JP6966494B2 - Washing machine - Google Patents

Description

The present invention relates to a washing machine for washing clothes and the like.

Patent Document 1 describes, "In a washing machine that sprays hot water into a washing / dehydrating tank in the form of mist, abnormal heating of the heater is prevented when the supply of water from the outside is stopped or insufficient." ing.

Japanese Unexamined Patent Publication No. 2006-51293

However, in Patent Document 1, when the water stored in a certain space is heated by the heater, it is determined by the water level sensor whether or not the amount of water that the heater does not burn is present in the space, and the water is determined. Since it is determined whether the amount causes abnormal heating of the heater, for example, when the water level sensor fails or when the water level sensor water level detection signal cannot be transmitted correctly (for example, an error in the water level reading due to the generation of foreign matter, etc.) ), Such a judgment was not made properly, and the heater was heated in an empty-fired state, which could lead to ignition of the worst product.

Therefore, an object of the present invention is to provide a washing machine capable of appropriately preventing abnormal heating of the water heating unit even when the water level detecting unit does not operate correctly.

In order to solve such a problem, for example, the washing machine according to the present invention has an outer tub for storing water, an inner tub rotatably supported in the outer tub and accommodating clothes, and an outer tub. A water supply unit that supplies water, a water heating unit that heats the water supplied in the outer tank, a water level detection unit that detects the water level in the outer tank, and an electric conductivity measurement that measures the electrical conductivity of a predetermined section in the outer tank. It has a unit and a control unit that controls a water level detection unit and an electric conductivity measuring unit, and the control unit determines that the water level is equal to or higher than a predetermined water level based on the detection result of the water level detecting unit, and measures the electric conductivity. The configuration is such that the start of heating of the water heating unit is controlled when it is determined that the detection result of the unit is equal to or higher than a predetermined threshold value.

According to the present invention, it is possible to provide a washing machine capable of appropriately preventing abnormal heating of the water heating unit even when the water level detecting unit does not operate correctly.

It is an external perspective view which shows the drum type washer-dryer which concerns on this invention. It is a side view which shows the internal structure of the vertical cross section of the drum type washer-dryer of FIG. It is a figure which shows one structural example of the heater of the drum type washer-dryer which concerns on this invention. It is a perspective view which shows the structure near the bottom surface of the outer tub of the drum type washer-dryer of FIG. It is a flowchart which shows the flow of the washing process of the drum type washer-dryer of FIG. It is a flowchart which shows the flow of the control process of the pre-washing process of FIG. It is a flowchart which shows the flow of the control process of the main washing process A of FIG. It is a flowchart which shows the flow of the control process of the main washing process B of FIG.

Next, the drum-type washer-dryer according to the embodiment of the present invention will be described in detail with reference to the drawings as appropriate.

First, the overall configuration of the drum-type washer-dryer will be described mainly with reference to FIGS. 1 and 2. FIG. 1 is an external perspective view showing a drum-type washer-dryer of the present embodiment. FIG. 2 is a side view schematically showing the internal structure of the drum-type washer-dryer housing of FIG. 1 with the side plates removed. The front-back, up-down, left-right directions in the following description are based on the front-back, up-down, left-right directions shown in FIG.

The housing 1 constituting the outer shell is mounted on the base 4, and is composed of left and right side plates 6, a front cover 5, a back cover 2, and a top cover 7. The front cover 5 is composed of an upper front cover 5a and a lower front cover 5b. The left and right side plates 6 are connected by a U-shaped upper reinforcing material, a front reinforcing material, and a rear reinforcing material (none of which are shown) to form a box-shaped housing 1 including the base 4. There is.

A door 3 provided in the substantially center of the front cover 5 for closing an inlet for putting in and taking out clothes, and is supported by a hinge (not shown) provided on the front reinforcing material so as to be openable and closable. By pulling the handle 3a, the lock mechanism (not shown) is released and opened, and by pressing the door 3 against the front cover 5, the door 3 is locked and closed. The front reinforcing material has a circular opening for putting in and taking out clothes concentrically with the opening of the outer tank 15 described later.

The operation panel 8 provided in the center of the upper part of the housing 1 includes a power switch 8a and an operation button 8b, and is electrically connected to a control device 27 which is a control unit provided in the upper part of the housing 1. ..

