Electromagnetic auxiliary pressurization aluminum alloy lost foam casting forming device and method

Abstract

The invention discloses an electromagnetic auxiliary pressurization aluminum alloy lost foam casting forming device and method.The device comprises an electromagnetic pressurization module and a lifting device module, a liftable electromagnetic coil is placed outside a sand box, during pouring, three-phase alternating current is supplied to the electromagnetic coil, a coil winding generates a traveling wave magnetic field, and the electromagnetic pressurization module is connected with the lifting device module; molten aluminum generates induced current under the action of a traveling wave magnetic field, the electrified molten aluminum cuts magnetic induction lines in the pouring process to generate downward constant magnetic field force, flowing of aluminum alloy melt micelles in a cavity is greatly promoted, mold filling power is improved, the pouring speed is increased, mold filling is complete, the structure is refined and compact, pouring defects are greatly reduced, and the mechanical property of a casting is improved. After pouring is completed, the electromagnetic pressurization module is lifted under the action of the lifting device module, the sand box is transferred to a sand shakeout area for next technological operation, and the working efficiency is improved; the invention further provides an electromagnetic auxiliary pressurizing aluminum alloy lost foam casting forming method so as to reduce the casting defects of aluminum alloy castings and improve the mechanical property of the castings.

Description

Technical Field

[0001] The invention relates to the field of aluminum alloy lost foam casting, and in particular to an electromagnetic assisted pressurized aluminum alloy lost foam casting forming device and method. Background Art

[0002] The lost foam casting technology is to foam EPS, ETMMA or EPMMA foam beads, combine the foam sheets into clusters by cutting and bonding, and make a model similar to the structure and size of the casting. Then, a layer of lost foam special coating is applied on the surface of the model by brushing, dipping, etc. After the coating is dried, the white mold is buried in dry sand. During the process of filling the dry sand, the dry sand needs to be vibrated by a vibration table to make it compact. The dry sand is filled as much as possible without damaging the white mold. Then, the molten metal is poured, the foam model is gasified, and the casting is obtained. After cooling, the sand is dropped, the casting is taken out, and finally the desired casting is obtained after polishing.

[0003] Lost foam castings have high dimensional accuracy, and because the model is made of foam plastics, the appearance and structure are not restricted by any restrictions, with high freedom, and can be used to manufacture extremely precise and complex components. Lost foam casting does not require box closing or demoulding, and also eliminates the steps of sand core and core making. Compared with traditional sand casting, the workload is greatly reduced and the production efficiency is greatly improved.

[0004] However, since a large amount of gas will be generated during the melting of the foam pattern, it will affect the pouring speed and direction of the aluminum liquid, and the pouring temperature of aluminum alloy castings is lower than that of steel castings. The heat of the molten metal consumed when melting the foam pattern has a more obvious cooling effect on the aluminum liquid, especially when large-sized complex thin-walled castings are poured under gravity. Due to insufficient filling power and too fast cooling of the aluminum liquid, it is easy to have casting defects such as insufficient pouring, cold shut, looseness, and pinholes, which make the castings not dense and the mechanical properties seriously reduced. The existing electromagnetic-assisted lost foam casting technology, see Chinese invention patent CN202310908175.1, mainly improves the performance of castings by applying electromagnetic stirring force, but because it cannot generate directional electromagnetic pressure to enhance the filling capacity of aluminum liquid, it is difficult to solve the casting defects caused by insufficient filling power and too fast cooling of aluminum liquid. In addition, the prior art does not design the casting module and the electromagnetic auxiliary module separately, and each sand box must be equipped with an independent electromagnetic auxiliary device, which not only increases resource consumption, but also complicates the sand dropping process, reduces production efficiency, and is difficult to meet the needs of industrial production. Summary of the invention

