CN86209099U

CN86209099U - Centre-hollow sand core for casting with thin wall

Info

Publication number: CN86209099U
Application number: CN 86209099
Authority: CN
Inventors: 刘建国
Original assignee: SHENYANG HIGH AND MIDDLE PRESS
Current assignee: SHENYANG HIGH AND MIDDLE PRESS
Priority date: 1986-11-13
Filing date: 1986-11-13
Publication date: 1987-10-07

Abstract

The utility model relates to a centre-hollow sand core for casting with a thin wall, which is used to found the sand core of centre-hollow castings, like a case body, a valve body, a cylinder body, a box body, etc. The utility model is composed of thin wall hollow core grid, fiber material layer and a core sand layer. The centre-hollow sand core for casting with the thin wall has excellent air exhaust effect and higher collapsibility. Cracks and air holes defect of the castings can be eliminated. Simultaneously, cost is saved by 70-90% than a traditional core making process. The utility model has the advantages of small cleaning amount and easy cleaning and high precision of the castings.

Description

Centre-hollow sand core for casting with thin wall

The utility model is the thin-walled hollow core that hollow castings such as cast housing, valve body, casing, cylinder body are used.

Making hollow casting at present, is with foundry sand and a certain amount of binding agent, and materials such as curing agent mix the molding sand of system and are lowered to casting mold as the solid sand core that the arbor of core sand skeleton is made, and cast forms.There is following problem in this core: coremaking is big with sand and disposable cast iron arbor consumption; The production cycle and the drying time of core are long; Easily produce casting flaws such as casting crack and pore.Big-and-middle-sized hollow casting adopts to divide more partly makes the combined type core, and the core apposition position has overlap, and burr is smooth inadequately bright and clean, and the dimensional accuracy of foundry goods is not good, and it is big to remove arbor and desanding workload, worsens operating environment.

Through service center of patent office searching retrieval, the clear and 55-153650(1980 of Japan) November 29 invention disclosed, there is following problem in the manufacture method that name is called hollow casting:

1, Japan Patent is to produce earlier and the essentially identical thin-walled hollow object of hollow casting cavity shape, after the casting; the thin-walled hollow object retains among the hollow casting; as the surface of internal cavity of foundry goods; hollow casting of its every casting then just needs thin-walled hollow object identical with the hollow casting inner chamber of processing, and its cost is inevitable high.

2, Japan Patent can only be made general small hollow foundry goods, and can not cast big-and-middle-sized hollow pressure container type foundry goods.

It is low that the purpose of this utility model provides a kind of cost, and can improve the thin-walled hollow core of hollow casting quality.The shaping of producing once of the arbor of this thin-walled hollow core can recycle for a long time, reduces cost.

The utility model is achieved in that at first and makes and the essentially identical hollow thin-wall arbor of hollow casting cavity shape, according to the size and the cavity shape complexity of hollow casting, it be made one or several split member earlier, engages then to form.Its material is to adopt metal sheet, uses roll bending, and methods such as compacting or panel beating are shaped, and are welded with electric welding or soldering then.For the ease of exhaust in the casting.Hollow arbor perisporium is provided with a large amount of steam vents.The outer surface of the thin-walled hollow arbor of making is uniform lay one deck fibrous material after, place it in the core box, on the fibrous material surface

System skim core sand layer.

Fibrolaminar fibrous material in this thin-walled hollow core can be an organic fibrous material, also can be inorganic fibers.

The arbor of this thin-walled hollow core, fibrous material layer, with the thickness of thin core sand layer can be different and different with shape according to the size of foundry goods.

The utlity model has good exhaust effect and higher deformability, cast hollow casting, can eliminate the crackle and the gas hole defect of foundry goods effectively, and can improve the dimensional accuracy of foundry goods with it.Cast cleaning is also very convenient, and core cavity core sand residual volume is less, removes a little to get final product.Because adopt the thin-walled hollow core, its sand using amount greatly reduces, and saves a large amount of cast iron arbors, make cost reduce by 70～90%.

The utility model is provided by following examples and accompanying drawing thereof:

Fig. 1 is a longitudinal sectional view of the present utility model.

Fig. 2 is the cutaway view of the utility model along the A-A line.

Fig. 3 is that the master of embodiment 2 looks cutaway view.

Now describe CONSTRUCTED SPECIFICATION of the present utility model and working condition in detail in conjunction with Fig. 1～3.

