Lubrication control device for automatic transmission

Abstract

To secure durability of a friction fastening element for start and internal components that receives impact of temperature of lubrication oil in a lubrication control device for an automatic transmission.SOLUTION: A lubrication control device of an automatic transmission 10 includes: a first lubrication circuit for supplying a lubrication oil to a friction fastening element BR2 for start to be fastened at the time of start of the vehicle; a second lubrication circuit for supplying lubrication oil to lubrication parts CL1-CL3 other than the friction fastening element BR2 for start; and control means for controlling to increase the flow rate in the first lubrication circuit while restricting the flow rate of the second lubrication circuit when the temperature of the friction fastening element BR2 for start is a threshold value Thigh or more. The control means changes the threshold value according to the temperature of the lubrication oil.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a lubrication control device for an automatic transmission, and more particularly belongs to the technical field of lubrication structures for friction engagement elements of an automatic transmission mounted on a vehicle such as an automobile.

Background Art

[0002] An automatic transmission mounted on a vehicle has a plurality of friction engagement elements for switching a power transmission path and a hydraulic control device including a plurality of solenoid valves for controlling supply and discharge of hydraulic oil to these friction engagement elements, and controls the operation of the solenoid valves by a control signal from a control unit to engage / release each friction engagement element and realize a gear shift stage according to the driving state of the vehicle.

[0003] Among the plurality of friction engagement elements constituting the automatic transmission, there is a starting friction engagement element that is engaged at the start of the vehicle. In particular, in an automatic transmission that has abolished a fluid transmission device typified by a torque converter, smooth starting is realized by performing control to gradually engage the starting friction engagement element while slipping it. At this time, the friction plates of the starting friction engagement element generate heat due to sliding friction caused by slipping, which may reduce durability.

[0004] As the friction engagement elements of the automatic transmission, wet friction engagement elements in which lubricating oil is supplied between the friction plates may be used. In particular, for the starting friction engagement element, it is desirable to supply a larger amount of lubricating oil than other friction engagement elements and lubricating parts such as the main shaft other than the starting friction engagement element according to the driving state of the vehicle and appropriately cool it. For example, Patent Document 1 discloses a device that switches the amount of lubricating oil supplied according to the temperature of the starting friction engagement element.

[0005] According to the configuration of Patent Document 1, for example, when an excessive heat load is applied to the starting friction engagement element such as an accelerator hill hold or towing, the flow rate of the lubrication circuit for supplying lubricating oil to the starting friction engagement element is increased to ensure the durability of the starting friction engagement element.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The lubrication control device for an automatic transmission described in Patent Document 1 increases the lubricating oil amount supplied to the starting friction engagement element while restricting the lubricating oil amount supplied to other friction engagement elements other than the starting friction engagement element when the temperature of the starting friction engagement element is equal to or higher than the threshold value. While ensuring the durability of the starting friction engagement element, the lubricating oil is likely to heat up.

[0008] When the lubricating oil becomes high temperature, there is a possibility of causing leakage from the seal part due to a decrease in the viscosity of the lubricating oil and a decrease in the performance of the components arranged in the oil pan. Therefore, a lubrication control device that takes into account suppressing the temperature rise of both the temperature of the starting friction engagement element and the temperature of the lubricating oil is required.

[0009] Therefore, an object of the present invention is to provide a lubrication control device for an automatic transmission that can achieve both suppression of the temperature rise of the temperature of the starting friction engagement element and the temperature of the lubricating oil, and ensure the durability of internal components that are affected by the temperature of the lubricating oil as well as the starting friction engagement element.

Means for Solving the Problems

[0010] In order to solve the above problems, the present invention provides a lubrication control device for controlling the lubricating oil of an automatic transmission, comprising: a first lubrication circuit for supplying the lubricating oil to a starting friction engagement element engaged at the start of the vehicle; a second lubrication circuit for supplying the lubricating oil to lubrication parts other than the starting friction engagement element; and control means for increasing the flow rate of the lubricating oil supplied by the first lubrication circuit while restricting the flow rate of the lubricating oil supplied by the second lubrication circuit when the temperature of the starting friction engagement element is equal to or higher than a threshold value, wherein the control means changes the threshold value according to the temperature of the lubricating oil.

[0011] In the present invention configured as described above, by changing the threshold value, it is possible to change the cooling priority weighting between the starting friction engagement element and the lubricating oil according to the lubricating oil temperature. Thereby, it is possible to achieve both suppression of the temperature rise of the starting friction engagement element and the temperature rise of the lubricating oil. Therefore, the durability of the starting friction engagement element and the internal parts affected by the lubricating oil temperature is ensured.

[0012] In the present invention, preferably, the control means controls such that the threshold value increases as the temperature of the lubricating oil increases.

[0013] In the present invention configured as described above, as the lubricating oil temperature rises, by reducing the temperature range of the starting friction engagement element where the flow rate of the lubricating oil supplied to the starting friction engagement element increases, it is possible to make it difficult to raise the temperature of the lubricating oil while considering the cooling of the starting friction engagement element. Thereby, it is possible to achieve both suppression of the temperature rise of the starting friction engagement element and the lubricating oil, and the durability of the starting friction engagement element and the internal parts affected by the lubricating oil temperature is ensured.

[0014] In the present invention, preferably, when the threshold value when the temperature of the lubricating oil is less than a predetermined temperature is set as a first threshold value, the control means controls to set the threshold value when the temperature of the lubricating oil is equal to or higher than the predetermined temperature to a second threshold value higher than the first threshold value.

[0015] In the present invention configured as described above, when the lubricating oil is at a high temperature, the temperature range of the starting friction engaging element that increases the flow rate of the lubricating oil supplied to the starting friction engaging element is reduced, making it difficult to raise the temperature of the lubricating oil. As a result, it is possible to achieve both suppression of temperature rise of the starting friction engaging element and the lubricating oil, and the durability of the starting friction engaging element and the lubricating oil is ensured. Further, by patternizing it as a two-stage threshold value based on the threshold value of the temperature of the lubricating oil, it is possible to appropriately achieve both suppression of temperature rise without complicating the control related to the threshold value setting.

[0016] In the present invention, preferably, an oil cooler for cooling the lubricating oil is further provided, and the second lubrication circuit supplies the lubricating oil to the lubricating portion via the oil cooler.

[0017] In the present invention configured as described above, in the second lubrication circuit that functions as a temperature rise suppression circuit for the lubricating oil, since an oil cooler is further provided, the temperature rise suppression effect of the lubricating oil can be further enhanced.

[0018] In the present invention, preferably, a first supply means connected to the first lubrication circuit and the second lubrication circuit is further provided, and the original pressure of the lubricating oil supplied by the first supply means is constant.

[0019] In the present invention configured as described above, since the load of the drive source (engine) used to operate the first supply means can be made constant, it does not cause a decrease in fuel consumption performance due to the operating load.

[0020] In the present invention, preferably, a second supply means connected to the first lubrication circuit is further provided, and the control means controls the second supply means to operate according to the temperature of the starting friction engaging element to supply the lubricating oil to the starting friction engaging element.

[0021] Since the friction engagement element for starting performs slip control, the amount of heat generated (heating rate) is remarkable compared to the lubricated portion. Therefore, in the present invention configured as described above, in a state where the first supply means is operating, control is performed so that the second supply means is additionally operated according to the temperature of the friction engagement element for starting. Thereby, a large amount of lubricating oil necessary for the friction engagement element for starting is appropriately supplied, and the friction engagement element for starting is appropriately cooled, so that the durability of the friction engagement element for starting can be ensured.

[0022] In the present invention, preferably, the first lubrication circuit includes a first main lubrication circuit that supplies the lubricating oil to the friction engagement element for starting, and a first lubricating oil increment circuit that branches from the first main lubrication circuit. A first on-off valve is provided in the first lubricating oil increment circuit, and it is configured to increase the flow rate of the first lubrication circuit by changing the first on-off valve from a closed state to an open state.

[0023] In the present invention configured as described above, when the temperature of the friction engagement element for starting is equal to or higher than the threshold value, by changing the first on-off valve from a closed state to an open state and increasing the flow rate of the first lubrication circuit, it becomes easy to supply a large amount of lubricating oil to the friction engagement element for starting where lubricating oil supply is to be prioritized, and the durability of the friction engagement element for starting is ensured.

[0024] In the present invention, preferably, the second lubrication circuit includes a second main lubrication circuit that supplies the lubricating oil to the lubricated portion, and a second lubricating oil increment circuit that branches from the second main lubrication circuit. A second on-off valve is provided in the second lubricating oil increment circuit, and it is configured to limit the flow rate of the second lubrication circuit by changing the second on-off valve from an open state to a closed state.

[0025] In the present invention configured as described above, when the temperature of the starting friction engagement element is equal to or higher than the threshold value, by setting the second on-off valve from the open state to the closed state to restrict the supply of lubricating oil to the lubricating portion, the restricted amount can be redirected to the supply to the starting friction engagement element. Therefore, it becomes easy to supply a large amount of lubricating oil to the starting friction engagement element to which lubricating oil supply is to be prioritized, and the durability of the starting friction engagement element is ensured.

[0026] In the present invention, preferably, a towing mode setting unit is further provided, and the control means controls such that the threshold value is changed according to the temperature of the lubricating oil when the towing mode is set by the towing mode setting unit.

[0027] During towing, the required transmission torque is large, the amount of heat generated by slip control of the starting friction engagement element is significant, and the lubricating oil also easily heats up. Therefore, in the present invention configured as described above, it is possible to achieve both suppression of temperature rise of the starting friction engagement element and the lubricating oil during towing. Thereby, the durability of internal components affected by the temperatures of the starting friction engagement element and the lubricating oil is ensured.

[0028] In the present invention, preferably, the first supply means is a mechanical pump that is mechanically driven by a drive source.

[0029] In the present invention configured as described above, since an existing mechanical pump can be diverted, lubrication control can be suitably executed without complicating the configuration.

[0030] In the present invention, preferably, the second supply means is an electric pump provided independently of the drive source.

[0031] In the present invention configured as described above, since the electric pump is independent of the operation of the drive source, lubricating oil can be additionally supplied at an arbitrary timing and an arbitrary supply amount.

[0032] In the present invention, preferably, the starting friction engagement element is a brake that forms the first gear of the automatic transmission, starts the vehicle by slip control, and is then engaged.

[0033] In the present invention configured as described above, by slip control of the starting friction engagement element that forms the first gear of the automatic transmission, the vehicle can be smoothly started without using a starting mechanism such as a torque converter. Since the brake does not rotate the drum equipped with the piston chamber, centrifugal force does not act, and the controllability is better than that of a clutch in which the drum equipped with the piston chamber rotates, and starting control can be performed more precisely.

Advantages of the Invention

[0034] According to the present invention, it is possible to achieve both suppression of the temperature rise of the starting friction engagement element and the lubricating oil, and ensure the durability of the automatic transmission including not only the starting friction engagement element but also internal components affected by the temperature of the lubricating oil.

Brief Description of the Drawings

[0035]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0036] Hereinafter, with reference to the accompanying drawings, details of a lubrication control device for an automatic transmission according to an embodiment of the present invention will be described.

[0037] FIG. 1 is a schematic diagram showing the configuration of an automatic transmission 10 according to the present embodiment. The automatic transmission 10 is connected to a drive source such as an engine without intervening a fluid transmission device such as a torque converter. As shown in FIG. 1, the automatic transmission 10 has a transmission case 11, an input shaft 12 connected to the drive source and disposed on the drive source side (left side in the figure), and an output shaft 13 disposed on the counter drive source side (right side in the figure). The automatic transmission 10 is a longitudinally mounted type for a front engine-rear drive vehicle in which the input shaft 12 and the output shaft 13 are arranged on the same axis.

[0038] On the axial centers of the input shaft 12 and the output shaft 13, from the drive source side, first, second, third, and fourth planetary gear sets (hereinafter simply referred to as "first, second, third, and fourth gear sets") PG1, PG2, PG3, and PG4 are disposed.

