Corrugated pipe pump device

Abstract

A control unit (6) of a bellows pump device (1) performs pressure-increasing control in which, when a first bellows (13) (second bellows (14)) is contracted to a contracted state, whether or not the second bellows (14) (first bellows (13)) is being stretched is determined, and when the determination result is affirmative, when the second bellows (14) (first bellows (13)) is being stretched next time, the second bellows (14) (first bellows (13)) is not stretched next time, and when the determination result is affirmative, the second bellows (14) (first bellows (13)) is not stretched next time. A boost command is output to a second electropneumatic regulator 52 (first electropneumatic regulator 51) such that the pressure of pressurized air supplied to a second suction-side air chamber 26B (first suction-side air chamber 26A) of a second drive unit 28 (first drive unit 27) increases. The control unit (6) counts the number of times the boost control has been performed continuously, and determines that the second electro-pneumatic regulator (52) (first electro-pneumatic regulator (51)) is abnormal when the counted number of times exceeds a predetermined number of times.

Description

Technical Field

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

[0002] In semiconductor manufacturing, chemical industry, etc., as a bellows pump for conveying and supplying a conveying fluid such as a liquid medicine or a solvent, for example, a bellows pump described in Patent Document 1 is known. The bellows pump described in Patent Document 1 comprises: a pair of bellows that are independently expanded and contracted to suck and discharge the conveying fluid relative to the inside; and a pair of cylinders that expand and contract each bellows by supplying and discharging pressurized air. The bellows pump controls the drive of each cylinder in the following manner, that is, before one bellows is about to be maximally contracted (discharge ends), the other bellows is contracted from the maximally extended state to discharge the conveying fluid.

[0003] By controlling the drive of each cylinder as described above, when one bellows switches from contraction to extension (switches from discharge of the transported fluid to suction), the other bellows is already contracted to discharge the transported fluid. This can reduce the situation where the discharge pressure of the transported fluid drops significantly at the timing, thereby reducing the pulsation on the discharge side of the bellows pump.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2004-293502 Summary of the invention

[0005] In the above-mentioned bellows pump, before one bellows is about to contract to the maximum (end of discharge), the other bellows needs to be extended to the maximum (end of suction) in advance. However, if the ambient temperature, the flow rate of the conveyed fluid, etc. change, the hardness of the bellows will change due to their influence. If the hardness of the bellows changes, the extension time (suction time) of the bellows will change, the pulsation on the discharge side will worsen, or the impact pressure and cavitation called "water hammer" will be generated, which may have an adverse effect on the bellows pump.

[0006] Therefore, the applicant of the present application has proposed the following bellows pump device, that is, in order to make the extension time of the bellows reach an appropriate time, the air pressure of the pressurized air supplied to the air chamber of the cylinder is automatically reset to an appropriate value by using an electric pneumatic regulator (International Application No. PCT / JP2021 / 034699). Regarding the bellows pump device, when one bellows is contracted to a mid-contraction state, if the other bellows has not been extended to a specified extension state, the control unit performs a pressure increase control to increase the air pressure of the pressurized air supplied to the air chamber of the cylinder when the other bellows is extended next time. In addition, when one bellows is contracted to a mid-contraction state, if the specified extension state of the other bellows continues for more than a specified time, the control unit performs a pressure reduction control to reduce the air pressure of the pressurized air supplied to the air chamber of the cylinder when the other bellows is extended next time.

[0007] However, in the event of an abnormality such as a malfunction of the electro-pneumatic regulator, the electro-pneumatic regulator usually maintains the air pressure adjusted just before the abnormality occurs. Therefore, pressurized air of the air pressure adjusted just before the abnormality occurs is always supplied to the cylinder, and the pressurized air is used to continuously extend and retract the bellows. In this way, if the expansion and contraction action of the bellows continues, the elongation time of the bellows changes, which may have an adverse effect on the bellows pump as described above. As a countermeasure, it is considered to monitor the air pressure of the electro-pneumatic regulator. However, in this case, it is necessary to newly connect other lines for monitoring the air pressure, a pressure gauge for detecting the air pressure, etc. to the output line of the electro-pneumatic regulator, resulting in increased costs.

[0008] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a bellows pump device capable of detecting the occurrence of abnormality in a fluid pressure regulating unit with an inexpensive structure.

[0009] (1) The present invention is a bellows pump device, comprising: a pair of bellows that are able to expand and contract independently of each other, and suck the conveying fluid into the interior by expanding, and discharge the conveying fluid from the interior by contracting; a pair of driving parts, which have a suction side fluid chamber and a discharge side fluid chamber, and each of the bellows is extended to a specified extended state by supplying a pressurized fluid to the suction side fluid chamber, and each of the bellows is contracted to a specified contracted state by supplying a pressurized fluid to the discharge side fluid chamber; a pair of fluid pressure adjusting parts, which adjust the fluid pressure of the pressurized fluid supplied to the suction side fluid chamber of each driving part; a pair of detection parts, which detect the expansion and contraction state of each bellows; and a control part, which controls the pair of driving parts and the pair of fluid pressure adjusting parts based on the detection signals of the pair of detection parts, and the control part performs drive control and boost control, in which a pair of driving units are controlled in such a manner that one of the pair of bellows is caused to contract from the extended state before the other bellows is about to reach the contracted state, and in which a boost control is performed when one bellows is contracted to a contraction midway state before reaching the contraction state, a boost judgment is performed to determine whether the other bellows is in the middle of extension, and when the result of the boost judgment is affirmative, a boost command is output to the fluid pressure regulating unit corresponding to the driving unit that extends the other bellows in such a manner that the fluid pressure is increased the next time the other bellows is extended, and the number of times the boost control is performed continuously is counted, and when the counted number exceeds a specified number, it is determined that the fluid pressure regulating unit is abnormal.

[0010] With regard to the bellows pump device of the present invention, when an abnormality occurs in the fluid pressure regulating unit and the fluid pressure adjusted immediately before the abnormality occurs in the fluid pressure regulating unit is maintained, even if the control unit outputs a boost command for boost control to the fluid pressure regulating unit, the fluid pressure cannot be increased by the fluid pressure regulating unit. Therefore, the control unit continuously outputs a boost command to the fluid pressure regulating unit. The inventors of the present application have completed the present invention with an eye on this point. That is, the control unit counts the number of times the boost control is continuously performed, and when the counted number exceeds a prescribed number, it is determined that the fluid pressure regulating unit is abnormal. Thus, it is possible to grasp the situation in which an abnormality occurs in the fluid pressure regulating unit with an inexpensive structure that does not use a pressure gauge or the like.

[0011] (2) From another point of view, the present invention is a bellows pump device, comprising: a pair of bellows that are free to expand and contract independently of each other, and suck the conveying fluid into the interior by expanding, and discharge the conveying fluid from the interior by contracting; a pair of driving parts, which have an intake side fluid chamber and a discharge side fluid chamber, and each of the bellows is expanded to a specified extended state by supplying a pressurized fluid to the intake side fluid chamber, and is contracted to a specified contracted state by supplying a pressurized fluid to the discharge side fluid chamber; a pair of fluid pressure adjusting parts, which adjust the fluid pressure of the pressurized fluid supplied to the intake side fluid chamber of each driving part; a pair of detection parts, which detect the expansion and contraction state of each bellows; and a control part, which controls the pair of driving parts and the pair of fluid pressure adjusting parts based on the detection signals of the pair of detection parts, and the control part performs drive control and Pressure reduction control, in which a pair of driving parts are controlled in such a manner that one of the bellows is caused to contract from the extended state before the other bellows is about to reach the contracted state. In the pressure reduction control, when one bellows is contracted to a contracted midway state before reaching the contracted state, a pressure reduction judgment is made to determine whether the extended state of the other bellows has continued for more than a prescribed time. When the result of the pressure reduction judgment is affirmative, a pressure reduction command is output to the fluid pressure regulating part corresponding to the driving part that extends the other bellows in such a manner that the fluid pressure is reduced when the other bellows is extended next time. The number of times the pressure reduction control is performed continuously is counted. When the counted number exceeds a prescribed number, it is determined that the fluid pressure regulating part is abnormal.

