Hydraulic Control Assembly for Four-Quadrant Actuator Switching

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Solution Overview

Problem

Existing hydraulic control arrangements for actuators, such as differential hydraulic cylinders, are either cost-intensive due to the requirement of multiple solenoid valves and complex electrical control or lack the ability for four-quadrant operation and clear circuit states, making them inefficient and expensive.

Innovation Solution

A hydraulic control arrangement with two working lines, each equipped with unlockable check valves, a proportional valve for continuous resistance regulation, and a short-circuit line with lockable and unlockable check valves, controlled by a magnetically actuated switching valve, allowing for hydraulic control of all check valves with a single switching valve, enabling efficient switching between normal, regeneration, and load holding functions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two solenoid valves are used to enable load-holding and normal/regeneration switching functions, then the control functionality is improved, but the cost and device complexity increase due to the number of solenoid valves and required power electronics

Engineering Contradiction:
Improvecontrol functionalityVSAvoidnumber of solenoid valves and power electronics
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the functions of two separate solenoid valves into a single magnetically actuated switching valve. This switching valve controls both the pilot-operated check valves in the working lines and the lockable check valve in the short-circuit line through a unified magnetic actuation mechanism, thereby reducing component count and simplifying the power electronics requirements while maintaining full control functionality

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single magnetically actuated switching valve performs multiple functions: it controls the pilot pressure for the pilot-operated check valves in the working lines, controls the lockable check valve in the short-circuit line, and enables both load-holding and normal/regeneration switching functions. This multi-functional design eliminates the need for separate solenoid valves for each function

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If mutually releasable check valves are used in the working lines, then the control flexibility is improved, but the switching states become unclear which severely impairs control functionality

Engineering Contradiction:
Improvecontrol flexibilityVSAvoidcontrol functionality
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces asymmetry in the check valve configuration by making one check valve in the short-circuit line lockable while the other remains unlockable. This asymmetric design creates clearly defined switching states: the lockable check valve provides a stable, maintainable state for load-holding function, while the unlockable check valve allows controlled flow. This resolves the ambiguity problem of having all check valves mutually releasable

Inventive Principle:
Principle #4Asymmetry

3Device complexity

If function switching is mechanically configured during project planning or commissioning, then the control arrangement is simplified, but the adaptability to different operating modes is reduced

Engineering Contradiction:
Improvecontrol arrangement structureVSAvoidswitching between operating modes
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent replaces static mechanical configuration with dynamic magnetic control. The magnetically actuated switching valve can be controlled in real-time to switch between different operating modes (load-holding, normal circuit, regeneration circuit) without requiring mechanical reconfiguration. This dynamic control approach maintains a simple control arrangement structure while providing full adaptability to different operating modes during actual operation

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

This solution provides a simple, compact, and cost-effective means to implement force-position control, regeneration, and load holding functions, enabling four-quadrant operation with defined circuit states, reducing the need for multiple solenoid valves and power electronics, and allowing for efficient actuator operation.

Implementation Method 1

a preferably magnetically controlled switching valve, by means of which the pilot-operated check valves arranged in the working lines and the lockable check valve arranged in the short-circuit line can be hydraulically controlled

Methodology Applied
Scientific EffectMagnetic control: Electromagnet

Implementation Method 2

a proportional valve through which the two working lines can be connected, depending on the (switching) position of the proportional valve, to a pressure medium source for pressurizing the associated pressure chamber

Methodology Applied
Scientific EffectHydraulic resistance regulation: Hydraulic Press

Implementation Method 3

A releasable check valve is arranged in each of the two working lines, the blocked flow direction of which from the direction of the pressure chambers can be released or is released by hydraulic control

Methodology Applied
Scientific EffectCheck valve flow control: Valve

Data Source

PatentEP4130493B1Hydraulic control assembly
Publication Date: 2024.03.27 ROBERT BOSCH GMBH
  • EP4130493B1 patent drawingFigure 1

AI summary

The invention relates to a hydraulic control arrangement (1) for actuating a hydraulic actuator (2), with two working lines (4, 6) in each of which an unlockable check valve (23, 24) is arranged; a proportional valve (10) through which the two working lines (4, 6) can be connected to a pressure medium source (8) or to a pressure medium sink (9);and a short-circuit line (25) which connects the two working lines (4, 6) via two check valves (26, 27), wherein one of the check valves (26) arranged in the short-circuit line (25) is lockable and the other of the check valves (27) arranged in the short-circuit line (25) is unlockable, and the control arrangement has a switching valve (18) by which the unlockable check valves (23, 24) arranged in the working lines (4, 6) and the lockable check valve (26) arranged in the short-circuit line (25) can be hydraulically actuated in a switching position of the switching valve (18).