JP2009250304A - Hydraulic control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic control device capable of avoiding occurrence of a rapid deceleration state in a belt type continuously-variable transmission without adding a new solenoid valve. <P>SOLUTION: The hydraulic control device is equipped with a fail-safe valve 305 capable of switching hydraulic pressure to be supplied to a primary pulley 41 between output hydraulic pressure of a gearshift hydraulic pressure control valve 301 and hydraulic pressure different from the output hydraulic pressure. The fail-safe valve 305 is switched to a fail position for supplying the different hydraulic pressure to the primary pulley 41 when there is possibility that a rapid deceleration state will occur, and is otherwise switched to a normal position for supplying the output hydraulic pressure of the gearshift hydraulic pressure control valve 301 to the primary pulley 41. The switchover of the fail-safe valve 305 is controlled by control hydraulic pressure of an ON-OFF solenoid (SL) 204 and control hydraulic pressure of a duty solenoid (DSU) 203. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hydraulic control device for a vehicle power transmission device.

  As a power transmission device mounted on a vehicle, a belt-type continuously variable transmission that changes the gear ratio by changing the belt engagement diameter while transmitting the power by clamping the belt with hydraulic pressure, the fluid type provided in the power transmission path A hydraulic lockup clutch that is provided in the power transmission device and directly connects the power source side and the belt-type continuously variable transmission side, and for hydraulic traveling that is engaged to establish a power transmission path when the vehicle travels One having a friction engagement element (such as a forward clutch) is known.

Such a hydraulic control device for a vehicle power transmission device is provided with a large number of various control valves and electromagnetic valves for controlling the control valves (see, for example, Patent Documents 1 to 4). For example, a line pressure control valve that regulates the line pressure that is the source pressure (control source pressure) of each part, and the line pressure that is the source pressure is regulated to control the gear ratio of the belt-type continuously variable transmission. The transmission hydraulic pressure control valve that supplies the transmission hydraulic pressure to the drive pulley (primary pulley) of the belt type continuously variable transmission, and also regulates the belt clamping pressure of the belt type continuously variable transmission by adjusting the line pressure that is the original pressure. Nipping oil pressure control valve that supplies the nipping oil pressure to the driven pulley (secondary pulley) of the belt-type continuously variable transmission, lockup control valve that operates during the engagement / release control of the lockup clutch, and the friction coefficient for traveling A friction engagement element supply hydraulic pressure switching valve (garage control valve) that can switch the hydraulic pressure supplied to the combination element according to the transitional transition state or complete engagement state of the traveling friction engagement element is provided. In addition, electromagnetic valves such as linear electromagnetic valves, ON-OFF electromagnetic valves, duty electromagnetic valves, and the like are provided.
JP-A-3-213773 JP 2006-316819 A JP 2006-207478 A JP 2007-263260 A

  By the way, in a hydraulic control apparatus, a failure due to a mechanical factor such as a valve stick or a failure due to an electrical factor such as a disconnection or a short circuit (short) may occur in a control valve or a solenoid valve. Specifically, when the transmission hydraulic pressure control valve or the solenoid valve that controls it fails, the transmission hydraulic pressure for controlling the transmission gear ratio suddenly decreases, and as a result, a sudden deceleration state may occur. Then, there is a possibility that belt slip or over lev will occur. However, the above-mentioned Patent Document 1 does not describe how to deal with such a failure.

  As a countermeasure for avoiding the sudden deceleration at the time of failure as described above, it is conceivable that a fail-safe valve having a backup function is provided in the hydraulic control device as shown in Patent Documents 2, 3, and 4. However, in order to control such a fail-safe valve, another electromagnetic valve or the like is required, and there is a problem that the cost is increased and the size of the apparatus is increased.

  The present invention has been made in view of such problems, and provides a hydraulic control device that can avoid the occurrence of a sudden deceleration state in a belt-type continuously variable transmission without adding a new solenoid valve. The purpose is to do.

  In the present invention, means for solving the above-described problems are configured as follows. That is, the present invention provides a belt type continuously variable transmission that transmits power by clamping a belt with hydraulic pressure, changes a belt engagement diameter and changes a gear ratio, a power source, and the belt type continuously variable transmission. A hydraulic lock-up clutch that is provided in a fluid-type power transmission device provided therebetween and directly connects the power source side and the belt-type continuously variable transmission side; In the hydraulic control device for a vehicle power transmission device including a hydraulic traveling friction engagement element that is engaged to establish a power transmission path at the time of supply to the driving pulley of the belt type continuously variable transmission A control valve for outputting the hydraulic pressure to be output, a first electromagnetic valve for controlling the output hydraulic pressure of the first control valve, a second electromagnetic valve for controlling the engagement pressure of the lock-up clutch, and the friction engagement element for traveling Hydraulic pressure to supply A third solenoid valve that switches according to the transitional transition state or the complete engagement state of the traveling frictional engagement element, and the hydraulic pressure supplied to the drive pulley is different from the output hydraulic pressure of the control valve and the output hydraulic pressure. A fail-safe valve that is switchable between hydraulic pressures, and the fail-safe valve is configured to drive the other hydraulic pressure on the drive side when a sudden deceleration state may occur in the belt-type continuously variable transmission. It is switched to the fail position to be supplied to the pulley, and at other normal times, it is switched to the normal position to supply the output hydraulic pressure of the control valve to the driving pulley, and this fail safe valve is switched by the control of the second electromagnetic valve. It is controlled by the hydraulic pressure and the control hydraulic pressure of the third electromagnetic valve.

  According to the above configuration, when there is a possibility that a sudden deceleration state may occur in the belt-type continuously variable transmission, the fail-safe valve is switched to the fail position, and is separated from the drive pulley of the belt-type continuously variable transmission. Therefore, the sudden deceleration state can be avoided. That is, the change of the gear ratio to the deceleration side can be suppressed by introducing the other hydraulic pressure to the driving pulley. In addition, belt slippage or overrev that occurs due to sudden deceleration can be prevented. And since the existing solenoid valve (a 2nd solenoid valve and a 3rd solenoid valve) is utilized for switching control of a fail safe valve, the cost increase and the enlargement of an apparatus can be avoided.

  In the present invention, the second electromagnetic valve is preferably a duty electromagnetic valve, and the third electromagnetic valve is preferably an ON-OFF electromagnetic valve. The fail-safe valve is configured to be switched to a fail position when the duty solenoid valve outputs a maximum pressure or a hydraulic pressure close to the maximum pressure and the ON-OFF solenoid valve is open. Preferably it is.

  Here, to switch the fail-safe valve, it may be considered to use an electromagnetic valve that controls the hydraulic pressure supplied to the driven pulley of the belt type continuously variable transmission. However, in this case, when the fail-safe valve is switched to the fail position, it is necessary to control the control hydraulic pressure of the electromagnetic valve to the maximum pressure or the hydraulic pressure near the maximum pressure. As a result, the belt clamping pressure increases, and the load on the belt may increase. On the other hand, according to the above configuration, the fail-safe valve is switched to the fail position because the solenoid valve that controls the hydraulic pressure supplied to the driven pulley of the belt type continuously variable transmission is not used to switch the fail-safe valve. At this time, it is not necessary to control the control hydraulic pressure of the solenoid valve to a hydraulic pressure near the maximum pressure. Therefore, it is possible to reduce the load on the belt in the belt type continuously variable transmission, and it is possible to improve the reliability during limp home.

  The present invention further includes a lockup control valve that operates in accordance with a control hydraulic pressure of the second electromagnetic valve during engagement / release control of the lockup clutch, and the lockup control valve includes the third electromagnetic valve. When the hydraulic pressure supplied to the traveling frictional engagement element by the valve is switched to the hydraulic pressure (engagement transient hydraulic pressure) corresponding to the engagement transient state of the traveling frictional engagement element, the control hydraulic pressure of the third electromagnetic valve is changed. It is preferable that the second solenoid valve is configured to be supplied to the side opposing the control hydraulic pressure. According to this configuration, at the time of the engagement transition in which the engagement transient hydraulic pressure is supplied to the traveling friction engagement element, the lockup clutch is forcibly introduced by introducing the control hydraulic pressure of the third electromagnetic valve to the lockup control valve. Released state. Thereby, even if the second solenoid valve fails in a state of outputting hydraulic pressure, the occurrence of engine stall can be prevented.

  Here, it is preferable that the other oil pressure is any one of the following oil pressures (1) to (4). That is, when there is a possibility that a sudden deceleration state may occur in the belt-type continuously variable transmission, it is preferable to supply any one of the following hydraulic pressures (1) to (4) to the driving pulley.

  (1) Line pressure to be a source pressure of the hydraulic pressure of each part, (2) Oil pressure supplied to the driven pulley of the belt type continuously variable transmission, (3) Source pressure of any one of the solenoid valves, (4) An engagement holding hydraulic pressure supplied to the traveling frictional engagement element in a fully engaged state of the traveling frictional engagement element.

