DE19715703A1 - Inductive monitoring element especially for conveyor belt - Google Patents

Abstract

In the production of an inductive monitoring element in the form of a polygonal electrically conductive textile material frame which transmits or emits electromagnetic radiation for monitoring conveyor belts, the frame (8) is produced by a textile process such as weaving or knitting from conductive wires, braids, cables, strips or the like. Also claimed is a monitoring element produced by the above method.

Description

The patent application relates to elements made of electrically conductive, band-shaped materials in textile design, for the purpose of transmission or radiation of electromagnetic energy gie, for the monitoring of elastomeric conveying or storage facilities, in particular of Conveyor belts, can be accommodated in these.

Inductive methods are known for monitoring elastomeric conveyor belts using electromagnetic signal transmission from a fixed transmitter through elements that are housed in the conveyor belt so act on a fixed receiver that at Influencing this element as a result of physical effects an evaluation of the change th receiver signal, if necessary, for immediate stopping of the conveyor belt in question can lead, for example, to avoid major damage to it. This inductive connectable elements are prepared by hand in the form of wires, strands or ropes, that they form an electrically effective ring.

In the past there were no suggestions for the organization of a company secure monitoring element in the form of a short-circuit ring, which is also used as a conductor loop is missing.

In DE-PS 19 19 327 details are given. According to the invention a flexible core is provided, which consists of a series of threads made of a material such as polyester, Nylon, glass fibers etc. is intertwined and around which an electrical conductor consisting of a wire or foil is wound from a copper alloy. In addition, another Covering layer, which is also made of polyester, nylon or glass fibers in the form of a web or as Fabric can be applied. The covering layer surrounding the conductor has the Task to prevent corrosion of the conductor made of a copper alloy.

However, it has been shown in practice that a web around the conductor or the Head of tubular surrounding tissue is neither able to manufacture the conveyor belts the pressure of the rubber to be vulcanized a sufficient tightness, Transport process by constant walking and loading by large chunks sufficient To oppose resilience. The result is a chemical disintegration process Copper alloy, which due to the free sulfur in the rubber of the För dergurtes triggered and after sufficient exposure time an electrically non-conductive Product created and thus destroyed the conductor loop.

DE-AS 1 940 945 describes a device in which the conductor material is in the form of a Strand is freely movable in a cavity of a molded rubber piece. The strand will with a rubber material that contains neither sulfur nor accelerator and therefore not can be vulcanized, encased. Due to the free mobility of the conductor material in one plastically filled cavity prevents contact with vulcanized rubber, however, the strands become stranded by the movements during the operation of such a conveyor belt slowly rubbed.  

DE-OS 20 30 796 strikes a conductor loop made of brass, zinc or the like and endlessly closed steel wire cable. Because of the connection of the Steel wire cable ends at these points problems caused by bending fractures, becomes To solve this problem proposed the ends of the elements forming the cable such as strands or ropes to let out in stages. For a cable that e.g. B. seven ropes with fourteen Has seven ends for the formation of a conductor loop. In a Another embodiment suggests endless splicing of the ropes and the respective ones Hide rope ends in the rope assembly. This type of conductor loop has been used in practice not proven because the contacting of the respective rope ends to each other or with the remaining ropes are infiltrated by the doughy rubber during the vulcanization of the conveyor belt. In addition, there is also a long-term effect of the free one required during vulcanization Sulfur in the rubber of the conveyor belt is triggered and after a sufficient exposure time electrically non-conductive contact point is generated, making the conductor loop unusable.

DE-OS 22 46 137 describes one in a three-stage twisting process from copper wire-made conductor loop, the copper wires according to subclaim 4 with a through Dip applied tin coating or (sub-claim 5) galvanically with a brass coating are provided. Splice is specified as the connection technique. The disadvantage of this teaching As with the teachings evaluated above, lies in the fact that through walking and impact stress each coating on the conductor in at least one, however small, is damaged and thus the reaction of the copper with the free in the conveyor belt Exposed to sulfur. As practice has shown, this leads to the failure of the conductor loop. In addition, a conductor loop, as indicated by way of example, with 651 wires and one Outside diameter of about 2.3 mm only in conveyor belts with an exceptionally thick Place a rubber layer.

