Application of the hottest stepper motor packing m

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This paper discusses the working principle and application characteristics of stepping motor, introduces several application examples of stepping motor in packaging machinery, and points out that stepping motor has a broad application prospect in packaging machinery

key words: stepper motor packaging machinery application

gear pump controlled by stepper motor can also achieve accurate measurement. Gear pump has been widely used in conveying viscous substances, such as syrup, bean paste, Baijiu, oil, tomato sauce, etc. At present, piston pumps are mostly used in the measurement of these materials, which have the disadvantages of difficult adjustment, complex structure, inconvenient maintenance, large power consumption, inaccurate measurement and so on. Gear pump metering is based on the meshing and rotation of a pair of gears, and materials are forced from the feed port to the discharge port through the space between teeth. The power comes from the stepping motor. The position and speed of the stepping motor are controlled by the programmable controller, and the measurement accuracy is higher than that of the piston pump

the stepping motor is suitable for running at low speed. When the speed is increased, the noise of the stepping motor will increase significantly, and other economic indicators will decrease significantly. For the gear pump with high speed, it is better to select the speed increasing structure. We started to adopt the structure of step motor direct connected gear pump on the viscous body packaging machine, resulting in unavoidable noise and reduced reliability. Later, the speed of the stepping motor was reduced by means of spur gear acceleration, the noise was controlled, the reliability was improved from the second half of 2016, and the measurement accuracy was guaranteed

III. application of stepper motor in the supply and delivery of packaging film

in the packaging machine integrating bag making, filling and sealing, it is required that the plastic film is used for positioning and fixed length supply. Whether intermittent supply or continuous supply, it can be reliably completed by stepper motor

1. For intermittent packaging machine

the reliability of intermittent packaging machine can be improved by using stepping motor to supply film. In the past, the way of intermittent belt drawing of crank connecting rod mechanism with 40000 bacteria in each person's hands was used for the supply and delivery of packaging film, which was complex in structure and difficult to adjust, especially when the product needed to be replaced, it was not only difficult to adjust, but also a lot of waste of packaging film. The step motor is used to directly connect the tension belt with the tension roller, which not only simplifies the structure, but also facilitates the adjustment. It can be realized only through the button on the control panel, which saves the adjustment time and packaging materials

in the intermittent packaging machine, the supply and delivery control of packaging materials can adopt two modes: bag length control mode and color code control mode. The bag length control mode is applicable to the packaging film without color code. It can be realized by pre setting the speed of the stepping motor, and the setting of the turn to empty ratio can be realized through the dial switch. The color code mode is equipped with a photoelectric switch, which detects the position of the color code. When the color code is detected, it sends a control switch signal. After receiving the signal, the stepper motor stops rotating. After a certain time delay, it turns the film supply again and again to ensure that the film supply length is determined according to the position of the color code

2. For continuous packaging machine

in the continuous packaging machine, the stepping motor rotates continuously, and there is no building insulation material that can deliver the packaging film evenly and continuously. When changing the bag length, it can be achieved only through the dial switch

IV. application of stepping motor in horizontal sealing

in continuous packaging machine, horizontal sealing is a very important actuator and one of the more complex mechanisms in packaging machine. Especially for the packaging film with color code, the requirements for the sealing and cutting position are extremely strict. In order to improve the accuracy of cutting, people have successively developed eccentric sprocket mechanism and crank guide rod mechanism, but these mechanisms have the disadvantages of troublesome adjustment and low reliability. The main reason for these shortcomings is that the process requires the cross sealing wheel to be fixed speed and cut off

the step motor directly drives the transverse sealing wheel to realize speed synchronization. The film feeding wheel of the continuous packaging machine is used for continuous film feeding. During horizontal sealing, the linear speed of horizontal sealing is required to be synchronized with the speed of film feeding to avoid tearing and accumulation of films. Because the cross seal often produces unacceptable odor and smoke, the diameter of the sealing wheel is constant. When changing the bag length, it needs to be changed by changing the rotation speed of the cross seal wheel. However, the cross seal takes a certain time, that is, it takes a constant time from the contact between the cross seal wheel and the film to leave, otherwise the seal is not tight. The total time of each revolution of the cross sealing wheel and the time required for the cross sealing are constant. To meet the requirements of speed synchronization, the speed of the stepping motor in a week can be divided into two parts. One part first meets the requirements of speed synchronization, and the other part without load meets the requirements of the total time of a week

in order to achieve good sealing quality, the non constant speed control mode of the cross sealing wheel can also be realized through the stepping motor, that is, the speed synchronization can be realized at each point of the cross sealing, which is not stated here due to space limitations

the characteristics of stepper motor are mainly attributed to three aspects: first, good overload performance. Its speed is not affected by the load. Unlike ordinary motors, when the load increases, the speed will decrease. Therefore, stepping motors are used in occasions with strict requirements on speed and position; Second, convenient control. The stepping motor rotates in the unit of "step", and the digital characteristics are obvious, which brings great convenience to the computer control. In turn, the emergence of the computer has opened up a broader market for the stepping motor; Third, the whole machine is simple in structure. The traditional mechanical speed and position control structure is complex and difficult to adjust. After using the stepping motor, the structure of the whole machine becomes simple and compact

the application of stepping motor in packaging machinery has just begun. In the past, many traditional mechanical control methods can be replaced by stepping motor. In addition to the above-mentioned uses, it has also been applied in printing, filling, wrapping, etc. it is believed that in a short time, China's packaging machinery industry will be able to leap to a new level on the platform of stepping motor technology

author/Wu Longqi materials and equipment of Henan University of science and technology

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