JP2013000530A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a washing machine that allows conductivity to be measured with high accuracy to perform control in accordance with the conductivity.SOLUTION: A washing machine is provided that includes: a housing; an outer tub anti-vibration supported within the housing and storing washing water therein; a washing and spin-drying tub rotatably supported within the outer tub and containing laundry; a driving device rotationally driving the washing and spin-drying tub; water supply means for supplying water into the outer tub; conductivity detecting means for detecting conductivity of water used for washing; and a control unit controlling the driving device and the water supply means to allow at least a washing operation to be performed. The conductivity detecting means is formed of electrodes facing each other. A capacitor is provided in a negative feedback circuit including these electrodes and a transformer. An element for discharging the charge accumulated in this capacitor is provided.

Description

  The present invention particularly relates to a washing machine having a function of measuring water hardness used for washing.

  The washing machine performs a washing operation of clothes with washing water obtained by dissolving detergent in tap water. The tap water supplied to the washing machine contains hardness components such as calcium and magnesium. Since the hardness component is combined with the surfactant, which is the main component of the detergent, to form soap scum, the amount of the surfactant in the wash water is reduced, which causes a reduction in cleaning power. In addition, the hardness of tap water varies from region to region and varies from season to season. For this reason, there is a need for a washing machine that calculates the amount of detergent from the hardness of water used for washing and performs an appropriate operation.

  The following Patent Document 1 includes a pair of electrodes for measuring the electric conductivity of washing water in an outer tub in which the washing water is accumulated, and the hardness of the washing water is converted from the measured electric conductivity of the washing water, A washing machine that performs a washing process according to hardness is disclosed.

JP 2009-195737 A

  The washing machine disclosed in Patent Document 1 is provided with a pair of electrodes so as to protrude into the outer tub from the bottom surface of the air chamber provided in the outer tub. In the washing machine provided with such a structure, there is a problem that the conductivity changes with the passage of time even though the conductivity does not change. In addition, when measuring conductivity over a wide range, there is a problem that accuracy is lowered.

  This invention solves the said subject, The objective is to provide the washing machine which can measure electrical conductivity accurately and can perform control according to the electrical conductivity.

  A housing; an anti-vibration support in the housing; and an outer tub for storing washing water therein; a washing and dewatering tub that is rotatably supported in the outer tub and stores laundry; and the washing and washing A drive device for rotationally driving the dehydration tub, water supply means for supplying water into the outer tub, conductivity detection means for detecting the conductivity of water used for washing, and controlling the drive device and the water supply means. In a washing machine having a control unit capable of executing at least a washing operation, the conductivity detecting means is formed of electrodes facing each other, a capacitor is provided in a negative feedback circuit having these electrodes and a transformer, and the capacitor is accumulated in the capacitor. An element for discharging electric charge was installed.

  ADVANTAGE OF THE INVENTION According to this invention, the washing machine which measures the hardness (electrical conductivity) of the water used for washing with high precision, and can wash efficiently can be provided.

It is an external appearance perspective view of the washing machine which concerns on this embodiment. It is the right sectional view which cut and showed a part of case and an outer tub in order to show the internal structure of the washing machine concerning this embodiment. It is a perspective view which shows an electrode single-piece | unit. FIG. 3 is a cross-sectional view of the conductivity detecting means 11 in FIG. 2. The details of the control device 16 are shown in a block diagram. Conductivity circuit 1. Conductivity circuit 2 with improved measurement accuracy of conductivity. Conductivity circuit 3 with improved measurement accuracy of conductivity. Conductivity circuit 4 with improved measurement accuracy of conductivity. Conductivity circuit 5 with improved measurement accuracy of conductivity.

  Hereinafter, modes for carrying out the present invention (hereinafter referred to as “embodiments”) will be described in detail with reference to the drawings as appropriate. In the present description, the same constituent elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is an external perspective view of a washing machine (washing / drying machine) according to the present embodiment.

  The washing machine 1 is a vertical washing machine in which the rotation axis of the washing and dewatering tub 7 (see FIG. 2) is substantially vertical. First, an outer lid 2 is provided on the upper part of the casing of the washing machine 1. In addition, the outer lid 2 is opened by opening to the rear side while being bent in a mountain shape, and clothes (laundry) can be taken in and out of the washing and dewatering tub 7 (see FIG. 2). A water supply port 3 from the water tap 3 and a power switch 5 are provided on the upper surface of the washing machine 1, and an operation display panel 6 including an operation switch and a display is provided on the front side of the outer lid 2. A drain port 4 is provided at the lower part of the washing machine 1.

