Extrusion casting machine adopting electromagnetic pump for low-pressure mold filling

Abstract

The utility model discloses an extrusion casting machine adopting an electromagnetic pump for low-pressure mold filling. The extrusion casting machine comprises an electromagnetic pump mold filling system, a mold, a sealing and extrusion composite device, a mold locking device, a mold moving device, a guide column, a heat preserving furnace and a lifting mechanism, the lower die is connected with a static template, and the upper die is connected with a movable template; a piston rod of the mold moving device is connected with the movable template; the mold locking device and the sealing and extruding composite oil cylinder are mounted on the movable mold plate; the lower end of the guide pillar is fixed on the static template and penetrates through the center of the mold locking device; the heat preserving furnace is positioned below the static template; the electromagnetic pump mold filling system is fixed on the heat preserving furnace; the electromagnetic pump mold filling system is tightly connected with a lower mold of the mold through a liquid rising pipe; a sealing extrusion composite punch is mounted at the free end of an extrusion piston rod assembly of the sealing extrusion composite oil cylinder; a liquid inlet of the lower mold is communicated with a liquid outlet of the heat preservation furnace through a liquid rising pipe and an electromagnetic pump mold filling system in sequence; the heat preservation furnace comprises a soup adding chamber far away from the liquid outlet, and the soup adding chamber communicates with the liquid outlet through a communicating vessel.

Description

Technical Field

[0001] This utility model belongs to the field of low-pressure casting, and in particular relates to a squeeze casting machine that uses an electromagnetic pump for low-pressure filling. Background Technology

[0002] Traditional low-pressure casting equipment uses a direct filling method with a pressure furnace, resulting in low filling pressure, stable and controllable filling speed, and sufficient venting of the mold cavity. However, low-pressure casting equipment has the following shortcomings:

[0003] 1. Low casting pressure leads to insufficient casting density: In the traditional low-pressure casting process, the filling pressure is relatively low (usually no more than 0.1MPa), which limits the pressure gradient when the molten metal flows in the mold, making it difficult to fully compact the molten metal during the filling process.

[0004] 2. The casting has a rough appearance and thick walls, requiring extensive post-processing: This is mainly due to factors such as poor cooling conditions. Subsequent surface treatment technologies, such as electrochemical polishing, are needed, resulting in high manufacturing costs.

[0005] 3. Gas seeps into the molten aluminum during the pressurization process of the pressure furnace, causing an increase in the gas content of the molten aluminum: This is because during the pressurization process, oxygen in the air and impurities in the molten aluminum can easily mix into the casting to form bubbles, affecting product quality.

[0006] 4. Repeated pressurization in the pressure furnace causes a large amount of oxide slag to form on the surface of the molten aluminum: Frequent opening and closing of the gas valve will cause the molten aluminum to be exposed to the air for a long time, which will accelerate the oxidation reaction rate on its surface and generate a large amount of slag.

[0007] 5. Temperature and volume changes caused by the compressibility of compressed air lead to pressure fluctuations: Given the physical properties of gases, it is difficult for them to maintain a constant pressure value like liquids. Therefore, effective measures must be taken to mitigate this problem. Summary of the Invention

[0008] To address the aforementioned technical problems, this utility model discloses a squeeze casting machine employing a low-pressure filling method using an electromagnetic pump. This improves the density of the castings, reduces porosity and looseness caused by the incorporation of gases and oxide slag, and also reduces the surface roughness and post-processing workload.

[0009] To achieve the above objectives, the technical solution adopted by this utility model is as follows: an extrusion casting machine using a low-pressure electromagnetic pump for filling, mainly comprising the following parts: an electromagnetic pump filling system, a mold, a sealing extrusion composite device, a mold locking device, a mold moving device, a guide column, a heat preservation furnace, and a lifting mechanism.

[0010] The mold includes an upper mold and a lower mold. The lower mold is connected to the stationary template, and the upper mold is connected to the moving template. The mold moving device includes a piston rod and a cylinder. The piston rod is connected to the moving template, and the cylinder is connected to the stationary template. The mold locking device and the sealing extrusion composite hydraulic cylinder are installed on the moving template. The lower end of the guide pillar is fixed on the stationary template and passes through the center of the mold locking device. The heat preservation furnace is located below the stationary template, and the electromagnetic pump filling system is fixed on the heat preservation furnace. The electromagnetic pump filling system is tightly connected to the lower mold of the mold through a riser pipe.

