Car headlight light distribution performance

1. Subject content and scope of application
This standard specifies the light distribution performance, test methods and inspection rules for automotive headlamps.
This standard applies to all types of headlamps used in M ​​and N vehicles.

2. Reference to the number, position and color of external lighting and signalling devices of GB4785 cars and trailers

3. Terminology 3.1 The distribution of luminosity (illuminance or luminous intensity, etc.) of visible light emitted by a light distribution fixture.
3.2 Low-beam A close-range illumination beam that is used to make the other party dazzling or uncomfortable when there are other road users in front of the vehicle.
3.3 High beam The long-distance illumination beam used when there are no other road users in front of the vehicle.
3.4 Lens A lens that is combined by one or more optical units, depending on the light distribution performance requirements.
3.5 Light group A combination of light mirrors, mirrors and light sources (bulbs or light filament assemblies).
3.5.1 Closed lighting groups are combined into a non-detachable overall lighting group.
3.5.2 Semi-enclosed light group The light mirror is fixedly combined with the mirror, and the light bulb can be replaced and replaced.
3.6 Closed headlights use headlights of enclosed light groups.
3.7 Semi-closed headlights.
Headlights with semi-closed lighting groups.
3.8 Low beam or high beam generated by only one filament in a single beam.
3.9 Two beams In a group of lights, two filaments can be illuminated separately, one for low beam and the other for high beam or auxiliary beam designed as needed.
3.10 Voltage (in V) indicated on the nominal voltage bulb (closed light group).
3.11 The power (in W) of the nominal power bulb (closed lighting group) or its packaging.
3.12 Test voltage The terminal voltage used to test the photoelectric parameters of the lamp or group of lights.
3.13 Standard Bulbs Test light distribution lamps with colorless bulbs and reduced filament geometry tolerances. Each model's standard bulb specifies only one nominal voltage.
3.14 Standard headlamps are equipped with standard bulbs with an effective light transmission diameter of not less than 16Omm. The maximum light distribution performance is not more than 90% of the maximum value specified in this standard. The minimum value is not less than 120 of the minimum specified in this standard. % of the headlights.
3.15 Luminous flux Luminous headlamps (or other automotive luminaires) The luminous flux of the bulb specified during the light distribution test.
3.16 Screen of the light distribution screen to test the light distribution performance of the luminaire.
3.17 The cut-off line of the light-dark cut-off line is projected onto the light distribution screen, and the line of light and darkness that the eyes feel is sharp.
3.18 Positioning the light on the light distribution screen when the light distribution test is performed.
3.19 The characteristic axis of the reference axis automotive luminaire, as indicated by the manufacturer on the drawing.
3.20 The intersection of the reference center reference axis and the surface of the lens.
3.21 HV point, hh line and vv line 3.21.1 HV point the horizontal line of the reference center to the foot of the light distribution screen.
3.21.2 The hh line crosses the horizontal line of the HV point on the light distribution screen.
3.21.3 The vv line passes the vertical line of the HV point on the light distribution screen.

4, the same type of headlamp headlamp <br> provisions did not differ in the following main areas:
a. trade name and trademark;
b. characteristics of the optical system;
c. an additional attachment that changes the optical effect by reflection, refraction or absorption;
d. Provide a low beam, or a high beam, or both.

5. General Provisions 5.1 Headlamps shall be designed and manufactured to ensure that, under normal conditions of use, even if subjected to vibration, the requirements for use and the performance of light distribution in accordance with this standard are met.
5.2 For the installation of the bulb of the semi-enclosed headlight, it should be able to fit the bulb in the correct position even in the dark, that is, the positioning pin can accurately enter the positioning groove (the size fits properly), and when the bulb is installed incorrectly The position will be significantly skewed.
5.3 The light color and chromaticity characteristics of the front light shall comply with the provisions of GB4785.

6. Closed light groups and bulbs used in headlamps 6.1 Closed headlights used in enclosed headlamps shall comply with the requirements of Table 1.

Table 1

Note: 1) The specification power and other regulations are tentatively tested.
2) Refer to the incandescent lamp for its light transmission diameter or size.
3) A closed lighting group with a nominal voltage of 24V is under study.
4) The power tolerance only specifies the maximum value, and the lower limit amplitude is based on the minimum values ​​of Tables 3 and 4.

6.2 The bulb products used in semi-enclosed headlamps shall comply with the requirements of Table 2.

Table 2

Note: 1 In the “Under test voltage” column, the R2 lamp is the data at the nominal voltage.
2 The data in brackets is only suitable for vehicles other than cars.

7. Light distribution performance 7.1 The light distribution of the headlights should be such that the low beam has sufficient illumination and is not dazzling, and the high beam has good illumination.
7.2 The light distribution performance shall be measured on the vertical light distribution screen of the HV point 25m before the headlamp reference center. The specific arrangement of the light distribution screen is shown in the figure.

7.3 Light distribution requirements for low beam 7.3.1 On the light distribution screen, the low beam should produce a clear cut-off line. The horizontal part is on the left side of the vv line, and the right side is a diagonal line up 15° from the horizontal line, or upward. A 45° diagonal line to a vertical line with a vertical line of 25cm to the horizontal.
7.3.2 The illumination limit on the light distribution screen shall comply with the requirements of Table 3.

table 3

Note: 1) Single beam is 0.3 and double beam is 0.4.
2) 2E 50R is 5OR measured illuminance.