It is necessary to understand the working conditions and technical requirements of crankshaft quenching

The crankshaft is one of the most important parts of the internal combustion engine. It forms the power plant of the engine together with the cylinder, piston, connecting rod and other parts. The crankshaft is composed of the main journal, connecting rod journal, crank arm, balance weight, crankshaft front end and flywheel adapter.

The function of the crankshaft is to convert the force transmitted through the connecting rod during the power stroke into torque, and drive other parts of the engine (such as water pumps, oil pumps, valves, etc.) to move and output power (power). That is, each part of the crankshaft produces complex alternating stresses such as bending, torsion, shearing, and stretching, which will cause torsional vibration and bending vibration of the crankshaft. At the same time, under certain conditions, it will also produce large additional stress, so the force is very large. complex. The main shaft diameter, connecting rod shaft diameter and crankshaft arm of the crankshaft are severely worn everywhere, and the forces are different.

So what are the mechanical properties of the crankshaft? How can I make the crankshaft work better?

The crankshaft should first have the following mechanical properties:

1. It has good fatigue strength and impact resistance.

2. It has sufficient strength to reduce the warping deformation of the shaft diameter and improve its self-resistance to earthquakes.

3. Has good lubrication effect.

4. The surface has high hardness, bending fatigue strength, torsional strength and wear resistance.

According to the working characteristics and technical requirements of the crankshaft, the principles for selecting crankshaft materials are: firstly, to meet the mechanical performance requirements of the crankshaft; secondly, considering that the crankshaft must have good fatigue strength and wear resistance, and the surface must have high hardness; finally, for machining performance. At the same time, the influence of factors such as the service life of the crankshaft and the heat treatment of the material, surface strengthening process, processing accuracy and surface condition of the parts should be comprehensively considered.

The crankshaft is often die-forged from medium-carbon steel and medium-carbon alloy steel. It can also be made of ductile iron. Generally, different steel types are selected according to the load and type of the engine. Ductile iron is divided into magnesium ductile iron, rare earth ductile iron and alloy ductile iron. In recent years, crankshafts cast from rare earth ductile iron have been widely used, which can not only meet the strength and stiffness requirements of the crankshaft, but also save a large amount of quality raw materials and reduce the cost. manufacturing cost. The composition, casting and heat treatment of ductile iron have a significant impact on its performance. Therefore, during processing, the technical parameters of each process should be strictly controlled. In order to improve the wear resistance and fatigue strength of the crankshaft, the crankshaft journal surface needs to be high-frequency quenched or nitrided and ground to obtain low surface roughness and high surface precision. In real life, 45 steel and ductile iron are often used to manufacture crankshafts.

Based on the above statement, it seems that the choice of material is crucial for the crankshaft. Zhengzhou Gou's has many years of experience in the field of induction heating and has a deep understanding of products and related knowledge. If you have any questions in this regard, you can call us for consultation.