JP2006242115A - Pump and liquid supply device equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pump and a liquid supply device equipped with the same enabling to use the pump even if flow rate is low and not applying load on piping and not generating noise even if water is stopped very suddenly. <P>SOLUTION: This device includes a pump part 11 sucking and delivering liquid, a motor part 10 driving the pump part 11 and a control part 8 controlling output of the motor part 10, and is provided with a flow rate sensor detecting flow rate of liquid delivered from the pump part 11. The control part 8 is provided with a circuit performing F/V conversion of signal pulse for controlling output of the motor part 10 according to water quantity detected by the signal pulse generated by the flow rate sensor proportionally to flow rate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pump that is driven by a motor and sucks and discharges liquid, and a liquid supply apparatus including the pump.

  The pump includes a pump unit, a motor unit that drives the pump unit, and a control unit that controls the motor unit. The pump is installed in a water passage through which the liquid discharged from the pump unit flows, and the liquid is discharged. And a pressure sensor attached to the water passage and a pressure tank for accumulating pressure (see, for example, Patent Document 1).

  The control unit generates a small water amount detection signal by the flow switch and holds it for a predetermined small water amount detection time, and then accumulates pressure in the pressure tank at a predetermined pressurized pressure value or a pressurized frequency value for a predetermined time, And a pump starting pressure set value.

And when the pump is stopped, the pump is started when the pressure detected by the pressure sensor falls below the pump start pressure setting value. It has a function of automatically setting based on the pump operation time and the number of times the flow switch is opened and closed.
JP-A-9-96278

  However, the pump described in (Patent Document 1) of the prior art cannot control a low flow rate range (for example, about 2 to 4 L / min) due to the characteristics of the flow switch, and further has a hysteresis characteristic. Therefore, when the flow rate is low, the pump may stop.

  In addition, when the water stop is performed steeply, a sudden pressure rise (water hammer) is generated in the water passage, which not only imposes a burden on the pipe but also causes noise.

  The present invention solves such a conventional problem, and the pump can be used even when the flow rate is low, and the pump does not impose a burden on the piping and does not generate noise even when the water is stopped steeply. The purpose is to provide.

  In order to achieve the above-mentioned object, the present invention has a pump part for sucking and discharging liquid, a motor part for driving the pump part, and a control part for controlling the output of the motor part, and the liquid discharged from the pump part. A flow rate sensor for detecting a flow rate is provided, and the control unit converts the signal pulse to a frequency / voltage conversion (to control the output of the motor unit according to the amount of water detected by the signal pulse generated by the flow rate sensor in proportion to the flow rate ( A circuit that performs F / V conversion) is provided.

  With this configuration, it is possible to achieve the effect that the pump does not stop even when the flow rate is low, and that no water hammer is generated even when the water is stopped sharply.

  The present invention is capable of using a pump even when the flow rate is low, and does not give a burden to piping even when water is stopped sharply and does not generate noise, and can provide a liquid supply apparatus including the same. Play.

  The embodiment of the present invention includes a pump unit that sucks and discharges liquid, a motor unit that drives the pump unit, and a control unit that controls the output of the motor unit, and detects the flow rate of the liquid discharged from the pump unit. The control unit is provided with a circuit for F / V converting the signal pulse in order to control the output of the motor unit according to the amount of water detected by the signal pulse generated in proportion to the flow rate of the flow rate sensor. Is.

  Thereby, even when the flow rate is low, it is possible to provide a pump that can always supply liquid without stopping the motor.

  Further, the control unit may be provided with an integration circuit that delays the analog signal output subjected to the F / V conversion.

  In this case, a water hammer is not generated even when the water stop is performed sharply, and therefore a pump that does not impose a burden on the piping and does not generate noise can be provided.

  Further, the control unit may be provided with a circuit for switching between a case where a pulse width modulation signal (referred to as a PWM signal) is generated by a signal pulse of the flow rate sensor and a case where a PWM signal having a predetermined duty ratio is generated.

