JP2523752B2 - Dishwasher - Google Patents

Description

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

2. Description of the Related Art A conventional dishwasher of this type is as shown in FIG.

That is, 1 is a cleaning tank for cleaning the object to be cleaned 2, which is supplied with water by controlling the water supply valve 7. Further, in the cleaning tank 1, an injection nozzle 4 which is rotated by hydraulic power sent by a pressurized water supply device such as a pump 3 is provided,
The cleaning liquid is sprayed from the small holes of the nozzle 4 to clean the object to be cleaned 2. The cleaning liquid used for this cleaning is the cleaning tank 2
It is heated by the heater 4 arranged at the bottom of the. The high-temperature cleaning liquid improves the cleaning performance of the object to be cleaned 2, and the heater 4 is also baked to dry the object to be cleaned. Further, the temperature detecting element 6 is also disposed at the bottom of the cleaning tank 2, and the control device 8 for detecting the temperature of the cleaning liquid or the temperature during drying inputs the detected temperature to control the temperature of the cleaning liquid during cleaning. Alternatively, the temperature inside the cleaning tank 2 at the time of drying is controlled to perform cleaning and drying suitable for the object to be cleaned 2 and to operate safely.

However, in the conventional configuration, the same cleaning is performed regardless of the type and amount of the object to be cleaned 2. Therefore, even if the amount is small, only the same operation as when fully set is performed. There was a lot of waste because it was used more than necessary in terms of the amount of electricity. Further, in a washing program for a small amount of washing and a dishwasher having several stages of drying time, the user must make a judgment and make a selection, which is troublesome.
In particular, in the drying process having a set time of several stages, when the amount of the object to be cleaned 2 is small, if the drying is performed for a long time, the amount of electricity is wasted, and the amount of the object to be cleaned 2 is large. In some cases, a short drying time does not allow sufficient drying.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a dishwasher that automatically determines the amount of an object to be washed and performs an operation suitable for the amount.

Means for Solving the Problems And in order to achieve the above object, the present invention provides a cleaning tank for storing dishes, an injection nozzle and a heater provided in the cleaning tank, and a water temperature in the cleaning tank in the cleaning process. Temperature detecting means for detecting the temperature change rate, temperature change rate detecting means for calculating the temperature change rate from the temperature detecting means, determining means for determining the amount of tableware based on the signal from the temperature change rate detecting means, and this determining means. It is provided with a control device for controlling the time of the washing, rinsing and drying processes according to the judgment of.

Action The action of this technical means is as follows.

That is, the cleaning water is heated by the heater during the cleaning process, and the temperature rises. When a certain amount of water is obtained by the water level detection device, the temperature rise of the wash water varies depending on the amount of the object to be washed. That is, when there are many objects to be cleaned, a large amount of heat is required due to its heat capacity, and the temperature change per unit time of the cleaning water is small, and conversely, when there are few objects to be cleaned, the temperature change is large. . Therefore, the amount of the object to be cleaned can be determined by measuring this temperature change.

EXAMPLE An example of the present invention will be described below with reference to FIGS. The basic structure of the dishwasher of the present invention is the same as the structure shown in FIG. 4, and the same parts are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 1, the temperature change rate detecting means 10 calculates the temperature change rate during the cleaning process (heaters are turned on simultaneously) based on the output signal from the temperature detection element 6. The determination means 11 determines the amount of the object to be cleaned based on the temperature change rate, and based on the determination result, the control device 8 determines each process time of cleaning, rinsing, and drying, and the heater 4, the cleaning pump 3, and the respective loads. Water valve 7
Control.

