System error of cutting machine
Hydraulic cutting machine processing parts must be a batch processing, and the size must be kept the same, or these parts are regular changes, such error will be called system error.
Errors of constant magnitude are called constant systematic errors, while systematic errors that keep changing regularly are systematic errors.
For example, using a reamer with a diameter less than 0.02 of the specified size, the diameter of all the holes reamed are 0.02 less than the specified size, and this error is a systematic error.
Full automatic cutting machine
If it is because of tool wear, the diameter of the turning shaft will be larger than one, the increase of the diameter of the shaft is a certain rule, so the error caused by such a situation is the error with regular changes, that is, the change of system error.
Of course, the error caused by heating deformation also belongs to the category of variation system error.
Accidental error of cutting machine
In the process of cutting machine processing a batch of parts, the direction and size of errors have irregular changes, sometimes small and sometimes large, sometimes with time positive, this error is also known as accidental error.
For example, when a four-column cutting machine USES a reamer to process the holes of a batch of parts, under the same conditions, a batch of holes with exactly the same diameter and size can still be obtained. This may be caused by uneven blank hardness, difference in AJJl 'margin, and deformation caused by internal stress redistribution.
Although the cause of accidental error is various, and the function of cutting machine is very complicated, the rule of accidental error can be found by mathematical statistical force method and controlled.