Washing machine

Abstract

To provide a washing machine capable of ensuring washing power while reducing cloth damage.SOLUTION: A washing machine comprises: an outer tank 2 capable of storing a washing liquid inside; a rotary drum 1 that is rotatably supported in the outer tank 2 and stores the laundry; a blowing and foaming part 4 to generate bubbles containing 80% or more of air quantity per unit volume of bubbles; an agitator 5 to generate bubbles containing smaller air quantity per unit volume of bubbles compared to the blowing and foaming part 4; and a control device 10 to control the blowing and foaming part 4 and the agitator 5. The control device 10 rotates the agitator 5 while actuating the blowing and foaming part 4 when amount of the laundry is small.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a washing machine. [Background technology]

[0002] There are two types of washing machines: vertical type, in which the rotation axis of the inner tub is approximately perpendicular to the installation surface, and drum type, in which the rotation axis is horizontal or slightly inclined. For example, in a drum type washing machine, the washing liquid is pumped up and poured onto the laundry, so that the washing water containing dissolved detergent and the like is evenly soaked into the laundry. In this way, a drum type washing machine washes the laundry by a tumbling action or circulating the washing water with a circulation pump. During the washing process, the fabric is rubbed, causing damage to the fabric. Reducing the damage to the fabric reduces the cleaning power. Therefore, a washing method that ensures cleaning power while reducing damage to the fabric is required.

[0003] The structure of a drum type washing machine in Patent Document 1 includes a water tub for storing water, a drum rotatably mounted within the water tub with its rotation axis set either inclined or horizontal to the installation surface, a drum motor for driving the drum to rotate, an air bubble generating unit located below the drum in an area spanning the lowest part of the drum in the circumferential direction and capable of generating air bubbles in the water by supplying air to the water stored in the water tub, an air supply unit for supplying air to the air bubble generating unit, and a control device capable of controlling the operation of the drum motor and the air supply unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-97965 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the washing machine described in Patent Document 1, although the mechanism for generating air bubbles is described, there is no description regarding the state of the bubbles, and therefore there is a problem in that damage to fabrics cannot be reduced.

[0006] The present invention is devised to solve the above-mentioned problems in the conventional washing machine, and has an object to provide a washing machine capable of ensuring washing power while reducing damage to fabrics. [Means for solving the problem]

[0007] The present invention is characterized by comprising an outer tub capable of storing laundry liquid therein, an inner tub rotatably supported within the outer tub and in which laundry is stored, and a first foam generating means in which the amount of air contained in the foam per unit volume is 80% or more. Effect of the Invention

[0008] According to the present invention, a washing machine can be provided that can ensure cleaning power while reducing damage to fabrics. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a washing machine according to an embodiment of the present invention; [Diagram 2] 1 is a graph showing the relationship between the amount of air contained in foam and the detergent concentration in the foam. [Diagram 3] 11 is a graph showing damage to fabrics and cleaning power at various loads in the washing machine of the present embodiment compared to a conventional washing machine. [Figure 4] 11 is a graph showing damage to fabrics and cleaning power of the washing machine of the present embodiment at low load compared to a conventional washing machine. [Diagram 5] 4 is a flowchart showing the operation of the washing machine of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiment, and various modifications and application examples within the technical concept of the present invention are also included in its scope. Fig. 1 is a schematic diagram of a washing machine according to the present embodiment, in which the present invention is applied to a drum type washing machine. As shown in FIG. 1, the washing machine 100 is provided with an outer tub 2 inside a housing (not shown). A rotating drum 1 (inner tub) into which laundry is put is provided inside the outer tub 2. The rotation axis of the rotating drum 1 is inclined so that the front side is higher than the rear side. The rotation axis of the rotating drum 1 may be configured to be approximately horizontal. In this embodiment, a door (not shown) that opens and closes when putting laundry in or taking laundry out is provided on the front side of the housing (not shown).

