JP2010156428A - Control device of flow rate control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately presume a null point where a flow rate of hydraulic oil from a supply source to a destination and a flow rate of the hydraulic oil from the supply source to a discharge passage substantially become zero, according to change in temperature and change with the passage of time. <P>SOLUTION: An ECU executes a program including steps of: (S108) starting measurement when a pump is stopping (YES in S100), when an actuator is not driving (NO in S102), while measurement of a lowering time is permitted (S104), and when accumulative pressure is not more than a predetermined value A (YES in S106); (S112) carrying out correction of the null point from the measured time when the accumulative pressure is not more than a predetermined value B (YES in S110); and (S114) prohibiting the measurement of the lowering time. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to control of a flow rate control valve, and more particularly to estimation of a null point at which the flow rate from a supply source of hydraulic fluid to a supply destination and the flow rate from the supply destination of hydraulic fluid to a discharge path are substantially zero.

  Conventionally, a flow control valve is used in a hydraulic circuit of a transmission mounted on a vehicle, etc., and supplies hydraulic oil from a hydraulic oil supply source to a supply destination to increase hydraulic pressure, or operates from a hydraulic oil supply destination. The hydraulic circuit is activated by discharging the oil and reducing the hydraulic pressure. In the case of controlling the flow control valve operating in this way, the position where the supply amount of hydraulic oil to the supply destination of hydraulic oil and the discharge amount from the supply destination are substantially zero (hereinafter referred to as a null point). However, if there is a deviation between the design value and the actual value, the control accuracy of the flow control valve may deteriorate.

  In view of such a problem, for example, Japanese Patent Laid-Open No. 10-31416 (Patent Document 1) discloses a belt-type continuously variable that can ensure good shift control and drivability without making the driver feel uncomfortable. A transmission control device for a transmission is disclosed. The belt-type continuously variable transmission control device includes an input / output pulley whose contact pulley width of the belt is variably controlled by hydraulic pressure, a piston chamber formed in the input / output pulley and driven in a direction to reduce the pulley width, Shift control that supplies and discharges hydraulic oil to the piston chamber of the input pulley according to the amount of communication between the line pressure port or the drain port and the line pressure supply means for supplying a predetermined line pressure to the piston chamber of the output pulley A shift control device for a belt-type continuously variable transmission, comprising: a valve; an actuator that drives the shift control valve; and a shift control means that drives the actuator based on an operation amount calculated in accordance with a driving state of the vehicle. The input pulley pressure detecting means for detecting the hydraulic oil pressure in the piston chamber of the input pulley, and the flow rate characteristic of the shift control valve are diagnosed based on the detection result of the input pulley pressure detecting means. A quantity characteristic diagnosis means and a flow characteristic correction means for correcting the flow characteristic of the flow control valve are provided, and the shift control valve is forcibly driven when the hydraulic pressure is generated and the belt and the input / output pulley are stopped. Thus, the flow rate characteristic diagnosis and the flow rate characteristic correction are performed.

According to the shift control device for a belt-type continuously variable transmission disclosed in the above-mentioned publication, the neutral “design value” and the “design value” and “ Even if a deviation occurs in the `` actual value '', the amount of deviation is diagnosed and corrected so that unintentional shifts and shift response delays can be ensured from when the ignition switch is turned on until running for a while Therefore, it is possible to ensure good shift control and drivability without giving the driver a sense of incongruity.
Japanese Patent Laid-Open No. 10-311416

  By the way, the null point in the flow rate control valve may fluctuate due to a change in hydraulic oil over time, a temperature change, or the like. Therefore, it is desirable to increase the learning frequency of null points.

  However, learning of the null point is accompanied by supply and discharge of hydraulic oil to the supply destination. Therefore, there is a problem that learning cannot be performed to prevent an unintended shift operation while the vehicle is traveling, the learning frequency is low, and the control accuracy of the flow control valve cannot be improved.

  In the shift control device for a belt-type continuously variable transmission disclosed in the above-mentioned publication, correction is made only when the hydraulic pressure is being generated and the belt and pulley are stopped. In order to improve the learning, it is necessary to further increase the learning frequency.

  The present invention has been made in order to solve the above-described problems. The purpose of the present invention is to substantially reduce the flow rate from the supply source of hydraulic fluid to the supply destination and the flow rate from the supply destination of hydraulic fluid to the discharge path. It is an object of the present invention to provide a control device for a flow rate control valve that accurately estimates a null point that becomes zero corresponding to a temperature change and a change with time.

  In the control device for the flow rate control valve according to the first aspect of the invention, the flow rate control valve is connected to the valve, the first port that houses the valve and is connected to the hydraulic oil supply source, and the hydraulic oil discharge passage A second body port, a valve body provided with a third port connected to the hydraulic fluid supply destination, one of the first port and the second port according to the input of the command value, and the first port A drive unit that communicates with the three ports and changes the position of the valve so as to shut off the other port and the third port. The control device includes a detecting means for detecting a leakage amount of the hydraulic oil in a gap between the valve and the inside of the valve body, which is caused by a pressure difference of the hydraulic oil between the ports when the drive unit is not in operation. Corresponding to the null point where the amount of hydraulic oil supplied from the supplier to the supplier and the amount of hydraulic oil discharged from the supplier to the hydraulic oil discharge path are substantially zero based on the leak amount detected by Estimating means for estimating a command value to be executed.

