JP5240219B2 - Hydraulic control device for vehicle - Google Patents

Description

  The present invention relates to a hydraulic control apparatus for a vehicle that can selectively supply oil discharged from a high-pressure hydraulic source or a low-pressure hydraulic source to a hydraulic chamber that controls a torque capacity of a vehicle power transmission device.

  A high pressure hydraulic source and a low pressure hydraulic source are provided to supply oil to a hydraulic chamber that controls the torque capacity of the vehicle power transmission device, and the oil discharged from the high pressure hydraulic source or the low pressure hydraulic source is selectively selected. An example of a hydraulic control device configured to be supplied is described in Patent Document 1. The vehicle described in Patent Document 1 is configured such that engine torque is transmitted to an automatic transmission. The automatic transmission includes a torque converter, a clutch, and a transmission arranged in series so that power can be transmitted. Configured. In addition to a mechanical pump driven by an engine, an electric oil pump driven by electric power is provided as a hydraulic pressure source that generates hydraulic pressure for engaging the clutch. The battery that drives the electric oil pump is configured to supply power to a starter that starts the engine. In the vehicle hydraulic control device described in Patent Document 1, the pressure oil discharged from the mechanical pump or the electric oil pump can be selectively switched and supplied to the clutch for engagement.

  On the other hand, in the vehicle described in Patent Document 1, when the drive position of the automatic transmission is selected, the engine can be stopped regardless of the operation of the ignition key, and thereafter, the engine can be stopped regardless of the operation of the ignition key. When the engine is restarted, control is performed in which the electric oil pump is driven in advance to engage the clutch. Thereafter, when the engine is restarted, control for engaging the clutch is performed in consideration of the change in the voltage or hydraulic pressure value of the battery that drives the electric oil pump. Specifically, when engine start control is performed while the clutch is in the engaged state, clutch re-engagement control is performed after the engine is started.

  In addition, in order to supply oil to the pressure oil required part, an oil pump driven by the engine and an electric oil pump are provided, and the oil discharged from the electric oil pump is discharged when the engine is stopped. In addition to Patent Document 1, Patent Documents 2 and 3 describe a vehicle hydraulic control apparatus capable of performing control to supply pressure oil to a required part.

JP 2006-138426 A JP 2003-39988 A JP 2000-046166 A

  Discharge pressures differ between the two types of hydraulic power sources described in Patent Documents 1 to 3, that is, the oil pump driven by the engine and the electric oil pump. For this reason, when the engine is stopped, the oil discharged from the electric oil pump is supplied in advance to the pressure oil required portion, and then, when starting the engine, the oil pump driven by the engine is used. If the control is performed to supply the discharged oil to the pressure oil required portion, the hydraulic pressure of the pressure oil required portion may change abruptly. However, this point is considered in any of Patent Documents 1 to 3. There was room for improvement.

  The present invention has been made paying attention to the technical problem described above, and when the oil supplied to the pressure oil required portion is changed from the oil discharged from the low pressure hydraulic source to the oil discharged from the high pressure hydraulic source. Another object of the present invention is to provide a vehicular hydraulic control device capable of suppressing a rapid increase in the hydraulic pressure of the pressure oil required portion.

  In order to achieve the above object, a first aspect of the present invention is a friction engagement device that is provided in a power transmission path from an engine to a drive wheel and whose torque capacity is controlled by the hydraulic pressure of the first hydraulic chamber; A friction type continuously variable transmission which is arranged in series with the friction engagement device in the power transmission path and whose torque capacity is controlled by the hydraulic pressure of the second hydraulic chamber, and the first hydraulic pressure driven by the power source A high-pressure hydraulic source that discharges oil supplied to the chamber and the second hydraulic chamber, and a low-pressure hydraulic source that is driven by an electric motor to discharge oil supplied to the first hydraulic chamber and the second hydraulic chamber, In the vehicle hydraulic control apparatus configured to supply oil discharged from the low pressure hydraulic source to the first hydraulic chamber and the second hydraulic chamber when the engine is stopped, the high pressure hydraulic source Said A first path that is provided in a path to the hydraulic chamber, regulates the discharge hydraulic pressure of the high-pressure hydraulic source and supplies the pressure to the first hydraulic chamber, and is provided in parallel with the first path, and the high-pressure hydraulic pressure A second path for supplying the discharge hydraulic pressure of the source to the first hydraulic chamber without adjusting the pressure, an operating state for connecting the first path and the first hydraulic chamber, the second path and the first hydraulic pressure. A switching valve capable of switching between an operation state for connecting the chamber and the engine, and the engine is rotated and the high pressure hydraulic power source is stopped from the time when the engine is stopped and oil is discharged from the high pressure hydraulic power source. Until the torque capacity of the friction engagement device reaches a predetermined value, the switching valve is controlled by the discharge pressure of the low-pressure hydraulic source, and the first path and the first hydraulic chamber are connected. Switch oil passages that maintain a connected operating state. Some characterized.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the friction type continuously variable transmission is a belt-type continuously variable transmission configured by winding a belt around a primary pulley and a secondary pulley. The vehicle hydraulic control apparatus is configured such that the torque capacity is adjusted by controlling the clamping pressure applied to the belt from the secondary pulley by the hydraulic pressure of the two hydraulic chambers.

  According to the first aspect of the present invention, when the engine is rotated and the high pressure hydraulic source discharges a relatively high hydraulic pressure from the state where the engine is stopped and the high pressure hydraulic source is stopped, the discharge pressure of the high pressure hydraulic source is Can be regulated and supplied to the first hydraulic chamber. Therefore, when the high pressure hydraulic power source begins to discharge the hydraulic pressure, it is possible to prevent the torque capacity of the friction engagement device from rapidly increasing, and the friction type continuously variable transmission arranged in series with the friction engagement device Slip can be suppressed.

  According to the invention of claim 2, in addition to obtaining the same effect as that of the invention of claim 1, the belt slides at the continuously variable transmission at the stage where the engine is rotated and pressure oil starts to be discharged from the high pressure hydraulic power source. This can be suppressed.

