阅读说明：本技术 一种电机转子鼠笼低压铸铜设备及其铸铜方法 (Motor rotor squirrel cage low-pressure copper casting equipment and copper casting method thereof ) 是由 朱永全 王浩 于 2020-04-24 设计创作，主要内容包括：本发明属于电机制造技术领域,具体的说是一种电机转子鼠笼低压铸铜设备及其铸铜方法；包括保温炉和坩埚；坩埚通过升液管与铸造模型的型腔连通,且升液管分段螺纹连接设置；多个转动扇叶均通过转动柱转动设置的升液管的侧壁；转动柱通过转动套与升液管的侧壁转动连接,且转动柱上固定套接有凸轮；滑杆通过限位块滑动安装在升液管的侧壁；滑杆的顶端与凸轮的圆周外壁挤压接触,且滑杆的底端连接到弹性过滤网上；弹性过滤网设置有环形卡合圈和过滤网板；升液管的底端固定有合金密封环,且合金密封环的底端设置有过滤网板；防止金属液中含有的颗粒杂质或氧化渣跟随金属液进入到铸造模型的型腔内,导致浇筑的铸件产生氧化夹渣的现象。(The invention belongs to the technical field of motor manufacturing, in particular to a low-voltage copper casting device and a copper casting method for a squirrel cage of a motor rotor; comprises a holding furnace and a crucible; the crucible is communicated with a cavity of the casting model through a riser tube, and the riser tube is arranged in a threaded connection manner in sections; the plurality of rotating fan blades are arranged on the side wall of the liquid lifting pipe in a rotating mode through the rotating column; the rotating column is rotationally connected with the side wall of the liquid lifting pipe through a rotating sleeve, and a cam is fixedly sleeved on the rotating column; the slide rod is slidably arranged on the side wall of the lift pipe through a limiting block; the top end of the sliding rod is in pressing contact with the circumferential outer wall of the cam, and the bottom end of the sliding rod is connected to the elastic filter screen; the elastic filter screen is provided with an annular clamping ring and a filter screen plate; an alloy sealing ring is fixed at the bottom end of the liquid lifting pipe, and a filter screen plate is arranged at the bottom end of the alloy sealing ring; particle impurities or oxidation slag contained in the molten metal are prevented from entering a cavity of the casting model along with the molten metal, so that the phenomenon of oxidation slag inclusion of a cast casting is prevented.)

1. A low-pressure copper casting device for a squirrel cage of a motor rotor comprises a holding furnace (1), a crucible (2), a casting model (3) and a lifting mechanism (4); a crucible (2) is hermetically arranged in the heat preservation furnace (1), and a casting model (3) is arranged above the heat preservation furnace (1); the movable mould of the casting model (3) is hoisted through the lifting mechanism (4); the method is characterized in that: an air inlet pipe (5) is arranged on one side of the heat preservation furnace (1), and the air inlet pipe (5) supplies air to the crucible (2) through a pressure control system; a liquid inlet guide pipe is arranged on the other side of the heat preservation furnace (1), and a hydraulic control valve is arranged on the liquid inlet guide pipe; the crucible (2) is communicated with a cavity of the casting model (3) through a liquid lifting pipe (6), and the liquid lifting pipe (6) is arranged in a threaded connection way in sections; the impurity filtering device (7) is arranged on the liquid lifting pipe (6), and the impurity filtering device (7) comprises a rotating fan blade (71), a rotating column (72), a cam (73), a sliding rod (74), a limiting block (75), an elastic filter screen (8) and an alloy sealing ring (76); the rotating fan blades (71) are rotatably arranged on the side wall of the liquid lifting pipe (6) through the rotating column (72), the rotating fan blades (71) are higher than the maximum height of molten metal in the crucible (2), and the rotating fan blades (71) are positioned at the bottom end of the pipe opening of the air inlet mechanism (5); the rotating column (72) is rotatably connected with the side wall of the liquid lifting pipe (6) through a rotating sleeve, and a cam (73) is fixedly sleeved on the rotating column (72); the sliding rod (74) is slidably mounted on the side wall of the liquid lifting pipe (6) through a limiting block (75), the sliding rod (74) is sleeved with a spring, and the spring is located on the upper end face of the limiting block (75); the top end of the sliding rod (74) is in pressing contact with the circumferential outer wall of the cam (73), and the bottom end of the sliding rod (74) is connected to the elastic filter screen (8); the elastic filter screen (8) is provided with an annular clamping ring (81) and a filter screen plate (82); an alloy sealing ring (76) is fixed at the bottom end of the liquid lifting pipe (6), and a filter screen plate (82) is arranged at the bottom end of the alloy sealing ring (76); the filter screen plate (82) is clamped above the alloy sealing ring (76) in a sliding mode through the annular clamping ring (81), and high-temperature-resistant soft rubber (9) is filled in the annular clamping ring (81) and the upper end face of the alloy sealing ring (76).

