JP4129412B2 - Dishwasher - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dishwasher that saves water.
[0002]
[Prior art]
The dishwasher is configured to wash the dishes in the washing tank by pumping water in the washing tank with a washing pump and ejecting the water from the spray nozzle (see, for example, Patent Document 1). In this case, the cleaning water ejected from the injection nozzle is repeatedly circulated after being stored in the cleaning tank and then ejected from the injection nozzle again through the cleaning pump. Therefore, the amount of water used in the dishwasher can be less than when washing dishes.
[0003]
[Patent Document 1]
JP-A-10-117996
[0004]
[Problems to be solved by the invention]
However, with the recent increase in consumer awareness of water saving, a dishwasher that further reduces the amount of water used is desired. However, if the amount of water used is reduced uniformly, the cleaning performance may be lowered, and depending on the degree of tableware contamination, a sufficient cleaning effect cannot be expected.
[0005]
This invention is made | formed in view of the said situation, The objective is to provide the dishwasher which can suppress the amount of water used low, and can suppress the fall of washing | cleaning performance as much as possible.
[0006]
[Means for Solving the Problems]
A dishwasher according to claim 1 of the present invention includes a washing tank for storing tableware, a water supply device for supplying water into the washing tank, and water stored in the washing tank. Pumped by washing pump and pump motor A cleaning device that sprays the tableware to wash the tableware, a drying device that dries the tableware by circulating air in the cleaning tank, and a cleaning step and a rinsing step by driving the cleaning device and the drying device The drying process plural Control means for executing the driving course; Detecting means for detecting the rate of change of the input current value of the pump motor; and determining means for determining whether air is entrained in the cleaning pump based on the rate of change. With
The water level in the washing tank in the washing step and the rinsing step is determined by the control means. The operation course in the standard mode that becomes the standard water level and the operation course in the water-saving mode that makes the water level lower than the standard mode; To be selectively runnable In addition, when the water-saving mode is set, when it is determined that air is entrained in the washing pump, the rotation of the pump motor is performed while applying feedback so that the input current value of the pump motor becomes normal. To reduce the number It is characterized by that.
[0007]
According to the said structure, the driving course of the water level according to the grade of the stain | pollution | contamination of tableware can be performed. In other words, when the level of tableware stains is light, it is possible to reduce the amount of water used by executing the operation course at a low water level, and when the level of tableware contamination is severe, it is sufficient to execute the operation course at a high water level. Clean performance can be obtained.
[0008]
The dishwasher according to claim 2 of the present invention comprises a dirt detecting means for detecting dirt in the water stored in the washing tank, and when the dirt in the washing water is detected by the dirt detecting means, the control means Is characterized by switching the water level in the cleaning tank to a high water level and executing the operation course.
[0009]
According to the above configuration, it is possible to prevent the problem that the low water level operation course is executed even though the degree of stains on the tableware is severe, and the cleaning power is insufficient.
[0010]
In the dishwasher according to claim 3 of the present invention, the washing apparatus is composed of a washing pump and a pump motor for pumping up water stored in the washing tank, and the control means is high when executing a low water level operation course. The pump motor is driven such that the duty ratio of the rotational speed or the operating time is lower than when the water level operation course is executed.
[0011]
When the water level in the cleaning tank is low, air is entrained and idled when the cleaning pump draws up water, and thus there is a problem that abnormal noise is generated and the life of the pump motor is reduced. In the above configuration, when the water level in the cleaning tank is low, the rotation ratio of the pump motor or the duty ratio of the operation time is reduced, so that it is possible to prevent the cleaning pump from entraining air when pumping up water.
[0012]
In this case, the operation time of the pump motor is longer in the low water level operation course than in the high water level operation course in order to compensate for the decrease in pump performance due to the lowering of the pump motor speed or the duty ratio of the operation time. If comprised in this way (invention of Claim 4), sufficient detergency can be ensured.
[0013]
Further, the cleaning device includes a plurality of injection nozzles, a cleaning pump that pumps water stored in a cleaning tank and pumps the water to the spray nozzle, and a switching unit that switches a pumping path from the cleaning pump to the spray nozzle. In addition, the control means may be configured to cause the switching means to switch the pumping path when a low water level operation course is executed (invention of claim 5).
