Automatic transmission control system
First Claim
1. An automatic transmission for use in a vehicle driveline comprising multiple ratio gearing, adapted to provide multiple torque flow paths from a driving member to a driven member, a fluid pressure operated brake means for anchoring a reaction member for said gearing;
- first clutch means for delivering torque from said driving member to one torque input member of said gearing while said brake means is applied to establish one gear ratio;
second clutch means for delivering torque from said driving member to another torque input member of said gearing while said brake means is applied to establish another gear ratio, said first and second clutch means being applied simultaneously while said brake means is released to establish a gear ratio intermediate said one gear ratio and said other gear ratio; and
a fluid pressure accumulator means for cushioning application of said brake means during establishment of said one gear ratio and said other gear ratio;
said brake means including a double action servo having a piston that partially defines a brake apply pressure chamber and a brake release pressure chamber;
a pressure accumulator in fluid communication with said brake apply pressure chamber during operation of said transmission in said one gear ratio and said other gear ratio; and
control valve means for interrupting communication of said pressure accumulator with said brake apply pressure chamber when said intermediate gear ratio is established and establishing such communication when said one gear ratio and said other gear ratio are established.
2 Assignments
0 Petitions
Accused Products
Abstract
A hydrokinetic, multiple-ratio torque converter transmission mechanism having a simplified valve system with variable force solenoids for controlling line pressure as well as ratio shifts, a simplified clutch-and-brake hydraulic circuit with separate fluid pressure feed and exhaust passages, a common accumulator arrangement for controlling each of two ratio upshifts and a simplified brake servo mechanism having the dual function of establishing a torque reaction point for each of two distinct transmission ratios.
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Citations
15 Claims
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1. An automatic transmission for use in a vehicle driveline comprising multiple ratio gearing, adapted to provide multiple torque flow paths from a driving member to a driven member, a fluid pressure operated brake means for anchoring a reaction member for said gearing;
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first clutch means for delivering torque from said driving member to one torque input member of said gearing while said brake means is applied to establish one gear ratio; second clutch means for delivering torque from said driving member to another torque input member of said gearing while said brake means is applied to establish another gear ratio, said first and second clutch means being applied simultaneously while said brake means is released to establish a gear ratio intermediate said one gear ratio and said other gear ratio; and a fluid pressure accumulator means for cushioning application of said brake means during establishment of said one gear ratio and said other gear ratio; said brake means including a double action servo having a piston that partially defines a brake apply pressure chamber and a brake release pressure chamber; a pressure accumulator in fluid communication with said brake apply pressure chamber during operation of said transmission in said one gear ratio and said other gear ratio; and control valve means for interrupting communication of said pressure accumulator with said brake apply pressure chamber when said intermediate gear ratio is established and establishing such communication when said one gear ratio and said other gear ratio are established. - View Dependent Claims (2, 3, 4, 5)
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6. A geared transmission for establishing torque flow paths from a driving member to a driven member comprising fluid pressure operated brake means for braking a reaction member that is common to each of two torque flow paths, each torque flow path having a discrete gear ratio;
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first clutch means for delivering torque from said driving member to one torque input member of said transmission while said brake means is applied to establish one gear ratio; second clutch means for delivering torque from said driving member to another torque input member of said transmission while said brake means is applied and said first clutch means is applied to establish another gear ratio; said first and second clutch means both being applied while said brake means is released to establish a gear ratio intermediate said one gear ratio and said other gear ratio; said brake means including a double action servo having a piston that partially defines a brake apply pressure chamber and a brake release pressure chamber; a pressure accumulator in fluid communication with said brake apply pressure chamber during operation of said transmission in said one gear ratio and said other gear ratio; and control valve means for interrupting communication of said pressure accumulator with said brake apply pressure chamber when said intermediate gear ratio is established and establishing such communication when said one gear ratio and said other gear ratio are established. - View Dependent Claims (7, 8, 9)
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10. An automatic transmission for use in a vehicle driveline comprising multiple ratio gearing, adapted to provide multiple torque flow paths from a driving member to a driven member, a fluid pressure operated brake means for anchoring a reaction member for said gearing;
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first clutch means for delivering torque from said driving member to one torque input member of said gearing while said brake mans is applied to establish one gear ratio; second clutch means for delivering torque from said driving member to another torque input member of said gearing while said brake means is applied to establish another gear ratio, said first and second clutch means being applied simultaneously while said brake means is released to establish a gear ratio intermediate said one gear ratio and said other gear ratio; a fluid pressure accumulator means for cushioning application of said brake means during establishment of said one gear ratio and said other gear ratio, separate fluid pressure feed passage means and fluid pressure return passage means communicating with said first and second clutch means and with said brake means, and a calibrated flow control orifice in said pressure feed passage means for controlling engagement timing, the fluid return flow in said return passage means being unrestricted thereby effecting rapid disengagement of said first and second clutch means and said brake means.
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11. A geared transmission for establishing torque flow paths from a driving member to a driven member comprising fluid pressure operated brake means for braking a reaction member that is common to each of two torque flow paths, each torque flow path having a discrete gear ratio;
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first clutch means for delivering torque from said driving member to one torque input member of said transmission while said brake means is applied to establish one gear ratio; second clutch means for delivering torque from said driving member to another torque input member of said transmission while said brake means is applied and said first clutch means is applied to establish another gear ratio; said first and second clutch means both being applied while said brake means is released to establish a gear ratio intermediate said one gear ratio and said other gear ratio; separate fluid pressure feed passage means and fluid pressure return passage means communicating with said first and second clutch means and with said brake means, and a calibrated flow control orifice in said pressure feed passage means for controlling engagement timing, the fluid return flow in said return passage means being unrestricted thereby effecting rapid disengagement of said first and second clutch means and said brake means.
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12. An automatic transmission control system for a geared transmission having multiple forward gear ratios and a reverse gear ratio;
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said gearing providing forward driving torque delivery paths and a reverse torque delivery path from a driving member to a driven member; a control valve circuit including a pressure source, a regulator valve means for regulating said pressure source; a forward drive clutch means for establishing and disestablishing a driving connection between said driving shaft and forward drive torque input elements of said gearing, a reverse drive clutch means for establishing and disestablishing a driving connection between said driving shaft and reverse drive torque input elements of said gearing, a low and reverse drive brake means for anchoring a reaction element of said gearing during reverse drive and during forward drive; and a manual valve means communicating with said regulator valve means for selectively distributing pressure to said low and reverse drive brake means and said reverse drive clutch means and to said low and reverse drive brake means and said forward drive clutch means; said circuit including separate fluid pressure delivery passages between said manual valve means and each of said reverse drive clutch means and said low and reverse drive clutch means, the pressure delivery passage for said low and reverse drive brake means including a calibrated flow restricting orifice whereby said low and reverse drive clutch means becomes applied after application of said reverse drive clutch upon movement of said manual valve to the reverse drive position thus effecting cushioning and smooth engagement for said low and reverse drive brake means and said reverse drive clutch means. - View Dependent Claims (13, 14, 15)
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Specification