[0011] A space is provided between the outer tub 2 and the rotating drum 1, allowing water to pass through between them. In other words, the side wall (circumferential wall) of the rotating drum 1 has many holes formed therein for use in dehydration and the like, allowing water and detergent solution (water containing detergent) to move from the rotating drum 1 toward the outer tub 2 and from the outer tub 2 into the rotating drum 1.

[0012] The washing machine 100 also includes a drum motor 6 that rotates the rotating drum 1. The drum motor 6 rotates the rotating drum 1 in the forward and reverse directions during the washing and rinsing processes, and is controlled to rotate at high speed during the spin-drying process. During the washing process, the laundry is lifted to the top of the rotating drum 1, and then beaten by a tumbling action that causes it to fall to the bottom by gravity.

[0013] The washing machine 100 is also provided with a circulation pump 7 for pumping water and detergent liquid accumulated in the bottom 2a of the outer tub 2 up to the top of the outer tub 2 and spraying the water into the rotating drum 1. A pipe 9a is connected to the suction side of the circulation pump 7, and a pipe 9b is connected to the discharge side. An end of the pipe 9a is connected to the bottom 2a of the outer tub 2. An end of the pipe 9b is connected to the top of the outer tub 2. A sprinkling nozzle 9c for spraying water and detergent liquid into the rotating drum 1 is provided at the tip of the pipe 9b.

[0014] Moreover, the washing machine 100 includes an air-blowing foaming section 4 (first foam generating means), a second foam generating means, and a control device 10 (control section).

[0015] The air blowing foaming section 4 is configured with an air blower 3 and an air duct 8. One end of the air duct 8 is connected to the air blower 3, and the other end is connected to the lower part of the outer tub 2. A discharge nozzle 8a capable of discharging air bubbles is formed at the tip of the air duct 8. The shape of the nozzle is not particularly limited as long as it can form bubbles with a high air content per unit volume. Air is blown from the air blower 3 into the laundry liquid (detergent liquid) accumulated at the lower part of the outer tub 2, causing bubbles to form.

[0016] The air content is defined by the following formula and indicates the proportion of air contained in the foam. Air content (%) = [1-(original liquid volume / foam volume)] x 100

[0017] At this time, the foam generated by the foaming in the air blowing section 4 contains a large amount of air per unit volume (high air content). Foam with a high air content reduces friction and is therefore effective in reducing damage to fabrics. Figure 2 is a graph showing the relationship between the amount of air contained in the foam and the detergent concentration in the foam. As shown in Figure 2, it was found that a higher air content leads to a higher detergent concentration. A spectrophotometer was used to confirm the detergent concentration, but titration or liquid chromatography can also be used. In particular, it was confirmed that the detergent concentration becomes high when the air content is 80% or more. By increasing the detergent concentration in this way, the cleaning power of the detergent can be improved. Therefore, by washing with bubbles generated by the air sent from the blower 3, the cleaning power can be improved. In addition, the surfactant concentration in the foam during actual washing was about 2 to 3 times that in the detergent solution.

[0018] The second foam generating means can generate foam with less air content per unit volume (lower air content) than the first foam generating means (air blowing foaming section 4). Foam with a lower air content reduces friction and drop impact, and is therefore more effective in reducing damage to fabrics than foam with a higher air content. The second foam generating means can be configured by rotating the stirrer 5. The stirrer 5 is provided at the bottom of the outer tub 2, and its rotation is controlled. In this way, foam with a lower air content can be generated by stirring the detergent solution with the stirrer 5. The stirrer 5 can be provided at a position across the water surface to generate foam more efficiently.

[0019] In this embodiment, the stirrer 5 has been described as an example of the second foam generating means, but other methods may be used. For example, foam with a low air content can be generated by stirring the surface of the detergent liquid with the rotation of the rotating drum 1. In addition, foam with a low air content can also be generated by driving the circulation pump 7 to cause a water flow to hit the liquid surface in the rotating drum 1 or the laundry.

