JP2020106056A - Fluid pressure drive device and driving method for flow control valve - Google Patents

Abstract

To prevent a spool from being fixed even in a case that a foreign matter is caught into the spool.SOLUTION: A fluid pressure drive device 1 comprises: a flow control valve 2 which includes a movable part 2a and controls a discharge quantity of a hydraulic fluid in accordance with a position of the movable part 2a; an estimation section 9 which estimates a catching state in any one of a case where the movable part 2a does not reach a movement target position within a predetermined time from timing in which a driving command to move the movable part 2a to the movement target position is issued, and a case where a predetermined moving speed is not achieved when the movable part 2a is moved to the movement target position; and a drive control section 10 by which, after the catching state is estimated, the movable part 2a is driven with greater drive power than drive power of the movable part 2a in a case where the catching state is not estimated, in timing when a drive command of the movable part 2a in a direction reverse to a driving direction of the movable part 2a in a case where the catching state is estimated, is issued.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fluid pressure drive device and a method for driving a flow control valve.

One of the malfunctions of the flow control valve that controls the discharge amount of hydraulic oil is a malfunction that foreign matter is caught in the spool of the flow control valve and the spool is stuck. The spool must reliably seal the hydraulic oil in the neutral position and discharge the hydraulic oil as the spool moves from the neutral position.

JP, 2016-50585, A

However, if foreign matter is mixed in the hydraulic oil in the flow control valve, when the spool is returned to the neutral position from the state where the hydraulic oil is being discharged, the foreign matter is caught in the spool and the spool becomes stuck. It may end up. When the spool is stuck, even if an attempt is made to move the spool again, the spool does not move, so that hydraulic oil cannot be discharged and the original function of the flow control valve cannot be achieved.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluid pressure drive device and a flow control valve drive method that prevent the spool from sticking to the spool even if foreign matter is caught in the spool.

In order to solve the above problems, in one aspect of the present invention, a flow control valve having a movable portion, which controls the discharge amount of the working fluid according to the position of the movable portion,
When the movable portion does not reach the movement target position within a predetermined time from the timing of the drive command for moving the movable portion to the movement target position, and when the movable portion moves to the movement target position, A biting estimation unit that estimates that the vehicle is in a biting state when at least one of the moving speed is not reached, and
When it is not in the jammed state at the timing when a drive command for the movable part in the opposite direction to the driving direction of the movable part when it is in the jammed state is output after it is estimated to be in the jammed state. And a drive control unit that drives the movable unit with a driving force that is larger than the driving force of the movable unit.

A driving force determination unit that determines whether or not the driving force of the movable unit is equal to or greater than a first threshold,
Position deviation for determining whether or not the deviation between the movement target position of the movable portion and the actual position of the movable portion is equal to or greater than a second threshold when the driving force of the movable portion is determined to be equal to or greater than the first threshold value. And a determination unit,
The biting estimation unit may estimate that the movable unit is in the biting state when the position deviation determination unit determines that the deviation is equal to or more than the second threshold value.

The position deviation determination unit determines whether or not the deviation when the movable unit moves in the first movable direction or the second movable direction is equal to or more than the second threshold value based on whether the deviation is positive or negative,
When the position deviation determination unit determines that the deviation is greater than or equal to the second threshold value, the biting estimation unit determines whether the movable portion moves in the first movable direction or the second movable direction. It may be presumed that a biting state has occurred.

The movable portion is movable from a reference position in the first movable direction or the second movable direction,
When it is estimated that the drive control unit is in the biting state when the movable unit is driven from the reference position in the first movable direction and then returned to the reference position, the drive control unit then moves the movable unit to the first position. The driving force at the time of driving in one movable direction may be increased as compared with the case where it is not in the bitten state.

If it is estimated that the drive control unit is in the biting state when the movable unit is driven from the reference position in the second movable direction and then returned to the reference position, then the drive control unit sets the movable unit to the first position. The driving force at the time of driving in the two movable directions may be increased as compared with the case where it is not in the engaged state.

The position deviation determination unit may include a duration determination unit that determines whether or not the state in which the deviation is determined to be the second threshold value or more continues for a predetermined time limit or longer,
The biting estimation unit may estimate that the movable unit is in the biting state when the continuation time determination unit determines that the duration time continues for the time period or more.

A driving force determination unit that determines whether or not the driving force of the movable unit is equal to or greater than a first threshold,
When the driving force of the movable portion is determined to be equal to or higher than the first threshold value, a moving speed determination portion that determines whether or not the moving speed of the movable portion is equal to or lower than a third threshold value may be provided.
The biting estimation unit may estimate that the movable unit is in the biting state when the moving speed determination unit determines that the moving speed is equal to or lower than the third threshold value.

