Introduction to the automatic turning process of slender shaft
What is the elongated shaft?
An axial type workpiece having a ratio of the length L to the diameter d of the workpiece greater than 25 (i.e., the long neck ratio L/d > 25) is referred to as an elongated shaft. The shape of the slender shaft is not complicated, but due to its low rigidity, it is affected by cutting force, gravity, cutting heat and other factors during turning. It is prone to bending deformation and defects such as vibration, taper, waist drum shape, and bamboo shape. It is difficult to ensure accuracy, or even can not be processed. Although the slender shaft is difficult to machine, it has the commonality of machining ordinary workpieces (such as cutting method, workpiece installation, turning selection and clamping); Choose to process a variety of high-quality shaft parts to look for Kang Ding hardware. This paper discusses some difficulties and solutions in the process of slender shaft turning: Grasping the commonality of turning, combined with the individuality of the slender shaft, solving three key technologies such as stiffness, thermal deformation elongation and reasonable selection of the geometric parameters of the turning tool, the turning of the slender shaft is also handled smoothly.
First, the problems encountered in the process of slender shaft turning
The slender shaft is poor in rigidity, and the process system using the machine tool, the tool, the jig, and the workpiece is insufficient in rigidity, and vibration deformation is easily generated during cutting, which causes processing difficulty. The main problems encountered during processing are:
1. The workpiece is subjected to cutting resistance to generate vibration and bending deformation, which reduces geometric accuracy and surface finish.
2. The cutting heat absorbed by the workpiece during the cutting process will cause the workpiece to have a large axial line expansion, aggravate the bending deformation, increase the vibration, and even cause the workpiece to squash between the two tips, resulting in inability to process.
3. The longer the ratio of long neck to neck, the greater the self-gravity, the greater the centrifugal force generated by the workpiece at high speed, and the upper and lower jumps will seriously affect the processing quality.
4. The improper selection of the geometric angle of the tool, the amount of cutting and the processing method will increase the cutting force, and the deformation and vibration will be intensified.
5, the workpiece bending and vibration, the turning must use a lower speed and depth of cut, limiting the increase in production efficiency.
5, the workpiece bending and vibration, the turning must use a lower speed and depth of cut, limiting the increase in production efficiency.
6. Under the action of radial cutting force, the workpiece shape is easy to form small ends and large in the middle, and it is easy to produce a " Breaking Edge" phenomenon.
7, improper adjustment of the machine tool, easy to produce cone error; improper adjustment of the fixture, easy to cause bending and produce "
Bamboo-shaped", "rhombus" and so on.
Second, the measures to solve the problem
In production practice, in order to ensure the machining accuracy and surface quality of the slender shaft and improve production efficiency, we have taken the following measures:
1. In order to compensate for the lack of rigidity of the slender shaft, in the turning, the tool holder should be used to improve the rigidity of the workpiece and reduce the deformation.
2, pay attention to the specific operating methods, there are strict process requirements and measures to ensure the rigidity of the entire process system, so that the workpiece to obtain the necessary geometric accuracy and surface finish.
3. Turning from left to right in the opposite direction; reducing internal stress and bending deformation, ensuring straightness and dimensional accuracy, high processing efficiency and strong adaptability.
4. Reasonable selection of cutting amount, as well as tool geometry and parameters.
An axial type workpiece having a ratio of the length L to the diameter d of the workpiece greater than 25 (i.e., the long neck ratio L/d > 25) is referred to as an elongated shaft. The shape of the slender shaft is not complicated, but due to its low rigidity, it is affected by cutting force, gravity, cutting heat and other factors during turning. It is prone to bending deformation and defects such as vibration, taper, waist drum shape, and bamboo shape. It is difficult to ensure accuracy, or even can not be processed. Although the slender shaft is difficult to machine, it has the commonality of machining ordinary workpieces (such as cutting method, workpiece installation, turning selection and clamping); Choose to process a variety of high-quality shaft parts to look for Kang Ding hardware. This paper discusses some difficulties and solutions in the process of slender shaft turning: Grasping the commonality of turning, combined with the individuality of the slender shaft, solving three key technologies such as stiffness, thermal deformation elongation and reasonable selection of the geometric parameters of the turning tool, the turning of the slender shaft is also handled smoothly.
The slender shaft is poor in rigidity, and the process system using the machine tool, the tool, the jig, and the workpiece is insufficient in rigidity, and vibration deformation is easily generated during cutting, which causes processing difficulty. The main problems encountered during processing are:
1. The workpiece is subjected to cutting resistance to generate vibration and bending deformation, which reduces geometric accuracy and surface finish.
2. The cutting heat absorbed by the workpiece during the cutting process will cause the workpiece to have a large axial line expansion, aggravate the bending deformation, increase the vibration, and even cause the workpiece to squash between the two tips, resulting in inability to process.
3. The longer the ratio of long neck to neck, the greater the self-gravity, the greater the centrifugal force generated by the workpiece at high speed, and the upper and lower jumps will seriously affect the processing quality.
4. The improper selection of the geometric angle of the tool, the amount of cutting and the processing method will increase the cutting force, and the deformation and vibration will be intensified.
5, the workpiece bending and vibration, the turning must use a lower speed and depth of cut, limiting the increase in production efficiency.
5, the workpiece bending and vibration, the turning must use a lower speed and depth of cut, limiting the increase in production efficiency.
6. Under the action of radial cutting force, the workpiece shape is easy to form small ends and large in the middle, and it is easy to produce a " Breaking Edge" phenomenon.
7, improper adjustment of the machine tool, easy to produce cone error; improper adjustment of the fixture, easy to cause bending and produce "
Bamboo-shaped", "rhombus" and so on.
Second, the measures to solve the problem
In production practice, in order to ensure the machining accuracy and surface quality of the slender shaft and improve production efficiency, we have taken the following measures:
1. In order to compensate for the lack of rigidity of the slender shaft, in the turning, the tool holder should be used to improve the rigidity of the workpiece and reduce the deformation.
2, pay attention to the specific operating methods, there are strict process requirements and measures to ensure the rigidity of the entire process system, so that the workpiece to obtain the necessary geometric accuracy and surface finish.
3. Turning from left to right in the opposite direction; reducing internal stress and bending deformation, ensuring straightness and dimensional accuracy, high processing efficiency and strong adaptability.
4. Reasonable selection of cutting amount, as well as tool geometry and parameters.