It is a schematic diagram which shows the specific example of the hydraulic control apparatus in this invention. It is a mimetic diagram showing composition of vehicles which have a hydraulic control device of the present invention. It is a time chart which shows an example of an effect | action of the hydraulic control apparatus shown by FIG. It is a diagram which shows an example of the characteristic of the hydraulic control apparatus shown by FIG. It is a time chart which shows the effect | action of the comparative example of the hydraulic control apparatus shown by FIG. It is a schematic diagram which shows the other specific example of the hydraulic control apparatus in this invention. It is sectional drawing which shows the structure of the electromagnetic pump used for the hydraulic control apparatus of FIG. It is a time chart which shows an example of an effect | action of the hydraulic control apparatus shown by FIG. It is a diagram which shows an example of the characteristic of the hydraulic control apparatus shown by FIG.

  Next, the hydraulic control device according to the present invention will be described with reference to the drawings. FIG. 2 is a schematic diagram showing a configuration of a vehicle having the hydraulic control device of the present invention. The vehicle 1 shown in FIG. 2 has an engine 2 as a power source that generates power to be transmitted to the drive wheels. The engine 2 is a power unit that converts thermal energy generated when fuel is burned into kinetic energy. As the engine 2, an internal combustion engine such as a gasoline engine, a diesel engine, an LPG engine, or the like can be used. In addition, a starter motor (not shown) is provided for cranking the stopped engine 2 before supplying fuel to the engine 2. A continuously variable transmission 3 is provided on the power transmission path from the engine 2 to the drive wheels. The continuously variable transmission 3 is a power transmission device capable of changing the ratio of the input rotation speed and the output rotation speed in a stepless manner. In this specific example, the continuously variable transmission 3 includes a primary pulley 4 and a secondary pulley. 5 is a belt type continuously variable transmission in which a belt 6 is wound around. A hydraulic chamber 7 for controlling the winding radius of the belt 6 in the primary pulley 4 is provided, and a hydraulic chamber 8 for controlling the clamping pressure applied from the secondary pulley 5 to the belt 6 is provided. The gear ratio of the continuously variable transmission 3 is controlled by controlling the amount of oil in the hydraulic chamber 7, while the torque capacity of the continuously variable transmission 3 is controlled by controlling the hydraulic pressure in the hydraulic chamber 8. The

  On the other hand, a clutch C1 is provided in the power transmission path from the engine 2 to the continuously variable transmission 5. The clutch C1 controls the capacity of torque transmitted between the engine 2 and the continuously variable transmission 5, and in this specific example, a hydraulically controlled clutch is used as the clutch C1. The clutch C1 may be a multi-plate clutch, a single plate clutch, a dry clutch, or a wet clutch. A hydraulic chamber 8 acting on the clutch C1 is provided, and the clutch C1 is engaged and released by controlling the hydraulic pressure of the hydraulic chamber 8.

  Next, a specific example of a hydraulic control device that controls the gear ratio and torque capacity of the continuously variable transmission 3 and the engagement and release of the clutch C1 will be described with reference to FIG. The hydraulic control apparatus 10 shown in FIG. 1 is provided with a mechanical oil pump 11 (hereinafter referred to as an oil pump 11) driven by the engine 2, and the oil pump 11 sucks oil from an oil pan 12. In addition, the pressure oil is discharged from the discharge port 13 to the oil passage 14. The oil pump 11 may be any of a gear pump, a vane pump, and a plunger pump, and is connected to the crankshaft of the engine 2 so that power can be transmitted. An oil passage 16 is provided in the oil passage 14 with a switching valve 15 interposed.

  The switching valve 15 includes an input port 17 and an output port 18 that are connected or disconnected by a spool (not shown), and a spring 19 that generates a force that presses the spool so that the input port 17 and the output port 18 are connected. A switching port 20 that generates a force for pressing the spool so that the input port 17 and the output port 18 are connected, and a switching port 21 that generates a force for pressing the spool so as to shut off the input port 17 and the output port 18. And have. The input port 17 is connected to the oil passage 14, the output port 18 is connected to the oil passage 16, the switching port 20 is connected to the oil passage 14, and the switching port 21 is connected to the oil passage 26.

  On the other hand, in addition to the oil pump 11, an electric oil pump 24 driven by an electric motor 23 is provided. The discharge capacity of the electric oil pump 24 is less than the discharge capacity of the oil pump 11, and the discharge pressure of the oil pump 11 is higher than the discharge pressure of the electric oil pump 24. A check valve 27 is provided between the oil passage 26 to which the pressure oil discharged from the discharge port 25 of the electric oil pump 24 is supplied and the discharge port 25 of the electric oil pump 24. The check valve 27 is configured to be opened in a direction in which oil discharged from the electric oil pump 24 is supplied to the oil passage 26 and closed in a direction in which oil in the oil passage 26 returns to the electric oil pump 24. . Further, the oil passage 26 is connected to the switching port 21 of the switching valve 15. The oil passage 16 is connected to the oil passage 26 with a relief valve 80 interposed therebetween. The relief valve 80 is configured to be opened in a direction in which oil in the oil passage 26 is supplied to the oil passage 16 and closed in a direction in which oil in the oil passage 16 returns to the oil passage 26.

  When the oil pump 11 is driven by the power of the engine 2 and pressure oil is discharged to the oil passage 14, the spool is moved by the hydraulic pressure of the switching port 20 and the force of the spring 19, and the input port 17 and the output port 18 is connected, and the pressure oil discharged from the oil pump 11 to the oil passage 14 is supplied to the oil passage 16 via the switching valve 15. On the other hand, when the engine 2 is stopped and the oil pump 11 is stopped, the electric oil pump 24 is driven to discharge the pressure oil to the oil passage 26, and the hydraulic pressure in the oil passage 26 becomes relatively high. The spool is moved against the force of the spring 19 by the hydraulic pressure of the port 21, and the input port 17 and the output port 18 are blocked. Furthermore, when the electric oil pump 24 is driven and the oil pressure of the oil passage 26 increases, the relief valve 80 is opened and oil is supplied from the oil passage 26 to the oil passage 16.

