Hydraulic Clutch Control for Torque Peak Absorption in Gearshifts
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Solution Overview
Problem
Seamless gearboxes in saddle-ride vehicles face challenges in limiting torque peaks during gear upshifts, particularly when the drive shaft inertia is high, as existing control strategies require engine shutdown and precise synchronization, which are not always feasible.
Innovation Solution
A clutch control device that allows controlled slipping of the clutch without engine shutdown, using a hydraulic system with a primary and secondary piston to exert a force opposing the return means, enabling torque peak absorption during gear changes independently of drive shaft rotation speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the engine is switched off during gear change to prevent torque peaks, then torque peaks are limited, but the control strategy requires perfect synchronization between the gearbox and engine switching, which becomes infeasible when drive shaft inertia is high
Solution Approach 1:
The invention extracts the torque peak limitation function from the engine control unit to a dedicated device connected to the clutch assembly. This separate device mechanically limits torque peaks during gear changes without requiring complex electronic synchronization with the engine, thereby resolving the contradiction between limiting harmful torque peaks and avoiding complex control strategies.
2Productivity
If a seamless gearbox is used to maintain continuous torque transmission, then gear change time is reduced and chain pull stability is improved, but torque peaks increase during gear upshifts
Solution Approach 1:
The invention introduces an intermediary device between the clutch assembly and the gearbox that acts as a mechanical buffer during gear upshifts. This intermediary mechanism absorbs the torque peaks generated by the seamless gearbox operation, allowing the seamless gearbox to maintain its productivity benefits while the intermediary device protects against harmful torque spikes.
3Use of energy by stationary object
If the clutch is kept in closure condition to maintain power transmission, then continuous torque transmission is achieved, but torque peaks cannot be limited during gear changes
Solution Approach 1:
The invention implements a dynamic control mechanism that automatically adjusts the clutch engagement state during gear changes. The device detects gear change conditions and temporarily modifies the clutch closure force to limit torque peaks, then returns to full closure condition to maintain continuous power transmission. This dynamic adjustment resolves the contradiction between maintaining continuous power transmission and limiting torque peaks.
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 solution effectively limits torque peaks during gear upshifts without engine shutdown, simplifying the control unit and increasing the usability of seamless gearboxes, while being reliable and cost-competitive.
Implementation Method 1
a hydraulic system with a primary and secondary piston to exert a force opposing the return means
Data Source
AI summary
The present invention relates to a saddle-ride type vehicle comprising a clutch assembly (4), interposed between an engine (2) and a gearbox (3), which includes a clutch device (11) in turn comprising two clutch elements (one integral with the shaft of the engine and the other with the input shaft of the gearbox) and return means (12) that keep these elements (11A, 11B) in contact in a closure condition of the clutch. According to the invention, the clutch assembly (4) further comprises an operating device (21) of the clutch device that causes detachment of the elements (11A, 11B) of the clutch device up to an opening condition of the clutch assembly. This latter further comprises a control device (6) to limit the torque peaks during gear change. This device comprises an actuation means (5) that, during gear change, exerts a predetermined force (S) in contrast to the force exerted by said return means (12) of the clutch assembly, wherein said predetermined force (S) is less than the force (F) generated by the return means (12) so as to cause a mutual slip of the elements (11A, 11B) of the clutch device (11) without said opening condition being reached. The operating device (21) is of hydraulic type and comprises a primary pump (22) operated by means of a control lever (23), wherein this primary pump (22) is hydraulically connected, through a primary hydraulic circuit (16), to a primary piston (24) acting on at least one of the elements (11A, 11B) of the clutch device (11) in opposition to the return means (12) so that, following an action on the control lever (23), the primary piston (24) exerts an action the elements (11A, 11B) determining the opening condition. According to the invention, the control device (6) comprises a secondary piston (25) connected to the primary piston (24), wherein the actuation means (5) exerts, directly or indirectly, the predetermined force (S) on the secondary piston (25), said predetermined force (S) being transferred to the primary piston (24) in opposition to the force (F) of the return means (12).