Headlamp cleaning system
Headlamp cleaning system
Here you will find useful information and important tips relating to the headlamp cleaning system.
Headlamp cleaning systems improve visibility in the dark and prevent dazzling of oncoming traffic through stray light. On this page, find out about the structure of headlamp cleaning systems and how they work. You can also find useful tips here on using these safety systems along with information on troubleshooting in the event of malfunction.
Important safety note
The following technical information and practical tips have been compiled by HELLA in order to provide professional support to vehicle workshops in their day-to-day work. The information provided on this website is intended for suitably qualified personnel only.
TABLE OF CONTENTS
HEADLAMP CLEANING SYSTEM: GOOD TO KNOW
Headlamps which provide intensive light are more prone to glare through build up of dirt. For this reason, the legislator prescribes headlamp cleaning systems for such powerful lights, as well as automatic headlamp leveling. The cleaning principle of a "water jet" has long replaced the "wiper" principle for headlamp cleaning.
Clean headlamp
- Maximum visibility
- No glare
Dirty headlamp
- Less visibility
- Increased glare
Deflection and absorption of light beams by particles of dirt
Influence of dirty headlamps on driving safety
1. Clean headlamp: Maximum visibility, no glare
2. Dirty headlamp: Less visibility, increased glare
HEADLAMP CLEANING SYSTEM (HLCS) FOR CARS: DESIGN
A complete HELLA headlamp cleaning system is made up of the following components:
- Whirl chamber nozzles with a range of jet stream patterns in stationary or telescopic extendable nozzle systems
- Switching valves / central valve
- Hose assembly with plug-type system
- Water reservoir with centrifugal pump
- Triggering: Electronic timer or relay
System design of a headlamp cleaning system:
1 Timer, 2 Water reservoir with motor pump, 3 Nozzles or telescopic nozzles, 4 T-piece or central valve
Circuit diagram of a headlamp cleaning system
CLEANING PRINCIPLE: FUNCTION
Function using the example of a telescopic nozzle system
The cleaning fluid is sprayed at high pressure in the form of cone-shaped drops onto the headlamp cover lens. The cone-shaped drops are formed by means of special whirl chamber nozzles.
The headlamp cleaning system is usually triggered together with the windscreen cleaning system. Every time the driver activates the windscreen washers, the headlamps are automatically cleaned at the same time. This coupling only takes place when the lights are switched on. When the centrifugal pump is triggered, this presses the water into a cylinder, the piston of which has a nozzle head attached and is extended against a pressure spring, bringing the nozzles into their working position.
Until the working position is reached, a valve ensures that the movement only is carried out first without any water escaping from the nozzles. When the working position has been reached, the valve opens and water is sprayed onto the headlamps. Once the pump has been switched off, the return spring moves the piston back into its initial position. One washing impulse takes approx. 0.5 s for stationary nozzles and approx. 0.8 s for telescopic nozzles (due to the time required for extension).
The function of telescopic nozzles: The impact of the "micro drops" on the cover lens has the effect of loosening and rinsing off the dirt.
TIPS ON DEALING WITH HEADLAMP CLEANING SYSTEMS: PRACTICAL TIPS
When some cleaning agents are used, excess dosing can result in heavy foam formation since this effect is exaggerated even more by the whirl chamber nozzles.
- The foam can stick to the headlamp for some time, causing problems with the light distribution.
- For this reason care should always be taken to mix the water and cleaning agent to the right mixing ratio.
FAULTY HEADLAMP CLEANING SYSTEM: CAUSE OF FAILURE
CHECKING HEADLAMP CLEANING SYSTEMS: TROUBLESHOOTING
If the centrifugal pump does not work (noise can be clearly heard during normal operation) when the washing function has been activated, the voltage supply including the fuse must be checked.
If the water spray cone is only one-sided or extremely weak although the pump is working, this could be caused by the following:
Inverse polarity of the motor pump:
Check the polarity, since centrifugal pumps can work in both directions of rotation but with different hydraulic power.
System is not bled:
Bleed the system completely by activating the system several times without a break.
Hose is kinked or leaking:
Check the routing of the hose and change if necessary. Seal leaks and/or repair hose.
Nozzles or valves are blocked:
Remove foreign particles by rinsing the system.
Component parts are frozen up:
Increase amount of anti-freeze. Freezing will not damage the components, however.
If cleaning efficiency is still not as good as it should be, check the nozzle setting and/or set according to manufacturer's specifications.
HEADLAMP CLEANING SYSTEM OBLIGATION: REGULATIONS
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