[0012] With regard to the bellows pump device of the present invention, when an abnormality occurs in the fluid pressure regulating unit and the fluid pressure adjusted immediately before the abnormality occurs in the fluid pressure regulating unit is maintained, even if the control unit outputs a pressure reduction command for pressure reduction control to the fluid pressure regulating unit, the fluid pressure cannot be reduced by the fluid pressure regulating unit. Therefore, the control unit continuously outputs a pressure reduction command to the fluid pressure regulating unit. The inventors of the present application have completed the present invention with an eye on this point. That is, the control unit counts the number of times the pressure reduction control is continuously performed, and when the counted number exceeds a prescribed number, it is determined that the fluid pressure regulating unit is abnormal. Thus, it is possible to grasp the situation in which an abnormality occurs in the fluid pressure regulating unit with a cheap structure that does not use a pressure gauge or the like.

[0013] (3) On the basis of the bellows pump device of (1), preferably, the control unit also performs a pressure reduction control. In the pressure reduction control, when the one bellows contracts to the mid-contraction state, a pressure reduction judgment is performed to determine whether the extended state of the other bellows has continued for more than a specified time. When the result of the pressure reduction judgment is affirmative, a pressure reduction command is output to the fluid pressure regulating unit corresponding to the driving unit that extends the other bellows in such a manner that the fluid pressure is reduced when the other bellows is extended next time. The number of times the pressure reduction control is performed continuously is counted. When either the number of times the pressure increase control is performed continuously or the number of times the pressure reduction control is performed continuously exceeds a specified number, it is determined that the fluid pressure regulating unit is abnormal.

[0014] In this case, whether the pressure increase control is continuously performed or the pressure reduction control is continuously performed, it can be understood that an abnormality has occurred in the fluid pressure regulating unit.

[0015] (4) In the bellows pump device of (1) or (3) above, preferably, the control unit counts the number of times the result of the pressure increase determination is affirmative continuously as the number of times the pressure increase control is continuously performed.

[0016] In this case, the control unit can determine that the number of times the pressure increase control has been continuously performed exceeds a predetermined number before outputting a pressure increase command to the fluid pressure regulator. This makes it possible to quickly understand that an abnormality has occurred in the fluid pressure regulator.

[0017] (5) In the bellows pump device of (2) or (3), preferably, the control unit counts the number of times the result of the pressure reduction determination is consecutively affirmative as the number of times the pressure reduction control is consecutively performed.

[0018] In this case, the control unit can determine that the number of times the pressure reduction control has been continuously performed exceeds a predetermined number before outputting a pressure reduction command to the fluid pressure regulator. This makes it possible to quickly understand that an abnormality has occurred in the fluid pressure regulator.

[0019] Effects of the Invention

[0020] According to the bellows pump device of the present invention, it is possible to detect the occurrence of abnormality in the fluid pressure regulating unit with an inexpensive structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of a bellows pump device according to an embodiment.

[0022] Figure 2 It is a cross-sectional view of a bellows pump.

[0023] Figure 3 This is an explanatory diagram showing the operation of the bellows pump.

[0024] Figure 4 This is an explanatory diagram showing the operation of the bellows pump.

[0025] Figure 5 : is a timing chart showing an example of boost control.

[0026] Figure 6 : is a timing chart showing an example of voltage reduction control.

[0027] Figure 7 This is a flowchart showing an example of abnormality determination. DETAILED DESCRIPTION

[0028] Next, preferred embodiments will be described with reference to the drawings.

[0029] [Overall structure]

[0030] Figure 1 1 is a schematic diagram of the bellows pump device 1 according to the embodiment. The bellows pump device 1 according to the embodiment is used, for example, to quantitatively supply a liquid medicine, a solvent, or other transport fluid in a semiconductor manufacturing device. The bellows pump device 1 has an air supply device (fluid supply device).

[0031] 2, mechanical regulator 3, first solenoid valve 4, second solenoid valve 5, control unit 6, bellows pump 10, first electro-pneumatic regulator (fluid pressure regulator) 51, and second electro-pneumatic regulator (fluid pressure regulator) 52.

[0032] The air supply device 2 is constituted by, for example, an air compressor, and generates pressurized air (pressurized fluid) to be supplied to the bellows pump 10. The mechanical regulator 3 adjusts the air pressure (fluid pressure) of the pressurized air generated in the air supply device 2. The first electro-pneumatic regulator 51 and the second electro-pneumatic regulator 52 will be described later.

[0033] Figure 2 1 is a cross-sectional view of a bellows pump 10 according to the present embodiment. The bellows pump 10 according to the present embodiment comprises: a pump head 11 disposed in the center; a pair of pump housings 12 mounted on both sides of the pump head 11 in the left-right direction; a first bellows 13 and a second bellows 14 as a pair of bellows mounted on the left-right side of the pump head 11 inside each pump housing 12; and a total of four one-way valves 15 and 16 mounted on the left-right side of the pump head 11 inside each of the first and second bellows 13 and 14.

[0034] [Bellows]

[0035] The first bellows 13 and the second bellows 14 are formed into a bottomed cylindrical shape from a fluororesin such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA). The flanges 13a and 14a formed integrally at the open side ends of the first and second bellows 13 and 14 are pressed and fixed to the side of the pump head 11 in an airtight manner. The peripheral walls of the first and second bellows 13 and 14 are formed into a corrugated shape and are configured to be able to expand and contract freely in the left and right directions independently of each other.

[0036] A working plate 19 is fixed to the outer surface of the closed side end of the first and second bellows 13 and 14 by means of bolts 17 and nuts 18. The first and second bellows 13 and 14 can be extended and retracted between a maximum extension state in which the outer surface of the working plate 19 abuts against the inner surface of the bottom wall portion 121 of the bottomed cylindrical pump housing 12, and a maximum contraction state in which the inner surface of the piston body 23 described later abuts against the outer surface of the bottom wall portion 121.

[0037] [Pump housing]

[0038] The opening peripheral edge of the pump housing 12 (hereinafter also referred to as "first pump housing 12A") is pressed and fixed in an airtight manner to the flange portion 13a of the first bellows 13. As a result, a first discharge side air chamber (discharge side fluid chamber) 21A is formed on the outside of the first bellows 13 inside the first pump housing 12A, which maintains an airtight state.

[0039] The first pump housing 12A is provided with a first intake and exhaust port 22A, and the first intake and exhaust port 22A is connected to the air supply device 2 via the first solenoid valve 4, the first electro-pneumatic regulator 51, and the mechanical regulator 3 (see Figure 1 ). Thus, if pressurized air is supplied from the air supply device 2 to the interior of the first discharge side air chamber 21A, the first bellows 13 contracts to a predetermined contracted state (hereinafter referred to as "contracted state"). The contracted state of the first bellows 13 may be a maximum contracted state or a state immediately before reaching the maximum contracted state.

[0040] The opening peripheral edge of the pump housing 12 (hereinafter also referred to as "second pump housing 12B") is pressed and fixed in an airtight manner to the flange portion 14a of the second bellows 14. As a result, a second discharge side air chamber (discharge side fluid chamber) 21B is formed on the outside of the second bellows 14 inside the second pump housing 12B, which maintains an airtight state.

[0041] The second pump housing 12B is provided with a second intake and exhaust port 22B, and the second intake and exhaust port 22B is connected to the air supply device 2 via the second solenoid valve 5, the second electro-pneumatic regulator 52, and the mechanical regulator 3 (see Figure 1). Thus, if pressurized air is supplied from the air supply device 2 to the interior of the second discharge side air chamber 21B, the second bellows 14 contracts to a predetermined contracted state (hereinafter referred to as "contracted state"). The contracted state of the second bellows 14 may be a maximum contracted state or a state immediately before reaching the maximum contracted state.

[0042] The rod-shaped connecting member 20 passes through the bottom wall portion 121 of each pump housing 12A, 12B, and is supported on the bottom wall portion 121 in a manner that allows sliding in the left-right direction. The piston body 23 is fixed to the outer end of the connecting member 20 by a nut 24. The piston body 23 is supported on the inner circumferential surface of a cylindrical cylinder body 25 integrally provided on the outer side of the bottom wall portion 121 in a manner that allows sliding in the left-right direction while maintaining an airtight state.

[0043] Thus, on the first pump housing 12A side, the space surrounded by the bottom wall 121, the cylinder 25, and the piston body 23 forms a first suction side air chamber (suction side fluid chamber) 26A that is kept airtight. In addition, on the second pump housing 12B side, the space surrounded by the bottom wall 121, the cylinder 25, and the piston body 23 forms a second suction side air chamber (suction side fluid chamber) 26B that is kept airtight.

