JP4811068B2 - Powertrain control device - Google Patents

Description

  The present invention relates to a control apparatus for a power train, and more particularly to a technique for controlling a power train having a transmission connected to a power source via a friction engagement element operated by hydraulic pressure.

  2. Description of the Related Art Conventionally, a belt-type continuously variable transmission that performs a stepless change by connecting a primary pulley and a secondary pulley with a metal belt and changing the width of these pulleys is known. Some vehicles equipped with this belt-type continuously variable transmission travel forward only when a forward clutch provided between the engine and the engine is engaged. When the shift lever is in the non-travel position (for example, “N” position), the hydraulic pressure is drained and the forward clutch is released. When the shift lever is in the traveling position (for example, “D” position), the hydraulic pressure is supplied to the forward clutch. As a result, the forward clutch is engaged. When the vehicle is stopped when the shift lever is in the travel position, the driving force output from the engine is absorbed by a torque converter provided between the engine and the forward clutch. At this time, the engine load increases, or vibration transmitted from the engine to the vehicle increases. Therefore, when the neutral control execution condition including the condition that the vehicle stops when the shift lever is in the traveling position is satisfied, the neutral control that releases or slips the forward clutch by reducing the engagement force in the forward clutch. Is executed.

  Japanese Patent Application Laid-Open No. 11-166618 (Patent Document 1) discloses a neutral control device for a continuously variable automatic transmission for a vehicle that improves the fuel efficiency when the vehicle is stopped while keeping the vehicle stopped. The neutral control device for a continuously variable automatic transmission for a vehicle described in this publication includes a brake mechanism that allows / blocks rotation of an output shaft of a continuously variable automatic transmission for a vehicle, and a predetermined vehicle stop condition. The brake mechanism is operated to control the rotation of the output shaft, and the forward clutch portion (forward clutch) of the forward / reverse switching mechanism connected to the driven shaft of the continuously variable transmission mechanism is released to increase the driving force. The control part which controls to interrupt | block is included.

According to the neutral control device described in this publication, it is possible to prevent the stopped vehicle from moving by locking the output shaft of the continuously variable automatic transmission for the vehicle when the vehicle is stopped and setting it to the neutral state. The creep torque load on the engine can be eliminated. Therefore, it is possible to improve the fuel efficiency when the vehicle is stopped while keeping the vehicle stopped.
Japanese Patent Laid-Open No. 11-166618

  By the way, the engaging force of the forward clutch in the neutral control is controlled using a solenoid valve. As a solenoid valve for controlling the engagement force of the forward clutch in the neutral control, a solenoid valve for controlling the line pressure, for example, is diverted in a normal time when the neutral control is not performed. Therefore, when performing neutral control, another solenoid valve is used to control the line pressure. That is, the solenoid valve that controls the line pressure is changed by executing the neutral control. At this time, since the configuration for controlling the line pressure changes, the line pressure may not be normally controlled. However, Japanese Patent Laid-Open No. 11-166618 does not consider such a problem at all.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power train control device capable of suppressing the hydraulic pressure from being normally controlled.

  A power train control device according to a first aspect of the invention controls a power train having a transmission coupled to a power source via a friction engagement element that is operated by hydraulic pressure. The control device operates in accordance with the supplied hydraulic pressure, thereby supplying the first valve for adjusting the first hydraulic pressure and the second hydraulic pressure output from the second valve to the first valve. The first state and the second hydraulic pressure output from the third valve instead of the second hydraulic pressure are supplied to the first valve, and the second engagement is performed so that the engagement force of the friction engagement element is reduced. The switching means for selectively switching the second state for controlling the engagement force of the friction engagement element using the hydraulic pressure and the first condition when a predetermined condition including a condition that the vehicle is stopped is satisfied. An abnormality of the third valve is detected by the control means for controlling the switching means, the detection means for detecting the abnormality of the third valve, and the detection means so as to switch from the state of 2 to the second state. Switch from the first state to the second state. It includes prohibition means for prohibiting.

