Longitudinal tear detection device and method for conveyor belt

Abstract

Provided are a highly versatile and low-cost detection device and method capable of accurately detecting whether a longitudinal tear of a conveyor belt has occurred. The buried body 2 has, at one end of the coaxial cable 6, a connection to one side antenna portion 4 and a passive IC tag 3 connected thereto, and at the other end, the other side antenna portion 5. The buried body 2 is buried in the conveyor belt 17 such that the one side antenna portion 4, the IC tag 3, and the other side antenna portion 5 are spaced apart in the width direction, causing the coaxial cable 6 to be buried and extended in the width direction. And the calculation unit 12 determines whether the detector 10 has received the radio wave R2 transmitted from the IC tag 3 through the coaxial cable 6 and the other side antenna portion 5 in response to the radio wave R1 transmitted from the detector 10 to the other side antenna portion 5, and based on this determination result, detects whether a longitudinal tear of the conveyor belt 17 has occurred within the range where the coaxial cable 6 is buried.

Description

Technical Field

[0001] The present invention relates to a longitudinal tear detection device and method for a conveyor belt, and more particularly, to a detection device and method that are highly versatile and low in cost and can accurately detect whether a longitudinal tear of the conveyor belt has occurred. Background Art

[0002] A conveyor belt that runs around a conveying device conveys various conveyed objects to a conveying destination. Since various conveyed objects are put on the conveyor belt, cracks extending in the length direction of the conveyor belt (so-called longitudinal tears) may occur due to these conveyed objects. Various devices have been proposed to detect such longitudinal tears in the conveyor belt.

[0003] Conventionally, in order to detect a longitudinal tear occurring on a conveyor belt, for example, a toroidal coil buried in the conveyor belt and a detection device provided near the conveyor belt are used (see Patent Document 1). The transmitting part of the detection device emits high frequency to form a high-frequency magnetic field, and in this magnetic field, an induced current flows in the toroidal coil. Due to this induced current, an induced electromotive force is generated in the receiving part of the detection device. Therefore, based on whether an induced electromotive force is generated in the receiving part, it can be determined whether the toroidal coil passing through the installation position of the detection device is damaged, and when the toroidal coil is damaged, it can be determined that a longitudinal tear has occurred.

[0004] The toroidal coil is a special product (a dedicated component) rather than a general-purpose component, so it is expensive. The detection device that emits high frequency and detects the induced electromotive force is also expensive. And since the toroidal coil is expensive, it is difficult to sufficiently reduce the burial pitch with respect to the conveyor belt. As a result, this is not conducive to accurately detecting the occurrence of longitudinal tears. Therefore, there is room for improvement in accurately detecting whether a longitudinal tear of the conveyor belt has occurred while having high versatility and low cost.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Laid-Open No. 2016-204070 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] An object of the present invention is to provide a longitudinal tear detection device and method for a conveyor belt that are highly versatile and low in cost and can accurately detect whether a longitudinal tear of the conveyor belt has occurred.

[0010] Technical Solution

[0011] To achieve the above object, the longitudinal tear detection device of the conveyor belt of the present invention includes a buried body buried in the conveyor belt, a detector that wirelessly communicates with the buried body in a non-contact manner with respect to the conveyor belt, and a calculation unit connected to the detector. The longitudinal tear detection device of the conveyor belt is characterized in that the buried body includes a passive IC tag, a first antenna portion connected to the IC tag, a coaxial cable having one end connected to the first antenna portion, and a second antenna portion connected to the other end of the coaxial cable. The IC tag and the first antenna portion and the second antenna portion are arranged at intervals in the width direction of the conveyor belt, so that the coaxial cable is in a state of extending in the width direction of the conveyor belt. An electromagnetic wave is transmitted from the detector to the second antenna portion, and it is judged by the calculation unit whether the detector receives an electromagnetic wave transmitted from the IC tag through the coaxial cable and the second antenna portion in response to the electromagnetic wave, and based on the judgment result, it is detected whether a longitudinal tear of the conveyor belt occurs within the range where the coaxial cable is buried.

