Pump device

Abstract

The pump device includes a pump head having a suction port and a discharge port for the transfer fluid, a diaphragm attached to the pump head to form a pump chamber communicating the suction port and the discharge port, a reciprocating member connected to the diaphragm and provided so as to be movable in the reciprocating direction of the diaphragm, a drive mechanism capable of driving the reciprocating member in the reciprocating direction of the diaphragm, and a pump body including a control unit for controlling the drive mechanism. The pump device further includes a sensor unit disposed at a non-contact portion of the transfer fluid in the pump device for detecting strain occurring at the non-contact portion during operation of the pump device, and an estimation unit for estimating the actual flow rate of the transfer fluid or the pressure of the transfer fluid in the pump device based on the amount of strain at the non-contact portion detected by the sensor unit.

Description

Technical Field

[0001] The present invention relates to a pump device.

Background Art

[0002] Conventionally, a pump device having a structure in which a pump head is attached to a pump body housing a drive mechanism of a pump is known. For example, in a pump device of a type in which a reciprocating member such as a diaphragm reciprocates, the pressure in the pump chamber is acquired by a pressure sensor attached to the pump head or the like, and the flow rate of the transfer fluid is determined to judge the operating state. Thereby, for example, a failure due to a large accumulation of gas bubbles in the pump chamber is suppressed (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional pump device disclosed in Patent Document 1 above, a structure is adopted in which the pressure sensor is arranged at a position where it comes into contact with the transfer fluid. Therefore, for example, it is not suitable for transferring a transfer fluid having characteristics such that an expensive pressure sensor deteriorates or malfunctions. Therefore, in such a case, it is impossible to determine the flow rate of the transfer fluid and the like, and there is a problem that it is impossible to judge the operating state of the pump device based on this.

[0005] On the other hand, a flow meter is also provided in the piping of the pump device or the like to measure the flow rate of the transfer fluid. However, in this case, there is a problem that the cost of the flow meter increases and various piping conditions are restricted.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a pump device that can be configured at low cost and can easily estimate the flow rate, pressure, and operating state of a pump device without being affected by the characteristics of a transfer fluid and piping conditions.

Means for Solving the Problems

[0007] The pump device according to the present invention includes a pump head having a suction port and a discharge port for a transfer fluid, a diaphragm attached to the pump head and forming a pump chamber for communicating the suction port and the discharge port, a reciprocating member connected to the diaphragm and provided so as to be movable in the reciprocating direction of the diaphragm, a drive mechanism capable of driving the reciprocating member in the reciprocating direction of the diaphragm, and a control unit for controlling the drive mechanism, and a pump body including the above. This pump device is provided with a sensor unit that is disposed at a non-contact portion of the transfer fluid in the pump device and detects strain generated at the non-contact portion during operation of the pump device, and an estimation unit that estimates the actual flow rate of the transfer fluid or the pressure of the transfer fluid in the pump device based on the amount of strain at the non-contact portion detected by the sensor unit.

[0008] In one embodiment of the present invention, the control unit controls the operation of the drive mechanism so that the actual flow rate of the transfer fluid becomes a preset set flow rate based on the estimation result of the actual flow rate by the estimation unit.

[0009] In another embodiment of the present invention, it further includes a storage unit that stores information indicating the ratio of the actual flow rate to the potential difference of waveform data representing the amount of strain for each number of strokes of the reciprocating member created in advance. The estimation unit estimates the actual flow rate by referring to the information indicating the ratio of the actual flow rate in the storage unit from the potential difference of the waveform data representing the amount of strain.

[0010] In still another embodiment of the present invention, the control unit further includes a display unit that visibly displays the information on the estimated actual flow rate together with the set flow rate.

[0011] In still another embodiment of the present invention, when the output value of the waveform data representing the amount of strain after a lapse of a predetermined time from the start timing of the suction period of the pump device is greater than a predetermined threshold value, or when the output value of the waveform data representing the amount of strain after a lapse of a predetermined time from the start timing of the discharge period of the pump device is less than a predetermined threshold value, the estimation unit estimates that the operating state of the pump device is an abnormal operation.

[0012] In still another embodiment of the present invention, the sensor unit is disposed at the non-contact portion on the outer peripheral portion near the connecting portion of the reciprocating member with the diaphragm.

[0013] In still another embodiment of the present invention, a plurality of sensor units are arranged at the non-contact portions.

[0014] In still another embodiment of the present invention, the sensor unit is disposed at the non-contact portion in at least one of a reinforcing member attached to the front side of the pump head, a retainer member disposed on the back side of the diaphragm, a bracket member attached to the front side of the drive mechanism, an outer peripheral portion of the reciprocating member located on the rear side of the front surface of the bracket member, and an upper portion of the drive mechanism.

