Yamaha Hatsudoki Kabushiki Kaisha

Seiji Sawai

Takashi Imamura

Yutaka Yamazaki

Atsushi Yasuda

Masahiro Yoshida

Katsuhiro Kondou

Masahiro Satou

Kenta Higashiyama

Masahide Shimbori

Kazunari Takata

Kouji Sakai

Koji Kobayashi

Kunihiko Nakajima

Chisei Asami

Keijiro Ota

Jiro Watase

A front suspension structure of a vehicle where an appropriate locus of a front wheel when going over undulating ground, an arm span, and an arm length can be secured. Left and right first arms are rotatable about a rotation axis extending forward and obliquely toward a center in a left-right direction in a plan view and passing through two proximal parts. A frame front section has left and right front coupling parts to which proximal parts of front rods of left and right upper arms are coupled respectively. A distance between the left and right front coupling parts is smaller than a width in a left-right direction of a housing of a differential gear.

Vehicle

A vehicle that can reduce change in the toe angle of a rear wheel in a toe-out direction at the time of a braking force being provided by the vehicle. A coupling point between a vehicle frame and a trailing arm is defined as a first coupling point. A coupling point between the trailing arm and a lateral arm is defined as a second coupling point. A coupling point between the lateral arm and a frame rear section is defined as a third coupling point. A straight line connecting the first coupling point and the second coupling point is defined as a first straight line. A straight line connecting the second coupling point and the third coupling point is defined as a second straight line. With those definitions, an angle between the first straight line and the second straight line in a plan view of the vehicle is 90 degrees or greater.

A shock absorber includes a cylinder and a piston. The piston is configured to partition an internal space of the cylinder into two oil chambers and is capable of sliding in an axial direction of the cylinder. The piston having formed therethrough a communication path configured to bring the two oil chambers into communication with each other. The shock absorber also includes a first rod and a second rod. The first rod extends in a first direction of the axial direction with respect to the piston. The second rod has a diameter larger than a diameter of the first rod, and extends in a second direction of the axial direction, which is opposite to the first direction, with respect to the piston. The shock absorber further includes a rod mounting member, which is provided on the first rod, and a cylinder mounting member, which is provided on the cylinder and arranged as offset from an axis of the cylinder.

Shock absorber, vehicle, and snowmobile

A straddle-type vehicle includes a vehicle body frame; a power unit supported by the vehicle body frame; a seat mounted at a position higher than the power unit; a handle bar mounted at a position more forward than the seat; a pair of front wheels spaced apart from each other in a vehicle width direction; a pair of suspensions spaced apart from each other in the vehicle width direction and connecting the pair of front wheels to the vehicle frame; and a vehicle body vibration control damper including end portions connected to a first attachment portion and a second attachment portion, respectively, mounted on the vehicle body frame so as to be spaced apart from each other in a vehicle front-back direction, and mounted so as to extend in the vehicle front-back direction with at least a portion thereof located between the pair of suspensions.

Straddle-type vehicle

An oil channel that connects a right damper and a left damper includes a switching valve arranged between a right oil channel ER and a left oil channel EL. The switching valve includes a valve main body in which a first switching channel is formed for connecting the right oil channel ER and the left oil channel EL. The valve main body is rotatable to a first position where the first switching channel connects the right oil channel ER and the left oil channel EL to each other and to a second position different from the first position. According to this damping system, it is possible to adjust oil flow in the oil channel by performing a simple operation for the switching valve.

Vehicle damping system and vehicle

Various embodiments of a snowmobile are disclosed. The lower arm is arranged below the upper arm. The lower arm includes proximal portions and connected to the ski support frame. The lower arm extends outwardly from the proximal portions and in the vehicle width direction and connects the ski support frame and the ski. The proximal portions and of the lower arm are positioned higher than the lower end of the engine. At least a portion of the lower arm is positioned higher than the rotational center of the crank shaft. This structure can prevent the center of gravity of the vehicle body from becoming high and reduce running resistance when the vehicle traveling in deep snow.

Snowmobile

This specification relates to a snowmobile. Each of the right suspension and the left suspension includes a damper capable of expanding and contracting according to the vertical movement of the lower arm and a spring that exerts spring force in the expansion/contraction direction of the damper. The cylinder of the right damper and the cylinder of the left damper are connected to each other through a hydraulic fluid channel so that the hydraulic fluid flows between the cylinder of the right damper and the cylinder of the left damper. This snowmobile can reduce the difference in contact pressure on snow surface between the left ski and the right ski, when the vehicle turns.

