Reciprocating pump and flow condition monitoring method

Abstract

To monitor the flow of handled liquid in a reciprocating pump without using a detection device that comes into contact with the liquid. [Solution] A reciprocating pump 1 according to the present invention includes a diaphragm 6, a pump chamber 21a, a plunger 5, an electromagnetic actuator 41, an actuator control unit 311, an acquisition unit 312 for acquiring, as a specific current value, a control current value of the electromagnetic actuator when at least the plunger is located at a specific position, a storage unit 35 for storing, as a reference current value, a normal control current value when at least the plunger is located at the specific position, as a reference current value, among normal control current values ​​which are control current values ​​in a normal state, and a determination unit 313 for determining whether a suction state and / or a discharge state is normal or abnormal based on the specific current value and the reference current value. The specific position is a position corresponding to a point at which, when there is an abnormality, a characteristic change corresponding to the abnormality appears in the current value waveform of the control current value for one stroke of the plunger.

Description

[Technical field]

[0001] The present invention relates to a reciprocating pump and a method for monitoring flow conditions. [Background technology]

[0002] A reciprocating pump includes a diaphragm, a plunger that reciprocates the diaphragm, and a pump chamber that houses the diaphragm. The reciprocating pump reciprocates the diaphragm by the reciprocating motion of the plunger, and delivers a constant amount of the pumped liquid by alternately suctioning and discharging the pumped liquid in the pump chamber. Among reciprocating pumps, there are known reciprocating pumps that include detection devices (e.g., pressure gauges, flow meters, flow sensors, etc.) that come into contact with the pumped liquid and monitor the suction and discharge states (hereinafter referred to as "flow states") of the pumped liquid (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-21503 A [Patent Document 2] JP 2019-173634 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the reciprocating pump disclosed in Patent Document 1, a mounting hole communicating with the pump chamber is arranged in a housing that defines the pump chamber, and a pressure gauge is attached to the mounting hole. In this configuration, processing of the mounting hole and a seal member between the mounting hole and the pressure gauge are required. In the reciprocating pump disclosed in Patent Document 2, a pressure sensor is attached to the discharge pipe. In this configuration, a discharge pipe design for mounting the pressure sensor, its construction, and wiring construction for the pressure sensor are required. In addition, when the operation of the reciprocating pump is stopped in conjunction with the detection of an abnormality, wiring is required to transmit the detection signal of the pressure gauge to the control system of the reciprocating pump. In this way, the manufacturing cost of these reciprocating pumps increases by the amount required for the processing cost, material cost, and construction cost.

[0005] In addition, when the handled liquid is corrosive, there is little freedom in selecting the detection device, and dedicated detection devices tend to be expensive. Furthermore, flow meters and flow sensors may malfunction if air bubbles get mixed in the piping. Thus, there are technical challenges in monitoring the flow state using detection devices that come into contact with the handled liquid.

[0006] An object of the present invention is to monitor the flow state of a pumped liquid in a reciprocating pump without using a detection device that comes into contact with the liquid. [Means for solving the problem]

[0007] A reciprocating pump in one embodiment of the present invention is a reciprocating pump that sucks in and discharges pumped fluid by reciprocating a diaphragm, the reciprocating pump including the diaphragm, a pump chamber in which the diaphragm is housed, a plunger that reciprocates the diaphragm, an electromagnetic actuator that reciprocates the plunger, an actuator control unit that performs closed-loop control of the operation of the electromagnetic actuator, and a control current value used to control the operation of the electromagnetic actuator, the control current value being obtained as a specific current value when at least the plunger is located at a specific position within one stroke of the plunger. Then, angle information corresponding to the control current value is acquired in association with the control current value.and a normal control current value, which is the control current value when the suction state and the discharge state of the pumped liquid are normal, is set as a reference current value when at least the plunger is located at the specific position. , in association with the angle information corresponding to the reference current value a storage unit that stores the specific current value and the reference current value, and a determination unit that determines whether the suction state and / or the discharge state is normal or abnormal based on the specific current value and the reference current value; a reference acquisition unit that acquires the normal control current value, a setting unit that sets the reference current value based on the normal control current value acquired by the reference acquisition unit, and a change detection unit that detects a change in an operating condition of the reciprocating pump. and the angle information is information indicating a position of the plunger within one stroke of the plunger, the specific position is a position corresponding to a point at which a characteristic change corresponding to the abnormality appears in a current value waveform of the control current value for one stroke of the plunger when the abnormality exists, When the change detection unit detects a change in the operating condition, the reference acquisition unit acquires the normal control current value in association with the angle information corresponding to the normal control current value, and the storage unit updates and stores the reference current value based on the acquired normal control current value and the angle information associated with the normal control current value. .

[0008] A reciprocating pump in one embodiment of the present invention is a reciprocating pump that sucks in and discharges pumped fluid by reciprocating a diaphragm, and includes the diaphragm, a pump chamber in which the diaphragm is housed, a plunger that reciprocates the diaphragm, an electromagnetic actuator that reciprocates the plunger, an actuator control unit that performs closed-loop control of the operation of the electromagnetic actuator, a current value acquisition unit that acquires, as a specific current value, at least the control current value when the plunger is located at a specific position within one stroke of the plunger, among control current values ​​used to control the operation of the electromagnetic actuator, and a current value acquisition unit that acquires a moving speed of the plunger. the specific current value, the moving speed, and the stroke number, into the learning model, and an estimation unit inputs the specific current value, the moving speed, and the stroke number into the learning model to estimate whether the suction state or the discharge state is normal or abnormal, wherein the specific position corresponds to a point at which a characteristic change corresponding to the abnormality appears in the current value waveform of the control current value for one stroke of the plunger when the abnormality exists.

[0009] A reciprocating pump in one embodiment of the present invention is a reciprocating pump that sucks in and discharges pumped fluid by reciprocating a diaphragm, the reciprocating pump including: the diaphragm; a pump chamber in which the diaphragm is accommodated; a plunger that reciprocates the diaphragm; an electromagnetic actuator that reciprocates the plunger; an actuator control unit that performs closed-loop control of the operation of the electromagnetic actuator; a current value acquisition unit that acquires, as a specific current value, at least the control current value when the plunger is located at a specific position within one stroke of the plunger, among control current values ​​used to control the operation of the electromagnetic actuator; and a calculation unit that calculates an amount of change between the specific current value that is a reference and the latest specific current value, among a plurality of the specific current values ​​acquired at a predetermined sampling interval. a current acquisition unit that acquires the moving speed of the plunger; a stroke number acquisition unit that acquires the number of strokes of the plunger; a memory unit that stores a trained learning model that has been machine-learned to output whether or not an abnormality will occur in the suction state or discharge state of the handled fluid after a predetermined future period has elapsed when the specific current value, the amount of change, the moving speed, and the stroke number are input; and a prediction unit that inputs the specific current value, the amount of change, the moving speed, and the stroke number into the learning model and predicts whether or not the abnormality will occur in the suction state or the discharge state within the period, wherein the specific position is a position corresponding to a point at which a characteristic change corresponding to the abnormality appears in the current value waveform of the control current value for one stroke of the plunger when the abnormality occurs.

[0010] A flow state monitoring method according to one embodiment of the present invention includes a diaphragm, a pump chamber in which the diaphragm is accommodated, a plunger for reciprocating the diaphragm, an electromagnetic actuator for reciprocating the plunger, an actuator control unit for performing closed-loop control of the operation of the electromagnetic actuator, and a reference current value among control current values ​​used to control the operation of the electromagnetic actuator. , in association with angle information corresponding to the reference current valueand a memory unit for storing a reference current value and a reference current value indicating whether a suction state and / or a discharge state of the pumped liquid is normal or abnormal, the reference current value being, among normal control current values ​​which are the control current values ​​when the suction state and the discharge state are normal, the normal control current value when at least the plunger is located at a specific position within one stroke of the plunger, and the specific position being a position corresponding to a point at which a characteristic change corresponding to the abnormality appears in a current value waveform of the control current value for one stroke of the plunger when the abnormality exists, the angle information is information indicating a position of the plunger within one stroke of the plunger, The flow condition monitoring method includes: a step of the reciprocating pump detecting a change in operating conditions of the reciprocating pump; a step of the reciprocating pump acquiring the normal control current value in association with the angle information corresponding to the normal control current value when the reciprocating pump detects the change in operating conditions; and a step of the reciprocating pump setting the reference current value based on the acquired normal control current value and the angle information stored in the memory unit in association with the normal control current value. The method includes a step in which the reciprocating pump acquires, as a specific current value, at least the control current value when the plunger is located at the specific position, from among the control current values, and a step in which the reciprocating pump determines whether the suction state and / or the discharge state is normal or abnormal based on the specific current value and the reference current value. Effect of the Invention

[0011] According to the present invention, the flow state of the pumped liquid can be monitored without using a detection device that comes into contact with the liquid in the reciprocating pump. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view showing an embodiment of a reciprocating pump according to the present invention. [Diagram 2] FIG. 2 is a functional block diagram of the reciprocating pump of FIG. [Diagram 3] FIG. 1A is a schematic diagram showing an example of a current value waveform under normal conditions, FIG. 1B is a schematic diagram showing an example of a current value waveform under abnormal conditions, and FIG. 1C is a schematic diagram showing an example of a change in the current value waveform. [Figure 4] 2 is a schematic diagram showing an example of information stored in a storage unit included in the reciprocating pump of FIG. 1; FIG. [Diagram 5]2A to 2C are schematic diagrams illustrating the operation modes of the reciprocating pump of FIG. 1, where (a) shows the standard mode, (b) shows the high viscosity mode, and (c) shows the low pulsation mode. [Figure 6] 2 is a flowchart showing an example of the operation of the reciprocating pump of FIG. 1. [Figure 7] 2 is a schematic diagram showing an example of a normal control current value of a motor device included in the reciprocating pump of FIG. 1. [Figure 8] FIG. 13 is a schematic diagram showing an example of a control current value in an abnormal state. [Figure 9] FIG. 4 is a functional block diagram showing a second embodiment of a reciprocating pump according to the present invention. [Figure 10] 10 is a schematic diagram showing an example of information stored in a storage unit included in the reciprocating pump of FIG. 9. [Figure 11] 10 is a flowchart showing an example of the operation of the reciprocating pump of FIG. 9. [Figure 12] FIG. 4 is a functional block diagram showing a third embodiment of a reciprocating pump according to the present invention. [Figure 13] 13 is a schematic diagram showing an example of information stored in a storage unit included in the reciprocating pump of FIG. 12. FIG. [Figure 14] 13 is a flowchart showing an example of the operation of the reciprocating pump of FIG. 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An embodiment of a reciprocating pump (hereinafter referred to as "the pump") and a flow condition monitoring method (hereinafter referred to as "the method") according to the present invention will be described below. In the following description, the drawings will be referred to as appropriate. In the drawings, the same members and elements are given the same reference numerals, and duplicated descriptions will be omitted. Furthermore, the dimensional ratios of the elements may be exaggerated for the sake of convenience of explanation, and are not limited to the ratios shown in the drawings.

