CN102476165A

CN102476165A - Method for manufacturing hand-molded special-shaped exhaust hole in sand casting

Info

Publication number: CN102476165A
Application number: CN2010105610585A
Authority: CN
Inventors: 王意; 陈财坤
Original assignee: Guangxi Yuchai Machinery Co Ltd
Current assignee: Guangxi Yuchai Machinery Co Ltd
Priority date: 2010-11-23
Filing date: 2010-11-23
Publication date: 2012-05-30

Abstract

The invention discloses a method for manufacturing a manually molded special-shaped exhaust hole in sand casting, which is used for manufacturing the exhaust hole when the combined manufacturing can not finish the separated demoulding and comprises the following steps: trimming the polystyrene foam by a cutter to be made into the shape of the special-shaped exhaust hole; placing the trimmed polystyrene foam with the shape of the exhaust hole at the position of the air hole to be formed; filling and compacting molding sand; when molten iron is poured, the polystyrene foam in the shape of the exhaust holes is automatically melted under the action of high-temperature airflow to form the required special-shaped exhaust holes. The invention effectively solves the problem that the vent holes with special shapes can not be demoulded when being manufactured in the prior art by the high-temperature self-melting principle of the polystyrene foam, and can improve the emission of gas generated in the pouring process, thereby reducing the higher rejection rate caused by higher occurrence rate of casting pores.

Description

The preparation method of hand moulding abnormal row pore in the sand casting

Technical field

The present invention relates to the sand casting field, particularly a kind of preparation method of hand moulding abnormal row pore.

Background technology

Casting mold can produce gases such as CO, SO2 when manual sand casting was poured into a mould, and in order to make the casting mold exhaust happier, reduced the pore waste product of foundry goods, need in sand mold, add the steam vent of some.Scheme of the prior art is generally: 1, through-type up and down steam vent directly is placed in the sand mold with wall scroll awl column pore pin (wooden or iron) usually, and moulding is taken out the formation pore with it after finishing; 2, L shaped steam vent usually makes up according to the mode of scheme 1 with 2 awl column pore pins (wooden or iron) and makes, and separates the demoulding after accomplishing.

When if the steam vent position is more special, for example need make L shaped steam vent, as shown in Figure 1, operational version 1 described method obviously can't be carried out, and then this position can't exhaust; If operational version 2, when L2＜L3, exhaust needle demoulding distance is not enough, can't accomplish the demoulding.L type steam vent during therefore to L2＜L3 or other can't the demoulding the abnormal row pore, adopt the method for prior art to carry out, thereby can increase the pore waste product of foundry goods.

Summary of the invention

The present invention is in order to overcome defective in the above-mentioned prior art, when providing a kind of pore pin demoulding distance not enough, still can to accomplish the method that the abnormal row pore is made smoothly.

The preparation method of hand moulding abnormal row pore in the sand casting of the present invention is used to make up making and can't accomplishes the steam vent making when separating the demoulding, comprises the steps: through cutter the polystyrene foam finishing to be made into the shape of said abnormal row pore; The polystyrene foam with steam vent shape after the finishing is placed and needs the pore of moulding position; Fill and the consolidation molding sand; During molten iron pouring, the polystyrene foam of steam vent shape melts the abnormal row pore that formation needs automatically under the effect of high temperature gas flow.

Wherein, the abnormal row pore is the L type, and the monolateral demoulding of L type is stepped down length L 2 less than the corresponding monolateral steam vent length L 3 of L type.

Preferably, the cross sectional shape of the polystyrene foam of finishing final vacuum hole shape is a rectangle.

Compared with prior art, the present invention has following beneficial effect:

1, through the molten certainly principle of polystyrene foam high temperature; Problem that can't the demoulding when steam vent that efficiently solves some special shape in the prior art is made; Can improve producing gas purging in the casting process, the higher percent defective that causes thereby the incidence of reduction bleb is higher;

2, technology is simple, and is easy to make, and the cost of material is low.

Description of drawings

Fig. 1 is the molding sand structural upright sketch map that the present invention has L type steam vent;

Fig. 2 is the molding sand structural front view that the present invention has L type steam vent;

Fig. 3 is that the A-A of Fig. 2 is to cutaway view.

In conjunction with the accompanying drawing following Reference numeral of mark above that:

The 1-molding sand, 2-L type steam vent.

The specific embodiment

Below in conjunction with accompanying drawing, a specific embodiment of the present invention is described in detail, but is to be understood that protection scope of the present invention does not receive the restriction of the specific embodiment.

Extremely shown in Figure 3 like Fig. 1; The preparation method of hand moulding abnormal row pore in the sand casting of the present invention is used for the steam vent of the scheme 2 that background technology introduces (being that the monolateral demoulding among Fig. 3 is stepped down length L 2 during less than monolateral steam vent length L 3) when combination is made and can't be accomplished the separately demoulding and makes.

This preparation method comprises the steps:

Step 1 is repaired polystyrene foam the shape (for ease of making, the cross sectional shape of the polystyrene foam of finishing final vacuum hole shape can be processed rectangle) that is made into L type steam vent 2 among Fig. 3 through cutter;

Step 2 places the polystyrene foam with L type steam vent shape after the finishing to need the pore of moulding position;

Step 3 is filled and consolidation molding sand 1;

Step 4, during molten iron pouring, the polystyrene foam of L type steam vent shape melts the L type steam vent 2 that formation needs automatically under the effect of high temperature gas flow.

After moulding by casting and the cooling, the residual iron charge that former steam vent position is formed beats and handles through polishing and can form complete foundry goods.

The above embodiment of the present invention is that example describes with L type steam vent, and the steam vent of other special-shaped shape is made being difficult for also can adopting to use the same method under the situation of the demoulding certainly; For the core core print exhaust of specific position, also can adopt similar method in addition.

The preparation method of abnormal row pore of the present invention is through the molten certainly principle of polystyrene foam high temperature; Problem that can't the demoulding when steam vent that efficiently solves some special shape in the prior art is made; Can improve producing gas purging in the casting process, the higher percent defective that causes thereby the incidence of reduction bleb is higher; Technology is simple, and is easy to make, and the cost of material is low.

More than disclosedly be merely a specific embodiment of the present invention, still, the present invention is not limited thereto, any those skilled in the art can think variation all should fall into protection scope of the present invention.

Claims

1. the preparation method of hand moulding abnormal row pore in the sand casting, the steam vent when being used to make up making and can't accomplishing the separately demoulding is made, and it is characterized in that, comprises the steps:

The polystyrene foam finishing is made into the shape of said abnormal row pore through cutter;

The polystyrene foam with steam vent shape after the finishing is placed and needs the pore of moulding position;

Fill and the consolidation molding sand;

During molten iron pouring, the polystyrene foam of said steam vent shape melts the said abnormal row pore that formation needs automatically under the effect of high temperature gas flow.

2. the preparation method of hand moulding abnormal row pore is characterized in that in the sand casting according to claim 1, and said abnormal row pore is the L type, and the monolateral demoulding of L type is stepped down length L 2 less than the corresponding monolateral steam vent length L 3 of L type.

3. the preparation method of hand moulding abnormal row pore is characterized in that in the sand casting according to claim 1 and 2, and the cross sectional shape of the polystyrene foam of said finishing final vacuum hole shape is a rectangle.