2. The low-pressure copper casting equipment for the squirrel cage of the motor rotor as claimed in claim 1, wherein: glue injection holes (811) are uniformly formed in the circumferential outer wall of the annular clamping ring (81), and the annular clamping ring (81) is in sliding sealing contact with the outer wall of the lower section of the riser tube (6); high temperature resistant soft glue (9) adopt the mode of embedment to inject into annular block circle (81) inside through annotating gluey hole (811) many times, and the thickness of embedment should 2 ~ 3mm at every turn.

3. The motor rotor squirrel cage low pressure copper casting apparatus of claim 2, wherein: the inner wall of the annular clamping ring (81) is provided with a corrugated groove (812); a plurality of elastic support bars (10) are arranged on the upper end face of the alloy sealing ring (76), and the top ends of the elastic support bars (10) are in contact with the inner wall of the step at the upper end of the annular clamping ring (81); the side wall of the elastic supporting strip (10) is provided with corrugated protrusions (101), and the corrugated protrusions (101) are in pressing contact with the corrugated grooves (812).

4. The motor rotor squirrel cage low pressure copper casting apparatus of claim 3, wherein: the upper end of the annular clamping ring (81) is provided with an arc inclined plane; the bottom end of the sliding rod (74) is elastically bonded to the annular clamping ring (81) through high-temperature-resistant soft glue (9).

5. The motor rotor squirrel cage low pressure copper casting apparatus of claim 4, wherein: an annular clamping cavity (813) is formed in the inner ring wall of the annular clamping ring (81), and the top end of the annular clamping cavity (813) is connected with a spring; a plurality of arc-shaped concave blocks (20) are arranged on the outer wall of the lower section of the liquid lifting pipe (6) in a segmented mode, the arc-shaped concave blocks (20) are located in the annular clamping cavity (813), and the upper end faces of the arc-shaped concave blocks (20) are in contact with the springs; the arc-shaped concave block (20) is made of rigid materials.

6. A method for casting copper at low pressure in a squirrel cage of a motor rotor is characterized by comprising the following steps: the method is suitable for the use of the motor rotor squirrel-cage low-pressure copper casting equipment disclosed by the claims 1-5; the method comprises the following steps:

s1: melting and heating: putting a copper raw material into a melting furnace for melting, wherein the temperature of the melting furnace is 1000-1150 ℃; simultaneously, preheating a rotor formed by overlapping silicon steel sheets at a low temperature of 120-150 ℃; the preheated rotor is placed into a cavity of the casting model (3) by the manipulator;

s2: liquid guiding and stamping: introducing the copper raw material melted in the step S1 into the crucible (2) through a liquid guide pipe; the pressure control system leads compressed air with certain pressure into the sealed crucible (2) to ensure that the molten metal stably rises to a pouring gate of the casting mould along the riser tube (6);

s3: filtering the solution: the compressed air in the crucible (2) can blow the impurity filtering device (7) to generate vibration at the bottom end of the segmented liquid lifting pipe (6), and the vibration of the elastic filtering net (8) can shake and filter impurities or slag contained in the molten metal at a constant speed, so that the filtered molten metal enters the cavity from the pouring channel until the casting mold (3) is filled;

s4: pressurization, pressure maintaining and exhaust: after the metal liquid is filled in the cavity, the pressure control system increases a certain pressure for 3-5 min under the original mold filling pressure in the crucible (2); immediately maintaining the pressure to make the casting crystallize and solidify under stable pressure; after the casting is solidified, the air pressure in the crucible (2) is discharged, so that the liquid metal which is not solidified in the riser tube (6) and the pouring channel falls back into the crucible (2), and the casting is taken out through the lifting mechanism (4) after the casting is cooled.

Technical Field

The invention belongs to the technical field of motor manufacturing, and particularly relates to a low-voltage copper casting device and a copper casting method for a squirrel cage of a motor rotor.

Background

A squirrel cage motor is one of three-phase asynchronous motors, and a squirrel cage rotor is a rotating part of the squirrel cage motor. Generally, a rotor coil made of copper or aluminum is cast in a cage-shaped groove on a rotor core, and the coil is a closed loop which is not connected with other parts and mainly used for inhibiting stator current.