  According to the first invention, at the null point, the amount of hydraulic fluid leaked from the first port to the third port is substantially the same as the amount of hydraulic fluid leaked from the third port to the second port. The supply of hydraulic oil from the supply source to the supply destination and the discharge of hydraulic oil from the supply destination to the hydraulic oil discharge path are substantially zero. Such a mode of leakage of hydraulic oil is the same even when the drive unit is not operating, and has a correlation. Therefore, when the drive unit is not in operation, the amount of hydraulic oil leakage in the gap between the valve and the inside of the valve body is detected based on the pressure difference of the hydraulic oil between the ports. The amount of leakage at the null point corresponding to can be estimated. As a result, the position of the null point can be estimated with high accuracy. Further, when the command value corresponding to the null point is estimated under a predetermined condition every time the drive unit is not operated, the learning frequency can be increased. Therefore, a flow rate control valve that accurately estimates the null point at which the flow rate from the hydraulic oil supply source to the supply destination and the flow rate from the hydraulic oil supply destination to the discharge becomes substantially zero corresponding to temperature changes and changes with time. A control device can be provided.

  In the control device for the flow rate control valve according to the second invention, in addition to the configuration of the first invention, the supply source includes a pump that generates hydraulic pressure and an accumulator that accumulates the hydraulic pressure generated by the pump. The detecting means detects the amount of hydraulic fluid leakage based on the amount of change in hydraulic pressure in the accumulator.

  According to the second invention, when the leakage amount increases in the gap between the valve and the inside of the valve body, the degree of decrease in the accumulator oil pressure increases, and when the leakage amount decreases, the degree of decrease in the accumulator oil pressure also decreases. . That is, it can be said that the degree of decrease in the hydraulic pressure of the accumulator corresponds to the leakage amount. Therefore, the leak amount can be detected with high accuracy by detecting the leak amount based on the change amount of the hydraulic pressure in the accumulator.

  In the control device for the flow rate control valve according to the third aspect of the invention, in addition to the configuration of the second aspect of the invention, the detecting means is configured to reduce the time until the hydraulic pressure in the accumulator decreases from the first hydraulic pressure to the second hydraulic pressure. Based on this, the amount of hydraulic oil leakage is detected.

  According to the third aspect of the invention, the relationship between the reduction amount of the hydraulic pressure and the reduction time can be specified by the reduction time until the hydraulic pressure decreases from the first hydraulic pressure to the second hydraulic pressure. Therefore, it is possible to detect with high accuracy the amount of leakage of hydraulic oil corresponding to the degree of decrease in hydraulic pressure.

  In the control device for the flow rate control valve according to the fourth invention, in addition to the configuration of any one of the first to third inventions, the valve is slidably housed inside the valve body. The third port is provided between the first port and the second port in the valve sliding direction. The initial position of the valve when the drive unit is not in operation is a position where the second port and the third port communicate with each other and the first port and the third port are blocked. The estimation means estimates that the command value corresponding to the null point becomes a value closer to the initial position than the valve drive position during operation of the drive unit as the leakage amount increases, and corresponds to the null point as the leakage amount decreases. The command value to be estimated is estimated to be a value on the drive position side from the initial position.

  According to the fourth aspect of the invention, the command value corresponding to the null point is estimated to be a value closer to the initial position than the drive position as the leakage amount increases, and the command value corresponding to the null point is initialized as the leakage amount decreases. By estimating so as to be a value closer to the drive position than the position, the command value corresponding to the null point can be estimated with high accuracy.

  In the control device for a flow control valve according to the fifth invention, in addition to the configuration of any one of the first to fourth inventions, the supply destination of the hydraulic oil is provided in the transmission of the vehicle, and the speed change operation of the transmission It is an actuator which performs.

  According to the fifth invention, the command value corresponding to the null point is estimated with high accuracy by applying the present invention to the flow rate control valve for supplying and discharging the hydraulic oil to and from the actuator that performs the speed change operation of the transmission. Therefore, the accuracy of the shift control can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  A vehicle equipped with a transmission to which a flow rate control valve according to the present embodiment is applied will be described with reference to FIG. The vehicle travels when the driving force generated by the engine 100 is transmitted to the wheels 404 via the clutch 200, the transmission 300, the differential gear 400, and the drive shaft 402. Engine 100, clutch 200, and transmission 300 are controlled by an ECU (Electronic Control Unit) 500. The control device for the flow control valve according to the present embodiment is realized by a program executed in ECU 500, for example.

  Clutch 200 is connected to crankshaft 518 of engine 100. Clutch output shaft 202 is connected to input shaft 302 of transmission 300 via spline 310.

  The transmission 300 is composed of a constantly meshing gear train. The gear stage in the transmission 300 is selected by sliding the shift fork shaft by the actuator 304. In the present embodiment, the actuator 304 is operated by hydraulic pressure.

  The ECU 500 includes an accelerator opening sensor 502, a brake stroke sensor 504, a position sensor 506, a crank position sensor 510 provided opposite to the outer periphery of the timing rotor 508, an input shaft rotational speed sensor 512, an output shaft rotational speed sensor 514, A signal is transmitted from the wheel speed sensor 516.

  The accelerator opening sensor 502 detects the accelerator opening of the accelerator pedal. The brake stroke sensor 504 detects the operation amount (depression amount) of the brake pedal. The position sensor 506 detects the shift position of the shift lever.

