Vehicle control device

Abstract

To suitably determine an oil discharge flow rate of an oil pump.SOLUTION: A vehicle control device includes a hydraulic device provided in a power transmission passage for connecting a power source and a wheel, an oil pump connected to a hydraulic oil chamber of the hydraulic device and supplying oil to the hydraulic oil chamber, and a control valve provided in an oil passage for connecting the oil pump and the hydraulic oil chamber and controlling the oil supply to the hydraulic oil chamber. The vehicle control device further includes a control system having a processor and a memory connected communicably with each other and controlling the hydraulic device through the control valve. The control system determines an oil discharge flow rate of the oil pump on the basis of an elapsed time from when the control valve is controlled to start the oil supply to the hydraulic oil chamber until an operation state of the hydraulic device reaches a target state.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device provided in a vehicle. [Background technology]

[0002] Vehicles such as automobiles are equipped with hydraulic devices such as clutches, actuators, etc. In order to supply oil to these hydraulic devices, the vehicles are equipped with oil pumps that discharge oil (see Patent Documents 1 to 4). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-189765 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-294122 [Patent Document 3] JP 2019-49274 A [Patent Document 4] Japanese Patent Application Laid-Open No. 2011-236961 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the oil discharge flow rate of an oil pump may decrease due to deterioration over time. For this reason, oil pumps are often designed with a high discharge capacity to ensure that the oil flow consumed by each hydraulic device is sufficient even if the oil discharge flow rate of the oil pump decreases due to deterioration over time. However, designing an oil pump with a high discharge capacity unnecessarily increases the workload of the oil pump. For this reason, in order to properly operate hydraulic devices while designing the oil pump with a reduced discharge capacity, it is necessary to appropriately determine the oil discharge flow rate of the oil pump, which decreases with deterioration over time.

[0005] An object of the present invention is to appropriately determine the oil discharge flow rate of an oil pump. [Means for solving the problem]

[0006] A vehicle control device in one embodiment is a vehicle control device provided in a vehicle, and includes: a hydraulic device provided in a power transmission path connecting a power source and wheels; an oil pump connected to a hydraulic oil chamber of the hydraulic device and supplying oil to the hydraulic oil chamber; a control valve provided in an oil path connecting the oil pump and the hydraulic oil chamber and controlling the supply of oil to the hydraulic oil chamber; and a control system including a processor and a memory communicably connected to each other, and controlling the hydraulic device via the control valve. do. The control system determines the oil discharge flow rate of the oil pump based on the elapsed time from when the control valve is controlled to start supplying oil to the hydraulic oil chamber until the operating state of the hydraulic device reaches a target state. The control system determines that the oil discharge flow rate of the oil pump is smaller as the elapsed time is longer. [Effects of the Invention]

[0007] In one embodiment, the vehicle control device determines the oil discharge flow rate of the oil pump based on the elapsed time from when the control valve is controlled to start supplying oil to the hydraulic oil chamber until the operating state of the hydraulic device reaches a target state, thereby making it possible to appropriately determine the oil discharge flow rate. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing an example of the configuration of a vehicle provided with a vehicle control device according to an embodiment of the present invention; [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of a vehicle control device. [Figure 3] FIG. 2 is a diagram simply illustrating the basic structure of each control unit. [Figure 4] FIG. 2 is a circuit diagram showing an example of the configuration of a valve body. [Figure 5] FIG. 4 is a circuit diagram showing the flow of hydraulic oil in a full discharge mode. [Figure 6] FIG. 10 is a circuit diagram showing the flow of hydraulic oil in a half-discharge mode. [Figure 7] 10 is a flowchart illustrating an example of a procedure for executing discharge flow rate determination control. [Figure 8] FIG. 10 is a diagram illustrating an example of a pump coefficient set in the discharge flow rate determination control. [Figure 9] 10 is a timing chart showing an example of an execution state of discharge flow rate determination control. [Figure 10] 10 is a flowchart illustrating an example of a procedure for executing mode switching control. [Figure 11] FIG. 4 is a diagram illustrating an example of an oil consumption flow rate used in mode switching control. [Figure 12] FIG. 4 is a diagram illustrating an example of an oil consumption flow rate used in mode switching control. [Figure 13] FIG. 10 is a diagram illustrating an example of a reference discharge flow rate used in mode switching control. [Figure 14] 4 is a timing chart showing an example of an execution state of mode switching control. [Figure 15] FIG. 4 is a diagram showing the relationship between the oil discharge flow rate and the oil consumption flow rate. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, identical or substantially identical configurations and elements will be designated by the same reference numerals and will not be described repeatedly.

[0010] [Vehicle configuration] Fig. 1 is a diagram showing an example of the configuration of a vehicle 11 provided with a vehicle control device 10 according to an embodiment of the present invention, and Fig. 2 is a diagram showing an example of the configuration of the vehicle control device 10. As shown in Figs. 1 and 2, the vehicle 11 is equipped with a powertrain 14 consisting of an engine 12 and a transmission 13. Wheels 18 are connected to an output shaft 15 of the powertrain 14 via a propeller shaft 16 and a differential mechanism 17.

[0011] 2, the transmission 13 that constitutes the powertrain 14 is provided with a torque converter 20, a forward / reverse switching mechanism 21, and a continuously variable transmission mechanism 22. That is, the forward / reverse switching mechanism 21 and the continuously variable transmission mechanism 22 are provided in a power transmission path 23 that connects the engine (power source) 12 and the wheels 18. This power transmission path 23 is made up of the torque converter 20, the forward / reverse switching mechanism 21, the continuously variable transmission mechanism 22, the output shaft 15, the propeller shaft 16, the differential mechanism 17, etc. Note that the illustrated powertrain 14 is a rear-wheel drive powertrain, but is not limited to this and may be a front-wheel drive or all-wheel drive powertrain.

