CN106077470A

CN106077470A - Compacted ferrum engine cylinder cover pouring technology

Info

Publication number: CN106077470A
Application number: CN201610732037.2A
Authority: CN
Inventors: 黄党怀
Original assignee: Chongqing New Red Flag Cylinder Cap Manufacturing Co Ltd
Current assignee: Chongqing New Red Flag Cylinder Cap Manufacturing Co Ltd
Priority date: 2016-08-26
Filing date: 2016-08-26
Publication date: 2016-11-09

Abstract

The present invention relates to metal casting technique field, it is specifically related to a kind of compacted ferrum engine cylinder cover pouring technology, including following operation, matched moulds preheats, adds sand hardening, coating, group case, standby potting syrup, cast, pickup, the program is compared to the prior art, iron flask sand-covering technique is applied in the casting of vermicular cast iron engine cylinder cover, it is cast with the sand mold shell of rigidity owing to iron flask covers sand, make sand mold bulk strength high, indeformable, decrease the deformation during casting pouring, and positioning reliable, precision height, foundry goods is also more prone to the demoulding simultaneously.

Description

Compacted ferrum engine cylinder cover pouring technology

Technical field

The present invention relates to metal casting technique field, be specifically related to a kind of compacted ferrum engine cylinder cover pouring technology.

Background technology

Vermicular cast iron, is called for short compacted ferrum, refers to that liquid cast-iron is through creepage rate so that it is in graphite be vermiform and a small amount of pelletizing Shape.If creepage rate is excessive, vermicular cast iron reforms into spheroidal graphite cast-iron, and compactedization deficiency reforms into casting pig.Due to vermiform The form of graphite between lamellar and spherical between, so the mechanical property of vermicular cast iron is between casting pig and spheroidal graphite cast-iron, Its casting character, damping and heat conductivity are better than spheroidal graphite cast-iron, close with casting pig.Owing to vermicular cast iron has spheroidal graphite cast-iron concurrently With the performance of casting pig, therefore, it has the purposes of uniqueness, at ingot mould, automobile engine, exhaustor, glass mold, diesel oil The application of the aspects such as machine cylinder cap, braking component is respectively provided with good effect.

Cylinder cap is arranged on above cylinder body, from cylinder body top seal cylinder and constitute combustor.Owing to cylinder cap is frequent and high temperature High-pressure gas contacts, and the most often bears the biggest thermic load and mechanical load, so the intensity of foundry goods, compactness and size Precision is the important technology index of measured engine cylinder cap.Conventional compacted ferrum engine cylinder cover is that casting forms, technological process master Including prepare casting mold, preparation core mold, mould preheating, lower core, prepare molten metal bath, molding cast, cool down open Mould, cut rising head, surface process, heat treatment, quality inspection warehouse-in.Owing to existing mould mostly is sand mold mould, rigidity is more weak, in cast Time foundry goods be susceptible to deformation, the blank dimensional accuracy causing cylinder cap is low, and compactness is inadequate, and then affects the intensity of cylinder cap.

Summary of the invention

The invention is intended to provide a kind of compacted ferrum engine cylinder cover pouring technology, to improve dimensional accuracy and the intensity of cylinder cap.

Compacted ferrum engine cylinder cover pouring technology in this programme, including following operation:

S1, matched moulds preheat: assemble iron flask and mould and leave gap in centre and formed and cover sand cavity；

S2, add sand hardening: to described in step S1 cover sand cavity in inject precoated sand, heating, drying makes precoated sand harden Film, is formed and covers layer of sand；

S3, coating: the separately mould after precoated sand hardening and iron flask, by described iron flask and die flip to covering layer of sand court On, coat water-based graphite coating on described layer of sand surface of covering, and heat iron flask and mould carries out preheating and makes water-based graphite be coated with The moisture evaporation of material；

S4, group case: the iron flask after coating in step S3 and mould being re-assemblied, middle part forms the die cavity for cast；

S5, standby potting syrup: in high-temperature smelting pot, prepare former ferrum fused solution, and carry out creepage rate；

S6, cast: pour into a mould in the former ferrum fused solution after creepage rate in step S5 is joined the die cavity described in step S4, Natural cooling after casting complete；

S7, pickup: open iron flask and mould, take out foundry goods, removes the precoated sand in iron flask and mould, repeats step S1.

