Best to improve the level of process equipment to

Improve the level of process equipment to meet the needs of automobile casting production. I. preface

with the transfer of medium and low-cost casting production bases in advanced countries to China, and the global procurement strategy has brought us opportunities as well as challenges. The original casting methods of enterprises cannot meet the requirements of the international market (especially the automobile market) for product quality and batch supply. At that time, the problem was that the production capacity of ordinary castings was surplus. There were 9 5t/h cupola in the whole plant. Foreign customers commented on our scale, but the grade was low and featureless. To develop, we should jump out of the price war of domestic peers, carry out technological transformation from a high starting point, and comprehensively improve the level of process equipment

II. Implementation principles of technological transformation projects

1. Take improving casting quality and enterprise benefits as the purpose of technological transformation

2. Take the market as the guide, optimize the product structure, produce high-grade castings, increase enterprise benefits, and enhance the aftereffect of continuous technological transformation of enterprises

3. In the project design stage, we must pay attention to strengthening the investment in environmental protection, safety and energy conservation, and move closer to green casting and cleaner production

4. Summarize experience and lessons in time. Make the subsequent technical transformation more perfect and practical

5. Training management, process technology, operation and maintenance personnel at the same time. Do a good job in advance quality planning and quality control plan, manage and use them well, and give full play to the efficiency of advanced process equipment

6. Promote the application of computer technology in casting production, and introduce computer-aided design CAD, aided analysis CAE and computer detection system

7. Plan as a whole, focus on reality and give consideration to the long term. Fully consider the balanced transformation of the level of each Foundry Department, and lay a good foundation for the subsequent development and reasonable logistics

III. The method of technical transformation of our plant

1. implement step by step and gradually improve

at first, most people, including the leadership, remained in the understanding of technical transformation, small transformation, large technical transformation has never been done, and they can only take the path of step-by-step implementation and gradual improvement. Therefore, sand treatment starts with the previous small 20m3/h clay sand treatment production line, and then build an 80m3/h clay sand treatment production line after accumulating experience; The molding equipment also starts with a single shock molding machine, followed by an fbo-ii, and then an fbm-iit box free automatic molding line, so that the investment is less and the effect is fast

2. Plant Wutong trees first, and then bring phoenix.

our factory obtained the self operated import and export right in 1995. Many foreign customers were contacted, but many orders were ruined because of the backward process and equipment. For this reason, the decision-making level made up its mind to become advanced. The current customers include famous foreign cars such as Volvo. After the 1990s, the hydraulic technology developed very fast, and the manufacturers decided to place orders only after investigating our advanced modeling lines on the spot. Of course, their review is harsh and comprehensive, but automatic production lines do account for an important part, otherwise customers will not even come to the review. However, the risk of this method is relatively high, and it must have marketable products and a greater confidence in potential customers. There are also many examples in China where the molding line is underoperated or even sealed due to the high operating cost of the molding line and the large investment in molds. Therefore, this method should be selected cautiously

3. Based on reality and paying attention to actual results

at that time, the idea of our factory was self accumulation and rolling development. The investment in technological transformation is all self accumulated funds. Therefore, we should widely learn from the experience of domestic advanced foundries and formulate a technological transformation plan suitable for the actual situation of our plant, so as to minimize investment and improve investment efficiency. For example, the main machine of the molding line is imported, the auxiliary machine is supplied domestically, the key equipment of the sand treatment line is outsourced, and the rest (including PC control) is designed and manufactured by ourselves, so that the investment is greatly reduced without reducing the technical level of the complete set of equipment

4. Pay equal attention to both software and hardware, and provide strong support

technological transformation should start from meeting the needs of customers. Only with advanced equipment, management and use cannot keep up, and it is also unable to provide customers with satisfactory products. Therefore, at the beginning of the project, management, technology, operation and maintenance personnel were trained at the same time. Therefore, once the project is accepted, it can be put into production immediately. Although some enterprises have a large one-time investment, the follow-up funds are insufficient and the management is poor. For example, there are no professional maintenance personnel or they do not pay attention to the maintenance personnel, and the salary is poor, resulting in the poor quality of the maintenance personnel, or the maintenance system is not sound and clear, and they do not pay attention to the normal maintenance. The equipment is repaired only after failure, and there are no spare parts during the repair, which often leads to the shutdown due to a small failure. Our practice is to equip a high-quality professional maintenance team, establish a strict pre inspection, inspection and daily maintenance system and a special spare parts warehouse

IV. contents and steps of technical transformation

take the foundry workshop in the third plant area of our factory as an example. The construction scale of the workshop is large, the starting point is high, and the total construction area is 8640 ㎡. The workshop is composed of five parts: melting department, sand treatment department, molding department, core making department, and power distribution facilities. As the 6210 ㎡ cleaning and packaging auxiliary workshop in the south of the workshop is under construction, the cleaning is temporarily placed in one span with the core making department

the melting department, sand treatment department and power distribution facilities are 14 meters high, with a building area of 2592 square meters, and the molding department is 12 meters high. The building is planned to be installed and commissioned by the end of 2014, with an area of 6048 square meters, and the design program has an annual output of 10000 tons. According to the product structure, comprehensive conditions and development goals of our company at that time, the supporting facilities of the workshop were implemented step by step and gradually in place

