Patent Application
20190290096
The present disclosure relates generally to dishwasher appliances, and more particularly to dishwasher appliances having flood detection features.
Dishwasher appliances generally include a tub that defines a wash chamber. Rack assemblies can be mounted within the wash chamber of the tub for receipt of articles for washing. Multiple spray assemblies can be positioned within the wash chamber for applying or directing wash fluid towards articles disposed within the rack assemblies in order to clean such articles. Dishwasher appliances are also typically equipped with a circulation pump for circulating fluid through the multiple spray assemblies.
Under certain conditions, dishwasher appliances are prone to flooding over a tub lip of the tub. For instance, dishwasher appliances may be prone to flooding over the tub lip during an out-of-level condition, an inlet water valve failure, and/or a drain pump failure. When one or more of such conditions occur, the water level can rise above the designed fill level and spill over the tub lip and onto the floor. This may be detrimental to consumers' homes.
Some conventional dishwasher appliances include features for detecting tub overfills or flood events. For example, some dishwasher appliances include float sensors for detecting such flood events. While flood detection features of conventional dishwasher appliances are capable of detecting such flood events, the feedback from such detection features is generally not used proactively to attempt to stop the flood event or mitigate the flood damage. Moreover, generally no information as to the source of the flood event is provided to service professionals.
Accordingly, a dishwasher appliance that includes flood prevention and protection features and methods therefore that address one or more of the challenges noted above would be useful.
The present disclosure provides a dishwasher appliance equipped with flood protection features that proactively attempt to prevent, stop, or mitigate flood events. The dishwasher appliance may also include features for determining the cause of the flood event. Moreover, methods for flood protection of the dishwasher appliance are also provided. Additional aspects and advantages of the invention will be set forth in part in the following description, may be apparent from the description, or may be learned through practice of the invention.
In accordance with one exemplary embodiment, a method for flood protection of a dishwasher appliance is provided. The dishwasher appliance includes a drain pump, a cabinet, and a tub positioned within the cabinet. The tub has a tub lip. The method includes determining whether wash fluid is present at or proximate the tub lip at a first time; activating the drain pump to run a drain cycle if wash fluid is present at or proximate the tub lip at the first time; ascertaining whether a current time is greater than or equal to a predetermined drain time; determining whether wash fluid is present at or proximate the tub lip at a second time if the current time is greater than or equal to the predetermined drain time; and pulsing the drain pump if wash fluid is present at or proximate the tub lip at the second time.
In accordance with another exemplary embodiment, a method for flood protection of a dishwasher appliance is provided. The dishwasher appliance includes a drain pump, a water inlet valve, a cabinet, and a tub positioned within the cabinet. The tub has a tub lip. The method includes determining whether wash fluid is present at or proximate the tub lip at a first time; activating the drain pump to run a drain cycle if wash fluid is present at or proximate the tub lip at the first time; ascertaining whether a current time is greater than or equal to a predetermined drain time; determining whether wash fluid is present at or proximate the tub lip at a second time if the current time is greater than or equal to the predetermined drain time; deactivating the drain pump if wash fluid is not present at or proximate the tub lip at the second time; ascertaining if a count is greater than or equal to a count threshold; and pulsing the water inlet valve if wash fluid is present at or proximate the tub lip if the count is greater than or equal to the count threshold.