[0020] Furthermore, when the amount of clothes is small (when the laundry load is small), the clothes are more likely to hit the wall of the rotating drum 1 directly, and the foam generated by the air-blow foaming section 4 (first foam generating means) has a thinner film thickness and is more likely to disappear than when the amount of clothes is large. Therefore, when the amount of clothes is small, if the execution of the air-blow foaming section 4 (first foam generating means) is stopped while the rotating drum 1 is rotating, and foam with a high air content is generated by the air-blow foaming section 4 (first foam generating means) when the rotating drum 1 is stopped rotating, foam with a high air content can be more effectively introduced into the rotating drum 1.

[0021] Furthermore, when there is a large amount of laundry (when the laundry load is large), the laundry hits the fabric, and the foam generated by the air-blow foaming unit 4 (first foam generating means) does not disappear easily. Therefore, when there is a large amount of laundry, it is not necessary to stop the operation of the air-blow foaming unit 4 (first foam generating means) even when the rotating drum 1 is rotating.

[0022] The second foam generating means is preferably used according to the laundry load, since using it when there are few clothes produces more foam with a low air content, which is more effective at reducing damage to fabrics than foam with a high air content.

[0023] The control device 10 includes electronic circuits such as a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and various interfaces. The control device 10 reads out a program stored in the ROM and loads it into the RAM, and the CPU executes various processes. The control device 10 also controls the ON / OFF of the blower 3, the drum motor 6, and the circulation pump 7.

[0024] 3 is a graph showing the damage to fabric and the cleaning power of the washing machine of this embodiment at each load compared to the conventional washing machine. The test results are for the case where only the air blowing foaming section 4, which can generate foam with a high air content, is operated. However, in this test, the rotating drum 1 always rotates, so foam with a low air content is also generated.

[0025] As shown in the white bar graph in FIG. 3, the cleaning power at each load was equal to or greater than the conventional one (100%). Also, as shown in the black bar graph in FIG. 3, the damage to the fabric when the load (cloth amount) was 4 kg was 90% of the conventional one, which was reduced by 10%. Also, the damage to the fabric when the load (cloth amount) was 7 kg was 70% of the conventional one, which was reduced by 30%. Also, the damage to the fabric when the load (cloth amount) was 9 kg was 70% of the conventional one, which was reduced by 30%. In this way, in this embodiment, it is possible to realize a washing machine 100 equipped with a cleaning method that can reduce damage to the fabric while maintaining the cleaning power.

[0026] FIG. 4 is a graph showing damage to fabric and cleaning power of the washing machine of this embodiment at low load compared to the conventional one. The test results shown here are the results when the air blowing foaming unit 4 capable of generating foam with a high air content and the circulation pump 7 capable of generating foam with a low air content are used in combination. When the load (cloth amount) is 2 kg, the cleaning power is equal to or greater than 110% compared to the conventional one, and the damage to fabric is 80%, a reduction of 20%. Thus, in this embodiment, by using the second foam generating means even in the low load range, it is possible to realize a washing machine 100 equipped with a cleaning method that can reduce damage to fabric while maintaining cleaning power.

[0027] FIG. 5 is a flowchart showing the operation of the washing machine of the present embodiment. As shown in Fig. 5, the control device 10 executes laundry amount sensing in step S10. This laundry amount sensing is a process of detecting the weight of the laundry (laundry load) put into the washing machine 100. Specifically, the drum motor 6 is driven to rotate the rotating drum 1, and the laundry amount is calculated based on the rotation speed and motor current value of the drum motor 6. For example, as the weight (load) of the laundry increases, the load for rotating the rotating drum 1 increases and more motor current is required to flow through the motor. Therefore, the laundry weight can be calculated from the motor current and rotation speed of the drum motor 6.

