The dimensional accuracy during part processing directly affects the quality and functionality of the product. In order to obtain high-precision machining dimensions for Dalian automotive parts, we can use the following methods:

1. Process design: Reasonably design the dimensions and tolerances of parts to minimize the impact of machining errors. For parts that require high precision, we can use design expansion, which means that the actual size range required is appropriately enlarged to ensure that the dimensions can be controlled within the tolerance range required by the design during the machining process.

2. Processing equipment: Choose processing equipment with high precision and stable performance. Advanced CNC machining equipment usually has higher control accuracy and stability, which can meet the requirements for high-precision dimensions.

3. Processing technology: Reasonably select processing technology and process parameters to ensure accuracy control during the processing. For example, in CNC milling, high-precision machining can be achieved by reasonably selecting parameters such as cutting speed, feed rate, and cutting depth.

4. Clamping and positioning: Use reasonable clamping and positioning methods to ensure the positional accuracy of the workpiece during the machining process. The rigidity and accuracy of the clamping device are crucial for machining accuracy, as loose or tight clamping can lead to machining errors.

5. Machining tools: Choose high-quality and stable machining tools. The quality and dimensional stability of cutting tools directly affect the accuracy control during the machining process.

6. Processing auxiliary devices: Use auxiliary devices such as workpiece blocks, workpiece fixtures, etc. to assist in processing and improve the accuracy of dimensional processing. For example, in laser cutting, the position accuracy of the workpiece can be ensured by using positioning blocks.

7. Processing environment: Provide a stable processing environment to avoid the impact of environmental factors such as temperature and humidity on the processing size. The physical factors such as temperature and humidity in the processing environment can have a certain impact on the processing accuracy, so reasonable control is necessary in the working environment.

8. Quality inspection and feedback: Conduct real-time quality inspection of part dimensions during the machining process, and promptly detect and correct machining errors. By monitoring and correcting machining errors, process parameters and processes can be adjusted in a timely manner to improve machining accuracy.

9. Personnel technical level: Train and cultivate highly skilled processing personnel to enhance their understanding and understanding of machining accuracy. The technical level of processing personnel plays a crucial role in controlling machining accuracy, and highly skilled personnel can better understand the machining process and process specifications.

10. Continuous optimization and improvement: Processing accuracy is a complex process that requires continuous optimization and improvement to improve. By continuously improving processing techniques, tools, and equipment, gradually improving processing accuracy.

In summary, obtaining dimensional accuracy during part processing requires comprehensive consideration from process design, processing equipment, processing technology, clamping and positioning, processing tools, processing auxiliary devices, processing environment, quality inspection and feedback, personnel technical level, and continuous optimization and improvement. Through scientific and reasonable measures and methods, high dimensional accuracy can be achieved.