CN105834363B - A kind of low pressure loses the close casting system of cerotin - Google Patents
A kind of low pressure loses the close casting system of cerotin Download PDFInfo
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- CN105834363B CN105834363B CN201610385636.1A CN201610385636A CN105834363B CN 105834363 B CN105834363 B CN 105834363B CN 201610385636 A CN201610385636 A CN 201610385636A CN 105834363 B CN105834363 B CN 105834363B
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- shell
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/02—Sand moulds or like moulds for shaped castings
- B22C9/04—Use of lost patterns
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/08—Features with respect to supply of molten metal, e.g. ingates, circular gates, skim gates
- B22C9/082—Sprues, pouring cups
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D18/00—Pressure casting; Vacuum casting
- B22D18/04—Low pressure casting, i.e. making use of pressures up to a few bars to fill the mould
Abstract
The invention discloses a kind of low pressure to lose the close casting system of cerotin, including the holding furnace being located in air injection machine, stalk is inserted in holding furnace, holding furnace is stretched out at the top of stalk and in the centre bore of low pressure casting machine worktable, low pressure casting machine worktable is fixedly arranged above lifting steel plate, lifting steel plate is fixedly arranged above moulding steel plate, moulding steel plate is fixedly arranged above sandbox, sandbox top is covered with compression steel plate, it compresses and is pressed with pressing device above steel plate, the lumen centers of sandbox are equipped with combination shell, combination shell and stalk coaxial line；Combination shell includes the thin-wall product shell, ingate shell, cross gate shell and the sprue cup shell that penetrate through successively from top to bottom, and the lower port of sprue cup shell is located in the centre bore of moulding steel plate and is docked with the upper port sealing of stalk；It combines the periphery of shell and the inner space of thin-wall product shell is filled with dry sand.The system can at high temperature be molded thin-wall product, at low cost, efficient, and defect is few.
Description
Technical field
The present invention relates to a kind of casting system, more particularly to a kind of low pressure loses the close casting system of cerotin, belongs to metal casting
Technical field.
Background technology
Model casting is also known as lost-wax casting, and the production process of lost-wax casting is to coat several layers of refractory material in wax pattern surface,
After its dry through, wax-pattern therein is melted and shell is made, shaped, then poured into a mould, after cooling using roasting
Obtain casting.Since the casting of acquisition has higher dimensional accuracy and surface smoothness, therefore also known as precision-investment casting.
Low pressure casting is that liquid metal is made to fill cavity under pressure, to form a kind of method of casting.Low pressure is cast
The technical process made is as follows：It is passed through dry compressed air in closed holding furnace, the molten metal in holding furnace is in gas pressure
Rise under power along stalk, cavity is entered by cast gate, keep the pressure of heat preservation furnace gas until the molten metal in cavity is complete
Full solidification forms casting.Then heat preservation furnace pressure is released, not solidified molten metal in stalk is made to flow back to holding furnace, then is released
Pressing device pressure at the top of casting mold takes out casting.
Fired mold precision casting type shell is manually poured into a mould under gravity state under normal circumstances, but for complicated, wall
The larger casting of thick great disparity pours into a mould obtained product under gravity state, and often internal flaw is more, and mechanical property is not up to standard,
And it solves the problems, such as this effective method and exactly precision investment casting mould case is placed on low-pressure die casting plant under low voltage situations
Cast.Because liquid metal filling is steady during low pressure casting, the defects of can reducing oxide slag inclusion, casting solidifies under stress, so
Dense structure's high mechanical properties.
When casting fine casting shell using the method for low pressure casting, first have to solve the interface between shell and air injection machine
Problem realizes that this technique mainly has following two modes at present：
1st, special tooling is made, frock is directly born against on shell, is mechanically fastened.The method limitation
It is larger, it needs to make different frocks for different casting, it is necessary to expend substantial amounts of cost；Fastening between frock and shell
The bad grasp of power, fastening force is too small to cause shell leakage, and casting is caused to scrap or even to the personal safety of operating personnel and set
Standby safety damages, and fastening force can then damage shell very much greatly.
2nd, with phenolic sand molding, shell is placed in sandbox and then is coated shell completely with resin sand, then will made
Sandbox is placed in low-pressure casting machine workbench and poured into a mould, the method similar to sand mold low pressure casting, compared with making frock
Method security is well very much.But this method has the disadvantage that：(1) the shell of investment pattern precision casting is in shell under normal circumstances
Itself have and pour into a mould in the state of higher temperature, so ensure that thin-wall shell fills type.And if using resin sand by type
Shell cladding carries out low-pressure casting, and shell must be just that room ambient conditions could carry out, and so, investment pattern precision casting can be forming thin-walled
The advantage of part is just obliterated.(2) the technique needs to consume substantial amounts of resin sand, and resin sand price costly, is added and is produced into
This.(3) resin sand curing needs longer time, influences production efficiency.(4) resin can be heated when aluminium alloy passes through resin sand,
Generate a large amount of gases, gas, which enters after cavity, some and have little time to discharge into casting, causes to form gas in casting
Hole defect.(5) nearby resin sand easily makes resin depleted defeated and dispersed so as to cause molding sand to cast gate by prolonged baking, bursts
Molding sand after dissipating can enter low-pressure casting thermal insulation furnace by stalk, and molding sand can be into pouring into a mould behind in stove when pouring into a mould again
Cast-internal, in casting the defects of generation sand holes.
