The invention relates to a method for producing powder smelt screw ratchet, which comprises: mixing the materials, compressing molding, sintering, compressing and shaping, to obtain the ratchet. The invention also discloses a relative mould, which is formed by a compressing upper punch, compressing middle mould, compressing lower punch; the upper part of lower punch has the inner screw tooth matched with the outer screw tooth; the upper punch is sliding matched with the middle mould; the middle mould is sliding matched with the lower mould; the compressing core rod has compressing core rod, friction plate, and rotation element; the upper part of compressing core rod has outer screw tooth; the lower end of core rod and the upper end of rotating element have friction plate between them, while their contact surface has lubricant. The invention, via the rotation of core rod, realizes the one-time molding and demoulding of inner screw ratchet, to improve the yield and reduce the cost.

Manufacture method and die for powder metallurgy inside spin ratchet wheel

The invention discloses a squeeze casting die and a squeeze casting method for straight toothed spur gears. The squeeze casting die comprises an upper die, a middle die, a lower die, a bottom die, web plate hole cores and a shaft hole core. The upper die, the middle die, the lower die, the bottom die and the shaft hole core are coaxially arranged, the middle die is fixed to the upper end of the lower die, a sliding inner cavity is arranged on the lower die, and the bottom die is nested in the sliding inner cavity and is slidably sealed in the sliding inner cavity; the web plate hole cores and the shaft hole core are fixedly arranged on the bottom die, and positioning exhaust holes which correspond to the web plate hole cores and the shaft hole core are formed in the upper die; a sealed pouring cavity is formed among the upper die, the middle die, the lower die and the bottom die in an enclosed manner when the upper die and the middle die are closed; the web plate hole cores and the shaft hole core are inserted into the corresponding positioning exhaust holes formed in the upper die. The squeeze casting die and the squeeze casting method have the advantages of high material utilization rate of 95%, high production efficiency, zero pollution due to waste sand, energy conservation, environmental protection, small gear blank machining allowance, fine crystal grains, good mechanical property and capability of carrying out continuous operation.

Squeeze casting die and casting method for straight toothed spur gears

The invention discloses a method for producing a bevel gear with ratchets on an end face through powder metallurgy warm forming. The method comprises the following steps of: preparing iron powder, copper powder, nickel powder, molybdenum powder, graphite powder and a warm forming special lubricant into a mixer to mix according to a proportion; filling in a heated mould; preparing a compact under the condition of unit pressing pressure of 6.5-7.5 T/cm and density of reaching 7.2-7.3 g/cm ; placing the compact in a sintering furnace and sintering in a protective atmosphere of mixed gas of hydrogen and nitrogen at 1,120 DEG C for 40 minutes; nitrocarburizing the sintered compact in a carbon and nitrogen atmosphere of 850 DEG C in a controllable atmosphere thermal treatment furnace for 60 minutes; quenching at 850 DEG C; oil-cooling at a cooling speed of 110 DEG C/10 minutes; tempering at 180 DEG C for 1 hour to machine an inner hole on a precision numerical control lathe to dimensional requirements through tooth shape positioning; finishing; removing thermal treatment oil stain and surface burrs; cleaning; drying; and soaking anti-rust oil to prepare a finished product. The method has the advantages of high product consistency, capability of meeting requirements of large-scale stable production, particular suitability for producing the bevel gear of high accuracy, high strength and high difficulty.

Method for producing bevel gear with ratchet on end face through powder metallurgy warm forming

The invention discloses Mn-contained mixture steel powder for powder metallurgy and a preparing method. The Mn-contained mixture steel powder is composed of water atomization pure iron powder, Mn-contained water atomization pre-alloyed steel powder, FeMn alloy powder, graphite powder and a lubricant, wherein the mass percentage content of Mn is lower than or equal to 3%. The preparing method includes the steps of preparing the components and mechanically and evenly mixing the components. The pressing performance and the sintered density of the prepared mixture steel powder are superior to the pressing performance and the sintered density of the Mn-contained water atomization pre-alloyed steel powder with the same components, and compared with a finished product obtained by sintering conventional Mn-contained mechanical mixture powder with the same contents, a sintered finished product is lower in oxygen content and high in density. The content of the Mn can be as high as 3%. The Mn-contained mixture steel powder is reasonable in component matching and high in Mn content, the prepared Mn-contained mixture steel powder combines the advantages of even Mn-element distribution in the Mn-contained pre-alloyed steel powder and the good pressing performance of the conventional Mn-contained mechanical mixture powder, the pressing performance is good, the sintered finished product is low in oxygen content and high in density, and the Mn-contained mixture steel powder is suitable for industrial production.

Mn-contained mixture steel powder for powder metallurgy and preparing method

A manufacturing method of a motorcycle engine oil pump gear is characterized in that metal powder serves as raw material, is filled into a motorcycle engine oil pump gear die, is shaped by pressing and is sintered. The metal powder is pressed, sintered to alloy the metal powder into alloy steel, mechanical cutting and machining are omitted, steel material is prevented from wasting, steel resource is saved greatly, the produced motorcycle engine oil pump gear has the mechanical property of steel, the mechanical property and product entire quality are further improved, and production efficiency is improved greatly. The method is simple in process and high in product accuracy and consistence; and the quality stability of products produced in large scale is guaranteed.

Manufacturing method of motorcycle engine oil pump gear

The invention discloses a powder metallurgical internal inclined gear, according to weight percent, containing elements Cu 1-3%, Ni 1-3%, Mo 0.1-1%, and the rest Fe and unavoidable component, where its spiral angle is not greater than 35 degrees, its pressure angle is 5-25 degrees, and its mode is 0.5-2.5 degrees. It mixes the alloy powder of Cu, Ni and Mo to make press molding, firing and shaping so as to make it. Its making mould is top, bottom and middle moulds and core stick. It gears stably and accurately, has small friction coefficient and low mechanical noise. It adopts special designed mould, presses by mould core's rotary ascending or descending along screw, which converts the rotary pressing into axial pressing, can press internal inclined gears of various spiral angles.

Chen Xiufa

Papers

Powder metallurgy internal hilical gear, and its manufacturing method and die using same method