Washing Nozzle Flow Path Layout to Prevent Toilet Nozzle Dripping

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Solution Overview

Problem

Sanitary washing devices with nozzles that advance and retreat in toilets often experience water dripping from the water discharge port, leading to potential messes and inefficiencies.

Innovation Solution

The sanitary washing device positions the water discharge port higher than the inlet when the nozzle is in the stored state, incorporates an upwardly convex flow channel design to collect excess water, and includes a body wash flow channel to prevent dripping, with differentiated curvatures in water supply and body wash flow channels to disperse load on the drive motor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the nozzle is positioned in the stored state with the water discharge port at a lower position, then water can be discharged effectively during washing, but water drips from the water discharge port when stored

Engineering Contradiction:
Improvewashing performanceVSAvoidwater dripping
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent inverts the conventional positioning logic by making the water discharge port positioned higher than the inlet of the flow channel switch valve in the stored state. This inversion prevents water dripping during storage while maintaining effective washing performance through the upwardly convex flow channel design that collects and redirects water.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent employs an upwardly convex flow channel design where the flow channel includes a top portion that curves upward. This curvature creates a water collection area at the top that prevents water from reaching the water discharge port during storage, while still allowing effective water flow during washing operations.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Object-generated harmful factors

If the flow channel is designed with upwardly convex shape to collect water, then water dripping is suppressed, but the device structure becomes more complex

Engineering Contradiction:
Improvewater drippingVSAvoidflow channel structure
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the water collection function with the existing flow channel structure by designing the flow channel with an upwardly convex shape that naturally collects water. This integration eliminates the need for separate water collection components while achieving the dripping prevention objective.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The upwardly convex flow channel serves multiple functions: it guides water flow during washing operations and simultaneously collects excess water to prevent dripping during storage. This multi-functionality reduces the need for additional components and simplifies the overall device structure.

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

3Object-generated harmful factors

If the water discharge port is positioned higher than the inlet, then water dripping is prevented, but water discharge effectiveness during washing may be reduced

Engineering Contradiction:
Improvewater drippingVSAvoidwater discharge efficiency
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The patent employs dynamic positioning where the relative positions of the water discharge port and inlet change based on the nozzle state. During storage, the water discharge port is higher to prevent dripping; during washing, the nozzle advances to position the water discharge port lower for effective water discharge. The flow channel switch valve dynamically switches between these configurations.

Inventive Principle:
Principle #15Dynamics

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 design effectively suppresses water dripping from the nozzle, enhances washing performance, and reduces peak load on the drive motor, ensuring efficient and hygienic operation.

Implementation Method 1

the water discharge port is positioned higher than an inlet of the flow channel switch valve when the washing nozzle is in a stored state

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP4682321A1Sanitary washing device
Publication Date: 2026.01.21 TOTO LTD
  • EP4682321A1 patent drawingFigure 1
  • EP4682321A1 patent drawingFigure 2
  • EP4682321A1 patent drawingFigure 3

AI summary

A sanitary washing device includes a casing and a nozzle unit configured to advance and retreat between the casing and a toilet. The nozzle unit includes a washing nozzle and a flow channel switch valve. The washing nozzle includes a water discharge port configured to discharge water toward a human body private part, and a flow channel configured to supply water to the water discharge port. The flow channel switch valve is configured to switch the flow channel between flow-enabled and shutoff. The water discharge port is positioned higher than an inlet of the flow channel switch valve when the washing nozzle is stored in a stored state.