Plunger pump, abnormality detection device for plunger pump, and plunger system

Abstract

To predict a failure of a plunger pump.SOLUTION: A plunger pump comprises a drive part, a shaft member which can reciprocate in a linear direction by receiving a drive force from the drive part, a magnet which can move integrally with the reciprocation of the shaft member, and a coil for generating an induction current by a change of a position relative to the magnet according to the movement of the shaft member.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a plunger pump, an abnormality detection device for a plunger pump, and a plunger pump system. [Background technology]

[0002] For example, a plunger pump used in a coating device or the like includes a motor unit that generates a driving force and a pump unit that is driven by the motor unit. The pump unit has a cylindrical pump case and a plunger that is connected to a shaft member of the motor unit and moves linearly back and forth within the pump case. The back and forth movement of the plunger sucks in and discharges a coating liquid such as paint.

[0003] In order to ensure that such a plunger pump operates normally, it is desirable to determine whether or not there is an abnormality in the plunger pump. One known method for detecting an abnormality in a plunger pump is to count the number of cycles of the reciprocating movement of the shaft member and plunger based on the results detected by an air-to-electricity converter or the like provided in the motor, and determine that there is an abnormality in the plunger pump if the timing of the count is not consistent over a predetermined period.

[0004] However, this method determines whether an abnormality exists based on information provided intermittently according to the cycle of reciprocating movement of the shaft member and plunger. Therefore, if an abnormality is detected, the plunger pump may already be broken, requiring unexpected maintenance. This type of maintenance is undesirable because it requires changes to work plans. On the other hand, while preventive maintenance of the plunger pump can be considered to prevent breakdowns, it poses maintenance challenges because parts must be replaced at set intervals. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-74745 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a plunger pump, an abnormality detection device for a plunger pump, and a plunger pump system that are capable of realizing failure prediction. [Means for solving the problem]

[0007] The plunger pump of this embodiment comprises a drive unit, a shaft member that can move back and forth in a linear direction upon receiving a drive force from the drive unit, a magnet that can move integrally with the back and forth movement of the shaft member, and a coil that generates an induced current as its relative position with the magnet changes in accordance with the movement of the shaft member.

[0008] An embodiment of an abnormality detection device for a plunger pump is connected to a plunger pump for detecting an abnormal state of the plunger pump, and includes a detection unit that detects an induced current generated in the coil, a setting processing unit that is capable of executing a setting process to set information based on the waveform of the induced current generated in the coil when the shaft member is moved back and forth in a normal state as a reference value, and a judgment processing unit that is capable of executing a judgment process to detect an abnormality in the plunger pump by comparing a detection value based on information based on the waveform of the actual induced current generated in the coil detected by the detection unit with the reference value.

[0009] The plunger pump system of one embodiment comprises a plunger pump, a detection unit connected to the plunger pump and detecting the induced current generated in the coil, an output unit that outputs information obtained from the plunger pump to a user, a setting processing unit capable of executing a setting process to set information based on the waveform of the induced current generated in the coil when the shaft member is moved back and forth in a normal state as a reference value, a judgment processing unit capable of executing a judgment process to detect an abnormality in the plunger pump by comparing a detection value based on information based on the waveform of the actual induced current generated in the coil detected by the detection unit with the reference value, and an output processing unit capable of executing an output process to output to the output unit if an abnormality in the plunger pump is detected by the judgment process. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing an example of a plunger pump system according to a first embodiment; [Figure 2] FIG. 1 is a front view showing an example of the configuration of a plunger pump according to a first embodiment; [Figure 3] 3 is a view showing an example of the configuration of the plunger pump according to the first embodiment taken along line X3-X3 in FIG. 2, and showing an example of the configuration of the coil and its surroundings. [Figure 4] FIG. 1 is a cross-sectional view showing an example of a state in which the plunger is moved upward in the plunger pump according to the first embodiment; [Figure 5] FIG. 1 is a cross-sectional view illustrating an example of a plunger pump according to a first embodiment in a state where the plunger is moved downward; [Figure 6] FIG. 1 is a block diagram showing an example of the electrical configuration of an abnormality detection device in a plunger pump system according to a first embodiment. [Figure 7] FIG. 10 is a diagram showing an example of the plunger pump system according to the first embodiment, in which the maximum value of the waveform of the induced current generated in the coil is greater than the reference value. [Figure 8]FIG. 10 is a diagram showing an example of the plunger pump system according to the first embodiment when the minimum value of the waveform of the induced current generated in the coil is greater than a reference value. [Figure 9] FIG. 10 is a diagram showing an example of the plunger pump system according to the first embodiment, in which the maximum and minimum values ​​of the waveform of the induced current generated in the coil are each greater than a reference value. [Figure 10] FIG. 10 is a diagram showing an example of information displayed on an output unit by output processing in the plunger pump system according to the first embodiment; [Figure 11] 1 is a flowchart showing an example of detecting an abnormality in a plunger pump in the plunger pump system according to the first embodiment. [Figure 12] FIG. 10 is a diagram showing an example of a case where the period of the waveform of the induced current generated in the coil deviates from a reference value in the plunger pump system according to the first embodiment. [Figure 13] FIG. 10 is a diagram illustrating an example of a plunger pump system according to a second embodiment. [Figure 14] FIG. 10 is a block diagram showing an example of the electrical configuration of an abnormality detection device in a plunger pump system according to a second embodiment. [Figure 15] FIG. 10 is a block diagram showing an example of the electrical configuration of an information communication terminal in the plunger pump system according to the second embodiment. [Figure 16] FIG. 10 is a diagram showing an example of information displayed on an output unit of an information communication terminal by output processing in the plunger pump system according to the second embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0011] (First embodiment) First, a first embodiment of the present invention will be described with reference to FIGS. 1 includes a plunger pump 10 and a plunger pump abnormality detection device 20. In the following description, the plunger pump abnormality detection device 20 will be simply referred to as the abnormality detection device 20.

