A Comprehensive Guide to Machining Processes

A Comprehensive Guide to Machining Processes!

1. What are the three methods for clamping machined parts?

1. Clip the fastener onto the clamp. Use a suit clip if needed. 3. Mark the line to align the straightening pliers.

2. What does the process system include?

{Machine tools, workpieces, fixtures, cutting tools}

3. What is the process composition of machined parts?

{Roughing, Semi-finishing, Finishing, Ultra-precision Machining}

4. What is the benchmark classification method?

{1. Design Standards 2. Process Standards: Processes, Measurement, Assembly, Positioning: (Existing, Added): (Thickness Standards, Precision Standards)}

What does the precision of machined parts include?

{1. Dimensional accuracy 2. Appearance accuracy 3. Positional accuracy}

5. What specific types of initial errors occur during the machining process?

{Principle error, positioning error, adjustment error, tool error, fixture error, machine spindle rotation error, machine guide rail alignment error, machine transmission error, process system force deformation, process system thermal deformation, tool wear, measurement error, and errors caused by residual stresses in the workpiece}

6. How does the stiffness of the machining system affect machining accuracy (due to mechanical deformation and workpiece deformation)?

1. Workpiece shape errors caused by changes in the point of application of cutting forces 2. Machining errors resulting from variations in cutting force magnitude 3. Machining errors induced by clamping forces and gravitational effects 4. The impact of dynamic and inertial forces on machining accuracy

7. What do machine tool guideway errors and spindle rotation errors include?

1. The rail primarily involves relative displacement errors between the rail and the tool or workpiece, particularly in directions sensitive to error. 2. Spindle radial runout, axial runout, tilt, and oscillation.

8. What is the "error remapping" phenomenon? And what is the error remapping coefficient? To minimize error replay, what measures can be taken?

Due to variations in deformation caused by process system errors, the blank error is partially reflected in the workpiece dimensions. Measures to address this include increasing the number of toolpaths, enhancing the stiffness of the process system, reducing the feed rate, and improving the accuracy of the blank.

9. Analysis of Machine Tool Drive Chain Transmission Failures? Measures to Reduce Transmission Chain Transmission Errors?

{Error Analysis: This involves measuring using the angular errors of the end components in the transmission chain.

Measures: 1. The fewer the number of transmission chains, the shorter and smaller the transmission chain, resulting in higher accuracy. 2. The lower the transmission ratio I, especially at the first-stage end, the better. 3. Errors at the ends of transmission components have a significant impact; therefore, precision should be maximized wherever possible. 4. Use compensation devices.

10. How are machining errors classified? Which errors belong to constant-value errors? Which ones fall under variable systematic errors? And which errors are considered random errors?

{System Error: (Constant system error variable system error) Random error

Systematic error in constant-value systems: machining errors caused by factors such as machining principle errors, manufacturing inaccuracies in machinery, tools, and fixtures, as well as force-induced deformations within the process system.

Systematic error due to changing values: Wear of tools; thermal deformation errors of cutting tools, fixtures, machine tools, etc., before thermal equilibrium is reached

Random errors: errors from blank manufacturing, positioning errors, strengthening errors, errors due to multiple adjustments, and deformation errors caused by residual stresses.

11. How can we ensure and improve the machining accuracy of machined parts?

Error-proofing technology: Properly utilizing advanced processes and equipment to directly reduce, average, and homogenize original errors during error transmission.

2. Error Compensation Technology: Online detection of dolls automatically adjusts for wear, playing a decisive role in addressing error factors.

12. What does the geometric pattern of a machined surface include?

{Geometric roughness, surface waviness, texture direction, surface defects}

13. What do the physical and chemical properties of surface materials include?

1. Cold hardening of the surface layer metal 2. Metallurgical structure deformation of the surface layer metal 3. Residual stresses in the surface layer metal

14. Analyze the factors that influence cutting surface roughness.

{Rough Value: Primary factor affecting the height of the remaining cutting area—tool tip arc radius and main inclination angle; Secondary factors—increasing cutting speed, selecting appropriate cutting fluid, increasing the rake angle of the tool, and improving the cutting quality of the tool.}

15. Do you want to analyze the factors that influence grinding surface roughness?

Geometric factors: The influence of grinding parameters on surface roughness². The effects of wheel grit size and wheel dressing on surface roughness². Influence of physical factors: Plastic deformation of surface metal; selection of grinding wheels.

16. Analyze the factors influencing cold work hardening on the surface of cut parts?

The Influence of Cutting Depth on Tool Geometry and Machining Material Properties

17. What is grinding burn from regrinding? What is grinding burn from quenching? And what is grinding burn from tempering?

{Tempering: If the temperature in the grinding zone does not exceed the phase transformation temperature of quenched steel but surpasses the martensite transformation temperature, the martensite in the metal surface will transform into a lower-hardness tempered structure. However, when the temperature in the grinding zone exceeds the phase transformation temperature, secondary-quenched martensitic structures will appear on the surface metal. Combined with the cooling effect of the coolant, these structures will exhibit higher hardness than the original martensite. In the layers beneath, the slower cooling rate leads to the degradation of a tempered structure that is softer than the original tempered martensite. Finally, if the temperature in the grinding zone surpasses the phase transformation temperature and no coolant is applied during the grinding process, the surface metal will develop an annealed microstructure, causing a sharp drop in its hardness.}