JP2515420B2 - Tableware dryer - Google Patents

Description

The present invention relates to a dish dryer and a dishwasher having a drying function.

[Prior Art] In a dishwasher and a dishwasher equipped with a drying function,
Drying operation is achieved by circulating hot air heated by a heater in a drying chamber containing dishes.

If the hot air circulation time is appropriate, the tableware is sufficiently dried, but if it is too short, sufficient drying cannot be obtained. Also, if it is too long, although it is dried, extra energy is wasted and extra waiting time is brought about.

The time during which hot air circulates, that is, the drying operation time is an important factor as described above, but in the conventional apparatus, this time is set by a timer that can be freely changed by the user.

In the above dishwasher, when the type and amount of dishes are the same each time, the user remembers an appropriate time in general,
You can operate it with the timer scale on it, but in reality, the type and amount of tableware handled is usually different every time, and if the amount of tableware is small or only tableware such as a ceramic plate that drains well is used. , If you don't set it to a little short, you will waste extra energy. There is a problem that the water remains on the tableware.

In this way, proper setting of the above timer requires skill, so to speak, such as experience and intuition, and even if it improves, it tends to be a user's tendency to keep the water remaining, so the timer setting must be long. The waste of electric energy accumulated during long-term use was considerably large.

Therefore, recently, by mounting a humidity sensor in the drying chamber and ending the drying process based on the comparison between the humidity value detected by this humidity sensor and a preset value, the above-mentioned problems are solved. A dryer has been proposed (for example, JP-A-63-11129 and JP-A-1-26593).
No. 2, etc.).

[Problems to be Solved by the Invention]

According to the above-mentioned conventional technique using the humidity sensor, the drying process is finished when the humidity in the drying chamber reaches a set value, so that there is an advantage that the drying time can be appropriately controlled.

However, in the above-mentioned conventional technique, since the dryness is not configured to be selectable in a plurality of stages, there is a problem that the user cannot arbitrarily select the dryness. Further, even if a configuration in which the degree of dryness can be selected is added to the above-mentioned conventional technique, since the heat capacity of the heater is constant, the drying time varies depending on the selected degree of dryness. For example, when the dryness degree is set to "strong", the drying time becomes long, and when the dryness degree is set to "weak", the drying time becomes short. In this way, if the drying time varies depending on the selected degree of drying, it is not possible for the user to predict when the drying process will end when he / she wants to use the tableware immediately after drying, and the setup will be poor. Was becoming.

The present invention was devised to solve the above problems,
The first purpose thereof is to provide a tableware dryer capable of keeping the drying time substantially constant regardless of the degree of drying selected. In addition, the second purpose is to ensure that the drying process is completed even if the reference value for comparison with the detected humidity value is not set beforehand when the drying process is terminated based on the humidity value detected by the humidity sensor. It is to provide a tableware dryer that can detect the end.

[Means for solving the problem]

In order to solve the above problems, the tableware dryer according to claim 1 of the present invention is a humidity sensor for detecting the humidity of a drying chamber,
A heater for sending hot air into the drying chamber, a selection switch for selecting a drying degree indicated by a humidity value in a plurality of stages, and a switching means for switching the heat generation amount of the heater according to the selection of the drying degree by the selection switch. And a stop control means for stopping the heating of the heater when the humidity value detected by the humidity sensor reaches the degree of dryness selected by the selection switch.

Further, in the tableware dryer according to claim 2 of the present invention, in the above structure, the stop control means differentiates the humidity value detected by the humidity sensor with respect to time, and the differential value from the differentiation means. Based on the history of, the drying curve determining means stops the heating of the heater when the differential value once changes from small to large and then changes to small again.

[Action]

 The operation of the tableware dryer according to claim 1 will be described.

