JP4624658B2 - Diaphragm pump unit using reciprocating motor - Google Patents

Description

  The present invention relates to a diaphragm pump unit using a reciprocating motor used for a metering injection pump, a vacuum pump, or the like.

  In recent years, diaphragm pumps have been used in various fields such as injection of chemicals (see Patent Document 1). In such a diaphragm pump, it is desired that the mixing tank for uniformly injecting the chemical solution is not required, the entire unit is downsized, and the injection ratio does not change even when the feed water flow rate changes.

  A conventional diaphragm pump uses a solenoid as shown in FIG. 8 as a drive source. In FIG. 8, a magnetic field is generated by passing a current through a coil 12 housed in a coil case 11, and the shaft 14 attached to the plunger 13 moves in the attracting direction. When the shaft 14 moves in the suction direction, the diaphragm interlocked with the shaft 14 also moves in the suction direction. For this reason, a suction process is performed in which the chemical solution is sucked into a pump chamber (not shown) of the diaphragm pump.

By the way, the solenoid used as a drive source of the diaphragm pump is on / off controlled by a control signal from a control unit (not shown). That is, on / off control is performed by a rectangular wave signal. The control unit controls the solenoid on and off according to the flow rate flowing through the diaphragm pump line detected by the flow rate sensor. Here, the flow rate sensor outputs a number of pulses corresponding to the flow rate flowing through the pipeline to the control unit. The controller measures the number of pulses and controls the solenoid on / off according to the measured number of pulses.
JP-A-8-68379

  However, in the case of the method of driving the diaphragm pump with a solenoid, the solenoid is controlled to be turned on and off, so that it is impossible in principle to change the reciprocating speed at which the shaft 14 makes one stroke. In the discharge step of discharging the chemical solution from the pump chamber, the shaft 14 advances momentarily and pushes the diaphragm to discharge the chemical solution from the pump chamber.

  However, in this method, the non-injection time is long and uniform injection is not performed. Furthermore, when the chemical injection is for sterilization purposes, there is a problem of hygiene, so it has been dealt with by adding a mixing tank. When the number of mixing tanks is increased in this way, there is a problem that the cost is increased and the size of the unit is increased.

  Further, the suction step of sucking the chemical solution from the chemical solution tank by retracting the shaft 14 and pulling the diaphragm is a state in which no chemical solution is supplied when viewed from the pipeline side. In particular, when the flow rate through the pipeline is small and the amount of the chemical solution is small, the number of strokes per certain time of the solenoid is reduced, so the non-injection time of the chemical solution is lengthened, which has been a problem that hinders uniform injection. .

  Moreover, when the flow volume which flows through a pipe line is small and the injection amount which requires is small, the intermittent operation in which an instantaneous discharge and a suction process are repeated is performed. Therefore, the pulse measurement time of the flow rate sensor is set to a very long time (for example, 60 seconds) based on the minimum number of strokes per fixed time. For this reason, when the flow rate fluctuates rapidly, the number of strokes per fixed time cannot be changed quickly, and there is a risk that the injection amount of the chemical solution is insufficient or excessive.

  In the case of a method of driving the diaphragm pump with a solenoid, a square wave is output as a drive signal from the control unit to the diaphragm pump. In this way, when the waveform of the drive signal is a square wave, the reciprocating speed of the shaft 14 increases, so that high noise is generated due to the impact when the solenoid stator and the mover or the diaphragm shaft 14 collide with the motor frame. There was a problem that occurred.

  The present invention has been made in view of the above points, and an object thereof is a reciprocating motor capable of performing uniform injection even when the flow rate flowing through the pipeline is small and the injection amount is small, and in which noise is low. It is in providing the diaphragm pump unit which used this.

The invention according to claim 1 is an output shaft provided with a notch, two stators facing the side surfaces of the output shaft, coils wound around the stators, and the output of the stator. A reciprocating motor having permanent magnets magnetized on surfaces facing the shaft, and a part of the motor projecting into the notch, thereby making it possible to regulate the stroke length of the reciprocating motion of the output shaft. A pump having a formed stopper, a pump chamber partially opened, a suction port continuous with the pump chamber via a suction pipe, and a discharge port continuous with the pump chamber via a discharge pipe A casing, a diaphragm provided at a tip of the output shaft so as to be capable of reciprocating with the reciprocating motion of the output shaft, and disposed within the pump casing; On one end A piston member provided via the diaphragm and a flow rate sensor that is provided in the discharge pipe and detects the flow rate of the liquid flowing through the discharge pipe by being discharged by the reciprocating motion of the diaphragm and the piston member. And by causing a sine wave current or a triangular wave current to flow through the coil, the output shaft is reciprocated and the operating frequency of the sine wave current or the triangular wave current according to the flow rate of the liquid detected by the flow rate sensor. The reciprocating motor has a stroke length that the output shaft moves is proportional to the magnitude of the sine wave current or the triangular wave current flowing through the coil, The speed of reciprocation of the output shaft is proportional to the operating frequency of the sine wave current or the triangular wave current flowing through the coil.

