JP2012070856A - Dish washer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dish washer that is capable of efficiently generating steam used for a steam operation without the need for special parts or facilities, and is highly reliable and highly durable.SOLUTION: The dish washer includes: a washing tank D; a heater 9 that is disproportionately disposed at a position nearer to a water surface side of washing water which is at a reference water level L than to the bottom of the washing tank and heats the washing water accumulated in the washing tank; a pump 6 for squirting the washing water into the washing tank; a temperature detection means (thermistor) TH for detecting the temperature of the bottom of the washing tank which is a lower part of a region where the heater is disposed; and a season determination means. A washing operation for washing dishes by washing water is performed after the steam operation is performed that heats the washing water by the heater and generates steam within the washing tank. For output of the temperature detection means, a threshold value is set that serves as a reference for turning on/off electricity to the heater is during the steam operation, and a threshold value for the output of the temperature detection means is set in accordance with the output of the season detection means.

Description

  The present invention relates to a dishwasher, and more particularly, a dishwasher having a function of performing a steam operation for generating steam in a washing tank to raise dirt before performing a washing operation for washing dishes with washing water. About.

  In order to enhance the washing effect in the washing operation in which washing water is sprayed on the dishwasher, before the above washing operation is started, the inside of the washing tank is filled with water vapor, and the dirt stuck to the dish rises. There is a dishwasher designed to perform steam operation.

  As such a dishwasher, for example, in Patent Document 1, by locally heating water, water vapor is generated in a short time, and steam operation can be performed efficiently in a washing tank. There has been disclosed a dishwasher in which a partition plate is provided around a heater so as to divide the heater into an installation area and outside the area.

  Patent Document 2 discloses a dishwasher in which a steam generator for generating steam is incorporated in a water supply path for supplying water to a washing tank so that steam operation can be performed efficiently. Yes.

  However, in the case of the tableware washing machine of the above-mentioned patent document 1, a partition plate must be provided in the washing tank, and there is a problem that the structure becomes complicated and the tableware washing machine becomes large.

  Moreover, in the case of the tableware washing machine of the said patent document 2, since a steam generator is attached separately from a washing tank, there exists a problem that the water path becomes complicated and the reliability with respect to a water leak etc. falls.

JP 2009-165777 A JP 2009-106488 A

  The present invention solves the above-mentioned problems, can efficiently generate steam used for steam operation without requiring special parts and equipment, is highly reliable, and has excellent durability. The object is to provide a dishwasher.

In order to achieve the above object, the dishwasher of the present invention comprises:
A washing tub configured to store the tableware to be washed and store the washing water up to a reference water level;
A heater that is disposed in a position closer to the water surface side of the cleaning water at the reference water level than the bottom surface of the cleaning tank, and that heats the cleaning water stored in the cleaning tank;
A pump for sucking the washing water and ejecting it from the ejection nozzle into the washing tank;
Temperature detecting means for detecting the temperature of the bottom surface of the cleaning tank in the heater installation region in plan view;
A seasonal determination means for determining the season, and
By energizing the heater, the cleaning water stored in the cleaning tank is heated, and after performing steam operation to generate steam in the cleaning tank,
The cleaning water heated by the steam operation is sucked by the pump, and is configured to perform a cleaning operation for cleaning the dishes by ejecting the cleaning water from the ejection nozzle into the cleaning tank,
For the output of the temperature detection means, a threshold value is set for switching the energization state of the heater from on to off in the steam operation, and the threshold value for the output of the temperature detection means is used as the output of the season determination means. It is characterized in that it is configured to be set accordingly.

  Moreover, in the dishwasher of this invention, it is preferable to perform the season determination by the season determination means based on the output of the temperature detection means when a predetermined time or more has elapsed since the energization of the heater was stopped.

  Moreover, it is preferable that the threshold value for the output of the temperature detection means is set according to the output of the season determination means and the output of the temperature detection means at the start of the steam operation.

  Further, the output of the pump is variable, and when the cleaning operation is started after completion of the steam operation, the pump is first operated with an output smaller than the rated output for the cleaning operation. It is preferable to increase the pump output to the rated output for the washing operation.