  In this case, when the flow rate is low, the pressure of the water passage can be secured, and the flow rate of the liquid flowing through the water passage can be maintained.

  And if the said pump is integrated in liquid supply apparatuses, such as a water supply apparatus, the usability of a liquid supply apparatus can be improved greatly.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1
As shown in the block diagram of the DC pump shown in Embodiment 1 in FIG. 1, reference numeral 1 denotes an input / output unit and a connection unit to the outside. Reference numeral 2 denotes a DC motor drive power supplied via the input / output unit 1. Reference numeral 3 denotes a reference potential (GND) of the D pump internal circuit supplied via the input / output unit 1.

  Reference numeral 4 denotes a control power source of a DC motor control circuit supplied via the input / output unit 1. Reference numeral 5 denotes an output pulse signal of the flow sensor supplied via the input / output unit 1. Reference numeral 6 denotes an F / V converter that performs frequency / voltage conversion (F / V conversion) on the output pulse signal 5 of the flow sensor.

  Reference numeral 7 denotes an analog signal converted by the F / V converter 6. A control unit 8 includes a PWM multiplication modulation circuit and a distribution circuit inside and outputs a drive signal corresponding to the voltage level of the analog signal 7. Reference numeral 9 denotes a semiconductor switch (for example, a transistor) that outputs a drive current corresponding to the drive signal output from the control unit 8 and switches a current flowing through the winding.

  Reference numeral 10 is composed of a winding, a stator, and a magnet stator, and the driving current output from the driving unit 9 generates rotational torque by repulsion / attraction of the magnetic field generated in the stator by the current flowing in the winding and the magnetic field of the magnet rotor. It is a motor part which the impeller integrated with a magnet stator rotates.

  Reference numeral 11 denotes a pump unit in which an impeller integrated with a magnet stator that rotates according to the rotational torque generated by the motor unit 10 absorbs and discharges liquid (for example, water). The pump unit 11 includes a water inlet 11a for absorbing water and a water outlet 11b for discharging water.

  A position detection unit 12 detects the polarity of the magnet, which is a component of the motor unit 10, converts it into a voltage signal, and outputs the voltage signal to the control unit 8.

  As shown in the F / V conversion circuit diagram in the DC pump shown in the first embodiment of FIG. 2, the output pulse signal 5 of the flow sensor is supplied to the transistor 22 via a differentiation circuit composed of resistors 13 to 15 and a capacitor 19. Is turned on / off, and the transistor 23 is turned on / off via resistors 16 and 17 and converted to the analog signal 7 via the resistor 18 and capacitor 20. The diode 21 protects the transistor 22 from reverse bias.

  Next, as shown in the waveform diagram at each point of the F / V conversion circuit shown in Example 1 of FIG. 3, 61 is an output pulse of the flow sensor whose pulse frequency gradually increases in synchronization with the start of the flow sensor. It is the waveform of signal 5. An output pulse signal waveform 61 of the flow path sensor is converted into a transistor input waveform 62 through a differentiation circuit composed of resistors 13 to 15 and a capacitor 19.

  The transistor input waveform 62 turns on / off the transistor 22 and turns on / off the transistor 23 via the resistors 16, 17. The ON / OFF output of the transistor 23 is converted through the resistor 18 and the capacitor 20 into an analog signal waveform 63a for pump start of the analog signal 7 that smoothly increases the voltage. F / V conversion can be realized from this operation.

  As shown in the F / V conversion circuit output waveform, the PWM carrier waveform at the time of starting / stopping the DC pump, and the drive waveform at the time of starting / stopping the DC pump shown in the first embodiment of FIG. It is an analog signal waveform of the pump start of the first analog signal 7 of FIG. Reference numeral 64 denotes a PWM carrier waveform inside the control unit 8. The pump start analog signal waveform 63 a is input to the control unit 8, and is modulated with the PWM carrier waveform 64 by a PWM multiplication modulation circuit in the control unit 8.