[0011] A sealing and extrusion compound punch is installed at the free end of the extrusion piston rod assembly of the sealing and extrusion compound cylinder. The sealing and extrusion compound punch is inserted into the through hole of the upper die. The upper part of the sealing and extrusion compound punch matches the shape of the through hole, and a gap is left between the lower part of the sealing and extrusion compound punch and the through hole. The lower part of the sealing and extrusion compound punch matches the shape of the liquid inlet.

[0012] The liquid inlet of the lower mold is connected to the liquid outlet of the heat preservation furnace in sequence through the riser pipe and the electromagnetic pump filling system; the heat preservation furnace includes a soup adding chamber far away from the liquid outlet, which is connected to the liquid outlet through a connector.

[0013] Furthermore, a cavity is formed between the upper and lower molds, and a casting slag collection bag is provided at the junction of the upper and lower molds. Several mold venting channels are connected above the casting slag collection bag.

[0014] Furthermore, the electromagnetic pump filling system is an AC electromagnetic pump filling system or a DC electromagnetic pump filling system; the liquid inlet of the lower mold is provided with a mold sprue sleeve, and the upper part of the mold sprue sleeve is provided with an outward boss that mates with the stepped surface of the liquid inlet of the lower mold; the liquid inlet below the mold sprue sleeve is in the shape of an expanding cone from top to bottom.

[0015] Furthermore, the liquid inlet of the lower mold is connected to the ceramic tube through a riser pipe; the lower end of the ceramic tube is connected to the liquid outlet of the holding furnace; an electrode is provided on the outside of the ceramic tube, which passes through the ceramic tube so as to be in contact with the aluminum liquid inside the ceramic tube; the electrode is electrically connected to the electromagnetic pump filling control system through a copper busbar.

[0016] Furthermore, the holding furnace adopts a high-low drop structure. The high-end section is the molten aluminum filling chamber, which has a large cross-sectional area. The furnace door is located above the molten aluminum filling chamber, through which molten aluminum can be added and kept still. The low end is the outlet, which is a small cross-sectional area conical channel, the size of which matches the ceramic tube of the electromagnetic pump, serving as the outlet for molten aluminum. A heating tube is located at the bottom of the molten aluminum filling chamber, responsible for heating and keeping the molten aluminum warm. The molten aluminum filling chamber and the outlet are connected by a communicating vessel to ensure that the molten aluminum level connected to the inlet is the same as the molten aluminum level in the molten aluminum filling chamber.

[0017] Furthermore, at the bottom of the soup adding chamber, on the side away from the furnace door, there is an inclined baffle wall. The outer side of the baffle wall is connected to a horizontally arranged communicating vessel through a downward channel. The communicating vessel is located below the soup adding chamber.

[0018] Furthermore, heating tubes are also installed near the communicating vessel and liquid outlet of the heat preservation furnace.

[0019] Furthermore, the heat preservation furnace is mounted on a lifting mechanism, which is a screw drive mechanism used to adjust the height of the heat preservation furnace so that the plane between the liquid riser pipe and ceramic pipe of the electromagnetic pump filling system and the heat preservation furnace is tightly sealed.

[0020] Furthermore, a positioning protection mechanism is provided at one end of the lifting mechanism.

[0021] Furthermore, at least two mold-moving devices are symmetrically arranged on both sides of the stationary mold plate; at least three guide pillars are provided; and the mold-locking devices D are set independently of each other.

[0022] This invention has the following advantages: by using an electromagnetic pump for filling, the gas content in the casting is reduced and the number of pores is decreased; by using a heat-preserving furnace design, continuous aluminum liquid injection is possible, reducing the generation of impurities in the aluminum liquid and purifying the aluminum liquid by precipitation, resulting in low impurity content in the casting; continuous aluminum liquid injection also improves casting efficiency; and the extrusion casting machine with a sealing and extrusion composite hydraulic cylinder improves the density of the casting. Attached Figure Description

[0023] Figure 1 This is a cross-sectional view of the locked state of a low-pressure extrusion casting machine using an electromagnetic pump, according to an embodiment of this utility model.

[0024] Figure 2 This is a schematic diagram of the aluminum liquid rising in an extrusion casting machine using a low-pressure electromagnetic pump, according to an embodiment of this utility model.

[0025] Figure 3 This is a schematic diagram of the filling process of a squeeze casting machine using a low-pressure filling method with an electromagnetic pump, according to an embodiment of this utility model.

[0026] Figure 4 This is a schematic diagram of the aluminum liquid falling back in an extrusion casting machine using a low-pressure filling with an electromagnetic pump, according to an embodiment of this utility model.

[0027] Figure 5 This is a schematic diagram of a low-pressure extrusion casting machine using an electromagnetic pump, according to an embodiment of this utility model.

