A motor rotor squirrel cage low-pressure copper casting equipment and copper casting method

Abstract

The present invention belongs to the technical field of metal casting, and specifically is a motor rotor squirrel cage low-pressure copper casting equipment and a copper casting method thereof, comprising a shell, a liquid inlet unit, a space control unit and a mold unit; the mold unit comprises a bottom plate, a center column, a clamping plate and a top cover; the bottom plate is fixedly connected to the bottom of the shell, a No. 1 groove is provided at the upper part of the bottom plate, and the liquid inlet passes through the bottom plate; the center column is fixedly connected to the center of the bottom plate; a plurality of clamping plates are evenly arranged at the upper part of the bottom plate, and the clamping plates surround the center column, the clamping plates are all provided with baffles, and cavities are provided at the corresponding parts of the baffles, a plurality of extrusion blocks are evenly arranged at the circular arc parts of the clamping plates, the ends of the extrusion blocks are circular arc-shaped, the baffles are slidably connected to the cavities, and the baffles and the cavities are both arc-shaped; the top of the center column is slidably connected to the top cover.

Description

Technical Field

[0001] The invention relates to the technical field of metal casting, in particular to a motor rotor squirrel cage low-pressure copper casting device and a copper casting method thereof. Background Art

[0002] In the manufacturing process of traditional motor rotors, multiple stacked rotor silicon steel sheets need to be fixed together by using ribs in the rotor guide slots, or cast aluminum is used to fix the rotor instead of ribs. However, since the use of cast aluminum to manufacture rotors has low motor efficiency and there is no better manufacturing process for other materials, cast copper will have defects such as empty nests and incomplete filling, and it cannot be used in practice.

[0003] There is also an invention in the prior art about a motor rotor squirrel cage low-pressure copper casting equipment and a copper casting method thereof. For example, a Chinese patent with application number CN201721316635.8 discloses a motor rotor squirrel cage low-pressure copper casting equipment including a copper melting furnace, a rotor copper casting mold, and a casting press provided with the mold. A pressurizing furnace is arranged between the copper melting furnace and the casting press, and the copper melting furnace and the pressurizing furnace are connected by a deoxidation pipeline. A vacuum gate is arranged at the connection part between the deoxidation pipeline and the pressurizing furnace. The pressurizing furnace is connected to the pressurizing equipment via a liquid flow channel, and a vacuum equipment is arranged on the liquid flow channel. A conductive agent feeding device and a mixing device are arranged between the mold and the liquid flow channel. A controller is arranged in the motor rotor squirrel cage low-pressure copper casting equipment; the flow rate of the copper liquid can be well controlled, the control accuracy of copper casting can be improved, the waste of the copper liquid 11a can be reduced, and the yield rate of the product can be improved. By using the present invention, it is possible to improve production efficiency, reduce labor intensity, ensure the insulation effect between silicon steel sheets, and more importantly, it is possible to improve the conductivity of the rotor 10 ribs, further improving the efficiency of the motor. However, the above patent still has defects. The patent does not design the exhaust inside the mold. Although the air is extracted from the mold part during use, when the molten copper is squeezed into the mold, the residual gas will still be squeezed into the mold, so that it cannot be completely guaranteed that the molten copper is filled in the mold during the casting process, which has an adverse effect on the casting effect.

[0004] In view of this, the present invention solves the above technical problems by proposing a motor rotor squirrel cage low-pressure copper casting equipment and a copper casting method thereof. Summary of the invention

[0005] In order to make up for the shortcomings of the existing technology and solve the problem of empty nests and underfilling in the existing motor rotor cage low-pressure copper casting equipment during casting, the yield rate of the motor rotor cage low-pressure copper casting is low, the casting efficiency is low, and the production efficiency of chrome-free tinplate is affected.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a motor rotor cage copper casting method according to the present invention comprises the following steps:

[0007] S1: The copper melting chamber is heated to melt the solid copper into a molten state, and then a low-pressure compressed gas with a pressure of 0.06-0.15MPa is filled in through the air inlet. As the gas accumulates on the upper part of the copper melting chamber, the molten copper gradually fills from the bottom of the bottom plate to the top of the extrusion block; at this time, the top cover is not squeezed by the clamping plate and is tightly attached to form a seal, so the air inside the mold cavity is gradually pushed out from the upper part of the mold cavity by the molten copper;

[0008] S2: The telescopic rod is gradually extended so that the clamping block squeezes the clamping plate under the drive of the telescopic rod, so that the clamping plate squeezes the space in the mold cavity, and the space is gradually reduced; and at the same time, the mold cavity is not filled due to the poor fluidity of the copper liquid, and the air inside is destroyed; and under the squeezing of the clamping plate, the air is discharged from the upper part of the mold cavity that has not been sealed temporarily; at the same time, the outer wall surface of the top cover is also completely fitted with the inner wall surface of the clamping plate to form a seal; the casting discharges the internal air and forms a sealed casting environment;

