Belt conveyor load break detection device

Abstract

To provide a cargo running out detection device of a belt conveyor capable of coping even when operated under severe condition.SOLUTION: A cargo running out detection device of a belt conveyor 1 is composed of a support rod 11 provided above the belt conveyor 1 so as to cross the belt conveyor 1, a swingable swing part 12 hanging down from an axially central part of the support rod 11, an abutting part 13 connected to a lower end part of the swing part 12 and in contact with an object to be conveyed under conveyance by the belt conveyor 1, and a sensor part 14 that detects as a cargo running out when the swing part 12 hangs down in a vertical direction, and a plate-shaped part 13b having a lower surface that intersects an extending direction of the abutting part 13 is attached to a tip of the abutting part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a device for detecting a load shortage on a belt conveyor. [Background technology]

[0002] In factories that handle powdered ore such as non-ferrous metal smelting plants for lead, zinc, etc., it is common to arrange multiple belt conveyors in series to transfer the powdered ore to a specified location. In this case, if an abnormality occurs in the upstream belt conveyor or in a hopper or feeder that supplies the powdered ore to the belt conveyor, the transport of the transported material will be interrupted, making it difficult to stably supply the transported material to the downstream processing process. As a result, it becomes necessary to operate at a low load, which is inefficient, and in some cases, the entire factory will have to be shut down.

[0003] In addition, when the conveyor belt stops conveying the objects (this phenomenon is sometimes called "load break"), the belt tends to run unstable, such as meandering, due to the empty operation of the belt conveyor, which can result in the belt being damaged. When the belt is damaged, it takes time to replace or repair it, and during that time the supply of the objects to the subsequent process is interrupted, which can also lead to the shutdown of the entire factory.

[0004] In order to prevent the above situation from occurring, it is necessary to quickly detect and restore the load of the conveyor belt when the load of the conveyor belt runs out. For this reason, in the past, in order to confirm that the conveyor belt is continuously and stably transporting the conveyor belt without the load running out, an operator was made to monitor the transport status of each conveyor belt on-site. Alternatively, the above-mentioned load running out on the conveyor belt is detected by monitoring the transport status of the conveyor belt with a surveillance camera or by introducing a sensor that physically contacts the conveyor belt while the conveyor belt is transporting the conveyor belt.

[0005] For example, Patent Document 1 discloses a technology for detecting the running out of smelting raw materials being transported on a conveyor belt using a contact-type load-out detection device. Specifically, the load-out detection device in Patent Document 1 is composed of a number of detection levers that tilt in the transport direction when they come into contact with the objects being transported on the conveyor belt, a number of position detection switches such as magnetic proximity switches that are provided opposite each of the detection levers, and a detection circuit that detects the operating state of these switches. It is described that the load-out detection device can reliably and quickly detect the running out of objects being transported on the conveyor belt, such as smelting raw materials. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 09-301525 Summary of the Invention [Problem to be solved by the invention]

[0007] However, visual monitoring by an operator sometimes makes it difficult to find problems accurately and quickly due to human error, etc. Also, when a large amount of dust is generated from the transported object, accurate monitoring becomes difficult when monitoring with a surveillance camera because the dust adheres to the lens surface of the surveillance camera, and when the transported object is transported under high temperature and high humidity conditions, the camera body can easily break down.

[0008] In addition, when the conveying speed of the belt conveyor is set faster than normal or when the conveyed object contains a corrosive substance such as chlorine, the tip of the detection lever is likely to be significantly worn or corroded, and repair or replacement may require a long time. The present invention has been made in consideration of the above circumstances, and has an object to provide a detection device that can stably detect the load break of the belt conveyor even when the conveyed object is conveyed under severe conditions, such as when the conveying speed of the belt conveyor is set relatively fast or when the conveyed object is conveyed under conditions such as a high-temperature and high-humidity atmosphere, a corrosive atmosphere, or a dust-producing atmosphere. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a belt conveyor load break detection device that includes a support bar that is provided above the belt conveyor and crosses the belt conveyor, a swingable swinging portion that hangs down from the axial center of the support bar, a contact portion that is connected to the lower end of the swinging portion and comes into contact with an object being transported by the belt conveyor, and a sensor portion that detects a load break when the swinging portion hangs down in the vertical direction, and a plate-shaped portion having a lower surface that intersects with the extension direction of the contact portion is attached to the tip of the contact portion. The swinging portion and the abutting portion are connected to each other by a flange. It is characterized by the fact that Effect of the Invention