The detergent container 13 provided on the upper left side in the housing 1 is used when detergents are poured from the upper part of the housing when washing. To put detergents, open the detergent lid 9. Further, the water outlet 13a is provided slightly behind the left side surface of the detergent container 13. Therefore, the bottom surface of the detergent container 13 is formed in a mortar shape so that the position of the water outlet 13a is the lowest.

Water supply-related parts such as a water supply solenoid valve 11, a bath water absorption pump 12, and a water level sensor 25 are provided on the rear side of the detergent container 13. The upper opening of the detergent container 13 is provided with a water supply unit 10 which is a water supply unit. The upper surface cover 7 is provided with a water supply hose connection port 11a from a water tap and a water absorption hose connection port 12a for the remaining hot water of the bath.

The drum 14 (inner tank), which is a rotatably supported cylindrical washing / dehydrating tank, has a large number of through holes (not shown) in its outer peripheral wall and bottom wall for water passage and ventilation, and is on the front side. The end face is provided with an opening (not shown) for putting in and taking out clothes.

A fluid balancer 14b integrated with the drum 14 is provided on the outside of the opening. This fluid balancer 14b is formed in a ring shape made of synthetic resin or the like, and is configured by enclosing a fluid having a large specific gravity (salt water or the like) inside. It has a function of canceling the eccentricity by moving the fluid in the fluid balancer 14b and maintaining the balance of rotation. Further, the rotation center axis of the drum 14 is inclined so as to be horizontal or higher on the opening side.

The cylindrical outer tank 15 includes the drum 14 coaxially, the front surface is open, and the motor 18 is attached to the outer center of the rear end surface. The rotating shaft of the motor 18 penetrates the outer tank 15 and is coupled to the drum 14. An outer tank cover 16 that allows water to be stored in the outer tank 15 is provided at the opening on the front surface. The outer tank 15 is vibration-proof supported by a damper 17 whose lower side is fixed to the base 4. Further, the rubber bellows 19 seals the outer tank 15 with water by closing the door 3.

At the rear of the side surface of the outer tank 15, a water supply port 15a for supplying water and detergents into the outer tank 15 is provided. The water supply port 15a and the water outlet 13a of the detergent container 13 are connected by a rubber bellows hose 20. A concave recess 15b is provided on the bottom inner peripheral surface of the outer tank 15 so as to extend in the axial direction of the outer tank 15. The bottom surface of the recessed portion 15b is an inclined surface that descends from the front side to the rear side, and a drainage port 21 is provided on the rear side of the recessed portion 15b. A bellows hose 22 is connected to the drain port 21 via a joint 21a and is connected to the circulation pump 23.

The circulation pump 23 ejects the detergent water accumulated at the bottom of the outer tub 15 from the shower outlet 23a provided on the upper part of the outer tub cover 16 via a circulation path (not shown) to discharge high-concentration detergent water to the laundry. By spreading it throughout, it has both detergency and water saving.

Further, one end of the drain hose 24 is connected to a drain valve 24a provided at the drain port portion of the circulation pump 23, and the other end side extends to the outside of the machine.

The water level sensor 25, which is a water level detection unit, is connected to the bottom of the outer tank 15 by a vinyl tube 26, and detects the water level by measuring the pressure inside the outer tank 15.

The control device 27, which is a control unit, has an electric conductivity measuring unit, and controls the water level detecting unit and the electric conductivity measuring unit. The conductivity measuring unit detects the conductivity (hardness) of the supplied water via the conductivity sensor 28 arranged at the inner bottom of the outer tank 15.

A heater 29, which is a water heating unit, is mounted on the bottom surface of the outer tub, and by heating the washing water inside the outer tub 15, the amount of undissolved detergent in the washing water is reduced, and the detergent enzyme dissolved in the washing water is used. It can promote the work and improve the cleaning performance. Further, a thermistor 29b, which will be described later, is provided as a temperature detecting means in the vicinity of the heating portion 29a.

In the present invention, the control device 27, which is a control unit, controls the start of heating of the water heating unit based on the detection result of the water level detection unit and the measurement result of the conductivity measurement unit. This means that the water level can be detected by the conductivity measuring unit even when the water level detecting unit is not operating, and the water heating unit is not submerged in water, that is, the water heating unit is empty. It is possible to prevent abnormal heating in the heating state, that is, to realize a double dry heating prevention mechanism, and to further improve the safety of the product.

