Tips for processing in mechanical processing plants and causes of errors

The mechanical parts processing industry is a pillar industry of the national economy and has very promising prospects. When processing precision mechanical parts in a mechanical processing plant, there will be many requirements and regulations on the processing technology, and the qualified rate of the factory parts.
Remove the jaws of the vise, and process two M4 threaded holes. Place two 1.5mm thick steel plates 2 flush with the jaws, and rivet a 0.8mm thick hard brass plate with aluminum countersunk rivets 3 Fasten it to the jaws with M4 countersunk screws 1 to form a durable soft jaw. In this way, the hardware parts can be protected from being clamped, and they are interchangeable.

For a workpiece, first clamp and then position, because the workpiece will definitely be deformed during clamping, it should be clamped and then positioned. For 6-point positioning, try to limit its degree of freedom. When the handle of the Allen wrench is short and cannot be applied, the pipe with a slightly larger inner diameter than the wrench can be inserted into the slot from a section of the pipe, which can be used as a long handle.

In the mechanical manufacturing process of the mechanical processing plant, the errors mainly include the spindle rotation error, the guide rail error and the 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 moment, which will directly affect the accuracy of the processed workpiece.

The main causes of spindle rotation error are spindle coaxiality error, bearing error, coaxiality error between bearings, spindle winding, etc. The guide rail is the benchmark for determining the relative positional relationship of various machine tool components on the machine tool, and it is also the benchmark for machine tool movement.

The manufacturing error of the guide rail itself, the uneven wear of the guide rail and the installation quality are important factors that cause the guide rail error. Transmission chain error refers to the error of the relative movement between the transmission elements at both ends of the transmission chain. It is caused by the manufacturing and assembly errors of each component of the transmission chain, as well as the wear during use.

The experience of mechanical processing plants points out that any tool will inevitably wear during the cutting process, and this will cause the size and shape of the workpiece to change. The influence of tool geometry error on machining error varies with the type of tool: when using a fixed-size tool for machining, the tool manufacturing error will directly affect the machining accuracy of the workpiece; for general tools, the manufacturing error has no direct effect on the machining error Influence.

The function of the fixture is to make the workpiece equivalent to the tool and the machine tool have the correct position, so the geometric error of the fixture has a great influence on the machining error (especially the position error). The thermal deformation of the process system has a relatively large impact on the machining error, especially in the precision machining and large parts processing, the machining error caused by the thermal deformation can sometimes account for 50% of the total error of the workpiece.