[0028] Figure 6 This is a schematic diagram of a low-pressure filling furnace for extrusion casting machines using an electromagnetic pump, according to an embodiment of this utility model.

[0029] Figure 7 This is a cross-sectional view (AA) of the holding furnace of the extrusion casting machine using a low-pressure filling method with an electromagnetic pump, according to an embodiment of this utility model.

[0030] Figure 8This is a perspective view of a low-pressure extrusion casting machine using an electromagnetic pump, according to an embodiment of the present invention.

[0031] In the diagram, A is the electromagnetic pump filling system, A-1 is the electromagnetic pump filling control system, A-2 is the wiring copper busbar, A-3 is the electrode, A-4 is the ceramic tube, A-5 is the riser pipe, B is the mold, C is the sealing and extrusion composite device, D is the mold locking device, E is the mold moving device, F is the guide pillar, G is the holding furnace, G-1 is the broth adding chamber, G-2 is the furnace door, G-3 is the aluminum liquid, G-4 is the heating tube, G-5 is the communicating vessel, G-6 is the lifting mechanism, 1 is the extrusion piston rod assembly, 2 is the sealing and extrusion composite punch, 3 is the upper mold, 4 is the mold cavity, 5 is the lower mold, 6 is the mold sprue sleeve, 7 is the casting slag collection bag, 8 is the mold venting channel, 9 is the static mold plate, and 10 is the moving mold plate. Detailed Implementation

[0032] To facilitate understanding by those skilled in the art, the present invention will be further described below in conjunction with embodiments and accompanying drawings.

[0033] The connection relationship of the low-pressure filling extrusion casting machine using an electromagnetic pump in this embodiment is as follows: Figure 1 , Figure 8 As shown:

[0034] 1. The piston rod of the mold moving device E is connected to the moving template 10, and the cylinder body is connected to the stationary template 9.

[0035] 2. The mold locking device D and the sealing extrusion composite hydraulic cylinder C are installed on the moving template 10.

[0036] 3. The upper mold of mold B is connected to the moving template 10, and the lower mold is connected to the stationary template 9.

[0037] 4. The lower end of the guide post F is fixed on the static template 9 and passes through the center of the mold-locking device D.

[0038] 5. The heat preservation furnace G is located below the static template 9, and the electromagnetic pump filling system A is fixed on the heat preservation furnace G.

[0039] 6. The electromagnetic pump filling system A is tightly connected to the lower mold 5 of mold B through the riser pipe A-5.

[0040] The sealing and extrusion composite cylinder C has a sealing and extrusion composite punch 2 installed at the free end of the extrusion piston rod assembly 1. The sealing and extrusion composite punch 2 is inserted into the through hole of the upper die 3. The upper part of the sealing and extrusion composite punch 2 matches the shape of the through hole, and a gap is left between the lower part of the sealing and extrusion composite punch 2 and the through hole.

[0041] A cavity 4 is formed between the upper mold 3 and the lower mold 5. A casting slag collection bag 7 is provided at the junction of the upper mold 3 and the lower mold 5. The upper part of the casting slag collection bag 7 is connected to the mold exhaust channel 8.

[0042] The liquid inlet of the lower mold 5 is connected to the liquid outlet of the heat preservation furnace G via the riser pipe A-5 and the electromagnetic pump filling system A. The heat preservation furnace G includes a soup adding chamber G-1 located away from the liquid outlet. A furnace door G-2 is located above the soup adding chamber G-1, and a heating pipe G-4 is located at the bottom of the soup adding chamber G-1. The soup adding chamber G-1 is connected to the liquid outlet via a connector G-5.

[0043] The electromagnetic pump filling system A is either an AC electromagnetic pump filling system or a DC electromagnetic pump filling system. The lower mold 5 has a mold sprue sleeve 6 at its inlet. The upper part of the mold sprue sleeve 6 has an outward-facing boss that mates with the stepped surface of the lower mold 5's inlet. The inlet below the mold sprue sleeve 6 has a tapered shape that expands from top to bottom.

[0044] The liquid inlet of the lower mold 5 is connected to the ceramic tube A-4 through the riser pipe A-5; the lower end of the ceramic tube A-4 is connected to the liquid outlet of the holding furnace G. An electrode A-3 is provided on the outside of the ceramic tube A-4, and the electrode A-3 passes through the ceramic tube A-4, so that it can contact the aluminum liquid inside the ceramic tube A-4; the electrode A-3 is electrically connected to the electromagnetic pump filling control system A-1 through the wiring copper busbar A-2.

