JP5779372B2 - Diaphragm pump, control method of diaphragm pump, and sterilizer - Google Patents

Description

  The present invention relates to a diaphragm pump, a diaphragm pump control method, and a sterilizer.

  When using well water as domestic water or drinking water, ferromanganese ions and the like contained in well water are removed by a filtration tank and sterilized.

  The filter tank is filled with ceramic filter sand or a filter material for removing manganese with the surface coated with manganese dioxide. A sterilizer for injecting sodium hypochlorite as a sterilizing / oxidizing agent is installed on the primary side of the filtration tank.

  The sterilizer includes a chemical tank for storing sodium hypochlorite and a flow rate detection unit for proportional flow rate injection having a rotor blade with a magnet for detecting the filtration flow rate. Furthermore, the sterilizer includes a diaphragm pump that injects a certain amount of sodium hypochlorite proportional to the filtration flow rate, a connecting pipe through which well water passes, and a chemical solution injection unit.

  The diaphragm pump used in the sterilizer is small and easy to incorporate in the apparatus, and its pump characteristics are suitable for precision injection. Further, since diaphragm pumps require a reciprocating operation to drive the diaphragm, electromagnetic solenoids that are inexpensive and simple in structure are often used as actuators.

  The solenoid-driven diaphragm pump pushes the plunger against the injection pressure by supplying a current to the solenoid coil when discharging the chemical solution. When this extrusion is completed, the metal plunger collides with the metal fixed iron core, generating unpleasant collision noise. This collision sound is greatly affected by the surrounding environment. For example, in a machine room in which a large pump or the like is installed, or when the flow rate used is large and the number of strokes per hour is large, the magnitude and number of collision sounds increase, resulting in discomfort.

  On the other hand, the product specification of the diaphragm pump has the maximum pressure that can be injected, and the maximum compression force of the return spring and the elastic force when the diaphragm is pushed out are added to the maximum pressure multiplied by the pressure receiving area of the diaphragm. It is necessary to flow a current that generates the thrust to the solenoid. In addition, it is necessary to set a sufficient energizing current and energizing time in consideration of product variations in solenoid coil resistance value, resistance value increase due to temperature rise, and power supply voltage fluctuation. For this reason, the moving speed immediately before the plunger collides with the fixed iron core becomes excessive, which causes a loud collision sound.

  As a characteristic of the solenoid, when a constant voltage is applied, the thrust increases in inverse proportion to the stroke distance when the plunger starts to move and the distance from the fixed iron core decreases. In addition, the current value increases due to the decrease in inductance, the thrust further increases, and the impact sound on the fixed iron core becomes extremely loud.

  In order to mitigate the impact sound on the fixed iron core, a product called rubber silencer, which has an elastic body (= shock absorbing material) sandwiched between the fixed iron core and the plunger, is also manufactured. However, it is not possible to eliminate the collision sound that the metal plunger and the fixed iron core collide. In addition, as a characteristic of the solenoid, since the generated thrust is the smallest when the plunger is farthest from the fixed iron core, the position just before extrusion including the stroke distance is further increased. Thus, the thrust is reduced, the required current is increased, and the temperature is increased, and the permanent set of the elastic body is increased, so that the stroke distance due to the deformation of the elastic body varies.

JP 2007-177691 A

  The above-described technique has the following problems. The solenoid-driven diaphragm pump changes the appropriate energization current depending on various conditions such as temperature, piping pressure, and other surrounding environments and equipment variations. However, the above technology generates a large thrust in consideration of the temperature rise of the solenoid coil. The solenoid to be used is selected, and the rated energization current is set to be high in anticipation of resistance increase and current decrease due to temperature rise. Therefore, the cost of the solenoid itself cannot be avoided, and since a high energization current is applied to the solenoid coil even during cold weather or low stroke operation, wasteful power is consumed and the noise at the time of collision of the fixed core increases. There is a tendency.

  Therefore, an object of the present invention is to provide a diaphragm pump, a diaphragm pump control method, and a sterilizer that can set an appropriate energization current corresponding to the conditions of each device.

