JP2010216571A - Control device of belt type continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a belt type continuously variable transmission capable of suppressing properly a belt slip when a vehicle is going to start up a slope while worsening of the belt durability is suppressed. <P>SOLUTION: In case the G sensor value a when a vehicle is at a standstill is smaller than the threshold A (Yes in S1), the ECU of the control device determines that the road surface is an ascending slope involving the risk of slipping-down and starts increasing the belt pinching pressure (S1), and in case the G sensor value b when a wheel rotation is sensed, is smaller than the G sensor value a at a standstill (Yes in S3), a reverse rotation Flag is turned on (S5), while the reverse rotation Flag is turned off (S6) in case the G sensor value c when the reverse rotation Flag is on and the vehicle speed V becomes zero, is larger than the G sensor value a at a standstill (Yes at S5). In case the vehicle speed V is not less than the threshold B (Yes at S7), the increase of the belt pinching pressure is stopped (S9). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to control of a belt type continuously variable transmission, and more particularly to control of belt clamping pressure.

  An automatic transmission mounted on a vehicle includes a transmission mechanism that is connected to an engine via a torque converter or the like and has a plurality of power transmission paths. An example of such a transmission mechanism is a belt-type continuously variable transmission (CVT). In this belt type continuously variable transmission, a belt is wound around a driving pulley (input shaft pulley, primary pulley) and a driven pulley (output shaft pulley, secondary pulley) each having a V-groove pulley groove. By increasing the groove width of the pulley and narrowing the groove width of the other pulley at the same time, the belt wrapping radius (effective diameter) for each pulley is continuously changed to set the transmission ratio steplessly. It is configured.

  When a vehicle equipped with such a belt-type continuously variable transmission is stopped on an uphill road, the vehicle is driven in the forward direction (uphill road start) due to the influence of the backward component of gravity acceleration. In some cases, the vehicle moves backward (hereinafter, this phenomenon is also referred to as “sliding down”) against the intention of the person.

  For example, Japanese Patent Application Laid-Open No. 2001-208183 discloses a technique for suppressing belt slip due to insufficient line pressure at the time of slipping in a belt-type continuously variable transmission connected to an engine via a torque converter. The line pressure control device disclosed in this publication sets the target line pressure using the detected torque ratio of the torque converter when the vehicle speed is higher than the low vehicle speed range, and the vehicle speed is in the low vehicle speed range. Sets the target line pressure using a predetermined fixed torque ratio instead of the detected torque converter torque ratio. Therefore, if a slippage occurs, the vehicle speed itself is in the low vehicle speed range, and the target line pressure is set using a fixed torque ratio. It is possible to avoid a small calculation. Therefore, a necessary amount of the target line pressure of the continuously variable transmission can be secured, and belt slip due to insufficient line pressure can be suppressed.

JP 2001-208183 A JP-A-9-144862 JP 7-317863 A Japanese Patent Laid-Open No. 1-098748 JP 2000-9157 A

  By the way, when a downhill occurs when starting an uphill road, the rotation in the backward direction of the drive wheel is transmitted to the driven pulley, unlike the normal driving state. For this reason, although the forward torque is input from the belt to the driven pulley, the driven pulley rotates in the reverse direction (hereinafter also referred to as “reverse drive state”).

  In this reverse drive state, the torque capacity (transmittable torque) of the belt-type continuously variable transmission mechanism decreases due to factors such as the occurrence of some gaps between the belt elements in contact with the driven pulley, and belt slippage occurs. There are concerns about the occurrence.

  Therefore, it is necessary to increase the belt clamping pressure in order to suppress the belt slipping at the time of sliding down. However, if the belt clamping pressure is increased unnecessarily, the efficiency (deterioration of fuel consumption) and belt durability will be reduced. It leads to deterioration. For this reason, it is desirable to appropriately determine the sliding state, but it is difficult to appropriately determine the sliding state in a vehicle that does not include a sensor that can directly detect the rotational direction of the wheels.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to appropriately prevent belt slip at the start of an uphill road while suppressing deterioration in durability of the belt of the belt-type continuously variable transmission. It is providing the control apparatus which can be suppressed.