  According to the present invention, by introducing a hydraulic pressure different from the output hydraulic pressure of the control valve to the drive pulley of the belt type continuously variable transmission, it is possible to suppress the change of the gear ratio to the deceleration side. In addition, belt slippage or overrev that occurs due to sudden deceleration can be prevented. And since the existing solenoid valve (a 2nd solenoid valve and a 3rd solenoid valve) is utilized for switching control of a fail safe valve, the cost increase and the enlargement of an apparatus can be avoided.

  The best mode for carrying out the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram of a vehicle according to an embodiment to which the present invention is applied.

  The vehicle illustrated in FIG. 1 is an FF (front engine / front drive) type vehicle, and is an engine (internal combustion engine) 1 that is a driving power source, a torque converter 2 as a fluid transmission device, a forward / reverse switching device 3, A belt type continuously variable transmission (CVT) 4, a reduction gear device 5, a differential gear device 6, and an ECU (Electronic Control Unit) 8 as a control device are provided.

  A crankshaft 11 as an output shaft of the engine 1 is connected to the torque converter 2, and the output of the engine 1 is transmitted from the torque converter 2 to the forward / reverse switching device 3, the belt type continuously variable transmission 4, and the reduction gear device. 5 is transmitted to the differential gear device 6 via 5 and distributed to the left and right drive wheels (not shown). In such a vehicle, the torque converter 2, the forward / reverse switching device 3, the belt type continuously variable transmission 4, and the like constitute a power transmission device.

  The engine 1 is a multi-cylinder gasoline engine, for example. The amount of intake air taken into the engine 1 is adjusted by an electronically controlled throttle valve 12. The throttle valve 12 can electronically control the throttle opening independently of the driver's accelerator pedal operation, and the opening (throttle opening) is detected by the throttle opening sensor 102. Further, the coolant temperature of the engine 1 is detected by a water temperature sensor 103.

  The throttle opening of the throttle valve 12 is driven and controlled by the ECU 8. Specifically, the optimum intake air amount (in accordance with the operating state of the engine 1 such as the engine speed Ne detected by the engine speed sensor 101 and the accelerator pedal depression amount (accelerator opening Acc) of the driver). The throttle opening of the throttle valve 12 is controlled so as to obtain a target intake air amount. More specifically, the actual throttle opening of the throttle valve 12 is detected using the throttle opening sensor 102, and the actual throttle opening coincides with the throttle opening (target throttle opening) at which the target intake air amount can be obtained. Thus, the throttle motor 13 of the throttle valve 12 is feedback-controlled.

  The torque converter 2 includes an input-side pump impeller 21, an output-side turbine runner 22, and a stator 23 that develops a torque amplification function. Fluid (fluid) is supplied between the pump impeller 21 and the turbine runner 22. Power transmission. The pump impeller 21 is connected to the crankshaft 11 of the engine 1. The turbine runner 22 is connected to the forward / reverse switching device 3 via the turbine shaft 27.

  The torque converter 2 is provided with a lockup clutch 24 that directly connects the input side and the output side of the torque converter 2. Specifically, the lockup clutch 24 controls the engagement pressure, and specifically, the differential pressure between the hydraulic pressure in the engagement side oil chamber 25 and the hydraulic pressure in the release side oil chamber 26 (lockup differential pressure). By controlling, full engagement / semi-engagement (engagement in a slip state) or release is performed.

  By completely engaging the lockup clutch 24, the pump impeller 21 and the turbine runner 22 rotate integrally. Further, by engaging the lockup clutch 24 in a predetermined slip state (half-engaged state), the turbine runner 22 rotates following the pump impeller 21 with a predetermined slip amount during driving. On the other hand, by setting the lockup differential pressure to be negative, the lockup clutch 24 is released.

  The torque converter 2 is provided with a mechanical oil pump (hydraulic pressure generating source) 7 that is connected to and driven by the pump impeller 21.

  The forward / reverse switching device 3 includes a double pinion type planetary gear mechanism 30, a forward clutch C1, and a reverse brake B1.

  The sun gear 31 of the planetary gear mechanism 30 is integrally connected to the turbine shaft 27 of the torque converter 2, and the carrier 33 is integrally connected to the input shaft 40 of the belt type continuously variable transmission 4. The carrier 33 and the sun gear 31 are selectively coupled via a forward clutch C1, and the ring gear 32 is selectively fixed to the housing via a reverse brake B1.

  The forward clutch C1 and the reverse brake B1 are hydraulic travel friction engagement elements that are engaged and released by a hydraulic control circuit 20 described later. When the forward clutch C1 is engaged and the reverse brake B1 is released, the forward / reverse switching device 3 is integrally rotated to establish (achieve) the forward power transmission path. Is transmitted to the belt type continuously variable transmission 4 side.

  On the other hand, when the reverse brake B1 is engaged and the forward clutch C1 is released, the forward / reverse switching device 3 establishes (achieves) a reverse power transmission path. In this state, the input shaft 40 rotates in the reverse direction with respect to the turbine shaft 27, and the driving force in the reverse direction is transmitted to the belt type continuously variable transmission 4 side. Further, when both the forward clutch C1 and the reverse brake B1 are released, the forward / reverse switching device 3 is in a neutral state (blocking state) for blocking power transmission.

  The belt-type continuously variable transmission 4 includes an input-side primary pulley 41, an output-side secondary pulley 42, and a metal belt 43 wound around the primary pulley 41 and the secondary pulley 42.

  The primary pulley 41 is a variable pulley having a variable effective diameter, and a fixed sheave 41a fixed to the input shaft 40 and a movable sheave 41b disposed on the input shaft 40 so as to be slidable only in the axial direction. It is constituted by. Similarly, the secondary pulley 42 is a variable pulley having a variable effective diameter, and a movable sheave 42a fixed to the output shaft 44 and a movable sheave arranged in the output shaft 44 so as to be slidable only in the axial direction. It is constituted by a sheave 42b.

  A hydraulic actuator 41c for changing the V groove width between the fixed sheave 41a and the movable sheave 41b is disposed on the movable sheave 41b side of the primary pulley 41. Similarly, a hydraulic actuator 42c for changing the V-groove width between the fixed sheave 42a and the movable sheave 42b is also arranged on the movable sheave 42b side of the secondary pulley 42.

  In such a belt type continuously variable transmission 4, by controlling the hydraulic pressure (speed change hydraulic pressure) of the hydraulic actuator 41 c of the primary pulley 41, the V groove widths of the primary pulley 41 and the secondary pulley 42 change and the belt 43 is engaged. The diameter (effective diameter) is changed, and the gear ratio γ (= primary pulley rotational speed (input shaft rotational speed) Nin / secondary pulley rotational speed (output shaft rotational speed) Nout) continuously changes. The hydraulic pressure (clamping hydraulic pressure) of the hydraulic actuator 42c of the secondary pulley 42 is controlled so that the belt 43 is clamped with a predetermined clamping pressure that does not cause belt slip. These controls are executed by the ECU 8 and the hydraulic control circuit 20.

  As shown in FIG. 1, the hydraulic control circuit 20 controls the hydraulic pressure of the hydraulic pressure control unit 20 a that controls the hydraulic pressure of the hydraulic actuator 41 c of the primary pulley 41 of the belt-type continuously variable transmission 4 and the hydraulic pressure of the hydraulic actuator 42 c of the secondary pulley 42. A clamping pressure hydraulic control unit 20b, a line pressure control unit 20c that controls a line pressure PL that is a source pressure (control source pressure) of each part, and a lockup clutch control unit that controls engagement / release of the lockup clutch 24. 20d, a garage control unit 20e that controls engagement / release of the travel friction engagement elements (forward clutch C1, reverse brake B1), and rapid deceleration that prevents the sudden deceleration state from occurring in the belt-type continuously variable transmission 4 The prevention part 20f and the manual valve 20g are comprised. For switching the supply hydraulic pressure of a linear solenoid (SLP) 201, a linear solenoid (SLS) 202, a duty solenoid (DSU) 203 for controlling lock-up engagement pressure, and a friction engagement element for travel, which constitute the hydraulic control circuit 20 A control signal from the ECU 8 is supplied to the ON-OFF solenoid (SL) 204.

  Next, the ECU 8 will be described with reference to FIG. As shown in FIG. 2, the ECU 8 includes a CPU 81, a ROM 82, a RAM 83, a backup RAM 84, and the like.

  The ROM 82 stores various control programs, maps that are referred to when the various control programs are executed, and the like. The CPU 81 executes arithmetic processing based on various control programs and maps stored in the ROM 82. The RAM 83 is a memory that temporarily stores the calculation results of the CPU 81, data input from each sensor, and the like. The backup RAM 84 is a nonvolatile memory that stores data to be saved when the engine 1 is stopped. Sex memory.

