vehicle

Abstract

To provide a vehicle capable of specifying an abnormal solenoid, the vehicle configured to be able to control engagement pressure of a clutch interposed into a power transmission path between a power source and a drive wheel by a first solenoid and a second solenoid.SOLUTION: When slippage is detected in a K0 clutch 20, after switching to a state in which an SLT solenoid 80 controls a K0 hydraulic pressure PRk0 of the K0 clutch 20, based on an engagement state of the K0 clutch 20 at the time when increasing an engine torque Te from a state in which the engine torque Te of an engine 12 is decreased, it is possible to specify which of an SCK0 solenoid 76 and the SLT solenoid 80 has an abnormality, so that it is possible to reduce costs for component replacement.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle that is provided with a clutch between a power source and drive wheels. [Background technology]

[0002] Patent Document 1 describes a configuration in which a torque converter is connected to an engine so that power can be transmitted, and it is determined whether a fault has occurred between the electric hydraulic pump or the linear solenoid valve based on the turbine rotation speed of the torque converter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-218736 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a configuration in which the engagement pressure of a clutch interposed in a power transmission path between a power source and drive wheels can be controlled by a first solenoid and a second solenoid, if an abnormality occurs in either the first solenoid or the second solenoid, no technology has been considered to identify which solenoid has experienced the abnormality.As a result, when an abnormality occurs, multiple solenoids need to be replaced, which could increase the cost of replacing parts.

[0005] The present invention has been made against the background of the above circumstances, and its purpose is to provide a vehicle in which the engagement pressure of a clutch interposed in a power transmission path between a power source and a drive wheel is controllable by a first solenoid and a second solenoid, and in which a solenoid in which an abnormality has occurred can be identified. [Means for solving the problem]

[0006] The gist of a first invention is a vehicle including: (a) a first solenoid and a second solenoid capable of controlling the engagement pressure of a clutch interposed in a power transmission path between a power source and drive wheels; and a control device that controls the first solenoid and the second solenoid, wherein the control device is configured to control the engagement pressure of the clutch by the first solenoid and the second solenoid under normal conditions, and to control the engagement pressure of the clutch by the second solenoid when slippage of the clutch is detected while the clutch is engaged; (b) the engagement pressure of the clutch when an abnormality occurs in the first solenoid is configured to be higher than the engagement pressure of the clutch when an abnormality occurs in the second solenoid; and (c) the control device, when slippage of the clutch is detected while the clutch is engaged, assumes that an abnormality has occurred in the first solenoid and: the power source and after the torque of the power source is reduced and the state in which the engagement pressure of the clutch is controlled by the first solenoid is switched from a state in which the engagement pressure of the clutch is controlled by the second solenoid, the system is configured to identify whether an abnormality has occurred in the first solenoid or the second solenoid based on the engagement state of the clutch when the torque of the power source is increased from a state in which the torque of the power source has been reduced. [Effects of the Invention]

[0007] According to the first aspect of the present invention, if clutch slippage is detected while the clutch is engaged, it is assumed that an abnormality has occurred in the first solenoid, and power sourceSince it is possible to identify whether an abnormality has occurred in the first solenoid or the second solenoid based on the clutch engagement state when the torque of the power source is increased from a state in which the torque of the power source is reduced after the state in which the clutch engagement pressure is controlled by the first solenoid is switched to a state in which the clutch engagement pressure is controlled by the second solenoid, and the cost of replacing parts can be reduced, specifically, if slippage occurs in the clutch during a transitional period in which the torque of the power source is increasing after the state in which the clutch engagement pressure is controlled by the second solenoid is switched to [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a hybrid vehicle to which the present invention is applied, and is also a diagram illustrating main parts of control functions and control systems for various controls in the vehicle. [Figure 2] FIG. 2 is a circuit diagram of a hydraulic control circuit provided in a vehicle that controls the hydraulic pressure of the hydraulic oil supplied to the hydraulic actuator of the K0 clutch. [Figure 3] This is a circuit diagram of a hydraulic control circuit provided in a vehicle that controls the hydraulic pressure of the hydraulic oil supplied to the hydraulic actuator of the K0 clutch, and shows the state of the circuit when switched to fail-safe. [Figure 4] This is a flowchart explaining the main control operations of the electronic control device, and is a flowchart explaining the control operations to identify whether an abnormality has occurred in the SCK0 solenoid or the SLT solenoid when slippage occurs in the K0 clutch. [Figure 5] 10 is a flowchart corresponding to another embodiment of the present invention, illustrating a control operation for identifying whether an abnormality has occurred in the SCKO solenoid or the SLT solenoid when slippage occurs in the K0 clutch. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in the following embodiments, the drawings are appropriately simplified or modified, and the dimensional ratios and shapes of the various parts are not necessarily drawn accurately. [Example]

[0010] FIG. 1 is a diagram illustrating the schematic configuration of a hybrid vehicle 10 (hereinafter referred to as vehicle 10) to which the present invention is applied, as well as a diagram illustrating the main parts of the control functions and control systems for various controls in vehicle 10. In FIG. 1, vehicle 10 is a hybrid vehicle equipped with an engine 12 and an electric motor MG, which are power sources for traveling. Vehicle 10 also has drive wheels 14 and a power transmission device 16 provided in a power transmission path between engine 12 and drive wheels 14. Note that engine 12 and electric motor MG correspond to the power source of the present invention.

[0011] The engine 12 is a known internal combustion engine such as a gasoline engine, a diesel engine, etc. An electronic control device 90 (described later) controls an engine control device 50 provided in the vehicle 10, which includes a throttle actuator of an electronic throttle valve, a fuel injection device, an ignition device, etc., to control the engine torque Te, which is the output torque of the engine 12.

[0012] The electric motor MG is a rotating electric machine, a so-called motor generator, that functions as both a motor that generates mechanical power from electric power and a generator that generates electric power from mechanical power. The electric motor MG is connected to a battery 54 provided in the vehicle 10 via an inverter 52 provided in the vehicle 10. The inverter 52 is controlled by an electronic control device 90 (described later), which controls the MG torque Tm, which is the output torque of the electric motor MG. For example, when the rotation direction of the electric motor MG is forward, which is the same as the rotation direction of the engine 12 during operation, the MG torque Tm is a powering torque when it is a positive torque on the acceleration side, and a regenerative torque when it is a negative torque on the deceleration side. Specifically, the electric motor MG generates power for traveling using electric power supplied from the battery 54 via the inverter 52 instead of or in addition to the engine 12. The electric motor MG also generates electric power using the power of the engine 12 and the driven force input from the drive wheels 14. The electric power generated by the electric motor MG is stored in the battery 54 via the inverter 52. The battery 54 is an electricity storage device that supplies and receives electric power to the electric motor MG. The electric power also refers to electrical energy unless otherwise specified. The power also refers to torque or force unless otherwise specified.

