CN113515148A

CN113515148A - Flow control device, flow control method, and computer-readable storage medium

Info

Publication number: CN113515148A
Application number: CN202110351161.5A
Authority: CN
Inventors: 冈本武史
Original assignee: Nabtesco Corp
Current assignee: Nabtesco Corp
Priority date: 2020-03-31
Filing date: 2021-03-31
Publication date: 2021-10-19
Also published as: JP2021162105A; KR20210122151A; KR102493759B1

Abstract

The invention provides a flow control device, a flow control method and a computer readable storage medium. A flow rate control device (100) for controlling the flow rate of a fluid supplied to an actuator by drive-controlling the actual position of a pilot valve element (12) to a target position, comprises: a first acquisition unit (31) that acquires an actual position (PVx) of the pilot valve spool (12) and a value of a flow rate-related parameter that is a parameter related to the flow rate of fluid that flows through the actuator when the pilot valve spool (12) is in the actual position; a second acquisition unit (32) that acquires a position command indicating a target position (PVs1) of the pilot valve element (12); a correction unit (36) that corrects the target position (PVs1) on the basis of the actual position and the value of the flow rate-related parameter; and a drive control unit (37) that drives the pilot valve element (12) in accordance with the corrected target position (PVs 2).

Description

Flow control device, flow control method, and computer-readable storage medium

Technical Field

The present invention relates to a flow rate control device, a flow rate control method, and a flow rate control program.

Background

Patent document 1 describes a servo control system including a servo system using feedback. The servo control system includes: a hydraulic cylinder controlled by a servo valve; a load operated by the hydraulic cylinder; and a controller providing a control input to eliminate a deviation between the cylinder stroke displacement and the target signal.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 3490561

Disclosure of Invention

Problems to be solved by the invention

The present inventors have obtained the following recognition of a flow rate control device that controls the flow rate of fluid supplied to an actuator by controlling the position of a valve element of a pilot valve. Even if the position of the valve body of the pilot valve is controlled in accordance with a position command from a host controller such as an engine control device, there is a problem that a desired flow rate of fluid does not flow to the actuator depending on the shape of the valve body.

In view of the above circumstances, an object of the present invention is to provide a flow rate control device capable of stably controlling the position of an actuator to a desired position according to the position of a spool of a pilot valve.

Means for solving the problems

A flow rate control device according to an aspect of the present invention controls a flow rate of a fluid supplied to an actuator by drive-controlling an actual position of a pilot valve spool, which is a valve spool of a pilot valve, to a target position, the flow rate control device including: a first acquisition unit that acquires an actual position of the pilot spool and a value of a flow rate-related parameter that is a parameter related to a flow rate of the fluid that flows through the actuator when the pilot spool is in the actual position; a second acquisition unit that acquires a position command indicating the target position of the pilot valve body; a correction unit that corrects the target position based on the actual position and the value of the flow rate-related parameter; and a drive control unit that drives the pilot valve element in accordance with the corrected target position.

Further, a mode in which the constituent elements or expressions of the present invention are replaced with each other among a method, an apparatus, a program, a transient or non-transient storage medium in which a program is recorded, a system, and the like is also effective as a mode of the present invention.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a flow rate control device capable of stably controlling the position of an actuator to a desired position according to the position of a spool of a pilot valve.

Drawings

Fig. 1 is a diagram schematically showing the configuration of the periphery of a valve control device of a hydraulic servo valve.

Fig. 2 is a diagram schematically showing the structure of the hydraulic servo valve.

Fig. 3 (a) to (c) are schematic diagrams schematically showing the positions of the valve elements of the pilot valve element and the open/close states of the ports.

Fig. 4 is a schematic configuration diagram illustrating the valve control device.

Fig. 5 (a) to (c) are diagrams showing states of the valve body and the second port of the pilot valve body at the neutral position.

Fig. 6 (a) to (c) are diagrams showing the correlation between the positions of the valve elements in fig. 5 (a) to (c) and the flow rate of the hydraulic oil supplied to the main valve, respectively.

Fig. 7 (a) to (c) are diagrams for explaining the principle that the amount of change in the flow rate of the hydraulic oil increases with respect to the position of the valve body 12a when the width of the valve body of the pilot spool is smaller than the opening width of the second port.

Fig. 8 is a flowchart showing the operation of the valve control device.

Fig. 9 is a flowchart showing the refresh operation of the valve control device.

Fig. 10 is a flowchart showing the operation of the valve control device.

Fig. 11 is a graph showing a correlation between the position of the valve body of the pilot spool and the moving speed of the main spool.

Fig. 12 is a schematic configuration diagram showing the valve control device.

Fig. 13 is a flowchart showing an estimated action of the valve control device.

Description of the reference numerals

30: an information processing unit; 31: a first acquisition unit; 32: a second acquisition unit; 33: a determination unit; 34: a correlation data generation unit; 35: an update unit; 36: a correction unit; 37: a drive control unit; 50: a storage unit; 100: a valve control device.

Detailed Description

In the following embodiments and modifications, the same or equivalent constituent elements and members are denoted by the same reference numerals, and overlapping descriptions are appropriately omitted. In addition, the dimensions of the components in the respective drawings are shown appropriately enlarged and reduced for easy understanding. In the drawings, some components that are not important in describing the embodiments are not shown.

[ first embodiment ]

Refer to fig. 1. The valve control device 100 can be used for controlling any control valve, but in the present embodiment, it controls the hydraulic servo valve 1 used in the engine 80 mounted on the ship. The valve control device 100 is an example of a flow rate control device.

The engine 80 mounted on the ship includes a plurality of cylinders 81. The hydraulic servo valve 1 is provided corresponding to each of the plurality of cylinders 81, and controls fuel injection, exhaust, and the like in each cylinder 81.

The engine control device 90 transmits a position command, which will be described later, to the valve control device 100 based on an engine output Hs (see fig. 4) input from a control panel (not shown) for controlling the voyage of the ship. Specific control performed by the engine control device 90 will be described later.

The valve control device 100 controls the position of a valve element of each pilot valve described later in response to a position command from the engine control device 90. Specific control performed by the valve control device 100 will be described later.

Refer to fig. 2. The hydraulic servo valve 1 includes a pilot valve 10 that controls the operation of an actuator by supplying hydraulic oil (fluid) 48, and a main valve 20 that is an example of the actuator. The pilot valve 10 and the main valve 20 are proportional control valves that control the pressure or flow rate of the output fluid in proportion to the input signal. In this case, the valve operates in proportion to the control amount, and therefore, stable feedback control can be realized.

The pilot valve 10 has a pilot valve spool 12. The pilot spool 12 moves and its position changes based on a command from the valve control device 100. The pilot valve 10 changes the flow rate of the hydraulic oil 48 supplied to the main valve 20 according to the position of the pilot valve spool 12.

The main valve 20 has a main spool 22. The main spool 22 moves according to the state of sending the hydraulic oil 48 from the pilot valve 10, and the position thereof changes. The main valve 20 changes the flow rate of the hydraulic oil 48 supplied to another actuator provided for driving an injection valve for injecting fuel into the engine 80, an exhaust valve for discharging air in the engine 80, and the like, in accordance with the position of the main spool 22. In other examples, main valve 20 may directly actuate an injection valve, an exhaust valve, etc. via movement of main poppet 22.

The hydraulic system of the main valve 20 comprises: a drain tank (drain tank)44 for storing working oil 48; and a hydraulic pump 42 that pumps the hydraulic oil 48 from the drain tank 44. The hydraulic oil 48 sent out by the hydraulic pump 42 is supplied to the interior of the main valve 20 and the pilot valve 10 through the pump-side piping portion 28p in the main valve 20. The hydraulic oil 48 discharged from the pilot valve 10 and the main valve 20 returns to the drain tank 44 through the tank-side pipe portion 28t in the main valve 20.

The pilot valve 10 includes a first position sensor 14s, a sleeve 16, and a spool drive 18. The pilot spool 12 has a plurality of

valve bodies

12p, 12a, 12t movable within a hollow sleeve 16. The valve body driving unit 18 includes a solenoid (not shown) that moves the pilot valve body 12 forward and backward in a first direction (the longitudinal direction of the pilot valve body 12 in fig. 1). The valve body drive unit 18 moves the pilot valve body 12 based on a command from the valve control device 100 to control the positions of the

valve bodies

12p, 12a, and 12 t. In this example, the three

valve bodies

12p, 12a, and 12t are arranged at positions where three first ports 16p, a second port 16a, and a third port 16t, which will be described later, can be opened and closed, respectively. The three

valve bodies

12p, 12a, 12t change the communication states of the three

ports

16p, 16a, 16t in accordance with the positions thereof. The width of the valve body 12a in the first direction (hereinafter referred to as the width) of the valve body 12a of the present embodiment is designed to be larger than the width of the second port 16a, in consideration of the change in shape with time due to wear of the valve body 12 a.

