JPH0240035Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an improvement of a conveyor belt longitudinal tear detection device.

(Prior art) Conventionally, in a conveyor belt for transporting ore, etc., when the conveyed material falls from the chute section onto the conveyor belt, foreign objects such as iron pieces mixed therein and large lumps of ore with sharp corners are detected. The object runs into the conveyor belt, moves while being held by the conveyor belt, gets caught by the carrier roller device that supports the conveyor belt from below, and then stops, tearing the continuously running and moving conveyor belt in the longitudinal direction. Vertical tearing accidents often occurred, rendering expensive belts unusable and resulting in huge losses.

Therefore, in order to solve this problem, various measures have been studied and taken, such as a device that incorporates a vertical tear detection mechanism inside the conveyor belt, and a device that detects the vertical tear phenomenon from the outside of the conveyor belt. However, due to vibrations derived from conveyor belt equipment, belt wear, wind, rain, dust, etc., conveyor belt tear detection devices often break down, deteriorate in performance, malfunction, or cause problems in installation, maintenance, etc.
Due to the complexity of maintenance or the shape of the conveyor belt, it gets in the way of inspection and maintenance and ends up being removed, making it impossible to reliably detect and prevent actual longitudinal tearing accidents. It was hot.

Therefore, in order to deal with the above-mentioned situation, the inventors of the present invention have conducted various studies for some time, and first, they have developed a method that includes conductors arranged at approximately constant pitches on the back of the belt, and the surface of the carrier roller that supports the belt. forming at least two current circuits with conductor parts provided at three or more locations isolated from each other, and detecting as an abnormality when there is no current in one of the circuits;
We proposed a vertical tear detection device configured to stop the belt in Japanese Patent Publication No. 48-9915, and as an improvement, we installed non-conductive parts before and after the conductive part on the back of the belt, and improved the characteristics of the wear-resistant cover rubber. Even in the event of a decrease in electrical resistance due to improvements in electrical resistance, we have developed a vertical tear detection device that can stabilize the energization state at the contact area between the back side of the belt and the carrier roller and prevent malfunctions.
No. 108564 (Jikkoi No. 61-25319, Jikkoi No. 1-4734
No.).

(Problems to be solved by the invention) However, in the above-mentioned proposals, the back side of the belt gets very dirty, mud adheres to the carrier roller, and the conductor part of the belt and carrier roller becomes energized. Functionality may deteriorate, and in general, small currents may flow through rubber parts under conditions such as adhesion of conductive materials or rainy weather.
The problem remains that it becomes difficult to distinguish between the energized state of the conductor part and the general rubber part, leading to a risk of malfunction.

The present invention deals with this situation and uses a method that checks whether or not conductivity is present only by the conductor part, completely ignoring changes in the general rubber part, and providing a highly sensitive discrimination function. The purpose is to further improve the detection function of

(Means for Solving the Problems) Therefore, the feature of the present invention for achieving the above-mentioned object is that in the conveyor belt having the structure according to the above-mentioned proposal, either one of the side edges of the belt conductor portion A magnetic body part is arranged side by side with the carrier roller, and a magnetic sensor is installed close to the front and rear of the carrier roller and on the side where the magnetic body part is arranged.

(Function) In the conveyor belt longitudinal tear detection device configured as described above, when the belt is running, the energizing function of the belt and the carrier roller deteriorates due to the dirt on the back side of the belt becoming severe or mud adhering to the carrier roller. Even if the carrier roller is not energized even though the passage of the conductor can be confirmed by catching the magnetic material on the side edge of the conductor embedded in the belt with a magnetic sensor, the carrier It becomes possible to confirm and treat abnormalities in the rollers or belt dirt, and thereby the subsequent detection system can be operated with high accuracy.

(Embodiments) Hereinafter, specific embodiments of the present invention will be described further based on the accompanying drawings.

1 and 2 show the arrangement of the conductor part and the magnetic part which constitute the main parts of the device of the present invention,
In these figures, 1 is a conveyor belt main body in which a tensile member 6 is embedded in a cover rubber 5, and 2 is a conductor portion arranged on the back side of the cover rubber 5 of the belt at an approximately constant pitch. It has a structure in which, for example, one or more layers of copper wire cords or thin copper plates are embedded in a conductive rubber layer, and highly insulating non-conductive parts 3 are provided before and after the conductive rubber layer, and furthermore, a conductive part 2 is provided. Magnetic body part 1 on either side edge of
0 are provided before and after the non-conductor portion 3.

Of course, this magnetic body portion 10 may be provided only at the front portion, such as at either the front or the rear.

Here, the non-conductive parts 3, 3 are made of a non-conductive rubber layer, and are provided with a required width at the front and back of the conductive part 2 in the belt length direction (arrow direction) as shown in FIG. Generally, the electrical resistance value is desirably 10 ¹⁰ Ω or more, which is higher than the air resistance value of 10 ⁶ to ^{10 8} Ω of the belt cover rubber 5, for example, the normal wear-resistant cover rubber 5.
The cover rubber 5 is colored with a rubber compound obtained by removing carbon black so as to be distinguishable from the cover rubber 5.

On the other hand, the magnetic body portion 10 is attached to the belt cover rubber 5.
It is formed by mixing a magnetic metal powder, such as barium-ferrite, into the material, vulcanizing it, and then magnetizing it.

