Closed-Circuit Pump Eliminates Valve Pressure Loss in Ultra-High Pressure Generator

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Solution Overview

Problem

Existing ultra-high pressure generators experience pressure fluctuations and mechanical efficiency drops due to pressure loss in directional control valves during high-pressure fluid discharge, affecting the quality of water jets in cutting applications.

Innovation Solution

An ultra-high pressure generator with a closed-circuit working medium pump that eliminates the need for directional control valves by using a supply circuit, selection circuit, and recovery circuit to regulate working medium pressure, ensuring stable pressure waveforms and improved mechanical efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a directional control valve is used to control the hydraulic pressure generator, then the high pressure fluid can be discharged, but pressure loss occurs in the directional control valve causing pressure fluctuations and mechanical efficiency drop

Engineering Contradiction:
Improvedischarge of high pressure fluidVSAvoidpressure loss in directional control valve
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent removes the directional control valve from the system entirely by using a closed-circuit hydraulic pump that can directly reverse the flow direction of the working medium. This extraction of the problematic component eliminates the pressure loss and responsiveness issues associated with directional control valves while maintaining the ability to discharge high pressure fluid continuously.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical directional control valve system with a closed-circuit hydraulic pump system that uses hydraulic pressure to directly control the reciprocating motion of the intensifier piston. This substitution eliminates the need for mechanical valve switching and achieves more efficient flow direction control through hydraulic means.

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

2Loss of energy

If the directional control valve is increased in size to reduce pressure loss, then pressure loss decreases, but responsiveness of the directional control valve deteriorates

Engineering Contradiction:
Improvepressure loss in directional control valveVSAvoidresponsiveness of directional control valve
Core Design Contradiction:
Loss of energyVSSpeed

Solution Approach 1:

By removing the directional control valve entirely and replacing it with a closed-circuit hydraulic pump system, the patent eliminates the trade-off between valve size and responsiveness. The hydraulic pump directly controls flow direction through pressure differential, achieving both low pressure loss and high responsiveness without the conflicting requirements that plague directional control valves.

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If the discharge of high pressure fluid is stopped, then the cutting process stops, but the pressure rises temporarily by several tens of times the pressure loss in the directional control valve

Engineering Contradiction:
Improvecontinuous discharge of high pressure fluidVSAvoidtemporary abnormal rise of hydraulic pressure
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The closed-circuit hydraulic pump system inherently provides feedback control through its pressure differential operation. When discharge stops, the system automatically balances pressures through the closed circuit, preventing the runaway pressure buildup that occurs in open-circuit systems with directional control valves. The intensifier piston position and hydraulic pressure are continuously balanced, eliminating temporary abnormal pressure rises.

Inventive Principle:
Principle #23Feedback

4Productivity

If a double-acting intensifier is used to achieve continuous discharge, then productivity improves, but pressure loss in the directional control valve causes mechanical efficiency to drop

Engineering Contradiction:
Improvecontinuous discharge capabilityVSAvoidmechanical efficiency
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent replaces the mechanical directional control valve system with a closed-circuit hydraulic pump system that uses hydraulic pressure to control the intensifier. This substitution maintains the continuous discharge capability of the double-acting intensifier while eliminating the mechanical efficiency losses caused by directional control valve pressure drops, achieving both high productivity and high mechanical efficiency.

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 solution achieves stable pressure waveforms with reduced pressure fluctuations and enhanced mechanical efficiency, leading to improved water jet quality and reduced cooling water requirements.

Implementation Method 1

a closed-circuit working medium pump that has a first port and a second port as suction/discharge ports for the working medium, and sucks/discharges the working medium from/to the first chamber and the second chamber respectively via the first port and the second port

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

The pressure of the pressurized fluid is pressurized by a factor of an intensify ratio in the pressure of the working medium

Methodology Applied
Scientific EffectHydraulic intensification: Hydraulic Press

Data Source

PatentEP2998579B1Ultra-high pressure generator
Publication Date: 2020.05.06 SUGINO MACHINE
  • EP2998579B1 patent drawingFigure 1
  • EP2998579B1 patent drawingFigure 2

AI summary

An ultra-high pressure generator (70) includes: an intensifier (40) that discharges pressurized fluid (F2) and has a double-acting drive cylinder (44) formed to have a first chamber (41) and a second chamber (42) which are delimited by a piston (43) driven by a working medium (F1), high pressure cylinders (451,452) which discharge the pressurized fluid (F2), and plungers (461,462) which reciprocate with the piston (43) in the high pressure cylinders (461,462); a closed-circuit working medium pump (11) having a first port (111) and a second port (112) as suction/discharge ports for the working medium (F1) ; a drive source (12) that drives the closed-circuit working medium pump (11) ; a first working medium channel (32) that communicates the first chamber (41) with the first port (111) ; and a second working medium channel (33) that communicates the second chamber (42) with the second port (112), wherein the closed-circuit working medium pump (11) sucks/discharges the working medium (F1) from/to the first and second chambers (41,42) respectively via the first and second ports (111,112) to drive the intensifier (40).