Hydraulic Clutch Current Profiling for Fast, Low-Shock Engagement
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Solution Overview
Problem
Existing clutch systems experience significant shocks and prolonged engagement times due to varying hydraulic pressures, leading to inconsistent clutch disc contact speeds with the flywheel, which affects power transmission efficiency and vehicle performance.
Innovation Solution
A clutch system that controls hydraulic oil supply through a control valve using a sequence of current values to manage clutch disc speed, synchronizing it with the flywheel's rotational speed, thereby reducing shocks and optimizing engagement timing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If high hydraulic pressure is supplied to the clutch, then the clutch disc moves faster and engagement time is reduced, but the shock generated when the clutch disc contacts the flywheel becomes significant
Solution Approach 1:
The control valve dynamically adjusts the hydraulic pressure in multiple stages: initially providing high pressure to accelerate the clutch disc, then reducing pressure to control the contact speed with the flywheel. This dynamic pressure adjustment resolves the contradiction by adapting the hydraulic force to the real-time engagement state, achieving both fast engagement and shock reduction.
Solution Approach 2:
The control valve operates in periodic phases: a first phase with high current supply for rapid clutch disc movement, followed by a second phase with reduced current for controlled deceleration and contact. This periodic control pattern enables the system to achieve quick engagement while minimizing impact shock through staged pressure application.
2Object-generated harmful factors
If low hydraulic pressure is supplied to the clutch, then the shock is reduced, but the moving speed of the clutch disc decreases and engagement time becomes longer
Solution Approach 1:
The control valve dynamically changes hydraulic pressure levels during the engagement process, transitioning from high pressure for rapid movement to low pressure for controlled contact. This dynamic adjustment eliminates the need to choose between high speed and low shock, achieving both objectives through time-varying pressure control.
Solution Approach 2:
The control valve applies high hydraulic pressure in advance to accelerate the clutch disc to the desired position, then reduces pressure before contact occurs. This preliminary high-pressure action enables fast engagement while the subsequent pressure reduction prevents excessive shock, resolving the contradiction proactively.
3Speed
If constant high current is supplied to the control valve, then the clutch disc moves quickly, but the engagement shock increases and the transition to engaged state becomes abrupt
Solution Approach 1:
The control valve uses dynamic current adjustment rather than constant current supply. The current is initially high to achieve rapid clutch disc movement, then progressively reduced to control the engagement process and minimize shock. This dynamic electrical control translates to dynamic hydraulic pressure control, achieving both speed and smoothness.
Solution Approach 2:
The control valve changes the electrical current parameter over time during the engagement process. By varying the current from high to low values, the system controls the hydraulic pressure accordingly, enabling the clutch disc to achieve high initial speed while ensuring smooth engagement through parameter modulation.
4Productivity
If the clutch disc is accelerated rapidly to reduce engagement time, then productivity is improved, but the shock and mechanical stress on components increases
Solution Approach 1:
The control valve dynamically adjusts hydraulic pressure to optimize the engagement process: high pressure initially to achieve rapid engagement (improving productivity), then pressure reduction to control contact forces (reducing mechanical stress). This dynamic control enables the system to achieve both high productivity and component protection.
Solution Approach 2:
The control valve operates in periodic stages: a first stage with high hydraulic pressure for rapid clutch disc acceleration and engagement, followed by a second stage with reduced pressure to control contact and minimize stress. This periodic control pattern achieves both fast engagement and mechanical stress reduction.
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 reduces engagement shocks and shortens the transition time between disengaged and engaged states, enhancing power transmission efficiency and vehicle performance by aligning clutch disc and flywheel speeds.
Implementation Method 1
A clutch for connecting or disconnecting power transmission is known. Japanese Unexamined Patent Application Publication No. 2010-241244 discloses a technique for bringing a hydraulically operated clutch from a disengaged state to an engaged state by supplying hydraulic oil to the clutch.
Implementation Method 2
a control valve that supplies to the clutch an amount of the hydraulic oil corresponding to a current value of current supplied from a power source
Data Source
AI summary
A clutch system includes a clutch in which a clutch disc and a flywheel come into contact with each other, a control valve that supplies hydraulic oil to the clutch, and a supply control part that supplies electricity from a power source to the control valve. The supply control part supplies current at a first current value A1 to the control valve, then sets a current value of the current to a second current value A2 that is smaller than the first current value A1, and after setting the current value to the second current value A2, decreases the current value over time so that the current value reaches a third current value A3 that is smaller than the second current value A2 at a timing when the disengaged clutch is brought into an engaged state.