JP2006334204A - Electric washing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric washing machine with excellent handleability which is not used when a liquid detergent is out. <P>SOLUTION: The electric washing machine is provided with a container 40 for housing the liquid detergent 41, a washing tub 31, a detergent feeding means 43 for feeding the liquid detergent 41 from the container 40 to the washing tub 31, and a liquid level detection means 46 having a thermistor 44, and the liquid level of the liquid detergent 41 inside the container 40 is detected by the change of the electric characteristics of the thermistor 44. In the case that the residual amount of the liquid detergent 41 inside the container 40 becomes little, since the thermistor 44 is exposed into the air from the liquid surface of the liquid detergent 41, the electric characteristics of the thermistor 44 are changed. Thus, the liquid level of the liquid detergent 41 is surely detected, use in the state without the liquid detergent 41 is prevented, and the electric washing machine which constantly secures a high washing performance is realized. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric washing machine used for general household use or business use.

  As a conventional electric washing machine of this type, there is one configured so that a liquid detergent is automatically charged into a washing and dewatering tank by an automatic detergent charging device (see, for example, Patent Document 1).

  The conventional electric washing machine described in Patent Document 1 will be described with reference to FIG.

As shown in FIG. 8, an upper frame 20 is provided on an upper part of a washing machine body 1 of a conventional electric washing machine, and a lid 22 is provided to cover a clothing input opening provided in the upper frame 20. The upper frame body 20 is configured to be equipped with an automatic detergent introduction device 23 for introducing the liquid detergent 15 into the washing and dewatering tub 2, and the replenishment port 17 of the detergent tank 16 constituting the automatic detergent introduction device 23 and the same. The cap 18 that covers the upper frame 20 protrudes upward from the opening 20a provided in the upper frame 20, and the lid cover 24 is attached.
JP 2004-313234 A

  However, in the configuration of the conventional electric washing machine, there is no means for displaying to the user how much liquid detergent 15 is remaining, and the liquid detergent is automatically put in and washing is performed. In terms of the point, the laundry work is easier, but the user's impression of the remaining amount of detergent tends to be less because the detergent is always automatically added. In some cases, the user may continue to use the detergent without noticing that the detergent is bottomed, and there is a problem that a sufficient washing effect cannot be obtained.

  The present invention solves the above-mentioned conventional problems, and automatically introduces liquid detergent and detects when the remaining amount is reduced, and informs the user, etc. An object of the present invention is to provide an electric washing machine that can prevent a decrease in washing performance due to use.

  In order to solve the conventional problems, an electric washing machine of the present invention includes a container for storing a liquid detergent, a washing tub, a detergent charging unit for charging the liquid detergent from the container into the washing tub, and a thermistor. A liquid level detecting means for detecting the liquid level of the liquid detergent in the container by a change in the electrical characteristics of the thermistor, and the remaining amount of liquid detergent in the container is reduced In addition, since the thermistor is exposed from the liquid surface of the liquid detergent to the air, the thermistor changes its electrical characteristics, which makes it possible to reliably detect the liquid detergent liquid level. For example, if it is displayed, it is possible to provide an electric washing machine that prevents use in a state where the liquid detergent has run out and always ensures high washing performance.

  The electric washing machine of the present invention can detect the remaining amount of the liquid detergent with high reliability, thereby preventing use in a state where the liquid detergent has run out, and always ensuring high washing performance.

  A first invention includes a container for storing a liquid detergent, a washing tub, a detergent charging means for charging the liquid detergent from the container into the washing tub, and a liquid level detection means having a thermistor, The liquid level of the liquid detergent is detected by a change in the electrical characteristics of the thermistor, and when the remaining amount of liquid detergent in the container is low, the thermistor moves from the liquid detergent surface to the air. As a result, it is possible to detect the liquid level of the liquid detergent with certainty. If the detection result is displayed, for example, the liquid thermistor will run out. It is possible to provide an electric washing machine that prevents use in a state and ensures high washing performance at all times.

