Study On Checking Fixture Evalation And Structure Optimization Of CF11 Closures

With the development of domestic automobile industry, the local automobile OEM much focuses on the vehicle quality requirements. The quality of Body in White(BIW) and closures is one of the important parts of vehicle quality. The dimension measurement of parts and assemblies is important to ensure the part quality during BIW and closure production process. Though there are many different measurement methods, the traditional checking fixture is still widely used since it is simple structure, easily to use and low manufacture cost. The precision of the checking fixture will affect the accuracy of part measurement. In order to optimize the structure of checking fixture to raise the precision, this study is based on follow aspects:Firstly, introduce the checking fixture structure design process, precision requirements and evaluation method. Analysis the design method and precision of checking fixture base, datum, location and measurement. Meanwhile, the measurement system precision analysis method is noted. Especially introduce how to use Average-Range method to analysis the gauge repeatability and reproducibility.Secondly, evaluate the gauge design structure and precision by 3D analysis software(3DCS). Introduce the basic principle of 3DCS and modeling analysis method. Make the model of checking fixture in the software and then analysis the effects of each component to the gauge measurement precision. Optimize the checking fixture structure to get better measurement precision.Finally, apply the checking fixture structure analysis and optimization method to the CF11 closure checking fixture, through which to raise the checking fixture design accuracy and improve the checking fixture manufacture quality.In short, the paper established the 3D analysis method to evaluate the checking fixture design and optimize the checking fixture structure. It can be achieved the purpose to enhance the design level, reduce the manufacture timing and cost, raise the quality of closure checking fixture.