KR102470124B1 - State monitoring apparatus and fluid pressure driving apparatus - Google Patents

Abstract

Investigate the degree of wear of moving parts such as spools simply and accurately.
The fluid pressure drive device includes: a first information acquisition unit that acquires the position of the first movable unit in a flow control valve that controls the discharge amount of working fluid according to the position of the first movable unit; and an operation discharged from the flow control valve. A second information acquisition unit for acquiring the position of the second movable unit in an actuator having a second movable unit that moves the position in accordance with the fluid, and the position of the first movable unit acquired by the first information acquisition unit is a state determination unit for determining whether or not a neutral position is reached at which the supply of working fluid is stopped; and when the state determination unit determines that the neutral position is the neutral position, the first movable unit is configured based on the displacement per unit time of the second movable unit. A state estimation unit for estimating a state is provided.

Description

State monitoring device and fluid pressure driving device {STATE MONITORING APPARATUS AND FLUID PRESSURE DRIVING APPARATUS}

This application is based on a Japanese patent application (Japanese Patent Application No. 2018-246007, filing date: 12/27/2018), and enjoys priority from this application. By referring to this application, all of the contents of the same application are included.

The present invention relates to a condition monitoring device and a fluid pressure drive device.

One of the failures of the flow control valve that controls the discharge amount of hydraulic oil is leakage of hydraulic oil due to wear of the spool (also called a valve body) of the flow control valve. Originally, when the spool is in a neutral position, the hydraulic oil must be reliably sealed, and the hydraulic oil must be discharged when the spool moves from the neutral position.

However, if a foreign substance is mixed in the hydraulic fluid in the flow control valve, the surface of the spool is scraped off by the foreign substance, and even if the spool moves to the neutral position, there is a possibility that the hydraulic oil leaks from a gap caused by wear of the spool.

Even if the spool moves to the neutral position, when hydraulic oil leaks, it becomes a factor that causes malfunction of the drive unit driven by the flow control valve or the actuator controlled by the drive unit. Moreover, if the leakage amount of hydraulic oil becomes excessive, the supply of hydraulic oil will run short, and sufficient working hydraulic pressure will not be obtained, and the efficiency of a drive part and an actuator will fall.

If the degree of abrasion of the spool can be investigated without disassembling the flow control valve, maintenance costs can be reduced, which is preferable.

Japanese Unexamined Patent Publication No. 2016-50785

The problem to be solved by the present invention is to provide a state monitoring device and a fluid pressure drive device capable of simply and accurately examining the degree of wear of a movable part such as a spool.

In order to solve the above problems, in one aspect of the present invention, a first information acquisition unit for acquiring the position of the first movable unit in a flow control valve that controls the discharge amount of the working fluid according to the position of the first movable unit; and ,

a second information acquisition unit that acquires a position of the second movable unit in an actuator having a second movable unit that moves a position in accordance with the working fluid discharged from the flow control valve;

a state determination unit for determining whether or not the position of the first movable unit acquired by the first information acquisition unit is a neutral position at which supply of working fluid to the actuator is stopped;

A state estimating unit for estimating the state of the first movable unit based on the displacement per unit time of the second movable unit when the neutral position is determined by the state judging unit.

A state monitoring device provided is provided.

A detection unit for detecting that the first movable unit is located at the neutral position where supply of the working fluid to the actuator is stopped;

The state judging unit may determine that the position of the first movable unit is the neutral position when it is detected by the detecting unit that it is located at the neutral position.

A detection unit for detecting a command for moving the first movable unit to the neutral position,

The state determination unit may determine that the position of the first movable unit is the neutral position when the command is detected by the detection unit.

In another aspect of the present invention, a flow control valve for controlling the discharge amount of the working fluid according to the position of the first movable unit;

an actuator having a second movable part that moves a position according to the working fluid discharged from the flow control valve;

a position detector for detecting a position of the second movable part;

Based on the displacement per unit time of the second movable part calculated from the position of the second movable part detected by the position detecting part in a state in which the supply of the working fluid from the flow control valve to the actuator is stopped, the first State estimator for estimating the state of the moving part

A fluid pressure drive device provided is provided.

