefore, the display control circuit 216 outputs a signal for displaying fatigue damage, and does not output a drive signal to the alarm signal generation circuit 219. Furthermore, the overall determination circuit 216 determines whether the detected signal is detected when both the output signal of the first determination circuit 214 and the output signal of the second determination circuit 215 or at least the output signal of the second determination circuit 215 indicates an abnormal state. It is determined that the resonance circuit 6 has been broken, that is, a vertical tear has occurred in the conveyor belt 14 and the conductive wire of the resonance circuit 6 has been cut, and a signal for causing the display control circuit 217 to display the occurrence of the vertical crack is provided. At the same time, it outputs a drive signal to the alarm signal generation circuit 219.

  Further, the comprehensive determination circuit 216 receives the timing pulse signal TP output from the encoder 16, and calculates the distance from the reference position by counting the number of timing pulse signals TP. The distance from the reference position is calculated based on the value of the diameter of the drive pulley 12 set in advance in the comprehensive determination circuit 216. When the comprehensive judgment circuit 216 displays the fatigue damage or the occurrence of longitudinal cracks on the display unit 218 as a notification means via the display control circuit 217, the distance from the calculated reference position, that is, fatigue damage occurs. The position of the resonant circuit 6 that is broken or broken is displayed.

  The display control circuit 217 performs display on the display unit 218 based on the signal input from the comprehensive determination circuit 216.

  The alarm signal generation circuit 219 outputs an abnormal signal to the electric motor 15 when the driving signal is input from the comprehensive determination circuit 216, and stops the electric motor 15.

  The power supply circuit 220 receives power from a commercial power supply, converts it into a DC voltage, and supplies driving power to each circuit in the apparatus.

  In the present embodiment, the level of the alternating current supplied to the antenna coil 112 of the one detection unit 18A is larger than the level of the alternating current supplied to the antenna coil 112 of the other detection unit 18B. The resistance value of the variable resistor 113 of each detection unit 18A, 18B is set. Thus, in this embodiment, the detection sensitivity of one detection unit 18A is set lower than the detection sensitivity of the other detection unit 18B.

  In the present embodiment, the first detection unit 18A, the first current value detection circuit 212, and the first determination circuit 214 constitute a first detection unit in the present invention, and the second detection unit 18B and the second current value detection circuit. 213 and the second determination circuit 215 form a second detection unit in the present invention, and the comprehensive determination circuit 216 forms a determination unit in the present invention.

  In the conveyor belt longitudinal crack detection device having the above-described configuration, when there is no longitudinal tear in the conveyor belt 14, each resonance circuit 6 operates normally, and the resonance circuit 6 is positioned on the detection units 18A and 18B. Sometimes, the antenna coil 112 and the resonance circuit 6 are electromagnetically coupled. As a result, the energy radiated from the antenna coil 112 is absorbed by the resonance circuit 6, so that the level of the alternating current supplied to the antenna coil 112 is reduced, so that the direct current voltage output from the first current value detection circuit 212 is reduced. Since the value of 1 is equal to or less than the first reference value and resonance can be detected, and the value of the DC voltage output from the second current value detection circuit 213 is equal to or less than the second reference value and resonance can be detected, it is confirmed that the resonance circuit 6 is normal. Is done.

  In addition, when a vertical tear occurs in the conveyor belt 14 in use due to protrusions of fallen objects from the hopper 17, the conductive wire constituting the coil 6a of the resonance circuit 6 embedded in the conveyor belt 14 is cut. Since the resonance circuit 6 does not operate, energy radiated from the antenna coil 112 is not absorbed by the resonance circuit 6. For this reason, since the level of the alternating current supplied to the antenna coil 112 does not decrease, the value of the direct current voltage output from the first current value detection circuit 212 does not fall below the first reference value, so that resonance cannot be detected. Since the value of the DC voltage output from the two-current value detection circuit 213 is not less than or equal to the second reference value, resonance cannot be detected, so that a signal indicating abnormality is output from both the first determination circuit 214 and the second determination circuit 215. The As a result, the overall determination circuit 216 determines that a vertical tear has occurred in the conveyor belt 14 and the conductive wire of the resonance circuit 6 has been disconnected, and displays that the vertical tear has occurred in the conveyor belt 14 via the display control circuit 217. The alarm signal generation circuit 219 outputs an abnormal signal to the electric motor 15 and stops the electric motor 15.