As shown in FIG. 4, in the conductivity sensor 28, two electrodes 28a are arranged to face each other, and the electrical conductivity is calculated by measuring the electric resistance value between the electrodes 28a. Therefore, it is used as a means for detecting the hardness of water by measuring the electrical conductivity of water existing between the electrodes. In addition, it can be used as a means to determine the presence or absence of water inside the outer tank 15 by utilizing the difference in electrical resistance between water and air, or by measuring changes in the electrical conductivity of water to make a detergent solution. It is possible to detect the concentration and the dirt concentration in the detergent solution.

FIG. 3 shows the structure of the heater 29. The heater 29 includes a heating unit 29a for heating the water in the tank, a thermistor 29b for detecting the temperature inside the tank during temperature control, a rubber packing 29c for sealing the water in the outer tank, and a heater 29. It is composed of a flange 29d for attaching to the outer tank 15, a flange 29e, a screw 29f, and a nut 29g, and the screw 29f is fixed to the flange 29d by crimping.

When the nut 29g is tightened with the heater 29 inserted until the flange 29e and the outer tank 15 come into contact with the hole (not shown) that has a shape similar to that of the rubber packing 29c and is slightly larger than that provided in the outer tank 15, the screw 29f and the nut The distance between the flange 29d and the flange 29e is narrowed by 29 g, and the rubber packing 29c between them is compressed in the longitudinal direction of the heater 29 and swells toward the entire surface in the direction perpendicular to the longitudinal direction, thereby exerting a pressing force on the hole of the outer tank 15. Seal the water and fix the heater 29.

A coiled heating wire 29h is passed through the heating portion 29a inside the metal tube, and the heating wire 29h is covered with an insulating powder (not shown) to fix the heating wire 29h and to connect the metal tube and electricity. It is insulated from the heat ray 29h. Thermal fuses (not shown) are provided at both ends of the heating wire 29h, and the fuse is blown when the temperature of the heater 29 itself rises excessively due to abnormal heating, forcibly shutting off the power supply.

FIG. 4 shows the structure of the bottom of the outer tank. The conductivity sensor 28 is attached at a position higher than the heater 29 when viewed at a horizontal height, and if the conductivity sensor 28 determines that there is water, the water has accumulated to a height at which the entire heater 29 is submerged in water. It has a structure that can prevent the heater from being heated in the empty state. Further, a stainless steel heater cover 30 is attached to the bottom surface of the outer tank 15, so that even if the sensors do not work at all and the heater is in an empty state, the fire does not spread to peripheral parts. It has a structure.

FIG. 5 shows a control flow of a washing operation using hot water in the present embodiment.

First, when the operation of the washing machine is started, in the sensing process of S1, the drum 14 is rotated by the connected motor 18, and the current of the motor 18 at that time is measured to measure the amount of laundry clothes put into the drum 14. The measurement is performed to determine the amount of water used during operation and the rotation control content of the drum 14.

After that, in the water supply process of S2, the water supply solenoid valve 11 opens, water is supplied into the outer tank 15 via the water supply unit 10 which is a water supply unit, and the water level of the water accumulated in the outer tank 15 is set in the outer tank in step S201. The water level is detected using the water level sensor 25, which is a water level detection unit connected to the tube, and if the water level does not reach a certain level within a certain period of time, the operation is stopped because the water supply solenoid valve 11 or the drain valve 24a is considered to be abnormal. , The error is left on the buzzer or the operation panel 8 to notify the user of the abnormality. After reaching a certain water level, the water supply solenoid valve 11 closes and the water supply is automatically stopped, and the process proceeds to the washing process.

The washing step is classified into a pre-washing step of S3 and a main washing step of S4 and S5. In the pre-washing step S3, as shown in FIG. The detergent is prepared (detergent melting step), and in step S302, the high-concentration detergent solution is sprayed on the entire clothes in the tank by the circulation pump 23 (circulating water spraying step) and permeated. After that, water is supplied again in step S303 to store water in the tank (water supply step), and then in step S304, the rotation speed of the drum is increased to a certain level or higher so that the clothes are attached to the inner surface of the drum 14 by centrifugal force. Perform a push-washing process to wash by spraying a shower.