  The control device according to the present invention is a control device for a belt-type continuously variable transmission mounted on a vehicle. The vehicle detects acceleration in the front-rear direction of the vehicle, and detects an absolute value of the rotation speed of an acceleration sensor that outputs a higher value as the acceleration in the forward direction increases, and a rotating member that rotates according to the rotation of the wheels of the vehicle. A rotation speed sensor. When the first output value of the acceleration sensor at the first time point when the absolute value of the rotation speed is zero is smaller than the predetermined value, the control device determines that the vehicle is stopped on the uphill road that is steeper than the predetermined gradient. A first determination unit, a start unit for starting execution of increase control for increasing the belt clamping pressure when the vehicle is stopped on an uphill road, and an absolute value of the rotation speed after the increase control is started When the second output value of the acceleration sensor at the second time point when it is detected that the value has changed from zero to a value greater than zero is smaller than the first output value, it is determined that the rotational direction of the rotating member is the reverse direction. And a third output value of the acceleration sensor at the third time point after the absolute value of the rotational speed becomes zero again after it is determined that the rotation direction of the rotating member is the reverse direction. If the value is greater than the value, the rotation direction of the rotating member is not the reverse direction And a stop unit that stops execution of the increase control in response to the absolute value of the rotation speed exceeding a predetermined value after it is determined that the rotation direction of the rotating member is not the reverse direction. Including.

  According to the present invention, it is not possible to directly detect the rotation direction of the acceleration sensor that detects the acceleration in the longitudinal direction of the vehicle and the wheel (or the rotating member that rotates in accordance with the rotation of the wheel) (the absolute value of the rotation speed is detected). In a vehicle equipped with a rotational speed sensor, the rotational direction of the wheel, that is, the slippage at the start of the uphill road, the output of the acceleration sensor (acceleration in the forward direction of the vehicle) and the output of the rotational speed sensor (the absolute value of the rotational speed) The belt clamping pressure is controlled according to the determination result. Therefore, the start timing and stop timing of the belt clamping pressure increase can be appropriately set according to the start timing of the sliding down and the return timing from the sliding down. Therefore, it is possible to appropriately suppress the belt slip at the start of the uphill road while suppressing the deterioration of the durability of the belt.

It is a figure which shows the power train of the vehicle containing the control apparatus of the belt-type continuously variable transmission which concerns on this Embodiment. It is a flowchart of the process which ECU performs. It is a timing chart of belt clamping pressure up control, reverse rotation flag, G sensor value, and vehicle speed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  With reference to FIG. 1, a power train of a vehicle including a control device for a belt-type continuously variable transmission according to the present embodiment will be described.

  As shown in FIG. 1, the power train of this vehicle includes an engine 100, a torque converter 200, a forward / reverse switching device 290, a belt-type continuously variable transmission mechanism 300, a differential gear 800, an ECU 1000, a hydraulic control unit. 1100. The continuously variable transmission includes a torque converter 200, a forward / reverse switching device 290, a belt-type continuously variable transmission mechanism 300, and a hydraulic control unit 1100.

  The output shaft of engine 100 is connected to the input shaft of torque converter 200. Engine 100 and torque converter 200 are connected by a rotating shaft.

  The torque converter 200 includes a lock-up clutch 210 that directly connects the input shaft and the output shaft, a pump impeller 220 on the input shaft side, a turbine impeller 230 on the output shaft side, and a one-way clutch 250. It is comprised from the stator 240 which expresses an amplification function. Torque converter 200 and belt type continuously variable transmission mechanism 300 are connected by a rotating shaft.

  An oil pump 260 is provided between the torque converter 200 and the belt type continuously variable transmission mechanism 300. The oil pump 260 is a gear pump, for example, and operates as the pump impeller 220 on the input shaft side rotates. The oil pump 260 supplies hydraulic pressure to various solenoids of the hydraulic control unit 1100.