The sleeve 16 extends in a first direction for receiving the pilot spool 12. The sleeve 16 includes a first port 16p, a second port 16a, and a third port 16 t. The first port 16p is connected to the pump-side pipe portion 28p of the main valve 20 and receives the supply of the hydraulic oil 48 pressurized by the hydraulic pump 42. The first port 16p is used for feeding working oil 48 from the hydraulic pump 42. The second port 16a is connected to the hydraulic oil receiving portion 28a of the main valve 20. The second port 16a is used to supply the hydraulic oil 48 input from the first port 16p to the main valve 20. The third port 16t is connected to the tank-side piping portion 28t for discharging the working oil 48 flowing to the pilot valve 10 to the relief tank 44 through the tank-side piping portion 28 t. The third port 16t discharges the hydraulic oil 48 supplied to the main valve 20.

The first position sensor 14s detects the position of the pilot spool 12, and outputs the detection result (hereinafter referred to as "actual position PVx") thereof to the valve control device 100.

Main valve 20 includes a main spool 22 and a second position sensor 24s that captures the position of main spool 22. The main spool 22 moves based on the pressure of the hydraulic oil 48 supplied to the hydraulic oil accommodating portion 28a by the pilot valve 10, and changes the amount of fuel supplied to the engine 80. That is, the fuel supply amount to the engine changes according to the position of main spool 22.

The second position sensor 24s detects the position of the main spool 22, and outputs the detection result thereof (hereinafter referred to as "actual position MVx") to the engine control device 90 and the valve control device 100.

The positions of the valve elements of the pilot valve 10 and the open/close states of the ports corresponding to the positions will be described with reference to fig. 3 (a) to (c). Fig. 3 (a) shows a state in which the

valve bodies

12a, 12p are located in the first region that communicates the second port 16a with the first port 16 p. In this state, the second port 16a supplies the hydraulic oil 48 from the first port 16p to the hydraulic oil reservoir 28a (hereinafter referred to as "supply mode"). In the supply mode, the hydraulic oil 48 is supplied from the hydraulic pump 42 to the hydraulic oil reservoir 28a of the main valve 20 via the first port 16 p. By this operation, for example, main valve element 22 of main valve 20 moves in a direction (a direction opposite to the first direction in fig. 1) to increase the amount of fuel supplied to engine 80.

Fig. 3 (b) shows a state in which the valve body 12a is located in a neutral region (hereinafter, the position in the neutral region is also referred to as a "neutral position") in which the second port 16a is blocked and the first port 16p and the third port 16t are not communicated with the second port 16 a. The neutral position is a position that becomes the origin when the pilot spool 12 moves in the forward and backward direction. In this state, the second port 16a is blocked, and neither the supply of the hydraulic oil 48 nor the recovery of the hydraulic oil 48 is performed with respect to the hydraulic oil accommodating portion 28a (hereinafter, referred to as "neutral mode"). In the neutral mode, the hydraulic pressure of the hydraulic oil receiving portion 28a of the main valve 20 is maintained in a state immediately before the valve body 12a is located in the neutral region. By this operation, for example, the main spool 22 of the main valve 20 is stopped at a position immediately before the valve body 12a is located in the neutral region, and the fuel supply amount to the engine 80 is maintained in a state immediately before the valve body 12a is located in the neutral region.

Fig. 3 (c) shows a state in which the

valve bodies

12a, 12t are located in the second region that communicates the second port 16a with the third port 16 t. In this state, the second port 16a recovers the hydraulic oil 48 from the hydraulic oil accommodating portion 28a and returns the hydraulic oil 48 to the cabinet-side piping portion 28t (hereinafter referred to as "recovery mode"). In the recovery mode, the hydraulic oil 48 in the hydraulic oil receiving portion 28a of the main valve 20 is recovered to the drain tank 44 through the second port 16a, the third port 16t, and the tank-side pipe portion 28 t. By this operation, for example, main valve element 22 of main valve 20 moves in a direction (first direction in fig. 1) to reduce the amount of fuel supplied to engine 80.

The valve control device 100 will be explained. The functional blocks shown in fig. 4 can be realized by electronic components, mechanical components, and the like including a CPU of a computer in terms of hardware, and by computer programs and the like in terms of software. However, functional blocks realized by cooperation of hardware and software are depicted here. Thus, those skilled in the art will appreciate that these functional blocks can be implemented in various forms by a combination of hardware and software.

As shown in fig. 4, the valve control device 100 includes an information processing unit 30 in which a plurality of function blocks are integrated, and a storage unit 50. The information processing unit 30 includes a first acquisition unit 31, a second acquisition unit 32, a determination unit 33, a correlation data generation unit 34, an update unit 35, a correction unit 36, and a drive control unit 37. The storage unit 50 stores correlation data 51 and calibration data 52, which will be described later. In the present embodiment, the information processing unit 30 and the storage unit 50 are configured as an integrated module.

The first acquisition unit 31 acquires the actual position PVx of the pilot valve spool 12 from the first position sensor 14s provided in the pilot valve 10. The first acquisition unit 31 acquires the actual position MVx of the main spool 22 from the second position sensor 24s provided in the main valve 20.

For each actual position PVx, the first acquisition unit 31 acquires the value of the flow rate-related parameter relating to the flow rate of the hydraulic oil 48 that flows through the main valve 20. The flow rate-related parameter of the present embodiment is the moving speed of the main spool 22 in the first direction (hereinafter referred to as moving speed). The moving speed varies in proportion to the flow rate of the hydraulic oil 48 flowing through the main valve 20, and therefore is related to the flow rate of the hydraulic oil 48 flowing through the main valve 20. For each actual position PVx, the first acquiring unit 31 of the present embodiment acquires the travel speed based on the displacement of the actual position MVx of the main spool 22 acquired by the first acquiring unit 31. Specifically, the first acquisition unit 31 acquires the travel speed of the main spool 22 that is moved by the hydraulic oil 48 flowing out from the second port 16a when the pilot spool 12 is located at the actual position PVx.

The second acquisition unit 32 acquires a position command indicating the target position PVs of the pilot valve body 12 from the engine control device 90. The second acquisition unit 32 stores the target position PVs in the storage unit 50.

The determination unit 33 determines whether or not an update condition described later is satisfied.

The correlation data generating unit 34 generates update correlation data. The update correlation data indicates a correlation between each actual position PVx acquired by the first acquisition unit 31 when the pilot valve core 12 is moved in the forward and backward direction and the value of the parameter acquired for each actual position PVx. The correlation data 51 stored in the storage unit 50 also indicates the correlation.

The updating section 35 updates the correlation data 51 stored in the storage section 50 based on the actual position PVx of the pilot spool 12 acquired after the correlation data is generated and the value of the flow rate-related parameter with respect to the actual position PVx. The updating unit 35 updates the correlated data 51 using the correlated data for updating generated by the correlated data generating unit 34. The updating unit 35 updates the correction data 52 stored in the storage unit 50 based on the correlation data 51. The calibration data 52 of the present embodiment shows the corrected target position PVs2 corresponding to the pilot spool 12 for each target position PVs1 of the pilot spool 12. The method of updating the calibration data 52 according to the present embodiment will be described later.

The correction unit 36 corrects the target position PVs1 of the pilot valve spool 12 acquired by the second acquisition unit 32 based on the actual position PVx of the pilot valve spool 12 and the value of the flow rate-related parameter at the time of the actual position PVx. Specifically, the correcting unit 36 corrects the target position PVs1 using the correction data 52 generated based on the correlation data 51. Thus, the correcting unit 36 generates the corrected target position PVs2 of the pilot valve body 12 and outputs the target position PVs2 to the drive control unit 37.

