Abstract: Actual-rotational-difference absorption-torque calculation means 150 inputs a rate-of-change ?Ne of an engine speed during shifting to an actual rotational difference absorption torque-?Ne table 160 so that an actual-rotational-difference absorption-torque average value during shifting is calculated. Engine-torque calculation means 180 inputs a throttle opening and an engine speed to engine-torque estimation-value map 190, and derives an engine torque during shifting. An actual clutch capacity is calculated from the sum of the actual-rotational-difference absorption-torque average value and the engine torque average value during shifting. From the ratio of the actual clutch capacity and a demanded clutch capacity, ?-correction-coefficient calculation means 130 calculates a ? correction coefficient. By using a control correction amount calculated on the basis of the ? correction coefficient, a transmission control unit 100 drive-controls a first clutch CL1 and a second clutch CL2.

Abstract: A power unit for a vehicle includes first and second clutches, that transmit/interrupt rotary power from a primary reduction gear mechanism to first and second main shafts, arranged at respective ends of the first and second main shafts with selectively established multispeed gears provided among a countershaft, and the first and second main shafts. The primary reduction gear mechanism includes: a single driving gear provided on a crankshaft; a first driven gear supported by a first main shaft for relative rotation therewith at a position adjacent to the first clutch and meshes with the driving gear; an intermediate driving gear rotating with the first driven gear; an idle gear that meshes with the intermediate driving gear, and supported by the countershaft for relative rotation therewith; and a second driven gear, that meshes with the idle gear, and supported by the second main shaft for relative rotation therewith.

Abstract: A hybrid vehicle in which an electric motor is disposed in the vicinity of a center of a vehicle body to reduce lateral expansion. The hybrid vehicle includes an engine, a motor, and a power transmission mechanism for transmitting power of the engine and the motor to a rear wheel. The engine is suspended on the vehicle body in a non-swingable manner with a cylinder extending in a substantially horizontal direction and a crankshaft provided to be oriented in a vehicle width direction. The electric motor is located in front of and above the crankshaft of the engine.

Abstract: A vehicle transmission wherein a single shift spindle is provided with a master arm to operate the transmission via an accumulation mechanism and a clutch lever to operate a clutch, capable of more reliably realizing disconnection of the clutch after the completion of accumulation necessary for a shift operation. A vehicle transmission includes a master arm provided on a shift spindle for transmitting a rotational force to a shift drum of a transmission to rotate and operate the shift drum with a clutch lever provided on the shift spindle, to operate the clutch. An accumulation mechanism is capable of accumulating the rotational force transmitted from the shift spindle to the master arm. The master arm and the clutch lever are interlocked with each other. A delay mechanism is provided that delays the clutch disconnection operation with the clutch lever before accumulation is completed between the shift spindle and the clutch.

Abstract: A technique for enabling reduction of fuel consumption without greatly changing an engine structure and without impairing a feeling of operation of a vehicle as a motorcycle. An engine includes a crankshaft and a primary gear integrated with the crankshaft that is attached such that the power of the engine is transmitted to a wheel. A one-way clutch transmits the power from the crankshaft to the primary gear but does not transmit the power from the primary gear to the crankshaft. The one-way clutch is provided between the crankshaft and the primary gear with a regenerative brake motor being provided on the primary gear. The engine is non-swingable mounted on the vehicle body with a cylinder extending in a substantially horizontal direction and a crankshaft provided to be oriented in a vehicle width direction. An electric motor is located in front of and above the crankshaft of the engine.

Abstract: Oil pressure detecting means 150 detects a clutch oil pressure in driving a clutch in its engaging direction against a biasing force of a return spring 12 for normally disengaging the clutch. Stroke end detecting means 140 detects that the clutch has reached a stroke end position where clutch disks are in contact with each other when the amount of change in clutch oil pressure becomes larger than a predetermined value. Clutch control correction amount calculating means 130 calculates a work load generated in the return spring 12 according to the clutch oil pressure detected at the stroke end position and then calculates a control correction amount for the clutch according to the difference between the work load calculated above and a predetermined reference value.

