JP2009270690A - Oil pressure control device for vehicular continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil pressure control device capable of properly controlling oil pressures of plural places while suppressing cost increase in a belt type continuously variable transmission. <P>SOLUTION: In a gear ratio control means 150, during regular times, gear ratio control of the continuously variable transmission 18 is carried out while detecting a primary actual oil pressure Pinp (=Pin) by an oil pressure sensor 132. Furthermore, when a fail safe valve 130 in a second communication state (a FAIL side) in a predetermined vehicle state wherein the gear ratio control is not carried out, an oil pressure learning means 174 learns a relationship between a secondary oil pressure Pd detected by the oil pressure sensor 132 and a control command value I<SB>SLS</SB>determining it, and on the basis of the learned relationship, a secondary oil pressure map stored by a belt clamping force control means 152 is updated. Accordingly, by providing one oil pressure sensor 132 without requiring two oil pressure sensors, both oil pressures of the primary oil pressure Pin and the secondary oil pressure Pd can be properly controlled. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hydraulic control device for a belt-type continuously variable transmission for a vehicle, and relates to a technique for regulating hydraulic pressure.

  In a vehicle having a continuously variable transmission having a driving pulley, a driven pulley, and a belt wound around both pulleys on a power transmission path between an engine that is a driving power source and driving wheels, the drive The side pulley is provided with a driving hydraulic actuator for changing the groove width, and the driven pulley is provided with a driven hydraulic actuator for changing the groove width. 2. Description of the Related Art Conventionally, a hydraulic control device for a vehicle continuously variable transmission that shifts the continuously variable transmission by changing a winding diameter (effective diameter) of the belt is known. For example, this is the hydraulic control device for a continuously variable transmission for a vehicle disclosed in Patent Document 1. According to FIG. 6 of Patent Document 1, the hydraulic control device for the continuously variable transmission for a vehicle includes a hydraulic pressure sensor, a first port to which a driving side hydraulic pressure of the driving side hydraulic actuator is applied, and the driven side hydraulic pressure. An electromagnetic switching valve having a second port to which the driven hydraulic pressure of the actuator is applied and a third port connected to the hydraulic pressure sensor is provided. When the electromagnetic switching valve is not excited, the second port and the third port are communicated and the driven hydraulic pressure is detected by the hydraulic sensor. On the other hand, when the electromagnetic switching valve is excited, the first port And the third port are in communication with each other, and the drive side hydraulic pressure is detected by the hydraulic pressure sensor. In such a configuration, when the hydraulic control device learns the relationship between the drive side hydraulic pressure and its control command value, the hydraulic control device excites the electromagnetic switching valve and the hydraulic sensor detects the drive side. After the hydraulic pressure can be detected, the control command value is changed, and the relationship between the control command value and the drive side hydraulic pressure is stored and learned.

JP 2006-316819 A JP 2005-163934 A

  The hydraulic control device for a continuously variable transmission for a vehicle disclosed in Patent Document 1 has a configuration in which both the driving-side hydraulic pressure and the driven-side hydraulic pressure can be detected by a single hydraulic pressure sensor. Yes. However, the electromagnetic switching valve is provided only for detecting both the driving side hydraulic pressure and the driven side hydraulic pressure with one hydraulic pressure sensor, and further, the relationship between the driving hydraulic pressure and the control command value thereof. Is not frequently performed, and is expensive in view of the purpose of use of the electromagnetic switching valve that rarely functions. In other words, since the third port corresponding to the output port of the electromagnetic switching valve is connected only to the hydraulic sensor, the electromagnetic switching valve cannot be provided with other functions. For example, if not only the oil pressure sensor but also the driven hydraulic actuator are connected to the third port of the electromagnetic switching valve, a pressure adjusting valve for adjusting the driven oil pressure or a pressure adjusting valve for adjusting the drive oil pressure. A function of applying the driven hydraulic pressure, which is the hydraulic pressure of another hydraulic circuit, to the driving hydraulic actuator or a function of applying the driving hydraulic pressure to the driven hydraulic actuator when the pressure valve breaks down, In spite of the fact that the electromagnetic switching valve can be used in combination, the hydraulic control device disclosed in Patent Document 1 does not do so. The above-mentioned problem is not known.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to appropriately control the hydraulic pressure at a plurality of locations while suppressing an increase in cost in a belt-type continuously variable transmission for a vehicle. It is to provide a hydraulic control device.

  In order to achieve such an object, the invention according to claim 1 includes: (a) a driving pulley and a driven pulley provided in a power transmission path between a driving power source and driving wheels; One of the wound belt, a driving hydraulic actuator for changing the groove width of the driving pulley, a driven hydraulic actuator for changing the groove width of the driven pulley, and one of the two hydraulic actuators A connected output port, a first input port to which a first hydraulic pressure is supplied, and a second input port to which a second hydraulic pressure is supplied are provided, and the output port and the first input port or the second input port are selectively used. And a hydraulic pressure control device for a continuously variable transmission for a vehicle having a switching valve communicating with the hydraulic pressure sensor for detecting the hydraulic pressure of the output port, wherein (b) the output port communicates with the first input port. In this case, hydraulic control means for controlling the hydraulic pressure of one hydraulic actuator connected to the output port based on the hydraulic pressure detected by the hydraulic pressure sensor, and (c) hydraulic control of the one hydraulic actuator is performed. An oil passage switching means for communicating the output port and the second input port when the vehicle is in a predetermined vehicle state, and (d) the output port and the second input port are connected by the oil passage switching means. And a hydraulic pressure learning means for learning a relationship between the second hydraulic pressure and a control command value for determining the second hydraulic pressure based on the hydraulic pressure detected by the hydraulic pressure sensor.

  In the invention according to claim 2, (a) the second input port is connected to the other of the hydraulic actuators to which the output port is not connected, and (b) the second hydraulic pressure is controlled by the control. (C) the switching valve is output when a drain failure or an open failure occurs in the first pressure regulating valve for regulating the first hydraulic pressure, or the second pressure regulating valve is output from the second pressure regulating valve according to the command value. It is a fail-safe valve that communicates the output port and the second input port when an open-fail occurs in the pressure regulating valve.

  The invention according to claim 3 is characterized in that the predetermined vehicle state where hydraulic control of the one hydraulic actuator is not performed is a case where the vehicle is in a parking state.

  The hydraulic control device for a continuously variable transmission for a vehicle according to a first aspect of the present invention provides: (a) the hydraulic pressure detected by the hydraulic sensor when the output port of the switching valve and the first input port communicate with each other. Hydraulic control means for controlling the hydraulic pressure of one of the hydraulic actuators connected to the output port, and (b) the switching valve in a predetermined vehicle state in which the hydraulic control of the one hydraulic actuator is not performed. An oil passage switching means for communicating the output port and the second input port; and (c) when the output port and the second input port are communicated by the oil passage switching means. Including a hydraulic pressure learning means for learning a relationship between the second hydraulic pressure and a control command value for determining the second hydraulic pressure based on the hydraulic pressure. It is possible to appropriately control the serial first hydraulic and second hydraulic pressure of the two positions hydraulic. Further, since the hydraulic circuit is configured to supply the second hydraulic pressure to the one hydraulic actuator by switching the switching valve, for example, when the first hydraulic pressure becomes uncontrollable, the second hydraulic pressure is reduced. The switching valve can be provided with the function of supplying the hydraulic actuator to the one hydraulic actuator, and the increase in cost due to the function of the switching valve, that is, the purpose of use can be suppressed.

