Hybrid Vehicle Control Device for Reverse Drive Torque
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Solution Overview
Problem
Existing hybrid vehicle configurations struggle to achieve high drive torque during reverse travel while preventing excessive torque from acting on engagement mechanisms, leading to potential durability issues due to the inability to inhibit forward rotation of the engine and carrier during forward travel.
Innovation Solution
A control device for a hybrid vehicle that engages an engagement mechanism, such as a selectable one-way clutch, to stop engine rotation during reverse travel, allowing both motors to function as drive power sources and disengaging it during forward travel to prevent excessive torque on stopped components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the engagement mechanism is engaged to stop engine rotation during reverse travel, then drive torque is increased by utilizing both motors, but excessive torque acts on the engagement mechanism causing durability issues
Solution Approach 1:
The patent applies dynamics by making the engagement mechanism's state changeable between engaged and disengaged positions based on operating conditions. The control device dynamically switches the engagement mechanism's state: engaged during reverse travel to enable two-motor operation and increase drive torque, and disengaged during forward travel to prevent excessive torque accumulation. This dynamic adjustment resolves the contradiction between maximizing power output and ensuring component durability.
2Adaptability or versatility
If the one-way clutch is configured to inhibit negative rotation during forward travel, then it cannot inhibit forward rotation during reverse travel, preventing two-motor reverse travel
Solution Approach 1:
The patent applies inversion by reversing the engagement mechanism's function based on travel direction. Instead of the one-way clutch being fixed to inhibit only negative rotation, the control device inverts its operational state: during reverse travel, it engages to inhibit forward rotation of the engine/carrier, enabling two-motor operation. This inversion of the engagement state according to travel direction enables the previously impossible two-motor reverse travel capability.
3Power
If the brake is engaged during forward travel to stop engine rotation, then durability is reduced due to reverse output acting on the brake from road conditions or driver operations
Solution Approach 1:
The patent applies the intermediary principle by introducing a controllable engagement mechanism that acts as a mediator between the engine and the brake system. Instead of directly engaging the brake to stop engine rotation (which causes durability issues when reverse output acts on it), the engagement mechanism serves as an intermediate device that can be selectively engaged or disengaged. During forward travel, it remains disengaged, allowing the engine to rotate freely and preventing reverse output from acting on the brake, thus protecting brake durability while still enabling rotation control when needed.
Data Source
AI summary
A hybrid vehicle includes: an engine; a first motor; an output member; a differential mechanism, the engine, the first motor, and the output member being coupled via the differential mechanism; a second motor configured to apply torque to the output member; and an engagement mechanism configured to stop rotation of an output shaft of the engine or rotation of a specified rotational member that is coupled to the output shaft of the engine. An electronic control unit is configured to (i) engage the engagement mechanism when the hybrid vehicle travels reversely by drive power of the second motor or drive power of the first motor and the second motor, and (ii) disengage the engagement mechanism when the hybrid vehicle travels forward by the drive power of the second motor or the drive power of the first motor and the second motor.