Advantages of the Invention

[0015] According to the present invention, it can be configured at low cost, and the flow rate, pressure, and operating state of the pump device can be easily estimated without being affected by the characteristics of the fluid to be transferred and the piping conditions.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0017] Hereinafter, with reference to the accompanying drawings, a pump device according to an embodiment of the present invention will be described in detail. However, the following embodiments do not limit the invention according to each claim, and not all combinations of the features described in the embodiments are essential for the solution means of the invention.

[0018] Further, in the following embodiments, the same or corresponding components are denoted by the same reference numerals, and redundant descriptions are omitted. Further, in the embodiments, when the arrangement, scale, dimensions, etc. of each component are exaggerated or minimized and shown in a state inconsistent with the actual one, and when the description of some components is omitted and shown.

[0019] [First Embodiment] [Configuration of Pump Device] FIG. 1 is a side cross-sectional view schematically showing a pump device according to a first embodiment of the present invention. FIG. 2 is a view taken along arrow A in FIG. 1. FIG. 3 is a block diagram schematically showing a circuit configuration of the pump device.

[0020] As shown in FIG. 1, a pump device 100 according to the first embodiment includes a pump body 20 having a drive mechanism 10 (drive unit) as a drive source and a control board 29, and a pump head 30 attached to the front side of the pump body 20. Note that the basic configuration of the pump device 100 in the present embodiment can be constituted by a so-called general pump device including an internal structure. Therefore, hereinafter, a detailed description of known configurations will be avoided and an outline will be described.

[0021] The pump device 100 also includes an adapter member 40 disposed between the pump head 30 and the pump body 20 in order to attach the pump head 30 to the pump body 20. The pump device 100 includes a diaphragm 50 that is sandwiched and attached by the adapter member 40 and is connected to a shaft member 11, which is a reciprocating member of the drive mechanism 10, via the adapter member 40.

[0022] Furthermore, the pump device 100 has a strain gauge 16 as a sensor unit disposed at a non-contact portion of the fluid to be transferred in the pump device 100. Hereinafter, the direction from the pump body 20 toward the pump head 30 is defined as the front, and the direction opposite to this is defined as the rear. Also, as shown by the arrows in FIG. 1, the operating directions of the diaphragm 50 and the shaft member 11 in the front and rear directions are defined as the reciprocating direction RD.

[0023] [Configuration of Drive Mechanism] The drive mechanism 10 includes, for example, a motor 12, an eccentric cam mechanism 13, and a shaft member 11. The motor 12 rotationally drives a rotating shaft 13a of the eccentric cam mechanism 13 via a gear mechanism 12a. The eccentric cam mechanism 13 converts the rotational motion of the rotating shaft 13a into a reciprocating motion of the shaft member 11 by means of an eccentric cam portion 13b. The shaft member 11 is driven in the forward and backward reciprocating directions RD by the reciprocating motion converted by the eccentric cam mechanism 13.

[0024] The shaft member 11 is made of, for example, a rod-shaped metal member or resin member. The shaft member 11 has, for example, a first member 11a disposed on the front side so as to be connected to a diaphragm 50, and a second member 11b connected and disposed on the rear side of the first member 11a and connected to the eccentric cam portion 13b of the eccentric cam mechanism 13.

[0025] The shaft member 11 is pushed forward by the eccentric cam portion 13b. At the same time, the front flange portion 11c of the second member 11b of the shaft member 11 is pressed forward by the repulsive force of the spring member 14. Thereby, the shaft member 11 moves toward the front side of the pump body 20 and displaces the diaphragm 50 in the forward direction. Further, the shaft member 11 moves toward the rear side of the pump body 20 when the front flange portion 11c of the second member 11b is pulled back toward the rear side by the eccentric cam portion 13b more strongly than the repulsive force of the spring member 14. Thereby, the shaft member 11 displaces the diaphragm 50 in the backward direction.

[0026] In this way, the shaft member 11 is pushed and pulled by the eccentric cam portion 13b in the drive mechanism 10 and repeats the forward and backward operations as described above, thereby reciprocating in the reciprocating direction RD. Note that a bracket portion 15, which is a bracket member facing a front opening 20a of the pump body 20, is provided on the front side (front surface) of the drive mechanism 10 to attach an adapter member 40 described later.

[0027] Further, the drive mechanism 10 is not limited to the configuration including the motor 12 and the eccentric cam mechanism 13 described above, as long as the shaft member 11 can be driven at least in the direction in which the diaphragm 50 moves forward or backward as described above. The drive mechanism 10 may adopt a configuration such as an actuator that directly moves the shaft member 11 by, for example, electromagnetic force or the like.