  According to the first invention, the first hydraulic pressure is adjusted by operating the first valve according to the hydraulic pressure supplied. The first state in which the second hydraulic pressure output from the second valve is supplied to the first valve, and the third hydraulic pressure output from the third valve in place of the second hydraulic pressure is the first valve. And the switching means selectively switches the second state in which the engagement force of the friction engagement element is controlled using the second hydraulic pressure so that the engagement force of the friction engagement element is reduced. When a predetermined condition including a condition that the vehicle is stopped is satisfied, the switching unit is controlled to switch from the first state to the second state. When the first state is switched to the second state, the engagement force of the friction engagement element is set using the second hydraulic pressure output from the second valve so that the engagement force of the friction engagement element is reduced. Be controlled. Thereby, the connection between a power source and a transmission can be weakened. Therefore, it is possible to suppress the load on the power source when the vehicle is stopped. In the second state, the third hydraulic pressure output from the third valve is supplied to the first valve instead of the second hydraulic pressure output from the second valve. At this time, if the third valve is abnormal, the first valve cannot operate normally. Therefore, the first hydraulic pressure adjusted by the first valve may not be normally controlled. Therefore, when an abnormality of the third valve is detected, switching from the first state to the second state is prohibited. Thereby, it can suppress that 1st hydraulic pressure cannot be normally controlled. Therefore, it is possible to provide a power train control device that can prevent the hydraulic pressure from being normally controlled.

  In the power train control device according to the second invention, in addition to the configuration of the first invention, the first hydraulic pressure is a hydraulic pressure generated by a hydraulic power source.

  According to the second invention, the hydraulic pressure generated by the hydraulic pressure source is adjusted by the first valve. Thereby, a desired oil pressure can be obtained from the oil pressure generated by the oil pressure source.

  In the power train control device according to the third invention, in addition to the configuration of the first or second invention, the transmission is a belt-type continuously variable transmission. The control device further includes means for controlling the clamping pressure of the belt in the belt-type continuously variable transmission according to the third hydraulic pressure in at least the second state.

  According to the third invention, at least in the second state, the belt clamping pressure in the belt-type continuously variable transmission is controlled according to the third hydraulic pressure. Thereby, if the third valve is normal, in the second state, both the first hydraulic pressure and the belt clamping pressure can be controlled using the third valve. For this reason, the number of devices necessary for controlling the power train can be suppressed.

  In the power train control device according to the fourth invention, in addition to the configuration of any one of the first to third inventions, the predetermined condition reduces the engagement force of the friction engagement element when the vehicle is stopped. This is a condition for executing neutral control.

  According to the fourth invention, when the condition for executing the neutral control for reducing the engagement force of the friction engagement element when the vehicle is stopped is satisfied, the first state is switched to the second state. The switching means is controlled. Thereby, the engagement force of a friction engagement element can be reduced and the connection between a power source and a transmission can be weakened. Therefore, it is possible to suppress the load on the power source when the vehicle is stopped.

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

  A vehicle equipped with a control device according to the present embodiment will be described with reference to FIG. The output of the engine 200 of the drive device 100 mounted on the vehicle is input to the belt type continuously variable transmission 500 via the torque converter 300 and the forward / reverse switching device 400. The output of the belt type continuously variable transmission 500 is transmitted to the reduction gear 600 and the differential gear device 700 and distributed to the left and right drive wheels 800. The driving device 100 is controlled by an ECU (Electronic Control Unit) 900 described later. The control device according to the present embodiment is realized by a program executed by ECU 900, for example. Instead of the belt type continuously variable transmission 500, a stepped automatic transmission having a gear train composed of planetary gears may be used.

  The torque converter 300 includes a pump impeller 302 connected to the crankshaft of the engine 200 and a turbine impeller 306 connected to the forward / reverse switching device 400 via the turbine shaft 304. A lockup clutch 308 is provided between the pump impeller 302 and the turbine impeller 306. The lockup clutch 308 is engaged or released when the hydraulic pressure supply to the engagement side oil chamber and the release side oil chamber is switched.

  When the lockup clutch 308 is completely engaged, the pump impeller 302 and the turbine impeller 306 are integrally rotated. The pump impeller 302 includes a mechanical oil pump 310 that generates a hydraulic pressure for controlling the shift of the belt type continuously variable transmission 500, generating a belt clamping pressure, and supplying lubricating oil to each part. Is provided.

  The forward / reverse switching device 400 is composed of a double pinion type planetary gear device. Turbine shaft 304 of torque converter 300 is connected to sun gear 402. The input shaft 502 of the belt type continuously variable transmission 500 is connected to the carrier 404. Carrier 404 and sun gear 402 are connected via forward clutch 406. Ring gear 408 is fixed to the housing via reverse brake 410. The forward clutch 406 and the reverse brake 410 are frictionally engaged by a hydraulic cylinder. The input rotational speed of the forward clutch 406 is the same as the rotational speed of the turbine shaft 304, that is, the turbine rotational speed NT.

