JP2011010798A - Dishwasher - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dishwasher for appropriately performing washing according to dirt of washed objects over a long period by preventing an optical sensor from being short-lived.SOLUTION: A storage part for storing washing water is formed at the lower part of a cleaning tank 2 for housing materials to be washed. A plurality of washing nozzles 3, 4, 7, and 5 are provided inside the cleaning tank 2. The respective washing nozzles 3, 4, 7, and 5 are successively supplied with washing water stored in the storage part. A turbidity detection part 60 is provided at a position higher than the highest level of the washing water storable in the storage part inside the cleaning tank 2. The turbidity detection part 60 detects the turbidity of washing water supplied with one washing nozzles 5 out of the plurality of washing nozzles 3, 4, 7, and 5. On the basis of the turbidity of the washing water detected, a period during which the washing nozzle 5 is supplied with the washing water is determined and, after determination, the turbidity detection part is operated only for the period in which the washing nozzle 5 is supplied with washing water.

Description

  The present invention relates to a dishwasher for washing dishes.

  There is a dishwasher equipped with an optical sensor for detecting the turbidity (permeability) of washing water used for washing dishes. In this dishwasher, control of each process such as washing and rinsing is performed in accordance with, for example, a detection result by an optical sensor (for example, Patent Document 1 and Patent Document 2).

  The dishwasher described in Patent Literature 2 is connected to a plurality of washing nozzles disposed in a washing tank for storing tableware and having jet holes for jetting washing water, and a plurality of washings connected to the downstream side of the washing pump. A water distribution means having a plurality of outflow portions communicating with each of the nozzles, and a valve body for switching the outflow portions so as to supply cleaning water to at least one of the plurality of cleaning nozzles built in the water distribution means, This includes a moving position of the valve body and detection means for detecting the turbidity of the washing water.

JP-A-8-89469 JP 2006-263025 A

  However, in the tableware washing machine of patent document 1, since the detection means for detecting the turbidity of the washing water is continuously operated, the life of the optical sensor may be shorter than the life expected in advance.

  An object of the present invention is to provide a dishwasher that suppresses the shortening of the lifetime of the turbidity detection unit and can appropriately perform cleaning according to the contamination of the object to be cleaned over a long period of time.

  (1) A dishwasher according to the present invention is a dishwasher that jets washing water to wash an object to be washed, and has a storage part that stores the washing water, and a washing tank that houses the object to be washed; A plurality of cleaning nozzles provided in the cleaning tank and the cleaning water stored in the reservoir are sequentially supplied to the plurality of cleaning nozzles, and the cleaning water is sprayed from the cleaning nozzles onto the object to be cleaned contained in the cleaning tank. The water supply unit is provided at a position higher than the highest water level of the cleaning water that can be stored in the storage unit in the cleaning tank, and has an optical sensor and is supplied to at least one of the plurality of cleaning nozzles. A turbidity detection unit for detecting information on the turbidity of the cleaning water, and adjusting the cleaning conditions of the object to be cleaned based on the information on the turbidity of the cleaning water detected by the turbidity detection unit, and at least one Cleaning water is supplied to the cleaning nozzle To determine the period in which a control unit for controlling the period of operation of the turbidity detection unit.

In this dishwasher, washing water is stored in a storage part of the cleaning tank. The cleaning water stored in the storage unit is sequentially supplied to each of the plurality of nozzles in the cleaning tank by the diversion supply unit. Washing water is jetted from each cleaning nozzle onto the object to be cleaned contained in the cleaning tank, and the object to be cleaned is cleaned. In this case, information on the turbidity of the washing water supplied to at least one washing nozzle among the plurality of washing nozzles is detected by the turbidity detection unit. Based on the information about the turbidity of the washing water detected by the turbidity detection unit, the turbidity is detected in an optimum period for detecting the turbidity by determining the period during which the washing water is supplied to the at least one washing nozzle. In addition, the cleaning conditions for the object to be cleaned are adjusted.

  Here, the turbidity detection part is provided in a position higher than the maximum water level of the cleaning water that can be stored in the storage part in the cleaning tank. Therefore, when no cleaning water is supplied to the at least one cleaning nozzle, there is no cleaning water in the turbidity detection unit. Thereby, it is reduced that dirt, such as scale or oil, adheres to a turbidity detection part. Therefore, the detection error of the turbidity of the washing water is reduced, and the turbidity of the washing water can be accurately detected over a long period. As a result, the period during which the cleaning water is supplied to the at least one cleaning nozzle can be accurately determined, and the cleaning conditions for the object to be cleaned can be appropriately adjusted according to the contamination of the object to be cleaned.

  (2) The control unit may operate the turbidity detection unit only during a period in which cleaning water is supplied to at least one cleaning nozzle.

  Since the turbidity of the cleaning water cannot be detected during the period when the cleaning water is not supplied to the at least one cleaning nozzle, it is not necessary to operate the turbidity detection unit. By not operating the turbidity detection unit in the period, the total operation time of the turbidity detection unit can be shortened. Thereby, the short life of said turbidity detection part can be prevented.

  (3) The control unit has at least 1 based on the difference between the turbidity of each cleaning water and the reference value calculated based on the turbidity in a plurality of periods when the cleaning water is supplied to the plurality of cleaning nozzles. You may determine the period when wash water is supplied to one washing nozzle.

  In this case, the reference value is calculated based on the information about the turbidity of the cleaning water detected by the turbidity detecting unit during the period in which the cleaning water is supplied to the plurality of cleaning nozzles. Then, a period in which the cleaning water is supplied to the at least one cleaning nozzle is determined based on the difference between the calculated reference value and the turbidity of the cleaning water. Thereby, the determination precision of said period improves.

  (4) The control unit supplies the cleaning water to at least one cleaning nozzle based on the turbidity fluctuation width of the cleaning water detected by the turbidity detection unit during a period in which the cleaning water is supplied to the plurality of cleaning nozzles. The period to be performed may be determined.

  In this case, the turbidity fluctuation width within a certain period is continuously measured during the period in which the washing water is supplied to the plurality of washing nozzles. Then, the period during which the cleaning water is supplied to the at least one cleaning nozzle is determined based on the measured turbidity fluctuation width. Thereby, the determination precision of said period improves.

  According to the present invention, it is possible to accurately determine the period during which cleaning water is supplied to at least one cleaning nozzle, and shorten the life of the turbidity detection unit by minimizing the operation of the turbidity detection unit. Is prevented. Therefore, it is possible to appropriately perform cleaning according to the contamination of the object to be cleaned over a long period of time.

