Abstract: Provided is a semiconductor device capable of reducing switching loss at turn-off while suppressing conduction loss. An emitter p? layer 11, a collector p layer 23, a drift layer 10, an emitter electrode 18, a collector electrode 28, an emitter-side gate electrode 17, an emitter n layer 12, a collector p? layer 23a, a collector-side gate electrode 27, and a collector n layer 22 configure a semiconductor device 1, and a total length of a first facing region of the emitter-side gate electrode 17 in a gate width direction facing an emitter layer p? 11 via a gate insulating film 15 is longer than the total length in the gate width direction of a second facing region of a collector-side gate electrode 27 facing an impurity layer 23a via a collector-side gate insulating film 25.

Abstract: By pouring, by means of pressure, melted liquid of magnesium or magnesium alloy into a hollow portion which is formed using a casting mold, a valve body where a channel groove for hydraulic oil for use in a speed change operation of the automatic transmission is formed. In the above, the channel grove for the hydraulic oil is formed due to a convex portion which is formed on the mold so as to project into the hollow portion. As the magnesium has small heat capacity, variation of the temperature of the mold during the cooling and heating cycle can be suppressed. Moreover, as the magnesium melted liquid has no reactivity with respect to the casting mold, the convex portion is not deteriorated. This allows employment of a mold having a thinner convex portion formed thereon, and therefore formation of a valve body having a narrower channel groove.

Abstract: In a working vehicle having a tilt floor, a torsion bar has one end mounted on the tilt floor and the other end thereof mounted on a base frame, and is disposed on the tilt floor which is tilted up and down relative to the base frame. In a maximally opened position where the tilt floor is tilted up and a closed position where the tilt floor is tilted down, a position of a barycenter (G) of the tilt floor on which the driving room (C) is disposed is opposite from each other relative to a turning center of the tilt floor across the top dead center.

Abstract: There is provided a working vehicle designed such that, even in a smaller machine type, a fuel tank is easily attached or detached, overall configuration is not costly, an operating space can be increased, interior comfort is improved, and in addition, a width dimension of an opening for entry to or exit from a cabin is sufficiently secured, and satisfactory maintenance is ensured. The working vehicle comprises a cabin C which has a rear wall surface Cf having a circular arc shape formed around a rotation shaft sa of an upper rotation body 3. A planar shape formed by integrating a revolving frame R serving as a base of the upper rotation body 3, and a counterweight w fixed to the revolving frame R, is substantially the same as a planar shape of the cabin C, as viewed from above. A fuel tank having a shape along internal wall surfaces of the counterweight w is fixed to the counterweight w via pressing members.

Abstract: By pouring, by means of pressure, melted liquid of magnesium or magnesium alloy into a hollow portion which is formed using a casting mold, a valve body where a channel groove for hydraulic oil for use in a speed change operation of the automatic transmission is formed. In the above, the channel grove for the hydraulic oil is formed due to a convex portion which is formed on the mold so as to project into the hollow portion. As the magnesium has small heat capacity, variation of the temperature of the mold during the cooling and heating cycle can be suppressed. Moreover, as the magnesium melted liquid has no reactivity with respect to the casting mold, the convex portion is not deteriorated. This allows employment of a mold having a thinner convex portion formed thereon, and therefore formation of a valve body having a narrower channel groove.

Abstract: By pouring, by means of pressure, melted liquid of magnesium or magnesium alloy into a hollow portion which is formed using a casting mold, a valve body where a channel groove for hydraulic oil for use in a speed change operation of the automatic transmission is formed. In the above, the channel grove for the hydraulic oil is formed due to a convex portion which is formed on the mold so as to project into the hollow portion. As the magnesium has small heat capacity, variation of the temperature of the mold during the cooling and heating cycle can be suppressed. Moreover, as the magnesium melted liquid has no reactivity with respect to the casting mold, the convex portion is not deteriorated. This allows employment of a mold having a thinner convex portion formed thereon, and therefore formation of a valve body having a narrower channel groove.

