Sanitary Washing Device Pulsating Water Drop Control

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Solution Overview

Problem

Existing sanitary washing devices face challenges in achieving compatibility between the 'feeling of stimulation' and 'feeling of volume' while using a small amount of water, with previous techniques either compromising on one aspect for the other or increasing device size and cost.

Innovation Solution

The sanitary washing device alternately discharges 'first water drops' with a large cross-sectional area and slow velocity and 'second water drops' with a small cross-sectional area and fast velocity, ensuring each impinges on the body at different times, using a pressurizer to control pressure variations and reduce waste water, thus enhancing both washing sensations with reduced water usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the discharged water velocity is decreased to form large water drops, then the feeling of volume is improved, but the feeling of stimulation decreases

Engineering Contradiction:
Improvewater drop sizeVSAvoiddischarged water velocity
Core Design Contradiction:
Quantity of substanceVSSpeed

Solution Approach 1:

The patent applies periodic action by alternately generating two types of water drops in a pulsating manner. The pressure generating section creates a pulsating flow that periodically alternates between conditions favoring large drop formation and conditions favoring high velocity discharge, thereby providing both feelings of volume and stimulation in sequence.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent employs dynamics by making the water discharge characteristics changeable over time. The pressure generating section dynamically adjusts the discharge conditions between two states: one state produces large cross-sectional area drops for volume feeling, and the other state produces high velocity drops for stimulation feeling, allowing the system to adapt to different washing needs.

Inventive Principle:
Principle #15Dynamics

2Speed

If the discharged water velocity is accelerated to enhance the feeling of stimulation, then the feeling of stimulation is improved, but the previous discharged water cannot overtake the subsequent discharged water, failing to form a large water drop

Engineering Contradiction:
Improvedischarged water velocityVSAvoidwater drop size
Core Design Contradiction:
SpeedVSQuantity of substance

Solution Approach 1:

The patent resolves this contradiction by using periodic action to alternate between high velocity discharge (for stimulation) and low velocity discharge with overtaking (for volume). The pulsating flow creates distinct phases where each type of water drop is generated at different time intervals, eliminating the need to compromise either feeling.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically switches between two discharge modes: a first mode with high velocity for stimulation feeling, and a second mode with lower velocity that allows subsequent water to overtake and form large drops for volume feeling. This dynamic switching is controlled by the pressure generating section's pulsating operation.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If conventional techniques are used to achieve both feelings of volume and stimulation, then the washing feeling is improved, but the device size and cost increase

Engineering Contradiction:
Improvewashing feelingVSAvoiddevice size and cost
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies universality by making the pressure generating section perform multiple functions: it generates pulsating flow, controls water discharge velocity, and creates both types of water drops (large and fast) using a single integrated mechanism. This eliminates the need for separate devices or complex multi-component systems.

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

Solution Approach 2:

The patent uses parameter changes by varying the pressure conditions in the pulsating flow to control water discharge characteristics. By changing pressure parameters over time, the system achieves different water drop characteristics (size and velocity) without requiring physical changes to the device structure, thereby maintaining compact size and low cost.

Inventive Principle:
Principle #35Parameter changes

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 configuration provides a comfortable washing experience with both strong stimulation and sufficient volume, while significantly reducing water consumption and maintaining a compact, cost-effective device design.

Implementation Method 1

a pressure generating section for causing a pulsating transition in which a pressure higher than the water discharge pressure obtained from the supply water source is intermittently generated

Methodology Applied
Scientific EffectPulsating transition:

Implementation Method 2

wash water discharged from the water discharge port is pressurized so that the amount of overtaking by which the wash water discharged later overtakes the wash water discharged earlier is larger

Methodology Applied
Scientific EffectPressurization: Pressurisation

Data Source

PatentEP2397614B1Hygiene cleaning device
Publication Date: 2016.09.07 TOTO LTD
  • EP2397614B1 patent drawingFigure 1~2
  • EP2397614B1 patent drawingFigure 3~4B
  • EP2397614B1 patent drawingFigure 5~6

AI summary

A sanitary washing device according to the invention is a sanitary washing device discharging supplied wash water toward a human body, including: a washing nozzle including a water discharge port configured to discharge the wash water toward the human body; and a pressurizing device configured to pressurize the wash water and discharge the wash water from the water discharge port, the sanitary washing device being configured to perform a first water discharge process having a first time span and a second water discharge process having a second time span, in the first water discharge process, the pressurizing device making pressure of wash water discharged later in the first time span higher than pressure of wash water discharged at beginning of the first water discharge process so that the wash water discharged later in the first time span overtakes and unites with the wash water discharged at beginning of the first water discharge process to form a first water drop at a predetermined position from the water discharge port, in the second water discharge process, the pressurizing device making pressure of wash water discharged later in the second time span higher than pressure of wash water discharged at beginning of the second water discharge process so that the wash water discharged later in the second time span overtakes and unites with the wash water discharged at beginning of the second water discharge process to form a second water drop at a predetermined position from the water discharge port, the pressurizing device making difference between pressure changes of wash water in the first water discharge process and pressure changes of wash water in the second water discharge process so that the first water drop is larger than the second water drop, the pressurizing device making maximum pressure of the wash water in the second water discharge process higher than maximum pressure of the wash water in the first water discharge process so that the second water drop is faster than the first water drop, and a water discharged by the first water discharge process and a water discharged by the second water discharge process being alternately discharged from the water discharge port. Compatibility between the "feeling of stimulation" and the "feeling of volume" with a small amount of water used can be established and a comfortable washing feeling at high level can be provided.