Conveyer belt management system and method

Abstract

Provided are a conveyor belt management system and a method with which the state of a conveyor belt under various use conditions can be more reliably ascertained. In the present invention, a radio wave-type IC tag 2A and an electromagnetic coupling-type IC tag 2B are installed as a passive-type IC tag 2 on a conveyor belt 13. In response to transmission radio waves R1 transmitted from a detector 7 toward the IC tags 2A, 2B of the conveyor belt 13 mounted on a conveyor device 10, return radio waves R2 returned from the respective IC tags 2A, 2B are received by the detector 7. The operation state of the conveyor belt 13 is ascertained by an arithmetic device 8 using the return radio waves R2. Alternatively, detection data from a sensor unit 6 connected to the IC tags 2A, 2B is transmitted from the IC tags 2A, 2B to the detector 7 by the return radio waves R2 and input to the arithmetic device 8, and the state of the conveyor belt 13 is ascertained by the arithmetic device 8 on the basis of the detection data.

Description

Conveyor belt management system and method

[0001] The present invention relates to a system and method for managing a conveyor belt, and more particularly to a system and method for managing a conveyor belt that can more reliably grasp the state of the conveyor belt under various conditions of use.

[0002] Various systems for managing conveyor belts that run stretched between pulleys of a conveyor device have been proposed (see, for example, Patent Document 1). The management system proposed in Patent Document 1 performs wireless communication between RFID tags (IC tags) embedded in the conveyor belt and a reader, and data transmitted from the RFID tags is acquired by the reader. The various data acquired by the reader is then transmitted to a predetermined terminal device and shared.

[0003] In such conventional management systems, IC tags that use a radio wave communication method are often used. Conveyor belts that transport crushed stone, soil, other mineral materials, and processed products thereof operate under a variety of operating conditions. The wireless communication environment between the IC tag and the reader also changes depending on the operating conditions of the conveyor belt. Therefore, if only IC tags with the same communication method are used, wireless communication between the IC tag and the reader becomes impossible under certain operating conditions of the conveyor belt, resulting in the problem of being unable to obtain data from the IC tag.

[0004] Japanese Patent Application Publication No. 2022-23840

[0005] That is, if all IC tags attached to a conveyor belt use the same communication method, it may not be possible to adequately grasp the state of the conveyor belt under various usage conditions. Therefore, there is room for improvement in order to more reliably grasp the state of the conveyor belt under various usage conditions.

[0006] An object of the present invention is to provide a system and method for managing a conveyor belt that can more reliably grasp the state of the conveyor belt under various usage conditions.

[0007] In order to achieve the above object, the conveyor belt management system of the present invention comprises a passive IC tag installed on the conveyor belt, a detector that communicates wirelessly with the IC tag, and a computing device communicatively connected to the detector, wherein the detector transmits radio waves toward the IC tag installed on the conveyor belt attached to the conveyor device and receives reply radio waves returned from the IC tag in response to the transmitted radio waves, and the computing device grasps the condition of the conveyor belt using the reply radio waves, and is characterized in that two types of IC tags are used: a radio wave type IC tag and an electromagnetic coupling type IC tag.

[0008] The conveyor belt management method of the present invention comprises attaching a passive IC tag to a conveyor belt, transmitting radio waves from a detector that wirelessly communicates with the IC tag toward the IC tag attached to the conveyor belt that is attached to a conveyor device, receiving reply radio waves returned from the IC tag in response to the transmitted radio waves by the detector, and using the reply radio waves to determine the condition of the conveyor belt by a computing device, and is characterized in that two types of IC tags are used: a radio wave type IC tag and an electromagnetic coupling type IC tag.

[0009] In the present invention, two types of passive IC tags are used on a conveyor belt: a radio wave IC tag and an electromagnetic coupling IC tag. The IC tags, which use different communication methods, have different communication characteristics when wirelessly communicating with the detector. Therefore, even in various wireless communication environments, the detector can receive the reply radio waves from IC tags using at least one of the two communication methods. In other words, under various wireless communication environments resulting from differences in the usage conditions of the conveyor belt, the risk of communication failure is reduced for both the radio wave IC tag and the detector and the electromagnetic coupling IC tag and the detector. Therefore, using the reply radio waves is advantageous for more reliably understanding the status of a conveyor belt under various usage conditions.

[0010] FIG. 1 is an explanatory diagram illustrating an overall overview of an embodiment of a conveyor belt management system. FIG. 2 is an explanatory diagram illustrating a side view of a conveyor device to which the management system of FIG. 1 is applied. FIG. 3 is a cross-sectional view taken along the line A-A in FIG. 2. FIG. 4 is a view taken along the line B-B in FIG. 3. FIG. 5 is an explanatory diagram illustrating a plan view of a radio wave-type IC tag. FIG. 6 is an explanatory diagram illustrating a front view of the IC tag of FIG. 5. FIG. 7 is an explanatory diagram illustrating a plan view of an electromagnetic coupling-type IC tag. FIG. 8 is an explanatory diagram illustrating a front view of the IC tag of FIG. 7. FIG. 9 is an explanatory diagram illustrating a cross-sectional view of a conveyor belt showing wireless communication between an IC tag and a detector. FIG. 10 is a graph schematically illustrating the change in the running speed of a conveyor belt over time. FIG. 11 is a graph schematically illustrating the relationship between the position of an IC tag relative to the detection position and the received signal strength of the reply radio wave. FIG. 12 is a graph illustrating the correlation between the electrical resistance value of the IC tag at startup and the temperature of the IC tag. FIG. 13 is an explanatory diagram illustrating the temperature of the conveyor belt at each detection position. FIGS. 14A to 14D are explanatory diagrams illustrating the arrangement patterns of two types of IC tags in a plan view of the conveyor belt. FIGS. 15A and 15B are explanatory diagrams illustrating yet another arrangement pattern of two types of IC tags in a plan view of the conveyor belt. FIG. 16 is an explanatory diagram illustrating a side view of a conveyor device to which another embodiment of the management system is applied. FIG. 17 is an explanatory diagram illustrating a cross-sectional view of the conveyor belt near the detector of FIG. 16. FIG. 18 is an explanatory diagram illustrating a plan view of the detector and conveyor belt of FIG. 17. FIG. 19 is an explanatory diagram illustrating a plan view of the IC tag and sensor unit of FIG. 18. FIG. 20 is an explanatory diagram illustrating a front view of the IC tag and sensor unit of FIG. 19. FIG. 21 is an explanatory diagram illustrating a plan view of a modified example of the sensor unit of FIG. 19. Fig. 22 is an explanatory diagram illustrating an enlarged cross-sectional view of a portion of the conveyor belt in which the IC tag with sensor unit of Fig. 21 is embedded. Fig. 23 is an explanatory diagram illustrating a cross-sectional view of a conveyor belt to which yet another embodiment of the management system is applied. Fig. 24 is an explanatory diagram illustrating a plan view of the detector and conveyor belt of Fig. 23. Fig. 25 is an explanatory diagram illustrating a plan view of a modified example of the sensor unit of Fig. 24.

