Pump device

Abstract

The invention provides a pump device which can be configured at low cost and can easily estimate the flow rate and the operation state of the pump device without being affected by the characteristics of the conveyed fluid and the pipeline conditions. The pump device is provided with a pump head having a suction port and a discharge port for conveying fluid, and a diaphragm attached to the pump head and forming a pump chamber for communicating the suction port and the discharge port; and a pump body including 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 further provided with: a sensor unit for sensing the reciprocating member in the reciprocating direction of the diaphragm; a strain sensor that is provided in a portion of the pump device that is not in contact with the conveyed fluid, and that detects strain generated at the non-contact portion when the pump device is operated; and an estimation unit that estimates the actual flow rate of the conveyed fluid in the pump device or the pressure of the conveyed fluid.

Description

Technical Field

[0001] The invention relates to a pump device. Background Art

[0002] Conventionally, a pump device is known that has a structure in which a pump head is mounted on a pump body that houses a pump drive mechanism. For example, in a pump device in which a reciprocating member such as a diaphragm reciprocates, a pressure sensor mounted on the pump head or the like is used to obtain the pressure in the pump chamber, and the flow rate of the conveyed fluid is determined to determine the operating state, thereby suppressing malfunctions caused by, for example, a large amount of bubbles accumulated in the pump chamber (see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6022943 Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] However, in the prior art pump device disclosed in the above-mentioned Patent Document 1, a structure is adopted in which the pressure sensor is arranged at a position in contact with the conveying fluid. Therefore, the pump device is not suitable for conveying a conveying fluid having characteristics that may cause the expensive pressure sensor to deteriorate or malfunction. In this case, there are problems such as being unable to determine the flow rate of the conveying fluid, and being unable to determine the operating state of the pump device based on the determination.

[0008] On the other hand, there are cases where a flow meter is installed on a pipe of a pump device or the like to measure the flow rate of a conveyed fluid. However, in this case, there are problems that the cost of the flow meter increases and the conditions of various pipes are limited.

[0009] 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 constructed at low cost and can easily estimate the flow rate, pressure, and operating state of the pump device without being affected by the characteristics of the conveyed fluid and the pipe conditions.

[0010] Solutions to technical problems

[0011] The pump device involved in the present invention comprises: a pump head formed with an intake port and an exhaust port for conveying a fluid; a diaphragm attached to the pump head and forming a pump chamber connecting the intake port and the exhaust port; and a pump body, which includes: a reciprocating component connected to the diaphragm and arranged to be movable along the reciprocating direction of the diaphragm, a driving mechanism capable of driving the reciprocating component along the reciprocating direction of the diaphragm, and a control unit that controls the driving mechanism, the pump device comprises: a sensor unit, which is arranged at a portion of the pump device that is non-contact with the conveying fluid and detects strain generated at the non-contact portion when the pump device is operating; and an inference unit, which infers the actual flow rate of the conveying fluid in the pump device or the pressure of the conveying fluid based on the strain amount of the non-contact portion detected by the sensor unit.

[0012] In one embodiment of the present invention, the control unit controls the operation of the driving mechanism based on the estimation result of the actual flow rate obtained by the estimation unit so that the actual flow rate of the conveying fluid becomes a preset set flow rate.

[0013] In another embodiment of the present invention, it also includes a storage unit, which stores pre-made information at each stroke number of the reciprocating component, which shows the actual flow ratio corresponding to the potential difference of the waveform data representing the strain amount, and the inference unit infers the actual flow rate based on the potential difference of the waveform data representing the strain amount and with reference to the information showing the actual flow ratio in the storage unit.

[0014] In still another embodiment of the present invention, the control unit further includes a display unit configured to display information of the estimated actual flow rate together with a set flow rate in a visually recognizable manner.

[0015] In another embodiment of the present invention, the inference unit infers that the operating state of the pump device is abnormal operation when the output value of the waveform data representing the strain amount after a specified time has passed from the start time of the suction period of the pump device is greater than a specified threshold value, or when the output value of the waveform data representing the strain amount after a specified time has passed from the start time of the discharge period of the pump device is less than a specified threshold value.

[0016] In still another embodiment of the present invention, the sensor portion is provided at the non-contact portion of the outer peripheral portion near a portion of the reciprocating member connected to the diaphragm.

[0017] In still another embodiment of the present invention, a plurality of the sensor portions are provided at the non-contact location.

[0018] In another embodiment of the present invention, the sensor portion is arranged at the non-contact portion of at least one of the following portions: a reinforcement portion installed on the front side of the pump head, a fixture portion provided on the back side of the diaphragm, a bracket portion installed on the front side of the driving mechanism, an outer peripheral portion of the reciprocating motion portion located further rearward than the front of the bracket portion, and an upper portion of the driving mechanism.

