Complex-structure high-temperature alloy precision casting anti-gravity casting equipment and casting method

Abstract

The invention discloses anti-gravity casting equipment and a casting method for a high-temperature alloy precision casting with a complex structure, and belongs to the field of alloy casting. The invention aims to solve the problem that the traditional gravity casting method cannot completely meet the requirements of the ultrathin-wall high-temperature alloy casting and the like. The system comprises a vacuum unit, a smelting system, a smelting chamber, a pouring chamber, a casting mold lifting mechanism, a control system, a transfer system and an air source system. The vacuum unit is connected with the smelting chamber and the pouring chamber. The smelting system is arranged in the smelting chamber and is used for smelting high-temperature alloy; the pouring chamber is mounted at the top of the smelting chamber; the casting mold lifting mechanism is mounted in the casting chamber; the transfer system is mounted above the pouring chamber and is used for transferring the casting mold and the riser tube; the gas source system is connected with the smelting chamber and the pouring chamber and used for filling gas into the smelting chamber and the pouring chamber in the pouring process, and the control system controls starting and stopping of the vacuum unit, the casting mold lifting mechanism, the transfer system and the gas source system. The method is mainly used for preparing the amorphous alloy forming part.

Description

Technical Field

[0001] The invention belongs to the field of alloy casting, and in particular relates to a counter-gravity casting device and a casting method for high-temperature alloy precision castings with complex structures. Background Art

[0002] Nickel-based, iron-based and other alloy materials have excellent toughness, processing performance, high temperature strength and high temperature thermal stability. Therefore, this type of alloy has always played an important role in the field of aero-engines. Since high-temperature alloys contain W, Nb, Ta, Ti, Al and other elements that are easily oxidized during the smelting process, traditional aero-engine castings use a smelting and gravity pouring process in a vacuum environment, and the vacuum environment effectively avoids the oxidation of alloy elements. However, this method of freely filling the mold based on the density of the alloy liquid has the problems of slow filling speed and weak filling capacity, resulting in complex casting structure and insufficient filling of thin walls; when the alloy liquid solidifies, the shrinkage compensation ability is poor, resulting in shrinkage cavities and shrinkage. At present, appearance defects and internal quality in aero-engine castings are the main scrap rates. Today, the pursuit of lightweight and ultra-high speed aircraft goals, in addition to the requirements for alloy materials, is mainly reflected in the optimization design and manufacturing process of casting structures. The main castings of the next generation of engines must be made into ultra-thin walls (<1.25mm). In addition, the area of ​​the ultra-thin wall area (area>200mm×200mm) in the casting accounts for no less than 80%. The traditional gravity casting method cannot meet the requirements of such ultra-thin wall high-temperature alloy castings. It is necessary to seek a certain process method to achieve the complete forming of ultra-thin wall high-temperature alloy castings, the compactness of the macrostructure (reducing shrinkage cavities and shrinkage) and the microstructure (micro-shrinkage). In order to meet the above needs, a reverse gravity filling forming equipment and process method for ultra-thin wall and complex structure high-temperature alloy precision castings was invented. Summary of the invention

[0003] In view of this, the present invention provides a counter-gravity casting device and a casting method for high-temperature alloy precision castings with complex structures, which utilizes counter-gravity to press the molten alloy in the melting crucible into the mold cavity of the casting mold and solidify it to form a casting.

[0004] The technical solution adopted by the present invention to solve the above technical problems is:

[0005] A counter-gravity casting device for high-temperature alloy precision castings with complex structures, comprising a vacuum unit, a smelting system, a smelting chamber, a pouring chamber, a mold lifting mechanism, a control system, a transfer system and a gas source system; the vacuum unit is respectively connected to the smelting chamber and the pouring chamber and is used for evacuating the smelting chamber and the pouring chamber; the smelting system is arranged in the smelting chamber and is used for smelting the high-temperature alloy; the pouring chamber is installed on the top of the smelting chamber and is communicated with each other; the mold lifting mechanism is installed in the pouring chamber and is used for vertically lifting the mold before and after pouring; the transfer system is installed above the pouring chamber and is used for transferring the mold and the liquid riser; the gas source system is respectively connected to the smelting chamber and the pouring chamber and is used for filling the smelting chamber and the pouring chamber with gas during the pouring process, and the control system respectively controls the opening and closing of the vacuum unit, the mold lifting mechanism, the transfer system and the gas source system.