[0012] In the longitudinal tear detection method of the conveyor belt of the present invention, a buried body buried in the conveyor belt, a detector that wirelessly communicates with the buried body in a non-contact manner with respect to the conveyor belt, and a calculation unit connected to the detector are used. The longitudinal tear detection method of the conveyor belt is characterized in that the buried body has a first antenna portion connected to one end of a coaxial cable, a second antenna portion connected to the other end, and a passive IC tag connected to the first antenna portion. The first antenna portion, the IC tag, and the second antenna portion are arranged at intervals in the width direction of the conveyor belt, so that the coaxial cable is in a state of extending in the width direction of the conveyor belt. An electromagnetic wave is transmitted from the detector to the second antenna portion, and it is judged by the calculation unit whether the detector receives an electromagnetic wave transmitted from the IC tag through the coaxial cable and the second antenna portion in response to the electromagnetic wave, and based on the judgment result, it is detected whether a longitudinal tear of the conveyor belt occurs within the range where the coaxial cable is buried.

[0013] Advantages of the Invention

[0014] According to the present invention, the buried body has a simple structure including a passive IC tag, a coaxial cable, a first antenna portion connected to both ends of the coaxial cable, and a second antenna portion. Therefore, the buried body can be composed of general components, which is advantageous in terms of cost reduction. Also, as the detector, as long as it has a specification capable of wireless communication with the buried body, it can be composed of general components, which is advantageous in terms of cost reduction.

[0015] Also, when the coaxial cable is buried at the position where the conveyor belt undergoes longitudinal tearing, the coaxial cable will break. Therefore, even if radio waves are transmitted from the detector towards the other antenna unit, no radio waves will be transmitted from the IC tag in response to these radio waves. Thus, based on whether the detector receives the radio waves transmitted through the other antenna unit, it is possible to determine whether longitudinal tearing has occurred. With the cost reduction of the buried body, compared with traditional loop antennas, etc., the burial spacing of the buried body relative to the conveyor belt can be significantly reduced, which is conducive to accurately detecting whether longitudinal tearing has occurred. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FIG. is an exemplary explanatory view of the longitudinal tear detection device for a conveyor belt of the present invention provided in a conveyor device as viewed from the side perspective of the conveyor belt.

[0017] Figure 2 is Figure 1 A - A sectional view of.

[0018] Figure 3 is Figure 1 An exemplary explanatory view of an enlarged cross - sectional view of the conveyor belt of.

[0019] Figure 4 is Figure 3 An enlarged view around the other antenna unit of.

[0020] Figure 5 is Figure 3 An enlarged view around one antenna unit of.

[0021] Figure 6 is a view from a top - down perspective of Figure 3 An exemplary explanatory view of the conveyor belt of.

[0022] Figure 7 is a view from a top - down perspective of Figure 6 An exemplary explanatory view of the buried body of.

[0023] Figure 8 is a view from a bottom - up perspective of Figure 7 An exemplary explanatory view of the buried body of.

[0024] Figure 9 is a view from a side perspective of Figure 7 An exemplary explanatory view of the buried body of.

[0025] Figure 10 An exemplary explanatory view showing another embodiment of the detection device in a sectional view of the conveyor belt.

[0026] Figure 11 is a view from a top - down perspective of Figure 10 An exemplary explanatory view of the conveyor belt of.

[0027] Figure 12 The figure is an explanatory diagram showing a modified example of the configuration of the detector in a sectional view of the conveyor belt.

[0028] Figure 13 The figure is an explanatory diagram showing a modified example of the buried state of the buried body as viewed from above the conveyor belt. Detailed Description of the Invention

[0029] Hereinafter, a longitudinal tear detection device and method for a conveyor belt of the present invention will be described based on the embodiments shown in the figures.