  According to the hydraulic control device for a continuously variable transmission for a vehicle according to the second aspect of the invention, (a) the second input port of the switching valve is connected to the output port of the switching valve of the hydraulic actuators. (B) the second hydraulic pressure is output from the second pressure regulating valve according to the control command value, and (c) the switching valve regulates the first hydraulic pressure. Since the fail-safe valve connects the output port and the second input port when drain failure or open failure occurs in the first pressure regulating valve or when open failure occurs in the second pressure regulating valve, The switching valve is also used as the fail-safe valve, so that the cost can be reduced. When a drain failure or an open failure occurs in the first pressure regulating valve, or when an open failure occurs in the second pressure regulating valve, the fail safe valve (switching valve) is switched, and the output port and the above When the second input port is communicated, the second hydraulic pressure is supplied to both the drive side hydraulic actuator and the driven side hydraulic actuator, and the vehicle continuously variable transmission according to the pressure receiving area difference therebetween. Becomes a predetermined gear ratio.

  Note that the drain failure of the first pressure regulating valve causes the first hydraulic pressure to fall below a predetermined lower limit value where hydraulic control of the first hydraulic pressure is disabled and the one hydraulic actuator cannot be operated properly. It is to decline. In addition, the open failure of the first pressure regulating valve causes the first hydraulic pressure to be higher than a predetermined upper limit value where the hydraulic control of the first hydraulic pressure is disabled and the one hydraulic actuator cannot be operated properly. It is to rise. Further, both the drain failure and the open failure of the first pressure regulating valve are not only mechanical failure due to the valve stick of the first pressure regulating valve, but also the disconnection of the electric system that controls the first pressure regulating valve, Includes electrical failures such as shorts. The drain fail and the open fail of the second pressure regulating valve are the same as those of the first pressure regulating valve.

  According to the hydraulic control device for a continuously variable transmission for a vehicle according to claim 3, the vehicle is in a parking state when the predetermined hydraulic state where the hydraulic control of the one hydraulic actuator is not performed. Therefore, it can be easily determined by detecting the state of the operating device of the vehicle whether the vehicle is in a state where the hydraulic control of the one hydraulic actuator is not performed.

  Preferably, the drive-side hydraulic actuator is connected to an output port of the switching valve, and a drive-side regulator that regulates the hydraulic pressure supplied to the drive-side hydraulic actuator is connected to the first input port of the switch valve. An output port of the first pressure regulating valve as a pressure valve is connected, and the second input port of the switching valve is connected to the driven hydraulic actuator and the second pressure regulating valve that regulates the hydraulic pressure. The output port of the pressure regulating valve is connected. More preferably, the first hydraulic pressure is pressure-controlled so that the gear ratio of the continuously variable transmission for a vehicle matches a target gear ratio that is a target value, and the second hydraulic pressure is a belt that does not cause belt slip. Pressure regulation is controlled so as to generate a clamping pressure.

  Preferably, an engine that is an internal combustion engine such as a gasoline engine or a diesel engine is widely used as the driving power source. Furthermore, an electric motor or the like may be used in addition to the engine as an auxiliary driving power source. Alternatively, only an electric motor may be used as a driving power source.

  The switching valve is configured to include a spool that selectively communicates the output port with the first input port or the second input port by being reciprocated along, for example, one axis. Various modes such as one having a valve body that is rotationally driven are possible. This switching valve is integrally provided with driving means such as a solenoid, an electric motor, and a cylinder, and the valve body is moved by the pilot hydraulic pressure supplied from other solenoid valves even if the valve body is moved by the driving means. Various modes are possible, such as a movable one. As the pilot oil pressure, a dedicated oil pressure can be used, for example, using the output oil pressure of a solenoid valve for controlling the second oil pressure, or using the oil pressure for lock-up clutch control, etc. Various embodiments are possible.

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

  FIG. 1 is a skeleton diagram illustrating the configuration of a vehicle drive device 10 to which the present invention is applied. The vehicle drive device 10 is suitably employed in an FF (front engine / front drive) type vehicle, and includes an engine 12 as a driving power source. The output of the engine 12 composed of an internal combustion engine is output from a torque converter 14 as a fluid transmission device to a forward / reverse switching device 16, a belt type continuously variable transmission 18 (CVT). Is transmitted to the differential gear device 22 via the reduction gear device 20, and distributed to the left and right drive wheels 24L, 24R.

  The torque converter 14 includes a pump impeller 14p connected to the crankshaft of the engine 12 and a turbine impeller 14t connected to the forward / reverse switching device 16 via a turbine shaft 34, and transmits power through a fluid. Is supposed to do. A lockup clutch 26 is provided between the pump impeller 14p and the turbine impeller 14t, and a lockup control valve (L) (not shown) in the hydraulic control circuit 100 (see FIGS. 2 and 3). / C control valve) or the like is switched so that the hydraulic pressure supply to the engagement side oil chamber and the release side oil chamber is switched to be engaged or released, and by being completely engaged, the pump impeller 14p and The turbine impeller 14t is rotated integrally. The pump impeller 14p has a hydraulic pressure for controlling the transmission of the continuously variable transmission 18, generating a belt clamping pressure, controlling the engagement release of the lockup clutch 26, or supplying lubricating oil to each part. A mechanical oil pump 28 that generates

  The forward / reverse switching device 16 is mainly composed of a double pinion type planetary gear device, the turbine shaft 34 of the torque converter 14 is integrally connected to the sun gear 16s, and the input shaft 36 of the continuously variable transmission 18 is a carrier. The carrier 16c and the sun gear 16s are selectively connected via the forward clutch C1, and the ring gear 16r is selectively fixed to the housing via the reverse brake B1. It has become. The forward clutch C1 and the reverse brake B1 correspond to an intermittent device, both of which are hydraulic friction engagement devices that are frictionally engaged by a hydraulic cylinder.

  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, the turbine shaft 34 is directly connected to the input shaft 36, and the forward power transmission path. Is established (achieved), and 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 reverse power transmission path is established (achieved), and the input shaft 36 rotates in the reverse direction with respect to the turbine shaft 34. Thus, the driving force in the reverse direction is transmitted to the continuously variable transmission 18 side. Further, when both the forward clutch C1 and the reverse brake B1 are released, the forward / reverse switching device 16 becomes neutral (interrupted state) for interrupting power transmission.

  The continuously variable transmission 18 has a drive side pulley (primary pulley, primary sheave) 42 with an effective diameter (belt winding diameter) that is an input side member provided on the input shaft 36, that is, a variable groove width, and an output. The driven side pulley (secondary pulley, secondary sheave) 46 having a variable effective diameter (belt winding diameter) that is an output side member provided on the shaft 44, that is, the groove width is variable, and the pulleys 42, 46 are wound around them. A power transmission belt 48 is provided, and power is transmitted through a frictional force between the pulleys 42 and 46 and the power transmission belt 48.

