Conveyor belt wear detection device and method

Abstract

To provide a wear detection device and method which make it possible to efficiently grasp the degree of wear on the surface of a conveyor belt, while having high versatility and achieving low cost.SOLUTION: Embedded bodies 2 which are embedded at intervals in a longitudinal direction in a conveyor belt 17 each include: a passive-type IC tag 3 arranged at one end portion in the width direction of the conveyor belt 17; and a linear detection element 7 which is connected to the IC tag 3 and extends from the one end portion toward the other end portion in the width direction of the conveyor belt 17 to form a loop circuit 9. The embedding depth from the surface of the conveyor belt 17 of the loop circuit 9 is set in advance. A transmission electric wave W1 is transmitted from a detector 10 toward the IC tag 3. Information from the IC tag 3 is sent to the detector 10 by a response electric wave W2 transmitted from the IC tag 3 in response to the transmission electric wave W1. It is determined by an arithmetic section 13 whether or not the loop circuit 9 is energized, by using the information. On the basis of the result of the determination, the degree of wear on the surface of the conveyor belt 17 in a range where the loop circuit 9 is embedded is grasped.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a wear detection device and method for a conveyor belt, and more particularly, to a wear detection device and method that have high versatility, low cost, and can efficiently grasp the wear condition of the surface of the conveyor belt.

Background Art

[0002] The conveyor belt that is looped around a conveyor device and runs conveys various conveyed objects to the conveyance destination. Since various conveyed objects are loaded onto the conveyor belt, the surface of the conveyor belt wears over time due to these conveyed objects and the like. When this wear reaches, for example, the core layer, the risk of damage to the core layer increases. Therefore, when the wear reaches the wear limit depth, it is necessary to replace the conveyor belt.

[0003] Conventionally, to detect the wear on the surface of a conveyor belt, for example, the conveyor belt is stopped, and an ultrasonic thickness gauge is used to grasp the wear condition at a predetermined location in this state. This method involves a lot of manual work and is carried out with the conveyor belt stopped, so it is difficult to efficiently grasp the wear condition.

[0004] As another method, it has been proposed to embed an IC tag with a temperature sensor in the conveyor belt and grasp the surface wear state based on the detected temperature (the internal temperature of the conveyor belt) by this temperature sensor (see Patent Document 1). However, an IC tag with a temperature sensor needs to be specially manufactured, so it requires a corresponding cost. Also, since the internal temperature of the conveyor belt is used, it may be necessary to consider correcting errors due to the external environment. Therefore, there is room for improvement in efficiently grasping the wear condition of the surface of the conveyor belt while having high versatility and low cost.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] The object of the present invention is to provide a wear detection device and method that can efficiently determine the degree of wear on the surface of a conveyor belt while being highly versatile and low-cost. [Means for solving the problem]

[0007] To achieve the above objective, the conveyor belt wear detection device of the present invention is The upper cover rubber into which the conveyed material is fed, the lower cover rubber, and the core layer positioned between the upper and lower cover rubbers are integrated into a single structure. A conveyor belt wear detection device comprising an embedded body embedded in the conveyor belt, a detector that wirelessly communicates with the embedded body without contact with the conveyor belt, and a calculation unit connected to the detector, wherein the embedded body has a passive IC tag and a linear detection element connected to the IC tag and extending outside the IC tag to form a loop circuit, and the embedding depth of the loop circuit from the surface of the conveyor belt is predetermined. The IC tag is embedded in one end of the conveyor belt in the width direction, and the loop circuit extends to the other end of the core layer in the width direction. The detector transmits a radio wave towards the IC tag, and the IC tag transmits a reply radio wave in response to this radio wave. The information from the IC tag is then transmitted to the detector, and the calculation unit uses this information to determine whether the loop circuit is energized or not. Based on this determination, the degree of wear on the surface of the conveyor belt in the area where the loop circuit is embedded is determined.

