Hydraulic control device and hydraulic control method

Abstract

To discharge an amount of lubricating oil suitable for an object to be operated.SOLUTION: The hydraulic control device 3 includes the pump 12 that supplies oil, the first flow path 16 that connects the pump 12 and the operation target 1 operated by the oil pressure of the oil and through which the oil flows from the pump 12 to the operation target 1, the proportional control valve 20 that is provided in the first flow path 16 and switches whether or not to direct the oil from the pump 12 to the operation target 1, and the second flow path 30 that is connected to the branch point J1 on the upstream side of the proportional control valve 20 in the first flow path 16. A second flow path (30) including a first branch flow path (31) branched downstream of a branch point (J1) and through which oil flows at a first flow rate and a second branch flow path (32) branched downstream of the branch point (J1) and through which oil flows at a second flow rate smaller than the first flow rate, a flow rate switching valve (40) provided in the second flow path (30) and configured to switch a flow path through which oil flows between the first branch flow path (31) and the second branch flow path (32), and a switching unit (522) configured to control the proportional valve (20) and the flow rate switching valve (40) to switch a flow path through which oil flows.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a hydraulic control device and a hydraulic control method. [Background technology]

[0002] The hydraulic control method of Patent Document 1 increases the hydraulic pressure and amount of lubricating oil by controlling a valve to adjust the discharge pressure of the lubricating oil discharged by the pump to a predetermined line pressure when the oil temperature of the lubricating oil exceeds a threshold value, thereby increasing the line pressure of the automatic transmission. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-149024 Summary of the Invention [Problem to be solved by the invention]

[0004] The amount of lubricating oil discharged by the pump is set to be greater than the required amount of oil to prevent the pump efficiency from decreasing as the lubricating oil temperature increases, which would otherwise cause the required amount to fall short.As a result, when the pump efficiency is not decreasing, the problem of consuming energy to circulate the excess amount of oil arises.

[0005] The present invention has been made in consideration of these points, and has as its object to discharge an amount of lubricating oil suitable for an operating object. [Means for solving the problem]

[0006] A hydraulic control device according to a first aspect of the present invention includes a pump that supplies oil, a first flow path that connects an operating object that is operated by the oil pressure of the oil to the pump and through which the oil flows from the pump to the operating object, a first control valve that is provided in the first flow path and switches whether or not the oil is directed from the pump to the operating object, a second flow path that is connected to a branch point on the first flow path upstream of the first control valve and that branches off downstream of the branch point and includes a first branch flow path through which the oil flows at a first flow rate and a second branch flow path through which the oil flows at a second flow rate that is less than the first flow rate, and The oil supply system includes a second control valve provided in the second flow path, which switches whether the oil is directed to the first branch flow path or the second branch flow path, and a switching unit which switches the flow path through which the oil flows by controlling the first control valve and the second control valve, and when operating the operating object that is not supplied with the oil, if the oil pressure upstream of the operating object in the first flow path is less than a hydraulic pressure threshold, the switching unit switches the second control valve to direct the oil that is being directed to the first branch flow path to the second branch flow path, and then switches the first control valve to direct the oil to the operating object.

[0007] The oil supply device may further include a third adjustment valve that is provided in a third branch flow path that branches off from downstream of the branch point in the second flow path and upstream of the first branch flow path and the second branch flow path, and that switches whether or not the oil flowing through the third branch flow path is directed to the second adjustment valve, and the switching unit may energize the third adjustment valve to direct the oil flowing through the third branch flow path to the second adjustment valve, and switch the second adjustment valve by the oil pressure of the oil to direct the oil that is directed to the first branch flow path to the second branch flow path.

[0008] When operating the operating object that is not receiving the supply of oil, if the oil pressure is equal to or greater than the oil pressure threshold, the switching unit may switch the first control valve so as to direct the oil to the operating object while directing the oil to the first branch flow path.

[0009] The oil pan may include an acquisition unit that acquires the oil temperature of the oil stored in the oil pan, and a memory unit that stores the oil pressure corresponding to the oil temperature of the oil, and the switching unit may identify the oil pressure corresponding to the oil temperature acquired by the acquisition unit by referring to the memory unit.

[0010] The oil temperature control system may include an acquisition unit that acquires the oil temperature of the oil stored in the oil pan, and a memory unit that stores a map indicating an application time for applying a voltage to the first adjustment valve corresponding to the oil temperature of the oil stored in the oil pan and a current to be passed to apply the voltage to the first adjustment valve, and the switching unit may refer to the memory unit to determine the application time and the current corresponding to the oil temperature acquired by the acquisition unit, and then pass the current to the first adjustment valve for the application time.

[0011] The oil pan may have an acquisition unit that acquires the oil temperature of the oil stored in the oil pan, and the switching unit may switch whether to direct the oil to the first branch flow path or the second branch flow path based on the oil temperature acquired by the acquisition unit after directing the oil to the operating object.

[0012] The switching unit may direct the oil to the first branch flow path when the oil temperature acquired by the acquisition unit is equal to or higher than an oil temperature threshold, and may direct the oil to the second branch flow path when the oil temperature is lower than the oil temperature threshold.