[0028] [Configuration of Pump Body] The housing portion constituting the pump body 20 is made of, for example, a resin member. That is, the pump body 20 includes a front housing 26, a rear housing 27 connected thereto, and a pump base 20b. The front housing 26 has a front opening 20a provided on the front side and a housing space 21 connected from the front opening 20a provided above the pump base 20b. The rear housing 27 has a housing space 25 capable of housing the control board 29.

[0029] The housing space 21 in the front housing 26 of the pump body 20 is formed, for example, in a cylindrical shape. A part (for example, the lower side) of the housing space 21 of the pump body 20 is configured to be connected to the inside of the pump base 20b. The housing space 25 in the rear housing 27 of the pump body 20 is formed in a shape similar to or a rounded rectangular shape similar to the housing space 21 while being isolated from the housing space 21 in the reciprocating motion direction RD. A part (for example, the lower side) of the housing space 25 of the pump body 20 is configured to be connected to the inside of the pump base 20b.

[0030] In the housing space 21 of the front housing 26, mainly together with the drive mechanism 10, for example, a cable 19 as wiring is housed inside, a wiring tube 19a wound around the drive mechanism 10, and the bracket portion 15 described above are housed. The front housing 26 has a rear wall 22 provided on the rear side. The rear housing 27 is attached to the back surface (rear side surface) 22a of the rear wall 22 of the front housing 26 by screwing using mounting screws 27a.

[0031] The control board 29 is directly attached to the rear housing 27 by screwing using the mounting screws 27b. The cable 19 of the wiring tube 19a is connected to the control board 29. The control board 29 controls the drive mechanism 10 to control the overall operation of the pump device 100.

[0032] Note that an operation unit 28 for performing operation inputs such as setting operations of the pump device 100 by an operator, etc. is provided on the rear side of the pump body 20. The operation unit 28 includes a display unit 28a that visibly displays various types of information regarding the pump device 100.

[0033] [Arrangement of the sensor unit] The strain gauge 16, which is a sensor unit, is arranged, as a non-contact part with the transfer fluid, in the outer peripheral part near the connection part with the diaphragm 50 in the first member 11a of the shaft member 11, for example. The strain gauge 16 detects the strain generated in the outer peripheral part of the first member 11a during the operation of the pump device 100.

[0034] As shown in FIG. 2, the strain gauge 16 is attached to the outer peripheral part of the first member 11a via an adhesive or the like. However, the arrangement mode of the strain gauge 16 is not limited to this. The strain gauge 16 may be arranged alone on the outer peripheral part of the first member 11a as shown in the figure, but in this embodiment, although not shown in the figure, a plurality (for example, two) are arranged on the outer peripheral part of the first member 11a.

[0035] The strain gauge 16 is connected such that the lead wire 16a extends in a direction intersecting the reciprocating direction RD. The lead wire 16a extending from the strain gauge 16 is provided with protection measures such as, for example, a silicone coating. A connector 16b is connected to the end of the lead wire 16a. The connector 16b is connected to a relay connector 16c provided on a part of the bracket portion 15. The relay connector 16c is connected to, for example, a sensor substrate 29a disposed above the drive mechanism 10 via a cable 19b and a connector 16d. This sensor substrate 29a is connected to the cable 19 via a connector 16e. Thereby, the strain gauge 16 is electrically connected to the control board 29 via the lead wire 16a, the connector 16b, the relay connector 16c, the cable 19b, the connector 16d, the sensor substrate 29a, the connector 16e, and the cable 19.

[0036] [Configuration of Pump Head] The pump head 30 is made of, for example, a resin member or a metal member such as stainless steel. The pump head 30 has a pump chamber 31 formed in the center. The pump chamber 31 is formed together with a diaphragm 50 attached to the pump head 30, and its volume changes as the diaphragm 50 is displaced. In the pump device 100 of the present embodiment, on the front side of the pump head 30, for example, a reinforcing plate 30a which is a reinforcing member for reinforcing the mechanical strength of the pump head 30, and a cover member 30b for protecting the reinforcing plate 30a are attached.

[0037] The pump head 30 is attached to the front opening 20a side of the front housing 26 via, for example, an adapter member 40 attached to the bracket portion 15 of the drive mechanism 10. The pump head 30 has a suction port 32 and a discharge port 33 for the transfer fluid communicating with the pump chamber 31. The suction port 32 communicates, for example, below the pump chamber 31. The discharge port 33 communicates, for example, above the pump chamber 31.

[0038] The pump head 30 is formed with a first connection port 34 on the suction side of the fluid to be transferred, which is disposed below the suction port 32. Further, the pump head 30 is formed with a second connection port 35 on the discharge side of the fluid to be transferred, which is disposed above the discharge port 33. These first connection port 34 and second connection port 35 communicate with the pump chamber 31 via the suction port 32 and the discharge port 33, respectively.