  The CPU 81, ROM 82, RAM 83, and backup RAM 84 are connected to each other via a bidirectional bus 87 and are connected to an input interface 85 and an output interface 86.

  Various sensors are connected to the input interface 85 in order to detect the operation state (or running state) of the vehicle. Specifically, the input interface 85 includes an engine speed sensor 101, a throttle opening sensor 102, a water temperature sensor 103, a turbine speed sensor 104, a primary pulley speed sensor 105, a secondary pulley speed sensor 106, an accelerator position sensor. 107, a CVT oil temperature sensor 108, a brake pedal sensor 109, and a lever position sensor 110 for detecting a lever position (operation position) of the shift lever 9 are connected. Then, the output signals of the various sensors, that is, the engine speed (engine speed) Ne, the throttle opening degree θth of the throttle valve 12, the cooling water temperature Tw of the engine 1, the rotational speed of the turbine shaft 27 are sent to the ECU 8. (Turbine rotational speed) Nt, primary pulley rotational speed (input shaft rotational speed) Nin, secondary pulley rotational speed (output shaft rotational speed) Nout, accelerator pedal operation amount (accelerator function) Acc, oil temperature of hydraulic control circuit 20 (CVT oil temperature Thc), presence / absence of operation of a foot brake as a service brake (brake ON / OFF), and a signal indicating a lever position (operation position) of the shift lever 9 are supplied.

  To the output interface 86, the throttle motor 13, the fuel injection device 14, the ignition device 15, and the hydraulic control circuit 20 are connected.

  Here, among the signals supplied to the ECU 8, the turbine rotational speed Nt coincides with the primary pulley rotational speed (input shaft rotational speed) Nin during forward travel in which the forward clutch C1 of the forward / reverse switching device 3 is engaged. The secondary pulley rotational speed (output shaft rotational speed) Nout corresponds to the vehicle speed V. Further, the accelerator opening Acc represents the driver's required output amount.

  The shift lever 9 includes a parking position “P” for parking, a reverse position “R” for reverse traveling, a neutral position “N” for interrupting power transmission, a drive position “D” for forward traveling, When traveling forward in so-called manual mode, the belt-type continuously variable transmission 4 is selectively operated at various positions such as a manual position “M” for increasing or decreasing the gear ratio γ of the belt-type continuously variable transmission 4 by manual operation. . The manual position “M” includes a plurality of ranges in which a downshift position and an upshift position for increasing / decreasing the speed ratio γ, or a plurality of speed ranges in which the upper limit of the speed range (the side where the speed ratio γ is smaller) are different can be selected. Position etc. are provided. The lever position sensor 110 is, for example, a parking position “P”, a reverse position “R”, a neutral position “N”, a drive position “D”, a manual position “M”, an upshift position, a downshift position, or a range position. A plurality of ON / OFF switches for detecting that the shift lever 9 is operated are provided.

  The ECU 8 controls the output of the engine 1, the supply hydraulic pressure (hydraulic pressure) of the hydraulic actuator 41 c of the primary pulley 41 of the belt type continuously variable transmission 4, and the secondary pulley 42 based on the output signals of the various sensors. Control of supply hydraulic pressure (clamping hydraulic pressure) of hydraulic actuator 42c, control of control of line pressure PL, engagement / release control of travel friction engagement elements (forward clutch C1, reverse brake B1), lock-up Various controls such as engagement / release control of the clutch 24 are executed.

  Next, portions of the hydraulic control circuit 20 related to the transmission hydraulic control unit 20a, the clamping hydraulic control unit 20b, the line pressure control unit 20c, the lockup clutch control unit 20d, the garage control unit 20e, and the sudden deceleration prevention unit 20f. Will be described with reference to FIG. The hydraulic control circuit shown in FIG. 3 is a part of the entire hydraulic control circuit 20.

  The hydraulic control circuit shown in FIG. 3 includes an oil pump 7, a manual valve 20g, a linear solenoid (SLP) 201, a linear solenoid (SLS) 202, a duty solenoid (DSU) 203, an ON-OFF solenoid (SL) 204, and a primary regulator valve. 205, first modulator valve 206, second modulator valve 207, select reducing valve 208, transmission hydraulic pressure control valve 301, clamping hydraulic pressure control valve 303, fail safe valve 305, clutch apply control valve 401, clutch pressure control valve 403 The lockup control valve 405 is included.

  As shown in FIG. 3, the hydraulic pressure generated by the oil pump 7 is regulated by the primary regulator valve 205 to generate the line pressure PL. The primary regulator valve 205 is provided with a spool 251 that is movable in the axial direction. A spring 252 is disposed in a compressed state on one end side (the lower end side in FIG. 3) of the spool 251 and a control hydraulic pressure port 255 is formed on one end side thereof. A select reducing valve 208 described later is connected to the control oil pressure port 255, and the oil pressure output from the select reducing valve 208 is applied to the control oil pressure port 255.

  The primary regulator valve 205 operates using the output oil pressure of the select reducing valve 208 as a pilot pressure to regulate the line pressure PL. The line pressure PL adjusted by the primary regulator valve 205 is supplied to the transmission hydraulic pressure control valve 301, the clamping hydraulic pressure control valve 303, and the first modulator valve 206.

  The first modulator valve 206 is a pressure regulating valve that regulates the line pressure PL regulated by the primary regulator valve 205 to a constant hydraulic pressure (first modulator hydraulic pressure PM1) lower than that. The first modulator hydraulic pressure PM1 output from the first modulator valve 206 is supplied to the linear solenoid (SLP) 201, the linear solenoid (SLS) 202, the second modulator valve 207, the select reducing valve 208, and the clutch pressure control valve 403. The manual valve 20g is supplied via the clutch apply control valve 401.

  The second modulator valve 207 is a pressure regulating valve that regulates the first modulator hydraulic pressure PM1 regulated by the first modulator valve 206 to a constant hydraulic pressure (second modulator hydraulic pressure PM2) lower than that. The second modulator hydraulic pressure PM2 output from the second modulator valve 207 is supplied to a duty solenoid (DSU) 203 and an ON-OFF solenoid (SL) 204.

  The linear solenoid (SLP) 201 and the linear solenoid (SLS) 202 are normally open type solenoid valves. The linear solenoid (SLP) 201 and the linear solenoid (SLS) 202 output a control hydraulic pressure (output hydraulic pressure) according to a current value determined by a duty signal (duty value) transmitted from the ECU 8. The control hydraulic pressure output from the linear solenoid (SLP) 201 is supplied to the transmission hydraulic pressure control valve 301. The control hydraulic pressure output from the linear solenoid (SLS) 202 is supplied to the clamping hydraulic pressure control valve 303, the select reducing valve 208, and the clutch pressure control valve 403. The linear solenoid (SLP) 201 and the linear solenoid (SLS) 202 may be normally closed solenoid valves.

  The duty solenoid (DSU) 203 is a normally closed type solenoid valve. The duty solenoid (DSU) 203 outputs a control hydraulic pressure (output hydraulic pressure) according to a current value determined by a duty signal (duty value) transmitted from the ECU 8. The control hydraulic pressure output from the duty solenoid (DSU) 203 is supplied to the lockup control valve 405, the clutch apply control valve 401, and the fail safe valve 305. The duty solenoid (DSU) 203 may be a normally open type solenoid valve.

  The ON-OFF solenoid (SL) 204 is a normally closed type solenoid valve. The ON-OFF solenoid (SL) 204 is configured to be switched to a closed state where no control hydraulic pressure is output when not energized, and to an open state where the control hydraulic pressure is output when energized. The control hydraulic pressure output from the ON-OFF solenoid (SL) 204 is supplied to the clutch apply control valve 401, the lockup control valve 405, and the fail safe valve 305. The ON-OFF solenoid (SL) 204 may be a normally open type solenoid valve.

  The select reducing valve 208 adjusts a pilot pressure for adjusting the line pressure PL and supplies the pilot pressure to the primary regulator valve 205. The select reducing valve 208 is provided with a first spool 281 and a second spool 282 that are movable in the axial direction side by side along the axial direction. A spring 283 is disposed in a compressed state on one end side (the lower end side in FIG. 3) of the lower second spool 282, and an end opposite to the spring 283 across the first spool 281 and the second spool 282. A first control hydraulic port 284 is formed in the part. An output port 363 of the fail safe valve 305 is connected (communication) to the first control hydraulic pressure port 284.

  When the fail safe valve 305 is held at the normal position shown in the left half of FIG. 3, the output hydraulic pressure of the transmission hydraulic pressure control valve 301 described later is applied to the first control hydraulic pressure port 284. When the fail safe valve 305 is held at the fail position shown in the right half of FIG. 3, the output hydraulic pressure of the clamping hydraulic pressure control valve 303 described later is applied to the first control hydraulic pressure port 284. Although details of the failsafe valve 305 will be described later, it is assumed here that the failsafe valve 305 is held in the normal position shown in the left half of FIG.

