Process analysis of quenching heat treatment of camshaft using medium frequency induction heating power supply

The camshaft is a component in a piston engine that controls the opening and closing of the valves. During the operation of the piston engine, the camshaft has to bear huge friction, so it wears out relatively quickly. For this reason, many manufacturers use medium-frequency induction heating power to quench and heat treat the camshaft, hoping to improve its hardness, wear resistance and service life. Today, we will take a look at the induction hardening process of the camshaft.

1) When the cam and journal width are similar, they can share one sensor. Jiefang automobile camshaft has four different parts: cam, journal, eccentric, and gear. They share a sensor and the effect is good. The difficulty of this process lies in the quenching and heating of the cam that is very close to the journal. When 8-10kHz current is used, part of the electromagnetic field of the inductor will dissipate to the adjacent journal. In this way, the journal will partially temper, and the cam will be The heating temperature of this part on the journal side is low. Now the two ends of the cam sensor have been designed to be equipped with magnetic conductors, which solves this difficulty.

2) The second difficulty encountered in the camshaft process is that the distance between two adjacent cams is too close, such as 6-8mm apart. At this time, it is also difficult to attach a magnetic conductor to the inductor. The solution is to heat two adjacent cams together. However, due to the strong magnetic field in the middle of the inductor, the inductor must be designed so that the two effective circles in parallel are farther apart in the middle part and are not completely consistent with the width of the cam. Corresponding. In recent years, the camshaft quenching process has been improved in two aspects: ① using a profiling sensor to solve the problem of shallow quenching layer in the arc part of the cam; ② using multiple power supplies to supply multiple adjacent cams to solve the problem of adjacent cams. The cams interact with each other causing backfire problems. These new processes have been applied in production.

3) For car alloy cast iron camshafts, multiple inductors are generally used in series to heat the entire camshaft at one time.

Many manufacturers use the above process to quench and heat treat camshafts. The hardness and wear resistance of the produced camshafts are greatly improved, meeting the needs of the work.