The displacement may be at least one of a displacement speed of the second movable unit and a time from when the second movable unit receives a command to stop the second movable unit at a predetermined position until it starts to move.

A warning unit for issuing a predetermined warning when the displacement exceeds a predetermined threshold may be provided.

A life predicting unit for predicting the life of the first movable unit based on the state of the first movable unit estimated over a predetermined period by the state estimating unit may be provided.

The actuator is arranged in a vertical direction,

The second movable part may descend by its own weight in a state in which a command to stop the second movable part at a predetermined position is received and the supply of working fluid from the flow control valve to the actuator is stopped.

When performing state estimation of the first movable part, the state estimating part detects the displacement of the second movable part after moving the first movable part from the flow control valve to a position where supply of the working fluid to the actuator is stopped. You can do it.

The said actuator may be a valve which controls the supply amount of the working fluid to another actuator driven by the working fluid supplied from the said actuator according to the position of the said 2nd movable part.

A mode selection unit capable of selecting a test mode for estimating the state of the first movable unit,

When the test mode is selected in the mode selection unit, the state estimation unit moves the second movable unit to a neutral position, moves the first movable unit to a neutral position, and obtains positional information of the second movable unit. The state of the first movable part may be estimated in a state where control for returning to the flow control valve is stopped.

According to the present invention, it is possible to simply and accurately examine the degree of wear of a movable part such as a spool.

1 is a block diagram showing a schematic configuration of a fluid pressure drive device with a state monitoring device according to a first embodiment.
Fig. 2 is a block diagram showing a schematic configuration of a fluid pressure drive device according to a second embodiment.
(a) and (b) of FIG. 3 are diagrams showing examples of different paths through which hydraulic fluid leaks.
4 is a diagram showing a schematic configuration of a fluid pressure drive device according to a third embodiment.
Fig. 5 is a diagram showing a schematic configuration of a fluid pressure drive device according to a fourth embodiment.

Hereinafter, one embodiment of the present disclosure will be described with reference to the drawings. In addition, in the drawings accompanying this specification, for convenience of illustration and understanding, the scale and size ratio of length and width are changed from those of the real thing and exaggerated as appropriate. In addition, the exact meaning of terms used in this specification, such as "parallel", "orthogonal", and "equal", values of lengths and angles, etc., which specify shapes and geometrical conditions and their degree, for example It is assumed that the analysis includes the range of the extent to which similar functions can be expected without being constrained by . EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail.

(First Embodiment)

1 is a block diagram showing a schematic configuration of a fluid pressure drive device 1 provided with a state monitoring device 15 according to a first embodiment. The fluid pressure drive device 1 of FIG. 1 includes a flow control valve 2 , an actuator 3 , and a state monitoring device 15 .

The flow control valve 2 has a valve stem 2b having one or more spools 2a (first movable parts). The flow control valve 2 moves the valve rod 2b and moves the spool 2a to a desired position according to a command of the controller 6 . The valve stem 2b is controlled to move left and right in the illustration by, for example, a current flowing through an electromagnetic coil (not shown). In addition, the valve rod 2b does not necessarily need to be moved by electric control such as an electromagnetic coil, and may be moved by another control method (eg, hydraulic control). One of the moving positions of the spool 2a is the neutral position. When the spool 2a is moved to the neutral position, both hydraulic oil flowing into the flow control valve 2 and hydraulic oil flowing out of the flow control valve 2 are blocked. Therefore, the controller 6 issues a command to move the spool 2a to the neutral position when trying to seal the flow of hydraulic oil between the flow control valve 2 and the actuator 3.

The controller 6 detects the position of the spool 2a based on the detection signal of the position detector 7 that detects the position of the valve stem 2b of the flow control valve 2, and the detected spool 2a Feedback control may be performed so that the position of is coincident with a predetermined target position. A target position is a command position of the controller 6.