[0014]
According to the said structure, the water pumped from the washing pump is injected in order from a some injection nozzle. Therefore, even when the circulating water amount is reduced by lowering the rotational speed of the pump motor or the duty ratio of the operation time, it is possible to prevent the injection speed from each injection nozzle from being reduced.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 to 3, the dishwasher 1 according to the present embodiment includes a washing machine body 5 having a washing tank 6 therein, an opening of the washing tank 6 provided on the front surface of the washing machine body 5. A lower door 2 and an upper door 3 for opening and closing 8 and an operation panel 4 provided at the lower part of the lower door 2 are provided. The doors 2 and 3 are pivotally supported by the cleaning machine body 5 at the upper end and the lower end, respectively. Both doors 2 and 3 are configured to rotate in conjunction with each other via a link mechanism (not shown). When the lower door 2 is opened and closed, the upper door 3 is opened and closed almost simultaneously.
[0020]
A handle 9 and a release button 10 for a door lock mechanism (not shown) are provided on the front surface of the lower door 2, and a detergent container 40 is provided on the rear surface. The upper door 3 is provided with an exhaust port 11 for discharging water vapor in the cleaning tank 6.
[0021]
The operation panel 4 includes a start switch 12 also serving as a temporary stop switch, a course setting switch 13 for setting various operation courses, a condition setting switch 14 for setting conditions for a cleaning process and a drying process, and an operation. A display unit 15 for displaying the situation and the like is provided.
[0022]
On the other hand, at the bottom of the cleaning tank 6, there are provided a sheathed heater 17 and a protective cover 18 made of a porous plate covering the sheathed heater 17, and a water storage section 6a that also serves as a drainage section. The water reservoir 6a is watertightly connected to an opening 6b provided at the bottom of the cleaning tank 6, and a filter 21a is attached to the upper part thereof. A filter 21b is attached to the top of the opening 6b. The filter 21a is finer than the filter 21b.
[0023]
Two spray arms 19 (corresponding to spray nozzles) are provided in the lower part of the cleaning tank 6. The injection arm 19 has a hollow shape, and a plurality of injection holes 19a are provided on the upper surface thereof. The base end portion of the spray arm 19 is rotatably connected to a cylindrical arm support 20. Moreover, the step part 23 which supports the tableware basket 22 is provided in the left-right both sides | surfaces in the washing tank 6 (only the step part of the left side is shown in FIG. 3).
[0024]
Further, a cleaning pump 24, a drainage pump 25, and a blower 27 are disposed below the cleaning tank 6 in the cleaning machine body 5. The washing pump 24 and the drainage pump 25 are driven by a common pump motor 26. The suction port of the cleaning pump 24 is connected to the bottom of the water storage unit 6 a via a pipe 24 a, and the discharge port is connected to the arm support 20. The suction port of the drain pump 25 is connected to the bottom of the water reservoir 6 a via a pipe 25 a, and the discharge port is connected to the drain pipe 28. The blower 27 is connected to the vicinity of the sheathed heater 17 in the lower part of the cleaning tank 6 through a blower pipe 29.
[0025]
Further, a water supply pipe 30 for supplying water from a water supply source such as a water supply into the cleaning tank 6 is connected to the rear part of the cleaning tank 6 in the cleaning machine main body 5. The water supply pipe 30 is provided with a water supply valve 38.
[0026]
In the present embodiment, a drying device is constituted by the sheathed heater 17 and the blower 27. The cleaning device is constituted by the cleaning pump 24 and the pump motor 26. A water supply apparatus is constituted by the water supply pipe 30 and the water supply valve 38.
[0027]
FIG. 4 shows the electrical configuration of the dishwasher 1 as a block diagram. In FIG. 4, the control circuit 16 is mainly composed of a microcomputer and includes storage means such as a RAM and a ROM. The storage means stores a control program executed by the microcomputer.