[0008] The present invention provides a method for detecting wear on a conveyor belt. The upper cover rubber into which the conveyed material is fed, the lower cover rubber, and the core layer positioned between the upper and lower cover rubbers are integrated into a single structure. A method for detecting wear on a conveyor belt, using an embedded body embedded in the conveyor belt, a detector that wirelessly communicates with the embedded body without contact with the conveyor belt, and a calculation unit connected to the detector, The buried object comprises a passive IC tag and a linear detection element connected to the IC tag and extending outside the IC tag to form a loop circuit, and the burial depth of the loop circuit from the surface of the conveyor belt is set in advance. The IC tag is embedded in one end of the conveyor belt in the width direction, and the loop circuit is extended to the other end of the core layer in the width direction. The detector transmits a radio wave towards the IC tag, and the calculation unit uses the information from the IC tag transmitted to the detector by the reply radio wave transmitted from the IC tag in response to the transmitted radio wave to determine whether or not the loop circuit is energized, and based on this determination, the degree of wear of the conveyor belt in the area where the loop circuit is embedded is determined. [Effects of the Invention]

[0009] According to the present invention, the buried object has a simple configuration comprising a passive IC tag and a linear detection element connected to the IC tag and extending outside the IC tag to form a loop circuit. Therefore, the buried object can be constructed from general-purpose components, which is advantageous in reducing costs. Furthermore, the detector only needs to be capable of wireless communication with the buried object, so it can also be constructed from general-purpose components, which is advantageous in reducing costs.

[0010] When the surface of the conveyor belt wears down to the depth to which the loop circuit is embedded, the loop circuit is exposed to the surface and breaks. The IC tag to which the detection element forming the loop circuit is connected can then determine whether or not the loop circuit is energized. Therefore, by using the information from the IC tag transmitted to the detector by the reply radio wave, the calculation unit can accurately determine whether or not the loop circuit is energized. Since the depth to which the loop circuit is embedded from the surface of the conveyor belt is predetermined, it can be determined whether or not wear has progressed to the depth to which the loop circuit is embedded based on this determination. Therefore, it becomes possible to efficiently determine the degree of wear on the surface of the conveyor belt while the conveyor belt is running, without performing complicated work. [Brief explanation of the drawing]

[0011] [Figure 1] This is an explanatory diagram illustrating an embodiment of a conveyor belt wear detection device installed in a conveyor system, shown in a side view of the conveyor belt. [Figure 2]It is a sectional view taken along the line A-A of FIG. 1. [Figure 3] It is an explanatory view exemplifying an enlarged cross-sectional view of the conveyor belt of FIG. 1. [Figure 4] It is an explanatory view exemplifying a plan view of the conveyor belt of FIG. 3. [Figure 5] It is an explanatory view exemplifying a plan view of the embedded body of FIG. 4. [Figure 6] It is an explanatory view exemplifying a front view of the embedded body of FIG. 4. [Figure 7] It is an explanatory view exemplifying a plan view of a modified example of the embedded body. [Figure 8] It is an explanatory view exemplifying an enlarged cross-sectional view of a part of the conveyor belt in which the embedded body of FIG. 7 is embedded.

Mode for Carrying Out the Invention

[0012] Hereinafter, a wear detection device and method for a conveyor belt of the present invention will be described based on the embodiments shown in the drawings.

[0013] An embodiment of a wear detection device 1 (hereinafter referred to as the detection device 1) for a conveyor belt illustrated in FIGS. 1 to 4 is installed in a conveyor device 15 and detects the wear condition (wear depth) of the surface of the conveyor belt 17. The arrow L in the figure indicates the longitudinal direction of the conveyor belt 17, and the arrow W indicates the width direction of the conveyor belt 17. In FIG. 4, the steel cord 19 is described with partial omission. In this embodiment, the detection element 7 (loop circuit 9) is embedded in the upper cover rubber 20 to grasp the wear condition of the surface of the upper cover rubber 20, but when grasping the wear condition of the surface of the lower cover rubber 21, the detection element 7 (loop circuit 9) is embedded in the lower cover rubber 21.

[0014] The conveyor device 15 includes a pair of pulleys 15a and 15b and a conveyor belt 17 stretched between the pulleys 15a and 15b. The conveyor belt 17 is supported by a large number of support rollers 16 between the pulleys 15a and 15b.

[0015] The conveyor belt 17 is integrally formed by integrating an upper cover rubber 20, a lower cover rubber 21, and a core layer 18 disposed between the two. The core layer 18 is formed by arranging a number of steel cords 19 extending in the longitudinal direction L in parallel in the width direction W, and these steel cords 19 are joined via a coat rubber (adhesive rubber). The core layer 18 is not limited to the steel cords 19 and may be a fiber layer composed of canvas or the like. The conveyor belt 17 is provided with other members as required.

