When process designing, process designing personnel must determine the cutting dosage of every working procedure. When choosing cutting dosage, must all sorts of elements of mature influence cutting, choose cutting condition correctly, determine cutting dosage reasonably, can raise machining quality and yield effectively. The factor that affects cutting condition has: Machine tool, tool, cutting tool reachs the tigidity of workpiece; Feed of deepness of cutting speed, cutting, cutting is led; Workpiece precision reachs exterior surface roughness; Cutting tool life expectancy reachs the biggest productivity; The sort of cutting fluid, cooling means; The hardness of workpiece material reachs heat treatment state; Work measure; The life of the machine tool.
Afore-mentioned in all elements give priority to with rate of feed of deepness of cutting speed, cutting, cutting want an element.
Cutting speed speed affects cutting efficiency directly. If cutting rate is too minor, criterion cutting time is met lengthen, cutting tool cannot develop its function; If cutting rate is too rapid, although can shorten cutting time, but cutting tool produces high fever easily, affect the life of cutting tool. The element that decides cutting rate is very much, wraparound rise have:
(Material of 1) cutting tool. Cutting tool material is different, permission highest cutting rate is different also. High-speed steel cutting tool is high temperature resistant cutting speed is less than 50m ／ Min, carbide cutting tool is high temperature resistant cutting speed can amount to above of 100m ／ Min, of cutting tool of pottery and porcelain high temperature resistant cutting speed can be as high as 1000m ／ Min.
(2) workpiece material. Discretion of workpiece material hardness can affect rate of cutting tool cutting, speed of the cutting when same cutting tool processes hard data should be reduced, and when processing weaker data, cutting rate can rise.
(Life of 3) cutting tool. Cutting tool uses time (life) the demand is long, should use inferior cutting rate. Conversely, can use higher cutting rate.
(4) cutting deepness and feed are measured. Cutting deepness and feed amount are large, cutting fights force big also, heat in metal cutting can increase, reason cutting speed should be reduced.
(The appearance of 5) cutting tool. The sharp degree of the size of the appearance of cutting tool, angle, point meets those who affect cutting rate to choose.
(6) cooling fluid is used. Gao Ke of good, precision raises machine tool tigidity cutting speed; Conversely, need to lower cutting rate.
In all elements of afore-mentioned influence cutting speed, the effect with cutting tool qualitative material is most main.
Cutting deepness basically suffers machine tool stiffness restrict, below the condition that allows in machine tool stiffness, cutting deepness should as far as possible big, if do not accept the restriction that machines precision, can make cutting deepness is equal to the mental allowance of the spare parts. Can reduce knife number so.
The cutting rate that main shaft rotate speed should permit according to machine tool and cutting tool will decide. Can use numeration or check watch law to choose.
R) of feed F(mm ／ or Min) of ／ of feed speed F(mm want surface roughness of the treatment precision according to the spare parts, surface, cutting tool and workpiece material to choose. Speed of the biggest feed accepts the restriction of machine tool stiffness and feed drive and numerical control system.
Process designing member when choosing cutting dosage, must mix according to the requirement of machine tool manual cutting tool durability, the choice suits machine tool characteristic and cutting tool the cutting dosage of optimal durability. OK also of course by experience, use analogy law to determine cutting dosage. No matter use what method to choose cutting dosage, want to make sure the durability of cutting tool can complete the treatment of a spare parts, or make sure cutting tool durability does not work under order, the smallest also cannot the time under half order.