JP2008113978A - Washing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive and secure detection means for detecting abnormal occurrence of bubbles during washing caused by the excessive charge of a detergent. <P>SOLUTION: The washing machine includes: a pair of electrodes (C1, C2); a transformer (T) connected with the electrodes; bubble detection means (R3, C, OP1) electrically insulated by the transformer (T) for converting the resistance change between electrodes to oscillation frequency change and outputting it; and a control means for controlling a series of washing operations. When detecting the bubbles, the control means controls water supply and water discharge. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a washing machine having a clothes drying function and having a drum having a central axis of rotation in a horizontal direction or an inclination direction.

  Patent Document 1 describes a drum type washing machine that detects foam using a pressure sensor and executes a process of eliminating the foam.

  Patent Document 2 describes a washing machine in which a pair of electrodes that are electrically insulated from a commercial power source are provided in the upper part of the outer tub, and the generated foam is detected and a process for removing the detected foam is executed. In this washing machine, electrical insulation is performed by a transformer, an AC signal source connected to a power source obtained by rectifying and smoothing a 100V commercial power source is connected to the primary side of the transformer, and this AC signal source signal is connected to the secondary side. The rectifying / smoothing circuit and the detection circuit to which the electrodes are connected are provided, and the power supply of the detection circuit itself is insulated from the commercial power supply of 100V.

Japanese Patent Laid-Open No. 2002-166093 JP 2001-293287 A

  In the drum type washing machine described in Patent Document 1, the sensitivity of the pressure sensor detects the pressure of a very small bubble. In such a detection device, there are generally problems such that detection is likely to vary depending on the state of the bubble (the size of the bubble) and that it takes time to detect.

  From the viewpoint of detection time, an apparatus that detects the presence of bubbles by resistance between electrodes is preferable. In this case, it is necessary to consider electric insulation such as disconnecting the electrode from the commercial power source.

  In the foam detection apparatus described in Patent Document 2, an electrode attached to the outer tub is separated from a commercial power source using a transformer. However, in Patent Document 2, considerations regarding circuit simplification are not sufficient.

  An object of the present invention is to detect the generation of bubbles at a low cost with a simple circuit configuration.

  To achieve the above object, according to the first aspect of the present invention, there is provided a transformer, a pair of electrodes connected to a primary coil of the transformer, and a resistance between the pair of electrodes appearing in a secondary coil of the transformer. A detection means comprising a converted conversion resistor and an oscillation circuit whose oscillation frequency is determined by a capacitor is provided, and the pair of electrodes are arranged in an outer tank (water receiving tank) or a part communicating with the outer tank, and a detergent between the electrodes It is configured to detect the presence of water or bubbles containing liquid.

  Further, in the invention according to claim 2, in claim 1, the water supply means for supplying water into the outer tub, the drain means for draining the water in the outer tub, a series of washing operations, the water supply means, and the drain means. Control means for controlling, and the control means detects a resistance value between the pair of electrodes to control the washing operation and the water supply means and drainage means.

  According to a third aspect of the present invention, in the first aspect, the turn ratio of the primary coil and the secondary coil of the transformer is N to 1 and N is 5 or more when the presence of bubbles is detected. In the case of detecting the presence of water containing liquid, 1 to N and N is 2 or less.

  In order to achieve the above object, in the invention according to claim 4, a drum having a central axis of rotation in a horizontal direction or an inclined direction, an outer tub containing the drum and elastically supported by a washing machine body, Water supply means for supplying water into the outer tub, drainage means for draining water in the outer tub, a pair of electrodes provided at the lowest part of the outer tub, and washing by detecting a resistance value between the pair of electrodes And a detergent concentration detecting means for detecting the detergent concentration of water. The detergent concentration detecting means detects the detergent concentration at the time of supplying the detergent after the detergent is added and the detergent is dissolved and stirring. After the part is drained and again supplied with water to dilute to a predetermined concentration of detergent solution, washing and stirring are started.

  In order to achieve the above object, in the invention according to claim 5, a drum having a central axis of rotation in a horizontal direction or an inclined direction, an outer tub enclosing the drum and elastically supported by a washing machine body, A pair of water supply means for supplying water into the outer tub, drainage means for draining the water in the outer tub, drive means for rotationally driving the drum, and a pair of drums facing the upper surface center of the outer periphery of the outer tub. Electrodes, foam detection means for detecting a change in resistance between the pair of electrodes and detecting the presence of foam between the outer tub and the drum, a series of washing operations, the water supply means, the drainage means, and the drive means, And a control means for controlling the operation, and when the foam detection means detects foaming between the outer tub and the drum during rotation of the drum, the control means stops the driving means and supplies water into the outer tub. Is.

  In order to achieve the above object, in the invention according to claim 6, a drum having a central axis of rotation in a horizontal direction or an inclined direction, an outer tub containing the drum and elastically supported by a washing machine body, Water supply means for supplying water into the outer tub, drainage means for draining water in the outer tub, drive means for rotationally driving the drum, hot air generating means for drying laundry, A hot air blowing path leading into the front surface of the outer tub, a dehumidification path for dehumidifying the hot air discharged from the outer tub and sending it to the hot air generating means, a water injection means for injecting water into the dehumidification path, and the dehumidification A pair of electrodes provided in the path; foam detection means for detecting foam intrusion into a deep portion in the dehumidification path from a change in resistance between the pair of electrodes; a series of washing and drying operations; the water supply means and drainage means , Drive means, hot air generation means, water injection means Control means for draining wash water in the outer tub with the drainage means when the foam detection means detects foam intrusion into the dehumidification path, and the water injection means within the dehumidification path. Water is poured into the water.

  According to the washing machine of claim 1, the electrodes installed in the outer tub can be electrically insulated by the transformer. Since the transformer does not transmit power but only transmits signals, it is inexpensive because a thin wire (0.05 mm diameter) enameled wire wound around a ferrite core material may be used. The change in interelectrode resistance due to the presence of water or bubbles changes the oscillation frequency. If this oscillation signal is shaped into a rectangular wave, it can be directly connected to a terminal such as a microcomputer, and a control unit for the washing machine centered on the microcomputer can be used. Can be configured at low cost. Further, since it is a digital signal (rectangular wave), the noise resistance performance is greatly improved.

  According to the washing machine of claim 2, when the foam is detected, the control means stops the washing operation (for example, rotation of the drum, etc.) and drains the washing water containing a large amount of foam in the outer tub by controlling the drainage means. To do. Then, tap water is supplied into the outer tank by the water supply means, and bubbles are poured out. After this defoaming process, the process proceeds to the next step. For this reason, abnormal foam generation becomes a problem, and the problem that washing is not completed is solved.

  According to the washing machine of the third aspect, the resistance range in a state where each electrode is placed can be accurately converted into a frequency change, and the state where the electrode is placed can be accurately determined from this frequency. And the detection accuracy of the presence of water or foam containing a detergent solution can be improved, and abnormal foam generation becomes a problem, and the problem that washing is not completed is solved.

  According to the washing machine of the fourth aspect, foaming can be prevented beforehand by diluting the detergent in advance and starting the washing operation at the specified concentration with respect to excessive detergent addition. And the amount of defoaming water and operation time can be reduced by the foaming elimination operation in the subsequent process.

