When it comes to the core issues of new energy vehicles, the battery cannot be overlooked. As the power source of new energy vehicles and the most critical component, how to improve the production assembly quality and efficiency of batteries is of utmost concern.

Faced with the increasingly complex challenges of bolt tightening in battery packs, Danikor has explored a variety of reliable screw feeding and tightening solutions to achieve safer, more efficient, and more stable intelligent assembly of battery packs, safeguarding the enduring power source of new energy vehicles.

Challenge 1: High Number of Shell Bolts and High Beat Requirements

Battery pack shells commonly use bolt specifications of M5 to M6, and the quantity is significant. Additionally, the beat requirements are high, and some hybrid battery packs still require manual tightening.

Solution:

Automated Workstation: Pairing with a robot's variable distance structure and using dual-axis or multi-axis synchronous tightening operations can enhance the production line's beat. For different interference conditions, corresponding integrated tightening modules can be selected. In cases of single-sided interference, blow tightening can be used with extended gun head connectors to ensure screw feeding efficiency and stability. For complex interference positions, screws can be delivered through suction. Since shell bolts typically have a larger cap diameter and a smaller length-to-diameter ratio, a swing-arm blow gun head with a screw storage function can be used to increase the screw feeding beat.

Additionally, to address deviations between the shell's through-holes and threaded holes, sleeve floating technology is often employed. This technology allows multi-directional floating to accommodate certain positioning deviations, improving hole entry rates and tightening success rates.

Manual Workstation: Using an integrated handheld module, operators do not need to touch the screws directly. By pairing with a lever to move the module into position and pressing the start trigger, assembly operations can be performed, effectively reducing operator fatigue.

Challenge 2: Difficult Automation Assembly for Long Bolts in Modules

Modules commonly use long bolts with specifications of M5 to M8. The difficulty of automatic screw feeding is higher compared to regular bolts, and the workstation layout can affect the process, especially when long-distance blow feeding increases the difficulty of automatic screw feeding.

Solution: A stepwise screw feeder is used to blow long bolts through a blow tube to a lifting material receiving platform. A gripper picking module is then used to pick up the screws, ensuring that the screw positions are monitored during movement to prevent dropping. Additionally, a custom blow tube manufacturing process is used to create tubes that are both wear-resistant and flexible, avoiding wear and material jams during long-distance conveyance, ensuring smooth blow feeding.

Challenge 3: High Requirements for Bolt Tightening Process

The bolt connections in battery packs play a crucial role in component sealing and assembly fixation. In the automotive industry, these connections are typically defined as A-B level connections, with stringent requirements for tightening quality, especially regarding tightening sequence and residual torque, to ensure uniform stress distribution in the cover tightening process.

Solution: Sensor-based tightening tools, based on self-developed high-precision algorithms, achieve a 6σ precision of ±5% within the full range. Under ±5% process conditions, the CMK is greater than 1.67, ensuring more stable and durable performance. Through various tightening strategies, such as two-step tightening, multi-step tightening, and tightening with reverse loosening for final tightening, or multi-step tightening program control, the bolts can be tightened gradually to the target torque, reducing torque decay and ensuring tightening quality. These tools also feature data collection, upload, and storage capabilities, enabling traceability of tightening results.

Challenge 4: Insulation Tightening for Module Copper Plates

Considering the insulation requirements of battery pack modules, it is essential to ensure insulation treatment during the assembly process to prevent battery damage from short circuits and other safety hazards.

Solution: Special insulation treatment is applied to components such as bits, sleeves, and base plates to protect the batteries or tools from damage. After tightening, insulation treatment is also required at the connection points.