Variable Valve Rocker Arm Switching Mechanism
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Solution Overview
Problem
Conventional variable valve apparatuses face issues with power consumption and implementability, as they require continuous solenoid coil energization to maintain rocker arm contact, leading to increased fuel consumption and complexity due to temperature-related magnetism degradation in permanent magnet-based systems.
Innovation Solution
A variable valve apparatus with a connecting pin biased away from rocker arms, driven by an actuator and held in position by a state holding mechanism, eliminating the need for continuous power and simplifying control, and incorporating a knock rotating ratchet mechanism or rotary type electromagnetic solenoid with a biasing device and clutch for efficient switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If continuous solenoid coil energization is used to maintain rocker arm contact, then reliable rocker arm switching is achieved, but power consumption increases leading to higher fuel consumption
Solution Approach 1:
The solenoid coil is energized only periodically during switching transitions rather than continuously. The control unit activates the solenoid only when valve lift amount needs to be changed, allowing the rocker arm to switch between first and second rockers. After switching is complete, the solenoid is de-energized and the position is maintained by the mechanical structure, dramatically reducing power consumption while maintaining reliable switching.
Solution Approach 2:
The system uses the spring mechanism and gravitational force to maintain rocker arm positions without continuous energy input. Once the solenoid initiates a position change, the mechanical components (springs, linkages) self-maintain the new position without requiring ongoing electrical power, making the system self-sustaining after the initial switching action.
2Use of energy by moving object
If permanent magnet is used to maintain rocker arm contact without power consumption, then power consumption is reduced, but magnetism degrades at high temperatures reducing reliability
Solution Approach 1:
The patent replaces the permanent magnet-based magnetic field system with a mechanical spring-based system. Instead of using magnetic attraction to maintain rocker arm contact, the invention uses spring force and mechanical linkages to hold the rocker arms in their respective positions. This mechanical substitution eliminates temperature-dependent magnetism degradation while maintaining zero power consumption for position maintenance.
3Reliability
If heat insulation measures are provided to protect permanent magnet, then magnetism stability is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts and removes the permanent magnet from the system entirely, replacing it with a thermal-stable mechanical spring mechanism. By taking out the temperature-sensitive component (permanent magnet) and substituting it with a temperature-insensitive mechanical system, the need for heat insulation measures is completely eliminated, simplifying the overall device structure while maintaining reliability in high-temperature engine environments.
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 solution achieves zero power consumption for maintaining switched rocker arm states and eliminates the need for heat insulation, enhancing implementability and reducing fuel consumption by simplifying control and operation.
Implementation Method 1
The spring biases (i.e. applies a force to) the actuator plate to an upper projecting position
Implementation Method 2
the solenoid coil magnetically attracts the armature to move the actuator plate to a lower position
Implementation Method 3
the state of the actuating piece moved backward is maintained by electromagnetic attraction of the permanent magnet
Data Source
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AI summary
With a variable valve apparatus of the present invention, when an actuator 41 is operated to switch between a rocker arm 19 for low speed and a rocker arm 21 for high speed, an actuating piece 47 is moved to a different position, whereby a connecting pin 37 is moved forward to the rocker arm 21 for high speed. At this time, even if the actuator 41 is put out of operation, a state holding mechanism 43 holds each position of the connecting pin 37. Therefore, there occurs no power consumption for maintaining the state where switching is made to the rocker arm 21 for high speed, and also measures against heat are unnecessary. This realizes a variable valve apparatus having very high implementability.