阅读说明：本技术 一种大型铝合金零件挤压铸造的供液方法及其装置 (Liquid supply method and device for extrusion casting of large aluminum alloy parts ) 是由 游东东 朱谦 张卫文 李风雷 于 2019-10-30 设计创作，主要内容包括：本发明涉及一种大型合金零件挤压铸造的供液方法及其装置。所述装置包括大容量熔化炉、自动机械手、坩埚式熔化保温炉、保温炉、传输管道和电磁泵；保温炉与铸造的压室之间通过传输管道连接,电磁泵安装在保温炉出口与传输管道入口的连接处；自动机械手将大容量熔化炉中的液态金属转移至坩埚式熔化保温炉,坩埚式熔化保温炉连接自动倾斜单元,且自动倾斜单元将坩埚式熔化保温炉中液态金属自动转移至保温炉中。所述装置结构简便、自动化程度高,稳定性好,工艺设计巧妙。金属在除气后半小时内得到利用,保证生产用金属液的质量；输液管道采用分段式连接设计,便于保护压室,方便设备的故障维修和维护保养。(The invention relates to a liquid supply method and a liquid supply device for extrusion casting of large alloy parts. The device comprises a large-capacity melting furnace, an automatic manipulator, a crucible type melting holding furnace, a transmission pipeline and an electromagnetic pump; the heat preservation furnace is connected with the cast pressure chamber through a transmission pipeline, and the electromagnetic pump is arranged at the joint of the heat preservation furnace outlet and the transmission pipeline inlet; the automatic manipulator transfers the liquid metal in the large-capacity melting furnace to the crucible type melting holding furnace, the crucible type melting holding furnace is connected with the automatic tilting unit, and the automatic tilting unit automatically transfers the liquid metal in the crucible type melting holding furnace to the holding furnace. The device has the advantages of simple structure, high automation degree, good stability and ingenious process design. The metal is utilized within half an hour after degassing, so that the quality of the molten metal for production is ensured; the infusion pipeline adopts a sectional type connection design, so that the pressure chamber is protected conveniently, and the fault maintenance and the maintenance of equipment are facilitated.)

1. A liquid supply device for extrusion casting of large aluminum alloy parts is characterized by comprising a large-capacity melting furnace (1), an automatic manipulator (2), a crucible type melting holding furnace (3), a holding furnace (4), a transmission pipeline (6) and an electromagnetic pump (5); the heat preservation furnace (4) is connected with the cast pressure chamber (7) through a transmission pipeline (6), and the electromagnetic pump (5) is arranged at the joint of the outlet of the heat preservation furnace (4) and the inlet of the transmission pipeline (6); the automatic manipulator transfers the liquid metal in the large-capacity melting furnace to the crucible type melting holding furnace, the crucible type melting holding furnace (3) is connected with the automatic inclination unit (8), and the automatic inclination unit (8) automatically transfers the liquid metal in the crucible type melting holding furnace (3) to the holding furnace (4).

2. The liquid supply apparatus according to claim 1, wherein the automatic tilting unit (8) is a T-shaped threaded jacking linkage controlled by a motor.

3. A liquid supply apparatus as claimed in claim 1, wherein an automatic degassing unit is installed on a lid (17) of the crucible type melting and holding furnace (2).

4. The liquid supply apparatus as claimed in claim 3, wherein the automatic degassing unit is a graphite rotor controlled by a motor, the graphite rotor being inserted into the crucible type melting and holding furnace.

5. The liquid supply device of claim 1, wherein the conveying pipeline (5) is detachably connected in sections, and the holding furnace (4) is a pool type reverberatory furnace.

6. The liquid supply device according to claim 1, characterized in that the liquid supply device further comprises a moving guide rail (9), a bracket (10) and a holding furnace tray (12), the crucible type melting holding furnace (3) and the automatic tilting unit (8) are installed on the bracket (10) with a guide wheel (11) arranged at the bottom, the holding furnace (4) is installed on the tray (12) with a guide wheel arranged at the bottom, and the crucible type melting holding furnace bracket (10) and the holding furnace tray (12) are movable on the rail (9).

7. The liquid supply device according to claim 3, further comprising a first liquid level sensor (13) disposed in the holding furnace (4), a second liquid level sensor (15) disposed in the crucible type melting holding furnace (3), and a PLC controller (14), wherein the automatic tilting unit (8), the automatic manipulator (2), the electromagnetic pump (5), the automatic degassing unit, and both the liquid level sensors are electrically connected to the PLC controller (14).

