Abstract: Provided is control device and method for a belt type continuously variable transmission which can reduce drive energy consumption by a decrease in belt friction when the estimated accuracy of belt slip condition is high and which can prevent the belt from greatly slipping during belt slip control when the estimated accuracy of belt slip condition is low. The device includes a primary pulley (42), a secondary pulley (43), and a belt (44) and controls gear ratio based on the running radius of the belt (44) on the pulley by controlling the primary oil pressure and the secondary oil pressure.

Abstract: A control device and a control method for a belt type-continuously variable transmission capable of preventing a belt slip from occurring by restricting that an input torque to the belt type-continuously variable transmission is excessive relative to a belt clamp force when returning from a belt slip control to a normal control are provided are provided. The control device includes a primary pulley (42), a secondary pulley (43), and a belt (44) and is configured to control a variable speed ratio determined by a running radius ratio of the belt (44) on the pulleys by controlling a primary hydraulic pressure and a secondary hydraulic pressure.

Abstract: Provided are control device and method for a belt type continuously variable transmission which can improve control stability of secondary hydraulic pressure with the estimated accuracy of a belt slip condition during belt slip control ensured. The device has a primary pulley (42), a secondary pulley (43), and a belt (44), and a secondary hydraulic pressure controller (92) to determine command secondary hydraulic pressure by feedback control based on the deviation (?) between target secondary hydraulic pressure and actual hydraulic pressure, and control the secondary hydraulic pressure to the secondary pulley (43). A belt type continuously variable transmission mechanism (4) includes a belt slip control means (FIG.

Abstract: Provided is control device and method for a belt type continuously variable transmission which can reduce drive energy consumption by a decrease in belt friction when the estimated accuracy of belt slip condition is high and which can prevent the belt from greatly slipping during belt slip control when the estimated accuracy of belt slip condition is low. The device includes a primary pulley (42), a secondary pulley (43), and a belt (44) and controls gear ratio based on the running radius of the belt (44) on the pulley by controlling the primary oil pressure and the secondary oil pressure.

Abstract: When a speed ratio (ip) at a stopping time of the vehicle cannot be stored, an operating position of a step motor (27) is initialized to a home position such that a primary pulley pressure (Ppri) is completely drained, a secondary pulley pressure (Psec) is increased to a predetermined pressure (P1), and a pulley ratio (the speed ratio (ip)) between a non-rotating primary pulley (2) and a non-rotating secondary pulley (3) is set at a lowest speed ratio. As a result, the primary pulley pressure (Ppri) is supplied reliably, and the startability of the vehicle improves.

Abstract: A control apparatus for an automatic transmission includes a control section having a target secondary pressure setting section configured to set a target secondary pressure within a strength limit of the belt, and an operation switching section configured to switch a shift operation from a normal speed to a high speed higher than the normal speed when a predetermined condition is satisfied. The control section is configured to control the secondary pressure regulating valve by a feedback control based on the target secondary pressure and the actual secondary pressure sensed by the hydraulic pressure sensor. The target secondary pressure setting section is configured to modify the target secondary pressure by adding a predetermined quantity when a correction initiation condition is satisfied, the condition initiation including a first condition that the shift operation is performed at a high speed by switching of the operation switching section.

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 speed ratio change control device for a belt type continuously variable transmission calculates a maximum thrust that can be generated by the primary pulley on the basis of an upper limit value of the line pressure, calculates an upper limit value of a shift speed on the basis of the maximum thrust, and sets the target speed ratio on the basis of the upper limit value of the shift speed.

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 control apparatus for an automatic transmission includes a control section having a normal control section configured to actuate the step motor at a first speed by using a feedback control including an integral control in accordance with the target pulley ratio and the actual pulley ratio, a high speed control section configured to actuate the step motor at a second speed higher than the first speed by an open loop control based on the target pulley ratio, a judgment section configured to judge whether there is a high speed operation request, and a switch section configured to select the normal control performed by the normal control section at a normal condition, and to switch to the high speed control when a switch start condition is satisfied, the switch start condition including a first condition that the judgment section judges there is the high speed operation request.

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: 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: 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: 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: This invention is a speed ratio change control device for a belt type continuously variable transmission that a maximum thrust that can be generated by the primary pulley is calculated on the basis of an upper limit value of the line pressure (S3), an upper limit value of a shift speed is calculated on the basis of the maximum thrust (S5), and the target speed ratio is set on the basis of the upper limit value of the shift speed (S9).

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: 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: When a speed ratio (ip) at a stopping time of the vehicle cannot be stored, an operating position of a step motor (27) is initialized to a home position such that a primary pulley pressure (Ppri) is completely drained, a secondary pulley pressure (Psec) is increased to a predetermined pressure (P1), and a pulley ratio (the speed ratio (ip)) between a non-rotating primary pulley (2) and a non-rotating secondary pulley (3) is set at a lowest speed ratio. As a result, the primary pulley pressure (Ppri) is supplied reliably, and the startability of the vehicle improves.

Abstract: A hydraulic control apparatus for an automatic transmission with a line pressure regulator valve operative to regulate an oil pressure produced by an oil pump and set a line pressure, the hydraulic control apparatus including a control unit outputting a first command for controlling the line pressure regulator valve to set the line pressure to a minimum value immediately after engine start, and a second command for controlling the line pressure regulator valve to set the line pressure to a target value in accordance with increase in engine speed. The control unit is programmed to set the target value of the line pressure to a value smaller than a maximum value of the line pressure and/or reduce a target speed of engine speed, upon start of the engine in a low temperature condition.

Abstract: A control apparatus for an automatic transmission includes a control section having a target secondary pressure setting section configured to set a target secondary pressure within a strength limit of the belt, and an operation switching section configured to switch a shift operation from a normal speed to a high speed higher than the normal speed when a predetermined condition is satisfied. The control section is configured to control the secondary pressure regulating valve by a feedback control based on the target secondary pressure and the actual secondary pressure sensed by the hydraulic pressure sensor. The target secondary pressure setting section is configured to modify the target secondary pressure by adding a predetermined quantity when a correction initiation condition is satisfied, the condition initiation including a first condition that the shift operation is performed at a high speed by switching of the operation switching section.