The present specification relates to a snowmobile. The upper arm includes two proximal portions connected to the vehicle frame and the upper arm extends outwardly from the two proximal portions in the vehicle width direction and the upper arm is connected to the knuckle. The two proximal portions are rotatable so that the knuckle and the skis can move up and down relative to the vehicle frame. The axis Ax, passing through the rotation center Cof the two proximal portions of the upper arm, goes through a position of the rotation center of the secondary shaft or through a position above the rotation center of the secondary shaft. This structure can reduce the force acting on the vehicle body frame via the upper arm and prevent an increase in the force.

A snowmobile includes a transmission unit that transmits a driving force generated by an engine to the ground surface, in which ground touching portions of the transmission unit that are spaced apart from each other in the vehicle width direction receive reaction forces mutually different in magnitude from the ground surface; a suspension that supports the transmission unit so as to swing in the up-down direction; and a vehicle body vibration control damper extending between a first portion and a second portion that are spaced apart from each other of the vehicle body frame and a member fixed to the vehicle body frame, the vehicle body vibration control damper generating a damping force against variations that change the distance between the first portion and the second portion.

A first hydraulic damper includes one end portion attached to a first attachment position of a vehicle body. A second hydraulic damper includes one end portion coupled to the other end portion of the first hydraulic damper via a linking member, and the other end portion attached to a second attachment position of the vehicle body. Each of the first and second hydraulic dampers includes a hydraulic cylinder, a piston, a piston rod, a free piston, a compression coil spring, first and second working oil passages to cause first and second oil chambers to communicate with each other, and working oil passage throttles. The first hydraulic damper, second hydraulic damper, and the linking member are coupled in the longitudinal direction. One of the hydraulic cylinder and piston rod is attached to the vehicle body, and the other is coupled to the linking rod.

Vibration damping device for vehicle body

A vehicle includes a vehicle body frame, a power unit supported by the vehicle body frame, a steering system supported by the vehicle body frame, a pair of driving wheels spaced apart from each other in a vehicle width direction, a transmission unit that transmits a driving force generated by the power unit to the pair of driving wheels and causes the pair of driving wheels to always rotate at the same rotation speed, and a vehicle body vibration control damper extending between a first portion and a second portion spaced apart from each other, each of the first portion and the second portion being located on the vehicle body frame or a member fixed to the vehicle body frame, and generating a damping force relative to the vibration that changes a distance between the first portion and the second portion.

A spring structure includes a clockwise spring and a counterclockwise spring that are coaxially arranged under a state in which a spring seat is interposed between a lower end portion of the clockwise spring and an upper end portion of the counterclockwise spring. An upper end portion of the clockwise spring is supported on an upper spring seat portion, and a lower end portion of the counterclockwise spring is supported on a lower spring seat portion.

Spring structure

In a shock absorber of a vehicle, when a moving speed of a piston rod in relation to a cylinder tube is slow and first and second input forces are externally applied to the shock absorber, damping forces of pressure side and extension side first damping force generating devices are larger than that of pressure side and extension side second damping force generating devices. On the other hand, when the moving speed is fast, the damping forces of the pressure side and the extension side second damping force generating devices are larger than that of the pressure side and the extension side first damping force generating devices. A gas enclosure chamber filled with gas is connected to a first chamber through a free piston.

Hydraulic shock absorber

A damper includes a cylinder tube having a first end connected to one portion of a member of an object for damping, and a fixing rod guide arranged to close a second end of the cylinder tube; a movable rod guide fitted on the first end of the cylinder tube; a main piston rod extending from the piston side, the piston fitted in the cylinder tube and passing through the fixing rod guide; a sub-piston rod extending on the piston side and passing through the movable rod guide; and a spring normally biasing the movable rod guide toward the piston. A damping force generation oil passage is arranged to connect first and second oil chambers in a cylinder tube defined by the piston. The number of parts of a through-rod type damper is reduced to simplify a construction thereof and to make the damper compact.

Growing community of inventors

Shizuoka, Japan

Seiji Sawai