JP4769831B2 - Dishwasher - Google Patents

Description

  The present invention relates to a technique for detecting that bubbles are generated in a washing tank of a dishwasher.

  The dishwasher stores cleaning water in a cleaning tank, and cleans the dishes by spraying the cleaning water in the cleaning tank toward the tableware by a cleaning pump. Usually, a detergent that is difficult to foam (hereinafter referred to as a detergent for a washing machine) is used as a detergent for the dishwasher. However, if the user mistakenly introduces a detergent that easily foams (hereinafter referred to as a general detergent) such as a kitchen detergent, a large amount of foam is generated in the washing tub during washing. When a large amount of foam is generated in the washing tub, the foam may flow into a water channel or an air passage leading to the washing tub, and the dishwasher may malfunction. For example, when a water level chamber (space for detecting the water level) communicating with the washing tank is formed, bubbles may flow into the water level chamber and the dishwasher may malfunction.

  Patent Document 1 discloses a dishwasher that detects the generation of bubbles in a washing tank. The dishwasher performs an injection stroke in which the cleaning water is injected into the cleaning tank by the cleaning pump in a state where the cleaning water is accumulated in the cleaning tank up to the reference water level. Here, when washing machine detergent is put in the dishwasher, the washing water adheres to the tableware in the washing tank and the wall surface of the washing tank (hereinafter referred to as tableware). The water level drops. In addition, when a general detergent is accidentally put into the dishwasher, in addition to the washing water adhering to the dishes, a large amount of foam is generated in the washing tank. Decrease greatly. After performing the previous injection stroke, the dishwasher supplies water to the washing tub for a certain period of time in order to detect the occurrence of bubbles (water supply stroke). Then, after the water supply stroke, it is detected whether or not the water level in the cleaning tank has reached the reference water level. If the amount of decrease in the water level in the injection stroke is small (that is, if a large amount of bubbles is not generated in the cleaning tank), the water level in the cleaning tank reaches the reference water level by the water supply stroke. If the amount of decrease in the water level in the injection stroke is large (that is, if a large amount of bubbles is generated in the cleaning tank), the water level in the cleaning tank does not reach the reference water level even if the water supply stroke is executed. Therefore, whether or not a large amount of bubbles is generated in the cleaning tank can be detected based on whether or not the water level in the cleaning tank after the water supply stroke has reached the reference water level.

JP 2001-327454 A

  As described above, in the ejection stroke of the dishwasher of Patent Document 1, although there is a difference in the amount of decrease in the water level, the water level in the cleaning tank decreases regardless of the type of detergent. The amount of decrease in the water level when the detergent for the washing machine is charged varies depending on the amount of tableware stored in the cleaning tank (that is, the amount of cleaning water adhering to the tableware). In addition, there is an error in the amount of water supplied in the water supply stroke after the injection stroke. Therefore, due to these variation factors, the water level in the cleaning tank after the water supply stroke varies. If the difference in water level drop due to the presence or absence of bubbles (ie, the difference in water level drop between using a general detergent and a washing machine detergent) is less than the amount of water level fluctuation, It cannot be detected whether or not bubbles are generated. That is, in the dishwasher of Patent Document 1, it is necessary to execute the injection stroke for a long time (for example, 10 minutes) in order to increase the difference in the amount of decrease in the water level depending on the presence or absence of bubbles to easily determine the generation of bubbles. there were. That is, the dishwasher of Patent Document 1 requires a long time to detect the generation of bubbles in the washing tank, and the bubbles may reach the drying fan or flow out of the exhaust port. It was.

  This invention is made | formed in view of the situation mentioned above, and it aims at providing the dishwasher which can detect generation | occurrence | production of the bubble in a washing tank in a short time.

