JP5061620B2 - Pump device and dishwasher using the same - Google Patents

Description

  The present invention relates to a pump device that transfers a liquid such as water, and a dishwasher that is used for business use, general household use, business use, and the like.

  Conventionally, this type of dishwasher using a pump device detects a rotational speed detected by a rotation sensor by temporarily rising when bubbles are sucked into the pump (see, for example, Patent Document 1). .

  FIG. 15 shows a cross-sectional view of a conventional dishwasher described in Patent Document 1. As shown in FIG. As shown in FIG. 15, the pump 2 using the DC brushless motor 1 has a rotation sensor 4 using a Hall IC that detects the position of the rotor 3, and the rotation speed can be adjusted from a separately provided control device. The value of the rotation speed of the impeller 5 directly connected to the rotor 3 can be detected from the output of the rotation sensor 4.

  The washing water sent out from the impeller 5 is jetted into the chamber from the nozzle 6, but when it is lower than the reference water level H, bubble biting occurs.

FIG. 16 shows a pump rotation speed graph when the conventional dishwasher described in Patent Document 1 is chewed with foam. From the time t1 when the generation of bubbles starts to increase, the torque of the load is reduced, and the rotation speed is increased. From S0 without foaming, to reduce the speed at the time t2 when S1 is reached, the speed is reduced. By operating at S2 at a reduced rotational speed, the operation that prevents the biting of the bubbles is continued for 5 minutes, and then returned to the steady rotational speed S0 at t3.
JP-A-2005-511

  However, the conventional configuration has a problem that the device becomes expensive because the rotation sensor 4 using, for example, a Hall IC is required.

  In the prior art, the rotation sensor 4 detects the position of the rotor 3 having a permanent magnet when the DC brushless motor 1 is operated, and therefore exists when the DC brushless motor 1 is configured. However, the cost is high, and there is a configuration in which the DC brushless motor 1 is operated without the rotation sensor 4 using a technique called sensorless vector control, for example.

  However, even if such a configuration is used, an expensive control device generally called an inverter circuit or the like is required, and thus there is an unavoidably high cost.

  On the other hand, it is extremely effective to use a kind of induction motor (induction motor) such as a capacitor motor (capacitor run motor), which is much more effective than a DC brushless motor. Cost can be reduced.

  However, in that case, providing the rotation sensor 4 again for detecting the bubble biting leads to an increase in cost, and the rotation sensor 4 is provided only for the bubble biting detection. When wiring to a circuit board using a microcomputer or the like is provided, there is a problem that even if a low-priced induction motor is used, the cost advantage is small.

  The present invention solves the above problems, and uses a low-cost induction motor, does not require a rotation sensor, and can provide a low-cost pump device that can properly detect foam biting, and a dishwasher using the pump device. It aims to be realized.

In order to solve the above problems, a pump device according to the present invention includes a phase advance capacitor, an induction motor having a plurality of windings including a series connection of the phase advance capacitor, and a current flowing through at least one winding. An electric quantity detection means for detecting a bubble and a bubble biting determination means, wherein the bubble biting judgment means receives a signal including a harmonic component that increases when the bubble is bitten from the electric quantity detection means , and the electric quantity detection means The bubble biting is determined when the ratio of the harmonic component to the fundamental wave component becomes equal to or greater than a predetermined value .

  As a result, it is possible to realize a pump device that does not require an inverter circuit, uses a low-cost induction motor, has a rotation sensor, and can determine bubble biting with a relatively simple configuration. Become.

  The present invention can realize a pump device that uses an induction motor and has a low-cost configuration that does not include a rotation sensor, and that can determine whether or not a bubble is caught.

The first invention is an induction motor having a phase advance capacitor, a plurality of windings including a winding in which the phase advance capacitor is connected in series, an electric quantity detection means for detecting a current flowing in at least one winding, A bubble biting determination unit, the bubble biting determination unit receives a signal including a harmonic component that increases when the bubble bites from the electric quantity detection unit, and generates a harmonic component relative to a fundamental wave component of the electric quantity detection unit. By adopting a configuration in which the bubble biting is determined when the ratio exceeds a predetermined value , the bubble biting determination can be performed relatively easily while using an inexpensive induction motor and having a low cost without a rotation sensor. Will be able to.