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A conveyor belt management system and method according to the present invention will be described below based on the embodiments shown in the drawings.

[0012] The embodiment of a conveyor belt management system 1 illustrated in FIGS. 1 to 4 is used to monitor the status of a conveyor belt 13 attached to a conveyor device 10. This management system 1 includes passive IC tags 2 (2A, 2B) attached to the conveyor belt 13, detectors 7 (7A, 7B, 7C), and a computing device 8 communicatively connected to the detectors 7 wirelessly or via a wire. The detectors 7 receive reply radio waves R2 returned from the IC tags 2 in response to radio waves R1 transmitted from the respective detectors 7. As illustrated in FIG. 1, in this embodiment, the computing device 8 is connected via a communication network such as the Internet to terminal devices 9 (9a, 9b, 9c, 9d), such as computers or smartphones, located at a location (remote location) away from the installation site of the conveyor device 10.

[0013] The conveyor device 10 has a pair of pulleys 11a, 11b and a number of support rollers 12 arranged between the pulleys 11a, 11b. A conveyor belt 13 is stretched between the pulleys 11a, 11b and supported by the number of support rollers 12 between the pulleys 11a, 11b. The conveyor belt 13 runs by rotating the drive pulley 11a. In the figure, arrow L indicates the longitudinal direction of the conveyor belt 13, and arrow W indicates the width direction of the conveyor belt 13.

[0014] The conveyor belt 13 is constructed by integrating an upper cover rubber 16, a lower cover rubber 17, and one traction layer 14 disposed therebetween by vulcanization bonding. In this embodiment, the traction layer 14 is constructed of a large number of steel cords 15 arranged horizontally in the width direction W. The conveyor belt 13 may be equipped with other members as needed. The traction layer 14 is not limited to the steel cords 15, and may also be constructed of canvas. When the traction layer 14 is constructed of canvas, for example, four to eight layers of canvas are laminated as the traction layer 14 depending on the performance required of the conveyor belt 13.

[0015] On the carrier side of the conveyor device 10, the lower cover rubber 17 of the conveyor belt 13 is supported by the support rollers 12, so that the conveyor belt 13 has a trough shape with the center portion in the width direction W protruding downward. The conveyed object C is placed on the upper surface of the upper cover rubber 16 and conveyed. On the return side of the conveyor device 10, the upper cover rubber 16 of the conveyor belt 13 is supported in a flat state by the support rollers 12.

[0016] Two types of IC tags 2 are used: a radio wave type IC tag 2A shown in Figures 5 and 6, and an electromagnetic coupling type IC tag 2B shown in Figures 7 and 8. Each of the IC tags 2A and 2B has an IC chip 3a and an antenna section 3b. The IC chip 3a stores identification information that distinguishes the IC tag 2 from other IC tags 2. Other information can also be stored in the IC chip 3a, but in this management embodiment, it is sufficient that at least the identification information of the IC tag 2 is stored in the IC chip 3a.

[0017] The IC tags 2 (2A, 2B) may be of a generally available specification, and general-purpose RFID tags may be used. The size of the IC tags 2 (2A, 2B) is, for example, 200 mm 2 Over 6000mm 2 Less than 300 mm, more preferably 2 2700mm or more 2 The thickness is, for example, 0.01 mm or more and 0.4 mm or less, more preferably 0.03 mm or more and 0.15 mm or less. The heat resistance temperature of the IC tag 2 is, for example, about 250°C.

[0018] In the radio wave type IC tag 2A shown in Figures 5 and 6, the IC chip 3a and antenna unit 3b are connected via a conductor (wiring). The antenna unit 3b extends from the IC chip 3a in a bent state on both sides of the outside of the IC chip 3a. The IC chip 3a and antenna unit 3b are disposed on a substrate 4 and covered by an insulating layer 5. The antenna unit 3b receives radio waves R1 transmitted from the detector 7, and power generated by the transmitted radio waves R1 is supplied to the IC chip 3a through the conductor connecting the antenna unit 3b and the IC chip 3a, activating the IC tag 2A. Communication between the IC chip 3a and antenna unit 3b takes place through this conductor.

[0019] In the electromagnetic coupling type IC tag 2B illustrated in Figures 7 and 8, the IC chip (IC module) 3a and antenna portion 3b are spaced apart, providing a non-contact structure. The antenna portion 3b has a loop that surrounds the entire outer periphery of the IC chip 3a and extends from the loop in a bent state on both sides of the loop. The IC chip 3a and antenna portion 3b are each covered with an insulating layer 5. When the antenna portion 3b receives the transmitted radio waves R1 from the detector 7, a magnetic field is formed within the loop. This magnetic field forms an electromagnetic coupling between the spiral antenna inside the IC chip 3a and the antenna portion 3b, and the IC tag 2B is activated by the power generated by the transmitted radio waves R1. Communication between the IC chip 3a and the antenna portion 3b is achieved through the electromagnetic coupling between the spiral antenna (IC chip 3a) and the antenna portion 3b.

[0020] In this embodiment, as shown in Figure 3, the IC tag 2 is embedded in the lower cover rubber 17. The IC tag 2 may be installed at another position on the conveyor belt 13, for example, in the upper cover rubber 16 or, in the case of a traction layer 14 made of multiple layers of canvas, in the traction layer 14. In order to protect the IC tag 2 from the transported goods C, etc., it is preferable to embed the IC tag 2 in the lower cover rubber 17 or the traction layer 14 rather than in the upper cover rubber 16.

[0021] When manufacturing the conveyor belt 13, the IC tag 2 is placed in the unvulcanized lower cover rubber 17 or unvulcanized upper cover rubber 16, or the traction layer 14 made of canvas in the molding process to form a molded product. Then, by vulcanizing this molded product, the IC tag 2 is embedded in the conveyor belt 13 in which the traction layer 14, upper cover rubber 16, and lower cover rubber 17 are integrated.