[0044] The cylinder 25 on the first pump housing 12A side is formed with an air intake and exhaust port 251 communicating with the first suction side air chamber 26A. The air intake and exhaust port 251 is connected to the air supply device 2 via the first solenoid valve 4, the first electro-pneumatic regulator 51 and the mechanical regulator 3 (see Figure 1 ). Thus, if pressurized air is supplied from the air supply device 2 to the interior of the first suction side air chamber 26A via the air intake and exhaust port 251, the first bellows 13 is extended to a predetermined extended state (hereinafter referred to as "extended state"). The extended state of the first bellows 13 may be a maximum extended state or a state immediately before reaching the maximum extended state.

[0045] The cylinder 25 on the second pump housing 12B side is formed with an air intake and exhaust port 252 communicating with the second suction side air chamber 26B. The air intake and exhaust port 252 is connected to the air supply device 2 via the second solenoid valve 5, the second electro-pneumatic regulator 52 and the mechanical regulator 3 (see Figure 1 ). Thus, if pressurized air is supplied from the air supply device 2 to the interior of the second suction side air chamber 26B via the air intake and exhaust port 252, the second bellows 14 is extended to a predetermined extended state (hereinafter referred to as "extended state"). The extended state of the second bellows 14 may be the maximum extended state or the state immediately before reaching the maximum extended state.

[0046] According to the above structure, the first pump housing 12A forming the first discharge side air chamber 21A inside, the piston body 23 forming the first suction side air chamber 26A, and the cylinder body 25 constitute the first drive part (drive part) 27 that enables the first bellows 13 to continuously extend and retract between the extended state and the contracted state.

[0047] In addition, the second pump housing 12B having the second discharge side air chamber 21B formed therein, the piston body 23 forming the second suction side air chamber 26B, and the cylinder body 25 constitute the second drive unit (drive unit) 28 for allowing the second bellows 14 to continuously extend and retract between the extended state and the contracted state.

[0048] [Detection Department]

[0049] A pair of proximity sensors 29A and 29B are mounted on the cylinder 25 of the first drive unit 27. A detection plate 30 detected by the proximity sensors 29A and 29B is mounted on the piston body 23 of the first drive unit 27. The detection plate 30 reciprocates with the piston body 23 and alternately approaches the proximity sensors 29A and 29B.

[0050] The proximity sensor 29A is configured to detect the position of the detected plate 30 when the first bellows 13 is in the mid-contraction state before reaching the contraction state. The proximity sensor 29B is configured to detect the position of the detected plate 30 when the first bellows 13 is in the extension state. If each proximity sensor 29A, 29B detects the detected plate 30, the detection signal is output to the control unit 6. The pair of proximity sensors 29A, 29B functions as a first detection unit (detection unit) 29 that detects the extension state of the first bellows 13.

[0051] A pair of proximity sensors 31A and 31B are mounted on the cylinder 25 of the second drive unit 28. A detected plate 32 detected by the proximity sensors 31A and 31B is mounted on the piston body 23 of the second drive unit 28. The detected plate 32 reciprocates with the piston body 23 and alternately approaches the proximity sensors 31A and 31B.

[0052] The proximity sensor 31A is configured to detect the position of the detected plate 32 when the second bellows 14 is in the mid-contraction state before reaching the contraction state. The proximity sensor 31B is configured to detect the position of the detected plate 32 when the second bellows 14 is in the extension state. If each proximity sensor 31A, 31B detects the detected plate 30, the detection signal is output to the control unit 6. The pair of proximity sensors 31A, 31B functions as a second detection unit (detection unit) 31 that detects the extension state of the second bellows 14.

[0053] Here, the "mid-contraction state" of the first bellows 13 (the second bellows 14) means that the contraction passing position of the first bellows 13 (the second bellows 14) is closer to the contraction end position (contracted state) than the contraction start position (extended state). More specifically, it means that the first bellows 13 (the second bellows 14) contracts to a position of 50% to 90% of the contraction length from the extended state to the contracted state.

[0054] [Pump head]

[0055] The pump head 11 is formed of a fluororesin such as PTFE or PFA. An inlet passage 34 and an outlet passage 35 for conveying a fluid are formed inside the pump head 11. The inlet passage 34 and the outlet passage 35 open on the outer peripheral surface of the pump head 11 and are connected to an inlet port and an outlet port (both not shown) provided on the outer peripheral surface.

[0056] The suction port is connected to a storage container or the like for conveying fluid, and the discharge port is connected to a conveying destination of the conveying fluid. In addition, the suction passage 34 and the discharge passage 35 respectively have a suction port 36 and a discharge port 37 that branch toward the left and right sides of the pump head 11 and open on the left and right sides of the pump head 11. Each suction port 36 and each discharge port 37 are connected to the inside of the bellows 13 and 14 via the one-way valves 15 and 16, respectively.

[0057] [Check valve]

[0058] Check valves 15 and 16 are provided at each suction port 36 and each discharge port 37 .

[0059] The one-way valve 15 (hereinafter also referred to as "suction one-way valve") installed at the suction port 36 includes: a valve housing 15a; a valve body 15b accommodated in the valve housing 15a; and a compression coil spring 15c, which preloads the valve body 15b in the valve closing direction.

[0060] The valve housing 15a is formed in a bottomed cylindrical shape. A through hole 15d is formed on the bottom wall of the valve housing 15a, which communicates with the inside of the bellows 13 and 14. The valve body 15b closes the suction port 36 (closes the valve) by the preload force of the compression coil spring 15c, and opens the suction port 36 (opens the valve) when back pressure caused by the flow of the conveying fluid accompanying the expansion and contraction of the bellows 13 and 14 acts.

[0061] Thus, the suction check valve 15 opens when the bellows 13, 14 configured therein are extended, allowing the suction of the conveying fluid from the suction passage 34 toward the direction (one direction) of the inside of the bellows 13, 14. In addition, the suction check valve 15 closes when the bellows 13, 14 configured therein are contracted, preventing the backflow of the conveying fluid from the inside of the bellows 13, 14 toward the suction passage 34 (the other direction).

[0062] The one-way valve 16 (hereinafter also referred to as "discharge one-way valve") installed in the discharge port 37 includes: a valve housing 16a; a valve body 16b accommodated in the valve housing 16a; and a compression coil spring 16c, which preloads the valve body 16b in the valve closing direction.

[0063] The valve housing 16a is formed in a bottomed cylindrical shape. A through hole 16d communicating with the inside of the bellows 13, 14 is formed in the bottom wall of the valve housing 16a. The valve body 16b closes the through hole 16d of the valve housing 16a (closes the valve) by the preload force of the compression coil spring 16c, and opens the through hole 16d of the valve housing 16a (opens the valve) when back pressure caused by the flow of the conveying fluid accompanying the expansion and contraction of the bellows 13, 14 acts.

[0064] Thus, the discharge check valve 16 opens when the bellows 13, 14 configured therein contracts, allowing the outflow of the conveying fluid from the inside of the bellows 13, 14 toward the discharge passage 35 (one direction). In addition, the discharge check valve 16 closes when the bellows 13, 14 configured therein extends, preventing the backflow of the conveying fluid from the discharge passage 35 toward the inside of the bellows 13, 14 (the other direction).

[0065] [Operation of bellows pump]

[0066] Next, refer to Figure 3 and Figure 4 The operation of the bellows pump 10 of this embodiment will be described. Figure 3 and Figure 4 The structure of the first and second bellows 13 and 14 is simplified as shown in FIG. Figure 3 As shown, when the first bellows 13 contracts and the second bellows 14 extends, the valve bodies 15b and 16b of the suction check valve 15 and the discharge check valve 16 installed on the left side of the pump head 11 are respectively moved to the right side of the valve housings 15a and 16a in the figure due to the pressure from the conveying fluid in the first bellows 13. As a result, the suction check valve 15 is closed and the discharge check valve 16 is opened, and the conveying fluid in the first bellows 13 is discharged from the discharge passage 35 to the outside of the pump.