[0013] The power transmission device 16 includes a K0 clutch 20, a torque converter 22, an automatic transmission 24, and the like, housed within a case 18, which is a non-rotating member attached to the vehicle body. The K0 clutch 20 is a hydraulic friction engagement device interposed between the engine 12 and the electric motor MG in the power transmission path between the engine 12 and the drive wheels 14. The torque converter 22 is connected to the engine 12 via the K0 clutch 20.

[0014] The automatic transmission 24 is connected to the torque converter 22 and is interposed in a power transmission path between the torque converter 22 and the drive wheels 14. The torque converter 22 and the automatic transmission 24 each constitute part of the power transmission path between the engine 12 and the drive wheels 14. The power transmission device 16 also includes a propeller shaft 28 connected to a transmission output shaft 26, which is an output rotating member of the automatic transmission 24, a differential gear 30 connected to the propeller shaft 28, a pair of drive shafts 32 connected to the differential gear 30, etc. The power transmission device 16 also includes an engine connecting shaft 34 that connects the engine 12 and the K0 clutch 20, an electric motor connecting shaft 36 that connects the K0 clutch 20 and the torque converter 22, etc.

[0015] The electric motor MG is connected to the electric motor connecting shaft 36 within the case 18 so as to be able to transmit power. The electric motor MG is connected to a power transmission path between the engine 12 and the drive wheels 14, particularly to a power transmission path between the K0 clutch 20 and the torque converter 22. In other words, the electric motor MG is connected to the torque converter 22 and the automatic transmission 24 so as to be able to transmit power without passing through the K0 clutch 20. In other words, the torque converter 22 and the automatic transmission 24 each constitute part of the power transmission path between the electric motor MG and the drive wheels 14. The torque converter 22 and the automatic transmission 24 transmit driving power from the power sources of the engine 12 and the electric motor MG to the drive wheels 14, respectively.

[0016] The torque converter 22 includes a pump wheel 22a connected to an electric motor connecting shaft 36 and a turbine wheel 22b connected to a transmission input shaft 38, which is an input rotating member of the automatic transmission 24. The pump wheel 22a is connected to the engine 12 via the K0 clutch 20 and is also directly connected to the electric motor MG. The pump wheel 22a is the input member of the torque converter 22, and the turbine wheel 22b is the output member of the torque converter 22. The electric motor connecting shaft 36 is also the input rotating member of the torque converter 22. The transmission input shaft 38 is also the output rotating member of the torque converter 22, formed integrally with a turbine shaft that is rotationally driven by the turbine wheel 22b. The torque converter 22 is a fluid transmission that transmits driving force from each of the power sources (engine 12, electric motor MG) to the transmission input shaft 38 via fluid. The torque converter 22 includes a lock-up clutch 40 (hereinafter referred to as LU clutch 40) that connects the pump wheel 22a and the turbine wheel 22b. The LU clutch 40 is a known connect / disconnect clutch that connects and disconnects the input and output rotary members of the torque converter 22.

[0017] The operating state, i.e., the control state, of the LU clutch 40 is switched by changing the LU clutch torque Tlu, which is the torque capacity of the LU clutch 40, using the regulated LU oil pressure PRlu supplied from a hydraulic control circuit 56 provided in the vehicle 10. The control states of the LU clutch 40 include a fully released state in which the LU clutch 40 is released, a slip state in which the LU clutch 40 is engaged with slippage, and a fully engaged state in which the LU clutch 40 is engaged.

[0018] The automatic transmission 24 is a known planetary gear automatic transmission that includes, for example, one or more planetary gear sets (not shown) and multiple engagement devices CB. The engagement devices CB are hydraulic friction engagement devices that include, for example, multiple-plate or single-plate clutches or brakes pressed by hydraulic actuators, or band brakes tightened by hydraulic actuators. Each engagement device CB has its torque capacity, or CB torque Tcb, changed by the regulated CB oil pressure PRcb supplied from the hydraulic control circuit 56, thereby switching its control state, such as an engaged state or a disengaged state.

[0019] The automatic transmission 24 is a stepped transmission in which one of a plurality of gear stages (also referred to as gear stages) with different speed ratios (also referred to as gear ratios) γat (=AT input rotation speed Ni / AT output rotation speed No) is established by engaging one of the engagement devices CB. The automatic transmission 24 selectively establishes a plurality of gear stages by switching the established gear stages according to the accelerator operation of the driver (=operator) and the vehicle speed V, etc., using an electronic control device 90 (described later). The AT input rotation speed Ni is the rotation speed of the transmission input shaft 38 and is the input rotation speed of the automatic transmission 24. The AT input rotation speed Ni is also the rotation speed of the output rotating member of the torque converter 22 and is equivalent to the turbine rotation speed Nt, which is the output rotation speed of the torque converter 22. The AT input rotation speed Ni can be expressed in terms of the turbine rotation speed Nt. The AT output rotation speed No is the rotation speed of the transmission output shaft 26, and is the output rotation speed of the automatic transmission 24.

[0020] The K0 clutch 20 is a wet or dry friction engagement device configured with a multi-plate or single-plate clutch pressed by a hydraulic actuator 42 (see FIG. 2). The K0 clutch 20 switches between control states such as an engaged state and a disengaged state by controlling the operating state of the hydraulic actuator 42 by an electronic control device 90 (described later). In the K0 clutch 20, when a K0 oil pressure PRk0 adjusted by a hydraulic control circuit 56 is supplied to the hydraulic actuator 42, the K0 torque Tk0, which is the torque capacity of the K0 clutch 20, is changed, thereby switching the control state (engaged state) of the K0 clutch 20. The K0 clutch 20 corresponds to the clutch of the present invention, and the K0 oil pressure PRk0 of the K0 clutch 20 corresponds to the engagement pressure of the clutch of the present invention.

[0021] When the K0 clutch 20 is engaged, the pump wheel 22a and the engine 12 are rotated integrally via the engine connecting shaft 34. That is, when engaged, the K0 clutch 20 connects the engine 12 and the drive wheels 14 so that power can be transmitted between them. On the other hand, when the K0 clutch 20 is disengaged, power transmission between the engine 12 and the pump wheel 22a is interrupted. That is, when disengaged, the K0 clutch 20 disconnects the engine 12 and the drive wheels 14. Because the electric motor MG is connected to the pump wheel 22a, the K0 clutch 20 is provided in the power transmission path between the engine 12 and the electric motor MG and functions as a clutch that connects and disconnects the power transmission path, i.e., a clutch that connects and disconnects the engine 12 and the electric motor MG. That is, the K0 clutch 20 is an on-off clutch that connects the engine 12 and the electric motor MG when engaged and disconnects the connection between the engine 12 and the electric motor MG when disengaged.

