细长轴的加工（Machining of slender shafts）.docVIP

细长轴的加工（Machining of slender shafts） The part length L/ diameter D20 is called the slender shaft, its processing characteristic: 1, the poor rigidity, in the cutting force and gravity, bending deformation, and vibration, affecting the machining accuracy and surface quality 2, the thermal deformation of large length, easy to bend the workpiece deformation, resulting in centrifugal force, accelerated bending deformation 3, at high speed feeding, the tool is easy to wear, thus affecting the machining accuracy and surface quality The following measures are usually adopted: 1, to improve the workpiece clamping method: such as an open ring, or the end of the center into a spring automatic expansion of the living center, or use 3 support block with the tool post. 2 change the feed direction of the tool and change the pressure to the pull 3, improve tool feed parameters, such as increasing the main deflection angle, using the negative edge angle, etc.. 4, reduce the amount of cutting 5, fully cooling lubrication 1, slender shaft material generally use 40Cr 2. After heat treatment, hydraulic straightening must be performed 3, after half fine car, boil oil qualitative Before 4, the outer round grinding, grinding to the center hole 5, after finishing the work, must be suspended, stored in the shade Standard Specification for round steel stock: Small round specifications large round specifications 40Cr: carbon medium steel, cold heading die steel. The steel is moderate in price and easy to process. After proper heat treatment, it has certain toughness, plasticity and wear resistance. Normalizing can promote the spheroidization of tissue and improve the cutting performance of the blank with hardness less than 160HBS. The steel has the best comprehensive mechanical properties at tempering temperature 550~570 degrees centigrade. The hardenability of the steel is higher than that of 45 steel. It is suitable for high frequency hardening, flame hardening and other surface hardening tr