8. The liquid supply device of claim 1, wherein the effective volume of the holding furnace (4) is 10 ~ 15 parts, the effective volume of the crucible type melting holding furnace (3) is 1-2 times of that of the holding furnace, and the effective volume of the large-capacity melting furnace (1) is 8 ~ 10 times of that of the holding furnace (4).

9. The method for supplying liquid by using the liquid supply apparatus as claimed in any one of claims 1 to 8, wherein the molten liquid metal in the large-capacity melting furnace (1) is poured into the crucible type melting and holding furnace (3) by means of the robot (2), the degassing unit degasses the metal in the crucible type melting and holding furnace, the automatic tilting unit (8) then acts on the crucible type melting and holding furnace (3) to transfer the liquid metal into the holding furnace (4), nitrogen is introduced into the holding furnace (4) to protect the liquid metal, and then the liquid metal in the holding furnace (4) is introduced into the pressure chamber (7) by means of the electromagnetic pump (5).

Technical Field

The invention relates to extrusion casting, in particular to a liquid supply method and a liquid supply device for extrusion casting of large aluminum alloy parts.

Background

The extrusion casting is also called liquid forging, and the process is that a certain liquid or semi-solid metal is poured into a die cavity of a die, and an extrusion punch acts on the liquid metal with a certain extrusion force to fully crystallize, solidify and form the liquid metal, so that a material net accurate forming method of parts with required shapes is obtained. By this process, the liquid metal is solidified under high pressure, and a heat-treatable, highly dense casting is obtained. Indirect extrusion casting, among other things, can produce large, complex, dimensionally accurate parts, representing a major development in extrusion casting.

The existing indirect extrusion casting forming method mainly adopts a mechanical arm provided with a ladle or a method for manually holding liquid metal to pour into a pressure chamber, and has the following obvious defects and shortcomings:

1) a ladle is used for containing metal melt from a crucible and pouring the metal melt from a pressure chamber opening, the liquid metal is exposed in the air and is easy to oxidize, and the pouring amount of the liquid metal is difficult to accurately control;

2) the metal melt is contained in the crucible by the ladle, and is directly contacted with the ladle without heat preservation measures and exposed in the air, so that a large amount of heat is lost and is far different from the preset pouring temperature;

3) in order to prevent quality defects caused by temperature reduction of liquid metal before injection, the smelting temperature of the liquid metal needs to be increased, or a pressure chamber heating system is additionally arranged, so that the energy consumption is high;

4) liquid metal is poured into the pressure chamber from top to bottom, so that gas and inclusions are easily involved;

5) the existing indirect extrusion casting equipment has the defects that all devices are fixed in position and difficult to move, and the trouble repair and maintenance of the equipment are difficult.

The invention patent CN200910041401.0 discloses an indirect extrusion casting method and device for filling liquid metal into a mold cavity by utilizing the electromagnetic force, the method enables the liquid metal to be transmitted and filled through a closed transmission pipeline, and oxidation and air suction are effectively reduced when the metal liquid is filled. However, the method still adopts the traditional liquid supply mode, and the metal is injected into the device in the traditional mode after being melted in the melting furnace, and the problems of heat loss, oxidation, air suction and the like still exist. In the Chinese patent CN200310111172.8, a quantitative pouring device on the pressure chamber side is designed in the process of indirect extrusion casting by using a vertical press. By adopting the pouring mode, the pouring process is not influenced by opening and closing the die, so that the production efficiency is improved. However, when the device is used for pouring, the liquid metal is poured into the pressure chamber from a high position by utilizing gravity, and gas and inclusions are still easily involved; the pressure chamber needs to store all liquid metal, when large parts are produced, the movement distance of the extrusion punch is long, friction and abrasion between the pressure chamber and the extrusion punch can be increased, and the service life of the pressure chamber and the extrusion punch is shortened.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a liquid supply device and a liquid supply method for extrusion casting of large-scale aluminum alloy parts, which are closed, automatic, high in efficiency, good in quality and high in safety performance.

In order to achieve the above object, the present invention adopts at least one of the following aspects.

A liquid supply device for extrusion casting of large aluminum alloy parts comprises a large-capacity melting furnace, an automatic manipulator, a crucible type melting holding furnace, a transmission pipeline and an electromagnetic pump; the heat preservation furnace is connected with the cast pressure chamber through a transmission pipeline, and the electromagnetic pump is arranged at the joint of the heat preservation furnace outlet and the transmission pipeline inlet; the automatic manipulator transfers the liquid metal in the large-capacity melting furnace to the crucible type melting holding furnace, the crucible type melting holding furnace is connected with the automatic tilting unit, and the automatic tilting unit automatically transfers the liquid metal in the crucible type melting holding furnace to the holding furnace.

