Powerful high-voltage batteries are the heart of electric vehicles. To ensure the functional safety of the vehicle and to maintain the service life of the battery in the long term, a stress-free connection is crucial. This is where the tolerance compensation systems from WITOL come into play.
Battery connection of the high-voltage storage unit
High-voltage batteries, which are used in the electrified automotive industry, are rigid components with very high tolerances that have to be connected to the body. The high-voltage battery is a very sensitive component. Even a minimal distance between the contact surfaces can lead to unequal bending forces and stresses during assembly.
The bodywork, on the other hand, is comparatively susceptible to torsion, so considerable deformation of the bodywork and impairment of the gap dimensions and joint patterns can already occur during installation. Tension-free attachment of the battery to the vehicle underbody is therefore crucial for flawless quality.
WITOL has developed particularly robust tolerance compensation systems for the battery connection. The WITOLs are preassembled either on the battery housing or on the vehicle body. In the bolting process, the tolerances are compensated in the axial direction. By means of suitable slotted or square holes and sufficiently large screw heads, even compensation radially to the screw axis is possible.
Internal connection of the individual battery cells
The internal connection of the individual cell modules to the battery housing is also subject to tolerances. If the component is screwed together conventionally, the tolerances between the cell modules and the cooling base are usually compensated for with cost-intensive heat-conducting medium. This leads to poorer heat dissipation and higher vehicle weight. In addition, high compressive stresses can occur, which lead to deformation and insufficient thermal management of the high-voltage battery.
With the same active principle that is already used for the external connection of the high-voltage battery, WITOL tolerance compensation systems equalize the gap between the cell module and the housing flange without stress. The negative effects that arise in the conventional bolting process are thus effectively eliminated. The use of a universal screw connection also makes it possible to remove and install individual cell modules during servicing.
Roof rails as an eye-catcher and functional element
Roof rails are a popular method of attaching sports equipment or other bulky loads to cars. In addition to the fastening, one criterion in particular is now increasingly decisive for the roof railing: the design. The railing can be individually adapted to the vehicle design and enhance it. From a practical point of view, it allows convenient transport of loads that turn out too big for the trunk.
The challenge here is that car roofs must not be deformed under any circumstances, not even by an attached roof railing. In addition, the roofs must be 100 percent leak-proof – this factor must not be influenced by a roof railing. In addition, extremely strong forces act on the railing and its screw connections in tight curves or during emergency braking. The roof structure must be attached to the railing in such a way that no additional safety risks arise for all road users in these hazardous situations.
Fastening solutions from WITOL
The fastening solutions from WITOL address this problem. They enable tight and at the same time stress-free fastening of the roof railing – both on car roofs with roof duct and on laser-welded models. The railing is firmly and securely connected to the supporting structure of the car body via several screw points.