[0022] The method of attaching the IC tag 2 to the conveyor belt 13 is not limited to the method of embedding the IC tag 2 in the conveyor belt 13 during its manufacture, as described above, but it can also be attached to the conveyor belt 13 after it has been manufactured. For example, after placing the IC tag 2 at a desired position on the manufactured conveyor belt 13, the IC tag 2 is covered with a rubber material, and the IC tag 2 and the rubber material are bonded to the conveyor belt 13. A known adhesive or vulcanization adhesive can be used for this bonding. If the method of attaching the IC tag 2 to the conveyor belt 13 is adopted, it becomes possible to apply this management system 1 to existing conveyor belts 13.

[0023] At least one of each IC tag 2A, 2B needs to be installed on the conveyor belt 13, but it is preferable that a plurality of IC tags 2 are installed at intervals in the longitudinal direction L. The IC tags 2 are embedded in the conveyor belt 13 at intervals TL of, for example, 5 m or more and 20 m or less in the longitudinal direction L. That is, the installation pitch TL of the IC tags 2 is preferably in the range of 5 m or more and 20 m or less, and for example, approximately 10 m is appropriate. It is preferable that the installation pitch TL of the IC tags 2 be equal.

[0024] 9, the detector 7 communicates wirelessly with the IC tag 2 attached to the conveyor belt 13 in a non-contact manner. The detector 7 has a transmitter 7s and a receiver 7r. The transmitter 7s transmits an outgoing radio wave R1 toward the IC tag 2. The receiver 7r receives a reply radio wave R2 returned from the IC tag 2 (antenna unit 3b) in response to the outgoing radio wave R1, and acquires the identification information of the IC tag 2 stored in the IC chip 3a transmitted together with the reply radio wave R2.

[0025] The detector 7 is of a generally available specification that allows wireless communication with passive RFID tags and the like. The radio wave frequency used for wireless communication between the IC tag 2 and the detector 7 is mainly the UHF band (a range of 860 MHz to 930 MHz, which varies by country; 915 MHz to 930 MHz in Japan), although the HF band (13.56 MHz) is sometimes used. The wireless communication between the radio wave type IC tag 2A and the detector 7 and the wireless communication between the electromagnetic coupling type IC tag 2B and the detector 7 are adjusted and set so that they can communicate at the same frequency.

[0026] The detector 7 is disposed at a detection position P in the conveyor device 10, close to the conveyor belt 13. The detector 7 is disposed at at least one detection position P. It is preferable that the detector 7 is disposed at a plurality of detection positions P spaced apart in the longitudinal direction L (for example, about 10 m to 30 m) rather than at only one detection position P. The detector 7 may also be disposed at a plurality of detection positions P spaced apart in the width direction.

[0027] The detector 7 is not limited to being disposed on the carrier side of the conveyor device 10 as in this embodiment, but can also be disposed on the return side, or on both the carrier side and the return side. The distance between the detector 7 and the antenna unit 3b when they are closest to each other is set to, for example, within 1 m. That is, the detector 7 is installed at a detection position P where the distance between the detector 7 and the antenna unit 3b is 1 m or less when the antenna unit 3b passes near the detector 7. In this embodiment, each detector 7 is disposed at one end of the conveyor belt 13 in the width direction W, as shown in FIG. 4. The widthwise position of the detector 7 is preferably aligned with the widthwise position of the IC tag 2 on the conveyor belt 13.

[0028] A known computer or computer server is used as the computing device 8. Information detected and acquired by the detector 7 is sequentially input to the computing device 8. The computing device 8 performs various arithmetic processing based on the various pieces of input information. The computing device 8 also has a transmission function for transmitting various pieces of information (data) to desired terminal devices 9 (9a to 9d) connected via a communication network such as the Internet.

[0029] Next, an example of the procedure for determining the operating state of the conveyor belt 13 using the management system 1 will be described.

[0030] 9, each detector 7 (transmitter 7s) transmits an outgoing radio wave R1 toward the IC tag 2. When each IC tag 2 approaches its corresponding detector 7 due to the movement of the conveyor belt 13, the antenna 3b receives the outgoing radio wave R1, and the IC tag 2 is activated by this outgoing radio wave R1.

[0031] The activated IC tag 2 sequentially returns reply radio waves R2 to the detector 7 in response to the transmitted radio waves R1. These reply radio waves R2 are returned from the IC tag 2 to the detector 7 via the antenna unit 3b. The identification information of the IC tag 2 stored in the IC chip 3a is transmitted to the detector 7 using the reply radio waves R2 and received by the receiver unit 7r. Therefore, the detector 7 sequentially acquires the identification information of the IC tag 2 by receiving the reply radio waves R2.

[0032] The calculation device 8 uses the input reply radio wave R2 to calculate the running speed V of the conveyor belt 13. That is, the calculation device 8 calculates the running speed V of the conveyor belt 13 based on the time t at which the detector 7 receives the reply radio wave R2. Then, the operating state of the conveyor belt 13 is determined based on the change over time in the calculated running speed V. The running speed V is calculated as follows:

[0033] In this embodiment, the detectors 7 are arranged at a plurality of detection positions P spaced apart in the longitudinal direction L, so that while the conveyor belt 13 is running, each detector 7 wirelessly communicates with the IC tag 2 as the IC tag 2 passes nearby and acquires the identification information of the IC tag 2. The acquired identification information of the IC tag 2 is stored in the calculation device 8 together with the reception time t at which the detector 7 received the reply radio wave R2 from the IC tag 2. The separation distance PL in the longitudinal direction L between the detection positions P at which the detectors 7 are arranged is known in advance, so this separation distance PL is input to the calculation device 8.

[0034] Therefore, the calculation device 8 calculates the traveling speed V based on the reception time t of the reply radio wave R2 from the same IC tag 2 by each of the detectors 7 arranged at at least two detection positions P spaced apart in the longitudinal direction L, and the separation distance PL between the detection positions P. For example, if the separation distance between the detectors 7A and 7B is PL and the reception times t of the reply radio wave R2 from the same IC tag 2 by the detectors 7A and 7B are t1 and t2, respectively, the time required for the IC tag 2 to move from the detector 7A to the detector 7B is (t2 - t1), and therefore the traveling speed V is calculated as V = PL / (t2 - t1).

[0035] The calculation of the traveling speed V is not limited to using data from detectors 7 arranged at adjacent detection positions P in the longitudinal direction L (data from detectors 7A and 7B, data from detectors 7B and 7C, data from detectors 7C and 7A), but can also use data from detectors 7 arranged at two detection positions P selected from each detection position P. Therefore, data from detectors 7A and 7C may be used. Since the conveyor belt 13 is continuous, it is basically sufficient to calculate the traveling speed V in any one section (the separation distance PL between any two detection positions P). However, for example, the traveling speed V may differ slightly between the section immediately before the load of the transported item C and the section immediately after the load of the transported item C due to the weight of the transported item C or the impact of loading. Therefore, it is preferable to calculate the traveling speed V in multiple sections. This calculation method only requires that the separation distance PL is known, and does not require position information of the IC tag 2 on the conveyor belt 13, so it can be easily applied to any conveyor belt 13.

