Experts interpret “Explanation of the Inspection of the Zunjie V800 Brake Pedal”: “Gradually increasing force” differs from “instantaneous force”

On October 13, a reporter from the Beijing News Shell Finance learned from JAC Motors that the “Explanation of the Inspection of the Zunjie V800 Brake Pedal” states that the Zunjie V800 brake pedal can withstand a force of 1,500 N, meeting industry standards. In a more stringent test, it was subjected to a longitudinal force of 3,000 N, with no cracks or damage observed. Two experts offered their interpretations and analysis.

The explanation states that the Zunjie V800 was tested by “gradually increasing the longitudinal force to 3,000 N at a loading speed of 20 mm/min, holding it for 5 seconds before releasing the force. This was repeated five times across 14 brake-pedal assemblies, none of which showed cracks or damage on visual inspection.”

Meng Wei, deputy chief engineer for complete-vehicle products at an automaker, told a reporter from the Beijing News Shell Finance: “National standards do not require force to be applied at an extremely high speed. Slowly increasing the force to 2,000 N over one or two seconds is a different test from applying 2,000 N with a sudden ‘slam’ in a fraction of a second when someone faces an emergency. The brake pedal has to withstand different pressures in these two situations, and the people designing its support bracket need to take that into account.”

An Xin, a product structural design engineer, added another perspective to the Beijing News Shell Finance reporter: “The force on a brake pedal differs depending on whether the vehicle is stationary or moving. Zunjie did not specify whether this test was static or dynamic. The speed at which the force is applied—fast or slow—is also very important.”