JP2013072516A - Hydraulic control device for belt type continuously variable transmission for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic control device for a belt type continuously variable transmission for a vehicle which enables easy determination of a failure location without adding a new structure.SOLUTION: In a feedback control in which an actual speed change ratio γ follows a target speed change ratio γ* in the continuously variable transmission 18, a primary pressure Pin is estimated based on a secondary pressure Pout, and it is determined either a secondary pressure sensor 78 or the secondary pressure Pout has an abnormality based on the comparative results between an estimated value Pines of the primary pressure Pin and a command value Pin*, and the comparative results between the actual speed change ratio γ and the target speed change ratio γ*. Therefore, it is determined either the secondary pressure sensor 78 or the secondary pressure Pout has an abnormality by estimating the primary pressure Pin from existing information without newly adding a structure.

Description

  The present invention relates to a hydraulic control device for a belt-type continuously variable transmission for a vehicle, and more particularly, to an improvement for easily determining a failure location without adding a new configuration.

  2. Description of the Related Art A vehicular continuously variable transmission that is connected to an engine and can change the output of the engine continuously is known. For example, a belt type continuously variable transmission or the like that changes the gear ratio by changing the engagement diameter of the belt while transmitting pressure by clamping the belt with hydraulic pressure. In such a belt type continuously variable transmission, a technique for detecting a failure related to hydraulic control has been proposed. For example, a control device for a belt-type continuously variable transmission described in Patent Document 1 is this. According to this technology, a belt-type continuously variable sensor comprising: a pressure sensor provided in an oil passage to a hydraulic chamber that generates a pressing force in the axial direction on the movable sheave; and a deflection sensor that detects a clamping pressure of the movable sheave. In the transmission, it is possible to detect an abnormality of the pressure sensor by estimating the pressure in the hydraulic chamber based on the detection result of the deflection sensor and comparing the estimation result with the detection result of the pressure sensor.

JP 2006-316892 A JP-A-2005-291111 JP 2010-096240 A

  However, in the prior art, it is necessary to newly provide a deflection sensor in order to detect an abnormality of the pressure sensor, which causes problems such as deterioration in mountability due to the addition of wiring and cost increase due to the cost of the sensor itself. It was a thing. Such a problem is not yet known and has been newly found by the present inventors in the course of research.

  The present invention has been made against the background of such circumstances, and the object of the present invention is to control the hydraulic pressure of a belt-type continuously variable transmission for a vehicle that can easily determine a failure location without adding a new configuration. To provide an apparatus.

  In order to achieve such an object, the gist of the first aspect of the present invention is that an input side variable pulley and an output side variable pulley whose effective diameter is variable are wound between the pair of variable pulleys. In a belt-type continuously variable transmission having a transmission belt, a belt-type continuously variable transmission for a vehicle that controls a first hydraulic pressure supplied to the input-side variable pulley and a second hydraulic pressure supplied to the output-side variable pulley, respectively. In a feedback control that includes a hydraulic sensor that detects a second hydraulic pressure supplied to the output-side variable pulley, and that causes an actual transmission ratio in the belt-type continuously variable transmission to follow a target transmission ratio. Estimating the first hydraulic pressure supplied to the input-side variable pulley based on the second hydraulic pressure detected by the hydraulic pressure sensor, and comparing the estimated value of the first hydraulic pressure with the command value; Wherein based on the result of the comparison for the target gear ratio of the actual speed ratio, and is characterized in that the abnormality in any of the hydraulic sensor and the second hydraulic pressure is determined whether has occurred.

  As described above, according to the first aspect of the present invention, the hydraulic pressure sensor that detects the second hydraulic pressure supplied to the output-side variable pulley is provided, and the actual speed ratio in the belt-type continuously variable transmission follows the target speed ratio. In feedback control, a first hydraulic pressure supplied to the input-side variable pulley is estimated based on a second hydraulic pressure detected by the hydraulic pressure sensor, and a comparison result of the estimated value of the first hydraulic pressure with respect to a command value; Based on the comparison result of the actual gear ratio with respect to the target gear ratio, it is to determine which of the hydraulic sensor and the second hydraulic pressure is abnormal, so without adding a new configuration, By estimating the first oil pressure based on existing information, it can be determined which of the oil pressure sensor and the second oil pressure is abnormal. That is, it is possible to provide a hydraulic control device for a vehicle belt-type continuously variable transmission that easily determines a failure location without adding a new configuration.

  The gist of the second invention, which is dependent on the first invention, is that the estimated value of the first hydraulic pressure is greater than a predetermined threshold with respect to the command value, and the actual gear ratio with respect to the target gear ratio. When the deviation is within a specified range, it is determined that an abnormality has occurred in the hydraulic sensor. In this way, occurrence of an abnormality in the hydraulic sensor can be easily determined without adding a new configuration.

  The gist of the third invention subordinate to the first invention is that a deviation of the estimated value of the first hydraulic pressure from a command value is within a specified range, and the actual gear ratio is a target gear ratio. When it deviates to the larger side, it is determined that an abnormality has occurred in the second hydraulic pressure. In this way, it is possible to easily determine the occurrence of an abnormality relating to the second hydraulic pressure without adding a new configuration.

It is a figure explaining the schematic structure of the power transmission path | route from the engine which comprises the vehicle to which this invention is applied suitably to a drive wheel. FIG. 2 is a block diagram illustrating a main part of a control system provided for controlling an engine, a continuously variable transmission, and the like in the vehicle of FIG. 1. FIG. 2 is a hydraulic circuit diagram showing a main part related to hydraulic control related to a shift of a continuously variable transmission in a hydraulic control circuit provided in the vehicle of FIG. 1. It is a functional block diagram explaining the principal part of the control function with which the electronic control apparatus of FIG. 2 was equipped. FIG. 2 is a diagram for explaining thrust necessary for shift control of a continuously variable transmission in the vehicle of FIG. 1. FIG. 6 is a thrust relationship diagram at a predetermined point in FIG. 5. FIG. 2 is a block diagram showing a control structure for achieving both target shift and belt slip prevention with a minimum necessary thrust in the continuously variable transmission in the vehicle of FIG. 1. It is a figure which shows an example of the speed change map used when calculating | requiring the target input shaft rotational speed in the hydraulic control regarding the speed change of a continuously variable transmission. It is a figure which shows an example of the map previously calculated | required experimentally and memorize | stored in advance of engine rotation speed and engine torque by making intake air quantity into a parameter. It is a figure which shows an example of the map previously calculated | required experimentally as a predetermined operating characteristic of a torque converter, and was memorize | stored. It is a figure which shows an example of the thrust ratio map calculated | required experimentally beforehand and memorize | stored with the target speed ratio as a parameter and the reciprocal number of a safety factor, and a thrust ratio. It is a figure which shows an example of the thrust ratio map calculated | required experimentally beforehand and memorize | stored with the target speed ratio as a parameter and the reciprocal number of a safety factor, and a thrust ratio. FIG. 3 is a time chart showing changes with time of each relational value when an abnormality that actually increases the secondary pressure occurs in the feedback control of the transmission ratio by the electronic control device of FIG. 2. FIG. FIG. 3 is a time chart showing a change with time of each relationship value when an abnormality occurs in which the detection value of the secondary pressure sensor is on the high pressure side in the feedback control of the transmission ratio by the electronic control device of FIG. 2. FIG. 3 is a time chart showing a change with time of each relational value when an abnormality occurs in which the detection value of the secondary pressure sensor becomes a low pressure side in the feedback control of the transmission ratio by the electronic control device of FIG. 2. It is a flowchart explaining the principal part of the failure location determination control by the electronic controller of FIG.

  Preferably, when the difference between the detected value detected by the hydraulic sensor and the command value of the second hydraulic pressure supplied to the output-side variable pulley is equal to or greater than a predetermined threshold, the hydraulic system is Control is performed to determine which of the hydraulic pressure sensor and the second hydraulic pressure is abnormal, assuming that some abnormality has occurred.

  Preferably, the first hydraulic pressure supplied to the input-side variable pulley is estimated based on the second hydraulic pressure detected by the hydraulic pressure sensor, and the estimated value of the first hydraulic pressure is predetermined with respect to the command value. If the difference between the actual speed ratio and the target speed ratio is within a specified range and is greater than the threshold, it is determined that an abnormality has occurred in which the detected value of the hydraulic sensor is shifted to a higher pressure side than the actual pressure. Is.

  Preferably, the first hydraulic pressure supplied to the input side variable pulley is estimated based on the second hydraulic pressure detected by the hydraulic pressure sensor, and the deviation of the estimated value of the first hydraulic pressure from the command value is within a specified range. When the actual gear ratio deviates from the target gear ratio to the larger side, there is an abnormality that the second hydraulic pressure actually increases (becomes larger than the command value). It is determined.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating a schematic configuration of a power transmission path from an engine 12 to a drive wheel 24 constituting a vehicle 10 to which the present invention is preferably applied. In FIG. 1, the power generated by the engine 12 that is a driving power source for traveling is converted into a torque converter 14 that is a fluid transmission device, a forward / reverse switching device 16, and a belt-type continuously variable transmission 18 for a vehicle (hereinafter referred to as a “power transmission”) (Hereinafter simply referred to as a continuously variable transmission 18), a reduction gear device 20, a differential gear device 22, etc., are sequentially transmitted to a pair of left and right drive wheels 24.

  The torque converter 14 is connected to the forward / reverse switching device 16 via a pump impeller 14p connected to the crankshaft 26 of the engine 12 and a turbine shaft 30 corresponding to an output side member of the torque converter 14. A turbine impeller 14t is provided to transmit power through a fluid. A lock-up clutch 14l is provided between the pump impeller 14p and the turbine impeller 14t, and the pump impeller 14p and the turbine impeller 14t rotate integrally when the lock-up clutch 141 is completely engaged. It is supposed to be made. The pump impeller 14p controls the speed of the continuously variable transmission 18, generates a belt clamping pressure in the continuously variable transmission 18, controls the torque capacity of the lockup clutch 14l, Mechanical hydraulic pressure generated by rotating the engine 12 to drive hydraulic pressure for switching the power transmission path in the advance switching device 16 and supplying lubricating oil to each part of the power transmission path of the vehicle 10. An oil pump 28 is connected.

