JP2006075192A - Dishwasher - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that the precision of determining of a detergent deteriorates due to deterioration of forming causing from stain of dishware in a dishwasher with the function of determining a kind of the detergent according to a detected result obtained by detecting a foaming amount using an optical sensor. <P>SOLUTION: The rotation of a pump motor is controlled such that water jetted from a jet hole 7 is weakly jetted to such an extent that it does not splash the dishwasher in accelerating foaming by driving the pump motor of a pump 12 for both washing and draining with washing water to a predetermined level stored in the bottom portion of a washing tub 2 in washing determining process before starting washing operation. Thus, the washing water is not mixed with the stain of the dishware, the longitudinal level of foamability of the detergent is precisely reflected on the foaming amount of the washing water in the washing tub 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a dishwasher that performs washing by spraying water onto tableware housed in a washing cabinet.

  In a domestic dishwasher, water is supplied from a water supply source to a washing cabinet containing dishes and stored at the bottom of the washing cabinet, and the water is sucked by a washing pump and pumped to a nozzle arm. The tableware is washed and rinsed by spraying water onto the tableware from a water injection hole provided in the nozzle arm. The water hitting the tableware and the inner wall of the washing cabinet returns to the bottom of the washing cabinet and circulates such that the leftovers etc. are removed by the filter and then sucked by the washing pump again.

  In such a dishwasher, if a general kitchen detergent that easily foams is used, abnormal foaming may occur during the cleaning operation, resulting in extremely poor cleaning performance, and a dry air intake or exhaust port. There is a risk of foam leakage from the Therefore, in a conventional dishwasher, an instruction to use a dishwasher-detergent (hereinafter referred to as a dedicated detergent) having a property of suppressing foaming is given in an instruction manual or the like. Most households that have a dishwasher have both a dedicated detergent and a kitchen detergent, so it's natural that you mistakenly use the kitchen detergent when washing in the dishwasher. Can happen. Therefore, there has been known a dishwasher that detects the occurrence of abnormal foaming due to an accidental use of kitchen detergent and stops the operation and informs the user (user) of that fact. (See, for example, Patent Document 1).

  However, it is necessary to use different detergents, which is troublesome, and the amount of the kitchen detergent with much circulation is less expensive, or when the detergent is used incorrectly, time, detergent, water and electricity are wasted. As a result, users have been eagerly demanding a dishwasher that can use kitchen detergent. In response to these demands, the present applicant has proposed a new dishwasher provided with an operation course using a kitchen detergent in Japanese Patent Application No. 2003-138907. In addition to allowing the user to manually select a dedicated detergent course and a kitchen detergent course, the type of detergent that is input is automatically determined, and an operation course corresponding to the type of detergent is automatically selected. We have also proposed a dishwasher with a configuration that can be selected and executed.

  Such an automatic detergent determination function basically determines whether a detergent for kitchen or a dedicated detergent has been introduced by determining the degree of foaming of detergent water when the cleaning pump is operated. . In other words, kitchen detergent uses the fact that it has higher foaming properties than dedicated detergent, and kitchen detergent is used when a predetermined amount of foaming occurs in the washing cabinet within a predetermined time after starting the operation of the cleaning pump. The driving course is selected according to the determination result.

  However, the foaming condition of the detergent water is affected not only by the type of detergent but also by the degree of contamination of the dishes. Therefore, especially if there is a lot of oil stains in the dishes stored in the washing cabinet, even if kitchen detergent is used, foaming is not good, and it is misjudged that it is the use of a dedicated detergent. There was a problem that there was a risk of it.

  In addition, in a dishwasher equipped with an automatic detergent determination function, it is necessary to determine the type of detergent before starting a substantial washing operation. There is a problem that the operation time is prolonged.

  In addition, these dishwashers are designed to adjust the detergent concentration to prevent abnormal foaming when a kitchen detergent is used or when an excessive amount of dedicated detergent is introduced. The detergent water may be diluted by discharging a part of the detergent water stored in the machine to the outside of the machine and then supplying additional water into the washing cabinet. If the amount of drainage at this time is large, the amount of wasteful use of water is increased, and if the amount of drainage is large, the amount of additional water supply increases and the amount of water used increases accordingly. Therefore, in order to reduce the amount of water used during operation, that is, to save water, it is necessary to suppress this amount of drainage and additional water supply as much as possible.

JP 2002-336175 A

  The present invention has been made in view of such problems, and a first object of the present invention is to influence the degree of contamination of dishes in a dishwasher having an automatic determination function between kitchen detergents and dedicated detergents. It is an object of the present invention to provide a dishwasher that can be reduced and improve the accuracy of detergent determination. A second object of the present invention is to provide a dishwasher that can shorten the time required for detergent determination before washing operation as much as possible. Further, the third object of the present invention is to reduce the amount of detergent water in the washing cabinet and the amount of additional water supply for adjusting the detergent concentration and suppressing abnormal foaming as much as possible. It is providing the dishwasher which can suppress the usage-amount.

