Abstract: A power transmitting device includes a first rotor and a second rotor rotatably disposed coaxially with a rotational central axis and in facing relation to each other. A first pressing protrusion projecting from the first rotor and a second pressing protrusion projecting from the second rotor are disposed in relative positions on superposed rotation trajectories. A soft rubber member elastically deformable to a large extent and has a small modulus of elasticity and a hard rubber member elastically deformable to a small extent and has a large modulus of elasticity are interposed between the first and second pressing protrusions. While no relative torque load is being applied to the first and second rotors, the soft rubber member is held in contact with both the first and second pressing protrusions, and the hard rubber member is interposed between the first pressing protrusion and the second pressing protrusion with gaps therebetween.

Abstract: A power transmitting device includes a first rotor and a second rotor rotatably disposed coaxially with a rotational central axis and in facing relation to each other, a single arc spring that is elastically deformable to a large extent and has a small modulus of elasticity, the arc spring being interposed between the first rotor and the second rotor for urging the first rotor and the second rotor to opposite sides in a ration direction, a first pressing protrusion projecting from the first rotor and a second pressing protrusion projecting from the second rotor, the first pressing protrusion and the second pressing protrusion being disposed in relative positions on superposed rotation trajectories, and a rubber member that is elastically deformable to a small extent and has a large modulus of elasticity, the rubber member being interposed between the first pressing protrusion and the second pressing protrusion with gaps therebetween.

Abstract: A power transmitting device includes a first rotor and a second rotor rotatably disposed coaxially with a rotational central axis and in facing relation to each other. A first pressing protrusion projecting from the first rotor and a second pressing protrusion projecting from the second rotor are disposed in relative positions on superposed rotation trajectories. A soft rubber member elastically deformable to a large extent and has a small modulus of elasticity and a hard rubber member elastically deformable to a small extent and has a large modulus of elasticity are interposed between the first and second pressing protrusions. While no relative torque load is being applied to the first and second rotors, the soft rubber member is held in contact with both the first and second pressing protrusions, and the hard rubber member is interposed between the first pressing protrusion and the second pressing protrusion with gaps therebetween.

Abstract: A power transmitting device includes a first rotor and a second rotor rotatably disposed coaxially with a rotational central axis be and in facing relation to each other, a single arc spring that is elastically deformable to a large extent and has a small modulus of elasticity, the arc spring being interposed between the first rotor and the second rotor for urging the first rotor and the second rotor to opposite sides in a ration direction, a first pressing protrusion projecting from the first rotor and a second pressing protrusion projecting from the second rotor, the first pressing protrusion and the second pressing protrusion being disposed in relative positions on superposed rotation trajectories, and a rubber member that is elastically deformable to a small extent and has a large modulus of elasticity, the rubber member being interposed between the first pressing protrusion and the second pressing protrusion with gaps therebetween.

Abstract: A valve operating apparatus for use in an internal combustion engine includes an intake cam 38, an intake rocker arm 33 rotatable about a rotational shaft 35 and driven by the intake cam 38, and an intake valve 40 pushed by a pusher 70 of the intake rocker arm 33, the internal combustion engine has a cylinder assembly 12L lying horizontally, and the intake rocker arm 33 has a weight 67 adjusting the center of gravity of the rocker arm 33 to position the pusher 70 above the rotational shaft 35 while the intake cam 38 is held out of abutting contact with the intake rocker arm 33.

Abstract: A valve operating apparatus for use in an internal combustion engine includes an intake cam 38, an intake rocker arm 33 rotatable about a rotational shaft 35 and driven by the intake cam 38, and an intake valve 40 pushed by a pusher 70 of the intake rocker arm 33, the internal combustion engine has a cylinder assembly 12L lying horizontally, and the intake rocker arm 33 has a weight 67 adjusting the center of gravity of the rocker arm 33 to position the pusher 70 above the rotational shaft 35 while the intake cam 38 is held out of abutting contact with the intake rocker arm 33.

