Parking Lock Re-Fitting Mechanism to Reduce Actuator Load
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing parking lock devices experience stress and potential damage due to the continuous load on the parking rod and driving portion when the fitting operation is not completed, and the coil spring deteriorates, increasing the load further.
Innovation Solution
Incorporating a re-fitting part, such as a parking pawl spring, that generates a re-fitting action using accumulated energy, allowing the fitting portion to perform re-fitting operations independently, reducing the stress on the driving portion and enabling efficient energy generation for re-fitting without relying on the engaging portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the parking rod includes a coil spring to enable re-fitting operation, then the parking pawl can be refitted into the parking gear, but stress continuously acts on the parking rod and driving portion during the period when fitting operation is not completed
Solution Approach 1:
The patent divides the re-fitting function into two separate components: the coil spring in the parking rod provides initial urging force, while a dedicated pawl spring mounted on the parking pawl provides the primary re-fitting force. This segmentation allows the driving portion to be relieved from continuous stress while maintaining reliable re-fitting capability.
Solution Approach 2:
The pawl spring acts as an intermediary element that directly urges the parking pawl toward the parking gear without requiring continuous engagement with the driving portion. This mediator transfers the re-fitting function away from the driving portion, reducing the load on actuators and other driving components during periods when fitting is not completed.
2Reliability
If the coil spring is used for re-fitting operation, then the parking pawl can be moved toward the parking gear, but the load applied to the parking rod and driving portion increases when the coil spring deteriorates
Solution Approach 1:
The patent segments the spring-based urging function between two independent springs: the coil spring in the parking rod and the pawl spring on the parking pawl. This segmentation ensures that if one spring deteriorates, the other can still provide re-fitting capability, and the driving portion is protected from excessive loads regardless of spring condition.
Solution Approach 2:
The pawl spring is pre-installed on the parking pawl as a backup cushioning element that prevents excessive loads on the driving portion even if the coil spring deteriorates. This beforehand cushioning protects the structural integrity of the driving portion by providing an alternative force source that does not transmit excessive stress to the actuator.
3Productivity
If the parking rod performs re-fitting operation through coil spring expansion, then the parking pawl can be refitted, but stress relief is delayed and load on driving portion persists
Solution Approach 1:
The patent extracts the primary re-fitting function from the parking rod's coil spring and relocates it to a dedicated pawl spring on the parking pawl. This extraction allows the coil spring to serve only its original function while the pawl spring handles re-fitting, thereby relieving stress from the parking rod and driving portion while maintaining rapid re-fitting capability.
Solution Approach 2:
The pawl spring is directly mounted on the parking pawl, enabling the parking pawl to perform self-service re-fitting operations without requiring continuous engagement with the parking rod or driving portion. This self-service mechanism allows the parking pawl to autonomously refit into the parking gear using its own mounted spring, reducing stress on the parking rod and eliminating the need for the driving portion to remain engaged during re-fitting.
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 stress transmission to the driving portion, reduces load on the actuator, and allows for independent re-fitting of the parking pawl, enhancing the reliability and reducing power consumption by utilizing stored energy for re-fitting operations.
Implementation Method 1
The coil spring urges the cam member toward one end of the parking rod
Implementation Method 2
the contracted coil spring expands to cause the cam member to slide against the parking pawl
Implementation Method 3
a parking pawl spring that generates a re-fitting action based on stress generated during a period in which a fitting operation for fitting the parking pawl into the parking gear is not completed
Data Source
AI summary
The parking lock device includes: a parking gear; a fitting portion that is fittable into the parking gear; an engaging portion that engages with the fitting portion; and a driving portion that drives the engaging portion to move the fitting portion in a release direction with respect to the parking gear, the fitting portion including a re-fitting part that generates a re-fitting action based on stress generated during a period in which a fitting operation for fitting the fitting portion into the parking gear is not completed.