The first invention made to achieve the first object described above is to store water at the bottom of a washing cabinet in which tableware is housed and suck the stored water by a washing pump toward the tableware. In dishwashers that wash dishes by spraying,
Foam detection means for detecting the degree of foaming by the detergent water stored in the washing cabinet,
Operation control means for controlling the operation of the washing pump at the initial stage of the washing operation so that the jet of water toward the dishes becomes weaker than in the subsequent washing operation;
Detergent determination means for detecting the degree of foaming under a situation where water injection by the operation control means is weak, by the foam detection means, and determining the type of detergent according to the detection result;
It is characterized by having.

Further, the second invention made to achieve the above second and third objects is to store water at the bottom of a washing cabinet in which tableware is housed, and suction the stored water by a washing pump. In dishwashers that wash dishes by spraying on
A water level detection means for detecting that the water level of the stored water in the washing cabinet is a predetermined water level lower than the final washing water level;
Water supply means for supplying water into the washing cabinet up to a predetermined water level detected by the water level detection means;
A foam amount determining means for operating the cleaning pump in a state where the detergent water at the predetermined water level is stored in the bottom of the cleaning cabinet, and determining the degree of foaming generated at that time;
It is characterized by having.

  In the dishwasher according to the first aspect of the present invention, the type of detergent (whether it is a kitchen detergent or a dedicated detergent) that is activated based on the degree of foaming at the time when the washing pump is operated before the substantial washing operation In this case, the operation control means controls the operation of the washing pump so that the water injection becomes weaker than at least during the subsequent washing operation. At this time, since the jet pressure of water is weak, little or not much detergent water is not applied to the dishes stored in the washing cabinet. For this reason, the detergent water is not so dirty due to the dirt adhering to the dishes, and the foaming of the detergent water is not easily affected by the degree of the dirt. Accordingly, the degree of foaming of the detergent water accurately reflects the type of detergent used, and the detergent determination unit can accurately determine the type of detergent based on the detection result of the foam detection unit.

  After the detergent type is determined in this way, an operation sequence corresponding to the detergent type (in other words, depending on the degree of foaming) is selected and executed in order to suppress the generation of abnormal bubbles in the washing cabinet. It is good to do. For example, in the case of a highly foaming detergent (kitchen detergent), it is preferable to reduce the concentration of the detergent by partially discharging the stored detergent water or appropriately supplying additional water. In addition, when the foaming property of the detergent is high, the on time when the cleaning pump is intermittently driven may be made relatively shorter than when the detergent is low so as to suppress the generation of bubbles.

  According to the dishwasher according to the first aspect of the present invention, even when the dishes to be cleaned are severely soiled, the detergent used is a kitchen detergent or a dedicated detergent with almost no influence. Can be determined with high accuracy. Therefore, in dishwashers that can use kitchen detergent, it is possible to automatically determine the type of detergent with high accuracy, and the user does not need to input and set the operation course according to the detergent used. In the unlikely event that a detergent of a type different from that intended by the user is used, the operation can be performed without any problems. Therefore, it is very convenient to use, and the cost can be reduced by using an inexpensive kitchen detergent.

  As one embodiment of the dishwasher according to the first aspect of the invention, at the time of detergent type determination, the rotational speed of the motor that is the drive source of the washing pump is set higher than that during the washing operation and the driving time is set shorter than that during the washing operation. However, the foaming can be generated in the cleaning pump mainly by the stirring action of the impeller of the cleaning pump.

  In this configuration, the rotational speed at the time of driving the motor is set higher than that at the time of washing operation, but the drive time is short, so even if the impeller is rotated by the motor and water is discharged from the washing pump chamber vigorously, the flow is Instead, when the water reaches the injection hole, the water is killed and only flows out from the injection hole. Therefore, the detergent water hardly hangs on the dishes. In addition, since the detergent water is vigorously stirred in the cleaning pump chamber when the impeller is rotated at a high speed, if the detergent has a high foaming property, bubbles are generated in the cleaning pump chamber and the detergent water flows out from the injection holes. A lot of bubbles are mixed. Accordingly, even if the momentum of the detergent water discharged from the injection hole is weak, it is possible to obtain a foaming amount corresponding to the type of detergent, and it is possible to determine the type of detergent with high accuracy based on the degree of foaming.

  Further, as another embodiment of the dishwasher according to the first invention, at the time of detergent type determination, the rotational speed of the motor that is a driving source of the washing pump is set lower than that during washing operation, and the water sprayed into the washing cabinet is It is good also as a structure which made it difficult to reach to tableware because of its weak momentum.

  In this configuration, since the rotation speed at the time of driving the motor is set lower than that at the time of washing operation, even if the driving time continues for a long time, the momentum of water discharged from the injection hole is weak, and the range close to the injection hole Only water can reach. Therefore, the detergent water does not hang over the tableware, and the stain of the detergent water is suppressed. In the case of this configuration, even if the foaming property of the detergent is high, the amount of foam generated in the washing pump chamber is not so large, but the detergent water discharged weakly from the injection hole is on the detergent water in which the detergent water is stored. A large amount of foam is generated when falling. Therefore, even in this case, the amount of foaming corresponding to the type of detergent can be obtained, and the type of detergent can be determined with high accuracy based on the degree of foaming.

