JP5870792B2 - Conveyor belt longitudinal tear detection system - Google Patents

Description

  The present invention relates to a conveyor belt longitudinal tear detection system, and more particularly, estimates the life of a loop coil that detects the conveyor belt longitudinal tear, prevents false detection due to loop coil damage, and replaces the loop coil. The present invention relates to a conveyor belt longitudinal tear detection system capable of minimizing the conveyor belt operation stop time.

  In order to detect longitudinal tearing during the running of the conveyor belt, a detection device including a loop coil embedded in the belt and a sensor for detecting the state of the loop coil is known (for example, Patent Documents 1 and 2). reference). In such a detection device, when the loop coil embedded in the belt reaches the sensor installation position by running the belt, if the loop coil is not disconnected, it is guided to the loop coil by the high frequency from the sensor transmitter. Current flows. By receiving this induced current with a sensor receiver, the presence or absence of longitudinal tearing is detected.

  By the way, the conventional loop coil has made the loop shape by connecting the both ends of a metal wire by solder welding etc. FIG. Therefore, the durability of the joint of the loop coil is not good, and when the loop coil is repeatedly bent and deformed by running the belt, the joint is damaged early. If the loop coil breaks despite the fact that the conveyor belt has not been longitudinally split, a false detection will occur when determining whether or not there is a longitudinal split.

  Further, in the conventional loop coil, the breakage of the joint is not completely broken, but is completely broken. That is, the breakage of the loop coil is grasped suddenly. Therefore, since sufficient preparation for the replacement of the loop coil cannot be made, there is a problem that the operation stop time of the conveyor belt becomes long when the loop coil is damaged.

JP-A-6-48549 JP 2005-162430 A

  The object of the present invention is to estimate the life of the loop coil that detects the longitudinal tearing of the conveyor belt, to prevent erroneous detection due to damage of the loop coil, and to minimize the operation stop time of the conveyor belt due to replacement of the loop coil. Another object of the present invention is to provide a conveyor belt longitudinal tear detection system.

  In order to achieve the above object, a conveyor belt longitudinal tear detection system according to the present invention includes a plurality of loop coils embedded in a conveyor belt stretched between pulleys at intervals in the belt traveling direction, and a predetermined vicinity of the conveyor belt. A transmitter and a receiver installed at a position; and a control means to which transmission data from the receiver is input. A high frequency is supplied from the transmitter to a running conveyor belt, and the supplied high frequency A conveyor belt longitudinal tear detection system in which a detection value indicating a state of an induced current generated in the loop coil is received by the receiver, and based on the detected value, the control means determines whether the conveyor belt is longitudinally cracked. The loop coil includes a cylindrical body configured by braiding a plurality of wires including at least one metal wire, and the cylindrical body One end in the longitudinal direction is inserted into the inside from the other end side, and the cylindrical body has a double overlapping portion, and the double overlapping portions are engaged with each other to form a loop shape. The control means estimates the life of the loop coil indicating the detected value based on the magnitude of the detected value, and issues a warning when the estimated life does not satisfy a preset reference value. Features.

  According to the present invention, the plurality of loop coils embedded in the conveyor belt at intervals in the belt running direction include a cylindrical body configured by braiding a plurality of wires including at least one metal wire. One end in the longitudinal direction of this cylindrical body is inserted into the inside from the other end side, and the cylindrical body has a double overlapping portion, and the double overlapping portions are engaged with each other to form a loop It is formed in a shape. Thereby, the bending durability and drop-out resistance of the joint of the cylindrical body are improved. As the breakage of the joint, a complete disconnection does not occur suddenly, but the disconnection gradually proceeds. Therefore, based on the magnitude of the detected value indicating the state of the induced current generated in the loop coil, the life of the loop coil indicating the detected value can be accurately estimated by the control means. Therefore, it is possible to prevent erroneous detection due to damage of the loop coil. Since a warning is issued when the estimated life does not satisfy the preset reference value, it is possible to prepare for replacement of the loop coil in advance at an appropriate time. Therefore, it is possible to minimize the conveyor belt downtime caused by the loop coil replacement.

  Here, for example, a loop coil that has once issued a warning is excluded from being issued a warning until it is replaced. This is because if the warning is continuously issued until the loop coil is replaced, it may be difficult to grasp the damage of other loop coils.

  In the loop coil of the present invention, the length of the doubly overlapped portion is preferably 150 mm or more. As a result, the resistance to slipping out of the double overlapping portion is improved, which is advantageous for improving the durability.