[0006] Furthermore, the vacuum unit includes a slide valve pump, a Roots pump, a diffusion pump, a main exhaust pipe, two branch exhaust pipes, a main exhaust valve, a pouring chamber exhaust valve and a smelting chamber exhaust valve. The slide valve pump, the Roots pump and the diffusion pump are connected in sequence. The diffusion pump is connected to the smelting chamber and the pouring chamber via the main exhaust pipe and the two branch exhaust pipes, respectively. The main exhaust valve is installed on the main exhaust pipe. The pouring chamber exhaust valve is installed on one of the branch exhaust pipes and is used to control the vacuumization of the pouring chamber. The smelting chamber exhaust valve is installed on the other branch exhaust pipe and is used to control the vacuumization of the smelting chamber.

[0007] Furthermore, the smelting system includes an induction coil, a smelting crucible, a crucible turning mechanism, a water supply mechanism and a medium-frequency induction power supply. The induction coil is wound around the outside of the smelting crucible and is electrically connected to the medium-frequency induction power supply. The water supply mechanism is connected to the circulating cooling water system in the smelting crucible and is used for cooling the smelting crucible. The crucible turning mechanism is connected to the smelting crucible and is used for turning the smelting crucible.

[0008] Furthermore, the smelting chamber comprises a smelting chamber shell, a smelting chamber door, a secondary feeding mechanism, a gate valve, a temperature measuring mechanism, a middle diaphragm, a first sealing ring and a smelting chamber exhaust valve, wherein the smelting chamber door is installed at the opening of the smelting chamber shell, the secondary feeding mechanism is installed in the smelting chamber shell and is used for secondary feeding of the smelting crucible, the middle diaphragm is installed between the smelting chamber and the pouring chamber, the middle diaphragm is provided with a center hole, the first sealing ring is installed at the center hole of the middle diaphragm, the gate valve is movably installed on the middle diaphragm and opens or closes the center hole of the middle diaphragm, the temperature measuring mechanism is used to measure the temperature of the smelting chamber, and the smelting chamber exhaust valve is installed on the exhaust pipe of the smelting chamber.

[0009] Furthermore, the pouring chamber includes a pouring chamber shell, a pouring chamber side door, a pouring chamber top door, an observation hole and a pouring chamber exhaust valve. The pouring chamber shell is provided with an upper opening and a side opening. The pouring chamber top door is movably mounted at the upper opening of the pouring chamber shell. The pouring chamber side door is movably mounted at the side opening of the pouring chamber shell. The observation hole is mounted on the side wall of the pouring chamber shell to observe the internal situation. The pouring chamber exhaust valve is mounted on the exhaust pipe of the pouring chamber.

[0010] Furthermore, the mold lifting mechanism includes a drive motor, two right-angle steering mechanisms, two lead screws, two lead screw nuts, a guide column, a mold movable plate and a second sealing ring. The drive motor is installed at the top of the pouring chamber and is respectively connected to the two lead screws via two right-angle steering mechanisms. Each lead screw nut is screwed to a lead screw. The mold movable plate is connected to the two lead screw nuts, and an opening is provided on the mold movable plate. The second sealing ring is installed at the opening of the mold movable plate.

[0011] Furthermore, the transfer system includes a load-bearing steel frame, a linear guide rail, a hydraulic motor, a horizontal moving mechanism, a crane, a lifting drive motor, a lifting mechanism and a manipulator. The load-bearing steel frame is installed on the top of the pouring chamber, the linear guide rail is installed on the load-bearing steel frame, the crane is connected to the linear guide rail and can be driven by a hydraulic motor and a horizontal moving mechanism to move along the linear guide rail, the lifting mechanism is installed on the crane, the manipulator is installed on the lifting mechanism, and the lifting drive motor drives the lifting mechanism to drive the manipulator to lift and lower.

[0012] Furthermore, the gas source system includes a gas generator, a gas storage tank, a main air inlet valve, a main air inlet pipeline, two branch air inlet pipelines, a pouring chamber air inlet valve and a smelting chamber air inlet valve, the gas generator is connected to the air inlet of the gas storage tank, the air outlet of the gas storage tank is respectively connected to the smelting chamber and the pouring chamber via the main air inlet pipeline and the two branch air inlet pipelines, the main air inlet valve is installed on the main air inlet pipeline, the pouring chamber air inlet valve is installed on one of the branch air inlet pipelines and is used to control the inflation of the pouring chamber, and the smelting chamber air inlet valve is installed on the other branch air inlet pipeline and is used to control the inflation of the smelting chamber.