The heating value of the heater is switched according to the selection of the dryness degree by the selection switch. For example, the degree of dryness is "weak"
When is selected, the heating value of the heater is set to the lowest normal heating value, and when “strong” is selected as the degree of dryness, the heating value of the heater is increased accordingly. Thereby, the drying time (the time from the start of drying to the end of drying) can be maintained at a substantially constant time regardless of the degree of drying selected. In such a heater heating state, the stop control means stops the heating of the heater when the humidity value detected by the humidity sensor reaches the dryness degree selected by the selection switch.

 The operation of the tableware dryer according to claim 2 will be described.

The rate of change of the drying curve is calculated by the differentiating means, the saturation state of the degree of decrease in humidity is detected by the drying curve determining means, and heating of the heater is stopped. That is, the end of drying can be reliably detected without providing a reference value for comparison with the humidity value detected by the humidity sensor in advance.

[Embodiment] An embodiment in which the present invention is applied to a dishwasher (hereinafter referred to as a dishwasher) will be described below with reference to the drawings.

FIG. 1 is a cross-sectional side view of the dishwasher of this embodiment, and a synthetic resin main body case (2) integrally forming a cleaning tank (1).
A lid cover (5) which is an upper lid forming a door is extended by a single plate-shaped body having lattice-shaped projections (4) on both the rear side and the left and right sides, and the washing tank (1) and Each cover (3)
A rectangular box type washing chamber (drying chamber) (6) is formed by (5), and the lid cover (5) is made openable and closable around the support shaft portion (7) at the rear end edge of the upper surface. The shelf-like body (9) for storing dishes is installed through the guide rails (8) on both sides of (1).

Also, open the water inlet (10) at the bottom of the cleaning tank (1),
A water supply vibe (12) having a water supply solenoid (11) is provided at the water supply port (10), and a water supply hose (13) communicating with water supply is connected to the water supply port (10) via the valve (12). (12) is opened and closed to supply an appropriate amount of water into the cleaning tank (1).

Further, a water storage tank (14) is formed at the bottom of the washing tank (1), and a water intake case (15) is fixed to the bottom of the tank (14) to prevent the tank (14) and the water intake case (15) from swirling. The tank (14) has a heater (17) installed therein, and a drawer (19) which is retracted by a spring (18) is attached to the tank (14) so that the dust filter (20) is removable. ) Is placed on the drawer base (19), and a dust filter (20) is attached to the upper surface of the tank (14) so that the dust filter (20) can be freely inserted and removed to collect dust such as food waste.

In addition, a hollow water transfer shaft (2
1) is fixedly installed, a fountain vane (23) having a plurality of jet nozzles (22) ... Is rotatably attached to the upper end of the water guide shaft (21), and a water feed pump (25 having a water feed vane (24) is built in. ) Is installed on the lower surface side of the bottom of the cleaning tank (1), the forward rotation discharge port (26) of the pump (25) is connected to the lower end of the water guide shaft (21), and the reverse rotation discharge port of the pump (25) ( The drainage pipe (28) is connected to 27), and the drainage hose (29) communicating with the sewer is connected to the drainage pipe (28) via the check valve body (30) and the secondary side drainage pipe (31). On the other hand, the water supply pipe (3
2) is connected to the water absorption side of the water pump (25),
The water in the tank (14) is forwarded from the forward rotation outlet (26) into the cleaning chamber (6) through the injection nozzle (22) by the forward rotation of the water pump (25), while the water pump (25) is rotated in reverse. The water in the tank (14) is discharged to the sewer through the reverse outlet (27).

Further, a control box (33) is attached to the front side of the body case (2), and a switch group (37) such as a start switch (34), a stop switch (35) and a door opening switch (36) is arranged. There is.

That is, the water is washed by the forward rotation of the water pump (25) to wash tank (1) → dust filter (20) → tank (14) → water absorption pipe (32) → pump (25) → injection nozzle (22) → washing tank. By forming the circulation of (1), the water flows through the path of the washing tank (1) → tank (14) → water absorption pipe (32) → pump (25) → drain hose (29) by reversing the water pump (25). Exhausted through.

(43) is a stopper pin fitted in the opening of the slidable dust filter (20), (45) is a solenoid for advancing and retracting it, and (46) and (47) are for confirming the position of the dust filter (20). For the detection piece and the detection switch.