  In the second invention, in particular, the thermistor of the first invention is covered with an insulator having excellent water repellency, and the level of the liquid detergent in the container is lowered, and the thermistor is exposed to the air. Providing a highly reliable electric washing machine by preventing detergent from being falsely detected even though there is no detergent, because the detergent can be taken immediately to a state unrelated to the thermistor. it can.

  In the third invention, in particular, the container according to the first or second invention also serves as a windproof layer for preventing wind from hitting the thermistor. For example, the thermistor is disposed in the container, and the container is disposed. By serving also as a windbreak layer, when there is a strong wind inside or outside the electric washing machine, even if the level of the liquid detergent decreases and the thermistor is exposed to the air, the thermistor is cooled by those winds. Therefore, it is possible to effectively prevent a malfunction that there is a detergent even though there is no detergent, and it is possible to provide a highly reliable electric washing machine.

  According to a fourth aspect of the invention, in particular, the liquid level detecting means according to any one of the first to third aspects of the invention is adapted to detect a liquid detergent liquid level in response to a transient phenomenon of a thermistor's electrical characteristic change when the electric washing machine is started. By detecting the amount of liquid detergent remaining when the electric washing machine is activated in a short time after the electric washing machine is activated, the detergent can be used before the user leaves the electric washing machine. When the amount is decreasing, it is possible to inform the user, and it is possible to provide a more convenient electric washing machine.

  The fifth invention is provided with a display means for displaying the detection result of the liquid level of the liquid detergent by the liquid level detection means of any one of the first to fourth inventions, particularly when the liquid detergent is reduced. In addition, since the user can easily know the information by the display means, it is possible to prevent the electric washing machine from being operated without knowing that the liquid detergent is little or not present.

  In a sixth aspect of the invention, in the electric washing machine of the fifth aspect of the invention, when the clothes are taken out after washing or after washing, the liquid level detection result by the liquid level detection means is displayed on the display means. A sufficiently reliable liquid level detection result can be displayed when a sufficient time has elapsed since the start of the electric washing machine and the electrical characteristics of the thermistor are stable. be able to.

  In the seventh aspect of the invention, in particular, in the electric washing machine of the fifth aspect, at the start of use, the liquid level detection result by the previous liquid level detection means is displayed on the display means. A highly reliable detection result obtained with sufficiently stable electrical characteristics is stored in, for example, a storage means, read out from the storage means at the next start-up, and displayed on the display means, immediately after startup. In addition, it is possible to check the remaining amount of the liquid detergent and to provide an excellent electric washing machine that is very convenient to use.

  In the eighth invention, in particular, the container according to any one of the first to seventh inventions is provided with a discharge port for discharging a liquid detergent, and a thermistor is provided in the vicinity of the discharge port. The ratio of the remaining amount of the liquid detergent when the liquid level detecting means determines that the liquid level is insufficient can be reduced, and an electric washing machine that can use the liquid detergent very efficiently without waste can be provided.

  In the ninth invention, in particular, a recess is disposed on the bottom surface of the container of any one of the second to eighth inventions, and a part of the insulator covering the thermistor is provided so as to reach the recess. Electric washing machine that can reduce the ratio of the remaining amount of liquid detergent when the liquid level detection means determines that the liquid level is insufficient relative to the volume of the container. Can be provided.

  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)
The electric washing machine in the 1st Embodiment of this invention is demonstrated using FIGS. FIG. 1 shows a cross-sectional view of an electric washing machine according to the present embodiment.

  1, the electric washing machine according to the present embodiment includes a housing 30, a washing tub 31 provided in the housing 30, a rotating drum 32 provided rotatably inside the washing tub 31, and a rotating drum. 32, a motor 33 using a permanent magnet (not shown), a mechanical case 34 for attaching the motor 33 to the washing tub 31, and an opening of the washing tub 31 provided on the front surface of the housing 30 so as to be opened and closed. A lid 35 for closing the part 31a, a water supply pipe 36 for watering the washing tub 31, a water supply valve 37 provided in the middle of the water supply pipe 36, and a drain pipe 38 for discharging water from the washing tub 31. A drain valve 39 provided in the middle of the drain pipe 38 is provided.

