Pressure Control Valve with Dynamic Throttle Area

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Solution Overview

Problem

Existing pressure control valves with extreme hysteresis in high-pressure hydraulics fail to provide a reliable and precise detection of opening and closing pressures, leading to undefined pressure transitions and inadequate throttle effects.

Innovation Solution

A pressure control valve design featuring a defined positive overlap between the piston head and low-pressure port, with a direct connection blocked in the closed position, resulting in a sudden and pronounced lifting stroke, and a stroke-dependent throttle area that ensures a sharp transition at both opening and closing pressures, facilitated by a sliding fit without seals and a specific chamber geometry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional pressure control valve design is used with a piston head carrying a locking sliding seal, then the valve structure is stable and sealed, but the throttle effect remains constant and independent of stroke, preventing reliable detection of opening and closing pressures

Engineering Contradiction:
Improvepressure detection precisionVSAvoidvalve structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the conventional static throttle point with a dynamic throttle area formed by the positive overlap between the piston head and low-pressure port. This throttle area varies with piston stroke, providing a stroke-dependent throttle effect that enables reliable pressure detection. The dynamic nature of the throttle area allows it to adapt to different stroke positions, creating distinct pressure transitions at opening and closing pressures.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention separates the sealing function from the throttling function. The piston head is guided in the chamber without a seal between them, eliminating the locking sliding seal. Instead, sealing is achieved through the interference fit between the piston head outer circumference and chamber wall, while throttling is achieved through the variable positive overlap area, allowing independent optimization of both functions.

Inventive Principle:
Principle #1Segmentation

2Speed

If the piston head has a narrow channel to the low-pressure connection, then the lifting movement of the cone is increased, but the pressure transition becomes flat and undefined

Engineering Contradiction:
Improvepiston lifting speedVSAvoidpressure transition sharpness
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent transitions from a one-dimensional narrow channel throttle to a two-dimensional variable area throttle formed by the positive overlap between the piston head and low-pressure port. This dimensional change allows the throttle area to vary dynamically with stroke, providing both rapid piston movement and sharp pressure transitions. The annular throttle area increases with stroke, enabling controlled acceleration while maintaining pressure sharpness.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Force

If the positive overlap between piston head and low-pressure port is increased, then the throttle effect is amplified, but the device complexity increases

Engineering Contradiction:
Improvethrottle effectVSAvoidchamber geometry complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent combines the piston head guiding function and throttling function into a single integrated design. The positive overlap between the piston head and low-pressure port serves dual purposes: guiding the piston head movement and creating the variable throttle area. This merging eliminates the need for separate sealing elements and throttle components, reducing overall device complexity while maintaining effective throttle control.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of operation

If the piston plate is guided with a sliding fit without seals, then the movement is smooth and throttle range is variable, but manufacturing precision requirements increase

Engineering Contradiction:
Improvepiston movement smoothnessVSAvoidspool fit precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent specifies a precise interference fit range of 0.1 to 0.2 mm based on diameter for the piston head outer circumference in the chamber. This controlled parameter change creates optimal sliding conditions that balance smooth movement with manufacturing feasibility. The specific fit range ensures sufficient clearance for smooth operation while maintaining tight tolerances for reliable throttling control.

Inventive Principle:
Principle #35Parameter changes

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 achieves a clear and steep pressure transition, allowing for precise detection and control of pressure changes, maintaining the open position without dynamic pressure issues and enhancing the throttle effect's linearity, ensuring reliable operation and easy manual actuation.

Implementation Method 1

the throttle area is defined by the positive overlap between the piston head and the low-pressure port located on the side of the chamber

Methodology Applied
Scientific EffectThrottle effect: Pressure Drop

Implementation Method 2

The circumference of the piston plate is expediently guided in the chamber without a seal, with a sliding fit to the chamber wall

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3076058B1Pressure control valve
Publication Date: 2017.08.16 HAWE HYDRAULIK SE
  • EP3076058B1 patent drawingFigure 1

AI summary

In a pressure regulating valve (V) for setting an upper opening pressure defined by a regulating spring (11) and a seat (4) and a significantly lower lower closing pressure defined by the regulating spring (11) and a piston plate (9), wherein a chamber (7) for the piston plate (9) is provided downstream of the seat (4), the bearing surface (D) of which is a multiple of the bearing surface (d) of the seat (4), the piston plate (9) in the closed position of the cone (8) with positive overlap (U) interacts with a low-pressure port (12) located laterally in the chamber, and a throttling region (15) is defined by the piston plate (9) within the positive overlap (U) for retarding contact movements and accelerating lifting movements of the cone (8).