  Belt type continuously variable transmission mechanism 300 is connected to torque converter 200 with forward / reverse switching device 290 interposed. The belt-type continuously variable transmission mechanism 300 includes an input-side primary pulley 500, an output-side secondary pulley 600, and a belt 700 wound around the primary pulley 500 and the secondary pulley 600. Primary pulley 500 includes a fixed sheave fixed to the primary shaft and a movable sheave supported on the primary shaft so as to be slidable only. The secondary pulley 600 includes a fixed sheave fixed to the secondary shaft and a movable sheave supported by the secondary shaft so as to be slidable only.

  The belt 700 is an endless metal belt in which a large number of metal elements are bound together by a hoop that is an annular metal band.

  Hydraulic oil is supplied to and discharged from hydraulic actuators (both not shown) of the primary pulley 500 and the secondary pulley 600, respectively. The speed change is performed by continuously changing the groove width between the fixed sheave and the movable sheave of each of the pulleys 500 and 600 so that the belt winding radius is changed to a large or small size.

  The hydraulic control unit 1100 controls the hydraulic pressure supplied to the hydraulic actuator of the primary pulley 500 so that the transmission gear ratio becomes a gear ratio that matches the rotational speed of the primary pulley 500 with the target rotational speed. Further, the hydraulic control unit 1100 is supplied to the hydraulic actuator of the secondary pulley 600 so as to develop a tension necessary for transmitting the torque by pressing the movable sheave of the secondary pulley 600 toward the fixed sheave to sandwich the belt. Control the hydraulic pressure.

  The forward / reverse switching device 290 includes a double pinion planetary gear, a reverse (reverse) brake B1 and an input clutch C1. In the planetary gear, its sun gear is connected to the input shaft, the carrier CR supporting the first and second pinions P1, P2 is connected to the primary side fixed sheave, and the ring gear R is a reverse friction engagement element. The reverse brake B1 is connected, and an input clutch C1 is interposed between the carrier CR and the ring gear R. This input clutch C1 is also called a forward clutch or a forward clutch, and is always used in an engaged state when a vehicle other than the parking (P) position, the R position, and the N position moves forward.

  The ECU 1000 is connected to a turbine rotational speed sensor 400, a primary pulley rotational speed sensor 410, a secondary pulley rotational speed sensor 420, and an engine rotational speed sensor 430. Turbine rotational speed sensor 400 detects output shaft rotational speed NT (turbine rotational speed NT) of torque converter 200. Primary pulley rotation speed sensor 410 detects rotation speed NIN of primary pulley 500. Secondary pulley rotation speed sensor 420 detects rotation speed NOUT of secondary pulley 600. Engine rotation speed sensor 430 detects a rotation speed NE (engine rotation speed NE) of the output shaft of engine 100. The input shaft rotation speed (pump rotation speed) of torque converter 200 is the same as engine rotation speed NE.

  Further, the ECU 1000 is connected to a vehicle speed sensor 440, an accelerator opening sensor 450, a brake pedal force sensor 460, and a G sensor 470.

  The vehicle speed sensor 440 detects the absolute value of the rotational speed of the drive shaft that rotates in accordance with the rotation of the wheel (not shown), and detects the vehicle speed V based on the detected absolute value of the rotational speed of the drive shaft. That is, the vehicle speed sensor 440 can detect the rotational speed of the drive shaft, but cannot detect the rotational direction. Therefore, the vehicle speed V, which is the output value of the vehicle speed sensor 440, is a value indicating the absolute value of the actual vehicle speed to the last. Note that the detection range of the vehicle speed sensor 440 is a range that is not less than a very small predetermined speed. Further, the detection target of the rotational speed of the vehicle speed sensor 440 may be a rotating member that rotates according to the rotation of the wheel, and is not limited to the drive shaft. For example, the rotational speed of the secondary pulley 600 or the differential gear 800 may be detected.

  The accelerator opening sensor 450 detects an operation amount (accelerator opening) ACC of an accelerator pedal operated by the driver. The brake pedal force sensor 460 detects the pedal force of the brake pedal operated by the driver (the force with which the driver steps on the brake pedal).