Common copper casting methods of the motor rotor squirrel cage include three types, namely pressure copper casting, centrifugal copper casting and low-pressure copper casting; the pressure casting couple has the advantages of high production efficiency, capability of molding a plurality of pieces and the like, and is easy to realize mechanization and automation. The common equipment is a vertical or horizontal die casting machine and a melting system thereof; the centrifugal cast aluminum production is characterized by simpler equipment; the low-pressure cast aluminum production features simple equipment, convenient manufacture, less investment and easy realization of mechanization and automation.

Chinese patent discloses a cast copper equipment of electric motor rotor squirrel cage low pressure, and patent application number is 2017213166358, be provided with the pressurized oven between copper melting furnace and the casting press, be connected through the deoxidization pipeline between copper melting furnace and the pressurized oven, deoxidization pipeline and pressurized oven connecting portion are provided with the vacuum gate, are provided with vacuum apparatus on the flowing liquid passageway, are provided with between mould and the flowing liquid passageway and lead to agent feeding device and mixing arrangement, are provided with the controller in the cast copper equipment of electric motor rotor squirrel cage low pressure.

The production efficiency can be improved and the labor intensity can be reduced; however, when the existing low-pressure copper casting equipment enters molten metal into the cavity through the lift pipe under the action of compressed air, the phenomenon of oxidation slag can be generated due to the influence of the temperature of the compressed air on the upper layer of the molten metal, and particle impurities or the oxidation slag contained in the molten metal enter the cavity of the casting model along with the molten metal, so that the phenomenon of oxidation slag inclusion of a cast casting is caused, and the casting quality of a motor rotor squirrel cage is influenced.

Disclosure of Invention

In order to make up for the defects of the prior art, the invention provides the motor rotor squirrel cage low-pressure copper casting equipment and the copper casting method thereof, which are mainly used for solving the problem that when molten metal enters a cavity through a riser pipe under the action of compressed air, particle impurities or metal slag contained in the molten metal enters the cavity of a casting model along with the molten metal, so that a cast casting is oxidized and slag is clamped, and the casting quality of the motor rotor squirrel cage is influenced.

The technical scheme adopted by the invention to solve the technical problem is as follows: the invention relates to a low-pressure copper casting device for a squirrel cage of a motor rotor, which comprises a holding furnace, a crucible, a casting model and a lifting mechanism, wherein the holding furnace is arranged on the upper part of the crucible; a crucible is arranged in the heat preservation furnace in a sealed mode, and a casting model is arranged above the heat preservation furnace; the movable mould of the casting model is hoisted through a lifting mechanism; an air inlet mechanism is arranged on one side of the heat preservation furnace and supplies air to the crucible through a pressure control system; a liquid inlet guide pipe is arranged on the other side of the heat preservation furnace, and a liquid control valve is arranged on the liquid inlet guide pipe; the crucible is communicated with a cavity of the casting model through a liquid lifting pipe, and the liquid lifting pipe is arranged in a threaded connection mode in sections; the liquid lifting pipe is provided with an impurity filtering device, and the impurity filtering device comprises a rotating fan blade, a rotating column, a cam, a sliding rod, a limiting block, an elastic filter screen and an alloy sealing ring; the rotating fan blades are arranged on the side wall of the liquid lifting pipe in a rotating mode through the rotating column, the rotating fan blades are higher than the maximum height of molten metal in the crucible, and the rotating fan blades are located at the bottom end of the pipe opening of the air inlet pipe mechanism; the rotating column is rotatably connected with the side wall of the liquid lifting pipe through a rotating sleeve, and a cam is fixedly sleeved on the rotating column; the slide rod is slidably mounted on the side wall of the liquid lifting pipe through a limiting block, and the slide rod is sleeved with a spring which is positioned on the upper end face of the limiting block; the top end of the sliding rod is in compression contact with the circumferential outer wall of the cam, and the bottom end of the sliding rod is connected to the elastic filter screen; the elastic filter screen is provided with an annular clamping ring and a filter screen plate; an alloy sealing ring is fixed at the bottom end of the liquid lifting pipe, and a filter screen plate is arranged at the bottom end of the alloy sealing ring; the filter screen plate is clamped above the alloy sealing ring in a sliding manner through an annular clamping ring, and high-temperature-resistant soft glue is filled in the annular clamping ring and the upper end surface of the alloy sealing ring;

