Abstract: A belt type continuously variable transmission is provided with two pulley shafts arranged in parallel a predetermined distance apart from each other, a movable sheave provided on each pulley shaft and being able to slide in an axial direction thereof, a fixed sheave arranged on each pulley shaft so as to face the moveable sheave, the fixed sheave and the movable sheave that face each another on each pulley shaft together forming a groove therebetween, and a belt wound around the grooves. At least one of the movable sheaves and a motor serving as a driving source for the moving sheave are integrally provided.

Abstract: A vehicle transmission includes a crankshaft extending through a seal cover and into an oil-storing end portion of a driven shaft. The oil-storing end portion of the driven shaft defines a lubricating space filled with lubricating oil, and extends into the seal cover. A unidirectional clutch is disposed in the lubricating space and outwardly of the seal cover.

Abstract: The present invention provides an anti-rotation structure for a balance chamber snap ring of a belt type continuously variable transmission having a balance chamber that balances a centrifugal oil pressure generated in an oil pressure chamber formed on a movable sheave back surface. A projecting portion, which comes into contact with an end portion of the balance chamber snap ring when the balance chamber snap ring rotates independently within a ring groove about a secondary shaft, thereby restricting independent rotation of the balance chamber snap ring, is provided on a latch portion of a cover member. As a result, independent rotation of the balance chamber snap ring can be prevented, thereby preventing the cover member and the balance chamber snap ring from becoming worn.

Abstract: A sensing device integrated into a conical disk pair has a sensing piston, which is movable relative to the input shaft over a radially stepped guide surface formed on a shaft and a corresponding opposing stepped surface formed on the sensing piston. The steps form a damping chamber between the guide surface and the opposing surface, whose volume changes when the sensing piston moves relative to the shaft.

Abstract: A continuously-variable-transmission control device having high control response and stability, reduced processing load on a control device and V-belt wear recognition. The width of the V-belt is calculated on the basis of a position of the primary sheave, a length of the V-belt, a distance between the sheaves, an angle of the sheave, and a change gear ratio during idling, and the calculated belt width is stored. The control device performs a feed-forward control on the starter in which it corrects the target position of the primary sheave on the basis of the belt width, and then controls the sheave position so as to reach the corrected target position. When the calculated belt width becomes equal to or smaller than a predetermined threshold, the control device issues an alarm that alerts the driver to replace the V-belt.

Abstract: During Low return control, in which a speed ratio determined by a contact radius of a V-belt (4) with a non-rotating primary pulley (2) and a non-rotating secondary pulley (3) is shifted toward lowest speed ratio while the vehicle is stationary, an estimated speed ratio (ic) is calculated on the basis of a secondary pulley pressure (Psec). When a start request is issued to the vehicle while Low return control is underway, a primary pulley pressure (Ppri) and the secondary pulley pressure (Psec) are controlled on the basis of the estimated speed ratio (ic).

Abstract: A belt-driven conical-pulley transmission having a shaft on the input end and a shaft on the power output end. One of the shafts includes at least one axial bore extending in the longitudinal direction of the shaft, and a transverse bore extending from the axial bore to an outlet on the surface of the shaft. A conical disk pair is carried on the shaft and includes an axially fixed disk and an axially movable disk. The axially movable disk includes internal teeth that engage with external teeth on the shaft, and it overlies the transverse bore outlet over its entire axial travel distance. The transverse bore outlet is positioned in the region of the interengaging teeth.

Abstract: A power transmission device is installed in a vehicle and connected to a power generation source that is capable of outputting power for driving. The power transmission device includes a belt-type continuously variable transmission; a working fluid accumulation portion; a friction engagement element; a first pump; a pressure regulating valve; a friction engagement element pressure regulating valve; a second pump; and a switching valve.

