Dishwasher

Abstract

To provide a dishwasher capable of achieving reliable cleaning using hydrophobic adsorption properties of fine bubbles and achieving size reduction.SOLUTION: A dishwasher according to the present invention includes a structure in which pre-wash cleaning means generates fine bubbles in immersion water within a pre-wash tank, and can effectively wash a washing object since contaminants including oil in the immersion water are more easily adsorbed by the fine bubbles by utilizing the action of the hydrophobic substance adsorption property and electrical characteristics of the fine bubbles. The dishwasher includes a structure that vibrates a dish basket which stores the washing object in the pre-wash tank, in an up-down, left-right, or up-down and left-right directions, makes the fine bubbles easily enter between the washing objects and can maximize the washing effect as much as possible.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a dishwashing machine, and more particularly to a machine for washing a plurality of dishes such as dishes used in school or hospital lunches at the same time. [Background technology]

[0002] Conventionally, a method has been used in which washing water is sprayed onto the used dishes while they are aligned and stored in a dish basket. In most of these methods, the dish basket is transported on a conveyor, the dishes are washed on the conveyor, and then a rinse is performed for a set period of time. Washing water is sprayed onto the dishes from spray nozzles installed above and below the conveyor.

[0003] However, in order to prevent dishes from being left unwashed using the washing water spraying method of conventional dishwashing machines, it is necessary to leave an appropriate gap between each dish and to ensure that the washing water is distributed over the entirety of the dishes. This is an important issue in a washing method that separates dishes by using the spraying force of washing water, and in order to maintain the distance between each dish, the number of dishes to be stored must be appropriate in relation to the storage volume, i.e., storage space, of the dish basket. If there are too many dishes in the dish basket, the washing water spraying force cannot separate the dishes from each other, and conversely, if there are too few dishes, the dishes will fall forward or backward relative to the arrangement direction, and washing water will not be sprayed over the entirety of the dishes, resulting in some dishes being left unwashed.

[0004] Therefore, to completely remove dirt from the tableware, it was necessary to spray water for a long time. In particular, when oil or starch was attached, the removal was likely to be incomplete, and re-washing was required, which required time and effort. For this reason, dishwashing devices have been proposed recently that utilize the immersion washing effect, in which fine bubbles mixed with air bubbles in the liquid in the immersion tank are used to separate solid dirt attached to the tableware (see Patent Documents 1 and 2 below).

[0005] According to the Japanese Industrial Standards and the International Organization for Standardization (ISO), gas in a medium surrounded by an interface is called a "bubble," and bubbles with a volume-equivalent diameter of less than 100 μm are defined as "fine bubbles (registered trademark)." Among "fine bubbles," bubbles in the range of 1 μm to less than 100 μm are called "microfine bubbles," and bubbles less than 1 μm are called "ultrafine bubbles (registered trademark)."

[0006] Fine bubble water, a liquid that contains fine bubbles, is known to have a cleaning effect on hydrophobic substances (those that are not compatible with water). In other words, the fine bubbles, which are tiny air bubbles, adsorb to oil and other substances adhering to dishes, removing the oil and other substances from the dishes, and when these microscopic bubbles finally disappear, the oil and other substances float in the immersion water in the tub. This oil removal process, which utilizes the effect of fine bubbles adsorbing hydrophobic substances, is applied to the cleaning device. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Special Publication No. 2017-500136 [Patent Document 2] JP 2022-007463 A Summary of the Invention [Problem to be solved by the invention]

[0008] When dishes used in school lunches are cleared, dirt from the front of one dish often adheres to the back of adjacent dishes, and in order to fully utilize the effect of fine bubbles in adsorbing hydrophobic substances, the fine bubbles must be distributed evenly over the entire dish. However, because multiple dishes are stored in a dish basket in an orderly manner with almost no gaps, the fine bubbles may not be distributed over the front, back, and sides of the dishes. As a result, the fine bubbles do not adhere to the dirt on the dishes, and the washing process ends with oil and other residue remaining on the dishes.