[0030] Figures 1 to 6 A longitudinal tear detection device 1 (hereinafter referred to as detection device 1) of the conveyor belt of the present invention shown in the figure is provided on a conveying device 14. A conveyor belt 17 is stretched between a pair of pulleys 15a and 15b of the conveying device 14. Between the pulleys 15a and 15b, the conveyor belt 17 is supported by a plurality of support rollers 16. The arrow L in the figure indicates the length direction of the conveyor belt 17, and the arrow W indicates the width direction of the conveyor belt 17.

[0031] The conveyor belt 17 is integrally formed by an upper cover rubber 20, a lower cover rubber 21, and a core layer 18 provided therebetween. The core layer 18 has a plurality of steel cord 19 arranged side by side in the width direction W and extending in the length direction L. The core layer 18 is not limited to the steel cord 19, and may also be a fiber layer made of canvas or the like. If necessary, other members are provided on the conveyor belt 17.

[0032] On the carrier side of the conveying device 14, the lower cover rubber 21 of the conveyor belt 17 is supported by the support roller 16 so that the conveyor belt 17 has a trough shape with the central portion in the width direction W protruding downward. The conveyed object C is placed on the upper surface of the upper cover rubber 20 and conveyed. On the return side of the conveying device 14, the upper cover rubber 20 of the conveyor belt 17 is supported by the support roller 16 in a flat state.

[0033] The detection device 1 detects a crack (so-called longitudinal tear) extending in the length direction L in the conveyor belt 17. The detection device 1 includes a buried body 2 buried in the conveyor belt 17, a detector 10, and a calculation unit 12. In this embodiment, a warning device 13 is also provided. The warning device 13 can be provided arbitrarily.

[0034] A plurality of buried bodies 2 are buried at intervals in the length direction L. Wireless communication is performed between each buried body 2 and the detector 10. In the present invention, the radio wave frequency used for wireless communication is mainly the UHF band (varies by country, but in the range of 860 MHz or more and 930 MHz or less, in Japan it is 915 MHz or more and 930 MHz or less), and the HF band (13.56 MHz) can also be used.

[0035] AsFigures 7 to 9 As shown, the buried body 2 has a passive IC tag 3, one-side antenna portion 4 connected to the IC tag 3, the other-side antenna portion 5, and a coaxial cable 6. The one-side antenna portion 4 is connected to one end portion of the coaxial cable 6, and the other-side antenna portion 5 is connected to the other end portion of the coaxial cable 6. In this embodiment, the buried body 2 is buried in the lower cover rubber 21, but it can also be set to a specification buried in the upper cover rubber 20. In order to protect the buried body 2 from the influence of the conveyed object C etc., it is preferable to bury the buried body 2 in the lower cover rubber 21 rather than the upper cover rubber 20.

[0036] The IC tag 3 adopts a generally circulated specification. For example, an RFID tag can be used. Preferably, the size specification of the IC tag 3 is as small as possible. For example, the longitudinal dimension is 15 mm or less, more preferably 10 mm or less, the lateral dimension is 60 mm or less, more preferably 50 mm or less, and the thickness is 1 mm or less, more preferably 0.5 mm or less. And, an IC tag 3 with a heat-resistant temperature of about 200 °C is used.

[0037] In the IC tag 3, any necessary information other than the inherent information such as the identification number of the tag is stored. The IC tag 3 is arranged in a state of overlapping with the one-side antenna portion 4 and is connected to the one-side antenna portion 4.

[0038] The one-side antenna portion 4 has antenna plates 4a, 4b made of metal formed on a substrate. The antenna plates 4a, 4b are spaced apart from each other. The other-side antenna portion 5 has antenna plates 5a, 5b made of metal formed on a substrate. The antenna plates 5a, 5b are spaced apart from each other.