[0012] As shown in FIG. 1 , the plunger pump 10 can be applied to, for example, a coating apparatus 2. That is, the plunger pump 10 of this embodiment is a plunger pump for use in a coating apparatus. The coating apparatus 2 is equipped with a dolly 3. The dolly 3 is formed into a frame shape using, for example, steel pipes, etc., and the plunger pump 10 can be fixed to it. The dolly 3 has a plurality of wheels 3 a provided at a predetermined interval on its lower end, and a user can operate the dolly 3 to move the coating apparatus 2 within a work site such as a factory.

[0013] The carriage 3 also has a stopper 3b. The movement of the coating device 2 is restricted by a frictional force acting on the contact surface between the stopper 3b and the floor, allowing the coating device 2 to stand on its own. In this embodiment, the direction of gravity of the plunger pump 10 is defined as the up-down direction of the plunger pump 10. The side of the plunger pump 10 facing the carriage 3 is defined as the rear side of the plunger pump 10, and the side opposite the rear side, i.e., the side opposite the carriage 3 from the plunger pump 10, is defined as the front side of the plunger pump 10. The left-right direction of the plunger pump 10 when viewed from the front is defined as the left-right direction of the plunger pump 10. The coating device 2 may not include the carriage 3, and the plunger pump 10 may be attached to a steel frame, a wall, or the like.

[0014] Plunger pump 10 can be used in applications such as airless painting, which pressurizes and atomizes relatively highly viscous coating liquids, such as paints and cleaning fluids. As shown in FIG. 1 , plunger pump 10 includes motor unit 11, magnet 12, coil 13, pump unit 14, and connecting unit 15. Motor unit 11 functions as a drive source for plunger pump 10, i.e., generates driving force. Motor unit 11 is configured, for example, as an air motor. In this case, motor unit 11 is connected to a compressor (not shown) as an external drive source, and generates driving force using air compressed by the compressor. Motor unit 11 is not limited to an air motor, and may be configured as an electric motor, hydraulic motor, or the like.

[0015] As shown in Fig. 3, the motor unit 11 has a motor case 111, a piston 112 as a drive unit, and a shaft member 113. The motor case 111 is made of, for example, steel and formed into a cylindrical shape. The motor case 111 houses the piston 112 and a part of the shaft member 113 inside. The piston 112 is formed, for example, in a disk shape, and moves up and down within the motor case 111 as compressed air is alternately supplied to and exhausted from the spaces above and below the piston 112.

[0016] The shaft member 113 is provided below the piston 112 and is configured to be able to reciprocate linearly, i.e., vertically, integrally with the piston 112. The upper end of the shaft member 113 is fixed to the piston 112, for example, inside the motor case 111, and the lower end of the shaft member 113 protrudes downward from the motor case 111. The motor case 111 may have a sound-deadening body (not shown) that functions to muffle noise generated when the piston 112 and other components are driven. The motor case 111 may also be configured as a combination of two or more separate parts.

[0017] 2 and 3, the magnet 12 is, for example, a permanent magnet formed in a substantially rectangular shape. The north and south poles of the magnet 12 are arranged along the direction of movement of the shaft member 113. In this embodiment, the magnet 12 is configured so that the upper side of the magnet 12 is the north pole and the lower side of the magnet 12 is the south pole. The magnet 12 is arranged on the outer circumferential surface of the shaft member 113 near its lower end, for example.

[0018] In this case, as shown in FIG. 3 , a recess 113a is formed on the outer peripheral surface of the front side of the shaft member 113. The recess 113a is configured to be able to accommodate at least a portion of the magnet 12. The magnet 12 is fixed to the shaft member 113 while being accommodated in the recess 113a, for example, by adhesive or press-fitting. That is, the magnet 12 is provided on the outer peripheral surface of the front side of the shaft member 113. The magnet 12 is capable of moving integrally with the reciprocating movement of the shaft member 113. Note that the magnetic pole of the magnet 12 is not limited to a configuration in which the upper side of the magnet 12 is an N pole, and the upper side of the magnet 12 may be an S pole and the lower side of the magnet 12 an N pole. Furthermore, although one magnet 12 is provided on the outer peripheral surface of the shaft member 113, this is not limiting, and a configuration in which multiple magnets 12 are provided may also be used. When multiple magnets 12 are provided, the magnets 12 are arranged so that the magnetic poles of the magnets 12 all face the same direction.

[0019] The coil 13 is provided at the bottom of the motor case 111 and is formed in a cylindrical shape that surrounds the outside of the shaft member 113. As shown in FIGS. 2 and 3, the coil 13 has a base portion 131 and a body portion 132. The base portion 131 is formed, for example, in an annular shape. As shown in FIG. 3, the base portion 131 is detachably attached to the motor case 111 via a plurality of attachment members 133 formed, for example, by bolts. In this way, the coil 13 is detachably arranged in the motor case 111. In this case, the bottom surface of the motor case 111 and the base portion 131 are provided with attachment receiving portions (not shown) that are configured in a common shape at positions corresponding to the portions where the attachment members 133 are attached, and that are, for example, threaded with a female screw.

[0020] The body portion 132 is formed, for example, in a cylindrical shape, and one end thereof is connected to the base portion 131. The base portion 131 and the body portion 132 can be configured to be integrally formed from the same member. The body portion 132 also has a winding 134. The winding 134 is formed, for example, from an enameled wire, and as shown in FIG. 3, is provided between the inner and outer peripheries of the body portion 132 and extends spirally along the axial direction of the body portion 132. The inner diameters of the base portion 131 and the body portion 132 can be configured to be the same.

[0021] Body 132 is configured to allow magnet 12 to pass through as shaft member 113 moves back and forth in response to the driving force from piston 112. In this case, when shaft member 113 moves all the way up, magnet 12 passes through end surface 132a on the tip side of body 132 and is positioned inside body 132, as shown in Fig. 4. On the other hand, when shaft member 113 moves all the way down, magnet 12 is positioned outside body 132, as shown in Fig. 5. In other words, when shaft member 113 moves all the way down, magnet 12 is configured not to be positioned inside coil 13.

