JP3572218B2 - Dishwasher - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a dishwasher provided with a drainage pump for discharging washing water in a washing tank out of the washing machine.
[0002]
[Problems to be solved by the invention]
2. Description of the Related Art Conventionally, in a dishwasher, it is general to use a pump driven at a constant rotation speed by an induction motor as a drainage pump for discharging washing water out of the machine.
[0003]
However, in such a configuration in which the drainage pump is always operated at the same rotation speed, noise during drainage operation may be relatively large, and particularly at the end of the drainage operation (wash water in the washing tank is reduced. When the drainage pump is engulfed with air and idles (when the washing water runs out), the noise sometimes becomes abnormally loud. In addition, because the drainage capacity is constant, for example, dishwashing courses that reduce the time required for drainage while allowing for increased noise during drainage operation (that is, dishwashing can be completed in a short time even if the noise is slightly high) Dishwashing course) or a dishwashing course with reduced noise is difficult to set, and this is an obstacle to multifunctional dishwashers.
[0004]
Further, in the dishwasher, a pump unit configured to drive the impeller for a washing pump for discharging the washing water in the washing tank toward the dish and the impeller for the drainage pump with one motor is used. That is widely done. When such a pump unit having a one-motor configuration is used, the washing pump functions when the motor rotates forward and the drainage pump functions when the motor rotates reversely. However, the impeller on the non-use side always has a simple rotational resistance. Will act as In this case, the size of each impeller of the cleaning pump and the drainage pump is uniquely determined in a state where the required capacity can be exerted at a constant rotation speed, regardless of the frequency of use of forward rotation / reversal of the motor. It is impossible to set the optimum rotation speed and shape to reduce the rotation loss, and this causes a problem that the pump operation efficiency is reduced. In addition, since the rotation speed of the drainage pump is inevitably increased more than necessary, there is a problem that the noise when the above-mentioned air turbulence occurs at the end of the drainage operation becomes abnormally large.
[0005]
The present invention has been made in view of the above circumstances, and an object thereof is to realize a reduction in drainage noise and a reduction in drainage required time as necessary.It can also be multifunctional withIt is an object of the present invention to provide a dishwasher having the above effects.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is:A dishwashing course is set as a standard course for executing a washing step, a rinsing step, a heating rinsing step, and a drying step in this order, and a silent course for executing the same steps as those of the standard course while suppressing operation noise.In the dishwasher, a washing tank for storing dishes, a washing pump for discharging washing water supplied to the washing tank toward the stored dishes, and washing water in the washing tank. A drain pump for discharging to the outside of the machine, a control unit for controlling a washing operation and a rinsing operation by the cleaning pump, a drain operation by the drain pump, and a drain pump driving unit for driving the drain pump at a variable speed. In addition to the above, the control unit performs a rotation speed change control for changing the rotation speed of the drain pump through the drain pump driving unit during the drain operation, and the content of the rotation speed change control is executed. It is configured to change according to the type of dishwashing course.
[0007]
According to this configuration, by setting the control program by the control unit in advance, it is possible to arbitrarily change the rotation speed of the drain pump during the drain operation through the drain pump driving unit. With this, when noise reduction during drainage operation is required, the request can be dealt with by performing control to reduce the rotation speed of the drainage pump. When it is required to reduce the time, the request can be dealt with by increasing the rotation speed of the drainage pump and performing control to increase the drainage capacity. In addition, since the content of the rotation speed change control as described above can be changed according to the type of the dishwashing course to be executed, noise during drainage operation is suppressed.SilentThe time required for drainage was shortened while allowing the course or its noisestandardIt is possible to make the dishwasher multifunctional, for example, by setting a course.
[0013]
Claim2The described invention includes a cleaning pump driving unit for driving the cleaning pump at a variable speed, and a case in which the control unit performs control of changing the rotation speed of the cleaning pump through the cleaning pump driving unit. In addition, control is performed to change the rotation speed of the drainage pump through drainage pump driving means in conjunction with the rotation speed of the washing pump.
According to this configuration, by setting a control program by the control unit in advance, the rotation speed of the cleaning pump for performing the washing operation and the rinsing operation can be arbitrarily changed through the cleaning pump driving unit. In addition, the rotation speed of the drainage pump can be automatically changed to an optimum state in conjunction with the rotation speed of the washing pump. This makes it possible to easily set the performance of the washing pump and the drainage pump to optimal conditions, respectively, so that the noise during the draining operation or the time required for draining is reduced, and at the same time the noise during the washing operation and the rinsing operation is reduced. And shortening the time required for cleaning, etc. can be realized at the same time.