The drive control unit 37 controls the operation of the pilot valve body 12. Specifically, the drive control unit 37 performs a predetermined arithmetic process based on the deviation between the corrected target position PVs2 of the pilot valve 12 and the actual position PVx acquired by the first acquisition unit 31, and generates a drive signal for the pilot valve 12. The valve body driving unit 18 receives a drive signal from the drive control unit 37, and drives the pilot valve body 12 based on the drive signal. The drive control unit 37 in the present embodiment performs feedback control including PID control based on the calculation result.

The pilot spool 12 is driven to move repeatedly in the forward and backward direction within the hollow sleeve 16. Therefore, when the pilot valve 10 is used for a long time, the pilot valve spool 12 is worn due to a frictional force between the pilot valve spool 12 and the inner wall of the hollow sleeve 16. The wear of the pilot valve element progresses in the order of fig. 5 (b), 5 (a), and 5 (c) described later. When the wear increases, foreign matter such as metal powder of the pilot valve core 12 may be mixed into the hydraulic oil 48. As a result, foreign matter in the hydraulic oil 48 may scrape and deform the pilot valve body 12 such as the pilot valve body 12. Further, the pilot valve core 12 may have a manufacturing error thereof.

As described above, the pilot valve core 12 has an individual shape that varies depending on the wear state, deformation, manufacturing error thereof, and the like. The shape of the pilot valve spool 12 (particularly, the valve body 12a for opening and closing the second port 16 a) affects the correlation between the flow rate of the hydraulic oil 48 supplied to the main valve 20 and the position of the pilot valve spool 12 as described later.

The reason why this correlation is affected will be described below with reference to fig. 5 (a) to (c) to fig. 7 (a) to (c). In fig. 5 (a) to (c), the center of the valve body 12a is located at a position coinciding with the center of the opening of the second port 16a in the first direction. Hereinafter, the position of the valve body 12a at this time is referred to as a "reference position". In fig. 6 (a) to (c), the horizontal axis indicates the position of the center of the valve body 12a, and the vertical axis indicates the flow rate of the hydraulic oil 48 flowing through the second port 16a to the main spool 22. The origin of the horizontal axis in (a) to (c) of fig. 6 indicates that the valve body 12a is located at the reference position.

In the example of fig. 5 (a), the width of the valve body 12a is equal to the opening width of the second port 16 a. In this case, at the reference position, the second port 16a is blocked by the valve body 12a, and the working oil 48 does not flow through the second port 16 a. On the other hand, if the valve body 12a is slightly moved from the reference position, the second port 16a becomes communicated with the other ports, and the working oil 48 circulates at the second port 16 a. As a result, as shown in fig. 6 (a), the flow rate of the hydraulic oil 48 supplied to the main valve 20 changes in proportion to the position of the valve element 12 a.

On the other hand, in the example of fig. 5 (b), the width of the valve body 12a is larger than the opening width of the second port 16 a. In this case, even if the valve body 12a moves from the reference position, the second port 16a does not immediately communicate with the other ports. As a result, the state in which the second port 16a is blocked by the valve body 12g continues. Therefore, as shown in fig. 6 (b), the flow rate of the hydraulic oil 48 supplied to the main valve 20 is 0 in a wide range of positions centered on the reference position. When the second port 16a communicates with another port by the movement of the valve body 12a, as shown in fig. 6 (b), the flow rate of the hydraulic oil 48 supplied to the main valve 20 changes in proportion to the position of the valve body 12 a.

In the example of fig. 5 (c), the width of the valve body 12a is smaller than the opening width of the second port 16 a. In this case, even in the case where the valve body 12a is located at the reference position, a gap is generated between the valve body 12a and the second port 16a, so that the second port 16a is slightly opened. In particular, when there are gaps on both sides of the valve body 12a in the first direction as shown in fig. 5 (c), the flow rate of the fluid flowing through the second port 16a increases as compared with the case where there is a gap on one side. As a result, as shown in fig. 6 (c), the amount of change in the flow rate of the hydraulic oil 48 corresponding to the position of the valve element 12a increases in the vicinity of the reference position where the clearance is generated on both sides of the valve element 12a, as compared with other cases.

The reason why the amount of change in the flow rate of the hydraulic oil 48 increases will be described with reference to (a) to (c) of fig. 7. The flow rate of the working oil 48 is determined by the sectional area of the gap between the valve body 12a and the second port 16 a. The cross-sectional area of the gap varies according to the width of the gap. As shown in fig. 7 (a), at a neutral position where a gap having a width of 1mm, for example, exists on both sides of the valve body 12a and the second port 16a, the working oil 48 having a flow rate corresponding to the gap having a width of 1mm, which passes through the gap on the first direction side, is discharged from the second port 16 a. On the other hand, the same flow rate of the working oil 48 corresponding to the gap having the width of 1mm passing through the gap on the opposite side is supplied to the second port 16 a. Therefore, the flow rate of the hydraulic oil 48 flowing through the second port 16a is 0.

A case where the valve body 12a is moved 0.5mm from the neutral position of fig. 7 (a) in the first direction will be described (fig. 7 (b)). In this case, the working oil 48 of a flow rate corresponding to the gap having the width of 0.5mm, which passes through the gap on the first direction side, is supplied from the second port 16a to the main spool. On the other hand, the working oil 48 of a flow rate corresponding to the gap having the width of 1.5mm, which passes through the gap on the opposite side, is discharged from the main spool to the drain tank via the second port 16 a. Therefore, the flow rate of the hydraulic oil 48 flowing through the second port 16a increases by the flow rate corresponding to the gap having the width of 1.0mm before and after the movement.

A case where the valve element 12a has moved 0.5mm in the first direction from a state where a gap exists on the opposite side of the valve element 12a from the first direction will be described (fig. 7 (c)). In this case, the flow rate of the working oil 48 flowing through the gap on the opposite side increases by the flow rate corresponding to the gap having a width of 0.5mm before and after the movement.

As described above, before and after the valve body 12a moves by 0.5mm, in the case of fig. 7 (c), the flow rate changes by the flow rate corresponding to the gap having the width of 0.5 mm. On the other hand, in the case of fig. 7 (b), the flow rate is changed by a flow rate corresponding to a gap having a width of 1.0 mm. Therefore, when the valve body 12a is moved, the amount of change in the flow rate of the working oil 48 differs between the two cases.

For comparison, a case where the correction unit 36 is not used will be described.

As described above, the valve control device 100 controls the position of the pilot spool 12 in response to the position command from the engine control device 90. If the correction unit 36 is not used, feedback control is performed based on the deviation between the target position PVs1 and the actual position PVx included in the position command.

However, when the shape of the valve body 12a of the pilot valve spool 12 is changed, the correlation between the flow rate of the hydraulic oil 48 supplied to the main valve 20 and the position of the pilot valve spool 12 is changed. For example, as described above, in a state where the width of the valve body 12a is larger than the opening width of the second port 16a as shown in fig. 5 (b), the hydraulic oil 48 is not supplied to the main valve 20 near the neutral position as shown in fig. 6 (b). Therefore, main spool 22 does not move. On the other hand, in a state where the width of the valve body 12a is smaller than the opening width of the second port 16a as shown in fig. 5 (c), the hydraulic oil 48 having a relatively large flow rate is supplied to the main valve 20 near the neutral position as shown in fig. 6 (c). Main spool 22 therefore moves substantially.

When the target position PVs1 of the pilot valve spool 12 set by the engine control device 90 is used as it is, the influence of the change in the correlation cannot be considered. For example, in a case where the target position is set in the engine control device 90 assuming the state shown in fig. 5 (b), a case where a relatively small amount of hydraulic oil 48 is supplied to the main spool 22 to move the main spool 22 a small amount may be considered. In this case, for example, in fig. 6 (b), a position in the vicinity of the rise in the flow rate from 0 is set as the target position. However, when the valve body 12a is in the state of fig. 5 (c), a large amount of hydraulic oil 48 is supplied to the main spool 22 at the target position as shown in fig. 6 (c). As a result, main spool 22 is caused to move substantially.

As described above, when the target position PVs1 is used as it is, the hydraulic oil 48 of the target flow rate is not supplied to the main valve 20, and the main spool 22 may not move to the target position PVs 1. As a result, there are the following problems: in order to eliminate the deviation from the target position PVs1, the response time of the feedback control becomes long, and the responsiveness of the control becomes poor. Therefore, it is desirable to perform feedback control in accordance with the state of the pilot spool 12.

The control loop of the feedback control of the engine control device 90 and the valve control device 100 will be described based on the above description.