  Further, a container 40 for storing the liquid detergent 41 is provided above the washing tub 31, and a detachable cap 42 is attached to the upper part of the container 40 so that the user opens when the liquid detergent 41 is replenished. It has become a thing.

  And the detergent insertion means 43 which introduce | transduces the liquid detergent 41 from the container 40 to the washing tub 31 is comprised by the valve (not shown) opened and closed by an electrical signal.

  46 comprises a thermistor 44 provided in the container 40 and an electronic circuit 45, and the liquid level of the liquid detergent 41 in the container 40 reaches a predetermined amount, in this embodiment, reaching a height of 15 mm from the bottom of the container 40. It is a liquid level detection means for detecting whether or not it is present. Electric power is supplied to the thermistor 44 so that self-heating of about 100 mW is generated. When the thermistor 44 is immersed in the liquid detergent 41 and the cooling effect is large, the amount of the liquid detergent 41 is reduced and the thermistor 44 is reduced. The temperature of the thermistor 44 in a thermally stable state changes when the air 44 touches the air above the liquid surface of the liquid detergent 41 and the cooling effect is small, and the resistance value of the thermistor 44 changes accordingly. . The liquid level detection means 46 detects the change in the resistance value from the difference in the terminal voltage of the thermistor 44, that is, the electrical characteristics.

  However, the thermistor 44 when the electric washing machine is turned on is in a state that is substantially close to room temperature, reaches a thermally stable state from that point, and the liquid level detection means 46 can output a correct detection result. In order for this to take place, it takes about 30 seconds at the maximum, and in this embodiment, the detection output from the liquid level detection means 46 is output 30 seconds after activation.

  Reference numeral 47 denotes a storage means configured using an EEPROM capable of continuously storing a digital signal even when the electric washing machine is turned off. The detection result of the liquid level detection means 46 is stored, and the next electric washing machine When the machine is turned on and used, the previous detection result stored in the storage means 47 is transmitted to the display means 48 and displayed.

  In the present embodiment, the container 40 is made of polypropylene and has a small air hole (not shown) having a diameter of about 2 mm for drawing outside air into a space generated above the liquid level when the liquid level of the liquid detergent 41 is lowered. In other words, the wind generated outside the electric washing machine and inside the housing 30 can be prevented from hitting the thermistor 44 by the container 40, that is, the container 40 is also a windproof layer. It is also configured to serve as.

  As a result, even if the liquid level in the container 40 is lowered and the thermistor 44 is exposed to the air above the liquid level, the external wind does not act on the thermistor 44.

  A control circuit 50 using a microcomputer or the like supplies electric signals and electric power in order to the motor 33, the water supply valve 37, and the drain valve 39 as necessary, and thereby supplies tap water from the water supply pipe 36. Supplying to the washing tub 31, rotating the rotating drum 32 by the motor 33, and draining the washing tub 31 through the drain pipe 38 to wash the laundry such as the clothes 51 in the rotating drum 31. It has become.

  The detergent loading means 43 is also driven by the control circuit 50 so that an appropriate amount of liquid detergent 43 is automatically thrown into the washing tub 31 at the beginning of washing. Accordingly, it is possible to use the liquid detergent 41 without waste. However, the liquid detergent 41 is not particularly limited to such a configuration. For example, a liquid with a gear (gear) type pump can be used. The detergent 43 may be sucked out or pushed out, or may be ejected from the container 40 by pushing down the liquid detergent 43 with air pressure. Even if it is not automatic, for example, a lever operation is performed. As a result, the liquid detergent 41 may be discharged mechanically.

  FIG. 2 shows an enlarged cross-sectional view of the peripheral portion of the thermistor 44 in the present embodiment.