[0009] S3: The baffle plate provided on the clamping plate gradually moves into the cavity inside the clamping plate, that is, the guide rod gradually moves; and because the upper surface of the guide rod is provided obliquely, as the guide rod gradually moves, the sliding rod is gradually lifted up; as the sliding rod is gradually lifted up, the upper end of the sliding rod rises, and under the action of the No. 1 rod, the top cover is subjected to a downward pressure;

[0010] S4: The middle part of the sliding rod is a piston plate, and the internal sealing of the cavity is strong. As the pressure increases, the upward pressure on the sliding rod gradually increases; the end of the sliding rod is subjected to an upward force under the action of pressure; under the action of rod No. 1, the top cover is subjected to a greater force, which further squeezes the molten copper and strengthens the squeezing effect; after the casting is completed, the casting is taken out for grinding.

[0011] A motor rotor squirrel cage low-pressure copper casting equipment, the motor rotor squirrel cage low-pressure copper casting equipment is suitable for the above-mentioned copper casting method, the motor rotor squirrel cage low-pressure copper casting equipment comprises a shell, a liquid inlet unit, a space control unit and a mold unit; the liquid inlet unit comprises a copper melting chamber, an air inlet and a liquid outlet; the copper melting chamber is fixedly connected to the lower part of the shell, and a heating device is arranged in the copper melting chamber; the air inlet is fixedly connected to and passes through the right side wall of the copper melting chamber, and the air inlet is connected to the outside; the space control unit comprises a telescopic rod and a clamping block, the telescopic rod is fixedly connected to the two side walls of the shell, the clamping block is fixedly connected to the end of the telescopic rod, and the clamping block is an arc plate; The mold unit includes a base plate, a center column, a clamping plate and a top cover; the base plate is fixedly connected to the bottom of the shell, a No. 1 groove is provided at the upper part of the base plate, and the liquid outlet passes through the No. 1 groove; the center column is fixedly connected to the center of the base plate; a plurality of clamping plates are slidably connected to the upper part of the base plate, the clamping plates are all fixedly connected to baffles, and cavities are provided at the corresponding parts of the baffles of two adjacent clamping plates, and the ends of the baffles extend into the cavities; a plurality of extrusion blocks are evenly provided on the surface of the clamping plate close to the center column, the end surface of the extrusion block close to the center column is arc-shaped, the baffle is slidably connected to the cavity, and the baffle and the cavity are both arc-shaped; the upper part of the center column is slidably connected to the top cover.

[0012] During operation, the copper melting chamber is heated to melt the solid copper metal into a molten state, and then low-pressure compressed gas with a pressure of 0.06-0.15MPa is filled in through the air inlet. As the gas accumulates in the upper part of the copper melting chamber, the molten copper in the copper melting chamber is squeezed through the liquid outlet into the mold cavity surrounded by the clamping plate and the baffle, and the molten copper gradually fills up from the bottom of the bottom plate to the top of the extrusion block; in this process, the clamping block is not completely squeezed by the telescopic rod, so the top cover is not squeezed by the clamping plate and tightly attached to the mold cavity, resulting in the internal sealing of the mold cavity, so the air inside the mold cavity is gradually pushed out from the upper part of the mold cavity by the molten copper, reducing the air in the mold cavity and ensuring that the casting will not be caused by the residual air inside An empty nest appears; at the same time, as the molten copper gradually fills the mold cavity; the telescopic rod gradually extends, so that the clamping block squeezes the splint under the drive of the telescopic rod, and the splint squeezes the space in the mold cavity, causing the space to gradually shrink; and destroys the condition where the mold cavity is not filled due to the poor fluidity of the molten copper, resulting in the presence of air inside; under the squeezing of the splint, the air is discharged from the upper part of the mold cavity that has not been sealed temporarily; as the telescopic rod continues to move, the end of the extrusion block on the inner side of the splint gradually approaches the center column, and finally completely fits with the surface of the center column, and at the same time, the outer wall of the top cover also completely fits with the inner wall of the splint to form a seal; the mold cavity is discharged from the internal air and a sealed casting environment is formed.

[0013] Preferably, the baffle is fixedly connected to the guide rod on the side wall inside the cavity, the upper surface of the guide rod is obliquely arranged, the upper part of the splint is provided with a through hole penetrating the splint, and the sliding rod is slidably connected inside the through hole; the lower end of the sliding rod is slidably connected to the upper end of the guide rod, the upper end of the sliding rod is rotatably connected to one end of the No. 1 rod, the other end of the No. 1 rod is slidably connected to the top cover, the middle part of the No. 1 rod is rotatably connected to the top column, and the top column is fixed to the upper surface of the splint.