  The plurality of wires may be metal wires. In the case of this specification, since the number of metal wires increases, it is advantageous for improving the longitudinal tear detection performance of the conveyor belt.

1 is an overall schematic diagram of a conveyor belt longitudinal tear detection system of the present invention. It is a plane schematic diagram which illustrates the loop coil of FIG. FIG. 3 is a perspective view illustrating the vicinity of a doubly overlapping portion of the loop coil of FIG. 2. It is a top view which illustrates a part of conveyor belt with which the loop coil is embed | buried. It is a plane schematic diagram which shows the modification of a loop coil. It is a graph which illustrates the relationship between the number of repetition bending of a loop coil, and a detection value.

  The conveyor belt longitudinal tear detection system of the present invention will be described below with reference to the embodiments shown in the drawings.

  As illustrated in FIG. 1, a conveyor belt longitudinal tear detection system (hereinafter referred to as a detection system) of the present invention is installed at a plurality of loop coils 1 and a predetermined position (lower cover rubber side) near the conveyor belt 9. Transmitter 5 and receiver 6, control means 4 to which transmission data from the receiver 6 is input, warning means 4a, and monitor 4b. Each loop coil 1 is embedded in a conveyor belt 9 stretched between the driving pulley 7 and the driven pulley 8 at a predetermined interval in the belt traveling direction.

  As the control means 4, a personal computer or the like is used. Data on the rotational speed of the drive pulley 7 (belt travel speed), the embedment position of each loop coil 1 (embedding interval), and the number of bendings per belt travel are input to the control means 4. As the warning means 4 a, for example, a siren, a lighting lamp or the like is used, and its operation is controlled by the control means 4. Various data and judgment results input to the control means 4 are displayed on the monitor 4b.

  A predetermined high frequency is sequentially supplied from the transmitter 5 to the running conveyor belt 9, and an induced current is generated in the loop coil 1 by the supplied high frequency. Then, the detection value S indicating the state (magnitude) of the generated induced current is sequentially received by the receiver 6. As the detection value S, it is sufficient if the magnitude of the induced current generated in the loop coil 1 can be grasped, and a current value, a voltage value, a resistance value, or the like can be used.

  The received detection value S is sequentially input from the receiver 6 to the control means 4 as transmission data. Based on the detected value S, the control means 4 sequentially determines whether or not the conveyor belt 9 is torn. When it is determined that a vertical tear has occurred in the conveyor belt 9, the warning means 4a immediately issues a warning.

  For example, when the conveyor belt 9 is longitudinally split and the loop coil 1 is disconnected, no induced current is generated in the loop coil 1, so that the detected value S (= zero) is input to the control means 4. The Based on this detected value S, the control means 4 determines that a longitudinal tear has occurred in the conveyor belt 9. More specifically, it is determined that a vertical tear has occurred around the loop coil 1 indicating the detected value S, and the warning means 4a issues a warning. On the monitor 4b, a display for specifying the position where the loop coil 1 indicating the detected value S is embedded is displayed.

  On the other hand, if the conveyor belt 9 is healthy (no vertical tearing) and the loop coil 1 is not disconnected, the predetermined detection value S is input to the control means 4, and the control means 4 causes the conveyor belt 9 to longitudinally tear. Judge that it is not. More specifically, it is determined that no vertical tear has occurred around the loop coil 1 that indicates the detected value S.

  Further, in the present invention, the control means 4 sequentially estimates the life of the loop coil 1 indicating the detected value S based on the magnitude of the detected value S, and the estimated life is less than a preset reference value C. When this happens, the warning means 4a immediately issues a warning. The life estimation of the loop coil 1 will be described later.

  As illustrated in FIGS. 2 and 3, the loop coil 1 includes a cylindrical body 2 configured by braiding a plurality of wires 3 a (3 b) including at least one metal wire 3 a. In FIG. 2 and FIG. 5 described later, the braided wire 3a (3b) is shown only by a part of the entire length of the loop coil 1 in order to make the overall outline of the loop coil 1 easier to understand.

  As for the wire which comprises the cylindrical body 2, all may be the metal wire 3a, and two types, the metal wire 3a and the fiber wire 3b, may be sufficient as it. The number of wires is, for example, about 4 to 16. The outer diameter of the cylindrical body 2 is preferably 0.1 mm to 2.5 mm, for example.

