Park Lock Assembly With Inductive Gear Position Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current vehicle transmission park lock assemblies face challenges in ensuring the park lock gear is set in a rotational position that allows the locking pawl to engage directly without interference, leading to potential vehicle movement when shifting from parking mode, and there is a need for efficient detection of rotational speed and proper engagement of the locking pawl with the park lock gear.
Innovation Solution
The implementation of an inductive angular position sensor that monitors the rotational position of the park lock gear and controls the locking pawl to engage directly, eliminating the need for a dedicated angular position sensor for the electric machine, and providing dual functionality for detecting rotational speed and proper engagement of the locking pawl with the park lock gear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the park lock gear is not pre-positioned to a matching rotational position before engaging the locking pawl, then the structure remains simple without additional sensors, but the vehicle may move slightly during engagement causing reliability issues
Solution Approach 1:
The inductive angular position sensor is designed to serve multiple functions: detecting the rotational position of the park lock gear, determining when the locking pawl is properly engaged, and providing feedback for controlling the electric machine. This multi-functionality eliminates the need for separate dedicated sensors for each function, resolving the contradiction between reliability and device complexity.
Solution Approach 2:
The system uses the inductive angular position sensor to detect the current rotational position of the park lock gear before engagement, and the electronic control unit calculates the required rotational position in advance. The electric machine then pre-positions the park lock gear to a matching rotational position before the locking pawl engagement occurs, preventing vehicle movement during engagement and ensuring reliable locking.
2Manufacturing precision
If a dedicated angular position sensor is installed for the electric machine, then precise control of gear positioning is achieved, but the cost and device complexity increase
Solution Approach 1:
The inductive angular position sensor mounted on the park lock gear serves multiple purposes: it provides positional feedback for precise gear positioning control, detects when the locking pawl is properly engaged, and enables the electronic control unit to calculate the required rotational position. This eliminates the need for a separate dedicated angular position sensor on the electric machine, reducing both cost and device complexity while maintaining manufacturing precision.
3Reliability
If the locking pawl engagement is not monitored, then the system remains simpler, but safety and reliability are compromised
Solution Approach 1:
The inductive angular position sensor's output signal is used not only for positioning control but also for monitoring locking pawl engagement. The electronic control unit detects whether the locking pawl is properly engaged by analyzing the sensor signal characteristics, eliminating the need for a separate engagement detection sensor and maintaining system reliability without excessive complexity.
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
This solution prevents vehicle movement during parking mode transitions and enhances safety by ensuring proper engagement of the locking pawl with the park lock gear, while also eliminating the need for a dedicated angular position sensor for the electric machine, resulting in a more reliable and cost-effective park lock assembly.
Implementation Method 1
an inductive angular position sensor that monitors the rotational position of the park lock gear
Data Source
AI summary
A park lock assembly for a vehicle transmission The park lock assembly comprises a toothed park lock gear (20) and a moveable locking pawl (21) that is moveable between an engaged state, in which the locking pawl (21) is in locking engagement with the park lock gear (20), and a disengaged state, in which the park lock gear (20) is freely rotatable relative to the locking pawl (21). The park lock assembly further comprises an inductive angular position sensor (22) located on an axial side of the park lock gear (20) and configured for detecting angular position of the park lock gear (20).