[0028] In step S20, the control device 10 determines whether the weight (load) of the laundry is less than a predetermined value. The predetermined value is set to, for example, 2.1 kg. If the control device 10 determines that the weight is less than the predetermined value (S20, Yes), the process proceeds to step S30, where it decides to execute the first foam generation means (air-blowing section 4) and the second foam generation means (rotation of stirrer 5). If the control device 10 determines that the weight is equal to or greater than the predetermined value (S20, No), the process proceeds to step S40, where it decides to execute the first foam generation means (air-blowing).

[0029] In step S50, the control device 10 executes the water supply 1 step (first water supply). That is, the control device 10 opens the water supply solenoid valve (not shown) to start supplying water into the outer tub 2, raising the water level in the outer tub 2, and drives the drum motor 6 to rotate the rotating drum 1 in the forward and reverse directions at a predetermined rotation speed, replacing the laundry. The control device 10 also controls the circulation pump 7 to rotate at a predetermined rotation speed, and sprays the detergent liquid sucked from the outer tub 2 in a shower-like manner from the watering nozzle 9c (see FIG. 1) provided on the upper part of the outer tub 2, so that the detergent liquid soaks into the clothes. Then, when the control device 10 determines that the predetermined water level has been reached by the water level sensor (not shown), it closes the water supply solenoid valve (not shown) to stop the water supply.

[0030] In step S60, the control device 10 executes the high-concentration washing process. That is, the control device 10 controls the drum motor 6 to rotate the rotating drum 1 in the forward and reverse directions at a predetermined rotation speed, and replaces the clothes. The control device 10 also controls the circulation pump 7 to rotate at a predetermined rotation speed, and the detergent liquid sucked from the outer tub 2 is sprayed in a shower from the watering nozzle 9c (see FIG. 1) provided on the upper part of the outer tub 2, so that the detergent liquid soaks into the clothes. Then, the control device 10 executes the high-concentration washing process until a predetermined time has elapsed. In this way, the high-concentration washing process is a process of waiting for water to soak into the clothes (a process of compensating for the time difference until the clothes are hydrated). By spreading a small amount of water over the entire laundry in advance and washing with a high-concentration detergent liquid, there is an effect of improving the washing power, but in the present invention, since the washing power can be improved by washing with foam having a high air content, the steps S50 and S60 may be omitted.

[0031] In step S70, the control device 10 executes the second water supply process (second water supply). That is, the control device 10 opens the water supply solenoid valve (not shown) to start supplying water to the outer tub 2. Then, when the control device 10 determines that the water level has reached a predetermined water level using the water level sensor, it closes the water supply solenoid valve (not shown) to stop the water supply. In this second water supply process, the water level may drop depending on the condition of the clothes. In this way, by executing the second water supply process, it is confirmed whether the water level desired in the first water supply process has been reached, and if the desired water level has not been reached, water is supplied up to the desired water level. Note that in the second water supply process, water supply may be performed while rotating the rotating drum 1.

[0032] In step S80, the control device 10 executes the foam washing process. That is, when the load is less than a predetermined value (S20, Yes), the control device 10 controls (ON) the blower 3 to start blowing air into the outer tub 2. As a result, the detergent liquid accumulated in the bottom 2a of the outer tub 2 becomes foam with a high air content by the air from the blower 3. The foam generated in this way passes through the holes of the rotating drum 1 and contacts the clothes in the rotating drum 1. By generating and contacting the laundry in the rotating drum 1 in this way, the cleaning power can be increased. This is because the detergent concentration is high at the interface (plateau boundary) where the bubbles are in close contact with each other, and when the bubbles burst, a high concentration of detergent liquid is given to the laundry, and a mechanical force acts on the laundry due to the impact when the bubbles break (when the bubbles burst), thereby improving the cleaning effect.