  Thus, by switching the switching valve 15, either the pressure oil discharged from the oil pump 11 or the pressure oil discharged from the electric oil pump 24 is supplied to the oil passage 16. A pressure control valve (line pressure modulator valve) 28 is provided in the oil supply path from the oil path 16 to the hydraulic chamber 8. The pressure control valve 28 includes a spool that can reciprocate in a linear direction, an input port 29, an output port 30, a drain port 31, a feedback port 32, a signal pressure port 33, and a spring 34 that presses the spool. Yes. The input port 29 is connected to the oil passage 16, and the output port 30 is connected to the hydraulic chamber 8 via the oil passage 35. The oil passage 35 is provided with a control valve (not shown) for selectively switching supply of pressure oil to the hydraulic chamber 8, discharge of pressure oil from the hydraulic chamber 8, and confinement of pressure oil to the hydraulic chamber 8. It has been. The feedback port 32 is connected to the output port 30, and the drain port 31 is connected to the oil pan 12. Further, a signal pressure Pslt that applies a force in the same direction as the force of the spring 34 to the spool is input to the signal pressure port 33.

  In the pressure control valve 28 configured as described above, the spool is pressed by the force of the spring 34 to connect the input port 29 and the output port 30, and the pressure oil in the oil passage 16 passes through the oil passage 35. While being supplied to the hydraulic chamber 8, the drain port 31 is shut off. When the oil pressure in the oil passage 35 is relatively low, the state where the input port 29 and the output port 30 are connected is continued. When the oil pressure in the oil passage 35 becomes relatively high, the spool is moved by the oil pressure in the feedback port 32, the input port 29 is closed, and the output port 30 and the drain port 31 are connected. Then, the oil in the oil passage 35 is discharged to the oil pan 12 via the drain port 31, and the oil pressure in the oil passage 35 is reduced. When the oil pressure in the oil passage 35 decreases, the spool moves due to the force of the spring 34 and the signal pressure Pslt of the signal pressure port 33, the input port 29 and the output port 30 are connected, and the drain port 31. Is closed. In this way, the oil pressure of the oil supplied to the hydraulic chamber 8 through the oil passage 16 is controlled by the pressure control valve 28. The signal pressure Pslt can be linearly controlled by a linear solenoid valve (not shown), and the pressure control valve 28 is oil supplied to the hydraulic chamber 8 as the signal pressure Pslt is relatively increased. It has a pressure regulation characteristic that makes the hydraulic pressure of the engine relatively high.

  Next, a configuration of a path for supplying the pressure oil discharged from the oil pump 11 to the hydraulic chamber 9 will be described. Oil passages 78 and 79 branched in two directions are connected to the oil passage 14. The oil passages 78 and 79 are arranged in parallel, and the oil passages 78 and 79 are connected to the switching valve 36. The switching valve 36 includes two input ports 38 and 39, an output port 40, a switching port 41, and a spring 42 that applies a force to the spool. The input port 38 is connected to the oil passage 78, the output port 40 is connected to the oil passage 37, and the switching port 41 is connected to the oil passage 26. The force generated by the hydraulic pressure of the switching port 41 is applied to the spool in the direction opposite to the force of the spring 42.

  Further, a pressure control valve (clutch control valve) 43 is provided in a path from the oil path 79 to the input port 39 of the switching valve 36. The pressure control valve 43 includes a spool that can reciprocate in a linear direction, an input port 44, an output port 45, a drain port 46, a feedback port 47, a signal pressure port 48, and a spring 49 that presses the spool. Yes. The input port 44 is connected to the oil passage 79, and the output port 45 is connected to the input port 39 via the oil passage 50. The feedback port 47 is connected to the output port 45, and the drain port 46 is connected to the oil pan 12. Further, a signal pressure Pslt that applies a force in the same direction as the force of the spring 49 to the spool is input to the signal pressure port 48. This signal pressure Pslt is the same pressure as the signal pressure Pslt acting on the pressure control valve 28.

  In the pressure control valve 43 configured in this way, the spool is pressed by the force of the spring 49 to connect the input port 44 and the output port 45, and the oil discharged from the oil pump 11 passes through the oil passage 79. While being output from the oil passage 50, the drain port 46 is closed. When the oil pressure in the oil passage 50 is relatively low, the state where the input port 44 and the output port 45 are connected is continued. When the oil pressure of the oil passage 50 becomes relatively high, the spool is moved by the oil pressure of the feedback port 47, the input port 44 is closed, and the output port 45 and the drain port 46 are connected. Then, the oil in the oil passage 50 is discharged to the oil pan 12 via the drain port 46, and the oil pressure in the oil passage 50 decreases. Thus, when the oil pressure of the oil passage 50 is reduced, the spool is moved by the force of the spring 49 and the signal pressure Pslt of the signal pressure port 48, the input port 44 and the output port 45 are connected, and The drain port 46 is closed. In this way, the oil pressure of the oil supplied from the oil pump 11 to the oil passage 50 is controlled by the pressure control valve 43. The signal pressure Pslt can be controlled linearly by a linear solenoid valve (not shown). The higher the signal pressure Pslt is, the higher the oil pressure in the oil passage 50 is.

  Further, a switching valve 51 is provided on the path from the switching valve 36 to the hydraulic chamber 9. The switching valve 51 includes two input ports 52 and 53, an output port 54, a drain port 55, two switching ports 56 and 57, and a spring 58 that applies a force in the same direction as the switching port 56 to the spool. Have. The input port 52 is connected to the oil passage 37, the input port 53 is connected to the oil passage 26, the switching port 56 is connected to the oil passage 37, the switching port 57 is connected to the oil passage 26, and the drain port 55 is An oil path 59 is connected to the oil pan 12 and the output port 54.

  In the switching valve 51 configured as described above, when the hydraulic pressure supplied to the oil passage 37 is relatively high, the spool is moved by the oil pressure of the oil passage 37 and the force of the spring 58, and the input port 52 and the output port 54 are connected, and the input port 53 and the drain port 55 are connected. Then, the oil discharged from the oil pump 11 is supplied to the oil passage 59, while the oil discharged from the electric oil pump 24 is discharged to the oil pan 12. On the other hand, when the oil pressure in the oil passage 37 is relatively low and the oil pressure in the oil passage 26 is relatively high, the spool moves and the input port 53 and the output port 54 are connected, and the input Port 52 is closed. Then, the oil discharged from the electric oil pump 24 is supplied to the oil passage 59.

  Further, a switching valve 60 is provided between the oil passage 59 and the hydraulic chamber 9. The switching valve 60 opens or closes a path for supplying oil to the hydraulic chamber 9 and has an input port 61 and an output port 62. The input port 61 is connected to the oil passage 59, and the output port 62 is connected to the hydraulic chamber 9 through the oil passage 63. The switching valve 60 is switched according to the shift position selected by the driver. Specifically, when the driver selects the drive position or the reverse position, the oil path 59 and the oil path 63 are connected by the switching valve 60. On the other hand, when the driver selects the neutral position or the parking position, the oil path 59 and the oil path 63 are blocked by the switching valve 60.

