CN212822513U

CN212822513U - Precision casting's casing

Info

Publication number: CN212822513U
Application number: CN202021288897.XU
Authority: CN
Inventors: 吴振行; 李冬
Original assignee: Lianyungang Yuanyu Metal Products Co ltd
Current assignee: Lianyungang Yuanyu Metal Products Co ltd
Priority date: 2020-07-02
Filing date: 2020-07-02
Publication date: 2021-03-30
Anticipated expiration: 2030-07-02

Abstract

The utility model discloses a precision casting's casing, including the die cavity, form the inner membrance shell of die cavity and the supporter outside the inner membrance shell of parcel, be equipped with bleeder vent and/or gas passage that can spill the gas in the inner membrance shell in the supporter. The utility model discloses after soaking thick liquid, the sand soaking on the prototype part earlier, as the inner membrane shell, the granule of fine thick liquids is exquisite and the combination of prototype surface is firm, is difficult for producing bubble, swell, after forming the casting die cavity, inner membrane shell and casting surface contact in the follow-up casting process, can improve the casting precision; the inner membrane shell is also coated with a supporting body to support the inner membrane shell, so that the strength of the cast shell is improved, the capability of resisting the expansion caused by heat and the contraction caused by cold of an original piece of the cast shell during high-temperature sintering demoulding is enhanced, and the problem that the cast shell is cracked or broken during sintering demoulding is solved.

Description

Precision casting's casing

Technical Field

The utility model belongs to the precision casting field, concretely relates to precision casting's casing.

Background

Precision casting is a new advanced process of near net shape forming, which is a manufacturing method of obtaining a casting by coating a plurality of layers of refractory materials on the surface of a mould, melting off a prototype part in the mould after hardening and drying to prepare a shell, roasting, and then pouring. The product obtained by the method is precise and complex, is close to the final shape of a part, can be directly used without processing or with little processing, and has very wide application.

The 3D printing technology is an emerging technology in the manufacturing industry field that is rapidly developing, and the manufacturing principle of the 3D printing technology is based on the idea of additive manufacturing, which is a technology for manufacturing an object by a print head, a nozzle or other printing deposition technology, mainly comprising SLA, FDM, SLS, LOM, and the like.

The 3D printing technology is applied to development and manufacturing of the die, can adapt to the diversity of die structures, can be quickly manufactured, and is relatively low in cost; 3D printing and precision casting are combined, so that the precision and efficiency of cast products can be greatly improved, and the production period is shortened.

However, in the prior art, the materials used for 3D printing are various, and when a prototype part for 3D printing is used for precision casting, in the step of sintering and demolding a casting shell, because the material forming the prototype part expands due to heat during high-temperature sintering, a refractory layer shell is very easy to crack due to expansion caused by heat and contraction caused by cold of the prototype part during sintering, and in the prior art, the method of changing the material of the prototype part is mostly adopted to solve the problem, but the cost is very high. In addition, the shell composed of a plurality of layers of refractory materials needs to be removed from the casting after pouring is completed, but the existing shell structure is hard and difficult to break, and the difficulty of removing work is increased.

Disclosure of Invention

The utility model discloses not enough to break easily when present precision casting shell sintering drawing of patterns provides a precision casting's casing, has reduced the number of piles that soaks the thick liquid, breakage rate when having reduced the sintering of casting casing.

In order to realize the purpose, the utility model discloses a technical scheme as follows:

a precision cast housing characterized by: the air-permeable membrane comprises a cavity, an inner membrane shell forming the cavity and a support body wrapped outside the inner membrane shell, wherein air holes and/or air channels capable of diffusing air in the inner membrane shell are formed in the support body.

Further, the thickness of the inner membrane shell is 0.5-5 mm.

Further, the support body has a thickness of at least 10 mm.

Further, the inner membrane shell is formed by soaking 2-6 layers of pulp.

Further, the support includes gypsum and pores uniformly dispersed in the gypsum.

Further, the porous object is volcanic rock.

Further, the support body is formed by sintering gypsum and combustible materials at high temperature, and the combustible materials are foam or sponge or wood chips or paraffin blocks or a mixture of any of the foam or the sponge or the wood chips or the paraffin blocks.