[0019] Effects of the Invention

[0020] According to the present invention, a pump device 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 conveyed fluid and the pipe conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a side sectional view schematically showing a pump device according to a first embodiment of the present invention.

[0022] Figure 2 yes Figure 1 A-vector view.

[0023] Figure 3 : is a block diagram schematically showing the circuit configuration of the pump device.

[0024] Figure 4 : is a graph showing an example of the estimated flow rate and the actually measured flow rate of the pump device.

[0025] Figure 5 : is a graph showing an example of the estimated flow rate and the actually measured flow rate of the pump device.

[0026] Figure 6 Graphs showing, by example, the suction period and discharge period of the pump device and the waveform data of the strain amount.

[0027] Figure 7 2 is a diagram showing an example of data stored in the storage unit of the pump device.

[0028] Figure 8 2 is a diagram showing a display example on the display unit of the pump device.

[0029] Fig. 9 It is a cross-sectional view schematically showing the installation position of the sensor unit in the pump device according to the second embodiment of the present invention.

[0030] Fig.10 It is a cross-sectional view schematically showing the installation position of a sensor unit in a pump device according to a third embodiment of the present invention.

[0031] Fig.11 It is a cross-sectional view schematically showing the installation position of a sensor unit in a pump device according to a fourth embodiment of the present invention.

[0032] Fig.12 It is a cross-sectional view schematically showing the installation position of the sensor unit in the pump device according to the fifth embodiment of the present invention.

[0033] Fig.13 This is a cross-sectional view schematically showing the installation position of a sensor unit in a pump device according to a sixth embodiment of the present invention. DETAILED DESCRIPTION

[0034] Hereinafter, a pump device according to an embodiment of the present invention will be described in detail with reference to the drawings. However, the following embodiments do not limit the invention according to the claims, and not all combinations of features described in the embodiments are essential to the solution of the invention.

[0035] In addition, in the following embodiments, the same or equivalent components are marked with the same reference numerals and repeated descriptions are omitted. In addition, in the embodiments, the arrangement, proportion, size, etc. of each component are sometimes exaggerated or reduced to be expressed in a state inconsistent with the actual state, and sometimes the description of some components is omitted for expression.

[0036] [First embodiment]

[0037] [Structure of the pump device]

[0038] Figure 1 It is a side cross-sectional view schematically showing a pump device according to a first embodiment of the present invention. Figure 2 yes Figure 1 A-vector view. Figure 3 It is a block diagram schematically showing the circuit configuration of the pump device.

[0039] like Figure 1 As shown, the pump device 100 of the first embodiment includes: a pump body 20 having a drive mechanism 10 as a drive source (drive unit) and a control substrate 29; and a pump head 30 mounted on the front side of the pump body 20. It should be noted that the basic structure of the pump device 100 of this embodiment, including the internal structure, can be composed of a so-called ordinary pump device, so the known structure is not described in detail below and only the outline is described.

[0040] The pump device 100 also includes: an adapter component 40, which is arranged between the pump head 30 and the pump body 20, and is used to install the pump head 30 on the pump body 20; and a diaphragm 50, which is clamped by the adapter component 40 and installed on the pump head 30, and is connected to the shaft component 11 serving as the reciprocating motion component of the driving mechanism 10 through the adapter component 40.

[0041] In addition, the pump device 100 further includes a strain gauge 16 as a sensor portion provided at a portion of the pump device 100 that is not in contact with the conveyed fluid. Hereinafter, the direction of the pump body 20 toward the pump head 30 is referred to as the front, and the direction toward the side opposite to the front is referred to as the rear. Figure 1 As indicated by arrows in FIG. 1 , the forward and backward movement directions of the diaphragm 50 and the shaft member 11 are referred to as reciprocating movement directions RD.

[0042] [Structure of the driving mechanism]

[0043] The driving mechanism 10 includes, for example, a motor 12, an eccentric cam mechanism 13, and a shaft member 11. The motor 12 drives the rotating shaft 13a of the eccentric cam mechanism 13 to rotate via a gear mechanism 12a. The eccentric cam mechanism 13 converts the rotating motion of the rotating shaft 13a into the reciprocating motion of the shaft member 11 via an eccentric cam portion 13b. The shaft member 11 is driven in the reciprocating motion direction RD in the forward and backward directions by the reciprocating motion converted by the eccentric cam mechanism 13.

[0044] The shaft component 11 is made of, for example, a rod-shaped metal component or a resin component, and includes: a first component 11a arranged on the front side in a manner connected to the diaphragm 50, and a second component 11b connected to the rear side of the first component 11a and connected to the eccentric cam portion 13b of the eccentric cam mechanism 13.

