Measurement error classification – computer gong processing

When manufacturing large batch parts, there are many factors that affect the accuracy of the data in the measurement process. The following small series for us to introduce the measurement error, measurement error can be divided into three categories: random error, systematic error, gross error.

1. Random error. Under the same condition, the size and direction of the error change when measuring the same measurement, and there is no change rule, this kind of error is random error. The causes of the random errors are the gap and deformation of the measuring instrument, the change of the measuring force, and the judgment error of the visual measurement or estimation. The elimination method is mainly from the source of the error to eliminate (reduce the temperature fluctuation, control measurement force, etc.), but also according to the normal distribution probability budget random error size.
2. System error. Under the same conditions, the size and direction of errors in repeated measurement of the same measurement remain unchanged. Maybe when the measurement conditions change, the errors change according to certain rules. This kind of error is a system error. The causes of system errors include inaccurate calibration of measuring tools or measuring instruments, errors in proofreading of measuring tools or measuring instruments, and the ambient temperature is not at 20 ℃ during fine measurement. There are several ways to eliminate system errors. Before measurement, it is necessary to verify all measuring instruments, which should be corrected according to regulations to eliminate errors. Dongguan high speed computer gong processing, to ensure that the scale alignment zero, it is necessary to measure before carefully checking measuring tools to ensure the accuracy of the requirements.
3. Gross error. Gross errors are errors that obviously distort the measurement results. The reason for this kind of error is that the measuring staff will not concentrate and ignore the carelessness, such as reading error, recording error, calculation error, and other abnormal disturbing factors from the outside world. Measurement values with gross errors are called bad values, which probably need not be eliminated.
4. The oxide scale of the parts shall be removed. There shall be no scratch, scratch and other defects on the surface of the parts, and the burr and flash shall be removed;
5. After quenching and tempering, the parts are subjected to high-frequency quenching, tempering at 350-370 ℃, hrc40-45, carburizing depth of 0.3mm, and high-temperature aging treatment.
6. The undeclared shape tolerance should meet the requirements of gb1184-80, the allowable deviation of undeclared length dimension is ± 0.5mm, and the casting tolerance zone is symmetrical to the basic dimension configuration of the blank casting;
7. The fillet radius R5 is not noted, the chamfer is 2 × 45 ° and the acute angle is blunt;
8. The temperature shall not exceed 100 ℃. After the gear is assembled, the contact spot and backlash on the tooth surface shall comply with the provisions of GB10095 and gb11365;
9. When assembling the hydraulic system, it is allowed to use sealing filler or sealant, but it should be prevented from entering the system. The parts and components (including purchased parts and outsourcing parts) that enter the assembly must have the qualification certificate of the inspection department before they can be assembled.