[0028]
The control circuit 16 includes a switch input unit 31 that responds to the operation of various switches on the operation panel 4, a door switch 32 that responds to the opening and closing operation of the lower door 2, and a water temperature sensor 33 that detects the temperature of the cleaning water in the cleaning tank 6. The output signals of the standard water level sensor 34 and the low water level sensor 39 for detecting the water level in the cleaning tank 6 are given.
[0029]
Further, the control circuit 16 performs inverter control of the pump motor 26 via the inverter circuit 35. Furthermore, the control circuit 16 drives and controls the blower 27, the sheathed heater 17, the display unit 15, the indicator 37, and the water supply valve 38 via the drive circuit 36.
[0030]
Here, the water level sensors 34 and 39 will be described. The dishwasher 1 which concerns on a present Example is equipped with two water level modes from which the water level in the washing tank 6 in a washing | cleaning process and a rinse process differs can be selectively performed. One of these water level modes is a standard mode, and the other is a water-saving mode with a water level lower than that of the standard mode.
[0031]
The condition setting switch 14 includes a switch for setting a water-saving mode. When various automatic operation courses are executed in a state where the water-saving mode is set, the control circuit 16 sets the water level in the cleaning tank 6. The washing step and the rinsing step are carried out with a low water level. On the other hand, when the automatic operation course is executed without setting the water-saving mode, the control circuit 16 executes the cleaning process and the rinsing process with the water level in the cleaning tank 6 set to the standard water level.
[0032]
The automatic operation course is a course for automatically executing a series of steps from the cleaning process to the drying process, and the user sets an arbitrary course from a plurality of automatic operation courses by the course setting switch 13. Can do. That is, in the present embodiment, a plurality of automatic driving courses having different water levels can be selectively executed by a combination of the course setting switch 13 and the condition setting switch 14 for setting the water saving mode.
[0033]
Therefore, in this embodiment, a standard water level sensor 34 and a low water level sensor 39 are provided as water level sensors for detecting the water level corresponding to the standard mode and the water saving mode. The configuration of the standard water level sensor 34 and the low water level sensor 39 will be described with reference to FIGS. As shown in FIG. 5, a water tank 41 is provided adjacent to the cleaning tank 6. The water tank 41 is provided with an air hole 41a at the top, and a communication pipe 42 connected to the bottom of the water reservoir 6a is provided at the bottom. As a result, the water in the water storage section 6a enters and exits into the water tank 41 according to the water level in the cleaning tank 6, and the water level in the water tank 41 changes.
[0034]
As shown in FIG. 6, a standard water level float 43 and a low water level float 44 are accommodated in the water tank 41. A standard water level sensor 34 and a low water level sensor 39 made of microswitches are fixed to the upper part of the water tank 41 via a substrate 47. Between the floats 43 and 44 and the water level sensors 34 and 39, substantially L-shaped rotating arms 48 and 49 are arranged, respectively.
[0035]
When the water level in the water tank 41 rises as the water level in the washing tank 6 reaches the standard water level indicated by the alternate long and short dash line A in FIG. 5, the float 43 rises and the rotating arm 48 rotates. As a result, the microswitch as the standard water level sensor 34 is switched from on to off. On the other hand, when the water level in the water tank 41 rises as the water level in the cleaning tank 6 reaches the low water level indicated by the alternate long and short dash line B in FIG. 5, the float 44 floats and the rotating arm 49 is rotated. . As a result, the microswitch as the low water level sensor 39 is switched from on to off. That is, the water level in the washing tank 6 is detected by detecting the water level in the water tank 41.
[0036]
Next, the operation of this embodiment will be described with reference to FIGS. First, a standard automatic driving course (hereinafter referred to as “standard course”) executed by the control circuit 16 will be described with reference to FIG. After the standard course is set by the course setting switch 13, when the start switch 12 is instructed to start the operation, the control circuit 16 performs the cleaning process, the first and second rinsing processes, the heating rinsing process, and the drying process. Run in order.
[0037]
In the cleaning process and each rinsing process, the water supply valve 38 is opened to supply water into the cleaning tank 6, and the cleaning pump 24 is operated to wash out water in the water storage section 6 a from the spray arm 19 or rinse. The operation and the drainage operation of operating the drainage pump 25 to discharge the water in the water storage section 6a are sequentially executed.