  Next, the modulated signal is output to the drive unit 9 as a start drive waveform 65a by a distribution circuit in the control unit 8. Since the drive waveform 65a is modulated according to the analog signal waveform 63a of the pump start that smoothly increases the voltage, the duty ratio gradually becomes 100% (the ON time gradually increases), and the DC pump Realizes a smooth start.

  Reference numeral 63b denotes a pump stop analog signal wave which is the waveform of the analog signal 7 when the DC pump is stopped. The operation is the same as described above. Since the drive waveform 65b is modulated in accordance with the analog signal waveform 63b of the pump stop that smoothly decreases the voltage, the duty ratio gradually becomes 0% (the OFF time gradually increases), and the DC pump smoothly Real stop. Reference numeral 24 denotes a DC rising / falling period when the DC pump starts or stops smoothly.

  Next, as shown in the characteristic diagram of the DC pump performance (flow rate and head) shown in the first embodiment in FIG. 5, 25 is the duty of the drive waveform 65. Reference numeral 26 denotes a duty change period of the drive waveform 65 when the DC pump is smoothly started. The DC pump smoothly increases the pump performance by the rotational torque generated according to the duty ratio of the drive waveform 65. When the Duty 25 reaches 100%, the pump head also reaches its maximum.

  Reference numeral 27 denotes a duty change period of the drive waveform 65 when the DC pump is smoothly stopped. The DC pump smoothly lowers the pump performance by the rotational torque generated according to the duty ratio of the drive waveform 65. When the Duty 25 reaches 0%, the pump stops. The pump performance is the same at both start and stop.

  As described above, according to the first embodiment, the pump can be prevented from stopping the function even in a low flow rate region, and in the low flow rate region of constant pressure control, unnecessary pressure generation is eliminated and wasted. Energy can be saved.

(Example 2)
In the second embodiment, components having the same configuration and effects as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description of the first embodiment is used for detailed description thereof.

  As shown in the F / V conversion circuit output waveform, the PWM carrier waveform, and the drive waveform diagram at the time of starting the DC pump according to the second embodiment of FIG. It is an analog signal waveform of the pump start of the analog signal 7 when the capacity is set small. Reference numeral 69 denotes a starting drive waveform modulated and outputted by the control unit 8. Reference numeral 28 denotes a DC pump rising period when the DC pump starts smoothly in the drive waveform 69 of the start.

  67 is an analog signal waveform of the pump start of the analog signal 7 when the capacity of the capacitor 20 is set large.

  Reference numeral 70 denotes a starting drive waveform modulated and output by the control unit 8. Reference numeral 29 denotes a DC pump rising period when the DC pump starts smoothly in the start drive waveform 70.

  The rising / falling period of the DC pump can be arbitrarily set by changing the capacitance setting of the capacitor 20 based on the relationship between the capacity of the capacitor 20 and the rising periods 28 and 29. When the capacity of the capacitor 20 is increased, the rising period becomes longer. It becomes smooth.

  As shown in the characteristic diagram of the DC pump performance (flow rate and head) according to the change in the capacitor capacity shown in Example 2 of FIG. 7, the characteristic diagram of the DC pump performance (flow rate and head) of the capacity of the capacitor 20 is shown. . 31 is a DC pump performance curve when the capacity of the capacitor 20 is small. Reference numeral 32 denotes a DC pump performance curve when the capacity of the capacitor 20 is large.

  When the capacity of the capacitor 20 is large, the rising period becomes longer as described above, and the performance of the low flow rate region of the DC pump is inclined and the smoothness is increased. On the other hand, when the capacity of the capacitor 20 is small, the performance of the low flow rate region occurs contrary to the large capacity, and the smoothness decreases.

  As described above, according to the second embodiment, the DC pump stops smoothly even when steep water stoppage is performed by setting the capacitor capacity according to the equipment. The noise generated by shocking the piping can be eliminated.