[0013] A hydraulic control method according to a second aspect of the present invention is executed by a processor, and when an operating object operated by oil pressure is operated from a state in which the operating object is not supplied with oil, the operating object is connected to a pump that supplies the oil, and if the oil pressure upstream of the operating object in a first flow path through which the oil flows from the pump to the operating object is less than a threshold value, the method includes a switching step of switching the oil that is being directed toward the first branch flow path to be directed toward the second branch flow path, between a first branch flow path branched downstream from a second flow path branched from the first flow path and through which the oil flows at a first flow rate, and a second branch flow path through which the oil flows at a second flow rate that is less than the first flow rate. [Effects of the Invention]

[0014] According to the present invention, it is possible to achieve the effect of discharging an amount of lubricating oil suitable for an operating object. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram showing an overview of a hydraulic control system S according to the present embodiment. [Figure 2] FIG. 2 is a diagram showing the configuration of a hydraulic control device 3. [Figure 3] FIG. 2 shows the proportional valve 20 switched to state 20b. [Figure 4] FIG. 4 is a diagram showing the flow rate switching valve 40 switched to a state 40b. [Figure 5] FIG. 4 is a diagram showing the flow rate switching valve 40 switched to state 40c. [Figure 6] FIG. 2 is a diagram showing the hydraulic control device 3 after the state of the proportional valve 20 has been switched. [Figure 7] 5 is a diagram showing the operation of the hydraulic control device 3 when the hydraulic pressure is equal to or higher than the hydraulic pressure threshold value. FIG. [Figure 8] 10 is a diagram showing an example of a rectangular wave map and a current flowing through a proportional valve 20. FIG. [Figure 9] 3 is a diagram showing an example of a processing sequence in the hydraulic control device 3. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] <Overview of Hydraulic Control System S> FIG. 1 is a diagram showing an overview of a hydraulic control system S according to this embodiment. The hydraulic control system S shown in FIG. 1 includes an actuation target 1, a control device 2, and a hydraulic control device 3. The hydraulic control system S is a system for controlling the hydraulic pressure of hydraulic equipment such as a transmission mounted on a vehicle. In this embodiment, as an example, the configuration and operation of the hydraulic control system S to control the hydraulic pressure of the transmission will be described.

[0017] The actuation object 1 is, for example, a wet clutch and a hydraulic shifter included in the transmission, and includes a hydraulic cylinder that moves a piston inside the cylinder by hydraulic pressure. The control device 2 includes a processor such as a CPU (Central Processing Unit) or an ECU (Electronic Control Unit), and is a device that controls a vehicle equipped with a transmission. The control device 2 determines whether or not to cause the transmission including the actuation object 1 to shift gears, and outputs gear shift determination information indicating the result of the determination to the hydraulic control device 3. The control device 2 determines whether or not to cause the transmission to shift gears based on, for example, at least one of the rotation speed of the drive source detected by a rotation speed sensor (not shown) provided in the vehicle, the vehicle speed, acceleration corresponding to the amount of depression of the accelerator pedal, and the operation of the vehicle driver.

[0018] The hydraulic control device 3 is a device that controls the hydraulic pressure of oil flowing to the operation target 1. Upon receiving shift determination information from the control device 2 indicating that a shift is to be made in the transmission including the operation target 1, the hydraulic control device 3 directs oil to the operation target 1 and adjusts the flow rate of the oil so that the oil pressure does not decrease. For example, the hydraulic control device 3 directs a predetermined discharge amount based on the oil temperature out of the discharge amount of a pump that discharges oil stored in an oil pan to the operation target 1.

[0019] The amount of oil discharged by the pump is set to be greater than the amount of oil required by the operating object 1. Therefore, even if the oil discharge efficiency decreases as the oil temperature rises, the pump can discharge oil so as to maintain a hydraulic pressure that does not reduce the operating speed of the operating object 1. However, if the oil discharge efficiency does not decrease, the pump will discharge an excessive amount of oil, resulting in excessive consumption of energy for discharging and cooling the oil.

[0020] Therefore, the hydraulic control device 3 adjusts the flow rate of oil directed to the actuated object 1 based on the hydraulic pressure of the oil directed to the actuated object 1 during the time that the actuated object 1 is operating to change gears in the transmission including the actuated object 1. By operating in this manner, the hydraulic control device 3 can maintain a hydraulic pressure that does not reduce the operating speed of the actuated object 1, even without the pump discharging an excessive amount of oil. Furthermore, by not discharging an excessive amount of oil from the pump, energy consumption can be reduced.

[0021] <Configuration of hydraulic control device 3> Fig. 2 is a diagram showing the configuration of the hydraulic control device 3. Fig. 2 shows the hydraulic control device 3 in a state in which the pump 12 is not supplying oil. The hydraulic control device 3 includes an oil pan 10, a temperature sensor 11, a pump 12, a filter 13, a drive source 14, a relief valve 15, a first flow path 16, a pressure sensor 17, a proportional valve 20, a second flow path 30, a first branch flow path 31, a second branch flow path 32, a cooler 33, a third branch flow path 34, a fourth branch flow path 35, a flow rate switching valve 40, a solenoid valve 45, and a control valve control unit 50. The proportional valve 20 includes a solenoid 21, the flow rate switching valve 40 includes a first actuator 41 and a second actuator 42, and the solenoid valve 45 includes a solenoid 46.