  In the dishwasher according to the second aspect of the present invention, the water supply means supplies water into the washing cabinet up to a predetermined water level detected by the water level detection means when water is supplied in the washing operation. Since the water level at this time is set lower than the standard wash water level that is finally set, the amount of water supplied is small, and the concentration of the detergent water in which the detergent put into the washing cabinet has dissolved is usually It is thicker than the detergent concentration during washing operation. Therefore, when the detergent is highly foaming, a large amount of foam is generated just by operating the cleaning pump for a short time. Therefore, the time until the foam amount determination means determines the foam amount is short, and the foam amount can be determined quickly after the start of operation, and the process can proceed to the next processing according to the result. That is, in the dishwasher according to the second aspect of the present invention, it is possible to avoid prolonging the required operation time even if the process for automatically determining the foaming amount is performed.

  As described above, the amount of foaming depends on the type of detergent and also on the degree of soiling of the dishes stored in the washing cabinet. Therefore, it is possible to identify the type of detergent based on the determination result of the foaming amount, and to determine the degree of tableware contamination. Then, by selecting an appropriate operation sequence according to such a determination result, it is possible to prevent an abnormal amount of bubbles from being generated in the washing cabinet during the washing operation.

  Specifically, in the dishwasher according to the second aspect of the present invention, the operation control means for determining the amount of stored water drainage and / or the amount of additional water in accordance with the determination result by the foaming amount determination means, can do.

  In this configuration, after the operation control means determines the foaming amount at a water level lower than the final washing water level, a highly foaming detergent such as a kitchen detergent is used and the foaming amount is high. When the amount is large, the amount of additional water supply is increased and the detergent concentration is relatively lowered than when the amount of foaming is small. Alternatively, after a part of the detergent water is discharged to reduce the absolute amount of detergent, additional water supply is performed to adjust the detergent concentration. In the first place, since the amount of foaming is determined at a low water level, the detergent concentration is high as described above, and the amount of detergent water can be reduced when it is desired to reduce the absolute amount of detergent by a predetermined amount. Therefore, even when part of the detergent water is discharged and additional water supply is performed, the amount of discharge is small, and the additional water supply amount can be suppressed. Therefore, according to the said structure, the amount of drainage and additional water supply can be decreased and the usage-amount of water can be suppressed.

  In the dishwasher according to the second invention, the predetermined water level for determining the amount of foaming is preferably as low as possible in terms of increasing the detergent concentration. However, if the water level is too low, air chewing will occur during suction of the washing pump and appropriate water Suction cannot be performed. Since the ease of occurrence of air biting also depends on the control method of the pump motor, it is preferable to set a water level as low as possible within a range where air biting does not occur in consideration of such conditions.

  A dishwasher according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a dishwasher according to the present embodiment, FIG. 2 is a side longitudinal sectional view of the dishwasher according to the present embodiment, and FIG. 3 is a diagram showing a structure of a drying air passage disposed inside the right side of the dishwasher. It is a side schematic perspective view of a part.

  A cleaning cabinet 2 also serving as a drying chamber is disposed inside the housing 1, and an upper door 3 and a lower door 4 that are pivotally supported at the upper end and the lower end of the cleaning cabinet 2 are arranged in the vertical direction. It is attached to open the door. A handle 17 is provided at the center of the upper end of the lower door 4. When the user grasps the handle 17 and pulls the lower door 4 forward to open it, the upper door 3 opens in conjunction with this. It has become. An operation panel 18 is disposed below the lower door 4. In the operation panel 18, a power switch, a start key, a course selection key, and the like are arranged as the operation unit 18a, and a course display unit that displays the driving course selected by the course selection key as the display unit 18b, A condition display section for displaying the drying time, presence / absence of hot water supply setting, and the like are arranged.

  With the upper door 3 and the lower door 4 opened, the tableware bowl 5 is put in and out of the washing cabinet 2. A part of the tableware bowl 5 (the rear side in this example) has a lower side that accommodates a small-diameter dish or a rice bowl, and a cup (such as a cup or a cup of teacup) G is placed on the upper side. The cup mounting shelf 5a is rotatably provided. A rotatable nozzle arm 6 having a plurality of water injection holes 7 formed on the upper surface is provided at the bottom of the cleaning cabinet 2. In this dishwasher, since the width of the washing cabinet 2 is larger than the depth, water does not reach the both sides of the washing cabinet 2 with only one nozzle arm. Therefore, another nozzle arm (not shown) is provided in a position where it does not interfere with the nozzle arm 6 shown during rotation.

  A water storage tank 8 is formed in the bottom of the washing cabinet 2 so as to be recessed one step lower, and on the upper surface thereof, a leftover filter 11 for collecting the leftovers that have flowed down from the dishes is detachably provided. . A water supply port (not shown) having a water supply valve (not shown) is disposed on the side of the cleaning cabinet 2, and when this water supply valve is opened, water supplied from an external water tap or the like passes through the water supply port and the cleaning cabinet 2. It is poured in and stored in the bottom of the washing cabinet 2 including the water storage tank 8.