(Example 3)
In the third embodiment, components having the same configurations and effects as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description of the first embodiment is used for detailed description thereof.

  As shown in the block diagram of the DC pump shown in the third embodiment in FIG. 8, 35 is a switching signal supplied via the input / output unit 1. Reference numeral 36 denotes a switching unit (for example, a semiconductor switch or a relay) that switches signals. Reference numeral 37 denotes a switching output signal selected and output by the switching unit 36.

  As shown in the F / V conversion circuit, the switching circuit, and the DC voltage circuit diagram in the DC pump shown in the third embodiment of FIG. 9, 38 and 39 are resistors for dividing the voltage of the control power supply 4. Reference numeral 40 denotes a DC voltage which is divided by the resistors 38 and 39 so that the drive waveform becomes 100%. The switching unit 36 can select and output the analog signal 7 or the DC voltage 40 by the switching signal 35.

  Next, as shown in the switching circuit output waveform, the PWM carrier waveform, and the drive waveform diagram shown in the third embodiment of FIG. 10, 71a is a switching unit in which neither the analog signal 7 nor the DC voltage 40 is output from the switching unit 36. It is a waveform without output. Reference numeral 71b denotes a switching unit DC voltage output waveform from which the switching unit 36 selectively outputs the DC voltage 40. Reference numeral 72a denotes a drive waveform in a DC pump stop state corresponding to a state in which the switching unit 36 has no output.

  Reference numeral 72b denotes a PWM 100% drive waveform corresponding to a state in which the switching unit 36 selects and outputs the DC voltage 40. The DC pump maximum capacity can be generated by the switching operation of the switching unit 36.

  Further, the capacity of the DC pump can be arbitrarily set by setting the resistors 38 and 39, and it is also possible to set an arbitrary pump capacity by making the configuration of the switching unit 36 and the resistors 38 and 39 plural. .

  As shown in the characteristic diagram of the performance (flow rate and head) of the DC pump shown in Embodiment 3 in FIG. 11, 41 is a DC pump performance curve of 100% PWM when the switching unit 36 selectively outputs the DC voltage 40. It is. 42 is a DC pump performance curve of the flow rate sensor output pulse signal DC pump when the switching unit 36 selectively outputs the analog signal 7.

  When the pump performance is required in the low flow rate region, the DC performance 40 can be realized by operating the switching unit 36 and outputting the DC voltage 40 to realize the DC pump performance curve 41 with the PWM of 100%.

  As described above, according to the third embodiment, a pump (for example, a self-priming pump) that requires pressure or flow rate in a low flow rate region can be easily realized.

  When the pump shown in any one of the first to third embodiments is incorporated in, for example, a bath water circulation device, the pumps shown in Embodiments 1, 2, and 3 of FIG. 12 are incorporated in the bath water circulation device. As shown in the overall schematic diagram at the time, there is a bathtub 44 made of artificial marble, stainless steel, FRP (fiber reinforced plastic) or the like, and the bathtub water 45 in the bathtub 44 is sucked and discharged outside the bathtub 44. A pump 46 for heating and a heating unit 47 using gas, electricity, kerosene or the like for heating the bath water 45 are installed.

  An outlet 48 for the bathtub water 45 is attached to the lower side surface of the bathtub 44, and a circulation path 49 made of heat-resistant PVC (vinyl chloride), stainless steel or the like is connected to the outlet 48.

  A pump 46 is attached in the middle of the circulation path 49, and the circulation path 49 is connected to the heating unit 47.

  A circulation return path 50 made of heat-resistant polyvinyl chloride (vinyl chloride), stainless steel, or the like is also connected to the heating unit 47, and the circulation return path 50 is a side surface of the bathtub 44 and is an inlet that is installed above the outlet 48. 51 is connected.

