CN118106475A - Mixed casting device and process thereof - Google Patents

Abstract

The invention discloses a mixed casting device and a process thereof, wherein the first aspect of the mixed casting device comprises a workbench, a sprue bush, a lower die, an upper die and a molten metal temperature regulating furnace, wherein a die cavity is formed between the lower die and the upper die, a sprue is arranged in the middle of the inner wall of the lower die, the molten metal temperature regulating furnace comprises a casting chamber, a pressurizing chamber and a first switch valve, the casting chamber is provided with a protective gas charging valve, the die cavity comprises an air outlet cavity, a workpiece cavity, a die forging cavity and an exhaust passage, the middle of the upper die is connected with a feeding pressure head in a sliding manner, and the inside of one side of the upper die is connected with a die forging pressure head in a sliding manner; in a second aspect, a hybrid casting process, for casting by a hybrid casting apparatus as described above, comprises the steps of: s1, aluminum alloy liquid temperature regulation; s2, die assembly and die locking; s3, evacuating a die cavity and preprocessing molten metal; s4, air pressure sealing pouring; s5: incremental pressure feeding; s6, performing waste heat die forging; s7, opening the die and taking out the part; the molding quality of the cast workpiece is improved and is comparable to that of solid die forging.

Description

Mixed casting device and process thereof

Technical Field

The invention relates to the technical field of casting equipment and a process thereof, in particular to a mixed casting device and a process thereof.

Background

The metal forming process is very diverse. The present background mainly discusses the disadvantages of two processes, namely casting and die forging.

1. Common casting process defects:

(1) Common casting processes include low pressure casting processes, which refer to pressing a metal melt into a metal mold cavity or sand mold cavity with a gas pressure of less than 600kpa, and pressure maintaining solidification forming. However, the low-pressure casting process has the defects of small gas pressure, incapability of realizing high-pressure feeding, low product density and low mechanical property;

(2) For example, CN103691907A, patent name: a Chinese patent application of low pressure casting device and low pressure casting technology, the technical scheme of the patent application is summarized as follows: the method comprises the steps that a mold closed pressurizing plenum chamber is directly arranged outside a casting mold, inert gas is introduced into the mold closed pressurizing plenum chamber to isolate air from contacting with a metal melt, and the defect of oxide slag inclusion formed by the air and the metal melt in the mold filling process is reduced or avoided;

(3) For example, CN108080601A, patent name: a casting device and a Chinese patent application of a casting method of low-pressure filling high-pressure solidification for a low-pressure increasing casting machine are disclosed, and the technical scheme of the patent application is summarized as follows: firstly, using low-pressure gas to make the metal melt in the heat-insulating furnace rise to a liquid lifting pipe, then pressurizing and filling the metal melt into a die cavity (the pressurizing gas is also in a low-pressure state), and finally using a flow dividing cone to seal the inlet of the die cavity, and using an independent pressurizing mechanism to pressurize and solidify the metal melt in the die cavity. The technical proposal is used for solving the defect of the (1) point;

(4) For example, CN105073302B, patent name: the technical scheme of the Chinese patent of the casting device is summarized as two parts: a first part: the timing control method is further adopted on the basis of the pressure difference between the normal positive pressurization and the vacuum depressurization, and specifically comprises the following steps: when the metal melt is filled into the cavity from the pressurizing chamber, the pressurizing unit pressurizes the gas in the pressurizing chamber until the metal melt reaches the opening of the cavity, after the metal melt reaches the opening of the cavity, the pressurizing in the pressurizing chamber is continued, and the depressurizing unit depressurizes the cavity, so that the splashing of the metal melt can be prevented to improve the quality of the product, and the second part: the technical scheme similar to the point (3) is adopted, namely, the gate sealing pin is pushed down to close the inlet of the die cavity, the die cavity stops to be depressurized, and the die cavity is pressurized by the central pressurizing pin and the local pressurizing pin.

Aiming at the technical schemes (2), (3) and (4), the casting defect analysis is as follows:

A. In the filling process, the inner part of the die cavity of the points (3) and (4) is still air, namely one end of the metal melt is still in contact with the air, and at the moment, the air in the die cavity generates risks of oxidation and gas coiling on the metal melt, so that the defects of inclusion and air holes in the workpiece manufactured at the points (3) and (4) are still caused. Meanwhile, if the technical scheme of the point (1) is directly applied to the points (3) and (4), namely, the die closed pressurized plenum chamber is directly arranged outside the technical schemes of the points (3) and (4), the manufacturing cost is greatly increased (the current casting device is huge, the arrangement is equivalent to that of directly arranging an inert gas sealing workshop), the operation and sealing difficulties are increased (equivalent to that of operating personnel outside the inert gas sealing workshop), and the exhaust time is overlong each time, so that the production efficiency is seriously influenced;

