Low-pressure casting machine with casting and forging mechanism and casting method

Abstract

The invention discloses a low-pressure casting machine with a casting and forging mechanism and a casting method. The low-pressure casting machine with the casting and forging mechanism comprises an air pressure feeding device, a mold and a sealing and extruding composite device. The mold comprises an upper mold and a lower mold, and a cavity is formed between the upper mold and the lower mold; the upper die is provided with a through hole, and the lower die is provided with a liquid inlet communicated with the riser tube; the air pressure feeding device is communicated with a lower die of the die through a liquid rising pipe; the sealing extrusion composite device comprises an extrusion piston rod and a sealing extrusion composite punch; the top of the sealing extrusion composite punch is a connecting part for mounting, the middle is an extrusion part, and the lower part is a sealing part; the sealing extrusion composite punch can do reciprocating motion in the through hole; the outer wall of the extrusion part is matched with the inner wall of the through hole, the outer wall of the sealing part is matched with the inner wall of the liquid inlet, and the diameter of the extrusion part is smaller than that of the extrusion part; a slag collecting bag is arranged on the outer periphery of the cavity, and an exhaust channel communicated with the outside of the mold is arranged above the slag collecting bag; the exhaust channel is kept in a communicated state.

Description

Technical Field

[0001] The invention belongs to the field of low-pressure casting, and in particular relates to a low-pressure casting machine with a casting and forging mechanism and a casting method. Background Art

[0002] Low-pressure casting is a method of obtaining castings by pressing molten metal into a mold cavity from bottom to top with gas pressure and solidifying it under pressure. Compared with die casting, the pressure used is lower (generally 0.02-0.06MPa), so it is called low-pressure casting.

[0003] The process is as follows: pour the smelted molten metal into the crucible of the resistance insulation furnace, install the sealing cover, liquid riser and casting mold. Dry compressed air is introduced above the crucible surface, and the molten metal rises steadily from the liquid riser under this pressure, and is injected into and fills the mold cavity. The molten metal in the casting mold solidifies under pressure until it is completely solidified. Remove the liquid surface pressure, and the molten metal in the liquid riser flows back to the crucible under the action of gravity. Open the casting mold and take out the casting.

[0004] The traditional low-pressure casting equipment uses a direct filling method of a gas pressure furnace, which has low filling pressure, stable and controllable filling speed, and sufficient exhaust of the mold cavity. However, this method also has its shortcomings: 1. Due to the low specific pressure of the casting, the density of the casting is insufficient, which is prone to produce pores, shrinkage holes or shrinkage. 2. The casting has a rough appearance and thick walls, and the post-processing is large, which increases the casting cost. Summary of the invention

[0005] In view of the above technical problems, the present invention discloses a low-pressure casting machine with a casting and forging mechanism and a casting method, aiming to improve the density and surface smoothness of the casting.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a low-pressure casting machine with a casting and forging mechanism, which mainly includes a pneumatic feeding device A; a mold B; and a sealing and extrusion composite device C.

[0007] The mold B includes an upper mold 3 and a lower mold 5, and a cavity 4 is formed between the upper mold 3 and the lower mold 5. The upper mold 3 is provided with a through hole, and the lower mold 5 is provided with a liquid inlet connected to a liquid riser 10. The pneumatic feeding device A is connected to the lower mold 5 of the mold B through the liquid riser 10.

[0008] The sealing extrusion composite device C comprises an extrusion piston rod 1 and a sealing extrusion composite punch 2 installed at the end of the extrusion piston rod 1. The top of the sealing extrusion composite punch 2 is a connection part for installation, the middle part is an extrusion part, and the lower part is a sealing part. The sealing extrusion composite punch 2 can reciprocate in the through hole. The outer wall of the extrusion part matches the inner wall of the through hole, the outer wall of the sealing part matches the inner wall of the liquid inlet, and the diameter of the sealing part is smaller than the diameter of the extrusion part.

[0009] Furthermore, the upper mold 3 is connected to the movable mold plate 14, and the lower mold 5 is connected to the static mold plate 13. The air pressure feeding device A is located below the static mold plate 13. It also includes a clamping device D and a guide column F; the clamping device D is installed on the movable mold plate 14. The lower end of the guide column F is fixed on the static mold plate 13 and passes through the center hole of the clamping device D.

