Abstract: First hydraulic-pressure supply piping extended from an accumulator is connected to a first supply port (that is, to a second pressure chamber) of a cylinder, and to second hydraulic-pressure delivery piping of an ABS via third hydraulic-pressure supply piping having a third linear valve. When the braking hydraulic pressure Pf is reduced in the ABS, the degree and the period of time that the third linear valve is opened are set according to the amount of fluid discharged from the second hydraulic-pressure delivery piping to a reservoir tank through a pressure-reducing valve so that a certain amount of fluid is returned from the first hydraulic-pressure supply piping to the second hydraulic-pressure delivery piping via the third hydraulic-pressure supply piping.

Abstract: A driving device of the invention has a clutch 40 and a continuously variable transmission 50. The clutch 40 couples and decouples a rotating shaft 24 or an output shaft of a motor 30 with and from a driveshaft 22. The continuously variable transmission 50 has an input shaft connected to the rotating shaft 24 and an output shaft connected to the driveshaft 22 via a gear mechanism 52. A spring 36 is attached to a rotor 31 of the motor 30 to apply a pressing force and cause the clutch 40 to couple the rotating shaft 24 with the driveshaft 22 in response to a relatively small output torque of the motor 30. With an increase in output torque of the motor 30, a thrust force produced in the motor 30 moves the rotating shaft 24 against the pressing force of the spring 36 to cause the clutch 40 to decouple the rotating shaft 24 from the driveshaft 22. The output torque of the motor 30 is then transmitted to the driveshaft 22 with a gear change of the continuously variable transmission 50.

Abstract: There are provided a NOx storage reduction catalyst which is provided in an exhaust passage for an engine, and a sulfur concentration sensor which can detect a total concentration of SOx and H2S in exhaust gas that has passed through the NOx catalyst, and a concentration of SOx in the exhaust gas. An operating state of the engine is controlled such that SOx is released from the NOx catalyst (sulfur poisoning recovery process). When a concentration of the hydrogen sulfide obtained based on the total concentration and the concentration of SOx that are detected by the sulfur concentration sensor during the sulfur poisoning recovery process exceeds a permissible limit, an operating state of the engine is controlled such that the sulfur oxide is released from the NOx catalyst, an amount of the released sulfur oxide is in a predetermined range, and the concentration of the hydrogen sulfide is reduced.

Abstract: A two-stroke engine having an intake valve and an exhaust valve which are arranged on the cylinder head. A masking wall is formed on the inner wall of the cylinder head to mask the valve opening between the valve seat and the peripheral portion of the intake valve, which is located on the exhaust valve side, for the entire time for which the intake valve is open. Due to the masking wall, fresh air fed into the cylinder is turned around a central axis perpendicular to the axis of the cylinder. A fuel injector is arranged on the inner wall of the cylinder on the central axis to inject fuel therefrom along the central axis.