[0039] A cylindrical suction-side adapter 37 is connected to the first connection port 34 by a connection nut 37a with a suction valve 36a incorporated therein. A cylindrical discharge-side adapter 38 is connected to the second connection port 35 by a connection nut 37b with a discharge valve 36b incorporated therein.

[0040] The suction-side adapter 37 is connected to a suction-side pipe (not shown) and connects the suction port 32 of the pump head 30 to a suction-side flow path 39a via the suction valve 36a. The discharge-side adapter 38 is connected to a discharge-side pipe (not shown) and connects the discharge port 33 of the pump head 30 to a discharge-side flow path 39b via the discharge valve 36b.

[0041] [Configuration of Adapter Member] The adapter member 40 is made of, for example, a resin member. The adapter member 40 is disposed between the pump head 30 and the pump body 20 (front opening 20a of the front housing 26). Thereby, the adapter member 40 closes the front opening 20a to close the accommodation space 21. The adapter member 40 has, for example, a plurality of mounting holes (not shown) arranged at a predetermined pitch and a plurality of insertion holes (not shown) arranged at a predetermined pitch different from these plurality of mounting holes.

[0042] The adapter member 40 is fastened to the bracket portion 15 by fastening means such as bolts (not shown in the figure) inserted into the mounting holes. Thereby, the adapter member 40 is attached to the pump body 20 so as to close the front opening 20a of the front housing 26. The pump head 30 is fastened to, for example, a bolt 42a passing through the insertion holes of the reinforcing plate 30a and the adapter member 40 and a bracket portion 15 disposed behind the adapter member 40, whereby the adapter member 40 is attached to the front side of the pump body 20 in a liquid-tight manner via the adapter member 40.

[0043] The adapter member 40 has, for example, an annular convex portion 43 that sandwiches a fixing portion 51 located on the outer peripheral portion of the diaphragm 50 together with the pump head 30, and a wall portion 44 continuous with the inner peripheral wall surface 43a of the annular convex portion 43. A circular central hole portion 46 is formed at the center of the wall portion 44 of the adapter member 40.

[0044] A gasket member 60 is attached to the back surface (the surface on the side of the front housing 26) of the wall portion 44 of the adapter member 40 in a state of being sandwiched between the bracket portion 15 and the adapter member 40. The gasket member 60 is made of, for example, rubber. The gasket member 60 has a disk portion 61 that contacts the back surface of the wall portion 44, and a central convex portion 62 provided at the center of the disk portion 61 and having a concavo-convex shape (bellows shape in a direction intersecting the reciprocating direction RD) in the reciprocating direction RD.

[0045] The central convex portion 62 of the gasket member 60 is inserted into the central hole portion 46 of the wall portion 44 of the adapter member 40 in a liquid-tight manner. Further, the first member 11a of the shaft member 11 is inserted into the central hole 63 of the central convex portion 62 in a liquid-tight manner. Therefore, the outer peripheral portion of the first member 11a of the shaft member 11 where the strain gauge 16 is disposed is disposed so as to be located behind the central hole 63 of the central convex portion 62 of the gasket member 60. Thereby, the outer peripheral portion of the first member 11a is not in contact with the transfer fluid flowing through the suction port 32, the pump chamber 31, and the discharge port 33, and is disposed in a non-contact state.

[0046] [Configuration of Diaphragm] The diaphragm 50 is connected to the first member 11a of the shaft member 11 inserted through the central hole 63 of the central convex portion 62 of the gasket member 60 via an insert bolt 52. The diaphragm 50 is an elastic member in which the insert bolt 52 connected to the first member 11a is integrally formed inside a resin such as ethylene propylene rubber (EPDM) and polytetrafluoroethylene resin (PTFE).

[0047] The diaphragm 50 is driven by the drive mechanism 10 housed in the front housing 26 of the pump body 20 to be displaced in the reciprocating direction RD so as to change the volume of the pump chamber 31 of the pump head 30. As described above, the fixing portion 51 of the diaphragm 50 is sandwiched between the pump head 30 and the annular convex portion 43 of the adapter member 40. At the same time, the diaphragm 50 is liquid-tightly attached in a state where the front side of the central portion 53 faces the pump chamber 31. A retainer member 54 for maintaining the shape and position of the diaphragm 50, for example, is disposed between the diaphragm 50 and the tip of the first member 11a of the shaft member 11.

[0048] In the pump device 100 configured as described above, for example, when it becomes necessary to replace the strain gauge 16, the pump head 30, the diaphragm 50, and the adapter member 40 are removed from the pump body 20. Then, the connector 16b is detached from the relay connector 16c, and the strain gauge 16 may be replaced together with the first member 11a of the shaft member 11. Therefore, a structure is realized in which the replacement work of the strain gauge 16 and the maintenance work on the pump head 30 side are easy.

