Car driver’s doubts: why the truck horn is so loud

In daily driving, the driver of the car will ask me an idiot question from time to time: the same is the horn, why is the horn of your big truck so loud?

At this time, I will smile a little: Because I am big! Long! So the power is even stronger! Our large trucks are basically air horns, and the structure is different from ordinary car horns. The sound is naturally unusual!

Air Horn Principle
The air horn is generally composed of four parts: air source, control switch, sounder and sound amplifier. The air source is the source of compressed gas, which can be a DC electric air pump or the air source of the vehicle itself. The control switch is generally an electromagnetic switch, which is connected to the horn button in the cab.

Inside the sound generator is a sound-producing membrane made of paper, silica gel, metal, etc., and the flute sound is generated by the high-frequency vibration of the membrane. The sound amplifier is a thin and thick structure, which can make the sound louder and spread farther.

The air horn uses the air flow of compressed air to vibrate the metal diaphragm (or paper film, silicone diaphragm), and then expands the sound through the loudspeaker port, which generates a high-alarm warning effect.

Compared with the electric horn, the sound produced by the air horn is louder and better, can transmit a long distance, and can give a warning effect to vehicles in the distance.

Classification of air horn
At present, there are two common types of air horns: electric air horns and electric air horns. The electric air horn generates compressed air through a DC motor air pump, and then introduces the compressed air into the air horn through an air pipe, thereby emitting a whistle sound. This horn can be used on motorcycles and small cars.

The electric control air horn is composed of two to four or more horn tubes. The air pump (brake air pump or electric air pump) provided by the car provides air pressure. The car horn switch communicates with the electric control switch. Flute. This electronically controlled air horn is currently the most commonly used on large and medium trucks.

Most of the air horns we see are long horns (tubular). According to the tube length of the horn, it is divided into different audio levels. The longer the tube length, the lower the sound, and the shorter the tube length, the higher the sound.

There are also some vehicles where the air horn is spiral, such as the snail air horn used on Dongfeng Tianjin and Volvo trucks. The shape and sound of the snail air horn are obviously different from those of the long horn. This is that radish and green vegetables have their own love.

In foreign countries, air horns are also a kind of truck culture. Many people will modify air horns with unique tones or individual appearances to make their car unique.

Too loud is not necessarily a good thing

The air horn was born to make the alarm louder, but too loud is not entirely good. For example, in urban areas and around schools and hospitals, huge horn sounds can seriously disturb people. Therefore, the use of air horns is strictly prohibited in many urban areas.

All many trucks use a dual-horn configuration, with electric and air horns at the same time, and a switch button on the dashboard. In urban areas, use electric horns with soft sounds, and switch to loud air horns on open roads.

Remind my friends, for the sake of everyone around us, we still have to use the speaker reasonably ~ After all, our big speaker is too powerful!