[0012] 2, an intake manifold 30 of the engine 12 is provided with a throttle valve 31 that adjusts the amount of intake air. The engine 12 is also provided with an injector 32 that injects fuel into the intake ports and cylinders, and an ignition device 33 consisting of an igniter, spark plugs, etc. A starter motor 35 is connected to a crankshaft 34 of the engine 12 via a front cover 40 of the torque converter 20, which will be described later. An engine control unit 36 ​​is connected to the throttle valve 31, injector 32, ignition device 33, starter motor 35, etc. to control the operating state of the engine 12.

[0013] The torque converter 20 of the transmission 13 has a pump impeller 41 connected to the crankshaft 34 of the engine 12 via a front cover 40, and a turbine runner 43 facing the pump impeller 41 and connected to a turbine shaft 42. An oil pump 45 is connected to the pump impeller 41 of the torque converter 20 via a chain mechanism 44. That is, in the example shown, the oil pump 45 is directly connected to the engine 12, and is driven when the engine is running, but is stopped when the engine is stopped. The torque converter 20 is provided with a lock-up clutch 46 that directly connects the front cover 40 and the turbine runner 43.

[0014] The forward / reverse switching mechanism 21 of the transmission 13 includes a double-pinion planetary gear train 50, a forward clutch 51 that connects a sun gear 50s and a carrier 50c of the planetary gear train 50 to each other, and a reverse clutch 53 that secures a ring gear 50r of the planetary gear train 50 to a transmission case 52. When the driver operates a selector lever 108 (described later) to select a forward range (driving range), i.e., the D range, the forward clutch 51 is engaged and the reverse clutch 53 is disengaged. This allows the sun gear 50s on the input side and the carrier 50c on the output side to rotate integrally, thereby rotating the primary shaft 80 of the continuously variable transmission mechanism 22 in the forward direction. On the other hand, when the driver operates the selector lever 108 to select a reverse range (driving range), i.e., the R range, the reverse clutch 53 is engaged and the forward clutch 51 is disengaged. This allows the rotation directions of the input-side sun gear 50s and the output-side carrier 50c to be reversed, allowing the primary shaft 80 of the continuously variable transmission mechanism 22 to rotate in the reverse direction.

[0015] As described above, since the forward / reverse switching mechanism 21 is provided in the power transmission path 23, the forward clutch 51 is a clutch (hydraulic device) provided in the power transmission path 23. The forward clutch 51 has a clutch drum 60 connected to the turbine shaft 42 of the torque converter 20 and a clutch hub 61 connected to the carrier 50c of the planetary gear train 50. A plurality of friction plates 62, 63 are provided between the clutch drum 60 and the clutch hub 61, and the clutch drum 60 houses a piston 64 that engages the friction plates 62, 63. A clutch oil chamber (hydraulic oil chamber) 65 is defined between the clutch drum 60 and the piston 64, and the friction plates 62, 63 can be engaged with each other by supplying hydraulic oil to this clutch oil chamber 65 and pushing out the piston 64. In other words, by supplying hydraulic oil to the clutch oil chamber 65 of the forward clutch 51, the forward clutch 51 is switched from a released state to an engaged state, and the sun gear 50s and the carrier 50c of the planetary gear train 50 are engaged with each other.

[0016] Furthermore, since the forward / reverse switching mechanism 21 is provided in the power transmission path 23, the reverse clutch 53 is a clutch provided in the power transmission path 23. The reverse clutch 53 has a clutch drum 70 fixed to the transmission case 52 and a clutch hub 71 connected to the ring gear 50r of the planetary gear train 50. A plurality of friction plates 72, 73 are provided between the clutch drum 70 and the clutch hub 71, and the clutch drum 70 houses a piston 74 that fastens the friction plates 72, 73 together. A clutch oil chamber 75 is defined between the clutch drum 70 and the piston 74, and the friction plates 72, 73 can be fastened together by supplying hydraulic oil to the clutch oil chamber 75 and pushing out the piston 74. In other words, by supplying hydraulic oil to the clutch oil chamber 75 of the reverse clutch 53, the reverse clutch 53 is switched from a released state to an engaged state, and the ring gear 50r of the planetary gear train 50 is fixed to the transmission case 52.

[0017] The continuously variable transmission mechanism 22 of the transmission 13 has a primary pulley 81 provided on a primary shaft 80 and a secondary pulley 83 provided on a secondary shaft 82. A drive chain 84 that transmits power between the pulleys 81, 83 is wound around the primary pulley 81 and the secondary pulley 83. The primary pulley 81 has a fixed sheave 81a fixed to the primary shaft 80 and a movable sheave 81b that is provided on the primary shaft 80 so as to be movable in the axial direction. A primary oil chamber 85 is defined on the back side of the movable sheave 81b, and by controlling the hydraulic pressure supplied to this primary oil chamber 85, the movable sheave 81b can be moved to change the groove width between the sheaves 81a, 81b.

[0018] Similarly, secondary pulley 83 has a fixed sheave 83a fixed to secondary shaft 82, and a movable sheave 83b provided on secondary shaft 82 so as to be movable in the axial direction. A secondary oil chamber 86 is defined on the back side of movable sheave 83b, and by controlling the hydraulic oil pressure supplied to this secondary oil chamber 86, movable sheave 83b can be moved to change the groove width between sheaves 83a, 83b. In other words, by controlling the hydraulic oil pressure for primary oil chamber 85 and secondary oil chamber 86, the pulley groove width can be changed to change the winding diameter of drive chain 84, and the speed of continuously variable transmission mechanism 22 can be changed.

[0019] The vehicle 11 is equipped with a hydraulic system 90 to control the forward / reverse switching mechanism 21, the continuously variable transmission mechanism 22, and the like. The hydraulic system 90 includes an oil pump 45 that discharges hydraulic oil stored in an oil pan 91, a valve body 92 that includes a plurality of electromagnetic valves, oil passages, and the like, and a mission control unit 93 that outputs control signals to the valve body 92. The hydraulic oil pumped from the oil pump 45 passes through the valve body 92, where its supply destination, pressure, and the like are controlled, and is then supplied to the forward / reverse switching mechanism 21, the continuously variable transmission mechanism 22, and the like. The hydraulic oil supplied from the oil pump 45 to the forward / reverse switching mechanism 21, the continuously variable transmission mechanism 22, and the like is also called ATF (Automatic Transmission Fluid).