  In the second invention, the electric quantity detected by the electric quantity detection means of the first invention is the current flowing through the series circuit of the winding of the induction motor and the phase advance capacitor, so that a relatively small current can be reduced to a small electric It is possible to realize a low-cost pump device capable of effectively performing the bubble biting determination while being realized by the amount detection means.

  In the third aspect of the invention, the electric quantity detected by the electric quantity detection means of the first invention is the current flowing through the winding of the induction motor not connected to the phase advance capacitor, so that a relatively small current is reduced to a small electric quantity. A low-cost pump device that can effectively perform the bubble biting determination while being realized by the detection means can be realized.

  In the fourth invention, the electric quantity detected by the electric quantity detection means of the first invention is set to the current supplied from the AC power source to the induction motor, thereby grasping the total current supplied to the induction motor. A pump device capable of detecting bubble biting can be realized.

According to a fifth aspect of the present invention, there is provided an induction motor having a plurality of windings including a phase advance capacitor, a winding in which the phase advance capacitor is connected in series, and an electric quantity for detecting a potential at a connection point between the phase advance capacitor and the winding. A detection means and a bubble biting determination means, wherein the bubble biting determination means receives a signal including a harmonic component that increases when the bubble bites, from the electric quantity detection means, and with respect to the fundamental wave component of the electric quantity detection means By adopting a configuration in which the bubble biting is determined when the ratio of the harmonic components exceeds a predetermined value, it is possible to configure the electric quantity detection means at a simple and low cost such as resistance partial pressure. It is possible to realize a pump device that is superior in terms of surface.

In addition to the configuration of any one of the first to fifth inventions, the sixth invention has power supply frequency detection means for detecting the frequency of the AC power supply, and corresponds to at least two AC power supply frequencies. By adopting a configuration in which the determination threshold value is changed, even when there are power supply frequencies of 50 Hz and 60 Hz as in Japan, for example, correct bubble biting determination corresponding to the power supply frequency can be performed.

The seventh invention has the pump device according to any one of the first to sixth inventions, and when the bubble biting determination is made, the induction motor is temporarily stopped to suppress a decrease in pump performance due to the bubble biting. A dishwasher can be realized.

According to an eighth aspect of the present invention, there is provided a pump device according to any one of the first to sixth aspects and a water supply means, and when the bubble biting is determined, the water supply means performs a water supply operation to thereby It becomes possible to realize a dishwasher that suppresses a decrease in pump performance due to chewing.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a circuit diagram of a pump device according to a first embodiment of the present invention. In FIG. 1, an AC power supply 10 having the possibility of two types of frequencies of 100 V 50 Hz or 60 Hz, an induction motor 11 having one terminal connected to the AC power supply, a phase advance capacitor 12, a triac 13, a zero volt signal generating circuit 15, Resistors 22, 23, 24 for turning on and off the triac 13 in accordance with the amount detection means 17, the foam biting judgment means 18, 5 V DC power supply 20 constituted by a microcomputer, and the output Q of the foam biting judgment means 18, a transistor 25 It has become that.

  The induction motor 11 includes two windings 30 and 31 and a rotor 32. The winding 30 operates as a main winding, and the winding 31 is connected to the phase advance capacitor 12 in series. In addition, the AC power supply 10 operates as an auxiliary winding to which a current having a phase advanced from that of the winding 30 is supplied.

  The zero volt signal generation circuit 15 includes diodes 35 and 36, resistors 40, 41, 42, 43, and 44, a photocoupler 50 configured as a composite part of a light emitting diode and a phototransistor, a transistor 51, and a capacitor 52. A signal having an edge is generated at a timing of high when the polarity is positive, low when the polarity is negative, and approximately zero volts.