Present embodiment 1 is the thin-walled hollow core that a casting large-scale flat gate valve is used.The large flat gate valve body foundry goods of casting, blank weight 2100kg, poured weights 4070kg, thickest 135mm, full-size 1700mm, material are WCB.According to the cavity shape of this foundry goods, make three thin-walled hollow arbors earlier; In Fig. 1～2 1,6,12 are exactly the arbor that is used for the thin-walled hollow core of casting large-scale flat gate valve valve body.When making the thin-walled hollow core, calculate arbor thickness, fiber layer thickness and core sand layer thickness at first respectively, arbor thickness 6mm, fiber layer thickness 20mm, core sand layer thickness are 30～50mm.

After THICKNESS CALCULATION is intact, select suitable steel plate, after employing roll bending, compacting and the panel beating, make the thin-walled hollow arbor with welding and method for welding.For in casting process, having good exhaust performance, on the arbor perisporium, be processed with a large amount of steam vents.Then, on arbor, lay the fibrous material of 20mm thickness.2,7,11 is fibrage in Fig. 1～2.After having laid fibrage above the arbor, place it in the core box, on fibrage

Make the core sand layer of a bed thickness 30～50mm.In Fig. 1～2 3,8,10 are thin core sand layer segment, and three thin-walled hollow cores making are lowered to casting mold by the position that indicates in Fig. 1～2, among Fig. 1～Fig. 2 the 5,13, the 14th, and the hollow parts of thin-walled hollow core.After the mould assembling, inject molten metal by cast gate and produce required foundry goods.During cast, the steam vent that the gas that core produces can all waltz through above the thin-walled hollow arbor is discharged from inner chamber is hollow.Avoided the gas hole defect of foundry goods effectively.The solid sand core that this kind foundry goods adopts traditional arbor to make, the foundry goods of cast, the foundry goods quantity that produces pore accounts for 40% of total foundry goods quantity.Because uniform one deck fibrous material that lays above the utility model, in molten metal solidification shrinkage process, its deformability of thin-walled hollow core is good, therefore, can avoid foundry goods to crack.The foundry goods that the solid sand core that in the past adopted traditional arbor to make is poured into a mould, its crackle rate accounts for 50～60% of foundry goods sum.In sum, adopt the foundry goods of the utility model casting, can eliminate the defective of crackle and pore fully.4,9 foundry goods that are to use the utility model to pour into a mould in Fig. 1～2.

This thin-walled hollow core has the fast characteristics of core cavity cooling velocity than traditional solid sand core cast in the casting pouring process, help solidifying rapidly of foundry goods, therefore can suitably reduce rising head.

Embodiment 2

Fig. 3 is the thin-walled hollow core that the casting large shell casting is used.The shell casting material is WCB, and blank weight is 1200kg, and poured weights is 2100kg, and full-size is 1320mm, and thickest is 90mm.

At first by the cavity shape of foundry goods shown in Figure 3,4 the thin-

walled arbor members

1,2,3,4 that are built in sections form with the method for sheet metal through roll bending, compacting and panel beating earlier, use electric welding solder joints one then.On the arbor perisporium of making, be processed with a large amount of steam vents, and at the uniform one deck fibrous material that lays of the outer surface of arbor.5 is the fibrages that lay among Fig. 3.Place it in the core box then

System one deck core sand layer 6.

Arbor steel plate

1,2,3, the 4 thickness 5mm that indicate of Fig. 3 wherein, fibrage 5 is thick to be 15mm, core sand layer 6 thickness are 35～40mm.

The thin-walled hollow core that makes is lowered to casting mold, after the mould assembling, injects the WCB molten steel, behind the casting solidification, extract arbor out from foundry goods one end from cast gate, a small amount of core sand that core cavity is residual, removing gets final product a little.7 is foundry goods among Fig. 3, the 8th, and the hollow parts of thin-walled hollow core.

The utility model is applicable to steel-casting, ironcasting or other metal casting of hollow.

Claims

1, a kind of core that is used for the casting metal hollow casting is characterized in that it being the thin-walled hollow core, is made up of the arbor 1 that is processed with steam vent on the perisporium, fibrous material layer 2,3 on core sand layer.

2, thin-walled hollow core according to claim 1 is characterized in that it can make several thin-walled hollow arbor members corresponding to the cavity shape of hollow casting, is bonded into one then, makes the arbor of complete thin-walled hollow core.