  The forward / reverse switching device 16 is composed mainly of a forward clutch C1, a reverse brake B1, and a double pinion type planetary gear device 16p, and the turbine shaft 30 of the torque converter 14 is integrated with a sun gear 16s. The input shaft 32 of the continuously variable transmission 18 is integrally connected to the carrier 16c, while the carrier 16c and the sun gear 16s are selectively connected via the forward clutch C1. The ring gear 16r is selectively fixed to a housing 34 as a non-rotating member via a reverse brake B1. Each of the forward clutch C1 and the reverse brake B1 is preferably a hydraulic friction engagement device that is frictionally engaged by a hydraulic cylinder.

  In the forward / reverse switching device 16 configured as described above, when the forward clutch C1 is engaged and the reverse brake B1 is released, the forward / reverse switching device 16 is brought into an integral rotation state. As a result, the turbine shaft 30 is directly connected to the input shaft 32, and the forward power transmission path is established (achieved), so that the driving force in the forward direction is transmitted to the continuously variable transmission 18 side. When the reverse brake B1 is engaged and the forward clutch C1 is released, the forward / reverse switching device 16 establishes (achieves) a reverse power transmission path, and the input shaft 32 is a turbine shaft. Thus, the drive force in the reverse direction is transmitted to the continuously variable transmission 18 side. When both the forward clutch C1 and the reverse brake B1 are released, the forward / reverse switching device 16 is in a neutral state (power transmission cut-off state) in which power transmission is cut off.

The engine 12 is an internal combustion engine such as a gasoline engine or a diesel engine, and functions as a driving force source (main power source) in the vehicle 10. The intake pipe 36 of the engine 12 is provided with an electronic throttle valve 40 for electrically controlling the intake air amount Q _AIR of the engine 12 using a throttle actuator 38 as shown in FIG.

  The continuously variable transmission 18 includes an input side member provided on the input shaft 32 and a primary pulley (primary sheave) 42 that is an input side variable pulley having a variable effective diameter, and an output side provided on the output shaft 44. A secondary pulley (secondary sheave) 46 (hereinafter simply referred to as variable pulleys 42 and 46 unless otherwise specified), which is an output side variable pulley having a variable effective diameter, and a pair of variable pulleys 42 and 46. A transmission belt 48 wound around is provided. With such a configuration, in the continuously variable transmission 18, power is transmitted through the frictional force between the pair of variable pulleys 42 and 46 and the transmission belt 48. The transmission belt 48 has, for example, an endless annular shape as a whole, and is superposed in the thickness direction in a state of being in close contact with each other along a pair of endless annular tape-like hoops (belts). And a large number of elements (frames). This element is formed with a pair of hoop engagement grooves formed so as to open to the side, and the pair of hoops are engaged with the hoop engagement grooves.

  The primary pulley 42 is a fixed rotating body (fixed sheave) 42a as an input-side fixed rotating body fixed to the input shaft 32, and is not rotatable relative to the input shaft 32 and is movable in the axial direction. A movable rotating body (movable sheave) 42b as an input side movable rotating body provided on the input side, and an input side thrust (primary thrust) Win (= primary pressure) in the primary pulley 42 for changing the V groove width between them. A primary side hydraulic cylinder (input side hydraulic cylinder) 42c as a hydraulic actuator that provides (Pin × pressure receiving area) is provided. The secondary pulley 46 is a fixed rotating body (fixed sheave) 46a as an output side fixed rotating body fixed to the output shaft 44, and the output shaft 44 is not rotatable relative to the output shaft 44 and is movable in the axial direction. The output side thrust (secondary thrust) Wout (= secondary pressure) in the secondary pulley 46 for changing the width of the V-groove between the movable rotor (movable sheave) 46b as the output-side movable rotor provided in A secondary side hydraulic cylinder (output side hydraulic cylinder) 46c as a hydraulic actuator that applies (Pout × pressure receiving area) is provided.

As shown in FIG. 3 to be described later, the primary pressure Pin that is the hydraulic pressure to the oil chamber 42d of the primary hydraulic cylinder 42c and the secondary pressure Pout that is the hydraulic pressure to the oil chamber 46d of the secondary hydraulic cylinder 46c are the vehicle The pressure control is independently controlled by the hydraulic control circuit 100 provided in the system 10. Thereby, the primary thrust Win that is the thrust in the primary pulley 42 and the secondary thrust Wout that is the thrust in the secondary pulley 46 are controlled directly or indirectly, respectively, so that the pair of variable pulleys 42 and 46 The width of each V-groove changes to change the engagement diameter (effective diameter) of the transmission belt 48, and the gear ratio (gear ratio) γ (= input shaft rotational speed N _IN / output shaft rotation) of the continuously variable transmission 18 Speed N _OUT ) is continuously changed, and a frictional force (belt clamping pressure) between the pair of variable pulleys 42 and 46 and the transmission belt 48 is set so that the transmission belt 48 does not slip. Be controlled.

In the continuously variable transmission 18, the primary thrust Win and the secondary thrust Wout are controlled as described above, so that the actual transmission ratio (actual transmission ratio) γ is targeted while preventing the transmission belt 48 from slipping. The transmission ratio is γ ^* . Here, the input shaft rotational speed N _IN is the rotational speed of the input shaft 32, and the output shaft rotational speed N _OUT is the rotational speed of the output shaft 44. As is apparent from FIG. 1, in this embodiment, the input shaft rotational speed N _IN is the same as the primary pulley 42 rotational speed, and the output shaft rotational speed N _OUT is the same as the secondary pulley 46 rotational speed. is there.

In the continuously variable transmission 18, for example, when the primary pressure Pin is increased, the V groove width of the primary pulley 42 is narrowed to reduce the speed ratio γ. That is, the continuously variable transmission 18 is upshifted by increasing the primary pressure Pin. When the primary pressure Pin is lowered, the V groove width of the primary pulley 42 is increased and the speed ratio γ is increased. That is, the continuously variable transmission 18 is downshifted by decreasing the primary pressure Pin. Therefore, when the V groove width of the primary pulley 42 is minimized, the minimum speed ratio γmin (highest speed side speed ratio, maximum Hi) is achieved as the speed ratio γ of the continuously variable transmission 18. When the V-groove width of the primary pulley 42 is maximized, the maximum gear ratio γmax (lowest speed side gear ratio, lowest Low) is achieved as the gear ratio γ of the continuously variable transmission 18. In the continuously variable transmission 18, the primary pressure Pin (primary thrust Win also agrees) and the secondary pressure Pout (secondary thrust Wout also agrees) prevent the transmission belt 48 from slipping (belt slip), while the primary thrust The target speed change ratio γ ^* is realized by the mutual relationship between Win and the secondary thrust Wout, and the target speed change is not realized by only one pulley pressure (the thrust is also agreed).

  FIG. 2 is a block diagram illustrating a main part of a control system provided in the vehicle 10 for controlling the engine 12, the continuously variable transmission 18, and the like. The vehicle 10 of this embodiment is provided with an electronic control device 50 including a hydraulic control device for a vehicle belt-type continuously variable transmission related to, for example, shift control of the continuously variable transmission 18. The electronic control device 50 is configured to include a so-called microcomputer having, for example, a CPU, a RAM, a ROM, and an input / output interface, and the CPU is stored in advance in the ROM using a temporary storage function of the RAM. Various controls relating to the vehicle 10 are executed by performing signal processing according to a program. For example, the electronic control unit 50 performs output control of the engine 12, shift control of the continuously variable transmission 18, belt clamping pressure control, torque capacity control of the lockup clutch 14l, and the like. If necessary, it is divided into an engine control unit, a transmission control unit for the continuously variable transmission 18 and a hydraulic control unit for the lockup clutch 14l.

The electronic control device 50 is supplied with signals from various sensors and switches provided in the vehicle 10. For example, detected by the rotation angle (position) A _CR and the rotational speed signal representing the (engine rotational speed) N _E of the engine 12, a turbine rotational speed sensor 54 of the crankshaft 26 detected by the engine rotational speed sensor 52 A signal representing a rotational speed (turbine rotational speed) _NT of the turbine shaft 30; a signal representing an input shaft rotational speed N _IN which is an input rotational speed of the continuously variable transmission 18 detected by the input shaft rotational speed sensor 56; A signal representing the output shaft rotational speed N _OUT which is the output rotational speed of the continuously variable transmission 18 corresponding to the vehicle speed V detected by the output shaft rotational speed sensor 58, the electronic throttle valve 40 detected by the throttle sensor 60. signal representing the throttle valve opening theta _TH, a signal representing the cooling water temperature TH _W of the engine 12 detected by a coolant temperature sensor 62, intake Signal representing the intake air quantity Q _AIR of the engine 12 detected by the air flow sensor 64, the accelerator opening is an operation amount of the accelerator pedal as an acceleration demand of the detected driver by the accelerator opening sensor 66 A _CC , A signal indicating a brake-on B _ON indicating a state in which a foot brake as a service brake detected by the foot brake switch 68 is operated, a continuously variable transmission 18 detected by the CVT oil temperature sensor 70, etc. signal representative of the oil temperature TH _oIL of the working oil, lever lever position (operation position) of the shift lever detected by the position sensor 72 signals representative of P _SH, the battery temperature detected by the battery sensor 76 TH _BAT and the battery output current (Battery charge / discharge current) Signal representing I _BAT and battery voltage V _BAT , secondary oil pressure sensor A second oil pressure, that is, a signal representing the secondary pressure Pout, which is the oil pressure supplied to the secondary pulley 46 detected by the pressure sensor 78, is supplied. The electronic control device 50 sequentially calculates the state of charge (charge capacity) SOC of the battery (power storage device) based on, for example, the battery temperature TH _BAT , the battery charge / discharge current I _BAT , the battery voltage V _BAT , and the like. The electronic control unit 50 sequentially calculates the actual speed ratio γ (= N _IN / N _OUT ) of the continuously variable transmission 18 based on, for example, the output shaft rotational speed N _OUT and the input shaft rotational speed N _IN .

