CN102873272B

CN102873272B - Patternless sand mould numerical-control machining method by coating sand in iron mould

Info

Publication number: CN102873272B
Application number: CN201210376097.7A
Authority: CN
Inventors: 单忠德; 康怀镕; 刘丰; 吴晓川; 顾兆现
Original assignee: Advanced Manufacture Technology Center China Academy of Machinery Science and Technology
Current assignee: Advanced Manufacture Technology Center China Academy of Machinery Science and Technology
Priority date: 2012-10-08
Filing date: 2012-10-08
Publication date: 2015-01-21
Anticipated expiration: 2032-10-08
Also published as: CN102873272A

Abstract

The invention discloses a patternless sand mould numerical-control machining method by coating sand in an iron mould. The patternless sand mould numerical-control machining method by coating the sand in the iron mould includes the steps: building a CAD (computer-aided design) model of a required sand mould; extracting the contour of a cavity of the sand mould, optimizing the contour and building a sand billet CAD model; accumulating molding sand (2) in the iron mould (1) according to the sand billet CAD model; tamping the molding sand, and measuring and repairing the sand billet until the size of the sand billet is close to that of the CAD model; and performing numerical control machining for the sand billet to achieve molding of the sand mould after the sand billet in the iron mould is cured. The patternless sand mould numerical-control machining method by coating the sand in the iron mould has the advantages of simple process, easiness in implementation, low pollution and high efficiency.

Description

A kind of non-model sand mold digital control processing manufacturing process of device for sand coated iron mould

Technical field

The present invention relates to a kind of non-model sand mold forming method of the device for sand coated iron mould cast, belong to cast form field.

Background technology

Device for sand coated iron mould casting utilizes low-pressure compressed air fluidised form precoated sand to be blown into swage with the heating of type and mold cavity, makes evenly to be covered with one deck 5 ~ 8mm heat cure molding sand in die cavity and a kind of casting technique of forming casting mold.Because device for sand coated iron mould mold stiffness is good and to cover layer of sand thinner, foundry goods cooling velocity is fast, and sand fineness is thin, therefore can significantly improve the dimensional accuracy of foundry goods, compactness, surface quality, the degree of refinement of crystal grain and Oxygen potential, can realize head-free casting simultaneously.Be widely used in some foundry goods that casting technique difficulty is larger, as foundry goods such as bent axles.

Device for sand coated iron mould need process corresponding mould in advance according to different foundry goods, and higher owing to making die cost, the cycle is long, and therefore device for sand coated iron mould is only applicable to the manufacture of foundry goods in enormous quantities, is not suitable for the manufacture of single and mini-batch production foundry goods.Device for sand coated iron mould needs heat swage and swage in advance and control to carry out at a certain temperature, to ensure that the sand injected can solidify and not coking.Swage exhaust needs exhaust during device for sand coated iron mould sandblasting simultaneously and avoids running sand, if freely certainly will not cause penetrate the defect such as deficiency, tympanites; If Double layer iron intermode is closed not tight after matched moulds, then easily occur running sand.In actual production due to swage casting processing after have stress deformation, swage constantly heat cooling produce distortion and swage upper surface collide with all can make to penetrate sand time swage upper surface and penetrate sand plate lower plane produce gap, when penetrating sand, sand is run out of from gap, causes environmental pollution and waste sand.

Summary of the invention

For the deficiency of existing device for sand coated iron mould technique, the present invention proposes a kind of non-model sand mold digital control processing manufacturing process of device for sand coated iron mould, be intended to solve adopt the existing device for sand coated iron mould manufacture technics single and mini-batch production foundry goods cycle long, cost is high, the problem of complex process.

The technical solution adopted for the present invention to solve the technical problems is to achieve these goals: a kind of sand mold digital control processing manufacturing process of device for sand coated iron mould, and the method comprises following step:

1. the cad model of required sand mold is set up;

2. sand mold die cavity profile is extracted; Optimize profile, set up sand base cad model;

3. according to sand base cad model, molding sand (2) is deposited in swage (1);

4. use tamper (3) to carry out tamping to the molding sand in swage, form sand base;

5. measure sand base size, repair sand base, then tamping, until sand base size is close to its cad model size;

6. drying carried out to the sand base in swage and treat that it solidifies;

7. carry out digital control processing to the sand base in swage to be shaped to sand mold.After casting pouring is shaped, take out foundry goods, the molding sand in cleaning swage, reclaims swage.

Described extraction sand mold die cavity profile is that the principle that should be less than actual sand mold cavity dimension according to extracted overall size is extracted.

Described optimization profile is removed in the concave, convex not easily adopting stacking method to be formed in profile, position, tip.