According to a second aspect of the invention, a diaphragm pump unit using a reciprocating motor according to claim 1, wherein the OPERATION frequency flows in the coil in the suction process of the liquid by the diaphragm and the piston member The maximum operating frequency at which the liquid can be sucked into the pump chamber by the diaphragm and the piston member .

A third aspect of the present invention is the diaphragm pump unit using the reciprocating motor according to the first aspect, wherein the flow rate sensor is configured to output a pulse number proportional to the flow rate of the liquid flowing in the pipe line. The control unit counts the number of pulses output from the flow sensor at regular intervals, and obtains the operating frequency by multiplying the counted number of pulses by a first coefficient , whereby the coil and wherein the benzalkonium control the OPERATION frequency of the sinusoidal current or the triangular wave current flowing through the.

According to a fourth aspect of the present invention, there is provided a diaphragm pump unit using the reciprocating motor according to the third aspect, wherein the control unit is configured to display and set a second coefficient. The operating frequency is obtained by multiplying the coefficient of 2 and the second coefficient.

Since the position of the sheet Yafuto moves in response to a sinusoidal waveform or a triangular waveform, for reciprocating speed of the shaft immediately before impinging on a stopper or the like that defines the stroke length of the diaphragm pump is reduced, reducing the collision noise Can do.

Since control section was to control the operating frequency of the sine wave current or triangle wave current flows through the reciprocating motor in accordance with the flow through the conduit of the diaphragm pump, which is detected by the flow sensor, or the position of the shaft sinusoidal Move according to the triangular waveform. For this reason, even when the flow rate flowing through the pipeline is small and the flow rate is small, a fixed amount can be injected with high accuracy.

Predetermined time (e.g., 1 second) which can follow the abrupt deceleration rate change was a pulse measurement time of the flow rate sensor, a diaphragm pump is implanted in accordance with the number of pulses output from the flow sensor for each the predetermined time solution Multiply the number of pulses output from the flow sensor by the first coefficient to obtain the operating frequency so as to maintain a constant concentration, and follow the rapid flow rate change by changing the operating frequency of the reciprocating motor. be able to.

Shi Yafuto is pulled is the diaphragm retracts in the suction process for sucking the drug solution from such chemical tank, the operating frequency of the sine wave or a triangular wave, a suction operable maximum frequency is restricted by the check valve or the like of the pump As a result, the non-injection time during which no chemical solution is supplied can be minimized, so that a more uniform liquid amount can be injected.

Second coefficient is displayed and can be set to control section, by adjusting the stroke speed of the diaphragm pump by calculating the operation frequency by multiplying the first coefficient and the second coefficient to the pulse number of the flow sensor Therefore, the user can easily adjust the chemical concentration by changing the second coefficient.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a diaphragm pump using a reciprocating pump. In the figure, 21 is a cylindrical pump casing. One end of the pump casing 21 is provided with a suction port 22 for sucking liquid such as a chemical solution, and the other end is provided with a discharge port 23 for discharging liquid, and a pump chamber 24 is formed from the side surface to the vicinity of the central axis. Has been.

  A suction line 25 is formed between the suction port 22 and the pump chamber 24, and a discharge line 26 is formed between the pump chamber 24 and the discharge port 23.

  Furthermore, a check valve 27 that enables suction of liquid only from the suction port 22 toward the pump chamber 24 is interposed in the suction pipe line 25. Further, a check valve 28 that enables discharge of liquid from the pump chamber 24 only in the direction of the discharge port 23 is interposed in the discharge pipe line 26.

  Reference numeral 31 denotes a motor frame of the reciprocating motor 30. A cylindrical motor cover 32 is attached to the motor frame 31.

  Furthermore, one end of four support pins 33a to 33d is riveted to the motor frame 31 in the circumferential direction. In FIG. 1, only 33a and 33c are shown.

  A stopper 41, a disc-shaped plate spring 42, a stator 43, and a disc-shaped plate spring 44, which will be described in detail later with reference to FIG. 2, are fixed to the support pin 33a from the motor frame 31 side.