  The pair of pulleys 42 and 46 are a relative rotation about the axis with respect to the input shaft 36 and the output shaft 44, and the driving side fixed rotating body 42 a and the driven side fixed rotating body 46 a fixed to the input shaft 36 and the output shaft 44, respectively. The driving side movable rotating body 42b and the driven side movable rotating body 46b provided so as to be immovable and movable in the axial direction, and the thrust for changing the V groove width between the driving side fixed rotating body 42a and the driving side movable rotating body 42b. A drive side hydraulic cylinder (primary pulley side hydraulic cylinder) 42c as a drive side hydraulic actuator that imparts the following, and a driven that imparts thrust to change the V groove width between the driven fixed rotating body 46a and the driven movable rotating body 46b. And a driven side hydraulic cylinder (secondary pulley side hydraulic cylinder) 46c as a side hydraulic actuator. The primary hydraulic pressure Pin supplied to the drive-side hydraulic cylinder 42c is controlled by the hydraulic control circuit 100, and the supply / discharge flow rate of the hydraulic oil to the drive-side hydraulic cylinder 42c is controlled. The groove width is changed, the winding diameter (effective diameter) of the transmission belt 48 is changed, and the gear ratio γ (= input shaft rotational speed Nin / output shaft rotational speed Nout) is continuously changed. Further, the hydraulic pressure of the driven hydraulic cylinder 46c (secondary hydraulic pressure Pd) is regulated by the hydraulic control circuit 100, whereby the belt clamping pressure is controlled so that the transmission belt 48 does not slip. In this embodiment, the primary hydraulic pressure Pin corresponds to the first hydraulic pressure of the present invention, and the secondary hydraulic pressure Pd corresponds to the second hydraulic pressure of the present invention.

  FIG. 2 is a block diagram illustrating a main part of the control system provided in the vehicle drive device 10 of FIG. The electronic control device 50 that functions as a hydraulic control device for the continuously variable transmission 18 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. By performing signal processing in accordance with a program stored in the ROM in advance, the engine 12 output control, continuously variable transmission 18 speed ratio control, belt clamping pressure control, lockup clutch 26 torque capacity control, etc. It is configured to be divided into an engine control and an oil pressure control for the continuously variable transmission 18 and the lockup clutch 26 as necessary.

Electronic the control unit 50, the rotational speed signal representing the (engine rotational speed) N _E of the engine 12 detected by the engine rotational speed sensor 52, the rotational speed (turbine rotation of the turbine rotational speed sensor 54 the turbine shaft 34 detected by the A signal representing the speed) _NT , a signal representing the rotational speed (input shaft rotational speed) Nin of the input shaft 36, which is the input rotational speed of the continuously variable transmission 18 detected by the input shaft rotational speed sensor 56, and the vehicle speed sensor 58. A signal indicating the rotational speed (output shaft rotational speed) Nout, that is, the rotational speed corresponding to the vehicle speed V, which is the detected output rotational speed of the continuously variable transmission 18, the intake air of the engine 12 detected by the throttle sensor 60. A throttle valve opening signal indicating the throttle valve opening θ _TH of the electronic throttle valve 30 provided in the pipe 32 (see FIG. 1), cooling water Signal representing the cooling water temperature T _W of the engine 12 detected by the temperature sensor 62, the hydraulic fluid temperature (oil temperature) of the continuously variable such as transmission 18 detected by the CVT fluid temperature sensor 64 signals representative of T _CVT, accelerator opening An accelerator opening signal indicating the accelerator opening Acc, which is the operation amount of the accelerator pedal 68 detected by the sensor 66, and a brake operation signal indicating whether or not the foot brake, which is a service brake, is operated B _ON , detected by the foot brake switch 70. and the operation position signal representing a lever position (operating position) P _SH of the shift lever 74 detected by a lever position sensor 72 are supplied.

  The shift lever 74 is disposed in the vicinity of the driver's seat, for example, and is one of five lever positions “P”, “R”, “N”, “D”, and “L” provided in order. To be manually operated. The “P” position is a neutral position (neutral state) in which the power transmission of the vehicle drive device 10 is interrupted, and a parking position (position) for mechanically preventing (locking) the rotation of the output shaft 44 by the mechanical parking mechanism. The “R” position is a reverse travel position (position) for reversing the rotation direction of the output shaft 44, and the “N” position is a neutral state in which the power transmission of the vehicle drive device 10 is interrupted. The “D” position is a forward travel position (position) in which the automatic shift mode is established and the automatic shift control is executed in the shift range in which the shift of the continuously variable transmission 18 is allowed. The “L” position is an engine brake position (position) where a strong engine brake is applied.

On the other hand, the electronic control unit 50 controls the output of the engine 12, for example, a throttle signal for driving a throttle actuator 76 for controlling the opening / closing of the electronic throttle valve 30 and the amount of fuel injected from the fuel injection unit 78. An injection signal for controlling the ignition timing, an ignition timing signal for controlling the ignition timing of the engine 12 by the ignition device 80, and the like are output. Further, the control signal I _SLP for driving the gear ratio control linear solenoid valve SLP for controlling the primary oil pressure Pin related to the speed ratio γ of the continuously variable transmission 18 and the secondary oil pressure Pd related to the belt clamping pressure are set. control signal _{I SLS} for driving the clamping pressure control linear solenoid valve SLS for controlling, and the linear solenoid control signal _{I SLT} that drives the valve SLT is output, the electronic control unit 50 it and the output oil pressure _{P SLP,} P Each of _SLS and P _SLT is controlled to a predetermined hydraulic pressure. Further, a control signal I _SL for driving the ON-OFF solenoid valve _SL is output.

FIG. 3 is a hydraulic circuit diagram showing the main parts of the hydraulic control circuit 100 related to the transmission ratio control of the continuously variable transmission 18 and the belt clamping pressure control. The hydraulic control circuit 100 includes a transmission ratio control linear solenoid valve SLP, a transmission ratio control valve 110 that adjusts the primary hydraulic pressure Pin according to the output hydraulic pressure P _SLP of the transmission ratio control linear solenoid valve SLP, and a clamping pressure control linear solenoid. Valve SLS, output hydraulic pressure P of the linear solenoid valve SLS for controlling the clamping pressure, a clamping pressure control valve 120 for adjusting the secondary hydraulic pressure Pd according to the hydraulic pressure P _SLS , the ON-OFF solenoid valve SL, and the output hydraulic pressure P of the ON-OFF solenoid valve SL _The communication state is selectively switched according to _SL , and the hydraulic pressure for detecting the hydraulic pressure at the output port 130t of the fail safe valve 130 and the fail safe valve 130 disposed between the transmission ratio control valve 110 and the drive side hydraulic cylinder 42c. Sensor 1 2, a linear solenoid valve SLT, and the primary regulator valve 134 which reduces the line pressure PL in accordance with the output hydraulic pressure _{P SLT} of the linear solenoid valve SLT.

The transmission ratio control valve 110 is a pressure control valve that includes an input port 110i to which the line hydraulic pressure PL is supplied and an output port 110t that outputs a primary hydraulic pressure Pin that regulates the line hydraulic pressure PL. by linear solenoid valve SLP output oil pressure P _SLP is controlled in accordance with a control signal I _SLP supplied from the electronic control unit 50, the primary hydraulic Pin is pressure regulated in accordance with the output hydraulic pressure P _SLP. The primary hydraulic pressure Pin adjusted in this way is supplied to the drive side hydraulic cylinder 42c via the fail-safe valve 130. Normally, the primary hydraulic pressure Pin is the primary actual hydraulic pressure Pinp that is the actual hydraulic pressure of the hydraulic cylinder 42c. Thus, the groove width is changed according to the primary actual hydraulic pressure Pinp, and the transmission gear ratio γ is adjusted. The line oil pressure PL is set to a hydraulic pressure value corresponding to the engine load or the like by the relief type primary regulator valve 134 with the working oil pressure output (generated) from the mechanical oil pump 28 rotated and driven by the engine 12 as a source pressure. It is regulated.

