Research On The Critical Design And Mass-producing Techniques Of Ceramic Rocker Arms Based On CAX

Overhead cam (OHC) valve train has been widely adopted in modern high-speed internal-combustion engines for better dynamic characteristics. In this kind of valve train, the rocker arm is an important part that has great influence on the overall performance of the engine. For such reasons as severe working conditions and comprehensive overall properties requirements, new product development of rocker arm has been becoming the focus of research abroad and domestic in recent years. This paper is centered on the development of a new rocker arm for the TJ370Q engine. Taking it as an example, the design techniques and key manufacturing process of the up-to-date high-performance rocker arm: the aluminum die-cast rocker arm with a ceramic insert (called"ceramic rocker arm"for short below) were studied in depth using such methods as the theory of new product development, CAI, CAD, CARE, CAE etc. The main research works of this paper are summarized as follows:1. On the basis of analyzing the properties requirements of rocker arm together with giving an overview of its present research state and future trend of development both at home and abroad, the contents and great significance of this research has been set forth.2. By utilizing the Computer Aided Innovation software TechOptimizerTM?, the technical principle of the ceramic rocker arm has been put forward, and then the so-called"fully wrapped"joining structure between the ceramic insert and the aluminum rocker arm base has been invented preliminarily as well as the innovative overall process flow called"reverse-locating machining"has been laid down. Based on the work aforementioned, the whole development plan of the new ceramic rocker arm has been constituted by means of PERT-CPM method.3. It has been clarified that the design of ceramic rocker arm pertains to reverse design. With this understanding, this paper expatiated in detail on how to seek out the working loads and design parameters of the rocker arm in reverse order by employing computer aided reverse engineering (CARE) technology in place of the conventional calculation model.4. Research continued on advancing the design principles of ceramic rocker arm together with its parametric CAD modeling and FEA-based shape optimization methods. In terms of the innovative idea of"fully wrapped joining"and the status in quo of recent research on the joining techniques of ceramics and metals, an inverse-wedge-shaped ceramic insert was designed with such strong points as saving material, low cost, reliable joint and easy to manufacture, and some experiential data about it were provided accordingly. Moreover, A method of rapid function prototype trial producing of the ceramic rocker arm was recommended by a combination of two techniques, namely rapid prototype manufacturing (RPM) and metal mould inverse casting. Withal, the structural design...