JPH0320738Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to the structure of a water level detector installed in a hot water storage tank that stores hot water such as rinse water for a dishwasher.

(Prior art) Dishwashers are equipped with a water level detector to detect the amount of hot water inside a hot water storage tank, such as a cleaning liquid tank installed at the bottom of the cleaning chamber or a rinse water tank installed near the cleaning chamber. However, instead of the float type, electrode rod type water level detectors, which detect the water level of hot water as changes in electrical resistance, are often used.

A hanging type water level detector of this type has a structure shown in FIG. 2, and has, for example, two electrode rods 4,
are fixed to a horizontal mounting base 3' and suspended vertically in the hot water storage tank 1.The horizontal mounting base 3' is formed from an insulating flat plate, and each electrode rod 4,
The upper end of 4 is passed through a hole drilled in the flat plate, and is fixed by tightening nuts 7 from both sides. Then, a minute voltage of several volts is applied between the two electrode rods 4, 4, and when the water level in the hot water storage tank rises and the water surface touches both electrode rods 4, 4, the two electrode rods 4, 4 are electrically connected to electrically detect the water level.

(Problems to be Solved by the Invention) In the conventional structure described above, when condensation occurs on the lower surface of the horizontal mounting base 3' due to steam rising from the hot water phase, both electrode rods 4, Even though the electrodes 4 are electrically connected and the liquid level is not in contact with the electrode rods 4, 4, the water level is detected as if it had reached a predetermined liquid level, resulting in an inconvenience that may lead to malfunction.

In addition, the area around the hot water storage tank 1 often becomes humid due to the presence of steam, and at this time dew accumulates on the upper surface of the horizontal mounting base 3', forming a water film, which causes damage to both electrodes as well as the lower surface. There was a problem in which it was determined that the rods 4 and 4 were electrically conductive and the liquid level had reached a predetermined level, causing a malfunction.

In view of the fact that conventional water level detectors have low detection accuracy and reliability problems, the present invention has been made to provide an improved water level detector that can overcome the conventional deficiencies. The purpose of the invention is to suppress the deterioration of insulation resistance due to moisture by providing an insulating partition plate and cylindrical seat part on the horizontal mounting base, thereby achieving stable maintenance of water level detection accuracy. do.

(Means for Solving the Problems) The present invention is to fix two or more electrode rods 4, 4 to a horizontal mounting base 3 and hang them down, and to vertically arrange the electrode rods in a hot water storage tank 1. In the water level detector 2, which detects the water level by conducting between the plurality of electrode rods 4, 4 when the electrode rods 4, 4 contact the water surface, the horizontal mounting base 3 is provided with a partition between adjacent electrode rods 4, 4. Insulating partition plates 5 are provided upright and downward from both the upper and lower surfaces of the board, and the upper ends of each electrode rod 4, 4 are inserted into the electrode mounting portion on the upper surface of the horizontal mounting base 3. The structure is such that insulating cylindrical seat portions 6 are respectively erected.

(Function) By providing the partition plate 5, the present invention reduces the communication of the water film that occurs along the surface of the horizontal mounting base 3, or prevents the maintenance of insulation resistance due to an increase in the creepage distance. In addition, the cylindrical seat part 6 raises the terminal part,
Similarly, conduction between the terminals due to the water film can be prevented and erroneous detection can be eliminated, so that the intended purpose is achieved.

(Example) An example of the present invention will be described below based on the accompanying drawings.

In Fig. 1, reference numeral 1 is a hot water storage tank in a dishwasher, in which a fixed amount of rinsing water is stored, and when the washing cycle is completed, the clear rinsing water in the tank 1 is sent to a spray nozzle (not shown). Spray it on the dishes in the washing room and use it for rinsing.

This hot water storage tank 1 has a wide-mouthed bottle shape, has a water level detector 2 hanging vertically from its upper opening, and is attached to a horizontal mounting base 3 by means of a cap 8 with a gasket 9 interposed therebetween.
is fixed, and the upper opening is closed with the mounting base 3.

The water level detector 2 has an insulating horizontal mounting base 2,
It is formed from two electrode rods 4, 4 fixed to the electrode mounting part of the mounting base 2 with nuts 7 and suspended,
A conducting wire is connected to each electrode rod 4, 4, and a minute voltage of several volts is applied between the two electrodes.