[0022] In the power transmission device 16, when the K0 clutch 20 is engaged, the power output from the engine 12 is transmitted from the engine connecting shaft 34 to the drive wheels 14 via the K0 clutch 20, the electric motor connecting shaft 36, the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. in this order. Similarly, the power output from the electric motor MG is transmitted from the electric motor connecting shaft 36 to the drive wheels 14 via the torque converter 22, the automatic transmission 24, the propeller shaft 28, the differential gear 30, the drive shaft 32, etc. in this order, regardless of the control state of the K0 clutch 20.

[0023] The vehicle 10 is equipped with a MOP 58 which is a mechanical oil pump, an EOP 60 which is an electric oil pump, a pump motor 62, etc. The MOP 58 is connected to the pump impeller 22a and is driven to rotate by a power source (the engine 12, the electric motor MG) to discharge hydraulic oil used in the power transmission device 16. The pump motor 62 is a motor dedicated to the EOP 60 for driving the EOP 60 to rotate. The EOP 60 is driven to rotate by the pump motor 62 to discharge hydraulic oil. The hydraulic oil discharged by the MOP 58 and the EOP 60 is supplied to a hydraulic control circuit 56. The hydraulic control circuit 56 supplies a CB hydraulic pressure PRcb, a K0 hydraulic pressure PRk0, an LU hydraulic pressure PRlu, etc., each adjusted based on the hydraulic oil discharged by at least one of the MOP 58 and the EOP 60.

[0024] 2 and 3 show circuit diagrams of the hydraulic control circuit 56 provided in the vehicle 10 that controls the K0 hydraulic pressure PRk0, which is the hydraulic pressure of the hydraulic oil supplied to the hydraulic actuator 42 of the K0 clutch 20. Fig. 2 shows a state in which the K0 hydraulic pressure PRk0 supplied to the hydraulic actuator 42 is controlled by the control pressure Pslu output from the SCK0 linear solenoid valve 76, which will be described later, and Fig. 3 shows a state in which the K0 hydraulic pressure PRk0 is controlled by the regulator valve 70 and the SLT linear solenoid valve 80, which will be described later.

[0025] The hydraulic control circuit 56 is configured to include a regulator valve 70, a modulator valve 72, an SK0 solenoid valve 74 (hereinafter referred to as the SK0 solenoid 74), an SCK0 linear solenoid valve 76 (hereinafter referred to as the SCK0 solenoid 76), a switching valve 78, and an SLT linear solenoid valve 80 (hereinafter referred to as the SLT solenoid 80). Note that the SCK0 solenoid 76 corresponds to the first solenoid of the present invention, and the SLT solenoid 80 corresponds to the second solenoid of the present invention.

[0026] The regulator valve 70 is a pressure regulating valve that regulates the line pressure PL using as its source pressure the hydraulic oil pressure discharged from the MOP 58 or the EOP 60. The line pressure PL is a high hydraulic pressure that is used as the source pressure for the SCK0 solenoid 76, a linear solenoid valve (not shown) that controls the hydraulic actuator of the engagement device CB provided in the automatic transmission 24, and the like.

[0027] The regulator valve 70 is formed with an input port 70a that receives a pilot pressure Pslt output from an SLT solenoid 80, and is configured to precisely adjust the line pressure PL in accordance with the pilot pressure Pslt input from the input port 70a. The SLT solenoid 80 uses a modulator pressure Pm, which will be described later, as its source pressure, and outputs a pilot pressure Pslt that generates an appropriate line pressure PL in accordance with driving information, such as the throttle opening θth and the hydraulic oil temperature THoil.

[0028] The modulator valve 72 is configured to use the line pressure PL as its source pressure and output a modulator pressure Pm, which is a predetermined constant pressure. The modulator valve 72 includes an input port 72a to which the line pressure PL is input, an output port 72b to which the modulator pressure Pm is output, an oil chamber 72c, a spool valve element 72d, and a spring 72e. In the modulator valve 72, the spool valve element 72d is moved to a position where the biasing force generated by the hydraulic pressure in the oil chamber 72c and the biasing force of the spring 72e are balanced, thereby adjusting the modulator pressure Pm to the line pressure PL as its source pressure. The modulator pressure Pm output from the output port 72b is supplied to an input port 74a (described later) of the SK0 solenoid 74 via an oil passage 82.

[0029] The SK0 solenoid 74 is configured to output a switching pressure Psw using the modulator pressure Pm output from the modulator valve 72 as its source pressure. The SK0 solenoid 74 has an input port 74a to which the modulator pressure Pm is input and an output port 74b to which the switching pressure Psw is output. When a command signal to output the switching pressure Psw is input from the electronic control device 90 to the SK0 solenoid 74, the input port 74a and the output port 74b are connected, and the switching pressure Psw is output from the output port 74b. On the other hand, when a command signal to output the switching pressure Psw is not input from the electronic control device 90 to the SK0 solenoid 74, the input port 74a and the output port 74b are blocked, and the switching pressure Psw is not output from the output port 74b. The switching pressure Psw output from the output port 74b is supplied to an oil chamber 78c (described later) of the switching valve 78 via an oil passage 84.

[0030] The SCK0 solenoid 76 uses the line pressure PL as the source pressure and outputs a regulated control pressure Pslu. The SCK0 solenoid 76 has an input port 76a to which the line pressure PL is input, an output port 76b to which the regulated control pressure Pslu is output, and a feedback port 76c. The SCK0 solenoid 76 is a solenoid valve that can regulate the pressure to the control pressure Pslu in accordance with an electrical signal (current value) output from the electronic control device 90. The control pressure Pslu output from the output port 76b is supplied via an oil passage 86 to a first input port 78a (described later) of the switching valve 78.

[0031] The switching valve 78 is configured to be able to switch the K0 hydraulic pressure PRk0, which is the hydraulic pressure of the hydraulic oil supplied to the hydraulic actuator 42 of the K0 clutch 20, between either the control pressure Pslu or the line pressure PL output from the SCK0 solenoid 76. The switching valve 78 includes a first input port 78a to which the control pressure Pslu adjusted by the SCK0 solenoid 76 is input, a second input port 78b to which the line pressure PL is input, an oil chamber 78c that receives the switching pressure Psw output from the SK0 solenoid 74, an output port 78d that is connected to the hydraulic actuator 42 of the K0 clutch 20 via an oil passage 88, a spool valve element 78e, and a spring 78f.

