Aiming at the problems of high performance piston head can not produced by using casting and hot die forging, the warm extrusion molding method is proposed, based on the analysis of factors influencing for forming, rational scheme of orthogonal experiment was designed, a series of analysis for simulation results by using the range analysis method and comprehensive balance method, the optimal forming process parameters combination are identified, the optimal result are verified by the DEFORM software.

In order to try to reduce the influence of weld mark on the appearance quality and mechanical properties of plastic products, with the combination of injection molding simulation software and the orthogonal test design, reasonable test analysis programs was designed. Products weld mark depth was the evaluation index, and get the optimal parameter combination which could control the quality of the weld, then the results was verified by molding simulation. The results show that through the optimization of process parameters combination, the weld quality was improved and the negative impact on plastic parts was reduced.

The design of heating systems with groundwater source heat pumps (GWHP) is very important for reducing their power consumption. For better design, reasonable analysis of the systems is necessary. In this paper, a dynamic exergy and exergetic cost analysis of a heating system with GWHP is performed in a whole heating season by the use of structural theory of thermoeconomics and the software of TRNSYS. The relative exergy destruction of every component and the exergetic cost of the final product of the system are obtained. The results show that the heat pump has the largest relative exergy destruction under all the working conditions. The terminal unit component has the second largest relative exergy destruction at conditions above 10% load. However, at 10% load, well water transportation component has the second largest relative exergy destruction. The unit exergetic cost of the system final product during the whole heating season is 8.51W/W, similar to the result at 75% load.

In order to obtain high-quality injection head, cold extrusion forming is adopted. Based on the study of forming technology for the injection head, reasonable process flow, cold extrusion pre-treatment process and boundary conditions are designed. Two finite element models in forward extrusion and backward extrusion forming ways are established. Taking DEFORM as the platform, the numerical simulation of forming process is carried out. Through simulation, the distribution of strain field, stress field and velocity field in the process of cold extrusion forming is preliminarily forecast, the merits and defects of two kinds of forming processes and the force state of mold are compared , the optimal forming scheme is determined.

According to the problem of core-pulling in the injection mold design of side holes plastic parts, analyzed the structural features and forming process of side holes plastics. Introduced the injection mold structure of side holes plastics, the design essentials and working process of the injection mold, then reasonable mold structure and side core-pulling mechanism ware designed. The design of inclined guide pillar core-pulling and combined core mechanism reduced the die cost and made the manufacture convenient.