  The select reducing valve 208 is formed with a second control hydraulic pressure port 285 so that hydraulic pressure is supplied to the space between the first spool 281 and the second spool 282. A linear solenoid (SLS) 202 is connected to the second control hydraulic pressure port 285, and the control hydraulic pressure output from the linear solenoid (SLS) 202 is applied to the second control hydraulic pressure port 285.

  Further, the select reducing valve 208 is formed with a feedback port 287 at an end on one end side where the spring 283 is disposed. Further, the select reducing valve 208 is formed with an input port 288 connected to the first modulator valve 206 and an output port 289 connected (communication) to the control hydraulic pressure port 255 of the primary regulator valve 205.

  The select reducing valve 208 pilots the output hydraulic pressure of the transmission hydraulic pressure control valve 301 introduced from the first control hydraulic pressure port 284 and the control hydraulic pressure of the linear solenoid (SLS) 202 introduced from the second control hydraulic pressure port 285. Acts as a pressure.

  Here, in adjusting the output oil pressure of the select reducing valve 208, the force acting on the first spool 281 of the output oil pressure of the transmission oil pressure control valve 301 and the control oil pressure of the linear solenoid (SLS) 202 are applied to the second spool 28. Of the forces that act, the larger force contributes. Specifically, when the force acting on the first spool 281 of the output hydraulic pressure of the transmission hydraulic pressure control valve 301 is large, the first spool 281 and the second spool 282 are in contact with each other as shown in the right half of FIG. Move up and down together. Then, the output oil pressure from the output port 289 is adjusted according to the output oil pressure of the transmission oil pressure control valve 301.

  On the other hand, when the force acting on the second spool 282 of the control hydraulic pressure of the linear solenoid (SLS) 202 is large, the first spool 281 is moved up and down with the first spool 281 spaced from the second spool 282 as shown in the left half of FIG. Move to. Then, the output hydraulic pressure from the output port 289 is adjusted according to the control hydraulic pressure of the linear solenoid (SLS) 202.

  As shown in FIG. 3, a transmission hydraulic pressure control valve 301 is connected to the hydraulic actuator 41 c of the primary pulley 41 of the belt type continuously variable transmission 4 via a fail safe valve 305. Although details of the failsafe valve 305 will be described later, it is assumed here that the failsafe valve 305 is held in the normal position shown in the left half of FIG.

  The transmission hydraulic pressure control valve 301 is provided with a spool 311 that is movable in the axial direction. A spring 312 is disposed in a compressed state on one end side (the lower end side in FIG. 3) of the spool 311 and a control hydraulic pressure port 315 is formed on one end side thereof. A linear solenoid (SLP) 201 is connected to the control hydraulic pressure port 315, and the control hydraulic pressure output from the linear solenoid (SLP) 201 is applied to the control hydraulic pressure port 315.

  The transmission hydraulic pressure control valve 301 has an input port 313 to which the line pressure PL is supplied, and an output connected to the hydraulic actuator 41c of the primary pulley 41 and the select reducing valve 208 via the fail safe valve 305. A port 314 is formed.

  The transmission hydraulic pressure control valve 301 regulates the line pressure PL using the control hydraulic pressure output from the linear solenoid (SLP) 201 as a pilot pressure, and supplies it to the hydraulic actuator 41 c of the primary pulley 41 and the select reducing valve 208. As a result, the hydraulic pressure supplied to the hydraulic actuator 41c of the primary pulley 41 is controlled, and the gear ratio γ of the belt-type continuously variable transmission 4 is controlled.

  Specifically, when the control hydraulic pressure output from the linear solenoid (SLP) 201 is increased from the state where a predetermined hydraulic pressure is supplied to the hydraulic actuator 41c of the primary pulley 41, the spool 311 moves to the upper side in FIG. As a result, the hydraulic pressure supplied to the hydraulic actuator 41c of the primary pulley 41 increases, the V groove width of the primary pulley 41 becomes narrower, and the speed ratio γ becomes smaller (upshift).

  On the other hand, when the control hydraulic pressure output from the linear solenoid (SLP) 201 decreases from the state where a predetermined hydraulic pressure is supplied to the hydraulic actuator 41c of the primary pulley 41, the spool 311 moves downward in FIG. As a result, the hydraulic pressure supplied to the hydraulic actuator 41c of the primary pulley 41 decreases, the V groove width of the primary pulley 41 becomes wider, and the gear ratio γ increases (downshift).

  In this case, for example, the target input shaft rotational speed set based on the vehicle state indicated by the actual vehicle speed V and the accelerator opening Acc from the shift map stored in advance in the ROM 82 of the ECU 8 and the actual input shaft rotational speed Nin. Is matched with the rotational speed difference (deviation) of the belt type continuously variable transmission 4. The shift map indicates a shift condition, and is, for example, the relationship between the vehicle speed V and the target input shaft rotation speed that is the target input rotation speed of the belt-type continuously variable transmission 4 with the accelerator opening Acc as a parameter.

  As shown in FIG. 3, a clamping hydraulic pressure control valve 303 is connected to the hydraulic actuator 42 c of the secondary pulley 42 of the belt type continuously variable transmission 4. The clamping hydraulic pressure control valve 303 has the same configuration as the above-described transmission hydraulic pressure control valve 301, and detailed description thereof is omitted.

  A linear solenoid (SLS) 202 is connected to the control hydraulic pressure port 335 of the clamping hydraulic pressure control valve 303, and the control hydraulic pressure output from the linear solenoid (SLS) 202 is applied to the control hydraulic pressure port 335. The clamping hydraulic pressure control valve 303 adjusts the line pressure PL using the control hydraulic pressure output from the linear solenoid (SLS) 202 as a pilot pressure, and supplies it to the hydraulic actuator 42 c of the secondary pulley 42. Thereby, the hydraulic pressure supplied to the hydraulic actuator 42c of the secondary pulley 42 is controlled, and the belt clamping pressure of the belt type continuously variable transmission 4 is controlled.

  Specifically, when the control hydraulic pressure output from the linear solenoid (SLS) 202 increases from the state where a predetermined hydraulic pressure is supplied to the hydraulic actuator 42c of the secondary pulley 42, the spool 331 moves upward in FIG. Thereby, the hydraulic pressure supplied to the hydraulic actuator 42c of the secondary pulley 42 increases, and the belt clamping pressure increases.

  On the other hand, when the control hydraulic pressure output from the linear solenoid (SLS) 202 decreases from the state in which the predetermined hydraulic pressure is supplied to the hydraulic actuator 42c of the secondary pulley 42, the spool 331 moves downward in FIG. Thereby, the hydraulic pressure supplied to the hydraulic actuator 42c of the secondary pulley 42 decreases, and the belt clamping pressure decreases.

  In this case, for example, the secondary pressure is obtained so that a necessary target clamping pressure set based on the vehicle state indicated by the actual gear ratio γ and the accelerator opening Acc is obtained from the clamping pressure map stored in advance in the ROM 82 of the ECU 8. The clamping hydraulic pressure of the hydraulic actuator 42c of the pulley 42 is adjusted, and the belt clamping pressure of the belt type continuously variable transmission 4 is changed according to the clamping hydraulic pressure. The sandwiching pressure map is a relationship between the speed ratio γ and the required target sandwiching hydraulic pressure with the accelerator opening Acc as a parameter, and is a relationship obtained experimentally in advance so that belt slip does not occur.

  When the fail safe valve 305 is switched to the fail position shown in the right half of FIG. 3, the output hydraulic pressure of the clamping hydraulic pressure control valve 303 is also supplied to the hydraulic actuator 41c of the primary pulley 41. The point will be described later.

  As shown in FIG. 3, a manual valve 20g is connected to each of the hydraulic servos 3C, 3B of the forward clutch C1 and the reverse brake B1 of the forward / reverse switching device 3.

  The manual valve 20g is a switching valve that switches the hydraulic pressure supply to the hydraulic servos 3C and 3B of the forward clutch C1 and the reverse brake B1 of the forward / reverse switching device 3 according to the operation of the shift lever 9. The manual valve 20g is switched corresponding to each shift position such as the parking position "P", the reverse position "R", the neutral position "N", the drive position "D", etc. of the shift lever 9.

  When the manual valve 20g is switched corresponding to the parking position “P” and the neutral position “N” of the shift lever 9, the hydraulic servo 3C of the forward clutch C1 and the hydraulic servo 3B of the reverse brake B1 are hydraulically Is not supplied. The hydraulic pressures of the hydraulic servos 3C and 3B of the forward clutch C1 and the reverse brake B1 are drained through the manual valve 20g. As a result, both the forward clutch C1 and the reverse brake B1 are released.

  When the manual valve 20g is switched corresponding to the reverse position “R” of the shift lever 9, the input port 211 and the output port 213 are communicated, and the hydraulic pressure is supplied to the hydraulic servo 3B of the reverse brake B1. On the other hand, the hydraulic pressure of the hydraulic servo 3C of the forward clutch C1 is drained through the manual valve 20g. As a result, the reverse brake B1 is engaged and the forward clutch C1 is released.