  FIG. 2 is a right-side sectional view showing a part of the casing and the outer tub 8 in order to show the internal structure of the washing machine 1 according to the present embodiment. The washing / dehydrating tub 7 for storing clothes has a substantially bottomed cylindrical shape and is rotatably supported in the outer tub 8.

  The outer tub 8 is supported in an anti-vibration manner in the housing and encloses the washing and dewatering tub 7 on the same axis. The outer tub 8 is formed of a disc-shaped bottom wall portion and a cylindrical peripheral wall portion, and has a structure in which an upper side is opened, and stores washing water therein. Further, the outer tub 8 is provided with two electrodes P1 and P2 parallel to each other as the conductivity detecting means 11 for detecting the conductivity of water used for washing, and this conductivity detecting means. 11 is connected to the control device 16.

  A rotary blade 10 is provided on the inner bottom surface of the washing and dewatering tub 7, and a motor 9 is provided on the outer center of the bottom surface of the outer tub 8. The motor 9 penetrates the outer tub 8 and is coupled to the washing / dehydrating tub 7 and the rotary blade 10 to rotate the washing / dehydrating tub 7 and the like. Furthermore, the motor 9 includes a rotation detection device 12 configured by a Hall element or a photo interrupter that detects the rotation.

  The water supplied from the water supply port 3 is poured into the outer tub 9 from between the outer tub 8 and the washing / dehydrating tub 7 through the water supply means. The bottom surface of the outer tub 8 has a hole for draining, and is connected to the drain port 4 via the drain valve 13. Further, the circulation pump 15 sprinkles water from the upper part of the washing and dewatering tank 7 into the washing and dewatering tank 7 through the lower communication pipe 14 to circulate water.

  Further, the control device 16 stores the conductivity detected by the conductivity detection means 11 or the hardness obtained from the conductivity, and the conductivity / hardness storage unit and the conductivity / hardness storage unit. According to the electric conductivity detected by the electric conductivity detection means 11 after this determination, it has a controller for determining the amount of detergent, the washing time, the rinsing time and the dehydrating time using the electric conductivity or hardness at the previous operation. Change at least one of the washing time, rinsing time, and dewatering time. In addition, the control unit 16 controls the motor 9 and the water supply means to give a command for operating the washing process and the like.

  The conductivity detection means 11 is attached to the lower part of the outer tub 8. The single electrode P constituting the conductivity detecting means 11 has the shape shown in FIG. 3, and as shown in FIG. 4, the pair of electrodes P1 and P2 are fixed by an insulator 17 and have a constant interval. It is installed in the state of providing.

  As shown in FIG. 5, the control device 16 calculates the optimum washing condition by the microcomputer 22 based on the values of the operation SW 18, the water temperature sensor 19, the water level sensor 20, and the conductivity, and the operation time of the motor 9 Washing is performed by controlling the water supply valve 23 and the drain valve 24. Further, the conductivity detecting means 11 constitutes a negative feedback in an oscillation circuit comprising resistors R1 to R6, capacitors C1 to C3, operational amplifiers OP1 and 2, transformer T1, electrodes P1 and P2 as shown in FIG. Detection can be performed by changing the impedance of the electrodes P1 and P2.

  Next, the detail of the function which measures electrical conductivity is demonstrated. As shown in FIG. 6, the electrodes P1, P2 facing each other are provided in the outer tub 8, and are connected to the first capacitor C1 and the second capacitor C2 on the secondary side via a transformer T1. Then, the conductivity is calculated by converting the change in impedance between the electrodes P1 and P2 into a frequency by an oscillation circuit. The transformer T1 is provided to insulate the electrodes P1 and P2, and the first capacitor C1 and the second capacitor C2 are provided to further insulate and protect double.

  Here, if charges accumulate in the first capacitor C1 and the second capacitor C2, the oscillation frequency may be shifted, and accurate conductivity may not be measured. For this reason, a method of connecting the primary side and the secondary side of the transformer with a resistance of several megaohms is conceivable, but in that case, sufficient insulation cannot be secured. Therefore, in the present embodiment, as shown in FIG. 7, a resistor R7 is connected in parallel to the first capacitor C1 as an element for discharging the electric charge accumulated in the first capacitor C1. For this reason, the charge can be released, the impedance between the electrodes P1 and P2 can be accurately measured, and the conductivity can be accurately measured. Even if the added resistor R7 is inserted in parallel with the second capacitor C2, the same effect can be obtained.