  According to the washing machine of the fifth aspect, foaming between the drum and the outer tub can be detected even at a low-speed rotation in the initial stage of dewatering. Furthermore, it is difficult to detect foaming due to overcurrent, and it is possible to detect foam intrusion to the uppermost part between the drum outer tubs even during washing where the required torque of the motor is large, that is, when driving with a large current. When the motor is rotated at a very low speed and foaming is detected, the drainage means is opened, and the water between the tanks is washed away while water is supplied by the water supply means. After this defoaming treatment, dehydration is resumed and the process proceeds to the next step after completion. For this reason, abnormal foam generation becomes a problem, and the problem that washing is not completed is solved.

  According to the washing machine of claim 6, by detecting foam with a pair of electrodes provided in the dehumidification path, the drainage means is opened to supply water into the drum from the water supply means, and the foam in the dehumidification path is also supplied from the water inlet. Wash it with water. This prevents bubbles from entering the hot air generating means. As a result, it is possible to prevent bubbles from adhering to the heater, fan motor, etc. in the hot air generating means.

  Hereinafter, embodiments of the washing machine will be described.

  The washing machine of the present invention oscillates with a transformer, a pair of electrodes connected to the primary coil of the transformer, and a conversion resistor and a capacitor that appear in the secondary coil of the transformer and in which the resistance between the pair of electrodes is converted. A foam detection means comprising an oscillation circuit with a determined frequency is provided, and the pair of electrodes are arranged in an outer tank (water receiving tank) or a part communicating with the outer tank so as to detect the presence of water or bubbles between the electrodes. Configured.

According to this, the electrode installed in the outer tub can be electrically insulated by the transformer. Since the transformer does not transmit power but only transmits signals, it is inexpensive because a thin wire (0.05 mm diameter) enameled wire wound around a ferrite core material may be used. The change in interelectrode resistance due to the presence of water or bubbles changes the oscillation frequency. If this oscillation signal is shaped into a rectangular wave, it can be directly connected to a terminal such as a microcomputer, and a control unit for the washing machine centered on the microcomputer can be used. Can be configured at low cost. Further, since it is a digital signal (rectangular wave), the noise resistance performance is greatly improved.

  The control means comprises water supply means for supplying water into the outer tub, drainage means for draining the water in the outer tub, and a control means for controlling a series of washing operations, the water supply means and the drainage means, The foam detection means detects the generation of abnormal bubbles from the change in resistance value between the pair of electrodes, and controls the washing operation and the water supply means and drainage means.

  According to this, when the foam is detected, the control means stops the washing operation (for example, rotation of the drum, etc.), and controls the drainage means to drain the washing water containing a large amount of foam in the outer tub. Then, tap water is supplied into the outer tank by the water supply means, and bubbles are poured out. After this defoaming process, the process proceeds to the next step. For this reason, abnormal foam generation becomes a problem, and the problem that washing is not completed is solved.

  Further, the winding turns ratio of the primary coil and the secondary coil of the transformer is N to 1 and N is 5 or more when detecting the presence of bubbles, and 1 when detecting the presence of water containing detergent solution. The pair N and N were configured to be 2 or less.

During the washing process, the electrode is placed in tap water, detergent solution, surrounded by bubbles, or placed in the air. And resistance R between electrodes changes greatly in each state. For example, if the distance between electrodes (30 mm) is 2 kΩ in tap water, it is 1 kΩ or less (depending on the concentration of the detergent solution) in detergent solution, and the type of detergent (manufacturer or weak alkaline detergent or liquid neutral) in the case of foam Depending on the detergent), it is 10 kΩ to several hundred kΩ, and several tens of MΩ in the atmosphere. According to this, the resistance range in the state where each electrode is placed can be accurately converted into a frequency change, and the state where the electrode is placed can be accurately determined from this frequency. And detection accuracy can be improved, the problem that abnormal bubble generation | occurrence | production becomes a problem and washing is not completed is solved.

  A drum having a central axis of rotation in a horizontal direction or an inclined direction; an outer tub containing the drum and elastically supported by a washing machine body; water supply means for supplying water into the outer tub; Drainage means for draining water, a pair of electrodes provided in the lowest part of the outer tub, and a detergent concentration detection means for detecting a detergent concentration of the washing water by detecting a resistance value between the pair of electrodes, The detergent concentration is detected by the detergent concentration detection means when the detergent is supplied and the detergent is dissolved and stirred. If the detergent concentration is equal to or higher than the predetermined concentration, the stirring is stopped, a part is drained, and the water is diluted again by supplying water again. Start washing and stirring after the detergent solution is formed.

  A pair of electrodes is provided at the lowest part of the outer tub. The detergent put in the detergent case opens the water supply means to start water supply, and uses a part of the water supply to guide the detergent to the water reservoir at the lowest part of the outer tub provided with a pair of electrodes. Then, the detergent in the lower part of the outer tub is stirred and dissolved while rotating the drum at a low speed. At this time, the detergent concentration is detected by measuring the resistance between the previous electrodes by the detergent concentration detecting means. When this detergent concentration is higher than a predetermined value, stirring is stopped, the drainage means is opened, and the detergent liquid is discharged. This discharged amount is calculated from the amount of water necessary for the capacity of the inputted laundry and the detected detergent concentration. After discharging a predetermined amount of detergent liquid, the drainage means is closed, and the water supply means is opened again to supply water only to compensate for the amount of discharged water. Thus, after the detergent liquid is adjusted to the specified concentration (no excessive foaming), the cleaning operation is started.

  Thus, foaming can be prevented beforehand by diluting the detergent in advance and starting the washing operation at a specified concentration against excessive detergent input. And the amount of defoaming water and operation time can be reduced by the foaming elimination operation in the subsequent process.

  A drum having a central axis of rotation in a horizontal direction or an inclined direction; an outer tub containing the drum and elastically supported by a washing machine body; water supply means for supplying water into the outer tub; Drainage means for draining water, drive means for rotationally driving the drum, a pair of electrodes provided near the center of the upper surface of the outer periphery of the outer tub, and a change in resistance value between the pair of electrodes is detected And foaming detection means for detecting the presence of foam between the outer tub and the drum, and control means for controlling a series of washing operations and the water supply means, drainage means, and drive means. Then, when foaming is detected by the foaming detection means during the rotation of the drum, the control means stops the driving means and drains the washing water in the outer tub or supplies water into the outer tub.

  Foam generated in the drum during washing enters the space between the drum and the outer tub from the dewatering hole of the drum. Since the water level in the drum is low, bubbles rarely reach the top of the outer tub. However, if an excessive amount of detergent is added, the drum may be filled with foam even during cleaning, and the foam may penetrate to the top of the outer tub.

  The foam between the drum and the outer tub becomes a problem when dewatering after washing or rinsing. When the drum is rotated in one direction for dehydration, the foam is stirred and further foaming is promoted. At the same time, the foam turns into a fine, viscous cream that fills everything between the drum and the outer tub. Due to the bubbles, the motor rotation is inhibited and dehydration is impossible. That is, the detergent liquid cannot be removed from the laundry by centrifugal force.

  In recent years, in order to increase the capacity of washing machines and to reduce noise by direct driving of drums, motors that rotate drums have been increasing in torque and current. For this reason, it is difficult to detect an overcurrent at a low drum rotation, that is, at a low-speed current (overcurrent value at a normal low-speed rotation). For this reason, overcurrent is detected at a certain high speed. However, the detection at high speed causes excessive foaming between the drum and the outer tub, making it difficult to perform the defoaming operation by stopping the drum rotation.