The tableware washing machine of the present invention includes a washing tank, a washing nozzle that injects washing water into the washing tank, a washing pump that sucks the washing water in the washing tank and sends it to the washing nozzle, and sends air into the washing tank A fan, a water level chamber communicating with the cleaning tank, a water level detecting means for detecting the water level in the water level chamber, and a control device are provided. The control device executes a bubble detection process including an injection stroke, a blowing process, and a water level lowering speed determination process. In the injection process, after supplying water to the cleaning tank, the cleaning pump is operated to inject cleaning water from the cleaning nozzle into the cleaning tank. In the blowing process, after the injection stroke, the fan is operated to send air into the cleaning tank. The water level lowering speed determination process determines whether or not the water level in the water level chamber decreases at a speed equal to or higher than the reference speed after the blowing process.
In this dishwasher, the water level chamber communicates with the washing tank. Therefore, when cleaning water is stored in the cleaning tank by water supply, the cleaning water is stored in the water level chamber to the same water level as the cleaning tank. A control apparatus performs an injection stroke after water supply. In the spray stroke, a large amount of foam is generated in the cleaning tank when general detergent is put in the cleaning tank, and almost no foam is generated in the cleaning tank when detergent for the washing machine is put in the cleaning tank. Does not occur. Next, the control device operates the fan to send air into the cleaning tank (air blowing process). Thereby, the pressure of the air in the cleaning tank increases. Then, the surface of the cleaning water in the cleaning tank is pushed down by the pressure of the air in the cleaning tank, and the water level in the water level chamber rises. When the blowing process is finished (that is, when the fan is stopped), the pressure of the air in the cleaning tank decreases, so that the water level in the cleaning tank rises and the water level in the water level chamber decreases. At this time, if bubbles are not generated in the cleaning tank, the water levels in the cleaning tank and the water level chamber are restored immediately after the completion of the blowing process. That is, the water level lowering rate in the water level chamber is fast. On the other hand, when a large amount of foam is generated in the cleaning tank, the foam becomes resistance and the rising speed of the water level in the cleaning tank becomes slow. That is, the rate of lowering the water level in the water level chamber becomes slower. Therefore, the control device determines whether or not the water level in the water level chamber decreases at a speed equal to or higher than the reference speed after the blowing process (water level lowering speed determination process). Thereby, it can be determined whether or not bubbles are generated in the cleaning tank.
Thus, this dishwasher detects generation | occurrence | production of a bubble based on the fall rate of the water level of the water level chamber after a ventilation process. Therefore, it is possible to detect the presence or absence of bubbles without being affected by variations in the water level caused by errors in the amount of water supply or the amount of washing water adhering to the tableware. Therefore, it is not necessary to execute the injection stroke for a long time, and it is possible to detect the presence or absence of bubbles in a short time.

The dishwasher mentioned above can also be comprised using a means to detect whether the water level in a water level chamber has reached the reference water level as a water level detection means. In this case, it is preferable that the control device executes the bubble detection process as follows. That is, a water level determination process for determining whether or not the water level in the water level chamber has reached the reference water level is performed after the injection stroke and before the blowing process. The blowing process is executed when it is determined in the water level determination process that the water level in the water level chamber has not reached the reference water level. In the air blowing process, it is determined whether or not the water level in the water level chamber reaches the reference water level. The water level lowering speed determination process is executed when it is determined by the blowing process that the water level in the water level chamber has reached the reference water level. In the water level lowering speed determination process, it is determined whether or not the water level in the water level chamber falls below the reference water level within a predetermined time from the end of the blowing process.
According to such a configuration, the blowing process is started in a state where the water level in the water level chamber is lower than the reference water level. Further, when the water level in the water level chamber reaches the reference water level during the blowing process, the water level lowering speed determination process is executed. Therefore, when the air blowing process is finished in a state where the water level in the water level chamber has reached the reference water level, the water level in the water level chamber that is equal to or higher than the reference water level is lowered to a water level lower than the reference water level. At this time, if bubbles are generated in the cleaning tank, the rate of decrease of the water level in the water level chamber is slowed down, so that the time required for the water level in the water level chamber to fall below the reference water level becomes long. Therefore, it is possible to detect the generation of bubbles in the cleaning tank by determining whether or not the water level in the water level chamber falls below the reference water level within a certain time from the end of the blowing process. That is, determining whether or not the water level in the water level chamber falls below the reference water level within a certain time is equivalent to determining whether or not the water level in the water level chamber is decreased at a speed equal to or higher than the reference speed.
As described above, according to such a configuration, the generation of bubbles is detected using simple water level detection means (water level detection means for detecting whether or not the water level in the water level chamber has reached the reference water level). be able to.

When using a water level detecting means for detecting whether or not the reference water level has been reached, it is preferable to end the blowing process when the control device determines that the water level in the water level chamber has reached the reference water level during the blowing process. .
According to such a configuration, regardless of the water level in the water level chamber before the start of the blowing process, the water level in the water level chamber at the end of the blowing process becomes substantially equal to the reference water level. Therefore, by determining whether or not the water level in the water level chamber falls below the reference water level within a predetermined time from the end of the blowing process, it is possible to accurately determine the rate of decrease in the water level in the water level chamber. That is, the generation of bubbles in the cleaning tank can be detected more accurately.