[0015]
Claim3The invention described above has a configuration in which the control means has a built-in clock function, and at the time of executing the drain operation, controls at least the rotation speed of the drain pump through the drain pump driving means based on time information obtained by the clock function. The configuration is such that:
According to this configuration, it is possible to automatically perform control to change the rotation speed of the drainage pump during a time period when the operation noise is not annoying and a time period when the operation noise is annoying. The troublesome operation of changing the number of rotations of each one can be omitted.
[0017]
Claim4In the invention described above, the control unit is configured to perform control to reduce the rotation speed of the drain pump during a period in which another load is simultaneously energized while the drain pump is operating.
According to this configuration, the peak value of the power consumption is suppressed, and the capacity of the drain pump can be maximized in cooperation with the energized state of the other load within the limited current capacity. Become like
[0019]
According to this configuration, it is only necessary to provide one motor, and the entire configuration can be simplified. Further, it is possible to easily change the performance of the washing pump and the drain pump only by changing the number of rotations of the motor at the time of forward rotation and at the time of reverse rotation.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
(First Embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. First, in FIGS. 2 and 3, a washing tank 2 is provided inside a main body 1 of the dishwasher, and a door 3 whose lower part is supported by the main body 1 is provided at the front of the main body 1 so as to be rotatable. The front of the washing tank 2 is opened and closed by the door 3. A heater 4 is provided at the bottom of the cleaning tank 2, and cleaning arms 5 and 6 are provided at a lower portion and an upper portion of the cleaning tank 2, and tableware is provided above each of the cleaning arms 5 and 6. Cars 7 and 8 are housed so that they can be pulled out.
[0021]
The deepest part on the front side of the bottom of the washing tank 2 is a water storage section 9, and a cleaning pump 10 and a drainage pump 11 are disposed behind the water storage section 9. In this case, the cleaning pump 10 and the drainage pump 11 use a common pump motor 12 as a drive source. The pump motor 12 is constituted by, for example, a DC brushless motor, and is driven at a variable speed by an inverter circuit 13 (see FIG. 5: corresponding to the washing pump driving means and the drainage pump driving means in the present invention). ing. However, as the pump motor 12, a brushed DC motor or an induction motor can be used. The pump motor 12 is configured so that the cleaning pump 10 functions by rotating forward, and the drainage pump 11 functions by rotating reversely.
[0022]
Specifically, the cleaning pump 10, the drain pump 11, and the pump motor 12 have a configuration as shown in FIG. In FIG. 4, a cleaning pump 10 and a drainage pump 11 have impellers 10b and 11b disposed coaxially in respective pump cases 10a and 11a, and connect the impellers 10b and 11b to a rotating shaft 12a of a pump motor 12. It has a structure. The pump case 10a has a suction port 10c connected to the water storage section 9 via a connection section 14, and a discharge port 10d connected to each of the suction ports (not shown) of the cleaning arms 5, 6 with a water supply section 15 and a water supply pipe. 16 is communicated. In the pump case 11a, a suction port (not shown) is connected to the water storage section 9 via a connection pipe 17, and a discharge port is connected to a drain pump 18 described later.
[0023]
In this case, the impeller 10b of the cleaning pump 10 draws the cleaning water in the cleaning tank 2 from the water storage unit 9 through the connection unit 14 when the pump motor 12 rotates forward, and transfers the suctioned cleaning water to the water supply unit 15 and the water supply pipe. The cleaning arms 5 and 6 are fed to the cleaning arms 5 and 6 by pressure. The cleaning arms 5 and 6 discharge cleaning water, which is pressure-fed from the cleaning pump 10, from ejection ports (not shown) to tableware stored in the tableware baskets 7 and 8. Further, the impeller 11b of the drain pump 11 sucks the washing water in the washing tank 2 from the water reservoir 9 through the connection pipe 17 when the pump motor 12 rotates in the reverse direction, and once pumps the sucked washing water through the drain hose 18. It is later discharged outside the machine.
[0024]
A temperature sensor 19 composed of a thermistor is provided on the lower surface of the bottom of the cleaning tank 2 at a position deviated from the water storage section 9, and the temperature sensor 19 detects the temperature of the cleaning water in the cleaning tank 2. I am trying to do it. A water level switch 20 is provided at the rear side of the lower portion of the cleaning tank 2 as a water level detecting means for detecting a water level in the cleaning tank 2. The water level switch 20 is connected to the water storage section through a connection pipe 20 a. 9 communicates with a hole 9a provided at the bottom of the base 9. As the water level switch 20, various types such as a float type and an air trap type can be used.