In accordance with yet another exemplary embodiment, a dishwasher appliance is provided. The dishwasher appliance includes a cabinet and a tub positioned within the cabinet. The tub defining a wash chamber for receipt of articles for washing. The tub has a tub lip. The dishwasher appliance further includes a tub lip sensor mounted on the tub lip and configured to detect wash fluid at or proximate the tub lip. In addition, the dishwasher appliance includes a water inlet valve for selectively allowing wash fluid into the wash chamber. Further, the dishwasher appliance includes a drain pump for draining wash fluid from the tub. Moreover, the dishwasher appliance includes a controller communicatively coupled with the tub lip sensor, the water inlet valve, and the drain pump, the controller configured to: determine, at a first time, whether the tub lip sensor has sensed wash fluid at or proximate the tub lip for a predetermined time; activate the drain pump to run a drain cycle if wash fluid is present at or proximate the tub lip at the first time; ascertain whether a current time is greater than or equal to a predetermined drain time; determine, at a second time, whether the tub lip sensor has sensed wash fluid at or proximate the tub lip for a predetermined time if the current time is greater than or equal to the predetermined drain time; and i) wherein if wash fluid is present at or proximate the tub lip at the second time: ascertain whether a pulse flag is less than or equal to a pulse threshold; and pulse the drain pump if the pulse flag is less than or equal to the pulse threshold; or ii) wherein if wash fluid is not present at or proximate the tub lip at the second time: deactivate the drain pump; ascertain whether a current count is greater than or equal to a count threshold; and pulse the water inlet valve if the current count is greater than or equal to the count threshold.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.
Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
As used herein, the term “article” may refer to, but need not be limited to dishes, pots, pans, silverware, and other cooking utensils and items that can be cleaned in a dishwashing appliance. The term “wash cycle” is intended to refer to one or more periods of time during which a dishwashing appliance operates while containing the articles to be washed and uses a detergent and water, to e.g., remove soil particles including food and other undesirable elements from the articles. The term “rinse cycle” is intended to refer to one or more periods of time during which the dishwashing appliance operates to remove residual soil, detergents, and other undesirable elements that were retained by the articles after completion of the wash cycle. The term “drain cycle” is intended to refer to one or more periods of time during which the dishwashing appliance operates to discharge soiled water from the dishwashing appliance. The term “wash fluid” refers to a liquid used for washing and/or rinsing the articles and is typically made up of water that may include other additives such as detergent or other treatments. Furthermore, as used herein, terms of approximation, such as “approximately,” “substantially,” or “about,” refer to being within a ten percent (10%) margin of error.
Tub 104 includes a front opening 114 (
As further shown in
Some or all of the rack assemblies 122, 124, 126 are fabricated into lattice structures including a plurality of wires or elongated members 130 (for clarity of illustration, not all elongated members making up rack assemblies 122, 124, 126 are shown in
Dishwasher 100 further includes a plurality of spray assemblies for urging a flow of water or wash fluid onto the articles placed within wash chamber 106. More specifically, as illustrated in
The various spray assemblies and manifolds described herein may be part of a fluid distribution system or fluid circulation assembly 150 for circulating water and wash fluid in tub 104. More specifically, fluid circulation assembly 150 includes a circulation pump 152 for circulating water and wash fluid (e.g., detergent, water, and/or rinse aid) in tub 104. Circulation pump 152 is located within sump 138 or within a machinery compartment located below sump 138 of tub 104. Circulation pump 152 is in fluid communication with an external water supply line (not shown) and sump 138. A water inlet valve 153 is positioned between the external water supply line and circulation pump 152 to selectively allow water to flow from the external water supply line to circulation pump 152. Additionally or alternatively, water inlet valve 153 may be positioned between the external water supply line and sump 138 to selectively allow water to flow from the external water supply line to sump 138. Water inlet valve 153 may be an electro-mechanical valve that can be selectively controlled to open to allow the flow of water into dishwasher 100 and can be selectively controlled to cease the flow of water into dishwasher 100. Further, fluid circulation assembly 150 may include one or more fluid conduits or circulation piping for directing water and/or wash fluid from circulation pump 152 to the various spray assemblies and manifolds. For example, for the embodiment depicted in
As further illustrated in
Each spray arm assembly 134, 140, 142, integral spray manifold 144, or other spray device may include an arrangement of discharge ports or orifices for directing wash fluid received from circulation pump 152 onto dishes or other articles located in wash chamber 106. The arrangement of the discharge ports, also referred to as jets, apertures, or orifices, may provide a rotational force by virtue of wash fluid flowing through the discharge ports. Alternatively, spray arm assemblies 134, 140, 142 may be motor-driven, or may operate using any other suitable drive mechanism. Spray manifolds and assemblies may also be stationary. The resultant movement of the spray arm assemblies 134, 140, 142 and the spray from fixed manifolds provides coverage of dishes and other dishwasher contents with a washing spray. Other configurations of spray assemblies may be used as well. For example, dishwasher 100 may have additional spray assemblies for cleaning silverware, for scouring casserole dishes, for spraying pots and pans, for cleaning bottles, etc.