Furthermore, the gas channel comprises a gas outlet channel extending from the inner membrane shell to the support body, and the gas outlet channel radially surrounds the periphery of the inner membrane shell.

Furthermore, the gas channel also comprises a surrounding gas channel positioned at the junction of the inner membrane shell and the support body, and the guide gas channel is communicated with the surrounding gas channel.

The technical scheme can obtain the following beneficial effects:

(1) the utility model soaks 2-6 layers of fine slurry on the original piece as the inner membrane shell, the fine slurry has fine particles and firm combination with the surface of the original piece, and is not easy to generate bubbles and bulge, and the inner membrane shell is contacted with the surface of the casting in the subsequent casting process, so that the precision of the casting can be improved; the inner membrane shell is also coated with the supporting body to support the inner membrane shell, so that the strength of the cast shell is improved, the capability of resisting the expansion caused by heat and the contraction caused by cold of an original piece of the cast shell during high-temperature sintering demoulding is enhanced, and the problem that the cast shell is cracked or broken during sintering demoulding is solved.

(2) The support body is internally provided with air holes or air channels, and the air permeability is good. The support body supports the inner membrane shell, and the air holes or the air channels play a role in ventilation, so that gas is prevented from being discharged smoothly during pouring, shrinkage cavities are left on the surface or the core of the casting blank, and the quality of the casting blank is influenced; the support body is a mixture of gypsum and the porous object, and the air holes in the porous object can be used as air holes, so that additional hole making is not needed, and the support body is convenient and simple; the support body is a mixture of gypsum and combustible materials, the combustible materials can be burnt or melted at the sintering temperature, the combustible materials are dispersed in the gypsum, after sintering treatment, the combustible materials are burnt or melted together, original holes are left, the method just utilizes the high temperature of sintering demoulding, no additional hole making step is needed, the design is ingenious, and the air permeability of the support body is enhanced.

Drawings

Fig. 1 is a schematic diagram of the present invention.

In the figure:

1. the device comprises a cavity 2, an inner membrane shell 3, an air channel 31, a leading-out air channel 32, a surrounding air channel 4, air holes 5 and gypsum.

Detailed Description

The invention will be further explained with reference to the drawings:

example 1

As shown in figure 1, the shell for precision casting comprises a cavity 1, an inner membrane shell 2 forming the cavity 1 and a support body wrapped outside the inner membrane shell 2, wherein a vent hole 4 and a gas channel 3 which can diffuse gas in the inner membrane shell 2 are arranged in the support body.

When pouring, the inner surface of the inner membrane shell 2 is in direct contact with the casting to play a role in improving the casting precision, and the support body is not in direct contact with the casting to play a role in supporting the inner membrane shell 2 and enhancing the strength of the casting shell. Set up bleeder vent 4 and gas passage 3 simultaneously in the supporter, bleeder vent 4, gas passage 3 can be with the gaseous casting casing that looses in the inner membrance shell 2, and both use together, and air permeability is better, guarantee the good gas permeability of casting casing, prevent that gas stifled can't get rid of in the casting casing, and then the foundry goods produces quality problems such as shrinkage cavity.

In the preparation the utility model discloses during the casing, at first make with the same prototype spare of foundry goods structure, according to the size of foundry goods and the complexity of shape, soak the thick liquid through 2 ~ 6 layers on the prototype spare and soak the sand and make the inner membrance shell, inner membrance shell thickness is 0.5 ~ 5mm, all adheres one deck fine sand and drying after soaking thick liquid at every turn, the inner membrance shell 2 that forms like this has had certain intensity, has the internal surface smooth again, with the foundry goods contact. Because drying is needed after each time of slurry soaking and sand soaking, the drying process is slow, sometimes requiring one or two days or even longer, and the slurry soaking takes a long time. In the utility model, the number of layers to be soaked is 2-6, which is only half or less than the traditional soaking times, thus greatly saving the soaking time; the thickness of the inner membrane shell 2 is 0.5-5 mm, the thickness is small, and the obtained inner membrane shell 2 has certain strength and can reduce the frequency of slurry soaking and sand soaking.