The front view which shows the structure of the dishwasher which concerns on one embodiment of this invention The side view which shows the structure of the dishwasher which concerns on one embodiment of this invention The figure for demonstrating the several flow path connected to the water diversion mechanism of FIG. Flow chart showing the outline of operation of the dishwasher 1 is an assembled perspective view of the turbidity detection unit of FIG. Vertical section of the turbidity detector in FIG. Block diagram showing the configuration of the control system of the dishwasher Graph showing an example of the detection result of the turbidity detector in the general case of the cleaning process A graph showing an example of the detection result of the turbidity detector when there is solid matter adhesion in the cleaning process Flow chart showing a control example of the dishwasher in the washing process and the rinsing process Flow chart showing a control example of the dishwasher in the washing process and the rinsing process Flow chart showing another example of control of dishwasher in washing process and rinsing process

  Hereinafter, a dishwasher according to an embodiment of the present invention will be described with reference to the drawings. In the following description, a liquid used for cleaning and rinsing an object to be cleaned such as tableware is referred to as cleaning water.

(1) Configuration of Dishwasher FIGS. 1 and 2 are a front view and a side view showing a configuration of a dishwasher according to an embodiment of the present invention. In the front view of FIG. 1, a part of the front of the dishwasher 1 is cut away. Moreover, in the side view of FIG. 2, the inside of the dishwasher 1 is permeate | transmitted and illustrated.

  As shown in FIGS. 1 and 2, the dishwasher 1 includes a housing 1a. A door 16 (FIG. 2) that can be opened and closed is provided on the front surface of the housing 1a. A window portion 16 a (FIG. 2) is formed in a part of the door 16. A cleaning tank 2 for cleaning the object to be cleaned 10 such as tableware is provided in the housing 1a.

  An upper table basket 8 is provided at the upper stage of the cleaning tank 2 so as to be movable in the front-rear direction. The upper table basket 8 has a left accommodating portion 8 a provided on one side of the cleaning tank 2 and a right accommodating portion 8 b provided on the other side of the cleaning tank 2. The left accommodating portion 8a is provided at a position lower than the right accommodating portion 8b.

  A lower table basket 9 is provided at the lower part of the cleaning tank 2 so as to be movable in the front-rear direction. The lower table basket 9 has a left accommodating portion 9 a provided on one side of the cleaning tank 2 and a right accommodating portion 9 b provided on the other side of the cleaning tank 2. The left accommodating portion 9a and the right accommodating portion 9b are provided at the same height.

  Various objects to be cleaned 10 are accommodated in the left accommodating portion 8a and the right accommodating portion 8b of the upper tableware basket 8, and the left accommodating portion 9a and the right accommodating portion 9b of the lower tableware basket 9.

  A substantially cross-shaped fixed cleaning nozzle 5 is disposed on the back surface of the cleaning tank 2. The fixed cleaning nozzle 5 has a vertical nozzle portion 5a extending in the vertical direction and a horizontal nozzle portion 5b extending in the horizontal direction at a substantially central portion of the vertical nozzle portion 5a. The upper end portion of the vertical nozzle portion 5a is bent in the lateral direction toward the other side surface of the cleaning tank 2 to form a bent portion 5c. A plurality of liquid ejection ports 20a are formed in the bent portion 5c.

  Moreover, the turbidity detection part 60 is provided immediately above the upper end part of the vertical nozzle part 5a. Details of the turbidity detection unit 60 will be described later.

On one side of the cleaning tank 2, a water conduit 6 is attached so as to extend forward from the lateral nozzle portion 5 b of the fixed cleaning nozzle 5. A rotary cleaning nozzle 7 is attached to the tip of the water conduit 6 so as to be rotatable around the vertical axis. The rotary cleaning nozzle 7 has blade portions extending in one direction and in the opposite direction from the rotation center, and a plurality of liquid injection ports (not shown) are formed on the upper surfaces of the blade portions. The rotary cleaning nozzle 7 is disposed below the left accommodating portion 8 a of the upper table basket 8. In addition, a plurality of liquid injection ports 20 b are formed in the horizontal nozzle portion 5 b on the other side surface of the cleaning tank 2.

  Rotating cleaning nozzles 3 and 4 are attached to the bottom of the cleaning tank 2 so as to be rotatable around the vertical axis. Each of the rotary cleaning nozzles 3 and 4 has blade portions extending in one direction and in the opposite direction from the rotation center, like the rotary cleaning nozzle 7, and a plurality of liquid injection ports (not shown) are formed on the upper surfaces of these blade portions. ) Is formed. The rotary cleaning nozzle 3 is disposed below the left accommodating portion 9a of the lower tableware basket 9, and the rotational cleaning nozzle 4 is disposed below the right accommodating portion 9b of the lower tableware basket 9.

  As shown in FIG. 2, a reservoir 12 is formed on the front side of the washing tub 2 below the lower table basket 9 to temporarily store washing water used for washing or rinsing the article to be washed 10. .

  One end of the water supply pipe 31 is connected to the vicinity of the lower end of the back surface of the cleaning tank 2. The water supply pipe 31 extends to the outside of the housing 1a, and the other end is connected to a water pipe (not shown). A water supply valve 31 a is inserted in the water supply pipe 31 inside the housing 1 a. By opening the water supply valve 31a, tap water is introduced into the cleaning tank 2 as cleaning water. The cleaning water introduced into the cleaning tank 2 is stored in the storage unit 12.

  The reservoir 12 is provided with a heater 14 for heating the stored cleaning water and for heating the atmosphere inside the cleaning tank 2. Further, the storage unit 12 is provided with a temperature sensor 17 that detects the temperature of the stored cleaning water and the temperature of the atmosphere inside the cleaning tank 2.

  A drain port 12 a is formed at the bottom of the storage unit 12. A leftover filter 13 for collecting the leftovers removed from the object to be cleaned 10 is detachably mounted immediately above the drain port 12a. In the present embodiment, the leftovers refer to solid substances in the dirt removed from the object to be cleaned 10 by washing or rinsing.

  A washing water introduction / derivation portion G is formed at the lower portion of the drain port 12a. A pump 11 is connected to the cleaning water introduction / derivation section G via a pipe 11a. Thereby, the internal space of the pump 11 communicates with the internal space of the cleaning water introduction / derivation part G. The pump 11 is provided with a drain pipe 32 extending outside the housing 1a and a water diversion mechanism 15. In the present embodiment, a reversible rotary pump is used as the pump 11. The drain pipe 32 has a trap structure (not shown).