To the when using cables or cable-like constructions the creating conductor loop as a critical connection technology to be classified splice connection To enable more stable electrical contacts is proposed in DE-OS 22 46 139, the Lead out long splices laterally and twist them together and if necessary. retrospectively the to provide the entire conductor loop thus formed with a brass coating. This too Construction can withstand the special chemical and dynamic conditions in one Conveyor belt is not fair, because the above chemical process also takes effect here. Additional forces act on the side, against the direction of force of the spliced rope lead out drill connection unfavorably and leads at the exit of the drill connection from the Cable connection to permanent breaks. The twisted strand ends are also used in the vulcanization process infiltrated by the doughy rubber.

DE-OS 28 29 933 suggests metallic staple fibers for the formation of a conductor loop before, which were previously spun into threads, the staple fibers being made of extremely short fine Metal fibers exist. The endless closure is done by knotting. Since it is the necessary power line along the staple fibers by many thousand times contacting the Fibers with their neighboring fibers, it is easy to see that the previously applicable made chemical and dynamic problems, as well as infiltration of contacts by  Large amounts of rubber occur and render the conductor loop ineffective. Make knots the worst contact and do not protect against infiltration. The goal of Creation of an inexpensive element is purchased with a construction that is questionable for the company.

DE-OS 39 27 746 wants the disadvantages listed in the aforementioned patents thereby avoid that in the endless connection of a metal cable to be connected individually Strand ends arranged next to each other without force and over a length of a few millimeters are softly soldered to each other, with the stranded ends so connected so close to the rope ensure that one of the strands retains its original position in the rope bond. Although this experience has shown that new teaching leads to reliable equipment, the disadvantage is its liability that this construction is not suitable for mechanized or automated production, since the rope assembly must first be prepared by manual splicing, the one carefully assigning the ends of the strands and inserting them by hand a total of seven out of fourteen wire ends to be connected must happen. It can be seen that these processes are time-consuming and therefore very cost-intensive.

A new teaching DE 196 01 899 relates to conductor loops which consist of an electrically conductive Foil which, according to the characteristics of other subsidiary claims, is endless and extremely thin held material between 20 microns and 200 microns are made. The disadvantage of this teaching lies in the lack of strength against the impact of sharp-edged materials that a Impacts in the area of the conveyor belt are expected. As for the stretch in normal operation by changing the trough of the conveyor belt and constant bending in the area of the support rollers and Concerning the deflection drums, it is to be expected that despite one in a subsidiary claim Proposed spiral no higher elongation occurs because the lateral mobility is not in can increase to the same extent.

In an older, unpublished application DE 196 52 236.6 a method is described for the production of monitoring elements for conveyor belts described in detail by the Manufacture of the inductively connectable rings in a special weaving process makes. Although this method is the goal of mechanized or automated manufacturing achieved, then special weaving elements have to be made for each special conveyor belt width.

The object of the present invention is to avoid the aforementioned disadvantages and a comparatively inexpensive monitoring element for installation in elastomers Funding facilities, e.g. B. Conveyor belts in mechanical, automatic production with high to create dynamic strength and flexibility.

According to the invention, monitoring elements, e.g. B. for the message Belt damage, sections, connections, temperatures, wear or the like from that they can be produced in the textile manufacturing process, such as weaving, knitting, or the like are. For example made of steel, brass or other metals inert in rubber compounds or other electrically conductive materials in the form of wires, tapes, strands or ropes existing elements can optionally be combined with further conductive or non-conductive elements, consisting z. B. from ribbons, fibers, strands or ropes or the like. So brought into a texture be that a continuous border or a band with several side by side  Borders are created. Bands made from the aforementioned materials can also be omitted Cut out a previously made wider textured surface into strips.

A border, a wide border or a band made in this way becomes another Manufacturing process a polygon, preferably a rectangle formed that the one Monitoring element electrical requirements are sufficient. It usually does a closed rectangle will be executed. But it can also be used at any point Connection of other electrical components must be open.