A control method for a diaphragm pump according to an aspect of the present invention is a control method for a solenoid-driven diaphragm pump that injects a liquid, and the energization current of the diaphragm pump increases from the start of energization, and the first local maximum point After that, the inflection point occurrence time which is the elapsed time from the start of energization at the time when the inflection point which starts to decrease and then increases again is detected, and the detected inflection point occurrence time is the reference inflection point. If the applied time is longer than the reference voltage value by increasing the applied voltage, the energizing current is increased, and the detected inflection point occurrence time is shorter than the reference inflection point occurrence time by a certain value or more. In this case, the energizing current is reduced by reducing the applied voltage with respect to the reference voltage value.

A diaphragm pump according to another aspect of the present invention is a solenoid-driven diaphragm pump for injecting a liquid, and the energization current of the diaphragm pump increases from the start of energization and decreases after the first maximum point. The inflection point occurrence time that is the elapsed time from the start of energization when the inflection point that starts to increase again occurs is detected, and the detected inflection point occurrence time is longer than the reference inflection point occurrence time. When it is longer than a certain value, the applied current is increased by increasing the applied voltage above the reference voltage value. When the detected inflection point occurrence time is shorter than the reference inflection point occurrence time, it is the reference The energizing current is reduced by reducing the applied voltage rather than the voltage value .

  A sterilizer according to another aspect of the present invention includes the diaphragm pump.

  According to the present invention, it is possible to set an appropriate energization current corresponding to the condition of each device.

Explanatory drawing which shows the diaphragm pump concerning one Embodiment of this invention. Explanatory drawing which shows the same diaphragm pump. Explanatory drawing which shows the structure of the control apparatus of the diaphragm pump. The flowchart which shows the control method of the same diaphragm pump. The graph explaining the current waveform of the same diaphragm pump. The graph which shows the current waveform in the 1st state of the same diaphragm pump. The graph which shows the current waveform in the 2nd state of the same diaphragm pump. The graph which shows the current waveform in the 3rd state of the same diaphragm pump.

  Hereinafter, a solenoid-driven diaphragm pump according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4.

  The diaphragm pump 10 is shown in FIG.1 and FIG.2. FIG. 1 shows a state where the diaphragm 18 is moving backward, and FIG. 2 shows a state where the diaphragm 18 is moving forward.

  The diaphragm pump 10 includes a case body 12, a solenoid coil 14 that is a cylindrical coil, a plunger 16, a diaphragm 18, a back cover 20, an adjustment screw 22 screwed into the back cover 20, a pump body 24, and the like. It is configured. In the following description, the pump body 24 side is assumed to be the front and the reverse is assumed to be the rear as viewed from the solenoid coil 14 side.

  The case body 12 has a cylindrical shape and is formed of a metal material or a resin material. The solenoid coil 14 is fixed inside the case main body 12 with screws 26. A back cover 20 is fixed to the back of the case body 12 with screws 28. A pump main body 24 is liquid-tightly attached to the front of the case main body 12 with screws 30 or the like.

  The solenoid coil 14 is a cylindrical coil, and a plunger 16 is provided at the center so as to be movable in the front-rear direction. A power line 86 from the control device 60 is connected to the input terminal of the solenoid coil 14.

  The plunger 16 includes a shaft portion 32, a movable iron core 34 attached to the shaft portion 32, an auxiliary magnetic pole plate 36 provided behind the shaft portion 32, and the like. The shaft portion 32 is slidably provided through a bearing 17 in a hole 15 provided in the center of the solenoid coil 14. The movable iron core 34 is integrally fixed to the shaft portion 32 and is slidably accommodated in a recess 40 formed behind the solenoid coil 14. When the plunger 16 advances to a predetermined position, the movable iron core 34 contacts the rear surface 46 of the solenoid coil 14 and stops the advance of the plunger 16.

  A return spring 44 is provided between the movable iron core 34 and the solenoid coil 14. The return spring 44 is a coil spring and urges the plunger 16 rearward with a predetermined spring force.

  The auxiliary magnetic pole plate 36 is a metal plate and is integrally attached to the shaft portion 32. The auxiliary magnetic pole plate 36 forms a magnetic circuit when the plunger 16 is advanced, and increases the thrust of the plunger 16. When the plunger 16 moves backward, the auxiliary magnetic pole plate 36 contacts the front end portion 52 of the adjustment screw 22 and stops the plunger 16 from moving backward. The adjustment screw 22 is assembled to the back cover 20 with a screw, and the front end portion 52 can be set at an arbitrary position by turning the adjustment screw 22 left and right with respect to the back cover 20.