[0045] While the shaft member 11 is pushed forward by the eccentric cam portion 13b, the front flange portion 11c of the second member 11b is pushed forward by the repulsive force of the spring member 14, thereby moving toward the front side of the pump body 20, causing the diaphragm 50 to be displaced in the forward direction. In addition, the shaft member 11 is pulled back toward the rear side by the eccentric cam portion 13b with a force stronger than the repulsive force of the spring member 14, thereby moving toward the rear side of the pump body 20, causing the diaphragm 50 to be displaced in the backward direction.

[0046] In this way, the shaft member 11 is pushed and pulled by the eccentric cam portion 13b in the drive mechanism 10 to repeat the above-mentioned forward and backward movements, thereby reciprocating in the reciprocating direction RD. It should be noted that a bracket portion 15 as a bracket member is provided on the front side (front) of the drive mechanism 10, facing the front opening portion 20a of the pump body 20, so as to install the adapter member 40 described below.

[0047] In addition, the driving mechanism 10 is not limited to the structure having the motor 12 and the eccentric cam mechanism 13 as described above, as long as its structure can drive the shaft component 11 at least in the forward or backward direction of the diaphragm 50 as described above. For example, it may also be a structure that uses an actuator that directly drives the shaft component 11 using, for example, electromagnetic force.

[0048] [Pump body structure]

[0049] The housing portion constituting the pump body 20 is formed 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 includes a front opening 20a provided on the front side, and a storage space 21 provided above the pump base 20b and connected to the front opening 20a. The rear housing 27 includes a storage space 25 capable of storing a control substrate 29.

[0050] The storage space 21 in the front housing 26 of the pump body 20 is formed, for example, in a cylindrical shape, and is configured so that a portion (for example, the lower side) thereof is connected to the inside of the pump base 20b. The storage space 25 in the rear housing 27 of the pump body 20 is separated from the storage space 21 in the reciprocating direction RD, but is formed in the same shape as the storage space 21 or in a rounded rectangular shape, and is configured so that a portion (for example, the lower side) thereof is connected to the inside of the pump base 20b.

[0051] The storage space 21 of the front housing 26 mainly stores the drive mechanism 10, and also stores, for example, a wiring tube 19a that stores the cable 19 as wiring and surrounds the drive mechanism 10, and the bracket portion 15 described above. The front housing 26 has a rear wall 22 provided on the rear side. The rear housing 27 is mounted on the back side (rear side surface) 22a of the rear wall 22 of the front housing 26 by screwing using mounting screws 27a.

[0052] The control board 29 is directly mounted on the rear case 27 by screwing with the mounting screws 27b. The cables 19 of the wiring duct 19a are connected to the control board 29. The control board 29 controls the driving mechanism 10 and controls the operation of the pump device 100 as a whole.

[0053] An operation unit 28 is provided at the rear of the pump body 20 for an operator to input operation such as setting operation of the pump device 100. The operation unit 28 includes a display unit 28a that visually displays various information related to the pump device 100.

[0054] [Setting of sensor unit]

[0055] The strain gauge 16 as a sensor is provided at a location not in contact with the conveyed fluid, for example, at the outer periphery of the first member 11a of the shaft member 11 near the location connected to the diaphragm 50. The strain gauge 16 detects strain generated at the outer periphery of the first member 11a when the pump device 100 is in operation.

[0056] like Figure 2 As shown in the figure, the strain gauge 16 is attached to the outer periphery of the first component 11a by adhesive or the like. However, the arrangement of the strain gauge 16 is not limited to this. The strain gauge 16 may also be arranged separately on the outer periphery of the first component 11a as shown in the figure. In the present embodiment, although the illustration is omitted, a plurality of (for example, two) strain gauges are arranged on the outer periphery of the first component 11a.

[0057] The strain gauge 16 is connected to a lead 16a extending in a direction intersecting the reciprocating motion direction RD. The lead 16a extending from the strain gauge 16 is protected by, for example, a silicone coating. A connector 16b is connected to the end of the lead 16a. The connector 16b is connected to a relay connector 16c provided on a portion of the bracket portion 15. The relay connector 16c is connected to, for example, a sensor substrate 29a provided on the upper portion of the drive mechanism 10 through a cable 19b and a connector 16d. Since the sensor substrate 29a is connected to the cable 19 through the connector 16e, the strain gauge 16 is electrically connected to the control substrate 29 through the lead 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.

[0058] [Pump head structure]

[0059] The pump head 30 is formed of, for example, a resin component or a metal component 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 the diaphragm 50 mounted on the pump head 30, and its volume changes with the displacement of the diaphragm 50. It should be noted that in the pump device 100 of the present embodiment, a reinforcing plate 30a as a reinforcing component for reinforcing the mechanical strength of the pump head 30 and a cover component 30b for protecting the reinforcing plate 30a are installed on the front side of the pump head 30.