[0049] [Circuit Configuration of Pump Device] As shown in FIG. 3, the circuit configuration of the pump device includes a plurality of strain gauges 16 (resistors R1, R2), a sensor substrate 29a, and a control substrate 29. The sensor substrate 29a includes resistors R3 and R4 that form a bridge circuit 71 together with the plurality of strain gauges 16 (resistors R1, R2), and a differential amplifier circuit 72 that includes an operational amplifier 72a and a plurality of resistors R5, R6, R7, and R8 connected thereto. The control substrate 29 includes a control unit 73, an estimation unit 74, and a storage unit 75.

[0050] Each of the circuits 71 and 72 on the sensor substrate 29a is appropriately circuit-designed according to various data and conditions such as the main specifications of the pump device 100. Each of the units 73 to 75 on the control substrate 29 is appropriately configured by a combination of known hardware such as a CPU, a RAM, and a ROM.

[0051] The bridge circuit 71 includes a strain gauge 16 as resistor R1 and a strain gauge 16 as resistor R2 arranged on adjacent sides of the bridge, and resistors R3 and R4 as two fixed resistors. The bridge circuit 71 is configured to be able to reduce the apparent strain due to temperature.

[0052] The differential amplifier circuit 72 appropriately adjusts the values of the four resistors R5 to R8 connected to the operational amplifier 72a. Thereby, the differential amplifier circuit 72 is configured to amplify the output (detection signal of the strain amount) from the bridge circuit 71 to a predetermined value, remove noise, and perform temperature compensation.

[0053] Therefore, the detection signal of the strain gauge 16 output from the bridge circuit 71 during the operation of the pump device 100 is temperature-compensated and then amplified and noise-removed in the differential amplifier circuit 72. Then, the detection signal can be input to the estimation unit 74 as waveform data representing the strain amount on the outer peripheral portion of the first member 11a of the shaft member 11.

[0054] The estimation unit 74 estimates the flow rate or pressure of the fluid being transferred in the pump device 100 based on the input waveform data. That is, in the pump device 100, the flow rate and pressure of the fluid being transferred vary depending on the load. The pressure change inside the pump head 30 (for example, inside the pump chamber 31) that occurs during the operation of the pump device 100 is applied as a load change to the shaft member 11 via the diaphragm 50. As a result, a strain proportional to the load (load) is generated.

[0055] By detecting this generated strain with the strain gauge 16, the estimation unit 74 estimates the flow rate or pressure of the fluid being transferred in the pump device 100 based on the waveform data representing the amount of strain output through the bridge circuit 71 and the differential amplifier circuit 72.

[0056] On the other hand, based on the estimation result of the flow rate by the estimation unit 74, the control unit 73 controls the operation of the drive mechanism 10 so that the actual flow rate (actual flow) of the fluid being transferred becomes, for example, a preset flow rate. The storage unit 75 stores information (actual flow rate ratio data) regarding the flow rate reduction rate or actual flow rate ratio with respect to the potential difference of the waveform data representing the amount of strain for each number of strokes (spm: strokes per minute) of the shaft member 11 created, for example, by performing measurement in advance. The estimation unit 74 estimates the actual flow rate of the pump device 100 by referring to the actual flow rate ratio data stored in the storage unit 75.

[0057] Also, when gas is inhaled into the pump chamber 31 during gas inhalation, the rise of the waveform data representing the amount of strain is delayed due to the compression of the gas. From this, the estimation unit 74 grasps the gas inhalation state by setting a threshold value for the output value after a certain time (after a predetermined time) has elapsed since the rise of the waveform data.

[0058] In this way, based on the estimated actual flow rate, the estimation unit 74 can further estimate the operating state of the pump device 100, for example, to what extent the actual flow rate is operating with respect to the set flow rate, or whether the operating state is an abnormal operation. Then, based on the estimation result of the actual flow rate by the estimation unit 74, the control unit 73 performs a flow rate correction calculation so that the actual flow rate of the transferred fluid becomes the set flow rate, for example, by using the above actual flow rate ratio data. Then, the control unit 73 can operate the drive mechanism 10 to correct the flow rate. Note that the display unit 28a in the operation unit 28 can display the notification information regarding the operating state of the pump device 100 estimated by the estimation unit 74 so that the operator can visually recognize it.

[0059] FIG. 4 and FIG. 5 are graphs illustrating the estimated flow rate and the actually measured flow rate of the pump device 100. In FIG. 4, the set flow rate is 60 [L / H], and in FIG. 5, the set flow rate is 1.0 [L / H]. The vertical axis represents the flow rate [L / H], and the horizontal axis represents the pressure [MPa].

