Assembly Battery Pack

The innovative high-voltage components of an electric vehicle present new challenges for production assembly. It is not only for the integration of high voltage components that new solutions must be developed, it is also when dealing with the whole topic of high-voltage in work processes.

Electric vehicles have significantly higher voltages (up to 800 volt direct current). This necessitates higher safety requirements for employees in assembly processes.

During battery assembly, the cell module is assembled first. The individual battery cells are stacked, placed in the battery housing and then connected to the battery management system. Next the current collector is connected to the power supply, connections are checked and the housing closed. Then power supplies and contacts are connected before the finished modules can be tested. The individual cell modules are connected to a floor element via contact rails and assembled with fasteners. Electronic boards and seals can then be attached.

• Installation of the module requires complete traceability.

• The battery size and resulting high number of assemblies is usually automated and has short cycle times.

• Avoidance of particle contamination.

• Safety for operators: Contact with live power circuits can cause serious, even deadly injuries.

• DEPRAG insulation concept:  
  - special ceramic and synthetic parts
  - protects against voltage of up to 1000 volts

• Multi-spindle version for short cycle times

• Gripper jaws to avoid dropping the screw

Screw feeding systems to increase productivity: Step feeding system eacy step feed

Assembly Power Electronics

When assembling electronic components and modules in the field of power electronics and particularly in the field of high-voltage components, technical cleanliness is of utmost importance: Particle contamination can quickly lead to insulation errors, mechanical contact blockages or undermining or interruptions of light barriers for highly sensitive components in power electronics.

The critical particles may be created directly within the process, due to both the high number of components introduced into the process and the assembly steps themselves. Conductive particles in particular may cause high voltage arc flashes and short circuits.

Due to the complex design of individual components the operator may often have to deal with screw positions which are difficult to access, which must also be assembled in a specific sequential order.

• Technical cleanliness

• Difficult to access screw positions

• Worker safety

• Safety-critical assemblies of category A

• Correct sequential order of assemblies

• ESD design

Assembly Components

It is usually screw joints of the category A in accordance with VDI standard 2862, which are used for the assembly of elements in the automotive industry. Process reliability is of utmost importance and all processing steps must be documented and monitored.

The assembly process entailed for battery module or power electronics with a wide variety of components is highly complex: numerous screws must be assembled in the correct order to guarantee a consistent pre-load force.

Within lightweight construction, above all in the field of E-mobility, aluminium, other lightweight metals and synthetic materials are increasingly used. Widely varying torques are commonly a result of the frequently employed direct assemblies. Due to different material characteristics, settling conditions can also vary. As these are predominantly conductive connections and conductivity must be guaranteed, adaptive screwdriving procedures are recommended for reliable detection of the seating point.

• Settling conditions when using varying materials

• Screw tightening in a prescribed order to guarantee consistent pre-load force

• Safety-critical assembly of category A

EC-Servo technology with DEPRAG CFC Clamp Force Control

Adaptive screwdriving procedure DEPRAG CFC Clamp Force Control: Despite fluctuating tightening torques, the procedure guarantees reliable detection of the seating point and ensures a consistent final position for the subsequent final tightening resulting in a constant pre-load force.

Process monitoring

Position control stand (PKS)
Position control gantry (PKP)
Camera systems

Process visualisation with DEPRAG Operator Guidance

Digital assembly guides for operators: error-free assembly and traceability of all processing steps, MES communication

Assembly Bodywork Construction and Battery Housing

Lightweight construction and the subsequent weight savings involved are amongst the greatest driving forces for innovation, not only in bodywork construction, but also in the production of battery housing for E-mobility.

As the weight of the battery is relatively high, the weight of the bodywork and furnishings must be kept as low as possible. Therefore lightweight construction materials are utilised which will reduce the net weight of the vehicle and also reduce energy consumption.   

Assembly and joining technology is experiencing a radical transformation due to lightweight construction – the material mix determines the process and requires the highest possible levels of flexibility from the fastening system.

The achievable travel range is today the decisive factor when purchasing an electric vehicle. Lightweight construction to reduce energy consumption remains a hot topic within the field of E-mobility. The established approaches for bodywork construction are adopted. Whether aluminium design or a sophisticated multi-material mix, DEPRAG has the solution.

ADAPTIVE DFS DEPRAG FASTENING SYSTEM – Screwdriving system for lightweight construction assemblies

Our many years of experience and the continual expansion of our global knowledge has placed DEPRAG as a forerunner and leading innovator in the development of FDS smart tools. This is attributable not least, to our patented drive technology. The hundreds of systems operating at automobile manufacturers around the world are impressive evidence of this.

The selection of the correct fastening technology for lightweight construction is of utmost importance and consequently flow drill screw assemblies are the established technology for bodywork construction in the automobile industry. The adaptive assembly unit Adaptive DFS combines EC Servo screwdriving technology with EC Servo feed technology. This enables automatic piercing detection throughout the flow drill assembly, independent from screw and component tolerances. The processing parameters are adjusted automatically and the processing sequence is continually optimised. The screwdriving system can also easily be connected to a robot. There is no longer any need for complicated costly parameter adjustments.

• Top process reliability
• Shortest possible cycle time
• Optimised funnel forming
• Eliminates thread damage
• Low stress on screw and component
• Minimum set-up time
• Ready for new materials, fasteners and joining methods