Further, the automatic tilting unit is a T-shaped thread jacking link mechanism controlled by a motor.

Further, an automatic degassing unit is arranged on a furnace cover of the crucible type melting holding furnace.

Furthermore, the automatic degassing unit is a graphite rotor controlled by a motor, the graphite rotor is inserted into the crucible type melting and heat preserving furnace, and the graphite rotor enters liquid metal to rotate so as to enable hydrogen to float out.

Furthermore, the transmission pipelines are detachably connected in sections, and the heat preservation furnace adopts a pool type reverberatory furnace.

Furthermore, the liquid supply device also comprises a movable guide rail, a support and a holding furnace tray, the crucible type melting holding furnace and the automatic inclination unit are arranged on the support with the guide wheel arranged at the bottom, the holding furnace is arranged on the tray with the guide wheel arranged at the bottom, and the crucible type melting holding furnace support and the holding furnace tray can move on the movable rail. The movable guide rail is fixed on the ground through threads, so that the flexible movement of the holding furnace and the crucible type melting holding furnace is realized.

Further, the liquid supply device further comprises a first liquid level sensor, a second liquid level sensor and a PLC (programmable logic controller), the first liquid level sensor is arranged in the heat preservation furnace, the second liquid level sensor is arranged in the crucible type melting heat preservation furnace, and the automatic inclination unit, the automatic mechanical arm, the electromagnetic pump, the automatic degassing unit and the two liquid level sensors are all electrically connected with the PLC.

Further, the large-capacity melting furnace is determined according to the amount of castings required to be produced, the capacity of the holding furnace is as small as possible under the condition that continuous supply is guaranteed, the solution is utilized within a short time after degassing, the quality of the molten liquid for production is guaranteed, and discharging and moving are convenient.

When the device is used for liquid supply, the automatic mechanical arm is used for scooping up the liquid metal melted in the large-capacity melting furnace and injecting the liquid metal into the crucible type melting heat preservation furnace, the automatic degassing unit is used for degassing the metal in the crucible type melting heat preservation furnace, then the automatic inclination unit acts on the crucible type melting heat preservation furnace, the liquid metal is transferred into the heat preservation furnace, nitrogen is introduced into the heat preservation furnace to protect the liquid metal, and then the liquid metal in the heat preservation furnace is led into the pressure chamber through the electromagnetic pump.

A liquid supply method for extrusion casting of large aluminum alloy parts comprises three liquid supply stages, wherein in the first stage, a large amount of liquid metal melted in a melting furnace is injected into a crucible type melting and heat preserving furnace and is degassed; the second stage is that the crucible type melting holding furnace is poured into the holding furnace in an inclined mode; and the third stage is that the electromagnetic pump is used to introduce the liquid metal in the holding furnace into the pressure chamber via electromagnetic force, and finally the filling extrusion is performed, and the liquid supply is stopped when the filling is completed.

The liquid supply method for extrusion casting of the large aluminum alloy part is automatically controlled by plc in three liquid supply stages except for the first liquid supply, wherein the first liquid supply means that all solutions are in a large-capacity melting furnace when the extrusion casting equipment starts to work, and no solutions exist in a crucible type melting holding furnace and a holding furnace. When the liquid metal in the holding furnace is reduced to a half, a liquid level sensor in the holding furnace transmits a signal to a plc control box to start a tilting device of the crucible type melting holding furnace, and the crucible type melting holding furnace tilts to convey the liquid metal into the holding furnace. When the solution height in the holding furnace reaches the set maximum value, a liquid level sensor in the holding furnace transmits a signal to a plc control box to stop the tilting device of the crucible type melting holding furnace. Compiling a plc program to make the signal of the liquid level sensor in the crucible type melting and heat preserving furnace inactive when the tilting device is opened; when the liquid metal in the crucible type melting and heat preserving furnace is reduced to a half, a liquid level sensor in the crucible type melting and heat preserving furnace transmits a signal to a plc control box to start a manipulator, the large-capacity melting furnace conveys the liquid metal to the crucible type melting and heat preserving furnace, and when the height of the solution in the crucible type melting and heat preserving furnace reaches a set maximum value, the liquid level sensor in the crucible type melting and heat preserving furnace transmits a signal to the plc control box to close the manipulator.

