Abstract: To make an electrically-operated power steering unit less susceptible to influence of change in a positional relationship between supporting sections respectively at the two ends of the electrically-operated power steering unit. A gear case included in a electrically-operated power steering unit is attached to the lower section of a vehicle body frame, and the lower end portion of a steering shaft is rotatably supported by a housing annexed to the gear case with an upper bearing interposed in between, in a vehicle in which an input shaft provided to the electrically-operated power steering unit is linked to the lower end portion of the steering shaft, and in which an output shaft provided to the electrically-operated power steering unit is rotatably supported by the lower section of a vehicle body.

Abstract: To provide a layout structure for a motor-driven power steering unit controller configured to take into account the water level at which submergence of the vehicle is expected to occur. In a vehicle including a steering shaft rotatably supported on a vehicle body frame, a steering bar handle attached to the upper end of the steering shaft, a motor-driven power steering unit mounted onto the lower end of the steering shaft, and at least two front wheels, a controller for controlling the motor-driven power steering unit is laid out on the front side relative to the steering shaft and above a horizontal line indicative of the submergence limit of the vehicle.

Abstract: A weight balance of a vehicle body is provided in an all terrain vehicle wherein an engine is supported by a vehicle body frame and an electric power steering device having an actuator unit is provided on a steering shaft. An electric motor is provided in the actuator unit, and heavy objects including a battery and a muffler are disposed on an opposite side to the electric motor in a vehicle width direction with respect to a vehicle body centerline extending in a longitudinal direction of the vehicle and on an opposite side to the electric motor in the longitudinal direction of the vehicle with respect to the engine. To shorten and reduce weight the steering shaft is supported on a vehicle body frame through a radial bearing and ball bearings. Of the plurality of bearings, at least one of the bearings is made self-aligning.

Abstract: A structure for attaching an electrically-operated power steering apparatus for a vehicle. The structure includes a body frame, more specifically, sub slant frames having respective motor brackets for supporting an actuator unit. The motor brackets have bolts that fasten the actuator unit, and the bolts extend perpendicularly to a steering shaft. With this configuration, the structure is not affected by a manufacturing error of a body frame and other parts of the vehicle. Further, the structure takes account of a direction in which fastening means is tightened.

Abstract: To constrain a load applied to a steering shaft and a power assist unit. In a rough terrain vehicle including a power assist unit including an electrically-driven power steering apparatus provided coaxially with a steering shaft, and an electrically-driven motor provided in the power assist unit arranged so as to be orthogonal to the steering shaft, a rear end portion of the electrically-driven motor is supported by a motor supporting member which is mounted to inclined frames of a vehicle body frame.

Abstract: To provide a power steering system for an all-terrain vehicle in which a control unit can be favorably protected from water, mud or the like coming from the ground surface at the time of operating of the vehicle on rough terrain or the like. In a power steering system for a saddle ride type four-wheel vehicle in which a rotary shaft of a power assist motor is disposed at right angles to a steering shaft and is inclined so that its upper portion is located on the rear side, a control unit for controlling the power assist motor is disposed on the upper side relative to a meshed portion between the power assist motor and the steering shaft.

Abstract: An exhaust muffler system for use on a motorcycle or four-wheeled vehicle provides for operation in either of two modes, a regular configuration that provides a high degree of noise reduction, or a racing specification that provides for a freer-flowing exhaust. Without changing the main body of the muffler, an operator can choose between a quieter, public road setting or a louder, high performance setting. The muffler is provided with two interchangeable spark arresters, and a main body having multiple expansion chambers therein, defined by bulkheads. When a regular spark arrester is installed, exhaust gas passes through one bulkhead three times, greatly reducing the noise produced. With the spark arrester removed, the exhaust gas passes straight through to the open air, enhancing performance. A seal is provided between the bulkheads and the spark arrester, which provides for extension or retraction in the lengthwise direction of the tail pipe.

Abstract: An exhaust muffler system for use on a motorcycle or four-wheeled vehicle provides for operation in either of two modes, a regular configuration that provides a high degree of noise reduction, or a racing specification that provides for a freer-flowing exhaust. Without changing the main body of the muffler, an operator can choose between a quieter, public road setting or a louder, high performance setting. The muffler is provided with two interchangeable spark arresters, and a main body having multiple expansion chambers therein, defined by bulkheads. When a regular spark arrester is installed, exhaust gas passes through one bulkhead three times, greatly reducing the noise produced. With the spark arrester removed, the exhaust gas passes straight through to the open air, enhancing performance. A seal is provided between the bulkheads and the spark arrester, which provides for extension or retraction in the lengthwise direction of the tail pipe.

Abstract: A high-performance exhaust silencer in which a shell wall includes a shell outer plate, a shell inner plate, and a damping material to be inserted therebetween. A space between the shell outer plate and shell inner plate of the exhaust silencer is narrowed and the shell outer plate and the shell inner plate will not interfere with each other. An outer shape of the exhaust silencer is small but the expansion chambers are large by providing an air space between the shell outer plate and the shell inner plate. For the above-mentioned damping material, a material obtained by stretchably weaving metal wire into mesh is used.

Abstract: An exhaust emission control system of an internal combustion engine capable of post injection is disclosed which provides control such that the injection timing in sub injection is set to a point earlier than the target injection timing when the sub injection is started, and the injection timing in the sub injection is then delayed to the target injection timing. This realizes the post injection under the optimum conditions and enables an efficient rise in the exhaust temperature while inhibiting deterioration of the drivability due to a rapid change in torque.

Abstract: An exhaust emission control system of an internal combustion engine is provided which controls the oxygen concentration of exhaust passing through the exhaust emission control device according to the flow rate of exhaust flowing through an exhaust passage when the exhaust emission control device is regenerated, so that the regeneration is completed within a short period of time while the filter is prevented from being damaged by melting during the regeneration. This improves the exhaust emission control performance and reliability of the filter.

Abstract: An exhaust emission control system of an internal combustion engine is provided which controls the oxygen concentration of exhaust passing through the exhaust emission control device according to the flow rate of exhaust flowing through an exhaust passage when the exhaust emission control device is regenerated, so that the regeneration is completed within a short period of time while the filter is prevented from being damaged by melting during the regeneration. This improves the exhaust emission control performance and reliability of the filter.

Abstract: An exhaust emission control system of an internal combustion engine capable of post injection is disclosed which provides control such that the injection timing in sub injection is set to a point earlier than the target injection timing when the sub injection is started, and the injection timing in the sub injection is then delayed to the target injection timing. This realizes the post injection under the optimum conditions and enables an efficient rise in the exhaust temperature while inhibiting deterioration of the drivability due to a rapid change in torque.