  A pair of electrodes is provided in the vicinity of the center of the upper surface of the outer periphery of the outer tank in order to detect foaming between the drum and the outer tank. For this reason, it is not necessary to detect the foaming by detecting the overcurrent by rotating the drum, that is, the motor at a high speed. As a result, the foam is stirred at a high speed and foaming is further promoted. At the same time, the foam is changed into a fine and highly viscous cream, and the subsequent foam erasing process is not difficult. When the motor is rotated at a very low speed and foaming is detected, the drainage means is opened, and the water between the tanks is washed away while water is supplied by the water supply means. After this defoaming treatment, dehydration is resumed and the process proceeds to the next step after completion. For this reason, abnormal foam generation becomes a problem, and the problem that washing is not completed is solved.

  If foaming is directly detected by the electrode installed at the uppermost part between the drum outer tanks, foaming between the drum and the outer tank can be detected even at a low speed rotation in the initial stage of dewatering. Furthermore, it is difficult to detect foaming due to overcurrent, and it is possible to detect foam intrusion to the uppermost part between the drum outer tubs even during washing where the required torque of the motor is large, that is, when driving with a large current.

  A drum having a central axis of rotation in a horizontal direction or an inclined direction; an outer tub containing the drum and elastically supported by a washing machine body; water supply means for supplying water into the outer tub; Drainage means for draining water, drive means for rotating the drum, hot air generating means for drying laundry, a hot air blowing path for guiding warm air into the front surface of the outer tub, and the outer tub A dehumidification path for dehumidifying the hot air discharged from the inside and sending it to the hot air generating means, a water injection means for injecting water into the dehumidification path, a pair of electrodes provided in the dehumidification path, and between the pair of electrodes Foam detection means for detecting the invasion of foam into the dehumidification path deep from the resistance value change, and a series of washing and drying operations and the water supply means, drainage means, drive means, hot air generation means, water injection means are controlled. Control means, and the defoaming means by the foam detection means When detecting bubbles entering the to water injection drainage and dehumidifying the path of the washing water in the outer tub.

  By detecting bubbles with a pair of electrodes, further intrusion of bubbles is prevented.

  As for the drying function, the discharge port of the hot air blowing path is provided at the front upper side of the outer tank (water receiving tank), and the hot air intake port of the dehumidification path is provided below the rear surface of the outer tank. This is because hot air is blown from the top of the drum to the clothing, and after warming the clothing, the warm air that has become heavier as the temperature has dropped and taken in from the bottom of the drum is dehumidified and then sent back to the hot air generating means to increase drying efficiency. It is to do. Since it is this structure, the foam which arises during washing becomes easy to penetrate | invade from the intake of a dehumidification path | route with a raise of a water level. Water containing detergent tends to foam, and the foam has a low resistance due to the detergent components. In the case where a heater, a fan motor or the like is arranged in the hot air generating means, measures against the bubbles are required.

  Further, a pair of electrodes is provided in the dehumidification path, and the intrusion of bubbles into the dehumidification path is detected from the resistance change between the electrodes. Then, the drainage means is opened, and water is supplied into the drum from the water supply means, and water is also applied to the foam in the dehumidification path from the water injection port to wash it out. This prevents bubbles from entering the hot air generating means.

  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.

  The construction of the washing machine will be described with reference to FIGS. 1 to 4 for the first embodiment of the present invention. As shown in FIG. 1, a door 2 is provided at the center of the front surface of the outer frame 1 that forms the outer shell of the drum-type washing and drying machine, and various switches including various indicators and a power switch are provided at the top. The operation panel 3, the drawer type detergent box 4 into which the detergent and the softening agent are put, and the drawer type lint filter box 5 that collects lint from the clothes generated during drying are provided. As shown in FIG. 2, the door 2 opens and closes a laundry doorway 7 formed at the center of the front portion of the outer frame 1, and an operation circuit portion 8 is provided on the back side of the front portion of the outer frame 1. Is provided with a control circuit unit 9.

  An outer tub 10 is disposed inside the outer frame 1. The outer tub 10 is a water receiving tub, has a cylindrical shape, and has a horizontal axis shape in which the axial direction is front and rear (right and left in the figure). It is supported from the bottom part, and the front part is arranged in an upwardly inclined shape. Inside the outer tub 10, the drum 12 is disposed coaxially with the outer tub 10. The drum 12 functions as a shared tank for washing, dehydration and drying, and a large number of small holes 13 are formed in almost the entire body. (Only a part is shown in FIG. 2) and a plurality of baffles 13 (only one is shown in FIG. 2) are provided on the inner periphery.

  Both the outer tub 10 and the drum 12 have openings 14 and 15 for putting in and out the laundry on the front surface, and the opening 14 of the outer tub 10 is connected to the laundry entrance 7 of the outer frame 1 by a bellows 16 in a watertight manner. Twelve openings 15 face the opening 14 of the outer tub 10. A fluid balancer 17 is disposed around the opening 15 of the drum 12.

  A brushless motor 20 that rotationally drives the drum 12 is disposed on the back surface of the outer tub 10. The brushless motor 20 is an inner rotor type, and a stator is fixed to the outer periphery of a bearing portion 21 attached to the center of the back portion of the outer tub 10. A rotation shaft 22 attached to the center of the rotor is inserted into the bearing portion 21 and is rotatably supported. The center of the back portion of the drum 12 is attached to the front end portion of the rotating shaft 22 that protrudes from the bearing portion 21 into the outer tub 10.

A water reservoir 25 is attached to the bottom of the outer tub 10. The water reservoir 25 is provided with a pair of electrodes A1 and A2 penetrating the water reservoir 25 at its rear part, and a drain hose 27 is connected to the lowermost part of the rear part via a drain valve 26. The drain valve 26 is an electric type whose valve is opened and closed by a solenoid or a motor. In addition, an air chamber 28 communicating with the water reservoir 25 is provided beside the water reservoir 25, and a water level sensor 30 is connected to the air chamber 28 via a tube 29.

  In the vicinity of the upper center of the outer tub 10, electrodes B1 and B2 are provided. This electrode penetrates the outer tub 10 and faces the outer periphery of the drum 12 so that the electrode tip does not contact the outer periphery of the drum 12.

  On the upper surface portion of the outer tub 10, a blower unit 35 and a heating unit 45 are disposed in the outer frame 1 while being fixed to the outer frame 1.

  The air blower 35 is configured such that a blade 37 is rotatably provided in the casing 36, and the blade 37 is rotated by a fan motor 38 provided outside the casing 36.

  The heating part 45 is provided with a PTC heater 47 for hot air inside the casing 46, and the inlet part of the casing 46 communicates with the discharge part 39 of the blower part 35. An outlet 48 of the heating unit 45 is connected to one end of a heat resistant rubber bellows 49.

  A blower duct 50 is provided on the front surface of the outer tub 10, one end is connected to the outlet 48 of the heating unit 45 via a heat-resistant rubber bellows 49, and the other end is a peripheral portion of the opening 14 of the outer tub 10. Is desired through the opening 14 of the drum 10.