  A drying mechanism 72 is provided on the side of the pump 11. The drying mechanism 72 includes, for example, a fan and supplies gas from the back surface of the cleaning tank 2 to the inside of the cleaning tank 2 through a gas introduction pipe (not shown). Thereby, an air flow is generated in the internal space of the cleaning tank 2 in the drying process of the object to be cleaned 10 described later.

  A plurality of flow paths are connected to the water diversion mechanism 15. The plurality of flow paths will be described. FIG. 3 is a view for explaining a plurality of flow paths connected to the water diversion mechanism 15 of FIG.

As shown by a thick alternate long and short dash line in FIG. 3, the first, second, third, and fourth flow paths Ra, Rb, Rc, Rd are connected to the water diversion mechanism 15. The first flow path Ra connects the water diversion mechanism 15 and the rotary cleaning nozzle 3. The first flow path Ra is used to supply the cleaning water in the water diversion mechanism 15 to the rotary cleaning nozzle 3.

  The second flow path Rb connects the water diversion mechanism 15 and the rotary cleaning nozzle 4. The second flow path Rb is used to supply the cleaning water in the water splitting mechanism 15 to the rotary cleaning nozzle 4.

  The third flow path Rc is formed inside the fixed cleaning nozzle 5. Specifically, the third flow path Rc connects the water diversion mechanism 15 and the turbidity detection unit 60 through the vertical nozzle unit 5 a of the fixed cleaning nozzle 5. The third flow path Rc connects the water diversion mechanism 15 and the plurality of liquid ejection ports 20a through the vertical nozzle portion 5a and the bent portion 5c of the fixed cleaning nozzle 5. Further, the third flow path Rc connects the water diversion mechanism 15 and the plurality of liquid ejection ports 20b through the vertical nozzle portion 5a of the fixed cleaning nozzle 5 and the horizontal nozzle portion 5b on the other side surface of the cleaning tank 2. The third flow path Rc is used to supply the cleaning water in the water diversion mechanism 15 to the turbidity detection unit 60 and the plurality of liquid injection ports 20a and 20b of the fixed cleaning nozzle 5.

  The fourth flow path Rd is also formed inside the fixed cleaning nozzle 5. Specifically, the fourth flow path Rd includes the vertical nozzle portion 5 a of the fixed cleaning nozzle 5, the horizontal nozzle portion 5 b on one side of the cleaning tank 2, and the water distribution mechanism 15 and the rotary cleaning nozzle 7 through the water conduit 6. And connect. The fourth flow path Rd is used to supply the cleaning water in the water splitting mechanism 15 to the rotary cleaning nozzle 7.

  A valve body is provided inside the water diversion mechanism 15. In the present embodiment, the valve body selectively connects the internal space of the water diversion mechanism 15 to any one of the first to fourth flow paths Ra to Rd according to the operation of the pump 11.

  Specifically, when the valve body moves from a state where the motor of the pump 11 is stopped to a state where the motor of the pump 11 rotates in one direction, the valve body and the first to first The communication state with the four flow paths Ra to Rd is switched. Thus, when the motor of the pump 11 intermittently rotates in one direction, the first, second, third, and fourth flow paths Ra, Rb, Rc each time the pump 11 operates from the stopped state. , Rd are communicated with the internal space of the water diversion mechanism 15 in this order.

  In the dishwasher 1, when the object to be cleaned 10 is washed or rinsed, first, the water supply valve 31 a is opened, so that the cleaning water (tap water) enters the reservoir 12 from the water supply pipe 31 through the bottom surface of the cleaning tank 2. Is supplied.

  After a predetermined amount of washing water is stored in the storage unit 12, the motor of the pump 11 rotates in one direction. Accordingly, the wash water stored in the storage unit 12 is sucked by the pump 11 and is pumped to the water diversion mechanism 15. In the water diversion mechanism 15, the wash water pumped from the pump 11 is selectively supplied to any one of the first to fourth flow paths Ra to Rd by the valve body.

  When the cleaning water is supplied to the first flow path Ra, the cleaning water is sprayed from the liquid injection port of the rotary cleaning nozzle 3 toward the object 10 to be cleaned accommodated in the left accommodating portion 9a of the lower tableware basket 9. .

  When the cleaning water is supplied to the second flow path Rb, the cleaning water is sprayed from the liquid injection port of the rotary cleaning nozzle 4 toward the object to be cleaned 10 stored in the right storage portion 9b of the lower tableware basket 9. .

  When the cleaning water is supplied to the fourth flow path Rd, the cleaning water is sprayed from the liquid injection port of the rotary cleaning nozzle 7 toward the object 10 to be cleaned stored in the left storage portion 8a of the upper tableware basket 8. .

When cleaning water is ejected from the rotary cleaning nozzles 3, 4, and 7, the rotary cleaning nozzles 3, 4, and 7 rotate about the vertical axis due to a reaction force that acts on the blades as the cleaning water is injected. Thereby, the jet direction of the cleaning water from the rotary cleaning nozzle 4 to the object to be cleaned 10 continuously changes.

  When the cleaning water is supplied to the third flow path Rc, the cleaning water flows from the liquid injection ports 20a and 20b of the fixed cleaning nozzle 5 toward the object to be cleaned 10 stored in the right storage portion 8b of the upper tableware basket 8. Be injected. Moreover, washing water is supplied to the turbidity detection unit 60, and the turbidity of the washing water is detected. Details will be described later.

  In the dishwasher 1 described above, when the washing or rinsing of the object to be cleaned 10 is completed, the motor of the pump 11 rotates in the reverse direction. As a result, the cleaning water stored in the storage unit 12 and the cleaning water remaining in the water diversion mechanism 15 are sucked by the pump 11 through the drain port 12a and the cleaning water introduction / derivation unit G, and the outside of the cleaning tank 2 through the drain pipe 32. To be discharged.

(2) Outline of Operation of Dishwasher An outline of operation of the dishwasher 1 will be described. FIG. 4 is a flowchart showing an outline of the operation of the dishwasher 1.

  As shown in FIG. 4, first, the cleaning water remaining in the cleaning tank 2 is discharged, and tap water is supplied from the water supply pipe 31 into the storage unit 12 by opening the water supply valve 31a (step S1: drainage). / Water supply process).