FIG. 4A is a diagram showing the relationship between the control signal I _{SLP of the} gear ratio control linear solenoid valve SLP and the output hydraulic pressure P _SLP . When the control signal I _SLP is near 0, the output hydraulic pressure P _SLP is maximized. becomes, the control signal _{I SLP} falls linearly with increases, typically the control signal _{I SLP} is greater than the predetermined value _{I SLP} 1 to predetermined regions, that is, the output hydraulic pressure _{P SLP} to the control signal _{I SLP} Control is performed in a linearly changing region. FIG. 4B shows the relationship between the output oil pressure P _SLP and the primary oil pressure Pin, and the primary oil pressure Pin is linearly increased with respect to the output oil pressure P _SLP . Therefore, the primary hydraulic pressure Pin decreases as the control signal I _SLP increases, and the continuously variable transmission 18 is downshifted so that the gear ratio γ increases, while the primary hydraulic pressure Pin increases as the control signal I _SLP decreases. Then, the continuously variable transmission 18 is upshifted so that the gear ratio γ becomes small.

The clamping pressure control valve 120 includes an input port 120i to which the line hydraulic pressure PL is supplied, and an output port 120t that outputs a secondary hydraulic pressure Pd obtained by adjusting the line hydraulic pressure PL to the driven hydraulic cylinder 46c. The output hydraulic pressure P _{SLS of} the clamping pressure control linear solenoid valve SLS is controlled according to the control signal I _SLS supplied from the electronic control unit 50, so that the secondary hydraulic pressure Pd corresponds to the output hydraulic pressure P _SLS. Is regulated. That is, the secondary hydraulic pressure Pd is output from the clamping pressure control valve 120 in accordance with the control signal _ISLS . Then, the secondary hydraulic pressure Pd adjusted in this way is supplied to the driven hydraulic cylinder 46c, whereby the belt clamping pressure is adjusted according to the secondary hydraulic pressure Pd.

FIG. 5A is a diagram showing the relationship between the control signal I _SLS and the output hydraulic pressure P _SLS of the clamping pressure control linear solenoid valve SLS, and the output hydraulic pressure P _SLS is maximized when the control signal I _SLS is near zero. becomes, the control signal _{I SLS} decreases linearly with increases, normally the control signal _{I SLS} is greater than the predetermined value _{I SLS} 1 a predetermined region, that is, the output hydraulic pressure _{P SLS} to the control signal _{I SLS} Control is performed in a linearly changing region. FIG. 5B shows the relationship between the output oil pressure P _SLS and the secondary oil pressure Pd, and the secondary oil pressure Pd is increased linearly with respect to the output oil pressure P _SLS . Therefore, as the control signal _ISLS increases, the secondary hydraulic pressure Pd decreases and the belt clamping pressure decreases. On the other hand, as the control signal _ISLS decreases, the secondary hydraulic pressure Pd increases and the belt clamping pressure increases.

The fail-safe valve 130 is connected to an output port 110t of the transmission ratio control valve 110, a first input port 130i to which a primary hydraulic pressure (first hydraulic pressure) Pin is supplied from the transmission ratio control valve 110, and a clamping pressure control valve 120. The second input port 130j connected to the output port 120t and the driven hydraulic cylinder 46c and supplied with the secondary hydraulic pressure (second hydraulic pressure) Pd from the clamping pressure control valve 120, the driving hydraulic cylinder 42c and the hydraulic sensor 132. And a switching valve having an output port 130t. The fail safe valve 130 is configured to have a spool that selectively communicates the output port 130t and the first input port 130i or the second input port 130j by being reciprocated along one axis. an output port 130t and the first input port 130i or the second input port 130j selective communication in accordance with the output hydraulic pressure _{P SL} of a pressure (pilot pressure) oN-OFF solenoid valve SL.

During normal control in which the output hydraulic pressure P _{SL of the} ON-OFF solenoid valve SL is 0, the fail-safe valve 130 has a first input port 130i, an output port 130t, and a normal (NORMAL) side as shown in FIG. And a first communication state in which the second input port 130j and the output port 130t are blocked, and the primary hydraulic pressure Pin supplied from the transmission ratio control valve 110 is output to the drive hydraulic cylinder 42c. Thus, in the steady state, the primary actual hydraulic pressure Pinp of the drive side hydraulic cylinder 42c becomes Pin = Pin, and the speed ratio γ is controlled according to the primary hydraulic pressure Pin.

On the other hand, when the output hydraulic pressure P _SL of the ON-OFF solenoid valve SL by a command from the electronic control unit 50 is on a predetermined switching signal pressure or for switching the communication state of the fail-safe valve 130, the fail-safe valve 130, As shown in FIG. 3 as the FAIL side, the second input port 130j and the output port 130t are communicated with each other, and the first input port 130i and the output port 130t are blocked. The secondary hydraulic pressure Pd supplied from the valve 120 is output to the drive side hydraulic cylinder 42c. For example, the fail-safe valve 130 is brought into the second communication state when a drain failure occurs in the transmission ratio control valve (first pressure regulating valve) 110. As a result, the primary actual hydraulic pressure Pinp = Pd of the drive side hydraulic cylinder 42c is obtained, and the continuously variable transmission 18 has a predetermined speed ratio γ determined by the pressure receiving area difference between the hydraulic cylinders 42c and 46c, for example, “speed ratio γ = 1”. become.

The primary regulator valve 134 is a relief type pressure regulating valve, and _reduces the line oil pressure PL to a value corresponding to the throttle valve opening θ _TH or the like based on the output oil pressure (signal pressure) P _SLT from the linear solenoid valve SLT.

  In the present embodiment, the transmission ratio control valve 110 constitutes the first pressure regulating valve of the present invention together with the transmission ratio control linear solenoid valve SLP, and the clamping pressure control valve 120 is combined with the clamping pressure control linear solenoid valve SLS. The 2nd pressure regulation valve of invention is comprised, and the fail safe valve 130 comprises the switching valve of this invention with ON-OFF solenoid valve SL.

  FIG. 6 is a functional block diagram for explaining the main part of the control function by the electronic control unit 50. As shown in FIG. 6, the electronic control unit 50 includes a transmission ratio control unit 150, a belt clamping pressure control unit 152, a fail determination unit 160, a fail safe unit 162, a learning execution determination unit 170, an oil path switching unit 172, The hydraulic learning means 174 is functionally provided.

The transmission ratio control means 150 corresponding to the hydraulic control means of the present invention is the primary actual hydraulic pressure detected by the hydraulic sensor 132 when the fail-safe valve 130 is in the first communication state (NORMAL side in FIG. 3). Based on Pinp (= Pin), hydraulic control of the drive side hydraulic cylinder 42c is performed. Specifically, the gear ratio control means 150 obtains the target rotational speed Nint of the input shaft rotational speed Nin of the continuously variable transmission 18 from a map set in advance using the accelerator opening Acc and the vehicle speed V as parameters as shown in FIG. The control signal I _SLP of the speed ratio control linear solenoid valve SLP is feedback controlled in a region larger than the predetermined value I _SLP 1 while the primary actual hydraulic pressure Pinp (= Pin) is detected by the hydraulic pressure sensor 132. Then, the gear ratio control of the continuously variable transmission 18 is executed to control the primary hydraulic pressure Pin supplied to the drive side hydraulic cylinder 42c so that the actual input shaft rotational speed Nin matches the target rotational speed Nint. The gear ratio γ is the input shaft rotational speed Nin / output shaft rotational speed Nout, and the output shaft rotational speed Nout is constant in a short time corresponding to the vehicle speed V. Therefore, the target rotational speed Nint is based on the vehicle speed V at that time. Is controlled so that the input shaft rotational speed Nin matches the target rotational speed Nint, so that the gear ratio γ is substantially controlled to match the target speed ratio. The map of FIG. 7 shows that the ratio of the target rotational speed Nint to the vehicle speed V increases and the speed ratio γ increases as the accelerator opening Acc, that is, the driver's required output amount increases and the vehicle speed V decreases. Determined.

