LOCAL EXTRUSION DEVICE FOR HIGH-PRESSURE CASTING

Abstract

The disclosure provides a local extrusion device for high-pressing casting. The local extrusion device for high-pressure casting includes an extrusion core sleeve, an extrusion rod, an extrusion oil cylinder and an extrusion oil cylinder piston. The extrusion oil cylinder includes the extrusion oil cylinder piston, the extrusion oil cylinder piston is connected with the extrusion rod, the extrusion rod is positioned in the extrusion core sleeve, and the extrusion core sleeve and the extrusion oil cylinder are fixed.

Claims

1. A local extrusion device for high-pressure casting, comprising an extrusion core sleeve, an extrusion rod, an extrusion oil cylinder and an extrusion oil cylinder piston, characterized in that, the extrusion oil cylinder comprises the extrusion oil cylinder piston, the extrusion oil cylinder piston is connected with the extrusion rod, the extrusion rod is positioned in the extrusion core sleeve, and the extrusion core sleeve and the extrusion oil cylinder are fixed.

2. The local extrusion device for high-pressure casting according to claim 1, wherein the extrusion core sleeve comprises a cavity in a direction facing a casting.

3. The local extrusion device for high-pressure casting according to claim 1, wherein the ratio of the cross sectional area of the extrusion oil cylinder piston to the cross sectional area of the extrusion rod is greater than 10.

4. The local extrusion device for high-pressure casting according to claim 1, wherein the ratio of the cross sectional area of the extrusion oil cylinder piston to the cross sectional area of the extrusion rod is 10-40.

5. The local extrusion device for high-pressure casting according to claim 1, wherein the ratio of the cross sectional area of the extrusion oil cylinder piston to the cross sectional area of the extrusion rod is 12.

6. The local extrusion device for high-pressure casting according to claim 1, wherein a front end of the extrusion rod is higher than an end surface of the extrusion sleeve by 4-10 mm when the extrusion oil cylinder piston is not extruded.

7. The local extrusion device for high-pressure casting according to claim 1, wherein a gap between a lower cavity inner wall of the extrusion core sleeve and the outline of the extrusion rod is 4-10 mm.

8. The local extrusion device for high-pressure casting according to claim 1, wherein the ratio of the cross sectional area of the extrusion oil cylinder piston to the cross sectional area of the extrusion rod is 12; when the extrusion oil cylinder piston is not extruded, the front end of the extrusion rod is higher than the end surface of the extrusion sleeve by 10 mm; and the gap between the lower cavity inner wall of the extrusion core sleeve and the outline of the extrusion rod is 4 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The embodiment of the disclosure will be described in detail below with reference to the drawings, wherein:

[0021] FIG. 1 is a structural schematic view of a local extrusion device for high-pressure casting before extrusion;

[0022] FIG. 2 is a structural schematic view of a local extrusion device for high-pressure casting after extrusion;

[0023] before extrusion; right figure: after extrusion); and

LIST OF REFERENCE SYMBOLS

[0024] 01 casting [0025] 02 extrusion boss [0026] 03 extrusion core sleeve [0027] 04 extrusion rod [0028] 05 extrusion oil cylinder [0029] 06 extrusion oil cylinder piston [0030] 07 surface of casting [0031] 08 front end of extrusion rod [0032] 10 end surface of extrusion sleeve [0033] 11 lower cavity inner wall of extrusion core sleeve [0034] 12 cavity

DETAILED DESCRIPTION

[0035] Test Group 1

[0036] A local extrusion structure for aluminum alloy high-pressure casting includes an extrusion boss (02), an extrusion core sleeve (03), an extrusion rod (04), an extrusion oil cylinder (05) and an extrusion oil cylinder piston (06). The ratio of the cross sectional area of the extrusion oil cylinder piston (06) to the cross sectional area of the extrusion rod (04) is 12 to guarantee a big enough extrusion force. When the oil cylinder piston is not extruded (located at a zero position), a front end (08) of the extrusion rod is higher than an end surface (10) of the extrusion sleeve by 10 mm, and meanwhile, a cavity (12) is formed between the front end (08) of the extrusion rod and the lower cavity inner wall (11) of the extrusion core sleeve; in an extrusion process of the extrusion rod, a gap between the lower cavity inner wall (11) of the extrusion core sleeve and the outline of the extrusion rod (04) is 10 mm (which is also the range of the wall thickness of the extrusion boss (02)). In order to guarantee good extrusion effect of the local extrusion technology, local extrusion starting time and local extrusion delay time on a die-casting machine are adjusted, the extrusion stroke of the extrusion rod is enabled to reach 15 mm, the distance from the front end (08) of the extrusion rod to the surface (07) of a casting is 2 mm after extrusion, an X-ray flaw detection machine detects a thick and large part of the casting (01), and the result shows that the defect of shrinkage porosity does not exist. In the local extrusion technology, the extrusion starting time (timing is started at a two-speed transformation point) is 3 s, the extrusion delay time is 3 s, in a spraying cycle, the returned local extrusion core is required to be pushed out again for spraying to cool and lubricate the extrusion core well, jamming in the extrusion process is prevented, and the service life of the local extrusion core is prolonged.

