CN111676647A - washing machine - Google Patents

Abstract

The present invention provides a washing machine that can appropriately prevent abnormal heating of a water heating unit even when the water level detection does not operate correctly. The washing machine comprises: an outer tub (15) for storing water; a drum (14) rotatably supported in the outer tub (15) and capable of accommodating clothes; a water supply unit (10) for supplying water in the outer tub (15); A heater (29) for heating the water supplied into the outer tub (15); a water level sensor (25) for detecting the water level in the outer tub (15); conductivity for measuring the conductivity of the water in the outer tub (15) a rate sensor (28); and a control device (27) for controlling the water level sensor (25) and the conductivity sensor (28), the control device (27) based on the detection result of the water level sensor (25) and the measurement of the conductivity sensor (28) As a result, the heater (29) is controlled to start heating.

Description

washing machine

technical field

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

Background technique

Patent Document 1 describes a technique of "preventing abnormal heating by a heater when water supply is stopped from outside or when water supply is insufficient in a washing machine that sprays warm water into a washing and dewatering tub in the form of a mist."

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2006-51293

SUMMARY OF THE INVENTION

The technical problem to be solved by the invention

However, in Patent Document 1, when water stored in a certain space is heated by a heater, a water level sensor determines whether or not there is an amount of water in the space that the heater does not burn empty. It becomes the cause of abnormal heating of the heater, so for example, when the water level sensor fails or the water level sensor cannot send the water level detection signal correctly (for example, the presence of foreign objects causes errors in the water level reading value, etc.), such The judgment is no longer appropriate, the heater is heated in an empty burning state, and there is even a possibility of fire.

Then, the objective of this invention is to provide the washing machine which can prevent abnormal heating of a water heating part appropriately even when a water level detection part does not operate correctly.

technical means for solving technical problems

In order to solve such a technical problem, for example, the washing machine of the present invention includes: an outer tub for storing water; an inner tub rotatably supported in the outer tub and capable of storing clothes; and a water supply to the outer tub a water supply unit; a water heating unit that heats water supplied into the outer tub; a water level detection unit that detects the water level in the outer tub; a conductivity measuring unit that measures the conductivity of the water in the outer tub and a control unit that controls the water level detection unit and the conductivity measurement unit, the control unit controls the start of heating of the heating unit based on the detection result of the water level detection unit and the measurement result of the conductivity measurement unit.

Invention effect

According to the present invention, it is possible to provide a washing machine that can appropriately prevent abnormal heating of the water heating unit even when the water level detection unit does not operate correctly.

Description of drawings

FIG. 1 is an external perspective view showing the drum-type washing and drying machine of the present invention.

Fig. 2 is a side view showing an internal structure in a longitudinal section of the drum-type washing and drying machine of Fig. 1 .

Fig. 3 is a diagram showing a configuration example of a heater of the drum-type washing and drying machine of the present invention.

Fig. 4 is a perspective view showing a structure in the vicinity of the bottom surface of the tub of the drum-type washing and drying machine of Fig. 1 .

Fig. 5 is a flowchart showing a flow of a washing process in the drum-type washing and drying machine of Fig. 1 .

FIG. 6 is a flowchart showing a flow of control processing in the pre-washing process of FIG. 5 .

Fig. 7 is a flowchart showing a flow of control processing of the main washing step A of Fig. 5 .

FIG. 8 is a flowchart showing the flow of the control process of the main washing step B of FIG. 5 .

Detailed ways

Next, the drum-type washing and drying machine according to the embodiment of the present invention will be described with reference to the drawings as appropriate.

First, the overall structure of the drum-type washing and drying machine will be described mainly with reference to FIGS. 1 and 2 . FIG. 1 is an external perspective view showing a drum-type washing and drying machine according to the present embodiment. Fig. 2 is a side view schematically showing the internal structure of the drum-type washing and drying machine of Fig. 1 after removing the side plate of the casing. The directions of front, back, up, down, left, and right in the following description are based on the directions of front, back, up, down, and left as shown in FIG. 1 .

The casing 1 constituting the outer casing is mounted on the base 4 , and includes left and right side plates 6 , a front cover 5 , a back cover 2 , and a top cover 7 . The front cover 5 includes an upper front cover 5a and a lower front cover 5b. The left and right side plates 6 are combined by a U-shaped upper reinforcement member, a front reinforcement member, and a rear reinforcement member (none of which are shown), and together with the base 4 , form a box-shaped casing 1 .