[0010] Furthermore, it also includes a mold shifting device E, a piston rod of the mold shifting device E is connected to the movable mold plate 14, and a cylinder body of the mold shifting device E is relatively fixed to the static mold plate 13.

[0011] Furthermore, the sealing extrusion composite device C comprises a sealing extrusion composite oil cylinder, which is relatively fixed to the movable platen 14 .

[0012] Furthermore, the liquid inlet includes a lower mold opening and a mold gate sleeve 6 installed at the lower mold opening.

[0013] Furthermore, the upper die 3 and the movable die plate 14 are detachably connected, and the sealing extrusion composite punch 2 and the extrusion piston rod 1 are detachably connected.

[0014] Furthermore, a slag collecting bag 7 is provided at the outer periphery of the cavity 4, and an exhaust channel 8 connected to the outside of the mold B is provided above the slag collecting bag 7. The exhaust channel 8 remains connected. The connection between the slag collecting bag and the cavity is located at the lower part of the slag collecting bag, and no less than 3 exhaust channels are provided, including a corrugated passage.

[0015] The present invention also discloses a low-pressure casting method with a casting and forging mechanism. Using the low-pressure casting machine with the casting and forging mechanism, the action process includes:

[0016] The upper mold 3 and the lower mold 5 of the mold B are molded together;

[0017] The air pressure feeding device A is pressurized through the air inlet channel 9, and the molten metal 12 rises along the riser pipe 10 under the action of pressure; it enters the cavity through the liquid inlet of the lower mold 5, and the air in the cavity moves to the outside of the cavity under the push of the molten metal, and is discharged into the atmosphere through the slag collecting bag 7 and the exhaust channel 8;

[0018] When the molten metal fills the cavity, the air inlet channel 9 stops pressurizing the air pressure feeding device A, and the exhaust channel 8 of the air pressure feeding device A opens to exhaust. At the same time, the sealing and extruding composite device C is activated, and the extruding piston rod 1 drives the sealing and extruding composite punch 2 to move downward, and the sealing part closes the liquid inlet, so that the cavity 4 is isolated from the air pressure feeding device A.

[0019] The sealing and extruding composite punch continues to move downward, and the extrusion part generates an extrusion force on the molten metal, so that the molten metal in the mold cavity 4 is cooled and solidified under high pressure, thereby increasing the density of the casting and reducing defects such as shrinkage cavities and looseness.

[0020] Furthermore, the extrusion part exerts an extrusion pressure of 50-100 MPa on the molten metal.

[0021] Furthermore, the upper mold is connected to the movable mold plate, and the lower mold is connected to the static mold plate; the pneumatic feeding device is located below the static mold plate; the clamping device is installed on the movable mold plate; the lower end of the guide pillar is fixed on the static mold plate and passes through the center hole of the clamping device; the piston rod of the mold shifting device is connected to the movable mold plate, and the cylinder body of the mold shifting device is relatively fixed to the static mold plate; the mold shifting device moves the movable mold plate downward to close the upper and lower molds of the mold; the action of the clamping device causes the guide pillar to deform to generate sufficient locking force, thereby locking the mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the mold closing state of a low-pressure casting machine with a casting and forging mechanism according to an embodiment of the present invention.

[0023] Figure 2 It is a schematic diagram of the rising of molten metal in a low-pressure casting machine with a casting and forging mechanism according to an embodiment of the present invention.

[0024] Figure 3 It is a schematic diagram of a low-pressure casting machine with a casting and forging mechanism filling a mold cavity with molten metal according to an embodiment of the present invention.

[0025] Figure 4 It is a schematic diagram of closing the liquid inlet of the sealing part of a low-pressure casting machine with a casting and forging mechanism according to an embodiment of the present invention.

[0026] Figure 5 It is a schematic diagram of extruding molten metal in the extrusion part of a low-pressure casting machine with a casting and forging mechanism according to an embodiment of the present invention.

[0027] The figure includes: A, pneumatic feeding device, B, mold, C, sealing extrusion composite device, D: clamping device, E, mold moving device, F, guide column; 1, extrusion piston rod assembly, 2, sealing extrusion composite punch, 3, mold upper mold, 4, mold cavity, 5, mold lower mold, 6, mold gate sleeve, 7, casting slag collection bag, 8, mold exhaust channel, 9, air intake channel, 10, liquid riser, 11, exhaust channel, 12, molten metal, 13, static mold plate, 14, dynamic mold plate. DETAILED DESCRIPTION

[0028] To facilitate understanding by those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings.