[0022] The oil pan 10 is a tank provided below the transmission that stores oil to be directed toward the operating object 1 of the transmission. The multiple oil pans 10 shown in FIG. 2 are the same oil pan 10. The temperature sensor 11 is a sensor that detects the temperature of the oil stored in the oil pan 10. The pump 12 is a pump that supplies a fixed volume of oil, and sucks the oil stored in the oil pan 10 through the filter 13 and discharges it into the first flow path 16. The filter 13 is a filter that removes sludge such as metal pieces contained in the oil stored in the oil pan 10 from the oil.

[0023] The drive source 14 is a power source for driving the vehicle, and is, for example, a motor or an engine. The drive source 14 is also used to drive the pump 12, and when the drive source 14 is activated, the pump 12 supplies oil. The relief valve 15 is a so-called "relief valve" that opens as the pressure of the oil discharged from the pump 12 increases. The first flow path 16 connects the pump 12 to the operating object 1, which is operated by the oil pressure, and is a flow path through which oil flows from the pump 12 to the operating object 1. The pressure sensor 17 is a sensor that detects the oil pressure of the oil flowing through the first flow path 16.

[0024] The proportional valve 20 is a first control valve that is provided in the first flow path 16 and switches whether or not oil is directed from the pump 12 to the actuation target 1. State 20a shown in FIG. 2 indicates a state in which the proportional valve 20 is closed so as not to direct oil from the pump 12 to the actuation target 1, and directs oil from the actuation target 1 to the oil pan 10. State 20b shown in FIG. 2 indicates a state in which the proportional valve 20 is open so as to direct oil from the pump 12 to the actuation target 1. The proportional valve 20 switches to state 20a when the control valve control unit 50 does not apply a voltage to the solenoid 21, and switches to state 20b when the control valve control unit 50 applies a voltage to the solenoid 21.

[0025] 3 is a diagram showing the proportional valve 20 switched to state 20b. The hydraulic control device 3 shown in FIG. 3 differs from the hydraulic control device 3 shown in FIG. 2 in that the control valve control unit 50 is applying a voltage to the solenoid 21 and that the state of the proportional valve 20 is state 20b, but is the same in other respects. As shown in FIG. 3, when the control valve control unit 50 is applying a voltage to the solenoid 21, the proportional valve 20 opens and directs oil from the first flow path 16 to the actuation target 1. During the time that the control valve control unit 50 is applying a voltage to the solenoid 21, the proportional valve 20 opens more widely the greater the current when the voltage is applied, and therefore the greater the current, the greater the amount of oil flowing to the actuation target 1.

[0026] Returning to FIG. 2 , the second flow path 30 is a flow path connected to a branch point J1 in the first flow path 16 on the upstream side of the proportional valve 20. The second flow path 30 includes a first branch flow path 31 and a second branch flow path 32, which branch off downstream of the branch point J1. Specifically, the second flow path 30 branches off at a flow switching valve 40 provided downstream of a branch point J2 in the second flow path 30, which is downstream of the branch point J1. The first branch flow path 31, through which oil flows at a first flow rate, and the second branch flow path 32, through which oil flows at a second flow rate that is smaller than the first flow rate, are branched off at a flow switching valve 40 provided downstream of a branch point J2 in the second flow path 30. A cooler 33 is provided in the first branch flow path 31 to cool the oil flowing through the first branch flow path 31, but no cooler 33 is provided in the second branch flow path 32.

[0027] The cooler 33 is a so-called "oil cooler" that cools the oil by exchanging heat between the oil and the wind (traveling wind) flowing from the front of the vehicle. The cooler 33 may be provided with a fan to promote the inflow of wind from the front of the vehicle.

[0028] The third branch flow path 34 connects a branch point J3, which is downstream of the branch point J1 and upstream of the branch point J2 in the second flow path 30, to the solenoid valve 45, and is a flow path through which oil flows from the second flow path 30 to the solenoid valve 45. The fourth branch flow path 35 connects the branch point J2 in the second flow path 30 to the first actuator 41 of the flow rate switching valve 40, and is a flow path through which oil flows from the second flow path 30 to the first actuator 41.

[0029] The flow rate switching valve 40 is a second adjustment valve that is provided in the second flow path 30 and switches whether the oil is directed to the first branch flow path 31 or the second branch flow path 32. A state 40a shown in FIG. 2 shows a state in which the flow rate switching valve 40 is closed so as to prevent the oil from being directed to the first branch flow path 31 or the second branch flow path 32. A state 40b shown in FIG. 2 shows a state in which the flow rate switching valve 40 is open so as to direct the oil flowing through the second flow path 30 to the first branch flow path 31. A state 40c shown in FIG. 2 shows a state in which the flow rate switching valve 40 is open so as to direct the oil flowing through the second flow path 30 to the second branch flow path 32.

