JP2012077800A - Hydraulic control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic control device that can reduce frequency of supply and discharge of pressure oil in hydraulic control of an actuator.SOLUTION: The hydraulic control device includes: a hydraulic supply means 4 for selectively switching between a state in which pressure oil is supplied from hydraulic sources 1, 5 to the actuator 7 and a state of stopping the supply; and a hydraulic discharge means 10 for selectively switching between a state of discharging the pressure oil of the actuator 7 and a state of stopping the discharge. A hydraulic control means 8 communicates with the actuator 7, which is constituted to reduce hydraulic pressure of the actuator 7 by receiving and accumulating the pressure oil of the actuator 7 and to increase the hydraulic pressure of the actuator 7 by supplying the accumulated oil pressure to the actuator 7 in a state of stopping the hydraulic supply means 4 and the hydraulic discharge means 10, respectively.

Description

  The present invention relates to a hydraulic control device that controls the hydraulic pressure of an actuator that is driven by supplying and discharging hydraulic pressure.

  2. Description of the Related Art Conventionally, a hydraulic control device configured to engage a clutch, a brake, or the like by supplying hydraulic pressure is known. Further, in a continuously variable transmission that can continuously change the gear ratio among the automatic transmissions of the vehicle, the hydraulic pressure is supplied and discharged to change the gear ratio, or the clamping force of the power transmission member in the transmission is changed. What to set is known.

  Patent Document 1 and Patent Document 2 describe a belt-type continuously variable transmission including a pair of pulleys and a belt that is wound around those pulleys and transmits torque. In the belt type continuously variable transmission, actuators are provided in the respective pulleys, and a hydraulic pressure supply control valve that supplies hydraulic pressure to the actuators and a hydraulic pressure discharge control valve that discharges pressure oil of the actuator are provided. ing. Therefore, the belt-type continuously variable transmission described in Patent Document 1 and Patent Document 2 includes a hydraulic pressure supply control valve, a hydraulic pressure discharge control valve, and the like, when changing a gear ratio or changing a clamping pressure. Either or both of these are configured to be opened and closed.

European Patent No. 0985855 International Publication No. 2010/021218 Pamphlet

  The devices described in Patent Document 1 and Patent Document 2 described above include a hydraulic pressure supply control valve and a hydraulic pressure discharge control valve, and these control valves can be opened and closed using electromagnetic force. It is a control valve that can. Therefore, for example, when the transmission ratio is kept constant, each control valve may be closed. However, when lowering the hydraulic pressure of an actuator, the pressure oil of the hydraulic circuit connected to the actuator or the actuator is discharged to an oil pan or outside air, so the frequency of use of the oil pump that supplies the pressure oil increases. End up. Further, when increasing the pressure, it is performed by supplying pressure oil from an oil pump or an actuator. However, since the oil pressure of these oil pumps and actuators is high, there is a great difference in hydraulic pressure from the required oil pressure in the hydraulic control of the actuator. In some cases, it may be necessary to control pressure reduction while supplying pressure oil.

  This invention pays attention to the technical problem mentioned above, and it aims at providing the hydraulic control apparatus which can reduce the supply and discharge frequency of pressure oil in the hydraulic control of an actuator.

  In order to achieve the above object, the invention according to claim 1 is directed to a hydraulic pressure supply means capable of selectively switching between a state in which pressure oil is supplied to the actuator from a hydraulic power source and a state in which the supply is stopped, and a pressure oil in the actuator. In the hydraulic control device comprising a hydraulic pressure discharge means that can selectively switch between a state of discharging the pressure and a state of stopping the discharge, the actuator in a state where each of the hydraulic pressure supply means and the hydraulic pressure discharge means is stopped Hydraulic pressure control means configured to reduce the hydraulic pressure of the actuator by receiving and accumulating pressure oil from the pressure, and to increase the hydraulic pressure of the actuator by supplying the accumulated hydraulic pressure to the actuator; It is characterized by communicating with an actuator.

  According to a second aspect of the present invention, in the configuration of the first aspect, the hydraulic control means increases the volume of the hydraulic chamber, accumulates the hydraulic pressure of the actuator to reduce the hydraulic pressure of the actuator, and reduces the volume of the hydraulic chamber. 2. The hydraulic control device according to claim 1, wherein the hydraulic pressure of the actuator can be increased by supplying a hydraulic pressure that is reduced and accumulated in the actuator.

  A third aspect of the present invention is the hydraulic control device according to the first or second aspect, wherein the hydraulic pressure control means includes a cylinder and a piston that slides in the cylinder.