[0067] On the other hand, the valve body 15b of the suction check valve 15 mounted on the right side of the pump head 11 in the figure moves to the right side of the valve housing 15a in the figure due to the suction action of the second bellows 14. The valve body 16b of the discharge check valve 16 mounted on the right side of the pump head 11 in the figure moves to the right side of the valve housing 16a in the figure due to the suction action of the second bellows 14 and the pressing action of the delivery fluid discharged from the first bellows 13 to the discharge passage 35. As a result, the suction check valve 15 opens and the discharge check valve 16 closes, and the delivery fluid is sucked from the suction passage 34 into the second bellows 14.

[0068] Next, if Figure 4 As shown, when the first bellows 13 is extended and the second bellows 14 is contracted, the valve bodies 15b and 16b of the suction check valve 15 and the discharge check valve 16 installed on the right side of the pump head 11 in the figure are moved to the left side of the figure of the valve housings 15a and 16a by the pressure from the conveying fluid in the second bellows 14. As a result, the suction check valve 15 is closed and the discharge check valve 16 is opened, and the conveying fluid in the second bellows 14 is discharged from the discharge passage 35 to the outside of the pump.

[0069] On the other hand, the valve body 15b of the suction check valve 15 installed on the left side of the pump head 11 in the figure moves to the left side of the valve housing 15a in the figure due to the suction action of the first bellows 13. The valve body 16b of the discharge check valve 16 installed on the left side of the pump head 11 in the figure moves to the left side of the valve housing 16a in the figure due to the suction action of the first bellows 13 and the pressing action of the conveying fluid discharged from the first bellows 13 to the discharge passage 35. As a result, the suction check valve 15 opens and the discharge check valve 16 closes, and the conveying fluid is sucked into the first bellows 13 from the suction passage 34.

[0070] By repeating the above-mentioned operation, the left and right bellows 13 and 14 can alternately suck in and discharge the transport fluid.

[0071] [Solenoid valve]

[0072] exist Figure 1 In the embodiment, the first electromagnetic valve 4 is composed of, for example, a three-way electromagnetic switching valve having a pair of solenoids 4a and 4b. Each solenoid 4a, 4b is excited based on a command signal received from the control unit 6. Thus, the first electromagnetic valve 4 is switched and controlled by the control unit 6. The first electromagnetic valve 4 switches the supply and discharge of pressurized air relative to the first discharge side air chamber 21A and the supply and discharge of pressurized air relative to the first suction side air chamber 26A by the first drive unit 27.

[0073] Specifically, when the solenoid 4a is excited, the first solenoid valve 4 switches to a state where the pressurized air is supplied to the first discharge side air chamber 21A and the pressurized air in the first suction side air chamber 26A is discharged. Also, when the solenoid 4b is excited, the first solenoid valve 4 switches to a state where the pressurized air in the first discharge side air chamber 21A is discharged and the pressurized air is supplied to the first suction side air chamber 26A.

[0074] The second electromagnetic valve 5 is composed of, for example, a three-way electromagnetic switching valve having a pair of solenoids 5a and 5b. Each solenoid 5a, 5b is excited by receiving a command signal from the control unit 6. Thus, the second electromagnetic valve 5 is switched by the control unit 6. The second electromagnetic valve 5 switches the supply and discharge of pressurized air relative to the second discharge side air chamber 21B and the supply and discharge of pressurized air relative to the second suction side air chamber 26B by the second drive unit 28.

[0075] Specifically, when the solenoid 5a is excited, the second solenoid valve 5 is switched to a state where the pressurized air is supplied to the second discharge side air chamber 21B and the pressurized air in the second suction side air chamber 26B is discharged. Also, when the solenoid 5b is excited, the second solenoid valve 5 is switched to a state where the pressurized air in the second discharge side air chamber 21B is discharged and the pressurized air is supplied to the second suction side air chamber 26B.

[0076] Furthermore, the first and second electromagnetic valves 4 and 5 of the present embodiment are constituted by three-way electromagnetic switching valves, but may be two-way electromagnetic switching valves having no neutral position.

[0077] [Electro-pneumatic regulator]

[0078] The first electro-pneumatic regulator 51 is disposed between the mechanical regulator 3 and the first solenoid valve 4. The first electro-pneumatic regulator 51 adjusts the pressure of the compressed air supplied to the first suction-side air chamber 26A of the first drive unit 27 and the pressure of the compressed air supplied to the first discharge-side air chamber 21A of the first drive unit 27, respectively.

[0079] The second electro-pneumatic regulator 52 is disposed between the mechanical regulator 3 and the second solenoid valve 5. The second electro-pneumatic regulator 52 adjusts the pressure of the compressed air supplied to the second suction-side air chamber 26B of the second drive unit 28 and the pressure of the compressed air supplied to the second discharge-side air chamber 21B of the second drive unit 28.

[0080] In addition, the electric pneumatic regulators 51 and 52 only need to adjust the air pressure of the pressurized air supplied to the suction side air chambers 26A and 26B. In addition, in the present embodiment, the electric pneumatic regulators 51 and 52 that directly adjust the air pressure are used as the fluid pressure regulating unit, but the air pressure can also be indirectly adjusted by using an air flow regulating valve that adjusts the air flow, and an instrument that adjusts the pressure or flow of a gas other than air (such as nitrogen), a liquid, etc. can also be used.

[0081] [Control Department]

[0082] exist Figure 1 and Figure 2 In the embodiment, the control unit 6 is configured to include a computer including a CPU and the like. The functions of the control unit 6 are performed by executing a control program stored in a storage device of the computer using the CPU. The control unit 6 controls the first drive unit 27, the second drive unit 28, the first electro-pneumatic regulator 51, and the second electro-pneumatic regulator 52 based on the detection results of the first detection unit 29 and the second detection unit 31. The above-mentioned control will be described in order below.

[0083] The control unit 6 performs drive control by switching the first electromagnetic valve 4 and the second electromagnetic valve 5 based on the detection results of the first detection unit 29 and the second detection unit 31 , thereby controlling the first drive unit 27 and the second drive unit 28 , respectively.

[0084] Specifically, the control unit 6 controls the drives of the first drive unit 27 and the second drive unit 28 in the following manner, i.e., based on the detection results of the first detection unit 29 and the second detection unit 31, the second bellows 14 is contracted from the extended state before the first bellows 13 is about to reach the contracted state, and the first bellows 13 is contracted from the extended state before the second bellows 14 is about to reach the contracted state.

[0085] The control unit 6 performs drive control in the above manner, so that at the timing when one of the first bellows 13 and the second bellows 14 switches from contraction to extension (from discharge to suction of the conveying fluid), the other bellows has already contracted to discharge the conveying fluid, thereby reducing the situation where the discharge pressure of the conveying fluid at the timing is greatly reduced. As a result, the pulsation on the discharge side of the bellows pump 10 can be reduced.

[0086] In the drive control, for example, if the ambient temperature decreases, the first bellows 13 and the second bellows 14 become hard due to this influence, and the extension time of the first bellows 13 and the second bellows 14 may be prolonged. In this case, the control unit 6 performs a boost control for shortening the extension time of the first bellows 13 and the second bellows 14 based on the detection results of the first detection unit 29 and the second detection unit 31. As the boost control, the control unit 6 performs a boost determination and outputs a boost command based on the determination result.

[0087] Specifically, the control unit 6 performs the following pressure increase judgment, that is, based on the detection results of the first detection unit 29 and the second detection unit 31, when the first bellows 13 (the second bellows 14) contracts to the mid-contraction state, it is judged whether the second bellows 14 (the first bellows 13) is in the middle of extension. When the result of the pressure increase judgment is affirmative (in the middle of extension), when the second bellows 14 (the first bellows 13) is extended next time, the control unit 6 outputs a pressure increase instruction to the second electro-pneumatic regulator 52 (the first electro-pneumatic regulator 51) in such a way that the air pressure of the pressurized air supplied to the second suction side air chamber 26B (the first suction side air chamber 26A) is increased. The pressure increase instruction includes the pressure increase degree of the air pressure. The pressure increase degree is preferably set to +1kPa to +50kPa (more preferably +1kPa to +20kPa).

[0088] On the other hand, in the drive control, for example, if the ambient temperature rises, the first bellows 13 and the second bellows 14 become soft due to the influence, and the extension time of the first bellows 13 and the second bellows 14 may be shortened. In this case, the control unit 6 performs a pressure reduction control for extending the extension time of the first bellows 13 and the second bellows 14 based on the detection results of the first detection unit 29 and the second detection unit 31. As the pressure reduction control, the control unit 6 performs a pressure reduction determination and outputs a pressure reduction command based on the determination result.

