Digital Clutch Reverse Shifting Without Hill-Hold Release Delay
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Solution Overview
Problem
Traditional transmissions in electric vehicles are inefficient due to energy waste in hydraulic clutches, which is not suitable for battery-powered vehicles, and digital clutches require a hill-hold state for shifting, complicating the process of shifting into reverse.
Innovation Solution
A method for shifting a transmission into reverse using a clutch system with a pocket plate, notch plate, and directional struts actuated by solenoids, where the second actuator is deactivated, and the first actuator is activated to release the second strut from engagement, allowing the transmission to enter the reverse state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hydraulic clutches are used in traditional transmissions, then gear changing is achieved, but energy waste is extreme and thermal energy is dissipated into the atmosphere
Solution Approach 1:
The patent replaces the hydraulic clutch system with a digital clutch system that uses electric actuators (solenoids) to directly engage and disengage clutch plates. This substitution eliminates the hydraulic fluid circulation pump and associated energy losses, achieving gear changing while dramatically reducing energy waste and thermal dissipation.
2Adaptability or versatility
If hydraulic clutches are used, then gear ratios are changed, but constant pressure is required to remain engaged which further expends energy
Solution Approach 1:
The patent replaces the hydraulic pressure system with an electric actuator system. The solenoid actuators use electrical energy only during engagement and disengagement events, rather than requiring continuous hydraulic pressure to maintain gear engagement. This eliminates the constant energy expenditure associated with maintaining hydraulic pressure while preserving full gear ratio control capability.
3Use of energy by moving object
If digital clutches are used, then energy consumption is reduced, but a hill hold state is required before shifting into reverse
Solution Approach 1:
The patent implements a control system that automatically manages the hill-hold state transition. Before shifting into reverse, the control system preemptively deactivates the hill-hold engagement by retracting the second strut, ensuring the transmission is ready for reverse engagement without requiring manual driver intervention or complex driver awareness of the hill-hold state.
Solution Approach 2:
The patent employs a control system that monitors transmission state and automatically manages the sequencing of actuator operations. The control system receives a reverse command and autonomously coordinates the deactivation of the second actuator followed by the activation of the first actuator, providing feedback-based automation that simplifies the shifting operation while maintaining energy efficiency.
4Loss of energy
If digital clutches are used, then energy is not consumed once in desired gear state, but shifting process requires recognition of hill-hold state
Solution Approach 1:
The patent implements a control system that automatically monitors transmission state and manages the sequencing of actuator operations during shifting. The control system receives gear shift commands and autonomously coordinates the deactivation of hill-hold actuators followed by engagement of reverse actuators, eliminating the need for driver recognition of hill-hold states while maintaining the energy efficiency of digital clutches.
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 method reduces energy consumption and eliminates the need for a hill-hold state, enabling efficient shifting into reverse while minimizing energy loss and operational complexity.
Implementation Method 1
A first rotational torque is applied to the notch plate in a direction allowing the notch plate to abut the at least one first strut
Implementation Method 2
A second rotational torque is applied to the notch plate opposite the first rotational torque to rotate the notch plate out of engagement with the at least one first strut
Data Source
AI summary
A transmission is shifted into a reverse state. The transmission includes a clutch. The clutch includes a pocket plate, a notch plate, a first strut housed within a pocket of the pocket plate, and a second strut housed within another pocket. A command is received to shift the transmission to reverse. It is then determined whether the at least one second strut has retracted into the pocket plate. If it remains extended, the first actuator is activated. A first rotational torque is applied to the notch plate in a direction allowing the notch plate to abut the first strut. By doing so, the second strut is released from abutting engagement with the notch plate. A second rotational torque is applied to the notch plate opposite the first rotational torque to rotate the notch plate out of engagement with the first strut, resulting in the transmission entering the reverse state.