JPH03288712A - Detector of vertical split for conveyor belt - Google Patents

Abstract

PURPOSE:Not to detect simple cutting of only a loop coil unrelated to a vertical split accident by constituting the aforementioned loop coil with a standard loop coil specifically related to a usual loop coil, devising a cut detection means to transmit an output signal except for the usual loop coil when a cut-off loop coil is detected by a detection antenna. CONSTITUTION:Contact and separation of a usual coil or a standard loop coil with and from detection antennas 51, 52 is sequentially input to MPU 75 as two sets of pulses through a conversion part 6 and others. The MPU 75 sends a signal to RAM 77 and sequentially addresses the usual loop coils equivalent to the pulses sequentially input. It judges whether to simply cut off a usual loop coil 31a and others by way of comparing them with an address 'NOx' having an information of a release '1' memorized in RAM 77. At the time of NO, MPU 75 outputs a warning from an alarm through PIO 73. A conveyor belt 2 stops through a driver 74. Then, an operator confirms whether there is a vertical split 8 on the conveyor belt 2 or not.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a conveyor belt vertical tearing device.

[Prior Art] Conveyor belts used in blast furnaces, port cargo handling, mines, etc. transport heavy materials such as ore, so once a crack occurs due to repeated loads, the conveyor belt immediately splits vertically in the longitudinal direction. It becomes and spreads. If a conveyor belt with such longitudinal tearing is continuously used, the longitudinal tearing will progress further, making it impossible to convey objects, and requiring a great deal of expense to renew or replace the conveyor belt.

Conventionally, a device described in Japanese Patent Publication No. 49106/1983 is known as a device for detecting such longitudinal tearing of a conveyor belt. This detection device consists of a set of two loop coils buried at a constant pitch along the entire length of the conveyor belt, and a position corresponding to the loop coil at the bottom of the conveyor belt. The control means includes two detecting antennas that can be coupled together, and a disconnection detecting means for detecting disconnection of the loop coil based on a change in the inductance of the detecting antenna due to the approach of the loop coil.

In this detection device, a logic circuit serving as a control means converts the inductance change caused by the cutting of the loop coil into an electric signal, and determines whether a vertical tear has occurred in the conveyor belt based on the presence or absence of this electric signal. In other words, if a vertical tear occurs in the conveyor belt, the loop coil will also be cut at that part, and the detection antenna will not cause an inductance change in the loop coil. If the cut detection means detects an electric signal from the pair of loop coils, it is determined that the conveyor belt is normal; if the cut detection means detects only one electric signal from the pair of loop coils, it is determined that the conveyor belt is abnormal, and an alarm is issued in the case of an abnormality. emanate. This warning allows the driver to
The conveyor belt can be stopped.

[Problems to be Solved by the Invention] However, the conveyor belt vertical tear detection device may issue an alarm even if no vertical tear has occurred in the conveyor belt. However, this detection device only determines that the conveyor belt is abnormal when there is only an electrical signal from one of the pair of loop coils, and it is not possible to determine whether one of the loop coils is abnormal due to local wear of the conveyor belt, etc. If the conveyor belt is cut, it will always be judged as abnormal even if there is no vertical tear in the conveyor belt.

In this case, a time-consuming work is required to connect the cut portion of the loop coil. Naturally, the conveyor system must be stopped during the connection, resulting in a shutdown of the associated equipment in which the conveyor bell is used. In order to avoid a long stoppage of the entire device, if the operator confirms that there is no vertical tear in the conveyor belt and that the loop coil is simply broken, the operator must not stop the conveyor belt and connect the loop coil. The conveyor belt may be activated again without having to be restarted. In such a case,
With conventional detection devices, an alarm is issued every time a disconnected loop coil approaches the detection antenna.
When the alarm is issued twice in a row, the driver is likely to judge that the conveyor belt has truly vertically torn and stop the conveyor belts 1 to 1. In such a case, the conveyor belt has a vertical tear extending over two consecutive loop coils, which requires a great deal of expense for repair and accident resolution.

