When machining precision mechanical parts in mechanical processing factories, there are many requirements and regulations for processing to ensure the qualification rate of the factory parts.

Remove the jaws of the vise and machine two M4 threaded holes. Use two 1.5mm thick steel plates 2 that are flush with the jaws. Rivet 0.8mm thick hard brass plates 3 with aluminum countersunk rivets and fasten them to the jaws with M4 countersunk screws 1, forming a durable soft jaws. This can also protect hardware parts from being pinched and has interchangeability.

For a workpiece, clamp it first and then position it, as it will definitely deform during clamping, so it should be clamped first and then positioned. For 6-point positioning, find a limit to its degree of freedom. When the hexagonal wrench handle is short and cannot exert force, a pipe with an inner diameter slightly larger than the wrench can be milled into a slot to insert the wrench into the slot, which can be used as a long handle.

During the mechanical manufacturing process in a machining factory, errors mainly include spindle rotation error, guide rail error, and transmission chain error. Spindle rotation error refers to the variation of the actual rotation axis of the spindle relative to its average rotation axis at each instant, which directly affects the accuracy of the workpiece being processed.

The main reasons for spindle rotation errors include the coaxiality error of the spindle, the error of the bearings themselves, the coaxiality error between bearings, and the spindle winding. The guide rail is the benchmark for determining the relative position relationship of various machine tool components on a machine tool, and it is also the benchmark for machine tool movement. The manufacturing error of the guide rail itself, uneven wear of the guide rail, and installation quality are important factors that cause guide rail errors. Transmission chain error refers to the relative motion error between the transmission components at the beginning and end of the transmission chain. It is caused by manufacturing and assembly errors in various components of the transmission chain, as well as wear and tear during use.

The experience of machining factories indicates that tool wear is inevitable during the cutting process, which leads to changes in the size and shape of the workpiece. The impact of machining factory errors on machining errors varies depending on the type of tool used: when using fixed size tools for machining, the manufacturing error of the tool directly affects the machining accuracy of the workpiece; For general cutting tools, their manufacturing errors have no direct impact on mechanical processing errors.

The function of a fixture is to ensure that the workpiece is in the correct position of the tool and machine tool, so the geometric error of the fixture has a significant impact on mechanical processing errors (especially positional errors). The thermal deformation of the process system has a significant impact on machining errors, especially in precision machining and large part machining. Sometimes, the machining errors caused by thermal deformation can account for 50% of the total error of the workpiece.