[0014] During operation, when the molten copper is about to fill the mold cavity, the lower end of the sliding rod contacts the upper end of the guide rod, and as the telescopic rod drives the clamping block, the clamping block squeezes the clamping plate to approach the central column; the baffle arranged on the clamping plate gradually moves into the cavity inside the clamping plate, that is, the guide rod gradually moves; and because the upper surface of the guide rod is arranged obliquely, as the guide rod gradually moves, the sliding rod is gradually lifted up; as the sliding rod is gradually lifted up, the upper end of the sliding rod rises, that is, the connection part between the No. 1 rod and the upper end of the sliding rod rises, so that the top cover is subjected to a downward pressure under the action of the other end of the No. 1 rod; the molten copper in the mold cavity is further compressed, and the air in the mold cavity is further reduced to prevent the casting from being empty and not filled.

[0015] Preferably, the pressure in the inner space of the cavity is relatively high; and a piston plate is provided in the middle of the sliding rod.

[0016] During operation, when the splint gradually approaches the center column, the baffle will gradually move into the cavity. As the baffle gradually moves into the cavity, the pressure inside the cavity gradually increases. Because a piston plate is provided in the middle part of the sliding rod and the cavity is tightly sealed, as the pressure increases, the upward force on the sliding rod also gradually increases, so that the end of the sliding rod is subjected to an upward force. Under the action of rod No. 1, the top cover is subjected to a greater force, which further squeezes the molten copper, thereby strengthening the squeezing effect and further preventing the casting from being empty or underfilled.

[0017] Preferably, the No. 1 rod portion at the connection between the sliding rod and the top column is longer, and the No. 1 rod portion at the connection between the top cover and the top column is shorter.

[0018] During operation, as the guide rod and the sliding rod move, the sliding rod is gradually lifted up. As the sliding rod is gradually lifted up, the position where the top column and the No. 1 rod are rotatably connected serves as a fulcrum, and the No. 1 rod gradually tilts. As the sliding rod rises, the end of the top cover is subjected to a downward force, and the force increases as the height of the sliding rod gradually rises. By making the No. 1 rod between the sliding rod and the top column longer, a greater force will be applied to the top cover when the height of the sliding rod changes by the same amount, thereby further enhancing the extrusion effect and preventing the casting from being empty or underfilled.

[0019] Preferably, the liquid outlet passes through the No. 1 groove, and the liquid outlet is arranged obliquely in the part inside the bottom plate.

[0020] During operation, when molten copper is filled into the mold cavity, in order to prevent the cold shut caused by excessive flow rate, the copper melting chamber is filled with low-pressure compressed gas with a pressure of 0.06-0.15MPa, so the pressure of squeezing the molten copper is relatively small, which makes the flow rate of the molten copper into the mold cavity relatively small; but the small flow rate may produce empty nests due to the poor fluidity of the molten copper. The oblique setting of the liquid outlet enhances the flow of the molten copper on the horizontal plane, which is beneficial to reduce the appearance of voids in the casting.

[0021] Preferably, the lower end portion of the wall surface in the cavity corresponding to the movement of the baffle is configured to be arc-shaped, and the lower end portion of the through hole is configured to be conical.

[0022] During operation, as the baffle gradually moves toward the inside of the cavity, the baffle squeezes the air in the cavity and sets the lower end of the wall of the cavity corresponding to the movement of the baffle into an arc shape, which reduces the resistance to air circulation, increases the fluidity of the air inside the cavity, and makes it easier for the air in the cavity to enter the through hole; at the same time, the lower end of the through hole is set to a cone shape, which facilitates more air to flow into the through hole and act on the lower part of the piston plate, ensuring that the piston plate is subjected to greater pressure, further enhancing the extrusion effect, and further preventing the casting from being empty and not filled.

[0023] The beneficial effects of the present invention are as follows:

[0024] 1. The motor rotor squirrel cage low-pressure copper casting equipment and copper casting method described in the present invention extend the telescopic rod, so that the clamping block squeezes the clamping plate driven by the telescopic rod, so that the clamping plate squeezes the space in the mold cavity, and the mold cavity space is gradually reduced; and at the same time, the copper liquid is not filled with air due to poor fluidity, and the air is discharged from the upper part of the mold cavity that has not been sealed temporarily under the squeezing of the clamping plate.

