JP6546307B1 - Marine fluid pump and control method thereof - Google Patents

Abstract

A marine fluid pump and a control method therefor are capable of accurately controlling a movement amount of a piston when a fluid is pressurized and discharged while suppressing an increase in cost. A marine fluid pump according to one aspect of the present invention includes a pump body that pressurizes and discharges fluid by moving a piston using pressure of hydraulic fluid, and a maximum displacement of the piston in one fluid discharge. , A control valve that selectively switches between an on state for supplying hydraulic oil to the pump body and an off state for stopping the supply of hydraulic oil, and a control unit. The control unit derives a target movement amount of the piston according to the fluid discharge amount required in one fluid discharge, and the target movement amount in the current fluid discharge and the maximum movement amount in the previous fluid discharge Based on this difference, calculate a time correction value for the valve on time of the control valve, and take this time correction value into account to correct the valve on time during the current fluid discharge, and continue the valve on time after correction Then, the control valve is controlled so as to be turned on. [Selected figure] Figure 1

Description

  The present invention relates to a marine fluid pump and a control method thereof.

  Conventionally, a marine fluid pump for discharging a fluid such as fuel or water has been applied to a marine diesel engine mounted on a ship. For example, as a marine fluid pump, a fuel injection pump is used to pressure-feed fuel injected into a cylinder to a fuel injection valve, and water is injected into a fuel flow passage from the discharge port of the fuel injection pump to the injection port of the fuel injection valve through piping. A water injection pump etc. are mentioned. Patent Document 1 describes a fuel injection pump driven and controlled by hydraulic oil supplied via a solenoid valve.

  In general, a marine fluid pump internally includes a piston in a state capable of reciprocating in the longitudinal direction, and pressurizes fluid by moving the piston using the pressure of hydraulic fluid supplied via a control valve. Discharge. The discharge amount of the fluid by such a marine fluid pump increases or decreases in accordance with the movement amount of the piston at the time of pressurizing and discharging the fluid. Therefore, in the marine fluid pump, the displacement of the piston should be controlled with high accuracy from the viewpoint of securing the accuracy required for the discharge amount of fluid (for example, the fuel injection amount and the water injection amount in the marine diesel engine). Is required.

Patent No. 4176742

  In order to control the amount of movement of the piston described above with high accuracy, in most cases, an opening adjustment type solenoid valve such as a servo valve or proportional valve that can control the amount of hydraulic oil supplied with high accuracy by adjusting the opening. Is used as a control valve of a marine fluid pump. However, when an opening adjustment type solenoid valve is used as a control valve, in general, the measured value of the moving amount of the piston is frequently measured during the discharge period of the fluid, and in each case, the measured value of the moving amount of the piston is Since it is necessary to reflect the deviation from the target value in the adjustment of the degree of opening of the control valve, the device configuration for precisely controlling the amount of movement of the piston may be complicated and the cost of the device may be expensive. In addition to this, many of the solenoid valves of the opening adjustment type are susceptible to the entry of foreign matter, and it is easy to cause the entry of foreign particles under the environment where the marine diesel engine operates. Solenoid valves may not be suitable.

  The present invention has been made in view of the above circumstances, and it is possible to accurately control the amount of movement of the piston when pressurizing and discharging the fluid while suppressing an increase in cost, and It aims at providing the control method.

  In order to solve the problems described above and achieve the object, a marine fluid pump according to the present invention comprises a pump main body that pressurizes and discharges fluid by moving a piston using pressure of hydraulic oil, and A detection unit for detecting the maximum displacement of the piston in one discharge of fluid, and an on-state for supplying the hydraulic fluid to the pump body and an off-state for stopping the supply of the hydraulic fluid are alternatively switched. The target movement amount of the piston is derived according to the control valve and the discharge amount of the fluid required in one discharge of the fluid, and the target movement amount derived in the current discharge of the fluid and the previous movement amount Based on the difference from the maximum movement amount detected at the time of discharge, a time correction value of valve on time, which is a time for turning on the control valve, is calculated, and the calculated time correction value is calculated. In addition, this discharge of the fluid this time The valve on-time is corrected at the time of, characterized in that it comprises a control unit for controlling the control valve so as to continue said valve on-time after correction becomes the ON state.

  Further, in the marine fluid pump according to the present invention, in the above invention, the control unit derives a valve on basic time which is a valve on time of the control valve set according to the target movement amount of the piston. The valve on time at the current discharge of the fluid is corrected to be a time obtained by adding the valve on basic time and the time correction value.

  Further, in the marine fluid pump according to the present invention, in the above-mentioned invention, the control unit has a data table indicating a correlation between the target moving amount of the piston and the valve on basic time of the control valve, The valve-on basic time correlated with the target movement amount derived at the current discharge of the fluid is derived based on the data table.