[0016] On the carrier side (upper side in FIGS. 1 and 2) of the conveyor device 15, 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 in which the central portion in the width direction W protrudes downward. The conveyed object C is put on the upper surface of the upper cover rubber 20 and conveyed. On the return side (lower side in FIGS. 1 and 2) of the conveyor device 15, the upper cover rubber 20 of the conveyor belt 17 is supported in a flat state by the support roller 16.

[0017] The detection device 1 includes an embedded body 2 embedded in the conveyor belt 17, a detector 10, and an arithmetic unit 13. In this embodiment, a warning device 14 is further provided. The warning device 14 can be provided optionally. The embedded body 2 has a passive type IC tag 3 and a linear detection element 7 connected to the IC tag 3. The detector 10 has a transmitter 11 and a receiver 12.

[0018] As illustrated in FIGS. 5 and 6, the IC tag 3 has an IC chip 4 and an antenna portion 5 connected to the IC chip 4. The IC chip 4 and the antenna portion 5 are disposed on a substrate 6. The IC chip 4 and the antenna portion 5 are covered by an insulating layer 6a, and the entire IC tag 3 is electrically insulated from the outside. However, the IC tag 3 and the detection element 7 are electrically connected so as to be energizable. The insulating layer 6a is formed of a known insulating material such as insulating rubber, resin such as polyester, or natural fiber.

[0019] The IC chip 4 stores tag-specific information such as the identification number of the IC tag 3, element identification information that identifies the detection element 7 connected to the IC tag 3, and other necessary information as needed. Various known types of antennas can be used for the antenna section 5, but in this embodiment, a dipole antenna extending symmetrically from the IC chip 4 is employed. This antenna section 5 is appropriately folded to maximize its extension length within a limited space.

[0020] The IC tag 3 uses a commonly available specification, and for example, an RFID tag can be used. The area of ​​the IC tag 3 is, for example, 2 cm². 2 More than 70cm 2 More preferably, 3cm 2 More than 34cm 2 Further preferably 3 cm 2 More than 27cm 2 The thickness is preferably 0.5 mm or less, for example, 0.01 mm to 0.4 mm, and more preferably 0.03 mm to 0.15 mm. In this way, the size of the IC tag 3 is made as small as possible, and the heat resistance temperature is specified to be around 200°C.

[0021] The detection element 7 extends outside the connected IC tag 3 to a desired range on the conveyor belt 17, forming a loop circuit 9. The depth to which the loop circuit 9 is embedded from the surface of the conveyor belt 17 (initial embedding depth) is preset. In this embodiment, since the loop circuit 9 is embedded in the upper cover rubber 20, the depth to which it is embedded from the surface of the upper cover rubber 20 (initial embedding depth) is preset. Since there is a depth to which the upper cover rubber 20 can withstand wear (wear limit depth), the embedding depth of the loop circuit 9 is set to, for example, this wear limit depth. If the loop circuit 9 is embedded in the lower cover rubber 21, the depth to which it is embedded from the surface of the lower cover rubber 21 (initial embedding depth) is preset.

[0022] The detection element 7 is a conductive linear body, formed from a known material such as conductive rubber, conductive paste, or metal wire. The outer diameter (width) of the detection element 7 is, for example, about 0.5 mm to 2.0 mm. The detection element 7 may be a simple wire with a circular cross-section, but it can also be a flattened linear body (a strip-shaped wire).

[0023] The detection element 7 is electrically insulated from the outside by having its outer surface covered with an insulator 8. The insulator 8 is formed from a known insulating material, similar to the insulating layer 6a.

[0024] The detection element 7 has two longitudinal ends, one and the other, that are electrically connected to the IC chip 4. The IC tag 3 (substrate 6) is provided with a number of pairs of terminals connected to the IC chip 4. The detection element 7 is electrically connected to the IC chip 4 by being connected to these pairs of terminals. The detection element 7 and the pairs of terminals are connected using eyelets and crimp terminals, or by conductive adhesive, welding, solder, etc. In this embodiment, five pairs of terminals are provided, but the number of pairs of terminals provided on the IC tag 3 (substrate 6) is not particularly limited and may be as few as one. Due to space constraints, the number of pairs of terminals provided on one IC tag 3 (substrate 6) is, for example, about 1 to 6.

[0025] It is preferable that the detection element 7 (loop circuit 9) extends to a position corresponding to the area where the degree of wear is to be determined in a plan view, and the IC tag 3 is embedded in the widthwise end of the conveyor belt 17. In this embodiment, the IC tag 3 is embedded in one widthwise end of the conveyor belt 17, and the detection element 7 (loop circuit 9) extends to the other widthwise end of the core layer 18.