B. The points (1), (3) and (4) are between the filling process (namely the process of pushing the metal melt upwards into the die cavity by air pressure) and the process of closing the inlet of the die cavity, and because the metal melt is a viscous non-Newtonian fluid, larger friction resistance can be generated during the flowing process, so that the along-path pressure drop in the flowing process is large and the isobaric transmission can not be realized. Particularly, only low air pressure is adopted to push the metal melt (the air pressure is only 20MPa at maximum, and the air pressure of 20MPa is low), the push-up along-process pressure attenuation (the temperature freezing point of the metal melt is also lowered in the pressure attenuation process) is considered, the metal melt at the far end or in a thin runner of a die cavity is preferentially solidified and contracted due to small pressure, so that shrinkage defects are generated, and therefore, sufficient feeding cannot be realized by adopting the (1), (3) and (4), and the level of a die forging piece is difficult to reach;

C. and the points (3) and (4) are used for sealing the middle part of the die cavity through a split cone or a pushing down sprue sealing pin respectively in the process of sealing the inlet of the die cavity and pressurizing through hydraulic pressure so as to form hollow shaft, shell, frame or barrel parts in the middle, which are not suitable for parts with solid production centers and have the defect of narrow application range.

2. Common die forging (also known as squeeze casting) process defects:

A. Liquid die forging cannot avoid contact with outside air, so that no oxidization and no air-coiling filling cannot be realized;

B. Solid hot forging has the disadvantages of large material limitation and high cost.

Therefore, there is an urgent need in the market for a new hybrid casting device and process thereof, which can not only obtain the technological advantages of casting and die forging, but also overcome the technological disadvantages of casting and die forging.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a hybrid casting device and a process thereof, which solve the following problems: first: through the protective gas charging valve and the pressurizing chamber, molten metal is isolated from air in the casting process, the workpiece is formed without inclusion and air holes, and the protective gas charging valve has low manufacturing cost, simple operation and sealing and quick exhaust; second,: in the step S4 of the process, when the die cavity is full of the molten metal in the casting chamber, the feeding pressure head is pressed down at the same time, a certain hydraulic high pressure is applied to the molten metal in the die cavity in time, the molten metal at the far end or in a fine runner of the die cavity is ensured to be transferred at the same time to be changed into a liquid state to flow continuously when being in a semi-solid state, thereby realizing full shrinkage, and simultaneously being matched with the die forging pressure head to ensure that a workpiece reaches the level of a die forging piece; third,: the die cavity can be used for producing hollow shaft parts, shell parts, frame parts or barrel parts in the center, and meanwhile, one workpiece cavity in the die cavity can be used as a single and complete solid part for production and casting, so that the die cavity has a wide application range; fourth,: the invention not only overcomes the defects of the liquid forging and the solid hot forging, but also can produce the workpiece with the forging performance of the solid hot forging.

To achieve the above object, the present invention is achieved by the following two aspects:

In a first aspect, the invention provides a hybrid casting device, which comprises a workbench, a sprue bush arranged on the workbench, a lower die arranged on the top of the workbench, an upper die arranged opposite to the lower die, and a molten metal temperature regulating furnace arranged at the bottom of the workbench, wherein a die cavity is formed in the space between the lower die and the upper die, the middle part of the inner wall of the lower die is provided with a sprue communicated with the die cavity and the sprue bush respectively, the molten metal temperature regulating furnace comprises a pouring chamber communicated with the sprue bush, a pressurizing chamber arranged at one end of the pouring chamber and a first switch valve arranged between the pouring chamber and the pressurizing chamber, one end above the liquid level of molten metal in the pouring chamber is provided with a protective gas charging valve, the die cavity comprises a cavity, a workpiece cavity arranged at one end of the riser cavity, a die forging cavity arranged at the top of the workpiece cavity, and a feeding pressure head matched with the riser cavity of the die cavity and the sprue of the lower die respectively, and one side of the upper die is in sliding connection with a die forging pressure head matched with the die forging cavity.

Preferably, the feeding pressure head is of a stepped cylindrical structure with a large upper end diameter and a small lower end diameter, the upper end cylindrical structure of the feeding pressure head is matched with the riser cavity, and the lower end cylindrical structure of the feeding pressure head is matched with the gate of the lower die.

Preferably, a gas pressurizing valve is installed above the liquid surface of the molten metal in the pressurizing chamber.

Preferably, the molten metal temperature-regulating furnace further comprises an air brick assembly arranged at one end inside the liquid level of the molten metal in the casting chamber.

Preferably, the molten metal temperature-regulating furnace further comprises a liquid adding chamber arranged at one end of the pressurizing chamber and a second switch valve arranged between the pressurizing chamber and the liquid adding chamber.

In a second aspect, the present invention provides a hybrid casting process, for casting by a hybrid casting device as described above, comprising the steps of:

s1, regulating the temperature of molten metal in a molten metal temperature regulating furnace;

s2, closing the upper die and the lower die to form a die cavity;

S3, opening a protective gas charging valve, discharging air in the die cavity from the exhaust passage, and carrying out a blowing pretreatment process on molten metal in the casting chamber by the air brick assembly;

s4, opening a first switch valve and a gas pressurizing valve to enable molten metal in the casting chamber to fill the die cavity;

S5: the feeding oil cylinder drives the feeding pressure head to conduct ascending pressure descending, when the feeding pressure head enters a gate of the lower die, the gas pressurizing valve is used for pressure relief, molten metal in the pouring chamber falls back to be level with the liquid level of the pressurizing chamber, the feeding pressure head continues to descend, and the feeding pressure head is gradually pressurized and reaches a pressure stabilizing state;

S6, when the molten metal is solidified into a workpiece, the die forging cylinder drives the die forging press head to move downwards, and waste heat die forging is carried out on the workpiece;

S7, separating the upper die from the lower die, and taking out the workpiece.