  As shown in FIG. 3, a water-cooled dehumidifying duct 55 is disposed on the back surface of the outer tub 10. The water-cooled dehumidifying duct 55 is designed to dehumidify the water in the air passing through the interior by exchanging heat by water injection, cooling and condensing it by pouring water from above. Water injection from the upper part is performed from the water-cooling / dehumidifying water injection port 57. The water-cooled dehumidifying duct 55 is hollow and has a plurality of ribs 56 disposed in the middle. The injected water stays in the ribs 56 and is wound up by the wind of the blower fan 38 to form water droplets so that the heat exchange described above is performed efficiently. The water-cooled dehumidifying duct 55 has a shape that is concentrically curved with respect to the rotating shaft 22 of the brushless motor 20 that is the rotation center of the drum 12, and is disposed as shown in FIG. 3, avoiding the brushless motor 20.

A water-cooled dehumidifying water inlet 57 is provided in the upper part of the duct, and a pair of horizontally disposed electrodes C1 and C2 are provided downstream of the water inlet so as to project through the duct wall surface and into the water-cooled dehumidifying duct 55. ing. This electrode is provided to detect bubble intrusion into the water-cooled dehumidifying duct 55. Detailed operation will be described later. The vertical height of the electrodes C1 and C2 is preferably approximately the height of the connection portion of the air duct 50 to the outer tub 10. This is because the height of the foam in the duct 55 is almost the same as the height of the foam in the drum 12, and the foam reaches the connection portion of the air duct 50 to the outer tub 10 and enters the air duct from here. This is to detect. In the figure, the electrodes C1 and C2 are arranged in the horizontal direction, but they may be arranged in the vertical direction. Furthermore, it is desirable that the electrodes C1 and C2 be installed substantially vertically below the water-cooled dehumidifying water injection port 57 and be washed with water-cooled dehumidified water.

The water-cooled dehumidifying duct 55 has a water outlet / air inlet 58 at the lower part and an air outlet 59 at the upper part. The water outlet / air inlet 58 is communicated with the lowermost part of the outer tub 10 and the air outlet 59 is connected to the lint filter. The inlet 60 of the duct 60 is connected via a rubber bellows 62. The outlet portion 63 of the duct 60 communicates with the lint filter box 5, and a drawer type lint filter (not shown) is built in the box 5. The outlet part 65 of the lint filter box 5 communicates with the duct 66, and the other end of the duct 66 communicates with the suction port 40 of the blower part 35.

The drying function blows the warm air generated by the air blowing unit 35 and the heating unit 45 into the drum 12 from the opening 14 (front upper side) of the outer tub 10 through the air duct 50 communicating with the front surface of the outer tub. The hot air containing the superheated steam is taken in from the water outlet / air inlet 58 (below the rear surface of the outer tub 10) provided in the lower part of the water-cooled dehumidifying duct 55, and heat exchange is performed by water injection while passing through the water-cooled dehumidifying duct 55. This is achieved by cooling, condensing and dehumidifying. The water-cooled and dehumidified air is sucked into the suction port 40 of the blower 35 from the air outlet 59 through the duct 60, the lint filter box 5 and the duct 66. Then, it is again heated by the heating unit 45 to be heated and circulated through the drum 12.

Due to the configuration of the drying function, bubbles generated during washing easily enter the water-cooled dehumidifying duct 55 from the water outlet / air inlet 58 as the water level rises. Water containing detergent tends to foam, and foam has low resistance due to the detergent component. Therefore, the foam penetrates into the circulation path and adheres to electrical parts such as the PTC heater 47 and the fan motor 38, thereby causing an electrical short circuit and corrosion. Care must be taken not to wake up.

  As shown in FIG. 4, a main water supply valve 71, a softener water supply valve 72, and a dehumidification water supply valve 73 having one water supply tap 70 in common are arranged at the corner of the inner upper left side (upper left in the drawing) of the outer frame 1. . The faucet is connected to a faucet with a hose (not shown). These valves are electrically operated like drain valves.

  A detergent box 4 is disposed in front of each of the water supply valves 71, 72, 73 (lower left in the figure). The detergent box 4 has a first tap water supply path to which a hose from the main water supply valve 71 is connected and a second tap water supply path to which a hose from the sofner water supply valve is connected, and is a drawer type. The detergent case is inserted. The outlets of the respective supply paths are in common and communicate with the outer tub 10 from above.

  The outlet of the main water supply valve is connected by a hose to the first tap water supply path of the detergent box. The outlet of the sofner water supply valve 52 is connected to the second tap water supply path of the detergent box by a hose. The dehumidified water supply valve 73 is connected to the dehumidified water injection port 57 by a hose.

  The configuration of the first embodiment of the present invention has been described above. Next, the circuit configuration of this embodiment will be described.

  The operation panel 3 is provided with various displays and various switches including a power source, and these are connected to the operation circuit unit 8. The switch selects execution of each process of washing, rinsing, dehydration, and drying, and each indicator displays the amount of detergent, the amount of water, or the time, progress, and abnormality of each process.

  FIG. 5 shows a control circuit unit 9 mainly composed of a microcomputer 90 (hereinafter referred to as a microcomputer). This functions as a control means for controlling the overall operation of the washing machine. The microcomputer 90 receives operation signals from various switches including the power switch of the operation panel. Then, the operation setting value corresponding to the user's operation signal, the amount of necessary detergent, the amount of water, or the time, progress state, abnormality, etc. of various processes are output to the respective displays or buzzers.

Moreover, the water level signal of the water level sensor 30 which detects the water level in the outer tank 10 which is a water receiving tank is input. Then, detection signals of the foam detection circuit A91, the foam detection circuit B92, and the detergent concentration detection circuit 94 according to the present invention are input. The power supply circuit 95 directly rectifies and smoothes the commercial power supply and supplies DC power necessary for the microcomputer 90 and other circuits. For this reason, the DC power supply of the microcomputer 90 and other circuits is superimposed on the commercial AC power supply.

  The microcomputer 90 controls each motor operated valve and each motor based on these input signals and a previously stored control program. The microcomputer 90 energizes the PTC heater 47, the main water supply valve 71, the softener water supply valve 72, the dehumidified water water supply valve 73, and the drain valve 26 through each control circuit 96 to control heating or valve opening / closing. The microcomputer 90 controls the rotational speed of the blower fan motor 38 via the blower fan control circuit 98 to vary the air volume. Further, the microcomputer 90 controls the rotational direction and the rotational speed of the brushless motor 20 that rotationally drives the drum 12 via the motor drive circuit 99.

  In this embodiment, the electrodes connected to the foam detection circuit A91, the foam detection circuit B92, and the detergent concentration detection circuit 94 are immersed in the washing liquid or the foam of the washing liquid during the operation of the washing machine. For this reason, a transformer is provided between the electrode and the circuit energization unit to electrically separate the circuit.

  FIG. 6 shows details of the foam detection circuit B92. FIG. 7 shows a CR oscillation circuit using an operational amplifier. The oscillation frequency of the circuit of FIG. 7 is determined by the resistor R and the capacitor C as is well known. The foam detection circuit B is obtained by replacing the resistor R with a transformer T.

  The electrodes C1 and C2 are connected to the primary coil L1 of the transformer T. The operational amplifier OP1 constitutes a CR oscillation circuit, and the resistance R between the electrodes is almost determined by the value of the resistance R1 converted by the transformer and the capacitor C. When the turns ratio of the primary coil L1 and the secondary coil L2 is N to 1, the resistance R1 converted to the secondary side is 1 / N 2.

  By making the number of turns of the primary coil L1 and the secondary coil L2 larger in the primary coil L1 than in the secondary coil L2, it is possible to reduce the bubble conversion resistance and stabilize the circuit operation. .