[0060] The pump head 30 is mounted on the front opening 20a side of the front housing 26 through, for example, an adapter member 40 mounted on the bracket portion 15 of the drive mechanism 10. The pump head 30 has a suction port 32 and a discharge port 33 for conveying fluid that are connected to the pump chamber 31. The suction port 32 is connected to, for example, the bottom of the pump chamber 31. The discharge port 33 is connected to, for example, the top of the pump chamber 31.

[0061] The pump head 30 has a first connection port 34 disposed below the suction port 32 and on the suction side of the conveying fluid. In addition, the pump head 30 has a second connection port 35 disposed above the discharge port 33 and on the discharge side of the conveying fluid. The first connection port 34 and the second connection port 35 are connected to the pump chamber 31 through the suction port 32 and the discharge port 33, respectively.

[0062] A cylindrical suction-side adapter 37 is connected to the first connection port 34 via a connection nut 37a with a suction valve 36a assembled thereto. A cylindrical discharge-side adapter 38 is connected to the second connection port 35 via a connection nut 37b with a discharge valve 36b assembled thereto.

[0063] The suction side adapter 37 is connected to the suction side pipe (not shown) and connects the suction port 32 of the pump head 30 to the suction side flow path 39a via the suction valve 36a. The discharge side adapter 38 is connected to the discharge side pipe (not shown) and connects the discharge port 33 of the pump head 30 to the discharge side flow path 39b via the discharge valve 36b.

[0064] [Structure of the adapter part]

[0065] The adapter member 40 is formed of, for example, a resin member. The adapter member 40 is disposed between the pump head 30 and the pump body 20 (the front opening 20a of the front housing 26), and blocks the front opening 20a to close the storage space 21. The adapter member 40 has, for example, a plurality of mounting holes (not shown) disposed at a predetermined pitch, and a plurality of through holes (not shown) disposed at a predetermined pitch different from the plurality of mounting holes.

[0066] The adapter member 40 is fixed to the bracket portion 15 by a fastening means such as a bolt (not shown) inserted into the mounting hole. Thus, the adapter member 40 is mounted on the pump body 20 in a manner that blocks the front opening 20a of the front housing 26. It should be noted that, for example, by fastening the bolt 42a that passes through the reinforcing plate 30a and the insertion hole of the adapter member 40 to the bracket portion 15 provided at the rear of the adapter member 40, the pump head 30 is mounted on the front side of the pump body 20 in a liquid-tight manner through the adapter member 40.

[0067] The adapter member 40 includes, for example, an annular protrusion 43 that holds the fixing portion 51 of the diaphragm 50 located at the outer periphery together with the pump head 30, and a wall portion 44 that is continuous with the inner peripheral wall surface 43a of the annular protrusion 43. A circular central hole 46 is formed at the center of the wall portion 44 of the adapter member 40.

[0068] It should be noted that the washer member 60 is mounted on the back side (the surface on the front housing 26 side) 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 washer member 60 is formed of rubber, for example. The washer member 60 has a disk portion 61 that contacts the back side of the wall portion 44, and a central convex portion 62 that is provided at the center of the disk portion 61 and has a concave-convex shape in the reciprocating direction RD (a serpentine shape in a direction intersecting the reciprocating direction RD).

[0069] The central protrusion 62 of the gasket member 60 is inserted into the central hole 46 of the wall portion 44 of the adapter member 40 in a liquid-tight manner. In addition, the first member 11a of the shaft member 11 is inserted into the central hole 63 of the central protrusion 62 in a liquid-tight manner. Therefore, the outer peripheral portion of the first member 11a of the shaft member 11 provided with the strain gauge 16 is arranged to be located at a position further rearward than the central hole 63 of the central protrusion 62 of the gasket member 60, so it does not contact with the conveying fluid flowing through the suction port 32, the pump chamber 31 and the discharge port 33, but is in a non-contact state.

[0070] [Structure of the diaphragm]

[0071] The diaphragm 50 is connected to the first member 11a of the shaft member 11 inserted into the central hole 63 of the central protrusion 62 of the washer member 60 by the insertion bolt 52. The diaphragm 50 is an elastic member having the insertion bolt 52 connected to the first member 11a integrally molded therein with a resin such as ethylene propylene rubber (EPDM) and polytetrafluoroethylene (PTFE).

[0072] The diaphragm 50 is driven to be displaced in the reciprocating direction RD by the driving mechanism 10 housed in the front housing 26 of the pump body 20, so as to change the volume of the pump chamber 31 of the pump head 30. The diaphragm 50 is installed in a liquid-tight manner in a state where the fixing portion 51 is clamped between the pump head 30 and the annular protrusion 43 of the adapter member 40 as described above and the front side of the central portion 53 faces the pump chamber 31. It should be noted that, between the diaphragm 50 and the front end of the first member 11a of the shaft member 11, for example, a fixing member 54 for maintaining the shape of the diaphragm 50 and holding the position of the diaphragm 50 is provided.