The electronic control device 50 outputs a signal for controlling the operation of each part in the vehicle 10. For example, an engine output control command signal S _E for output control of the engine 12, a hydraulic control command signal S _CVT for hydraulic control related to the shift of the continuously variable transmission 18, and the like are output. Specifically, as the engine output control command signal S _E , the throttle signal for controlling the opening / closing of the electronic throttle valve 40 by driving the throttle actuator 38, and the amount of fuel injected from the fuel injection device 80 are set. An injection signal for controlling, an ignition timing signal for controlling the ignition timing of the engine 12 by the ignition device 82, and the like are output. As the hydraulic control command signal S _CVT , a command signal for driving the linear solenoid valve SLP that regulates the primary pressure Pin, a command signal for driving the linear solenoid valve SLS that regulates the secondary pressure Pout, and the line hydraulic pressure P _L A command signal or the like for driving the linear solenoid valve SLT to be controlled is output to the hydraulic control circuit 100 described later with reference to FIG.

  FIG. 3 is a hydraulic circuit diagram showing a main part related to hydraulic control (shift pressure control) related to shifting of the continuously variable transmission 18 in the hydraulic control circuit 100 provided in the vehicle 10. As shown in FIG. 3, the hydraulic control circuit 100 includes, for example, the mechanical oil pump 28, a primary pressure control valve 110 that regulates the primary pressure Pin, a secondary pressure control valve 112 that regulates the secondary pressure Pout, A primary regulator valve (line hydraulic pressure regulating valve) 114, a modulator valve 116, a linear solenoid valve SLT, a linear solenoid valve SLP, a linear solenoid valve SLS, and the like are provided.

The line oil pressure P _L is based on, for example, the control oil pressure P _SLT that is the output oil pressure of the linear solenoid valve SLT by the relief type primary regulator valve 114 using the operating oil pressure output (generated) from the oil pump 28 as a source pressure. The pressure is adjusted to a value according to the engine load and the like. Specifically, the line oil pressure P _L is based on a control oil pressure P _SLT that is set to obtain a hydraulic pressure obtained by adding a predetermined margin (margin) to the higher hydraulic pressure of the primary pressure Pin and the secondary pressure Pout. It is regulated. Therefore, it is avoided that the line oil pressure P _L which is the original pressure is insufficient in the pressure adjusting operation of the primary pressure control valve 110 and the secondary pressure control valve 112, and the line oil pressure P _L is not increased unnecessarily. Is possible. Modulator pressure P _M, the electronic control unit control pressure P _SLT that is controlled by 50, the linear solenoid valve SLP output hydraulic and is controlled oil pressure P _SLP, and the linear solenoid valve outputs the hydraulic pressure in a control pressure P _SLS of SLS And is regulated to a constant pressure by the modulator valve 116 using the line oil pressure P _L as a source pressure.

The primary pressure control valve 110 is provided so as to be movable in the axial direction so as to open and close the input port 110i and supply the line oil pressure P _L from the input port 110i to the primary pulley 42 via the output port 110t. 110a, a spring 110b as an urging means for urging the spool valve element 110a in the valve opening direction, and a control hydraulic pressure for accommodating the spring 110b and applying thrust in the valve opening direction to the spool valve element 110a An oil chamber 110c that receives P _SLP , a feedback oil chamber 110d that receives the line oil pressure P _L output from the output port 110t to give a thrust in the valve closing direction to the spool valve element 110a, and a spool valve element 110a receiving the modulator pressure P _M in order to impart a closing direction of thrust An oil chamber 110e is provided.

Primary pressure control valve 110 configured as described above, for example, supplied to the control oil pressure P primary hydraulic cylinder 42c of the _SLP line pressure P _L temper pressure control to the pilot pressure the primary pulley 42 (42d oil chamber) To do. As a result, the primary pressure Pin that is the first hydraulic pressure supplied to the primary hydraulic cylinder 42c is controlled. For example, when the control hydraulic pressure P _SLP output from the linear solenoid valve _SLP is increased from a state where a predetermined hydraulic pressure is supplied to the primary hydraulic cylinder 42c, the spool valve element 110a of the primary pressure control valve 110 is Move to the upper side of FIG. Thereby, the primary pressure Pin to the primary hydraulic cylinder 42c is increased. On the other hand, when the control hydraulic pressure P _SLP output from the linear solenoid valve _SLP is lowered from the state where a predetermined hydraulic pressure is supplied to the primary hydraulic cylinder 42c, the spool valve element 110a of the primary pressure control valve 110 is reduced. Moves downward in FIG. As a result, the primary pressure Pin to the primary hydraulic cylinder 42c is reduced.

  An orifice 120 is provided in the oil supply / discharge conduit for the primary pulley 42, that is, the oil passage 118 between the primary hydraulic cylinder 42 c (oil chamber 42 d) and the primary pressure control valve 110 for the purpose of failsafe or the like. It has been. By providing the orifice 120, for example, even if the linear solenoid valve SLP fails, the internal pressure of the primary hydraulic cylinder 42c is not suddenly reduced. Thereby, for example, sudden deceleration of the vehicle 10 due to a failure of the linear solenoid valve SLP is suppressed.

The secondary pressure control valve 112 is provided so as to be movable in the axial direction, thereby opening and closing the input port 112i and supplying the line oil pressure P _L from the input port 112i to the secondary pulley 46 via the output port 112t as the secondary pressure Pout. A spool valve element 112a, a spring 112b as an urging means for urging the spool valve element 112a in the valve opening direction, and the spring valve 112b is accommodated and imparts thrust in the valve opening direction to the spool valve element 112a. An oil chamber 112c that receives the control hydraulic pressure P _SLS to perform the above operation, a feedback oil chamber 112d that receives the secondary pressure Pout output from the output port 112t in order to give a thrust in the valve closing direction to the spool valve element 112a, Applies thrust in the valve closing direction to the spool valve element 112a An oil chamber 112e that accepts modulator pressure P _M in order, comprises.

Secondary pressure control valve 112 configured as described above, for example, supplied to the control oil pressure P _SLS secondary side hydraulic cylinder 46c of the secondary pulley 46 by the line pressure P _L as a pilot pressure regulating control to control (oil chamber 46d) To do. Thereby, the secondary pressure Pout that is the second hydraulic pressure supplied to the secondary hydraulic cylinder 46c is controlled. For example, when the control hydraulic pressure P _SLS output from the linear solenoid valve _SLS is increased from a state in which a predetermined hydraulic pressure is supplied to the secondary hydraulic cylinder 46c, the spool valve element 112a of the secondary pressure control valve 112 is Move to the upper side of FIG. As a result, the secondary pressure Pout to the secondary hydraulic cylinder 46c is increased. On the other hand, when the control hydraulic pressure P _SLS output from the linear solenoid valve _SLS is lowered from the state where a predetermined hydraulic pressure is supplied to the secondary hydraulic cylinder 46c, the spool valve element 112a of the secondary pressure control valve 112 is reduced. Moves downward in FIG. As a result, the secondary pressure Pout to the secondary hydraulic cylinder 46c is reduced.

  An oil supply / discharge conduit for the secondary pulley 46, that is, an oil passage 122 between the secondary hydraulic cylinder 46c (oil chamber 46d) and the secondary pressure control valve 112, is provided with an orifice 124 for the purpose of fail-safe or the like. It has been. By providing the orifice 124, for example, even if the linear solenoid valve SLS breaks down, the internal pressure of the secondary hydraulic cylinder 46c is not suddenly reduced. Thereby, for example, belt slippage due to a failure of the linear solenoid valve SLS is prevented.

  In the hydraulic control circuit 100 configured as described above, for example, the primary pressure Pin regulated by the linear solenoid valve SLP and the secondary pressure Pout regulated by the linear solenoid valve SLS are transmitted through the transmission belt 48 and the variable pulley 42. , 46 is controlled so as to generate a belt clamping pressure which does not cause slippage between the pair of variable pulleys 42, 46 and does not increase unnecessarily. As will be described later, the continuously variable transmission 18 is obtained by changing the thrust ratio τ (= Wout / Win) of the pair of variable pulleys 42 and 46 in accordance with the mutual relationship between the primary pressure Pin and the secondary pressure Pout. Is changed. For example, the gear ratio γ is increased as the thrust ratio τ is increased (that is, the continuously variable transmission 18 is downshifted).

FIG. 4 is a functional block diagram for explaining the main part of the control function provided in the electronic control unit 50. The transmission hydraulic pressure control unit 130 shown in FIG. 4 performs transmission pressure control for controlling the transmission ratio γ in the continuously variable transmission 18. For example, the command value (or target primary pressure Pin ^* ) of the primary pressure Pin is set so as to achieve the target speed ratio γ ^* of the continuously variable transmission 18 while preventing belt slippage of the continuously variable transmission 18. Primary command pressure Pintgt and secondary command pressure Pouttgt as a command value (or target secondary pressure Pout ^* ) of the secondary pressure Pout are determined, and the primary command pressure Pintgt and the secondary command pressure Pouttgt are determined by the hydraulic control circuit 100. Output to. That is, in the present embodiment, the electronic control device 50 corresponds to a hydraulic control device for a belt type continuously variable transmission. As shown in FIG. 4, the shift hydraulic pressure control unit 130 calculates, for example, a slip limit thrust calculation unit 132 that calculates a slip limit thrust Wlmt, a steady thrust calculation unit 134 that calculates a balance thrust Wbl, and a shift difference thrust ΔW. A differential thrust force calculation unit 136 for calculating the feedback control amount Winfb and a feedback control amount calculation unit 138 for calculating the feedback control amount Winfb. These control functions will be described later.