[0010] According to the present invention, a load break on a belt conveyor can be detected stably even when transporting objects under harsh conditions. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a front view of an embodiment of the cargo shortage detection device of the present invention. [Diagram 2] 2 is a side view of the load-out detection device of FIG. 1 taken along line II-II. [Diagram 3] 2 is a partial perspective view of a specific example of a leg portion supporting the load-out detection device of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of a load-break detection device for a belt conveyor according to the present invention will be described with reference to the drawings. A belt conveyor generally comprises a head pulley and a tail pulley rotatably provided at the front and rear ends of a skeletal frame, respectively, and an endless belt wound around these pulleys. When a belt conveyor having such a structure conveys raw materials for a non-ferrous metal refining process, such as lead and zinc, as the transported objects, these raw materials contain abrasive materials such as iron oxide and silicon dioxide, and corrosive components such as chlorine and fluorine. In a device that detects a load break by simply physically contacting a detection part with the raw materials being transported, it takes time and effort to repair or replace the detection part that has been worn out due to wear or corrosion.

[0013] In addition, when a large amount of raw materials needs to be transported, the transport speed of the belt conveyor may be set to a high speed, and in this case, the detection part of the load-out detection device that physically contacts the transported object quickly wears out due to wear, and repairing or replacing it requires time and effort. The load-out detection device of the embodiment of the present invention is configured to stably detect the load-out of the belt conveyor even when the transported object is transported under such harsh conditions.

[0014] That is, as shown in FIG. 1, the cargo-break detection device of an embodiment of the present invention is composed of a support rod 11 made of a round metal bar arranged above the belt conveyor 1 so as to cross the belt conveyor 1, a metal oscillating part 12 that can swing and hangs down from the axial center of the support rod 11, a metal abutment part 13 that is connected to the lower end of the oscillating part 12 and abuts against the transported object on the surface of the belt B of the belt conveyor 1, and a sensor part 14 that detects a cargo break when the oscillating part 12 hangs down vertically.

[0015] The sensor unit 14 may be a contact type or a non-contact type proximity sensor, but it is preferable to use a non-contact type proximity sensor. Examples of non-contact type proximity sensors include an induction type, a capacitance type, and a magnetic type. The induction type is a method of detecting an overcurrent caused by electromagnetic induction generated when a metal detection target approaches the proximity sensor by a change in impedance, the capacitance type is a method of detecting a change in electrical capacitance generated when a metal detection target approaches the proximity sensor, and the magnetic type is a method of operating a reed switch of the proximity sensor by a magnet provided on the detection target. In FIG. 1, the abutment part 13 is shown as the detection target, but the detection target is not limited to this, and the protrusion part or the swinging part 12 provided on the support rod 11 may be the detection target.

[0016] In addition, when a contact type sensor such as a limit switch is used instead of the above-mentioned non-contact type proximity sensor, for example, a limit switch striker protruding in the radial direction can be provided at one end of the support rod 11, and this limit switch striker can be made to abut against the limit switch when the oscillating part 12 hangs down vertically due to a loss of load.

[0017] Regardless of which method is adopted for the sensor unit 14, as shown in FIG. 2, it is necessary to set the sensor unit 14 so that it does not detect when the tip of the contact part 13 contacts the transported object being transported by the belt conveyor 1 and the swinging part 12 is tilted at an inclination angle θ from the vertical direction to the transport direction of the belt conveyor 1. In this case, the inclination angle θ is preferably within a range of 20 to 45°, which makes it possible to more accurately detect the load shortage of the transported object on the belt conveyor 1. If the inclination angle θ is less than 20°, the sensor unit 14 may erroneously detect the load shortage when the transport amount of the transported object transported by the belt conveyor 1 varies. Conversely, if the inclination angle θ exceeds 45°, the transported object is likely to come into contact with a flange pair (described later) that connects the swinging part 12 and the contact part 13 to each other, which is not preferable.

[0018] As a method for adjusting the inclination angle θ of the swinging part 12, for example, as shown in FIG. 1, the support rod 11 may be rotatably supported on a pair of legs 3, preferably made of L-shaped steel, provided on a frame 2 supporting a head pulley and a tail pulley (not shown) of the belt conveyor 1, and each of the pair of legs 3 may be structured to be height adjustable. Note that a beam 4, preferably made of L-shaped steel, is preferably spanned between the upper ends of the pair of legs 3. As an example of the height adjustable structure, for example, as shown in FIG. 3(a), the legs 3 may be structured with a movable upper part 3a having a round bolt hole for inserting a bolt and a fixed lower part 3b having a long hole extending in the vertical direction for inserting a bolt. Note that instead of the fixed lower part 3b having the long hole, a fixed lower part 3c may be structured to have a plurality of round bolt holes for inserting a bolt lined up in a vertical row, as shown in FIG. 3(b).

