JP7163898B2 - lockup clutch controller - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to suppression of high temperature of hydraulic oil filled in an automatic transmission or the like.

When the temperature of hydraulic oil filled in an automatic transmission, etc. reaches a predetermined cooling start temperature, cooling of the hydraulic oil is started. By correcting the temperature to the low temperature side, even if the hydraulic oil deteriorates and the temperature of the hydraulic oil tends to rise, it is known to suppress the hydraulic oil from becoming high temperature. The hydraulic oil cooling device of Patent Document 1 is one of them. Further, Patent Document 2 describes executing lockup control of a lockup clutch in order to suppress an increase in the temperature of hydraulic oil.

Japanese Patent Application Laid-Open No. 2008-303918 JP-A-11-315915

By the way, since the degree of deterioration of the hydraulic oil varies, the temperature of the hydraulic oil may become high, for example, when the hydraulic oil deteriorates rapidly.

SUMMARY OF THE INVENTION The present invention has been made against the background of the above circumstances, and its object is to prevent the hydraulic oil filled in an automatic transmission or the like of a vehicle from being heated to a high temperature regardless of the change rate of deterioration of the hydraulic oil. To provide a control device capable of suppressing becoming

The gist of the first invention is that: (a) it is provided in a fluid transmission device that transmits power via hydraulic oil, and is capable of connecting and disconnecting between an input-side rotating member and an output-side rotating member of the fluid transmission device; (b) the lockup region of the lockup clutch is expanded as the degree of deterioration of the hydraulic fluid increases.

According to the lockup clutch control device of the first invention, the lockup region of the lockup clutch is expanded as the rate of increase in the degree of deterioration of the hydraulic oil increases. , the lockup control of the lockup clutch for lowering the working oil temperature of the working oil is more likely to be executed. Therefore, even if the hydraulic oil deteriorates, it is possible to appropriately prevent the hydraulic oil temperature from becoming high.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied, and is a diagram illustrating essential parts of a control system for various controls in the vehicle; FIG. 2 is a skeleton diagram for explaining the configuration of the torque converter and the stepped transmission of FIG. 1; 4 is an engagement operation table showing combinations of engagements of engagement devices for achieving each gear stage of the stepped transmission; 2 is a circuit diagram more specifically showing the hydraulic control circuit of FIG. 1; FIG. It is a sectional view for explaining composition of a solenoid valve. FIG. 6 is a diagram showing output characteristics of the solenoid valve of FIG. 5; It is a shift map for determining the shift of the stepped transmission. 4 is an area map for determining whether to change the value of the lockup start temperature for determining whether to execute lockup control, which is composed of the travel distance of the vehicle and the degree of deterioration of the hydraulic oil. FIG. 9 is a diagram showing the relationship between lockup start temperatures that are applied when the region is in region A in the region map of FIG. 8 ; FIG. 9 is a diagram showing the relationship between lockup start temperatures that are applied when it is in region B in the region map of FIG. 8 ; FIG. 9 is a diagram showing the relationship between lockup start temperatures that are applied when the region is in region C in the region map of FIG. 8 ; FIG. 5 is a diagram showing actual results of values obtained by averaging reduction amounts per vehicle for each region when lockup control for lowering hydraulic oil temperature is executed; FIG. 2 is a flow chart for explaining the essential part of the control action of the electronic control unit of FIG. 1, and is a flow chart for explaining the control action for suppressing the working oil temperature of the working oil from becoming high during traveling; FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following examples, the drawings are appropriately simplified or modified, and the dimensional ratios, shapes, etc. of each part are not necessarily drawn accurately.

FIG. 1 is a diagram for explaining a schematic configuration of a vehicle 10 to which the present invention is applied, and is a diagram for explaining main parts of a control system for various controls in the vehicle 10. As shown in FIG. 1, a vehicle 10 includes an engine 12, drive wheels 14, and a vehicle power transmission device 16 (hereinafter referred to as a power transmission device 16) provided in a power transmission path between the engine 12 and the drive wheels 14. It has The power transmission device 16 can transmit power to a torque converter 20, a stepped transmission 22, and a transmission output gear 24, which is an output rotating member of the stepped transmission 22, in a case 18 as a non-rotating member attached to the vehicle body. and a differential device (differential gear device) 28 connected to the reduction gear mechanism 26 so as to be able to transmit power. The power transmission device 16 also includes a pair of left and right drive shafts (axles) 30 connected to a differential device 28 and the like. In the power transmission device 16, power output from the engine 12 (torque and driving force are synonymous unless otherwise distinguished) is transmitted through a torque converter 20, a stepped transmission 22, a reduction gear mechanism 26, a differential device 28, and a drive shaft. 30, etc., to drive wheels 14 in sequence.

The engine 12 is a driving force source for the vehicle 10 and is a known internal combustion engine such as a gasoline engine or a diesel engine. The engine torque Te of the engine 12 is controlled by controlling the operating conditions such as the amount of intake air, the amount of fuel injection, and the ignition timing by an electronic control unit 50, which will be described later.

FIG. 2 is a skeleton diagram for explaining the structures of the torque converter 20 and the stepped transmission 22. As shown in FIG. Note that the torque converter 20, the stepped transmission 22, and the like are configured substantially symmetrically with respect to the rotation axis RC of the transmission input shaft 32 (input shaft 32), which is the input rotating member of the stepped transmission 22. , the lower half of its axis of rotation RC is omitted in FIG.

In FIG. 2, the torque converter 20 is provided to rotate about a rotation axis RC in a power transmission path between the engine 12 and the stepped transmission 22, and pump blades connected to the engine 12 It is a fluid transmission device that includes a wheel 20p, a turbine wheel 20t connected to an input shaft 32, a stator wheel 20s, and the like, and transmits power via hydraulic oil ATF. The input shaft 32 is also a turbine shaft rotationally driven by the turbine wheel 20t. Further, the torque converter 20 is provided with a lockup clutch LC capable of connecting and disconnecting between the pump impeller 20p and the turbine impeller 20t (that is, between the input and output rotating members of the torque converter 20).

The power transmission device 16 also includes a mechanical oil pump 34 connected to the pump impeller 20p. The mechanical oil pump 34 is rotationally driven by the engine 12 to control the shift of the stepped transmission 22, control the operation of the lockup clutch LC, and provide power to each part of the power transmission path of the power transmission device 16. It generates (discharges) working oil pressure that serves as the source pressure for supplying lubricating oil. Hydraulic oil pumped by the mechanical oil pump 34 is supplied as source pressure to a hydraulic control circuit 88 (see FIGS. 1 and 4) provided in the vehicle 10 . The torque converter 20 corresponds to the fluid transmission device of the present invention, the pump impeller 20p corresponds to the input side rotating member of the present invention, and the turbine impeller 20t corresponds to the output side rotating member of the present invention.