  Next, cleaning water is obtained by adding detergent to the tap water supplied into the cleaning tank 2, and the cleaning water is pumped to the first to fourth flow paths Ra to Rd by the pump 11. Thereby, cleaning water is jetted from the rotary cleaning nozzles 3, 4, 7 and the fixed cleaning nozzle 5 to the object to be cleaned 10, and the object to be cleaned 10 is cleaned (step S 2: cleaning process).

  In this case, the cleaning water sprayed on the article to be cleaned 10 flows into the storage unit 12 through the wall surface of the cleaning tank 2 and is stored in the storage unit 12 again. The cleaning water stored in the storage unit 12 is again pumped by the pump 11 to the first to fourth flow paths Ra to Rd, and sprayed from the nozzles 3, 4, 5, and 7 to the object to be cleaned 10. As described above, the cleaning water circulates inside the cleaning tank 2 when the object to be cleaned 10 is cleaned.

  When the cleaning of the object to be cleaned 10 is completed, the cleaning water used for cleaning the object to be cleaned 10 is discharged through the drain pipe 32 by the pump 11. And tap water is again supplied to the storage part 12 of the washing tank 2 by opening the water supply valve 31a (step S3: drainage / water supply process).

  Next, the tap water supplied into the cleaning tank 2 is pumped to the first to fourth flow paths Ra to Rd by the pump 11 as cleaning water. As a result, cleaning water is sprayed from the nozzles 3, 4, 5, and 7 to the object 10 to be cleaned, and the object 10 to be cleaned is rinsed (step S4: rinsing step).

  When rinsing of the object to be cleaned 10 is finished, the cleaning water used for rinsing is discharged through the drain pipe 32 by the pump 11. And tap water is again supplied to the storage part 12 of the washing tank 2 by opening the water supply valve 31a (step S5: drainage / water supply process).

  Next, by operating the heater 14, the tap water stored in the storage unit 12 is heated to a predetermined temperature. And the heated tap water is pumped by the pump 11 to 1st-4th flow path Ra-Rd as washing water. Thus, the cleaning water heated to a predetermined temperature is sprayed from the nozzles 3, 4, 5, and 7 to the object to be cleaned 10, and the object to be cleaned 10 is rinsed by heating (step S6: rinsing step).

In this case, the object to be cleaned 10 can be sterilized by heat, and the drying efficiency of the object to be cleaned 10 in the subsequent drying process can be increased.

  When the heat rinsing of the article to be cleaned 10 is finished, the cleaning water used for the heat rinsing is discharged through the drain pipe 32 by the pump 11 (step S7: drainage process).

  Finally, the operation of the pump 11 is stopped and the drying mechanism 72 of FIG. 2 is operated. The drying mechanism 72 generates an air flow in the internal space of the cleaning tank 2. Thereby, the atmosphere heated to a predetermined temperature by the heater 14 circulates inside the cleaning tank 2. Thereby, the to-be-cleaned object 10 is dried (step S8: drying process). A series of operation | movement in the dishwasher 1 is complete | finished when drying of the to-be-cleaned object 10 is completed.

  Although not mentioned above, actually, the cleaning water is heated to a predetermined temperature by the heater 14 also in the cleaning process of step S2. On the other hand, in the rinsing process of step S4, the cleaning water is not heated by the heater 14. However, by adjusting the cleaning conditions, the cleaning water may be heated to a predetermined temperature by the heater 14 even in the rinsing process of step S4.

  Of the series of operations described above, the number of times of the cleaning process in step S2 and the rinsing process in steps S3 and S4 can be appropriately changed according to the turbidity of the cleaning water detected by the turbidity detection unit 60. Further, in the cleaning process and the rinsing process, the temperature of the cleaning water and the cleaning time or the rinsing time can be appropriately changed according to the turbidity of the cleaning water detected by the turbidity detection unit 60. Control of the dishwasher 1 according to the turbidity of the washing water will be described later.

(3) Details of Turbidity Detection Unit Details of the turbidity detection unit 60 will be described. 5 is an assembled perspective view of the turbidity detection unit 60 of FIG. 1, and FIG. 6 is a longitudinal sectional view of the turbidity detection unit 60 of FIG.

  As shown in FIGS. 5 and 6, the turbidity detection unit 60 mainly includes a lower cover 610, a packing 620, a sensor housing cover 630, a sensor support case 640, an upper cover 650, a printed circuit board 64P, an optical sensor 64, and turbidity detection. It consists of a nozzle 5x.

  The lower cover 610 constitutes a part of the ceiling surface in the cleaning tank 2 of FIG. That is, the ceiling surface of the cleaning tank 2 is formed so that a part thereof protrudes downward. An opening 611 is formed at the center of the lower cover 610. Further, two screw holes 612 are formed in the lower cover 610 in the vicinity of the opening 611.

  As a material for the back surface, the side surface, the bottom surface, and the ceiling surface of the cleaning tank 2 (FIG. 1), for example, a polypropylene (PP) resin having a light shielding property is used. In addition, polypropylene (PP) resin is also used as a material of a portion excluding the window portion 16a (FIG. 2) of the door 16 constituting the front surface of the cleaning tank 2 (FIG. 1). On the other hand, polymethylpentene (PMP) resin having translucency is used as the material of the window portion 16a (FIG. 2) of the door 16. Thereby, the user of the dishwasher 1 can visually recognize the inside of the washing tub 2 from the window portion 16 a of the door 16.

  When assembling the turbidity detection unit 60, the packing 620 is attached along the inner edge of the opening 611 of the lower cover 610. In this state, the sensor housing cover 630 having a substantially ship shape is fitted into the opening 611 of the lower cover 610 via the packing 620. As a material of the sensor housing cover 630, for example, polymethylpentene (PMP) resin is used. In this case, the sensor housing cover 630 has translucency.

A housing space 630 </ b> S for housing the sensor support case 640 is formed at the center of the sensor housing cover 630. In addition, two through holes 639 are formed in the sensor housing cover 630 in the vicinity of the housing space 630S.

  With the sensor housing cover 630 fitted into the lower cover 610, screws N are attached to the two screw holes 612 of the lower cover 610 through the two through holes 639 of the sensor housing cover 630. Thereby, the sensor housing cover 630 is securely fixed to the lower cover 610. Further, the water tightness between the sensor housing cover 630 and the lower cover 610 is ensured by the packing 620. As shown in FIG. 6, a concave portion 631 having a rectangular cross section recessed upward is formed at the center of the bottom surface of the sensor housing cover 630 that forms the housing space 630 </ b> S.

