Selective Reset Lost Motion Valve Train Components
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Solution Overview
Problem
Existing engine valve actuation systems struggle to efficiently transition between normal and late intake valve closing cycles, especially in space-constrained environments, and require complex external reset control components, which are costly and not adaptable to all engine configurations.
Innovation Solution
The integration of a compact rocker arm with internal hydraulic control circuits and reset components that allow for selective switching between normal and late valve closing profiles using a constant hydraulic fluid supply, eliminating the need for external reset control components and providing a compact package suitable for various engine environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If external reset control components are used to enable selective resetting between normal and late valve closing cycles, then valve actuation flexibility is improved, but device complexity and implementation cost increase
Solution Approach 1:
The patent merges the reset control functionality directly into the rocker arm by integrating a reset piston, reset spring, and hydraulic control circuit within the rocker arm body. This eliminates the need for separate external reset control components while maintaining the ability to selectively reset between normal and late valve closing cycles, thereby reducing device complexity while preserving valve actuation flexibility.
Solution Approach 2:
The rocker arm is designed to perform multiple functions: it acts as both the valve actuation mechanism and the reset control system. The integrated hydraulic control circuit within the rocker arm enables it to selectively transition between normal valve closing and late valve closing cycles, making the rocker arm a universal component that combines actuation and control functions.
2Adaptability or versatility
If external reset control components are used to provide selective resetting capability, then valve actuation adaptability is improved, but implementation cost increases
Solution Approach 1:
By combining the reset control components (reset piston, reset spring, hydraulic circuit) into the rocker arm assembly, the patent reduces the total number of parts that need to be manufactured and assembled. This integration simplifies the manufacturing process and reduces implementation costs while maintaining full adaptability for selective resetting between normal and late valve closing cycles.
3Volume of moving object
If space-constrained engine environments are considered, then packaging flexibility is improved, but the ability to accommodate external reset control components deteriorates
Solution Approach 1:
The patent nests the reset control components (reset piston, reset spring, and hydraulic control elements) inside the rocker arm body, effectively placing one mechanism within another. This nested arrangement eliminates the need for additional external space while preserving the full reset control capability, making the system suitable for space-constrained engine environments.
Solution Approach 2:
The integration of reset control functionality within the rocker arm eliminates the need for separate external components, thereby maximizing packaging flexibility in space-constrained engine environments while maintaining complete adaptability for selective valve closing control.
4Stability of the object's composition
If the intake opening profile is kept unmodified while enabling selective closing profiles, then engine performance consistency is improved, but the complexity of controlling selective closing increases
Solution Approach 1:
The patent uses hydraulic fluid as an intermediary to control the reset mechanism. The hydraulic control circuit selectively applies pressure to the reset piston, which in turn controls whether the rocker arm resets to normal valve closing or maintains late valve closing. This hydraulic mediation enables precise control of the closing profile while keeping the opening profile unmodified, managing the complexity through fluid-based actuation rather than direct mechanical control.
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
This solution enables efficient and adaptable valve actuation systems that maintain unmodified intake opening profiles while offering flexible closing profiles, improving engine performance and reducing implementation costs by integrating all dynamic reset parts within the rocker arm.
Implementation Method 1
a reset piston in fluid communication with the lost motion component and in communication with a constant fluid supply
Data Source
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AI summary
Systems and related methods include a rocker arm having integrated components, including a lost motion actuator piston and components for resetting the lost motion actuator piston to provide normal valve closing or late valve closing. Selective reset is facilitated by a reset piston and a blocking piston disposed in a hydraulic circuit including a reset passage. In a non-resetting mode of operation, the blocking piston may block oil flow within the reset passage, regardless of the position of the reset piston, which facilitates late valve closing. An alternative embodiment includes a blocking sleeve disposed concentrically relative to the reset piston.