JPS62285813A - Longitudinal crack detecting device for conveyer belt - Google Patents

Abstract

PURPOSE:To make it possible to perform crack detection without affection of even variations in speed, by providing a means for detecting the travel distance of a conveyer belt with the use of the number of pulses, and a memory means for storing the positions of embedded members to be detected in accordance with the number of pulse signals. CONSTITUTION:A belt position detecting means is composed of a plurality of metal plates 8 attached to one side surface of a drive pulley 3 for a conveyer belt 4, and a proximity switch 9 arranged outside, for detecting these metal plates 8 to deliver pulse signals. Further, the progress of the conveyer belt 4 is detected with the use of the number of pulse signals generated in association with the rotation of the drive pulley 3. The positions of embedded resonance circuits 5 in the conveyer belt 4, which may be obtained from the number of pulse signals from the proximity switch 9, is stored in a memory means in a control device 10. The control device 10 stops the operation of the conveyer belt 4 or issues an alarm if the number of pulse signals from the proximity switch 9 exceeds a predetermined value when one of the resonance circuits 5 is broken due to a longitudinal crack in the conveyer belt 4 so that a detector delivers 6 no electrical signal even though the resonance circuit 5 passes over the detector 6.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Technical Field of the Invention] This invention automatically detects vertical cracks in a conveyor belt during use and stops the belt from running. This relates to a device that causes alarms and generates alarms.

[Prior art]

Generally, when conveying objects such as ore using a large, endless conveyor belt, the conveyor belt is scratched or vertically cracked due to protrusions of the object when it is dropped or transported. Sometimes.

If a conveyor belt is vertically cracked in this way, it will not only hinder the conveyance operation but also cause great damage.

Therefore, as a countermeasure to this problem, conventionally, devices have been used that are capable of detecting longitudinal cracks when they occur in a conveyor belt. , various types are known.

The internal longitudinal crack detection device has objects to be detected, such as resonant circuits, loop coils, conductive wires, etc., buried inside the conveyor belt at intervals in the longitudinal direction of the heald, and the normality of the objects to be detected is detected from the outside of the conveyor belt. This method uses a detector installed at the This will be explained with reference to FIGS. 4 and 5. As shown in FIG. As the conveyor belt 4 is passed over the rack, as shown in FIG.
Resonant circuits 5 made up of C are embedded at regular intervals.

On the other hand, below the movement trajectory of the coil portion 5a of the resonant circuit 5 in the conveyor belt 4, the normality of the resonant circuit 5 is detected using the inductance change caused by the resonance phenomenon with the coil portion 5a, and an electric current is generated. A detector 6 for outputting a signal is installed, and this detector 6 is connected to a control device 7.

If a vertical tear occurs in the conveyor belt 4 currently in use, a part of the resonant circuit 5 buried in the conveyor heald 4 will be cut off, and even if a part of the resonant circuit 5 is cut off in this way, Even if it passes over the detector 6, the resonance phenomenon becomes small, so it is not detected by the detector 6, and therefore the detector 6 does not output an electrical signal. The above control device 7
Under normal usage conditions, that is, when there are no longitudinal cracks in the conveyor belt 4, the electric signal from the detector 6 is detected within a certain period of time depending on the buried spacing of the resonant circuit 5. 4 is normal, but if a longitudinal crack occurs as described above and the detector 6 no longer detects it, the detector 6 will not output an electrical signal even after a certain period of time has elapsed, so there is no possibility of such a situation. If an electric signal is not obtained even after a certain period of time has elapsed, a warning is issued because the conveyor belt 4 has vertically torn, and the operation of the conveyor belt 4 is stopped.

In this way, if a vertical tear occurs in the conveyor bell 1-4, it is exposed and the heald conveyor device 1 is stopped.