  The diaphragm 18 is plate-shaped and made of an elastic material, and is attached so as to face a pumping chamber 54 formed in the pump body 24. The center portion of the diaphragm 18 is assembled to the tip end of the shaft portion 32, and the outer peripheral portion is liquid-tightly fixed between the front end edge of the case body 12 and the pump body 24. The shape and material of the diaphragm 18 are not particularly limited.

  The pump main body 24 is formed with the above-described pressure feeding chamber 54 substantially at the center, and an inflow port 96 is provided in the lower part of the drawing, and an outflow port 98 is provided in the upper part of the drawing. An inflow one-way ball valve 56 is provided on the inlet 96 side of the pumping chamber 54, and an outflow one-way ball valve 58 is provided on the outlet 98 side. A liquid feed pipe 102 from the storage tank 100 (see FIG. 3) is connected to the inlet 96 of the pump body 24 by a socket 104. A liquid supply pipe 106 is connected to the outlet 98 of the pump body 24 by a socket 108.

  The other end of the liquid feeding pipe 106 extends to the mixing portion of the water flow pipe 110 (see FIG. 3). The mixing unit causes a liquid, for example, a sterilizing agent sent from the liquid feeding pipe 106 to flow out into a fluid flowing in the water passage 110, for example, well water, and mix the sterilizing agent into the well water. The water flow pipe 110 on the downstream side of the mixing section is connected to a household faucet or the like via a filtration device or the like, for example. The diaphragm pump 10 is connected to a control device 60 shown in FIG.

  As shown in FIG. 3, the control device 60 includes a power supply device 62, a storage device 64, an input device 66, a display device 68, a control unit 70, a control unit 72, and the like.

  The power supply device 62 includes a rectification / smoothing circuit 74, a variable DC voltage generation unit 76, a control power supply unit 78, and the like. A commercial power supply 200 is connected to the power supply device 62. When the main switch of the diaphragm pump 10 is turned on, power is sent from the commercial power source 200 to the rectifying / smoothing circuit 74.

  The rectification / smoothing circuit 74 includes, for example, a diode bridge and a capacitor, and rectifies and smoothes the power from the commercial power source 200. The rectifying / smoothing circuit 74 is connected to the variable DC voltage generating unit 76 through the power line 90 and the control power supply unit 78 through the power line 92, and the power rectified and smoothed by the rectifying / smoothing circuit 74 passes through the power line 90. The voltage is sent to the variable DC voltage generator 76 and to the control power source 78 through the power line 92.

  The variable DC voltage generation unit 76 is, for example, an FET switching circuit, and is connected to the control unit 70 through the power line 94 and to the control unit 72 through the signal line 130. When receiving the power rectified by the rectifying / smoothing circuit 74, the variable DC voltage generating unit 76 generates a DC voltage having a predetermined voltage in accordance with an instruction from the control unit 72. The generated voltage is applied to the control unit 70.

  The control power supply unit 78 is connected to the control unit 72 via the power line 132, converts the power from the rectification / smoothing circuit 74 into a voltage necessary for the control unit 72, and supplies stable power to the control unit 72.

  In addition to the power line 132 from the control power supply unit 78, the control unit 72 is connected to the storage device 64 through the signal line 65, the input device 66 through the signal line 67, and the display device 68 through the signal line 69.

  The control unit 72 is connected to signal lines 120 and 122 from a water level sensor 112 of the storage tank 100 and a flow rate sensor 114 provided in the water conduit 110.

  The water level sensor 112 measures the amount of medicine stored in the storage tank 100 and sends the value to the control unit 72. The flow sensor 114 measures the flow rate per unit time of the fluid flowing through the water conduit 110 and sends the value to the control unit 72.

  The storage device 64 stores various setting conditions, threshold values, setting value tables, and the like in advance. The storage device 64 stores various types of information in accordance with instructions from the control unit 72, and reads out and transmits various types of information in accordance with requests from the control unit 72. The storage device 64 may be a magnetic device, a solid-state memory, or a device using other means, and the type is not particularly limited.

  The input device 66 is, for example, a touch panel type input device, and an operator inputs various kinds of information such as a set concentration of chemical liquid, a pressure value, a pressure / injection ratio, and a diameter. The input device 66 sends various input information to the control unit 72.