  As described above, the dishwasher of the present invention is disposed in a position closer to the water surface side of the washing water at the reference water level than the bottom surface of the washing tank and the washing water stored in the washing tank. A heater for heating the water, a pump for sucking cleaning water and ejecting it from the ejection nozzle into the cleaning tank, a temperature detecting means for detecting the temperature of the bottom surface of the cleaning tank below the area where the heater is disposed, and a seasonal determination After the steam operation in which the cleaning water stored in the cleaning tank is heated by the heater and steam is generated in the cleaning tank, the cleaning water is sucked by the pump and ejected from the ejection nozzle into the cleaning tank A threshold for switching the energized state of the heater from on to off in the steam operation for the output of the temperature detection means, and the temperature detection means Output Since all threshold values are set according to the output of the seasonal determination means, steam can be generated efficiently without the need for special parts or equipment, and the reliability is high. It becomes possible to provide a dishwasher with excellent durability.

  That is, in the storage portion of the cleaning tank in which the cleaning water is stored, the cleaning water positioned below the heater installation position is unlikely to generate convection even when the heater is heated. Since the cleaning water below the heater is prevented from being heated unnecessarily, the cleaning water above the heater is mainly used. To generate steam efficiently.

  In addition, since the heater energization control is performed by the output of the temperature detection means according to the season by the output of the season determination means, the temperature of the cleaning water around the heater is difficult to be transmitted away from the heater. Although the temperature is detected by the temperature detecting means provided on the bottom surface, the energization control can be performed so that the temperature of the cleaning water around the heater is maintained at an appropriate temperature. Therefore, the washing water above the heater can be prevented from being excessively heated, and a dishwasher that is safe and excellent in durability can be provided.

  If the season determination means is provided and the heater energization control is not required according to the output, the temperature detection means is away from the heater and the temperature of the cleaning water around the heater is not easily transmitted. Since it is disposed, the temperature detecting means detects a temperature greatly deviating from the temperature of the cleaning water around the heater, and this causes a problem such as an excessive increase in the temperature around the heater.

In addition, when the seasonal determination by the seasonal detection means is performed by the output of the temperature detection means when a predetermined time or more has passed since the energization of the heater is stopped, the seasonal detection can be performed by the temperature detection means. Season determination can be performed without requiring a special sensor for the season determination means.
The dishwasher of the present invention can also be configured to determine the season based on the output of a temperature sensor that detects the water supply temperature to the device and the outside air temperature around the device, which is different from the temperature detection means. is there.

In addition, when the threshold for the output of the temperature detection means is set according to the output of the season determination means and the output of the temperature detection means at the start of steam operation, in addition to the season determination means, the latest device operation The heater on / off control can be performed in consideration of the influence on the temperature detection means by the heater, and the heater energization control can be performed with higher accuracy.
However, in the dishwasher of the present invention, heater energization control can be performed regardless of the output of the temperature detection means at the time of starting steam operation.

In addition, the pump output is variable, and when the cleaning operation is started after the steam operation is completed, the pump is first operated at an output smaller than the rated output for the cleaning operation, and the pump output is cleaned as time passes. When the rated output is increased (soft start operation is performed), the steam is filled and the space inside the cleaning tank is hot. Inflow sound (passing sound) caused by a sudden drop in the pressure in the washing tank due to the cooling of the washing tank space being rapidly cooled by jetting the relatively cold wash water from the jet nozzle into the washing tank And the deformation of the washing tank can be prevented.
In the dishwasher of the present invention, by providing a pressure relief valve, even when the pressure in the washing tank changes suddenly without performing a soft start operation, air passage noise is generated and the washing tank is deformed. It is also possible to configure so that this is prevented.

It is a perspective view which shows the structure of the principal part of the dishwasher concerning the Example of this invention. It is side surface sectional drawing of the dishwasher concerning the Example of this invention. It is a perspective view which shows schematic structure of the inner side area | region of the door body of the dishwasher concerning the Example of this invention. It is a disassembled perspective view which shows schematic structure of the inner side area | region of the door body of the dishwasher concerning the Example of this invention. It is a perspective view which shows the structure of the drying unit used in the dishwasher concerning the Example of this invention, Comprising: It is a figure which shows the state which removed the front side division | segmentation casing part. It is a front view which shows the structure of the drying unit used in the dishwasher concerning the Example of this invention. It is a figure for demonstrating operation | movement of the dishwasher concerning the Example of this invention. It is a figure explaining the aspect of the output of the season determination result of the season determination means which comprises the dishwasher concerning the Example of this invention.