[0038]
In the cleaning process and the heating and rinsing process, the control circuit 16 causes the sheathed heater 17 to generate heat during the water supply operation. Based on the input from the water temperature sensor 33, the control circuit 16 causes the sheathed heater 17 to intermittently generate heat so that the water temperature in the cleaning tank 6 becomes about 65 ° C.
[0039]
At this time, if the “water saving mode” is not set by the condition setting switch 14, the control circuit 16 executes the cleaning process and the rinsing process in the standard mode. That is, the control circuit 16 performs a water supply operation until the standard water level sensor 34 detects that the water level in the cleaning tank 6 has reached the standard water level. As a result, about 3.5 L of water is stored in the cleaning tank 6. At this time, the control circuit 16 drives the pump motor 26 continuously.
[0040]
On the other hand, when the “water-saving mode” is set by the condition setting switch 14, the control circuit 16 executes the cleaning process and the rinsing process in the water-saving mode, as shown in FIG. That is, the control circuit 16 is a low water level sensor. 39 Thus, the water supply operation is executed until it is detected that the water level in the cleaning tank 6 has reached the low water level. As a result, about 2.5 L of water is stored in the cleaning tank 6. At this time, the control circuit 16 is driven intermittently so that the duty ratio (operation ratio) of the operation time of the pump motor 26 is, for example, 2 seconds ON / 1 seconds OFF.
[0041]
Here, the reason why the duty ratio of the operation time of the pump motor 26 in the water saving mode is set to 2 seconds ON / 1 second OFF will be described with reference to FIG. FIG. 8 shows the relationship between the duty ratio of the pump motor 26 and the maximum water level and the minimum water level when water is supplied to the cleaning tank 6 to a low water level.
[0042]
The dishwasher 1 is configured to inject the water in the cleaning tank 6 into the cleaning tank 6 from the injection arm 19 while pumping up the water in the cleaning pump 24. Therefore, if the pumping time of the cleaning pump 24 is long, the cleaning is performed accordingly. The water level in the tank 6 falls. As shown in FIG. 8, in the dishwasher 1 according to the present embodiment, when the operation time (ON time) of the cleaning pump 24 is 3 seconds, the rest time (OFF time) is any one of 1 to 3 seconds. The water level in the cleaning tank 6 is “0”. When the water level in the cleaning tank 6 becomes “0”, air is entrained in the cleaning pump 24 and idles, so that abnormal noise is generated and the life of the pump motor 26 is reduced.
[0043]
On the other hand, when the operation time of the cleaning pump 24 is 1 second and 2 seconds, the water level does not become “0”. However, in terms of detergency, it is better that the ratio of operation time to rest time is high. Therefore, in this embodiment, the duty ratio in the water-saving mode is set to 2 seconds ON / 1 second OFF.
[0044]
In the drying process, hot air is circulated in the cleaning tank 6 by operating the blower 27 while intermittently generating heat in the sheathed heater 17.
[0045]
As described above, according to this embodiment, the switch for setting the water saving mode is provided, and when the water saving mode is set, the automatic operation course is executed at a low water level, and when the water saving mode is not set, that is, in the standard mode. Sometimes an automatic driving course is executed at the standard water level. Therefore, the user can select the amount of water used according to the degree of dirt on the tableware, and can reduce the amount of water used as a whole.
[0046]
In this embodiment, the operation ratio of the pump motor 26 in the water saving mode is lowered. Therefore, it is possible to prevent the cleaning pump 24 from entraining air due to the low water level in the cleaning tank 6. In particular, in this embodiment, since the operating ratio is set high in a range in which air is not involved, it is possible to suppress a reduction in cleaning power due to the reduction of the operating ratio.
[0047]
FIG. 9 shows a second embodiment of the present invention, and different points from the first embodiment will be described. The same parts as those in the first embodiment are denoted by the same reference numerals. In the second embodiment, the control method of the pump motor 26 in the water-saving mode is different from the first embodiment.