[0022] As the shaft member 113 moves, the relative positions of the magnet 12 and coil 13 change, causing a change in the magnetic field generated in the coil 13, and an induced current flows in the coil 13 due to electromagnetic induction. The magnitude of the induced current is proportional to the change over time in the magnetic flux linkage, i.e., the moving speed of the magnet 12. For this reason, for example, by observing the magnitude of the induced current flowing in the coil 13, it is possible to estimate the moving speed of the shaft member 113 to which the magnet 12 is attached. In other words, if the value of the induced current flowing in the coil 13 increases, it can be estimated that the moving speed of the shaft member 113 is increasing, and conversely, if the value of the induced current flowing in the coil 13 decreases, it can be estimated that the moving speed of the shaft member 113 is decreasing.

[0023] The pump unit 14 is provided below the motor unit 11. The pump unit 14 is supported integrally with the motor unit 11 via a connecting unit 15. As shown in FIG. 2 , the connecting unit 15 has a support member 151 and a support column 152. The support member 151 is provided separately below the motor unit 11. The support column 152 is, for example, made of steel and has a rod-like shape. It extends vertically between the motor unit 11 and the support member 151 and functions to integrally secure the motor unit 11 and the support member 151. In this case, one end of the support column 152 is fixed to the bottom surface of the motor unit 11, and the other end is fixed to the support member 151. In this case, when the motor unit 11 and the pump unit 14 are connected, one support column 152 is provided on each side symmetrically with respect to the central axis of the pump unit 14 in the left-right direction. The number of support columns 152 is not limited to this and may be set arbitrarily depending on the weight of the pump unit 14, etc.

[0024] The pump unit 14 has a function of sucking the application liquid stored in a tank (not shown) and discharging the sucked application liquid at a predetermined discharge pressure. Here, the predetermined discharge pressure means a high pressure of, for example, about 5 to 15 MPa. As shown in FIGS. 4 and 5, the pump unit 14 has a pump case 141, a plunger 142, and a seal member 143. The pump case 141 is made of, for example, steel and formed into a cylindrical shape. The pump case 141 forms the outer shell of the pump unit 14. The pump case 141 may be formed of a single member, or may be formed by combining two or more separate members.

[0025] The pump case 141 has a suction port 16, a suction valve 17, and a discharge port 18. The suction port 16 has a function of sucking the coating liquid stored in a tank (not shown) into the pump case 141, that is, sucking the coating liquid from the outside. As shown in FIG. 1, the suction port 16 is provided at the lower end of the pump case 141 and is connected to the tank via, for example, a flexible suction hose 91. As shown in FIGS. 4 and 5, the suction valve 17 is provided inside the pump case 141 above the suction port 16. The suction valve 17 has a check function that allows the coating liquid to pass from the outside of the pump case 141, that is, from the suction port 16 toward the inside of the pump case 141, but blocks the coating liquid from flowing from the inside of the pump case 141 to the outside of the pump case 141.

[0026] The suction valve 17 has a valve element 171, a valve seat 172, and a restriction portion 173. The valve element 171 is formed, for example, in a spherical shape. The valve seat 172 is formed, for example, in an annular shape, and is configured so that the valve element 171 can be placed thereon. The valve seat 172 also has a hole 174. The hole 174 communicates between the inside and outside of the pump case 141, and is closed when the valve element 171 is seated on the valve seat 172, and is opened when the valve element 171 is separated from the valve seat 172.

[0027] The restricting portion 173 is configured to allow the application liquid to pass through and to restrict the valve body 171 from moving in a direction away from the valve seat 172, i.e., upward, beyond a predetermined distance. In this case, the restricting portion 173 has a through-hole (not shown). The through-hole is configured so as not to be closed even when the valve body 171 comes into contact with the restricting portion 173, and is configured so as to allow the application liquid that has flowed into the pump case 141 from the suction port 16 to pass through.

[0028] In this configuration, when valve element 171 is seated on valve seat 172, hole 174 is blocked by valve element 171, so that suction valve 17 is in a closed state, i.e., a state in which application liquid is not sucked into pump case 141 through suction port 16. On the other hand, when valve element 171 moves in a direction away from valve seat 172, hole 174 that was blocked by valve element 171 is opened, so that suction valve 17 is in an open state, i.e., a state in which application liquid can be sucked into pump case 141 through suction port 16.

[0029] The discharge port 18 has the function of discharging the coating liquid supplied into the pump case 141 to the outside of the pump case 141. In other words, the discharge port 18 is used to discharge the coating liquid sucked into the pump case 141 from the suction port 16 to the outside. As shown in FIG. 1 , the discharge port 18 is provided on the side of the pump case 141 and is connected to a spray gun 93, for example, via a pressure-resistant paint hose 92. A user operates the spray gun 93 to apply the coating liquid supplied into the pump case 141 to an object to be coated. In addition, a filter unit 94 is installed between the discharge port 18 and the paint hose 92. The filter unit 94 collects impurities contained in the coating liquid that passes through the filter unit 94.

[0030] As shown in Figures 4 and 5, the plunger 142 has a lower portion housed within the pump case 141 and an upper portion protruding from the pump case 141, and is configured to be reciprocatable in a linear direction, i.e., up and down. In other words, the plunger 142 is movably housed in the pump section 14. The upper end portion of the plunger 142 is detachably connected to the lower end portion of the shaft member 113 via a connecting member 19. The connecting member 19 is configured, for example, by a long nut. In this case, the upper end portion of the plunger 142 and the lower end portion of the shaft member 113 are machined to have, for example, male threads.

[0031] In this way, the plunger 142 is driven by the motor unit 11, that is, moves up and down in conjunction with the reciprocating movement of the shaft member 113. During maintenance of the plunger pump 10, the connection between the connecting member 19 is released to release the fixation between the shaft member 113 and the plunger 142, and work such as replacing the plunger 142 can be performed.