However, with such conventional internal vertical crack detection devices,
If the detector 6 detects the joint of the magnetic material steel cord belt in the conveyed object and outputs an erroneous signal, or if the conveyor belt 4 longitudinally tears due to the influence of external electrical noise, the conveyor system immediately There was a problem that 1 may not stop. If such an erroneous signal or noise is transmitted to the control device 7, the resonant circuit 5 that comes immediately after it
Even if the conveyor belt 4 is cut due to a vertical tear, the conveyor belt 4 does not stop immediately1. Therefore, in the event of a vertical tear, the conveyor belt 4 does not stop immediately. Even above, it lacks reliability.

It is also affected by changes in the speed of the conveyor belt 4,
For example, when the conveyor belt 4 does not reach a constant speed at the start of operation, there is a possibility of malfunction, so control during this period is not possible, and reliability is also lacking in this respect.

[Purpose of the invention]

This invention was made in view of the above points,
The purpose of this is to prevent malfunctions caused by verbal signals and noise and improve page reliability, and to prevent vertical tearing without being affected by changes in the speed of the conveyor belt. We provide a conveyor belt vertical tear detection device (which can detect vertical cracks).

[Structure of the invention]

In order to achieve the above-mentioned object, the present invention is a device for detecting longitudinal cracks by embedding a detected object in a conhair belt and using a detector installed outside the conhair belt. A means for detecting by the number of pulses, a storage means for storing the buried position of the object to be detected according to the number of pulse signals from the detection means, and a storage means for storing the buried position when a signal from the detector is obtained. The gist of the present invention is to include a control device that compares the stored contents of the signal with the stored contents and determines whether the signal is a regular signal based on the passage of the object to be detected.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows a schematic configuration of a longitudinal crack detection device for a conveyor belt according to an embodiment of the present invention, and FIG. 2 is a partially enlarged view thereof. In this example, a resonant circuit similar to that shown in Fig. 5 is used as the object to be detected buried in the conveyor belt, and the same reference numerals are used for the same components as in Fig. 4. It is attached.

As shown in FIG. 1, this longitudinal crack detection device is provided with a detector 6 facing a conveyor belt 4 which is suspended between a driving pulley 2 and a driven pulley 3. Similar to the conventional longitudinal crack detection device, a plurality of resonant circuits 5 having the configuration shown in FIG. 5 are embedded at intervals of 4.

The detector 6 is a detection coil provided to resonate with the resonant circuit 5 of the conhair hold 4, and includes an oscillation circuit that oscillates at the same frequency as the resonant circuit 5. When it passes, a resonant current flows through the detection coil in the detector 6 due to resonance, indicating that the resonant circuit 5 in the conveyor belt 4 is normal, that is, the conveyor belt 4
It is detected that no longitudinal crack has occurred in the sensor and an electrical signal is output. On the other hand, if a longitudinal crack occurs and the resonant circuit 5 is cut off, the resonant circuit 5 does not resonate even if it passes over the detector 6. Therefore, no resonant current flows through the detection coil and no electrical signal is output.

Furthermore, as shown in FIGS. 1 and 2, in this longitudinal crack detection device, for example, a plurality of metal plates 8 are arranged at equal intervals on one side of the driven pulley 3 as pulley rotation detected members. A proximity switch 9 as a pulse signal generator for non-contact detection of the metal plate 8 is provided at a portion opposite to the rotation locus of the metal plate 8.
is installed. These constitute a belt position detection means. Several metal plates 8 are attached to the side of the driven boob IJ 3 of the conveyor belt 4, and a proximity switch that detects the metal plates 8 and emits a pulse signal is connected externally. The progress of the conveyor belt 4 is detected by the number of pulse signals generated as the driven pulley 3 rotates.

The detector 6 and proximity switch 9 for detecting the resonant circuit are:
Each is connected to a control device 10.