Then, after the water in the tank (14) is discharged through the course, the heater (17) is heated and the water supply blade (24) is rotated in the forward direction, so that the hot air heated by the heater (17) is ejected from the jet nozzle. The dishes are sent from (22) into the drying chamber (6) to dry the dishes.

When the heater (17) is heated during the circulation of the water, the circulating water becomes warm water, and when the heater (17) is heated, the circulating water becomes cold water.

The switching of the above operation is controlled by the microcomputer (48) in the control box (33).

A humidity sensor (50) is attached to the upper part of the drying chamber (6) according to the present invention, and humidity information from the sensor (50) is taken in the microcomputer (48) to perform the above-mentioned operation. Means for reflecting the control are provided.

That is, the humidity sensor (50) of this example uses a ceramic humidity sensor (50) based on a porous sintered body of metal oxide mainly composed of Al ₂ O ₃ , and is directly exposed to washing water. It is fixed in the drying chamber (6) by covering it with a cover (51) equipped with a very fine perforated plate or labyrinth so that it does not exist. (51a) is a drain hole provided at the bottom of the cover.

In this humidity sensor (50), the amount of desorption of water molecules on the surface changes depending on the amount of vapor in the atmosphere, and the electric resistance changes exponentially.

The humidity sensor (50) may be various other ones, and the mounting method is not limited to the above example. For example, the humidity sensor (50) may be provided outside with a cover (3) forming the wall of the drying chamber (6) being separated. The cover (3) at the mounting portion may be a perforated plate or a gas permeable plate that allows the atmosphere to freely flow in and out, although the washing water with labyrinth is not directly applied.

Next, the structure of the microcomputer (48) and the connection with each sensor will be described together with the operation of the dishwasher.

That is, a microcomputer (hereinafter referred to as a microcomputer) (48) has a power supply section (52), a display section (53), a switch group (37), a water level sensor (54), a temperature sensor (55), as shown in the second illustration. A humidity sensor (50), a motor (56), a valve group (57), the heater (17), etc. are connected, and a display section (53) is an LED, LCD, etc. fixed to the front panel of the control box (33). The water level sensor (54) consists of a plurality of electrodes (58) provided on the side surface of the cleaning tank (1),
The temperature sensor (55) is composed of a thermostat, a thermocouple, etc., the detection end of which projects into the tank (14) so as to measure the water temperature in the tank (14).

In addition to the circuit for normal operation control of the dishwasher in the microcomputer (48), as shown in FIG. 3, a reference humidity storage means (60) and a desired degree of drying input by the user. A humidity sensor which takes in a humidity as a reference for stopping the drying operation in accordance with the above, and a humidity value y from the reference humidity memory (60) or the set humidity memory (61). The comparing means (62) for comparing with the humidity value x from (50), and the drying operation stopping means (63) which operates when the humidity value x of the latter becomes smaller than the former y in this comparing means (62). ) And, and acts as follows.

In this embodiment, the reference humidity storing means (60), the comparing means (62) and the drying operation stopping means (63) constitute a drying operation stop control means.

That is, as shown in the flowchart of FIG. 5, the general operation is switched to the normal mode when the power switch is turned on after the power is turned on. In this normal mode, the user selects a desired operation course to wash the dishes in the washing room (6 ), And switch in the desired degree of dryness to be described in detail later. Then, when the full course of washing, rinsing, and drying course is selected by the above operation course selection, next, the washing mode → rinsing mode 1 → rinsing mode 2 → heating rinsing proceeds, and the judgment step of the drying course is also Yes. Then, the dry operation is executed, and finally all relays, switches, etc. are turned off in the "end mode" step, and the operation is finished.

In the washing mode, warm water circulates in the washing chamber (6) and the detergent is added, cold water circulates in the washing chamber (6) in the rinsing mode 1 and rinsing mode 2, and finally in the heating rinsing mode by circulating hot water. A rinse is performed.