  When the manual valve 20g is switched corresponding to the drive position “D” of the shift lever 9, the input port 211 and the output port 212 are communicated, and the hydraulic pressure is supplied to the hydraulic servo 3C of the forward clutch C1. On the other hand, the hydraulic pressure of the hydraulic servo 3B of the reverse brake B1 is drained through the manual valve 20g. As a result, the forward clutch C1 is engaged and the reverse brake B1 is released.

  As shown in FIG. 3, a clutch apply control valve 401, which is a friction engagement element supply hydraulic pressure switching valve, is connected to the manual valve 20g.

  The clutch apply control valve 401 supplies the hydraulic pressure supplied to the travel friction engagement elements (forward clutch C1 and reverse brake B1) of the forward / reverse switching device 3 to the engagement transient state (engagement of the travel friction engagement elements). This is a switching valve that can be switched between a transition state and a completely engaged state (when engaged). For example, when the shift lever 9 is operated from a non-travel position such as a parking position “P” or a neutral position “N” to a travel position such as a drive position “D” when the vehicle starts, etc., the clutch apply control valve By switching 401, the hydraulic pressure supplied to the hydraulic servo 3C of the forward clutch C1 via the above-described manual valve 20g is changed to the engagement transient hydraulic pressure corresponding to the engagement transition and the engagement holding hydraulic pressure corresponding to the complete engagement. Can be switched between.

  Similarly, when the shift lever 9 is operated to the reverse position “R”, the hydraulic pressure supplied to the hydraulic servo 3B of the reverse brake B1 via the manual valve 20g by switching the clutch apply control valve 401. Is switched between the engagement transient oil pressure corresponding to the engagement transition and the engagement holding oil pressure corresponding to the complete engagement. Hereinafter, a case where the hydraulic pressure supplied to the forward clutch C1 is switched by the clutch apply control valve 401 will be described as a representative, and a description of a case where the hydraulic pressure supplied to the reverse clutch B1 is switched will be omitted.

  The clutch apply control valve 401 is switched to the engagement transition position shown in the left half of FIG. 3 when the forward clutch C1 is engaged, and when the forward clutch C1 is engaged (completely engaged), 3 is configured to be switched to the engagement position shown in the right half of FIG.

  Specifically, the clutch apply control valve 401 is provided with a spool 411 that is movable in the axial direction. A spring 412 is arranged in a compressed state on one end side (the lower end side in FIG. 3) of the spool 411, and a control hydraulic pressure port 415 is formed at an end opposite to the spring 412 across the spool 411. Yes. A drain port 416 is formed on the one end where the spring 412 is disposed. An ON-OFF solenoid (SL) 204 is connected to the control hydraulic pressure port 415, and a control hydraulic pressure output from the ON-OFF solenoid (SL) 204 is applied to the control hydraulic pressure port 415.

  The clutch apply control valve 401 has input ports 421 and 422 and an output port 423. The input port 421 is connected to the first modulator valve 206. The input port 422 is connected (communication) to the output port 434 of the clutch pressure control valve 403. The output port 423 is connected (communication) to the input port 211 of the manual valve 20g.

  The clutch apply control valve 401 is switched by an ON-OFF solenoid (SL) 204. Specifically, when the ON-OFF solenoid (SL) 204 is in the closed state, the clutch apply control valve 401 is held at the engaged position where the spring 412 is in the attached state. At this time, the input port 421 and the output port 423 communicate with each other. Due to the communication between the input port 421 and the output port 423, the first modulator hydraulic pressure PM1 regulated by the first modulator valve 206 is supplied to the hydraulic servo 3C of the forward clutch C1.

  On the other hand, when the ON-OFF solenoid (SL) 204 is in the open state, the clutch apply control valve 401 is switched to the engagement transition position where the spring 412 is compressed. At this time, the input port 422 and the output port 423 communicate with each other. Due to the communication between the input port 422 and the output port 423, the hydraulic pressure adjusted by the clutch pressure control valve 403 is supplied to the hydraulic servo 3C of the forward clutch C1.

  As shown in FIG. 3, a clutch pressure control valve 403 is connected to the clutch apply control valve 401.

  The clutch pressure control valve 403 is a pressure regulating valve that regulates the engagement transient hydraulic pressure to the forward clutch C1 using the control hydraulic pressure output from the linear solenoid (SLS) 202 as a pilot pressure.

  The clutch pressure control valve 403 is provided with a spool 431 that is movable in the axial direction. A spring 432 is disposed in a compressed state on one end side (the upper end side in FIG. 3) of the spool 431, and a control hydraulic pressure port 435 is formed at the end opposite to the spring 432 across the spool 431. ing. A linear solenoid (SLS) 202 is connected to the control hydraulic pressure port 435, and the control hydraulic pressure output from the linear solenoid (SLS) 202 is applied to the control hydraulic pressure port 435.

  The clutch pressure control valve 403 is connected (communication) to an input port 433 to which the first modulator hydraulic pressure PM1 regulated by the first modulator valve 206 is supplied, and to an input port 422 of the clutch apply control valve 401. An output port 434 is formed.

  When the clutch apply control valve 401 is switched to the engagement transition position, the hydraulic pressure output from the output port 434 of the clutch pressure control valve 403 is transferred to the hydraulic servo 3C of the forward clutch C1 via the manual valve 20g. Supplied. In this way, the hydraulic pressure (engagement transient hydraulic pressure) supplied to the forward clutch C1 when the forward clutch C1 is engaged is controlled by the clutch pressure control valve 403.

  In this case, when the control hydraulic pressure output from the linear solenoid (SLS) 202 increases, the spool 431 moves upward in FIG. 3 against the elastic force of the spring 432. As a result, the hydraulic pressure output from the output port 434 increases and the engagement transient hydraulic pressure supplied to the forward clutch C1 increases. On the other hand, when the control hydraulic pressure output by the linear solenoid (SLS) 202 decreases, the spool 431 moves downward in FIG. 3 by the elastic force of the spring 432. As a result, the hydraulic pressure output from the output port 434 decreases, and the engagement transient hydraulic pressure supplied to the forward clutch C1 decreases.

  As shown in FIG. 3, a lockup control valve 405 is connected to the engagement side oil chamber 25 and the release side oil chamber 26 of the lockup clutch 24.

  The lockup control valve 405 controls engagement / release of the lockup clutch 24. Specifically, the lockup control valve 405 controls the engagement / release of the lockup clutch 24 by controlling the lockup differential pressure (= the hydraulic pressure of the engagement side oil chamber 25−the hydraulic pressure of the release side oil chamber 26). Is configured to control.

  The lockup control valve 405 is provided with a spool 451 that is movable in the axial direction. A spring 452 is arranged in a compressed state on one end side (the lower end side in FIG. 3) of the spool 451, and a control hydraulic pressure port 455 is formed at the end opposite to the spring 452 across the spool 451. Yes. Further, a backup port 456 and a feedback port 457 are formed on one end side where the spring 452 is disposed. A duty solenoid (DSU) 203 is connected to the control hydraulic pressure port 455, and a control hydraulic pressure output from the duty solenoid (DSU) 203 is applied to the control hydraulic pressure port 455. The lock-up control valve 405 is formed with input ports 461 and 462, an output port 465, input / output ports 463 and 464, and a drain port 466.

  The input ports 461 and 462 are connected to secondary regulator valves (not shown) connected to the primary regulator valve 205, respectively. The secondary hydraulic pressure PSEC regulated by the secondary regulator valve is inputted from the input ports 461 and 462.

  The input / output port 463 is connected (communication) to the engagement side oil chamber 25 of the lockup clutch 24. The input / output port 464 is connected (communication) to the release-side oil chamber 26 of the lockup clutch 24. The backup port 456 is connected to the above-described ON-OFF solenoid (SL) 204.

  Engagement / release control of the lockup clutch 24 by the lockup control valve 405 is performed as follows.

  When the control hydraulic pressure of the duty solenoid (DSU) 203 is introduced into the control hydraulic pressure port 455, the lock-up control valve 405 is in a state where the spool 451 moves downward against the elastic force of the spring 452 according to the control hydraulic pressure. (ON state). In this case, the higher the control hydraulic pressure, the lower the spool 451 moves. The right half of FIG. 3 shows a state where the spool 451 has moved downward as much as possible. In the state shown in the right half of FIG. 3, the input port 461 and the input / output port 463, and the input / output port 464 and the drain port 466 are communicated with each other. At this time, the lock-up clutch 24 is completely engaged.