[0020] [Control System] As shown in FIG. 2 , the vehicle control device 10 is provided with a control system 95 consisting of multiple electronic control units to control the powertrain 14 and the like. The electronic control units constituting the control system 95 include the engine control unit 36 ​​and the transmission control unit 93 described above, as well as a vehicle control unit 96 that outputs control signals to these control units 36 and 93. These control units 36, 93, and 96 are communicatively connected to one another via an in-vehicle network 97 such as CAN or LIN. The vehicle control unit 96 sets operation targets for the engine 12, the transmission 13, and the like based on input information from the various control units 36, 93, and 96 and various sensors described below. The vehicle control unit 96 then generates control signals corresponding to the operation targets of the engine 12, the transmission 13, and the like, and outputs these control signals to the various control units 36 and 93.

[0021] Sensors connected to the vehicle control unit 96 include a vehicle speed sensor 100 that detects the vehicle speed, which is the traveling speed of the vehicle 11, an accelerator sensor 101 that detects the amount of accelerator pedal operation, and a brake sensor 102 that detects the amount of brake pedal operation. Other sensors connected to the vehicle control unit 96 include an engine rotation sensor 103 that detects the engine rotation speed, which is the rotation speed of the crankshaft 34, and a turbine rotation sensor 104 that detects the turbine rotation speed, which is the rotation speed of the turbine shaft 42. Other sensors connected to the vehicle control unit 96 include a primary rotation speed sensor 105 that detects the primary rotation speed, which is the rotation speed of the primary pulley 81, and a secondary rotation speed sensor 106 that detects the secondary rotation speed, which is the rotation speed of the secondary pulley 83. A push switch 107 that is operated by the driver to start the control system 95 is also connected to the vehicle control unit 96. A selector lever 108 that is operated by the driver to select a driving range (D range, R range) or a parking range (P range) is also connected to the vehicle control unit 96.

[0022] Fig. 3 is a diagram simply illustrating the basic structure of each of the control units 36, 93, and 96. As shown in Fig. 3, each of the control units 36, 93, and 96 has a microcontroller 112 incorporating a processor 110, a memory 111, and the like. A predetermined program is stored in the memory 111, and an instruction set of the program is executed by the processor 110. The processor 110 and the memory 111 are connected to each other so that they can communicate with each other. In the illustrated example, one processor 110 and one memory 111 are incorporated in the microcontroller 112, but this is not limiting. Multiple processors 110 may be incorporated in the microcontroller 112, and multiple memories 111 may be incorporated in the microcontroller 112.

[0023] Each control unit 36, 93, 96 is also provided with an input conversion circuit 113, a drive circuit 114, a communication circuit 115, an external memory 116, a power supply circuit 117, and the like. The input conversion circuit 113 converts signals input from various sensors into signals that can be input to the microcontroller 112. The drive circuit 114 generates drive signals for actuators such as the valve body 92 based on signals output from the microcontroller 112. The communication circuit 115 converts signals output from the microcontroller 112 into communication signals directed to other control units. The communication circuit 115 also converts communication signals received from other control units into signals that can be input to the microcontroller 112. The power supply circuit 117 supplies a stable power supply voltage to the microcontroller 112, the input conversion circuit 113, the drive circuit 114, the communication circuit 115, the external memory 116, and the like. The external memory 116, such as a nonvolatile memory, stores data that should be retained even when power is off.

[0024] [Valve body] Next, the valve body 92 constituting the hydraulic system 90 will be described. FIG. 4 is a circuit diagram showing an example of the configuration of the valve body 92. As shown in FIG. 4, the valve body 92 is connected to an oil pump 45 driven by the engine 12. The oil pump 45 is provided with a pair of suction ports 120, 121 and a pair of discharge ports 122, 123. An intake oil passage 124 is connected to the suction ports 120, 121 of the oil pump 45, and an oil strainer 125 disposed in the oil pan 91 is connected to one end of the intake oil passage 124. A line pressure passage 127 is connected to the discharge port 122 of the oil pump 45 via a discharge oil passage 126, and a line pressure control valve 128 is connected to the line pressure passage 127, which adjusts the line pressure as the basic hydraulic pressure. The line pressure control valve 128 adjusts the line pressure based on the required driving force for the vehicle 11, etc. Furthermore, the hydraulic oil discharged from the line pressure control valve 128 during pressure adjustment is guided from a discharge oil passage 129 to the oil pan 91 via a lubrication section 130 .

[0025] A branch oil passage 131 leading to the forward clutch 51 and the reverse clutch 53 is connected to the line pressure passage 127, through which hydraulic oil adjusted to the line pressure flows. A clutch pressure control valve (control valve) 132 is connected to this branch oil passage 131, and a switch valve (control valve) 134 is connected to a clutch pressure passage 133 extending from the clutch pressure control valve 132. The switch valve 134 is connected to the clutch oil chamber 65 of the forward clutch 51 via a forward oil passage 135, and to the clutch oil chamber 75 of the reverse clutch 53 via a reverse oil passage 136. The clutch pressure control valve 132 adjusts the clutch pressure supplied to the clutch oil chamber 75 of the forward clutch 51 or the reverse clutch 53, and the switch valve 134 connects the clutch pressure passage 133 to the forward oil passage 135 or the reverse oil passage 136.

[0026] Furthermore, a branch oil passage 137 leading to primary pulley 81 is connected to line pressure passage 127, and primary oil chamber 85 is connected to this branch oil passage 137 via a primary pressure control valve 138. Furthermore, a branch oil passage 139 leading to secondary pulley 83 is connected to line pressure passage 127, and secondary oil chamber 86 is connected to this branch oil passage 139. Note that, in order to control the gear ratio of continuously variable transmission mechanism 22, primary pressure control valve 138 adjusts the primary pressure supplied to primary oil chamber 85 based on the target gear ratio, line pressure, etc.

