Open Tank Drainage Control for Sanitary Washing Device Leakage

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Solution Overview

Problem

Sanitary washing devices with reserve tanks often experience water leakage during cleaning or relocation, leading to potential breakdowns and delayed water supply due to residual water in the tank, and issues with backflow and garbage jamming in the water channel.

Innovation Solution

Incorporating an open tank in the water supply channel with a control device that performs drainage control based on sensors and switches to prevent water splashing, backflow, and garbage ejection, using the washing pump for drainage and overflow control, and integrating a heat exchanger with a backflow prevention mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a reserve tank is provided in the water channel to store water for quick supply, then water supply speed is improved, but water leakage and splashing occurs during cleaning or relocation

Engineering Contradiction:
Improvewater supply speedVSAvoidwater leakage prevention
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent extracts the harmful element (residual water) from the system by providing a drainage mechanism that removes water from the reserve tank when not in use. This allows the tank to maintain water for quick supply during operation while preventing leakage during cleaning or relocation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements dynamic control of the reserve tank by using a control device that activates drainage based on operational status. The system transitions between water-retention mode (during operation) and water-drainage mode (during cleaning/relocation), resolving the contradiction between maintaining water supply readiness and preventing leakage.

Inventive Principle:
Principle #15Dynamics

2Productivity

If water is stored in the open tank for quick discharge, then productivity is improved, but water decay occurs during prolonged storage

Engineering Contradiction:
Improvewater discharge speedVSAvoidwater quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements periodic drainage cycles where water is stored in the open tank during operation for quick discharge, then periodically drained when not in use. This cyclic operation maintains water quality by removing stored water before decay occurs while preserving the ability to quickly discharge water when needed.

Inventive Principle:
Principle #19Periodic action

3Reliability

If drainage control is performed immediately when human body sensor stops sensing, then water leakage is prevented, but water supply is delayed during temporary user absence

Engineering Contradiction:
Improveleakage preventionVSAvoidwater supply delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by implementing a timing mechanism that waits for a predetermined period before activating drainage. This allows the system to distinguish between temporary absence (user still needs water) and permanent absence (drainage safe to activate), preventing both leakage and unnecessary water supply delays.

Inventive Principle:
Principle #10Preliminary action

4Device complexity

If the washing pump is used for drainage control, then device complexity is reduced, but water level in heat exchanger may be affected

Engineering Contradiction:
Improvedrainage system complexityVSAvoidheat exchanger water level
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements multi-functionality by using the washing pump for both its primary function (supplying water to the nozzle) and secondary function (drainage control). This reduces device complexity by eliminating the need for a separate drainage pump while maintaining heat exchanger water level through proper control sequencing.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Prevents water leakage and breakdowns during cleaning or relocation, ensures quick water supply, maintains water level in the heat exchanger, and prevents garbage jamming by efficiently draining and overflowing water, thus enhancing usability and reducing maintenance.

Implementation Method 1

a heat exchanger configured to heat water supplied from the washing pump

Methodology Applied
Scientific EffectHeat exchanger: Heat Exchanger

Implementation Method 2

a washing pump configured to pump water from inside of the open tank to supply water to the water discharge nozzle

Methodology Applied
Scientific EffectPump: Pump

Data Source

PatentEP3680404B1Sanitary washing device
Publication Date: 2023.09.06 TOTO LTD
  • EP3680404B1 patent drawingFigure 1~2
  • EP3680404B1 patent drawingFigure 3~4
  • EP3680404B1 patent drawingFigure 5

AI summary

A sanitary washing device (100) includes: a water discharge nozzle (131) configured to discharge water at a human body part; a water supply channel configured to supply water to the water discharge nozzle; a solenoid valve (174) provided in the water supply channel and configured to control supply of water from a water supply source; an open tank provided in the water supply channel and including: a tank main body (180); an inflow port (181) configured to allow water to flow into the tank main body; an outflow port (182) configured to allow the water inside the tank main body to flow out to the water discharge nozzle; and an overflow port (183) provided so as to form an air gap between the overflow port and the inflow port and configured to drain excess water inside the tank main body to outside; a washing pump (191)provided in the water supply channel downstream of the open tank and configured to pump water out of the outflow port and supply the water downstream in the water supply channel; a casing housing the open tank; and a toilet seat and a toilet lid attached to the casing, wherein the sanitary washing device further comprising: a control device (160) configured to perform drainage control for draining water from inside the open tank with supply of water to the open tank being stopped.