[0014] ●Reciprocating pump(1)● ●Configuration of reciprocating pump (1) FIG. 1 is a schematic cross-sectional view showing an embodiment of the present pump. FIG. 2 is a functional block diagram of the pump.

[0015] This pump 1 is an electromagnetically driven diaphragm pump that sucks in and discharges the pumped liquid. This pump 1 includes a housing 2, a control device 3, a drive unit 4, a plunger 5, a diaphragm 6, an operation unit 7, a connection unit 8, a suction pipe L1, a discharge pipe L2, a suction valve V1, and a discharge valve V2. The basic configuration of this pump 1 is the same as that of a known reciprocating pump. Therefore, in the following description, a description of the basic configuration of this pump 1 will be omitted.

[0016] The housing 2 accommodates a control device 3, a drive unit 4, a plunger 5, and a diaphragm 6. The housing 2 includes a pump head portion 21 and a main body portion 22.

[0017] The pump head 21 houses the diaphragm 6 and sucks pumped liquid from the suction pipe L1 and discharges the pumped liquid to the discharge pipe L2. The pump head 21 includes a pump chamber 21a, a suction flow path 21b, and a discharge flow path 21c. The pump chamber 21a houses the diaphragm 6. The suction flow path 21b is a flow path that communicates with the pump chamber 21a and the suction pipe L1. The discharge flow path 21c is a flow path that communicates with the pump chamber 21a and the discharge pipe L2.

[0018] The main body 22 houses the control device 3, the drive unit 4, and the plunger 5. The main body 22 includes an electric chamber 22a and a machine chamber 22b. The electric chamber 22a houses the control device 3. The electric chamber 22a is disposed above the machine chamber 22b. The machine chamber 22b houses the drive unit 4 and the plunger 5. In the following description, the direction in which the pump chamber 21a is disposed relative to the machine chamber 22b is the "forward direction," and the opposite direction is the "rearward direction." That is, the pump chamber 21a is disposed in front of the machine chamber 22b.

[0019] The control device 3 controls the overall operation of the pump 1. The control device 3 includes, for example, a processor such as a CPU (Central Processing Unit) 31, a volatile memory such as a RAM (Random Access Memory) 32 that functions as a working area for the CPU 31, a non-volatile memory such as a ROM (Read Only Memory) 33 that stores various information such as a state determination program, a driver circuit 34 for a motor device 41 described below, and a storage unit 35. The CPU 31 functions as an actuator control unit 311, an acquisition unit 312, a determination unit 313, a setting unit 314, a change detection unit 315, and a specific operation control unit 316. That is, the control device 3 also includes the actuator control unit 311, the acquisition unit 312, the determination unit 313, the setting unit 314, the change detection unit 315, and the specific operation control unit 316.

[0020] A state determination program runs in the control device 3, and the state determination program cooperates with the hardware resources of the pump 1 to realize the method described below. By causing a processor (CPU 31) included in the control device 3 to execute the state determination program, the state determination program can cause the processor to function as an actuator control unit 311, an acquisition unit 312, a determination unit 313, a setting unit 314, a change detection unit 315, and a specific operation control unit 316, and can cause the processor to execute the method. Furthermore, by causing a computer to execute the state determination program, the state determination program can cause the computer to function as the control device 3.

[0021] In the present invention, the state determination program may be stored in the storage unit 35. The state determination program may also be stored in a non-transitory storage medium (e.g., a CD (Compact Disc), a DVD (Digital Versatile Disc), a USB (Universal Serial Bus) memory, etc.) in an installable file format or an executable file format, and provided to the pump 1 via a dedicated read-out medium.

[0022] The actuator control section 311 controls the operation of the motor device 41 via the driver circuit 34. The specific operation of the actuator control section 311 will be described later.

[0023] The acquiring unit 312 acquires information (e.g., a control current value, etc.) necessary for executing the present method. A specific operation of the acquiring unit 312 will be described later. The acquiring unit 312 also functions as a reference acquiring unit in the present invention. That is, the acquiring unit 312 is an example of a reference acquiring unit in the present invention.

[0024] The "control current value" is the current value of a current (hereinafter referred to as the "control current") used to control the operation of the motor 411 described below. The control current value is supplied from the driver circuit 34 to the motor 411 under the control of the actuator control section 311. In the present invention, the control current value includes a normal control current value and a specific current value.

[0025] The "normal control current value" is the control current value when the suction and discharge states of the handled liquid in this pump 1, i.e., the flow state of the handled liquid in this pump 1 (collectively referred to as the "flow state"), is normal (hereinafter simply referred to as "normal").

[0026] The "specific current value" is, among the control current values, a control current value at least when the plunger 5 is located at a specific position within one stroke of the plunger 5. In other words, the specific current value includes the control current value supplied to the motor 411 when the plunger 5 is located at the specific position. In this embodiment, the specific current value is the control current value supplied to the motor 411 when the plunger 5 is located at the specific position.

[0027] The "specific position" is a position of the plunger 5 within one stroke of the plunger 5 at which, when there is an abnormality in the flow state in this pump 1 (hereinafter simply referred to as "abnormality"), a characteristic change corresponding to the abnormality appears in the current value waveform of the control current value for one stroke of the plunger 5. The specific position will be described in detail later.

[0028] The "abnormal flow state" is, for example, an abnormality due to cavitation occurring in the pump chamber 21a during the suction stroke, a gas lock occurring in the pump chamber 21a during the discharge stroke, leakage of the pumped liquid, wear and tear of the diaphragm 6, etc. For example, if cavitation occurs in the pumped liquid in the pump chamber 21a due to negative pressure during the suction stroke, normal suction of the pumped liquid is hindered, resulting in an abnormal suction state. Also, for example, if a gas lock occurs due to air in the pump chamber 21a, normal discharge of the pumped liquid is hindered, resulting in an abnormal discharge state. When such an abnormality occurs, a larger or smaller torque is required for the reciprocating motion of the plunger 5, and the control current value increases or decreases.

[0029] The determining unit 313 determines whether the suction state and / or the discharge state (flow state) is normal or abnormal based on the specific current value and the reference current value. A specific operation of the determining unit 313 will be described later.

[0030] The "reference current value" is a current value that serves as a reference for judgment by the judgment unit 313. The reference current value is, among the normal control current values, at least the normal control current value when the plunger 5 is located at a specific position. In other words, the reference current value includes the normal control current value that was supplied to the motor 411 when the plunger 5 was located at a specific position. In this embodiment, the reference current value is, among the normal control current values, the normal control current value that was supplied to the motor 411 when the plunger 5 was located at a specific position.

[0031] FIG. 3(a) is a schematic diagram showing an example of a current value waveform under normal conditions, (b) is a schematic diagram showing an example of a current value waveform under abnormal conditions, and (c) is a schematic diagram showing an example of a change in the current value waveform. The figure shows only the outer shell of the current value waveform. The vertical axis of the figure shows the control current value. The horizontal axis of the figure shows the position of the plunger 5 in one stroke of the plunger 5 in angle. Here, in the figure, one stroke of the plunger 5 is shown as one cycle of "360°", the angle when the plunger 5 is located at the top dead center is shown as "0° / 360°", and the angle when the plunger 5 is located at the bottom dead center is shown as "180°". In FIG. 3(c), the current value waveform in a normal state is superimposed on the current value waveform in an abnormal state, and the area where there is a difference between the two (difference area: area indicated by the dashed arrow) is displayed in a dark color, and the boundary of the difference area in the stroke is shown by a dashed line.

[0032] As shown in FIG. 3(a), in the discharge process, a high torque is required to push out the pumped liquid sucked into the pump chamber 21a. Therefore, in the discharge process, the control current value is significantly increased. On the other hand, in the suction process, a high torque like that in the discharge process is not required, and the control current value is stably small. As shown in FIG. 3(b), when an abnormality occurs in the suction state or discharge state of the pumped liquid, the control current value increases or decreases in response to the abnormality, and the current value waveform is deformed from the normal state. This increase or decrease in the control current value (deformation of the current value waveform) is a unique increase or decrease (deformation) corresponding to the abnormality. As a result, as shown by the shading in FIG. 3(c), a characteristic change (increase or decrease, deformation) corresponding to the abnormality appears in the difference region between the normal current value waveform and the abnormal current value waveform. In this embodiment, the control device 3 (determination unit 313) detects an abnormality in the flow state based on a difference value between the normal control current value (reference current value) and the abnormal control current value (specific current value) at a specific position, among the changes in the current value waveform of the control current value. Here, the specific position is set, for example, to the position in the differential region where the difference value is the largest, or a position in the vicinity of that position (for example, the positions indicated by "θ1" and "θ2" in FIG. 3(c)).

[0033] In the following description, primary reference will be made to FIGS. 1 and 2. The setting unit 314 sets the reference current value based on the normal control current value. The specific operation of the setting unit 314 will be described later.

[0034] The change detection unit 315 detects a change in the operating conditions (such as an operating mode, forward speed, return speed, and number of strokes, which will be described later) of the pump 1. The specific operation of the change detection unit 315 will be described later.

[0035] When the determination unit 313 determines that "there is an abnormality in the flow state," the specific operation control unit 316 executes control necessary for a specific operation to eliminate the abnormality. The specific operation of the specific operation control unit 316 will be described later.

[0036] The "specific operation" is an operation for eliminating an abnormality in the flow state in the pump 1. For example, the specific operation is an operation for increasing the number of strokes of the plunger 5 (high-speed operation) when the abnormality is a discharge abnormality caused by a gas lock. The specific operation includes an operation for urging the user to eliminate the abnormality, such as an operation for displaying a warning light or an operation for sounding an alarm.