Abstract: A pressure supply between a variator shaft and a pressure chamber (6) for the axial displacement of the mobile disc of a pair of conic pulleys of a continuously adjustable automatic transmission, which includes a longitudinal borehole (7) and radial boreholes (8, 9) in a variator shaft (1), as well as a radial borehole (10) in the locating disc. For each pressure chamber (6) there are at least two piercing radial boreholes made in the variator shaft, which are axially shifted from each other and rotated approximately 90° between themselves. The oil can run over the longitudinal borehole of the variator shaft and over the radial boreholes through the radial borehole in a locating disc of a pressure chamber (6), in such a way that the oil flow is always ensured regardless of the axial position or of the tangential location of the locating disc regarding the variator shaft.

Abstract: In a continuously variable transmission, a primary pulley includes a first fixed sheave coupled with an input rotation shaft, and a first movable sheave configured to move on the input rotation shaft in an axial direction of the primary pulley; and a secondary pulley includes a second fixed sheave, and a second movable sheave. At least one of the primary and secondary pulleys further includes an axially fixed wall configured to rotate together with the corresponding rotation shaft; and a movable cylinder configured to move together with the corresponding movable sheave, cooperating with the fixed wall to define a cylinder chamber of the corresponding pulley, and having a cylindrically-shaped opening axially outside of the cylinder chamber, the movable cylinder being laid out to permit the opening to axially overlap with at least a portion of a bearing which rotatably supports the corresponding rotation shaft.

Abstract: In a hydraulic control system for a transmission, line pressure Pl is adjusted in accordance with a second solenoid pressure Psls if the ratio of a first sheave pressure Pin with respect to a second solenoid pressure Psls is equal to or less than the gain ?. If not so, the line pressure Pl is adjusted in accordance with the first sheave pressure Pin. Consequently, the gain ? of the first sheave pressure Pin with respect to a first solenoid pressure Pslp at a first sheave pressure adjustment valve 16 and the gain ? of a second sheave pressure Pout with respect to the second solenoid pressure Psls at a second sheave pressure adjustment valve 17 can be individually set while the line pressure Pl can be suppressed to the substantially requisite minimum in the entire control region.

Abstract: A belt type continuously variable transmission in which a pulley shaft is supported by bearings provided at two positions that are apart from each other in an axial direction of the pulley shaft and a supply oil passage for supplying hydraulic fluid to a pulley hydraulic chamber includes a radial direction oil passage that is formed in the pulley shaft, the radial direction oil passage is formed on an outside of an area between the two positions. Also, one of the bearings is provided near the radial direction oil passage and on an outer surface side of a cylinder member whose inner surface side forms the pulley hydraulic chamber for a movable sheave that is fixed to the pulley shaft. With this structure, concentration of stress on the radial direction oil passage can be avoided, and therefore strength of the pulley shaft can be secured.

Abstract: A control valve switches between the (A) state where the first oil passage to which a hydraulic pressure obtained by decreasing a line pressure is supplied is in communication with the fifth oil passage for supplying the hydraulic pressure to a forward clutch or a reverse brake and the third oil passage to which a hydraulic pressure controlled by an SLP linear solenoid valve is supplied is in communication with the sixth oil passage for supplying the hydraulic pressure to a primary pulley, and the (B) state where the second oil passage to which a hydraulic pressure controlled by an SLT linear solenoid valve is supplied is in communication with the fifth oil passage and the fourth oil passage for supplying the hydraulic pressure to a secondary pulley is in communication with the sixth oil passage. The fourth oil passage has an orifice.

Abstract: A continuously variable transmission is provided with i) a primary pulley that is formed by a driving-side fixed sheave that is fixed to a drive shaft, a driving-side movable sheave, and a driving-side cylinder member, and has a driving-side cylinder, ii) a secondary pulley that is formed by a driven-side fixed sheave that is fixed to a driven shaft, a driven-side movable sheave, and a driven-side cylinder member, and has a driven-side cylinder, and iii) a drive belt. The drive shaft has a drive shaft internal fluid passage for supplying hydraulic fluid to the driving-side cylinder. A driving-side communicating fluid passage that communicates the drive shaft internal fluid passage with the driving-side cylinder is formed between the driving-side cylinder member and the driving-side movable sheave.

