Conveyor belt monitoring system

Abstract

Conveyor belt monitoring system (1), comprising: a meander detection device that detects a meander width (Z) of a conveyor belt (11) during operation; a control unit (3) which receives detection data collected by the meander detection device (2); and a meander suppression device (5) controlled by the control unit (3), wherein the meander detection device is an imaging device (2) which sequentially images a predetermined longitudinal region of the conveyor belt (11) from above, and a monitor (4) in which the image data acquired by the imaging device (2) are displayed, and the control unit (3) receives the image data as recognition data to cause the meander suppression device (5) to reduce a meander width (Z) of the conveyor belt (11) on the basis of the image data, characterized in that an angle (a) formed in a side view of the conveyor belt (11) by a surface of the conveyor belt (11) and an imaging direction of the imaging device (2) is set to less than 90°, so that the conveyor belt (11) is imaged in a conical image.

Description

Technical area

[0001] The present invention relates to a conveyor belt monitoring device, and more particularly, to a monitoring device with high versatility capable of accurately reducing a meander width and simultaneously sequentially determining an operating state and a state of a conveyed object at a desired position of a conveyor belt in the longitudinal direction thereof. State of the art

[0002] Various objects, including mineral raw materials such as iron ore and limestone, are transported by a conveyor belt. The objects are fed from a hopper or other conveyor belt onto an upper cover rubber of the conveyor belt. The tension acting on the conveyor belt varies due to changes in the fed objects in terms of load weight, load position, and the like. Due to the variation in tension, it is possible for the conveyor belt to meander. An excessive meander width of the conveyor belt will cause an object to fall off and damage the conveyor belt, so it is desirable to reduce the meander width.

[0003] JP 2003 327317 A discloses a conveyor belt whose offset can be detected and automatically corrected. More specifically, JP 2003 327317 A discloses a conveyor belt deviation detector that detects the deviation of the conveyor belt during operation, a control section to which the detection data obtained from the conveyor belt deviation detector is input, and idler pulleys controlled by the control section.

[0004] A known method involves detecting a meander width of a conveyor belt with a non-contact sensor, such as an ultrasonic sensor, arranged, for example, on the side of a disc (referring to paragraph

[0002] and Fig. 8 in JP 2009 166947 A). Unfortunately, this method detects a meander width of the conveyor belt at the disc, so that a meander width at a desired position between the discs with maximum meander width cannot be accurately determined.

[0005] Subsequently, a monitoring system for accurately determining the meandering state of a conveyor belt was proposed (referring to paragraphs

[0007] to

[0017] , etc., in JP 2009 166947 A). The monitoring system proposed in this document is configured to detect a magnetic field from a magnet embedded in a conveyor belt using a magnetic field detection unit. Based on the detection of the magnetic field with the magnetic field detection unit, a meandering state of the conveyor belt is determined. This requires integrating a magnet into the conveyor belt. Therefore, the monitoring system cannot be applied to an existing conveyor belt. Furthermore, the magnetic field detection unit is arranged near the magnet embedded in the conveyor belt, so that a meandering state of the conveyor belt on its back side without a loaded conveyed object is detected.Thus, the meandering state of the conveyor belt at a desired position in its longitudinal direction cannot be accurately determined. Furthermore, the state of an object loaded onto the conveyor belt cannot be determined. Summary of the inventionTechnical problem

[0006] The object of the present invention is to provide a conveyor belt monitoring system with high versatility, which is capable of accurately reducing a meander width and simultaneously sequentially determining an operating state and a state of a conveyed object at a desired position of a conveyor belt in its longitudinal direction. Solution to the problem

[0007] To achieve the above-described object, a conveyor belt monitoring system according to the present invention comprises a meander detection device that detects a meander width of a conveyor belt during operation, a control unit that receives detection data acquired by the meander detection device, and a meander suppression device controlled by the control unit. The meander detection device is an imaging device that sequentially images a predetermined longitudinal range of the conveyor belt from above and includes a monitor on which the image data acquired by the imaging device is displayed. The control unit receives the image data as detection data to cause the meander suppression device to reduce a meander width of the conveyor belt based on the image data.An angle formed by a surface of the conveyor belt and an imaging direction of the imaging device in a side view of the conveyor belt is set to less than 90°, so that the conveyor belt is imaged in a conical image. Advantageous effects of the invention

[0008] According to the present invention, the imaging device, which sequentially images the predetermined longitudinal region of the conveyor belt from above as a meander detection device, is used to display the acquired image data on the monitor. Thus, an operating state and a condition of the conveyed object at a desired position of the conveyor belt in its longitudinal direction can be determined sequentially using the image data displayed on the monitor.