[0048]
Specifically, when the water saving mode is set, the control circuit 16 detects the pump motor current value every predetermined time (0.1 second), and determines whether or not air has been caught in the cleaning pump 24 by the change. I have to. When it is determined that air has been entrained, the rotational speed of the pump motor 26 is reduced while feedback is applied so that the motor current value becomes normal. That is, in this embodiment, the control circuit 16 functions as a detection unit and a determination unit.
[0049]
FIG. 9 is experimental data showing changes in the motor current value when the cleaning pump 24 is in operation. As shown in FIG. 9, the motor current value when air is not involved is approximately 1.4 A, whereas when the air is involved, the motor current value decreases to about 1.18 to 1.3 A. . Therefore, it is possible to detect that air has been caught by a change in the motor current value.
[0050]
According to such a configuration, it is possible to suppress a reduction in cleaning performance as much as possible while preventing air from being caught in the pump motor 26 in the water-saving mode.
[0051]
Moreover, it can respond to the water level fluctuation | variation which changes according to the installation condition of the dishwasher 1, or the water level fluctuation | variation by the dispersion | variation between products. Specifically, if the dish washer 1 is installed in a state slightly inclined in the front-rear direction or the left-right direction so that the side on which the water storage unit 6a is provided becomes higher, the water level in the water storage unit 6a decreases. Air is easily caught in the cleaning pump 24. On the contrary, if the dishwasher 1 is installed in an inclined state so that the side on which the water storage section 6a is provided is lowered, the water level in the water storage section 6a rises, so that it is difficult for air to be caught in the cleaning pump 24. In such a case, it is not necessary to reduce the rotational speed of the pump motor 26 even in the water-saving mode.
[0052]
Therefore, if the rotational speed of the pump motor 26 is uniformly reduced in the water-saving mode, the pump capacity is unnecessarily lowered until there is no risk of air being involved. On the other hand, in this embodiment, the rotational speed of the pump motor 26 is reduced only when air entrainment is detected, and the rotational speed of the pump motor 26 is reduced to a minimum level that can eliminate air entrainment. Therefore, it is possible to suppress a reduction in cleaning power in the water-saving mode as much as possible.
[0053]
FIG. 10 shows a third embodiment of the present invention, and the differences from the first embodiment will be described. The same parts as those in the first embodiment are denoted by the same reference numerals. In the third embodiment, a switching valve 52 (corresponding to switching means) is provided at the branch of the pressure feed path 51 that connects the discharge port of the cleaning pump 24 and the arm support 20 of each injection arm 19.
[0054]
One inlet of the switching valve 52 is connected to the discharge side of the cleaning pump 24, and two outlets are connected to each arm support 20. The switching valve 52 can be switched between a fully open state in which two outlets are opened and a half-open state in which one of the outlets is opened.
[0055]
The control circuit 16 opens both outlets of the switching valve 52 when the water-saving mode is not set, that is, when the automatic operation course is executed in the standard mode (fully opened state). As a result, water is jetted from both jet arms 19 simultaneously.
[0056]
On the other hand, when executing the automatic operation course with the water-saving mode set, the control circuit 16 continuously rotates the pump motor 26 at a lower speed than the standard mode and alternately opens the outlets of the switching valve 52. Let As a result, the two injection arms 19 alternately inject water. FIG. 10 shows a state in which the outlet on the right side of the switching valve 52 is opened.
[0057]
Thus, in this embodiment, the pump motor 26 is driven at a lower speed in the water-saving mode than in the standard mode. For this reason, the cleaning pump 24 does not involve air. In addition, in the water-saving mode, since the jet arms 19 are configured to jet water alternately, it is possible to suppress a decrease in the jet speed of the water from the jet arms 19 due to the pump motor 26 being driven at a low speed. Can be suppressed as much as possible.
[0058]
11 and 12 show a fourth embodiment of the present invention, and differences from the first embodiment will be described. The same parts as those in the first embodiment are denoted by the same reference numerals. As shown in FIG. 11, in the fourth embodiment, two water level sensors 34, 39 Instead of this, the water level in the cleaning tank 6 is detected by one water level sensor 61. The water level sensor 61 is configured to detect the water level in the water-saving mode.