[0030] The flow rate switching valve 40 switches to state 40a when no oil flows through the first actuator 41 and the second actuator 42. When oil flows through the first actuator 41 and no oil flows through the second actuator 42, the flow rate switching valve 40 opens due to the hydraulic pressure of the oil flowing through the first actuator 41, and switches to state 40b.

[0031] 4 is a diagram showing the flow rate switching valve 40 switched to state 40b. The hydraulic control device 3 shown in FIG. 4 differs from the hydraulic control device 3 shown in FIG. 2 in that the drive source 14 drives the pump 12, causing the pump 12 to discharge oil into the first flow path 16, and in that the state of the flow rate switching valve 40 is state 40b, but is the same in other respects. As shown in FIG. 4, in the flow rate switching valve 40, the oil discharged by the pump 12 into the first flow path 16 flows through the second flow path 30 and the fourth branch flow path 35 to the first actuator 41, but does not flow to the second actuator 42 because the solenoid valve 45 is closed. Therefore, the flow rate switching valve 40 switches to state 40b due to the hydraulic pressure of the oil flowing to the first actuator 41.

[0032] When oil flows to the first actuator 41 and the second actuator, the flow rate switching valve 40 opens due to the hydraulic pressure of the oil flowing through the first actuator 41 and the second actuator, and switches to state 40c. Fig. 5 is a diagram showing the flow rate switching valve 40 switched to state 40c. The hydraulic control device 3 shown in Fig. 5 differs from the hydraulic control device 3 shown in Fig. 4 in that the regulator valve control section 50 excites the solenoid 46, the solenoid valve 45 is open to direct oil to the second actuator 42, and the state of the flow rate switching valve 40 is state 40c, but is the same in other respects.

[0033] 5, in the flow rate switching valve 40, the oil discharged by the pump 12 into the first flow path 16 flows to the first actuator 41 via the second flow path 30 and the fourth branch flow path 35, and also flows to the second actuator 42 via the second flow path 30 and the third branch flow path 34. Therefore, the flow rate switching valve 40 switches to state 40c due to the hydraulic pressure of the oil flowing to the first actuator 41 and the second actuator 42.

[0034] The solenoid valve 45 is a third adjustment valve provided in the third branch flow path 34 that branches off from a branch point J3 downstream of the branch point J1 in the second flow path 30 and upstream of the first branch flow path 31 and the second branch flow path 32. The solenoid valve 45 switches whether or not to direct the oil flowing through the third branch flow path 34 to the flow rate switching valve 40. A state 45a shown in FIG. 2 indicates a state in which the solenoid valve 45 is closed to prevent the oil flowing through the third branch flow path 34 from being directed toward the second actuator 42, and directs the oil from the second actuator 42 to the oil pan 10. A state 45b shown in FIG. 2 indicates a state in which the solenoid valve 45 is open to direct the oil flowing through the third branch flow path 34 toward the second actuator 42.

[0035] The solenoid valve 45 switches to state 45a when the regulator valve control unit 50 does not energize the solenoid 46. On the other hand, as shown in Fig. 5, the solenoid valve 45 switches to state 45b when the regulator valve control unit 50 energizes the solenoid 46. By operating the solenoid valve 45 in this manner, the regulator valve control unit 50 can switch the state of the flow rate switching valve 40 to state 40c by energizing the solenoid 46 while the pump 12 is supplying oil.

[0036] The control valve control unit 50 controls the opening and closing of the proportional valve 20, the flow rate switching valve 40, and the solenoid valve 45 by performing an excitation operation or a de-excitation operation for each of the solenoids 21 and 46. The control valve control unit 50 controls the opening and closing of the proportional valve 20, the flow rate switching valve 40, and the solenoid valve 45 so as not to decrease the oil pressure when the actuation target 1 is actuated.

[0037] <Configuration of the regulator valve control unit 50> 2, the regulator valve control unit 50 has a storage unit 51 and a processor 52. The processor 52 has an acquisition unit 521 and a switching unit 522.

[0038] The storage unit 51 has a storage medium such as a ROM (Read Only Memory), a RAM (Random Access Memory), an HDD (Hard Disk Drive), or an SSD (Solid State Drive). The storage unit 51 stores a program executed by the processor 52 and various information used by the regulator valve control unit 50 to control the opening and closing of the proportional valve 20, the flow rate switching valve 40, and the solenoid valve 45 so that the oil pressure does not decrease when the actuation target 1 is actuated.

[0039] The processor 52 is a processor such as a CPU or an ECU. The processor 52 functions as an acquisition unit 521 and a switching unit 522 by executing a program stored in the storage unit 51. The processor 52 may be configured as a single processor, or may be configured as a combination of multiple processors or one or more processors and an electronic circuit.

[0040] The acquisition unit 521 acquires the oil temperature of the oil stored in the oil pan 10 from the temperature sensor 11. The acquisition unit 521 acquires the oil pressure of the oil flowing through the first flow path 16 from the pressure sensor 17. The acquisition unit 521 acquires gear shift determination information indicating whether or not to shift gears in the transmission including the operation target 1 from the control device 2. The acquisition unit 521 acquires the oil temperature, oil pressure, and gear shift determination information at predetermined intervals, such as 10 msec, for example.

