JPS63183035A - Filter apparatus of tableware washing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a filter device for a dishwasher that captures leftover food and the like in a washing tank.

BACKGROUND ART FIG. 6 shows an example of a dishwasher. In FIG. 5, a cleaning tank 2 is arranged inside an outer tank 1, and a cleaning liquid circulation pump 3 is provided below the cleaning tank 2. The washing tank 2 has a washing nozzle 5 that spouts out the washing liquid 4 while being rotated by the water pressure of the washing liquid circulation pump 3, and a tableware basket 6 is disposed, and tableware 7 is placed in the tableware basket 6. The tableware 7 is washed with the washing liquid 4 spouted from the washing nozzle 5. Add detergent to cleaning solution 4 in advance. Furthermore, at the bottom of cleaning tank 2,
A heater 8 is provided, and cleaning liquid 4f: cleaning is performed while being heated. At this time, the cleaning liquid 4 is circulated by the cleaning liquid circulation pump 3 for cleaning, but in order to prevent the leftovers washed from the tableware 7 from re-adhering to the tableware 7,
A filter 9 is placed at the bottom of the cleaning tank 2, and the cleaning liquid 4 is
is filtered and purified by filter 9.

Cleaning is carried out while circulating the filtered and purified cleaning liquid 4 using the cleaning circulation pump 3. After cleaning for a certain period of time, drain pump 1o
The cleaning liquid 4 is discharged to the outside of the machine, and then fresh water is supplied again and rinsing is performed several times in the same manner as cleaning. Furthermore, after that, the tableware 7 is heated and dried by the heater 8, and the process is completed.

FIG. 6 shows details around the conventional filter device. A filter 9 made of a stainless steel plate having a plurality of small holes on the outer periphery of a recess 11 provided at the bottom of the cleaning tank 2 made of a stainless steel plate.
The cleaning liquid is filtered with this configuration.

Problems to be Solved by the Invention Conventional filters are manufactured by press-molding a stainless steel plate having a large number of small holes.

In this case, the outer peripheral edge of the filter is bent in consideration of safety. However, this bending may damage the stainless steel surface of the filter body, and the stress caused by bending may reduce the inherent corrosion resistance of the stainless steel, making it susceptible to rust. Furthermore, when the cleaning tank 2 and the filter outer peripheral edge 9a are in contact as shown in FIG. Scratches occur on the surface. Scratches destroy the passivation film that maintains the corrosion resistance of the stainless steel surface, making it susceptible to rust. If the parts where the corrosion resistance of the stainless steel deteriorates further create a gap structure, sufficient oxygen cannot be supplied, and the passivation film cannot be regenerated and rust occurs. The phenomenon in which stainless steel rusts in the crevice structure is called "crevice corrosion" of stainless steel, and is a phenomenon unique to stainless steel.

It is generally known that in crevice corrosion of stainless steel, chlorine ions present in the water in the crevices are concentrated, and the concentrated chlorine ions destroy the passivation film, resulting in rust.

When used in the configuration shown in the conventional example in Fig. 6, the cleaning tank 2
Since a narrow gap is formed in the area where the recess 11 provided at the bottom of the filter contacts the outer peripheral edge 9Δ of the filter, the above-mentioned crevice corrosion may occur.

Furthermore, destruction of the passivation film due to scratches on the surfaces of the cleaning tank 2 and the filter outer peripheral edge 9a caused by sliding will promote rust formation due to "crevice corrosion".

In view of the above-mentioned problems, the present invention has been developed to prevent corrosion that occurs in the gap formed between the recess provided at the bottom of the cleaning tank 2 and the filter.
Furthermore, as the corrosion progresses, it becomes pitting corrosion, which is typical of stainless steel, and not only does rust occur, but holes also form on the surface of the cleaning tank and filter. The purpose of this is to prevent cleaning fluid from leaking from inside the cleaning tank, which would otherwise occur.

Means to Solve the Problem In order to solve this problem, the present invention provides a frame body made of resin with an abbreviated cross-section on the outer periphery of the filter body,
The filter body is placed at the bottom of the cleaning tank in a non-contact manner via the frame.

Function: With the above configuration, the filter body is placed at the bottom of the cleaning tank in a non-contact manner via the resin frame whose cross section is shaped like an abbreviated letter on the outer periphery of the filter body, and the sliding action between the stainless steel pieces is achieved. Since the passivation film is not destroyed, there is no decrease in corrosion resistance.

In addition, "crevice corrosion" may occur in the gap structure formed by the frame and the filter body, and the frame and cleaning +1, but in the gap between the frame and the filter body, the cross section of the frame By forming the filter into an abbreviated shape and leaving one side of the outer periphery of the filter body open, moisture remaining in the gap evaporates faster and comes into constant contact with oxygen in the air. As a result, the passivation film that would otherwise be destroyed by the chlorine ions concentrated in the water in the gap is regenerated, thereby preventing corrosion.

Similarly, since the frame is made of resin, the gap between the frame and the bottom of the cleaning tank can be shaped freely.For example, the frame can be shaped into a V-shape to minimize the contact area between the two. ,
A similar effect can be achieved by accelerating the evaporation of moisture remaining in the gaps.

Embodiment An embodiment of the present invention will be described using FIGS. 1 to 4. In FIG. 1, reference numeral 12 denotes a substantially dish-shaped filter body, which is made of a stainless steel plate, and consists of a punching plate with a large number of small holes of about one diameter to allow the cleaning liquid to pass through but not to let the leftover food pass through. Reference numeral 13 denotes a frame made of synthetic resin, and the inner surface of the frame 13 is brought into contact with a protrusion 131L provided integrally, and the frame is inserted and locked onto the outer peripheral edge of the filter body 12.