[0032] The plunger 142 also has a communication port 31, a communication valve 32, and a seal member 33. The communication port 31 is provided at the lower end of the plunger 142. The communication port 31 is used to move the application liquid supplied into the pump case 141 into the plunger 142. That is, a portion of the application liquid supplied into the pump case 141 from the suction port 16 is introduced into the plunger 142 through the communication port 31 in the space within the pump case 141.

[0033] 4 and 5, the communication valve 32 is provided inside the plunger 142 above the communication port 31, i.e., on the downstream side. The communication valve 32 has a check function that allows the application liquid to pass from the upstream space S1 to the downstream space S2 inside the pump case 141, but blocks the application liquid from flowing from the downstream space S2 to the upstream space S1. In this case, the communication valve 32 is opened when the plunger 142 descends, and closed when the plunger 142 ascends.

[0034] The communication valve 32 has a valve element 321, a valve seat 322, and a restriction portion 323. The valve element 321 is configured, for example, to be spherical. The valve seat 322 is formed, for example, in an annular shape, and is configured so that the valve element 321 can be placed thereon. The valve seat 322 also has a hole 324. The hole 324 is closed when the valve element 321 is seated on the valve seat 322, and is opened when the valve element 321 is separated from the valve seat 322.

[0035] The restricting portion 323 is configured to allow the application liquid to pass through and to restrict the valve body 321 from moving in a direction away from the valve seat 322, i.e., upward. The restricting portion 323 also has a through-hole (not shown). The through-hole is configured so as not to be closed even when the valve body 321 comes into contact with the restricting portion 323, and is configured so that the application liquid that has flowed into the plunger 142 from the communication port 31 can move.

[0036] In this configuration, when the valve element 321 is seated on the valve seat 322, the hole 324 is closed by the valve element 321, so that the communication valve 32 is closed, i.e., the application liquid is not supplied to the space above the communication valve 32 in the plunger 142. On the other hand, when the valve element 321 moves in a direction away from the valve seat 322, the hole 624 that was closed by the valve element 321 is opened, so that the communication valve 32 is opened, i.e., the application liquid can be supplied to the space above the communication valve 32 in the plunger 142.

[0037] As shown in Fig. 4 and other figures, the seal member 33 is provided on the outer peripheral surface of the plunger 142. The seal member 33 is formed of a so-called lip packing, such as a V-packing or a U-packing, and is provided in an annular shape around the plunger 142. The seal member 33 is intended to fill the gap between the inner peripheral surface of the pump case 141 and the outer peripheral surface of the plunger 142. In other words, the seal member 33 prevents the application liquid, which has been supplied from the communication port 31 to the downstream space S2 inside the pump case 141, from moving toward the upstream space S1 inside the pump case 141.

[0038] As shown in Fig. 4 and other figures, the seal member 143 is provided between the inner circumferential surface of the pump case 141 and the outer circumferential surface of the plunger 142. The seal member 143 is formed of a so-called lip packing, such as a V-packing or a U-packing, and is provided in an annular shape around the plunger 142. The seal member 143 is provided downstream of the discharge port 18, in this case above the discharge port 18. The seal member 143 is intended to fill the gap between the inner circumferential surface of the pump case 141 and the outer circumferential surface of the plunger 142. In other words, the seal member 143 prevents the application liquid supplied from the suction port 16 into the pump case 141 from moving beyond the seal member 143 toward the external space.

[0039] In this configuration, when the plunger 142 moves up, as shown in Fig. 4, the external coating liquid is sucked into the upstream space S1 via the suction port 16 and the suction valve 17, and the coating liquid filled in the downstream space S2 is discharged from the discharge port 18. On the other hand, when the plunger 142 moves down, as shown in Fig. 5, the coating liquid in the upstream space S1 moves to the downstream space S2 via the communication valve 32, and a portion of the coating liquid that has moved to the downstream space S2 is discharged from the discharge port 18. In this way, the plunger pump 10 can repeatedly and continuously suck in and discharge the coating liquid by causing the plunger 142 to move back and forth in the up and down direction.

[0040] As shown in FIG. 1, the abnormality detection device 20 is connected to the plunger pump 10 and has a function of detecting an abnormal state of the plunger pump 10. The abnormality detection device 20 also has a function of presenting information obtained from the plunger pump 10 to a user. Therefore, the user can visualize and monitor the state of the plunger pump 10 using the abnormality detection device 20. The abnormality detection device 20 may be dedicated to the plunger pump system 1, or may be shared with other devices. The abnormality detection device 20 may be dedicated to detecting abnormalities in the plunger pump 10, or it may also serve as a control device that controls the operation of the plunger pump 10, for example, the discharge amount of the coating liquid.

[0041] 6, the abnormality detection device 20 has a detection unit 21, an input unit 22, an output unit 23, a storage unit 24, and a control unit 25. The detection unit 21 is configured, for example, by an integrated circuit, is connected to the coil 13 via a cable 211, and detects an induced current generated in the coil 13. The input unit 22 is configured, for example, by a touch sensor or a push button, and accepts user operations. The input unit 22 includes a reset button 221 for initializing presented information.

[0042] The output unit 23 can be configured with, for example, a liquid crystal display. The output unit 23 has a function of presenting information input by a user's operation on the input unit 22, information acquired from the plunger pump 10, etc. In this case, the input unit 22 and the output unit 23 can be configured with a touch panel display. The output unit 23 can also be configured with a speaker (not shown). The speaker has a function of emitting sound to the surroundings of the abnormality detection device 20. In this case, the output unit 23 has a function of presenting various information to the user by display, sound, etc.

[0043] The storage unit 24 can be configured, for example, with a rewritable hard disk drive, flash memory, etc. The storage unit 24 can store data regarding an abnormality that has occurred in the plunger pump 10 acquired by the control unit 25, such as information about the location of the abnormality and the date and time of the abnormality.