The actual speed ratio calculation unit 140 calculates the actual speed ratio γ in the continuously variable transmission 18. Specifically, based on the output shaft rotational speed N _OUT detected by the output shaft rotational speed sensor 58 and the input shaft rotational speed N _IN detected by the input shaft rotational speed sensor 56, the ratio is The actual speed ratio γ (= N _IN / N _OUT ) of the continuously variable transmission 18 is calculated. The actual transmission ratio calculation unit 140 may be included in the transmission hydraulic pressure control unit 130.

The primary pulley hydraulic pressure estimation unit 142 supplies the primary hydraulic cylinder 42c based on the second hydraulic pressure detected by the secondary pressure sensor 78, which is a hydraulic pressure sensor, that is, the secondary pressure Pout supplied to the secondary hydraulic cylinder 46c. The primary pressure Pin that is the first hydraulic pressure is estimated. For example, a value (= Wines / Ain) obtained by dividing the estimated value Wines of the primary thrust Win that is the thrust of the primary hydraulic cylinder 42c in the primary pulley 42 by the pressure receiving area Ain of the primary pulley 42 is an estimated value of the primary pressure Pin. Calculated as Pines. The estimated value Wines of the primary thrust Win is, for example, a value (= Wout / τes) obtained by dividing the secondary thrust Wout, which is the thrust of the secondary hydraulic cylinder 46c in the secondary pulley 46, by the estimated thrust ratio τes. This estimated thrust ratio τes is calculated based on the actual transmission ratio γ and the input torque T _IN in the continuously variable transmission 16 from a relationship experimentally obtained in advance (a relationship determined by the mechanical configuration), for example. . As will be described later, the input torque T _IN is calculated, for example, as a value (= T _E × t) obtained by multiplying the engine torque T _E by the torque ratio t of the torque converter 14. The secondary thrust Wout is a product (= Pout × Aout) of the secondary pressure Pout detected by the secondary pressure sensor 78 and the pressure receiving area Aout of the secondary pulley 46.

The hydraulic control circuit 100 according to the present embodiment has an actual secondary pressure acting on the secondary pulley 46 (secondary hydraulic cylinder 46c) only on the secondary pulley 46 side which is one side of the pair of variable pulleys 42 and 46. A secondary pressure sensor 78 is provided as a hydraulic pressure sensor for detecting Pout. In other words, it does not have a hydraulic sensor for detecting the actual primary pressure Pin acting on the primary pulley 42 (primary hydraulic cylinder 42c), and is estimated by the primary pulley hydraulic pressure estimation unit 142. For this reason, for example, the transmission hydraulic pressure control unit 130 executes feedback control in which the detected value of the secondary pressure sensor 78 (a signal indicating the actual secondary pressure Pout) is set as the target secondary pressure Pout ^* corresponding to the target secondary thrust Wout ^*. can do. As a result, the thrust (pulley pressure) can be controlled more accurately on the secondary pulley 46 side than on the primary pulley 42 side where no hydraulic pressure sensor is provided. That is, in the hydraulic control circuit 100 of this embodiment, the secondary pulley 46, which is one of the primary pulley 42 and the secondary pulley 46, is compared with the primary pulley 42, which is the other, and thrust (pulley pressure) is controlled with high accuracy. can do.

In the hydraulic control circuit 100 configured as described above, a belt slip limit thrust (hereinafter referred to as a thrust necessary for preventing belt slip with the minimum necessary thrust (necessary thrust), that is, thrust immediately before belt slip occurs). , Slip limit thrust) is set as the target thrust, the hydraulic control accuracy is relatively inferior (that is, feedback control cannot be performed based on the deviation between the detected value of the hydraulic sensor and the target value). In order to ensure this, it is necessary to add a thrust component corresponding to hydraulic pressure variation, which is a difference between the hydraulic pressure command value (primary command pressure Pintgt) and the actual hydraulic pressure (actual primary pressure Pin), to the slip limit thrust. Then, from the mutual relationship between the primary pressure Pin (primary thrust Win) and the secondary pressure Pout (secondary thrust Wout) based on the thrust ratio τ (= Wout / Win) for realizing the target shift, the primary pulley 42 side hydraulic pressure is determined. The target secondary thrust Wout ^* must also be increased corresponding to the thrust corresponding to the variation, and the fuel consumption may be deteriorated. Even without a hydraulic sensor, it is possible to correct the thrust by feedback control based on the gear ratio deviation Δγ (= γ ^* −γ) between the target gear ratio γ ^* and the actual gear ratio γ. In terms of realization, the hydraulic control accuracy is not necessarily good.

Therefore, in this embodiment, for example, on the secondary pulley 46 side with relatively good hydraulic control accuracy, the slip limit thrust on the secondary pulley 46 side is ensured, and the slip limit thrust on the primary pulley 42 side is also secured. That is, the belt torque capacity guarantee of both the pair of variable pulleys 42 and 46 is realized. On the primary pulley 42 side where the hydraulic control accuracy is relatively inferior, a target primary thrust Win ^* corresponding to the target secondary thrust Wout ^* for guaranteeing the prevention of the belt slip is set, thereby realizing a target shift. At this time, feedback control based on the gear ratio deviation Δγ is executed in order to avoid fuel consumption deterioration due to the oil pressure variation on the primary pulley 42 side.

Specifically, the transmission hydraulic pressure control unit 130 is configured to, for example, a secondary pulley side slip limit thrust Woutlmt that is a slip limit thrust on the secondary pulley 46 side and a primary pulley side slip limit that is a slip limit thrust on the primary pulley 42 side. The thrust on the secondary pulley 46 side required for shift control calculated based on the thrust Winlmt (in this embodiment, the primary pulley side slip limit thrust Winlmt (g) subjected to the lower limit guard process as described later is used). The larger one of the secondary pulley side shift control thrust Woutsh is selected as the target secondary thrust Wout ^* . The transmission hydraulic pressure control unit 130 uses, for example, a primary pulley side transmission control thrust Winsh, which is a thrust on the primary pulley 42 side necessary for transmission control calculated based on the selected target secondary thrust Wout ^* , as a target primary. Set as thrust Win ^* . The transmission hydraulic pressure control unit 130 performs target primary thrust Win ^* (that is, primary pulley side transmission control thrust Winsh) by feedback control of the primary thrust Win based on, for example, the transmission ratio deviation Δγ between the target transmission ratio γ ^* and the actual transmission ratio γ. ) Is corrected.

The gear ratio deviation Δγ may be a deviation between the target value and the actual value in the parameter corresponding to the gear ratio γ on a one-to-one basis. For example, instead of the gear ratio deviation Δγ, the deviation ΔXin (= Xin ^* −) between the target pulley position (target sheave position) Xin ^* on the primary pulley 42 side and the actual pulley position (actual sheave position) Xin (see FIG. 3). Xin), deviation ΔXout (= Xout ^* −Xout) between the target sheave position Xout ^* on the secondary pulley 46 side and the actual sheave position Xout (see FIG. 3), the target belt engagement diameter Rin ^* on the primary pulley 42 side and the actual Deviation ΔRin (= Rin ^* −Rin) from the belt engagement diameter Rin (see FIG. 3), deviation ΔRout (= from the target belt engagement diameter Rout ^* on the secondary pulley 46 side and the actual belt engagement diameter Rout (see FIG. 3) Rout ^* −Rout), a deviation ΔN _IN (= N _IN ^* −N _IN ) between the target input shaft rotational speed N _IN ^* and the actual input shaft rotational speed N _IN can be used.

The thrust necessary for the shift control is, for example, a thrust necessary for realizing the target shift, and a thrust necessary for realizing the target speed ratio γ ^* and the target speed. This speed change is, for example, the change amount dγ (= dγ / dt) of the speed ratio γ per unit time. In this embodiment, the sheave position movement amount (element (block) per element (block) of the transmission belt 48 ( dX / dNelm) (dX: sheave position change amount that is the axial displacement of the movable sheave per unit time, ie sheave position change speed (= dX / dt) [mm / ms], dNelm: per unit time Number of elements (blocks) to be engaged with the pulley [pieces / ms]). Accordingly, the target shift speed is represented by the primary target shift speed (dXin / dNelmin) and the secondary target shift speed (dXout / dNelmout).

Specifically, the primary thrust Win and the secondary thrust Wout in a steady state (a state in which the speed ratio γ is constant) are referred to as balance thrust (steady thrust) Wbl (for example, primary balance thrust Winbl and secondary balance thrust Woutbl). Is the thrust ratio τ (= Woutbl / Winbl) of the pair of variable pulleys 42 and 46. When the primary thrust Win and the secondary thrust Wout are in a steady state where a constant gear ratio γ is maintained, if a certain thrust is added to or subtracted from the thrust of one of the pair of variable pulleys 42 and 46, the steady state is lost. As a result, the speed ratio γ changes, and a speed change speed (dX / dNelm) corresponding to the magnitude of the thrust added or subtracted is generated. This added or subtracted thrust is referred to as shift difference thrust (transient thrust) ΔW (for example, primary shift difference thrust ΔWin and secondary shift difference thrust ΔWout). Therefore, when one thrust is set, the thrust required for the speed change control is the target speed ratio γ ^* corresponding to one thrust based on the thrust ratio τ for maintaining the target speed ratio γ ^* . The other balance thrust Wbl to be realized and the target shift speed when the target gear ratio γ ^* is changed (for example, the primary target shift speed (dXin / dNelmin) and the secondary target shift speed (dXout / dNelmout)) This is the sum of the shift difference thrust ΔW to be realized.