when the device works, when molten metal in the crucible enters the liquid lifting pipe through compressed air, the compressed air can blow the rotating fan blades to rotate, the rotating column can drive the cam to extrude the sliding rod, so that the slide bar slides up and down along the side wall of the riser tube, the elastic filter screen is elastically connected to the alloy sealing ring through the high-temperature-resistant soft rubber, the bottom end of the slide bar is in contact with the elastic filter screen, the sliding rod slides up and down to extrude the elastic filter screen, so that the elastic filter screen swings up and down at the pipe orifice of the riser tube, the swing of the elastic filter screen can shake and filter the oxidation slag generated by the influence of the temperature of the compressed air on the upper layer of the molten metal and the particles mixed in the molten metal, further, particle impurities or metal slag contained in the molten metal can be prevented from entering a cavity of the casting model along with the molten metal, so that the phenomenon of oxidizing and slag inclusion of a cast casting is caused, and the squirrel-cage casting quality of the motor rotor is further influenced; meanwhile, the shaken elastic filter screen can ensure that the molten metal can stably rise in the liquid lifting pipe, and prevent the molten metal from splashing in the cavity, so that slag inclusion in the casting is caused; meanwhile, the shake of the elastic filter screen prevents the phenomenon that the elastic filter screen is blocked because oxidation slag is bonded on the elastic filter screen, so that the phenomenon that the elastic filter screen efficiently filters molten metal is influenced, and the phenomenon that the molten metal stably enters a liquid lifting pipe is influenced, so that the efficient work of low-pressure copper casting equipment is influenced; the stalk that the segmentation set up, installer can set up the impurity filter screen earlier on the stalk of hypomere, then with the stalk threaded connection of hypomere on the stalk of upper end stalk, and then be convenient for clear up or change the operation to the elasticity filter screen the sediment that presss from both sides that falls into in the elasticity filter screen.

Preferably, glue injection holes are uniformly formed in the circumferential outer wall of the annular clamping ring, and the annular clamping ring is in sliding sealing contact with the outer wall of the lower section of the riser tube; the high-temperature-resistant soft glue is injected into the annular clamping ring through the glue injection hole for multiple times in a potting mode, and the thickness of each potting is required to be-mm; during operation, adopt the mode of embedment to fill annular block circle and alloy sealing ring with high temperature resistant soft glue between, the elasticity filter screen of being convenient for can the elastic mounting to the stalk of hypomere, high temperature resistant soft glue not only can play the sealed effect of bonding simultaneously, and high temperature resistant soft glue product relies on the moisture content among the contact air to vulcanize into the elastomer by oneself simultaneously, and then the elasticity filter screen of being convenient for can realize the effect of shake about the bottom production of stalk under the extrusion of sliding from top to bottom of slide bar.

Preferably, the inner wall of the annular clamping ring is provided with a corrugated groove; the upper end surface of the alloy sealing ring is provided with a plurality of elastic supporting strips, and the top ends of the elastic supporting strips are in contact with the inner wall of the step at the upper end of the annular clamping ring; the side wall of the elastic supporting bar is provided with a corrugated bulge, and the corrugated bulge is in extrusion contact with the corrugated groove; when the device works, when the annular clamping ring compresses the high-temperature-resistant soft rubber under the extrusion of the sliding rod, the elastic supporting strip arranged at the upper end of the alloy sealing ring can be compressed under the extrusion force of the annular clamping ring, the compression of the elastic supporting strip can enable the corrugated bulge arranged at one side to be contracted and clamped into the corrugated groove arranged on the inner wall of the annular clamping ring, and meanwhile, the top end of the elastic supporting strip can be compressed and tightly abutted to the upper stepped wall of the annular clamping ring, so that the elastic supporting strip can play a role in elastic supporting and limiting the annular clamping ring, and the phenomenon that the annular clamping ring is inclined to separate from the outer wall of the liquid lifting pipe due to sliding sealing contact, rather than sliding clamping contact, of the annular clamping ring and the outer wall of the liquid lifting pipe caused by the extrusion force of the sliding rod is effectively prevented when the sliding rod extrudes the upper end of the annular clamping ring, meanwhile, the phenomenon of stable up-and-down shaking of the elastic filter screen is influenced.

Preferably, the upper end of the annular clamping ring is arranged as an arc inclined plane; the bottom end of the sliding rod is elastically bonded to the annular clamping ring through high-temperature-resistant soft glue; when the metal liquid clamping ring works, the upper end of the annular clamping ring is an arc-shaped inclined surface, so that the phenomenon that metal liquid is gathered on the annular clamping ring to be solidified and agglomerated is prevented; simultaneously, the slide rod is elastically connected with the annular clamping ring, so that the slide rod can play a gravity supporting effect on the elastic filter screen, and meanwhile, the slide rod can stably extrude the elastic filter screen.

