4. Reduce tool wear
　　 Dongguan CNC processing plant must re-grind the tool before the tool size wear reaches the sharp wear stage
5. Reduce the stress and deformation of the process system mainly from:
　1) Improve the rigidity of the system, especially the rigidity of weak links in the process system;
　2) Reduce the load and its changes: improve the rigidity of the system,
　 ① Reasonable structural design, 1) Minimize the number of connecting surfaces; 2) Prevent local low-stiffness links from appearing; 3) Reasonably choose the structure and cross-sectional shape of foundation parts and support parts.
②Improve the contact stiffness of the connecting surface: 1) Improve the quality of the joint surface between the parts of the machine tool; 2) Preload the machine tool; 3) Improve the accuracy of the workpiece positioning reference surface and reduce its surface roughness value.
③Adopt reasonable clamping and positioning methods to reduce the load and its changes: ①Reasonably select the tool geometry parameters and cutting parameters to reduce the cutting force; ②The blanks are grouped, and the adjustment of the middle blanks is as uniform as possible.
6. Reduce the thermal deformation of the process system
①Reduce the heat of the heat source and isolate the heat source: 1) Use a smaller amount of cutting; 2) Separate the rough and finishing processes when the parts accuracy is high; 3) Separate the heat source from the machine tool as much as possible to reduce the thermal deformation of the machine tool; 4 ) For inseparable heat sources such as spindle bearings, screw nut pairs, high-speed rail pairs, etc., improve the friction characteristics from the aspects of structure and lubrication, reduce heat generation or use heat insulation materials; 5) Use forced air cooling, water cooling, etc. Cooling measures.
②Balanced temperature field: ③Adopt reasonable machine tool component structure and assembly benchmark
1) The Dongguan CNC processing plant adopts a thermally symmetrical structure-in the gearbox, the shafts, bearings, transmission gears, etc. are arranged symmetrically, so that the temperature rise of the box wall can be uniform, and the deformation of the box body can be reduced; 2) Reasonable selection of machine tool parts Assembly benchmark. ④Accelerate the heat transfer balance; ⑤Control the ambient temperature
7. Reduce residual stress
　1. Increase the heat treatment process to eliminate internal stress; 2. Reasonably arrange the process.
4 Reasons for impact
　① Machining principle error
　　 Machining principle error refers to the error produced by processing with approximate blade profile or approximate transmission relationship. Machining principle errors mostly appear in the machining of threads, gears, and complex curved surfaces.
For example, the gear hob used for processing involute gears, in order to facilitate the manufacture of the hob, the Archimedes basic worm or the normal straight profile basic worm is used instead of the involute basic worm, so that the gear involute tooth profile is produced. The error. Another example is when turning a modular worm, because the pitch of the worm is equal to the circumferential pitch of the worm wheel (ie mπ), where m is the modulus and π is an irrational number, but the number of teeth of the matching gear of the lathe is limited, so choose the matching gear At this time, π can only be calculated as an approximate fractional value (π = 3.1415), which will cause the tool to be inaccurate in the forming movement (spiral movement) of the workpiece and cause the pitch error.
　　 Dongguan CNC processing plant In processing, approximate processing is generally used, and on the premise that the theoretical error can meet the processing accuracy requirements ("=10%-15% dimensional tolerance), to improve productivity and economy.
②Adjustment error: The adjustment error of the machine tool refers to the error caused by inaccurate adjustment.
③Machine tool error
　　Machine tool error refers to the manufacturing error, installation error and wear of the machine tool. Mainly include the guide error of the machine tool, the rotation error of the spindle of the machine tool, and the transmission error of the machine tool transmission chain.
　Machine tool guide rail guide error
　　1. Guide rail guidance accuracy-the degree of conformity between the actual movement direction of the auxiliary moving parts of the guide rail and the ideal movement direction. mainly includes:
　　① The straightness Δy of the guide rail in the horizontal plane and the straightness Δz in the vertical plane (curved);
　　②The parallelism (twist) of the front and rear guide rails;
　　③ The parallelism error or perpendicularity error between the guide rail and the spindle axis of rotation in the horizontal and vertical planes.
　　2. The influence of guideway guidance accuracy on cutting processing mainly considers the relative displacement of the tool and the workpiece in the error-sensitive direction caused by the guideway error. The error sensitive direction during turning is the horizontal direction, and the machining error caused by the guidance error caused by the vertical direction can be ignored; the error sensitive direction during boring processing changes with the rotation of the tool; the error sensitive direction during planing processing is the vertical direction, the bed guide The straightness in the vertical plane causes errors in the straightness and flatness of the machined surface.
Spindle error of machine tool
　　 The machine tool spindle rotation error refers to the drift of the actual rotation axis to the ideal rotation axis. It mainly includes the circular run-out of the spindle end face, the radial circular run-out of the spindle, and the swing of the geometric axis of the spindle.