Preferably, in the step S1, the molten metal in the molten metal temperature adjusting furnace is adjusted to be at a set casting temperature, wherein the casting temperature is 20-100 degrees celsius higher than the liquidus temperature of the molten metal.

Preferably, in the step S3, when the molten metal in the molten metal temperature-adjusting furnace is an aluminum alloy liquid, the inflation time of the protective gas inflation valve is in a range of 5 to 20 seconds, so that the protective gas sequentially passes through the sprue bush, the vent cavity, the workpiece cavity and the die forging cavity, and air in the die cavity is discharged from the vent passage, and the air brick assembly blows nitrogen or argon into the aluminum alloy liquid in the casting chamber, wherein the pressure range of the blown nitrogen or argon is in a range of 0.12 to 0.15MPa; when the molten metal in the molten metal temperature-adjusting furnace is magnesium alloy liquid, the inflation time range of the protective gas inflation valve is 5-20 seconds, so that the protective gas sequentially passes through the sprue bush, the vent cavity, the workpiece cavity and the die forging cavity, air in the die cavity is discharged from the exhaust passage, sulfur dioxide or carbon dioxide is blown into the magnesium alloy liquid in the casting chamber by the air brick assembly, and the pressure range of the blown sulfur dioxide or carbon dioxide is 0.12-0.15 MPa.

Preferably, in the step S5, when the feeding head enters the gate of the lower mold and continues to descend, the feeding head gradually pressurizes the molten metal in the tapping cavity and reaches a steady pressure set value, the steady pressure set value ranges from 21 to 80MPa, and the duration of the steady pressure set value ranges from 5 to 300 seconds.

Preferably, in the step S6, the forging specific pressure of the forging press to the workpiece is in the range of 150 to 200MPa.

Compared with the prior art, the invention has the beneficial effects that:

1. According to the mixed casting device and the process thereof, through the protective gas charging valve and the pressurizing chamber, the whole process of filling the die cavity with molten metal is not contacted with air, so that oxidation inclusion in the die cavity filling process is avoided, the manufacturing cost of the protective gas charging valve and the pressurizing chamber is low, the process is simple to operate, the required sealing treatment is simple, the exhaust process is rapid, and the production efficiency is effectively improved.

2. Meanwhile, the die cavity provided by the invention can be used for producing hollow shaft parts, shell parts, frame parts or barrel parts in a production center, and meanwhile, one workpiece cavity in the die cavity can be used as an independent and complete solid part for production casting, so that the die cavity has a wide application range.

3. The mixed casting device and the process thereof are novel casting technology, effectively solve the problems of small pressure and low workpiece forming quality in the existing casting technology, realize clean filling, high-pressure feeding and waste heat die forging, produce a metal structural member comparable with solid die forging, further reduce production energy consumption and improve product qualification rate.

4. The mixed casting process provided by the invention has the following advantages:

(1) The riser is directly connected with the gate, the temperature of the riser cavity is highest, the feeding efficiency is higher, the process yield can reach 75-90%, and the process yield is improved by about 1 time compared with liquid die forging;

(2) In the step S3, the grain structure of the molten metal is improved through a blowing pretreatment process, so that the fluidity of the molten metal is more excellent, the filling is more full, and the defects of incomplete cold insulation and filling are avoided;

(3) In the step S5, when the metal liquid in the casting chamber is filled in the die cavity, the feeding pressure head is pressed down in time, a certain hydraulic high pressure is applied to the metal liquid in the die cavity in time, the constant high pressure transmission is ensured when the metal melt at the far end or in a fine runner of the die cavity is in a semi-solid state, and the metal melt is changed into a liquid state to flow continuously, so that the full shrinkage is realized;

(4) Simultaneously, the die forging pressure head performs waste heat die forging, so that the workpiece is ensured to reach the die forging level, and secondary heating is omitted;

(5) The process cost is low. The device mold locking force applied to the hybrid casting device is obviously reduced due to the ingenious different time corresponding to different pressurizing methods, so that a workpiece with larger width can be prepared.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a hybrid casting apparatus and process for evacuating a mold cavity and pretreating molten metal according to the present invention;

FIG. 2 is a schematic diagram of a hybrid casting apparatus and a process thereof for performing a gas-pressure tight casting process according to the present invention;

FIG. 3 is a schematic illustration of a hybrid casting apparatus and process for incremental pressure feed in accordance with the present invention;

fig. 4 is a schematic structural diagram of a hybrid casting device and a process thereof for performing waste heat die forging treatment.