  A printed circuit board 64P and an optical sensor 64 are attached to the sensor support case 640. In the present embodiment, a transmissive optical sensor is used as the optical sensor 64. The optical sensor 64 includes a light emitting element 64a made of a light emitting diode and a light receiving element 64b made of a photodiode. The terminals of the light emitting element 64a and the light receiving element 64b are connected to the printed board 64P.

  The sensor support case 640 to which the printed circuit board 64P and the optical sensor 64 are attached is accommodated in the accommodation space 630S of the sensor accommodation cover 630. In this state, the light emitting element 64a and the light receiving element 64b supported by the sensor support case 640 face each other with the concave portion 631 of the sensor housing cover 630 interposed therebetween.

  The upper cover 650 is attached so as to press down the upper end of the sensor support case 640. Thereby, the sensor support case 640 is positioned and the sensor support case 640 is fixed to the sensor housing cover 630. Thereby, the light emitting element 64a and the light receiving element 64b are also positioned.

  The upper surface of the upper cover 650 is in contact with the ceiling surface of the housing 1 a that covers the cleaning tank 2. Thereby, each structural member of the turbidity detection part 60 is fixed reliably.

  As shown in FIG. 6, a turbidity detection nozzle 5 x extending in the vertical direction toward the turbidity detection unit 60 is attached to the upper end of the fixed cleaning nozzle 5 of FIGS. 1 to 3. The internal space of the turbidity detection nozzle 5x constitutes a part of the third flow path Rc in FIG.

  The tip of the turbidity detection nozzle 5x is positioned so as to face the concave portion 631 of the sensor housing cover 630. Accordingly, when the cleaning water is supplied to the third flow path Rc, the cleaning water is continuously discharged upward from the turbidity detection nozzle 5x, so that the cleaning water is discharged into the concave portion 631. Filled. The cleaning water filled in the concave portion 631 is sequentially replaced with the cleaning water discharged from the turbidity detection nozzle 5x.

  In this state, the optical sensor 64 is driven. As described above, the sensor housing cover 630 has translucency. Therefore, the light generated by the light emitting element 64a is received by the light receiving element 64b through the side wall of the concave portion 631 of the sensor housing cover 630 and the cleaning water filled in the concave portion 631.

  Thereby, when the light emission amount of the light emitting element 64a is constant, the light reception amount of the light receiving element 64b changes according to the dirt (turbidity) of the cleaning water filled in the concave portion 631. Thereby, the turbidity of the washing water is detected based on the voltage value of the light reception signal output from the light receiving element 64b.

  When the supply of the washing water to the third flow path Rc is stopped, the washing water filled in the concave portion 631 flows down along the inner peripheral surface and the like.

(4) Features of turbidity detection unit (4-a) In dishwasher 1 according to the present embodiment, turbidity detection unit 60 is provided at a position higher than the highest water level of the wash water stored in storage unit 12. It has been.

  Thus, when the cleaning water is supplied to the channels Ra, Rb, Rd other than the third channel Rc, the turbidity detection portion (concave portion 631) of the cleaning water in the turbidity detection unit 60 is cleaned. No water contact. Further, when the washing water is discharged from the washing tank 2, no washing water remains in the turbidity detection part (concave part 631) of the washing water in the turbidity detection part 60.

  Accordingly, it is possible to prevent water scale and oil from adhering to the concave portion 631 of the sensor housing cover 630. As a result, the detection error of the turbidity of the washing water is reduced, and the turbidity of the washing water can be accurately detected over a long period.

  Moreover, the turbidity detection part 60 is provided in the inside of the washing tank 2, and maintenance is easy. Therefore, even if the concave portion 631 is soiled, the user can easily remove the soiling.

  In the dishwasher 1, the turbidity detection unit 60 detects the turbidity of the washing water supplied to the third flow path Rc. In the washing step and the rinsing step, it is possible to accurately detect the communication state between the internal space of the water separation mechanism 15 and the third flow path Rc based on the detection result of the turbidity detection unit 60. Details will be described later.

  (4-b) As described above, in the turbidity detection unit 60, cleaning water is discharged from the turbidity detection nozzle 5x to the concave portion 631 of the sensor housing cover 630. The turbidity of the cleaning water is detected by the optical sensor 64 by filling the concave portion 631 with the cleaning water.

  Here, the concave portion 631 is arranged so that the turbidity detection nozzle 5x is arranged in the vertical direction and faces the tip of the turbidity detection nozzle 5x. Thereby, the bottom portion 632 of the concave portion 631 extends along the horizontal plane and faces downward. In this state, when cleaning water is discharged in the vertical direction from the turbidity detection nozzle 5x to the concave portion 631, a substantially uniform water pressure is applied to the bottom surface 632 of the concave portion 631. Thereby, when bubbles are mixed in the cleaning water introduced into the concave portion 631, the bubbles are uniformly pushed downward from the concave portion 631 by water pressure. Therefore, when cleaning water is continuously discharged to the concave portion 631, almost no gas phase such as bubbles remains in the concave portion 631.

  In this case, since there is no gas phase in the cleaning water introduced between the light emitting element 64a and the light receiving element 64b, the detection error of the turbidity of the cleaning water is reduced.

  When the turbidity detection nozzle 5x is arranged in the horizontal direction and the sensor housing cover 630 is arranged so that the concave portion 631 faces the tip of the turbidity detection nozzle 5x, the washing water from the turbidity detection nozzle 5x to the concave portion 631. Is discharged, the water pressure applied to the bottom surface 632 along the vertical direction of the concave portion 631 is difficult to be uniform due to the influence of gravity. Therefore, when bubbles are mixed in the cleaning water introduced into the concave portion 631, the bubbles may move upward and stay inside the concave portion 631.

  Therefore, the turbidity detection nozzle 5x and the sensor accommodation cover 630 are arranged such that the turbidity detection nozzle 5x is arranged in the vertical direction and the concave portion 631 faces the tip of the turbidity detection nozzle 5x. It is preferable. As a result, the turbidity detection error is reduced as described above.

  In the case where bubbles mixed in the cleaning water hardly affect the turbidity detection error, the turbidity detection nozzle 5x is disposed in the horizontal direction, and the concave portion 631 of the sensor housing cover 630 is the turbidity detection nozzle 5x. You may arrange | position so that the front-end | tip part may be opposed. Alternatively, the turbidity detection nozzle 5x may be disposed so as to be inclined with respect to the vertical direction, and the sensor housing cover 630 may be disposed such that the concave portion 631 faces the tip of the turbidity detection nozzle 5x.

