Take reasonable measures to improve the wheel surface defects arise, in order to avoid or reduce the production of these defects on the premise that we have to analyze the causes of surface defects of the wheel,so as to arrive practice is as follows:

1）to improve the hub hole

When the wheel is cast with a funnel pouring, the general height of the alloy in the funnel is basically the same, so the casting speed of the alloy depends mainly on the size of the funnel outlet. In order to reduce the filling speed, the funnel was improved, reducing the funnel outlet diameter, so that the funnel outlet diameter from the original φ36 to φ28. At the same time in order to strengthen the slag, gas filtration and reduce the degree of turbulence, the funnel under the funnel filter from the original single layer to double.

In addition, in order to strengthen the exhaust of the hub in the wheel, the exhaust system of the core is improved to increase the number of the core exhaust groove and shorten the exhaust groove spacing, thereby enhancing the exhaust effect.

2） the improvement of the hub surface shrinkage measures

In order to strengthen the cooling of the hub core, in the lower core with water cooling channel. At the same time in the lower core is also set on the exhaust plug, the original water-cooled channel hole and the exhaust hole is very close, wall thickness of only 3 ~ 5mm, making the thin wall quickly crack, in order not to affect the exhaust, And the gap between the iron pipe and the mold affects the heat transfer performance of the mold to the cooling medium, reduces the cooling capacity of the water cooling pipe, resulting in the high temperature of the mold core, the mold temperature field is not conducive to the formation of sequential solidification, The hub surface is prone to shrinkage defects. So the lower core of the exhaust hole and cooling holes were re-arranged to ensure that the wall between the two holes of not less than 10mm, the abolition of the cooling hole in the steel pipe, enhanced cooling capacity, so that the core temperature reached a reasonable temperature.

3） Improved spokes

Rotor bar at the mold of aluminum foil produced by blocking the exhaust line, seriously affecting the mold exhaust effect. In order to strengthen the exhaust in the spoke area, the mold exhaust line of the spoke is re-cut to remove the aluminum dust that clogs the exhaust line and the exhaust system is regularly inspected and cleaned to ensure the exhaust flow at the spoke.

Through the actual production verification, the above exploration and improvement is correct and effective. After the improvement of the wheel of the stomata, the hub shrinkage and the bar less cast defects greatly reduced, the product reject rate dropped to about 4%, and the quality is relatively stable.