[0019] 2, the cargo-out detection device according to the embodiment of the present invention is preferably provided with a stopper 15 at a position that abuts against the oscillating part 12 when hanging vertically, so that the oscillating part 12 does not oscillate in the opposite direction to the conveying direction of the belt conveyor 1. This makes it less likely that the abutting part 13 of the cargo-out detection device will be damaged or that the sensor part 14 will make a false detection. The stopper 15 is preferably made of an elastic material such as rubber.

[0020] In addition, in the load-break detection device according to the embodiment of the present invention, it is preferable that the swinging portion 12 and the abutment portion 13 are connected to each other by flanges, and specifically, it is preferable that the flange 12a provided at the lower end of the swinging portion 12 and the flange 13a provided at the upper end of the abutment portion 13 are fastened to each other by bolts and nuts. This makes it possible to easily replace the abutment portion 13 with a spare abutment portion 13 by simply removing the bolts and nuts when the abutment portion 13 becomes worn due to contact with the transported load.

[0021] Alternatively, as a method of connecting the oscillating part 12 and the abutting part 13, other than the above flange-type connection method, for example, a plug-in connection method may be used in which the oscillating part 12 and the abutting part 13 are formed of a round bar and a pipe, respectively, and the round bar is inserted into the inside of the pipe to an appropriate length and screwed from the side of the pipe. This plug-in connection method has the advantage of being somewhat simpler in structure and handling than the above flange-type connection method. For example, when adjusting the inclination angle θ of the oscillating part 12 as described above, in the case of the flange-type connection method, the leg part 3 that pivots on the support rod 11 must be structured to be height adjustable as described above, but in the plug-in connection method, the adjustment can be easily made by simply changing the length of the round bar inserted into the pipe.

[0022] However, the flange-type connection method has the advantage that the bolts and nuts connecting the flanges are not likely to fall off, whereas the plug-in connection method has the advantage that the screws may loosen relatively early. That is, when the conveyor belt 1 is used for transport, the objects to be transported are piled up in a continuous mountain shape to prevent the objects from falling off as much as possible, but the conveyor belt 1 may have a transport speed of several meters per second, so that the contact part 13 and the oscillating part 12 connected thereto, which are constantly in contact with the objects to be transported at such a high speed, are constantly vibrating violently. For this reason, in the plug-in connection method, the screws of the connection part are screwed in perpendicular to the direction of extension of the contact part and the oscillating part, which are constantly vibrating, so that the screws are likely to loosen and fall off. In contrast, in the flange-type connection method, the bolts and nuts of the flanges are tightened in a direction parallel to the direction of extension of the contact part 13 and the oscillating part 12, which are constantly vibrating, so that the bolts and nuts are not likely to loosen and the possibility of falling off can be suppressed.

[0023] In the cargo break detection device according to the embodiment of the present invention, a metal plate-shaped portion 13b having a lower surface intersecting the extending direction of the contact portion 13 is preferably attached to the tip of the contact portion 13. Since the lower surface of the plate-shaped portion 13b is always rubbed against the continuous mountain-shaped transported objects, it is preferable that at least the lower surface side is covered with a wear-resistant material, and since the belt of the belt conveyor 1 vibrates up and down, the plate-shaped portion 13b often sinks into the transported objects, it is more preferable that in addition to the lower surface side, the side surface side and the upper surface side are all covered with the wear-resistant material.

[0024] Furthermore, the plate-shaped portion 13b is preferably curved with respect to the conveying direction of the belt conveyor 1. By curving in this way, it is possible to smoothly rub along the continuous mountain-shaped conveyed object, and it is also possible to make it difficult for the plate-shaped portion 13b to sink into the conveyed object. The curved shape may be curved over the entire surface from the upstream end to the downstream end with respect to the conveying direction of the belt conveyor 1 as shown in FIG. 2, or only the downstream end may be curved like a ski. Alternatively, it may be curved in a hemispherical or semi-elliptical shape in all directions.

[0025] Although the cargo breakage detection device of the present invention has been described above with reference to an embodiment, the present invention is not limited to the above embodiment and can include various modifications and alternatives without departing from the scope of the present invention. For example, the cargo breakage detection device of the embodiment of the present invention may have a structure in which the short tube portion 12b shown in FIG. 1 rotates relative to the support rod 11. In this case, both ends of the support rod 11 can be fixed to the legs 3. Alternatively, the plate-shaped portion 13b may be movably attached to the abutment portion 13 so that the lower surface of the plate-shaped portion 13b can move along the upper surface of the mountain-shaped transported object. EXAMPLES

[0026] [Example 1] In order to detect the break in the belt conveyor, a break detection device with a structure as shown in Fig. 1 was installed. Specifically, a support rod 11 made of a round rod made of SS400 with a diameter of φ25 mm and a length of 800 mm was installed above the belt conveyor 1 in a direction crossing the belt conveyor 1. This support rod 11 was rotatably attached by pillow-shaped bearings (UCP204) installed on legs 3 erected on frames 2 on both sides of the belt conveyor 1.