[0005] The purpose of the present invention is to provide an electromagnetically assisted pressurized aluminum alloy lost foam casting forming device and method to solve the problems that the prior art is difficult to solve, such as casting defects caused by insufficient filling power and rapid cooling of aluminum liquid, high resource consumption, complex procedures and low production efficiency.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An electromagnetic assisted pressurized aluminum alloy lost foam casting forming device, comprising: an electromagnetic pressurizing module and a lifting device module;

[0008] The electromagnetic boost module includes a yoke, a winding coil, an upper fixed sleeve, a lower fixed sleeve and a screw; four yokes are arranged around the square sand box; the yoke is made of silicon steel, and the yoke has six salient poles, and the coil windings are respectively wound on the six salient poles; the upper fixed sleeve and the lower fixed sleeve are respectively installed on the top and bottom of the yoke, and the upper fixed sleeve and the lower fixed sleeve are connected by a screw; a pull ring is provided on the upper fixed sleeve; the six winding coils on each yoke are divided into two groups, and the three winding coils in each group use a Y-type connection method, and three-phase alternating current is passed through, and the first, second, and third winding coils of the six winding coils from top to bottom are respectively connected with the fourth, fifth, and sixth winding coils in the same phase, and the corresponding first, second, third, fourth, fifth, and sixth winding coils on each yoke are connected in series to ensure the same phase;

[0009] The lifting device module includes two left and right parts symmetrically arranged on both sides of the electromagnetic booster module. The left and right parts are exactly the same and respectively include a column, a cantilever and an electric hoist; the column is provided with a cantilever, and the cantilever is provided with an electric hoist. The lower hook of the electric hoist is connected to the pull ring of the upper fixed sleeve. Under the action of the electric hoist, the electromagnetic booster module realizes the lifting function.

[0010] Furthermore, the width of the yoke is smaller than the width of the sand box, and the distance between the salient poles of the yoke is equal; two limit strips are welded around the upper fixed sleeve and the lower fixed sleeve, and the distance between the limit strips is the width of the yoke, which is used to limit the lateral movement of the yoke; bolt through holes are provided on the outside of the limit strips for bolt connection; feet are respectively provided at the four corners of the bottom of the lower fixed sleeve, and the height of the feet is greater than the height of the nut at the bottom of the screw.

[0011] Furthermore, in the lifting device module, a fixing plate is provided on the column, and the cantilever is connected to the fixing plate; eight reinforcing plates are provided at the bottom of the column, and the column is fixed to the ground by rivets; two limit blocks are provided on the upper part of the column, and the limit blocks are connected to the cantilever.

[0012] Furthermore, the cantilever adopts an I-shaped structure, and the electric hoist is fixed on the cantilever through a connecting pin.

[0013] Furthermore, the motors of the left and right electric hoists are connected in series to the same switch.

[0014] In a second aspect, the present invention provides an electromagnetic assisted pressurized aluminum alloy lost foam casting forming method implemented by the electromagnetic assisted pressurized aluminum alloy lost foam casting forming device described above, comprising the following steps:

[0015] Step 1: Use an intermittent steam pre-expander to pre-foam the EPS beads, put the pre-foamed beads into a maturation bin for maturation, preheat the mold to 70°C, inject the fully matured beads into the mold cavity with a material gun, introduce steam to foam the beads, and demold after cooling to obtain the white mold patterns of various parts of the casting; cut and glue the white molds that make up the casting, and then combine the casting white mold and the pouring system white mold into a cluster to obtain a complete pouring white mold pattern;

[0016] Step 2: coating the aluminum alloy lost foam casting coating on the surface of the white mold and then drying it;

[0017] Step 3: Put the painted white mold into the sand box, add dry sand into the sand box layer by layer, and vibrate the sand while adding it. Under the premise of ensuring that the mold does not deform, the dry sand in the sand box has a higher and more uniform filling density;

[0018] Step 4, degassing, deslagging, refining, refining and standing treatment of the aluminum solution;

[0019] Step 5: The sand box is transported from the compaction area to the pouring area via a conveyor belt. The electric hoist is turned on, and the lifting device module lowers the electromagnetic booster module. Three-phase alternating current is supplied to the winding coil to form a traveling wave magnetic field. The aluminum liquid begins to be poured. The aluminum liquid generates an induced current under the action of the traveling wave magnetic field. The charged aluminum liquid cuts the magnetic flux lines to obtain a downward electromagnetic driving force, melts the foam white mold, and forms a casting.

