Machinery product quality have become increasingly demanding:

       Precision from 0.01mm → 0.005mm- ordinary level

       From 0.1 ~ 0.01μm (nanometer) → 0.001μm- Precision

       Surface quality has been the roughness of less than 0.0005μm.

6.1.1 precision and accuracy of the workpiece obtained

Precision - refers to the parts after machining geometric parameters (size, shape, and location)
The degree of compliance with the part geometry ideal with drawing requirements.

An ideal parts shall meet the following requirements:

Size - part size tolerance midpoint;
Shape - absolutely flat circle, cylinder, cone;
Location - absolutely parallel, perpendicular, coaxial.

Processing error - it is another way to say machining precision machined parts geometry
Geometry parameters of deviation from the ideal part, to the size of the representation.

Precision include:

Dimensional accuracy - the degree of actual size after the machining of parts with consistent ideal size

Shape accuracy - surface of the rear part of the actual geometry of the machining and the ideal geometry
The degree of pertinence

Positional accuracy - the actual position and the ideal location between the rear surface of the part related to the machining
The degree of pertinence

Obtain the dimensional accuracy of the method:

(1) Test cutting method:

Measured by test cutting → → → Try adjusting the cut ... until it is reached processing portions size requirements

Then removal of all.

Features:

1. The time-consuming;

2. the level of operation of the workers;

3. For single-piece production;

4. Adjust the method used to adjust the position of the tool during machining.

(2) sizing tool method:
The method of dimensional accuracy of the surface to be machined with the tool size pieces of direct insurance. Such as: drill,

Reamers, broaches, taps, floating boring knives

Features: 1 spare parts processing size determines the size of the tool;

2. The size of the tool depends on the kind of precision and accuracy.

     (3) Adjustment Act:

Well in advance to adjust the relative position of the tool and the workpiece on the machine, and in a number of parts
This process has always maintained the same position, in order to ensure the size of the part to be machined methods.

         Features: 1. Size stability;

2. Production rate;

3. Decides to adjust the horizontal;

4. Widely used in batch and mass production.

     (4) Automatic control method: This method is only the measuring device, feeding device and control

An automatic control system and other components of the processing system, the processing system according to measure

It means the amount of parts to be processed measurement signal to control the operation of the tool, automatic

Compensation for tool wear and machining errors caused by other factors; to automatically obtain the desired