The stepped transmission 22 is a stepped automatic transmission that forms part of the power transmission path between the engine 12 and the drive wheels 14, and is connected in series with the engine 12 via the torque converter 20. there is The stepped transmission 22 includes a double-pinion first planetary gear device 36, a single-pinion second planetary gear device 38 and a double-pinion third planetary gear device 40, both of which are Ravigneaux-type. It is a planetary gear type multi-speed transmission on the same axis (on the axis of rotation RC). The stepped transmission 22 includes hydraulic friction engagement devices such as a first clutch C1, a second clutch C2, a third clutch C3, a fourth clutch C4, a first brake B1, and a second brake B2 (hereinafter, particularly If not distinguished, it will be referred to as an engagement device CB).

The engagement device CB is a hydraulic friction engagement device including a multi-plate or single-plate clutch or brake that is pressed by a hydraulic actuator, a band brake that is tightened by a hydraulic actuator, or the like. The engagement device CB has respective hydraulic pressures Pc1, Pc2, Pb1, Pc1, Pc2, Pb1, By changing the respective torque capacities by Pb2 (see FIG. 4), the operating states such as engagement and disengagement are switched.

The first planetary gear device 36 includes a first sun gear S1, a plurality of pairs of first planetary gears P1 that mesh with each other, a first carrier CA1 that supports the first planetary gears P1 so as to be able to rotate and revolve, and the first planetary gears. It has a first ring gear R1 that meshes with the first sun gear S1 via P1. The second planetary gear device 38 includes a second sun gear S2, a second planetary gear P2, a carrier RCA supporting the second planetary gear P2 so as to rotate and revolve, and the second sun gear through the second planetary gear P2. A ring gear RR meshing with S2 is provided. The third planetary gear device 40 includes a third sun gear S3, a plurality of pairs of third planetary gears P3a and P3b that mesh with each other, a carrier RCA that supports the third planetary gears P3a and P3b so that they can rotate and revolve, and a third It has a ring gear RR that meshes with the third sun gear S3 via planetary gears P3a and P3b. In the second planetary gear device 38 and the third planetary gear device 40, the third planetary gear P3b is shared with the second planetary gear P2, and the carrier is configured by a common carrier RCA and the ring gear is a common ring gear. It is a so-called Ravigneau type composed of RR.

In the stepped transmission 22 , the first sun gear S<b>1 is connected to the case 18 . The first carrier CA1 is connected to the input shaft 32 . First carrier CA1 and second sun gear S2 are selectively coupled via a fourth clutch C4. The first ring gear R1 and the third sun gear S3 are selectively connected via the first clutch C1. The first ring gear R1 and the second sun gear S2 are selectively connected via a third clutch C3. The second sun gear S2 is selectively connected to the case 18 via the first brake B1. Carrier RCA is selectively coupled to input shaft 32 via second clutch C2. Carrier RCA is selectively coupled to case 18 via second brake B2. Ring gear RR is connected to transmission output gear 24 .

In the stepped transmission 22, the engagement and disengagement of the engagement device CB are controlled by the electronic control device 50 according to the driver's accelerator operation, the vehicle speed V, etc., so that the gear ratio (gear ratio) γ (= A plurality of gear stages (transmission stages) having different input rotation speed Nin/output rotation speed No) are selectively formed. The stepped transmission 22, for example, as shown in the engagement operation table of FIG. Steps are selectively formed. The input rotation speed Nin is the rotation speed of the input shaft 32, and the output rotation speed No is the rotation speed of the transmission output gear 24. The gear ratio γ of the stepped transmission 22 corresponding to each gear stage is the gear ratio of the first planetary gear device 36, the second planetary gear device 38, and the third planetary gear device 40 (=number of teeth of sun gear/ring gear number of teeth) is appropriately determined by ρ1, ρ2, and ρ3. The gear ratio γ of the first gear "1st" is the largest, and becomes smaller as the vehicle speed increases (eighth gear "8th").

The engagement operation table in FIG. 3 summarizes the relationship between each gear stage formed in the stepped transmission 22 and each operation state of the engagement device CB. Each represents liberation. As shown in FIG. 3, in the forward gear stage, the first gear stage "1st" is established by engagement of the first clutch C1 and the second brake B2. The engagement of the first clutch C1 and the first brake B1 establishes the second gear "2nd". The engagement of the first clutch C1 and the third clutch C3 establishes the third speed "3rd". The engagement of the first clutch C1 and the fourth clutch C4 establishes the fourth gear "4th". The engagement of the first clutch C1 and the second clutch C2 establishes the fifth gear "5th". The sixth gear "6th" is established by engagement of the second clutch C2 and the fourth clutch C4. The seventh speed "7th" is established by the engagement of the second clutch C2 and the third clutch C3. The eighth gear "8th" is established by engagement of the second clutch C2 and the first brake B1. Further, the reverse gear "Rev" is established by the engagement of the third clutch C3 and the second brake B2. In addition, by disengaging all of the engagement devices CB, the stepped transmission 22 is brought into a neutral state in which none of the gear stages is formed (that is, a neutral state in which power transmission is interrupted).

Returning to FIG. 1, the vehicle 10 includes an electronic control device 50 (control device in the present invention) as a controller including control devices of the vehicle 10 related to control of the engine 12, the stepped transmission 22, and the like. FIG. 1 is a diagram showing an input/output system of the electronic control unit 50, and is a functional block diagram for explaining the main control functions of the electronic control unit 50. As shown in FIG. The electronic control unit 50 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, and an input/output interface. Various controls of the vehicle 10 are executed by performing signal processing. The electronic control unit 50 is configured separately for engine control, shift control, etc., as required.

