The Design Concept of Auto Lighting & Its Prototyping

Posted on: Nov 13, 2017, | By Tony, WayKen Project Manager

There are headlights, taillights, fog lamps and so on. All kinds of lights have different uses. Did you do any research on the effects of headlights if you are automotive lighting manufacturers ? Do you understand the prototype manufacturing process of the car lamp design stage? WayKen Rapid prototype manufacturing will answer for you.

1. Design Requirements for Automotive Lighting

1.1 Headlamp

Car headlights, also known as car headlamps, as the eyes of a car, not only related to the external image of a car owner but also close to the safe driving during night driving or bad weather conditions. The material of the headlight needs to ensure that the vehicle has a bright and steady illumination while driving at night so that the driver can clearly distinguish objects within 100 meters. At the same time, there must be an anti-glare device, to ensure the safety of driving at night.

Materials and performance requirements:

Part Name Production material Prototype material Property requirement
Lens PC PMMA、 PC Scratch resistant, transparent, UV stable
Bezel PC、PCHT、PBT、PBT/PET PMMA 、ABS Heat resistant, metalized, high surface quality
Lightguide PC PMMA 、PC Transparent, UV stable
Reflector PC、PBT、PPS、BMC ABS 、Aluminium High heat resistant, high rigidity, metalized, high impact resistant
Housing PP+T40、PP+T20 ABS Dimensional stability, heat resistant

1.2 Taillamp

The taillight is a signal light that transfers brake, steering and other important information. Due to its high frequency of use in the city, the performance requirements of the material are also high. The material must have high heat resistance, good processability, wettability and bright colors.

Materials and performance requirements:

Part Production material Prototype material Property requirement
Outer Lens PMMA PMMA PC Scratch resistant, transparent, UV stable
Housing ABS、PC/ABS、ASA ABS Dimensional stability, heat resistant
Inner Lens PC、PCHT PMMA PC Transparent, UV stable
Frame ABS ABS Dimensional stability
Lightguide PC PMMA PC Transparent, UV stable

1.3 Fog lamp

In the case of low visibility, such as rain and fog weather, the role of large headlights is limited. So the fog lamp needs to pass through the fog and other obstacles to ensure the normal line of sight. Because of the high power and temperatures of the fog lamps, the materials needed also should have high heat resistance.

Materials and performance requirements:

Part Production material Prototype material Property requirement
Lens PC + hard coating、PMMA PMMA PC Scratch resistant, transparent, UV stable
Housing PCHT、PEI、PBT/ASA、LCP、PC/ABS ABS Dimensional stability, heat resistant
Reflector PCHT、PEI、PC ABS High heat resistant, high rigidity, metalized, high impact resistant

 2. Automotive lighting prototype manufacturing

Currently, the main technology used in the field of automotive lighting prototype includes 3D printing, CNC machining, silicone mold and rapid aluminum mold, which have their own advantages. The following are the different technical applications of the different stages of development based on WayKen’s years of experience in providing rapid prototyping services and automotive prototyping for the design and development of automotive lamps:

2.1 Concept and engineering stage:CNC machining

CNC headlamp prototype machining is characterized as high precision, fast response and short cycle (1-2 weeks of delivery), which makes it possible to machine complex shapes in one piece of material. Usually, in concept stage (conceptual stage) and engineering stage (engineering design stage), it is necessary to make an appearance or function model for a part of the headlight, such as a light pipe or a reflector cup. This demand often requires the ability to produce high-precision prototypes in the shortest cycles with real materials, and CNC is the best choice.

Due to the complicated structure of the lamp, there are many optical details and undercuts, and even high-precision 5-axis CNC can’t process the whole part all at once. CNC programming engineers, who have rich experience in prototype lamp manufacturing, need to analyze the feasibility of machining after obtaining the drawings of the lamp design. For those parts that can’t be processed integrally, they need to provide the solution for disassembly processing, especially for critical surfaces.

In the later stage of prototype production, deburring, polishing, bonding and painting, and other handmade post-processing work is particularly important, will directly determine the final appearance.

2.2 Low volume testing stage: Silicon casting

There is no draft consideration for silicone mold as it is one of the simplest ways in the rapid tools, with good flexibility and replication performance. Therefore, this technology is widely used in the low volume production of car lamps.

For low volume headlamp parts using silicon mold, it is particularly important to choose the manufacturing methods and materials in order to meet the appearance and performance requirements of different parts.

For LENS and BEZEL, which require mirror polishing, we usually choose CNC to make a prototype of PMMA with the high-quality surface finish. The silicone mold made by such method can ensure the perfect appearance of the casting.

For structural parts with fewer appearance requirements, such as housing, we use RP technology such as SLA to make the prototype and choose AXSON PX223 with excellent temperature resistance as the casting material.

Following is a typical project for reference:

3. Small Batch Loading Test: Aluminum Tool

Rapid mold materials are mainly soft steel (for example, P-20) and aluminum (such as 7075 T-6 Aerospace grade aluminum). Compared to hard steel, it can increase the processing speed by 15% to 30%, and the polishing time can be 3 to10 times faster with lighter weight, so as to reduce the cost of making the mold and shortens the cycle. In addition, the rapid aluminum tool facilitates temperature control, allowing faster cycle times and eliminating plastic stress.

As the car is in the development stage, it is necessary to evaluate its processing cycle as well as the manufacturing cost, and these can be obtained through rapid aluminum tooling. For example, engineers can produce small batch lamps through a rapid aluminum tool for loading tests or upfront market launches. The biggest advantage of rapid aluminum tooling is that it has the real material and real structure. Not only the reaction cycle is fast, but also the production cycle and cost can be evaluated reasonably and truly. Below is the project cycle of WayKen’s rapid taillight production of aluminum parts:

Compared with ordinary steel mold, the two materials made almost the same surface quality. The life of aluminum mold is related to the complexity of the product, although far lower than the steel mold, but also can achieve no less than 1000 times of service life, which is more than enough for the initial loading test.

Following is an aluminum tool table on the taillights parts:

Hi,click here to send us a message.