  The electric quantity detection means 17 includes a current transformer 60 having a primary coil connected in series with the winding 31, resistors 61, 62, 63 and 64, protective diodes 66 and 67, and a capacitor 68. The current flowing through 31 is detected, and an analog voltage V1 corresponding to the instantaneous value of the current is output.

  FIG. 2 is a waveform diagram showing the operation of each part of the pump device in the present embodiment when the AC power supply 10 is 60 Hz and foaming is occurring. The voltage VAC waveform, (A) shows the waveform of the output voltage Vz of the zero volt signal generation circuit 15, and (C) shows the waveform of the output voltage Va of the electric quantity detection means 17.

  At time t0, the voltage of the AC power supply 10 becomes zero, but as shown in (A), at this moment, the zero volt signal generation circuit 15 causes the output voltage Vz to rise from low to high. ing.

  After that, every 8.33 ms, the AC power supply 10 is half cycle and repeats high and low.

  Further, (c) is the sampling of the voltage value Va at the timing of t0, t1, t2, t3..., And in the bubble biting judgment means 18 constituted by the microcomputer as v0, v1, v2, v3. It will be taken in.

  In the present embodiment, a DC power supply 20 of 5V is used, and the resistors 62 and 63 are both 4.7 kilohms. Therefore, the voltage waveform of Va shown in (c) is 2 at the current zero point. .5V corresponds to the waveform in which the similar waveform of the current waveform flowing in the winding 31 is superimposed on this, and the positive and negative have almost the same amplitude, so the zero point of the current is converted to Va = 2.5V Therefore, analog / digital conversion (A / D conversion) becomes possible by effectively using the voltage range of 0 to 5V, and when converting to an 8-bit digital value, 128 correspond to the positive current value from 129 to 255, and the negative current value from 0 to 127.

  Regarding the current waveform in this portion, when bubble chewing occurs and the load torque of the induction motor 11 decreases, the Q value (resonance strength) of the resonance operation of the winding 31 and the phase advance capacitor 12 increases. Moreover, due to the magnetic saturation of the iron core in the induction motor 11 and the generation of third harmonic components, etc., in the excitation current, the distortion of current and voltage waveforms in each part increases, and harmonic components such as third harmonics. Tends to be included, and the same tendency is observed for the waveform of the voltage Va.

  FIG. 3 shows a flowchart of a microcomputer program used for the bubble biting determination means 17 of the pump device of the present embodiment.

  In FIG. 3, the process starts from the start 69, passes through the frequency determination routine 70, reaches the Vz rising edge 71, waits for the rising edge of the Vz signal, and moves to the following process.

  In the input 72, the respective sampling data v0 to v11 are sequentially input, and in the fundamental wave calculation 73, approximate values of values corresponding to the sine component and cosine component in terms of Fourier series expansion are signed into the variables S1 and C1. A 16-bit variable is used, and the sum of squares thereof is calculated in A1, which corresponds to an approximate value of a value corresponding to the square of the absolute value of the fundamental wave component.

  Note that S1 and C1 are multiplied by a factor of three, which will be multiplied later to eliminate unfairness due to the difference in the number of sampling in correspondence with the third harmonic.

  Further, as described above, the current value zero corresponds to the value 128, but in the calculation of S1 and C1, since it is canceled because it is subtracted, for example, resistors 62 and 63 are used. Due to the resistance value variation, even if the digital value corresponding to the current zero deviates from 128, the calculation results such as S1, C1, A1, etc. will not be affected. Even if a low-cost resistor with uneven resistance values is used as 63, the result can be hardly affected.

  As for the fundamental wave calculation 73, since A1 is a value proportional to the square of the effective value of the fundamental wave current, square root calculation may be performed, but in order to reduce the load on the microcomputer, In the embodiment, the numerical values in the state corresponding to the square are used, and the same applies to the calculation of the third harmonic described later.

  In the A1 determination 74, when the value of the fundamental wave component is equal to or less than a predetermined value, it is excluded from the target condition for the bubble biting determination, thereby generating an unnecessary signal when the induction motor is stopped. It is something that is preventing.