[0039] In the transmission case 11, a first clutch CL1 is disposed on the drive source side of the first gear set PG1, a second clutch CL2 is disposed on the drive source side of the first clutch CL1, and a third clutch CL3 is disposed on the drive source side of the second clutch CL2. Further, a first brake BR1 is disposed on the drive source side of the third clutch CL3, and a second brake BR2 is disposed on the drive source side of the third gear set PG3 and on the opposite drive source side of the second gear set PG2.

[0040] The first, second, third, and fourth gear sets PG1, PG2, PG3, and PG4 are all of the single pinion type in which the pinions instructed by the carrier directly mesh with the sun gear and the ring gear. The first, second, third, and fourth gear sets PG1, PG2, PG3, and PG4 each have, as rotating elements, sun gears S1, S2, S3, and S4, ring gears R1, R2, R3, and R4, and carriers C1, C2, C3, and C4.

[0041] The first gear set PG1 is of the double sun gear type in which the sun gear S1 is axially divided into two parts. The sun gear S1 has a first sun gear S1a disposed on the drive source side in the axial direction and a second sun gear S1b disposed on the opposite drive source side. The first and second sun gears S1a and S1b have the same number of teeth and mesh with the same pinion supported by the carrier C1. Thereby, the first and second sun gears S1a and S1b always rotate at the same speed.

[0042] In the automatic transmission 10, the sun gear S1 of the first gear set PG1 and the sun gear S4 of the fourth gear set PG4 are always connected. Specifically, the second sun gear S1b and the sun gear S4 of the fourth gear set PG4 are always connected. Further, in the automatic transmission 10, the ring gear R1 of the first gear set PG1 and the sun gear S2 of the second gear set PG2 are always connected, the carrier C2 of the second gear set PG2 and the carrier C4 of the fourth gear set PG4 are always connected, and the carrier C3 of the third gear set PG3 and the ring gear R4 of the fourth gear set PG4 are always connected.

[0043] The input shaft 12 is constantly connected to the carrier C1 of the first gear set PG1 through between the first sun gear S1a and the second sun gear S1b. The output shaft 13 is constantly connected to the carrier C4 of the fourth gear set PG4. Specifically, the input shaft 12 is coupled to the first carrier C1 via a power transmission member 14 passing through between a pair of the first sun gears S1a, S1b, and the fourth carrier C4 is coupled to the second carrier C2 via a power transmission member 15.

[0044] The first clutch CL1 is disposed between the input shaft 12, the carrier C1 of the first gear set PG1, and the sun gear S3 of the third gear set PG3 to connect and disconnect them. The second clutch CL2 is disposed between the ring gear R1 of the first gear set PG1, the sun gear S2 of the second gear set PG2, and the sun gear S3 of the third gear set PG3 to connect and disconnect them. The third clutch CL3 is disposed between the ring gear R2 of the second gear set PG2 and the sun gear S3 of the third gear set PG3 to connect and disconnect them.

[0045] The first brake BR1 is disposed between the transmission case 11 and the sun gear S1 of the first gear set PG1 to connect and disconnect them. Specifically, the first brake BR1 is disposed between the transmission case 11 and the first sun gear S1a. The second brake BR2 is disposed between the transmission case 11 and the ring gear R3 of the third gear set PG3 to connect and disconnect them.

[0046] Figure 2 is the engagement table of the automatic transmission 10. The automatic transmission 10 constitutes any one of the 1st to 8th speeds in the D range and the reverse speed in the R range by the combination of the engagement states of the first clutch CL1, the second clutch CL2, the third clutch CL3, the first brake BR1, and the second brake BR2. In Figure 2, "〇" represents the engaged state. As an example, if the first clutch CL1, the first brake BR1, and the second brake BR2 are in the engaged state, it means that the automatic transmission 10 is in the first-speed state in the D range. In the present embodiment, the automatic transmission 10 selects and engages three of the first clutch CL1, the second clutch CL2, the third clutch CL3, the first brake BR1, and the second brake BR2 to form any one of the 1st to 8th speeds in the D range and the reverse speed in the R range. Further, the automatic transmission 10 has a hydraulic control device 2 that realizes the gear shift by engaging and releasing the first clutch CL1, the second clutch CL2, the third clutch CL3, the first brake BR1, and the second brake BR2 based on the engagement table of Figure 2. The configuration example of the hydraulic control device 2 will be described later.

[0047] Here, the first clutch CL1, the second clutch CL2, the third clutch CL3, the first brake BR1, and the second brake BR2 are elements having an engaged state. Therefore, in the present embodiment, the first clutch CL1, the second clutch CL2, the third clutch CL3, the first brake BR1, and the second brake BR2 may be collectively referred to as friction engagement elements. Since the second brake BR2 is one of the friction engagement elements that form the first speed of the automatic transmission 10, it may be referred to as a starting friction engagement element. Further, among the friction engagement elements, the first clutch CL1, the second clutch CL2, the third clutch CL3, and the first brake BR1 excluding the second brake BR2, which is a starting friction engagement element, may be collectively referred to as a lubricating portion.

[0048] Note that the second brake BR2 starts the vehicle by performing slip control when the vehicle starts, and then is engaged. By including the second brake BR2 having such characteristics, the automatic transmission 10 can gradually transmit torque by the slip control of the second brake BR2 and smoothly start the vehicle without using a starting mechanism such as a torque converter.

[0049] Furthermore, since the brake has a structure in which the drum provided with the piston chamber used for engagement and release does not rotate, the centrifugal force by the hydraulic oil does not act. Therefore, the controllability is better than when a clutch in which the drum rotates serves as the starting friction engagement element, and more precise starting control can be performed.

[0050] Next, a configuration example of the automatic transmission 10 will be described with reference to FIG. 3. FIG. 3 is a block diagram showing the entire system of the automatic transmission 10 in the present embodiment.

[0051] As shown in FIG. 3, the automatic transmission 10 includes the first clutch CL1, the second clutch CL2, the third clutch CL3, the first brake BR1, and the second clutch BR2, which are each friction engagement element. Further, the automatic transmission 10 includes a hydraulic control device 2, a vehicle speed sensor 201, an accelerator opening sensor 202, an input rotation speed sensor 203, an output rotation speed sensor 204, an oil temperature sensor 205, an input torque sensor 206, an oil pressure sensor 207, and a towing mode setting unit 209.

[0052] The vehicle speed sensor 201 detects the traveling speed of the vehicle. The accelerator opening sensor 202 detects the accelerator opening indicating the depression amount of the accelerator pedal. The input rotation speed sensor 203 detects the engine speed as the input rotation speed input to the automatic transmission 10. The output rotation speed sensor 204 detects the output rotation speed output from the automatic transmission 10. The oil temperature sensor 205 detects the temperature (ATF temperature) of the lubricating oil (Automatic Transmission Fluid, ATF) stored in the oil storage portion at the bottom of the transmission case 11 of the automatic transmission 10. The input torque sensor 206 detects the engine output torque as the input torque input to the automatic transmission 10. The hydraulic pressure sensor 207 detects the hydraulic pressure of the hydraulic oil supplied to each friction engagement element.

[0053] The towing mode setting unit 209 detects that the occupant has set the towing mode. When the towing mode is set, the towing mode setting unit 209 outputs that the towing mode is set as an input signal input to the control unit 200. Note that when the towing mode is set, the towing mode setting unit 209 may use whether or not the towing mode is set as an input signal. During towing, the required transmission torque capacity is larger than during normal driving, and accordingly, the amount of heat generated by the slip control of the second brake BR2 also increases. Therefore, the towing mode setting unit 209 executes lubrication control as the towing mode described later to appropriately cool the second brake BR2 and ensure durability.

[0054] The towing mode setting unit 209 is provided, for example, in the vicinity of a shift lever (not shown) provided in the vehicle to change the range of the automatic transmission 10, and may be an operation unit having an arbitrary shape such as a dial shape, a push button shape, a knob, a knob, etc. Alternatively, the towing mode setting unit 209 may be set to the towing mode when an occupant operates a predetermined switch provided in the vehicle interior, or may be set to the towing mode by detecting a connection to a device (for example, a hitch member, a trailer hitch, etc.) provided at the rear of the vehicle for towing another vehicle or the like.

[0055] The hydraulic control device 2 includes a hydraulic control circuit 20 and a control unit 200. The hydraulic control circuit 20 includes a mechanical pump (Mechanical Oil Pump, MOP) 21, an electric pump (Electrical Oil Pump, EOP) 22, a first on-off valve 51 for lubricating oil supply control, a second on-off valve 52 for lubricating oil supply control, a plurality of linear valves 60 for shifting, and a line pressure control linear valve 61.

[0056] The mechanical pump 21 and the electric pump 22 are hydraulic supply sources and are hydraulic supply means for supplying hydraulic pressure to each of the friction engagement elements. The mechanical pump 21 is mechanically driven by an engine (not shown) acting as a drive source. The electric pump 22 is mainly driven electrically during engine stop such as at idle stop. The electric pump 22 is configured to be independently drivable from the drive source and the mechanical pump 21. Therefore, the electric pump 22 can additionally supply lubricating oil at an arbitrary timing and an arbitrary supply amount corresponding to the cooling performance required by the second brake BR2. In the present embodiment, the mechanical pump 21 may be referred to as the first supply means, and the electric pump 22 may be referred to as the second supply means.

[0057] The hydraulic control circuit 20 adjusts the hydraulic pressure discharged from the mechanical pump 21 and the electric pump 22, and generates the operating pressure for forming gear shift stages, such as the engagement pressure or release pressure, which is supplied to each of the first clutch CL1, the second clutch CL2, the third clutch CL3, the first brake BR1, and the second brake BR2, which are friction engagement elements for gear shift control.

[0058] Furthermore, the hydraulic control circuit 20 supplies lubricating oil to each of the first clutch CL1, the second clutch CL2, the third clutch CL3, the first brake BR1, and the second brake BR2, which are the starting friction engagement elements and lubrication parts in the automatic transmission 10. Specifically, the oil passage for supplying the lubricating oil discharged from the mechanical pump 21 is connected to the first lubrication circuit and the second lubrication circuit described later, and the oil passage for supplying the lubricating oil discharged from the electric pump 22 is connected to the second lubrication circuit described later, and supplies lubricating oil to each friction engagement element.

[0059] The first on-off valve 51 controls the control pressure to the lubricating oil increment valve 34 for the second brake, which will be described later, by being turned on or off. When the first on-off valve 51 is on, the control pressure is supplied to the lubricating oil increment valve 34 for the second brake. On the other hand, when the first on-off valve 51 is off, the control pressure is not supplied to the lubricating oil increment valve 34 for the second brake.

[0060] The second on-off valve 52 controls the control pressure to the lubricating oil increment valves 35 for the first to third clutches, which will be described later, by being turned on or off. When the second on-off valve 52 is on, the control pressure is supplied to the lubricating oil increment valves 35 for the first to third clutches. On the other hand, when the second on-off valve 52 is off, the control pressure is not supplied to the lubricating oil increment valves 35 for the first to third clutches.

[0061] The plurality of linear valves 60 for shifting are valves for generating fastening hydraulic pressure. The plurality of linear valves 60 for shifting are supplied with a control pressure for shifting from the hydraulic control circuit 20. Each of the plurality of linear valves 60 for shifting generates a fastening pressure and supplies the fastening pressure to the fastening chambers of the respective friction fastening elements according to the shift stage. Thereafter, the friction fastening elements to which the fastening pressure is supplied are fastened.

[0062] The linear valve 61 for line pressure control is a valve for generating line pressure. The linear valve 61 for line pressure control is guided by the control pressure generated by a reducing valve 41 described later, and generates a line pressure adjustment pressure for adjusting the set pressure of the line pressure to a predetermined pressure according to the operating state of the vehicle.

[0063] The control unit 200 is control means for controlling the hydraulic control circuit 20. The control unit 200 inputs various external signals and controls the vehicle.