[0013] A counter-gravity casting method for complex structure high-temperature alloy precision castings, the specific casting process is as follows:

[0014] S1, placing a high-temperature alloy prefabricated ingot into a melting crucible, and closing the valve to seal the melting chamber;

[0015] S2, cooling the equipment, opening the exhaust valve of the smelting chamber, starting the vacuum unit and evacuating the smelting chamber until the vacuum degree of the smelting chamber meets the smelting requirements;

[0016] S3, starting the medium frequency induction power supply and energizing the induction coil to start melting the alloy;

[0017] S4, using the transfer system to move the riser pipe to the top of the pouring chamber, the transfer system drives the riser pipe to pass through the upper opening of the pouring chamber and the center hole of the mold moving plate until the riser pipe flange is pressed on the first sealing ring; the manipulator releases the riser pipe and moves it to reset; the manipulator moves the mold to the top of the pouring chamber, the transfer system drives the mold to pass through the upper opening of the pouring chamber and put it on the mold moving plate, and closes the top door of the pouring chamber;

[0018] S5, locking the side door and top door of the pouring chamber to achieve an independent sealing state of the pouring chamber;

[0019] S6, opening the exhaust valve of the pouring chamber, using the vacuum unit to evacuate the pouring chamber, and at the same time starting the temperature measuring mechanism of the melting chamber to measure the temperature of the alloy liquid in the melting crucible;

[0020] S7, when the vacuum degree of the pouring chamber is equal to that of the smelting chamber and the alloy liquid meets the pouring process requirements, stop evacuating; open the gate valve on the middle partition to make the pouring chamber and the smelting chamber communicate with each other;

[0021] S8, the mold lifting mechanism pushes the mold moving plate down, and the mold moving plate drives the liquid riser to pass through the central hole of the middle partition and enter the smelting chamber, and the liquid riser extends into the alloy liquid in the smelting crucible until the mold moving plate abuts against the middle partition;

[0022] S9, using the gas source system to inflate the smelting chamber and the pouring chamber. When the gas pressure in the smelting chamber and the pouring chamber reaches the set pressure P0, the pouring chamber air inlet valve is closed to stop the gas supply, and the pouring chamber exhaust valve is opened to exhaust the gas, so that the pressure Pt in the pouring chamber is gradually less than the pressure P0 in the smelting chamber, and a pressure difference ΔP=P0-Pt is formed; when the pressure difference reaches a critical value, the alloy liquid in the smelting crucible rises along the riser pipe and continuously enters the casting mold cavity, and the liquid rise pouring starts according to the set process curve. During the pouring process, according to the cross-sectional structural characteristics of the casting, the control system controls the pouring speed by adjusting the liquid riser pressure to achieve the set ideal state of the process curve; at the same time, the smelting chamber air inlet valve is in a gas replenishing state to maintain the pressure in the smelting chamber at 0.35-0.65Mpa;

[0023] S10, when the molten metal fills the mold, the crystallization pressure, feeding pressure and holding time are automatically adjusted to ensure the casting is obtained;

[0024] S11, when it is detected that the liquid alloy in the sprue of the casting mold solidifies into a solid, the exhaust valve of the pouring chamber is closed, the exhaust valve of the melting chamber is opened, and the inert gas in the melting chamber is discharged to make the gas pressure in the melting chamber equal to the gas pressure in the pouring chamber, and the liquid metal that has not yet solidified in the riser tube flows back into the melting crucible; at this time, the casting in the pouring chamber is still in a state of crystallization and solidification under pressure;

[0025] S12, when the control system detects that the casting has completed solidification and cooled to a suitable temperature, it controls the casting mold moving plate of the pouring chamber to rise and drive the riser tube to separate from the melting crucible, completing the counter-gravity filling and pouring process of the high-temperature alloy casting and completing the counter-gravity casting of the casting.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. In the process of preparing the high-temperature alloy castings of the present invention, vacuum and inert gas protection smelting and pouring are used to isolate the invasion of oxygen elements, avoid the oxidation of active elements such as Al, Ti, W in the alloy, and produce high-quality castings.

[0028] 2. In the present invention, the molten metal is filled into the mold against the direction of gravity, which ensures that the high-temperature alloy liquid fills the mold smoothly, avoids the tumbling and splashing of the alloy liquid during filling, and thus reduces the formation of air entrapment and slag inclusion.

[0029] 3. The filling speed of the present invention can be adjusted and can be accurately and precisely controlled according to the process requirements. The alloy liquid is driven to fill the casting mold under pressure, which solves the difficulty of forming large-size, thin-walled, and complex-structure high-temperature alloy castings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The accompanying drawings are incorporated as part of this application and are used to provide a further understanding of the present invention.

[0031] Figure 1 The structure of the complex structure high temperature alloy precision casting anti-gravity casting equipment of the embodiment of the present application is schematically shown. Figure 1 .

[0032] Figure 2 This is a top view of the anti-gravity casting equipment for complex structure high-temperature alloy precision castings according to an embodiment of the present application.

[0033] Figure 3 The structure of the complex structure high temperature alloy precision casting anti-gravity casting equipment of the embodiment of the present application is schematically shown. Figure 2 . DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with specific embodiments.