In operation, circulation pump 152 draws wash fluid in from sump 138 and pumps it to a diverter 156, e.g., which is positioned within sump 138 of dishwasher appliance. Diverter 156 may include a diverter disk (not shown) disposed within a diverter chamber 158 for selectively distributing the wash fluid to the spray arm assemblies 134, 140, 142 and/or other spray manifolds or devices. For example, the diverter disk may have a plurality of apertures that are configured to align with one or more outlet ports (not shown) at the top of diverter chamber 158. In this manner, the diverter disk may be selectively rotated to provide wash fluid to the desired spray device.
According to an exemplary embodiment, diverter 156 is configured for selectively distributing the flow of wash fluid from circulation pump 152 to various fluid supply conduits, only some of which are illustrated in
Drainage of soiled water within sump 138 may occur, for example, through drain assembly 166. In particular, water may exit sump through a drain and may flow through a drain conduit 167. A drain pump 168 may facilitate drainage of the soiled water by pumping the water to a drain line external to the dishwasher 100.
Dishwasher 100 is further equipped with a controller 160 to regulate operation of dishwasher 100. Controller 160 may include one or more memory devices and one or more microprocessors, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In some embodiments, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. Alternatively, controller 160 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.
Controller 160 may be positioned in a variety of locations throughout dishwasher 100. In the illustrated embodiment, controller 160 may be located within a control panel area 162 of door 116 as shown in
It should be appreciated that the invention is not limited to any particular style, model, or configuration of dishwasher 100. The exemplary embodiment depicted in
With reference still to
Notably, for the depicted embodiment of
In the depicted embodiment of
At (302), method (300) includes powering up or operating a dishwasher. For instance, dishwasher 100 can be powered in a standby mode (e.g., power is supplied to dishwasher 100 but dishwasher is not performing a cycle). Moreover, dishwasher 100 can be operated in a given cycle, including for example, a fill cycle, a circulation cycle, a drain cycle, or a dry cycle. So long as power is supplied to dishwasher 100, method (300) commences at (302). When method (300) commences, dishwasher appliance 100 constantly monitors for flood events. In particular, controller 160 may monitor for flood events by receiving an output signal generated by tub lip sensor 200 continuously at a predetermined interval or time step, such as e.g., every tenth of a second, every half second, every second, etc. Controller 160 can receive the output signals directly or indirectly from tub lip sensor 200.
At (304), method (300) includes determining whether wash fluid is present at or proximate the tub lip at a first time. If wash fluid is detected at or proximate tub lip 170 at the first time, dishwasher appliance 100 is either experiencing or about to experience a flood event. Accordingly, in accordance with exemplary aspects of the present disclosure, corrective action may be taken to prevent or mitigate the impending flood event. As such, the control logic proceeds to (306) so that corrective action may be taken. If wash fluid is not present at or proximate tub lip 170 at the first time, as determined at (304), a flood event is not imminent, and thus, the control logic loops back to (302) to continue monitoring for flood events. The first time is representative of the first time in the control logic that controller 160 checks if wash fluid is present at or proximate tub lip 170. If there is in fact wash fluid at or proximate tub lip 170 at the first time as determined at (304), as will be explained below, controller 160 again checks if wash fluid is present at or proximate tub lip 170 at a second time (i.e., at 310).