[0045] like Figure 6-7 As shown, the holding furnace adopts a high-low drop structure. The high-end part is the molten aluminum filling chamber G-1, which has a large cross-sectional area. Above the molten aluminum filling chamber G-1 is the holding furnace door G-2, through which molten aluminum G-3 can be added and kept still. The low end is divided into a liquid outlet, which is a small cross-sectional area conical channel, the size of which matches the ceramic tube of the electromagnetic pump, serving as the output outlet for molten aluminum G-3. The bottom of the molten aluminum filling chamber G-1 is equipped with a heating tube G-4, which is responsible for heating and keeping the molten aluminum warm. The molten aluminum filling chamber and the liquid outlet are connected by a communicating vessel G-5 to ensure that the molten aluminum level P connected to the liquid inlet is at the same height as the molten aluminum level Q in the molten aluminum filling chamber.

[0046] The bottom of the soup adding chamber G-1 has a bowl-shaped structure. The furnace wall on the side near the furnace door G-2 is designed to slope inward. On the side away from the furnace door G-2, there is a sloped baffle. The outer side of the baffle is connected to the horizontally set communicating vessel G-5 through a downward channel. The communicating vessel G-5 is located below the soup adding chamber G-1.

[0047] The holding furnace G is mounted on the lifting mechanism G-6, which is a screw drive mechanism used to adjust the height of the holding furnace to ensure a tight seal between the liquid riser pipe A-5 and ceramic pipe A-4 of the electromagnetic pump filling system A and the holding furnace G. One end of the lifting mechanism G-6 is equipped with a positioning protection mechanism.

[0048] The heating tube G-4 is also installed near the communicating vessel G-5 and the liquid outlet of the heat preservation furnace.

[0049] At least two mold-moving devices E are symmetrically arranged on both sides of the static mold plate 9; at least three guide pillars F are provided, preferably four in this embodiment. The mold-locking devices D are arranged independently of each other.

[0050] Action process:

[0051] 1. For example Figure 1 As shown, the mold moving device E moves the moving platen 10 downward, so that the upper and lower molds 3 and 5 of the mold B come into contact.

[0052] 2. The action of the mold locking device D causes the four guide pillars F to deform, generating sufficient locking force to lock the mold.

[0053] 3. For example Figure 2 As shown, when the control system A-1 of the electromagnetic pump filling system A is started, the electrode A-3 generates a magnetic field after being energized, which generates a thrust on the aluminum liquid in the ceramic tube A-4. Under the action of electromagnetic thrust, the aluminum liquid G-3 slowly rises along the riser tube A-5.

[0054] 4. The aluminum liquid G-3 enters the mold cavity 4 through the mold gate sleeve 6. The air in the mold cavity 4 moves to the outside of the cavity under the push of the aluminum liquid and is discharged into the atmosphere through the slag collection bag 7 and the exhaust channel 8.

[0055] 5. For example Figure 3 As shown, after the molten aluminum fills the mold cavity 4, the control system A-1 of the AC (DC) electromagnetic pump filling system A stops being powered. After electrode A-3 loses power, the magnetic field inside the ceramic tube A-4 disappears, stopping the filling process. Simultaneously, the sealing and extrusion composite device C activates, as shown... Figure 4 As shown, the extrusion piston rod 1 drives the sealing extrusion compound punch 2 to move downward to close the mold gate sleeve 6, so that the mold cavity 4 is isolated from the aluminum liquid in the riser pipe A-5.

[0056] 6. For example Figure 5 As shown, after the mold cavity 4 is isolated from the molten aluminum in the riser tube A-5, the sealing extrusion compound punch 2 continues to move downward. Since the mold cavity is already filled with molten aluminum, the annular area of ​​the sealing extrusion compound punch 2 will generate a 50-100MPa extrusion force on the molten aluminum, causing the molten aluminum in the mold cavity 4 to cool and solidify under high pressure, increasing the density of the casting and reducing defects such as shrinkage cavities and porosity.

[0057] The above embodiments are only for illustrating the technical concept of this utility model and should not be used to limit the protection scope of this utility model. Any modifications made to the technical solution based on the technical concept proposed by this utility model shall fall within the protection scope of this utility model.