[0039] Preferably, the size specification of the one-side antenna portion 4 is as small as possible. For example, the longitudinal dimension is 15 mm or less, more preferably 10 mm or less, the lateral dimension is 60 mm or less, more preferably 50 mm or less, and the thickness is 1 mm or less, more preferably 0.5 mm or less. Preferably, the size specification of the other-side antenna portion 5 is as small as possible. For example, the longitudinal dimension is 15 mm or less, more preferably 10 mm or less, the lateral dimension is 150 mm or less, more preferably 120 mm or less, and the thickness is 1 mm or less, more preferably 0.5 mm or less. In this embodiment, the area of the one-side antenna portion 4 is about 50%, smaller than that of the other-side antenna portion 5, but it can also have the same area as the other-side antenna portion 5.

[0040] The coaxial cable 6 adopts a generally circulated specification. The coaxial cable 6 has a core wire 7 as an inner conductor, an insulating layer 8 covering the periphery of the core wire 7, and an outer conductor layer 9 covering the periphery of the insulating layer 8. The outer diameter of the coaxial cable 6 is, for example, about 1 mm or more and 3 mm or less.

[0041] At one end of the coaxial cable 6, the core wire 7 is connected to one antenna board 4a by welding or the like, and is not connected to the other antenna board 4b. Also, the outer conductor layer 9 is connected to the other antenna board 4b by welding, and is not connected to one antenna board 4a. At the other end of the coaxial cable 6, the core wire 7 is connected to one antenna board 5a by welding or the like, and is not connected to the other antenna board 5b. Also, the outer conductor layer 9 is connected to the other antenna board 5b by welding or the like, and is not connected to one antenna board 5a. Each exposed surface of the one-side antenna portion 4 and the other-side antenna portion 5 in total is covered with an insulator.

[0042] The IC tag 3 and the one-side antenna portion 4 are buried in one end portion in the width direction W of the conveyor belt 17, and the other-side antenna portion 5 is buried in the other end portion in the width direction W of the conveyor belt 17. The IC tag 3 and the one-side antenna portion 4 and the other-side antenna portion 5 are arranged so as to be spaced apart in the width direction W. The coaxial cable 6 is buried in the conveyor belt 17 in a state of extending in the width direction W. In this embodiment, as Figure 6 shown, the coaxial cable 6 extends parallel to the width direction W and extends at a substantially 0° inclination angle with respect to the width direction W. Preferably, each coaxial cable 6 extends so as to cover the entire width of the core layer 18.

[0043] When manufacturing the conveyor belt 17, the embedding body 2 is placed in the unvulcanized lower cover rubber 21 or the upper cover rubber 20 in the molding process, and then through the vulcanization process, the embedding body 2 embedded in the conveyor belt 17 and the lower cover rubber 21 or the upper cover rubber 20 are integrally formed. In order to firmly bond the one-side antenna portion 4 and the other-side antenna portion 5 to the embedded lower cover rubber 21 or the upper cover rubber 20, in the molding process of the conveyor belt 17, a fiber layer impregnated with an impregnating liquid or the like is interposed between the bonding surfaces of the lower cover rubber 21 or the upper cover rubber 20.

[0044] Each embedding body 2 is buried at intervals of 5 m or more and 20 m or less in the length direction L, for example. That is, preferably, the embedding interval P of the embedding body 2 is in the range of 5 m or more and 20 m or less, and more preferably is an equal interval. When considering the detection accuracy and cost of longitudinal tearing, etc., it is appropriate that the embedding interval P of the embedding body 2 is about 10 m. In addition, in the drawings, the embedding interval P is shown shorter than the original.

[0045] The detector 10 is provided at a position near the conveyor belt 17 and performs wireless communication with the embedding body 2 without contacting the conveyor belt 17. The detector 10 has a transmitting portion for the radio wave R1 and a receiving portion for the radio wave R2. The detector 10 transmits the radio wave R1 to the other-side antenna portion 5. And, in response to the radio wave R1, it receives the radio wave R2 transmitted from the other-side antenna portion 5 and acquires the information of the IC tag 3 transmitted together with the radio wave R2.

