Development trend of crankshaft machining manufacturing technology:
1. Foundry technology
(1) Smelting
For the melting of high-grade cast iron, a large-capacity intermediate frequency furnace will be used for smelting or variable-frequency intermediate frequency furnace smelting, and a direct reading spectrometer will be used to detect the molten iron composition. Ductile iron treatment adopts subcontracting to develop a new variety of spheroidizing agent, and adopts advanced gestation methods such as inoculation, in-type gestation and compound gestation. The parameters of the melting process enable microcomputer control and screen display.
(2) Modeling
Lost foam casting will be developed and promoted. In sand casting, boxless injection molding and extrusion molding will be valued and will continue to be promoted in new or rebuilt plants. The original high-pressure molding line will continue to be used, and some of the key components will be improved to achieve automatic core and lower core.

2, forging technology
The automatic line with hot forging press and electro-hydraulic hammer as the main engine is the development direction of forged crankshaft production. These production lines will generally adopt precision shearing, roll forging (cross wedge rolling), medium frequency induction heating, finishing hydraulic press. Advanced technology such as precision pressing, and equipped with a robot, conveyor belt, and a die changer with a rotary table to form a flexible manufacturing system (FMS). FMS automatically replaces workpieces and molds and automatically adjusts parameters for continuous measurement during operation. Display and record data such as forging thickness and maximum pressure and compare with the set value to select the best deformation to obtain a quality product. The entire system is monitored by the central control room for unmanned operation.

3. Mechanical processing technology
Crankshaft roughing will use CNC lathes, CNC internal milling machines, CNC broaching machines and other advanced equipment to perform CNC turning, internal milling and car-broaching on the main journal and connecting rod journals to effectively reduce the deformation of crankshaft machining. Crankshaft finishing will extensively use a CNC-controlled crankshaft grinder to finish the journal. The grinding machine will be equipped with the automatic dynamic balancing device of the grinding wheel, automatic tracking device of the center frame, automatic measurement, automatic compensation device, automatic dressing of the grinding wheel, constant line speed and other functional requirements to ensure the stability of the grinding quality. High-precision equipment relies on the status quo of imports and is not expected to change in the short term.

4. Heat treatment technology and surface strengthening technology
(1) Crankshaft medium frequency induction hardening
The medium frequency induction hardening of the crankshaft will adopt the microcomputer monitoring closed-loop medium frequency induction heating device, which has the characteristics of high efficiency, stable quality and controllable operation.
(2) Crankshaft soft nitriding
For high-volume production of crankshafts, in order to improve product quality, a microcomputer-controlled nitrogen-based atmosphere gas soft nitriding line will be used in the future. The nitrogen-based atmosphere gas soft nitriding production line consists of a front washing machine (cleaning and drying), a preheating furnace, a soft nitriding furnace, a cooling oil tank, a post-cleaning machine (cleaning and drying), a control system, and a gas-making gas distribution system.
(3) Crankshaft surface strengthening technology
Ductile iron crankshaft fillet rolling strengthening will be widely used in crankshaft machining. In addition, the composite strengthening process such as round roll rolling strengthening and journal surface quenching will also be applied to crankshaft machining. Forging steel crankshaft reinforcement will be more The ground is treated with a journal and rounded corners.