  In FIG. 2, a thermistor 44 is composed of a Teflon (registered trademark) tube 55 having an outer diameter of 3 mm and excellent in heat resistance and a filler 56 made of a heat resistant resin injected from both upper and lower openings of the tube 55. The terminals 58 and 59 of the thermistor 44 are led out from the lead wire 60 with insulation coating, but the terminals 58 and 59 rise in liquid level and are liquid detergent. Even when it is in a state of being submerged in 41, the electrical insulation with the liquid detergent 41 can be maintained.

  In the present embodiment, the outer surface of the insulator 57, that is, the portion in contact with the liquid detergent 41, when the liquid level is lowered, the liquid detergent 41 is quickly released so that unnecessary adhesion is reduced. What used special surface treatment is used, and it has sufficient water repellency.

  As described above, since the electrical insulation between the liquid detergent 41 and the thermistor 44 is ensured by the insulator 57, the electronic circuit 45 connected from the terminals 58 and 59 is, for example, generally used at 100V, 50 or 50 Even with a compact and low-cost configuration provided without electrical insulation with a commercial power source such as 60 Hz, sufficient safety can be ensured.

  The structure of the insulator 57 may be other than that shown in the present embodiment. For example, another insulator tube having another water repellency is covered outside the tube 55 having no water repellency. It does not matter even if it is.

  FIG. 3 shows a circuit diagram of the electronic circuit 45 to which the thermistor 44 of this embodiment is connected.

  The thermistor 44 is connected to a 250 ohm resistor 66 by a connector 65.

  The upper terminal of the resistor 66 is connected to a 12V DC power supply 67, and a current is supplied from the resistor 66 to the thermistor 44 to cause the thermistor 44 to self-heat.

  The voltage of the DC power supply 67 is divided by the resistor 66 and the thermistor 44 to generate the voltage V1, which is added to the voltage dividing circuit 70 by the resistors 68 and 69 in this embodiment. Since the resistance value of the series circuit of the resistors 68 and 69 is sufficiently larger than that of the resistor 66, the decrease in V1 due to the connection of the voltage dividing circuit 70 is almost ignored. Design is possible.

  The output of the voltage dividing circuit 70 is a voltage signal from which noise components have been further removed by the resistor 71 and the capacitor 72, and an analog voltage V1 is obtained, which is input to the microcomputer 75. The microcomputer 75 operates upon receiving power supply from a 5V DC power supply 76, and has an AD converter 77 and a CPU 78 for converting an analog voltage into an 8-bit digital value. The diode 79 is protected by being controlled within the output voltage range of the 5V DC power supply 76 so that the analog voltage V1a input to the microcomputer 75 does not become excessive.

  With the above configuration, the liquid level detection means 46 of the present embodiment divides the terminal voltage V1 of the thermistor 44 by the voltage dividing circuit 70 and takes the analog voltage V1a into the microcomputer 75, and the AD converter 77 converts the digital value D1. 30 seconds after the CPU 78 is activated, that is, the built-in program starts at the timing when the thermistor 44 is thermally stabilized, the reading sequence is executed, and the digital value is a predetermined value. If it is 128/256 or more, it is detected that the liquid level is high, that is, the liquid detergent 41 still remains in the container 40 in a predetermined amount or more. If it is 127/256 or less, the liquid detergent The remaining amount of 41 is equal to or less than a predetermined value, and it is detected that the thermistor 44 comes out of the liquid detergent 41 into the air.

  In the present embodiment, by supplying self-heating power to the thermistor 44, the element temperature of the thermistor 44 is different between the liquid detergent 41 and the air under ambient cooling conditions while heating the thermistor 44. Since it is used to determine whether the liquid level is higher or lower than the position where the thermistor 44 is detected by detecting the difference in the electrical characteristics of the thermistor 44, for example, using a float, etc. Compared to the above, there are no mechanically movable parts, so there is no concern that the mechanically movable parts will wear due to vibration, especially for washing / dehydration vibrations that occur in electric washing machines. Since the movable part does not become a noise source due to vibration, it is excellent in terms of high reliability and noise reduction.

