Dirt removal device

Abstract

To improve dirt removing efficiency.SOLUTION: A vacuum cleaner 10 includes: a pair of electrodes 21a, 21b whose tip end parts are provided so as to be disposed in the vicinity of a floor surface 1 to be cleaned and in which a distance between the tip end parts is 5 mm or more and 10 mm or less; and a voltage supply part 22 which supplies a pulse voltage of 11 kV or more and 49 kV or less between the electrodes 21a, 21b for generating a surface discharge along the floor surface 1 to be cleaned between the electrodes 21a, 21b. The vacuum cleaner removes dirt containing synthetic resin or synthetic rubber adhering to the floor surface 1 to be cleaned.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a stain removal device using plasma. [Background technology]

[0002] Among floor stains, heel marks, which are marks left by shoes on the floor, are particularly difficult to remove because the frictional heat between the shoe and the floor causes the components of the shoe to become integrated with the components of the floor. The main components of heel marks are polyurethane and nylon, and currently, the stains are removed mechanically by scraping the floor surface with a vacuum cleaner called a polisher, or chemically by using an alkaline detergent. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4188801 Summary of the Invention [Problem to be solved by the invention]

[0004] When using a polisher, there is a problem that the floor surface is significantly damaged. In addition, when using an alkaline detergent, there is a problem that the used detergent needs to be collected. Although a technology for purifying the surface to be cleaned by using active species generated by a plasma generator has been proposed (for example, see Patent Document 1), there is a problem in terms of the time required to remove dirt.

[0005] The present disclosure provides techniques to improve the efficiency of soil removal. [Means for solving the problem]

[0006] The dirt removal device disclosed herein comprises a pair of electrodes whose tip portions are positioned near the surface of the object to be cleaned with a distance between them of 5 mm or more and 10 mm or less, and a voltage supply unit that supplies a pulse voltage of 11 kV or more and 49 kV or less between the electrodes to generate a creeping discharge along the surface of the object to be cleaned between the electrodes, and removes dirt including synthetic resin or synthetic rubber adhering to the surface of the object to be cleaned. Effect of the Invention

[0007] According to the present disclosure, the efficiency of dirt removal can be improved. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a configuration diagram of a vacuum cleaner according to an embodiment of the present disclosure. [Figure 2A] Diagram showing examples of dirt on floor surfaces [Figure 2B] FIG. 2B shows the state of the dirt shown in FIG. 2A after irradiating plasma for 60 seconds using the vacuum cleaner according to the first embodiment. [Figure 2C] SEM image of floor surface after plasma irradiation [Diagram 3] FIG. 1 is a diagram showing an example of the waveform of an applied pulse voltage. [Figure 4] A diagram showing the relationship between the voltage applied between the electrodes and the number of spark discharges. [Diagram 5] FIG. 1 is a diagram showing the relationship between the voltage applied between the electrodes and the discharge current. [Figure 6] Partial histogram of Fig. 5 [Figure 7] A diagram showing the relationship between the voltage applied between the electrodes and the number of spark discharges. [Figure 8] FIG. 1 is a diagram showing the relationship between the voltage applied between the electrodes and the discharge current. [Figure 9] A diagram showing the relationship between the voltage applied between the electrodes and the number of spark discharges. [Figure 10] FIG. 1 is a diagram showing the relationship between the voltage applied between the electrodes and the discharge current. [Figure 11] A diagram showing the relationship between the voltage applied between the electrodes and the number of spark discharges. [Figure 12] FIG. 1 is a diagram showing the relationship between the voltage applied between the electrodes and the discharge current. [Figure 13] A diagram showing the relationship between the voltage applied between the electrodes and the number of spark discharges. [Figure 14] FIG. 1 is a diagram showing the relationship between the voltage applied between the electrodes and the discharge current. [Figure 15A] A diagram showing the evaluation results under condition (1). [Figure 15B] A diagram showing the evaluation results under condition (2). [Figure 15C] A diagram showing the evaluation results under condition (3). [Figure 15D] A diagram showing the evaluation results under condition (4). [Figure 16A] Graph showing measurement results under condition (1) [Figure 16B] Graph showing measurement results under condition (2) [Figure 16C] Graph showing the measurement results under condition (3) [Figure 16D] Graph showing the measurement results under condition (5) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiments will be described in detail with reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed description of already well-known matters or duplicate description of substantially the same configuration may be omitted.

[0010] It should be noted that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0011] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 16D.

[0012] [1-1. Configuration] 1 shows the configuration of a vacuum cleaner 10 according to an embodiment of the dirt removal device of the present disclosure. The vacuum cleaner 10 includes a suction unit 11, a wiping unit 12, a plasma generating unit 20, and a control unit 30.