Compared with the prior art, the invention has the following outstanding advantages:

1. the method of the invention uses three furnaces to respectively perform their own functions and operate in a production line mode, and compared with a single melting furnace, the method can ensure high-efficiency supply and sufficient liquid metal supply;

2. the device of the invention ensures that the liquid metal is in a closed state in the liquid supply process, avoids contacting with air, and solves the problems of oxidation, air suction and heat loss of the liquid metal in the supply process; the liquid metal is utilized within half an hour after degassing, so that the quality of the metal liquid for production is ensured;

3. the capacity of the heat preservation furnace is small, about 10 parts are produced from each furnace of liquid metal, the residence time of the liquid metal in the heat preservation furnace is not long, and nitrogen is introduced into the heat preservation furnace for protection.

4. The installation position of the device is very flexible, the installation position of the device can be adjusted according to different equipment and conditions, and the direction of the track can be changed along with the adjustment; the device has the advantages of simple structure, high automation degree, good stability, ingenious process design and reasonable structural design.

5. If abnormity occurs or an emergency occurs in the test or production process, liquid supply can be stopped immediately, and because the capacity of the holding furnace is small, all aluminum liquid can be discharged immediately and returned to the large-capacity melting furnace for recycling, and after the fault is relieved, the crucible type melting holding furnace can continue to provide liquid metal for recovery production;

6. the heat preservation furnace close to the extrusion casting equipment and the crucible type melting heat preservation furnace can move through the tracks, and the liquid conveying pipeline adopts a detachable sectional type connection design, so that the pressure chamber and the equipment can be protected conveniently for fault maintenance and repair.

Drawings

FIG. 1 is a schematic structural view of an apparatus for squeeze casting a large aluminum alloy part;

wherein: 1-large capacity melting furnace; 2-automatic manipulator; 3-crucible type melting holding furnace; 4, a holding furnace; 5, an electromagnetic pump; 6, conveying a pipeline; 7-pressure chamber; 8-automatic tilting unit; 9-a guide rail; 10-crucible type melting holding furnace support; 11-a guide wheel; 12-holding furnace tray; 13-a first level sensor; 14-plc controller; 15-a second liquid level sensor; 16-a graphite rotor; and 17, covering the furnace.

FIG. 2 is a schematic view showing degassing of the crucible type melting and holding furnace of the present invention.

Detailed Description

The following further describes embodiments of the present invention in conjunction with the following examples and figures, but the practice of the present invention is not limited thereto.

The embodiment supplies liquid to a 250T aluminum alloy indirect extrusion casting device, and the specific structure of the liquid supply device is shown in figure 1. The device comprises a large-capacity melting furnace 1, an automatic manipulator 2, a crucible type melting holding furnace 3, a holding furnace 4, a movable guide rail 9, a transmission pipeline 6, an electromagnetic pump 5, a first liquid level sensor 13, a plc controller 14 and a second sensor 15. The coupling relationship between them and the casting machine is as follows: the three furnaces and the pressure chamber 7 are arranged on the same straight line; the large-capacity melting furnace 1 is arranged at the left side of the crucible type melting holding furnace 3; the automatic manipulator 2 is arranged between the large-capacity melting furnace 1 and the crucible type melting holding furnace 3; the crucible type melting holding furnace 3 is arranged at the left side of the holding furnace 4; the holding furnace 4 is connected with a pressure chamber 7 of the casting machine through a detachable transmission pipeline 6, and the electromagnetic pump 5 is arranged at the joint of the outlet of the holding furnace 4 and the inlet of the transmission pipeline 6; a liquid level sensor is respectively arranged in the crucible type melting holding furnace 3 and the holding furnace 4; the holding furnace 3 and the crucible type melting holding furnace 4 are arranged on a tray 12 with a guide wheel and a support 10, and then are arranged on a movable guide rail 9, and the movable guide rail 9 is fixed on the ground through threads, so that the flexible movement of the holding furnace 4 and the crucible type melting holding furnace 3 is realized.

The crucible type melting holding furnace 3 is connected with an automatic tilting unit, and the automatic tilting unit automatically transfers the liquid metal in the crucible type melting holding furnace 3 into the holding furnace 4; an automatic degassing unit is arranged on a furnace cover 17 of the crucible type melting holding furnace 2, the automatic degassing unit is a graphite rotor 16 controlled by a motor, and the graphite rotor 16 is inserted into the crucible type melting holding furnace 3 (as shown in figure 2). The automatic manipulator 2, the automatic inclination unit 8 of the crucible type melting holding furnace, the electromagnetic pump 5 and the liquid level sensor are electrically connected with a plc controller 14; the holding furnace 4 adopts a tank type reverberatory furnace.