Claims

1. An extrusion casting machine using electromagnetic pump low pressure filling, characterized by, The electromagnetic pump filling system, the mold, the sealing extrusion composite device, the locking device, the mold moving device, the guide column, the holding furnace and the lifting mechanism are included. The mold includes an upper mold and a lower mold, and the lower mold is connected to a static mold plate, and the upper mold is connected to a dynamic mold plate; the mold moving device includes a piston rod and a cylinder body, the piston rod is connected to the dynamic mold plate, and the cylinder body is connected to the static mold plate; the locking device and the sealing extrusion composite oil cylinder are installed on the dynamic mold plate; the lower end of the guide column is fixed on the static mold plate and passes through the center of the locking device; the holding furnace is located below the static mold plate, and the electromagnetic pump filling system is fixed on the holding furnace; the electromagnetic pump filling system is tightly connected to the lower mold of the mold through the liquid lifting pipe. The free end of the extrusion piston rod assembly of the sealing extrusion composite oil cylinder is provided with a sealing extrusion composite punch, the sealing extrusion composite punch is inserted into the through hole of the upper mold, the upper part of the sealing extrusion composite punch is matched with the shape of the through hole, and a gap is left between the lower part of the sealing extrusion composite punch and the through hole; the lower part of the sealing extrusion composite punch is matched with the shape of the liquid inlet. The liquid inlet of the lower mold is communicated with the liquid outlet of the holding furnace through the liquid lifting pipe and the electromagnetic pump filling system in sequence; the holding furnace includes a soup adding chamber away from the liquid outlet, and the soup adding chamber is communicated with the liquid outlet through a communicating device.

2. The extrusion casting machine with electromagnetic pump low-pressure filling according to claim 1, wherein: the mold upper mold and the lower mold form a mold cavity between them, and a casting slag collecting bag is arranged at the joint of the upper mold and the lower mold, and a plurality of mold exhaust channels are communicated above the casting slag collecting bag.

3. The extrusion casting machine with electromagnetic pump low-pressure filling according to claim 1, wherein: the liquid inlet of the lower mold is provided with a mold sprue bushing, an outward protrusion is arranged on the upper part of the mold sprue bushing, and the protrusion is matched with the stepped surface of the liquid inlet of the lower mold; the liquid inlet below the mold sprue bushing is in the shape of a downwardly expanding cone.

4. The extrusion casting machine with electromagnetic pump low-pressure filling according to claim 1, wherein: the liquid inlet of the lower mold is communicated with a ceramic pipe through a liquid lifting pipe; the lower end of the ceramic pipe is communicated with the liquid outlet of the holding furnace; an electrode is arranged outside the ceramic pipe, the electrode passes through the ceramic pipe and can contact the aluminum liquid inside the ceramic pipe; the electrode is electrically connected to the electromagnetic pump filling control system through a copper bus.

5. The extrusion casting machine with electromagnetic pump low-pressure filling according to claim 1 or 4, wherein: the holding furnace adopts a high-low difference structure, the high-end part is a soup adding chamber with a large cross-sectional area structure, a holding furnace door is arranged above the soup adding chamber, the aluminum liquid can be added through the holding furnace door, and the aluminum liquid can be static in the holding furnace door; the low-end part is a liquid outlet with a small cross-sectional area conical channel, the size of the liquid outlet is matched with the ceramic pipe of the electromagnetic pump, and the liquid outlet serves as an aluminum liquid output outlet, a heating pipe is arranged at the bottom of the soup adding chamber and is responsible for heating and keeping the aluminum liquid; the soup adding chamber and the liquid outlet are connected by a communicating device to ensure that the liquid level of the aluminum liquid communicated to the liquid inlet is equal to the liquid level of the aluminum liquid in the soup adding chamber.

6. The extrusion casting machine with electromagnetic pump low-pressure filling according to claim 5, wherein: an inclined baffle is arranged at the position of the bottom of the soup adding chamber on the side away from the holding furnace door, the baffle is communicated with a horizontally arranged communicating device through a downward channel, and the communicating device is located below the soup adding chamber. ​ ​ ​ ​ ​ ​ 7. The squeeze casting machine with electromagnetic pump low-pressure filling according to claim 5, characterized in that: The heat preservation furnace is provided with heating pipes near the communicating vessel and the liquid outlet.

8. The squeeze casting machine with electromagnetic pump low-pressure filling according to claim 1, characterized in that: The heat preservation furnace is arranged on a lifting mechanism, which is a screw transmission mechanism for adjusting the height of the heat preservation furnace to tightly seal the plane between the lifting mechanism, the ceramic pipe and the heat preservation furnace.

9. The squeeze casting machine with electromagnetic pump low-pressure filling according to claim 8, characterized in that: One end of the lifting mechanism is provided with a position protection mechanism.

10. The squeeze casting machine with electromagnetic pump low-pressure filling according to claim 1, characterized in that: The mold moving device is symmetrically provided with at least two on both sides of the static mold plate; the guide column is provided with at least three; and the mold locking devices D are independently arranged.

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