Abstract: A hydraulic controller includes an actuator for electrically controlling the hydraulic pressure, a hydraulic-pressure sensing part for sensing an actual value of the hydraulic pressure in the actuator, and an ECU for controlling the actuator.

Abstract: A double piston and belt type continuously variable transmission comprises a primary pulley provided with a primary piston chamber and a primary clamp chamber; a secondary pulley provided with a secondary piston chamber and a secondary clamp chamber; and an endless belt operatively put around the primary and secondary pulleys. A switching circuit is arranged to connect both the primary and secondary clamp chambers to either one of the primary and secondary piston chambers, which shows a higher hydraulic pressure than the other.

Abstract: A hydraulic control apparatus of a belt-drive CVT, controlling a transmission ratio by changing respective effective rotation radii of driving and driven pulleys, includes vehicle information sensors; hydraulic actuators changing the respective rotation radii; and a control unit determining each fluid pressure command value provided for the pulleys, and controlling the hydraulic actuators based on the fluid pressure command values. The control unit acquires an actual displacement amount of one of the pulleys. When changing a transmission to the highest or lowest speed transmission, the control unit sets a target displacement amount of one of the pulleys; estimates a rapidly changing amount of the working fluid pressure, occurring at close to an end of the speed change; and corrects the fluid pressure command value by the rapidly changing amount at a time when a rate of the actual displacement amount with respect to the target displacement amount has reached a predetermined rate ?0.

Abstract: A hydraulic pressure control apparatus of a belt-drive continuously variable transmission (CVT) for an automotive vehicle, includes a vehicular information detector that detects engine-and-vehicle operating conditions and a hydraulic actuator that regulates primary and secondary pulley pressures. A CVT control unit calculates a primary-pulley slip-limit pulley thrust and a secondary-pulley slip-limit pulley thrust based on information about the engine-and-vehicle operating conditions. The CVT control unit sets a primary-pulley-thrust command value to the primary-pulley slip-limit pulley thrust and calculates a desired secondary pulley thrust based on a desired transmission ratio, when a pulley ratio is greater than or equal to 1. The CVT control unit sets a secondary-pulley-thrust command value to the secondary-pulley slip-limit pulley thrust and calculates a desired primary pulley thrust suited to the desired transmission ratio, when the pulley ratio is less than 1.

Abstract: A system for controlling an automatic transmission includes a start clutch, an engagement element arranged in series to the start clutch and engaged during vehicle driving, and an ECU for controlling the start clutch and the engagement element, wherein the ECU is programmed to select, at vehicle start, one of the start clutch and the engagement element in accordance with one of the oil temperature within the transmission and the throttle-valve opening.

Abstract: A hydraulic control apparatus of a belt-drive CVT, controlling a transmission ratio by changing respective effective rotation radii of driving and driven pulleys, includes vehicle information sensors; hydraulic actuators changing the respective rotation radii; and a control unit determining each fluid pressure command value provided for the pulleys, and controlling the hydraulic actuators based on the fluid pressure command values. The control unit acquires an actual displacement amount of one of the pulleys. When changing a transmission to the highest or lowest speed transmission, the control unit sets a target displacement amount of one of the pulleys; estimates a rapidly changing amount of the working fluid pressure, occurring at close to an end of the speed change; and corrects the fluid pressure command value by the rapidly changing amount at a time when a rate of the actual displacement amount with respect to the target displacement amount has reached a predetermined rate ?0.

Abstract: There is provided a start clutch control system for a vehicle, including a start clutch disposed between an engine and a transmission in the vehicle, a detection unit that detects vehicle running conditions including at least a vehicle speed, and a control unit that controls engagement and disengagement of the start clutch according to the detected vehicle running conditions. The control unit has a target torque determining section to determine a target torque transmitted by the start clutch with reference to the vehicle running conditions, a torque transmission characteristic setting section to set a transmission characteristic of the target torque differently depending on the vehicle speed, a phase compensating section to make a phase compensation for the torque transmission characteristic based on actual and target mathematical models of the vehicle, and a clutch control section to control the start clutch according to the phase-compensated torque transmission characteristic.