The electronic control unit 50 includes various sensors provided in the vehicle 10 (for example, an engine rotation speed sensor 52, an input rotation speed sensor 54, an output rotation speed sensor 56, an accelerator opening sensor 58, a throttle valve opening sensor 60, a brake Pedal sensor 62, steering sensor 64, driver state sensor 66, G sensor 68, yaw rate sensor 70, oil temperature sensor 72, vehicle surrounding information sensor 74, vehicle position sensor 76, external network communication antenna 78, navigation system 80, driving assistance Various signals based on values detected by the set switch group 82, shift position sensor 84, etc. (for example, the input rotation speed Ni of the transmission input shaft 32 corresponding to the engine rotation speed Ne, the turbine shaft rotation speed Nt, and the vehicle speed V) Output rotation speed No, accelerator opening θacc as the driver's acceleration operation amount representing the magnitude of the driver's acceleration operation, throttle valve opening θth being the opening of the electronic throttle valve, brake for operating the wheel brake A brake-on signal Bon, which is a signal indicating that the pedal is being operated by the driver, a brake operation amount Bra, which corresponds to the force applied to the brake pedal and indicates the magnitude of the brake pedal depression operation by the driver, steering angle θsw and steering direction Dsw of the steering wheel, a steering-on signal SWon which is a signal indicating that the steering wheel is being gripped by the driver, a driver state signal Drv which is a signal indicating the state of the driver, and the vehicle 10 longitudinal acceleration Gx of the vehicle 10, lateral acceleration Gy of the vehicle 10, yaw rate Ryaw that is the rotational angular velocity of the vehicle 10 about the vertical axis, hydraulic oil temperature THoil that is the temperature of the hydraulic oil ATF, vehicle peripheral information Iard, position information Ivp, communication signal Scom , navigation information Inavi, driving support setting signal Sset, which is a signal indicating settings by the driver in driving support control such as automatic driving control and cruise control, operation position POSsh of the shift lever provided in the vehicle 10, etc.) are supplied respectively. be done.

The driver's acceleration operation amount representing the magnitude of the driver's acceleration operation is, for example, an accelerator operation amount that is an operation amount of an accelerator operation member such as an accelerator pedal, and is an output request amount of the vehicle 10 by the driver. In addition to the accelerator opening .theta.acc, the throttle valve opening .theta.th and the like can also be used as the driver's requested output amount.

The driver state sensor 66 includes at least one of, for example, a camera that captures the driver's expression and pupils, and a biometric information sensor that detects the biometric information of the driver. , eye movement, face movement, and heart rate.

The vehicle surrounding information sensor 74 includes at least one of, for example, a lidar, a radar, and an in-vehicle camera, and directly obtains information on the road on which the vehicle is traveling and information on objects existing around the vehicle. The lidar is, for example, a plurality of lidars that respectively detect an object in front of the vehicle 10, an object on the side, an object behind the vehicle 10, or one lidar that detects objects all around the vehicle 10, and the detected object is output as vehicle peripheral information Iard. The radar is, for example, a plurality of radars that respectively detect an object in front of the vehicle 10, an object near the front, an object near the rear, etc., and outputs object information about the detected object as vehicle surrounding information Iard. The object information obtained by the lidar or radar includes the distance and direction of the detected object from the vehicle 10 . The vehicle-mounted camera is, for example, a monocular camera or a stereo camera that captures an image of the front and rear of the vehicle 10, and outputs image information as vehicle peripheral information Iard. This imaging information includes information such as lane lines on the road, signs on the road, parking spaces, and other vehicles 200, pedestrians, and obstacles on the road. The other vehicle 200 is a vehicle different from the vehicle 10 such as the other vehicles 200 a and 200 b and basically has the same functions as the vehicle 10 .

Vehicle position sensor 76 includes a GPS antenna and the like. The position information Ivp includes vehicle position information indicating the position of the vehicle 10 on the ground or map based on GPS signals (trajectory signals) transmitted by GPS (Global Positioning System) satellites.

A navigation system 80 is a known navigation system having a display, a speaker, and the like. The navigation system 80 identifies the position of the vehicle on pre-stored map data based on the position information Ivp. The navigation system 80 displays the vehicle position on the map displayed on the display. When a destination is input, the navigation system 80 calculates a travel route from the departure point to the destination, and instructs the driver on the travel route through a display, speaker, or the like. The navigation information Inavi includes map information such as road information and facility information based on map data pre-stored in the navigation system 80, for example. The road information includes information such as types of roads such as urban roads, suburban roads, mountain roads, highways, road junctions and confluences, road gradients, and vehicle speed limits. The facility information includes information such as supermarkets, stores, restaurants, parking lots, parks, bases for repairing the vehicle 10, homes, service areas on highways, and the like, locations, and names of bases. The service area is, for example, an expressway, and is a base with facilities such as parking, dining, and refueling.

The driving support setting switch group 82 includes an automatic driving selection switch for executing automatic driving control, a cruise switch for executing cruise control, a switch for setting the vehicle speed in cruise control, and a vehicle distance to the preceding vehicle in cruise control. It includes a switch for setting the lane, a switch for executing lane keep control to maintain the set lane, and the like.

The communication signal Scom is, for example, road traffic information transmitted and received with a center, which is an external device such as a road traffic information communication system, and/or communication with another vehicle near the vehicle 10 without going through the center. It includes vehicle-to-vehicle communication information directly sent and received between vehicles. The road traffic information includes, for example, information on road congestion, accidents, construction work, required time, parking lots, and the like. The vehicle-to-vehicle communication information includes, for example, vehicle information, travel information, and traffic environment information. The vehicle information includes, for example, information indicating vehicle types such as passenger cars, trucks, and two-wheeled vehicles. The traveling information includes, for example, vehicle speed V, position information, brake pedal operation information, turn signal lamp blinking information, hazard lamp blinking information, and the like. The traffic environment information includes, for example, information such as road congestion and construction.

From the electronic control device 50, to each device (eg, engine control device 86, hydraulic control circuit 88, external network communication antenna 78, wheel brake device 90, steering device 92, information dissemination device 94, etc.) provided in the vehicle 10 Various command signals (for example, an engine control command signal Se for controlling the engine 12, a hydraulic control command signal Sat for controlling the operating states of the engagement device CB and the lockup clutch LC, a communication signal Scom, braking torque by the wheel brake brake control command signal Sbra for controlling the steering control command signal Sste for controlling the steering of the wheels (especially the front wheels), information notification control command signal Sinf for warning and informing the driver, etc.) output respectively. The hydraulic control command signal Sat is also a hydraulic control command signal for controlling the shift of the stepped transmission 22. For example, the hydraulic pressures Pc1, Pc2, Pc3, Pc4, Pc4, Pc1, Pc2, Pc3, Pc4, This is a command signal for driving the solenoid valves SL1-SL6, etc. (see FIG. 4, which will be described later) for regulating Pb1 and Pb2. Further, the hydraulic control command signal Sat is also a hydraulic control command signal for controlling the operating state of the lockup clutch LC. is a command signal for driving the The electronic control unit 50 sets hydraulic pressure command values corresponding to the respective hydraulic pressure values Pc1, Pc2, Pc3, Pc4, Pb1, Pb2, and Plu, and controls the drive current or drive voltage according to the hydraulic pressure command values to the hydraulic control circuit 88. Output to