The flow rate control valve is an electromagnetic control valve having a coil that generates an electromagnetic force for driving the movable portion,
When it is estimated that the movable portion is in the biting state, the movable portion may have a voltage higher than the voltage applied to the coil in the non-biting state.

At a timing when a drive command for the movable portion is issued in a direction opposite to the direction in which the movable portion is driven, an actuator that drives the driven body by the working fluid discharged from the flow rate control valve drives the driven body. It may be the timing of lowering.

The movable part of the flow control valve is a first movable part,
It has a 2nd movable part which moves according to the working fluid discharged from the said flow control valve, and controls the supply amount of the working fluid with respect to the actuator which drives a driven body according to the position of the said 2nd movable part. An actuator control valve may be further provided,
After the drive control unit is estimated to be in the bitten state, a drive command for the first movable unit in a direction opposite to the drive direction of the first movable unit when in the bitten state is output. At the same timing, the first movable portion may be driven with a driving force larger than the driving force of the first movable portion in the non-engaged state.

In another aspect of the present invention, in a method of driving a flow control valve, which controls a discharge amount of a working fluid according to a position of a movable portion,
Biting occurs in at least one of a case where the movable part does not reach the movement target position and a case where the movable part does not reach the predetermined moving speed within a predetermined time from the timing when the drive command for the movable part is issued. Presumed to be in a crowded state,
When it is not in the jammed state at the timing when a drive command for the movable part in the opposite direction to the driving direction of the movable part when it is in the jammed state is output after it is estimated to be in the jammed state. The movable part is driven by a driving force larger than the driving force of the movable part.

The present invention can prevent the spool from sticking even if foreign matter is caught in the spool.

FIG. 3 is a block diagram showing a schematic configuration of a fluid pressure drive device according to the first embodiment. The wave form diagram which shows an example of operation|movement of a flow control valve and an actuator. The figure which shows typically the moving position of the spool in a flow control valve. The figure which shows typically the moving position of the spool in a flow control valve. 6 is a flowchart showing the processing operation of the bite estimation unit according to the first embodiment. 3 is a flowchart showing the processing operation of the drive control unit according to the first embodiment. The block diagram which shows schematic structure of the fluid pressure drive device by 2nd Embodiment. 9 is a flowchart showing the processing operation of the bite estimation unit according to the second embodiment. 9 is a flowchart showing the processing operation of the drive control unit according to the second embodiment.

Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In addition, in the drawings attached to the present specification, for convenience of illustration and understanding, the scale, the vertical and horizontal dimension ratios, etc. are appropriately changed and exaggerated from the actual ones. Further, as used in the present specification, the shape and geometric conditions and the degree thereof are specified. For example, terms such as “parallel”, “orthogonal”, and “identical” and length and angle values are strict. Without being bound by the meaning, it should be interpreted including the range in which similar functions can be expected. Hereinafter, embodiments of the present invention will be described in detail.

FIG. 1 is a block diagram showing a schematic configuration of a fluid pressure driving device 1 according to the first embodiment. The fluid pressure drive system 1 of FIG. 1 includes a flow rate control valve 2, an actuator 3, and a controller 4.

The flow rate control valve 2 includes a valve rod 2b having one or more spools (first movable portion) 2a. The flow rate control valve 2 moves the valve rod 2b to move the spool 2a to a desired position according to a command from the controller 4. The valve rod 2b is controlled to move in the longitudinal direction by, for example, a current flowing through an electromagnetic coil (not shown). Note that the valve rod 2b does not necessarily have to be moved by electrical control of an electromagnetic coil or the like, and may be moved by another control method (for example, hydraulic control). One of the moving positions of the spool 2a is the neutral position. When the spool 2a moves to the neutral position, both the hydraulic oil flowing into the flow control valve 2 and the hydraulic oil flowing out of the flow control valve 2 are shut off. Therefore, the controller 4 issues a command to move the spool 2a to the neutral position when it is desired to seal the flow of the hydraulic oil between the flow control valve 2 and the actuator 3.

The flow control valve 2 shown in FIG. 1 is provided with a plurality of ports through which hydraulic oil flows in and out, and the flow of hydraulic oil from each port is controlled according to the position of the spool 2a. For example, the flow rate control valve 2 has a port P1 to which hydraulic fluid is supplied from the actuator 3, a port P2 which supplies hydraulic fluid from the flow rate control valve 2 to the actuator 3, and a hydraulic fluid which is discharged from the flow rate control valve 2 to a tank. And port P3. The type and number of ports provided in the flow control valve 2 are arbitrary.

