Abstract: A belt for a continuously variable transmission including a plurality of metal ring assemblies and a plurality of metal elements is provided, wherein a main surface of each of the plurality of metal elements is formed at its three portions with contact faces for transmitting a pushing force in the fore-and-aft direction, and the radial position of the centroid of the contact faces is set between a center line in a thickness direction of the metal ring assembly fitted into the ring slot of the metal element and a line along a radial outer edge of the ring slot. With this structure, a compressed-side chord of the metal belt can assume a straight shape or a slightly outwardly warped shape, and it is possible to elongate the life of the metal ring assemblies to reduce noise and vibration, and to enhance the power transmitting efficiency.

Abstract: A power transmission system for a hybrid vehicle includes a motor/generator and a torque converter. The motor/generator and the torque converter are disposed in series between a crankshaft of an engine and a main shaft of a transmission. A side plate of the torque converter and a rotor disc of the motor/generator are connected via a drive plate having heat shielding properties and heat releasing properties.

Abstract: In a belt for a continuously variable transmission, a first clearance CLNH is defined between a projection and a recess formed on front and rear surfaces of a metal element, and a second clearance CLy is defined between an upper surface of a metal ring assembly and a lower ear surface of the metal element. The setting of a relation, CLY>CLNH ensures that when the metal element has been pitched, the projection and the recess can be first brought into contact with each other, thereby preventing a reduction in durability which may otherwise occur by the lower ear surface coming into contact with the upper surface of the metal ring assembly. If the thickness of the metal ring assembly is represented by TL, and the vertical opening of the ring slot is represented by D, when the value of D/TL exceeds {fraction (11/8)}, the power transmitting efficiency is reduced. Therefore, the reduction in power transmitting efficiency can be prevented by setting D/TL at a smaller value than {fraction (11/8)}.

Abstract: A system for controlling an automatic transmission of a vehicle which determines a downgrade or upgrade parameter based on the vehicle acceleration and selects one from among a plurality of shift programs based on the determined grade parameter to determine a gear ratio based on the selected shift program. The system includes a navigation system which determines the instantaneous vehicle position and outputs road information including upgrade/downgrade condition of road including the determined instantaneous vehicle position. In the system, the grade parameter is corrected based on the navigation information and the grade parameter such that the one from among a plurality of shift programs is selected based on the corrected grade parameter, thereby enhancing drivability during downgrade running, without being affected even if the navigation information is temporarily invalid.

Abstract: A transmission comprises an engine, which is controllable to stop under a predetermined condition, and a speed change mechanism TM, which transmits the output rotation of the engine at different speed ratios. The speed change mechanism TM has a plurality of transmission paths (the LOW ratio, the SECOND speed ratio, etc.) disposed in parallel, a plurality of ratio-setting clutches (the LOW clutch 11, the SECOND speed clutch 12, etc.), each clutch for selecting a predetermined transmission path, and a speed change control system for selectively supplying a hydraulic pressure to any of the ratio-setting clutches to bring it into engagement. Engagement-initiation time is calculated for each ratio-setting clutch, so that the ratio-setting clutch requiring a minimum engagement-initiation time is selected as the clutch for the start-up speed ratio. When the engine is restarted from stopped state, this clutch for the start-up speed ratio is supplied with oil.

Abstract: In a metal belt-type continuously variable transmission, the radius of winding a metal belt around a drive pulley is increased to change the shift ratio i by applying a larger first axial thrust to the drive pulley and a smaller second axial thrust to a driven pulley during upshifting. In a region B where the relationship between a first axial thrust and the gear shifting speed dR/ds defined as a value obtained by differentiating the radius R of winding of the metal belt around the drive pulley by an amount s of tangential movement of the metal belt is maintained substantially linearly, the first axial thrust is subjected to a feedforward control based on a target gear shifting speed dR/ds. In regions A and C where the relationship between the first axial thrust and the gear shifting speed dR/ds is not maintained substantially linearly, the first axial thrust is subjected to a feedback control, so that the gear shifting speed dR/ds is equal to the target gear shifting speed dR/ds.

