Lifter Device Feed Pawl Phase Alignment
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Solution Overview
Problem
Existing lifter devices for automobile seats experience operation loss due to phase mismatch between feed pawls and feed gear, leading to inefficiency in transmitting operation force to the pinion gear, as the feed pawls do not mesh with the feed gear until both have matching phases, resulting in potential loss of one gear tooth's operation.
Innovation Solution
The implementation of a configuration where multiple feed pawls with different meshing phases are provided, allowing one to mesh with the feed gear first, thereby reducing operation loss by ensuring the feed gear is driven to rotate as soon as any feed pawl engages, eliminating the need for a separate operation force transmission delay mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single feed pawl is used to mesh with the feed gear, then the structure is simple, but operation loss occurs due to phase mismatch between the feed pawl and feed gear
Solution Approach 1:
The single feed pawl is segmented into multiple feed pawls (first feed pawl and second feed pawl) with different meshing phases. This segmentation allows at least one feed pawl to be in meshing engagement with the feed gear at any given time, eliminating the operation loss that occurs when a single pawl fails to mesh properly.
2Loss of energy
If multiple feed pawls with different meshing phases are provided, then operation loss is reduced, but the device complexity increases
Solution Approach 1:
Multiple feed pawls are merged into a single integrated structure where the first and second feed pawls are formed as integral parts of the same component. This merging approach reduces device complexity by eliminating the need for separate mounting mechanisms and control systems for each pawl, while still achieving the benefit of reduced operation loss through phase differentiation.
3Reliability
If the feed pawls are separated from the feed gear in neutral position, then the lock mechanism can function properly, but meshing delay occurs until phases match
Solution Approach 1:
The feed pawls are preliminarily positioned at different phases relative to the feed gear teeth before operation begins. This preliminary action ensures that when the operation handle is actuated, at least one feed pawl is already in the correct phase to immediately mesh with the feed gear, eliminating meshing delay while maintaining the separated state needed for lock mechanism function.
Data Source
AI summary
A lifter device includes a pinion gear and a rotation control device that is configured to control rotation of the pinion gear. The rotation control device includes a rotation shaft, a support member, a rotation driving mechanism, and a lock mechanism. The rotation drive mechanism includes a feed gear, and a plurality of feed pawls. The lock mechanism is configured to release locking of the rotation shaft until any one of the feed pawls meshes with the feed gear when an operation handle is operated. A plurality of the feed pawls are provided with respect to either operation direction on a seat lifting side or lowering side of the operation handle, and one of the feed pawls meshes with the feed gear when at least one of the others of the feed pawls does not mesh with the gear.