For example, as shown in FIG. 8, the belt clamping pressure control means 152 uses the accelerator opening Acc corresponding to the transmission torque and the transmission gear ratio γ as parameters so that the belt clamping pressure control means 152 is as low as possible in order to improve the fuel consumption without causing belt slip. A target secondary hydraulic pressure Pd ^* is obtained from a predetermined target secondary hydraulic pressure Pd ^* map, and the control signal I _SLS of the clamping pressure control linear solenoid valve SLS is in a region larger than the predetermined value I _SLS 1 and the secondary hydraulic pressure Pd. Is controlled to be the target secondary hydraulic pressure Pd ^* . Here, as shown in FIG. 3, a hydraulic pressure sensor capable of directly detecting the actual secondary hydraulic pressure Pd is provided in the hydraulic pressure control circuit 100 in a normal state when the fail safe valve 130 is in the first communication state (NORMAL side in FIG. 3). Therefore, the belt clamping pressure control means 152 performs the secondary hydraulic pressure Pd and its secondary hydraulic pressure Pd as exemplified in FIGS. 5A and 5B in the belt clamping pressure control which is the control of the secondary hydraulic pressure Pd. The secondary hydraulic pressure map which is the relationship with the control signal _ISLS as the control command value for determining the control signal is stored in advance, and the control is performed so as to adjust the pressure to the secondary hydraulic pressure Pd corresponding to the control signal _ISLS according to the secondary hydraulic map. The signal I _SLS is output. When the secondary hydraulic pressure map is changed (updated) by a hydraulic pressure learning means 174 described later, the belt clamping pressure control means 152 controls the secondary hydraulic pressure Pd according to the changed (updated) secondary hydraulic pressure map. . Further, a hydraulic sensor for detecting the hydraulic pressure of the driven hydraulic cylinder 46c, that is, the actual secondary hydraulic pressure Pd may be provided as necessary. In this embodiment, such a hydraulic sensor is shown in FIG. Not provided as shown. According to the map shown in FIG. 8, the target secondary oil pressure Pd ^* is increased and the belt clamping pressure is increased as the accelerator opening Acc, that is, the driver's required output amount is increased and the speed ratio γ is increased. It is done. Since the secondary hydraulic pressure Pd corresponds to the belt clamping pressure, the secondary hydraulic pressure Pd can be controlled using a map of the target belt clamping pressure instead of the target secondary hydraulic pressure Pd ^* .

  For example, when the shift lever 74 is operated to a travel position such as the D position, the fail determination unit 160 detects and determines whether a drain failure or an open failure has occurred in the transmission ratio control valve 110.

In the drain failure of the gear ratio control valve 110, the primary oil pressure Pin is lowered to a predetermined lower limit value where the oil pressure control of the primary oil pressure Pin becomes impossible and the belt clamping pressure or the gear ratio γ cannot be properly controlled. That is. Further, the open fail of the gear ratio control valve 110 causes the primary oil pressure Pin to rise to a predetermined upper limit value where the oil pressure control of the primary oil pressure Pin becomes impossible and the belt clamping pressure or the gear ratio γ cannot be properly controlled. It is to be. Further, the drain failure and the open failure of the transmission ratio control valve 110 include a mechanical failure caused by a valve stick or the like of the transmission ratio control valve 110 itself, and the primary hydraulic pressure Pin via the transmission ratio control valve 110 by the output hydraulic pressure P _SLP. Also included is a mechanical failure of a linear solenoid valve SLP for speed ratio control that regulates pressure. Further, the drain failure of the transmission ratio control valve 110 causes the control signal I _SLP to become maximum due to a short circuit in the electric system, the output hydraulic pressure P _SLP becomes 0, and the primary hydraulic pressure Pin output from the transmission ratio control valve 110 is the above-described value. The open fail of the gear ratio control valve 110 includes a case where the control signal I _SLP becomes 0 due to disconnection of the electric system, the output oil pressure P _SLP becomes maximum, and the primary oil pressure Pin Includes a case where is equal to or greater than the predetermined upper limit value.

  Further, the fail determination means 160 detects and determines whether or not an open failure has occurred in the clamping pressure control valve 120 when, for example, the shift lever 74 is operated to a travel position such as the D position.

In the open failure of the clamping pressure control valve 120, the secondary hydraulic pressure Pd rises to a predetermined upper limit value or more where the secondary hydraulic pressure Pd cannot be controlled and the belt clamping pressure or the gear ratio γ cannot be controlled appropriately. It is. Furthermore, the open pressure of the clamping pressure control valve 120 is regulated by adjusting the secondary hydraulic pressure Pd via the clamping pressure control valve 120 by the output hydraulic pressure P _{SLS in} addition to a mechanical failure such as a valve stick of the clamping pressure control valve 120 itself. The control signal I _SLS becomes 0 by the mechanical failure of the linear solenoid valve SLS for controlling the clamping pressure or the disconnection of the electric system, the output hydraulic pressure P _SLS becomes maximum, and the secondary hydraulic pressure Pd becomes equal to or higher than the predetermined upper limit value. It is included.

When the drain failure of the transmission ratio control valve 110 or the open failure of the clamping pressure control valve 120 as described above occurs, the transmission ratio γ of the continuously variable transmission 18 increases due to a decrease in the primary actual oil pressure Pinp or an increase in the secondary oil pressure Pd. Therefore, for example, whether the actual input shaft rotational speed Nin is larger than the target rotational speed Nint by a predetermined value or more has continued for a certain period of time, or the actual speed ratio corresponding to the target rotational speed Nint is actually Depending on whether or not the state in which the speed ratio γ is greater than a predetermined value has continued for a predetermined time or more, the failure determination means 160 can determine whether a drain failure of the speed ratio control valve 110 or an open failure of the clamping pressure control valve 120 has occurred. . Further, when it is determined that a drain failure of the transmission ratio control valve 110 or an open failure of the clamping pressure control valve 120 has occurred, the fail determination means 160 detects the primary actual oil pressure Pinp by the oil pressure sensor 132 and If it is determined that the transmission ratio control valve 110 is operating normally based on the relationship with the change in the control signal I _SLP , an open failure occurs in the clamping pressure control valve 120 instead of the drain failure of the transmission ratio control valve 110. It can also be judged (estimated). A short circuit in an electrical system such as a solenoid can also be detected electrically.

Further, as to whether or not a drain failure or an open failure has occurred in the transmission ratio control valve 110, for example, the fail determination means 160 detects the primary actual oil pressure Pinp by the oil pressure sensor 132, and changes the oil pressure and the control signal I _SLP . Judgment (estimation) can be made based on the relationship with changes.

The fail-safe means 162 is turned ON / OFF when the fail determination means 160 determines that a drain failure or an open failure has occurred in the transmission ratio control valve 110 or an open failure has occurred in the pinching pressure control valve 120. the output oil pressure P _SL solenoid valve SL in the predetermined switching signal on pressure or switching to the fail-safe valve 130 first communication state second communication state from the (normal side) (fail side), i.e., the fail-safe valve 130 The second input port 130j and the output port 130t are connected to each other, and the first input port 130i and the output port 130t are blocked. As a result, the secondary hydraulic pressure Pd is supplied to the drive side hydraulic cylinder 42c, and the continuously variable transmission 18 has a predetermined speed ratio γ, for example, “speed ratio γ = 1”.

