Abstract: A steering damper in a motorcycle includes a vane partitioning a chamber in a damper housing into two oil chambers, wherein hydraulic fluid flows between the two chambers to generate attenuating force. The steering damper also includes a damper shaft connected to the vane and supporting the vane for rocking motion with respect to the housing, and a hydraulic pressure control valve. The housing is attached to a head pipe, and the damper shaft is attached to a steering system. When the head pipe is to be attached to the housing, the housing is extended rearwardly behind a top bridge, and a linear solenoid for driving and controlling the hydraulic pressure control valve is attached to the housing and disposed below the extension thereof.

Abstract: A liquid pressure type steering damper system for generating a damping force for preventing a handle from being swung due to a kick-back upon a disturbance wherein the generation of the damping force is nonlinear so that the steering angle would not be enlarged so much even if the kick-back becomes greater. A liquid pressure type steering damper is provided with a restriction passage for a working liquid and a solenoid-type control valve for varying the passage sectional area of the restriction passage. A needle portion is formed at the tip end of a plunger constituting the solenoid valve and is made to advance and retract in a restriction portion connected to a bypass passage.

Abstract: A downshift control method for an automatic transmission, which transmission is normally downshifted, to increase a gear ratio, when a vehicle throttle is opened more than a preset value. The method includes a step of selecting a slip-determining threshold on the basis of an instantaneous steering angle of a vehicle. The method also includes steps of detecting a perceived rear wheel speed Vs, and averaging a number of rear wheel speeds Vs to derive an average vehicle speed Va. The normal downshift procedure is overridden, and the automatic transmission is prevented from downshifting, if a difference between the perceived rear wheel speed and the average vehicle speed exceeds the slip-determining threshold T, and the rear wheels are determined to be slipping.

Abstract: A static hydraulic continuously variable transmission includes a fixed capacity swash type hydraulic pump and a variable capacity swash type hydraulic motor, connected by a hydraulic closed circuit. A control system and method controls hydraulic pressure in the variable transmission, and thereby reduces the likelihood of noise in the variable transmission under certain driving conditions. The hydraulic pressure is controlled by changing the inclination angle of a movable swash plate. The driving conditions which prompt the control system may include: (1) A signal voltage of a throttle sensor indicates the throttle opening is lower than a first threshold value; (2) A vehicle speed is over a second threshold value; (3) An acceleration is over a third threshold value; (4) An engine speed is below a fourth threshold value; and (5) Conditions (1) through (4) last for a predetermined period of time.

Abstract: To make steerability more satisfactory in conformity with actual operation, by correcting the regulation of a damping force based on a variable quantity which has a close relationship with the magnitude of kick-back and with which the steering conditions at the time of actual operation can be grasped appropriately, in contrast to the system in which the regulation of the damping force is controlled linearly in proportion to a variable quantity related to the magnitude of kick-back. In a steering damper system of the liquid pressure type in which a damping force is exerted on a front wheel steering system provided at a front portion of a vehicle body and which comprises a control valve for making the damping force variable, the damping force is controlled based on the steering speed.

Abstract: A liquid pressure type steering damper system for generating a damping force for preventing a handle from being swung due to a kick-back upon a disturbance wherein the generation of the damping force is nonlinear so that the steering angle would not be enlarged so much even if the kick-back becomes greater. A liquid pressure type steering damper is provided with a restriction passage for a working liquid and a solenoid-type control valve for varying the passage sectional area of the restriction passage. A needle portion is formed at the tip end of a plunger constituting the solenoid valve and is made to advance and retract in a restriction portion connected to a bypass passage.

Abstract: A hydrostatic continuously variable transmission includes a fixed capacity hydraulic pump and a variable capacity hydraulic motor, connected by a hydraulic closed circuit. A control system and method for the variable transmission provides a good deceleration feeling when going downhill. In accordance with the control system and method, a range of a selected gear is determined. Next, it is determined whether the vehicle is in an automatic gear shift mode. If these conditions are met, it is then determined whether or not certain criteria for descent control are satisfied. The certain criteria may include: (1) whether the throttle is closed; (2) a speed or acceleration of the vehicle; (3) whether the acceleration exceeds a threshold; and (4) whether simultaneous satisfaction of conditions (1)-(3) exist for a period of time exceeding a fixed time. If all of the criteria are satisfied, the gear ratio is shifted by a specified amount towards a LOW side.

Abstract: A transmission system including an automatic transmission having a plurality of speed change modes, including at least a continuously variable speed change node and a steeping speed change mode, and a sub-transmission connected to the automatic transmission. The sub-transmission is capable of switching to one of a plurality of running ranges including at least a forward range, a neutral range, and a reverse range. The transmission system also includes a mode switch for selectively switching to one of the plurality of speed change modes of the automatic transmission, and a shift switch for switching from one speed change stage to another speed change when the stepping speed change mode is active. Functionally of the shift switch and the mode switch are collectively integrated into a common switch, and the common switch is selectively used as the shift switch or the mode switch.

Abstract: A variable transmission system includes a continuously variable transmission, a shiftable sub-transmission in series with an output of the continuously variable transmission, and controller. A sensor senses a position of a driver's shift lever, and another sensor senses a gear position of the shiftable sub-transmission. The sensors report to the controller. If both sensors detect reverse drive conditions, the controller adjusts an angle of a swash plate of the continuously variable transmission for the reverse driving direction. If only one of the sensors indicates a rear drive condition, the controller compares an engine speed to a threshold value. If the engine speed exceeds the threshold value, the controller curbs the engine speed by cutting off the ignition.