The content of the invention
It is an object of the present invention to overcome problems of the prior art, a kind of low pressure is provided and loses wax hot investment casting system
System, can at high temperature be molded thin-wall product, without resin sand, the defects of reducing stomata, sand holes, and production cost
Low, production efficiency is high.
For solution more than technical problem, a kind of low pressure of the invention loses the close casting system of cerotin, including being located at low pressure casting
Holding furnace in machine, the liquid Space of the holding furnace are inserted with stalk, and the gas-phase space side wall of the holding furnace passes through air inlet
Valve is connected with compressed air hose, and the holding furnace is stretched out and positioned at the workbench of the air injection machine in the top of the stalk
In centre bore, the workbench of the air injection machine is fixedly arranged above lifting steel plate, and being fixedly arranged above for steel plate of lifting is made
Shape steel plate, the moulding steel plate are fixedly arranged above sandbox, and the top of the sandbox is covered with compression steel plate, the compression steel plate
Top is pressed with pressing device, and the lumen centers of the sandbox are equipped with combination shell, and the combination shell is coaxial with the stalk
Line；The combination shell includes the thin-wall product shell, ingate shell, cross gate shell and the cast gate that penetrate through successively from top to bottom
Cup type shell, the lower end of the sprue cup shell are located in the centre bore of the moulding steel plate and seal between the two, the cast gate
The lower port of cup type shell is docked with the upper port sealing of the stalk；The periphery of the combination shell and the thin-wall product type
The inner space of shell is filled with dry sand.
Compared with the prior art, the present invention achieves following advantageous effect：(1) moulding steel plate is added, it can be first by moulding
Steel plate is placed on smooth ground, will combination shell be placed in the centre bore of moulding steel plate and sprue cup shell downward；Due to
The centre bore of moulding steel plate is smaller, and the sealing and fixation being easy to implement between sprue cup shell pass through handling moulding steel plate
Easily sandbox and combination shell can be transferred on lifting steel plate.(2) sandbox is carried with moulding steel plate, may be employed dry
Sand is filled, and avoids, using expensive resin sand, considerably reducing production cost；Dry sand is convenient for inclining after casting complete
, and resin sand intensity is very high needs mechanical oscillation that could clear up；And dry sand will not generate gas while shell is combined in protection
Body avoids and gas intrusion casting formation gas hole defect is generated after resin sand is heated.If without using moulding steel plate directly with tree
Fat sand molding can cause with the resin sand near stalk nozzle the combustion decomposition when the high temperature, and sand becomes loose after efficiency lost resin
State, casting complete hang away sandbox, and loose sand can enter from stalk in holding furnace because of the carrying of no steel plate,
When pouring into a mould next product, sand can cause defect into product.(3) sandbox is subject to the pressure of pressing device, and combination shell is done
The pressure of sand, stalk rises with holding furnace generates lift, the sealing between sprue cup shell lower port and stalk upper port
Part is compacted, and ensures sealing effect.(4) compressed gas is passed through to the gas-phase space of holding furnace, the molten metal edge for keeping the temperature furnace bottom rises
Liquid pipe rise, from the lower port of sprue cup shell enter combination shell cavity in, and from top to bottom successively by sprue cup shell,
The cavity of cross gate shell, ingate shell and thin-wall product shell is full of, and then the molten metal in thin-wall product cavity is being pressed
It is solidified under power；Then deflate to the gas-phase space of holding furnace, the gauge pressure in holding furnace is made to be rapidly reduced to 0MPa, stalk
And its non-frozen metal liquid stream of top is returned in holding furnace；Then remove pressing device and compress steel plate, will lifting steel plate together with
Moulding steel plate and sandbox Integral lifting thereon to knockout region carries out knockout, and redundance is cut after knockout and obtains thin-walled production
Product.(5) precision-investment casting, the group that the present invention passes through moulding steel plate and lifting steel plate are carried out for complicated thin-wall product
Conjunction realizes the lower port of sprue cup shell and the sealing of the upper port of stalk is docked, so as to not change stalk top dead-centre
Low pressure casting is realized in the case of height, compared with gravity-assist pouring, the defects of reducing oxide slag inclusion, casting coagulates under stress
Admittedly so that dense structure's high mechanical properties.(6) for the present invention when carrying out low-pressure casting, combination shell has higher high temperature in itself,
Dry sand plays insulation effect to combination shell, and be conducive to thin-wall product fills type；And traditional low-pressure casting carries out at normal temperatures
Cast, influences the shaping of thin-wall part.
As the present invention improvement, the sprue cup shell be up-small and down-big horn mouth, the sprue cup shell it is upper
Port is connected and is mutually communicated with the center of cross gate shell, and each end of the cross gate shell is horizontally outward symmetrically prolonged
It stretches, is connected and is mutually communicated with the lower port of the ingate shell respectively above each end of the cross gate shell, each institute
The upper port for stating ingate shell is connected and is mutually communicated with the lower face of the thin-wall product shell respectively.Molten metal is from a liter liquid
Pipe, which rises, initially enters the cavity of sprue cup, is upwardly into the center of cross gate cavity from sprue cup cavity, then along each cross gate
Horizontal symmetrical flows out, and is upwardly into thin-wall product cavity from each ingate, ensure that thin-wall product is uniform in entire circumferential direction
And synchronously fill type.