First, the operation of the engine control device 90 will be described. Engine control device 90 determines a target position MVs of main spool 22 corresponding to a target engine output Hs. Engine control device 90 calculates target position PVs1 of pilot valve element 12 from the deviation between target position MVs of main valve element 22 and current actual position MVx of main valve element 22. The engine control device 90 transmits a position command indicating the calculated target position PVs1 of the pilot valve spool 12 to the valve control device 100. In this manner, the engine control device 90 performs feedback control of the position of the pilot valve element 12 based on the deviation between the target position MVs and the actual position MVx of the main valve element 22. As a result, the actual position MVx of the main spool 22 is controlled to follow the target position MVs.

Next, operation S10 performed by the information processing unit 30 of the valve control apparatus 100 will be described with reference to the flowchart of fig. 8. Act S10 is repeatedly performed at regular intervals (e.g., 10 msec).

The second acquisition unit 32 determines whether or not a position command indicating the target position PVs1 is acquired from the engine control device 90 (S11). If the position command has not been acquired (S11: NO), operation S10 is terminated. When the position command is acquired (S11: "YES"), the second acquisition unit 32 outputs the target position PVs1 indicated by the position command to the correction unit 36, and the operation S10 proceeds to S12. In the present embodiment, when the position command is acquired, the target position PVs1 is stored in the storage unit 50 in association with the hydraulic pressure of the hydraulic oil 48 supplied from the hydraulic pump 42 (hereinafter referred to as the supply hydraulic pressure). The supply hydraulic pressure in the present embodiment is acquired from the hydraulic pump 42 when the position command is acquired. The supply hydraulic pressure corresponds to the pressure applied by the fluid to the actuator.

Next, the correction unit 36 corrects the acquired target position PVs1 using the correction data 52 created based on the correlation data, thereby acquiring a corrected target position PVs2 (S12). The correction data 52 of the present embodiment is a data table in which the corrected target positions PVs2 are associated with each target position PVs 1. The correction unit 36 of the present embodiment uses the correction data 52 to acquire the corrected target position PVs2 by performing table processing using the acquired target position PVs1 as a key. Specifically, the correcting unit 36 extracts a corrected target position PVs2 corresponding to the acquired target position PVs1 from the data 52 for correction. The correction unit 36 acquires the extracted corrected target position PVs 2.

The first acquiring unit 31 acquires the actual position PVx of the pilot valve spool 12, and outputs the acquired actual position PVx to the drive control unit 37 (S13). The drive control unit 37 calculates a deviation between the actual position PVx from the first acquisition unit 31 and the corrected target position PVs2 (S14). Next, the drive control unit 37 outputs a drive signal to the valve body drive unit 18 based on the deviation calculated in S14, thereby performing feedback control on the position of the pilot valve body 12 (S15). After outputting the drive signal, the drive control unit 37 outputs a first determination instruction to the determination unit 33.

Next, the determination unit 33 determines whether or not the update condition is satisfied in response to the first determination instruction from the drive control unit 37 (S16). The determination unit 33 of the present embodiment determines, as the update condition, that the time transition of the position of the pilot valve core 12 shown in each of the plurality of position commands acquired from the engine control device 90 shows a predetermined pattern within a predetermined period until the position command is acquired in S11. The predetermined pattern is, for example, a pattern in which the pilot valve body 12 is repeatedly moved 10 times between the reference position and the position of ± 0.5mm from the reference position. If the update condition is not satisfied (S16: NO), the operation S10 is terminated. When the update condition is satisfied (yes in S16:), the determination unit 33 outputs an acquisition instruction to the first acquisition unit 31, and the operation S10 proceeds to S17.

Next, the first acquiring unit 31 acquires the actual position PVx and the movement speed after the control of S15 in response to the acquisition instruction from the determining unit 33, and outputs them to the correlation data generating unit 34 in association with each other (S17). In this step, the first acquisition unit 31 acquires the actual position PVx from the first position sensor 14s, and acquires the movement speed based on the actual position MVx acquired from the second position sensor 24 s.

Next, the correlation data generator 34 generates the update correlation data based on the correlated actual position PVx and the moving speed from the first acquirer 31 and the correlation data 51 stored in the storage unit 50, and outputs the update correlation data to the update unit 35 (S18). The update correlation data indicates the correlation between the movement speed at each position of the pilot spool 12. Specifically, the correlation data generator 34 replaces the moving speed at the position corresponding to the actual position PVx from the first acquirer 31 in the correlation data 51 stored in the storage 50 with the moving speed from the first acquirer 31. As a result, the actual position PVx and the corresponding moving speed from the first acquisition unit 31 are reflected in the generated update-related data.

Next, the updating unit 35 updates the correlated data 51 stored in the storage unit 50 using the update correlated data from the correlated data generating unit 34 (S19). In the updated correlation data 51, the movement speed is updated with the movement speed corresponding to the actual position PVx for the position corresponding to the actual position PVx acquired in S17.

Next, the updating unit 35 updates the correction data 52 based on the updated correlation data 51 (S20). The update operation of the correction data 52 according to the present embodiment will be described with reference to the flowchart of fig. 9. The updating unit 35 calculates the opening area of the second port 16a when the pilot spool 12 is located at the acquired target position PVs1 (S201). For example, the updating portion 35 calculates, as the opening area, the product of the dimension of the valve body 12a in the depth direction in fig. 5 and the dimension of the clearance between the valve body 12a and the second port 16a in the first direction in the case where the pilot valve spool 12 is located at the target position PVs 1. In the present embodiment, as the dimension of the valve body 12a in the depth direction in fig. 5, the dimension of the hollow portion of the sleeve 16 in the depth direction is used. The updating unit 35 acquires the supply hydraulic pressure corresponding to the acquired target position PVs1 from the storage unit 50 (S202). Next, the updating unit 35 calculates the estimated flow rate of the hydraulic oil 48 at the target position PVs1 based on the calculated opening area and the acquired supply hydraulic pressure (S203). The predicted flow rate is the flow rate predicted to be supplied to the main valve 20 at the target position PVs 1. Next, the updating unit 35 divides the calculated estimated flow rate of the hydraulic oil 48 by the cross-sectional area of the main valve element 22 to calculate the estimated moving speed of the main valve element 22 at the target position PVs1 (S204). The estimated travel speed is the estimated travel speed of main spool 22 when moving to target position PVs 1. Next, the updating unit 35 specifies the position of the pilot valve core 12 at the time of the movement speed that matches the calculated estimated movement speed from the correlation data 51 (S205). Next, the updating unit 35 updates the correction data 52 stored in the storage unit 50 with the determined position of the pilot spool as the corrected target position PVs2 corresponding to the target position PVs1 (S206). Based on the above, the update operation in S20 ends.

By using the correction data 52, the flow rate of the hydraulic oil 48 targeting the target position PVs1 can be realized from the corrected target position PVs 2. Further, according to this method, even in a state where the engine 80 is operating, the correction data 52 can be updated in accordance with the shape of the pilot valve core 12 at that time. Therefore, for example, during the course of the ship, the shape of the pilot spool 12 can be reflected on the corrected target position PVs2 in real time.

In addition, at the time of shipment of the hydraulic servo valve 1, the storage unit 50 stores in advance correlation data 51 and calibration data 52 created by experiments or simulations in advance. The same applies to the flow rate and the drive current as other examples of the flow rate-related parameter described in the following modifications.

After S20, act S10 ends.

In the present embodiment, the correcting unit 36 corrects the target position PVx based on the correlation data 51 indicating the correlation between the plurality of actual positions PVx and the values of the flow rate-related parameter acquired for each of the plurality of actual positions PVx. The flow rate-related parameter is a parameter related to the flow rate of the working oil 48 flowing through the actuator. The flow rate related parameter changes in accordance with the state of the pilot spool 12.

According to the present embodiment, the target position PVx is corrected in accordance with the flow rate of the hydraulic oil 48. Thus, even when the pilot valve core 12 is worn, deformed, and has a manufacturing error, the hydraulic oil 48 is supplied to the main valve 20 at a flow rate controlled in accordance with the state of the pilot valve core 12. Therefore, the position of main spool 22 can be stably controlled to a desired position.

In particular, for example, even when the pilot valve spool 12 is driven for a long time and the wear of the pilot valve spool 12 is increased in the order of (b) → (a) → fig. 6 (c), the target position is corrected in accordance with the shape after the wear. Therefore, the flow rate flowing through the main valve element 22 can be suppressed from largely deviating from the target flow rate, and therefore the main valve 20 can be stably controlled. Further, the supply amount of fuel injected to engine 80 and the exhaust gas amount of engine 80 can be stabilized.