  Here, assuming that the fail-safe valve 162 is not switched to the fail side by the fail-safe means 162, when a drain failure occurs in the transmission ratio control valve 110, the primary actual oil pressure Pinp is suddenly lowered and thus continuously variable. If the gear ratio γ of the transmission 18 suddenly increases and an open-fail occurs in the gear ratio control valve 110, the gear ratio γ of the continuously variable transmission 18 is minimized due to a sudden rise in the primary actual hydraulic pressure Pinp. When the ratio γmin is reached, the durability of the transmission belt 48 decreases. Further, when an open failure occurs in the clamping pressure control valve 120, the transmission gear ratio γ of the continuously variable transmission 18 suddenly increases. Therefore, as described above, the fail-safe means 162 switches the fail-safe valve 130 based on the determination of the fail determination means 160, thereby causing inconvenience caused by the drain failure or the open failure of the transmission ratio control valve 110 and the clamping pressure control valve 120. Inconveniences caused by an open failure, that is, the gear ratio γ suddenly increases, the gear ratio γ becomes the minimum gear ratio γmin, and the durability of the transmission belt 48 is prevented.

The learning execution determination unit 170 determines whether or not the vehicle state is a predetermined vehicle state in which the hydraulic control of the drive side hydraulic cylinder 42c is not performed, that is, the actual input shaft rotational speed Nin is set to the target rotational speed by the transmission ratio control unit 150. It is determined whether or not the vehicle state is a predetermined vehicle state in which the hydraulic pressure control (speed ratio control of the continuously variable transmission 18) in which the primary hydraulic pressure Pin is changed so as to coincide with Nint is not performed. Above a predetermined vehicle condition, a hydraulic learnable state learning is previously configured as vehicle condition viable relationship with the secondary hydraulic Pd and its control command value (control signal) I _SLS, for example, When the shift lever 74 is in the “P” position, that is, when the vehicle is in a parking state, or when the vehicle is repaired, an externally connected computer sends the secondary hydraulic pressure Pd and its control command value (control signal) I _SLS to the electronic control unit 50. For example, a command for learning the relationship is input. Further, the learning execution determination unit 170 may affirm that the vehicle state is in the predetermined state by adding that the condition that the vehicle has been warmed up is affirmed. For example, when the vehicle has been warmed up and the shift lever 74 is in the “P” position, it is affirmed that the vehicle state is in the predetermined state. Note that learning of the relationship between the secondary hydraulic pressure Pd and its control command value (control signal) _ISLS does not need to be executed frequently. If the predetermined time has not elapsed since the time of affirming that the vehicle has been affirmed, the vehicle state may not be affirmed.

  The oil passage switching means 172 causes the fail-safe valve 130 to communicate with the second communication when the learning execution judging means 170 affirms that the vehicle state is a predetermined vehicle state in which the hydraulic control of the drive side hydraulic cylinder 42c is not performed. State (FAIL side in FIG. 3). As a result, the second input port 130j and the output port 130t of the fail safe valve 130 are communicated with each other, and the first input port 130i and the output port 130t are blocked. That is, the hydraulic pressure sensor 132 connected to the output port 130t can detect the secondary hydraulic pressure (second hydraulic pressure) Pd.

The hydraulic pressure learning means 174 is configured to perform hydraulic pressure when the second input port 130j and the output port 130t of the fail safe valve 130 are communicated by the oil path switching means 172, that is, when the fail safe valve 130 is in the second communication state. Based on the secondary hydraulic pressure (second hydraulic pressure) Pd detected by the sensor 132, the relationship between the secondary hydraulic pressure Pd and the control command value (control signal) _ISLS that determines the secondary hydraulic pressure Pd is learned. The secondary hydraulic pressure map stored in the pressure control means 152 is updated. Specifically, when the fail safe valve 130 is in the second communication state, the oil pressure learning unit 174 gradually changes (sweeps) the control command value I _SLS and is detected by the oil pressure sensor 132 at that time. The secondary hydraulic pressure Pd is sequentially detected, and a new secondary hydraulic pressure map is completed from the control command value _ISLS and the secondary hydraulic pressure Pd detected correspondingly. After the completion, the oil pressure learning means 174 changes (updates) the secondary oil pressure map stored in the belt clamping pressure control means 152 to a new secondary oil pressure map completed by itself. Here, when the secondary oil pressure map is composed of two relationships as illustrated in FIGS. 5A and 5B, the oil pressure learning unit 174 changes, for example, in FIG. It is possible to update only FIG.

FIG. 9 is a flow chart for explaining the control operation for learning the main part of the control operation of the electronic control unit 50, that is, the relationship between the secondary hydraulic pressure Pd and the control command value I _SLS for determining the secondary oil pressure Pd. It is repeatedly executed with an extremely short cycle time of about 10 msec.

  First, in a step (hereinafter, step is omitted) SA1 corresponding to the learning execution determination unit 170, the hydraulic control of the drive side hydraulic cylinder 42c (speed ratio control of the continuously variable transmission 18) is not performed. Whether or not the vehicle is in a state, that is, hydraulic control (speed ratio control of the continuously variable transmission 18) is performed in which the primary hydraulic pressure Pin is changed so that the actual input shaft rotational speed Nin matches the target rotational speed Nint. It is determined whether or not there is a predetermined vehicle state. If the determination of SA1 is affirmative, that is, if it is determined that the vehicle state is the predetermined vehicle state in which the hydraulic control of the drive side hydraulic cylinder 42c is not performed, the process proceeds to SA2. On the other hand, if the determination of SA1 is negative, the flowchart of FIG. 9 ends.

  In SA2 corresponding to the oil passage switching means 172, the fail safe valve 130 is set to the second communication state (FAIL side in FIG. 3). As a result, the second input port 130j and the output port 130t of the fail safe valve 130 are communicated with each other, and the first input port 130i and the output port 130t are blocked. After SA2, the process proceeds to SA3.

In SA3 corresponding to the oil pressure learning means 174, learning of the relationship between the secondary oil pressure Pd and the control command value I _SLS for determining it is executed. Specifically, in the learning, the control command value I _SLS is gradually changed (sweep), and the secondary hydraulic pressure Pd detected by the hydraulic sensor 132 is sequentially detected accordingly, and the control command value I _SLS and the corresponding control command value I _SLS are correspondingly detected. The relationship with the detected secondary hydraulic pressure Pd is stored, and a new secondary hydraulic pressure map is completed. After SA3, the process proceeds to SA4.

  In SA4 corresponding to the oil pressure learning means 174, the secondary oil pressure map used in the belt clamping pressure control is updated to the new secondary oil pressure map completed in SA3.

