2020.02.04
Summary:Aiming at the traditional powder filling industry's inefficiency, inaccuracy, complexity, difficult to control and other shortcomings, the article uses Siemens PLCS7-200 for the design and application of the weighing and filling machine system.S7-200PIC's performance is superior, both the flexibility of the computer, good versatility and relay control is simple and easy to understand, easy to maintain the double advantages, in addition, its good communication interface to the designer Great convenience. Focuses on the working principle and process of the filling machine, and the software design process of PLC, and its development status and prospects.
1 Preface
As we all know, the level of automation in China is increasing, and the application of automatic control technology in many fields becomes more and more extensive. The filling industry has a long history, and after roughly experiencing manual weighing, relay control, and weighing instrument control, PLC control technology began to be widely used.
China's filling industry consists of three major blocks. The first block is to filling raw and auxiliary materials and filling machinery and equipment based filling basic industry, this piece belongs to the capital set and technology-intensive industry, with relatively high value-added industry, but also has a high industry entry threshold and industrial competition barriers. The second piece is by the paper, plastic, metal, glass, the four filling and filling printing of filling products manufacturing industry, this large piece of enterprise basically belongs to the labor-intensive enterprises, is the general competitive processing industry, with geographical cost advantage, low barriers to entry, production value added is relatively low, but now the market competition is also very fierce. The third block is by the filling agent, scientific research, management agencies and other filling services and filling management industry, this part belongs to the knowledge-intensive industry, high value-added, low barriers to entry, this type of enterprise is developing rapidly, but the overall level of development is not very high, the whole industry is not standardized. The development of these three major blocks constitute the overall development of China's filling industry. Filling equipment is the most important feature of the complexity of the action, frequent, and a greater number of executive elements, the use of other control equipment in this occasion such as relay control logic will inevitably require a large number of intermediate relays, and these intermediate relays in the case of control with PLC, it can be programmed to replace the auxiliary relays within it. And then from the physical point of view to elaborate: the former requires specific electrical components to combine, and the PLC's internal registers in the PLC programming capacity permits the scope of the complex control logic can be realized at no extra cost.
There are many types of filling machines, according to the product state, there are liquid, block, bulk filling machine; according to the filling industry, there are food, household chemicals, textiles and other filling machines; according to the filling station points, there is a single-station, multi-station filling machine; according to the degree of automation, there are semi-automatic, automatic filling machine, etc. Liquid filling machine that is, filling liquid products filling equipment, such as beverage filling machine, dairy filling machine, viscous liquids, liquid cleaning machine, food filling machine, liquid cleaning machine, liquid filling machine, liquid filling machine, liquid filling machine, liquid filling machine, liquid filling machine, liquid filling machine, liquid filling machine, liquid filling machine, liquid filling machine, liquid filling machine, liquid filling machine, filling machine, liquid filling machine, liquid filling machine, liquid filling machine. Food filling machine, liquid cleaning products and personal care products filling machine and so on belong to the category of liquid filling machine.
Block filling machine that is filling block product filling equipment, now on the market soap, cupcakes, bread, etc. are using this equipment, generally a molding, fast, convenient.
Bulk filling machine can be divided into particle filling machine and powder filling machine. Granule filling machine because the material is granular, good fluidity, easy to control, usually using gravity feeding, filling high precision, good results.
Powder filling machine, also known as powder filling scale, is developed for fertilizer, chemical, food and pharmaceutical industries such as powder filling, can be fully applicable to 5-50Kg powder material semi-automatic metering filling filling; supporting screw elevator, belt conveyor, sealing and filling device, manual bag, automatic bag clamping, metering, filling, bag drop, conveying, manual assistance into the sealing station, heat sealing the inner bag or sewing the outer bag, to complete the semi-automatic Filling process. Due to the characteristics of the powder, the requirements of the powder filling machine greatly increased, powder due to poor fluidity, easy to caking and clogging pipeline, so for the performance of the powder filling machine and filling accuracy also have higher requirements. Aiming at the characteristics of powder filling, design PLC based weighing and filling machine control system to improve the accuracy of powder filling.