  The water level stored in the washing cabinet 2 is detected by a water level sensor 19 as water level detection means in the present invention. The water level sensor 19 includes an air trap 191 that communicates with the water storage tank 8, a pressure sensor 192 that is disposed at the lower back of the cleaning cabinet 2, and an air hose 193 that connects the air trap 191 and the pressure sensor 192. When the water level in the washing chamber 2 changes, the air pressure in the air trap 191 changes accordingly. By detecting this with the pressure sensor 192, it is possible to detect the water level for easy washing and the abnormal water level when excessive water is stored. In addition, a loop-shaped heater 16 is provided at the bottom of the cleaning chamber 2 to heat the water stored in the cleaning chamber 2 and to heat the air in the cleaning chamber 2 during drying.

  A washing and draining pump 12 as a washing pump in the present invention is disposed below the bottom wall surface of the washing cabinet 2. Although not shown, the cleaning and drainage pump 12 has a cleaning pump chamber and a drainage pump chamber partitioned by a partition wall. The cleaning pump chamber 12 and the drainage pump chamber have a cleaning pump mounted coaxially with the pump motor. An impeller and a drainage impeller are provided. The suction port 13 of the cleaning pump chamber is connected to a circulation port 9 provided in the rear wall of the water storage tank 8, and the discharge port 14 is connected to the nozzle arm 6 and the water via a water passage 15 extending in the lateral direction. It communicates with the water channel of another nozzle arm (not shown). On the other hand, although not shown, the suction port of the drainage pump chamber is connected to the drainage port 10 provided on the side wall of the water storage tank 8, and the discharge port of the drainage pump chamber communicates with the outside through the drainage hose 21. Yes.

  Thus, when the pump motor of the cleaning / drainage pump 12 is driven to rotate in the normal direction while water is stored in the bottom of the cleaning cabinet 2, the cleaning / drainage pump 12 functions as a cleaning pump. That is, the water sucked from the water storage tank 8 through the circulation port 9 is pumped to the nozzle arm 6 through the water channel 15 by the action of the rotating cleaning impeller. Then, water is ejected from a water injection hole 7 provided on the upper surface of the nozzle arm 6, and the nozzle arm 6 rotates in a predetermined direction around a substantially vertical axis by the water force. The water sprayed from the water spray hole 7 hits the tableware stored in the washing cabinet 2, and removes dirt adhering to the tableware or allows detergent water to flow. On the other hand, when the pump motor is driven to rotate in the reverse direction, the washing and draining pump 12 functions as a draining pump. That is, the water sucked from the water storage tank 8 through the drain port 10 is discharged to the outside through the drain hose 21 by the action of the rotating drain impeller.

  As shown in FIG. 3, a blower 23 is disposed beside the cleaning / drainage pump 12 at the bottom of the cleaning cabinet 2. Although not shown, the blower 23 includes a blower fan housed in a fan casing and a fan motor that rotationally drives the blower fan. From the fan casing, the drying air passage 24 extends obliquely rearward and then extends upward, is bent in an inverted U shape (bent portion 23a), extends downward, and then extends obliquely forward. A lower end portion of the drying air passage 24 communicates with a blower opening 25 opened in the cleaning cabinet 2. When the blower fan is rotated, the outside air sucked from the intake port 22 formed on the bottom surface of the housing 1 is introduced from the blower port 25 into the cleaning cabinet 2 through the dry air passage 24. On the other hand, the air containing moisture in the cleaning cabinet 2 is discharged from the front side exhaust port 20 to the outside of the machine.

  Near the outlet of the drying air passage 24, an optical sensor 30 having a plurality of functions to be described later is attached. FIG. 4 is an enlarged view around the installation portion of the optical sensor 30, and FIG. 5 is a schematic diagram for explaining the operation of the optical sensor. The optical sensor 30 includes a light emitting unit 31 and a light receiving unit 32 that are attached at positions facing each other in the vertical direction. For example, an infrared LED is used as the light emitting unit 31, and a photodiode (PD) is used as the light receiving unit 32. These are all housed in a transparent mounting case, and are provided with a sealing member for ensuring airtightness and water tightness. Are attached to members constituting the drying air passage 24.

  The light emitting unit 31 emits light substantially vertically downward, and the light receiving unit 32 is directly below the light emitting unit 31 and receives light from the light emitting unit 31. In the dishwasher of the present embodiment, the mounting position of the light receiving unit 32 is determined so that the upper end of the lens coincides with the predetermined water level line L1. The position of the water level line L1 is lower than the finally set standard washing water level and higher than the casing of the washing and draining pump 12. As will be described later, the pump motor 12a is turned on / off for 0.1 second. This is the lowest position in the range in which the cleaning and drainage pump 12 can suck the stored water in the cleaning cabinet 2 without generating air jamming under the condition of intermittent driving with a driving pattern of 0.5 second off. The amount of foaming is detected as will be described later in a state where water is stored up to the water level line L1, and the detergent type determination process is executed based thereon.