Preferably, an annular clamping cavity is formed in the inner ring wall of the annular clamping ring, and the top end of the annular clamping cavity is connected with a spring; a plurality of arc-shaped concave blocks are arranged on the outer wall of the lower section of the liquid lifting pipe in a segmented mode, the arc-shaped concave blocks are located in the annular clamping cavity, and the upper end faces of the arc-shaped concave blocks are in contact with the springs; the arc-shaped sunken block is made of rigid materials; when the annular clamping ring slides up and down under the extrusion of the sliding rod, the spring on the inner wall of the annular clamping cavity can be extruded into the concave groove of the arc-shaped concave block, so that the spring can perform sliding support operation on the annular clamping ring, and meanwhile, the inner wall of the annular clamping ring can be stably attached to the outer wall of the lift pipe; meanwhile, the restoring force of the spring can also enable the sliding rod to swing upwards at a constant speed, so that the elastic filter screen can synchronously swing upwards at a constant speed, the shaking of the elastic filter screen is in a constant speed state, and the elastic filter screen can conveniently enable the molten metal to rise at a constant speed in the liquid lifting pipe.

The invention relates to a method for casting copper on a squirrel cage of a motor rotor at low pressure, which is suitable for the use of the equipment for casting copper on the squirrel cage of the motor rotor at low pressure; the method comprises the following steps:

s1: melting and heating: putting a copper raw material into a melting furnace for melting, wherein the temperature of the melting furnace is 1000-1150 ℃; simultaneously, preheating a rotor formed by overlapping silicon steel sheets at a low temperature of 120-150 ℃; the preheated rotor is placed into a cavity of a casting model by a manipulator;

s2: liquid guiding and stamping: introducing the copper raw material melted in the step S1 into the crucible through a liquid guide pipe; the pressure control system leads compressed air with certain pressure into the sealed crucible, so that the molten metal stably rises to a pouring gate of the casting mold along the riser tube;

s3: filtering the solution: compressed air in the crucible can blow the impurity filtering device to generate vibration at the bottom end of the segmented riser tube, and the vibration of the elastic filter screen can shake and filter impurities or slag contained in molten metal at a constant speed, so that the filtered molten metal enters the cavity from the pouring channel until the casting mold is filled; the swing of the elastic filter screen can shake and filter particle impurities or metal slag mixed in the molten metal, so that the phenomenon that the poured casting is oxidized and slag-clamped due to the fact that the particle impurities or the metal slag contained in the molten metal enter a cavity of a casting model along with the molten metal can be prevented, and the casting quality of the motor rotor squirrel cage is influenced;

s4: pressurization, pressure maintaining and exhaust: after the metal liquid is filled in the cavity, the pressure control system increases a certain value of pressure for 3-5 min under the original mold filling pressure in the crucible; immediately maintaining the pressure to make the casting crystallize and solidify under stable pressure; after the casting is solidified, the air pressure in the crucible is discharged, so that the metal liquid which is not solidified in the riser tube and the pouring gate falls back into the crucible, and the casting is taken out through the lifting mechanism after the casting is cooled; a certain amount of external pressure is charged in the casting solidification feeding process, so that the feeding effect of the casting is good, the density of the casting is high, and the mechanical property is good; the casting can be efficiently crystallized and solidified under stable pressure through the pressure maintaining treatment.

The invention has the following beneficial effects:

1. according to the invention, the vibration of the elastic filter screen can shake and filter the oxidation slag generated by the influence of the temperature of compressed air on the upper layer of the molten metal and the particles mixed in the molten metal, so that the phenomenon that the cast casting is oxidized and slag is included due to the fact that particle impurities or metal slag contained in the molten metal enter the cavity of the casting model along with the molten metal can be prevented, and the casting quality of the motor rotor squirrel cage is further influenced.

2. According to the invention, through the processes of pressurization and pressure maintaining, a certain amount of external pressure can be charged in the casting solidification feeding process through pressurization, so that the feeding effect of the casting is good, the density of the casting is high, and the mechanical property is good; the casting can be efficiently crystallized and solidified under stable pressure through the pressure maintaining treatment.

Drawings

The invention will be further explained with reference to the drawings.

