The horn is a car’s audio signal device. During the driving of the car, the driver sends out the necessary acoustic signals according to the needs and regulations to warn pedestrians and draw the attention of other vehicles to ensure the safety of the traffic, and also used to urge and transmit signals.
The electric horn of a car makes sound by the vibration of a metal diaphragm. Automobile electric horn is composed of iron core, magnetic coil, contacts, armature and diaphragm.
Car horns are divided into air horns and electric horns according to sound power; they are divided into three types: cylindrical, spiral, and basin-shaped; according to the sound frequency, they are divided into two types: tweeter and woofer.
Air horn The working principle of the air horn is to use the air flow of compressed air to vibrate the metal diaphragm to make a sound, so it must be used above a car with an air compressor. Generally, buses and heavy goods vehicles are equipped with air horns, especially when long-distance transport vehicles are driving in mountainous areas or curved roads, tweeting with air horns can effectively remind pedestrians and the drivers of the other party to pay attention. Because the volume of the air horn is large, the residual sound is good, the sound is pleasant and spreads far. The air horn generally adopts a cylindrical shape, and uses a tweeter and a bass horn to work together.
Electric horn The working principle of the electric horn is to make a sound by vibrating the metal diaphragm using electromagnetic suction. It is a kind of horn widely used in automobiles. According to the structure, it is divided into three types: cylindrical, spiral and basin-shaped. Generally it is made into spiral or basin-shaped. The commonly used electric horns can be divided into mechanical and electronic according to their working methods. The electronic horn is divided into two types of contact type and non-contact type. The contact type electric horn uses the closing and opening of the contacts to control the on-off of the exciting current in the electromagnetic coil, so that the iron core (or armature) moves up and down at a certain frequency. And the working metal diaphragm vibrates to produce sound. The non-contact electric horn uses electronic circuits to control the on and off of the exciting current in the electromagnetic coil, so that the iron core moves at a certain frequency, and the metal diaphragm is vibrated to generate sound. The electric horn has the advantages of convenient energy, simple structure, small size, small quality, low noise, easy warranty, bright sound and pleasant sound quality. The non-contact electric horn is more durable because it overcomes the shortcomings of the contact type electric horn due to the ablation and oxidation of the horn, which changes the sound of the horn. And its tone and volume are easier to adjust than the contact type, so it is the development direction of car horns.
1. Spiral electric horn The diaphragm continuously vibrates to generate a certain tone of sound waves, and the sound is strengthened by the sounding board and the speaker tube and then emitted. The soundboard is rigidly connected to the diaphragm, which emits sound when it vibrates, strengthens the volume and improves the sound color, making the sound pleasant to the ear. Capacitors are connected in parallel between the contacts. It plays the role of arc extinguishing, protecting the contacts and improving the sound.
2, basin-shaped electric horn Its working principle is the same as the spiral electric horn, and the structure is basically the same, except that there is no loudspeaker, and the sound resonates by the resonance board. In addition, the magnetic circuit uses a solenoid-type electromagnet instead of an E-type core. The solenoid-type is smaller in size and stronger in electromagnetic attraction than the E-type electromagnet.