When using a water level detection means for detecting whether or not the reference water level has been reached, it is preferable that the control device starts the injection stroke with the water level in the cleaning tank adjusted to the reference water level.
According to such a structure, when the water level of a washing tank falls in an injection stroke, the water level in a water level chamber becomes a water level slightly lower than a reference | standard water level. Therefore, the water level in the water level chamber easily reaches the reference water level during the blowing process.

When using a water level detecting means for detecting whether or not the reference water level has been reached, it is preferable that the control device repeatedly executes the bubble detection process. And it is preferable to calculate a bubble determination index value based on the determination result of the water level determination process in each bubble detection process, a ventilation process, and a water level fall speed determination process.
Thus, the bubble detection accuracy can be increased by repeatedly executing the bubble detection process and calculating the bubble determination index value based on the determination result in each bubble detection process.

When the pump is operated in a state where a general detergent is introduced, the amount of new bubbles generated increases as more bubbles are present in the cleaning tank. That is, in a state where there are almost no bubbles, bubbles are generated when the cleaning water sprayed from the cleaning nozzle collides with a wall surface or a water surface in the cleaning tank. On the other hand, in the state where the foam is present, the foam is generated in the washing pump when the foam is caught in the washing pump, and the amount of foam generated per unit time (hereinafter referred to as the foam generation speed). ) Will increase. That is, when the bubble detection process is repeatedly executed, the number of bubbles in the cleaning tank increases and the generation speed of bubbles increases as the injection stroke is executed later.
Therefore, when the bubble detection process is repeatedly executed, it is preferable that the control device shortens the execution time as the injection stroke is executed later.
As described above, in the injection stroke to be executed later, since the generation speed of bubbles when the general detergent is charged is high, a sufficient amount of bubbles is generated even if the execution time is short. Therefore, even if the execution time of the injection stroke is short, the generation of bubbles can be detected. Moreover, according to such a structure, generation | occurrence | production of a bubble can be detected in a shorter time.

  According to the dishwasher of this invention, generation | occurrence | production of the bubble in a washing tank is detectable in a short time.

(Example)
An embodiment of the dishwasher of the present invention will be described with reference to the drawings. FIG. 1: has shown schematic sectional drawing of the dishwasher 10 of a present Example.
The dishwasher 10 includes a case 12 and a cleaning tank 14 accommodated in the case 12. A door 15 is integrally attached to the front side of the cleaning tank 14 (left side in FIG. 1). By pulling out the door 15, the cleaning tank 14 is pulled out from the case 12, and the tableware can be placed in the cleaning tank 14. As shown in the drawing, in the state where the cleaning tank 14 is housed in the case 12, the upper part of the cleaning tank 14 is closed by the lid 56.

  An operation panel 16 is provided on the upper portion of the door 15. A control device 60 is installed near the operation panel 16. The control device 60 controls the operation of each part of the dishwasher 10.

  The door 15 has an exhaust passage 18 that communicates the front surface of the door 15 and the cleaning tank 14. An exhaust damper 19 is installed in the middle of the exhaust passage 18.

  The door 15 is provided with a detergent storage tank 62. Detergent is stored in the detergent storage tank 62. The detergent storage tank 62 is provided with an inlet (not shown) for replenishing detergent from the front surface of the door 15. The detergent is replenished to the detergent storage tank 62 by the user. The detergent storage tank 62 communicates with the cleaning tank 14 by a detergent supply path 64. A detergent supply valve 66 is installed in the middle of the detergent supply path 64. When the detergent supply valve 66 is opened, the detergent in the detergent storage tank 62 is supplied into the cleaning tank 14 through the detergent supply path 64. The detergent supply valve 66 is controlled by the control device 60.

A dish basket 61 and a cleaning nozzle 22 are installed in the cleaning tank 14.
Tableware can be placed in the tableware basket 61.
The cleaning nozzle 22 injects cleaning water supplied from an impeller housing chamber 31 described later into the cleaning tank 14 from a plurality of injection ports. As a result, washing water is applied to the tableware placed in the tableware basket 61, and the tableware is washed.
A recess 29 is formed on the bottom surface of the cleaning tank 14. The upper opening of the recess 29 is covered with the leftover filter 17. The leftover filter 17 is formed in a mesh shape.