[0009] The control unit causes the meander suppression device to reduce the meander width of the conveyor belt based on the image data. Accordingly, the present invention does not require any special processing for a conveyor belt, so the monitoring system has a very high versatility that can be easily applied to an existing conveyor belt. Additionally, a meander width is determined at a desired position of the conveyor belt in the longitudinal direction to reduce the meander width, thus achieving an advantage in accurately suppressing the meander width. Brief description of the drawings Fig. 1 is an explanatory diagram illustrating a conveyor line in side view to which a conveyor monitoring device of the present invention is applied. Fig. 2 is an explanatory diagram showing the conveyor belt of Fig. 1 on one side of the beam with a cross-section in the longitudinal direction. Fig. 3 is an explanatory diagram showing a meander suppression device of Fig. 1 in a top view. Fig. 4 is an explanatory diagram showing the meander control means of Fig. 3 in operation in a top view. Fig. 5 is an explanatory diagram illustrating image data on a conveyor belt (when it exists in a normal range) taken by an imaging device. Fig. 6 is an explanatory diagram illustrating image data on a conveyor belt (when it exists in an abnormal area) captured by the imaging device. Fig. 7 is an explanatory diagram showing a temporal change in the meander width of a conveyor belt imaged by the imaging device in a plan view. Description of embodiments

[0010] A conveyor belt monitoring system according to the embodiments of the present invention will be described below with reference to the drawings.

[0011] A conveyor belt wear monitoring system 1 (hereinafter referred to as “System 1”) of an embodiment of the Fig. The present invention illustrated in FIG. 1 is applied to a conveyor belt 11 of an operating conveyor line. In the system 1, a meander width Z is suppressed, and an operating state of the conveyor belt 11 at a desired position in its longitudinal direction and a state of a conveyed object C are sequentially determined. The meander width Z is a misalignment amount of the conveyor belt 11 in its transverse direction. The meander width Z is a numerical value indicating the amount of transverse displacement of the conveyor belt 11 with respect to the conveyor belt 11 in a state where the transverse center of the conveyor belt 11 is aligned with the transverse center of the conveyor line (normal state).

[0012] As in Fig. As shown in Figure 2, the conveyor belt 11 monitored by Appendix 1 includes a core layer 12 made of canvas or steel cables, and an upper cover rubber 13 and a lower cover rubber 14 that sandwich the core layer 12. The core layer 12 carries the tension when the conveyor belt 11 is stretched and installed. The conveyor belt 11 may include additional necessary components if necessary. Fig. 2, the transverse center line of the conveyor belt 11 is shown as a dot-dashed line CL and the transverse center line of the conveyor belt line is shown as a dot-dashed line M.

[0013] The conveyor belt 11 is stretched and mounted with a predetermined tension on a drive pulley 7a and a driven pulley 7b. Between the drive pulley 7a and the driven pulley 7b, the conveyor belt 11 is supported by support rollers 9 arranged at appropriate intervals in the longitudinal direction of the conveyor belt.

[0014] On a support side of the conveyor belt 11, the lower cover rubber 14 is supported by the support rollers 9 arranged at predetermined positions spaced apart from each other in the longitudinal direction of the conveyor belt 11. On a back side of the conveyor belt 11, the upper cover rubber 13 is supported by the support rollers 9 arranged at predetermined positions spaced apart from each other in the longitudinal direction of the conveyor belt 11.

[0015] On the carrier side, three support rollers 9 are arranged next to each other in the transverse direction of the conveyor belt at predetermined positions in the longitudinal direction of the conveyor belt 11. The conveyor belt 11 is supported by the support rollers 9 in a recessed manner with a predetermined trough angle.

[0016] The drive pulley 7a is rotationally driven by a drive motor 8, and the conveyor belt 11 runs in a longitudinal direction using the rotation of the drive pulley 7a. A take-up mechanism 10 moves the driven pulley 7b to apply tension to the conveyor belt 11 (core layer 12) by changing the distance between the drive pulley 7a and the driven pulley 7b.

