Manual Gearshift Lock With Direct Pawl Engagement for Compact Parking
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Solution Overview
Problem
Existing gearshift lock systems for motorcycles with automatic gearboxes require multiple components and a separate lever mechanism, which is not suitable for compact designs and often leads to the impairment of the service brake system when used for parking, and there is a risk of forgetting to release the parking brake.
Innovation Solution
A gearshift lock system that uses a direct torque-proof connection between an engagement element and the pawl, which is preloaded by a spring element, eliminating the need for a lever mechanism and allowing the pawl to be held in a freewheeling position by interacting with the gearshift cylinder, and can be released into a locked position without the risk of the pawl tooth hitting the pawl wheel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a lever mechanism with multiple levers is used to actuate the pawl, then the pawl wheel can be positioned far from the cam disc, but the device becomes complex and takes up a lot of space
Solution Approach 1:
The invention extracts and eliminates the complex lever mechanism from the system. Instead of using multiple levers to transmit motion from the cam disc to the pawl wheel, the patent uses a direct actuation mechanism where the cam disc directly engages with the pawl through a simplified lever arm, removing unnecessary intermediate components and reducing spatial requirements.
Solution Approach 2:
The cam disc serves multiple functions: it controls both the shifting operation and the locking operation. By integrating these functions into a single component rather than requiring separate mechanisms, the patent reduces the overall device complexity and space occupation while maintaining the required functionality.
2Reliability
If a locking cam is used to press the pawl into the locked position, then the pawl can be secured, but additional spring components are required to prevent damage from tooth impact
Solution Approach 1:
The invention applies beforehand cushioning by designing the engagement geometry between the cam disc and pawl such that the pawl is gradually guided into the locked position rather than being abruptly forced. This controlled engagement prevents impact damage between teeth, eliminating the need for additional protective spring components while maintaining reliable locking.
Solution Approach 2:
The patent merges the locking function and the cushioning/protection function into a single integrated mechanism. The cam disc's engagement profile simultaneously provides the locking action and the controlled, impact-free engagement, eliminating the need for separate protective components.
3Reliability
If the pawl is pretensioned by a spring element in the direction of the locked position, then the locking engagement is improved, but the risk of pawl tooth hitting pawl wheel tooth increases
Solution Approach 1:
The invention applies beforehand cushioning by designing the cam disc engagement profile to gradually guide the pretensioned pawl into the locked position. This controlled engagement sequence allows the spring pretension to improve locking reliability while preventing abrupt tooth-to-tooth impact through progressive engagement.
Solution Approach 2:
The patent changes the engagement parameters by using a cam disc with a specifically designed profile that controls the timing and manner of pawl engagement. This parameter change allows the system to maintain high locking engagement force while avoiding harmful tooth impact through controlled geometric engagement.
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 system achieves a compact design with fewer components, ensures the parking brake is not forgotten when starting the vehicle, and does not impair the service brake system, while providing reliable locking and unlocking functionality.
Implementation Method 1
The pawl is pretensioned by a spring element in the direction of the locked position
Data Source
AI summary
A gearshift lock for a gearbox includes a gearshift cylinder and a pawl wheel with a toothing. The gearshift lock includes a rotatably positioned pawl, and the pawl engages in the toothing of the pawl wheel in a locked position, and is disengaged from the pawl wheel in a freewheeling position. The pawl is pretensioned by a spring element in the direction of the locked position, and an engagement element is connected to the pawl. The engagement element holds the pawl in the freewheeling position by directly interacting with the gearshift cylinder against the effect of the spring element when the gearshift cylinder takes up a rotational position in a freewheeling rotational range, and the pawl can be released from the gearshift cylinder into a locked position by the engagement element when the gearshift cylinder takes up a rotational position in a locked rotational range.