Mechanical Flow Path Switching for Precise Washer Detergent Dosing

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Solution Overview

Problem

Existing automatic detergent delivery systems for washing machines are complex, costly, and lack accurate control over detergent quantity due to varying viscosity with temperature, leading to inefficiencies and increased costs.

Innovation Solution

A simplified liquid detergent delivery device using a flow path switcher with non-electromagnetic mechanical valves and a Venturi negative pressure generator, which replaces complex electronic controls with mechanical ones, ensuring accurate detergent delivery and preventing backflow into the water supply.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If electronic control systems with sensors and microprocessors are used to control detergent delivery, then delivery precision can be improved, but device complexity and cost increase significantly

Engineering Contradiction:
Improvedetergent delivery precisionVSAvoidsystem structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces electronic control systems with a purely mechanical control mechanism. The flow path switcher uses mechanical components (valve core, valve seats, springs) to control detergent flow based on water pressure variations during different washing phases, eliminating the need for microprocessors, sensors, and electronic circuits while achieving accurate detergent delivery control

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The mechanical control system automatically responds to water pressure changes during washing cycles. The valve core moves passively in response to pressure differential between inlet and outlet, enabling the system to self-regulate detergent delivery without external electronic control signals or power consumption

Inventive Principle:
Principle #25Self-service

2Productivity

If liquid pumps are used to deliver detergent, then delivery capability is improved, but measurement accuracy deteriorates due to viscosity variations with temperature

Engineering Contradiction:
Improvedetergent delivery capabilityVSAvoiddetergent quantity measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent uses water pressure from the washing machine's own water supply system to drive detergent delivery through the Venturi effect and pressure differential. This hydraulic approach eliminates the need for separate electric pumps, and the pressure-driven flow rate naturally compensates for viscosity variations, maintaining measurement accuracy across different temperatures

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The system exploits changes in water pressure parameters during different washing phases (filling, washing, rinsing) to control detergent delivery timing and quantity. The pressure differential between inlet and outlet of the flow path switcher serves as the control parameter, automatically adjusting delivery based on washing cycle stage without requiring temperature compensation

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If inlet tubes and Venturi negative pressure effects are used for detergent delivery, then delivery function is achieved, but delivery quantity control accuracy deteriorates

Engineering Contradiction:
Improveautomatic detergent delivery functionVSAvoiddetergent addition quantity accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent employs a dynamic mechanical valve system where the valve core position changes continuously in response to water pressure variations. During different washing phases, the pressure differential dynamically adjusts the valve opening degree, enabling automatic and accurate control of detergent delivery quantity without complex electronic sensors

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The flow path switcher acts as an intermediary mechanism between the water supply system and detergent delivery system. It translates water pressure variations into corresponding detergent flow rate adjustments, mediating the control function and achieving accurate dosage control through mechanical means

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If multiple valves and complex control circuits are used to prevent backflow, then reliability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvebackflow prevention reliabilityVSAvoidvalve and circuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of using multiple active valves and electronic circuits to prevent backflow, the patent inverts the approach by using a passive check valve design where the flow path geometry and pressure differential naturally prevent backflow. The mechanical valve core and spring system automatically closes in reverse pressure conditions, achieving backflow prevention with minimal components

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

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 provides a cost-effective and reliable method for accurately delivering detergent, preventing backflow, and enhancing operational efficiency by using mechanical valves to manage detergent flow, thus addressing the complexity and cost issues of prior systems.

Implementation Method 1

When the influent water flow flows, the detergent delivery pipeline will produce a Venturi negative pressure effect, and under such a negative pressure, detergent is sucked in the delivery tube for delivery

Methodology Applied
Scientific EffectVenturi negative pressure effect: Venturi Effect

Data Source

PatentEP3521500B1Flow patch switcher and liquid detergent dispensing apparatus
Publication Date: 2024.10.02 HANGZHOU KAMBAYASHI ELECTRONICS
  • EP3521500B1 patent drawingFigure 1
  • EP3521500B1 patent drawingFigure 2
  • EP3521500B1 patent drawingFigure 3

AI summary

Disclosed herein is a flow path switcher, comprising a valve core, a shell and a base. The shell comprises a valve seat A, a valve seat B, a channel of valve seat A, a channel of valve seat B, an outlet and an inlet. The base comprises a valve seat C, the valve seat A and the valve seat B are located on one side of the valve core and the valve seat C is located on the other side of the valve core. Also a liquid detergent delivery device with the flow path switcher is disclosed, comprising a main channel, a piston, a one-way valve D, a one-way valve E, a detergent box A and a Venturi negative pressure generator. The flow path switcher is connected between the entrance of the Venturi negative pressure generator and the exit of the main channel, the inlet of the flow path switcher and the outlet of the flow path switcher are connected to the exit of the main channel and the entrance of the Venturi negative pressure generator, respectively, the channel of valve seat B is connected to the exit of the one-way valve D, the exit of the one-way valve D is connected to the entrance of the piston, the entrance of the one-way valve D is connected to the detergent box A, the exit of the piston is connected to the entrance of the one-way valve E, and the exit of the one-way valve E is connected to the negative pressure port of the Venturi negative pressure generator. The present invention is used for delivery of detergents of washing machines.