JP2008012041A - Dishwasher - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dishwasher mounted with a reliable steam generator. <P>SOLUTION: In the case of carrying out "a steam process" for humidifying an object to be washed before "a washing process", "water supply operation" of supplying water to a steam generation unit 28 intermittently by a water supply valve 26b is carried out for five minutes while a heater 34 is energized, and energizing to the heater 34 is carried out for one minute to carry out "drying operation" of drying a steam generation part 29a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dishwasher including a washing pump that supplies washing water to a washing nozzle.

A household dishwasher pumps washing water stored in a washing tank to a washing nozzle as a washing means by a washing pump, and jets washing water from the injection nozzle to the dishes by the water pressure for washing. A cleaning process is being performed. And before this washing process, the steam process is performed in order to swell dirt stuck to the surface of the tableware and improve the washing efficiency in the washing process (for example, refer to patent documents 1).
JP 2003-265394 A (FIG. 12)

  Conventionally, in the tank of the steam generating means after the completion of the steam stroke, residual water sometimes occurs without being partitioned by evaporation due to residual heat of the tank. In this case, the remaining water stays in the tank for a long time. In this situation, the inner surface of the tank is likely to deteriorate. In particular, when the tank is made of a metal material, the corrosion of the metal material is promoted and the corrosion proceeds. Then, there was a possibility that the steam could not be supplied to the cleaning tank.

  This invention is made | formed in view of the above-mentioned situation, Therefore The objective is to provide the dishwasher which can remove the residual water which remained in the steam production | generation part.

  In order to achieve the above object, a dishwasher according to the present invention comprises an outer box, a cleaning tank provided in the outer box for containing an object to be cleaned, and a first water supply means for cleaning water to the cleaning tank. Draining means for discharging cleaning water in the cleaning tank, cleaning means for cleaning the object to be cleaned in the cleaning tank, steam generating means for generating steam to be supplied into the cleaning tank, and steam generation A second water supply means for supplying water to the means, and a control means for executing a cleaning course including a steam stroke performed by controlling the steam generation means, the steam generation means being connected to the second water supply means A water supply port, a steam discharge port communicating with a spout provided in the cleaning tank, a metal steam generation unit, and a steam generation heat source arranged to heat the evaporation generation unit The last of the second water supply means in the steam stroke of the control means After water operation execution, to perform the drying operation is intended to mainly characterized.

  In the present invention, it is possible to reduce the time during which the steam generating unit of the steam generating means is immersed in water by removing the residual water. For this reason, corrosion of a metal steam generation part can be controlled.

(First embodiment)
Hereinafter, a first embodiment in which the present invention is applied to a household dishwasher will be described with reference to the drawings.

  FIG. 1 shows a longitudinal sectional view of the dishwasher 1. In FIG. 1, a dishwasher 1 includes an outer box 3 in which a cleaning tank 2 is installed, and a lower door 4 provided to open and close a front opening of the cleaning tank 2 on the front surface of the outer box 3. And the operation panel 6 provided under the upper door 5 and the lower door 4 is provided. The operation panel 6 is provided with various switches and a display unit.

  The lower door 4 is pivotally supported by the outer box 3 at the lower end portion thereof, and the upper door 5 is pivotally supported by the outer case 3 at the upper end portion thereof. It is configured to rotate. The lower door 4 and the upper door 5 are configured so that the closed state is held by a lock mechanism (not shown), and the lower door 4 and the upper door 5 are opened by releasing the lock mechanism. An exhaust port 7 is provided above the upper door 5 so as to communicate with the inside of the cleaning tank 2 and serve to exhaust the air in the cleaning tank 2.

  Inside the washing tank 2, two upper and lower tableware baskets 8a and 8b are accommodated in a removable manner.

In addition, at least the bottom wall part of the cleaning tank 2 is formed of a synthetic resin.

  An injection nozzle 9 (corresponding to a cleaning means) for injecting cleaning water toward the tableware stored in the tableware baskets 8a and 8b is fixed to the back wall in the cleaning tank 2. The spray nozzle 9 has a configuration in which a plurality of spray holes 9b (only one is shown) are formed on the front surface of a band-shaped hollow member 9a extending left and right along the back wall of the cleaning tank 2. A cylindrical portion 10 extending to the lower portion of the cleaning tank 2 is integrally communicated with the middle portion of the hollow member 9a. Further, two rotary spray nozzles 11 (corresponding to the cleaning means, one on the left side) for spraying the cleaning water toward the tableware stored in the tableware baskets 8a and 8b are provided at the bottom of the cleaning tank 2. Only shown) side by side.