  Further, when the resonance circuit 6 of the detected object does not reach the disconnection or breakage and fatigue damage has occurred, the resistance value of the conductive wire of the resonance circuit 6 increases, the inductance value of the coil, the capacitor Since the capacitance value changes, the resonance frequency changes and the degree of the resonance phenomenon with the antenna coil 112 decreases, so that the level of the alternating current supplied to the antenna coil 112 of the detection units 18A and 18B decreases. The value of the DC voltage output from the first current value detection circuit 212 is reduced and the value of the DC voltage output from the second current value detection circuit 213 cannot be detected because the value of the DC voltage output from the first current value detection circuit 212 is not less than the first reference value. Is equal to or lower than the second reference value and resonance can be detected, and therefore, a signal indicating an abnormality is output from only the first determination circuit 214. As a result, the overall determination circuit 216 determines that fatigue damage has occurred in the resonance circuit 6 of the detection target, and displays on the display unit 218 that the fatigue damage has occurred in the resonance circuit 6 via the display control circuit 217. .

  Further, since the position of the resonance circuit 6 in which fatigue damage or destruction has occurred is displayed on the display unit 218 at a distance from the reference position, the efficiency of maintenance work can be improved.

  Furthermore, although the conveyor belt 14 may be displaced in the width direction during conveyance, as described above, since the detection units 18A and 18B are arranged extending in the width direction of the conveyor belt 14, the state of the resonance circuit 6 is changed. It can be detected reliably.

  As described above, according to the conveyor belt longitudinal crack detection device of this embodiment, the resonance circuit 6 in the conveyor belt 14 does not reach disconnection or breakage, and it is discovered early that fatigue damage has occurred. Can do. As a result, when the resistance value of the conductive wire of the resonance circuit 6 of the object to be detected is increased, or when the inductance value of the coil or the capacitance value of the capacitor is changed, the resonance frequency is changed. Since it can be detected at an early stage that the degree is reduced, it is erroneously detected that a vertical tear has occurred in the conveyor belt 14 even though the conveyor belt 14 has not been longitudinally split, and the drive of the conveyor belt 14 is detected. Can be prevented from being stopped, and the driving stop of the conveyor belt 14 due to such a malfunction can be prevented, so that the work efficiency can be improved.

  In the present embodiment, the level of the alternating current supplied to the antenna coil 112 of the detection units 18A and 18B is set to a different value by the variable resistor 113, so that the detection sensitivities of the detection units 18A and 18B are different. However, by setting the level of the alternating current supplied to the antenna coil 112 of the detection units 18A and 18B to be the same, and setting the first reference value TH1 and the second reference value TH2 to different values, You may make it vary the detection sensitivity by each detection unit 18A, 18B.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.

  FIG. 4 is a block diagram showing an electric system circuit of the conveyor belt longitudinal crack detection device according to the second embodiment of the present invention. In the figure, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. The difference between the second embodiment and the first embodiment is that A / D (analog / digital) is used instead of the first determination circuit 214, the second determination circuit 215, and the overall determination circuit 216 in the first embodiment. The determination unit 19A provided with the conversion circuits 221, 222, the CPU 223, and the memory 224 is provided, and the determination processing is performed by the program processing of the CPU 223. Other configurations are the same as those of the first embodiment described above.

  In the second embodiment shown in FIG. 4, the DC voltage output from the first current value detection circuit 212 is input to the A / D conversion circuit 221, and the voltage value is converted into digital data by the A / D conversion circuit 221. To the CPU 223. Further, the DC voltage output from the second current value detection circuit 213 is input to the A / D conversion circuit 222, and the voltage value is converted into digital data by the A / D conversion circuit 222 and output to the CPU 223.