[0009] As shown in Patent Documents 1 and 2, the dishwashing machine is configured such that a belt conveyor is provided in an immersion tank storing fine bubble water, and when a dish basket is placed on the belt conveyor, the dishes are conveyed by the belt conveyor in the immersion tank. By sending the dish baskets onto the belt conveyor in sequence, the pre-washing process or the main washing process of fine bubbles can be realized continuously, but the dishwashing machine needs to secure at least the length of the belt conveyor, so the size of the entire machine becomes huge. In addition, in the case of a gradient belt conveyor, the dish basket moves by its own weight in the downward direction of the belt conveyor, so no conveying power is required, and power saving can be achieved. Therefore, it is possible to increase the gradient angle to shorten the length of the belt conveyor and reduce the size of the machine, but there are restrictions on making the gradient large from the viewpoint of safety, and a gentle gradient is unavoidable. As a result, the length of the belt conveyor is extended, and it is not possible to realize a small-sized dishwashing machine.

[0010] Therefore, in order to solve the above-mentioned problems, the present invention aims to provide a dishwashing device that utilizes the hydrophobic adsorption properties of fine bubbles to ensure reliable cleaning and to be compact. [Means for solving the problem]

[0011] In order to solve the above problems, the dishwashing apparatus of the present invention comprises a transport mechanism equipped with rollers for transporting a dish basket containing items to be washed, a pre-washing means for pre-washing the items to be washed, and a main washing means for spraying washing water towards the items to be washed in the dish basket after the pre-washing is completed to perform a main washing process, wherein the rollers are installed at a predetermined inclination so that the dish basket moves toward the pre-washing means under its own weight and moves to the main washing means under its own weight after the pre-washing is completed, and the pre-washing means has a non-horizontal bottom to accommodate the dish basket in an inclined position, and is configured to include a lift mechanism which raises and lowers the dish basket while maintaining the inclination of the dish basket so that the area of ​​contact of the pre-washing water with the items to be washed is increased, and a pre-washing tank equipped with a bubble generating means for generating fine bubbles, and wherein the main washing means sprays washing water towards the items to be washed in the dish basket and washes the items by separating them due to the water pressure of the spray.

[0012] In addition, the lift mechanism of the dishwashing apparatus of the present invention is characterized in that when the dish basket is immersed in the pre-wash tank, it vibrates the dish basket up and down or left and right or up and down and left and right without changing its posture while the fine bubbles are being generated. The pre-washing means further includes a transport stopper for stopping the dish basket at a predetermined position of the pre-washing means when the transport of the dish basket is detected. The transport stopper is released when the end of the pre-washing process is detected, so that the dish basket is moved by its own weight on the rollers at a predetermined gradient. Effect of the Invention

[0013] In the dishwashing apparatus according to the present invention, the pre-washing means is structured to generate fine bubbles in the immersion water in the pre-washing tank, and the fine bubbles are utilized to easily adsorb oil-containing dirt in the immersion water to the fine bubbles, thereby enabling effective washing of the objects to be washed. In particular, the dishwashing apparatus is structured to vibrate the dish basket containing the objects to be washed up and down or left and right or up and down and left and right in the pre-washing tank, so that the fine bubbles can easily penetrate between the objects to be washed, maximizing the washing effect as much as possible. [Brief description of the drawings]

[0014] [Figure 1] 1 is an overall configuration diagram of a dishwashing apparatus according to an embodiment of the present invention; [Diagram 2] 4A and 4B are front and side views of the pre-washing means; [Diagram 3] 13 is a diagram showing the state of the dish basket transported to the pre-washing means. FIG. [Figure 4] 13A and 13B are diagrams illustrating a stopper mechanism in the pre-washing means. [Diagram 5] FIG. 4 is a diagram for explaining water circulation in the pre-washing tank. BEST MODE FOR CARRYING OUT THEINVENTION

[0015] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Fig. 1 is an overall external view of a dishwashing apparatus 100 of this embodiment. The dishwashing apparatus 100 includes a pre-washing means 1 and a main washing means 2. A dish basket 4 placed on rollers 3 moves by itself to the pre-washing means 1. The dish basket 4 and rollers 9b located below the dish basket are transported by lift means 9 into a pre-washing tank 20 of the pre-washing means 1. It is assumed that a plurality of dishes 5 are stored in the dish basket 4 in an orderly manner. When washing in the pre-washing means 1 is completed, the dish basket 4 moves under its own weight on the rollers 7, is placed on the rollers 8, and is transported to the main washing means 2.