The actuator 3 has, for example, a movable portion (second movable portion) 3b that can move inside the hollow sleeve 3a. The actuator 3 changes the position of the movable portion 3b according to the amount of hydraulic oil discharged from the flow control valve 2. Although FIG. 1 shows an example in which the fuel injection valve 5 and the exhaust valve 6 are controlled by the movement of the movable portion 3b in the actuator 3, this is an example, and the object driven by the actuator 3 is arbitrary. ..

The fluid pressure drive device 1 of FIG. 1 includes a position detection unit 7 that detects the position of the spool 2a in the flow control valve 2 and a position detection unit 8 that detects the position of the movable unit 3b in the actuator 3. Good. The position detection unit 7 may include, for example, a gap sensor that is disposed on one end side of the flow control valve 2 and that measures the distance from the end surface of the valve rod in a non-contact manner. If the gap sensor measures the distance from the end face of the valve rod, the position of the spool 2a can also be detected.

The controller 4 performs feedback control so that the position of the spool 2a detected by the position detection unit 7 matches a predetermined movement target position. The movement target position is a command position of the controller 4. For example, when the fluid pressure driving device 1 is an electromagnetic control valve, the controller 4 applies the electromagnetic coil to the electromagnetic coil based on the deviation between the position of the spool 2a detected by the position detector 7 and a predetermined movement target position. Controls the magnitude and direction of voltage and current.

The controller 4 has a bite estimation unit 9 and a drive control unit 10. The bite estimation unit 9 estimates that the bite state is the bite state when the spool 2a does not reach the movement target position within a predetermined time from the timing when the drive command for moving the spool 2a of the flow control valve 2 to the movement target position is issued. To do. The foreign matter is often caught in the spool 2a when the spool 2a returns to the neutral position. Therefore, the biting estimation unit 9 estimates that the foreign matter has bitten into the spool 2a when the spool 2a returns to the neutral position. When a foreign matter is caught in the spool 2a, the spool 2a cannot return to the neutral position within a pre-determined time. Therefore, when the spool 2a cannot return to the movement target position (for example, the neutral position) within the predetermined time, the biting estimation unit 9 estimates that the foreign matter has bitten into the spool 2a. The predetermined time is set to a time longer than this time, based on the time required for the spool 2a to return to the neutral position from the timing when the drive command for the spool 2a is issued when no foreign matter is caught in the spool 2a. To be done.

The drive control unit 10 is not in the biting state at the timing when a drive command for the spool 2a is issued in the direction opposite to the driving direction of the spool 2a when the biting state is assumed after the drive control section 10 is estimated to be in the biting state. The spool 2a is driven by a driving force larger than the driving force of the spool 2a in the case. In this way, even if foreign matter is caught in the spool 2a and the spool 2a is fixed, by driving the spool 2a with a large driving force in the direction opposite to the moving direction of the spool 2a when the foreign matter is caught, The foreign matter caught in the spool 2a can be separated from the spool 2a to normalize the movement of the spool 2a. Here, at the timing when the drive command of the spool 2a in the opposite direction to the drive direction of the spool 2a when it is in the biting state is issued, the driven body is driven by the working fluid discharged from the flow control valve 2, for example. The timing at which the actuator 3 reduces the driving force of the driven body. That is, if foreign matter is caught in the spool 2a when the spool 2a is moved to increase the driving force of the driven body and then returned to the neutral position, then the spool 2a is reduced in direction of decreasing the driving force of the driven body. Increase the driving force when moving.

The controller 4 may include a driving force determination unit 11 and a position deviation determination unit 12. The driving force determination unit 11 determines whether the driving force of the spool 2a of the flow rate control valve 2 is equal to or more than the first threshold value. When the driving force of the spool 2a of the flow rate control valve 2 is determined to be equal to or higher than the first threshold value, the position deviation determination unit 12 determines the movement target position of the spool 2a of the flow rate control valve 2 and the spool 2a of the flow rate control valve 2. It is determined whether the deviation from the actual position is the second threshold value or more. The biting estimation unit 9 estimates that the spool 2a of the flow control valve 2 is in a biting state when the position deviation determination unit 12 determines that the deviation is equal to or more than the second threshold value.

The driving force determination unit 11 may determine whether the driving force of the movable portion 3b of the actuator 3 is equal to or higher than the first threshold value. In this case, when the driving force of the movable portion 3b of the actuator 3 is determined to be the first threshold value or more, the position deviation determination unit 12 determines that the deviation between the movement target position and the actual position of the movable portion 3b of the flow rate control valve 2 is equal to or greater than the first threshold value. It may be determined whether or not it is equal to or more than the second threshold value.