  When a large amount of bubbles is generated on the water surface by the operation of the pump motor 12a in a state where water is stored up to the water level line L1, a state as shown in FIG. 5A is obtained. In this case, the light emitted from the light emitting unit 31 reaches the light receiving unit 32 after being scattered and absorbed when passing through the bubbles. Therefore, the amount of received light decreases as the amount of bubbles increases in the range below the mounting position of the light emitting unit 31, and the amount of foam can be estimated from the degree of decrease in the amount of received light. That is, the optical sensor 30 functions as a foam detection means in the present invention. Since the water level line L1 is originally set in the vicinity of the upper end of the light receiving unit 32, it can be considered that almost all of the decrease in the amount of received light at the light receiving unit 32 is the influence of bubbles. Therefore, the amount of foaming can be detected with high accuracy.

  Further, as shown in FIG. 5B, in the state where water is stored up to the position of the water level line L2 where the light emitting unit 31 is completely submerged, the light emitted from the light emitting unit 31 reaches the light receiving unit 32. All the light paths in the water become underwater. Therefore, the more dirty the water is, the more light is scattered or absorbed along the way. Therefore, in this case, the degree of water contamination can be estimated from the degree of decrease in the amount of received light. As described above, the optical sensor 30 can perform either a bubble detection or a dirt detection operation according to the water level.

  FIG. 6 is an electric system configuration diagram of a main part of the dishwasher of the present embodiment. The control unit 40 that functions as an operation control unit, a detergent determination unit, and a foam amount determination unit in the present invention is configured around a microcomputer, controls the rotation of the pump motor 12a via an inverter drive unit 41, and loads The operation of the heater 16 and the fan motor 46 as well as the water supply valve 45 which is the water supply means in the present invention is controlled via the drive unit 42. The control unit 40 is also connected with an operation unit 18a, a display unit 18b, a door switch 42, a temperature sensor 43, a water level sensor 19, an optical sensor 30, and the like. The control unit 40 includes a ROM in which a control program is stored, and the CPU executes various control operations as described later when the CPU executes the control program. In addition, since the rotation of the pump motor 12a is controlled by the inverter drive unit 41, not only simple on / off, but also fine control of the rotation speed is possible.

  FIG. 7 is a schematic flowchart showing a standard process flow in the dishwasher. The user stores the dishes in the tableware bowl 5 and opens the doors 3 and 4 to store the tableware bowl 5 in the washing cabinet 2. Then, after an appropriate amount of detergent (kitchen detergent or special detergent) is put into the washing cabinet 2 and the doors 3 and 4 are closed, the course selection is performed with the course selection key as necessary at the operation unit 18a. Press the key. The control unit 40 starts operation upon receiving this operation.

  Immediately after the start of operation, the water supply valve 45 is first opened to determine whether the detergent used is a kitchen detergent or a dedicated detergent in a state where a predetermined amount of water is stored in the washing cabinet 2. Processing is executed (step S1). Based on the detergent judgment result, additional water is supplied to adjust the detergent concentration, and when using kitchen detergent, the degree of dirt is also detected, and the control details during the washing process are determined according to the degree of dirt and the type of detergent. decide. And the washing process using detergent water is performed by driving the pump motor 12a according to the determined control content (step S2).

  Then, in order to wash away the detergent water adhering to tableware, the water in the washing | cleaning store | warehouse | chamber 2 is replaced and a rinse process is performed 3 times (step S3-S5). And in order to raise the drying efficiency at the time of the next drying by performing disinfection and warming dishes, the stored water is heated to a high temperature with the heater 16, and the heating rinse process using the high temperature water is performed ( Step S6). When the heating rinsing is completed, water is completely discharged from the cleaning chamber 2, the heater 16 is heated, and the fan motor 46 is driven to send air into the cleaning chamber 2 to execute a drying process (step S7). When the drying time is over, the operation is terminated.

  Next, details of the detergent determination process, which is a feature of the dishwasher of the present embodiment, will be described with reference to the flowcharts of FIGS.

  After the operation is started, it is determined whether or not the water supply is finished (step S10). In a normal usage method, since the water supply is not completed after the operation is started, the process proceeds to step S11, the water supply valve 45 is opened, and the water supply into the cleaning cabinet 2 is started. And it is determined by the detection signal of the water level sensor 19 whether or not the water up to the water level line L1 which is the lowest water level has been stored (step S11), and if it has not reached the water level line L1, the water supply is continued (step S14). The process returns to step S12. When the water level of the stored water reaches the water level line L1, the control unit 40 closes the water supply valve 45 to temporarily end the water supply (step S13).

  Next, it is determined whether or not the detergent detection has been completed (step S15). In the normal use method, the detergent detection has not been completed at this point, so the process proceeds to step S16, and the inverter drive unit 41 drives the pump motor 12a as a cleaning pump motor for 0.1 second on / 0.5 second off. Drive intermittently with patterns. At this time, the rotation speed at the time of turning on is higher than the rotation speed at the time of normal washing operation. Specifically, the rotation speed during the washing operation is 3600 rpm, whereas the rotation speed when the motor is turned on in step S16 is preferably 4200 rpm. The rotation of the pump motor 12a causes the cleaning impeller to rotate at a high speed in the cleaning pump chamber of the cleaning / drainage pump 12 and vigorously agitate the water sucked from the circulation port 9 and the detergent. Therefore, when the foaming property of the detergent is high, a large amount of foam is generated in the cleaning pump chamber, and a large amount of foam is sent to the nozzle arm 6 through the water passage 15. However, the on-time of the pump motor 12a is very short, and when the motor is off, the pumping of water to the nozzle arm 6 stops, so that the water is not ejected vigorously from the injection hole 7, and the detergent water containing bubbles overflows. So as to flow out of the injection hole 7. When the detergent is highly foamable, the amount of foam flowing out from the injection hole 7 is large, and when the foamability is low, the amount of foam is small or almost no foam.