[0025]
A water supply valve 21 is provided at a rear portion of the cleaning tank 2, and a water supply hose 22 is connected to the water supply valve 21, and tap water (not shown) is supplied into the cleaning tank 2 through the water supply hose 22 and the water supply valve 21. It is supplied as washing water. Further, a blower 23 and a blow duct 24 are arranged at the back of the washing tank 2, and an intake duct 25 and an exhaust duct 26 are arranged above the washing tank 2. The blower 23 includes a fan motor 27 and a fan 28 that is rotated by the fan motor 27. By the blowing action of the fan 28, air outside the machine is sucked in through the intake duct 25 and the inside of the cleaning tank 2 is blown through the blow duct 24. And the air in the cleaning tank 2 is discharged to the outside through the exhaust duct 26.
[0026]
As shown in FIG. 3, a door lock lever 29 and an operation panel 30 are provided on the upper front part of the door 3. Among them, the door lock lever 29 is for locking the closed door 3, and the illustrated position is a lock position, and the lock is released by rotating to the left from this position. I have. The operation panel 30 includes a switch input unit 31 including a start switch, a display unit 32 including an LED, and the like. At the back of the operation panel 30, a control device 33 (see FIGS. 2 and 5) which constitutes a control means according to the present invention together with the inverter circuit 13 is provided.
[0027]
The control device 33 controls the overall operation of the dishwasher, and is mainly composed of a microcomputer. As shown in FIG. 5, signals from the switch input unit 31 of the operation panel 30, the water level switch 20, the door switch 34 responsive to opening and closing of the door 3, the temperature sensor 19, and the like are input to the control device 33. It has become. The control device 33 controls the display unit 32, the buzzer 35, the water supply valve 21, the heater 4, the fan motor 27, and the like via the drive circuit 36 based on the input signals and the preset control program. , The pump motor 12 is controlled via an inverter circuit 13.
[0028]
Next, the operation of the above configuration will be described.
When washing the dishes, the user first stores the dishes to be washed in the upper and lower dish baskets 7 and 8 with the door 3 opened, and stores them in the washing tank 2. The detergent is stored in a detergent feeding device (not shown) provided at a predetermined portion of the door 3. Then, when the start switch of the switch input unit 31 on the operation panel 30 is operated with the door 3 closed, the control device 33 executes the operation based on a preset control program. In addition, the above-mentioned detergent introduction device is configured to automatically supply the detergent into the cleaning tank 2 in conjunction with, for example, the operation of supplying the cleaning water into the cleaning tank 2 or the start of the cleaning process.
[0029]
FIG. 1 shows a time chart in a standard course in which the washing step, the two rinsing steps, the heating rinsing step, and the drying step are performed in this order, the change state of the temperature of the washing water in the washing tank 2 and the rotation speed of the pump motor 12. It is shown together with. In FIG. 1, the hatched portion indicates the operation state of each device. However, the time axis in FIG. 1 does not accurately reflect the time required for each process.
[0030]
When the operation is started, a cleaning step is first performed. In this cleaning step, first, a water supply operation is performed in which the water supply valve 21 is opened to supply tap water as cleaning water into the cleaning tank 2. When cleaning water is supplied into the cleaning tank 2, the water is stored in the cleaning tank 2, and the water level in the cleaning tank 2 gradually rises. When the water level in the washing tank 2 reaches a preset water level H (see FIG. 2), this is detected by the water level switch 20, and the control device 33 closes the water supply valve 21 based on the detection output. Stop the water supply operation.
[0031]
In the washing operation performed after the end of the water supply operation, the heater 4 is energized to perform the heating operation, and the pump motor 12 is rotated forward through the inverter circuit 13 to operate the washing pump 10. At this time, the rotation speed of the pump motor 12 is controlled to be, for example, 3000 rpm.
[0032]
When the cleaning pump 10 is operated in this manner, the cleaning water in the cleaning tank 2 is sucked into the cleaning pump 10 from the water storage unit 9, and the suctioned cleaning water is supplied to the cleaning arm 5 through the water supply unit 15 and the water supply pipe 16. , 6 and are discharged from the ejection holes of the washing arms 5, 6 toward the tableware stored in the tableware baskets 7, 8. In this case, the washing water is heated by the heating operation of the heater 4 to increase the temperature. The temperature of the washing water is controlled to be 60 ° C. based on the temperature detected by the temperature sensor 19. Then, when a set time (for example, 15 minutes) has elapsed after the start of the washing operation, the control device 33 cuts off the power of the pump motor 12 to stop the operation of the washing pump 10 and turns off the heater 4. This ends the washing operation. Note that the set time for the washing operation may be changed in length according to the initial temperature of the washing water.