[0044] 6, the control unit 25 is mainly configured with a microcomputer having, for example, a CPU 251 and a storage area 252 such as a ROM, a RAM, and a rewritable flash memory. The plunger pump 10 can also be configured with a flow meter 26. The flow meter 26 is provided, for example, in the suction port 16, and measures the flow rate of the coating liquid flowing into the pump case 141. As shown in FIG. 6, the detection unit 21, the input unit 22, the output unit 23, the storage unit 24, and the flow meter 26 are each electrically connected to the control unit 25.

[0045] The memory area 252 stores a program for applying the abnormality detection device 20 to the plunger pump system 1. The control unit 25 executes the program in the CPU 251, thereby virtually realizing the acquisition processing unit 41, the setting processing unit 42, the determination processing unit 43, the output processing unit 44, and the storage processing unit 45 by software. That is, the acquisition processing unit 41, the setting processing unit 42, the determination processing unit 43, the output processing unit 44, and the storage processing unit 45 of the abnormality detection device 20 are realized by the CPU 251 executing the computer program stored in the memory area 252 and performing processing corresponding to the computer program, that is, by software. Note that the acquisition processing unit 41, the setting processing unit 42, the determination processing unit 43, the output processing unit 44, and the storage processing unit 45 may be realized by hardware, for example, as an integrated circuit integrated with the control unit 25, or by a combination of software and hardware.

[0046] The acquisition processing unit 41 can execute an acquisition process, which includes a process of acquiring the induced current generated in the coil 13 detected by the detection unit 21 and information detected by the flow meter 26.

[0047] The setting processing unit 42 can execute a setting process. The setting process includes a process of setting information based on the waveform of the induced current generated in the coil 13 as a reference value when the shaft member 113 is reciprocated in a normal state. The normal state means, for example, a state in which the plunger pump 10 operates normally and can discharge a predetermined amount of coating liquid. An example of the normal state is, for example, a state in which the plunger pump 10 is brand new or in a state immediately after maintenance.

[0048] 7 and the like, the waveform above the output value when the plunger pump 10 is not operating, i.e., zero, corresponds to the rising of the plunger 142, and the waveform below it corresponds to the falling of the plunger 142. However, the correspondence between the moving direction of the plunger 142 and the waveform may be reversed depending on the orientation of the magnetic poles of the magnet 12 and the moving direction relative to the coil 13.

[0049] 7 to 9, the reference value can be set by the maximum value Vsh and the minimum value Vsl of the waveform of the induced current generated in the coil 13. In this embodiment, the setting processing unit 42 executes the setting process during normal operation of the plunger pump 10 to set the reference value. Normal operation refers to operation when painting work is being performed by the painting device 2 equipped with the plunger pump 10.

[0050] The determination processing unit 43 can execute a determination process. The determination process includes a process of detecting an abnormality in the plunger pump by comparing a detection value based on information based on the waveform of the actual induced current generated in the coil 13 detected by the detection unit 21 with a reference value. In this case, the determination processing unit can determine that an abnormality has occurred in the plunger pump 10 when the maximum value Vh and the minimum value Vl of the waveform of the actual induced current generated in the coil 13 detected by the detection unit 21 deviate from the reference values.

[0051] Next, an example of the determination processing executed by the determination processing unit 43 will be described with reference to Fig. 7 to Fig. 9. The waveforms indicated by dashed lines in Fig. 7 to Fig. 9 indicate the reference value set by the setting processing executed by the setting processing unit 42, i.e., the waveform of the induced current generated in the coil 13 when the plunger pump 10 is in a normal state. The waveforms indicated by solid lines in Fig. 7 to Fig. 9 indicate examples of the waveform of the actual induced current generated in the coil 13 detected by the detection unit 21.

[0052] 7, for example, when the maximum value Vh of the waveform of the actual induced current generated in the coil 13 detected by the detection unit 21 is greater than the reference value Vsh, the rising speed of the plunger 142 integrally connected to the shaft member 113 is faster than normal. In this case, one example of a cause of the faster rising speed of the plunger 142 is thought to be a malfunction of the communication valve 32, such as wear of the valve disc 321, which causes paint to leak from the upstream space S1 to the downstream space S2 through a gap between the valve disc 321 and the valve seat 322.

[0053] 8, for example, when the minimum value Vl of the waveform of the actual induced current generated in the coil 13 detected by the detection unit 21 is larger than the reference value Vsl, the downward speed of the plunger 142 is faster than normal. In this case, one example of a cause of the increased downward speed of the plunger 142 is thought to be a malfunction of the suction valve 17, such as wear of the valve disc 171, which causes paint inside the pump case 141 to leak out through a gap between the valve disc 171 and the valve seat 172.

[0054] 9, for example, when the maximum value Vh and minimum value Vl of the waveform of the actual induced current generated in the coil 13 detected by the detection unit 21 are greater than the reference values ​​Vsh and Vsl, respectively, this is an event observed in a so-called blank shot state, in which no coating liquid is supplied into the pump case 141. In this case, for example, if the number of cycles per unit time of the plunger 142 exceeds a set reference value, it can be determined that an abnormality in the plunger pump 10, that is, a blank shot state, has occurred.

[0055] 7 to 9 show cases where the maximum and minimum values ​​of the waveform of the actual induced current generated in coil 13 detected by detection unit 21 are greater than the reference values, but even if the maximum and minimum values ​​are smaller than the reference values, determination processing unit 43 can detect an abnormality in plunger pump 10. In this case, it is assumed that the coating liquid is not being supplied appropriately due to wear of sealing members 33, 143, for example.

[0056] The output processing unit 44 can execute output processing. As shown in FIG. 10 , the output processing includes calculating the number of cycles of the reciprocating movement of the plunger 142 and the amount of coating liquid discharged from the discharge port 18 based on information detected by the detection unit 21 and the flow meter 26 acquired by the acquisition processing unit 41, and outputting the calculated information to the output unit 23 as information 81 indicating the operating status of the plunger pump 10. In this case, the output processing unit 44 can calculate the number of cycles of the plunger pump 142, by defining one cycle as a time when both the positive and negative values ​​of the dielectric current generated in the coil 13 detected by the detection unit 21 exceed set thresholds. The output processing unit 44 can also calculate the amount of coating liquid discharged from the discharge port 18 by, for example, integrating the detection signal of the flow meter 26.