  When the lock-up control valve 405 is in the ON state, the spool 451 has a control hydraulic pressure of the duty solenoid (DSU) 203 introduced into the control hydraulic pressure port 455 and a hydraulic pressure introduced into the input / output port 464 (hydraulic pressure of the release side oil chamber 26). ) And the combined force of the hydraulic force introduced into the feedback port 457 (the hydraulic pressure of the engagement side oil chamber 25) and the combined force of the elastic force of the spring 452 up and down. To slide. Here, the lockup clutch 24 is controlled to be engaged / released in accordance with the lockup differential pressure. The lockup differential pressure is controlled by controlling the control hydraulic pressure of the duty solenoid (DSU) 203, and the degree of engagement (clutch capacity) of the lockup clutch 24 is continuously changed in accordance with the lockup differential pressure. It is possible to make it.

  More specifically, as the control hydraulic pressure of the duty solenoid (DSU) 203 is increased, the lockup differential pressure increases and the degree of engagement of the lockup clutch 24 increases. In this case, hydraulic oil from the secondary regulator valve is supplied to the engagement side oil chamber 25 of the lockup clutch 24 via the input port 461 and the input / output port 463. On the other hand, the hydraulic oil in the release side oil chamber 26 is discharged through the input / output port 464 and the drain port 466. When the lockup differential pressure becomes a predetermined value or more, the lockup clutch 24 reaches the above-described complete engagement.

  Conversely, the lower the control hydraulic pressure of the duty solenoid (DSU) 203, the smaller the lockup differential pressure and the smaller the degree of engagement of the lockup clutch 24. In this case, hydraulic oil from the secondary regulator valve is supplied to the release side oil chamber 26 via the input port 462 and the input / output port 464. On the other hand, the hydraulic oil in the engagement side oil chamber 25 is discharged through the input / output port 463 and the output port 465. When the lockup differential pressure becomes a negative value, the lockup clutch 24 is released.

  Then, when the supply of the control hydraulic pressure of the duty solenoid (DSU) 203 to the control hydraulic pressure port 455 is stopped, the lock-up control valve 405 moves the spool 451 upward as shown in the left half of FIG. The spring 452 is held at a position in the attached state (OFF state). In this OFF state, the input port 462 and the input / output port 464, and the input / output port 463 and the output port 465 are communicated with each other. At this time, the lockup clutch 24 is in a released state.

  When the above-described ON-OFF solenoid (SL) 204 is in an open state, the control hydraulic pressure is introduced into the backup port 456. That is, in the lock-up control valve 405, the control hydraulic pressure of the ON-OFF solenoid (SL) 204 is supplied to the side opposite to the control hydraulic pressure of the duty solenoid (DSU) 203. As a result, the engagement / release control of the lockup clutch 24 as described above is not performed, and the control for forcibly releasing the lockup clutch 24 is performed.

  Next, the fail safe valve 305 will be described.

  The fail safe valve 305 is interposed between the hydraulic actuator 41 c of the primary pulley 41 of the belt type continuously variable transmission 4 and the transmission hydraulic control valve 301. Specifically, the fail-safe valve 305 is a hydraulic pressure supplied to the hydraulic actuator 41c of the primary pulley 41 depending on whether or not a sudden deceleration state may occur in the belt-type continuously variable transmission 4. This is a switching valve that switches between the two. The fail-safe valve 305 is switched to the fail position shown in the right half of FIG. 3 when there is a possibility of sudden deceleration in the belt-type continuously variable transmission 4, and at normal times when there is no such possibility. , And the normal position shown in the left half of FIG.

  The fail safe valve 305 is provided with a spool 351 that is movable in the axial direction. A spring 352 is arranged in a compressed state on one end side (the lower end side in FIG. 3) of the spool 351, and the first control hydraulic port 355 and the first control port 355 are disposed at the end opposite to the spring 352 across the spool 351. A two-control hydraulic port 356 is formed. A drain port 357 is formed on the one end side where the spring 352 is disposed.

  An ON-OFF solenoid (SL) 204 is connected to the first control hydraulic pressure port 355, and a control hydraulic pressure PSL output from the ON-OFF solenoid (SL) 204 is applied to the first control hydraulic pressure port 355. The control hydraulic pressure PSL of the ON-OFF solenoid (SL) 204 acts on the spool 351 in the direction opposite to the direction of the elastic force of the spring 352 only in the open state (when energized), and in the closed state (non- When it is energized, it does not work.

  A duty solenoid (DSU) 203 is connected to the second control hydraulic pressure port 356, and a control hydraulic pressure PDSU output from the duty solenoid (DSU) 203 is applied to the second control hydraulic pressure port 356. The control hydraulic pressure PDSU of the duty solenoid (DSU) 203 acts on the spool 351 in a direction opposite to the direction in which the elastic force of the spring 352 acts. More specifically, the working area (pressure receiving area) acting on the spool 351 of the control hydraulic pressure PDSU of the duty solenoid (DSU) 203 is the working area acting upward and the working area acting downward. The action area acting downward is set larger. That is, the operating area in the direction opposite to the elastic force of the spring 352 is set larger than the operating area of the control hydraulic pressure PDSU of the duty solenoid (DSU) 203 in the same direction as the elastic force of the spring 352. ing. Therefore, the control hydraulic pressure PDSU of the duty solenoid (DSU) 203 acts on the spool 351 in the same direction as the control hydraulic pressure PSL of the ON-OFF solenoid (SL) 204.

  Further, the fail safe valve 305 is formed with input ports 361 and 362 and an output port 363. The input port 361 is connected (communication) to the output port 314 of the transmission hydraulic pressure control valve 301 described above, and the output hydraulic pressure of the transmission hydraulic pressure control valve 301 is introduced from the input port 361. The input port 362 is connected (communicated) to the output port 334 of the above-described sandwiching hydraulic control valve 303, and the output hydraulic pressure of the sandwiching hydraulic control valve 303 is introduced from this input port 362. . The output port 363 is connected to the hydraulic actuator 41 c of the primary pulley 41. Further, the output port 363 is connected to the first control hydraulic pressure port 284 of the select reducing valve 208 as described above.

  When the fail safe valve 305 is held at the normal position shown in the left half of FIG. 3, the input port 361 and the output port 363 communicate with each other. As a result, the output hydraulic pressure of the transmission hydraulic pressure control valve 301 is supplied to the hydraulic actuator 41 c of the primary pulley 41 and the select reducing valve 208. On the other hand, when the fail safe valve 305 is held at the fail position shown in the right half of FIG. 3, the input port 362 and the output port 363 communicate with each other. As a result, the output hydraulic pressure of the clamping hydraulic pressure control valve 303 is supplied to the hydraulic actuator 41 c of the primary pulley 41 and the select reducing valve 208.

  In this embodiment, the switching between the normal position and the fail position of the fail safe valve 305 is controlled by a combination of control oil pressures of two or more existing solenoid valves. Specifically, the fail-safe valve 305 is switched by the control hydraulic pressure PSL of the ON-OFF solenoid (SL) 204 for controlling the supply hydraulic pressure of the friction engagement element for traveling and the duty solenoid for controlling the lock-up engagement pressure. (DSU) 203 is controlled in combination with the control hydraulic pressure PDSU. Hereinafter, switching control of the failsafe valve 305 will be described.

  The fail-safe valve 305 is in a fail position when the ON-OFF solenoid (SL) 204 is in an open state in which the control hydraulic pressure PSL is output and the control hydraulic pressure PDSU of the duty solenoid (DSU) 203 is a maximum pressure or a hydraulic pressure near the maximum pressure. Otherwise, it is switched to the normal position. That is, the fail safe valve 305 is switched to the fail position when the resultant force acting on the spools 351 of the two control hydraulic pressures PSL and PDSU is larger than the elastic force of the spring 352, and when the resultant force is equal to or less than the elastic force of the spring 352. To the fail position.

  In other words, the fail-safe valve 305 is switched from the normal position to the fail position when the resultant force exceeds a preset specified value, and is switched from the fail position to the normal position when the resultant force falls below the specified value. With this switching operation, the hydraulic pressure supplied to the hydraulic actuator 41 c of the primary pulley 41 is changed between the output hydraulic pressure of the transmission hydraulic pressure control valve 301 and the output hydraulic pressure of the clamping hydraulic pressure control valve 303. ing.

  Specifically, with respect to the control hydraulic pressure PDSU of the duty solenoid (DSU) 203, the maximum pressure and the area near the maximum pressure are set as the use area at the time of failure. In this case, the use area at the time of failure is an area where the lockup clutch 24 is kept in the fully engaged state when the control hydraulic pressure PDSU of the duty solenoid (DSU) 203 is controlled to the oil pressure of the use area at the time of failure. Set as

  The ECU 8 controls the ON-OFF solenoid (SL) 204 and the duty solenoid (DSU) 203 when there is a possibility that a sudden deceleration state may occur in the belt-type continuously variable transmission 4 (at the time of failure). Fail safe is performed by switching the safe valve 305 to the fail position. As a result, the output hydraulic pressure of the clamping hydraulic pressure control valve 303 is supplied to the hydraulic actuator 41 c of the primary pulley 41. On the other hand, the ECU 8 controls the ON-OFF solenoid (SL) 204 and the duty solenoid (DSU) 203 when there is no possibility of sudden deceleration in the belt-type continuously variable transmission 4 (normal time). The fail-safe valve 305 is held in the normal position.