The position deviation determination unit 12 may determine whether the deviation when the spool 2a moves in the first movable direction or the second movable direction is equal to or larger than the second threshold value, based on whether the deviation is positive or negative. In this case, the biting estimation unit 9 determines the biting state when the spool 2a moves in the first movable direction or the second movable direction when the position deviation determination unit 12 determines that the deviation is greater than or equal to the second threshold value. Presumed to have become.

The spool 2a of the flow rate control valve 2 is movable in the first movable direction or the second movable direction from the reference position. When it is estimated that the drive control unit 10 is in the biting state when the spool 2a of the flow control valve 2 is driven from the reference position to the first movable direction and then returned to the reference position, the spool 2a is then moved to the first movable direction. The driving force at the time of driving in the direction is increased more than that in the non-engaged state. Further, when it is estimated that the drive control unit 10 is in the biting state when the spool 2a is driven from the reference position to the second movable direction and then returned to the reference position, the drive control unit 10 then drives the spool 2a in the second movable direction. The driving force at the time of increasing is increased as compared with the case where it is not in the engaged state.

The controller 4 may include the duration determination unit 13. The duration determination unit 13 determines whether or not the position deviation determination unit 12 determines that the deviation is greater than or equal to the second threshold value for a predetermined time limit or longer. When the biting continuation time determination unit 13 determines that the biting duration determination unit 13 continues for the time limit or longer, the biting estimation unit 9 estimates that the movable portion 3b is in the biting state.

FIG. 2 is a waveform diagram showing an example of the operation of the flow rate control valve 2 and the actuator 3, and FIGS. 3A and 3B are diagrams schematically showing the movement position of the spool 2 a in the flow rate control valve 2. The spool 2a of the flow control valve 2 is assumed to remain in the neutral position in the initial state.

At time t1 in FIG. 2, the controller 4 commands the flow control valve 2 to supply hydraulic oil to the actuator 3. In response to this command, the spool 2a moves from the neutral position to the left side in the figure, as shown in FIG. 3A. The movement of the spool 2a to the left is performed from time t1 to time t2. During this time, the spool 2a moves at a constant speed. As a result, the hydraulic oil flows from the port P1 toward the port P2, and the hydraulic oil is supplied from the flow rate control valve 2 to the actuator 3. The movable portion 3b of the actuator 3 moves upward, for example, when hydraulic oil is supplied from the flow control valve 2.

At time t2, the controller 4 issues a drive command for returning the spool 2a of the flow control valve 2 to the neutral position. In response to this command, the spool 2a of the flow control valve 2 returns to the neutral position, and the supply of hydraulic oil from the flow control valve 2 to the actuator 3 is stopped. From time t2 to time t3, the spool 2a of the flow control valve 2 remains in the neutral position.

At time t3, the controller 4 commands the flow rate control valve 2 to discharge the hydraulic oil from the actuator 3 to the tank. In response to this command, the spool 2a moves from the neutral position to the right side in the figure, as shown in FIG. 3B. The movement of the spool 2a to the right is performed from time t3 to time t4. During this time, the spool 2a moves at a constant speed. As a result, the hydraulic oil flowing from the actuator 3 into the port P2 is discharged from the port P3 to the tank.

At time t4, the controller 4 commands the flow rate control valve 2 to supply the hydraulic oil to the actuator 3 to the flow rate control valve 2. In response to this command, the spool 2a passes through the neutral position and moves to the left as shown in FIG. 3A. The movement of the spool 2a to the left is performed from time t4 to time t5.

At time t5, the controller 4 issues a drive command for returning the spool 2a of the flow control valve 2 to the neutral position. In response to this command, the spool 2a of the flow control valve 2 returns to the neutral position, and the supply of hydraulic oil from the flow control valve 2 to the actuator 3 is stopped. From time t5 to t6, the spool 2a of the flow control valve 2 remains in the neutral position.

From time t6 to t7, the spool 2a moves from the neutral position to the right, and the hydraulic oil from the actuator is discharged to the tank, as in time t3 to t4. At time t7, the controller 4 issues a drive command to return the spool 2a of the flow control valve 2 to the neutral position. Upon receipt of this command, the spool 2a of the flow control valve 2 returns to the neutral position, but at this time, it is assumed that the foreign matter in the hydraulic oil has been caught in the spool 2a. In this case, since the spool 2a is fixed immediately before the neutral position, the spool 2a does not move under normal driving force. In many cases, the foreign matter is caught in the spool 2a immediately before the spool 2a returns to the neutral position. When a foreign matter is caught in the spool 2a, the spool 2a cannot be completely returned to the neutral position. Therefore, by detecting the position of the spool 2a by the position detection unit 7, it can be estimated that the foreign matter is caught in the spool 2a. In the present embodiment, the biting estimation unit 9 estimates that a foreign substance has bitten into the spool 2a.