  The CPU 223 operates according to a program stored in the memory 224, and the determination processing performed by the first determination circuit 214, the second determination circuit 215, and the overall determination circuit 216 in the first embodiment, and display based on the determination result Drive control of the control circuit 217 and the alarm signal generation circuit 219 is performed.

  That is, as shown in the flowchart of FIG. 5, the CPU 223 grasps the position of the resonance circuit 6 of the detected object by counting the timing pulse signal TP, and whether or not the resonance circuit 6 is positioned on the detection unit 18A. (S1), and the voltage value V1 output from the A / D conversion circuit 221 when the resonance circuit 6 is positioned on the detection unit 18A is captured (S2). Further, it is determined whether or not the resonance circuit 6 moves from the detection unit 18A to the detection unit 18B and is positioned on the detection unit 18B (S3), and the resonance circuit 6 is positioned on the detection unit 18B. The voltage value V2 output from the A / D conversion circuit 222 is taken in (S4).

  Next, it is determined whether or not the voltage value V1 is larger than the first reference value TH1 (S5). When the voltage value V1 is equal to or less than the first reference value TH1, it is determined that there is no abnormality in the resonance circuit 6. The process proceeds to S1. When the voltage value V1 is larger than the first reference value TH1, it is determined whether or not the voltage value V2 is larger than the second reference value TH2 (S6).

  As a result of this determination, if the voltage value V2 is larger than the second reference value TH2, it is assumed that the conveyor belt 14 has been longitudinally split and the conductive wire of the resonance circuit 6 has been cut off, and the conveyor via the display control circuit 217. The fact that the belt 14 has been split is displayed on the display unit 218 (S7), the warning signal generation circuit 219 is instructed to output an abnormal signal, and the motor 15 is caused to output an abnormal signal, The electric motor 15 is stopped (S8).

  When the voltage value V2 is equal to or lower than the second reference value TH2, it is determined that fatigue damage has occurred in the resonance circuit 6 of the detection target, and fatigue damage has occurred in the resonance circuit 6 via the display control circuit 217. This is displayed on the display unit 218 (S9).

  In parallel with the above processing, the CPU 223 inputs the timing pulse signal TP output from the encoder 16, and calculates the distance from the reference position by counting the number of timing pulse signals TP. The distance from the reference position is calculated based on the value of the diameter of the drive pulley 12 preset in the memory 224. When the CPU 223 displays the fatigue damage or the vertical crack occurrence on the display unit 218 via the display control circuit 217, the calculated distance from the reference position, that is, the fatigue damage has occurred or has been destroyed. The position of the resonance circuit 6 is displayed.

  In the present embodiment, the first detection unit 18A, the first current value detection circuit 212, the A / D conversion circuit 221 and the CPU 223 constitute the first detection unit in the present invention, and the second detection unit 18B and the second current value detection. The circuit 213, the A / D conversion circuit 222, and the CPU 223 constitute a second detection unit in the present invention, and the CPU 223 constitutes a determination unit in the present invention.

  Even if the determination process is performed by the computer program using the CPU 223 as in the present embodiment, the resonance circuit 6 in the conveyor belt 14 does not reach disconnection or breakage, and fatigue damage occurs as in the first embodiment. Can be found early.

  Further, since the position of the resonance circuit 6 in which fatigue damage or destruction has occurred is displayed on the display unit 218 at a distance from the reference position, the efficiency of maintenance work can be improved.

  Therefore, also in the second embodiment, when the resistance value of the conductive wire of the resonance circuit 6 of the detection target increases, or when the inductance value of the coil or the capacitance value of the capacitor changes, the resonance frequency changes. It is possible to detect early that the degree of the resonance phenomenon during the period is reduced, so that although the conveyor belt 14 is not longitudinally split, it is erroneously detected that the conveyor belt 14 has been longitudinally split, The malfunction that the driving of the conveyor belt 14 is stopped can be prevented, and the driving stop of the conveyor belt 14 due to such a malfunction can be prevented, so that the working efficiency can be improved.

