JP2007284150A - Monitoring method and device for conveyor belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitoring method and device for a conveyor belt capable of correcting deviation of a measurement value of a magnetic sensor by the meandering of the conveyor belt and accomplishing monitoring at high accuracy. <P>SOLUTION: In the monitoring method for the conveyor belt 2, a rubber magnet 3 is buried in the conveyor belt 2 and variation of the situation of the conveyor belt is detected by measuring variation of magnetic force of the rubber magnet 3 by the magnetic sensor 4 arranged at a position where the rubber magnet 3 is passed. A meandering amount of the conveyor belt 2 is measured by a meandering measurement means and a measurement value of magnetic force of the rubber magnet 3 measured by the magnetic sensor 4 is corrected based on the measured meandering amount. Thereby, variation of the situation of the conveyor belt 2 is detected. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the present invention, a permanent magnet is embedded in a conveyor belt, and a change in the magnetic force of the permanent magnet is measured by a magnetic sensor disposed at a position through which the permanent magnet should pass, thereby causing wear, elongation, breakage, etc. of the conveyor belt. The present invention relates to a conveyor belt monitoring method and apparatus for detecting a change in the physical state of the conveyor belt.

Conventionally, as a method for detecting wear of a conveyor belt, a magnetic field from a rubber magnet embedded in the conveyor belt and exposed on the surface of the conveyor belt is detected by a magnetic sensor, and a magnetic force is reduced by decreasing the volume of the rubber magnet as the wear of the conveyor belt progresses. There is a technique in which the degree of wear of the conveyor belt is obtained from the magnitude of the detected magnetic force by utilizing the change in the angle (see, for example, Patent Document 1).
JP 2005-138879 A

  However, what is described in Patent Document 1 has a problem that when the conveyor belt meanders, the rubber magnet is also displaced in the belt width direction, so that the measured value of the magnetic sensor is lowered and the wear amount cannot be detected accurately. there were.

  In view of the above-described problems of the conventional technology, the present invention provides a conveyor belt monitoring method and apparatus that corrects a magnetic sensor measurement value due to the meandering of the conveyor belt and enables high-precision monitoring. It is intended to provide.

According to the present invention, the above problem is solved as follows.
(1) A change in the physical state of the conveyor belt by embedding a permanent magnet in a conveyor belt and measuring a change in magnetic force of the permanent magnet by a magnetic sensor disposed at a position where the permanent magnet should pass. In the method for monitoring a conveyor belt, the amount of meandering of the conveyor belt is measured, and the measured value of the magnetic force of the permanent magnet measured by the magnetic sensor is corrected based on the measured amount of meandering. , Detecting a change in the physical state of the conveyor belt.

(2) In the above item (1), the amount of decrease in the measured value of the magnetic force of the permanent magnet by the magnetic sensor when the conveyor belt is meandered with respect to the measured value of the magnetic force of the permanent magnet by the magnetic sensor in the normal state. The measurement value is corrected in advance by measuring in advance according to the amount and adding the decrease amount to the measurement value of the magnetic force by the magnetic sensor in accordance with the meandering amount of the conveyor belt being monitored.

(3) In the above item (1), the rate of decrease in the measured value of the magnetic force of the permanent magnet by the magnetic sensor when the conveyor belt is meandered relative to the measured value of the magnetic force of the permanent magnet by the magnetic sensor in the normal state The measurement value is corrected in advance by measuring in advance according to the amount and by adding the rate of decrease with respect to the measurement value to the measurement value of the magnetic force by the magnetic sensor in accordance with the meandering amount of the conveyor belt being monitored.

(4) In the above items (1) to (3), the permanent magnet is a rubber magnet magnetized in the thickness direction, and a magnetic sensor is used to measure a decrease in magnetic force due to wear of the rubber magnet accompanying wear of the conveyor belt. To detect wear of the conveyor belt.