Hereinafter, examples of the present invention will be shown and the features thereof will be described in more detail.
FIG. 1 is a perspective view showing a configuration of a main part of a dishwasher according to an embodiment of the present invention (a dishwasher / dryer in this embodiment), FIG. 2 is a side sectional view, and FIG. 3 is a diagram of the dishwasher according to the present invention. It is a perspective view which shows schematic structure of the inner side area | region of a door body. FIG. 7 is a diagram for explaining the operation of the dishwasher according to the embodiment of the present invention.

  The dishwasher of this embodiment is a drawer-type dishwasher. As shown in FIGS. 1, 2, and 3, a rectangular parallelepiped main body 1 having a front surface opened, and the main body 1 And a washing tank D having a substantially rectangular shape in plan view, which is arranged in such a manner that each operation of the drawer movement and the storage movement can be performed freely.

  The cleaning tank D includes a drawer 2, and the main body 1 includes a slide rail mechanism (not shown) that supports the drawer 2 so as to be movable with respect to the main body 1. And the drawer | drawing-out part 2 is comprised so that it can pull out so that most may be exposed outside the main-body part 1. As shown in FIG.

  Further, the main body portion 1 closes the upper surface portion of the cleaning tank D while the drawer portion 2 is housed in the main body portion 1, and the upper surface of the cleaning tank D when the drawer portion 2 is pulled out from the main body portion 1. An inner lid portion 3 for opening the portion is provided, and a cleaning space Q that can be opened and closed is secured in the internal space of the cleaning tank D (see FIG. 2).

The front part of the drawer part 2 is provided with a door body A that opens and closes the opening of the front part of the main body part 1. When the drawer part 2 is pulled out from the main body part 1 or stored, A gripping part B for gripping is provided. Although not described in detail, the gripping portion B is provided with an engaging means P that engages with the locking portion Pa of the main body 1 as the drawer 2 is housed in the main body 1. When the engaging means P is engaged with the locking portion Pa, the drawer portion 2 is configured to be held in the main body portion 1. And the engaging means P is comprised so that it can cancel | release engagement and can cancel | release an engagement state with the finger | toe which is holding the holding part B, when pulling out the drawer part 2 from the main-body part 1. Yes. Further, the door body A is provided with an operation unit SS for performing various operations for driving.
Moreover, in the dishwasher of this Example, as shown in FIG. 7, the water supply path 4 which supplies the water to the washing tank D, and the water supply valve 4a which opens and closes the water supply path 4 are provided.

  A pump (combined pump) 6 that functions as a cleaning pump in the forward direction and functions as a drainage pump in the reverse direction is provided below the bottom of the cleaning tank D in the drawer 2. In addition, a cleaning nozzle 8 and an electric heater 9 as a heating means are disposed inside the cleaning tank D, and a cleaning basket 10 for storing and placing a cleaning object such as tableware is provided in the cleaning tank D. It is detachably mounted inside.

The pump 6 is connected to the water storage recess S formed at the bottom of the cleaning tank D via the suction pipe 11. The pump 6 is connected to a drain pipe 12 for draining.
Further, a water level sensor J is connected to the water storage recess S via a guide tube 13.
As shown in FIG. 2, a drain pan 14 for receiving water leakage is provided at the bottom of the main body 1, and although not particularly shown, the drain pan 14 detects water leakage that detects the presence or absence of the received water. Equipped with a sensor.

  As shown in FIGS. 2, 3, 4 and 7, the front side wall Df corresponding to the front side of the machine body, that is, the front side of the drawer, out of the four side walls in the cleaning tank D is dried. Unit K is attached.

  That is, as shown in FIG. 4 and the like, the air supply port 21 that supplies the air from the drying unit K to the cleaning space Q and the drying unit K suck the air in the cleaning space Q into the front side wall portion Df. The air suction port 22 is formed at a position away from the left and right sides on the lower side. Specifically, the air supply port 21 and the air suction port 22 are formed so as to be positioned below the cleaning basket 10, and in this embodiment, the air supply port 21 is located on the right side and the air suction is performed. The mouth 22 is located on the left side.

  As shown in FIGS. 3 to 7 and the like, the drying unit K has a ventilation path F extending from the air suction port 22 to the air supply port 21 inside the casing 15 fixed to the front side wall portion Df of the cleaning tank D. A circulation fan (ventilating means) 23 that circulates the air in the cleaning space Q and a dehumidifying part G that dehumidifies the air circulated through the ventilation path F are provided. As the circulation fan (ventilating means) 23, a sirocco fan is used.