[0035] Embodiment 1:

[0036] The present embodiment provides a counter-gravity casting equipment for high-temperature alloy precision castings with complex structures, including a vacuum unit, a melting system, a melting chamber, a pouring chamber, a mold lifting mechanism, a control system, a transfer system and a gas source system; the vacuum unit is respectively connected to the melting chamber and the pouring chamber and is used for vacuuming the melting chamber and the pouring chamber; the melting system is arranged in the melting chamber and is used for melting the high-temperature alloy; the pouring chamber is installed on the top of the melting chamber and is communicated with each other; the mold lifting mechanism is installed in the pouring chamber and is used for vertically lifting the mold before and after pouring; the transfer system is installed above the pouring chamber and is used for transferring the mold and the liquid riser; the gas source system is respectively connected to the melting chamber and the pouring chamber and is used to fill the melting chamber and the pouring chamber with gas during the pouring process, and the control system controls the opening and closing of the vacuum unit, the mold lifting mechanism, the transfer system and the gas source system respectively.

[0037] Wherein, the vacuum unit comprises a slide valve pump 1.1, a Roots pump 1.2, a diffusion pump 1.3, a main exhaust pipe, two branch exhaust pipes, a main exhaust valve D1, a pouring chamber exhaust valve D2 and a smelting chamber exhaust valve D3. The slide valve pump 1.1, the Roots pump 1.2 and the diffusion pump 1.3 are connected in sequence. The diffusion pump 1.3 is connected to the smelting chamber and the pouring chamber via the main exhaust pipe and the two branch exhaust pipes respectively. The main exhaust valve D1 is installed on the main exhaust pipe, the pouring chamber exhaust valve D2 is installed on one of the branch exhaust pipes and is used to control the vacuumization of the pouring chamber, and the smelting chamber exhaust valve D3 is installed on the other branch exhaust pipe and is used to control the vacuumization of the smelting chamber.

[0038] The smelting system includes an induction coil 2.1, a smelting crucible 2.2, a crucible turning mechanism 2.3, a water supply mechanism and a medium-frequency induction power supply 2.4. The induction coil 2.1 is wound around the outside of the smelting crucible 2.2 and is electrically connected to the medium-frequency induction power supply 2.4. The water supply mechanism is connected to the circulating cooling water system in the smelting crucible 2.2 and is used for cooling the smelting crucible 2.2. The crucible turning mechanism 2.3 is connected to the smelting crucible 2.2 and is used for turning the smelting crucible 2.2.

[0039] The smelting chamber comprises a smelting chamber shell 3.1, a smelting chamber door 3.2, a secondary feeding mechanism 3.3, a gate valve 3.4, a temperature measuring mechanism 3.5, a middle diaphragm 3.6, a first sealing ring 3.7 and a smelting chamber exhaust valve D5. The smelting chamber door 3.2 is installed at the opening of the smelting chamber shell 3.1. The secondary feeding mechanism 3.3 is installed in the smelting chamber shell 3.1 and is used for secondary feeding of the smelting crucible 2.2. The middle diaphragm 3.6 is installed between the smelting chamber and the pouring chamber. The middle diaphragm 3.6 is provided with a center hole. The first sealing ring 3.7 is installed at the center hole of the middle diaphragm 3.6. The gate valve 3.4 is movably installed on the middle diaphragm 3.6 and opens or closes the center hole of the middle diaphragm 3.6. The temperature measuring mechanism 3.5 is used to measure the temperature of the smelting chamber. The smelting chamber exhaust valve D5 is installed on the exhaust pipe of the smelting chamber.

[0040] Wherein, the pouring chamber comprises a pouring chamber shell 4.1, a pouring chamber side door 4.2, a pouring chamber top door 4.3, an observation hole 4.4 and a pouring chamber exhaust valve D8. The pouring chamber shell 4.1 is provided with an upper opening and a side opening. The pouring chamber top door 4.3 is movably installed at the upper opening of the pouring chamber shell 4.1. The pouring chamber side door 4.2 is movably installed at the side opening of the pouring chamber shell 4.1. The observation hole 4.4 is installed on the side wall of the pouring chamber shell 4.1 to observe the internal situation. The pouring chamber exhaust valve D8 is installed on the exhaust pipe of the pouring chamber.

[0041] Among them, the mold lifting mechanism includes a driving motor 5.1, two right-angle steering mechanisms 5.2, two lead screws 5.3, two lead screw nuts, a guide column 5.4, a mold movable plate 5.5 and a second sealing ring 5.6. The driving motor 5.1 is installed on the top of the pouring chamber and is respectively connected to the two lead screws 5.3 via two right-angle steering mechanisms 5.2. Each lead screw nut is screwed to a lead screw 5.3. The mold movable plate 5.5 is connected to the two lead screw nuts, and an opening is provided on the mold movable plate 5.5. The second sealing ring 5.6 is installed at the opening of the mold movable plate 5.5.