  Further, the control system of the vehicle 1 will be described with reference to FIG. 1. The vehicle speed, the operation state of the accelerator pedal, the operation state of the brake pedal, the input rotation speed and the output rotation speed of the continuously variable transmission 3, the hydraulic chambers 8 and 9 An electronic control device 64 to which a signal of a sensor or switch for detecting the hydraulic pressure, the engine speed, the selected shift position, the operation state of the ignition key, etc. is input is provided, and the engine output is controlled from the electronic control device 64. A signal for controlling the hydraulic control device 10 and the like.

  Explaining the control example of the vehicle 1 configured as described above, the required driving force (target driving force) in the vehicle 1 is obtained based on the vehicle speed and the accelerator opening, and the target engine output is based on the required driving force. Is required. Furthermore, when the actual engine output is controlled based on the target engine output, the target engine speed and the target engine output are determined so that the operating state of the engine 2 is along the optimum fuel consumption line. Then, the gear ratio of the continuously variable transmission 3 is controlled so that the actual engine speed approaches the target engine speed. In order to control the gear ratio of the continuously variable transmission 3, the amount of oil in the hydraulic chamber 7 is controlled. Further, the hydraulic pressure in the hydraulic chamber 8 is controlled in order to control the torque capacity of the continuously variable transmission 3. Furthermore, the torque capacity when the clutch C1 is engaged is controlled based on the transmission torque from the engine 2 to the continuously variable transmission 3.

  By the way, the vehicle 1 can be controlled to operate or stop the engine 2 based on the operation of the ignition key. In addition, when the engine 2 is operated, a stop condition different from the operation of the ignition key is established. In this case, it is possible to perform eco-run control for stopping the engine 2 without operating the ignition key. Further, when the engine 2 is stopped by the eco-run control and the stop condition is released, the engine 2 can be started without operating the ignition key. The above stop condition is satisfied when, for example, the drive (D) position is selected as the shift position, the vehicle 1 is stopped, the accelerator pedal is returned, and the brake pedal is depressed. When the engine 2 is stopped by the eco-run control, the following control is performed.

  First, the electric oil pump 24 is driven by the electric motor 23, and oil is discharged to the oil passage 26. When the hydraulic pressure of the switching port 57 rises and the spool of the switching valve 51 moves against the force of the spring 58, the input port 53 and the output port 54 are connected and the input port 52 is closed. For this reason, the oil discharged from the electric oil pump 24 is supplied to the oil passage 59 via the oil passage 26 and the switching valve 51. When the drive position is selected, the input port 61 and the output port 62 of the switching valve 60 are connected, so that the oil supplied from the electric oil pump 24 to the oil passage 59 passes through the oil passage 63. It is supplied to the hydraulic chamber 9 via. In this way, the hydraulic pressure in the hydraulic chamber 9 is maintained at a predetermined value. When the hydraulic pressure in the hydraulic chamber 9 is a predetermined value, the plate constituting the clutch C1 and the disk are kept close to each other.

  On the other hand, when oil is supplied from the electric oil pump 24 to the oil passage 26 and the oil pressure of the oil passage 26 becomes relatively high, the spool of the switching valve 15 moves against the force of the spring 19, and the input port 17. And the output port 18 are blocked. Further, when oil is supplied from the electric oil pump 24 to the oil passage 26 and the oil pressure of the oil passage 26 becomes relatively high, the relief valve 80 is opened and the oil discharged from the electric oil pump 24 is supplied to the oil passage 16. Is done. Here, in the pressure control valve 28, the spool is moved by the force of the spring 34, and the input port 29 and the output port 30 are connected. For this reason, the oil supplied from the electric oil pump 24 to the oil passage 16 is supplied to the oil passage 35 via the input port 29 and the output port 30, and then supplied to the hydraulic chamber 8.

  The oil pressure in the oil passage 35 increases, but when the oil pressure in the oil passage 35 is relatively low, the state where the input port 29 and the output port 30 are connected is continued. Thereafter, when the force applied to the spool by the hydraulic pressure of the feedback port 32 exceeds the force of the spring 34 and the signal pressure Pslt, the spool moves and the input port 29 is closed, and the output port 30 and the drain port 31 is connected. Then, the oil in the oil passage 35 is discharged to the oil pan 12 via the drain port 31, and the oil pressure in the oil passage 35 is reduced. When the oil pressure in the oil passage 35 is thus reduced, the spool is moved by the force of the spring 34 and the signal pressure Pslt of the signal pressure port 33, the input port 29 and the output port 30 are connected, and the drain port 31 is closed. When the engine 2 is not started, the signal pressure Pslt is controlled to be relatively low so that the torque capacity of the continuously variable transmission 3 is kept relatively low. As described above, the oil discharged from the electric oil pump 24 is regulated (depressurized) by the pressure control valve 28 and supplied to the hydraulic chamber 8. As described above, when the engine 2 is stopped by the eco-run control, the reason why the oil is supplied to the hydraulic chambers 8 and 9 in advance is that the condition for starting the engine 2 in the future is established and the torque of the clutch C1 is satisfied. This is to improve control response when performing control to increase the capacity and increase the torque capacity of the continuously variable transmission 3.

  On the other hand, when the condition for starting the engine 2 is satisfied when the engine 2 is stopped by the eco-run control, the engine 2 is cranked (rotated) by the starter motor, and the fuel is supplied and burned, so that the engine 2 is autonomously rotated, and control is performed to increase the torque capacity of the clutch C1 to a predetermined value. Then, the oil pump 11 is driven and oil is discharged to the oil passage 14.

  Then, when oil is discharged from the oil pump 11 and the oil pressure of the oil passage 14 is increased, and the force applied to the spool by the oil pressure of the switching port 20 and the spring 19 exceeds the force applied to the spool by the oil pressure of the switching port 21, the switching is performed. The spool of the valve 15 moves and the input port 17 and the output port 18 are connected. In this way, the oil discharged from the oil pump 11 is supplied to the oil passage 16. When the oil pressure of the oil passage 16 becomes relatively high due to the oil discharged from the oil pump 11, the relief valve 80 is closed, and the oil discharged from the electric oil pump 24 is not supplied to the oil passage 16. Therefore, the oil supplied from the oil pump 11 to the oil passage 16 is supplied to the hydraulic chamber 8 via the oil passage 35.