The flow control valve 2 of FIG. 1 is provided with a plurality of ports through which hydraulic oil flows in and out, and the inflow and outflow of hydraulic oil from each port is controlled according to the position of the spool 2a. For example, the flow control valve 2 includes a port P1 through which hydraulic oil from the actuator 3 flows in, a port P2 through which hydraulic oil is supplied from the flow control valve 2 to the actuator 3, and a flow control valve ( 2) has a port P3 to drain the hydraulic fluid from the tank to the tank. In addition, the type and number of ports provided in the flow control valve 2 are arbitrary.

The actuator 3 has, for example, a movable part (second movable part) 3b that is movable within the hollow sleeve 3a. The actuator 3 changes the position of the movable part 3b according to the discharge amount of hydraulic oil from the flow control valve 2 . 1 shows an example in which the fuel injection valve 8 and the exhaust valve 9 are controlled by the movement of the movable part 3b in the actuator 3, but this is an example and the object driven by the actuator 3 is arbitrary.

The actuator 3 may include a position detection unit 10 that detects the position of the movable unit 3b. The position detection part 10 is arrange|positioned on the one end side of the movable part 3b, for example, and detects the distance with the movable part 3b non-contact.

The state monitoring device 15 includes a first information acquisition unit 16, a second information acquisition unit 17, a state judgment unit 18, and a state estimation unit 5. In addition, the state monitoring device 15 may include a command detection unit 19 . The first information acquisition unit 16 , the second information acquisition unit 17 , the state determination unit 18 , and the state estimation unit 5 may be incorporated in the controller 6 .

The 1st information acquisition part 16 acquires the position of the spool 2a in the flow control valve 2 which controls the discharge amount of a working fluid according to the position of the spool (1st movable part) 2a.

The 2nd information acquisition part 17 is the movable part 3b in the actuator 3 which has the movable part (second movable part) 3b which moves a position according to the working fluid discharged from the flow control valve 2 get a location

The state determination unit 18 determines whether or not the position of the spool 2a acquired by the first information acquisition unit 16 is a neutral position at which the supply of the working fluid to the actuator 3 is stopped.

The state estimating section 5 estimates the state of the spool 2a based on the displacement per unit time of the movable section 3b when the neutral position is determined by the state judging section 18.

The position detection unit 7 can detect that the spool 2a is positioned at a neutral position where supply of the working fluid to the actuator 3 is stopped. Therefore, the state judgment part 18 may judge that the position of the spool 2a is a neutral position, when it is detected by the position detection part 7 that it is located in the neutral position.

The command detection unit 19 can detect a command to move the spool 2a to the neutral position. Accordingly, the state judgment unit 18 may determine that the position of the spool 2a is the neutral position when the command detection unit 19 detects the command.

In this way, the state monitoring device 15 of FIG. 1 monitors the state of the spool 2a based on the displacement of the movable part 3b of the actuator 3 when it is determined that the spool 2a is located in the neutral position. Because of the estimation, the degree of wear of the spool 2a can be judged with high accuracy without disassembling the flow control valve 2 and taking out the spool 2a.

(Second Embodiment)

2 is a block diagram showing a schematic configuration of a fluid pressure drive device 1 according to a second embodiment. The fluid pressure drive device 1 of FIG. 2 includes a flow control valve 2 , an actuator 3 , a displacement detection unit 4 , and a state estimation unit 5 . The state estimation unit 5 constitutes a part of the controller 6, for example.

The flow control valve 2 and the actuator 3 of FIG. 2 are the same as the flow control valve 2 and the actuator 3 of FIG. 1, and detailed descriptions are omitted.

The displacement detection unit 4 detects the displacement of the movable unit 3b in the actuator 3 . Here, the displacement is at least one of the displacement speed of the movable part 3b and the time from when the movable part 3b receives a movement command to when it starts to move. For example, when the position detection unit 10 for detecting the position of the movable part 3b is provided, the displacement detection unit 4 differentially processes the position of the movable part 3b detected by the position detection unit 10, The displacement speed of the movable part 3b can be detected. Alternatively, the displacement detection unit 4 may include a speed sensor that directly detects the displacement speed of the movable unit 3b.