The door 3 for closing the inlet and outlet of the clothing provided in the substantially center of the front cover 5 is supported so as to be openable and closable by a hinge (not shown) provided in the front reinforcement member. When the handle 3 a is pulled, a locking mechanism (not shown) is unlocked and opened, and the door 3 is pressed against the front cover 5 to be locked and closed. The front reinforcement member has a circular opening for allowing clothes to enter and exit, which is concentric with an opening of the tub 15 to be described later.

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

The detergent container 13 provided in the upper left side of the casing 1 is used when detergents are put in from the upper part of the casing during washing. When the detergent is put in, the detergent cover 9 is opened. Moreover, the detergent container 13 has the water outlet 13a behind the left side surface. Therefore, the bottom surface of the detergent container 13 is formed into a mortar shape so that the position of the water outlet 13a is the lowest.

On the rear side of the detergent container 13, water supply-related components such as a water supply solenoid valve 11, a bath water suction pump 12, and a water level sensor 25 are provided. The upper part of the detergent container 13 is opened, and the water supply unit 10 as a water supply part is provided. The upper cover 7 is provided with a water supply hose connection port 11a from a water faucet, and a suction hose connection port 12a for hot water used for bathing.

The drum 14 (inner tub), which is a rotatably supported cylindrical washing and dewatering tub, has a plurality of through holes (not shown) for water and ventilation in its outer peripheral wall and bottom wall, and a front end face An opening (illustration omitted) through which clothes can be taken in and out is provided.

A fluid balancer 14b integrated with the drum 14 is provided outside the opening. The fluid balancer 14b is formed of a synthetic resin or the like in an annular shape, and is configured to enclose a fluid (salt water, etc.) with a large specific gravity inside, and is used for fluid balance when eccentricity occurs due to unbalanced laundry or the like during rotation of the drum 14 . The movement of the fluid in the member 14b eliminates the eccentricity, and has the function of maintaining the balance of the rotation. In addition, the rotation center axis of the drum 14 is horizontal or inclined so that the opening portion side is higher.

The cylindrical outer tub 15 encloses the drum 14 coaxially, the front surface is open, and the motor 18 is attached to the center of the outer side of the rear end surface. The rotating shaft of the motor 18 penetrates the outer tub 15 and is combined with the drum 14 . A tub cover 16 capable of storing water in the tub 15 is provided at the opening of the front surface. The lower side of the outer tub 15 is supported in a vibration-proof manner by a damper 17 fixed to the base 4 . In addition, the rubber-made bellows 19 water-seals the outer tub 15 by closing the door 3 .

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

The circulation pump 23 sprays the detergent water stored in the bottom of the outer tub 15 through a circulation path (not shown) from the shower outlet 23a provided in the upper part of the outer tub cover 16, so that the detergent water of high concentration is spread over the laundry Overall, so as to take into account the cleaning power and water saving.

Moreover, one end of the drain hose 24 is connected to the drain valve 24a provided in the water outlet part of the circulation pump 23, and the other end side is extended to the outside of the machine.

A water level sensor 25 serving as a water level detection unit is connected to the bottom of the tub 15 by a plastic tube 26 , and detects the water level by measuring the pressure in the tub 15 .

The control device 27 as a control unit has a conductivity measurement unit, and controls the water level detection unit and the conductivity measurement unit. The electrical conductivity measuring unit detects the electrical conductivity (hardness) of the supplied water using the electrical conductivity sensor 28 arranged on the inner bottom of the outer tub 15 .

The heater 29 as a water heating unit is mounted on the bottom surface of the outer tub. By heating the wash water in the outer tub 15, the undissolved portion of the detergent in the wash water can be reduced, and the enzyme of the detergent dissolved in the wash water can be accelerated. Active to improve cleaning performance. Moreover, the thermistor 29b mentioned later is provided in the vicinity of the heating part 29a as a temperature detection means.