Although the magnetic body part 10 is provided on the same back surface of the belt as the conductor part 2, it is not limited to this position, and may be provided on the belt surface corresponding to the conductor part 2.

In the figure, 4 is a detection carrier roller that supports the belt 1, and 11 is a magnetic sensor fixedly arranged close to the side where the belt magnetic body part 10 is buried near the front and back of the carrier roller, It corresponds to the magnetic body part 10 and constitutes an important element of the present invention.

Next, the carrier roller 4 in the above invention
An example of the structure of this is shown in Figures 3 to 5, and its outer periphery is made of a non-conductive material such as polyurethane rubber, and its surface has three conductive parts of an appropriate width. The above configuration is such that they are provided isolated from each other.

Of these, FIG. 3 shows the case of three carrier rollers, with two conductor parts 4a and 4 on the first roll on the left side and one place on the third roll on the right side in the figure.
If b, 4c are placed, Fig. 4 shows the first, second,
One conductor part 4a', 4b' on the third roll,
4c' is shown.

To explain the structure of the first carrier roller in FIG. 3 in more detail with reference to FIG. Annular conductor portions 4a, 4b, made of a material such as iron or copper, are arranged at predetermined positions of the tube and separated from each other, and the conductors 4a, 4
Terminals 9a and 9b are respectively brought into contact with the surface of b.

Thus, on the carrier roller 4 having the special detection function configured as described above, there is a conductive rubber 2 on the back side, a highly insulating non-conductive rubber 3 on both ends of the conductive rubber 2, and the conductive rubber 2 on the back side. When a normal belt 1 with no vertical tears, in which a magnetic rubber 10 is embedded in one of the side edges of the rubber 2, passes, a circuit in which the conductor parts 4a and 4b of the special detection carrier roller 4 serve as terminals and The circuits whose terminals are 4b and 4c are each short-circuited, and current flows through the two circuits through the conductor portion 2 in the belt.

Since each terminal is connected to a detection control circuit as shown in FIG. 6, the above case is recognized as "normal". On the other hand, if a vertical tear occurs in the belt, one of the circuits will be cut off depending on the location of the tear, and therefore, in this case, only one circuit will be energized, so this is considered an "abnormality" and the belt operation is stopped. This prevents further vertical tearing of the belt.

However, when the belt is running, if the back side of the belt becomes heavily soiled or mud adheres to the carrier roller, the energizing function of the belt and carrier roller deteriorates, sometimes interfering with the above-mentioned "normal" and "abnormal" notifications.

However, at this time, since the magnetism of the side edge of the belt conductor part is captured by a magnetic sensor,
Since the passage of the conductor can be confirmed by the operation of the magnetic sensor, if there is no energization signal to the carrier roller, it is possible to confirm that there is an abnormality in the carrier roller or the belt. can restore good accuracy.

(Effects of the invention) As described above, the present invention provides at least two current circuits by the conductor parts arranged at a constant pitch in the longitudinal direction on the back surface of the belt and the conductor part separately provided on the surface of the non-conductor carrier roller. In a conveyor belt longitudinal tear detection device that detects as an abnormality when there is no electricity in one of the belts, a magnetic body is provided on the side edge of the conductor on the back of the belt, and a magnetic sensor is installed in response to this. Since at least two current circuits are used for abnormality detection, it is highly accurate as a detection system, and accurate detection is possible. Therefore, in the past, abnormal conditions other than those that should be judged, such as dirty belts or dirty carrier rollers, could cause malfunctions. Therefore, the abnormality can be quickly dealt with, and the reliability can be greatly improved since the determination can be made only by the embedding of the conductor part.

In addition, in the device of the present invention, by arbitrarily converting the existing carrier roller and conductor part into this shape, it is very easy to do not only in one place but also in many ways.
It also has the advantage of being able to be detected at low cost, and has great practical effects.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a conveyor belt equipped with a longitudinal tear detection device according to the present invention, and Fig. 2 shows an example of the arrangement of a conductive part, a non-conducting part, and a magnetic part. A sectional view taken along line A; Figure 3 is a front view of the carrier roller used in the present invention;
The figure is a front view of a carrier roller showing another embodiment of the one shown in FIG. 3, FIG. 5 is a partially enlarged partial sectional view of the carrier roller shown in FIG. 3, and FIG. FIG. DESCRIPTION OF SYMBOLS 1...Conveyor belt, 2...Conductor part of conveyor belt, 3...Non-conductor part of conveyor belt, 4...Carrier roller, 4a, 4b, 4
c, 4a, 4b, 4c... Carrier roller conductor part, 5... Cover rubber, 10... Magnetic body part of conveyor belt, 11... Magnetic sensor.

Claims (1)

[Scope of utility model registration request] Conductive parts arranged at approximately constant pitches in the length direction on the back surface of the belt, and conductive parts arranged at three or more locations separated from each other on the surface of a carrier roller made of a non-conductive material that supports the belt. In a conveyor belt longitudinal tear detection device configured to form two current circuits, and detect as an abnormality when there is no current in either of the circuits, and stop the operation of the belt, the side of the belt conductor portion A magnetic body portion is arranged on either side of the edge, and near the front and back of the carrier roller,
A conveyor belt vertical tear detection device characterized in that a magnetic sensor is provided close to the side where the magnetic body portion is arranged.