Beneficial effect: compared to the prior art iron flask sand-covering technique, is applied to vermicular cast iron engine cylinder by the program In lid casting, it is cast with the sand mold shell of rigidity owing to iron flask covers sand so that sand mold bulk strength is high, indeformable, decreases Deformation during casting pouring, and position reliable, precision height, foundry goods is also more prone to the demoulding simultaneously；Casting before right Former ferrum fused solution carries out creepage rate, it is possible to be effectively improved the heat conductivity of foundry goods, the thermal stress produced under the conditions of alternating temperature-changing Less, and intensity is higher；It is difficult to stress by the foundry goods of creepage rate concentrate, thus its thermal fatigue resistance is than magnesium iron and ash casting Ferrum is the best；Graphite paint is added, it is possible to reduce the surface roughness of foundry goods, avoid the impurity in precoated sand simultaneously covering to be coated with on layer of sand Enter foundry goods, affect the total quality of foundry goods.

Further, using the mode of upright casting in described step S6 during cast, i.e. during cast, iron flask and mould stand up；Use The mode of upright casting, former ferrum fused solution has certain downforce under the effect of self gravitation, makes the foundry goods quality of cast more Densification, casting quality is higher.

Further, the sand layer thickness that covers in described step S2 is 3～8mm, is adapted to various sizes of cylinder cap.

Further, the heating-up temperature of the former ferrous solution in described step S5 is 1420～1520 DEG C, and vermicular cast iron is heated molten The temperature melted should strictly control, when temperature is less than 1420 DEG C, and the poor fluidity of compacted ferrum, impact cast；Temperature is higher than 1520 DEG C Time, then can destroy the crystal structure of compacted ferrum.

Further, the preheating temperature in described step S3 is 180～250 DEG C, when temperature is less than 180 DEG C, does not reaches mould The operating temperature of tool, can affect the surface quality of foundry goods；When temperature is higher than 250 DEG C, the shrinkage factor of foundry goods hardening reduces, and band is cast During part cooling molding, hole situation easily occurs.

Further, the drying temperature in described step S2 is 150～200 DEG C.When temperature is less than 150 DEG C, drying effect is not Enough；When temperature is higher than 200 DEG C, it is easily caused and covers layer of sand specific surface overdrying, and it is internally dry insufficient to cover layer of sand.

Detailed description of the invention

Below by detailed description of the invention, the present invention is further detailed explanation, this compacted ferrum engine cylinder cover pourer Concretely comprising the following steps of skill:

Step one, matched moulds preheats, and mould has a profile adapted with iron flask in-profile, assemble iron flask and mould and Centre is left gap formation and is covered sand cavity, and the THICKNESS CONTROL covering sand cavity is more suitable 3～8mm, uses natural gas stove to add Hot iron sandbox and mould preheat, and control temperature and are advisable at 180～250 DEG C；

Step 2, adds sand hardening: to described in step one cover sand cavity in inject precoated sand, core-shooting process uses special covering Sand machine is carried out, and heating, drying makes precoated sand hardening skinning, is formed and covers layer of sand, and heating and temperature control is suitable at 150～200 DEG C.

Step 3, coating: the separately mould after precoated sand hardening and iron flask, by described iron flask and die flip to covering Layer of sand upward, uses brushing to graphite coating covering layer of sand surface, and blows away the dust covering layer of sand surface with high pressure air rifle；

Step 4, organizes case: the iron flask after coating in step 3 and mould are re-assemblied, and middle part forms the type for cast Chamber；

Step 5, standby potting syrup: prepare former ferrum fused solution in high-temperature smelting pot, and carry out creepage rate, add the most before casting Enter vermiculizer, as front the more commonly used vermiculizer has magnesium alloy, titanium alloy, rare earth etc., to make vermicular cast iron, heating-up temperature control System is at 1420～1520 DEG C；

Step 6, cast: carry out in the former ferrum fused solution after creepage rate in step 5 is joined the die cavity described in step 4 Cast, stands up iron flask and mould during cast, even if the side of cylinder cap die cavity is in vertical direction, the coldest after casting complete But；

Step 7, pickup: open iron flask and mould, take out foundry goods, remove the precoated sand in iron flask and mould, repeat step One is circulated operation.

Claims

1. a compacted ferrum engine cylinder cover pouring technology, it is characterised in that include following operation:

Compacted ferrum engine cylinder cover pouring technology the most according to claim 1, it is characterised in that: in described step S6 during cast Using the mode of upright casting, i.e. during cast, iron flask and mould stand up.

Compacted ferrum engine cylinder cover pouring technology the most according to claim 1, it is characterised in that: described step S2 covers sand Layer thickness is 3～8mm.

4. according to the compacted ferrum engine cylinder cover pouring technology described in Claims 2 or 3, it is characterised in that: in described step S5 The heating-up temperature of former ferrous solution is 1420～1520 DEG C.

Compacted ferrum engine cylinder cover pouring technology the most according to claim 4, it is characterised in that: the preheating in described step S3 Temperature is 180～250 DEG C.

Compacted ferrum engine cylinder cover pouring technology the most according to claim 5, it is characterised in that: the drying in described step S2 Temperature is 150～200 DEG C.