  When the forward clutch 406 is engaged and the reverse brake 410 is released, the forward / reverse switching device 400 enters the forward engagement state. In this state, the driving force in the forward direction is transmitted to the belt type continuously variable transmission 500. When the reverse brake 410 is engaged and the forward clutch 406 is released, the forward / reverse switching device 400 enters the reverse engagement state. In this state, the input shaft 502 is rotated in the reverse direction with respect to the turbine shaft 304. As a result, the driving force in the reverse direction is transmitted to the belt type continuously variable transmission 500. When both forward clutch 406 and reverse brake 410 are released, forward / reverse switching device 400 enters a neutral state in which power transmission is interrupted.

  The belt type continuously variable transmission 500 includes a primary pulley 504 provided on the input shaft 502, a secondary pulley 508 provided on the output shaft 506, and a transmission belt 510 wound around these pulleys. Power is transmitted using frictional forces between the pulleys and the transmission belt 510.

  Each pulley is composed of a hydraulic cylinder so that the groove width is variable. By controlling the hydraulic pressure of the hydraulic cylinder of the primary pulley 504, the groove width of each pulley changes. As a result, the engagement diameter of the transmission belt 510 is changed, and the gear ratio GR (= primary pulley rotation speed NIN / secondary pulley rotation speed NOUT) is continuously changed.

  As shown in FIG. 2, the ECU 900 includes an engine speed sensor 902, a turbine speed sensor 904, a vehicle speed sensor 906, a throttle opening sensor 908, a cooling water temperature sensor 910, an oil temperature sensor 912, an accelerator opening sensor 914, a foot A brake switch 916, a position sensor 918, a primary pulley rotation speed sensor 922, and a secondary pulley rotation speed sensor 924 are connected.

  The engine speed sensor 902 detects the engine speed (engine speed) NE of the engine 200. The turbine rotation speed sensor 904 detects the rotation speed (turbine rotation speed) NT of the turbine shaft 304. The vehicle speed sensor 906 detects the vehicle speed V. The throttle opening sensor 908 detects the opening degree θ (TH) of the electronic throttle valve. Cooling water temperature sensor 910 detects cooling water temperature T (W) of engine 200. The oil temperature sensor 912 detects the oil temperature T (C) of the belt type continuously variable transmission 500 or the like. The accelerator opening sensor 914 detects the accelerator pedal opening A (CC). The foot brake switch 916 detects whether or not the foot brake is operated. The position sensor 918 detects the position P (SH) of the shift lever 920 by determining whether the contact provided at the position corresponding to the shift position is ON or OFF. Primary pulley rotation speed sensor 922 detects the rotation speed NIN of primary pulley 504. Secondary pulley rotation speed sensor 924 detects rotation speed NOUT of secondary pulley 508. A signal representing the detection result of each sensor is transmitted to ECU 900. The turbine rotational speed NT coincides with the primary pulley rotational speed NIN during forward traveling with the forward clutch 406 engaged. The vehicle speed V becomes a value corresponding to the secondary pulley rotation speed NOUT. Therefore, when the vehicle is stopped and the forward clutch 406 is engaged, the turbine speed NT is zero.

  ECU 900 includes a CPU (Central Processing Unit), a memory, an input / output interface, and the like. The CPU performs signal processing according to a program stored in the memory. Thereby, output control of the engine 200, shift control of the belt-type continuously variable transmission 500, belt clamping pressure control, engagement / release control of the forward clutch 406, engagement / release control of the reverse brake 410, and the like are executed.

  Output control of the engine 200 is performed by an electronic throttle valve 1000, a fuel injection device 1100, an ignition device 1200, and the like. Shift control of belt type continuously variable transmission 500, belt clamping pressure control, engagement / release control of forward clutch 406, and engagement / release control of reverse brake 410 are performed by hydraulic control circuit 2000.

  A part of the hydraulic control circuit 2000 will be described with reference to FIG. The hydraulic pressure generated by the oil pump 310 is supplied to the primary regulator valve 2100, the modulator valve (1) 2310 and the modulator valve (3) 2330 through the line pressure oil path 2002.

  The primary regulator valve 2100 is selectively supplied with control pressure from one of the SLT linear solenoid valve 2200 and the SLS linear solenoid valve 2210. In the present embodiment, both the SLT linear solenoid valve 2200 and the SLS linear solenoid valve 2210 are normally open solenoid valves (the hydraulic pressure output at the time of non-energization is maximized). Note that the SLT linear solenoid valve 2200 and the SLS linear solenoid valve 2210 may be normally closed (the hydraulic pressure output when not energized is minimized (“0”)).