In this invention, the control apparatus 27 as a control part controls the heating start of a water heating part based on the detection result of a water level detection part and the measurement result of an electrical conductivity measurement part. In this way, for example, the water level can be detected by the conductivity measuring unit even when the water level detecting unit is not operating, and abnormal heating can be prevented in a state where the water heating unit is not immersed in water, that is, when the water heating unit is empty. , that is, to achieve a double anti-aircraft burning mechanism, which can further improve the safety of the product.

As shown in FIG. 4, the electrical conductivity sensor 28 has two electrodes 28a arranged to face each other, and the electrical conductivity is calculated by measuring the resistance value between these electrodes 28a. Therefore, it can be used as a means for detecting the hardness and the like of water by measuring the electrical conductivity of the water existing between the electrodes. In addition, it can also be used as a means for judging whether there is water inside the outer tub 15 by using the difference in the resistance value of water and air, or for detecting the detergent concentration of the detergent solution and the detergent solution by measuring the change in the electrical conductivity of the water. Contamination concentration in .

FIG. 3 shows the structure of the heater 29 . The heater 29 includes: a heating part 29a for heating water in the tub; a thermistor 29b for detecting the temperature in the tub during temperature control; a rubber seal 29c for water sealing the outer tub; and A flange 29d for attaching the heater 29 to the tub 15, a flange 29e, a bolt 29f, and a nut 29g, and the bolt 29f is fastened to the flange 29d by tightening.

After inserting the heater 29 into a hole (not shown) provided in the outer tub 15 and having a shape similar to that of the rubber seal 29c and a size larger, until the flange 29e is in contact with the outer tub 15, the When the nut 29g is tightened in the state, the distance between the flange 29d and the flange 29e is narrowed by the bolt 29f and the nut 29g, and the rubber seal 29c between the flange 29d and the flange 29e is compressed in the longitudinal direction of the heater 29, and the entire length of the heater 29 is compressed. The face is bulged in a direction at right angles to the longitudinal direction to apply a pressing force to the hole of the outer tub 15 , thereby fixing the water seal and the heater 29 .

The heating unit 29a is configured such that a heating wire 29h wound in a coil shape passes through the inside of a metal tube, and the circumference of the heating wire 29h is covered with insulating powder (not shown) to fix the heating wire 29h and the metal tube and the heating wire. 29h of insulation. Thermal fuses (not shown) are provided at both ends of the heating wire 29h, and when the temperature of the heater 29 itself rises excessively due to abnormal heating, the fuses are blown and the power supply is forcibly cut off.

Fig. 4 shows the structure of the bottom of the tub. The configuration is such that the conductivity sensor 28 is installed at a higher position when viewed from a height relative to the level of the heater 29, and when the conductivity sensor 28 determines that there is water, the water is stored until the entire heater 29 is immersed in water. The high state can prevent the empty burning state of the heater. In addition, the stainless steel heater cover 30 is attached to the bottom surface of the outer tub 15, so that even if the sensors are not activated and the heater is in an empty state, the heater does not spread to the surrounding parts and burn.

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

First, in the detection step S1 when the washing machine starts to operate, the drum 14 is rotated by the motor 18 connected to the drum 14, the current of the motor 18 at this time is measured to measure the amount of laundry put into the drum 14, and the operation is determined. The amount of water used and the content of rotation control of the drum 14 in

Then, in the water supply process of S2, the water supply solenoid valve 11 is opened, and water is supplied into the outer tub 15 via the water supply unit 10 as a water supply unit, and in step S201, a water level sensor 25 as a water level detection unit connected to the outer tub by a pipe is used, The water level of the water stored in the outer tub 15 is detected. If the water level does not reach a certain level within a certain period of time, it is considered that the water supply solenoid valve 11 or the drain valve 24a is abnormal and the operation is stopped. Errors are shown on 8 to inform the user of the exception. After reaching a certain water level, the water supply solenoid valve 11 is closed to automatically stop the water supply, and the process proceeds to the washing process.

The washing process is classified into the pre-washing process of S3 and the main washing processes of S4 and S5. In the pre-washing process S3, as shown in FIG. 6, in step S301, a high-concentration detergent in which the detergent is dissolved in a small amount of water is generated. liquid (detergent dissolving step), in step S302, the circulating pump 23 spreads the high-concentration detergent liquid to all the clothes in the tank (circulating water spreading step), and permeates the clothes. Then, in step S303, the water is supplied again to store water in the tub (water supply step), and in step S304, a squeeze washing step is performed, and by increasing the rotation speed of the drum to a certain value or more, the clothes are adhered to the drum 14 by centrifugal force. Spray water on the inside to clean it.

