Pressure Control Valve Radial Groove Flow Guidance

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Solution Overview

Problem

Existing pressure control valves in automatic transmissions face challenges in minimizing hydraulic forces and reducing clutch filling time due to inefficiencies in flow profiles and instability at the inflow control edge.

Innovation Solution

A pressure control valve design featuring a circumferential annular groove opposite the inlet opening, a concavely curved constriction with a specific angle and radius, and a constant diameter section, which reduces hydraulic forces and enhances flow guidance, ensuring symmetrical inflow and stable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If a conventional inlet opening design is used, then the structure is simple, but hydraulic forces in the radial direction are not minimized and clutch filling time is extended

Engineering Contradiction:
Improveclutch filling timeVSAvoidvalve slide structure
Core Design Contradiction:
Duration of action of moving objectVSDevice complexity

Solution Approach 1:

The inlet opening is segmented into multiple radial channels distributed around the circumference, with each channel equipped with its own circumferential annular groove. This segmentation allows independent pressure equalization at each inlet location, minimizing radial hydraulic forces while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Circumferential annular grooves are added locally at specific positions opposite the inlet openings to create pressure equalization zones. This local modification optimizes the flow profile at critical locations without requiring complete redesign of the entire valve structure, thus reducing clutch filling time while limiting structural complexity increase.

Inventive Principle:
Principle #3Local quality

2Stability of the object's composition

If the annular groove width is increased, then pressure equalization is improved, but the groove may interfere with other valve components

Engineering Contradiction:
Improvepressure equalizationVSAvoidgroove width
Core Design Contradiction:
Stability of the object's compositionVSArea of stationary object

Solution Approach 1:

The annular grooves are designed with a width that provides sufficient pressure equalization functionality without being excessively large. The groove dimensions are optimized to achieve the necessary pressure balancing effect while maintaining compatibility with other valve components and avoiding interference with the valve slide movement and other internal structures.

Inventive Principle:
Principle #16Partial or excessive action

3Speed

If the constriction angle is increased, then flow deflection is stronger, but turbulence and pressure losses increase

Engineering Contradiction:
Improveflow deflection efficiencyVSAvoidpressure losses
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The constriction geometry incorporates optimized curved surfaces with specific angle ranges (52°-72°, preferably 60°-64°, more preferably 62°) that smoothly guide the hydraulic flow from radial to axial direction. The curved transition surfaces reduce flow separation and turbulence, achieving effective flow deflection while minimizing energy losses and pressure drops.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 design minimizes hydraulic forces, reduces clutch filling time, and provides a stable, dynamic operation that is insensitive to disturbances, improving the overall efficiency and stability of the pressure control valve.

Implementation Method 1

the circumferential annular groove in the valve slide ensures rapid pressure equalization in the circumferential direction of the valve slide

Methodology Applied
Scientific EffectPressure equalization: Pascal's Law

Implementation Method 2

as soon as the inlet control edge 'tears open', i.e. the inlet opening releases at least something, the fluid flows in the direction of the control opening

Methodology Applied
Scientific EffectHydraulic flow: Hydraulic Press

Implementation Method 3

the constriction on the valve slide has a concavely curved section. This concavely curved section leads to a further gradual deflection of the hydraulic flow towards the control opening

Methodology Applied
Scientific EffectFlow deflection: Coanda Effect

Implementation Method 4

which takes place gradually due to the concave curvature and is therefore associated with only small pressure losses

Methodology Applied
Scientific EffectTurbulence reduction: Laminar Flow

Data Source

PatentEP2459908B1Pressure regulating valve
Publication Date: 2013.04.17 ROBERT BOSCH GMBH
  • EP2459908B1 patent drawingFigure 1~2

AI summary

The invention relates to a pressure control valve (10) comprising a housing (12), a valve slide (14) guided in the housing (12), on which at least one infeed control edge (56) is designed that interacts with an infeed opening (44) in the housing (12), wherein there is a constriction in the piston (54) neighboring the infeed control edge (56) that is at least approximately opposite a control opening (46). According to the invention, the valve slide (14) has a circumferential radial groove (70) that lies on the side of the infeed control edge (56) turned away from the constriction (54) and approximately opposite the infeed opening (44).