关键词: L113 尺寸；影响因素；主断面；定义方法

Abstract: The X-axis dimension from the front wheel center to the driver's tread point, also known as L113 dimension, is the core dimension of the entire vehicle and the foundation of its construction. Its influencing factors involve a wide range, and it needs to be reasonably defined in the conceptual design stage. L113 is generally set as a fixed feature within the same platform. The unification of L113 can achieve standardization of the layout of the front and rear modules of the front bumper, reduce module boundary design variables. The physical boundaries involved in L113 include the layout of the front cabin, the definition of the front bumper position, the definition of the three pedal position, tire selection and envelope, and the boundary of the vehicle structure. The performance involved includes overall vehicle safety performance, human-machine comfort, and ease of entry and exit. This article investigates the influence of physical boundaries and performance requirements on L113, and explores the X-direction distance definition method from the front wheel center to the driver's tread point through the decomposition of three key main cross-sections and dimension chains, for reference.

Key words: L113 dimension; influencing factors; main section; definition methods