[0026] The degree of wear on the surface of the conveyor belt 17 is generally the same along its entire length in the longitudinal direction L. Therefore, only one embedded object 2 can be embedded in the conveyor belt 17. To account for failures of the embedded object 2, multiple embedded objects 2 can be embedded at intervals along the longitudinal direction L of the conveyor belt 17. When embedding multiple embedded objects 2, it is also possible to mix embedded objects 2 with different burial depths for the loop circuit 9.

[0027] On the other hand, since the degree of wear on the surface of the conveyor belt 17 varies greatly in the width direction W, it is preferable to extend the detection element 7 (loop circuit 9) to cover the entire width of the core layer 18. Alternatively, since the central part of the upper cover rubber 20 is the most prone to wear in the width direction W, the detection element 7 (loop circuit 9) can also be extended to cover at least this central part in the width direction W.

[0028] The IC tag 3 can also be embedded in the center of the conveyor belt 17 in the width direction W, with the detection element 7 (loop circuit 9) extending toward both ends in the width direction. However, embedding the IC tag 3 at the widthwise ends of the conveyor belt 17 is advantageous for protecting it from impacts caused by the conveyed objects C. In this embodiment, the IC tag 3 is embedded in the upper cover rubber 20, but it can also be embedded in the lower cover rubber 21 to protect the IC tag 3 from impacts caused by the conveyed objects C. If the IC tag 3 is embedded in the lower cover rubber 21, the detector 10 is positioned to face the lower cover rubber 21.

[0029] The detector 10 employs a commonly available specification that allows for wireless communication with passive RFID tags and the like. This allows the IC tag 3 and the detector 10 to constitute an RFID (Radio Frequency Identification) system.

[0030] The detector 10 is positioned near the conveyor belt 17 and communicates wirelessly with each buried object 2 (IC tag 3) without contact with the conveyor belt 17. The transmitter 11 of the detector 10 transmits a radio wave W1 towards the IC tag 3. The receiver 12 of the detector 10 receives a reply radio wave W2 transmitted from the IC tag 3 in response to the transmitted radio wave W1. The information stored in the IC chip 4 is transmitted by the reply radio wave W2 and received by the receiver 12, thereby being acquired by the detector 10.

[0031] In this invention, the frequency of radio waves used for wireless communication is mainly in the UHF band (860MHz to 930MHz, although this varies by country; in Japan, it is 915MHz to 930MHz), but the HF band (13.56MHz) can also be used. The radio waves used may be linearly polarized or circularly polarized.

[0032] In this embodiment, the detector 10 is located on the return side of the conveyor device 15, but it can also be located on the carrier side. The distance between the detector 10 and the IC tag 3 (antenna part 5) when they are closest is set to, for example, within 1m. That is, it is preferable that the detector 10 is installed in a position where the distance between the detector 10 and the IC tag 3 (antenna part 5) is 1m or less when the IC tag 3 (antenna part 5) passes in front of the detector 10.

[0033] The calculation unit 13 is connected to the detector 10 via wired or wireless communication. A known computer or the like is used as the calculation unit 13. Various information acquired by the detector 10 is input to the calculation unit 13. The calculation unit 13 stores the burial depth (initial burial depth) of the detection element 7 (loop circuit 9) from the surface of the upper cover rubber 20, linked to element identification information that identifies the detection element 7. If the detection element 7 (loop circuit 9) is buried in the lower cover rubber 21, the burial depth (initial burial depth) from the surface of the lower cover rubber 21 is linked to the element identification information of the detection element 7 and stored in the calculation unit 13. Furthermore, the calculation unit 13 stores the burial position information (at least the position data in the longitudinal direction L) of each IC tag 3 on the conveyor belt 17, linked to tag-specific information that identifies each IC tag 3. The position information (position data in the longitudinal direction L and width direction W) of the IC tag 3 to which each detection element 7 (the loop circuit 9 formed by each detection element 7) is connected can also be linked to the identification information of each element and stored in the calculation unit 13.

[0034] Examples of warning devices 14 include alarms, warning lights, and warning indicators. The warning device 14 is connected to the calculation unit 13 via wired or wireless means so as to be able to communicate with it, and its operation is controlled by the calculation unit 13. For example, the calculation unit 13 activates the warning device 14 when it determines that the wear on the surface of the upper cover rubber 20 has progressed to the wear limit depth.