[0027] The swinging part 12, which is a round bar made of SS400 and has a diameter of φ15 mm and a length of 100 mm, is attached to hang down from the center of the axial direction of the support rod 11, and further, the abutting part 13, which is a round bar made of SS400 and has a diameter of φ22 mm and a length of 300 mm, is connected to the tip of the swinging part 12 with a flange. A pair of square flanges with short sides of 50 mm, long sides of 100 mm, and a thickness of 6 mm were used for the flanges, and were attached so that the flange surfaces were perpendicular to the axial direction of the swinging part 12 and the abutting part 13 and the short sides were parallel to the conveying direction of the belt conveyor 1. Two sets of M12 bolts and nuts were used to connect these flanges together.

[0028] A plate-shaped portion 13b made of SS400 having a thickness of 6 mm, a width of 30 mm, and a length of 60 mm was attached to the tip of the contact portion 13 so that the lower surface side was perpendicular to the axial direction of the contact portion 13. A wear-resistant material having a Vickers hardness of 650 HV or more and containing 5 mass% or more of carbon, 22 mass% or more of chromium, and 6 mass% or more of niobium was applied to the entire surface of the plate-shaped portion 13b by overlay welding. The plate-shaped portion 13b was curved with respect to the conveying direction of the belt conveyor 1. A sensor portion 14 consisting of a non-contact sensor was provided at a position facing the contact portion 13 when the swinging portion 12 was hung down in the vertical direction. The belt conveyor 1 equipped with the load-break detection device having the above structure was conveyed at a conveying speed of 55 m / min to convey the conveyed object at a conveying amount of 145 t / h, and the load break occurring at that time was detected by the above detection device.

[0029] [Example 2] A round bar made of SS400 with a diameter of φ15 mm and a length of 170 mm was used for the oscillating part 12, and a round pipe made of SS400 with a diameter of φ22 mm and a length of 300 mm was used for the abutting part 13, and the oscillating part 12 made of a round bar was inserted 70 mm into the abutting part 13 made of this round pipe, and screw holes were made in two places above and below the part of the round pipe that overlapped with the round bar, and M10 bolts were inserted into these screw holes to fix the part in place. A load break occurring on the belt conveyor 1 was detected in the same manner as in Example 1 except for the above.

[0030] [Comparative Example] Instead of using the oscillating part 12 and the contact part 13 of Example 1, a rod-shaped member was used, in which a plate-shaped part made of SS400, having a thickness of 6 mm, a width of 30 mm, and a length of 60 mm, to which no wear-resistant material was overlaid, was connected to the tip so as to be perpendicular to the axial direction. Apart from the above, the load break occurring on the belt conveyor 1 was detected in the same manner as in Example 1.

[0031] It was confirmed that the detection device of Example 1 can be used for more than one year without any particular maintenance. In the detection device of Example 2, since the fixing bolts of the attachment part of the round bar and the round pipe were loosened, it was confirmed that the detection device can be used for more than one year without the round pipe falling off by tightening the bolts once a month. On the other hand, in Comparative Example 1, the plate-shaped part at the tip wore out about six months after the start of operation, so it was replaced with a spare part before it could no longer detect properly. This replacement took about one hour, and the operating rate of the belt conveyor decreased. [Explanation of symbols]

[0032] 1. Conveyor belt 2 Frames 3 legs 3a Movable upper part 3b, 3c fixed lower part 4 Beam section 11 Support rod 12 Swinging part 12a Flange 12b Short pipe section 13 Contact part 13a Flange 13b Plate-shaped part 14 Sensor section 15 Stopper B Belt

Claims

1. A cargo break detection device for detecting a break in a belt conveyor, comprising: a support rod arranged above the belt conveyor and crossing the belt conveyor; a swingable oscillating part hanging down from the axial center of the support rod; a contact part connected to the lower end of the oscillating part and contacting an object being transported by the belt conveyor; and a sensor part for detecting a break in the cargo when the oscillating part hangs down in the vertical direction, wherein a plate-shaped part having a lower surface that intersects with the extension direction is attached to the tip of the contact part, and the oscillating part and the contact part are connected to each other by a flange.

2. 2. The load-break detector according to claim 1, wherein an abrasion-resistant material is used at least on a lower surface side of said plate-like portion that comes into contact with said transported object.

3. 3. The cargo break detection device according to claim 1, wherein the plate-shaped portion is curved with respect to a conveying direction of the belt conveyor.

Images