[0041] The switching unit 522 switches the flow path through which the oil flows by controlling the proportional valve 20 and the flow rate switching valve 40. For example, when the acquiring unit 521 acquires shift determination information indicating that the transmission is to be shifted, the switching unit 522 controls the proportional valve 20 and the flow rate switching valve 40 to direct the oil to the operating object 1 in order to operate the operating object 1 that is not receiving a supply of oil.

[0042] When operating an actuation target 1 that is not receiving oil supply, if the hydraulic pressure in the first flow path 16 upstream of the actuation target 1 is less than the hydraulic pressure threshold, the switching unit 522 switches the flow rate switching valve 40 so that the oil directed to the first branch flow path 31 is directed to the second branch flow path 32. Subsequently, after switching the flow rate switching valve 40, the switching unit 522 switches the proportional valve 20 so that the oil is directed to the actuation target 1. The hydraulic pressure is, for example, the hydraulic pressure detected by the pressure sensor 17. The hydraulic pressure threshold is the minimum hydraulic pressure for actuating the actuation target 1 at a predetermined speed (for example, 0.03 m / s), and is, for example, 1 MPa. The hydraulic pressure threshold is stored in the memory unit 51.

[0043] For example, as in the hydraulic control device 3 shown in Fig. 4, when the state of the flow rate switching valve 40 is state 40b due to the pump 12 supplying oil, the switching unit 522 determines that the oil pressure detected by the pressure sensor 17 is less than the oil pressure threshold. In this case, as in the hydraulic control device 3 shown in Fig. 5, the switching unit 522 energizes the solenoid 46 of the electromagnetic valve 45 to direct the oil flowing through the third branch flow path 34 to the second actuator 42 of the flow rate switching valve 40.

[0044] By operating in this manner, the state of the flow rate switching valve 40 switches from state 40b to state 40c due to the pressure of the oil flowing to the second actuator 42. In other words, the switching unit 522 can switch the flow rate switching valve 40 so that the oil flowing to the first branch flow path 31 is directed to the second branch flow path 32 due to the pressure of the oil that is directed from the third branch flow path 34 to the second actuator 42 by exciting the solenoid valve 45.

[0045] Subsequently, after the state of the flow rate switching valve 40 has switched to state 40c, the switching unit 522 applies a voltage to the solenoid 21 of the proportional valve 20, thereby switching the state of the proportional valve 20 from state 20a to state 20b. FIG. 6 is a diagram showing the hydraulic control device 3 after the state of the proportional valve 20 has been switched. The hydraulic control device 3 shown in FIG. 6 differs from the hydraulic control device 3 shown in FIG. 5 in that the switching unit 522 applies a voltage to the solenoid 21, switching the state of the proportional valve 20 from state 20a to state 20b, and in that the oil flowing through the first flow path 16 flows into the actuation target 1, but is otherwise the same. As shown in FIG. 6, when actuating the actuation target 1, if the hydraulic pressure is less than the hydraulic pressure threshold, the switching unit 522 directs the oil flowing through the first flow path 16 toward the actuation target 1 while the oil flowing through the second flow path 30 directs the oil flowing through the second branch flow path 32.

[0046] By operating in this manner, when the hydraulic pressure drops, the switching unit 522 can direct the oil flowing through the second flow path 30 to the second branch flow path 32, through which a second flow rate that is smaller than the first flow rate of the oil flowing through the first branch flow path 31 flows. Therefore, when the hydraulic pressure drops, the switching unit 522 can reduce the flow rate of oil flowing from the first flow path 16 to the second flow path 30 and increase the flow rate of oil flowing from the first flow path 16 to the actuation target 1. As a result, even when the hydraulic pressure drops due to a decrease in the discharge efficiency of the pump 12 accompanying an increase in oil temperature, the switching unit 522 can suppress a decrease in the hydraulic pressure of the oil directed to the actuation target 1 when shifting gears in the transmission.

[0047] Furthermore, in the hydraulic control device 3, a drop in hydraulic pressure can be suppressed without setting the amount of oil discharged by the pump 12 to an amount greater than the amount of oil required by the actuation target 1, so it is possible to lower the rotation speed of the pump 12 or reduce the size of the pump 12. As a result, in the hydraulic control device 3, it is possible to reduce the amount of energy consumed to discharge oil.

[0048] On the other hand, when operating an actuation target 1 that is not receiving oil supply, if the hydraulic pressure is equal to or higher than the hydraulic pressure threshold, the switching unit 522 switches the proportional valve 20 so that oil is directed to the actuation target 1 while directing the oil to the first branch flow path 31. For example, as in the hydraulic control device 3 shown in FIG. 4, when the flow rate switching valve 40 is in state 40b due to the pump 12 supplying oil, the switching unit 522 determines that the hydraulic pressure detected by the pressure sensor 17 is equal to or higher than the hydraulic pressure threshold stored in the memory unit 51. In this case, since the hydraulic pressure is equal to or higher than the hydraulic pressure threshold, the switching unit 522 applies a voltage to the solenoid 21 to switch the state of the proportional valve 20 to state 20b.