[0017] In the embodiment, the conveyor belt 11 has a shape in which it slopes downwards and upwards once in the middle of operation from the drive pulley 7a to the driven pulley 7b. That is, the conveyor belt line has the lowest point at its center position. The present invention can be applied to the conveyor belt line not only in the form described above but also in various forms. For example, the present invention can also be applied to a conveyor belt line in a smooth downward slope form, a smooth upward slope form, or a flat shape.

[0018] The system 1 includes at least one imaging device 2, such as a digital video camera, which serves as a meander detection device that detects a meander width of the conveyor belt 11 during operation. The system 1 also includes a control unit 3, a monitor 4, and a meander suppression device 5. Furthermore, the system 1 of the embodiment includes a warning device 6. Examples of the warning device 6 include a warning light, an alarm, and the like.

[0019] The control unit 3 is configured to use a computer and the like. The control unit 3 is wired or wirelessly connected to the imaging device 2, the monitor 4, the meander suppression device 5, the warning device 6, and the drive motor 8. The control unit 3 controls the operation of the meander suppression device 5, the warning device 6, and the drive motor 8.

[0020] The imaging devices 2 each sequentially images a predetermined longitudinal range of the conveyor belt 11 from above. All of the imaging devices 2 of the embodiment are arranged on the support side of the conveyor belt 11. Specifically, the imaging devices 2 are each arranged at a position where the conveyed object C is fed onto the conveyor belt 11, a lowermost position of the belt line conveyor with the maximum tension change in the conveyor belt 11, and a position near the driven pulley 7b. The image data acquired by the imaging device 2 is sequentially input to the control unit 3 as recognition data. The image data is also sequentially displayed on the monitor 4.

[0021] An angle α formed by the surface of the upper cover rubber 13 of the conveyor belt 11 and an imaging direction of each of the imaging devices 2 is set, for example, to 30° or more and 90° or less. In the embodiment, the angle α is set to about 45°.

[0022] The meander suppression device 5 serves to reduce the meander width Z of the conveyor belt 11. The meander suppression device 5 of the embodiment is provided below the support rollers 9, which are arranged at three consecutive locations spaced apart from each other in the longitudinal direction of the conveyor belt 11 on the support side of the conveyor belt 11.

[0023] As in Fig. 3, the meander suppression device 5 includes a movable bracket that tilts the carrier-side support rollers 9 in the transverse direction of the conveyor belt 11 in plan view. Fig. 3, the axis of the support rollers 9 is indicated by the dot-dash line WL. The meander suppression device 5 is rotated about an intersection point P of the axis WL and the transverse center line M of the conveyor line to incline the support rollers 9 in the transverse direction of the conveyor belt 11 in a plan view.

[0024] As in Fig. As shown in Figure 4, when the meander suppression device 5 rotates clockwise around the intersection point P, the support rollers 9 are inclined so that their left side becomes the front side in a plan view in the transverse direction of the conveyor belt 11. This acts on the operating conveyor belt 11, where the external force causes the conveyor belt 11 to be displaced to the right in its operating direction. Thus, when the conveyor belt 11 moves to the left in the operating direction, the meander width Z can be reduced by controlling the meander suppression device 5 as already described.

[0025] When the conveyor belt 11 meanders to the right in the operating direction, the meander suppression device 5 is rotated counterclockwise around the intersection P. This tilts the support rollers 9 so that their right side becomes the front side in the plan view in the transverse direction of the conveyor belt 11. As a result, an external force is applied to the operating conveyor belt 11, which causes the conveyor belt 11 to be shifted to the left in its operating direction, so that the meander width Z can be reduced.

[0026] Although in this embodiment, all three support rollers 9 arranged in the belt transverse direction can be inclined in the longitudinal direction of the conveyor belt 11 in a plan view in the transverse direction, the present invention is not limited to this structure. For example, only the support rollers 9 arranged at the respective ends in the belt transverse direction can be inclined in the transverse direction of the conveyor belt 11 in a plan view by the meander suppression device 5.

[0027] Next, a method for monitoring the conveyor belt 11 operated by the system 1 is described.

[0028] In the conveyor line, the conveyed object C is fed to the upper cover rubber 13, for example, via a hopper or the like, while the conveyor belt 11 is operating. Each of the imaging devices 2 sequentially images a predetermined longitudinal range of the passing conveyor belt 11 from above, and the acquired image data is input to the control unit 3.