[0042] Among them, the transfer system includes a bearing steel frame 7.1, a linear guide 7.2, a hydraulic motor 7.3, a horizontal moving mechanism 7.4, a crane 7.5, a lifting drive motor 7.6, a lifting mechanism 7.7 and a manipulator 7.8. The bearing steel frame 7.1 is installed on the top of the casting chamber, the linear guide 7.2 is installed on the bearing steel frame 7.1, the crane 7.5 is connected to the linear guide 7.2 and can be driven by the hydraulic motor 7.3 and the horizontal moving mechanism 7.4 to move along the linear guide 7.2, the lifting mechanism 7.7 is installed on the crane 7.5, the manipulator 7.8 is installed on the lifting mechanism 7.7, and the lifting drive motor 7.6 drives the lifting mechanism 7.7 to drive the manipulator 7.8 to rise and fall.

[0043] Wherein, the gas source system includes a gas generator 8.1, a gas storage tank 8.2, a main air inlet valve D4, a main air inlet pipeline, two branch air inlet pipelines, a pouring chamber air inlet valve D6 and a smelting chamber air inlet valve D7. The gas generator 8.1 is connected to the air inlet of the gas storage tank 8.2, and the air outlet of the gas storage tank 8.2 is respectively connected to the smelting chamber and the pouring chamber via the main air inlet pipeline and the two branch air inlet pipelines. The main air inlet valve D4 is installed on the main air inlet pipeline, the pouring chamber air inlet valve D6 is installed on one of the branch air inlet pipelines and is used to control the inflation of the pouring chamber, and the smelting chamber air inlet valve D7 is installed on the other branch air inlet pipeline and is used to control the inflation of the smelting chamber.

[0044] Embodiment 2:

[0045] This embodiment provides a counter-gravity casting method for high-temperature alloy precision castings with complex structures. The specific casting process is as follows:

[0046] S1, put the high temperature alloy prefabricated ingot into the melting crucible 2.2, put the alloy material to be added for the second time into the secondary feeding hopper of the secondary feeding mechanism 3.3, close the gate valve 3.4 between the melting chamber and the pouring chamber, the main air inlet valve D4, the pouring chamber air inlet valve D6, the melting chamber air inlet valve D7, the melting chamber exhaust valve D5 and the pouring chamber exhaust valve D8; at this time, the melting chamber is in a sealed state;

[0047] S2, the control system starts the cooling water system, cools all parts of the equipment that need cooling, closes the pouring chamber air inlet valve D6, opens the smelting chamber exhaust valve D3, starts the vacuum unit and evacuates the smelting chamber;

[0048] S3, when the vacuum degree of the smelting chamber meets the smelting requirements, start the medium frequency induction power supply 2.4 and energize the induction coil 2.1 to start smelting the alloy. When the high temperature alloy prefabricated ingot is completely melted, if additional alloy material is needed, the alloy material in the secondary feeding hopper can be added to the smelting crucible 2.2 to continue smelting;

[0049] S4, using the manipulator 7.8 of the transfer system to grab the liquid riser, the hydraulic motor 7.3 drives the horizontal moving mechanism 7.4 to drive the traveling crane 7.5 to move horizontally along the linear guide rail 7.2 until the liquid riser moves to the top of the pouring chamber, and the top door 4.3 of the pouring chamber is opened, the lifting drive motor 7.6 drives the lifting mechanism 7.7 to move vertically, and drives the liquid riser through the center hole of the mold moving plate 5.5 through the manipulator 7.8 until the liquid riser flange is pressed on the first sealing ring 3.7; the manipulator 7.8 releases the liquid riser and moves to reset, the manipulator 7.8 grabs the mold, the hydraulic motor 7.3 drives the horizontal moving mechanism 7.4 to drive the traveling crane 7.5 to move horizontally along the linear guide rail 7.2 until the mold moves to the top of the pouring chamber, and the top door 4.3 of the pouring chamber is opened, the lifting drive motor 7.6 drives the lifting mechanism 7.7 to move vertically, and the mold is placed on the mold moving plate 5.5 of the pouring chamber through the manipulator 7.8; the top door 4.3 of the pouring chamber is closed;

[0050] S5, locking the pouring chamber side door 4.2 and the pouring chamber top door 4.3 to achieve an independent sealing state of the pouring chamber;

[0051] S6, open the pouring chamber exhaust valve D2, use the vacuum unit to evacuate the pouring chamber, and start the melting chamber temperature measuring mechanism 3.5 to measure the temperature of the alloy liquid in the melting crucible;