The drawings include:

1. A mold cavity; 10. a gate; 100. a parting surface; 11. a lower die; 12. an upper die; 1A, riser cavity; 1B, a workpiece cavity; 1C, exhausting channels; 1D, die forging cavity; 2. a work table; 3. a sprue bush; 4. a protective gas charging valve; 5. an air brick assembly; 6. a gas pressurization valve; 7. a molten metal temperature regulating furnace; 7A, a casting chamber; 7B, a pressurizing chamber; 7C, a liquid adding chamber; 7D, a second switch valve; 7E, a first switch valve; 8. feeding a pressure head; 81. feeding an oil cylinder; 82. a die forging oil cylinder; 8A, an upper cylindrical structure; 8B, a lower cylindrical structure; 9. and (5) die forging a press head.

Detailed Description

The technical solutions of the present embodiment of the present invention will be clearly and completely described below with reference to the drawings in the present embodiment of the present invention, and it is apparent that the described present embodiment is one embodiment of the present invention, but not all the present embodiments. All other embodiments, which can be made by those skilled in the art without making any inventive effort, are intended to be within the scope of the present invention.

Embodiment one:

Referring to fig. 1 to 4, an embodiment of the present invention provides a hybrid casting device, including a workbench 2, a sprue bush 3 installed on the workbench 2, a lower mold 11 installed on the top of the workbench 2, an upper mold 12 opposite to the lower mold 11, and a metal liquid temperature adjusting furnace 7 installed on the bottom of the workbench 2, a cavity 1 is formed in the interior between the lower mold 11 and the upper mold 12, a sprue 10 respectively communicating with the cavity 1 and the sprue bush 3 is provided in the middle of the inner wall of the lower mold 11, the metal liquid temperature adjusting furnace 7 includes a pouring chamber 7A communicating with the sprue bush 3, a pressurizing chamber 7B installed at one end of the pouring chamber 7A, and a first switching valve 7E installed between the pouring chamber 7A and the pressurizing chamber 7B, a protective gas charging valve 4 is provided at one end above the liquid level of the metal liquid in the pouring chamber 7A, the cavity 1 includes a cavity 1A, a workpiece cavity 1B provided at one end of the riser cavity 1A, a die forging cavity 1D installed on the top of the workpiece cavity 1B, and a middle part 12C installed at one end of the workpiece cavity 1B, and a die forging cavity 1C slidably connected with the cavity 1D is provided with the cavity 1B, and the die forging cavity 1 is slidably connected with the cavity 10D, and the die forging cavity 1 is slidably matched with the cavity 10 is provided at one side of the cavity 1.

Meanwhile, the die cavity 1 of the hybrid casting device has two specific embodiments:

Firstly, the die cavity 1 is used for producing hollow shaft, shell, frame or barrel parts in the center, and the molding position of a gate 10 between the top of a sprue bush 3 and a feeding pressure head 8 is the hollow position of the die cavity 1;

Secondly, the die cavity 1 is composed of a riser cavity 1A, a workpiece cavity 1B, an exhaust passage 1C and a die forging cavity 1D at one end of the feeding head 8, one die cavity 1 can be arranged, two die cavities can be symmetrically arranged relative to the feeding head 8, a plurality of die cavities can be arranged annularly relative to the feeding head 8, the die cavity 1 can be used for single complete solid parts, and molten metal is obtained by the die cavity 1 through a gate 10 at one end of the die cavity.

The feeding pressure head 8 is of a stepped cylindrical structure with a large upper end diameter and a small lower end diameter, the upper end cylindrical structure 8A of the feeding pressure head 8 is matched with the riser cavity 1A, and the lower end cylindrical structure 8B of the feeding pressure head 8 is matched with the gate 10 of the lower die 11.

The forging die pressing head is of a circular or special-shaped section and is consistent with the shape of the top surface of a workpiece to be die forged.

A gas pressurizing valve 6 is installed above the liquid surface of the molten metal in the pressurizing chamber 7B, and the gas pressurizing valve 6 functions in: when the first on-off valve 7E is opened, the pressurizing chamber 7B communicates with the pouring chamber 7A, and the gas pressurizing valve 6 pressurizes the molten metal in the pouring chamber 7A, thereby pushing the molten metal upward into the cavity 1.

The molten metal temperature-adjusting furnace 7 further comprises an air brick assembly 5 arranged at one end inside the liquid surface of the molten metal in the casting chamber 7A. The air brick assembly 5 has a one-way valve structure, namely, only one-way blowing can be carried out in the pouring chamber 7A, but molten metal cannot enter the air brick assembly 5.

The molten metal temperature-adjusting furnace 7 further includes a liquid charging chamber 7C provided at one end of the pressurizing chamber 7B, and a second switching valve 7D provided between the pressurizing chamber 7B and the liquid charging chamber 7C. When the liquid level of the metal liquid in the pressurizing chamber 7B and the pouring chamber 7A is too low, the second switch valve 7D is opened, the metal liquid can be timely supplemented for the pressurizing chamber 7B and the pouring chamber 7A through the liquid adding chamber 7C, and a switch cover for adding the liquid is arranged above the liquid adding chamber 7C.

