Valve Timing Control Device Torque Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional valve timing control devices for internal combustion engines face complexity and size issues due to the use of electromagnetic brake devices, leading to torque imbalance and potential phase shifts during engine stop and start states, which affect start performance.
Innovation Solution
A valve timing control device utilizing an electric motor to generate magnetic retaining torque, with a control unit that balances motor torque with cam torque after engine stop, ensuring torque balance and preventing phase shifts by gradually reducing motor torque and applying braking forces, thus simplifying the device structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an electromagnetic brake device is added to control engine phase during stop state, then the engine phase can be retained in start phase, but the device complexity and size increase
Solution Approach 1:
The electric motor is designed to perform multiple functions: generating motor torque during engine operation for valve timing control, and generating magnetic retaining torque during engine stop state for phase retention. This eliminates the need for a separate electromagnetic brake device while maintaining start performance reliability
Solution Approach 2:
The patent combines the electromagnetic brake device functionality with the electric motor by utilizing the magnetic retaining torque generated in the motor shaft when power is removed. This merges two previously separate components into one, reducing device complexity and size
2Stability of the object's composition
If an electromagnetic brake device is used to balance torque during stop state, then engine phase can be maintained, but the device size and complexity increase
Solution Approach 1:
The electric motor serves dual purposes: controlling engine phase during operation through motor torque and maintaining engine phase during stop state through magnetic retaining torque. This eliminates the need for additional electromagnetic brake devices while preserving phase stability
Solution Approach 2:
The electric motor utilizes its own magnetic field and cogging torque characteristics to generate magnetic retaining torque during the stop state, eliminating the need for external electromagnetic brake devices. The motor essentially serves itself for both operation and retention functions
3Device complexity
If magnetic retaining torque is used without balancing motor torque, then device structure is simplified, but torque imbalance causes phase shifts
Solution Approach 1:
Before completely removing power to the electric motor, the control unit first balances the motor torque with the magnetic retaining torque and cam torque. This preliminary balancing action prevents torque imbalance and subsequent phase shifts, ensuring engine phase stability when the device structure is simplified
Solution Approach 2:
The control unit monitors the torque balance between motor torque, magnetic retaining torque, and cam torque, and adjusts the power supply to the electric motor accordingly. This feedback control ensures that phase stability is maintained even without additional electromagnetic brake devices
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 ensures reliable start performance by maintaining the engine phase and preventing rapid torque changes, reducing the complexity and size of the control device while enhancing the stability of the engine phase during stop and start states.
Implementation Method 1
an electric motor for generating magnetic retaining torque and motor torque in a motor shaft by supplying power thereto
Implementation Method 2
by generating a magnetic retaining torque such as cogging torque in a motor shaft even when power is removed due to stopping of the internal combustion engine
Implementation Method 3
balancing the motor torque with the magnetic retaining torque and the cam torque even after the internal combustion engine is stopped
Data Source
AI summary
A valve timing control device is provided with an electric motor (4) generating a magnetic retaining torque (Th) and a motor torque (Tm) in a motor shaft (102) based on a power supply. A power supply control system (6) controls the motor torque (Tm) by controlling the power supply supplied to the electric motor (4). A phase control mechanism (8) transmits a cam torque (Tca) that can alternate between a positive and a negative direction in response to rotation of a cam shaft, to the motor shaft (102) and controls a relative phase between the crank shaft and the cam shaft in accordance with a torque balance in the motor shaft (102). The power supply control system (6) eliminates the motor torque (Tm) that is balanced with the magnetic retaining torque (Th) and the cam torque (Tca) after a stop of the internal combustion engine (S105).