FIG. 1 is a perspective view of the present invention;

FIG. 2 is a cross-sectional view of the present invention;

FIG. 3 is a view of the flexible filter screen and riser tube of the present invention;

FIG. 4 is a flow chart of a method of the present invention;

in the figure: the device comprises a heat preservation furnace 1, a crucible 2, a casting model 3, a lifting mechanism 4, an air inlet pipe 5, a liquid lifting pipe 6, an impurity filtering device 7, a rotating fan blade 71, a rotating column 72, a cam 73, a sliding rod 74, a limiting block 75, an alloy sealing ring 76, an elastic filtering net 8, an annular clamping ring 81, an adhesive injection hole 811, a corrugated groove 812, an annular clamping cavity 813, a filtering net plate 82, high-temperature-resistant soft adhesive 9, an elastic supporting strip 10, a corrugated bulge 101 and an arc-shaped sunken block 20.

Detailed Description

A low-pressure copper casting apparatus for a squirrel cage of a motor rotor and a copper casting method thereof according to an embodiment of the present invention will be described below with reference to fig. 1 to 4.

As shown in figures 1-4, the squirrel-cage low-pressure copper casting equipment for the motor rotor comprises a holding furnace 1, a crucible 2, a casting model 3 and a lifting mechanism 4; a crucible 2 is hermetically arranged in the heat preservation furnace 1, and a casting model 3 is arranged above the heat preservation furnace 1; the movable mould of the casting model 3 is hoisted through the lifting mechanism 4; an air inlet pipe 5 is arranged on one side of the heat preservation furnace 1, and the air inlet pipe 5 supplies air to the crucible 2 through a pressure control system; a liquid inlet guide pipe is arranged on the other side of the heat preservation furnace 1, and a hydraulic control valve is arranged on the liquid inlet guide pipe; the crucible 2 is communicated with a cavity of the casting model 3 through a liquid lifting pipe 6, and the liquid lifting pipe 6 is arranged in a threaded connection way in sections; the liquid lifting pipe 6 is provided with an impurity filtering device 7, and the impurity filtering device 7 comprises a rotating fan blade 71, a rotating column 72, a cam 73, a sliding rod 74, a limiting block 75, an elastic filter screen 8 and an alloy sealing ring 76; the plurality of rotating blades 71 are rotatably arranged on the side wall of the liquid lifting pipe 6 through the rotating column 72, the rotating blades 71 are higher than the maximum height of the molten metal in the crucible 2, and the rotating blades 71 are positioned at the bottom end of the pipe orifice of the air inlet pipe 5; the rotating column 72 is rotatably connected with the side wall of the riser tube 6 through a rotating sleeve, and a cam 73 is fixedly sleeved on the rotating column 72; the slide rod 74 is slidably mounted on the side wall of the lift tube 6 through a limiting block 75, and the slide rod 74 is sleeved with a spring which is positioned on the upper end face of the limiting block 75; the top end of the sliding rod 74 is in pressing contact with the circumferential outer wall of the cam 73, and the bottom end of the sliding rod 74 is connected to the elastic filter screen 8; the elastic filter screen 8 is provided with an annular clamping ring 81 and a filter screen plate 82; an alloy sealing ring 76 is fixed at the bottom end of the liquid lifting pipe 6, and a filter screen plate 82 is arranged at the bottom end of the alloy sealing ring 76; the filter screen plate 82 is clamped above the alloy sealing ring 76 in a sliding manner through an annular clamping ring 81, and the interior of the annular clamping ring 81 and the upper end surface of the alloy sealing ring 76 are filled with high-temperature-resistant soft rubber 9;

when the device works, when molten metal in the crucible 2 enters the riser tube 6 through compressed air, the compressed air blows the rotating fan blades 71 to rotate, the rotating column 72 drives the cam 73 to extrude the sliding rod 74, so that the sliding rod 74 slides up and down along the side wall of the riser tube 6, the elastic filter screen 8 is elastically connected to the alloy sealing ring 76 through the high-temperature-resistant soft rubber 9, the bottom end of the sliding rod 74 is in contact with the elastic filter screen 8, and the sliding rod 74 slides up and down to extrude the elastic filter screen 8, so that the elastic filter screen 8 swings up and down at the tube opening of the riser tube 6, the swinging of the elastic filter screen 8 can shake and filter oxidized slag generated by the influence of the temperature of the compressed air on the upper layer of the molten metal and particles mixed in the molten metal, and further can prevent the phenomenon that the cast casting generates oxidized slag due to the fact that the granular impurities or metal slag contained in the molten metal enters the cavity of the casting model, thereby influencing the casting quality of the squirrel cage of the motor rotor; meanwhile, the shaken elastic filter screen 8 can ensure that the molten metal can stably rise in the riser tube 6, and prevent the molten metal from splashing in the cavity, thereby preventing the slag inclusion in the casting; meanwhile, the shake of the elastic filter screen 8 prevents the phenomenon that the elastic filter screen 8 is blocked due to the bonding of oxidation slag inclusion on the elastic filter screen 8, so that the phenomenon that the elastic filter screen 8 efficiently filters molten metal is influenced, and the phenomenon that the molten metal stably enters the lift pipe 6 is influenced, so that the efficient work of low-pressure copper casting equipment is influenced; the stalk 6 that the segmentation set up, installer can set up the impurity filter screen earlier on the stalk 6 of hypomere, then with 6 threaded connection of stalk 6 of hypomere on the stalk 6 of upper end, and then be convenient for clear up or change the operation to the sediment of pressing from both sides that falls into in the elastic filter screen 8.