[0013] The plasma generating unit 20 generates atmospheric pressure plasma and irradiates the cleaning target, such as a floor surface 1, with the plasma in order to remove dirt 2, such as heel marks, adhering to the cleaning target. The plasma generating unit 20 includes a pair of electrodes 21a, 21b, a power source 22, and a gas supply unit 23.

[0014] The pair of electrodes 21a, 21b are configured so that their tip portions can be positioned near the floor surface 1 to generate a creeping discharge along the floor surface 1 to be cleaned. The power source 22 applies a high voltage to the electrodes 21a, 21b to generate a creeping discharge between the electrodes 21a, 21b. The gas supply unit 23 supplies gas for generating plasma between the electrodes 21a, 21b. Since air is usually present near the floor surface 1, if dirt can be removed without supplying gas from the gas supply unit 23, the vacuum cleaner 10 does not need to include the gas supply unit 23.

[0015] The control unit 30 controls each component of the vacuum cleaner 10. The control unit 30 arranges the tip portions of the electrodes 21a and 21b at a predetermined height from the floor surface 1 at a predetermined interval. The control unit 30 controls the power source 22 to apply a high voltage between the electrodes 21a and 21b, and controls the gas supply unit 23 to supply a gas to be put into a plasma state between the electrodes 21a and 21b. When the voltage between the electrodes 21a and 21b exceeds a certain limit, a discharge occurs between the electrodes 21a and 21b. This discharge causes the gas present between the electrodes 21a and 21b to become a plasma state, and the gas is irradiated onto the floor surface 1.

[0016] Dirt on shoe soles and other surfaces is mainly composed of synthetic resins such as polyurethane and nylon. Dirt on the wheels of carry-on bags and other surfaces is mainly composed of synthetic rubber containing ethylene, propylene, butadiene, and other compounds. By irradiating plasma onto these stains 2, it is possible to break the covalent bonds of the molecules that make up the stain 2, or to break the chemical bonds between the molecules that make up the stain 2 and the molecules that make up the floor surface, thereby peeling off the stain 2 from the floor surface or vaporizing it. This allows the stain 2 to be removed efficiently and in a short time without damaging the floor surface 1. The same applies to stains composed of other organic substances, etc.

[0017] The suction unit 11 sucks up the dirt 2 peeled off from the floor surface 1 by the plasma. The wiping unit 12 wipes off the dirt 2 decomposed by the plasma. This makes it possible to remove the dirt 2 from the floor surface 1. If the dirt 2 decomposed by the plasma is oxidized in the air and vaporized as carbon dioxide, carbon monoxide, water vapor, or the like, the vacuum cleaner 10 does not need to include the suction unit 11 and the wiping unit 12. In addition, the vacuum cleaner 10 may only have the function of irradiating the plasma to peel off the dirt 2 from the floor surface 1, and the function of sucking and wiping off the dirt 2 may be performed by another vacuum cleaner or the like. In this case, the vacuum cleaner 10 does not need to include the suction unit 11 and the wiping unit 12.

[0018] The plasma generating unit 20 may generate a spark discharge between the electrode 21a and the electrode 21b. In this case, the power source 22 may generate a spark discharge multiple times in a short time by applying a pulse high voltage between the electrodes. This can shorten the time required to remove the dirt 2, and improve the cleaning efficiency.

[0019] The plasma generating unit 20 may generate a corona discharge between the electrode 21a and the electrode 21b. In this case, at least the tip portion of the electrode 21a and the electrode 21b may be formed in a needle shape. In this case, the time required to remove the dirt 2 can be shortened, and the cleaning efficiency can be improved.

[0020] FIG. 2A shows an example of dirt 2 attached to floor surface 1. FIG. 2B shows the dirt 2 shown in FIG. 2A after irradiating plasma for 60 seconds by vacuum cleaner 10 according to embodiment 1. The dirt 2 between electrode 21a and electrode 21b has been removed. It was confirmed that when argon gas was supplied from gas supply unit 23, dirt 2 was removed by irradiating plasma for 10 seconds. In addition, when the temperature of the plasma on floor surface 1 was measured with a label-type thermometer, the temperature of floor surface 1 was about 50°C. Therefore, it was confirmed that dirt 2 was not removed by the action of heat. FIG. 2C shows an SEM image of floor surface 1 after plasma irradiation. It was confirmed that floor surface 1 was not scratched by plasma irradiation.

[0021] [1-2. Operation] The operation and function of the vacuum cleaner 10 configured as above will now be described.