  The pump of the present invention can be expected to be applied to various pumps used in, for example, fuel cell devices and heat pump devices.

Block diagram of the DC pump shown in the first embodiment F / V conversion circuit diagram in the DC pump shown in the first embodiment Waveform chart at each point of the F / V conversion circuit shown in the first embodiment F / V conversion circuit output waveform, PWM carrier waveform, and DC pump start / stop drive waveform diagram when starting / stopping the DC pump shown in the first embodiment Characteristic diagram of DC pump performance (flow rate and head) shown in Example 1 F / V converter circuit output waveform, PWM carrier waveform, and DC pump drive waveform diagram at the time of starting the DC pump according to the change in the capacitor capacity shown in the second embodiment Characteristic diagram of DC pump performance (flow rate and head) according to the change in capacitor capacity shown in Example 2 Block diagram of DC pump shown in Embodiment 3 F / V conversion circuit, switching circuit, and DC voltage circuit diagram in the DC pump shown in the third embodiment Switching circuit output waveform, PWM carrier waveform, and drive waveform diagram shown in the third embodiment Characteristic chart of performance (flow rate and head) of DC pump shown in Example 3 Overall schematic diagram when the pumps shown in Examples 1, 2, and 3 are incorporated in a circulating device for bath water

Explanation of symbols

1 I / O unit 2 Drive power supply 3 Reference potential (GND)
4 Control power supply 5 Output pulse signal of flow sensor 6 Frequency / voltage converter (F / V converter)
7 Analog signal 8 Control unit 9 Drive unit 10 Motor unit 11 Pump unit 11a Water inlet 11b Water outlet 12 Position detecting unit 13, 14, 15, 16, 17, 18 Resistor 19, 20 Capacitor 21 Diode 22, 23 Transistor 24 DC pump Rise and fall period 25 Duty
26 Duty change period at start-up 27 Duty change period at stop 28 DC pump start-up period (capacity: small)
29 DC pump rise period (capacity: large)
31 DC pump performance curve (capacity: small)
32 DC pump performance curve (capacity: large)
33 Duty change period at start-up (capacity: small)
34 Duty change period at start-up (capacity: large)
35 switching signal 36 switching unit 37 switching unit output signal 38, 39 resistance 40 DC voltage 41 DC pump performance curve of PWM 100% 42 DC pump performance curve of flow rate sensor output pulse signal 43 observation point of transistor input waveform 44 bathtub 45 bathtub water 46 Pump 47 Heating part 48 Outlet 49 Circulation forward 50 Circulation return 51 Inlet 61 Flow rate sensor output pulse signal waveform 62 Transistor input waveform 63a Pump start analog signal waveform 63b Pump stop analog signal waveform 64 PWM carrier waveform 65a Start drive Waveform 65b Drive waveform of stop 66 Analog signal waveform of pump start (capacity: small)
67 Analog signal waveform for pump start (capacity: large)
69 Drive waveform of start (capacity: small)
70 Start drive waveform (capacity: large)
71a Switching unit no output waveform 71b Switching unit DC voltage output waveform 72a DC pump stopped drive waveform 72b PWM 100% drive waveform

Claims (4)

The control unit includes a pump unit that sucks and discharges liquid, a motor unit that drives the pump unit, and a control unit that controls output of the motor unit, and includes a flow rate sensor that detects the flow rate of the liquid discharged from the pump unit. The pump is provided with a circuit for frequency / voltage conversion of the signal pulse in order to control the output of the motor unit in accordance with the amount of water detected by the signal pulse generated by the flow sensor in proportion to the flow rate. 2. The pump according to claim 1, wherein the control unit is provided with an integration circuit that delays an analog signal output subjected to frequency / voltage conversion. The said control part provided the circuit which switches between the case where a pulse width modulation signal is generated with the signal pulse of a flow sensor, and the case where a PWM signal of a predetermined duty ratio is generated. pump. A liquid supply apparatus comprising the pump according to claim 1.

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