  The crank position sensor 510 detects the engine speed NE. Specifically, ECU 500 detects engine speed NE based on the time per pulse of the pulse signal transmitted from crank position sensor 510.

  The rotational speed NI of the input shaft 302 of the transmission 300 is detected by the input shaft rotational speed sensor 512. Specifically, ECU 500 detects input shaft rotational speed NI based on the time per pulse of the pulse signal transmitted from input shaft rotational speed sensor 512.

  An output shaft rotation speed sensor 514 detects the rotation speed of the output shaft 306 of the transmission 300. Specifically, ECU 500 detects the output shaft rotational speed based on the time per pulse of the pulse signal transmitted from output shaft rotational speed sensor 514.

  The rotational speed NO of the wheel 404 is detected by the wheel speed sensor 516. Specifically, ECU 500 detects the rotational speed NO of wheel 404 based on the time per pulse of the pulse signal transmitted from wheel speed sensor 516. ECU 500 also calculates the vehicle speed from the rotational speed NO of wheel 404. Further, ECU 500 calculates acceleration (including deceleration) from the vehicle speed.

  ECU 500 performs arithmetic processing based on signals transmitted from these sensors, a program stored in a memory (not shown), a map, a shift line, and the like. Thus, ECU 500 controls engine 100, clutch 200, and transmission 300. In the present embodiment, ECU 500 executes shift control according to the shift line.

  Actuator 304 includes an actuator (1) for selecting a shift fork and an actuator (2) for moving (shifting) the shift fork. In this embodiment, the shift fork (1) corresponding to the first speed (1st) and the second speed (2nd), the shift fork corresponding to the third speed (3rd) and the fourth speed (4th) ( 2), and a shift fork (3) corresponding to fifth speed (5th) and reverse (Rev).

  Actuator (1) is a member for selecting and moving a shift fork so as to select a shift fork corresponding to a shift destination among shift forks (1) to (3) (hereinafter referred to as a shift sleeve). Move. The actuator (2) moves the shift sleeve so that the selected shift fork is in a position corresponding to the shift destination.

  For example, when the first speed is selected according to the shift line or the driver's instruction, the actuator (1) moves the shift sleeve so as to select the shift fork (1), and then the actuator (2) moves the shift fork. The shift sleeve is moved so that (1) is at a position corresponding to the shift destination. In the following description, the direction in which the shift sleeve is moved so as to select the shift fork is described as a select direction, and the direction in which the selected shift fork is moved to a position corresponding to the shift destination is described as a shift direction.

  For example, ECU 500 recognizes the movement position of the shift sleeve in the select direction based on the operation amount of actuator (1), and recognizes the movement position of the shift sleeve in the shift direction based on the operation amount of actuator (2). ECU 500 may detect the operation amounts of actuators (1) and (2) using a sensor or the like.

  Therefore, ECU 500 recognizes the position of the shift sleeve (circle in FIG. 2) with respect to the movable range (shift gate) of the shift sleeve as shown in FIG. The selection direction shown in FIG. 2 is a direction for selecting the shift fork, and the shift direction shown in FIG. 2 is a direction for moving the selected shift fork.

  For example, ECU 500 uses actuator 304 to move the shift sleeve in the order of 2nd speed and 3rd speed from the position corresponding to 1st speed along the movement path preset in the shift gate according to the shift line. Shift operation is performed. These speed change operations are performed by setting the clutch 200 in the power cut-off state and driving the actuator 304, and after the speed change operation, the clutch 200 is again set in the power transmission state and completed. Further, when the vehicle is stopped, the vehicle is returned to the neutral position (dotted circle in FIG. 2).

  The actuator 304 operates when hydraulic fluid is supplied from the hydraulic circuit or when hydraulic fluid supplied to the actuator 304 is discharged. As shown in FIG. 3, in the present embodiment, the hydraulic circuit includes a flow control valve 550, an accumulator 552, a pump 554, an actuator 304, and an accumulator pressure sensor 572.

  The pump 554 is a hydraulic pressure source that generates hydraulic pressure. Specifically, the pump 554 is an electric pump that generates hydraulic pressure by pumping the hydraulic oil stored in the oil pan 560 and pumping the hydraulic oil pumped to the oil passage 556. Pump 554 operates based on a control signal from ECU 500. The pump 554 is connected to the flow control valve 550 via an oil passage 556.

  An accumulator 552 is provided in the middle of the oil passage 556. The accumulator 552 accumulates the hydraulic pressure generated by the pump 554. Therefore, the hydraulic pressure accumulated by the accumulator 552 is supplied to the flow control valve 550.

  The accumulation pressure sensor 572 detects the pressure in the oil passage 556, that is, the accumulation pressure. Accumulation pressure sensor 572 transmits a signal indicating the detected accumulation pressure to ECU 500. The oil temperature sensor 574 detects the temperature of the hydraulic oil flowing through the oil passage 556. Oil temperature sensor 574 transmits a signal indicating the detected temperature of hydraulic oil to ECU 500.