  Furthermore, the stopper 41, the disk-shaped leaf spring 42, the stator 45, and the leaf spring 44 are also fixed to the support pin 33c.

  The shaft (output shaft) 51 of the reciprocating motor 30 is supported at both ends by leaf springs 42 and 44.

  A support member 53 is fixed to one end side of the shaft 51. The support member 53 is formed with a notch 52 having a constant width in which a part of the stopper 41 is projected and retracted.

  Furthermore, the one end side of the shaft 51 has a small-diameter portion 51a having a small diameter. A cylindrical piston member 62 is attached to the small diameter portion 51 a via a bellows 61.

  A first coil 71 is wound around the stator 43, and a second coil 72 is wound around the stator 45.

  Further, a permanent magnet 73 is magnetized on the side surface of the stator 43 facing the shaft 51 in the axial direction of the shaft 51, and the side surface of the stator 45 facing the shaft 51 in the axial direction of the shaft 51. A permanent magnet 74 is magnetized. Here, the polarities of the permanent magnets 73 and 74 are the same.

  The first coil 71 and the second coil 72 are connected in series as shown in FIG. 4, and the sine wave current I (shown in FIG. 3) flowing through the first coil 71 and the second coil 72 is controlled. It is controlled by a drive signal from the unit 81.

  Further, the winding direction is determined so that the direction of the magnetic field generated by the current I flowing through the first coil 71 and the second coil 72 is the same.

  Accordingly, when the current flows through the first coil 71 and the second coil 72, the current direction periodically changes. Therefore, the permanent magnet 73 is generated by the magnetic field generated by the current flowing through the first coil 71 and the second coil 72. And 74 magnetic fields are increased or decreased.

  As a result, the shaft 51 reciprocates periodically in the axial direction. By reciprocating the shaft 51, the diaphragm 61 also reciprocates, and the piston member 62 also reciprocates.

  The magnitude of the reciprocating motion of the diaphragm 61, that is, the stroke length ΔL is determined by the magnitude of the current I.

  In FIG. 1, the end surface of the piston member 62 on the pump chamber 24 side has a step, but the upper half (indicated by reference numeral 62 a) indicates the end position of the discharge process for discharging the liquid in the pump chamber 24, and the lower side Half (indicated by reference numeral 62 b) indicates the end position of the suction step for sucking the liquid into the pump chamber 24.

  Reference numeral 91 denotes a connector. A connector 92 connected to a control line 92 from the control unit 81 is connected to the connector 91. Thereby, an electric circuit as shown in FIG. 3 is formed.

  A detection output of a flow rate sensor 82 installed in the discharge pipe 26 of the diaphragm pump is input to the control unit 81. The flow rate sensor 82 outputs one pulse as a flow rate pulse every time a constant flowing chemical solution flows through the discharge conduit 26. The control unit 81 counts the number of flow rate pulses output from the flow rate sensor 82 at regular time intervals (for example, 1 second).

  The control unit 81 is provided with a digital display unit 83 for displaying an adjustment value, a change button 84 for changing the adjustment value, and a setting switch 85 for setting the adjustment value displayed on the digital display unit 83. Here, every time the change button 84 is operated, the adjustment value displayed on the digital display 83 is cyclically displayed.

  As shown in FIG. 2, the control unit 81 includes a table 86 that stores a second coefficient corresponding to the adjustment value set in the digital display body 83. For example, when the adjustment value set on the digital display 83 is “0”, “100%” is set as the second coefficient, and when the adjustment value is “9”, “90%” is set as the second coefficient. Is done.

  The control unit 81 calculates the operation frequency by counting the number of pulses of the flow rate pulse output from the flow rate sensor 82 at regular time intervals (1 second) and multiplying the number of pulses by a first coefficient that is a predetermined coefficient. Seeking in. The first coefficient is set in a predetermined memory area in the control unit 81.

  When an adjustment value is set by the digital display 83, the second coefficient corresponding to this adjustment value is acquired from the table 86. Then, the control unit 81 counts the number of flow rate pulses output from the flow rate sensor 82 and multiplies the number of pulses by the first coefficient and the second coefficient to obtain the operation frequency by calculation.

  Then, the control unit 81 drives the reciprocating motor 30 at the operation frequency thus obtained by calculation. At this time, the current value I flowing through the reciprocating motor 30 is kept constant so that the stroke length ΔL is constant.

  Next, the operation will be described. A sine wave current I as shown in FIG. 4 flows through the first coil 71 and the second coil 72 by the control of the drive signal from the control unit 81.