As a further improvement on the present invention, the lower, outer perimeter of the sprue cup shell and the centre bore of the moulding steel plate
Filled with asbestos cord between inner wall, the upper periphery of the sprue cup shell covered with asbestos pad, wrap by the periphery of the asbestos pad
Muff is covered with, the muff is surrounded and is spliced by symmetrical two halves.Asbestos cord realizes sprue cup shell lower part
Sealing and positioning between moulding steel plate centre bore, prevent dry sand from being leaked out from gap between the two, and asbestos cord is led
Hot coefficient is low, plays the role of heat preservation；Sprue cup shell top sets asbestos pad and muff that can prevent sprue cup shell
Heat scatters and disappears, and the molten metal in sprue cup is avoided to solidify, it is ensured that after the casting shaping in thin-wall product cavity, the gold in sprue cup
Belong to liquid energy and enough flow back to holding furnace, to save the consumption of molten metal.
As a further improvement on the present invention, the muff is covered over clay-bonded sand, the top of the clay-bonded sand
The lower section of the cross gate shell is filled in, the underfill of the clay-bonded sand is in the top of the moulding steel plate, the clay
The periphery of sand is filled with the dry sand.The adhesive property of clay-bonded sand is good, and intensity is high, can improve the stability of combination shell, will
Dry sand is separated with asbestos cord, it is ensured that dry sand will not leak into holding furnace from the gap of moulding steel plate centre bore, pollute molten metal.
As a further improvement on the present invention, the runner internal diameter of the stalk is more than the lower port of the sprue cup shell
Internal diameter, the top of the stalk are equipped with discoid stalk flange, and the stalk flange is located at the air injection machine
Table core hole in；Flange collar protruding upward is equipped in the middle part of the top surface of the stalk flange, the flange collar is located at described
In the centre bore for lifting steel plate, the inner circumferential of the flange collar forms step in flange, and the periphery of the flange collar forms flange outer step,
Step is higher than the flange outer step in the flange, is equipped between the lower face of step and the moulding steel plate in the flange
External seal pad is equipped between the lower face of interior sealing pad, the flange outer step and the lifting steel plate.Interior sealing pad realizes
Sealing in flange between step and moulding steel plate, external seal pad realize flange outer step and lift the sealing between steel plate,
Thoroughly prevent the leakage of molten metal by inside and outside two seals.Simultaneously because moulding steel plate is additionally arranged, the top dead-centre position of stalk
It is identical when putting with pouring into a mould other sand casting products, stalk height need not be adjusted back and forth, reduce human operational error or frequency
The molten metal risk of leakage that the mechanical breakdown that numerous mechanical action causes is triggered avoids occurring to cause great people because of molten metal leakage
Body equipment breakdown.
As a further improvement on the present invention, the lower face of the lifting steel plate is connected with four lifting steel plate positioning columns,
The lower end of each lifting steel plate positioning column is inserted into respectively in the locating slot of the low pressure casting machine worktable；The moulding steel plate
Lower face be connected with four moulding steel plate positioning pins, the lifting steel is inserted into the lower end of each moulding steel plate positioning pin respectively
In the location hole of plate.Moulding steel plate positioning pin can realize moulding steel plate and lift the accurate positionin between steel plate, lift steel plate
Positioning column can realize the accurate positionin between lifting steel plate and low pressure casting machine worktable, it can be ensured that air injection machine works
Platform, stalk with combining coaxial line between shell, and while lifting calibrate it is efficient and convenient.
As a further improvement on the present invention, it is uniformly provided with breathable microporous in the upper portion side wall of the thin-wall product shell.
Molten metal along cavity be gradually increasing when, the gas above cavity can be discharged by breathable microporous in dry sand, prevent production in cavity
Raw feel suffocated causes casting the defects of stomata and misrun occur.
As a further improvement on the present invention, the top surface outer rim of the lifting steel plate is arranged with lifting steel plate hanging ring, institute
The top surface outer rim for stating moulding steel plate is arranged with moulding steel plate hanging ring.Moulding steel can smoothly be lifted by crane by moulding steel plate hanging ring
Plate can smoothly play lifting steel plate by lifting steel plate hanging ring.