The state estimation unit 5 determines the position of the movable part (second movable part) 3b detected by the position detection unit 10 in a state where the supply of the working fluid from the flow control valve 2 to the actuator 3 is stopped. The state of the spool (first movable part) 2a is estimated based on the displacement per unit time of the movable part 3b calculated therefrom. The displacement is at least one of the displacement speed of the movable part 3b and the time from receiving a command to stop the movable part 3b at a predetermined position until it starts to move. More specifically, the state estimation unit 5 estimates the state of the spool 2a of the flow control valve 2 based on the displacement detected by the displacement detection unit 4 . When the spool 2a is in the neutral position, since the flow control valve 2 seals the hydraulic oil, essentially no inflow and outflow of hydraulic oil will occur between the flow control valve 2 and the actuator 3. However, when the spool 2a is worn, as indicated by the arrow in FIG. 3(a) or FIG. 3(b), even if the spool 2a is in the neutral position, hydraulic fluid leaks from the gap between the spool 2a and throw away As shown in Fig. 3(a) and Fig. 3(b), it is conceivable that the direction in which the hydraulic fluid leaks also changes depending on where the spool 2a is worn. Depending on the direction in which the hydraulic oil leaks, a force to raise the movable part 3b of the actuator 3 upward or a force to lower it downward acts. The state estimation unit 5 may detect the displacement of the movable unit 3b after moving the spool 2a from the flow control valve 2 to the position where the supply of the working fluid to the actuator 3 is stopped.

When the actuator 3 is arranged in the direction of moving the movable part 3b in the vertical direction, for example, as shown in FIG. 2, the spool 2a of the flow control valve 2 is in a neutral position. In this case, the movable part 3b inherently falls downward at a constant speed due to its own weight. On the other hand, when the spool 2a is worn, even when the spool 2a is in the neutral position, hydraulic oil leaks from the gap between the spool 2a to the actuator 3 side, so the falling speed of the movable part 3b changes. For example, when hydraulic oil leaks in the direction of FIG. 3(a), the falling speed of the movable part 3b becomes faster. On the other hand, when hydraulic oil leaks in the direction of Fig. 3(b), the falling speed of the movable part 3b is further slowed.

In this way, when a command to move the spool 2a of the flow control valve 2 to the neutral position is received, by detecting the displacement of the movable part 3b of the actuator 3, whether or not the spool 2a is worn can judge Then, the state estimating part 5 estimates that the spool 2a is worn out, for example, when the displacement speed of the movable part 3b differs from the previously assumed displacement speed. Further, the greater the degree of wear of the spool 2a, the greater the change in the displacement speed of the movable portion 3b, so that the degree of wear of the spool 2a can also be estimated by the displacement rate of the movable portion 3b.

The fluid pressure drive device 1 in FIG. 2 may include a warning unit 11 indicated by a broken line. The warning unit 11 performs a predetermined warning process when the state estimation unit 5 determines that the displacement of the spool 2a has exceeded a predetermined threshold. Although the specific contents of the warning processing are arbitrary, for example, a warning signal is transmitted via a wireless or wired network to a management server (not shown) that manages the flow control valve 2, and the display device of the management server or the like. A warning may be displayed. Alternatively, the contents of the warning may be displayed or sounded out with a display device or speaker connected to the flow control valve 2 . An example of the warning content may be to prompt inspection of the spool 2a.

Thus, in the second embodiment, when a command to move the spool 2a of the flow control valve 2 to the neutral position is received, the displacement of the movable part 3b of the actuator 3 is detected, and the detected displacement It is possible to determine whether or not the spool 2a is worn, that is, whether leakage of hydraulic oil occurs when the spool 2a is in a neutral position, by comparing with the displacement when the spool 2a is not worn. In addition, the degree of wear of the spool 2a, that is, the amount of leakage of hydraulic oil, can be estimated by the size of the displacement of the movable part 3b.

