Casting technique of heavy duty trucks gear box and die

Abstract

The invention relates to a forging process for a heavy truck gearbox and a die, which are used for forging the heavy truck gearbox. The forging process is characterized by adopting low-pressure forging; the forging die consists of an upper die and a lower die, wherein the upper die comprises an upper module, an upper die carrier, core pulling mechanisms, a composite positioning sleeve and a casting ejecting and resetting mechanism; the upper die carrier is connected with a machine tool; the number of the core pulling mechanisms is three; the lower die comprises a lower module, a lower die carrier and a composite positioning pin; a pouring head I (12) and a pouring head II (13) are arranged in the lower module; and the lower die carrier is connected with the machine tool. The forging process and the die do not need expensive investment, and can produce casting products according with requirements; the casting has no riser head, the pouring heads are small, and the utilization rate of the molten metal is high; the arrangement of the double pouring heads effectively shortens the filling stroke of the molten metal, and improves the feeding conditions when the casting is solidified; the casting is solidified under definite pressure to increase the consistency of casting tissues and improve the quality of the casting; and the production efficiency is high, and few auxiliary materials are consumed.

Description

technical field [0001] The invention relates to the technical field of metal casting, in particular to the casting of a heavy-duty truck gearbox. Background technique [0002] Heavy-duty truck gearboxes, also known as flywheel housings, are a key component of heavy-duty truck engines. This component is used in various types of trucks, although the specific structural shape of the component on various types of trucks is different. , but its basic form has great consistency, so this part is a large family; the part is very large, and its dimensions are 950mm×650mm×200mm in length×width×height. High: ① It is necessary to meet the complex structural dimensions and high-precision requirements designed by customers; ② The parts have been inspected by X-ray flaw detection, and the diameter of the internal air holes and shrinkage holes in the uneven thick parts is not more than 2mm, and the number is not more than 5; ③ The parts should be airtight tested under 0.8 bar air pressure,...

AI Technical Summary

Problems solved by technology

Therefore, the casting of this product is very difficult; the traditional method of gear box castings at home and abroad is to use the sand gravity casting process or die casting process for production; when the sand gravity casting process is used for production, there are the following disadvantages: ① casting surface roughness Larger; ②The internal structure of the casting is coarse and the mechanical properties of the casting are poor; ③Due to the complexity of the pouring riser system, the utilization rate of aluminum water is low, which also affects the appearance of the casting; ④The consumption of molding sand is large, and the production The environment is harsh; ⑤The production efficiency is low; and when the die-casting process is used for production, there are the following disadvantages: ①Due to the serious uneven wall thickness of the casting, a large number of pores and shrinkage holes are easily generated in the thick and large parts, which seriously affect the mechanical properties of the product; ② Due to the large size of the parts, more than 5,000 tons of die-casting machines and die-casting molds are required, and the investment is expensive

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