[0027] The illustrated line pressure control valve 128, clutch pressure control valve 132, switch valve 134, and primary pressure control valve 138 are pilot-operated valves controlled by pilot pressure. A solenoid valve 128a that controls the supply of pilot pressure is connected to the line pressure control valve 128, and the line pressure control valve 128 adjusts the line pressure based on the pilot pressure from this solenoid valve 128a. Also, a solenoid valve 132a that controls the supply of pilot pressure is connected to the clutch pressure control valve 132, and the clutch pressure control valve 132 adjusts the clutch pressure based on the pilot pressure from this solenoid valve 132a.

[0028] Furthermore, a solenoid valve 134a that controls the supply of pilot pressure is connected to the switch valve 134, and based on the pilot pressure from this solenoid valve 134a, the switch valve 134 connects the clutch pressure path 133 to a forward oil path 135 or a reverse oil path 136. Furthermore, a solenoid valve 138a that controls the supply of pilot pressure is connected to the primary pressure control valve 138, and based on the pilot pressure from this solenoid valve 138a, the primary pressure control valve 138 adjusts the primary pressure.

[0029] As shown in Fig. 4, a mode switching valve 141 is connected to the discharge port 123 of the oil pump 45 via a discharge oil passage 140. The operation mode of the oil pump 45 can be switched by controlling this mode switching valve 141. As will be described later, the oil pump 45 has two operation modes: a full discharge mode and a half discharge mode. The full discharge mode is an operation mode in which hydraulic oil is supplied from both discharge ports 122, 123 of the oil pump 45 to the line pressure passage 127. The half discharge mode is an operation mode in which hydraulic oil is supplied from one discharge port 122 of the oil pump 45 to the line pressure passage 127.

[0030] The mode switching valve 141 has a housing 150 and a spool 151 movably accommodated therein. The housing 150 of the mode switching valve 141 is formed with an input port 152, an output port 153, and a discharge port 154. The input port 152 of the housing 150 is connected to the discharge port 123 of the oil pump 45 via a discharge oil passage 140. The output port 153 of the housing 150 is connected to the line pressure passage 127, and the discharge port 154 of the housing 150 is connected to the lubrication unit 130 via a discharge oil passage 129. In addition, in order to operate the spool 151 of the mode switching valve 141, a spring member 155 is attached to one end of the spool 151, and a pilot pressure chamber 156 is defined at the other end of the spool 151. A pilot port 157 communicating with the pilot pressure chamber 156 is formed in the housing 150, and a solenoid valve 141a that controls the supply of pilot pressure is connected to this pilot port 157.

[0031] [Full discharge mode, half discharge mode] The full-discharge mode and half-discharge mode of the oil pump 45 will now be described. FIG. 5 is a circuit diagram showing the flow of hydraulic oil in the full-discharge mode, and FIG. 6 is a circuit diagram showing the flow of hydraulic oil in the half-discharge mode. As shown in FIG. 5, when the oil pump 45 is operated in the full-discharge mode, the transmission control unit 93 controls the electromagnetic valve 141a, thereby supplying pilot fluid (hydraulic oil) from the electromagnetic valve 141a to the pilot pressure chamber 156 of the mode switching valve 141. This increases the pilot pressure in the pilot pressure chamber 156, causing the spool 151 to move in the direction of arrow S1 against the spring force of the spring member 155. By moving the spool 151 in the direction of arrow S1 in this way, the input port 152 and the output port 153 of the mode switching valve 141 can be connected to each other.

[0032] As a result, as shown by dashed arrow b1, hydraulic oil discharged from discharge port 123 of oil pump 45 is supplied from discharge oil passage 140 through mode switching valve 141 to line pressure passage 127, and is supplied toward forward / reverse switching mechanism 21, continuously variable transmission mechanism 22, etc. Also, as shown by solid arrow a1, hydraulic oil discharged from discharge port 122 of oil pump 45 is supplied from discharge oil passage 140 to line pressure passage 127, and is supplied toward forward / reverse switching mechanism 21, continuously variable transmission mechanism 22, etc. In this way, in the full discharge mode, hydraulic oil is supplied to line pressure passage 127 from both discharge ports 122, 123 of oil pump 45.

[0033] 6, when the oil pump 45 is operated in the half-discharge mode, the transmission control unit 93 controls the electromagnetic valve 141a to discharge pilot fluid from the pilot pressure chamber 156 of the mode switching valve 141 through the electromagnetic valve 141a. This reduces the pilot pressure in the pilot pressure chamber 156, and the spring force of the spring member 155 moves the spool 151 in the direction of arrow S2. By moving the spool 151 in the direction of arrow S2 in this way, the input port 152 and the discharge port 154 of the mode switching valve 141 can be connected to each other.

[0034] As a result, as indicated by dashed arrow b1, hydraulic oil discharged from discharge port 123 of oil pump 45 is supplied from discharge oil passage 140 through mode switching valve 141 to discharge oil passage 129, and then guided from discharge oil passage 129 through lubrication section 130 to oil pan 91. In other words, hydraulic oil discharged from discharge port 123 of oil pump 45 is returned from lubrication section 130 to oil pan 91 without being supplied to line pressure passage 127. Also, as indicated by solid arrow a1, hydraulic oil discharged from discharge port 122 of oil pump 45 is supplied from discharge oil passage 140 to line pressure passage 127 and supplied toward forward / reverse switching mechanism 21, continuously variable transmission mechanism 22, etc. In this way, in the half-discharge mode, hydraulic oil is supplied to line pressure passage 127 from one discharge port 122 of oil pump 45.

[0035] In this way, by controlling the mode switching valve 141 to switch the flow direction of hydraulic oil, the operation mode of the oil pump 45 can be switched between full-discharge mode and half-discharge mode. Meanwhile, in full-discharge mode, a large amount of hydraulic oil can be supplied to the continuously variable transmission mechanism 22, etc., but there is a risk that the workload of the oil pump 45 will be unnecessarily increased depending on the operating conditions of the continuously variable transmission mechanism 22, etc. In contrast, in half-discharge mode, the workload of the oil pump 45 can be reduced to reduce the engine load, but there is a risk that the supply of hydraulic oil will be insufficient depending on the operating conditions of the continuously variable transmission mechanism 22, etc. Therefore, the control system 95 determines the amount of hydraulic oil consumed per unit time by the forward / reverse switching mechanism 21, the continuously variable transmission mechanism 22, etc. (hereinafter referred to as the oil consumption flow rate) based on the operating state of the powertrain 14. The control system 95 then executes the mode switching control described below, so that when the oil consumption flow rate of the continuously variable transmission mechanism 22, etc. is low, the oil pump 45 operates in half-discharge mode, and when the oil consumption flow rate of the continuously variable transmission mechanism 22, etc. is high, the oil pump 45 operates in full-discharge mode.