After that, the process proceeds to the main washing step A of S4, additional water is supplied in step S401 as shown in FIG. 7, the water level sensor 25 determines that the water level is equal to or higher than the reset water level Tr, and then the electric conductivity in step S402. The value of the sensor 28 is read, and if it is equal to or higher than a certain value (predetermined threshold value), the process proceeds to the next step (step S403). The step of heater control in the washing step is skipped, the main washing step A is carried out until the specified time without using the heater 29, and then the transition to the main washing step B of S5.

The heater 29 is turned on in step S403, and the current value is measured in the following step S404 to determine whether or not a current value equal to or higher than a predetermined predetermined value flows. If the current value is less than or equal to the specified value at this stage, it is determined that the heater 29 is disconnected, the subsequent step of hot water washing using the heater 29 is skipped, and the main washing step A is performed without using the heater 29. It is carried out until the specified time, and then the process proceeds to the main washing step B of S5.

In step S404, if the current value when the sheathed heater is conducting is equal to or higher than the specified value, it is determined that the heater 29 is in a normally connected state without disconnection or disconnection of the connection terminal, and the process proceeds to the next step S405, and the heater is transferred to. After turning off 29, the current value in the heater 29 OFF state is measured in step S406, and it is determined whether the current value is less than the specified value. At this time, if the current value is equal to or higher than the specified value, it is determined that the control circuit of the heater 29 is short-circuited, a series of operations are terminated for safety, and the power supply of the main body is turned off.

After that, after the stirring operation in step S407, the numerical value of the water level sensor 25 is read in step S408, and if the water level at that time is lower than the reset water level Tr, water supply in step S409 is performed. If the water level is higher than the reset water level Tr, the water supply operation in step S409 is skipped and the process proceeds to the stirring operation in step S410. After these steps from steps S408 to S410, it is determined in step S411 whether the specified time has elapsed, and if it is less than the specified time, the process returns to the water level determination in step S408, and this is repeated until the specified time elapses. Wash clothes. In these steps, cleaning is performed at room temperature without turning on the heater 29.

After that, when the transition to the main washing step B (S5) occurs, as shown in FIG. 8, first, in step S501, it is determined whether the reading value of the water level sensor 25 is equal to or higher than the reset water level Tr, and when the water level is equal to or higher than the reset water level Tr. Measures the value of the conductivity sensor 28 in the next step S502, and determines whether or not the value is equal to or greater than the threshold value. If it is less than the reset water level Tr, the process proceeds to step S503, and water is supplied until the water level in the tank becomes equal to or higher than the reset water level Tr.

If the value of the conductivity sensor 28 is less than the threshold value in step S502, it is determined that the actual water level has dropped to the height at which the heating portion 29a of the heater 29 is exposed due to a failure of the water level sensor 25 or the like, and the heater 29 is used. Not transition to the normal washing process. If the reading value of the conductivity sensor 28 is equal to or higher than the threshold value, it is determined that the heater 29 can be heated in a safe state because the heater 29 is completely submerged, and the process proceeds to the next step S504.

That is, in addition to detecting that the water level sensor 25 has supplied water to the amount of water that the heater 29 is completely submerged in the drum 14, the electric conductivity sensor 28 detects that the water level has risen to a predetermined height, and then the heater. 29 controls to start heating the water in the drum 14. By controlling in this way, even if the value detected by the water level sensor 25 due to some abnormality is incorrect, the measurement result of the conductivity sensor 28 can be seen, and the heater can be suppressed from being heated.

In step S504, the water temperature is read by the thermistor 29b, and if the temperature is TL or less, the heater 29 is turned on in step S505 to raise the water temperature. After that, in step S505, the water temperature is also measured by the thermistor 29b, and if the temperature is TH or less than the set temperature, the transition to step S507 is performed, and stirring is continued for a specified time ta (for example, 3 minutes) while the heater is kept ON. Then, after the lapse of the specified time ta, the process proceeds to step S508, and it is determined whether or not the operation time of the main washing process has been completed. If the operation time has not been completed, the process returns to step S506 and the water temperature determination by the thermistor 29b is performed again. ..

If the operation time of the main washing step B has elapsed at the time of step S508, the heater 29 is turned off in step S509, and then the process proceeds to the next step, the rinsing step S6.

