Vibration Management in Vehicle-Mounted Equipment with the Bodyfix Mechanism

In the vehicle-mounted tipper and transport industry, operating time is not limited to the moment when material is unloaded; the time vehicles spend travelling on the road accounts for a large part of the total cycle. Construction-site surfaces, quarry areas, damaged roads and off-road conditions generate continuous, repetitive dynamic shocks and high-frequency vibrations in the vehicle chassis. These mechanical movements cause the tipper body to shake continuously relative to the chassis. If vibration is not brought under control, it can create the conditions for serious fatigue damage in hydraulic and mechanical connection lines over time.

Risks Created by Body Movement While the Vehicle Is in Transit

An empty or loaded tipper body weighing several tonnes makes vertical and lateral micro-movements on the chassis as a result of road shocks. These uncontrolled oscillations accumulate in two main critical areas:

• Cylinder Connection Points: The telescopic cylinder’s top eye and lower trunnion/cradle connections are located at the centre of these dynamic loads. Continuous rocking can cause wear on connection pins, ovalisation of bracket holes and microcracks in weld seams.
• Hydraulic Connection Lines and Hoses: Pressure lines and fittings entering the cylinder have to follow these movements. Repeated tension and bending can lead to material fatigue in the inner layers of the hoses and to trace oil leaks at connection points.

Operating Principle of the Bodyfix Mechanism

Developed within the HMLIFT product family to address this structural risk, Bodyfix is a clamping mechanism with a rubber spring element that secures the tipper body to the chassis while the vehicle is in transit. When the body is closed, the mechanism engages and pulls it down towards the subframe, holding it firmly in place.

The engineering advantages of the mechanism are as follows:

• Flexible Clamping Force: The special rubber block inside the mechanism holds the body firmly while also absorbing sudden shocks transmitted from the road. It prevents the stress concentration that would be created by a completely rigid, non-compliant lock.
• Wear Prevention: By preventing the body from striking the chassis relative to it, the mechanism both protects the service life of the superstructure and reduces mechanical stress on hydraulic connection components.

Calculation of the Clamping Load and Geometric Limits

The clamping force provided by the Bodyfix mechanism is not set arbitrarily; it is optimised according to the structural weight of the body and the position of its centre of gravity. The following basic formulation is used in engineering calculations:

C = (W × A) / B

Where:

• C: Required Clamping Load (kg)
• W: Net Weight of the Body (kg)
• A: Distance from the Body’s Centre of Gravity to the Rear Pivot Axis (Hinge) (mm)
• B: Distance from the Bodyfix Mechanism to the Rear Pivot Axis (mm)

This geometric relationship makes it possible to determine the correct clamping force needed to prevent unwanted body movement caused by road shocks. With an approximate mechanical weight of 17 kg, the system is integrated into the chassis or body structure by welding. Because of its structural movement characteristics, the mechanism is suitable only for rear-tipping system architectures.

Conclusion

Long-term reliability in vehicle-mounted equipment design is not only a matter of generating hydraulic power; it also depends on correctly managing mechanical stresses during non-operating periods. Incorporating vibration-damping elements such as Bodyfix into the system is a complementary engineering approach that extends the field life of hydraulic cylinders and connection components.