Also, rinsing by selecting the driving course in the above normal mode,
When the dry course is selected, the washing mode is skipped and the operation is executed from the position shown in the flowchart in FIG.
When only the dry course is selected, the operation is executed from the position.

Next, the operation in the normal mode will be described with reference to the flowchart of FIG.

In the normal mode, the user has the switch group (37).
The above-mentioned operation course is selected by the inside course selection switch, and the door (cover) (5) is opened and closed to put the dishes in the washing room (6). 64) Press to set the set humidity to the desired value. This is the "dryness setting" step in FIG.

This set humidity is the humidity that is the standard for stopping the drying operation, and the selection switch (64) is set to "strong".
Assuming that it consists of three items, "medium" and "weak", for example, when the "strong" selection switch is pressed, 5% is set as the reference humidity, and when "medium", 10% and "weak" are set. In some cases 20
% Is set, and so on. Of course, the humidity value can be variously changed.

Then, after the above setting operation, when the user presses the start switch, it is first detected at this point whether the door (cover (5)) is open, and if the door remains open, it means that the door is open. Is notified by an alarm or the like, and if the door is closed, it is determined whether only the dry course is selected next. If only the dry course is selected, the process moves to the flowchart of FIG. 5, and if not only the dry course, the rinse course is selected. If Yes, the process moves to the flowchart of FIG. 5, and if No, it moves to the washing mode (“wash mode” step in the flowchart of FIG. 5).

Next, the operation in the dry mode will be described in detail based on the flowchart of FIG.

That is, when entering the dry mode, the microcomputer (48) immediately receives the current humidity information x from the humidity sensor (50) and always starts taking in new current humidity.

Then, the reference humidity input by the user in the "dryness setting" step of the normal mode is already LE
Although it is displayed as characters such as "strong dry" and "medium dry" on the display part (53) of D, LCD, etc., the humidity value according to this reference humidity is stored in the microcomputer in the "Set value y acquisition" step. Take in.

In the normal mode, if the user does not set the dryness or forgets to do so, the microcomputer (4
Since 8) cannot take in the reference humidity, in order to prevent this inconvenience, whether or not the set value has been input by the user in the next determination step, that is, whether or not the data has been input in the set-up area of the set value y. Judge, Ye
If it is s, the data y in the intake area is immediately compared with the current humidity data x in the next determination step, but if No, it is separately provided in the microcomputer and the manufacturer washes the dishwasher. The reference humidity data is fetched as the reference humidity value y from the reference humidity storage means (60) in which the reference humidity value is stored in advance, and is compared in the judging step.

The data in the reference humidity storage means (60) may be, for example, data in the setting storage means (61) when the user selects "medium" (for example, 10%), or other data. It may be standard data.

Then, in the next judgment step of "x>y", since Yes is normally established immediately after rinsing, the heater (17) is turned on,
This heater ON is repeated until Yes is satisfied in the next judgment step "x≤y". That is, the current humidity value x
Until the temperature becomes lower than the standard humidity value y
It keeps on.

When No is established in the judgment step “x ≦ y”, the heater (17) and the motor (56) are turned off and the drying operation is finished.

In addition, when the result of the determination step as to whether or not the set value is input is No and the reference humidity value is fetched from the reference humidity storage means (60), at the same time, "standard drying" or "display" is displayed on the display section (53). Display characters such as "Random dry".

FIG. 8 shows how the humidity in the drying chamber (6) changes due to the above operation.

In the graph of FIG. 8, the set value y ₁ is the case where the user selects “strong” by the selection switch (64), and similarly, the set value y ₂ is “medium” and y ₃ is “weak”. Is selected, and the end times t ₁ , t ₂ , and t ₃ are different for the same amount and type of tableware.

Therefore, in the present invention, the heat generation amount of the heater (17) can be switched according to the selection by the selection switch (64). In other words, by switching the amount of heat generated,
Since the curve itself of the above graph is deviated, the time required for drying is not so different from the case of selecting "weak" (t3 when selecting "strong" or "medium"). ) Can be shortened to for that reason,
For the user, regardless of the dryness selected
Since it is possible to predict the time when the drying will end, it is easy to carry out the subsequent setup.

