Fitter measurement processing method in the digital age

With the development of the modern processing industry, the traditional bench machining method has been difficult to meet the requirements in the digital age. How to use the existing measuring tools, optimize the fitter processing technology, scientifically use the measuring tools, improve the processing efficiency and quality, and no longer rely entirely on processing experience and skills to complete the processing is our research topic. Plates, lever dial gauges, gauge blocks and sine gauges are commonly used gauges. Combining them ingeniously can solve the problem of data acquisition and processing methods in the bench machining process. The following is a combination of these commonly used gauges.

1. Measuring method of workpiece flatness and parallelism

Boring is a commonly used machining method for fitters. When testing the flatness and parallelism of a machined surface, the rule of the workpiece surface and the edge are generally measured using a knife-edge ruler to verify the straightness and flatness of the workpiece. When testing parallelism, measure the distance from the reference surface to the surface being machined. This operation is troublesome and the precision is low. Measurements can now be made using a combination of plates, block gauges and lever dial gauges.

During the measurement, the reference surface of the workpiece to be tested and the height vernier caliper with the lever dial gauge are placed on the flat plate, and the base of the height vernier caliper is moved on the flat plate to observe the change of the value of the lever dial indicator, and the parallel of the workpiece can be checked. Degree and flatness. Using the block gauge as the height standard, the lever dial gauge can measure the data of each point on the surface being machined and compare it with the standard value to obtain the machining allowance (see Figure 1).

2. Workpiece bevel measurement method

The angle of the bevel is a common machining process for the fitter. When machining, the angle is generally measured using a universal square, and the machining accuracy is difficult to guarantee. A combination of sine gauges, lever dial gauges and block gauges is a good solution. By placing the machined workpiece on a sinusoidal gauge that has been rotated at an angle so that it is parallel to the reference plane, it is easy to measure its size, angle, parallelism and flatness, and accurately measure the machining allowance at each point of the machined surface. . The method of measuring the angle and flatness of the inclined plane using the universal square ruler and the knife edge rule was changed (see Fig. 2).

The use of a sine gauge to detect the angle of the workpiece machining surface not only has the advantage of the usual inspection methods in terms of machining accuracy, but also highlights the flexibility of the machining technique and the detection method in other aspects. 1 Place the workpiece on the sine gauge with the adjusted angle. According to the calculated angle of the workpiece to the inspection platform and the calculated value, use the height gauge to scribe the sine gauge directly. In this way, the intersection point of the coordinate line in two directions which is usually used is avoided, and the method of manually connecting two coordinate points by using a scriber and a flat ruler improves the stability of the scribe line precision. 2 It can be processed by the right angle surface of the workpiece or the right angle of the workpiece to face the inner and outer angle surfaces of the workpiece. 3 You can use the lever dial indicator to check the surface at the measured angle, and use the reverse meter to detect when the measurement is restricted (see Figure 3).

In the dovetail fit, the angle measurement is mostly based on the universal angle ruler or angle model. Because the measurement accuracy of the universal angle ruler is not high, the high-precision measurement accuracy requirements cannot be met, so the angle measurement accuracy of the dovetail is difficult to guarantee, thus giving other The measurement of the size has a big impact. The traditional measurement method uses a large number of measuring tools, the measurement operation is complicated, the efficiency is low, and the measurement accuracy is low.

The use of a sine gauge can overcome the above deficiencies one by one, ensuring measurement accuracy requirements. When used in conjunction with the block gauge, the block gauge is used as the standard h1 and h2 measurement values, and the machining allowance of the machined surface can be accurately and conveniently measured. The lever gauge can also be used to measure various parameters of the bevel in the workpiece.

3. Numerical calculation of machined workpiece

When machining the workpiece, take the intersection of the workpiece reference plane as the origin, calculate the coordinates of each machining plane, and use the sine gauge to convert each slope into a plane parallel to the reference plane and calculate the value. During the machining process, the block gauge is used as a reference to measure the value of each point on the machined surface to calculate the machining allowance for each point on the surface. Just like CNC machining, the fitter machining is digitized.

4. Conclusion

Proficiency in the use, calculation and testing process of the measuring tool can achieve fast, accurate and reliable in use, and can meet the processing precision requirements of the workpiece. However, the bench work must be based on solid basic work, with advanced tools, gauges, and reasonable machining processes to process complex and high-precision parts. Skilled fitters can machine parts that are more precise and smoother than those machined by modern machine tools. They can produce very complex parts that cannot be machined with modern machine tools, such as high-precision gauges, prototypes, and complex molds.