The wheel brake device 90 is a brake device that applies braking torque to wheels by wheel brakes. The wheel brake device 90 supplies brake hydraulic pressure to a wheel cylinder provided in the wheel brake in response to, for example, a brake pedal stepping operation by the driver. In the wheel brake device 90, normally, the master cylinder hydraulic pressure generated from the brake master cylinder and corresponding to the brake operation amount Bra is supplied to the wheel cylinders as brake hydraulic pressure. On the other hand, in the wheel brake device 90, for example, during ABS control, sideslip suppression control, vehicle speed control, automatic driving control, etc., the braking torque is generated by the wheel brake, so the brake hydraulic pressure required for each control is not sufficient. Supplied to the wheel cylinder. The wheels are drive wheels 14 and driven wheels (not shown).

The steering device 92 provides the steering system of the vehicle 10 with assist torque corresponding to, for example, the vehicle speed V, the steering angle θsw, the steering direction Dsw, the yaw rate Ryaw, and the like. The steering device 92 applies torque for controlling the steering of the front wheels to the steering system of the vehicle 10, for example, during automatic driving control.

The information dissemination device 94 is a device that warns or notifies the driver when, for example, some component related to running of the vehicle 10 breaks down or the function of the component deteriorates. The information dissemination device 94 is, for example, a display device such as a monitor, display, or alarm lamp, and/or a sound output device such as a speaker or buzzer. The display device is a device that gives a visual warning or notification to the driver. A sound output device is a device that gives an audible warning or notification to a driver.

FIG. 4 is a circuit diagram showing a main part of a hydraulic control circuit 88 that functions as a hydraulic control device for solenoid valves SL1-SL7 that control the actuation of the engagement device CB and the lockup clutch LC. 4, the hydraulic control circuit 88 includes a hydraulic supply device 96 and solenoid valves SL1-SL7.

Hydraulic pressure is supplied to the hydraulic pressure supply device 96 from the mechanical oil pump 34 and an electric oil pump 100 connected via a check valve 98 to an oil passage for supplying the hydraulic pressure generated by the mechanical oil pump 34 . be. The hydraulic pressure supply device 96 includes a primary regulator valve 102 that regulates the first line hydraulic pressure PL using the hydraulic pressure generated by the mechanical oil pump 34 and the electric oil pump 100 as source pressure, and the hydraulic pressure discharged from the primary regulator valve 102. A secondary regulator valve 104 for regulating the second line oil pressure PL2 by using A solenoid valve SLT that supplies a signal pressure Pslt to 104, a modulator valve 106 that adjusts the modulator hydraulic pressure PM to a constant value using the first line hydraulic pressure PL as the source pressure, and a shift lever 108 that is mechanically interlocked with the switching operation. and a manual valve 110 for switching the oil passage. When the shift lever 108 is in the D operation position or the M operation position, the manual valve 110 outputs the input first line oil pressure PL as forward oil pressure (D range pressure, drive oil pressure) PD, and the shift lever 108 is in the R operation. When in the position, the input first line oil pressure PL is output as the reverse oil pressure (R range pressure, reverse oil pressure) PR. Further, when the shift lever 108 is in the N operation position or the P operation position, the manual valve 110 cuts off the hydraulic pressure output and guides the drive hydraulic pressure PD and the reverse hydraulic pressure PR to the discharge side. Thus, the hydraulic pressure supply device 96 outputs the first line hydraulic pressure PL, the second line hydraulic pressure PL2, the modulator hydraulic pressure PM, the drive hydraulic pressure PD, and the reverse hydraulic pressure PR.

Hydraulic actuators ACT1, ACT2 and ACT4 of clutches C1, C2 and C4 are supplied with hydraulic pressures Pc1, Pc2 and Pc4 regulated by solenoid valves SL1, SL2 and SL4 using drive hydraulic pressure PD as a source pressure. Hydraulic actuators ACT3, ACT5 and ACT6 for the clutch C3 and brakes B1 and B2 are supplied with hydraulic pressures Pc3, Pb1 and Pb2 regulated by solenoid valves SL3, SL5 and SL6 using the first line hydraulic pressure PL as the source pressure. supplied.

The lockup clutch LC is supplied with the hydraulic pressure Plu regulated by the solenoid valve SL7 and the second line hydraulic pressure PL2 regulated by the secondary regulator valve 104 . The lockup clutch LC has an engagement-side oil chamber and a release-side oil chamber. The operating state of the up clutch LC is controlled. For example, when the oil pressure Pon of the engagement side oil chamber and the oil pressure Poff of the release side oil chamber are the same, the differential pressure ΔP becomes zero. At this time, the lockup clutch LC is released. On the other hand, when the hydraulic pressure Pon of the engagement side oil chamber is higher than the hydraulic pressure Poff of the disengagement side oil chamber, the differential pressure ΔP becomes greater than zero. At this time, the lockup clutch LC is half-engaged or fully-engaged according to the magnitude of the differential pressure ΔP. The differential pressure .DELTA.P is controlled by the hydraulic pressure Plu regulated by the solenoid valve SL7. For example, the higher the hydraulic pressure Plu, the higher the differential pressure .DELTA.P.

Each of the solenoid valves SL1-SL7 has basically the same structure, and is independently energized, de-energized, and current-controlled by an electronic control device 50 corresponding to the function of the control device. Pc3, Pc4, Pb1, Pb2 and Plu are independently regulated. The hydraulic control circuit 88 is provided with a shuttle valve 112, and the hydraulic actuator ACT6 of the brake B2 is supplied via the shuttle valve 112 with the hydraulic pressure supplied from either the hydraulic pressure Pb2 or the reverse hydraulic pressure PR. .

FIG. 5 is a cross-sectional view for explaining the configuration of the solenoid valves SL1-SL7. All of the solenoid valves SL1 to SL7 basically have the same configuration, so the solenoid valve SL1 is shown as an example.