When it is estimated by the biting estimation unit 9 that the foreign matter has bitten into the spool 2a, the controller 4 then moves in a direction opposite to the moving direction of the spool 2a when the foreign material bites into the spool 2a. The driving force for moving the spool 2a is made larger than the driving force for the spool 2a when no foreign matter is caught. In the example of FIG. 2, at time t8, the controller 4 commands the flow rate control valve 2 to discharge the hydraulic oil from the actuator 3 to the tank, and makes the driving force of the spool 2a larger than usual. To do. As a result, the spool 2a that has caught the foreign matter is pulled in a direction opposite to the biting direction with a driving force that is larger than the driving force when the foreign matter is caught, and the foreign matter is removed from the spool 2a. ..

After that, at times t10 to t11, the controller 4 moves the spool 2a of the flow control valve 2 to the left of the neutral position in order to supply hydraulic oil from the flow control valve 2 to the actuator 3 at times t10 to t11. .. At time t11, the controller 4 issues a drive command for returning the spool 2a of the flow rate control valve 2 to the neutral position, but it is assumed that the foreign matter is caught in the spool 2a immediately before returning to the neutral position. The foreign matter biting into the spool 2a is estimated by the biting estimating unit 9 as described above.

After that, at time t12, the controller 4 issues a drive command to move the spool 2a in the direction opposite to the foreign matter biting direction. At this time, the spool 2a is moved with a driving force larger than the normal driving force. As a result, the foreign matter caught in the spool 2a is removed from the spool 2a.

FIG. 4 is a flowchart showing the processing operation of the bite estimation unit 9 according to the first embodiment. The process of the flowchart of FIG. 4 is repeatedly executed during the period when the fluid pressure drive device 1 is operating. First, it is determined whether the driving force of the spool 2a of the flow rate control valve 2 is equal to or more than the first threshold value (step S1). The reason for providing step S1 is that when foreign matter is caught in the spool 2a, a driving force higher than usual is applied to the spool 2a in order to return the spool 2a to the neutral position. The determination processing in step S1 is performed by the driving force determination unit 11.

When it is determined in step S1 that the driving force of the spool 2a is equal to or larger than the first threshold value, it is determined whether the positional deviation of the spool 2a is equal to or larger than the second threshold value in the positive direction (step S2). The positive direction means that the positional deviation of the spool 2a in the right direction is equal to or more than the second threshold value. The reason why step S2 is provided is that when a foreign substance is caught in the spool 2a, the spool 2a is fixed and cannot reach the movement target position. The positional deviation of the spool 2a is determined by the positional deviation determining unit 12. The position deviation determination unit 12 detects the actual position of the spool 2a by the position detection unit 7, and determines whether the deviation between the detected actual position and the predetermined movement target position is the second threshold value or more.

When the position deviation is determined to be equal to or more than the second threshold value in the positive direction in step S2, it is determined whether or not a predetermined time has elapsed since the position deviation was equal to or more than the second threshold value (step S3). The reason why step S3 is provided may be that the movement of the spool 2a is temporarily slowed for reasons other than the foreign matter being caught in the spool 2a. This is because they are fixed and do not move even if a predetermined time has passed. In step S3, the elapsed time after the position deviation becomes equal to or greater than the second threshold value is substituted into the variable t, and the determination is made depending on whether or not the variable t is equal to or greater than a predetermined time. The determination process of step S3 is performed by the duration determination unit 13.

If it is determined in step S3 that the predetermined time has elapsed, the variable t is initialized to 0, and a flag indicating that a foreign object is caught when the spool 2a is moved rightward (hereinafter, (+) bite). The inclusion flag) is set (step S4), and the processing of FIG. 4 ends. If it is determined in step S3 that the predetermined time has not elapsed, the variable t is updated (step S5), and the process of FIG. 4 ends.

When it is determined in step S2 that the positional deviation of the spool 2a is less than the second threshold value, it is determined whether the positional deviation of the spool 2a is greater than or equal to the second threshold value in the negative direction (step S6). The negative direction means that the position deviation of the spool 2a in the leftward direction is equal to or more than the second threshold value, for example. When it is determined in step S6 that the value is equal to or more than the second threshold in the negative direction, it is determined whether or not a predetermined time has elapsed since the position deviation was equal to or more than the second threshold (step S7). When it is determined that the predetermined time has elapsed, the variable t is initialized to 0, and a flag indicating that a foreign object is caught when the spool 2a is moved leftward (hereinafter, a (-) catching flag). Is set (step S8), and the process of FIG. 4 ends. If it is determined in step S7 that the predetermined time has not yet elapsed, the process of step S5 is performed and the process of FIG. 4 ends.