[0073] In the pump device 100 thus configured, when, for example, the strain gauge 16 must be replaced, the pump head 30, the diaphragm 50, and the adapter member 40 can be removed from the pump body 20, and the connector 16b can be removed from the relay connector 16c, and then the strain gauge 16 can be replaced together with the first member 11a of the shaft member 11. Therefore, a structure is realized in which the strain gauge 16 can be easily replaced and the pump head 30 can be easily maintained.

[0074] [Circuit structure of pump device]

[0075] like Figure 3 As shown, the circuit structure 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); a differential amplifier circuit 72 including 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 inference unit 74 and a storage unit 75.

[0076] The circuits 71 and 72 of the sensor substrate 29a are appropriately designed according to various data and conditions such as the main specifications of the pump device 100. The components 73 to 75 of the control substrate 29 are appropriately configured by combining known hardware such as CPU, RAM, and ROM.

[0077] The bridge circuit 71 includes the strain gauge 16 as the resistor R1 and the strain gauge 16 as the resistor R2 provided on adjacent sides of the bridge, and the resistors R3 and R4 as two fixed resistors, and is configured to further reduce the apparent strain caused by temperature.

[0078] The differential amplifier circuit 72 is configured to amplify the output (strain detection signal) from the bridge circuit 71 to a predetermined value, remove noise, and perform temperature compensation by appropriately adjusting the values ​​of four resistors R5 to R8 connected to the operational amplifier 72a.

[0079] Therefore, when the pump device 100 is operating, the detection signal of the strain gauge 16 output from the bridge circuit 71 is amplified and noise-removed in the differential amplifier circuit 72 after temperature compensation, and can be input into the inference unit 74 as waveform data representing the strain amount of the outer periphery of the first component 11a of the shaft component 11.

[0080] The inference unit 74 infers the flow rate or pressure of the conveying fluid in the pump device 100 based on the input waveform data. That is, the flow rate and pressure of the conveying fluid of the pump device 100 will change with the load. The pressure change inside the pump head 30 (for example, inside the pump chamber 31) generated when the pump device 100 is running is applied to the shaft member 11 as a load change through the diaphragm 50. Therefore, a strain proportional to the load (load) is generated.

[0081] The generated strain is detected by the strain gauge 16 , and the estimation unit 74 estimates the flow rate or pressure of the conveyed fluid in the pump device 100 based on the waveform data indicating the strain amount output via the bridge circuit 71 and the differential amplifier circuit 72 .

[0082] On the other hand, the control unit 73 controls the operation of the driving mechanism 10 based on the flow estimation result obtained by the estimation unit 74 so that the actual flow rate (actual flow rate) of the conveyed fluid becomes, for example, a preset set flow rate. It should be noted that the storage unit 75 stores, for example, information (actual flow rate ratio data) on the flow rate drop rate or actual flow rate relative to the potential difference of the waveform data representing the strain amount at the number of strokes per minute (spm: strokes per minute) of each shaft member 11, which is made by pre-measurement, etc. 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.

[0083] In addition, when the gas is inhaled, when the gas is sucked into the pump chamber 31, the rise of the waveform data representing the strain amount will be delayed due to the compression of the gas. Therefore, the inference unit 74 grasps the gas intake state by setting a threshold value for the output value after a certain time (after a specified time) from the rise of the waveform data.

[0084] In this way, the inference unit 74 can further infer the operating state of the pump device 100 based on the inferred actual flow rate, for example, at what level the actual flow rate is operating relative to the set flow rate, or whether the operating state is abnormal, etc. Then, the control unit 73 can perform flow correction calculations for making the actual flow rate of the conveyed fluid become the set flow rate based on the inference result of the actual flow rate obtained by the inference unit 74, for example, using the above-mentioned actual flow rate ratio data, and let the drive mechanism 10 operate in a manner that corrects the flow rate. It should be noted that the display unit 28a in the operating unit 28 can display the notification information related to the operating state of the pump device 100 inferred by the inference unit 74 in a manner visible to the operator.

[0085] Figure 4 and Figure 5 is a graph showing an example of the estimated flow rate of the pump device 100 and the actually measured flow rate. Figure 4 Set the flow rate to 60 [L / H], Figure 5 In the figure, the set flow rate is set to 1.0 [L / H], and the vertical axis represents the flow rate [L / H] and the horizontal axis represents the pressure [MPa].