Abstract: A vehicle is disclosed with a seating assembly which is capable of prompting an occupant to take an appropriate riding posture depending on the behavior of the vehicle body. A motorcycle includes tilting mechanisms for tilting seating surfaces of a front seat (rider seating part) and a rear seat (passenger seating part) and an ECU carries out a control process for tilting the seating surfaces to lift rear portions of the seats upwardly in response to an action to accelerate the motorcycle and a control process for tilting the seating surfaces to lift front portions of the seats upwardly in response to an action to decelerate the motorcycle.

Abstract: To elongate an exhaust tail pipe wherein a muffler is covered by a rear cowl. An exhaust structure of a vehicle including a rear cowl covering a vehicle rear portion, a rear bank-muffler including a first and second expansion chamber partitioned by a partition, a first and second connecting pipe connecting the expansion chambers, and a tail pipe configured to discharge exhaust air from the rear bank-muffler. The rear bank-muffler is covered by the rear cowl, wherein outlines of the rear bank-muffler and the rear cowl are each formed such that the width decreases toward the vehicle rear. The tail pipe, the first connecting pipe, and the second connecting pipe are provided so as to penetrate the partition. A position where the tail pipe penetrates the partition and positions where the first connecting pipe and second connecting pipe penetrate the partition are offset from each other in the vertical direction.

Abstract: To elongate an exhaust tail pipe wherein a muffler is covered by a rear cowl. An exhaust structure of a vehicle including a rear cowl covering a vehicle rear portion, a rear bank-muffler including a first and second expansion chamber partitioned by a partition, a first and second connecting pipe connecting the expansion chambers, and a tail pipe configured to discharge exhaust air from the rear bank-muffler. The rear bank-muffler is covered by the rear cowl, wherein outlines of the rear bank-muffler and the rear cowl are each formed such that the width decreases toward the vehicle rear. The tail pipe, the first connecting pipe, and the second connecting pipe are provided so as to penetrate the partition. A position where the tail pipe penetrates the partition and positions where the first connecting pipe and second connecting pipe penetrate the partition are offset from each other in the vertical direction.

Abstract: A motorcycle includes a step operating mechanism that changes the position of pillion steps (passenger steps), and an electronic control unit carries out step inclining control to change the position of the pillion steps, so that footrest surfaces of the pillion steps may each become an inclined surface, in which the steps are pivotally raised such that a portion of the passenger step situated at the vehicle body outside is raised toward the vehicle body upper side relative to a portion of the passenger step situated at the vehicle body inside, in response to at least one of an acceleration operation, a deceleration operation, and a turn operation of the motorcycle. Such arrangement provides a vehicle that can induce an occupant to take a riding posture suitable for the traveling status of the vehicle.

Abstract: A vehicle is disclosed with a seating assembly which is capable of prompting an occupant to take an appropriate riding posture depending on the behavior of the vehicle body. A motorcycle includes tilting mechanisms for tilting seating surfaces of a front seat (rider seating part) and a rear seat (passenger seating part) and an ECU carries out a control process for tilting the seating surfaces to lift rear portions of the seats upwardly in response to an action to accelerate the motorcycle and a control process for tilting the seating surfaces to lift front portions of the seats upwardly in response to an action to decelerate the motorcycle.

Abstract: A motorcycle includes a step operating mechanism that changes the position of pillion steps (passenger steps), and an electronic control unit carries out step inclining control to change the position of the pillion steps, so that footrest surfaces of the pillion steps may each become an inclined surface, in which the steps are pivotally raised such that a portion of the passenger step situated at the vehicle body outside is raised toward the vehicle body upper side relative to a portion of the passenger step situated at the vehicle body inside, in response to at least one of an acceleration operation, a deceleration operation, and a turn operation of the motorcycle. Such arrangement provides a vehicle that can induce an occupant to take a riding posture suitable for the traveling status of the vehicle.