[0057] The user can understand the operating status of the plunger pump 10 by checking the information 81 displayed on the output unit 23. The user can reset the information 81 displayed on the output unit 23 by performing an input operation on the reset button 221. The output process further includes a process of outputting to the output unit 23, when an abnormality in the plunger pump 10 is detected by the determination process, a notification that an abnormality has occurred. In this case, when an abnormality has occurred in the plunger pump 10, the output processing unit 44 displays, on the output unit 23, information 82 indicating that an abnormality has occurred, as shown in FIG. 10 .

[0058] In this embodiment, as described above, it is possible to detect an abnormality in the upward and downward movements of the plunger 142 and estimate the cause of the abnormality based on information about the waveform of the induced current generated in the coil 13. Therefore, the information 82 displayed on the output unit 23 by the output process can include information about the estimated location of the abnormality, specifically, information estimating the location of the abnormality, the details of the abnormality, and a method for preventing or resolving the abnormality. For example, if the minimum value Vl of the waveform of the induced current generated in the coil 13 is greater than the reference value Vsl, that is, if the downward speed of the plunger 142 is faster than normal, it is assumed that the suction valve 17 is worn out. Therefore, as shown in FIG. 10, the information 82 can include information estimating the location of the abnormality, the text "The suction valve is worn out" indicating the details of the abnormality, and the text "Perform maintenance" indicating a method for preventing or resolving the abnormality.

[0059] The memory processing unit 45 can execute a memory process. The memory process includes a process of storing the reference value set by executing the setting process. The information stored by the memory process can include the time when an abnormality in the plunger pump 10 detected by executing the determination process occurred, the maximum and minimum values ​​of the induced current generated in the coil 13 when the abnormality was detected, and the location of the abnormality estimated from the maximum and minimum values ​​of the induced current generated in the coil 13 when the abnormality was detected.

[0060] An example of control content in detecting an abnormality in plunger pump 10 will be described below with reference to Fig. 11. In the following description, it is assumed that all of the processing performed by processing units 41 to 45 is performed primarily by control unit 25.

[0061] First, when the user operates the spray gun 93 to start a painting operation (START), the control unit 25 determines in step S11 whether or not a condition for executing the setting process is met. The condition for executing the setting process can be determined, for example, by whether the plunger pump 10 is being operated for the first time or for the first time after maintenance. Then, if it is determined that the condition for executing the setting process is met, that is, whether the plunger pump 10 is being operated for the first time or for the first time after maintenance (YES in step S11), the control unit 25 proceeds to step S12.

[0062] In step S12, the control unit 25 acquires the induced current generated in the coil 13 detected by the detection unit 21 through processing by the acquisition processing unit 41. Next, in step S13, the control unit 25 sets a reference value based on the maximum value Vsh and minimum value Vsl of the waveform of the induced current generated in the coil 13 when the shaft member 113 is reciprocated through processing by the setting processing unit 42. Thereafter, in step S14, the control unit 25 stores the reference value set through processing by the storage processing unit 45 in the memory unit 24, and proceeds to step S15.

[0063] On the other hand, if the execution condition for the setting process is not met in step S11 (NO in step S11), the control device 25 shifts the process to step S15. In step S15, the control unit 25 acquires the induced current generated in the coil 13 detected by the detection unit 21 through processing by the acquisition processing unit 41. Next, in step S16, the control unit 25 determines whether the maximum value Vh and the minimum value Vl of the waveform of the actual induced current generated in the coil 13 detected by the detection unit 21 through processing by the determination processing unit 43 deviate from the reference values ​​Vsh and Vsl, respectively.

[0064] If the maximum value Vh and minimum value Vl of the waveform of the induced current generated in the coil 13 deviate from the respective reference values ​​Vsh and Vsl (YES in step S16), the control unit 25 proceeds to step S17. Thereafter, in step S17, the control unit 25 outputs information 82 indicating that an abnormality has occurred in the output unit 23 due to the processing of the output processing unit 44, and ends the abnormality detection (END).

[0065] According to the embodiment described above, plunger pump 10 includes drive unit 112, shaft member 113, magnet 12, and coil 13. Shaft member 113 receives a driving force from drive unit 112 and is capable of reciprocating in a linear direction. Magnet 12 is capable of moving integrally with the reciprocating movement of shaft member 113. Then, as shaft member 113 moves, the position of coil 13 relative to magnet 12 changes, generating an induced current.

[0066] This allows the induced current generated in coil 13 due to a change in the relative position between magnet 12 and coil 13 as shaft member 113 moves to be used to grasp the state of the stroke speed caused by the reciprocating movement of shaft member 113. This makes it possible to continuously know the state of the stroke speed of shaft member 113, and to detect problems in plunger pump 10 at an early stage before they lead to a breakdown. This makes it possible to realize failure prediction for plunger pump 10.

[0067] The coil 13 is formed in a cylindrical shape that surrounds the outside of the shaft member 113. The magnet 12 is The contact hole 132 is disposed along the direction of movement of the shaft member 113, and passes through only one end surface 132a of the coil 13 when the shaft member 113 moves back and forth.

[0068] If the magnet 12 is allowed to pass between both end faces of the coil 13 during one stroke of the reciprocating movement of the shaft member 113, one cycle of the induced current waveform is generated near each end of the coil 13. In this case, the period during which the induced current is zero during each cycle varies depending on the overall length of the coil 13, which can make it difficult to grasp the stroke speed of the shaft member 113. Therefore, by allowing only one end face 132a of the coil 13 to pass when the shaft member 113 reciprocates, one cycle of the induced current waveform can be displayed for one stroke of the reciprocating movement of the shaft member 113. This makes it possible to efficiently grasp the state of the stroke speed of the shaft member 113.