(5) A change in the state of the conveyor belt is detected by measuring a change in the magnetic force of the permanent magnet with a magnetic sensor embedded in the conveyor belt and disposed at a position where the permanent magnet should pass. In the conveyor belt monitoring apparatus, a meandering measuring means for measuring the meandering amount of the conveyor belt, a memory for storing a correction value corresponding to the meandering amount, and the conveyor belt measured by the meandering measuring means Based on the amount of meandering, a correction calculation that corrects the measured value of the magnetic force measured by the magnetic sensor with the corresponding correction value stored in the memory and outputs the corrected measured value as a corrected measured value Means.

According to the present invention, the following effects can be achieved.
According to the first aspect of the present invention, the measurement value of the magnetic force detected by the magnetic sensor can be corrected based on the amount of meandering of the conveyor belt, and the deviation of the measurement value of the magnetic sensor due to the meandering of the conveyor belt can be corrected. Highly accurate monitoring is possible.

  According to the second aspect of the present invention, the amount of decrease in the measured value of the magnetic force of the permanent magnet by the magnetic sensor when the conveyor belt is meandered with respect to the measured value of the magnetic force of the permanent magnet by the magnetic sensor in the normal state Because the measured value is corrected by adding the amount of decrease to the measured value of the magnetic force by the magnetic sensor according to the meandering amount of the conveyor belt being monitored, the measured value is easily corrected. And it can correct correctly.

  According to the invention of claim 3, the rate of decrease in the measured value of the magnetic force of the permanent magnet by the magnetic sensor when the conveyor belt is meandered with respect to the measured value of the magnetic force of the permanent magnet by the magnetic sensor in the normal state In accordance with the amount of meandering of the conveyor belt being monitored, the measured value is corrected by calculating the rate of decrease relative to the measured value to the measured value of the magnetic force by the magnetic sensor. Even when the absolute value of the magnetic force measured by the magnetic sensor being monitored fluctuates greatly, the measured value can be corrected with the same reduction rate, and a number of different correction values can be set according to the magnitude of the absolute value of the measured value. There is no need to prepare, correction work is easy, and correction value data input can be simplified.

  According to the invention described in claim 4, even when the conveyor belt meanders, it is possible to accurately know the degree of wear of the conveyor belt.

  According to the fifth aspect of the present invention, it is possible to correct the deviation of the measured value of the magnetic sensor due to the meandering of the conveyor belt only by adding the meandering measuring means, the memory and the correction calculating means to the existing conveyor belt monitoring device. Therefore, it is possible to provide a conveyor belt monitoring device with high accuracy and simple structure.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 is a side view of an unloading side end portion of a belt conveyor including an embodiment of the present invention, FIG. 2 is an enlarged vertical side view of a portion II in FIG. 1, and FIG. 3 is a line III-III in FIG. It is an enlarged view.

The conveyor belt monitoring device of this embodiment is a rubber magnet (3) which is a permanent magnet embedded with its surface exposed on the surface layer (2a) side of the conveyor belt (2) wound around the pulley (1). ) And a magnetic sensor (4) that is disposed near the place where the conveyor belt (2) should pass and detects the magnetic force from the rubber magnet (3).
The conveyor belt (2) is formed in a multilayered manner with a reinforcing layer (2c) made of canvas or the like sandwiched between a surface layer (2a) made of rubber and a back surface layer (2b).

  The rubber magnet (3) is magnetized in the thickness direction. The rubber magnet (3) can be embedded in the surface of the conveyor belt (2) at the time of manufacturing the belt. However, if the rubber magnet (3) is embedded in the junction (endless portion) (5) between the ends of the conveyor belt (2), This is preferable because the embedding work is easy. However, the burial location is not limited.

  As the rubber magnet (3), a bonded magnet in which magnet powder is dispersed and mixed in a rubber matrix and formed into a sheet shape is magnetized in the thickness direction, and a plurality of bonded magnets thus formed are used. Those laminated and integrated by adhesion or re-vulcanization are preferably used. Such a bonded magnet can be formed thin, but also has high flexibility and can easily follow the deformation of the conveyor belt (2).