In some exemplary implementations at (304), method (300) includes determining, at the first time, whether wash fluid is present at or proximate the tub lip for a predetermined time. The predetermined time may be, for example, between about three (3) and five (5) seconds. Preferably, in some implementations, in determining, at the first time, whether wash fluid is present at or proximate tub lip 170 for the predetermined time, wash fluid must be present at or proximate tub lip 170 consecutively for the predetermined time. Stated alternatively, wash fluid must be detected at or proximate tub lip 170 for the entire predetermined period. In this way, for implementations where tub lip sensor is configured to detect whether wash fluid is present at or proximate tub lip 170, it is less probable or likely that tub lip sensor 200 has been inadvertently or nuisance tripped by splashing wash fluid if wash fluid is required to be present at or proximate the predetermined time or consecutively for the predetermined time.
In some implementations, as noted above, tub lip sensor 200 is configured to detect whether wash fluid is present at or proximate tub lip 170 at the first time. As one example, where tub lip sensor 200 is a conductivity sensor as noted above, to sense wash fluid at or proximate tub lip 170, if tub lip sensor 200 is closed for a consecutive predetermined time (e.g., wash fluid has breached the leads of the sensor for a consecutive period of time), it may be determined that wash fluid is present at or proximate tub lip 170, and thus, it may be determined that a flood event has likely occurred or about to occur. If, however, tub lip sensor 200 remains open or has not closed for a consecutive predetermined time, a determination may be made that wash fluid is not present at or proximate tub lip 170. Consequently, it may be determined that a flood event has likely not occurred or about to occur. Controller 160 may be configured to determine whether or not tub lip sensor 200 is open or closed, and thus whether wash fluid is present at or proximate the tub lip 170.
At (306), method (300) includes activating the drain pump to run a drain cycle if wash fluid is present at or proximate the tub lip at the first time. Stated differently, at (306), corrective action in response to the detected flood event is taken. Preferably, drain pump 168 removes wash fluid from sump 138 and tub 104 at a faster rate than water and/or wash fluid flows into sump 138. In this manner, drain pump 168 can overcome the flow rate of water inlet valve 153, particularly if water inlet valve 153 has failed. Further, in some implementations, drain pump 168 removes wash fluid from sump 138 at twice or at least twice the rate of wash fluid entering sump 138. As one example, drain pump 168 removes fluid from sump 138 at three (3) gallons per minute (gpm) and water inlet valve 153 allows for a flow rate into sump 138 at a flow rate of 0.8 gpm.
In some implementations, at (306), the method (300) includes starting a timer. Preferably, the starting of the timer is coordinated with the activation of drain pump 168. That is, the timer is started upon activation of drain pump 168. The timer can be a component of controller 160 or can be a separate component communicatively coupled with controller 160, for example. The timer is started so that the run time of drain pump 168 may be tracked, among other reasons as will be described herein.
Further, in implementations where dishwasher 100 is performing a cycle, particularly a rinse or wash cycle, additionally or alternatively to activating drain pump 168, at (306), method (300) includes cancelling a current cycle of the dishwasher appliance if wash fluid is present at the tub lip as determined at (304). When wash fluid is detected or determined to be present at tub lip 170, controller 160 effectively determines that a flood event has occurred or is on the verge or precipice of a flood event, as noted above. Thus, equipped with such information, dishwasher 100 can take corrective action to potentially prevent the flood event or reduce the potential damage of the flood event. Cancelling a current cycle of dishwasher appliance 100 may facilitate flood prevention or may mitigate flood damage.
As one example, as noted above, the current cycle being performed by dishwasher appliance 100 can be canceled. For instance, if dishwasher 100 is performing a wash or rinse cycle, to cancel the cycle, method (300) can include deactivating water inlet valve 153 (e.g., closing the valve to a closed position (assuming it is still operable)) to prevent further water from entering dishwasher 100. Moreover, method (300) can likewise include deactivating circulation pump 152. In this way, energy can be conserved and will allow the wash fluid to flow back to sump 138 such that it can be removed from dishwasher 100.