[0064] The control unit 200 inputs detection signals detected by a vehicle speed sensor 201, an accelerator opening sensor 202, an input rotation speed sensor 203, an output rotation speed sensor 204, an oil temperature sensor 205, an input torque sensor 206, and a hydraulic pressure sensor 207.

[0065] The control unit 200 includes a shift control means 210, a lubricating oil supply control means 220, and a temperature calculation means 230 for each friction fastening element. The control unit 200 includes, for example, a processor such as a CPU (Central Processing Unit). There may be one or a plurality of processors. The processor functions as the shift control means 210, the lubricating oil supply control means 220, and the temperature calculation means 230 for each friction fastening element by executing a predetermined program read from a storage device (storage unit) not shown. Note that each of the shift control means 210, the lubricating oil supply control means 220, and the temperature calculation means 230 for each friction fastening element may be configured by hardware.

[0066] The shift control means 210 inputs the detection values from various sensors including the vehicle speed sensor 201, the accelerator opening sensor 202, the engine speed sensor 203, and the output speed sensor 204. The shift control means 210 controls the shift by outputting a control signal to the hydraulic control circuit 20 based on the detection values from the various sensors.

[0067] The lubricating oil supply control means 220 determines the supply destination and supply amount of the lubricating oil for the automatic transmission 10 based on a plurality of lubricating oil supply patterns shown in FIG. 6, and performs lubricating oil supply control. The lubricating oil supply patterns are stored in advance in a storage unit (not shown) of the control unit 200. Note that the lubricating oil supply patterns may be input from an external device (not shown). The lubricating oil supply control means 220 performs lubricating oil supply control by outputting a control signal to the hydraulic control circuit 20 based on the input signals from the input speed sensor 203, the output speed sensor 204, the oil temperature sensor 205, the input torque sensor 206, the hydraulic pressure sensor 207, and the towing mode setting unit 209.

[0068] The lubricating oil supply control means 220 implements lubricating oil supply control by switching the lubricating oil supply patterns supplied to the friction engagement elements (the first clutch CL1, the second clutch CL2, the third clutch CL3, the first brake BR1, and the second brake BR2) according to the state of the vehicle. By implementing the lubricating oil supply control, the lubricating oil supply control means 220 suppresses the heat load of each friction engagement element, reduces the stirring resistance and drag resistance of the lubricating oil in each friction engagement element, and the discharge loss of the oil pump to improve fuel efficiency, and suppresses the performance degradation of the automatic transmission 10 caused by the temperature rise of the lubricating oil.

[0069] Each friction engagement element temperature calculation means 230 calculates the temperature of each friction engagement element (first clutch CL1, second clutch CL2, third clutch CL3, first brake BR1, second brake BR2). Each friction engagement element temperature calculation means 230 calculates the temperature of each friction engagement element every predetermined cycle, and calculates the temperature drop rate of the friction engagement element using a map showing the cooling characteristics of the temperature of each friction engagement element in the automatic transmission shown in FIG. 7. Note that a plurality of each friction engagement element temperature calculation means 230 may be provided corresponding to each friction engagement element, or only one may be provided. When a plurality of each friction engagement element temperature calculation means 230 are provided, among each friction engagement element temperature calculation means 230, each friction engagement element temperature calculation means 230 that calculates the temperature of the second brake BR2 may be referred to as a starting friction engagement element temperature calculation means.

[0070] Next, the hydraulic control circuit 20 will be described with reference to FIGS. 4 and 5. FIGS. 4 and 5 are circuit diagrams mainly showing the hydraulic control circuit 20 related to lubricating oil supply. FIGS. 4 and 5 show the hydraulic control circuit 20 which is a single hydraulic circuit, and the symbols A, B, C, D in the figure respectively correspond.

[0071] The hydraulic control circuit 20 includes a plurality of spool valves that operate by hydraulic pressure and spring force to switch oil passages and adjust hydraulic pressure, a plurality of on-off solenoid valves (hereinafter referred to as "on-off valves") that operate by an electric signal to connect or block the oil passage, and a plurality of linear solenoid valves (hereinafter referred to as "linear valves") that also operate by an electric signal to supply and discharge and adjust the operating pressure. The hydraulic control circuit 20 is configured such that a hydraulic pressure supply source, these valves, and the friction engagement elements are connected via an oil passage to perform lubricating oil supply control such as controlling shift control and supply of lubricating oil.

[0072] As shown in FIG. 4, the hydraulic control circuit 20 includes a mechanical pump 21, an electric pump 22, a regulator valve 31, a pump shift valve 32, a lubrication switching valve 33, a reducing valve 41, and a line pressure control linear valve 61. Further, as shown in FIG. 5, the hydraulic control circuit 20 further includes a second brake lubricating oil increasing valve 34, a first to third clutch lubricating oil increasing valves 35, a lubricating reducing valve 42, a first on-off valve 51, a second on-off valve 52, fixed orifices 81, 82, and 83, increasing orifices 84 and 85, an oil cooler 91, and a lubricating oil relief valve 92.

[0073] Returning to FIG. 4, the description will be continued. The regulator valve 31 adjusts the discharge pressure of the mechanical pump 21 to a predetermined line pressure. The regulator valve 31 includes control ports 311 and 312 and a spool 313. The control port 311 is connected to the line pressure oil passage a, and the control port 312 is connected to the control pressure oil passage e via the line pressure control linear valve 61. The spool 313 is configured such that its position is variable, and the communication destination differs depending on the position of the spool 313. When the control pressure of the line pressure control linear valve 61 and the force by a spring (not shown) are smaller than the force by the line pressure, the spool 313 is located on the left side in the drawing (hereinafter the same), and the line pressure oil passage a communicates with the main lubrication circuit f. In the opposite case, the spool 313 is located on the right side and the line pressure oil passage a communicates with the drain port in addition to the main lubrication circuit f.

[0074] The pump shift valve 32 switches between the line pressure and the discharge pressure of the electric pump 22, and selectively supplies it to the friction engagement element side as the source pressure for the shift control hydraulic pressure. The pump shift valve 32 includes control ports 321 and 322, and a spool 323. The control ports 321 and 322 are located at both ends of the pump shift valve 32. The control port 321 is connected to a line pressure oil passage a that supplies line pressure, and the control port 322 is connected to a discharge oil passage b of the electric pump 22 via a lubrication switching valve 33. The spool 323 is configured to have a variable position, and the communicating path varies depending on the position of the spool 323. When the force due to the line pressure and the force due to a spring (not shown) are greater than the force due to the discharge pressure of the electric pump 22, the spool 323 is located on the right side (lower side of the drawing) in the drawing, and the line pressure oil passage a communicates with the shift source pressure oil passage d. In the reverse case, the spool 323 is located on the left side (upper side of the drawing) in the drawing, and the discharge oil passage b of the electric pump 22 communicates with the shift source pressure oil passage d.

[0075] The lubrication switching valve 33 supplies the discharge oil of the electric pump 22 as lubricating oil. The lubrication switching valve 33 includes control ports 331 and 332, and a spool 333. The control port 331 is connected to a line pressure oil passage a that supplies line pressure, and the control port 332 is connected to a discharge oil passage b of the electric pump 22. The spool 333 is configured to have a variable position, and the communicating path varies depending on the position of the spool 333. When the force due to the line pressure is greater than the force due to the discharge pressure of the electric pump 22 and the force due to the spring, the spool 333 is located on the left side (lower side of the drawing) in the drawing, and the discharge oil passage b of the electric pump 22 communicates with the lubricating oil additional supply oil passage c. In the reverse case, the spool 333 is located on the right side (upper side of the drawing) in the drawing, and the discharge oil passage b of the electric pump 22 communicates with the pump shift valve 32 via the lubrication switching valve 33.

[0076] The reducing valve 41 is connected to the line pressure oil passage a, generates a control pressure by reducing the line pressure to a predetermined pressure, and guides the generated control pressure to the line pressure control linear valve 61 and supplies it to the regulator valve 31. The line pressure control linear valve 61 generates a line pressure adjustment pressure for adjusting the set pressure of the line pressure to a predetermined pressure according to the driving state of the vehicle.

[0077] The control pressure generated by the reducing valve 41 is supplied to the first on-off valve 51 and the second on-off valve 52 through the control pressure oil passage e by the first and second branch control pressure oil passages e1 and e2 branched from the control pressure oil passage e shown in FIG. 5, respectively.

[0078] Although not shown in FIG. 4, the hydraulic control circuit 20 supplies a control source pressure for shifting to a plurality of shift linear valves 60 that generate fastening pressures for the first clutch CL1, the second clutch CL2, the second clutch CL3, the first brake BR1, and the second brake BR2 through a plurality of shift source pressure branch oil passages from the shift source pressure oil passage d. Then, the fastening pressures generated by the respective linear valves 60 are supplied to the fastening chambers of the respective friction fastening elements according to the shift stage, and the corresponding friction fastening elements are fastened.

[0079] Referring to FIG. 5, the description of the hydraulic control circuit 20 will be continued. The first on-off valve 51 takes two states of on or off, and selects the supply destination of the control pressure according to each state. When the first on-off valve 51 is on, it supplies the control pressure to the lubricating oil increasing valve 34 for the second brake through the first branch control pressure oil passage e1. On the other hand, when the first on-off valve 51 is off, it does not supply the control pressure to the lubricating oil increasing valve 34 for the second brake.

[0080] The second on-off valve 52 assumes two states, on or off, and selects the supply destination of the control pressure according to each state. When the second on-off valve 52 is on, the control pressure is supplied to the lubricating oil increment valve 35 for the first to third clutches through the second branch control pressure oil passage e2. On the other hand, when the second on-off valve 52 is off, the control pressure is not supplied to the lubricating oil increment valve 35 for the first to third clutches. The lubricating oil increment valve 34 for the second brake and the lubricating oil increment valve 35 for the first to third clutches perform opening and closing operations as the lubricating oil supply pattern changes, and switch the amount of lubricating oil supplied by the mechanical pump 21, but the original pressure of the lubricating oil supplied by the mechanical pump 21 is constant.

[0081] Thereby, the load of the drive source (engine) used to operate the mechanical pump 21 can be made constant, so that it is possible to suppress the occurrence of a decrease in fuel consumption performance due to the operating load. In the present embodiment, the lubricating oil increment valve 34 for the second brake may be described as the first on-off valve, and the lubricating oil increment valve 35 for the first to third clutches may be described as the second on-off valve.

[0082] The lubricating reducing valve 42 adjusts the lubricating oil pressure in the main lubrication circuit f. For fail-safe, the line pressure oil passage a is connected to the main lubricating oil passage f connected to the downstream side of the lubricating reducing valve 42 via the orifice 80. The orifice 80 is formed with a small diameter of, for example, φ0.8 mm, and connects the line pressure oil passage a to the main lubrication circuit f when a pressure difference occurs due to a sudden decrease in the lubricating oil pressure in the main lubrication circuit f.

[0083] The lubricating oil flowing through the main lubrication circuit f is branched into a first lubricating branch circuit f1, a second lubricating branch circuit f2, and a third lubricating branch circuit f3 after passing through the oil cooler 91. Thereafter, the lubricating oil is supplied to the first clutch CL1, the second clutch CL2, the third clutch CL3, the first brake BR1, the second brake BR2, and the main shaft in the transmission via the fixed orifices 81, 82, and 83, respectively.

[0084] The main lubrication circuit f is provided with a bypass oil passage f' that bypasses the oil cooler 91, and the bypass oil passage f' is provided with a lubricating oil relief valve 92 for protecting the oil cooler 91.

[0085] The main lubrication circuit f branches off from a branch point i located upstream of the oil cooler 91, and the fourth lubrication branch oil passage f4 is connected to the lubricating oil increment valve 34 for the second brake. The main lubrication oil passage f also branches off a fifth lubrication branch oil passage f5 from a branch point ii located downstream of the oil cooler 91, and is connected to the lubricating oil increment valves 35 for the first to third clutches. The first on-off valve 51, the second on-off valve 52, the lubricating oil increment valve 34, and the lubricating oil increment valve 35 operate to increase the lubricating oil as shown below.