A feeding oil cylinder 81 for driving the feeding pressure head 8 to reciprocate is arranged at the top of the feeding pressure head 8, and a die forging oil cylinder 82 for driving the die forging pressure head 9 to reciprocate is arranged at the top of the die forging pressure head 9.

The exhaust passage 1C is provided at the end of the parting plane 100 between the upper die 12 and the lower die 11, and the exhaust passage 1C is fitted with the shielding gas charging valve 4.

In addition, the embodiment of the invention provides a mixed casting device, which further comprises the following mechanism: a host, an air pressure regulation system, and a high pressure mold locking assembly (these mechanisms are prior art and are not shown in the drawings). The main machine consists of a frame, a vertical guide rail or guide post, a workbench 2 and a movable cross beam, wherein the frame is used for supporting the whole main machine and is positioned below the workbench 2, and a placing space of a molten metal temperature regulating furnace 7 is reserved between support posts on the frame; the workbench 2 is fixed at the top end of the frame, and is kept horizontal, vertical guide rails or guide columns are respectively arranged on four corners of the workbench 2, a sprue bush 3 arranged in the center of the workbench 2 is made of heat-resistant die steel, and a T-shaped groove for installing a lower die 11 is formed in the upper surface of the workbench 2; the vertical guide rail or the guide post is fixed on the workbench 2, the movable cross beam passes through the workbench, and a section of annular screw thread is arranged at a height position 500-1100 mm away from the surface of the workbench 2 and is used for matching with the high-pressure locking module to lock the die; the length of the annular screw thread section is 200-300 mm so as to adapt to different closing heights of the upper die and the lower die; the movable cross beam can move up and down along the vertical guide post, and the movement travel is 300-1000 mm; the lower plane of the movable beam is provided with a T-shaped groove for installing the upper die 12, and a material beating oil cylinder, a die forging oil cylinder 82 and a feeding oil cylinder 81 are arranged on the movable beam; the feeding oil cylinder 81 of the device is positioned at the center of the movable cross beam, the stroke is 100-200 mm, and the cylinder force is 600-6000 kN; the material beating cylinders are arranged at the periphery of the feeding cylinder 81, the number of the material beating cylinders is 2-4, the stroke is 20-200 mm, and the cylinder force is 150-1000 kN; the die forging oil cylinder 82 has the stroke of 10-100 mm, the cylinder force of 600-6000 kN and the number of 2-6, is arranged in a central symmetry way, the position of the die forging oil cylinder can be adjusted, the adjustment amount is 20-100 mm, and the die forging oil cylinder is arranged at the outer side of the material beating oil cylinder; a through hole with the diameter of 100-300 mm is arranged in the center of the movable cross beam for the piston rod of the feeding cylinder 81 or the connecting rod of the feeding pressure head 8 to pass through; the high-pressure locking module comprises a copper sleeve, a locking high-pressure cylinder module and a rear locking module, and is arranged around the movable cross beam and is perpendicular to the vertical guide post or the guide rail; an oil storage tank is designed on the inner side of the copper bush, so that friction between the copper bush and the guide post is reduced; the copper sleeve is arranged on the copper sleeve seat, and the front end of the copper sleeve is provided with a dust seal; when the dust seal moves up and down on the movable cross beam, the release agent, the oil sludge and other foreign matters on the surface of the guide post are scraped off, so that the foreign matters are prevented from entering the gap between the copper bush and the movable cross beam, and the guide post and the copper bush are prevented from being damaged by pulling; the rear lock assembly consists of a rear lock edge opening nut and a rear lock oil cylinder, wherein the edge opening nut is provided with annular screw teeth which are matched with the annular screw teeth on the guide post; the cylinder body of the die locking high-pressure cylinder is fixed on the movable cross beam, the front end of the piston rod of the die locking high-pressure cylinder is not fixed with the movable cross beam, a rear locking assembly is arranged at the rear end of the piston rod, when a rear locking cylinder pushes a rear locking edge opening nut to be closed, the rear locking edge opening nut and a guide pillar are in interlocking relation, the rear locking edge opening nut and the guide pillar are equivalent to hard connection, at the moment, the die locking high-pressure cylinder starts to start to press, and the piston rod of the die locking high-pressure cylinder and the guide pillar are locked through the edge opening nut, so that the cylinder body is pushed to move downwards by oil pressure until the die parting surface 100 is completely attached, and the die locking high-pressure cylinder continuously pressurizes, so that die locking force is generated. The molten metal temperature regulating furnace 7 is a gas furnace or an electric furnace, is positioned below or beside the main machine workbench 2, and also comprises a thermocouple temperature control system, a lifting mechanism and a horizontal movement mechanism; the thermocouple temperature control system can carry out real-time closed-loop regulation and control on the temperature of the molten metal; the pouring chamber 7A, the pressurizing chamber 7B and the liquid storage chamber are divided by a fireproof partition wall, and the three chambers form a hearth; a protective gas charging valve 4 on the pouring chamber 7A, when the pressure of the die cavity 1 exceeds 1 atmosphere (0.1 MPa), the protective gas charging valve 4 is opened to ventilate into the pouring chamber 7A, and when the pressure is less than 1 atmosphere, the protective gas charging valve is automatically closed to prevent molten metal and gas from escaping; the lifting mechanism drives the molten metal temperature-regulating furnace 7 to vertically lift by 20-100 mm, so as to realize the attaching sealing and separating with the workbench 2; the horizontal movement mechanism drives the molten metal temperature-regulating furnace 7 to horizontally move along a horizontal track, and the movement stroke is 1000-5000 mm; the air pressure control system comprises an air source, a valve group and an electrical control system; the pressure is 3-8 MPa; the valve group comprises a stop valve, a proportional valve and an electromagnetic valve; the control system is PLC control. The air pressure control system can respectively provide air sources for the air pressurization valve 6, the air brick assembly 5 and the protective air charging valve 4.

