JPH01178227A - Dish washer - Google Patents

Abstract

PURPOSE:To check perfectly the failure on account of dirty things by automatically controlling a water level in a washing vessel and detergent concentration in washing water by a method wherein one sensor simultaneously detects detergent concentration and water level, of the washing water in a washing vessel. CONSTITUTION:When voltage of movable terminals L is set for proper value by properly selecting the value of variable resistance VR, detergent concentration may be adjusted by observing light indication, wherein light emitting device of LED and the like indicates a state of density, since Q1-Q5 successively show level (L), that is, turn conductive, wherein they are outputted terminals of IC2. A constant detergent concentration is maintained at all times when wash feeder is automatically controlled by using of output signal of the output terminals (Q1-Q5). When the water level of wash water or hot water is lowered in a washing vessel 1 and a pair of electrode 2a and 2b appear in the hot water, in addition, a constant water level is held in the vessel 1, since the output terminal Q5 shows level (L), SSR stays ON, a hot water supply valve 5 is opened, and hot water is supplied. Occurrence of failure can be prevented by providing the sensor which is, in such cases, cheaper and has little failure.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a dishwashing device that detects the concentration and water level of a solvent solution such as a cleaning liquid and automatically controls the concentration and water level.

(Prior art and its problems) Conventionally, this type of dishwashing equipment has a temperature of 60 to 70°C.
After washing off the dirt adhering to the dishes with a washing solution made by dissolving an appropriate amount of detergent in water at °C, the dishes are rinsed with warm water and dried.The washing tank that holds this washing solution and hot water is equipped with a water level meter. Generally, a float switch or pressure switch, etc. is attached. Here, as shown in FIGS. 8(A) and 8(B), the float switch is a cylindrical pipe 22 with stoppers 21a and 21b formed at the upper and lower ends.
The float 23 moves up and down following the water level of the cleaning liquid, etc., and as a result, the magnet 24 provided inside the float 23 turns the reed switch 25 on and off, as shown in FIG. The water level is measured by

Furthermore, as shown in FIGS. 9(^) and (B), when cleaning liquid or the like is poured into the casing 27 of the pressure switch 26, the diaphragm D is pressed upward in the figure, and accordingly Similarly, the axis T moves upward in the figure, the switch S is turned on and off, and the water level is measured.

However, in conventional dishwashing devices equipped with such a float switch 20 or pressure switch 26,
In the case of the float switch 20, calcium contained in the cleaning liquid and oils and fats in the dirt adhering to the dishes adhere to the sliding contact surface between the vibrator 22 and the float 23 that moves up and down along the pipe 22. Problems such as the float 23 not working or, in the case of the pressure switch 26, calcium, oil, etc. accumulating in the casing 27 of the pressure switch 26 causing the switch to not work, often result in malfunctions. have.

(Means for solving the problem) The present invention has been proposed in view of the above points.
The purpose of this is to simultaneously detect the detergent concentration in the cleaning solution in the cleaning tank and the water level of the cleaning solution with a single sensor, and to automatically control the water level in the cleaning tank and the concentration of the cleaning solution to achieve optimal cleaning. To provide an inexpensive dishwashing device which can wash dishes under certain conditions and can completely prevent breakdowns due to dirty objects.

That is, the dishwashing device according to the present invention is a dishwashing device equipped with a sensor that measures the detergent concentration and water level of a cleaning tank containing cleaning liquid, hot water, etc., wherein the sensor includes a pair of electrodes, and The detection circuit detects the voltage change based on the resistance value of the cleaning liquid between the two, measures the detergent concentration and water level of the cleaning liquid based on this detection signal, and sends the detection signal to the IC circuit that inputs the preset reference concentration and reference water level. The above object is achieved by inputting and comparing the values and controlling the solvent concentration and water level based on the comparison values.

(Function) If the pair of electrodes of the sensor are arranged on the inner surface of the cleaning tank and facing the center of the reference water level position of the cleaning liquid, the resistance value between the pair of electrodes will increase when the cleaning liquid is below the reference water level. If it reaches infinity and the cleaning liquid is above the standard water level, the cleaning liquid is interposed between the pair of electrodes and a type of electrolysis occurs, resulting in a conductive state. If this is detected, the water level of the cleaning liquid is automatically controlled. Can be done.

