Abstract: A centrifugal clutch includes a clutch weight in a plane perpendicular to a rotation axis of an input member for enabling friction fitting to an inside of a clutch housing. The clutch weight is turnably supported by a drive plate. A grooved portion is provided on a clutch weight in a position that is opposite to a drive plate. At least one end of grooved portion is closed and is formed in a turning direction of the clutch. A damping rubber supported by the drive plate abuts against an inside face of the grooved portion. The damping rubber is held in the grooved portion in a compressed state by being compressed between the drive plate and the clutch weight. The centrifugal clutch so configured effectively inhibits vibration of a clutch weight when the clutch is let in, and minimizes both the parts required and man-hours for assembly.

Abstract: A continuously variable transmission is mounted on a vehicle capable of selecting plural drive modes and changes a target engine speed between drive modes. A pulley ratio is controlled by a motor. An ECU for transmission control includes a calculation section which outputs a target engine speed as a function of throttle opening and vehicle speed, and a motor control value determination section which outputs a control value for controlling the motor based on the target engine speed and an actual engine speed. In a case where, when a drive mode is selected, the current target engine speed changes by an amount exceeding a predetermined judgment value according to vehicle speed, the motor control value determination section updates the current target engine speed in a stepwise manner. The resulting configuration reduces a shift shock caused by a drive mode change.

Abstract: A belt continuously variable transmission apparatus having a case which includes a power transmission case (which is part of a crankcase of an engine), a power transmission case cover, and an actuator cover assembled forwardly of the power transmission case cover (displaced forwardly on a vehicle body). The actuator cover is formed as a separate member from the power transmission case cover, and supports a motor for driving a movable part of a driving pulley. In addition, the actuator cover covers a gear system. The actuator cover is integrated with a cover of the water pump. The resulting configuration improves the assembling of the actuator cover of the belt continuously variable transmission apparatus.

Abstract: A centrifugal clutch includes a clutch weight in a plane perpendicular to a rotation axis of an input member for enabling friction fitting to an inside of a clutch housing. The clutch weight is turnably supported by a drive plate. A grooved portion is provided on a clutch weight in a position that is opposite to a drive plate. At least one end of grooved portion is closed and is formed in a turning direction of the clutch. A damping rubber supported by the drive plate abuts against an inside face of the grooved portion. The damping rubber is held in the grooved portion in a compressed state by being compressed between the drive plate and the clutch weight. The centrifugal clutch so configured effectively inhibits vibration of a clutch weight when the clutch is let in, and minimizes both the parts required and man-hours for assembly.

Abstract: A continuously variable transmission is mounted on a vehicle capable of selecting plural drive modes and changes a target engine speed between drive modes. A pulley ratio is controlled by a motor. An ECU for transmission control includes a calculation section which outputs a target engine speed as a function of throttle opening and vehicle speed, and a motor control value determination section which outputs a control value for controlling the motor based on the target engine speed and an actual engine speed. In a case where, when a drive mode is selected, the current target engine speed changes by an amount exceeding a predetermined judgment value according to vehicle speed, the motor control value determination section updates the current target engine speed in a stepwise manner. The resulting configuration reduces a shift shock caused by a drive mode change.

Abstract: The shift response in a V-belt type automatic transmission is improved using a double cogged V-belt having an endless core wire embedded portion in which core wires are embedded, a lower cog formed portion provided over the inner circumference of the core wire embedded portion, and an upper cog formed portion provided over the outer circumference of the core wire embedded portion, as a V-belt for transmitting power from a drive pulley device to a driven pulley device. Each of the core wires is formed from aramid fibers, and the ratio (W/T) of the width W of the V-belt to the thickness T of the V-belt is set to 2.5 or less.

Abstract: A belt continuously variable transmission apparatus having a case which includes a power transmission case (which is part of a crankcase of an engine), a power transmission case cover, and an actuator cover assembled forwardly of the power transmission case cover (displaced forwardly on a vehicle body). The actuator cover is formed as a separate member from the power transmission case cover, and supports a motor for driving a movable part of a driving pulley. In addition, the actuator cover covers a gear system. The actuator cover is integrated with a cover of the water pump. The resulting configuration improves the assembling of the actuator cover of the belt continuously variable transmission apparatus.