[0086] like Figure 4 Curve 77a and Figure 5As shown in the curve 77b, no matter the flow rate is set to 60 [L / H] or 1.0 [L / H], in either case when the pump pressure increases, the flow rate tends to decrease. The approximate curve 77c of the inferred flow rate represented by the dotted line in the figure is drawn to have almost the same curve shape as the approximate curve 77d of the actual flow rate represented by the solid line. The results of the inferred flow rate and the actual flow rate represented in this way are compared by calculation. The result is that the error of the inferred flow rate relative to the actual flow rate is within ±2.08 [%RS] in terms of scale accuracy, so it is shown that the inference unit 74 can perform flow rate inference with high accuracy. Here, the pressure of the pump has a great correlation with the strain, as described above.

[0087] Figure 6 Graphs showing, by way of example, the suction period and discharge period of the pump device 100 and waveform data of the strain amount. Figure 7 The diagram shows an example of data stored in the storage unit 75 of the pump device 100, and shows an example of actual flow rate ratio data indicating a flow rate reduction rate, which is prepared by actually measuring in advance in the pump device 100 connected under predetermined pipe conditions.

[0088] like Figure 6 As shown, the high-level square wave U indicates that the pump device 100 is in the suction period when the conveying fluid is being sucked in, and the low-level square wave D indicates that the pump device 100 is in the discharge period when the conveying fluid is being discharged. This is obtained, for example, by a sensor cam signal not shown in the figure. On the other hand, the waveform data W shows the output waveform of the differential amplifier circuit 72, which, for example, indicates the strain amount obtained by detecting the stress change of the shaft component 11 of the pump device 100 using the strain gauge 16. The higher the level, the more it indicates that the shaft component 11 is in a state of bearing a load (the higher the load of the pump device 100). The waveform data W has the characteristic that its shape and level change according to the pressure value of the conveying fluid.

[0089] According to the Figure 6 It can be seen that during the suction period of the conveying fluid represented by the square wave U, the load applied to the shaft member 11 is reduced because the shaft member 11 is pulled back, so the waveform data W drops sharply and the level drops. On the other hand, it can be seen that during the discharge period of the conveying fluid represented by the square wave D, the load applied to the shaft member 11 increases with time because the shaft member 11 is pushed forward, so the waveform data W rises more slowly and the level becomes higher than when it drops as described above.

[0090] Then, for example, by inferring and acquiring the potential difference PD of the driving mechanism 10 from the waveform data W, wherein the potential difference PD is represented by the level position D1 of the waveform data W at the end of a certain cycle of the square wave D and the level position D2 of the waveform data W at the beginning of the next cycle of the square wave D, the pressure of the conveyed fluid can be identified as the potential difference PD. It should be noted that, although in this embodiment, in order to exclude the influence of noise in the "potential difference [V] of the waveform data representing the strain" as the input variable of the inference unit 74, the average value of the potential difference PD of three samples is used, the number of samples for which the average value is calculated may be more or less.

[0091] exist Figure 7 In the actual flow ratio data 78 representing the flow reduction rate, the row elements represent, for example, a plurality of potential differences [V] calculated based on the potential difference PD of three samples under a certain operating condition (number of strokes), and the column elements represent, for example, a plurality of stroke numbers [spm] set at 9 resolution levels, and correspondingly represent the numerical values ​​of the flow reduction rates corresponding to them.

[0092] It should be noted that the stroke number [spm] corresponds to the set flow rate [L / H]. In this example, the stroke number [spm] is 0.9-3.6, 3.6-9.0, 9.0-18.0, 18.0-36.0, 36.0-72.0, 72.0-108, 108-144, 144-180, 180-, and corresponds to the set flow rate [L / H] 0.3-1.2, 1.2-3.0, 3.0-6.0, 6.0-12.0, 12.0-24.0, 24.0-36.0, 36.0-48.0, 48.0-60.0, 60.0-, respectively.

[0093] like Figure 7 As shown, according to the actual flow ratio data 78 representing the flow reduction rate, for example, when the potential difference [V] is greater than 0.10 and less than 0.35, in any case where the stroke number [spm] is 0.9 to 180, the flow reduction rate is 0.00 (%), so it can be inferred that the actual flow rate remains at the set flow rate.

[0094] On the other hand, as the potential difference [V] gradually increases from 0.35 to 0.60, 0.60 to 0.85, ..., to greater than 2.70, the flow rate reduction rate at each stroke number [spm] gradually decreases. The flow rate reduction rate is the largest in the range of the maximum stroke number [spm] greater than 180, and the flow rate reduction rate at this time is 23.68%.

[0095] Then, the inference unit 74 receives the potential difference [V] and the flow rate setting value [L / H] (set number of strokes [spm]) as input variables, and calculates the flow rate based on the information stored in the storage unit 75. Figure 7The actual flow rate can be extrapolated from the table shown.

[0096] Figure 8 It is a diagram showing a display example on the display unit of the pump device.

