Drive Force Distribution Torque Coupling Overheating Estimation
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Solution Overview
Problem
Existing drive force distribution devices face challenges in suppressing overheating of heat generating components in vehicle drive force transmission systems, particularly due to the high cost and complexity of using temperature sensors for each heat generating portion.
Innovation Solution
A drive force distribution device and method that estimates the temperature of heat generating components based on rotational speed, torque transmission rate, and outside temperature, using an ECU to control the torque coupling and adjust the drive force distribution ratio to prevent overheating, eliminating the need for individual temperature sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If temperature sensors are installed in each heat generating portion to accurately detect temperatures, then overheating suppression reliability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent creates a virtual temperature model (copy of temperature information) through mathematical estimation based on easily measurable parameters like rotational speed and torque, replacing the need for physical temperature sensors in each heat generating portion. This allows the ECU to obtain temperature information indirectly through calculation rather than direct measurement.
Solution Approach 2:
The patent replaces the mechanical/physical sensor-based temperature detection system with an electronic calculation-based estimation system. Instead of using physical sensors to measure temperature directly, the system uses the ECU to calculate estimated temperatures based on operational parameters, substituting a complex physical measurement system with a simpler computational approach.
2Measurement precision
If individual temperature sensors are installed in each heat generating portion, then temperature detection precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent creates virtual temperature data through mathematical modeling, generating temperature information copies based on operational parameters rather than using physical sensors. This estimation approach provides sufficient temperature information for control purposes without the high cost of installing multiple precision temperature sensors.
Solution Approach 2:
The patent uses easily measurable parameters (rotational speed, torque) that are already available in the system rather than expensive temperature sensors. These parameter measurements are inexpensive and already part of the normal operational monitoring, eliminating the need for additional costly temperature sensing components.
3Measurement precision
If fluid temperature sensors are installed to estimate heat generating portion temperatures, then temperature estimation accuracy is improved, but device complexity increases
Solution Approach 1:
The patent creates virtual temperature information through mathematical estimation using operational parameters, replacing the need for physical fluid temperature sensors. The ECU calculates estimated temperatures based on the relationship between operational conditions and heat generation, providing temperature information without direct fluid temperature measurement.
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
Effectively suppresses overheating of heat generating components by accurately estimating temperatures and adjusting the torque transmission rate, reducing the complexity and cost of sensor installation while enhancing overheating suppression reliability.
Implementation Method 1
The coupling changes a torque transmission rate of a torque transmitted from an input of the coupling to an output of the coupling
Implementation Method 2
The torque coupling employs a friction clutch, which generates heat through frictional engagement of clutch plates
Implementation Method 3
a transfer case or a differential, which are arranged in the drive force transmission system of a vehicle, generate heat through friction caused by engagement of gears
Data Source
AI summary
An ECU estimates the temperatures of the heat generating portions provided in a drive force transmission system, or a transaxle, a rear differential, and a torque coupling, in correspondence with not only the rotational speed (the differential rotational speed) of each heat generating portion and the torque transmission rate of the torque coupling but also the outside temperature detected by an outside temperature sensor. If the estimated temperature of any of the heat generating portions exceeds a respective predetermined temperature, the ECU controls operation of the torque coupling to suppress overheating of the heat generating portion. That is, the temperature of each heat generating portion is accurately detected through a simplified structure and overheating of the heat generating portion is effectively suppressed.