Free forging forming method for large six throw crankshaft

Abstract

The invention discloses a free forging forming method for a large six throw crankshaft. The large six throw crankshaft is forged overall through an angle presetting method, angle accuracy of three bent plates arranged mutually at the included angles of 120 degrees can be guaranteed, and the novel free forging method is provided. Through the method of flattening-squaring and heavy reduction drawingout after upsetting of steel ingots and control over the longitudinal blank width ratio, the transverse tool width ratio and the reduction rate in the forging process, it is guaranteed that the internal quality of the large six throw crankshaft forged piece meets the ultrasonic flaw detection requirement. Metal fiber of the forged crankshaft is continuous and free of torsion, and the quality of the forged piece is good. Tool accessory investment for the method is small, operation is simple, the cost is low, the quality of the large six throw crankshaft is improved, and the method can be usedfor free forging production of equal-angle multi-throw crankshafts.

Description

technical field [0001] The invention relates to a free forging forming method of a large six-turn crankshaft, which belongs to the technical field of forging. Background technique [0002] The crankshaft is the key component of the piston reciprocating compressor. It receives the power from the motor in the form of torque and converts it into the reciprocating linear motion of the piston to compress the gas to do work. It bears complex and alternating dynamic loads during high-speed operation, and its reliability directly affects the reliability and service life of the whole machine. The crankshaft is the most critical stress-bearing part in the power end of the reciprocating pump. With the continuous improvement and strengthening of the power density of the reciprocating pump, the working conditions of the crankshaft are becoming more and more harsh. Therefore, higher requirements are put forward for the comprehensive mechanical properties of the crankshaft, such as streng...

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Problems solved by technology

[0004] 1. The shape of the forging is complex, consisting of three curved plates forming an angle of 120° to each other. It is difficult to control the free forging to ensure accurate angles during forming.

[0005] 2. Improper control of the forming process is likely to cause disconnection, resulting in the scrapping of forgings

[0006] 3. The requirements for flaw detection are relatively strict (ultrasonic flaw detection implements GB / T6402-2008 standard level 4, requiring that the equivalent diameter of a single point-shaped discontinuous defect is below Ф3mm, and the equivalent diameter of long or dense point-shaped discontinuous defects is below Ф2mm), Manufacturing is more difficult

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