[0046] As the detector 10, a generally circulated specification that enables wireless communication between passive RFID tags and the like is adopted. Thus, the IC tag 3 and the detector 10 constitute an RFID (Radio Frequency Identification) system.

[0047] In this embodiment, the detector 10 can be provided on the return side of the conveyor 14, but can also be provided on the carrier side. The distance between the detector 10 and the other antenna unit 5 when they are closest to each other is set, for example, within 1 m. That is, the detector 10 is preferably provided at a position where the distance between the detector 10 and the other antenna unit 5 is 1 m or less when the other antenna unit 5 passes in front of the detector 10.

[0048] The calculation unit 12 is connected to the detector 10 by wire or wirelessly. A computer or the like is used as the calculation unit 12. The information obtained by the detector 10 is input into the calculation unit 12. And, in the calculation unit 12, the buried position data (at least the position data in the longitudinal direction L) of each IC tag 3 in the conveyor belt 17 is stored.

[0049] The warning device 13 is used to notify the surroundings of the occurrence of a longitudinal tear. As the warning device 13, an alarm device, a warning light, a warning indicator, etc. can be cited. The warning device 13 is connected to the calculation unit 12 by wire or wirelessly, and its operation is controlled by the calculation unit 12. When it is determined that a longitudinal tear has occurred, the calculation unit 12 activates the warning device 13.

[0050] Next, an example of the steps of a method for using the detection device 1 to detect whether a longitudinal tear has occurred is described.

[0051] As Figures 1 to 3 shown, during the operation of the conveyor 14 (during the operation of the conveyor belt 17), a radio wave R1 is transmitted from the detector 10 to the other antenna unit 5. If the buried object 2 is intact, this radio wave R1 is input into the IC tag 3 through the other antenna unit 5, the coaxial cable 6, and the one antenna unit 4. The IC tag 3 transmits a radio wave R2 in accordance with the input radio wave R1. This radio wave R2 is transmitted from the one antenna unit 4, the coaxial cable 6, and the other antenna unit 5 to the detector 10. By receiving this radio wave R2, the detector 10 acquires the information stored in the IC tag 3 transmitted together with the radio wave R2. The information obtained by the detector 10 is input into the calculation unit 12.

[0052] On the other hand, when a longitudinal tear occurs in the conveyor belt 17, the coaxial cable 6 breaks within the range where the longitudinal tear has occurred. As a result, even if a radio wave R1 is transmitted from the detector 10 to the other antenna unit 5, the IC tag 3 does not transmit a radio wave R2 in response to the radio wave R1. Therefore, the detector 10 does not receive the radio wave R2, and the information obtained by the detector 10 is not input into the calculation unit 12.

[0053] Based on whether there is information input from the detector 10, the calculation unit 12 determines whether the detector 10 has received the radio wave R2. When information is input from the detector 10 to the calculation unit 12, it is determined that the detector 10 has received the radio wave R2. In this case of the judgment result, it is inferred that the buried object 2 is intact, and it is determined that no longitudinal tear has occurred within the range where the coaxial cable 6 is buried (the occurrence of longitudinal tear is not detected).

[0054] When no information is input from the detector 10 to the calculation unit 12, it is determined that the detector 10 has not received the radio wave R2. In this case of the judgment result, it is inferred that the coaxial cable 6 is broken, and it is determined that a longitudinal tear has occurred within the range where the coaxial cable 6 is buried (the occurrence of longitudinal tear is detected).

[0055] When the occurrence of longitudinal tear is detected, the warning device 13 is activated to notify the surroundings of the occurrence of longitudinal tear. Since the buried position in the conveyor belt 17 of each IC tag 3 is stored in the calculation unit 12, the buried position of the IC tag 3 for which the unique information cannot be obtained is clearly known. Therefore, the position (range) of the conveyor belt 17 where longitudinal tear is occurring can be specified.

