CN203556794U

CN203556794U - Green sand casting molding structure

Info

Publication number: CN203556794U
Application number: CN201320762412.XU
Authority: CN
Inventors: 王德福; 黎孔金; 郑英平
Original assignee: YIDU CHANGPENG MACHINERY MANUFACTURING CO LTD
Current assignee: YIDU CHANGPENG MACHINERY MANUFACTURING CO LTD
Priority date: 2013-11-28
Filing date: 2013-11-28
Publication date: 2014-04-23
Anticipated expiration: 2023-11-28

Abstract

The utility model discloses a green sand casting molding structure which comprises an upper tank mold and a lower tank mold. Back sand is placed at the bottom of the lower tank mold, a built-in casting model is arranged between the upper tank mold and the lower tank mold, pre-coated sand covers the periphery of the casting model, and facing sand is arranged on the upper portion of the pre-coated sand positioned in the upper tank mold. The thickness of the pre-coated sand ranges from 3mm to 4mm. The green sand casting molding structure has the advantages that the green sand casting molding structure is improved, so that quality requirements on products can be met; a precision casting effect can be realized by the common casting molding structure, and the production cost of the green sand casting molding structure is lower than pre-coated sand production cost.

Description

A kind of wet sand casting modeling structure

Technical field

The utility model relates to casting technology field, specifically a kind of wet sand casting modeling structure.

Background technology

Wet sand casting is that in foundry industry, one is the most common, adopts the most general Modeling Technology.It is high that it has production efficiency, with short production cycle, and the cost of material is low, and deformability is better, is convenient to the advantages such as knockout.But greensand mold is when cast, and water translocation and gasification appear in sand mold surface, make foundry goods easily produce the casting defects such as pore, burning into sand, sand holes, the sand that rises, scab.Therefore, green sand molding is generally only limited to the moulding of common parts.Higher for required precision, foundry goods requires the parts production of zero-fault to have certain difficulty.As: engine flywheel, part is non-machined surface, product needed is examined dynamic balancing entirely.Outer machined surface is marked with intensive printed words, requires the product of casting and processing dimension zero-fault, just cannot produce to realize product quality requirement with traditional greensand mold moulding.General precoated sand casting and the device for sand coated iron mould of adopting produced.After adopting precoated sand core shooter to produce shell group mould, pour into a mould, the method is produced easily and is realized, but precoated sand cost is high.The 2nd, adopt device for sand coated iron mould to produce, production efficiency is high, but disposable input is quite large.

Utility model content

For solving the problems of the technologies described above, the utility model provides a kind of wet sand casting modeling structure, by wet sand casting modeling structure is improved, realizes product quality requirement.With conventional cast modeling structure, reach the effect of hot investment casting, production cost is lower than precoated sand production cost.

The technical scheme that the utility model is taked is: a kind of wet sand casting modeling structure, comprise box, lower box, floor sand is placed in lower box bottom, built-in casting pattern between upper box and lower box, casting pattern surrounding covers and is provided with precoated sand, and the precoated sand top that is positioned at box is provided with facing sand.Described precoated sand thickness is: 3 ~ 4mm.

A kind of wet sand casting formative method, comprises the following steps:

Water and bentonite are as binding agent, and mixed precoated sand processed, adds bentonite 8%, adds water 4.5% in precoated sand, and mixed preparation is used;

The precoated sand that mixed preparation is made good use of covers 3 ~ 4mm by casting pattern;

Add successively facing sand, floor sand; Vibrations moulding, the demoulding;

With liquefied gas, to die cavity inwall heating cure 1 ~ 2 minute, make the rear mould assembling of precoated sand sclerosis of mixed system, forming in chamber is the type body for fluffing of moulding sand type outside gravity die, chamber, and outer die cavity is as the carrier of inner chamber.

A kind of wet sand casting modeling structure of the utility model, has the following advantages:

The utility model is by the process modification to greensand mold structure, realizes product quality requirement, uses conventional cast modeling structure, reaches the effect of hot investment casting.Production cost is lower than precoated sand production cost, and foundry goods per ton only molding sand cost just can reduce nearly 1,000 yuan.Owing to being die, dryness in die cavity, outside chamber, be greensand mold carrier, sand mold has higher intensity, can overcome the defects such as general wet sand casting buckle, also can guarantee the physical dimension of part completely.In chamber in the precoated sand of the dry type sclerosis of thick 3 ~ 4mm left and right containing certain resin, progressively burning after moulding by casting, the gas in molding sand is easily discharged, product can not produce that sand is swollen, pore, scab, burning into sand defect.

Accompanying drawing explanation

Below in conjunction with drawings and Examples, the utility model is described in further detail:

Fig. 1 is a kind of wet sand casting modeling structure of the utility model schematic diagram.

The specific embodiment

As shown in Figure 1, a kind of wet sand casting modeling structure, comprise box 1, lower box 2, floor sand 3 is placed in lower box 2 bottoms, the built-in casting pattern 4 in middle part between upper box 1 and lower box 2, casting pattern 4 surroundings cover and are provided with precoated sand 5, and precoated sand 5 tops that are positioned at box 1 are provided with facing sand 6.Described precoated sand 5 thickness are: 3 ~ 4mm.

Molding sand material is prepared:

(1), floor sand 3: it is identical with traditional damp sand technique to join sand technique.

(2), facing sand 6: it is identical with traditional damp sand technique to join sand technique.

(3), mixed precoated sand 5 processed: water and bentonite, as binding agent, mix precoated sand 5 processed.

Compound method:

The precoated sand of market supply is added to bentonite 8%, adds water 4.5% by weight (precoated sand 87.5%), standby with the mixed precoated sand 5 processed of puddle mixer.

Formative method:

1), with the precoated sand 5 of preparation, casting pattern 4 is covered to 3 ~ 4mm.

2), add successively facing sand 6, floor sand 3.

3), vibrations moulding, the demoulding;

4), with liquefied gas to die cavity inwall heating cure 1 ~ 2 minute, make mould assembling after precoated sand 5 sclerosis of mixed system, forming in chamber is gravity die, is the type body of fluffing of moulding sand type outside chamber, outer die cavity is as the carrier of inner chamber.

In chamber in the precoated sand 5 of the dry type sclerosis of thick 3 ~ 4mm left and right containing certain resin, progressively burning after moulding by casting, the gas in precoated sand 5 is discharged by steam vent 7, product can not produce that sand is swollen, pore, scab, burning into sand defect.

Claims

1. a wet sand casting modeling structure, comprise box (1), lower box (2), it is characterized in that, floor sand (3) is placed in lower box (2) bottom, built-in casting pattern (4) between upper box (1) and lower box (2), casting pattern (4) surrounding covers and is provided with precoated sand (5), and precoated sand (5) top that is positioned at box (1) is provided with facing sand (6).

2. a kind of wet sand casting modeling structure according to claim 1, is characterized in that, described precoated sand (5) thickness is: 3 ~ 4mm.