Described swage (1) is the swage with pit inner surface and conical internal cavity.

Described is deposited in swage by molding sand, is when without mould, uses artificial or mechanical method to pile up, and guarantees that swage inwall is all coated with certain thickness molding sand.

Described tamping is until sand base size is close to its cad model size, and after should guaranteeing tamping, the cavity dimension of sand base is equal to or less than its cad model size, stays allowance to give the follow-up processing to sand base.

The present invention has following advantage compared with existing device for sand coated iron mould sand mold manufacturing process:

Simplify sand mold forming technology.Because this method does not need to make swage in advance, do not carry out the complicated technology such as heating to swage, swage, therefore greatly simplifie sand mold forming technology.

Avoid aggravating working environment.Because this method does not adopt sandblasting operation, avoid the contingent race sand of sandblasting operation in device for sand coated iron mould, the accidents such as aggravating working environment.

Shorten the sand mold manufacturing cycle, reduce costs.Because this method does not use swage, therefore do not need to make corresponding swage for different foundry goods, while shortening the sand mold manufacturing cycle, also reduce the cost that sand mold manufactures.

The present invention compares with existing non-model sand mold digital control processing manufacturing process has following advantage:

Considerably reduce the processing capacity of sand mold, improve efficiency, save material.

Accompanying drawing explanation

Figure of description is for a foundry goods so that the technical process of the non-model sand mold digital control processing manufacturing process of this device for sand coated iron mould to be described, and non-limiting application range of the present invention.

In figure:

Fig. 1 is the die cavity profile of sand mold needed for extraction of the present invention, optimization set up the implementation process schematic diagram of the cad model of sand base.

Fig. 2 is the implementation process schematic diagram of accumulation molding sand of the present invention, tamping, solidification, digital control processing shaping.

In figure:

1------swage 2------molding sand 3------tamper

Detailed description of the invention

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is further described.

Set up sand mold as shown in Figure 1, extract sand mold die cavity profile (in Fig. 1 shown in dotted line), remove profile concave, convex part, replace straight line, set up sand base cad model.

As shown in Figure 2, according to the cad model of sand base, use artificial or mechanical method, molding sand is stacked in swage, and guarantee that swage inside is all coated with certain thickness molding sand.

Tamping is carried out to the molding sand in swage, comprises the tamping to cavity bottom and sidewall, form sand base.

Measure the approximate size of sand base, supplement molding sand or remove unnecessary molding sand, then tamping, make sand base cavity dimension be equal to or slightly less than its cad model size.

Drying process is carried out to sand base, treats its curing molding.

Digital control processing is carried out to the sand base in swage, obtains sand mold.To be cast complete after, take out foundry goods and sand mold, reclaim swage.

The above is preferred embodiment of the present invention, and is not used to limit application range of the present invention, and under all other do not depart from disclosed essence, the equivalence that completes changes, and is evenly included in right of the present invention.

Claims

1. a non-model sand mold digital control processing manufacturing process for device for sand coated iron mould, the method comprises following step:

1. the cad model of required sand mold is set up;

2. extract sand mold die cavity profile, optimize profile, set up sand base cad model;

5. measure sand base size, repair sand base, then tamping, until sand base size is close to its cad model size; 6. drying carried out to the sand base in swage and treat that it solidifies;

7. carry out digital control processing to the sand base in swage to be shaped to sand mold;

8. after casting pouring is shaped, take out foundry goods, remove molding sand, reclaim swage.

2. the non-model sand mold digital control processing manufacturing process of device for sand coated iron mould according to claim 1, is characterized in that, described extraction sand mold die cavity profile, is that the principle that should be less than actual sand mold cavity dimension according to extracted overall size is extracted.

3. the non-model sand mold digital control processing manufacturing process of device for sand coated iron mould according to claim 1, is characterized in that, described optimization profile, is to be removed in the concave, convex not easily adopting stacking method to be formed in profile, position, tip.

4. the non-model sand mold digital control processing manufacturing process of device for sand coated iron mould according to claim 1, is characterized in that, described swage (1) is the swage with pit inner surface and conical internal cavity.

5. the non-model sand mold digital control processing manufacturing process of device for sand coated iron mould according to claim 1, it is characterized in that, described is deposited in swage by molding sand, is when without mould, use artificial or mechanical method to pile up, and guarantee that swage inwall is all coated with certain thickness molding sand.

6. the non-model sand mold digital control processing manufacturing process of device for sand coated iron mould according to claim 1, is characterized in that, described tamping is until sand base size is close to its cad model size, and after should guaranteeing tamping, the cavity dimension of sand base is equal to or less than its cad model size.