Jet Nozzle Swirling Flow via Cross-Section Expansion

Solution Overview

Problem

Conventional jetted bathtubs with jet nozzles that produce straight or rotary jet flows often result in monotonous massage experiences due to complex structures that are prone to clogging and wear, failing to effectively stimulate areas like the back, hips, and legs, and require additional components for rotation, which complicates fabrication and maintenance.

Innovation Solution

A jetted bathtub with a simplified nozzle design that uses a channel cross-section shrinking section and abrupt expansion section to produce a swirling jet flow without the need for rotary components, allowing for cost-effective fabrication and reduced maintenance, while providing a broad, soft massage stimulus by ejecting water under the surface, effectively targeting the back, hips, and legs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a rotary mechanism is used to produce rotating jet flow, then the massage diversity is improved, but the device complexity and maintenance difficulty increase

Engineering Contradiction:

Improvemassage diversityVSAvoidnozzle structure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical rotary system with a fluid dynamic system. The swirling jet flow is generated by the interaction between the injected jet and the co-rotating water flow in the bathtub, eliminating the need for mechanical rotating components while achieving the same massage diversity effect

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system uses the bathtub's own water as a resource to generate the swirling flow. The injected jet automatically induces rotation in the surrounding water, which then carries the jet to create the rotating massage pattern without requiring external power or control mechanisms

Inventive Principle:

Principle #25Self-service

2Adaptability or versatility

If a rotary mechanism is used to produce rotating jet flow, then the massage diversity is improved, but the reliability decreases due to wear and clogging

Engineering Contradiction:

Improvemassage diversityVSAvoidrotation performance reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent eliminates mechanical rotating parts that are subject to wear and clogging by using a fluid dynamic approach. The swirling flow is generated naturally by the interaction between the injected jet and the bathtub water, with no moving parts to fail

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system uses the bathtub's own water as a resource to generate the swirling flow. The injected jet automatically induces rotation in the surrounding water, which then carries the jet to create the rotating massage pattern without requiring external power or control mechanisms

Inventive Principle:

Principle #25Self-service

3Adaptability or versatility

If a double nested structure is used, then the rotary jet flow is achieved, but the manufacturing cost increases and fabrication becomes more difficult

Engineering Contradiction:

Improverotary jet flow capabilityVSAvoidnozzle fabrication ease

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent extracts the essential function of generating swirling flow from the complex double-nested mechanical structure. By removing the mechanical rotation mechanism and using only a simple nozzle to inject jet into the bathtub water, the design achieves the same effect with much simpler manufacturing requirements

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical rotary system with a fluid dynamic system. The swirling jet flow is generated by the interaction between the injected jet and the co-rotating water flow in the bathtub, eliminating the need for mechanical rotating components while achieving the same massage diversity effect

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Device complexity

If a narrow gap structure is used, then the rotary support is achieved, but the reliability decreases due to clogging with dust

Engineering Contradiction:

Improverotary support structureVSAvoidgap clogging resistance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent extracts the essential function of generating swirling flow from the complex double-nested mechanical structure. By removing the mechanical rotation mechanism and using only a simple nozzle to inject jet into the bathtub water, the design achieves the same effect with much simpler manufacturing requirements

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical rotary system with a fluid dynamic system. The swirling jet flow is generated by the interaction between the injected jet and the co-rotating water flow in the bathtub, eliminating the need for mechanical rotating components while achieving the same massage diversity effect

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 achieves a diverse and relaxing massage experience by producing a swirling jet flow that can envelop the body, reducing the risk of clogging and wear, and allowing for adjustable bubble mixing to enhance or reduce stimulation, providing a feeling similar to manual massage without the complexity of rotary components.

Implementation Method 1

a channel cross-section shrinking section 23 having a reduced channel cross section relative to the running water introduction section 22, and a chamber 25 having a channel cross-section abrupt expansion section 24 at one end (upstream end) where the channel cross section is abruptly expanded relative to the channel cross-section shrinking section 23

Methodology Applied

Scientific EffectFlow separation: Flow Separation

Implementation Method 2

the jet flow swirls about the central axis C by the back-flow action in the chamber 25 and is ejected from the ejection port 26 as a swirling jet flow

Methodology Applied

Scientific EffectVortex formation: Vortex Ring

Data Source

PatentEP2130524B1Jet bath device

Publication Date: 2014.04.23 TOTO LTD

Figure 1A~1B
Figure 2~3
Figure 4A~4B

AI summary

A jetted bathtub includes: a bathtub; a suction port opening in a wall of the bathtub and allowing water stored in the bathtub to be sucked therein; a pressurizer configured to suck water from the suction port, and pressurize and discharge the water; and a jet nozzle having a single tube held on the wall below a rim of the bathtub, the jet nozzle being configured to eject water introduced into the tube so that the water is ejected into the bathtub with its ejection direction being varied. The tube includes: a running water introduction section configured to receive water supplied from the pressurizer; a channel cross-section shrinking section communicating with the running water introduction section on the downstream side of the running water introduction section, and having a reduced channel cross section relative to the running water introduction section; and a chamber communicating with the channel cross-section shrinking section on the downstream side of the channel cross-section shrinking section, and having at its upstream end a channel cross-section abrupt expansion section with a channel cross section abruptly expanded relative to the channel cross-section shrinking section and at its downstream end an ejection port facing the inside of the bathtub.