In the present embodiment, the flow rate-related parameter in the present embodiment is a moving speed. According to this configuration, since the correlation data 51 can be acquired without using an additional sensor such as a flowmeter, an increase in manufacturing cost is suppressed.

In the present embodiment, the estimated flow rate of the hydraulic oil 48 is also calculated based on the hydraulic pressure of the hydraulic oil 48 supplied from the hydraulic pump 42. For example, due to wear or deformation of the pilot spool 12, for example, even in the neutral position, the working oil 48 may leak from a gap between the pilot spool 12 and the second port 16 a. According to this configuration, even when such leakage occurs, the position of main spool 22 can be controlled to a desired position with higher accuracy.

In the present embodiment, the first acquisition unit 31 acquires the actual position PVx when the pilot spool 12 is controlled in accordance with the corrected target position PVs2 and the moving speed when the pilot spool 12 is located at the actual position PVx, as in S17 of fig. 8. According to the present configuration, the correlation data generating unit 34 can generate the update correlation data using the actual position PVx and the movement speed after the feedback control acquired by the first acquiring unit 31. As a result, during the operation of the engine 80, the correlation data generation unit 34 can generate the update correlation data without performing a special operation other than the feedback control in the present embodiment. Therefore, even while engine 80 is operating, the correlation data generating unit 34 can generate the update correlation data while engine 80 is operating stably.

< modification example >

In the present embodiment, the correction data is used to acquire the corrected target position PVs2, but the present invention is not limited to this, and a correction formula indicating the correlation between the target position PVs1 and the corrected target position PVs2 may be used. Further, a correction model created by a known machine learning method such as a support vector machine, a neural network (including deep learning), or a random forest may be used.

The update condition in the present embodiment is a case where a signal formed by a position command group acquired within a predetermined period indicates a predetermined pattern, but is not limited to this. The update condition may be a case where the engine 80 to be supplied with fuel according to the position of the pilot valve body 12 is stopped. For example, when it is determined that main spool 22 stays at a position within a predetermined range where fuel cannot be supplied to engine 80 for a predetermined time or longer based on actual position MVx of main spool 22, it is determined that engine 80 is stopped. When the detection data (PVx, MVx) is acquired while the engine 80 is operating, an error in the detection data increases depending on an operating condition such as a response delay of engine control. By setting the engine stop state as the update condition, it is possible to suppress an error in the detection data, and to create the correlation data 51 and the correction data 52 with high accuracy.

Further, the adhesion prevention operation of the main valve 20 or the pilot valve 10 may be executed as the update condition. The adhesion prevention operation is an operation performed to prevent the valve element from being adhered due to solidification of the fluid in the main valve 20 or the pilot valve 10. In the sticking prevention action, for example, the spool periodically reciprocates to open and close the valve repeatedly. The sticking prevention action is sometimes referred to as a shaking action. Thereby, adhesion can be prevented by the adhesion preventing action, and probe data (PVx, MVx) can be acquired. By using the blocking prevention operation in this way, the operation for acquiring data can be used in combination, and therefore energy can be saved compared to the case of performing another operation.

In the present embodiment, the supply hydraulic pressure is obtained from the output value of the hydraulic pressure of the hydraulic pump 42, but a pressure gauge for measuring the supply hydraulic pressure may be used. In addition, the supply hydraulic pressure may be fixed in some cases, such as a case where a gap is not generated between the pilot spool 12 and the second port 16a in the neutral position. In this case, instead of using the output value of the hydraulic pressure of the hydraulic pump 42 when the position command is acquired, a constant such as a set value of the hydraulic pump 42 may be used.

The flow rate-related parameter in the present embodiment is a moving speed, but is not limited thereto. The flow rate-related parameter may be the flow rate of the hydraulic oil 48 supplied to the main valve 20. In this case, for example, a flow meter for measuring the flow rate of the hydraulic oil 48 supplied to the main valve 20 may be used. The flow rate may be calculated from the opening area of the second port 16a determined from the obtained moving speed and the positional relationship between the valve body 12a and the second port 16a at that time. According to this configuration, the target position is corrected based on the correlation between the position of the pilot spool 12 and the flow rate of the hydraulic oil 48 actually supplied to the main valve 20 at that position. Therefore, the main valve 20 can be controlled more accurately in correspondence with the shape of the pilot spool 12.

The flow rate-related parameter may be set as a drive current for driving the pilot spool 12. In this case, the pilot valve 10 may be provided with a current sensor that detects the value of the drive current flowing through the coil of the solenoid of the valve body drive unit 18 and transmits the detection result to the information processing unit 30.

In the present embodiment, the target position PVs1 is corrected based on the correction data 52, but the present invention is not limited to this. The correcting unit 36 may correct the target position PVs1 with a position corresponding to a moving speed that matches the estimated moving speed of the main spool 22 at the target position PVs1 in the correlation data 51 as the corrected target position PVs 2. In this case, the correcting unit 36 specifies the position of the pilot valve element 12 at the time of the movement speed that matches the estimated movement speed of the main valve element 22 at the time of the target position PVs1 by performing the same operations as those in S201 to S205 in fig. 9. Next, the correcting unit 36 may correct the target position PVs1 with the position of the pilot valve element 12 determined as the corrected target position PVs 2.

In the present embodiment, the corrected target position PVs2 is acquired by creating the correction data 52 based on the correlation data generated by the correlation data generation unit 34, but the present invention is not limited to this. For example, the corrected target position PVs2 may be acquired by creating the correction data 52 based on the actual position of the pilot spool 12 and the corresponding flow rate-related parameter without using the related data.

In the present embodiment, the information processing unit 30 and the storage unit 50 are integrally configured, but the information processing unit 30 and the storage unit 50 may be configured independently.

The update correlation data of the present embodiment is generated using the actual position PVx when the pilot spool 12 is controlled in accordance with the corrected target position PVs2, but is not limited thereto. For example, as long as the engine 80 is stopped, the update correlation data may be generated using the actual position PVx when the pilot spool 12 is controlled in accordance with the target position PVs 1.

Next, second to seventh embodiments of the present invention will be described.

[ second embodiment ]

A valve control device 100 according to a second embodiment will be described. In the second embodiment, the same or equivalent constituent elements and members as those of the first embodiment are denoted by the same reference numerals. The description overlapping with the first embodiment will be omitted as appropriate, and the description will focus on the structure different from the first embodiment.

In the first embodiment, the correction data 52 is updated every time the target position PVs1 is acquired in S10 of fig. 8, but the present invention is not limited to this. The second embodiment is different from the first embodiment in that the correction data 52 is updated by acquiring the corrected target position PVs2 for each target position PVs1 of the plurality of target positions PVs1 acquired during the predetermined period. The description will be made with reference to the flowchart of fig. 10.

As shown in fig. 10, after S31 to S34 similar to S11 to S14 described above have passed, drive controller 37 performs feedback control in the same manner as S15 in fig. 8 (S35). After outputting the drive signal, the drive control unit 37 outputs an acquisition instruction to the first acquisition unit 31.

The first acquiring unit 31 acquires the actual position PVx and the movement speed after the control of S35 in response to the acquisition instruction from the drive control unit 37, and stores them in the storage unit 50 in association with each other (S36). After the storage, the first acquiring unit 31 outputs a second determination instruction to the determining unit 33.

Next, the determination unit 33 determines whether or not the update condition is satisfied in response to the second determination instruction from the first acquisition unit 31 (S37). In this case, the update condition may be set to a condition that a predetermined period (one day, one week, or the like) has elapsed since the previous update. If the update condition is not satisfied (S37: NO), the operation S30 is terminated. When the update condition is satisfied (yes in S37), the determination unit 33 outputs a generation instruction to the correlation data generation unit 34, and the operation S30 proceeds to S38.

The correlated data generating unit 34 generates the update correlated data in response to the generation instruction from the determining unit 33 (S38). In this step, the correlation data generation unit 34 generates update correlation data based on each set of the actual position PVx and the movement speed stored in the storage unit 50 in association with each other. In the present embodiment, correlation data reflecting the movement speed corresponding to each target position PVs1 is obtained for each target position PVs1 acquired during a period from when the update condition is satisfied in the previous operation S30 to when the update condition is satisfied in the current operation S30.