[0032] The switching valve 78 switches the communication destination of the output port 78d between the first input port 78a and the second input port 78b by switching the position of the spool valve element 78e. The switching valve 78 shown in FIG. 2 shows a state in which the first input port 78a and the output port 78d are in communication. At this time, the control pressure Pslu output from the SCK0 solenoid 76 is supplied to the hydraulic actuator 42 of the K0 clutch 20 via the switching valve 78 and the oil passage 88. Meanwhile, the switching valve 78 shown in FIG. 3 shows a state in which the second input port 78b and the output port 78d are in communication. At this time, the line pressure PL is supplied to the hydraulic actuator 42 of the K0 clutch 20 via the switching valve 78 and the oil passage 88.

[0033] The spool valve element 78e of the switching valve 78 is moved by the biasing force based on the switching pressure Psw supplied to the oil chamber 78c and the biasing force of the spring 78f. For example, when the switching pressure Psw is not output from the SK0 solenoid 74, the switching pressure Psw is not supplied to the oil chamber 78c, and the spool valve element 78e is moved upward in the drawing by the biasing force of the spring 78f. At this time, the state shown in FIG. 2 is established, and the first input port 78a and the output port 78d are connected to each other. On the other hand, when the switching pressure Psw is output from the SK0 solenoid 74, the switching pressure Psw is supplied to the oil chamber 78c, and the spool valve element 78e is moved downward in the drawing against the biasing force of the spring 78f. At this time, the state shown in FIG. 3 is established, and the second input port 78b and the output port 78d are connected to each other.

[0034] In this way, the switching valve 78 switches its communication state depending on whether or not the switching pressure Psw is output from the SK0 solenoid 74, and when the switching pressure Psw is not output, the control pressure Pslu of the SK0 solenoid 76 is supplied to the hydraulic actuator 42 of the K0 clutch 20 via the switching valve 78 and the oil passage 88, and when the switching pressure Psw is output, the line pressure PL is supplied to the hydraulic actuator 42 via the switching valve 78 and the oil passage 88. In other words, when the switching pressure Psw is not output, the control pressure Pslu is supplied to the hydraulic actuator 42 as the K0 hydraulic pressure PRk0, and when the switching pressure Psw is output, the line pressure PL is supplied to the hydraulic actuator 42 as the K0 hydraulic pressure PRk0.

[0035] As described above, the hydraulic control circuit 56 is configured to be able to switch the K0 hydraulic pressure PRk0 supplied to the hydraulic actuator 42 of the K0 clutch 20 between the control pressure Pslu regulated by the SCK0 solenoid 76 and the line pressure PL. For example, if slippage of the K0 clutch 20 is detected while the K0 clutch 20 is engaged because the SCK0 solenoid 76 no longer outputs the control pressure Pslu, the switching valve 78 outputs the switching pressure Psw as a fail-safe, and the line pressure PL is supplied to the hydraulic actuator 42 as the K0 hydraulic pressure PRk0. As a result, the engaged state of the K0 clutch 20 can be maintained.

[0036] Returning to Fig. 1, the vehicle 10 further includes an electronic control unit 90 (control unit) that executes driving control of the vehicle 10. The electronic control unit 90 includes a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input / output interface, etc., and the CPU executes various controls of the vehicle 10 by performing signal processing in accordance with programs stored in the ROM in advance while utilizing the temporary storage function of the RAM. The electronic control unit 90 includes computers for engine control, electric motor control, hydraulic control, etc. as necessary.

[0037] The electronic control device 90 is supplied with various signals based on detection values ​​from various sensors provided on the vehicle 10 (e.g., an engine rotation speed sensor 92, a turbine rotation speed sensor 94, an output rotation speed sensor 96, an MG rotation speed sensor 98, an accelerator opening sensor 100, a throttle opening sensor 102, a brake switch 104, a battery sensor 106, and an oil temperature sensor 108) (e.g., an engine rotation speed Ne, which is the rotation speed of the engine 12; a turbine rotation speed Nt, which is the same value as the AT input rotation speed Ni; an AT output rotation speed No, which corresponds to the vehicle speed V; an MG rotation speed Nm, which is the rotation speed of the electric motor MG; an accelerator opening θacc, which is the amount of accelerator operation by the driver indicating the magnitude of the driver's acceleration operation; a throttle opening θth, which is the opening of the electronic throttle valve; a brake-on signal Bon, which is a signal indicating the state in which the brake pedal for operating the wheel brakes is being operated by the driver; a battery temperature THbat, a battery charge / discharge current Ibat, and a battery voltage Vbat of the battery 54; and a hydraulic oil temperature THoil, which is the temperature of the hydraulic oil in the hydraulic control circuit 56).

[0038] The electronic control device 90 outputs various command signals (e.g., an engine control command signal Se for controlling the engine 12, an MG control command signal Sm for controlling the electric motor MG, a CB hydraulic control command signal Sbc for controlling the engagement device CB, a K0 hydraulic control command signal Sk0 for controlling the K0 clutch 20, an LU hydraulic control command signal Slu for controlling the LU clutch 40, an EOP control command signal Seop for controlling the EOP 60, etc.) to each device provided in the vehicle 10 (e.g., the engine control device 50, the inverter 52, the hydraulic control circuit 56, the pump motor 62, etc.).

[0039] In order to realize various controls in the vehicle 10, the electronic control device 90 includes a hybrid control means, i.e., a hybrid control unit 120, a clutch control means, i.e., a clutch control unit 122, and a gear change control means, i.e., a gear change control unit 124.

[0040] The hybrid control unit 120 includes a function as an engine control means, i.e., an engine control unit 120a, that controls the operation of the engine 12, and a function as an electric motor control means, i.e., an electric motor control unit 120b, that controls the operation of the electric motor MG via the inverter 52, and performs hybrid drive control using the engine 12 and the electric motor MG, etc., using these control functions.

[0041] The hybrid control unit 120 calculates the amount of driving demand made by the driver to the vehicle 10, for example, by applying the accelerator opening θacc and the vehicle speed V to a driving demand map. The driving demand map is a relationship that is experimentally or design-based and stored in advance, i.e., a predetermined relationship. The driving demand is, for example, the required driving torque Trdem at the drive wheels 14. In other words, the required driving torque Trdem [Nm] is the required driving power Prdem [W] at the vehicle speed V at that time. The driving demand can also be the required driving force Frdem [N] at the drive wheels 14, the required AT output torque at the transmission output shaft 26, or the like. In calculating the driving demand, the AT output rotation speed No, or the like, can be used instead of the vehicle speed V.

[0042] The hybrid control unit 120 outputs an engine control command signal Se for controlling the engine 12 and an MG control command signal Sm for controlling the electric motor MG so as to realize the required driving power Prdem, taking into consideration factors such as transmission loss, the auxiliary load, the gear ratio γat of the automatic transmission 24, and the chargeable power Win and dischargeable power Wout of the battery 54. The engine control command signal Se is, for example, a command value for engine power Pe, which is the power of the engine 12 that outputs engine torque Te at a current engine rotation speed Ne. The MG control command signal Sm is, for example, a command value for power consumption Wm of the electric motor MG that outputs MG torque Tm at a current MG rotation speed Nm.