On the other hand, when a pair of electrodes is located in the cleaning liquid, the detergent weight % in the cleaning liquid, for example, in the range of 0.1 to 0.3 weight % in the figure, as shown in FIG. and the resistance between the pair of electrodes (for example, the voltage at point L) are in a substantially proportional relationship, and by measuring the voltage value at point L, the detergent weight % can be accurately detected. Therefore, by comparing the concentration with a preset reference concentration and adding detergent or water based on the deviation value, it is possible to automatically control the concentration to a predetermined concentration.

(Disclosure of invention) The present invention will be explained below with reference to the drawings.

Figures 1 and 2 show an embodiment of the present invention which serves both as a cleaning liquid concentration meter and a water level meter.
A pair of electrodes provided in the cleaning tank 1, a detection circuit 3 that detects the voltage between the pair of electrodes 2, and a detection circuit 4 that converts the detection signal for the water level meter and the detection signal for the concentration meter from the detection circuit 3 into an analog signal voltage level. This is an IC circuit that converts and displays the data, and consists of IC1 and tCZ. CI and IC7 are linear level indicator elements that are widely used when displaying analog signal voltage levels using LEDs or the like.

As shown in FIG. 1, this detection circuit 3 consists of a water level detection circuit 3a and a cleaning liquid concentration detection circuit 3b.The water level detection circuit 10a has a power supply +Vcc connected to a linear level indicator element IC1 and one electrode 2a. The other electrode 2b is connected to the input terminal of the linear level indicator element IC via a resistor R8 through a branch point H, and the GND terminal of the linear level indicator element IC is grounded to G. has been done.

On the other hand, in the cleaning liquid concentration detection circuit, the power supply +Vcc is a linear level indicator element IC! and one electrode 2a
The other electrode 2b is connected to the input terminal of the linear level indicator element ICz via the resistor Rt through the branch point H, the movable terminal of the variable resistor VR, and the input terminal of the linear level indicator ICz to form a circuit. The other end of VR and the GND terminal of linear level indicator element tCZ are each grounded to G.

The following relationships hold between the resistors R3 and R8 in both detection circuits and the variable resistor VR.

R+ (Rt V R<Rz-4, the linear level indicator element IC,, Icz is composed of a voltage network for analog signal level detection and five comparators, as shown in FIG. The transistors are connected in order of low voltage output side, Q,.

Mouth L Q3. Output terminals Qa and Qs are provided.

This linear level indicator element IC, and IC,
As shown in Table 1, the funxilan table of
Input voltage 200+wV! :# In the oven, the collector output Q is at "L" level, and the outputs from Q2 to Q are each configured to operate at 200 mV. And input voltage 1000100O)
All outputs become "L" level.

Table 1 The operation of the dishwashing apparatus equipped with the concentration meter and water level meter having such a configuration will be described below.

When no cleaning liquid or hot water is injected into the cleaning tank 1, when a low voltage of about 5 to 12 cm is applied between the power supply Vcc and the ground G, there is no conduction between the pair of electrodes 2a and 2b. , the resistance value is approximately infinite ((X)).

Therefore, the voltage v, I between point H and ground G is the ground level (Vllζ0), and therefore the voltage between point L and ground G
The voltage between .

Therefore, ICI and IC! Since no input voltage is supplied to the input terminals of Q, no signal is output to the output terminals of Q, ~Q,.

Next, cleaning liquid or hot water is poured into the cleaning tank 1,
When the pair of electrodes 2a and 2b are immersed, the pair of electrodes 2a and 2b
A and 2b become conductive, and the resistance value between the power supply Vcc and point H decreases. (At this time, for example, a pair of electrodes 2a, 2
When the distance b is approximately 201, the resistance value is several hundred ohms.) Then, when the voltage of the power supply Vcc is applied to the detection circuit,
The voltage vN is the resistance between the pair of electrodes 2a and 2b and the variable resistance V
It becomes a partial pressure value with respect to R and is inputted to the IC via the resistor R+, and the presence or absence of the reference water level of the cleaning liquid or hot water in the cleaning tank 1 can be taken out as an output of the IC. By operating the cleaning liquid supply device by turning on and off this output signal, the water level in the cleaning tank can be automatically controlled.

