The automatic filling machine achieves the amount of metering through the number of revolutions of the screw, in order to achieve the purpose of adjustable metering size and improve the metering accuracy, the screw's speed is required to be adjustable and the position is positioned accurately, the stepping motor is adopted to control the screw's rotation speed and number of revolutions, which not only simplifies the mechanical structure, but also makes it very convenient to control. Without overloading, the speed and stopping position of the stepping motor only depend on the frequency of the pulse signal and the number of pulses, and are not affected by the change of load. The stepper motor and screw are directly connected in a way that is simple in structure and easy to maintain. It is worth pointing out that, if the overload capacity of the stepping motor is relatively generation, when a slight overload, there will be considerable noise. Therefore, after the measurement conditions are determined, it is necessary to choose a larger overload coefficient to ensure that the stepping motor balanced work.

Automatic filling machine using computers to achieve the human visual function, the machine instead of the human eye to do the measurement and judgment, the use of photoelectric imaging system to collect the image of the controlled target, by the computer or a special image processing module for digital processing, according to the image of the distribution of pixels, brightness and color and other information, size, shape, color and so on the identification. This organically combines the rapidity and repeatability of the computer with the high degree of intelligence and abstraction of the human eye's vision, which greatly improves the flexibility and automation of the production process inspection, saves a lot of manpower, improves inspection efficiency and ensures product quality.

Filling system according to the production requirements, when the production line needs to feed a material, production workers press the control button on the corresponding station, through a kind of communication module based on INTERBUS field bus, send the name of the material, station number, quantity and other information to the LED large screen display, while starting the music bell and light up the station and light box on the corresponding material's indicator light. Warehouse staff get the information, press the corresponding button under the light box indicator to answer, then the light box on the light of the material on the indicator light off, indicating that the information is confirmed to have begun to feed. According to the confirmed information, the bus controller will turn the indicator light above the button of the workstation from normal light to flashing state, indicating that the material is being fed. When the material arrives at the called station, the operator restores the button to the disconnected state and the indicator light goes out, indicating the end of the distribution process for that material.

The weighing and filling machine consists of S7-200PLC and weighing instrument ICS241 and filling solenoid valve. PLC uses RS232C communication port to connect with the weighing instrument to collect and process the weight data through communication, as well as send tare signal to make the instrument tare. In the quantitative filling mode, the PLC receives the data from the weighing instrument as the main controller, processes the data and sends out a series of signals to control the action of the filling machine, so that the filling machine completes the quantitative filling. the PLC communicates with the weighing instrument through RS232C, and the communication between the two is a protocol-free communication, the parameters of the serial communication between the PLC and the weighing instrument need to be set in the same way. The PLC communicates with the weighing instrument via RS232C, the parameters of serial communication between PLC and weighing instrument should be set the same.

The weighing and filling machine only needs to place the barrels of the same specification neatly in the designated position, made by PLC programmable controller, two-stage automatic filling mode of large and small materials, with automatic judgment of empty barrel function and empty scale not filling function, the controller is configured with manual buttons for all the actions, and the double-window display of the special filling control instrument can display the target amount, filling amount, number of barrels, time and date, and other information. Automatic filling machine also includes front weighing module, reweighing system, LMC series motion controller, LXM series servo drive and servo motor, and upper computer monitoring system. The servo motor is utilized to realize the rotor pump stroke control and thus the filling volume control. Before filling, the front weighing module obtains the weight of empty barrel, after filling, the rear weighing module obtains the weight of filling and transmits it to the weighing instrument, which will read out the filling data in real time to get the weight deviation, and the filling algorithm calculates the control volume of large materials, and the weighing control system sends the control volume to the servo driver, which drives the quadratic rotary pump to perform the early closure of the small material volume and then control the small material filling valve, and the upper computer reads out the filling volume in real time through the Ethernet and connects with the weighing instrument. The upper computer is connected to the weighing instrument through Ethernet to read the filling data in real time, and can set the process parameters to monitor the operation of the production line. After the filling is completed and the cap is pressed, drive the gripping manipulator device to accurately position to the designated unit, and grab the filling barrel on the material table to transport to the designated place and then put it down. The servo motor drives the manipulator, utilizes the high-speed pulse output function of PLC, and realizes the accurate stacking control of the manipulator through PTO programming. When giving one electric pulse signal to the stepper motor, the stepper motor turns over 0.9 degrees; when giving two pulse signals, the stepper motor turns over 1.8 degrees. And so on, continuously given pulse signals, the stepper motor can run continuously

(1) Electrical pulse signal generator, according to the given settings repeatedly for the stepper motor to deliver electrical pulse signals, most of such signals by programmable controllers or microcontrollers to complete;

(2) drive (signal amplifier), in addition to the electrical pulse signal amplification, drive the stepper motor rotation, but also through it to improve the performance of the stepper motor, in fact, it plays an important role in the stepper motor system, generally a stepper motor can be based on different conditions with a variety of drivers;

(3) stepper motor, there are a variety of control principles and models, now commonly used reactive, inductor type, hybrid and so on. The speed control of the stepper motor is realized by the input pulse frequency fast or slow. When the frequency of the pulses occurring decreases, the speed of the stepper motor decreases; when the frequency grows, the speed increases. It is also possible to increase the speed or positional accuracy of the stepper motor by changing the frequency. The position control of a stepper motor is controlled by the number of pulses given. Given a pulse, a step angle is turned, and when the position of the stop is determined, the number of pulses to be given to the stepper motor is also determined. In filling machine control, the number of given pulses is also related to the parameters of the mechanism, such as the diameter of the screw. In many cases in the filling need to control the running speed and running position of the actuator, before are through the mechanical or other ways to complete, the mechanism is complex, not easy to adjust. After changing to stepping motor, not only can make the structure of the liquid filling machine become simple, easy to adjust, reliability growth, and accuracy will be greatly improved.