These injection nozzles 11 have a structure that self-rotates in response to the washing water injection, and has a structure in which a plurality of injection holes 11b are formed on the upper surface of the hollow arm portion 11a, and the base end of the arm portion 11a. The part is rotatably connected to the arm support 12.

  A water storage portion 13 is formed in a recessed manner at the front portion (front side) of the bottom portion of the cleaning tank 2. A right side portion of the water storage unit 13 is formed in a shallow bottom, and a heater 14 serving as a heat source for generating hot water is disposed in the shallow bottom portion. The water storage section 13 is provided with a detachable residual filter (not shown) at the bottom on the left side thereof, and a protective cover 15 made of a metal porous plate is placed over the heater 14. .

  In the space between the bottom of the cleaning tank 2 and the bottom of the outer box 3, a pump 16 that also serves as a cleaning pump and a drain pump and a blower 17 (see FIG. 3) are disposed. Although not described in detail, the pump 16 includes a casing 18 that houses a cleaning impeller and a drain impeller (both not shown), and a pump motor 47 that rotationally drives the cleaning impeller and the drain impeller. Yes. When the pump motor 47 rotates in the forward direction, for example, the pump 16 functions as a cleaning impeller and does not function as a drain impeller. On the other hand, when the pump motor 47 rotates in the reverse direction, the drain impeller functions and the cleaning impeller does not function. That is, the pump 16 is configured to be switchable between a state that functions as a cleaning pump and a state that functions as a drainage pump by switching the rotation direction of the pump motor 47.

  A cleaning discharge port (not shown) is provided in the upper portion of the casing 18, and the discharge port is connected to the lower portions of the arm support 12 and the tubular portion 10 through water distribution pipes 19 a and 19 b, respectively. Yes. A drain outlet (not shown) is provided on the side of the casing 18, and a drain hose 20 is connected to the outlet. The drainage hose 20 is drawn out from the lower part of the rear side portion of the outer box 3 through a position higher than the highest water level in the cleaning tank 2.

  A cylindrical portion 21 is integrally communicated with the bottom portion of the casing 18, and this cylindrical portion 21 is connected to a lower end portion of a water storage portion 13 (a depth at which a residual filter is disposed) via a connecting pipe 22 extending in a lateral direction. (Bottom). Although not shown, a cleaning suction port and a discharge suction port are formed at a position corresponding to the inside of the cylindrical portion 21 in the lower portion of the casing 18. On the other hand, the inside of the connecting pipe 22 is divided into a cleaning water channel and a drainage channel, and the end of the cleaning water channel communicates with the cleaning suction port, and the end of the drainage channel communicates with the drainage suction port. Yes.

  In this case, when the pump 16 functions as a drainage pump, the wash water in the water storage section 13 passes through the drainage passage in the connection pipe 22 and is sucked into the casing 18 from the drainage suction port, and then the casing 18. Is discharged to the outside through a drainage hose 20 from a discharge outlet for drainage provided on the side of the drainage. On the other hand, when the pump 16 functions as a cleaning pump, the cleaning water in the water reservoir 13 passes through the cleaning water channel in the connection pipe 22 and is sucked into the casing 18 from the cleaning suction port. The cleaning water sucked in this way is discharged to the water distribution pipes 19 a and 19 b from the cleaning discharge port provided in the upper part of the casing 18, and is injected into the cleaning tank 2 from the injection nozzles 9 and 11.

  The blower 17 is disposed in the vicinity of the heater 14 in the space between the bottom of the cleaning tank 2 and the bottom of the outer box 3. The blower 17 includes a fan and a fan motor (both not shown) housed in a casing, and the casing 23 is communicated with the vicinity of the heater 14 in the cleaning tank 2 via a blower pipe 24. ing.