  The flow control valve 550 is an electromagnetically driven valve such as a solenoid valve having a drive unit 610 that is driven based on a control signal from the ECU 500. The flow control valve 550 is connected to the actuator 304 via an oil passage 562. In the present embodiment, as described above, the actuator (1) corresponding to the select direction and the flow control valve connected to the actuator (1), and the actuator (2) and actuator (2) corresponding to the shift direction. However, in the following description, the structure and operation of the flow control valve and the actuator corresponding to either the selection direction or the shift direction will be described. The configuration of the other flow control valve and the actuator is the same in structure and operation except for the movement direction, and detailed description will not be repeated. In addition, the actuator (1) or (2) is described as an actuator 304 for convenience of explanation.

  The flow control valve 550 includes an applied state in which hydraulic fluid is supplied from the supply source to the actuator 304 in response to a control signal from the ECU 500, a drain state in which hydraulic fluid is discharged from the actuator 304 to the hydraulic oil discharge path, and an actuator from the supply source to the actuator. The flow rate of the hydraulic oil supplied to 304 and the flow rate of the hydraulic oil discharged from the actuator 304 to the hydraulic oil discharge path are substantially zero (hereinafter referred to as a state corresponding to the null point). It will be in either state.

  Actuator 304 includes a piston 566 connected to a moving object, an oil chamber 568 provided on the left side of FIG. 3 with respect to piston 566, and an oil chamber 570 provided on the right side of FIG. 3 with respect to piston 566. . The piston 566 moves when the hydraulic oil is supplied to the oil chamber 570 from the flow control valve 550 or the hydraulic oil is discharged from the oil chamber 570. Due to the movement of the piston 566, the moving object moves. In the present embodiment, the moving object is the above-described shift sleeve.

  For example, in the applied state where hydraulic oil is supplied from the flow control valve 550 to the oil chamber 570, the hydraulic pressure in the oil chamber 570 increases. When the force acting on the piston 566 based on the oil pressure in the oil chamber 570 in the left direction in FIG. 3 exceeds the reaction force from the piston 566 due to the increase in the oil pressure in the oil chamber 570, the piston 566 is moved to the left side in FIG. Will move in the direction of.

  When the hydraulic oil supplied to the oil chamber 570 is drained, the hydraulic pressure in the oil chamber 570 decreases. When the force acting on the piston 566 based on the oil pressure in the oil chamber 570 in the left direction of FIG. 3 falls below the reaction force from the piston 566 due to the decrease in the oil pressure in the oil chamber 570, the piston 566 Will move in the direction of.

  And when it will be in the state corresponding to the null point where neither supply of hydraulic oil to oil chamber 570 nor discharge of hydraulic oil from oil chamber 570 is performed, the oil pressure in oil chamber 570 does not change. When the force for moving the piston 566 to the left in FIG. 3 and the reaction force from the piston 566 are balanced, the position of the piston 566 stops.

  In the present embodiment, the reaction force from the piston 566 side connects the oil chamber on the left side of the piston 566 in FIG. 3 and the oil passage 556 via the oil passage 558 as shown in FIG. Although described based on the pressure of the left oil chamber in FIG. 3 and the pressure receiving area on the left side of FIG. 3 in the piston 566, it may be based on an elastic member such as a spring in addition to or instead of this.

  ECU 500 transmits a control signal to flow control valve 550 to operate actuator 304 as described above. The operation state of the flow control valve 550 is changed by a current supplied in accordance with a control signal from the ECU 500, and the flow rate of the hydraulic oil to the actuator 304 and the hydraulic oil from the actuator 304 are changed by the change of the state of the flow control valve 550. The flow rate changes.

  FIG. 4 shows the relationship between the current supplied to the flow control valve 550 and the flow rate of the hydraulic oil. As shown by the solid line in FIG. 4, when the current supplied to the flow control valve 550 has a current value corresponding to the null point, the flow control valve 550 is in a state corresponding to the null point. No hydraulic oil is supplied and no hydraulic oil is discharged from the actuator 304, and the flow rate Q becomes substantially zero.

  When the current supplied to the flow control valve 550 increases from the current value corresponding to the null point, the flow control valve 550 changes from the state corresponding to the null point to the applied state. As the flow rate control valve 550 changes from the state corresponding to the null point to the applied state side, the flow rate of hydraulic oil supplied to the actuator 304 from the accumulator 552 and the pump 554 as the supply source via the oil passages 556 and 562 increases. I will do it.

  On the other hand, when the current supplied to the flow control valve 550 decreases from the current value corresponding to the null point, the flow control valve 550 changes from the state corresponding to the null point to the drain state side. As the flow rate control valve 550 changes from the state corresponding to the null point to the drain side, the flow rate of hydraulic oil discharged from the supply destination actuator 304 to the oil pan 560 via the oil path 562 and the hydraulic oil discharge path 564 Will increase.

  In the flow control valve 550 having the above-described configuration, the relationship between the flow rate and the current may be in a state as indicated by the broken line in FIG. Such a phenomenon occurs due to factors such as a change in the viscosity of the hydraulic oil due to a change in temperature of the hydraulic oil or a change over time. Since the position corresponding to the null point in the flow rate control valve 550 varies, the current value corresponding to the null point also varies.

  Therefore, even if a current corresponding to the null point recognized by ECU 500 (the null point based on the solid line in FIG. 4) is supplied, the relationship between the actual flow rate and the current is as shown by the broken line in FIG. The valve 550 may not be accurately controlled to a state corresponding to the null point. As a result, the actuator 304 may not be operated with high accuracy. Therefore, the position control of the piston 566 cannot be performed with high accuracy.

