CN104325075A - V method casting process - Google Patents

Abstract

The present invention discloses a V method casting process, which comprises: 1) covering a plastic film baked to achieve a plastic state on a template, and pumping gas through a vacuum pump to make the film tightly attach to the template so as to mold; 2) coating; 3) placing a sand box with a filtration gas pumping pipe on the plate covered with the plastic film; 4) filling the sand box with dry quartz sand, slightly vibrating to make the quartz sand compact, scraping to achieve the flat state, placing the sealed film, opening the valve, and pumping the air in the mold sand; 5) releasing the vacuum in the template, and drawing the mold to prepare the upper mold; 6) sequentially performing the steps 1)-5) to prepare the lower mold; 7) removing the core, closing the box, and casting; 8) after the metal is solidified, stopping the gas pumping of the cast mold, wherein the cast mold self-collapses when the pressure in the mold is close to the atmospheric pressure so as to obtain the cast. With the V method casting process of the present invention, the product quality and the production efficiency can be substantially improved, the production cost can be reduced, and the production process requirements of energy saving and emission saving can be achieved.

Description

A kind of V method casting technique

Technical field

The present invention relates to casting technique field, be specifically related to a kind of V method casting technique.

Background technology

Along with the fast development of science and technology, the demand of each branch of industry to foundry goods constantly increases, simultaneously, also more and more higher to the requirement of casting quality, cast blank is the source product of machine-building, at present, mostly adopt sand casting mode cast blank in prior art, adopt sand casting mode mainly to there is following shortcoming:

1, sand holes pore is many, and rough surface, mould hardness are low and uneven, are not easy withdrawing pattern;

2, equipment is complicated, cost of investment is high and operating maintenance expense is high;

3, using rate of metal is low, and product yield is low, and allowance is larger;

4, contaminated environment.

Summary of the invention

In order to solve the problems of the technologies described above, the invention provides a kind of V method casting technique, this casting technique does not use adhesive, can increase substantially quality and the production efficiency of product, reduces production cost simultaneously and realizes the manufacturing technique requirent of energy-saving and emission-reduction.

Object of the present invention carrys out specific implementation by the following technical programs:

A kind of V method casting technique, comprises the following steps:

1) by baking in the covered rearing with plastic film of mecystasis in template, vavuum pump is bled, and that film is closely attached in template is shaping;

2) coat;

3) sandbox with filtering suction pipe is placed on has covered in the template of plastic sheeting;

4) in sandbox, fill drystone sand and do not contain binding agent in drystone sand, microseism makes drystone sand consolidation, strikes off, puts sealing film, opens valve and pumps air in molding sand, makes to there is pressure differential inside and outside casting mold;

5) separate the vacuum in removing template, then carry out withdrawing pattern, obtained mo(u)ld top half;

6) according to above-mentioned steps 1) to 5) mo(u)ld bottom half processed;

7) core, mould assembling, cast under;

8) after metal freezing, stop bleeding to casting mold, in type during pressures near atmospheric, casting mold is just defeated and dispersed voluntarily and obtain foundry goods.

Further, in step 4), casting mold external and internal pressure difference is 300-400mmHg.

A kind of V method of the present invention casting technique, committed step: overlay film, moulding---coat---place sandbox---back-up sand consolidation---withdrawing pattern---mo(u)ld bottom half processed---lower core, mould assembling, cast---obtains foundry goods, has following beneficial effect:

1, raising casting quality, sand holes pore is few, any surface finish, clear-cut, size accurate, and mould hardness is high and evenly, withdrawing pattern is easy;

2, simplified apparatus, investment reduction, minimizing run each maintenance cost.Save relevant adhesive, additives and sand blender, reclamation of return sand rate is more than 95%, and equipment investment reduces 30%, and equipment dynamic is 60% of wet type, and labour reduces 35%;

3, mould and sandbox long service life;

4, using rate of metal is high, and in the moulding of V method, metal fluidity is good, and stowage capacity is strong, can cast out the thin-wall part of 3mm.Mould hardness is high, cooling is slow, utilizes feeding, reduces the size of rising head; Product yield improves, and decreases allowance.

5, be conducive to environmental protection, owing to adopting the dry sand of binder free, eliminate the binding agent of other casting process Sands, additives or baking operation, decrease environmental pollution, is Green foundry technique.

Therefore, the enforcement of this casting technique has great economic benefit and development prospect.

