Weighing method of electronic belt conveyor scale capable of checking automatically

Abstract

The invention relates to a weighing method for an electronic belt scale capable of self-check, more than two weighing carrier rollers (3) form into a weighing device of the electronic belt scale, each weighing carrier roller is supported by more than two weighing sensors (5), each weighting sensor is respectively connected with a PLC (7) through an individual signal transmission line (8), the PLC can directly acquire an output weighing signal of each weighing sensor to monitor and diagnose each weighing carrier roller and weighing sensor on real-time in the weighing process. During a normal weighing, the method measures according to a multiple carrier roller mode. The PLC monitors, recognizes, diagnoses, groups and compares the weight signals after A / D transition on real-time, and calculates the material weight after integral arithmetic with speed signals of a motor or the belt. During thediagnosis, the weighing device treat according to more than two single carrier roller manners, and each weighing carrier roller is measuring cup for each other. The invention has strong ability of disturbance resistance, and can find out failures such as poor measuring accuracy, damaged weighing sensor, etc., the performance is stable and reliable, the failure point can be quickly checked out so as to be maintained conveniently, the maintenance capacity and component replacement quantity are in a small quantity.

Description

technical field [0001] The invention relates to the technical field of electronic belt scales, and mainly relates to a weighing method capable of accurate weighing and convenient fault detection. Background technique [0002] At present, the electronic belt scales produced at home and abroad are composed of a belt conveyor and a scale frame, including single roller, double roller, full suspension, direct load-bearing and other modes, and the weighing output voltage signals of all weighing sensors are generally It is all centralized input to the balance bridge, which is uniformly converted by the balance bridge to obtain an analog signal, which is then amplified, filtered, and A / D converted, and then sent to the PLC to calculate the weight of the material through calculation. First of all, because the load cell outputs a voltage signal and the voltage is small (generally 0-24mv), its anti-interference ability is poor, so the signal transmission distance cannot be too long; se...

AI Technical Summary

Problems solved by technology

First of all, because the load cell outputs a voltage signal and the voltage is small (generally 0-24mv), its anti-interference ability is poor, so the signal transmission distance cannot be too long; secondly, due to the centralized conversion of the weighing output voltage signals of all sensors As an analog signal, the entire weighing device has only one weighing output signal transmitted to the PLC, and it is impossible to monitor and diagnose each weighing sensor in real time

When the electronic belt scale has faults such as out-of-tolerance measurement accuracy and damage to the load cell during operation, it cannot be found in time; third, when the electronic belt scale is found to have faults such as out-of-tolerance measurement accuracy and damage to the load cell It is difficult to find the fault point in a short time, and we can only find it bit by bit from the mechanical system and weighing system based on experience. There are many fault points that can be judged, and the maintenance is difficult and takes a long time; Fourth, due to the adoption of The hardware balance bridge needs to match the characteristic parameters of 2 or more load cells. Once one of the load cells is faulty and needs to be replaced, or when purchasing, it is necessary to make special requirements according to matching, which increases the cycle and time of purchasing components. It also brings difficulties to the user's spare parts management, or replaces all load cells together, resulting in waste

[0003] The Chinese patent No. 97219802.4 discloses a belt scale with double scales, which only adds a weighing device on the basis of the existing electronic belt scale, but each weighing device can only output one output signal , although the judgment and alarm when the measurement accuracy is out of tolerance is realized through the comparison of the two weighing devices, it cannot automatically and accurately determine which weighing device is faulty, so it cannot automatically switch to the non-faulty weighing device. The heavy device continues to work and can only be shut down for maintenance. It is still difficult to find and judge the fault point of each weighing device during maintenance; if the weighing device uses 2 or more weighing sensors, there is still the problem of sensor matching

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