In addition, here, ICI and commercially available I used for ICi are
If the variable resistor VR is set so that the voltage of the C element becomes 1 V or more when the pair of electrodes 2a and 2b are immersed in cleaning liquid or hot water, the output terminal becomes low (L ) That is, conduction occurs, so this signal can be used to display the water level (cleaning liquid level) or to control the hot water supply valve.

Next, the operation of detecting the concentration of the cleaning liquid in the cleaning tank 1 using CZ will be explained.

Figure 3 shows the voltage across the movable terminal and the weight ratio of hot water and detergent; when detergent is dissolved in hot water, the concentration by weight is 0.
In the range of 0.05% to 0.3%, the characteristics are approximately linear, and the voltage increases as the concentration increases, but when it exceeds 0.3%, the voltage is approximately saturated.

Therefore, if the value of the variable resistor VR is appropriately selected and the voltage across the movable terminal is set to an appropriate value, the output terminals Q1 to 0 of the IC, depending on the detergent concentration. Since it becomes low (L), that is, conductive, in the order of
By automatically controlling the detergent supply device using the output signals 1 to Q, it is possible to maintain a constant detergent solution concentration at all times.

Note that when using the level indicator etc. shown in Figure 2, the input voltage level is designed to be controlled linearly from Ov, so if the characteristics shown in Figure 2 are applied as is, the result in Figure 3 will be As shown, in a range where 0.05% or less is not linear, problems such as concentration and display not matching may occur.

In the above case, as shown in Figure 4, the G of IC1
Although it may be necessary to take measures such as connecting a Zener diode D and a capacitor C in parallel between the ND terminal and the ground G to bypass the alternating current, the cleaning liquid of the dishwashing equipment currently in use may be necessary. The concentration of is 0.1-0.2
The cleaning effect is best in the range of 0.05 to 0.3%, and therefore the concentration of the cleaning liquid is in the range of about 0.05 to 0.3%, and there is no problem even if the Zener diode D and the capacitor C are omitted.

Further, the resistance value of the concentration of the cleaning liquid changes slightly depending on the temperature of the cleaning liquid, and the resistance value between the electrodes may decrease as the temperature increases. In such a case, in order to prevent malfunction, the fifth
The temperature compensation circuit of the thermistor T can be connected in parallel to the variable resistor VR as shown in Figure (A), or connected in series between the electrode and the variable resistor VR as shown in Figure (B). Therefore, the concentration of the cleaning liquid can be accurately detected even when the temperature of the cleaning liquid changes.

However, the liquid temperature in the washing tank of dishwashing equipment currently in practical use is usually 50 to 7
Since the temperature is controlled within the range of 0°C, there is no problem even if the temperature correction circuit such as the thermistor is omitted.

In addition, the salt contained in soiled objects on dishes has the property of reducing the resistance value between the electrodes more than detergent when using only hot water, but salt is mixed into cleaning solutions using detergents that are currently in use. Experiments have shown that the characteristics shown in Figure 3 will not be affected unless the salt concentration increases significantly, so in practice, there is no problem even if the salt concentration in the cleaning solution changes. do not have.

In Figure 1, a DC potential is applied between the electrodes 2a and 2b, but there is a slight difference in the measured value when the cleaning solution is stationary and when it is flowing due to electrolysis of the solution, etc., but in practical use. There is no problem above.

If you want to further stabilize the measurement value, use 40KH2~50
The potential may be applied in an alternating current manner at a frequency of approximately KHz. According to experiments, it has been confirmed that the stability improves from about 10 KHz and becomes extremely stable at about 40 KHz to 50 KH2.

FIG. 6 is a diagram showing another embodiment of the present invention, and shows an example of a circuit configured to keep the water level of the cleaning tank constant by using the detection circuit as a water level gauge.

In this detection circuit, when the cleaning liquid or hot water is not poured into the cleaning tank 1, the pair of electrodes 2a, 2b
Since it is in a non-conducting state, the resistance value between point H and ground G becomes infinite ((X)), and if the voltage at point H is V□, it becomes ζVcc.