  Further, as shown in FIG. 8, the same effect can be obtained by replacing the resistor R7 in place of the first capacitor C1. That is, the change in conductivity can be eliminated by changing at least one of the capacitors C1 and C2 to an element capable of flowing a direct current such as a resistor or a coil.

  Further, in FIG. 9, as in FIGS. 7 and 8, the conductivity detecting means 11 is configured by a negative feedback circuit having electrodes P1 and P2 facing each other and a transformer T1, but in FIGS. Unlike the capacitor, the negative feedback circuit is not provided with the first capacitor C1 and the second capacitor C2, but is provided with resistors R7 and R8 instead of these capacitors. Even with such a configuration, it is possible to detect the conductivity with high accuracy as in FIGS.

  The circuit 6 can measure a wide variety of electrical conductivity including water, detergent, dirt, etc., because water close to pure water has low electrical conductivity, and water contaminated with mud is mixed with electrolyte. High conductivity. When an attempt is made to measure a wide range of conductivity, the output (oscillation) frequency with respect to the conductivity draws a curve such as a cubic curve, and the error increases even if an approximate expression is used. Therefore, the range of conductivity to be measured is clarified, and the resistance R2 and the third capacitor C3 that determine the oscillation frequency are adjusted so that the range can be quadratic approximated in the cubic curve. Is required.

  The washing machine 1 includes a plurality of processes such as washing, dehydration, and rinsing. Therefore, as shown in FIG. 10, it is possible to accurately measure the conductivity with a circuit suitable for each process by appropriately switching the resistor R2 and the capacitor C3 that determine the oscillation frequency by the switching units SW1 and SW2 for each process. It becomes. In addition, the switching units SW1 and SW2 can be switched to resistors or capacitors according to the degree of contamination or the like based on a command from the microcomputer 22 or the like, and can be changed to circuit constants according to the degree of conductivity to be measured.

DESCRIPTION OF SYMBOLS 1 Washing machine 2 Outer lid 3 Water supply port 4 Drainage port 5 Power switch 6 Operation display panel 7 Washing / dehydration tub 8 Outer tub 9 Motor 10 Rotary blade 11 Conductivity detection means 12 Rotation detection device 13 Drain valve 14 Lower connection pipe 15 Circulation Pump 16 Controller 17 Insulator 18 Operation SW
19 Water temperature sensor 20 Water level sensor 21 Conductivity circuit 22 Microcomputer 23 Water supply valve

Claims (5)

A housing; an anti-vibration support in the housing; and an outer tub for storing washing water therein; a washing and dewatering tub that is rotatably supported in the outer tub and stores laundry; and the washing and washing A drive device for rotationally driving the dehydration tub, water supply means for supplying water into the outer tub, conductivity detection means for detecting the conductivity of water used for washing, and controlling the drive device and the water supply means. In a washing machine having a control unit capable of executing at least a washing operation,
The electric conductivity detecting means is formed of electrodes facing each other, a capacitor is provided in a negative feedback circuit having these electrodes and a transformer, and an element for discharging the electric charge accumulated in the capacitor is installed. A housing; an anti-vibration support in the housing; and an outer tub for storing washing water therein; a washing and dewatering tub that is rotatably supported in the outer tub and stores laundry; and the washing and washing A drive device that rotationally drives the dewatering tank, a water supply means that supplies water into the outer tank, a control unit that controls the drive apparatus and the water supply means to perform at least a washing operation, and an electric conductivity having electrodes facing each other In the washing machine comprising a detection means, calculating the conductivity by converting the change in impedance between the electrodes into a frequency by an oscillation circuit, and controlling the washing operation by the control unit according to the calculated conductivity,
The secondary side of the transformer that insulates the electrode is provided with a first capacitor and a second capacitor for further insulation, and a resistor or a coil is provided in parallel with at least one of these capacitors. A washing machine featuring.   3. The washing machine according to claim 2, wherein a resistor or a coil is provided instead of the first capacitor or the second capacitor.   The washing machine according to claim 2, wherein a resistor or a coil is provided instead of the first capacitor and the second capacitor.   3. The washing machine according to claim 2, further comprising a switching unit that selects the third capacitor and the resistance that determine the oscillation frequency according to the degree of conductivity to be detected.