Fixture Design Based on the above process plan, we designed two sets of specialized fixtures. Both clamps are mounted on the lathe spindle flange using a 206H7 stop. Clamp 1 is an eccentric clamp, with the 206H7 stop positioned eccentrically relative to the 184h7 boss, ensuring the required eccentricity of the workpiece hole. Clamp 2 is a concentric clamp, designed to meet the coaxiality requirements of the workpiece hole. To ensure that the eccentricity of the workpiece meets the drawing specifications, the eccentricity e of Clamp 1 must be strictly controlled within a certain tolerance.
We set the tolerance for the eccentricity e of Clamp 1 as $e$. The fit between the clamp and the lathe spindle flange positioning surface is 206H7/h6, resulting in a maximum clearance of $1max = 0.075$. The maximum clearance between the workpiece and Clamp 1’s 184H9/h7 surface is $2max = 0.118$. Therefore, the maximum error in the eccentricity of the workpiece is calculated as:
$ \text{max} = e + \frac{1}{2}(1max + 2max) = e + \frac{1}{2}(0.075 + 0.118) = e + 0.0965 $.
Given that $ \text{max} = 0.1 $, substituting into the equation yields:
$ e = 0.1 - 0.0965 = 0.0035 $.
This means the eccentricity of Clamp 1 must be controlled within a range of 12.5 ± 0.05.
Similarly, if the coaxiality error of the workpiece hole is $d$, and the coaxiality error of the two cylindrical locating surfaces (206H7 and 180h7) on Clamp 2 is $f$, then:
$ dmax = f + \frac{1}{2}(1max + 2max) = f + \frac{1}{2}(0.075 + 0.103) = f + 0.089 $.
Assuming $dmax = 0.1$, we get:
$ f = 0.1 - 0.089 = 0.011 $.
Since $f$ is very small, it implies that Clamp 2 must have no significant coaxiality error. To achieve this, we mounted Clamp 2 on the lathe and machined its 180h7 locating surface to eliminate any inherent coaxiality errors, ensuring the workpiece meets the required coaxiality tolerance.
The machining process plan and fixture design we implemented have been validated through practical application. Not only do they guarantee the accuracy of the workpiece, but they also enhance production efficiency. By making full use of existing equipment, we reduced processing costs significantly. This process proves to be convenient, economical, and reliable for manufacturing similar workpieces. 8" Pattern Rubber Roller,Rubber Roller Coating Image,What is Rubber Coating,Rubber Coating for Metal Roller Jiangmen Nichiyo Decorative Material Co.,Ltd. , https://www.nichiyopt.com