System and method for monitoring modular conveyor belts

Abstract

A system and method arranged for monitoring modular conveyor belts. The modular conveyer belt comprises a plurality of modules made from a plastic material and linked together to form a continuous path operated by a gear which in turn comprises a shaft. The system further comprises at least two sensors in such a way that a first sensor is configured for detecting the passage of reference element in the drive shaft, and at least a second sensor which is configured for detecting the passage of two consecutive reference elements inserted in the longitudinal edges of the modules.

Claims

1. A system for monitoring modular conveyor belts which comprises: a modular conveyor belt comprising a plurality of modules made from a plastic material and linked together to form a continuous path operated by a gear which in turn comprises a shaft; and at least two passages detecting apparatus; wherein the modules have inserted in their longitudinal edges a plurality of first reference elements, at least one first reference element per module; and wherein the first reference elements are placed equidistant from one another along the entire modular conveyor belt; the first passage detecting apparatus comprises a first passage detection sensor to detect the passage of two consecutive first reference elements inserted in the longitudinal edges of the modules, wherein said passage corresponds with the passage between a teeth of the gear driving the modular conveyor belt; the second passage detecting apparatus comprises at least a second passage detection sensor to detect the passage of a second reference element housed in a cottered drive shaft; and wherein the second passage detection sensor is fixed to a casing coupled at one end of the shaft on which the gear is also coupled; and wherein the output signal of the second passage detection sensor is connected with a signal processing circuit placed inside the first passage detecting apparatus in such a way that the second passage detecting apparatus is further arranged to detect the time of passage of the second reference element of the drive shaft to calculate the linear speed of the modular belt.

2. The system according to claim 1 comprising a temperature sensor arranged in a position close to the modular conveyor belt and the gear.

3. The system according to claim 1, wherein the first apparatus comprises a casing.

4. The system according to claim 3, wherein the casing houses two sensors, one passage detection sensor and another temperature sensor; and wherein said sensors are connected with a signal processing circuit.

5. The system according to claim 1, wherein the casing is suitably fixed to the rotating shaft by means of the coupling thereof with a bearing.

6. The system according to claim 4 wherein the signal processing circuit comprises at least one processor, a memory, a communications receiver-emitter, and a program or programs, wherein the program or programs are stored in the memory and configured for being run by means of the processor, and wherein the programs include instructions for: (a) conditioning the signals of the first apparatus and the second apparatus; (b) calculating detection times (T.sub.V and T.sub.P) between reference elements and measuring a temperature signal (T.sub.A) by means of a temperature sensor; and (c) delivering the detection times (T.sub.V and T.sub.P) between reference elements and the measurement of the temperature (T.sub.A) to an external server.

7. The system according to claim 6, wherein the temperature sensor, the first passage detection sensor of the first apparatus, and the second passage detection sensor of the second apparatus is a sensor selected from inductive sensors, capacitive sensors, magnetic sensors, laser sensors, infrared sensors, optical sensors, colour sensors, radiofrequency sensors, ultrasound sensors, or any combination thereof.

8. A method for monitoring modular conveyor belts implemented in a system according to claim 1 comprising: a modular conveyor belt with a plurality of modules made from a plastic material and linked together to form a continuous path operated by a gear which in turn comprises a shaft; wherein the method further comprises the steps of: (a) a signal measurement step which in turn comprises: (i) calculating the time of consecutive passage (T.sub.V) of the second reference element housed in a cottered drive shaft of the gear by means of the second passage detection sensor; (ii) calculating the time of passage (T.sub.P) between two consecutive first reference elements inserted in the longitudinal edges of the modules of the modular belt by means of a second first passage detection sensor wherein said passage corresponds with the passage between the teeth of the gear driving the modular conveyor belt; and (iii) measuring the temperature (T.sub.A); (b) a delivery step for delivering the detection time of the second reference element (T.sub.V), the detection time between two consecutive first reference elements (T.sub.P), and temperature (T.sub.A) to an external server; and (c) processing the signals (T.sub.A, T.sub.V and T.sub.P) received in step (b) in the external server, and calculating the speed of the modular belt and the elongation of at least one module of the modular belt; (d) instantly showing all the information relating to the state and prevention of the conveyor belt, on a platform accessible from any mobile and/or fixed device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A series of drawings which help to better understand the invention and are expressly related to an embodiment of said invention presented as a non-limiting example thereof is very briefly described below.

(2) FIG. 1 shows a schematized view of a modular conveyor belt implementing the system object of the present invention.

