Mechanical parts processing industry is the pillar industry of the national economy, with a very considerable prospect. When machining precision mechanical parts in the machining factory, there will be many requirements and regulations on the processing technology, based on the qualification rate of the factory parts.
Remove the jaw of the vice, machine two M4 threaded holes, and rivet two steel plates 2 with a thickness of 1.5mm, which are flush with the jaw. Rivet a 0.8mm thick brass plate 3 with aluminum countersunk rivets and fasten it to the jaw with M4 countersunk screws 1 to form a durable soft jaw. In this way, the hardware parts can also be protected from being damaged by clamping, and have interchangeability.
For a workpiece, clamp it first and then position it. Because the workpiece deformation will be tested during clamping, clamp it first and then position it. For 6-point positioning, find the degree of freedom that limits it. When the handle of the hexagonal wrench is short and cannot exert force, the wrench can be inserted into the groove from a section of milling groove with a pipe with an inner diameter slightly larger than the wrench, which can be used as a long handle.
In the process of mechanical manufacturing, 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 will directly affect the precision of the workpiece to be processed.
The main reasons for the spindle rotation error are the coaxiality error of the spindle, the error of the bearing itself, the coaxiality error between bearings, and the spindle winding. The guide rail is the benchmark for determining the relative position of each machine tool component on the machine tool, and 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 causing the guide rail error. Transmission chain error refers to the relative motion error between 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 in the use process.
The experience of machining manufacturers points out that any tool will inevitably wear in the cutting process, which will cause changes in the size and shape of the workpiece. The influence of geometric errors of cutting tools on machining errors varies with the types of cutting tools: the manufacturing errors of cutting tools will directly affect the machining accuracy of workpieces when using fixed size cutting tools; For general tools, the manufacturing error has no direct impact on the machining error.
The function of the fixture is to make the workpiece have the correct position equivalent to the cutter and machine tool, 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 great influence on the machining error, especially in precision machining and large workpiece machining. The machining error caused by thermal deformation sometimes accounts for 50% of the total error of the workpiece.