[0059]
FIG. 12 is a flowchart of the water supply operation executed by the control circuit 16. In FIG. 12, the control circuit 16 determines whether or not the water saving mode is set (step S1). When the water saving mode is set (YES), the process proceeds to step S2 and the water supply valve 38 is opened. To do. When water level sensor 61 detects that the water level in cleaning tank 6 has reached a low water level (YES in step S3), water supply valve 38 is closed and the water supply operation is terminated.
[0060]
On the other hand, when the water-saving mode is not set (NO in step S1), the process proceeds to step S4 and the water supply valve 38 is opened. When the water level sensor 61 detects that the water level in the cleaning tank 6 has reached a low water level (YES in step S5), measurement of the time t is started (step S6). In step S7, it is determined whether or not the time t after reaching the low water level has passed a time T (for example, 6 seconds). When the time T has passed (YES), the water supply valve 38 is closed to supply water. The operation is terminated (step S8).
[0061]
The time T is a time required for the water level in the cleaning tank 6 to reach the standard water level after reaching the low water level, and is stored in the control circuit 16 in advance.
[0062]
According to such a configuration, one water level sensor can be provided, and the product cost can be reduced.
[0063]
FIG. 13 shows a fifth embodiment of the present invention, and differences from the fourth embodiment will be described. The same parts as those in the fourth embodiment are denoted by the same reference numerals. In the fifth embodiment, the time required to reach the standard water level after reaching the low water level (additional water supply time) T1 is set based on the time required to reach the low water level.
[0064]
Specifically, as shown in FIG. 13, when it is determined that the water-saving mode is not set in step S1 (YES), the control circuit 16 opens the water supply valve 38 (step S4) and the water supply time Measurement of t1 is started (step S11).
[0065]
When the water level sensor 61 detects that the water level in the cleaning tank 6 has reached a low water level (YES in step S5), the measurement of the water supply time t1 is terminated (step S12). Then step S In 13, the water supply speed is obtained from the time t1 and the amount of water at the low water level, and the additional water supply time T1 until the water level in the cleaning tank 6 reaches the standard water level is calculated.
[0066]
In step S6, the time t after reaching the low water level is measured, and when it is determined that the time t has passed the time T1 (step S14), the water supply valve 38 is closed and the water supply operation is terminated (step S8). ). The water supply operation in the water saving mode is the same as that in the fourth embodiment.
[0067]
According to such a structure, even if it is a case where a water supply speed changes with households using the dishwasher 1, it can supply water to a high water level correctly.
[0068]
FIG. 14 shows a sixth embodiment of the present invention, and the differences from the fourth embodiment will be described. The same parts as those in the fourth embodiment are denoted by the same reference numerals.
[0069]
In the sixth embodiment, the water level sensor 61 is configured to detect the standard water level, and calculates the time required to reach the low water level based on the time to reach the standard water level.
[0070]
Specifically, when the execution of the water supply operation is started, the control circuit 16 adds “1” to the previous water supply operation number N (step S21), and when N is “1” (step S21). In step S23, S24, the water supply valve 38 is opened and measurement of the water supply time t2 is started. In the next step S25, the water level sensor 61 determines whether or not the water level in the cleaning tank 6 has reached the standard water level. When the water level reaches the standard water level (YES), the water supply valve 38 is closed to end the water supply operation, and the measurement of the water supply time t2 is ended (steps S26 and S27).
[0071]
Subsequently, the control circuit 16 calculates a water supply speed based on the water supply time t2 (step S28). Then, the water supply time T2 from the water supply speed to the low water level to the low water level is calculated and stored (step S29).
[0072]
On the other hand, when N is not “1” (NO in step S21), it is determined whether or not the water-saving mode is set in the next step S30. When the water saving mode is set (Yes), the water supply valve 38 is opened and the measurement of the water supply time t is started (steps S31 and S32). When the water supply time t reaches time T2 (step S33), the water supply valve 38 is closed and the water supply operation is terminated (step S34).
