What is the beam under the car door called?
4 Answers
The plastic guard plate under the car door is called a side skirt. It is also referred to as a lower side beam or lower skirt. Here are the specific details: 1. Highly prone to damage: Due to its plastic material, this part is susceptible to scratches and collisions, making it extremely easy to damage. 2. Function: The side skirt functions similarly to an air dam, reducing the airflow entering the underside of the car from both sides. It has a certain spoiler effect and can significantly reduce air resistance under certain conditions. Here are some additional details: Common door accessories: 1. Door glass: Provides the driver with a certain degree of side visibility to assist in driving. 2. Door hinge: Used to support the door, ensuring smooth opening and closing. 3. Door inner handle: Generally fixed on the door trim panel, while the outer handle is fixed on the door outer panel, facilitating the closing and opening of the door. 4. Door stopper: Used to limit the maximum opening angle of the door, ensuring it stops at a certain angle for easy entry and exit of passengers.
I've been driving for almost thirty years, and that part under the door has always been called the rocker panel. It's one of the fundamental structural components of a car's body, directly connecting the front and rear wheel areas, acting like a sturdy backbone supporting the entire vehicle. The rocker panel is crucial because it absorbs impact during side collisions to protect passengers and prevents body twisting or deformation. However, precisely because of its low position and constant exposure, it easily accumulates dirt from mud splashes during rainy days, and winter road salt or de-icing agents can accelerate rusting. I remember the year I bought my car—I neglected maintenance, and the rocker panel rusted through with holes, costing me thousands in repairs. Now I've developed a habit of inspecting it monthly, cleaning it thoroughly with a pressure washer, and applying rust inhibitor every season. While driving, I also avoid parking on steep slopes to prevent undercarriage scraping, since damage to this small part can reduce the vehicle's overall rigidity. I recommend all car owners perform regular maintenance to prolong their car's lifespan.
As a girl who loves taking care of my car, I remember the beam under the door is called the sill beam. It guards the bottom like the 'waist' of the car body. Although this area is inconspicuous, it plays a significant role—mud, water, sand, and stones often splash onto it during daily driving, accumulating and causing rust or corrosion, especially if not cleaned promptly after rain. It's also crucial for safety; if the side is impacted, the sill beam can absorb the shock and protect the frame from collapsing. I only learned to pay attention to it after buying my car, regularly using a sponge to clean off stains and applying a waterproof coating. When parking on slopes, I'm careful not to scratch it, as repairs can be troublesome and affect the car's appearance. I advise new car owners not to overlook this corner when washing their cars—it can prevent major issues.
Having worked in auto repair shops for many years, we refer to the beam under the door as the rocker panel or sill, which is the supporting beam on the side of the vehicle body. Its primary functions are to reinforce the frame structure and withstand side impacts. Often exposed to harsh environments, it is prone to rust or deformation, leading to body sealing issues. Common repairs include rust removal, repainting, or replacing damaged sections. It is recommended to avoid scraping and conduct regular inspections.