  Next, the operation of supplying the oil discharged from the oil pump 11 to the hydraulic chamber 9 will be described. The electric oil pump 24 is driven until the torque capacity of the clutch C1 is increased to a predetermined value after the control for cranking the engine 2 is started as described above. That is, the hydraulic pressure of the oil discharged from the electric oil pump 24 is supplied to the switching port 41 of the switching valve 36, the input port 39 and the output port 40 are connected, and the input port 38 is closed. . For this reason, the oil discharged from the oil pump 11 is supplied to the oil passage 37 via the pressure control valve 43 and the oil passage 50. Here, during cranking of the engine 2, the pressure control valve 43 performs hydraulic control based on the signal pressure Pslt. More specifically, when the hydraulic pressure supplied to the hydraulic chamber 9 via the pressure control valve 43 is equal to or lower than the target hydraulic pressure corresponding to the signal pressure Pslt, the spool is moved by the force of the spring 49 and the signal pressure Pslt. Thus, the state where the input port 44 and the output port 45 are connected is continued.

  When the hydraulic pressure in the hydraulic chamber 9 exceeds the target hydraulic pressure corresponding to the signal pressure Pslt, the spool is moved by the hydraulic pressure in the feedback port 47, the input port 44 is closed, and the output port 45 and the drain port 46 are connected. Connected. Then, the oil in the oil passage 50 is discharged to the oil pan 12 via the drain port 46, and the hydraulic pressure in the hydraulic chamber 9 decreases. When the hydraulic pressure in the hydraulic chamber 9 becomes equal to or lower than the target hydraulic pressure corresponding to the signal pressure Pslt, the spool is moved by the force of the spring 49 and the signal pressure Pslt of the signal pressure port 48, and the input port 44 and the output port 45 Are connected and the drain port 46 is closed. In this way, the oil pressure of the oil supplied from the oil pump 11 to the hydraulic chamber 9 is controlled by the pressure control valve 43.

  Further, when the torque capacity of the clutch C1 increases to a predetermined value, for example, when the engagement of the clutch C1 is completed, the electric oil pump 24 is stopped. Whether or not the engagement of the clutch C1 has been completed may be determined from the hydraulic pressure in the hydraulic chamber 9, or may be determined from an elapsed time after the cranking of the engine 2 is started. When the electric oil pump 24 is stopped, the hydraulic pressure acting on the switching port 41 of the switching valve 36 is reduced, the spool is moved by the force of the spring 42, the input port 38 and the output port 40 are connected, and The input port 39 is closed. Therefore, the hydraulic pressure of the oil discharged from the oil pump 11 is supplied to the hydraulic chamber 9 without being reduced by the pressure control valve 43.

  Next, an example of a time chart when the engine 2 is started when the engine 2 is stopped by the eco-run control and the engine 2 is started will be described with reference to FIG. First, before time t1, the brake pedal is depressed (brake state ON), the accelerator pedal is returned (accelerator state OFF), the engine 2 is stopped (engine state OFF), and the vehicle 1 stops. ing. That is, before the time t1, a condition for stopping the engine 2 by the eco-run control is established, and before the time t1, the electric oil pump 24 is driven by the discharge hydraulic pressure Peop.

  Then, when the brake pedal is returned (braking state OFF) at time t1, control for cranking the engine 2 is started. The oil pump 11 is driven by the cranking of the engine 2 and the oil pressure Pd of the oil discharged from the oil pump 11 to the oil passage 14 increases. The oil discharged from the oil pump 11 is supplied to the hydraulic chamber 9 via the pressure control valve 43, and the target value Pc1 of the hydraulic pressure supplied to the hydraulic chamber 9 is indicated by a broken line. Further, after time t2, the actual oil pressure Pc1 of the oil controlled by the pressure control valve 43 and supplied to the oil pressure chamber 9 and the target value thereof substantially coincide with each other, and the oil pressure Pc1 is indicated by a broken line. On the other hand, the engine speed Ne has increased since time t1.

  Further, after time t3, the oil pressure Pd of the oil passage 14 becomes substantially constant, and the target value of the oil pressure supplied to the hydraulic chamber 9 and the actual oil pressure Pc1 are also substantially constant. On the other hand, the engine speed Ne is substantially constant after time t3. When fuel is supplied to the engine 2 at time t4 and an initial explosion occurs, the hydraulic pressure Pd in the hydraulic chamber 8 rises, and the target value of the oil pressure supplied to the hydraulic chamber 9 and the actual hydraulic pressure Pc1 Is rising. Furthermore, the engine speed Ne increases after time t4. Thereafter, when the accelerator pedal is depressed at time t6 via time t5, the hydraulic pressure Pd in the hydraulic chamber 8 is controlled to be substantially constant by the pressure control valve 28, and the hydraulic pressure Pc1 in the hydraulic chamber 9 is controlled by the pressure control valve. 43 is controlled almost constant. Thus, the engagement of the clutch 9 is completed at time t6, the vehicle 1 starts and the vehicle speed increases. Note that the engine speed Ne is constant after the time t5.

  Here, the relationship between the hydraulic pressure pd supplied to the hydraulic chamber 8 and the hydraulic pressure Pc1 supplied to the hydraulic chamber 9 after cranking the engine 2 will be described with reference to FIG. In FIG. 4, the horizontal axis indicates the hydraulic pressure pd, and the vertical axis indicates the hydraulic pressure Pc1. The hydraulic pressure allowed in the hydraulic chamber 9 is indicated by a line segment A1, target values of the hydraulic pressure Pd and the hydraulic pressure Pc1 are indicated by a line segment B1, and the actual value of the hydraulic pressure Pc1 is indicated by a line segment D1. Here, “the hydraulic pressure allowed in the hydraulic chamber 9” is a hydraulic pressure corresponding to the torque capacity of the clutch C1 that can prevent the belt 6 from slipping. That is, if the hydraulic pressure Pc1 in the hydraulic chamber 9 is less than the line segment A1, the slippage of the belt 6 can be prevented when the engine torque is transmitted to the belt 6 via the clutch C1. The line segment A1 and the line segment B1 both have a characteristic that the oil pressure Pc1 increases as the oil pressure Pd increases. If the oil pressure pd is the same, the line segment B1 has a lower pressure than the line segment A1. .