As an embodiment of the present invention, glue injection holes 811 are uniformly formed in the circumferential outer wall of the annular clamping ring 81, and the annular clamping ring 81 is in sliding sealing contact with the outer wall of the lower lift tube 6; the high-temperature-resistant soft glue 9 is injected into the annular clamping ring 81 through the glue injection hole 811 for multiple times in a potting mode, and the thickness of each potting is 2-3 mm; during operation, fill annular block circle 81 and alloy seal ring 76 with high temperature resistant soft glue 9 between adopting the mode of embedment, the elastic filter net 8 of being convenient for can the elastic mounting on the stalk 6 of hypomere, high temperature resistant soft glue 9 not only can play the sealed effect of bonding simultaneously, simultaneously high temperature resistant soft glue 9 product draws close to the moisture content of contact air and vulcanizes into the elastomer by oneself, and then the elastic filter net 8 of being convenient for can realize producing the effect of shake from top to bottom in the bottom of stalk 6 under the extrusion of sliding rod 74's upper and lower slip.

As an embodiment of the present invention, a corrugated groove 812 is formed on an inner wall of the annular engaging ring 81; the upper end surface of the alloy sealing ring 76 is provided with a plurality of elastic supporting strips 10, and the top ends of the elastic supporting strips 10 are in contact with the upper stepped inner wall of the annular clamping ring 81; the side wall of the elastic supporting bar 10 is provided with a corrugated protrusion 101, and the corrugated protrusion 101 is in pressing contact with the corrugated groove 812; when the device works, when the annular clamping ring 81 compresses the high-temperature-resistant soft rubber 9 under the extrusion of the sliding rod 74, the elastic support strip 10 arranged at the upper end of the alloy sealing ring 76 is compressed under the extrusion force of the annular clamping ring 81, the compression of the elastic support strip 10 can enable the corrugated bulge 101 arranged at one side to be contracted and clamped into the corrugated groove 812 arranged on the inner wall of the annular clamping ring 81, and meanwhile, the top end of the elastic support strip 10 can be compressed and tightly abutted against the upper end step wall of the annular clamping ring 81, so that the elastic support strip 10 can play a role of elastic support and limitation on the annular clamping ring 81, and the phenomenon that when the sliding rod 74 extrudes to the upper end of the annular clamping ring 81, the annular clamping ring 81 is in sliding sealing contact with the outer wall of the lower liquid lifting pipe 6 instead of sliding clamping contact, and further the extrusion force of the sliding rod 74 can incline and separate from the outer wall of the liquid lifting, thereby affecting the sliding sealing effect between the annular clamping ring 81 and the outer wall of the riser tube 6 and simultaneously affecting the up-and-down stable shaking phenomenon of the elastic filter screen 8.

As an embodiment of the present invention, the upper end of the annular engaging ring 81 is disposed as an arc inclined plane; the bottom end of the sliding rod 74 is elastically bonded to the annular clamping ring 81 through high-temperature-resistant soft rubber 9; when the device works, the upper end of the annular clamping ring 81 is an arc-shaped inclined surface, so that the phenomenon that molten metal is gathered on the annular clamping ring 81 to be solidified and agglomerated is prevented; meanwhile, the slide rod 74 is elastically connected with the annular clamping ring 81, so that the slide rod 74 can support the elastic filter screen 8 by gravity, and meanwhile, the slide rod 74 can stably extrude the elastic filter screen 8.