Abstract: In a working vehicle having a tilt floor (7), the tilt floor can easily be tilted up and down. Maintenance around an engine can excellently be carried out. A torsion bar (9), which has one end mounted on the tilt floor and the other end thereof mounted on a base frame, is disposed on the tilt floor which is tilted up and down relative to the base frame. In a maximally opened position where the tilt floor is tilted up and a closed position where the tilt floor is tilted down, a position of a barycenter (G) of the tilt floor on which the driving room (C) is disposed is opposite from each other relative to a turning center of the tilt floor across the top dead center. A neutral position of the torsion bar is between the closed position and the maximally opened position.

Abstract: A line 93 is provided with a line 71 communicating the line 93 and a hydraulic oil tank 51. The line 71 is provided with a throttle 72 to construct a throttle-provided line 7. When air is trapped between the hydraulic oil tank 51 and the hydraulic pump 52, the hydraulic pump 52 is driven to discharge the air from the throttle-provided line 7 to the hydraulic oil tank 51, thereby removing the air in the hydraulic circuit 5. When the air is removed, resistance caused by the throttle 72 is increased, which makes hydraulic oil flow from a pilot pump 522 to a PPC valve. Since the throttle-provided line 7 realizes air removal with a simple structure, a hydraulic cylinder 44 can be supplied with the air-removed hydraulic oil from an initial stage, thereby enhancing responsiveness of the hydraulic cylinder 44.

Abstract: The operation control circuit of the present invention reduces the speed of an actuator, such as a rotation motor, according to reduction in the rotational speed of an engine. When the engine rotational speed is at its maximum, a pilot pressure in a pilot conduit is set to a relief pressure of a relief valve. When the engine rotational speed is reduced, the flow rate of pilot pressure hydraulic fluid decreases, and the pressure difference over a throttle section becomes smaller than the relief pressure, so that the pilot pressure is set to the pressure difference. Even if the operator operates an operation lever to a full stroke position the spool valve does not go to the fully opened state, since the pressure is low. As a result, the flow rate of hydraulic fluid supplied to the rotation motor is reduced, so that the speed of rotation is reduced.

Abstract: A line 93 is provided with a line 71 communicating the line 93 and a hydraulic oil tank 51. The line 71 is provided with a throttle 72 to construct a throttle-provided line 7. When air is trapped between the hydraulic oil tank 51 and the hydraulic pump 52, the hydraulic pump 52 is driven to discharge the air from the throttle-provided line 7 to the hydraulic oil tank 51, thereby removing the air in the hydraulic circuit 5. When the air is removed, resistance caused by the throttle 72 is increased, which makes hydraulic oil flow from a pilot pump 522 to a PPC valve. Since the throttle-provided line 7 realizes air removal with a simple structure, a hydraulic cylinder 44 can be supplied with the air-removed hydraulic oil from an initial stage, thereby enhancing responsiveness of the hydraulic cylinder 44.

Abstract: By pouring, by means of pressure, melted liquid of magnesium or magnesium alloy into a hollow portion which is formed using a casting mold, a valve body where a channel groove for hydraulic oil for use in a speed change operation of the automatic transmission is formed. In the above, the channel grove for the hydraulic oil is formed due to a convex portion which is formed on the mold so as to project into the hollow portion. As the magnesium has small heat capacity, variation of the temperature of the mold during the cooling and heating cycle can be suppressed. Moreover, as the magnesium melted liquid has no reactivity with respect to the casting mold, the convex portion is not deteriorated. This allows employment of a mold having a thinner convex portion formed thereon, and therefore formation of a valve body having a narrower channel groove.

Abstract: A work vehicle cooling system comprises a cooling fan (18) driven by the output from an engine (16), and a flow path for allowing an airflow (27) generated by the cooling fan (18) to be flown between the engine (16) and an operator's seat (14) without having passed through any of a radiator (20) and an oil cooler (21) for the engine (16). With this simple configuration, the heat generated by the engine (16) is prevented from being transmitted to the operator's seat (14).

Abstract: A work vehicle cooling system comprises a cooling fan (18) driven by the output from an engine (16), and a flow path for allowing an airflow (27) generated by the cooling fan (18) to be flown between the engine (16) and an operator's seat (14) without having passed through any of a radiator (20) and an oil cooler (21) for the engine (16). With this simple configuration, the heat generated by the engine (16) is prevented from being transmitted to the operator's seat (14).