[0037] The driver circuit 34 is a circuit that supplies a control current (applies a control voltage) to the motor 411 based on the control of the actuator control unit 311 (for example, an operation instruction for the motor 411) to control the operation of the motor 411. The driver circuit 34 includes a current detection circuit 341 that detects the control current value supplied to the motor 411. The control current value detected by the current detection circuit 341 is transmitted to the acquisition unit 312, for example, and acquired by the acquisition unit 312 in association with information (angle information) indicating the position angle of the motor 411 based on the operation instruction.

[0038] The storage unit 35 stores information (for example, a reference current value, a control current value, etc.) necessary for the operation of the pump 1. The storage unit 35 is, for example, a non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) or a flash memory.

[0039] FIG. 4 is a schematic diagram showing an example of information (reference current value) stored in the storage unit 35. As shown in FIG. The figure shows, for example, that two reference current values ​​"I1" and "I2" are stored in the storage unit 35. In this embodiment, the reference current value "I1" is a reference current value corresponding to an abnormality in the suction stroke, and the reference current value "I2" is a reference current value corresponding to an abnormality in the discharge stroke. The figure shows, for example, that the reference current value "I1" and the plunger position (specific position) "θ1" are associated with each other and stored in the storage unit 35. Here, the plunger position is calculated, for example, based on angle information and a reduction ratio between a drive gear 42 and a driven gear 43 described later.

[0040] In the present invention, the RAM 32 may function as the storage unit 35.

[0041] In the following description, primary reference will be made to FIGS. 1 and 2. The driving unit 4 reciprocates the plunger 5. The driving unit 4 includes a motor device 41, a driving gear 42, a driven gear 43, a crankshaft 44, and two bearings 45 and 46.

[0042] The motor device 41 generates a rotational power for reciprocating the plunger 5. The motor device 41 is a known stepping motor, and is an example of an electromagnetic actuator in the present invention. The motor device 41 includes a motor 411 and an encoder 413. The encoder 413 acquires a position angle of a rotating shaft 412 of the motor 411. A signal (angle information) indicating the position angle acquired by the encoder 413 is transmitted to the control device 3, and the control device 3 (actuator control unit 311) controls a control current value supplied to the motor 411 via the driver circuit 34. That is, the operation of the motor 411 is controlled by the control device 3 in a closed loop. Therefore, the motor 411 is controlled so as to always rotate accurately, and the power consumption (control current value) of the motor 411 is appropriately controlled according to the load of the motor 411. The motor device 41 is supported by the housing 2 with the rotating shaft 412 facing up and down.

[0043] The drive gear 42 and the driven gear 43 reduce the rotational power from the motor device 41 at a predetermined reduction ratio and transmit the reduced power to the crankshaft 44. The drive gear 42 is attached to a rotating shaft 412, and the driven gear 43 is attached to the crankshaft 44 so as to mesh with the drive gear 42.

[0044] The crankshaft 44 converts the rotational power from the motor device 41 into reciprocating power in the front-rear direction. The crankshaft 44 is rotatably supported by bearings 45, 46 such that the axial direction (longitudinal direction) is aligned along the up-down direction.

[0045] In the present invention, the drive unit 4 may include a rotating shaft and an eccentric cam instead of the crankshaft 44. In this case, the plunger 5 reciprocates by the eccentric cam and does not need to include a bearing 51 described later.

[0046] The bearing 45 rotatably supports an upper end of the crankshaft 44, and the bearing 46 rotatably supports a lower end of the crankshaft 44. The bearings 45 and 46 are supported by the housing 2.

[0047] The plunger 5 reciprocates in the front-rear direction in response to the rotation of the crankshaft 44, thereby reciprocating the diaphragm 6. The plunger 5 is housed in the machine chamber 22b so as to be aligned in the front-rear direction, and is rotatably attached to the crankshaft 44 via a bearing 51 provided in the plunger 5. The plunger 5 is disposed behind the diaphragm 6 (on the rear side of the diaphragm 6).

[0048] The operation of the plunger 5 is controlled by the control device 3 via the motor device 41. That is, when the control device 3 rotates the motor 411, the crankshaft 44 rotates, and the plunger 5 reciprocates in the front-rear direction. Here, when the plunger 5 is positioned at the rearmost position, that position corresponds to the bottom dead center of the plunger 5 (the 180° position in FIG. 3). When the plunger 5 advances forward from the bottom dead center, the diaphragm 6 is pushed forward, and the pumped fluid in the pump chamber 21a is discharged to the discharge flow passage 21c. At this time, the pump 1 is performing the discharge stroke. When the plunger 5 is positioned at the frontmost position, that position corresponds to the top dead center of the plunger 5 (the 0° / 360° position in FIG. 3). When the plunger 5 retreats backward from the top dead center, the diaphragm 6 is pulled back to the rear, and the pumped fluid is sucked from the suction flow passage 21b into the pump chamber 21a. At this time, the pump 1 is performing the suction stroke. In other words, when one reciprocating movement (one stroke) of the plunger 5 is considered to be one cycle, the pump 1 periodically repeats a discharge stroke and a suction stroke. The forward direction with respect to the plunger 5 is the forward direction in the present invention.

[0049] In this embodiment, the pump 1 operates in any one of the standard mode, the high viscosity mode, and the low pulsation mode based on the magnitude relationship between the forward speed and the return speed of the plunger 5. In other words, the operation modes of the pump 1 include the standard mode, the high viscosity mode, and the low pulsation mode.

[0050] FIG. 5 is a schematic diagram for explaining the operation modes of the pump 1, where (a) shows the standard mode, (b) shows the high viscosity mode, and (c) shows the low pulsation mode. The figure shows the elapsed time for each of the suction stroke and discharge stroke in one reciprocation (one cycle) of the plunger 5. The vertical axis of the figure shows the stroke amount of the plunger 5, and the horizontal axis shows the elapsed time. In the following explanation of the operation modes, Figures 1 and 2 will also be referred to as appropriate.

[0051] 5(a), the "standard mode" is an operation mode in which the time "To" for the plunger 5 to move from the bottom dead center to the top dead center (discharge stroke time) is set to be the same as the time "Tr" for the plunger 5 to move from the top dead center to the bottom dead center (suction stroke time). That is, in the standard mode, the forward speed "Vo" is set to be the same as the return speed "Vr" of the plunger 5.

[0052] As shown in FIG. 5(b), the "high viscosity mode" is an operating mode in which the discharge stroke time "To" is set to be shorter than the suction stroke time "Tr". That is, in the high viscosity mode, the forward speed "Vo" is set to be faster than the return speed "Vr" of the plunger 5. Generally, when a reciprocating pump sucks in a highly viscous liquid, if the return speed is fast, the required amount of the liquid is not sucked into the pump chamber 21a, and a mass of air bubbles is generated in the pump chamber 21a. In the present pump 1 operating in the high viscosity mode, the liquid is slowly sucked in, thereby suppressing the generation of air bubbles in the pump chamber 21a.

[0053] As shown in FIG. 5(c), the "low pulsation mode" is an operation mode in which the time "To" of the discharge stroke is set to be longer than the time "Tr" of the suction stroke. That is, in the low pulsation mode, the forward speed "Vo" is set to be slower than the return speed "Vr" of the plunger 5. In general, in a reciprocating pump, the discharge stroke and the suction stroke are alternately repeated, so that the pumped liquid is intermittently sent, and pulsation occurs. Here, the forward speed "Vo" becomes faster as the plunger 5 moves away from the bottom dead center, and becomes slower as the plunger 5 approaches the top dead center. Therefore, the flow velocity of the pumped liquid flowing through the discharge pipe L2 also accelerates and decelerates. The pulsation increases as the acceleration and deceleration of the flow velocity of the pumped liquid increases, and is suppressed as the acceleration and deceleration decrease. In the pump 1 operating in the low pulsation mode, the pumped liquid is discharged slowly, so that the flow velocity of the pumped liquid is slowly accelerated and decelerated, and pulsation is suppressed.

[0054] Here, the control current value increases or decreases according to the output (load) of the motor 411. That is, when the discharge pressure value increases, the output (load) of the motor 411 increases, and the control current value increases. On the other hand, when the discharge pressure value decreases, the output (load) of the motor 411 decreases, and the control current value decreases. Also, the control current value increases when the stroke number (i.e., the rotation speed of the motor 411) increases, and decreases when the stroke number decreases. Furthermore, when the stroke number decreases, the torque of the motor 411 increases, and when the stroke number increases, the torque of the motor 411 decreases. In the discharge stroke, the motor 411 requires a relatively high torque to discharge the handled liquid. Therefore, when the stroke number increases, the control current value tends to increase in order to obtain the required torque, and when the stroke number decreases, the control current value tends to decrease. In other words, even if the discharge pressure value is the same, the control current value required to discharge the handled liquid at that discharge pressure value increases as the stroke number increases, and decreases as the stroke number decreases. On the other hand, in the suction stroke, a high torque like that in the discharge stroke is not required, and the control current value tends to be stably small. This tendency is also shown in Figure 7, which will be described later.

[0055] Here, when the rotation speed of the motor 411 in the discharge stroke increases or decreases, the forward speed in the discharge stroke also increases or decreases. Therefore, in the discharge stroke, the control current value increases as the forward speed increases and decreases as the forward speed decreases. Therefore, when the forward speed changes, the control current value corresponding to the discharge pressure value also changes. As described above, in this embodiment, the operation modes of the pump 1 include the standard mode, the high viscosity mode, and the low pulsation mode, and each forward speed is different. Therefore, even if the position of the plunger 5 is the same, the control current value differs for each operation mode.

[0056] In the following description, primary reference will be made to FIGS. 1 and 2. The diaphragm 6 reciprocates to draw pumped fluid into the pump chamber 21a and discharge the pumped fluid from the pump chamber 21a. The diaphragm 6 is housed in the pump chamber 21a. The outer edge of the diaphragm 6 is fixed to the housing 2 with both surfaces of the diaphragm 6 facing in the front-rear direction.

[0057] The operation unit 7 is, for example, an operation panel that accepts operations by a user. The operation unit 7 is configured to allow the user to input and select the operating conditions of the pump 1 (operation mode, forward speed, return speed, number of strokes, etc.).

[0058] The connection unit 8 is, for example, a terminal block to which a cable (not shown, same below) is connected to an external device (not shown, same below) of the pump 1. The connection unit 8 is disposed, for example, on the rear surface of the housing 2. The connection unit 8 includes, for example, an input terminal 8a and an output terminal 8b.