A water level chamber 45 is installed between the cleaning tank 14 and the door 15. The water level chamber 45 communicates with the cleaning tank 14 through the communication passage 50. One end of the communication path 50 opens at the bottom of the cleaning tank 14 (the wall surface of the recess 29), and the other end opens at the bottom of the water level chamber 45. The upper part of the water level chamber 45 is open to the atmosphere at a position not shown. Therefore, when the cleaning water is stored in the cleaning tank 14, the cleaning water is stored in the water level chamber 45 up to substantially the same water level as the cleaning tank 14.
In the water level chamber 45, a water level detection device 46 for detecting the water level in the water level chamber 45 is installed. The water level detection device 46 includes a float 47, a shaft 48, and a water level detection switch 49 (for example, a reed switch). The shaft 48 is inserted into a hole formed in the upper portion of the water level chamber 45 and is slidable up and down. The float 47 is fixed to the lower end of the shaft 48. The float 47 floats in the water. Accordingly, when the cleaning water accumulates in the water level chamber 45, the float 47 and the shaft 48 move up and down according to the level of the cleaning water. The water level detection switch 49 is installed at a position facing the upper end of the shaft 48. When the water level in the water level chamber 45 rises to a certain level, the shaft 48 contacts the water level detection switch 49. As a result, the water level detection switch 49 is turned on. That is, the water level detection device 46 is turned on. Hereinafter, the water level at which the water level detection device 46 is turned on is referred to as a reference water level. The on / off state of the water level detection device 46 is read by the control device 60.

  One end of a water supply pipe 43 is connected to the back surface of the cleaning tank 14. The other end of the water supply pipe 43 is drawn out of the case 12 and is connected to the water supply source 40. A water supply valve 44 is provided in the middle of the water supply pipe 43. When the water supply valve 44 is opened, tap water is introduced into the cleaning tank 14. The water supply valve 44 is controlled by the control device 60.

  A water channel 32 is formed below the cleaning tank 14. One end of the water channel 32 opens to the wall surface of the recess 29, and the other end opens to the impeller accommodating chamber 31. An impeller 27 for the cleaning pump 28 is installed in the impeller accommodating chamber 31. A cleaning nozzle 22 is connected to the upper portion of the impeller accommodating chamber 31. A drain pipe 36 is connected to the lower part of the impeller accommodating chamber 31. The cleaning pump 28 rotates the impeller 27 by a built-in electric motor. The cleaning pump 28 can rotate the impeller 27 in one direction or in the reverse direction. When the cleaning pump 28 rotates the impeller 27 in the one direction, cleaning water is sent from the water channel 32 to the cleaning nozzle 22, and when the cleaning pump 28 rotates the impeller 27 in the reverse direction, the water channel 32 passes to the drain pipe 36. Wash water is sent in (functions as a drain pump when rotating in the reverse direction). The cleaning pump 28 is controlled by the control device 60.

  One end of the drain pipe 36 is connected to the lower portion of the impeller accommodating chamber 31, and the other end is drawn out of the case 12 and connected to the drain section 34. When the cleaning pump 28 rotates the impeller 27 in the reverse direction, the cleaning water in the cleaning tank 14 is discharged to the drainage part 34 through the water channel 32 and the drain pipe 36. A bent portion 33 is formed in the drain pipe 36. In a state where the washing water is not discharged, water is accumulated in the bent portion 33. Therefore, in a state where the cleaning water is not discharged, the drain pipe 36 is blocked by the water accumulated in the bent portion 33, and air does not flow through the drain pipe 36.

  One end of an air vent pipe 37 is opened on the back surface of the cleaning tank 14. The other end of the air vent pipe 37 is connected to the middle of the drain pipe 36. The air vent pipe 37 prevents the water in the cleaning tank 14 from being discharged from the drain pipe 36 by using the drain pipe 36 as a siphon.

An air supply pipe 54 is connected to the back surface of the cleaning tank 14. A fan 52 is installed at the other end of the air supply pipe 54. When the fan 52 is operated, air is sent from the air supply pipe 54 into the cleaning tank 14.
A heater 30 is installed below the connection portion of the air supply pipe 54 in the cleaning tank 14. When the heater 30 is operated while the cleaning water is accumulated in the cleaning tank 14, the cleaning water is heated. When the heater 30 is operated in a state where no cleaning water is accumulated in the cleaning tank 14, the air in the cleaning tank 14 is heated.

  Next, the process which detects the foam which the dishwasher 10 performs at the time of the start of a washing | cleaning process is demonstrated. FIG. 2 is a flowchart showing processing executed by the control device 60. The control device 60 counts a count value C <b> 1 that indicates a possibility that bubbles are generated in the cleaning tank 14 while advancing each step of the flowchart of FIG. 2. And generation | occurrence | production of the bubble in the washing tank 14 is detected based on count value C1.