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: This invention is a speed ratio change control device for a belt type continuously variable transmission that a minimum generated pressure of the primary pressure is estimated on the basis of a displacement speed of the movable sheave of the primary pulley and an opening area of a drain side passage of the speed ratio change control valve (S4), an upper limit value of a shift speed is calculated on the basis of the minimum generated pressure (S6), and the target speed ratio is set on the basis of the upper limit value of the shift speed (S10).

Abstract: A hybrid clamping mechanism for a belt continuously variable transmission (CVT) is disclosed. A pulley having adjustable belt-engagement surfaces allow for a variable effective diameter of the belt when about the pulley. A clamping spring disposed to bias the belt-engagement surfaces closer together exert a clamping force on the belt. A first hydraulic drive is disposed to assist the clamping force of the clamping spring, and a second hydraulic drive is disposed to oppose the clamping force of the clamping spring. The total clamping force at the belt results from the clamping spring, the first hydraulic drive, the second hydraulic drive, or any combination comprising at least one of the foregoing.

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: The invention relates to a device for supplying a hydraulic medium to a rotatably mounted drive element in a transmission case, the hydraulic medium being routed to a channel in the drive element by way of at least one channel in a coaxially adjacent element which corresponds to the drive element. Structurally favorable and reliable supply with hydraulic medium is achieved in that the drive element is nonrotatably connected to the other element and that the contact connection is at least one unthreaded conduit which is inserted tightly into the two channels and which extends directly from the element to the drive element.

Abstract: Usually, the speed change control of the transmission is carried out in accordance with a real speed ratio “i” provided based on a primary pulley rotation speed “N1” and a secondary pulley rotation speed “N2”. While, when, at the time of stopping the vehicle, the real speed ratio fails to return to a value corresponding to the lowest speed position of the transmission, it is judged that there is a speed change failure. Upon this judgment, hydraulic pressures “p1” and “p2” for varying practical diameters of the primary and secondary pulleys are fixed to predetermined values “p1(old)” and “p2(old)” provided for such speed change failure.

Abstract: A power transmission system having an input member (6) and an output member (2) for transmitting power, and an oil pump (7) for discharging oil by a relative rotation between a first (8, 70) and a second rotary members (9, 87, 88) which is driven by the power transmitted between the input member (6) and the output member (2), characterized in that: the input member (6) and the first rotary member (8, 70) are connected with each other in a power transmittable manner, and the output member (2) and the second rotary member (9, 87, 88) are connected with each other in a power transmittable manner; and characterized by comprising: a transmission member (11, 13, 76, 77) for connecting the first and the second rotary members in a power transmittable manner; and a control valve (9, 87, 88) for controlling a power transmission state between the first and the second rotary members, by controlling a discharge condition of the oil pump (7).

Abstract: A control system of a power transmission mechanism, in which a transmission torque capacity between transmission members varies according to a pressure to be applied to the transmission members and in which the pressure to be applied to the transmission members is controlled on the basis of such a slip condition between the transmission members as accompanies the lowering of the pressure. The control system comprises: a pressure lowering device for lowering the pressure by a preset value; and a pressure setter for setting the pressure, in case the slip between the transmission members is not detected even by lowering the pressure by a preset value with the pressure lowering device, on the basis of the lowered minimum value of the pressure.

Abstract: A sensor is placed in proximity to a chain of a continuously variable transmission, and a pulse is output by detecting pins. Moreover, there is provided a control section that determines theoretical speed of the chain from numbers of input and output rotations of the continuously variable transmission; that determines actual speed of the chain from an output from the sensor; that determines slippage from the speeds; and that controls clamping force of the continuously variable transmission so as to make slippage close to a reference value.

Abstract: A continuously variable V-belt transmission basically has a driving pulley, a driven pulley and a V-belt wound around the pulleys. The frictional engagement between the pulleys and the V-belt is controlled by regulating pulley axial thrusts to the pulleys. The V-belt has a plurality of torque transmitting connected by an annular ring. A boundary-detection arrangement is provided to detect a boundary position between a first region, in which the elements are arranged without any gap therebetween, and a second region, in which the elements are arranged with a gap therebetween, along a portion of the driving pulley when torque is being transmitted. The detected boundary position is used to estimate the pulley axial thrust applied by the driving pulley against the V-belt, and to control the pulley axial thrust to a lower limit which ensures that the V-belt will not slip upon application of the maximum torque.

