Vehicle Door Latch Layout With Recessed Capacitor Housing

Solution Overview

Problem

Existing door latch devices for vehicles are too large to be accommodated within the door without obstructing the trajectory of the window glass, especially when incorporating a power storage body as an emergency power supply means.

Innovation Solution

A door latch device with a partitioned case that separates the motor and mechanical mechanism from the power storage body, using a recessed accommodation space for the power storage body to minimize the device's size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a power storage body is added to the door latch device as an emergency power supply means, then the reliability is improved, but the volume of the door latch device increases

Engineering Contradiction:

Improveemergency power supply capabilityVSAvoiddoor latch device volume

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The power storage body is nested within the case by utilizing a recessed accommodation portion formed in the partition wall. This allows the power storage body to be placed in an otherwise empty space created by the recessed portion, effectively nesting it within the existing structure without increasing the overall device volume.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The partition wall is designed with a recessed accommodation portion that extends into the space allocated for other components. By creating this three-dimensional recessed space in the partition wall, the design utilizes unused volume within the existing footprint, allowing the power storage body to be accommodated without expanding the device in any external dimension.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Ease of operation

If the door latch device size is reduced to avoid obstructing window glass trajectory, then the ease of operation is improved, but the space for emergency power supply means is reduced

Engineering Contradiction:

Improvewindow glass trajectory clearanceVSAvoidspace for power storage body

Core Design Contradiction:

Ease of operationVSVolume of moving object

Solution Approach 1:

The power storage body is nested within the case by utilizing a recessed accommodation portion formed in the partition wall. This allows the power storage body to be placed in an otherwise empty space created by the recessed portion, effectively nesting it within the existing structure without increasing the overall device volume.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The partition wall is designed with a recessed accommodation portion that extends into the space allocated for other components. By creating this three-dimensional recessed space in the partition wall, the design utilizes unused volume within the existing footprint, allowing the power storage body to be accommodated without expanding the device in any external dimension.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS12553263B2Door latch device

Publication Date: 2026.02.17 MITSUI KINZOKU ACT

AI summary

A door latch device includes a motor, a mechanical mechanism, a door lock ECU, and a case. The door lock ECU includes a printed wiring board and a capacitor connected to the printed wiring board. The case includes a bottom plate, a first accommodation space for accommodating the motor and the mechanical mechanism on one side of the bottom plate, and a second accommodation space for accommodating the printed wiring board and the capacitor on the other side of the bottom plate. The bottom plate is provided with a capacitor accommodation portion recessed from the second accommodation space toward the first accommodation space and the capacitor is arranged in the capacitor accommodation portion.