Extrusion forming device and forming method for marine low-speed diesel engine crank forging

Abstract

The invention provides an extrusion forming device for a marine low-speed diesel engine crank forging. The extrusion forming device comprises an extrusion inner sleeve, an outer sleeve body, an upperpunch and a moving platen; the center positions of the extrusion inner sleeve, the outer sleeve body and the moving platen correspond, the outer sleeve body is located on the outer side of the extrusion inner sleeve, and the extrusion inner sleeve comprises an inner sleeve body and an inner sleeve bottom plate located at the bottom of the extrusion inner sleeve; and the outer sleeve body and the inner sleeve bottom plate are fixed to the moving platen, and the upper punch is arranged in a blank in the inner sleeve in an up-down moving mode. A forming method of the extrusion forming device comprises the steps of blank making, extrusion die assembly, extrusion die lubrication, extrusion die preheating, blank heating, phosphorus removal, extrusion forming and die removing. According to the extrusion forming device and the forming method, the size margin of the crank forging can be greatly decreased, thus the weight of the forging blank is decreased, the machining allowance is decreased, the material utilization rate is increased, and the manufacturing cost is lowered.

Description

technical field [0001] The invention relates to an extrusion molding device, in particular to an extrusion molding device and a molding method for a marine low-speed diesel engine crank forging. Background technique [0002] As an important part of the semi-assembled large marine crankshaft, the crank throw is difficult to forge, and its volume is large and its forming is complicated. It is also required that the forging has good fiber flow. [0003] The forging method of existing large-scale bell crank has the following several kinds: [0004] The first one is the block forging method; the forming process of the block forging method is as follows: figure 1 As shown, a crank forming method that forges the crank blank into an angular square, and then cuts off excess metal by machining. The advantages of this method are: simple shape, easy forming, no need for die forging, and less forging times; The disadvantage of this method is: the forgings produced by this method not on...

AI Technical Summary

Problems solved by technology

[0004] The first one is the block forging method; the forming process of the block forging method is as follows: figure 1 As shown, a crank forming method that forges the crank blank into an angular block, and then cuts off excess metal by machining. The advantages of this method are: simple shape, easy forming, no need for die forging, and less forging times; The disadvantage of this method is: the forgings produced by this method not only have a large machining allowance and high cost, but also the quality is difficult to meet the standard, and the scrap rate is high

The disadvantages of this method are: difficult forming, complicated process, poor material utilization and formability, and defects such as pores may appear in forgings

Its advantages make the internal structure dense, without destroying the fiber streamline of the crank metal, the qualified rate is high, the forging process time is short, and the material utilization rate is also high; the disadvantages of this method are: high tooling costs, large forming force, and equipment tonnage Large, difficult to operate, and difficult to demould later

The disadvantages of this method are: low pass rate, high energy consumption and high cost

The disadvantage of this forging method is that it needs a set of special forging die and its auxiliary equipment, the manufacturing cost is high, and it is not suitable for small batch production

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