Abstract: When a speed of a vehicle is less than 8 km/h, an upshift determination condition is established, an idle switch signal is turned off, and a downshift is detected, an operating speed of the step motor is limited. Thereby, since the operating speed of the step motor is limited even when the vehicle is rapidly decelerated and re-accelerated before a pulley ratio is returned to a lowest value Lo, a shift speed of the downshift performed in the re-acceleration is lowered, and no slippage occurs in a V-belt between pulleys.

Abstract: When the vehicle is stationary, the gear ratio is shifted to a Low side by controlling the position of a shift actuator such that a shift control valve is controlled to a position in which a first oil pressure shifts toward a neutral position side by a predetermined amount from a maximum discharge side position and a controlling secondary pulley pressure control unit to increase a second oil pressure to a predetermined oil pressure.

Abstract: A continuously variable transmission in which a sliding member is prevented from inclining is provided. The continuously variable transmission has a first oil passage provided in a movable sheave, and a second oil passage provided in a primary shaft supporting the movable sheave and connected in series to the first oil passage. A working oil is discharged from a hydraulic chamber via the first and second oil passages. The working oil is more difficult to discharge from the second oil passage than the first oil passage.

Abstract: A hydraulic actuator for a belt type continuously variable transmission, with which a smooth operation is secured and both superior productivity and reduced manufacturing costs can be expected, includes a first cylinder provided on a movable sheave, a drum having a first drum portion that covers the first cylinder and a second drum portion that is fitted to a boss portion of the movable sheave and formed with a plurality of projections, a first plunger having a cylindrical portion that is fitted to the first cylinder and the second drum portion to form a first hydraulic chamber, and a second plunger fitted to the cylindrical portion and the first cylinder to form a second hydraulic chamber. An oil passage connecting the first hydraulic chamber and the second hydraulic chamber is formed by a gap between the second drum portion and cylindrical portion, which are fitted together.

Abstract: In a vehicular belt-driven continuously variable transmission, belt squeezing force is inhibited from becoming excessive and a safety factor, with respect to belt slip, of belt squeezing force applied to a transmission belt (48) is reduced to a value that is less than or equal to 1.5 by reducing a pressure receiving area (SOUT) of an output side hydraulic cylinder (46c). As a result, a centrifugal hydraulic pressure canceller chamber on a secondary pulley side (46) can be eliminated thus simplifying the structure of the vehicular belt-driven continuously variable transmission, while belt squeezing force can be appropriately controlled.

Abstract: A vehicle transmission includes a crankshaft box unit, a clutch unit, and a transmission box unit. The crankshaft box unit includes a crankshaft box, a crankshaft extending through the clutch unit and into the transmission box unit, a driven shaft disposed in the transmission box unit and having an end sleeved on a connecting end of the crankshaft, and a bearing disposed between the crankshaft and the driven shaft. The clutch unit includes a seal cover disposed in proximity to the crankshaft box, and a wet clutch disposed between the seal cover and the crankshaft box. The crankshaft extends through the seal cover. The connecting end of the crankshaft is disposed in a transmission box of the transmission box unit.

Abstract: A continuously variable transmission having an input cone pulley pair and an output cone pulley pair linked by and an encircling mechanism. One pulley of each pair is axially fixed and one pulley is axially displaceable to control the transmission ratio of the transmission. A recoil spring engages between the input moveable pulley and an axially fixed contact surface only when the transmission is in the low transmission ratio range for exerting a force to displace the input moveable cone pulley to a high transmission ratio to avoid damage to the transmission or starting clutch during towing.