[0025] 2. The motor rotor squirrel cage low-pressure copper casting equipment and copper casting method described in the present invention gradually move the guide rod; the sliding rod is gradually lifted up; as the sliding rod is gradually lifted up, the upper end of the sliding rod rises, and the top cover is subjected to a downward pressure under the action of the No. 1 rod; the copper liquid is further compressed, and the air in the mold cavity is further reduced, ensuring that the casting is not empty and not filled. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below in conjunction with the accompanying drawings;

[0027] Figure 1 is a method flow chart of the processing method of the present invention;

[0028] Figure 2 It is a three-dimensional diagram of the low-pressure copper casting equipment of the present invention;

[0029] Figure 3 yes Figure 2 A cross-sectional view of the mold unit is shown in FIG.

[0030] Figure 4 It is a parts diagram of the splint in the present invention;

[0031] Figure 5 yes Figure 4 Cross-section of the middle splint;

[0032] Figure 6 yes Figure 2 A partial enlarged view of the middle A;

[0033] Figure 7 yes Figure 5 A partial enlarged view of point B in the middle;

[0034] Figure 8 is a cross-sectional view of the bottom plate of the present invention;

[0035] In the figure: shell 1, liquid inlet unit 2, copper melting chamber 21, air inlet 22, liquid outlet 23, space control unit 3, telescopic rod 31, clamping block 32, mold unit 4, bottom plate 41, No. 1 groove 411, center column 42, clamping plate 43, baffle 431, cavity 432, through hole 433, extrusion block 434, guide rod 435, sliding rod 436, top column 437, No. 1 rod 438, piston plate 439, top cover 44, mold cavity 45. DETAILED DESCRIPTION

[0036] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0037] like Figures 1 to 8 As shown, the present invention provides a motor rotor squirrel cage copper casting method, the copper casting method comprising the following steps:

[0038] S1: The copper melting chamber 21 is heated to melt the solid copper into a molten state, and then a low-pressure compressed gas with a pressure of 0.15-0.6 MPa is filled through the air inlet 22. As the gas accumulates on the upper part of the copper melting chamber, the molten copper gradually fills from the bottom of the bottom plate 41 to the top of the extrusion block 434; at this time, the top cover 44 is not squeezed by the clamping plate 43 and is tightly attached to form a seal, so the air inside the mold cavity 45 is gradually pushed out from the upper part of the mold cavity 45 by the molten copper;

[0039] S2: The telescopic rod 31 is gradually extended so that the clamping block 32 squeezes the clamping plate 43 under the drive of the telescopic rod 31, so that the clamping plate 43 squeezes the space in the mold cavity 45, so that the space is gradually reduced; and at the same time, the mold cavity 45 is not filled due to the poor fluidity of the copper liquid, and the condition of air inside is destroyed; and under the squeezing of the clamping plate 43, the air is discharged from the upper part of the mold cavity 45 that is not sealed temporarily; at the same time, the outer wall surface of the top cover 44 is also completely fitted with the inner wall surface of the clamping plate 43 to form a seal; so that the casting discharges the internal air and forms a sealed casting environment;

[0040] S3: The baffle 431 provided on the clamping plate 43 gradually moves into the cavity 432 inside the clamping plate 43, that is, the guide rod 435 gradually moves; and because the upper surface of the guide rod 435 is arranged obliquely, as the guide rod 435 gradually moves, the sliding rod 436 is gradually lifted up; as the sliding rod 436 is gradually lifted up, the upper end of the sliding rod 436 rises, and under the action of the No. 1 rod 438, the top cover 44 is subjected to a downward pressure;

[0041] S4: The middle part of the sliding rod 436 is the piston plate 439, and the internal sealing of the cavity 432 is strong. As the pressure increases, the upward pressure on the sliding rod 436 gradually increases; the end of the sliding rod 436 is subjected to an upward force under the action of the pressure; under the action of the No. 1 rod 438, the top cover 44 is subjected to a greater force, which further squeezes the molten copper and strengthens the squeezing effect; after the casting is completed, the casting is taken out and polished.