The present invention has been made in view of the above-mentioned conventional circumstances, and is a conveyor belt vertical tear detection device that can prevent in advance the detection of conveyor belt abnormalities due to mere disconnection of loop coils that are unrelated to vertical tear accidents. The purpose is to provide

[Means for Solving the Problems] The conveyor belt vertical tear detection device of the present invention includes a plurality of loop coils disposed on a conveyor belt rotated by a drive unit, and a plurality of loop coils facing the back side of the conveyor belt. , has a detection antenna that can be inductively coupled to one of the loop coils in sequence as the conveyor belt moves, and a disconnection detection means that detects disconnection of the loop coil based on a change in inductance of the detection antenna due to the approach of each loop coil. A vertical tear detection device for a conveyor belt, comprising a control means, wherein the loop coil has a plurality of normal loops arranged at a predetermined pitch in the longitudinal direction of the conveyor belt and which can be cut by a longitudinal tear of the conveyor belt. ], and a reference loop coil that is in a predetermined relationship with the normal loop coil, and the control means includes, in addition to the disconnection detection means, a reference loop coil detection unit that identifies the reference loop coil from the normal loop coil. storage means for storing array data of each of the normal loop coils based on the received signal of the normal loop coils based on the input of the reference loop coil detection means; and normal storage means for excluding at least one of the data in the storage means. loop coil exclusion input means, and the disconnection detection means excludes the normal loop coil and outputs an output signal.

For example, the reference loop coil may be disposed at a position different from the pitch of the normal loop coil, or may be of a different shape or material than the normal loop coil. If the reference loop coil is arranged at a pitch different from that of the normal loop coil, the reference loop coil can be detected by a periodic change in the signal. If the reference loop coil has a different shape or material from the normal loop coil, the reference loop coil is detected based on the signal level.

There may be a plurality of reference loop coils.

[Operation] The disconnection detection means converts the inductance change that occurs between the detection antenna and the normal loop coil and the reference loop coil into an electrical signal. At this time, since the reference loop coil has a predetermined relationship with the normal loop coil, there is a difference in inductance change between the normal loop coil and the reference loop coil as the conveyor belt rotates. The reference loop coil detection means identifies the reference loop coil from the normal loop coil based on the type of signal caused by this difference in inductance change. The storage means stores the array data of each normal loop coil based on the received signal of the normal loop coil based on the input from the reference loop coil detection means. The normal loop coil exclusion input means excludes at least one of the data in the storage means.

Therefore, in the case where only a loop coil is cut without longitudinal tearing of the conveyor belt, the cutting of the loop coil is stored in the storage means, and the conveyor belt can be continuously operated. Thereafter, the conveyor belt rotates and the loop coil being cut is detected by the detection antenna, but since it matches the data in the storage means, the cut detection means normally excludes the loop coil and outputs an output signal.

[Example] Hereinafter, an example embodying the present invention will be described with reference to the drawings.

As shown in FIG. 1, this conveyor belt longitudinal tear detection device includes a loop coil 3 embedded in a conveyor belt 2 for conveyance which is rotated in the direction of the arrow in the figure by a drive unit 1;
Detection antenna 51 facing the back side of the conveyor belt 2.
52 and each sensing antenna 51.5 as shown in FIG.
2 and connected control means 6.7.

As shown in FIG. 1, the loop coil 3 includes a plurality of pairs of normal loop coils 31a, 328, etc., and a pair of reference loop coils 41, 42.

Usually, the loop coils 31a, 32a, etc. are made of a magnetic material that can be cut by the vertical tear 8 of the conveyor belt 2,
They are buried at a predetermined pitch L in the longitudinal direction of the conveyor belt 2. These normal loop coils 31a, 32a, etc. are connected to the detection antenna 4 by conductive wires (not shown) buried in the conveyor belt 2 to maintain strength.
1.42 are embedded in pairs in the width direction of the conveyor belt 2 to prevent irregular inductance changes. That is, on one side of the conveyor belt 2 in the width direction, there are normally loop coils 31a and 31b.