If it is determined in step S1 that the driving force of the spool 2a is less than the first threshold value, or if the positional deviation of the spool 2a is less than the second threshold value in the negative direction in step S6, the variable t is initialized to 0. (Step S9), and the process of FIG. 4 ends.

FIG. 5 is a flowchart showing the processing operation of the drive control unit 10 according to the first embodiment. The process of the flowchart of FIG. 5 is repeatedly executed during the period when the fluid pressure drive device 1 is operating. First, it is determined whether or not the (+) bite flag is set (step S11). When the (+) bite flag is set, it is determined whether the positional deviation of the spool 2a of the flow control valve 2 is greater than or equal to the second threshold value in the negative direction (step S12). When the spool 2a is moved in the positive direction, foreign matter is caught and fixed, and then the spool 2a does not move even if the spool 2a is moved in the negative direction. Therefore, the positional deviation in the negative direction becomes equal to or larger than the second threshold value. If the position deviation is greater than or equal to the second threshold value in the negative direction in step S12, it indicates that the foreign matter is caught in the spool 2a when moving in the positive direction.

When the position deviation is determined to be the second threshold value or more in the negative direction in step S12, the driving force of the spool 2a is increased (step S13). When the flow rate control valve 2 is an electromagnetic control valve, the spool 2a moves according to the voltage supplied to the electromagnetic coil, so that the voltage supplied to the electromagnetic coil is made higher than usual in step S13.

By step S13, a driving force is generated on the spool 2a on the left side in the direction opposite to the direction in which the foreign matter is caught, and the foreign matter is removed from the spool 2a. Therefore, the (+) bite flag is reset (step S14). In addition, in step S13, the driving force applied to the spool 2a may be gradually increased. That is, if the foreign matter caught in the spool 2a is not removed by the first-stage driving force, a larger second-stage driving force may be applied to the spool 2a.

When it is determined in step S12 that the positional deviation of the spool 2a is less than the second threshold value in the negative direction, it is determined that the foreign matter caught in the spool 2a has been removed, and the process of FIG. 5 ends.

When it is determined in step S11 that the (+) bite flag is not set, it is determined whether the (-) bite flag is set (step S15). When the (-) bite flag is set, it is determined whether the positional deviation of the spool 2a of the flow control valve 2 is equal to or more than the second threshold value in the positive direction (step S16). When the spool 2a is moved in the negative direction, foreign matter is bitten and fixed, and then the spool 2a does not move even if the spool 2a is moved in the positive direction. Therefore, the position deviation in the positive direction becomes equal to or larger than the second threshold value. If the position deviation is equal to or larger than the second threshold value in the positive direction in step S12, it indicates that the foreign matter is caught in the spool 2a when moving in the negative direction.

When it is determined in step S16 that the positional deviation is equal to or larger than the second threshold value, the driving force of the spool 2a is increased (step S17). Then, when the foreign matter caught in the spool 2a is removed, the (-) caught flag is reset (step S18).

As described above, in the present embodiment, when foreign matter is caught in the spool 2a of the flow rate control valve 2, the spool 2a is driven in a direction opposite to the biting direction with a driving force larger than the normal driving force. It is possible to eliminate the foreign matter from being caught in the spool 2a. According to the present embodiment, it can be estimated that the foreign matter is caught in the spool 2a without disassembling the flow control valve 2, and if it is estimated that the foreign matter is caught in the spool 2a, By controlling the driving force of the spool 2a, it is possible to prevent the foreign matter from being caught in the spool 2a, so that the frequency of defective fixing of the spool 2a can be significantly reduced. As a result, the frequency of disassembling and repairing the flow control valve 2 can be reduced, and the labor of dispatching a maintenance worker can be saved, so that the maintenance cost can be significantly reduced.

(Second embodiment)
The second embodiment is different from the first embodiment in the processing operation of the bite estimation unit 9 and the drive control unit 10.

FIG. 6 is a block diagram showing a schematic configuration of the fluid pressure drive system 1 according to the second embodiment. The fluid pressure drive system 1 of FIG. 6 includes a moving speed determination unit 14 instead of the position deviation determination unit 12 and the duration determination unit 13 of FIG. When it is determined that the driving force of the spool 2a of the flow rate control valve 2 is equal to or higher than the first threshold value, the movement speed determination unit 14 determines whether the movement speed of the spool 2a is equal to or lower than the third threshold value.

