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Skills of CNC Turning Thin-walled Parts

Mar. 05, 2020

In the process of NC turning, the thin wall is easily deformed by the cutting force, which leads to the phenomenon of "ellipse" with ellipse or small middle and large two ends. In addition, thin-walled sleeves are prone to thermal deformation due to poor heat dissipation during processing, and it is not easy to guarantee the processing quality of parts. Not only are the parts inconvenient to clamp, but also the processing parts are difficult to process, a special thin-walled sleeve and shaft guard need to be designed. The following CNC Turning Motorcycle Parts Exporter will come to tell you the skills of CNC turning thin-walled parts.

CNC Turning

CNC Turning

1. Process analysis

According to the technical requirements provided in the drawings, the workpiece is processed by seamless steel tubes, which can be achieved by CNC Turning, and the requirements for thin-walled parts are relatively high. In mass production, the process route is roughly: blanking-heat treatment-car end face-car outer circle-car inner hole-quality inspection. "Inner hole processing" process is the key to quality control. It is difficult to guarantee a cylinder of 0.03mm when we cut the inner hole without the outer circle and thin-walled sleeve.

2. The key technology of the car hole

The key technology of turning is to solve the problems of rigidity and chip removal of inner turning tools. To increase the rigidity of the hole turning tool, take the following measures:

(1) Increase the cross-sectional area of the shank as much as possible. Usually, the tip of the inner hole turning tool is located on the top of the shank, so the cross-sectional area of the shank is less and less than 1/4 of the hole cross-sectional area. If the tip of the inner hole turning tool is located on the center line of the shank, the cross-sectional area of the shank in the hole can be greatly increased.

(2) The extended length of the tool holder can be as long as the length of the workpiece being processed, which is 5-8mm, to increase the rigidity of the tool holder and reduce the vibration during the cutting process.

3. Solve the problem of chip removal

The main control is the cutting outflow direction. The rough turning tool requires the chips to flow to the surface to be processed (front chip). For this purpose, a positive-angle inclination internal turning tool is used. When finishing turning, the chips are required to flow to the center to discharge chips (hole chip removal). Therefore, when sharpening the knife, pay attention to the cutting direction of the cutting edge and the method of chip removal to the front. The bending strength, Abrasion resistance, impact toughness, and resistance to steel and temperature are all good.

4. Processing method

(1) A shaft must be protected before processing. The main purpose of the shaft protection is to cover the inner hole of the finished thin-walled sleeve with the original size, and fix it with the front and rear centers so that it can process the outer circle without deformation, and maintain the quality and accuracy of the outer circle processing. Therefore, the processing of the shaft guard is a key link in the process of processing thin-walled casing.

(2) In order to allow the workpiece to be processed at one time, the blank will be clamped and cut off.

(3) The hair embryo is first subjected to heat treatment, tempering and setting.

(4) First put the front tip into the spindle cone position and fix it. In order to prevent deformation of the workpiece when clamping the thin-walled sleeve, an open-loop thick sleeve is added.

In order to maintain mass production, the outer end of the thin-walled sleeve is processed to a uniform size d, and the ruler of t is an axial clamping. The thin-walled sleeve is compacted to improve the quality of the inner hole of the car and maintain the size. Considering the generation of cutting heat, it is difficult to grasp the size of the workpiece expansion. Need to pour sufficient cutting fluid to reduce thermal deformation of the workpiece.

The above method for processing thin-walled sleeves solves the problem of deformation or dimensional and shape errors that do not meet the requirements. Practice has proved that the processing efficiency is high, easy to operate, and suitable for processing long thin-walled parts. The size is easy to grasp. It is completed in a second time and mass production is more practical.