CN102861859A - Cold forging process for end face teeth of starting gear - Google Patents

Abstract

The invention relates to a cold forging process for end face teeth of a starting gear. The process comprises the following steps of: blanking, annealing, manufacturing a blank, performing surface lubrication, pre-forging the teeth, performing precision forging on the teeth and the like. The cold forging process has the advantages that metal extruded at room temperature is fine in crystalline grains, and the level of grain size is over 6 levels; and the production efficiency is improved greatly, and the quality of products is stable and reliable.

Description

Starter toothed wheel end-tooth cold-forging technique

Technical field

The present invention relates to a kind of starter toothed wheel end-tooth cold-forging technique.

Background technology

The kind of starter toothed wheel in the market is a lot, be widely used on motorcycle, but the end-tooth part all is to adopt traditional Gear Milling basically.Traditional process route is forge hot base → turning, end face → milling end-surface teeth, traditional processing method efficient low, energy consumption is excessive, equipment investment is excessive and the defective such as unstable product quality.Per tour only can be produced about 150 of blanks, the investment of equipment, cutter is excessive (to need 1 altogether milling cutter meter 1W RMB, 4 80W RMB of milling machine), in addition waste of raw materials serious (about single blank waste 0.15Kg), and because the defective of forge hot blank itself (as be mingled with, metallic fiber is not smooth etc.) can't be remedied by follow-up processing, bring hidden danger to product quality.Starter toothed wheel is a kind of starter mechanism, and end-tooth is had very high requirement of strength, simultaneously the metallographic of product is required high (grain size number is 6 grades), and traditional manufacture method is difficult to realize.

Summary of the invention

Goal of the invention: the purpose of this invention is to provide a kind of production efficiency height, steady quality and the high starter toothed wheel end-tooth cold-forging technique of intensity.

Technical scheme: a kind of starter toothed wheel end-tooth cold-forging technique, described cold-forging technique may further comprise the steps:

A) blanking: adopt the computerized numerical control sawing machine blanking, perpendicularity is less than or equal to 0.3;

B) annealing: adopt pit type annealing furnace to vacuumize and inflated with nitrogen protection annealing, the monolateral degree of depth of annealing rear oxidation decarburization is less than or equal to 0.1 millimeter, and material hardness is HB113-120 after the annealing;

C) base: adopt the instrument lathe base, height error is controlled in 0.3;

D) surface lubrication: the blank among the step c is carried out oil removing, pickling, washing, phosphatization processing, air-cooled and saponification processing;

E) blocking tooth: adopt the hydraulic press of 2000KN to push, extruding force is 200T, in minute error 0.05 such as tooth;

F) finish forge tooth: adopt the hydraulic press of 2000KN to push, extruding force is 200T, in the end-tooth height error 0.05, and tooth-face roughness 1.6, hardness HB150-180 after the extruding, extrusion speed 〉=8/min.

The described annealing heating rate of step b is less than 150 ℃/h, and cooling rate is less than 50 ℃/h; Forvacuum exhausts at every turn and is filled with nitrogen, and its pressure is more than or equal to 0.01MPa; The annealing metallographic structure is the F+P ball, and rank is the 4-6 level.

The described surface lubrication of steps d may further comprise the steps:

A) electrochemical deoiling: blank is dropped into the sodium silicate solution of NaOH, 60～80g/L sodium carbonate, 25～80g/L sodium phosphate and the 10～15g/L of 60～100g/L, treatment temperature 〉=85 ℃, 15～25 minutes processing times;

B) mobile clear water is washed;

C) pickling: blank is dropped into pickling in the sodium chloride solution of the sulfuric acid of 120-180g/L and 8-10g/L, pickling temperature is 65-75 ℃, and pickling time is 5-10 minute;

D) clear water that flows is washed: be in order to prevent that the pickle that is adsorbed on blank surface from bringing in the lower road Phosphating Solution, to affect the phosphatization effect;

E) hot water wash: be preheating before the phosphatization;

F) phosphatization is processed: will drop into through the blank of overpickling and washing in the phosphoric acid solution of 9g/L zinc oxide and 23mg/L phosphatization and process, and the total acidity 16-20 point of solution, free acidity is the 2.5-4.5 point, temperature is 85-90 ℃, processing time 30-40min;

G) air-cooled;

H) saponification: rise air-cooledly with after the saponification liquor melting blank being immersed in the saponification liquor post-tensioning, and then immerse pull-up, so repeatedly air-cooled again after 3-4 time.

Beneficial effect: the present invention is by pushing metal under room temperature state, and metal grain is tiny after the extruding, and grain size number reaches more than 6 grades, and production efficiency is greatly improved stable and reliable product quality simultaneously.

The specific embodiment

The invention will be further described below in conjunction with embodiment.

Invent described process route: blanking → annealing → surface lubrication → blocking tooth → finish forge tooth

The production efficiency of this mode of production is greatly improved, per tour can be produced about 5000 of blanks, equipment, frock investment lower (only needing 18WRMB of press, mould two cover 2WRMB and auxiliary facility that some are auxiliary to amount to 20WRMB), single blank can save material about 0.1Kg in addition, and the distortion of metal is violent in the cold-stamped process, so generation flow harden, and metallic fiber is complete, greatly improved the intensity index of technology, remedy the defective that hot bundle bar may exist itself, guaranteed output and quality.

Blanking: adopt the blanking of numerical control tape sawing machine, perpendicularity≤0.3.

Annealing: adopt pit type annealing furnace to vacuumize and inflated with nitrogen protection annealing, the decarburization of annealing rear oxidation is monolateral≤and 0.1 millimeter, material hardness HB113-120 after the annealing.