[0073]
If it is determined in step S30 that the water-saving mode is not set (NO), the water supply valve 38 is opened (step S35). When the water level sensor 61 detects that the water level in the cleaning tank 6 has reached the standard water level (step S36), the water supply valve 38 is closed and the water supply operation is terminated (step S34).
[0074]
In step S37, the control circuit 16 determines whether or not the water supply operation number N has reached a predetermined number M. When the predetermined number M is reached (NO), the water supply operation number N is set to “0” (step S38). On the other hand, when the number N of water supply operations is smaller than the predetermined number M, the process is terminated as it is.
[0075]
Thus, even when the water level sensor 61 is configured to detect that the water level in the cleaning tank 6 has reached the standard water level, the water supply operation is performed so that the water level in the cleaning tank 6 becomes a low water level. Can be executed.
[0076]
In the present embodiment, the water supply time T2 until the low water level is reached is configured to be updated regularly (in this embodiment, every time the number of water supply operations reaches M). With such a configuration, for example, even when the water supply operation is repeatedly performed and the inside of the water supply pipe 30 or the like becomes dirty and the water supply speed changes, the accurate water supply time up to the low water level can be set.
[0077]
FIG. 15 shows a seventh embodiment of the present invention, and differences from the first embodiment will be described. The same parts as those in the first embodiment are denoted by the same reference numerals. In the seventh embodiment, an output signal of a dirt sensor 71 (corresponding to a dirt detecting means) for detecting dirt of water circulating in the cleaning tank 6 is supplied to the control circuit 16.
[0078]
The dirt sensor 71 is composed of, for example, a light receiving element and a light emitting element disposed to face each other in the water storage section 6a.
[0079]
When executing the automatic operation course in the water-saving mode, the control circuit 16 determines whether or not the water in the cleaning tank 6 is dirty based on the output signal given from the dirt sensor 71. And when it judges that it is dirty, it switches to standard mode and continues an automatic driving course. That is, the water level in the cleaning tank 6 in the cleaning process and each rinsing process is switched to the standard water level. The pump motor 26 is continuously driven.
[0080]
If the automatic operation course is executed in the water-saving mode even though the tableware is very dirty, the cleaning power is insufficient and the tableware cannot be sufficiently cleaned. According to the above configuration, it is possible to eliminate the problem that the cleaning power is insufficient.
[0081]
The present invention is not limited to the above-described embodiments, and for example, the following modifications are possible.
In the second embodiment, when the occurrence of air entrainment in the cleaning pump is detected, the water supply valve 38 is opened for several seconds, and several hundred ml of water is additionally supplied into the cleaning tank so as to raise the water level. It may be configured.
[0082]
The calculation of the low water level water supply time T2 in the sixth embodiment may be performed by multiplying the water supply time t2 by a preset coefficient x (0 <x <1). Moreover, you may comprise so that a coefficient may be reset every time the frequency | count of water supply operation | movement reaches a predetermined number of times.
[0083]
When the operation ratio and the number of rotations of the pump motor in the water-saving mode are made lower than those in the standard mode, it is preferable to lengthen the time of the cleaning process or the rinsing process or raise the temperature of the cleaning water. With such a configuration, it is possible to ensure the cleaning power in the water-saving mode.
[0084]
Depending on the automatic driving course, the setting of the water-saving mode may not be accepted, or even when the water-saving mode is set, the mode may be automatically changed to the standard mode. For example, if the water-saving mode is set in an automatic operation course (so-called “Ganko Dirt” course) for washing dishes with a high degree of dirt, the effect of the automatic operation course cannot be sufficiently obtained. Accordingly, in such an automatic driving course, it is preferable that the automatic operation course is executed in the standard mode even when the water saving mode is set.
[0085]
In the above-described embodiment, the switch for setting the water-saving mode is provided, but the water level of the cleaning tank may be set in advance for each operation course. That is, in this case, the water level is automatically set by setting the driving course.
[0086]
The water level in the washing tank is not limited to two types, that is, a low water level and a high water level, and may be configured so that it can be selected from three or more water levels.