This control device 10 includes a storage means such as a microcomputer, and a judgment means, and the storage means of the control device 10 stores the buried position of the resonant circuit 5 of the conveyor belt 4 based on the number of pulse signals from the proximity switch 9. . That is, when the conveyor heald 4 is driven by the drive pulley 2, the driven pulley 3 also rotates along with the conveyor belt 4, and a pulse signal is output from the proximity switch 9.
In this case, in order to remove the erroneous signals and noises that cause malfunctions as described above, the control device 10 operates after the resonant circuit 5 passes over the detector 6 while the conveyor heald 4 makes one revolution. Until the next resonant circuit 5 passes over the detector 6, the pulse signals output from the proximity switch 9 are counted and sequentially stored in the storage means. Since the number includes errors due to elongation and slippage of the conveyor belt 4, a tolerance range of plus or minus several runs 1-(n,) is set for the actual count number (Mi), and (Mi ±
n) Handled within the scope of counting.

This work is usually carried out during no-load operation when no objects are placed on it to avoid the influence of noise. Each resonant circuit 5 stored between
The maximum number of pulse signal counts obtained according to the interval is set as M max, and (Mmax + n) counts are stored as the maximum count number.

When the memory means of the control device 10 stores the embedded position of the resonant circuit 5 in advance in this way, and an electric signal is obtained from the detector 6, it is checked against the memory contents of the control device 10 to determine whether the signal is a regular signal. It is determined whether the signal is an erroneous signal or noise, and control is applied only if the signal is a normal signal.

Next, the door control device 10 during normal operation of the conveyor held 4
To explain the operation according to the flowchart of FIG. 3, first, in step (2), the control device 1o starts counting the number of pulse signals from the proximity switch 9, and then, in step (2), it checks whether there is an electric signal from the detector 6. A determination is made whether or not.

If a YES determination result is obtained in this determination step (2), the process proceeds to step (2), and if No, the process proceeds to step (2).

Now, suppose that an electric signal is obtained at the connection terminal with the detector 6 in steps (2) and the process proceeds to step (2).In this step (2), it is determined whether or not an electric signal is obtained at the position where it should be output. That is, it is determined whether the count number of the pulse signal at the time when the electric signal is obtained is within the range of (Mi ±n) counts. If the count number of the pulse signal from the proximity switch 9 is within the above range, and therefore the determination result in step (2) is YES, this means that the above electric signal was obtained by passing through the normal resonant circuit 5. , proceed to step (2) in order to prepare for the next resonant circuit 5. That is,
In this case, assume that there are no longitudinal cracks in the conveyor belt 4, move to the step knob ■, clear the pulse signal count once, start counting again, return to step ■, and perform the following steps. Make sure to repeat.

In addition, in step (2) above, if the count number of the pulse signal at the time when the electric signal is obtained is
) If it is not within the count range, the electrical signal was obtained from a source other than the buried resonant circuit 5. Therefore, in this case, it is assumed that it is an erroneous signal or noise, and it is ignored and the process returns to step (3). Since the process returns to step ■ without passing through step ■, the counting of pulse signals from the proximity switch 9 continues, and if an electric signal is obtained by passing through the normal resonant circuit 5, step ■ The process proceeds to step ■ and step ■, and there is no problem in the processing of step ■. In this way, only normal signals are subject to control, and erroneous signals or electrical noise from outside the device are removed.

On the other hand, if an electric signal is not obtained at the connection terminal with the detector 6 in step (2), the process proceeds to step (2) as described above. number (Mmax + n)
Determine whether it exceeds.

Here, if the maximum count number is exceeded and a determination result of YES is obtained, the resonant circuit 5 is disconnected due to the longitudinal tear of the conveyor heald 4, and even though it passes over the detector 6, Assuming that the detector 6 does not output an electric signal, the process proceeds to step (2) to stop the operation of the conveyor belt 4 or generate a warning.

Further, in step (2) above, if the count number of the pulse signal does not exceed the maximum count number (Mmax + n) and the determination result is No, it is assumed that the buried position of the resonant circuit 5 has not yet been reached, and step (2) is performed. The conveyor belt 4 continues to operate, and each time a normal resonant circuit 5 passes, the processes of steps (1) and (2) are repeated.