  The third-order harmonic calculation 75 is a part for calculating an approximate value corresponding to the third-order harmonic component, similarly to the fundamental wave production 73, and the values of S3, C3, and A3 are calculated. .

  Note that the fundamental wave calculation 73 and the third harmonic calculation 75 performed in the present embodiment are simple calculation methods for calculating the approximate value of each component. If the phase interval is short and a method such as full-scale Fourier series expansion using trigonometric functions at each phase is used, the calculation value changes due to the phase of each order component, or the calculation is based on the presence or absence of higher harmonic components. It is also possible to suppress changes in the value.

  In this embodiment, all 12 data for one cycle of the AC power supply 10 are once input, and then S1, C1, S3, and C3 are calculated. However, every time sampling is performed, addition or subtraction is performed. In this case, the processing speed of the microcomputer is required to be slightly higher, but the time until the result is obtained can be shortened, and the data storage area The merit that it can be reduced occurs.

  In order to suppress the influence of the calculation due to the higher-order harmonics, for example, a method of adding a hard filter circuit with RC and inserting it into the output of the electric quantity detection means 17 may also work effectively.

  Further, in order to shorten the sampling phase interval, it may be necessary to increase the processing speed of the microcomputer, but in one cycle (16.67 ms at 60 Hz), all sampling is not completed. If a method of sampling the intermediate timing of the sampling phase of the first cycle in the cycle is used, the microcomputer can be used even with a low processing speed.

  The ratio calculation 76 obtains a value corresponding to the square of the ratio of the third harmonic component with respect to the fundamental wave, sets it as a variable R3, and when the R3 determination 77 is larger than Y, the “bubble bite” determination 78 is determined. In this embodiment, by setting Y = 0.014, appropriate bubble biting determination is made.

  Therefore, in the pump device of the present embodiment, the bubble biting determination means 18 receives a signal including a harmonic component that increases when the bubble bites from the electric quantity detection means 17, and determines the bubble biting. In addition, the bubble biting determination unit 18 is configured to determine the bubble biting when the ratio of the harmonic component to the fundamental wave component of the electric quantity detection unit becomes a predetermined value or more.

  In this embodiment, since A1 and A3 are both values corresponding to the square of the harmonic component, R3 is a value corresponding to the square of the ratio of the third harmonic component to the fundamental component. However, if the predetermined value Y is determined in consideration of this, it is possible to determine the bubble biting when the ratio of the harmonic component to the fundamental component exceeds the predetermined value. Become.

  In any case, since the ratio with respect to the fundamental wave component becomes the object of determination, the characteristic variation of the current transformer 60 and the resistor 61 of the constituent elements of the electric quantity detection means 17 is hardly affected, and the reliability Although it is effective as a pump device that makes highly accurate bubble biting judgments, sufficient reliability can be achieved by judging only from harmonic components without taking a ratio to the fundamental wave components. In this case, for example, the presence or absence of bubble chewing can be determined based on whether A3 is larger than a predetermined value.

  Of course, when there is a margin in the capacity of the microcomputer to be used, square root calculation of A1, A3, or R3 may be performed.

  In this embodiment, only the third harmonic is used as the harmonic, but this is because the third harmonic component is larger than the other harmonics in the current waveform flowing through the part, and bubble biting occurs. This is due to the fact that a large change was observed, but depending on the design, the bubble biting is judged by a change in other orders other than the third harmonic, and the harmonic components of a plurality of orders are used. A synthesized value, for example, the sum of the squares of the components of each order may be used, but in that case, a configuration such as increasing the number of samplings or shortening the sampling time interval is required. In addition, there is a need for a flowchart for performing calculations such as adding R5 corresponding to the fifth harmonic and R7 corresponding to the seventh harmonic to R3. To become.

  FIG. 4 is a flowchart showing the details of the frequency determination routine 70 in some detail. In FIG. 4, from the start 85 of this routine, a Vz rise wait 86 is entered, and at the rise of the Vz signal, the process moves to 18.3 ms wait 87, and after 18.3 ms, Vz = High? If it enters 88 and is high, it will be determined that it is 60 hertz, and if it is low, it will be determined that it is 50 hertz.

