Hybrid EV Clutch Engagement During Catalyst Warming
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Solution Overview
Problem
Hybrid electric vehicles without a starter motor or with an anomalous starter motor cannot apply a suitable load to the engine when warming the catalyst, leading to rapid engine speed increase during catalyst warming.
Innovation Solution
A hybrid electric vehicle controller that includes first processing circuitry to execute a catalyst warming process and second processing circuitry to control the clutch and motor generator, requesting the prohibition of clutch disengagement during catalyst warming to maintain engine load and prevent rapid speed increase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the clutch is disengaged during catalyst warming, then the motor generator can operate independently, but the engine speed increases rapidly due to lack of load
Solution Approach 1:
The controller acts as an intermediary between the catalyst warming system and the clutch control system. It monitors the catalyst warming state and automatically adjusts clutch engagement accordingly, preventing rapid engine speed increases while maintaining independent motor generator operation capability.
Solution Approach 2:
The system uses its own components (clutch and motor generator) to regulate engine speed during catalyst warming. By controlling clutch engagement based on catalyst temperature feedback, the system self-regulates without requiring external intervention or additional loading devices.
2Device complexity
If the starter motor is not present or anomalous, then the vehicle structure is simpler, but the engine cannot maintain proper load during catalyst warming
Solution Approach 1:
The motor generator serves multiple functions: it acts as a starter motor during engine starting and as a load-regulating device during catalyst warming. This multi-functionality eliminates the need for a separate starter motor while maintaining reliable engine load control throughout different operating phases.
Solution Approach 2:
The functions of the starter motor and the motor generator are merged into a single device. The motor generator can operate in different modes (motoring for starting, generating for load control) depending on the operational requirements, simplifying the overall vehicle structure while maintaining reliability.
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
The solution effectively prevents rapid engine speed increase during catalyst warming by maintaining engine load through clutch engagement and motor generator assistance, ensuring efficient catalyst warming in hybrid electric vehicles.
Implementation Method 1
a catalyst warming process that warms the catalyst
Implementation Method 2
a motor generator, a clutch arranged between the crankshaft and the motor generator
Data Source
AI summary
A controller for a hybrid electric vehicle. The hybrid electric vehicle includes an engine, a motor generator, a clutch arranged between a crankshaft and the motor generator, and a catalyst arranged in an exhaust passage. The controller includes first processing circuitry that executes a catalyst warming process that warms the catalyst under a situation in which the hybrid electric vehicle is at a standstill and second processing circuitry configured to control the clutch and the motor generator. The first processing circuitry requests the second processing circuitry to prohibit disengagement of the clutch when the catalyst warming process is executed.