Pressure Balance Slide Valve With Low-Loss Flow Cut

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Solution Overview

Problem

Existing pressure compensator arrangements suffer from significant fluid loss when the flow cut function is activated, particularly in circuits with high inlet pressures, leading to unreliable operation and energy inefficiency.

Innovation Solution

A control valve with a closed and open switching position is used, where the second orifice is completely closed in the closed switching position, and a 2-way flow control valve with an auxiliary pressure compensator is employed to maintain pressure at the second control point, ensuring minimal fluid loss and reliable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the control valve is opened to activate the flow cut function, then the main flow is blocked, but a large amount of pressurized fluid is lost to the tank

Engineering Contradiction:
Improveflow cut function reliabilityVSAvoidfluid loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

A 2-way flow control valve is introduced as an intermediary component between the control valve and the tank. This flow control valve restricts the fluid path, allowing the control valve to close the main flow while only a minimal compensating flow passes through the flow control valve to the tank, thereby eliminating excessive fluid loss while maintaining flow cut reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The flow resistance parameter of the path to the tank is changed by introducing the flow control valve with restricted opening. This transforms the original high-flow path into a low-flow path, allowing the system to maintain pressure stability while minimizing fluid loss during flow cut operation

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the control valve is opened to activate the flow cut function, then the main flow is blocked, but pressure stability is compromised

Engineering Contradiction:
Improveflow cut function reliabilityVSAvoidpressure stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The 2-way flow control valve acts as a pressure-stabilizing intermediary that provides a controlled, restricted path for compensating flow. This ensures that when the control valve closes the main flow, pressure can still be maintained through the restricted flow path, preventing pressure instability while enabling reliable flow cut function

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system transitions from a static closed valve to a dynamic controlled system where the flow control valve maintains a restricted but continuous flow path. This dynamic adjustment allows the system to maintain pressure stability during flow cut operation by balancing the closed main flow with the controlled compensating flow

Inventive Principle:
Principle #15Dynamics

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 minimizes fluid loss during the flow cut function, maintaining pressure stability and ensuring reliable operation even under high inlet pressures, thereby enhancing the efficiency and reliability of the pressure compensator assembly.

Implementation Method 1

The auxiliary pressure compensator is acted upon in an opening direction by an auxiliary spring and by the pressure immediately downstream of the third orifice, and is acted upon in a closing direction by the pressure immediately upstream of the third orifice

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

The auxiliary pressure compensator is acted upon in an opening direction by an auxiliary spring

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

the second orifice is completely closed, regardless of the pressure present at the inlet point

Methodology Applied
Scientific EffectValve closure: Valve

Implementation Method 4

The third orifice with constant flow resistance and the flow resistance of the control valve in the open switching position can be suitably coordinated with one another

Methodology Applied
Scientific EffectFlow resistance:

Data Source

PatentEP4411148B1Pressure balance arrangement with switchable flow-cut function
Publication Date: 2025.08.20 ROBERT BOSCH GMBH
  • EP4411148B1 patent drawingFigure 1~2
  • EP4411148B1 patent drawingFigure 3

AI summary

The invention relates to a pressure balance arrangement (10) with a linearly movable control slide (20) which defines a first and a second orifice (21; 22) which can be jointly adjusted by movement of the control slide (20), wherein the second orifice (22) effects a load holding, wherein the control slide (20) is acted upon by a control spring (23) and a pressure at a first control point (11) in the direction of the first end position (41), wherein it is acted upon by a pressure at a second control point (12) in the direction of the second end position (42), wherein a third control point (13) is arranged directly downstream of the first orifice (21) towards the output point (15), wherein the third control point (13) is fluidically connected to the second control point (12) via at least a third orifice (73).According to the invention, a control valve (80) is provided with a closed and an open switching position (81; 82), wherein the second control point (12) is connected via the control valve in the open switching position (82) to a fluid return (96) such that the second orifice (22) is completely closed, regardless of the pressure at the inlet point (14).