  As a case where the sudden deceleration state may occur in the belt-type continuously variable transmission 4, for example, the hydraulic pressure of the hydraulic actuator 41c of the primary pulley 41 may suddenly decrease. That is, the hydraulic pressure supply performance to the primary pulley 41 may be reduced. As the cause, for example, there is a case where the transmission hydraulic pressure control valve 301 or the linear solenoid (SLP) 201 that controls it has failed. The failure of the transmission hydraulic pressure control valve 301 and the linear solenoid (SLP) 201 includes a failure due to a mechanical factor such as a valve stick and a failure due to an electrical factor such as a disconnection or a short circuit (short).

  Whether or not there is a possibility of sudden deceleration in the belt-type continuously variable transmission 4 may be determined as follows. For example, the determination is made based on the deviation between the target transmission ratio of the belt type continuously variable transmission 4 and the actual transmission ratio, and it is determined that there is a possibility of sudden deceleration when the deviation is equal to or greater than a predetermined value. do it. The actual gear ratio of the belt type continuously variable transmission 4 can be calculated based on output signals of the primary pulley rotation speed sensor 105 and the secondary pulley rotation speed sensor 106. Alternatively, if the determination is made based on the fluctuation amount (decrease amount) of the hydraulic pressure of the hydraulic actuator 41c of the primary pulley 41, and if the fluctuation amount is equal to or greater than a predetermined value, it is determined that a sudden deceleration state may occur. Good. The hydraulic pressure of the hydraulic actuator 41c can be detected by providing a pressure sensor. Alternatively, when a disconnection or a short circuit of the transmission hydraulic pressure control valve 301 and the linear solenoid (SLP) 201 is detected, it may be determined that a sudden deceleration state may occur. A failure due to an electrical factor such as a disconnection or a short circuit can be detected by the ECU 8.

  According to this embodiment, in the belt-type continuously variable transmission 4, it is possible to suppress a rapid decrease in the hydraulic pressure of the hydraulic actuator 41 c of the primary pulley 41 and to avoid the occurrence of a sudden deceleration state. That is, by introducing the output hydraulic pressure of the clamping hydraulic pressure control valve 303 to the hydraulic actuator 41c, the change of the speed ratio γ to the deceleration side can be suppressed. In addition, belt slippage or overrev that occurs due to sudden deceleration can be prevented. Moreover, since the existing solenoid valves (ON-OFF solenoid (SL) 204 and duty solenoid (DSU) 203) are used for switching control of the fail-safe valve 305, it is possible to avoid an increase in cost and an increase in the size of the apparatus.

  Here, in the normal state, the ON-OFF solenoid (SL) 204 is in an open state in which the control hydraulic pressure PSL is output because the clutch apply control valve 401 is switched to the above-described engagement transition position and the forward clutch C1 is engaged. This is a case where control is performed. During this engagement transition control, the lockup clutch 24 is controlled to the released state, so that the control hydraulic pressure PDSU of the duty solenoid (DSU) 203 does not become the maximum pressure or the hydraulic pressure near the maximum pressure. Therefore, in this case, the control oil pressure PDSU is controlled to a lower oil pressure than the use area at the time of failure.

  On the other hand, when the control hydraulic pressure PDSU of the duty solenoid (DSU) 203 becomes a maximum pressure or a hydraulic pressure in the vicinity of the maximum pressure at the normal time, the lockup clutch 24 is held in a fully engaged state. In this state, the clutch apply control valve 401 is switched to the engagement position, and the forward clutch C1 is held in the fully engaged state. Therefore, in this case, the ON-OFF solenoid (SL) 204 is controlled in a closed state in which the control hydraulic pressure PSL is not output.

  As described above, the fail-safe valve 305 is switched to the fail position by utilizing a combination of control states of the ON-OFF solenoid (SL) 204 and the duty solenoid (DSU) 203 that are not used in the normal state. Therefore, according to this embodiment, it is possible to perform the switching control of the failsafe valve 305 without hindering the normal control.

  By the way, it can be considered that the fail-safe valve 305 is switched using a linear solenoid (SLS) 202 and a duty solenoid (DSU) 203.

  In this configuration, when the control hydraulic pressure of the linear solenoid (SLS) 202 and the control hydraulic pressure of the duty solenoid (DSU) 203 are both the maximum pressure or the hydraulic pressure near the maximum pressure, the fail-safe valve 305 is switched to the fail position. However, in this case, there are the following problems. When the fail safe valve 305 is switched to the fail position, the control hydraulic pressure of the linear solenoid (SLS) 202 is controlled to the maximum pressure or a hydraulic pressure near the maximum pressure, so the hydraulic pressure supplied to the hydraulic actuator 42c of the secondary pulley 42 is increased. Increase. For this reason, the belt clamping pressure increases and the load on the belt 43 increases.

  On the other hand, in this embodiment, since the linear solenoid (SLS) 202 is not used for switching control of the fail safe valve 305, when the fail safe valve 305 is switched to the fail position, the control hydraulic pressure of the linear solenoid (SLS) 202 is maximized. It is not necessary to control the oil pressure near the pressure. Therefore, the load on the belt 43 can be reduced, and the reliability at the limp home can be improved.

  Further, for example, in the hydraulic control circuit configured as shown in FIG. 4, switching of the failsafe valve 305 may be performed using a linear solenoid (SLS) 202 and a duty solenoid (DSU) 203. In the hydraulic control circuit shown in FIG. 4, the same components as those in the hydraulic control circuit shown in FIG. 4 includes an oil pump 7, a manual valve 20g, a linear solenoid (SLP) 201, a linear solenoid (SLS) 202, a duty solenoid (DSU) 203, an ON-OFF solenoid (SL) 204, and a primary regulator valve. 205, first modulator valve 206, second modulator valve 207, select reducing valve 208, transmission hydraulic pressure control valve 301, clamping hydraulic pressure control valve 303, fail safe valve 305, clutch apply control valve 401, clutch pressure control valve 403 The lockup control valve 405 is included.

  The line pressure PL adjusted by the primary regulator valve 205 is supplied to the first modulator valve 206, the transmission hydraulic pressure control valve 301, and the clamping hydraulic pressure control valve 303. The first modulator hydraulic pressure PM1 output from the first modulator valve 206 is supplied to the linear solenoid (SLP) 201, the linear solenoid (SLS) 202, the second modulator valve 207, and the select reducing valve 208, and the clutch apply control. The manual valve 20g and the lockup control valve 405 are supplied through the valve 401. The second modulator hydraulic pressure PM2 output from the second modulator valve 207 is supplied to a duty solenoid (DSU) 203 and an ON-OFF solenoid (SL) 204.

  The linear solenoid (SLP) 201 and the linear solenoid (SLS) 202 are normally open type solenoid valves. The control hydraulic pressure output from the linear solenoid (SLP) 201 is supplied to the transmission hydraulic pressure control valve 301. The control hydraulic pressure output from the linear solenoid (SLS) 202 is supplied to the select reducing valve 208, the clamping hydraulic pressure control valve 303, the fail safe valve 305, and the clutch pressure control valve 403.

  The duty solenoid (DSU) 203 is a normally closed type solenoid valve. The control hydraulic pressure output from the duty solenoid (DSU) 203 is supplied to the fail-safe valve 305 and the lock-up control valve 405, and is also supplied to the clutch apply control valve 401 via the lock-up control valve 405.

  The ON-OFF solenoid (SL) 204 is a normally open type solenoid valve. The ON-OFF solenoid (SL) 204 is configured to be switched to an open state that outputs a control hydraulic pressure when not energized, and to a closed state that does not output a control hydraulic pressure when energized. The control hydraulic pressure output from the ON-OFF solenoid (SL) 204 is supplied to the select reducing valve 208 and the clutch apply control valve 401.

  The select reducing valve 208 includes an output hydraulic pressure of the transmission hydraulic pressure control valve 301 introduced from the first control hydraulic pressure port 208a, a control hydraulic pressure of the linear solenoid (SLS) 202 introduced from the second control hydraulic pressure port 208b, 3 The control oil pressure of the ON-OFF solenoid (SL) 204 introduced from the control oil pressure port 208c is operated as a pilot pressure. The control oil pressure of the ON-OFF solenoid (SL) 204 is introduced on the side opposite to the output oil pressure of the transmission oil pressure control valve 301 and the control oil pressure of the linear solenoid (SLS) 202.