[0037] Test Group 2

[0038] A local extrusion structure for aluminum alloy high-pressure casting includes an extrusion boss (02), an extrusion core sleeve (03), an extrusion rod (04), an extrusion oil cylinder (05) and an extrusion oil cylinder piston (06). The ratio of the cross sectional area of the extrusion oil cylinder piston (06) to the cross sectional area of the extrusion rod (04) is 12 to guarantee a big enough extrusion force. When the oil cylinder piston is not extruded (located at a zero position), a front end (08) of the extrusion rod is higher than an end surface (10) of the extrusion sleeve by 4 mm, and meanwhile, a cavity (12) is formed between the front end (08) of the extrusion rod and the lower cavity inner wall (11) of the extrusion core sleeve; and in an extrusion process of the extrusion rod, a gap between the lower cavity inner wall (11) of the extrusion core sleeve and the outline of the extrusion rod (04) is 4 mm (which is also the range of the wall thickness of the extrusion boss (02)). In order to guarantee good extrusion effect of the local extrusion technology, local extrusion starting time and local extrusion delay time on a die-casting machine are adjusted, the extrusion stroke of the extrusion rod is enabled to reach 10 mm, the distance from the front end (08) of the extrusion rod to the surface (07) of a casting is 3 mm after extrusion, an X-ray flaw detection machine detects a thick and large part of the casting (01), and the result shows that the defect of shrinkage porosity does not exist. In the local extrusion technology, the extrusion starting time (timing is started at a two-speed transformation point) is 0.5 s, the extrusion delay time is 8 s, in a spraying cycle, the returned local extrusion core is required to be pushed out again for spraying to cool and lubricate the extrusion core well, jamming in the extrusion process is prevented, and the service life of the local extrusion core is prolonged.

[0039] Test Group 3

[0040] A local extrusion structure for aluminum alloy high-pressure casting includes an extrusion boss (02), an extrusion core sleeve (03), an extrusion rod (04), an extrusion oil cylinder (05) and an extrusion oil cylinder piston (06). The ratio of the cross sectional area of the extrusion oil cylinder piston (06) to the cross sectional area of the extrusion rod (04) is 12 to guarantee a big enough extrusion force. When the oil cylinder piston is not extruded (located at a zero position), a front end (08) of the extrusion rod is higher than an end surface (10) of the extrusion sleeve by 10 mm, and meanwhile, a cavity (12) is formed between the front end (08) of the extrusion rod and the lower cavity inner wall (11) of the extrusion core sleeve; and in an extrusion process of the extrusion rod, a gap between the lower cavity inner wall (11) of the extrusion core sleeve and the outline of the extrusion rod (04) is 4 mm (which is also the range of the wall thickness of the extrusion boss (02)). In order to guarantee good extrusion effect of the local extrusion technology, local extrusion starting time and local extrusion delay time on a die-casting machine are adjusted, the extrusion stroke of the extrusion rod is enabled to reach 10 mm, the distance from the front end (08) of the extrusion rod to the surface (07) of a casting is 5 mm after extrusion, an X-ray flaw detection machine detects a thick and large part of the casting (01), and the result shows that the defect of shrinkage porosity does not exist. In the local extrusion technology, the extrusion starting time (timing is started at a two-speed transformation point) is 2 s, the extrusion delay time is 10 s, in a spraying cycle, the returned local extrusion core is required to be pushed out again for spraying to cool and lubricate the extrusion core well, jamming in the extrusion process is prevented, and the service life of the local extrusion core is prolonged.

[0041] Test Result

[0042] Specific tests are carried out in a research and development workshop of Engineering Technology Institute of CITIC Dicastal Co., Ltd. according to the above arrangement. The test result shows that the occurrence rate of casting wastes caused by the defect of shrinkage porosity at the thick and large position of the product in the test group 1, the test group 2 and the test group 3 are reduced by 70.24%, 76.20% and 87.15% respectively.

[0043] Thus, by the local extrusion devices in the different test groups, the number of casting wastes caused by the defect of shrinkage porosity at the thick and large position of the product is reduced. Moreover, by the extrusion device in the test group 3, the defect of shrinkage porosity at the thick and large position of the product is greatly reduced unexpectedly, and therefore, the production cost is remarkably reduced.

[0044] The embodiments described above are for illustrative technical concept and features of the disclosure, the purpose is to allow those skilled in the art to understand the contents of the disclosure and implement, and not to limit the scope of the disclosure. Where under the equivalent changes or modifications made in the spirit of the disclosure shall fall within the scope of the disclosure.