[0022] When the user instructs the vacuum cleaner 10 to start cleaning, the control unit 30 positions the tip portions of the electrodes 21a and 21b at a predetermined height from the floor surface 1 at a predetermined interval. The control unit 30 controls the power source 22 to apply a high voltage between the electrodes 21a and 21b, and controls the gas supply unit 23 to supply a gas to be put into a plasma state between the electrodes 21a and 21b. When the voltage between the electrodes 21a and 21b exceeds a certain limit, a discharge occurs between the electrodes 21a and 21b. This discharge causes the gas present between the electrodes 21a and 21b to become a plasma state, and the gas is irradiated onto the floor surface 1. When the user instructs the vacuum cleaner 10 to end cleaning, or when plasma has been irradiated for a predetermined time, the control unit 30 stops the application of voltage and the supply of gas.

[0023] [Example] The present inventors conducted an experiment to investigate the relationship between plasma generation conditions and dirt removal performance.

[0024] Needle-shaped electrodes 21a and 21b were placed on either side of dirt 2 adhering to floor surface 1 so as to sandwich the dirt 2, and a pulse high voltage was applied between the electrodes from power source 22. Figure 3 shows an example of the waveform of the applied pulse voltage. The peak-to-peak voltage is represented by Vpp, the pulse width by Pw, and the period by T. The duty ratio is represented by Pw / T.

[0025] 4 shows the relationship between the voltage applied between the electrodes and the number of spark discharges when the inter-electrode distance is 10 mm, the duty ratio is 10%, and no gas is supplied from the gas supply unit 23. The higher the applied voltage, the more the number of discharges increases.

[0026] Fig. 5 shows the relationship between the voltage applied between the electrodes and the discharge current when the electrode distance is 10 mm, the duty ratio is 10%, and no gas is supplied from the gas supply unit 23. There is a large variation, but this is because there are abnormal values ​​as shown in Fig. 6. In general, the higher the applied voltage, the smaller the current value.

[0027] 7 shows the relationship between the voltage applied between the electrodes and the number of spark discharges when the inter-electrode distance is 5 mm, the duty ratio is 10%, and no gas is supplied from the gas supply unit 23. When the applied voltage is 42.6 kVpp or less, the number of discharges increases as the applied voltage is increased, but when the applied voltage is 42.6 kVpp or more, the number of discharges decreases as the applied voltage is increased.

[0028] 8 shows the relationship between the voltage applied between the electrodes and the discharge current when the electrode distance is 5 mm, the duty ratio is 10%, and no gas is supplied from the gas supply unit 23. There is a large variation, but this is also due to the presence of abnormal values. Regardless of the applied voltage, the current value is about 0 to 10 A.

[0029] 9 shows the relationship between the voltage applied between the electrodes and the number of spark discharges when the inter-electrode distance is 10 mm, the duty ratio is 10%, and air is supplied at 20 L / min from the gas supply unit 23. In general, the higher the applied voltage, the more the number of discharges increases.

[0030] 10 shows the relationship between the voltage applied between the electrodes and the discharge current when the inter-electrode distance is 10 mm, the duty ratio is 10%, and air is supplied at 20 L / min from the gas supply unit 23. When the applied voltage is 38 kVpp or less, the current value increases as the applied voltage is increased, but when the applied voltage is 38 kVpp or more, the current value decreases as the applied voltage is increased.

[0031] Fig. 11 shows the relationship between the voltage applied between the electrodes and the number of spark discharges when the inter-electrode distance is 10 mm, the duty ratio is 20%, and air is not supplied from the gas supply unit 23. Fig. 12 shows the relationship between the voltage applied between the electrodes and the discharge current when the inter-electrode distance is 10 mm, the duty ratio is 20%, and air is not supplied from the gas supply unit 23. The number of spark discharges is greater than when the duty ratio is 10%. When the applied voltage was higher than 40 kVpp, the floor surface burned, so measurements were not made at voltages higher than this.

[0032] Fig. 13 shows the relationship between the voltage applied between the electrodes and the number of spark discharges when the inter-electrode distance is 10 mm, the duty ratio is 30%, and air is not supplied from the gas supply unit 23. Fig. 14 shows the relationship between the voltage applied between the electrodes and the discharge current when the inter-electrode distance is 10 mm, the duty ratio is 30%, and air is not supplied from the gas supply unit 23. The number of spark discharges is greater than when the duty ratio is 10%. When the applied voltage was higher than 40 kVpp, the floor surface burned, so measurements were not made at voltages higher than this.