  Here, the differential thrust ΔW when the target gear shift is realized on the primary pulley 42 side, that is, the primary shift differential thrust ΔWin converted to the primary pulley side is (ΔWin> 0) in the upshift state, and the downshift state (ΔWin <0), and in a steady state with a constant gear ratio, (ΔWin = 0). The differential thrust ΔW when realizing the target shift on the secondary pulley 46 side, that is, the secondary shift differential thrust ΔWout converted to the secondary pulley side is (ΔWout <0) in the upshift state, and is in the downshift state. (ΔWout> 0), and if it is a steady state with a constant gear ratio, (ΔWout = 0).

5 and 6 are diagrams for explaining the thrust required for the shift control. These figures show, for example, the primary set when the target upshift is realized on the primary pulley 42 side when the secondary thrust Wout is set so as to realize the belt slip prevention on the secondary pulley 46 side. An example of the thrust Win is shown. In FIG. 5, before the time point t1 or after the time point t3, the target gear ratio γ ^* is in a constant steady state and ΔWin = 0, so that the primary thrust Win is only the primary balance thrust Winbl (= Wout / τ). . Since the target gear ratio γ ^* is in the upshift state from time t1 to time t3, the primary thrust Win is equal to the primary balance as shown in the thrust relationship diagram at time t2 in FIG. 5 shown in FIG. This is the sum of the thrust Winbl and the primary shift difference thrust ΔWin. The shaded portion of each thrust shown in FIG. 6 corresponds to each balance thrust Wbl for maintaining the target speed ratio γ ^* at time t2 in FIG.

In FIG. 7, when the secondary pressure sensor 78 is provided only on the secondary pulley 46 side and the primary pressure sensor is not provided on the primary pulley 42 side, the target shift and belt slip can be performed with the minimum necessary thrust. It is a block diagram which shows the control structure for making prevention compatible. Secondary-side target thrust calculating section 150 and the primary-side target force computing unit 152 shown in FIG. 7, for example, which is included in the shift hydraulic pressure control unit 130, as shown in this figure, the target gear ratio gamma ^* and An input torque T _IN of the continuously variable transmission 18 is sequentially calculated by, for example, the shift hydraulic pressure control unit 130. Specifically, the shift hydraulic pressure control unit 130 determines a post-shift target speed ratio γ ^* l that is a speed ratio γ to be achieved after the continuously variable transmission 18 is shifted. For example, the actual output shaft is calculated from the relationship (shift map) obtained and stored in advance between the output shaft rotational speed N _OUT and the target input shaft rotational speed N _IN ^* using the accelerator opening degree A _CC as shown in FIG. 8 as a parameter. A target input shaft rotational speed N _IN ^* is set based on the vehicle state indicated by the rotational speed N _OUT and the accelerator opening degree A _CC . Then, a post-shift target gear ratio γ ^* l (= N _IN ^* / N _OUT ) is calculated based on the target input shaft rotational speed N _IN ^* .

The shift map in FIG. 8 corresponds to a shift condition, and the target input shaft rotational speed N _IN ^* that sets a larger gear ratio γ is set as the output shaft rotational speed N _OUT is smaller and the accelerator opening degree A _CC is larger. It has become. This post-shift target gear ratio γ ^* l is determined within the range of the minimum gear ratio γmin (highest speed gear ratio, highest Hi) and the maximum gear ratio γmax (lowest speed gear ratio, lowest) of the continuously variable transmission 18. It is done. Then, the shift hydraulic pressure control unit 130 determines, for example, the gear ratio γ before the shift start and the target gear ratio γ ^* l after the shift from the relationship that is experimentally set in advance so as to realize a quick and smooth shift. Based on the difference, the target speed ratio γ ^* is determined as the target value of the transitional speed ratio γ during the speed change. For example, the target speed ratio γ ^* that is sequentially changed during a shift is along a smooth curve (for example, a primary delay curve or a secondary delay curve) that changes from the start of the shift toward the post-shift target speed ratio γ ^* l. Is determined as a function of elapsed time. That is, the shift hydraulic pressure control unit 130 sequentially shifts the speed ratio γ before the start of the shift from the speed ratio γ before the start of the shift to the target speed ratio γ ^* 1 after the shift during the shift of the continuously variable transmission 18. The target gear ratio γ ^* is changed.

For example, the transmission hydraulic pressure control unit 130 has a torque ratio t of the torque converter 14 to the engine torque T _E (= turbine torque T _T that is the output torque of the torque converter 14 / pump torque T _P that is the input torque of the torque converter 14). As a torque multiplied by (= T _E × t), the input torque T _IN of the continuously variable transmission 18 is calculated. For example experimentally determined in advance is storing the intake air quantity Q _AIR (or throttle opening theta _TH like equivalent) engine rotational speed N _E and engine torque T _E as a parameter as a required load for the engine 12 From the relationship shown in FIG. 9 (map, engine torque characteristic diagram), the engine torque T _E is calculated as the estimated engine torque T _E es based on the intake air amount Q _AIR and the engine rotational speed N _E. Alternatively, the engine torque T _E may be, for example, the actual output torque (actual engine torque) T _{E of the} engine 12 detected by a torque sensor or the like. The torque ratio t of the torque converter 14 is the speed ratio e of the torque converter 14 (= the turbine rotation speed N _T that is the output rotation speed of the torque converter 14 / the pump rotation speed N _P that is the input rotation speed of the torque converter 14). 10 is a function of the engine speed N _E )). For example, the relationship between the speed ratio e, the torque ratio t, the efficiency η, and the capacity coefficient C obtained and stored in advance as shown in FIG. Based on the actual speed ratio e, the shift hydraulic pressure control unit 130 calculates the map from a predetermined operating characteristic diagram of the torque converter 14). Estimated engine torque T _E es is what is calculated to represent the actual engine torque T _E itself, in particular except for distinguishing between actual engine torque T _E, the estimated engine torque T _E es actual engine torque T _E Shall be handled as Therefore, the estimated engine torque T _E es includes the actual engine torque T _E.

In the block B1 and the block B2 in FIG. 7, the slip limit thrust calculation unit 132 calculates the slip limit thrust Wlmt based on, for example, the actual speed ratio γ and the input torque T _IN of the continuously variable transmission 18. Specifically, for example, from the following formula (1) and the following formula (2), the input torque T _IN of the continuously variable transmission 18 as the input torque of the primary pulley 42 and the no-load as the input torque of the secondary pulley 46 are described. The output torque T _OUT of the step transmission 18, the sheave angle α of the variable pulleys 42, 46, the predetermined element-pulley friction coefficient μin on the primary pulley 42 side, the predetermined element-pulley friction on the secondary pulley 46 side The belt engagement diameter Rin on the primary pulley 42 side calculated uniquely from the coefficient μout and the actual transmission ratio γ, and the belt engagement diameter Rout on the secondary pulley 46 side calculated uniquely from the actual transmission ratio γ (hereinafter, FIG. 3), the secondary pulley side slip limit thrust Woutlmt and the primary pulley side slip limit thrust Winlmt are respectively calculated. Here, T _OUT = γ × T _IN = (Rout / Rin) × T _IN . However, in the block B2, the slip limit thrust calculation unit 132 calculates the primary pulley side slip limit thrust Winlmt (g) subjected to the lower limit guard process based on the primary pulley side slip limit thrust Winlmt, as will be described later. To do.

Woutlmt = (T _OUT × cos α) / (2 × μout × Rout)
= (T _IN × cos α) / (2 × μout × Rin) (1)
Winlmt = (T _IN × cos α) / (2 × μin × Rin) (2)

In block B3 and block B6 of FIG. 7, the steady thrust calculation unit 134 converts the secondary balance thrust Woutbl and the target secondary thrust Wout ^* corresponding to the primary pulley side slip limit thrust Winlmt (g) subjected to the lower limit guard process, for example. Corresponding primary balance thrust Winbl is calculated respectively. Specifically, the reciprocal SFin ⁻¹ (= Winlmt (g) / Win) of the primary-side safety factor SFin (= Win / Winlmt (g)) and the primary pulley 42 side corresponding to the target speed ratio γ ^* as a parameter. For example, a target gear ratio γ that is sequentially calculated from a relationship (thrust ratio map) as shown in FIG. 11, for example, which is experimentally obtained and stored in advance with the thrust ratio τin when the thrust on the secondary pulley 46 side is calculated. ^The thrust ratio τin is calculated based on ^* and the reciprocal SFin ⁻¹ of the primary safety factor. Then, the steady thrust calculation unit 134 calculates the secondary balance thrust Woutbl based on the primary pulley side slip limit thrust Winlmt (g) and the thrust ratio τin subjected to the lower limit guard process from the following equation (3). The steady thrust calculation unit 134 uses the target gear ratio γ ^* as a parameter and the reciprocal SFout ⁻¹ (= Woutlmt / Wout) of the secondary-side safety factor SFout (= Wout / Woutlmt) and the primary pulley corresponding to the secondary pulley 46 side. For example, the target gear ratio γ ^* and the secondary calculated sequentially from the relationship (thrust ratio map) as shown in FIG. 12, for example, obtained experimentally and stored in advance with the thrust ratio τout when calculating the 42 side thrust. The thrust ratio τout is calculated based on the reciprocal SFout ⁻¹ of the side safety factor. Then, the steady thrust calculating unit 134 calculates the primary balance thrust Winbl based on the target secondary thrust Wout ^* and the thrust ratio τout from the following equation (4). Since the input torque T _IN and the output torque T _OUT become negative values when driven, the reciprocals SFin ⁻¹ and SFout ^{−1 of the} above safety factors also become negative values when driven. These reciprocal numbers SFin ⁻¹ and SFout ⁻¹ may be calculated sequentially. However, if a predetermined value (for example, about 1 to 1.5) is set for each of the safety factors SFin and SFout, the reciprocal number may be set. good.