The solenoid valve SL1 includes a solenoid 122 that converts electrical energy into driving force when energized, and a pressure regulator 124 that drives the solenoid 122 to regulate the first line oil pressure PL to generate the C1 oil pressure Pc1. there is The solenoid 122 includes a cylindrical winding core 126, a coil 128 having a conductive wire wound around the outer circumference of the winding core 126, a core 130 provided movably in the axial direction inside the winding core 126, and a core 130. A plunger 132 fixed at the end opposite to the pressure regulating portion 124, a case 134 for storing the winding core 126, the coil 128, the core 130, and the plunger 132, and the opening of the case 134 and a cover 136 .

The pressure regulating portion 124 includes a sleeve 138 fitted to the case 134, a spool valve element 140 provided axially movably inside the sleeve 138, and biasing the spool valve element 140 toward the solenoid 122 side. A spring 142 is provided. The solenoid 122 side end of the spool valve element 140 is brought into contact with the pressure regulating section 124 side end of the core 130 . In the solenoid valve SL1 configured as described above, when a drive current is applied to the coil 128, the plunger 132 is moved in the same axial direction as the core 130 and the spool valve element 140 according to the magnitude of the drive current. Accordingly, the core 130 and the spool valve element 140 are moved in the same direction. As a result, the flow rate of hydraulic oil ATF input from the input port 144 and the flow rate of hydraulic oil ATF discharged from the drain port 146 are adjusted. The first line oil pressure PL input to the input port 144 is regulated according to the valve characteristics of the linear solenoid valve SL1, and the C1 oil pressure Pc1 after pressure adjustment is output from the output port 148.

Returning to FIG. 1, the vehicle 10 further includes a transceiver 150, a first gateway ECU 152, a second gateway ECU 154, a connector 156, and the like.

The transmitter/receiver 150 is a device that exists separately from the vehicle 10 and communicates with the server 210 that is an external device that is separate from the vehicle 10 . Server 210 is a system on the network outside vehicle 10 . The server 210 receives, processes, analyzes, accumulates, and provides various types of information such as vehicle state information and vehicle phenomenon information. Server 210 transmits and receives various types of information to and from other vehicle 200 in the same manner as with vehicle 10 . The transmitter/receiver 150 may have a function of directly communicating with another vehicle 200 in the vicinity of the vehicle 10 without going through the server 210 . The vehicle state information is, for example, information indicating a running state related to running of the vehicle 10 detected by various sensors or the like, that is, an operating state of the vehicle 10 . The running state includes, for example, accelerator opening θacc, vehicle speed V, and the like. The vehicle phenomenon information is, for example, information indicating a phenomenon occurring in the vehicle 10 . This phenomenon includes, for example, sound in the vehicle detected by a microphone (not shown), that is, sound pressure, and vibration sensed by the passenger detected by the G sensor 68 . Note that wireless communication may be performed with the server 210 via the external network communication antenna 78 .

The first gateway ECU 152 and the second gateway ECU 154 each have a hardware configuration similar to that of the electronic control unit 50, and are for rewriting programs and/or data stored in a rewritable ROM in the electronic control unit 50, for example. It is a relay device provided in. The first gateway ECU 152 is connected to the transmitter/receiver 150, and uses wireless communication between the transmitter/receiver 150 and the server 210, for example, to rewrite the program stored in the ROM in the electronic control unit 50. It is. The server 210 functions as a software distribution center that distributes programs for rewriting. The second gateway ECU 154 can be mechanically connected via a connector 156 to an external rewriting device 220, which is an external device separate from the vehicle 10. For example, using the external rewriting device 220, the electronic control device It is for rewriting the program stored in the ROM in 50 .

In order to realize various controls in the vehicle 10, the electronic control unit 50 includes an engine control unit 160 functioning as engine control means, a shift control unit 162 functioning as shift control means, and a lockup control function functioning as lockup control means. A portion 164 is functionally provided.

The engine control unit 160 calculates the required driving force Fdem by applying the driving force-related values such as the accelerator opening θacc and the vehicle speed V to a driving force map, which is a relation obtained experimentally or by design in advance and stored. calculate. Engine control unit 160 sets target engine torque Tetgt at which required driving force Fdem is obtained, and outputs to engine control device 86 a command to control engine 12 so as to obtain target engine torque Tetgt.

The shift control unit 162 determines the shift of the stepped transmission 22 using a shift map such as that shown in FIG. , and outputs a hydraulic control command signal Sat for executing shift control of the stepped transmission 22 to the hydraulic control circuit 88 as required. The shift map is a predetermined relationship having a shift line for judging the shift of the stepped transmission 22 on two-dimensional coordinates having the vehicle speed V and the required driving force Frdem as variables, for example. Here, instead of the vehicle speed V, the output rotation speed No may be used, and instead of the required driving force Frdem, the required driving torque Trdem, the accelerator opening θacc, the throttle valve opening θth, etc. may be used. . Each shift line in the shift map is an upshift line for determining an upshift as indicated by a solid line, and a downshift line for determining a downshift as indicated by a broken line.

The lock-up control unit 164 stores the actual vehicle speed V and the accelerator opening degree in an operation region map (relationship map) composed of vehicle speed V, accelerator opening degree θacc, and the like that determine the predetermined operating state of the lock-up clutch LC. By applying θacc, the operating state of the lockup clutch LC is determined, and the lockup clutch LC is controlled to that operating state. Thus, the lockup clutch LC is controlled to be lockup on (completely engaged), flex lockup (slip engagement), or lockup off (released) according to the running state of the vehicle 10. .

For example, when the running state of the vehicle 10 enters a lockup-on region in which the lockup clutch LC is lockup-on (completely engaged) in the operation region map, the lockup control unit 164 controls the lockup clutch LC to lock up (completely engage). The operating state of the hydraulic control circuit 88 is controlled so that the pressure ΔP (Pon-Poff) is maximized and the lockup clutch LC is fully engaged. Further, the lock-up control unit 164 controls that when the running state of the vehicle 10 enters the lock-up OFF region where the lock-up clutch LC is released in the operating region map, the differential pressure ΔP (Pon-Poff) of the lock-up clutch LC becomes The operating state of the hydraulic control circuit 88 is controlled so that it becomes zero. Further, when the running state of the vehicle 10 enters the flex lockup region in which the lockup clutch is slip-engaged in the operating region map, the lockup control unit 164 controls the slip amount ΔN (=Ne-Nt) of the lockup clutch LC. ) becomes a preset slip amount ΔN. Specifically, the lockup control unit 164 feedback-controls the differential pressure ΔP so that the slippage amount ΔN (=Ne−Nt) of the lockup clutch LC becomes a predetermined slippage amount ΔN.

