With the rapid development of China's economic construction, the improvement of people's living standards, China's construction industry has developed rapidly, and the demand for aluminum profiles is increasing. Therefore, the demand for production and production of aluminum alloy is also increasing.

Aluminum profile products are widely used in all walks of life, and the products continue to develop towards diversification and complex development, and the processing accuracy requirements for products are also increasing. The extrusion mold is the foundation of the extrusion process, not only, not only, not only the shape, dimensional accuracy and surface state of the extruded product. The quality requirements are getting higher, and the processing requirements for the mold also increase. Processing accuracy is the maximum requirement of processing, so how to effectively improve the processing accuracy of precision plastic molds has become a difficult problem in today's difficult solution.

1.1 Mold processing quality includes machining accuracy and surface quality

The processing accuracy is the actual size, shape, and the ideal geometric parameters of the surface of the part surface and the ideal geometric parameters required by the drawings. Ideally geometric parameters, for size, the average size; for surface geometry, it is absolute circle, cylindrical, plane, cones and straight lines, etc., is absolutely parallel to each other. Vertical, coaxial, symmetric, etc. The actual geometric parameter of the parts and the ideal geometric parameters are referred to as processing errors.

The machining precision and processing errors are terms that evaluate the surface geometric parameters. The length of the processing precision is measured, the smaller the level value, the higher the accuracy; the number of processing error is represented, the larger the value, the greater the error. High processing accuracy is small processing error, and vice versa.

The actual parameters obtained by any processing method will not be absolutely accurate, from the function of the part, as long as the processing error is within the tolerance range of the parts map, the processing accuracy is considered to ensure processing accuracy.

The quality of the machine depends on the mass processing quality of the parts, the quality of the machine, and the parts of the parts, the surface quality, the two parts of the mechanical processing accuracy refers to the actual geometric parameters (size, shape and location) and the ideal geometry after the processing of parts. The degree of parameter is in line with. The difference between them is called processing errors. The size of the machining error reflects the high processing accuracy. The larger the error, the lower the machining accuracy, the smaller the error, the higher the machining accuracy.

2 Main aspects of impact processing accuracy

2.1 dimensional accuracy

The actual size of the rear part is the degree of matching the gear difference belt center of the part dimension.

Dimensional accuracy is controlled with dimension tolerances. Size tolerances is the amount of variation allowed in part dimensions in cutting. In the same case of the basic size, the dimensional tolerance is smaller, and the higher the dimensional accuracy is higher.

2.2 Shape Accuracy

The actual geometry of the surface of the machined parts is in line with the ideal geometric shape. The items of the measurement of shape accuracy have 6 straightness, flatness, roundness, cylindrical, line profile, etc. The shape accuracy is controlled by the shape tolerance, each shape tolerance, in addition to the roundness, the cylindrical score, and the remaining units are 12 precipitation levels. Level 1, the lowest level 12.

2.3 Position Accuracy

Refers to the difference in actual position accuracy between the surface. The items of the assessment of positional accuracy have eight items such as parallelism, verticality, inclination, coaxial degree, symmetrical degree, position degree, circular jam and full beating. The positional accuracy is controlled by position tolerance, and the positional tolerances of each item are also divided into 12 precision levels.

3 dimensional accuracy, shape precision and positional accuracy

When designing machine parts and specified parts processing accuracy, it should be noted that the shape error is controlled within position tolerances, and the position error should be less than the dimension tolerance. That is, the important surface of the precision parts or part, its shape accuracy should be higher than the positional accuracy requirements, and the positional accuracy requirements should be higher than the dimensional accuracy requirements.