Woutbl = Winlmt (g) × τin (3)
Winbl = Wout ^* / τout (4)

In the block B4 and the block B7 in FIG. 7, the differential thrust calculation unit 136, for example, a secondary shift differential thrust ΔWout as a differential thrust ΔW converted on the secondary pulley side when the target shift is realized on the secondary pulley 46 side, for example. A primary shift difference thrust ΔWin is calculated as a differential pulley ΔW converted to the primary pulley when the target shift is realized on the primary pulley 42 side. For example, the target input shaft rotational speed is determined based on the vehicle state indicated by the actual vehicle speed V (output shaft rotational speed N _OUT ) and the accelerator opening degree A _CC from a predetermined relationship (for example, a shift map as shown in FIG. 8). Set N _IN ^* . Based on the target input shaft rotational speed N _IN ^* , a post-shift target speed ratio γ ^* l (= N _IN ^* / N _OUT ) is calculated, and the post-shift target speed ratio γ ^* l is determined from a predetermined relationship. The primary target shift speed (dXin / dNelmin) and the secondary target shift speed (dXout / dNelmout) are calculated. Based on the primary target shift speed (dXin / dNelmin) and the secondary target shift speed (dXout / dNelmout) sequentially calculated as described above, the primary shift difference thrust ΔWin from a predetermined relationship (difference thrust map), Secondary shift difference thrust ΔWout is calculated.

  As described above, the calculations in the blocks B3 and B4 in FIG. 7 use physical characteristic diagrams that are obtained experimentally and set in advance, such as a thrust ratio map and a differential thrust map. Therefore, there are variations in the physical characteristics in the calculation results of the secondary balance thrust Woutbl and the secondary shift difference thrust ΔWout due to individual differences in the hydraulic control circuit 100 and the like. Therefore, when considering such a variation in physical characteristics, the slip limit thrust calculation unit 132, for example, the thrust on the secondary pulley 46 side based on the primary pulley side slip limit thrust Winlmt (g) subjected to the lower limit guard process, for example. Prior to calculation of the thrust on the secondary pulley 46 side, the predetermined thrust (control margin) Wmgn corresponding to the variation with respect to the physical characteristics related to the calculation of (secondary balance thrust Woutbl and secondary shift difference thrust ΔWout) Add to the slip limit thrust Winlmt (g). Therefore, when considering variation with respect to the physical characteristics, in the block B3, the steady thrust calculation unit 134 adds the control margin Wmgn from the following equation (3) ′ instead of the equation (3), for example. The secondary balance thrust Woutbl is calculated based on the primary pulley side slip limit thrust Winlmt (g) and the thrust ratio τin.

  Woutbl = (Winlmt (g) + Wmgn) × τin (3) ′

The control margin Wmgn is, for example, a constant value (design value) obtained and set experimentally in advance. However, the control margin Wmgn is more variable in the transient state (during gear shift) than the steady state (speed ratio constant state). Since a large number of ratio map and differential thrust map physical characteristic diagrams) are used, a large value is set. Variations in the physical characteristics related to the calculation include, for example, variations in the control hydraulic pressures P _SLP and P _SLS with respect to the control currents to the linear solenoid valves SLP and SLS, variations in drive circuits that output the control currents, and control hydraulic pressures P _SLP. This is different from the deviation of the actual oil pressure with respect to the oil pressure command value of the pulley pressure, such as the fluctuation of the actual pulley pressure Pin and Pout with respect to P _SLS (the oil pressure fluctuation and the oil pressure control fluctuation). Although the hydraulic pressure variation is a relatively large value depending on the unit (hard unit such as the hydraulic control circuit 100), the variation with respect to the physical characteristics related to the calculation is an extremely small value compared to the hydraulic pressure variation. . Therefore, adding the control margin Wmgn to the primary pulley side slip limit thrust Winlmt (g) means that the target pulley pressure can be obtained no matter how much the actual pulley pressure varies with respect to the pulley pressure hydraulic pressure command value. Compared with adding a control variation to the command value, deterioration of fuel consumption is suppressed. Since the calculation in the blocks B6 and B7 is based on the target secondary thrust Wout ^* , the control margin Wmgn is not added here to the target secondary thrust Wout ^* prior to the calculation.

The transmission hydraulic pressure control unit 130, for example, as a secondary thrust necessary to prevent belt slippage on the primary pulley 42 side, is obtained by adding a secondary shift difference thrust ΔWout to a secondary balance thrust Woutbl (secondary pulley side shift control thrust Woutsh (= Woutbl + ΔWout) is calculated. In block B5 of FIG. 7, the transmission hydraulic pressure control unit 130 selects the larger one of the secondary pulley side slip limit thrust Woutlmt and the secondary pulley side shift control thrust Woutsh as the target secondary thrust Wout ^* .

The shift hydraulic pressure control unit 130 calculates a primary pulley side shift control thrust Winsh (= Winbl + ΔWin) by adding, for example, a primary shift difference thrust ΔWin to the primary balance thrust Winbl. In block B8 of FIG. 7, the feedback control amount calculation unit 138 uses the feedback control expression obtained and set in advance as shown in the following equation (5), for example, to set the actual speed ratio γ to the target speed ratio γ ^*. Is calculated as a feedback control amount (feedback control correction amount) Winfb. In this equation (5), Δγ is a gear ratio deviation (= γ ^* −γ) between the target gear ratio γ ^* and the actual gear ratio γ, KP is a predetermined proportionality constant, KI is a predetermined integral constant, and KD is a predetermined speed. Differential constant. Then, the transmission hydraulic pressure control unit 130 sets, for example, a value (= Winsh + Winfb) corrected by feedback control based on the transmission ratio deviation Δγ for the primary pulley side transmission control thrust Winsh as the target primary thrust Win ^* . In this way, the blocks B1 to B5 function as the secondary target thrust calculation unit 152 that sets the target secondary thrust Wout ^* . The blocks B6 to B8 function as a primary target thrust calculation unit 154 that sets a target primary thrust Win ^* .

  Winfb = KP × Δγ + KI × (∫Δγdt) + KD × (dΔγ / dt) (5)

In block B9 and block B10 in FIG. 7, the shift hydraulic pressure control unit 130 converts, for example, a target thrust into a target pulley pressure. Specifically, the transmission hydraulic pressure control unit 130 sets the target secondary thrust Wout ^* and the target primary thrust Win ^* to the target secondary pressure Pout ^* (=) based on the pressure receiving areas Ain and Aout of the hydraulic cylinders 46c and 42c. Wout ^* / Aout) and target primary pressure Pin ^* (= Win ^* / Ain). The shift hydraulic pressure control unit 130 sets the target secondary pressure Pout ^* and the target primary pressure Pin ^* as the secondary command pressure Pouttgt and the primary command pressure Pintgt.

The transmission hydraulic pressure control unit 130 outputs the primary command pressure Pintgt and the secondary command pressure Pouttgt to the hydraulic control circuit 100 as the hydraulic control command signal S _CVT so that, for example, the target primary pressure Pin ^* and the target secondary pressure Pout ^* are obtained. To do. In accordance with the hydraulic control command signal S _CVT , the hydraulic control circuit 100 operates the linear solenoid valve SLP to adjust the primary pressure Pin, and operates the linear solenoid valve SLS to adjust the secondary pressure Pout.

For example, in order to compensate for the hydraulic pressure variation on the secondary pulley 46 side (variation in hydraulic control), the transmission hydraulic pressure control unit 130 detects the secondary pressure Pout detected by the secondary pressure sensor 78 as a target secondary pressure Pout ^*. The secondary command pressure Pouttgt is corrected by feedback control based on a deviation ΔPout (= Pout ^* −Pout detection value) between the detected value of the secondary pressure Pout and the target secondary pressure Pout ^* . In the hydraulic control circuit 100 of the present embodiment, since the hydraulic sensor is not provided on the primary pulley 42 side, the primary control is performed by feedback control on the secondary pulley 46 side based on the deviation between the detected value of the pulley pressure and the actual value. The command pressure Pintgt cannot be corrected. However, in this embodiment, for example, a value (= Winsh + Winfb) corrected by feedback control so that the actual gear ratio γ matches the target gear ratio γ ^* in the block B8 is set as the target primary thrust Win ^* . The variation in hydraulic pressure on the primary pulley 42 side can be compensated.

As described above, in the feedback control in which the actual speed ratio γ in the continuously variable transmission 18 follows the target speed ratio γ ^* , the hydraulic sensor detection value deviation determination unit 144 and the primary pulley hydraulic pressure deviation determination unit shown in FIG. 146, the gear ratio deviation determination unit 148 and the abnormal part determination unit 150 determine an abnormality related to the hydraulic control of the continuously variable transmission 18. For example, the secondary pressure sensor 78 included in the hydraulic pressure control circuit 100 when a deviation greater than a specified value occurs between the detection value (hydraulic sensor value) of the secondary pressure sensor 78 and the target secondary pressure Pout ^*. It is determined whether or not an abnormality has occurred in the device itself, or an abnormality has occurred in the secondary pressure Pout (the desired secondary pressure Pout has not been output, or there is an abnormality in the configuration that generates the secondary pressure Pout). To do. Hereinafter, these control functions will be described.