Require: 1, firing rate＜150 ℃/h, cooling rate＜50 ℃/h;

2, forvacuum exhausts at every turn and is filled with nitrogen, its pressure 〉=0.01Mpa;

3, the annealing metallographic structure is the F+P ball, and rank is the 4-6 level

Base: adopt the instrument lathe base, height error is controlled in 0.3.

Surface lubrication:

A) electrochemical deoiling: blank is dropped into the sodium silicate solution of NaOH, 60～80g/L sodium carbonate, 25～80g/L sodium phosphate and the 10～15g/L of 60～100g/L, treatment temperature 〉=85 ℃, 15～25 minutes processing times;

B) mobile clear water is washed;

C) pickling: blank is dropped into pickling in the sodium chloride solution of the sulfuric acid of 120-180g/L and 8-10g/L, pickling temperature is 65-75 ℃, and pickling time is 5-10 minute;

D) clear water that flows is washed: be in order to prevent that the pickle that is adsorbed on blank surface from bringing in the lower road Phosphating Solution, to affect the phosphatization effect;

E) hot water wash: be preheating before the phosphatization;

F) phosphatization is processed: will drop into through the blank of overpickling and washing in the phosphoric acid solution of 9g/L zinc oxide and 23mg/L phosphatization and process, and the total acidity 16-20 point of solution, free acidity is the 2.5-4.5 point, temperature is 85-90 ℃, processing time 30-40min;

G) air-cooled;

H) saponification: rise air-cooledly with after the saponification liquor melting blank being immersed in the saponification liquor post-tensioning, and then immerse pull-up, so repeatedly air-cooled again after 3-4 time.

The blocking tooth: adopt the hydraulic press of 2000KN to push, extruding force P=200T is in minute error 0.05 such as tooth.

The finish forge tooth: adopt the hydraulic press of 2000KN to push, extruding force P=200T, in the end-tooth height error 0.05, tooth-face roughness 1.6, hardness HB150-180 after the extruding, extrusion speed 〉=8/min.Change has occured in the metal grain after the extruding after testing, makes originally to be bordering on spherical crystal grain owing to distortion is elongated, and is ordered arrangement.Resistance of deformation has been improved to being order state in the crystal grain position, also makes Mechanical Property Anisotropy simultaneously.

Facts have proved the technical characteristics of the starter toothed wheel end-tooth after extruding:

1, grain size is better than 6 grades

2, mechanical property: σ b 〉=1300MPa σ s 〉=900MPa

3, fit quality: 9 grades

4, mechanical endurance: 〉=100 ten thousand times

In sum: through startup axoplasm amount, the dependable performance that cold forging is produced, production efficiency first mate improves, and cost obviously descends, and can satisfy client's demand.

Claims (3)

1. starter toothed wheel end-tooth cold-forging technique, it is characterized in that: described cold-forging technique may further comprise the steps:

A) blanking: adopt the computerized numerical control sawing machine blanking, perpendicularity is less than or equal to 0.3;

B) annealing: adopt pit type annealing furnace to vacuumize and inflated with nitrogen protection annealing, the monolateral degree of depth of annealing rear oxidation decarburization is less than or equal to 0.1 millimeter, and material hardness is HB113-120 after the annealing;

C) base: adopt the instrument lathe base, height error is controlled in 0.3;

D) surface lubrication: the blank among the step c is carried out oil removing, pickling, washing, phosphatization processing, air-cooled and saponification processing;

E) blocking tooth: adopt the hydraulic press of 2000KN to push, extruding force is 200T, in minute error 0.05 such as tooth;

F) finish forge tooth: adopt the hydraulic press of 2000KN to push, extruding force is 200T, in the end-tooth height error 0.05, and tooth-face roughness 1.6, hardness HB150-180 after the extruding, extrusion speed 〉=8/min.

2. starter toothed wheel end-tooth cold-forging technique according to claim 1, it is characterized in that: the described annealing heating rate of step b is less than 150 ℃/h, and cooling rate is less than 50 ℃/h; Forvacuum exhausts at every turn and is filled with nitrogen, and its pressure is more than or equal to 0.01MPa; The annealing metallographic structure is the F+P ball, and rank is the 4-6 level.

3. starter toothed wheel end-tooth cold-forging technique according to claim 1, it is characterized in that: the described surface lubrication of steps d may further comprise the steps:

A) electrochemical deoiling: blank is dropped into the sodium silicate solution of NaOH, 60～80g/L sodium carbonate, 25～80g/L sodium phosphate and the 10～15g/L of 60～100g/L, treatment temperature 〉=85 ℃, 15～25 minutes processing times;

B) mobile clear water is washed;

C) pickling: blank is dropped into pickling in the sodium chloride solution of the sulfuric acid of 120-180g/L and 8-10g/L, pickling temperature is 65-75 ℃, and pickling time is 5-10 minute;

D) clear water that flows is washed: be in order to prevent that the pickle that is adsorbed on blank surface from bringing in the lower road Phosphating Solution, to affect the phosphatization effect;

E) hot water wash: be preheating before the phosphatization;

F) phosphatization is processed: will drop into through the blank of overpickling and washing in the phosphoric acid solution of 9g/L zinc oxide and 23mg/L phosphatization and process, and the total acidity 16-20 point of solution, free acidity is the 2.5-4.5 point, temperature is 85-90 ℃, processing time 30-40min;

G) air-cooled;

H) saponification: rise air-cooledly with after the saponification liquor melting blank being immersed in the saponification liquor post-tensioning, and then immerse pull-up, so repeatedly air-cooled again after 3-4 time.