Friction Clutch Control for Driveline Shock Load Mitigation

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Solution Overview

Problem

Heavy-duty vehicles experience mechanical failures due to high shock loads during sudden stops or transitions from slipping to non-slipping events, which existing clutch control strategies fail to effectively mitigate.

Innovation Solution

A clutch control system with a friction clutch capable of transitioning between fully open, partially open, and fully closed positions, controlled by a control unit that defines operational modes including a driveline protection mode to absorb shock loads, preventing clutch slip and protecting fragile driveline components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the clutch is operated in a fully closed position to prevent clutch slip, then driveline protection is improved, but shock loads cannot be absorbed and mechanical failure risk increases

Engineering Contradiction:
Improvedriveline protectionVSAvoidshock load absorption
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The clutch control system dynamically adjusts the clutch position between fully closed and partially open states based on real-time driveline conditions. The control unit monitors wheel slip events and shock load conditions, then actuates the clutch to an intermediate position that provides both protection and shock absorption capability, resolving the contradiction between maintaining reliability and absorbing shock loads.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the clutch engagement parameter from a binary state (fully closed or fully open) to a continuous range of positions. By controlling the clutch actuator to position the clutch at specific intermediate engagement levels, the system optimizes both driveline protection and shock load absorption, allowing the torque capacity to be precisely matched to current engine torque conditions.

Inventive Principle:
Principle #35Parameter changes

2Strength

If the clutch is kept in a partially open position to absorb shock loads, then shock load absorption is improved, but clutch wear increases and lifespan decreases

Engineering Contradiction:
Improveshock load absorptionVSAvoidclutch lifespan
Core Design Contradiction:
StrengthVSDuration of action of stationary object

Solution Approach 1:

The control system proactively positions the clutch in optimal engagement states before shock load events occur. By detecting wheel slip events and driveline conditions in advance, the system pre-positions the clutch to absorb upcoming shock loads, then returns to fully closed position afterward, minimizing wear while maintaining protection capability when needed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The clutch operates in periodic cycles between fully closed (normal operation), partially open (shock absorption), and fully open (clutch disengaged) states. This periodic action allows the clutch to spend most time in the durable fully closed position while briefly entering partially open states only when shock loads are detected, optimizing both lifespan and protection.

Inventive Principle:
Principle #19Periodic action

3Reliability

If engine torque is limited to prevent shock loads, then driveline protection is improved, but vehicle productivity and power output decrease

Engineering Contradiction:
Improvedriveline protectionVSAvoidvehicle power output
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The clutch acts as an intermediary device between the engine and driveline, absorbing shock loads through controlled slippage rather than limiting engine torque. This allows the engine to maintain full power output and productivity while the clutch selectively absorbs harmful shock loads, resolving the contradiction between driveline protection and vehicle productivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 system effectively prevents mechanical damage by allowing the clutch to slip when significant shock loads occur, reducing wear on the clutch and extending its lifespan while safeguarding the driveline from damage.

Implementation Method 1

a friction clutch capable of transitioning between a fully open, a partially open, and a fully closed position

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4660475A1A clutch control system and method for mitigating driveline shock loads and preventing mechanical failure
Publication Date: 2025.12.10 VOLVO TRUCK CORP
  • EP4660475A1 patent drawingFigure 1
  • EP4660475A1 patent drawingFigure 2A~2C
  • EP4660475A1 patent drawingFigure 3

AI summary

A clutch control system for mitigating driveline shock loads in a vehicle. The clutch control system comprises: 1) A friction clutch capable of transitioning between a fully open, a partially open, and a fully closed position; 2) A control unit configured to receive vehicle data, wherein the vehicle data comprises current engine torque, and define one or more operational modes of the friction clutch, wherein the one or more operational modes comprise a driveline protection mode defined by having an operating range between the fully open position and an effectively closed position of the clutch, wherein the effectively closed position is a partially open position having a torque capacity that exceeds the current engine torque, thereby preventing clutch slip at the effectively closed position; and 3) A clutch actuator configured to operate the clutch in accordance with the one or more operational modes, including the driveline protection mode.