[0043] The chargeable power Win of the battery 54 is the maximum power that can be input, which defines a limit on the input power of the battery 54, and indicates the input limit of the battery 54. The dischargeable power Wout of the battery 54 is the maximum power that can be output, which defines a limit on the output power of the battery 54, and indicates the output limit of the battery 54. The chargeable power Win and dischargeable power Wout of the battery 54 are calculated by the electronic control device 90 based on, for example, the battery temperature THbat and the state-of-charge value SOC [%] of the battery 54. The state-of-charge value SOC of the battery 54 is a value that indicates the state of charge of the battery 54, and is calculated by the electronic control device 90 based on, for example, the battery charge / discharge current Ibat and the battery voltage Vbat.

[0044] When the required drive torque Trdem can be satisfied only with the output of the electric motor MG, the hybrid control unit 120 sets the drive mode to motor drive (=BEV drive) mode. In the BEV drive mode, the hybrid control unit 120 performs BEV drive, in which the vehicle runs using only the electric motor MG as a power source with the K0 clutch 20 in a disengaged state. On the other hand, when the required drive torque Trdem cannot be satisfied without using at least the output of the engine 12, the hybrid control unit 120 sets the drive mode to engine drive mode, i.e., hybrid drive (=HEV drive) mode. In the HEV drive mode, the hybrid control unit 120 performs engine drive, i.e., HEV drive, in which the vehicle runs using at least the engine 12 as a power source with the K0 clutch 20 in an engaged state. On the other hand, even when the required drive torque Trdem can be satisfied only with the output of the electric motor MG, the hybrid control unit 120 establishes the HEV drive mode when, for example, the state-of-charge value SOC of the battery 54 falls below a predetermined engine start threshold or when the engine 12 or the like needs to be warmed up. The engine start threshold is a predetermined threshold for determining that the state of charge value SOC is at a value at which it is necessary to forcibly start the engine 12 and charge the battery 54. In this way, the hybrid control unit 120 automatically stops the engine 12 during HEV driving, restarts the engine 12 after the engine has stopped, or starts the engine 12 during BEV driving, based on the required driving torque Trdem, etc., thereby appropriately switching between the BEV driving mode and the HEV driving mode.

[0045] The hybrid control unit 120 further includes a function as a start control means for starting the engine 12, that is, a start control unit 120c.

[0046] The start control unit 120c determines whether or not there is a request to start the engine 12. For example, in the BEV driving mode, the start control unit 120c determines whether or not there is a request to start the engine 12 based on whether or not the required drive torque Trdem has increased beyond a range that can be covered by the output of the electric motor MG alone, whether or not warm-up of the engine 12, etc. is necessary, or whether or not the state of charge value SOC of the battery 54 is less than the engine start threshold. The start control unit 120c also determines whether or not the start control of the engine 12 has been completed.

[0047] The clutch control unit 122 controls the K0 clutch 20 to execute start control of the engine 12. For example, when the start control unit 120c determines that there is a request to start the engine 12, the clutch control unit 122 outputs a K0 hydraulic control command signal Sk0 to the hydraulic control circuit 56 to control the K0 clutch 20 from a released state toward an engaged state so as to obtain a K0 torque Tk0 for transmitting to the engine 12 a torque required for cranking the engine 12 (hereinafter, required cranking torque Tcrn), which is a torque that increases the engine rotation speed Ne. That is, when starting the engine 12, the clutch control unit 122 outputs a K0 hydraulic control command signal Sk0 to the hydraulic control circuit 56 to control the hydraulic actuator 42 of the K0 clutch 20 to switch the control state of the K0 clutch 20 from a released state to an engaged state. As a result, as the K0 clutch 20 is engaged, the engine rotation speed Ne is increased to a rotation speed at which the engine 12 can be self-sustained, and the engine 12 is started.

[0048] The start control unit 120c controls the engine 12 and the electric motor MG to execute start control of the engine 12. For example, when the start control unit 120c determines that there is a request to start the engine 12, the start control unit 120c outputs an MG control command signal Sm to the inverter 52 to cause the electric motor MG to output the required cranking torque Tcrn in response to the clutch control unit 122 switching the K0 clutch 20 to the engaged state. In other words, when starting the engine 12, the start control unit 120c outputs the MG control command signal Sm to the inverter 52 to control the electric motor MG to output the required cranking torque Tcrn, i.e., to increase the MG torque Tm by the required cranking torque Tcrn.

[0049] Furthermore, when the start control unit 120c determines that there is a request to start the engine 12, it outputs an engine control command signal Se to the engine control device 50 to start fuel supply, engine ignition, and the like, in conjunction with cranking of the engine 12 by the K0 clutch 20 and the electric motor MG. That is, when starting the engine 12, the start control unit 120c outputs an engine control command signal Se to the engine control device 50 to control the engine 12 so that the engine 12 starts operating.

[0050] The shift control unit 124 determines whether to shift the automatic transmission 24 using, for example, a shift map, which is a predetermined relationship, and outputs a CB hydraulic control command signal Scb to the hydraulic control circuit 56 as needed to control the shift of the automatic transmission 24. When controlling the shift of the automatic transmission 24, the shift control unit 124 performs shifts of the automatic transmission 24, for example, by switching a disengaging engagement device to a disengaged state and switching an engaging engagement device to an engaged state. The shift map is a predetermined relationship having shift lines on a two-dimensional coordinate system using, for example, vehicle speed V and required drive torque Trdem as variables, for determining whether to shift the automatic transmission 24. In the shift map, the AT output rotation speed No or the like may be used instead of the vehicle speed V, and the required drive force Frdem, accelerator opening θacc, throttle opening θth, or the like may be used instead of the required drive torque Trdem.

[0051] Incidentally, under normal circumstances, as shown in FIG. 2, the hydraulic actuator 42 of the K0 clutch 20 is supplied with the control pressure Pslu output from the SCK0 solenoid 76 as the K0 hydraulic pressure PRk0. In other words, the K0 clutch 20 is controlled by the SCK0 solenoid 76. The line pressure PL supplied to the SCK0 solenoid 76 as the source pressure is controlled by the regulator valve 70, or more precisely, by the SLT solenoid 80 that outputs the pilot pressure Pslt to the regulator valve 70. In other words, under normal circumstances, the K0 hydraulic pressure PRk0 of the K0 clutch 20 is controlled by the SCK0 solenoid 76 and the SLT solenoid 80. On the other hand, if slippage is detected in the K0 clutch 20 due to an abnormality such as the SCK0 solenoid 76 no longer outputting the control pressure Pslu, as shown in FIG. 3, the switching pressure Psw is output from the SCK0 solenoid 74, and the line pressure PL is supplied to the hydraulic actuator 42 of the K0 clutch 20 as the K0 hydraulic pressure PRk0. That is, if slippage is detected in the K0 clutch 20 while the K0 clutch 20 is engaged, the K0 oil pressure PRk0 of the K0 clutch 20 is controlled by the SK0 solenoid 74 and the SLT solenoid 80 which essentially adjusts the line pressure PL.