(Third Embodiment)

3rd Embodiment predicts the life of the spool 2a of the flow control valve 2 based on the state estimated by the state estimation part 5.

4 is a diagram showing a schematic configuration of a fluid pressure drive device 1 according to a third embodiment. The fluid pressure drive device 1 of FIG. 4 includes a life predicting unit 12 in addition to the configuration of FIG. 2 .

The life predicting unit 12 predicts the life of the spool 2a based on the state of the spool 2a of the flow control valve 2 estimated over a predetermined period by the state estimating unit 5. In general, since the spool 2a gradually wears out during use, it is expected that the amount of hydraulic oil leaking when the spool 2a is in the neutral position will gradually increase. However, there may be cases in which the amount of leakage of hydraulic oil rapidly increases when a foreign substance contained in the hydraulic oil is rolled into the spool 2a. As the amount of leakage of hydraulic fluid increases, the displacement of the movable portion 3b of the actuator 3 also increases.

When the displacement of the spool 2a reaches a certain value, it is determined that the life of the spool 2a is different depending on the type or use of the flow control valve 2 and the like. Therefore, the life predicting unit 12 may provide a threshold for judging the life of the spool 2a. For example, the life predicting unit 12 may determine that the spool 2a has a life when the displacement speed of the spool 2a exceeds a threshold value.

In addition, the life predicting part 12 may judge that it is the life of the spool 2a at the point of time when the symptom that the leak amount of hydraulic oil rapidly increases is seen. More specifically, even though the displacement speed of the spool 2a tended to increase substantially linearly with the lapse of time, if the gradient at which the displacement speed increased at a certain point in time became larger, the spool 2a at that point in time It may be judged as the life of (2a).

In this way, the criterion for determining the life of the spool 2a by the life predicting unit 12 can be considered variously, but once it is determined that the life is the life, it is notified by some means that it is the replacement time of the spool 2a. It is desirable to do As for the notification method, various methods can be considered, similar to the warning processing by the warning unit 11 in FIG. 2 .

Further, the life predicting unit 12 may notify that the life of the spool 2a is approaching before reaching the life of the spool 2a, and may also provide information on when the life of the spool 2a will be reached at that time.

Thus, in 3rd Embodiment, since the life prediction part 12 which predicts the life of the spool 2a is provided based on the state estimated by the state estimation part 5, the use of the flow control valve 2 During operation, it is possible to prevent a state defect in which a large amount of hydraulic oil leaks. In addition, since the replacement timing of the spool 2a can be grasped without disassembling the flow control valve 2 and inspecting the spool 2a itself, the maintenance cost of the flow control valve 2 can be reduced.

(Fourth Embodiment)

In the fourth embodiment, the flow control valve 2 has a plurality of operation modes, one of which is a state estimation mode for estimating the state of the spool 2a, and when this state estimation mode is selected, the spool 2a ) to estimate the state of

5 is a diagram showing a schematic configuration of a fluid pressure drive device 1 according to a fourth embodiment. In the fluid pressure drive device 1 of FIG. 5 , in addition to the configuration of FIG. 4 , a mode selector 13 is provided in the controller 6 . In the fluid pressure drive device 1 according to the fourth embodiment, a mode selector 13 may be added to the configuration shown in FIG. 2 .

The mode selector 13 in the controller 6 can select any one of a plurality of operation modes. One of the plurality of operation modes is a state estimation mode for estimating the state of the spool 2a. Other than the state estimation mode, which operation mode to provide depends on the configuration and operation of the actuator 3. In this embodiment, the operation of the fluid pressure drive device 1 when the controller 6 selects the state estimation mode will be described.

