Composite Valve Segmentation for Flow Control Precision

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Solution Overview

Problem

Existing composite valves for heat pump systems face challenges in achieving precise flow rate control in both small and large flow rate regions while minimizing pressure loss and size, leading to increased cost, power consumption, and potential malfunctions due to foreign material clogging and inadequate sealing.

Innovation Solution

A composite valve design featuring a piston-type first valve body, a needle-type second valve body, and a pilot valve body, where the pilot valve body is driven by the elevating motion of the valve shaft to control the flow rate, with a valve body member and pressing member configuration that enhances sealing and prevents undesired opening, using a spring-energized mechanism and a spherical or curved surface seal to maintain contact pressure and prevent tilting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single electrically operated valve is used to replace separate expansion valves and electromagnetic valves, then device complexity is reduced, but it becomes difficult to achieve both precise small flow rate control and large flow rate bypassing without increasing valve size and power consumption

Engineering Contradiction:
Improvenumber of valvesVSAvoidvalve size
Core Design Contradiction:
Device complexityVSVolume of moving object

Solution Approach 1:

The valve is divided into two independent valve bodies: a first valve body for large flow rate bypassing with a large valve bore, and a second valve body for small flow rate control with a small valve bore. This segmentation allows each valve to be optimized for its specific function without compromising the other, solving the contradiction between device simplicity and valve size requirements.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If a single electrically operated valve is used to replace separate expansion valves and electromagnetic valves, then device complexity is reduced, but power consumption increases due to the need for a large motor to handle both small and large flow rates

Engineering Contradiction:
Improvenumber of valvesVSAvoidpower consumption
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The valve is divided into two independent valve bodies: a first valve body for large flow rate bypassing with a large valve bore, and a second valve body for small flow rate control with a small valve bore. This segmentation allows each valve to be optimized for its specific function without compromising the other, solving the contradiction between device simplicity and valve size requirements.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If the second valve body for small flow rate control is given sufficient space for optimal dimensioning, then flow rate control precision is improved, but the overall valve size increases

Engineering Contradiction:
Improveflow rate control precisionVSAvoidvalve size
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The valve is divided into two independent valve bodies: a first valve body for large flow rate bypassing with a large valve bore, and a second valve body for small flow rate control with a small valve bore. This segmentation allows each valve to be optimized for its specific function without compromising the other, solving the contradiction between device simplicity and valve size requirements.

Inventive Principle:
Principle #1Segmentation

4Ease of manufacture

If the pilot valve body uses a simple flat surface seal, then manufacturing is easier, but sealing performance is inadequate and the valve may undesirably open

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidsealing performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The pilot valve body's sealing surface is designed with a curved surface that contacts the pilot valve seat, replacing a simple flat surface. This curved contact provides superior sealing performance and prevents unwanted valve opening while maintaining manufacturing feasibility, resolving the contradiction between ease of manufacture and sealing reliability.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 allows for optimal dimensioning and shaping of the second control valve for small flow rate control, secure operation of the first control valve at desired timings, improved sealing performance, and reduced risk of malfunctions, achieving precise flow rate control and reduced pressure loss without increasing size or power consumption.

Implementation Method 1

a valve body pressing member (62) which is energized downward by a spring member (26) so as to position the valve body member (61) close to or away from an opening edge portion (19e) of the pilot passage (19)

Methodology Applied
Scientific EffectSpring force: Spring

Data Source

PatentEP2650575B1Composite valve
Publication Date: 2015.04.01 FUJIKOKI CORP
  • EP2650575B1 patent drawingFigure 1
  • EP2650575B1 patent drawingFigure 2A~2B
  • EP2650575B1 patent drawingFigure 3

AI summary

The invention provides a composite valve which can achieve both an improvement of a flow rate control precision in a small flow rate region and an increase of a controllable flow rate (a reduction of a pressure loss), and can enhance a sealing performance of a pilot passage by a pilot valve body, whereby it is possible to securely prevent a malfunction and it is possible to enhance a reliability. When a lift amount of a second valve body (24) for a small flow rate control is equal to or less than a predetermined amount (Tc), a pilot passage (19) is closed by a pilot valve body (60) which is slidable on an inner wall of a bush retention body (28), and a first valve port (13) is closed by a first valve body (15) for a large flow rate control, thereby taking a small flow rate control state in which a flow rate is controlled in correspondence to a lift amount of the second valve body (24). When the lift amount of the second valve body (24) goes beyond the predetermined amount (Tc), a pilot valve body (20) is raised in correspondence to a rising motion of a valve shaft (25) so as to open the pilot passage (19), thereby taking a large flow rate control state in which the first valve body (15) opens the first valve port (13). The pilot valve body (60) is outward inserted slidably to the valve shaft (25), and is energized downward by a spring member (26) so as to close the pilot passage (19). Further, when the lift amount of the second valve body (24) is increased more than the predetermined amount Tc, the pilot valve body (60) is caught on the valve shaft (25) so as to be pulled up.