  Even in this case, the turbidity detection unit 60 is provided at a position higher than the maximum water level of the cleaning water stored in the storage unit 12, so that the cleaning water flows in the channels Ra, Rb, When supplied to Rd, the washing water does not contact the concave portion 631. Further, even when the cleaning water is discharged from the cleaning tank 2, the cleaning water does not remain in the concave portion 631. Accordingly, it is possible to prevent water scale and oil from adhering to the concave portion 631 of the sensor housing cover 630.

  (4-c) As described above, the window portion 16a of the door 16 (FIG. 2) constituting the front surface of the cleaning tank 2 (FIG. 1) has translucency. Thereby, external light enters the cleaning tank 2 from the window portion 16a with the door 16 of FIG. 2 closed. In this case, there is a possibility that the detection accuracy of the optical sensor 64 may be reduced by disturbance light when detecting the turbidity of the washing water.

  On the other hand, in the turbidity detection unit 60, the concave portion 631 where the turbidity of the washing water is detected is surrounded by the lower cover 610. As described above, the lower cover 610 constitutes a part of the ceiling surface of the cleaning tank 2, and the ceiling surface has light shielding properties.

  Thereby, even when external light enters the inside of the cleaning tank 2 with the door 16 closed, the light is prevented from entering the concave portion 631 inside the lower cover 610. As a result, it is possible to prevent the detection accuracy of the optical sensor 64 from being lowered due to ambient light when detecting the turbidity of the washing water.

  (4-d) When the inner surface of the concave portion 631 of the sensor housing cover 630 that receives the cleaning water has water repellency, the discharge of the cleaning water from the turbidity detection nozzle 5x to the concave portion 631 is completed. The cleaning water tends to adhere as droplets to the inner surface. When the droplet attached to the inner surface of the concave portion 631 is dried, dirt contained in the droplet adheres unevenly on the inner surface of the concave portion 631. In this case, the turbidity detection by the optical sensor 64 becomes unstable because the inner surface of the concave portion 631 is soiled unevenly.

  Therefore, the surface of the concave portion 631 of the sensor housing cover 630 that receives the cleaning water preferably has hydrophilicity. For example, the inner surface of the concave portion 631 is covered with a hydrophilic resin.

  In this case, when discharge of the cleaning water from the turbidity detection nozzle 5x to the concave portion 631 is completed, the cleaning water is prevented from adhering to the inner surface of the concave portion 631 as a droplet. This prevents the dirt from adhering unevenly to the inner surface of the concave portion 631. As a result, every time the turbidity of the cleaning water is detected, it is possible to prevent the turbidity detection accuracy from being lowered by the droplets adhering to the concave portion 631.

(5) Characteristics of Detection Signal In the following description, the area corresponding to the left accommodating part 9a of the lower tableware basket 9 in the inside of the washing tank 2 in FIG. 1 is defined as the washing area A, and the right accommodating part 9b of the lower tableware basket 9 is used. The area corresponding to the left storage part 8b is the cleaning area B, the area corresponding to the right accommodating part 8b of the upper tableware basket 8 is the cleaning area C, and the area corresponding to the left accommodating part 8a of the upper tableware basket 8 is the cleaning area D (see FIG. 3). In addition, each period of the cleaning areas A, B, C, and D is called a cleaning area period, and a period in which the cleaning or rinsing of the object to be cleaned 10 in all the cleaning areas is called one cycle period. That is, one cycle period is composed of four cleaning region periods.

  In the cleaning process and the rinsing process, for example, the CPU 70a rotates the motor of the pump 11 in one direction and temporarily stops the motor of the pump 11 every 30 seconds. Accordingly, the cleaning water is sequentially supplied to the first, second, third, and fourth flow paths Ra, Rb, Rc, and Rd, and the cleaning areas A, B, C, and D are sequentially cleaned every 30 sec. Water is jetted. Therefore, in this example, the cleaning or rinsing of the object 10 to be cleaned in the cleaning areas A, B, C, and D is completed in 2 minutes.

  An example of the detection result of the turbidity of the cleaning water in the cleaning process will be described. FIG. 8 is a graph illustrating an example of a detection result of the turbidity detection unit 60 in a general case in the cleaning process. In the graph of FIG. 8, the vertical axis indicates the detected value (voltage value) of the turbidity of the wash water by the turbidity detection unit 60, and the horizontal axis indicates time. In this example, the detection value (voltage value) by the turbidity detection unit 60 decreases as the turbidity of the cleaning water increases.

  As shown in FIG. 8, the detected value of the turbidity of the washing water is maintained substantially constant from the time point t0 to the time point t1, from the time point t2 to the time point t3, and from the time point t4 onward, and from the time point t1 to the time point t2. In the period from the time point t3 to the time point t4, it greatly decreases and the fluctuation also increases.

  Here, in the present dishwasher 1, the washing water is supplied to the first, second, third, and fourth flow paths Ra, Rb, Rc, Rd in order as described above. Therefore, in the period when the cleaning water is not supplied to the third flow path Rc, there is no cleaning water in the concave portion 631 of FIG. Therefore, the detection value by the turbidity detection unit 60 is maintained almost constant.

  On the other hand, a detection result as shown in FIG. 9 may be obtained. This can occur, for example, when: In the process of heating the cleaning water, such as the cleaning process S2, the cleaning water vapor may fill the cleaning tank and water droplets may be attached to the turbidity detection 60. In such a situation, since the light from the light emitting element 64a is diffused by the water droplets, the turbidity detection unit 60 detects the turbidity higher than the actual turbidity (as a more dirty state). As a result, high turbidity is detected even during a period in which the wash water is not supplied to the third flow path Rc. In particular, when there is little contamination of the washing water, the turbidity between the period during which the washing water is supplied to the third flow path Rc and the period during which the washing water is not supplied are reversed, resulting in a detection result as shown in FIG. .

  In FIG. 9, the detected value of the turbidity of the washing water is maintained substantially constant from time t0 to time t1, from time t2 to time t3, and after time t4, and from time t1 to time t2 and time t3. From time to time t4, the fluctuation rises and increases greatly.

  In the above description, the detection result of the turbidity of the cleaning water in the cleaning process has been described. However, a similar detection result can be obtained in the rinsing process.