[0089] Specifically, the control unit 6 performs a pressure drop determination, that is, when the first bellows 13 (second bellows 14) contracts to the mid-contraction state, a pressure drop determination is performed to determine whether the extended state of the second bellows 14 (first bellows 13) continues for a predetermined time or longer, based on the detection results of the first detection unit 29 and the second detection unit 31. The predetermined time is preferably set to a value of 500 msec (preferably 10 to 200 msec), for example.

[0090] When the result of the depressurization judgment is positive (the extended state lasts for more than a predetermined time), the control unit 6 outputs a depressurization command to the second electro-pneumatic regulator 52 (first electro-pneumatic regulator 51) in such a manner that the air pressure of the pressurized air supplied to the second suction side air chamber 26B (first suction side air chamber 26A) is reduced when the second bellows 14 (first bellows 13) is extended next time. The depressurization command includes the depressurization degree of the air pressure. The depressurization degree is preferably set to -1kPa to -50kPa (more preferably -1kPa to -20kPa).

[0091] [Specific example of voltage boost control]

[0092] Figure 5 1 is a timing chart showing an example of voltage boost control performed by the control unit 6 in the drive control. Figure 1 and Figure 5 The drive control and pressure increase control executed by the control unit 6 will be described. Here, the description will be made from the state where the first bellows 13 is in the process of contraction (during discharge) and the second bellows 14 is in the process of extension (during suction).

[0093] At time point t1 when the proximity sensor 29A detects the contraction state (ON) of the first bellows 13, the control unit 6 determines whether the second bellows 14 is in the middle of extension (pressure increase determination). This determination is made based on whether the proximity sensor 31B does not detect the extension state (OFF) of the second bellows 14 at time point t1. Here, at time point t1, the proximity sensor 31B does not detect the extension state of the second bellows 14, so the control unit 6 determines that the second bellows 14 is in the middle of extension. Based on the determination result, as described later, the control unit 6 outputs a pressure increase command when the second bellows 14 is extended next time (time point t6 to time point t7).

[0094] When it is determined that the proximity sensor 31B is not turned on, the control unit 6 waits until the proximity sensor 31B turns on. Furthermore, the control unit 6 demagnetizes the solenoid 5b of the second electromagnetic valve 5 and excites the solenoid 5a at the time point t2 when the proximity sensor 31B turns on. Furthermore, when it is determined that the proximity sensor 31B turns on at the time point t1, the control unit 6 immediately demagnetizes the solenoid 5b of the second electromagnetic valve 5 and excites the solenoid 5a.

[0095] If the solenoid 5a of the second electromagnetic valve 5 is excited, the pressurized air generated by the air supply device 2 is supplied to the second discharge side air chamber 21B of the second drive unit 28 via the mechanical regulator 3, the second electro-pneumatic regulator 52 and the second electromagnetic valve 5. At this time, the control unit 6 outputs a control command to the second electro-pneumatic regulator 52 in such a way that the air pressure of the pressurized air supplied to the second discharge side air chamber 21B reaches the prescribed value P2. As a result, the second bellows 14 starts to contract from the extended state before the first bellows 13 is about to reach the contracted state.

[0096] After the second bellows 14 starts contracting, the control unit 6 determines that the first bellows 13 reaches the contracted state at time t3 after a predetermined calculation time has elapsed from time t1 when the proximity sensor 29A turns on. The control unit 6 demagnetizes the solenoid 4a of the first electromagnetic valve 4 and excites the solenoid 4b.

[0097] If the solenoid 4b of the first electromagnetic valve 4 is excited, the pressurized air generated by the air supply device 2 is supplied to the first suction side air chamber 26A of the first drive unit 27 via the mechanical regulator 3, the first electric pneumatic regulator 51, and the first electromagnetic valve 4. At this time, the control unit 6 outputs a control command to the first electric pneumatic regulator 51 in such a way that the air pressure of the pressurized air supplied to the first suction side air chamber 26A reaches the prescribed value P11. The first electric pneumatic regulator 51 adjusts the air pressure of the pressurized air supplied to the first suction side air chamber 26A to the prescribed value P11 based on the control command. As a result, the first bellows 13 starts to extend from the contracted state.

[0098] Next, the control unit 6 determines whether the first bellows 13 is in the middle of extension (pressure increase determination) at time point t4 when the proximity sensor 31A detects the contraction mid-state (ON) of the second bellows 14. This determination is made based on whether the proximity sensor 29B does not detect the extension state (OFF) of the first bellows 13 at time point t4. Here, the proximity sensor 29B does not detect the extension state of the first bellows 13 at time point t4, so the control unit 6 determines that the first bellows 13 is in the middle of extension. Based on the determination result, as described later, the control unit 6 outputs a pressure increase instruction the next time the first bellows 13 is extended (time point t8 to time point t9).

[0099] When the control unit 6 determines that the proximity sensor 29B is not turned on, the control unit 6 waits until the proximity sensor 29B turns on. Furthermore, at time t5 when the proximity sensor 29B turns on, the control unit 6 demagnetizes the solenoid 4b of the first electromagnetic valve 4 and excites the solenoid 4a. Furthermore, when the control unit 6 determines that the proximity sensor 29B turns on at time t4, the control unit 6 immediately demagnetizes the solenoid 4b of the first electromagnetic valve 4 and excites the solenoid 4a.

[0100] If the solenoid 4a of the first electromagnetic valve 4 is excited, the pressurized air generated by the air supply device 2 is supplied to the first discharge side air chamber 21A of the first drive unit 27 via the mechanical regulator 3, the first electro-pneumatic regulator 51, and the first electromagnetic valve 4. At this time, the control unit 6 outputs a control command to the first electro-pneumatic regulator 51 in such a way that the air pressure of the pressurized air supplied to the first discharge side air chamber 21A reaches the prescribed value P1. The first electro-pneumatic regulator 51 adjusts the air pressure of the pressurized air supplied to the first discharge side air chamber 21A to the prescribed value P1 based on the control command. As a result, before the second bellows 14 is about to reach the contracted state, the first bellows 13 starts to contract from the extended state.

[0101] After the first bellows 13 starts contracting, the control unit 6 determines that the second bellows 14 reaches the contracted state at time t6 after a predetermined time has passed since the proximity sensor 31A turned on. The control unit 6 demagnetizes the solenoid 5a of the second electromagnetic valve 5 and excites the solenoid 5b.

[0102] If the solenoid 5b of the second electromagnetic valve 5 is excited, the pressurized air generated by the air supply device 2 is supplied to the second suction side air chamber 26B of the second drive unit 28 via the mechanical regulator 3, the second electro-pneumatic regulator 52, and the second electromagnetic valve 5. At this time, the result of the pressure increase determination performed at the time point t1 is affirmative (determined that the proximity sensor 31B is not detected), so the control unit 6 outputs a pressure increase instruction to the second electro-pneumatic regulator 52 in such a manner that the air pressure of the pressurized air supplied to the second suction side air chamber 26B is increased.

[0103] Specifically, the control unit 6 outputs a boost command to the second electro-pneumatic regulator 52 so that the air pressure of the pressurized air supplied to the second suction side air chamber 26B reaches a value P22 higher than the value P21 of the previous time (before time point t2). The second electro-pneumatic regulator 52 adjusts the air pressure of the pressurized air supplied to the second suction side air chamber 26B to the value P22 based on the boost command. As a result, the second bellows 14 starts to extend from the contracted state. Its extension speed is faster than the extension speed of the second bellows 14 last time.

[0104] Next, the control unit 6 determines whether the second bellows 14 is in the middle of extension (pressure boost determination) at time point t7 when the proximity sensor 29A detects the contraction mid-state (ON) of the first bellows 13. Here, as described above, the extension speed of the second bellows 14 is accelerated, and the extension time of the second bellows 14 is shortened, so that the second bellows 14 reaches the extension state at time point t7. Therefore, the proximity sensor 31B detects the extension state (ON) of the second bellows 14 at time point t7, so the control unit 6 determines that the second bellows 14 is not in the middle of extension. Based on the determination result, the control unit 6 does not output a pressure boost instruction when the second bellows 14 is extended next time.