[0029] As in the Fig. 5 and Fig. 6, the monitor 4 displays the image data acquired by each of the imaging devices 2 in real time. The arrow in the Fig. 5 and Fig. 6 indicates an operating direction of the conveyor belt 11. The control unit 3 stores the Fig. 7 shown image data. The Fig. 5 to 7 each show a first warning line L1 and a second warning line L2 extending in the longitudinal direction of the conveyor belt 11 outside each of the transverse ends of the conveyor belt 11. The lines L1 and L2 are each set at a position laterally separated from the transverse center line M of the conveyor belt line by a predetermined distance.

[0030] When the angle a formed by the surface of the upper cover rubber 13 of the conveyor belt 11 and an imaging direction of each of the imaging devices 2 is reduced, an imaging longitudinal target range increases and the conveyor belt 11 is imaged in a conical image as shown in FIGS. Fig. 5 and Fig. 6. Thus, the angle a is set to 30° to 90° and preferably to 45° to 90°.

[0031] When the conveyor belt 11 is located in an area between the first warning lines L1, it can be said that the meander width Z is small. Thus, the area is stored in the control unit 3 as a normal area S of a meander width. When the conveyor belt 11 is located in an area outside the normal area S, it can be said that the meander width Z is large. Thus, the area is stored in the control unit 3 as an abnormal area D.

[0032] In the Fig. 5, the transverse center line CL of the conveyor belt 11 is substantially aligned with the transverse center line M of the conveyor belt line, so that the meander width Z is almost zero. That is, the conveyor belt 11 exists in the normal range S, so that the control unit 3 determines that the meander width Z is small in the normal state. Thus, the control unit 3, as shown in Fig. 3, maintains a state in which the axis WL of the support rollers 9 is orthogonal to the transverse center line CL of the conveyor belt 11 without operating the meander suppression device 5.

[0033] In the Fig. 6, the cross-center line CL conveyor belt 11 is shifted greatly to the left of the cross-center line M of the conveyor belt path to make the meander width Z large. That is, the conveyor belt 11 exists in the abnormal area D, so that the control unit 3 determines that the meander width Z is large in an abnormal state. Thus, the control unit 3, as shown in Fig. 4, the meander suppression device 5 tilts the axis WL of the support rollers 9 from the transverse center line CL of the conveyor belt 11. This shifts the conveyor belt 11 to the right to reduce the meander width Z.

[0034] Fig. 7 shows a temporal change of the meander width Z. The graph of Fig. 7 shows a lower end indicating an updated state (meander width Z) of the operating conveyor belt 11, and shows a previous state upwards. The monitor 4 can also display the change over time in the meander width Z, as in Fig. 7 shown.

[0035] As described above, in the embodiments of the present invention, the control unit 3 causes the meander suppression device 5 to reduce the meander width Z based on the image data acquired by the imaging devices 2. To reduce the meander width Z with the meander suppression device 5, a method other than the above-mentioned control method may be used. For example, the operation of the meander suppression device 5 may be controlled so that the transverse center line M of the conveyor belt line is always aligned with the transverse center line CL of the conveyor belt 11.

[0036] Using the system 1 of the embodiments of the present invention allows a supervisor or the like at the construction site to sequentially determine an operating state of the conveyor belt 11 and a state of the conveyed object C at a desired position by visually checking the image data displayed on the monitor 4. This allows estimation that an increase in the meander width Z is caused by, for example, the displacement of a loaded position of the conveyed object C.

[0037] The embodiments of the present invention do not require any special processing for embedding a magnet into the conveyor belt 11 or the like and can therefore be easily applied to an existing conveyor belt. This results in a monitoring system with extremely high versatility.

[0038] Furthermore, the system 1 of the embodiments of the present invention enables imaging of a predetermined longitudinal range by the imaging devices 2, which can be set at a desired position. This allows the meander width Z to be reduced by determining the meander width Z of the conveyor belt 11 at a desired position in its longitudinal direction. That is, a state of the conveyor belt 11 at a position where the conveyor line has the maximum meander width Z can be monitored to accurately suppress the meander width Z at that position.