Further, the fluid pressure drive device 1 of FIG. 6 includes a displacement detection unit 15. The displacement detector 15 detects the displacement of the spool 2a, that is, the moving speed. The displacement detector 15 can detect the displacement of the spool 2a by differentiating the position information of the spool 2a detected by the position detector 7. Alternatively, the displacement detector 15 may include a speed sensor that directly detects the moving speed of the spool 2a.

FIG. 7 is a flowchart showing the processing operation of the bite estimation unit 9 according to the second embodiment. First, it is determined whether the driving force of the spool 2a is the first threshold value or more (step S21). If it is determined that it is equal to or higher than the first threshold, it is determined whether the moving speed of the spool 2a detected by the displacement detection unit 15 is equal to or lower than the third threshold in the first direction (for example, rightward direction) (step S22). If it is determined that the moving speed of the spool 2a is equal to or lower than the third threshold, it is determined whether or not a predetermined time has elapsed (step S23). The processes of steps S24 and S25 based on the determination result of step S23 are the same as steps S4 and S5 of FIG.

If it is determined in step S22 that the moving speed of the spool 2a is not less than or equal to the third threshold value in the first direction, it is determined whether the moving speed of the spool 2a is less than or equal to the third threshold value in the second direction (for example, the left direction) ( Step S26). If it is determined that the moving speed of the spool 2a is equal to or lower than the third threshold, it is determined whether a predetermined time has elapsed (step S27). The processes of steps S28 and S29 based on the determination result of step S27 are the same as steps S8 and S9 of FIG.

FIG. 8 is a flowchart showing the processing operation of the drive control unit 10 according to the second embodiment. First, it is determined whether or not the (+) bite flag is set (step S31). When the (+) bite flag is set, it is determined whether the moving speed of the spool 2a in the second direction (for example, the left direction) detected by the displacement detecting unit 15 is equal to or less than the fourth threshold value. (Step S32). The processing of steps S33 and S34 performed when the determination processing of step S32 is YES is the same as the processing of steps S13 and S14 of FIG.

When it is determined in step S31 that the (+) bite flag is not set, it is determined whether the (-) bite flag is set (step S35). If it is determined that the spool 2a is set in step S35, it is determined whether the moving speed of the spool 2a in the first direction (for example, the right direction) detected by the displacement detector 15 is equal to or less than the fourth threshold value (step S35). S36). The processes of steps S37 and S38 performed when the determination process of step S36 is YES are the same as the processes of steps S17 and S18 of FIG.

As described above, in the second embodiment, it is determined based on the moving speed of the spool 2a of the flow rate control valve 2 in which direction the spool 2a is moved, and whether or not the foreign matter is caught, and the spool 2a is fixed. If it is determined that the spool 2a is driven with a driving force larger than the normal driving force in the direction opposite to the biting direction, as in the first embodiment, foreign matter on the spool 2a is not detected. The bite can be quickly eliminated.

In each of the above-described embodiments, the fluid pressure drive device 1 including the flow rate control valve 2 and the actuator 3 has been described, but since the configuration and the operation of the actuator 3 are arbitrary, the hydraulic oil discharged from the flow rate control valve 2 is used. The present invention can be widely applied to the fluid pressure drive device 1 that performs various operations by utilizing. It suffices that the flow rate control valve 2 has a spool 2a and controls the discharge amount of the hydraulic oil according to the position of the spool 2a. Specific examples of the flow rate control valve 2 are applicable to a poppet valve, a ball valve, a needle valve, etc., in addition to the spool 2a valve described above. The actuator 3 has a movable portion 3b whose position can be changed according to the discharge amount of the hydraulic oil from the flow control valve 2, and directly drives the actuator shaft according to the position of the movable portion 3b. May be a valve that controls the amount of hydraulic oil supplied to a separate actuator depending on the position. A specific example of the drive unit may be a spool valve, a poppet valve, or a fluid pressure drive motor such as a hydraulic motor, in addition to the movable unit 3b type actuator 3 described above.

Aspects of the present invention are not limited to the individual embodiments described above, but include various modifications that can be conceived by those skilled in the art, and the effects of the present invention are not limited to the contents described above. That is, various additions, changes and partial deletions are possible without departing from the conceptual idea and spirit of the present invention derived from the contents defined in the claims and the equivalents thereof.