[0060] As shown in the graph 77a of FIG. 4 and the graph 77b of FIG. 5, regardless of whether the set flow rate is 60 [L / H] or 1.0 [L / H], when the pump pressure increases in either case, the flow rate tends to decrease. The approximate curve 77c of the estimated flow rate shown by the broken line in the figure is represented so as to draw an approximately the same curve shape as the approximate curve 77d of the actually measured flow rate shown by the solid line in the figure. As a result of comparing the thus represented estimated flow rate and the actually measured flow rate by calculation, the error of the estimated flow rate with respect to the actually measured flow rate was within ±2.08 [%RS] of the read scale accuracy. Therefore, it was found that the flow rate estimation by the estimation unit 74 can be performed with high accuracy. Here, as described above, the pump pressure has a large correlation with the amount of strain.

[0061] FIG. 6 is a graph illustrating the suction period and the discharge period of the pump device 100 and the waveform data of the amount of strain. FIG. 7 is a diagram showing an example of data stored in the storage unit 75 of the pump device 100, and represents an example of the actual flow rate ratio data indicating the flow rate reduction rate measured and created in advance in the pump device 100 connected under a predetermined piping condition.

[0062] As shown in FIG. 6, the high-level square wave U represents the suction period during which the pump device 100 sucks in the transfer fluid. Also, the low-level square wave D represents the discharge period during which the pump device 100 discharges the transfer fluid. This is obtained, for example, from a sensor cam signal (not shown). On the other hand, the waveform data W shows the output waveform of the differential amplifier circuit 72. The waveform data W represents, for example, the amount of strain detected by the strain gauge 16 for the stress change of the shaft member 11 of the pump device 100. Therefore, the higher the level of the waveform data W, the more the shaft member 11 is loaded (the higher the load on the pump device 100). This waveform data W has the characteristic that its shape and level size change and appear depending on the value of the pressure of the transfer fluid.

[0063] According to FIG. 6, during the suction period of the transfer fluid represented by the square wave U, the shaft member 11 is pulled back rearward and the load on the shaft member 11 decreases, so it can be seen that the waveform data W drops sharply and the level decreases. On the other hand, during the discharge period of the transfer fluid represented by the square wave D, the shaft member 11 is pushed forward and the load on the shaft member 11 increases with the passage of time, so it can be seen that the waveform data W rises more gently and the level becomes higher than when it drops as described above.

[0064] Then, for example, the potential difference PD of the drive mechanism 10 represented by the level position D1 of the waveform data W at the end of the square wave D in a certain period and the level position D2 of the waveform data W at the start of the square wave D in the next period is estimated and obtained from the waveform data W. Thereby, it becomes possible to recognize the pressure of the transfer fluid as the potential difference PD. In this embodiment, the "potential difference [V] of the waveform data representing the amount of strain", which is the input variable of the estimation unit 74, is set as the average value of the potential differences PD of 3 samples in order to eliminate the influence of noise. However, the number of samples for obtaining the average value may be more or less.

[0065] In the actual flow rate ratio data 78 showing the flow rate reduction rate of FIG. 7, the elements in the rows represent a plurality of potential differences [V] calculated from the potential differences PD of 3 samples under, for example, one operating condition (number of strokes). Further, in the actual flow rate ratio data 78, the elements in the columns represent a plurality of number of strokes [spm] set at, for example, 9 resolutions, and the numerical values of the corresponding flow rate reduction rates are associated therewith.

[0066] Note that the number of strokes [spm] corresponds to the set flow rate [L / H]. In this example, the number of strokes [spm] of 0.9 to 3.6, 3.6 to 9.0, 9.0 to 18.0, 18.0 to 36.0, 36.0 to 72.0, 72.0 to 108, 108 to 144, 144 to 180, 180 to correspond to the set flow rates [L / H] of 0.3 to 1.2, 1.2 to 3.0, 3.0 to 6.0, 6.0 to 12.0, 12.0 to 24.0, 24.0 to 36.0, 36.0 to 48.0, 48.0 to 60.0, 60.0 to, respectively.

[0067] As shown in FIG. 7, according to the actual flow rate ratio data 78 showing the flow rate reduction rate, for example, when the potential difference [V] is greater than 0.10 and less than 0.35, the flow rate reduction rate is 0.00 (%) for any number of strokes [spm] from 0.9 to 180, so it can be estimated that the actual flow rate remains the set flow rate.

[0068] On the other hand, as the potential difference [V] gradually increases to 0.35 to 0.60, 0.60 to 0.85,..., greater than 2.70, the flow rate reduction rate at each number of strokes [spm] decreases. The largest flow rate reduction rate is in the range greater than the maximum number of strokes [spm] of 180, and the flow rate reduction rate in that case is 23.68%.