As a further improvement on the present invention, the combination shell is fabricated as follows successively：(1) combination is made
Wax-pattern, the combination wax-pattern include sequentially connected thin-wall product wax-pattern, ingate wax-pattern, cross gate wax-pattern from top to bottom and pour
Cup wax-pattern, the sprue cup wax-pattern are up-small and down-big cone, the upper end of the sprue cup wax-pattern and cross gate wax-pattern
Center is connected, and each end of the cross gate wax-pattern is horizontally outward symmetrically extended, above each end of the cross gate wax-pattern
The lower end with the ingate wax-pattern is connected respectively, the upper port of each ingate wax-pattern respectively with the thin-wall product wax-pattern
Lower face connection；(2) in combination wax pattern surface uniform fold investment precoat, one layer of white fused alumina of uniform fold on investment precoat
Sand makes combination wax pattern surface dry to form surface shell when then storage 5.5~6.5 is small indoors；(3) surface shell table is blown away
After the extra sand grains in face, in surface shell surface uniform fold first layer backing layer coating, uniformly covered on first layer backing layer coating
Lid first layer backing layer sand forms second layer shell after drying when storage 10~12 is small indoors；(4) second layer shell surface is blown away
Extra sand grains after, in second layer shell surface uniform fold second layer backing layer coating, uniformly covered on second layer backing layer coating
Lid second layer backing layer sand forms third layer shell after drying when storage 10~12 is small indoors；(5) third layer shell surface is blown away
Extra sand grains after, in third layer shell surface uniform fold third layer backing layer coating, uniformly covered on third layer backing layer coating
Lid third layer backing layer sand forms the 4th stratotype shell after drying when storage 10~12 is small indoors；(6) it is (5) same square according to step
Method continues to sequentially form the five, the six stratotype shells in combination wax-pattern periphery；(7) after the extra sand grains for blowing away layer 6 shell surface,
Layer 6 shell surface uniform fold layer 6 backing layer coating forms layer 7 type after drying when storage 10~12 is small indoors
Shell；(8) the above-mentioned combination wax-pattern for being coated with shell is placed in high steam dewaxing kettle, combination wax-pattern is made to melt stream at high temperature
Go out, obtain the combination shell of cavity；(9) the combination shell for having taken off wax is put into roaster, with 1050 ± 10 DEG C of high-temperature roasting
1~1.2 it is small when, be subsequently cooled to 500 ± 10 DEG C.The present invention forms surface shell, structure using investment precoat and white fused alumina sand
Densification, coefficient of thermal expansion is small and uniform, chemical stability is good, and inner wall smooth, makes the casting of acquisition have higher size essence
Degree and surface smoothness；By successively coating backing layer coating and covering backing layer sand outside surface shell, progressively enhance the strong of shell
Degree and rigidity avoid the compressive deformation in cast or crack, and outermost layer coating backing layer coating makes outer surface be avoided without sand grains
Sand grains at shell lower port comes off, and falls into and slag inclusion is caused in stalk.
As a further improvement on the present invention, the raw material components of the investment precoat and weight ratio are Ludox：Brown Alundum
Powder=1:（2.8~3.2）, described first to layer 6 backing layer coating raw material components and weight ratio are Ludox：Upper shop powder=1:
（1.6~1.8）, the silica of 25~30wt% is contained in the Ludox, the brown alundum powder and the upper shop powder are 300
~325 mesh；The white fused alumina sand is 70~120 mesh, in the first layer backing layer sand on 70~120 mesh containing 80wt% shop sand and
70~120 mesh graphite sands of 20wt%, in the second layer backing layer sand on 30~60 mesh containing 80wt% shop sand and 20wt% 30~
60 mesh graphite sands, 16~30 mesh of shop sand and 20wt% on 16~30 mesh containing 80wt% in third and fourth and five layers of backing layer sand
Graphite sand.The performance of Ludox is stable, manufactured investment shell intensity is higher, can voluntarily curing operation it is convenient；The structure of white fused alumina sand
Densification, coefficient of thermal expansion is small and uniform, chemical stability is good；The coefficient of thermal expansion of brown alundum powder is small and uniform, chemical stability
Well, refractoriness is high, the cavity interior wall construction densification for the investment precoat formation that brown alundum powder is formed with Ludox allotment, thermal expansion system
Number is small and uniform, chemical stability is good and smooth.The raw material sources of upper shop Fen Heshang shops sand are wide, cheap, refractoriness is high,
Linear expansion coefficient is small, thermal stability and chemical stability are high, and the upper shop sand and graphite sand used closer to inner layer is thinner, is conducive to
Improve the surface smoothness of casting.The present invention adds the graphite sand of 20wt% in backing layer sand, and obtained shell is in high-temperature roasting
In the process, countless tiny scattered holes are left after a part of graphite burning in shell section, these holes substantially increase type
The gas permeability of shell, reduce due to shell gas permeability is insufficient casting is caused to be felt suffocated, the probability of misrun.
Description of the drawings
The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, attached drawing only provide with reference to
Illustrate to use, it is non-limiting the present invention.
Fig. 1 is the structure diagram that low pressure of the present invention loses the close casting system of cerotin.
Fig. 2 is the enlarged drawing at A positions in Fig. 1.
Fig. 3 is the structure diagram of combination shell.
Fig. 4 is the stereogram before muff surrounds.
Fig. 5 is the stereogram after muff surrounds.
Fig. 6 is the front view of stalk.
Fig. 7 is the installation diagram at stalk flange position.
Fig. 8 is the front view of sprue cup wax-pattern and cross gate wax-pattern.
Fig. 9 is the top view of Fig. 8.
Figure 10 is along the sectional view of B-B in Fig. 8.
Figure 11 is the schematic diagram that cross gate plug is covered in Figure 10.
Figure 12 is the three-dimensional exploded view of sprue cup wax-pattern and cross gate wax-pattern.
Figure 13 is the product after present invention casting processing.
In figure：1. air injection machine；1a. low pressure casting machine worktables；2. holding furnace；V1. intake valve；3. stalk；3a.
Stalk flange；3b. flange collars；4. interior sealing pad；5. external seal pad；6. lift steel plate；6a. lifts steel plate positioning column；6b. is lifted
Steel plate hanging ring；7. moulding steel plate；7a. moulding steel plate positioning pins；7b. moulding steel plate hanging rings；8. combine shell；8a. thin-wall products
Shell；8b. ingate shells；8c. cross gate shells；8d. sprue cup shells；8e. breathable microporous；9. sandbox；9a. clay-bonded sands；
9b. dry sands；10. compress steel plate；11. asbestos cord；12. asbestos pad；13. muff；13a. lock ears；14. sprue cup wax-pattern；15.
Cross gate wax-pattern；15a. cross gate plugs；16. thin-wall product.
