Clutch-Servo Piston Position Detection for Gearbox Protection
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Solution Overview
Problem
The existing clutch-servo systems in vehicles often fail to ensure complete disengagement of the clutch due to air bubbles in hydraulic circuits or mechanical wear, leading to potential damage to the gearbox when the clutch is not fully open, especially when the clutch pedal is not pressed fully or when the servo-actuated gear shift is activated.
Innovation Solution
Incorporating sensors within the clutch-servo actuator to detect the position of the pneumatic piston and prevent activation of the servo-actuated gear shift unless the clutch is at least 70%-80% open, and installing a sensor at the master-cylinder to detect pedal position and initiate air venting if necessary, ensuring the clutch is fully disengaged before allowing gear shift operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the clutch pedal is not pressed completely, then the driver can operate the vehicle more comfortably, but the clutch does not disengage completely causing potential gearbox damage
Solution Approach 1:
A sensor detects the actual position of the clutch piston and provides feedback to the control unit. The control unit compares the detected position with the required disengagement position and adjusts the clutch actuation accordingly, ensuring complete disengagement while allowing comfortable pedal operation.
Solution Approach 2:
The mechanical connection between the clutch pedal and clutch actuation is replaced with an electronic control system. The sensor and control unit electronically monitor and adjust the clutch position, eliminating the direct mechanical linkage and enabling precise control independent of pedal pressure.
2Ease of operation
If the hydraulic circuit contains air bubbles, then the system becomes less reliable, but the clutch pedal can still be pressed completely
Solution Approach 1:
The sensor provides real-time feedback on the clutch piston position, allowing the control unit to detect when air bubbles prevent complete disengagement. The system can then indicate the presence of air or adjust actuation to compensate, maintaining reliability despite air contamination in the hydraulic circuit.
3Productivity
If the servo-actuated gear shift is activated while the clutch is not fully open, then gear shifting can be performed, but internal gearbox components will be damaged
Solution Approach 1:
The control unit prevents the servo-actuated gear shift from operating by blocking its activation signal until the sensor confirms the clutch piston has reached the required disengagement position. This preliminary prevention avoids the harmful action of gear shifting with an engaged clutch, protecting gearbox components.
Solution Approach 2:
The sensor feedback on clutch piston position is used by the control unit to enable or disable the gear shift function. The gear shift can only be activated when the feedback indicates the clutch is sufficiently disengaged, preventing damage to synchronizers and other internal components.
4Reliability
If a sensor is added to detect clutch piston position, then gearbox damage is prevented, but the system complexity increases
Solution Approach 1:
A magnetic field intermediary is used instead of direct mechanical or electrical connections. The magnetic sensor detects the piston position through magnetic field interaction, eliminating the need for complex mechanical linkages or electrical contacts within the hydraulic system, thus minimizing added complexity.
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
Prevents gearbox damage by ensuring the clutch is fully disengaged before allowing gear shift operations, thereby protecting internal components from excessive forces and preventing air entrapment issues.
Implementation Method 1
The hydraulic circuit comprises a hydraulic piston on the master-cylinder, hydraulically connected with the clutch-servo, so the oil pressure is transferred to the piston of the clutch-servo
Implementation Method 2
The clutch-servo is also connected to a pneumatic circuit in order to exploit the pneumatic energy and to minimize the necessary human force to actuate the clutch. A piston operates the clutch by using both energy types, namely compressed air and pressure of hydraulic oil
Data Source
AI summary
The present invention provides for a method and apparatus for preventing damaging of a gear box of a vehicle provided with a servo-actuated clutch system and a servo-actuated gear shift system, the servo-actuated clutch comprising a clutch-servo housing a pneumatic piston, movable between a first and a second positions corresponding to an open and a closed system of the clutch. The functioning of servo-actuated gear shift system is enabled when the pneumatic piston position exceeds, toward said disengagement state, a third predefined position.