[0042] A motor rotor squirrel cage low-pressure copper casting device, the motor rotor squirrel cage low-pressure copper casting device is suitable for the above-mentioned copper casting method, the motor rotor squirrel cage low-pressure copper casting device comprises a shell 1, a liquid inlet unit 2, a space control unit 3 and a mold unit 4; the liquid inlet unit 2 comprises a copper melting chamber 21, an air inlet 22 and a liquid outlet 23; the copper melting chamber 21 is fixedly connected to the lower part of the shell 1, and a heating device is arranged in the copper melting chamber 21; the air inlet 22 is fixedly connected to and passes through the right side of the copper melting chamber 21 The side wall surface, the air inlet 22 is connected to the external air source; the space control unit 3 includes a telescopic rod 31 and a clamping block 32, the telescopic rod 31 is fixedly connected to the two side walls of the shell 1, the clamping block 32 is fixedly connected to the end of the telescopic rod 31, and the clamping block 32 is an arc plate; the mold unit 4 includes a bottom plate 41, a center column 42, a clamping plate 43 and a top cover 44; the bottom plate 41 is fixedly connected to the bottom of the shell 1, and the upper part of the bottom plate 41 is provided with an annular No. 1 groove 411 The liquid outlet 23 is located on the upper surface of the bottom plate 41 and communicates with the inside of the copper melting chamber 21, and the liquid outlet 23 is connected to the No. 1 slot 411; the central column 42 is fixedly connected to the central part of the bottom plate 41; a plurality of clamping plates 43 are slidably connected to the upper part of the bottom plate 41, and the clamping plates 43 are annularly distributed on the upper surface of the bottom plate 41, one end of the clamping plate 43 is fixedly connected to the baffle 431, and the other end is provided with a cavity 432 at a position corresponding to the baffle 431, and the end of the baffle 431 extends into the adjacent Inside the cavity 432 of the splint 43; the baffle 431 is slidably connected to the cavity 432 of the adjacent splint 43, and the baffle 431 and the cavity 432 are both arc-shaped; the area between the splint 43, the baffle 431 and the center column 42 is the mold cavity 45; the surface of the splint 43 close to the center column 42 is evenly provided with a plurality of extrusion blocks 434, the end surface of the extrusion block 434 close to the center column 42 is arc-shaped, and the upper part of the center column 42 is slidably connected to the top cover 44.

[0043] During operation, the copper melting chamber 21 is heated to melt the solid copper metal into a molten state, and then a low-pressure compressed gas with a pressure of 0.06-0.15 MPa is filled in through the air inlet 22. As the gas accumulates on the upper part of the copper melting chamber 21, the copper liquid inside the copper melting chamber 21 is squeezed through the liquid outlet 23 into the mold cavity 45 surrounded by the clamping plate 43 and the baffle 431, and the copper liquid is gradually filled from the bottom of the bottom plate 41 to the top of the extrusion block 434; in this process, the clamping block 32 is not completely squeezed by the telescopic rod 31, so The top cover 44 is not squeezed by the clamping plate 43 and is tightly attached to the mold cavity 45, so that the air inside the mold cavity 45 is gradually pushed out from the upper part of the mold cavity 45 by the molten copper, reducing the air in the mold cavity 45 and ensuring that the casting will not have a hollow nest due to the residual air inside. At the same time, as the molten copper gradually fills the mold cavity 45, the telescopic rod 31 gradually extends, so that the clamping block 32 squeezes the clamping plate 43 under the drive of the telescopic rod 31, so that the clamping plate 43 squeezes the space in the mold cavity 45, so that the space gradually The mold cavity 45 is reduced in size; because the molten copper inside the mold cavity 45 is evenly pressurized, the fluidity of the internal molten copper is enhanced, ensuring that the molten copper fully fills the mold cavity 45. Under the extrusion of the clamping plate 43, the air is discharged from the gap between the top cover 44 and the clamping plate 43, which is not yet completely sealed, to avoid the situation where the mold cavity 45 is not filled due to the poor fluidity of the molten copper, which leads to the appearance of an empty nest and affects the molding quality; as the telescopic rod 31 continues to move, the end of the extrusion block 434 on the inner side of the clamping plate 43 gradually approaches the central column 42, and finally fits completely with the surface of the central column 42, dividing the interior of the mold cavity 45 into several unconnected areas, and at the same time, the outer wall surface of the top cover 44 also fits completely with the inner wall surface of the clamping plate 43 to form a seal, so that the mold cavity 45 discharges the internal air and forms a sealed casting environment, and then the molten copper is cooled and formed in the unconnected area formed by the gap of the molten copper extrusion block 434 to form a ring-shaped copper strip, and the motor rotor squirrel cage cast copper part is finally obtained under the connection of the copper ring formed by the No. 1 groove 411 and the top cover 44.

[0044] As a specific embodiment of the present invention, the baffle 431 is fixedly connected to the guide rod 435 on the side wall inside the cavity 432, and the upper surface of the guide rod 435 is obliquely arranged. The upper part of the clamping plate 43 is provided with a through hole 433 penetrating the clamping plate 43, and a sliding rod 436 is slidably connected inside the through hole 433; the lower end of the sliding rod 436 is in contact with the upper surface of the guide rod 435; the top of the sliding rod 436 extends out of the through hole 433, and a top column 437 is fixedly connected to the side of the upper surface of the clamping plate 43 close to the top cover 44, and the top of the top column 437 is rotatably connected to a No. 1 rod 438; one end of the No. 1 rod 438 is embedded in the groove set at the upper end of the sliding rod 436, and the other end is in contact with the top cover 44.