[0097] like Figure 8 As shown, the display unit 28a included in the operation unit 28 is provided with: a first flow rate display area 28b, which displays the flow rate estimated by the estimation unit 74 as described above (and the actual flow rate calculated by calculation); and a second flow rate display area 28c, which displays the set flow rate set in advance by the operator, etc. In the display unit 28a, since the estimated flow rate and the set flow rate are displayed side by side in a manner that can be easily visually confirmed, the operator can easily grasp the operating state of the pump device 100.

[0098] It should be noted that the inference unit 74, for example, can perform calculations so that the stroke number [spm] becomes a multiple of the flow rate reduction rate plus 100 (flow rate reduction rate + 100 (%)), and enables the control unit 73 to control the action of the drive mechanism 10 so as to correct the flow rate of the component that is reduced based on the set flow rate so that it becomes the set flow rate again.

[0099] In addition, as described above, the inference unit 74 detects the pressure of the conveying fluid based on the waveform data representing the strain amount, and for example, when the output value of the waveform data representing the strain amount after a certain time has passed from the start time of the suction period of the pump device 100 is greater than a prescribed threshold value, or when the output value of the waveform data representing the strain amount after a certain time has passed from the start time of the discharge period is less than a prescribed threshold value, it is inferred that the operating state of the pump device 100 is abnormal. In addition, the inference unit 74 may also pay attention to whether the waveform shape of the waveform data from the rising position to the peak position is delayed compared with normal operation. Assuming that the waveform shape is a special shape that is more significantly delayed than normal operation from the start time of the discharge period shown by the square wave D, etc., indicating the operating state, it can also be inferred that a gas suction state has occurred and the operating state of the pump device 100 is abnormal operation. In these cases, notification information such as notifying the situation can also be displayed on the display unit 28a.

[0100] As described above, the pump device 100 according to the present embodiment can infer the flow rate and pressure of the fluid conveyed by the pump device 100 based on the amount of strain of the shaft member 11 detected by the strain gauge 16. Thus, an inexpensive structure can be obtained, and the flow rate and operating state can be easily inferred without being affected by the characteristics of the conveyed fluid and the pipe conditions, and the flow rate can be easily corrected and abnormal operation can be inferred.

[0101] [Second embodiment]

[0102] Fig. 9It is a cross-sectional view schematically showing the installation position of the sensor unit in the pump device according to the second embodiment of the present invention. It should be noted that in the following, overlapping descriptions of parts already described will be omitted.

[0103] like Fig. 9 As shown in the figure, the pump device 100A according to the second embodiment is different from the first embodiment in that, for example, the strain gauge 16 as the sensor portion is provided on the front face 30c side of the reinforcing plate 30a attached to the front face side of the pump head 30, which is a non-contact portion for conveying fluid. With this structure, the load of the pump device 100A can be detected in the form of a strain amount by the strain gauge 16, so that the same effect as the first embodiment can be achieved.

[0104] [Third embodiment]

[0105] Fig.10 It is a cross-sectional view schematically showing the installation position of a sensor unit in a pump device according to a third embodiment of the present invention.

[0106] like Fig.10 As shown in FIG. 1 , the pump device 100B according to the third embodiment is different from the first and second embodiments in that, for example, the strain gauge 16 as the sensor portion is provided on the back side (rear surface) 54a side of the fixing member 54 provided on the back side (rear side) of the diaphragm 50, which is a non-contact portion for conveying fluid. With this structure, the load of the pump device 100B can be detected in the form of a strain amount by the strain gauge 16, so that the same effects as those of the first and second embodiments can be exerted.

[0107] [Fourth embodiment]

[0108] Fig.11 It is a cross-sectional view schematically showing the installation position of a sensor unit in a pump device according to a fourth embodiment of the present invention.

[0109] like Fig.11 As shown in FIG. 1 , the pump device 100C according to the fourth embodiment is different from the first to third embodiments in that, for example, the strain gauge 16 as the sensor portion is provided on the back surface (rear surface) 15a side of the bracket portion 15 mounted on the front side of the drive mechanism 10, which is a non-contact portion for conveying fluid. With this structure, the load of the pump device 100C can be detected in the form of a strain amount by the strain gauge 16, so that the same effects as those of the first to third embodiments can be exerted.

[0110] [Fifth embodiment]

[0111] Fig.12It is a cross-sectional view schematically showing the installation position of a sensor unit in a pump device according to a fifth embodiment of the present invention.

[0112] like Fig.12 As shown, the pump device 100D according to the fifth embodiment is different from the first to third embodiments in that, for example, the strain gauge 16 as the sensor portion is provided on the outer periphery of the second member 11b of the shaft member 11 which is located further rearward than the front of the bracket portion 15, which is a non-contact portion for conveying fluid. With this structure, the load of the pump device 100D can be detected in the form of a strain amount by the strain gauge 16, so that the same effects as those of the first to fourth embodiments can be exerted.

