Deactivatable Rocker Arm for Cylinder Deactivation

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Solution Overview

Problem

Stamped sheet material rocker arms, while offering advantages in packaging and fuel economy, pose challenges for implementing variable valve actuation techniques like cylinder deactivation due to their compact size.

Innovation Solution

A valvetrain assembly with a deactivatable rocker arm and pushrod system that uses castellation assemblies and rotary or linear actuators to transfer valve lift profiles, allowing for efficient cylinder deactivation and other variable valve actuation techniques by integrating multiple components in a compact carrier configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If stamped sheet material rocker arms are used, then packaging is tighter and fuel economy is improved, but implementing variable valve actuation techniques becomes difficult

Engineering Contradiction:

Improvefuel economyVSAvoidcapability for variable valve actuation

Core Design Contradiction:

Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The rocker arm is divided into two separate arms: a valve side arm that receives pushrod input and a deactivating arm that controls valve deactivation. This segmentation allows independent control functions to be integrated into the compact stamped sheet material rocker arm assembly, enabling variable valve actuation while maintaining fuel economy benefits

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The latch pin mechanism is nested within the deactivating arm, and the actuator is integrated into the carrier opening. This nesting approach allows multiple functional components to be contained within the compact rocker arm assembly, providing variable valve actuation capability without increasing overall packaging volume

Inventive Principle:

Principle #7Nested doll (Nesting)

2Weight of moving object

If stamped sheet material rocker arms are used, then weight is reduced and fuel economy is improved, but device complexity increases for cylinder deactivation

Engineering Contradiction:

Improverocker arm weightVSAvoidcomplexity for cylinder deactivation

Core Design Contradiction:

Weight of moving objectVSDevice complexity

Solution Approach 1:

The latch pin mechanism, deactivating arm, and actuator are merged into an integrated assembly that works together as a unified system. This merging reduces the number of separate components needed for cylinder deactivation, thereby reducing overall device complexity while maintaining the weight benefits of stamped sheet material rocker arms

Inventive Principle:

Principle #5Merging (Combining)

3Volume of moving object

If compact rocker arm design is used, then packaging is improved, but response time for valve actuation decreases

Engineering Contradiction:

Improverocker arm volumeVSAvoidvalve actuation response time

Core Design Contradiction:

Volume of moving objectVSLoss of time

Solution Approach 1:

The hydraulic actuation system is replaced with an electro-mechanical actuator that directly drives the latch pin mechanism. This substitution eliminates hydraulic fluid delays and provides faster, more direct control of the valve deactivation process, improving response time while maintaining the compact rocker arm design

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS12025036B2Cylinder deactivation mechanisms for pushrod valve train systems and rocker arms

Publication Date: 2024.07.02 EATON INTELLIGENT POWER LTD

AI summary

A valvetrain assembly comprises a deactivatable rocker arm where a pushrod is configured to transfer a valve lift profile through to a valve end to a valve or valve bridge. A castellation assembly in a carrier and alternative two-piece rocker arm assemblies with rotary or linear actuators are shown for deactivating the transfer of the valve lift profile.