  Thus, after the pump motor 12a is intermittently driven for a predetermined time (for example, about 20 seconds), the control unit 40 determines the amount of light received by the light sensor 32, specifically the amount of light received by the light receiving unit 32, in the cleaning chamber 2. Detects the amount of foam generated in. As described above, since the momentum of the detergent water discharged from the injection hole 7 when the pump motor 12a is driven is weak, the water does not squirt so as to be applied to the tableware stored in the tableware bowl 5. Therefore, the dirt adhering to the dishes is hardly removed, and there is almost no risk of contamination of the detergent water by the dirt. In general, if the detergent water becomes dirty (especially if it is oily), the foaming becomes worse. However, as described above, the detergent water hardly gets dirty, so the level of foaming accurately reflects the level of foaming of the detergent. Will be.

  Further, when the pump motor 12a is operated in step S16, since the water up to the lowest water level in the range where the pump air is not generated is stored at the bottom of the washing cabinet 2, the detergent water at this time is stored. The concentration is considerably higher than the concentration of detergent water at a water level suitable for normal washing operation. Therefore, when the detergent is a kitchen detergent, a large amount of foam is generated by the operation of the pump motor 12a for a relatively short time. Therefore, the operation time of the pump motor 12a in step S16 can be short, and the type of detergent can be determined. The time required can be shortened.

  After the operation of the pump motor 12a as described above, the amount of foaming is classified into one of three, large, medium, and small, by the determination processing in steps S17 and S18. If it is determined that the amount of foaming is large, it is determined that the detergent used is a kitchen detergent (step S19), and adjustment is made to reduce the detergent concentration by performing additional water supply of a predetermined amount V1 ( Step S20). Even when it is determined that the foaming amount is medium, it is determined that the detergent used is a kitchen detergent (step S21), and the predetermined concentration V2 is added to adjust the detergent concentration to be thin. (Step S22). In this case, since the amount of foaming is smaller than in the case of step S20, the amount V2 of additional water supply is set to be smaller than the amount V1. On the other hand, when it is determined that the amount of foaming is small, it is determined that the used detergent is a dedicated detergent (step S23), and additional water is supplied up to a specified washing water level (step S24).

  Next, it is determined whether or not the detergent determination result is a kitchen detergent (step S25). If it is a kitchen detergent, the process proceeds to step S26, where the inverter drive unit 41 causes the pump motor 12a to rotate intermittently with a drive pattern of 0.2 second on / 1.0 second off as a cleaning pump motor. At this time, the rotational speed when the motor is on is the same as the rotational speed during normal washing operation. Accordingly, at this time, the detergent water is ejected vigorously from the injection hole 7 and is applied to the dishes, and the dirt adhering to the dishes is removed and mixed with the detergent water. As described above, since the foaming is generally worsened when the detergent water becomes dirty, it is possible to estimate the degree of tableware contamination by determining the amount of foaming under these circumstances.

  That is, after operating the pump motor 12a for a predetermined time, the amount of foaming is classified into one of three, that is, a large amount, a medium amount, and a small amount, by the determination processing in steps S27 and S28. If it is determined that the amount of foaming is large, it is determined that the dirt is mild (step S29). At this time, since there is a high possibility that the foaming amount becomes excessive, the detergent concentration is further lowered so as to suppress the foaming amount by performing additional water supply of a predetermined amount V3 (step S30). If it is determined that the amount of foaming is medium, it is determined that the amount of foaming is medium (step S31). At this time, since the foaming amount may become excessive, the concentration of the detergent is decreased by performing additional water supply of a predetermined amount V4 in order to suppress the foaming amount (step S32). In this case, since the amount of foaming is smaller than in the case of step S20, the amount of additional water supply V4 is set to be smaller than the amount V3. On the other hand, when it is determined that the amount of foaming is small, it is determined that the dirt is severe and severe (step S33). In this case, since foaming is suppressed by dirt, it is not necessary to lower the detergent concentration and no additional water supply is performed.

  Next, it is determined whether or not to continue the cleaning operation (step S34). Usually, since the cleaning operation is subsequently executed, the process proceeds to step S35, and it is determined whether or not the result of the processing is either severe dirt or the use of a dedicated detergent (step S35). If so, the cleaning control pattern A is selected (step S37). If it is determined that it is neither heavy dirt nor the use of a special detergent, then it is determined whether or not the dirt is moderate (step S36). If the dirt is moderate, the cleaning control pattern B is determined. Is selected (step S38). If the stain is not moderate, that is, if it is determined that the stain is mild, the cleaning control pattern C is selected (step S39).