  The display device 68 is, for example, a liquid crystal panel. The display device 68 displays the operation state of the diaphragm pump 10, the water flow status in the water flow pipe 110, the pressure / injection ratio of the chemical, various input setting conditions, and the like from the control unit 72. Display according to instructions.

  Further, the control unit 72 is connected to the control unit 70 via each signal line. The control unit 70 includes a voltage measurement unit 80, a current measurement unit 82, an ON / OFF switching unit 84, and the like. The control unit 72 and the voltage measurement unit 80 are connected by a signal line 81, the current measurement unit 82 is connected by a signal line 83, and the ON / OFF switching unit 84 is connected by a signal line 85.

  The voltage measurement unit 80 measures the value of the voltage applied to the solenoid coil 14 from the variable DC voltage generation unit 76 and sends the value to the control unit 72. The current measuring unit 82 measures the value of the current flowing through the solenoid coil 14 and sends the value to the control unit 72.

  The ON / OFF switching unit 84 is connected to the solenoid coil 14 of the diaphragm pump 10 through the power line 86, and according to an instruction from the control unit 72, the energization from the variable DC voltage generation unit 76 is turned on / off, and the DC of a predetermined voltage is applied. A voltage is applied to the solenoid coil 14.

  The solenoid coil 14 is provided with an input terminal. As described above, the power line 86 extending from the control unit 70 (ON / OFF switching unit 84) is connected to the input terminal. When power is supplied through the power line 86, the solenoid coil 14 is excited.

  The diaphragm pump configured as described above is used, for example, in a sterilizer that is installed on the primary side of a filtration tank and injects sodium hypochlorite as a sterilizing / oxidizing agent. In addition to the diaphragm pump described above, the sterilizer has a chemical tank for storing sodium hypochlorite, a flow rate detection unit for flow rate proportional injection having a rotor blade with a magnet for detecting the filtration flow rate, and well water passes. The connecting pipe and the chemical solution injection part are configured.

  Hereinafter, a method for controlling the solenoid-driven diaphragm pump and the operation of the diaphragm according to the present embodiment will be described with reference to FIGS. FIG. 4 is a flowchart showing a control procedure until the adjustment voltage V2 is determined. When the power is turned on (ST1), the control unit 72 first obtains a reference voltage V1 required to operate the diaphragm 18 (ST2). The reference voltage V1 may be obtained, for example, by detecting a setting value manually input by the input device 66 and using the value stored in the storage device 64 of the control unit 72 in advance. May be. The reference voltage V1 is based on the thrust obtained by adding the maximum compression force of the return spring and the elastic force when the diaphragm is pushed to the force obtained by multiplying the maximum pressure that can be injected into the product use of the diaphragm pump by the pressure receiving area of the diaphragm, for example. Determined.

  Next, the control part 72 adjusts the voltage value actually applied using this reference voltage V1. FIG. 5 is a graph showing the operation, energization current, and voltage value of the solenoid-driven diaphragm pump in a normal state. The vertical axis represents applied voltage (V), energization current (mA), travel distance (mm), and noise (dB (A)). The horizontal axis represents elapsed time (ms). As operating conditions, an injection pressure of 30 m and a piping pressure of 30 m were set.

  As described above, the solenoid-driven diaphragm pump pushes the plunger against the injection pressure by the generated thrust when discharging the chemical liquid. The solenoid is a variable inductor whose self-inductance changes when the plunger moves. The self-inductance becomes the maximum during the movement, and becomes zero when the movement is finished by contacting the fixed iron core.

  The energization current of the solenoid is determined by the coil inductance and DC resistance. At the beginning of energization, the current value increases according to the charging time constant (= inductance / coil resistance) of the inductor. As a result, the inductance component increases and the current value decreases rapidly. Further, when the plunger moves, the inductance decreases, and the current value increases until energization is completed again.

  When the energization time is long, the stationary solenoid has only a resistance component, so a current obtained by dividing the applied voltage by the DC resistance flows. However, the energization time of the diaphragm pump is a short time of 100 ms or less. The current value is never reached.

  The plunger moving speed (movement distance / required time) is determined by the thrust that the solenoid pushes the plunger against the chemical pressure in the casing of the diaphragm pump. The energization current waveform indicating the change state of the curve has a shape having an inflection point (ΔI is positive → negative → positive or 0) after the first maximum point.

