How to choose the Conventional Lathe cutting quantity
1. Selection principle of cutting dosage
In nc programming, the programmer must determine the cutting amount of each process, Conventional Latheincluding spindle speed, back feeding knife, feed speed, etc., and input into the program in the format specified by the numerical control system. For different machining methods, different cutting amount should be used. Reasonable choice of cutting dosage, the surface quality, precision and processing efficiency of the parts are very influential. This is difficult to master in practice, and it takes a lot of practical experience to determine the appropriate cutting amount. Conventional Lathe Can only rely on programmers in CNC programming experience and the cutter cutting dosage recommended value determined primarily, but in the final cutting dosage according to parts for CNC program debugging results and the actual situation to determine.
The selection principle of cutting consumption is: to improve the productivity in rough processing, while taking into account the economic and processing costs; Conventional Lathe During semi-finishing and finishing, the machining quality of parts should be ensured while cutting efficiency and processing cost should be taken into account. It is worth noting that the cutting parameter (spindle rotation, cutting depth and feed) is an organic whole, to adapt to each other, only three at the most reasonable matching values, to get the best cutting parameter. Determine the cutting dosage should be according to the nature of the processing, the processing requirements, the size and material properties of the workpiece material and tool of specific requirements, through the consult the manual cutting and combining with the experience to determine, determining cutting parameter in addition to follow the general principles and methods, should also consider the following factors: (1) tool difference, the influence of different cutting tool manufacturer production tooling quality difference is very big, so the cutting parameter to modify it according to the practical use knives and field experience. (2) Conventional Lathe influence of machine tool characteristics -- the cutting performance is subject to the power of CNC machine tool and the rigidity of the machine tool,Conventional Lathe which must be selected within the scope of the machine tool specification. Avoid the phenomenon of stuffy car due to the lack of power of the machine tool or the vibration of the machine, which affects the machining quality, precision and surface roughness of the parts. (3) the influence of the CNC machine productivity, high cost of nc machine tool's working hours, relatively speaking, low proportion of the wastage of the cutting tool cost, should try to use high cutting parameter, through appropriate to reduce the knives' service life to improve the productivity of CNC machine tools.
2. Selection of cutting dosage
(1) Conventional Lathe to determine the weight of the back knife (mm)
Turning back the size of the main basis of machine tool, fixture, cutting tool and workpiece process system stiffness to decide, in the case of system stiffness allow, in order to ensure the number with the least amount of feed to remove rough machining allowance, according to the allowance of processed spares determine stratified cutting depth, select a larger quantity of turning, in order to improve production efficiency. In numerical control machining, to ensure the necessary machining accuracy and surface roughness of the parts, Conventional Lathe a small amount of allowance (0.2-0.5mm) is recommended, and a knife is used in the final finishing process. In rough machining, in addition to leaving the necessary semi-finishing and finishing allowance, the rough machining should be completed at the minimum number of times in the condition of the rigidity of the process system. The remaining amount shall be greater than the deformation of the parts and the surface integrity of the parts. (2) determine spindle speed n (r/min)
The spindle speed n is determined according to the cutting speed VC (m/min) which is allowed by the cutter.
Among them: VC - cutting speed. D - diameter of parts or knives (mm). The speed of cutting speed VC is closely related to tool durability. With the increase of VC, Conventional Lathe the durability of the tool will decrease rapidly, so the choice of VC depends on the tool's durability. After the spindle speed n is determined, the nc program must be written in accordance with the format specified in the nc machine tool control system. In actual operation, the operator can according to actual processing condition, through an appropriate adjustment of nc machine tools spindle speed ratio on the control panel switch, to control the size of the spindle speed, in order to determine the best spindle speed. (3) the input velocity F (mm/r, mm/min) of the feed or feed speed F is the relative displacement of the part and the milling cutter in the direction of the unit time at the time of cutting. The unit is mm/r or mm/min. Feed or feed speed used on nc machine tool feed function word F, F is an important parameter of nc machine tool cutting dosage, Conventional Lathe the main basis for parts machining accuracy and surface roughness requirements, as well as to determine the use of cutting tool and workpiece material. The higher the machining accuracy of the part, the lower the surface roughness requirement, the smaller the value of the selection. In practice, the machine tool, cutting tool, fixture and be taken into account by precision machining parts, materials, structure stiffness, the change of mechanical properties, curvature of the process system of rigid and chip breaker, choosing the appropriate feed speed.