Dishwasher Switching Valve Flow Path for Low-Noise Mode Changes

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Solution Overview

Problem

Dishwashers experience vibration and noise issues due to back pressure on the switching valve, which affects operation efficiency and mode switching time.

Innovation Solution

A dishwasher design featuring a flow path distributor with support ribs and a drive motor to rotate the distributor, limiting water flow and reducing pressure on the valve, thereby minimizing vibration and noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a switching valve is used to distribute washing water to multiple injection arms, then injection mode switching capability is improved, but back pressure and vibration are generated causing noise

Engineering Contradiction:
Improveinjection mode switching capabilityVSAvoidnoise and vibration
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts and removes the harmful sub-flow of washing water that causes back pressure on the switching valve. By providing a dedicated sub-flow path that bypasses the valve, the harmful fluid flow is separated from the main distribution function, eliminating vibration and noise while preserving mode switching capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary sub-flow path with a sub-flow hole that acts as a mediator. This intermediate structure allows washing water to flow selectively to different injection arms without creating back pressure on the switching valve, thus reducing noise and vibration while maintaining adaptability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If a switching valve is used to distribute washing water, then multi-directional injection is enabled, but the valve structure becomes complex

Engineering Contradiction:
Improvemulti-directional injectionVSAvoidvalve structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the washing water flow path into multiple independent channels, each with its own injection arm supply hole. This segmentation allows simple on/off control for each injection arm without requiring a complex switching mechanism, reducing valve structure complexity while maintaining multi-directional injection capability.

Inventive Principle:
Principle #1Segmentation

3Productivity

If washing water flows through the switching valve to reach injection arms, then water distribution is achieved, but back pressure causes vibration and extended mode switching time

Engineering Contradiction:
Improvemode switching speedVSAvoidback pressure on valve
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The patent extracts the sub-flow component that causes back pressure and removes it from the main valve path. By providing a separate sub-flow hole that bypasses the switching valve, the harmful pressure buildup is eliminated, enabling faster mode switching without valve vibration.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent prepares alternative flow paths in advance through the sub-flow hole configuration. When mode switching is needed, water can immediately redirect through the pre-configured sub-flow path without waiting for valve pressure equalization, reducing mode switching time and eliminating back pressure effects.

Inventive Principle:
Principle #10Preliminary action

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 reduces vibration and noise, enhances durability, and allows for smoother injection mode switching, decreasing the time required to change modes.

Implementation Method 1

a space between the flow path distributor and the injection flow path coupling portion is provided with a plurality of support ribs limiting a flow path of washing water

Methodology Applied
Scientific EffectFluid flow limitation:

Implementation Method 2

The washing water is pressurized with a high pressure by the washing pump and is transferred to the injection arm

Methodology Applied
Scientific EffectPressure generation:

Implementation Method 3

the washing water moved to the injection arm is injected at a high pressure through an injection port formed in the injection arm. The washing water injected at a high pressure hits a surface of the washing target

Methodology Applied
Scientific EffectHigh pressure fluid injection:

Data Source

PatentEP3750469B1dishwasher
Publication Date: 2023.09.06 LG ELECTRONICS INC
  • EP3750469B1 patent drawingFigure 1
  • EP3750469B1 patent drawingFigure 2
  • EP3750469B1 patent drawingFigure 3

AI summary

Disclosed is a dishwasher including a case for receiving a washing object; a plurality of injection arms for injecting washing water into the case; a sump disposed at a lower side of the case to store the washing water and including an injection flow path coupling portion in which a plurality of injection arm supply holes communicating with the plurality of injection arms are respectively formed; a washing pump for supplying washing water stored in the sump to the plurality of injection arms through the injection flow path coupling portion; and a switching valve disposed in the injection flow path coupling portion and including a flow path distributor for distributing washing water to at least one of the plurality of injection arms, wherein the flow path distributor has a plurality of distribution holes and is rotatably disposed in the injection flow path coupling portion, (i) when the flow path distributor is in a reference position, the plurality of distribution holes are positioned so that all of the plurality of injection arm supply holes are opened, (ii) when the flow path distributor is rotated by a first angle from a reference position, the plurality of distribution holes are positioned so that any one of the plurality of injection arm supply holes is opened, and wherein the injection flow path coupling portion includes a plurality of support ribs protruded toward the flow path distributor and including a support rib corresponding to at least one of the plurality of distribution holes of the flow path distributor in a state rotated by a first angle from the reference position.