  As a result, the diaphragm 61 reciprocates with a stroke length ΔL corresponding to the magnitude of the sine wave current I. As a result, the piston member 62 reciprocates in the pump chamber 24 with a stroke length ΔL. If the sine wave current I flows through the first coil 71 and the second coil 72, the amount of liquid discharged while the pump member 62 reciprocates once is constant.

  That is, the piston member 62 reciprocates between the end position 62b of the suction process for sucking the liquid into the pump chamber 24 and the end position 62a of the discharge process for discharging the liquid in the pump chamber 24.

  Accordingly, the liquid sucked into the pump chamber 24 in the suction process is discharged through the discharge port 23 in the discharge process. At this time, the discharge amount of the liquid discharged from the discharge port 23 is determined by the stroke length ΔL.

  This stroke length ΔL is determined by the magnitude of the sine wave current I flowing through the first coil 71 and the second coil 72.

  At this time, the speed at which the piston member 62 reciprocates in the pump chamber 24 is proportional to the operating frequency.

  Thus, when the frequency of the sine wave current I is changed, the number of times the piston member 62 reciprocates with the stroke length ΔL per unit time changes.

  Thereby, the amount of liquid ejected per unit time is varied.

  Incidentally, the control unit 81 obtains the operating frequency of the reciprocating motor 30 by multiplying the flow rate pulse detected by the flow rate sensor 82 by the first coefficient.

  Further, the second coefficient corresponding to the adjustment value displayed on the digital display 83 is obtained with reference to the table 86.

  When the adjustment value is set by the digital display 83 as described above, the control unit 81 multiplies the flow rate pulse detected by the flow rate sensor 82 by the first coefficient and the second coefficient, and the reciprocating motor 30. The operating frequency is being calculated.

  FIG. 4 shows a sine waveform flowing through the reciprocating motor 30 when the diaphragm pump is driven at a low speed when the amount of water is small, and FIG. 4 shows a sine flowing through the reciprocating motor 30 when the diaphragm pump is driven at a high speed when the flow rate is large. The wave waveform is shown.

  4 and 5, the waveform indicated by a broken line indicates a conventional solenoid type driving waveform.

  As described above, since the drive waveform of the reciprocating motor 30 is a sine waveform, the position of the shaft 51 moves in accordance with the sine waveform, so that the position immediately before colliding with a stopper or the like defining the stroke length of the diaphragm pump. Since the reciprocating speed of the shaft 51 is reduced, the collision noise can be reduced.

  Since the controller 81 controls the operating frequency of the sine wave current flowing in the reciprocating motor 30 in accordance with the number of flow pulses detected by the flow sensor 82, that is, the flow rate flowing in the pipe line of the diaphragm pump, The position 51 moves according to the sine waveform. For this reason, even when the flow rate flowing through the pipeline is small and the flow rate is small, a fixed amount can be injected with high accuracy. That is, as shown in FIG. 4, the operating frequency is small when the flow rate is small. In the discharge step a, the flow rate is discharged through the discharge pipe 26, and the length b1 of the suction step can be made longer than the length b2 of the conventional solenoid system. Thereby, the non-injection time of a chemical | medical solution can be shortened compared with the conventional solenoid system. Therefore, uniform injection can be performed. In FIG. 4, a waveform indicated by a broken line indicates a rectangular ON signal during discharge in the conventional solenoid system, and c indicates a measurement time for measuring the output of the flow sensor in the conventional solenoid system. In the present invention, detection is performed every second.

  In the case of a large flow rate with a large number of flow rate pulses detected by the flow rate sensor 82, the control unit 81 has a higher operating frequency than that in FIG. 4 as shown in FIG. As a result, a large amount of chemical liquid can be discharged through the discharge pipe 26.

  Incidentally, when there is a steep flow rate change, for example, when there is a small flow rate to a large flow rate at time t1, the operating frequency of the reciprocating motor 30 changes steeply as shown in FIG. The control unit 81 sets a fixed time (for example, 1 second) as the pulse measurement time of the flow sensor, and the solution injected by the diaphragm pump has a constant concentration according to the number of pulses output from the flow sensor 82 every fixed time. Further, by multiplying the number of pulses output from the flow rate sensor 82 by the first coefficient to obtain the operating frequency and changing the operating frequency of the reciprocating motor 30, it is possible to follow a rapid flow rate change.

  However, since the measurement time of the conventional solenoid system is c, it cannot be handled when the flow rate changes sharply within the measurement time c.