  That is, ΔI of the energization current of the solenoid changes from positive to negative from the start of energization and rapidly decreases, and then starts to increase again after the inflection point (ΔI is negative → 0 → positive). In addition, the current waveform and inflection point generation time of the solenoid are affected by factors caused by the diaphragm pump, such as fluctuations in the solenoid coil resistance and assembly errors of the diaphragm movement distance, and environmental factors such as piping pressure and temperature. Therefore, in the present embodiment, the applied voltage is adjusted based on the current waveform indicating the current change state and the inflection point occurrence time.

  FIG. 6 is a graph showing a current waveform in the normal state as the first state. In the control method according to the present embodiment, the reference inflection point generation time T0 (T0 = 50 ms in the case of FIG. 6) in the normal state is detected and stored, for example, in the initial operation for trial operation adjustment in advance. Alternatively, the inflection point occurrence time may be detected a plurality of times, for example, 20 times in the reference normal state, and the plurality of inflection point occurrence times may be averaged to determine the reference inflection point occurrence time T0.

  FIG. 7 is a graph showing a current waveform when the pipe pressure is higher than the normal state as the second state. The vertical axis represents applied voltage (V), energizing current (mA), and noise (dB (A)), and the horizontal axis represents elapsed time (ms). For example, as shown in FIG. 7, when the actual pipe pressure is higher than the set injection pressure value (eg, injection pressure = 30 m, pipe pressure = 40 m), the chemical pressure against the thrust is high. Therefore, the time until the plunger reaches the position where the inductance is maximum is delayed, and the inflection point of the current waveform moves to the energization stop side.

  In the present embodiment, the state where the shortage of the injection pressure is a certain value or more is detected and adjusted. Note that when the difference in injection pressure is less than or equal to a certain value, the decrease in the injection amount due to insufficient thrust is negligible, so the determination was made based on the constant value.

  For example, as shown in FIG. 4, a test operation is performed at a reference voltage V1 determined in advance by an input setting such as a set pressure (ST3), and an energization current in this test operation is detected (ST4). Then, the reference inflection point occurrence time T0 previously determined and stored in the storage device 64 of the control unit 72 is detected (ST5), and the inflection point occurrence time T of the energized current value and the reference inflection point occurrence time T0 are detected. Are compared (ST6). For example, the reference voltage V1 is set as an optimum value for the normal state and has a value corresponding to the reference inflection point occurrence time T0. For this reason, when the value T obtained as a result of the trial run is longer than the reference value T0 by a certain time t1 or more (yes in ST6), the energization current, that is, the thrust is increased by increasing the voltage applied to the solenoid ( ST7).

  For example, in the example shown in FIG. 7, the inflection point generation time T = about 60 ms of the energized current value is longer than the reference inflection point generation time T0 = 50 ms by a certain time t1 (eg, 6 ms), and is applied to the solenoid. The energizing current, that is, the thrust is increased by increasing the voltage to be applied.

  The ratio of the increase width and the total energization time is set in advance by, for example, experiments. Here, the fluctuation range of the inflection point generation time is about 8 ms with respect to the pressure increase of 10 m, and the ratio to the total energization time (eg, 80 ms) is 5 to 10% longer (7.5% = 6 ms). To do. In addition, an appropriate increase width of the initial applied voltage (example: 30 V) is about 2.0 V with respect to a pressure increase of 10 m, and a ratio between the increase width of the applied voltage and the initial conduction voltage is 5 to 10% (example: 1). .5 to 3.0 V). Note that these set values are merely examples, and the present invention is not limited to these.

  FIG. 8 is a graph showing a current waveform in a state where the pipe pressure is lower than that in the normal state as the third state. The vertical axis represents applied voltage (V), energizing current (mA), and noise (dB (A)), and the horizontal axis represents elapsed time (ms). As shown in FIG. 8, when the actual pipe pressure is lower than the set injection pressure value (eg, injection pressure = 30 m, pipe pressure = 20 m), the chemical liquid pressure against the thrust is low. The time until the plunger reaches the position where the inductance is maximum is shortened, and the inflection point of the current waveform moves to the energization initial side.

  Therefore, as shown in FIG. 4, in ST8 of the present embodiment, is the inflection point occurrence time T of the energized current value obtained as a result of the trial operation shorter than the reference inflection point occurrence time T0 by a predetermined time t2 or more? If it is short (Yes in ST8), the voltage applied to the solenoid is decreased to reduce the energization current, ie, the thrust (ST9).