Abstract: A method of diminishing shift shock in a stepped shift mode in a continuously variable transmission. A continuously variable transmission having an automatic shift mode and a stepped shift mode possesses a shift shock diminishing control function. In this control, when shift-down is made in the stepped shift mode (S.1), a timer is allowed to start counting (S.2) and the magnitude of deceleration G during change of the change gear ratio by a control motor is compared with a threshold value (S.4), and if the deceleration magnitude is larger than the threshold value, the supply of electric power to the control motor is stopped for only a very short time to decrease the deceleration G thereby diminishing the shift shock (S.5).

Abstract: A continuously variable hydrostatic transmission in which a fixed displacement hydraulic pump and a variable displacement hydraulic motor are disposed on a drive axle, and connected via a closed hydraulic circuit. The continuously variable hydrostatic transmission shifts gears by changing the inclination angle of a movable swashplate provided for the variable displacement the hydraulic motor. The continuously variable hydrostatic transmission may perform a correction control, where the movable swashplate is moved to the TOP side, and the maximum value of the shift amount is obtained. Then, the movable swashplate is moved to the LOW side, and the minimum value is obtained. By storing the maximum and minimum values, correction data is derived. After that, the TOP and LOW transmission gear ratios are determined on the basis of the correction data.

Abstract: An overtop position is to be established in a hydrostatic type continuously variable transmission, and an increase of the maximum speed and the maintenance of power performance are to be made compatible with each other. In a hydrostatic type continuously variable transmission, the angle of inclination of a movable swash plate is controlled in such a manner that a target Ne is calculated from both RC (riding condition) and throttle valve opening, then the target Ne thus calculated is compared with an actual Ne to determine a rotational direction and DUTY of a control motor. The operation of the control motor is controlled in accordance with the thus-determined data and angle information on the angle of the movable swash plate provided from an angle sensor.

Abstract: A method of diminishing shift shock in a stepped shift mode in a continuously variable transmission. A continuously variable transmission having an automatic shift mode and a stepped shift mode possesses a shift shock diminishing control function. In this control, when shift-down is made in the stepped shift mode (S.1), a timer is allowed to start counting (S.2) and the magnitude of deceleration G during change of the change gear ratio by a control motor is compared with a threshold value (S.4), and if the deceleration magnitude is larger than the threshold value, the supply of electric power to the control motor is stopped for only a very short time to decrease the deceleration G, thereby diminishing the shift shock (S.5).

Abstract: A hydrostatic continuously variable transmission includes a fixed capacity hydraulic pump and a variable capacity hydraulic motor, connected by a hydraulic closed circuit. A control system and method for the variable transmission provides a good deceleration feeling when going downhill. In accordance with the control system and method, a range of a selected gear is determined. Next, it is determined whether the vehicle is in an automatic gear shift mode. If these conditions are met, it is then determined whether or not certain criteria for descent control are satisfied. The certain criteria may include: (1) whether the throttle is closed; (2) a speed or acceleration of the vehicle; (3) whether the acceleration exceeds a threshold; and (4) whether simultaneous satisfaction of conditions (1)-(3) exist for a period of time exceeding a fixed time. If all of the criteria are satisfied, the gear ratio is shifted by a specified amount towards a LOW side.

Abstract: A variable transmission system includes a continuously variable transmission, a shiftable sub-transmission in series with an output of the continuously variable transmission, and controller. A sensor senses a position of a driver's shift lever, and another sensor senses a gear position of the shiftable sub-transmission. The sensors report to the controller. If both sensors detect reverse drive conditions, the controller adjusts an angle of a swash plate of the continuously variable transmission for the reverse driving direction. If only one of the sensors indicates a rear drive condition, the controller compares an engine speed to a threshold value. If the engine speed exceeds the threshold value, the controller curbs the engine speed by cutting off the ignition.

Abstract: A transmission system including an automatic transmission having a plurality of speed change modes, including at least a continuously variable speed change mode and a steeping speed change mode, and a sub-transmission connected to the automatic transmission. The sub-transmission is capable of switching to one of a plurality of running ranges including at least a forward range, a neutral range, and a reverse range. The transmission system also includes a mode switch for selectively switching to one of the plurality of speed change modes of the automatic transmission, and a shift switch for switching from one speed change stage to another speed change when the stepping speed change mode is active. Functionality of the shift and the mode switch are collectively integrated into a common switch is selectively used as the shift switch or the mode switch.

Abstract: A static hydraulic continuously variable transmission includes a fixed capacity swash type hydraulic pump and a variable capacity swash type hydraulic motor, connected by a hydraulic closed circuit. A control system and method controls hydraulic pressure in the variable transmission, and thereby reduces the likelihood of noise in the variable transmission under certain driving conditions. The hydraulic pressure is controlled by changing the inclination angle of a movable swash plate. The driving conditions which prompt the control system may include: (1) A signal voltage of a throttle sensor indicates the throttle opening is lower than a first threshold value; (2) A vehicle speed is over a second threshold value; (3) An acceleration is over a third threshold value; (4) An engine speed is below a fourth threshold value; and (5) Conditions (1) through (4) last for a predetermined period of time.

Abstract: To provide a failure diagnosing circuit capable of carrying out failure diagnosis of respective switching elements of a bridge circuit without rotating a motor. Pull up/down terminals and as well as monitor terminals are respectively connected to both input terminals of a motor. The pull up/down terminals selectively provide two states: a pull up state providing voltage 5 V for failure diagnosis to the motor input terminals via resistors and a pull down state providing ground potential to the motor input terminals via the resistors. A failure diagnosing circuit switches the two states of the pull up/down terminals, opens and closes any one element of switching elements and monitors a change in the potential of the monitor terminal corresponding to each of the combinations of switching the states and opening and closing of the switching elements by which failure diagnosis of the opened and closed switching element is carried out.