Design of Automobile Lamp Inspection Fixes

As a functional part and an important appearance part of the vehicle, how to control its matching with the vehicle is one of the key control projects of the main engine factory and the lamp industry. At present, the most simple and economical way is to use special inspection tools for sampling control. Beijing Jingke Xingye Technology Development Co., Ltd. has the comprehensive strength of design, manufacture, assembly, debugging and measurement of a full set of automobile inspection tools, and has developed various automobile parts and assembly inspection tools, including: welding assembly, front and rear windshield, front and rear lamp assembly, floor assembly, four-door and two-cover assembly, instrument panel assembly, door inner guard panel assembly, bright trim strip, glove box assembly, coat rack assembly, sunroof assembly, front and rear bumper assembly, opening inspection fixture, pipeline inspection fixture, measuring bracket, tooling fixture, etc.

Next, Jingke Xingye will briefly introduce the design and manufacture of special inspection tools for car lights.

1. Gage composition

The lamp inspection tool can reproduce the state of the lamp installed on the car body, and can directly or indirectly measure and evaluate the dimensional relationship (gap, surface difference) between the car body and the lamp by using the size detection tool. It is mainly used for the determination and adjustment of mold accuracy in the production preparation stage and the daily management of dimensions after mass production.

The lamp checking fixture is mainly composed of the main body and the auxiliary checking fixture. At the same time, the following basic information shall be clearly reflected on the checking fixture (Fig. 1):

① Datum plane in height direction (y)

② Datum plane in depth direction (z)

③ Datum plane in width direction (x)

④ Auxiliary gauge

Mounting part of lamp body

⑥ Body surface

⑦ Coordinate bold line (indicates line name)

Fig. 1 Schematic Diagram of Gauge

The main body of the checking fixture is the main frame of the checking fixture, including the base (reference plane) of the checking fixture, the body surface and the lamp mounting part. Generally speaking, the base and the body surface are made of epoxy resin or aluminum and iron materials. When using iron materials, attention should be paid to the rust caused by long-term use and surface treatment should be carried out.

The most important part of the design of the lamp inspection tool is to fully reproduce the actual installation method of the lamp, so the structure of the lamp installation part needs to be located according to the requirements of GD & T drawings and the actual loading state position structure. According to the datum distribution mode, it is divided into surface datum (hereinafter referred to as A1, A2 and A3), hole datum (hereinafter referred to as B) and auxiliary datum (hereinafter referred to as C). According to A1, A2, A3,B,C, etc., install the parts on the gauge from the x, y, z directions, and set the tolerance of these dimensions to ± 0.1mm.

In the installation structure of lamps and lanterns, bolts, nuts and holes (fixed with screws) and feet are generally used according to the actual loading state (Figure 2).

Fig. 2 Installation structure example of lamp

2. Bolt (rod) positioning method (Figure 3)

Fig. 3 Bolt Installation

3. Positioning method of holes (holes at lamps and positioning screws for checking fixtures) (Fig. 4)

Figure 4 Hole Mounting

Due to the requirements of the lamp body installation must be able to withstand the body installation strength of 12N m(122kgf cm) above the rotation force. Therefore, when the material of the main body is made of resin material, metal parts should be used to make the lamp mounting part, so as to prevent the lamp from falling off and turning when loading and unloading.

The main function of the auxiliary inspection tool is to form a large surface of the lamp wiring surface difference benchmark (generally 0mm) and a certain gap between the products suitable for measurement (generally 2~3mm). By measuring the gap, the value of the surface difference to determine whether the measured lamps meet the requirements of the standard lamps.

Since a measuring tool such as a vernier caliper is used, it is necessary to provide a flat surface portion of 30mm on a large-surface connection surface (FIG. 5).

Fig. 5 Cross-section of auxiliary gauge

Material selection of SMC resin and meet the standard of resin.

When the sub-gauge is thin and the strength is problematic due to the shape of the lamp, the section difference shall be set at a certain place on the large surface connection surface to deal with it (Fig. 6)

Fig. 6 Auxiliary Checking Fixture with Segment Difference

Except for special instructions, the auxiliary inspection fixture generally does not need surface treatment, but the screws fixing the auxiliary inspection fixture and the main body need to be electroplated or SUS material to prevent rust. According to the shape of the large surface of the lamp, sometimes it is impossible to form an ordinary auxiliary inspection fixture (the R surface of the large surface of the lamp is large, when it is impossible to form the wiring of the light distribution mirror surface, etc.) it is necessary to use a cross-sectional inspection tool (fig. 7). materials with certain hardness such as iron are generally considered for material selection, and surface treatment such as spraying is required to prevent rust.

Fig. 7 Use Example of Section Checking Fixture

In the design of inspection tools, attention should also be paid to a certain working space, which can be transported and some body parts should be borrowed to reflect reproducibility.

4. Conclusion

In the batch production and trial production stage, the lamp inspection tool is mainly used for full measurement of small batch products and sampling measurement after mass production. It is often used to measure the key characteristic points with special plug gauge (specification is 0.5~5.5mm) and height ruler (specification is -10.0~10.0mm). Its simplicity, speed and accuracy have brought great benefits to the main engine factory and lamp suppliers. Therefore, it is very important to design and manufacture a good pair of inspection tools for the main engine factory and lamp suppliers, especially a pair of reasonably designed inspection tools can greatly reduce the cost of lamp suppliers.

Relying on independent research and development and technological innovation, Jingke Xingye started from the rearview mirror, expanded to car lights, front hoods, bumpers, doors, and vehicle inspection tools. It has won the confidence and capital to compete with outstanding foreign companies. Higher cost-effective products serve various well-known automobile OEMs, FAW-Volkswagen, FAW Toyota, BAIC Group, Beijing Benz, Beijing Hyundai, Great Wall Motors, Wuling Motors, etc., greatly reducing the cost of branded cars.