As an embodiment of the present invention, an annular engaging cavity 813 is formed on an inner wall of the annular engaging ring 81, and a spring is connected to a top end of the annular engaging cavity 813; a plurality of arc-shaped concave blocks 20 are arranged on the outer wall of the lower section of the liquid lifting pipe 6 in a segmented manner, the arc-shaped concave blocks 20 are positioned in the annular clamping cavity 813, and the upper end surfaces of the arc-shaped concave blocks 20 are in contact with the spring; the arc-shaped concave block 20 is made of rigid materials; during operation, when the annular clamping ring 81 slides up and down under the extrusion of the sliding rod 74, the spring arranged in the annular clamping cavity 813 can extrude into the concave groove of the arc-shaped concave block 20, so that the spring can perform sliding support operation on the annular clamping ring 81, and meanwhile, the inner wall of the annular clamping ring 81 can be stably attached to the outer wall of the lift pipe 6; meanwhile, the restoring force of the spring can also enable the elastic filter screen 8 to synchronously swing upwards at a constant speed when the sliding rod 74 swings upwards, so that the elastic filter screen 8 shakes at a constant speed, and the elastic filter screen 8 can enable the molten metal to rise at a constant speed in the lift pipe 6.

The invention relates to a method for casting copper on a squirrel cage of a motor rotor at low pressure, which is suitable for the use of the equipment for casting copper on the squirrel cage of the motor rotor at low pressure; the method comprises the following steps:

s1: melting and heating: putting a copper raw material into a melting furnace for melting, wherein the temperature of the melting furnace is 1000-1150 ℃; simultaneously, preheating a rotor formed by overlapping silicon steel sheets at a low temperature of 120-150 ℃; the preheated rotor is placed into a cavity of the casting model 3 by a manipulator;

s2: liquid guiding and stamping: introducing the copper raw material melted in the step S1 into the crucible 2 through a liquid guide pipe; the pressure control system leads compressed air with certain pressure into the sealed crucible 2, so that the molten metal stably rises to a pouring gate of the casting mould along the riser tube 6;

s3: filtering the solution: the compressed air in the crucible 2 can blow the impurity filtering device 7 to generate vibration at the bottom end of the segmented riser tube 6, and the vibration of the elastic filter screen 8 can perform uniform-speed shaking filtering on impurities or slag contained in the molten metal, so that the filtered molten metal enters the cavity from the pouring channel until the casting mold 3 is filled; the swing of the elastic filter screen 8 can shake and filter particle impurities or metal slag mixed in the molten metal, so that the phenomenon that hungry particle impurities or metal slag contained in the molten metal enter a cavity of the casting model 3 along with the molten metal to cause the cast casting to generate oxidation slag inclusion and further influence the casting quality of the squirrel cage of the motor rotor

S4: pressurization, pressure maintaining and exhaust: after the metal liquid is filled in the cavity, the pressure control system increases a certain pressure for 3-5 min under the original mold filling pressure in the crucible 2; immediately maintaining the pressure to make the casting crystallize and solidify under stable pressure; after the casting is solidified, the air pressure in the crucible 2 is discharged, so that the metal liquid which is not solidified in the riser tube 6 and the pouring channel falls back into the crucible 2, and the casting is taken out through the lifting mechanism 4 after the casting is cooled; a certain amount of external pressure is charged in the casting solidification feeding process, so that the feeding effect of the casting is good, the density of the casting is high, and the mechanical property is good; the casting can be efficiently crystallized and solidified under stable pressure through the pressure maintaining treatment.

The specific working process is as follows:

when in work, the copper raw material is put into a melting furnace for melting, and the temperature of the melting furnace is 1000-1150 ℃; simultaneously, preheating a rotor formed by overlapping silicon steel sheets at a low temperature of 120-150 ℃; the preheated rotor is placed into a cavity of the casting model 3 by a manipulator, and the copper raw material metal liquid is guided into the crucible 2 through a liquid guide pipe; compressed air with certain pressure is introduced into a sealed crucible 2 by a pressure control system, so that molten metal stably rises to a pouring gate of a casting mold along a riser tube 6, the compressed air in the crucible 2 can blow an impurity filtering device 7 to generate vibration at the bottom end of the segmented riser tube 6, the vibration of an elastic filter screen 8 can shake and filter impurities or slag contained in the molten metal at a constant speed, and after a cavity is filled with the molten metal, the pressure control system increases certain pressure under the original filling pressure in the crucible 2 for 3-5 min; immediately maintaining the pressure to make the casting crystallize and solidify under stable pressure; after the casting is solidified, the air pressure in the crucible 2 is discharged, and after the casting is cooled, the casting is taken out through the lifting mechanism 4.

In the description of the present invention, it is to be understood that the terms "center", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be taken as limiting the scope of the present invention.

While the invention has been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.