  The failsafe valve 305 is switched between the control hydraulic pressure of the duty solenoid (DSU) 203 introduced from the first control hydraulic pressure port 305a and the control hydraulic pressure of the linear solenoid (SLS) 202 introduced from the second control hydraulic pressure port 305b. Controlled by combination. Specifically, the fail-safe valve 305 is configured so that when the control hydraulic pressure of the linear solenoid (SLS) 202 and the control hydraulic pressure of the duty solenoid (DSU) 203 are both the maximum pressure or the hydraulic pressure near the maximum pressure, the right side of FIG. It is switched to the fail position shown in the half, and in other cases, it is switched to the normal position shown in the left half of FIG. When the fail safe valve 305 is held at the normal position, the input port 305c and the output port 305e communicate with each other, and the output hydraulic pressure of the transmission hydraulic pressure control valve 301 is supplied to the hydraulic actuator 41c of the primary pulley 41. On the other hand, when the fail safe valve 305 is held at the fail position, the input port 305d and the output port 305e communicate with each other. As a result, the output hydraulic pressure of the clamping hydraulic pressure control valve 303 is supplied to the hydraulic actuator 41 c of the primary pulley 41.

  In the hydraulic control circuit shown in FIG. 4, the control hydraulic pressure of the ON-OFF solenoid (SL) 204 is controlled by the first control hydraulic port 401 a of the clutch apply control valve 401 and the third control hydraulic port 208 c of the select reducing valve 208. To be supplied. For this reason, the ON-OFF solenoid (SL) 204 functions not only for switching control of the clutch apply control valve 401 (for supplying hydraulic pressure switching control of the friction engagement element for traveling) but also for adjusting the line pressure PL. To do. Specifically, the output hydraulic pressure of the select reducing valve 208 corresponds to the control hydraulic pressure of the ON-OFF solenoid (SL) 204 by switching the ON-OFF solenoid (SL) 204 between the closed state and the open state. It is changed as much as you do. Along with this, the line pressure PL is increased or decreased by an amount corresponding to the control hydraulic pressure of the ON-OFF solenoid (SL) 204.

  Further, since the control hydraulic pressure of the duty solenoid (DSU) 203 is supplied to the second control hydraulic pressure port 401b of the clutch apply control valve 401 via the control hydraulic pressure port 405a and the output port 405b of the lockup control valve 405, the duty solenoid By controlling the control hydraulic pressure of the (DSU) 203 to a hydraulic pressure higher than a predetermined pressure, the clutch apply control valve 401 can be held in the engaged position even when the ON-OFF solenoid (SL) 204 is closed. It becomes.

  On the other hand, by controlling the control hydraulic pressure of the duty solenoid (DSU) 203 to a hydraulic pressure lower than the predetermined pressure, the clutch apply control valve 401 can be held at the engagement transition position. In this state, the first modulator hydraulic pressure PM1 output from the first modulator valve 206 is introduced to the backup port 405c of the lockup control valve 405 via the input port 401c and the output port 401d of the clutch apply control valve 401. As a result, the lockup clutch 24 is forcibly released, and the engagement / release control of the lockup clutch 24 is not performed.

  However, in the hydraulic control circuit shown in FIG. 4, when the duty solenoid (DSU) 203 fails in a state where the control hydraulic pressure is output, if the control hydraulic pressure is higher than the predetermined pressure, the clutch apply control valve 401 is engaged. There is a possibility that switching to the engagement transition position cannot be performed. Then, the lock-up clutch 24 cannot be released and an engine stall may occur.

  On the other hand, in this embodiment, as described above, the lock-up clutch 24 is forcibly released as the ON-OFF solenoid (SL) 204 is controlled to be opened. Even if the (DSU) 203 fails in a state of outputting hydraulic pressure, the occurrence of engine stall can be prevented.

-Other embodiments-
Although the embodiment of the present invention has been described above, the embodiment shown here is an example and can be variously modified.

  In the above embodiment, the output hydraulic pressure of the clamping hydraulic pressure control valve 303 is supplied to the hydraulic actuator 41c of the primary pulley 41 at the time of failure. It is good also as a structure supplied to the actuator 41c. Alternatively, other hydraulic pressures such as the first modulator hydraulic pressure PM1, the second modulator hydraulic pressure PM2, and the secondary hydraulic pressure PSEC may be supplied to the hydraulic actuator 41c.

  Further, the engagement / release control of the lockup clutch 24 may be performed by a linear solenoid instead of the duty solenoid (DSU) 203. In this case, switching control of the fail safe valve 305 can be performed by the linear solenoid and the ON-OFF solenoid (SL) 204.

  In the above, an example in which the present invention is applied to a power transmission device for a vehicle equipped with a gasoline engine has been shown. However, the present invention is not limited to this, and a power transmission device for a vehicle equipped with another engine such as a diesel engine. It is also applicable to. In addition to the engine (internal combustion engine), the vehicle power source may be an electric motor or a hybrid power source including both the engine and the electric motor.

  The present invention is not limited to FF (front engine / front drive) type vehicles, but can also be applied to FR (front engine / rear drive) type vehicles and four-wheel drive vehicles.

1 is a schematic configuration diagram illustrating a vehicle according to an embodiment to which the present invention is applied. It is a block diagram which shows the structure of control systems, such as ECU of the vehicle of FIG. It is a circuit block diagram which shows the hydraulic control apparatus of the vehicle of FIG. It is a circuit block diagram which shows the comparative example of the hydraulic control apparatus of FIG.

Explanation of symbols

8 ECU
DESCRIPTION OF SYMBOLS 20 Hydraulic control circuit 2 Torque converter 24 Lockup clutch 3 Forward / reverse switching device C1 Forward clutch B1 Reverse brake 4 Belt type continuously variable transmission 41 Primary pulley (drive pulley)
41c Hydraulic actuator 42 Secondary pulley (driven pulley)
42c Hydraulic actuator 201 Linear solenoid (first solenoid valve)
203 Duty solenoid (second solenoid valve)
204 ON-OFF solenoid (third solenoid valve)
205 Primary regulator valve 301 Variable speed hydraulic control valve (control valve)
401 Clutch apply control valve 405 Lock-up control valve

Claims (5)

A belt-type continuously variable transmission that transmits power by clamping the belt with hydraulic pressure and changes the belt engagement diameter to change the gear ratio, and a fluid provided between the power source and the belt-type continuously variable transmission A hydraulic lockup clutch that is directly connected to the power source side and the belt type continuously variable transmission side, and the vehicle power transmission device establishes a power transmission path when the vehicle travels. In a hydraulic control device for a vehicle power transmission device comprising a hydraulic travel friction engagement element engaged to cause
A control valve that outputs hydraulic pressure supplied to the driving pulley of the belt type continuously variable transmission, a first electromagnetic valve that controls output hydraulic pressure of the first control valve, and an engagement pressure of the lockup clutch are controlled. A second solenoid valve, a third solenoid valve that switches the hydraulic pressure supplied to the traveling friction engagement element according to an engagement transient state or a complete engagement state of the traveling friction engagement element, and the driving pulley. A fail-safe valve capable of switching the hydraulic pressure to be supplied between the output hydraulic pressure of the control valve and a hydraulic pressure different from the output hydraulic pressure;
The fail-safe valve is switched to a fail position where the other hydraulic pressure is supplied to the driving pulley when there is a possibility of sudden deceleration in the belt-type continuously variable transmission. The output hydraulic pressure of the control valve is switched to the normal position for supplying to the driving pulley, and the switching of the fail-safe valve is controlled by the control hydraulic pressure of the second electromagnetic valve and the control hydraulic pressure of the third electromagnetic valve. Hydraulic control device characterized by. The hydraulic control device according to claim 1,
The hydraulic control device, wherein the second solenoid valve is a duty solenoid valve, and the third solenoid valve is an ON-OFF solenoid valve. In the hydraulic control device according to claim 2,
The fail-safe valve is configured to be switched to a fail position when the duty solenoid valve outputs a maximum pressure or a hydraulic pressure close to the maximum pressure and the ON-OFF solenoid valve is open. Hydraulic control device characterized by. In the hydraulic control device according to any one of claims 1 to 3,
A lockup control valve that operates in accordance with the control hydraulic pressure of the second electromagnetic valve during engagement / release control of the lockup clutch;
The lockup control valve is configured such that when the hydraulic pressure supplied to the traveling friction engagement element by the third electromagnetic valve is switched to a hydraulic pressure corresponding to an engagement transient state of the traveling friction engagement element, the third electromagnetic valve A hydraulic control apparatus configured to supply a control hydraulic pressure of a valve to a side opposite to a control hydraulic pressure of the second electromagnetic valve. In the hydraulic control device according to any one of claims 1 to 4,
The other hydraulic pressure includes a line pressure that is a source pressure of each part, a hydraulic pressure supplied to a driven pulley of the belt-type continuously variable transmission, a source pressure of any one of the solenoid valves, and a running friction. A hydraulic control device characterized in that any one of the engagement holding hydraulic pressures supplied to the traveling frictional engagement element in a fully engaged state of the engagement element.

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