Accompanying drawing explanation

According to drawings and embodiments the present invention is described in further detail below.

Fig. 1 is the flow chart of a kind of V method of the present invention casting technique;

Fig. 2 is the schematic diagram of the heating of step 1) plastic sheeting and overlay film;

Fig. 3 is step 3), 4) place the schematic diagram of sandbox and back-up sand consolidation;

Fig. 4 is the schematic diagram of core under step 7), mould assembling.

In figure: 1-grilled mold device; 2-plastic sheeting baking position; 3-plastic sheeting; 4-vital qi pump interface; 5-aspirating hole; 6-sandbox; 7-filtering suction pipe; 8-sealing film; 9-core; 10-airway; 11-vital qi pump interface; 12-vital qi pump interface.

Detailed description of the invention

As shown in Figure 1, a kind of V method casting technique described in the embodiment of the present invention, comprises the following steps:

1) be that the covered rearing with plastic film of mecystasis is in template by baking, vavuum pump is bled, and that film is closely attached in template is shaping, as shown in Figure 2, grilled mold device 1 is used for toasting the plastic sheeting be placed on plastic sheeting baking position 2, cover in template by becoming the plastic sheeting 3 of mecystasis, vital qi pump interface 4 connects with true air pump, is bled by each aspirating hole 5;

2) coat;

3) as shown in Figure 3, the sandbox 6 with filtering suction pipe 7 is placed on has covered in the template of plastic sheeting;

4) as shown in Figure 3, in sandbox 6, fill drystone sand and do not contain binding agent in drystone sand, microseism makes drystone sand consolidation, strike off, put sealing film 8, open valve and pump air in molding sand, make to there is pressure differential inside and outside casting mold, casting mold external and internal pressure difference is the Arbitrary Digit between 300-400mmHg, comprises 300mmHg and 400mmHg two end values; Use due to pressure differential makes casting mold shaping and has higher hardness, and green mold hardness tester reading can reach about 95;

5) separate the vacuum in removing template, then carry out withdrawing pattern, obtained mo(u)ld top half;

6) according to above-mentioned steps 1) to 5) mo(u)ld bottom half processed;

7) as shown in Figure 4, lower core 9, mould assembling, cast; Vital qi pump interface 11 and the even true air pump of vital qi pump interface 12 connect, and gas moves along airway 10.

8) after metal freezing, stop bleeding to casting mold, in type during pressures near atmospheric, casting mold is just defeated and dispersed voluntarily and obtain foundry goods.

The present invention utilizes plastic sheeting to seal sandbox, by air in vacuum-pumping system extraction type, has pressure differential inside and outside casting mold, make drystone sand closely knit, form required die cavity, vacuumize make casting solidification through lower core, mould assembling, cast, remove negative pressure, molding sand is thereupon defeated and dispersed and obtain foundry goods.By exploitation and the application of this technology, quality and the production efficiency that can increase substantially product reduce manufacturing cost simultaneously and realize the manufacturing technique requirent of energy-saving and emission-reduction.

Last it is noted that the foregoing is only the preferred embodiments of the present invention; be not limited to the present invention; for a person skilled in the art; it still can regulate the technical scheme described in foregoing embodiments; or equivalent replacement is carried out to wherein portion of techniques feature; within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (2)

1. a V method casting technique, is characterized in that comprising the following steps:

1) by baking in the covered rearing with plastic film of mecystasis in template, vavuum pump is bled, and that film is closely attached in template is shaping;

2) coat;

3) sandbox with filtering suction pipe is placed on has covered in the template of plastic sheeting;

4) in sandbox, fill drystone sand and do not contain binding agent in drystone sand, microseism makes drystone sand consolidation, strikes off, puts sealing film, opens valve and pumps air in molding sand, makes to there is pressure differential inside and outside casting mold;

5) separate the vacuum in removing template, then carry out withdrawing pattern, obtained mo(u)ld top half;

6) according to above-mentioned steps 1) to 5) mo(u)ld bottom half processed;

7) core, mould assembling, cast under;

8) after metal freezing, stop bleeding to casting mold, in type during pressures near atmospheric, casting mold is just defeated and dispersed voluntarily and obtain foundry goods.

2. a kind of V method casting technique according to claim 1, is characterized in that: in step 4), and casting mold external and internal pressure difference is 300-400mmHg.