  In the present embodiment, the level of the alternating current supplied to the antenna coil 112 of the detection units 18A and 18B is set to a different value by the variable resistor 113, so that the detection sensitivities of the detection units 18A and 18B are different. However, the level of the alternating current supplied to the antenna coil 112 of the detection units 18A and 18B is set to be the same, and the first reference value TH1 and the second reference value TH2 of the program of the CPU 223 are set to different values. Thus, the detection sensitivities of the detection units 18A and 18B may be made different. Further, the first reference value TH1 and the second reference value TH2 may be appropriately set from the outside using a switch, a variable resistor, or the like.

(Third embodiment)
Next, a third embodiment of the present invention will be described.

  FIG. 6 is a block diagram showing a conveyor device and a conveyor belt longitudinal crack detection device in the third embodiment of the present invention, FIG. 7 is a diagram for explaining the arrangement of detection units in the third embodiment of the present invention, and FIG. FIG. 9 is a block diagram showing an electric system circuit of a conveyor belt longitudinal crack detection apparatus according to a third embodiment of the present invention, and FIG. 9 is a block diagram showing an electric system circuit of a detection unit in the third embodiment of the invention. In the figure, the same components as those in the first and second embodiments described above are denoted by the same reference numerals and description thereof is omitted.

  The difference between the present embodiment and the first and second embodiments is that the detection units 31A, 31B and the determination unit are replaced with the detection units 18A and 18B and the determination units 19 and 19A in the first and second embodiments. 50, and the determination unit 50 is arranged away from the conveyor device 10 by a predetermined distance.

  That is, the detection units 31 </ b> A and 31 </ b> B are fixedly arranged at the lower part of the conveyor belt 14 on which the object to be conveyed is placed, and these detection units 31 </ b> A and 31 </ b> B are arranged in parallel in the longitudinal direction of the conveyor belt 14. Further, one detection unit 31A is arranged immediately before the hopper 17 provided on the starting end of the conveyor belt 14, that is, in front of the conveyor belt 14, and the other detection unit 31B is arranged immediately after the hopper 17. Yes.

  Each of the detection units 31A and 31B has an insulating casing 311 having a width of 10 cm, a length of 25 cm, and a thickness of 3 cm, as shown in FIG. 7, for example. Circuit 313 is housed. The antenna coil 312 is formed in a shape substantially corresponding to the housing 311, that is, in a rectangular or elliptical shape, and the detection units 31 </ b> A and 31 </ b> B are arranged so that the antenna coil 312 extends in the width direction of the conveyor belt 14.

  As shown in FIG. 8, the detection circuit 313 includes an oscillation circuit 313a, a filter circuit 313b, and a frequency conversion circuit 313c.

  The oscillation circuit 313a operates with the electric power PW supplied from the determination unit 50, and supplies an alternating current HS of about 650 KHz to the antenna coil 312. Further, the current value of the alternating current HS can be changed by changing the value of the variable resistor VR provided in the oscillation circuit 313a.

  The filter circuit 313b receives an alternating current supplied to the antenna coil 312 and outputs only a component having a frequency of 650 KHz in the alternating current to the frequency conversion circuit 313c.

  The frequency conversion circuit 313c converts the signal having a frequency of 650 KHz input from the filter circuit 313b into a low-frequency signal that is not affected by the broadcast radio wave, for example, an AC voltage signal LS having a frequency of 20 to 50 KHz, and outputs the signal to the determination unit 50. . The driving power PW is also supplied from the determination unit 50 to the filter circuit 313b and the frequency conversion circuit 313c.

  As shown in FIG. 9, the determination unit 50 includes a power supply circuit 501, a first level determination circuit 502, a second level determination circuit 503, a comprehensive determination circuit 504, a display control circuit 505, a display unit 506, an alarm signal generation circuit. 507 and a power supply circuit 508.

  The power supply circuit 501 supplies drive power PW to each of the detection units 31A and 31B.