  As shown in FIG. 7, the ventilation path F includes an ascending path part f1 extending upward from the air suction port 22 and a descending path part f2 extending downward from the upper end of the ascending path part f1 toward the air supply port 21. The dehumidifying part G is disposed in the ascending path part f1, and the circulation fan (ventilating means) 23 is disposed in the descending path part f2.

  In the dishwasher of this embodiment, as shown in FIG. 7, the dehumidifying water supply passage 26 for supplying the dehumidifying cooling water to the distribution nozzle 51 and the dehumidifying cooling water interrupting valve 27 for opening and closing the dehumidifying water supply passage 26 are further provided. And a governor 28 for stabilizing the feed water pressure. The governor 28 stabilizes the water supply pressure so that the flow rate of water supplied to the distribution nozzle 51 of the dehumidifying cooling water supply means 25 can be maintained substantially constant (0.15 liter / min in the embodiment). It is configured.

  Next, the air flow in the ventilation path F of the dishwasher of this embodiment will be described. As shown in FIGS. 5 and 6, when the circulation fan (ventilating means) 23 is operated, air is sucked from the suction opening 23 </ b> A, and the air inside the cleaning space Q is separated from the side wall portion 15 a of the casing 15 and the partition wall 40. The fluid flows upward through the ascending path portion f1 partitioned by. The air discharged from the discharge portion 23B of the circulation fan 23 flows downward through the descending path portion f2 and is supplied from the air supply port 21 into the cleaning space Q.

  In the dishwasher of this embodiment, the rising path portion f1 is partitioned by a plurality of (in this embodiment, five) heat transfer bodies 24a to form a slit-shaped divided path, and the air passing through the rising path portion f1 is It passes through each slit-like divided path.

  The air containing a large amount of water passing through each slit-shaped divided path passes through each heat transfer body 24a and its surface efficiently cooled by the dehumidifying cooling water flowing almost uniformly from the respective flow outlets 53 of the distribution nozzle 51. It cools in contact with the flowing down dehumidifying cooling water, and moisture in the air is condensed and separated.

  The dehumidifying cooling water that has flowed down from each flow-down port 53 returns to the cleaning tank D through the air suction port 22 together with the condensed water, and is stored in the water storage recess S.

  Then, in a state where the heater 9 is operated, the circulation fan (ventilating means) 23 is operated to suck air from the cleaning space Q, and the air is passed through the ventilation path F and dehumidified from the flow-down port 53 of the distribution nozzle 51. The cooling water is allowed to flow down to dehumidify the air sucked from the cleaning space Q in the dehumidifying part G, and the dehumidified air is circulated and supplied to the cleaning space Q as drying air, and the supplied air is used as a heater. By performing heating at 9, a drying operation for drying the object to be cleaned in the cleaning space Q is performed.

  Further, with the heater 9 stopped, the air in the cleaning space Q is ventilated through the ventilation path F, and the dehumidifying section G is brought into contact with the dehumidifying cooling water flowing down from the flow-down port 53 of the distribution nozzle 51 to enter the air. By deodorizing the circulating air by absorbing and removing odorous components such as ammonia and trimethylamine contained in the cooling water for dehumidification.

  In addition, after the odor component in the air sucked from the cleaning space Q is absorbed by the dehumidifying cooling water in the dehumidifying part G and separated, and then supplied to the cleaning space Q, the cleaning space Q is also deodorized. become.

  In the case of this dishwasher, as shown in FIG. 7, the drawer unit 2 is equipped with a control unit H as a control means for controlling operation, and this control unit H is input at the operation unit SS. The operation of the water supply valve 4 a, the pump 6, the heater 9, the circulation fan (ventilating means) 23, and the dehumidifying cooling water interrupting valve 27 is controlled based on the command to be performed, and the cleaning space Q inside the cleaning tank D is controlled. Operation for performing a cleaning process with a cleaning liquid (hot water), and a rinsing operation for rinsing the cleaning object with rinsing water stored in the water storage recess S of the cleaning tank D and heated by the heater 9 , A drain operation for draining the rinse water stored in the water storage concave portion S of the washing tank D, and a ventilation nozzle by the circulation fan 23 and a distribution nozzle 51 of the dehumidifying cooling water supply means 25 with the heater 9 heated. Cold for dehumidification Cooling for dehumidification from the distribution nozzle 51 in the cooling water supply means 25 for ventilation and dehumidification cooling water supply means 25 with the circulation fan 23 in a state where the heater 9 is stopped while supplying water (flowing down) and drying the air. Operation such as deodorization operation is performed to deodorize air by supplying water (flowing down). That is, the control unit H is configured to control the operation of the circulation fan 23 and the dehumidifying unit G so that the air in the cleaning space Q is circulated while dehumidifying in the drying process.