[0045] During operation, when the molten copper is about to fill the mold cavity 45, the lower end of the sliding rod 436 contacts the upper end of the guide rod 435, and as the telescopic rod 31 drives the clamping block 32, the clamping block 32 squeezes the clamping plate 43 to move closer to the center column 42; the baffle 431 provided on the clamping plate 43 gradually moves into the cavity 432 inside the clamping plate 43, that is, the guide rod 435 gradually moves in the direction of going deeper into the cavity 432; and because the upper surface of the guide rod 435 is obliquely provided, and the bottom of the sliding rod 436 contacts the upper surface of the guide rod 435, as the guide rod 435 gradually moves deeper, the sliding rod 436 moves in the direction of going deeper into the guide rod 432. 5 is gradually lifted up; as the sliding rod 436 is gradually lifted up, the upper end of the sliding rod 436 presses the end of the No. 1 rod 438 that contacts, so that the No. 1 rod 438 rotates, so that the end of the No. 1 rod 438 that contacts the top cover 44 rotates downward, so that the top cover 44 is subjected to downward pressure due to the downward movement of the end that contacts the No. 1 rod 438; because the No. 1 rod 438 is annularly distributed, the top cover 44 is evenly forced to move downward, so that the copper water in the mold cavity 45 is further compressed, and the air in the mold cavity 45 is further reduced, so as to prevent the final formed copper casting from being empty and not full.

[0046] As a specific embodiment of the present invention, a piston plate 439 is fixedly connected to the middle of the sliding rod 436, and the outer wall of the piston plate 439 is tightly fitted with the inner wall of the through hole 433. The diameter of the sliding rod 436 located at the lower part of the piston plate 439 is smaller than the diameter of the through hole 433.

[0047] During operation, when the clamping plate 43 gradually approaches the central column 42, the baffle 431 will gradually move into the cavity 432. As the baffle 431 gradually moves into the cavity 432, the gas in the cavity 432 is pressurized and flows downward into the through hole 433. The lower diameter of the sliding rod 436 is smaller, so the air flowing into the through hole 433 accumulates in the gap between the lower part of the piston plate 439 on the sliding rod 436 and the side wall of the through hole 433, which increases the air pressure in this area. The cavity 432 has a strong sealing performance. As the air pressure increases, the piston plate 439 is pushed upward, and the sliding rod 436 is gradually increased by the upward force under the action of the piston plate 439, so that the sliding rod 436 is further stressed and squeezes the contacting end of the No. 1 rod 438; therefore, under the action of the No. 1 rod 438, the top cover 44 is further stressed, and the molten copper is further squeezed, thereby strengthening the squeezing effect and further preventing the casting from being empty and not full.

[0048] As a specific implementation of the present invention, the distance between the end of the sliding rod 436 and the end of the top column 437 is greater than the distance between the end of the top column 437 and the upper surface of the top cover 44.

[0049] During operation, with the movement between the guide rod 435 and the sliding rod 436, the sliding rod 436 is gradually lifted up. With the sliding rod 436 being gradually lifted up, the position where the top column 437 and the No. 1 rod 438 are rotatably connected serves as a fulcrum, and the No. 1 rod 438 is gradually tilted. With the rise of the sliding rod 436, the end of the top cover 44 is subjected to a downward force, and the force increases as the height of the sliding rod 436 gradually increases. Because the portion of the No. 1 rod 438 between the sliding rod 436 and the top column 437 is longer, with the rotation of the No. 1 rod 438, the No. 1 rod 438 plays the role of the No. 1 rod 438. According to the principle of the No. 1 rod 438, the pressure applied by the No. 1 rod 438 on the top cover 44 is greater than the supporting force applied by the sliding rod 436 on the No. 1 rod 438. Therefore, the top cover 44 further has an extrusion effect on the molten copper inside the mold cavity 45, further preventing the casting from being empty or not full.

[0050] As a specific implementation of the present invention, the liquid outlet 23 passes through the No. 1 groove 411 , and the liquid outlet 23 is obliquely arranged in the part inside the bottom plate 41 .

[0051] During operation, when the molten copper is filled into the mold cavity 45, in order to prevent the cold shut caused by too fast rolling due to excessive flow rate, the copper melting chamber 21 is filled with low-pressure compressed gas with a pressure of 0.06-0.15MPa, so the pressure of squeezing the molten copper is relatively small; the flow rate of the molten copper into the mold cavity 45 is relatively small; but the relatively small flow rate may cause hollow nests in the casting due to the poor fluidity of the molten copper. The liquid outlet 23 is arranged obliquely to increase the flow rate of the molten copper in the horizontal direction, thereby enhancing the fluidity of the molten copper in the mold cavity 45, which is beneficial to reducing the occurrence of hollow nests in the casting and further improving the quality of the casting.