[0036] The traveling speed V can also be calculated by another method. In this calculation method, a single detector 7 placed at the same detection position P is used, and the installation pitch TL of each IC tag 2 to be used is input to the calculation device 8. Then, the single detector 7 placed at this detection position P receives reply radio waves R2 from each IC tag 2 placed at the installation pitch TL. The traveling speed V is calculated based on the installation pitch TL and the reception time t of the reply radio waves R2 from each IC tag 2 by this detector 7.

[0037] For example, if two IC tags 2 are installed at a predetermined installation pitch TL, and the reception times t of the reply radio waves R2 from each IC tag 2 by one detector 7 placed at the same detection position P are t1 and t2, respectively, the time required for the conveyor belt 13 to travel the length of the installation pitch TL is (t2 - t1), and therefore the running speed V is calculated as V = TL / (t2 - t1).

[0038] Furthermore, the traveling speed V can also be calculated by another method. In this calculation method, a single detector 7 arranged at the same detection position P sequentially receives reply radio waves R2 from the same IC tag for each revolution of the conveyor belt 13. The traveling speed V is calculated based on the reception time t of the reply radio waves R2 sequentially received by the detector 7 for each revolution of the conveyor belt 13 and the belt length BL of the conveyor belt 13.

[0039] For example, if the belt length is BL and the reception times of reply radio waves R2 from the same IC tag 2 sequentially received by the detector 7 located at the same detection position P for each revolution of the conveyor belt 13 are t1 and t2, the time required for one revolution of the conveyor belt 13 (movement of the belt length BL) is (t2 - t1), and therefore the running speed V is calculated as V = BL / (t2 - t1). This calculation method requires that the belt length BL of the conveyor belt 13 be known.

[0040] The running speed V calculated by the calculation device 8 reflects the actual operating status of the conveyor belt 13. In other words, when the running speed V is zero (including when it is close to zero), it can be determined that the conveyor belt 13 is not operating (not running). Although it is extremely rare, if the conveyor belt 13 stops while a certain IC tag 2 is located close to a certain detection position P (detector 7), that detector 7 will continue to receive the reply radio wave R2 from that IC tag 2 continuously. Therefore, if a detector 7 located at the same detection position P continues to receive the reply radio wave R2 from the same IC tag 2 continuously, it will also be determined that the conveyor belt 13 is not operating.

[0041] When the traveling speed V is approximately constant, it can be determined that the conveyor belt 13 is in steady operation. When the traveling speed V is steadily increasing, it can be determined that the conveyor belt 13 is in a starting state, and when the traveling speed V is steadily decreasing, it can be determined that the conveyor belt 13 is in a state of stopping operation.

[0042] Therefore, as shown in Fig. 10, the calculation device 8 outputs data DV of the change over time in the running speed V, and the accumulated operating time of the conveyor belt 13 is calculated based on the data DV. By referring to the data DV in Fig. 10, the actual operating status of the conveyor belt 13 (whether or not it is operating and changes in the running speed V) can be accurately grasped. The actual lifespan X of the conveyor belt 13 is more significantly influenced by the accumulated operating time than by the elapsed time since installation on the conveyor device 10. Therefore, using this data DV to grasp the actual operating time (accumulated operating time) of the conveyor belt 13 is advantageous for accurately grasping the actual lifespan X of the conveyor belt 13.

[0043] 1 is employed in this embodiment, the computing device 8 transmits the data DV via a communication network to terminal devices 9 (9a, 9b, 9c, 9d) located remotely from the installation site of the conveyor device 10. For example, the computing device 8 transmits the data DV and the calculated cumulative operating time to terminal devices 9 of related parties, such as the management office of the operating company (user) of the conveyor belt 13, the sales company of the conveyor belt 13, and the manufacturing company, which are located remotely from the installation site of the conveyor device 10. This allows these related parties to grasp the operating status of the conveyor belt 13 in substantially real time, even if they are located remotely from the location where the conveyor belt 13 is used.

[0044] The IC tag 2 and the detector 7 need to communicate frequently to prevent communication leaks between them. For example, by setting the communication frequency between the IC tag 2 and the detector 7 to between 3 and 10 times per second, the problem of the detector 7 not being able to receive the reply radio wave R2 from the IC tag 2 (communication leaks) can be avoided even when the traveling speed V is high. On the other hand, if this communication frequency is increased, when the IC tag 2 passes through the detection position P, the detector 7 located at that detection position P and the IC tag 2 perform wireless communication multiple times during that single passage. In other words, when the same IC tag 2 passes through each detection position P, the detector 7 located at that detection position P receives the reply radio wave R2 from the same IC tag 2 multiple times during that single passage.

[0045] As the conveyor belt 13 moves, the IC tag 2 moves toward the detection position P where the detector 7 is located, and as shown in data DR in Fig. 11 , the closer the IC tag 2 is to the detection position P and the detector 7 located at that detection position P communicates wirelessly, the higher the received signal strength RSSI of the reply radio wave R2 received by the detector 7 becomes. In other words, when the received signal strength RSSI of the reply radio wave R2 is the highest, the IC tag 2 is considered to be located closest to the detection position P.

[0046] Therefore, when the same IC tag 2 passes through the detection position P, if the detector 7 placed at the detection position P receives the reply radio wave R2 from the IC tag 2 multiple times during one passage, the time when the reply radio wave R2 with the highest received signal strength RSSI among the multiple received reply radio waves R2 is received is adopted as the reception time t by the detector 7 placed at the detection position P. Using the reception time t adopted in this way is advantageous for calculating the traveling speed V with higher accuracy.

[0047] In the above-described embodiment, the operating state of the conveyor belt 13 is determined using the return radio wave R2, but the temperature state of the conveyor belt 13 can also be determined using the return radio wave R2. In this case, correlation data R between the electrical resistance value of the IC tag 2 and the temperature of the IC tag 2 when the IC tag 2 is activated, as shown in FIG. 12, is determined in advance. More specifically, this correlation data R is data that indicates the relationship between the electrical resistance value of the electrical circuit of the IC tag 2 when the IC tag 2 is activated by receiving the transmitted radio wave R1 and the temperature of the IC tag 2. Generally, as the temperature of the IC tag 2 rises, the electrical resistance value of the electrical circuit of the IC tag 2 increases, so the correlation data R slopes upward to the right, as shown in FIG. 12.