[0069] Then, the estimation unit 74 inputs the potential difference [V] and the flow rate set value [L / H] (set number of strokes [spm]) as input variables, and estimates the actual flow rate based on the table as shown in FIG. 7 stored in the storage unit 75.

[0070] FIG. 8 is a diagram showing an example of display on the display unit of the pump device. As shown in FIG. 8, on the display unit 28a included in the operation unit 28, for example, a first flow rate display area 28b for displaying the flow rate estimated by the estimation unit 74 (and the actual flow rate calculated by calculation) as described above, and a second flow rate display area 28c for displaying the set flow rate set in advance by an operator or the like are provided. In the display unit 28a, by displaying the thus estimated flow rate and the set flow rate in parallel so as to be easily visible, the operator can easily grasp the operating state of the pump device 100.

[0071] Note that the estimation unit 74 can perform arithmetic processing such that, for example, the number of strokes [spm] is used as a magnification obtained by adding 100 to the flow rate reduction rate (flow rate reduction rate + 100 (%)), correct the flow rate corresponding to the reduction from the set flow rate, and control the operation of the drive mechanism 10 by the control unit 73 so as to reach the set flow rate again.

[0072] Further, as described above, the estimation unit 74 detects the pressure of the transferred fluid from the waveform data representing the amount of strain, and for example, when the output value of the waveform data representing the amount of strain after a certain time has elapsed from the start timing of the suction period of the pump device 100 is larger than a predetermined threshold value, or when the output value of the waveform data representing the amount of strain after a certain time has elapsed from the start timing of the discharge period is smaller than a predetermined threshold value, it is estimated that the operating state of the pump device 100 is abnormal. Further, the estimation unit 74 may pay attention to, for example, whether the waveform shape of the waveform data from the rising portion to the peak portion is delayed compared to the normal operation. If the waveform shape represents an operating state such as a special shape that is significantly delayed from the start timing of the discharge period indicated by the square wave D compared to the normal operation, it may be similarly estimated that a gas inhalation state has occurred and the operating state of the pump device 100 is an abnormal operation. In these cases, it is also possible to display notification information for notifying the fact on the display unit 28a.

[0073] Thus, the pump device 100 according to the present embodiment can estimate the flow rate and pressure of the fluid to be transferred in the pump device 100 based on the amount of strain of the shaft member 11 detected by the strain gauge 16. As a result, it can be configured at low cost, and the flow rate and operating state can be easily estimated without being affected by the characteristics of the fluid to be transferred and the piping conditions, and it is also possible to easily correct the flow rate and estimate abnormal operation.

[0074] [Second Embodiment] FIG. 9 is a cross-sectional view schematically showing the arrangement position of the sensor unit in the pump device according to the second embodiment of the present invention. Hereinafter, descriptions overlapping with those already described will be omitted.

[0075] As shown in FIG. 9, the pump device 100A according to the second embodiment is different from the first embodiment in that a strain gauge 16, which is a sensor unit, is arranged on the front surface 30c side of a reinforcing plate 30a attached to the front side of a pump head 30, which is a non-contact part of the fluid to be transferred, for example. Even with this configuration, since the load of the pump device 100A can be detected by the strain gauge 16 as the amount of strain, it is possible to achieve the same effects as those of the first embodiment.

[0076] [Third Embodiment] FIG. 10 is a cross-sectional view schematically showing the arrangement position of the sensor unit in the pump device according to the third embodiment of the present invention.

[0077] As shown in FIG. 10, the pump device 100B according to the third embodiment is different from the first and second embodiments in that a strain gauge 16, which is a sensor unit, is arranged on the back surface (rear surface) 54a side of a retainer member 54 arranged on the back side (rear side) of a diaphragm 50, which is a non-contact part of the fluid to be transferred, for example. Even with this configuration, since the load of the pump device 100B can be detected by the strain gauge 16 as the amount of strain, it is possible to achieve the same effects as those of the first and second embodiments.

[0078] [Fourth Embodiment] FIG. 11 is a cross-sectional view schematically showing the arrangement position of the sensor unit in the pump device according to the fourth embodiment of the present invention.

[0079] As shown in FIG. 11, the pump device 100C according to the fourth embodiment is different from the first to third embodiments in that a strain gauge 16, which is a sensor unit, is arranged on the back surface (rear surface) 15a side of a bracket portion 15 attached to the front side of a drive mechanism 10, which is, for example, a non-contact portion of the fluid to be transferred. Even with such a configuration, since the load of the pump device 100C can be detected by the strain gauge 16 as a strain amount, it is possible to achieve the same operational effects as those of the first to third embodiments.

