What are the characteristics of the control mechanisms for large special vehicles?
2 Answers
Large special vehicle control mechanisms can be categorized into the following three types: (1) Mechanical control mechanism: Mechanical control mechanisms have outstanding advantages such as simple structure, low manufacturing cost, and fewer failures, making them widely used in light and medium-duty trucks and buses. Mechanical control mechanisms can utilize either rod linkage transmission or cable transmission. Cable transmission offers flexible arrangement, but the steel cable has a shorter lifespan and lower tensile stiffness, making it suitable for micro and light vehicles. (2) Hydraulic control mechanism: Hydraulic control mechanisms offer advantages such as low frictional resistance, lightweight, convenient arrangement, and smooth engagement, making them widely used in passenger cars and large buses with long transmission distances. (3) Pneumatic-assisted control mechanism: In heavy-duty vehicles, due to the increased torque transmission requirements, the stiffness of the clutch pressure spring increases. In this case, an engine-driven air compressor can be used as the main power source for the control system, with the driver's manual force serving as auxiliary power, forming a pneumatic-assisted control mechanism.
Let me say a few words about the control mechanisms of large special-purpose vehicles. The first time I got my hands on one, I found the steering wheel really hard to operate—much heavier than that of a regular car, requiring more strength to turn, sometimes to the point of tiring out my arms. The gear shift is also larger and may not be in the most ergonomic position, making it difficult to maintain stable control on bumpy roads. Additionally, these vehicles often come equipped with power-assisted systems to lighten the load, such as hydraulic power steering to make turning easier. Doors and levers are designed to be more robust to prevent damage. When learning to drive these, I had to pay special attention to the large blind spots, and using rearview mirrors along with auxiliary devices like cameras can enhance safety. Overall, operating these vehicles requires more practice to get used to—beginners might make mistakes easily, but once you're experienced, they're quite efficient.