[0029] The low-pressure casting machine with a casting and forging mechanism of this embodiment is as follows Figure 1 As shown, it mainly includes a pneumatic feeding device A; a mold B; a sealing and extrusion compound device C; a clamping device D; a mold moving device E; and a guide column F.

[0030] The piston rod of the mold shifting device E is connected to the movable mold plate 14, and the cylinder body of the mold shifting device E is relatively fixed to the static mold plate 13. The mold B includes an upper mold 3 and a lower mold 5, and a cavity is formed between the upper mold 3 and the lower mold 5. The upper mold 3 is connected to the movable mold plate 14, and the lower mold 5 is connected to the static mold plate 13. The clamping device D and the sealing extrusion composite oil cylinder C are installed on the movable mold plate 14. The lower end of the guide column F is fixed to the static mold plate 13 and passes through the center hole of the clamping device D. The pneumatic feeding device A is located below the static mold plate 13 and is connected to the lower mold 5 of the mold B through the liquid riser 10.

[0031] The extrusion compound device C comprises an extrusion piston rod 1 and a sealing extrusion compound punch 2 installed at the end of the extrusion piston rod 1. The top of the sealing extrusion compound punch 2 is a connection part for installation, the middle part is an extrusion part, and the bottom part is a sealing part. The upper die 3 is provided with a through hole, and the sealing extrusion compound punch 2 can reciprocate in the through hole. The lower die 5 is provided with a liquid inlet connected to the liquid riser 10.

[0032] The outer wall of the extrusion part is consistent with the inner wall of the through hole, the outer wall of the sealing part is consistent with the inner wall of the liquid inlet, and the diameter of the sealing part is smaller than the diameter of the extrusion part.

[0033] A slag collecting bag 7 is provided at the outer periphery of the cavity, and an exhaust channel connected to the outside of the mold is provided above the slag collecting bag 7. The exhaust channel remains connected. The connection between the slag collecting bag 7 and the cavity 4 is located at the lower part of the slag collecting bag 7. No less than 3 exhaust channels 8 are provided, and the exhaust channels 8 include corrugated passages.

[0034] The liquid inlet includes a lower mold opening and a mold gate sleeve 6 installed at the lower mold opening.

[0035] Action process (such as Figure 2-5 shown):

[0036] 1. The mold moving device E moves the movable mold plate downward so that the upper mold 3 and the lower mold 5 of the mold B are in contact.

[0037] 2. The clamping device D moves to deform the four guide pillars F to generate sufficient locking force to lock the mold.

[0038] 3. Pressurize the feeding device A through the air inlet channel 9, and the molten metal 12 rises along the riser pipe 10 under the action of pressure.

[0039] 4. The molten metal 12 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 molten metal and is discharged into the atmosphere through the slag collecting bag 7 and the exhaust channel 8.

[0040] 5. After the molten metal fills the mold cavity 4, the air inlet channel 9 stops pressurizing the feeding device A, and the exhaust channel 11 opens to exhaust. At the same time, the sealing extrusion composite device C is activated, and the extrusion piston rod 1 drives the sealing extrusion composite punch 2 to move downward to close the mold gate sleeve 6, so that the mold cavity 4 is isolated from the feeding device A.

[0041] 6. After the mold cavity 4 is isolated from the feeding device A, the sealing extrusion composite punch 2 continues to move downward. Since the mold cavity is already filled with molten metal, the annular area of ​​the sealing extrusion composite punch 2 will produce an extrusion force of 50-100MPa on the molten metal, so that the molten metal in the mold cavity 4 is cooled and solidified under high pressure, thereby increasing the density of the casting and reducing defects such as shrinkage cavities and looseness.

[0042] The upper die 3 is detachably connected to the movable die plate 14, and the sealing extrusion composite punch 2 is detachably connected to the extrusion piston rod 1. By replacing different upper dies, lower dies, sealing extrusion composite punches, etc., casting of different types of castings can be achieved.

[0043] The above embodiments are only for illustrating the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the present invention.