When the controller 6 selects the state estimation mode, the controller 6 issues a command to move the spool 2a of the flow control valve 2 to the neutral position. In accordance with this command, with the spool 2a moved to the neutral position, the displacement detection unit 4 detects the displacement of the movable unit 3b of the actuator 3, and based on the detected displacement, the state estimation unit (5) estimates the state of the spool 2a. When the test mode is selected by the mode selector 13, the state estimating unit 5 moves the movable unit 3b to the neutral position and then moves the spool 2a to the neutral position, and moves the movable unit 3b The state of the spool 2a may be estimated in a state in which the control for feeding back the positional information to the flow control valve 2 is stopped.

Selection of the operation mode of the flow control valve 2 can be performed, for example by button operation or touch operation not shown. Therefore, the operator can select the state estimation mode with a simple operation. When the operator selects the state estimation mode, the spool 2a automatically moves to the neutral position, the displacement of the movable part 3b of the actuator 3 is detected, and the state of the spool 2a can be estimated.

In this way, in the fourth embodiment, since an operation mode for estimating the state of the spool 2a is provided, the operator simply selects this operation mode, the spool 2a automatically moves to the neutral position, and the actuator ( The displacement of the movable part 3b in 3) is detected, and the state of the spool 2a can be estimated based on the detected displacement. Thereby, the labor of the operator can be reduced, and the state of wear of the spool 2a can be investigated at an arbitrary timing as needed. Therefore, it is possible to detect abnormal wear of the spool 2a before the life of the spool 2a ends.

In each embodiment described above, the fluid pressure drive device 1 provided with the flow control valve 2 and the actuator 3 has been described, but the configuration and operation of the actuator 3 are arbitrary, so that the flow control valve It is widely applicable to the fluid pressure drive device 1 that performs various operations using hydraulic fluid discharged from (2). The flow control valve 2 should just have a spool 2a and control the discharge amount of hydraulic oil according to the position of the spool 2a. The specific example of the flow control valve 2 is applicable to a poppet valve, a ball valve, a needle valve, etc. other than the spool valve mentioned above. The actuator 3 has a movable part 3b whose position is variable according to the discharge amount of hydraulic oil from the flow control valve 2, and directly drives the actuator shaft according to the position of the movable part 3b, and the movable part 3b may be a valve that controls the supply amount of hydraulic fluid to the separately installed actuator 3 depending on the position. A specific example of the drive unit may be a spool valve or a poppet valve other than the actuator 3 of the movable unit 3b type described above, or may be a fluid pressure drive motor such as a hydraulic motor.

The technical idea of the embodiment described above can be summarized in the following (1) to (11).

(1) a first information acquisition unit that acquires a position of the first movable unit in a flow control valve that controls a discharge amount of a working fluid according to a position of the first movable unit;

a second information acquisition unit that acquires a position of the second movable unit in an actuator having a second movable unit that moves a position in accordance with the working fluid discharged from the flow control valve;

a state determination unit for determining whether or not the position of the first movable unit acquired by the first information acquisition unit is a neutral position at which supply of working fluid to the actuator is stopped;

A state estimating unit for estimating the state of the first movable unit based on the displacement per unit time of the second movable unit when the neutral position is determined by the state judging unit.

condition monitoring device.

(2) a detection unit for detecting that the first movable unit is positioned at the neutral position where supply of working fluid to the actuator is stopped;

The state determination unit determines that the position of the first movable unit is the neutral position when it is detected by the detection unit to be located in the neutral position.

The condition monitoring device described in (1).

(3) a detection unit for detecting a command to move the first movable unit to the neutral position;

The state monitoring device according to (1), wherein the state determination unit determines that the position of the first movable unit is the neutral position when the command is detected by the detection unit.

(4) a flow control valve for controlling the discharge amount of the working fluid according to the position of the first movable part;

an actuator having a second movable part that moves a position according to the working fluid discharged from the flow control valve;

a position detector for detecting a position of the second movable part;

Based on the displacement per unit time of the second movable part calculated from the position of the second movable part detected by the position detecting part in a state in which the supply of the working fluid from the flow control valve to the actuator is stopped, the first State estimator for estimating the state of the moving part

Equipped with a fluid pressure drive device.