  In addition, since the liquid level of the liquid detergent 41 having a relatively high viscosity is detected, the water-repellent insulator 57 made of Teflon (registered trademark) as shown in the present embodiment has a considerable repellent property. It is water-based, and is advantageous in that the liquid detergent 41 adhering to the height near the thermistor 44 can be quickly moved downward when the liquid level of the liquid detergent 41 is lowered. Since there is an advantage that a surface treatment can be added depending on the surface, for example, even if the electrode pair is used to detect whether or not the electrode pair is in contact with the liquid from the change in the electric resistance between them, the surface treatment It can be realized relatively easily to bring the state of the above to the property of repelling the liquid detergent 41, and the detection when the liquid level is lowered becomes more reliable.

  At this point, in the present embodiment, the detected result is stored in the storage means 47 using the EEPROM, and the storage means 47 stores the data even when the electric washing machine is turned off. Since it becomes non-volatile and is read again by the microcomputer 75 at the next operation, that is, the display means 48 displays the detection result of the liquid level detection means 46 at the previous use at the next use. It has become.

  Even if the thermistor 44 is exposed from the surface of the liquid detergent 41, the thermistor 44 is still in the state where the liquid detergent 41 still remains in the lower part of the container 40 more than the amount that can be washed at least once. If the mounting height L1 is set, no trouble with washing due to the lack of the liquid detergent 41 occurs at all for the current washing.

  In the present embodiment, the read previous data is transmitted from the Q output to the display means 48, and the display means 48 displays according to the remaining amount of the liquid detergent 41 accordingly. .

  As the display means 48, a light emitting diode (LED) that is turned on / flashes, a liquid crystal display, a sound, and the like can be considered.

(Embodiment 2)
FIG. 4 is a cross-sectional view of the electric washing machine according to the second embodiment of the present invention, and FIG. 5 is a graph showing temporal changes in the terminal voltage V1 of the thermistor of the electric washing machine. In addition, about the same part as the electric washing machine in the said 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In this embodiment, as shown in FIG. 4, there is no storage means for storing the liquid level detection result at the previous use, and the electronic circuit of the liquid level detection means 86 for detecting the liquid level of the liquid detergent 41 in the container 40. The configuration 85 is slightly modified from the first embodiment, and the other configurations are the same as those in the first embodiment.

  In the present embodiment, the liquid level detection means 86 receives the change of the terminal voltage V1 due to the value of the electric resistance of the thermistor 44, that is, a transient phenomenon of the change in the electric characteristics when the electric washing machine is started up. When the liquid level of the liquid detergent does not reach a predetermined amount, this is detected, and when the user finishes washing and takes out the cloth such as the clothing 51, the liquid level detection means 86 displays the detection result of the liquid level of the liquid detergent 41. To be displayed.

  Thus, in the present embodiment, the liquid level is detected when the thermistor 44 is in a transient state, and the detection result is displayed by the display means 48 when the user takes out the garment 51 after washing. However, it is not particularly limited to this combination of configurations, and may be a combination with the configuration described in the first embodiment.

  FIG. 5 is a graph showing temporal changes in the terminal voltage V1 of the thermistor 44 when the electric washing machine is turned on.

  In general, the electric washing machine is not connected to a 100 V, 50 or 60 Hz AC power supply (commercial power supply) before use, and a power cord (not shown) is connected to an outlet (not shown). Even when connected, since various circuit configurations are taken to eliminate standby power, it is substantially the same as the state in which the power cord is disconnected. 5 is not supplied, and the element temperature of the thermistor 44 is substantially room temperature. Therefore, the value of the analog voltage value V1 at time 0 seconds is a voltage value substantially corresponding to room temperature. In the example, the room temperature is 11 V corresponding to 20 degrees Celsius.