  The resistor R2 is for preventing the circuit operation from becoming unstable when the secondary coil L2 of the transformer T is disconnected, and is set to a value sufficiently larger than the value of the conversion resistor R1. This value determines the lower limit oscillation frequency of the circuit. The resistor R3 is also for stabilizing the circuit operation at a high oscillation frequency (for example, when the electrodes are short-circuited), and is set to a value sufficiently smaller than the value of the conversion resistor R1. This value determines the upper limit oscillation frequency of the circuit.

  The oscillation signal is waveform-shaped by the operational amplifier OP2 and input to the port terminal of the microcomputer 90 as a rectangular wave signal. Thus, the foam detection circuit B92 converts the resistance value change between the electrodes into a frequency change and outputs it.

  In the case of foam, the resistance between the electrodes varies from 10 kΩ to several hundred kΩ depending on the type of detergent (manufacturer or weak alkaline detergent or liquid neutral detergent). The resistance of the bubble is reduced to 1 / N 2 with a transformer, and the oscillation frequency is determined by the resistance and the capacitor. Further, it is necessary to sufficiently increase the inductance of the primary coil L1 to which the electrode is connected within the range of the oscillation frequency so as to meet the resistance. For example, it is preferable to wind a coil around a ferrite core so that the inductance of L1 is 1H or more.

  An example of the relationship between the interelectrode resistance R and the oscillation frequency of the foam detection circuit B92 is shown in FIG. This characteristic is obtained when the number of turns of the transformer is 1250 turns (L1): 250 turns (L2). The turn ratio is 5: 1. The frequency changes linearly when the electrode is surrounded by bubbles (from 10 kΩ to several hundred kΩ). If a predetermined frequency threshold value is set within this range, the electrode is surrounded by bubbles or underwater. (Upper limit frequency side) or in the atmosphere (lower limit frequency) can be accurately detected.

  The foam detection circuit A91 has the same configuration as the foam detection circuit B92, and the transformer to which the electrodes B1 and B2 are connected is the same.

During the washing process, the electrode is placed in tap water, detergent solution, surrounded by bubbles, or placed in the air. And resistance R between electrodes changes greatly in each state. For example, if the distance between electrodes (30 mm) is 2 kΩ in tap water, it is 1 kΩ or less (depending on the concentration of the detergent solution) in detergent solution, and the type of detergent (manufacturer or weak alkaline detergent or liquid neutral) in the case of foam Depending on the detergent), it is 10 kΩ to several hundred kΩ, and several tens of MΩ in the atmosphere.

  The detergent concentration detection circuit 94 has the same circuit configuration as the foam detection circuit B92. However, the turns ratio of the transformer T is changed. The oscillation frequency range of the oscillation circuit is limited due to the frequency characteristics of the operational amplifier used. On the other hand, as described above, in order to change the frequency so that both water (including detergent liquid) and the presence of bubbles can be discriminated, the frequency range of the oscillation circuit needs to be three digits or more. However, an oscillation circuit composed of an inexpensive operational amplifier is limited to oscillation in a frequency range of about one digit. Therefore, the oscillation frequency range is changed by changing the turns ratio of the transformer.

  In the detergent concentration detection circuit 94, the number of turns of the primary coil L1 of the transformer T is 125 turns and the number of turns of the secondary coil L2 is 250 turns so that the concentration of the detergent solution can be detected. Contrary to the case of detecting bubbles, the resistance of the detergent solution is quadrupled so that the oscillation frequency can be determined by the resistance and the capacitor. FIG. 8B shows an example of the characteristics of the detergent concentration detection circuit. The frequency changes linearly when the electrode is in tap water or detergent solution (100Ω to 2 kΩ), and the detergent concentration can be detected from the frequency within this range. If the electrode is surrounded by bubbles or in the atmosphere, the lower limit frequency is set.

  As described above, the electrodes that are installed in the outer tank to detect foaming or detergent concentration are electrically insulated by the transformer, so the commercial power supply is superimposed on the power supply voltage of the control unit. This is also applicable to the case where the power supply circuit of the device is usually superposed on the power supply voltage of the control unit to directly rectify the commercial power supply in order to reduce the power supply circuit of the device. Since the transformer does not transmit power but only transmits signals, it is inexpensive because a thin wire (0.05 mm diameter) enameled wire wound around a ferrite core material may be used. In addition, the change in inter-electrode resistance due to the presence of water (including detergent) or bubbles results in a change in the oscillation frequency. This oscillation signal is shaped into a rectangular wave and can be directly connected to the microcomputer terminals, making the control unit inexpensive. Can be configured. Further, since it is a digital signal (rectangular wave), the noise resistance performance is greatly improved.

  Next, the operation of this embodiment will be described.

  First, an outline process will be described. FIG. 9 shows a schematic flowchart of the standard course of the washer / dryer. First, when the user turns on the power switch and the operation of the standard course is started, washing of the laundry, two intermediate dehydrations and rinsing, final dehydration, and drying are sequentially performed. First, the amount of laundry is detected (step S1). After supplying necessary tap water (step S2), washing (step S3) is performed and the washing water is drained (step S4). Thereafter, in order to squeeze out the detergent contained in the laundry, first intermediate dehydration is performed (step S5), and water supply is started again for the first rinse (step S6). When the first rinse (step S7) is completed, the rinse water is drained (step S8). Thereafter, in order to squeeze out the detergent still contained in the laundry, a second intermediate dehydration (step S9) is performed, and water supply is started again for the second rinse (step S10). When the second rinse (step S11) is completed, the rinse water is drained (step S12), and final dewatering (step S13) is performed. Finally, drying (step S14) is performed, and washing and drying are completed.

  Hereinafter, the washing operation of the present embodiment will be described in detail with reference to a flowchart.

  FIG. 10 is a flowchart of a detergent liquid dilution process for preventing abnormal foaming caused by excessive detergent input by the user. When the user puts laundry into the washing machine and the power switch is pressed, first, cloth amount detection is performed to measure the amount of laundry put in (step S1). Then, the process which the detergent thrown in by the user is transferred into the outer tub 10 together with tap water and dissolved is performed. The microcomputer 90 first closes the drain valve 26 (step S2-1) and opens the main water supply valve 71 (step S2-2). By opening the main water supply valve 71, tap water passes through a connection hose (not shown) and is supplied into the outer tub 10 together with the detergent put into the detergent case (not shown) in the detergent box 4, and further. It is supplied into the drum through a small hole in the drum 12 and supplied to the water reservoir 25. The drum is rotated left and right in small increments according to the water supply, and the detergent is dissolved and rotated to dissolve the detergent in the tap water supplied (step S2-3). During this time, the microcomputer 90 monitors the signal from the water level sensor 30 (step S2-4), and closes the main water supply valve 71 when it reaches a predetermined water level THAS that matches the amount of laundry obtained by the cloth amount detection. Water supply is stopped (step S2-5). Subsequently, the detergent concentration of the washing liquid (liquid obtained by dissolving the detergent in the supplied tap water) is detected by the detergent concentration detection circuit 94 to which the electrodes A1 and A2 are connected (step S2-6).

  FIG. 11 shows an output example of the detergent concentration detection circuit 94 in the melting and stirring step. The higher the detergent concentration, the higher the output frequency, that is, the lower the interelectrode resistance. The output frequency is approximately proportional to the detergent concentration. Based on the characteristics of the detergent concentration detection circuit 94 shown in FIG. 8B, the relationship between the detergent concentration and the output frequency is preliminarily stored in the microcomputer 90 and used for calculation of the detergent liquid discharge amount described below.