  The spool of the primary regulator valve 2100 slides up and down according to the supplied control pressure. As a result, the hydraulic pressure generated by the oil pump 310 is regulated (adjusted) by the primary regulator valve 2100. The hydraulic pressure adjusted by primary regulator valve 2100 is used as line pressure PL. In the present embodiment, the higher the control pressure supplied to primary regulator valve 2100, the higher the line pressure PL. Note that the higher the control pressure supplied to the primary regulator valve 2100, the lower the line pressure PL may be.

  The SLT linear solenoid valve 2200 and the SLS linear solenoid valve 2210 are supplied with the hydraulic pressure regulated by the modulator valve (3) 2330 using the line pressure PL as a source pressure.

  SLT linear solenoid valve 2200 and SLS linear solenoid valve 2210 generate a control pressure in accordance with a current value determined by a duty signal transmitted from ECU 900.

  Of the control pressure (output hydraulic pressure) of the SLT linear solenoid valve 2200 and the control pressure (output hydraulic pressure) of the SLS linear solenoid valve 2210, the control pressure supplied to the primary regulator valve 2100 is selected by the control valve 2400.

  When the spool of the control valve 2400 is in the state (A) in FIG. 3 (left side state), the control pressure is supplied from the SLT linear solenoid valve 2200 to the primary regulator valve 2100. That is, the line pressure PL is controlled according to the control pressure of the SLT linear solenoid valve 2200.

  When the spool of the control valve 2400 is in the state (B) in FIG. 3 (right state), the control pressure is supplied from the SLS linear solenoid valve 2210 to the primary regulator valve 2100. That is, the line pressure PL is controlled according to the control pressure of the SLS linear solenoid valve 2210.

  When the spool of the control valve 2400 is in the state of (B) in FIG. 3, the control pressure of the SLT linear solenoid valve 2200 is supplied to a manual valve 2600 described later.

  The spool of the control valve 2400 is urged in one direction by a spring. Hydraulic pressure is supplied from the shift control duty solenoid (1) 2510 and the shift control duty solenoid (2) 2520 so as to oppose the urging force of the spring.

  When hydraulic pressure is supplied to the control valve 2400 from both the shift control duty solenoid (1) 2510 and the shift control duty solenoid (2) 2520, the spool of the control valve 2400 is in the state of (B) in FIG.

  When hydraulic pressure is not supplied to the control valve 2400 from at least one of the shift control duty solenoid (1) 2510 and the shift control duty solenoid (2) 2520, the spool of the control valve 2400 is driven by the biasing force of the spring. 3 is in the state (A).

  The hydraulic pressure adjusted by the modulator valve (4) 2340 is supplied to the shift control duty solenoid (1) 2510 and the shift control duty solenoid (2) 2520. The modulator valve (4) 2340 regulates the hydraulic pressure supplied from the modulator valve (3) 2330 to a constant pressure.

  The modulator valve (1) 2310 outputs a hydraulic pressure that is regulated using the line pressure PL as a source pressure. The hydraulic pressure output from the modulator valve (1) 2310 is supplied to the hydraulic cylinder of the secondary pulley 508. The hydraulic cylinder of the secondary pulley 508 is supplied with a hydraulic pressure that does not cause the transmission belt 510 to slip.

  The modulator valve (1) 2310 is provided with a spool that can move in the axial direction and a spring that biases the spool to one side. Modulator valve (1) 2310 regulates line pressure PL introduced to modulator valve (1) 2310 using the output hydraulic pressure of SLS linear solenoid valve 2210, which is duty controlled by ECU 900, as a pilot pressure. The hydraulic pressure adjusted by the modulator valve (3) is supplied to the hydraulic cylinder of the secondary pulley 508. The belt clamping pressure is increased or decreased according to the output hydraulic pressure from the modulator valve (1) 2310.

  The SLS linear solenoid valve 2210 is controlled so as to have a belt clamping pressure that does not cause belt slip, according to a map using the accelerator opening A (CC) and the gear ratio GR as parameters. Specifically, the excitation current for the SLS linear solenoid valve 2210 is controlled with a duty ratio corresponding to the belt clamping pressure. When the transmission torque changes suddenly during acceleration / deceleration or the like, belt slippage may be suppressed by increasing the belt clamping pressure.

  The hydraulic pressure supplied to the hydraulic cylinder of the secondary pulley 508 is detected by the pressure sensor 2312.

  The manual valve 2600 will be described with reference to FIG. Manual valve 2600 is mechanically switched according to the operation of shift lever 920. Thereby, the forward clutch 406 and the reverse brake 410 are engaged or released.

  Shift lever 920 is operated to a “P” position for parking, an “R” position for reverse travel, an “N” position for interrupting power transmission, a “D” position and “B” position for forward travel.