  The V1 voltage value (= V1 (0)) at this moment is the temperature of the liquid detergent 41 or the air, regardless of whether the thermistor 44 is immersed in the liquid detergent 41 or has a face in the air. Since only the corresponding voltage is output, it cannot be determined from the value alone whether the liquid level is above or below the height L1 of the thermistor 44.

  When the time t elapses after the start, that is, when the thermistor 44 starts self-heating, the V1 voltage (= V1 (t)) is a when the liquid detergent 41 is submerged, and the face is exposed in the air. It becomes b and gradually becomes a difference, and it takes about one minute in any state to reach a voltage value that is almost completely stable.

  The stable voltage value is 8V when the thermistor 44 is in the liquid detergent 41, and 4V when the face is exposed in the air. For example, when the thermistor 44 is lower than 6V with 6V as a threshold value. If it is determined in the air, that is, that the liquid detergent 41 has decreased below the predetermined remaining amount, detection is performed 20 seconds after activation, and a certain amount of detection time is required.

  In the present embodiment, when the V1 voltage at the time of activation is detected as 11 V, a threshold waveform that changes according to the V1 voltage value at the time of activation and the time is shown as indicated by a c curve (broken line) in FIG. The microcomputer 75 has a program for generating a threshold value by a calculation formula using a logarithmic function shown below.

VTH (t) = VTH (∞) + (V1 (0) −VTH (∞)) · EXP (−t / TAU))
By calculating the above, it is assumed that the threshold value VTH (t) gradually changes with the time t according to the time t after startup, and VTH (∞) = 6V is set as the stable threshold value. In the TAU, a time constant of about several seconds is set so that the threshold change curve can be set optimally.

  However, the threshold value VTH (∞) at the time of stabilization may not be set to a fixed value such as 6 V, but may be set, for example, as a function of the V1 voltage at start-up or changed according to the operating state of other loads. .

  In addition, since the actual change curve of V1 is slightly different from the curve calculated by the above equation, it is also effective to use a table in the microcomputer 75 that is easily referred to and the threshold value is calculated by referring to it. It is.

  Theoretically, the curves a and b are slightly different from immediately after start-up, so if the threshold curve c can always be set between them, within a very short period after start-up. Although it is possible to detect whether or not the liquid level has reached the thermistor 44, in reality, since a variable element such as a noise component with respect to the threshold acts, certain detection may take some time. Become.

  Incidentally, at the time point 20 seconds later, a is 8.3 V, and b is 6 V, which is 2.3 V, which is too much even considering the above-mentioned noise components.

  In the present embodiment, detection is performed at a time point 10 seconds after activation, but at this time point, the voltage difference between a and b is about 1 V, and the curve c passes through almost the middle point. The inventors have confirmed that it can be designed, and the influence of noise components in detection does not become a problem.

  Incidentally, the value of the curve b (the state where the thermistor 44 is in the air) at the time when the detection is completed 10 seconds after the activation is 8.1 V, which is the value of the curve a (the state where the thermistor 44 is in the liquid). It is clear that the detection time can be shortened by taking into account various variations with respect to the curve a by increasing the threshold value of 6V, which is higher than the stable value of 8V, to 6V, which is the threshold value of the first embodiment. It is.

  As described above, in the present embodiment, the detection time from the start is almost half as compared with the detection by comparison with the voltage of the thermistor 44 at the time of stability, that is, the constant value threshold value calculated from the electrical characteristics. It will be time.

  In addition, the inventors have a 50% chance that a user of an electric washing machine is still in the vicinity of the electric washing machine if it is about 10 seconds after putting the laundry such as the clothes 51 and starting the operation. As a result of the investigation, it is known that there is a degree, and if the liquid detergent 41 is reduced below a predetermined amount even at that time, it is effective to notify the fact with a warning sound or the like.