Specific embodiment
As shown in Figure 1 to Figure 3, low pressure of the invention, which loses the close casting system of cerotin, includes the guarantor being located in air injection machine 1
Warm stove 2, the liquid Space of holding furnace 2 are inserted with stalk 3, and the gas-phase space side wall of holding furnace 2 is empty with compression by intake valve V1
Tracheae connects, and holding furnace 2 is stretched out and in the centre bore of low pressure casting machine worktable 1a in the top of stalk 3, low pressure casting
The workbench of machine is fixedly arranged above lifting steel plate 6, and lifting steel plate 6 is fixedly arranged above moulding steel plate 7, the top of moulding steel plate 7
Be fixed with sandbox 9, the top of sandbox 9 compresses 10 top of steel plate and is pressed with pressing device covered with steel plate 10 is compressed, sandbox 9 it is interior
Chamber center is equipped with combination shell 8, combination shell 8 and 3 coaxial line of stalk；Combination shell 8 includes what is penetrated through successively from top to bottom
Thin-wall product shell 8a, ingate shell 8b, cross gate shell 8c and sprue cup shell 8d, the lower end of sprue cup shell 8d are located at
It seals in the centre bore of moulding steel plate 7 and between the two, the lower port of sprue cup shell 8d and the upper port sealing pair of stalk 3
It connects；It combines the periphery of shell 8 and the inner space of thin-wall product shell 8a is filled with dry sand 9b.
Sprue cup shell 8d is up-small and down-big horn mouth, the upper port of sprue cup shell 8d in cross gate shell 8c
The heart is connected and is mutually communicated, and each end of cross gate shell 8c is horizontally outward symmetrically extended, each end of cross gate shell 8c
Top is connected and is mutually communicated with the lower port of ingate shell 8b respectively, the upper port of each ingate shell 8b respectively with thin-walled
The lower face of product shell 8a connects and is mutually communicated.
Asbestos cord 11 is filled between the lower, outer perimeter of sprue cup shell 8d and the center bore inner wall of moulding steel plate 7.Cast gate
The upper periphery of cup type shell 8d is coated with muff 13 covered with asbestos pad 12, the periphery of asbestos pad 12.
As shown in Figure 4, Figure 5, muff 13 is surrounded and is spliced by symmetrical two halves, and asbestos pad 12 is wrapped in and is poured
Behind the periphery of cup shell 8d, muff 13 is stuck in the outside of asbestos pad 12 in opposite directions, bolt passes through lock ear 13a by the Kazakhstan of both sides
Husband connects.
The lower section for being covered over clay-bonded sand 9a, cross gate shell 8c being filled at the top of clay-bonded sand 9a of muff 13,
The underfill of clay-bonded sand 9a is filled with dry sand 9b in the top of moulding steel plate 7, the periphery of clay-bonded sand 9a.
As shown in Figure 6, Figure 7, the runner internal diameter of stalk 3 is more than the lower port internal diameter of sprue cup shell 8d, stalk 3
Top is equipped with discoid stalk flange 3a, and stalk flange 3a is located in the table core hole of air injection machine；Rise liquid
Flange collar 3b protruding upward is equipped in the middle part of the top surface of pipe flange 3a, flange collar 3b is located in the centre bore of lifting steel plate 6, flange collar 3b's
Inner circumferential forms step in flange, and the periphery of flange collar 3b forms flange outer step, and step is higher than flange outer step in flange, in flange
Interior sealing pad 4 is equipped between the lower face of step and moulding steel plate 7, is set between flange outer step and the lower face for lifting steel plate 6
There is external seal pad 5.Interior sealing pad 4 realizes the sealing between step and moulding steel plate 7 in flange, and external seal pad 5 realizes method
Sealing between blue outer step and lifting steel plate 6, thoroughly prevents the leakage of molten metal by inside and outside two seals.
The lower face of lifting steel plate 6 is connected with four lifting steel plate positioning column 6a, each lower end for lifting steel plate positioning column 6a
It is inserted into respectively in the locating slot of low pressure casting machine worktable 1a；The lower face of moulding steel plate 7 is connected with four moulding steel plate positioning
7a is sold, the lower end of each moulding steel plate positioning pin 7a is inserted into respectively in the location hole of lifting steel plate 6.Moulding steel plate positioning pin 7a can be with
Realize the accurate positionin between moulding steel plate 7 and lifting steel plate 6, lifting steel plate positioning column 6a can realize lifting steel plate 6 with it is low
Accurate positionin between pressure casting machine workbench 1a, it can be ensured that low pressure casting machine worktable 1a, stalk 3 are with combining shell 8
Between coaxial line, and lift when calibrate it is efficient and convenient.
Breathable microporous 8e is uniformly provided in the upper portion side wall of thin-wall product shell 8a.Molten metal along cavity be gradually increasing when,
Gas above cavity can be discharged into dry sand 9b by breathable microporous 8e, prevent from generating to feel suffocated in cavity that casting is caused gas occur
The defects of hole and misrun.
The top surface outer rim of lifting steel plate 6 is arranged with lifting steel plate hanging ring 6b, and the top surface outer rim of moulding steel plate 7 is arranged with
Moulding steel plate hanging ring 7b.
