Sensor Element Cover with Inclined Tip Surface for Water Drainage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sensor devices in exhaust gas purification systems face challenges in preventing water condensation and subsequent water cracking, especially when the engine idles, leading to reduced detection performance and reliability due to inadequate water resistance and gas flow velocity.
Innovation Solution
A sensor device with a double-cover configuration, featuring an inner and outer cover with strategically positioned gas flow holes and an inclined surface, which promotes gas flow velocity and effectively discharges water condensate, preventing it from reaching the sensor element and enhancing detection performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If water resistance is improved by covering the sensor element, then detection performance deteriorates due to insufficient gas flow velocity
Solution Approach 1:
The element cover is divided into inner cover and outer cover with multiple holes distributed across different surfaces (side holes in outer cover, tip surface holes in both covers). This segmentation allows gas to flow through multiple pathways, maintaining detection performance while providing water resistance protection.
Solution Approach 2:
Different regions of the element cover have different hole configurations tailored to local requirements: outer side holes for gas intake, inner side holes for sensor access, and tip surface holes for water drainage. This local differentiation optimizes both water resistance and detection performance in specific areas.
2Reliability
If water condensation is prevented by increasing gas flow velocity, then structural complexity increases
Solution Approach 1:
The solution transitions from a single-cover design to a dual-cover configuration with holes distributed across multiple dimensions (side surfaces and tip surfaces). This dimensional expansion enables effective water drainage and gas flow without requiring complex internal structures within a single cover.
Solution Approach 2:
The inner cover is nested within the outer cover, creating a layered structure where each cover serves specific functions. The inner cover protects the sensor while the outer cover manages gas flow and water drainage, achieving complex functionality through nested simplicity.
3Ease of manufacture
If a single cover structure is used, then manufacturing is simpler, but water cracking occurs due to inadequate water discharge
Solution Approach 1:
The element cover is segmented into inner and outer covers with distinct drainage functions. The inner cover provides primary protection while the outer cover with tip surface holes enables effective water discharge, preventing water cracking without excessive manufacturing complexity.
Solution Approach 2:
The outer cover acts as an intermediary between the environment and the sensor element, managing water discharge through its tip surface holes. This intermediary structure protects the sensor from water cracking while maintaining manufacturing feasibility.
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 configuration improves gas flow velocity to the detection unit, enhances detection performance, and suppresses water cracking, resulting in a more reliable and efficient sensor device.
Implementation Method 1
an inclined surface connects the central portion to the outer tip surface holes
Implementation Method 2
a plurality of outer side holes, through which the gas under measurement circulates, are provided in a side surface of the outer cover
Data Source
AI summary
A sensor device includes a housing that has a sensor element inserted therein and holds the sensor element such that a detection unit is positioned at the tip end thereof in the axial direction, and an element cover disposed coaxially with the tip end. A tip surface of the outer cover has a plurality of outer tip surface holes provided outward from positions opposing the outer periphery of an inner tip surface hole. The tip surface of the outer cover includes a central portion which protrudes towards the inner tip surface hole, an outer peripheral portion in which the outer tip surface holes are formed and which is positioned farther toward the tip end than is the central portion, and an inclined surface connects the central portion to the outer tip surface holes.