[0069] Furthermore, the abnormality detection device 20 of this embodiment is connected to the plunger pump 10 and detects an abnormal state of the plunger pump 10. The abnormality detection device 20 includes a detection unit 21, a setting processing unit 42, and a determination processing unit 43. The detection unit 21 detects an induced current generated in the coil 13. The setting processing unit 42 is capable of executing a setting process to set information based on the waveform of the induced current generated in the coil 13 as a reference value when the shaft member 113 is reciprocated in a normal state. The determination processing unit 43 is capable of executing a determination process to detect an abnormality in the plunger pump 10 by comparing a detection value based on information based on the waveform of the actual induced current generated in the coil 13 detected by the detection unit 21 with the reference value.

[0070] This makes it possible to predict failures in the plunger pump 10 with a simple configuration in which the detection value of the induced current generated in the coil 13 detected by the detection unit 21 is compared with a reference value based on information on the waveform of the induced current generated in the coil 13 under normal conditions. Furthermore, by using the induced current, there is no risk of the induced current becoming an ignition source even in a so-called explosion-proof area, which is an explosive environment where painting work is performed, for example, and therefore explosion-proof specifications can be met without taking any special safety measures.

[0071] The reference value is set based on the maximum value Vsh and minimum value Vsl of the waveform of the induced current generated in the coil 13. The determination process includes a process of determining that an abnormality has occurred in the plunger pump 10 when the maximum value Vh and minimum value Vl of the waveform of the actual induced current generated in the coil 13 detected by the detection unit 21 deviate from the reference values ​​Vsh and Vsl.

[0072] Here, for example, if an abnormality is detected when the timing of counting the number of cycles of the shaft member 113 is not constant over a predetermined period, the abnormality is detected based on intermittent information corresponding to the cycle results of the shaft member 113, making it difficult to predict a malfunction. Therefore, in this embodiment, an abnormality is detected based on the maximum value Vh and minimum value Vl of the waveform of the induced current generated in the coil 13. This makes it possible to continuously grasp the state of the stroke speed of the shaft member 113, thereby quickly determining whether there is an abnormality in the plunger pump 10. This makes it possible to predict a malfunction of the plunger pump 10.

[0073] Furthermore, the setting process is executed during normal operation of the plunger pump 10. Accordingly, by setting the reference value by the setting process during normal operation of the plunger pump 10, it is not necessary to set the reference value in advance before starting operation. This makes it possible to efficiently detect abnormalities in the plunger pump 10. Furthermore, since abnormality detection can be performed by reflecting the current operating status of the plunger pump 10, problems occurring in the plunger pump 10 can be detected more accurately.

[0074] In the setting process, the reference value can be set based on the period of the waveform of the induced current generated in the coil 13. In this case, in the example of Fig. 12, the setting process executed by the setting processing unit 42 includes a process of setting, as the reference value Vst, information based on the waveform of the induced current generated in the coil 13 when the shaft member 113 is reciprocated in a normal state. Then, the determination process executed by the determination processing unit 43 can determine that an abnormality has occurred in the plunger pump 10 when the period Vt of the waveform of the actual induced current generated in the coil 13 detected by the detection unit 21 deviates from the reference value Vst.

[0075] This makes it possible to accurately and quickly determine whether or not there is an abnormality in the plunger pump 10, compared to when, for example, the timing of counting the number of cycles of the plunger 142 is not constant for a predetermined period of time. This makes it possible to predict a failure of the plunger pump 10.

[0076] (Second embodiment) Next, a second embodiment will be described with reference to Figures 13 to 16. The configuration of this embodiment differs from the first embodiment in the contents of the components that make up plunger pump system 1. Specifically, in this second embodiment, plunger pump system 1 is configured such that abnormality detection device 20 and external devices 60 and 70 are connected to each other so as to be able to communicate with each other via, for example, access point 50 and telecommunications line 80 such as the Internet line or a LAN line.

[0077] In this embodiment, the anomaly detection device 20 has a communication unit 28, as shown in Fig. 14. The communication unit 28 has a function of communicating with external devices 60, 70, for example, via an access point 50 and an electric communication line 80. In this case, the communication unit 28 can be connected to the access point 50 using a wireless LAN or a wired LAN that complies with the Wi-Fi standard.

[0078] The external devices 60, 70 may be configured, for example, by an information communication terminal 60 such as a smartphone or a tablet terminal, and a server 70, respectively. In this case, it is assumed that the information communication terminal 60 is used by a user of the plunger pump 10. It is assumed that the server 70 is operated by a company. As shown in FIG. 15 , the information communication terminal 60 has a communication unit 61, an input unit 62, an output unit 63, a control unit 64, and an output processing unit 65.

[0079] The communication unit 61 has a function of communicating with the communication unit 28 of the abnormality detection device 20 via, for example, an electric communication line 80. The input unit 62 and the output unit 63 can be configured, for example, by a touch panel display. The output unit 63 can also be configured to include a speaker (not shown) built into the information communication terminal 60. The control unit 64 is mainly configured, for example, by a microcomputer having a CPU 641 and a storage area 642 such as a ROM, RAM, and rewritable flash memory, and controls the operation of the information communication terminal 60 and executes various processes. The communication unit 61, the input unit 62, and the output unit 63 are each electrically connected to the control unit 64.

[0080] The storage area 642 stores a computer program for connecting the information communication terminal 60 to the abnormality detection device 20 so as to be able to communicate with the information communication terminal 60 and for the information communication terminal 60 to function as a component of the plunger pump system 1. This computer program is stored as so-called application software, for example, in an external server 70. The control unit 64 downloads and installs the computer program from the external server 70, thereby virtually realizing the output processing unit 65 as software.