[0035] When manufacturing the conveyor belt 17, the embedded body 2 is placed inside the unvulcanized upper cover rubber 20 or lower cover rubber 21 during the molding process, and then the embedded body 2 embedded in the conveyor belt 17 is integrated with the upper cover rubber 20 or lower cover rubber 21 through the vulcanization process. To improve the work efficiency in the molding process, for example, a unit in which the embedded body 2 is sandwiched between unvulcanized rubber sheets above and below may be formed in advance, and then this unit may be placed inside the upper cover rubber 20 or lower cover rubber 21 during the molding process.

[0036] The steel cord 19 significantly affects the radio communication between the detector 10 and the IC tag 3. Therefore, if the core layer 18 is composed of many steel cords 19 arranged in parallel in the width direction, the burial direction of the IC tag 3 is set to a specific direction in which the strength of the reply radio wave W2 received by the detector 10 is higher than a predetermined threshold.

[0037] Therefore, the relationship between the burial orientation of the IC tag 3 and the strength of the reply radio wave W2 received by the detector 10 is determined in advance through preliminary tests. For example, test specimens are created on the conveyor belt 17 or a cut sample thereof, with the IC tags 3 buried in different orientations. The detector 10 is placed directly above the IC tag 3 on each test specimen, and the transmitter 11 transmits a radio wave W1 towards the IC tag 3. Then, the strength of the reply radio wave W2, which is transmitted from the IC tag 3 in response to this transmitted radio wave W1 and received by the receiver 12, is measured to determine the relationship between the burial orientation of the IC tag 3 and the strength of the reply radio wave W2. The burial orientation in which the strength of the reply radio wave W2 received by the detector 10 is higher than a predetermined threshold is identified. This threshold should be set to a value that allows for practical and stable wireless communication between the detector 10 and the IC tag 3.

[0038] When embedding the IC tag 3 in the conveyor belt 17, the IC tag 3 is embedded in this specified embedding direction. In this embodiment, a dipole antenna is used as the antenna section 5, so as illustrated in Figures 4 and 5, the IC tag 3 is embedded in the conveyor belt 17 so that the left-right direction in which the antenna section 5 extends in a plan view is perpendicular to the extending direction of the steel cord 19 (i.e., the longitudinal direction L). By embedding it in this direction, the communication state between the detector 10 and the IC tag 3 is improved, enabling stable wireless communication (and increasing the communication range).

[0039] If the core layer 18 is a fiber layer made of canvas or the like, the core layer 18 does not significantly affect the radio communication between the detector 10 and the IC tag 3. Therefore, it is not necessary to strictly specify the burial orientation of the IC tag 3, but it is advisable to specify the burial orientation as described above.

[0040] Since the burial position and orientation of the IC tag 3 on the conveyor belt 17 are fixed, it is preferable to use linear polarization rather than circular polarization to improve the wireless communication between the detector 10 and the IC tag 3. In this case, the polarization direction of the linear polarization (vertical polarization direction) is aligned with the left-right direction in which the antenna section 5 extends (i.e., parallel), and the detector 10 is positioned so that when the moving IC tag 3 passes in front of the detector 10, the detector 10 and the IC tag 3 are facing each other head-on. Even when using circular polarization, it is preferable to position the detector 10 so that when the moving IC tag 3 passes in front of the detector 10, the detector 10 and the IC tag 3 are facing each other head-on.

[0041] Next, we will explain an example of a procedure for determining the degree of wear using the detection device 1.

[0042] As illustrated in Figures 1 to 4, while the conveyor device 15 is in operation (while the conveyor belt 17 is moving), the detector 10 transmits a radio wave W1 from the transmitter 11 towards the IC tag 3 (antenna unit 5) passing in front of the detector 10. When the IC tag 3 receives the radio wave W1, it transmits a reply radio wave W2 to the receiver 12 in response to the radio wave W1.

[0043] To elaborate, if the buried object 2 (loop circuit 9) is functioning correctly, the transmitted radio wave W1 received by the antenna unit 5 powers the IC chip 4, activating it. When the IC chip 4 is activated, electricity flows from one end of the detection element 7 through the loop circuit 9 to the other end of the detection element 7 and is input to the IC chip 4. This allows the IC chip 4 to detect that the loop circuit 9 is energized. The tag-specific information of the IC tag 3 stored in the IC chip 4 and the element identification information of the detection element 7 forming the loop circuit 9 are then retrieved. When the antenna unit 5 transmits the reply radio wave W2, the retrieved tag-specific information of the IC tag 3 and the element identification information of the detection element 7 are transmitted via the reply radio wave W2 and received by the receiving unit 12.