  In step S <b> 2, the control device 60 discharges the washing water remaining in the dishwasher 10. That is, the control device 60 rotates the impeller 27 of the cleaning pump 28 in the reverse direction. If cleaning water from the previous use remains in the recess 29 or the drain pipe 36, the remaining cleaning water is discharged in step S2. When the cleaning pump 28 is operated for a predetermined time, the control device 60 stops the cleaning pump 28.

In step S4, cleaning water and detergent are supplied into the cleaning tank. That is, the control device 60 opens the water supply valve 44 and opens the detergent supply valve 66. When the water supply valve 44 is opened, tap water (that is, cleaning water) is introduced into the cleaning tank 14 from the water supply pipe 43. When the detergent supply valve 66 is opened, the detergent is supplied from the detergent storage tank 62 into the cleaning tank 14. Therefore, water in which the cleaning water and the detergent are mixed (hereinafter simply referred to as cleaning water) accumulates in the cleaning tank 14. Further, since the water level chamber 45 communicates with the cleaning tank 14, when cleaning water accumulates in the cleaning tank 14, the cleaning water also accumulates in the water level chamber 45 to the same water level as the cleaning tank 14. In step S4, cleaning water is stored in the cleaning tank 14 until the water level detection device 46 is turned on. When the water level detection device 46 is turned on, the control device 60 closes the water supply valve 44 and the detergent supply valve 66. Therefore, at the end of step S4, the cleaning water is in the cleaning tank 14 up to the reference water level.
If the user accidentally replenishes the detergent storage tank 62 with the general detergent, the general detergent is put into the cleaning tank 14 in step S4.

  In step S5, the count value C1 is set to zero.

In step S6, the control device 60 operates the cleaning pump 28 (rotates the impeller 27 in the one direction). At the same time, the heater 30 is operated. When the cleaning pump 28 and the heater 30 are operated, the cleaning water accumulated in the cleaning tank 14 flows into the water channel 32 and is sent from the cleaning pump 28 to the cleaning nozzle 22. The cleaning water sent to the cleaning nozzle 22 is injected into the cleaning tank 14 from the injection port of the cleaning nozzle 22. This cleans the dishes. The first step S6 is executed for about 30 seconds.
During the execution of step S6, the water level in the cleaning tank 14 decreases. When the detergent for the washing machine is put in the washing tank 14, the water level in the washing tank 14 is lowered by the sprayed washing water adhering to the tableware or the like. The water level after execution of step S6 varies depending on the conditions during execution of step S6. For example, when a relatively large amount of cleaning water is stored in the cleaning tank 14 at the start of step S6 due to an error in the amount of water supplied in step S4 (that is, cleaning water is stored up to a level slightly higher than the reference water level). ), The water level after step S6 is relatively high. When a relatively large amount of tableware is stored in the cleaning tank 14, the amount of cleaning water attached to the tableware increases in step S6, so that the water level after execution of step S6 is relatively low. In addition, when the tableware is mistakenly placed upward, the water level in the cleaning tank 14 is lowered by storing the cleaning water in the tableware. Therefore, when the detergent for washing machine is thrown in, the water level in the washing tank 14 after the execution of step S6 may be lower than the reference water level or may have reached the reference water level. In addition, when a general detergent is added, in addition to the washing water adhering to the tableware or the like, the water level is also lowered by the generation of bubbles in the washing tank 14 (that is, the washing water is foamed). Since it becomes a liquid film, the water level in the cleaning tank 14 is lowered). In this case, the amount of decrease in the water level is greater than when the detergent for the washing machine is introduced. When the general detergent is put, the water level in the cleaning tank 14 after the execution of step S6 is lower than the reference water level.

In step S8, the control device 60 detects whether or not the water level detection device 46 is on. As described above, since the water level in the cleaning tank 14 is lower than the reference water level when the general detergent is introduced, in step S8, it is detected that the water level detection device 46 is off. On the other hand, when the detergent for the washing machine is inserted, the water level in the cleaning tank 14 may or may not reach the reference water level, and therefore the water level detection device 46 is turned on or off in step S8. Is detected.
That is, turning on the water level detection device 46 in step S8 indicates that bubbles are not generated in the cleaning tank 14. In this case (YES in step S8), control device 60 executes step S18 without executing steps S10 to S16.
On the other hand, turning off the water level detection device 46 in step S8 indicates that bubbles may be generated in the cleaning tank 14. In this case (NO in step S8), the control device 60 performs the processes after step S10 to further determine the presence or absence of bubbles in the cleaning tank 14.