(5) The displacement is at least one of the displacement speed of the second movable part and the time from when the second movable part receives a command to stop at a predetermined position until it starts to move,

The fluid pressure drive device described in (4).

(6) a warning unit for giving a predetermined warning when the displacement exceeds a predetermined threshold;

The fluid pressure drive device according to (4) or (5).

(7) a life predicting unit for predicting the life of the first movable unit based on the state of the first movable unit estimated over a predetermined period by the state estimating unit;

The fluid pressure drive device according to any one of (4) to (6).

(8) The actuator is arranged in a vertical direction,

The second movable part receives a command to stop the second movable part at a predetermined position and descends by its own weight in a state in which supply of working fluid from the flow control valve to the actuator is stopped.

The fluid pressure drive device according to any one of (4) to (7).

(9) When estimating the state of the first movable part, after the state estimating part moves the first movable part from the flow control valve to a position where supply of the working fluid to the actuator is stopped, to detect displacement

The fluid pressure drive device according to any one of (4) to (8).

(10) The actuator is a valve that controls the supply amount of working fluid to another actuator driven by the working fluid supplied from the actuator according to the position of the second movable part,

The fluid pressure drive device according to any one of (4) to (9).

(11) a mode selection unit capable of selecting a test mode for estimating the state of the first movable unit;

When the test mode is selected in the mode selection unit, the state estimation unit moves the second movable unit to a neutral position, moves the first movable unit to a neutral position, and obtains positional information of the second movable unit. Estimating the state of the first movable part in a state in which control for returning to the flow control valve is stopped,

The fluid pressure drive device according to any one of (4) to (10).

The aspects of the present invention are not limited to the above-described individual embodiments, but also 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 above-described contents. That is, various additions, changes, and partial deletions are possible without departing from the conceptual spirit and spirit of the present invention derived from the content stipulated in the claims and equivalents thereto.

1: fluid pressure drive device
2: flow control valve
3: Actuator
3a: sleeve
3b: moving part
4: displacement detector
5: state estimation unit
6: Controller
7: position detection unit
8: fuel injection valve
9: exhaust valve
10: position detection unit
11: warning part
12: life prediction unit
13: mode selector

Claims (8)

A flow control valve for controlling the discharge amount of the working fluid according to the position of the first movable unit;
an actuator having a second movable part that moves a position according to the working fluid discharged from the flow control valve;
an output unit outputting a command for moving the first movable unit to a neutral position;
a position detector for detecting the position of the second movable part when the command is output;
Displacement per unit time preliminarily assumed as the displacement per unit time of the second movable part calculated from the position of the second movable part detected by the position detection part only when the first movable part moves to the neutral position in accordance with the command. By comparing with, the state estimating unit for determining whether leakage of the working fluid has occurred, and estimating at least one state of whether or not the first movable part is worn and the degree of wear
Equipped with a fluid pressure drive device. According to claim 1,
A mode selection unit capable of selecting a test mode for estimating the state of the first movable unit,
The output unit outputs the command when the test mode is selected. According to claim 1,
The displacement is at least one of a displacement speed of the second movable part and a time period from receiving a command to stop the second movable part at a predetermined position until it starts to move. According to claim 1,
A fluid pressure drive device comprising: a warning unit for issuing a predetermined warning when the displacement exceeds a predetermined threshold. According to claim 1,
and a life predicting unit for predicting a life of the first movable unit based on the state of the first movable unit estimated over a predetermined period by the state estimating unit. According to claim 1,
The actuator is arranged in a vertical direction,
wherein the second movable part receives a command to stop the second movable part at a predetermined position and descends by its own weight in a state where supply of working fluid from the flow control valve to the actuator is stopped. According to claim 1,
When performing state estimation of the first movable part, the state estimating part detects the displacement of the second movable part after moving the first movable part from the flow control valve to a position where supply of the working fluid to the actuator is stopped. That is, a fluid pressure drive device. According to claim 4 or 5,
The actuator is a valve that controls a supply amount of a working fluid to another actuator driven by a working fluid supplied from the actuator according to a position of the second movable part.

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