  In the “P” position and the “N” position, the hydraulic pressure in the forward clutch 406 and the reverse brake 410 is drained from the manual valve 2600. Thereby, the forward clutch 406 and the reverse brake 410 are released.

  In the “R” position, hydraulic pressure is supplied from the manual valve 2600 to the reverse brake 410. Thereby, the reverse brake 410 is engaged. On the other hand, the hydraulic pressure in forward clutch 406 is drained from manual valve 2600. As a result, the forward clutch 406 is released.

  When the control valve 2400 is in the state (A) in FIG. 4 (left side state), the modulator pressure PM supplied from the modulator valve (2) (not shown) is supplied to the manual valve 2600 via the control valve 2400. . The reverse brake 410 is held in the engaged state by the modulator pressure PM.

  When the control valve 2400 is in the state (B) in FIG. 4 (right side state), the hydraulic pressure adjusted by the SLT linear solenoid valve 2200 is supplied to the manual valve 2600. By adjusting the hydraulic pressure by the SLT linear solenoid valve 2200, the reverse brake 410 is gently engaged, and a shock at the time of engagement is suppressed.

  In the “D” position and the “B” position, hydraulic pressure is supplied from the manual valve 2600 to the forward clutch 406. As a result, the forward clutch 406 is engaged. On the other hand, the hydraulic pressure in the reverse brake 410 is drained from the manual valve 2600. Thereby, the reverse brake 410 is released.

  When the control valve 2400 is in the state (A) in FIG. 4 (left side state), the modulator pressure PM supplied from the modulator valve (2) (not shown) is supplied to the manual valve 2600 via the control valve 2400. . The forward clutch 406 is held in the engaged state by the modulator pressure PM.

  When the control valve 2400 is in the state (B) in FIG. 4 (right side state), the hydraulic pressure adjusted by the SLT linear solenoid valve 2200 is supplied to the manual valve 2600. By adjusting the hydraulic pressure by the SLT linear solenoid valve 2200, the forward clutch 406 is gently engaged, and a shock at the time of engagement is suppressed.

  The SLT linear solenoid valve 2200 normally controls the line pressure PL via the control valve 2400. The SLS linear solenoid valve 2210 normally controls the belt clamping pressure via the modulator valve (1) 2310.

  On the other hand, when the neutral control execution condition including the condition that the vehicle stops (the vehicle speed becomes “0”) with the shift lever 920 in the “D” position is satisfied, the SLT linear solenoid valve 2200 The engagement force of the forward clutch 406 is controlled so that the engagement force of 406 decreases. The SLS linear solenoid valve 2210 controls the belt clamping pressure via the modulator valve (1) 2310, and controls the line pressure PL instead of the SLT linear solenoid valve 2200.

  When a garage shift is performed in which the shift lever 920 is operated from the “N” position to the “D” position or the “R” position, the forward clutch 406 or the reverse brake 410 is gently engaged with the SLT linear solenoid valve 2200. Thus, the engagement force of the forward clutch 406 or the reverse brake 410 is controlled. The SLS linear solenoid valve 2210 controls the belt clamping pressure via the modulator valve (1) 2310, and controls the line pressure PL instead of the SLT linear solenoid valve 2200.

  With reference to FIG. 5, a configuration for performing the shift control will be described. Shift control is performed by controlling the supply and discharge of hydraulic pressure to and from the hydraulic cylinder of the primary pulley 504. Supply and discharge of hydraulic fluid to and from the hydraulic cylinder of the primary pulley 504 is performed using a ratio control valve (1) 2710 and a ratio control valve (2) 2720.

  The hydraulic cylinder of the primary pulley 504 is in communication with a ratio control valve (1) 2710 to which the line pressure PL is supplied and a ratio control valve (2) 2720 connected to the drain.

  The ratio control valve (1) 2710 is a valve for executing an upshift. The ratio control valve (1) 2710 is configured to open and close the flow path between the input port to which the line pressure PL is supplied and the output port connected to the hydraulic cylinder of the primary pulley 504 with a spool.

  A spring is disposed at one end of the spool of the ratio control valve (1) 2710. A port to which the control pressure from the shift control duty solenoid (1) 2510 is supplied is formed at the end opposite to the spring across the spool. Further, a port to which a control pressure is supplied from the shift control duty solenoid (2) 2520 is formed at the end on the side where the spring is disposed.

  When the control pressure from the shift control duty solenoid (1) 2510 is increased and the control pressure is not output from the shift control duty solenoid (2) 2520, the spool of the ratio control valve (1) 2710 in FIG. (D) state (right side state).