[0033]
After the end of the washing operation, the control device 33 sequentially executes the first drainage operation, the water supply / supply / drainage operation, and the second drainage operation with a predetermined stop period (for example, 10 seconds) interposed therebetween. In a series of drainage operation periods, a rotation speed change control of changing the rotation speed of the drainage pump 11 through the inverter circuit 13 is performed at the final stage (during the second drainage operation).
[0034]
Specifically, during the first drainage operation, the pump motor 12 is reversely rotated at 2000 rpm and the drainage pump 11 is operated for a predetermined time (for example, about 40 seconds), so that the washing water in the washing tank 2 is discharged outside the machine. Perform the operation of discharging. At the time of water supply and water supply / drainage operation, after a predetermined delay time (for example, 5 seconds) elapses after the water supply valve 21 is opened, the pump motor 12 is also inverted at 2000 rpm while keeping the water supply valve 21 open. By rotating and operating the drain pump 11 for a predetermined time (for example, 5 seconds), the operation of discharging the cleaning water in the cleaning tank 2 to the outside of the machine is performed (the opening operation time of the water supply valve 21 is 10 seconds). During the second drainage operation, which is the final stage of the drainage operation, the reverse rotation speed of the pump motor 12 is increased to 2500 rpm (rotation speed change control), and the drainage pump 11 is operated for a predetermined time (for example, 15 seconds) in this state. An operation of discharging the washing water in the washing tank 2 to the outside of the machine.
[0035]
When the cleaning process is completed as described above, two rinsing processes are sequentially performed. In each rinsing step, after the water supply operation is performed, the rinsing operation, the first drainage operation, the water supply and supply / drainage operation, and the second drainage operation are sequentially performed with a predetermined stop period interposed therebetween. In this case, the water supply operation, the first drainage operation, the water supply and supply / drainage operation, and the second drainage operation are performed in the same manner as in the washing step. In the above-mentioned rinsing operation, the pump motor 12 is normally rotated at 3000 rpm through the inverter circuit 13 to operate the cleaning pump for a predetermined time (for example, one minute).
[0036]
After the two rinsing steps are performed as described above, the heating rinsing step is performed.
In the heating and rinsing process, first, a water supply operation is performed in which the water supply valve 21 is opened to supply tap water as cleaning water into the cleaning tank 2, and then the heater 4 is energized to heat the cleaning water. The cleaning pump 10 is operated by rotating the pump motor 12 forward at 3000 rpm. In accordance with the heating of the washing water, the tableware is efficiently rinsed and the tableware is warmed to improve the drying efficiency in the subsequent drying process.
[0037]
In this case, when the temperature sensor 19 detects that the temperature of the washing water has risen to, for example, 70 ° C., the controller 33 turns off the pump motor 12 to stop the operation of the washing pump 10 and the heater 4 , Thereby ending the heating and rinsing operation. Incidentally, the end time of the heating and rinsing operation can be controlled by time control. In the drainage operation performed thereafter, the pump motor 12 is reversely rotated at 2500 rpm and the drainage pump 11 is operated for a predetermined time (for example, about 40 seconds) to discharge the washing water in the washing tank 2 to the outside of the machine. I do.
[0038]
In the drying process performed after the heating and rinsing process as described above, the control device 33 continuously operates the fan motor 27 of the blower 23 and blows the air into the cleaning tank 2 while the heater 4 is periodically intermittently operated. Then, the drying operation of drying the dishes is performed. Such a drying process is performed for about 20 minutes, and when the drying process is finally completed, the display unit 32 and the buzzer 35 notify that the operation has been completed.
[0039]
According to the first embodiment, the following effects can be obtained.
According to the configuration of the present embodiment, it is possible to arbitrarily change the rotation speed of the drain pump 11 during the drain operation through the inverter circuit 13. More specifically, in the present embodiment, the rotation speed of the drain pump 11 is controlled to 2000 rpm during the first drainage operation in the cleaning step and the two rinsing steps, and during the supply / drainage operation. The rotation speed of the drain pump 11 is controlled to 2500 rpm during the second drain operation in the rinsing step and during the drain operation in the heating rinsing step, thereby increasing the drain capacity in the final drain operation in each step. The cleaning water can be reliably discharged out of the machine. Of course, when it is required to reduce the noise during the drain operation, the request can be dealt with by controlling the rotation speed of the drain pump 11 to decrease, and the noise during the drain operation can be increased. When it is required to reduce the required drainage time in an allowed state, the demand can be met by performing control to further increase the rotation speed of the drainage pump 11 to increase its drainage capacity.