[0036] However, the flow rate of hydraulic oil discharged from the oil pump 45 (oil discharge flow rate) may decrease due to deterioration over time of the oil pump 45. In other words, even if the oil consumption flow rate of the continuously variable transmission mechanism 22, etc. is determined to be low and the oil pump 45 is operated in half-discharge mode, the oil discharge flow rate may be insufficient depending on the deterioration state of the oil pump 45, making it difficult to properly operate the continuously variable transmission mechanism 22, etc. Therefore, the control system 95 executes discharge flow rate determination control that determines the actual oil discharge flow rate at a predetermined timing in order to properly determine the feasible range of the half-discharge mode even when the oil discharge flow rate has decreased due to deterioration over time.

[0037] [Discharge flow rate determination control (flowchart)] The discharge flow rate determination control executed by the control system 95 will be described below. Fig. 7 is a flowchart showing an example of the execution procedure of the discharge flow rate determination control. Fig. 8 is a diagram showing an example of the pump coefficient kp set in the discharge flow rate determination control. Each step shown in the flowchart of Fig. 7 shows processing executed by one or more processors 110 that constitute the control system 95. The discharge flow rate determination control shown in Fig. 7 is control that is executed by the control system 95 after the control system 95, which includes the vehicle control unit 96 and the like, is started up.

[0038] As shown in Fig. 7, in step S10, it is determined whether or not the driver has performed an engine start operation. Here, the engine start operation refers to, for example, an operation in which the driver presses the push switch 107 while depressing the brake pedal with the selector lever 108 operated to the parking range (P range). If it is determined in step S10 that the engine start operation has been performed, the process proceeds to step S11, where it is determined whether or not the engine stop period exceeds a predetermined threshold value Ts1 (for example, several hours). Note that the threshold value Ts1 compared with the engine stop period is the time required for almost all of the hydraulic oil to be discharged from the clutch oil chamber 65 of the forward clutch 51 after the supply of hydraulic oil is cut off due to the stop of the oil pump 45.

[0039] If it is determined in step S11 that the engine stop period is equal to or less than the threshold value Ts1, the hydraulic oil is not being sufficiently discharged from the forward clutch 51, and the routine is terminated without determining the oil discharge flow rate. On the other hand, if it is determined in step S11 that the engine stop period is greater than the threshold value Ts1, the hydraulic oil is being sufficiently discharged from the forward clutch 51, and the routine proceeds to step S12, where it is determined whether or not engine starting by the starter motor 35 has been completed. If it is determined in step S12 that engine starting has been completed, the routine proceeds to step S13, where it is determined whether or not the driver has operated the selector lever 108 from "P range" to "D range."

[0040] In step S13, the situation in which it is determined that the selector lever 108 has been operated to the "D range" is the situation in which the "D range," which is the driving range, is selected for the first time after the engine 12, which has been stopped for more than the predetermined period Ts1, is started. In other words, this is the situation in which the oil pump 45, which has been stopped for more than the predetermined period Ts1, starts to operate, and the clutch pressure control valve 132 and the switch valve 134 are opened, thereby supplying hydraulic oil from the oil pump 45 to the clutch oil chamber 65 of the forward clutch 51. In other words, this is the situation in which the oil pump 45 starts to supply oil to the clutch oil chamber 65 of the forward clutch 51, which has been drained of hydraulic oil and is now almost empty. The clutch pressure control valve 132 and the switch valve 134 are control valves provided in the oil passage 160 that connects the oil pump 45 and the clutch oil chamber 65. An oil passage 160 connecting the oil pump 45 and the clutch oil chamber 65 is made up of discharge oil passages 126 and 140 , a line pressure passage 127 , a branch oil passage 131 , a clutch pressure passage 133 and a forward oil passage 135 .

[0041] Then, if it is determined in step S13 that the selector lever 108 has been operated to "D range," the process proceeds to step S14, where a timer count value reset process is executed to start measuring the engagement time TC of the forward clutch 51. In the following step S15, it is determined whether the turbine rotation speed Nt is below a predetermined threshold value N1. Here, a situation in which the forward clutch 51 is engaged while the vehicle is stopped means a situation in which the turbine shaft 42, which rotates at approximately the same speed as the engine rotation speed, is connected to the stopped primary shaft 80 via the forward clutch 51. For this reason, as the engagement force of the forward clutch 51 increases, the turbine rotation speed Nt decreases toward "zero."

[0042] If it is determined in step S15 that the turbine rotation speed Nt is equal to or greater than the threshold value N1, the forward clutch 51 has not yet been switched from the released state to the engaged state, and so the process proceeds to step S16, where a counting process for a timer count value is executed. On the other hand, if it is determined in step S15 that the turbine rotation speed Nt is below the threshold value N1, the forward clutch 51 has been switched from the released state to the engaged state (target state), and so the process proceeds to step S17, where an engagement time TC of the forward clutch 51 is calculated based on the timer count value. In the following step S18, a pump coefficient kp to be used in the mode switching control described below is set based on the engagement time TC of the forward clutch 51.

[0043] 8, a situation in which the engagement time TC of the forward clutch 51 is long means that the filling rate of hydraulic oil into the clutch oil chamber 65 of the forward clutch 51 is slow, and the oil discharge flow rate of the oil pump 45 is low. In other words, the longer the engagement time TC of the forward clutch 51, the lower the oil discharge flow rate of the oil pump 45 is determined to be, and the pump coefficient kp of the oil pump 45 is set to a smaller value. On the other hand, a situation in which the engagement time TC of the forward clutch 51 is short means that the filling rate of hydraulic oil into the clutch oil chamber 65 of the forward clutch 51 is fast, and the oil discharge flow rate of the oil pump 45 is high. In other words, the shorter the engagement time TC of the forward clutch 51, the higher the oil discharge flow rate of the oil pump 45 is determined to be, and the pump coefficient kp of the oil pump 45 is set to a larger value.