Abstract: A shift control system is arranged such that a shift lever 201 is movable to a “P” position, an “R” position, an “N” position, a “D5” position and a “D4” position along a first shift guide path 211, it is movable also from the “D4” position to a “3/M” position along a connection shift guide path 212, and it is movable also along a second shift guide path 213, from the “3/M” position into a direction different from that of the connection shift guide path 212. When the shift lever is shifted to the “D5” position, the transmission is set into an automatic shift control with forward drive speed ratios up to the FIFTH speed ratio. When the shift lever is shifted to the “D4” position, the transmission is set into an automatic shift control with forward drive speed ratios up to the FOURTH speed ratio.

Abstract: Clearance Cs during a no-load stop and allowable value Cto of total clearance Ct obtained as a sum of clearance Ch occurring due to Hertzian stress are stipulated to a value less than height h of male coupling 28 along with an allowable value &sgr;hmo of the maximum Hertzian stress acting on rocking edge 26 being stipulated to a value less than an upper limit value &sgr;ho of the Hertzian stress that satisfies the opposing pitching lifespan. The radius of curvature R of the rocking edge is set within a range that satisfies R1≦R≦R2 for the radius of curvature R1 determined in correspondence with the allowable value &sgr;hmo of the maximum Hertzian stress and the radius of curvature R2 determined in correspondence with the allowable value Cto of the clearance between the total elements.

Abstract: A shift control system for an automatic transmission comprises a shift lever 201, which is shifted among a “P” position, an “N” position and an “S” position. A first shift guide path 211 is provided to guide the shift lever from the “P” position through the “N” position to the “S” position, and a second shift guide path 212 is provided to guide the shift lever which has been positioned at the “S” position in a direction different from that of the first shift guide path. Along this second shift guide path, the shift lever is shifted to select and set a plurality of ranges necessary for driving a vehicle, including a forward drive range, a neutral range and a reverse drive range.

Abstract: A constant-speed running controller which sets a target throttle opening of a throttle valve such that the speed of a vehicle is at a target vehicle speed, detects an amount of accelerator pedal operation as an accelerating pedal opening, adds the set target throttle opening and the detected accelerating pedal opening to generate an opening signal as the addition result, and drives the throttle valve and controls a transmission stage of an automatic transmission in accordance with the opening signal.

Abstract: In a section near a rocking edge of each of metal elements used in a metal belt for a continuously variable transmission, a pair of protrusions are formed at laterally opposite ends of a front main surface opposed to a preceding metal element, and flat surface portions are formed on a rear main surface opposed to a succeeding metal element. The metal elements can be wound in a correct attitude around a pulley without being yawed by the contact of the protrusions and the flat surface portions with each other, whereby they can be prevented from being damaged. Further the metal elements contacting with each other in a chord section of the metal belt can slide laterally. Thus, a misalignment between a drive pulley and a driven pulley can be absorbed.

Abstract: An automatic gear change controller, having a constant speed travel mode, which can transmit torque to wheels of a vehicle according to changes in the travel load of the vehicle even though a gear shift mode is changed to the manual gear shift mode. When the gear shift mode is set in the manual gear shift mode and the travel mode is set in a constant speed travel mode, a constant speed travel controller generates a downshift command signal. In this case, when the accelerator pedal is depressed beyond a predetermined amount, the gear shift stage of the automatic transmission is downshifted.

Abstract: A control system for an automatic transmission of a vehicle is disclosed. The automatic transmission operates in a manual operating mode in which a shift position of the automatic transmission can be changed according to a shift instruction issued by a driver of the vehicle, or in an automatic operating mode in which the shift position is automatically selected. In the control system, a slow running intention of the driver is detected. A first shift position is set to a starting shift position at the time of starting the vehicle when the slow running intention of the driver is not detected in the manual operating mode. A second shift position which is lower in transmission gear ratio than the first shift position is set to the starting shift position when the slow running intention of the driver is detected in the manual operating mode.