  In addition, the dishwasher of this embodiment is a continuous operation course that allows the user to operate in the order of washing operation, rinsing operation, drainage operation, drying operation, and deodorizing operation by the operation unit SS, or drying that allows only the drying operation to be operated. Various driving courses such as an only course can be selected, and a standard driving course, a careful driving course, a speedy driving course, and a fast driving course are provided as continuous driving courses.

Hereinafter, the control operation of the control unit H will be described.
First, it is detected by a storage switch (not shown) that the drawer unit 2 is stored in the storage position of the main body unit 1, and when the power switch of the operation unit SS is turned on, a driving course is selected.

  When the start switch of the operation unit SS is turned on, the standard operation course starts, and the cleaning operation, the rinsing operation, the draining operation, the drying operation, the deodorizing operation, and the draining operation are sequentially executed.

  In the cleaning operation, when the water supply valve 4a is opened and cleaning water is supplied into the cleaning tank D through the water supply passage 4, and the water level sensor J detects that the water level has reached the set water level, the water supply valve 4a The cleaning operation for performing the water supply operation for closing the water, and then rotating the pump 6 forward and the heater 9 to eject the cleaning water from the cleaning nozzle 8 toward the object to be cleaned is performed for the set time for the cleaning operation. Then, the pump 6 is reversely operated, and the draining operation for draining the cleaning water in the cleaning tank D is performed.

  Further, in the rinsing operation, a water supply operation similar to the water supply operation in the above-described cleaning operation is performed, the rinsing water is stored at the set water level at the bottom of the cleaning tank D, and then the pump 6 is rotated forward so that the object is cleaned. The rinsing water jetting operation for jetting rinsing water from the washing nozzle 8 until the set time elapses, and the draining operation for draining the rinsing water stored in the bottom of the washing tank D by rotating the pump 6 in reverse. The rinsing operation is performed twice, and finally the heating rinsing operation is performed.

  In the heating rinsing operation, the rinsing water is stored at the bottom of the cleaning tank D by the above-described water supply operation, and then the pump 6 and the heater 9 are operated, and the rinsing water heated by the heater 9 is used to rinse the object to be cleaned. I do. When the temperature of the rinsing water reaches the finishing set temperature (for example, 67 ° C.) by the thermistor TH (see FIG. 2), the heating rinsing operation is terminated.

  In the drainage operation, the pump 6 is operated in reverse to drain the rinse water stored in the bottom of the cleaning tank D, and the rinse water stored in the bottom of the cleaning tank D is discharged by the water level sensor J. Do this until it is detected.

  In the drying operation, with the heater 9 being heated, the ventilation operation by the circulation fan 23 and the supply operation of the dehumidifying cooling water from the distribution nozzle 51 of the dehumidifying cooling water supply means 25 are performed, and this state is used for drying. Continue until a set time (for example, 25 minutes) elapses.

  The dehumidifying cooling water is supplied from the distribution nozzle 51 of the dehumidifying cooling water supply means 25 by opening the dehumidifying cooling water intermittent valve 27 and supplying water to the distribution nozzle 51 via the dehumidifying water supply channel 26. The cooling water for dehumidification is made to flow down from the flow down port 53 of the distribution nozzle 51. At this time, the flow rate of the dehumidifying cooling water is maintained substantially constant (0.15 liter / min in the embodiment) by the governor 28 for stabilizing the feed water pressure.

  The dehumidifying cooling water supplied (flowed down) from the flow down port 53 of the distribution nozzle 51 flows down through the rising path portion f1 in the ventilation path F, is guided by the inner surface of the casing 15, and is stored in the water storage recess S. The

  And every time set time passes so that the heater 9 may not be immersed by the dehumidification cooling water stored, or the water level of the recessed part S for water storage is the set water level for drainage in the water level sensor J. When this is detected, the pump 6 is reversely operated to perform drainage processing for discharging the dehumidifying cooling water to the outside.