  Therefore, the present embodiment is characterized in that ECU 500 estimates a command value (current value) corresponding to the null point based on the amount of hydraulic oil leakage when flow control valve 550 is not operated.

  As shown in FIG. 5, the flow rate control valve 550 includes a valve 600, an apply port 604 that houses the valve 600 and is connected to a pump 554 and an accumulator 552 that are hydraulic oil supply sources, and a hydraulic oil discharge path. A valve body 602 provided with a drain port 606 connected to 564 and a control port 608 connected to the actuator 304 to which hydraulic oil is supplied, and an apply port 604 and a drain port 606 in response to input of a command value. And a drive unit 610 that changes the position of the valve 600 so as to connect one of the control port 608 and the other to the control port 608. The valve body 602 houses the valve 600 in a slidable manner. In the present embodiment, the control port 608 is provided between the apply port 604 and the drain port 606 in the sliding direction of the valve 600. Further, the valve 600 is fixed to the spool 612. The drive unit 610 changes the position of the valve 600 by driving a spool 612 that fixes the valve 600 using a solenoid.

  When the current corresponding to the null point is supplied to the flow control valve 550, the flow control valve 550 is in the state shown in FIG. At this time, the valve 600 shuts off between the apply port 604 and the control port 608 and moves to a position to shut off between the drain port 606 and the control port 608. In this state, since the hydraulic pressure supplied to the actuator 304 is in a constant state, the position of the piston 566 of the actuator 304 is held.

  At this time, an apply pressure (hereinafter also referred to as an accumulator pressure) Pa on the apply port 604 side is larger than a control pressure Pc on the control port 608 side. Therefore, hydraulic fluid leaks from the apply port 604 side to the control port 608 side based on the differential pressure Pa−Pc between the apply pressure Pa and the control pressure Pc.

  Further, the control pressure Pc is higher than the drain pressure (atmospheric pressure) Pd on the drain port 606 side. Therefore, hydraulic fluid leaks from the control port 608 side to the drain port 606 side based on the differential pressure Pc−Pd between the control pressure Pc and the drain pressure Pd.

  When the valve 600 is in a position corresponding to the null point, the amount of hydraulic oil leaked from the apply port 604 side to the control port 608 side and the amount of hydraulic oil leaked from the control port 608 side to the drain port 606 side Are equal to each other.

  When the supply of current to the flow control valve 550 is stopped (energization cut), the flow control valve 550 enters the state shown in FIG. 6 (during non-operation). At this time, the valve 600 communicates between the drain port 606 and the control port 608 and moves to an initial position where the gap between the apply port 604 and the control port 608 is blocked. In this state, the hydraulic oil supplied to the actuator 304 is discharged from the drain port 606. Therefore, the control pressure Pc and the drain pressure are equal.

  At this time, the apply pressure Pa is larger than the drain pressure Pd. Therefore, hydraulic fluid leaks from the apply port 604 side to the control port 608 side based on the differential pressure Pa−Pd between the apply pressure Pa and the drain pressure Pd.

  That is, both when the energization is cut and when the flow control valve 550 is in a state corresponding to the null point, based on the differential pressure between the ports (particularly, the differential pressure between the apply pressure Pa and the drain pressure Pd). The hydraulic oil leaks when the hydraulic oil flows through the gap between the valve and the inside of the valve body 602. The mode of hydraulic oil leakage is the same. Therefore, there is a correlation between the leakage amount of hydraulic oil at the time of energization cut and the leakage amount in a state corresponding to the null point.

  In this embodiment, paying attention to this correlation, a leakage amount at the time of energization cut is detected, and a current value in a state corresponding to the null point is estimated based on the detected leakage amount.

  FIG. 7 shows a functional block diagram of ECU 500 that is a control device for the flow control valve according to the present embodiment. The ECU 500 includes a pump stop determination unit 530, an actuator drive determination unit 532, a measurement permission determination unit 534, an accumulation pressure determination unit (1) 536, a measurement time reset unit 538, a decrease time measurement unit 540, and an accumulation pressure. It includes a determination unit (2) 542, a null point correction unit 544, and a decrease time measurement prohibition unit 546.

  The pump stop determination unit 530 determines whether or not the pump 554 is stopped. The pump stop determination unit 530 determines whether the pump 554 is stopped based on an instruction state from the ECU 500 to the pump 554. For example, the pump stop determination unit 530 determines that the pump 554 is operating when a control signal is output from the ECU 500 to the pump 554, and the control signal is output from the ECU 500 to the pump 554. If not, it is determined that the pump 554 is stopped.

  The pump stop determination unit 530 may turn on a pump stop determination flag when the pump 554 is stopped, for example.

  The actuator drive determination unit 532 determines whether or not the actuator 304 is being driven. The actuator drive determination unit 532 determines whether the actuator 304 is being driven based on the operating state of the flow control valve 550. The actuator drive determination unit 532 determines that the actuator 304 is being driven when current is supplied to the flow control valve 550.

  Note that the actuator drive determination unit 532 may turn on the drive determination flag when determining that the actuator 304 is being driven, for example.

  The measurement permission determination unit 534 determines whether or not measurement of the accumulator pressure drop time is permitted. The measurement permission determination unit 534 determines that measurement of the accumulation pressure drop time is permitted when the pump 554 is driven.

