Weighing conveyor is a continuous material flow weighing device designed by gravity weighing principle. It has the advantages of large flow range and no special feeding equipment. Using thick material layer with low speed and single measuring roller structure, the Electronic scale has the characteristics of reasonable structure, small volume, large mechanical strength, small deformation and good long-term stability. Automatic alignment, tension adjustment, internal and external belt scraper and other mechanisms can ensure the high measurement accuracy and stability of the scale body, the structure design of the scale body, so that the replacement of the belt is convenient and fast. Can be used for material measurement can also be used as quantitative feeding equipment; Electronic scales can be used either individually or in groups. The control part has two forms of single-channel instrument control and IPC multi-channel centralized control. When it is necessary to use multiple channels (such as batching), it can form an upper and lower machine structure with the industrial computer and be centrally controlled by the control room.

The weighing conveyor adopts the sequential execution design, each function module can be directly invoked, the main program completes the initialization of the system, the selection of serial port working mode, the setting of external interrupt, the cycle waiting for interruption, the weight detection, the weight display, the load weight control and alarm. The setting of the load weight, the display of the set load and the starting of the system are completed by the interrupt service program.

The system takes weighing instrument and microcomputer as the control core, piezomagnetic sensor as the weighing module, weighing instrument as the analog-to-digital conversion device, plus some auxiliary control circuit and power amplifier circuit weighing conveyor loading system. After the lifting skip reaches the bottom, the loading open button is touched, and the conveyor starts to carry out rapid loading with the running speed of 1.2~1.5m/s. When the loading amount reaches the pre-set value, the conveyor stops running, stops loading, and sends out the loading signal to lift the materials. At this time, the conveyor operates at a low speed and is loaded from the coal bunker to the quantitative conveyor.

The system can complete the quantitative loading task safely, efficiently and accurately. After the skip is in place, the unloading can be completed automatically; The load can be manually set through the keyboard and has the display function; It can monitor the working state of the system, alarm the system in time when it fails, and take corresponding measures.

The whole control system can be divided into the following parts according to the function: forward signal input channel, backward channel, power supply, start circuit, reset circuit, clock circuit, keyboard and display. The piezomagnetic sensor is used as the weighing module in the forward signal input channel. Together with the bridge capacitor filter rectifier circuit, a precise weight measuring circuit is formed. Back channel MCU output a total of 5 control signals, and then by the circuit composed of transistors to amplify it, finally control the AC contactor and solenoid valve on and off, and then control the working state of the motor, loading motor and unloading motor start, stop, as well as the corresponding air bag clutch working state. The motor is connected with the belt conveyor through the air bag clutch, the reducer, and the quantitative loading and unloading are realized under the control of the single chip computer.

The loading and unloading of the weighing conveyor are carried out by two motors of the same series with different capacities respectively. The power of the loading motor is relatively small, and the rotational speed of the motor output shaft and the roller shaft is relatively large. Therefore, the speed of the quantitative conveyor is relatively slow during loading, so that the materials on the tape will be more uniform. Moreover, it also helps to open the warehouse door, the Feeder and the quantitative conveyor to coordinate their work. The unloading motor power is large, and the speed ratio between the motor output shaft and the roller shaft is relatively small, so the unloading speed is large, which will reduce the time required for the working cycle and greatly improve the working efficiency of the loading system of the quantitative conveyor. In addition, the method of using two motors for time-sharing driving to obtain two working speeds is relatively simple, economical, and easy to maintain and overhaul.