Valve Seating Device with Cone Piston for Impact Control

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Solution Overview

Problem

In internal combustion engines, hydraulic lost motion systems can cause engine valves to impact their seats at high velocities due to rapid fluid release, leading to potential damage, and existing solutions fail to provide consistent valve seating control across varying engine conditions.

Innovation Solution

A valve seating device comprising a housing with a cylindrically shaped outer piston, a catch piston with a cone-shaped extension, and check valves, which progressively throttles hydraulic fluid flow to slow the valve's closing velocity, reducing wear and damage by opposing the closing motion effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If hydraulic fluid is rapidly released from the lost motion system to close the valve earlier, then valve timing is improved, but valve closing velocity increases causing damaging impact

Engineering Contradiction:

Improvevalve closing timeVSAvoidvalve impact damage

Core Design Contradiction:

Loss of timeVSObject-affected harmful factors

Solution Approach 1:

A valve seating device with a seating piston and orifice is introduced as an intermediary between the hydraulic lost motion system and the valve. This device mediates the closing action by controlling fluid flow through a restricted orifice, allowing the valve to close earlier while maintaining controlled velocity and preventing damaging impact.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the flow resistance parameter by introducing a restricted orifice in the valve seating device. This orifice creates backpressure that slows the closing velocity of the valve, transforming the harmful high-velocity impact into a controlled, low-velocity seating action while maintaining the improved timing.

Inventive Principle:

Principle #35Parameter changes

2Length of moving object

If a fixed cam profile is used to provide maximum valve lift, then valve opening capability is improved, but valve timing adjustment flexibility deteriorates

Engineering Contradiction:

Improvevalve liftVSAvoidvalve timing adjustment

Core Design Contradiction:

Length of moving objectVSAdaptability or versatility

Solution Approach 1:

The patent replaces the static fixed cam profile system with a dynamic hydraulic lost motion system. The variable length device can dynamically adjust its length to provide different amounts of lost motion, enabling the valve to achieve maximum lift when needed while also allowing timing adjustments by varying the amount of motion lost, thus providing both lift capability and timing flexibility.

Inventive Principle:

Principle #15Dynamics

3Speed

If valve return springs are made stiff to enable quick valve closing, then valve closing speed is improved, but valve impact force increases causing erosion and damage

Engineering Contradiction:

Improvevalve closing speedVSAvoidvalve seat erosion

Core Design Contradiction:

SpeedVSObject-affected harmful factors

Solution Approach 1:

The valve seating device acts as an intermediary that decouples the spring force from the valve seating action. The stiff spring can maintain high closing speed, but the seating device's orifice controls the final seating velocity, preventing the spring force from directly causing impact damage to the valve and seat.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The valve seating device provides beforehand cushioning by creating controlled resistance through the orifice before the valve completes its closing motion. This progressive resistance cushions the valve approach, reducing the impact velocity and preventing erosion and damage before the valve actually seats.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 device effectively slows the engine valve's closing velocity in a progressive manner, particularly in the last millimeter of travel, thereby reducing wear and damage on both the valve and its seat, while maintaining consistent valve seating control across different engine operating conditions.

Implementation Method 1

The valve seating device may include a housing, an outer piston, an inner piston, a spring, and at least one check valve

Methodology Applied

Scientific EffectCheck valve flow control: Valve

Implementation Method 2

The inner piston may include a cone-shaped extension that selectively covers the orifice. The cone-shaped extension may progressively throttle flow through the orifice as the inner piston moves within the outer piston

Methodology Applied

Scientific EffectProgressive throttling: Pressure Gradient

Implementation Method 3

engine valves are required to open and close very quickly, and therefore the valve return springs are generally relatively stiff

Methodology Applied

Scientific EffectSpring force: Spring

Data Source

PatentEP1869294B1Valve actuation system with valve seating control

Publication Date: 2013.11.06 JACOBS VEHICLE SYSTEMS INC

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AI summary

A variable valve actuation system to actuate and control the seating velocity of an internal combustion engine valve is disclosed. The system comprises: a housing having a bore formed therein; an outer piston slidably disposed in the bore, the outer piston having an orifice formed therein; a catch piston slidably disposed in the outer piston; and an cone-shaped extension extending from the inner piston, wherein the cone-shaped extension is adapted to provide a variable flow area through the outer piston orifice to provide improved engine valve seating.