[0056] The management personnel who recognize the occurrence of longitudinal tear stop the operation of the conveyor belt 17 at an appropriate time and take measures such as repairing the range where longitudinal tear has occurred. After finishing this measure, the operation of the conveyor belt 17 is restarted.

[0057] This detection device 1 has a simple structure. Among them, the buried object 2 has a passive IC tag 3, a coaxial cable 6, one side antenna part 4 connected to both ends of the coaxial cable 6, and the other side antenna part 5. Therefore, the buried object 2 can be composed of general components, which is advantageous in terms of cost reduction. And the detector 10 only needs to be of a specification capable of wireless communication between these buried objects 2, so it can be composed of general components, which is advantageous in terms of cost reduction.

[0058] Moreover, since the coaxial cable 6 breaks at the position where longitudinal tear occurs in the conveyor belt, even if the radio wave R1 is emitted from the detector 10 to the other side antenna part 5, the radio wave R2 will not be emitted from the IC tag 3 in response to this radio wave R1. Therefore, based on whether the detector 10 has received the radio wave R2 emitted through the other side antenna part 5, it is possible to accurately grasp whether longitudinal tear has occurred. With the cost reduction of the buried object 2, under the constraint of a predetermined cost, the burial spacing P of the buried object 2 relative to the conveyor belt 17 can be small enough compared with traditional loop antennas, etc., so it is beneficial to accurately detect whether longitudinal tear has occurred.

[0059] Figure 8 、 Figure 9Another embodiment of the detection device 1 shown in the figure has a tag-side detector 11 added to the previous embodiment. The other structures are basically the same as those of the previous embodiment.

[0060] The tag-side detector 11 is disposed near the conveyor belt 10 and performs wireless communication with the buried body 2 in a manner that does not contact the conveyor belt 17. The tag-side detector 11 has a transmission unit for radio wave R3 and a reception unit for radio wave R4. The tag-side detector 11 transmits radio wave R3 to the one antenna unit 4. Further, the tag-side detector 11 receives radio wave R4 transmitted from the IC tag 3 via the one antenna unit 4 in response to radio wave R3, and acquires the information stored in the IC tag 3 transmitted together with radio wave R4. In addition, preferably, radio waves R3 and R4 have different frequencies from radio waves R1 and R2.

[0061] Similar to the detector 10, the tag-side detector 11 adopts a generally used specification capable of performing wireless communication between passive RFID tags and the like. The tag-side detector 11 and the detector 10 may have the same specification. Thus, the IC tag 3 and the tag-side detector 11 constitute an RFID (Radio Frequency Identification) system.

[0062] In this embodiment, the tag-side detector 11 may be disposed on the return side of the conveying device 14, but may also be disposed on the carrier side. The distance between the tag-side detector 11 and the one antenna unit 4 when they are closest to each other is set, for example, within 1 m. That is, the tag-side detector 11 is preferably disposed at a position where the distance between the tag-side detector 11 and the one antenna unit 4 is 1 m or less when the one antenna unit 4 passes in front of the tag-side detector 11. The information obtained by the tag-side detector 11 is input to the calculation unit 12.

[0063] Even if the coaxial cable 6 is not broken, for example, when the IC tag 3 malfunctions, even if radio wave R1 is transmitted from the detector 10, radio wave R2 will not be transmitted from the IC tag 3 in response to radio wave R1. Therefore, in the previous embodiment, there is a risk of determining that a longitudinal tear has occurred even if the coaxial cable 6 is broken. To avoid such false detection, in this embodiment, the calculation unit 12 determines the degree of the reception intensity of radio wave R4 transmitted from the IC tag 3 via the one antenna unit 4 in response to radio wave R3 based on the tag-side detector 11.