According to the present embodiment, the gear ratio control means 150 uses the primary actual oil pressure Pinp (detected by the oil pressure sensor 132 when the fail-safe valve 130 is in the first communication state (NORMAL side in FIG. 3). = Pin), the gear ratio control of the continuously variable transmission 18 is executed. Further, the oil path switching means 172 fails when the learning execution judging means 170 affirms that it is a predetermined vehicle state in which the hydraulic control of the drive side hydraulic cylinder 42c (the gear ratio control) is not performed. The safe valve 130 is set to the second communication state (FAIL side in FIG. 3). Then, the oil pressure learning means 174 uses the secondary oil pressure based on the secondary oil pressure (second oil pressure) Pd detected by the oil pressure sensor 132 when the fail safe valve 130 is brought into the second communication state by the oil path switching means 172. The relationship between Pd and the control command value I _SLS for determining it is learned, and the secondary hydraulic pressure map stored in the belt clamping pressure control means 152 is updated based on the learned relationship. Therefore, it is not necessary to provide two oil pressure sensors, and by providing one oil pressure sensor 132, the oil pressure at two locations of the primary oil pressure Pin (first oil pressure) and the secondary oil pressure Pd (second oil pressure) is appropriately controlled. It is possible. Further, the hydraulic control circuit 100 of FIG. 3 can supply the hydraulic pressure other than the primary hydraulic pressure Pin, specifically, the secondary hydraulic pressure Pd to the drive side hydraulic cylinder 42c by switching the fail safe valve 130 to the second communication state. Since the circuit configuration is employed, the fail safe valve 130 also has a function of supplying the secondary hydraulic pressure Pd to the drive side hydraulic cylinder 42c when the primary hydraulic pressure Pin becomes uncontrollable. It is suppressed that the cost increases in relation to the function fulfilled, that is, the purpose of use.

  Further, according to the present embodiment, the second input port 130j of the fail safe valve 130 is connected to the output port 120t of the clamping pressure control valve 120 and the driven hydraulic cylinder 46c, and the fail safe means 162 is a fail determination means. When it is determined by 160 that a drain failure or an open failure has occurred in the transmission ratio control valve 110, or when it is determined that an open failure has occurred in the clamping pressure control valve 120, the second input port 130j and the output are output to the fail safe valve 130. When the port 130t is communicated and the first input port 130i and the output port 130t are blocked, the fail-safe valve 130 causes a drain failure or an open failure in the transmission ratio control valve 110. Or, it can be said that it has both a fail-safe valve function that switches when an open-fail occurs in the clamping pressure control valve 120 and a function that supplies a plurality of hydraulic pressures (Pin, Pd) to the hydraulic pressure sensor 132 as necessary. . Therefore, compared with the case where the hydraulic control circuit 100 is provided with an independent switching valve for each of the above functions, an increase in cost due to the function performed by the fail safe valve 130 is suppressed. Then, when a drain failure or an open failure occurs in the gear ratio control valve 110 by the failure determination means 160 or an open failure occurs in the clamping pressure control valve 120, the communication state of the fail safe valve 130 is switched and the second state is changed. When the input port 130j and the output port 130t are communicated and the first input port 130i and the output port 130t are shut off, the primary actual hydraulic pressure Pinp = Pd of the drive side hydraulic cylinder 42c is obtained, and the continuously variable transmission 18 is connected to the hydraulic cylinder. The gear ratio γ of the continuously variable transmission 18 increases due to a decrease in the primary oil pressure Pin or an increase in the secondary oil pressure Pd, for example, when the gear ratio γ is determined by the pressure receiving area difference between 42c and 46c. The ratio γmax can be prevented. Alternatively, it is possible to prevent the transmission gear ratio γ of the continuously variable transmission 18 from becoming the minimum transmission gear ratio γmin due to the increase in the primary hydraulic pressure Pin.

Further, according to the present embodiment, in SA1 of the flowchart of FIG. 9, it is determined whether or not the vehicle state is a predetermined vehicle state in which the hydraulic control of the drive side hydraulic cylinder 42c is not performed. the vehicle state, a hydraulic learnable state of being previously set as the vehicle state learning that is executable relationship with secondary hydraulic Pd and its control command value (control signal) I _SLS, for example, the shift lever 74 is The case where the vehicle is in the “P” position, that is, the vehicle is in a parking state. The easily by detecting the lever position P _SH of the shift lever 74 by the lever position sensor 72 if the determination in SA1 is positive when such a shift lever 74 is in the "P" position, the hydraulic It is possible to determine whether or not learning is possible.

Further, according to the present embodiment, when appropriate, the relationship between the secondary oil pressure Pd and the control command value I _SLS for determining the secondary oil pressure Pd is learned by the oil pressure learning means 174, whereby the belt clamping pressure control means 152 performs belt clamping pressure control. Since the secondary hydraulic pressure map to be used is updated, the accuracy of the secondary hydraulic pressure map is improved, and it is not necessary to allow a large margin for the secondary hydraulic pressure Pd to prevent belt slipping. As a result, the belt clamping pressure during traveling is reduced. It is possible to improve fuel efficiency.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this is only one Embodiment to the last, This invention can also be implemented in another aspect.

  For example, in the above-described embodiment, the output port 120t of the clamping pressure control valve 120 is directly connected to the driven hydraulic cylinder 46c, and the fail-safe valve 130 is interposed between the transmission ratio control valve 110 and the driving hydraulic cylinder 42c. The drive side hydraulic cylinder 42c is configured to correspond to "one hydraulic actuator" in the present invention. However, a hydraulic circuit configuration in which the disposition position of the fail safe valve 130 may be reversed may be used. . That is, the output port 110t of the transmission ratio control valve 110 is directly connected to the drive side hydraulic cylinder 42c, the fail safe valve 130 is provided between the clamping pressure control valve 120 and the driven side hydraulic cylinder 46c, and the output port 130t. Is connected to the hydraulic pressure sensor 132. When a drain failure or an open failure occurs in the clamping pressure control valve 120, the communication state of the fail safe valve 130 is switched so that the primary hydraulic pressure Pin is supplied to the driven hydraulic cylinder 46c. It may be. In such a hydraulic circuit configuration, the driven hydraulic cylinder 46c corresponds to “one hydraulic actuator” in the present invention so that the primary hydraulic pressure Pin is supplied to the driven hydraulic cylinder 46c and the hydraulic sensor 132. The fail safe valve 130 is switched, and the relationship between the primary oil pressure Pin and its control command value is learned.

  In the above-described embodiment, the secondary hydraulic pressure Pd is supplied to the second input port 130j of the failsafe valve 130. However, the brake hydraulic pressure for engaging the reverse brake B1 is used instead of the secondary hydraulic pressure Pd. Other hydraulic pressures exemplified by a clutch hydraulic pressure for engaging the forward clutch C1 and a lock-up hydraulic pressure for engaging the lock-up clutch 26 are supplied to the second input port 130j. Also good. In this way, when the second input port 130j and the output port 130t of the failsafe valve 130 are communicated with each other, it is possible to learn the relationship between the other hydraulic pressure and the control command value that determines it. is there. Further, when a drain failure or an open failure occurs in the transmission ratio control valve 110 or when an open failure occurs in the clamping pressure control valve 120, the fail safe valve 130 is set in the second communication state so that the other hydraulic pressure is driven. By supplying the hydraulic cylinder 42c, the continuously variable transmission 18 can have a gear ratio corresponding to the other hydraulic pressure.

