Friction Clutch Temperature Estimation via Component Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for estimating the temperature of motor vehicle friction clutch device elements are not precise and do not account for specific components, leading to potential overheating and malfunctions, especially in double clutch systems used in automated transmissions.
Innovation Solution
The method discretizes one-piece components into distinct elements, calculates thermal power storage and conduction, and includes thermal radiation, using a digital computer to estimate temperatures by integrating evolution and excitation matrices with correction for air temperature measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a mathematical model is used to estimate temperature based on engine torque and ambient temperature measurements, then the estimation can be performed in real-time without direct temperature sensors, but the resulting temperature estimates are not sufficiently precise and do not account for specific components
Solution Approach 1:
The patent divides one-piece components (pressure plates, friction discs, covers) into multiple discrete elements or nodes. Each element is assigned its own temperature state variable, allowing the model to capture local temperature variations and heat transfer paths within components, thereby improving estimation precision while maintaining real-time computational capability
Solution Approach 2:
The patent assigns different thermal properties (heat capacity, thermal conductivity) to different elements based on their material composition and geometric characteristics. This local differentiation allows the model to accurately represent heat storage and conduction behavior in specific components such as the peripheral annular part, central hub, and connecting parts of pressure plates
2Device complexity
If traditional thermal models are used that consider only convection and conduction, then the model structure remains simple, but the temperature estimation does not account for thermal radiation which becomes significant at elevated temperatures
Solution Approach 1:
The patent incorporates thermal radiation effects by adding radiation heat transfer terms to the energy balance equations. The radiation heat transfer coefficient is calculated based on the fourth power of absolute temperature, allowing the model to accurately represent radiative heat loss from hot components to the surrounding air, especially when temperatures exceed typical operating ranges
3Device complexity
If one-piece components are treated as single thermal nodes, then the model requires fewer state variables and is computationally simpler, but it cannot evaluate the temperature at specific points of a component
Solution Approach 1:
The patent segments pressure plates into at least two elements (peripheral annular part and central hub), friction discs into multiple elements, and covers into several elements. Each element becomes a separate thermal node with its own temperature state variable, enabling the model to evaluate temperatures at specific locations such as the friction contact surfaces and central regions
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
This approach provides more precise real-time temperature estimation, enabling effective prevention of overheating and improving clutch device reliability by accounting for specific components and heat transfer mechanisms.
Implementation Method 1
the heat produced by friction does not have time to be evacuated and the various elements of the friction clutch device, such as pressure plates or friction discs, risk heating up beyond a critical temperature
Implementation Method 2
the terms of the evolution matrix are calculated by taking into account the thermal power stored by the discretization elements as a function of their mass, the thermal power transmitted to the surrounding air and the thermal conduction between the two discretization elements
Implementation Method 3
the terms of the evolution matrix are calculated by taking into account the thermal power stored by the discretization elements as a function of their mass, the thermal power transmitted to the surrounding air
Implementation Method 4
the product of a radiation matrix and the state vector raised to the fourth power is added, in order to take into account the heat transfer by thermal radiation between each of the elements and the air contained in the bell
Data Source
Figure 1
Figure 2~4
AI summary
The invention relates to a method for real-time estimation of the temperature ({θ}) of the elements of a friction clutch device of an automobile vehicle which is intended to be implemented by a digital computer 44, comprising: - a first step (E1) of collecting values of thermal excitation variables ({U}); - a second step (E2) of calculating the thermal power (Pa, Pb) dissipated by friction; - a third step (E3) of estimating thermal state variables ({θ}) of the clutch device, characterized in that at least one monobloc component (28) is discretized into at least two contiguous distinct elements (30, 32, 34), the temperature (θ3prime, θ3bis, θ3ter) of each of said discretization elements (30, 32, 34) forming a state variable which is estimated during the third step (E3).