[0052] S7, when the vacuum degree of the pouring chamber is equal to that of the smelting chamber and the alloy liquid meets the pouring process requirements, close the main exhaust valve D1, the pouring chamber exhaust valve D2 and the smelting chamber exhaust valve D3, close the vacuum unit and stop the vacuum pumping; open the gate valve 3.4 on the middle partition plate 3.6 to make the pouring chamber and the smelting chamber communicate with each other, so that the pressure of the pouring chamber and the smelting chamber is equal;

[0053] S8, the mold lifting motor drives the lead screw 5.3 to rotate via the right-angle steering mechanism 5.2, and the lead screw nut pushes the mold movable plate 5.5 to descend, and the mold movable plate 5.5 drives the liquid riser to pass through the central hole of the middle partition plate 3.6 and enter the smelting chamber, and the liquid riser extends into the alloy liquid in the smelting crucible 2.2 until the mold movable plate 5.5 abuts against the first sealing ring 3.7 on the middle partition plate 3.6. At this time, the mold is also placed in place, and there is an upper sealing ring of the liquid riser between the mold and the liquid riser, a lower sealing ring of the liquid riser between the liquid riser and the mold movable plate 5.5, and a first sealing ring 3.7 between the mold movable plate 5.5 and the middle partition plate 3.6. The pouring chamber and the smelting chamber are separated into two independent sealing structures by the middle partition plate 3.6. Only the liquid riser connects the alloy liquid in the crucible of the smelting chamber with the mold cavity of the pouring chamber, and is in a state of waiting for pouring;

[0054] S9, after confirming that the exhaust valve D5 of the smelting chamber and the exhaust valve D8 of the pouring chamber are both in the closed state, the air inlet valve D7 of the smelting chamber, the air inlet valve D6 of the pouring chamber and the main air inlet valve D4 are opened at the same time, so that the smelting chamber and the pouring chamber are filled with gas at the same time. When the gas pressure in the smelting chamber and the pouring chamber reaches the set pressure P0 (0.35-0.65Mpa), the air inlet valve D6 of the pouring chamber is closed to stop the input of gas, and the exhaust valve D8 of the pouring chamber is opened to slowly discharge the gas in the pouring chamber, so that the pressure Pt in the pouring chamber is gradually less than the pressure P0 in the smelting chamber, forming a pressure difference ΔP=P0-Pt; when the pressure difference reaches a certain When the critical value (ΔP=0.25-0.55Mpa) is reached, under the action of this pressure difference, the alloy liquid in the crucible of the melting chamber is driven to rise along the liquid riser against the direction of gravity and continuously enter the casting cavity of the pouring chamber, and the liquid rise pouring begins according to the set process curve. During the pouring process, according to the cross-sectional structural characteristics of the casting, the control system controls the pouring speed by adjusting the liquid riser pressure to achieve the set ideal state of the process curve; at the same time, the melting chamber air inlet valve D7 is in the intelligent control air supply state to maintain the pressure in the melting chamber at the set level of 0.35-0.65Mpa;

[0055] S10, when the control system receives the feedback signal from the mold top sensor that the molten metal fills the mold, it automatically adjusts the crystallization pressure, shrinkage feeding pressure, and holding time to fully ensure that a dense, high-quality casting without defects such as shrinkage cavities and shrinkage porosity is obtained;

[0056] S11, when the computer control center detects that the liquid alloy in the sprue of the casting mold solidifies into a solid, the pouring chamber exhaust valve D8 is closed and the melting chamber exhaust valve D5 is opened to discharge the inert gas in the melting chamber. When the gas pressure in the melting chamber is equal to the gas pressure in the pouring chamber, the liquid metal that has not yet solidified in the riser tube flows back into the crucible by its own gravity; at this time, the casting in the pouring chamber is still in a state of crystallization and solidification under pressure;

[0057] S12, when the control system detects that the casting has completed solidification and cooled to a suitable temperature, it controls the casting mold moving plate 5.5 of the pouring chamber to rise and drive the riser tube to separate from the melting crucible 2.2; the pouring chamber exhaust valve D8 and the melting chamber exhaust valve D5 are opened to evacuate the remaining gas, and when the pressure in the melting chamber and the pouring chamber is equal to the external pressure, the equipment will sound a safety whistle; at this point, the counter-gravity filling and pouring process of the high-temperature alloy casting is completed; when the melting crucible 2.2 and the riser tube and other parts with residual heat are cooled to a safe temperature, the melting chamber door 3.2 is opened to clean the melting crucible 2.2; the pouring chamber top door 4.3 is opened to take out the high-temperature alloy casting, and the counter-gravity casting of the casting is completed.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An anti-gravity casting equipment for high-temperature alloy precision castings with complex structures, characterized by: It includes a vacuum unit, a smelting system, a smelting chamber, a pouring chamber, a mold lifting mechanism, a control system, a transfer system and a gas source system; the vacuum unit is respectively connected to the smelting chamber and the pouring chamber and is used for evacuating the smelting chamber and the pouring chamber; the smelting system is arranged in the smelting chamber and is used for smelting high-temperature alloys; the pouring chamber is installed on the top of the smelting chamber and is communicated with the smelting chamber; the mold lifting mechanism is installed in the pouring chamber and is used for vertically lifting the mold before and after pouring; the transfer system is installed above the pouring chamber and is used for transferring the mold and the liquid riser; the gas source system is respectively connected to the smelting chamber and the pouring chamber and is used for filling the smelting chamber and the pouring chamber with gas during the pouring process, and the control system controls the opening and closing of the vacuum unit, the mold lifting mechanism, the transfer system and the gas source system respectively.

