Rear Axle Suspension Pressure Control During Interlock Shifting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicles with multiple suspended rear axles experience traction force interruptions during shifting processes due to interlocking shifting elements, leading to increased slippage and reduced driving stability, especially in varying driving conditions.
Innovation Solution
Implementing a control system that adjusts the pressure of pressurized suspension elements on each rear axle using electric motors and control units to compensate for traction force interruptions by redistributing axle loads, utilizing interlocking transmissions with claw-type shifting elements to maintain traction and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an interlocking shifting element is used in the transmission of each rear axle, then gear shifting is enabled, but traction force interruption occurs during shifting
Solution Approach 1:
The control device detects the shifting process in advance and redistributes axle loads before the traction force interruption fully occurs. By proactively adjusting the suspension elements and motor torques during the shifting event, the system prepares the drivetrain to maintain overall traction despite the local interruption at the shifting axle.
Solution Approach 2:
The system dynamically changes operational parameters during shifting by adjusting the torque distribution among multiple rear axles and modifying the suspension element pressures. This parameter adjustment allows one axle to compensate for the traction loss at the shifting axle, maintaining overall vehicle propulsion continuity.
2Reliability
If increased torque is applied to the other driven rear axle to compensate for traction force interruption, then traction is maintained, but slippage occurs depending on operating and driving situation
Solution Approach 1:
The control device dynamically adjusts multiple parameters simultaneously: increasing torque to the non-shifting axle while reducing pressure in the suspension element of the shifting axle. This coordinated parameter change optimizes the torque distribution and axle load allocation to prevent slippage during the compensation phase.
Solution Approach 2:
The system employs dynamic control where the torque distribution and suspension pressures are continuously adjusted based on real-time detection of the shifting process and driving conditions. This dynamic adaptation allows the system to respond to varying operating situations and minimize slippage through real-time optimization.
3Reliability
If the pressure of the pressurized suspension element is increased to reduce slippage, then traction is improved, but the axle load increases
Solution Approach 1:
The system applies different suspension pressures and torque levels to different rear axles based on their individual roles during the shifting process. The non-shifting axle receives increased torque and optimized suspension pressure for maximum traction, while the shifting axle has its pressure reduced. This localized quality adjustment optimizes overall traction without unnecessarily increasing the load on all axles.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Minimizes traction force collapses and reduces slippage by dynamically adjusting axle loads based on driving conditions, enhancing driving stability and maneuverability, particularly in slippery or uneven terrain.
Implementation Method 1
the pressure of the pressurized suspension element of the rear axle being shifted is reduced and the pressure of the pressurized suspension element of the other rear axle is increased
Data Source
AI summary
For a vehicle with a front axle (1) and at least two suspended rear axles (2, 3), a level relative to the roadway can be adjusted by controlling pressurized suspension elements (7, 8) arranged on the rear axles (2, 3), where the rear axles (2, 3) are each driven electrically by an electric motor (10) controlled by at least one control unit (11). A separate transmission (13) with a shifting element that operates with interlock is associated with each rear axle (2, 3), and at least one control device (15) is associated with the rear axles (2, 3). The control device is designed to detect the occurrence of a shifting process at one of the rear axles (2, 3), and as a function of the occurrence of the shifting process, to reduce the pressure of the pressurized suspension elements (7, 8) of the rear axle (2, 3) being shifted and to increase the pressure of the pressurized suspension elements (7, 8) of the other rear axle (2, 3).