  Further, as shown in FIG. 7, in the suction process in which the shaft is retracted and the diaphragm is drawn to suck the chemical liquid from a chemical tank or the like, a suction operation in which the sine wave operating frequency is regulated by a pump check valve or the like is possible. When the maximum frequency is set, the non-injection time during which no chemical solution is supplied can be minimized, so that a more uniform liquid amount can be injected. At this time, the operation frequency of the sine wave in the discharge process is to count the flow rate pulse output from the flow rate sensor 82 and multiply the number of pulses by the first coefficient or the second coefficient as necessary. Is required. In this way, as shown in FIG. 7, the operation frequency of the discharge process at a small flow rate is reduced, and the operation frequency of the suction process is set to the maximum frequency at which the suction operation can be performed. It can be made shorter than the non-injection time y. By doing so, a more uniform liquid amount can be injected.

  Further, the second coefficient can be displayed and set on the control unit 81, and the stroke speed of the diaphragm pump is calculated by calculating the operation frequency by multiplying the number of pulses of the flow sensor 81 by the first coefficient and the second coefficient. Since it can be adjusted, the user can easily adjust the chemical concentration by changing the second coefficient.

  In the above-described embodiment, the control unit 81 controls the sine wave to flow through the reciprocating motor 30, but may control the sine wave to flow.

Sectional drawing of the diaphragm pump using the reciprocating motor which concerns on one embodiment of this invention. The figure which shows the content of the table set to the control part which concerns on the same embodiment. The figure which shows the connection relation of the control part which concerns on the same embodiment, and a 1st coil and a 2nd coil. The wave form diagram which drives the diaphragm pump which concerns on the embodiment at low speed at the time of small flow volume. The wave form diagram which drives the diaphragm pump which concerns on the embodiment at high speed at the time of a large flow rate. The wave form diagram which switches the diaphragm pump which concerns on the embodiment from low speed to high speed at the time of a rapid flow rate change. The figure which shows the waveform which drives the diaphragm pump which concerns on the same embodiment by the maximum possible operation frequency in a suction process. Sectional drawing of the principal part of the diaphragm pump using the conventional solenoid.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 ... Pump casing, 41 ... Stopper, 43 ... Stator, 51 ... Shaft 61 ... Diaphragm, 81 ... Control part, 82 ... Flow sensor.

Claims (4)

An output shaft provided with a notch, two stators facing the side surfaces of the output shaft, coils wound around the stators, and a surface of the stator facing the output shaft, respectively. A reciprocating motor comprising a magnetized permanent magnet;
A stopper that is formed so as to be able to regulate the stroke length of the reciprocating motion of the output shaft, by partly projecting into the notch,
A pump chamber in which a part of the pump chamber is opened, a suction port continuous with the pump chamber through a suction pipe, and a pump casing in which a discharge port continuous with the pump chamber through a discharge pipe is formed;
A diaphragm that is provided at the tip of the output shaft so as to be capable of reciprocating with the reciprocating motion of the output shaft,
A piston member disposed in the pump casing and provided on one end side of the output shaft via the diaphragm;
A flow rate sensor which is provided in the discharge pipe and detects the flow rate of the liquid flowing through the discharge pipe by being discharged by reciprocation of the diaphragm and the piston member;
By passing a sine wave current or a triangular wave current through the coil, the output shaft is reciprocated and the operating frequency of the sine wave current or the triangular wave current is changed according to the flow rate of the liquid detected by the flow sensor. A control unit formed possible;
With
In the reciprocating motor, the stroke length that the output shaft moves is proportional to the magnitude of the sine wave current or the triangular wave current flowing through the coil, and the reciprocating speed of the output shaft flows through the coil. A diaphragm pump unit using a reciprocating motor characterized by being proportional to the operating frequency of the sine wave current or the triangular wave current.   The operating frequency that is passed through the coil in the step of sucking the liquid by the diaphragm and the piston member is a maximum operating frequency at which the liquid can be sucked into the pump chamber by the diaphragm and the piston member. A diaphragm pump unit using the reciprocating motor according to claim 1. The flow sensor is formed to be capable of outputting a pulse number proportional to the flow rate of the liquid flowing in the pipe line,
The control unit counts the number of pulses output from the flow rate sensor at regular intervals, and multiplies the counted number of pulses by a first coefficient to obtain the operating frequency, thereby causing the coil to flow. 2. A diaphragm pump unit using a reciprocating motor according to claim 1, wherein an operating frequency of the sine wave current or the triangular wave current is controlled.   4. The control unit is configured to be able to display and set a second coefficient, and obtains the operating frequency by multiplying the first coefficient and the second coefficient. Diaphragm pump unit using a reciprocating motor.

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