  The above-described portion is the configuration of the power supply frequency determination unit 89, and the frequency is determined by reconfirming the state of the Vz signal when 18.3 ms has elapsed from the rising timing of the Vz signal. However, the power frequency determining means 89 is not particularly required to have such a configuration, and various other configurations can be used, and the determination result of the power frequency is affected by noise or the like. For the purpose of elimination, a configuration in which a final determination is performed after performing a plurality of determinations is often used and is very effective in preventing malfunction.

  In the case of 60 hertz, substitution of Y ← 0.014 is performed at 90, and substitution of Ts ← 1.39 ms is performed at 91.

  On the other hand, in the case of 50 hertz, substitution of Y ← 0.010 is made at 93, and substitution of Ts ← 1.67 ms is made at 94.

  Here, Ts is a sampling time interval, and a value that is one-twelfth of the period of the AC power supply 10 is set as Ts. With regard to Y, when bubble biting occurs The value of Y is set according to each frequency as a threshold that can sufficiently detect an increase in the increasing harmonic current component.

  In the present embodiment, since the same value is set for X regardless of whether it is 50 Hz or 60 Hz, the flowchart is configured with the X setting 95 combined into one. ing.

  However, especially when the magnitude of the current is significantly different between 50 Hz and 60 Hz, the values of X may be different from each other, and can be realized by moving before the merge of the flowcharts.

  At return 96, the frequency determination routine 70 is completed and the process returns to the main routine.

  In this way, the pump device of the present embodiment has the power frequency detecting means 89 for detecting the frequency of the AC power supply 10, and corresponds to two AC power supply frequencies of 50 Hz and 60 Hz, respectively. By setting the value, the threshold value for bubble biting determination is changed. Therefore, the correct bubble biting decision can be made at any frequency even in the mixed condition of 50 Hz and 60 Hz in Japan. A pump device capable of achieving the above can be realized.

  FIG. 5 shows the waveform of the output voltage Va of the electric quantity detection means 17 in the pump device of the present embodiment, that is, the waveform corresponding to the current flowing through the series circuit of the phase advance capacitor 12. (A) 60 Hz, no bubble biting operation, (A) 60 Hz, no bubble biting operation, (C) 50 Hz, no bubble biting operation, (D) 50 Hz, no bubble biting operation It is during driving with biting.

  Note that the numerical value indicating the magnitude of the amplitude in each figure is not the Va value itself but the input current value of the electric quantity detection means 17.

  As seen in FIG. 5, there are differences in the current value and current waveform due to the difference in power supply frequency conditions of 50 Hz and 60 Hz, but the magnitude of the distortion of the current waveform is the case at either frequency. When there is a bubble bite, it will be larger than when there is no bubble bite. Especially, the ratio of the third harmonic to the fundamental wave component is calculated, and the threshold value is set appropriately for each power frequency. By using the configuration of the present embodiment, it is possible to determine the presence or absence of foam biting with sufficient reliability.

(Embodiment 2)
FIG. 6 is a circuit diagram of a pump device according to the second embodiment of the present invention. In FIG. 6, the electric quantity detection means 17 is connected and the winding 30 of the induction motor 11 is used as a current to be detected. However, the configuration of other parts is different from that of the first embodiment. However, there are no equivalent components.

  Therefore, in the present embodiment, the amount of electricity detected by the amount-of-electricity detection means 17 is a current flowing through the winding 30 of the induction motor 11 that is not connected to the phase advance capacitor 12.

  FIG. 7 shows the waveform of the output voltage Vb of the electric quantity detection means 17 in this embodiment, and the winding that operates as the main winding or main winding of the induction motor 11 generally called a capacitor motor or capacitor run motor. The waveform corresponds to the current supplied to the line 30.

  In FIG. 7, (A) is in a state where there is no bubble biting, and (A) is in a state where there is bubble biting, but the frequency of the AC power supply 10 is 60 Hz.

  The numerical value indicating the magnitude of the amplitude in each figure is not the Vb value itself but the input current value of the electric quantity detection means 17.