  Further, in the control method of a marine fluid pump according to the present invention, the pump body may be selectively switched between an on-state for supplying the hydraulic fluid to the pump body and an off-state for stopping the supply of the hydraulic fluid. In a control method of a marine fluid pump for pressurizing and discharging a fluid by supplying a hydraulic fluid to the fluid and moving a piston of the pump body using a pressure of the fluid that is supplied, the fluid once A target movement amount deriving step for deriving a target movement amount of the piston according to the discharge amount of the fluid required for the ejection of the fluid; and the previous movement amount of the fluid and the target movement amount of the piston by the target movement amount derivation step Time correction value calculation procedure for calculating a time correction value of a valve on time which is a time for bringing the control valve into the on state based on a difference from the maximum movement amount of the piston in discharge And the correction step of correcting the valve on time at the time of the current discharge of the fluid in consideration of the time correction value by the time correction value calculating step, and the valve on time after correction being continued continuously. And controlling the control valve so as to be in a state.

  Further, in the control method of a marine fluid pump according to the present invention according to the above-mentioned invention, the correction step is a valve on basic time which is a valve on time of the control valve set according to the target movement amount of the piston. To correct the valve on time at the current discharge of the fluid to be the time obtained by adding the valve on basic time and the time correction value.

  In the control method of a marine fluid pump according to the present invention, in the above-mentioned invention, the correction step is based on a data table indicating a correlation between the target movement amount of the piston and the valve on basic time of the control valve. And deriving the valve-on basic time correlated with the target moving amount in the target moving amount deriving step.

  According to the present invention, the amount of movement of the piston of the marine fluid pump at the time of pressurizing and discharging the fluid can be controlled with high accuracy while suppressing an increase in cost.

FIG. 1 is a schematic view showing a configuration example of a marine fluid pump according to an embodiment of the present invention. FIG. 2 is a diagram for explaining the on state and the off state of the control valve in the embodiment of the present invention. FIG. 3 is a flow chart showing an example of a control method of the marine fluid pump according to the embodiment of the present invention. FIG. 4 is a view specifically explaining a control method of the marine fluid pump according to the embodiment of the present invention.

  Hereinafter, preferred embodiments of a marine fluid pump and a control method thereof according to the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited by the present embodiment. In addition, it should be noted that the drawings are schematic, and dimensional relationships among elements, ratios of elements, and the like may differ from actual ones. Even between the drawings, there may be a case where the dimensional relationships and ratios differ from one another. Further, in the drawings, the same components are denoted by the same reference numerals.

(Configuration of marine fluid pump)
FIG. 1 is a schematic view showing a configuration example of a marine fluid pump according to an embodiment of the present invention. In this embodiment, the case where this marine fluid pump 10 is a water injection pump for injecting water into the fuel flow passage of a marine diesel engine (not shown) is exemplified. Although not particularly shown, the fuel flow passage of the marine diesel engine is a flow passage of fuel from the discharge port of the fuel injection pump to the injection port of the fuel injection valve through piping. The fuel injection pump is a device for injecting fuel through piping or the like to a fuel injection valve for injecting fuel into a cylinder of a marine diesel engine.

As shown in FIG. 1, the marine fluid pump 10 includes a pump body 1 that discharges water, which is an example of a fluid, and a detection unit 6 that detects a maximum lift amount L _m (n) of the piston 2 of the pump body 1; A control valve 7 for supplying and discharging hydraulic oil to and from the pump body 1 and a control unit 11 for controlling the control valve 7 are provided. In addition, in FIG. 1, a solid line arrow shows circulation of fluid, such as hydraulic fluid, and a dashed dotted line arrow shows an electrical signal line.

  The pump body 1 is a hydraulically driven pump device that discharges a fluid (water in this embodiment) using the pressure of hydraulic fluid. As shown in FIG. 1, the pump main body 1 has a piston 2, a discharge chamber 3, a hydraulic fluid chamber 4 and a water injection port 5.

The piston 2 is provided in the internal space of the pump body 1 so as to be able to reciprocate along its longitudinal direction. For example, the piston 2 has a front portion 2a which is a piston portion on the water discharge side, a rear portion 2b which is a piston portion on the hydraulic oil receiving side, and a tapered portion 2c which is a portion between the front portion 2a and the rear portion 2b. Have. The piston 2 is formed in a bar shape so that the piston diameter of the front portion 2a is smaller than the piston diameter of the rear portion 2b. The tapered portion 2c is formed such that the piston diameter increases or decreases (decreases in FIG. 1) from the front 2a to the rear 2b. The tapered portion 2 c is used for detection of the maximum lift amount L _m (n) of the piston 2 by the detection unit 6 described later.