  Note that the measurement permission determination unit 534 may determine that the measurement of the accumulator pressure drop time is permitted when the pump stop determination flag is off, and turn on the permission determination flag.

  The accumulator pressure determination unit (1) 536 determines whether or not the accumulator pressure is equal to or less than a predetermined value A when measurement of the accumulator pressure drop time is permitted. The predetermined value A is a value set based on the accumulator pressure (pump drive stop pressure) at which the pump 554 is stopped after the pump 554 is driven to start increasing the accumulator pressure, and is adapted by experiments or the like. Is done. The predetermined value A is a value that is at least equal to or lower than the pump drive stop pressure.

  The accumulator pressure determination unit (1) 536 performs the accumulator pressure determination when the permission determination flag is on, and the accumulator pressure determination is performed when the accumulator pressure is equal to or less than a predetermined value A, for example. The flag (1) may be turned on.

  The measurement time reset unit 538 resets the measurement time to an initial value (for example, zero) when it is determined that the accumulator pressure is not equal to or less than a predetermined value A. Note that the measurement time resetting unit 538 resets the measurement time to the initial value when the permission determination flag is on and the accumulation pressure determination flag (1) is off, for example.

  The decrease time measuring unit 540 starts measuring the decrease time of the accumulator pressure when the accumulator pressure is equal to or less than a predetermined value A. For example, when the accumulation pressure determination flag (1) is turned on from off, the decrease time measuring unit 540 may start measuring the decrease time of the accumulation pressure.

  The accumulation pressure determination unit (2) 542 determines whether the accumulation pressure is equal to or less than a predetermined value B. The predetermined value B is a value that is at least smaller than the predetermined value A and is set based on the accumulator pressure (pump drive start pressure) at which the pump 554 starts to be driven. The predetermined value B is at least a value equal to or higher than the pump drive start pressure, and is adapted by experiment or the like.

  The accumulator pressure determination unit (2) 542 determines the accumulator pressure when the measurement of the accumulative pressure drop time is started, and the accumulator pressure accumulator is determined when the accumulator pressure is equal to or less than a predetermined value B. The pressure determination flag (2) may be turned on. Further, the accumulation pressure determination flag (1) and the accumulation determination flag (2) may both be turned off when measurement of the decrease time of the accumulation pressure is prohibited.

  The null point correction unit 544 calculates a leakage amount based on the measured decrease time of the accumulation pressure. The relationship between the reduction time of the accumulator pressure and the leakage amount may be defined in advance using a map, a mathematical formula, a table, or the like. The null point correction unit 544 calculates a current value corresponding to the null point based on the calculated leakage amount using a map or the like.

  The map used when calculating the current value corresponding to the null point based on the leakage amount, for example, as shown in FIG. 8, the horizontal axis is the leakage amount and the vertical axis is the current value corresponding to the null point. It is a map. Further, in the map of FIG. 8, the relationship between the leakage amount according to the temperature of the hydraulic oil and the current value corresponding to the null point is set. For example, as shown in FIG. 8, the relationship between the leakage amount corresponding to the temperature ACC (1), the temperature ACC (2), and the temperature ACC (3) of the hydraulic oil and the current value corresponding to the null point is set. . The temperature ACC (1) is higher than the temperature ACC (2) and the temperature ACC (3), and the temperature ACC (2) is higher than the temperature ACC (3).

  That is, the map shown in FIG. 8 is set so that the current value corresponding to the null point decreases as the leakage amount increases (the null point is corrected to the drain state side), and the leakage point corresponds to the null point. The current value is set to be large (the null point is corrected on the apply side). Moreover, it sets so that the electric current value corresponding to the null point with respect to the same leakage amount may become large, so that the temperature of hydraulic fluid becomes high (a null point is correct | amended on the apply side).

  For example, when the leakage amount calculated based on the accumulation pressure reduction time is the leakage amount q (1) and the temperature of the hydraulic oil is the temperature ACC (1), the null point correction unit 544 The current value A (1) is calculated as the current value corresponding to the null point using the map corresponding to the operation ACC (1) in FIG. The null point correction unit 544 corrects the relationship between the current and the flow rate shown in FIG. 4 based on the current value A (1) corresponding to the calculated null point. Specifically, the null point correction unit 544 uses the difference between the current value corresponding to the previous null point and the current value corresponding to the current null point as a correction value to determine the relationship between the current and the flow rate shown in FIG. to correct.

  In addition, when the temperature of hydraulic oil is not any of temperature ACC (1), temperature ACC (2), and temperature ACC (3), it corresponds to temperature ACC (1), temperature ACC (2), and temperature ACC (3). What is necessary is just to calculate the electric current value corresponding to the null point according to the temperature of hydraulic fluid by linear interpolation etc. using the map to do.

  When the null point correction is executed, the decrease time measurement prohibition unit 546 prohibits the measurement of the decrease time until the measurement permission determination unit 534 permits the measurement of the decrease time of the accumulator pressure again. For example, when the null point correction unit 544 corrects the null point, the decrease time measurement prohibition unit 546 may turn off the permission determination flag turned on by the measurement permission determination unit 534.