  Also in the present embodiment, since there is a tendency that the harmonic component contained in the output voltage of the electric quantity detection means 17 is larger when there is bubble biting, the bubble biting is the same as in the first embodiment. It is possible to determine whether or not there is any.

(Embodiment 3)
FIG. 8 is a circuit diagram of a pump device according to the third embodiment of the present invention. In FIG. 8, the electric quantity detection means 17 is connected, and the current to be detected is a supply portion from the AC power source to the induction motor 11, but the configuration of the other portions is the first embodiment. There is no difference from the form, and it uses completely equivalent components.

  Therefore, in the present embodiment, the amount of electricity detected by the amount-of-electricity detection means 17 is a current supplied from the AC power supply 10 to the induction motor 11.

  FIG. 9 shows the waveform of the output voltage Vc of the electric quantity detection means 17 in the present embodiment, which corresponds to the current waveform obtained by summing the supply currents of the induction motor 11. In FIG. 9, (A) is in a state where there is no foam bite, and (A) is in a state where there is bubble bite, these are 60 Hz as the frequency of the AC power supply 10.

  In addition, regarding the numerical value indicating the magnitude of the amplitude in each figure, it is indicated not by the Vc value itself but by the input current value of the electric quantity detection means 17.

  Also in the present embodiment, since there is a tendency that the harmonic component contained in the output voltage of the electric quantity detection means 17 is larger in the case where there is bubble biting, the same as in the first embodiment, The presence or absence of biting can be determined.

  In the present embodiment, the magnitude of the current input to the electric quantity detection means 17 is larger than that in the first embodiment and the second embodiment. However, since it becomes a total current supplied to the induction motor, detection of the state of the induction motor 11 other than the presence or absence of bubble chewing, for example, grasping the state of heat generation, or the like The range that can be used for other control is expanded.

(Embodiment 4)
FIG. 10 is a circuit diagram of a pump device according to the fourth embodiment of the present invention. In the present embodiment, of the windings 30 and 31 of the induction motor 11, the winding 31 connected in series with the phase advance capacitor 12 is connected to the connection point between the phase advance capacitor 12 and the winding 31. In addition, an electric quantity detecting means 100 for detecting the potential is provided.

  The configuration of the electric quantity detection means 100 includes resistors 101, 102, 103, 104, diodes 105, 106, and a capacitor 107, which corresponds to the voltage between the terminals of the phase advance capacitor 12 that is driving the induction motor 11. The center voltage is set to approximately 2.5 V corresponding to ½ of the voltage of the DC power supply 20 by the three resistors 101, 102, 103, and the voltage is divided to exceed the voltage range of the DC power supply 20. In order to prevent this, the protection by the diodes 105 and 106 and the filtering function of the resistor 104 and the capacitor 106 that remove unnecessary high-order harmonics and noise are added, and the analog output voltage Vd is configured by a microcomputer. This is applied to the bubble biting determination means 18.

  The configuration of other parts is exactly the same as that of the first embodiment.

  FIG. 11 shows operation waveforms in the state where the AC power supply 10 is operating at 100 V 60 Hz in the pump drive device of the present embodiment. The Vd waveform in the state where there is a bubble bite is shown.

  However, the numerical value indicating the magnitude of the amplitude in each figure is not the Vd value itself but the input voltage value of the electric quantity detection means 17.

  Since the current flowing through the phase advance capacitor 12 has the waveform described in the first embodiment, the voltage between the terminals of the phase advance capacitor 12 is integrated. Since the third harmonic component is also included in the voltage waveform of the phase capacitor 12, the third harmonic component, which is one of the harmonic components, is obtained by the bubble biting determination means 18 realized by a microcomputer. By detecting the above, when the third harmonic component equal to or greater than the predetermined value is included, the bubble biting and the determination result can be obtained.

  In the present embodiment, the current transformer used in the first embodiment is unnecessary, and voltage detection is performed by using the relatively low-cost resistors 101, 102, and 103 instead. The amount detecting means 100 has an effect that it can be made low cost.

