Shift Controller Motor Duty Adjustment for Transmission Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In sequential type multispeed transmissions, the variation in lubricating oil temperature affects the revolution speed of the shift drum, leading to increased shifting time and noise during clutch engagement, as existing technologies fail to efficiently adjust motor output based on oil temperature variations.
Innovation Solution
A shift controller that uses an electric motor, an oil temperature sensor, and a controller to adjust the motor duty based on oil temperature, with predetermined time intervals to optimize the revolution speed of the shift drum, ensuring timely engagement and release of the dog clutch, thereby reducing noise and shifting time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the electric motor operates at normal speed regardless of oil temperature, then the shifting response is fast, but the noise increases and shift quality deteriorates at high temperatures
Solution Approach 1:
The patent applies dynamics by making the motor speed variable rather than fixed. The control unit dynamically adjusts the motor duty cycle based on detected oil temperature, allowing the motor speed to adapt to changing thermal conditions. This resolves the contradiction by enabling fast shifting at normal temperatures while reducing speed at high temperatures to minimize noise and improve shift quality.
Solution Approach 2:
The patent changes the operational parameters of the electric motor based on oil temperature. Specifically, the duty cycle parameter is adjusted according to temperature thresholds: normal duty at low temperatures for fast response, and reduced duty at high temperatures for noise reduction. This parameter adaptation resolves the technical contradiction between speed and noise.
2Object-affected harmful factors
If the electric motor speed is reduced to lower noise, then the shift quality improves, but the shifting time increases and response deteriorates
Solution Approach 1:
The patent changes motor operational parameters selectively based on temperature conditions. Instead of always reducing speed for noise reduction, the system uses normal motor duty at low temperatures for fast shifting, and only reduces duty when oil temperature exceeds the threshold. This conditional parameter change resolves the contradiction by applying noise-reduction speed only when necessary.
Solution Approach 2:
The patent implements different motor operation modes (normal duty and reduced duty) that are selectively activated based on temperature. This creates adaptive behavior where the system copies appropriate operational characteristics from different modes to match environmental conditions, resolving the time-quality trade-off.
3Object-affected harmful factors
If the motor duty is adjusted based on oil temperature throughout the entire shift process, then noise is reduced, but the dog clutch engagement becomes difficult at high temperatures
Solution Approach 1:
The patent segments the shift process into distinct phases: the engagement phase (first predetermined time) and the subsequent phase. During engagement, normal motor duty is maintained regardless of temperature to ensure reliable dog clutch engagement. After engagement, reduced duty is applied to minimize noise. This temporal segmentation resolves the contradiction between engagement reliability and noise reduction.
Solution Approach 2:
The patent applies preliminary action by maintaining normal motor duty during the critical engagement phase before temperature-based reduction is applied. This preliminary normal-speed action ensures reliable clutch engagement, and only after this critical phase is complete does the system reduce speed for noise reduction, preventing engagement difficulties.
Data Source
AI summary
A shift controller for a motor vehicle includes an electric motor configured to rotate a shift drum associated with a transmission. An oil temperature sensor is configured to detect temperature of lubricating oil for the transmission. A controller is configured to control the electric motor. The controller controls the electric motor to operate in a preset first motor duty until a first predetermined time elapses after operation of the electric motor is started when the shift drum is turned from a first predetermined position to a second predetermined position. The controller is also configured to operate the electric motor in a second motor duty calculated based upon oil temperature after the first predetermined time elapses.