  A water supply port 25 is provided at the center of the rear part of the bottom of the cleaning tank 2. The water supply port body 25 has a cylindrical portion 25a integrally formed in a form penetrating the bottom of the cleaning tank 2 in the vertical direction, and an upper portion of the cylindrical portion 25a with a predetermined gap therebetween. It is comprised from the cover 25b to cover. Further, a water supply pipe 27 is connected to the lower part of the cylindrical part 25a through an electromagnetic valve 26. This electromagnetic valve 26 is composed of a three-way valve that can control the opening and closing of the two valves independently, and controls the supply of water to the cleaning tank 2 by the water supply valve 26a on the cleaning tank 2 side as the first water supply means. The water supply valve 26b, which is the other second water supply means, controls the supply of water to the steam generation means described later. The water supply pipe 27 penetrates the lower part of the rear portion of the outer box 3 and is drawn to the outside of the outer box 3, and the drawer end is a water supply source such as a water supply via a water supply hose (not shown). To be connected to.

  Now, in the space between the bottom of the cleaning tank 2 and the bottom of the outer box 3, a steam generation unit 28 is disposed as a steam generation means related to the gist of the present invention. 28 and the configuration of related parts will be described. The steam generation unit 28 is attached and fixed to the bottom of the cleaning tank 2.

  FIG. 2 shows a longitudinal sectional view of the steam generation unit 28.

  In this figure, a steam generating unit 28 fixes a rectangular lid portion 30 for closing the upper surface opening to a main body portion 29 formed in a flat rectangular (rectangular) container shape by screwing. It has a structure. In this case, in the steam generation unit 28, the width dimension and the heat resistance packing 31 having a rectangular frame shape are interposed on the entire circumference of the contact portion between the main body portion 29 and the lid portion 30. It is formed in an airtight container shape with a relatively low height dimension compared to the depth dimension. The main body 29 and the lid 30 are formed by die-casting, for example, aluminum which is a metal having good thermal conductivity. Of course, the metal material is not limited to aluminum, and may be zinc, stainless steel, or the like having good heat conduction efficiency.

  The concave portion in the main body 29 functions as the steam generation unit 29 a, and the water supply port 32 and the steam discharge port 33 of the lid 30 have a water supply port 32 and a steam discharge port 33 at a position facing the steam generation unit 29 a from above. They are formed in a state of being separated from each other in the longitudinal direction. The water supply port 32 and the steam discharge port 33 have a structure including cylindrical bodies 32a and 33a that are integrally formed so as to protrude upward from the upper surface of the lid portion 30, and in this case, the cylindrical body 32a. The inner diameter (the diameter of the water supply port 32) is relatively small, whereas the cylindrical body 33a has a relatively large inner diameter (the diameter of the steam discharge port 33).

  In addition, at a position corresponding to the water supply port 32 on the lower surface of the lid portion 30, a partition wall portion 32 b having a semicircular cross section that is configured to surround the water supply port 32 from the direction of the steam generation unit 29 a protrudes downward. It is integrally formed.

  In the main body 29, the bottom of the steam generation unit 29 a (corresponding to the inner bottom of the steam generation unit 28) is formed in a shape that is inclined downward from the water supply port 32 side toward the steam discharge port 33 side. Further, at the bottom of the steam generation part 29a, a step part 29b is formed at a part facing the water supply port 32 from below from the other part, and the upper surface of this step part 29b is the top of the steam generation part 29a. The structure is inclined downward toward the center.

  A U-shaped heater 34 (corresponding to a heat source for generating steam) is attached to and integrated with a bottom wall portion of the main body 29. The heater 34 is arranged along the periphery of the main body 29, and the power terminals 34a (only one is shown) at both ends are connected to the side of the main body 29 (the surface on the stepped portion 29b side). It protrudes to the outside. The steam discharge port 33 is provided at a position substantially corresponding to the center of the arc-shaped bent portion of the heater 34, that is, a position corresponding to a portion where the heating energy by the heater 34 is most concentrated in the steam generation unit 28. Become.

  A heat radiating fin 35 extending in the longitudinal direction is integrally provided at the center of the bottom of the steam generator 29a in the main body 29. In addition, a hole (not shown) reaching the inside of the heat radiating fin 35 is formed in the center of the outer bottom surface of the main body 29, and in one hole, the bottom temperature of the steam generating unit 28, that is, A thermistor 36 (corresponding to a temperature sensor) for detecting the temperature of the steam generation unit 29a is accommodated. Further, a tapping screw 38 for fixing a press plate 37 for preventing the thermistor 36 from falling off is screwed into the other hole. Note that a plurality of heat radiation fins 39 arranged in a direction orthogonal to the heat radiation fins 35 are integrally formed on both side portions of the steam generation portion 29 a in the main body portion 29.

