In the design of car rearview mirror die-casting mold, how to consider the exhaust problem of the mold?
Publish Time: 2024-12-10
In the design field of car rearview mirror die-casting mold, the exhaust problem of the mold is like a director who is hidden behind the scenes but plays a key role in the performance effect, which is directly related to the quality and performance of the product.
First of all, the parting surface is an important position for exhaust design. Reasonable planning of the parting surface position can make the cavity naturally form an exhaust channel when the mold is closed. For example, for some car rearview mirror molds with simple shapes, the parting surface can be set at the maximum cross-section of the product contour, and the gap of the parting surface can be used to allow the air to be discharged smoothly during the die casting process. However, it is necessary to pay attention to controlling the gap of the parting surface. If it is too large, the molten metal will overflow and form flash, and if it is too small, the exhaust will be poor.
The design of the exhaust groove is even more delicate and critical. The exhaust groove should be distributed in the part where the molten metal is last filled, such as the end of the cavity away from the gate, the matching gap between the core and the cavity, etc. Its depth and width need to be precisely controlled. Generally speaking, the depth is between 0.05 and 0.15 mm, and the width depends on the size of the mold and the exhaust requirements. Taking the aluminum alloy die-casting automobile rearview mirror mold as an example, if the exhaust groove is too shallow, the air in the cavity is difficult to be discharged quickly, which will cause internal pores in the casting and affect the strength and surface quality of the rearview mirror; if the depth is too large, the molten metal will easily enter the exhaust groove to form a flash.
The application of special materials such as breathable steel provides innovative ideas for exhaust. In local areas where the mold is prone to holding air, such as deep cavities and complex structures, breathable steel inserts are used. There are many tiny pores inside the breathable steel, and air can pass freely, while the molten metal cannot penetrate due to surface tension. This is like opening a secret passage on a blocked traffic artery, ensuring that the gas is discharged smoothly while ensuring the normal progress of the die-casting process.
In addition, the natural gaps in the ejector hole, slider gap and other parts of the mold can also be cleverly used for exhaust. When designing the ejector layout, in addition to considering the function of ejecting the product, its auxiliary role in exhaust should also be taken into account. For example, the ejector is set around the area where cavitation may occur, and the air is exhausted by the gap between the ejector and the hole.
In short, in the design of car rearview mirror die-casting mold, the exhaust problem must be considered throughout. From the parting surface to the exhaust groove, from the use of special materials to the use of various gaps, a multi-pronged approach can ensure that the mold is exhausted smoothly during the die-casting process, and produce a pore-free, high-quality car rearview mirror casting, providing a clear and reliable rear view guarantee for the safe driving of the car.