Further, the lockup control unit 164 fully engages the lockup clutch LC when the hydraulic oil temperature THoil of the hydraulic oil ATF becomes equal to or higher than the preset lockup start temperature α, thereby operating the hydraulic oil ATF. Decrease the oil temperature THoil. When the hydraulic oil temperature THoil of the hydraulic oil ATF reaches or exceeds the lockup start temperature α, the lockup clutch LC is fully engaged, so that the pump impeller 20p and the turbine impeller 20t of the torque converter 20 rotate integrally. Let me. As a result, the amount of heat generated by the hydraulic oil ATF in the torque converter 20 is reduced, so that the hydraulic oil temperature THoil of the hydraulic oil ATF is lowered. The lock-up start temperature α is obtained experimentally or by design in advance, and is a limit of the working oil temperature THoil at which the operation of the stepped transmission 22 and the like is restricted as the working oil temperature THoil of the working oil ATF increases. It is set to a value close to the temperature and lower than the limit temperature. That is, the lockup start temperature α is set to a value at which the hydraulic oil temperature THoil of the hydraulic oil ATF is lowered and does not reach the limit temperature due to the execution of the lockup control.

By the way, it is known that the heat load applied to the hydraulic oil ATF increases cumulatively in proportion to the traveling distance L of the vehicle 10, and the hydraulic oil ATF deteriorates. When the hydraulic oil ATF deteriorates, the hydraulic oil temperature THoil of the hydraulic oil ATF tends to increase. There is a risk that the hydraulic oil temperature THoil of the hydraulic oil ATF will not drop in time and the hydraulic oil temperature THoil will reach the limit temperature. On the other hand, the electronic control unit 50 is based on the travel history of the vehicle 10, the deterioration degree RATF of the hydraulic oil ATF, which is the degree of deterioration of the hydraulic oil ATF, and the increase rate ΔRATF of the deterioration degree RATF of the hydraulic oil ATF. to change the lockup start temperature α, and execute lockup control based on the changed lockup start temperature α, thereby appropriately lowering the hydraulic oil temperature THoil.

In order to realize the above-described control function, the electronic control unit 50 includes a travel history detection unit 166 that functions as travel history detection means for detecting the travel history of the vehicle 10, and a deterioration degree RATF that presumably calculates the deterioration degree RATF of the hydraulic oil ATF. a deterioration degree calculation unit 168 functioning as a deterioration degree calculation means; a deterioration degree increase ratio calculation unit 170 functioning as a deterioration degree increase ratio calculation means for calculating an increase rate ΔRATF of the deterioration degree RATF of the hydraulic oil ATF; and a temperature threshold changing unit 172 functioning as temperature threshold changing means for changing the temperature threshold.

Travel history detection unit 166 detects, as a representative value of the travel history of vehicle 10, travel distance L of vehicle 10 based on the point in time when the hydraulic oil ATF was replaced.

The deterioration degree calculation unit 168 calculates the deterioration degree RATF of the hydraulic oil ATF based on the time when the hydraulic oil ATF is replaced. The deterioration degree calculation unit 168 stores the temperature history of the working oil temperature THoil of the working oil ATF detected by the oil temperature sensor 72 at any time. Further, the deterioration degree calculation unit 168 stores a relational diagram (not shown) showing the relationship between the elapsed time (cumulative time) at a preset reference temperature and the deterioration degree RATF. In the relationship diagram, the degree of deterioration RATF tends to increase as the elapsed time at the reference temperature increases.

Further, the deterioration degree calculation unit 168 stores a relational expression for converting the elapsed time when the hydraulic oil temperature THoil of the hydraulic oil ATF is at a temperature other than the reference temperature to the elapsed time at the reference temperature. By applying the above relational expression to the temperature history of warm THoil, the elapsed time at each hydraulic oil temperature THoil is converted into the elapsed time when the reference temperature is used, and the elapsed time at each hydraulic oil temperature THoil is converted to the passage of the reference temperature. Calculate the elapsed time of the hydraulic oil ATF at the reference temperature by accumulating the elapsed time converted to time. Further, the deterioration degree calculation unit 168 calculates the deterioration degree RATF of the hydraulic oil ATF by applying the calculated elapsed time to the relationship between the elapsed time at the reference temperature and the deterioration degree RATF.

The deterioration degree increase ratio calculation unit 170 calculates an increase ratio ΔRATF of the deterioration degree RATF based on the deterioration degree RATF of the hydraulic oil ATF which is calculated as needed. The deterioration degree increase ratio calculation unit 170 calculates an increase ratio ΔRATF of the deterioration degree RATF that indicates the transition of the deterioration degree RATF of the hydraulic oil ATF by time differentiating the deterioration degree RATF of the hydraulic oil ATF that is calculated as needed for each calculation cycle. calculate.

A temperature threshold change unit 172 determines a lockup threshold value for executing lockup control for lowering the hydraulic oil temperature THoil of the hydraulic oil ATF based on the travel distance L of the vehicle 10 and the degree of deterioration RATF of the hydraulic oil ATF. It is determined whether to change the starting temperature α to the lower temperature side. The temperature threshold change unit 172 applies the current travel distance L and the deterioration degree RATF from the area map configured by the travel distance L of the vehicle 10 and the deterioration degree RATF of the hydraulic oil ATF as shown in FIG. is determined, and whether or not to change the lockup start temperature α is determined according to the determined region.

As shown in the area map of FIG. 8, the area defined by the travel distance L and the degree of deterioration RATF is divided into three areas, area A to area C. As shown in FIG. In FIG. 8, a straight line M extending obliquely is a boundary line for determining whether to change the lockup start temperature α to the lower temperature side, which is determined based on the travel distance L and the degree of deterioration RATF. That is, the straight line M is a set of threshold values of the degree of deterioration RATF of the hydraulic oil ATF for determining whether the lockup start temperature α set for each travel distance L is changed. This straight line M divides the area map into two areas. Furthermore, the area located on the lower right side of the straight line M is divided into two areas (area A and area B) with a predetermined degree of deterioration RATF as a boundary.