[0086] When the first on-off valve 51 is on, the spool 341 of the lubricating oil increment valve 34 for the second brake is located on the right side (upper side of the paper) in the drawing due to the control pressure supplied from the first branch control pressure oil passage e1, and the fourth lubrication branch oil passage f4 communicates with the lubricating oil increment oil passage g for the second brake. As a result, additional lubricating oil is supplied to the second brake BR2 via the lubricating oil increment valve 34 for the second brake and the increment orifice 84.

[0087] Also, the lubricating oil increment oil passage g for the second brake is configured to be able to supply lubricating oil to the second brake BR2 without passing through the oil cooler 91 with high pipeline resistance. Therefore, the lubricating oil increment oil passage g for the second brake can effectively increase the supply amount of lubricating oil to the second brake BR2 compared to the case of passing through the oil cooler 91. The presence of the lubricating oil increment oil passage g for the second brake enables the second brake BR2 to be cooled more effectively and ensures the durability of the second brake BR2.

[0088] In this embodiment, a circuit portion including a first lubricating branch oil passage f1 that supplies lubricating oil to the second brake BR2 via the oil cooler 91 and a lubricating oil increasing circuit g for the second brake that supplies lubricating oil to the second brake BR2 without passing through the oil cooler 91 may be described as the first lubricating circuit. Further, the lubricating oil increasing oil passage g for the second brake may be called the first lubricating oil increasing circuit, and the first lubricating branch oil passage f1 may be called the first main lubricating circuit.

[0089] As described above, the first lubricating circuit includes a first lubricating branch oil passage f1 that supplies lubricating oil to the second brake BR2 and a lubricating oil increasing oil passage g for the second brake that branches from the first lubricating branch circuit f1. That is, the first lubricating circuit supplies lubricating oil to the second brake BR2, which is a friction engaging element for starting that is engaged when the vehicle starts. A lubricating oil increasing valve 34 for the second brake is provided in the lubricating oil increasing oil passage g for the second brake, and by changing the lubricating oil increasing valve 34 for the second brake from the closed state to the open state, the flow rate of the lubricating oil in the first lubricating circuit is increased. In other words, by changing the lubricating oil increasing valve 34 for the second brake from the closed state to the open state, the flow rate of the lubricating oil supplied by the first lubricating branch oil passage f1 and the lubricating oil increasing oil passage g for the second brake is increased. With such a configuration of the first lubricating circuit, it becomes easy to supply a large amount of lubricating oil when it is desired to prioritize the supply of lubricating oil to the second brake BR2, and the durability of the second brake BR2 can be ensured.

[0090] When the second on-off valve 52 is on, the spool 351 of the lubricating oil increasing valve 35 for the first to third clutches is positioned on the right side (upper side of the paper) in the drawing by the control pressure supplied from the second branch control pressure oil passage e2, and the fifth lubricating branch oil passage f5 is communicated with the lubricating oil increasing oil passage h for the first to third clutches. As a result, additional lubricating oil is supplied to the first clutch CL1 to the third clutch CL3 via the lubricating oil increasing valve 35 for the first to third clutches and the increasing orifice 85.

[0091] In this embodiment, a circuit portion including a second lubricating branch oil passage f2 through which lubricating oil is supplied to the first to third clutches CL1, CL2, and CL3 via an oil cooler 91 and a lubricating oil increasing oil passage h for the first clutch CL1, the second clutch CL2, and the third clutch CL3 may be referred to as a second lubricating circuit. Further, the lubricating oil increasing oil passage h for the first to third clutches may be referred to as a second lubricating oil increasing circuit, and the second lubricating branch oil passage f2 may be referred to as a second main lubricating circuit.

[0092] As described above, the second lubricating circuit includes an oil cooler 91 that cools lubricating oil, and the second lubricating branch oil passage f2 and the lubricating oil increasing oil passage h for the first to third clutches that constitute the second lubricating circuit are configured to supply lubricating oil to the first clutch CL1 to the third clutch CL3, which are lubricating portions, via the oil cooler 91. That is, the second lubricating circuit supplies lubricating oil to the first clutch CL1 to the third clutch CL3, which are lubricating portions other than the second brake BR2, which is a friction engagement element for starting. The second lubricating circuit functions as a lubricating oil temperature rise suppression circuit, and by further including the oil cooler 91, the lubricating oil temperature rise suppression effect can be further enhanced.

[0093] Further, the second lubricating circuit includes a second lubricating branch oil passage f2 that supplies lubricating oil to the first clutch CL1 to the third clutch CL3, which are lubricating portions, and a lubricating oil increasing oil passage h for the first to third clutches that branches from the second lubricating branch circuit f2. The lubricating oil increasing oil passage h for the first to third clutches is provided with a lubricating oil increasing valve 35 for the first to third clutches, and the lubricating oil increasing valve 35 for the first to third clutches is configured to limit the flow rate of the second lubricating circuit by changing from an open state to a closed state. As a result, the lubricating oil whose supply is restricted by the lubricating oil increasing valve 35 for the first to third clutches is supplied to the second brake BR2, so that it becomes easy to supply a large amount of lubricating oil to the second brake BR2 to which lubricating oil supply is to be prioritized, and the durability of the second brake BR2, which is a friction engagement element for starting, can be ensured.

[0094] Furthermore, the hydraulic control circuit 20 is provided with a lubrication switching valve 33 of the electric pump 22 for supplying the discharged oil of the electric pump 22 as lubricating oil to the second brake BR2. The lubrication switching valve 33 connected to the electric pump 22 is supplied with line pressure from the line pressure oil passage a as a control pressure. When the spool 333 is positioned on the left side by this control pressure, the discharge oil passage b of the electric pump 22 communicates with the lubricating oil additional supply passage c, and it is in a state of being connected to the first lubrication circuit. When the electric pump 22 operates in this state, its discharged oil is supplied as lubricating oil to the second brake BR2 through the lubricating oil additional supply passage c.

[0095] Next, with reference to FIG. 6, the lubricating oil supply pattern referred to by the lubricating oil supply control means 220 will be described. FIG. 6 is a table showing the lubricating oil supply pattern of the automatic transmission. As shown in FIG. 6, in the table showing the lubricating oil supply pattern, a cooling requirement level, the communication state of the lubricating oil passages communicating with each friction engagement element, the supply amount of lubricating oil to each friction engagement element, and an assumed scene are set.

[0096] The lubricating oil supply pattern is defined differently according to the cooling requirement level for the second brake BR2 and the cooling requirement levels for the first to third clutches CL1, CL2, and CL3 (specifically, low cooling requirement level L, high cooling requirement level H, and highest cooling requirement level HH). The lubricating oil supply control means 220 refers to the table in which the lubricating oil supply pattern is set according to the cooling requirement levels of the second brake BR2 and the first clutch CL1 to the third clutch CL3, determines the lubricating oil pattern, and switches it.

[0097] The cooling requirement level is determined by determining whether the parameter regarding the temperature of each friction engagement element is equal to or higher than the threshold value for each control cycle. The parameters used to determine the cooling requirement level and the threshold values provided for each parameter will be described.

[0098] As parameters for determining the cooling requirement level, parameters that can determine (estimate) that there is a temperature rise (heat generation) in each friction fastening element are used. Specifically, the input torque detected by the input torque sensor 206, the input rotation speed detected by the input rotation speed sensor 203, and the temperatures of the second brake BR2 and the first clutch CL1 to the third clutch CL3 calculated by each friction fastening element temperature calculating means 230 are used. That is, the cooling requirement level is determined by the input torque, the input rotation speed, the temperature of the second brake BR2, and the temperatures of the first clutch CL1 to the third clutch CL3.

[0099] Since the input torque is in a proportional relationship with the temperature of each friction fastening element, by using the input torque, the temperature rise of each friction fastening element can be estimated. As the input rotation speed increases, the differential rotation ΔN increases. Since this differential rotation ΔN is in a proportional relationship with the temperature of each friction fastening element, similar to the input torque, by using the input rotation speed, the temperature rise of each friction fastening element can be estimated.

[0100] The communication state of the lubricating oil passage communicating with each friction fastening element is the supply destination of the lubricating oil supplied to each friction fastening element. The communication state of the lubricating oil passage communicating with each friction fastening element and the supply amount of the lubricating oil to each friction fastening element are determined by the temperature of each friction fastening element. The temperature of each friction fastening element is calculated by each friction fastening element temperature calculating means 230. The temperature of each friction fastening element is calculated based on the input rotation speed, the output rotation speed, the input torque, the oil pressure in the oil passage communicating with each friction fastening element, and the cooling temperature due to heat dissipation to the ambient air and lubricating oil of each friction fastening element described later. Each friction fastening element temperature calculating means 230 calculates the temperature for each of the first clutch CL1, the second clutch CL2, the third clutch CL3, and the second brake BR2, which are friction fastening elements, based on the input rotation speed, the output rotation speed, the input torque, the oil pressure in the oil passage communicating with each friction fastening element, and the cooling temperature due to heat dissipation to the ambient air and lubricating oil of each friction fastening element.

[0101] The temperature T1 of each friction engagement element is obtained from the following formula (1) based on T0 calculated in the immediately preceding cycle, the absorbed energy E of each friction engagement element, the heat capacity Q of the friction plate of each friction engagement element, the heat dissipation rate (friction engagement element temperature drop rate) Tc from each friction engagement element to the surrounding atmosphere and lubricating oil, and the cooling temperature (Tc × tc) obtained from the cycle time (time required for one calculation) tc. Note that the friction engagement element temperature calculation means 230 calculates the temperature T1 of each friction engagement element in each cycle for each of the friction engagement elements (first clutch CL1, second clutch CL2, third clutch CL3, and second brake BR2) using the temperature T0 of each friction engagement element calculated in the immediately preceding cycle, the absorbed energy E of each friction engagement element, the heat capacity Q of the friction plate of each friction engagement element, the heat dissipation rate (friction engagement element temperature drop rate) Tc from each friction engagement element to the surrounding atmosphere and lubricating oil, the cooling temperature (Tc × tc) obtained from the cycle time (time required for one calculation) tc, and formula (1). Also, the initial value of the temperature T0 of each friction engagement element calculated in the immediately preceding cycle uses the ATF temperature detected by the oil temperature sensor 205.

Equation

[0102] The absorbed energy E of each friction engagement element is obtained from the following formula (2) based on the differential rotation ΔN between the input side and the output side of each friction engagement element and the transmitted torque Trq of each friction engagement element.

Equation

[0103] The differential rotation ΔN is calculated based on the input rotation speed detected by the input rotation speed sensor 203, the output rotation speed detected by the output rotation speed sensor 204, the gear position, and the speed diagram. The differential rotation ΔN is calculated by the rotation speed difference generated between the drum member and the hub member of the friction engagement element that is in the released state at the current gear position and will be in the engaged state at the next gear position.

[0104] The transmission torque Trq is obtained by the following formula (3). Specifically, the transmission torque Trq is calculated using the friction coefficient μ, the number of friction surfaces n, the clutch effective radius calculated by the major diameter Do and minor diameter Di of the friction surfaces of each friction fastening element, the piston area calculated by the major diameter Dpo and minor diameter Dpi of the piston, the operating oil pressure Pa detected by the hydraulic sensor 207, and the pressure Pr by the piston return spring.

Number

[0105] The temperature drop rate Tc of each friction fastening element in formula (1) is obtained based on the heat generation temperature ΔT of each friction fastening element (the temperature of each friction fastening element - ATF temperature) and the relationship between the temperature drop rate Tc of each friction fastening element with respect to the heat generation temperature ΔT of each friction fastening element. The heat generation temperature ΔT of each friction fastening element (the temperature of each friction fastening element - ATF temperature) is calculated from the temperature T0 of each friction fastening element (the calculated value calculated in the previous cycle) and the ATF temperature.