[0059] The suction pipe L1 is a path for the pumped liquid to be sucked into the pump chamber 21a. The suction pipe L1 is connected to the suction flow path 21b. The discharge pipe L2 is a path for the pumped liquid discharged from the pump chamber 21a. The discharge pipe L2 is connected to the discharge flow path 21c.

[0060] The suction valve V1 is connected to the suction pipe L1 and is a one-way valve that allows the pumped fluid to flow only to the suction flow passage 21b side. The discharge valve V2 is connected to the discharge pipe L2 and is a one-way valve that allows the pumped fluid to flow only to the discharge pipe L2 side.

[0061] Operation of reciprocating pump (1) Next, the operation (method) of the pump 1 will be described below. In the following description, Figs. 1 to 3 will be referred to as appropriate.

[0062] FIG. 6 is a flow chart showing an example of the operation of the pump 1. In the following description of the operation, FIG. 6 will be referred to as appropriate.

[0063] First, the change detection unit 315 determines whether or not the operating conditions of the pump 1 (e.g., the operating mode, the number of strokes, the discharge pressure, etc.) have been changed (ST101: change determination step). The operating conditions are changed, for example, by the user operating the operation unit 7. The change detection unit 315 detects the change in the operating conditions based on, for example, a signal indicating a change in the operating conditions from the operation unit 7 (change signal), and determines that "the operating conditions have been changed."

[0064] When the change detection unit 315 determines that the "operating conditions have been changed" ("Y" in ST101), the acquisition unit 312 acquires the normal control current value (ST102: control current value acquisition step). Specifically, the acquisition unit 312 acquires, for example, the control current value transmitted from the current detection circuit 341 of the driver circuit 34 as the normal control current value for one stroke. At this time, the acquisition unit 312 also acquires, for example, angle information corresponding to each control current value in association with the control current value. The acquired control current value and angle information are, for example, associated with each other and stored in the storage unit 35. On the other hand, when the change detection unit 315 determines that the "operating conditions have not been changed" ("N" in ST101), the operation proceeds to processing (ST104).

[0065] In the process (ST101) immediately after the start of operation of the pump 1, the change detection unit 315 determines that "the operating conditions have been changed," and the processes (ST102, ST103) are executed.

[0066] Also, in the process (ST102), the acquisition unit 321 may acquire control current values ​​for several strokes and set the average of the control current values ​​as the normal control current value.

[0067] FIG. 7 is a schematic diagram showing an example of a normal control current value. In the figure, the control current value corresponding to one stroke (suction stroke and discharge stroke) of the plunger 5 is shown as an example of a normal control current value. In the figure, the pump 1 is operating at a discharge pressure of 0.5 MPa. The two-dot chain line in the figure indicates a specific position, and the dashed line in the figure indicates a reference current value.

[0068] Next, the setting unit 314 sets the reference current value based on the normal control current value (ST103: reference current value setting step). Specifically, the setting unit 314 specifies the control current value supplied to the motor 411 when the plunger 5 was located at the specific position based on, for example, specific position information indicating the specific position stored in the storage unit 35 and angle information, and sets the specified control current value as the reference current value. The reference current value is stored in, for example, the storage unit 35. At this time, if the previously set reference current value is stored in the storage unit 35, the storage unit 35 updates the reference current value with the newly set control current value and stores it.

[0069] Here, when the abnormality to be judged in the present invention is set in advance, the specific position information is, for example, written directly into the status judgment program or is stored in advance together with the status judgment program in the ROM 33. Also, when the abnormality is selectable by the user, the specific position information corresponding to each abnormality is, for example, stored in advance in the ROM 33.

[0070] In the present invention, the specific position information may be input by the user operating the operation unit 7 and stored in the storage unit 35, for example.

[0071] Next, the acquisition unit 312 acquires the specific current value (ST104: specific current value acquisition step). Specifically, the acquisition unit 312 acquires, as the specific current value, the latest control current value supplied to the motor 411 when the plunger 5 was located at the specific position, based on, for example, the specific position information and the angle information. The acquired specific current value is stored in, for example, the storage unit 35.

[0072] Next, the determination unit 313 calculates a difference between the reference current value and the specific current value (ST105: difference value calculation step), and compares the difference with a predetermined threshold value to determine the presence or absence of an abnormality at the specific position (ST106: state determination step). The predetermined threshold value is, for example, preset for each corresponding abnormality and stored in the storage unit 35.

[0073] In the present invention, the predetermined threshold value may be stored as a fixed value, or may be stored as a predetermined ratio to be multiplied by the difference value. In the latter case, when the control current value increases or decreases due to the operating conditions, the threshold value also increases or decreases.

[0074] When the difference value is less than the predetermined threshold value ("Y" in ST106), the determination unit 313 determines that "the flow state is normal (no abnormality)" (ST107).

[0075] Next, the determination unit 313 determines whether or not a specific operation, which will be described later, is being executed (ST108). When the determination unit 313 determines that "a specific operation is being executed" ("Y" in ST108), the specific operation control unit 316 ends the specific operation (ST109: specific operation end step), and the operation returns to the process (ST101). When the determination unit 313 determines that "a specific operation is not being executed" ("N" in ST108), the operation returns to the process (ST101).

[0076] On the other hand, when the difference value is equal to or greater than the predetermined threshold value ("N" in ST106), the determination unit 313 determines that "the flow state is abnormal (there is an abnormality)" (ST110).

[0077] FIG. 8 is a schematic diagram showing an example of the control current value when an abnormality occurs. In the figure, the control current value corresponding to one stroke of the plunger 5 (suction stroke and discharge stroke) is shown as an example of the control current value during an abnormality. In the figure, the pump 1 is operating at a discharge pressure of 0.5 MPa. The two-dot chain line in the figure indicates the specific position, and the dashed line in the figure indicates the specific current value. The figure shows the current value waveform when an abnormality (gas lock) occurs as an example of the control current value during an abnormality. As shown in Figures 7 and 8, when a gas lock occurs, the current value waveform in the discharge stroke is significantly deformed, there is a difference between the reference current value at the specific position and the specific current value, and the difference value in the difference region (the region indicated by a circle in Figure 8) is large.

[0078] Next, the determination unit 313 determines whether or not a specific operation, which will be described later, is being executed (ST111). When the determination unit 313 determines that "a specific operation is not being executed" ("N" in ST111), the specific operation control unit 316 executes control necessary for the specific operation (ST112: specific operation execution step). As a result, the specific operation is started. Next, this operation returns to the process (ST104).

[0079] On the other hand, when the determination unit 313 determines that "the specific action is being executed" ("Y" in ST111), the determination unit 313 determines whether the number of times the specific action has been executed has reached a predetermined number (ST113). Here, the "predetermined number" is preset for each specific action, and is stored in the ROM 33 together with the state determination program, for example.

[0080] When the determination unit 313 determines that the "number of executions is less than the predetermined number" ("N" in ST113), this operation returns to the process (ST104). On the other hand, when the determination unit 313 determines that the "number of executions has reached the predetermined number" ("Y" in ST113), the abnormality has not been resolved even after the specific operation has been performed the predetermined number of times, so the control device 3 (actuator control unit 311 and specific operation control unit 316) stops this operation (liquid delivery) (ST114).

[0081] In this way, the pump 1 stores the control current value (reference current value) at a specific position in a normal state among the control current values, and judges whether the flow state is normal or abnormal based on the difference value between the control current value (specific current value) at the specific position during operation. In other words, the pump 1 monitors the flow state based on the control current value. Therefore, the pump 1 can monitor the flow state in the pump 1 without using an abnormality detection device (e.g., a pressure gauge, a flow meter, etc.) that comes into contact with the handled liquid. As a result, the pump 1 does not require the cost burden for processing to attach a pressure gauge, sealing materials, discharge piping design and construction, wiring construction for the pressure gauge, etc., as in the case of conventional pumps equipped with a pressure gauge. Furthermore, the pump 1 can easily judge (monitor) the flow state in the pump 1 even if the handled liquid is a corrosive liquid.

[0082] In the process (ST106), the determination unit 313 may determine that "there is no abnormality" when the difference value is equal to or smaller than a predetermined threshold value, and may determine that "there is an abnormality" when the difference value is larger than the predetermined threshold value.

[0083] Summary (1) According to the embodiment described above, the pump 1 includes the diaphragm 6, the plunger 5, the pump chamber 21a, the motor device 41, the actuator control unit 311, the acquisition unit 312, the storage unit 35, and the determination unit 313. The storage unit 35 stores, as a reference current value, a normal control current value when at least the plunger 5 is located at a specific position, among the normal control current values. The actuator control unit 311 performs closed-loop control of the operation of the motor device 41. The acquisition unit 312 acquires, as a specific current value, a control current value when at least the plunger 5 is located at a specific position, among the control current values. The determination unit 313 determines whether the flow state is normal or abnormal based on the specific current value and the reference current value. The specific position is a position corresponding to a point where, when there is an abnormality in the flow state, a characteristic change corresponding to the abnormality appears in the current value waveform of the control current value for one stroke of the plunger 5. According to this configuration, the abnormality in the flow state appears in the control current value at the specific position. Therefore, the pump 1 can electrically acquire the specific current value and the reference current value, and determine whether or not there is an abnormality in the flow state based on the difference between the specific current value and the reference current value. That is, the pump 1 can monitor the flow state based on the control current value. Therefore, the pump 1 can monitor the flow state in the pump 1 without using an abnormality detection device (e.g., a pressure gauge, a flow meter, etc.) that comes into contact with the handled liquid. As a result, the pump 1 does not require the cost burden for processing to install a pressure gauge, sealing materials, discharge piping design and construction, wiring construction for the pressure gauge, etc., as in the case of a conventional pump equipped with a pressure gauge. Furthermore, the pump 1 can easily monitor (determine) the flow state in the pump 1 even if the handled liquid is a corrosive liquid.

[0084] Furthermore, according to the embodiment described above, the pump 1 includes a setting unit 314 that sets a reference current value based on the normal control current value acquired by the acquisition unit 312. With this configuration, the pump 1 can set an appropriate reference current value corresponding to an abnormality in the usage environment of the pump 1.