  The discharge chamber 3 is a space for temporarily storing water discharged from the pump main body 1. As shown in FIG. 1, the discharge chamber 3 is configured to be a space facing the end surface of the front portion 2 a of the piston 2 in the internal space of the pump body 1. The hydraulic oil chamber 4 is a space for receiving the hydraulic oil that operates the pump body 1. As shown in FIG. 1, the hydraulic fluid chamber 4 is configured to be a space facing the end surface of the rear portion 2 b of the piston 2 in the internal space of the pump body 1. The water injection port 5 is for filling the discharge chamber 3 with water, and is provided in the pump body 1 so as to be in communication with the discharge chamber 3. Water to be injected is supplied from the injection port 5 to the discharge chamber 3 through piping or the like of a water tank (not shown). The water is supplied (supplemented) to the discharge chamber 3 through the water injection port 5 every time the water is discharged by the pump body 1.

  Further, as shown in FIG. 1, a water injection pipe 18 communicating with the discharge chamber 3 is connected to the discharge port side of the pump body 1. The water injection pipe 18 is a pipe for guiding the water discharged from the discharge chamber 3 of the pump body 1 to the above-described fuel flow passage. On the other hand, a hydraulic fluid flow passage 17 communicating with the hydraulic fluid chamber 4 is connected to the hydraulic fluid receiving side of the pump body 1.

  The pump body 1 having such a configuration pressurizes and discharges the water to be discharged by moving the piston 2 using the pressure of the hydraulic oil supplied via the control valve 7. At this time, when the control valve 7 is in the on state of supplying the hydraulic fluid to the pump main body 1, the pump body 1 receives the hydraulic fluid from the hydraulic fluid flow passage 17 to the hydraulic fluid chamber 4 via the control valve 7. The pump body 1 moves (advances) the piston 2 to compress the discharge chamber 3 using the pressure of the received hydraulic fluid. Thus, the pump body 1 pressurizes the water in the discharge chamber 3 while blocking the communication between the discharge chamber 3 and the water injection port 5 with the piston 2. The pressurized water is discharged from the discharge chamber 3 into the water injection pipe 18.

  On the other hand, when the control valve 7 is in the OFF state to stop the supply of the hydraulic fluid to the pump main body 1, the hydraulic fluid after the pump main body 1 is used for discharging the water (moving the piston 2) (hereinafter referred to as Drain) is discharged from the hydraulic fluid chamber 4 to the control valve 7 through the hydraulic fluid flow passage 17. At this time, the piston 2 controls the drain in the hydraulic fluid chamber 4 through the hydraulic fluid flow passage 17 by the repulsive force of a biasing portion (not shown) such as a spring provided in the internal space of the pump body 1. Push out to the side. As a result, the piston 2 is returned to the position before the water discharge. The pump body 1 cancels the compression (pressurization of water) of the discharge chamber 3 by the piston 2.

The detector 6 detects the maximum lift amount L _m (n) of the piston 2 in one discharge of water by the pump body 1. As shown in FIG. 1, the detection unit 6 includes a detection processing unit 6 a and an arithmetic processing unit 6 b. The maximum lift amount L _m (n) is an example of the maximum movement amount of the piston 2 moving in the direction (in the upper direction in the present embodiment) that pressurizes the fluid in one discharge of the fluid by the pump body 1.

The detection processing unit 6a performs a detection process for detecting the maximum lift amount L _m (n). Specifically, as shown in FIG. 1, the detection processing unit 6 a is provided in the pump body 1 so as to face the tapered portion 2 c of the piston 2. In the present embodiment, the pair of detection processing units 6a are arranged to face each other with the tapered portion 2c interposed therebetween. The detection processing unit 6a detects (measures) the distance between the piston 2 and the tapered portion 2c that changes due to the movement (lift) of the piston 2. The detection processing unit 6a performs such distance detection processing continuously or intermittently along time series, and in each case, performs arithmetic processing on a signal indicating the obtained distance (hereinafter referred to as a distance detection signal as appropriate). Send to section 6b.

The arithmetic processing unit 6 b performs arithmetic processing for detecting the maximum lift amount L _m (n). In detail, the arithmetic processing unit 6b sequentially receives the distance detection signals from the detection processing unit 6a in chronological order. The arithmetic processing unit 6b selects, from among the plurality of distance detection signals received from the detection processing unit 6a, a distance detection signal with the largest distance and a distance detection signal with the smallest distance. For example, the arithmetic processing unit 6b detects the distance detection signal at which the voltage peaks, when the distance between the detection processing unit 6a and the tapered portion 2c becomes maximum and minimum in one discharge period of water by the pump body 1. It selects as each distance detection signal. Arithmetic processing unit 6b operates based on the distances (distance between detection processing unit 6a and tapered portion 2c) indicated by these selected distance detection signals and the inclination angle of tapered portion 2c to the water of the pump body 1 The maximum lift amount L _m (n) of the piston 2 in one discharge is calculated. In each case, the arithmetic processing unit 6 b transmits a signal indicating the obtained maximum lift amount L _m (n) (hereinafter referred to as a lift amount detection signal as appropriate) to the control unit 11.