  In the hydraulic control device 10 shown in FIG. 1, when the engine 2 is cranked, the oil discharged from the oil pump 11 is regulated by the pressure control valve 43 and supplied to the hydraulic chamber 9. As shown in FIG. 4, the actual value of the hydraulic pressure Pc1 is controlled to be substantially constant at a value less than the line segment A1 until the hydraulic pressure Pd rises to Pd1 after the cranking of the engine 2 is started. Can do. When the hydraulic pressure Pd increases to the hydraulic pressure Pd2, the actual value of the hydraulic pressure Pc1 matches the line segment B1.

  As described above, in the hydraulic control apparatus 10 shown in FIG. 1, the engine 2 is rotated and the hydraulic oil is discharged from the oil pump 11 from the time when the engine 2 is stopped and the oil pump 11 is stopped. In addition, until the torque capacity of the clutch C1 reaches a predetermined value, the oil discharged from the electric oil pump 24 is supplied to the switching port 41 of the switching valve 36, and the input port 39 of the switching valve 36 is supplied. And the output port 40 are connected to each other. Therefore, the torque capacity of the clutch C1 can be gradually increased by making the actual hydraulic pressure of the oil supplied to the hydraulic chamber 9 substantially coincide with the target value Pc1 while the engine 2 is being cranked. It is possible to prevent the belt 6 from slipping in the continuously variable transmission 3. In addition, since the discharge pressure of the electric oil pump 24 is applied to the switching port 41 that switches the operation state of the switching valve 36, a solenoid valve for inputting the signal pressure to the switching port 41 is not provided. Since it is good, the number of parts can be reduced.

  Here, the configuration and operation of a comparative example of the hydraulic control apparatus 10 shown in FIG. 1 will be described. In this comparative example, an electromagnetic valve (not shown) that outputs a signal pressure for switching the switching valve 36 is provided, and pressure oil discharged from an oil pump driven by the engine is supplied to the input side of the electromagnetic valve. It is comprised so that it may be. In this comparative example, since the signal pressure for switching the switching valve is not output from the solenoid valve while the engine is stopped, the signal pressure of the solenoid valve is relatively low when cranking the engine. The valve cannot be switched. Therefore, the hydraulic pressure of the oil pump driven by the engine is supplied to the hydraulic chamber without being regulated, and slippage occurs in the continuously variable transmission. This will be described with reference to the time chart of FIG.

  In the time chart of FIG. 5, before the time t1, the engine is stopped by the eco-run control, and the electric oil pump is driven. When the brake pedal is returned at time t2, cranking of the engine is started, the oil pump is driven, and the discharge pressure rises as shown by the solid line. Further, since the discharge pressure of the oil pump driven by the engine is supplied to the hydraulic chamber without being regulated, the actual hydraulic pressure Pc1 of the hydraulic chamber becomes higher than the target value. That is, the hydraulic pressure Pc1 is the same as the hydraulic pressure Pd supplied to the hydraulic chamber of the continuously variable transmission from time t1 to time t2.

  Then, when the signal pressure is output from the electromagnetic valve at time t2 and the switching valve is switched, the hydraulic pressure discharged from the oil pump driven by the engine can be regulated by the pressure control valve. The actual oil pressure Pc1 decreases, and after time t3, the actual oil pressure Pc1 matches the target value. Then, fuel is supplied to the engine at time t4 and an initial explosion occurs, and the engine rotates autonomously after time t5. Further, the electric oil pump is stopped at time t6. As described above, in the time chart of FIG. 5, the actual hydraulic pressure Pc1 exceeds the target value from time t1 to time t3, and slippage may occur in the continuously variable transmission.

  Next, another specific example of the hydraulic control apparatus 10 shown in FIG. 2 will be described with reference to FIG. In FIG. 6, the same components as those in FIG. 1 are denoted by the same reference numerals as those in FIG. Comparing the hydraulic control device 10 shown in FIG. 1 with the hydraulic control device 10 shown in FIG. 6, the configuration of the low-pressure hydraulic source is different. In the hydraulic control apparatus 10 of FIG. 6, an electromagnetic pump 65 is provided as a low pressure hydraulic source. A specific configuration example of the electromagnetic pump 65 will be described with reference to FIG. The electromagnetic pump 65 is provided in a casing 66, and an electromagnetic coil 67 that forms a magnetic attraction force when a voltage is applied thereto, a plunger (piston) 68 provided in the casing 66 so as to be reciprocally movable, and a plunger A spring 69 that generates a force that moves 68 in a direction opposite to the magnetic attractive force, an oil chamber 70 formed in the casing 66, and a check valve 71 that regulates the direction of oil flow through the oil chamber 70 in one direction. , 72. The plunger 68 is made of a magnetic material, and is disposed in the casing 66 so as to reciprocate in the direction along the central axis thereof. The end of the plunger 68 in the direction along the central axis is disposed in the oil chamber 68. The voltage applied to the electromagnetic coil 67 is configured to be controlled by the electronic control unit 64.

  The check valve 71 has a valve body (ball) 74 that opens and closes a suction port 73 communicating with the oil chamber 70, and the suction port 73 is connected to the oil pan 12 via an oil passage 75. The plunger 68 is pressed against the valve element 74 by the force of the spring 69. The check valve 71 is opened when the oil in the oil pan 12 is sucked into the oil chamber 70 through the suction port 73, while the oil in the oil chamber 70 passes through the suction port 73 to the oil passage 75. It is configured to be closed in the outflow direction. On the other hand, the check valve 72 has a valve body (ball) 76 that opens and closes the discharge port 77 communicating with the oil chamber 70, and the discharge port 77 is connected to the oil passage 26. The check valve 72 is opened when the oil in the oil chamber 70 is discharged to the oil passage 26 via the discharge port 77, and is closed when the oil in the oil passage 26 returns to the oil chamber 70. It is configured. The oil pressure in the oil passage 75 is configured to act on the plunger 66 in the same direction as the spring 69.