[0016] The structure of the pre-washing means 1 will be described with reference to Fig. 2. Fig. 2(a) is a front view showing the outline of the pre-washing means 1, and Fig. 2(b) is a side view thereof. The pre-washing means 1 mainly comprises a pre-washing tank 20, a lifting means 9, and a bubble generator 12. That is, the lifting means 9 moves the tableware basket 4, which has been transported to the center of the main body of the pre-washing means 1, downward to the pre-washing tank 20 installed below. The lifting means 9 is driven by a lift driving motor 13, and the power of the motor 13 is transmitted by a pulley 14 via a driving chain (or belt) 15, enabling the tableware basket 4 to move downward. One side of the driving chain 15 is connected to a base with a counterweight 17 attached, and both ends of the base of the counterweight 17 are also provided with guide rollers (not shown) that come into contact with the main body frame of the pre-washing means 1.

[0017] As the dish basket 4 moves downward, the dishes 5 contained in the dish basket 4 are immersed in the pre-washing tank 20. The rollers 3, 6, 7, and 9b are not horizontal to the ground but are provided with a predetermined incline (for example, about 5°). The dish basket 4 is transported to the pre-washing means 1 at an incline along the inclination of the rollers 6, but the lift means 9 moves the dish basket 4 downward while maintaining its position. In other words, it should be noted that the lift means 9 lowers the dish basket 4 into the pre-washing tank 20 in an inclined state, not horizontal.

[0018] Water is supplied from a pre-washing tank water supply port (not shown) to store cold (or hot) immersion water in the pre-washing tank 20 in advance, and a constant amount is maintained. The pre-washing tank 20 is also provided with at least one bubble generating means 12 connected to a bubble pump 11 (in this embodiment, two are provided facing each other, as shown in FIG. 5). The bubble pump 11 circulates cold or hot water in the pre-washing tank 20, and a nozzle serving as the bubble generating means 12 is attached to its discharge side. During the pre-washing process, the bubble pump 11 is operated, and during that time the bubble generating means 12 mixes fine bubbles into the liquid in the pre-washing tank 20.

[0019] Note that the bubble jetting is not limited to the lateral jetting as shown in FIG. 2, but includes jetting in any direction. In addition, in order to facilitate the diffusion of fine bubbles, a jet nozzle 31 for stirring the water or hot water in the pre-washing tank 20 during the pre-washing process is further attached to the pre-washing tank 20 (see FIG. 5). That is, in the case of this embodiment, water pressurized by one bubble pump 11 is discharged from two bubble generating means 12 and four jet nozzles 31 to stir the water in the pre-washing tank 20. The bubble generating means 12 and the jet nozzle 31 include jetting in any direction, and the bubble pump 11 circulates the water as necessary to maintain the ultra-fine bubble water even after a predetermined amount of water is stored in the pre-washing tank 20.

[0020] The bubble generating means 12 of this embodiment has a structure that combines a Venturi type in which the pressure in the gas-liquid flow path is suddenly changed using the bubble pump 11 to break up the bubbles and mix the fine bubbles into the liquid, and a swirling liquid type in which the bubbles in the liquid are broken up by a high-speed swirling flow to mix the fine bubbles into the liquid, but it may be only a Venturi type or only a swirling liquid type. Alternatively, it may be a pressurized dissolution deposition type in which the gas is saturated in the liquid under pressure and then the pressure is rapidly reduced to precipitate the fine bubbles, or a fine hole type in which the fine bubbles are mixed into the liquid through fine gas dispersion holes. In the present embodiment, as described above, water is stored in the pre-wash tank 20 through the water supply port for the pre-wash tank. However, it is also possible to mix and finely disperse fine air bubbles and water in the bubble generating means 12 to generate ultra-fine bubble water, which can then be supplied from the bubble generating means 12.

[0021] The bubble generating means 12 of this embodiment removes dirt by using ultra-fine bubbles in the liquid in the pre-wash tank 20. The mechanism of cleaning using ultra-fine bubbles will now be described. Because ultrafine and microbubbles are gases, they have the property of easily adsorbing oil droplets and other particles that do not mix with water. In particular, ultrafine bubbles, which are super-fine bubbles with a diameter of less than 1 μm, can remain in water for long periods of time. For this reason, hydrophobic polyphenols such as oil droplets and iron oxide particles dissolved in the liquid (water, hot water, etc.) in the pre-wash tank are also adsorbed by ultrafine bubbles.

[0022] In addition, ultrafine bubbles and microbubbles are formed with a smaller surface tension than simple water droplets, so they can easily enter the small gap between the object to be washed, such as a dish, and the attached dirt, and the dissolved gas concentration increases when the bubbles collide with the dirt, generating microbubbles that are a more stable gas phase. In other words, the ultrafine bubbles form microbubbles that gradually grow larger through repeated collisions, and peel off the dirt attached to the dish. Furthermore, if the microbubbles in the water are given fluidity by ultrasound or the like, the impact on the attached dirt becomes larger, and the peeling force increases.

