Vehicle Door Power Close Mechanism with Cam-Actuated Neutral Switch

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Solution Overview

Problem

Conventional vehicle-door opening and closing devices require large capacity fuses and substrates due to high excess current detection, leading to increased costs and potential circuit damage from excessive load currents during motor operation.

Innovation Solution

Incorporating a gear-interlocked cam body with mountain-shaped cam faces and a neutral switch to detect the return of the drive gear to a neutral position, allowing the motor to reverse rotation based on switch signals, thereby avoiding excessive load currents and reducing circuit costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If load current detection is used to return drive gear to neutral position, then the drive gear can be returned after power unit actuation, but a fuse with large capacity and tough substrate are required due to high excess current, increasing cost

Engineering Contradiction:

Improvedrive gear return controlVSAvoidcircuit cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical current detection method with a cam body and switch mechanism. The cam body, driven by the drive gear, mechanically detects the neutral position and actuates a switch to signal the control unit, eliminating the need for high-current sensing circuits and large capacity fuses.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The cam body serves as an intermediary mechanical element that translates the position of the drive gear into a switch actuation signal. This intermediary mechanism allows indirect detection of the neutral position without requiring direct electrical measurement of high currents.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Use of energy by moving object

If voltage used in automobile is low, then motor operation is efficient, but detected excess current has quite high value requiring large capacity fuse and tough substrate

Engineering Contradiction:

Improvemotor efficiencyVSAvoidcircuit component specification

Core Design Contradiction:

Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

The patent eliminates the need for high-current electrical detection by using a mechanical cam body and switch system. The cam body physically interacts with the drive gear mechanism to detect neutral position, converting an electrical measurement problem into a mechanical position detection problem.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts the current detection function from the electrical circuit and relocates it to the mechanical domain through the cam body and switch mechanism, thereby removing the requirement for high-capacity fuses and tough substrates from the circuit design.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS10697210B2Vehicle-door opening and closing device

Publication Date: 2020.06.30 HI-LEX ACT CORP

AI summary

A vehicle-door opening and closing device includes: a latch unit configured to keep a vehicle door in a half latched state or a fully latched state; a power close mechanism configured to displace the vehicle door from the half latched state to the fully latched state; a power release mechanism configured to release the fully latched state to bring the vehicle door to an openable state; and a drive gear configured to be driven by a motor. The power release mechanism is configured to be actuated with a drive force of the drive gear. A return switch configured to be switched upon driving in a predetermined drive range sufficient to complete actuation of the power release mechanism is placed near the drive gear. The motor is configured to return the drive gear based on a signal from the return switch.