  In the electromagnetic pump 65 configured as described above, when a voltage is applied to the electromagnetic coil 67, a magnetic attractive force is generated, the plunger 68 moves in a predetermined direction against the force of the spring 69, and the voltage is cut off. Then, the plunger 68 moves in the reverse direction by the force of the spring 69. Accordingly, the plunger 68 reciprocates in the casing 66 by alternately applying and interrupting the voltage to the electromagnetic coil 67. By the reciprocation of the plunger 68, the volume of the oil chamber 70 is expanded and reduced.

  Specifically, when the plunger 68 moves downward in FIG. 7 and the volume of the oil chamber 70 is increased, the oil chamber 70 becomes negative pressure (hydraulic pressure decreases), and the check valve 71 is opened. The oil in the oil pan 12 is sucked into the oil chamber 70 and the check valve 72 is closed. In contrast, in the process in which the plunger 68 moves upward in FIG. 7 and the volume of the oil chamber 70 is reduced, the hydraulic pressure in the oil chamber 70 increases. Then, the check valve 71 is closed, the check valve 72 is opened, and the oil in the oil chamber 70 is discharged to the oil passage 26. Thus, in the electromagnetic pump 65, oil can be repeatedly sucked and discharged, and the electromagnetic pump 65 functions as a reciprocating volume pump.

  Further, a check valve 81 is provided in the oil passage 75. In addition, between the electromagnetic pump 65 and the check valve 81 in the oil passage 75 is connected to the oil passage 78 through an oil passage 82. The oil path 82 constitutes a path for supplying the oil discharged from the oil pump 11 to the suction port 73 of the electromagnetic pump 65. The check valve 81 has a valve body that opens and closes a port in the same manner as conventionally known, and the check valve 81 is opened and closed by a pressure difference. The operation of the check valve 81 will be described. The port is opened when the oil flows from the oil pan 12 toward the electromagnetic pump 65, while the port is closed when the oil flows from the electromagnetic pump 65 or the oil pump 11 to the oil pan 12. It is configured as follows.

  In the hydraulic control apparatus 10 shown in FIG. 6, when the electromagnetic pump 65 is driven when the engine 2 is stopped by the eco-run control, the check valve 81 is opened and the oil in the oil pan 12 flows through the oil path. Pressure oil sucked into the electromagnetic pump 65 through 75 and discharged from the electromagnetic pump 65 to the oil passage 26 is supplied to the hydraulic chambers 8 and 9 through the switching valve 51 and the switching valve 60. Further, when the engine 2 is stopped by the eco-run control and the condition for starting the engine 2 is satisfied, the engine 2 is cranked, and then the fuel is burned in the engine 2 so that the engine 2 rotates autonomously. At the same time, when the engagement of the clutch C1 is completed, the electromagnetic pump 65 is stopped. As described above, in the hydraulic control device 10 of FIG. 6 as well, the electromagnetic pump 11 is stopped until the engine 2 is cranked and autonomously rotates until the engagement of the clutch C1 is completed. The oil discharged from 65 can be supplied to the switching port 41 of the switching valve 36 to connect the input port 39 and the output port 40, and the input port 38 can be closed.

  For this reason, when the engine 2 is cranked and the oil discharged from the oil pump 11 is supplied to the hydraulic chamber 9, the hydraulic pressure supplied to the hydraulic chamber 9 is regulated by the pressure control valve 43 and gradually increased. Can do. Therefore, also in the hydraulic control apparatus 10 shown in FIG. 6, the pressure oil discharged from the oil pump 11 is supplied to the hydraulic chamber 9 from the state where the pressure oil discharged from the electromagnetic pump 65 is supplied to the hydraulic chamber 9. It is possible to prevent the belt 6 from slipping in the continuously variable transmission 3 during the process of changing to the supply state. In addition, since the discharge pressure of the electromagnetic pump 65 is applied to the switching port 41 that switches the operation state of the switching valve 36, it is not necessary to provide a dedicated solenoid valve for inputting the signal pressure to the switching port 41. Therefore, the number of parts can be reduced.

  Further, in the hydraulic control device 10 of FIG. 6, when oil discharge from the oil pump 11 is started while the electromagnetic pump 65 is being driven, the pressure oil discharged from the oil pump 11 is supplied to the oil passage 83. And is supplied to the electromagnetic pump 65 via the oil passage 75. The hydraulic pressure discharged from the oil pump 11 can be increased by the electromagnetic pump 65 and supplied to the hydraulic chamber 9. Therefore, the discharge pressure of the electromagnetic pump 65 can be relatively lowered. The other configurations and operational effects of the hydraulic control apparatus 10 of FIG. 6 are the same as those of the hydraulic control apparatus 10 of FIG.

  Further, the operation of the hydraulic control apparatus 10 shown in FIG. 6 will be described based on the time chart of FIG. In the time chart of FIG. 8, the accelerator pedal operation time, the brake pedal operation time, the cranking of the engine 2 and the fuel combustion time are the same as the time of FIG. Further, since the vehicle speed and the engine speed are the same as those in FIG. 3, the description and explanation are omitted in FIG. In the time chart shown in FIG. 8, the discharge hydraulic pressure Peop of the electromagnetic pump 65 acts on the hydraulic chamber 9 until time t1, but when the oil pump 11 is driven at time t1, A part of the oil discharged from the oil pump 11 is supplied to the electromagnetic pump 65 via the oil passage 14 and the oil passage 82, and the hydraulic pressure discharged from the oil pump 11 is increased by the electromagnetic pump 65 to the hydraulic chamber 9. Supplied. Therefore, after time t2, the hydraulic pressure discharged from the oil pump 11 is increased by the amount Psm that is increased by the electromagnetic pump 65, and is higher than the hydraulic pressure Peop before time t1. Further, when the engagement of the clutch C1 is completed at time t6, the electromagnetic pump 65 is stopped. The other changes over time of the hydraulic pressure are the same as in FIG.

  Further, an example of a characteristic diagram of the hydraulic control device 10 shown in FIG. 6 will be described with reference to FIG. The meanings of the line segments A1, B1, and D1 are the same as those in FIG. In FIG. 9, when the hydraulic pressure increases below the hydraulic pressure Pd1, the actual value of the hydraulic pressure Pc1 increases. The reason is that the electromagnetic pump 65 starts to drive the oil pump 11 as described above, and the hydraulic pressure of the oil discharged from the oil pump 11 is increased by the electromagnetic pump 65 and supplied to the hydraulic chamber 9. This is because that. In the above embodiment, in the eco-run control, when the reverse (R) position is selected as the shift position, the vehicle 1 is stopped, the accelerator pedal is returned, and the brake pedal is depressed, A stop condition may be satisfied.