  G sensor 470 detects the longitudinal acceleration of the vehicle. The detected value of the G sensor 470 shows a higher value as the acceleration in the forward direction of the vehicle is larger.

Each sensor described above outputs a signal indicating the detection result to ECU 1000.
The ECU 1000 stores an input interface for receiving information from each sensor, various information, a program, a threshold value, a map, and the like. A storage unit from which data is read and stored as necessary, an input interface, and An arithmetic processing unit that performs arithmetic processing based on information from the storage unit, and an output interface that outputs processing results of the arithmetic processing unit to each device.

  The hydraulic control unit 1100 includes a transmission speed control unit 1110, a belt clamping pressure control unit 1120, a line pressure control unit 1130, a lockup engagement pressure control unit 1132, a clutch pressure control unit 1140, and a manual valve 1150. Including.

  The shift speed control unit 1110 is configured to change the primary hydraulic pressure (the hydraulic pressure of the primary pulley 500 according to the output hydraulic pressure of the shift control duty solenoid (1) 1200 and the shift control duty solenoid (2) 1210 according to the vehicle speed and the accelerator opening. The hydraulic pressure supplied to the actuator). The control of the primary oil pressure controls the gear ratio and the speed of change of the gear ratio (shift speed).

  The belt clamping pressure control unit 1120 controls the secondary hydraulic pressure (the hydraulic pressure supplied to the hydraulic actuator of the secondary pulley 600) according to the output hydraulic pressure of the belt clamping pressure control linear solenoid 1220. The belt clamping pressure is controlled by controlling the secondary hydraulic pressure. The input shaft torque may be estimated from, for example, the output torque of engine 100 based on the engine rotation speed, the intake air amount, and the like and the torque ratio in torque converter 200, or may be directly detected.

  The line pressure control unit 1130 controls the line pressure according to the output hydraulic pressure of the line pressure control linear solenoid 1230. The line pressure is a hydraulic pressure obtained by adjusting the output hydraulic pressure of the oil pump 260 by a regulator valve (not shown).

  The lockup engagement pressure control unit 1132 controls the lockup clutch 210 according to the output hydraulic pressure to the lockup engagement pressure control duty solenoid 1240.

  The manual valve 1150 operates in conjunction with the driver's operation of the shift lever to switch the oil passage.

  When the input clutch C1 or the reverse brake B1 is engaged, the clutch pressure control unit 1140 regulates the output hydraulic pressure of the line pressure control linear solenoid 1230, thereby allowing the input clutch C1 or the reverse brake B1 to pass through the manual valve 1150. The hydraulic pressure supplied to the is controlled.

  The ECU 1000 includes a shift control duty solenoid (1) 1200, a shift control duty solenoid (2) 1210, a belt clamping pressure control linear solenoid 1220, a line pressure control linear solenoid 1230, and a lockup engagement pressure control. Control signals are output to the duty solenoids 1240, respectively. Thereby, the output hydraulic pressure of each solenoid is controlled.

  When the driver depresses the accelerator pedal, ECU 1000 sets a target engine output according to the vehicle speed and the accelerator opening. ECU 1000 sets the target gear ratio (or target primary rotational speed) so that the set target engine output can be realized on the optimum fuel consumption line of engine 100.

  ECU 1000 feedback-controls the control signal for each solenoid so that the actual gear ratio (a value obtained by dividing detected value NIN of primary pulley rotational speed sensor 410 by detected value NOUT of secondary pulley rotational speed sensor 420) approaches the target gear ratio. To do.

  When a vehicle with a belt-type continuously variable transmission as described above is stopped on an uphill road and the driver switches from the brake pedal to the accelerator pedal in order to move the vehicle forward (when starting up the uphill road) In addition, the vehicle may slip down (a phenomenon in which the vehicle moves backward against the driver's intention).

  When the sliding occurs, unlike the normal driving state, the reverse rotation of the driving wheel is transmitted to the secondary pulley 600 via the differential gear 800. Therefore, although the forward torque is input from the belt 700 to the secondary pulley 600, the secondary pulley 600 rotates in the reverse direction (hereinafter also referred to as “reverse drive state”).

