Piston Cooling Nozzle Structure for High-Flow Vibration-Free Oil Jets

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Solution Overview

Problem

Piston cooling nozzles with ball valves face issues of decreased volume flow with increasing opening pressure and vibration excitation, which affect their efficiency and durability.

Innovation Solution

A piston cooling nozzle design featuring a piston biased by a spring against a valve seat, with a transverse duct communicating to a longitudinal duct, creating a laminar flow that enhances jet concentration and avoids vibration, allowing for variable opening pressure and flow rate without reducing volume flow, and featuring a dome-shaped piston head and cylindrical shoulder for stability and efficient oil flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a ball valve is used in the piston cooling nozzle, then the valve structure is simple, but the volume flow decreases with increasing opening pressure and vibrations are excited

Engineering Contradiction:
Improvevalve structureVSAvoidvolume flow
Core Design Contradiction:
Device complexityVSQuantity of substance

Solution Approach 1:

The patent replaces the ball valve mechanism with a piston valve mechanism. The piston valve uses a plug head that selectively abuts against an annular closure seat, controlled by pressure differential across the piston and spring force. This substitution eliminates the vibration and volume flow degradation issues inherent in ball valve designs while maintaining structural simplicity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention utilizes hydraulic principles by using pressure oil acting on the piston surface to control valve opening. The opening pressure is determined by the balance between spring force and oil pressure acting on the piston, allowing precise control of the cooling oil flow without mechanical complexity or vibration.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Device complexity

If a ball valve is used in the piston cooling nozzle, then the valve structure is simple, but vibration excitation occurs

Engineering Contradiction:
Improvevalve structureVSAvoidvibration
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the ball valve mechanism with a piston valve mechanism. The piston valve uses a plug head that selectively abuts against an annular closure seat, controlled by pressure differential across the piston and spring force. This substitution eliminates the vibration and volume flow degradation issues inherent in ball valve designs while maintaining structural simplicity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Temperature

If the opening pressure is increased to improve cooling effectiveness, then the cooling performance improves, but the volume flow through the nozzle decreases

Engineering Contradiction:
Improvecooling effectivenessVSAvoidvolume flow
Core Design Contradiction:
TemperatureVSQuantity of substance

Solution Approach 1:

The invention utilizes hydraulic principles by using pressure oil acting on the piston surface to control valve opening. The opening pressure is determined by the balance between spring force and oil pressure acting on the piston, allowing precise control of the cooling oil flow without mechanical complexity or vibration.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent allows independent adjustment of opening pressure and flow rate parameters. The opening pressure can be varied by selecting different spring characteristics, while the flow rate is controlled by the cross-section of the outlet opening. This decoupling enables optimization of both cooling effectiveness and volume flow without compromise.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If a piston valve is used instead of a ball valve, then vibration is avoided and durability is improved, but the device complexity increases

Engineering Contradiction:
ImprovedurabilityVSAvoidvalve structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the ball valve mechanism with a piston valve mechanism. The piston valve uses a plug head that selectively abuts against an annular closure seat, controlled by pressure differential across the piston and spring force. This substitution eliminates the vibration and volume flow degradation issues inherent in ball valve designs while maintaining structural simplicity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 improves jet pattern concentration, reduces flow losses, and prevents vibration excitation, enabling adjustable opening pressure and flow rate parameters while maintaining high volume flow and structural stability.

Implementation Method 1

The piston is biased against a valve seat by means of a spring

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

If the oil pressure exceeds an opening pressure, the pressure oil flows through the piston cooling nozzle

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 3

with a transverse duct communicating to a longitudinal duct, creating a laminar flow that enhances jet concentration

Methodology Applied
Scientific EffectLaminar flow: Laminar Flow

Data Source

PatentEP3728809B1Piston cooling nozzle
Publication Date: 2021.10.06 VOLKSWAGEN AG
  • EP3728809B1 patent drawingFigure 1~2

AI summary

The invention relates to a piston cooling nozzle (1) comprising a cylindrical housing (2), a piston (3), and a spring (10). The piston (3) is arranged in the cylindrical housing (2) in a movable manner against the pressure of a pressurized oil, and the piston (3) is biased against a valve seat (5) by means of the spring (10). The valve seat (5) interacts with a piston head (6), and a cavity is formed downstream of the valve seat (5), wherein a transverse line (7) extends at least partly in the piston (3) starting from the cavity (4), and the transverse line (7) opens into a longitudinal line (8). The piston cooling nozzle (1) is improved in that the piston (3) has a shaft (14), and the longitudinal line (8) extends within the shaft (14), said shaft (14) being surrounded by the spring (10) and passing through an opening (13) in a base part (12).