Then, the process proceeds to the main washing step A of S4. As shown in FIG. 7, additional water supply is performed in step S401, and the water level sensor 25 determines that the water level is equal to or higher than the reset water level Tr, and then the conductivity sensor 28 is read in step S402. , when the value is equal to or greater than a certain value (a predetermined threshold value), the process proceeds to the next step (step S403 ), and when the reading value of the conductivity sensor 28 at this time is a predetermined value or less, the subsequent main washing is skipped In the step of heater control in the process, the main washing process A is performed for a predetermined time without using the heater 29, and then the process proceeds to the main washing process B in S5.

In step S403, the heater 29 is turned on (ON), the current value is measured in the next step S404, and it is determined whether or not a current value equal to or greater than a predetermined value flows. At this stage, when the current value is equal to or less than the predetermined value, it is determined that the heater 29 is disconnected, the subsequent step of washing with warm water using the heater 29 is skipped, and the main washing step A is performed without using the heater 29 until the predetermined time. , and then transfer to the main washing step B of S5.

In step S404, when the current value when the sheathed heater is turned on is equal to or greater than the predetermined value, it is determined that the heater 29 is not disconnected and the connection terminal is not disconnected, but is normally connected, and the process proceeds to the next step S405, after the heater 29 is turned off (OFF), in step S406, the current value in the state where the heater 29 is turned off is measured, and it is determined whether the current value is lower than a predetermined value. At this time, when the current value is greater than or equal to the predetermined value, it is determined that the control circuit of the heater 29 is short-circuited, and the series of operations is terminated for safety, and the power supply of the main body is cut off.

Then, after the stirring operation in step S407, the value of the water level sensor 25 is read in step S408, and when the water level at this time is lower than the reset water level Tr, the water supply in step S409 is performed. Further, when 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 the above steps from steps S408 to S410, it is determined in step S411 whether or not a predetermined time has elapsed, and if it is less than the predetermined time, the process returns to the water level determination in step S408, and the operation is repeated until the predetermined time elapses, thereby washing clothes. In the above-mentioned steps, cleaning is performed at normal temperature in which the heater 29 is not turned on.

After that, after moving to the main washing step B ( S5 ), as shown in FIG. 8 , first, in step S501 , it is determined whether the read value of the water level sensor 25 is equal to or higher than the reset water level Tr, and if it is a water level equal to or higher than the reset water level Tr , and in the next step S502, the value of the conductivity sensor 28 is measured, and it is judged whether or not it is greater than or equal to the threshold value. When it is lower than the reset water level Tr, it transfers to step S503, and water supply is performed until the water level in the tub is equal to or higher than the reset water level Tr.

When the value of the conductivity sensor 28 is lower 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 malfunction of the water level sensor 25 or the like, and the operation is shifted to the normal state where the heater 29 is not used. washing process. When the reading value of the conductivity sensor 28 is equal to or greater than the threshold value, the heater 29 is completely submerged in the water, so it is determined that the heater 29 can be heated in a safe state, and the process proceeds to the next step S504.

That is, when the conductivity sensor 28 detects that the water level has risen to a predetermined height, in addition to the water level sensor 25 detecting the amount of water supplied to the drum 14 until the heater 29 is completely submerged in the water, control is performed so that the heater 29 The heating of the water in the drum 14 is started. By controlling in this way, even when there is some abnormality in the water level sensor 25 and the detected value is wrong, the measurement result of the conductivity sensor 28 can be seen, and the heater can be prevented from burning empty.

In step S504, the water temperature is read by the thermistor 29b, and when the temperature is equal to or lower than the set temperature TL, the heater 29 is turned on in step S505 to raise the water temperature. After that, in step S505, the water temperature is similarly measured by the thermistor 29b, and when the temperature is equal to or lower than the set temperature TH, the process proceeds to step S507, and stirring is continued for a predetermined time ta (for example, 3 minutes) with the heater turned on, After the predetermined time ta has elapsed, the process proceeds to step S508 to determine whether the operation time of the main washing step has ended.