[0106] Regarding the relationship between the temperature drop rate Tc of each friction fastening element with respect to the heat generation temperature ΔT of each friction fastening element, a map showing an example of the cooling characteristics of the temperature of each friction fastening element shown in FIG. 7 is used. The temperature calculation means 230 of each friction fastening element, for example, when the heat generation temperature of the friction fastening element is ΔT0, refers to the map in FIG. 7 and reads the value of the temperature drop rate Tc1 of the friction fastening element to obtain the temperature drop rate Tc1 of the friction fastening element.

[0107] Here, with reference to FIG. 7, a map showing the relationship between the temperature drop rate Tc of each friction fastening element and the heat generation temperature ΔT of each friction fastening element will be described. FIG. 7 is a map showing an example of the cooling characteristics of the temperature of each friction fastening element in the automatic transmission of the present invention. This map is calculated by an approximate formula derived based on experimental values of the temperature drop rate of a predetermined friction fastening element when a predetermined flow rate of lubricating oil is supplied to a predetermined friction fastening element fastened in a predetermined shift state. Note that maps of the temperature drop rate Tc of each friction fastening element with respect to the heat generation temperature ΔT of each friction fastening element are provided for each friction fastening element fastened in a plurality of shift states.

[0108] Returning to FIG. 6, the description will be continued. The threshold values of the above-described parameters (input torque, input rotational speed, temperature of each friction fastening element) are set values (set) under conditions when the heat generation of each friction fastening element is relatively small and an increase in lubricating oil is required. For example, the threshold value Tq1 of the input torque is set to 320 Nm, the threshold value Nin of the input rotational speed is set to 3000 rpm, the threshold values Tcl1, Tcl2, and Tcl3 of the temperatures of the first to third clutches CL1, CL2, and CL3 are set at 135° C., and the low temperature threshold value Tlow of the temperature of the second brake BR2 is set to 110° C. Note that for the temperature of the second brake BR2, a medium temperature threshold value Tmid that is higher than the low temperature threshold value Tlow and a high temperature threshold value Thigh that is higher than the medium temperature threshold value Tmid are set. For example, the medium temperature threshold value Tmid is set to 130° C., and the initial value of the high temperature threshold value Thigh is set to 270° C.

[0109] As shown in FIG. 6, patterns 1 to 6 are set as a plurality of lubricating oil supply patterns. Here, an example of a plurality of lubricating oil supply patterns, the conditions of parameters for switching each lubricating oil supply pattern, and the scenes (vehicle states) assumed for each lubricating oil supply pattern will be described.

[0110] The plurality of lubricating oil supply patterns are switched according to the cooling requirement level for the second brake BR2, the cooling requirement levels for the first clutch CL1 to the third clutch CL3, the cooling requirement level for the lubricating oil, and the driving mode of the vehicle set by the operation of the occupant or the like. For example, the cooling requirement level is a low cooling requirement level L at which the cooling of each friction engagement element can ensure durability by cooling with the supply amount of the lubricating oil constantly supplied to each friction engagement element, a high cooling requirement level H that is higher than the low cooling requirement level L, and a maximum cooling requirement level HH that is higher than the high cooling requirement level H in the second brake BR2.

[0111] When the lubricating oil supply control means 220 determines from the values of the respective parameters that the cooling requirement level for the second brake BR2 is low L and the cooling requirement levels for the first to third clutches CL1, CL2, and CL3 are low L, it executes the control of pattern 1 as the first lubricating oil supply pattern.

[0112] The conditions of each parameter are that the temperature of the second brake BR2 is less than the low temperature threshold Tlow and all of the parameters (input torque, input rotational speed, temperatures of the first to third clutches CL1, CL2, and CL3) for determining the supply amount of the lubricating oil for the first to third clutches CL1, CL2, and CL3 are less than their respective thresholds Tq1, Nin, Tcl1, Tcl2, and Tcl3.

[0113] In pattern 1, the second brake BR2 is supplied with lubricating oil having a first flow rate (small) through the first lubricating branch oil passage f1. The first to third clutches CL1, CL2, and CL3 are supplied with lubricating oil having a second flow rate (small) through the second lubricating branch oil passage f2.

[0114] Scenarios assumed include situations where the lubricating oil supply amount to each friction engagement element does not need to be increased, such as during light load, fuel-efficient driving, coasting down (deceleration for the transmission), before engine startup (for example, when the rotational speed is less than 500 rpm), etc. Thus, in a state where the heat load of each friction engagement element is not high (cooling requirement level is low L), by suppressing the lubricating oil amount, the stirring resistance, dragging resistance due to the lubricating oil of each friction engagement element, and the discharge loss of the oil pump are suppressed. Note that when the lubricating oil supply control means 220 determines from the values of each parameter that the cooling requirement level for the second brake BR2 is low L and the cooling requirement levels for the first to third clutches CL1, CL2, CL3 are high H, it executes the control of pattern 2 as the second lubricating oil supply pattern.

[0115] The conditions of each parameter are that the temperature of the second brake BR2 is less than the low temperature threshold Tlow, and one or more of the parameters (input torque, input rotational speed, temperatures of the first to third clutches CL1, CL2, CL3) for determining the supply amount of the lubricating oil for the first to third clutches CL1, CL2, CL3 are equal to or greater than a predetermined value.

[0116] In pattern 2, the second brake BR2 is supplied with lubricating oil of the first flow rate (small) by the first lubricating branch oil passage f1. The first to third clutches CL1, CL2, CL3 are supplied with lubricating oil of the third flow rate (large), which is larger than the second flow rate, by the lubricating oil increment oil passage h for the first to third clutches in addition to the second lubricating branch oil passage f2.

[0117] Scenarios assumed include situations where the ATF temperature is relatively low (for example, to the extent that the temperature of the second brake BR2 does not reach the low temperature threshold Tlow), and during medium load (for example, a state where the load is higher than at idle and lower than when driving on an uphill road), acceleration, upshift, and downshift due to torque demand, an increase in the supply amount of lubricating oil to the second brake BR2 is not required, and an increase in the supply amount of lubricating oil to the first to third clutches CL1, CL2, CL3 is required.

[0118] Specifically, as shown in FIG. 2, during acceleration, during upshifting, during downshifting due to torque demand (for example, during downshifting from 6th gear to 3rd gear), etc., since the clutching (changing between the released state and the engaged state) of the first to third clutches CL1, CL2, and CL3 is involved, the cooling demand level for the first to third clutches CL1, CL2, and CL3 becomes high.

[0119] On the other hand, during acceleration and upshifting, since there is no situation where the second brake BR2 is newly changed to the engaged state, the temperature of the second brake BR2 does not rise.

[0120] Also, during downshifting due to torque demand, an operation of clutching the second brake BR2 (changing from the released state to the engaged state) occurs. However, the temperature rise of the second brake BR2 in this case is lower than the temperature rise of the second brake BR2 in the slip state of the second brake BR2, and the cooling demand level for the second brake BR2 is low.

[0121] Thus, in a state where the heat loads of the first to third clutches CL1, CL2, and CL3 are high and the heat load of the second brake BR2 is not high, the supply amount of the lubricating oil to the first to third clutches CL1, CL2, and CL3 is increased to ensure the durability of the first to third clutches CL1, CL2, and CL3, and by suppressing the supply amount of the lubricating oil to the second brake BR2, the stirring resistance, dragging resistance, and discharge loss of the oil pump due to the lubricating oil in the second brake BR2 are suppressed.

[0122] When the lubricating oil supply control means 220 determines from the values of the respective parameters that the cooling demand level for the second brake BR2 is high H and the cooling demand levels for the first to third clutches CL1, CL2, and CL3 are low L, it executes the control of pattern 3 as the third lubricating oil supply pattern.

[0123] The conditions for each parameter are that the temperature of the second brake BR2 is equal to or higher than the low temperature threshold Tlow, and all parameters (input torque, input rotational speed, temperatures of the first to third clutches CL1, CL2, CL3) for determining the supply amount of lubricating oil for the first to third clutches CL1, CL2, CL3 are less than a predetermined value.

[0124] In pattern 3, to the second brake BR2, in addition to the first lubricating oil branch oil passage f1, lubricating oil with a fourth flow rate (large), which is larger than the first flow rate, is supplied by the lubricating oil increment circuit g for the second brake. To the first to third clutches CL1, CL2, CL3, lubricating oil with a second predetermined flow rate (small) is supplied by the second lubricating oil branch oil passage f2.

[0125] As assumed scenes, there are situations where an increase in the supply amount of lubricating oil to the second brake BR2 is required, such as during high load conditions like climbing a slope, and during traffic jams, etc., and an increase in the lubricating oil to the first to third clutches CL1, CL2, CL3 is not required.

[0126] Specifically, in a downshift when shifting to climbing a slope, for the second brake BR2, control is performed in a high load slip state to ensure torque capacity and smooth running. Therefore, the temperature of the second brake BR2 easily becomes equal to or higher than the low temperature threshold Tlow, and the cooling requirement level for the second brake BR2 becomes high.

[0127] Also, during traffic jams, since starting and stopping are repeated, the frequency of the slip state of the second brake BR2 increases, so the cooling requirement level of the second brake BR2 becomes high.

[0128] In this way, when the cooling requirement level of the second brake BR2 is high and the cooling requirement levels of the first to third clutches CL1, CL2, CL3 are low, the supply amount of lubricating oil to the second brake BR2 is increased to ensure the durability of the second brake BR2, and at the same time, the stirring resistance, drag resistance, and oil pump discharge loss in the first to third clutches CL1, CL2, CL3 are suppressed.

[0129] When the lubricating oil supply control means 220 determines from the values of the respective parameters that the cooling requirement level for the second brake BR2 is high H and the cooling requirement levels for the first to third clutches CL1, CL2, and CL3 are high H, it executes the control of pattern 4 as the fourth lubricating oil supply pattern.

[0130] The conditions of each parameter are that the temperature of the second brake BR2 is equal to or higher than the low temperature threshold value Tlow, and one or more of the parameters (input torque, input rotational speed, temperatures of the first to third clutches CL1, CL2, and CL3) for determining the supply amount of the lubricating oil for the first to third clutches CL1, CL2, and CL3 are equal to or higher than a predetermined value.

[0131] In pattern 4, for the second brake BR2, in addition to the first lubricating oil branch oil passage f1, lubricating oil with a fourth flow rate (large), which is larger than the first flow rate, is supplied by the lubricating oil increment oil passage g for the second brake. For the first to third clutches CL1, CL2, and CL3, in addition to the second lubricating oil branch oil passage f2, lubricating oil with a third flow rate (large), which is larger than the second flow rate, is supplied by the lubricating oil increment oil passage h for the first to third clutches.

[0132] As an assumed scene, when the ATF temperature is relatively high (for example, to a certain extent where the temperature of the second brake BR2 may reach the low temperature threshold value Tlow), and in a medium load state (for example, a state where the load is higher than that in the idle state and lower than that during uphill driving), during acceleration, during an upshift, or during a downshift due to torque demand, an increase in the supply amount of lubricating oil to the second brake BR2 is required, and an increase in the supply amount of lubricating oil to the first to third clutches CL1, CL2, and CL3 is also assumed to be required.

[0133] Specifically, in a driving scene similar to pattern 2, when the ATF temperature is relatively high, it is considered that the cooling requirement levels for the second brake BR2 and the first to third clutches CL1, CL2, and CL3 become high.

[0134] Thus, when the cooling requirement levels of the second brake BR2 and the first to third clutches CL1, CL2, and CL3 are high, the durability of the second brake BR2 and the first to third clutches CL1, CL2, and CL3 can be prioritized by increasing the supply amount of lubricating oil to the second brake BR2 and the first to third clutches CL1, CL2, and CL3.

[0135] When the lubricating oil supply control means 220 determines from the values of the respective parameters that the cooling requirement level for the second brake BR2 is the highest HH, it executes the control of pattern 5 as the fifth lubricating oil supply pattern.