[0049] FIG. 7 is a diagram illustrating the operation of the hydraulic control device 3 when the hydraulic pressure is equal to or higher than the hydraulic pressure threshold value. The hydraulic control device 3 illustrated in FIG. 7 differs from the hydraulic control device 3 illustrated in FIG. 4 in that the switching unit 522 applies a voltage to the solenoid 21, switching the state of the proportional valve 20 from state 20a to state 20b, and oil flows from the first flow path 16 into the actuation target 1, but is otherwise the same. As illustrated in FIG. 7, when the actuation target 1 is actuated, if the hydraulic pressure is equal to or higher than the hydraulic pressure threshold value, the switching unit 522 directs the oil flowing through the first flow path 16 toward the actuation target 1 while the oil flowing through the second flow path 30 is directed toward the first branch flow path 31. By operating in this manner, the switching unit 522 actuates the actuation target 1 and causes the cooler 33 to cool the oil flowing through the first branch flow path 31.

[0050] Since the oil pressure of the oil discharged by the pump 12 decreases as the oil temperature of the oil increases, the switching unit 522 needs to increase the amount of oil directed to the actuation target 1 as the oil temperature increases, thereby suppressing the decrease in oil pressure. Therefore, the switching unit 522 determines the valve opening degree and the open time of the proportional valve 20 based on the oil temperature detected by the temperature sensor 11.

[0051] The switching unit 522 acquires, for example, a rectangular wave map stored in the memory unit 51, which indicates the application time for applying a voltage to the proportional valve 20 and the current to be applied to apply the voltage to the proportional valve 20, corresponding to the oil temperature of the oil stored in the oil pan 10. Then, by referring to the rectangular wave map, the switching unit 522 determines the application time and current corresponding to the oil temperature acquired by the acquisition unit 521, and then causes the current to flow through the proportional valve 20 for the application time.

[0052] FIG. 8 shows an example of a rectangular wave map and a current flowing through the proportional valve 20. FIG. 8(a) shows the rectangular wave map, and FIG. 8(b) shows an example of a current flowing through the proportional valve 20 (solenoid 21) by the switching unit 522. As shown in FIG. 8(a), the rectangular wave map is a map showing a current corresponding to oil temperature and its application time. The horizontal axis of FIG. 8(b) represents time, and the vertical axis represents the current flowing through the solenoid 21. The current a0 shown in FIG. 8(b) is a current for outputting a control signal to the solenoid 21. Therefore, the proportional valve 20 closes when the current a0 flows, and opens when a current greater than the current a0 (for example, currents a1 to a4 shown in FIG. 8) flows. Furthermore, the proportional valve 20 opens more when a larger current flows.

[0053] At time T0 shown in FIG. 8(b), the switching unit 522, for example, by referring to a rectangular wave map, identifies the current a and application time s2 corresponding to the oil temperature D2 acquired by the acquisition unit 521. Then, the switching unit 522 applies the current a2 to the solenoid 21 from time T0 to time T1, when the application time s2 has elapsed. As a result, the proportional valve 20 opens at a valve opening corresponding to the current a2 from time T0 to time T1, thereby directing the oil flowing through the first flow path 16 toward the actuation target 1. By operating in this manner, the switching unit 522 can determine the valve opening (current) and valve opening time (application time) according to the oil temperature, even when the oil temperature rises, and can therefore direct the oil toward the actuation target 1 while suppressing a drop in oil pressure.

[0054] Some vehicles are equipped with a pressure sensor 17, while others are not. When the hydraulic control device 3 is installed in a vehicle that does not have a pressure sensor 17, the switching unit 522 cannot determine whether the hydraulic pressure is equal to or higher than the hydraulic pressure threshold. Therefore, the switching unit 522 may identify the hydraulic pressure of the first flow path 16 corresponding to the temperature of the oil stored in the oil pan 10. The switching unit 522 identifies the hydraulic pressure corresponding to the oil temperature acquired by the acquisition unit 521, for example, by referring to a hydraulic pressure map that indicates the hydraulic pressure corresponding to the oil temperature and is stored in the memory unit 51. By operating in this manner, the switching unit 522 can direct oil to the actuation target 1 without reducing the hydraulic pressure, even in a vehicle that does not have a pressure sensor 17.

[0055] After the transmission has performed a gear change, the switching unit 522 switches the state of the proportional valve 20 from state 20b to state 20a by ending the application of voltage to the solenoid 21, closing the valve, and directing the oil that has flowed into the actuation target 1 to the oil pan 10. It is desirable that the oil stored in the oil pan 10 be managed so that the oil temperature does not rise, so as to prevent a drop in oil pressure when the transmission performs another gear change. Therefore, after directing the oil to the actuation target 1, the switching unit 522 may switch between directing the oil to the first branch flow path 31 or the second branch flow path 32 based on the oil temperature acquired by the acquisition unit 521.