  In the steam generation unit 28 configured as described above, when water is supplied from the water supply port 32 while the heater 34 is energized, the water flows into the steam generation unit 29a and is heated. Steam is generated, and the heated steam is discharged from the steam outlet 33.

  As shown in FIG. 1, the steam generation unit 28 is in a horizontal state in the space between the bottom of the cleaning tank 2 and the bottom of the outer box 3 (the bottom of the steam generation unit 29 a is from the water supply port 32 side to the steam discharge port 33. And a control circuit unit 40 in which the power supply terminal (only one of them is shown) of the heater 34 is arranged at a position closer to the front side (the back side of the operation panel 6) in the space portion. (Corresponding to the control means).

  In this case, the water supply port 32 (particularly the cylindrical body 32a) of the steam generating unit 28 is provided with a water supply valve 26b (not shown) (corresponding to water supply means) via a tube 41 having flexibility and heat resistance of about 200 ° C. It is connected to. Moreover, as shown in FIG. 1, the cylindrical member formed in the form which penetrated the bottom part of the said cleaning tank 2 up and down is attached to the cleaning tank 2, and the cleaning tank side opening of this cylindrical member is the top. It is a spout 42. Further, the steam discharge port 33 (particularly, the cylindrical body) of the steam generation unit 28 is flexible and has a temperature of about 200 ° C. with respect to the cylindrical member (portion protruding downward from the bottom of the cleaning tank 2). It is connected via a tube 43 having heat resistance.

  In this case, the protruding portion into the cleaning tank 2 covers the upper end opening (that is, the spout 42) of the cylindrical member from above, and becomes a water vapor passage at a position below the upper end opening. A cover member 44 having an opening 44a is provided. As a result, there is no possibility that the cleaning water or bubbles in the cleaning tank 2 will flow into the steam generation unit 28 through the ejection port 42, and a situation in which the inside of the steam generation unit 28 is contaminated can be prevented.

  FIG. 3 shows an electrical block diagram. The control circuit unit 40, which is the aforementioned control means, includes an operation panel 6, a heater 14 for warm and dry water, a thermistor 45 for detecting the temperature of washing water and detecting the temperature during drying, a pump motor 47, a water level detection switch 46, and a blower 17. The heater 34, the thermistor 36, and the electromagnetic valve 26 are electrically connected.

  FIG. 4 is a timing chart of each operation such as cleaning and drainage in the entire standard cleaning course. The standard cleaning course includes “steam process”, “cleaning process”, “rinsing process”, and “drying process”. It is configured.

  First, when a tableware to be cleaned is set in the tableware baskets 8a and 8b and the operation panel 6 is operated to execute a standard cleaning course, the water supply valve 26a is opened and water supply to the cleaning tank 2 is started. Thereafter, when the water level detection switch 46 detects that 1.7 L of water has been supplied, the water supply valve 26a is closed and the supply of water ends. At this time, the thermistor 45 detects the temperature of the cleaning water in the cleaning tank 2, calculates the time required from the start of the cleaning course to the end based on the detected temperature, and a display unit provided near the operation panel 6 (Not shown).

  Next, the “steam stroke” is executed. The purpose of this “steaming process” is to make dirt adhered to the surface of the tableware float with water vapor and to be easily removed by a cleaning process performed thereafter. Basically, the heater 34 is energized, water is injected into the steam generation part 29a of the main body part 29 via the water supply valve 26b, the temperature of the steam generation part 29a is detected by the thermistor 36, and the detected temperature reaches the predetermined temperature again. The control for supplying water every time it is exceeded is executed for 5 minutes. This “steam stroke” will be described in detail with reference to the flowchart of FIG.

  When the “steam stroke” is completed, the water supply valve 26a is opened, and further, the cleaning tank 2 is supplied with water until the water level detection switch 46 detects 1.7 L of water to perform the “cleaning stroke”. Thereafter, the pump motor 47 is driven to rotate in the forward direction, and the water stored in the water storage unit 13 is supplied to the injection nozzles 9 and 11 to execute the cleaning operation of spraying the cleaning water toward the tableware. After a predetermined time elapses, the cleaning operation is terminated, and this time, the pump motor 47 is driven to rotate backward to drain the cleaning water in the cleaning tank 2 through the drain hose 20. In this “cleaning process”, the heater 14 is energized from the start of the process to the end of the process, and the temperature of the cleaning water is raised to nearly 60 ° C.