The hydraulic sensor detection value deviation determination unit 144 determines whether or not a deviation greater than a specified value has occurred between the secondary pressure Pout (actual value) detected by the secondary pressure sensor 78 and the target secondary pressure Pout ^*. To do. For example, whether or not the secondary pressure Pout detected by the secondary pressure sensor 78 is greater than or equal to a predetermined threshold value α with respect to the target secondary pressure Pout ^* , that is, whether or not the following equation (6) holds: If the determination is positive and the determination is affirmative, it is determined that a divergence greater than the specified amount has occurred with the target secondary pressure Pout ^* . When the absolute value of the difference between the secondary pressure Pout detected by the secondary pressure sensor 78 and the target secondary pressure Pout ^* is determined to be greater than or equal to a predetermined threshold value α, the determination is affirmative. It may be determined that a deviation more than a specified amount has occurred between the target secondary pressure Pout ^* . That is, it is determined whether or not the following equation (7) is satisfied, and if the determination is affirmative, it may be determined that a deviation greater than a specified value has occurred with the target secondary pressure Pout ^*. Good.

Pout ≧ Pout ^* + α (6)
| Pout−Pout ^* | ≧ α (7)

The primary pulley hydraulic pressure estimation unit 142 preferably has a divergence greater than or equal to a specified value between the secondary pressure Pout and the target secondary pressure Pout ^* detected by the secondary pressure sensor 78 by the hydraulic pressure sensor detection value deviation determination unit 144. When it is determined that the pressure has occurred, the primary pressure Pin supplied to the primary hydraulic cylinder 42c is estimated based on the secondary pressure Pout detected by the secondary pressure sensor 78. The determination by the primary pulley hydraulic pressure divergence determination unit 146 and the determination by the abnormal point determination unit 150, which will be described later, are preferably determined by the hydraulic sensor detection value divergence determination unit 144 and the primary pulley hydraulic pressure estimator 142. When the primary pressure Pin is estimated based on the secondary pressure Pout, the process is executed corresponding to the estimated primary pressure Pin.

The primary pulley hydraulic pressure deviation determination unit 146 compares the estimated value Pines of the primary pressure Pin estimated by the primary pulley hydraulic pressure estimation unit 142 with a command value, that is, the target primary pressure Pin ^* , and determines the deviation. The primary pulley hydraulic pressure deviation determining unit 146 preferably determines whether or not the deviation of the estimated value Pines of the primary pressure Pin from the command value Pin ^* is within a specified range. For example, it is determined whether or not the absolute value of the difference between the estimated value Pines and the command value Pin ^* is less than a predetermined threshold dP, that is, whether or not the following equation (8) holds: When is affirmed, it is determined that the deviation is within the specified range.

| Pines-Pin ^* | <dP (8)

The primary pulley hydraulic pressure divergence determining unit 146 preferably has a predetermined threshold value for a target primary pressure Pin ^{* in} which the estimated value Pines of the primary pressure Pin estimated by the primary pulley hydraulic pressure estimating unit 142 is a command value. It is determined whether it is greater than β1. That is, it is determined whether or not the following equation (9) is satisfied. In other words, it is determined whether or not the estimated value Pines of the primary pressure Pin deviates by a predetermined value β1 or more on the larger side with respect to the target primary pressure Pin ^* .

Pines−Pin ^* ≧ β1 (9)

The gear ratio deviation determining unit 148 compares the actual gear ratio γ of the continuously variable transmission 18 calculated by the actual gear ratio calculating unit 140 with the target gear ratio γ ^* to determine the deviation. Preferably, the gear ratio deviation determining unit 148 preferably determines whether or not the absolute value of the difference between the actual gear ratio γ and the target gear ratio γ ^* is less than a predetermined threshold value dγ, that is, the following (10) It is determined whether or not the equation is established, and if the determination is affirmative, it is determined that the deviation is within the specified range.

| Γ−γ ^* | <dγ (10)

Preferably, the gear ratio divergence determining unit 148 preferably has a threshold value β2 that is obtained by setting the actual gear ratio γ of the continuously variable transmission 18 calculated by the actual gear ratio calculating unit 140 to a target gear ratio γ ^* . It is determined whether or not it is larger. That is, it is determined whether or not the following equation (11) is satisfied. Preferably β2 is zero. That is, the gear ratio deviation determining unit 148 preferably determines whether or not the actual gear ratio γ of the continuously variable transmission 18 calculated by the actual gear ratio calculating unit 140 is equal to or greater than a target gear ratio γ ^* . In other words, it is determined whether or not the actual speed ratio γ deviates to the larger side with respect to the target speed ratio γ ^* .

γ−γ ^* ≧ β2 (11)

The abnormal point determination unit 150 is a case where the primary pulley hydraulic pressure estimation unit 142 estimates the primary pressure Pin based on the secondary pressure Pout, and the hydraulic sensor detection value deviation determination unit 144 measures the secondary pressure Pout. When it is determined that a deviation greater than the specified value has occurred between the value and the target secondary pressure Pout ^* , the comparison result by the primary pulley hydraulic pressure deviation determination unit 146 and the comparison result by the gear ratio deviation determination unit 148 Based on the above, it is determined which of the secondary pressure sensor 78 and the secondary pressure Pout is abnormal. Here, as a case where an abnormality occurs in the secondary pressure sensor 78, an on-failure (high-pressure side abnormality), an off-failure (low-pressure side abnormality), or the like due to a wiring short-circuit or the like can be considered. When an abnormality occurs in the secondary pressure Pout, some failure occurs in the linear solenoid valve SLS, the secondary pressure control valve 112, or the like, which is a configuration for adjusting the secondary pressure Pout provided in the hydraulic control circuit 100. The case where it did is considered.

The abnormal point determination unit 150 is preferably a case where the primary pulley hydraulic pressure estimation unit 142 estimates the primary pressure Pin based on the secondary pressure Pout, and the primary pulley hydraulic pressure deviation determination unit 146 determines the primary pressure. It is determined that the estimated value Pines is deviating to the larger side with respect to the target primary pressure Pin ^* , and the deviation of the actual gear ratio γ from the target gear ratio γ ^* is within a specified range by the gear ratio deviation judging unit 148. Is determined, it is determined that an abnormality has occurred in the secondary pressure sensor 78. That is, preferably, the estimated value Pines of the primary pressure Pin is larger than a predetermined threshold value β1 with respect to the target primary pressure Pin ^* which is a command value, and the actual speed ratio γ and the target speed ratio γ ^* If the absolute value of the difference is less than a predetermined threshold value dγ, it is determined that an abnormality has occurred in the primary pressure sensor 78. That is, when the equation (9) is established and the equation (10) is established, it is determined that an abnormality has occurred in the primary pressure sensor 78.

The abnormal point determination unit 150 is preferably a case where the primary pulley hydraulic pressure estimation unit 142 estimates the primary pressure Pin based on the secondary pressure Pout, and the primary pulley hydraulic pressure deviation determination unit 146 determines the primary pressure. It is determined that the deviation of the estimated value Pines from the target primary pressure Pin ^* is within a specified range, and the gear ratio deviation judgment unit 148 causes the actual gear ratio γ to deviate to the larger side with respect to the target gear ratio γ ^* . When it is determined that there is an abnormality, it is determined that an abnormality has occurred in the secondary pressure Pout. That is, preferably, the absolute value of the difference between the estimated value Pines of the primary pressure Pin and the target primary pressure Pin ^* which is the command value is less than a predetermined threshold dP, and the actual speed ratio γ is the target. When it is greater than the gear ratio γ ^* , it is determined that an abnormality has occurred in the secondary pressure Pout. That is, when the equation (8) is satisfied and the equation (11) is satisfied, it is determined that an abnormality has occurred in the secondary pressure Pout.

FIG. 13 shows each relational value when an abnormality occurs in which the secondary pressure Pout supplied to the secondary pulley 46 actually increases in the feedback control of the speed ratio γ in the continuously variable transmission 18 by the electronic control unit 50. It is a time chart which shows a time-dependent change. In the time chart of FIG. 13, the target secondary pressure Pout ^* and the target speed ratio γ ^* are indicated by broken lines, and the value obtained by adding the threshold α to the target secondary pressure Pout ^* is indicated by a two-dot chain line. First, at time t1, an abnormality that the secondary pressure Pout supplied to the secondary pulley 46 actually increases occurs. At time t2, the secondary pressure Pout detection value detected by the secondary pressure sensor 78 is indicated by a two-dot chain line. It exceeds the value obtained by adding the threshold value α to the target secondary pressure Pout ^* indicated by. Since the secondary pressure sensor 78 is operating normally, the detected value (hydraulic sensor value) and the secondary pressure Pout actual pressure show substantially the same change. The speed ratio γ in the continuously variable transmission 18 deviates to the larger side as compared with the target speed ratio γ _* , and the difference is equal to or greater than β2. Here, considering the primary pressure estimated value Pines at the time point t3, the primary actual pressure is in a predetermined range centered on the primary pressure estimated value Pines, and the difference between the target primary pressure Pin ^* and the estimated value Pines is small. I understand that. On the other hand, the actual speed ratio gamma becomes the target speed ratio gamma ^* above, is deviated to a larger side with respect to the target speed ratio gamma ^*. As described above, when no abnormality has occurred in the secondary pressure sensor 78 and an abnormality has occurred in which the secondary pressure Pout supplied to the secondary pulley 46 actually increases, the estimated value Pines of the primary pressure Pin Since the deviation from the target primary pressure Pin ^* is relatively small and the actual speed ratio γ is equal to or greater than the target speed ratio γ ^* , an abnormality occurs in the secondary pressure Pout when such a condition is satisfied. Can be determined.