  For example, in the example of FIG. 8, the inflection point occurrence time T = 40 ms of the energized current value is shorter than the reference inflection point occurrence time T0 = 50 ms by a certain time t2 = 6 ms or more (10 ms = 50-40). The voltage applied to the solenoid is reduced (example: 2.0 V), and the conduction current is reduced. Here, the fixed time t2 is 5 to 10% of the ratio to the total energization time (for example, 80 ms), and is determined here as 7.5% = 6 ms.

  These numerical values are determined from experimental results, for example. Here, as an example, the appropriate decrease width of the initial applied voltage (e.g., 30 V) is about 2.0 V with respect to the pressure 10 ms down, and the ratio between the increase width of the applied voltage and the initial energization voltage is 5 to 10% ( 1.5 to 3.0 V).

  As described above, by adjusting the applied voltage in ST3 to ST9, it is possible to generate a thrust suitable for the injection pressure without using a sensor with a solenoid diaphragm pump. For this reason, even in a site where the pipe pressure fluctuates greatly, there is no possibility of poor injection (high pipe pressure) or increased noise (low pipe pressure).

  Further, the control unit 72 determines whether or not the voltage falls within the applied voltage corresponding to the injection pressure range Tr manually set by the operation unit of the electrical equipment unit (ST10), and when it is out of the injection pressure range (ST10). No), the applied voltage is adjusted to be within the injection pressure range (ST11). For example, the injection pressure range Tr is set based on the maximum specification pressure or the minimum required pressure of the diaphragm pump 10. As a result, even when the thrust correction described above malfunctions, the necessary applied voltage (energization current) and thrust are generated, so that the possibility of insufficient injection or the like can be eliminated.

  The above adjustment is performed, and the value of the adjustment voltage V2 actually applied is determined (ST12).

  The control unit 72 sends an instruction signal to the variable DC voltage generation unit 76 based on the obtained adjustment voltage V2. The value of the obtained adjustment voltage V2 is a pressure sufficient to inject the medicine from the diaphragm pump 10 into the water pipe 110, that is, a value that forms a necessary thrust at start-up.

  In addition, when a desired injection ratio is input from the input device 66, the control unit 72 calculates the injection amount of the medicine to be injected per unit time based on the flow rate in the water conduit 110 sent from the flow rate sensor 114. The basic time interval for sending the ON signal is calculated (ST13). Note that the length of the on-state is set based on the time required for the diaphragm 18 to move by a specified amount with the set adjustment voltage V2.

  In this way, based on the various conditions set, the control unit 72 sends each instruction signal to each unit. The variable DC voltage generator 76 applies a predetermined DC voltage to the controller 70 in accordance with an instruction from the controller 72.

  An instruction to turn on the voltage at a predetermined time interval is sent from the control unit 72 to the ON / OFF switching unit 84. The ON / OFF switching unit 84 turns on the voltage from the variable DC voltage generation unit 76 for a predetermined time in accordance with an instruction from the control unit 72, and turns it on again after a predetermined time elapses after the ON state ends. When the ON / OFF switching unit 84 is turned on, a predetermined voltage is applied to the diaphragm pump 10.

  When a predetermined voltage is applied to the diaphragm pump 10, a current flows through the solenoid coil 14, a magnetic force is generated, and the plunger 16 is attracted. When the plunger 16 is sucked, the diaphragm 18 moves forward in the pressure feeding chamber 54 as shown in FIG. Then, the inflow one-way ball valve 56 is closed, the outflow one-way ball valve 58 is opened, and a predetermined amount of medicine is discharged from the diaphragm pump 10 at a predetermined pressure.

  The medicine that has flowed out of the diaphragm pump 10 passes through the liquid feeding pipe 106, is sent to the mixing portion of the water pipe 110, and is mixed into the fluid (for example, filtered water of well water) that passes through the water pipe 110. The voltage applied from the variable DC voltage generator 76 and the current flowing through the diaphragm pump 10 are measured by the voltage measuring unit 80 and the current measuring unit 82, and the measured values are sent to the control unit 72.