  In this state, the hydraulic pressure supplied to the hydraulic cylinder of the primary pulley 504 increases and the groove width of the primary pulley 504 becomes narrower. As a result, the gear ratio decreases. That is, an upshift is performed. Further, by increasing the supply flow rate of hydraulic oil at that time, the speed change speed is increased.

  The ratio control valve (2) 2720 is a valve for executing a downshift. A spring is disposed at one end of the spool of the ratio control valve (2) 2720. A port to which the control pressure from the shift control duty solenoid (1) 2510 is supplied is formed at the end on the side where the spring is disposed. A port to which the control pressure from the shift control duty solenoid (2) 2520 is supplied is formed at the end opposite to the spring across the spool.

  When the control pressure from the shift control duty solenoid (2) 2520 is increased and the control pressure is not output from the shift control duty solenoid (1) 2510, the spool of the ratio control valve (2) 2720 in FIG. The state (C) (the state on the left side) is reached. At the same time, the spool of the ratio control valve (1) 2710 is in the state (C) (left side state) in FIG.

  In this state, the hydraulic oil is discharged from the hydraulic cylinder of the primary pulley 504 via the ratio control valve (1) 2710 and the ratio control valve (2) 2720. Therefore, the groove width of the primary pulley 504 is widened. As a result, the gear ratio increases. That is, downshift. Further, by increasing the discharge flow rate of the hydraulic oil at that time, the speed change speed is increased.

  With reference to FIG. 6, a control structure of a program executed by ECU 900 of the control device according to the present embodiment will be described. Note that the program described below is repeatedly executed at a predetermined cycle.

  In step (hereinafter step is abbreviated as S) 100, ECU 900 determines whether or not a neutral control execution condition is satisfied. The neutral control execution condition includes a condition that the vehicle is stopped (the vehicle speed is “0”) with the shift lever 920 positioned at the “D” position, a condition that the foot brake is operated, and the engine 200 is idling. A condition such as a state is included.

  If the neutral control execution condition is satisfied (YES in S100), the process proceeds to S110. If not (NO in S100), the process proceeds to S200.

  In S110, ECU 900 determines whether SLS linear solenoid valve 2210 is normal or abnormal. The difference between the target hydraulic pressure determined according to the map using the accelerator opening A (CC) and the gear ratio GR as parameters and the actual hydraulic pressure detected by the pressure sensor 2312 is within a predetermined range including “0”. In this case, it is determined that the SLS linear solenoid valve 2210 is normal. Otherwise, it is determined that the SLS linear solenoid valve 2210 is abnormal.

  If SLS linear solenoid valve 2210 is normal (normal in S110), the process proceeds to S120. If SLS linear solenoid valve 2210 is abnormal (abnormal in S110), the process proceeds to S130.

  In S120, ECU 900 executes neutral control. In the neutral control, the hydraulic pressure is output from both the shift control duty solenoid (1) 2510 and the shift control duty solenoid (2) 2520. The SLT linear solenoid valve 2200 is controlled so that the engagement force of the forward clutch 406 is reduced and the forward clutch 406 slips with a desired slip amount. Further, the SLS linear solenoid valve 2210 is controlled so that a desired line pressure PL is obtained. Thereafter, this process ends.

  In S130, ECU 900 prohibits neutral control. Thereafter, the process proceeds to S300.

  In S200, ECU 900 determines whether or not shift lever 920 has been operated from the “N” position to the “D” position or the “R” position. That is, it is determined whether a garage shift has been performed. If shift lever 920 is operated from the “N” position to the “D” position or the “R” position (YES in S200), the process proceeds to S210. If not (NO in S200), the process proceeds to S300.

  In S210, ECU 900 executes garage shift control. That is, the garage shift control is executed regardless of whether the SLS linear solenoid valve 2210 is normal or abnormal.

  In the garage shift control, hydraulic pressure is output from both the shift control duty solenoid (1) 2510 and the shift control duty solenoid (2) 2520. After the hydraulic pressure supplied to the forward clutch 406 or the reverse brake 410 is increased to the initial control pressure at once, a constant pressure standby pressure lower than the initial control pressure is maintained for a predetermined time, and then at a predetermined gradient. The SLT linear solenoid valve 2200 is controlled so that the oil pressure gradually increases. Further, the SLS linear solenoid valve 2210 is controlled so that a desired line pressure PL and belt clamping pressure can be obtained. Thereafter, this process ends.

  In S300, ECU 900 performs normal control. That is, the shift control duty solenoid (1) 2510 and the shift control duty solenoid (1) 2510 and the shift control duty solenoid (2) 2520 are shifted so that the hydraulic pressure is output only from one of them. The shift control duty solenoid (2) 2520 is controlled. The SLT linear solenoid valve 2200 is controlled so that the desired line pressure PL is obtained. Further, the SLS linear solenoid valve 2210 is controlled so as to obtain a desired belt clamping pressure.

