Given the rapid advancements in hybrid technology and the global emphasis on new energy policies, automakers are actively exploring new possibilities for fuel-efficient and low-emission hybrid vehicles. DHT (Dedicated Hybrid Transmission) technology is an important enabler for this growing market as vehicles equipped with DHT are not affected by charging duration, thus ensuring a more reliable user experience. This technology also allows for the simultaneous use of gasoline engines and electric motors, enabling efficient power sharing between them. Indeed, hybrid vehicles using DHT technology outperform traditional gasoline vehicles in terms of performance, fuel efficiency, and emissions reduction.
HYCET, a wholly-owned subsidiary of Great Wall Motor, plays a pivotal role in the field of hybrid technology, with a strong focus on transmission system devices. To increase production capacity and meet growing market demands for its L.E.M.O.N. hybrid DHT system, HYCET’s engineering team tasked Comau with designing and developing a high-speed, automated manufacturing solution that would ensure absolute quality in addition to efficiency and scalability.
HYCET’s DHT technology represents cutting-edge innovation in the hybrid vehicle sector and delivers outstanding performance for Great Wall Motor’s DHT system. As our technology partner, Comau’s design and engineering capabilities confirm their exceptional position in this field. Throughout the project implementation phase, Comau adhered to the project schedule despite the recurring impacts of the pandemic, and ensured consistent manufacturing quality. This stability is critical for our production goals, allowing us to meet market demands and maintain optimal manufacturing efficiency.
Wu Hongchao, Vice President of HYCET Technology Co., Ltd.
The Challenge
In early 2021, HYCET began looking for a dependable partner to achieve the industrialization of its self-developed L.E.M.O.N. Hybrid DHT system and enable large-scale production. Aligned with its mission to drive innovation in hybrid vehicles and establish a solid foundation for Great Wall Motors Group in its transition to new energy, HYCET awarded the project to Comau based on the automation company’s deep expertise and strong track-record of innovation in e-Mobility.
Comau was challenged with designing a high-volume, automated assembly line that could ensure strict manufacturing accuracy and product quality requirements, both of which are due to the high integration, intelligence, and adaptability of the L.E.M.O.N. DHT system.
The assembly line design also needed to be inherently flexible and scalable in order to adapt to future changes and upgrades. This meant that Comau would need to meet the manufacturing requirements for the current products as well as prepare for future product upgrades.
At the same time, given the highly competitive market environment, Comau needed to help HYCET achieve its strategic market share objectives. To do so, the team would need to enhance the production line to allow the customer to increase the number of shipments while ensuring product quality and meeting the growing demand for the L.E.M.O.N. DHT.
The Solution
The DHT assembly project features a total of six production lines. Comau has fully designed and deployed all of the necessary components, including the e-motor assembly lines, the gear and shaft assembly lines, the main assembly lines, and the assembly test lines. The system also covers critical processes such as heat insertion, engagement and union, shaft package pressing, and EOL (End of Line) testing, resulting in full-process assembly from individual components to fully functional units.
The application of advanced automation technologies greatly increases production efficiency. For example, Comau’s solution utilizes robot vision guidance technology in the shaft assembly process to accomplish clutch housing and automatic online operations, reducing waiting times and production line downtime while improving process efficiency. To guarantee that parts meet specifications with precise angles, Comau has adopted multi-head automatic shims measurement technology and conducts a double-check process at the shaft package insertion station. As a result, production efficiency is increased and the occurrence of assembly errors is minimized. Additionally, the automated process of fitting five shafts into the housing significantly reduces the need for manual intervention, further enhancing assembly accuracy and overall efficiency.
Finally, Comau used a process-integrated overall station design to guarantee stability and quality in the production line. In the e-motor assembly, for example, the design approach is applied to the rotor sub-assembly and the dual rotor insertion and housing mating stations. This approach saves space and conserves resources on the production line. More specifically, complete automation of component management from the rotor sub-assembly line to the main line eliminates manual handling risks and ensures greater precision and product quality. Servo presses are extensively utilized throughout the project to monitor process parameters, such as force and displacement, ensuring quality control throughout the entire production process and supporting subsequent data traceability.
To enhance scalability and lower the production costs for future DHT product upgrades, Comau has developed inherently flexible stations which grant improved adaptability and efficiency of the entire production line. In total, the line incorporates 12 robots and is equipped with automatic grippers and an automatic assembly tool change, enabling swift adjustment to different product and workpiece sizes. Furthermore, it can seamlessly transition between various types of fixtures during the process, making it easier to customize the line to meet different market needs.
The Results
The successful delivery of this technologically important production line marks a key step in the large-scale deployment of new energy technologies between the two companies. By prioritizing flexibility, automation efficiency, and absolute quality within the manufacturing philosophy, Comau has allowed HYCET to achieve a single-line production capacity target of 150,000 units per year, with a cycle time of less than 113 seconds as part of the 100% error-proof production process. Such impressive results are further aided by the integration of advanced technologies such as advanced vision systems and sensor monitoring.
In addition, Comau has also implemented a MES (Manufacturing Execution System) for the scientific management and scheduling of the production line. This system ensures strict adherence to manufacturing standards and management protocols, thereby providing excellent quality assurance for the L.E.M.O.N. Hybrid DHT.
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