  The first level determination circuit 502 receives the AC voltage signal LS output from the one detection unit 31A and the timing pulse signal TP output from the encoder 16, and the resonance circuit 6 of the detected object passes over the detection unit 31A. It is determined whether or not the value of the AC voltage signal LS when passing is equal to or less than a predetermined first reference value THa. When the value is not less than or equal to the first reference value THa, the resonance circuit 6 of the detected object is detected. It is determined that an abnormality has occurred, and a signal indicating an abnormal state is output to the overall determination circuit 504.

  The second level determination circuit 503 receives the AC voltage signal LS output from the other detection unit 31B and the timing pulse signal TP output from the encoder 16, and the resonance circuit 6 of the detected object passes over the detection unit 31B. It is determined whether or not the value of the AC voltage signal LS when passing is equal to or less than a predetermined second reference value THb. When the value is not equal to or less than the second reference value THb, the resonance circuit 6 of the detected object is detected. It is determined that an abnormality has occurred, and a signal indicating an abnormal state is output to the overall determination circuit 504.

  The overall determination circuit 504 inputs the output signal of the first level determination circuit 502 and the output signal of the second level determination circuit 503, and based on these, determines the state of the resonance circuit 6 of the detected object, and this determination Based on the result, a signal for driving the display control circuit 505 and the alarm signal generation circuit 507 is output. That is, the overall determination circuit 504 indicates that there is no abnormality in the resonance circuit 6 of the detected object when both the output signal of the first level determination circuit 502 and the output signal of the second level determination circuit 503 do not indicate an abnormal state. The display control circuit 505 outputs a signal that causes display without abnormality, and the alarm signal generation circuit 507 does not output a drive signal.

  The overall determination circuit 504 also causes the resonance circuit 6 of the detected object to become fatigued when the output signal of the first level determination circuit 502 indicates an abnormal state and the output signal of the second level determination circuit 503 does not indicate an abnormal state. The display control circuit 505 outputs a signal for displaying fatigue damage, and does not output a drive signal to the alarm signal generation circuit 507.

  Furthermore, the overall determination circuit 504 is configured such that both the output signal of the first level determination circuit 502 and the output signal of the second level determination circuit 503 or at least the output signal of the second level determination circuit 503 indicate an abnormal state. It is determined that a longitudinal tear occurs in the conveyor belt, the conductive wire of the resonance circuit 6 of the detected object is cut, and the resonance circuit 6 is broken, and a signal for causing the display control circuit 505 to display the occurrence of the vertical tear is provided. At the same time, it outputs a drive signal to the alarm signal generation circuit 507.

  Furthermore, the comprehensive determination circuit 504 receives the timing pulse signal TP output from the encoder 16 and calculates the distance from the reference position by counting the number of the pulse signals TP. The distance from the reference position is calculated based on the value of the diameter of the drive pulley 12 set in advance in the comprehensive determination circuit 504. When the comprehensive judgment circuit 504 displays the fatigue damage or the occurrence of vertical tearing on the display unit 506 via the display control circuit 505, the distance from the calculated reference position, that is, the fatigue damage has occurred or is broken. The position of the resonant circuit 6 being displayed is displayed.

  The display control circuit 505 performs display on the display unit 506 based on the signal input from the comprehensive determination circuit 504.

  The alarm signal generation circuit 507 outputs an abnormal signal to the electric motor 15 when the driving signal is input from the general determination circuit 504, and stops the electric motor 15.

  The power supply circuit 508 receives electric power from a commercial power supply, converts it into a DC voltage, and supplies driving power to each circuit in the apparatus.

  In this embodiment, the level of the alternating current supplied to the antenna coil 312 of one detection unit 31A is larger than the level of the alternating current supplied to the antenna coil 312 of the other detection unit 31B. The resistance value of the variable resistor VR of each detection unit 31A, 31B is set.

  In the present embodiment, the first detection unit 31A and the first level determination circuit 502 constitute a first detection unit in the present invention, and the second detection unit 31B and the second level determination circuit 503 in the second detection in the present invention. The overall determination circuit 504 forms a determination unit in the present invention.