[0064] When the IC tag 3 is damaged, even if radio wave R3 is transmitted from the tag-side detector 11 to one antenna unit 4, the IC tag 3 does not transmit radio wave R4 in response to radio wave R3. Therefore, the tag-side detector 11 does not receive radio wave R4, and the information obtained by the tag-side detector 11 is not input to the calculation unit 12. Therefore, when the calculation unit 12 determines that the tag-side detector 11 has not received radio wave R4 (the reception intensity of radio wave R4 is 0), it is determined that the IC tag 3 is damaged.

[0065] On the other hand, when the IC tag 3 is intact and the coaxial cable 6 is broken, compared with the case where the coaxial cable 6 is intact, the intensity of radio wave R4 transmitted from the IC tag 3 in response to radio wave R3 changes (becomes weaker). Therefore, this characteristic that the intensity of radio wave R4 changes is utilized.

[0066] When the coaxial cable 6 is intact, the intensity (reference intensity) of radio wave R4 transmitted from the IC tag 3 in response to radio wave R3 is grasped in advance and stored in the calculation unit 12. Then, the intensity when the tag-side detector 11 receives radio wave R4 transmitted from the IC tag 3 in response to radio wave R3 is compared with the reference intensity. Based on the comparison result, it is possible to grasp whether the coaxial cable 6 is broken. When the intensity when the tag-side detector 11 receives radio wave R4 is weaker than the reference intensity, it is determined that the coaxial cable 6 is broken. Therefore, by combining the determination of whether radio wave R2 is received by the detector 10 and the determination of the degree of the reception intensity of radio wave R4 by the tag-side detector 11, it is possible to more reliably grasp that the coaxial cable 6 is broken. As a result, it is beneficial to accurately detect the occurrence of longitudinal tearing.

[0067] In this way, based on the determination result of the degree of the reception intensity of radio wave R4 by the tag-side detector 11, the damaged state of the coaxial cable 6 or the damaged state of the IC tag 3 can be grasped. The buried body 2 is a consumable that fails after a specific period. By using the tag-side detector 11, it is possible to grasp the non-intact buried body 2 and its buried position, so it is very beneficial for effectively maintaining the buried body 2.

[0068] One antenna unit 4 and the other antenna unit 5 can be made to protrude more outward in the width direction W than the steel cord 19 provided closest to the end side in the width direction W. With this structure, radio waves for wireless communication are less likely to be affected by the core layer 18 (steel cord 19), and in some cases, the wireless communication distance with the detector 10 or the tag-side detector 11 can be increased.

[0069] In each of the above embodiments, the detector 10 and the tag-side detector 11 are provided at positions inside the width direction W of the conveyor belt 17, but as Figure 12As shown, it can also be set at a position outside the width direction W. In some cases, sufficient space for setting the detector 10 or the label-side detector 11 cannot be ensured inside the conveying device 14. Under such conditions, the detector 10 or the label-side detector 11 can be set in the open space outside the conveyor belt 17. When set in such a structure, the maintenance work of the detector 10 or the label-side detector 11 can also be easily carried out.

[0070] As Figure 13 shown, the coaxial cable 6 can not only extend parallel in the width direction W, but also extend obliquely with respect to the width direction W. In Figure 13 it, the coaxial cable 6 extends with an inclination angle g of -30° with respect to the width direction W. In addition, in Figure 13 it, a negative (-) inclination angle means inclined downward to the right, and a positive (+) inclination angle means inclined upward to the right.

[0071] For example, the coaxial cable 6 can extend with an inclination angle g of +45° or less and -45° or less with respect to the width direction W. When the coaxial cable 6 extends obliquely with respect to the width direction W, compared with the case where the inclination angle g is zero, it is beneficial to further reduce the change (smoothly change) in the bending stiffness when the conveyor belt 17 passes around the pulleys 15a and 15b.