  The subsequent “rinsing process” includes two “shot rinsing processes” and “final rinsing processes”. The “shot rinsing process” is an operation in which the pump motor 47 is intermittently driven as a circulation pump with a smaller amount of water supply than the “washing process” to rinse the dishes with a small amount of water. Then, after performing this “shot rinsing process” for a predetermined time, a draining operation is performed to discharge the cleaning water in the cleaning tank 2. After repeating these operations twice, a “final rinsing process” is performed for the purpose of sterilizing effect and shortening the drying time. This “final rinsing process” starts energizing the heater 14 at the start of the process and continues until the thermistor 45 detects a predetermined washing water temperature (for example, 80 ° C.). The draining operation is executed by ending the rotation driving and switching to the opposite rotation, and the cleaning water in the cleaning tank 2 is discharged through the drain hose 20.

  Thereafter, energization of the heater 14 is started, and when the blower 17 is driven and controlled, warm air is blown from the blower pipe 24 into the cleaning tank 2 to execute a “drying process” for drying the dishes. Thereafter, when the “drying process” executed for a predetermined time is finished, the cleaning course is finished.

  On the other hand, in the flowchart of FIG. 5, a portion related to the gist of the present invention is shown in the control contents by the control circuit unit 40, and this will be described below together with related operations. FIG. 5 shows a control routine for the “steam stroke” performed prior to the “cleaning stroke”. In this control routine, first, energization of the heater 34 is started, and at the same time, it is built in the control circuit unit 40. The timer starts counting time (step S1). Then, the water supply valve 26b is opened for a predetermined time (for example, 1 second), and water is supplied into the steam generation unit 28 through the tube 41 and the water supply port 32 (step S2). Thereby, the water flowing into the steam generation unit 29a in the steam generation unit 28 is heated to generate water vapor, and the heated water vapor is passed from the steam discharge port 33 through the tube 43 and the jet port 42. It is supplied into the cleaning tank 2. At this time, since the thermal energy in the steam generation unit 28 is used as the heat of vaporization of water, the temperature detected by the thermistor 36 falls.

  Thereafter, after energization of the heater 34 is started, it is determined whether or not a time corresponding to the set duration of the “steam stroke”, for example, 5 minutes has elapsed (step S3). In a state where five minutes or more have not elapsed since the start of time measurement by the timer, step S4 for determining whether or not the temperature detected by the thermistor 36 has become equal to or higher than a preset reference temperature has a relationship of detected temperature ≧ reference temperature. Repeat until

  When it is determined that the temperature detected by the thermistor 36 is equal to or higher than the reference temperature, the illustrated water supply valve 26b is opened for 1 second (step S5), and after executing step S6 for waiting for 30 seconds, for example. The process returns to step S3. That is, when it is assumed that the water supplied to the steam generation unit 28 has evaporated, the water is newly supplied into the steam generation unit 29a, and thus the heated steam into the cleaning tank 2 is supplied. Supply continues. Further, after the water supply valve 26b is closed, after a further waiting time of 30 seconds, that is, after the temperature detected by the thermistor 36 is reliably lowered to 110 ° C. or less according to the water supply to the steam generation unit 29a, step S3, Since S4 is performed, the situation where the water supply operation by step S5 is performed carelessly can be prevented beforehand, and heated steam can be efficiently generated.

  On the other hand, when it is determined that 5 minutes or more have elapsed after the start of energization of the heater 34 (step S3: YES), the process proceeds to step S7. However, the state in the steam generation unit 28 at this time differs depending on the relationship between the start of energization of the heater 34 and the timing of the start of water supply. If the heater 34 is turned off shortly after the water supply valve 26b is opened, water may remain on the steam generation unit 29a. Therefore, it is determined whether or not 6 minutes have elapsed from the start of the timer (step S7), and when it has elapsed (step S7: YES), it is considered that the surface of the steam generation unit 29a is dry, and the heater 34 is turned on. After executing step S8 for disconnecting electricity, the steam stroke control routine is terminated. Therefore, the “steam stroke” can be ended after drying the steam generation unit 28, at least the steam generation unit 29 a. In this embodiment, among the “steam stroke”, steps S1 to S6 are referred to as “water supply operation”, and steps S7 and S8 are referred to as “drying operation”.