Abstract: In a V-belt continuously variable transmission (CVT), a sheave drive mechanism includes a movable tube coupled to a movable sheave half of a primary sheave so as to be rotatable with respect thereto and axially movable together therewith, a fixed tube disposed internally of and coaxially with the movable tube, and a ball screw mechanism provided between the fixed tube and the movable tube. The sheave drive mechanism further includes an outer peripheral wall arranged to cover the area from a fixed end of the fixed tube to the outer periphery of the movable tube, an oil seal provided between the movable tube and the outer peripheral wall to seal an internal space for enclosing the working surface of the ball screw mechanism, and a communication path for communication between the internal space and the outside of the outer peripheral wall. The V-belt (CVT) has a smooth feed operation of the ball screw mechanism in the sheave drive mechanism and has a high durability attained by waterproofing.

Abstract: In a line pressure control apparatus of a belt-drive CVT, a shift is achieved by varying V- groove widths of primary and secondary pulleys by a differential pressure between primary and secondary pulley pressures, originating from line pressure. The differential pressure is created by bringing a shift actuator, such as a step motor, into a control position corresponding to a target transmission ratio. The target transmission ratio is calculated based on a theoretical transmission ratio based on engine-and-vehicle operating conditions, taking account of a hardware response delay and a disturbance. The target transmission ratio is converted into a reference-model operative position, corresponding to a reference-model number-of-steps of the shift actuator. An actual transmission ratio is converted into an actual-transmission-ratio related operative position.

Abstract: A flow control valve is provided in a primary pulley that is a rotor, and includes a first port; a second port; a working fluid channel formed between the first port and the second port and through which working oil passes; a check valve that is formed in the working fluid channel and is opened toward a first-port-side channel from a second-port-side channel of the working fluid channel; and a valve-opening control section (a guide member, a spool, a cylinder, and a drive pressure chamber) that is arranged at the check valve at the side of the second port, that forcibly opens the check valve when discharging the working fluid from the first port to the second port, and increases a channel resistance of the second-port-side channel as an opening amount of the check valve is small. The flow control valve can prevent over-discharge of the working fluid at the beginning of opening the valve.

Abstract: A conical disk pair for a belt-driven conical-pulley transmission includes a fixed disk, and a movable disk that is axially movable and rotationally fixed to an input shaft. A torque sensor is associated with the movable disk on a side opposite from the axially fixed disk and includes a sensing piston having axially-directed arms that are circumferentially spaced on a side of the sensing piston that faces away from the movable disk. The arms have outer axially—extending teeth that mesh with inner axial teeth of an input wheel. An inner support ring contacts the arms on an inner side radially opposite the outer teeth of the arms and forces the outer teeth of the arms into meshing engagement with circumferentially-positioned axial teeth of the input wheel.

Abstract: In one embodiment, an oil pressure control apparatus includes a belt-driven continuously variable transmission, a lockup clutch provided in a torque converter, a primary regulator valve that regulates a line oil pressure that becomes a source pressure of oil pressure of various parts, and a clamping oil pressure control valve that supplies a clamping oil pressure to a driven-side pulley of the belt-driven continuously variable transmission. Control of the primary regulator valve is performed with a control oil pressure of a linear solenoid valve that controls the clamping oil pressure control valve, and a control oil pressure of a linear solenoid valve that controls engagement/release of the lockup clutch.

Abstract: A belt type continuously variable transmission that includes a primary pulley; a secondary pulley; a belt where the primary pulley and the secondary pulley are bound; a positioning hydraulic chamber that presses a primary movable sheave to a primary fixed sheave; a supply-side valve that permits working oil to be supplied from the outside to the positioning hydraulic chamber; and a discharge-side control valve that controls permission or prohibition of discharge of the working oil from the positioning hydraulic chamber to the outside. The discharge-side control valve prohibits discharge of the working oil from the positioning hydraulic chamber to the outside when a position of the primary movable sheave is kept constant in the axial direction with respect to the primary fixed sheave.