  An operation of ECU 900 that is the control device according to the present embodiment based on the above-described structure and flowchart will be described.

  If the neutral control execution condition is not satisfied (NO in S100) and the garage shift is not performed (NO in S200), normal control is performed (S300). The shift control duty solenoid (1) 2510 is controlled so that the hydraulic pressure is output only from one of the shift control duty solenoid (1) 2510 and the shift control duty solenoid (2) 2520 by normal control. And the shift control duty solenoid (2) 2520 is controlled. Further, the SLT linear solenoid valve 2200 is controlled so that a desired line pressure PL is obtained. Further, the SLS linear solenoid valve 2210 is controlled so as to obtain a desired belt clamping pressure.

  If neutral control execution conditions are satisfied during execution of normal control (YES in S100), it is determined whether SLS linear solenoid valve 2210 is normal or abnormal (S110).

  If SLS linear solenoid valve 2210 is normal (normal in S110), neutral control is executed (S120). With this neutral control, hydraulic pressure is output from both the shift control duty solenoid (1) 2510 and the shift control duty solenoid (2) 2520.

  As a result, the spool of the control valve 2400 is in a state (B) in FIG. 3 and FIG. 4 (right state). In this state, the engagement force of the forward clutch 406 decreases, and the SLT linear solenoid valve 2200 is controlled so that the forward clutch 406 slips with a desired slip amount. Thereby, the load of engine 100 when the vehicle stops can be suppressed. Therefore, ultimately, fuel consumption can be improved and vibrations in the vehicle can be suppressed.

  In the neutral control, the line pressure PL is controlled using an SLS linear solenoid valve 2210 instead of the SLT linear solenoid valve 2200. Thereby, a desired line pressure PL can be obtained.

  However, if the SLS linear solenoid valve 2210 is abnormal, the line pressure PL cannot be controlled normally. In particular, if the SLS linear solenoid valve 2210 is disconnected, the hydraulic pressure output from the SLS linear solenoid valve 2210 that is normally open is maximized. When this hydraulic pressure is supplied to the primary regulator valve 2100, the line pressure PL becomes maximum. Therefore, the load on oil pump 310, that is, the load on engine 200 increases. As a result, by executing neutral control, the fuel efficiency can be deteriorated.

  Therefore, if the SLS linear solenoid valve 2210 is abnormal (abnormal in S110), neutral control is prohibited (S130). Therefore, normal control is performed without performing neutral control (S300). That is, normal control is continued.

  The shift control duty solenoid (1) 2510 is controlled so that the hydraulic pressure is output only from one of the shift control duty solenoid (1) 2510 and the shift control duty solenoid (2) 2520 by normal control. And the shift control duty solenoid (2) 2520 is controlled.

  Therefore, the spool of the control valve 2400 is in the state (A) in FIG. 3 and FIG. 4 (left side state). In this state, the SLT linear solenoid valve 2200 is controlled so that a desired line pressure PL is obtained. Thereby, the line pressure PL is maximized, and an increase in the load of the oil pump 310, that is, the load of the engine 200 can be suppressed. As a result, it is possible to suppress the deterioration of fuel consumption by executing neutral control.

  If the neutral control execution condition is not satisfied (NO in S100), whether or not shift lever 920 has been operated from the “N” position to the “D” position or “R” position, that is, whether a garage shift has been performed. It is determined whether or not (S200).

  If a garage shift is performed (YES in S200), garage shift control is executed regardless of whether SLS linear solenoid valve 2210 is normal or abnormal (S210). That is, even when the SLS linear solenoid valve 2210 is abnormal, the garage shift control is executed (S210).

  This is because priority is given to suppressing the shock at the time of engagement of the forward clutch 406 or the reverse brake 410 rather than deterioration of a fuel consumption. With this garage shift control, hydraulic pressure is output from both the shift control duty solenoid (1) 2510 and the shift control duty solenoid (2) 2520.

  As a result, the spool of the control valve 2400 is in the state (B) in FIG. 3 and FIG. 4 (the state on the right side). In this state, after the hydraulic pressure supplied to the forward clutch 406 or the reverse brake 410 is increased to the initial control pressure at once, a constant pressure standby pressure lower than the initial control pressure is maintained for a predetermined time, and then predetermined. The SLT linear solenoid valve 2200 is controlled so that the hydraulic pressure gradually increases with the set gradient. Further, the SLS linear solenoid valve 2210 is controlled so that a desired line pressure PL is obtained. Thereby, the forward clutch 406 or the reverse brake 410 can be gently engaged. Therefore, the shock at the time of engagement can be suppressed.