  In the conveyor belt longitudinal crack detection device having the above-described configuration, when there is no longitudinal tear in the conveyor belt 14, each resonance circuit 6 operates normally, and the resonance circuit 6 is positioned on the detection units 31A and 31B. Sometimes, the antenna coil 312 and the resonance circuit 6 are electromagnetically coupled. Thereby, since the energy radiated from the antenna coil 312 is absorbed by the resonance circuit 6, the level of the alternating current supplied to the antenna coil 312 is lowered, so that the alternating current output from the frequency conversion circuit 313c of the detection unit 31A. Since the voltage value of the voltage signal LS becomes equal to or less than the first reference value THa and the voltage value of the AC voltage signal LS output from the frequency conversion circuit 313c of the detection unit 31B becomes equal to or less than the second reference value THb, the resonance circuit 6 Is confirmed to be normal.

  In addition, when a vertical tear occurs in the conveyor belt 14 in use due to protrusions of fallen objects from the hopper 17, the conductive wire constituting the coil 6a of the resonance circuit 6 embedded in the conveyor belt 14 is cut. Since the resonance circuit 6 does not operate, energy radiated from the antenna coil 312 is not absorbed by the resonance circuit 6. For this reason, since the level of the alternating current HS supplied to the antenna coil 312 does not decrease, the voltage value of the alternating voltage signal LS output from the frequency conversion circuit 313c of the detection unit 31A does not fall below the first reference value THa. Cannot be detected, and since the voltage value of the AC voltage signal LS output from the frequency conversion circuit 313c of the detection unit 31B is not less than or equal to the second reference value THb, resonance cannot be detected, so the first level determination circuit 502 and the second level A signal indicating abnormality is output from both of the determination circuits 503. As a result, the overall determination circuit 504 determines that a vertical tear has occurred in the conveyor belt and the conductive wire of the resonance circuit 6 has been disconnected, and that the vertical tear has occurred in the conveyor belt 14 via the display control circuit 505. In addition, the alarm signal generation circuit 507 outputs an abnormal signal to the electric motor 15 and stops the electric motor 15.

  Further, when the resonance circuit 6 of the detected object does not reach the disconnection or breakage and fatigue damage has occurred, the resistance value of the conductive wire of the resonance circuit 6 increases, the inductance value of the coil, the capacitor Since the capacitance value changes, the resonance frequency changes, and the degree of the resonance phenomenon between the antenna coil 312 and the level of the alternating current HS supplied to the antenna coil 312 of the detection units 31A and 31B decreases. Since the voltage value of the AC voltage signal LS output from the frequency conversion circuit 313c of the detection unit 31A does not become the first reference value THa or less, resonance cannot be detected and the frequency conversion circuit 313c of the detection unit 31B Since the voltage value of the output AC voltage signal LS is equal to or lower than the second reference value THb and resonance can be detected, a signal indicating an abnormality is received from only the first level determination circuit 502. Is output.

  As a result, the overall determination circuit 504 determines that fatigue damage has occurred in the resonance circuit 6 of the detection target, and displays on the display unit 506 that the fatigue damage has occurred in the resonance circuit 6 via the display control circuit 505. To do.

  Further, since the position of the resonance circuit 6 where fatigue damage or destruction has occurred is displayed on the display unit 506 at a distance from the reference position, the efficiency of maintenance work can be improved.

  Further, the conveyor belt 14 may be displaced in the width direction during conveyance. However, since the detection units 31A and 31B are arranged as described above, the state of the resonance circuit 6 can be reliably detected.

  As described above, according to the conveyor belt longitudinal crack detection device of this embodiment, the resonance circuit 6 in the conveyor belt 14 does not reach disconnection or breakage, and it is discovered early that fatigue damage has occurred. Can do. As a result, when the resistance value of the conductive wire of the resonance circuit 6 of the object to be detected is increased, or when the inductance value of the coil or the capacitance value of the capacitor is changed, the resonance frequency is changed. Since it can be detected at an early stage that the degree of deterioration has occurred, it is erroneously detected that the conveyor belt has undergone longitudinal tearing even though the conveyor belt has not undergone longitudinal tearing, and the drive of the conveyor belt is stopped. Malfunction can be prevented, and the driving stop of the conveyor belt due to such malfunction can be prevented, so that work efficiency can be improved.