Combination shell 8 is fabricated as follows successively：Make combination wax-pattern, combination wax-pattern include from top to bottom according to
Thin-wall product wax-pattern, ingate wax-pattern, cross gate wax-pattern and the sprue cup wax-pattern of secondary connection, sprue cup wax-pattern 14 are up-small and down-big
Cone, the upper end of sprue cup wax-pattern 14 is connected with the center of cross gate wax-pattern 15, each end water of cross gate wax-pattern 15
Flat to be outwards symmetrically extended, the lower end above each end of cross gate wax-pattern 15 respectively with ingate wax-pattern is connected, each ingate wax
Lower face of the upper port of mould respectively with thin-wall product wax-pattern is connected.As shown in Fig. 8 to Figure 12, sprue cup wax-pattern 14 is hollow
Cone tube shape, cross gate wax-pattern 15 are hollow rectangular section, and each end point of cross gate wax-pattern 15 is covered with cross gate plug
15a is simultaneously welded seam crossing completely with electric iron.Cross gate plug 15a is suppressed with small plug mold, cross gate plug
The inner face of 15a is equipped with plug step, and plug step is respectively embedded into the port of cross gate wax-pattern 15, cross gate plug 15a
Outer rim it is concordant with the outer rim of cross gate wax-pattern 15.(2) wax pattern surface uniform fold investment precoat is being combined, on investment precoat
One layer of white fused alumina sand of uniform fold makes combination wax pattern surface dry forming face stratotype when then storage 5.5~6.5 is small indoors
Shell.(3) after blowing away the extra sand grains on surface shell surface, in surface shell surface uniform fold first layer backing layer coating, first
Uniform fold first layer backing layer sand on layer backing layer coating, forms second layer shell after drying when storage 10~12 is small indoors.⑷
After the extra sand grains for blowing away second layer shell surface, in second layer shell surface uniform fold second layer backing layer coating, second
Uniform fold second layer backing layer sand on layer backing layer coating, forms third layer shell after drying when storage 10~12 is small indoors.⑸
After the extra sand grains for blowing away third layer shell surface, in third layer shell surface uniform fold third layer backing layer coating, the 3rd
Uniform fold third layer backing layer sand on layer backing layer coating, forms the 4th stratotype shell after drying when storage 10~12 is small indoors.⑹
According to step, (5) same method continues to sequentially form the five, the six stratotype shells in combination wax-pattern periphery.(7) layer 6 shell is blown away
After the extra sand grains on surface, in layer 6 shell surface uniform fold layer 6 backing layer coating, store indoors 10~12 it is small when
Layer 7 shell is formed after drying；(8) the above-mentioned combination wax-pattern for being coated with shell is placed in high steam dewaxing kettle, makes combination
Wax-pattern is melted out at high temperature, obtains the combination shell of cavity；(9) the combination shell for having taken off wax is put into roaster, used
When 1050 ± 10 DEG C of high-temperature roasting 1~1.2 is small, 500 ± 10 DEG C are subsequently cooled to.
The raw material components and weight ratio of investment precoat are Ludox：Brown alundum powder=1:（2.8~3.2）, first to layer 6
The raw material components and weight ratio of backing layer coating are Ludox：Upper shop powder=1:（1.6~1.8）, containing 25~30wt% in Ludox
Silica, brown alundum powder and upper shop powder are 300~325 mesh；White fused alumina sand is 70~120 mesh, is contained in first layer backing layer sand
70~120 mesh graphite sands of shop sand and 20wt% on 70~120 mesh of 80wt%, in second layer backing layer sand containing 80wt% 30~60
30~60 mesh graphite sands of shop sand and 20wt% on mesh, shop sand on 16~30 mesh containing 80wt% in third and fourth and five layers of backing layer sand
With 16~30 mesh graphite sands of 20wt%.It is left in high-temperature calcination process, after a part of graphite burning in shell section countless thin
Small scattered hole, these holes substantially increase the gas permeability of shell.
The course of work that low pressure of the present invention loses the close casting system of cerotin in turn includes the following steps：(1) moulding steel plate 7 is put
It puts on smooth ground, sandbox 9 is placed on moulding steel plate 7, combination shell 8 is placed in the centre bore of moulding steel plate 7, group
The sprue cup shell 8d of mould assembly shell 8 is downward and centre bore coaxial line with moulding steel plate 7 of combination shell 8, sandbox 9；(2) stone is used
Cotton cord 11 fills in the gap between the lower, outer perimeter of sprue cup shell 8d and moulding steel plate center bore inner wall in fact, then in cast gate cup type
The upper periphery of shell 8d tamps fixation using clay-bonded sand 9a, and the lower section of cross gate shell 8c is filled at the top of clay-bonded sand 9a, glues
The bottom of soil sand 9a is against the top of moulding steel plate 7；(3) sandbox 9 is filled up using dry sand 9b, it is the periphery of clay-bonded sand 9a, combined
The periphery of shell 8 and the inner space of thin-wall product shell 8a are tamped by dry sand 9b, and with scraper plate by the dry sand at the top of sandbox 9
9b strikes off；(4) 7 integral hoisting of moulding steel plate is placed on lifting steel plate and is fixedly connected with the two, in moulding steel plate 7
Heart hole and the centre bore coaxial line of lifting steel plate；(5) lifting steel plate is hung simultaneously together with moulding steel plate 7 thereon and sandbox 9 are whole
It is fixed on the workbench of air injection machine, compresses steel plate 10 in 9 top covering of sandbox, compression steel plate is pressed in using pressing device
On 10；(6) holding furnace is advanced into operating position makes the stalk 3 of holding furnace pass through hydraulic lifting with combining 8 coaxial line of shell
Device rises holding furnace, until the upper port of stalk 3 is docked with the lower port of sprue cup shell 8d and realized between the two
Sealing；(7) compressed gas is passed through to the gas-phase space of holding furnace, the molten metal for keeping the temperature furnace bottom rises along stalk 3, from cast gate
The lower port of cup type shell 8d enters in the cavity of combination shell 8, and from top to bottom successively by sprue cup shell 8d, cross gate shell
The cavity of 8c, ingate shell 8b and thin-wall product shell 8a are full of, and then the molten metal in thin-wall product cavity is under stress
Solidification；(8) deflate to the gas-phase space of holding furnace, the gauge pressure in holding furnace made to be rapidly reduced to 0MPa, stalk 3 and its
The non-frozen metal liquid stream of top is returned in holding furnace；Then remove pressing device and compress steel plate 10, by lifting steel plate together with it
On moulding steel plate 7 and 9 Integral lifting of sandbox to knockout region carry out knockout.Redundance is cut after knockout and obtains thin-walled production
Product 16, as shown in figure 13.
