Abstract: A personal watercraft can be rotated in a correct direction of rotation when the personal watercraft has been overturned, and can thereby be restored to a normal, upright position. The personal watercraft includes a vessel body, an engine, and an exhaust system. The exhaust system includes a muffler, disposed on a first side of the vessel body, and an exhaust pipe connected to the muffler and formed in an inverted U-shape. During operation of the engine, exhaust gas passes through the inverted-U-shaped exhaust pipe and is subsequently discharged to the outside environment via an exhaust port. The exhaust port is disposed on a second side of the vessel body opposite the first side. The vessel body has a hollow water-receiving portion formed therein, on the second side thereof. The water-receiving portion is adapted to be submerged under water when the personal watercraft is overturned in a body of water.

Abstract: An exhaust gate valve apparatus of a water jet propulsion-driven watercraft is provided that is capable of positively closing an exhaust port with a valve body when an engine is stationary and widely opening the valve body when the engine runs. In the watercraft, an exhaust port of a tail pipe is arranged to face an opening in a top wall of a pump chamber. The exhaust gate valve apparatus includes a valve body, valve body support flange, pressure device, and a jet water expelling device. The valve body support flange attaches the valve body to the top wall. The pressure device urges the valve body to a closed position. The jet water expelling device diverts jet water from a water jet pump and opens the valve body using the jet water thus diverted, counteracting a pressing force of the pressure device and opening the valve body.

Abstract: An exhaust system for a small-sized boat which can efficiently reduce exhaust noises in a low frequency band includes a water muffler provided at one location along exhaust pipes extending from an engine disposed in a boat body. The inside of the water muffler is divided into a single expansion chamber and a resonator chamber, and a front exhaust pipe coupled to the engine and a rear exhaust pipe opened to the outside of the boat are connected to the expansion chamber. Between the front exhaust pipe opened to the inside of the expansion chamber and the rear exhaust pipe, a water-controlling plate is provided in an upper side of the expansion chamber.

Abstract: The present invention relates to saddle-riding type watercraft and other small watercraft. In an embodiment, the invention is a small watercraft capable of reducing noise by utilizing the sponson. For example, a small watercraft is provided with a sponson made of synthetic resin, characterized in that within the sponson there has been fixed a weight matched to the frequency of the hull to thereby have a function as a dynamic damper. In an embodiment, the weight is a plate-shaped weight made of metal along the longitudinal direction of the sponson. In an embodiment, the weight is embedded in the sponson along the longitudinal direction thereof.

Abstract: A design system of an alignment mark for manufacturing a semiconductor device includes a memory which stores at least mark data including pattern information regarding plural kinds of marks and process data including condition information of manufacturing processes, and a first process simulator which simulates a substrate structure before patterning based on the process data, the substrate structure being formed in an identified manufacturing process.

Abstract: The invention is directed at increasing the degree of freedom in layout of the resonator, and the exhaust system including the resonator will be improved. Also, the invention is directed at a resonator and exhaust system wherein when an attempt is made to raise the engine speed from the idling state, the engine speed will be smoothly raised. According to the invention, there is provided a bilge pump for draining water within a hull; cooling water is caused to flow within an exhaust pipe of an engine; and in the exhaust system, there is provided a resonator. The resonator is connected to the bilge pump through bilge pipes. The bilge pump is constructed of a jet propulsion pump to be driven by the engine. Even if the resonator is arranged below the water line, the water which accumulates within the resonator will be drained by the bilge pump, and it becomes possible to arrange the resonator below the water line without interfering with the function of the resonator.

Abstract: A personal watercraft can be rotated in a correct direction of rotation when the personal watercraft has been overturned, and can thereby be restored to a normal, upright position. The personal watercraft includes a vessel body, an engine, and an exhaust system. The exhaust system includes a muffler, disposed on a first side of the vessel body, and an exhaust pipe connected to the muffler and formed in an inverted U-shape. During operation of the engine, exhaust gas passes through the inverted-U-shaped exhaust pipe and is subsequently discharged to the outside environment via an exhaust port. The exhaust port is disposed on a second side of the vessel body opposite the first side. The vessel body has a hollow water-receiving portion formed therein, on the second side thereof. The water-receiving portion is adapted to be submerged under water when the personal watercraft is overturned in a body of water.

Abstract: An exhaust gate valve apparatus of a water jet propulsion-driven watercraft is provided that is capable of positively closing an exhaust port with a valve body when an engine is stationary and widely opening the valve body when the engine runs. In the watercraft, an exhaust port of a tail pipe is arranged to face an opening in a top wall of a pump chamber. The exhaust gate valve apparatus includes a valve body, valve body support flange, pressure device, and a jet water expelling device. The valve body support flange attaches the valve body to the top wall. The pressure device urges the valve body to a closed position. The jet water expelling device diverts jet water from a water jet pump and opens the valve body using the jet water thus diverted, counteracting a pressing force of the pressure device and opening the valve body.

Abstract: The present invention relates to saddle-riding type watercraft and other small watercraft. In an embodiment, the invention is a small watercraft capable of reducing noise by utilizing the sponson. For example, a small watercraft is provided with a sponson made of synthetic resin, characterized in that within the sponson there has been fixed a weight matched to the frequency of the hull to thereby have a function as a dynamic damper. In an embodiment, the weight is a plate-shaped weight made of metal along the longitudinal direction of the sponson. In an embodiment, the weight is embedded in the sponson along the longitudinal direction thereof.

