Sliding Door Lock Mechanism with Planetary Gear Power Distribution

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Solution Overview

Problem

Existing sliding door opening-closing devices with locks face challenges in achieving a simple and compact construction while preventing premature locking and unintentional lock release, especially when the actuator loses driving force.

Innovation Solution

A sliding door opening-closing device with a lock mechanism utilizing a planetary gear mechanism to distribute power from a single actuator, where power is transmitted to the pinion for opening and closing operations and to a switching lever for locking and unlocking, ensuring the lock is engaged only at the full closing position and maintaining the lock even if the actuator loses power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a buffer body is used to distribute driving force for opening/closing operations and lock operation, then the construction can be simplified, but the entire construction becomes complicated and space is required for the movable stroke amount of the buffer body

Engineering Contradiction:
Improveconstruction simplicityVSAvoidspace for buffer body movement
Core Design Contradiction:
Device complexityVSVolume of moving object

Solution Approach 1:

The patent extracts the buffer body from the moving assembly and fixes it to the vehicle body, separating the buffering function from the moving components. This eliminates the need for movable stroke space while maintaining the driving force distribution function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a separate control lever mechanism that acts as an intermediary to control the lock operation independently from the buffer body's movement, allowing precise control without requiring the buffer body to move excessively.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the slide cam device is pushed to extend the buffer spring before full closing, then the lock mechanism is activated early, but the latch lock and hole portion positions are not aligned causing damage risk

Engineering Contradiction:
Improvelocking speedVSAvoidlocking accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent employs a control lever that is actuated only when the sliding door reaches the precise full closing position, providing feedback-based control that ensures the lock mechanism is activated at the correct moment when positions are aligned.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control lever is designed to remain in a neutral state until the door reaches the correct position, at which point it automatically transitions to activate the lock mechanism, ensuring preliminary positioning before locking action.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the buffer spring is set to be strong to prevent premature locking under load, then lock reliability improves, but force applied in lock release direction increases when actuator loses driving force

Engineering Contradiction:
Improvepremature locking preventionVSAvoidunintentional lock release force
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the locking control into two independent parts: the buffer spring for maintaining closing force and the control lever for activating lock/dump operations. This allows the buffer spring to be strong without causing unintentional lock release, as the control lever independently manages the locking state transition.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control lever serves as an intermediary between the buffer spring force and the lock mechanism, allowing the strong buffer spring to maintain door closure while the lever precisely controls when locking or dumping occurs, preventing unintentional lock release.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution provides a compact and simplified construction that prevents premature locking and ensures the sliding door remains locked reliably, even during actuator failure, by using a planetary gear mechanism to manage power distribution effectively.

Implementation Method 1

a planetary gear mechanism for inputting driving force of this actuator thereto

Methodology Applied
Scientific EffectGear mechanism: Gear

Data Source

PatentEP1721802B1Opening-closing device with lock
Publication Date: 2010.03.10 NABTESCO CORP
  • EP1721802B1 patent drawingFigure 1
  • EP1721802B1 patent drawingFigure 2
  • EP1721802B1 patent drawingFigure 3

AI summary

The invention provides a simple and compact construction in an opening-closing device with a lock for also performing a closing lock by power of an actuator for opening and closing a sliding door (11). Further, it is prevented that the lock is performed before reaching a full closing position and the lock is unintentionally released at a breaking time of the actuator. Therefore, the invention has an unillustrated actuator as an opening-closing driving source of sliding doors able to be reciprocated, a planetary gear mechanism (20) for inputting driving force of this accuator thereto, and a lock mechanism (30) able to lock the sliding doors in a full closing position. When the sliding doors are located in positions except for the full closing position, the power of the actuator is distributed to a pinion of a rack and pinion mechanism through the planetary gear mechanism, and operates the sliding doors. In contrast to this, when the sliding doors are located in the full closing position, the power of the actuator is distributed to a lock plate (33) for switching of locked state/lock releasing state of the lock mechanism. Further, when the sliding doors are located in the positions except for the full closing position, a movement of the lock plate is prevented. In contrast to this, when the sliding doors are located in the full closing position, the movement of the lock plate is allowed.