Abstract: A belt for continuously variable transmission, wherein the relationship between the thickness of the metal ring assembly and the groove width of the ring slot is established so that a limit rolling angle &agr; defined as a rolling angle of the metal elements provided when a radially outer peripheral surface of the metal ring assembly contacts a radially outer edge of the ring slot in the metal element is in a range of 0.7°<&agr;<2.5°. The upper limit value 2.5° of the angle &agr; is set as a rolling angle at which the driving force transmitting efficiency is a predetermined value or more, and the lower limit value 0.7° of the angle &agr; is set as a rolling angle generated following the deformation of a V-face due to an axial thrust on a drive or driven pulley.

Abstract: An automatic transmission comprises a plurality of clutches 11˜15, which are provided to select power transmission paths, respectively, in a parallel shaft speed change mechanism TM and a plurality of shift valves 60˜68, which are used for controlling the supply and drain of hydraulic oil to and from these clutches. For this automatic transmission, a control system comprises a plurality of solenoid valves 81˜85, which are used for controlling the supply and drain of a line pressure so as to control the actuation of these shift valves. This system, when the shift lever is manipulated to set the neutral range, sets the transmission into either a first neutral mode or a second neutral mode depending upon the speed of the vehicle, the first neutral mode being set when the vehicle is driving at a speed equal to or more than a critical speed, and the second neutral mode being set when the vehicle speed is less than the critical speed.

Abstract: An automatic transmission comprises a plurality of clutches 11˜15, which are provided to select power transmission paths, respectively, in a parallel shaft speed change mechanism TM and a plurality of shift valves 60˜68, which are used for controlling the supply and drain of hydraulic pressure to and from these clutches. For this automatic transmission, a control system comprises a forward/reverse selection hydraulic servomechanism 70 and a plurality of solenoid valves 81˜85, which are used for controlling the supply and drain of a line pressure so as to control the actuation of these shift valves and the forward/reverse selection hydraulic servomechanism.

Abstract: A belt for a continuously variable transmission includes a metal element 32 having a rocking edge 40 between a main surface 38 and a slope 41 on the front side of the metal element in the advancing direction and a ring slot 35, into which a metal ring assembly 31 is fitted, between an element body 34 and an ear portion 36. The position of the center of gravity G of the metal element 32 is regulated to the outside of the rocking edge 40 and to the inside of a radially outer end 351 of the ring slot 35.

Abstract: Clearance Cs during a no-load stop and allowable value Cto of total clearance Ct obtained as a sum of clearance Ch occurring due to Hertzian stress are stipulated to a value less than height h of male coupling 28 along with an allowable value &sgr;hmo of the maximum Hertzian stress acting on rocking edge 26 being stipulated to a value less than an upper limit value &sgr;ho of the Hertzian stress that satisfies the opposing pitching lifespan. The radius of curvature R of the rocking edge is set within a range that satisfies R1≦R≦R2 for the radius of curvature R1 determined in correspondence with the allowable value &sgr;hmo of the maximum Hertzian stress and the radius of curvature R2 determined in correspondence with the allowable value Cto of the clearance between the total elements.

Abstract: A system for controlling an automatic transmission of a vehicle which determines a downgrade or upgrade parameter based on the vehicle acceleration and selects one from among a plurality of shift programs based on the determined grade parameter to determine a gear ratio based on the selected shift program. The system includes a navigation system which determines the instantaneous vehicle position and outputs road information including upgrade/downgrade condition of road including the determined instantaneous vehicle position. In the system, the grade parameter is corrected based on the navigation information and the grade parameter such that the one from among a plurality of shift programs is selected based on the corrected grade parameter, thereby enhancing drivability during downgrade running, without being affected even if the navigation information is temporarily invalid.

Abstract: A shift control system for an automatic transmission comprises a shift lever 201, which is shifted among a “P” position, an “N” position and an “S” position. A first shift guide path 211 is provided to guide the shift lever from the “P” position through the “N” position to the “S” position, and a second shift guide path 212 is provided to guide the shift lever which has been positioned at the “S” position in a direction different from that of the first shift guide path. Along this second shift guide path, the shift lever is shifted to select and set a plurality of ranges necessary for driving a vehicle, including a forward drive range, a neutral range and a reverse drive range.