The manufacturing process of automotive wheel hub units covers multiple methods, mainly including forging, casting, and spinning. Different processes have their own characteristics in strength, weight, cost, and applicable scenarios, as follows:
1. Forging process
Principle and process
The heated metal block (such as aluminum ingot) is placed in a high-pressure mold and directly extruded into a wheel hub blank through a thousand ton pressure machine. Subsequently, spinning processing is carried out to further optimize the shape and performance, and finally CNC machining is used to ensure dimensional accuracy.
Features
Advantages: Metal molecules are tightly arranged, with a strength that is more than 30% higher than that of cast wheels, and the weight can be reduced by about 50%;
; Thin walls and flexible design, supporting multi piece structures (such as two-piece and three piece) to meet personalized needs.Limitations: High equipment cost, low yield rate, expensive manufacturing cost, mostly used in high-performance racing cars, luxury cars, or modification markets.
.Typical Applications
Racing Wheel Hub: Pursuing ultimate lightweight and strength to enhance acceleration and handling performance.
.Luxury cars: Through forging technology, unique shapes are achieved, highlighting the brand's high-end positioning.
.II. Casting Process
Principle and Process
Molten metal (such as aluminum alloy) is injected into a mold and formed by different pressure methods.
. Mainly divided into:Gravity casting: Metal liquid naturally fills the mold by gravity, with low cost but uneven metal distribution and average strength, suitable for ordinary car models. Low pressure casting: Using low pressure to evenly fill the mold with molten metal, it has high density and strength, and can manufacture complex shapes. It is the mainstream process for aluminum alloy wheels.
High pressure casting: using high pressure to quickly press into the mold, with high efficiency but a single shape and rough surface, often used for mass production.
.Features
Advantages: Mature technology, low cost, and ability to adapt to large-scale production;
; Low pressure casting can balance strength and modeling complexity.Limitations: Gravity casting is prone to producing porosity, which requires subsequent airtightness testing and repair;
; High pressure casting wheels have a large weight and poor heat dissipation.Typical Applications
Ordinary passenger cars: Low pressure cast wheels meet daily usage needs and have controllable costs.
. Commercial vehicles: Gravity cast wheels are used in scenarios where performance requirements are not high, such as spare tire wheels for trucks.III. Spinning Process
Principle and Process
Combining the characteristics of casting and forging, it can be divided into two types:
Casting spinning: secondary processing of the cast wheel hub, using rotary stamping to make the material distribution more uniform, improve strength and reduce weight.
.Forging spinning: Spinning is performed on the basis of forging blanks to further optimize performance, commonly used in high-end wheel hub production.
.Features
Advantages: Achieving lightweight while ensuring strength, high material utilization rate;
; Can repair casting defects and improve the overall performance of the wheel hub.Limitations: The process is complex, requires specialized equipment, and the cost is higher than ordinary casting.
.Typical applications
Sports vehicles: achieve a balance between lightweight and high-strength through spinning technology, and improve handling.
.New energy vehicles: Reduce wheel hub weight to extend range while meeting structural strength requirements.
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