[0039] The predetermined longitudinal range of the conveyor belt 11 imaged by the imaging devices 2 is adjusted according to a tension change acting on the conveyor belt 11 during operation, for example. In this case, the tension acting on the operating conveyor belt 11 is preliminarily measured at several positions of different longitudinal positions of the conveyor belt 11. Subsequently, the range to be imaged is set to include a position with the largest tension fluctuation among the measured positions. The position with the largest tension fluctuation tends to have the maximum meander width Z. Thus, image data on the conveyor belt 11 can be imaged at a position with the maximum meander width Z by adjusting the range to be imaged by the imaging devices 2 as described above.

[0040] In the embodiments, when the control unit 3 determines that the conveyor belt 11 exists in the abnormal area D, the control unit 3 causes the warning device 6 to operate to notify a supervisor or the like on the construction site that the meander width Z of the conveyor belt 11 is increasing. For example, the abnormal area D may be divided into an area (initial warning area) between the second warning lines L2 and an area (important warning area) outside the area between the second warning lines L2. When the conveyor belt 11 exists in the important warning area, the meander width Z should be larger than that when the conveyor belt 11 exists in the preliminary warning area. Then, the first case and the second case each have a different warning method (type) with the warning device 6.For example, if conveyor belt 11 is in the important warning area, a warning tone will be played louder than if conveyor belt 11 is in the pre-warning area in order to more strongly alert a supervisor or the like.

[0041] If the control unit 3 determines that the conveyor belt 11 is continuously present in the abnormal area D for a predetermined time in the image data, the control unit 3 may also stop the operation of the conveyor belt 11. If the control unit 3 determines as described above, it is conceivable that the meander suppression device 5 does not function to sufficiently suppress the meander width Z. Thus, the conveyor belt 11 is stopped so that the conveyor belt line is inspected in detail. List of reference symbols 1 surveillance system 2 imaging device (meander detection device) 3 Control unit 4 monitors 5 Meander suppression device 6 Warning device 7a Drive pulley 7b Driven pulley 8 Drive motor 9 Support roller 10 Winding mechanism 11 Conveyor belt 12 core layer 13 Upper cover rubber 14 Lower cover rubber

Claims

[1] Conveyor belt monitoring system (1), comprising: a meander detection device that detects a meander width (Z) of a conveyor belt (11) during operation; a control unit (3) which receives detection data collected by the meander detection device (2); and a meander suppression device (5) controlled by the control unit (3), wherein the meander detection device is an imaging device (2) which sequentially images a predetermined longitudinal region of the conveyor belt (11) from above, and a monitor (4) in which the image data acquired by the imaging device (2) are displayed, and the control unit (3) receives the image data as recognition data to cause the meander suppression device (5) to reduce a meander width (Z) of the conveyor belt (11) on the basis of the image data, characterized by , that an angle (a) formed in a side view of the conveyor belt (11) by a surface of the conveyor belt (11) and an imaging direction of the imaging device (2) is set to less than 90°, so that the conveyor belt (11) is imaged in a conical image. [2] Conveyor belt monitoring system (1) according to claim 1, wherein a plurality of the imaging devices (2) are arranged at positions spaced apart from one another in the longitudinal direction of the conveyor belt (11). [3] Conveyor belt monitoring system (1) according to claim 1 or 2, wherein a normal range (S) in which the conveyor belt (11) is present when the meander width (Z) is within a permissible range and an abnormal range (D) in which the conveyor belt (11) is present when the meander width (Z) is outside the permissible range are preliminarily set, the control unit (3) receives area position data about the normal area (S) and the abnormal area (D), and the control unit (3) causes the meander suppression device (5) to reduce the conveyor belt (11) in meander width (Z) when the control unit (3) determines that the conveyor belt (11) is present in the abnormal area (D) of the image data. [4] Conveyor belt monitoring system (1) according to claim 3, further comprising a warning device (6) which issues a warning by instruction of the control unit (3) when the control unit (3) determines that the conveyor belt (11) is present in the abnormal area (D) of the image data. [5] Conveyor belt monitoring system (1) according to claim 3 or 4, wherein, when the control unit (3) determines that the conveyor belt (11) is continuously present in the abnormal area (D) for a predetermined time in the image data, the control unit (3) prevents the conveyor belt (11) from operating. [6] Conveyor belt monitoring system (1) according to one of claims 1 to 5, wherein a predetermined longitudinal region of the conveyor belt (11) to be imaged by the imaging device (2) is set to include a position with the greatest tension fluctuation acting on the conveyor belt (11) during operation.

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