Regarding the region A, the deterioration degree RATF is lower than the deterioration degree RATF threshold value (straight line M) for judging the change of the lockup start temperature α with respect to the traveling distance L of the vehicle 10, and the hydraulic oil temperature THoil of the hydraulic oil ATF This corresponds to a region in which it is not necessary to change the lockup start temperature α, which is the determination threshold value for executing lockup control for lowering the hydraulic oil temperature THoil when is high, to the lower temperature side. Region B corresponds to a region in which the degree of deterioration RATF is lower than the threshold value (straight line M) for judging whether to change the lockup start temperature α with respect to the traveling distance L of the vehicle 10, but the degree of deterioration RATF is relatively high. ing. Regarding the region C, the deterioration degree RATF is higher than the threshold value (straight line M) of the deterioration degree RATF for determining the change of the lockup start temperature α with respect to the traveling distance L of the vehicle 10, and the lockup start temperature α is on the low temperature side. Addresses areas where changes to

The temperature threshold changing unit 172 determines that it is not necessary to change the lockup start temperature α when it is in the region A in the region map of FIG. 8 . FIG. 9 shows the lockup start temperature α when in region A in FIG. In FIG. 9, the horizontal axis indicates the rate of increase ΔRATF of the degree of deterioration RATF of the hydraulic oil ATF, and the vertical axis indicates the value of the lockup start temperature α, which is the determination threshold value for executing the lockup control. As shown in FIG. 9, in the region A in the region map of FIG. 8, the lockup start temperature α is a constant value regardless of the rate of increase ΔRATF of the degree of deterioration RATF. That is, the lockup start temperature α is not changed regardless of the rate of increase ΔRATF of the degree of deterioration RATF. Referring to FIG. 9, the lockup clutch LC is fully engaged when the operating oil temperature THoil is equal to or higher than the lockup start temperature α. Further, in a region where the operating oil temperature THoil is lower than the lockup start temperature α, the lockup clutch LC is released or slip-engaged (flex lockup).

The temperature threshold changing unit 172 changes the lockup start temperature α according to the rate of increase ΔRATF of the degree of deterioration RATF when it is in the region B in the region map of FIG. 8 . FIG. 10 shows the lockup start temperature α in region B in FIG. In FIG. 10, the horizontal axis indicates the rate of increase ΔRATF of the degree of deterioration RATF of the hydraulic oil ATF, and the vertical axis indicates the value of the lockup start temperature α, which is the determination threshold for executing the lockup control. As shown in FIG. 10, when the rate of increase .DELTA.RATF of the degree of deterioration RATF of the hydraulic oil ATF exceeds a predetermined value, the lockup start temperature .alpha. decreases as the rate of increase .DELTA.RATF increases. That is, when the rate of increase ΔRATF of the deterioration degree RATF of the hydraulic oil ATF exceeds a predetermined value, the lockup start temperature α decreases as the rate of increase ΔRATF increases. As the value increases, the lockup ON region of the lockup clutch LC is expanded. Therefore, the lockup control for lowering the hydraulic oil temperature THoil of the hydraulic oil ATF is facilitated. The rate of increase ΔRATF of the degree of deterioration RATF at which the lockup start temperature α begins to decrease and the slope of decrease of the degree of lockup start temperature α are obtained experimentally or by design in advance. By properly executing the control, the hydraulic oil temperature THoil of the hydraulic oil ATF is set to a value that does not reach the limit temperature.

Temperature threshold change unit 172, when in region C in the region map of FIG. Change to a lower value. FIG. 10 shows the lockup start temperature α in region C in FIG. In FIG. 10, the horizontal axis indicates the rate of increase ΔRATF of the degree of deterioration RATF of the hydraulic oil ATF, and the vertical axis indicates the value of the lockup start temperature α, which is the determination threshold for executing the lockup control. In FIG. 10, the solid line indicates the lockup start temperature α in region C. In FIG. A dashed line indicates the lockup start temperature α in the region A as a comparison target. As shown in FIG. 10, the lockup start temperature α in region C is lower than the lockup start temperature α in region A indicated by the dashed line by a predetermined value regardless of the rate of increase ΔRATF of the degree of deterioration RATF. has been edited. Therefore, in the region C, the lockup ON region of the lockup clutch LC is expanded compared to the region A, and the lockup control is easily executed. The amount of decrease in the lockup start temperature α is determined experimentally or by design in advance, and by expanding the lockup region of the lockup control, the hydraulic oil temperature THoil of the hydraulic oil ATF reaches the limit temperature. set to a value that disappears.

Based on the lockup start temperature α changed by the temperature threshold changer 172, the lockup control unit 164 determines whether to execute lockup control for lowering the hydraulic oil temperature THoil. As described above, in the region B, the lockup start temperature α is changed to a lower temperature side as the increase rate ΔRATF of the deterioration degree RATF of the hydraulic oil ATF is larger, and in the region C, the lockup start temperature α of the region A Since the lockup start temperature α is lower than , the lockup region in which the lockup control of the lockup clutch LC is executed is expanded, and the lockup control is easily executed. As a result, the amount of heat generated in the torque converter 20 is reduced, and the operating oil temperature THoil is lowered.

When the temperature threshold change unit 172 lowers the lockup start temperature α, the temperature threshold change unit 172 may also lower the lockup start temperature α step by step at predetermined time intervals with respect to the target lockup start temperature α. can. In this way, by lowering the lockup start temperature α in stages, discomfort caused by a sudden increase in the frequency of lockup control is alleviated.

In addition, there are differences in the ease with which the hydraulic oil ATF deteriorates depending on the region. On the other hand, for example, the server 210 lowers the lockup start temperature α when executing lockup control for lowering the hydraulic oil temperature THoil for each region from each of a plurality of vehicles including the other vehicle 200. The amount of decrease or the number of times of decrease is acquired, and the average value obtained by averaging the amount of decrease or the number of times of decrease per vehicle is stored as big data as a track record of executing lockup control. FIG. 12 shows actual values obtained by averaging the amount of decrease in the lockup start temperature α to the amount of decrease per vehicle for each region. For example, in areas A1 and A4, the amount of decrease in the lockup start temperature α is large. The electronic control unit 50 acquires the results for each region from the server 210 as necessary. When the vehicle 10 is traveling in an area where the hydraulic oil ATF is likely to deteriorate, the temperature threshold changing unit 172 applies the relationship shown in FIG. The lock-up start temperature α is made easier to lower, or the lock-up start temperature α is lowered in advance. From this, in areas where the hydraulic oil ATF is likely to deteriorate, the lockup start temperature α is likely to decrease, or the lockup start temperature α is decreased in advance, resulting in the lockup control being executed. The ON region (temperature region) is expanded, and the hydraulic oil temperature THoil is effectively lowered. Areas where the hydraulic oil ATF is likely to deteriorate are determined by whether or not the amount of decrease or the number of times of decrease of the lockup start temperature α for each area exceeds, for example, a predetermined value β indicated by the dashed line in FIG. 12 .