In some further implementations, at (306), method (300) includes logging a flood fault. In this way, if dishwasher 100 is serviced, an operator, service professional, or consumer may quickly ascertain why dishwasher 100 was cancelled mid-cycle. Moreover, in some implementations, as shown at (306), method (300) includes notifying a consumer that the cycle has been cancelled and that a flood event or possible flood event has occurred. For instance, as one example, dishwasher 100 may include a speaker that audibly communicates the notification to a consumer. As another example, dishwasher 100 may include a communication interface that is communicatively coupled with controller 160. The communication interface may include a network interface that provides for communication over a network, such as e.g., a wireless network. In such implementations, dishwasher 100 may send notifications to a consumer's user device, such as e.g., a cell phone.
Further, in some exemplary implementations, at (306), method (300) includes adding one (1) count to a count. For instance, the one count may be a value of one (1) that is added to a counter of controller 160 or a counter that is communicatively coupled with controller 160. As will be explained further below, controller 160 may control various components to take certain actions depending on the current count of counter.
In some exemplary implementations, at (306), method (300) includes setting a pulse flag equal to zero (0). For instance, setting the pulse flag equal to zero (0) may include setting a pulse flag counter of a pulse generator equal to zero (0). The pulse generator may be, for example, a pulse generator circuit in electrical communication with drain pump 168 and/or water inlet valve 153. The pulse flag counter and pulse generator circuit may be onboard controller 160 or may be offboard components.
At (308), method (300) includes ascertaining whether a current time is greater than or equal to a predetermined drain time. For instance, at (308), it is determined whether a current time T is greater than or equal to the predetermined drain time TDRAIN. In some implementations, the predetermined drain time TDRAIN is set to correspond with an estimated time in which drain pump 168 should drain dishwasher appliance 100 if drain pump 168 is working properly. For example, the predetermined drain time TDRAIN may be thirty seconds (30 s). The current time T may be kept by the timer. If the current time T is greater than or equal to the predetermined drain time TDRAIN, the controller logic proceeds to (310) to see if the wash fluid within tub 104 has actually been drained. If the current time T is not greater than or equal to the predetermined drain time TDRAIN, then the controller logic loops back to (308) as shown in
At (310), if the current time T is determined to be greater than or equal to the predetermined drain time TDRAIN, method (300) includes determining, at the second time, whether wash fluid is present at or proximate the tub lip. By this time (i.e., at the second time), if drain pump 168 is working properly, the wash fluid should be drained from dishwasher appliance 100 such that wash fluid should no longer be present at tub lip 170. This is true even if water inlet valve 153 has failed, as drain pump 168 is preferably configured to drain wash fluid from dishwasher appliance 100 at a faster rate than water may enter dishwasher 100 through water inlet valve 153. As such, if wash fluid is no longer present at or proximate tub lip 170 at the second time, it may be determined that drain pump 168 is working properly and the control logic proceeds to (320). If, however, wash fluid is still present at tub lip 170 after the current time T is determined to be greater than or equal to the predetermined drain time TDRAIN, drain pump 168 has very likely malfunctioned or otherwise failed to drain the wash fluid from dishwasher appliance 100. Accordingly, the control logic proceeds to (312) so that corrective action may be taken to attempt to correct the draining issue. The same or similar methods and components used to determine whether wash fluid is present at or proximate tub lip at (304) may be used to determine whether wash fluid is present at or proximate the tub lip at (310).
For instance, in some exemplary implementations at (310), method (300) includes determining, at the second time, whether wash fluid is present at or proximate the tub lip for a predetermined time. That is, in some implementations, at (310) it is determined, at the second time, whether tub lip sensor 200 has sensed wash fluid at or proximate tub lip 170 for a predetermined time. The predetermined time may be, for example, between about three (3) and five (5) seconds. Preferably, in some implementations, in determining whether the tub lip sensor 200 has sensed wash fluid at or proximate tub lip 170 for the predetermined time, wash fluid must be sensed at or proximate tub lip 170 consecutively for the predetermined time. Stated alternatively, tub lip sensor 200 must sense wash fluid at or proximate the tub lip 170 for the entire predetermined period. In this way, it is less probable or likely that tub lip sensor 200 has been inadvertently or nuisance tripped by splashing wash fluid.
