What are the characteristics of the control mechanisms for large special vehicles?
4 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.
From my experience, the control mechanisms of large special-purpose vehicles are quite unique. The steering wheel is usually oversized and heavy, making it difficult to operate without a power assist system, but fortunately most modern models are equipped with hydraulic power steering to reduce the effort required. The gear shifting mechanism is a bit more complex, possibly featuring part-time four-wheel drive, requiring more careful speed control during operation. Driving such vehicles in harsh environments results in slower control responses; for example, on muddy terrain or steep slopes, you need to adjust the direction slowly to avoid losing control. I recommend regularly checking the lubrication of these components to prevent stiffness. Another characteristic is the different positioning of control levers, designed to facilitate specific tasks like mechanical lifting. Overall, they are more challenging to operate than family cars but are designed for reliability and durability.
I have driven large special vehicles, and their control mechanisms have several key features. They are designed to be more robust, suitable for heavy-duty work, with a heavier steering wheel that often uses power assistance systems. The gear shifting mechanism includes automatic or manual transmissions to handle multiple loads. During operation, auxiliary devices such as pneumatic assistance are crucial. From a safety perspective, limited visibility requires the help of auxiliary equipment.