  In this reverse drive state, there is a concern that the torque capacity (transmittable torque) of the belt-type continuously variable transmission mechanism 300 decreases and belt slippage occurs.

  The reason why the torque capacity decreases in the reverse drive state is considered to be that a gap is generated between each element of the belt 700 in contact with the secondary pulley 600. That is, in a normal driving state, the direction of the torque input from the belt 700 to the secondary pulley 600 matches the direction of rotation of the secondary pulley 600, and the elements of the belt 700 in contact with the secondary pulley 600 are clogged and tight. Become. On the other hand, in the reverse drive state, the direction in which the input torque is applied and the rotation direction of the secondary pulley 600 are reversed, and a partial gap is generated between each element of the belt 700 that is in contact with the secondary pulley 600. This gap between the elements is considered to be one of the causes of a decrease in torque capacity in the reverse drive state.

  Therefore, the ECU 1000 controls the belt clamping pressure increase control to increase the belt clamping pressure when the vehicle is completely stopped on the climbing road having a predetermined slope or more in order to suppress the belt slip caused by the slippage at the start of the climbing road. Start running. Specifically, the secondary hydraulic pressure is increased by controlling the belt clamping pressure control linear solenoid 1220.

  However, if the oil pressure is increased unnecessarily, it leads to a decrease in efficiency (deterioration of fuel consumption) and deterioration of belt durability. For this reason, it is desirable to perform the belt clamping pressure up control only when the vehicle is in the sliding state. However, since the vehicle speed sensor 440 cannot detect the traveling direction of the vehicle (the rotation direction of the wheels), it is difficult to determine the sliding state. .

  Therefore, ECU 1000 according to the present embodiment starts and starts sliding down based on the detection value (G sensor value) of G sensor 470 and the detection value of vehicle speed sensor 440 after the start of the belt clamping pressure up control. It is characterized in that it has a function of estimating the return from the fall and stopping the execution of the belt clamping pressure increase control when the return from the fall is stable.

  More specifically, ECU 1000 determines whether or not the sliding has started based on the relationship between the G sensor value at the time of stopping on the uphill road and the G sensor value at the start of vehicle speed detection (at the start of detection of wheel rotation). A function for determining whether or not the vehicle has returned from the slippage based on the relationship between the G sensor value when the vehicle stops on the uphill road and the G sensor value when the vehicle speed V becomes zero after the start of the slippage. This function has a function of stopping the belt clamping pressure up control when the state returned from the state is stabilized.

  The functions described above may be realized by software or hardware.

  FIG. 2 is a flowchart of processing of ECU 1000 when the above-described function is realized by software. This process is repeated at a predetermined cycle.

  As shown in FIG. 2, in step (hereinafter, step is abbreviated as S) 1, ECU 1000 detects G sensor value a when the vehicle is completely stopped, and G sensor value a is smaller than threshold value A. Determine whether or not. This judgment is based on whether or not the road surface on which the vehicle is stopped is a steep uphill road that causes a downhill (that is, whether it is an uphill road that requires belt clamping pressure increase). Judgment is based on the current G sensor value a (that is, the magnitude of the gravitational acceleration component in the longitudinal direction of the vehicle). Whether or not the vehicle is completely stopped can be determined, for example, based on whether or not the state where the brake pedal depressing force is equal to or greater than a predetermined value and the vehicle speed V is zero continues for a predetermined time. The G sensor value a when the vehicle is completely stopped is stored in a storage unit inside ECU 1000. If an affirmative determination is made in this process (YES in S1), it is determined that the road surface on which the vehicle is stopped is a steep uphill road that causes a downhill, and the process proceeds to S2. . Otherwise (NO in S1), it is determined that the road surface on which the vehicle is stopped is not a steep uphill road that causes a downhill, and the process ends.