[0136] The condition of each parameter is that the temperature of the second brake BR2 is equal to or higher than the high temperature threshold Thigh (for example, 270°C). As will be described later, the high temperature threshold Thigh in the towing mode is a value (for example, 200°C or 270°C) set according to the ATF temperature and is changed.

[0137] In pattern 5, for the second brake BR2, in addition to the first lubricating oil branch oil passage f1 and the lubricating oil increased amount oil passage g for the second brake, lubricating oil of a fifth flow rate (extra large), which is larger than the fourth flow rate (large), is supplied by a lubricating oil additional supply oil passage c connected to the discharge oil passage b of the electric pump 22. For the first to third clutches CL1, CL2, and CL3, lubricating oil of the second flow rate is supplied by the second lubricating oil branch oil passage f2.

[0138] As an assumed scene, it is assumed that during high load such as during accelerator hill hold or towing driving, an excessive heat load is applied to the second brake BR2.

[0139] For example, accelerator hill hold is a case where, on an uphill road, the vehicle maintains a stopped state using the required driving force generated when the driver depresses the accelerator pedal without operating the brake pedal.

[0140] In the case of the accelerator hill hold, since the slip torque due to the vehicle weight on the uphill road and the required driving torque are balanced to maintain the braking state, differential rotation occurs between the drive source and the drive wheels. Due to this differential rotation, the second brake BR2 between the drive source and the drive wheels slips, imposing an excessive thermal load on the second brake BR2, thereby making it easier for the durability of the second brake BR2 to deteriorate.

[0141] In such a situation, by giving top priority to the cooling of the second brake BR2, the durability of the second brake BR2 is ensured.

[0142] On the other hand, when an excessive thermal load is applied, such as during towing, if the control of increasing the lubricating oil amount to the second brake BR2 while restricting the lubricating oil amounts to the first to third clutches CL1, CL2, and CL3 as in pattern 5 continues, the ratio of the lubricating oil passing through the high-temperature second brake increases, so the ATF temperature tends to rise. When the ATF temperature becomes high, it is considered that this may lead to leakage from the seal part due to a decrease in the viscosity of the lubricating oil and a deterioration in the performance of the components arranged in the oil pan.

[0143] Therefore, in the present embodiment, when the driving mode of the vehicle is set to the towing mode by the operation of the towing mode setting unit 209 by the occupant, the high-temperature threshold Thigh is changed according to the ATF temperature.

[0144] Specifically, when the vehicle is in the towing mode and the ATF temperature is less than a predetermined temperature Tatf (for example, 105°C), the control unit 200 sets the high-temperature threshold Thigh to a first threshold Thigh1 (for example, 200°C), and when the ATF temperature is equal to or higher than the predetermined temperature Tatf, the control unit 200 performs control to set the high-temperature threshold Thigh to a second threshold Thigh2 (for example, 270°C), which is a temperature higher than the first threshold Thigh1.

[0145] Thus, in a vehicle state where not only the required cooling level of the second brake BR2 but also the required cooling level of the lubricating oil is high, by achieving a balance between suppressing the temperature rise of the second brake BR2 and suppressing the temperature rise of the lubricating oil through the above control, the durability of the entire automatic transmission can be ensured.

[0146] When the lubricating oil supply control means 220 determines from the values of the respective parameters that the cooling required level for the second brake BR2 is high H and the cooling required level for the lubricating oil is also high H, it executes the control of pattern 6 as the sixth lubricating oil supply pattern.

[0147] The conditions of the respective parameters are that the towing mode is set by the towing mode setting unit 209 and the temperature of the second brake BR2 is equal to or higher than the medium temperature threshold value Tmid (for example, 130°C) and lower than the high temperature threshold value Thigh (for example, 270°C).

[0148] In pattern 6, for the second brake BR2, lubricating oil with a sixth flow rate (large), which is larger than the first flow rate (small), is supplied by the first lubricating branch oil passage f1 and the lubricating oil additional supply oil passage c connected to the discharge oil passage b of the electric pump 22. For the first to third clutches CL1, CL2, and CL3, lubricating oil with a third flow rate (large), which is larger than the second flow rate, is supplied by the second lubricating branch oil passage f2 and the lubricating oil increment oil passage h for the first to third clutches.

[0149] Specifically, in addition to the state where the mechanical pump 21 supplies lubricating oil via the first lubricating branch oil passage f1 as a hydraulic pressure supply source, the electric pump 22 is operated to additionally supply lubricating oil via the lubricating oil additional supply oil passage c.

[0150] As a conceivable scenario, it is assumed that the ATF temperature is relatively high and an excessive thermal load is applied to the second brake BR2 during high load conditions such as during accelerator hill hold or towing driving. Specifically, it is assumed that a situation exists where an increase in the supply amount of lubricating oil for cooling the second brake BR2 is required, and an increase in the supply amount of lubricating oil for suppressing the temperature rise of the ATF is required.

[0151] In this way, in a state where the cooling requirement level of the second brake BR2 and the lubricating oil is high, while giving priority to ensuring the durability of the second brake BR2, the durability of the lubricating oil is also ensured.

[0152] Note that the first to sixth lubricating oil supply patterns in FIG. 6 and the map shown in FIG. 7 may be stored in advance in a storage unit (not shown) of the control unit 200.

[0153] Next, with reference to the flowcharts of FIGS. 8 to 10, an example of the operation of the lubricating oil supply control of the automatic transmission 10 will be specifically described. FIGS. 8 to 10 are diagrams showing an example of the operation of the lubricating oil supply control of the automatic transmission.

[0154] First, various sensors detect various information necessary for lubricating oil supply control, and each friction engagement element temperature calculation means 230 calculates the temperatures of each friction engagement element (the first clutch CL1, the second clutch CL2, the third clutch CL3, and the second brake BR2) using the above-described formulas (1) to (3) (step S1). Specifically, the accelerator opening sensor 202 detects the accelerator opening, the oil temperature sensor 205 detects the oil temperature, the input rotation speed sensor 203 detects the input rotation speed, the output rotation speed sensor 204 detects the output rotation speed, the input torque sensor 206 detects the input torque, and the oil pressure sensor 207 detects the oil pressure. Each friction engagement element temperature calculation means 230 calculates the temperatures of each friction engagement element (the first clutch CL1, the second clutch CL2, the third clutch CL3, and the second brake BR2) using the accelerator opening, the oil temperature, the input rotation speed, the output rotation speed, the input torque, and the oil pressure and the above-described formulas (1) to (3).

[0155] Next, based on the temperature of the second brake BR2 calculated by each friction engagement element temperature calculating means 230 in step S1, the lubricating oil supply control means 220 determines whether the temperature of the second brake (starting friction engagement element) BR2 is equal to or higher than a high temperature threshold Thigh (for example, 270°C) (step S2).

[0156] When the temperature of the second brake BR2 is equal to or higher than the high temperature threshold Thigh (YES in step S2), the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is the lubricating oil supply pattern of pattern 5 (step S4).

[0157] When the temperature of the second brake BR2 is lower than the high temperature threshold Thigh (NO in step S2), the lubricating oil supply control means 220 determines whether the vehicle is running in the towing mode and whether the temperature of the second brake BR2 is equal to or higher than a medium temperature threshold Tmid (for example, 130°C) based on the input signal from the towing mode setting unit 209 and the temperature of the second brake BR2 calculated by each friction engagement element temperature calculating means 230 (step S3). That is, the lubricating oil supply control means 220 determines whether the vehicle is running in the towing mode and the temperature of the starting friction engagement element is equal to or higher than the medium temperature threshold Tmid.

[0158] When the vehicle is running in the towing mode and the temperature of the second brake BR2 is equal to or higher than the medium temperature threshold Tmid (YES in step S3), the lubricating oil supply control means 220 executes the lubricating oil supply pattern determination flow in the towing mode shown in FIG. 10 (step S30). In step S30, the lubricating oil supply control means 220 determines (decides) the lubricating oil supply pattern in the towing mode. On the other hand, when the vehicle is running in the towing mode and the temperature of the second brake BR2 is not equal to or higher than the medium temperature threshold Tmid (NO in step S3), the lubricating oil supply control means 220 executes the lubricating oil supply pattern determination flow shown in FIG. 9 (step S14) to determine the lubricating oil supply pattern.

[0159] Finally, the lubricating oil supply control means 220 determines the supply destination and supply amount of the lubricating oil according to the lubricating oil supply pattern determined (decided) in steps S4, S14, and S30, and supplies the lubricating oil (step S40).

[0160] When the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is Pattern 1, the lubricating oil supply control means 220 refers to the table in which the lubricating oil supply pattern shown in FIG. 6 is set, and controls so that the lubricating oil of the first flow rate (small) is supplied to the second brake BR2 by the first lubricating branch oil passage f1. Further, the lubricating oil supply control means 220 controls so that the lubricating oil of the second flow rate (small) is supplied to the first clutch CL1 to the third clutch CL3 by the second lubricating branch oil passage f2.

[0161] When the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is Pattern 2, the lubricating oil supply control means 220 refers to the table in which the lubricating oil supply pattern shown in FIG. 6 is set, and controls so that the lubricating oil of the first flow rate (small) is supplied to the second brake BR2 by the first lubricating branch oil passage f1. Further, in addition to the second lubricating branch oil passage f2, the lubricating oil supply control means 220 controls so that the lubricating oil of the third flow rate (large), which is larger than the second flow rate, is supplied to the first clutch CL1 to the third clutch CL3 by the lubricating oil increment oil passage h for the first to third clutches.

[0162] When the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is Pattern 3, the lubricating oil supply control means 220 refers to the table in which the lubricating oil supply pattern shown in FIG. 6 is set, and in addition to the first lubricating branch oil passage f1, controls so that the lubricating oil of the fourth flow rate (large), which is larger than the first flow rate, is supplied to the second brake BR2 by the lubricating oil increment circuit g for the second brake. That is, the lubricating oil supply control means 220 controls so that the lubricating oil of the fourth flow rate (large) is supplied to the starting friction engagement element by the first lubricating oil increment circuit in addition to the first main lubricating circuit. Further, the lubricating oil supply control means 220 controls so that the lubricating oil of the second predetermined flow rate (small) is supplied to the first clutch CL1 to the third clutch CL3 by the second lubricating branch oil passage f2.

[0163] When the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 4, the lubricating oil supply control means 220 refers to the table in which the lubricating oil supply pattern shown in FIG. 6 is set, and in addition to the first lubricating branch oil passage f1, the second brake lubricating oil increasing oil passage g causes the second brake BR2 to be supplied with lubricating oil having a fourth flow rate (large), which is larger than the first flow rate. Also, the lubricating oil supply control means 220, in addition to the second lubricating branch oil passage f2, controls the first to third clutch lubricating oil increasing oil passages h so that lubricating oil having a third flow rate (large), which is larger than the second flow rate, is supplied to the first to third clutches CL1, CL2, and CL3.

[0164] When the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 5, the lubricating oil supply control means 220 refers to the table in which the lubricating oil supply pattern shown in FIG. 6 is set, and in addition to the first lubricating branch oil passage f1 and the second brake lubricating oil increasing oil passage g, the lubricating oil additional supply oil passage c connected to the discharge oil passage b of the electric pump 22 causes the second brake BR2 to be supplied with lubricating oil having a fifth flow rate (extra large), which is larger than the fourth flow rate (large). Also, the lubricating oil supply control means 220 controls the second lubricating branch oil passage f2 so that lubricating oil having a second flow rate (small) is supplied to the first clutch CL1 to the third clutch CL3. That is, when the temperature of the second brake BR2, which is a friction engaging element for starting, is equal to or higher than the high temperature threshold Thigh, the lubricating oil supply control means 220 restricts the flow rate of the lubricating oil supplied to the lubricating portion by the second lubricating circuit constituted by the second lubricating branch oil passage f2. Also, the lubricating oil supply control means 220 increases the flow rate of the lubricating oil supplied to the friction engaging element for starting by the first lubricating circuit constituted by the first lubricating branch oil passage f1 and the second brake lubricating oil increasing oil passage g.