  According to the present invention, the hydraulic pressure supply means that can selectively switch between a state in which pressure oil is supplied from the hydraulic source to the actuator and a state in which the supply is stopped, the state in which the pressure oil is discharged from the actuator, and the discharge are stopped. Since hydraulic discharge means that can selectively switch the state is provided, the hydraulic pressure of the actuator can be increased or decreased by switching each means. Further, with each of the hydraulic pressure supply means and the hydraulic pressure discharge means being stopped, the hydraulic pressure of the actuator is reduced by accumulating the hydraulic pressure of the actuator, and the accumulated hydraulic pressure is supplied to the actuator. Since the hydraulic pressure control means configured to increase the hydraulic pressure communicates with the hydraulic pressure supply means and the actuator, the hydraulic pressure of the actuator can be controlled without discharging the hydraulic pressure of the actuator. Therefore, the energy consumption for driving the hydraulic pressure supply means and the hydraulic pressure discharge means, the energy consumption for driving the hydraulic pressure source, and the like can be reduced.

1 is a schematic diagram illustrating a configuration example of a hydraulic control device according to the present invention. It is a flowchart for demonstrating the example of control.

  Next, the hydraulic control apparatus according to the present invention will be described by way of example. FIG. 1 schematically shows the hydraulic circuit. First, a configuration example of a hydraulic control device according to the present invention will be described. An oil pump 1 as a hydraulic power source of the hydraulic circuit is provided for pumping up oil stored in an oil pan 2 and supplying it to each member. Yes. The oil pump 1 is connected to a motor 3 for driving the oil pump 1. When this hydraulic control device is mounted on a vehicle, an internal combustion engine or an electric motor that is a power source of the vehicle and the oil pump 1 may be connected and driven by the power source.

  The pressure oil output from the oil pump 1 is supplied to the supply solenoid valve 4 through an oil passage A communicating with the oil pump 1. The supply solenoid valve 4 uses a poppet valve that seals a valve body in close contact with an input port. Here, the poppet type solenoid valve will be briefly described. The poppet type solenoid valve has a shaft that is a magnetic body formed integrally with the valve body, and a spring that presses the shaft toward the input port side. On the outer peripheral side of the shaft, a coil for generating an electromagnetic force is disposed in a direction in which the shaft is opposed to the spring force. Therefore, this poppet type solenoid valve is configured to open and close the input port according to the value of the current flowing through the coil.

  An accumulator 5 that is a pressure accumulator communicates with the oil passage A. That is, the supply solenoid valve 4 is configured to be supplied with at least one of the pressure oil pumped up by the oil pump 1 and the pressure oil accumulated in the accumulator 5. The oil passage A is provided with a hydraulic pressure detector 6 that detects the oil pressure in the oil passage A.

  A cylinder 8 communicating with the oil passage B is provided between the oil passage B communicating with the output port of the supply solenoid valve 4 and the clutch 7 corresponding to the actuator of the present invention. The cylinder 8 includes an oil chamber 8a communicating with the oil passage B, a piston 9 that changes the volume of the oil chamber 8a, and another oil chamber 8b provided at a position facing the oil chamber 8a via the piston 9. It consists of and. The oil chamber 8b is connected to a hydraulic circuit (not shown), and is configured such that the piston 9 moves back and forth (in the example illustrated in the left-right direction) by supplying and discharging hydraulic pressure to and from the oil chamber 8b. ing. That is, the piston 9 is configured to move back and forth by the relationship between the hydraulic pressure acting on the pressure receiving surface on the oil chamber 8a side and the hydraulic pressure acting on the pressure receiving surface on the oil chamber 8b side. That is, when the oil pressure in the oil chamber 8a or the oil passage B is increased, the oil pressure in the oil chamber 8b is increased, and on the contrary, when the oil chamber 8a or the oil passage B is reduced, the oil chamber 8b. The hydraulic pressure is reduced. The configuration example described above as the mechanism for driving the piston 9 uses hydraulic pressure, but is not limited to this. For example, a mechanism using a motor may be used, or the hydraulic control device may be used in a vehicle. In the case of being mounted, a mechanical mechanism in which an accelerator pedal (not shown) and the piston 9 are connected by a cable may be used.

