Research On Automatic Measurement Technology Of Pitch Diameter For The Rzeppa Joint Housing Raceways

Constant Velocity joints (CV joints) are widely used in the passenger cars as flexible couplings between wheels and axle shafts. Rzeppa CV joint, which is a type of CV joints, is mainly assembled by inner race, cage, balls and housing. The machining process of shaping the inner race & housing circular raceways is complex, so it's hard to make the circular raceways exactly the same size. Assembling quality can be increased a lot by measuring the pitch diameter of inner race & housing circular raceways first, then selecting suitable parts to assemble the Rzeppa CV joints. In order to match the requirement of massive manufacturing task, and improve the products assembling quality, it's very necessary to develop an high-precision automatic technology that can measure the pitch diameter of housing circular raceways. For the purpose of developing that kind of technology with high-precision and efficiency, an measuring instrument is designed based on the 2-points & 3-points measuring methods.The 2-points & 3-points measuring methods have been discussed at the beginning of this paper. After analysing the main factors that can reduce measuring accuracy, an measuring instrument system is designed based on 2 kinds of measuring methods,which includes mechanisms and control & measurement system.Mechanisms of this instrument are designed by using the best locating surface and based on 2 kinds of measuring methods, which include the base, axial movement mechanisms, and 2 different measuring mechanisms. The ball shaped measuring heads get axial location and reset by axial movement mechanisms. Two kinds of radial location of housing that match 2 measuring methods requirement are achieved by measuring mechanisms. All mechanisms movement are driven by air cylinders.The hardware and software design of control & measurement system have been finished based on the mechanisms in this thesis. Measuring movement procedure control is achieved by using PLC to control air cylinders. The communication between PLC and IPC is connected by the I/O interface. PLC informs IPC that data acquisition card should start sampling when measuring movement is finished. The measurement system uses inductance micrometer to generate measuring signals. The measuring signals then get sampled by data acquisition card and processed by IPC(Industrial Personal Computer).The mesuring software is based on virtual instrument technique and programmed by using LabVIEW, which controls the sampling process and data analysis. Measuring parameters can be set on the interface of mesuring software, which displays mesuring results as well.By the end of this paper, an experimental verification is given. The developed measurement system is used to measure all circular raceways diameter of 2 RF95.16 Rzeppa CV joint housing. After analysing the measured data, the results show that the accuracy of the 2-points measuring device is±0.7μm, and its efficiency is about 15s/set, so it matches the design requirement. While the the accuracy of the 3-points measuring device is±5 0.3μm, which is too low to satisfy the measurement requirement, then the influencing factors get analysed.