The cleaning control patterns A, B, and C are, for example, the following intermittent drive patterns of the pump motor 12a.
Cleaning control pattern A: 4 minutes on / 3 seconds off Cleaning control pattern B: 1 minute on / 3 seconds off Cleaning control pattern C: 10 seconds on / 1 second off In other words, bubbles are generated depending on the type of detergent and the degree of contamination. The easier the situation is, the shorter the ON time of the pump motor 12a is, and the shorter the time for spraying the detergent water from the spray hole 7 is. Thereby, it is possible to exhibit good cleaning performance in accordance with the type of detergent and the degree of dirt while effectively suppressing abnormal foaming in the cleaning cabinet 2. Of course, the drive pattern is an example, and can be changed as appropriate.

  In the above embodiment, in step S16, the ON time of the pump motor 12a is made shorter than that in the washing operation, while the rotation speed is increased. However, the detergent water discharged from the injection hole 7 is used as much as possible in the dishes. It is only necessary to stir the detergent water appropriately so as not to be hung so as to cause foaming. Therefore, the rotational speed may be lowered as compared with the normal washing operation while setting the ON time of the pump motor 12a to be as long as about 5 seconds. At this time, since the rotational speed of the cleaning impeller is relatively low, even if the foaming property of the detergent is high, the foam generated in the cleaning pump chamber is not so much, but the detergent water jetted weakly from the injection hole 7 Many bubbles are generated when falling into the stored detergent water. Thereby, the type of detergent can be determined with high accuracy from the degree of generation of bubbles.

  Moreover, in the said Example, after determining the kind of detergent in step S17-S24, additional water supply is performed according to the determination result, and detergent density | concentration is made thin, However, Depending on the case, a part of stored detergent water It is also possible to perform additional water supply after discharging the water and reducing the amount of detergent itself. Even in such a case, it is sufficient to discharge a relatively small amount of detergent water in a state where the detergent concentration is high, so that the amount of drainage is small and waste of water can be suppressed.

  In the dishwasher of the above-described embodiment, the optical sensor 30 has a function of detecting bubbles and a stain of washing water. However, by changing the configuration of the optical sensor 30, a function of detecting the water level can be provided. A dishwasher according to another embodiment having a different configuration of the optical sensor 30 will be described. FIG. 10 is an enlarged view of the periphery of the installation portion of the optical sensor in the dishwasher of this embodiment, and FIG. 11 is a schematic diagram showing the detection operation by the optical sensor. Constituent elements that are the same as or correspond to those in the above embodiment are given the same reference numerals, and descriptions thereof are omitted.

  As shown in FIG. 10, an optical sensor 50 corresponding to the optical sensor 30 in the above-described embodiment includes a single light emitting unit 51 attached to the front and rear opposed positions across the drying air path 24, and the first and second. And two light receiving portions 52 and 53. The positional relationship between the light emitting unit 51 and the first light receiving unit 52 is such that the light emitting unit 51 is at a higher position than the first light receiving unit 52 and the two are opposed to each other. On the other hand, the second light receiving unit 53 is positioned higher than the first light receiving unit 52, and the light emitted from the light emitting unit 51 is between the second light receiving unit 53 and the first light receiving unit 52, and the first light receiving unit. It is attached with a position and an inclination that can receive light reflected by a horizontal reflecting surface set at substantially the same height as the lens surface of the portion 52.

  As shown in FIG. 11A, when water is stored up to the position of the water level line L1, the light emitted from the light emitting unit 51 and reflected by the water surface is just incident on the second light receiving unit 53. That is, since the second light receiving unit 53 can obtain a detection signal corresponding to the light emitted from the light emitting unit 51, the water level supplied into the cleaning cabinet 2 is determined based on the detection signal from the second light receiving unit 53. It can be detected that the vicinity of the line L1 has been reached. The height of the water level line L1 is lower than the standard washing water level, as in the above-described embodiment, and air biting does not occur when the water stored in the washing cabinet 2 is sucked by the washing and draining pump 12. The above-described detergent type determination process is executed in a state where water is stored up to the water level line L1.

  When a large amount of bubbles is generated on the water surface by the operation of the pump motor 12a in a state where water is stored up to the water level line L1 as shown in FIG. 11A, a state as shown in FIG. 11B is obtained. In this case, the light emitted from the light emitting unit 51 reaches the first light receiving unit 52 after being scattered and absorbed when passing through the bubbles. Therefore, the amount of received light decreases as the amount of bubbles increases in the range below the mounting position of the light emitting unit 51, and the amount of foam can be estimated from the degree of decrease in the amount of received light. Since the water level line L1 is originally set in the vicinity of the upper end of the first light receiving unit 52, it can be considered that almost all the decrease in the amount of light received by the first light receiving unit 52 is the influence of bubbles. Therefore, it is convenient for accurately detecting the amount of foaming.