On the other hand, when the values of the resistor R1 and the power supply VCC are set so that the voltages v and I are 1v or less when the pair of electrodes 2a and 2b are immersed in cleaning liquid or hot water, the IC, When the device is similar to the one shown in the figure, the output terminal Q
, becomes high (H), that is, becomes non-conductive. Then, if the output of the output terminal Q is connected to a solid state relay (hereinafter referred to as SSR), etc., and the SSR is configured to control the hot water supply valve 5, the SSR is turned off when the electrode is immersed in cleaning liquid or hot water. The hot water supply (water supply) will be stopped.

When the level of the cleaning liquid or hot water in the cleaning tank 1 falls and the pair of electrodes 2a and 2b come out on top of the hot water, the output terminal Q becomes low (L), the SSR is turned on, and the hot water supply valve 5 is opened to supply hot water ( Water supply) is carried out, so the water level in tank 1 is kept constant.

Note that the pair of electrodes 2a and 2b used in the present invention corrode and wear out when immersed in a cleaning solution, so they are required to be inexpensive. As this pair of electrodes, for example, as shown in FIG. 7, screws 6a and 6b made of a conductive material are provided at a distance from each other on a part of the side wall surface of the cleaning tank 1. An O-ring 7, an insulating seat 8, and a seal washer 9 are fitted on the inner wall side of 6a and 6b to obtain insulation and waterproof effects, and on the other hand, on the outer wall side of Neshiro a and 6b, screws 6a and 6b are prevented from loosening. A spring washer lO and a nut 11 are fitted in to tighten the screw 6.
A and 6b are screwed together and are in a stopped state.

(Effects of the Invention) As described above, according to the dishwashing device according to the present invention, in the dishwashing device equipped with a sensor that measures the detergent concentration and water level of a cleaning tank that stores cleaning liquid, hot water, etc., the sensor Equipped with a pair of electrodes, a detection circuit detects the voltage change based on the resistance value of the cleaning liquid between the pair of electrodes, and based on this detection signal, the detergent concentration and water level of the cleaning liquid are measured, and the detergent concentration and water level are determined according to the preset standard concentration. A detection signal is input to the IC circuit that inputs the water level and compared, and the solvent concentration and water level are controlled based on this comparison value, so the detergent concentration and water level can be detected with a set of sensors. It can also be used as a water level gauge. Therefore, the number of component parts is reduced and there are no mechanically moving parts, and a sensor that is inexpensive and has few failures can be constructed, and by providing this sensor, it is possible to prevent the occurrence of failures.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a concentration meter and water level meter that shows an embodiment of the present invention, Fig. 2 is a block diagram showing an IC circuit of a detection circuit used in the present invention, and Fig. Characteristic diagram showing the relationship between the weight ratio of detergent and the voltage at point L, No. 4
Figures 5 and 5 are improved circuit diagrams of the detection circuit, Figure 6 is a circuit diagram of a water level meter, Part 7 is an explanatory diagram showing an example of a pair of electrodes used in the present invention, and Figures 8 (A) and (B). ) is a diagram showing a conventional float sensor, (A) is an overall perspective view, (
B) Figure is a sectional view showing a float switch, No. 9 [1J (
A). (B) is a diagram showing a conventional pressure sensor, and (A)
is a front view, and figure (B) is a cross-sectional view. 1...Cleaning tank 2...Pair of electrodes 3...Detection circuit 4...IC circuit 5...Hot water valve R1, R2, Rz, R4...Resistor VR...Variable resistor IC+, ICz, ICs...Linear level indicator element SSR...Solid state relay C...Capacitor D...Zener diode T...Thermistor Patent applicant Japan Electronics Co., Ltd. Figure 1 Figure 2 Figure 6 Figure 3 Weight ratio of water shortage and injection line Figure 4 Figure 5 Figure 7 Figure 8 (A)

Claims (1)

[Claims] In a dishwashing device equipped with a sensor that measures detergent concentration and water level in a cleaning tank containing cleaning liquid, hot water, etc., the sensor is equipped with a pair of electrodes, and the sensor detects a voltage change based on the resistance value of the cleaning liquid between the pair of electrodes. The detection circuit detects the detergent concentration and water level of the cleaning liquid based on this detection signal.The detection signal is input to an IC circuit that has input the preset reference concentration and reference water level for comparison.Based on this comparison value. A dishwashing device characterized by controlling solvent concentration and water level.