  According to the configuration of the first embodiment described above, the following operations and effects can be achieved. When executing the “steam stroke”, the control circuit unit 40 continuously energizes the heater 34 for a predetermined time (for example, 5 minutes), and in the energization period, the control circuit unit 40 enters the steam generation unit 29 a of the steam generation unit 28. The water supply valve 26b for supplying water is controlled to be opened intermittently at intervals of 30 seconds for 1 second. Therefore, in the “steaming process”, a large amount of heated steam can be supplied into the cleaning tank 2 in a short time, so that the swelling effect (and the peeling effect) of the dirt stuck to the tableware is enhanced, and the process is performed thereafter. It is possible to greatly improve the cleaning efficiency in the “cleaning process”. In the “water supply operation”, the inside of the steam generation unit 29a is heated to a reference temperature or higher by the heater 34, and control is performed to supply water thereto, so that heated steam can be generated continuously and efficiently. It becomes like this.

  After the “water supply operation”, the inside of the steam generation unit 28, in particular, the “drying operation” in which the steam generation unit 29a is completely dried by the heater 34 is executed, so that water remains in the metal steam generation unit 29a. It is possible to reduce a certain time. Therefore, the progress of the corrosion due to the action of the remaining water can be suppressed regardless of the metal used for the material of the steam generation part 29a. As a result, it is possible to prevent the steam generation performance of the steam generation unit 28 from deteriorating due to long-term use.

(Second Embodiment)
The second embodiment of the present invention will be described below with reference to FIG.

  FIG. 6 shows a flowchart, and the contents of the “drying operation” of the steam generating section 29a in the “steam stroke” are different from those of the first embodiment. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and only different points will be described.

  The flowchart of FIG. 6 shows the portion related to the gist of the present invention in the control contents by the control circuit unit 51, and among these, steps S1 to S6 called “water supply operation” are the same as in the first embodiment. Since it is the same control content, description is abbreviate | omitted.

  If it is determined that 5 minutes or more have elapsed after the start of energization of the heater 34 (step S3: YES), the process proceeds to step S9. However, the state in the steam generation unit 28 at this time differs depending on the relationship between the start of energization of the heater 34 and the timing of the start of water supply. When the heater 34 is turned off immediately after the water supply, water may remain on the steam generation unit 29a. Therefore, in step S9, it is determined whether or not the thermistor temperature ≧ drying determination temperature (for example, 120 ° C.). If the detected temperature of the thermistor 36 exceeds the drying determination temperature (step S9: YES), steam generation is performed. It is determined that the surface of the portion 29a is in a dry state, and after executing step S8 for cutting off the heater 34, the steam stroke control routine is terminated. On the other hand, if the detected temperature of the thermistor 36 is equal to or lower than the drying determination temperature (step S9: NO), step S9 is repeatedly executed until the relationship of detected temperature ≧ drying determination temperature is satisfied, and energization of the heater 34 is continued. . Therefore, after confirming that the inside of the steam generation unit 28 is completely dried, the “steam stroke” can be ended.

  According to the configuration of the second embodiment described above, the following operations and effects can be achieved. When executing the “steam stroke”, the control circuit unit 51 energizes the heater 34 continuously for a predetermined time (for example, 5 minutes), and during the energization period, the control circuit unit 51 enters the steam generation unit 29a of the steam generation unit 28. The water supply valve 26b for supplying water is controlled to be opened intermittently at intervals of 30 seconds for 1 second. Therefore, in the “steaming process”, a large amount of heated steam can be supplied into the cleaning tank 2 in a short time, so that the swelling effect (and the peeling effect) of the dirt stuck to the tableware is enhanced, and the process is performed thereafter. It is possible to greatly improve the cleaning efficiency in the “cleaning process”. In the “water supply operation”, the inside of the steam generation unit 29a is heated to a reference temperature or higher by the heater 34, and control is performed to supply water thereto, so that heated steam can be generated continuously and efficiently. It becomes like this. Further, after the “water supply operation”, the “drying operation” in which the steam generation unit 28, in particular, the steam generation unit 29a is completely dried by the heater 34 is executed, so that water remains in the metal steam generation unit 29a. It is possible to reduce the time spent in the damp state. Therefore, the progress of the corrosion due to the action of the remaining water can be suppressed regardless of the metal used for the material of the steam generation part 29a. As a result, it is possible to prevent the steam generation performance of the steam generation unit 28 from deteriorating due to long-term use.

