Hydraulic Rolling Cylinder Deactivation via Poppet Valve Operator
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Solution Overview
Problem
Existing cam actuation systems for internal combustion engines, such as those described in U.S. Pat. No. 8,020,526, face issues with precise timing of solenoid valves and indirect actuation of gas-exchange valves, leading to potential engine performance problems and increased risk of valve degradation.
Innovation Solution
A hydraulic rolling cylinder deactivation system using a poppet valve operator with a rocker arm and hydraulically operated pivot ball, directly coupling to a cam lobe, and a solenoid valve with an accumulator, allowing for direct actuation of intake and exhaust valves with reduced risk of leakage and increased packaging efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a hydraulic variable valve train system is used to vary control times and lifting strokes of gas-exchange valves, then variable valve lift and timing control is achieved, but the system requires a fast-acting solenoid valve precisely timed to crankshaft rotation which increases device complexity and timing precision requirements
Solution Approach 1:
The patent replaces the complex hydraulic variable valve train system with a mechanical cam actuation system. The cam profile directly determines valve lift and timing characteristics, eliminating the need for fast-acting solenoid valves and complex hydraulic timing mechanisms. This mechanical approach simplifies the system while maintaining variable valve control capabilities through cam profile switching.
Solution Approach 2:
The patent extracts and removes the hydraulic variable valve train components (solenoid valves, hydraulic passages, accumulators) from the valve actuation system. By eliminating these complex components, the system achieves variable valve control through simpler mechanical means, specifically through cam profile switching and direct mechanical actuation.
2Adaptability or versatility
If indirect actuation of gas-exchange valves via pump tappet and slave piston is used, then variable valve control is achieved, but the indirect actuation creates higher risk for valve degradation
Solution Approach 1:
The patent removes the intermediate components (pump tappet, slave piston, hydraulic passages) from the valve actuation path. The cam lobe now directly actuates the valve through a simplified mechanical connection, eliminating the indirect actuation chain that caused wear and degradation issues in the hydraulic system.
Solution Approach 2:
The patent replaces the hydraulic actuation mechanism with a direct mechanical cam-follower system. This substitution eliminates the fluid pressure transmission and multiple mechanical interfaces that caused wear, providing more reliable direct actuation while maintaining variable valve control through cam profile switching.
3Area of stationary object
If multiple poppet valves are controlled with a single control system comprising accumulator and solenoid valve, then packaging space is increased, but the solenoid valve must operate at higher speed which increases timing precision requirements
Solution Approach 1:
The patent combines multiple valve control functions into a single camshaft with multiple cam lobes, where each cam lobe controls a specific valve. This merging of control functions into a unified mechanical system eliminates the need for multiple solenoid valves and accumulators, saving packaging space while avoiding high-speed solenoid operation requirements.
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 system improves engine performance by enabling precise control of valve timing and lift, reduces valve degradation, and enhances fuel efficiency by allowing for selective deactivation of cylinders during low-load conditions, thereby increasing fuel economy.
Implementation Method 1
the piston may be selectively rigidly or flexibly held in place by hydraulic fluid provided by an external system such as an engine oil pump
Implementation Method 2
With a solenoid valve and accumulator, when valve deactivation is desired, the solenoid valve may be operated at a slower speed than required for the hydraulic valve
Implementation Method 3
With a solenoid valve and accumulator, when valve deactivation is desired
Implementation Method 4
The rocker arm may directly couple to both a cam lobe of a camshaft and a hydraulically operated pivot ball
Data Source
AI summary
Systems and methods are provided for a poppet valve operator that may be implemented in a hydraulic rolling cylinder deactivation system of a vehicle, wherein a hydraulically operated pivot ball selectively engages a pivot pocket of a rocker arm. Simple and reliable deactivation systems are needed that can fit into limited packaging space while including fewer moving mechanical components that are susceptible to wear and damage. The proposed systems and methods involve selectively pressurizing hydraulic fluid to rigidly or flexibly hold a piston of the poppet valve operator in place in order to open or close a gas exchange valve.