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当今人们一般认为,无论是直接喷射或非直接喷射的点燃式内燃机,全柔性气门控制是最有希望的改进措施。内燃机制造商们对形形色色的控制系统进行了试验研究,但是目前只有简单的系统用于内燃机产品,而这只能满足部分要求。尽管液压系统很适宜于找到最佳气门控制策略,但机械系统对于一系列要求的优势是显而易见的。因此,在开发出具有最多可达三种可供选择的气门升程曲线的机械移相机构和机械系统之后,利用机械系统的优势和经验来实现全柔性气门控制是顺理成章的事了。本文介绍德国卡尔斯鲁厄(Karlsruhe)大学开发了一种叫Δ控制的新型机械气门机械,这种新机构能对气门升程、开启时间和相位角进行连续调节。该机构有一个特别之处,就是仅有机构的一部分(三角形),必须加上一个常规牵引杆或挺柱气门机构。文章第一部分介绍关于系统本身的一些信息,即它的工作原理和改进气体交换的可能性。介绍了Δ控制的不同变型,并且指出了气缸盖设计特殊性能和边界条件。第二部分综述执行不同运动学和动力学任务的配气机构的设计过程及其开发工具。第三部分则叙述了Δ控制在内燃机产品中的应用和最重要的试验结果。
It is generally accepted today that fully flexible valve control is the most promising improvement, either directly or indirectly. Engine manufacturers have experimented with a wide range of control systems, but at present there is only a simple system for internal combustion engine products that can only meet some of the requirements. Although hydraulic systems are well suited to finding the best valve control strategy, the mechanical system’s advantages over a number of requirements are obvious. Therefore, after developing a mechanical phase-shifting mechanism and a mechanical system with up to three alternative valve lift curves, it is logical to take full advantage of the mechanical system and experience to achieve fully flexible valve control. This article introduces a new mechanical valve mechanism called the Delta control developed by the University of Karlsruhe in Germany. This new mechanism continuously adjusts valve lift, opening time and phase angle. A unique feature of this body is that only a part of the body (triangle) must be added with a conventional drawbar or tappet valve mechanism. The first part of the article introduces some information about the system itself, that is, how it works and the potential for improved gas exchange. Different variants of the delta control are introduced, and the special design of the cylinder head design and the boundary conditions are pointed out. The second part reviews the design process and development tools of the valve train to perform different kinematics and dynamics tasks. The third part describes the application of delta control in internal combustion engine products and the most important test results.