Abstract: A dog-clutch transmission system having dog-clutches is provided that can effectively lower the sound resulting from the engagement of dogs during the meshing of gears. A dog-clutch transmission system includes first gears installed adjacent to each other on respective shafts so as not to be rotatable relatively to the respective shafts and to be axially slidable; and second gears installed so as to be rotatable relatively to the respective shafts and not to be axially slidable. Each of the first gears has dog-teeth projecting in the axial direction and each of the other gears has dog-holes recessed in the axial direction. Speed-stages are switchable by bringing the dog-teeth and the dog-holes into engagement and disengagement. A speed-change ratio proportion of a change-speed ratio at an arbitrary n-speed speed-stage to a speed-change ratio at a (n+1)-speed speed-stage is set at 0.725 or more.

Abstract: A crankcase of an internal combustion engine includes protruding portions formed on an outer surface of the crankcase which are constituted of a pair of left and right wall members, and a vibration isolating rubber is fitted between the wall members. The crankcase configured in this manner prevents the generation of sounds from a protruding portion of the crankcase and is light-weight.

Abstract: To provide a multiple disc clutch in which the engagement/disengagement timing of the clutch can be adjusted to a fixed value, and an assembling method for the multiple disc clutch. Two kinds of clutch discs different at least in thickness are combined, and the clutch disc or discs are replaced with the clutch disc or discs of other thickness so that the total thickness of a required number of the combined clutch discs when a predetermined pressure is applied thereto will be equal to a predetermined size, whereby the total thickness is adjusted.

Abstract: A dog-clutch transmission system having dog-clutches is provided that can effectively lower the sound resulting from the engagement of dogs during the meshing of gears. A dog-clutch transmission system includes first gears installed adjacent to each other on respective shafts so as not to be rotatable relatively to the respective shafts and to be axially slidable; and second gears installed so as to be rotatable relatively to the respective shafts and not to be axially slidable. Each of the first gears has dog-teeth projecting in the axial direction and each of the other gears has dog-holes recessed in the axial direction. Speed-stages are switchable by bringing the dog-teeth and the dog-holes into engagement and disengagement. A speed-change ratio proportion of a change-speed ratio at an arbitrary n-speed speed-stage to a speed-change ratio at a (n+1)-speed speed-stage is set at 0.725 or more.

Abstract: A saddle-type vehicle includes a passenger step member, a brake pedal, a step holder having the passenger step member and the brake pedal mounted thereon, and a master cylinder adapted to convert a tread force from the brake pedal into brake pressure. The master cylinder is mounted on a support bracket, which is separate from the step holder. The support bracket and the step holder are temporarily assembled with each other, and are co-fastened to a vehicle body frame of the vehicle such that a gap is formed between the support bracket and the step holder. During operation of the vehicle, such configuration of the support bracket and the step holder having the gap formed therebetween minimizes transmission of vibration from the support bracket to the step holder.

Abstract: A crankcase of an internal combustion engine includes protruding portions formed on an outer surface of the crankcase which are constituted of a pair of left and right wall members, and a vibration isolating rubber is fitted between the wall members. The crankcase configured n this manner prevents the generation of sounds from a protruding portion of the crankcase and is light-weight.

Abstract: To provide a multiple disc clutch in which the engagement/disengagement timing of the clutch can be adjusted to a fixed value, and an assembling method for the multiple disc clutch. Two kinds of clutch discs different at least in thickness are combined, and the clutch disc or discs are replaced with the clutch disc or discs of other thickness so that the total thickness of a required number of the combined clutch discs when a predetermined pressure is applied thereto will be equal to a predetermined size, whereby the total thickness is adjusted.

Abstract: A muffler for efficiently reducing noise. Front side exhaust pipes and rear side exhaust pipes extend from front cylinders and rear cylinders, respectively, of a V-type water-cooled 4-cylinder engine and are operatively connected to a catalyst chamber disposed below a crankcase. The catalyst chamber is connected to an exhaust chamber located to the rear thereof in which exhaust gas is expanded. An outlet pipe laterally projects from a lateral surface of a rear end portion of the exhaust chamber and is connected to a front pipe projecting from the lateral surface of the front portion of a muffler. The front pipe is transversely inserted into the muffler to increase a cross-section ratio, thereby efficiently reducing noise.