As a method of switching the amount of heat generated by the heater (17), for example, the heater (17) may be two heaters of different wattages, and when "strong" is selected, both heaters are energized, When "Medium" is selected, one heater with a higher wattage is selected, and when "Weak" is selected, one heater with a smaller wattage is energized,
Alternatively, there is a method of changing the duty of the heater (17) to switch the heat generation amount.

In addition, the humidity change graph of the drying room (6) is roughly 8th.
Since the shape is as shown in the figure, by utilizing this property, the stop control means for the drying operation is not constituted by the reference humidity storage means (60), the comparison means (62) and the stop means (63), but by the following It can also be configured.

That is, as shown in FIG. 9, the humidity sensor (50)
Means for differentiating humidity information x from x with respect to time (70)
And, by taking the history of the differential value from this differentiating means (70),
It may be configured with a drying curve determining means (71) that triggers the drying operation stopping means (63) when the differential value changes from small to large and then to small again.

In this embodiment, the rate of change of the drying curve is calculated by the differentiating means (70), and the change rate of the drying curve is determined by the drying curve determining means (71).
This means that the portion A shown in the figure is detected.

Therefore, by this stop control means, it is possible to reliably detect that the degree of decrease in humidity has reached a saturated state without giving a special standard in advance, and it is always appropriate regardless of the humidity of the external environment due to changes in the four seasons. The operation can be stopped depending on the dryness.

Further, as the drying curve determination means (71), the drying operation stop means (63) is triggered by the arrival of a predetermined small value of the differential value after a predetermined time has elapsed since the drying operation was started. It may be allowed to.

[Effects of the Invention] Since the tableware dryer of the present invention is configured to switch the heat generation amount of the heater according to the selection of the drying degree by the selection switch, the drying time can be set to a substantially constant time regardless of the selected drying degree. Can be kept at Therefore, the user can roughly predict the time when the drying is finished, regardless of the selected degree of drying, which facilitates the subsequent setup. Further, the tableware dryer of the present invention is configured to calculate the rate of change of the drying curve by the differentiating means, detect the saturated state of the degree of decrease in humidity by the drying curve determining means, and stop the heating of the heater. It is possible to reliably detect the end of drying without providing a reference value for comparison with the humidity value detected by the humidity sensor in advance.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a dishwasher according to the present invention, FIG. 2 is a block diagram showing a connection between a microcomputer and other electric parts, FIG. 3 is a block diagram showing an internal configuration of the microcomputer, and FIG. The front view showing the appearance of the selection switch, FIGS. 5 to 7 are flow charts showing the operation and the user's operation, FIG. 8 is a graph showing the relationship between the drying process and the stopping operation, and FIG. 9 corresponds to claim 2. It is a block diagram in a microcomputer in an example. (6) …… drying room, (48) …… microcomputer, (50) …… humidity sensor, (60) …… reference humidity storage means, (61) ……
Set humidity storage means, (62) ... comparing means, (63) ... drying operation stopping means, (70) ... differentiating means, (71) ... drying curve judging means.

Claims (2)

(57) [Claims] 1. A humidity sensor for detecting humidity in a drying chamber,
A heater for sending hot air into the drying chamber, a selection switch for selecting a drying degree indicated by a humidity value in a plurality of stages, and a switching means for switching the heat generation amount of the heater according to the selection of the drying degree by the selection switch. And a stop control means for stopping the heating of the heater when the humidity value detected by the humidity sensor reaches the degree of dryness selected by the selection switch. 2. The stop control means, based on a differential means for differentiating the humidity value detected by the humidity sensor with respect to time, and the history of the differential value from the differentiating means, the differential value is changed from a small value to a large value. 2. The tableware dryer according to claim 1, further comprising a drying curve determining unit that stops heating of the heater when the temperature changes and then decreases again.