  In the present embodiment, the threshold voltage that changes depending on the terminal voltage of the thermistor 44 at the time of start-up and the elapsed time from that time is set, so that the liquid is changed at the stage of the transient phenomenon of the electrical characteristic change of the thermistor 44. Although it is configured to detect that the level of the detergent 41 is not a predetermined amount, it is not particularly limited to such a detection method. For example, the time is shifted from the start to several points, specifically 0. Measure the voltage V1 of the thermistor 44 at the time after 2 seconds (startup), 5 seconds, 10 seconds, etc., and estimate the time constant, stable value, etc. from the change in V1, and these estimated values are liquid Detection may be performed by utilizing the difference between the detergent 41 and the air, and various variations of the program of the microcomputer 75 are conceivable.

  Regardless of the detection algorithm, the liquid detergent 41 includes a case where the element temperature of the thermistor 44 at the time when it is detected that the liquid level of the liquid detergent 41 is lower than that of the thermistor 41 varies slightly. When the temperature of the thermistor 44 is lower than the temperature of the thermistor 44 in a stable state, the liquid detergent 41 is detected to have a predetermined level due to a transient phenomenon of change in the electrical characteristics of the thermistor 44. It will be done.

(Embodiment 3)
FIG. 6 is a sectional view of the container of the liquid level detecting means of the electric washing machine according to the third embodiment of the present invention. In addition, about the same part as the electric washing machine in the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the present embodiment, as shown in FIG. 6, the container 90 for storing the liquid detergent 41 is formed in a substantially stomach-like shape and a recess 91 is formed at the bottom, and the tip of the insulator 57 covering the thermistor 44 reaches the recess 91. In this way, the discharge port 92 provided at the bottom of the recess 91 is communicated with the detergent charging means 43.

  For the water-repellent insulator 57 covering the thermistor 44, for example, penetration of the liquid detergent 41 from the end face of the rod-like water-repellent insulator 57 through a minute gap between the insulators or the like. In order to prevent deterioration of the electrical insulation due to the liquid crystal and to ensure sufficient insulation, it is necessary to provide an extra eye from the thermistor 44 to some extent, and when the thermistor 44 is exposed from the liquid surface, the viscosity The lower side of the water-repellent insulator 57 is intended to be slightly longer from the viewpoint of the advantage that the characteristics of pulling the drop of the liquid detergent 41 having a high viscosity from the thermistor 44 as soon as possible are advantageous. It works very effectively.

  According to this configuration, even when the thickness of the container 90 is increased so that a large amount of the liquid detergent 41 can be stored, the height of the thermistor 44, that is, the state in which the liquid detergent 41 is remaining low is detected. Since the remaining amount of the liquid detergent 41 can be reduced, it is possible to eliminate the problem that a large amount of the liquid detergent 41 remains as a remaining amount after it is detected that the remaining amount is small. It will be a thing.

  In particular, when the first liquid detergent 41 is put in a bottle or the like, it is detected that the remaining amount is low even though the amount of liquid detergent 41 actually used is small with respect to the injection amount. However, such a thing can be prevented as much as possible.

  Incidentally, in the present embodiment, 600 ml of the liquid detergent 41 can be stored in a state where the container 90 is full, whereas the detection is performed when the thermistor 44 protrudes upward from the liquid level. The remaining amount of the liquid detergent 41 is about 30 ml, and the amount of the liquid detergent 41 whose remaining amount is detected with respect to the volume of the container 90 is actually suppressed to a small ratio of 5%.

  Further, since the discharge port 92 is connected to the bottom of the recess 91 and the thermistor 44 is provided near the discharge port 92, the liquid level detection by the thermistor 44 detects that the remaining amount of the liquid detergent 41 is small. At that time, all of the liquid detergent 41 remaining in the concave portion 91 is poured into the washing tub 31 from the discharge port 92 via the detergent throwing means 43, so that the detergent can be used without waste until the last drop. In addition, it is economical, and since all the liquid detergent 41 can be discharged from the discharge port 92, the remaining liquid detergent 41 is not deteriorated.