  The magnet powder is generally ferrite, but a strong magnetic force can be imparted by using a rare earth magnet such as neodymium iron boron or samarium iron nitrogen, or an alco magnet.

  The magnetic sensor (4) can be a gauss meter and is arranged as close as possible to the passing position of the rubber magnet (3). The mounting position of the magnetic sensor (4) is preferably on the return side of the conveyor belt (2) as shown in FIGS. Thereby, the conveyed product conveyed with the conveyor belt (2) can be detected in the clean location after being scraped off by the scraper (6).

  As shown in FIGS. 2 and 3, in the vicinity of the magnetic sensor (4), there is provided a width direction guide (7) for regulating the position in the width direction of the conveyor belt (2) passing therethrough. On the opposite side of the sensor (4), a thickness direction guide (8) is provided to keep the relationship between the conveyor belt (2) and the magnetic sensor (4) constant. The rubber magnet (3) is embedded with a predetermined width in the width direction of the conveyor belt (2).

  Since the wear of the conveyor belt (2) starts from the surface side used for conveyance, the rubber magnet (3) is scraped from the surface side, and the magnetic force gradually decreases. The decrease in the magnetic force is detected by the magnetic sensor (4) and the measured value of the magnetic force measured by the magnetic sensor (4) is corrected by the correction calculation means (13) described later, thereby accurately detecting the degree of wear. can do.

FIG. 4 shows an example of meander measuring means (9) of the conveyor belt.
In this example, the meandering measuring means (9) is provided on a fixed body (not shown) on the side of the pulley (1), and the side end face (2d) of the conveyor belt (2) wound around the pulley (1). By accurately measuring the distance to the point, the amount of meandering (L) from the normal position when the conveyor belt (2) meanders, that is, the amount of deviation of the side end face (2d) can be accurately measured. A rangefinder (10) is provided.

  However, the meandering measuring means (9) may be any means as long as it can accurately measure the meandering of the conveyor belt (2). For example, the meandering measuring means (9) includes a light wave range finder, a laser range finder, etc. Sometimes.

FIG. 5 is a block diagram showing an example of a control device in the conveyor belt monitoring device of the present invention.
As shown in the figure, the control device (11) includes a memory (12) for storing a correction value corresponding to the meandering amount (L) of the conveyor belt (2), a magnetic sensor (4), and a meandering measurement. Magnetic force measured by the magnetic sensor (4) based on the meandering amount (L) of the conveyor belt (2) connected to the means (9) and the memory (12) and measured by the meandering measuring means (9) And a correction operation means (13) for correcting the measured value (G) by a corresponding correction value stored in the memory (12) and outputting the corrected measured value as a corrected measured value.

  Next, a method for correcting the measured value of the magnetic force measured by the magnetic sensor (4) will be described in detail along with the procedure for monitoring the conveyor belt.

  The magnetic force distribution of the rubber magnet (3) when the conveyor belt (2) is in a normal state not meandering is measured in advance. That is, the conveyor belt (2) in a normal state is run on a test, and the strength of the magnetic force is measured by the magnetic sensor (4) immediately above each position in the left-right direction of the rubber magnet (3). The intensity of the magnetic force measured at this time is shown in correspondence with the position of the rubber magnet (3), resulting in a magnetic force distribution curve (14) indicated by a solid line in FIG.

  Further, the thickness of the rubber magnet (3) is reduced stepwise, and the same measurement is performed. If the strength of the magnetic force at this time is shown corresponding to the position of the rubber magnet (3), the magnetic force distribution curves (15), (16) and (17) indicated by broken lines in FIG. 6 are obtained.

These magnetic distribution curves (14), (15), (16), and (17) have a parabolic shape in which the central portion of the rubber magnet (3) has a peak value (P).
In addition, as the change width of the thickness of the rubber magnet (3) is reduced, a larger number of magnetic force distribution curves are obtained, and the accuracy can be increased.
The data of these magnetic force distribution curves (14), (15), (16), and (17) are stored in the memory (12).