In this embodiment, in order to facilitate the manufacture of the support body, during the manufacturing, the side surface of the support body is a cylindrical surface, the cavity is approximately arranged at the center of the support body, and the shape of the cavity is irregular, so that the minimum distance from the outer surface of the support body to the inner membrane shell is at least 10mm, and the distances from the rest positions to the inner membrane shell are all greater than the minimum distance, thereby further meeting the strength requirement.

The support body comprises gypsum 5 and porous objects, the porous objects are uniformly dispersed in the gypsum 5, dense air holes are formed in the porous objects, the air holes can play a role of air holes 4, additional hole making is not needed, and the support body is convenient and simple. In this embodiment, the cavernous object is volcanic rock, and volcanic rock is also known as volcanic rock or pumice, is that the volcanic eruption in-process magma is after the rapid cooling, because the sharp reduction of pressure, the inside gas escapes the inflation rapidly and forms a vitreous lava that has intensive gas pocket, just in time satisfies the requirement of cavernous object, in other embodiments, the cavernous object also can be other materials, also is in the utility model discloses a protection scope.

The gas channel 3 comprises an air outlet channel 31 extending from the inner membrane shell 2 to the outside of the support body, and the air outlet channel 31 radially surrounds the periphery of the inner membrane shell. The gas guide channel 31 can guide the gas in the inner membrane shell 2 out of the casting shell, and the gas permeability of the support body is enhanced.

Gas passage 3 still includes the surrounding air flue 32 that is located inner membrane shell 2 and supporter juncture, draws out the gas flue 31 and surrounds air flue 32 UNICOM, and the contact surface that surrounds air flue 32 and inner membrane shell 2 is big, and the gas in inner membrane shell 2 that can bigger area is collected, and the rethread draws out the supporter of gas flue 31 discharge, and both supplement each other, constitute gas passage 3 in the supporter jointly, further strengthen the exhaust performance of supporter.

Example 2

Under other technical characteristics and the same circumstances of embodiment 1, the utility model discloses a precision casting's casing includes die cavity 1, forms die cavity 1's inner membrance shell 2 and the supporter of parcel outside inner membrance shell 2, only is equipped with the bleeder vent that can scatter the gas in the inner membrance shell 2 in the supporter.

The support body is formed by sintering gypsum and combustible materials at high temperature, the combustible materials can be burnt or melted at the sintering temperature, the combustible materials are foam or sponge or sawdust or paraffin blocks or a mixture of any of the foam or the sponge or the sawdust or the paraffin blocks, the materials and the gypsum can be uniformly dispersed everywhere of the gypsum after being stirred and mixed, and the materials and the gypsum can be burnt away in the sintering process, so that holes are left, the holes form air holes, gas can conveniently pass through, and the air permeability of the shell is improved.

Example 3

Under the same circumstances of other technical characteristics and embodiment 1 or 2, the utility model discloses a precision casting's casing includes die cavity 1, forms the interior membrane shell 2 of die cavity 1 and wraps up the supporter outside interior membrane shell 2, only is equipped with the gas passage 3 that can spill the gas in interior membrane shell 2 in the supporter. The gas in the inner membrane shell 2 can be led out of the cast shell, and the gas permeability of the support body is enhanced.

The above description is the preferred embodiment of the present invention, and for those skilled in the art, modifications of the various equivalent forms of the present invention are within the scope of the appended claims of the present application without departing from the principle of the present invention.

Claims

1. A precision cast housing characterized by: including the die cavity, form the inner membrance shell of die cavity and the supporter of parcel outside the inner membrance shell, the inner membrance shell is soaked thick liquid and is soaked the sand through 2 ~ 6 layers and make, the supporter includes the gypsum, be equipped with bleeder vent and/or gas passage that can dispel the gas in the inner membrance shell in the supporter.

2. A precision cast housing according to claim 1, wherein: the thickness of the inner membrane shell is 0.5-5 mm.

3. A precision cast housing according to claim 1, wherein: the support body has a thickness of at least 10 mm.

4. A precision cast housing according to claim 1, wherein: the gas channel comprises a gas leading-out channel extending from the inner membrane shell to the support body, and the gas leading-out channel radially surrounds the periphery of the inner membrane shell.

5. A precision cast housing according to claim 4, wherein: the gas channel also comprises a surrounding gas channel positioned at the junction of the inner membrane shell and the support body, and the guide gas channel is communicated with the surrounding gas channel.