[0165] When the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is Pattern 6, the lubricating oil supply control means 220 refers to the table in which the lubricating oil supply pattern shown in FIG. 6 is set, and by the first lubricating branch oil passage f1 and the lubricating oil additional supply oil passage c connected to the discharge oil passage b of the electric pump 22, it controls so that lubricating oil with a sixth flow rate (large), which is larger than the first flow rate (small), is supplied to the second brake BR2. Further, in addition to the second lubricating branch oil passage f2, the lubricating oil supply control means 220 controls so that lubricating oil with a third flow rate (large), which is larger than the second flow rate, is supplied to the first clutch CL1 to the third clutch CL3 by the lubricating oil increment oil passage h for the first to third clutches.

[0166] Next, with reference to FIG. 9, the details of step S14 in FIG. 8 will be described. First, the lubricating oil supply control means 220 determines whether the temperature of the second brake BR2 is equal to or higher than the low temperature threshold value Tlow (for example, 110°C) (step S15). When the temperature of the second brake BR2 is equal to or higher than the low temperature threshold value Tlow (YES in step S15), the lubricating oil supply control means 220 executes step S21. On the other hand, when the temperature of the second brake BR2 is lower than the low temperature threshold value Tlow (NO in step S15), the lubricating oil supply control means 220 determines whether the input rotational speed is equal to or higher than a predetermined value Nin (for example, 3000 rpm) (step S16).

[0167] When the input rotational speed is equal to or higher than the predetermined value Nin (for example, 3000 rpm) (YES in step S16), the lubricating oil supply control means 220 determines that the lubricating oil supply pattern is Pattern 2 (step S27). On the other hand, when the input rotational speed is lower than the predetermined value Nin (NO in step S16), the lubricating oil supply control means 220 determines whether the input torque is equal to or higher than a predetermined value Tq1 (for example, 320 Nm) (step S17).

[0168] When the input torque is equal to or greater than a predetermined value Tq1 (YES in step S17), the lubricating oil supply control means 220 determines the lubricating oil supply pattern as pattern 2 (step S27). On the other hand, when the input torque is less than the predetermined value Tq1 (NO in step S17), the lubricating oil supply control means 220 determines whether the temperature of the first clutch CL1 is equal to or higher than a predetermined value Tcl1 (e.g., 135°C) (step S18).

[0169] When the temperature of the first clutch CL1 is equal to or higher than the predetermined value Tcl1 (YES in step S18), the lubricating oil supply control means 220 determines the lubricating oil supply pattern as pattern 2 (step S27). On the other hand, when the temperature of the first clutch CL1 is less than the predetermined value Tcl1 (NO in step S18), the lubricating oil supply control means 220 determines whether the temperature of the second clutch CL2 is equal to or higher than a predetermined value Tcl2 (e.g., 135°C) (step S19).

[0170] When the temperature of the second clutch CL2 is equal to or higher than the predetermined value Tcl2 (YES in step S19), the lubricating oil supply control means 220 determines the lubricating oil supply pattern as pattern 2 (step S27). On the other hand, when the temperature of the second clutch CL2 is less than the predetermined value Tcl2 (NO in step S19), the lubricating oil supply control means 220 determines whether the temperature of the third clutch CL3 is equal to or higher than a predetermined value Tcl3 (e.g., 135°C) (step S20).

[0171] When the temperature of the third clutch CL3 is equal to or higher than the predetermined value Tcl3 (YES in step S20), the lubricating oil supply control means 220 determines the lubricating oil supply pattern as pattern 1 (step S26). On the other hand, when the temperature of the third clutch CL3 is less than the predetermined value Tcl3 (NO in step S20), the lubricating oil supply control means 220 determines the lubricating oil supply pattern as pattern 2 (step S27).

[0172] That is, when the temperature of the second brake BR2 is lower than the low temperature threshold value Tlow, the input rotational speed is lower than the predetermined value Nin, the input torque is lower than the predetermined value Tq1, and the first to third clutches CL1, CL2, and CL3 are lower than the predetermined values Tcl1, Tcl2, and Tcl3 (all of steps S15 to S20 are NO), the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 1. On the other hand, when the temperature of the second brake BR2 is lower than the low temperature threshold value Tlow and any one of the input rotational speed, the input torque, and the temperatures of the first to third clutches CL1, CL2, and CL3 is equal to or higher than the predetermined value (step S15 is NO and any one of steps S16 to S20 is YES), the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 2.

[0173] Returning to FIG. 9, the description will be continued. When the temperature of the second brake BR2 is equal to or higher than the low temperature threshold value Tlow (YES in step S15), the lubricating oil supply control means 220 determines whether the input rotational speed is equal to or higher than the predetermined value Nin (for example, 3000 rpm) (step S21). When the input rotational speed is equal to or higher than the predetermined value Nin (YES in step S21), the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 4 (step S29). On the other hand, when the input rotational speed is lower than the predetermined value Nin (NO in step S21), the lubricating oil supply control means 220 determines whether the input torque is equal to or higher than the predetermined value Tq1 (for example, 320 Nm) (step S22).

[0174] When the input torque is equal to or greater than a predetermined value Tq1 (YES in step S22), the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 4 (step S29). On the other hand, when the input torque is less than the predetermined value Tq1 (NO in step S22), the lubricating oil supply control means 220 determines whether the temperature of the first clutch CL1 is equal to or higher than a predetermined value Tcl1 (for example, 135°C) (step S23). When the temperature of the first clutch CL1 is equal to or higher than the predetermined value Tcl1 (YES in step S23), the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 4 (step S29). On the other hand, when the temperature of the first clutch CL1 is less than the predetermined value Tcl1 (NO in step S23), the lubricating oil supply control means 220 determines whether the temperature of the second clutch CL2 is equal to or higher than a predetermined value Tcl2 (for example, 135°C) (step S24).

[0175] When the temperature of the second clutch CL2 is equal to or higher than the predetermined value Tcl2 (YES in step S24), the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 4 (step S29). On the other hand, when the temperature of the second clutch CL2 is less than the predetermined value Tcl2 (NO in step S24), the lubricating oil supply control means 220 determines whether the temperature of the third clutch CL3 is equal to or higher than a predetermined value Tcl3 (for example, 135°C) (step S25).

[0176] When the temperature of the third clutch CL3 is equal to or higher than the predetermined value Tcl3 (YES in step S25), the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 4 (step S29). On the other hand, when the temperature of the third clutch CL3 is less than the predetermined value Tcl3 (NO in step S25), the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 4 (step S28).

[0177] That is, when the temperature of the second brake BR2 is equal to or higher than the threshold value Tlow, the input rotation speed is less than the predetermined value Nin, the input torque is less than the predetermined value Tq1, and the first to third clutches CL1, CL2, and CL3 are less than the predetermined values Tcl1, Tcl2, and Tcl3 (step S15 is YES and all of steps S16 to S20 are NO), the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 3.

[0178] On the other hand, when the temperature of the second brake BR2 is equal to or higher than the low temperature threshold value Tlow and any one of the input rotation speed, the input torque, and the temperatures of the first to third clutches CL1 to CL3 is equal to or higher than the predetermined value (step S15 is YES and any one of steps S16 to S20 is YES), the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 4.

[0179] Next, the details of step S30 will be described with reference to FIG. 10. FIG. 10 is an example of an operation for determining the lubricating oil supply pattern during the towing mode.

[0180] The lubricating oil supply control means 220 determines whether the ATF temperature is equal to or higher than the predetermined temperature Tatf (for example, 105°C) (step S31). When the ATF temperature is less than the predetermined temperature Tatf (NO in step S31), the lubricating oil supply control means 220 sets the high temperature threshold value Thigh to the first threshold value Thigh1 (for example, 200°C) (step S32). On the other hand, when the ATF temperature is equal to or higher than the predetermined temperature Tatf (YES in step S31), the lubricating oil supply control means 220 sets the high temperature threshold value Thigh to the second threshold value Thigh2 (for example, 270°C) higher than the first threshold value Thigh1 (step S33). That is, the lubricating oil supply control means 220 changes the high temperature threshold value Thigh according to the ATF temperature, which is the temperature of the lubricating oil. In other words, the lubricating oil supply control means 220 controls the high temperature threshold value Thigh to increase as the ATF temperature increases.

[0181] Next, the lubricating oil supply control means 220 determines whether the temperature of the second brake BR2 is equal to or higher than the high temperature threshold value Thigh (step S34). That is, the lubricating oil supply control means 220 determines whether the temperature of the second brake BR2, which is a friction engagement element for starting, is equal to or higher than the high temperature threshold value Thigh.

[0182] When the temperature of the second brake BR2 is equal to or higher than the high temperature threshold value Thigh (YES in step S34), the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 5 (step S36).

[0183] On the other hand, when the temperature of the second brake BR2 is lower than the high temperature threshold value Thigh (NO in step S34), the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 6 (step S35).

[0184] Here, with reference to FIG. 11, the lubricating oil supply pattern in the towing mode determined by the lubricating oil supply control means 220 will be described according to the operation example of FIG. 10. It is a map showing an example of the content of the lubricating oil supply pattern determination step in the flowchart of FIG. 10. As shown in FIG. 11, when the ATF temperature is lower than the predetermined temperature Tatf and the temperature of the second brake BR2, which is a friction engagement element for starting, is equal to or higher than the first threshold value Thigh1, the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 5. Also, when the ATF temperature is equal to or higher than the predetermined temperature Tatf and the temperature of the second brake BR2, which is a friction engagement element for starting, is equal to or higher than the second threshold value Thigh2, the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 5.

[0185] Here, as shown in FIGS. 4 and 5, the first lubrication circuit is connected to the electric pump 22. In other words, the electric pump 22 is connected to the first lubrication branch circuit f1 and the second brake lubricating oil increasing oil passage g. In particular, in the towing mode and when the temperature of the second brake BR2 is equal to or higher than the medium temperature threshold value Tmid, in addition to the lubricating oil supplied from the mechanical pump 21 by the first lubrication branch oil passage f1 and the second brake lubricating oil increasing oil passage g, lubricating oil is also supplied from the electric pump 22 to the second brake BR2 through the lubricating oil additional supply oil passage c. Thereby, since the second brake BR2 can be appropriately cooled, the durability of the second brake BR2 can be ensured.

[0186] Also, when the ATF temperature is less than the predetermined temperature Tatf and the temperature of the second brake BR2, which is a friction engagement element for starting, is equal to or higher than the medium temperature threshold value Tmid and less than the first threshold value Thigh1, the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 6. When the ATF temperature is equal to or higher than the predetermined temperature Tatf and the temperature of the second brake BR2, which is a friction engagement element for starting, is equal to or higher than the medium temperature threshold value Tmid and less than the second threshold value Thigh2, the lubricating oil supply control means 220 determines (decides) that the lubricating oil supply pattern is pattern 6.

[0187] As described above, according to the automatic transmission 10 according to the present embodiment, the hydraulic control device 2 switches the lubricating oil supply pattern according to the temperature of the second brake BR2, the input torque, the input rotational speed, and the temperatures of the first clutch CL1 to the third clutch CL3. That is, by using the hydraulic control device 2, an appropriate amount of lubricating oil can be supplied to the second brake BR2 and the first clutch CL1 to the third clutch CL3 according to the state of the vehicle. Therefore, by using the automatic transmission 10 provided with the hydraulic control device 2, normally with a focus on fuel efficiency, while reducing the amount of lubricating oil to the second brake BR2 and the first clutch CL1 to the third clutch CL3, an amount of lubricating oil necessary for each of the second brake BR2 and the first clutch CL1 to the third clutch CL3 can be supplied as needed. Therefore, according to the automatic transmission 10 provided with the hydraulic control device 2, it is possible to achieve both an improvement in fuel efficiency of the entire transmission considering the state of the vehicle and ensuring durability based on the temperature of each friction engagement element and the lubricating oil.