[0048] This correlation data R is input to the calculation device 8. In addition, the calculation device 8 stores data on the embedded position of each IC tag 2 in the conveyor belt 13 (position data in the longitudinal direction L and width direction W), a reference temperature (threshold value) for determining that the conveyor belt 13 is abnormally overheated, and the like.

[0049] 2, while the conveyor belt 13 is running, each detector 7 transmits an outgoing radio wave R1 toward the IC tag 2. When each IC tag 2 approaches its corresponding detector 7, the antenna portion 3b receives the outgoing radio wave R1, and this outgoing radio wave R1 generates power in the IC tag 2, activating the IC tag 2. Data on the electrical resistance value in the electrical circuit of the IC tag 2 when the IC tag 2 is activated is stored in the memory portion of the IC chip 3a.

[0050] Then, in response to the transmitted radio waves R1, the IC tag 2 sequentially returns reply radio waves R2 to the detector 7. The above-mentioned electrical resistance value data stored in the IC tag 2 and the identification information of the IC tag 2 are transmitted from the IC tag 2 to the detector 7 together with the reply radio waves R2.

[0051] The data acquired by the detector 7 is input to the calculation device 8. The calculation device 8 calculates the temperature of the position where each IC tag 2 is embedded in the conveyor belt 13 based on the input data of the electrical resistance value of each IC tag 2 and the correlation data R. That is, the calculation device 8 applies the data of the electrical resistance value input from the detector 7 to the correlation data R exemplified in Fig. 12 to calculate the temperature of that IC tag 2. The calculated temperature of the IC tag 2 can be regarded as the temperature of the position where that IC tag 2 is embedded in the conveyor belt 13.

[0052] If the detectors 7 are arranged at a plurality of detection positions spaced apart in the longitudinal direction L of the conveyor belt 13 between the pulleys 11a and 11b and the IC tags 2 are embedded at a plurality of locations spaced apart in the longitudinal direction L of the conveyor belt 13, it is possible to grasp the temperature distribution in the longitudinal direction L of the running conveyor belt 13. Furthermore, if the IC tags 2 are embedded at a plurality of locations spaced apart in the width direction W of the conveyor belt 13, it is possible to grasp the temperature distribution in the width direction W of the running conveyor belt 13.

[0053] When the support rollers 12 of the conveyor device 10 are rotating normally and the conveyor belt 13 is running steadily, the temperature of the conveyor belt 13 at each detection position spaced apart in the longitudinal direction L is approximately constant, as shown by the temperature data Dn illustrated by the dashed line in Figure 13. On the other hand, if any of the support rollers 12 on the carrier side of the conveyor device 10 is not rotating properly, the frictional resistance between the poorly rotating support roller 12 and the running conveyor belt 13 increases, causing the conveyor belt 13 to heat up abnormally. Alternatively, if the conveyor belt 13 runs while in contact with the frame of the conveyor device 10, the conveyor belt 13 will heat up abnormally.

[0054] When abnormal heating occurs in the conveyor belt 13 in this way, the temperature rises locally as shown by the temperature data Dx illustrated by the solid line in Fig. 13. The temperature of the conveyor belt 13 on the vertical axis in Fig. 13 is the temperature calculated by the computing device 8 as described above. As illustrated in Fig. 13, the temperature of the conveyor belt 13 at the detection position near the support roller 12 that is not rotating properly and at the detection position near the contact position between the frame and the conveyor belt 13 is higher than the temperature of the conveyor belt 13 at other detection positions.

[0055] 13, it is possible to roughly identify the position in the longitudinal direction L of the conveyor device 10 where abnormal heating of the conveyor belt 13 is occurring. That is, it can be estimated that the rotation of the support rollers 12 is poor or the conveyor belt 13 is coming into contact with the frame in the vicinity of the detection position where the temperature data Dx reaches its peak (maximum value).

[0056] As described above, in this management system 1, two types of passive IC tags 2, which have different communication methods, a radio wave IC tag 2A and an electromagnetic coupling IC tag 2B, are used as the passive IC tags 2 installed on the conveyor belt 13. There are differences in the communication characteristics when one IC tag 2A communicates wirelessly with the detector 7 and the communication characteristics when the other IC tag 2B communicates wirelessly with the detector 7. For example, depending on the influence of temperature, humidity, external force (impact force), type (physical properties) of the transported object C, even if the wireless communication between one IC tag 2A and the detector 7 is easily interrupted, the wireless communication between the other IC tag 2B and the detector 7 may not be interrupted, or vice versa.

[0057] Therefore, even in various wireless communication environments, the detector 7 can receive the reply radio wave R2 from the IC tag 2 using at least one of the two communication methods of the IC tags 2A, 2B. In other words, in various wireless communication environments that arise due to differences in the usage conditions of the conveyor belt 13, there is a low risk that wireless communication will be disabled both between the radio wave method IC tag 2A and the detector 7 and between the electromagnetic coupling method IC tag 2B and the detector 7. Therefore, since the detector 7 can easily and reliably receive the reply radio wave R2, it is advantageous to use the reply radio wave R2 to more reliably grasp the state of the conveyor belt 13 under various usage conditions.

[0058] As shown in Figures 14 and 15, IC tags 2A and 2B using each communication method can be installed in various patterns on the conveyor belt 13. In Figures 14 and 15, the IC tags 2B using the electromagnetic coupling method are shaded to make it easier to distinguish between the IC tags 2A and 2B. In Figure 14(A), IC tags 2A and 2B using different communication methods are alternately arranged in the longitudinal and width directions. In Figure 14(B), IC tags 2A and 2B using the same communication method are arranged in a line in the width direction, and this line is alternately arranged in the longitudinal direction. In Figure 14(C), IC tags 2A and 2B using the same communication method are arranged in a line in the longitudinal direction, and this line is alternately arranged in the width direction. In Figure 14(D), both IC tags 2A and 2B using different communication methods are randomly arranged in each line in the width direction.

[0059] 15(A) and 15(B), a certain range in the longitudinal direction (in this embodiment, the range of arrangement of three IC tags 2 in the longitudinal direction) is defined as one unit, and units with different arrangement patterns are arranged alternately in the longitudinal direction. In Fig. 15(A), one unit in which only IC tags 2A of one communication method are arranged and one unit in which only IC tags 2B of the other communication method are arranged are arranged alternately in the longitudinal direction. In Fig. 15(B), one unit in which IC tags 2A and 2B of each communication method are arranged and the proportion of IC tags 2A of one communication method is high, and one unit in which IC tags 2A and 2B of each communication method are arranged and the proportion of IC tags 2B of the other communication method is high are arranged alternately in the longitudinal direction.

