Precision parts machining is mainly used to machine some very high precision parts. These parts are used in different application industries. The precision of precision parts machining will directly affect the measurement parameters. Measuring accuracy can be used according to different situations. Methods to operate, so what are the measurement methods of precision parts machining accuracy?
Precision parts processing according to whether the reading value of the measuring instrument directly represents the value of the measured size, can be divided into measurement and relative measurement.
Absolute measurement: the reading value directly represents the size of the measured dimension, such as measurement with vernier calipers.
Relative measurement: the reading value only represents the deviation of the measured dimension relative to the standard quantity. If the diameter of the shaft is measured with a comparator, the zero position of the instrument should be adjusted with a measuring block before the measurement is made. The measured value is the difference between the diameter of the side shaft and the size of the measuring block, which is the relative measurement value. Generally speaking, the relative measurement is more accurate, but the measurement is more troublesome.
Precision parts processing is divided into contact measurement and non-contact measurement according to whether the measured surface is in contact with the measuring head of the measuring instrument.
Contact measurement: the measuring head is in contact with the surface to be contacted and has a precise measuring force. For example, parts are measured with a micrometer.
Non-contact measurement: the measuring head is not in contact with the surface of the part to be measured. Non-contact measurement can avoid the influence of the measuring force on the measurement results. Such as the use of projection method, light wave interferometry, etc.
Precision parts processing can be divided into direct measurement and indirect measurement according to whether the measurement parameters are measured directly.
Direct measurement: directly measure the measured parameters and get the measured dimensions. For example, using calipers and comparators for measurement. Indirect measurement: The geometric parameters related to the measured dimensions are measured and the measured dimensions are obtained by calculation.
Obviously, for parts processing direct measurement is more intuitive, while indirect measurement is more troublesome. Generally when the measured dimensions or direct measurement cannot meet the accuracy requirements, indirect measurement has to be used.