JPH05115416A - Tableware washing machine - Google Patents

Abstract

PURPOSE:To easily and exactly detect an atmospheric temperature in the course of a washing process without exposing a temperature detecting part to the outside of the machine by providing the temperature detecting part in an air path extending from a cooling suction port to a cooling fan. CONSTITUTION:When a washing process is started, washing water is heated by a heater, and a detection temperature of a first thermistor attached to a low part of a washing tank rises. On the other hand, when a motor 6 for driving a washing pump 4 operates, cooling air flows in from a cooling suction port 14 by a cooling fan 5 and blows against the motor 6, and thereafter, is exhausted from a cooling exhaust port 19. In this case, a second thermistor 17 inserted and held by a supporting part 18 protruding from the cooling suction port 14 is also exposed to cooling air, but an atmosphere in a frame 7 rises in its temperature due to heat radiation from washing water, and by being influenced thereby, a detection temperature of a second thermistor 17 rises. In this case, in a regular washing process, a detection temperature of a second thermistor 17 shows a value correlated to an atmospheric temperature in the periphery of the tableware washing machine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dishwasher for washing dishes.

[0002]

2. Description of the Related Art Recently, there has been proposed a dishwasher which simply judges the capacity of the dish put in the dishwasher and accordingly controls the operating time more finely.

A conventional dishwasher will be described below. FIG. 7 shows a sectional view of a conventional dishwasher. In FIG. 7, 1 is a washing tank for accommodating dishes 2 inside and storing washing water at the bottom, 3 is a washing nozzle that is rotatably supported and ejects washing water toward the dishes 2, 4 is the washing water The washing pump 4 is a washing pump for feeding the nozzle 3, and the washing pump 4 is driven by a motor 6 having a cooling fan 5 at the rear portion. Reference numeral 7 is an underframe supporting the cleaning tank 1, and 8 is a heater arranged at the bottom of the cleaning tank 1 for heating cleaning water. Reference numeral 9 denotes a thermistor which is attached to the bottom of the cleaning tank 1 so as to be in close contact with the outside. Reference numeral 10 denotes a blower fan that sends outside air into the cleaning tank 1, and the air inside the cleaning tank 1 is exhausted to the outside of the machine through an exhaust port 11.

The operation of the dishwasher having the above structure will be described below. User tableware 2
When the operation is started after arranging in the basket 12 and storing it in the cleaning tank 1 and putting the detergent therein, first, a predetermined amount of tap water is supplied to the bottom of the cleaning tank 1. Then, the motor 6 and the heater 8 are energized, and the washing water is jetted from the washing nozzle 3 toward the dishes 2 by the washing pump 4 while being heated. At this time, the temperature of the washing water is detected by the thermistor 9 and the control unit 1
3 always grasps the temperature of the washing water. When the temperature of the cleaning water reaches a predetermined temperature and a predetermined time has elapsed from the start of cleaning, the control unit 13 ends the cleaning process and once drains the cleaning water. Next, tap water is newly supplied, and the same operation as the above-described cleaning step is performed for several minutes to drain the water. After repeating this rinsing step several times, the same operation as the washing step called a heat rinsing step is performed, and when the predetermined temperature is reached, the operation is finished and drained. Finally, the blower fan 10 is operated to wash the cleaning tank 1.
The steam inside is discharged to the outside of the machine, and at the same time, the heater 8 is intermittently energized to heat the tableware 2 to dry the attached water droplets.

In detecting the capacity of the tableware, the degree of temperature rise of the washing water in the washing step is examined, and the operating time of each step of washing, rinsing and drying is changed according to the degree. .. That is, when the input value of the heater 8 is constant and the tableware capacity is small, the heat capacity is reduced accordingly, and the temperature of the wash water rises quickly as shown in FIG. Actually, the control unit 13 measures the time dt during which the temperature detected by the thermistor 9 rises from T1 to T2, and tries to determine the capacity of the tableware based on this time dt. Generally, when the tableware capacity is small, the washing water ejected from the washing nozzle 3 often hits the tableware, so that the dishes can be washed well. The same can be said for drying, and conversely, if the operating time is shortened by that amount, it is possible to always obtain a certain washing performance and drying performance regardless of the tableware capacity, and at the same time save energy and save time. is there.

[0006]

However, in the above-mentioned conventional structure, the temperature rise time of the washing water is influenced by the ambient temperature of the environment where the dishwasher is installed, and for example, summer (35 degrees) and winter (5 degrees). ) And, there is a difference of 3 minutes or more in raising the temperature of the washing water by 20 degrees. Since this difference is larger than the temperature rise time difference due to the tableware capacity difference, it was necessary to positively detect the ambient temperature and correct the temperature rise time dt accordingly. Then, there is a thermistor 9 as a means for detecting the ambient temperature around which the dishwasher is installed, and it is conceivable that the temperature detected by the thermistor 9 immediately before the start of operation is the ambient temperature. Since the thermistor 9 reaches around 90 degrees at the end, the temperature of the thermistor 9 does not drop to the ambient temperature until a few hours elapse, and the ambient temperature cannot be accurately detected in a home used several times a day. Was.