  The control valve 7 is a valve that switches between an on state in which hydraulic fluid for operating the pump body 1 is supplied to the pump body 1 and an off state in which supply of hydraulic fluid to the pump body 1 is stopped. For example, the control valve 7 is configured by an on-off type solenoid valve that switches the opening and closing of the hydraulic oil flow passage. In the present embodiment, as shown in FIG. 1, the control valve 7 has a supply flow path unit 7a, a discharge flow path unit 7b, and a drive unit 7c. Further, the control valve 7 includes a hydraulic oil pipe 15 communicating with an accumulator (not shown) that accumulates the pressure of the hydraulic oil, and a drain pipe 16 communicating with a tank (not shown) that collects hydraulic fluid (drain). A hydraulic fluid flow passage 17 communicating with the hydraulic fluid chamber 4 of the pump body 1 is connected. As an example, FIG. 1 shows a state in which the hydraulic fluid pipe 15, the drain pipe 16, and the hydraulic fluid flow channel 17 are connected to the supply flow channel unit 7a of the control valve 7.

  The supply flow path unit 7 a has a supply flow path 8 a for supplying the hydraulic fluid to the pump body 1 and a closed path 8 b for closing the drain pipe 16. The discharge flow path unit 7 b has a discharge flow path 9 a for discharging the drain from the pump body 1 and a closed path 9 b for closing the hydraulic fluid pipe 15. The supply flow path unit 7a and the discharge flow path unit 7b are arranged to be adjacent to each other in a predetermined direction (lateral direction in FIG. 1), for example, as shown in FIG. The drive unit 7c is configured using an electromagnetic coil (solenoid coil) or the like. The drive unit 7c moves the supply flow passage unit 7a and the discharge flow passage unit 7b in the adjacent direction based on the valve control signal from the control unit 11, thereby the supply flow passage unit 7a and the discharge flow passage unit 7b. The hydraulic oil pipe 15, the drain pipe 16, and the hydraulic oil flow passage 17 are connected to either. The control valve 7 selectively switches between the on state and the off state by the action of the drive unit 7c.

  FIG. 2 is a diagram for explaining the on state and the off state of the control valve in the embodiment of the present invention. As shown in FIG. 2, the control valve 7 is switched from the off state to the on state by connecting the supply flow path unit 7 a with the hydraulic fluid pipe 15, the drain pipe 16 and the hydraulic fluid flow path 17. In the ON state, the supply flow path unit 7a connects the supply flow path 8a to the hydraulic fluid pipe 15 and the hydraulic fluid flow path 17 and connects the close path 8b to the drain pipe 16. As a result, the hydraulic fluid pipe 15 and the hydraulic fluid flow passage 17 are in communication via the supply flow channel 8a. The drain pipe 16 is closed by the closing path 8b. The hydraulic fluid is supplied to the hydraulic fluid chamber 4 of the pump main body 1 through the hydraulic fluid pipe 15, the supply flow passage 8a and the hydraulic fluid flow passage 17 which are in such a communication state. The hydraulic fluid supplied to the hydraulic fluid chamber 4 presses the piston 2 of the pump body 1 from the rear 2 b side. The pump body 1 moves the piston 2 using the pressure of the hydraulic fluid, thereby pressurizing the water in the discharge chamber 3 with the front portion 2 a of the piston 2 and discharging it into the water injection pipe 18. The supply of the hydraulic oil is continuously performed while the control valve 7 is in the on state.

  Further, as shown in FIG. 2, the control valve 7 is switched from the on state to the off state by connecting the discharge passage unit 7 b with the hydraulic fluid pipe 15, the drain pipe 16 and the hydraulic fluid flow passage 17. In the OFF state, the discharge flow passage unit 7b connects the discharge flow passage 9a to the drain pipe 16 and the hydraulic fluid flow passage 17 and connects the closed path 9b to the hydraulic fluid pipe 15. As a result, the drain pipe 16 and the hydraulic fluid flow passage 17 communicate with each other through the discharge flow passage 9a. The hydraulic oil pipe 15 is closed by the closing path 9b. As a result, the supply of hydraulic oil in the on state is stopped. In this case, the piston 2 is used for operating oil in the hydraulic oil chamber 4 (i.e., for operating the pump main body 1) by the repulsive force of an urging portion (not shown) such as a spring provided in the internal space of the pump main body 1 The latter hydraulic oil is pressed to the control valve 7 side. The pressed hydraulic fluid is drained from the hydraulic fluid chamber 4 as a drain through the hydraulic fluid flow passage 17, the discharge flow passage 9 a and the drain pipe 16 which are in communication as described above, and a predetermined tank (shown in FIG. ) Are collected inside. As a result, the piston 2 is returned to the position before the water discharge. The pump body 1 releases the compression (pressurization of water) of the discharge chamber 3 by the front portion 2 a of the piston 2 and stops the discharge of water to the water injection pipe 18.