[0020] Step 6: Reverse the electric hoist, the lifting device module lifts the electromagnetic booster module, the sand box moves from the pouring area to the sand drop area via the conveyor belt, flips the sand box, pours the dry sand and castings from the sand box, cools the castings in water, vibrates and breaks or knocks the surface coating, and cleans the castings;

[0021] Step seven, subject the casting to T6 heat treatment, then machine to remove the pouring system, and finally obtain the desired casting after grinding, shot blasting and testing processes.

[0022] Furthermore, in step one, the maximum diameter of the EPS beads does not exceed 1 / 8 to 1 / 10 of the minimum wall thickness of the casting, and the bead density is selected to be 15 to 25 g / L; during pre-foaming, the pre-foaming machine pipeline pressure is controlled within 0.1 to 0.2 MPa, the expansion chamber pressure is controlled within 0.03 to 0.06 MPa, the pre-foaming temperature is controlled within 80 to 100°, the pre-foaming time is 2 to 5 minutes, and the aging time is controlled within 12 to 24 hours.

[0023] Furthermore, in step 2, the coating is mixed with diatomaceous earth, mullite, sodium bentonite, CMC, PVA, water glass, additives and water. When used, the dry powder coating and water are mixed in a preset ratio, first stirred at high speed for more than two hours, and then stirred at low speed for two hours; the prepared coating is evenly applied on the white mold, and then placed in the air to dry naturally for more than 24 hours, and the number of brushing times is twice. After the first brushing is completely dry, the second brushing is performed to ensure that the coating is completely dry before pouring.

[0024] Furthermore, in step three, the particle size of dry sand is 70-140 mesh. During the specific vibration, XYZ three-dimensional vibration is selected, the vibration frequency is 35-50 Hz, and the amplitude is 2 mm. When filling sand, the bottom sand filling height is first determined according to the height of the casting, and then the sand is filled layer by layer according to the structure of the casting, so that the dry sand height after each sand filling is at a structure that is difficult to fill with sand, and the difficult to fill with sand structure includes holes, interlayers, and corners.

[0025] Furthermore, in step 4, the melt purification process is to transfer the molten aluminum alloy into a refining furnace, add a refining agent twice at 730-750° C., and skim slag and fill with argon gas twice;

[0026] In step 5, a three-phase alternating current with a frequency of 30 to 60 Hz, a current of 40 to 80 A, and 40 to 80 turns of the coil is introduced;

[0027] In step seven, the alloy composition is A356 aluminum-silicon alloy, and the heat treatment process is: solution temperature is 535-540°C, solution time is 6-8h; quenching temperature is 60-80°C, quenching time is 2-3min; aging temperature is 160-190°C, aging time is 4-8h.

[0028] The present invention has the following beneficial effects:

[0029] The present invention proposes an electromagnetic assisted pressurized aluminum alloy lost foam casting forming device, wherein a liftable electromagnetic coil is placed outside a sand box, and during pouring, three-phase alternating current is passed through the electromagnetic coil, and the coil winding generates a traveling wave magnetic field. Under the action of the traveling wave magnetic field, the aluminum liquid generates an induced current, and the charged aluminum liquid cuts the magnetic flux lines during the pouring process to generate a downward constant magnetic field force, which greatly promotes the flow of aluminum alloy melt micro-clusters in the mold cavity, improves the filling power, accelerates the pouring speed, makes the filling complete, and makes the structure refined and dense, greatly reduces casting defects, and improves the mechanical properties of the casting.