  Then, the washing liquid is compared with a standard concentration (concentration that suppresses foaming) THN (step S2-7). When the concentration is higher than the standard concentration, the washing liquid is diluted to prevent abnormal foaming in the washing process. First, from the detected detergent solution concentration and standard concentration, the amount of the current washing liquid to be discharged is calculated (step S2-8). For example, if the detergent solution concentration detected in 20 liters of washing liquid is twice the standard concentration, 10 liters of the washing liquid is discharged and 10 liters of tap water is re-supplied and diluted. Can be a concentration. That is, the discharge amount is calculated as 10 liters. It is desirable to calculate the discharge amount as the remaining detergent water level (THS1). Then, the drain valve 26 is opened (opened) to drain 10 liters of washing liquid (step S2-9). At this time, the microcomputer 90 monitors the signal of the water level sensor (step S2-10), and opens the drain valve 26 until the calculated washing liquid is drained. When the calculated detergent liquid is drained, the drain valve 26 is closed (step S2-11), the main water supply valve is opened (step S2-12), and the water level is monitored by the water level sensor (step S2-13) and drained. Supply 10 liters per minute. When the water supply ends, that is, when the first water level THS is reached, the main water supply valve 71 is closed (step S2-14), and the process proceeds to the next washing step.

  Thus, according to the present embodiment, when a large amount of detergent is introduced, the detergent solution is automatically diluted to the standard, and the process proceeds to the next washing process. It can be prevented, and it is economical because tap water, time, and electric power required for the defoaming process (described later) in the washing process can be reduced.

  FIG. 12 shows a flowchart of a washing process including detection of abnormal foaming and foam elimination processing. If the occurrence of bubbles is detected by the foam detection circuit A91 during the washing process, the microcomputer 90 executes a predetermined bubble erasing operation. The operation is, for example, draining the washing liquid in the outer tub 10 by opening the drain valve, supplying tap water into the drum 12, or reducing the rotational speed of the motor 20 to reduce the drum 12. It is to reduce the rotational speed (weak operation) or a combination of these. An example is shown in FIG.

  The washing process is performed by rotating the drum forward and backward at a predetermined number of rotations (for example, 50 rpm) for a predetermined time (for example, 20 seconds) with the stop interposed therebetween (step S3-1).

During washing of the laundry in the drum 12, the washing water containing the detergent generates foam by receiving the impact of the laundry that falls sequentially, and the foam is further formed under the foam by the laundry swallowing. When pushed up, the bubbles reach the inside of the outer tub 10 through the small holes 13 and the opening 15, and further into the water-cooled dehumidifying duct 55 communicating with the outer tub 10 through the lower water outlet / air inlet 58. C1 and C2 are reached.

At this time, the microcomputer 90 reads the output frequency of the foam detection circuit A91 connected to the electrodes C1 and C2 (step S3-2). When this output frequency becomes higher than the predetermined frequency THA (step S3-3), it means that the bubbles have reached the position of the electrodes C1 and C2 installed in the water-cooled dehumidifying duct 55, and the inside of the drum 12 In step S3-4, it is determined that the foaming is abnormal. If it is below THA, the washing process of rotating the drum forward and backward is continued until a predetermined time THTA (step S3-5), the washing process is terminated, and the number of defoaming processes performed is cleared (step S3- 18) Proceed to the next intermediate dehydration 1.

When abnormal foaming is detected, a foam erasing process is performed. First, the rotation of the drum 12 is stopped (step S3-6), the drain valve is opened (step S3-7), and the washing liquid is drained. While monitoring the signal from the water level sensor 30 (step S3-8), when all of the washing liquid is drained (when the water level reaches THR), the main water supply valve 71 is opened with the drain valve open, and tap water is placed in the drum. And the dehumidifying water supply valve 73 are also opened (step S3-9), and the bubbles in the water-cooled dehumidifying duct 55 are also poured out. At this time, the drum 12 is rotated forward and backward at a low speed (step S3-10) so that the tap water is evenly applied to the laundry with foam attached to the drum. This water supply is performed for a predetermined time T1 (step S3-11) to limit the amount of water supply. For example, 6 liters. Thereafter, the drain valve 26 is closed (step S3-12), and when water is supplied to the water level THAS1 lower than the water level THAS in the washing process while monitoring the water level sensor 30 (step S3-13), the main water supply valve 71 and the dehumidification water supply valve 73 are supplied. Is closed (step S3-14). Then, the number of the above-described foam erasing process is set (step S3-15). If the number is less than the predetermined value N1, the process returns to the state before the foam erasing process, that is, the normal washing process (step S3-16). . When the predetermined number of times, for example, 3 times is reached, in order to skip the next intermediate dehydration, an intermediate dehydration skip flag is set (step S3-17), and the number of defoaming processes performed is cleared (step S3-18). Then, proceed to the next intermediate dehydration step.

  FIG. 13 shows a flowchart of the drainage after washing and the subsequent intermediate dehydration process. At this time, the laundry still contains a lot of thick detergent solution, which is squeezed out by centrifugal dehydration, and is a process performed for the purpose of reducing the amount of water and time in the next rinsing process. As the drum 12 rotates, the foam remaining in the drum and the detergent contained in the laundry gradually flow out from the small holes 13 of the drum 12 into the space between the drum 12 and the outer tub 10 and are drained. However, if the amount of the foam is large and the concentration of the detergent liquid is high, the remaining detergent liquid and foam are stirred by the rotation of the drum 12, and foaming is promoted. At the same time, the foam turns into a fine and viscous cream and fills everything between the drum 12 and the outer tub 10. Due to the bubbles, the motor rotation is inhibited and dehydration is impossible. That is, the detergent liquid cannot be removed from the laundry by centrifugal force.

  Conventionally, abnormal foaming between the drum and the outer tub in this process is not detected directly by the presence of bubbles, but indirectly by a load (inhibiting rotation) on the motor that rotates the drum. It was. Specifically, it was detected by an abnormal increase in the motor current value at the rotational speed at which the foam turns into a fine and viscous cream, or an abnormally low increase rate in the rotational speed. In the present embodiment, in the same manner as detecting the presence of foam in the washing process, the drum and the outer tank are affected by the resistance change between the electrodes B1 and B2 provided at the uppermost part of the outer tank 10 in which the foam does not easily reach in the washing process. Direct detection of the presence of bubbles filling in between. For this reason, it is possible to detect that the entire space between the drum and the outer tub has been filled even before the dehydration initial low-speed rotation, that is, before the foam becomes creamy, and it becomes easy to eliminate the foam.

  First, in order to finish the washing process, the rotation of the drum is stopped (step S4-1). Thereafter, the drain valve 26 is opened (step S4-2), and all the washing water is drained while monitoring the water level with the water level sensor 30 (step S4-3). When drainage is completed, the intermediate dehydration skip flag is checked (step S5-1). If the flag is set, the intermediate dehydration step is skipped and the process proceeds to one rinsing step. If not standing, gradually increase the rotational speed of the drum in one direction from a low speed (for example, 30 rpm), and perform centrifugal dehydration at a high speed rotational speed RE (for example, 950 rpm) for a predetermined time (THTD) to remove the washing liquid contained in the laundry. Squeeze out.