[0033] Furthermore, when the weight (load) of the laundry is less than a predetermined value (S20, Yes), the control device 10 rotates the agitator 5 to generate foam with a low air content. The control device 10 also rotates the rotating drum 1 to generate foam with a low air content. The control device 10 also drives the circulation pump 7 to generate foam with a low air content. The foam generated by the rotation of the agitator 5 adheres to the clothes through the spin-drying holes formed in the rotating drum 1. The clothes are also washed while the foam adheres to the surface of the clothes by rotating the rotating drum 1 in the forward and reverse directions to turn the clothes upside down. The circulation pump 7 is driven to drop the detergent liquid onto the liquid surface to generate foam, and the foam adheres to the surface of the clothes to wash them. In the present embodiment, the case where the rotation of the agitator 5 and the drive of the circulation pump 7 are used in combination have been described as an example, but either the rotation of the agitator 5 or the drive of the circulation pump 7 may be used.

[0034] In this way, when the load is low (when the load is less than a predetermined value) (S20, Yes), the damage to the fabric caused by friction between the clothes is small, but the damage to the fabric when the clothes fall is large. However, by using foam with a low air content in combination, it is possible to absorb the impact when the clothes fall and reduce the damage to the fabric.

[0035] In addition, when the load is high (when the load is equal to or greater than a predetermined value) (S20, No), the control device 10 determines that damage to the fabric when the clothes fall is small, but damage to the fabric due to friction between the clothes is large; however, by using foam with a high air content, friction between the clothes can be reduced, making it possible to reduce damage to the fabric.

[0036] In step S90, the control device 10 executes the rinsing process. That is, the control device 10 opens the drain valve (not shown) to drain the water in the outer tub 2, and when the water level sensor detects that the water level in the outer tub 2 has fallen below a predetermined water level, the control device 10 rotates the rotating drum 1 at high speed with the drain valve (not shown) open to spin-dry the wash water contained in the clothes. Then, when the control device 10 determines that a predetermined time has elapsed, it ends the spin-drying, closes the drain valve, and opens the water supply solenoid valve to supply water to the outer tub 2. Then, when the control device 10 detects that water has been supplied up to the predetermined water level by the water level sensor, it stops the water supply, controls the drum motor 6 to rotate the rotating drum 1 in the forward and reverse directions, and performs rinsing while replacing the clothes.

[0037] In step S100, the control device 10 executes a spin-drying process. That is, the control device 10 opens a drain valve (not shown) to drain the water in the outer tub 2, and when the water level sensor detects that the water level in the outer tub 2 has fallen below a predetermined water level, the control device 10 rotates the rotating drum 1 at high speed with the drain valve open to spin-dry the wash water contained in the clothes. Then, when the control device 10 determines that a predetermined time has elapsed, it ends the spin-drying process.

[0038] As described above, the washing machine 100 of this embodiment includes the outer tub 2 capable of storing detergent liquid therein, the rotary drum 1 (inner tub) rotatably supported in the outer tub 2 and accommodating laundry, and the air blowing foaming unit 4 as a first foam generating means having an air content of 80% or more per unit volume. This ensures cleaning power while reducing damage to fabrics.

[0039] This embodiment also includes a second foam generating means (agitator 5, circulation pump 7) that generates foam containing less air per unit volume than the air blowing foaming section 4 (first foam generating means), and a control device 10 (control unit) that controls the first foam generating means and the second foam generating means. The control device 10 determines whether or not to execute the second foam generating means depending on the laundry (clothes) load (cloth amount). In this way, by executing the second foam generating means when the amount of clothes is small (when the load is small), damage to the clothes can be reduced.

[0040] In addition, in this embodiment, when the laundry load is less than a predetermined value, the control device 10 executes the second foam generating means (agitator 5, circulation pump 7) while executing the air blowing foaming unit 4 (first foam generating means), and when the laundry load is equal to or greater than the predetermined value, the control device 10 executes the air blowing foaming unit 4 (first foam generating means) while not executing the second foam generating means (agitator 5, circulation pump 7) other than the rotation of the rotating drum 1 (other than the rotation of the inner tub). According to this, when the amount of clothes is small (when the load is less than a predetermined value), the second foam generating means is executed, thereby reducing damage to the clothes. Also, when the amount of clothes is large (when the load is equal to or greater than a predetermined value), the second foam generating means other than the rotation of the rotating drum 1 is not executed, thereby reducing damage to the clothes and ensuring the cleaning power.