2. According to claim 1, a complex structure high temperature alloy precision casting counter-gravity casting equipment is characterized by: The vacuum unit comprises a slide valve pump, a Roots pump, a diffusion pump, a main exhaust pipe, two branch exhaust pipes, a main exhaust valve, a pouring chamber exhaust valve and a smelting chamber exhaust valve. The slide valve pump, the Roots pump and the diffusion pump are connected in sequence. The diffusion pump is connected to the smelting chamber and the pouring chamber via the main exhaust pipe and the two branch exhaust pipes respectively. The main exhaust valve is installed on the main exhaust pipe. The pouring chamber exhaust valve is installed on one of the branch exhaust pipes and is used to control the vacuum pumping of the pouring chamber. The smelting chamber exhaust valve is installed on the other branch exhaust pipe and is used to control the vacuum pumping of the smelting chamber.

3. The complex structure high temperature alloy precision casting counter-gravity casting equipment according to claim 2 is characterized by: The smelting system includes an induction coil, a smelting crucible, a crucible turning mechanism, a water supply mechanism and a medium-frequency induction power supply. The induction coil is wound around the outside of the smelting crucible and is electrically connected to the medium-frequency induction power supply. The water supply mechanism is connected to a circulating cooling water system in the smelting crucible and is used for cooling the smelting crucible. The crucible turning mechanism is connected to the smelting crucible and is used for turning the smelting crucible.

4. The complex structure high temperature alloy precision casting counter-gravity casting equipment according to claim 3, characterized in that: The smelting chamber comprises a smelting chamber shell, a smelting chamber door, a secondary feeding mechanism, a gate valve, a temperature measuring mechanism, a middle diaphragm, a first sealing ring and a smelting chamber exhaust valve. The smelting chamber door is installed at the opening of the smelting chamber shell. The secondary feeding mechanism is installed in the smelting chamber shell and is used for secondary feeding of the smelting crucible. The middle diaphragm is installed between the smelting chamber and the pouring chamber. The middle diaphragm is provided with a center hole. The first sealing ring is installed at the center hole of the middle diaphragm. The gate valve is movably installed on the middle diaphragm and opens or closes the center hole of the middle diaphragm. The temperature measuring mechanism is used to measure the temperature of the smelting chamber. The smelting chamber exhaust valve is installed on the exhaust pipe of the smelting chamber.

5. The complex structure high temperature alloy precision casting counter gravity casting equipment according to claim 4, characterized in that: The pouring chamber comprises a pouring chamber shell, a pouring chamber side door, a pouring chamber top door, an observation hole and a pouring chamber exhaust valve. The pouring chamber shell is provided with an upper opening and a side opening. The pouring chamber top door is movably mounted at the upper opening of the pouring chamber shell, the pouring chamber side door is movably mounted at the side opening of the pouring chamber shell, the observation hole is mounted on the side wall of the pouring chamber shell to observe the internal situation; the pouring chamber exhaust valve is mounted on the exhaust pipe of the pouring chamber.

6. The complex structure high temperature alloy precision casting counter-gravity casting equipment according to claim 5, characterized in that: The mold lifting mechanism includes a drive motor, two right-angle steering mechanisms, two lead screws, two lead screw nuts, a guide column, a mold movable plate and a second sealing ring. The drive motor is installed on the top of the pouring chamber and is connected to the two lead screws respectively via two right-angle steering mechanisms. Each lead screw nut is screwed to a lead screw. The mold movable plate is connected to the two lead screw nuts, and an opening is provided on the mold movable plate. The second sealing ring is installed at the opening of the mold movable plate.

7. The complex structure high temperature alloy precision casting counter gravity casting equipment according to claim 6, characterized in that: The transfer system includes a load-bearing steel frame, a linear guide rail, a hydraulic motor, a horizontal moving mechanism, a crane, a lifting drive motor, a lifting mechanism and a manipulator. The load-bearing steel frame is installed on the top of the casting chamber, the linear guide rail is installed on the load-bearing steel frame, the crane is connected to the linear guide rail and can be driven by a hydraulic motor and a horizontal moving mechanism to move along the linear guide rail, the lifting mechanism is installed on the crane, the manipulator is installed on the lifting mechanism, and the lifting drive motor drives the lifting mechanism to drive the manipulator to lift and lower.