[0030] The present invention proposes an electromagnetic assisted pressurized aluminum alloy lost foam casting forming device. After the casting is completed, the electromagnetic pressurization module is lifted up by the lifting device, and the sand box goes to the sand dropping area for the next process operation. When the next sand box comes to the pouring area, the coil is put down again for pouring, and so on. The operation difficulty is greatly reduced and the work efficiency is improved.

[0031] The present invention also provides a complete set of electromagnetic assisted pressurized aluminum alloy lost foam casting forming methods, which are applicable to most aluminum alloy castings, can greatly reduce the casting defects of aluminum alloy castings and improve the mechanical properties of castings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 This is a schematic structural diagram of an electromagnetic-assisted pressurized aluminum alloy lost foam casting forming device proposed by the present invention;

[0034] Figure 2 This is a structural schematic diagram of an electromagnetic boosting module in an electromagnetic assisted boosting aluminum alloy lost foam casting forming device proposed by the present invention;

[0035] Figure 3 This is a structural schematic diagram of a lifting device module in an electromagnetic-assisted pressurized aluminum alloy lost foam casting forming device proposed by the present invention.

[0036] Illustration: 1- yoke; 2- winding coil; 3- upper fixing sleeve; 4- lower fixing sleeve; 5- screw; 6- foot pad; 7- column; 8- limit block; 9- fixing plate; 10- cantilever; 11- connecting pin; 12- electric hoist. DETAILED DESCRIPTION

[0037] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the following detailed descriptions are all illustrative and are intended to provide an explanation in this embodiment of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those generally understood by those of ordinary skill in the art to which the present application belongs.

[0038] Reference Figure 1 to Figure 3 The embodiment of the present invention provides an electromagnetic assisted pressurized aluminum alloy lost foam casting forming device, including an electromagnetic pressurization module and a lifting device module. The electromagnetic pressurization module is composed of a yoke 1, a winding coil 2, an upper fixing sleeve 3, a lower fixing sleeve 4, a screw 5, and a foot 6; the lifting device module is composed of a left and a right part, and the left and right sides are completely the same, respectively composed of a column 7, a limit stopper 8, a fixing plate 9, a cantilever 10, a connecting pin 11, and an electric hoist 12.

[0039] In the electromagnetic boost module, four yokes 1 are arranged around the square sand box, and the upper fixing sleeve 3 and the lower fixing sleeve 4 are respectively installed on the top and bottom of the yoke 1. The upper fixing sleeve 3 and the lower fixing sleeve 4 are connected by bolts 5 to connect the four yokes 1 into a whole for lifting and lowering. The width of the yoke 1 should be smaller than the width of the sand box to ensure that there is space for the bolts to be installed.

[0040] In this embodiment, the yoke 1 is made of silicon steel, each yoke 1 has six salient poles, and the coil windings 2 are respectively wound on the six silicon steel salient poles. The distances between the salient poles are equal to ensure that the coil windings 2 between the salient poles will not interfere with each other. There should be enough distance between the first and sixth salient poles and the top and bottom of the yoke 1 to ensure that the upper and lower fixing sleeves 4 can be installed normally.

[0041] In this embodiment, the six winding coils 2 on each magnetic yoke 1 are divided into two groups, and the three winding coils 2 in each group are connected in a Y-type manner and are supplied with three-phase alternating current. The first, second, and third winding coils 2 from top to bottom of the six winding coils 2 should have the same phase as the fourth, fifth, and sixth winding coils 2 respectively when supplied with alternating current, and the corresponding first, second, third, fourth, fifth, and sixth winding coils 2 on each magnetic yoke 1 should be connected in series to ensure the same phase, thereby providing an efficient and stable traveling wave magnetic field.

[0042] In this embodiment, two limit bars are welded around the fixing sleeve 4, and the distance between the limit bars is the width of the yoke 1, so as to limit the lateral movement of the yoke 1; bolt through holes are provided on the outer side of the limit bars for bolt connection.

[0043] In this embodiment, two pull rings are welded on the top of the upper fixing sleeve 3, and the pull rings are connected to the hooks under the electric hoist 12 for easy lifting. The distance between the pull rings should be as large as possible to ensure the lifting stability of the electromagnetic booster module during the lifting process.

