Automotive Door Latch Pawl Spring Mounting for Dust Discharge
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Solution Overview
Problem
In automotive door latch devices, the pawl return spring is often arranged in a way that hinders dust discharge from the housing part, leading to potential deposition issues.
Innovation Solution
The pawl return spring is positioned below the pawl with a through hole allowing its end part to engage with the pawl, and assembled to a spring mounting part on the body, ensuring adequate space for dust discharge and enhanced assembly efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the pawl return spring is arranged below the pawl in the housing part to ensure mounting freedom, then the spring can be installed with adequate flexibility, but dust discharge is hindered and dust deposition occurs
Solution Approach 1:
The pawl return spring is repositioned from a vertical arrangement (below the pawl) to a lateral arrangement (on the side surface of the housing part). This dimensional change allows the spring to be mounted on the side surface while still engaging the pawl through a through-hole, thereby maintaining mounting freedom while eliminating interference with dust discharge pathways.
Solution Approach 2:
A through-hole is introduced as an intermediary structure in the housing part, allowing the pawl return spring to pass through and engage the pawl from the side. This mediator enables the spring to function while being positioned outside the main housing cavity, thus preventing dust deposition while maintaining spring functionality.
2Device complexity
If the pawl return spring is arranged on the axial extension line of the pawl, then the structure is simplified, but the mounting space is insufficient
Solution Approach 1:
Instead of arranging the spring along the axial extension line of the pawl (one-dimensional arrangement), the spring is positioned on the side surface of the housing part (utilizing lateral space). This dimensional transition from axial to lateral positioning provides sufficient mounting space while maintaining reasonable structural complexity.
Solution Approach 2:
The pawl return spring is nested through the through-hole of the housing part to engage the pawl. This nesting arrangement allows the spring to be positioned externally while still functioning internally, effectively utilizing space without requiring additional mounting volume.
3Reliability
If the housing part is closed to protect internal components, then component protection is improved, but dust discharge is blocked
Solution Approach 1:
The housing part is designed with selective openness: the bottom surface is opened to allow dust discharge, while the side surface contains the through-hole for spring engagement. This localized quality differentiation allows the housing to protect components where needed while maintaining dust discharge pathways where required.
Solution Approach 2:
The pawl return spring is extracted from the internal housing space and repositioned to engage through the side surface. This extraction removes the spring from the dust-prone internal environment while maintaining its functional engagement with the pawl, thus preventing dust accumulation while preserving component protection.
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 configuration allows for effective dust discharge and improved assembly efficiency, preventing dust deposition and ensuring smooth operation of the latch mechanism.
Implementation Method 1
a pawl return spring for biasing the pawl toward a return position thereof
Implementation Method 2
a latch return spring housed in the housing part of the body, for biasing the latch toward a return position thereof
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
Provided is an automotive door latch device, including: a latch pushed to rotate by a striker; a latch return spring for biasing the latch toward a return position thereof; a pawl engageable with the latch to inhibit the latch to pivot in a door opening direction (return position); and a pawl return spring for biasing the pawl toward a return position thereof. A housing part of a body, which houses the latch and the pawl, is opened downward at a position below the pawl on one side of the body. The pawl return spring is assembled to a spring mounting part formed on another side of the body at a position spaced downward from a rotational support part of the pawl, and includes a pawl-side end part that engages with the pawl through a through hole provided in the body. Thus, dust or the like entering the housing part of the body, which houses the latch and the pawl, can be discharged out of the body with higher efficiency.