JPS644734Y2 - - 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 conveying ore, etc., when the conveyed object falls from the chute section onto the conveyor belt, foreign objects such as iron pieces mixed in the conveyor belt and large lumps with sharp corners have been detected. of ore hits the conveyor belt, moves while being clamped by the conveyor belt, and once stops when hit by a carrier roller device that supports the conveyor belt from below, tearing the conveyor belt that is continuously operated and moving 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, the vibration derived from the conveyor belt equipment,
Due to belt wear, wind, rain, dust, etc.
The long-awaited conveyor vertical tear detection device may malfunction, degrade in performance, malfunction, be complicated to install, maintain, or maintain, or due to its shape, the conveyor device itself may need to be inspected.
We will reliably detect this in the event of an actual vertical tear accident, such as getting in the way of maintenance and eventually being removed.
It was a situation that could not be prevented.

Therefore, in response to the above-mentioned actual situation, the inventors of the present invention have repeatedly conducted various studies, and as a result, they have developed a simple,
We proposed a conveyor belt longitudinal tear detection device that can be detected at low cost and was published in Japanese Patent Publication No. 48-9915.

This device forms at least two current circuits with conductive parts arranged at approximately constant pitch on the back side of the belt, and conductive parts arranged at three or more isolated locations on the surface of the carrier roller that supports the belt. Furthermore, the system is configured so that if either one of the circuits is not energized, it is detected as an abnormality and the operation is stopped.

However, the electrical resistance value of the above-mentioned proposal has recently been lowered compared to the conventional one due to the increase in the amount of carbon black to improve the characteristics of the wear-resistant cover rubber, and it has some electrical conductivity. Therefore, the remarkable difference in conductivity between the conductive part and the non-conductive part is lost, and if a vertical tear occurs in the belt, a minute current flows from the conductive part to the non-conductive part, easily causing a malfunction when detecting a vertical tear. I found a flaw.

(Problems to be solved by the invention) The present invention focuses on the above-mentioned drawbacks, and by further improving the conductive part on the back side of the belt, the electrical resistance value is improved by improving the characteristics of the wear-resistant cover rubber. Even in the event of a drop in power, it stabilizes the energization state at the contact area between the back side of the belt and the carrier roller to prevent malfunctions, and also clarifies the position of the conductor on the back side of the belt to facilitate maintenance inspections. It is something to consider.

(Means for Solving the Problems) Therefore, the feature of the present invention that is suitable for solving the above problems is that in the conveyor belt having the structure according to the above proposal, there is a belt in particular at the front and back of the conductor portion on the back side of the belt. It has a non-conductive part with higher insulation than the cover rubber, so that a clear signal can be obtained from the conductive part when vertical tearing is detected, and the position of the conductive part is also made clear. .

Here, the electric resistance value of the above-mentioned particularly highly insulating non-conductive body portion is larger than that of the cover rubber of the belt, that is, the electric resistance value of the recent ordinary belt cover rubber is 10 ⁶ to ^{10 8} Ω. Because it is
It is desirable that the resistance is 10 ¹⁰ Ω or more, and examples thereof include rubber compounds in which carbon black is removed or reduced in size from ordinary wear-resistant cover rubber.

In order to clearly distinguish this non-conductive rubber layer from the normal cover rubber, the color is made to be different from that of the normal cover rubber.

Further, the desired effect is usually achieved by providing this non-conductive rubber layer with a predetermined width at the front and back of the conductive part in the belt length direction, but for safety reasons, it is preferable to wrap the non-conductive rubber layer around the conductive part. It is.

On the other hand, the carrier roller is made of a non-conductive material such as polyurethane rubber, and has conductive parts such as iron or copper disposed at predetermined positions and separated from each other. A terminal is placed in contact with the surface.

(Function) The vertical tear detection device for a conveyor belt constructed as described above has a belt having a conductive part on the back surface above the carrier roller and a non-conductive part with particularly high insulation buried on both sides of the conductive part. When the belt passes, at least two circuits, each of which is normally constituted by terminals in contact with the conductive parts of three or more carrier rollers, are short-circuited, and these two current circuits are connected through the conductive parts in the belt. A current will flow through.

At this time, since each terminal is coupled to the detection control device, 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, so in this case only one circuit will be energized.This is recognized as an abnormality and the known Stop belt operation based on means.

From the above results, it is essential to form two current-carrying circuits in the present invention. This is because the belt is originally made of rubber, which is the lower conductor, and in the case of only one circuit, it may be due to non-conductivity due to cutting of the conductor part buried in the belt.
This is because it is not possible to determine whether the non-conductive portion is normal (not cut) and is non-conductive. Therefore, detection using only one circuit requires a complex time relay that adds "time" to the detection circuit, as seen in the conventional technology, and detects the failure of electricity within a certain period of time as an "abnormality." . However, in the present invention, this is unnecessary.