  The metal wire 3a may be a single wire or a strand in which a plurality of strands are twisted. For example, a piano wire, a galvanized steel wire, a brass plated steel wire, etc. can be used, and a copper wire, an aluminum wire, etc. can also be used. is there. If a galvanized steel wire is used, the adhesiveness with the rubber is improved, so that excessive fluctuations are unlikely to occur at the joint of the loop coil 1. Therefore, it is advantageous for improving the durability of the joint of the loop coil 1, and accordingly, it is advantageous for improving the accuracy of the life estimation of the loop coil 1.

  The fiber wire 3b may be a single wire or a strand in which a plurality of strands are twisted, and various chemical fiber wires can be used. For example, nylon fiber wire, polyester fiber wire, etc. can be used, and natural fibers such as cotton and rayon and regenerated fibers may be used as the wire.

  One end in the longitudinal direction of the cylindrical body 2 has a portion L that is inserted into the inside from the other end side and the cylindrical body 2 overlaps twice. The double overlapping portion L becomes a joint when they are engaged with each other, and the string-like cylindrical body 2 is formed in a loop shape. The length of the double overlapping portion L is, for example, 150 mm or more, preferably 300 mm or more, and further, the entire length of the loop coil 1 is overlapped (L = 100% of the circumference of the loop coil 1). Is most preferred.

  As illustrated in FIG. 4, the loop coil 1 is embedded in the conveyor belt 9. When the conveyor belt 9 travels in the direction of arrow F and reaches the installation position of the receiver 6, if the metal wire 3 a is not disconnected, the loop coil 1 (metal wire 3 a is generated by the high frequency from the transmitter 5. ), The detected value S indicating the state of the induced current is received by the receiver 6, and the presence or absence of the longitudinal tearing of the conveyor belt 9 is determined.

  The doubly overlapping portion L that becomes a joint has a double structure of the cylindrical body 2, and the cylindrical body 2 on the inner peripheral side and the outer peripheral side are in contact with each other. For this reason, even if the loop coil 1 (cylindrical body 2) is repeatedly bent due to the traveling of the conveyor belt 9, the contact area between the inner circumferential cylindrical body 2 and the outer circumferential cylindrical body 2 is large. Stress concentration is less likely to occur, which is advantageous for improving bending durability.

  In addition, when a tensile force in the longitudinal direction (cylinder axis direction) is applied to the loop coil 1 (tubular body 2), the double overlapping portion L serving as a joint is, for example, at least 150 mm or more, Preferably, the outer cylindrical member 2 is deformed so as to be reduced in diameter by being brought into contact with 300 mm mm or more, and is more strongly engaged with the inner peripheral cylindrical member 2, so that the slip resistance is improved. Therefore, the durability when the loop coil 1 is embedded in the conveyor belt 9 and put into practical use can be improved.

  That is, even if the loop coil 1 is repeatedly bent and deformed by the running of the conveyor belt 9, it is possible to avoid a problem that the joint of the cylindrical body 2 is damaged early. Accordingly, erroneous detection of the vertical tear of the conveyor belt 9 is reduced, and the vertical tear of the conveyor belt 9 can be accurately detected.

  It is preferable that the start point and the end point of the overlapped portion L of the loop coil 1 are portions extending in the belt width direction and within the range of the central portion of the belt width 1/3. In FIG. 4, the start point and end point of the overlapped portion L are portions extending in the belt width direction above the loop, but the start point and end point are extended in the belt width direction below the loop. It may be a part. Alternatively, either one of the start point and the end point may be a portion extending in the belt width direction on the upper side of the loop, and either one may be a portion extending in the belt width direction on the lower side of the loop. In addition, the code | symbol W in FIG. 4 shows a belt width.

  As illustrated in FIG. 5, the length of the overlapped portion L can be the same as the circumference of the loop coil 1. In the case of this specification, since the cylindrical body 1 has a double structure over the entire length of the loop coil 1, the rigidity becomes uniform over the entire length, which is more advantageous for ensuring excellent durability.

  Further, when all the wires constituting the cylindrical body 2 are made of the metal wire 3a, the metal wire 3a increases, which is advantageous for improving the longitudinal tear detection performance of the conveyor belt 9.

  When the wire constituting the cylindrical body 2 is made of two types, that is, a metal wire 3a and a fiber wire 3b, the metal wires 3a are less likely to come into contact with each other and rub against each other, so that it is easy to prevent disconnection of the metal wire 3a. Therefore, it is advantageous to stably ensure the longitudinal tear detection capability.

