Patent Application
20180264541
This application is filed based upon and claims priority to Chinese Patent Application No. 201710163272.7, filed on Mar. 19, 2017, the entire contents of which are incorporated herein by reference.
The disclosure relates to the casting field, and specifically to a cooling device for a cast aluminum wheel mold.
At the present stage, about 80% of aluminum alloy wheels are produced by adopting a low-pressure cast molding process. As for a wheel, the junctions of the spokes and the rim are thick and large, belong to obvious casting hot spots, and are the difficulty in present production. A large number of production practices show that common defects occurred at the hot spots are loosening and shrinkage, because heat is too concentrated therein, causing slow solidification of molten aluminum, whereas at the spoke part having a thin wall, the molten aluminum is quickly crystallized and easily early solidified to block a molten aluminum flow channel, thereby hindering effective feeding on the thick and large hot spots and finally leading to molding defects.
Moreover, relatively low degree of supercooling may result in thick and large internal grains and shrunk and loose tissues at the outer rim of the wheel, so that the mechanical properties of the wheel are directly influenced, a failure phenomenon appears in reliability tests, and the safety performance of the wheel is influenced.
A side mold cooling device for a wheel mold is provided, which may capable of, among other things, overcoming the defects of loosening and shrinkage easily occurring at thick and large hot spots and improving the molding quality of a wheel.
In one embodiment of the disclosure, an improved cooling device for a side mold of a cast wheel mold includes an air pipe system and red copper. Air holes are provided at the positions in the back cavity of a side mold corresponding to spokes, and the red copper is casted in the air holes. A groove body corresponding to a window is provided in the back cavity of the side mold, and the groove body is made according to the shape of a rim.
The air pipe cooling system includes an air pipe connector, a main air pipe, air claws and air outlets. The main air pipe is annular and concentric with the outer diameter of a wheel, and two ends of the main air pipe are sealed by plug welding. The air pipe connector is welded on the outer side of the main air pipe, and the air pipe connector is connected with a compressed air storage device; the air claws are welded on the inner side of the main air pipe, correspond to hot spots of the wheel and are as many as the air holes. The air outlets are distributed uniformly at a position corresponding to the window on the main air pipe, and the air direction is ensured to be perpendicular to the molded surface of the groove body.
The roots of the air holes are spaced 8-10 mm from a cavity surface to ensure the strength of the mold. The quantity of the air holes is 1 to 3.
The thickness of the red copper casted in the air holes is 5-8 mm. The root of the groove body is spaced 8-10 mm from the cavity surface.
The air pipe system is fixed in the back cavity of the side mold by welding or bolt connection, and shall be installed firmly. When cooling starts, compressed air enters the main air pipe via the connector, and a part of the compressed air is directly blown to the hot spots of the spokes along the air claws and quickly takes the heat of the mold away via the red copper, thus ensuring quick cooling of the hot spots; the other part of the compressed air is directly blown to the rim of the window via the air outlets, so that the degree of supercooling is improved, grains are thinned, and excellent mechanical properties of the rim are ensured; and in a pressure casting cycle, the cooling generally starts from 30-50 seconds after liquid is heated and ends till the liquid is completely solidified at the hot spots, and this process is circulated, thus ensuring stable and continuous production of wheel castings.
The disclosure ensures effective cooling of hot spots, gives consideration to crystal forming at the outer rim, strengthens the heat dissipation capability of the mold, quickly takes concentrated heat, improves the solidification speed of molten aluminum, eliminates loosening and shrinkage of hot spots, simultaneously improves the degree of supercooling, thins grain structures, improves the mechanical properties of the outer rim of the wheel, obviously shortens the casting production cycle, improves the production efficiency and reduces the production cost.
In the figure, 1-bottom mold, 2-top mold, 3-side mold, 31-air hole, 32-groove body, 4-air pipe system, 41-air pipe connector, 42-main air pipe, 43-air claw, 44-air outlet, 5-red copper.
Air holes 31 are provided at the positions in the back cavity of a side mold 3 corresponding to spokes, and the roots of the air holes 31 are spaced 8-10 mm from a cavity surface to ensure the strength of the mold; the quantity of the air holes 31 is 1 to 3; red copper 5 is casted with a thickness of 5-8 mm in the air holes 31 to accelerate heat dissipation of the mold. A groove body 32 corresponding to a window is provided in the back cavity of the side mold 3, the groove body 32 is designed according to the shape of the window, and the root of the groove body 32 is spaced 8-10 mm from the cavity surface.
An air pipe cooling system 4 includes an air pipe connector 41, a main air pipe 42, air claws 43 and air outlets 44; the main air pipe 42 is annular and concentric with the outer diameter of a wheel, and two ends of the main air pipe 42 are sealed by plug welding. The air pipe connector 41 is welded on the outer side of the main air pipe 42, and the air pipe connector 41 is connected with a compressed air storage device; the air claws 43 are welded on the inner side of the main air pipe 42, correspond to hot spots of the spokes and are as many as the air holes 31 in the back cavity of the side mold.
The ends of the air claws 43 are spaced 5 mm from the end face of the red copper 5; the position on the main air pipe 42 corresponding to the groove body 32 is provided with the air outlets 44, diameters of which are 2-4 mm and intervals of which are 20-30 mm, and the air direction is ensured to be perpendicular to the molded surface of the cavity, thus cooling the rim.
The air pipe system 4 is fixed in the back cavity of the side mold 3 by welding or bolt connection, and shall be installed firmly. When cooling starts, compressed air enters the main air pipe via the connector, and a part of the compressed air is directly blown to the hot spots of the spokes along the air claws and quickly takes the heat of the mold away via the red copper, thus ensuring quick cooling of the hot spots; the other part of the compressed air is directly blown to the rim of the window via the air outlets, so that the degree of supercooling is improved, internal grains are thinned, and excellent mechanical properties of the rim are ensured; and in a pressure casting cycle, the cooling generally starts from 30-50 seconds after liquid is heated and ends till the liquid is completely solidified at the hot spots, and this process is circulated, thus ensuring stable and continuous production of wheel castings.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201710163272.7 | Mar 2017 | CN | national |