[0023] Normally, ultrafine bubbles are colorless and transparent (not visible to the naked eye) and remain in the water while undergoing Brownian motion without rising to the surface, but microbubbles are cloudy and visible to the naked eye, and they slowly rise to the surface. Therefore, the ultrafine bubbles in the pre-wash tank gradually grow larger through collisions with dirt, forming microbubbles, which then rise to the surface of the water, carrying oil and other dirt.

[0024] Ultrafine bubbles also have the property of carrying an electric charge. In water, the surface of ultrafine bubbles becomes negatively charged. This means that if there are positively charged substances in the water, they will attract them. Examples of positively charged substances include iron oxide microparticles and carbon microparticles. Food ingredients and foods contain food additives (coloring agents), which contain iron oxide. Iron oxide is commonly used because small amounts produce a vivid color, and because iron oxide that enters the body is absorbed by the intestinal tract after being affected by stomach acid, there is no health concern.

[0025] Therefore, when used dishes are immersed in the pre-washing tank, the immersion water contains iron oxide particles. Ultra-fine bubbles can attract positively charged iron oxide particles due to their electrical properties. In this way, even without the use of detergents or chemicals, ultra-fine bubbles have a high cleaning power and rise to the water surface as microbubbles while combining with various types of dirt. Since water is supplied during washing, microbubbles containing the floating dirt such as oil overflow from the pre-washing tank 20 and are discharged outside the tank, so that the immersion water in the pre-washing tank 20 is kept clean. In addition, a strainer 32 (e.g., punching material) is provided on the pump suction side to prevent dirt in the pre-washing tank 20 from clogging the nozzle of the bubble generating means 12. For the above reasons, the bubble generating means 12 of this embodiment is designed to generate ultra-fine bubbles.

[0026] By immersing the dish basket 4 in the pre-wash tank 20 using the lifting means 9, dirt adhering to the dishes 5 in the dish basket 4 is adsorbed to the fine bubbles by the hydrophobic adsorption properties and electrical properties of the ultra-fine bubbles, and is detached from the dishes 5. To further enhance this effect, the lifting means 9 gently shakes the dish basket 4 up and down, etc., to impart vibrations to the dishes 5 in the dish basket 4. This is because the vibrations temporarily spread the dishes out, making it easier for the wash water to penetrate between the dishes.

[0027] As described above, the dish basket 4 in the pre-wash tub 20 is tilted at an angle, so that the dishes 5 arranged in the dish basket are also tilted. If the tableware 5 is tilted, the area of ​​contact between the tableware 5 and the soaking water containing ultra-fine bubbles increases when the tableware basket 4 vibrates up and down in the pre-wash tank 20. This is because when the tableware 5 are normally arranged vertically and stored, the soaking water hits mostly only the edges of the tableware 5 because the intervals between the dishes are narrow, but when the tableware are arranged at an angle, the edges are misaligned, and the area subjected to water pressure increases accordingly. Once the edges of the tableware begin to open, water hits the slanted inner surfaces of the tableware, making it easier for the intervals between the tableware to open up even further, making it easier for the ultra-fine bubbles to cover the entire tableware. Note that the projection of ultra-fine bubbles onto the bottom surface of tableware arranged at an angle is greater than that of tableware arranged vertically, so that ultra-fine bubbles may come into contact with the tableware more easily. In this embodiment, the vibration applied to the dish basket 4 by the lift means 9 is in the vertical direction, but instead of or in addition to the vertical vibration, the vibration may be in the left-right direction.

[0028] Next, the stopper 21a shown in FIG. 3 and FIG. 4 will be described. The rollers 3, 6 are installed at an incline so that the dish basket 4 moves under its own weight towards the pre-washing means 1. As shown in Figure 4(a), a stopper 9a is provided at the end of roller 9b that supports the dish basket 4 in the lifting means 9 so that the entire dish basket 4 can be stopped by the lifting means 9. The stopper 9a is collapsible, and when it rises towards the roller 9b, the dish basket 4 remains on the lifting means 9 and does not move. When it falls towards the roller 7, the stopper is released and no longer supports the dish basket 4, so the dish basket 4 moves under its own weight towards the roller 7.