In S2, ECU 1000 starts execution of belt clamping pressure up control.
In S3, ECU 1000 detects G sensor value b at the time of wheel rotation detection (when it is detected that the detected value of vehicle speed sensor 440 has changed from zero to a value greater than zero). It is determined whether b is smaller than the G sensor value a when the vehicle is completely stopped. In this determination, it is determined whether or not the vehicle has actually started to slide down by determining whether or not the acceleration in the backward direction at the time of detecting the rotation of the wheel has increased more than the acceleration at the time of complete stop of the vehicle. . If b <a (YES in S3), it is determined that the vehicle has started to slide because the acceleration in the reverse direction has increased, and the process proceeds to S4. If b> a (NO in S3), the acceleration in the reverse direction has decreased (the acceleration in the forward direction has increased), so it is determined that no slip has occurred (the vehicle is moving forward). Then, the process is terminated.

  In S4, ECU 1000 turns on the reverse rotation flag. Note that the reverse rotation flag is a flag indicating that a slip has occurred (reverse driving state). The reverse rotation flag is stored in a storage unit inside ECU 1000.

  In S5, ECU 1000 determines whether or not G sensor value c when reverse rotation flag is on (after the start of sliding down) and vehicle speed V becomes zero is larger than G sensor value a when the vehicle is completely stopped. Judging. This determination is made by determining whether or not the acceleration when the vehicle speed V becomes zero again after the start of slippage has increased in the forward direction relative to the acceleration when the vehicle is completely stopped, thereby determining the forward direction torque due to the accelerator operation or the like. Acts to determine whether or not the vehicle has returned from the sliding. If the reverse rotation flag is on and c> a (YES in S5), it is determined that the vehicle has returned from the slip, and the process proceeds to S6. If not (NO in S5), it is determined that the sliding is still continuing, and the process returns to S4.

In S6, ECU 1000 turns off the reverse rotation flag.
In S7, ECU 1000 determines whether vehicle speed V is equal to or higher than threshold value B, or whether vehicle speed V is equal to or higher than threshold value C (<B) for a predetermined time. This determination is to determine whether or not the state that has returned from the slip is stable. If a positive determination is made in this process (YES in S7), the process proceeds to S9. Otherwise (NO in S7), the process proceeds to S9.

  In S8, ECU 1000 performs a process similar to S1, that is, a process of determining whether or not G sensor value a when the vehicle is completely stopped is smaller than threshold A. This determination is based on the assumption that the vehicle has stopped again, and whether or not the road surface on which the vehicle has stopped is an uphill road with a slope that causes the vehicle to slide down. If an affirmative determination is made in this process (YES in S8), it is determined that the road surface on which the vehicle has been stopped is a steep uphill road that causes a downhill, the process is terminated, and the belt is clamped. Execution of the pressure up control is continued. Otherwise (NO in S8), it is determined that the road surface on which the vehicle has been stopped is not a steep uphill road that causes a downhill, and the process proceeds to S9.

  In S9, ECU 1000 stops execution of belt clamping pressure up control. As a result, the belt clamping pressure is lowered to a value before the start of the belt clamping pressure up control.

  The belt clamping pressure up control performed by ECU 1000 that is the control apparatus according to the present embodiment based on the above-described structure and flowchart will be described with reference to FIG. FIG. 3 is a timing chart of belt clamping pressure up control, reverse rotation flag, G sensor value, and vehicle speed when starting on an uphill road.

  In FIG. 3, in response to the start of the uphill road start at time t1, the vehicle descends at time t1 to t5, returns from the downhill at time t5, and the vehicle advances on the uphill road after time t5. It shows the state.

  In this case, ECU 1000 is an uphill road with a steep slope that causes a downhill when G sensor value a at time t1 (that is, when the vehicle is completely stopped) is smaller than threshold value A (YES in S1). Then, execution of belt clamping pressure up control is started (YES in S1, S2). By this belt clamping pressure up control, it is possible to suppress belt slip caused by slippage when starting uphill.

  Thereafter, until time t2, the vehicle moves backward at a very small speed at which vehicle speed V is not detected. When detection of vehicle speed V is started at time t2, it is determined that G sensor value b <a at time t2. (YES in S3), the reverse rotation flag indicating that the sliding has occurred is turned on (S4).