[0113] [Sixth embodiment]

[0114] Fig.13 It is a cross-sectional view schematically showing the installation position of a sensor unit in a pump device according to a sixth embodiment of the present invention.

[0115] like Fig.13 As shown in FIG. 1 , the pump device 100E according to the sixth embodiment is different from the first to fifth embodiments in that, for example, a strain gauge 16 as a sensor portion is provided on the upper portion of the drive mechanism 10 (for example, the upper surface 13d of the bearing portion 13c of the eccentric cam mechanism 13) which is a non-contact portion for conveying fluid. With this structure, the load of the pump device 100E can also be detected in the form of a strain amount by the strain gauge 16, so that the same effects as those of the first to fifth embodiments can be exerted.

[0116] Several embodiments of the present invention are described above, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These new embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their variations are included in the scope and gist of the invention, and are also included in the invention described in the patent claims and their equivalents.

[0117] For example, in the first embodiment described above, the strain gauge 16 is provided on the outer periphery of the first part 11a of the shaft member 11, while in the second to sixth embodiments, the strain gauge 16 is provided at a non-contact portion of the conveying fluid that is different from the first embodiment. In addition, the strain gauge 16 may be provided in combination at the non-contact portion provided in the first to sixth embodiments. The position of the strain gauge 16 can be provided at various positions as long as the load of the pump device can be detected as a strain amount at the provided position, wherein the provided position is a non-contact portion of the conveying fluid, and is not limited to the above-described provided manner.

[0118] Description of Reference Numerals

[0119] 10. Driving mechanism

[0120] 11 Axis components

[0121] 11a Part 1

[0122] 11b Part 2

[0123] 16 Strain gauge

[0124] 20 Pump body

[0125] 21, 25 Storage space

[0126] 26 Front housing

[0127] 27 Rear housing

[0128] 29 Control board

[0129] 29a Sensor substrate

[0130] 30 Pump head

[0131] 31 Pump Room

[0132] 40 Adapter parts

[0133] 50 Diaphragm

[0134] 54 Fixing parts

[0135] 60 Washer parts

[0136] 73 Control Department

[0137] 74 Inference

[0138] 75 Storage

[0139] 100 Pump unit

Claims

1. A pump device comprising: A pump head having a suction port and a discharge port for conveying fluid, a diaphragm attached to the pump head and forming a pump chamber connecting the suction port and the discharge port; and The pump body comprises: a reciprocating member connected to the diaphragm and arranged to be movable along the reciprocating direction of the diaphragm, a driving mechanism capable of driving the reciprocating member along the reciprocating direction of the diaphragm, and a control unit for controlling the driving mechanism, Among them, it also has: a sensor portion provided at a portion of the pump device that is not in contact with the conveying fluid and that detects strain generated at the non-contact portion when the pump device is operated; and An estimating unit estimates an actual flow rate of the conveying fluid or a pressure of the conveying fluid in the pump device based on the strain amount of the non-contact portion detected by the sensor unit.

2. The pump device according to claim 1, characterized in that The control unit controls the operation of the driving mechanism based on the estimation result of the actual flow rate obtained by the estimation unit so that the actual flow rate of the conveying fluid becomes a preset set flow rate.

3. The pump device according to claim 2, characterized in that A storage unit is further included, the storage unit storing pre-made information at each stroke number of the reciprocating member, the information showing an actual flow rate ratio corresponding to a potential difference of the waveform data representing the strain amount, The estimation unit estimates the actual flow rate by referring to the information indicating the actual flow rate ratio in the storage unit based on the potential difference of the waveform data indicating the strain amount.

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

5. The pump device according to claim 1, characterized in that The inference unit infers that the operating state of the pump device is abnormal operation when the output value of the waveform data representing the strain amount after a specified time has passed from the start time of the suction period of the pump device is greater than a specified threshold value, or when the output value of the waveform data representing the strain amount after a specified time has passed from the start time of the discharge period of the pump device is less than a specified threshold value.

6. The pump device according to any one of claims 1 to 5, characterized in that The sensor portion is provided at the non-contact portion of the outer peripheral portion near a portion of the reciprocating member connected to the diaphragm.

7. The pump device according to any one of claims 1 to 5, characterized in that A plurality of the sensor parts are provided at the non-contact location.

8. The pump device according to any one of claims 1 to 5, characterized in that The sensor portion is arranged at the non-contact portion of at least one of the following portions: a reinforcing portion installed on the front side of the pump head, a fixing portion arranged on the back side of the diaphragm, a bracket portion installed on the front side of the driving mechanism, an outer peripheral portion of the reciprocating motion portion located further rearward than the front of the bracket portion, and an upper portion of the driving mechanism.

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