Hybrid Vehicle Drive Control Device Torque Management
Solution Overview
Problem
In hybrid vehicle drive apparatuses, the first electric motor must bear a significant reaction torque, leading to the need for a larger motor size, which complicates installation and can degrade durability, making it difficult to simultaneously prevent large-sizing and maintain durability.
Innovation Solution
A control device that includes a differential state switching device and an input torque limit mechanism, allowing the vehicle drive apparatus to switch between continuously variable and step-variable shifting states, limiting input torque to prevent excessive reaction torque on the first electric motor, thereby maintaining compactness and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the first electric motor is made larger to bear the reaction torque against engine torque, then the reaction torque capacity is improved, but the installation complexity and durability are worsened
Solution Approach 1:
The patent changes the operational parameters of the first electric motor by switching between two distinct operational states: a continuously variable shifting state where the motor bears reaction torque, and a shifting state where the motor does not bear reaction torque. This parameter switching allows the motor to operate within acceptable torque limits while maintaining the necessary reaction torque capacity when needed.
Solution Approach 2:
The patent introduces dynamic switching capability to the first electric motor system, allowing it to transition between different operational modes based on vehicle conditions. The differential state switching device dynamically adjusts whether the motor bears reaction torque, transforming a static sizing problem into a dynamic operational solution.
2Force
If the first electric motor is made larger to bear the reaction torque against engine torque, then the reaction torque capacity is improved, but the motor size and durability are worsened
Solution Approach 1:
The patent applies parameter changes by controlling the first electric motor to operate in two distinct states. In the shifting state, the motor does not bear reaction torque, reducing stress and improving durability. In the continuously variable shifting state, the motor bears reaction torque when necessary. This parameter switching resolves the contradiction between torque capacity and durability.
Solution Approach 2:
The patent implements periodic switching between operational states of the first electric motor. The motor alternates between bearing and not bearing reaction torque based on vehicle operating conditions, creating a periodic action pattern that prevents continuous high-stress operation and thereby maintains durability while preserving torque capacity when needed.
3Loss of energy
If the vehicle operates in continuously variable shifting state, then fuel efficiency is improved, but the first electric motor bears excessive reaction torque
Solution Approach 1:
The patent introduces dynamic state switching to resolve the contradiction between fuel efficiency and reaction torque burden. The system dynamically transitions between continuously variable shifting state (low conversion loss) and shifting state (low reaction torque), allowing optimal operation under varying vehicle conditions rather than being locked in a single state.
Solution Approach 2:
The patent changes the operational parameter of the transmission system by switching between two distinct shifting states. This parameter change allows the system to avoid the condition where both low conversion loss and acceptable reaction torque must simultaneously occur, instead selecting the appropriate state based on which parameter is prioritized at any given moment.
Data Source
AI summary
An engaging device (a switching clutch C0 or a switching brake B0) switches a shifting mechanism 10 between a continuously variable shifting state and a step-variable shifting state. In particular. The step-variable shifting state is set in a high speed running, because a first electric motor M1 need not bear a reaction torque against an input torque TINS inputted into a differential portion 11, the first electric motor M1 is prevented from being large-sized and suppressed in durability lowering. Even when switching to the step-variable shifting state is unable, the input torque TINS against which the first electric motor M1 should bear the reaction torque, is limited by an input torque control means 86, and the first electric motor M1 is prevented from being large-sized and suppressed in durability lowering.