On the other hand, the control unit 11 shown in FIG. 1 controls switching of the control valve 7 between the on state and the off state. Specifically, the control unit 11 is configured of a CPU for executing various programs, a memory, a solenoid drive unit, and the like. The control unit 11 sets a target lift amount L _t (n of the piston 2 of the pump main body 1) according to the water discharge amount required for one discharge of water from the pump main body 1 (the water injection amount into the fuel flow passage). Derive). The target lift amount L _t (n) is an example of a movement amount (target movement amount) of the piston 2 which is a target for the pump body 1 to discharge the required discharge amount in one discharge. For example, since the target lift amount L _t (n) has known equipment specifications such as the discharge capacity of the pump main body 1 for discharging the fluid, the target lift amount L _t (n) is required for one discharge of the fluid by the pump main body 1 It can be derived based on the discharge amount of the fluid.

The control unit 11 controls the target lift amount L _t (n) derived at the current discharge of water from the pump body 1 and the maximum lift amount L _m (n-1) detected by the detection unit 6 at the previous discharge. The time correction value of the valve on time of the control valve 7 is calculated based on the difference between The valve on time is the time to bring the control valve 7 into the on state described above. The time correction value is a value (correction time) for correcting the valve on time. The control unit 11 corrects the valve on time at the time of the current discharge of water from the pump main body 1 in consideration of the calculated time correction value so that the valve on time after correction is continuously turned on. Control valve 7 is controlled.

In the present embodiment, the control unit 11 has a data table 11a as shown in FIG. The data table 11 a indicates the correlation between the target lift amount L _t (n) of the piston 2 and the valve on basic time of the control valve 7. The valve on basic time is a valve on time of the control valve 7 (the theoretical valve on time on equipment specifications) set according to the target lift amount L _t (n) of the piston 2. The data table 11a includes a plurality of combinations of the target lift amount L _t (n) of the piston 2 and the valve on basic time of the control valve 7 which are correlated with each other. The control unit 11 derives a valve-on basic time correlated with the target lift amount L _t (n) derived at the current discharge of water by the pump main body 1 based on the data table 11 a. The control unit 11 corrects the valve on time at the time of the current discharge of water by the pump main body 1 so as to approach the time obtained by adding the derived valve on basic time and the above time correction value.

(Control method of marine fluid pump)
FIG. 3 is a flow chart showing an example of a control method of the marine fluid pump according to the embodiment of the present invention. FIG. 4 is a view specifically explaining a control method of the marine fluid pump according to the embodiment of the present invention. In the control method of the marine fluid pump 10 (see FIG. 1), each process of steps S101 to S104 shown in FIG. 3 is performed. At this time, as shown in FIG. 4, the switching between the on state and the off state of the control valve 7 is controlled based on the valve control signal S1 from the control unit 11, and the pump body 1 discharges water through this control. The lift amount of the piston 2 is controlled. Hereinafter, the current discharge of water by the pump main body 1 is referred to as “water discharge of the nth cycle”, and the previous discharge of water by the pump main body 1 is referred to as “water discharge of the n−1th cycle”. The next water discharge is referred to as "n + 1th cycle water discharge". The control method of the marine fluid pump 10 exemplifies each process of steps S101 to S104 when the water discharge of the nth cycle is performed.

As shown in FIG. 4, in the water discharge in the n-1th cycle, the control valve 7 switches from the off state to the on state at the timing of time T1 based on the valve control signal S1, and thereafter, the timing of time T2. Switches from the on state to the off state. The time from time T1 to time T2 is the valve on time ΔT3 of the control valve 7 in the water discharge in the n−1th cycle. The valve on time ΔT3 is, as shown in FIG. 4, a valve on basic time of the control valve 7 set according to the target lift amount L _t (n−1) of the piston 2 in the water discharge in the n−1 th cycle. It corresponds to the time which added (DELTA) T1 and the time correction value (DELTA) T2 calculated by the control part 11 at the time of the water discharge of the n-1st cycle.

Hydraulic oil is continuously supplied to the hydraulic fluid chamber 4 of the pump body 1 via the control valve 7 in the on state during the valve on time ΔT3. The pump body 1 moves the piston 2 using the pressure of the supplied hydraulic fluid, thereby pressurizing and discharging water. As shown in FIG. 4, the lift amount of the piston 2 increases with the passage of time from the timing of time T1 when the control valve 7 is turned on, and the time from the timing of time T2 when the control valve 7 is turned off It decreases with the passage of time. In this case, the maximum lift of the piston 2 in the n-1 th cycle water discharge L _{m (n-1),} as shown in FIG. 4, the lift of the piston 2 at the timing of time T2. Detector 6 transmits a lift detection signal indicating the maximum lift L _{m (n-1)} detecting a maximum resultant lift L _{m (n-1)} to the control unit 11. The control unit 11 receives the lift amount detection signal from the detection unit 6 and holds the maximum lift amount L _m (n-1) indicated by the received lift amount detection signal as a parameter at the time of water discharge in the subsequent n cycle Do.