  However, since the terminal voltage of the phase advance capacitor 12 tends to be lower as the frequency component becomes higher, it tends to be smaller in terms of the content ratio of the harmonic component. This is effective when the design is such that the increase in harmonic current components is considerably large.

  As described above, the pump devices shown in the first to third embodiments detect the foaming by detecting the harmonic component, thereby determining the bubble biting while having a low-cost configuration without a rotation sensor. Can be done.

  In some embodiments, the case of 50 Hz is not described. However, in the same manner as in the first embodiment, by providing the frequency determination means 89, each is normal under a plurality of power supply frequency conditions. A bubble chewing determination is performed.

(Embodiment 5)
FIG. 12 is a sectional view of a dishwasher according to the fifth embodiment of the present invention. In FIG. 12, the induction motor 11, the phase advance capacitor 12, the triac 13, the electric quantity detection means 17, and the bubble biting determination means 18 are the same as those described in the first embodiment, and the pump device 110 is configured. The bubble biting determination is performed based on the harmonic component contained in the current of the winding 31 to which the phase advance capacitor 12 is connected.

  As shown in FIG. 1 and the like, the triac 13 is turned on when the Q signal output from the bubble biting determination means 18 using a microcomputer is high, and is turned off when the signal is low. ing.

  The water supply pipe 112 and the water supply valve 113 connected to the water supply constitute the water supply means 114, and the water supply valve 113 can be controlled to be opened / closed by the microcomputer used for the bubble biting determination means 18. It has become.

  The operation of the dishwasher includes a washing process in which water (washing water) containing detergent in the dishes is circulated by the pump device 110 and a rinsing process in which fresh water is circulated. At the stage of completion, there is a process of draining the in-machine water or the washing water from the pump device 110 to the outside of the machine.

  FIG. 13 shows an operation waveform diagram of the washing process. (A) is a signal sent to the water supply valve 113 of the water supply means 114, and if it is high, water is supplied.

  (A) is an output signal of the bubble biting detection means 18. If it is high, it is in a state where it is determined as bubble biting.

  (C) is an on / off signal Q to the triac 13, and if it is high, the induction motor 11 is driven.

  In the period of the washing process in which the dishes are being washed, the dishwasher of the present embodiment temporarily supplies the water supply means 114 at time t2 when the water supply means 114 is in the water supply state at t1 and the minimum amount of water is introduced into the machine for the time being. Becomes a state where water supply is stopped, and at the same time, Q rises and the pump device 110 is operated.

  At t3, the pump device 110 determines that the foam is engaged, and at t4, the water supply valve 113 is opened, and the water supply means 114 performs the water supply operation until t5 after 5 seconds from t4.

  In the present embodiment, since the Q signal continues to be high, the induction motor 11 continues to be driven, and the high signal continues until the bubble bite disappears.

  By such an operation, the water level in the machine rises and the occurrence of bubble biting is suppressed.

  Thereafter, when the bubble biting determination means 18 detects that there is a bubble bite, the water supply operation is performed each time.

  Therefore, in the present embodiment, when there is no bubble biting, the operation is continued at the same water level, so that it is possible to operate with a sufficient amount of water necessary for the operation of the pump device 110, and wasteful water Consumption can be reduced as much as possible.

  FIG. 14 shows operation waveform diagrams during drainage, and (a), (b), and (c) show operation waveform diagrams of the same parts as in FIG.

  At the time of drainage, the drainage operation is started by setting Q to high at time t6, but Q is set to low at time t7 when there is a determination of bubble biting while the pump device 110 is operating. Then, the induction motor 11 is temporarily stopped and the pump device 110 stops operating.

  This is an operation for avoiding the occurrence of bubble biting once the function of the drainage is extremely impaired even if the operation of the pump device is continued as it is.

  As a result, the air that has been engaged in the foam returns to the water surface, and the pump device 110 naturally returns to the state without the foam engagement.

  At t8 after 5 seconds, Q is set to high, the TRIAC 13 is turned on again, and the draining operation is continued again. By performing such an operation, the amount of water remaining in the machine after draining (residual water amount) ) Can be suppressed as much as possible.

