Vehicle Door Lock Layout Using Rotational Lever Latch
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Solution Overview
Problem
Existing door lock devices for vehicles face challenges in downsizing due to layout restrictions from the contact positions and operation ranges of drive and latch pins, making it difficult to integrate the drive and meshing units closely.
Innovation Solution
The door lock device incorporates a lever latch and pressing unit driven by a motor, with the lever latch positioned below a top cover and a pressing unit that rotates in the striker's approach direction, allowing for a separate and orthogonal layout of the meshing and drive units, reducing the vehicle's front-to-rear dimension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the drive pin and latch pin are positioned to ensure proper engagement and operation, then the reliability of the door lock is improved, but the device size increases and layout flexibility is reduced
Solution Approach 1:
The patent changes the operational dimension of the latch mechanism from linear (push-pull in approach direction) to rotational (about latch axial direction). The latch rotates between engaged and disengaged positions, allowing the drive and latch units to be positioned closer together in the vehicle front-to-rear direction while maintaining reliable engagement through the rotational motion path.
Solution Approach 2:
The door lock device is divided into functionally independent units: the drive unit with motor and sector gear, the meshing unit with latch and lever latch, and the ratchet unit. This segmentation allows each unit to be optimized independently and positioned to minimize overall device volume while ensuring proper engagement between components.
2Volume of moving object
If the drive unit and meshing unit are positioned close to each other for downsizing, then the device volume is reduced, but the layout restrictions from contact positions and operation ranges make integration difficult
Solution Approach 1:
The latch operates by rotation about an axial direction orthogonal to the striker approach direction, rather than moving linearly in the approach direction. This dimensional change allows the drive pin to engage with the latch at positions that minimize the front-to-rear dimension of the entire device, enabling closer integration of drive and meshing units.
Solution Approach 2:
The lever latch acts as an intermediary between the pressing unit (drive mechanism) and the main latch. The lever latch translates the pressing motion into rotational motion of the main latch, allowing the drive unit and meshing unit to be positioned closer together while maintaining proper force transmission and engagement geometry.
3Device complexity
If a conventional linear drive mechanism is used, then the structure is simple, but the device cannot be further downsized due to operation range restrictions
Solution Approach 1:
The latch mechanism uses rotational dynamics instead of linear translation. The latch rotates about a fixed axial position rather than translating linearly, which reduces the operation range required in the vehicle front-to-rear direction. This dynamic change from linear to rotational motion enables device downsizing while maintaining functional simplicity.
Solution Approach 2:
The patent changes the motion parameter from linear displacement to angular rotation. By defining the latch operation in terms of rotation angle rather than linear distance, the device can achieve the same functional range of motion with a smaller physical footprint in the critical front-to-rear dimension.
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 achieves further downsizing of the door lock device, improving vehicle layout properties and reducing the required power and weight of the motor, making it suitable for power back doors and other vehicle doors.
Implementation Method 1
a pressing unit that is driven by a motor and rotates about a drive shaft in the approach direction of the striker
Implementation Method 2
a latch that engages with a striker of a body of the vehicle, the latch being rotatable about a latch axial direction orthogonal to an approach direction of the striker
Implementation Method 3
the lever latch includes: a lever portion whose distal end protrudes radially outward from an outer peripheral edge of the latch when viewed in the latch axial direction, the distal end being pressed and driven by the pressing unit
Data Source
AI summary
A door lock device includes: a latch that engages with a striker of a body of the vehicle, the latch rotatable about a latch axial direction orthogonal to an approach direction of the striker; a top cover that supports a latch shaft serving as a rotation center of the latch on an upper side in the latch axial direction; a lever latch integrally provided with the latch; and a pressing unit that is driven by a motor and rotates about a drive shaft in the approach direction of the striker. Further, the lever latch is positioned on a lower side with respect to the top cover in the latch axial direction, and the pressing unit presses and drives the lever latch on a lower side with respect to the top cover in the latch axial direction.