  From the characteristics of the detection signal shown in FIGS. 8 and 9, the wash water is supplied to the third flow path Rc during a period in which the detection signal greatly increases / decreases or a period in which the detection signal fluctuates (fluctuation width) is large. It can be determined that the period is over.

(6) Control Operation of Dishwasher Next, a control operation in washing of the dishwasher 1 according to the present embodiment will be described. FIG. 7 is a block diagram illustrating the configuration of the control system of the dishwasher 1, and FIGS. 10 to 13 are flowcharts illustrating the control operation of the control unit 70.

As shown in FIG. 7, the dishwasher 1 includes a control unit 70. The control unit 70 includes a CPU (Central Processing Unit) 70a, a memory 70b, and a timer 70c.

  The control unit 70 is connected to the turbidity detection unit 60, the temperature sensor 17, the water supply valve 31 a, the pump 11, the heater 14, and the drying mechanism 72.

  The control unit 70 sets the detection result (voltage value) of the turbidity of the cleaning water by the turbidity detection unit 60 and the detection result (voltage value) of the temperature of the cleaning water given from the temperature sensor 17 or the temperature in the cleaning tank 2. Based on this, the operations of the water supply valve 31a, the pump 11, the heater 14, and the drying mechanism 72 are controlled.

(6-a) Control operation example 1
The control operation example 1 shows an example in which the period during which the cleaning water is supplied to the third flow path Rc is determined based on the rise / fall of the detection signal.

  As shown in FIG. 10, first, the control unit 70 turns off the optical sensor and stops the operation of the turbidity detection unit (step S11). Next, by rotating the motor of the pump 11 in the reverse direction, the cleaning water remaining in the cleaning tank 2 is discharged, and then the opening and closing of the water supply valve 31a is controlled, so that the storage unit 12 of the cleaning tank 2 has a predetermined amount. The cleaning water is supplied (step S12).

  Subsequently, the control unit 70 starts cleaning the article to be cleaned 10 (step S13). Specifically, the control unit 70 rotates the motor of the pump 11 in the forward direction to circulate the cleaning water in the cleaning tank 2 and continuously injects the cleaning water to the object to be cleaned 10.

  Next, the control unit 70 turns on the optical sensor, operates the turbidity detection unit 60, and starts sampling the turbidity detection value (step S14).

  At this stage, since it is unclear which cleaning area is currently being cleaned, the cleaning area to which cleaning water is supplied is defined as the first, and 1 is assigned to variable i (step S15). The variable i is a variable that stores the number of the cleaning area where the cleaning area is currently being cleaned. Further, the cleaning region to which the cleaning water is supplied next is defined as the second cleaning region, and similarly, the third to fourth cleaning regions.

  Next, turbidity is sampled at regular intervals until the cleaning region period in the first cleaning region ends (step S16), and an average value D1 of the turbidity detection values sampled at the end of the cleaning region period ( Subscript 1 indicates the first cleaning area) (step S17). In the present embodiment, the cleaning region period is 30 sec. When the cleaning region period ends, the cleaning region moves to the second position, and i is incremented by 1 accordingly (step S18).

  Similarly, the turbidity average values D2 to D4 of the second to fourth cleaning regions are obtained, and the average value Av of D1 to D4 is calculated when one cycle period has elapsed (steps S19 to S20). Next, using the average value Av as a reference value, the absolute value of the difference between the average value Av and the turbidity average values D1 to D4 is determined, and ic = i is set for i where the absolute value is maximum (step S21). For example, ic = 3 when the difference is maximum when D = 3. In this case, it is determined that the third cleaning region is a cleaning region corresponding to the flow path Rc.

After specifying the cleaning region corresponding to the flow path Rc, the control unit 70 turns on the optical sensor and turns the turbidity detection unit 60 when i = ic, that is, when cleaning water is supplied to the flow path Rc. At the same time, storage of the minimum voltage value of the detection signal TS from the optical sensor 64 is started (steps S25 to S26). Specifically, the control unit 70 sets the initial value of the lowest cleaning voltage V1 to the maximum value of the detection signal TS and stores it in the memory 70b. Thereafter, the control unit 70 updates the lowest cleaning voltage V1 to a lower voltage value every time the voltage value of the detection signal TS output from the optical sensor 64 becomes lower than the lowest cleaning voltage V1 stored in the memory 70b.
On the other hand, the control unit 70 turns off the photosensor to stop the turbidity detection unit 60 when i ≠ ic, that is, when cleaning water is not supplied to the flow path Rc, and simultaneously detects the detection signal TS from the photosensor 64. The storage of the minimum voltage value is stopped (steps S27 to S28).

  Next, the control unit 70 determines whether or not the specified cleaning time has elapsed (step S23).

  If the specified cleaning time has not elapsed, the control unit 70 repeats steps S24 to S32.

  When the specified cleaning time has elapsed in step S23, the control unit 70 determines the minimum cleaning voltage V1 stored in the memory 70b at that time (step S33). Thereafter, the control unit 70 turns off the optical sensor 64 (step S34), stops the operation of the pump 11, and ends the cleaning of the article 10 to be cleaned (step S35).

(6-b) Control operation example 2
In the control operation example 2, an example in which the period during which the cleaning water is supplied to the third flow path Rc is determined based on the fluctuation width of the turbidity detection value. In the control operation example 2, only the determination of the period during which the cleaning water is supplied to the flow path Rc will be described with reference to FIG. 12 (corresponding to steps S14 to S21 in FIGS. 10 to 11).

  First, turbidity is sampled at regular intervals until the cleaning region period in the first cleaning region ends (step S43), and the maximum value D1_max among the turbidity detection values sampled at the end of the cleaning region period. Then, the minimum value D1_min (subscript 1 indicates the first cleaning region) is calculated (step S44). In the present embodiment, the cleaning region period is 30 sec. When the cleaning region period ends, the cleaning region moves to the second position, and i is incremented by 1 accordingly (step S45).

  Similarly, the maximum value and the minimum value D2_max to D4_max and D2_max to D4_min of the turbidity in the second to fourth cleaning areas are obtained, and the fluctuation width of the turbidity detection value in each cleaning area when one cycle period elapses. Wi = Di_max−Di_min is calculated (step S47). Next, ic = i is set for i that maximizes Wi (step S48). For example, ic = 2 when Wi is maximized. In this case, it is determined that the second cleaning region is a cleaning region corresponding to the flow path Rc.

