Parking Lock Mechanism With Low-Force Release Rotation
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Solution Overview
Problem
The existing parking locking mechanism in automatic transmissions is complex, leading to increased assembly difficulties and costs, and requires a large actuator to release the locking mechanism, especially when operating on inclined surfaces, which is not efficient for miniaturization.
Innovation Solution
A rotation locking device comprising a locking gear with engaging concave portions, a reverse input blocking clutch, and an engaging member that allows for easy configuration and reduces the force required to release the engagement by rotating the engaging member in the same direction as the applied force, enabling smooth switching between locked and unlocked states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional parking locking mechanism with detent plate, rod, and cam structure is used, then the locking function is achieved, but the device complexity increases and assembly becomes troublesome
Solution Approach 1:
The patent combines the detent plate, rod, and cam into a single integrated locking member that performs all locking functions. This merging of multiple components into one reduces device complexity while maintaining the locking reliability through the unified structure's engaging portion that interacts with the locking gear's concave portions.
Solution Approach 2:
The locking member serves multiple functions simultaneously: it engages with the locking gear to prevent rotation, provides the locking action through its engaging portion, and eliminates the need for separate detent and cam mechanisms. This multi-functionality reduces the overall number of components while achieving the same reliable locking effect.
2Reliability
If a conventional parking locking mechanism is used, then the locking function is achieved, but the assembly work becomes troublesome and cost increases
Solution Approach 1:
By merging the detent plate, rod, and cam into a single locking member, the patent reduces the number of parts that need to be assembled. This integration simplifies the assembly process and reduces manufacturing cost while maintaining the reliable locking function through the unified structure.
3Reliability
If a conventional parking locking mechanism is used, then the locking function is achieved, but a large actuator with large output is required to release the mechanism, which is disadvantageous for miniaturization
Solution Approach 1:
The patent extracts and eliminates the cam mechanism from the conventional design, retaining only the essential locking engagement function. This simplification reduces the force required to disengage the locking member from the locking gear, allowing for a smaller, more compact actuator that can still reliably release the parking lock.
4Ease of operation
If the engaging member is rotated opposite to the direction of applied force to release engagement, then the locking mechanism can be released, but a large force is required which is not efficient for miniaturization
Solution Approach 1:
Instead of rotating the engaging member opposite to the applied force direction, the patent designs the mechanism to rotate in the same direction as the applied force. This inversion of the conventional approach allows the force to directly assist the rotation, reducing the required force and enabling more efficient operation with smaller actuators.
Data Source
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AI summary
A structure of a rotation locking device that is easily configured and capable of keeping cost down is achieved. A rotation locking device 4 switches between a first mode where an engaging claw portion 14 engages with an engaging concave portion 9 by an output member 13 rotating an engaging member 8 due to an input member 12 being rotationally driven by an actuator 7, and rotation of a locking gear 5 supported by and fixed to an output shaft 3 of an automatic transmission 2 is restricted, and a second mode where engagement between the engaging claw portion 14 and the engaging concave portion 9 is released and rotation of the locking gear 5 is allowed.