Next, the updating unit 35 updates the correlated data 51 stored in the storage unit 50 using the correlated data for update (S39). S39 is the same as S19 in fig. 8, and therefore, the description thereof is omitted.

Next, the updating unit 35 updates the correction data 52 based on the updated correlation data 51 (S40). In the present embodiment, the updating unit 35 calculates the estimated movement speed of the main spool 22 for each target position PVs1 acquired from the time when the update condition was satisfied in the previous operation S30 to the time when the update condition was satisfied in the current operation S30. The updating unit 35 specifies the position of the pilot valve element 12 at the movement speed corresponding to each of the calculated estimated movement speeds. The updating unit 35 updates the correction data 52 stored in the storage unit 50 with the positions identified for the respective target positions PVs1 as corrected target positions PVs 2.

According to the configuration of the second embodiment, since all data obtained from the previous update to the current update is used at the time of update, the correlation data 51 and the calibration data 52 can be created with high accuracy.

[ third embodiment ]

A valve control device 100 according to a third embodiment will be described. In the third embodiment, the same or equivalent constituent elements and members as those of the second embodiment are denoted by the same reference numerals. The description overlapping with the second embodiment will be omitted as appropriate, and the description will focus on the structure different from the second embodiment.

In the second embodiment, in S38 of fig. 10, the correlation data is generated for each position corresponding to each target position PVs1 acquired during a predetermined period, but the present invention is not limited to this. The third embodiment is different from the first embodiment in that correlation data is generated based on a first position and a second position, which will be described later.

In S38 of fig. 10, the correlation data generation unit 34 acquires the first position and the second position of the pilot valve spool 12. For example, the correlation data generation unit 34 determines the actual position PVx of the pilot valve element 12 as the first position when the value of the flow rate-related parameter is within a predetermined low value range. The correlation data generation unit 34 determines the actual position PVx of the pilot valve element 12 as the second position when the value of the flow rate-related parameter is no longer within the predetermined low value range. The first position here is the position of the pilot spool 12 when the first port 16p is in communication with the second port 16 a. In addition, the second position is a position of the pilot spool 12 when the second port 16a communicates with the third port 16 t.

A method of determining the first position and the second position according to the present embodiment will be described with reference to fig. 11. As shown in fig. 11, the predetermined low value region is a predetermined low speed range including a moving speed of 0 m/s. The correlation data generation unit 34 determines the minimum value of the positions of the pilot valve element 12 in the correlation data 51, the movement speed of which is within a predetermined low value range, as the first position, and determines the maximum value as the second position. The predetermined low value region is appropriately determined based on 0m/s in consideration of a detection error of the actual position MVx for calculating the moving speed.

The correlation data generation unit 34 generates update correlation data based on the first position and the second position. Here, a method of generating update related data according to the present embodiment will be described. In this case, the correlation data is such that the moving speed is set to 0m/s for the position between the first position and the second position, and the moving speed is set to have a predetermined slope with respect to each position of the pilot spool 12 for the other positions. The predetermined slope is, for example, a slope of a moving speed at a position other than a position between the first position and the second position in the correlation data set at the time of shipment of the hydraulic servo valve 1.

The distance between the first position and the second position becomes smaller as the wear of the position of the pilot spool 12 increases. On the other hand, regarding the position of the pilot spool 12 other than the position between the first position and the second position, the moving speed changes in proportion to the position of the pilot spool 12. Therefore, even if the distance is small, the amount of change in the moving speed with respect to the change in the position is constant. In the present embodiment, the correlation data generation unit 34 generates the update correlation data from the first position and the second position using the relationship therebetween.

According to the present embodiment, the position of the pilot valve spool 12, which has not been acquired as the target position in the predetermined period, is also updated based on the first position and the second position. Therefore, in this position, the hydraulic oil 48 of a flow rate controlled in accordance with the shape of the pilot valve spool 12 is also supplied to the main valve 20. As a result, the position of main spool 22 can be controlled to a desired position with higher accuracy.

In the present embodiment, the relevant data is updated based on the first position and the second position, but the present invention is not limited to this. For example, the storage unit 50 stores in advance calibration data 52 that differs for each combination of the first position and the second position. The update unit 35 reads out the correction data 52 corresponding to the combination of the plurality of correction data 52 stored in the storage unit 50, using the combination of the first position and the second position as the search key. The updating unit 35 may update the correction data 52 using the read correction data.

[ fourth embodiment ]

A valve control device 100 according to a fourth embodiment will be described. In the fourth embodiment, the same or equivalent constituent elements and members as those of the third embodiment are denoted by the same reference numerals. The description overlapping with the third embodiment will be omitted as appropriate, and the description will focus on the structure different from the third embodiment.

In the present embodiment, the update condition in S37 in fig. 10 is a case where the time transition of the position of the pilot valve element 12 indicated by each of the plurality of position commands acquired from the engine control device 90 shows a predetermined pattern within a predetermined period until the position command is acquired in S37. The predetermined pattern is, for example, a pattern in which the movable range of the pilot valve body 12 is the reference position ± 1mm and the pilot valve body 12 is repeatedly moved 10 times between the reference position and the position of ± 50 μm. That is, the movable range of the pilot valve spool 12 with respect to the pilot valve spool 12 repeatedly moves in a minute section. Therefore, when the update condition is satisfied, in S36 of fig. 10, the first acquiring unit 31 acquires the movement speed of each actual position PVx for the minute section, and stores the acquired actual position PVx and the movement speed in the storage unit 50 in association with each other. The range in which the pilot valve core 12 is moved is not limited to the reference position ± 50 μm, and may be a range including the first position and the second position.

A method of determining the first position and the second position in the present embodiment will be described. In the present embodiment, the correlation data generator 34 calculates the slope of the movement speed at each position based on the actual position PVx and the movement speed stored in the storage unit 50 in association with each other in S36 of fig. 10. Here, the correlation data generation unit 34 calculates, for each position, an average value of the moving speed at the time of the positions of a plurality of points (for example, 100 points) before and after the position that is the object for calculating the slope. The correlation data generation unit 34 calculates the slope of the average value for each adjacent position. The correlation data generation unit 34 specifies the position where the difference between the calculated slope and the predetermined slope is smaller than the threshold value and the position closest to the reference position on the first direction side and the opposite side to the first direction side. The predetermined slope is set in the same manner as the predetermined slope used in the third embodiment. The correlation data generation unit 34 sets a position specified on the first direction side (negative direction of x-axis in fig. 6 (c)) as a first position, and sets a position specified on the opposite side of the first direction side (positive direction of x-axis in fig. 6 (c)) as a second position.

Next, an example of a method for generating update related data in the present embodiment will be described. The distance between the first position and the second position becomes smaller as the wear of the valve body 12a progresses from the state of fig. 5 (b), and then becomes 0 as shown in fig. 5 (a). Thereafter, when the wear of the valve body 12a is further increased and the width of the valve body 12a is smaller than the opening width of the second port 1a, the distance between the first position and the second position becomes larger again. Therefore, when the distance between the first position and the second position becomes 0 and then becomes larger again, the moving speed is set to have a predetermined slope with respect to each position of the pilot spool 12 for positions other than the position between the first position and the second position, and the moving speed is set to be 2 times the predetermined slope for the position between the first position and the second position. Thereby generating update related data. In this method, in an example of the above-described generation method, each point of the moving speed with respect to the first position and the second position needs to be located at a point symmetrical position with respect to the origin on the graph. This is because, when the moving speed is not at a point-symmetric position, correlation data that can connect points of the moving speed with respect to the first position and the second position on the graph cannot be obtained.

Next, another example of the method for generating the update related data in the present embodiment will be described. In the present embodiment, the flow rate at the specified position between the first position and the second position is stored in the storage portion 50 by driving the pilot valve element 12 in a predetermined pattern in S36 of the present embodiment. Therefore, the moving speed of each position stored in the storage unit 50 is used. The moving speed is set to have a predetermined slope with respect to each position of the pilot spool 12 for positions other than the position between the first position and the second position. According to this generation method, even when each point of the moving speed with respect to the first position and the second position is not at a position point-symmetric with respect to the origin due to uneven wear of the pilot spool 12, a detection error of the moving speed, or the like, it is possible to obtain correlation data such that these points can be connected on the graph.

As described above, the correlation data generating unit 34 of the present embodiment generates the update correlation data.