  When the drying operation is started and the set time for drying elapses, heating of the heater 9 and ventilation by the circulation fan 23 are stopped, the dehumidifying cooling water intermittent valve 27 is closed, and the supply of water to the distribution nozzle 51 is stopped. Then, the flow of the dehumidifying cooling water from the distribution nozzle 51 is stopped.

  In the deodorizing operation, with the heater 9 stopped, the ventilation operation by the circulation fan 23 and the dehumidifying cooling water supply operation from the distribution nozzle 51 of the dehumidifying cooling water supply means 25 are performed, and the state is deodorized. Maintain until set time has passed. In this deodorizing operation, as in the case of the drying operation described above, every time the set time elapses or the water level sensor J detects that the water level of the water storage recess S is the set water level for drainage. Sometimes, the pump 6 is operated in reverse to perform a drainage process for discharging the dehumidifying cooling water ejected from the distribution nozzle 51 and stored in the water storage recess S to the outside.

  When the set time for deodorization elapses after the start of the deodorizing operation, the ventilation operation by the circulation fan 23 and the supply operation of the dehumidifying cooling water from the distribution nozzle 51 of the dehumidifying cooling water supply means 25 are stopped to eliminate the deodorization. End driving.

  Then, after the deodorizing operation is completed, the drainage operation is performed. In this drainage operation, the water level sensor J drains the dehumidifying cooling water stored in the drainage operation of discharging the dehumidifying cooling water stored in the water storage recess S by operating the pump 6 in the reverse direction. Continue until it is detected.

  When the water supply operation is performed in the cleaning operation and the rinsing operation, a process of opening the dehumidifying cooling water interrupting valve 27 and supplying water to the distribution nozzle 51 through the dehumidifying water supply passage 26 is also performed. I also try to do it together. In this way, water is supplied from the dehumidifying water supply channel 26 to the dehumidifying part G without wasting water, so that the dehumidifying part G is kept as clean as possible.

In the dishwasher of this embodiment, as shown in FIG. 2, the thermistor TH is disposed as a temperature detecting means so as to be in close contact with the bottom surface of the washing tank D. The thermistor TH is directly behind the bottom surface of the cleaning tank D corresponding to the region where the heater 9 is disposed in plan view (that is, directly below the position where the heater 9 is disposed on the back side of the bottom surface of the cleaning tank D). Position).
When the user turns on the power switch of the operation unit SS, the thermistor is operated when a predetermined time (for example, 5 hours) has elapsed since the energization of the heater 9 was stopped in the control unit H (FIG. 7). From the output of the detected temperature of TH, the season determination means determines the season. In addition, in the dishwasher of this Example, the control part H is comprised so that the function as a season determination means may be fulfill | performed together.

In the dishwasher of this embodiment, for example, the result of the season determination as shown in Table 1 and FIG. 8 based on the detected temperature of the thermistor TH when 5 hours or more have passed since the energization of the heater 9 was stopped. Is output.
The initial setting is “Spring / Autumn”.
Further, when 5 hours or more have not passed since the energization of the heater 9 is stopped, the previous determination result is used.

  The output of the season determination will be described with reference to Table 1 and FIG. 8. If the detected temperature of the thermistor TH when 5 hours or more have elapsed is, for example, 25 ° C. or more, the determination result that the season is summer is output. Thereafter, when the detected temperature decreases to 23 ° C., it is determined that the season has changed from summer to spring / autumn. Thereafter, when the detected temperature falls below 12 ° C., it is determined that the season has changed from spring / autumn to winter. Thereafter, when the detected temperature reaches 14 ° C., it is determined that the season has changed from winter to spring / autumn.

  The season determined by the season determination means is used for setting temperature selection (threshold value selection) in steam operation, which will be described later.

Next, the operation when washing dishes using this dishwasher will be described.
For example, when the user selects a careful operation course from the operation unit SS, the steam operation is performed before the cleaning operation.

In the steam operation, as shown in FIG. 7, when the water supply valve 4 a is opened and the cleaning water is supplied into the cleaning tank D through the water supply passage 4 and the water level sensor J detects that the reference water level has been reached. Then, a water supply operation for closing the water supply valve 4a is performed. The reference water level at this time is the same as the cleaning water level during the cleaning operation.
In this embodiment, the water level sensor J is shared for steam operation and cleaning operation. However, it is also possible to provide a water level sensor separately, separately from the reference water level for steam operation and the cleaning water level for cleaning operation.

