The internal and external lifting arms, the transmission rod of the separation manipulator and the brake housing of the tractor are small parts. There is a need for small batch manufacturing in the stage of product structure design, process adjustment and new product trial production. Small parts generally have small size, simple structure and high requirements for cost and manufacturing cycle, especially in the trial production stage of new products, sometimes only 3-5 pieces are required. For small tractor parts with small batch demand, if they are manufactured by traditional casting method, even if they are trial manufactured by wood mold casting method with the lowest cost, the general manufacturing cycle is 2 ~ 3 months and the cost is more than 3000 yuan. The development cost and cycle can not meet the needs of customers. Moreover, due to the high process risk of new products and processes, there are also problems such as high scrap rate and cost. The development and manufacturing of small order products, new products and new processes of China Yituo belong to the demand of small batch manufacturing. At present, the traditional modeling manufacturing method has the problems of high investment, high energy consumption, high pollution, low quality, low benefit and low output. To sum up, it is necessary to develop a fast, efficient and low-cost casting method to meet the needs of small batch manufacturing of tractor small parts.
(1) The combination of CAD, CAE and dieless forming technology is applied to the casting of tractor small products, which saves the development and manufacturing of molds, shortens the manufacturing cycle by more than 85% and saves the cost by more than 70%.
(2) The rapid casting of tractor small parts is realized by using dieless digital precision forming machine and NC cutting technology. The dimensional accuracy of the casting is less than 0.5 mm and the surface roughness is ra 25 μ m. Dimensional tolerance class CT10.
(3) The optimum conditions for strength and processability of sodium silicate sand blank and phenolic resin sand blank are as follows: the amount of sodium silicate is 5% ~ 6%, the amount of phenolic resin sand is 1% respectively, and the amount of curing agent is 1% ~ 6% of cpi-1600.
At present, dieless casting precision forming equipment and technology have been applied to the rapid development of new product castings in automobile, aviation, water conservancy and other industries. This method not only has fast manufacturing speed, but also has high precision. It has the characteristics of digitization, precision, flexibility and greening. It is an accurate forming manufacturing method based on resource saving and environment-friendly. It is the key equipment to realize high-quality, efficient and green manufacturing of castings. In this study, the rapid casting method of tractor small parts is studied by using die-free casting precision forming equipment and combined with the needs of small batch manufacturing, rapid manufacturing and green manufacturing.