The automatic tilting unit 8 is a T-shaped thread jacking connecting rod mechanism controlled by a motor, and the T-shaped thread jacking connecting rod mechanism consists of a connecting rod, a T-shaped screw rod, a speed reduction driving unit and a motor. The speed reduction driving unit is connected with the motor and fixed on the support, the crucible type melting holding furnace 3 is connected on the support through the arranged rotating shaft, one end of the connecting rod is rigidly fixed on the crucible type melting holding furnace 3 and is fixedly connected with the rotating shaft, the other end of the connecting rod is connected with the T-shaped screw rod through the rotating shaft, the T-shaped screw rod is connected with the speed reduction driving unit through a T-shaped nut, the motor drives the T-shaped screw rod to move up and down through the speed reduction driving unit, and the T-shaped screw rod moves up and down to drive the connecting rod to rotate around the axis of the rotating shaft, so that the inclination of the crucible type melting holding furnace is realized.

In this example, two kg of liquid metal are required for producing one aluminum alloy sheet, the maximum capacity of the holding furnace 4 is 30 kg, the maximum capacity of the crucible type melting holding furnace 3 is 60 kg, and the maximum capacity of the large capacity melting furnace 1 is 250 kg. The preset maximum capacity of the holding furnace in this example is 20 kg, and the preset maximum capacity of the crucible type melting holding furnace is 60 kg.

The process flow of the embodiment is as follows:

(1) putting the aluminum alloy material into a large-capacity melting furnace, and melting the furnace opening material;

(2) preheating the mold to 280 ℃, cleaning the surfaces of the fixed mold and the movable mold, spraying the paint, closing the mold by using a mold closing oil cylinder of a casting machine, and applying mold locking force to the mold. Turning on the plc controller;

(3) the plc controller 14 starts the automatic manipulator 2, conveys aluminum liquid from the large-capacity melting furnace 1 to the crucible type melting holding furnace 3, and stops the automatic manipulator 2 when the solution reaches the maximum capacity of the preset crucible type melting holding furnace;

(4) when the solution reaches the maximum capacity of the crucible type melting holding furnace 3, a second liquid level sensor 15 in the crucible type melting holding furnace 3 transmits a signal, so that a plc controller 14 starts an automatic degassing device to degas the liquid in the crucible type melting holding furnace 3;

(5) the plc controller 14 starts the automatic tilting unit 8 of the crucible type melting holding furnace 3, conveys aluminum liquid from the crucible type melting holding furnace 3 to the holding furnace 4, stops the automatic tilting unit 8 when the solution reaches the maximum capacity of the preset holding furnace 4, and introduces nitrogen into the holding furnace 4 to protect liquid metal;

wherein, the step 3-5 is the first liquid supply, and the step 3 and the step 4 are both carried out by manually operating a plc controller to control the mechanical arm and the tilting device to convey the liquid metal.

(6) Starting an electromagnetic pump 5, and conveying liquid from the holding furnace 4 to a pressure chamber 7 through a transmission pipeline 6;

(7) performing mold filling and extrusion on the casting machine;

(8) and taking out the casting. Cleaning the surfaces of the fixed die and the movable die, spraying a coating, closing the dies by utilizing a die closing oil cylinder of a casting machine, and applying a die locking force to the dies;

(9) repeating the steps from the 6 th step, and carrying out the next working cycle;

(10) when the liquid metal in the holding furnace 4 is reduced to half, a first liquid level sensor 13 in the holding furnace 4 sends a signal to a plc controller 14 to start a tilting device of the crucible type melting holding furnace 3, and the crucible type melting holding furnace 3 tilts to convey the liquid metal into the holding furnace 4. When the liquid level in the holding furnace 4 reaches the set maximum value, the liquid level sensor in the holding furnace 4 transmits a signal to the plc controller 14 to stop the tilting device of the crucible type melting holding furnace 3;

(11) when the liquid metal in the crucible type melting holding furnace 3 is reduced to a half, the second liquid level sensor 15 in the crucible type melting holding furnace 3 transmits a signal to the plc controller 14 to start the automatic manipulator 2, the large-capacity melting furnace 1 conveys the liquid metal into the crucible type melting holding furnace 3, and when the liquid level in the crucible type melting holding furnace 3 reaches a set maximum value, the liquid level sensor in the crucible type melting holding furnace 3 transmits a signal to the plc controller 14 to close the automatic manipulator 2.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Any equivalent alterations, modifications or improvements made by those skilled in the art to the above-described embodiments using the technical solutions of the present invention are still within the scope of the technical solutions of the present invention.