In a third embodiment, the value of the flow-related parameter is determined based on a prescribed low value region. However, when the width of the valve body 12a is smaller than the opening width of the second port 1a as shown in fig. 5 (c), the value of the flow rate-related parameter greatly increases near the neutral position as shown in fig. 6 (c). Therefore, since the value of the flow rate-related parameter immediately increases beyond the prescribed low value region in the vicinity of the neutral position, the first position and the second position cannot be accurately determined. According to the present embodiment, even in the case where the width of the valve body 12a is smaller than the opening width of the second port 1a, the first position and the second position can be determined. In addition, the first distance and the second distance can be determined by repeatedly moving the pilot spool 12 only in a minute section with respect to the movable range of the pilot spool 12. Therefore, energy saving can be achieved as compared with the case where the pilot valve spool 12 is moved within the movable range of the pilot valve spool 12.

[ fifth embodiment ]

A valve control device 100 according to a fifth embodiment will be described. In the fifth embodiment, the same or equivalent constituent elements and members as those of the first embodiment are denoted by the same reference numerals. The description overlapping with the first embodiment will be omitted as appropriate, and the description will focus on the structure different from the first embodiment.

As shown in fig. 12, the information processing section 30 further includes a third acquisition section 61, an estimation section 62, an output section 63, and a wireless communication section 64.

In the present embodiment, the third acquisition unit 61 specifies the first position and the second position based on the correlation data 51, as in the third embodiment. In addition, the third acquisition section 61 acquires the first distance by calculating the first distance between the first position and the second position.

The estimation unit 62 estimates the state of the pilot spool 12 based on a comparison between the first distance calculated by the third acquisition unit 61 and a reference value. The reference value of the present embodiment is a first distance (for example, a first distance at the time of shipment or the like) initially calculated for the pilot valve body 12. The state of the pilot valve core 12 of the present embodiment is the degree of wear of the pilot valve core 12.

The output unit 63 outputs the estimation result of the estimation unit 62. When the first distance is equal to or less than the reference value, the output unit 63 notifies that replacement of the pilot valve 10 is recommended.

The wireless communication unit 64 performs wireless communication with the outside. For example, the wireless communication unit 64 wirelessly communicates with the remote controller 40 for remotely operating the valve control device 100 from the outside.

Operation S50 of the valve control device 100 according to the present embodiment will be described with reference to fig. 13. The determination unit 33 determines whether or not the estimation condition is satisfied (S51). The estimation condition in the present embodiment is that a predetermined period (one day, one week, etc.) has elapsed since the previous estimation. However, the estimation condition is not limited to this, and may be a case where the update condition is satisfied.

If the estimation condition is not satisfied (S51: NO), the operation S50 is ended. When the estimation condition is satisfied (yes in S51:), the determination unit 33 outputs a calculation instruction to the third acquisition unit 61, and the operation S50 proceeds to S52.

In S52, the third acquisition section 61 calculates a first distance between the first position and the second position based on the correlation data 51. The first position and the second position are determined by the same method as that described in the third embodiment. The third acquisition unit 61 outputs the calculated first distance to the estimation unit 62.

Next, the estimating unit 62 determines whether or not the first distance calculated by the third acquiring unit 61 is equal to or less than a reference value (S53).

If the calculated first distance is greater than the reference value (S53: no), operation S50 proceeds to S54. If the calculated first distance is equal to or less than the reference value (S53: yes), operation S50 proceeds to S55.

In S54 and S55, the estimation section 62 estimates the state of the pilot spool 12 based on the comparison of the first distance with the reference value. Specifically, the estimation unit 62 estimates the degree of wear of the pilot spool 12 based on the difference between the first distance and the reference value. After S54, the estimating unit 62 outputs the estimation result to the output unit 63, and the operation S50 proceeds to S56. After S55, the estimating unit 62 outputs the estimation result and the notification instruction to the output unit 63, and the operation S50 proceeds to S57.

In S56 and S57, the output section 63 outputs the estimation result of the state of the pilot spool 12. Specifically, the output unit 63 outputs the estimation result to the remote controller 40 via the wireless communication unit 64. As a result, the estimation result is displayed on the display of the remote controller 40. The output unit 63 may display the estimation result on a display, not shown, provided in the pilot valve 10, the valve control device 100, or the like. After S56, act S50 ends. After S57, act S50 proceeds to S58.

In S58, the output unit 63 notifies that replacement of the pilot valve 10 is recommended based on the notification instruction from the estimation unit 62. For example, the output unit 63 outputs a notification signal to the remote controller 40 via the wireless communication unit 64, and causes the display of the remote controller 40 to display a message indicating that replacement of the pilot valve 10 is recommended. The output unit 63 may cause the remote controller 40 to generate a voice to the effect of the above-described advice. After S58, act S50 ends.

Here, when the operation of the hydraulic servo valve 1, the engine 80, and the like is unstable, it is easy to determine abnormality or deterioration such as wear and deformation of the pilot valve body 12 from data and the like relating to the operation. On the other hand, in the valve control device 100, as described above, the target position PVs is corrected in accordance with the state of the pilot valve spool 12. Therefore, even in a state where the wear of the pilot valve core 12 actually increases, the hydraulic servo valve 1, the engine 80, and the like stably operate. Therefore, in the valve control device 100, it is difficult to determine abnormality or deterioration such as wear or deformation of the pilot valve body 12. As a result, although the hydraulic servo valve 1, the engine 80, and the like are operated stably up to now, they may suddenly stop operating normally.

Further, according to the present embodiment, when the first distance is equal to or less than the reference value, an alarm is generated to suggest replacement of the pilot valve 10. Therefore, the pilot valve 10 can be replaced at an appropriate replacement timing. As a result, the hydraulic servo valve 1, the engine 80, and the like are prevented from suddenly stopping operating normally.

In the present embodiment, the reference value to be compared with the first distance is the first distance that is acquired for the pilot valve body 12 first. According to this structure, it is possible to accurately estimate the wear of the pilot valve spool 12 from the time when the hydraulic servo valve 1 starts to be used.

The reference value in the present embodiment is the first distance calculated for the pilot valve body 12 at first, but is not limited to this. The reference value may be set based on the first distance calculated at the same timing for the pilot valve core 12 of the hydraulic servo valve 1 corresponding to the other cylinder 81. For example, the reference value may be an average value of the first distances calculated at the same timing for the pilot valves 10 of the hydraulic servo valves 1 corresponding to the other cylinders 81. In this case, the relative size of the width of the target pilot valve body 12 with respect to the width of the pilot valve body 12 of the hydraulic servo valve 1 corresponding to the other cylinder 81 can be grasped. As a result, the state of the target pilot valve core 12 can be accurately estimated.

The reference value may be set as appropriate according to the purpose, and is, for example, a value equal to the opening width of the second port 16 a.

In the present embodiment, the estimation unit 62 estimates the state of the pilot valve spool 12 based on the first distance, but is not limited thereto. The estimation unit 62 may estimate the state of the pilot valve body 12 based on at least one of the first position, the second position, and the first distance. In this case, the reference values are determined for the first position, the second position, and the first distance, respectively. For example, the estimation unit 62 may estimate the state of the pilot valve spool 12 based on a difference between the first position and a reference value determined for the first position. In this case, the reference value may be the first position initially determined for the pilot spool 12. The second position may also be used for the estimation as the first position. The third acquiring unit 61 may acquire at least one value of the first position, the second position, and the first distance.

[ sixth embodiment ]

The sixth embodiment is a flow rate control method of a hydraulic servo valve. The control method of the present invention can be used for various hydraulic servo valves, but in the present embodiment, a flow rate control method for controlling the flow rate of the fluid supplied to the actuator by drive-controlling the actual position of the pilot valve core 12 of the pilot valve 10 to the target position is exemplified.

The flow control method comprises the following steps: acquiring an actual position of the pilot spool 12 and a value of a flow-related parameter that is a parameter related to a flow rate of fluid that flows through the actuator when the pilot spool 12 is in the actual position; acquiring a position command indicating a target position of the pilot spool 12; correcting the target position based on the value of the flow-related parameter; and driving the pilot spool 12 in accordance with the corrected target position. The fluid control method can be implemented by the valve control device 100.

The configuration according to the sixth embodiment provides the same operation and effect as those of the first embodiment.