The electrode rods 4 are made of stainless steel, and in the illustrated example, two electrode rods 4, 4 of equal length and level are installed vertically because it is only necessary to detect a predetermined water level. If it is necessary to detect the water level, one longer electrode rod 4 may be added and installed vertically.

Although the horizontal mounting base 3 is integrally provided with the partition plate 5 and the cylindrical seat portion 6, in the illustrated example, since the horizontal mounting base 3 is made of an insulating material, both members 5,
6 are integrally molded.

The partition plate 5 is arranged to partition the adjacent electrode rods 4, 4, and is vertically raised and lowered from both the upper and lower surfaces.On the other hand, the cylindrical seat part 6 is provided on the upper surface of the electrode mounting part. , the upper end of the electrode rod 4 is formed into a short tube through which the length of several mm is inserted, and is set upright.

The upper ends of the electrode rods 4, 4 are inserted through the flat plate portion and the cylindrical seat portion 6 of the horizontal mounting base 3, and are clamped and secured by nuts 7, 7 from both upper and lower sides.

The water level detector 2 having the above configuration is configured so that when the hot water storage tank 1 is replenished with hot water and reaches a predetermined amount, the electrode rods 4 are short-circuited by the liquid level layer of the hot water storage. , a current flows through the electrode rods 4, 4 to which a low voltage is applied.

Therefore, since it is possible to detect that the amount of stored hot water has reached a predetermined value as a change in the electrical signal, replenishment of hot water is stopped by means such as closing the hot water supply valve.

By the way, the space inside the hot water storage tank 1 is filled with steam due to the high temperature water, and the presence of this steam moistens the lower surface of the horizontal mounting base 3.

However, since the partition plate 5 is provided, the dew is cut off at the lower edge of the partition plate 5, and the creepage distance between the electrode rods 4 is long, so that the horizontal mounting The problem of electrical conduction between the electrode rods 4 and 4 due to the water film formed on the lower surface of the electrode rods 3 is solved.

On the other hand, if the area around the hot water storage tank 1 is under high humidity conditions, the upper surface of the horizontal mount 3 will also become moist, but because of the provision of the partition plate 5, the electrode The problem of conduction between the rods 4 is eliminated.

Furthermore, even if water accumulates on the top surface of the horizontal mounting base 3, since the cylindrical seat portion 6 is provided, the electrode rods 4, 4 will not come into contact with the layer of accumulated water, and there is no risk of insulation deterioration. That's not it at all.

(Effects of the invention) By providing the partition plate 5, the present invention can effectively prevent the insulation resistance between the electrodes 4, 4 from decreasing due to the influence of moisture. Since the exposed portions of the rods 4, 4 are lifted from the top surface of the horizontal mount 3, the electrode rods 4, 4 are also prevented from coming into contact with the water film on the horizontal mount 3, and thus the water between the electrode rods 4, 4 is The inconvenience that the insulation resistance decreases due to moisture on the lower surface of the horizontal mounting base 3 or a water film on the upper surface of the horizontal mounting base 3 is solved here, and the electrodes are not connected until the plurality of electrode rods 4, 4 are in contact with the water surface of the hot water storage tank 1. Bars 4, 4
As a result, a water level detector that does not malfunction, maintains high detection accuracy, and has excellent moisture resistance can be provided.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram of main parts of a hot water storage tank according to an embodiment of the present invention, and FIG. 2 is a structural diagram of main parts of a hot water storage tank of a conventional dishwasher. 1...Hot water storage tank, 2...Water level detector, 3...
Horizontal mounting base, 4... Electrode rod, 5... Partition plate, 6...
...Cylinder seat part.

Claims (1)

[Scope of utility model registration request] Two or more electrode rods 4, 4 are mounted on a horizontal mounting base 3.
When the plurality of electrode rods 4, 4 are in contact with the water surface, conduction occurs between the plurality of electrode rods 4, 4, and the water level is lowered. In the water level detector 2 for detection, insulating partition plates 5 are provided to separate the adjacent electrode rods 4, 4 from both the upper and lower surfaces of the horizontal mounting base 3, respectively, by raising and lowering them. Water level detection for a dishwasher, characterized in that an insulating cylindrical seat part 6, into which the upper end of each electrode rod 4, 4 is inserted, is provided upright on the electrode mounting part on the upper surface of the horizontal mounting base 3. vessel.