In step S <b> 10, the control device 60 operates the fan 52. Then, air is fed into the cleaning tank 14 from the air supply pipe 54, and the pressure of the air in the cleaning tank 14 increases. The air sent into the cleaning tank 14 is released to the outside from the exhaust passage 18, but the fan 52 continues to send air into the cleaning tank 14, so that the high pressure state in the cleaning tank 14 is maintained. When the pressure of the air in the cleaning tank 14 rises, as shown in FIG. 3, the water level in the cleaning tank 14 is pushed down by the pressure of the air, and the water level in the water level chamber 45 rises. The control device 60 operates the fan 52 until the water level detection device 46 is turned on (that is, until the water level in the water level chamber 45 reaches the reference water level). However, when a very large amount of bubbles are present in the cleaning tank 14, the air supply pipe 54 is blocked by the bubbles, or the water level in the cleaning tank 14 before the fan 52 is activated is extremely high. Since it becomes low, the water level detection device 46 may not turn on. When the water level detection device 46 is not turned on, the control device 60 stops the fan 52 30 seconds after the fan 52 is operated.
When the water level detection device 46 is turned on in step S10 (that is, YES in step S10), the control device 60 executes step S12.
When the water level detection device 46 is not turned on in step S10 (that is, NO in step S10), the control device 60 executes step S16.

  When step S10 is completed (that is, when the fan 52 is stopped), the pressure of the air in the cleaning tank 14 returns to the original level, so that the water levels in the cleaning tank 14 and the water level chamber 45 return. That is, the water level in the cleaning tank 14 rises, the water level in the water level chamber 45 falls, and becomes below the reference water level. Therefore, when the water level detection device 46 is turned on in step S10, the water level detection device 46 is turned off again. At this time, if a large amount of bubbles is not generated in the washing tank 14, the water level returns to the original water level in a short time. Therefore, immediately after the fan 52 is stopped, the water level detection device 46 is turned off. On the other hand, when a large amount of bubbles are generated in the cleaning tank 14 and the water surface of the cleaning water is covered with bubbles, the bubbles become resistance, so it takes time for the water level to return to the original water level. That is, the water level in the washing tank 14 rises slowly, and the water level in the water level chamber 45 falls slowly. Therefore, it takes time until the water level detection device 46 is turned off after the fan 52 is stopped.

As shown in FIG. 2, when the water level detection device 46 is turned on in step S10, the control device 60 waits for about 10 seconds after completing step S10 (that is, after stopping the fan 52) (see FIG. 2). Step S12). Then, after waiting, it is determined in step S14 whether or not the water level detection device 46 is on.
If a large amount of bubbles is not generated in the cleaning tank 14, the water level in the water level chamber 45 becomes less than the reference water level during the 10-second standby. Therefore, in step S14, the water level detection device 46 is detected to be off. In this case (NO in step S14), control device 60 executes step S18.
On the other hand, when a large amount of bubbles is generated in the cleaning tank 14, the water level in the water level chamber 45 does not become lower than the reference water level even after waiting for 10 seconds. Therefore, the ON of the water level detection device 46 is detected in step S14. In this case (YES in step S14), control device 60 executes step S16.

As described above, if YES is determined in step S8 or NO in step S14, it can be determined that not many bubbles are generated in the cleaning tank 14. In addition, when it is determined NO in step S10 or YES in step S14, it can be determined that a large amount of bubbles is generated in the cleaning tank 14. Therefore, the generation of bubbles in the cleaning tank 14 can be detected based on these determination results.
However, the control device 60 continues to execute the following processing in order to further improve the detection accuracy of the generation of bubbles.

  As shown in FIG. 2, when it is determined NO in step S10 or YES in step S14, control device 60 adds “1” to count value C1 in step S16. The count value C1 is a value indicating the possibility that bubbles are generated in the cleaning tank 14, and the larger the count value C1, the higher the possibility that bubbles are generated in the cleaning tank 14. Since the count value C1 is set to “0” in step S5, the count value C1 is changed from “0” to “1” here.

In step S18, the control device 60 determines the count value C1. The determination of the count value C1 will be described in detail later.
In the first step S18, the control device 60 proceeds as shown by an arrow X in FIG. 2 and supplies water into the cleaning tank 14 in step S20. In step S20, water is supplied into the cleaning tank 14 until the water level detection device 46 is turned on (when the water level detection device 46 is already turned on, water is not supplied). And the process from step S6 is performed again.

  As described above, the control device 60 repeatedly executes the processes of steps S6 to S20. Accordingly, the count value C1 is changed based on the determination result at each time. That is, the higher the possibility that bubbles are generated in the cleaning tank 14, the count value C1 is changed to a larger value.