When the operation time of the main washing process B has elapsed in the time of step S508, after turning off the heater 29 in step S509, it transfers to rinsing process S6 which is the next process.

When the detected temperature of the thermistor 29b is higher than the set temperature TH in step S506, the process proceeds to step S510, and after turning off the heater 29, after the stirring operation is continued for a predetermined time ta in step S511, it is determined in step S512 that the main Whether the operation time of the washing process B has ended. When it is determined that the operation time has ended, the process proceeds directly to the rinsing step S6, and when it is determined that the operation time has not ended, the process returns to step S501, the water level is detected by the water level sensor 25 and the conductivity sensor 28 again, and each step is repeated until the following The operation time of the main washing process B ends.

When the water temperature detected in step S504 is higher than the set temperature TL, the process proceeds to step S511 with the heater turned off, and the operation is performed as described above. At this time, the relationship between the set temperature TL and TH is set so that TL<TH, and the above-mentioned steps S501 to S512 are repeated, so that heating is performed by the heater 29 such as a jacket heater until it is stored in the tub When the water temperature of the water exceeds the set temperature TH, the heater 29 is turned off when the set temperature TH exceeds the set temperature TH, and then when the water temperature of the water in the tub decreases and becomes lower than the set temperature TL, the heater 29 is turned on. state and reheat. By repeating this operation until the main washing B operation time ends, the washing power of the laundry can be improved by washing the clothes with warm water.

In the rinsing step S6, the drum 14 is rotated at a high speed as an intermediate dehydration operation (not shown), and the washing liquid that has penetrated into the laundry is squeezed out by the centrifugal force of the rotation of the tub, and is discharged to the outside of the machine through the drainage path. By repeating the intermediate spin-drying and water supply operations for a set number of times, the detergent components and water contained in the clothes are scattered and removed.

Then, it transfers to a spin-drying|dehydration process S7, and rotates the drum 14 at a high speed, and it scatters and removes the water|moisture content in the laundry.

When the washing-drying operation is set, the drying step S8 is then executed to dry the laundry.

After the operation ends, a series of operation control ends.

By implementing 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 is also performed by the conductivity measurement unit (the conductivity sensor 28 ). When the reading value of the conductivity sensor 28 is less than a predetermined value, that is, when the water level is lower than a predetermined value, the main washing process is performed with the heater 29 turned off, so that abnormal heating can be prevented in the state where the heater is empty, that is, the The double anti-aircraft burning mechanism further improves the safety of the product.

In addition, in this embodiment, the drum-type washing and drying machine has been used for the description, but within the scope of the gist of the present invention, the so-called vertical type (pulsator) can also be used by changing the arrangement and control contents of the sensors and heaters. ) The present invention is applied to a washing and drying machine and a washing machine without a drying mechanism.

In this embodiment, the method of measuring the conductivity of the water in the tub using the conductivity sensor 28 has been described as a mechanism for detecting the water level, but a mechanism for detecting the water level by combining a buoy and a mechanical switch, for example, may be used.

Description of reference numerals

1 shell

3 doors

10 Water supply unit

14 rollers

15 barrels

16 barrel cover

18 Motor

25 Water level sensor

27 Controls

28 Conductivity sensor

29 heater

30 Heater cover.

Claims (3)

1. A washing machine, characterized by comprising:

an outer tub for storing water;

an inner tub rotatably supported in the outer tub and capable of receiving laundry;

a water supply part for supplying water to the outer barrel;

a water heating part heating water supplied into the tub;

a water level detecting part for detecting the water level in the outer barrel;

a conductivity measuring part for measuring the conductivity of the water in the outer barrel; and

a control part for controlling the water level detection part and the conductivity measurement part,

the control part controls the heating part to start heating based on a detection result of the water level detection part and a measurement result of the conductivity measurement part.

2. A washing machine as claimed in claim 1, wherein:

the conductivity measuring section is provided at a position higher than the water heating section.

3. A washing machine as claimed in claim 2, characterized in that:

the control unit performs the following control:

the water level detecting unit detects the amount of water supplied into the inner tub until the water heating unit is completely submerged in the water, and the conductivity measuring unit detects that the water level has risen to a predetermined level, and then the water heating unit starts heating the water in the inner tub.

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