During the actual operation of the conveyor belt (2), as described above, the magnetic sensor (4) detects the magnetic force of the rubber magnet (3), and the ultrasonic range finder (10) detects the conveyor belt (2). Measure the meandering amount (L).
When the conveyor belt (2) is in a normal state without meandering, the magnetic sensor (4) detects the peak value (P) of the magnetic force distribution curve (14). The measured value (G) is corrected by the correction calculation means (13). Since the meandering amount (L) at this time is zero, the correction amount is also zero, and the measured value (G) remains as it is. The corrected measurement value is output from the correction calculation means (13).

  However, when the conveyor belt (2) meanders, the peak value (P) shifts to the side according to the meandering amount (L), and the magnetic force distribution curve (14 ') shown in FIG. Since the magnetic force at the position measurement point (14a) is measured and the peak value (P) cannot be detected accurately, the wear amount cannot be detected accurately.

  Therefore, the meandering amount (L) measured by the ultrasonic range finder (10) is input to the correction calculating means (13), and the correction calculating means (13) uses the magnetic sensor based on the meandering amount (L). The measured value of the magnetic force at the low measurement point (14a) detected in (4) is corrected so as to return to the peak value (P) of the original magnetic force distribution curve (14). Thereby, even if meandering occurs and the peak value shifts, the wear amount of the rubber magnet (3) can be accurately determined, and the belt wear amount can be detected with high accuracy.

There are the following two methods for correcting the measured value (G).
One of them is the rubber magnet (4) when the conveyor belt (2) is meandered against the measured value (G0) of the magnetic force of the rubber magnet (3) by the magnetic sensor (4) in a normal state. 3) The amount of decrease (ΔG) in the measured value (G1) of the magnetic force is measured in advance according to the meandering amount (L), and according to the meandering amount (L) of the conveyor belt (2) being monitored, In this method, the measured value (G) is corrected by adding the amount of decrease (ΔG) to the measured value (G) of the magnetic force by the magnetic sensor (4).
According to this method, the measured value (G) can be corrected easily and accurately.

  Another method is that the rubber magnet by the magnetic sensor (4) when the conveyor belt (2) is meandered against the measured value (G0) of the magnetic force of the rubber magnet (3) by the magnetic sensor (4) in a normal state. The decrease rate (%) of the measured value (G1) of magnetic force (3) is measured in advance according to the amount of meandering (L), and according to the amount of meandering (L) of the conveyor belt (2) being monitored. In this method, the measured value (Gx) is corrected by adding the rate of decrease (%) with respect to the measured value (G0) to the measured value (Gx) of the magnetic force by the magnetic sensor (4).

  According to this method, even if the absolute value of the measured value (G) of the magnetic force by the magnetic sensor (4) being monitored fluctuates greatly, the measured value (G) can be corrected with the same reduction rate (%). It is not necessary to prepare a number of different correction values (such as the above-mentioned reduction amount (ΔG)) according to the magnitude of the absolute value of the measured value (G0), making correction work easy and inputting correction value data. Can be simplified.

  As mentioned above, although embodiment which applied this invention to the monitoring method and apparatus of the conveyor belt for detecting abrasion of a conveyor belt was described, this invention is not limited to this, A permanent magnet is used for a conveyor belt. A method of monitoring any conveyor belt, wherein a change in the state of the conveyor belt is detected by measuring a change in the magnetic force of the permanent magnet with a magnetic sensor embedded in a position where the permanent magnet passes. It can be applied to the device.

  For example, the present invention can be applied to a conveyor belt monitoring method and apparatus for detecting conveyor belt elongation. That is, a plurality of rubber magnets (3) and (3) are arranged along the traveling direction of the conveyor belt (2), and the distance between the front and rear rubber magnets (3) and (3) is detected, so that the conveyor belt Elongation can be detected. In this case as well, the distance traveled by meandering of the conveyor belt (2) is measured by the meandering measuring means (9), checked against the magnetic distribution of the rubber magnet (3), and corrected based on the meandering amount (L). Thus, it is possible to accurately detect the elongation of the conveyor belt (2).