[0060] As shown in Figures 14 and 15, there are many possible arrangement patterns for the IC tags 2A and 2B, but the installation space for the detector 7 may be limited depending on the conveyor device 10. For example, in the case of a conveyor device 10 in which the detector 7 can be installed only in an area corresponding to one widthwise end of the conveyor belt 13, an arrangement pattern in which IC tags 2A and 2B of different communication methods are mixed is adopted at one widthwise end of the conveyor belt 13. In other words, an arrangement pattern in which only IC tags 2A and 2B of the same communication method are arranged at one widthwise end of the conveyor belt 13 is not adopted. In this way, an arrangement pattern that easily ensures stable wireless communication between the IC tags 2A and 2B of both communication methods and the communicator 7 is determined, taking into consideration the installation location of the detector 7 in the conveyor device 10, the matters to be monitored (such as the operating status, wear state, temperature state, and presence or absence of vertical tears of the conveyor belt 13) and the characteristics of the transported goods C.

[0061] In each embodiment of the management system 1 described later, two types of IC tags 2A and 2B with different communication methods are employed as the IC tags 2. In addition, in each embodiment of the management system 1 described later, the various arrangements and specifications described above can be employed.

[0062] Another embodiment of the management system 1 illustrated in Figures 16 to 18 monitors the surface wear state as the state of the conveyor belt 13. In Figure 18, the steel cords 15 are partially omitted. In this embodiment, the sensor unit 6 is embedded in the upper cover rubber 16 to monitor the surface wear state of the upper cover rubber 16, but when monitoring the surface wear state of the lower cover rubber 17, the sensor unit 6 is embedded in the lower cover rubber 17.

[0063] This management system 1, like the previous embodiment, includes an IC tag 2, a detector 7, and a computing device 8. However, it differs from the previous embodiment in that a linear sensor unit 6 is connected to the IC tag 2, as shown in Figures 19 and 20. The IC tag 2 (2A, 2b) is the same as in the previous embodiment, and the entire IC tag 2 is covered with an insulating layer 5.

[0064] The sensor unit 6 extends over a desired range of the conveyor belt 13 outside the connected IC tag 2 to form a loop circuit. The embedding depth (initial embedding depth) of the sensor unit 6 (loop circuit) from the surface of the conveyor belt 13 is preset. In this embodiment, the sensor unit 6 is embedded in the upper cover rubber 16, so the embedding depth (initial embedding depth) from the surface of the upper cover rubber 16 is preset. Since there is an allowable depth for wear of the upper cover rubber 16 (wear limit depth), the embedding depth of the sensor unit 6 is set to, for example, this wear limit depth. When the sensor unit 6 is embedded in the lower cover rubber 17, the embedding depth (initial embedding depth) from the surface of the lower cover rubber 17 is preset.

[0065] The sensor unit 6 is a conductive linear body formed of known materials such as conductive rubber, conductive paste, or metal wire. The outer diameter (width) of the sensor unit 6 is, for example, approximately 0.5 mm to 2.0 mm. The sensor unit 6 may be a simple wire with a circular cross section, or may be a flattened linear body (strip-shaped wire). The sensor unit 6 is covered with an insulating layer 5 and is electrically insulated from the outside.

[0066] One end and the other end in the longitudinal direction of the sensor unit 6 are each electrically connected to the IC chip 3a. The IC tag 2 is provided with a large number of pairs of terminals connected to the IC chip 3a. One end and the other end in the longitudinal direction of the sensor unit 6 are each connected to these pairs of terminals, thereby electrically connecting to the IC chip 3a. The sensor unit 6 and the pair of terminals are connected using grommets and crimp terminals, or by conductive adhesive, welding, solder, or the like. In this embodiment, five pairs of terminals are provided, but the number of pairs of terminals provided on the IC tag 2 is not particularly limited and may be one. Due to space constraints, the number of pairs of terminals provided on one IC tag 2 is, for example, between one and six.

[0067] The sensor unit 6 extends to a position corresponding to the range where the wear state is desired to be grasped in a plan view, and the IC tag 2 is preferably embedded in the widthwise end of the conveyor belt 13. In this embodiment, the IC tag 2 is embedded in one widthwise end of the conveyor belt 13, and the sensor unit 6 extends from one widthwise end of the traction layer 14 to the other widthwise end.

[0068] The surface wear state of the conveyor belt 13 in the longitudinal direction L is generally the same over the entire length of the conveyor belt 13. The IC tags 2 connected to the sensor units 6 are embedded in a plurality of locations in the longitudinal direction L of the conveyor belt 13 at intervals.

[0069] Since the wear state of the surface of the conveyor belt 13 varies greatly in the width direction W, it is preferable that the sensor unit 6 extend to cover the entire width of the traction layer 14. Alternatively, since the central portion of the upper cover rubber 16 in the width direction W is most susceptible to wear, the sensor unit 6 can also extend to cover at least this central portion in the width direction W.

[0070] The computing device 8 stores the embedded depth (initial embedded depth) of the sensor unit 6 from the surface of the upper cover rubber 16, linked to sensor identification information that identifies the sensor unit 6. If the sensor unit 6 is embedded in the lower cover rubber 17, the embedded depth (initial embedded depth) from the surface of the lower cover rubber 17 is linked to the sensor identification information of the sensor unit 6 and stored in the computing device 8. Furthermore, the computing device 8 stores embedded position information of each IC tag 2 on the conveyor belt 13 (at least position data in the longitudinal direction L) linked to the identification information of each IC tag 2. Position information (position data in the longitudinal direction L and width direction W) of each sensor unit 6 with respect to the connected IC tag 2 can also be stored in the computing device 8 linked to the sensor identification information.

[0071] Next, an example of the procedure for determining the wear state of the conveyor belt 13 using this management system 1 will be described.

[0072] 16 to 18, while the conveyor belt 13 is running, the detector 7 transmits an outgoing radio wave R1 from the transmitter 7s toward the IC tag 2 passing in front of (in front of) the detector 7. When the IC tag 2 receives the outgoing radio wave R1, it transmits a reply radio wave R2 to the receiver 7r in response to the outgoing radio wave R1.

[0073] If the sensor unit 6 is healthy, electricity is input to the IC chip 3a by the transmitted radio wave R1 received by the antenna unit 3b, activating the IC chip 3a. When the IC chip 3a is activated, electricity flows from one end of the sensor unit 6 to the other end and is input to the IC chip 3a. This allows the IC chip 3a to determine that the sensor unit 6 (loop circuit) is energized. The IC chip 3a then retrieves the identification information of the IC tag 2 stored in the IC chip 3a and the sensor identification information of the connected sensor unit 6. When the antenna unit 3b transmits a reply radio wave R2, the retrieved identification information of the IC tag 2 and the sensor identification information are transmitted by the reply radio wave R2 and received by the receiver 7r.