(I) melting Department

configuration mode of melting Department: cupola electric furnace indirect duplex, cupola melts raw molten iron, ordinary castings are directly spheroidized and poured, and castings with high product quality requirements are heated, insulated or adjusted by electric furnace, and then poured. This configuration mode is relatively flexible and is currently an ideal configuration mode

equipment configuration: 1. One 5t/h cupola and two 7t/h cupola. This configuration method is more flexible. At the initial stage of production of the workshop, if the output is insufficient, only one 5t/h or one 7t/h cupola can be opened. When the production is full, two cupola can be opened at the same time and one cupola can be used for standby. 2. Two 2t/h medium frequency induction furnaces, two furnace bodies and two sets of power supplies, which can not only be smelted separately, but also be heated, insulated and adjusted. 3. One 10t/h medium frequency insulation electric furnace. The implementation steps are as follows: the configuration of cupola is in place in one step, and three furnaces are equipped at one time; 2t/h medium frequency induction furnace and molding line are implemented synchronously; The 10t/h medium frequency insulation electric furnace shall be considered after the product structure, batch and normal operation of the molding line

a set of daily molten iron composition tester (carbon equivalent meter nsp-550) and immersion wireless large screen digital display thermometer are equipped in front of the furnace. Metallurgical microscope in front of the furnace. In addition, the spectral analyzer in front of the furnace has signed a supply contract with speek, Germany, and will arrive at the factory in the near future

the melting department is equipped with spheroidizing cover bag and mechanical stirring (3) place the test piece on the desulfurization bag at the center of the spherical support plate of the movable table of the experimental machine. The spheroidizing treatment adopts electronic scales for weighing, and the quantitative accuracy is accurate. The workshop is equipped with four 5T electronic scales. The spheroidizing cover bag has obtained a national patent. Its remarkable feature is that during the spheroidizing treatment, it has less magnesium light, high magnesium absorption rate, less environmental pollution, simple structure, simple operation, and can stably reduce the addition of spheroidizing agent by 0.3% compared with the ordinary uncapped bag flushing method. The mechanical stirring desulfurization device can make the desulfurization rate of raw molten iron of cupola reach more than 85%, which can meet the requirements of automotive castings for low sulfur molten iron

(II) sand treatment department

the design production capacity of sand treatment is 80t/h molding sand, equipped with three sand mixers. In the early stage, considering that the supporting facilities of the molding department will not be fully in place within 2-3 years, first install two s1420t rotor sand mixers, and the other one is reserved. Due to the fbm-iit molding line at the end of last year, the sand mixing capacity has been significantly insufficient. At present, a purchase contract for a s1820 countercurrent rotor strong sand mixer has been signed

1. control of old sand temperature

① try to extend the cooling section of the molding line and control the sand falling temperature of the casting below 500 ℃

② the sand return belt is long, and the suction hood is arranged at multiple points

③ the new sand is directly added into the new sand bin without drying, and enters the double plate cooling mixer through the belt feeder to premix with the old sand

④ taking the above measures, the temperature of new and old mixed sand before reaching the sand mixer generally does not exceed 30 ℃

2. Control of molding sand particle size and purity

① set a suspension magnetic separation belt conveyor and a permanent magnet separation drum for secondary magnetic separation on the used sand return belt conveyor

② double wheel loose sand crusher and multi angle drum crushing screen are set for two-stage crushing

③ a double-layer polygonal roller screen and an inertia linear vibrating screen are set. It is worth mentioning that we attach a layer of stainless steel wire with a hole diameter of 1.1mm to the inertia linear vibrating screen to thoroughly screen out the sand masses, which is very necessary for the rotor type sand mixer. There is a factory near us that originally used the rotor sand mixer with di sand line. Because the molding sand contains a large number of sand masses the size of soybeans, the performance of the molding sand deteriorates, It seriously affected the modeling of Di sand line, and the scrap rate remained high. Later, the rotor type sand mixer had to be replaced by the roller rotor type sand mixer, and the original rotor type sand mixer was idle in the open warehouse

④ this should be thanks to the joint efforts of polymer manufacturers and product processing plants to prevent secondary sand from entering the circulation system, strengthen system dust removal, and effectively control the ash content in molding sand

3. Control of molding sand performance

sufficient sand storage is fully considered in the design to ensure the balanced operation of the system, and the old sand turnover cycle is long (less than 3 times a day), so that the old sand can be fully recycled, so as to give better play to the advantages of molding sand performance. In addition to the central physical and chemical room equipped with molding sand performance testing instruments, the site is also equipped with compactness, moisture, permeability and wet compressive strength testers, which can quickly and effectively control the quality of molding sand on site. The counterflow rotor type strong sand mixer selected during the second phase expansion is equipped with a molding sand detection system

(III) molding department and core making department

automotive castings have high requirements for product performance and internal and external quality. The dimensional accuracy grade of castings generally requires CT8, and the compactness of castings is good, requiring 100% nondestructive testing

1. molding equipment

in order to meet the above requirements, fbo-ii horizontal parting and decanting molding line and fbm-iit horizontal parting and decanting molding line from Shinto, Japan have been introduced successively. Both lines are injection molding lines, and the size of sand boxes are (450) respectively × five hundred and fifty × 150 ~ 200/150 ~ 200) mm and (508 × six hundred and sixty × 200 ~ 250/200 ~ 250) mm, and the maximum pouring weight is 25 kg and 50 kg respectively

2. core making process and equipment

with the molding line, the hot box core making process with high core making accuracy is adopted, and four z8612bf hot box core shooting machines and one z958 shell core machine are configured. According to the fact that the two molding lines are mainly small pieces, many cores weigh only about 100g, many manual hot box are designed and manufactured, which can be heated by electric heating or coke oven, which is convenient and fast. The above configuration basically meets the sand core requirements of the molding line

(IV) cleaning department

this department is temporarily set up, equipped with one q326 and q3210 rubber track cleaning machine and two Q378 hook cleaning machines. Both of the two kinds of equipment can effectively prevent the collision in the process of casting cleaning, which is very necessary for the production of automotive castings

(V) painting process and equipment

painting is an indispensable process for most automotive castings. According to customer requirements, we choose to adopt electrostatic powder painting method, which is characterized by solid powder