Step (7) in, the pressure of holding furnace gas-phase space undergoes type stage of filling, crust stage, pressurization stages and pressurize successively
Stage fills the rate of pressurization in type stage for 1.5~2.0Kp/s, and filling type, the pressurize 5s in the case where filling type maximum pressure is delayed after finishing
Crust is punched into, maximum pressure is then pressurized to rapidly with the speed of 3.0~5.0 Kp/s, maximum pressure should type is maximum to press than filling
Power is higher by 10 more than Kp；Pressurize makes casting solidification in 9~12 minutes under maximum pressure.
The foregoing is merely the preferable possible embodiments of the present invention, non-therefore the limitation present invention patent protection model
It encloses.In addition to the implementation, the present invention can also have other embodiment.All skills formed using equivalent substitution or equivalent transformation
Art scheme, all fall within the present invention claims protection domain in.
Claims (9)
1. a kind of low pressure loses the close casting system of cerotin, including the holding furnace being located in air injection machine, the liquid phase of the holding furnace
Space is inserted with stalk, and the gas-phase space side wall of the holding furnace is connected by intake valve with compressed air hose, the stalk
Top stretch out the holding furnace and in the table core hole of the air injection machine, it is characterized in that：The low pressure casting
The workbench for making machine is fixedly arranged above lifting steel plate, and the lifting steel plate is fixedly arranged above moulding steel plate, the moulding steel plate
Be fixedly arranged above sandbox, the top of the sandbox is pressed with pressing device, institute covered with steel plate is compressed above the compression steel plate
The lumen centers for stating sandbox are equipped with combination shell, the combination shell and the stalk coaxial line；The combination shell includes
Thin-wall product shell, ingate shell, cross gate shell and the sprue cup shell penetrated through successively from top to bottom, the cast gate cup type
The lower end of shell is located in the centre bore of the moulding steel plate and seals between the two, the lower port of the sprue cup shell with it is described
The upper port sealing docking of stalk；The periphery of the combination shell and the inner space of the thin-wall product shell are filled with dry
Sand；The runner internal diameter of the stalk is more than the lower port internal diameter of the sprue cup shell, and the top of the stalk is equipped with circle
The stalk flange of plate-like, the stalk flange are located in the table core hole of the air injection machine；The stalk
Flange collar protruding upward is equipped in the middle part of the top surface of flange, the flange collar is located in the centre bore of the lifting steel plate, the flange collar
Inner circumferential form step in flange, the periphery of the flange collar forms flange outer step, and step is higher than the flange in the flange
Outer step, is equipped with interior sealing pad in the flange between the lower face of step and the moulding steel plate, the flange outer step with
External seal pad is equipped between the lower face of the lifting steel plate.
2. low pressure according to claim 1 loses the close casting system of cerotin, it is characterized in that, the sprue cup shell for it is upper it is small under
Big horn mouth, the upper port of the sprue cup shell are connected and are mutually communicated with the center of cross gate shell, described horizontal to pour
Each end of road shell is horizontally outward symmetrically extended, above each end of the cross gate shell respectively with the ingate shell
Lower port connect and be mutually communicated, the upper port of each ingate shell lower face with the thin-wall product shell respectively
It connects and is mutually communicated.
3. low pressure according to claim 1 loses the close casting system of cerotin, it is characterized in that, outside the lower part of the sprue cup shell
All that asbestos cord is filled between the center bore inner wall of the moulding steel plate, the upper periphery of the sprue cup shell is covered with stone
Cotton pad, the periphery of the asbestos pad are coated with muff, and the muff is surrounded and is spliced by symmetrical two halves.
4. low pressure according to claim 3 loses the close casting system of cerotin, it is characterized in that, the muff is covered over
Clay-bonded sand is filled in the lower section of the cross gate shell at the top of the clay-bonded sand, and the underfill of the clay-bonded sand is described
The top of moulding steel plate, the periphery of the clay-bonded sand are filled with the dry sand.
5. low pressure according to claim 1 loses the close casting system of cerotin, it is characterized in that, the lower face of the lifting steel plate connects
Four lifting steel plate positioning columns are connected to, the low pressure casting machine worktable is inserted into the lower end of each lifting steel plate positioning column respectively
Locating slot in；The lower face of the moulding steel plate is connected with four moulding steel plate positioning pins, each moulding steel plate positioning pin
Lower end be inserted into respectively it is described lifting steel plate location hole in.