[0087]
【The invention's effect】
As is apparent from the above description, the present invention is configured so that a plurality of operation courses having different water levels in the cleaning tank in the cleaning process and the rinsing process can be selectively executed, and the operation at the water level according to the degree of contamination of the tableware. Since the course can be executed, it is possible to reduce the amount of water used while maintaining the cleaning performance according to the degree of dirt on the tableware.
[Brief description of the drawings]
FIG. 1 is an external perspective view showing the overall configuration of a dishwasher according to a first embodiment of the present invention.
FIG. 2 is a perspective view of the dishwasher shown with the door open.
[Figure 3] A vertical side view of a dishwasher
FIG. 4 is a block diagram showing a schematic electrical configuration of the dishwasher
FIG. 5 shows a water level detection mechanism.
FIG. 6 is a diagram showing the configuration of a water tank
7A is a diagram showing both the water level in the standard mode and the process of the standard course. FIG. 7B is a diagram showing both the water level in the water-saving mode and the process of the standard course.
FIG. 8 is a diagram for explaining the operating rate of the pump motor in the water-saving mode
FIG. 9 shows a second embodiment of the present invention and is a diagram for explaining a change in a motor current value when air is caught in a cleaning pump.
FIG. 10 shows the third embodiment of the present invention, and is a diagram for explaining the water injection operation from the injection arm in the water-saving mode.
FIG. 11 is a view corresponding to FIG. 4 showing a fourth embodiment of the present invention.
FIG. 12 is a flowchart showing a water supply operation.
FIG. 13 is a view corresponding to FIG. 12 showing a fifth embodiment of the present invention.
FIG. 14 is a view corresponding to FIG. 12, showing a sixth embodiment of the present invention.
FIG. 15 is a view corresponding to FIG. 4 showing a seventh embodiment of the present invention.
[Explanation of symbols]
In the figure, 1 is a dishwasher, 6 is a washing tank, 16 is a control circuit (control means, detection means, judgment means), 17 is a sheathed heater (drying device), 19 is an injection arm (injection nozzle), and 24 is cleaning. Pump (cleaning device), 26 is a pump motor (cleaning device), 27 is a blower (drying device), 30 is a water supply pipe (water supply device), 38 is a water supply valve (water supply device), 51 is a pressure feed path, and 52 is a switching valve (Switching means) 71 is a dirt sensor (dirt detection means).

Claims (5)

A washing tank for storing tableware, a water supply device for supplying water into the washing tank, a washing device for pumping water stored in the washing tank by a washing pump and a pump motor and spraying the tableware to wash the tableware, A drying device that dries the tableware by circulating air in the washing tank, and a control means that executes a plurality of operation courses including a washing step, a rinsing step, and a drying step by driving the washing device and the drying device. If, e Bei detecting means for detecting a rate of change of the input current value of the pump motor, and a determination means for determining whether the air in the washing pump based on the rate of change is involved,
The control means selectively executes the operation course in the standard mode in which the water level in the washing tank in the cleaning process and the rinsing process is a standard water level and the operation course in the water-saving mode in which the water level is lower than the standard mode. In the case where the water saving mode is set, when it is determined that air is entrained in the washing pump, feedback is applied so that the input current value of the pump motor becomes normal. A dishwasher characterized in that the number of rotations of the pump motor is reduced . Provided with a dirt detection means for detecting dirt in the water stored in the washing tank,
2. The dishwasher according to claim 1, wherein when the dirt of the washing water is detected by the dirt detecting means, the control means switches the water level in the washing tank to a high water level and executes the operation course. . Control means is configured so as when performing a low-level operation course of the duty ratio of the rotation speed or operation time than when performing the high-level operation course of driving the port Npumota to be lower The dishwasher according to claim 1.   4. The dishwasher according to claim 3, wherein the low water level operation course is configured such that the operation time of the pump motor is longer than that of the high water level operation course. The cleaning device includes a plurality of injection nozzles, a cleaning pump that pumps water stored in the cleaning tank and pumps the water to the spray nozzle, and a switching unit that switches a pumping path from the cleaning pump to the spray nozzle. Configured ,
Control means, dishwashing machine according to claim 3, wherein it is configured so as to switch the pumping path to said switching means when performing the low-level operation courses.

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