  Next, in the water discharge of the nth cycle, as shown in FIG. 3, the control unit 11 sets the target of the piston 2 according to the discharge amount of the fluid required for one discharge of the fluid by the pump body 1. The movement amount is derived (step S101).

In the present embodiment, in step S101, the control unit 11 derives the target lift amount L _t (n) of the piston 2 in accordance with the water discharge amount required for the nth cycle water discharge.

  Next, based on the difference between the target moving amount of the piston 2 and the maximum moving amount of the piston 2 at the previous discharge of the fluid in step S101 (target moving amount deriving step), the control unit 11 A time correction value of valve on time is calculated (step S102).

In the present embodiment, in step S102, the control unit 11 acquires and holds the target lift amount L _t (n) of the piston 2 derived in step S101 described above and the water discharge of the n-1 cycle. The difference (= L _t (n) −L _m (n−1)) with the maximum lift amount L _m (n−1) of the piston 2, that is, the lift amount deviation ΔL (n) shown in FIG. 4 is calculated. The control unit 11 calculates the time correction value ΔT12 in the water discharge of the nth cycle based on the calculated lift amount deviation ΔL (n). At this time, the control unit 11 is a lift based on the equipment specification of the pump main body 1, for example, the lift amount per unit time of the piston 2 moving using the pressure of the hydraulic oil (time-dependent change amount of lift amount) The amount deviation ΔL (n) is converted to time (that is, converted to time correction value ΔT12). The control unit 11 updates the time correction value ΔT2 in the n-1 th cycle water discharge to the time correction value ΔT12 calculated in this manner.

  Next, the control unit 11 corrects the valve on time of the control valve 7 at the time of the current discharge of the fluid by the pump main body 1 in consideration of the time correction value ΔT12 at step S102 (time correction value calculation step) (step S103).

  In the present embodiment, in step S103, the control unit 11 derives the valve on basic time ΔT11 of the control valve 7 set in accordance with the target lift amount Lt (n) of the piston 2. For example, based on the data table 11a, the control unit 11 derives a valve on basic time ΔT11 that correlates with the target lift amount Lt (n) in step S101 described above. The control unit 11 adds the valve on basic time ΔT11 of the control valve 7 at the nth cycle of water discharge to the valve on basic time ΔT11 derived as described above and the time correction value ΔT12 calculated in step S102 (= Calculation (correction) is performed to be ΔT11 + ΔT12).

  Next, the control unit 11 controls the control valve 7 so as to be continuously in the on state during the period of the valve on time ΔT13 after the correction in step S103 (correction step) (step S104). After executing step S104 (correction step), the control unit 11 returns to step S101 described above, and repeats the processing steps after step S101.

  In the present embodiment, in step S104, the control unit 11 transmits to the control valve 7 the valve control signal S1 (see FIG. 4) instructing the valve on time ΔT13 corrected as described above to be continuously on. Do. Thus, the control unit 11 controls switching between the on state and the off state of the control valve 7 in the water discharge at the nth cycle. As shown in FIG. 4, the control valve 7 switches from the off state to the on state at time T3 based on the valve control signal S1, and then switches from the on state to the off state at time T4. . The time from time T3 to time T4 is the valve on time ΔT13 of the control valve 7 in the nth cycle of water discharge.

During the valve on time ΔT13, the hydraulic fluid is continuously supplied to the hydraulic fluid chamber 4 of the pump body 1 via the control valve 7 in the on state. The pump body 1 moves the piston 2 using the pressure of the supplied hydraulic fluid, thereby pressurizing and discharging water. As shown in FIG. 4, the lift amount of the piston 2 increases with the passage of time from the timing of time T3 when the control valve 7 is turned on, and the time from the timing of time T4 when the control valve 7 is turned off It decreases with the passage of time. In this case, the maximum lift amount L _m (n) of the piston 2 in the water discharge at the nth cycle is the lift amount of the piston 2 at the timing of time T4, as shown in FIG. Detector 6 transmits a lift detection signal indicating the maximum detected the lift amount L _{m (n),} the amount of the maximum resultant lift L _{m (n)} to the controller 11. The control unit 11 receives the lift amount detection signal from the detection unit 6, and holds the maximum lift amount L _m (n) indicated by the received lift amount detection signal as a parameter at the time of water discharge of the subsequent n + 1 cycle.