The present invention is intended to solve the above-mentioned conventional problems, and provides a dishwasher having means for accurately detecting the ambient temperature during the washing process without exposing the temperature detecting portion to the outside of the machine. This is the first purpose.

A second object is to stably measure the ambient temperature under all conditions of use of the dishwasher.

A third object is to correct the temperature rise time with respect to the ambient temperature very easily to accurately detect the capacity of the tableware.

[0010]

In order to achieve the first object, the dishwasher of the present invention has a conventional first temperature detector for measuring the water temperature of washing water, and a cooling motor for driving a washing pump. The second temperature detection unit is arranged in the air path that flows in from the outside of the dishwasher by the fan.

In order to achieve the second object, in the dishwasher of the present invention, after the motor starts to operate, the water temperature measured by the first temperature detector reaches the predetermined temperature, and the second time is reached when the predetermined time elapses. The ambient temperature in which the dishwasher is placed is determined based on the temperature measured by the temperature detector.

Further, in order to achieve the third object, the dishwasher of the present invention is characterized in that the temperature rise time in a predetermined temperature section measured by the first temperature detection unit during the washing process is different from the second time.
The correction time value corresponding to the difference between the ambient temperature and the standard state by the temperature detection unit is adjusted, and the tableware capacity is determined based on the temperature rise time after the correction.

[0013]

With this configuration, during the cleaning process, the cooling fan is rotated by the motor to suck air from the outside of the machine to cool the motor. The second fan placed in the air path leading to the cooling fan. Since the temperature detector is exposed to the cooling air from the outside air, it is affected by the temperature rise of the wash water, but the temperature detected by the second temperature detector during the normal washing process correlated with the ambient temperature around the dishwasher. Indicates the value,
It is possible to estimate a value close to the ambient temperature.

Further, the temperature inside the machine body immediately after using the dishwasher is high, and when the cooling fan of the motor is stopped, the temperature detected by the second temperature detection unit rises considerably. Therefore, when operating continuously, the temperature detected by the second temperature detection unit decreases and approaches the ambient temperature, and conversely, when tap water of low water temperature is supplied, it rises and approaches the ambient temperature. A difference occurs in the detected temperature of. Since the latter requires time for the cleaning water temperature to reach the predetermined temperature in the cleaning step, the detection of the ambient temperature by the second temperature detection unit is not uniformly obtained in the time after the start of operation, and If the condition that the temperature detected by the temperature detector 1 has reached a predetermined temperature is added as a condition, the difference in the temperature detected can be reduced especially when water is supplied at low ambient temperature and low water temperature.

Furthermore, there is an inverse relationship between the ambient temperature of the dishwasher and the temperature rise time of the wash water, and the linear gradient is the same regardless of the dish capacity. Therefore,
If the temperature rise time difference between the ambient temperature of any ambient temperature and the standard state is predetermined as a correction value, and the correction value is added to or subtracted from the temperature rise time according to the difference between the measured ambient temperature and the standard state, The capacity of the tableware can be determined uniformly by the temperature rise time at the standard ambient temperature.

[0016]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

Since the whole structure is almost the same as the conventional one, a sectional view showing the whole structure is shown in FIG. 6, and FIG. 1 is a fragmentary perspective view of the present invention. The same members as those in the conventional example are designated by the same symbols.

In FIG. 1, 14 is a cooling intake port provided at the rear portion of the underframe 7, and 15 is a guide rib for guiding the cooling air from the cooling intake port 14 to the cooling fan 5 of the motor 6 through which the cooling air flows. 16 is formed. Reference numeral 17 denotes a second thermistor which is sandwiched by a substantially U-shaped support portion 18 which projects from the cooling intake port 14.

The operation of the above configuration will be described.
Although the basic operation of the dishwasher is the same as that of the conventional example, the detection temperatures of the first thermistor 9 and the second thermistor 17 that detect the temperature of the cleaning water in the cleaning tank 1 are normally as shown in FIG.
Before the start of operation, it almost matches the ambient temperature where the dishwasher is placed. When the cleaning process is started, the cleaning water is heated by the heater 8 and the temperature detected by the first thermistor 9 rises. On the other hand, when the motor 6 that drives the washing pump 4 operates, the cooling air flows from the cooling fan 5 through the cooling intake port 14 and hits the motor 6 before being discharged from the cooling exhaust port 19. At this time, the second thermistor 17 also cools. Although exposed to the wind, the temperature in the atmosphere inside the underframe 7 rises due to heat radiation from the wash water, and the temperature detected by the second thermistor 17 is affected by this and rises as the temperature of the wash water rises as shown in FIG. To do. However, when the detection temperature Ta of the second thermistor 17 at the time ta after the start of operation is taken, the detection temperature Ta and the ambient temperature around the dishwasher have a correlation as shown in FIG. The ambient temperature can be detected.