[0041] Furthermore, in this embodiment, when the laundry load is less than a predetermined value, the control device 10 stops the execution of the air-blow foaming unit 4 (first foam generating means) when the rotating drum 1 is rotating, and executes the air-blow foaming unit 4 (first foam generating means) when the rotating drum 1 is stopped rotating. When there is a small amount of laundry, the laundry directly hits the rotating drum 1, so the foam generated by the first foam generating means is likely to disappear, hindering the effect of reducing damage to the fabric. Therefore, by stopping the execution of the first foam generating means when the rotating drum 1 is rotating, and executing the first foam generating means when the rotating drum 1 is stopped rotating, damage to the fabric can be effectively reduced.

[0042] In this embodiment, the second foam generating means is configured to include an agitator 5 that rotates and agitates in the detergent liquid. This makes it possible to actively generate foam with a low air content, and by executing this when the amount of laundry is small (when the load is less than a predetermined value), damage to the laundry can be effectively reduced.

[0043] Furthermore, in this embodiment, the surfactant concentration in the foam during washing is set to about 2 to 3 times (or more than 2 times) the surfactant concentration in the detergent liquid accumulated in the bottom 2a of the outer tub 2, i.e., the air content is set to about 90% to 95%, thereby obtaining both a high concentration and the effect of reducing damage to fabrics caused by the foam, thereby ensuring cleaning power while reducing damage to fabrics.

[0044] In the present invention, a drum type washing machine without a drying function has been described as an example, but the present invention may be applied to a drum type washer / dryer with a drying function. In this case, the blower used for the drying function can be used as the blowing foaming section (first foam generating means).

[0045] In addition, in the present invention, an example has been described in which the second foam generating means other than the rotation of the rotating drum 1 includes foam generation by rotating the stirrer 5 and foam generation by driving the circulation pump 7, but a configuration in which only one of these is included may also be used. [Explanation of symbols]

[0046] 1 Rotating drum (inner tank) 2 Outer tank 2a Bottom of outer tank 3. Blower 4. Air blowing foaming section (first foam generating means) 5. Stirrer (second foam generating means) 6 Drum motor 7 Circulation pump (second foam generating means) 8 Air pipe 8a Discharge nozzle 9a,9b Piping 9c Watering nozzle 10 Control device (control unit) 100 Washing Machine

Claims

1. An outer tub capable of storing washing liquid therein; an inner tub that is rotatably supported within the outer tub and that accommodates laundry; A washing machine comprising: a first foam generating means having an air amount contained in foam per unit volume of 80% or more.

2. The washing machine according to claim 1, a second foam generating means for generating foam having a lower amount of air per unit volume than the first foam generating means; A control unit that controls the first foam generating means and the second foam generating means, The control unit determines whether or not the second foam generating means is activated depending on a load of laundry.

3. The washing machine according to claim 2, The control unit executes the first foam generating means while executing the second foam generating means when the laundry load is less than a predetermined value, and executes the first foam generating means while not executing the second foam generating means other than rotating the inner tub when the laundry load is equal to or greater than the predetermined value.

4. The washing machine according to claim 2, The control unit, when the laundry load is less than a predetermined value, stops execution of the first foam generating means when the inner tub is rotating, and executes the first foam generating means when the inner tub has stopped rotating.

5. The washing machine according to claim 2, The washing machine, wherein the second foam generating means is configured to include an agitator that rotates in the washing liquid to agitate it.

6. The washing machine according to claim 1, The washing machine is characterized in that the concentration of a surfactant contained in the detergent liquid forming foam is more than twice as high as that of the detergent liquid pooled at the bottom of the outer tub.

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