[0040]
In the present embodiment, the cleaning pump 10 for performing the washing operation and the rinsing operation in each process and the drain pump 11 for performing the draining operation in each process are operated at different rotation speeds. . As a result, the performances of the cleaning pump 10 and the drainage pump 11 can be easily set to optimal conditions, respectively, so that the cleaning performance during the washing operation or the rinsing operation can be prevented from becoming insufficient. Thus, the time required for cleaning can be reduced. In this case, the pump motor 12 for operating the cleaning pump 10 is constituted by a DC brushless motor and is controlled at a variable speed via the inverter circuit 13, so that the rotation speed of the pump motor 12 and, consequently, the cleaning pump 10 And the ability of the drain pump 11 can be controlled very easily, and the washing operation and the heating rinsing operation are executed in a state where the temperature of the washing water is increased by energizing the heater 4, so that washing of dishes and the like is performed. The efficiency and the rinsing efficiency are improved. Of course, there is no need to consider the difference in the frequency of the commercial AC power supply, which is convenient for product development.
[0041]
In the present embodiment, the cleaning pump 10 and the drainage pump 11 are configured to include impellers 10b and 11b, respectively, which are rotationally driven by the same pump motor 12 that is controlled at a variable speed. After the cleaning pump 10 functions in the forward rotation and the drainage pump 11 functions in the reverse rotation, the pump motor 12 is rotated in the forward rotation direction (that is, when the cleaning pump 10 functions). The rotation speed is controlled so as to be different from that during rotation (that is, when the drain pump 11 functions). For this reason, the rotation speed and the size of each of the impellers 10 and 11b can be set to the optimum rotation speeds and shapes in consideration of the frequency of use of the forward and reverse rotations of the pump motor 12, and the like. Thus, the pump operation efficiency can be improved.
[0042]
Further, according to the above-described configuration, it is only necessary to provide one pump motor 12 and the entire configuration can be simplified, and the number of rotations of the pump motor 12 during forward rotation and reverse rotation is reduced. Since the capacity of the washing pump 10 and the drainage pump 11 can be easily changed only by changing each of them, it becomes extremely useful in designing and manufacturing a dishwasher.
[0043]
Further, in general, when the cleaning pump 10 and the drainage pump 11 are operated by the same motor at the same rotation speed, the drainage pump 11 is operated with an unnecessarily large capacity, and the operating noise is increased. However, according to the above configuration, such a disadvantage can be effectively solved. In addition, when the cleaning pump 10 and the drainage pump 11 are operated at the same rotation speed as described above, when the pump motor 12 rotates in the reverse direction (when the drainage pump 11 functions), the impeller 10b on the cleaning pump 10 side idles. As a result, a noise increase phenomenon occurs due to the entrainment of air on the cleaning pump 10 side. In the present embodiment, however, the rotation speed of the pump motor 12 at the time of reverse rotation is relatively small. It is possible to suppress an excessive noise increase phenomenon, and from this aspect, it is possible to reduce the operation noise. On the other hand, at the time of forward rotation of the pump motor 12 (when the cleaning pump 10 functions), the impeller 11b on the drain pump 11 side is rotated in the cleaning water and acts as rotation resistance. However, if the pump motor 12 is reversely rotated at a relatively high rotation speed, the impeller 11b can be downsized. Can be eliminated.
[0044]
In the present embodiment, at the final stage of a series of drainage operations, that is, at the time of the second drainage operation, after the drainage pump 11 is stopped for a predetermined time (10 seconds), the drainage pump 11 is rotated at a higher rotation speed (2500 rpm) than usual. There is also a feature in the configuration for performing the rotation speed change control of operating for a predetermined time (15 seconds). According to this configuration, dust and the like in the washing water settle on the bottom of the washing tank 2 during a period when the drain pump 11 is stopped for a predetermined time, and thereafter, the drain pump 11 rotates at a higher rotation speed than usual. As a result, the dust that has settled as described above is discharged to the outside of the machine with a vigor, and the possibility that the dust is left in the cleaning tank 2 is reduced.
[0045]
In this case, the start time of the rotation speed change control as described above is substantially determined based on the elapsed time from the start time of the first drainage operation. Can be easily performed by a control program set in the control device 33. The control device 33 may be configured to determine the start time of the rotation speed change control based on the water level detected by the water level switch 20. According to this configuration, the start time of the rotation speed change control is determined by the cleaning tank 2. It can be controlled accurately according to the water level inside.
[0046]
(Second embodiment)
FIG. 6 shows a second embodiment of the present invention, and only the portions different from the first embodiment will be described below.