[ seventh embodiment ]

A seventh embodiment is a flow rate control program (computer program) for a hydraulic servo valve. The control program of the present invention can be used for various hydraulic servo valves, but in the present embodiment, a computer program for controlling the flow rate of the fluid supplied to the actuator by controlling the actual position drive of the pilot valve core 12 of the pilot valve 10 to the target position is exemplified.

The computer program can cause a computer of the flow rate control apparatus to function as: a first acquisition unit 31 that acquires an actual position of the pilot spool 12 and a value of a flow rate-related parameter that is a parameter related to the flow rate of fluid that flows through the actuator when the pilot spool 12 is in the actual position; a second acquisition unit 32 that acquires a position command indicating a target position of the pilot valve body 12; a correction unit 36 that corrects the target position based on the value of the flow rate-related parameter; and a drive control unit 37 that drives the pilot valve body 12 in accordance with the corrected target position.

The computer program may be installed in a storage device (for example, the storage unit 50) of the valve control device 100 as an application program in which a plurality of modules corresponding to the functional blocks of the valve control device 100 are installed. The computer program may be read out into a main memory of a processor (e.g., CPU) of the valve control apparatus 100 to be executed.

The configuration according to the seventh embodiment provides the same operation and effect as those of the first embodiment.

The embodiments of the present invention have been described in detail. The above embodiments are merely specific examples for carrying out the present invention. The contents of the embodiments are not intended to limit the scope of the present invention, and many design changes such as changes, additions, deletions, and the like of the constituent elements can be made without departing from the scope of the inventive concept defined in the claims. In the above-described embodiments, the description has been given with the expressions "of the embodiments" and "in the embodiments" regarding the contents that can be subjected to such a design change, but it is not permissible to subject the contents that are not subjected to such an expression to a design change.

Any combination of the above-described embodiments and modifications is also useful as an embodiment of the present invention. The new embodiment resulting from the combination has the effects of both the combined embodiment and the modified example.

Industrial applicability

Claims

1. A flow rate control device that controls a flow rate of a fluid supplied to an actuator by drive-controlling an actual position of a pilot valve core, which is a valve core of a pilot valve, to a target position, the flow rate control device comprising:

a first acquisition unit that acquires an actual position of the pilot spool and a value of a flow rate-related parameter related to a flow rate of the fluid flowing through the actuator when the pilot spool is at the actual position;

a second acquisition unit that acquires a position command indicating the target position of the pilot valve body;

a correction unit that corrects the target position based on the actual position and the value of the flow rate-related parameter; and

and a drive control unit that drives the pilot valve body in accordance with the corrected target position.

2. The flow control device of claim 1,

the actuator is a main valve having a main spool that is a spool moved by the fluid supplied from the pilot valve,

the flow related parameter is a speed of movement of the main spool.

3. The flow control device of claim 1,

the flow-related parameter is a flow rate of the fluid supplied to the main valve.

4. The flow control device of claim 1,

the flow rate-related parameter is a drive current flowing through a solenoid for driving the pilot valve spool or a drive voltage applied to the solenoid.

5. The flow control device according to any one of claims 1 to 4,

further included is a correlation data generation unit that generates correlation data representing correlations between a plurality of actual positions of the pilot spool and values of the flow rate related parameter acquired for each of the plurality of actual positions.

6. The flow control device of claim 5,

the correction portion calculates a predicted flow rate of the fluid, which is predicted as a flow rate of the fluid supplied to the main valve with the pilot valve spool at the target position, based on the target position,

the correction section calculates a value of a flow rate-related parameter estimated with the pilot valve element located at the target position, based on the estimated flow rate calculated,

the correction unit corrects the target position by using the actual position corresponding to the value of the flow rate-related parameter that matches the value of the estimated flow rate-related parameter in the correlation data as the corrected target position.

7. The flow control device of claim 6,

the correction portion further calculates the estimated flow based on a pressure applied by the fluid to the main valve.

8. The flow control device according to any one of claims 5 to 7,

the correlation data generation portion determines a first position of the pilot spool when a first port for inputting the fluid is communicated with a second port for supplying the fluid input from the first port to the actuator and a second position of the pilot spool when a third port for discharging the fluid supplied to the actuator is communicated with the second port,

the correlation data generation unit acquires the correlation data based on the first position and the second position.

9. The flow rate control device according to any one of claims 5 to 8, further comprising:

a storage unit that stores the related data; and

an updating section that updates the correlation data stored in the storage section based on the actual position acquired after the correlation data is generated and the value of the flow rate-related parameter with respect to the actual position,

wherein the correction section corrects the acquired target position based on the updated correlation data.

10. The flow control device according to any one of claims 5 to 9,

the correlation data generation unit generates the correlation data when a predetermined condition is satisfied.

11. The flow control device of claim 10,

the predetermined condition includes that an adhesion preventing action of the pilot valve element is executed.

12. The flow control device of claim 10,

the predetermined condition includes an engine stop to which fuel is supplied according to a position of the pilot valve element.

13. The flow control device of claim 12,

the predetermined condition includes that the main spool stays at a position where the fuel is not supplied to the engine for a predetermined time or longer.

14. The flow control device of any one of claims 1 to 13,

the first acquisition unit acquires the actual position when the pilot valve element is controlled in accordance with the corrected target position, and the value of the flow rate-related parameter when the pilot valve element is located at the actual position.

15. The flow control device according to any one of claims 1 to 14, further comprising:

a third acquisition unit that acquires, based on the actual position and a value of the flow rate-related parameter at the actual position, at least one of a first position that is a position of the pilot spool when a first port for inputting the fluid is communicated with a second port for supplying the fluid input from the first port to the actuator, a second position that is a position of the pilot spool when a third port for discharging the fluid supplied to the actuator is communicated with the second port, and a distance between the first position and the second position; and

and an estimation unit that estimates a state of the pilot valve body based on a comparison between the at least one value and a reference value.

16. The flow control device of claim 15,

the value of the at least one party is the distance,

the control device further includes a notification unit configured to notify that replacement of the pilot valve is recommended when the distance is equal to or less than the reference value.

17. A flow rate control method for controlling a flow rate of a fluid supplied to an actuator by controlling a position of a pilot spool as a spool of a pilot valve, the flow rate control method comprising the steps of:

obtaining an actual position of the pilot spool and a value of a flow-related parameter related to a flow rate of the fluid flowing through the actuator when the pilot spool is in the actual position;

acquiring a position command representing a target position of the pilot valve core;

correcting the target position based on the value of the flow-related parameter; and

and driving the pilot valve spool according to the corrected target position.

18. A computer-readable storage medium storing a flow rate control program capable of causing a computer of a flow rate control device that controls a flow rate of a fluid supplied to an actuator by controlling a position of a pilot valve body that is a valve body of a pilot valve to execute a first acquisition step, a second acquisition step, a correction step, and a drive control step, wherein,

in the first acquisition step, an actual position of the pilot spool and values of a flow rate-related parameter that is related to a flow rate of the fluid that flows through the actuator when the pilot spool is at the actual position are acquired,

in the second acquiring step, a position command indicating a target position of the pilot spool is acquired,

in the correcting step, the target position is corrected based on the value of the flow rate-related parameter,

in the drive control step, the pilot valve element is driven in accordance with the corrected target position.

19. A flow rate control device that controls a flow rate of a fluid supplied to a main valve having a main valve element that is moved by the fluid supplied from a pilot valve by drive-controlling an actual position of the pilot valve element as a valve element of the pilot valve to a target position, the flow rate control device comprising:

a first acquisition unit that acquires an actual position of the pilot valve element and a moving speed of the main valve element when the pilot valve element is at the actual position;

a correlation data generation unit that generates correlation data indicating a correlation between a plurality of actual positions of the pilot valve element and the movement speed acquired for each of the plurality of actual positions;

a correcting section that corrects the target position based on the correlation data;

a drive control unit that drives the pilot valve element in accordance with the corrected target position;

a third acquisition unit that acquires, based on the actual position and the movement speed at the actual position, a distance between a first position and a second position, the first position being a position of the pilot spool when a first port for inputting the fluid and a second port for supplying the fluid input from the first port to the main valve and the second position being a position of the pilot spool when a third port for discharging the fluid supplied to the main valve and the second port are communicated;

an estimation unit that estimates a state of the pilot valve body based on a comparison between the distance and a reference value; and

and a notification unit configured to notify that replacement of the pilot valve is recommended when the distance is equal to or less than the reference value.