  Further, the “drying operation” determines whether or not the thermistor temperature ≧ the drying determination temperature (for example, 120 ° C.), and executes a control to end when the detected temperature of the thermistor 36 exceeds the drying determination temperature. Therefore, it does not spend more time and energy than necessary for the “drying operation”, and on the contrary, it is an operating condition where the voltage is lower than usual, and even when it takes time to evaporate water, steam generation is ensured. The part 29a can be dried.

(Third embodiment)
A third embodiment of the present invention will be described below with reference to FIG.

  FIG. 7 shows a timing chart, and the timing for performing the drying of the steam generating unit 28 in the cleaning process is different from that of the second embodiment. Hereinafter, the same parts as those in the second embodiment are denoted by the same reference numerals, description thereof will be omitted, and only different points will be described.

  As shown in FIG. 7, this is different from the second embodiment in the content of the cleaning course executed by the control circuit unit 52, and the drying operation of the steam generation unit 28 is not performed at the end of the “steam stroke”. This is executed within the washing water draining operation time after the execution of the cleaning operation of the “cleaning step” and the cleaning operation of the “final rinsing step”. Specifically, the “steam stroke” ends when 5 minutes have elapsed from the start of the stroke, and when the cleaning operation performed by rotating the pump motor 47 forward in the “cleaning stroke” is completed, the pump motor 47 is driven in reverse rotation to perform cleaning. A draining operation for discharging the washing water in the tank 2 is started. At the same time, energization of the heater 34 is started, and the steam generation unit 28 is heated. Then, when a set time (for example, 45 seconds) of the drainage operation elapses, the energization to the heater 34 is also stopped, and the “drying operation” of the steam generation unit 28 is interrupted. Even before the drainage operation time has elapsed, when the thermistor 36 detects the drying determination temperature or higher, the heater 34 is deenergized and the “drying operation” of the steam generating unit 28 is completed.

  In addition, if the drying determination temperature is not detected by the thermistor within the drainage operation time after the cleaning operation in the “cleaning process”, the drainage operation after the cleaning operation in the “final rinse process” is started and the heater 34 is restarted. Start energization. Thereafter, when a set time (for example, 45 seconds) of the drainage operation elapses, the energization to the heater 34 is stopped and the “drying operation” of the steam generation unit 28 is completed. Even if the thermistor 36 detects a temperature equal to or higher than the drying determination temperature even within the set time of the draining operation after the cleaning operation of the “final rinsing process”, the energization to the heater 34 is immediately stopped and the steam generating unit is stopped. The 28 “drying operation” is completed.

  According to the configuration of the third embodiment described above, the following operations and effects can be achieved. When executing the “steam stroke”, the control circuit unit 52 energizes the heater 34 continuously for a predetermined time (for example, 5 minutes), and within the energization time, the steam generation unit 29 a of the steam generation unit 28 is energized. In this configuration, the water supply valve 26b for supplying water is intermittently opened at intervals of 30 seconds for 1 second. Therefore, in the “steaming process”, a large amount of heated steam can be supplied into the cleaning tank 2 in a short time, so that the swelling effect (and the peeling effect) of the dirt stuck to the tableware is enhanced, and the process is performed thereafter. It is possible to greatly improve the cleaning efficiency in the “cleaning process”. In the “water supply operation”, the inside of the steam generation unit 29a is heated to a reference temperature or higher by the heater 34, and control is performed to supply water thereto, so that heated steam can be generated continuously and efficiently. It becomes like this. Further, after the “water supply operation”, the “drying operation” in which the steam generation unit 28, in particular, the steam generation unit 29a is completely dried by the heater 34 is executed, so that water remains in the metal steam generation unit 29a. It is possible to reduce the time spent in the damp state. Therefore, the progress of the corrosion due to the action of the remaining water can be suppressed regardless of the metal used for the material of the steam generation part 29a. As a result, it is possible to prevent the steam generation performance of the steam generation unit 28 from deteriorating due to long-term use.

  Further, the “drying operation” determines whether or not the thermistor temperature ≧ the drying determination temperature (for example, 120 ° C.), and executes a control to end when the detected temperature of the thermistor 36 exceeds the drying determination temperature. Therefore, it does not spend more time and energy than necessary for the “drying operation”, and on the contrary, it is an operating condition where the voltage is lower than usual, and even when it takes time to evaporate water, steam generation is ensured. The part 29a can be dried.

