The car bumper is a safety device that absorbs the external impact and protects the front and rear of the body. 20 years ago, the front and rear bumpers of the car were mainly made of metal materials, and were punched into U-shaped channel steel with a thickness of 3 mm or more. The surface was treated with chrome plating and riveted or welded with the frame rails. The big gap seems to be an attached part.
With the development of the automotive industry, car bumpers have also entered the path of innovation as an important safety device. In addition to maintaining the original protection function, the front and rear bumpers of today's cars must pursue harmony and unity with the shape of the car body, and pursue their own lightweight. In order to achieve this goal, the front and rear bumpers of the car currently use plastic, which is called plastic bumper.
The plastic bumper is composed of three parts: outer plate, cushioning material and beam. The outer plate and the cushioning material are made of plastic, and the beam is stamped into a U-shaped groove by a cold-rolled sheet having a thickness of about 1.5 mm; the outer plate and the cushioning material are attached to the beam, and the beam is screwed to the frame longitudinal beam. Can be removed at any time. Plastics used in such plastic bumpers are generally made of two types, polyester and polypropylene, and are injection molded. For example, the bumper of the Peugeot 405 sedan is made of a polyester-based material and is formed by a reaction injection molding method. The bumpers of Volkswagen's Audi 100, Golf, Santana in Shanghai, and Xiali in Tianjin are made of polypropylene-based materials by injection molding. There is also a kind of plastic called polycarbonate in foreign countries. It is infiltrated into the alloy composition and is alloy injection molding. The processed bumper not only has high strength rigidity, but also has the advantage of being weldable, and the coating performance is good. The use of cars is increasing.
The plastic bumper has strength, rigidity and decoration. From the safety point of view, when the car collides, it can play a buffering role to protect the front and rear body. From the appearance, it can be naturally combined with the car body. One body, with good decoration, has become an important part of the decorative car shape.
In addition, in order to reduce the damage to the occupant when the car is in a side collision accident, a door bumper is usually installed on the car to enhance the anti-collision impact of the door. This method is practical and simple, and has little change to the structure of the vehicle body. It has been widely used. As early as the '93 Shenzhen International Automobile Exhibition, the Honda Accord exhibited a part of the door to expose the door bumper to the audience to show its good safety performance.
Installing the door bumper is to erect or tilt several high-strength steel beams in the door panel of each door to play the role of the front bumper of the front and rear of the car. Forming a "copper wall iron wall" that gives the car occupant a maximum safe area. Of course, installing such a door bumper will undoubtedly increase the cost for the car manufacturer, but for the occupants of the car, the safety and security will increase a lot.