[0085] Furthermore, according to the embodiment described above, the pump 1 includes a change detection unit 315 that detects a change in the operating conditions of the pump 1. When the change detection unit 315 detects a change in the operating conditions, the acquisition unit 312 acquires a new normal control current value. The storage unit 35 updates and stores the reference current value based on the acquired new normal control current value. According to this configuration, the pump 1 can automatically update the reference current value in response to changes in the operating conditions in the usage environment of the pump 1. As a result, the pump 1 can appropriately set the reference current value in response to the control current value that increases or decreases in response to the operating conditions.

[0086] Furthermore, according to the embodiment described above, the pump 1 includes a specific operation control unit 316 that, when the determination unit 313 determines that "an abnormality exists," executes control necessary for a specific operation to resolve the abnormality. With this configuration, even if an abnormality occurs, the pump 1 can automatically execute a specific operation to resolve the abnormality.

[0087] In the present invention, the reference current value may include at least the normal control current value when the plunger 5 is located at the specific position, and is not limited to the normal control current value. That is, for example, the reference current value may be the normal control current value constituting the current value waveform in the difference region, may be the normal control current value constituting the current value waveform in the half-stroke region corresponding to the suction stroke or the discharge stroke, or may be the normal control current value constituting the current value waveform in the one-stroke region. Here, the one-stroke region, the half-stroke region, and the difference region are examples of the predetermined range in the present invention. In this case, the reference current value may be all of the normal control current values ​​constituting the current value waveform, or may be the average value thereof. Also, like the normal control current value, the specific current value may include the control current value when the plunger 5 is located at the specific position, and may be set according to the reference current value. That is, for example, the acquisition unit 312 may acquire a current value waveform belonging to the same region as the reference current value as the specific current value. In this case, the specific current value may be, for example, all of the control current values ​​constituting the current value waveform in the same region as the reference current value, or the average value thereof. In this way, when the reference current value and the specific current value are stored as waveforms within a specified range, the pump 1 can easily monitor the flow condition even when, for example, the specific position fluctuates greatly or the change (difference value) at the specific position is small (for example, when the discharge pressure value is small).

[0088] In the present embodiment, the reference current value may be set in advance and stored, for example, together with the state determination program in the ROM 33. In this case, the pump 1 may not include the setting unit 314 and the change detection unit 315.

[0089] Furthermore, in this embodiment, the determination unit 313 may determine not only the presence or absence of an abnormality but also the type of the abnormality. That is, for example, the memory unit 35 may store a plurality of reference current values ​​corresponding to a plurality of abnormalities, the acquisition unit 312 may acquire a plurality of specific current values ​​corresponding to the plurality of abnormalities, and the determination unit 313 may determine the presence or absence of an abnormality for each abnormality.

[0090] Furthermore, in this embodiment, the number of abnormalities determined by the determination unit 313 may be only "1" or may be multiple. In the former case, the determination unit 313 may determine the presence or absence of an abnormality in the flow state only in the discharge process or the suction process. In the latter case, the determination unit 313 may determine only the presence or absence of an abnormality, and may also determine the type of abnormality as described above.

[0091] Furthermore, in this embodiment, the horizontal axis of the current value waveform may be represented by the elapsed time from the start of operation of the pump 1, instead of the angle. In this case, the specific position may be represented by the time, instead of the angle.

[0092] ●Reciprocating pump (2)● Next, another embodiment of the present pump (hereinafter referred to as the "second embodiment") will be described below, focusing on the differences from the previously described embodiment (hereinafter referred to as the "first embodiment"). The second embodiment differs from the first embodiment in that a learning model is used to estimate the presence or absence of an abnormality. In the following description of the second embodiment, for convenience of explanation, the same components as those in the first embodiment and components having common functions are given the same reference numerals as those in the first embodiment, and detailed explanations will be omitted. In the following description, FIG. 1 will be referred to as appropriate.

[0093] ●Configuration of reciprocating pump (2) FIG. 9 is a functional block diagram showing a second embodiment of the present pump.

[0094] This pump 1A includes a housing 2, a control device 3A, a drive unit 4, a plunger 5, a diaphragm 6, an operation unit 7, a connection unit 8, a suction pipe L1, a discharge pipe L2, a suction valve V1, and a discharge valve V2.

[0095] The control device 3A controls the operation of the entire pump 1A. The control device 3A includes, for example, a CPU 31A, a RAM 32, a non-volatile memory such as a ROM 33A that stores various information such as a state estimation program, a driver circuit 34, and a storage unit 35A. The CPU 31A functions as an actuator control unit 311, an acquisition unit 312, a determination unit 313, a specific operation control unit 316, and an estimation unit 317. That is, the control device 3A also includes an actuator control unit 311, an acquisition unit 312, a determination unit 313, a specific operation control unit 316, and an estimation unit 317. The acquisition unit 312 also functions as a current value acquisition unit, a speed acquisition unit, and a stroke number acquisition unit in the present invention. The acquisition unit 312 is an example of a current value acquisition unit, a speed acquisition unit, and a stroke number acquisition unit in the present invention.

[0096] A state estimation program runs in the control device 3A, and the state estimation program cooperates with the hardware resources of the pump 1A to realize a state estimation method described below. By causing a processor (CPU 31A) included in the control device 3A to execute the state estimation program, the state estimation program can cause the processor to function as an actuator control unit 311, an acquisition unit 312, a determination unit 313, a specific operation control unit 316, and an estimation unit 317, and can cause the processor to execute the state estimation method. Furthermore, by causing a computer to execute the state estimation program, the state estimation program can cause the computer to function as the control device 3A.

[0097] The estimation unit 317 inputs the specific current value, the moving speed (forward speed and return speed), and the number of strokes into a learning model M1 described later, and estimates whether the flow state is normal or abnormal. The specific operation of the estimation unit 317 will be described later.

[0098] The storage unit 35A stores information (such as the learning model M1) necessary for the operation of the pump 1A. The storage unit 35A is, for example, a non-volatile memory such as an EEPROM or a flash memory.

[0099] FIG. 10 is a schematic diagram showing an example of information (learning model M1) stored in the storage unit 35A.

[0100] The "learning model M1" is a machine learning algorithm (i.e., a learning model) that has been trained to output whether the flow state is "normal" or "abnormal" when a control current value (e.g., a specific current value) "In" and predetermined operating conditions (forward speed "Vo", return speed "Vr", and stroke count "Sn") are input. The learning model M1 is, for example, generated in advance by a machine learning device and stored in the storage unit 35A.

[0101] Here, machine learning by the machine learning device is performed by, for example, having a known machine learning algorithm (for example, a neural network having an input layer, multiple intermediate layers, and an output layer) machine-learn the training data. The "training data" is, for example, information that serves as input data for the machine learning algorithm and information that serves as output data associated with the input data.

[0102] The "input data" is an explanatory variable in machine learning, and in the second embodiment, it is a predetermined operating condition (forward speed, return speed, and stroke count), a discharge pressure value under the same operating condition, and a specific current value (control current value at a specific position) under the same operating condition. As described above, when the moving speed (mainly forward speed) of the plunger 5 increases or decreases, the control current value also increases or decreases. Also, when the stroke count increases or decreases, the control current value also increases or decreases. Therefore, there is a correlation between the operating condition and the control current value. Furthermore, when the discharge pressure value increases, the output (load) of the motor 411 increases, and the control current value increases. On the other hand, when the discharge pressure value decreases, the output (load) of the motor 411 decreases, and the control current value decreases. Therefore, there is a correlation between the discharge pressure value and the control current value. The control current value (specific current value) and the discharge pressure value can be obtained, for example, by operating a test device simulating the present pump 1A equipped with a pressure gauge capable of measuring the discharge pressure value under the same operating condition for a predetermined period of time.

[0103] The "output data" is a target variable in machine learning, and in the second embodiment, is information indicating the operating state ("normal" or "abnormal") when the operation of the motor 411 is controlled by the input operating conditions and control current value (i.e., input data). In other words, the output data is information indicating the flow state ("normal" or "abnormal"). Numeric values ​​such as "0" and "1" are assigned to the "normal" and "abnormal" discharge pressures. One output data is associated with one corresponding input data to constitute one learning data.

[0104] In the second embodiment, the input data used for machine learning may not be the specific current value, but may be all or a part (for example, a part corresponding to a difference region) of the control current value (current value waveform) for one stroke of the plunger 5. In this case, the same type of information (all or a part of the control current value) as the input data used for machine learning is input to the learning model M1.

[0105] In addition, in the second embodiment, any one of the forward speed, backward speed, and number of strokes (for example, the number of strokes) may be calculated from the remaining two (forward speed, backward speed) and used for machine learning.

[0106] Furthermore, in the second embodiment, the machine learning algorithm used for machine learning is not limited to a neural network as long as the learning model M1 generated by machine learning can output a flow state. That is, for example, the machine learning algorithm may be a random forest, a decision tree, a support vector machine, or the like.

[0107] The learning model M1 thus generated is capable of outputting whether the flow state is "normal: 0" or "abnormal: 1" by inputting the (current) control current value "In" and predetermined operating conditions (forward speed "Vo", return speed "Vr", and stroke count "Sn") as shown in Fig. 10. That is, the learning model M1 has been machine-trained to output whether the flow state is "normal: 0" or "abnormal: 1" when the control current value "In", forward speed "Vo", return speed "Vr", and stroke count "Sn" are input as input data.

[0108] Operation of reciprocating pump (2) Next, the operation (state estimation method) of the pump 1A will be described below. In the following description, Figs. 1 and 9 will be referred to as appropriate.

[0109] FIG. 11 is a flow chart showing an example of the operation of the pump 1A.

[0110] First, the acquisition unit 312 acquires the current predetermined operating conditions (forward speed, return speed, and stroke count) of the pump 1A (ST201: operating condition acquisition step). Specifically, the forward speed and return speed are set in advance for each operating mode, for example, and are stored in the storage unit 35A as parameters of the operating conditions corresponding to the operating mode. The stroke count is input, for example, by the user operating the operation unit 7, and is stored in the storage unit 35A as a parameter of the operating conditions. The acquisition unit 312 acquires the current predetermined operating conditions from the storage unit 35A.

[0111] Next, the acquiring unit 312 acquires the specific current value (ST202: specific current value acquiring step) in the same manner as in the process (ST104).

[0112] Next, the estimation unit 317 inputs the predetermined operating conditions and the specific current value acquired by the acquisition unit 312 to the learning model M1, and estimates the flow state based on the output of the learning model M1 (ST203: flow state estimation step).