  As described above, according to the ECU that is the control device according to the present embodiment, when the SLS linear solenoid valve is abnormal, the neutral control for controlling the line pressure PL by the SLS linear solenoid valve is prohibited. As a result, it is possible to suppress the line pressure PL from being normally controlled.

  In this embodiment, it is determined whether the SLS linear solenoid valve 2210 is normal or abnormal based on the hydraulic pressure detected by the pressure sensor 2312. However, the operating current value of the SLS linear solenoid valve 2210 By detecting this, it may be determined whether or not the SLS linear solenoid valve 2210 is abnormal. That is, whether or not the SLS linear solenoid valve 2210 is abnormal may be determined based on whether or not the current value corresponding to the duty signal from the ECU 900 is energized to the SLS linear solenoid valve 2210.

  Further, instead of the belt type continuously variable transmission 500, a chain type continuously variable transmission may be used, or a toroidal type continuously variable transmission may be used.

  Further, an oil pressure other than the line pressure may be controlled using the SLT linear solenoid valve 2200.

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

It is a skeleton figure of the vehicle carrying the control device concerning an embodiment of the invention. It is a control block diagram which shows the control apparatus which concerns on embodiment of this invention. It is FIG. (1) which shows the hydraulic control circuit controlled by the control apparatus which concerns on embodiment of this invention. It is FIG. (2) which shows the hydraulic control circuit controlled by the control apparatus which concerns on embodiment of this invention. It is FIG. (3) which shows the hydraulic control circuit controlled by the control apparatus which concerns on embodiment of this invention. It is a flowchart which shows the control structure of the program which ECU of the control apparatus which concerns on embodiment of this invention performs.

Explanation of symbols

  100 driving device, 200 engine, 300 torque converter, 310 oil pump, 400 forward / reverse switching device, 402 sun gear, 404 carrier, 406 forward clutch, 408 ring gear, 410 reverse brake, 500 belt type continuously variable transmission, 502 input shaft, 504 Primary pulley, 506 Output shaft, 508 Secondary pulley, 510 Transmission belt, 600 Reduction gear, 700 Differential gear device, 800 Drive wheel, 902 Engine speed sensor, 904 Turbine speed sensor, 906 Vehicle speed sensor, 908 Throttle opening Sensor, 910 Cooling water temperature sensor, 912 Oil temperature sensor, 914 Accelerator opening sensor, 916 Foot brake switch, 918 Position sensor, 920 Shift lever, 922 Primary -Speed sensor, 924 secondary pulley speed sensor, 1000 electronic throttle valve, 1100 fuel injection device, 1200 ignition device, 2000 hydraulic control circuit, 2002 line pressure oil path, 2100 primary regulator valve, 2200 SLT linear solenoid valve, 2210 SLS linear solenoid valve, 2310 modulator valve (1), 2330 modulator valve (3), 2340 modulator valve (4), 2312 pressure sensor, 2400 control valve, 2510 gear shift control duty solenoid (1), 2520 gear shift control duty solenoid (2) 2600 Manual valve, 2710 Ratio control valve (1), 2720 Ratio control valve (2).

Claims (3)

A control apparatus for a power train having a transmission coupled to a power source via a friction engagement element operated by hydraulic pressure,
A first valve for adjusting the first hydraulic pressure by operating according to the supplied hydraulic pressure;
The first state in which the second hydraulic pressure output from the second valve is supplied to the first valve, and the third hydraulic pressure output from the third valve in place of the second hydraulic pressure is the first state. In order to selectively switch the second state in which the engagement force of the frictional engagement element is controlled using the second hydraulic pressure so that the engagement force of the frictional engagement element is lowered while being supplied to the first valve. Switching means,
The switching means is configured to switch from the first state to the second state when a condition for executing neutral control for reducing the engagement force of the friction engagement element is satisfied when the vehicle is stopped. Control means for controlling
Detecting means for detecting an abnormality of the third valve;
A control apparatus for a power train, including prohibiting means for prohibiting switching from the first state to the second state when an abnormality of the third valve is detected by the detecting means.   The power train control device according to claim 1, wherein the first hydraulic pressure is a hydraulic pressure generated by a hydraulic pressure source. The transmission is a belt type continuously variable transmission,
3. The control device according to claim 1, further comprising means for controlling a clamping force of a belt in the belt-type continuously variable transmission according to the third hydraulic pressure in at least the second state. Powertrain control device.

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