[0044] [Discharge flow rate determination control (timing chart)] The execution status of the above-mentioned discharge flow rate determination control will be described with reference to a timing chart. FIG. 9 is a timing chart showing an example of the execution status of the discharge flow rate determination control. The timing chart of FIG. 9 shows the status from when the engine 12, whose stop period has exceeded the predetermined period Ts1, is started, until the "D range" driving range is first selected and the forward clutch 51 is switched to the engaged state. The timing chart of FIG. 9 also shows, using a solid line, the status when an oil pump 45 that has not deteriorated over time is used, i.e., when an oil pump 45 with a large oil discharge flow rate is used. The timing chart of FIG. 9 also shows, using a dashed line, the status when an oil pump 45 that has deteriorated over time is used, i.e., when an oil pump 45 with a small oil discharge flow rate is used.

[0045] 9, the oil pump 45 is not deteriorating due to aging. As shown by the solid line in FIG. 9, when the selector lever 108 is shifted from "P" to "D" after the engine is first started (as indicated by a reference symbol a1), hydraulic oil begins to be supplied to the clutch oil chamber 65 of the forward clutch 51 (as indicated by a reference symbol b1). When the amount of hydraulic oil filled in the clutch oil chamber 65 (hereinafter referred to as the "oil fill amount") reaches a predetermined amount that presses the friction plates 62, 63 against each other (as indicated by a reference symbol b2), the turbine speed Nt begins to decrease in accordance with the engagement force of the forward clutch 51 (as indicated by a reference symbol c1). When the turbine speed Nt falls below a threshold value N1 (as indicated by a reference symbol c2) at time t2a, it is determined that the forward clutch 51 has been switched from the released state to the engaged state (as indicated by a reference symbol d1). When it is determined that the forward clutch 51 is engaged (as indicated by a reference symbol d1), the elapsed time TC1 from the start of oil supply is set as the engagement time of the forward clutch 51.

[0046] As shown by the dashed-dotted line in Figure 9, the oil pump 45 is now described as having deteriorated over time. When the oil pump 45 has deteriorated over time, the oil discharge flow rate of the oil pump 45 is low, causing the amount of oil filled into the clutch oil chamber 65 to increase gradually (see symbol e1). Therefore, at time t3a, which is later than the aforementioned time t2a, the turbine rotation speed Nt falls below the threshold value N1 (see symbol f1), and it is determined that the forward clutch 51 has switched from the released state to the engaged state (see symbol g1). When it is determined that the forward clutch 51 is in the engaged state (see symbol g1), the elapsed time TC2 from the start of oil supply is set as the engagement time of the forward clutch 51. In this way, when the oil pump 45 has deteriorated over time, the engagement time of the forward clutch 51 is longer than when the oil pump 45 has not deteriorated over time.

[0047] [Mode switching control (flowchart)] The mode switching control executed by the control system 95, that is, the mode switching control for switching the operation mode of the oil pump 45, will be described below. FIG. 10 is a flowchart showing an example of the execution procedure of the mode switching control. FIG. 11 is a diagram showing an example of an oil consumption flow rate Oca used in the mode switching control, and FIG. 12 is a diagram showing an example of an oil consumption flow rate Ocb used in the mode switching control. Furthermore, FIG. 13 is a diagram showing an example of a reference discharge flow rate OD2a used in the mode switching control. Each step shown in the flowchart of FIG. 10 represents processing executed by one or more processors 110 constituting the control system 95. The mode switching control shown in FIG. 10 is control executed by the control system 95, which includes the vehicle control unit 96 and the like, after the control system 95 is started.

[0048] As shown in FIG. 10 , in step S10, the oil consumption flow rate OC consumed by the torque converter 20, the forward / reverse switching mechanism 21, the continuously variable transmission mechanism 22, etc. is calculated based on the operating state of the powertrain 14. Here, the oil consumption flow rate OC of the transmission 13 is calculated by adding the steadily consumed oil consumption flow rate Oca and the temporarily consumed oil consumption flow rate Ocb. As shown in FIG. 11 , the steadily consumed oil consumption flow rate Oca is calculated based on, for example, the engine speed and the line pressure. The oil consumption flow rate Oca is set to decrease as the engine speed decreases and to increase as the engine speed increases. Furthermore, the oil consumption flow rate Oca is set to decrease as the line pressure decreases and to increase as the line pressure increases. Furthermore, as shown in FIG. 12 , the temporarily consumed oil consumption flow rate Ocb is calculated based on, for example, the operating states of the forward / reverse switching mechanism 21 and the continuously variable transmission mechanism 22. That is, when the forward clutch 51 is switched from a released state to an engaged state, or when the reverse clutch 53 is switched from a released state to an engaged state, an oil consumption flow rate Ocb is set that corresponds to the forward clutch 51 or the reverse clutch 53. Furthermore, when the continuously variable transmission mechanism 22 is upshifted or downshifted, an oil consumption flow rate Ocb that corresponds to the gear position before and after the shift is set.

[0049] As shown in FIG. 10, in step S21, a reference discharge flow rate OD2a in the half-discharge mode of the oil pump 45 is calculated. The reference discharge flow rate OD2a of the oil pump 45 is the flow rate of hydraulic oil discharged from the oil pump 45 in a reference state. Here, as shown in FIG. 13, the reference discharge flow rate OD2a in the half-discharge mode is calculated based on, for example, the engine speed and the line pressure. The reference discharge flow rate OD2a is set to decrease as the engine speed decreases, and is set to increase as the engine speed increases. Furthermore, the reference discharge flow rate OD2a is set to increase as the line pressure decreases, and is set to decrease as the line pressure increases.