[0105] When it is determined that the proximity sensor 29B is turned on, the control unit 6 demagnetizes the solenoid 5b of the second electromagnetic valve 5 and excites the solenoid 5a. If the solenoid 5a of the second electromagnetic valve 5 is excited, the second bellows 14 starts to contract from the extended state just before the first bellows 13 reaches the contracted state (contraction midway state) as described above.

[0106] After the second bellows 14 starts the contraction action, the control unit 6 determines that the first bellows 13 reaches the contracted state at the time point t8 after the predetermined calculation time has passed since the time point t7 when the proximity sensor 29A turns on, and demagnetizes the solenoid 4a of the first electromagnetic valve 4 and excites the solenoid 4b. If the solenoid 4b of the first electromagnetic valve 4 is excited, the pressurized air generated by the air supply device 2 is supplied to the first suction side air chamber 26A of the first drive unit 27 as described above.

[0107] At this time, the result of the pressure increase determination performed at the time point t4 is affirmative (determined that the proximity sensor 29B is not detected), so the control unit 6 outputs a pressure increase command to the first electro-pneumatic regulator 51 in such a manner that the pressure of the compressed air supplied to the first intake side air chamber 26A is increased.

[0108] Specifically, the control unit 6 outputs a boost command to the first electro-pneumatic regulator 51 so that the air pressure of the pressurized air supplied to the first suction side air chamber 26A reaches a value P12 higher than the value P11 of the previous time (time point t3 to time point t5). The first electro-pneumatic regulator 51 adjusts the air pressure of the pressurized air supplied to the first suction side air chamber 26A to the value P12 based on the boost command. As a result, the first bellows 13 starts to extend from the contracted state. The extension speed is faster than the extension speed of the first bellows 13 during the previous extension action.

[0109] Next, the control unit 6 determines whether the first bellows 13 is in the middle of extension (pressure boost determination) at time point t9 when the proximity sensor 31A detects the contraction mid-state (ON) of the second bellows 14. Here, as described above, the extension speed of the first bellows 13 is accelerated, and the extension time of the first bellows 13 is shortened, so that the first bellows 13 reaches the extension state at time point t9. Therefore, at time point t9, the proximity sensor 29B detects the extension state (ON) of the first bellows 13, so the control unit 6 determines that the first bellows 13 is not in the middle of extension. Based on the determination result, the control unit 6 does not output a pressure boost instruction the next time the first bellows 13 is extended.

[0110] When the control unit 6 determines that the proximity sensor 29B is turned on, the solenoid 4b of the first electromagnetic valve 4 is demagnetized and the solenoid 4a is excited. If the solenoid 4a of the first electromagnetic valve 4 is excited, as described above, before the second bellows 14 reaches the contracted state (contraction midway state), the first bellows 13 starts to contract from the extended state.

[0111] [Specific example of voltage reduction control]

[0112] Figure 6 1 is a timing chart showing an example of voltage reduction control performed by the control unit 6 in the drive control. Figure 1 and Figure 6 The voltage reduction control performed by the control unit 6 is described below. Figure 5 Similarly, the description will be made from the state in which the first bellows 13 is in the process of contraction (during discharge) and the second bellows 14 is in the process of extension (during suction).

[0113] The control unit 6 determines whether the proximity sensor 31B detects the extension state (ON) of the second bellows 14 before the proximity sensor 29A detects the contraction midway state (ON) of the first bellows 13. Here, at time point t20 before the first bellows 13 reaches the contraction midway state, the proximity sensor 31B detects the extension state of the second bellows 14, so the control unit 6 determines that the proximity sensor 31B becomes ON.

[0114] When the control unit 6 determines that the proximity sensor 31B is turned on, and at the time point t21 when the proximity sensor 29A detects the contraction midway state of the first bellows 13, it determines whether the state has continued for a predetermined time T or longer since the time point t20 when the proximity sensor 31B detects the extension state of the second bellows 14 (pressure reduction determination). Here, the predetermined time T has passed at the time point t21, so the control unit 6 determines that the state has continued for a predetermined time T or longer since the time point t20. Based on the determination result, as described later, the control unit 6 outputs a pressure reduction instruction when the second bellows 14 is extended next time (time point t25 to time point t26).

[0115] At time t21 when the proximity sensor 29A turns on, the control unit 6 demagnetizes the solenoid 5b of the second electromagnetic valve 5 and excites the solenoid 5a. If the solenoid 5a of the second electromagnetic valve 5 is excited, as described above, before the first bellows 13 reaches the contracted state (contraction midway state), the second bellows 14 starts contraction from the extended state.

[0116] After the second bellows 14 starts the contraction action, the control unit 6 determines that the first bellows 13 reaches the contracted state at the time point t22 after the predetermined calculation time has passed since the time point t21 when the proximity sensor 29A turns on. In addition, the control unit 6 demagnetizes the solenoid 4a of the first electromagnetic valve 4 and excites the solenoid 4b. If the solenoid 4b of the first electromagnetic valve 4 is excited, the first bellows 13 starts the extension action from the contracted state as described above.

[0117] Next, the control unit 6 determines whether the proximity sensor 29B detects the extension state (ON) of the first bellows 13 before the proximity sensor 31A detects the contraction midway state (ON) of the second bellows 14. Here, at time point t23 before the second bellows 14 reaches the contraction midway state, the proximity sensor 29B detects the extension state of the first bellows 13, so the control unit 6 determines that the proximity sensor 29B becomes ON.

[0118] When the control unit 6 determines that the proximity sensor 29B is turned on, and at the time point t24 when the proximity sensor 31A detects the contraction midway state of the second bellows 14, it determines whether the proximity sensor 29B has continued for a predetermined time T or longer from the time point t23 when the first bellows 13 was detected to be in the extended state (pressure reduction determination). Here, the predetermined time T has passed at the time point t24, so the control unit 6 determines that the predetermined time T has continued from the time point t23 or longer. Based on the determination result, as described later, the control unit 6 outputs a pressure reduction instruction when the first bellows 13 is extended next time (time point t27 to time point t28).

[0119] At time t24 when the proximity sensor 31A turns on, the control unit 6 demagnetizes the solenoid 4b of the first electromagnetic valve 4 and excites the solenoid 4a. If the solenoid 4a of the first electromagnetic valve 4 is excited, as described above, before the second bellows 14 reaches the contracted state (contraction midway state), the first bellows 13 starts contracting from the extended state.

[0120] After the first bellows 13 starts the contraction action, the control unit 6 determines that the second bellows 14 reaches the contracted state at the time point t25 after the predetermined calculation time has passed since the time point t24 when the proximity sensor 31A turns on. In addition, the control unit 6 demagnetizes the solenoid 5a of the second electromagnetic valve 5 and excites the solenoid 5b. If the solenoid 5b of the second electromagnetic valve 5 is excited, the pressurized air generated by the air supply device 2 is supplied to the second suction side air chamber 26B of the second drive unit 28 as described above.

[0121] At this time, the result of the pressure reduction judgment performed at the time point t21 is affirmative (judged to have continued for more than the specified time T from the time point t20 when the proximity sensor 31B becomes ON), so the control unit 6 outputs a pressure reduction instruction to the second electric pneumatic regulator 52 in such a way that the pressure of the pressurized air supplied to the second intake side air chamber 26B is reduced.

[0122] Specifically, the control unit 6 outputs a pressure reduction command to the second electric pneumatic regulator 52 so that the air pressure of the pressurized air supplied to the second suction side air chamber 26B reaches a value P23 lower than the value P21 of the previous time (before time point t21). The second electric pneumatic regulator 52 adjusts the air pressure of the pressurized air supplied to the second suction side air chamber 26B to the value P23 based on the pressure reduction command. As a result, the second bellows 14 starts to extend from the contracted state. The extension speed is slower than the extension speed of the second bellows 14 during the previous extension action.

[0123] Next, the control unit 6 determines whether the proximity sensor 31B detects the extension state (ON) of the second bellows 14 before the proximity sensor 29A detects the contraction midway state (ON) of the first bellows 13. Here, as described above, the extension speed of the second bellows 14 slows down and the extension time of the second bellows 14 is extended, so that at the time point t26 when the first bellows 13 reaches the contraction midway state, the second bellows 14 reaches the extension state.