6. low pressure according to claim 1 loses the close casting system of cerotin, it is characterized in that, the top of the thin-wall product shell
Breathable microporous is uniformly provided on side wall.
7. low pressure according to claim 1 loses the close casting system of cerotin, it is characterized in that, the top surface outer rim of the lifting steel plate
Lifting steel plate hanging ring is arranged with, the top surface outer rim of the moulding steel plate is arranged with moulding steel plate hanging ring.
8. low pressure according to claim 1 loses the close casting system of cerotin, it is characterized in that, the combination shell is successively by as follows
Step is fabricated：(1) combination wax-pattern is made, and the combination wax-pattern includes sequentially connected thin-wall product wax-pattern, interior from top to bottom
Cast gate wax-pattern, cross gate wax-pattern and sprue cup wax-pattern, the sprue cup wax-pattern be up-small and down-big cone, the sprue cup wax
The upper end of mould is connected with the center of cross gate wax-pattern, and each end of the cross gate wax-pattern is horizontally outward symmetrically extended, described
Lower end above each end of cross gate wax-pattern respectively with the ingate wax-pattern is connected, the upper port of each ingate wax-pattern
The lower face with the thin-wall product wax-pattern is connected respectively；(2), in combination wax pattern surface uniform fold investment precoat, applied in surface layer
One layer of white fused alumina sand of uniform fold on material makes combination wax pattern surface dry to form surface layer when then storage 5.5~6.5 is small indoors
Shell；(3) after blowing away the extra sand grains on surface shell surface, in surface shell surface uniform fold first layer backing layer coating,
Uniform fold first layer backing layer sand on one layer of backing layer coating forms second layer shell after drying when storage 10~12 is small indoors；
(4) after the extra sand grains for blowing away second layer shell surface, in second layer shell surface uniform fold second layer backing layer coating,
Uniform fold second layer backing layer sand on two layers of backing layer coating forms third layer shell after drying when storage 10~12 is small indoors；
(5) after the extra sand grains for blowing away third layer shell surface, in third layer shell surface uniform fold third layer backing layer coating,
Uniform fold third layer backing layer sand on three layers of backing layer coating forms the 4th stratotype shell after drying when storage 10~12 is small indoors；
(6) according to step, (5) same method continues to sequentially form the five, the six stratotype shells in combination wax-pattern periphery；(7) layer 6 type is blown away
After the extra sand grains on shell surface, in layer 6 shell surface uniform fold layer 6 backing layer coating, it is small that 10~12 are stored indoors
When drying after formed layer 7 shell；(8) the above-mentioned combination wax-pattern for being coated with shell is placed in high steam dewaxing kettle, makes group
It closes wax-pattern to be melted out at high temperature, obtains the combination shell of cavity；(9) the combination shell for having taken off wax is put into roaster, used
When 1050 ± 10 DEG C of high-temperature roasting 1~1.2 is small, 500 ± 10 DEG C are subsequently cooled to.
9. low pressure according to claim 8 loses the close casting system of cerotin, it is characterized in that, the raw material components of the investment precoat
And weight ratio is Ludox：Brown alundum powder=1:（2.8~3.2）, described first to layer 6 backing layer coating raw material components and again
Amount is than being Ludox：Upper shop powder=1:（1.6~1.8）, the silica of 25~30wt%, the Brown Alundum are contained in the Ludox
Powder and the upper shop powder are 300~325 mesh；The white fused alumina sand is 70~120 mesh, is contained in the first layer backing layer sand
70~120 mesh graphite sands of shop sand and 20wt% on 70~120 mesh of 80wt%, in the second layer backing layer sand containing 80wt% 30
30~60 mesh graphite sands of shop sand and 20wt% on~60 mesh, in third and fourth and five layers of backing layer sand containing 80wt% 16~30
16~30 mesh graphite sands of shop sand and 20wt% on mesh.
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| CN107855467B (en) * | 2017-11-22 | 2023-06-16 | 扬州峰明光电新材料有限公司 | Investment casting system and investment casting method for U-shaped magnesium alloy piece |
| CN108044082A (en) * | 2017-12-28 | 2018-05-18 | 安徽东升精密铸钢件有限公司 | A kind of low pressure casting die |
| CN108500209B (en) * | 2018-05-10 | 2020-02-25 | 河北钢研德凯科技有限公司 | Preparation method of high-collapsibility formwork |
| CN109332594B (en) * | 2018-11-20 | 2021-01-22 | 中国航发沈阳黎明航空发动机有限责任公司 | Connecting method of impurity clamping preventing pouring cup for large casting |
| CN110328351B (en) * | 2019-08-13 | 2021-06-04 | 西安西工大超晶科技发展有限责任公司 | Water glass sand-free molding process method for anti-gravity pouring investment casting |
| CN111001788B (en) * | 2019-12-25 | 2021-09-14 | 云南昆船机械制造有限公司 | Differential low-pressure pouring method for reinforcing by resin sand after core assembly |
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Address after: 225117 9, Feng Ming Road, Fang Xiang Industrial Park, Hanjiang District, Yangzhou, Jiangsu Patentee after: Yangzhou Feng Ming photoelectric New Material Co., Ltd. Address before: 225117 9, Feng Ming Road, Fang Xiang Industrial Park, Hanjiang District, Yangzhou, Jiangsu Patentee before: Yangzhou Feng Ming Metal Products Co., Ltd. |