Variable Compression Piston Rod Position Detection
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Solution Overview
Problem
Existing engine systems face challenges in accurately adjusting the compression ratio due to the lack of precise piston rod position detection, leading to inefficiencies in controlling the compression ratio.
Innovation Solution
A variable compression device equipped with a detection unit that includes a rod with a magnetic member and a sensor to non-contactedly detect the piston rod's position, transmitting this information to a controller to accurately adjust the piston rod's position and boost the working fluid accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a compression ratio adjustment mechanism is provided to change the piston rod position, then the compression ratio can be adjusted to cope with different fuel types, but the position of the piston rod cannot be accurately ascertained leading to difficult compression ratio adjustment
Solution Approach 1:
The patent replaces mechanical position detection methods with a magnetic detection system. A magnetic member is attached to the piston rod, and a magnetic sensor (such as a Hall sensor or magnetoresistive sensor) detects the position of the piston rod by sensing the magnetic field changes. This substitution of mechanical detection with magnetic field-based detection enables accurate, non-contact measurement of the piston rod position, thereby resolving the contradiction between compression ratio adaptability and position measurement precision.
Solution Approach 2:
The patent introduces a magnetic member as an intermediary element attached to the piston rod. This magnetic member serves as a mediator between the moving piston rod and the stationary magnetic sensor. The magnetic member carries magnetic information that the sensor can detect without direct mechanical contact, enabling precise position detection while maintaining the mechanical movement of the piston rod for compression ratio adjustment.
2Device complexity
If the piston rod position is adjusted without accurate detection, then the system structure remains simple, but the compression ratio adjustment accuracy deteriorates
Solution Approach 1:
The patent replaces complex mechanical position sensing mechanisms (such as encoders or potentiometers that require direct mechanical coupling) with a magnetic detection system. The magnetic sensor can detect position through non-contact means, significantly simplifying the mechanical structure while improving position detection accuracy and consequently compression ratio adjustment precision.
Solution Approach 2:
The magnetic member attached to the piston rod acts as an intermediary that carries position information in a form that can be detected by the magnetic sensor. This intermediary approach allows the system to achieve high measurement precision without complex mechanical linkages between the piston rod and the detection device.
3Ease of operation
If the boosting mechanism is driven frequently without accurate position information, then the piston rod can be moved to the target position, but energy consumption increases and the boosting mechanism wears out faster
Solution Approach 1:
The patent implements a feedback control system where the magnetic sensor continuously detects the actual position of the piston rod and feeds this information back to the control device. The control device compares the detected position with the target position and only activates the boosting mechanism when necessary to correct the position. This feedback mechanism prevents unnecessary boosting mechanism activation, reducing energy consumption and wear while maintaining ease of position control.
Solution Approach 2:
The patent employs periodic position detection using the magnetic sensor rather than continuous boosting mechanism operation. The system checks the piston rod position at appropriate intervals and only activates the boosting mechanism when the detected position deviates from the target position, converting continuous energy-intensive operation into periodic, demand-driven action.
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 precise monitoring and adjustment of the piston rod's position, reducing the number of times the boosting mechanism is driven and ensuring accurate compression ratio adjustments, thereby enhancing engine efficiency.
Implementation Method 1
the sensor portion is configured to detect movement of the rod in a non-contact manner
Data Source
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AI summary
A variable compression device includes a piston rod (6), a fluid chamber (R3) which is configured to move the piston rod in a direction in which a compression ratio is increased by supplying a boosted working fluid, a boosting mechanism (8) which is configured to boost the working fluid and supplies the boosted working fluid to the fluid chamber, a detection unit (400) of which at least a portion is disposed in the piston rod and which detects displacement of a position of the piston rod and outputs a signal including positional information of the piston rod, and a controller (300) which is configured to control the boosting mechanism on the basis of the positional information.