(Embodiment 4)
FIG. 7 shows a cross-sectional view of the container of the electric washing machine in the fourth embodiment of the present invention. In addition, about the same part as the electric washing machine in the said embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the present embodiment, as shown in FIG. 7, a discharge portion 96 that discharges the liquid detergent 41 at a bottom portion of a container 95 that stores the liquid detergent 41, and a depth of about 10 mm at a position different from the discharge portion 96. A recess 97 is provided, and a part of the insulator 57 covering the thermistor 44 is provided so as to reach the recess 97.

  Even in this configuration, since the detection can be performed in a state of 5 mm from the bottom surface (excluding the concave portion 97) in which the remaining amount of the liquid detergent 41 is small, it is possible to suppress the remaining amount of the liquid detergent 41 in the detection state. It becomes possible.

  Further, as compared with the third embodiment, the positional relationship with the discharge port 96 can be freely designed, so that it can be realized with a relatively simple configuration.

  In each of the above embodiments, the electric washing machine having a configuration called a drum type in which the rotating drum 32 rotates on a horizontal axis has been described as an example. However, the electric washing machine is not particularly limited to this type of electric washing machine, It is possible to detect the remaining amount of liquid detergent put into the washing tub, regardless of the type of rotating shaft that is vertical or inclined, or that has no rotating drum 32, or that has rotating blades. The effect is exactly the same and does not change.

  As described above, the electric washing machine according to the present invention can surely prevent the liquid washing machine from being used when it is out of liquid detergent, and is not limited to an electric washing machine. It can be applied to various devices.

Sectional drawing of the electric washing machine in Embodiment 1 of this invention The figure which shows the structure around the thermistor of the electric washing machine Circuit diagram of the electronic circuit of the electric washing machine Sectional drawing of the electric washing machine in Embodiment 2 of this invention The graph which shows the change of the terminal voltage V1 of the thermistor of the electric washing machine Sectional drawing of the container of the electric washing machine in Embodiment 3 of this invention Sectional drawing of the container of the electric washing machine in Embodiment 4 of this invention Sectional view of a conventional electric washing machine

Explanation of symbols

31 Washing tub 40 Container 41 Liquid detergent 43 Detergent throwing means 44 Thermistor 46, 86 Liquid level detecting means 48 Display means 57 Insulator 91, 97 Recess 92 Discharge port

Claims (9)

A container for storing the liquid detergent; a washing tub; a detergent charging means for charging the liquid detergent from the container into the washing tub; and a liquid level detecting means having a thermistor, and the liquid level of the liquid detergent in the container An electric washing machine that detects a change in electrical characteristics of the thermistor. The electric washing machine according to claim 1, wherein the thermistor is covered with an insulating material having excellent water repellency. The electric washing machine according to claim 1 or 2, wherein the container also serves as a windproof layer that prevents wind from hitting the thermistor. 4. The electric washing machine according to claim 1, wherein the liquid level detection means detects the liquid level of the liquid detergent in response to a transient phenomenon of a change in the electrical characteristics of the thermistor when the electric washing machine is started. 5. The electric washing machine according to any one of claims 1 to 4, further comprising display means for displaying a liquid level detection result of the liquid detergent by the liquid level detection means. 6. The electric washing machine according to claim 5, wherein the liquid level detection result by the liquid level detection means is displayed on the display means when the laundry is taken out or when the clothes are taken out after washing. The electric washing machine according to claim 5, wherein at the start of use, the liquid level detection result of the previous liquid level detection means is displayed on the display means. The electric washing machine according to any one of claims 1 to 7, wherein a discharge port for discharging a liquid detergent is provided in the container, and a thermistor is provided in the vicinity of the discharge port. The electric washing machine according to any one of claims 2 to 8, wherein a concave portion is provided on a bottom surface of the container, and a part of an insulator covering the thermistor is provided so as to reach the concave portion.