Powered Pawl Neutral Lock Mechanism for Vehicle Shifters
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Solution Overview
Problem
Existing neutral lock mechanisms in automatic transmission shifters are complex and costly, prone to breakdown, and require additional components like shift actuators and brake pedal depression for functionality.
Innovation Solution
A shifter system with a base structure, a shift lever, and a powered pawl member that engages a shift gate, utilizing a solenoid with a movable output member biased to an intermediate position, which shifts based on electrical current polarity to control the shift lever's movement between PARK, NEUTRAL, and DRIVE positions, and includes a sensor to determine the shift lever's position and a controller to actuate the pawl for locking the NEUTRAL position unless the brake pedal is depressed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional neutral lock mechanism is used, then the shift lever can be locked in the NEUTRAL position, but the device becomes complex and costly with more components prone to breakdown
Solution Approach 1:
The patent combines the neutral lock function with the existing PARK lock mechanism by using a single powered pawl that can engage with both the NEUTRAL position and PARK position on the shift gate. This eliminates the need for separate neutral lock components, reducing device complexity while maintaining reliability through the unified powered pawl design controlled by the controller based on brake pedal signals.
2Ease of operation
If additional components like shift actuators and brake pedal depression mechanisms are added for neutral lock functionality, then the neutral lock can function properly, but the cost increases and the device becomes more prone to breakdown
Solution Approach 1:
The powered pawl is designed as a multi-functional component that serves both the traditional PARK lock function and the NEUTRAL lock function. The single powered pawl can engage with different positions on the shift gate (PARK position and NEUTRAL position) based on controller actuation, eliminating the need for separate neutral lock actuators and reducing the overall number of components in the system.
3Device complexity
If a powered pawl with solenoid is used instead of traditional neutral lock, then the mechanism is simplified and cost is reduced, but the control complexity increases
Solution Approach 1:
The patent replaces traditional mechanical neutral lock mechanisms with an electronically controlled powered pawl system. The solenoid actuated powered pawl is controlled by an electronic controller that receives signals from the brake pedal sensor, substituting complex mechanical linkages with electronic control logic. This reduces mechanical complexity while the controller automation manages the increased control requirements through electronic signal processing rather than mechanical control elements.
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
The solution simplifies the neutral lock mechanism, reduces costs, and enhances reliability by using a solenoid and pawl system to control the shift lever's movement, ensuring the shift lever remains locked in the NEUTRAL position only when the brake pedal is depressed, thus preventing unintended movement.
Implementation Method 1
A solenoid has a movable output member operably connected to the pawl member, and the movable output member is biased towards an intermediate position. The output member shifts an opposite direction when the solenoid is energized with electrical current having opposite polarities.
Data Source
AI summary
A shifter for vehicles including a base structure and a shift lever that is movably mounted to the base structure. A shift gate controls movement of the shift lever between a plurality of control positions including at least PARK, NEUTRAL and DRIVE control positions. The shifter also includes a powered pawl having a pawl member configured to engage the shift gate. The pawl member defines a first position relative to the shift gate wherein the shift lever is locked in the NEUTRAL position. The pawl member also defines a second position relative to the shift gate wherein the shift lever is movable between the PARK, NEUTRAL and DRIVE positions. The pawl member further defines a third position relative to the shift gate wherein the pawl member locks the shift lever in the PARK position.