In this way, according to the above embodiment device, it is determined whether or not the electrical signal is output at the position where the electrical signal should be output, with respect to the electrical signal output to the connection terminal with the detector 6,
By distinguishing and controlling normal signals from erroneous signals and noise, it is possible to eliminate malfunctions of the conveyor belt longitudinal tear detection device due to erroneous signals and noise.

In addition, in the vertical crack detection device for the conveyor belt 4 having the above configuration, even if the number of pulse signals from the proximity switch 9 exceeds the maximum count number (Mmax+n), no electrical signal is obtained from the detector 6, so the conveyor belt 4, it is effective to bury the resonant circuits 5 at equal intervals.

In addition, with the above configuration, it is possible to prevent malfunctions, and since the progress of the conveyor heald 4 is detected by the number of pulse signals generated from the proximity switch 9 due to the rotation of the slave VJ pulley 3, the conveyor belt 4 is vertically moved regardless of the speed of the conveyor belt 4. Cracks can be detected.

In the above embodiment, a detector using a resonance circuit and a change in inductance is used as an example of a combination of the object to be detected embedded in the conveyor belt 4 and the detector 6 for detecting it, but the present invention is not limited to this. (In addition, a combination of a loop coil and a detector using electromagnetic coupling,
It may also be a combination of a conductor and a detector using electrostatic coupling. Furthermore, even if the pulley rotation detected member attached to the side surface of the driven pulley 3 is combined with a pulse signal generator that responds thereto, in addition to the combination of the metal plate 8 and the proximity switch 9, a permanent magnet and a coil, or a light emitting It may be a combination of an element and a light receiving element, or a bar code and a light sensor.

〔Effect of the invention〕

The present invention is a device for detecting longitudinal cracks by embedding a detection object in a conveyor belt and using a detector installed outside the conveyor belt, and comprising: means for detecting the running distance of the conveyor belt by the number of pulses; A storage means is provided for storing the buried position of the object to be detected based on the number of pulse signals from the detection means, and when a signal from the detector is obtained, the signal is compared with the stored contents of the storage means. Since the detector is configured to include a control device that determines whether or not it is a legitimate signal based on the passage of the object to be detected, the detector can detect the magnetic material in the object to be transported or the joint of the steel cord belt. Since it is possible to reliably detect longitudinal cracks without removing signals that are not regular detection signals, such as false signals occurring in the process or electrical noise from outside the device, the reliability of the device can be greatly improved. Since the progress of the conveyor belt is detected by the number of pulse signals generated as the conveyor belt travels, there is an advantage that it is not affected by the degree of deterioration of the conveyor belt.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the configuration of an apparatus according to an embodiment of the present invention;
Fig. 2 is an enlarged view showing the configuration of the metal plate and proximity switch portion in Fig. 1, Fig. 3 is a flowchart for explaining the operation of the same embodiment device, and Fig. 4 is a diagram of a conventional conveyor belt. FIG. 5 is a schematic diagram showing the configuration of the longitudinal tear detection device, and FIG. 5 is an explanatory diagram illustrating the structure of the belt portion thereof. ■...Belt conveyor device, 2...Drive pulley,
3... Driven pulley, 4... Conhair belt, 5...
... Resonance circuit, 6... Detector, 8... Metal plate, 9.
...Proximity switch, 10...control device.

Claims (1)

[Claims] A device for detecting longitudinal cracks by embedding the object to be detected in a conveyor belt and using a detector installed outside the conveyor belt. A storage means is provided for storing the buried position of the object to be detected based on the number of pulse signals, and when a signal from the detector is obtained, it is compared with the stored contents of the storage means, and the signal is detected as the buried position of the object to be detected. 1. A conveyor belt longitudinal tear detection device, comprising: a control device for determining whether or not the signal is a regular signal based on the passage of a body.