[0052] As described above, when considering the normal operation and the occurrence of an abnormality, the K0 clutch 20 is controlled by the SK0 solenoid 74, the SCK0 solenoid 76, and the SLT solenoid 80. If the SCK0 solenoid 76 fails and the control pressure Pslu is no longer output from the SCK0 solenoid 76, or if the control pressure Pslu drops, the K0 oil pressure PRk0 of the hydraulic actuator 42 drops, causing slippage in the K0 clutch 20. Similarly, if the SLT solenoid 80, which essentially controls the line pressure PL, fails and the line pressure PL drops, the K0 oil pressure PRk0 of the hydraulic actuator 42 drops, causing slippage in the K0 clutch 20. As described above, the behavior of the vehicle 10 is the same when the SCK0 solenoid 76 fails and when the SLT solenoid 80 fails. Therefore, if slippage of the K0 clutch 20 is detected, it becomes necessary to replace even a normal linear solenoid valve. In particular, if the mechanical components (assemblies) to which the SCKO solenoid 76 and the SLT solenoid 80 are assembled are different, each assembly will have to be replaced, which increases the burden of maintenance. Note that this embodiment is configured so that the line pressure PL regulated by the regulator valve 70 decreases as the pilot pressure Pslt output from the SLT solenoid 80 increases. Therefore, if the pilot pressure Pslt of the SLT solenoid 80 becomes stuck at a high pressure or an ON failure of the SLT solenoid 80 occurs, the line pressure PL may decrease to a predetermined pressure, causing slippage in the K0 clutch 20.

[0053] In contrast, the electronic control device 90 is functionally equipped with an abnormality identification unit 128 as an abnormality identification means that, when slippage of the K0 clutch 20 is detected while the K0 clutch 20 is engaged, identifies whether an abnormality has occurred in the SCK0 solenoid 76 or the SLT solenoid 80.

[0054] The abnormality identification unit 128 determines whether slippage has been detected in the K0 clutch 20 while the vehicle is running with the K0 clutch 20 engaged. Specifically, the abnormality identification unit 128 calculates the rotational speed difference ΔNk0 between the rotational speed of the engine connecting shaft 34, which rotates integrally with the input rotating member of the K0 clutch 20, and the rotational speed of the electric motor connecting shaft 36, which rotates integrally with the output rotating member of the K0 clutch 20, and determines whether slippage has occurred in the K0 clutch 20 based on whether the rotational speed difference ΔNk0 remains equal to or greater than a threshold value α1 for a predetermined time t1. In this embodiment, the above determination is made by the engine control ECU.

[0055] Here, because the engine connecting shaft 34 is connected to the engine 12, the rotational speed of the engine connecting shaft 34 is the same as the engine rotational speed Ne. Furthermore, because the electric motor connecting shaft 36 is connected to the electric motor MG, the rotational speed of the electric motor connecting shaft 36 is the same as the MG rotational speed Nm of the electric motor MG. Therefore, the rotational speed difference ΔNk0 of the K0 clutch 20 is calculated as the difference between the engine rotational speed Ne and the MG rotational speed Nm (=|Ne-Nm|). Furthermore, the threshold value α1 is determined in advance experimentally or by design, and is set to a lower limit value of the rotational speed difference ΔNk0 at which it is possible to determine that an abnormality has occurred in the SCK0 solenoid 76 or the SLT solenoid 80. Furthermore, the predetermined time t1 is also determined in advance experimentally or by design, and is set to a value that excludes cases where the K0 clutch 20 momentarily slips for some reason.

[0056] If the rotational speed difference ΔNk0 remains equal to or greater than the threshold value α1 for a predetermined time t1 or longer, the abnormality identification unit 128 determines that slippage has been detected in the K0 clutch 20. At this time, the abnormality identification unit 128 assumes that an abnormality has occurred in the SCK0 solenoid 76, and as a fail-safe, performs a so-called engine torque down operation by fully closing the electronic throttle valve and cutting fuel from the engine 12 to reduce the engine torque Te. Furthermore, as a fail-safe, the abnormality identification unit 128 outputs a switching pressure Psw from the SCK0 solenoid 74, thereby switching the K0 hydraulic pressure PRk0 supplied to the hydraulic actuator 42 of the K0 clutch 20 from the control pressure Pslu of the SCK0 solenoid 76 to the line pressure PL. That is, when slippage of the clutch 20 is detected, the abnormality identification unit 128 switches the hydraulic control circuit 56 from the normal state shown in FIG. 2 to the state shown in FIG. 3 as a fail-safe, that is, switches to a state in which the K0 hydraulic pressure PRk0 of the K0 clutch 20 is essentially controlled by the SLT solenoid 80.

[0057] As a fail-safe, when the engine torque reduction of the engine 12 and the switching of the oil passage of the hydraulic control circuit 56 are completed, the abnormality identification unit 128 increases the engine torque Te from the reduced state at a predetermined gradient, thereby restoring the engine torque Te to its original state. At this time, the upper limit value of the engine torque Te is set to be equal to or less than the engine torque Te calculated based on the accelerator operation amount by the driver, i.e., the accelerator opening θacc. Furthermore, the upper limit value of the engine torque Te is set so as not to exceed the maximum value of the K0 torque Tk0 of the K0 clutch 20 when the line pressure PL is supplied to the hydraulic actuator 42 of the K0 clutch 20.

[0058] Here, in the hydraulic control circuit 56 of this embodiment, the K0 torque Tk0 of the K0 clutch 20 during fail-safe is set to a different value when an abnormality occurs in the SCK0 solenoid 76 and when an abnormality occurs in the SLT solenoid 80. Specifically, the K0 torque Tk0 of the K0 clutch 20 when an abnormality occurs in the SCK0 solenoid 76 (hereinafter referred to as K0 torque Tk01 for distinction) is set to be greater than the K0 torque Tk0 of the K0 clutch 20 when an abnormality occurs in the SLT solenoid 80 (hereinafter referred to as K0 torque Tk02 for distinction) (Tk01>Tk02). In other words, the K0 oil pressure PRk01 of the hydraulic oil supplied to the hydraulic actuator 42 when an abnormality occurs in the SCK0 solenoid 76 is set to be higher than the K0 oil pressure PRk02 of the hydraulic oil supplied to the hydraulic actuator 42 when an abnormality occurs in the SLT solenoid 80 (PRk01>PRk02).