[0074] By receiving this return radio wave R2, the receiver 7r acquires the data (the identification information of the IC tag 2 and the sensor identification information) from the IC chip 3a transmitted by the return radio wave R2. The data (the identification information of the IC tag 2 and the sensor identification information) acquired by the detector 7 is input to the calculation device 8. The calculation device 8 uses the input identification information of each IC tag 2 to identify the buried position information on the conveyor belt 13 of the IC tag 2 linked to the identification information, which has been stored in advance. Furthermore, the input sensor identification information of the sensor unit 6 is used to identify the buried depth of the sensor unit 6 linked to the sensor identification information, which has been stored in advance.

[0075] When sensor identification information is input from detector 7 to arithmetic unit 8, arithmetic unit 8 determines that the sensor unit 6 of that sensor identification information is sound and that this sensor unit 6 (loop circuit) is energized. Then, because the buried depth of that sensor unit 6 is known, arithmetic unit 8 determines that wear has not progressed to the buried depth of that sensor unit 6 within the buried range of that sensor unit 6. Furthermore, because information on the buried position on conveyor belt 13 of the IC tag 2 to which this sensor unit 6 is connected is specified, it can be determined that the range in which wear has not progressed to the buried depth of that sensor unit 6 is generally near the buried position of that IC tag 2.

[0076] If the upper cover rubber 16 wears down to the buried depth of the sensor unit 6, the sensor unit 6 will be exposed to the surface and will soon break. If the sensor unit 6 breaks, even if the IC chip 3a is activated by the transmitted radio wave R1 received by the antenna unit 3b, electricity will not flow through the sensor unit 6, and the IC chip 3a will know that the sensor unit 6 is not energized. Therefore, even if the tag identification information of the IC tag 2 stored in the IC chip 3a is retrieved, the sensor identification information of the connected sensor unit 6 is not retrieved. Then, when the antenna unit 3b transmits the return radio wave R2, the retrieved identification information of the IC tag 2 is transmitted by the return radio wave R2 and received by the receiver 7r, but the sensor identification information of the connected sensor unit 6 is not received by the receiver 7r.

[0077] That is, the data acquired by the detector 7 (the identification information of the IC tag 2) is input to the calculation device 8, and the calculation device 8 uses the input identification information of each IC tag 2 to identify the buried position information on the conveyor belt 13 of the IC tag 2 linked to that identification information, which has been stored in advance. However, since there is no sensor identification information for the sensor unit 6 connected to that IC tag 2, that sensor unit 6 is determined to be damaged. That is, in this case, the calculation device 8 determines that wear has progressed to the buried depth of the sensor unit 6 within the range in which that sensor unit 6 is buried.

[0078] Since the embedded position information in the conveyor belt 13 of the IC tag 2 for which the sensor identification information of the connected sensor unit 6 cannot be obtained is specified, it is possible to confirm that the upper cover rubber 16 has actually worn down to the wear limit depth near the embedded position of the IC tag 2. In this way, the wear state of the conveyor belt 13 is grasped based on the detection data by the sensor unit 6 (data on whether the sensor unit 6 is energized or not).

[0079] If the sensor unit 6 is made of a thin wire material with a simple circular cross section, when a sharp object C is fed onto the conveyor bell 13, the sensor unit 6 may be cut by the sharp part of the object C. In this case, even if the wear has not progressed to the buried depth of the sensor unit 6, the sensor unit 6 is broken, and the calculation device 8 will determine that the wear has progressed to the buried depth, resulting in a false detection.

[0080] Therefore, it is preferable to use a flattened linear body (strip-shaped wire) as the sensor unit 6. Using a strip-shaped sensor unit 6 in a plan view is advantageous in avoiding the above-mentioned false detection. The width of the flattened sensor unit 6 is, for example, about 5 mm to 10 mm.

[0081] An IC tag 2 with a sensor unit 6 as shown in FIG. 21 can also be used. This IC tag 2 has a plurality (five) of sensor units 6a to 6e connected to it. The outer circumferential surface of each of the sensor units 6a to 6e is covered with an insulating layer 5. Each of the sensor units 6a to 6e forms an independent loop circuit. Therefore, a plurality (five) of independent sensor units 6 (loop circuits) are connected to one IC tag 2.

[0082] 22, the IC tag 2 has independent sensor units 6a to 6e embedded at intervals in the thickness direction (depth direction) of the conveyor belt 13. The embedded intervals in the thickness direction (depth direction) of the independent sensor units 6a to 6e are preferably equal to each other, for example, in the range of 0.5 mm to 2 mm. The embedded depth of the sensor unit 6e, which is embedded at the deepest position, is preferably set to the wear limit depth.

[0083] When this IC tag 2 is used, the sensors 6a, 6b, 6c, 6d, and 6e are damaged and stop conducting electricity one after another as the wear of the upper cover rubber 16 progresses. Therefore, by using this IC tag 2, the progress of wear of the upper cover rubber 16 can be grasped in more detail.

[0084] 16 to 18 can also determine whether or not a crack extending in the longitudinal direction L of the conveyor belt 13 (so-called vertical crack) has occurred as a condition of the conveyor belt 13. That is, if a vertical crack occurs in the conveyor belt 13 and the sensor unit 6 breaks, the identification information of the IC tag 2 is transmitted by the return radio wave R2 and received by the receiver 7r, just as in the case where the upper cover rubber 16 wears out and the sensor unit 6 breaks as described above, but the sensor identification information of the sensor unit 6 connected to the IC tag 2 is not received by the receiver 7r. Therefore, whether or not a vertical crack has occurred can be determined based on whether or not the detector 7 has acquired the sensor identification information.

[0085] A method for determining whether or not a longitudinal tear has occurred in the conveyor belt 13 will be described in detail based on another embodiment of the management system 1 illustrated in FIGS. 23 and 24.

[0086] 24, a large number of IC tags 2 connected to sensor units 6 are embedded in the conveyor belt 13 at intervals P (embedding pitch P) in the longitudinal direction L. In this embodiment, each IC tag 2 is embedded at one widthwise end of the conveyor belt 13, and the sensor unit 6 (loop circuit) extends from one widthwise end to the other widthwise end of the traction layer 14. The IC tags 2 can also be embedded in a dispersed manner (for example, in a staggered arrangement) at one widthwise end and the other widthwise end.