While gradually increasing the rotational speed (step S5-2), the microcomputer 90 reads the output frequency of the foam detection circuit B92 connected to the electrodes B1 and B2 (step S5-3). When this output frequency becomes higher than the predetermined frequency THD (step S5-4), it is determined that abnormal foaming occurs (step S5-5), and the rotation of the drum 12 is temporarily stopped (step S5-6). Then, the main water supply valve 71 and the dehumidifying water supply valve 73 are opened (step 5-7), and the drum 12 is rotated at the low speed RL (step S5-8). This rotational speed RL is the lowest rotational speed at which tap water supplied from the main water supply valve 71 to the space sandwiched between the outer tub 10 and the drum 12 is dragged by the rotation of the drum 12 and turns in the space. . For example, the rotation speed is 100 to 150 rpm. This defoaming process is performed for a predetermined time T2 (step S5-9). And the main water supply valve 71 and the dehumidification water supply valve 73 are closed (step 5-10), the number of times of the foam elimination processing performed so far is set (step S5-11), and the number of times is less than the predetermined value N2. The process returns to the normal intermediate dehydration step before the defoaming process (step S5-2). When it reaches a predetermined number of times, for example, 3 times, an intermediate dehydration skip flag is set (step S5-12), and the drum rotation is stopped (step S5-17). And the frequency | count of a foam elimination process is reset (step S5-18), a drain valve is closed (step S5-19), and it progresses to the following 1 rinse process.

If it is not abnormal foaming, the rotational speed is increased and it is determined whether the drum rotational speed has reached the final rotational speed RE (step S5-14). If it has reached, the drum rotational speed is fixed at the final rotational speed RE. (Step S5-15), centrifugal dehydration is performed for a predetermined time THTD (Step S5-).
16). Then, the drum rotation is stopped (step S5-17), the drain valve 26 is closed (step S5-19), the number of bubble erasing processing is reset (step S5-18), and the process proceeds to the next rinsing step.

  In the dehydration process, vibration of the outer tub due to the displacement of the cloth becomes a problem. Therefore, it is common to detect the vibration of the outer tub 12 during the start of dewatering and perform a process of correcting the displacement of the cloth. However, in the above description of this embodiment, this processing is omitted for the sake of simplicity.

  As described above, the detection of foaming by the electrodes B1 and B2 has been described in the dehydration process. However, even in the washing process, the space between the outer tub and the drum 12 is filled with bubbles, and reaches the top where the electrodes B1 and B2 are installed. Sometimes it reaches. In anticipation of such a case, it is desirable to include the signal monitoring of the foam detection circuit A in the flowchart of the washing process of FIG. In this case, the above-described method may be used for the foam erasing process.

FIG. 14 shows a flowchart of the water supply after the intermediate dehydration 1 and the subsequent rinsing process. First, the main water supply valve 71 is opened (step S6-1), water is supplied to a predetermined water level THSS (step S6-2), and the main water supply valve 71 is closed (step S6-3). This water level is higher than the water level THSA in the washing step, that is, the amount of water is increased.

  If the intermediate dewatering skip flag is set, a process for changing the water level may be performed in order to further increase the amount of rinse water.

  When the water supply is completed, the drum is rotated forward and backward at a predetermined rotation speed (for example, 50 rpm) with a stop for a predetermined time (for example, 20 seconds) to rinse away the detergent contained in the laundry in tap water 1 A process is performed (step S7-1).

Even when the laundry is rinsed in the drum 12, the detergent melts from the laundry, and the washing water containing the detergent generates foam by receiving the impact of the laundry that falls sequentially, and further below the foam. When the foam is pushed up by rolling the laundry, the foam reaches the inside of the outer tub 10 from the small hole 13 or the opening 15, and further communicates from the inside of the outer tub 10 to the lower water outlet / air inlet 58. In some cases, the water-cooled dehumidification duct 55 reaches the electrodes C1 and C2.

  At this time, the microcomputer 90 reads the output frequency of the foam detection circuit B connected to the electrodes C1 and C2 (step S7-2). If this output frequency becomes higher than the predetermined frequency THS (step S7-3), it means that the bubbles have reached the position of the electrodes C1, C2 installed in the water-cooled dehumidifying duct 55, and the inside of the drum 12 In step S7-4, it is determined that abnormal foaming has occurred in a large amount of bubbles. If it is less than THS, the washing process for rotating the drum forward and backward is continued until a predetermined time THTS (S7-5), the number of defoaming processes is cleared (step S7-18), and the process proceeds to the next intermediate dehydration 2. .

When abnormal foaming is detected, a foam erasing process is performed. First, the rotation of the drum 12 is stopped (step S7-6), the drain valve is opened (step S7-7), and the washing liquid is drained. While monitoring the signal of the water level sensor 30 (step S7-8), when all the washing liquid is drained (when the water level reaches THR), the main water supply valve 71 is opened with the drain valve open, and tap water is placed in the drum. And the dehumidifying water supply valve 73 are also opened (step S7-9), and the bubbles in the duct 55 are also poured out. At this time, the drum 12 is rotated forward and backward at a low speed (step S7-10) so that the tap water is evenly applied to the laundry with the foam in the drum. This water supply is performed for a predetermined time T3 (step S7-11), thereby limiting the amount of water supply. For example, 6 liters. Thereafter, the drain valve 26 is closed (step S7-12), and when water is supplied to the water level THSS1 lower than the water level THSS in the rinsing process while monitoring the water level sensor 30 (step S7-13), the main water supply valve 71 and the dehumidifying water supply valve 73 are supplied. Is closed (step S7-14). Then, the number of the above-described foam erasing process is set (step S7-15). If the number is less than the predetermined value N3, the process returns to the state before the foam erasing process, that is, the normal washing process (step S7-16). . When the predetermined number of times, for example, 3 times is reached, the intermediate dewatering skip flag is set (step S7-17), the number of bubble erasing processing is cleared (step S7-18), and the process proceeds to the next intermediate dewatering 2 step.

  The subsequent intermediate dehydration 2 and rinsing 2 steps are the same as the previously described intermediate dehydration 1 and rinsing 2 steps, and thus detailed description thereof is omitted. Further, since the final dehydration process subsequent to the rinsing process 2 is the same as the intermediate dehydration 1, detailed description thereof is omitted.

  Although the present invention has been described with respect to the operation of the drum type washing machine, the present invention is not limited to this, and it is apparent that the present invention can be similarly applied to a conventional vertical washing machine.

  FIG. 15 shows a second embodiment of the control unit of the present invention. In FIG. 15, the same reference numerals as those in FIG. Reference numeral 100 denotes an electrode selection circuit. In this embodiment, the foam detection circuit B92 is omitted, and each pair of electrodes B1, B2 and electrodes C1, C2 is selected and connected to one foam detection circuit A91. Since the configuration and operation of the present embodiment are substantially the same as those of the first embodiment, description thereof is omitted. An operation for the microcomputer 90 to switch the electrode selection circuit 99 and select a necessary electrode may be added to the operation flowchart in the first embodiment in the reading of the foam signal by each pair of electrodes.

  According to this embodiment, since the foam detection circuit B92 can be omitted, the cost of the washing machine can be reduced.

  FIG. 16 shows a second embodiment of the configuration of the present invention. In FIG. 16, the same reference numerals as those in FIG. As shown in the drawing, this configuration is omitted by substituting the electrodes B2 and C2 with A2.