[0029] Also, instead of the collapsible stopper 9a, a stopper may be used as shown in Fig. 4(b) in which a stopper claw 21a stands up when the stopper is activated to prevent the dish basket 4 from moving away from the lift means 9. As shown in Fig. 4(c), when the stopper claw 21a moves below the roller 9b, the stopper is released. Alternatively, a structure may be adopted in which a perforated metal platform is provided below dish basket 4, rollers 9b are attached onto the platform, and a jig is provided for controlling the inclination of rollers 9b.

[0030] The timing of the tilting of the stopper 9a is, for example, as follows. When a predetermined basket position sensor switch detects the time when the tableware basket 4 moves to the lift means 9, the stopper drive motor 10 controls the stopper 9a to rise toward the roller 9b. Also, when the up-down position sensor switch detects that the lift means 9 has risen after the pre-washing, the stopper drive motor 10 controls the stopper 9a to fall toward the roller 7 in the moving direction. The timing of the tilting may be controlled based on the elapsed time from the time when the tableware basket 4 is placed on the roller 3, or the operation button 16 may be used to manually start and release the stopper. Furthermore, since the rollers 3 and 6 are inclined, a similar stopper may be installed at the end of the rollers 3 and 6 to control the movement of the tableware basket waiting for the start of the pre-washing.

[0031] After the pre-washing process is completed, the dish basket 4 proceeds to the main washing process by the main washing means 2. In this embodiment, in order to transport the dish basket 4 to the main washing means 2 without using power, a sliding member 18 (see FIG. 3) made of a material such as fluororesin or silicone resin is provided on one or both sides of the side of the dish basket 4 at the point where the lifting means 9 comes into contact with the dish basket 4, improving the sliding property of the dish basket 4 moving to the main washing means 2.

[0032] In the main washing means 2, washing water is sprayed from a spray nozzle toward the tableware 5 from any direction, such as up and down or left and right. In this embodiment, the main washing is a so-called separation method in which the tableware is separated from each other by the spray force of the washing water while being washed, but it may be an immersion method like the pre-washing. In addition, if necessary, the washing process is completed after the main washing via a drying means.

[0033] According to the dishwashing apparatus of this embodiment, fine bubbles effectively remove objects to be washed such as dishes in the pre-washing tank of the pre-washing means, and in particular, by vibrating the dish basket up and down or left and right or up and down and left and right while the objects to be washed are tilted, the fine bubbles are more likely to get between the objects to be washed. This provides a greater cleaning effect than conventional dishwashing apparatuses, and also makes it possible to reduce the size of the dishwashing apparatus by moving the dish basket up and down using the lifting means to move it to the pre-washing tank. [Explanation of symbols]

[0034] 1 Pre-wash cleaning method 2. Washing and cleaning means 3. Roller 4. Dish basket 5. Tableware 6 Roller 7. Roller 8. Roller 9 Lifting means 9a Stopper 9b Roller 10 Stopper drive motor 11 Bubble pump 12. Means of bubble generation 16 Operation buttons 18 Sliding member 20 Pre-wash tank 21a Stopper claw 100 Dishwashing equipment

Claims

1. A conveying mechanism having rollers for conveying a dish basket containing items to be cleaned; A pre-washing means for pre-washing the object to be washed; a main washing means for spraying washing water toward the items to be washed in the dish basket after the pre-washing process is completed, and Equipped with The rollers are installed at a predetermined gradient so that the dish basket moves toward the pre-washing means under its own weight and moves to the main washing means under its own weight after the pre-washing, The pre-washing means includes a lift mechanism that raises and lowers the dish basket while maintaining the inclination of the dish basket so that the area of ​​contact of the pre-washing water with the items to be washed is increased, and a pre-washing tank in which a bubble generating means that generates fine bubbles is installed, The main washing means of the dishwashing apparatus sprays washing water toward the items to be washed in the dish basket, and washes the items by separating them from each other due to the water pressure of the spray.

2. The dishwashing apparatus according to claim 1 , wherein the lift mechanism, when the dishwashing basket is immersed in the pre-wash tank, vibrates the dishwashing basket up and down or left and right or up and down and left and right without changing its posture while the fine bubbles are being generated.

3. 2. The dishwashing apparatus according to claim 1, wherein the pre-washing means further comprises a transport stopper for stopping the pre-washing means at a predetermined position when transport of the dish basket is detected.

4. 4. The dishwashing apparatus according to claim 3, wherein the transport stopper is released when it detects the end of the pre-washing process, so that the dish basket is moved by its own weight on the rollers at a predetermined gradient.

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