CN103084541A

CN103084541A - Forming technology of air cylinder cover casting

Info

Publication number: CN103084541A
Application number: CN2013100363689A
Authority: CN
Inventors: 蒋勤南; 王新节; 赵秋会; 彭和宜
Original assignee: GUIZHOU YINGJIER MACHINE MANUFACTURE CO Ltd
Current assignee: GUIZHOU YINGJIER MACHINE MANUFACTURE CO Ltd
Priority date: 2013-01-31
Filing date: 2013-01-31
Publication date: 2013-05-08

Abstract

The invention discloses a forming technology of an air cylinder cover casting. The forming technology of the air cylinder cover casting comprises the following steps of: firstly modeling the appearance profile and a sand core of the cylinder cover casting by adopting precoated sand; then assembling an outer model and the sand core and putting into a sand box; and then filling in dry sand or dry stones for pouring. According to the invention, the technology of combining precoated sand modeling and dry sand (stone) mold casting is adopted, the outer model moulding sand is molded and is assembled with the moulding sand, and is put into the sand box, the mold thickness adopts dry sand/stones to replace resin sand completely, and pouring is carried out after the dry sand/stones is/are compacted. Because the dry sand (stone) has no bonding agent and has good permeability, gases generated during pouring can be exhausted rapidly and smoothly; mold filling is stable; and because the metal liquids at the upper part are lower than metal liquids at the lower part, sequential condensation and dead head feeding are carried out smoothly; the mold-filling capacity is high; defects of cavity shrinkage, shrinkage porosity, incapability of pouring and the like can be prevented easily; and moreover, one-mold multi-element processing is easy to realize, and the production efficiency and casting technology yield are improved.

Description

A kind of forming technology of cylinder cap casting

Technical field

The present invention relates to cast manufacture field, especially a kind of forming technology of cylinder cap casting

Background technology

At present, the manufacture level of engine cylinder-body cylinder cap is one of important symbol of weighing a national manufacturing industry level, so also to a great extent representing the development level of a national auto industry.Improving constantly engine power, reducing fuel consumption and reduce exhaust emissions is the domestic demand of auto industry self-growth, is also the objective requirement of external environment condition.Cylinder cap has significant impact to many technical parameters of engine, thereby dimension precision requirement is high, and the surfaces externally and internally quality requirement is tight; Casting structure is complicated, wall thickness differs greatly, during shaping, core is many and complicated, water cavity requires flowing water unobstructed, and during work, temperature sharply changes repeatedly, because the expansion and the contraction that constantly produce produce alternating thermal stress, easily cause fatigue failure, therefore require cylinder head casting rational in infrastructure, material has high intensity, hardness and good anti-fatigue performance, casting character and air-tightness, and casting technique and technical difficulty are large.

The major defect that occurs in seepage, coarse grains, shrinkage porosite cylinder cap Foundry Production.Seepage particularly, if solved this problem, the yield rate of foundry goods can reach more than 95%.Although many technological measures of implementing for this problem are also arranged, and majority all produces little effect.

Summary of the invention

The objective of the invention is: the forming technology that a kind of cylinder cap casting is provided, it can obviously put forward the quality of foundry goods, improve the metallographic structure density, reduce the generation of shrinkage porosite, shrinkage cavity, reduce field trash, the cylinder cap quality is greatly improved, improve casting yield, environmental contamination reduction, reduce production costs simultaneously.

The present invention is achieved in that the forming technology of cylinder cap casting, first the appearance profile of cylinder head casting and core is adopted the precoated sand moulding, then will put into sandbox after external form and assembly of sand core, then inserts dry sand or stone is poured into a mould.

Described dry sand or stone granularity are 3～10mm.Dry sand or stone binder free, the sandstone granularity is unsuitable excessive, and excessive filling is not fine and close, and good permeability is poured into a mould after jolt ramming, and the gas that produces during cast can be rapidly, discharge smoothly, fills type steady.

Described dry sand or stone are quartz sand, and its dioxide-containing silica and hardness should be identical with the use precoated sand.So that the regeneration of precoated sand is used.Should not adopt lime stone, because lime stone hardness is low, easily produce fine sand and ash content, worsen the core sand performance, regeneration can increase resin demand when using, and the core fragility of making is large, easily produces the defectives such as sand holes.

