Patent ID: 6382379
Filing Date: 2002-05-07
Classification: B62K,B62M,F02B,F16H

Abstract:
In a small-sized vehicle comprising an engine having a crankshaft and a multi-stage transmission having an input shaft, a transmitting system is interposed between the crankshaft and the input shaft and comprises a fluid transmitting means, said crankshaft and said input shaft being connected to each other through said fluid transmitting means including a pump impeller leading to the engine, and a turbine impeller leading to said multi-stage transmission,wherein said transmitting system includes a shifting clutch which is interposed between said crankshaft of the engine and said input shaft of said multi-stage transmission, said shifting clutch being in a series relation to said fluid transmitting means, and a lock-up clutch, which is interposed between said pump impeller and said turbine impeller of said fluid transmitting means, said lock-up clutch being capable of connecting both said impellers directly to each other; wherein said lock-up clutch comprises a pump extension connected to said pump impeller and surrounding said turbine impeller, a pressure receiving plate coupled to a tip end of said pump extension to define, within said pump extension, a hydraulic pressure chamber communicating with an oil chamber defined between said pump impeller and said turbine impeller, a pressing plate opposed to said pressure receiving plate and biased toward said pressure receiving plate by a hydraulic pressure in said hydraulic pressure chamber, an annular friction clutch plate interposed between said pressure receiving plate and said pressing plate and connected to said turbine impeller, first and second valve bores provided in said pressing plate and said pressure receiving plate on the side of an inner periphery of said friction clutch plate, respectively, a control valve provided in said pressing plate to close said first valve bore, a control rod which is received in said first and second valve bores and movable between a retracted position in which said control rod causes the inner periphery of said friction clutch plate to be open outside said second valve bore, while permitting the closing of said control valve, and an advanced position in which said control rod causes said control valve to be open to permit the inner periphery of said friction clutch plate to communicate with said hydraulic pressure chamber, while closing said second valve bore, and an operating means for operating said control rod.