In modern cars and buses, integrated headlight lighting devices - block headlights - are widely used. Read about what a headlight unit is, how it differs from a conventional headlight, what types it is, how it works, as well as the choice of these devices - read in this article.
What is a headlight?
A headlamp unit is an electric lighting device containing headlamps and some (or all) of the signal lights to be located at the front of the vehicle. The headlight unit is a single design, it is easy to install and dismantle, saves space and provides an attractive appearance of the car.
The headlight unit can combine various components of automotive lighting:
• Dipped headlights;
• High beam headlights;
• Direction indicators;
• Front parking lights;
• Daytime running lights (DRL).
The most common headlights with low and high beam, direction indicator and side light, DRL is more convenient to install below the level of the headlights, in this case they fully comply with the requirements of GOST. Fog lights are not integrated into the headlight unit, since their installation on the car is not required.
Types and characteristics of headlights
Headlights can be divided into groups according to the principle of light beam formation used in head optics, the configuration and number of lighting fixtures, the type of installed light sources (lamps) and some design features.
According to the number of lighting fixtures, the headlights are divided into several types:
• Standard - the headlight includes head optics, a direction indicator and a front parking light;
• Extended - in addition to the above lighting equipment, DRLs are included in the headlight.
At the same time, block headlights can have a different configuration of lighting fixtures:
• Head optics - a combined low and high beam headlight, separate light sources for low and high beams, as well as a combination of a combined headlamp and an additional high beam headlamp can be used;
• Front parking lights - can be performed in a separate segment of the headlight unit (have its own reflector and diffuser), or be located directly in the headlight, next to the main lamp;
• Daytime running lights - can be made in the form of individual lamps in their own segment of the headlight, but most often they take the form of a tape at the bottom of the headlamp or rings around the headlamps. As a rule, LED DRLs are used in block headlights.
According to the principle of forming a light beam in the head optics of the headlights, the unit, like conventional ones, is divided into two large groups:
• Reflective (reflex) - the simplest lighting fixtures used in automotive technology for many decades. Such a headlamp is equipped with a parabolic or more complex reflector (reflector), which collects and reflects the light from the lamp forward, ensuring the formation of the necessary cut-off boundary;
• Searchlights (projection, lensed) - more complex devices that have become popular in the last decade. Such a headlight has an elliptical reflector and a lens installed in front of it, this whole system collects light from the lamp and forms a powerful beam with the necessary cut-off boundary.
Reflective headlights are simpler and cheaper, but searchlights form a more powerful light beam, having smaller dimensions. The growing popularity of floodlights is also due to the fact that they are best suited for xenon lamps.
Lenticular optics
According to the type of headlamps used, block headlights can be divided into not four types:
• For incandescent lamps - old headlights of domestic cars, which today are used only for repairs;
• For halogen lamps - the most common headlights today, they combine low price, high luminous flux power and reliability;
• For gas-discharge xenon lamps - modern expensive headlights that provide the greatest brightness of illumination;
• For LED lamps - the least common headlights today, they have a rather high price, although they are durable and reliable.
Modern headlights that meet current standards are divided into two types according to the type of integrated direction indicator:
• Direction indicator with a transparent (white) diffuser - a lamp with an amber bulb should be used in such a headlight;
• Direction indicator with a yellow diffuser - such a headlight uses a lamp with a transparent (unpainted) bulb.
Finally, the block headlights on the market are applicable, most of these devices can only be installed on cars of the same model range, moreover, the design of many headlights is developed individually for one car model. All this should be taken into account when choosing and buying a headlight unit for a car.
Design and features of headlights
All modern headlights have a fundamentally identical design, differing only in details. In general, the device contains the following elements:
1.Housing - the load-bearing structure on which the rest of the components are installed;
2.Reflector or reflectors - reflectors of head light and other lighting equipment, can be integrated into a single structure or made in the form of separate parts, usually made of plastic and have a metallized mirror surface;
3.Diffuser is a glass or plastic panel of complex shape that protects the internal parts of the headlight (lamps and reflector) from negative environmental influences, and participates in the formation of a light beam. It can be solid or divided into segments. The inner surface is corrugated, the high beam segment can be smooth;
4.Light sources - lamps of one type or another;
5.Adjustment screws - located on the back of the headlight, necessary to adjust the headlights.
Searchlight-type headlights differ in design, they additionally have a collecting lens installed in front of the reflector, as well as a movable screen (curtain, hood) with a drive mechanism based on an electromagnet. The screen changes the luminous flux from the lamp, providing switching between low and high beam. Usually, xenon headlights have such a design.
Also, additional elements can be located in various types of headlights:
• In xenon headlights - an electronic unit of ignition and control of the xenon lamp;
• Electric headlight corrector - a geared motor for adjusting the headlight directly from the car, used to achieve the constancy of the direction of the light beam regardless of the load of the car and driving conditions.
Installation of headlight units on a car is carried out, as a rule, with two or three screws and latches through sealing gaskets, frames can be used to achieve a certain decorative effect.
It should be noted that the production of headlights, their configuration, the composition of lighting fixtures and characteristics are strictly regulated, they must comply with the standards (GOST R 41.48-2004 and some others), which is indicated on their body or diffuser.
Selection and operation of headlights
The choice of headlight units is limited, since most of these lighting products for different car models (and often for various modifications of the same model) are incompatible and not interchangeable. Therefore, you should buy headlights of those types and catalog numbers that are designed for this particular car.
On the other hand, there is a large group of universal headlights that can be installed instead of standard headlights or even conventional headlights on domestic cars, trucks and buses. In this case, you need to pay attention to the characteristics of the headlight, its configuration and marking. According to the characteristics, everything is simple - you need to select headlights for 12 or 24 V (depending on the supply voltage of the vehicle's on-board network). As far as configuration is concerned, the headlamp shall contain the lighting components that must be on the vehicle.
Particular attention must be paid to the type of light source in the headlight - it can be a halogen lamp, xenon or LEDs. According to the standards, xenon lamps can be used in headlamps designed only for this type of light source. That is, self-installation of xenon in ordinary headlights is prohibited - this is fraught with serious penalties.
To make sure that the headlight is compatible with certain types of lamps, you need to look at its marking. The possibility of installing xenon is indicated in the marking with the letters DC (low beam), DR (high beam) or DC / R (low and high beam). The headlamps for halogen lamps are marked respectively HC, HR and HC/R. All headlamps provided in this headlamp are marked. For example, if there is one halogen lamp and one xenon lamp in the headlight, then it will be marked with the type HC/R DC/R, if one halogen lamp and two xenon lamps are HC/R DC DR, etc.
With the right choice of headlights, the car will receive all the necessary lighting equipment, will comply with current regulations and ensure safety on the roads at any time of the day or night.
Post time: Aug-21-2023