[0072] Description of Reference Numerals

[0073] 1: Detection device

[0074] 2: Embedded body

[0075] 3: IC tag

[0076] 4: One-side antenna part

[0077] 4a, 4b: Antenna plates

[0078] 5: The other-side antenna part

[0079] 5a, 5b: Antenna plates

[0080] 6: Coaxial cable

[0081] 7: Core wire (inner conductor)

[0082] 8: Insulation layer

[0083] 9: Outer conductor layer

[0084] 10: Detector

[0085] 11: Label-side detector

[0086] 12: Calculation unit

[0087] 13: Warning device

[0088] 14: Conveyor device

[0089] 15a, 15b: Pulley

[0090] 16: Supporting roller

[0091] 17: Conveyor belt

[0092] 18: Core layer

[0093] 19: Steel cord

[0094] 20: Upper cover rubber

[0095] 21: Lower cover rubber

[0096] C: Conveyed object

Claims

1. A longitudinal tear detection device for a conveyor belt, the device comprising a buried body buried in the conveyor belt, a detector that wirelessly communicates with the buried body in a manner that does not contact the conveyor belt, and a calculation unit connected to the detector. The longitudinal tear detection device for the conveyor belt is characterized in that, The longitudinal tear detection device for the conveyor belt is configured to: The buried body includes a passive IC tag, a first antenna portion connected to the IC tag, a coaxial cable having one end connected to the first antenna portion, and a second antenna portion connected to the other end of the coaxial cable. The IC tag and the first antenna portion are arranged at intervals in the width direction of the conveyor belt, such that the coaxial cable is in a state of extending along the width direction of the conveyor belt. Radio waves are emitted from the detector to the second antenna portion, and it is judged by the calculation unit whether the detector receives radio waves emitted from the IC tag through the coaxial cable and the second antenna portion in response to the radio waves, and based on the judgment result, it is detected whether a longitudinal tear of the conveyor belt occurs within the range where the coaxial cable is buried.

2. The longitudinal tear detection device for a conveyor belt according to claim 1, wherein, The buried body is buried in the lower cover rubber of the conveyor belt.

3. The longitudinal tear detection device for a conveyor belt according to claim 1 or 2, wherein, The longitudinal tear detection device for the conveyor belt is configured to: As the detector, it further includes a tag-side detector that wirelessly communicates with the buried body in a manner that does not contact the conveyor belt by sending radio waves to the first antenna portion. Radio waves are emitted from the tag-side detector to the first antenna portion, and the calculation unit judges the reception intensity level of the tag-side detector of the radio waves emitted from the IC tag through the first antenna portion in response to the radio waves, and based on the judgment result, the damage state of the coaxial cable or the damage state of the IC tag is grasped.

4. The longitudinal tear detection device for a conveyor belt according to claim 1 or 2, wherein, The buried bodies are buried at intervals of 5 m or more and 20 m or less in the length direction of the conveyor belt.

5. The longitudinal tear detection device for a conveyor belt according to claim 1 or 2, wherein, The coaxial cable extends at an inclination angle of +45° or less and -45° or less with respect to the width direction of the conveyor belt.

6. A longitudinal tear detection method for a conveyor belt, in the detection method, a buried body buried in the conveyor belt, a detector that wirelessly communicates with the buried body in a manner that does not contact the conveyor belt, and a calculation unit connected to the detector are used. The longitudinal tear detection method for the conveyor belt is characterized in that, The buried body has one side antenna portion connected to one end portion of the coaxial cable, the other side antenna portion connected to the other end portion, and a passive IC tag connected to the one side antenna portion. The one side antenna portion, the IC tag, and the other side antenna portion are arranged at intervals in the width direction of the conveyor belt so that the coaxial cable is in a state of extending in the width direction of the conveyor belt. Radio waves are emitted from the detector to the other side antenna portion, and it is judged by the calculation unit whether the detector receives radio waves emitted from the IC tag through the coaxial cable and the other side antenna portion in response to the radio waves, and based on the judgment result, it is detected whether a longitudinal tear of the conveyor belt occurs within the range where the coaxial cable is buried.

Images