Abstract: In an automatic speed change control system for a vehicle wherein a transmission is operated by use of an actuator, to contrive an alleviation of the burden in a shifting operation made by the user after a system starting operation. A shift actuator for controlling the speed change operation of the transmission is provided in a power transmission path. When the transmission is not in a neutral condition at the time when a predetermined system starting operation is conducted, the shift actuator is operated so as to put the transmission into the neutral condition.

Abstract: In a normally-open type clutch structure operatively connected to a vehicle which includes an engine, a drive wheel driven by the engine, and an automatic transmission arranged between the engine and the drive wheel. A clutch operating mechanism is provided having an actuator for engaging or disengaging a clutch connected to the automatic transmission. The clutch operating mechanism performs a control so as to bring the clutch into an engaged state when the actuator is operated, and clutch operating mechanism operates the clutch so as to bring the clutch into a disengaged state when the actuator is not operated.

Abstract: A transmission controller for a continuously variable transmission system steadily returns a gear ratio toward the low-ratio range, even after a driving pulley has stopped during sudden deceleration. A control unit is provided which drives an actuator to move a driving-pulley movable half part to a position in the low-ratio range when a vehicle speed sensor detects the sudden deceleration of a body, a pulley number-of-revolution sensor detects stopping of the driving pulley, and then a gear ratio sensor detects that the gear ratio of the continuously variable transmission system has not returned to the low-ratio range where a sufficient acceleration is obtainable at the time of restart. Upon detecting a restart, the control unit presses the driving-pulley movable half part onto a V-belt to prevent sliding therebetween and thereby reduce a loss in the transmission of a driving force at the time of restart.

Abstract: This twin-clutch apparatus for use in a transmission of an engine, including: a hydraulic first disk clutch and second disk clutch that exert a predetermined engagement force by pressure members displaced in an axial direction by the pressure of a supply oil from outside, the first disk clutch and the second disk clutch being coaxially arranged adjacent to each other, in which: clutch plates of the first disk clutch and clutch plates of the second disk clutch are different in thickness from each other.

Abstract: A clutch control system for a twin-clutch type automatic/manual transmission AMT includes a hydraulic pump for driving a first clutch and a second clutch and oil passages for transmitting oil pressures and an AMT control unit for controlling the supply of oil pressures into the oil passages. Upon detection of an engine starting operation, the AMT control unit performs an initial preparatory operation in which the oil pressures are supplied into the oil passages at different timings so as to fill up the oil passages with a working oil, thereby completing the preparations for driving of the clutches. When the oil pressure is supplied into the oil passage after a predetermined oil pressure is generated in the oil passage, the period of time taken for a first speed gear to become usable is shortened, whereby a swift vehicle starting after the starting of the engine can be achieved.

Abstract: To achieve downsizing of a power unit and the vicinity thereof by permitting compact axial arrangement in a straddle-ride type vehicle on which the power unit having a twin-clutch type transmission is mounted. The transmission has a pair of main shafts with respective different axes and corresponding clutches. One of respective axial centers of the main shafts is disposed on one (above) of the sides with respect to a line and the other is disposed on the other side (below), the line connecting an axial center of the counter shaft with an axial center of a pivot shaft, as viewed in side elevation from the axial direction of the main shafts and counter shaft.

Abstract: A saddle type vehicle having mounted thereon a power unit is provided with a twin clutch type transmission including a pair of main shafts and a pair of clutches along different axes, to enable a compact layout of axes and a reduction in size of the unit and its surroundings. The axis center (first main axis) of a first main shaft is disposed rearwardly of the axis center (crank axis) of a crankshaft and forwardly of the axis center (counter axis) of a counter shaft, whereas the axis center (second main axis) of a second main shaft is disposed rearwardly of the axis center (counter axis) of the counter shaft and forwardly of the axis center (pivot axis) of a pivot shaft.

Abstract: An air bleeding valve includes an annular valve element for removing air from oil contained in a hydraulic circuit of a hydraulic tensioner and for suppressing the removal of the oil. An air bleeding valve body is fitted in an air bleeding valve accommodating hole formed in the hydraulic tensioner. A circumferential groove having a rectangular cross section is formed on an outer circumferential surface of the air bleeding valve body. The annular valve element having a rectangular cross section is fitted in the circumferential groove so as to be movable in an axial direction parallel to the axis of the annular valve element, and displaceable in a radial direction toward and away from the axis of the annular valve element. Such air bleeding valve removes air in a hydraulic circuit while suppressing the removal of oil in the hydraulic circuit during starting operation of an engine.