Abstract: A transmission 20 includes an input shaft 12, an output shaft 13, a primary sheave 23 that rotates together with the input shaft 12, a secondary sheave 24 that rotates together with the output shaft 13, and a belt 25 wound around both the primary sheave 23 and the secondary sheave 24. The transmission 20 includes a motor 22 that shifts a transmission ratio by driving a movable sheave 23a of the primary sheave 23. A control device (ECU 5) of the transmission 20 includes a secondary sheave rotation speed sensor 28 that detects rotation of the belt 25, and a control portion 55 of the ECU 5 performs a sheave position control (normal control of the transmission ratio) after rotation of the belt 25 is detected after starting.

Abstract: A pressure relief valve for a hydraulic system for controlling a belt-driven conical-pulley transmission. The valve includes an orifice having an opening to admit a stream of a hydraulic medium, and a valve cone to block the opening in the orifice. A spring is carried by the valve cone to apply a restoring force to press the valve cone against the orifice in sealing contact with the opening. A hydraulic plate having a valve bore is provided to receive and guide the valve cone and the spring. A lateral force support is carried by the valve cone to align the axis of the valve cone relative to the axis of the orifice opening.

Abstract: Two input-shaft-side fixed sheaves of respective first and second pulley-type continuously variable transmission mechanisms are integrally connected and secured to each other while their back sides abut against each other. One of output-shaft-side movable sheaves and the other of output-shaft-side fixed sheaves are provided between one of the output-shaft-side fixed sheaves and the other of the output-shaft-side movable sheaves while their back sides abut against each other, so as to be rotatable relative to each other and so as to be movable together on a sun-gear input shaft. The one of the output-shaft-side movable sheaves is formed consecutively with an input shaft of a planetary carrier of a planetary gear mechanism. The other of the output-shaft-side fixed pulleys is formed consecutively with an input shaft of a sun gear of the planetary gear mechanism.

Abstract: A oil supply system is provided for the CVT of an automobile, and includes: a variable-transmission hydraulic controller, which employs hydraulic oil to adjust the actual gear ratio until the actual and the target gear ratios match; and a CVT controller, which transmits operation instructions to the variable-transmission hydraulic controller. The variable-transmission hydraulic controller includes a motor-driven oil pump, driven by an electric motor, for supplying hydraulic oil to the CVT. Based on an operation instruction transmitted by the CVT controller, the electric motor is rotated either forward to increase the pressure of hydraulic oil to be supplied to the CVT, or rearward to reduce the pressure, so that the pressure of the hydraulic oil can be adjusted to obtain a required pressure value that is consonant with the operating state of the automobile.

Abstract: In hydraulic pressure control apparatus and method for a continuously variable transmission, a line pressure of the continuously variable transmission is developed with a working oil supplied from an oil pump as an original pressure, and a command pressure is set to develop a line pressure target value of the target value in such a manner that the command pressure is maintained at a predetermined small value for a constant time and, thereafter, the value of the command pressure is raised up to the target value when a shift range of the continuously variable transmission is switched from a neutral range to a running range, the command pressure being raised at a rate lower than a step input to suppress an overshoot developed in the actual line pressure.

Abstract: A belt-driven conical-pulley transmission contained in the power train of a motor vehicle and having two conical disk pairs encircled by an endless torque-transmitting element. A hydraulic system is provided for pressing the conical surfaces of the conical disks against the endless torque-transmitting means and for opposite adjustment of the spacing between the conical disks for an adjustment of the transmission ratio. The hydraulic system includes a pump driven by an internal combustion engine that propels the vehicle, and the system includes an auxiliary oil source with which a predetermined minimum pressure is maintained in the hydraulic system when the internal combustion engine is shut off.

Abstract: A hydraulic system for controlling a belt-driven conical-pulley transmission of a motor vehicle, wherein the transmission has a variably adjustable transmission ratio. The hydraulic system includes a first valve arrangement to control a contact pressure in the belt-driven conical-pulley transmission, a second valve arrangement to control the transmission ratio of the belt-driven conical-pulley transmission, and a hydraulic energy source to supply the hydraulic system with hydraulic energy. In order to provide an improved hydraulic system, the system includes a third valve arrangement for controlling a forward clutch and a reverse clutch.