(7) Effect (7-a) In this dishwasher 1, the operation time of the turbidity detection unit is minimized by detecting the period during which the washing water flows through the third flow path Rc. Turbidity can be detected. As a result, the shortening of the lifetime of the optical sensor is suppressed. In particular, in the dishwasher 1, the washing water is heated by the heater 14 around 50 degrees when the oil dissolves in the washing water in order to wash the oil adhering to the article 10 to be washed with the washing water. Therefore, if an electric current is passed through the optical sensor to detect the turbidity of such hot cleaning water, the lifetime of the optical sensor is shortened due to the influence of the hot cleaning water and the self-heating caused by the electric current. However, in this dishwasher, the optical sensor is operated only for a necessary period, so that the lifetime of the optical sensor can be extended.

  (7-b) Further, the wash water is supplied to the third flow path Rc based on the difference value between the turbidity of the wash water detected by the turbidity detection unit 60 and the reference value calculated based on the turbidity. By determining the flowing period, the accuracy of the determination can be increased. Thereby, the precision of the turbidity detection of washing water can also be raised, and the to-be-washed | cleaned object 10 can be wash | cleaned more efficiently.

  (7-c) In addition, the determination accuracy is improved by determining the period during which the wash water flows through the third flow path Rc based on the turbidity fluctuation width of the wash water detected by the turbidity detection unit 60. be able to. Thereby, the precision of the turbidity detection of washing water can also be raised, and the to-be-washed | cleaned object 10 can be wash | cleaned more efficiently.

(8) Modification (8-a) In the control operation example 1 and the control operation example 2, the third flow is based on the detection result of the turbidity of the washing water in one cycle period detected by the turbidity detection unit 60. Although the period during which the washing water flows in the path Rc is determined, when higher accuracy is required, the period may be determined based on the detection results of a plurality of cycles.

(8-b) In the control operation example 1 and the control operation example 2, after determining the period during which the cleaning water flows through the third flow path Rc, the turbidity detection unit 60 is operated in a part of another cleaning region. The flow path determination may be continued.
For example, after determining the period, the turbidity detection unit 60 is operated in the two cleaning regions of the third channel Rc and the first channel Ra, and the difference from the average value of turbidity in the two regions Alternatively, when there is no difference in the turbidity fluctuation width, the flow path determination is performed again, assuming that the period of the third flow path Rc is shifted for some reason.

  (8-c) In the dishwasher 1 described above, one turbidity detection unit 60 corresponding to the third flow path Rc is provided. Not only this but the some turbidity detection part 60 may be provided corresponding to 1st-4th flow path Ra-Rd.

  In this case, the plurality of turbidity detection units 60 can operate when cleaning water is supplied to the provided flow path.

  (8-d) In the dishwasher, the water diversion mechanism 15 sequentially supplies wash water to each of the first to fourth flow paths Ra to Rd, but first the first flow path Ra, Next, the flow path through which the water diversion mechanism 15 supplies the wash water may be arbitrarily changed, such as the second flow path Rb and then the third and fourth flow paths Rc and Rd.

(9) Correspondence between each constituent element of claim and each element of the embodiment Hereinafter, an example of correspondence between each constituent element of the claim and each element of the embodiment will be described. It is not limited to.

  In the above embodiment, the rotary cleaning nozzles 3, 4, 7 and the fixed cleaning nozzle 5 are examples of a plurality of cleaning nozzles, and the pump 11, the water diversion mechanism 15 and the first to fourth flow paths Ra to Rd are included. It is an example of a water supply part, and the detected value of the turbidity of the washing water by the turbidity detection part 60 is an example of information relating to the turbidity of the washing water.

  Further, the fluctuation period is an example of a period in which cleaning water is supplied to at least one cleaning nozzle, and the average value Av in FIG. 8 and the like is an example of a reference value.

  As each constituent element in the claims, various other elements having configurations or functions described in the claims can be used.

  The present invention can be effectively used for a dishwasher.

DESCRIPTION OF SYMBOLS 1 Dishwasher 2 Washing tank 3, 4, 7 Rotating washing nozzle 5 Fixed washing nozzle 5x Turbidity detection nozzle 10 Object to be washed 11 Pump 12 Storage part 14 Heater 15 Water distribution mechanism 60 Turbidity detection part 64 Optical sensor 64a Light emitting element 64b Light receiving element 70 Control unit 610 Lower cover 631 Concave portion 632 Bottom surface Av Average value Di Turbidity of cleaning water in each cleaning region Di_max Maximum value of cleaning water turbidity in each cleaning region Di_min Turbidity of cleaning water in each cleaning region Minimum value Wi The fluctuation range of turbidity of washing water in each washing region Ra to Rd First to fourth flow paths

Claims (4)

A dishwasher that sprays washing water to wash an object to be cleaned,
A storage tank for storing cleaning water, and a cleaning tank for storing an object to be cleaned;
A plurality of cleaning nozzles provided in the cleaning tank;
A water supply unit that sequentially supplies the cleaning water stored in the storage unit to the plurality of cleaning nozzles and injects the cleaning water from the cleaning nozzles onto the objects to be cleaned,
Cleaning provided in the cleaning tank at a position higher than the maximum water level of the cleaning water that can be stored in the storage unit, and having an optical sensor and supplied to at least one of the plurality of cleaning nozzles A turbidity detector that detects information about the turbidity of water;
Based on information on the turbidity of the washing water detected by the turbidity detection unit, the washing condition of the object to be washed is adjusted, and a period during which washing water is supplied to the at least one washing nozzle is determined. A dishwasher comprising: a control unit that controls a period during which the turbidity detection unit operates. The control unit operates the turbidity detection unit during a period when cleaning water is supplied to the at least one cleaning nozzle, and operates the turbidity detection unit during a period when cleaning water is not supplied to the at least one cleaning nozzle. The dishwasher according to claim 1, wherein the dishwasher is not allowed. The control unit is configured to perform the at least one based on a difference between turbidity of each cleaning water and a reference value calculated based on the turbidity in a plurality of periods in which cleaning water is supplied to the plurality of cleaning nozzles. The dishwasher according to claim 1, wherein a period during which the washing water is supplied to the two washing nozzles is determined. The controller is configured to supply cleaning water to the at least one cleaning nozzle based on a turbidity fluctuation width of the cleaning water detected by the turbidity detecting unit during a period in which the cleaning water is supplied to the plurality of cleaning nozzles. The dishwasher according to claim 1, wherein a period for supplying is determined.

Images