Automatic transmission

Abstract

Abstract IN GENERAL, IN A FLUID AUTOMATIC TRANSMISSION COMPOSED OF A TORQUE CONVERTER AND A PLANETARY GEAR SYSTEM PROVIDED WITH A MULTIPLE DISC CLUTCH AND A BRAKE BAND, WHEN THE VEHICLE IS RUNNING IN DRIVE RANGE IT IS UNABLE TO AVOID SHOCK GIVEN TO THE DRIVER AT THE TIME OF AUTOMATIC GEAR CHANGE FOR UP-SHIFT OR DOWN-SHIFT OF SPEED. THE CONTROL SYSTEM ACCORDING TO THE PRESENT INVENTION IS INTENDED TO PREVENT OCCURRENCE OF THE ABOVE SHOCK WHICH GIVES THE DRIVER AN UNCOMFORTABLE FEELING OR UNEASINESS BY MEANS OF COMPARATIVELY SIMPLE METHODS. THAT IS, A PURE FLUID ELEMENT, FOR INSTANCE, A FLUID AMPLIFIER IS PROVIDED ON ONE OR BOTH OF THE PIPE-LINES FOR APPLYING OR RELIEVING HYDRAULIC PRESSURE TO THE MULTIPLE DISC CLUTCH SERVO PISTON AND TO THE BRAKE BAND SERVO PISTON AND BY UTILIZING THE DIFFERENT RESISTANCE CHARACTERISTICS OF THIS PURE FLUID ELEMENT IN THE FORWARD AND REVERSE DIRECTIONS OF THE PRESSURE OIL, A DIFFERENCE OF TIME CONSTANT IS PRODUCED BETWEEN ENGAGING AND DISENGAGING OF THE CLUTCH AND THE BRAKE BAND, WHEREBY IT IS CONTEMPLATED THAT THE MULTIPLE DISC CLUTCH IS SLOWLY ENGAGED FOR SHIFTING UP THE SPEED AFTER THE BRAKE BAND HAS BEEN DISENGAGED AND THE BRAKE BAND IS SLOWLY ENGAGED FOR SHIFTING DOWN THE SPEED AFTER THE MULTIPLE DISC CLUTCH HAS BEEN DISENGAGED, THUS REDUCING THE SHOCK AT TIME OF AUTOMATIC GEAR CHANGE TO MINIMUM. MOREOVER, THE PRESENT INVENTION CONTEMPLATES THAT THE GOVERNOR PRESSURE HAVING RELATION TO THE VEHICLE SPEED IS APPLIED TO THE CONTROL PORT OF SAID FLUID AMPLIFIER AND A DIFFERENCE OF THE SHOCK AT TIME OF AUTOMATIC GEAR CHANGE CAUSED BETWEEN HIGH SPEED AND LOW SPEED AT WHICH THE VEHICLE IS RUNNING IN THE DRIVE RANGE IS ALSO ELIMINATED, SO THAT A MORE COMFORTABLE AND ALMOST SHOCKLESS AUTOMATIC GEAR CHANGE CAN BE ACCOMPLISHED.

Inventors

• 👤 Tomoo Ishihara
• 👤 Katsuya Suzuki
• 👤 Hajime Arai
• 👤 Hisaji Nishikawa
• 👤 Shin Ito

Bibliographic Details