  Further, in the present embodiment, the determination unit 50 is separated from the detection units 31A and 31B and is disposed away from the conveyor device 10, so that noise generated from the motor 15 is mixed in each circuit in the determination unit 50. There is nothing. Thereby, the malfunctioning by the noise in the determination unit 50 can be prevented.

  In the detection units 31A and 31B, only the 650 KHz signal supplied from the oscillation circuit 313a to the antenna coil 312 is input to the frequency conversion circuit 313c via the filter circuit 313b. Is not mixed in the frequency conversion circuit 313c.

  Furthermore, since the AC voltage signal LS output from the detection units 31A and 31B to the determination unit 50 has a low frequency of 20 to 50 KHz, broadcast radio waves and the like are not mixed, and malfunctions due to this can be prevented.

  In the present embodiment, the level of the alternating current HS supplied to the antenna coil 312 of the detection units 31A and 31B is set to a different value by the variable resistor VR, so that the detection sensitivity of each detection unit 31A and 31B is set. Although different, the level of the alternating current supplied to the antenna coil 312 of the detection units 38A and 31B is set to be the same, and the first reference value THa and the second reference value THb are set to different values. The detection sensitivities of the detection units 31A and 31B may be different.

  In addition, each of the above embodiments is a specific example of the present invention, and the present invention is not limited only to the configuration of the above embodiment, and each of the conventional examples disclosed in Patent Documents 1 to 9 described above. It goes without saying that the same effect as in the above embodiment can be obtained by applying the present invention to the above.

The block diagram which shows the vertical crack detection apparatus of the conveyor apparatus and conveyor belt in 1st Embodiment of this invention. The block diagram which shows the electric system circuit of the vertical crack detection apparatus of the conveyor belt in 1st Embodiment of this invention. The figure explaining arrangement | positioning of the detection unit in 1st Embodiment of this invention. The block diagram which shows the electric system circuit of the vertical crack detection apparatus of the conveyor belt in 2nd Embodiment of this invention. The flowchart explaining operation | movement of the vertical crack detection apparatus of the conveyor belt in 2nd Embodiment of this invention. The block diagram which shows the vertical crack detection apparatus of the conveyor apparatus and conveyor belt in 3rd Embodiment of this invention. The figure explaining arrangement | positioning of the detection unit in 3rd Embodiment of this invention. The block diagram which shows the electric system circuit of the detection unit in 3rd Embodiment of this invention. The block diagram which shows the electric system circuit of the vertical crack detection apparatus of the conveyor belt in 3rd Embodiment of this invention. Configuration diagram showing an internal vertical crack detection device of a conventional example The figure which shows the structure and arrangement | positioning of the resonance circuit of the to-be-detected body in a prior art example. The figure which shows arrangement | positioning of the detection part in a prior art example The block diagram which shows the electric system circuit of the detection part in a prior art example

Explanation of symbols

  DESCRIPTION OF SYMBOLS 6 ... Resonant circuit, 6a ... Coil, 6b ... Capacitor, 10 ... Conveyor device, 12 ... Drive pulley, 13 ... Drive pulley, 14 ... Conveyor belt, 15 ... Electric motor, 16 ... Encoder, 17 ... Hopper, 18A, 18B ... Detection Unit, 19, 19A ... determination unit, 31A, 31B ... detection unit, 50 ... determination unit, 111 ... housing, 112 ... antenna coil, 113 ... variable resistor, 211 ... oscillation circuit, 212 ... first current value detection circuit 213, second current value detection circuit, 214, first determination circuit, 215, second determination circuit, 216, comprehensive determination circuit, 217, display control circuit, 218, display unit, 219, alarm signal generation circuit, 220,. Power circuit, 221, 222 ... A / D conversion circuit, 223 ... CPU, 224 ... memory, 311 ... housing, 312 ... antenna coil, 313 ... detection circuit, 313a ... oscillation circuit, 313b ... filter circuit, 313c ... frequency conversion circuit, VR: Variable resistor, 5 01 ... Power supply circuit, 502 ... First level determination circuit, 503 ... Second level determination circuit, 504 ... Overall determination circuit, 505 ... Display control circuit, 506 ... Display unit, 507 ... Alarm signal generation circuit, 508 ... Power supply circuit .