In the second embodiment, as the dishwashing course executed by the control device 33, two types of the standard course shown in FIG. 1 and the silent course as shown in FIG. 6 are set (FIG. 6). Does not accurately reflect the time required for each step, as in FIG. 1). Such a dishwashing course selection operation is performed by the switch input unit 31 of the operation panel 30, but the following course selection operation may be automatically performed. That is, for example, a measuring means for measuring the noise level (background noise level) around the dishwasher is provided, and the control device 33 selects the silent course when the noise level measured by the measuring means is lower than the set level. In other cases, the standard course is selected. Alternatively, after the control device 33 has a built-in clock function, for example, a quiet time course is selected in the time zone from 23:00 to 7:00 based on the time information obtained by the clock function, The time zone is configured to perform an operation of selecting a standard course.
[0047]
The contents of the silent course shown in FIG. 6 will be described below. Also in this silent course, when the operation is started, first, the washing process is executed in the same manner as the standard course. In the washing operation performed after the completion of the water supply operation in the washing process, the heater 4 is energized to perform a heating operation, and the pump motor 12 is rotated forward through the inverter circuit 13 to operate the washing pump 10. At this time, the rotation speed of the pump motor 12 is controlled to be lower than that of the standard course, for example, 2200 rpm.
[0048]
When the cleaning pump 10 is operated in this manner, the cleaning water in the cleaning tank 2 is discharged from the ejection holes of the cleaning arms 5 and 6 toward the tableware stored in the tableware baskets 7 and 8, The temperature of the washing water is controlled by the heater 4 and the temperature sensor 19 so as to be 60 ° C. Then, when a set time (for example, 25 minutes longer than in the case of the standard course) has elapsed after the start of the washing operation, the control device 33 cuts off the power of the pump motor 12 to stop the operation of the washing pump 10 and turns off the heater 4. This terminates the washing operation.
[0049]
After the end of the washing operation, the control device 33 sequentially executes the first drainage operation, the water supply / supply / drainage operation, and the second drainage operation with a predetermined stop period (for example, 10 seconds) interposed therebetween. In this case, the first drainage operation, the water supply and the water supply / drainage operation are performed in the same manner as in the standard course, but during the second drainage operation in which the rotation speed change control is performed, the rotation speed of the pump motor 12 is reduced to 1800 rpm through the inverter circuit 13. The drainage pump 11 is operated for a predetermined time (for example, 30 seconds longer than in the case of the standard course) by rotating the drainage pump 11 in a reverse direction in such a state.
[0050]
When the cleaning process is completed as described above, two rinsing processes are sequentially performed. In each rinsing step, after the water supply operation is performed, the rinsing operation, the first drainage operation, the water supply and supply / drainage operation, and the second drainage operation are sequentially performed with a predetermined stop period interposed therebetween. In this case, the water supply operation, the first drainage operation, the water supply and supply / drainage operation, and the second drainage operation are performed in the same manner as in the washing step. In the above-mentioned rinsing operation, the pump motor 12 is normally rotated at 2200 rpm, which is lower than the standard course (3000 rpm), through the inverter circuit 13 to operate the washing pump for a predetermined time (for example, two minutes longer than the standard course). It is.
[0051]
After the two rinsing steps are performed as described above, the heating rinsing step is performed.
In this heating and rinsing process, first, the water supply valve 21 is opened to perform a water supply operation, and then the heater 4 is energized to heat the washing water while the pump motor 12 is set to 2200 rpm lower than the case of the standard course (3000 rpm). To rotate the cleaning pump 10 forward. In this case, the washing water is heated by the heating operation of the heater 4 to increase the temperature. The temperature of the washing water is controlled to be 60 ° C. based on the temperature detected by the temperature sensor 19. Then, when a set time (for example, 25 minutes) elapses after the start of the heating and rinsing operation, the control device 33 turns off the pump motor 12 to stop the operation of the cleaning pump 10 and turns off the heater 4. This terminates the heating and rinsing operation. At the time of the drainage operation to be performed thereafter, after the pump motor 12 is kept in reverse rotation at 2000 rpm for a predetermined time (for example, 30 seconds), rotation speed change control is performed to reduce the reverse rotation speed of the pump motor 12 to 1800 rpm. Then, when a predetermined time (for example, about 30 seconds) elapses thereafter, the pump motor 12 is turned off, thereby terminating the drainage operation. After the heating and rinsing step is completed in this way, a drying step similar to the standard course is performed.
[0052]
According to the above-described second embodiment, a noiseless course which is a dishwashing course in which noise during washing and rinsing operations and noise during drainage operations are suppressed, or the time required for washing and rinsing while allowing the noise and the time required for drainage Any of the standard courses, which are dishwashing courses in which the time has been shortened, can be selectively executed, thereby enabling the dishwasher to be multifunctional. In the case of the silent course as in this embodiment, a noise reduction effect of about 5 dB (A) was obtained as compared with the standard course.