FIG. 13 is a flow chart for explaining the main part of the control operation of the electronic control unit 50. Even if the hydraulic oil ATF deteriorates, the hydraulic oil temperature THoil of the hydraulic oil ATF is suppressed from becoming high during running. 4 is a flow chart for explaining control operation; This flowchart is repeatedly executed while the vehicle 10 is running.

First, in step ST1 (hereinafter, the step is omitted) corresponding to the control function of the travel history detection unit 166, the travel distance L of the vehicle 10 based on the time when the hydraulic oil ATF was replaced is detected. Next, in ST2 corresponding to the control function of the deterioration degree calculator 168, the deterioration degree RATF of the hydraulic oil ATF is calculated. Further, in ST3 corresponding to the control function of the deterioration degree increase ratio calculator 170, the deterioration degree RATF increase ratio ΔRATF of the deterioration degree RATF is calculated from the deterioration degree RATF of the hydraulic oil ATF which is calculated as needed. Next, in ST4 corresponding to the control operation of the temperature threshold change unit 172, the lockup start temperature α, which is the temperature threshold for determining the execution of the lockup control, is based on the travel distance L and the degree of deterioration RATF of the hydraulic oil ATF. is changed to the low temperature side. Specifically, in the area map of FIG. 8, it is determined whether the area is in area B or area C. FIG. If ST4 is negative, the routine is terminated. On the other hand, if ST4 is affirmative, in ST5 corresponding to the control operation of the temperature threshold value changing unit 172, if it is in region B in FIG. is changed to 8, the lockup start temperature α is changed to the low temperature side based on the relationship shown in FIG. Since both of these are changed in the direction in which the lockup start temperature α is lowered, the lockup region in which the lockup control is executed is expanded, and the lockup control is easily executed. In ST6 corresponding to the control function of the lockup control unit 164, it is determined whether or not to execute lockup control based on the lockup start temperature α, which is the temperature threshold changed in ST5. Up control is executed.

As described above, according to the present embodiment, the larger the rate of increase ΔRATF of the deterioration degree RATF of the hydraulic oil ATF, the larger the lockup region of the lockup clutch LC. When ΔRATF is large, the working oil temperature THoil tends to increase, whereas the lockup control of the lockup clutch LC for lowering the working oil temperature THoil of the working oil ATF tends to be executed. Therefore, even when the hydraulic oil ATF deteriorates, it is possible to appropriately prevent the hydraulic oil temperature THoil of the hydraulic oil ATF from becoming high.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is also applicable to other aspects.

For example, in the above-described embodiment, when the hydraulic oil temperature THoil of the hydraulic oil ATF reaches the lockup start temperature α, it was determined whether or not the lockup clutch LC should be fully engaged. It is not limited to full engagement of the clutch LC. For example, whether or not the lockup clutch LC is switched from the released state to the slip engagement (flex lockup) is determined based on whether the hydraulic oil temperature THoil of the hydraulic oil ATF reaches the lockup start temperature α. I do not care. Even when the lockup clutch LC is switched from disengaged to slip-engaged, the difference in rotational speed between the pump impeller 20p and the turbine impeller 20t in the torque converter 20 becomes small, so that the hydraulic fluid ATF generates heat. is reduced, and an increase in the hydraulic oil temperature THoil is suppressed. Therefore, even if it is determined whether the lockup clutch LC is switched from the disengaged state to the slip engagement based on whether the hydraulic oil temperature THoil of the hydraulic oil ATF reaches the lockup start temperature α, the lockup clutch LC The effect of the present invention can be obtained by enlarging the flex lockup region where the slipping engagement is performed. Thus, the lockup region of the lockup clutch of the present invention includes a lockup on region where the lockup clutch is fully engaged and a flex lockup region where the lockup clutch is slip engaged.

In the above-described embodiment, the travel history of the vehicle 10 includes, in addition to the travel distance L, the accumulated travel time of the vehicle 10, the accumulated lockup control time of the lockup clutch LC, and the lockup control of the lockup clutch LC. at least one of the number of executions of , and the accumulation of the slip amount during the execution transition period of the lockup control of the lockup clutch LC. These requirements can be applied because they are related values related to deterioration of hydraulic oil ATF. In this case, for example, in the area map shown in FIG. 8, the horizontal axis is changed to the travel history considering the travel distance L of the vehicle 10 and the above requirements.

Further, in the above-described embodiment, the deterioration degree RATF of the hydraulic oil ATF was calculated based on the deterioration caused by the heat load caused by the heat generation of the hydraulic oil ATF. The degree of deterioration RATF of the hydraulic oil ATF may be calculated in consideration of deterioration due to mechanical load caused by shearing.

In the above-described embodiment, a planetary gear type stepped transmission composed of a plurality of planetary gear devices was applied as the stepped transmission 22. Not limited. Further, the transmission is not necessarily limited to a stepped type, and may be, for example, a belt type continuously variable transmission.

Further, in the above-described embodiments, a torque converter having a torque amplifying function is used as the fluid transmission device, but it is not necessarily limited to the torque converter, and a fluid coupling that does not have a torque amplifying function may be used.

Also, in the above-described embodiment, the order of the flow chart of FIG. 13 may be changed as appropriate within the range in which the effects of the present invention can be obtained. For example, even if step ST3 in FIG. 13 is moved below step ST4, the effect of the present invention can be obtained.

It should be noted that what has been described above is just one embodiment, and the present invention can be implemented in aspects with various modifications and improvements based on the knowledge of those skilled in the art.

20: Torque converter (fluid transmission)
20p: pump impeller (input-side rotating member)
20t: Turbine wheel (rotating member on the output side)
50: Electronic control device (control device)
LC: Lock-up clutch RATF: Degree of deterioration of hydraulic oil ΔRATF: Rate of increase in degree of deterioration of hydraulic oil
ATF: Hydraulic oil

Claims (1)

A control device for a lockup clutch provided in a fluid transmission device that transmits power via hydraulic oil and capable of connecting and disconnecting between an input-side rotating member and an output-side rotating member of the fluid transmission device,
A control device for a lock-up clutch, wherein the lock-up region of the lock-up clutch is expanded as the degree of deterioration of the hydraulic oil increases.

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