Drive shaft in the role of auto parts is still very powerful, not to be underestimated. In the engine front rear wheel drive (or all-wheel drive) car, due to the car in the process of movement of suspension deformation, the drive shaft main reducer input shaft and transmission (or transfer box) between the output shaft often have relative movement. The quality of the drive shaft directly affects the safety of the car. The quality inspection of drive shaft forgings generally includes three aspects: one is dimensional accuracy; Second, surface roughness; Third, shape and position accuracy.

(1) the measurement of the dimensional accuracy of shaft parts for the drive shaft, the dimensional accuracy is high, is not complex, except for the screw thread, with general measuring means can be completed. The main measuring tools are vernier calipers, screw micrometers, thread micrometers or thread plug gauges.

(2) surface roughness measurement parts surface roughness requirements are high, with the surface roughness measuring instrument for measurement, and forgings surface roughness requirements are not high, such as KA0.4 below, with the surface roughness contrast sample.

(3) shape and position accuracy measurement shape and position accuracy measurement is the most important in machining, but also the most difficult, some can not rely on the instrument to measure, the need for auxiliary tools. To understand how shape and position accuracy are measured, it is important to know what indicators of shape accuracy and position accuracy are available. The shape precision of mechanical parts mainly refers to the requirements of a single element, and has nothing to do with other points, lines and planes, such as straightness, roundness, flatness and cylindricity. The position accuracy of mechanical parts mainly refers to the relationship between two and more than two kinds of elements, such as parallelism, verticality, inclination, position, coaxiality, symmetry, circular runout, total runout eight kinds. There are two kinds of requirements that can refer to a single element or a variety of elements, such as line profile and surface profile, etc.

The circular runout of each surface is the main requirement of shaft shape and position accuracy. Measurement, a kind of method is at the center of the forgings at the ends of the hole in the deflection gauge on the top of the dial indicator (high precision with a dial gauge) of the probe and the workpiece measurement of surface contact, (two points, should pay attention to is the probe and the workpiece measuring vertical surface, the other point, the amount of precompression probe not too much, usually around 0.2 _). In the absence of a yaw meter can be used in the second method, that is, the use of the lathe for machining the two centers for measurement, the measurement method is similar to the first.