The design principle of induction heating quenching inductor

The design principle of induction heating quenching sensors - 2020 01 - 03 Li Zhiming ( Great river cinda co. , LTD. ) Induction heating quenching inductor is accomplished using the eddy current principle parts surface hardening, strengthen the key on the surface of the heating element. Heating parts on the surface of a lot of more phyletic, the shape difference is very big, so the design of the sensor forms, usually the main consideration of the size of sensor of induction coil diameter, height, cross section shape, cooling water and blowhole, its design idea is as follows. 1. Sensor the diameter of the sensor is based on the shape of the surface of the heated parts contour to determine, for there must be a certain gap between the induction coil and the parts, and uniform everywhere. When heated, external circular sensors inside diameter D = D0 + 2 a; When heated, internal hole outside diameter D = D0 - sensors 2a。 Which do for cylindrical workpiece diameter or inner hole diameter, a is the gap between them. Take 1 of shaft parts. 5 to 3. Take 1 5 mm, gear parts. Five to four. 5 mm, inner hole parts take 1 ~ 2 mm. Such as in intermediate frequency quenching, the clearance is slightly different, generally shaft parts of 2. 5 ~ 3 mm, inner hole is 2 ~ 3 mm. 2. The height of the sensor height sensor mainly according to the heating power P0, workpiece diameter D and the identified than power P set to determine: ( 1) A heating for short shaft parts, wedge Angle to prevent overheating, the height of the induction coil should be less than the height of the parts. （ 2) Long axial parts a heating cooling, the height of the induction coil for quenching area length of 1. 05 ~ 1. 2 times. （ 3) Induction coil, single turn height is too high, the uneven heating of the workpiece surface, middle temperature higher than the temperature on both sides of the lot, the higher the frequency, the more obvious, induction coil, so the use of turns in two or three turns more instead. 3. Of induction coil, induction coil, cross section shape of cross section shape is more, such as round, square, rectangle, plate type ( Outside the cooling water pipe welding) Etc. , when quenching area are at the same time, the bending made the induction coil, rectangular section material, and uniform heating layer, circular cross section of the worst, but easy to bending. Choose the material for brass tube or copper tube, high frequency induction coil wall thickness of 0. Medium frequency induction coil will be 1, 5 mm. 5mm。 4. Cooling water and blowhole is given for eddy current loss and fever, so need each component is cooled, the copper pipe can be directly cooled, copper part can be made of sandwich or welding of copper cooling water; Continuous or high frequency heating at the same time using the spray cooling, induction coil diameter of blowhole is 0. 8 to 1. 0 mm, medium frequency heating for 1 ~ 2 mm; The perspective of continuous heating quenching induction coil blowhole of 35 & deg; ~ 45度; , the pitch is 3 ~ 5 mm. Quenching water spray hole should be staggered at the same time, uniform pitch arrangement, general blowhole area should be less than the area of the inlet pipe, to ensure that the pressure of the water inflow pressure meet the requirements. Need to be aware of is to solve the problem of ring of inner hole heating effect, can card feng oxygen on induction coil ( High frequency quenching) Or silicon steel ( Intermediate frequency quenching) Piece, made the door glyph magnetizer, drive current along the magnetizer gap ( The outer layer of the induction coil) Flow through. To prevent should not hardening part is heated, can use the steel ring or block of soft magnetic materials magnetic short circuit ring. Induction coil, induction heating, the other for near the pointed part clearance should be appropriate increase, in case of local overheating. The paper published in the metal processing ( Hot working) Magazine,