CNC lathe describes how to choose these three elements: the spindle speed S, the amount of feed F, the depth of the feed, in the CNC lathe cutting principle course called cutting
First, the cutting speed (linear velocity, perimeter speed) V (m / min)
To select the number of revolutions per minute of the spindle, you must first know how much the cutting line speed V should be.
V choice: depends on the tool material, the workpiece material, processing conditions and so on.
Carbide, V can be achieved higher, generally desirable 100 m / min or more, the general purchase of the blade are provided when the technical parameters: what materials can be selected when the number of large linear speed.
High speed steel: V can only be achieved lower, generally not more than 70 m / min, in most cases take 20 to 30 m / min or less.
High hardness, V low; cast iron, V take low, the tool material for the carbide when the take 70 ~ 80 m / min; low carbon steel, V up to 100 m / min, non-ferrous metals, V desirable higher (100 ~ 200 m / min.) Quenched steel, stainless steel, V should be taken lower.
Rough processing, V take some lower; finishing, V take higher.
Machine tools, workpieces, tool rigidity of the system is poor, V low.
If the NC program uses S is the number of revolutions per minute, then the S should be calculated according to the workpiece diameter and the cutting line speed V:
S (spindle revolution per minute) = V (cutting line speed) * 1000 / (3.1416 * workpiece diameter)
If the NC program uses a constant line speed, then S can be directly used cutting line speed V (m / min)
Second, the amount of feed (the amount of knife) F
Mainly depends on the workpiece surface roughness requirements. Finishing, the surface requirements of high, take the knife to take small: 0.06 ~ 0.12mm / spindle per turn.
Roughing, it is desirable. Mainly determined by the strength of the tool, generally desirable 0.3 or more, the tool main angle is large when the tool strength is poor, the amount of feed can not be too large.
Also consider the power of the machine, the rigidity of the workpiece and the tool.
The NC program uses two units of feed: mm / min, mm / spindle per revolution, the above units are mm / spindle per turn, such as the use of mm / min, available formula conversion: per minute feed = Turn in the amount of the spindle
Third, the depth of the knife (cutting depth)
When finishing, it is generally desirable to take 0.5 (radius value) or less.
Roughing, according to the workpiece, tool, machine situation decision, the general small lathe (the maximum processing diameter of 400mm below) Turning under the normal state of 45 steel, radial direction of the depth of the knife is generally not more than 5mm.
Also note that if the CNC lathe spindle speed is used in ordinary frequency control, then when the spindle speed is very low per minute (less than 100 to 200 r / min), the motor output power will be significantly reduced, then eat knife Depth and infeed can only be achieved very small.
The daily maintenance of CNC lathes
1, every day to do a good job of the rail surface clean and lubricated, automatic lubrication system of the machine to regularly check, clean the automatic lubrication system, check the oil, add lubricants in time to check whether the pump starts to start the oil and stop;
2, daily check the spindle box automatic lubrication system is working properly, regular replacement of the spindle box lubricants;
3, pay attention to check the electrical cabinet cooling fan is working properly, the air duct filter with or without clogging, cleaning dust;
4, pay attention to check the cooling system, check the liquid level, the timely addition of oil or water, oil, water dirty to be replaced when cleaning;
5, pay attention to check the spindle drive belt, adjust the degree of tightness;
6, pay attention to check the degree of tightening rails, adjust the gap;
7, pay attention to check the machine hydraulic system tank oil pump with or without abnormal noise, the working oil surface height is appropriate, the pressure gauge is normal, the pipeline and the joints with or without leakage;
8, pay attention to check the guide, machine cover is full and effective;
9, pay attention to check the mechanical parts of the mechanical precision, reduce the shape and position deviation;
10, every day to do a good job cleaning machine cleaning, cleaning iron, rubbing the rail parts of the coolant, to prevent rusty rails.