FIG. 2 shows the cross-sectional structure of the thus obtained filter device placed in the recess 14 & of the cleaning tank 14 made of a stainless steel plate. As shown in FIG. 2, by attaching the frame 13 to the outer peripheral edge of the filter body 12,
There is no need to bend the outer periphery for safety reasons. Therefore, the surface of the filter body 12 is not scratched or stress is applied during bending, so the filter body 12 itself is less likely to rust than in the past. Furthermore, since the filter body 12 is placed in the cleaning tank 14 via the frame 13, no gap structure is created where the stainless steel pieces come into contact with each other. Therefore, "crevice corrosion" between the filter and the cleaning tank, which easily occurs in the conventional example shown in FIG. 6, is less likely to occur.

Furthermore, the filter vibrates due to the flow of cleaning fluid, etc.
Even if it slides on the surface of the cleaning tank 14, the frame body 13 made of synthetic resin and the stainless steel will not be scratched because the stainless steel surface is harder, and the passivation film will not be destroyed. do not have. Therefore, the inherent corrosion resistance of stainless steel can be maintained. However, in the configuration shown in FIG. 2, gaps are formed between the frame 13 and the filter body 12, and between the frame 13 and the cleaning tank 14.

In this case, the possibility is clearly lower than the possibility of "crevice corrosion" occurring between stainless steels, but
This does not completely eliminate the possibility of "crevice corrosion" occurring. Below, the frame 13, the filter body 12, and the frame 1
3 and the cleaning tank 14 will be explained.

FIG. 3 shows the frame 13 and the outer peripheral edge 12 of the filter body 12.
An enlarged view of the state of contact with is shown. As shown in FIG. 3, the frame 13 is shaped like an oval, and
22L is brought into contact with the inner surface of the frame 13. As a result, a gap 15 is formed between the frame 13 and the outer peripheral edge 12& of the filter main body 12, but in the configuration shown in FIG. 3, one side of the outer peripheral edge 122L of the filter main body 12 is open. This makes it difficult for water to remain in the gap 16. Even if water remains in the gap 15, since one side is open, air permeability will be good and drying will be improved.

In other words, even if water accumulates in the gap 16 and the passivation film is destroyed by the chlorine ions present in the water and "crevice corrosion" begins to occur, the water present in the gap 15 will easily evaporate and dry. Therefore, when oxygen in the air is supplied, the passivation film destroyed by the left side is regenerated, allowing stainless steel to continue to maintain its inherent corrosion resistance.

The same holds true for the gap 16 between the frame 13 and the cleaning tank 14. In other words, since the frame body 13 is made of synthetic resin, the contact portion 13bi that contacts the cleaning tank 14 is made as small as possible. For example, as shown in FIG.
b has a substantially V-shaped cross section, and is brought into linear contact with the cleaning tank 14. As a result, the gap 16 between the frame 13 and the cleaning tank 14 has a linear gap structure. With the linear gap structure, it is even more difficult for water to accumulate, and even if water does accumulate, it dries easily, and "crevice corrosion" can be prevented as in the case of the frame 13 and the filter body 12.

FIG. 4 shows another embodiment of the invention. This has the same basic concept and structure as the previously described embodiment, but whereas the previous embodiment has a frame 13 that is detachable, the embodiment shown in FIG. It is characterized by being integrally molded on the outer peripheral edge 181L of the filter body 18. In other words, the frame 17 is replaced by the filter body 18.
It is formed by outsert molding on the outer peripheral edge 182L of. With this configuration, the outer peripheral edge 1 of the frame body 17 and the filter body 18 is similar to the previous embodiment.
8a, and “crevice corrosion” between the frame 17 and the cleaning tank 19
In addition, it is possible to completely prevent fine debris from entering between the frame 13 and the outer peripheral edge 122L of the filter body 12, which was possible in the previous embodiment. Also,
In the previous embodiment, the frame 13 had to be molded and assembled into the filter body 12, but the embodiment shown in FIG. 4 is characterized in that the assembly work can be eliminated.

Effects of the Invention As described above, according to the present invention, even if the filter device and cleaning tank are made of stainless steel, by bringing them into contact through a resin frame, "crevice corrosion", which is a characteristic of stainless steel, can be avoided. ”, rust generation and leakage, as well as holes in the cleaning tank caused by the progress of rust, can be prevented. This prevents the cleaning liquid from flowing out of the tank and extends the product's durable life.

[Brief explanation of the drawing]

FIG. 1a is a plan view of a filter device showing an embodiment of the present invention, FIG. FIG. 3 is a cross-sectional view of the main part of the same filter device, FIG. 4 is a cross-sectional view of the main part of the filter device showing another embodiment, and FIG.
The figure is a cross-sectional view showing the overall structure of the dishwasher, and FIG. 6 is a cross-sectional view of essential parts showing a conventional filter device and the state of contact between the filter device and the bottom of the washing tank. 12... Filter body, 13... Frame, 132L... Protrusion. Name of agent: Patent attorney Toshio Nakao and 1 other person/2
--Fill goo 1/3・-Valve body 1 Figure 13α-Protrusion ("
(b) HiM Figure 3

Claims (4)

[Claims] (1) A filter device for a dishwasher, in which a resin frame having a substantially L-shaped cross section is provided on the outer peripheral edge of a filter body, and the filter body is placed at the bottom of a washing tank in a non-contact manner via the frame. (2) A filter device for a dishwasher according to claim 1, wherein the frame body is detachably attached to the outer peripheral edge of the filter body. (3) A filter device for a dishwasher according to claim 2, wherein the frame body is provided with a protrusion that is inserted into and engaged with the outer peripheral edge of the filter body. (4) A filter device for a dishwasher according to claim 1, wherein the frame body is integrally formed on the outer peripheral edge of the filter body.