Abstract: To improve the maintainability of a vehicle by properly identifying a worn endless belt in a belt-type automatic transmission and informing a driver of the proper belt replacement interval. The belt replacement timing annunciator relies upon the radii of the endless belt wound around a drive pulley and around a driven pulley that vary to produce shifting change gear ratios. Various operating conditions and the actual change gear ratio for the specific operating condition are detected, and a comparison between a reference change gear ratio and the actual change gear ratio is made to determine if belt replacement is necessary. A timer device provides a predetermined observation interval for avoiding erroneous readings and a display is also provided for indicating the necessity of belt replacement.

Abstract: To improve the comfortability in riding by discriminating sudden acceleration upon startup before connection of a centrifugal clutch and limiting the engine output power. A supervision starting condition discrimination section discriminates whether or not an engine satisfies a supervision starting condition for starting discrimination of satisfaction of a starting control condition. The supervision starting condition is discriminated based on a vehicle speed, a throttle opening and an engine speed. Particularly, a condition at least of the engine speed from among the parameters such as the vehicle speed is set to a value lower than a speed at which a centrifugal clutch is connected.

Abstract: To improve the comfortability in riding by discriminating sudden acceleration upon startup before connection of a centrifugal clutch and limiting the engine output power. A supervision starting condition discrimination section discriminates whether or not an engine satisfies a supervision starting condition for starting discrimination of satisfaction of a starting control condition. The supervision starting condition is discriminated based on a vehicle speed, a throttle opening and an engine speed. Particularly, a condition at least of the engine speed from among the parameters such as the vehicle speed is set to a value lower than a speed at which a centrifugal clutch is connected.

Abstract: The present invention improves the maintainability of a vehicle by properly identifying a worn endless belt in a belt-type automatic transmission and informing a driver of the proper belt replacement interval. The belt replacement timing annunciator relies upon the radii of the endless belt wound around a drive pulley and around a driven pulley that vary to produce shifting change gear ratios. Various operating conditions and the actual change gear ratio for the specific operating condition are detected, and a comparison between a reference change gear ratio and the actual change gear ratio is made to determine if belt replacement is necessary. A timer device provides a predetermined observation interval for avoiding erroneous readings and a display is also provided for indicating the necessity of belt replacement.

Abstract: An engine crankshaft 2 and a wheel drive shaft 5 are connected through a static hydraulic infinitely variable transmission 3. The static hydraulic infinitely variable transmission 3 has a hydraulic pump 20 extending to an engine side of the transmission and a hydraulic motor 21 extending to a wheel drive shaft 5 side of the transmission and connected together using a closed hydraulic circuit. A control clutch 18 is fitted in the transmission system between the hydraulic motor 21 and the wheel drive shaft 5 so that the control clutch is disengaged when the engine is idling and when operation is suspended.

Abstract: A power transmission system for a snowmobile reduces the weight thereof, and allows a streamlined body to be obtained. A drive side pulley of a V-belt transmission is mounted on a right end of a crankshaft of an engine. A gear box is disposed on the right side of a driven side pulley of the V-belt transmission at a position near the driven side pulley. The driven side pulley is fastened to an input shaft. Thus, the V-belt transmission and gear box are disposed on the same right side of the engine, so that the connecting shaft for connecting the V-belt transmission to the gear box is shortened and the weight thereof is reduced. Further, the V-belt transmission and the engine are disposed between a pair of right and left main frames, and the gear box is disposed outside of the right main frame, to thereby shorten a distance between the right and left main frames.

Abstract: An automatic centrifugal clutch is arranged at the rear of an engine of a motorcycle, and a belt type continuously variable transmission and a gear type speed reduction device are arranged on opposite sides of the clutch whereby a space at the rear of the engine is effectively utilized, and a space for installing a kick starter is secured externally of the belt type continuously variable transmission. An output shaft of a reduction device and an intermediate shaft of the reduction device are arranged on opposite sides of a plane extending so as to include axes of a crankshaft and an input shaft whereby the longitudinal length of a power transmission device is shortened. An opening of a cooling air discharge passage is provided to face the automatic centrifugal clutch at the front end of the reduction device whereby the automatic centrifugal clutch can be effectively cooled while effectively utilizing the space.