[0081] The output processing unit 65 has a function of receiving instructions from the anomaly detection device 20 and controlling the output of the output unit 63. For example, the anomaly detection device 20 can transmit an instruction to execute output processing using the information communication terminal 60 directly to the information communication terminal 60 via the communication unit 28 or indirectly via the server 70. Then, when the output processing unit 65 receives an instruction to execute output processing from the anomaly detection device 20, it causes the output unit 63 to output predetermined information based on the instruction. In this case, the predetermined information output by the output processing unit 65 can have the same configuration as the information output by the output processing unit 44.

[0082] Server 70 may be configured as, for example, an external server provided on the Internet, and may be called a database server, a web server, a cloud server, etc. Plunger pump system 1 may be configured so that communication between abnormality detection device 20 and information communication terminal 60 is performed directly between them, or may be configured so that communication is performed via server 70.

[0083] When communication between the abnormality detection device 20 and the information communication terminal 60 is performed via the server 70, the server 70 can store information about the abnormality detection device 20 and the information communication terminal 60 necessary for constructing the plunger pump system 1, such as the serial number and MAC address of the abnormality detection device 20, in association with an ID and password set by the user. The server 70 then mediates communication between the information communication terminal 60 into which the ID and password have been input and the abnormality detection device 20 associated with that ID. In this case, the server 70 functions as a so-called management server.

[0084] The server 70 can also store the above-mentioned application software. In this case, the server 70 functions as a so-called application storage server. Note that the management server and the application storage server may be different individual devices with different configurations, i.e., installed in different locations.

[0085] For example, when the output process is performed using the information communication terminal 60, the information communication terminal 60 outputs information 83 related to the output process to the output unit 63, as shown in Fig. 16. That is, when the output process is performed using the information communication terminal 60, the information communication terminal 60 displays information 83 indicating that an abnormality has occurred in the plunger pump 10 on the output unit 63. In this case, the information 83 displayed on the output unit 63 by the output process can include the text "The suction valve is worn out" and the text "Perform maintenance," as shown in Fig. 16.

[0086] The second embodiment described above also provides the same effects as the first embodiment. Furthermore, the occurrence of an abnormality in the plunger pump 10 can be confirmed by the external devices 60 and 70, thereby improving convenience.

[0087] The above describes one embodiment of the present invention, but this embodiment is presented as an example and is not limited to the embodiments described above and shown in the drawings, and can be modified as appropriate within the scope of the gist of the invention. [Explanation of symbols]

[0088] 1... plunger pump system, 10... plunger pump, 112... drive unit, 113... shaft member, 12... magnet, 13... coil, 132a... end surface, 20... plunger pump abnormality detection device, 21... detection unit, 23, 63... output unit, 42... setting processing unit, 43... judgment processing unit, 44, 65... output processing unit

Claims

1. A drive unit; a shaft member that is reciprocally movable in a linear direction by receiving a driving force from the driving unit; a magnet that can move integrally with the reciprocating movement of the shaft member; a coil in which an induced current is generated by a change in the relative position of the coil with respect to the magnet in response to the movement of the shaft member, The coil is formed in a cylindrical shape surrounding the outside of the shaft member, The magnet is arranged along the moving direction of the shaft member, and passes through only one end face of the coil when the shaft member moves back and forth. Plunger pump.

2. a shaft member that receives a driving force from the driving unit and is capable of reciprocating in a linear direction; a magnet that moves integrally with the reciprocating movement of the shaft member; and a coil that generates an induced current as the relative position of the magnet changes in response to the movement of the shaft member, the plunger pump abnormality detection device being connected to the plunger pump for detecting an abnormal state of the plunger pump, The coil is formed in a cylindrical shape surrounding the outside of the shaft member, the magnet is disposed along the moving direction of the shaft member, and passes through only one end face of the coil when the shaft member moves back and forth; The plunger pump abnormality detection device includes: a detection unit that detects an induced current generated in the coil; a setting processing unit that can execute a setting process to set information based on a waveform of an induced current generated in the coil when the shaft member is reciprocated in a normal state as a reference value; a determination processing unit that can execute a determination process to detect an abnormality in the plunger pump by comparing a detection value based on information based on a waveform of an actual induced current generated in the coil detected by the detection unit with the reference value; An abnormality detection device for a plunger pump comprising:

3. the reference value is set by a maximum value and a minimum value of a waveform of an induced current generated in the coil, the determination process includes a process of determining that an abnormality has occurred in the plunger pump when maximum and minimum values ​​of a waveform of the actual induced current generated in the coil detected by the detection unit deviate from the reference values.

3. The plunger pump abnormality detection device according to claim 2.

4. the reference value is set based on a period of a waveform of an induced current generated in the coil; the determination process includes a process of determining that an abnormality has occurred in the plunger pump when a period of a waveform of the actual induced current generated in the coil detected by the detection unit deviates from the reference value.

3. The plunger pump abnormality detection device according to claim 2.

5. The setting process is executed during normal operation of the plunger pump. The abnormality detection device for a plunger pump according to any one of claims 2 to 4.

6. a plunger pump including: a drive unit; a shaft member that receives a drive force from the drive unit and is capable of reciprocating in a linear direction; a magnet that moves integrally with the reciprocating movement of the shaft member; and a coil that generates an induced current as the relative position of the magnet changes in response to the movement of the shaft member; a detection unit connected to the plunger pump to detect an induced current generated in the coil; an output unit that outputs information acquired from the plunger pump to a user; a setting processing unit that can execute a setting process to set information based on a waveform of an induced current generated in the coil when the shaft member is reciprocated in a normal state as a reference value; a determination processing unit that can execute a determination process to detect an abnormality in the plunger pump by comparing a detection value based on information based on a waveform of an actual induced current generated in the coil detected by the detection unit with the reference value; an output processing unit that is capable of executing an output process to output information indicating that an abnormality has occurred to the output unit when an abnormality in the plunger pump is detected by the determination process, The coil is formed in a cylindrical shape surrounding the outside of the shaft member, The magnet is arranged along the moving direction of the shaft member, and passes through only one end face of the coil when the shaft member moves back and forth. Plunger pump system.

Images