  In addition, a discharge solenoid valve 10 communicates with the oil passage B. The discharge solenoid valve 10 is also a poppet-type solenoid valve, similar to the supply solenoid valve 4 described above, and is configured to open and close the output port in accordance with the current value flowing through the coil. The output port of the discharge solenoid valve 10 and the oil pan 2 communicate with each other. That is, the pressure oil in the oil passage B can be discharged to the oil pan 2 by opening the output port. Further, the oil passage B is provided with a hydraulic pressure detector (Pcb) 11 that detects the oil pressure in the oil passage B. The supply solenoid valve 4 and the discharge solenoid valve 10 described above are not limited to poppet type solenoid valves, but may be solenoid valves using spool valves, or hydraulic drive whose opening / closing operation is controlled by hydraulic pressure. It may be a valve. The point is that the piston 9 can be moved back and forth and the operation of the piston 9 can be controlled. In short, any valve that can control the opening and closing operation may be used.

  The above-described hydraulic control device (not shown) for supplying hydraulic pressure to the motor 3, the solenoid valves 4, 10 or the hydraulic pressure detectors 6, 11 or the oil chamber 8b is electrically connected to an electronic control unit (ECU) 12. Yes. That is, when a signal detected by the oil pressure detector 6 is input to the electronic control unit 12 and the oil pressure in the oil passage A is increased, a current is supplied to the motor 3 based on the signal detected by the oil pressure detector 6. Is supplied to drive the oil pump 1. When there is a request to change the engagement force of the clutch 7, a signal (actual oil pressure) detected by the oil pressure detector 6 and inputted to the electronic control device 12 and a required oil pressure (target oil pressure) are obtained. In comparison, based on the deviation between the actual hydraulic pressure and the target hydraulic pressure, a current or signal is input from the electronic control device 12 to the hydraulic control device for driving the solenoid valves 4, 10 and the piston 9. Yes.

  Next, a control example of the hydraulic control device according to the present invention will be described. The control example described here is control for increasing or decreasing the hydraulic pressure in the clutch 7 or the oil passage B. A flowchart for explaining the control example is shown in FIG. First, it is determined whether or not both the supply solenoid valve 4 and the discharge solenoid valve 10 are closed (step S1). When a negative determination is made in step S1, the pressure oil is being supplied into the oil passage B or the pressure oil in the oil passage B is being discharged. Therefore, the control is temporarily terminated while maintaining the supply state or the discharge state. That is, since this control flow is repeatedly executed in an extremely short time, when the control before this control is continued, the previous control is continued and new control is not performed.

  If the determination in step S1 is affirmative, that is, both the supply solenoid valve 4 and the discharge solenoid valve 10 are closed, the hydraulic circuit of the oil passage B including the oil chamber 8a of the cylinder 8 is closed. Since it is sealed, the oil pressure in the oil passage B can be changed by driving the piston 9 with the oil pressure in the oil passage B. Therefore, if a positive determination is made in step S1, it is determined whether or not the hydraulic pressure (actual hydraulic pressure) of the clutch 7 is lower than the target hydraulic pressure required for the clutch 7 (step S2). Note that the target hydraulic pressure is a hydraulic pressure that includes an allowable slight difference (α) in the hydraulic pressure of the clutch 7. If the determination in step S2 is affirmative, the actual hydraulic pressure of the clutch 7 is lower than the target hydraulic pressure, so the hydraulic pressure of the clutch 7 needs to be increased. Therefore, in order to select the means for increasing the pressure, it is determined whether or not the piston 9 can move in the pressure increasing direction (step S3). In the example shown in FIG. 1, it is determined whether or not the piston 9 can move leftward.

  If the determination in step S3 is affirmative, that is, if the piston 9 can move in the pressure increasing direction, the piston 9 is moved in the pressure increasing direction (step S4) and the oil pressure in the oil passage B and the clutch 7 is increased. The pressure is increased and this control is finished once. On the other hand, if a negative determination is made in step S3, that is, if the piston 9 cannot move in the pressure increasing direction, the piston 9 is moved in the pressure reducing direction while the supply solenoid valve 4 is opened (step S5). This control is once terminated. That is, by opening the supply solenoid valve 4, the piston 9 is moved to a substantially central portion of the cylinder 8 while increasing the oil pressure of the oil passage B and the actuator 7. Therefore, when the oil pressure of the oil passage B and the actuator 7 is increased or decreased again, the piston 9 can be driven and controlled.