Claims

1. A low-pressure casting machine with a casting and forging mechanism, characterized in that: It includes a pneumatic feeding device, a mold, and a sealing and extrusion compound device; The mold includes an upper mold and a lower mold, and a cavity is formed between the upper mold and the lower mold; The upper mold is provided with a through hole, and the lower mold is provided with a liquid inlet connected to the liquid riser; the air pressure feeding device is connected to the lower mold of the mold through the liquid riser; The sealing extrusion composite device comprises an extrusion piston rod and a sealing extrusion composite punch installed at the end of the extrusion piston rod; The top of the sealing extrusion composite punch is a connecting part for installation, the middle part is an extrusion part, and the lower part is a sealing part; the sealing extrusion composite punch can reciprocate in the through hole; the outer wall of the extrusion part coincides with the inner wall of the through hole, the outer wall of the sealing part coincides with the inner wall of the liquid inlet, and the diameter of the sealing part is smaller than the diameter of the extrusion part.

2. The low-pressure casting machine with a casting and forging mechanism according to claim 1, characterized in that: The upper die is connected to the movable die plate, and the lower die is connected to the static die plate; the air pressure feeding device is located below the static die plate; It also includes a mold locking device and a guide column; the mold locking device is installed on the movable mold plate; the lower end of the guide column is fixed on the static mold plate and passes through the center hole of the mold locking device.

3. The low-pressure casting machine with a casting and forging mechanism according to claim 2, characterized in that: It also includes a mold shifting device; the piston rod of the mold shifting device is connected to the movable mold plate, and the cylinder body of the mold shifting device is relatively fixed to the static mold plate.

4. The low-pressure casting machine with a casting and forging mechanism according to claim 2 or 3, characterized in that: The sealing extrusion composite device comprises a sealing extrusion composite oil cylinder, and the sealing extrusion composite oil cylinder is relatively fixed to the movable template.

5. The low-pressure casting machine with a casting and forging mechanism according to claim 1, characterized in that: The liquid inlet includes a lower mold opening and a mold gate sleeve installed at the lower mold opening.

6. The low-pressure casting machine with a casting and forging mechanism according to claim 1, characterized in that: The upper die and the movable die plate are detachably connected, and the sealing extrusion composite punch and the extrusion piston rod are detachably connected.

7. The low-pressure casting machine with a casting and forging mechanism according to claim 1 or 6, characterized in that: A slag collecting bag is provided on the outer periphery of the cavity, and an exhaust channel connected to the outside of the mold is provided above the slag collecting bag; the exhaust channel remains connected; the connection point between the slag collecting bag and the cavity is located at the lower part of the slag collecting bag, and no less than 3 exhaust channels are provided, including a corrugated passage.

8. A low-pressure casting method with a casting and forging mechanism, characterized in that: The low-pressure casting machine with a casting and forging mechanism according to any one of claims 1 to 7 includes: The upper and lower molds of the mold are molded together; The air pressure feeding device is pressurized through the air inlet channel, and the molten metal rises along the riser under the pressure; it enters the cavity through the liquid inlet of the lower mold, and the air in the cavity moves to the outside of the cavity under the push of the molten metal, and is discharged into the atmosphere through the slag bag and the exhaust channel; When the molten metal fills the cavity, the air inlet channel stops pressurizing the air pressure feeding device, and the exhaust channel of the air pressure feeding device opens to exhaust. At the same time, the sealing and extrusion composite device is activated, and the extrusion piston rod drives the sealing and extrusion composite punch to move downward. The sealing part closes the liquid inlet, so that the cavity is isolated from the air pressure feeding device. The sealing and extruding composite punch continues to move downward, and the extrusion part generates an extrusion force on the molten metal, causing the molten metal to cool and solidify under the extrusion force.

9. The low-pressure casting method with a casting and forging mechanism according to claim 8, characterized in that: The extrusion part will generate an extrusion pressure of 50-100MPa on the molten metal.

10. The low-pressure casting method with a casting and forging mechanism according to claim 8, characterized in that: The upper mold is connected to the movable mold plate, and the lower mold is connected to the static mold plate; the pneumatic feeding device is located below the static mold plate; the clamping device is installed on the movable mold plate; the lower end of the guide column is fixed to the static mold plate and passes through the center hole of the clamping device; the piston rod of the mold shifting device is connected to the movable mold plate, and the cylinder body of the mold shifting device is relatively fixed to the static mold plate; The mold shifting device moves the movable mold plate downward to close the upper mold and the lower mold of the mold; The action of the clamping device causes the guide pin to deform and generate sufficient locking force, thereby locking the mold.

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