[0050] As shown in Fig. 10, in step S22, the reference discharge flow rate OD2a is multiplied by the aforementioned pump coefficient kp to calculate the oil discharge flow rate OD2 that can be discharged from the oil pump 45 operating in the half-discharge mode. Here, as shown in Fig. 8, the pump coefficient kp is set to be smaller as the oil discharge flow rate of the oil pump 45 decreases with the progression of deterioration over time. For this reason, if the oil pump 45 is deteriorating over time, the oil discharge flow rate OD2 calculated in step S22 is smaller, whereas if the oil pump 45 is not deteriorating over time, the oil discharge flow rate OD2 calculated in step S22 is larger.

[0051] Once the oil discharge flow rate OD2 is calculated in step S22 in this way, the process proceeds to step S23, where it is determined whether the oil discharge flow rate OD2 exceeds the oil consumption flow rate OC. If it is determined in step S23 that the oil discharge flow rate OD2 exceeds the oil consumption flow rate OC, an oil shortage that would accompany the execution of the half-discharge mode will not occur, and so the process proceeds to step S24, where the half-discharge mode of the oil pump 45 is executed. On the other hand, if it is determined in step S23 that the oil discharge flow rate OD2 is equal to or less than the oil consumption flow rate OC, there is a risk of an oil shortage that would accompany the execution of the half-discharge mode, and so the process proceeds to step S25, where the full-discharge mode of the oil pump 45 is executed.

[0052] [Mode switching control (timing chart)] The execution status of the above-mentioned mode switching control will be explained with reference to a timing chart. Fig. 14 is a timing chart showing an example of the execution status of the mode switching control. The timing chart of Fig. 14 shows a status where the continuously variable transmission mechanism 22 is upshifted from second speed to third speed.

[0053] The driving situation shown at time t1b in FIG. 14 is a situation in which the vehicle 11 is driving steadily with the continuously variable transmission mechanism 22 controlled to second speed (symbol a1). In this case, the oil discharge flow rate OD2 in half-discharge mode exceeds the oil consumption flow rate OC (symbol b1), and therefore the operation mode of the oil pump 45 is controlled to half-discharge mode (symbol c1). Subsequently, as shown at time t2b, when the target gear ratio of the continuously variable transmission mechanism 22 switches from second speed to third speed (symbol d1), the oil consumption flow rate OC increases with the upshift. Then, because the oil consumption flow rate OC exceeds the oil discharge flow rate OD2 (symbol b2), the operation mode of the oil pump 45 is controlled to full-discharge mode (symbol c2).

[0054] Here, as shown by the arrow α in FIG. 14 , when the pump coefficient kp is set large, the oil discharge flow rate OD2 increases, whereas when the pump coefficient kp is set small, the oil discharge flow rate OD2 decreases, as shown by the arrow β. In other words, when the oil discharge flow rate of the oil pump 45 decreases due to aging, the oil discharge flow rate OD2, which is the determination threshold, can be reduced to match this aging. In this way, the oil discharge flow rate OD2, which is the determination threshold used to determine the operation mode of the oil pump 45, can be appropriately increased or decreased in accordance with the aging of the oil pump 45. This allows the feasible range of the half-discharge mode to be expanded without causing an oil shortage in the transmission 13. Furthermore, expanding the feasible range of the half-discharge mode reduces the engine load and improves the fuel economy of the vehicle 11.

[0055] [Oil pump discharge performance] As described above, even if the oil discharge flow rate of the oil pump 45 decreases due to deterioration over time, this decreasing oil discharge flow rate can be appropriately determined. This makes it possible to avoid oil shortages in the transmission 13 without excessively increasing the discharge performance of the oil pump 45. FIG. 15 is a diagram showing the relationship between the oil discharge flow rate OD and the oil consumption flow rate OC. The oil discharge flow rate OD shown in FIG. 15 is the flow rate of oil discharged from the oil pump 45, and the oil consumption flow rate OC shown in FIG. 15 is the flow rate of oil consumed by the powertrain 14.

[0056] As shown in FIG. 15 as a comparative example, when it is not possible to determine the oil discharge flow rate OD actually discharged from the oil pump 45, it is necessary to design the oil pump 45 with improved discharge performance so as to prevent oil shortages by taking into account aging deterioration and individual component differences. That is, an expected maximum oil consumption flow rate X1 is calculated by adding an increase margin Aa1 due to individual component differences and an increase margin Aa2 due to component deterioration to the oil consumption flow rate OC of the transmission 13. Then, the oil discharge flow rate X2 of the oil pump 45 is set so as to satisfy the oil consumption flow rate X1 even if aging deterioration or individual component differences occur in the oil pump 45. That is, the oil discharge flow rate X2 is set as the required performance for the oil pump 45 so that an oil discharge flow rate OD exceeding the oil consumption flow rate X1 can be obtained even if the decrease margin Aa1 due to individual pump differences and the decrease margin Aa2 due to pump deterioration are reduced from the oil discharge flow rate X2 of the oil pump 45.

[0057] In contrast, as shown in the example, when it is possible to determine the oil discharge flow rate OD actually discharged from the oil pump 45, the current oil discharge flow rate OD can be grasped, and the oil consumption flow rate OC can be adjusted so that it does not exceed the oil discharge flow rate OD (arrow Xa). For example, when there is a risk that the oil discharge flow rate OD will be temporarily insufficient, the oil consumption flow rate OC can be adjusted so that it does not exceed the oil discharge flow rate OD by delaying the operation timing of a clutch or other device that consumes hydraulic oil. Furthermore, when it is possible to determine the oil discharge flow rate OD actually discharged from the oil pump 45, the current oil discharge flow rate OD can be grasped, and the oil discharge flow rate OD can be adjusted so that it does not fall below the oil consumption flow rate OC (arrow Xb). For example, when there is a risk that the oil discharge flow rate OD will be temporarily insufficient, the engine speed can be increased to temporarily increase the oil discharge flow rate OD, and the oil discharge flow rate OD can be adjusted so that it does not fall below the oil consumption flow rate OC.