[0113] When the estimation unit 317 estimates that the "flow state is normal" ("normal" in ST203), the determination unit 313 determines whether or not a specific operation is being performed (ST204). When the determination unit 313 determines that a "specific operation is being performed" ("Y" in ST204), the specific operation control unit 316 ends the specific operation (ST205: specific operation end step), and the operation returns to the process (ST201). When the determination unit 313 determines that a "specific operation is not being performed" ("N" in ST204), the operation returns to the process (ST201).

[0114] On the other hand, when the estimation unit 317 estimates that the "flow state is abnormal" ("abnormal" in ST203), the determination unit 313 determines whether or not a specific operation is being performed (ST206). When the determination unit 313 determines that a "specific operation is not being performed" ("N" in ST206), the specific operation control unit 316 executes control necessary for the specific operation (ST207: specific operation execution step). As a result, the specific operation is started. Next, this operation returns to the process (ST201).

[0115] On the other hand, when the determination unit 313 determines that "the specific action is being executed" ("Y" in ST206), the determination unit 313 determines whether the specific action has been executed a predetermined number of times (ST208).

[0116] When the determination unit 313 determines that "the number of executions is less than the predetermined number of times" ("N" in ST208), this operation returns to the process (ST201). On the other hand, when the determination unit 313 determines that "the number of executions has reached the predetermined number of times" ("Y" in ST208), the abnormality has not been resolved even after the specific operation has been performed the predetermined number of times, so the control device 3 (actuator control unit 311 and specific operation control unit 316) stops this operation (liquid delivery) (ST209).

[0117] In this manner, in the pump 1A, the estimation unit 317 estimates the presence or absence of an abnormality in the flow state based on the predetermined operating conditions and the control current value (specific current value). In other words, the pump 1A detects an abnormality in the flow state based on the predetermined operating conditions and the control current value. Therefore, the pump 1A can monitor the flow state in the pump 1A without using an abnormality detection device (e.g., a pressure gauge, a flow meter, etc.) that comes into contact with the handled liquid. As a result, the pump 1A does not require the cost burden for processing to attach a pressure gauge, sealing materials, discharge piping design and construction, wiring construction for the pressure gauge, etc., as in the conventional pump equipped with a pressure gauge. Furthermore, the pump 1A can easily estimate the presence or absence of an abnormality in the flow state even if the handled liquid is a corrosive liquid. Furthermore, the pump 1 in the first embodiment does not require a reference current value, which is essential.

[0118] Summary (2) According to the second embodiment described above, the pump 1A includes an acquisition unit 312, a memory unit 35A, and an estimation unit 317. The acquisition unit 312 acquires a specific current value, a forward speed, a return speed, and a stroke count. The memory unit 35A stores a learning model M1. The estimation unit 317 inputs the specific current value, the forward speed, the return speed, and the stroke count into the learning model M1 to estimate whether the flow state is normal or abnormal. With this configuration, the pump 1A can monitor the flow state in the pump 1A without using an abnormality detection device that comes into contact with the handled liquid.

[0119] In the second embodiment, among the input data for machine learning of the learning model M1, information other than the specific current value (predetermined operating conditions) may be appropriately set according to the usage environment of the pump 1A, and is not limited to the forward speed, return speed, and number of strokes. That is, for example, when the pump 1A is used under fixed operating conditions, the input data for machine learning may be only the specific current value. Also, when the operation mode of the pump 1A is fixed and used, the input data for machine learning may be only the specific current value and the number of strokes (or the forward speed and / or return speed). In these cases, the information input to the learning model M1 may be information corresponding to the input data for machine learning.

[0120] In the second embodiment, if the estimated abnormality is only an abnormality occurring during the discharge process, the input data for machine learning may not include the return speed. Similarly, if the estimated abnormality is only an abnormality occurring during the suction process, the input data for machine learning may not include the forward speed. In these cases, the information input to the learning model M1 may be information corresponding to the input data for machine learning.

[0121] Furthermore, in the second embodiment, the input data for the machine learning of the learning model M1 may include other information (for example, a discharge pressure value, etc.).

[0122] Furthermore, in the second embodiment, the storage unit 35A may store a plurality of types of learning models M1 corresponding to a plurality of abnormalities, respectively.

[0123] ●Reciprocating pump(3)● Next, yet another embodiment of the present pump (hereinafter referred to as the "third embodiment") will be described below, focusing on the differences from the first and second embodiments described above. The third embodiment differs from the first and second embodiments in that a learning model is used to predict the presence or absence of future abnormalities. In the following description of the second embodiment, for convenience of explanation, the same components as those in the first embodiment and components having common functions are given the same reference numerals as those in the first embodiment, and detailed explanations will be omitted. In the following description, FIG. 1 will be referred to as appropriate.

[0124] ●Configuration of reciprocating pump (3) FIG. 12 is a functional block diagram showing a third embodiment of the present pump.

[0125] This pump 1B includes a housing 2, a control device 3B, a drive unit 4, a plunger 5, a diaphragm 6, an operation unit 7, a connection unit 8, a suction pipe L1, a discharge pipe L2, a suction valve V1, and a discharge valve V2.

[0126] The control device 3B controls the operation of the entire pump 1B. The control device 3B includes, for example, a CPU 31B, a RAM 32, a non-volatile memory such as a ROM 33B that stores various information such as a state prediction program, a driver circuit 34, and a storage unit 35B. The CPU 31B functions as an actuator control unit 311, an acquisition unit 312, a specific operation control unit 316, a calculation unit 318, and a prediction unit 319. That is, the control device 3 also includes an actuator control unit 311, an acquisition unit 312, a specific operation control unit 316, a calculation unit 318, and a prediction unit 319. The acquisition unit 312 also functions as a current value acquisition unit, a speed acquisition unit, and a stroke number acquisition unit in the present invention. The acquisition unit 312 is an example of a current value acquisition unit, a speed acquisition unit, and a stroke number acquisition unit in the present invention.

[0127] A state prediction program runs in the control device 3B, and the state prediction program cooperates with the hardware resources of the pump 1B to realize a state prediction method described below. By causing a processor (CPU 31B) included in the control device 3B to execute the prediction program, the state prediction program can cause the processor to function as an actuator control unit 311, an acquisition unit 312, a specific operation control unit 316, a calculation unit 318, and a prediction unit 319, and cause the processor to execute the state prediction method. Furthermore, by causing a computer to execute the state prediction program, the state prediction program can cause the computer to function as the control device 3B.

[0128] The calculation unit 318 calculates the amount of change between a reference specific current value and the latest specific current value among a plurality of specific current values ​​acquired at a predetermined sampling interval. The specific operation of the calculation unit 318 will be described later.

[0129] The "predetermined sampling interval" is indicated, for example, by the number of strokes of the plunger 5, and in this embodiment, it is several thousand to several tens of thousands of strokes.

[0130] The "reference specific current value" is, for example, a specific current value obtained at a time when there is clearly no abnormality in the flow condition of the handled liquid (for example, immediately after the installation of this pump 1B, immediately after maintenance of this pump 1B, etc.).

[0131] In the present invention, the calculation unit 318 may calculate the amount of change between two specific current values ​​acquired consecutively at a predetermined sampling interval. In this case, the specific current value serving as the reference is the specific current value acquired at the timing immediately before the latest specific current value. In this case, the input data for machine learning also includes the same amount of change.

[0132] The prediction unit 319 inputs the amount of change, the moving speed (forward speed and return speed), and the number of strokes into a learning model M2 described later, and predicts whether or not an abnormality in the flow state will occur in a preset future period (hereinafter referred to as the "prediction period"). The specific operation of the prediction unit 319 will be described later.

[0133] The "prediction period" is, for example, a few hours, one day, several days, one week, etc. The prediction period is set as a fixed period during machine learning, which will be described later, for example.

[0134] The storage unit 35B stores information (such as the learning model M2) necessary for the operation of the pump 1B. The storage unit 35B is, for example, a non-volatile memory such as an EEPROM or a flash memory.

[0135] FIG. 13 is a schematic diagram showing an example of information (learning model M2) stored in the storage unit 35B.

[0136] The "learning model M2" is a trained machine learning algorithm (i.e., a learning model) that has been trained to output the presence or absence of an abnormality in the flow state (i.e., a predicted flow state) after a prediction period has elapsed when the amount of change "ΔI" and predetermined operating conditions (forward speed "Vo", return speed "Vr", and number of strokes "Sn") are input. The learning model M2 is generated in advance by, for example, a machine learning device, and is stored in the storage unit 35B in association with, for example, information indicating the prediction period corresponding to the learning model M2.

[0137] Here, there are abnormalities in the suction state or discharge state that occur over time and in stages. The timing of occurrence of the abnormality that increases or decreases the control current value over time from the initial stage to the final stage of the abnormality can be predicted to some extent by tracking the amount of change in the control current value. In addition, the progress of the abnormality varies depending on the operating conditions. That is, for example, if the abnormality is an abnormality related to deterioration of the diaphragm 6, the progress becomes faster as the number of strokes increases. Therefore, the amount of change and the predetermined operating conditions are used as machine learning input data for the machine learning algorithm of the third embodiment.

[0138] The output data of the machine learning of the machine learning algorithm of the third embodiment is the presence or absence of an abnormality in the suction state or the discharge state after the prediction period has elapsed.

[0139] The learning model M2 thus generated is capable of outputting whether the predicted flow state is "normal prediction: 0" or "abnormal prediction: 1" by inputting the amount of change "ΔI" and predetermined operating conditions (forward speed "Vo", return speed "Vr", and number of strokes "Sn") as shown in Fig. 13. That is, the learning model M2 is machine-trained to output whether the predicted flow state is "normal prediction: 0" or "abnormal prediction: 1" when the amount of change "ΔI", forward speed "Vo", return speed "Vr", and number of strokes "Sn" are input as input data.

[0140] Operation of reciprocating pump (3) Next, the operation (prediction method) of the pump 1B will be described below. In the following description, FIG. 12 will be referred to as appropriate.

[0141] FIG. 14 is a flow chart showing an example of the operation of the pump 1B.

[0142] First, the acquisition unit 312 acquires the current predetermined operating conditions (forward speed, return speed, and stroke count) of the pump 1B, similarly to the process (ST201) (ST301: operating condition acquisition step).

[0143] Next, the acquiring unit 312 acquires the specific current value at a predetermined sampling interval (ST302: specific current value acquiring step). At this time, the specific current value serving as a reference is stored as a reference specific current value in, for example, the storage unit 35B.