Abstract: A double piston and belt type continuously variable transmission comprises a primary pulley provided with a primary piston chamber and a primary clamp chamber; a secondary pulley provided with a secondary piston chamber and a secondary clamp chamber; and an endless belt operatively put around the primary and secondary pulleys. A switching circuit is arranged to connect both the primary and secondary clamp chambers to either one of the primary and secondary piston chambers, which shows a higher hydraulic pressure than the other.

Abstract: A hydraulic pressure control apparatus of a belt-drive continuously variable transmission (CVT) for an automotive vehicle, includes a vehicular information detector that detects engine-and-vehicle operating conditions and a hydraulic actuator that regulates primary and secondary pulley pressures. A CVT control unit calculates a primary-pulley slip-limit pulley thrust and a secondary-pulley slip-limit pulley thrust based on information about the engine-and-vehicle operating conditions. The CVT control unit sets a primary-pulley-thrust command value to the primary-pulley slip-limit pulley thrust and calculates a desired secondary pulley thrust based on a desired transmission ratio, when a pulley ratio is greater than or equal to 1. The CVT control unit sets a secondary-pulley-thrust command value to the secondary-pulley slip-limit pulley thrust and calculates a desired primary pulley thrust suited to the desired transmission ratio, when the pulley ratio is less than 1.

Abstract: A system for controlling an automatic transmission includes a start clutch, an engagement element arranged in series to the start clutch and engaged during vehicle driving, and an ECU for controlling the start clutch and the engagement element, wherein the ECU is programmed to select, at vehicle start, one of the start clutch and the engagement element in accordance with one of the oil temperature within the transmission and the throttle-valve opening.

Abstract: A hydraulic controller includes an actuator for electrically controlling the hydraulic pressure, a hydraulic-pressure sensing part for sensing an actual value of the hydraulic pressure in the actuator, and an ECU for controlling the actuator.

Abstract: There is provided a start clutch control system for a vehicle, including a start clutch disposed between an engine and a transmission in the vehicle, a detection unit that detects vehicle running conditions including at least a vehicle speed, and a control unit that controls engagement and disengagement of the start clutch according to the detected vehicle running conditions. The control unit has a target torque determining section to determine a target torque transmitted by the start clutch with reference to the vehicle running conditions, a torque transmission characteristic setting section to set a transmission characteristic of the target torque differently depending on the vehicle speed, a phase compensating section to make a phase compensation for the torque transmission characteristic based on actual and target mathematical models of the vehicle, and a clutch control section to control the start clutch according to the phase-compensated torque transmission characteristic.

Abstract: There is provided a sintered metallic alloy having toughness capable of supporting stress at a point by distributing structure portions having different values of rigidity approximately uniformly without separation of layers different in brashiness. A method of manufacturing the sintered metallic alloy and a sintered alloy gear employing the sintered metallic alloy are also provided. Metallic materials are formed into a predetermined configuration. Then, the metallic materials is sintered in a sintering furnace (14) to make a sintered metallic alloy. Next, the sintered metallic alloy is cooled gradually to an ambient atmosphere of room temperature. Finally, the temperature of the cooled metallic alloy is raised and a toughness stabilizing process is performed in a low-temperature furnace (18) so that structures with high toughness are distributed approximately uniformly.

Abstract: The internal gear is a bottomed cylindrical component, which has the boss portion fitted over the outer circumferential surface of the shaft, the disk-shaped flange portion extending radially outwardly from the boss portion, and the cylindrical gear body having a tooth portion in its inner circumferential surface and connecting integrally to the outer circumferential part of the flange portion. The flange portion is virtually conical on its outer side surface and tapered from the outer diameter side toward the inner diameter side, i.e., from the gear body toward the boss portion. This construction is thicker at the boss portion side than at the gear body side. Further, the density of the flange portion is almost inversely proportional to the thickness and is lower at the boss portion side than at the gear body side. The cylindrical gear body has a density distribution such that the central part of the gear body is lower in density than the end portions in a tooth trace direction of the teeth portions.