After that, in the n + 1th cycle water discharge, the difference between the target lift amount L _t (n + 1) of the piston 2 in the n + 1 cycle water discharge and the maximum lift amount L _m (n) of the piston 2 in the n cycle water discharge _{= L t (n + 1)} -L m is (n)) lift deviation ΔL (n + 1) using the respective process steps of step S101~S104 to shown in FIG. 3 is performed. Thus, switching of the control valve 7 between the on state and the off state in the n + 1th cycle water discharge is controlled, and the lift amount of the piston 2 in the n + 1th cycle water discharge is controlled through this control. For example, as shown in FIG. 4, in the water discharge of the n + 1th cycle, the control valve 7 switches from the off state to the on state at the timing of time T5 based on the valve control signal S1, and then the timing of the time T6. Switches from the on state to the off state. The time from time T5 to time T6 is the valve on time ΔT23 of the control valve 7 in the water discharge of the (n + 1) th cycle. The valve on time ΔT23 is, as shown in FIG. 4, the valve on basic time ΔT21 of the control valve 7 set according to the target lift amount L _t (n + 1) of the piston 2 in the n + 1th cycle water discharge, and n + 1 This corresponds to the time obtained by adding the time correction value ΔT22 calculated by the control unit 11 at the time of water discharge in the cycle.

  During the valve on time ΔT23, the hydraulic fluid is continuously supplied to the hydraulic fluid chamber 4 of the pump body 1 via the control valve 7 in the on state. The pump body 1 moves the piston 2 using the pressure of the supplied hydraulic fluid, thereby pressurizing and discharging water. As shown in FIG. 4, the lift amount of the piston 2 increases with the passage of time from the timing of time T5 when the control valve 7 is turned on, and the time from the timing of time T6 when the control valve 7 is turned off It decreases with the passage of time. In this case, as shown in FIG. 4, the maximum lift amount of the piston 2 in the water discharge of the n + 1th cycle is the lift amount of the piston 2 at the timing of time T6. The detection unit 6 detects the maximum lift amount, and transmits a lift amount detection signal indicating the obtained maximum lift amount to the control unit 11. The control unit 11 holds the maximum lift amount as a parameter at the time of water discharge in the subsequent cycle, as in the case of each water discharge in the n-1th cycle and the nth cycle described above.

By the control method of the marine fluid pump 10 as described above, the error between the target lift amount L _t (n) of the piston 2 and the maximum lift amount L _m (n) in the nth cycle water discharge is the n−1 th cycle It is reduced compared to water discharge. Similarly, the error between the target lift amount L _t (n + 1) of the piston 2 and the maximum lift amount in the n + 1th cycle water discharge is reduced as compared to the nth cycle water discharge.

  As described above, in the marine fluid pump 10 and the control method thereof according to the embodiment of the present invention, the control valve 7 for supplying the hydraulic oil for operating the pump main body 1 is supplied with the hydraulic oil in an on state The piston of the pump body 1 is selected as an open / close control valve that selectively switches between the pump and the off state for stopping the supply of hydraulic fluid, and according to the fluid discharge amount required for one discharge of fluid from the pump body 1 The target movement amount of 2 is derived, and the control valve 7 is turned on based on the difference between the target movement amount of the piston 2 at the time of fluid discharge this time and the maximum movement amount of the piston 2 at the fluid discharge last time Calculate the time correction value of the valve on time to be taken into account, add the calculated time correction value, correct the valve on time of the control valve 7 at the time of fluid discharge this time, and continue the corrected valve on time. Control valve to turn on By moving the piston 2 using the pressure of the hydraulic fluid supplied to the pump body 1 via the control valve 7, the piston 2 pressurizes the fluid and discharges it from the pump body 1. It is like that.

  With the above configuration, the complicated calculation process and valve such as adjusting the opening degree of the control valve by sequentially calculating the deviation between the actual measurement value of the movement amount of the piston 2 and the target value during the discharge period of the fluid by the pump body 1 Even if the opening degree control is not performed, the valve on time of the control valve 7 can be accurately corrected with a simple device configuration. Therefore, the amount of movement of the piston 2 at the time of pressurizing and discharging the fluid can be accurately controlled while suppressing an increase in the cost of the apparatus configuration. As a result, it is possible to secure the accuracy of the discharge amount of the fluid required for the marine fluid pump 10 (for example, the fuel injection amount and the water injection amount in the marine diesel engine).

  In addition, since the control valve 7 described above is not the electromagnetic valve of opening degree adjustment type that is relatively weak to the mixture of foreign matter but the electromagnetic valve of open / close type that is relatively strong to the mixture of foreign matter, the marine diesel engine operates The control valve 7 suitable for the marine fluid pump 10 installed in an environment, that is, an environment in which foreign matter is likely to be mixed can be configured. As a result, it is possible to suppress a failure or maintenance frequency caused by foreign matter mixing into the control valve 7 of the marine fluid pump 10 in the ship.