1 fluid pressure drive device, 2 flow control valve, 2a spool, 3 actuator, 3a sleeve, 3b movable part, 4 controller, 5 fuel injection valve, 6 exhaust valve, 7 position detecting part, 8 position detecting part, 9 bite estimation Section, 10 drive control section, 11 drive force determination section, 12 position deviation determination section, 13 continuous time determination section, 14 moving speed determination section, 15 displacement detection section

Claims (11)

A flow rate control valve having a movable part and controlling the discharge amount of the working fluid according to the position of the movable part;
When the movable portion does not reach the movement target position within a predetermined time from the timing of the drive command for moving the movable portion to the movement target position, and when the movable portion moves to the movement target position, A biting estimation unit that estimates that the vehicle is in a biting state when at least one of the moving speed is not reached, and
When it is not in the jammed state at the timing when a drive command for the movable part in the opposite direction to the driving direction of the movable part when it is in the jammed state is output after it is estimated to be in the jammed state. And a drive control section that drives the movable section with a driving force larger than the driving force of the movable section. A driving force determination unit that determines whether or not the driving force of the movable unit is equal to or greater than a first threshold,
Position deviation for determining whether or not the deviation between the movement target position of the movable portion and the actual position of the movable portion is equal to or greater than a second threshold when the driving force of the movable portion is determined to be equal to or greater than the first threshold value. And a determination unit,
The fluid according to claim 1, wherein the bite estimation unit estimates that the movable portion is in the bite state when the position deviation determination unit determines that the deviation is equal to or more than the second threshold value. Pressure drive device. The position deviation determination unit determines whether or not the deviation when the movable unit moves in the first movable direction or the second movable direction is equal to or more than the second threshold value based on whether the deviation is positive or negative,
When the position deviation determination unit determines that the deviation is greater than or equal to the second threshold value, the biting estimation unit determines whether the movable portion moves in the first movable direction or the second movable direction. The fluid pressure drive device according to claim 2, which is presumed to be in a biting state. The movable portion is movable from a reference position in the first movable direction or the second movable direction,
When it is estimated that the drive control unit is in the biting state when the movable unit is driven from the reference position in the first movable direction and then returned to the reference position, the drive control unit then moves the movable unit to the first position. The fluid pressure drive device according to claim 3, wherein the driving force for driving in one movable direction is increased as compared with the case where the engagement state is not set. If it is estimated that the drive control unit is in the biting state when the movable unit is driven from the reference position in the second movable direction and then returned to the reference position, then the drive control unit sets the movable unit to the first position. The fluid pressure drive device according to claim 4, wherein a driving force when driving in two movable directions is increased as compared with a case where the driving force is not in the engaged state. The position deviation determination unit includes a duration determination unit that determines whether the state in which the deviation is determined to be the second threshold value or more continues for a predetermined time limit or longer,
The entrapment estimation unit estimates that the movable part is in the entrapped state when the continuation time determination unit determines to continue for the time limit or longer. The fluid pressure drive device described. A driving force determination unit that determines whether or not the driving force of the movable unit is equal to or greater than a first threshold,
A moving speed determination unit that determines whether or not the moving speed of the movable unit is equal to or lower than a third threshold value when the driving force of the movable unit is determined to be equal to or higher than the first threshold value,
The said biting estimation part estimates that the said movable part is in the said biting state, when the said moving speed is judged to be below the said 3rd threshold value by the said moving speed determination part, The said biting estimation part. Fluid pressure drive. The flow rate control valve is an electromagnetic control valve having a coil that generates an electromagnetic force for driving the movable portion,
8. The movable part, when it is estimated that the movable part is in the biting state, makes the voltage higher than the applied voltage of the coil when not in the biting state. Fluid pressure drive device. At a timing when a drive command for the movable portion is issued in a direction opposite to the direction in which the movable portion is driven, an actuator that drives the driven body by the working fluid discharged from the flow rate control valve drives the driven body. The fluid pressure drive device according to any one of claims 1 to 8, which is a timing of lowering. The movable part of the flow control valve is a first movable part,
It has a 2nd movable part which moves according to the working fluid discharged from the said flow control valve, and controls the supply amount of the working fluid with respect to the actuator which drives a driven body according to the position of the said 2nd movable part. Further equipped with an actuator control valve,
After the drive control unit is estimated to be in the bitten state, a drive command for the first movable unit in a direction opposite to the drive direction of the first movable unit when in the bitten state is output. 10. The fluid pressure drive according to any one of claims 1 to 9, wherein the first movable portion is driven with a driving force larger than the driving force of the first movable portion when not in the biting state at different timings. apparatus. In the method of driving the flow control valve, which controls the discharge amount of the working fluid according to the position of the movable part,
Biting occurs in at least one of a case where the movable part does not reach the movement target position and a case where the movable part does not reach the predetermined moving speed within a predetermined time from the timing when the drive command for the movable part is issued. Presumed to be in a crowded state,
When it is not in the jammed state at the timing when a drive command for the movable part in the opposite direction to the driving direction of the movable part when it is in the jammed state is output after it is estimated to be in the jammed state. The driving method of the flow control valve, wherein the movable portion is driven with a driving force larger than the driving force of the movable portion.

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