[0044] The receiving unit 12 receives the reply radio wave W2 and acquires information (tag-specific information and element identification information) from the IC chip 4 transmitted by the reply radio wave W2. The information (tag-specific information and element identification information) acquired by the detector 10 is input to the calculation unit 13. The calculation unit 13 uses the acquired tag-specific information of each IC tag 3 to identify the buried position information of that IC tag 3 on the conveyor belt 17, which is linked to the tag-specific information that has been stored in advance. In addition, using the acquired element identification information of each detection element 7, the burial depth of that detection element 7 (the loop circuit 9 formed by that detection element 7) is identified, which is linked to the element identification information that has been stored in advance.

[0045] Thus, the calculation unit 13 determines that the detection element 7, to which element identification information has been input, is in good condition, and that the loop circuit 9 formed by this detection element 7 is energized. Furthermore, since the burial depth of the detection element 7 is known, the calculation unit 13 determines that wear has not progressed to the burial depth of the loop circuit 9 within the burial range formed by this detection element 7. In addition, since the burial position information of the IC tag 3 to which this detection element 7 is connected on the conveyor belt 17 has been identified, it can be determined that the range in which wear has not progressed to the burial depth of the loop circuit 9 is roughly near the burial position of the IC tag 3.

[0046] If the upper cover rubber 20 wears down to the burial depth of the loop circuit 9, the loop circuit 9 will be exposed to the surface and will soon break. When the loop circuit 9 breaks, even if the IC chip 4 is powered up by the transmitted radio wave W1 received by the antenna unit 5, no electricity will flow to the loop circuit 9, and the IC chip 4 will know that the loop circuit 9 is not energized. Therefore, even if the tag-specific information of the IC tag 3 stored in the IC chip 4 is retrieved, the element identification information of the detection element 7 that forms the loop circuit 9 is not retrieved. When the reply radio wave W2 is transmitted from the antenna unit 5, the retrieved tag-specific information of the IC tag 3 is transmitted by the reply radio wave W2 and received by the receiving unit 12, but the element identification information of the detection element 7 that forms the loop circuit 9 is not received by the receiving unit 12.

[0047] In other words, the information (tag-specific information) acquired by the detector 10 is input to the calculation unit 13, and the calculation unit 13 uses the acquired tag-specific information of each IC tag 3 to identify the buried position information of that IC tag 3 on the conveyor belt 17, which is linked to the tag-specific information that has been stored in advance. However, since there is no element identification information for the detection element 7 connected to that IC tag 3, it is determined that the loop circuit 9 formed by the detection element 7 is damaged. In other words, in this case, the calculation unit 13 determines that wear has progressed to the burial depth of the loop circuit 9 in the area where the loop circuit 9 is buried.

[0048] Furthermore, if the IC tag 3 is damaged due to a vertical tear or other reason, even if the transmitting unit 11 transmits radio waves W1 to the IC tag 3, the receiving unit 12 will not receive either the tag-specific information of the IC tag 3 or the element identification information of the detection element 7 connected to the IC tag 3. Therefore, it can be determined that there is an abnormality in the conveyor belt 17.

[0049] When it is determined that wear has progressed to the burial depth of the loop circuit 9, the warning device 14 is activated, informing those nearby that the upper cover rubber 20 has worn down to its limit depth. Since the burial position information of the IC tag 3 on the conveyor belt 17, for which element identification information of the connected detection element 7 cannot be obtained, is identified, it is possible to confirm that the upper cover rubber 20 has actually worn down to its wear limit depth near the burial position of the IC tag 3.

[0050] When the supervisor recognizes that the upper cover rubber 20 has worn down to its wear limit depth, they will stop the conveyor belt 17 at an appropriate time and take measures such as replacing the conveyor belt 17. After these measures are completed, the conveyor system 15 will resume operation.

[0051] This detection device 1 has a simple configuration in which the buried object 2 has a passive IC tag 3 and a linear detection element 7 connected to the IC tag 3 and extending in the width direction W of the conveyor belt 17 to form a loop circuit 9. Therefore, the buried object 2 can be made of general-purpose parts, which is advantageous for reducing costs. In addition, the detector 10 only needs to be capable of wireless communication with the buried object 2, so it can also be made of general-purpose parts, which is advantageous for reducing costs.