  As described above, the control device 60 determines the count value C1 in step S18. Hereinafter, the determination in step S18 will be described in detail.

  As described above, in the first step S18, the control device 60 executes the processing from step S6 again (arrow X in FIG. 2), regardless of the count value C1.

In the second step S18, the control device 60 determines whether the count value C1 is “0”, “1”, or “2”.
The count value C1 being “2” is a determination result indicating that bubbles are generated in the cleaning tank 14 in both the first process (that is, the processes in steps S6 to S14) and the second process. It means that it became. That is, the possibility that bubbles are generated in the cleaning tank 14 is extremely high. Therefore, when the count value C1 is “2”, the control device 60 executes the defoaming operation in step S24 (arrow Z in FIG. 2). The defoaming operation is an operation in which a drain operation for draining substantially all of the cleaning water in the cleaning tank 14 and a water supply operation for introducing new cleaning water into the cleaning tank 14 are repeated four times. Due to the defoaming operation, bubbles in the cleaning tank 14 disappear. When the defoaming operation is executed, the control device 60 ends the operation.
The count value C1 being “1” means that bubbles may or may not be generated in the cleaning tank 14. For example, when the amount of foam generated in the cleaning tank 14 is an amount just below the allowable range, different determination results may be obtained between the first process and the second process. Thus, when the count value C1 is “1”, the control device 60 executes the processing from step S6 again (arrow X in FIG. 2).
The count value C1 being “0” means that the determination result indicates that bubbles are not generated in the cleaning tank 14 in both the first process and the second process. That is, it means that there is an extremely high possibility that bubbles are not generated in the cleaning tank 14. Therefore, when the count value C1 is “0”, the control device 60 executes the cleaning operation of Step S22 (operation for continuously cleaning the dishes by operating the cleaning pump 28 and the heater 30) (Step S22). Arrow Y in FIG. After performing the washing operation, a rinsing operation and a drying operation are performed.

  In the third step S18, the control device 60 determines whether or not the count value C1 is “2”. When the count value C1 is “2”, the control device 60 executes the defoaming process in step S24 (arrow Z in FIG. 2). When the count value C1 is not “2” (that is, when the count value C1 is “1”), the control device 60 executes the processing from step S6 again (arrow X in FIG. 2).

  In the fourth step S18, the control device 60 determines whether or not the count value C1 is “2”. When the count value C1 is “2”, the control device 60 executes the defoaming process in step S24 (arrow Z in FIG. 2). When the count value C1 is not “2” (that is, when the count value C1 is “1”), the control device 60 performs the cleaning operation of Step S22 (arrow Y in FIG. 2).

  As described above, the control device 60 repeatedly executes the processing from step S6, and calculates the count value C1 based on the determination result in each processing. Then, based on the calculated count value C1, it is determined whether or not bubbles are generated in the cleaning tank 14 (that is, whether to shift to a defoaming operation or to shift to a cleaning operation). Therefore, generation | occurrence | production of the bubble in the washing tank 14 can be detected correctly.

Further, as described above, when the general detergent is put, bubbles are generated in the cleaning tank 14 during the execution of step S6. Since the bubbles generated in the cleaning tank 14 do not disappear in a short time, the bubbles are accumulated in the cleaning tank 14 every time Step S6 is executed. Therefore, step S6 executed later is executed with more bubbles in the cleaning tank 14 than step S6 executed earlier. If there are many bubbles in the cleaning tank 14, the bubbles are caught in the cleaning pump 28, so that bubbles are generated in the cleaning pump 28. Then, the bubble generation speed increases. That is, the bubble generation speed is faster in step S6 executed later.
Therefore, the control device 60 shortens the execution time in step S6 to be executed later. Specifically, as described above, in the first step S6, the cleaning pump 28 is operated for 30 seconds. In the second step S6, the cleaning pump 28 is operated for 20 seconds. In the third step S6, the cleaning pump 28 is operated for 15 seconds. In the fourth step S6, the cleaning pump 28 is operated for 10 seconds. In this way, even if the execution time of step S6 to be executed later is shortened, the bubble generation speed is increased in step S6 to be executed later when the general detergent is added, so that the generation of bubbles can be accurately detected. it can. Further, the execution time of the entire process of FIG. 2 is shortened by shortening the execution time in step S6 performed later. Therefore, it is possible to detect the occurrence of bubbles in a short time.