[0056] For example, when the oil temperature acquired by the acquisition unit 521 is equal to or higher than an oil temperature threshold, the switching unit 522 directs the oil to the first branch flow path 31, and when the oil temperature is lower than the oil temperature threshold, the switching unit 522 directs the oil to the second branch flow path 32. The oil temperature threshold is, for example, a fixed value between 80°C and 85°C, and is stored in the storage unit 51. By operating in this manner, when the oil temperature is equal to or higher than the oil temperature threshold, the switching unit 522 can cool the oil by directing the oil to the first branch flow path 31, which is provided with the cooler 33. On the other hand, when the oil temperature is lower than the oil temperature threshold, the switching unit 522 can prevent the oil temperature from becoming excessively low by directing the oil to the second branch flow path 32, which is not provided with the cooler 33.

[0057] <Processing sequence in hydraulic control device 3> Fig. 9 is a diagram showing an example of a processing sequence in the hydraulic control device 3. The processing sequence shown in Fig. 9 is a processing sequence showing an example of an operation in which the hydraulic control device 3 controls the hydraulic pressure and oil temperature when the transmission performs a gear change. The hydraulic control device 3 repeats the processing sequence shown in Fig. 9 at a predetermined cycle.

[0058] The acquisition unit 521 acquires the oil temperature detected by the temperature sensor 11, the oil pressure detected by the pressure sensor 17, and the gear shift determination information output by the control device 2 (step S11). When the acquisition unit 521 acquires the gear shift determination information indicating that the transmission is to be shifted (YES in step S12), the switching unit 522 determines whether the oil pressure acquired by the acquisition unit 521 is equal to or greater than the oil pressure threshold (step S13). When the oil pressure is equal to or greater than the oil pressure threshold (YES in step S13), the switching unit 522 refers to the rectangular wave map stored in the memory unit 51 to identify the application time of voltage to the proportional valve 20 and the current during application that correspond to the oil temperature acquired by the acquisition unit 521 (step S15).

[0059] If the oil pressure is less than the oil pressure threshold value (NO in step S13), the switching unit 522 energizes the solenoid 46 to open the solenoid valve 45, thereby directing the oil from the third branch flow path 34 to the second actuator 42. Then, the switching unit 522 switches the state of the flow rate switching valve 40 from state 40b to state 40c using the oil pressure of the oil flowing to the second actuator 42, thereby directing the oil that has been directed to the first branch flow path 31 to the second branch flow path 32 (step S14). Next, the switching unit 522 refers to the rectangular wave map stored in the memory unit 51 to identify the application time of voltage to the proportional valve 20 and the current during application, which correspond to the oil temperature acquired by the acquisition unit 521 (step S15).

[0060] The switching unit 522 causes the specified current to flow to the solenoid 21 for the specified application time, and directs the oil flowing through the first flow path 16 toward the actuation target 1, thereby causing the transmission to shift gears (step S16). After the transmission has shifted gears, the switching unit 522 ends the process of passing the current to the solenoid 21, thereby switching the state of the proportional valve 20 from state 20b to state 20a, causing the valve to close, and directing the oil that has flowed into the actuation target 1 toward the oil pan 10.

[0061] When the switching unit 522 has finished the process of passing a current to the solenoid 21, or when the acquisition unit 521 has acquired shift determination information indicating that the transmission will not be shifted (NO in step S12), the switching unit 522 determines whether the oil temperature is equal to or higher than the oil temperature threshold (step S17). When the oil temperature is equal to or higher than the oil temperature threshold (YES in step S17), the switching unit 522 switches the state of the flow rate switching valve 40 to state 40b by not energizing the solenoid 46, and directs the oil to the first branch flow path 31 (step S18). When the oil temperature is lower than the oil temperature threshold (NO in step S17), the switching unit 522 energizes the solenoid 46, and switches the state of the flow rate switching valve 40 to state 40c, and directs the oil to the second branch flow path 32 (step S19).

[0062] <Effects of hydraulic control device 3> As described above, the hydraulic control device 3 includes: a pump 12 that supplies oil; a first flow path 16 that connects the pump 12 to an operating object 1 that is operated by the oil pressure of the oil and through which oil flows from the pump 12 to the operating object 1; a proportional valve 20 that is provided in the first flow path 16 and switches whether or not oil is to be directed from the pump 12 to the operating object 1; a second flow path 30 that is connected to a branch point J1 upstream of the proportional valve 20 in the first flow path 16 and that branches off downstream of the branch point J1 and includes a first branch flow path 31 through which oil flows at a first flow rate and a second branch flow path 32 through which oil flows at a second flow rate that is less than the first flow rate; a flow rate switching valve 40 that is provided in the second flow path 30 and switches whether the oil is to be directed to the first branch flow path 31 or the second branch flow path 32; and a switching unit 522 that switches the flow path through which the oil flows by controlling the proportional valve 20 and the flow rate switching valve 40.

[0063] With the hydraulic control device 3 configured in this manner, if the hydraulic pressure is low when the transmission performs a gear shift, the switching unit 522 can reduce the flow rate of oil flowing from the first flow path 16 to the second flow path 30 and increase the flow rate of oil flowing from the first flow path 16 to the actuation target 1. As a result, even if the hydraulic pressure is low due to a decrease in the discharge efficiency of the pump 12 accompanying an increase in oil temperature, the switching unit 522 can suppress a decrease in the hydraulic pressure of the oil directed to the actuation target 1 when the transmission shifts gears.