[0033] The heel mark removal performance was evaluated under the following conditions. The heel mark was irradiated with plasma for 60 seconds, and the change rate of pixel value was evaluated by analyzing the images of the heel mark before and after plasma irradiation. The greater the change rate, the more the dirt was removed. (1) Distance between electrodes: 10 mm, duty ratio: 10%, air supply: none (2) Distance between electrodes: 5 mm, duty ratio: 10%, air supply: none (3) Distance between electrodes: 10 mm, duty ratio: 20%, air supply: none (4) Distance between electrodes: 10 mm, duty ratio: 10%, air supply: 20 L / min

[0034] 15A to 15D show the evaluation results under conditions (1) to (4), respectively. Under all conditions, generally, more dirt was removed at the applied voltage that increased the number of discharges. It is believed that the greater the number of discharges, the more opportunities there are to decompose the molecules that make up the dirt, and therefore the efficiency of removing dirt can be improved. Also, under condition (4), in which air was supplied from gas supply unit 23, the greatest amount of dirt was removed. Supplying gas increases the amount of plasma, and therefore it is believed that the efficiency of removing dirt can be improved.

[0035] Under the conditions below, the maximum temperature within a 1 cm diameter area at a distance of approximately 20 cm from the floor surface was measured using a non-contact radiation thermometer. (1) Distance between electrodes: 10 mm, duty ratio: 10%, air supply: none (2) Distance between electrodes: 5 mm, duty ratio: 10%, air supply: none (3) Distance between electrodes: 10 mm, duty ratio: 20%, air supply: none (5) Distance between electrodes: 10 mm, duty ratio: 30%, air supply: none

[0036] 16A to 16D show the measurement results under conditions (1) to (3) and (5), respectively. Under conditions (1) and (2), the temperature of the floor surface did not rise even when a discharge occurred. It was confirmed that the dirt was not removed by the effect of temperature, but by the irradiation of plasma. Under conditions (3) and (4), if the voltage was too high, the temperature of the floor surface would rise and the floor would be burned. Even in this case, the floor surface can be cooled by supplying gas from gas supply unit 23.

[0037] [1-3. Effects, etc.] As described above, in this embodiment, the vacuum cleaner 10 includes a pair of electrodes 21a, 21b whose tip portions are arranged so as to be positioned near the floor surface 1 to be cleaned, and a power source 22 that supplies a voltage between the electrodes 21a, 21b to generate a creeping discharge between the electrodes 21a, 21b along the floor surface 1 to be cleaned. This can reduce the time required to remove dirt and improve the efficiency of cleaning.

[0038] In the present embodiment, the vacuum cleaner 10 further includes a gas supply unit 23 that supplies gas between the electrodes 21a and 21b. This can reduce the time required to remove dirt, thereby improving the efficiency of cleaning.

[0039] In the present embodiment, the vacuum cleaner 10 generates a spark discharge or a corona discharge between the electrodes 21a and 21b, which can shorten the time required to remove dirt and improve the cleaning efficiency.

[0040] In the present embodiment, the tips of the electrodes 21a and 21b have a needle-like shape, which can improve the cleaning efficiency.

[0041] (Other embodiments) As described above, the first embodiment has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. In addition, it is also possible to combine the components described in the first embodiment to create new embodiments.

[0042] Therefore, other embodiments will be exemplified below.

[0043] In the first embodiment, the technique for removing heel marks has been mainly described, but the stain removal device of the present disclosure can be used to remove any type of stain.

[0044] It should be noted that the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, substitutions, additions, omissions, and the like can be made within the scope of the claims or their equivalents. [Industrial Applicability]

[0045] The present disclosure is applicable to stain removal devices. [Explanation of symbols]

[0046] 1. Floor 10 Vacuum cleaner 11 Suction part 12 Wiping section 20 Plasma generating section 21a electrode 21b Electrode 22 Power supply 23 Gas supply section 30 Control section

Claims

1. A pair of electrodes, each having a tip portion that can be positioned near a surface to be cleaned, the tip portions of which are spaced apart by a distance of 5 mm to 10 mm; A voltage supply unit that supplies a pulse voltage of 11 kV to 49 kV between the electrodes to generate a creeping discharge along the surface of the cleaning target between the electrodes; Equipped with A stain removal device for removing stains containing synthetic resin or synthetic rubber adhering to the surface of the object to be cleaned.

2. The gas supply unit further includes a gas supply unit that supplies a gas between the electrodes. The stain removal device according to claim 1 .

3. A spark discharge or a corona discharge is generated between the electrodes. A stain removing device according to claim 1 or 2.

4. The voltage supply unit supplies a pulse voltage having a duty ratio of 30% or less. A stain removing device according to any one of claims 1 to 3.

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