Hydraulic Clutch Flow Restraint for Negative Pressure
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Solution Overview
Problem
The existing vehicle hydraulic clutch apparatus experiences negative pressure issues during quick pedal return operations, leading to increased ineffective stroke and reduced operability due to inertial energy of working oil flowing from the concentric slave cylinder to the clutch master cylinder.
Innovation Solution
Incorporating a flow restraint device, such as an orifice or throttle hole, in the oil passageway within the concentric slave cylinder to reduce inertial energy and prevent negative pressure by varying flow resistance based on the direction of oil flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the clutch pedal is quickly returned from the depressed position, then the working oil flows swiftly from the concentric slave cylinder side to the clutch master cylinder side, but negative pressure occurs in the oil passageway due to the inertia of the working oil
Solution Approach 1:
A flow restraint device is introduced as an intermediary element in the oil passageway between the concentric slave cylinder and clutch master cylinder. This device restricts the flow of working oil during quick pedal return, preventing negative pressure generation while still allowing normal clutch operation. The flow restraint device acts as a mediator that controls the inertial flow of oil to maintain system reliability.
Solution Approach 2:
The flow restraint device changes the flow resistance parameter of the working oil during pedal return. By increasing flow resistance in the reverse direction, the device prevents the working oil from flowing too swiftly back to the master cylinder, thereby avoiding negative pressure and maintaining clutch pedal operability.
2Stability of the object's composition
If gaps are provided in the concentric slave cylinder to absorb engine vibration, then vibration absorption is improved, but the play of the initial stroke of the clutch pedal increases when negative pressure occurs
Solution Approach 1:
The flow restraint device converts the harmful effect of quick oil flow (which causes negative pressure and increases initial stroke play) into a beneficial effect. By restraining the flow, the device prevents negative pressure formation, ensuring that the gaps used for vibration absorption do not lead to excessive pedal play, thus maintaining both vibration absorption and operational precision.
3Speed
If the working oil flows freely from the slave cylinder to the master cylinder, then the system responds quickly to pedal release, but the inertial energy of the working oil causes negative pressure and increases ineffective stroke
Solution Approach 1:
The flow restraint device serves as an intermediary that controls the speed and direction of working oil flow. During pedal release, it allows sufficient flow speed for system response while restraining excessive inertial flow that would cause negative pressure and increase ineffective stroke, thus optimizing the balance between response speed and operational efficiency.
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 flow restraint device effectively reduces negative pressure occurrences, minimizing the ineffective stroke and enhancing clutch pedal operability by managing pressure loss and flow resistance, thereby improving the overall performance of the hydraulic clutch apparatus.
Implementation Method 1
Due to the influence of the inertia of the working oil, negative pressure occurs in the oil passageway
Implementation Method 2
a flow restraint device that restrains flow of the working oil from a concentric slave cylinder side to a clutch master cylinder side
Data Source
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AI summary
A vehicle hydraulic clutch apparatus includes a clutch master cylinder that generates clutch working oil pressure in response to operation of a clutch pedal, and a concentric slave cylinder that engages and releases a friction clutch as the clutch working oil pressure generated by the clutch master cylinder is supplied thereto and discharged therefrom via an oil passageway. A flow restraint device (130, 200) that restrains flow of the working oil from a concentric slave cylinder (66) side to a clutch master cylinder (62) side which occurs according to operation of the clutch pedal (60) is provided in the concentric slave cylinder (66).