Local die forging forming method of connecting rod of marine low-speed diesel engine

Abstract

The invention relates to a local die forging forming method of a connecting rod of a marine low-speed diesel engine. The manner of free forging is adopted, and a steel ingot is forged into a low-speeddiesel engine connecting rod blank; the two ends of the blank are sawn to be flat, a rod portion is machined, and a low-speed diesel engine connecting rod die forging blank is obtained through pretreatment; a heating furnace is used for locally heating the thick end or the thin end of the low-speed diesel engine connecting rod die forging blank; a mold used for carrying out local die forging on special-shaped connecting rods at the two ends is used for carrying out die forging on the heated end, the inward-concaved face of the end is formed, meanwhile, the transition face and the appearance are formed, and a semi-finished connecting rod of the low-speed diesel engine is obtained; and the other end is heated, the mold is replaced, the inward-concaved face, the transition face and the appearance of the other end are formed, and the connecting rod of the low-speed diesel engine is obtained. By means of the local die forging forming method, connecting rod die forging can be achieved on afree forging press, blank making is simple, unbalance loading is avoided in die forging, and forming force is small; the appearance size is close to that of the appearance of a connecting rod part, and large forgings in complex shapes can be forged in a profiling manner; and continuity of branched metal at the two ends of the connecting rod can be kept, process dressings are greatly reduced, and cost is low.

Description

technical field [0001] The invention belongs to the technical field of die forging forming for large forgings, and in particular relates to a local die forging forming method for a connecting rod of a marine low-speed diesel engine. Background technique [0002] The connecting rod of a marine diesel engine is an important part of a marine engine. The two ends are respectively connected with the piston rod and the crankshaft (crank) to convert the reciprocating motion of the piston into the rotational motion of the crankshaft and transmit the force acting on the piston to the crankshaft. , to realize the transfer of motion and energy. The connecting rod of a marine diesel engine is subject to cyclic tension and compression from the piston during work, as well as the lateral and longitudinal inertial forces generated during the conversion of motion, and the stress state it bears is complex. Therefore, it is required that the connecting rod of marine diesel engine not only has...

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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