  On the other hand, when energization is stopped by the ON / OFF switching unit 84, the magnetic force in the solenoid coil 14 disappears, and the plunger 16 moves backward by the spring force of the return spring 44. The plunger 16 moves backward until the auxiliary magnetic pole plate 36 contacts the adjustment screw 22. When the plunger 16 is retracted, the diaphragm 18 is retracted in the pumping chamber 54, the inflow one-way ball valve 56 is opened, the outflow one-way ball valve 58 is closed, and a predetermined amount of medicine is transferred from the storage tank 100 to the diaphragm pump. 10 is flowed into.

  The diaphragm pump 10 operates in accordance with the application of voltage from the control unit 70, and mixes a predetermined amount of medicine into the filtered water of the water pipe 110 each time the above-described advancement / retraction of the diaphragm 18 is repeated. The current flowing through the solenoid coil 14 is measured by the current measuring unit 82 and sent to the control unit 72.

  According to this embodiment, the following effects can be obtained. That is, normally, in a solenoid-driven diaphragm pump, it is necessary to set a surplus energizing current and energizing time in consideration of product variation of the solenoid coil resistance value, resistance value increase due to temperature rise, power supply voltage fluctuation, According to the above embodiment, since the energization current value and the energization time can be set based on the waveform of the energization current of the diaphragm pump actually obtained by trial operation, an appropriate voltage can be set in consideration of product specifications, variation, and usage conditions. . For this reason, it is possible to prevent an excess or deficiency of the applied voltage and always set an appropriate numerical value, and to suppress noise at the time of collision of the fixed iron core.

  By adjusting the applied voltage based on the inflection point generation time of the energization current of the diaphragm pump, the adjustment can be easily performed. Since it becomes possible to generate a thrust suitable for the injection pressure without a sensor, a detection mechanism such as a pressure sensor can be omitted, and the configuration can be simplified.

  In addition, when the detected inflection point occurrence time is longer than the reference inflection point occurrence time by a certain value or more, the applied voltage is increased from the previous voltage value. Also, since the applied voltage was reduced, it was not adjusted when the necessity was low. Further, by setting the constant value to 5 to 10%, unnecessary adjustment is not performed, and adjustment can be performed only when necessary.

  Furthermore, by performing secondary adjustment of the adjustment voltage so as to be within the reference range corresponding to the pressure determined by the specification of the diaphragm pump, a value more suitable for each product can be set.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible in the range which does not deviate from the summary of this invention. In addition, the specific configuration of each part, the specific control procedure in each process, and the like are not limited to those exemplified in the above embodiment, and can be appropriately modified.

  In the above embodiment, as an example, the adjustment is performed using the current waveform when the pipe pressure is high and low. However, not only the pipe pressure but also the product variation of the solenoid coil resistance value, the resistance due to temperature rise Since the current waveform (current value change state) changes in the same manner due to changes in various conditions including a rise in value and fluctuations in the power supply voltage, the present invention can be applied to such a case as well, as described above. It is possible to optimize the applied voltage by adjusting using the current waveform.

Furthermore, the present invention can be realized even if some of the constituent features of the above-described embodiment are omitted. Hereinafter, the invention described in the scope of claims of the present application will be appended.
[1]
A method for controlling a solenoid-driven diaphragm pump for injecting liquid,
A method for controlling a solenoid-driven diaphragm pump, wherein an applied voltage or an energizing current applied to the solenoid coil is adjusted based on a change state of a current value during operation of the diaphragm pump.
[2]
2. The method for controlling a solenoid-driven diaphragm pump according to claim 1, wherein the applied voltage or the energizing current is adjusted based on an inflection point generation time of the energizing current of the diaphragm pump.
[3]
When the detected inflection point occurrence time is longer than a reference inflection point occurrence time by a certain value or more, the applied voltage is adjusted by increasing the applied voltage above the reference voltage value,
The applied voltage is adjusted by decreasing the applied voltage below the reference voltage value when the detected inflection point occurrence time is shorter than the reference inflection point occurrence time by a certain value or more. Control method of solenoid-driven diaphragm pump.
[4]
The constant value is 5 to 10% of the total energization time,
The method for controlling a solenoid-driven diaphragm pump according to [3], wherein the adjustment voltage that increases or decreases by the adjustment is 5 to 10% of the initial applied voltage.
[5]
A secondary adjustment of the adjustment voltage is further performed so that the adjustment voltage that increases or decreases by the adjustment falls within a reference range corresponding to the pressure determined by the specification of the diaphragm pump. [4] The method for controlling a solenoid-driven diaphragm pump according to any one of [4].
[6]
A solenoid-driven diaphragm pump for injecting liquid,
A diaphragm pump comprising: a control unit that adjusts an applied voltage or an energization current applied to the solenoid coil based on a change state of a current value during operation of the diaphragm pump.
[7]
The solenoid-driven diaphragm pump according to [6], wherein the control unit adjusts the applied voltage or the energized current based on an inflection point generation time of the energized current of the diaphragm pump.
[8]
The case body,
A pump body attached to one side of the case body;
A solenoid that is fixed to the inside of the case body and is formed of a cylindrical coil;
Plunger having a shaft portion slidably provided in a hole provided at the center of the solenoid, a movable iron core attached to the shaft portion, and an auxiliary magnetic pole plate provided on the other side of the shaft portion When,
The center portion is assembled to the tip of the shaft portion of the plunger, and the outer peripheral portion includes a diaphragm fixed in a liquid-tight manner between the front end edge of the case body and the pump body,
The movable iron core contacts the other surface of the solenoid when the plunger moves forward to a predetermined position, and stops the movement of the plunger. The solenoid-driven type according to [6] or [7] Diaphragm pump.
[9]
A sterilizer comprising the diaphragm pump according to any one of [6] to [8].

