Tire Sensor Casing Through Hole Design for Liquid Blockage Prevention

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Solution Overview

Problem

Existing tire monitoring systems face difficulties in preventing puncture repairing liquids from blocking ventilation holes in the tire hollow region, which can interfere with air pressure measurement during tire repairs.

Innovation Solution

A transmitting device with a casing featuring a through hole that extends orthogonally to the sensor detection face, where the outer aperture area is 0.8 mm² or less, and the volume between aperture parts is set to optimize the surface area to volume ratio between 3.0 to 30.0 mm⁻¹, reducing the likelihood of blockage by puncture repairing liquids.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the aperture part is provided at the apex of a protruding part with height 1 mm or greater, then the transmitting device can be protected from direct contact with puncture repairing liquid, but the puncture repairing liquid still blocks the through hole and interferes with air pressure measurement

Engineering Contradiction:
Improveprotection from puncture repairing liquidVSAvoidair pressure measurement
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The through hole is oriented orthogonally to the sensor detection face, creating a three-dimensional pathway that allows the sensor to detect air pressure through the casing wall without the aperture being directly exposed to puncture repairing liquid. This spatial reorientation resolves the contradiction by separating the protection function from the measurement function in different dimensional directions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The aperture area is specifically controlled to be 0.8 mm² or less, creating a localized small opening that minimizes the risk of blockage by puncture repairing liquid while still allowing sufficient air pressure transmission. This local optimization of aperture size resolves the contradiction between protection and measurement precision.

Inventive Principle:
Principle #3Local quality

2Reliability

If the aperture area is made small to prevent blockage, then the through hole is less likely to be blocked by puncture repairing liquid, but the air pressure measurement capability may be compromised

Engineering Contradiction:
Improveresistance to blockageVSAvoidair pressure detection accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The aperture area is optimized to 0.8 mm² or less, and the surface area to volume ratio of the through hole is controlled within 3.0 to 30.0 mm⁻¹. These parameter optimizations ensure that the small aperture resists blockage by puncture repairing liquid while maintaining sufficient air pressure transmission capability for accurate measurement.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The through hole acts as an intermediary pathway that transmits air pressure from the tire hollow region to the sensor without requiring a large direct aperture. The orthogonal orientation and controlled dimensions of the through hole mediate between the need for small aperture (to prevent blockage) and adequate measurement capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the through hole extends orthogonally to the sensor detection face with small aperture area, then blockage by puncture repairing liquid is prevented, but the device complexity increases

Engineering Contradiction:
Improveprevention of through hole blockageVSAvoidcasing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The through hole is segmented into distinct aperture parts (outer aperture and inner aperture) with different functional requirements. The outer aperture on the tire hollow region side has area 0.8 mm² or less for blockage prevention, while the inner aperture adjacent to the sensor can be larger for measurement. This segmentation resolves the contradiction by distributing different functions to different parts of the same structure.

Inventive Principle:
Principle #1Segmentation

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 design effectively prevents puncture repairing liquids from blocking the ventilation holes, ensuring accurate air pressure measurement and facilitating easy rim assembly while minimizing damage to the device.

Implementation Method 1

a sensor which detects, as tire information, a state of a gas which is filled in a hollow region of a tire

Methodology Applied
Scientific EffectPressure detection:

Implementation Method 2

a transmitter which wirelessly transmits the detected tire information

Methodology Applied
Scientific EffectWireless transmission: Electromagnetic Induction

Data Source

PatentEP2905152B1Transmission device and tire state monitoring system
Publication Date: 2018.01.10 THE YOKOHAMA RUBBER CO LTD
  • EP2905152B1 patent drawingFigure 1
  • EP2905152B1 patent drawingFigure 2
  • EP2905152B1 patent drawingFigure 3~4

AI summary

A transmitting device which is disposed in a tire hollow region, and which transmits tire information relating to the state of the tire, comprises: a sensor which detects, as tire information, a state of a gas which is filled in the hollow region of a tire which is surrounded by the tire and a rim; a transmitter which wirelessly transmits the tire information; and a casing which houses the sensor and the transmitter therewithin. The casing further comprises a through hole which passes through a wall of the casing, and which extends in an orthogonal direction to a sensor detection face of the sensor. The surface area of an outer side aperture part of the through hole is 0.8 mm2 or less, and the sensor detection face faces an inner side aperture part of the casing inner side of the through hole without obstructing with the space. A distance (h mm) which is the length of the through hole is 3 to 15 mm, and a ratio A/V of a surface area A mm2 of the lateral wall of the through hole to a volume V mm3 of the through hole is 3.0 to 30.0 mm-1.