  Here, the correspondence between the configuration described based on each specific example and the configuration of the present invention will be described. The hydraulic chamber 9 corresponds to the first hydraulic chamber of the present invention, and the clutch C1 is configured according to the present invention. The continuously variable transmission 3 corresponds to the friction engagement device, the friction type continuously variable transmission of the present invention, the oil pump 11 corresponds to the high-pressure hydraulic source of the present invention, and the electric oil pump 24 The oil passages 50 and 79 and the pressure control valve 43 correspond to the first route of the invention, the oil passage 78 corresponds to the second route of the invention, and the switching valve 36 corresponds to the low pressure hydraulic power source of the invention. The oil passage 26 corresponds to the switching oil passage of the present invention. Further, when the engagement of the clutch C1 is completed, the torque capacity becomes “a predetermined value”. Furthermore, the predetermined value that is determined in advance is specifically the lowest value at which the torque transmitted from the engine can be transmitted without slipping of the clutch C1.

  In addition, the friction engagement device according to the present invention may be used for a forward / reverse switching device having a function of switching the rotation direction of the primary pulley forward and backward with respect to the rotation direction of the crankshaft of the engine. The forward / reverse switching device includes, for example, a sun gear connected to a crankshaft so that power can be transmitted, a ring gear disposed coaxially with the sun gear, a first pinion gear meshed with the sun gear, and a ring gear. It can be constituted by a double pinion type planetary gear mechanism having a second pinion gear and a carrier that supports the first pinion gear and the second pinion gear so as to rotate and revolve. Further, a reverse brake for selectively fixing the ring gear and a forward clutch for selectively connecting and releasing the carrier and the sun gear are provided. Further, a hydraulic chamber for controlling the engagement and release of the forward clutch is provided, and a hydraulic chamber for controlling the engagement and release of the reverse brake is provided.

  When the drive position is selected, the forward clutch is engaged to connect the carrier and the sun gear, and the reverse brake is released, and the rotational direction of the crankshaft and the primary pulley is changed. It will be the same. On the other hand, when the reverse position is selected, control is performed to engage the reverse brake, fix the ring gear, and release the forward clutch, and the primary pulley rotates in reverse with respect to the crankshaft. . In a vehicle in which the above-described forward / reverse switching device is provided between the engine and the continuously variable transmission, the hydraulic chamber for controlling the engagement and release of the clutch or brake is shown in FIG. 1 or FIG. Alternatively, the oil may be supplied via the switching valve 60 of the hydraulic control device.

  Moreover, although a belt type continuously variable transmission is mentioned as a continuously variable transmission, the hydraulic control apparatus of FIG. 1 or FIG. 6 can also be used in a vehicle equipped with a toroidal continuously variable transmission. In this toroidal-type continuously variable transmission, the power roller is supported by a trunnion, and by controlling the hydraulic pressure in the hydraulic chamber, the tilt angle of the power roller is controlled and the gear ratio is controlled. Further, in the toroidal continuously variable transmission, a hydraulic chamber is provided for applying a clamping pressure in the direction along the rotation axis of the input disk and the output disk, and by controlling the hydraulic pressure supplied to the hydraulic chamber, Torque capacity is controlled. The hydraulic pressure in the hydraulic chamber that controls the torque capacity of the toroidal-type continuously variable transmission can be controlled by the pressure control valve 28 of the hydraulic control device shown in FIG. 1 or FIG. In the present invention, the discharge pressure of the high pressure hydraulic source is higher than the discharge pressure of the low pressure hydraulic source, the high pressure hydraulic source includes a mechanical oil pump, and the low pressure hydraulic source includes an electric oil pump and an electromagnetic pump.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Engine, 3 ... Continuously variable transmission, 4 ... Primary pulley, 5 ... Secondary pulley, 6 ... Belt, 8, 9 ... Hydraulic chamber, 11 ... Oil pump, 24 ... Electric oil pump, 26, 50 , 78, 79 ... oil passage, 36 ... switching valve, 43 ... pressure control valve, C1 ... clutch.

Claims (2)

A friction engagement device which is provided in a power transmission path from the engine to the drive wheel and whose torque capacity is controlled by the hydraulic pressure of the first hydraulic chamber; and is arranged in series with the friction engagement device in the power transmission path; In addition, a friction type continuously variable transmission whose torque capacity is controlled by the hydraulic pressure of the second hydraulic chamber, and a high pressure hydraulic pressure driven by the power source to discharge oil supplied to the first hydraulic chamber and the second hydraulic chamber. And a low-pressure hydraulic source that is driven by an electric motor to discharge oil supplied to the first hydraulic chamber and the second hydraulic chamber, and is discharged from the low-pressure hydraulic source when the engine is stopped. In the vehicle hydraulic control device configured to supply the oil to the first hydraulic chamber and the second hydraulic chamber,
A first path that is provided in a path from the high-pressure hydraulic source to the first hydraulic chamber and that regulates the discharge hydraulic pressure of the high-pressure hydraulic source and supplies the pressure to the first hydraulic chamber, and in parallel with the first path A second path for supplying the first hydraulic chamber without adjusting the discharge hydraulic pressure of the high-pressure hydraulic source, an operating state for connecting the first path and the first hydraulic chamber, A switching valve capable of switching between an operating state connecting the second path and the first hydraulic chamber, and from a point in time when the engine is stopped and the high pressure hydraulic power source is stopped, the engine rotates to The switching valve is controlled by the discharge pressure of the low-pressure hydraulic source until the torque capacity of the friction engagement device reaches a predetermined value after oil is discharged from the high-pressure hydraulic source, and the first path And the first hydraulic chamber maintained in an operating state connected to each other That the hydraulic control device for a vehicle, characterized in that it comprises a switching oil passage.   The friction-type continuously variable transmission is a belt-type continuously variable transmission configured by winding a belt around a primary pulley and a secondary pulley, and a pinch applied to the belt from the secondary pulley by the hydraulic pressure of the second hydraulic chamber. 2. The vehicular hydraulic control apparatus according to claim 1, wherein the torque capacity is adjusted by controlling the pressure.

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