[0044] In this embodiment, the four corners of the bottom of the lower fixing sleeve are each connected to a rubber foot 6, which can prevent the lower fixing sleeve 4 from directly contacting the ground and reduce the loss of the lower fixing sleeve 4. The height of the foot 6 is greater than the height of the nut to facilitate the installation of the bolts and nuts.

[0045] In the lifting device module, a cantilever 10 is installed on the column 7. The fixed plate 9 on the column can both connect the cantilever 10 and limit the rotation of the cantilever 10. An electric hoist 12 is installed on the cantilever 10 through a connecting pin 11. The lower hooks of the two electric hoists 12 are connected to the pull ring of the upper fixed sleeve 4. Under the action of the electric hoist 12, the electromagnetic booster device can realize the lifting function.

[0046] In this embodiment, the lifting device is divided into two parts, the left and the right parts, which are exactly the same but separated from each other, leaving space directly above the sand box to avoid affecting the pouring of the aluminum liquid.

[0047] In this embodiment, eight reinforcing plates are provided at the bottom of the column 7 to maintain the stability of the support, and the column 7 is fixed to the ground by rivets.

[0048] In this embodiment, two limit blocks 8 are provided on the upper part of the column 7. The limit blocks 8 not only play a limiting role, but also can connect the cantilever 10, reduce stress concentration, and enhance the supporting stability of the column.

[0049] In this embodiment, the cantilever 10 adopts an I-shaped structure to enhance the load-bearing capacity, and the electric hoist 12 is fixed to the cantilever 10 through a connecting pin.

[0050] In this embodiment, the motors of the left and right electric hoists 12 should be connected in series to the same switch, so that the left and right sides of the electromagnetic booster module can rise and fall synchronously to ensure the stability of the lifting process.

[0051] It can be seen from the above embodiments that the present invention provides an electromagnetic assisted pressurized aluminum alloy lost foam casting forming device, wherein a liftable electromagnetic coil is placed outside the sand box. During pouring, three-phase alternating current is passed through the electromagnetic coil, and the coil winding generates a traveling wave magnetic field. The aluminum liquid generates an induced current under the action of the traveling wave magnetic field. The charged aluminum liquid cuts the magnetic flux lines during the pouring process to generate a downward constant magnetic field force, which greatly promotes the flow of aluminum alloy melt micro-clusters in the mold cavity, improves the filling power, accelerates the pouring speed, makes the filling complete, the structure refined and dense, greatly reduces the pouring defects, and improves the mechanical properties of the casting. After the pouring is completed, the electromagnetic boost module is lifted by the lifting device, and the sand box goes to the sand drop area for the next process operation. When the next sand box comes to the pouring area, the coil is put down again for pouring, and so on, which greatly reduces the difficulty of operation and improves the work efficiency. The present invention also provides a complete set of electromagnetic assisted pressurized aluminum alloy lost foam casting processes to reduce the casting defects of aluminum alloy castings and improve the mechanical properties of castings.

[0052] This embodiment also provides an electromagnetic assisted pressurized aluminum alloy lost foam casting forming method, comprising the following steps:

[0053] Step 1: Foam pattern making:

[0054] A. Foam bead foaming molding: Use an intermittent steam pre-expander to pre-foam the EPS beads, put the pre-foamed beads into the maturation chamber for maturation, preheat the mold to about 70°C, use a material gun to inject the fully matured beads into the mold cavity, pass steam to foam the beads, and demold after cooling to obtain the white mold appearance of each part of the casting.

[0055] B. Cut and glue the white molds that make up the casting, and then combine the casting white mold and the pouring system white mold into a cluster to obtain a complete pouring white mold appearance.

[0056] Step 2: Apply special coating: Apply aluminum alloy lost foam casting professional coating on the surface of the white mold, and then dry it.

