Directional Control Valve Cam Guide for Low-Friction Sealing

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Solution Overview

Problem

Existing multi-way valves in motor vehicle thermal management systems face issues with high frictional forces between the valve member and housing, leading to increased power requirements for actuators and complex assembly processes.

Innovation Solution

A directional control valve design featuring a link guide that urges the valve member into a sealing contact state and then releases it, reducing static friction, and a rail guide that allows relative movement between actuating and sealing parts, enabling low-friction movement and fluid-tight sealing without additional sliding or sealing measures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a rotary piston valve element is used in known multi-way valves, then the valve can control fluid flow between multiple ports, but high frictional forces occur between the valve element and valve seat leading to increased power requirements for actuators

Engineering Contradiction:
Improvefluid flow control capabilityVSAvoidactuator power requirement
Core Design Contradiction:
Adaptability or versatilityVSPower

Solution Approach 1:

The valve element is designed to dynamically change its contact state with the valve housing. During positioning movement, the valve element moves essentially frictionlessly with minimal contact. When closing a fluid connection, the cam guide forces the valve element into a closed-contact switching state with increased frictional force to ensure sealing. This dynamic transition between low-friction and high-friction states resolves the contradiction between versatility and power requirement.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The valve element periodically enters and exits the closed-contact switching state during its actuation cycle. The cam guide mechanism creates periodic zones of increased friction at specific positions to ensure sealing, while the remainder of the movement path maintains low friction. This periodic application of friction force allows the valve to achieve reliable sealing without requiring continuously high actuator power.

Inventive Principle:
Principle #19Periodic action

2Reliability

If the valve element is forced into closed-contact switching state to ensure sealing, then fluid-tight closure is achieved, but frictional force increases continuously during operation

Engineering Contradiction:
Improvesealing reliabilityVSAvoidenergy loss due to friction
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The cam guide creates localized zones of increased friction only at specific positions where sealing is required. The valve element experiences high frictional force only in the immediate vicinity of the closed-contact switching state, while the majority of its movement path maintains low friction. This localized application of friction force ensures reliable sealing without continuous energy loss.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The valve element is forced into closed-contact with excessive frictional force only partially, specifically only when closing a fluid connection. The cam guide mechanism applies additional friction force selectively at the sealing position rather than continuously throughout the entire valve element movement, thereby achieving reliable sealing while minimizing overall energy loss.

Inventive Principle:
Principle #16Partial or excessive action

3Manufacturing precision

If known multi-way valves use complex spool piston designs with multiple sealing elements, then fluid flow can be controlled precisely, but the number of parts increases making assembly complicated

Engineering Contradiction:
Improvefluid flow control precisionVSAvoidnumber of parts
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention merges the functions of multiple separate sealing elements into a single integrated valve element design. The valve element itself is shaped to provide sealing surfaces for multiple fluid connections without requiring additional sealing rings or elements. This consolidation maintains precise fluid flow control while significantly reducing the number of parts and simplifying assembly.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The valve element is designed as a multi-functional component that simultaneously controls fluid flow to multiple ports and provides sealing for all connections. Rather than requiring separate specialized sealing elements for each fluid connection, the single valve element performs all sealing functions, reducing part count while maintaining manufacturing precision.

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

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 achieves low-friction movement, reduced wear, and longer longevity, allowing for the use of less expensive and less powerful actuators while maintaining fluid-tight sealing, thus simplifying the assembly and operation of the valve.

Implementation Method 1

the cam guide forces the valve element against the valve housing, so that any static friction existing between the valve element and the valve housing is increased, particularly continuously

Methodology Applied
Scientific EffectStatic friction: Static Friction

Implementation Method 2

When the closed-contact switching state is exited, the cam guide moves the valve element away from the valve housing, so that the static friction existing between the valve housing and the valve element decreases again, particularly continuously

Methodology Applied
Scientific EffectStatic friction: Static Friction

Data Source

PatentEP4027042A1Motor vehicle directional control valve for adjusting a fluid flow
Publication Date: 2022.07.13 WOCO INDUSTRIETECHNIK GMBH
  • EP4027042A1 patent drawingFigure 1~2
  • EP4027042A1 patent drawingFigure 3~4
  • EP4027042A1 patent drawingFigure 5~6

AI summary

The present invention relates to a directional control valve (1) for adjusting a fluid flow, such as a coolant flow, between at least two switching states, comprising a valve housing (3), an adjustable valve element (5) and a cam guide (39) which is configured to force the valve element into a sealing contact switching state with the valve housing and to lead it into a release switching state which is set back with respect to the sealing contact switching state.