Water Tank Float Switch Sealing to Prevent Sensor Short Circuits

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Solution Overview

Problem

Existing water tank assemblies in cooling fans pose a safety risk due to the risk of magnetic water level detection components short-circuiting when exposed to water, leading to potential electrical hazards.

Innovation Solution

A water tank assembly incorporating a proximity switch with a magnetic sensor and a waterproof seal, installed on an angled column with reinforcing ribs and a guiding structure, which prevents water contact and ensures safe operation by maintaining the magnetic sensor's integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a reed switch is used as a water level detection device, then the water level detection function is achieved, but the circuit board faces short-circuit risk when water leakage occurs

Engineering Contradiction:
Improvewater level detection reliabilityVSAvoidshort-circuit risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The magnetic sensor is extracted from the circuit board and integrated into a separate proximity switch assembly that is pre-installed on the water tank. This physical separation removes the vulnerable circuit board from the water environment while maintaining the water level detection function through the isolated magnetic sensor-proximity switch system.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

A magnetic field is introduced as an intermediary between the floater (moving with water level) and the detection system. The magnetic sensor detects the magnetic floater's position without direct water contact, using the magnetic field as a safe intermediary that transmits position information without requiring electrical components in the water path.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the magnetic sensor is exposed to water environment, then the water level detection is simplified, but the magnetic sensor contacts water causing safety hazards

Engineering Contradiction:
Improvedetection system complexityVSAvoidoperational safety
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The detection system is segmented into two distinct parts: a magnetic floater that moves with water level (exposed to water) and a magnetic sensor that remains protected (isolated from water). The proximity switch assembly acts as a protective barrier, segmenting the system so that only the magnetic field-transmitting floater contacts water while the electronic sensor remains safe.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The magnetic field serves as a copy or proxy for water level information. Instead of directly exposing the magnetic sensor to water, the system uses the magnetic floater as a proxy that carries water level position information through magnetic field changes, allowing the sensor to detect water level indirectly without water contact.

Inventive Principle:
Principle #26Copying

3Ease of operation

If the proximity switch is pre-installed on the water tank, then the installation convenience is improved, but the positioning precision and waterproofing reliability may be affected

Engineering Contradiction:
Improveinstallation convenienceVSAvoidpositioning precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The proximity switch is pre-installed on the water tank during manufacturing, with the installing column and limiting ribs pre-configured to ensure precise positioning. This preliminary action during assembly ensures that the proximity switch is correctly positioned relative to the magnetic sensor and floater, maintaining detection precision while simplifying final installation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A waterproof seal layer is applied to the proximity switch, creating a flexible protective barrier that maintains the magnetic sensor's isolation from water. This seal layer accommodates the pre-installed configuration while ensuring waterproofing reliability, allowing the proximity switch to be mounted on the water tank without compromising either positioning or waterproofing.

Inventive Principle:
Principle #30Flexible shells and thin films

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 solution effectively prevents water contact with the magnetic sensor, enhancing the safety of the water tank assembly and gas treatment device by avoiding electrical risks and ensuring reliable operation.

Implementation Method 1

the proximity switch includes a magnetic sensor and a seal waterproof layer provided outside the magnetic sensor, the magnetic sensor outputs different signals according to different positions of the floater with respect to the magnetic sensor

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Implementation Method 2

the seal waterproof layer is used for waterproofing of the magnetic sensor

Methodology Applied
Scientific EffectWaterproofing: Physical Containment

Implementation Method 3

the floater is able to go up or down with water in the water tank, the floater has magnetic properties

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentEP3816592B1Water tank assembly and gas treatment device
Publication Date: 2023.03.29 GREE ELECTRIC APPLIANCE INC OF ZHUHAI
  • EP3816592B1 patent drawingFigure 1
  • EP3816592B1 patent drawingFigure 2
  • EP3816592B1 patent drawingFigure 3

AI summary

The disclosure discloses a water tank assembly and a gas treatment device. The water tank assembly includes a water tank (1), a floater (2) and a proximity switch (3); the floater (2) is able to go up or down with water in the water tank (1), the floater (2) has magnetic properties, the proximity switch (3) includes a magnetron element (33) and a seal waterproof layer (34) provided outside the magnetron element (33), the magnetron element (33) outputs different signals according to different positions of the floater (2) with respect to the magnetron element (33), and the seal waterproof layer (34) is used for waterproofing of the magnetron element (33). The seal waterproof layer (34) of the proximity switch (3) is able to prevent the magnetron element (33) provided inside the proximity switch from contacting water, thereby avoiding a risk caused by the magnetron element (33) contacting water.