An exhaust structure in the die-casting mold of the front bearing cover of the ultra-low-speed die-cast camshaft

Abstract

The invention discloses an inner venting structure of a pressure casting die of a front bearing cap of an ultra-low speed pressure casting cam shaft. The pressure casting die is provided with an air trapping area, wherein the inner surface of the air trapping area is provided with a 8-shaped insert; the top of the 8-shaped insert is connected with a die top block; an air overflowing gap is formed between the bottom of the 8-shaped insert and the surface of an adjacent die and is communicated with an outer exhaust passage of the die. According to the inner venting structure of the pressure casting die of the front bearing cap of the ultra-low speed pressure casting cam shaft, the practical flow direction of molten aluminum in a die cavity and influence on a product by temperature change and air discharge during production are considered, the structural design of the die is improved, a pit mold cavity part is subjected to local transformation, a trap phenomenon in low-speed pressure casting is thoroughly eliminated, the local quality of the product is improved, and a rejection rate is lowered.

Description

technical field [0001] The invention relates to an exhaust structure of an ultra-low-speed die-casting mold, in particular to an exhaust structure in an ultra-low-speed die-cast camshaft front bearing cover in a die-casting mold. Background technique [0002] Shrinkage cavities and porosity of ultra-thick aluminum alloy die-casting parts have always been a difficult problem in the industry. The low-speed die-casting method reduces the turbulent flow in the die-casting process, reduces the probability of the aluminum alloy melt wrapping gas, prolongs the exhaust time and the cooling process in the flow, and can solve the shrinkage problem of ultra-thick die-casting parts, but Because the flow rate of molten aluminum in low-speed die-casting is lower than that in high-speed die-casting, the impact of molten aluminum on the surface of the cavity during the flow is too gentle, so some gas will accumulate in the dead corners, mainly in the deep pits formed as a whole, so the surf...

AI Technical Summary

Problems solved by technology

The existing technologies mainly include the following two types: 1. Set up exhaust grooves on the parting surface. However, due to the large thickness of most products, when the die-casting process adopts ultra-low speed, the gas in the complex cavity cannot be well removed. , resulting in more appearance and internal defects and low pass rate when the product is cast

2. Ordinary insert exhaust, such an exhaust structure has a single shape, which cannot be fitted with the exhaust position that requires a specific position, so as to well exclude the gas at a specific point, resulting in air barrier defects

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