(3) FIG. 2 shows an exploded view of the passage detecting apparatus (3) for detecting the passage of the conveyor belt (1) of FIG. 1.

(4) FIG. 3 shows a plan view of the passage detecting apparatus (3) for detecting the passage of the conveyor belt (1) of FIG. 1.

(5) FIG. 4 shows an exploded view of the passage detecting apparatus (3) for detecting the passage of the shaft (21) of the gear (2) of the modular belt (1) of FIG. 1.

DISCLOSURE OF A DETAILED EMBODIMENT OF THE INVENTION

(6) As indicated above, the object of the present invention is to create a control system in conveyor belts 1 for providing immediate information about their behavior during operation. To that end, the present invention proposes measuring certain specific times for calculating the passage of the conveyor belt 1 when it is in operation for the purpose of assessing the modifications that have occurred and acting accordingly. “Passage” is understood as a reference between two repeating consecutive points equidistant from one another along the entire conveyor belt 1, where this reference is a distance which in turn corresponds with the passage between the teeth of the gear 2 driving the modular conveyor belt 1.

(7) Referring to the attached drawings, the system of the invention is configured in a modular conveyor belt 1 which comprises a plurality of plastic modules (11, 11′, 11″, 11′″, 11″″) linked together to form a continuous path operated by a gear 2. In this particular non-limiting embodiment, the modules (11, 11′, 11″, 11′″, 11″″) are defined by a planar core with a thickness that coincides with the thickness of the belt, from the longitudinal edges of which there emerge a plurality of protuberances like one-piece elements distributed in a staggered pattern on both edges, said protuberances being configured to give passage to the hinge pins between modules (11, 11′, 11″, 11′″, 11″″), forming the modular belt 1 itself which is driven by means of a gear 2 or sprocket.

(8) The invention comprises at least two sensors: (a) a first sensor 33 configured for detecting the passage of a plurality of reference elements (10, 10′, 10″, 10′″, 10″″) inserted in the modular belt 1, in this particular embodiment, at least one indication per module (11, 11′, 11″, 11′″, 11″″); and (b) a second sensor 43 configured for detecting the passage of a reference element 22 in the drive shaft 21.

(9) In a particular embodiment, the system comprises a temperature sensor (34) since temperature is a very important factor in studying the behavior of modular belts 1. The measurement of the working temperature of the modular belt 1, i.e., the measurement at which each of the modules (11, 11′, 11″, 11′″, 11″″) making up the modular belt 1 works, is a value which conditions its operation. The measurement of the working temperature in the room will be an estimate which will usually be sufficient. Therefore, the measurement of the temperature must be performed as close as possible to the modular belt 1 to thereby also estimate that actual temperature. Nevertheless, a temperature sensor 34 can be implemented for obtaining an actual measurement of the working temperature of each module, obtaining results of the working conditions of the conveyor belt with the temperature that are much more precise.

(10) With the detection of temperature, of temporary references with the first and second sensors (33, 43), and the subsequent calculation of the passage at that time, the change in elongation with respect to the nominal measurement and tolerance thereof can be calculated, successfully calculating at all times: (i) if the conveyor belt 1 will engage properly upon reaching the gear 2, or otherwise, if it may slip out of engagement, damaging both the surface of the belt 1 and the teeth of the gear 2; (ii) if it is exposed to permanent deformations and/or breakages upon reaching, exceeding, or approaching its elastic and/or breaking limit; (iii) if it requires any maintenance to give more tension to the system; (iv) if it will require replacement in a short period of time; (v) if it is working outside the allowed temperature limits; and even (vi) the conveyed load which is referred to as production in manufacturing processes; (vii) the uniformity of the production through the supported loads and the resistance to which the belt is subjected.

(11) FIG. 2 shows an exploded view of a first passage detecting apparatus 3 for detecting the passage of the reference elements (10, 10′, 10″, 10′″, 10″″) inserted in the modules (11, 11′, 11″, 11′″, 11″″) of the belt 1; in this particular embodiment, there is one indication per module. This first apparatus 3 comprises an inverted C-shape casing 31, such that the belt 1 passes precisely through the concave region 35 of said casing 31 which is configured for the belt 1 to slide through said concave region 35.

(12) Two sensors, one passage detection sensor (33) and another temperature sensor (34), are housed in the casing 31 (as best seen in FIG. 3) connected with a signal processing circuit 32. The object of the passage detection sensor 33 is precisely to detect the passage of the reference elements located on the conveyor belt (in FIG. 3, the third indication 10″ and the fourth indication 10′″) so that after acquiring the signal from the passage detection sensor 33, the time of passage between consecutive pairs of reference elements is calculated.

