Shift Lever Neutral Range Lock Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional automatic transmission vehicles allow direct shifting from the drive (D) range to the park (P) range even when the vehicle is not stopped, potentially damaging the parking mechanism due to driver error.
Innovation Solution
A shift lever mechanism with a neutral (N) range shift lock that includes a lever housing, an engaging lever with stop portions for D, N, and P ranges, and a latching mechanism to prevent direct rotation from the D range to the P range, using a solenoid and movable pin to ensure proper shifting only when the vehicle is stopped.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If direct shifting from D range to P range is allowed, then ease of operation is improved, but reliability deteriorates due to potential damage to parking mechanism
Solution Approach 1:
The patent introduces an intermediary latching mechanism with a stop pin that physically blocks direct shifting from D to P range. The stop pin acts as a mediator between the shift lever and the parking mechanism, preventing harmful direct engagement while allowing controlled shifting through the neutral range.
Solution Approach 2:
The patent segments the shifting path by introducing intermediate stop grooves (first stop groove for D-N transition, second stop groove for N-P transition) that divide the direct D-P shift path into two separate stages requiring passage through the neutral range, thereby preventing direct engagement of the parking mechanism.
2Reliability
If latching mechanism with stop pin is introduced, then parking mechanism safety is improved, but device complexity increases
Solution Approach 1:
The latching mechanism with the stop pin serves multiple functions: it blocks direct D-to-P shifting to protect the parking mechanism, allows normal D-to-N and N-to-P shifting when engaged, and can be controlled to enable/disable the restriction. This multi-functionality justifies the added complexity by providing both protection and operational flexibility.
Solution Approach 2:
The latching mechanism automatically engages and disengages based on the shift lever position and control signals, without requiring separate control systems. The stop pin self-actuates to block or allow shifting paths based on the engaging lever's position, reducing the need for additional complex control mechanisms.
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
Prevents damage to the parking mechanism by confining the shift lever rotation to the N range until the vehicle is stopped, allowing safe shifting to the P range, thus preventing erroneous direct shifts from the D range to the P range.
Implementation Method 1
The latching mechanism may be a solenoid provided with a stop pin configured to be pulled out in a direction toward the engaging lever or pulled in an opposite direction
Data Source
AI summary
A shift lever mechanism has a neutral (N) range shift lock, the shift lever mechanism configured such that when shifting from a drive (D) range to a park (P) range, rotation of a shift lever is confined to the N range, and then, when a shift condition to the P range is satisfied, the shift lever is rotated to allow shifting to the P range, thereby preventing damage to a parking mechanism due to driver error when shifting to the P range.