[0052] As described above, by using the information from the IC tag 3 transmitted to the detector 10 by the reply radio wave W2, the calculation unit 13 can accurately determine whether or not the loop circuit 9 is energized. Since the embedding depth of the upper cover rubber 20 of the loop circuit 9 from the surface is set in advance, it can be determined whether or not wear has progressed to the embedding depth of the loop circuit 9 based on the determination result of whether or not the loop circuit 9 is energized. Therefore, the degree of wear on the surface of the conveyor belt 17 (upper cover rubber 20) can be efficiently determined while the conveyor belt 17 is running, without performing complicated work.

[0053] With the reduction in the cost of the buried components 2, it becomes possible to bury multiple (many) buried components 2 in the conveyor belt 17. Therefore, it is advantageous to subdivide the area for monitoring wear and to understand the wear of the upper cover rubber 20 in more detail. By burying a number (many) of buried components 2, even if some of the buried components 2 fail, the wear can still be monitored using the remaining buried components 2.

[0054] The detection element 7 (loop circuit 9) can extend not only parallel to the width direction W, but also at an angle in the front-to-back direction (longitudinal direction L) relative to the width direction W. Extending the detection element 7 (loop circuit 9) at such an angle is advantageous for reducing (smootherly) the change in bending stiffness when the conveyor belt 17 passes around the pulleys 15a and 15b, compared to when the detection element 7 extends parallel to the width direction W (when the angle of inclination is zero). Using conductive rubber or conductive paste as the detection element 7 results in lower stiffness than metal wire, thus further reducing the bending stiffness when the conveyor belt 17 passes around the pulleys 15a and 15b.

[0055] Furthermore, if the detection element 7 is made of a thin wire with a simple circular cross-section, the detection element 7 may be cut by the sharp part of the conveyed object C when it is fed onto the conveyor belt 17. In that case, even if the wear has not progressed to the burial depth of the loop circuit 9 formed by the detection element 7, the loop circuit 9 will appear to be broken, and the calculation unit 13 will judge that the wear has progressed to that burial depth, resulting in a false detection.

[0056] Therefore, it is preferable to use a flattened linear body (a strip-shaped wire) as the detection element 7. Using a strip-shaped detection element 7 in a plan view is advantageous in avoiding the false detections mentioned above. The width of the flattened detection element 7 should be, for example, about 5 mm to 10 mm.

[0057] The buried structure 2 illustrated in Figure 7 can also be used. In this buried structure 2, multiple (5) detection elements 7a to 7e are connected to one IC tag 3. The outer surface of each detection element 7a to 7e is covered with an insulator 8. Each detection element 7a to 7e forms an independent loop circuit 9a to 9e. Therefore, multiple (5) independent loop circuits 9 are connected to one IC tag 3.

[0058] As illustrated in Figure 8, the buried structure 2 consists of independent loop circuits 9a to 9e, each embedded at intervals in the thickness direction (depth direction) of the conveyor belt 17. Note that in Figure 8, the steel cord 19 is omitted in some areas. The embedding interval in the thickness direction (depth direction) of each independent loop circuit 9a to 9e should be, for example, between 0.5 mm and 2 mm, and they should be equally spaced. The embedding depth of the loop circuit 9e, which is embedded at the deepest position, should be the wear limit depth.

[0059] When this buried object 2 is used, as the wear of the upper cover rubber 20 progresses, the loop circuits 9a, 9b, 9c, 9d, and 9e are sequentially damaged and lose their conductivity. Therefore, by using this buried object 2, the progression of wear of the upper cover rubber 20 can be understood in more detail.

[0060] By burying multiple buried bodies 2, as illustrated in Figure 5, in the conveyor belt 17 (upper cover rubber 20), and, for example, varying the burial depth of the loop circuit 9 of each buried body 2, the wear progression of the upper cover rubber 20 can be understood in more detail. However, using the buried bodies 2 illustrated in Figures 7 and 8 is advantageous in reducing the number of buried bodies 2 to be buried in the conveyor belt 17.