  As described above, the dishwasher 10 according to the present embodiment operates the fan 52 to raise the water level in the water level chamber 45 and then stops the fan 52, and the water level chamber 45 after the fan 52 stops. The generation of bubbles in the cleaning tank 14 is detected based on the water level lowering rate. Therefore, generation | occurrence | production of a bubble can be detected hardly receiving the influence of the variation in the water level in the washing tank 14 after the injection process of step S6. For this reason, it is not necessary to perform the injection stroke of step S6 for a long time. The generation of bubbles can be detected in a short time.

  Moreover, in the tableware washing machine 10 mentioned above, when the water level detection apparatus 46 is turned off after the injection stroke of step S6, the blowing process of step S10 is performed, and when the water level detection apparatus 46 is turned on by the blowing process, step S12 is performed. In S14, it is determined whether or not the water level detection device 46 is turned off within 10 seconds (that is, whether or not the water level lowering speed is equal to or higher than a certain speed). Therefore, it is possible to detect the generation of bubbles using a simple water level detection means for detecting whether or not the water level in the water level chamber 45 has reached the reference water level.

  Moreover, the tableware washing machine 10 mentioned above complete | finishes step S10, when the water level detection apparatus 46 turns on by step S10 (namely, the fan 52 is stopped). Therefore, the water level in the water level chamber 45 at the start of step S12 becomes a slightly higher water level than the reference water level. That is, there is little variation in the water level in the water level chamber 45 at the start of step S12. Therefore, it is possible to accurately detect whether or not the water level lowering speed is equal to or higher than a certain speed by the determination in step S14. Generation of bubbles can be detected more accurately.

  Moreover, the tableware washing machine 10 mentioned above adjusts the water level in the washing tank 14 to a reference | standard water level (step S4 or S20), and starts the injection process of step S6 after that. Therefore, when the water level is lowered in step S6, the water level in the water level chamber 45 is slightly lower than the reference water level. This makes it easier for the water level in the water level chamber 45 to reach the reference water level during the blowing process of step S10.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

1 is a schematic sectional view of the dishwasher 10. The flowchart which shows the process which detects a bubble. Explanatory drawing of the water level in the water level chamber 45 and the washing tank 14. FIG.

Explanation of symbols

10: Tableware washing machine 12: Case 14: Washing tank 15: Door 22: Washing nozzle 28: Washing pump 36: Drain pipe 43: Water supply pipe 45: Water level chamber 46: Water level detection device 49: Water level detection switch 50: Communication path 52 : Fan 54: Air supply pipe 56: Lid 60: Control device

Claims (6)

A washing tank;
A cleaning nozzle for injecting cleaning water into the cleaning tank;
A cleaning pump that sucks the cleaning water in the cleaning tank and sends it to the cleaning nozzle;
A fan that sends air into the cleaning tank;
A water level chamber in communication with the washing tank;
Water level detection means for detecting the water level in the water level chamber;
Equipped with a control device,
The control unit
After supplying water to the washing tank, an injection stroke in which the washing pump is operated to inject washing water into the washing tank from the washing nozzle;
After the injection stroke, a blower process that operates the fan to send air into the cleaning tank;
A water level lowering speed determination process for determining whether or not the water level in the water level chamber decreases at a speed equal to or higher than a reference speed after the air blowing process;
The dishwasher characterized by performing the foam detection process containing. The water level detection means is means for detecting whether or not the water level in the water level chamber has reached the reference water level,
The control device, in the bubble detection process,
After the injection stroke and before the blowing process, a water level determination process is performed to determine whether the water level in the water level chamber has reached the reference water level,
When it is determined in the water level determination process that the water level in the water level chamber has not reached the reference water level, the air blowing process is executed,
In the blowing process, it is determined whether the water level in the water level chamber reaches the reference water level,
When it is determined that the water level in the water level chamber has reached the reference water level in the blowing process, the water level lowering speed determination process is executed,
2. The dishwasher according to claim 1, wherein in the water level lowering speed determination process, it is determined whether or not the water level in the water level chamber falls below a reference water level within a predetermined time from the end of the blowing process.   3. The dishwasher according to claim 2, wherein the control device ends the blowing process when it is determined that the water level in the water level chamber has reached the reference water level during the blowing process.   4. The dishwasher according to claim 2, wherein the control device starts the injection stroke in a state where the water level in the washing tank is adjusted to the reference water level.   The control device repeatedly executes the bubble detection process, and calculates a bubble determination index value based on the determination results of the water level determination process, the air blowing process, and the water level lowering speed determination process in each bubble detection process. The dishwasher as described in any one of Claims 2-4.   6. The dishwasher according to claim 5, wherein the control device shortens the execution time as the injection stroke is executed later.

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