  In the present embodiment, the pump stop determination unit 530, the actuator drive determination unit 532, the measurement permission determination unit 534, the accumulation pressure determination unit (1) 536, the measurement time reset unit 538, and the decrease time measurement unit 540 The accumulator pressure determination unit (2) 542, the null point correction unit 544, and the decrease time measurement prohibition unit 546 are all realized as software executed by the CPU of the ECU executing a program stored in the memory. Although described as functioning, it may be realized by hardware. Such a program is recorded on a storage medium and mounted on the vehicle.

  With reference to FIG. 9, a control structure of a program executed by ECU 500 which is the control device for the flow control valve according to the present embodiment will be described.

  In step (hereinafter, step is referred to as S) 100, ECU 500 determines whether pump 554 is stopped or not. If pump 554 is stopped (YES in S100), the process proceeds to S102. If not (NO in S100), the process proceeds to S118.

  In S102, ECU 500 determines whether or not actuator 304 is being driven. If actuator 304 is being driven (YES in S102), the process proceeds to S114. If not (NO in S102), the process proceeds to S104.

  In S104, ECU 500 determines whether or not measurement of the accumulation pressure reduction time is being permitted. If the permission determination flag is on, ECU 500 determines that measurement of the reduction time of the accumulator pressure is being permitted. If measurement of the decrease time of the accumulation pressure is being permitted (YES in S104), the process proceeds to S106. Otherwise (NO in S104), this process ends.

  In S106, ECU 500 determines whether or not the accumulator pressure is equal to or less than a predetermined value A. If the accumulation pressure is equal to or lower than a predetermined value A (YES in S106), the process proceeds to S108. If not (NO in S106), the process proceeds to S116.

  In S108, ECU 500 starts measuring the decrease time of the accumulator pressure. In S110, ECU 500 determines whether or not the accumulator pressure is equal to or less than a predetermined value B. If the accumulator pressure is equal to or lower than a predetermined value B (YES in S110), the process proceeds to S112. Otherwise (NO in S110), this process ends.

  In step S112, the ECU 500 corrects the null point based on the measured decrease time, that is, the time required for the accumulator pressure to decrease from the predetermined value A to the predetermined value B. In S114, ECU 500 prohibits the measurement of the decrease time of the accumulation pressure and turns off the permission determination flag. In S116, ECU 500 clears the measurement time and resets it to an initial value (for example, zero). In S118, ECU 500 permits measurement of the accumulation pressure drop time, and turns on the permission determination flag.

  The operation of ECU 500 that is the flow control valve according to the present embodiment based on the structure and flowchart as described above will be described with reference to FIG.

  When the accumulator pressure falls below a predetermined value B at time T (0), the pump 554 is driven to increase the accumulator pressure. While the pump 554 is being driven (NO in S100), measurement of the accumulator pressure drop time is permitted (S118).

  When the accumulator pressure reaches the drive stop pressure at time T (1), drive of pump 554 is stopped (YES in S100). Here, if actuator 304 is not driven (YES in S102), the measurement of the accumulation pressure drop time is permitted (YES in S104), so the accumulator pressure is equal to or less than a predetermined value A. It is determined whether or not (S106). If the accumulator pressure is not less than or equal to predetermined value A (NO in S106), the previous measurement time is cleared (S116). On the other hand, when the accumulator pressure is equal to or lower than a predetermined value A at time T (2) (YES in S106), measurement is started (S108).

  The measurement is continued until the accumulator pressure becomes equal to or lower than a predetermined value B. When the accumulator pressure becomes equal to or lower than the predetermined value B at time T (3) (YES in S110), the measurement is performed until then. The null point is corrected based on the time T (3) -T (2) that has been made (S112). That is, the leakage amount is calculated based on the measured time T (3) -T (2), the current value corresponding to the null point is estimated based on the calculated leakage amount, and based on the estimated current value. Thus, the relationship between the flow rate and the current shown in FIG. 4 is corrected. Detailed description is as described above and will not be repeated. After the null point is corrected, the accumulator pressure drop time is prohibited (S114).

  As indicated by the one-dot chain line in FIG. 10, the accumulating pressure decrease time becomes shorter as the leakage amount becomes larger, and as shown by the two-dot chain line in FIG. 10, the accumulating pressure lowering time becomes longer as the leakage amount becomes smaller.

  As described above, according to the control device for a flow control valve according to the present embodiment, when the drive unit is not in operation, the operation in the gap between the valve and the inside of the valve body is caused by the pressure difference of the hydraulic oil between the ports. By detecting the amount of oil leakage, it is possible to estimate the amount of leakage at the null point corresponding to the deterioration of hydraulic oil over time, temperature change, and the like. As a result, the position of the null point can be estimated with high accuracy. Further, if the command value corresponding to the null point is estimated under predetermined conditions (pump stop, actuator non-operation and measurement permission) every time the drive unit is inactive, the learning frequency can be increased. . Therefore, a flow rate control valve that accurately estimates the null point at which the flow rate from the hydraulic oil supply source to the supply destination and the flow rate from the hydraulic oil supply destination to the discharge becomes substantially zero corresponding to temperature changes and changes with time. A control device can be provided.

  Further, when the leakage amount increases in the gap between the valve and the inside of the valve body, the degree of decrease in the accumulator oil pressure increases, and when the leakage amount decreases, the degree of decrease in the accumulator oil pressure also decreases. That is, it can be said that the degree of decrease in the hydraulic pressure of the accumulator corresponds to the leakage amount. Therefore, the leak amount can be detected with high accuracy by detecting the leak amount based on the change amount of the hydraulic pressure in the accumulator.