[0061] As illustrated in Figure 8, when each loop circuit 9a to 9e is buried with a gap in the depth direction, the positions of each loop circuit 9a to 9e in a plan view (position in the longitudinal direction L) can be the same or shifted in the longitudinal direction L. If the positions of each loop circuit 9a to 9e in a plan view (position in the longitudinal direction L) are the same, the burying work of the loop circuits 9a to 9e becomes easier. On the other hand, if the positions of each loop circuit 9a to 9e in a plan view are shifted in the longitudinal direction L, it is advantageous to make the change in bending stiffness of the conveyor belt 17 as it passes around the pulleys 15a and 15b smaller (to make the change smoother). [Explanation of Symbols]

[0062] 1. Detection device 2 Buried structures 3 IC tags 4 IC chips 5. Antenna section 6 circuit boards 6a Insulating layer 7(7a, 7b, 7c, 7d, 7e) detection element 8. Insulator 9(9a, 9b, 9c, 9d, 9e) Loop Circuit 10 detectors 11 Transmitter 12 Receiver 13 Arithmetic section 14 Alarm 15 Conveyor System 15a, 15b pulleys 16 Support rollers 17 Conveyor belt 18 Cardiac layer 19 Steel cord 20 Upper cover rubber 21 Lower cover rubber C. Transported items

Claims

1. A conveyor belt wear detection device comprising: an embedded body embedded in a conveyor belt, which is formed by integrally comprising an upper cover rubber on which conveyed material is fed, a lower cover rubber, and a core layer disposed between the upper cover rubber and the lower cover rubber; a detector that wirelessly communicates with the embedded body without contact with the conveyor belt; and a calculation unit connected to the detector, The buried object comprises a passive IC tag and a linear detection element connected to the IC tag and extending outside the IC tag to form a loop circuit, and the burial depth of the loop circuit from the surface of the conveyor belt is predetermined. The IC tag is embedded in one end of the conveyor belt in the width direction, and the loop circuit extends to the other end of the core layer in the width direction. A conveyor belt wear detection device configured such that a radio wave is transmitted from the detector toward the IC tag, and information from the IC tag is transmitted to the detector by a reply radio wave transmitted from the IC tag in response to the transmitted radio wave, and the calculation unit determines whether or not the loop circuit is energized using this information, and based on this determination result, the degree of wear on the surface of the conveyor belt in the area in which the loop circuit is embedded is determined.

2. The conveyor belt wear detection device according to claim 1, wherein the detection element is one of conductive rubber, conductive paste, or metal wire, and is a flattened strip-shaped wire.

3. A conveyor belt wear detection device according to claim 1 or 2, wherein a plurality of independent loop circuits are connected to a single IC tag, and each independent loop circuit is embedded in the conveyor belt at intervals in the thickness direction.

4. The calculation unit stores the burial depth of the loop circuit from the surface of the conveyor belt in association with element identification information that identifies the detection element forming the loop circuit, and further stores the IC tag's installation position information on the conveyor belt, at least the position data in the longitudinal direction of the conveyor belt in association with tag-specific information that identifies the IC tag, A conveyor belt wear detection device according to any one of claims 1 to 3, wherein the tag-specific information of the IC tag connected to the healthy loop circuit and the element identification information of the detection elements forming the loop circuit are transmitted by the return radio wave and received by the detector.

5. A method for detecting wear on a conveyor belt, comprising: an embedded body embedded in a conveyor belt which is composed of an upper cover rubber on which conveyed material is fed onto the upper surface, a lower cover rubber, and a core layer disposed between the upper cover rubber and the lower cover rubber as an integrated unit; a detector which wirelessly communicates with the embedded body without contacting the conveyor belt; and a calculation unit connected to the detector, The buried object comprises a passive IC tag and a linear detection element connected to the IC tag and extending outside the IC tag to form a loop circuit, and the burial depth of the loop circuit from the surface of the conveyor belt is predetermined. The IC tag is embedded in one end of the conveyor belt in the width direction, and the loop circuit is extended to the other end of the core layer in the width direction. A method for detecting wear on a conveyor belt, comprising transmitting a radio wave from the detector toward the IC tag, using information from the IC tag transmitted to the detector by a reply radio wave transmitted from the IC tag in response to the transmitted radio wave, the calculation unit determining whether or not the loop circuit is energized, and determining the degree of wear on the conveyor belt in the area where the loop circuit is embedded based on this determination result.

6. A method for detecting wear on a conveyor belt according to claim 5, wherein the core layer of the conveyor belt is composed of a large number of steel cords arranged in parallel in the width direction, the relationship between the burial direction of the IC tag and the strength of the reply radio wave received by the detector is known in advance, the burial direction in which the strength of the reply radio wave received by the detector is higher than a preset threshold is identified, and the IC tag is buried in the conveyor belt in the identified burial direction.

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