OIL PRESSURE RETARDER SPEED CHANGING METHOD AND OIL PRESSURE RETARDER DEVICE OF POWER TRANSMISSION

摘要

PURPOSE:To restrain sudden retarder braking torque and speed changing shock by weakening the oil pressure retarder brake while a gear is shifted down, when the gear is to be shifted down at the time of applying oil pressure retarder brake. CONSTITUTION:Absorption torque becomes small when TVC signal is large. Thus pump absorption torque as designated by TVC is generated and this torque becomes a retarder brake torque. When a gears is shifted down by operating a speed change lever 10, when retarder brake is applied, from F3 running to F2 running, from F3 running to F1 running or from F2 running to F1 running, a controller 50 input these speed signals. Until a retarder switch 60 is switched over to an OFF position, the output of a retarder drive signal S10 is temporarily stopped when it is shifted down from F3 running to F2 running and completely stopped when it is shifted down from F2 running to F1 running in accordance with the procedure memorized beforehand.