[0057] Step three, vibrate the sand box: put the white mold coated with paint into the sand box, add dry sand into the sand box layer by layer, and vibrate while adding sand. Under the premise of ensuring that the mold does not deform, the dry sand in the sand box obtains a higher and more uniform filling density.

[0058] Step 4: melt purification: degassing, deslagging, refining, refining and standing treatment of the aluminum solution.

[0059] Step 5: Pouring: The sand box moves from the compaction area to the pouring area via a conveyor belt. The electric hoist is turned on, and the lifting device lowers the electromagnetic booster module. Three-phase alternating current is supplied to the winding coil to form a traveling wave magnetic field, and the pouring of molten aluminum begins. The molten aluminum generates an induced current under the action of the traveling wave magnetic field. The charged molten aluminum cuts the magnetic lines of force to obtain a downward electromagnetic driving force, quickly melting the foam white mold to form a dense, complete casting with high surface quality and good mechanical properties.

[0060] Step 6, sand dropping: reverse the electric hoist, the lifting device raises the electromagnetic booster module, the sand box moves from the pouring area to the sand dropping area via the conveyor belt, flips the sand box, pours the dry sand and castings out of the sand box, puts the castings in water for rapid cooling, vibrates and breaks or knocks the surface coating and cleans the castings.

[0061] Step 7, heat treatment: The casting is subjected to T6 heat treatment, and then the pouring system is removed by machining. Finally, the required casting is obtained after grinding, shot blasting, testing and other processes.

[0062] In this embodiment, the maximum diameter of the EPS beads in step one should not exceed 1 / 8 to 1 / 10 of the minimum wall thickness of the casting, and the bead density is selected to be 15 to 25 g / L; during pre-foaming, the pre-foaming machine pipeline pressure is controlled within 0.1 to 0.2 MPa, the expansion chamber pressure is controlled within 0.03 to 0.06 MPa, the pre-foaming temperature is controlled within 80 to 100°, the pre-foaming time is 2 to 5 minutes, and the aging time is controlled within 12 to 24 hours.

[0063] In this embodiment, the coating in step 2 is made of diatomite, mullite, sodium bentonite, CMC, PVA, water glass, an appropriate amount of additives and water, and water glass refers to an aqueous solution of sodium silicate. When used, the dry powder coating and water are mixed according to a preset ratio, and then stirred at a high speed for more than two hours, and then stirred at a low speed for two hours to ensure uniform density and viscosity; the prepared coating is evenly applied on the white mold, and then placed in the air to dry naturally for more than 24 hours, and the number of brushing times is twice. The second brushing is performed after the first brushing is completely dry. Before pouring, it is also necessary to ensure that the coating is completely dry to ensure the best coating performance.

[0064] In this embodiment, the particle size of the dry sand in step three is 70-140 meshes. During the specific vibration, XYZ three-dimensional vibration is selected, the vibration frequency is 35-50 Hz, and the amplitude is 2 mm. When filling sand, the bottom sand filling height is first determined according to the height of the casting, so that the bottom sand height is as large as possible to reduce the sand filling time, and then the sand is filled layer by layer according to the structure of the casting, so that the dry sand height after each sand filling is in the difficult-to-fill sand structure such as holes, interlayers, and corners, so as to ensure that the dry sand in the sand box obtains a higher and more uniform filling density without deformation of the shape.

[0065] In this embodiment, the melt purification process in step 4 is to transfer the molten aluminum alloy into a refining furnace, add refining agent twice at 730-750° C., and perform slag removal and argon filling twice.

[0066] In this embodiment, in step five, the frequency of the three-phase alternating current is 30-60 Hz, the current is 40-80 A, and the number of coil turns is 40-80 turns.

[0067] In this embodiment, in step seven, the heat treatment process varies with the alloy composition. Taking A356 aluminum-silicon alloy as an example, the optional heat treatment system is: solution temperature of 535-540°C, solution time of 6-8h; quenching temperature of 60-80°C, quenching time of 2-3min; aging temperature of 160-190°C, aging time of 4-8h.