(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 and non-conductor parts that constitute the main parts of the device of the present invention, and in these figures, 1 is the conveyor belt main body;
Reference numeral 2 denotes a conductor section arranged at a substantially constant pitch on the back side of the belt cover rubber, and is made up of a conductive rubber layer of a required width, with highly insulating non-conductor sections 3 and 3 arranged in front and behind it. ing.

The non-conductive parts 3, 3 are made of a non-conductive rubber layer, and are usually provided with a required width at the front and rear of the conductive part 2 in the belt length direction (in the direction of the arrow), as shown in Fig. 2A. Although this is sufficient, it is more desirable to wrap the conductor portion 2 as shown in FIG. 2B.

In addition, as mentioned above, the electrical resistance value of the non-conductor parts 3, 3 is the electrical resistance value of the belt cover rubber 5.
It is preferable that the resistance is 10 ¹⁰ Ω or more, which is larger than 10 ⁶ to 0 ⁸ Ω.For example, it is a rubber compound obtained by removing carbon black from a normal wear-resistant cover rubber, and is colored (for example, white) so that it can be distinguished from the cover rubber 5. It's a good idea to keep it.

In the figure, 4 indicates a carrier roller for detection that supports the belt 1, and 6 indicates a tensile member.

Next, the carrier roller used in the present invention will be explained based on FIGS. 3, 4, and 5.

The carrier roller of the present invention has its outer circumferential portion made of a non-conductive material such as polyurethane rubber, and its surface is provided with three or more conductive portions of an appropriate width separated from each other. There is.
Of these, Figure 3 shows the case of three carrier rollers, two conductor parts 4a, 4b, 4c on the first roll on the left side and one place on the third roll on the right side in the figure.
FIG. 4 shows a case in which conductor portions 4a', 4b', 4 are placed at one location on each of the first, second and third rolls.
An example in which c' is provided is shown.

In addition, if the structure of the first carrier roll in FIG. 3 is explained in more detail with reference to FIG. Annular conductor portions 4a, 4 are separated from each other at predetermined positions.
b A ring body made of a material such as iron or copper is arranged,
Terminals 9a and 9b are respectively brought into contact with the surfaces of the conductor portions 4a and 4b.

Thus, a conductive rubber 2 on the back side and a vertical conductive rubber 3 with highly insulating non-conductive rubber 3 buried at both ends of the conductive rubber 2 are placed on the carrier roller 4 having a special detection function configured as described above. When a normal belt 1 with no tears passes, the circuit whose terminals are the conductor parts 4a and 4b of the special detection carrier roller 4 and the circuit whose terminals are 4b and 4c are short-circuited, and the conductive parts in the belt are short-circuited. Current will flow through the body 2 to these two circuits.

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 in this case, only one of the circuits will be energized, so this will be considered an "abnormality" and the belt will stop operating. This prevents further vertical tearing of the belt.

(Effect of the invention) As described above, the present invention has a conductor part arranged at approximately constant pitch on the back side of the belt, a non-conductor part with particularly high insulation before and after the conductor part, and three or more places on the surface of the belt, which are arranged at approximately constant pitch. At least two or more energized circuits are formed between the carrier roller and the carrier roller, which has a conductive part to isolate it, and if one of the circuits is not energized, it is detected as an "abnormality" and the operation is stopped. Therefore, by making the pitch of the conductor parts arranged in the belt denser, vertical tearing can be detected more reliably and at an early stage, which not only has a very remarkable effect in industry, but also Even if a problem occurs in the conductor part inside, the non-conductor parts disposed before and after the conductor part have an excellent effect of making inspection easy.

What's more, if you arbitrarily convert the existing carrier roller to this trick, it has the advantage of being able to detect not just one spot but many spots very easily and inexpensively, and has great practical effects. .

Moreover, in particular, in the present invention, since the contact is made by a surface instead of the conventional point contact, it also has the advantage that the detection function can operate normally even if the belt meanders.

[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. 3 is a front view of a carrier roller used in the present invention, FIG. 4 is a front view of a carrier roller showing another embodiment of the embodiment shown in FIG. 3, and FIG. 5 is a front view of a carrier roller used in the present invention. Fig. 6 is a partially enlarged partial sectional view of the carrier roller shown in Fig. 6.
FIG. 2 is a schematic diagram illustrating an example. 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'...Conductor portion of carrier roller, 5...Cover rubber.

Claims (1)

[Scope of utility model registration request] A conductor part is arranged on the back side of the belt at approximately constant pitch in the length direction, and a non-conductor part having a particularly high insulating property compared to the belt cover rubber is arranged in front and behind the conductor part, and a carrier supporting the belt. Conductive portions are provided at three or more isolated locations on the roller surface, and at least two current circuits are formed by the conductive portions, and a case where either one of the circuits is not energized is considered an abnormality. 1. A conveyor belt vertical tear detection device, characterized in that it is configured to detect a vertical tear and stop the operation of the belt.