Abstract: In a vehicle power unit including a twin clutch type transmission that includes a pair of main shafts and clutches mounted on mutually different shafts, to enable compact shaft arrangements and to achieve a reduction in the size of the unit and the surrounding areas. Axial centers of a shift drum and a countershaft are disposed across a line that connects axial centers of main shafts in a side view as viewed from a direction of an axis of each of the main shafts and the countershaft.

Abstract: A clutch device is configured to include a clutch mechanism, a clutch actuator operatively engaging and disengaging the clutch mechanism, a clutch lever, and an assist pressure generator which generates assist hydraulic pressure by driving an electric motor. The assist hydraulic pressure is supplied to the clutch actuator to operatively engage and disengage the clutch mechanism. The clutch device further includes a first turning angle sensor which detects the turn operation angle of the clutch lever, a control unit which controllably drives the electric motor based on the turning operation amount of the clutch lever and adjusts the driving force generating gain characteristic of the electric motor, and a gain adjustment knob which variably sets the gain characteristic. The clutch device makes it possible to changeably set the magnitude of an assist force of an assist device according to a rider's preference.

Abstract: An apparatus includes a clutch control unit to control a control amount of a clutch and a brake to temporarily stop an output side rotating body while the clutch is disconnected. A clutch-control-amount detector detects the control amount of the clutch and an engagement start detector detects an engagement start of the clutch when a rotational speed difference between the input side rotating body and the output side rotating body becomes equal to or less than a predetermined value. An engagement-start control-amount detector detects the control amount of the clutch in the engagement start and a clutch-correction-control-amount deriver derives a correction control amount of the clutch based on the control amount of the clutch at the time when the engagement start is detected after the output side rotating body is temporarily stopped. The clutch control unit feedback-controls the control amount of the clutch based on the correction control amount.

Abstract: A speed change controlling apparatus in which the mode of driving force transmission is depends upon the roll angle of a vehicle body. When a roll angle is within a range from a second roll angle, which corresponds to a full bank state, to a first roll angle, speed change operation is carried out by soft speed change control in which variation of the driving force with respect to time is smaller than that by normal speed change control. If the roll angle is within another range from the first roll angle to a third roll angle, then normal speed change is carried out and if the roll angle is within a further range from an uprightly standing state to the third roll angle, then speed change operation is executed by direct speed change. When the roll angle is greater than the second roll angle, speed change is inhibited.

Abstract: In a clutch control system for a vehicle having a hydraulic type clutch in the course of power transmission between an engine and a drive wheel the operational response of the clutch is enhanced and the influence of a hysteresis present in oil pressure-stroke characteristic is suppressed. When the clutch is disconnected, a control oil pressure thereof is maintained at a predetermined stand-by oil pressure (allowance compensating oil pressure) P1. At the time of connecting the clutch, the control oil pressure is increased to a predetermined connection oil pressure P2. In bringing the clutch from the connected state into the disconnected state, the control oil pressure is lowered to an oil pressure P3 being below the stand-by oil pressure P1 and being near 0, and is thereafter increased again to the stand-by oil pressure P1.

Abstract: A transmission is provided in which gear trains for multiple shift stages are provided between a countershaft and a first main shaft and second main shaft running coaxially and relatively rotatably through the first main shaft so that the gear trains can be alternatively established, wherein a plurality of odd number stage gear trains (G1, G3, G5) are provided between the second main shaft (27) and the countershaft (28) so that the first speed gear train (G1) is disposed on the opposite side to the first and second clutches (37, 38), an end part of the second main shaft (27) on the first speed gear train (G1) side is rotatably supported on an engine main body via a main shaft side ball bearing (31) having a larger diameter than an outer diameter of a first speed drive gear (89) provided integrally with the second main shaft (27), and an outer race (31a) of the main shaft side ball bearing (31) is fixed to the engine main body via a fixing plate (95) engaging with an outer peripheral part of the outer race (31