CN105014315A - Forging method of camshaft blank - Google Patents

Abstract

The invention discloses a forging method of a camshaft blank, which comprises the following steps that S1, a cylindrical blank is cast; S2, round steel with the diameter of 35mm is adopted for forging, and is sawn into a plurality of equal-length pipe fittings by a sawing machine; S3, according to a camshaft blank drawing, a cross wedge rolling die and a die forging forming die are designed; S4, round bars are blanked according to technological requirements; and S5, with the utilization of rolling waste heat or reheating, the camshaft blank part is sent into the die forging forming die, and subjected to forming forging on a press machine, cam parts pre-rolled into revolved bodies in different shapes and diameters are forged be in cam peach shapes according to the requirements of the drawing, and flash around various cams is cut off, and precision forming of the camshaft blank is completed. The forging method facilitates mass industrial production of the camshaft blank; the phenomena of dirt carrying and insufficient charging in a forging process are reduced; the mechanical property of the camshaft blank is further improved; materials used by the camshaft blank are saved; and the die life of the camshaft blank is increased.

Description

A kind of forging method of cam shaft blank

Technical field

The present invention relates to axle class processing technique field, specifically belong to a kind of forging method of cam shaft blank.

Background technology

Camshaft is one of part of key in Valve System of Internal Combustion Engine, and whole valve actuating mechanism is by camshaft actuated, and the performance of design to whole air distribution system of cam plays conclusive effect.Camshaft poor rigidity, yielding; Precision is high, and difficulty of processing is large; Along with the development of automobile industry, add the demand of accessory, the demand of camshaft can be in any more always.Before last century the nineties, the manufacturing process of steel Engine Cam axis blank directly uses round bar turning or forging.The early 1990s, first China developed cross wedge rolling forming cam shaft blank technology, and the side of the end neck of camshaft, axle journal and cam realizes Accurate Shaping, can not reprocess or process on a small quantity.This technology is than former technique saving steel more than 30%, and production efficiency improves 4-10 doubly, achieves distinct economic, manufactures field extensive use at China's steel cam shaft blank.But substantially can only to be shaped revolving parts due to cross wedge rolling, Cam body portion is rolled into cylinder by maximum cylindrical, and the peach-shaped of cam body need be shaped by turnery processing.Still more follow-up machined and the more metal material of loss will be expended.

Summary of the invention

For the problems referred to above, the object of this invention is to provide a kind of forging method of cam shaft blank, it is made to be beneficial to large batch of industrialized production, and decrease in forging process the phenomenon occurring that folder is dirty, be not fully filled, the mechanical property of product is improved further, save product materials, improve the die life of product.

The technical solution used in the present invention is as follows:

A kind of forging method of cam shaft blank, comprise the following steps: in S1, cast cylinder blank step cylinder blank, chemical component weight percentage is: C 0.3%-1.2%, Mn1.8-2.1%, Si 0.7-0.8%, Cr 1.2-1.5%, W 0.6%-0.9%, V 0.4-1.2%, Cu 0.4 ~ 0.5%, Mo 0.5%-1.2%, P≤0.05%, S≤0.03%, surplus is Fe and is inevitably mingled with matter; Tapping temperature controls at 1200 DEG C-1300 DEG C, preparation yttrium-base heavy rare earth, and 300 DEG C of preheatings are filled with method in employing bag and carry out nodularization Metamorphism treatment, be sprinkled into appropriate slag former and cover after punching bag, and the 5min that calms, casting of skimming; The base substrate temperature of moulding by casting is down to 300 DEG C, then is heated to 800-1000 DEG C, insulation 1-3 hour, and stove is chilled to 300 DEG C, is incubated 3 hours, then is heated to 800-1000 DEG C, then naturally cools;

S2, forging step select diameter to be 35mm round steel, utilize sawing machine blank to be sawn into the equal multistage pipe fitting of length;

S3, by round bar according to technological requirement blanking, be heated to rolling temperature, the cross wedge rolling die that round bar after heating is sent in cross wedge rolling machine is rolled, make at the bottom of axle and axle journal position reaches the final drawing requirement of cam shaft blank, cam position needs according to die forging the revolving body being rolled into difformity and diameter;

S4, utilize rolling waste heat or heat, cam shaft blank is sent in die-forging forming mould, forcing press forms forging, the cam position rolling into difformity and diameter revolving body is in advance forged cam peach-shaped according to drawing requirement; Excise overlap around each cam, complete cam shaft blank Accurate Shaping.

By the workpiece Shot Blasting after heat treatment in described S4; By the piece packaging of Shot Blasting.

Compared with the prior art, beneficial effect of the present invention is as follows:

The present invention makes it be beneficial to large batch of industrialized production, and decreases in forging process the phenomenon occurring that folder is dirty, be not fully filled, and the mechanical property of product is improved further, has saved product materials, improves the die life of product; Simultaneously owing to adopting precise wedge lateral base, at the bottom of the axle of cam shaft blank and axle journal namely reach drawing requirement in the cross wedge rolling stage, cam position can roll into suitable shape in advance according to shape and position, can give full play to that cross wedge rolling forming accuracy is high, efficiency is high, material-saving rate advantages of higher.