[0053]
Also, when the silent course is selected, control is performed through the inverter circuit 13 so that the number of revolutions of the cleaning pump 10 is reduced below the number of revolutions in the standard course. The number of rotations of the drain pump 11 at the time of performing the drainage operation in the final stage (the second drainage operation in the washing step and the rinsing step and the drainage operation in the heating and rinsing step) also decreases to 1800 rpm in conjunction with the rotation number of 10. This is effective in suppressing noise. In addition, when the rotation speed of the drainage pump 11 is reduced as described above, there is an advantage that noise when a so-called air dust state occurs at the end of the drainage operation can be suppressed.
[0054]
In the present embodiment, when the control for reducing the rotation speed of the drainage pump 11 through the inverter circuit 13 is performed as described above, the control for extending the operation time of the drainage pump 11 is performed at the same time. In addition, the drainage operation time is extended by an amount corresponding to the decrease in the drainage capacity in accordance with the decrease in the rotation speed of the drainage pump 11, and there is no possibility that the drainage becomes insufficient.
[0055]
Further, if a measuring means for measuring the noise level around the dishwasher is provided, and the selecting operation of the dishwashing course is automatically performed based on the noise level measured by the measuring means, the surrounding noise may be reduced. When the (background noise) is low, that is, when the operating noise of the washing pump 10 and the drain pump 11 is relatively loud, the rotation speed of the pump is automatically reduced to reduce the operating noise. Above is beneficial. In addition, if the control device 33 is configured to have a built-in clock function, and the automatic selection operation of the dishwashing course is performed based on the time information obtained by the clock function, the driving noise may be annoying. The control to change the rotation speed of the washing pump 10 and the drainage pump 11 is automatically performed in a time period when the operation noise does not occur (for example, from 7:00 to 23:00) and a time period when the operation noise is harsh (for example, from 23:00 to 7:00). Therefore, it is possible to omit the troublesome operation of changing the number of rotations one by one on the user side.
[0056]
(Third embodiment)
FIG. 7 shows a third embodiment of the present invention. Hereinafter, only a portion different from the first embodiment will be described.
In the third embodiment, as shown in FIG. 7, the control device 33 supplies power to the heater 4 to start the drying process at the time before the drainage operation performed in the final stage of the heating and rinsing process is completed. It has become. Specifically, after the drainage operation in which the drainage pump 11 is rotated at 2500 rpm is started at the final stage of the heating and rinsing step, for example, when 20 seconds have elapsed, the heater 4 is energized for the drying step. The energization start timing is based on the timing at which the heater 4 is exposed from the washing water in accordance with the progress of the drainage operation. Therefore, a configuration in which the energization start timing is determined by the water level detected by the water level switch 20 is adopted. Is also possible.
[0057]
The control device 33 continues the state in which the heater 4 is energized in the operation state of the drain pump 11 for, for example, 20 seconds, and then temporarily cuts off the power of the heater 4 for, for example, 15 seconds. The operation of the pump 11 is stopped and the power supply to the heater 4 is restarted. In this case, during the period when the heater 4 as another load is simultaneously energized in the operation state of the drain pump 11, control is performed to reduce the rotation speed of the drain pump 11 to, for example, 2000 rpm, and the heater 4 is temporarily turned off. During the period during which power is supplied, control is performed to return the rotation speed to 2500 rpm. When the drain pump 11 is operated at 2000 rpm, the power consumption associated therewith is reduced from about 280 W to about 200 W.
[0058]
As a result, according to the present embodiment, the peak value of the power consumption is suppressed, and the capacity of the drain pump 11 is maximized in cooperation with the energized state of the heater 4 within the limited current capacity. Can be demonstrated to the maximum extent. Further, since the heating rinsing step and the drying step are performed in an overlapping state, the required time can be shortened accordingly.
[0059]
(Other embodiments)
Note that the present invention is not limited to the above-described embodiment, and the following modifications or extensions are possible.
Although the inverter circuit 13 which is a variable frequency power supply is used as the cleaning pump driving unit for performing the variable speed operation of the cleaning pump 10 and the drain pump driving unit for performing the variable speed operation of the drain pump 11, the phase control is performed. It is also possible to employ a system or a device for performing thinning control of the power supply waveform. Although the washing pump 10 and the drainage pump 11 are rotated by the same pump motor 12 in a one-motor system, each of the pumps 10 and 11 may be operated by a dedicated pump motor. The number of rotations of the washing pump 10 during the washing operation and the number of rotations of the drainage pump 11 during the draining operation are not limited to the numerical values as in the above embodiments as long as the object of the present invention can be achieved. Of course. In the second embodiment, two types of dishwashing courses, a standard course and a silent course, are set, but the required time can be further shortened by further increasing the number of rotations of the washing pump 10 and the drainage pump 11 from the standard course. A dishwashing course can be set up.