[0064] Furthermore, since the hydraulic control device 3 can suppress a drop in hydraulic pressure as described above, it can suppress a drop in hydraulic pressure without setting the amount of oil discharged by the pump 12 to an amount greater than the amount of oil required by the actuation target 1. As a result, in the hydraulic control device 3, it is possible to lower the rotation speed of the pump 12 or reduce the size of the pump 12, thereby reducing the amount of energy consumed to discharge oil.

[0065] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by functionally or physically distributing or integrating any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combination also have the effects of the original embodiments. [Explanation of symbols]

[0066] 1. Target of operation 2. Control device 3 Hydraulic control device 10 Oil pan 11 Temperature Sensor 12 Pump 13 Filters 14 Power Source 15 Relief valve 16 First Flow Path 17 Pressure Sensor 20 Proportional valve 21 Solenoid 30 Second Flow Path 31 First branch channel 32 Second branch channel 33 Cooler 34 Third branch channel 35 Fourth Branch 40 Flow switching valve 41 First Actuator 42 Second Actuator 45 Solenoid valve 46 Solenoid 50 Control valve control section 51 Storage section 52 processors 521 Acquisition Department 522 Switching section

Claims

1. a pump for supplying oil; a first flow path connecting the pump to an operating object operated by the oil pressure of the oil, through which the oil flows from the pump to the operating object; a first control valve provided in the first flow path and configured to switch whether or not the oil is directed from the pump to the actuation target; a second flow path connected to a branch point on the upstream side of the first control valve in the first flow path, the second flow path branching downstream of the branch point and including a first branch flow path through which the oil flows at a first flow rate and a second branch flow path through which the oil flows at a second flow rate less than the first flow rate; a second control valve provided in the second flow path and configured to switch whether the oil is directed to the first branch flow path or the second branch flow path; a switching unit that switches the flow path through which the oil flows by controlling the first adjustment valve and the second adjustment valve, When operating the operation target that is not supplied with oil, if the hydraulic pressure in the first flow path upstream of the operation target is less than a hydraulic pressure threshold, the switching unit switches the second control valve to direct the oil that is being directed to the first branch flow path to the second branch flow path, and then switches the first control valve to direct the oil to the operation target. Hydraulic control device.

2. a third control valve that is provided in a third branch flow path that branches off from the second flow path downstream of the branch point and upstream of the first branch flow path and the second branch flow path, and that switches whether or not the oil flowing through the third branch flow path is directed to the second control valve; the switching unit energizes the third control valve to direct the oil flowing through the third branch flow path to the second control valve, and switches the second control valve by the oil pressure of the oil so that the oil flowing through the first branch flow path is directed to the second branch flow path. The hydraulic control device according to claim 1 .

3. When operating the operation target that is not supplied with the oil, if the hydraulic pressure is equal to or higher than the hydraulic pressure threshold, the switching unit switches the first control valve so as to direct the oil to the operation target while directing the oil to the first branch flow path. The hydraulic control device according to claim 1 .

4. an acquisition unit that acquires an oil temperature of the oil stored in an oil pan; a storage unit that stores the oil pressure corresponding to the oil temperature, The switching unit identifies the oil pressure corresponding to the oil temperature acquired by the acquisition unit by referring to the storage unit. The hydraulic control device according to claim 1 .

5. an acquisition unit that acquires an oil temperature of the oil stored in an oil pan; a storage unit that stores a map indicating an application time for applying a voltage to the first control valve and an electric current to apply the voltage to the first control valve, the application time corresponding to an oil temperature of the oil stored in the oil pan, the switching unit, by referring to the storage unit, determines the application time and the current corresponding to the oil temperature acquired by the acquisition unit, and then applies the current to the first control valve for the application time. The hydraulic control device according to claim 1 .

6. an acquisition unit that acquires the oil temperature of the oil stored in the oil pan; the switching unit switches whether to direct the oil to the first branch flow path or the second branch flow path based on the oil temperature acquired by the acquisition unit after directing the oil to the actuation target. The hydraulic control device according to claim 1 .

7. The switching unit directs the oil to the first branch flow path when the oil temperature acquired by the acquisition unit is equal to or higher than an oil temperature threshold, and directs the oil to the second branch flow path when the oil temperature is lower than the oil temperature threshold. The hydraulic control device according to claim 6.

8. The processor executes When an operating object operated by oil pressure is operated from a state in which the operating object is not supplied with oil, a pump that supplies the oil is connected to the operating object, and if the oil pressure upstream of the operating object in a first flow path through which the oil flows from the pump to the operating object is less than a threshold value, the method includes a switching step of switching the oil that is directed to the first branch flow path, which is branched downstream of a second flow path branched from the first flow path and through which the oil flows at a first flow rate, to be directed to the second branch flow path, and then directing the oil to the operating object. Hydraulic control method.

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