FIG. 14 shows various relationships in the case where an abnormality (on-fail) in which the detected value of the secondary pressure sensor 78 is on the high pressure side occurs in the feedback control of the speed ratio γ in the continuously variable transmission 18 by the electronic control unit 50. It is a time chart which shows a time-dependent change of a value. In the time chart of FIG. 14, the actually measured value of the secondary pressure Pout (the value detected by the secondary pressure sensor 78, the hydraulic pressure sensor value) is indicated by a one-dot chain line, the target gear ratio γ ^* is indicated by a broken line, and the threshold value α is set for the target secondary pressure Pout ^*. The added values are indicated by two-dot chain lines. First, at time t1, an abnormality (on-fail) is detected in which the secondary pressure sensor 78 detects a value higher than the original pressure, and secondary pressure Pout detected by the secondary pressure sensor 78 at time t2. The value exceeds the value obtained by adding the threshold value α to the target secondary pressure Pout ^* indicated by the two-dot chain line. Here, as indicated by a broken line, the primary pressure Pin temporarily rises immediately after the time point t2 and the speed ratio γ decreases accordingly. However, the feedback control of the primary pressure Pin follows the target value. It is done. Here, considering the primary pressure estimated value Pines at time t3, the predetermined range centered on the primary pressure estimated value Pines is larger than the primary actual pressure by β1 or more. That is, the estimated value Pines deviates more than the threshold value β1 toward the larger side than the target primary pressure Pin ^* . On the other hand, the actual speed ratio γ substantially matches the target speed ratio γ ^* , and the deviation is within a specified range. As described above, when there is an abnormality in which the detection value of the secondary pressure sensor 78 is shifted to the high pressure side, and there is no abnormality in the secondary pressure Pout supplied to the secondary pulley 46, the primary pressure Pin The estimated value Pines is greater than a predetermined threshold β1 with respect to the target primary pressure Pin ^* , and the deviation of the actual speed ratio γ from the target speed ratio γ ^* is within a specified range. If it is established, it can be determined that an abnormality such as an on-fail that the detection value of the secondary pressure sensor 78 is shifted to the high pressure side has occurred.

FIG. 15 shows various relationships when an abnormality (off-fail) in which the detected value of the secondary pressure sensor 78 is on the low pressure side occurs in the feedback control of the speed ratio γ in the continuously variable transmission 18 by the electronic control unit 50. It is a time chart which shows a time-dependent change of a value. In the time chart of FIG. 15, the actually measured value of the secondary pressure Pout (the detected value by the secondary pressure sensor 78, the hydraulic pressure sensor value) is indicated by a one-dot chain line. First, at time t1, an abnormality (off-fail) occurs in which the secondary pressure sensor 78 detects a value lower than the original pressure, and detection of the secondary pressure Pout detected by the secondary pressure sensor 78 at time t2. The value is smaller than the value obtained by subtracting the threshold value α from the target secondary pressure Pout ^* substantially equal to the Pout actual pressure. Here, considering the primary pressure estimated value Pines at time t3, the predetermined range centered on the primary pressure estimated value Pines is smaller than the primary actual pressure by β1 or more. That is, the estimated value Pines deviates more than the threshold value β1 toward the smaller side than the target primary pressure Pin ^* . On the other hand, the actual speed ratio γ substantially matches the target speed ratio γ ^* , and the deviation is within a specified range. As described above, when there is an abnormality in which the detection value of the secondary pressure sensor 78 is shifted to the low pressure side, and there is no abnormality in the secondary pressure Pout supplied to the secondary pulley 46, the primary pressure Pin The estimated value Pines is smaller than the target primary pressure Pin ^* by a predetermined threshold value β1 and the deviation of the actual speed ratio γ from the target speed ratio γ ^* is within a specified range. If it is established, it can be determined that an abnormality such as an off-failure in which the detection value of the secondary pressure sensor 78 is shifted to the low pressure side has occurred.

  FIG. 16 is a flowchart for explaining a main part of the failure location determination control by the electronic control unit 50, which is repeatedly executed at a predetermined cycle.

First, in step (hereinafter, step is omitted) S1, is the secondary pressure Pout (hydraulic sensor value) detected by the secondary pressure sensor 78 equal to or greater than a value obtained by adding a predetermined value α to the target secondary pressure Pout ^* ? It is determined whether or not. If the determination at S1 is negative, the routine is terminated accordingly. If the determination at S1 is affirmative, the secondary pressure sensor 78 detects the determination at S2 from a predetermined relationship. The estimated value Pines of the primary pressure Pin supplied to the primary pulley 42 is calculated based on the secondary pressure Pout, the actual transmission ratio γ of the continuously variable transmission 18, the input torque (turbine torque) T _{IN and the} like. The

Next, in S3, the difference (γ−γ ^* ) between the actual speed ratio γ and the target speed ratio γ ^* of the continuously variable transmission 18 is equal to or greater than a predetermined threshold value β2 (preferably β2 = 0). It is determined whether or not. If the determination in S3 is negative, the processing from S6 is executed. If the determination in S3 is affirmative, in S4, the estimated value Pines of the primary pressure Pin calculated in S2 is determined. It is determined whether or not the absolute value (| Pines−Pin ^* |) of the difference from the target primary pressure Pin ^* is less than a predetermined threshold value dP. If the determination in S4 is negative, the routine is terminated accordingly. If the determination in S4 is affirmative, the secondary pressure (secondary sheave pressure) supplied to the secondary pulley 46 is determined in S5. ) After determining that an abnormality has occurred in Pout, this routine is terminated.

In S6, whether or not the absolute value (| γ−γ ^* |) of the difference between the actual transmission gear ratio γ and the target transmission gear ratio γ ^* of the continuously variable transmission 18 is less than a predetermined threshold value dγ. To be judged. If the determination in S6 is negative, the routine is terminated accordingly. If the determination in S6 is affirmative, in S7, the estimated value Pines of the primary pressure Pin calculated in S2 is determined. It is determined whether or not the difference (Pines−Pin ^* ) from the target primary pressure Pin ^* is equal to or greater than a predetermined threshold value β1. If the determination at S7 is negative, the routine is terminated accordingly. If the determination at S7 is affirmative, it is determined at S8 that an abnormality has occurred in the secondary pressure sensor 78. Then, this routine is terminated. In the above control, S1 is the operation of the hydraulic sensor detection value deviation determination unit 144, S4 and S7 are the operation of the primary pulley hydraulic pressure deviation determination unit 146, and S3 and S6 are the operations of the gear ratio deviation determination unit 148. , S5 and S8 correspond to the operation of the abnormal point determination unit 150, respectively.

As described above, according to this embodiment, the continuously variable transmission includes the secondary pressure sensor 78 that is a hydraulic pressure sensor that detects the second hydraulic pressure that is supplied to the secondary pulley 46 that is the output-side variable pulley, that is, the secondary pressure Pout. In feedback control for causing the actual speed ratio γ at 18 to follow the target speed ratio γ ^* , the first hydraulic pressure supplied to the primary pulley 42 that is the input-side variable pulley based on the secondary pressure Pout detected by the secondary pressure sensor 78. That is, the secondary pressure sensor is estimated based on the comparison result of the estimated value Pines of the primary pressure Pin with the command value Pin ^* and the comparison result of the actual speed ratio γ with respect to the target speed ratio γ ^* . 78 or the secondary pressure Pout is judged, and a new configuration is added. Without, by estimating the primary pressure Pin based on existing information, abnormality in any of the secondary pressure sensor 78 and the secondary pressure Pout it can be determined whether they occur. That is, it is possible to provide the electronic control device 50 including the hydraulic control device of the continuously variable transmission 18 that easily determines the failure location without adding a new configuration.

When the estimated value Pines of the primary pressure Pin is greater than a predetermined threshold value β1 with respect to the command value Pin ^* and the deviation of the actual speed ratio γ from the target speed ratio γ ^* is within a specified range, Since it is determined that an abnormality has occurred in the primary pressure sensor 78, the occurrence of an abnormality in the primary pressure sensor 78 can be easily determined without adding a new configuration.

When the deviation of the estimated value Pines of the primary pressure Pin from the command value Pin ^* is within a specified range and the actual speed ratio γ is deviated to the larger side with respect to the target speed ratio γ ^* , Since it is determined that an abnormality has occurred in the secondary pressure Pout, it is possible to easily determine the occurrence of the abnormality related to the secondary pressure Pout without adding a new configuration.

  The preferred embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. Is.

  18: belt type continuously variable transmission for vehicle, 42: primary pulley (input side variable pulley), 46: secondary pulley (output side variable pulley), 48: transmission belt, 50: electronic control device, 78: secondary pressure sensor ( Hydraulic sensor)

Claims (3)

In a belt-type continuously variable transmission having an input-side variable pulley and an output-side variable pulley whose effective diameter is variable, and a transmission belt wound between the pair of variable pulleys, the input-side variable pulley A hydraulic control device for a vehicle belt-type continuously variable transmission for controlling a first hydraulic pressure supplied and a second hydraulic pressure supplied to the output-side variable pulley,
A hydraulic sensor for detecting a second hydraulic pressure supplied to the output-side variable pulley;
In feedback control for causing the actual speed ratio in the belt type continuously variable transmission to follow the target speed ratio, the first hydraulic pressure supplied to the input-side variable pulley is estimated based on the second hydraulic pressure detected by the hydraulic sensor. Based on the comparison result of the estimated value of the first hydraulic pressure with respect to the command value and the comparison result of the actual gear ratio with respect to the target gear ratio, an abnormality has occurred in either the hydraulic pressure sensor or the second hydraulic pressure. A hydraulic control device for a belt type continuously variable transmission for a vehicle, characterized in that   When the estimated value of the first hydraulic pressure is greater than a predetermined threshold value with respect to the command value and the deviation of the actual gear ratio from the target gear ratio is within a specified range, an abnormality occurs in the hydraulic sensor. 2. The hydraulic control device for a belt-type continuously variable transmission for a vehicle according to claim 1, wherein the hydraulic control device is for determining that the vehicle is running.   When the deviation of the estimated value of the first hydraulic pressure from the command value is within a specified range and the actual gear ratio deviates to the larger side with respect to the target gear ratio, there is an abnormality in the second hydraulic pressure. 2. The hydraulic control device for a belt-type continuously variable transmission for a vehicle according to claim 1, wherein the hydraulic control device determines that it has occurred.

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