Heavy Truck Composite Leaf Spring Line in China

Illustration notice. Process illustrations are not verified photographs of this installation.

Project reference basis. Figures and configuration details are reported in the supplied project brief. They are reference values for the stated application, rather than verified acceptance results or a guarantee for another installation. Confirm the source records, material, tooling, operating schedule and test method when assessing a comparable project.

Project configuration and outcomes described in the supplied project brief.

A leading national commercial heavy-duty truck manufacturer in Shandong deployed Haifeng’s 3,000-ton active-leveling composite compression press line across its chassis manufacturing plant. The project was commissioned to mass-produce single-leaf parabolic composite leaf springs for front steer axles on next-generation heavy logistics prime movers.

Prior to this installation, the manufacturer utilized multi-leaf 60Si2Mn forged steel springs. The steel spring assemblies added 138 kg of parasitic unsprung mass per vehicle, penalizing fuel efficiency and generating severe inter-leaf frictional squeak. Initial trials with generic compression presses failed because parabolic springs feature extreme thickness tapers (ranging from 18 mm at ends to 65 mm at the center clamping boss). This asymmetric mass created high off-center platen tilting (exceeding 0.35 mm), causing interlaminar thickness variations that failed fatigue testing under 300,000 cycles.

Haifeng engineered a heavy-tonnage compression molding cell centered on the HF-PCM3000-AL platform. Featuring closed-loop four-corner active hydraulic leveling (within ±0.018 mm) and rapid 1.8-second full-pressure ramping, the supplied brief reports processing 68 wt% glass prepreg packs, a front-axle spring assembly mass reduction from 138 kg to 18 kg (120 kg), and 1 million fatigue cycles for the specified spring test configuration.

Concept illustration: Generated concept illustration for process discussion; not a photograph of the specified machine, a customer facility or a delivered project.

Configuration reported in the supplied brief.

Haifeng engineered an automated high-precision compression molding cell tailored for heavy variable-thickness suspension springs. High-strength unidirectional continuous glass fiber epoxy prepreg sheets are cut by automated ultrasonic cutters and stacked by six-axis robots into calibrated parabolic charge packs.

The charge pack transfers into the 3,000-ton press bed via robotic loading grippers, placed precisely inside forged steel tooling heated to 150°C ± 1°C. The press descends at 400 mm/s. Upon initial contact, four high-pressure digital servo cylinders located at the platen corners engage, ramping to full 30,000 kN clamping force in 1.8 seconds.

Real-time optical linear encoders feed position data to the PLC at 1 kHz, correcting platen parallelism to within ±0.018 mm despite severe off-center tipping moments from the thick central boss. The 12.0 MPa cavity pressure forces epoxy through dense roving bundles across a 180-second isothermal cure. Following automated unclamping, bottom ejector pins raise the cured spring for robotic extraction and automated edge-milling, producing finished springs weighing just 18 kg.