  FIG. 17 shows a third embodiment of the control unit of the present invention corresponding to the second embodiment of the configuration of the present invention. In FIG. 17, the same reference numerals as those in FIG. Reference numeral 101 denotes a foam detection circuit C. FIG. 18 shows details of the foam detection circuit C101. In this circuit, one end of the primary coil L1 of the transformer T is connected to the electrode A2. The other end is connected to the electrodes B1 and C1 via the switching circuit 103. The primary coil L1 is provided with a tap and connected to the electrode A1 via the switch 102. If the number of turns of the primary coil L1 is 1250 turns, the tap has the characteristics shown in FIG. 8 if the position is 125 turns from the side connected to the electrode A2. The foam detection circuit C101 uses the electrode A2 as a common electrode, and closes the switch 102 and connects to the electrode A1 when detecting the detergent concentration. The characteristics at this time are shown in FIG. The resistance value between the electrodes A1 and A2 is detected to detect the detergent concentration. On the other hand, when detecting the presence of bubbles, the switch 102 is opened to open the electrode A1, and the resistance value between the electrode A2 and the electrode selected by the switching circuit 103 is detected. The characteristics at this time are shown in FIG. For example, when detecting the entry of bubbles into the duct 55, the entry of bubbles is detected by a change in resistance value between the electrode C1 selected by the switching circuit 103 and the common electrode A2.

  Since the electrode A2 is installed in the water reservoir at the lowermost part of the outer tub, the electrode A2 is immersed in the washing liquid in the washing process, and is also immersed in the rinsing liquid in the rinsing process. Even in the dehydration process in which the washing liquid is drained, the foam is always surrounded by bubbles when the foam reaches the position of the electrodes B1 and C1. Therefore, it can be used as a common electrode.

  Since the operation of this embodiment is substantially the same as that of the first embodiment, the description thereof is omitted. In the operation flowchart in the first embodiment described above, in reading the foam signal by each pair of electrodes, the microcomputer 90 controls the switch 102 and the switching circuit 103 in the foam detection circuit C101 to form an electrode paired with the common electrode A2. It is only necessary to add an operation of selecting the necessary electrodes by switching.

  As described above, according to the present embodiment, it is possible to reduce the cost of the washing machine because it is possible to detect the foaming and the detergent liquid concentration with only one foaming detection circuit C101 and to halve the detection electrode.

The front view of the washing machine of Embodiment 1 of this invention. The sectional side view of the washing machine. The back view of the washing machine. The top view of the washing machine. FIG. 3 is a circuit diagram of a control unit in which the washing machine is partially blocked. The circuit diagram of the foam detection circuit A. A circuit diagram of a CR oscillation circuit. The characteristic diagram of a foam detection circuit. 2 is a schematic operation flowchart of the washing machine according to the first embodiment of the present invention. The operation | movement flowchart of a detergent liquid dilution process. Relationship between detergent liquid concentration and detergent liquid concentration detection circuit output. The operation | movement flowchart of a washing process. The operation | movement flowchart of the intermediate | middle dehydration process 1. FIG. The operation | movement flowchart of the rinse process 1. FIG. The control part circuit diagram made into a partial block of the washing machine of Embodiment 2 of the present invention. The reverse view of the washing machine of Embodiment 3 of this invention. FIG. 3 is a circuit diagram of a control unit in which the washing machine is partially blocked. The circuit diagram of the foam detection circuit C. FIG.

Explanation of symbols

1 Washing machine outer frame 10 Outer tub (water receiving tub)
DESCRIPTION OF SYMBOLS 11 Elastic support device 12 Drum 20 Brushless motor 38 Blower fan motor 47 PTC heater 55 Water cooling dehumidification duct 57 Dehumidification water injection port 71 Main water supply valve 72 Softener water supply valve 73 Dehumidification water water supply valve 91 Foam detection circuit A
92 Foam detection circuit B
94 Detergent concentration detection circuit 101 Foam detection circuit C
A1, A2, B1, B2, C1, C2 A pair of electrodes

Claims (6)

  A transformer, a pair of electrodes connected to the primary coil of the transformer, a conversion resistor appearing in the secondary coil of the transformer, in which the resistance between the pair of electrodes is converted, and an oscillation circuit whose oscillation frequency is determined by a capacitor And a pair of electrodes arranged in an outer tank (water receiving tank) or a part communicating with the outer tank, and configured to detect the presence of water or bubbles containing a detergent solution between the electrodes. Features a washing machine.   A water supply means for supplying water into the outer tub; a drain means for draining water in the outer tub; and a control means for controlling a series of washing operations and the water supply means and the drain means. The washing machine according to claim 1, wherein a resistance value between the electrodes is detected to control a washing operation and the water supply means and drainage means.   The winding turns ratio of the primary coil and the secondary coil of the transformer is N to 1 and N is 5 or more when detecting the presence of bubbles, and 1 to when detecting the presence of water containing a detergent solution. The washing machine according to claim 1, wherein N and N are 2 or less.   A drum having a central axis of rotation in a horizontal direction or an inclined direction, an outer tub containing the drum and elastically supported by a washing machine body, water supply means for supplying water into the outer tub, and water in the outer tub Draining means for draining, a pair of electrodes provided at the lowest part of the outer tub, and a detergent concentration detecting means for detecting the detergent concentration of the washing water by detecting a resistance value between the pair of electrodes, and supplying detergent The detergent concentration is detected by the detergent concentration detecting means at the time of subsequent water supply and detergent dissolution and stirring. If the concentration is equal to or higher than the predetermined concentration, the stirring is stopped, a part of the water is drained, and the water is diluted again by supplying water again. The washing machine is characterized by starting washing and stirring after becoming.   A drum having a central axis of rotation in a horizontal direction or an inclined direction, an outer tub containing the drum and elastically supported by a washing machine body, water supply means for supplying water into the outer tub, and water in the outer tub Drainage means for draining, drive means for rotationally driving the drum, a pair of electrodes provided so as to face the drum near the upper surface center of the outer periphery of the outer tub, and a change in resistance value between the pair of electrodes is detected. Foam detection means for detecting the presence of foam between the outer tub and the drum, and a control means for controlling a series of washing operations and the water supply means, drainage means, and drive means, and detecting the foam when the drum rotates. When the means detects foaming between the outer tub and the drum, the control means stops the driving means and supplies water into the outer tub.   A drum having a central axis of rotation in a horizontal direction or an inclined direction, an outer tub containing the drum and elastically supported by a washing machine body, water supply means for supplying water into the outer tub, and water in the outer tub A draining means for draining, a driving means for rotating the drum, a warm air generating means for drying the laundry, a hot air blowing path for guiding the warm air into the front surface of the outer tub, and the inside of the outer tub A dehumidification path for dehumidifying the discharged hot air and sending it to the hot air generating means, a water injection means for injecting water into the dehumidification path, a pair of electrodes provided in the dehumidification path, and a resistance value between the pair of electrodes Foam detection means for detecting foam intrusion into the deep part of the dehumidification path from a change, control means for controlling a series of washing and drying operations, the water supply means, drainage means, drive means, hot air generating means, and water injection means And the control means includes the foam detection hand. In upon detection of bubbles from entering the dehumidifying passage, washing machine drained wash water of the outer tub in the drainage unit, characterized in that water injection into dehumidifying the path by the water injection means.

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