[0068] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0069] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An electromagnetic assisted pressurized aluminum alloy lost foam casting forming device, characterized in that: include: Electromagnetic boost module and lifting device module; The electromagnetic boost module comprises a yoke (1), a winding coil (2), an upper fixing sleeve (3), a lower fixing sleeve (4) and a screw (5); four yokes (1) are arranged around a square sand box; the yoke (1) is made of silicon steel, the yoke (1) has six salient poles, and the coil winding (2) is respectively wound on the six salient poles; An upper fixing sleeve (3) and a lower fixing sleeve (4) are respectively mounted on the top and bottom of the magnetic yoke (1), and the upper fixing sleeve (3) and the lower fixing sleeve (4) are connected via a screw rod (5); a pull ring is provided on the upper fixing sleeve (3); the six winding coils (2) on each magnetic yoke (1) are divided into two groups, and the three winding coils (2) in each group are connected in a Y-type manner and three-phase alternating current is supplied, and the first, second, and third winding coils (2) of the six winding coils (2) from top to bottom have the same phase as the fourth, fifth, and sixth winding coils (2) when the alternating current is supplied, and the corresponding first, second, third, fourth, fifth, and sixth winding coils (2) on each magnetic yoke (1) are connected in series to ensure the same phase; The lifting device module comprises two left and right parts symmetrically arranged on both sides of the electromagnetic booster module, the left and right parts are completely identical and respectively comprise a column (7), a cantilever (10) and an electric hoist (12); the column (7) is provided with a cantilever (10), the cantilever (10) is provided with an electric hoist (12), the lower hook of the electric hoist (12) is connected to the pull ring of the upper fixing sleeve (3), and under the action of the electric hoist (12), the electromagnetic booster module realizes a lifting function.

2. The electromagnetic assisted pressurized aluminum alloy lost foam casting forming device according to claim 1, characterized in that: The width of the yoke (1) is smaller than the width of the sand box, and the distances between the salient poles of the yoke (1) are equal; Two limit bars are welded around the upper fixing sleeve (3) and the lower fixing sleeve (4), and the distance between the limit bars is the width of the yoke (1) to limit the lateral movement of the yoke (1); bolt through holes are provided on the outer sides of the limit bars for bolt connection; and pads (6) are provided at the four corners of the bottom of the lower fixing sleeve (4), and the height of the pads (6) is greater than the height of the nut at the bottom of the screw rod (5).

3. The electromagnetic assisted pressurized aluminum alloy lost foam casting forming device according to claim 2, characterized in that: In the lifting device module, a fixing plate (9) is arranged on the bracket column (7), and the cantilever (10) is connected to the fixing plate (9); eight reinforcing plates are arranged at the bottom of the column (7), and the column (7) is fixed to the ground by rivets; two limit blocks (8) are arranged on the upper part of the column (7), and the limit blocks (8) are connected to the cantilever (10).

4. The electromagnetic assisted pressurized aluminum alloy lost foam casting forming device according to claim 3 is characterized in that: The cantilever (10) adopts an I-shaped structure, and the electric hoist (12) is fixed on the cantilever (10) through a connecting pin (11).

5. The electromagnetic assisted pressurized aluminum alloy lost foam casting forming device according to claim 4, characterized in that: The motors of the left and right electric hoists (12) are connected in series on the same switch.