  The position of the heater 9 in the vertical direction when the water is supplied to the reference water level is biased toward the water surface side of the cleaning water at the reference water level from the bottom surface of the cleaning tank D. However, the arrangement position (height) of the heater 9 is set so as to be surely submerged in the cleaning water at the reference water level even if it is biased toward the water surface (see the liquid level L in FIG. 2).

  Then, when energization of the heater 9 is started with the pump 6 stopped, the water around the heater 9 is heated, and the cleaning water located above the heater 9 is mainly heated (below the heater 9). The side wash water is less likely to be heated because convection due to the heating of the heater 9 is difficult to occur, but the wash water located above the heater 9 is efficiently heated due to the occurrence of convection due to the heating of the heater 9. )

As time elapses after the heater 9 is energized and the temperature of the cleaning water on the upper side of the heater 9 increases, steam (steam) is generated, and the temperature in the cleaning tank D rises. Water exceeding the saturated water vapor amount floats in the gas phase in the cleaning tank D as steam.
When steam containing steam fills the washing tank, fine water molecules drift into the washing tank and enter between the dishes and the dirt, and the dirt on the dishes rises.
As shown in Table 2, heater energization control for controlling energization of the heater 9 is performed by a set temperature (threshold value) set (selected) in consideration of the output of the season determination means and the output of the temperature detection means. It is configured to be

Furthermore, in this embodiment, a threshold value for heater energization control is determined according to the temperature detected by the temperature detection means at the start of operation (temperature at the start of operation).
The temperature at the start of the operation is determined by the thermistor TH at the control unit H at a time point after the user selects a careful operation course by the operation unit SS and the water supply operation is finished and before the heater 9 is energized. The output of the detected temperature is stored and used for heater energization control as follows.
That is, as shown in Table 2,
(a) When the detected temperature at the start of operation is less than 35 ° C., the heater 9 is turned off from 46 ° C. in summer, 45 ° C. in spring / autumn, 45 ° C. in winter. ,
(b) When the detected temperature at the start of operation is 35 to 50 ° C., the heater 9 is turned off from 47 ° C. in summer, 46 ° C. in spring / autumn, 46 ° C. in winter West,
(c) When the detected temperature at the start of operation is 50 ° C. or higher, the heater 9 is turned off from 49 ° C. in summer, 48 ° C. in spring / autumn, and 48 ° C. in winter. Like to do.

  Note that the temperature when turning on the heater 9 from OFF to ON is 2 ° C. lower than the temperature shown in Table 2.

  When the dishes are washed by the dishwasher of this embodiment, specifically, the heater 9 is forcibly energized for the first three minutes from the start of the steam operation regardless of the output of the detected temperature of the thermistor TH.

Then, after 3 minutes from the start of the steam operation, when the output of the detected temperature of the thermistor TH reaches the set temperature shown in Table 2, the energization to the heater 9 is turned off. The operation of turning on the power to 9 is repeated, and steam is reliably generated while maintaining the temperature in the cleaning tank D at the target temperature (55 ° C. in this embodiment).
When a predetermined time (for example, 10 minutes) elapses from the start of the steam operation, energization of the heater 9 is stopped and the steam operation is ended.

  When shifting to the cleaning operation after finishing the steam operation, the soft start operation is performed for a predetermined time (for example, 15 seconds) before the start of the cleaning operation. The soft start operation is performed by gradually increasing the rotational speed of the pump 6 with time so that the rotational speed of the pump 6 becomes a target rotational speed as shown in Table 3.

  Specifically, the rotational speed (target rotational speed) of the pump 6 is 1700 rpm for 5 seconds after the start of the soft-start operation, and the rotational speed (target rotational speed) for 10 seconds after 5 seconds. ) At 1900 rpm for 10 seconds and until 15 seconds have elapsed, the operation is performed at a rotation speed (target rotation speed) of 2100 rpm, and thereafter the operation is performed at a rotation speed (target rotation speed) of 4100 rpm of the rated rotation speed. become.