[0144] Next, the calculation unit 318 calculates the amount of change between the reference specific current value and the latest specific current value (ST303). Here, the amount of change may be the difference between the two specific current values, or may be the rate of change in the current value between the two specific current values.

[0145] Next, the prediction unit 319 inputs the amount of change and the predetermined operating conditions (forward speed, return speed, and number of strokes) into the learning model M2, and predicts whether or not an abnormality will occur in the suction state or discharge state (flow state) during the prediction period based on the output of the learning model M2 (ST304). Here, the prediction period is set during the machine learning of the learning model M2.

[0146] When the prediction unit 319 predicts that "an abnormality exists", i.e., that the "flow state is abnormal" ("abnormal" in ST304), the specific operation control unit 316 executes the control required for the specific operation (ST305: specific operation execution step). At this point, no abnormality has occurred in the flow of the handled liquid. Therefore, in the third embodiment, the specific operation is an operation to display a warning light or an operation to sound an alarm. Such an operation is an operation to prevent the occurrence of future abnormalities, and can be included in the specific operation in a broad sense. Next, this operation returns to the process (ST302).

[0147] On the other hand, when the prediction unit 319 predicts that there is "no abnormality", that is, that the "flow state is normal" ("normal" in ST304), the operation returns to the process (ST302).

[0148] In this manner, in the pump 1B, the prediction unit 319 predicts the presence or absence of an abnormality in the flow state during the prediction period based on the amount of change and the predetermined operating conditions. In other words, the pump 1B predicts the occurrence of an abnormality in the flow state based on the amount of change and the operating state. Therefore, the pump 1B can monitor the flow state of the handled liquid in the pump 1B without using an abnormality detection device (e.g., a pressure gauge, a flow meter, etc.) that comes into contact with the handled liquid. As a result, the pump 1B does not require the cost burden for processing to attach a pressure gauge, sealing materials, discharge piping design and construction, wiring construction for the pressure gauge, etc., as in the conventional pump equipped with a pressure gauge. Furthermore, the pump 1B can easily estimate the presence or absence of an abnormality in the suction state and / or discharge state even if the handled liquid is a corrosive liquid. Furthermore, the pump 1 in the first embodiment does not require a reference current value, which is essential.

[0149] ● Summary (3) According to the embodiment described above, the pump 1B includes an acquisition unit 312, a storage unit 35B, a calculation unit 318, and a prediction unit 319. The acquisition unit 312 acquires a specific current value, a forward speed, a return speed, and a stroke count. The storage unit 35B stores a learning model M2. The calculation unit 318 calculates a change amount between a reference specific current value and the latest specific current value among a plurality of specific current values ​​acquired at a predetermined sampling interval. The prediction unit 319 inputs the change amount, the forward speed, the return speed, and the stroke count into the learning model M2 to estimate whether an abnormality will occur in the flow state after the prediction period has elapsed. According to this configuration, the pump 1B can monitor the flow state of the handled liquid in the pump 1B without using an abnormality detection device that comes into contact with the handled liquid.

[0150] In the third embodiment, among the input data for the machine learning of the learning model M2, information other than the amount of change (predetermined operating conditions) may be appropriately set according to the usage environment of the pump 1B, and is not limited to the forward speed, return speed, and number of strokes. That is, for example, when the pump 1B is used under fixed operating conditions, the input data for the machine learning may be only the amount of change. Also, when the operation mode of the pump 1B is fixed and used, the input data for the machine learning may be only the amount of change and the number of strokes (or the forward speed and / or return speed). In these cases, the information input to the learning model M2 may be information corresponding to the input data for the machine learning.

[0151] In the third embodiment, when the estimated abnormality is only an abnormality occurring during the discharge process, the input data for machine learning does not need to include the return speed. Similarly, when the estimated abnormality is only an abnormality occurring during the suction process, the input data for machine learning does not need to include the forward speed. In these cases, the information input to the learning model M2 may be information corresponding to the input data for machine learning.

[0152] Furthermore, in the third embodiment, the input data for the machine learning of the learning model M2 may include other information (for example, a discharge pressure value, etc.).

[0153] Furthermore, in the third embodiment, the memory unit 35B may store multiple types of learning models M2 corresponding to each of multiple anomalies, or may store multiple types of learning models M2 corresponding to each of multiple prediction periods.

[0154] ●Other embodiments● In the present invention, the electromagnetic actuator is not limited to a stepping motor. That is, for example, the electromagnetic actuator may be a known solenoid (capable of closed-loop control) equipped with a position sensor that detects the position of the moving axis, or a servo motor.

[0155] In the present invention, the operation modes of the pumps 1, 1A, and 1B are not limited to the standard mode, the high viscosity mode, and the low pulsation mode. The operation modes of the pump 1 do not necessarily have to include any of these operation modes.

[0156] Furthermore, in the present invention, the pumps 1, 1A, and 1B may include, instead of the current detection circuit 341 of the driver circuit , another current detection circuit capable of detecting a control current value.

[0157] Furthermore, in the present invention, the abnormality in the flow state is not limited to gas lock or cavitation as long as it is an abnormality that affects the flow of the pumped liquid in the pumps 1, 1A, 1B and causes a characteristic change in the control current value. That is, for example, the abnormality in the flow state may be an abnormality in the pumped liquid itself (e.g., freezing of the pumped liquid, change in viscosity, etc.) or an abnormality caused by something outside the pump chamber 21a (e.g., leakage or clogging of the suction flow path 21b or the discharge flow path 21c, wear of the drive gear 42, the driven gear 43, or the bearings 45 and 46, etc.).

[0158] ●Embodiments of the present invention● Next, the embodiments of the present invention that can be understood from the above-described embodiments will be described below, using the terms and symbols described in the respective embodiments.

[0159] A first embodiment of the present invention is a reciprocating pump (e.g., reciprocating pump 1) that sucks and discharges a pumped liquid by reciprocating a diaphragm (e.g., diaphragm 6), and includes the diaphragm, a pump chamber (e.g., pump chamber 21a) in which the diaphragm is accommodated, a plunger (e.g., plunger 5) that reciprocates the diaphragm, an electromagnetic actuator (e.g., motor device 41) that reciprocates the plunger, an actuator control unit (e.g., actuator control unit 311) that performs closed-loop control of the operation of the electromagnetic actuator, and a control current value used to control the operation of the electromagnetic actuator, at least when the plunger is located at a specific position within one stroke of the plunger. a memory unit (e.g., memory unit 35) that stores, as a reference current value, at least the normal control current value when the plunger is positioned at the specific position, among normal control current values ​​which are the control current values ​​when the suction state and discharge state of the pumped fluid are normal; and a judgment unit (e.g., judgment unit 313) that judges whether the suction state and / or the discharge state are normal or abnormal based on the specific current value and the reference current value, wherein the specific position is a position corresponding to a point at which a characteristic change corresponding to the abnormality appears in the current value waveform of the control current value for one stroke of the plunger when the abnormality exists. According to this configuration, the flow state in the pump can be monitored without using an abnormality detection device (such as a pressure gauge or a flow meter) that is in contact with the pumped liquid.

[0160] A second embodiment of the present invention is a reciprocating pump in the first embodiment, comprising a reference acquisition unit (e.g., acquisition unit 312) that acquires the normal control current value, and a setting unit (e.g., setting unit 314) that sets the reference current value based on the normal control current value acquired by the reference acquisition unit. According to this configuration, the pump can set an appropriate reference current value that corresponds to an abnormality in the environment in which the pump is used.

[0161] A third embodiment of the present invention is a reciprocating pump in the second embodiment, further comprising a change detection unit (e.g., change detection unit 315) that detects a change in operating conditions of the reciprocating pump, and when the change detection unit detects a change in the operating conditions, the reference acquisition unit acquires the normal control current value, and the memory unit updates and stores the reference current value based on the acquired normal control current value. According to this configuration, the pump can appropriately set the reference current value in accordance with the control current value that increases or decreases depending on the operating conditions.

[0162] A fourth embodiment of the present invention is a reciprocating pump comprising, in the first embodiment, a specific operation control unit (e.g., specific operation control unit 316) that executes control necessary for a specific operation to eliminate the abnormality when the judgment unit judges that the abnormality exists in the suction state or the discharge state. According to this configuration, even if an abnormality occurs, the pump can automatically perform a specific operation to resolve the abnormality.

[0163] A fifth embodiment of the present invention is a reciprocating pump, wherein in any one of the first to fourth embodiments, the memory unit stores the current value waveform of the normal control current value used to control the plunger in a predetermined range of strokes including the specific position as the reference current value, and the acquisition unit acquires the current value waveform of the control current value used to control the plunger in the predetermined range of strokes as the specific current value. With this configuration, the pump can easily monitor flow conditions when the specific location varies widely, even when the changes in the specific location are small.

[0164] A sixth embodiment of the present invention is a reciprocating pump (e.g., reciprocating pump 1A) that sucks and discharges a pumped liquid by reciprocating a diaphragm (e.g., diaphragm 6), and includes the diaphragm, a pump chamber (e.g., pump chamber 21a) in which the diaphragm is accommodated, a plunger (e.g., plunger 5) that reciprocates the diaphragm, an electromagnetic actuator (e.g., motor device 41) that reciprocates the plunger, an actuator control unit (e.g., actuator control unit 311) that performs closed-loop control of the operation of the electromagnetic actuator, and a current value acquisition unit (e.g., acquisition unit 312) that acquires, as a specific current value, the control current value when at least the plunger is located at a specific position within the stroke of one stroke of the plunger, among the control current values ​​used to control the operation of the electromagnetic actuator, and the plunger a speed acquisition unit (e.g., acquisition unit 312) that acquires the movement speed of the plunger; a stroke number acquisition unit (e.g., acquisition unit 312) that acquires the stroke number of the plunger; a memory unit (e.g., memory unit 35A) that stores a trained learning model (e.g., learning model M1) that has been machine-learned to output whether the suction state or the discharge state of the handled fluid is normal or abnormal when the specific current value, the movement speed, and the stroke number are input; and an estimation unit (e.g., estimation unit 317) that inputs the specific current value, the movement speed, and the stroke number into the learning model to estimate whether the suction state or the discharge state is normal or abnormal, wherein the specific position is a position corresponding to a point at which a characteristic change corresponding to the abnormality appears in the current value waveform of the control current value for one stroke of the plunger when the abnormality exists. According to this configuration, the flow state in the pump can be monitored without using an abnormality detection device (such as a pressure gauge or a flow meter) that is in contact with the pumped liquid.