[0188] Further, since the hydraulic control device 2 uses the temperature of the second brake BR2, which is a parameter more directly related to the heat load, to switch the amount of lubricating oil for the second brake BR2, which is severe against heat generation, the supply amount of the lubricating oil can be appropriately set.

[0189] Furthermore, the hydraulic control device 2 changes the high-temperature threshold value Thigh of the second brake BR2 according to the ATF temperature, and changes the lubricating oil supply pattern according to the relationship between the temperature of the second brake BR2 and the high-temperature threshold value Thigh. Specifically, when the towing mode is set by the towing mode setting unit 209, the hydraulic control device 2 controls to change the high-temperature threshold value Thigh according to the temperature of the lubricating oil detected by the oil temperature sensor 205. Thereby, the hydraulic control device 2 can achieve both suppression of the temperature rise of the second brake BR2 and suppression of the temperature rise of the ATF temperature, and can ensure the durability of the starting friction engagement element and the internal components affected by the lubricating oil temperature.

[0190] Further, when the lubricating oil is at a high temperature, the hydraulic control device 2 controls the high-temperature threshold Thigh of the second brake BR2 to be set to a second threshold Thigh2 higher than the first threshold Thigh1, narrowing the temperature range in which pattern 5 is selected and widening the temperature range in which pattern 6 is selected compared to when the lubricating oil is at a medium or low temperature. In other words, when the temperature of the lubricating oil is equal to or higher than a predetermined temperature Tatf, the hydraulic control device 2 sets the high-temperature threshold Thigh of the second brake BR2 to a second threshold Thigh2 higher than the first threshold Thigh1 so that pattern 6 for suppressing the temperature rise of the lubricating oil is more likely to be selected compared to when the temperature of the lubricating oil is lower than the predetermined temperature Tatf.

[0191] On the other hand, when the lubricating oil is at a medium or low temperature, the hydraulic control device 2 controls the high-temperature threshold Thigh of the second brake BR2 to be set to the first threshold Thigh1, narrowing the temperature range in which pattern 6 is selected and widening the temperature range in which pattern 5 is selected compared to when the lubricating oil is at a medium or low temperature. In other words, when the temperature of the lubricating oil is lower than a predetermined temperature Tatf, the hydraulic control device 2 sets the high-temperature threshold Thigh of the second brake BR2 to the first threshold Thigh1 so that pattern 5 for suppressing the temperature rise of the second brake BR2 is more likely to be selected compared to when the temperature of the lubricating oil is equal to or higher than the predetermined temperature Tatf. Further, the hydraulic control device 2 sets the high-temperature threshold Thigh to either one of the two thresholds, the first threshold Thigh1 and the second threshold Thigh2, so as to efficiently achieve both the suppression of the temperature rise of the second brake BR2 and the lubricating oil without complicating the control. Therefore, according to the hydraulic control device 2, it is possible to efficiently achieve both the suppression of the temperature rise of the second brake BR2 and the lubricating oil without complicating the control, and to ensure the durability of the second brake BR2 and the lubricating oil.

[0192] As described above, the embodiments of the present invention have been explained, but the present invention is not limited to the illustrated embodiments, and various changes can be made without departing from the gist of the present invention. For example, the present embodiment may be modified as follows.

[0193] <Modification Example> In the above-described embodiment, the hydraulic control device 2 performs control to change the high-temperature threshold value Thigh according to the ATF temperature only when the towing mode is set. However, control to change the high-temperature threshold value Thigh according to the ATF temperature may be performed regardless of whether the towing mode is set. For example, before step S2 or in step S2 of FIG. 8, the running state of the accelerator hill hold may be detected by various sensors, and control to change the high-temperature threshold value Thigh according to the running state may be performed.

[0194] Further, in the present embodiment, when the ATF temperature is equal to or higher than a predetermined temperature Tatf (for example, 105°C), the hydraulic control device 2 changes from the two threshold values, the first threshold value Thigh1 (for example, 200°C) to the second threshold value Thigh2 (for example, 270°C). However, the number of threshold values used is not limited to two. For example, the hydraulic control device 2 may determine the high-temperature threshold value Thigh based on a function that calculates the high-temperature threshold value Thigh according to the ATF temperature. The function may be, for example, a function such that as the ATF temperature increases, the high-temperature threshold value Thigh also increases linearly, or a higher-order or non-linear function.

[0195] In the present embodiment, a configuration including a mechanical pump 21 driven by an engine and an electric pump 22 driven by electricity as a hydraulic power source has been described. However, the mechanical pump 21 may be replaced with the electric pump 22, and a configuration using only the electric pump 22 may be used.

[0196] Further, in the present embodiment, the hydraulic control device 2 determines the lubricating oil supply pattern based on whether the temperature of the second brake BR2, the input rotation speed, the input torque, and the temperatures of the first clutch CL1 to the third clutch CL3 are equal to or higher than predetermined threshold values. However, the hydraulic control device 2 may determine the lubricating oil supply pattern based on the input torque and the temperature of the second brake BR2. Alternatively, the hydraulic control device 2 may determine the lubricating oil supply pattern based on the input torque, the input rotation speed or the temperatures of the first clutch CL1 to the third clutch CL3, and the temperature of the second brake BR2.

[0197] Also, in the present embodiment, the hydraulic control device 2 calculates the temperature of each friction engagement element by calculation based on the detection values of various sensors. However, the automatic transmission 10 may be provided with a temperature sensor that detects the temperature of each friction engagement element, and the temperature may be directly detected by the temperature sensor. FIG. 12 is a configuration example of an automatic transmission according to a modified example. As shown in FIG. 12, in addition to the configuration of the automatic transmission 10, the automatic transmission 100 further includes each friction element temperature sensor 208. Each friction element temperature sensor 208 may detect the temperature of each of the friction engagement elements (the first clutch CL1 to the third clutch CL3, the first brake BR1, and the second brake BR2). Then, the lubricating oil supply control means 220 may perform control using the temperature detected by each friction element temperature sensor 208.

[0198] Also, in the above-described embodiment, the automatic transmission 10 has the orifice diameter increasing orifices 84 and 85, the lubricating oil increasing valves 34 and 35, and the fixed orifices 81, 82, and 83, which are increasing circuits for each friction engagement element, in order to increase the supply amount of the lubricating oil to each friction engagement element. However, instead of these, a variable orifice may be used to adjust the orifice diameter according to the driving state of the vehicle. By modifying in this way, the automatic transmission 10 can adjust the flow rates of the first lubrication circuit and the second lubrication circuit.

[0199] Also, in the above-described embodiment, the lubricating oil supply control means 220 determines the lubricating oil supply pattern based on the flowchart shown in FIG. 10 when the towing mode is set. However, the lubricating oil supply pattern may be determined based on the map shown in FIG. 11. In this case, the control unit 200 stores in advance in a storage unit (not shown) a determination map using the respective threshold values Thigh1 and Thigh2 of the temperature of the second brake BR2 and the predetermined temperature Tatf of the ATF shown in FIG. 11. Then, the lubricating oil supply control means 220 may determine the lubricating oil supply pattern by referring to the map shown in FIG. 11.

[0200] Further, in the above-described embodiment, the lubricating oil supply control means 220 executes either step S14 or S30 by comparing the input signal from the towing mode setting unit 209 with the temperature of the second brake BR2 calculated by each friction engagement element temperature calculating means 230 in step S3 shown in FIG. 8. However, the present invention is not limited to this, and the lubricating oil supply control means 220 may execute step S30 when it determines that the towing mode is set based on the input signal from the towing mode setting unit 209 in step S3.

Industrial Applicability

[0201] As described above, according to the present invention, in the control device of the automatic transmission, while suppressing the deterioration of fuel consumption performance, not only the durability of the starting friction engagement element is ensured, but also the temperature rise of the lubricating oil is suppressed, so that the durability of the entire automatic transmission including internal parts affected by the temperature of the lubricating oil can be ensured. Therefore, it may be suitably used in the field of manufacturing transmissions.

Explanation of Signs

[0202] 2 Hydraulic control device (lubrication control device) 10 Automatic transmission 20 Hydraulic control circuit 21 Mechanical pump 22 Electric pump 34 Lubricating oil increment valve for second brake (first on-off valve) 35 Lubricating oil increment valve for first to third clutches (second on-off valve) 91 Oil cooler 200 Control unit (control means) 230 Each friction engagement element temperature calculating means BR2 Second brake (starting friction engagement element) CL1~CL3 First clutch to third clutch (lubrication part) f1, g First lubrication circuit f1 First lubrication branch oil passage (first main lubrication circuit) g Lubricating oil increment oil passage for second brake (first lubricating oil increment circuit) f2, h Second lubrication circuit f2 Second lubrication branch oil passage (second main lubrication circuit) h Lubricating oil increment oil passage for first to third clutches (second lubricating oil increment circuit)

Claims

1. A lubrication control device for controlling the lubricating oil of an automatic transmission, comprising: A first lubrication circuit that supplies the lubricating oil to a starting friction engagement element that is engaged when the vehicle starts; A second lubrication circuit that supplies the lubricating oil to lubricating parts other than the starting friction engagement element; Control means for increasing the flow rate of the lubricating oil supplied by the first lubrication circuit while restricting the flow rate of the lubricating oil supplied by the second lubrication circuit when the temperature of the starting friction engagement element is equal to or higher than a threshold value; The control means is characterized in that the threshold value is changed according to the temperature of the lubricating oil. A lubrication control device.

2. The lubrication control device according to claim 1, wherein the control means controls such that the threshold value also increases as the temperature of the lubricating oil increases.

3. When the control means sets the threshold value when the temperature of the lubricating oil is less than a predetermined temperature as a first threshold value, the control means controls to set the threshold value when the temperature of the lubricating oil is equal to or higher than the predetermined temperature to a second threshold value higher than the first threshold value. The lubrication control device according to claim 1.

4. Further comprising an oil cooler for cooling the lubricating oil, The second lubrication circuit supplies the lubricating oil to the lubricating part via the oil cooler. The lubrication control device according to any one of claims 1 to 3.

5. Further comprising first supply means connected to the first lubrication circuit and the second lubrication circuit, The lubrication control device according to any one of claims 1 to 3, characterized in that the original pressure of the lubricating oil supplied by the first supply means is constant.

6. Further comprising second supply means connected to the first lubrication circuit, The lubrication control device according to claim 5, wherein the control means controls the second supply means to operate according to the temperature of the starting friction engaging element so as to supply the lubricating oil to the starting friction engaging element.

7. The first lubrication circuit includes a first main lubrication circuit that supplies the lubricating oil to the starting friction engaging element, and a first lubricating oil increasing circuit that branches off from the first main lubrication circuit. A first on-off valve is provided in the first lubricating oil increasing circuit. The lubrication control device according to any one of claims 1 to 3, wherein the first on-off valve is configured to increase the flow rate of the first lubrication circuit by changing from a closed state to an open state.

8. The second lubrication circuit includes a second main lubrication circuit that supplies the lubricating oil to the lubricating portion, and a second lubricating oil increasing circuit that branches off from the second main lubrication circuit. A second on-off valve is provided in the second lubricating oil increasing circuit. The lubrication control device according to any one of claims 1 to 3, wherein the second on-off valve is configured to limit the flow rate of the second lubrication circuit by changing from an open state to a closed state.

9. The lubrication control device further includes a towing mode setting unit. The control means controls the threshold value to be changed according to the temperature of the lubricating oil when the towing mode is set by the towing mode setting unit, according to any one of claims 1 to 3.

10. The first supply means is a mechanical pump that is mechanically driven by a drive source, according to the lubrication control device of claim 5.

11. The second supply means is an electric pump provided independently of the drive source, according to the lubrication control device of claim 6.

12. The lubrication control device according to any one of claims 1 to 3, characterized in that the starting friction engagement element is a brake that forms the first speed of the automatic transmission, starts the vehicle by slip control, and then enters a fastened state.

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