When a wide border with several adjacent, isolated from each other Borders are used, so you are able to close these individual borders close or by connecting the respective borders isolated from each other to achieve higher inductance compared to a single closed rectangle.

It is often advantageous if the inductance is based on the new teaching method produced monitoring elements compared to the series connection thereby increased is when a composite material of ferrite and plastic in the magnetic field of the Monitoring element is arranged.

In a further embodiment, border-like strips made of woven conductive fabric can be used capable texture separate, which like the aforementioned borders to monitoring elements are processed.

In cases where, for storage reasons, standardized dimensions of borders or The monitoring elements to be created can also bring advantages from tapes a piece of borders or ribbons that are arranged one behind the other.

To in all the aforementioned cases at the connection points of the conductive elements To obtain a permanent electrical connection, this can be done by soldering, welding or in Connected with known mechanical or chemical connection techniques who the.

The invention is illustrated by the schematic representations. It shows

Fig. 1 shows the section of a continuously manufactured, for. B. woven border, which consists of conductive warp and for mechanical stabilization of non-conductive weft elements for the purpose of electrical conductivity,

Fig. 2 shows a wider, z. B. woven border, which has a plurality of parallel, conductive areas or a cut out of a larger weave strip and

Fig. 3 is a right corner-shaped monitoring element produced by folding a single border or a strip.

The new monitoring elements according to the invention in a textile production method for the application z. B. in conveyor belts for the purpose of the aforementioned tasks are below explained in more detail by way of example.

Fig. 1 shows a portion of such a border 3, which is produced for example by weaving of electrically conductive warp elements 1, non-conductive warp elements 2 and non-conductive shots 4 or a cut out from a larger web surface stripe or texture produced in another textile manufacturing process. However, conductive shots can also be used.

Fig. 2 shows a modification to a wider border 5, alternately between a plurality of conductive warp elements 1 has some non-conductive warp 2. After the production of this border, it is possible to use it to produce monitoring elements or to form several narrow borders for the production of monitoring elements from the wide border 5 by separating the non-conductive elements 4 in the area of the elements 2 .

Fig. 3 shows an example of the preparation of a monitoring element in the form of a closed rectangular electrically conductive frame 8, made of a narrow border 3. For this purpose, the border can be folded through 90 angular degrees on three sides 6 of the rectangle to be formed, while at the two ends of the border an electrical connection 7 is established between them, thus creating an endlessly closed monitoring element. Optionally, the border 3 can be deflected in an arc at the deflection points 6 .

Reference list

1

Conductive chain element

2nd

Non-conductive chain element

3rd

Border, ribbon or stripe

4th

Non-conductive weft element

5

Wide border

6

Deflection point

7

Electrical connection

8th

Inductively effective frame

Claims (6)

1. A method for producing inductive monitoring elements, made of electrically conductive textile material in the form of a polygonal frame for the transmission or radiation of electromagnetic energy for the purpose of monitoring conveyor belts, characterized in that the frame ( 8 ) in textile technology, such as knitting, Knitting or the like. Made from conductive wires, strands, ropes, tapes or the like. 2. Monitoring elements according to claim 1, characterized in that the frame ( 8 ) made of strip-shaped material which is made in textile technology, such as weaving, knitting, knitting or the like. In the design as a border or strip ( 3 ) or wide border ( 5th ), is designed so that these are bent, bent or deflected at the frame corners ( 6 ) and electrically connected at their ends ( 7 ). 3. Monitoring elements according to claim 1 and 2, characterized in that the ends of the strip-shaped material for the frame to be produced ( 8 ) are not connected to each other, but are ruled out to electrical components or assemblies. 4. Monitoring elements according to claim 1 and 2 or 3, characterized in that the frame to be produced ( 8 ) is composed of more than one strip ( 3 ). 5. Monitoring elements according to claims 1 and 2, 3 or 4, characterized in that a plurality of frames ( 8 ) are connected so that the inductance of the monitoring element thus created increases. 6. Monitoring elements according to one of claims 2, 3, 4 or 5, characterized in that the inductance of the frame ( 8 ) by ferrite, preferably in a flexible form, is increased.