  In this way, by performing the soft start operation for a predetermined time, it is possible to suppress and prevent the temperature in the cleaning tank D from dropping rapidly, and to generate air passing sound (noise) due to a rapid decrease in the pressure in the cleaning tank D. And the deformation of the washing tank can be prevented. That is, when the pump 6 is immediately operated at the rated rotational speed after the steam operation is finished and the operation is shifted to the cleaning operation, the temperature in the cleaning tank D rises but is close to the bottom surface on the lower side of the heater 9. Since the temperature of the washing water is low at the position, the temperature in the washing tank D is drastically lowered by the washing water sucked by the pump 6 and ejected from the washing nozzle 8, and the pressure in the washing tank D is drastically lowered. Although the air passing sound is generated and the cleaning tank is deformed, a rapid drop in temperature in the cleaning tank D can be prevented by performing the soft start operation for a predetermined time (for example, 15 seconds).

  After the above-mentioned soft start operation is completed, as described above, the cleaning is performed by cleaning the dishes by setting the rotational speed of the pump 6 to the rated rotational speed (4100 rpm) and ejecting cleaning water from the cleaning nozzle 8. Do the driving.

  As described above, the tableware can be efficiently cleaned by combining the steam operation and the cleaning operation. Moreover, by performing the soft start operation, it is possible to efficiently and comfortably wash dishes while preventing a sudden drop in the temperature in the washing tank D and comfortably preventing deformation of the washing tank. .

  In the above embodiment, the threshold value of the heater energization control is determined according to the temperature at the start of operation. However, in some cases, the temperature is detected by the output of the season determination means without considering the temperature at the start of operation. It is also possible to configure so as to define a threshold value for the output of the means, and in this case, the basic effect of the present invention can be obtained.

  The present invention is not limited to the above embodiment in other points, and various modifications can be made within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Main-body part 2 Drawer part 3 Inner cover part 4 Water supply path 4a Water supply valve 6 Pump (combined pump)
8 Washing nozzle 9 Heater 10 Washing basket 11 Suction tube 12 Drainage tube 13 Guide tube 14 Drain pan for receiving water leakage 15 Casing 15a Side wall portion 15A Front side divided casing portion 15B Rear side divided casing portion 21 Air supply port 22 Air suction口 23 Circulation fan (ventilation means)
23A Circulation fan suction opening 23B Circulation fan discharge part 24 Condensation part 24a Heat transfer body 25 Dehumidification cooling water supply means 26 Dehumidification water supply path 27 Dehumidification cooling water interrupting valve 28 Governor for stabilizing feed water 30 Holding member 40 Partition wall 51 Distributing nozzle 53 Downflow port A Door body B Gripping part D Cleaning tank Df Front side wall part F Ventilation path part f1 Ascending path part f2 Decreasing path part G Dehumidifying part H Control part J Water level sensor L Liquid level K Drying unit P Engagement Means Pa Locking part Q Cleaning space S Water storage recess SS Operation part TH Thermistor (temperature detection means)

Claims (4)

A washing tub configured to store the tableware to be washed and store the washing water up to a reference water level;
A heater that is disposed in a position closer to the water surface side of the cleaning water at the reference water level than the bottom surface of the cleaning tank, and that heats the cleaning water stored in the cleaning tank;
A pump for sucking the washing water and ejecting it from the ejection nozzle into the washing tank;
Temperature detecting means for detecting the temperature of the bottom surface of the cleaning tank in the heater installation region in plan view;
A seasonal determination means for determining the season, and
By energizing the heater, the cleaning water stored in the cleaning tank is heated, and after performing steam operation to generate steam in the cleaning tank,
The cleaning water heated by the steam operation is sucked by the pump, and is configured to perform a cleaning operation for cleaning the dishes by ejecting the cleaning water from the ejection nozzle into the cleaning tank,
For the output of the temperature detection means, a threshold value is set for switching the energization state of the heater from on to off in the steam operation, and the threshold value for the output of the temperature detection means is set as the output of the season determination means. A dishwasher characterized in that it is configured to be set according to the conditions.   2. The dishwasher according to claim 1, wherein the season determination by the season determination unit is performed based on an output of the temperature detection unit when a predetermined time or more has elapsed after the energization of the heater is stopped.   The threshold value for the output of the temperature detection means is configured to be set according to the output of the season determination means and the output of the temperature detection means at the start of the steam operation. The dishwasher according to 1 or 2.   The pump output is variable, and when the cleaning operation is started after completion of the steam operation, the pump is first operated with an output smaller than the rated output for the cleaning operation. The dish washer according to any one of claims 1 to 3, wherein the output is increased to the rated output for the washing operation.

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