  Furthermore, since the “drying operation” of the steam generation unit 28 is executed within the set time of the drainage operation, the time required for the entire cleaning course is not extended by the time required for the “drying operation”. Further, since the heater 14 is not energized within the set time of the drainage operation, for example, the “drying operation” in the steam generating unit 29a is surely performed without flowing a current of 15 amperes or more which is an allowable current. Can be implemented.

  Furthermore, after the water supply operation by the last electromagnetic valve 26 in the cleaning course is performed, that is, by performing the “drying operation” of the steam generation unit 29a within the drainage operation setting time after the “final rinsing process”, the cleaning course is performed. Even if water leaks to the side of the water supply valve 26b and water enters the steam generation unit 28 via the tube 41 during the water supply operation by the water supply valve 26a, the steam generation unit 29a is reliably dried. be able to.

  In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and can be modified or expanded as described below, for example. Further, when the temperature detected by the thermistor 36 does not exceed the drying determination temperature within the drainage operation time after the cleaning operation of the “final rinsing process”, the energization to the heater 34 is continued even after the drainage operation is completed. It is good also as control which starts the "drying process" of the steam generation part 29a, after the detection temperature of the thermistor 36 exceeds dry determination temperature. Considering the energy efficiency of the energy required for heating by the heater 34 and the drying effect, the “drying operation” of the steam generation unit 29a is performed within the drainage operation time of the “cleaning process” or “final rinsing process” with a long drainage time. Although it is advantageous to perform this, control may be performed to dry the steam generation unit 39a within the drainage operation setting time after the washing operation of the two “shot rinsing steps”.

  Furthermore, the drying determination temperature of the steam generation unit 29a by the thermistor 36 may be the same as the reference temperature (110 ° C.) for water supply control.

  The 1st water supply means and the 2nd water supply means may be comprised from one solenoid valve and one switching valve which are shared.

  In the first to third embodiments, an example in which the steam generation unit 29a is configured from a container has been shown. This steam generation unit is a metal heating dish and a heat-resistant material different from the heating dish. It is good also as a structure covered with.

1 is a longitudinal sectional view of a dishwasher according to an embodiment of the present invention. Vertical section of steam generation unit Electrical block diagram Timing chart showing contents of cleaning course of first embodiment The flowchart which shows the control content of the steam stroke of a 1st Example. The flowchart which shows the control content of the steam process of 2nd Example. Timing chart showing contents of cleaning course of third embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tableware washing machine 2 Washing tank 3 Outer box 4 Lower door 5 Upper door 9, 11 Spray nozzle (cleaning means)
14 Heater (heat source for generating hot water)
26 Solenoid valve 26a Water supply valve (first water supply means)
26b Water supply valve (second water supply means)
28 Steam Generation Unit 29 Main Body 29a Steam Generation Unit 29b Stepped Part 30 Lid 31 Heat Resistant Packing 32 Water Supply Port 33 Steam Discharge Port 34 Heater (Heat Generation Heat Source)
36 thermistor (temperature sensor)
40, 51, 52 Control circuit unit (control means)
41 Tube 42 Spout 43 Tube 44 Cover member 44a Opening

Claims (4)

An outer box, and a cleaning tank that is provided in the outer box and accommodates an object to be cleaned;
A first water supply means for cleaning water into the cleaning tank;
Drainage means for discharging the cleaning water in the cleaning tank;
A cleaning means for cleaning an object to be cleaned in the cleaning tank;
Steam generating means for generating steam to be supplied into the cleaning tank;
A second water supply means for supplying water to the steam generating means;
Control means for executing a cleaning course including a steam stroke performed by controlling the steam generation means, and the steam generation means is provided in a water supply port connected to a second water supply means, and in the cleaning tank. A steam outlet communicating with the spout, a metal steam generator,
It is composed of a steam generation heat source arranged to be able to heat the evaporation generation unit,
A dishwasher, wherein a drying operation is executed after the last water supply operation by the second water supply means in the steam stroke of the control means.   2. A dish washing apparatus according to claim 1, further comprising: a drying detection unit configured to detect a dry state of the steam generation unit, and when the dry detection unit detects the dry state, the energization to the steam generation heat source is stopped. Machine.   2. The dishwasher according to claim 1, further comprising a hot water generating heat source, wherein when the heat source is not energized, the steam generating heat source is energized to perform a drying operation.   The dishwasher according to claim 1, wherein after the last water supply operation by the first water supply means in the cleaning course, the steam generation heat source is energized to perform the drying operation.

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