31C (hereinafter referred to as 1ch normal coils 31), etc. are buried, and on the other side in the width direction of the conveyor belt 2, normal loop coils 32a, 32b, 32c, etc. (hereinafter referred to as 1ch normal coils 31) are buried.
These are called 2Ch normal coils 32. ) is buried. In addition, the normal loop coils 31a and 32 for each multiple pair
8 etc., for example, the normal loop coils 31b and 32b are different from the normal loop coils 31a and 32a so that even if a vertical tear 8 occurs between adjacent normal loop coils 31a and 32a, the vertical tear 8 can be detected. The length in the width direction is different. Further, addresses of the lch normal coil 31 and the 2ch normal coil 32 are predetermined in order of the conveyance direction of the conveyor belt 2 with reference to the reference loop coil 41 and 42, and these addresses are added to the conveyor belt 2. . In this embodiment, the normal loop coils 31a and 32a are No. 1.

0 1", normal loop coils 31d and 32d are "N094"
It is stipulated that

The reference loop coils 41 and 42 are also the normal loop coils 31a.
, 328, and the like.

These reference loop coils 41, 42 are buried in positions different from the positions where the Luer coils 31a, 328, etc. are normally disposed. In this embodiment, the reference loop coil 4L is spaced apart from the normal loop coils 31b and 32b immediately before the conveyance direction.
42 are buried. In addition, the reference loop coil 41
is 1Ch normal coil 31 side, reference loop coil 42 is 2
channel normal] is buried on the side of the file 32.

In this embodiment, the detection antennas 51, 52 are connected to the control means 6.
．． The camera employs an oscillation circuit in which an alternating current voltage of a constant frequency is supplied from an oscillation circuit of 7. The detection antennas 51 and 52 are opposed to the back side of the conveyor belt 2, and the detection antennas 51 are connected to the 1ch coil 31 and the reference loop coil 41.
The detection antenna 52 is sequentially inductively coupled to the 2ch normal coil 32 and the reference loop coil 42. That is, these detection antennas 51 and 52 generate a magnetic field in the loop coil 3 when the loop coil 3 approaches, and a voltage change is caused by electromagnetic induction caused by this magnetic field. Therefore, if there is a disconnection in any of the 1ch normal coils 31, no voltage change will occur in the detection antenna 51, and if any of the 2ch normal coils 32 is disconnected, the detection antenna 52 will not change. No voltage change occurs.

The control means 6.7 includes a cutting detection means 6 and a cutting detection means 6.
and a microcomputer 7 connected to the drive section 1.

The disconnection detection means 6 includes an oscillation circuit, a detection circuit, and an L
Consisting of a PF (low-pass filter) and an A/D converter. As shown in FIG.
Illu 31.2ch Normal coil 32 and reference coil 4L
The voltage changes of each of the detection antennas 51 and 52 due to the approach of 42 are treated as a set of two pulses. conveyor belt 2
When the detection antenna 51.52 rotates, the detection antenna 51.52 repeatedly approaches and separates from either the 1st, 2nd, or 2nd channel coil 31.32 or the reference loop coil 41.42, so such pulses are periodically repeated. The output side of this conversion section 6 is connected to a microcomputer 7.

The microcomputer 7 includes a PLL (pulse detection logic) 71 connected to the disconnection detection means 6, a digital switch 72 for inputting data from the driver, and a PIO (parallel input/output) input from the PLL 71 and the digital switch 72. 7
3, a driver 74 output from this PIO 73,
MP with a clock and a signal output from PIO73
U (microprocessing unit) 75 and MP
It consists of a ROM 76 that sends programs to the U 75, and a battery-backed RAM 77 that constitutes storage means. The MPtJ 75 constitutes a reference loop coil detection means and a normal loop coil exclusion input means. In the RAM 77, information on the addresses rNO, *j for each of the 1.2ch normal] files 3L3'2 and information on the release "1" or non-release rOJ for each are stored manually. Further, an alarm (not shown) is connected to the PIO 73. Furthermore, the driver 74 has a driving section 1.
or connected.