Abstract: The invention is directed at increasing the degree of freedom in layout of the resonator and the exhaust system device including the resonator will be improved. Also, the invention is directed at a resonator and exhaust system wherein when an attempt is made to raise the engine speed from the idling state, the engine speed will be smoothly raised. According to the invention, there is provided a bilge pump for draining water within a hull; cooling water is caused to flow within an exhaust pipe of an engine; and in the exhaust system, there is provided a resonator. The resonator is connected to the bilge pump through bilge pipes. The bilge pump is constructed of a jet propulsion pump to be driven by the engine. Even if the resonator is arranged below the water line, the water which accumulates within the resonator will be drained by the bilge pump, and it becomes possible to arrange the resonator below the water line without interfering with the function of the resonator.

Abstract: An exhaust system for a small-sized boat which can efficiently reduce exhaust noises in a low frequency band includes a water muffler provided at one location along exhaust pipes extending from an engine disposed in a boat body. The inside of the water muffler is divided into a single expansion chamber and a resonator chamber, and a front exhaust pipe coupled to the engine and a rear exhaust pipe opened to the outside of the boat are connected to the expansion chamber. Between the front exhaust pipe opened to the inside of the expansion chamber and the rear exhaust pipe, a water-controlling plate is provided in an upper side of the expansion chamber.

Abstract: A design system of an alignment mark for manufacturing a semiconductor device includes a memory which stores at least mark data including pattern information regarding plural kinds of marks and process data including condition information of manufacturing processes, and a first process simulator which simulates a substrate structure before patterning based on the process data, the substrate structure being formed in an identified manufacturing process.

Abstract: An exhaust system for a small watercraft wherein exhaust gas can flow smoothly includes a water muffler in the exhaust system for an engine incorporated in a small watercraft. An exhaust pipe is connected to the water muffler extending upwardly once and then extending downwardly in such a manner as to have a substantially U-shape. Spiral baffle plates are provided for spirally introducing exhaust gas on an inner face of the U-shaped exhaust pipe. Since the baffle plates are provided on the exhaust pipe, cooling water and exhaust gas can be separated from each other.

Abstract: An exhaust system for a small boat is constructed in such a manner that an exhaust pipe extends rearwardly from an engine provided in a hull of the boat. A water muffler is provided in the exhaust pipe, and exhaust gas is discharged through a water lock pipe extending upward from a water muffler. A water lock pipe has an inverted U-shape. A resonator chamber for attenuating resonance of the water lock pipe is provided in the water muffler. The resulting configuration provides an effective system for reducing exhaust noise emanating from the small boat.

Abstract: An exhaust system for a small watercraft wherein exhaust gas can flow smoothly includes a water muffler in the exhaust system for an engine incorporated in a small watercraft. An exhaust pipe is connected to the water muffler extending upwardly once and then extending downwardly in such a manner as to have a substantially U-shape. Spiral baffle plates are provided for spirally introducing exhaust gas on an inner face of the U-shaped exhaust pipe. Since the baffle plates are provided on the exhaust pipe, cooling water and exhaust gas can be separated from each other.

Abstract: To provide an exhaust structure for a jet propulsion watercraft which can simply achieve a reduction of the exhaust noise. In the exhaust structure for a jet propulsion watercraft, a water jet propeller is provided in a pump room of a watercraft body. An engine for driving the watercraft is connected to the water jet propeller. An exhaust opening of an exhaust pipe is attached to the engine and is exposed to a pump room. A resonator for sound deadening is provided for the exhaust pipe. Further, in the exhaust structure for a jet propulsion watercraft, the resonator is bent in a meandering state such that bent portions thereof are positioned adjacent to each other so that the entire resonator has a substantially flat plate-like configuration. The resonator having a plate-like configuration is laid along a ceiling wall of the pump room.

Abstract: An exhaust system for a small boat is constructed in such a manner that an exhaust pipe extends rearwardly from an engine provided in a hull of the boat. A water muffler is provided in the exhaust pipe, and exhaust gas is discharged through a water lock pipe extending upward from a water muffler. A water lock pipe has an inverted U-shape. A resonator chamber for attenuating resonance of the water lock pipe is provided in the water muffler. The resulting configuration provides an effective system for reducing exhaust noise emanating from the small boat.

Abstract: To provide an exhaust structure for a jet propulsion watercraft which can simply achieve a reduction of the exhaust noise. In the exhaust structure for a jet propulsion watercraft, a water jet propeller is provided in a pump room of a watercraft body. An engine for driving the watercraft is connected to the water jet propeller. An exhaust opening of an exhaust pipe is attached to the engine and is exposed to a pump room. A resonator for sound deadening is provided for the exhaust pipe. Further, in the exhaust structure for a jet propulsion watercraft, the resonator is bent in a meandering state such that bent portions thereof are positioned adjacent to each other so that the entire resonator has a substantially flat plate-like configuration. The resonator having a plate-like configuration is laid along a ceiling wall of the pump room.

Abstract: A braking system for a small jet propulsion surfboard can be manufactured at reduced costs. The braking system includes left and right sponsons retractably attached to a surfboard body. Left and right locking units fix the sponsons to the surfboard body. An unlocking unit unlocks the lock units in order to free the sponsons from the surfboard body. A traction rope ensures that the freed sponsons remain connected to the surfboard body. The freed sponsons are pulled by the traction rope to thereby apply braking force to the jet propulsion surfboard. In an alternative embodiment, a system with a water-reversing cup can replace the sponsons.

Abstract: An exhaust system for a jet propulsion boat and a jet propulsion boat including the exhaust system. The exhaust system includes a muffler connected to the boat's engine by an exhaust pipe, and an auxiliary muffler connected to the muffler by a first connecting portion of a connecting pipe, A second connecting portion of the connecting pipe connects the auxiliary muffler to a tail pipe, through which exhaust gases travel to be exhausted into the water through a nozzle of a jet propulsion device. The auxiliary muffler is elevated with respect to the connecting pipe, which prevents the entry of water into the auxiliary muffler and a corresponding degradation of its sound reduction capability.