Partial Die Forging Forming Method of Marine Low-speed Diesel Engine Connecting Rod

Abstract

The invention relates to a local die forging method for a connecting rod of a marine low-speed diesel engine, which adopts free forging to forge a steel ingot into a blank of a connecting rod of a low-speed diesel engine; Low-speed diesel engine connecting rod die forging billet; use a heating furnace to locally heat the thick end or thin end of the low-speed diesel engine connecting rod die forging billet; use a mold for locally forging special-shaped connecting rods at both ends to forge the heated end to form the inner part of the end Concave surface, forming the transition surface and shape at the same time to obtain a semi-finished low-speed diesel engine connecting rod; heat the other end, replace the mold, and form the inner concave surface, transition surface and shape of the other end to obtain a low-speed diesel engine connecting rod. The invention can realize the connecting rod die forging on the free forging press, the billet making is simple, the die forging has no eccentric load, and the forming force is small; the shape size is close to the shape of the connecting rod parts, and large forgings with complex shapes can be forged by copying; The metal continuity of the bifurcation at both ends of the rod greatly reduces the process dressing, and the cost is low.

Description

Technical field[0001]The present invention belongs to the field of large forging die forging forming, and specifically, a local die forging method for marine low speed diesel connectors.Background technique[0002]The marine diesel connecting rod is an important part of the ship engine, and both ends are connected to the piston rod, the crankshaft (crank), and the reciprocating motion of the piston is converted into a crank, and the force acting on the piston is transmitted to the crankshaft. To achieve movement and energy transfer. The marine diesel connecting rod is affected by the cycle pull of the piston, as well as the transverse, longitudinal inertia force generated during transformation movement, and the stress state is complex. Therefore, it is required that the marine diesel connecting rod must have both strength and fatigue properties, but also have sufficient rigidity and toughness.[0003]Marine diesel connecting rod (seeFigure 6 ), The shape is complex, the weight and size ...

AI Technical Summary

Problems solved by technology

[0004] 1. In the free forging method, the outer spherical surface of the thick end and the conical surface of the thin end of the connecting rod forging cannot be accurately forged by free forging, and can only be forged into square steps. After subsequent machining to remove material, the external dimensions are obtained. The blank requires a lot of technology Auxiliary materials, this process auxiliary material is a necessary process auxiliary material in the free forging forging method, which cannot be overcome, so it causes a huge waste of raw materials and a large amount of waste of machining time; the inner concave surface at both ends of the marine diesel engine connecting rod cannot be forged by free forging , free forging can only be forged into a solid body, and subsequent machining removes material to obtain an inner concave surface;

[0005] 2. The shape of the connecting rod of marine diesel engine is complicated, and the precision of free forging itself is low, so it is usually necessary to reserve 40-50mm machining allowance, resulting in waste of machining hours

[0006] 3. For the marine diesel connecting rod blank produced by free forging, the shape and inner concave surface at both ends of the material are removed by machining, the metal fiber is cut off, the continuity of the forging structure is destroyed, and the internal quality advantage of forged marine diesel connecting rod is weakened. The quality and life of marine diesel engine connecting rods are unfavorable

The marine diesel engine connecting rod adopts full die forging, which is not feasible in terms of equipment and technology

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