Next, the operation of this detection device will be explained.

First, after confirming that the conveyor belt 2 is conveying at a constant speed, the driver turns on a main switch (not shown). Thereby, this detection device performs various initializations in step S1, as shown in FIG. After this, the driver pitches, pitches the distance p and the conveyor bell 1
The conveying speed V of ~ is input from the digital switch 72.

Also, at this time, the driver
etc., the address r of the normal loop coil that has already been cut.
For No. *J, reset “1” to the digital switch 72.
Enter from.

Thereafter, by turning on the start key (not shown) of this detection device, the scheduled period T of pulses by the 1.2Ch normal coil 3L 32 is calculated from the pitch L and the conveyance speed V in step S2. Further, from the interval ρ and the conveyance speed V, the scheduled period t of pulses generated by the reference loop coil 41, 42 is calculated. Then, as the conveyor belt 2 rotates, the 1ch
Normal] Either one of the 2-channel normal coils 31 or the reference loop coil 41 approaches and isolates the detection antenna 51, and one of the 2-channel normal coils 32 or the reference loop coil 42 approaches and isolates the detection antenna 52. As shown in FIG. 4, two sets of pulses are sequentially input to the MPU 75 from the detection antennas 51 and 52 via the converter 6 and the like.

Then, in step S3 shown in FIG. 3, it is determined whether or not two sets of pulses are input, and if YES, the process advances to step S4. If no, 8 pairs of loop coils 3
It is determined that the detection antennas 41 and 42 are present between the two, and the process returns to step S3.

After this, in step S4, the time difference X between the two sets of input pulses is calculated. Then, in step S5, T-Δ<X<T0 (Δ is the error range, however, T-Δ=
It must not be t. ), and if YES, the loop coil 3 that approached the detection antenna 51.525 last is the reference loop coil 41.4.
It is determined that it is not 2, and the process proceeds to step S7 to execute the timer mode. If No, standard loop coil 41.4
2, and the process proceeds to step S6 to execute the coil set mode.

In step S6, the coil set mode flag is turned on. As a result, the MPU 75 sends a signal to the RAM 77, and the normal loop coil corresponding to the previous pulse receives rNo,
* Number J. Thereafter, addresses are sequentially assigned to the normal loop coils corresponding to the input pulses.

Further, the coil set mode is clearly indicated by sending a signal to an LED (not shown).

Thereafter, in step S8, the time difference X between the two sets of pulses that are sequentially input is eliminated. In step S9, for X which is not equal to t, it is determined whether T - Δ x O
Turn on the K flag. As a result, the MPU 75 sends a signal to 16 ED (not shown) to display that the conveyor belt 2 is normal. Then, the process returns to step S8, and the above processing is continued until the driver turns off the main switch. If No in step S9, it is determined that the normal loop coil corresponding to the previous pulse is abnormal, and the process proceeds to step S10.

In step 810, the MPU 75 compares the address rNo, *J that the MPU 75 intends to assign to the RAM 77 with the address rNo, *j already stored in the RAM 77 and having the information of release "1". If YES, it is assumed that this normal loop coil should be canceled, and the process proceeds to step 311, sets the OK flag ONL, and returns to step S8. Therefore, in this detection device, when the conveyor belt 2 is simply cut, such as the normal loop coil 31a, without longitudinal tear 8, the conveyor belt 2 continues to rotate, and the cut normal loop coil is cut. Re-detection antenna 5
1.52, no alarm will be issued.

7 If No in step 810, it is assumed that this normal loop coil should not be released, and the process proceeds to step 312, where the NG flag is turned on. As a result, M
The PU 75 outputs an alarm via the PIO 73. Furthermore, in this embodiment, when the NG flag is turned on, a stop signal is sent to the drive unit 1 via the driver 74, so the conveyor belt 2 is stopped. Then, the driver checks whether there is a vertical tear 8 in the conveyor belt 2 or not. If there is no vertical tear 8 and it is just a cut of a normal loop coil that is different from the one you have already input, cancel ``1'' for the address ``NO9*'' of the normal loop coil written at that position.
” is input from the digital switch 72. Thereafter, the start key of this detection device is turned on to start the conveyor belt 2 again. After this, in this detection device, even if the conveyor belt 2 rotates and its normal loop coil is detected again by the detection antennas 51, 52, no alarm is issued.