(13) More passage detection sensors 33 or temperature sensors 34 can be incorporated.

(14) Nevertheless, in the case of the invention, the passage detection sensors 33 are not conditioned to be at a specific distance apart, which distance is smaller than the distance of the passage of the chain (like in patent document GB2406844).

(15) FIG. 4 shows a view of the second passage detecting apparatus 4 for detecting passage in the rotating shaft 21. This rotating shaft 21 (preferably a drive shaft) is cottered 23 in this non-limiting example and houses a reference element 22, which is detected by means of a passage detection sensor 43 which is suitably fixed to the casing 42 which is in turn fixed to the rotating shaft 21 by means of a bearing 41 so as not to hinder its rotation therein.

(16) The output signal of the sensor 43 is connected with the signal processing circuit 32 located inside the first apparatus 3. The second apparatus 4 is therefore prepared for detecting the time of passage of the reference element 22 of the rotating shaft 21, such that this time reference will then allow calculating the linear speed of the modular belt 1.

(17) In a practical embodiment, the signal processing circuit 32 comprises at least of one receiver-emitter system with an embedded operating system and a memory sufficient for processing and storing, in the form of matrices, the signals received from the sensors 33, 34 and 43 including instructions for: (a) receiving and interpreting the signals; (b) calculating the detection times between consecutive signals T.sub.V and T.sub.P; (c) storing them preferably in matrices; and (d) delivering all those detection times between reference elements T.sub.V and T.sub.P, as well as the temperature values at all times to an external server.

(18) The technology used for the detection of passage and temperature in the sensors 33, 34, and 43 can be any technology selected from inductive sensors, capacitive sensors, laser sensors, optical sensors, magnetic sensors, color sensors, infrared sensors, radiofrequency sensors, ultrasound sensors, or any combination thereof.

(19) The method for monitoring modular conveyor belts 1 implemented in the system illustrated in FIGS. 1 to 4 comprises: (a) a signal measurement step which in turn comprises: (i) calculating the time of consecutive passage T.sub.V of the reference element 22 placed or inserted on the drive shaft 21 of the gear 2 by means of the second apparatus 4; and (ii) calculating the time of passage of the indication 33, T.sub.P inserted in the modules 11 of the modular belt 1 by means of the first apparatus 3 and (iii) measured through the sensor 34 of the temperature T.sub.A; (b) a delivery step for delivering the detection times between reference elements T.sub.V and T.sub.P and temperature T.sub.A to an external server; and (c) step for processing in the external server the signals received in step (b), and calculating the speed of the modular belt 1 and the possible elongation thereof.

(20) In step (b), it is important to deliver the unprocessed signals, i.e., delivering the detection times between indication of the shaft T.sub.V (which is the time for calculating the speed of the modular belt 1) and the detection times between reference elements of the passage T.sub.P (time for calculating the passage) since the processing time in the actual processor circuit 32 is thereby reduced, and simplifying the programming and maintenance thereof. Furthermore, as a result of the above, the reference data from the external server can be modified to enable using the system in different types of belts 1 and gears 2 according to each specific application, without the need to reprogram the processor circuit 32.

(21) In step (c), the values used are previously determined depending on the material of the belt 1, its hinge, the shaft, its gears 2, coefficients of friction, and together with the temperature value T.sub.A, the rest of the data can be provided in the external server, where said data can be consulted by means of connection with fixed and/or mobile devices anytime and anywhere.

(22) Therefore, in step (c) and by knowing the reference of the indication placed on the drive shaft and applying the following mathematical formula, the linear speed thereof will be obtained:
Linear speed V=2πr/T.sub.v

(23) where: V: linear speed T.sub.v: time unit between two consecutive detections of the passage of the indication over the sensor in the drive shaft. r: radius or distance at which the indication is placed in the shaft

(24) Once this speed is obtained, the real value will be used at all times or the averaged value will be used, depending on processing need and speeds. With this value of speed and the time between consecutive reference elements placed on the conveyor belt, T.sub.P, the actual passage is obtained in each passage:
Actual passage=V×T.sub.P

(25) Based on these values and the obtained temperature value, comparing them with the reference values and applying the corresponding formulas, there will be shown important immediate information, such as: temperature, linear speed, percentage of resistance the belt is using at that time, “elongation vs. engagement” with the subsequent prediction of possible gear slips due to excessive load, or change due to the service life coming to an end, the need for preventive maintenance to remove rows from the belt so as to provide more tension thereto, and so that it works in optimal conditions for its service life and maximum duration.