Processing accuracy refers to the degree to which the actual geometric parameters (size, shape, position) of the parts processed during the processing of Dalian auto parts match the ideal geometric parameters specified in the drawings. The higher the fitting degree, the better the processing accuracy. Then how to determine the dimensional accuracy of Dalian auto parts??

1. Trial cut method

That is, first cut a small part of the worktable, measure the size obtained by trial cutting, adjust the position of the cutting edge of the tool relative to the workpiece according to the working conditions, and then cut. Generally, after 2-3 test cuts and measurements, the required size can be achieved.

The precision of the trial cutting method is very high, and no complex equipment is required. However, this method is time-consuming (it requires multiple adjustments, test cutting, measurement and calculation), inefficient, and requires manual operation. The quality is unstable, depending on the technical level and accuracy of the measuring instrument. Therefore, it is only used for single piece and small batch production.

The trial cutting method is often used in conjunction with other methods.

2. Adjustment method

The exact relative positions of machine tools, jigs, tools and workpieces are pre adjusted with samples or standard parts to ensure the dimensional accuracy of workpieces. Because the size is adjusted in advance, there is no need to cut during processing. The size is automatically taken, and the parts are not changed during batch processing. This is an adjustment method. For example, when using the milling machine holder, the tool setting block determines the position of the tool. The essence of the adjustment method is to use the fixed range device or tool setting device of the machine tool and fixture to make the machine tool and fixture reach a certain position accuracy and complete the processing at one time.

Cutter feeding is also a cutting method, which follows the dial. This method first needs to determine the scale on the dial according to the trial cutting method. In mass production, tool setting devices such as aperture, sample and template within a certain range are often used for adjustment.

The adjustment method has better processing accuracy, stability and higher production efficiency than the trial cutting method. It does not require a machine tool, but requires a high level of machine tool regulators. It is commonly used in batch production and mass production.

3. Sizing method

The method of using the corresponding tool size to ensure the size of the workpiece to be processed is called sizing method. This is handled by standard size tools, and the size of the machined surface is determined by the size of the tool. That is, tools with certain dimensional accuracy (reamer, reamer, drill, etc.) are used to ensure the machining accuracy of the workpiece (such as holes).

The sizing method has the advantages of simple operation, high production efficiency and relatively stable machining accuracy. It has nothing to do with the technical level of workers and is highly productive. It is widely used in all kinds of production. Drilling, trimming, etc.

4. Active measurement

In the process of processing, it is an active measurement method by measuring the processing size during processing and comparing the measurement results with the size required by the design, or by operating or stopping the machine tool

At present, the value of activity measurement can be displayed digitally. The active measurement method adds measuring devices to the process system (i.e. the integration of machine tools, tools, fixtures and workpieces), which is the fifth factor.

The active measurement method has stable quality and high productivity, which is the development direction.

Automatic control mode

The method consists of measuring device, feeding device and control system. This is an automatic processing system composed of measurement, feeder and control system. The processing process is automatically completed by the system.

Automatically complete a series of tasks, such as dimension measurement, cutter compensation adjustment, cutting and machine tool shutdown, to achieve the required dimensional accuracy. For example, when machining on a CNC machine tool, the processing sequence and accuracy are controlled by various instructions of the program.