[0052] As a specific embodiment of the present invention, the lower end of the wall surface in the cavity 432 corresponding to the movement of the baffle 431 is set to be arc-shaped, and the lower end of the through hole 433 is set to be conical.

[0053] During operation, as the baffle 431 gradually moves toward the inside of the cavity 432, the baffle 431 squeezes the air in the cavity 432, and the lower end of the wall of the cavity 432 corresponding to the movement of the baffle 431 is set to an arc shape, which reduces the resistance to air circulation, accelerates the air to flow downward into the through hole 433, and reduces the air pressure resistance encountered by the baffle 431 when entering the cavity 432; at the same time, the lower end of the through hole 433 is set to a cone shape, which accelerates more air to flow into the through hole 433 and act on the lower part of the piston plate 439, ensuring that the piston plate 439 is subjected to greater pressure, further enhancing the extrusion effect, and further preventing the casting from being empty and not filled.

[0054] The specific workflow is as follows:

[0055] During operation, the copper melting chamber 21 heats the solid copper metal to melt it into a molten state, and then low-pressure compressed gas with a pressure of 0.06-0.15 MPa is filled in through the air inlet 22, and the copper liquid gradually fills from the bottom of the bottom plate 41 to the top of the extrusion block 434; at this time, the top cover 44 is not squeezed by the clamping plate 43 and is tightly attached to form a seal; the telescopic rod 31 gradually extends so that the clamping plate 43 is squeezed by the clamping plate 43 under the drive of the telescopic rod 31, so that the clamping plate 43 squeezes the space in the mold cavity 45, and the space is gradually reduced; as the telescopic rod 31 continues to move, the end of the extrusion block 434 on the inner side of the clamping plate 43 gradually approaches the central column 42, and finally completely fits with the surface of the central column 42, At the same time, the outer wall surface of the top cover 44 is also completely fitted with the inner wall surface of the clamping plate 43 to form a seal; and when the baffle 431 provided on the clamping plate 43 gradually moves into the cavity 432 inside the clamping plate 43, that is, the guide rod 435 gradually moves; and because the thickness of the end of the guide rod 435 is small and the thickness of the connecting part of the baffle 431 is large, as the guide rod 435 gradually moves, the sliding rod 436 is gradually lifted up; as the sliding rod 436 is gradually lifted up, the upper end of the sliding rod 436 rises, and under the action of the No. 1 rod 438, the top cover 44 is subjected to a downward pressure, which squeezes the space in the mold cavity 45; after the rotor cage is completely formed, the casting is taken out for grinding.

[0056] The above-mentioned front, back, left, right, top and bottom are all based on the figures in the specification. Figure 2 As a benchmark, according to the person's observation perspective, the side of the device facing the observer is defined as the front, the left side of the observer is defined as the left, and so on.