[0059] If the fail-safe mode is switched to due to an abnormality in the SCK0 solenoid 76, the SLT solenoid 80 is normal, and therefore a high line pressure PL is supplied to the hydraulic actuator 42 of the K0 clutch 20. At this time, the K0 torque Tk01 of the K0 clutch 20 is at a level that does not cause slippage even when the engine torque Te is restored. Therefore, if no slippage occurs in the K0 clutch 20 during the transitional period in which the engine torque Te is restored, it can be determined that an abnormality has occurred in the SCK0 solenoid 76. On the other hand, if the fail-safe mode is switched to due to an abnormality (on-failure) in the SLT solenoid 80, the line pressure PL decreases, and the K0 torque Tk02 of the K0 clutch 20 becomes significantly smaller than the K0 torque Tk01. In relation to this, when the engine torque Te is restored, slippage occurs in the clutch 20 during the transitional period. Therefore, if slippage occurs in the K0 clutch 20 during the transition period in which the engine torque Te is restored after switching to the failsafe mode, it can be determined that an abnormality (ON failure) has occurred in the SLT solenoid 80.

[0060] The abnormality identification unit 128 determines whether the amount of stored energy per unit area E (J / cm^2) calculated by the following formula (1) is equal to or greater than a threshold value α2 during the recovery transition of the engine torque Te from a state in which the engine torque Te has decreased due to switching to the fail-safe mode. In formula (1), Tk0f corresponds to the K0 torque Tk0f (minimum value) when the line pressure PL is supplied to the hydraulic actuator 42 as a fail-safe in the event of a failure (on-failure) of the SLT solenoid 80. When the SLT solenoid 80 fails, the line pressure PL becomes a minimum pressure that is predetermined by design. Therefore, the K0 torque Tk0f also becomes a predetermined minimum value. Also, in formula (1), Sk0 corresponds to the area of ​​the friction material that constitutes the K0 clutch 20. The amount of stored energy E is determined by accumulating values ​​calculated as needed based on formula (1). In other words, the amount of stored energy E corresponds to the amount of heat generated in the K0 clutch 20. The threshold value α2 is determined in advance experimentally or by design, and is set to a threshold value of the stored amount E at which it can be determined that an abnormality has occurred in the SLT solenoid 80. Note that the stored amount of energy E is maintained during the recovery transition period of the engine torque Te after the failsafe function is activated, but once a predetermined time has passed since the K0 clutch 20 was engaged, heat generation from the K0 clutch 20 ceases, and therefore the stored amount E is reset to zero once the predetermined time has passed since the K0 clutch 20 was engaged. In this embodiment, the above determination based on equation (1) is performed by the clutch control ECU. E={(|Ne-Nm|)×2π / 60}×Tk0f / Sk0 (1)

[0061] The abnormality identification unit 128 determines that an abnormality has occurred in the SLT solenoid 80 if the amount of accumulated energy E becomes equal to or greater than the threshold value α2 during the recovery transition period of the engine torque Te. On the other hand, the abnormality identification unit 128 determines that an abnormality has occurred in the SCK0 solenoid 76 if the amount of accumulated energy E becomes less than the threshold value α2. In this way, based on the amount of accumulated energy E (i.e., the amount of heat generated) during the recovery transition period of the engine torque Te after the failsafe function, it is possible to identify whether the slippage of the K0 clutch 20 is due to an abnormality in the linear solenoid valve 76 or an abnormality in the SLT solenoid 80. In this way, the electronic control unit 90 is configured to identify whether an abnormality has occurred in the SCK0 solenoid 76 or the SLT solenoid 80, based on the engagement state of the K0 clutch 20 when the engine torque Te increases from a state in which the engine torque Te has decreased.

[0062] 4 is a flowchart illustrating the main control operations of the electronic control unit 90, and is a flowchart illustrating the control operations for identifying whether an abnormality has occurred in the SCKO solenoid 76 or the SLT solenoid 80 when slippage occurs in the K0 clutch 20. This flowchart is repeatedly executed while the vehicle is running with the K0 clutch 20 engaged.

[0063] First, in step S10 (hereinafter, the term "step" will be omitted) corresponding to the control function of the abnormality identification unit 128, it is determined whether the rotational speed difference ΔNk0 calculated from the difference (=|Ne-Nm|) between the engine rotational speed Ne and the MG rotational speed Nm is equal to or greater than the threshold value α1 for a predetermined time t1 or longer. If the determination in S10 is negative, the routine is terminated. If the determination in S10 is positive, it is provisionally determined in S20 corresponding to the control function of the abnormality identification unit 128 that there is an abnormality in the SCK0 solenoid 76. Next, in S30 corresponding to the control function of the abnormality identification unit 128, the electronic throttle valve is fully closed and fuel is cut off, thereby reducing the engine torque of the engine 12. In addition, by outputting the switching pressure Psw from the SCK0 solenoid 74, the hydraulic control circuit 56 is switched to a state in which the line pressure PL is supplied to the hydraulic actuator 42 of the K0 clutch 20 as a fail-safe. In S40, which corresponds to the control function of the abnormality identifying unit 128, the engine torque Te is increased at a predetermined gradient (engine torque down recovery).

[0064] In S50, which corresponds to the control function of the abnormality identification unit 128, it is determined whether the amount of accumulated energy E calculated by the above-mentioned formula (1) is equal to or greater than the threshold value α2. If the determination in S50 is negative, slippage in the K0 clutch 20 has ceased, and therefore an abnormality in the SCKO solenoid 76 is confirmed (identified). On the other hand, if the determination in S50 is positive, energy is being generated due to slippage of the K0 clutch 20, and therefore an abnormality in the SLT solenoid 80 is identified in S60, which corresponds to the control function of the abnormality identification unit 128.

[0065] As described above, according to this embodiment, if slippage is detected in the K0 clutch 20, after the state is switched to one in which the K0 oil pressure PRk0 of the K0 clutch 20 is controlled by the SLT solenoid 80, it is possible to identify whether an abnormality has occurred in the SCK0 solenoid 76 or the SLT solenoid 80 based on the engagement state of the K0 clutch 20 when the engine torque Te of the engine 12 is increased from a state in which the engine torque Te of the engine 12 has been reduced, thereby reducing the cost of replacing parts. Specifically, if slippage occurs in the K0 clutch 20 during a transitional period in which the engine torque Te of the engine 12 is increasing after the state is switched to one in which the K0 oil pressure PRk0 of the K0 clutch 20 is controlled by the SLT solenoid 80, it is possible to identify an abnormality in the SCK0 solenoid 80, and if slippage does not occur in the K0 clutch 20, it is possible to identify an abnormality in the SCK0 solenoid 76.