[0124] Therefore, before the first bellows 13 reaches the mid-contraction state, the proximity sensor 31B does not detect the extension state (OFF) of the second bellows 14, so the control unit 6 determines that the proximity sensor 31B is not turned on. Based on this determination result, at the time point t26 when the first bellows 13 reaches the mid-contraction state, the control unit 6 does not perform a pressure reduction determination, so the pressure reduction command is not output when the second bellows 14 is extended next time.

[0125] At time t26 when the proximity sensor 31B turns on, the control unit 6 demagnetizes the solenoid 5b of the second electromagnetic valve 5 and excites the solenoid 5a. If the solenoid 5a of the second electromagnetic valve 5 is excited, as described above, before the first bellows 13 reaches the contracted state (contraction midway state), the second bellows 14 starts to contract from the extended state.

[0126] After the second bellows 14 starts the contraction action, the control unit 6 determines that the first bellows 13 reaches the contracted state at the time point t27 after the predetermined calculation time has passed since the time point t26 when the proximity sensor 29A turns on. In addition, the control unit 6 demagnetizes the solenoid 4a of the first electromagnetic valve 4 and excites the solenoid 4b. If the solenoid 4b of the first electromagnetic valve 4 is excited, the pressurized air generated by the air supply device 2 is supplied to the first suction side air chamber 26A of the first drive unit 27 as described above.

[0127] At this time, the result of the pressure reduction judgment performed at the time point t24 is affirmative (judged to have continued for more than the specified time T from the time point t23 when the proximity sensor 29B becomes ON), so the control unit 6 outputs a pressure reduction instruction to the first electric pneumatic regulator 51 in such a way that the pressure of the pressurized air supplied to the first suction side air chamber 26A is reduced.

[0128] Specifically, the control unit 6 outputs a pressure reduction command to the first electric pneumatic regulator 51 so that the air pressure of the pressurized air supplied to the first suction side air chamber 26A reaches a value P13 lower than the value P11 of the previous time (time point t22 to time point t24). The first electric pneumatic regulator 51 adjusts the air pressure of the pressurized air supplied to the first suction side air chamber 26A to the value P13 based on the pressure reduction command. As a result, the first bellows 13 starts to extend from the contracted state. The extension speed is slower than the extension speed of the first bellows 13 during the previous extension action.

[0129] Next, the control unit 6 determines whether the proximity sensor 29B detects the extension state (ON) of the first bellows 13 before the proximity sensor 31A detects the contraction midway state (ON) of the second bellows 14. Here, as described above, the extension speed of the first bellows 13 slows down and the extension time of the first bellows 13 is extended, so that at the time point t28 when the second bellows 14 reaches the contraction midway state, the first bellows 13 reaches the extension state.

[0130] Therefore, before the second bellows 14 reaches the mid-contraction state, the proximity sensor 29B does not detect the extension state (OFF) of the first bellows 13, so the control unit 6 determines that the proximity sensor 29B is not turned on. Based on this determination result, at the time point t28 when the second bellows 14 reaches the mid-contraction state, the control unit 6 does not perform a pressure reduction determination, so the pressure reduction command is not output when the first bellows 13 is extended next time.

[0131] [Abnormal determination]

[0132] exist Figure 1 As described above, when the control unit 6 performs drive control, if an abnormality such as a failure occurs in the first electro-pneumatic regulator 51, the first electro-pneumatic regulator 51 maintains the air pressure adjusted immediately before the abnormality occurs. Therefore, even if the control unit 6 outputs a boost command of the boost control or a pressure reduction command of the pressure reduction control to the first electro-pneumatic regulator 51, the air pressure of the pressurized air cannot be adjusted by the first electro-pneumatic regulator 51. Therefore, the control unit 6 continuously outputs a boost command or a pressure reduction command to the first electro-pneumatic regulator 51.

[0133] When the second electro-pneumatic regulator 52 is abnormal such as a failure, the air pressure of the pressurized air cannot be adjusted by the second electro-pneumatic regulator 52. Therefore, the control unit 6 continuously outputs a pressure increase command or a pressure reduction command to the second electro-pneumatic regulator 52. The control unit 6 of this embodiment performs the following abnormality determination, that is, using this continuous output point to determine whether the first electro-pneumatic regulator 51 and the second electro-pneumatic regulator 52 are abnormal.

[0134] Specifically, the control unit 6 counts the number of times the boost control is continuously performed on the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52). Regarding the control unit 6 of the present embodiment, as the number of times the boost control is continuously performed, the number of times the determination result of the boost determination is continuously positive is counted. The control unit 6 determines whether the counted number of times exceeds the prescribed number of times. When the determination result is positive, the control unit 6 determines that the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52) is abnormal.

[0135] In addition, the control unit 6 counts the number of times the voltage reduction control is continuously performed on the first electric-pneumatic regulator 51 (the second electric-pneumatic regulator 52). Regarding the control unit 6 of the present embodiment, as the number of times the voltage reduction control is continuously performed, the number of times the determination result of the voltage reduction determination is continuously positive is counted. The control unit 6 determines whether the counted number of times exceeds the prescribed number of times. When the determination result is positive, the control unit 6 determines that the first electric-pneumatic regulator 51 (the second electric-pneumatic regulator 52) is abnormal.

[0136] As described above, with respect to the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52), when the number of times the determination result of the voltage increase determination is continuously positive and the number of times the determination result of the voltage reduction determination is continuously positive exceeds the prescribed number of times, the control unit 6 determines that the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52) is abnormal. When it is determined that the first electro-pneumatic regulator 51 or the second electro-pneumatic regulator 52 is abnormal, the control unit 6 switches the first electromagnetic valve 4 and the second electromagnetic valve 5 to stop the driving of the first drive unit 27 and the second drive unit 28.

[0137] Furthermore, the predetermined number of times when the result of the pressure increase determination is affirmative continuously and the predetermined number of times when the result of the pressure decrease determination is affirmative continuously may be set to the same value or different values.

[0138] Figure 7 1 is a flowchart showing an example of abnormality determination performed by the control unit 6 during drive control. Figure 7 The abnormality determination performed by the control unit 6 is described. In addition, the abnormality determination of the first electric-pneumatic regulator 51 and the abnormality determination of the second electric-pneumatic regulator 52 are performed in the same manner, so the abnormality determination of the first electric-pneumatic regulator 51 is described here. First, the control unit 6 sets the values ​​of the count number N and the count number M to 0 as an initial value (step ST1). The count number N is the number of times the determination result of the boost determination is continuously affirmative. The count number M is the number of times the determination result of the step-down determination is continuously affirmative.

[0139] Next, when the voltage increase determination of the first electro-pneumatic regulator 51 is performed during the drive control, if the determination result is affirmative (if "Yes" in step ST2), the control unit 6 adds 1 to the count number N and resets the count number M to 0 (step ST3).

[0140] Next, the control unit 6 determines whether the count number N exceeds the prescribed number of times (step ST4). If the count number N does not exceed the prescribed number of times (in the case of "No" in step ST4), the control unit 6 returns the process to step ST2. In this way, the process of steps ST2 to ST4 is repeated, so that the count number N gradually increases. And, if the count number N exceeds the prescribed number of times (in the case of "Yes" in step ST4), the control unit 6 determines that the first electric air regulator 51 is abnormal (step ST5) and ends the process.

[0141] On the other hand, in step ST2, when the determination result of the voltage increase determination is negative (in the case of "No" in step ST2), the control unit 6 causes the process to enter step ST6. In step ST6, when the voltage reduction determination of the first electric air regulator 51 is performed, when the determination result is positive (in the case of "Yes" in step ST6), the control unit 6 resets the count number N to 0 and increases the count number M by 1 (step ST7). In addition, when the determination result of the voltage reduction determination is negative (in the case of "No" in step ST6), the control unit 6 does not perform the process of step ST7 and returns to step ST1. In addition, in the present embodiment, the count number N is reset in step ST7, but the count number N may be reset at the time point when the determination is "No" in step ST2.

[0142] After the control unit 6 has performed the processing of step ST7, it is next determined whether the count number M exceeds the prescribed number (step ST8). If the count number M does not exceed the prescribed number (in the case of "No" in step ST8), the control unit 6 returns the processing to step ST2. In this way, the processing of steps ST2, ST6, ST7 and ST8 is repeated, so that the count number M gradually increases. Moreover, if the count number M exceeds the prescribed number (in the case of "Yes" in step ST8), the control unit 6 determines that the first electric air regulator 51 is abnormal (step ST5) and ends the processing.