Claims (6)

Is embedded in the conveyor belt at predetermined intervals in the longitudinal direction of the conveyor belt, a plurality of the detected body consisting of one resonant circuit having a coil including a conductive wire extending in the width direction of the conveyor belt, said conveyor A detection unit that is fixedly disposed at a predetermined position below the belt and resonates with a resonance circuit of the detection target, and detects the resonance state; and the detection target based on a resonance state of the detection unit and the detection target A determination unit for determining the presence or absence of cutting of the conductive wire of the body, and in a vertical crack detection device for a conveyor belt for detecting the vertical tear of the conveyor belt,
A first detection unit and a second detection unit, which are arranged in parallel at a predetermined interval toward the traveling direction of the conveyor belt and each have an antenna coil ;
The detection sensitivity of the resonance state by the first detection unit and the detection sensitivity of the resonance state by the second detection unit are set to different values,
The determination unit
Current supply means for supplying a predetermined first alternating current to the antenna coil of the first detector and supplying a predetermined second alternating current to the antenna coil of the second detector;
Current amount monitoring means for monitoring the amount of current supplied to the first detection unit and the second detection unit;
When the amount of the first alternating current supplied to the first detector is compared with a first reference value and the amount of the first alternating current is less than the first reference value, the first detector First determination means for determining that an abnormality has occurred in the detected object that has passed in the vicinity of
When the current amount of the second alternating current supplied to the second detection unit is compared with a second reference value and the current amount of the second alternating current is less than the second reference value, the second detection unit Second determination means for determining that an abnormality has occurred in the detected object that has passed in the vicinity of
Based on the determination results of the first determination unit and the second determination unit, the abnormality is detected only by the determination unit corresponding to the detection unit of which the detection sensitivity is set low among the first determination unit and the second determination unit. When it is determined that the detection target has occurred, it is determined that fatigue damage has occurred in the object to be determined, and the detection unit in which the detection sensitivity is set high among the first determination unit and the second determination unit When it is determined that an abnormality has occurred by the determination means corresponding to the above, it is determined that a longitudinal tear has occurred in the conveyor belt and the conductive wire of the detected object is cut, and the first determination means and the second determination means Comprehensive determination means for determining that both the determination means do not determine that an abnormality has occurred in the detected object and that the conveyor belt has not undergone longitudinal tearing and that no abnormality has occurred in the detection object;
A conveyor belt , wherein at least one of the set of the first alternating current and the second alternating current or the set of the first reference value and the second reference value is set to a different value. Longitudinal crack detection device. The conveyer belt longitudinal crack detection device according to claim 1, further comprising a notification unit configured to notify a determination result by the determination unit. The conveyor belt longitudinal crack detection device according to claim 1 , further comprising a notification unit configured to notify a determination result of the comprehensive determination unit. The vertical crack detection device for a conveyor belt according to claim 1 , wherein the antenna coils of the first detection unit and the second detection unit are formed to extend in the width direction of the conveyor belt. Means for detecting a reference position of the conveyor belt;
Means for detecting a relative position of the detected object passing over the first detection unit and the second detection unit with respect to the reference position;
Vertical裂検detection device of the conveyor belt according to any one of claims 1 to 4, characterized in that a means for displaying the relative position of the detected body and the vertical crack initiation point was the fatigue damage. The first detection unit and the second detection unit are provided with a fall position of a transported object mounted on the conveyor belt interposed therebetween, and the detection sensitivity is set low on the front side in the traveling direction of the conveyor belt. The detection part is arrange | positioned. The longitudinal crack detection apparatus of the conveyor belt in any one of Claim 1 thru | or 5 characterized by the above-mentioned.

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