If the detection temperature of the thermistor 29b is higher than the set temperature TH in step S506, the process proceeds to step S510, the heater 29 is turned off, the stirring operation is continued for a specified time ta in step S511, and then in step S512. It is determined whether the operation time of the main washing step B is completed. If it is determined that the operation time has ended, the process proceeds to the rinsing step S6 as it is, and if it is determined that the operation time has not ended, the process returns to step S501, and the water level is detected again by the water level sensor 25 and the conductivity sensor 28. Then, each step is repeated until the end of the operation time of the main washing step B.

If the water temperature detected in step S504 is higher than the set temperature TL, the transition to step S511 is performed while maintaining the heater OFF state, and the rest is as described above. At this time, by setting the relationship between the set temperature TL and TH so that TL <TH and repeating the steps S501 to S512 described above, the water temperature of the water stored in the tank by the heater 29 such as a sheathed heater is repeated. Is heated until it exceeds the set temperature TH, and when the set temperature TH is exceeded, the heater 29 is turned off, and then when the water temperature in the tank drops and becomes lower than the set temperature TL, the heater 29 is turned on and heating resumes. Will be done. This operation is repeated until the end of the main washing B operation time, and the clothes are washed with warm water to enhance the washing power of the laundry.

In the rinsing step S6, the drum 14 is rotated at high speed as an intermediate dehydration operation (not shown), and the washing liquid soaked in the laundry is squeezed out by the rotational centrifugal force of the tub and drained to the outside of the machine from the drainage path. By repeating the intermediate dehydration and water supply operation a set number of times, the detergent components contained in the clothes are scattered and removed together with the water.

After that, the process proceeds to the dehydration step S7, and the drum 14 is rotated at high speed to disperse and remove the moisture in the clothes.

If the washing / drying operation is set, then the drying step S8 is executed to dry the laundry.

After the operation is completed, a series of operation control is terminated.

By performing the above control, in the washing machine of the present embodiment, in addition to the water level detection control by the water level detection unit (water level sensor 25), the water level detection control by the electric degree measuring unit (electricity sensor 28) is performed, and the electric conductivity is performed. When the reading value of the sensor 28 is less than or equal to the specified value, that is, when the water level is lower than the specified value, the main washing step is performed with the heater 29 turned off to prevent abnormal heating in the heater empty heating state, that is, double. It is possible to realize a mechanism to prevent empty heating and further improve the safety of the product.

In the present embodiment, the drum-type washer-dryer has been described, but by changing the arrangement and control contents of the sensor and the heater within the scope of the present invention, a so-called vertical washer-dryer and a drying mechanism can be obtained. The present invention can be applied to a washing machine that does not have one.

Further, in the present embodiment, the method of measuring the electric conductivity of the water in the outer tank by using the electric conductivity sensor 28 as a means for detecting the water level has been described. However, for example, the water level can be measured by combining a float and a mechanical switch. A means for detecting may be used.

1 Housing 3 Door 10 Water supply unit 14 Drum 15 Outer tank 16 Outer tank cover 18 Motor 25 Water level sensor 27 Control device 28 Conductivity sensor 29 Heater 30 Heater cover

Claims (3)

An outer tank for storing water and
The inner tank, which is rotatably supported in the outer tank and accommodates clothing,
The water supply unit that supplies water to the outer tank and
A water heating unit that heats the water supplied to the outer tank,
A water level detection unit that detects the water level in the outer tank,
An electric conductivity measuring unit that measures the electric conductivity of a predetermined section in the outer tank,
It has a water level detection unit and a control unit that controls the conductivity measurement unit.
Wherein, the water if the water level by the detection result of the water level detection unit determines that is not less than a predetermined level, and the detection result of the conductivity measurement unit is equal to or more than the predetermined threshold value A washing machine characterized in that it controls the start of heating of a heating unit. The washing machine according to claim 1.
A washing machine in which the conductivity measuring unit is provided at a position higher than the water heating unit. The washing machine according to claim 2.
In addition to detecting that the water level detecting unit has supplied water to the inner tank to the extent that the water heating unit is completely submerged, the control unit raises the water level to a predetermined height by the conductivity measuring unit. A washing machine that starts heating the water in the inner tank by the water heating unit after detecting that.

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