(Embodiment 2) Further, when the dishwasher is operated in two times due to a large amount of dishes, the dishwasher is warmed immediately after being used once, as shown in FIG. In addition, the temperatures detected by the first thermistor 9 and the second thermistor 17 before the start of operation are both high. In particular, when used for hot water supply, the temperature of the washing water remains high from the beginning, but the temperature detected by the second thermistor 17 gradually decreases after the washing operation starts, and stabilizes after 10 minutes. Conversely, when low-temperature water is supplied, the temperature detected by the second thermistor 17 also rises as the washing water temperature rises, as shown in FIG.

Here, the ambient temperature is detected by the temperature detected by the second thermistor 17 after the first thermistor 9 reaches the temperature controlled temperature (57 degrees) during the cleaning process and after a predetermined time has elapsed (10 minutes) after starting the operation. By determining the above, the ambient temperature can be accurately detected even under the various use conditions as described above.

(Embodiment 3) Furthermore, since the ambient temperature and the temperature rise time of the cleaning water are inversely proportional and the ambient temperature and the detection temperature of the second thermistor 17 correspond one-to-one, as shown in FIG. The temperature rising time dt from the temperature T1 to the temperature T2 is inversely proportional to the detected temperature Ta, and the slope of the straight line is constant regardless of the capacity of the tableware. Then, if the ambient temperature of 20 degrees is set to the standard state and the temperature rise time difference a between the detected temperature of the second thermistor 17 and the standard state is added to the measured temperature rise time (dt1, dt2), all the temperature rise times in the standard state. It can be replaced with (dt1 + a, dt2 + a), and the capacity of the tableware can be detected with a uniform reference. In the present embodiment, the temperature detection unit is placed in the cooling air path leading to the washing pump to determine the ambient temperature around the dishwasher, but the ambient temperature detection means is not limited to this.

[0023]

As described above, the present invention comprises a motor having a cooling fan for driving a washing pump section, and a first temperature detecting section for measuring the water temperature of washing water. By arranging the second temperature detection unit in the air path flowing from the outside of the machine, the ambient temperature can be easily and accurately detected during the cleaning process without exposing the temperature detection unit to the outside of the machine.

Further, the dishwasher is placed on the basis of the measured temperature of the second temperature detecting unit at the time when the measured water temperature of the first temperature detecting unit reaches the predetermined temperature and the predetermined time elapses after the motor starts operating. By determining the ambient temperature, the ambient temperature can be detected extremely accurately under all operating conditions.

Further, a correction time value corresponding to the difference between the ambient temperature and the standard state by the second temperature detector is adjusted with respect to the temperature rise time in the predetermined temperature section measured by the first temperature detector during the cleaning process. However, by judging the tableware capacity based on the temperature rise time after the correction, the correction with respect to the ambient temperature becomes extremely easy, and at the same time, the judgment standard of the tableware capacity becomes uniform and simplification is achieved.

[Brief description of drawings]

FIG. 1 is a fragmentary perspective view of a first embodiment of a dishwasher according to the present invention.

FIG. 2 is a graph showing changes in the detected temperature of the dishwasher of the present invention.

FIG. 3 is a graph showing the relationship between the detected temperature and the ambient temperature.

FIG. 4 is a graph showing changes in detected temperature during continuous hot water supply operation.

FIG. 5 is a graph showing changes in detected temperature during low-temperature water supply operation.

FIG. 6 is a graph showing the relationship between the detected temperature and the temperature rise time.

FIG. 7 is a cross-sectional view of a conventional dishwasher

FIG. 8 is a graph showing how the temperature of washing water rises.

[Explanation of symbols]

 1 Cleaning Tank 5 Cooling Fan 6 Motor 7 Underframe 8 Heater 9 First Thermistor 14 Cooling Intake Port 16 Air Path 17 Second Thermistor

Front page continued (72) Inventor Wataru Hamaguchi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. A washing tank for storing dishes, a washing nozzle for ejecting washing water toward the dishes, a washing pump unit for feeding the washing water accumulated in the washing tank to the washing nozzle, and a cooling fan. A motor for driving the washing pump unit, a heater for heating the washing water, and a first temperature detecting unit for measuring the temperature of the washing water, the air path flowing from outside the dishwasher by the cooling fan A dishwasher with a second temperature detector installed in the. 2. The dishwasher is placed on the basis of the measured temperature of the second temperature detection unit at the time when the measured water temperature of the first temperature detection unit reaches a predetermined temperature and a predetermined time has elapsed after the motor started to operate. The dishwasher of claim 1, wherein the ambient temperature is determined. 3. A predetermined temperature measured by the first temperature detection unit, comprising a first temperature detection unit for measuring the water temperature of the wash water and a second temperature detection unit for measuring the ambient temperature around the dishwasher. A dishwasher in which the correction time value corresponding to the difference between the ambient temperature and the standard state by the second temperature detection unit is adjusted with respect to the temperature rise time in the section, and the dish capacity is determined based on the corrected temperature rise time.