  Thereafter, when the reverse rotation flag is on (after the start of sliding down) and the G sensor value c at time t4 when the vehicle speed V becomes zero again is greater than the G sensor value a when the vehicle is completely stopped (in S5). YES), the reverse rotation flag is turned off (S6), assuming that the vehicle has recovered from the downhill.

  After that, at time 7 when the vehicle speed V becomes equal to or higher than the threshold value B (or when the vehicle speed V is equal to or higher than the threshold value C continues for a predetermined time), Execution of the pressure increase control is stopped (YES in S7, S8).

  As a result, even when the vehicle traveling direction (wheel rotation direction) cannot be detected, the return state from the actual sliding down is appropriately estimated, and the belt clamping pressure up control is appropriately stopped based on the estimation result. can do. Therefore, it is possible to suppress an unnecessary increase in the secondary hydraulic pressure, and to suppress a decrease in efficiency (deterioration in fuel consumption) and a deterioration in belt durability.

  As described above, the control device for a belt-type continuously variable transmission according to the present embodiment starts execution of belt clamping pressure up control when the vehicle is completely stopped on an uphill road having a predetermined slope or more. During execution of this belt clamping pressure up control, based on the detection results of the G sensor and the vehicle speed sensor that detects the absolute value of the vehicle speed, the start of the vehicle slip and the return from the slip are appropriately estimated, and the slip When the return from falling is stable, the belt clamping pressure up control is stopped. Therefore, it is possible to appropriately suppress the deterioration of fuel consumption and the deterioration of belt durability while appropriately suppressing the belt slip at the start of the uphill road.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  100 engine, 200 torque converter, 210 lock-up clutch, 220 pump impeller, 230 turbine impeller, 240 stator, 250 one-way clutch, 260 oil pump, 290 forward / reverse switching device, 300 belt type continuously variable transmission mechanism, 400 turbine rotation Speed sensor, 410 primary pulley rotational speed sensor, 420 secondary pulley rotational speed sensor, 430 engine rotational speed sensor, 440 vehicle speed sensor, 450 accelerator opening sensor, 460 brake pedal force sensor, 470 G sensor, 500 primary pulley, 600 secondary pulley, 700 belt, 800 differential gear, 1100 hydraulic control unit, 1110 shift speed control unit, 1120 belt clamping pressure control unit, 1130 line pressure control unit, 1132 Lock-up engagement pressure control unit, 1140 Clutch pressure control unit, 1150 Manual valve, 1220 Linear solenoid for belt clamping pressure control, 1230 Linear solenoid for line pressure control, 1240 Duty solenoid for lock-up engagement pressure control.

Claims (1)

A control device for a belt-type continuously variable transmission mounted on a vehicle, wherein the vehicle detects acceleration in the front-rear direction of the vehicle, and outputs a higher value as acceleration in the forward direction increases. A rotation speed sensor that detects an absolute value of the rotation speed of a rotating member that rotates in accordance with the rotation of a vehicle wheel;
The control device includes:
When the first output value of the acceleration sensor at the first time point when the absolute value of the rotational speed is zero is smaller than a predetermined value, it is determined that the vehicle is stopped on an uphill road that is steeper than a predetermined gradient. A first determination unit;
When the vehicle is stopped on the uphill road, a start unit for starting execution of increase control for increasing the clamping force of the belt;
The second output value of the acceleration sensor at the second time point after the increase control is started and when it is detected that the absolute value of the rotational speed has changed from zero to a value greater than zero is the first output value. A second determination unit that determines that the rotation direction of the rotating member is the reverse direction when
The third output value of the acceleration sensor at a third time point after the rotational direction of the rotating member is determined to be the reverse direction and the absolute value of the rotational speed becomes zero again is greater than the first output value. A third determining unit that determines that the rotational direction of the rotating member is not the reverse direction, if greater,
And a stop unit that stops execution of the increase control in response to the absolute value of the rotational speed exceeding a predetermined value after it is determined that the rotational direction of the rotating member is not the reverse direction. Control device for step transmission.

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