Embodiment two:

Referring to fig. 1 to 4, an embodiment of the present invention provides a hybrid casting process, which is performed by a hybrid casting apparatus as in embodiment 1, and meanwhile, the molten metal cast in the second embodiment is aluminum alloy liquid, and the air source provided by the air pressure control system in the second embodiment is nitrogen, that is, the air source provided by the air pressure valve 6, the air brick assembly 5 and the protective air charging valve 4 is nitrogen, wherein the air pressure control system may also provide argon for the air brick assembly 5, and the specific process of the hybrid casting process is explained in detail with the aluminum alloy liquid as a focus, and specifically includes the following steps:

s1, aluminum alloy liquid temperature adjustment: the temperature of the aluminum alloy liquid in the metal liquid temperature adjusting furnace 7 is adjusted;

Specifically, the aluminum alloy liquid in the molten metal temperature-regulating furnace 7 is subjected to temperature regulation and is kept at a set casting temperature, wherein the casting temperature is 20-100 ℃ higher than the liquidus temperature of the aluminum alloy.

S2, die closing and die locking: starting a host machine, enabling a movable cross beam to descend, closing an upper die 12 and a lower die 11, starting a high-pressure die locking assembly, enabling the upper die 12 and the lower die 11 to be locked, enabling a feeding pressure head 8 and a die forging pressure head 9 to be located at initial positions, and enabling a riser cavity 1A, a workpiece cavity 1B, an exhaust passage 1C and a die forging cavity 1D of a die cavity 1 to be formed;

s3, evacuating the die cavity 1 and preprocessing aluminum alloy liquid: opening a protective gas charging valve 4 to discharge air in the die cavity 1 from the exhaust passage 1C, and carrying out a blowing pretreatment process on aluminum alloy liquid in the casting chamber 7A by the air brick assembly 5;

Specifically, the first switch valve 7E between the pouring chamber 7A and the pressurizing chamber 7B is closed, the protective gas charging valve 4 is opened, and the air is charged above the liquid level of the aluminum alloy liquid in the pouring chamber 7A for 5-20 seconds, so that the protective gas sequentially passes through the sprue bush 3, the riser cavity 1A, the workpiece cavity 1B and the die forging cavity 1D, the air in the die cavity 1 is discharged from the exhaust passage 1C, the die cavity 1 is filled with the protective gas, and meanwhile, the air brick assembly 5 blows nitrogen or argon into the aluminum alloy liquid in the pouring chamber 7A, and the pressure range of the blown nitrogen or argon is 0.12-0.15 MPa. The advantages of introducing nitrogen or argon into the aluminum alloy liquid are that: the grain structure of the aluminum alloy liquid is improved, so that the internal molecules of the aluminum alloy liquid are tighter, and the fluidity of the aluminum alloy liquid is more excellent, so that filling is more full, and the defects of incomplete cold insulation and filling are avoided;

S4, air pressure sealing pouring: opening the first switch valve 7E and the gas pressurizing valve 6 to enable the aluminum alloy liquid in the pouring chamber 7A to fill the die cavity 1;

Wherein, the pressure range of the air blown out by the air pressurizing valve 6 is 0.1-0.6 MPa, the air pressurizing valve 6 has the function of pushing the aluminum alloy liquid in the pouring chamber 7A into the sprue bush 3, the riser cavity 1A, the workpiece cavity 1B and the die forging cavity 1D until the casting chamber is full;

s5: incremental pressure feeding: after the die cavity 1 is full, the feeding oil cylinder 81 drives the feeding pressure head 8 to gradually increase the pressure to descend, when the feeding pressure head 8 enters the gate 10 of the lower die 11, the gas pressurizing valve 6 is used for pressure relief, the aluminum alloy liquid in the pouring chamber 7A falls back to be level with the liquid level in the pressurizing chamber 7B, and the feeding pressure head 8 continuously descends to gradually pressurize and reach a pressure stabilizing state;

In the process of gradually pressurizing and reaching a pressure stabilizing state, the feeding pressure head 8 enters the gate 10 of the lower die 11 and continuously descends, the feeding pressure head 8 gradually pressurizes the aluminum alloy liquid in the riser cavity 1A and reaches a stable pressure set value, the range of the stable pressure set value is 21-80 MPa, and the duration range of the stable pressure set value is 5-300 seconds;