[0060]
【The invention's effect】
As is clear from the above description, according to the present invention, the following effects can be obtained.
According to the dishwasher according to claim 1, the rotation speed of the drainage pump is changed during the drainage operation.To control the number of revolutionsWith this configuration, it is possible to reduce drainage noise and drainage required time as required.In addition, since the content of the above-described rotation speed change control is changed according to the type of the dishwashing course to be executed, it is possible to achieve multifunctional dishwashers.
[0066]
Claim2According to the dishwasher described above, in addition to the rotation speed of the drainage pump, the rotation speed of the cleaning pump for performing the washing operation and the rinsing operation can be arbitrarily changed through the cleaning pump driving means. And the capacity of the drainage pump can be easily set to the optimum state, respectively, so that the noise reduction during drainage operation or the time required for drainage can be reduced, and at the same time the noise reduction during washing operation and rinsing operation and the time required for cleaning can be reduced. Shortening can also be realized at the same time.
[0068]
Claim3According to the dishwasher described above, at least the rotation speed of the drainage pump is controlled through the drainage pump driving unit based on the time information obtained by the clock function incorporated in the control unit, so that the operating noise does not become annoying. It is possible to automatically perform the control to change the rotation speed of the drain pump between the belt and the time when the operation noise is annoying, eliminating the troublesome operation of changing the rotation speed of the drain pump one by one on the user side become able to.
[0070]
Claim4According to the dishwasher described, during the period when the drain pump is in operation and the other loads are simultaneously energized, the control to reduce the rotation speed of the drain pump is performed, so that the peak value of power consumption is reduced. In addition, the capacity of the drain pump can be maximized in coordination with the energized state of other loads within the limited current capacity.
[Brief description of the drawings]
FIG. 1 is a timing chart for explaining a first embodiment of the present invention, showing the contents of a process for washing dishes together with a temperature change characteristic of washing water and a rotation speed of a pump motor.
FIG. 2 is a longitudinal side view.
FIG. 3 is an external perspective view.
FIG. 4 is a longitudinal sectional side view showing a pump structure.
FIG. 5 is a functional block diagram schematically showing an electrical configuration.
FIG. 6 is a view corresponding to FIG. 1, showing a second embodiment of the present invention;
FIG. 7 is a timing chart of a main part showing a third embodiment of the present invention.
[Explanation of symbols]
2 is a washing tank, 4 is a heater, 5 and 6 are washing arms, 7 and 8 are tableware baskets, 10 is a washing pump, 10b is an impeller, 11 is a drainage pump, 11b is an impeller, 12 is a pump motor, and 13 is an inverter circuit. (Wash pump drive means, drain pump drive means), 19 is a temperature sensor, 20 is a water level switch (water level detection means), 21 is a water supply valve, 30 is an operation panel, 31 is a switch input section, 32 is a display section, and 33 is a display section. 3 shows a control device (control means).

Claims (4)

A dishwasher in which a standard course for performing a washing step, a rinsing step, a heating rinsing step, and a drying step in this order, and a silent course for executing the same step as the standard course while suppressing operation noise are set as a dishwashing course. At
A washing tank for storing tableware,
A cleaning pump for discharging the cleaning water supplied into the cleaning tank toward the stored tableware,
A drainage pump for discharging the washing water in the washing tank outside the machine,
Control means for controlling a washing operation and a rinsing operation by the washing pump and a drainage operation by the drainage pump,
Drain pump driving means for driving the drain pump at a variable speed,
The control means performs a rotation speed change control for changing the rotation speed of the drainage pump through the drainage pump driving means during the drainage operation, and performs the content of the rotation speed change control according to the type of dishwashing course to be executed. A dishwasher characterized by being changed. A cleaning pump driving means for driving the cleaning pump at a variable speed,
When the control means changes the rotation speed of the cleaning pump through the cleaning pump driving means, the control means changes the rotation speed of the drain pump through the drain pump driving means in conjunction with the rotation speed of the cleaning pump. The dishwasher according to claim 1, wherein:
A dishwasher characterized by that: The control means has a built-in clock function, and at the time of performing the drain operation, controls at least the rotation speed of the drain pump through the drain pump driving means based on the time information obtained by the clock function. The dishwasher according to claim 1 or 2, wherein 4. The control device according to claim 1 , wherein the control unit performs control to reduce the rotation speed of the drain pump during a period in which another load is simultaneously energized in the operation state of the drain pump . 5. Dishwasher.

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