  Furthermore, the relationship between the amount of decrease in hydraulic pressure and the decrease time can be specified by the decrease time until the accumulator pressure decreases from the predetermined value A to the predetermined value B. Therefore, it is possible to detect with high accuracy the amount of leakage of hydraulic oil corresponding to the degree of decrease in hydraulic pressure.

  The command value corresponding to the null point is estimated to be a value closer to the initial position than the valve drive position during operation of the drive unit as the leakage amount increases, and the command corresponding to the null point as the leakage amount decreases. By estimating the value to be a value closer to the driving position than the initial position, the command value corresponding to the null point can be estimated with high accuracy.

  Further, by applying the present invention to the flow control valve that supplies and discharges hydraulic oil to and from the actuator that performs the speed change operation of the transmission, the command value corresponding to the null point can be estimated with high accuracy. Accuracy can be improved.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a control block which shows the vehicle carrying the transmission with which the flow control valve which concerns on this Embodiment is applied. It is a figure which shows a shift gate. It is a figure which shows a part of structure of the hydraulic circuit containing the flow control valve which concerns on this Embodiment. It is a figure which shows the relationship between the command value (electric current value) with respect to a flow control valve, and the flow volume of the hydraulic fluid in a flow control valve. It is a figure which shows a part of structure of the flow control valve in the state corresponding to a null point. It is a figure which shows a part of structure of the flow control valve at the time of energization cut. It is a functional block diagram of ECU which is a control apparatus of the flow control valve concerning this embodiment. It is a figure which shows the relationship between the amount of hydraulic fluid leaks, and the command value corresponding to a null point. It is a flowchart which shows the control structure of the program performed with ECU which is a control apparatus of the flow control valve concerning this Embodiment. It is a timing chart which shows change of accumulation pressure for explaining operation of ECU which is a control device of a flow control valve concerning this embodiment.

Explanation of symbols

  100 engine, 200 clutch, 202 clutch output shaft, 300 transmission, 302 input shaft, 304 actuator, 306 output shaft, 310 spline, 400 differential gear, 402 drive shaft, 404 wheels, 502 accelerator opening sensor, 504 brake stroke sensor , 506 Position sensor, 508 Timing rotor, 510 Crank position sensor, 512 Input shaft speed sensor, 514 Output shaft speed sensor, 516 Wheel speed sensor, 518 Crankshaft, 530 Pump stop judgment section, 532 Actuator drive judgment section, 534 Measurement permission determination unit, 536, 542 Accumulation pressure determination unit, 538 Measurement time reset unit, 540 Decrease time measurement unit, 544 Null point correction unit, 546 Decrease time Measurement prohibition section, 550 Flow control valve, 552 Accumulator, 554 Pump, 556, 558, 562 Oil passage, 560 Oil pan, 564 Hydraulic oil discharge passage, 566 Piston, 568, 570 Oil chamber, 572 Accumulation pressure sensor, 574 Oil temperature Sensor, 600 valve, 602 valve body, 604 apply port, 606 drain port, 608 control port, 610 drive unit, 612 spool.

Claims (5)

A control device for a flow rate control valve, wherein the flow rate control valve houses a valve, a first port that houses the valve and is connected to a hydraulic oil supply source, and a first port that is connected to a hydraulic oil discharge passage. A valve body provided with two ports and a third port connected to a supply destination of hydraulic oil, one of the first port and the second port according to the input of a command value, and the first A drive unit that communicates with 3 ports and changes the position of the valve so as to shut off the other port and the third port;
The control device includes:
Detecting means for detecting a leakage amount of hydraulic oil in a gap between the valve and the inner side of the valve body caused by a pressure difference of the hydraulic oil between the ports when the drive unit is not operated;
Based on the leakage amount detected by the detection means, the supply amount of hydraulic oil from the supply source to the supply destination and the discharge amount of hydraulic oil from the supply destination to the hydraulic oil discharge path are substantially And a estimator for estimating a command value corresponding to a null point that is zero. The supplier includes a pump that generates hydraulic pressure, and an accumulator that accumulates the hydraulic pressure generated by the pump,
The flow rate control valve control device according to claim 1, wherein the detection unit detects a leakage amount of the hydraulic oil based on a change amount of a hydraulic pressure in the accumulator.   The control of the flow rate control valve according to claim 2, wherein the detection means detects a leakage amount of the hydraulic oil based on a reduction time until the hydraulic pressure in the accumulator decreases from the first hydraulic pressure to the second hydraulic pressure. apparatus. The valve is slidably housed inside the valve body,
The third port is provided between the first port and the second port in the sliding direction of the valve,
The initial position of the valve when the drive unit is not in operation is a position where the second port and the third port communicate with each other and the first port and the third port are blocked.
The estimation means estimates that the command value corresponding to the null point becomes a value closer to the initial position than the valve drive position during operation of the drive unit as the leak amount increases, and the leak amount The flow rate control valve control device according to any one of claims 1 to 3, wherein a command value corresponding to the null point is estimated to be a value closer to the drive position than the initial position as becomes smaller.   5. The flow rate control valve control device according to claim 1, wherein a supply destination of the hydraulic oil is an actuator that is provided in a transmission of a vehicle and performs a shift operation of the transmission.

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