Specifically, when the feeding ram 8 enters the gate 10 of the lower mold 11 and continues to descend, the aluminum alloy liquid in the cavity-off chamber 1A is pressurized by the connection surface between the upper end cylindrical structure 8A and the lower end cylindrical structure 8B of the feeding ram 8, the surface of the lower end cylindrical structure 8B, and/or the surface of the upper end cylindrical structure 8A;

the step S5 has the following functions: when the die cavity 1 is full of the aluminum alloy liquid in the casting chamber 7A, the feeding pressure head 8 can timely press down, and a certain hydraulic high pressure is timely applied to the aluminum alloy liquid in the die cavity 1, so that the molten metal at the far end or in a thin runner of the die cavity 1 is ensured to be transferred to be changed into a liquid state to flow continuously when in a semi-solid state, and the full shrinkage is realized;

S6, waste heat die forging: when the aluminum alloy liquid is solidified into a workpiece, the die forging cylinder 82 drives the die forging press head 9 to move downwards, and the workpiece is subjected to waste heat die forging;

Wherein, the forging specific pressure range of the die forging press head 9 to the workpiece is 150-200 MPa, and meanwhile, a user can set a certain plastic deformation set value, for example, when the workpiece compression ratio reaches (the ratio of the height before compression to the height after compression) 1.1-1.5, the die forging oil cylinder 82, the feeding oil cylinder 81 and the die locking oil cylinder are subjected to pressure relief reset;

s7, opening the die and taking out the part: the upper die 12 and the lower die 11 are separated by the die opening oil cylinder, and the top plate and the top rod are pushed by the top piece oil cylinder to eject the workpiece.

The mixed casting process of the embodiment of the invention effectively solves the problems of low pressure and low workpiece forming quality of the prior casting technology, realizes clean filling, high-pressure feeding and waste heat die forging, produces a metal structural member comparable with solid die forging, further reduces production energy consumption and improves product qualification rate.

Wherein, the forging quality of the workpiece cast by the mixed casting process of the embodiment of the invention is respectively compared with the quality of the workpiece manufactured by low-pressure casting and liquid die forging, and the following table I is obtained:

The table is shown below:

embodiment III:

The embodiment of the present invention provides a hybrid casting process, which is cast by a hybrid casting apparatus as in embodiment 1, and meanwhile, the molten metal cast in embodiment three is a magnesium alloy liquid, so that the difference between the embodiment three and the embodiment two is only that the types of the molten metal to be treated are different, the air sources in the air pressure control system are different, and some process steps related to the air source control are different, and other settings are the same, and the difference points of embodiment three are specifically:

the cast molten metal in the third embodiment is magnesium alloy liquid;

The air source provided by the air pressure control system of the third embodiment is sulfur dioxide or carbon dioxide, namely, the air introduced by the air pressurization valve 6, the air brick assembly 5 and the protective air charging valve 4 is sulfur dioxide or carbon dioxide;

a hybrid casting process according to the third embodiment, wherein,

In step S3, the cavity 1 is evacuated and the magnesium alloy liquid is pretreated: opening a protective gas charging valve 4, discharging air in the die cavity 1 from the exhaust passage 1C, opening an air brick assembly 5, and performing a blowing pretreatment process on the magnesium alloy liquid in the casting chamber 7A;

Specifically, a first switch valve 7E between the pouring chamber 7A and the pressurizing chamber 7B is closed firstly, a protective gas charging valve 4 is opened, the upper part of the liquid level of the magnesium alloy liquid in the pouring chamber 7A is charged with gas for 5-20 seconds, so that the protective gas sequentially passes through the sprue bush 3, the riser cavity 1A, the workpiece cavity 1B and the die forging cavity 1D, air in the die cavity 1 is discharged from the exhaust passage 1C, the die cavity 1 is filled with the protective gas, meanwhile, the air brick assembly 5 blows sulfur dioxide and carbon dioxide into the magnesium alloy liquid in the pouring chamber 7A, and the pressure range of the blown sulfur dioxide and carbon dioxide is 0.12-0.15 MPa.

The foregoing is only illustrative of the preferred embodiments of the present invention and is not to be construed as limiting the invention, but rather as various modifications, equivalent arrangements, improvements, etc., within the spirit and principles of the present invention.

Claims (10)

1. The utility model provides a hybrid casting device, includes workstation (2), its characterized in that still includes gate cover (3) of installing on workstation (2), installs lower mould (11) at workstation (2) top, upper mould (12) and the molten metal temperature regulating stove (7) of installing in workstation (2) bottom that set up relatively with lower mould (11), the inside between lower mould (11) and upper mould (12) is formed with die cavity (1), be equipped with runner (10) that are linked together with die cavity (1), gate cover (3) respectively in the middle part of the inner wall of lower mould (11), molten metal temperature regulating stove (7) include pouring chamber (7A) that are linked together with gate cover (3), install in pressurizing chamber (7B) of pouring chamber (7A) one end and install in first switching valve (7E) between pouring chamber (7A) and pressurizing chamber (7B), the liquid level top one end of the molten metal inside pouring chamber (7A) is provided with protection gas valve (4), die cavity (1) include establish in die cavity (1) and install in die cavity (1) top cavity (1) and work piece (1) one end die forging (1) C and work piece cavity (1) one end (1) are installed at the top of work piece (1C) and work piece cavity (1) C, the middle part of the upper die (12) is slidably connected with a feeding pressure head (8) which is matched with a riser cavity (1A) of the die cavity (1) and a gate (10) of the lower die (11), and one side of the upper die (12) is slidably connected with a die forging pressure head (9) which is matched with the die forging cavity (1D).