[0080] [Fifth Embodiment] FIG. 12 is a cross-sectional view schematically showing the arrangement position of the sensor unit in the pump device according to the fifth embodiment of the present invention.

[0081] As shown in FIG. 12, the pump device 100D according to the fifth embodiment is different from the first to fourth embodiments in that a strain gauge 16, which is a sensor unit, is arranged on the outer peripheral portion of a second member 11b of a shaft member 11 located on the rear side of the front surface of a bracket portion 15, which is, for example, a non-contact portion of the fluid to be transferred. Even with such a configuration, since the load of the pump device 100D can be detected by the strain gauge 16 as a strain amount, it is possible to achieve the same operational effects as those of the first to fourth embodiments.

[0082] [Sixth Embodiment] FIG. 13 is a cross-sectional view schematically showing the arrangement position of the sensor unit in the pump device according to the sixth embodiment of the present invention.

[0083] As shown in Fig. 13, the pump device 100E according to the sixth embodiment is different from the first to fifth embodiments in that a strain gauge 16, which is a sensor unit, is disposed, for example, on the upper portion of the drive mechanism 10 (e.g., the upper surface 13d of the bearing portion 13c of the eccentric cam mechanism 13), which is a non-contact portion of the fluid to be transferred. Even with such a configuration, since the load of the pump device 100E can be detected by the strain gauge 16 as a strain amount, it is possible to achieve the same operational effects as those of the first to fifth embodiments.

[0084] As described above, although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalent scope thereof.

[0085] For example, in the above-described first embodiment, the strain gauge 16 is disposed on the outer peripheral portion of the first member 11a of the shaft member 11, and in the second to sixth embodiments, the strain gauge 16 is disposed at a non-contact portion of the fluid to be transferred, which is different from that of the first embodiment. In addition, the strain gauge 16 may be disposed by combining the arrangement locations of the non-contact portions shown in the first to sixth embodiments. The strain gauge 16 can be disposed at various locations as long as it can detect the load of the pump device as the strain amount at the arrangement location, which is a non-contact portion of the fluid to be transferred, and thus is not limited to the above-described arrangement mode.

Description of Reference Numerals

[0086] 10 Drive mechanism 11 Shaft member 11a First member 11b Second member 16 Strain gauge 20 Pump body 21, 25 Accommodation space 26 Front housing 27 Rear housing 29 Control board 29a Sensor board 30 Pump head 31 Pump chamber 40 Adapter member 50 Diaphragm 54 Retainer member 60 Gasket member 73 Control unit 74 Estimation unit 75 Memory unit 100 Pump device

Claims

1. A pump head having a suction port and a discharge port for a transfer fluid, a diaphragm attached to the pump head to form a pump chamber that communicates the suction port and the discharge port, a rod-shaped shaft member connected to the central portion of the diaphragm and provided so as to be movable in the reciprocating direction of the diaphragm, a drive mechanism capable of driving the shaft member in the reciprocating direction of the diaphragm, and a pump body including a control unit for controlling the drive mechanism, A pump device comprising: a sensor unit disposed on an outer peripheral portion near the connection portion of the shaft member with the diaphragm in the pump device, and detecting strain generated on the outer peripheral portion of the shaft member during operation of the pump device; an estimation unit for estimating an actual flow rate of the transfer fluid or a pressure of the transfer fluid in the pump device based on a strain amount of the outer peripheral portion of the shaft member detected by the sensor unit; Comprising a pump device.

2. The control unit controls the operation of the drive mechanism so that the actual flow rate of the transfer fluid becomes a preset flow rate based on the estimation result of the actual flow rate by the estimation unit The pump device according to claim 1.

3. Further comprising a storage unit for storing information indicating a ratio of actual flow rate related to a flow rate reduction rate or an actual flow rate rate of the actual flow rate based on the set flow rate with respect to the potential difference of the waveform data representing the strain amount for each number of strokes of the shaft member created in advance, The estimation unit estimates the actual flow rate by referring to the information indicating the ratio of actual flow rate in the storage unit from the potential difference of the waveform data representing the strain amount. The pump device according to claim 2.

4. The control unit further includes a display unit that visually displays the information on the estimated actual flow rate together with the set flow rate The pump device according to claim 3.

5. When the output value of the waveform data representing the strain amount after a predetermined time has elapsed from the start timing of the suction period of the pump device is greater than a predetermined threshold value, or when the output value of the waveform data representing the strain amount after a predetermined time has elapsed from the start timing of the discharge period of the pump device is less than a predetermined threshold value, the estimation unit estimates the operating state of the pump device as abnormal operation The pump device according to claim 1.

6. A plurality of the sensor units are arranged on the outer peripheral portion of the shaft member The pump device according to any one of claims 1 to 5.

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