[0057] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

[0058] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for low-pressure copper casting of a motor rotor cage, characterized in that: A motor rotor squirrel cage low-pressure copper casting device is used, the motor rotor squirrel cage low-pressure copper casting device comprising a housing (1), a liquid inlet unit (2), a space control unit (3) and a mold unit (4); the liquid inlet unit (2) comprises a copper melting chamber (21), an air inlet (22) and a liquid outlet (23); the copper melting chamber (21) is fixedly connected to the lower part of the housing (1), and a heating device is provided in the copper melting chamber (21); the air inlet (22) is fixedly connected to and passes through the right side wall of the copper melting chamber (21), and the air inlet (22) is connected to an external air source; The space control unit (3) comprises a telescopic rod (31) and a clamping block (32), wherein the telescopic rod (31) is fixedly connected to the two side walls of the shell (1), and the clamping block (32) is fixedly connected to the end of the telescopic rod (31), and the clamping block (32) is an arc-shaped plate; the mold unit (4) comprises a bottom plate (41), a center column (42), a clamping plate (43) and a top cover (44); the bottom plate (41) is fixedly connected to the bottom of the shell (1), and an annular No. 1 groove (411) is provided on the upper part of the bottom plate (41), and the liquid outlet (23) is located on the bottom plate (41) and communicate with the interior of the copper melting chamber (21), and the liquid outlet (23) is connected to the first tank (411); the central column (42) is fixedly connected to the central part of the bottom plate (41); a plurality of clamping plates (43) are slidably connected to the upper part of the bottom plate (41), and the clamping plates (43) are annularly distributed on the upper surface of the bottom plate (41), one end of the clamping plate (43) is fixedly connected to the baffle plate (431) and the other end is provided with a cavity (432) at a position corresponding to the baffle plate (431), and the end of the baffle plate (431) extends into the cavity of the adjacent clamping plate (43). (432); the baffle (431) is slidably connected to the cavity (432) of the adjacent clamping plate (43), and the baffle (431) and the cavity (432) are both arc-shaped; the area between the clamping plate (43), the baffle (431) and the center column (42) is the mold cavity (45); a plurality of extrusion blocks (434) are evenly arranged on the surface of the clamping plate (43) close to the center column (42), and the end surface of the extrusion block (434) close to the center column (42) is arc-shaped, and the upper part of the center column (42) is slidably connected to the top cover (44); The baffle (431) is fixedly connected to a guide rod (435) on the side wall inside the cavity (432); the upper surface of the guide rod (435) is obliquely arranged; the upper part of the clamping plate (43) is provided with a through hole (433) penetrating the clamping plate (43); a sliding rod (436) is slidably connected inside the through hole (433); the lower end of the sliding rod (436) is in contact with the upper surface of the guide rod (435); the top of the sliding rod (436) extends out of the through hole (433); a top column (437) is fixedly connected to the side of the upper surface of the clamping plate (43) close to the top cover (44); the top of the top column (437) is rotatably connected to a No. 1 rod (438); one end of the No. 1 rod (438) is embedded in a groove arranged at the upper end of the sliding rod (436), and the other end is in contact with the top cover (44); The motor rotor squirrel cage low-pressure copper casting method comprises the following steps: S1: The copper melting chamber (21) is heated to melt the solid copper into a molten state, and then a low-pressure compressed gas with a pressure of 0.06 to 0.15 MPa is charged through the gas inlet (22). As the gas accumulates at the upper part of the copper melting chamber, the molten copper gradually fills from the bottom of the bottom plate (41) to the top of the extrusion block (434); at this time, the top cover (44) is not squeezed by the clamping plate (43) and is tightly attached to form a seal, so the air inside the mold cavity (45) is gradually pushed out from the upper part of the mold cavity (45) by the molten copper; S2: the telescopic rod (31) is gradually extended so that the clamping block (32) is driven by the telescopic rod (31) to squeeze the clamping plate (43), so that the clamping plate (43) squeezes the space in the mold cavity (45), so that the space is gradually reduced; and at the same time, the mold cavity (45) is not filled due to the poor fluidity of the copper liquid, and the condition of air inside is destroyed; and under the pressure of the clamping plate (43), the air is discharged from the upper part of the mold cavity (45) that has not been sealed temporarily; at the same time, the outer wall surface of the top cover (44) is also completely fitted with the inner wall surface of the clamping plate (43) to form a seal; so that the air inside the casting is discharged and a sealed casting environment is formed; S3: The baffle (431) provided on the clamping plate (43) gradually moves into the cavity (432) inside the clamping plate (43), that is, the guide rod (435) gradually moves; and because the upper surface of the guide rod (435) is provided obliquely, as the guide rod (435) gradually moves, the sliding rod (436) is gradually lifted up; as the sliding rod (436) is gradually lifted up, the upper end of the sliding rod (436) rises, and under the action of the No. 1 rod (438), the top cover (44) is subjected to a downward pressure; S4: The middle part of the sliding rod (436) is a piston plate (439), and the internal sealing of the cavity (432) is strong. As the pressure increases, the upward pressure on the sliding rod (436) gradually increases; the end of the sliding rod (436) is subjected to an upward force under the action of the pressure; under the action of the No. 1 rod (438), the top cover (44) is subjected to a greater force, further squeezing the molten copper, thereby strengthening the squeezing effect; after the casting is completed, the casting is taken out for grinding.

2. The motor rotor squirrel cage low-pressure copper casting method according to claim 1, characterized in that: The middle of the sliding rod (436) is fixedly connected with a piston plate (439), the outer wall of the piston plate (439) is tightly fitted with the inner wall of the through hole (433), and the diameter of the sliding rod (436) located at the lower part of the piston plate (439) is smaller than the diameter of the through hole (433).

3. The motor rotor squirrel cage low-pressure copper casting method according to claim 1, characterized in that: The distance between the end of the sliding rod (436) and the end of the top column (437) is greater than the distance between the end of the top column (437) and the upper surface of the top cover (44).

4. The motor rotor squirrel cage low-pressure copper casting method according to claim 1, characterized in that: The liquid outlet (23) passes through the No. 1 groove (411), and the liquid outlet (23) is arranged obliquely in the part inside the bottom plate (41).

5. The motor rotor squirrel cage low-pressure copper casting method according to claim 1, characterized in that: The lower end of the wall surface in the cavity (432) corresponding to the movement of the baffle (431) is arranged in an arc shape, and the lower end of the through hole (433) is arranged in a conical shape.

Images