2. A hybrid casting device according to claim 1, wherein the feeding head (8) has a stepped cylindrical structure with a large upper diameter and a small lower diameter, the upper cylindrical structure (8A) of the feeding head (8) is matched with the riser cavity (1A), and the lower cylindrical structure (8B) of the feeding head (8) is matched with the gate (10) of the lower mold (11).

3. A hybrid casting apparatus according to claim 1, characterized in that a gas pressurizing valve (6) is provided above the liquid level of the molten metal in the pressurizing chamber (7B).

4. A hybrid casting apparatus according to claim 1, wherein the molten metal temperature adjusting furnace (7) further comprises an air brick assembly (5) provided at one end inside the liquid surface of the molten metal inside the casting chamber (7A).

5. A hybrid casting apparatus according to claim 1, wherein the molten metal temperature-regulating furnace (7) further comprises a charging chamber (7C) provided at one end of the pressurizing chamber (7B) and a second switching valve (7D) provided between the pressurizing chamber (7B) and the charging chamber (7C).

6. A hybrid casting process characterized by casting by a hybrid casting apparatus according to any one of claims 1 to 5, comprising the steps of:

s1, regulating the temperature of molten metal in a molten metal temperature regulating furnace (7);

s2, closing the upper die (12) and the lower die (11) to form a die cavity (1);

s3, opening a protective gas charging valve (4) to discharge air in the die cavity (1) from the exhaust passage (1C), and carrying out a blowing pretreatment process on molten metal in the casting chamber (7A) by the air brick assembly (5);

s4, opening a first switch valve (7E) and a gas pressurizing valve (6) to enable molten metal in the pouring chamber (7A) to fill the die cavity (1);

S5: the feeding oil cylinder (81) drives the feeding pressure head (8) to gradually increase the pressure downwards, when the feeding pressure head (8) enters a gate (10) of the lower die (11), the gas pressurizing valve (6) is used for releasing pressure, the metal liquid in the pouring chamber (7A) falls back to be level with the liquid level of the pressurizing chamber (7B), the feeding pressure head (8) continues to downwards, and the feeding pressure head is gradually pressurized and reaches a pressure stabilizing state;

s6, when the molten metal is solidified into a workpiece, the die forging oil cylinder (82) drives the die forging pressure head (9) to move downwards, and waste heat die forging is carried out on the workpiece;

s7, separating the upper die (12) from the lower die (11), and taking out the workpiece.

7. A hybrid casting process according to claim 6, wherein in said step S1, the molten metal in the molten metal temperature adjusting furnace (7) is adjusted to a set casting temperature in a range of 20 to 100 degrees celsius above the liquidus temperature of the metal.

8. The hybrid casting process according to claim 6, wherein in the step S3, when the molten metal in the molten metal temperature adjusting furnace (7) is an aluminum alloy liquid, the inflation time of the shielding gas inflation valve (4) is in the range of 5 to 20 seconds, so that the shielding gas sequentially passes through the sprue bush (3), the riser cavity (1A), the workpiece cavity (1B) and the die forging cavity (1D), thereby discharging air in the die cavity (1) from the exhaust passage (1C), and the air brick assembly (5) blows nitrogen or argon into the aluminum alloy liquid in the casting chamber (7A) in the pressure range of 0.12 to 0.15MPa; when the molten metal in the molten metal temperature-regulating furnace (7) is magnesium alloy liquid, the inflation time range of the protective gas inflation valve (4) is 5-20 seconds, so that the protective gas sequentially passes through the sprue bush (3), the riser cavity (1A), the workpiece cavity (1B) and the die forging cavity (1D), air in the die cavity (1) is discharged from the exhaust passage (1C), and the air brick assembly (5) blows sulfur dioxide or carbon dioxide into the magnesium alloy liquid in the casting chamber (7A), wherein the pressure range of the blown sulfur dioxide or carbon dioxide is 0.12-0.15 MPa.

9. A hybrid casting process according to claim 6, characterized in that in said step S5, when the feeding head (8) enters the gate (10) of the lower mold (11) and continues to descend, the feeding head (8) gradually pressurizes the molten metal in the riser cavity (1A) and reaches a steady pressure set value ranging from 21 to 80MPa and a duration of the steady pressure set value ranging from 5 to 300 seconds.

10. A hybrid casting process according to claim 6, characterized in that in said step S6, the forging specific pressure of the swage head (9) against the workpiece is in the range of 150 to 200MPa.