accumulator

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Solution Overview

Problem

Existing accumulators face challenges in increasing the amount of refrigerant flow while maintaining a large inner diameter outflow pipe, as the outflow pipe diameter is often limited by downstream piping specifications, and bulging methods complicate the use of larger diameters.

Innovation Solution

The accumulator design incorporates a small-diameter tube portion connected to a large-diameter tube portion, with a stepped surface and tapered inner circumferential surface, allowing the gas-liquid separating member to be securely fixed without bulging, thus enabling a larger refrigerant flow without increasing component count.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an outflow pipe with a large inner diameter is used to increase refrigerant flow, then the amount of refrigerant passing through the accumulator increases, but the outflow pipe diameter is limited by downstream piping specifications and bulging methods complicate the design

Engineering Contradiction:
Improveamount of refrigerant flowVSAvoidoutflow pipe design complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The outflow pipe is segmented into two distinct portions: a small-diameter tube portion for connection to the refrigerant outflow port, and a large-diameter tube portion for increasing refrigerant flow capacity within the accumulator body. This segmentation allows each portion to serve its specific function optimally while avoiding the need for bulging operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the outflow pipe have different diameters tailored to their specific functional requirements. The small-diameter portion near the outlet port matches downstream piping specifications, while the large-diameter portion inside the accumulator body maximizes flow capacity. This local differentiation resolves the contradiction between flow rate and compatibility.

Inventive Principle:
Principle #3Local quality

2Reliability

If bulging is performed on the outflow pipe to form a flange portion for holding the gas-liquid separating member, then the separating member can be secured, but it becomes difficult to use an outflow pipe with a partially large diameter

Engineering Contradiction:
Improvegas-liquid separating member fixationVSAvoidoutflow pipe structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The outflow pipe is divided into a small-diameter tube portion and a large-diameter tube portion, eliminating the need for bulging operations. The gas-liquid separating member is held by the natural structural features of these segmented portions, specifically utilizing the stepped configuration where the small-diameter portion connects to the outlet port and the large-diameter portion provides internal flow capacity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bulging operation is extracted and replaced by a simpler stepped tube structure. Instead of deforming the pipe to create a flange portion, the invention uses the inherent geometry of the segmented tube portions to secure the gas-liquid separating member, simplifying the overall structure while maintaining reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If the outflow pipe diameter is increased regardless of downstream piping size, then refrigerant flow capacity improves, but compatibility with downstream piping and assembly becomes difficult

Engineering Contradiction:
Improverefrigerant flow capacityVSAvoidcompatibility with downstream piping
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The outflow pipe is segmented into a small-diameter tube portion that connects to the refrigerant outflow port and matches downstream piping specifications, and a large-diameter tube portion that extends into the accumulator body to maximize flow capacity. This segmentation enables the system to simultaneously achieve high productivity and adaptability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The outflow pipe exhibits local quality variation with different diameters at different locations. The small-diameter portion ensures compatibility with downstream piping components, while the large-diameter portion optimizes refrigerant flow capacity within the accumulator, resolving the contradiction between adaptability and productivity.

Inventive Principle:
Principle #3Local quality

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 ensures smooth refrigerant flow with reduced pressure drop and turbulence, maintaining efficient gas-liquid separation while preventing the need for additional components and complex assembly methods.

Implementation Method 1

a tapered inner circumferential surface that is connected to the cylindrical inner circumferential surface and that reduces in diameter toward the refrigerant outflow hole

Methodology Applied
Scientific EffectTapered flow guidance: Pressure Gradient

Implementation Method 2

an accumulator having a gas-liquid separating member, i.e., cup, for separating the refrigerant flowing in through the refrigerant inflow port into a liquid phase refrigerant and a gas phase refrigerant

Methodology Applied
Scientific EffectGas-liquid separation: Density Gradient

Implementation Method 3

the gas-liquid separating member being nipped between the header and a stepped surface which is an end face of the large-diameter tube portion on the small-diameter tube portion side

Methodology Applied
Scientific EffectMechanical nipping: Mechanical Force

Data Source

PatentEP4656974A1accumulator
Publication Date: 2025.12.03 FUJIKOKI CORP
  • EP4656974A1 patent drawingFigure 1
  • EP4656974A1 patent drawingFigure 2
  • EP4656974A1 patent drawingFigure 3

AI summary

Provided is an accumulator capable of holding a gas-liquid separating body and increasing an amount of refrigerant that passes through, while preventing a number of components from increasing. The accumulator includes a body portion having an opening on at least one end thereof, a header including a refrigerant inflow hole and a refrigerant outflow hole, the header blocking an opening on one end of the body portion, a gas-liquid separating member disposed within the body portion and facing the refrigerant inflow hole and the refrigerant outflow hole, and an outflow pipe connected to the refrigerant outflow hole, wherein the outflow pipe includes a small-diameter tube portion that is inserted and fixed to the refrigerant outflow hole, and a large-diameter tube portion having a larger diameter than the small-diameter tube portion and that is arranged within the body portion, the gas-liquid separating member being nipped between the header and a stepped surface which is an end face of the large-diameter tube portion on the small-diameter tube portion side, and wherein the outflow pipe includes a cylindrical inner circumferential surface that is formed inside the small-diameter tube portion and a tapered inner circumferential surface that is connected to the cylindrical inner circumferential surface and that reduces in diameter toward the refrigerant outflow hole.