Detailed description of the invention

A kind of forging method of cam shaft blank, comprise the following steps: in S1, cast cylinder blank step cylinder blank, chemical component weight percentage is: C 0.3%-1.2%, Mn1.8-2.1%, Si 0.7-0.8%, Cr 1.2-1.5%, W 0.6%-0.9%, V 0.4-1.2%, Cu 0.4 ~ 0.5%, Mo 0.5%-1.2%, P≤0.05%, S≤0.03%, surplus is Fe and is inevitably mingled with matter; Tapping temperature controls at 1200 DEG C-1300 DEG C, preparation yttrium-base heavy rare earth, and 300 DEG C of preheatings are filled with method in employing bag and carry out nodularization Metamorphism treatment, be sprinkled into appropriate slag former and cover after punching bag, and the 5min that calms, casting of skimming; The base substrate temperature of moulding by casting is down to 300 DEG C, then is heated to 800-1000 DEG C, insulation 1-3 hour, and stove is chilled to 300 DEG C, is incubated 3 hours, then is heated to 800-1000 DEG C, then naturally cools;

S2, forging step select diameter to be 35mm round steel, utilize sawing machine blank to be sawn into the equal multistage pipe fitting of length;

S3, according to cam shaft blank layout design cross wedge rolling die and die-forging forming mould;

S4, by round bar according to technological requirement blanking, be heated to rolling temperature, the cross wedge rolling die that round bar after heating is sent in cross wedge rolling machine is rolled, make at the bottom of axle and axle journal position reaches the final drawing requirement of cam shaft blank, cam position needs according to die forging the revolving body being rolled into difformity and diameter;

S5, utilize rolling waste heat or heat again, the workpiece Shot Blasting after heat treatment; By the piece packaging of Shot Blasting, cam shaft blank is sent in die-forging forming mould, forcing press forms forging, the cam position rolling into difformity and diameter revolving body is in advance forged cam peach-shaped according to drawing requirement; Excise overlap around each cam, complete cam shaft blank Accurate Shaping.

Present invention process is beneficial to large batch of industrialized production, and decreases in forging process the phenomenon occurring that folder is dirty, be not fully filled, and the mechanical property of product is improved further, has saved product materials, improves the die life of product.

More than show and describe general principle of the present invention, principal character and advantage of the present invention.The technical staff of the industry should understand; the present invention is not restricted to the described embodiments; what describe in above-described embodiment and description just illustrates principle of the present invention; without departing from the spirit and scope of the present invention; the present invention also has various changes and modifications, and these changes and improvements all fall in the claimed scope of the invention.Application claims protection domain is defined by appending claims and equivalent thereof.

Claims (2)

1. a forging method for cam shaft blank, is characterized in that, comprises the following steps:

In S1, cast cylinder blank step cylinder blank, chemical component weight percentage is: C0.3%-1.2%, Mn 1.8-2.1%, Si 0.7-0.8%, Cr 1.2-1.5%, W 0.6%-0.9%, V 0.4-1.2%, Cu 0.4 ~ 0.5%, Mo 0.5%-1.2%, P≤0.05%, S≤0.03%, surplus is Fe and is inevitably mingled with matter; Tapping temperature controls at 1200 DEG C-1300 DEG C, preparation yttrium-base heavy rare earth, and 300 DEG C of preheatings are filled with method in employing bag and carry out nodularization Metamorphism treatment, be sprinkled into appropriate slag former and cover after punching bag, and the 5min that calms, casting of skimming; The base substrate temperature of moulding by casting is down to 300 DEG C, then is heated to 800-1000 DEG C, insulation 1-3 hour, and stove is chilled to 300 DEG C, is incubated 3 hours, then is heated to 800-1000 DEG C, then naturally cools;

S2, forging step select diameter to be 35mm round steel, utilize sawing machine blank to be sawn into the equal multistage pipe fitting of length;

S3, by round bar according to technological requirement blanking, be heated to rolling temperature, the cross wedge rolling die that round bar after heating is sent in cross wedge rolling machine is rolled, make at the bottom of axle and axle journal position reaches the final drawing requirement of cam shaft blank, cam position needs according to die forging the revolving body being rolled into difformity and diameter;

S4, utilize rolling waste heat or heat, cam shaft blank is sent in die-forging forming mould, forcing press forms forging, the cam position rolling into difformity and diameter revolving body is in advance forged cam peach-shaped according to drawing requirement; Excise overlap around each cam, complete cam shaft blank Accurate Shaping.

2. the forging method of a kind of cam shaft blank according to claim 1, is characterized in that: by the workpiece Shot Blasting after heat treatment in described S4; By the piece packaging of Shot Blasting.