  In the embodiment described above, the water injection pump is illustrated as the marine fluid pump 10, but the present invention is not limited to this. For example, the marine fluid pump 10 may be a fuel injection pump that discharges (pumps) fuel to a fuel injection valve, or may be a pump that discharges fluid other than fuel. That is, in the present invention, the type of fluid to be discharged is not particularly limited.

  In the above-described embodiment, the control unit 11 is exemplified in which the data table 11a indicating the correlation between the target movement amount of the piston 2 and the valve-on basic time of the control valve 7 is preset. It is not limited. For example, an arithmetic expression, an arithmetic program, or the like for calculating the valve-on basic time of the control valve 7 based on the target movement amount of the piston 2 may be set in the control unit 11 in advance.

  Moreover, in the embodiment described above, the lift amount (the upward movement amount of the piston 2) is illustrated as the movement amount of the piston 2, but the present invention is not limited to this. In the present invention, the amount of movement of the piston 2 may be any amount of movement in the direction to pressurize the fluid to be discharged, and this direction is not particularly limited.

  Further, the present invention is not limited by the above-described embodiment, and the present invention also includes those configured by appropriately combining the above-described respective constituent elements. In addition, other embodiments, examples, operation techniques and the like made by those skilled in the art based on the above-described embodiments are all included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 pump main body 2 piston 2a front part 2b rear part 2c taper part 3 discharge chamber 4 hydraulic fluid chamber 5 injection port 6 detection part 6a detection processing part 6b arithmetic processing part 7 control valve 7a supply flow path unit 7b discharge flow path unit 7c drive part 8a supply flow path 8b closed path 9a discharge flow path 9b closed path 10 marine fluid pump 11 control section 11a data table 15 hydraulic oil pipe 16 drain pipe 17 hydraulic oil flow path 18 water injection pipe S1 valve control signal

Claims (6)

A pump body that pressurizes and discharges fluid by moving a piston using pressure of hydraulic oil;
A detection unit that detects a maximum moving amount of the piston in one discharge of the fluid;
A control valve that selectively switches between an on state for supplying the hydraulic fluid to the pump body and an off state for stopping the supply of the hydraulic fluid;
The target movement amount of the piston is derived according to the discharge amount of the fluid required for one discharge of the fluid, and the target movement amount derived during the current discharge of the fluid and the previous discharge Based on the difference from the detected maximum movement amount, a time correction value of valve on time, which is a time to bring the control valve into the on state, is calculated, and the calculated time correction value is added. A control unit that corrects the valve on time at the time of the current discharge of the fluid and controls the control valve so that the valve on time after correction is continuously maintained in the on state;
A marine fluid pump comprising:   The control unit derives a valve on basic time which is a valve on time of the control valve set according to the target movement amount of the piston, and the valve on time at the time of the current discharge of the fluid is the The marine fluid pump according to claim 1, wherein the marine fluid pump according to claim 1 is corrected so as to be the time obtained by adding the valve on basic time and the time correction value.   The control unit has a data table indicating the correlation between the target movement amount of the piston and the valve-on basic time of the control valve, and is correlated with the target movement amount derived during the current discharge of the fluid. The marine fluid pump according to claim 2, wherein the valve on basic time to be derived is derived based on the data table. The hydraulic fluid is supplied to the pump body via a control valve that alternatively switches between an on state for supplying the hydraulic fluid to the pump body and an off state for stopping the supply of the hydraulic fluid, and In a control method of a marine fluid pump which pressurizes and discharges fluid by moving a piston of the pump body using pressure.
A target movement amount deriving step of deriving a target movement amount of the piston according to the discharge amount of the fluid required in one discharge of the fluid;
A valve which is a time during which the control valve is turned on based on a difference between the target movement amount of the piston in the target movement amount deriving step and the maximum movement amount of the piston at the previous discharge of the fluid. A time correction value calculating step of calculating a time correction value of the on time;
A correction step of correcting the valve on time at the time of the current discharge of the fluid in consideration of the time correction value obtained by the time correction value calculating step;
A control step of controlling the control valve so that the valve on time after correction continues to be in the on state;
A control method of a marine fluid pump comprising:   The correction step derives a valve on basic time which is a valve on time of the control valve set according to the target movement amount of the piston, and the valve on time at the time of the current discharge of the fluid is the The control method of the marine fluid pump according to claim 4, wherein the correction time is a time obtained by adding the valve on basic time and the time correction value.   In the correction step, the valve on is correlated with the target moving amount by the target moving amount deriving step on the basis of a data table indicating the correlation between the target moving amount of the piston and the valve on basic time of the control valve. The control method of the marine fluid pump according to claim 5, wherein the basic time is derived.

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