[0143] [Effects of this embodiment]

[0144] According to the bellows pump device 1 of the present embodiment, the control unit 6 counts the number of times the boost control of the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52) is continuously performed, and when the counted number exceeds the prescribed number, it is determined that the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52) is abnormal. Thus, it is possible to grasp whether the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52) is abnormal with a cheap structure that does not use a pressure gauge or the like.

[0145] The control unit 6 counts the number of times the voltage reduction control of the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52) is continuously performed, and when the counted number exceeds a predetermined number, it is determined that the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52) is abnormal. Thus, it is possible to grasp whether the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52) is abnormal with a cheap structure that does not use a pressure gauge or the like.

[0146] When the number of times the voltage step-up control is continuously performed and the number of times the voltage step-down control is continuously performed exceeds a predetermined number, the control unit 6 determines that the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52) is abnormal. Therefore, whether the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52) is abnormal can be grasped regardless of whether the voltage step-up control is continuously performed or the voltage step-down control is continuously performed.

[0147] As the number of times the boost control is continuously performed, the control unit 6 counts the number of times the result of the boost determination is continuously positive. Therefore, the control unit 6 can determine that the number of times the boost control is continuously performed exceeds the prescribed number of times before outputting the boost command to the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52). As a result, it is possible to quickly grasp that an abnormality has occurred in the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52).

[0148] As the number of times the voltage reduction control is continuously performed, the control unit 6 counts the number of times the result of the voltage reduction determination is continuously positive. Therefore, the control unit 6 can determine that the number of times the voltage reduction control is continuously performed exceeds the prescribed number of times before outputting the voltage reduction command to the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52). As a result, it is possible to quickly grasp that an abnormality has occurred in the first electro-pneumatic regulator 51 (the second electro-pneumatic regulator 52).

[0149] [other]

[0150] In the above embodiment, the first detection unit 29 is composed of proximity sensors 29A and 29B, but may be composed of a displacement sensor using laser, etc. Similarly, the second detection unit 31 is composed of proximity sensors 31A and 31B, but may be composed of a displacement sensor using laser, etc.

[0151] In the above embodiment, when the first electro-pneumatic regulator 51 or the second electro-pneumatic regulator 52 is determined to be abnormal, the control unit 6 stops the driving of the first drive unit 27 and the second drive unit 28. However, in addition to or instead of this, a warning sound may be output by the notification unit.

[0152] In the above embodiment, the control unit 6 uses the number of times the result of the boost determination is positive as the number of times the boost control is continuously performed, but the number of times the boost command is continuously outputted may be used. Similarly, the control unit 6 uses the number of times the result of the boost determination is positive as the number of times the voltage reduction control is continuously performed, but the number of times the voltage reduction command is continuously outputted may be used.

[0153] It should be understood that the embodiments disclosed this time are illustrative in all aspects and are not restrictive. The scope of the present invention is indicated not by the above content but by the claims, and the purpose is to include the scope equivalent to the claims and all changes within the scope.

[0154] Description of the label

[0155] 1 Bellows pump unit

[0156] 6 Control Unit

[0157] 13.1st bellows (bellows)

[0158] 142nd bellows (bellows)

[0159] 21A 1st discharge side air chamber (discharge side fluid chamber)

[0160] 21B 2nd discharge side air chamber (discharge side fluid chamber)

[0161] 26A No. 1 suction side air chamber (suction side air chamber)

[0162] 26B 2nd suction side air chamber (suction side air chamber)

[0163] 27 1st driving unit (driving unit)

[0164] 28 second driving unit (driving unit)

[0165] 29 1st detection unit (detection unit)

[0166] 31 2nd detection unit (detection unit)

[0167] 51 No. 1 electro-pneumatic regulator (fluid pressure regulating unit)

[0168] 52 2nd electro-pneumatic regulator (fluid pressure regulating unit)

Claims

1. A bellows pump device, wherein: The bellows pump device has: A pair of bellows, which are able to expand and contract independently of each other, and draw the conveying fluid into the interior by expanding, and discharge the conveying fluid from the interior by contracting; a pair of driving parts, each having a suction side fluid chamber and a discharge side fluid chamber, wherein each of the bellows is extended to a predetermined extended state by supplying a pressurized fluid to the suction side fluid chamber, and each of the bellows is contracted to a predetermined contracted state by supplying a pressurized fluid to the discharge side fluid chamber; a pair of fluid pressure adjustment parts that adjust the fluid pressure of the pressurized fluid supplied to the suction-side fluid chamber of each of the driving parts; a pair of detection parts, which detect the expansion and contraction state of each of the bellows; as well as a control unit that controls the pair of driving units and the pair of fluid pressure adjusting units based on the detection signals of the pair of detecting units, The control unit performs drive control and voltage boost control. In the drive control, the pair of the driving parts are controlled in such a manner that the other bellows is contracted from the extended state just before one of the pair of the bellows reaches the contracted state. In the pressure-boosting control, when the one bellows contracts to a mid-contraction state just before reaching the contraction state, a pressure-boosting judgment is made to determine whether the other bellows is in the middle of extension. When the result of the pressure-boosting judgment is affirmative, a pressure-boosting instruction is output to the fluid pressure regulating unit corresponding to the driving unit that extends the other bellows in such a manner that the fluid pressure increases the next time the other bellows extends. The number of times the pressure increase control is continuously performed is counted, and when the counted number exceeds a predetermined number, it is determined that the fluid pressure regulator is abnormal.

2. A bellows pump device, wherein: The bellows pump device has: A pair of bellows, which are able to expand and contract independently of each other, and draw the conveying fluid into the interior by expanding, and discharge the conveying fluid from the interior by contracting; a pair of driving parts, each having a suction side fluid chamber and a discharge side fluid chamber, wherein each of the bellows is extended to a predetermined extended state by supplying a pressurized fluid to the suction side fluid chamber, and each of the bellows is contracted to a predetermined contracted state by supplying a pressurized fluid to the discharge side fluid chamber; a pair of fluid pressure adjustment parts that adjust the fluid pressure of the pressurized fluid supplied to the suction-side fluid chamber of each of the driving parts; a pair of detection parts, which detect the expansion and contraction state of each of the bellows; as well as a control unit that controls the pair of driving units and the pair of fluid pressure adjusting units based on the detection signals of the pair of detecting units, The control unit performs drive control and voltage reduction control. In the drive control, the pair of the driving parts are controlled in such a manner that the other bellows is contracted from the extended state just before one of the pair of the bellows reaches the contracted state. In the pressure reduction control, when the one bellows contracts to a mid-contraction state just before reaching the contraction state, a pressure reduction determination is performed to determine whether the extension state of the other bellows has continued for more than a predetermined time. When the result of the pressure reduction determination is affirmative, a pressure reduction instruction is output to the fluid pressure adjustment unit corresponding to the drive unit that extends the other bellows in such a manner that the fluid pressure is reduced the next time the other bellows is extended. The number of times the pressure reduction control is continuously performed is counted, and when the counted number exceeds a predetermined number, it is determined that the fluid pressure regulating unit is abnormal.

3. The bellows pump device according to claim 1, wherein: The control unit also performs a pressure reduction control. In the pressure reduction control, when the one bellows contracts to the mid-contraction state, a pressure reduction determination is performed to determine whether the extended state of the other bellows has continued for more than a specified time. When the result of the pressure reduction determination is affirmative, a pressure reduction instruction is output to the fluid pressure adjustment unit corresponding to the driving unit that extends the other bellows in such a way that the fluid pressure is reduced the next time the other bellows is extended. The number of times the pressure reduction control is continuously performed is counted, and when either the number of times the pressure increase control is continuously performed or the number of times the pressure reduction control is continuously performed exceeds a predetermined number, it is determined that the fluid pressure regulator is abnormal.

4. The bellows pump device according to claim 1 or 3, wherein: The control unit counts the number of times the result of the voltage increase determination is affirmative continuously as the number of times the voltage increase control is continuously performed.

5. The bellows pump device according to claim 2 or 3, wherein: The control unit counts the number of times the result of the pressure reduction determination is affirmative continuously as the number of times the pressure reduction control is continuously performed.

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