In addition, if a vertical tear 8 occurs, repair work will be performed as necessary, but since this vertical tear 8 is caused by one normal loop coil 31a etc., the length is short. , can be covered with minimal repairs and accident handling.

In step S7, the timer mode flag is turned on. Thereby, the MPU 75 clearly indicates that it is in the normal timer mode by sending a signal to an LED (not shown).

Thereafter, in step S13, the time difference X between the two sets of pulses that are sequentially input is calculated. In step S14, T
Determine -Δ<X<T+Δ, and if YES, determine that the normal loop coil corresponding to the previous pulse is normal,
Proceed to step S15 and turn on the OK flag.

Thereby, the MPU 75 sends a signal to an LED (not shown) to display that the conveyor belt 2 is normal. Then, the process returns to step S5. If No in step 314, it is determined that the normal loop coil corresponding to the previous pulse is abnormal, and step 81
Proceed to step 2 and turn on the NG flag.

In this way, if this detection device is employed, it is only necessary to connect the broken portion of the loop coil 3 according to the address marked on the conveyor belt 2 when there is time such as after the end of the operation. Moreover, if such work is not performed, the release input may be performed at the next start of operation.

In the above embodiment, pairs of loop coils 3 are used, but if a conveyor belt in which conductive wires are not embedded is used, a single loop coil can be used.

[Effects of the Invention] As detailed above, in the conveyor belt longitudinal tear detection device of the present invention, each loop coil can be identified individually, so it is possible to identify only a simple loop coil unrelated to a longitudinal tear accident. Detection of abnormalities in the conveyor belt due to cutting can be avoided in advance.

Therefore, in the case of simply cutting a loop coil and causing a vertical tear in the conveyor belt, the conveyor belt can be continuously operated without reconnecting the loop coil in order to avoid a long stoppage of the entire device. Even if a vertical tear in the conveyor belt occurs, it is possible to accurately detect a vertical tear in the conveyor belt, and the cost of repair and accident handling can be minimized.

[Brief explanation of the drawing]

1 to 4 relate to embodiments of the present invention, in which FIG. 1 is a schematic perspective view showing a part of a vertical tear detection device for a conveyor belt, and FIG.
The figures are a block diagram of the control section, a flowchart in Figure 3, and a flowchart in Figure 4.
The figure shows the time chart of the control section. 1... Drive unit 2... Conveyor belt 3...
・Loop coils 31a, 328, etc...Normal loop coils 41.42・
...Reference loop coil 51.52...Detection antenna 6...Disconnection detection means 7...Microcomputer 8...
・Vertical tear

Claims (1)

[Claims] (1) A plurality of loop coils disposed on a conveyor belt rotated by a drive unit face the back side of the conveyor belt, and are sequentially inductively coupled to one of the loop coils as the conveyor belt moves. A vertical tear detection device for a conveyor belt, comprising: a vertical tear detection antenna; and a control means having a cut detection means for detecting breakage of the loop coil by a change in inductance of the detection antenna due to a change in the inductance of the detection antenna due to the approach of each of the loop coils, The loop coil includes a plurality of normal loop coils that are arranged at a predetermined pitch in the longitudinal direction of the conveyor belt and can be cut by vertically tearing the conveyor belt, and a reference loop coil that is in a predetermined relationship with the normal loop coil. In addition to the disconnection detection means, the control means includes a reference loop coil detection means for identifying the reference loop coil from the normal loop coil, and a reception signal of the normal loop coil based on the input of the reference loop coil detection means. storage means for storing the array data of each of the normal loop coils based on the above, and normal loop coil exclusion input means for excluding at least one of the data in the storage means, and the disconnection detection means is configured to A vertical tear detection device for a conveyor belt, characterized in that it outputs an output signal by excluding