  Further, as shown in FIG. 11C, in a state where water is stored up to a position where the light emitting unit 51 is completely submerged, all the optical paths until the light emitted from the light emitting unit 51 reaches the first light receiving unit 52 are stored. Becomes underwater. Therefore, the more dirty the water is, the more light is scattered or absorbed along the way. Therefore, in this case, the degree of water contamination can be estimated from the degree of decrease in the amount of received light. Thus, it can be seen that the optical sensor 50 can perform three types of detection operations of water level detection, bubble detection, and dirt detection according to the selection of the light receiving parts 52 and 53 and the water level. Therefore, when such an optical sensor 50 is employed, there is no need to separately provide a pressure detection type or float type water level sensor, which simplifies the configuration of the apparatus and contributes to cost reduction.

  In each of the above-described embodiments, the optical sensors 30 and 50 are installed in the dry air passage 24 that communicates with the inside of the cleaning cabinet 2. However, when water is stored in the cleaning cabinet 2, the same water level change is performed. As long as it is positioned so that bubbles generated in the cleaning cabinet 2 are stacked on the water surface in the same manner as in the cleaning cabinet 2, the inside of the cleaning cabinet 2 itself and other parts other than the drying air passage 24, etc. Of course, the optical sensors 30 and 50 may be provided. Moreover, when providing the optical sensors 30 and 50 in the washing | cleaning store | warehouse | chamber 2, in order to prevent a misdetection, the water sprayed from the nozzle arm 6 is directly applied to the optical sensors 30 and 50, or it accompanies driving | operation. Since it is preferable to reduce the influence of a large ripple on the water surface as much as possible, it is preferable to protect the optical sensors 30 and 50 by using a simple partition plate or a shielding member.

  Furthermore, any of the above-described embodiments is merely an example of the present invention, and it is apparent that the present invention is encompassed by appropriate modifications, additions, or additions within the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The external appearance front view of the dishwasher which is one Example of this invention. The side longitudinal cross-sectional view of the dishwasher of a present Example. The side schematic perspective view of the principal part which shows the structure of the dry air path arrange | positioned inside the right side surface of the dishwasher of a present Example. The enlarged view of the circumference | surroundings of the installation part of the optical sensor in FIG. The schematic diagram which shows the detection operation of the optical sensor in the dishwasher of a present Example. The electric system block diagram of the principal part of the dishwasher of a present Example. The flowchart which shows the flow of the standard process in the dishwasher of a present Example. The detailed flowchart of the detergent determination process in the dishwasher of a present Example. The detailed flowchart of the detergent determination process in the dishwasher of a present Example. The enlarged view of the circumference | surroundings of the installation part of the optical sensor in the dishwasher of another Example. The schematic diagram which shows the detection operation of the optical sensor in the dishwasher of another Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Housing 2 ... Washing | cleaning cabinet 3, 4 ... Door 5 ... Tableware bowl 6 ... Nozzle arm 7 ... Water injection hole 8 ... Water storage tank 9 ... Circulation port 12 ... Cleaning and drainage pump 12a ... Pump motor 13 ... Suction port 14 ... Discharge port 15 ... water passage 16 ... heater 19 ... water level sensor 18 ... operation panel 24 ... dry air passages 30, 50 ... light sensors 31, 51 ... light emitting parts 32, 52, 53 ... light receiving part 40 ... control part 41 ... inverter drive Unit 42 ... Load drive unit 43 ... Temperature sensor 44 ... Temperature sensor 45 ... Water supply valve 46 ... Fan motor

Claims (5)

In a dishwasher that cleans dishes by storing water at the bottom of a washing cabinet that houses dishes and sucking the stored water by a washing pump and spraying it toward the dishes,
Foam detection means for detecting the degree of foaming by the detergent water stored in the washing cabinet,
Operation control means for controlling the operation of the washing pump at the initial stage of the washing operation so that the jet of water toward the dishes becomes weaker than in the subsequent washing operation;
Detergent determination means for detecting the degree of foaming under a situation where water injection by the operation control means is weak, by the foam detection means, and determining the type of detergent according to the detection result;
A dishwasher characterized by comprising:   When determining the type of detergent, the rotational speed of the motor that is the driving source of the cleaning pump is set higher than that during the washing operation, and the driving time is set shorter than that during the washing operation, and the washing pump is mainly driven by the stirring action of the impeller of the washing pump. 2. The dishwasher according to claim 1, wherein foaming occurs in the dishwasher.   When determining the type of detergent, the rotational speed of the motor, which is the drive source of the washing pump, is set lower than that during washing operation, and the momentum of water sprayed into the washing cabinet is weak so that it does not easily reach tableware. The dishwasher according to claim 1. In a dishwasher that cleans dishes by storing water at the bottom of a washing cabinet that houses dishes and sucking the stored water by a washing pump and spraying it toward the dishes,
A water level detection means for detecting that the water level of the stored water in the washing cabinet is a predetermined water level lower than the final washing water level;
Water supply means for supplying water into the washing cabinet up to a predetermined water level detected by the water level detection means;
A foam amount determining means for operating the cleaning pump in a state where the detergent water at the predetermined water level is stored in the bottom of the cleaning cabinet, and determining the degree of foaming generated at that time;
A dishwasher characterized by comprising:   The dishwasher according to claim 4, further comprising operation control means for determining a drainage amount and / or an additional water supply amount of the detergent water stored in the bottom of the washing cabinet according to a determination result by the foaming amount determination unit. .

Images