  The outer diameter of each wire 3a (3b) is preferably set to 0.05 mm or more and 1.00 mm or less, for example, considering the balance of productivity and durability of the loop coil 1. More preferably, it is 0.1 mm or more and 0.8 mm or less.

  As illustrated in FIG. 6, when the loop coil 1 is repeatedly bent, the joint is gradually damaged (separation of the engaged metal wire 3a gradually proceeds), and the detection value S gradually decreases. In FIG. 6, the detected value S is a voltage value, and in addition to the data of the loop coil 1 of the present invention 1, data of the loop coil A (conventional example) in which both ends of one metal wire are connected by solder welding. It also shows. This data indicating the relationship between the number of repeated bends of the loop coil 1 and the detected value S is also input to the control means 4 in advance.

  As shown in FIG. 6, in the conventional loop coil A, the detection value S rapidly decreases when a certain number of bendings is reached. That is, since the joint of the loop coil A suddenly and completely breaks, the life cannot be estimated, and sufficient preparation for replacement of the loop coil A cannot be made.

  On the other hand, in the present invention, the detection value S gradually changes due to the contribution of the joint of the loop coil 1, and therefore the loop indicating the detection value S by the control means 4 based on the magnitude of the detection value S. The life of the coil 1 can be accurately estimated.

  Then, when the estimated life does not satisfy the preset reference value C (in this embodiment, when it becomes equal to or less than the reference value C), a warning is issued by the warning means 4a. For example, the estimated lifetime is about 8800 hours to 10000 hours as the reference value C. On the monitor 4b, a display for specifying the position where the loop coil 1 indicating the detected value S is embedded is displayed.

  Therefore, it is possible to prepare for replacement of the loop coil in advance at an appropriate time before the loop coil 1 becomes completely unusable. That is, since the damaged loop coil 1 can be replaced systematically, the operation stop time of the conveyor belt 9 caused by the replacement of the loop coil 1 can be minimized. It is also possible to prevent erroneous detection due to damage of the loop coil 1.

  When a voltage value or a current value is used as the detection value S, it is determined that the reference value C is not satisfied when the value is equal to or lower than the reference value C. However, when a resistance value is used as the detection value S, the reference value C It is determined that the reference value C is no longer satisfied when the above is reached.

  The warning stops after a predetermined time. And about the loop coil 1 used as the object which issued the warning once, it is set as the object which does not issue a warning until the loop coil 1 is replaced | exchanged. If the detection value S corresponding to the time point when the remaining estimated life is sufficiently long is set as the reference value C, the loop coil 1 showing the detection value S that does not satisfy the reference value C has a certain life at that time. There is no need to replace it immediately. In such a case, if the warning is continued, it becomes difficult to grasp the damage of the other loop coils 1. Therefore, it is preferable not to issue a warning until the loop coil 1 is replaced.

DESCRIPTION OF SYMBOLS 1 Loop coil 2 Cylindrical body 3a Metal wire 3b Fiber wire 4 Control means 4a Warning means 4b Monitor 5 Transmitter 6 Receiver 7 Drive pulley 8 Drive pulley 9 Conveyor belt L The part which overlapped twice

Claims (4)

  A plurality of loop coils embedded in a conveyor belt stretched between pulleys at intervals in the belt traveling direction, a transmitter and a receiver installed at predetermined positions in the vicinity of the conveyor belt, and transmission from the receiver Control means to which data is input, and a high frequency is supplied from the transmitter to a running conveyor belt, and a detection value indicating a state of an induced current generated in the loop coil by the supplied high frequency is received by the receiver. A conveyor belt longitudinal tear detection system that receives and determines the presence or absence of a conveyor belt longitudinal tear by the control means based on the detected value, wherein the loop coil includes a plurality of loops including at least one metal wire. The cylindrical body is formed by braiding the wire, and one end in the longitudinal direction of the cylindrical body is inserted into the inside from the other end side so that the cylindrical body is doubled over. A loop in which the double overlapping portions are engaged with each other to form a loop, and the control means indicates the detection value based on the magnitude of the detection value. A conveyor belt longitudinal tear detection system that estimates a coil life and issues a warning when the estimated life does not satisfy a preset reference value.   The conveyor belt longitudinal tear detection system according to claim 1, wherein the loop coil that has once issued a warning is not subject to a warning until it is replaced.   3. The conveyor belt longitudinal tear detection system according to claim 1, wherein a length of the doubly overlapped portion is 150 mm or more. 4.   4. The conveyor belt longitudinal tear detection system according to claim 1, wherein all of the plurality of wires are metal wires.

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