6. An electromagnetic assisted pressurized aluminum alloy lost foam casting forming method implemented by using the electromagnetic assisted pressurized aluminum alloy lost foam casting forming device according to claim 1, characterized in that: The following steps are involved: Step 1: Use an intermittent steam pre-expander to pre-foam the EPS beads, put the pre-foamed beads into a maturation bin for maturation, preheat the mold to 70°C, inject the fully matured beads into the mold cavity with a material gun, introduce steam to foam the beads, and demold after cooling to obtain the white mold patterns of various parts of the casting; cut and glue the white molds that make up the casting, and then combine the casting white mold and the pouring system white mold into a cluster to obtain a complete pouring white mold pattern; Step 2: coating the aluminum alloy lost foam casting coating on the surface of the white mold and then drying it; Step 3: Put the painted white mold into the sand box, add dry sand into the sand box layer by layer, and vibrate the sand while adding it. Under the premise of ensuring that the mold does not deform, the dry sand in the sand box has a higher and more uniform filling density; Step 4, degassing, deslagging, refining, refining and standing treatment of the aluminum solution; Step 5: The sand box is transported from the compaction area to the pouring area via a conveyor belt. The electric hoist is turned on, and the lifting device module lowers the electromagnetic booster module. Three-phase alternating current is supplied to the winding coil to form a traveling wave magnetic field. The aluminum liquid begins to be poured. The aluminum liquid generates an induced current under the action of the traveling wave magnetic field. The charged aluminum liquid cuts the magnetic flux lines to obtain a downward electromagnetic driving force, melts the foam white mold, and forms a casting. Step 6: Reverse the electric hoist, the lifting device module lifts the electromagnetic booster module, the sand box moves from the pouring area to the sand drop area via the conveyor belt, flips the sand box, pours the dry sand and castings from the sand box, cools the castings in water, vibrates and breaks or knocks the surface coating, and cleans the castings; Step seven, subject the casting to T6 heat treatment, then machine to remove the pouring system, and finally obtain the desired casting after grinding, shot blasting and testing processes.

7. The electromagnetic assisted pressurized aluminum alloy lost foam casting forming method according to claim 6, characterized in that: In step one, the maximum diameter of the EPS beads does not exceed 1 / 8 to 1 / 10 of the minimum wall thickness of the casting, and the bead density is selected to be 15 to 25 g / L; during pre-foaming, the pre-foaming machine pipeline pressure is controlled within 0.1 to 0.2 MPa, the expansion chamber pressure is controlled within 0.03 to 0.06 MPa, the pre-foaming temperature is controlled within 80 to 100°, the pre-foaming time is 2 to 5 minutes, and the aging time is controlled within 12 to 24 hours.

8. The electromagnetic assisted pressurized aluminum alloy lost foam casting forming method according to claim 7, characterized in that: In step 2, the coating is mixed with diatomaceous earth, mullite, sodium bentonite, CMC, PVA, water glass, additives and water. When used, the dry powder coating and water are mixed according to a preset ratio, first stirred at high speed for more than two hours, and then stirred at low speed for two hours; the prepared coating is evenly applied on the white mold, and then placed in the air to dry naturally for more than 24 hours, and the number of brushing times is twice. After the first brushing is completely dry, the second brushing is performed, and the coating is ensured to be completely dry before pouring.

9. The electromagnetic-assisted pressurized aluminum alloy lost foam casting forming method according to claim 8, characterized in that: In step three, the particle size of dry sand is 70-140 mesh. During the specific vibration, XYZ three-dimensional vibration is selected, the vibration frequency is 35-50 Hz, and the amplitude is 2 mm. When filling sand, the bottom sand filling height is first determined according to the height of the casting, and then the sand is filled layer by layer according to the structure of the casting, so that the dry sand height after each sand filling is at a structure that is difficult to fill with sand, and the difficult to fill with sand structure includes holes, interlayers, and corners.

10. The electromagnetic assisted pressurized aluminum alloy lost foam casting forming method according to claim 9, characterized in that: In step 4, the melt purification process is to transfer the molten aluminum alloy into a refining furnace, add refining agent twice at 730-750°C, and skim slag and fill with argon gas twice; In step 5, a three-phase alternating current with a frequency of 30 to 60 Hz, a current of 40 to 80 A, and 40 to 80 turns of the coil is introduced; In step seven, the alloy composition is A356 aluminum-silicon alloy, and the heat treatment process is: solution temperature is 535-540°C, solution time is 6-8h; quenching temperature is 60-80°C, quenching time is 2-3min; aging temperature is 160-190°C, aging time is 4-8h.

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