The relationship between the amount of the stored tableware 2 and the heat load will be described with reference to FIG. When the heating time is plotted on the horizontal axis and the washing water temperature is plotted on the vertical axis, the time required to raise the temperature varies depending on the heat capacity of the stored tableware 2. Naturally, the larger the heat capacity, that is, the heat load, the longer it takes. For example, in the dishwasher with the configuration shown in FIG. 4, if the input of the heater 5 is 1 kW and the thermal efficiency is 75 to 80%, the washing water temperature of 2.520 ° C is 60%.
Until the temperature reaches ℃, the temperature of the washing water rises in about 9 minutes in the case of no dishes [hereinafter, the item to be washed 2 is referred to as dish], about 11 minutes for 2 kg of dishes and about 14 minutes for 6 kg of dishes. Time changes.

Similarly, FIG. 3 also shows the heating time on the horizontal axis and the cleaning water temperature on the vertical axis, and shows the difference in the rate of change of the cleaning water temperature. That is, the change amount Δt of the wash water temperature at an arbitrary time Δt
Are Δt ₀ without tableware, ΔT _A with small tableware weight, ΔT _B with large tableware weight, and these are ΔT ₀ <ΔT _A <ΔT _B. That is, as the tableware weight increases, that is, the heat capacity (heat load) of the tableware increases, the rate of change in the wash water temperature per unit time (ΔT / Δ
t) becomes smaller, and the slope of the line representing the temperature rise in the figure becomes smaller.

From the above, the heat load of the tableware, that is, the amount of stored tableware can be detected by the heat load detection device including the temperature detection element 6 and the temperature change rate detector 7.

In order to measure the change amount ΔT of the wash water temperature at an arbitrary time Δt and divide the heat capacity of the tableware into a plurality of stages (three stages as an example), the reference ΔT is ΔT ₁ , ΔT ₂ (ΔT ₁ > ΔT ₂ ). Then, when ΔT> ΔT ₁ , the amount of tableware is small, when ΔT ₁ <ΔT ₂ , the amount of tableware is large, and when ΔT ₁ >ΔT> ΔT ₂ , the amount of tableware is intermediate. it can. Based on this judgment
A detection signal is sent from the heat load detection device 7 to the control device 8, where the washing time and the drying time are determined and the dishwasher is operated. That is, depending on the amount of tableware, when the amount is small, the time for the washing process and the drying process is short, and when the amount for the tableware is large, the time is extended to reliably perform the cleaning and drying.

As can be seen from the above example, by using the temperature detecting element 6 that has been conventionally used, it is possible to easily detect the amount of stored tableware,
Based on this, the time of the operation process and the drying process can be set, so that the performance is reliable and the operation is less wasteful, which is advantageous in terms of energy.

In the present embodiment, the amount of the object to be cleaned is determined during the cleaning step, but when only the drying step is performed, the amount of the object to be cleaned may be determined based on the temperature change rate in the initial stage of the drying step.

EFFECTS OF THE INVENTION As is clear from the above examples, the dishwasher of the present invention detects the amount of articles to be washed such as dishes placed in the washing tank,
As a result, it is possible to arbitrarily control the time of the washing process and the drying process, so that when the amount of dishes is small, it is possible to operate efficiently without performing washing or drying with more loss than necessary,
It saves energy. Also, in terms of performance, reliable cleaning performance and drying performance can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of a dishwasher according to an embodiment of the present invention, FIGS. 2 and 3 are relationship diagrams of heating time and washing water temperature, and FIG. 4 is a sectional view of a conventional dishwasher. 1 ... Cleaning tank, 2 ... Object to be cleaned, 3 ... Cleaning pump, 4
...... Washing nozzle, 5 …… Heater, 6 …… Temperature detection element,
8 ... Control device, 10 ... Temperature change rate detecting means, 11 ... Judging means.

Claims (1)

(57) [Claims] 1. A washing tank for storing dishes, an injection nozzle and a heater provided in the washing tank, a temperature detecting means for detecting the water temperature in the washing tank in the washing process, and a temperature from the temperature detecting means. Temperature change rate detecting means for calculating the change amount, determining means for determining the amount of tableware based on the signal of the temperature change rate detecting means, and the time of the washing / rinsing / drying process is controlled by the determination of this determining means. Dishwasher with control.