[0058] In this way, since it is possible to appropriately grasp the oil discharge flow rate OD, which changes due to aging, it is possible to control the engine 12 and the transmission 13 so that the oil discharge flow rate OD exceeds the oil consumption flow rate OC. As a result, when designing the discharge capacity of the oil pump 45, it is not necessary to take into account the various margins Aa1, Aa2, Ab1, and Ab2, and it is possible to design the oil pump 45 with a lower discharge performance, as shown by the white arrows in Figure 15. This makes it possible to reduce the size and cost of the oil pump 45, and also to reduce the engine load and improve the fuel economy of the vehicle 11.

[0059] [Other embodiments] In the example shown in FIGS. 7 and 8 , the pump coefficient kp of the oil pump 45, i.e., the oil discharge flow rate, is determined based on the engagement time TC of the forward clutch 51, which is a hydraulic device. However, this is not limiting, and other hydraulic devices may be used. For example, the reverse clutch 53 provided in the forward / reverse switching mechanism 21 may be used as the hydraulic device. In this case, the oil discharge flow rate of the oil pump 45 can be determined based on the elapsed time from when the selector lever 108 is operated to the "R range" until the reverse brake is switched to the engaged state (target state). Note that when the reverse clutch 53 is used as the hydraulic device, the clutch oil chamber 75 of the reverse clutch 53 functions as a hydraulic oil chamber. Furthermore, the primary pulley 81 and the secondary pulley 83 provided in the continuously variable transmission mechanism 22 may be used as hydraulic devices. In this case, the oil discharge flow rate of the oil pump 45 can be determined based on the elapsed time from when the target speed ratio is switched until the continuously variable transmission mechanism 22 is controlled to the target speed change state (target state). When the primary pulley 81 and the secondary pulley 83 are used as hydraulic devices, the primary oil chamber 85 and the secondary oil chamber 86 function as hydraulic oil chambers.

[0060] 7 and 8, whether the forward clutch 51 has been switched to the engaged state is determined by comparing the turbine rotation speed Nt with the threshold value N1, but the present invention is not limited to this. For example, whether the forward clutch 51 has been switched from the released state to the engaged state may be determined based on the rate at which the turbine rotation speed Nt decreases, that is, the deceleration (negative acceleration) of the rotating turbine shaft 42. In this case, if the rate at which the turbine rotation speed Nt decreases exceeds a predetermined threshold value, it is determined that the forward clutch 51 has been switched from the released state to the engaged state.

[0061] In the above description, the oil pump 45 is configured with a half-discharge mode and a full-discharge mode as its operating modes. However, this is not limited thereto, and an oil pump 45 driven in only one operating mode may be used. Even in this case, the oil discharge flow rate of the oil pump 45, which changes due to aging, can be grasped, and the powertrain 14 can be controlled so that the oil discharge flow rate exceeds the oil consumption flow rate. This not only reduces the size and cost of the oil pump 45, but also reduces the engine load and improves the fuel economy of the vehicle 11. While the illustrated oil pump 45 is a vane pump, this is not limited thereto, and it goes without saying that a trochoid pump, a gear pump, or the like may also be used. Furthermore, while the illustrated oil pump 45 is an oil pump driven by the engine 12, this is not limited thereto, and the oil pump 45 may also be an oil pump driven by an electric motor.

[0062] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present invention. In the above description, the control system 95 is configured by a plurality of control units 36, 93, and 96, but this is not limiting. For example, the control system 95 may be configured by a single control unit. In addition, in the illustrated example, the continuously variable transmission mechanism 22 is incorporated into the transmission 13, but this is not limiting. For example, the transmission 13 may be incorporated with an automatic transmission mechanism consisting of a planetary gear train. [Explanation of symbols]

[0063] 10 Vehicle control device 11 vehicles 12 Engine (power source) 18 wheels 23 Power transmission path 45 Oil pump 51 Forward clutch (hydraulic device) 53 Reverse clutch (hydraulic device) 65 Clutch oil chamber (hydraulic oil chamber) 75 Clutch oil chamber (hydraulic oil chamber) 81 Primary pulley (hydraulic device) 83 Secondary pulley (hydraulic device) 85 Primary oil chamber (hydraulic oil chamber) 86 Secondary oil chamber (hydraulic oil chamber) 95 Control Systems 110 processors 111 memory 132 Clutch pressure control valve (control valve) 134 Switch valve (control valve) 160 Oil road Nt Turbine rotation speed N1 threshold TC engagement time (elapsed time) OD, OD2 oil discharge flow rate

Claims

1. A vehicle control device provided in a vehicle, a hydraulic device provided in a power transmission path connecting the power source and the wheels; an oil pump connected to a hydraulic oil chamber of the hydraulic device and supplying oil to the hydraulic oil chamber; a control valve provided in an oil passage connecting the oil pump and the hydraulic oil chamber, for controlling oil supply to the hydraulic oil chamber; a control system including a processor and a memory communicatively connected to each other, the control system controlling the hydraulic device via the control valve; and the control system determines the oil discharge flow rate of the oil pump based on the elapsed time from when the control valve is controlled to start supplying oil to the hydraulic oil chamber until the operating state of the hydraulic device reaches a target state; The control system determines that the oil discharge flow rate of the oil pump is smaller as the elapsed time is longer. Vehicle control device.

2. 2. The vehicle control device according to claim 1, the hydraulic device is a clutch provided in a forward / reverse switching mechanism, the control system determines the oil discharge flow rate of the oil pump based on the elapsed time from when the control valve is controlled to start supplying oil to the hydraulic oil chamber until the clutch is switched from a released state to an engaged state. Vehicle control device.

3. 3. The vehicle control device according to claim 2, the control system determines the oil discharge flow rate of the oil pump based on the elapsed time when a driving range is selected for the first time and the clutch is switched to an engaged state after the oil pump is driven after its stop period has exceeded a predetermined period; Vehicle control device.

4. 4. The vehicle control device according to claim 3, a torque converter provided between the power source and the forward / reverse switching mechanism; The control system determines that the clutch is switched to an engaged state when the turbine rotation speed of the torque converter falls below a threshold value or when the rate of decrease in the turbine rotation speed of the torque converter exceeds a threshold value. Vehicle control device.

Images