Technical scheme of the present invention has the following advantages:

(1) reduced the production cost: adopt precoated sand fully except core sand in precoated sand shell mould (core), dry sand (stone) casting mold combination process, after the external form molding sand is made type and assembly of sand core, put into sandbox, the mold thickness part adopts dry sand/stone to replace resin sand fully, pours into a mould after jolt ramming.After unpacking, resin sand separates with dry sand/stone, resin sand moulding again after sand is processed, dry sand/stone screening minute rear directly recovery, need not can continue moulding through processing, thereby use amount and the sand disposal cost of resin have been reduced, reduce production cost, according to measuring and calculating, approximately can reduce the resin use amount more than 40%.

(2) be to realize the another effective way of environmental protection casting: adopt dry sand/stone to replace the part phenolic sand molding in precoated sand shell mould (core), dry sand (stone) casting mold combination process, thereby reduce the use amount of resin, reduced the environmental pollution because using resin to cause in producing, met national energy-saving and reduce discharging policy requirements.

(3) inherent quality of product is improved: precoated sand shell mould (core), dry sand (stone) casting mold combination process are owing to having used dry sand/stone, strengthened the gas permeability of casting mold, make the gas that produces in casting process can be in time, discharge outside casting mold rapidly, thereby reduce the possibility that gas hole defect produces.Owing to adopting this technique, mobility and the mold-filling capacity of molten metal in casting mold is all relatively good, so can reduce pouring temperature, can effectively prevent the generation of the defectives such as shrinkage cavity and porosity, thereby effectively prevent the cylinder cap seepage.

Owing to having adopted technique scheme, compared with prior art, the present invention adopts precoated sand moulding and the compound technique of dry sand (stone) casting mold, after the external form molding sand is made type and assembly of sand core, put into sandbox, the mold thickness part adopts dry sand/stone to replace resin sand fully, pours into a mould after jolt ramming.Due to dry sand (stone) binder free, good permeability, the gas that produces during cast can be rapidly, discharge smoothly, fill type steady, and due to upper metal liquid higher than the bottom, therefore be conducive to consecutive solidification and riser feeding, mold-filling capacity is strong, easily avoid shrinkage cavity and porosity, water less than etc. defective, and many than being easier to the type that realizes, enhance productivity and casting process yield.The present invention had both possessed the advantage of precoated sand moulding (core), had strengthened again the gas permeability of casting mold, was beneficial to and filled the type feeding, avoided the shrinkage porosite shrinkage cavity, thereby improved casting quality, had improved yield rate.Reduced simultaneously the application of the casting auxiliary material such as resin, environmental contamination reduction reduces production costs.。The present invention is simple, and is with low cost, and result of use is good.The present invention also is applicable to the processing of the intricate casting of Shell-Class below 100 kilograms except being applicable to the cylinder cap casting of various high-air-tightness.

The specific embodiment

embodiments of the invention: the forming technology of cylinder cap casting, produce 4JB1 casting pig material four cylinder diesel engine cylinder heads, the inside die cavity of the cylinder cap casting in the present embodiment and outside the die cavity female parts on the modeling number of unmolulding directions outside mainly contain the cooling jacket core, the air intake duct core, the exhaust duct core, fuel injector core and profile female parts combination core form, first appearance profile and the core with cylinder head casting adopts the precoated sand moulding, then external form and core are assembled, the casting mold that assembles is put into sandbox, then inserting granularity and be the dry sand of 5mm pours into a mould, dry sand is quartz sand, and its dioxide-containing silica and hardness should be identical with the use precoated sand, so that the regeneration of precoated sand is used.

Claims

1. the forming technology of a cylinder cap casting is characterized in that: first appearance profile and the core with cylinder head casting adopts the precoated sand moulding, then will put into sandbox after external form and assembly of sand core, then inserts dry sand or drystone is poured into a mould.

2. the production technology of high-air-tightness automobile cylinder cover foundry goods according to claim 1, it is characterized in that: described dry sand or stone granularity are 3～10mm.

3. the production technology of high-air-tightness automobile cylinder cover foundry goods according to claim 1 and 2, it is characterized in that: described dry sand or stone are quartz sand, its dioxide-containing silica and hardness are identical with the use precoated sand.