Abstract: A control device for controlling a continuously variable transmission (5) is disclosed. The control device has an oil pressure control unit (100) which supplies an oil pressure to a primary pulley (10) and secondary pulley (11) based on a command signal indicative of a target speed-reduction ratio, a sensor (26) which detects a rotation speed (Np1) of the primary pulley (26), and a controller (20) which transmits the command signal indicative of the target speed-reduction ratio to the oil pressure control unit (100).

Abstract: When a vehicle decelerates rapidly, a lower limit secondary pulley pressure (Plmt) is calculated on the basis of a primary pulley rotation speed (Npri) detected by a primary pulley rotation sensor. When a deceleration speed (Gdata) is greater than a predetermined deceleration speed (G1) and a secondary pulley pressure (Psec) detected by a secondary pulley pressure sensor is lower than the lower limit secondary pulley pressure (Plmt), it is determined that slippage is about to occur in a V-belt 4 on a primary pulley side in particular, and therefore speed ratio fixing control is performed.

Abstract: A shift control apparatus of a belt type continuously variable transmission is comprised of a controller which is arranged to set a first hydraulic pressure controlled variable based on a first target transmission ratio determined based on a vehicle traveling condition, to set a second hydraulic controlled variable based on a second target transmission ratio determined based on a predetermined transfer characteristic, to steplessly control the transmission ratio by controlling hydraulic pressures of primary and secondary pulleys hydraulic based on the first and second hydraulic pressure controlled variables, to detect at least one of the hydraulic pressures of the primary and secondary pulleys, and to correct the second target transmission ratio based on the detected hydraulic pressure.

Abstract: A procedure for the control of ratio-change occurrences of an automatic transmission in a motor vehicle, which vehicle possesses a hydraulic system with at least two hydraulic pressure branches (3, 9) with different hydraulic pressures, wherein in a first hydraulic pressure branch (3) controllable pressure reducing valves (4, 5) can be found, by which the hydraulic users (S1, S2) can be supplied with an activation pressure, wherein in the first hydraulic pressure branch (3), a pressure regulation valve (6) is placed, the exit port of which is connected to a line of the second hydraulic pressure branch (9), and wherein by the activation of the pressure regulation valve (6) the pressure in the first hydraulic circuit (3) is adjustable, and whereby in the first hydraulic pressure branch (3) a hydraulic pressure is provided, which represents the highest, necessary operational pressure of the hydraulic users (S1, S2, 11) plus an offset pressure.

Abstract: A belt clamping pressure setting device includes: a belt clamping pressure setting unit that sets a belt clamping pressure of a continuously variable transmission that includes an input-side pulley, an output-side pulley, and a belt running between the input-side pulley and the out-side pulley; an input revolution detection sensor that detects a number of input revolutions of the input-side pulley; an output revolution detection sensor that detects a number of output revolutions of the output-side pulley; an input torque detection unit that detects an input torque to the input-side pulley; a reference clamping pressure computing unit that computes a reference clamping pressure, based on the number of input revolutions detected by the input revolution detection sensor, the number of output revolutions detected by the output revolution detection sensor, and the input torque detected by the input torque detection unit; and a belt clamping pressure computing unit that computes the belt clamping pressure to be set

Abstract: A gear change control system of a belt-type continuously variable transmission includes: a movable pulley piston chamber for causing a thrust force to a movable pulley varying a groove width of primary pulley and secondary pulley. The movable pulley piston chamber has double-piston constitution including: a primary clamp chamber and a secondary clamp chamber, for causing a clamp force of clamping the belt, and a cylinder chamber including a primary pulley cylinder chamber and a secondary pulley cylinder chamber, for causing a differential thrust force at a gear change. A clamp chamber oil pressure setting section sets up a clamp chamber oil pressure by the following calculation: dividing the one of the primary thrust force and the secondary thrust force by addition of: applied pressure area of one of the primary clamp chamber and the secondary clamp chamber, and applied pressure area of the cylinder chamber on a selected side.