Further, in the above-described embodiment, not only the hydraulic sensor 132 but also the drive side hydraulic cylinder 42c is connected to the output port 130t of the fail safe valve 130, so that the drive side hydraulic cylinder 42c is connected via its piston. The detection value of the hydraulic sensor 132 may be shifted due to leakage of hydraulic oil from one oil chamber to the other oil chamber. Therefore, after preliminarily storing a correction value that takes into account the deviation of the detection value of the hydraulic sensor 132 and performing correction based on the correction value in the new secondary hydraulic pressure map completed in SA3 of FIG. The secondary hydraulic pressure map used in the belt clamping pressure control may be updated in SA4. For example, the clamping pressure control valve 120 is opposed to the urging force of the return spring by supplying a spool that can reciprocate along one axis, a return spring that urges in one direction along the one axis, and an output hydraulic pressure. A hydraulic oil pressure reduction amount ΔP corresponding to a deviation in the detected value of the hydraulic sensor 132 is provided in the case of a pressure control valve that regulates the output hydraulic pressure according to the position of the spool. If the spring constant of the spring is “k”, the amount of movement of the spool is “ΔX”, and the pressure receiving area difference of the feedback oil chamber is “S _FB ”, the following equation (1) is obtained.
ΔP = k × ΔX / S _FB (1)

  In the above-described embodiment, the fail-safe valve 130 has a spool that selectively communicates the output port 130t with the first input port 130i or the second input port 130j by being reciprocated along one axis. However, the present invention is not limited to such a structure, and various modes such as one having a valve body that is rotationally driven around one center line are possible.

Further, although in the foregoing embodiments, the fail-safe valve 130 is switched to its communicating state according to the output hydraulic pressure P _SL of the ON-OFF solenoid valve SL is the signal pressure (pilot pressure), as the signal pressure, nip output and pressure P _SLS pressure control linear solenoid valve SLS, various aspects, such as utilizing the lock-up hydraulic pressure for controlling the lock-up clutch 26 is possible. Further, the fail safe valve 130 may be a switching valve that is not directly operated by the signal pressure but is directly operated by a solenoid. The gear ratio control valve 110 and the clamping pressure control valve 120 may also be directly actuated by solenoids.

  In the above-described embodiment, the continuously variable transmission 18 has the gear ratio γ continuously changed. For example, the continuously variable transmission 18 has a gear ratio γ that is not continuously changed. It may be changed.

  In the above-described embodiment, an engine that is an internal combustion engine such as a gasoline engine or a diesel engine is widely used as the engine 12 that is the driving power source. Furthermore, an electric motor or the like may be used in addition to the engine 12 as an auxiliary traveling power source. Alternatively, only an electric motor may be used as a driving power source.

In the above-described embodiment, the input shaft rotational speed Nin and the related target rotational speed Nint used in the gear ratio control of the continuously variable transmission 18 are changed to the engine rotational speed instead of the input shaft rotational speed Nin. such as N _E and the target engine rotational speed N _E associated therewith ^*, or a turbine rotational speed N _T and the target turbine rotational speed N _T associated therewith ^* may be used. Accordingly, a rotational speed sensor such as the input shaft rotational speed sensor 56 may be appropriately provided in accordance with the rotational speed that needs to be controlled.

  In the above-described embodiment, the torque converter 14 provided with the lock-up clutch 26 is used as the fluid transmission device. However, the lock-up clutch 26 is not necessarily provided. In addition, other fluid type power transmission devices such as a fluid coupling (fluid coupling) having no torque amplification function may be used.

  In the above-described embodiment, the variable pulleys 42 and 46 are respectively provided with hydraulic cylinders 42c and 46c that apply thrust to change the V groove width, but the hydraulic cylinders 42c and 46c are the variable pulleys. 42 and 46 may be provided in the continuously variable transmission 18 as separate components instead of being integrated.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

1 is a skeleton diagram illustrating a vehicle drive device to which the present invention is applied. It is a block diagram explaining the principal part of the control system provided in the vehicle in order to control the vehicle drive device etc. of FIG. FIG. 3 is a hydraulic circuit diagram showing a main part related to a transmission ratio control and a belt clamping pressure control of a continuously variable transmission in the hydraulic control circuit of FIG. 2. Output hydraulic pressure characteristics of the gear ratio control linear solenoid valve SLP of FIG. 3 and its output hydraulic pressure It is a figure which shows the hydraulic characteristic of the gear ratio control valve controlled by this. It is a figure which shows the hydraulic pressure characteristic of the output hydraulic pressure characteristic of the linear solenoid valve SLS for clamping pressure control of FIG. 3, and the clamping pressure control valve controlled by the output hydraulic pressure. It is a functional block diagram explaining the principal part of the control function by the electronic controller of FIG. FIG. 2 is a diagram showing an example of a shift map used when obtaining a target rotation speed in the gear ratio control of the continuously variable transmission for the vehicle in FIG. 1. FIG. 2 is a diagram showing an example of a hydraulic pressure map used when obtaining a target secondary hydraulic pressure in belt clamping pressure control of the continuously variable transmission for the vehicle in FIG. 1. 3 is a flowchart illustrating a control operation for learning a main part of a control operation of the electronic control device of FIG. 2, that is, a relationship between a secondary hydraulic pressure and a control command value for determining the secondary hydraulic pressure.

Explanation of symbols

12: Engine (power source for running)
18: continuously variable transmission (vehicle continuously variable transmission)
24L, 24R: driving wheel 42: driving pulley 42c: driving hydraulic cylinder (driving hydraulic actuator, one hydraulic actuator)
46: driven pulley 46c: driven hydraulic cylinder (driven hydraulic actuator)
48: Transmission belt (belt)
50: Electronic control device (hydraulic control device)
110: Gear ratio control valve (first pressure regulating valve)
120: Nipping pressure control valve (second pressure regulating valve)
130: Fail-safe valve (switching valve)
130i: first input port 130j: second input port 130t: output port 132: oil pressure sensor 150: gear ratio control means (hydraulic control means)
172: Oil passage switching means 174: Oil pressure learning means Pin: Primary oil pressure (first oil pressure)
Pd: Secondary hydraulic pressure (second hydraulic pressure)
I _SLS : Control signal (control command value)

Claims (3)

A driving pulley and a driven pulley provided in a power transmission path between a driving power source and driving wheels, a belt wound around both pulleys, and a groove width of the driving pulley are changed. A drive-side hydraulic actuator, a driven-side hydraulic actuator for changing the groove width of the driven-side pulley, an output port connected to one of the hydraulic actuators, a first input port to which a first hydraulic pressure is supplied, and a first A switching valve that selectively connects the output port with the first input port or the second input port, and a hydraulic pressure sensor that detects the hydraulic pressure of the output port. A hydraulic control device for a continuously variable transmission for a vehicle,
Hydraulic control means for performing hydraulic control of one hydraulic actuator connected to the output port based on the hydraulic pressure detected by the hydraulic sensor when the output port and the first input port are in communication;
An oil path switching means for communicating between the output port and the second input port in a predetermined vehicle state in which hydraulic control of the one hydraulic actuator is not performed;
When the output port and the second input port are communicated by the oil path switching means, the second hydraulic pressure and a control command value for determining the second hydraulic pressure are determined based on the hydraulic pressure detected by the hydraulic pressure sensor. A hydraulic control device for a continuously variable transmission for a vehicle, comprising: hydraulic learning means for learning a relationship. The second input port is connected to the other of the hydraulic actuators to which the output port is not connected,
The second hydraulic pressure is output from the second pressure regulating valve according to the control command value,
The switching valve includes the output port and the second input when a drain failure or an open failure occurs in the first pressure regulating valve that regulates the first hydraulic pressure, or when an open failure occurs in the second pressure regulating valve. The hydraulic control device for a continuously variable transmission for a vehicle according to claim 1, wherein the hydraulic control device is a fail-safe valve that communicates with a port. The continuously variable transmission for a vehicle according to claim 1 or 2, wherein the predetermined vehicle state in which hydraulic control of the one hydraulic actuator is not performed is a case where the vehicle is in a parking state. Hydraulic control device for the machine.

Images