[0087] In this embodiment, the detector 7 is disposed on the return side of the conveyor device 10, but it can also be disposed on the carrier side. The computing device 8 stores information on the embedded position of each IC tag 2 on the conveyor belt 13 (at least position data in the longitudinal direction L) linked to the identification information of each IC tag 2. Furthermore, the computing device 8 stores information on the extension position of each sensor unit 6 relative to the IC tag 2 (at least position data in the longitudinal direction L) linked to sensor identification information that identifies each sensor unit 6.

[0088] To determine whether a vertical tear has occurred, the detector 7 transmits an outgoing radio wave R1 from the transmitter 7s toward the IC tag 2 passing in front of (in front of) the detector 7 while the conveyor belt 13 is running. When the IC tag 2 receives the outgoing radio wave R1, it transmits a reply radio wave R2 to the receiver 7r in response to the outgoing radio wave R1. The reply radio wave R2 is received by the receiver 7r and input to the calculation device 8.

[0089] If the sensor unit 6 (loop circuit) is healthy, the identification information of the IC tag 2 and the sensor identification information of the sensor unit 6 are transmitted by return radio waves R2 from the antenna unit 3b of each IC tag 2 and received by the receiver 7r. Based on the input identification information of the IC tag 2 and the sensor identification information of the sensor unit 6, the computing device 8 determines that the sensor unit 6 (loop circuit) is energized and that no vertical tear has occurred in the conveyor belt 13 within the embedded range of the sensor unit 6.

[0090] If a vertical tear occurs in the conveyor belt 13 and the sensor unit 6 (loop circuit) breaks, electricity will not flow through the sensor unit 6 even if the IC tag 2 is activated by the transmitted radio waves R1 received by the antenna unit 3b of the IC tag 2 to which the sensor unit 6 is connected. Therefore, the IC chip 3a of the IC tag 2 determines that the sensor unit 6 is not energized. Therefore, even if the identification information of the IC tag 2 stored in the IC chip 3a is retrieved, the sensor identification information of the sensor unit 6 is not retrieved. When the antenna unit 3b transmits the return radio waves R2, the retrieved identification information of the IC tag 2 is transmitted by the return radio waves R2 and received by the receiver 7r, but the sensor identification information of the sensor unit 6 is not received by the receiver 7r. Since the sensor identification information of the sensor unit 6 connected to the IC tag 2 is not input to the computing device 8, the computing device 8 determines that the sensor unit 6 is damaged.

[0091] If the IC tag 2 is damaged due to a vertical tear or the like, even if the transmitter 7s transmits radio waves R1 to the IC tag 2, the receiver 7r will not receive the identification information of the IC tag 2 or the sensor identification information of the sensor unit 6 connected to the IC tag 2. In this case, the calculation device 8 determines that an abnormality has occurred in the conveyor belt 13.

[0092] The IC tag 2 with the sensor unit 6 shown in Fig. 21 can also be installed on a conveyor belt 13 as shown in Fig. 25. In this IC tag 2, the independent sensor units 6a to 6e are embedded at intervals in the longitudinal direction L of the conveyor belt 13. Note that Fig. 25 omits a portion of the steel cord 15. The embedded intervals of the independent sensor units 6a to 6e in the longitudinal direction L should preferably be equal to each other, for example, in the range of 1 m to 3 m.

[0093] As described above, by using the management system 1 in which the IC tag 2 connected to the sensor unit 6 is installed on the conveyor belt 13, the calculation device 8 can grasp at least one of the three items of the temperature state, wear state, and occurrence state of vertical tears of the conveyor belt 13 based on the data detected by the sensor unit 6. The sensor unit 6 is not limited to the form exemplified in the embodiment, and for example, a known sensor having the same function as the sensor unit 6 can also be used.

[0094] REFERENCE SIGNS LIST 1 Management system 2 IC tag 2A Radio wave type IC tag 2B Electromagnetic coupling type IC tag 3a IC chip 3b Antenna section 4 Substrate 5 Insulating layer 6 (6a, 6b, 6c, 6d, 6e) Sensor section 7 (7A, 7B, 7C) Detector 7s Transmitting section 7r Receiving section 8 Calculating device 9 (9a, 9b, 9c, 9d) Terminal device 10 Conveyor device 11a, 11b Pulley 12 Support roller 13 Conveyor belt 14 Core layer 15 Steel cord 16 Upper cover rubber 17 Lower cover rubber C Conveyed object

Claims

1. A conveyor belt management system comprising a passive IC tag attached to a conveyor belt, a detector which wirelessly communicates with said IC tag, and a computing device communicatively connected to said detector, wherein said detector transmits radio waves toward said IC tag attached to said conveyor belt which is attached to a conveyor device, and receives reply radio waves from said IC tag in response to said transmitted radio waves, and said computing device grasps the condition of said conveyor belt using said reply radio waves. In this conveyor belt management system, two types of IC tags are used: a radio wave type IC tag and an electromagnetic coupling type IC tag.

2. A conveyor belt management system as described in claim 1, wherein the calculation device calculates the running speed of the conveyor belt based on the time of reception of the return radio wave by the detector arranged at at least one detection position of the conveyor device, and the operating status of the conveyor belt is determined based on the change over time in this calculated running speed.

3. A conveyor belt management system as described in claim 1 or 2, comprising a plurality of sensor units installed on the conveyor belt, including a sensor unit electrically connected to the radio wave type IC tag and a sensor unit electrically connected to the electromagnetic coupling type IC tag, wherein detection data by each of the sensor units is transmitted from the IC tag to the detector by the return radio waves and input to the arithmetic device, and the condition of the conveyor belt is grasped by the arithmetic device based on the input detection data.

4. A conveyor belt management system as described in claim 3, wherein at least one of the three items of temperature state, wear state, and occurrence state of longitudinal tears of the conveyor belt is grasped by the computing device based on the detection data.

5. A method for managing a conveyor belt, comprising the steps of: installing a passive IC tag on a conveyor belt; transmitting radio waves from a detector that wirelessly communicates with the IC tag toward the IC tag installed on the conveyor belt attached to a conveyor device; receiving a reply radio wave from the IC tag in response to the transmitted radio wave by the detector; and using the reply radio wave to determine the condition of the conveyor belt by a computing device, said method for managing a conveyor belt comprising the steps of: installing a passive IC tag on a conveyor belt; 6. The method for managing a conveyor belt according to claim 5, wherein the IC tag is embedded in the conveyor belt when the conveyor belt is manufactured.

7. The method for managing a conveyor belt according to claim 5, wherein the IC tag is attached to the conveyor belt after the conveyor belt is manufactured.

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