Vehicle Seat Recliner Locking Gear Anti-Deformation Design
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Solution Overview
Problem
Conventional vehicle seat recliners experience issues with gap formation and abrasion between locking gears and guide blocks, leading to unintended seat back movement and potential deformation under external forces, compromising the locked state and durability.
Innovation Solution
The recliner design incorporates a gear rim with internal teeth, a guide plate with spaced guide blocks, a cam with support protrusions, and elastic members to maintain close contact and distribute forces, preventing clearance and deformation, and enhancing assemblability and torque consistency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If locking gears slide along guide blocks to enable movement, then the recliner can adjust seat back angle, but gaps and abrasion occur between locking gears and guide blocks leading to unintended movement
Solution Approach 1:
The locking gear is divided into two functional parts: a sliding portion that contacts the guide block for movement, and a locking portion with gear teeth that engages with the gear rim for secure positioning. This segmentation allows the sliding portion to wear while the locking portion maintains reliability through positive gear engagement.
Solution Approach 2:
The cam mechanism acts as an intermediary that controls the engagement between the locking gear and gear rim. By rotating the cam, the locking gear is pushed against the gear rim to ensure positive engagement, while the guide block provides the sliding path. This intermediary control separates the movement function from the locking function.
2Adaptability or versatility
If locking gears repeatedly slide along guide blocks, then angle adjustment is enabled, but friction causes abrasion and gap formation reducing durability
Solution Approach 1:
The locking gear is segmented into a sliding portion for contact with the guide block and a locking portion with external gear teeth. This allows the sliding portion to handle repeated movements while the locking portion with gear teeth provides durable, gap-free engagement with the gear rim, preventing wear from affecting the locking function.
Solution Approach 2:
The cam mechanism preliminarily pushes the locking gear against the gear rim before the locking teeth fully engage. This preliminary action ensures that the locking teeth are already in contact and bearing load before the sliding portion completes its movement, preventing gap formation and reducing wear on the sliding surfaces.
3Force
If external force is applied to the recliner, then force is focused on one guide block, but this causes deformation of locking gears or guide blocks
Solution Approach 1:
The locking gear combines sliding contact with the guide block and gear tooth engagement with the gear rim into a single integrated component. This merging allows external forces to be distributed between the guide block (for sliding movement) and the gear rim (for load-bearing engagement), preventing force concentration on a single guide block.
Solution Approach 2:
The locking gear serves multiple functions simultaneously: it slides along the guide block for position adjustment, engages with the gear rim for secure locking, and distributes external forces between these two contact points. This multi-functionality prevents structural deformation by providing multiple load paths.
4Device complexity
If only small areas of the cam contact locking gears in locked state, then the cam structure remains simple, but stress concentration causes easy deformation or damage
Solution Approach 1:
The cam is designed with a localized contact surface that specifically engages the locking gear at the optimal point. This localized quality concentrates the pushing force on a small, well-defined area of the locking gear, ensuring effective engagement with the gear rim while maintaining cam structure simplicity. The locking gear's geometry is similarly optimized at the contact point to distribute stress.
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
This design ensures reliable locking, prevents unintended seat back movement, disperses external forces to prevent deformation, and reduces production costs by enhancing durability and strength while minimizing material thickness.
Implementation Method 1
a pair of elastic members fastened to diametrically opposed portions of an inner surface of the guide plate, each of the elastic members elastically supporting on a first end thereof a first end of a corresponding support protrusion of the cam
Data Source
AI summary
The present invention provides a recliner for vehicle seats. The recliner includes a gear rim, a guide plate, a lever rotating shaft, a cam, elastic members, a main control disk, locking gears and locking gear support members. The gear rim has internal gear teeth. The guide plate is coupled to the gear rim and has guide blocks thereon. The lever rotating shaft is inserted through the gear rim and the guide plate. The cam has support protrusions on both ends thereof. The elastic members are provided on the inner surface of the guide plate, and each elastic member elastically supports a first end of the corresponding support protrusion. The main control disk is coupled to the cam. Inner and outer guide holes are formed through the main control disk. The locking gears are slidably provided between the facing guide blocks, and each locking gear has a support depression. The support depression has a concave curved surface and a convex curved surface. External gear teeth are formed in each locking gear. Each locking gear support member has a first contact surface which is in close contact with the concave curved surface of the support depression, a second contact surface which is in close contact with the corresponding guide block, and an inner surface which is supported on both ends thereof by the cam.