In the present invention, the present invention is not limited to the above embodiment, and can be implemented in various modified forms.
For example, instead of the rubber magnet (3), a permanent magnet made of a material other than rubber may be used, or a plurality of permanent magnets stacked in such a manner that their polar directions are alternately reversed upside down. You can also.

It is a side view of the unloading side edge part of a belt conveyor provided with one Embodiment of this invention. It is an expanded sectional view of the II part of FIG. FIG. 3 is an enlarged view taken along line III-III in FIG. 1. FIG. 4 is a view taken along line IV-IV in FIG. 1. It is a block diagram of a control apparatus. It is a figure which shows the magnetic force distribution curve of a rubber magnet.

Explanation of symbols

(1) Pulley
(2) Conveyor belt
(2a) Surface layer
(2b) Back layer
(2c) Reinforcing layer
(2d) Side end face
(3) Rubber magnet (permanent magnet)
(4) Magnetic sensor
(5) Joint
(6) Scraper
(7) Width direction guide
(8) Thickness direction guide
(9) Meander measuring means
(10) Ultrasonic ranging finder
(11) Control device
(12) Memory
(13) Correction calculation means
(14) (15) (16) (17) Magnetic distribution curve
(14a) Measurement point
(P) Peak value

Claims (5)

A change in the physical state of the conveyor belt is detected by measuring a change in the magnetic force of the permanent magnet by a magnetic sensor embedded in the conveyor belt and disposed at a position where the permanent magnet should pass. In the conveyor belt monitoring method,
The meandering amount of the conveyor belt is measured, and based on the measured meandering amount, the measurement value of the magnetic force of the permanent magnet measured by the magnetic sensor is corrected to detect a change in the physical state of the conveyor belt. A method for monitoring a conveyor belt.   The amount of decrease in the measured value of the magnetic force of the permanent magnet by the magnetic sensor when the conveyor belt is meandered relative to the measured value of the magnetic force of the permanent magnet by the magnetic sensor in a normal state is measured in advance according to the amount of meandering, 2. The method of monitoring a conveyor belt according to claim 1, wherein the measured value is corrected by adding the amount of decrease to the measured value of the magnetic force by a magnetic sensor in accordance with the meandering amount of the conveyor belt being monitored. .   The decrease rate of the measured value of the magnetic force of the permanent magnet by the magnetic sensor when the conveyor belt is meandered with respect to the measured value of the magnetic force of the permanent magnet by the magnetic sensor in a normal state is measured in advance according to the amount of meandering, 2. The conveyor according to claim 1, wherein the measured value is corrected by adding the rate of decrease to the measured value to the measured value of the magnetic force by the magnetic sensor according to the meandering amount of the conveyor belt being monitored. Belt monitoring method.   The permanent magnet is a rubber magnet magnetized in the thickness direction, and the wear of the conveyor belt is detected by measuring the decrease in magnetic force due to the wear of the rubber magnet accompanying the wear of the conveyor belt by a magnetic sensor. The monitoring method of the conveyor belt in any one of Claims 1-3. A change in the state of the conveyor belt is detected by measuring a change in the magnetic force of the permanent magnet by a magnetic sensor embedded in the conveyor belt and disposed at a position where the permanent magnet should pass. Conveyor belt monitoring device
Meander measuring means for measuring the amount of meander of the conveyor belt;
A memory for storing correction values corresponding to the meandering amount;
Based on the meandering amount of the conveyor belt measured by the meandering measuring means, the magnetic force measurement value measured by the magnetic sensor is corrected by the corresponding correction value stored in the memory, and the corrected measurement value is obtained. A conveyor belt monitoring apparatus comprising: a correction calculation unit that outputs the corrected measurement value.

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