8. The complex structure high temperature alloy precision casting counter gravity casting equipment according to claim 7, characterized in that: The gas source system includes a gas generator, a gas storage tank, a main air inlet valve, a main air inlet pipeline, two branch air inlet pipelines, a pouring chamber air inlet valve and a smelting chamber air inlet valve. The gas generator is connected to the air inlet of the gas storage tank, and the air outlet of the gas storage tank is respectively connected to the smelting chamber and the pouring chamber via the main air inlet pipeline and the two branch air inlet pipelines. The main air inlet valve is installed on the main air inlet pipeline, the pouring chamber air inlet valve is installed on one of the branch air inlet pipelines and is used to control the inflation of the pouring chamber, and the smelting chamber air inlet valve is installed on the other branch air inlet pipeline and is used to control the inflation of the smelting chamber.

9. A method for counter-gravity casting of complex structure high-temperature alloy precision castings, characterized in that: The anti-gravity casting device according to claim 8 is used to realize casting, and the specific casting process is as follows: S1, placing a high-temperature alloy prefabricated ingot into a melting crucible, and closing the valve to seal the melting chamber; S2, cooling the equipment, opening the exhaust valve of the smelting chamber, starting the vacuum unit and evacuating the smelting chamber until the vacuum degree of the smelting chamber meets the smelting requirements; S3, starting the medium frequency induction power supply and energizing the induction coil to start melting the alloy; S4, using the transfer system to move the riser pipe to the top of the pouring chamber, the transfer system drives the riser pipe to pass through the upper opening of the pouring chamber and the center hole of the mold moving plate until the riser pipe flange is pressed on the first sealing ring; the manipulator releases the riser pipe and moves it to reset; the manipulator moves the mold to the top of the pouring chamber, the transfer system drives the mold to pass through the upper opening of the pouring chamber and put it on the mold moving plate, and closes the top door of the pouring chamber; S5, locking the side door and top door of the pouring chamber to achieve an independent sealing state of the pouring chamber; S6, opening the exhaust valve of the pouring chamber, using the vacuum unit to evacuate the pouring chamber, and at the same time starting the temperature measuring mechanism of the melting chamber to measure the temperature of the alloy liquid in the melting crucible; S7, when the vacuum degree of the pouring chamber is equal to that of the smelting chamber and the alloy liquid meets the pouring process requirements, stop evacuating; open the gate valve on the middle partition to make the pouring chamber and the smelting chamber communicate with each other; S8, the mold lifting mechanism pushes the mold moving plate down, and the mold moving plate drives the liquid riser to pass through the central hole of the middle partition and enter the smelting chamber, and the liquid riser extends into the alloy liquid in the smelting crucible until the mold moving plate abuts against the middle partition; S9, using the gas source system to inflate the smelting chamber and the pouring chamber. When the gas pressure in the smelting chamber and the pouring chamber reaches the set pressure P0, the pouring chamber air inlet valve is closed to stop the gas supply, and the pouring chamber exhaust valve is opened to exhaust the gas, so that the pressure Pt in the pouring chamber is gradually less than the pressure P0 in the smelting chamber, and a pressure difference ΔP=P0-Pt is formed; when the pressure difference reaches a critical value, the alloy liquid in the smelting crucible rises along the riser pipe and continuously enters the casting mold cavity, and the liquid rise pouring starts according to the set process curve. During the pouring process, according to the cross-sectional structural characteristics of the casting, the control system controls the pouring speed by adjusting the liquid riser pressure to achieve the set ideal state of the process curve; at the same time, the smelting chamber air inlet valve is in a gas replenishing state to maintain the pressure in the smelting chamber at 0.35-0.65Mpa; S10, when the molten metal fills the mold, the crystallization pressure, feeding pressure and holding time are automatically adjusted to ensure the casting is obtained; S11, when it is detected that the liquid alloy in the sprue of the casting mold solidifies into a solid, the exhaust valve of the pouring chamber is closed, the exhaust valve of the melting chamber is opened, and the inert gas in the melting chamber is discharged to make the gas pressure in the melting chamber equal to the gas pressure in the pouring chamber, and the liquid metal that has not yet solidified in the riser tube flows back into the melting crucible; at this time, the casting in the pouring chamber is still in a state of crystallization and solidification under pressure; S12, when the control system detects that the casting has completed solidification and cooled to a suitable temperature, it controls the casting mold moving plate of the pouring chamber to rise and drive the riser tube to separate from the melting crucible, completing the counter-gravity filling and pouring process of the high-temperature alloy casting and completing the counter-gravity casting of the casting.

Images