1. The impact of the spindle end face circle runout on the machining accuracy: ①No effect when machining cylindrical surface; ②When turning and boring the end face, there will be an error in the perpendicularity of the end face to the cylindrical surface or the flatness error of the end face; ③When machining threads, there will be a pitch Period error.
2. The influence of spindle radial circle runout on machining accuracy: ①If the radial rotation error is represented by the simple harmonic linear motion of the actual axis in the y-axis coordinate direction, the hole bored by the boring machine is an elliptical hole, and the roundness error is Radial circle runout amplitude; while the hole produced by the lathe has no effect; ②If the geometric axis of the spindle moves eccentrically, a circle with a radius of the distance from the tool tip to the average axis can be obtained regardless of turning or boring.
3. The influence of the swing of the geometric axis of the spindle on the machining accuracy: ①The conical trajectory of the geometric axis with a certain cone angle in space relative to the average axis is equivalent to the geometric axis moving eccentrically around the average axis from each section. The eccentricity values are different everywhere in the axial view; ②The geometric axis swings in a certain plane, which is equivalent to the actual axis moving in a simple harmonic linear motion in a plane from the cross-section view, but the beating amplitude is different everywhere in the axial view; ③In fact, the inclination swing of the geometric axis of the spindle is a superposition of the above two.
　　 Transmission error of machine tool transmission chain
　　The transmission error of the machine tool transmission chain refers to the relative movement error between the transmission elements at the head and the end of the transmission chain.
　　④ Manufacturing error and wear of fixture
The error of the fixture mainly refers to: 1) the manufacturing error of the positioning element, the tool guide element, the indexing mechanism, the clamping body, etc.; 2) the relative dimensional error between the working surfaces of the above various elements after the fixture is assembled; 3) the fixture in use Wear and tear on the working surface.
⑤ Manufacturing error and wear of the tool
　　The influence of tool error on machining accuracy varies according to the type of tool.
　　1) The dimensional accuracy of fixed-size tools (such as drills, reamers, keyway milling cutters and round broaches, etc.) directly affects the dimensional accuracy of the workpiece.
　　2) The shape accuracy of forming tools (such as forming turning tools, forming milling cutters, forming grinding wheels, etc.) will directly affect the shape accuracy of the workpiece.
　　3) The blade shape error of the generating tool (such as gear hob, spline hob, gear shaping tool, etc.) will affect the shape accuracy of the machined surface.
　　4) For general tools (such as turning tools, boring tools, milling cutters), their manufacturing accuracy has no direct effect on the machining accuracy, but the tools are easy to wear.
　　⑥The process system is deformed by force
The process system of Dongguan CNC processing plant will deform under the action of cutting force, clamping force, gravity and inertial force, thereby destroying the mutual positional relationship of the components of the adjusted process system, leading to the generation of machining errors and affecting Stability of the processing process. Mainly consider the deformation of the machine tool, the deformation of the workpiece and the total deformation of the process system.
　　The influence of cutting force on machining accuracy
　　Only consider the deformation of the machine tool. For the machining of shaft parts, the machine tool is deformed under the force to make the processed workpiece be a saddle shape with thick ends and thin middle, that is, a cylindricity error occurs. Only the deformation of the workpiece is considered. For machining shaft parts, the workpiece is deformed under a force so that the workpiece becomes a drum shape with thin ends and thick middle. For machining hole parts, the deformation of the machine tool or workpiece is considered separately, and the shape of the workpiece after machining is opposite to the processed shaft parts.
　　The effect of clamping force on machining accuracy
　　 When the workpiece is clamped, due to the low rigidity of the workpiece or the improper clamping force, the workpiece will be deformed correspondingly, which will cause machining errors.
　　⑦The thermal deformation of the process system
　　During the machining process, due to the internal heat source (cutting heat, friction heat) or external heat source (ambient temperature, thermal radiation), the process system is heated and deformed, which affects the machining accuracy. In the processing of large workpieces and precision processing, the processing error caused by the thermal deformation of the process system accounts for 40%-70% of the total processing error.
　　The effect of workpiece thermal deformation on processed gold includes two types: uniform heating of the workpiece and uneven heating of the workpiece
　　⑧ Residual stress inside the workpiece
　　 The generation of residual stress: 1) Residual stress generated in the process of blank manufacturing and heat treatment; 2) Residual stress caused by cold straightening; 3) Residual stress caused by cutting process.
　　⑨Environmental impact of processing site
There are often many small metal chips at the processing site of Dongguan CNC processing plants. If these metal chips are located on the positioning surface or positioning hole of the part, they will affect the machining accuracy of the parts. For high-precision machining, some metal chips that are too small to be visible will affect the machining accuracy. To accuracy. This influencing factor will be identified but there is no adequate method to eliminate it, and it often relies heavily on the operator's working methods.