  Therefore, it becomes possible to improve the performance of rinsing by reducing the amount of residual cleaning water containing dirt and detergent, shorten the time by reducing the number of times of rinsing, and when all the steps are completed Since the amount of remaining water can be minimized, adverse effects on the next operation due to rot can be minimized.

  As described above, the pump device according to the present invention uses an induction motor and a low-cost induction motor by providing an electric quantity detection unit that receives a signal including a harmonic component that increases when a bubble is bitten. , A low-cost pump device that does not require a rotation sensor, can detect foam biting appropriately, and a dishwasher that suppresses the use of wasted water and reduces the amount of remaining water during drainage. .

Circuit diagram of pump device in Embodiment 1 of the present invention (A) Voltage waveform diagram of AC power source of the pump device (A) Output voltage waveform diagram of the same zero volt signal generating warmer (C) Output voltage waveform diagram of the same electric quantity detection means Main flowchart of microcomputer used for bubble biting determination means of the pump device Flowchart of microcomputer frequency determination routine of the pump device (A)-(D) Output voltage waveform diagram of electric quantity detection means of the pump device Circuit diagram of pump device in embodiment 2 of the present invention (A) (a) Output voltage waveform diagram of the electric quantity detection means of the pump device Circuit diagram of pump device in embodiment 3 of the present invention (A) (a) Output voltage waveform diagram of the electric quantity detection means of the pump device Circuit diagram of pump device in embodiment 4 of the present invention (A) (b) Operation waveform diagram of pump drive unit Sectional drawing of the dishwasher in Embodiment 5 of this invention (A)-(C) Waveform diagram during the washing process of the dishwasher (A) ~ (C) Waveform diagram of the dishwasher during drainage Cross-sectional view of a conventional dishwasher Waveform diagram of the dishwasher

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 AC power supply 11 Induction motor 12 Phase advance capacitor | condenser 17 Electric quantity detection means 18 Foam biting determination means 30, 31 Winding 89 Power supply frequency detection means 110 Pump apparatus 114 Water supply means

Claims (8)

A phase advance capacitor, an induction motor having a plurality of windings including a series connection of the phase advance capacitor, an electric quantity detection means for detecting a current flowing in at least one winding, and a bubble biting determination means The bubble biting determination means receives a signal including a harmonic component that increases when the bubble bites from the electric quantity detection means, and the ratio of the harmonic component to the fundamental wave component of the electric quantity detection means is equal to or greater than a predetermined value. A pump device that determines whether or not a bubble has been caught. 2. The pump device according to claim 1, wherein the amount of electricity detected by the amount of electricity detecting means is a current flowing in a series circuit of a winding of the induction motor and a phase advance capacitor. The pump device according to claim 1, wherein the amount of electricity detected by the amount of electricity detecting means is a current flowing through a winding of an induction motor not connected to a phase advance capacitor. The pump device according to claim 1, wherein the amount of electricity detected by the amount of electricity detecting means is a current supplied from an alternating current power source to the induction motor. A phase advance capacitor, an induction motor having a plurality of windings including a winding in which the phase advance capacitor is connected in series, an electric quantity detection means for detecting a potential at a connection point of the phase advance capacitor and the winding, and bubble biting The bubble biting determination unit receives a signal including a harmonic component that increases when the bubble is bitten from the electric quantity detection unit, and the ratio of the harmonic component to the fundamental wave component of the electric quantity detection unit is A pump device that determines whether or not a foam is caught when a predetermined value or more is reached . The pump according to any one of claims 1 to 5 , further comprising a power source frequency detecting means for detecting a frequency of the AC power source, wherein the threshold value for bubble biting determination is changed corresponding to at least two AC power source frequencies. apparatus. A dishwasher comprising the pump device according to any one of claims 1 to 6 and once stopping the induction motor when the bubble biting is determined. A dishwasher comprising the pump device according to any one of claims 1 to 6 and a water supply means, wherein the water supply means performs a water supply operation when a bubble biting determination is made.