10 ... Diaphragm pump, 12 ... Case body, 14 ... Solenoid, 15 ... Hole,
DESCRIPTION OF SYMBOLS 16 ... Plunger, 17 ... Bearing, 18 ... Diaphragm, 20 ... Back cover, 24 ... Pump main body, 32 ... Shaft part, 34 ... Moving iron core, 36 ... Auxiliary magnetic pole plate.

Claims (6)

A method for controlling a solenoid-driven diaphragm pump for injecting liquid,
An inflection point that is an elapsed time from the start of energization when an inflection point where the energization current of the diaphragm pump increases from the start of energization, starts to decrease after the first maximum point, and then starts increasing again is generated. Detect the occurrence time,
When the detected inflection point occurrence time is longer than a reference inflection point occurrence time by a certain value or more, the energizing current is increased by increasing the applied voltage above the reference voltage value,
A solenoid-driven diaphragm characterized in that when the detected inflection point occurrence time is shorter than a reference inflection point occurrence time by a certain value or more, the energization current is reduced by reducing the applied voltage below the reference voltage value. How to control the pump. The constant value is 5 to 10% of the total energization time,
The increase or decrease for adjusting voltage control method according to claim 1, wherein the solenoid driven diaphragm pump, characterized in that 5 to 10% of the initial applied voltage. 3. The secondary adjustment of the adjustment voltage is further performed so that the increase or decrease of the adjustment voltage falls within a reference range corresponding to a pressure determined by a specification of the diaphragm pump. Control method of solenoid-driven diaphragm pump. A solenoid-driven diaphragm pump for injecting liquid,
An inflection point that is an elapsed time from the start of energization when an inflection point where the energization current of the diaphragm pump increases from the start of energization, starts to decrease after the first maximum point, and then starts increasing again is generated. Detect the occurrence time,
When the detected inflection point occurrence time is longer than a reference inflection point occurrence time by a certain value or more, the energizing current is increased by increasing the applied voltage above the reference voltage value,
When the detected inflection point occurrence time is shorter than the reference inflection point occurrence time by a certain value or more, the energization current is reduced by reducing the applied voltage below the reference voltage value . Diaphragm pump . The case body,
A pump body attached to one side of the case body;
A solenoid that is fixed to the inside of the case body and is formed of a cylindrical coil;
Plunger having a shaft portion slidably provided in a hole provided at the center of the solenoid, a movable iron core attached to the shaft portion, and an auxiliary magnetic pole plate provided on the other side of the shaft portion When,
The center portion is assembled to the tip of the shaft portion of the plunger, and the outer peripheral portion includes a diaphragm fixed in a liquid-tight manner between the front end edge of the case body and the pump body,
5. The solenoid-driven diaphragm pump according to claim 4 , wherein when the plunger moves forward to a predetermined position, the movable iron core contacts the other surface of the solenoid to stop the movement of the plunger. A sterilizer comprising the diaphragm pump according to claim 4 or 5 .

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