  The above-described control from step S3 to step S5 is control for increasing the hydraulic pressure of the clutch 7, but when a negative determination is made in step S2, that is, when the actual hydraulic pressure of the clutch 7 is equal to or lower than the target hydraulic pressure. Then, it is selected whether the hydraulic pressure of the clutch 7 is reduced or maintained. Therefore, it is determined whether or not the actual hydraulic pressure of the clutch 7 is higher than the target hydraulic pressure (step S6). The target hydraulic pressure is a hydraulic pressure that includes a slight difference (α) that permits the hydraulic pressure of the clutch 7 as in the target hydraulic pressure determined in step S2. If the determination in step S6 is negative, the actual hydraulic pressure of the clutch 7 matches the target hydraulic pressure, so this control is temporarily terminated without any particular control. On the contrary, if a negative determination is made in step S6, that is, if the actual oil pressure of the clutch 7 is higher than the target oil pressure, the oil pressure of the clutch 7 needs to be reduced, and the pressure reducing means is selected. That is, it is determined whether or not the piston 9 can move in the pressure reducing direction (step S7). If a positive determination is made in step S7, that is, if the piston 9 can move in the pressure reducing direction, the piston 9 is moved in the pressure reducing direction (step S8), and the oil pressure in the oil passage B and the clutch 7 is reduced. Thus, this control is temporarily terminated. On the other hand, if a negative determination is made in step S7, that is, if the piston 9 cannot move in the pressure reducing direction, the piston 9 is moved in the pressure increasing direction while opening the discharge solenoid valve 10 (step S9). This control is once terminated. Similarly to the control in step S5 described above, the control in step S9 is also performed by opening the discharge solenoid valve 10 to reduce the oil pressure in the oil passage B and the actuator 7, and the piston 9 is substantially at the center of the cylinder 8. Move to the department. Therefore, when the oil pressure of the oil passage B and the actuator 7 is increased or decreased again, the piston 9 can be driven and controlled.

  As described above, when the oil pressure of the oil passage B and the clutch 7 can be increased or decreased by the movement of the piston 9, the pressure in the oil passage B and the clutch 7 is increased or decreased only by the movement of the piston 9. The oil pressure can be changed using oil. Accordingly, since the frequency of discharging the pressure oil at the time of depressurization is reduced, the driving frequency of the oil pump 1 can be reduced. Further, when pressure oil is supplied from the oil pump 1 or the accumulator 5 at the time of pressure increase, the oil pressure is high, so that the oil pressure is discharged and adjusted while supplying the pressure oil. It can be carried out. Accordingly, since oil is not excessively discharged, the frequency of driving the discharge solenoid valve 10 can be reduced, and as a result, energy consumption can be reduced.

  The present invention is not limited to the above-described configuration, and the hydraulic control target may be a brake hydraulic control device, or may be a hydraulic control device used for shift control of a continuously variable transmission in a conventional vehicle. Further, in the configuration example described above, the solenoid valves 4 and 10 have been exemplified by poppet type solenoid valves, but are not limited thereto, and may be spool type solenoid valves. Furthermore, since it is only necessary to open and close each valve, the valve is not limited to a solenoid valve, and may be a hydraulically driven valve. The present invention can be applied to various hydraulic control devices such as aircraft, ships, and industrial machines.

  DESCRIPTION OF SYMBOLS 1 ... Oil pump, 2 ... Oil pan, 4 ... Supply solenoid valve, 5 ... Accumulator, 7 ... Clutch, 8 ... Cylinder, 10 ... Discharge solenoid valve

Claims (3)

A hydraulic pressure supply means capable of selectively switching between a state in which pressure oil is supplied from the hydraulic pressure source to the actuator and a state in which the supply is stopped, and a state in which the pressure oil of the actuator is discharged and a state in which the discharge is stopped are selectively selected. In the hydraulic control device provided with the hydraulic discharge means switched to
With each of the hydraulic pressure supply means and the hydraulic pressure discharge means stopped, pressure oil is received from the actuator and accumulated to reduce the hydraulic pressure of the actuator, and the accumulated hydraulic pressure is supplied to the actuator. Thus, a hydraulic control means configured to increase the hydraulic pressure of the actuator communicates with the actuator.   The hydraulic pressure control means increases the volume of the hydraulic chamber to accumulate the hydraulic pressure of the actuator to reduce the hydraulic pressure of the actuator, and decreases the volume of the hydraulic chamber to supply the hydraulic pressure accumulated to the actuator. 2. The hydraulic control apparatus according to claim 1, wherein the hydraulic pressure of the actuator is configured to be increased.   The hydraulic control apparatus according to claim 1 or 2, wherein the hydraulic control means includes a cylinder and a piston that slides within the cylinder.

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