[0066] Next, another embodiment of the present invention will be described. In the following description, parts common to the above embodiment will be designated by the same reference numerals and description thereof will be omitted. [Example]

[0067] 4, step S10 of determining whether an abnormality has occurred based on the rotational speed difference ΔNk0 of the K0 clutch 20 is executed by the engine control ECU, and step S50 of determining whether an abnormality has occurred based on the amount of stored energy E is executed by the hydraulic control ECU, and the abnormality determinations are executed by separate ECUs. In this regard, in the above-described embodiment, the abnormality determination for the SCK0 solenoid 76 and the abnormality determination for the SLT solenoid 80 are executed independently. On the other hand, if the step of determining whether an abnormality has occurred based on the rotational speed difference ΔNk0 of the K0 clutch 20 and the step of determining whether an abnormality has occurred based on the amount of stored energy E are executed by a common ECU (for example, an engine control ECU), these can be executed simultaneously.

[0068] 5 is a flowchart illustrating essential parts of an electronic control device according to another embodiment of the present invention, and is another flowchart illustrating a control operation for identifying whether an abnormality has occurred in the SCK0 solenoid 76 or the SLT solenoid 80 when slippage occurs in the K0 clutch 20. The flowchart of this embodiment is preferably applied when a common ECU executes the step of determining the occurrence of an abnormality from the rotational speed difference ΔNk0 of the K0 clutch 20 and the step of determining the occurrence of an abnormality from the amount of stored energy E. Note that each of the steps (S100 to S160) shown in FIG. 5 corresponds to the abnormality identification unit 128 in the above-described embodiment.

[0069] First, in step S100 (hereinafter, the step will be omitted) shown in FIG. 5, it is determined whether the rotational speed difference ΔNk0 calculated from the difference (=|Ne−Nm|) between the engine rotational speed Ne and the MG rotational speed Nm is equal to or greater than the threshold value α1 for a predetermined time t1 or longer. If the determination in S100 is negative, the routine is terminated. If the determination in S100 is positive, the routine proceeds to S110, where, as a fail-safe, the engine torque of the engine 12 is reduced and the K0 clutch 20 is engaged by the SK0 solenoid 74. At this time, the line pressure PL adjusted by the regulator valve 70 and the SLT solenoid 80 is supplied to the hydraulic actuator 42 of the K0 clutch 20. Next, in S120, the engine torque Te is increased at a predetermined gradient (return to the engine torque reduction). Next, in step S130, it is determined whether the engine torque Te is equal to or greater than a preset threshold value α3. The threshold value α3 is determined in advance by experiment or design, and is set to the lower limit value of the engine torque Te at which slippage begins to occur in the K0 clutch 20 when the line pressure PL is the minimum pressure specified by design, i.e., when the K0 torque Tk0 of the K0 clutch 20 is the predetermined minimum value Tk0f. If the determination in S130 is negative, the process returns. If the determination in S130 is positive, the process proceeds to S140 to determine whether the accumulated energy amount E calculated by the above-mentioned equation (1) is equal to or greater than the threshold value α2. If the determination in S140 is positive, the process proceeds to S150 to identify an abnormality in the SLT solenoid 80. On the other hand, if the determination in S140 is negative, the process proceeds to S160 to identify an abnormality in the SCKO solenoid 76.

[0070] As described above, this embodiment also makes it possible to identify the solenoid valve in which an abnormality has occurred, and provides the same effects as those of the previous embodiment.

[0071] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention can also be applied to other embodiments.

[0072] For example, in the above-described embodiment, the vehicle 10 is a hybrid vehicle powered by the engine 12 and the electric motor MG, but the present invention is not necessarily limited to this. For example, the vehicle may be powered only by the engine 12, or may be an electric vehicle powered only by the electric motor MG.

[0073] Furthermore, in the above-described embodiment, the K0 clutch 20 interposed between the engine 12 and the electric motor MG is configured to be controllable by the SCK0 solenoid 76 and the SLT solenoid 80, but the present invention is not limited to the K0 clutch 20. In short, the present invention can be applied as appropriate to any clutch interposed in the power transmission path between the power source (engine 12, electric motor MG) and the drive wheels 14.

[0074] Furthermore, in the above-described embodiment, the occurrence of an abnormality was determined based on the rotational speed difference ΔNk0 of the K0 clutch 20, but it is also possible to directly detect the K0 oil pressure PRk0 of the hydraulic oil supplied to the hydraulic actuator 42 of the K0 clutch 20 using a sensor or the like, and determine the occurrence of an abnormality based on the detected K0 oil pressure PRk0.

[0075] Furthermore, in the above-described embodiment, during the recovery transition period of engine torque Te after switching to fail-safe, an abnormality in the SLT solenoid 80 is determined based on the amount of stored energy E, but it is also possible to determine an abnormality in the SLT solenoid 80 based on the rotational speed difference ΔNk0 of the K0 clutch 20.

[0076] It should be noted that the above is merely one embodiment, and the present invention can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0077] 10: Hybrid vehicle (vehicle) 12: Engine (power source) 14: Drive wheel 20:K0 clutch (clutch) 90: Electronic control device (control device) 76: SCK0 Linear solenoid valve (first solenoid) 80: SLT linear solenoid valve (second solenoid) MG: Electric motor (power source) PRk0: K0 oil pressure (clutch engagement pressure) Te: Engine torque (torque of the power source)

Claims

[Claim 1] A vehicle comprising a first solenoid and a second solenoid capable of controlling the engagement pressure of a clutch interposed in a power transmission path between a power source and drive wheels, and a control device that controls the first solenoid and the second solenoid, wherein the control device is configured to control the engagement pressure of the clutch by the first solenoid and the second solenoid under normal conditions, and to control the engagement pressure of the clutch by the second solenoid when slippage of the clutch is detected while the clutch is engaged, The engagement pressure of the clutch when an abnormality occurs in the first solenoid is configured to be higher than the engagement pressure of the clutch when an abnormality occurs in the second solenoid, When slippage of the clutch is detected during engagement of the clutch, the control device assumes that an abnormality has occurred in the first solenoid, reduces the torque of the power source, and switches from a state in which the engagement pressure of the clutch is controlled by the first solenoid to a state in which the engagement pressure of the clutch is controlled by the second solenoid, and then identifies whether an abnormality has occurred in the first solenoid or the second solenoid based on the engagement state of the clutch when the torque of the power source is increased from the state in which the torque has been reduced. A vehicle characterized by:

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