[0165] A seventh embodiment of the present invention is a reciprocating pump (e.g., reciprocating pump 1B) that sucks and discharges a pumped liquid by reciprocating a diaphragm (e.g., diaphragm 6), the diaphragm, a pump chamber (e.g., pump chamber 21a) in which the diaphragm is accommodated, a plunger (e.g., plunger 5) that reciprocates the diaphragm, an electromagnetic actuator (e.g., motor device 41) that reciprocates the plunger, an actuator control unit (e.g., actuator control unit 311) that performs closed-loop control of the operation of the electromagnetic actuator, and a current value acquisition unit (e.g., acquisition unit 312) that acquires, as a specific current value, the control current value when at least the plunger is located at a specific position within the stroke of the plunger, among the control current values ​​used for controlling the operation of the electromagnetic actuator, and a change amount between the specific current value that is a reference and the latest specific current value among the plurality of specific current values ​​acquired at a predetermined sampling interval. a calculation unit (e.g., calculation unit 318), a speed acquisition unit (e.g., acquisition unit 312) that acquires the movement speed of the plunger, a stroke number acquisition unit (e.g., acquisition unit 312) that acquires the stroke number of the plunger, a memory unit (e.g., memory unit 35B) that stores a trained learning model (e.g., learning model M2) that has been machine-learned to output the presence or absence of an abnormality in the suction state or discharge state of the handled fluid after a predetermined future period has elapsed when the specific current value, the change amount, the movement speed, and the stroke number are input, and a prediction unit (e.g., prediction unit 319) that inputs the specific current value, the change amount, the movement speed, and the stroke number into the learning model and predicts whether the abnormality will occur in the suction state or the discharge state within the period, wherein the specific position is a position corresponding to a point at which a characteristic change corresponding to the abnormality appears in the current value waveform of the control current value for one stroke of the plunger when the abnormality occurs. According to this configuration, the flow state in the pump can be monitored without using an abnormality detection device (such as a pressure gauge or a flow meter) that is in contact with the pumped liquid.

[0166] An eighth embodiment of the present invention is a method for monitoring a flow state of a handled liquid, which is executed by a reciprocating pump including a diaphragm, a pump chamber in which the diaphragm is accommodated, a plunger that reciprocates the diaphragm, an electromagnetic actuator that reciprocates the plunger, an actuator control unit that performs closed-loop control of the operation of the electromagnetic actuator, and a memory unit that stores a reference current value among control current values ​​used to control the operation of the electromagnetic actuator, and which determines whether a suction state and / or a discharge state of the handled liquid are normal or abnormal, and the reference current value is a normal control current value that is the control current value when the suction state and the discharge state are normal, at least when the plunger is within one stroke of the plunger. the normal control current value when the plunger was located at a specific position in the flow state monitoring method, the specific position being a position corresponding to a point at which a characteristic change corresponding to the abnormality appears in a current value waveform of the control current value for one stroke of the plunger when the abnormality exists, and the flow state monitoring method includes a step of the reciprocating pump acquiring, as a specific current value, among the control current values, at least the control current value when the plunger was located at the specific position (e.g., a specific current value acquisition step: ST104), and a step of the reciprocating pump judging whether the suction state and / or the discharge state is normal or abnormal based on the specific current value and the reference current value (e.g., a state judgment step: ST106). According to this configuration, the flow state in the pump can be monitored without using an abnormality detection device (such as a pressure gauge or a flow meter) that is in contact with the pumped liquid. [Explanation of symbols]

[0167] 1 Reciprocating Pump 21a Pump room 311 Actuator control section 312 Acquisition unit (reference acquisition unit, current value acquisition unit, speed acquisition unit, stroke number acquisition unit) 313 Judgment section 314 Settings 315 Change detection unit 316 Specific operation control unit 35 Storage section 41 Motor devices (electromagnetic actuators, stepping motors) 411 Motor 5 Plunger 6 Diaphragm 7 Control section 1A reciprocating pump 317 Estimation Department 35A storage section M1 Learning Model 1B Reciprocating Pump 318 Calculation Department 319 Prediction Department 35B Storage section M2 Learning Model

Claims

1. A reciprocating pump that sucks and discharges pumped liquid by reciprocating a diaphragm, The diaphragm; a pump chamber in which the diaphragm is accommodated; A plunger that reciprocates the diaphragm; an electromagnetic actuator for reciprocating the plunger; an actuator control unit that performs closed-loop control of the operation of the electromagnetic actuator; an acquisition unit that acquires, as a specific current value, a control current value used to control an operation of the electromagnetic actuator when the plunger is located at a specific position within one stroke of the plunger, and acquires angle information corresponding to the control current value in association with the control current value; a storage unit that stores, as a reference current value, a normal control current value when the plunger is located at the specific position, among normal control current values ​​that are the control current values ​​when the suction state and the discharge state of the pumped fluid are normal, in association with the angle information corresponding to the reference current value; a determination unit that determines whether the suction state and / or the discharge state is normal or abnormal based on the specific current value and the reference current value; a reference acquisition unit for acquiring the normal control current value; a setting unit that sets the reference current value based on the normal control current value acquired by the reference acquisition unit; A change detection unit that detects a change in an operating condition of the reciprocating pump; and the angle information is information indicating a position of the plunger within one stroke of the plunger, the specific position is a position corresponding to a point at which a characteristic change corresponding to the abnormality appears in a current value waveform of the control current value for one stroke of the plunger when the abnormality exists, When the change detection unit detects a change in the operating condition, the reference acquisition unit acquires the normal control current value in association with the angle information corresponding to the normal control current value, the storage unit updates and stores the reference current value based on the acquired normal control current value and the angle information associated with the normal control current value. Reciprocating pump.

2. a specific operation control unit that executes control necessary for a specific operation to eliminate the abnormality when the determination unit determines that the abnormality exists in the suction state or the discharge state; It is made of 2. The reciprocating pump of claim 1.

3. the storage unit stores, as the reference current value, a current value waveform of the normal control current value used to control the plunger in a stroke within a predetermined range including the specific position; The acquisition unit acquires, as the specific current value, a current value waveform of the control current value used to control the plunger in the predetermined range of stroke.

3. The reciprocating pump according to claim 1 or 2.

4. A reciprocating pump that sucks and discharges pumped liquid by reciprocating a diaphragm, The diaphragm; a pump chamber in which the diaphragm is accommodated; A plunger that reciprocates the diaphragm; an electromagnetic actuator for reciprocating the plunger; an actuator control unit that performs closed-loop control of the operation of the electromagnetic actuator; a current value acquisition unit that acquires, as a specific current value, a control current value used to control an operation of the electromagnetic actuator when the plunger is located at a specific position within one stroke of the plunger; A speed acquisition unit that acquires a moving speed of the plunger; A stroke number acquisition unit that acquires a stroke number of the plunger; A memory unit that stores a learned learning model that has been machine-learned to output whether the suction state or the discharge state of the handled liquid is normal or abnormal when the specific current value, the moving speed, and the number of strokes are input; an estimation unit that inputs the specific current value, the moving speed, and the number of strokes into the learning model to estimate whether the suction state or the discharge state is normal or abnormal; and the specific position is a position corresponding to a point at which a characteristic change corresponding to the abnormality appears in a current value waveform of the control current value for one stroke of the plunger when the abnormality exists; Reciprocating pump.

5. A reciprocating pump that sucks and discharges pumped liquid by reciprocating a diaphragm, The diaphragm; a pump chamber in which the diaphragm is accommodated; A plunger that reciprocates the diaphragm; an electromagnetic actuator for reciprocating the plunger; an actuator control unit that performs closed-loop control of the operation of the electromagnetic actuator; a current value acquisition unit that acquires, as a specific current value, a control current value used to control an operation of the electromagnetic actuator when the plunger is located at a specific position within one stroke of the plunger; a calculation unit that calculates an amount of change between a reference specific current value and a latest specific current value among a plurality of specific current values ​​acquired at a predetermined sampling interval; A speed acquisition unit that acquires a moving speed of the plunger; A stroke number acquisition unit that acquires a stroke number of the plunger; a memory unit that stores a learned learning model that has been machine-learned to output the presence or absence of an abnormality in the suction state or discharge state of the handled liquid after a preset future period has elapsed when the specific current value, the amount of change, the moving speed, and the number of strokes are input; a prediction unit that inputs the specific current value, the amount of change, the moving speed, and the number of strokes into the learning model and predicts whether or not the abnormality will occur in the suction state or the discharge state within the period; and the specific position is a position corresponding to a point at which a characteristic change corresponding to the abnormality appears in a current value waveform of the control current value for one stroke of the plunger when the abnormality occurs; Reciprocating pump.

6. A diaphragm; a pump chamber in which the diaphragm is accommodated; A plunger that reciprocates the diaphragm; an electromagnetic actuator for reciprocating the plunger; an actuator control unit that performs closed-loop control of the operation of the electromagnetic actuator; a storage unit that stores a reference current value among control current values ​​used to control the operation of the electromagnetic actuator in association with angle information corresponding to the reference current value; A method for monitoring a flow state of a pumped liquid, which is performed by a reciprocating pump having a pumping mechanism, and which determines whether a suction state and / or a discharge state of the pumped liquid is normal or abnormal, the reference current value is, among normal control current values ​​which are the control current values ​​when the suction state and the discharge state are normal, the normal control current value at least when the plunger is located at a specific position within one stroke of the plunger, the specific position is a position corresponding to a point at which a characteristic change corresponding to the abnormality appears in a current value waveform of the control current value for one stroke of the plunger when the abnormality exists, the angle information is information indicating a position of the plunger within one stroke of the plunger, The flow condition monitoring method includes: detecting a change in an operating condition of the reciprocating pump; When the reciprocating pump detects a change in the operating condition, acquiring the normal control current value in association with the angle information corresponding to the normal control current value; a step of the reciprocating pump setting the reference current value based on the acquired normal control current value and the angle information stored in the storage unit in association with the normal control current value; a step of the reciprocating pump acquiring, as a specific current value, among the control current values, at least the control current value when the plunger is located at the specific position, and acquiring the angle information corresponding to the control current value in association with the control current value; determining whether the suction state and / or the discharge state is normal or abnormal based on the specific current value and the reference current value by the reciprocating pump; Including, Flow condition monitoring method.

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