At (312), method (300) includes ascertaining whether the pulse flag is less than or equal to a pulse threshold if wash fluid is present at or proximate the tub lip at the second time. That is, if the current time T is greater than or equal to the predetermined drain time TDRAIN and if wash fluid is present at or proximate tub lip 170 at the second time as determined at (308) and (310), respectively, it is determined whether the pulse flag PF is less than or equal to the pulse threshold PT. As one example, the pulse threshold PT may be set to a value of three (3). Of course, other pulse threshold PT values are possible. If the pulse flag PF is not less than or equal to the pulse threshold PT, then the control logic proceeds to (316), and in contrast, if the pulse flag PF is less than or equal to the pulse threshold PT, then the control logic proceeds to (314) as shown in
At (314), if the pulse flag PF is less than or equal to the pulse threshold PT as determined at (312), method (300) includes pulsing the drain pump. In some instances, debris, such as e.g., olive pits, popcorn kernels, detergent, etc., may clog drain pump 168, preventing drain pump 168 from draining wash fluid from tub 104. For example, debris may clog drain pump 168 so that the impeller blades of the pump cannot turn. By pulsing drain pump 168, drain pump 168 may jolt during the pulses, and in some instances, the debris can become dislodged such that drain pump 168 may resume normal operation, and consequently, drain pump 168 may drain wash fluid from dishwasher 100.
Drain pump 168 may be pulsed in any suitable fashion. As one example, drain pump 168 may be pulsed “on” and “off” rapidly. In some instances, pulsing includes switching drain pump 168 “on” and “off” at a predetermined frequency for a predetermined pulse time (e.g., three seconds (3 s)). As another example, drain pump 168 can remain “on” and a series of square wave electric pulses may be generated by the pulse generator circuit and routed to the drain pump motor to pulse drain pump 168. When the motor is pulsed, the torque on the output shaft of the motor may in turn torque the impeller in such a way that the debris becomes dislodged. In yet other instances, the electronics of drain pump 168 may malfunction or fail. By pulsing drain pump 168, the motor of drain pump 168 may jolt during the pulses. In some instances, pulsing drain pump 168 may electrically revive the motor or other electrical components of drain pump 168 and essentially “kick start” drain pump 168 back into operation.
Further, at (314), in some implementations in addition to pulsing the drain pump, method (300) includes resetting the timer. The timer is reset so that when the control logic loops back to (308) so that drain pump 168 may be activated to run further drain cycles after pulsing, the current time T is refreshed to zero (0). Drain pump 168 is activated for the second and subsequent drain cycles when the control logic returns to (308) as drain pump 168 has not been commanded to deactivate after being activated at (306). Then, as noted above, the current time T is checked against the predetermined drain time TDRAIN of drain pump 168, for a second drain cycle, a third drain cycle, and so on if the wash fluid continues to be present at the second time (i.e., at 310) and the pulse flag PF is less than or equal to the pulse threshold PT.
Moreover, at (314), in some implementations method (300) includes adding a pulse flag count to the pulse flag. In this way, when the control logic loops back to (308) so that drain pump 168 may perform a second drain cycle (or another subsequent drain cycle) and then to (310), if wash fluid is still present at or proximate the tub lip as determined at (310), the value of the pulse flag PF will eventually be greater than the pulse flag threshold PT as determined at (312). In this way, after a certain number of pulse attempts to revive drain pump 168, either electrically or mechanically, it is determined that pulsing drain pump 168 is simply not correcting the draining issue. Accordingly, if at (312) it is determined that the pulse flag PF is less than or equal to the pulse flag threshold PT, then the control logic proceeds to (316).
At (316), method (300) includes logging a drain fault. The drain fault logged may be indicative that dishwasher 100 is experiencing a flood event, that corrective action was taken to attempt to fix the draining issue, and that the corrective action taken was not successful. The drain fault is logged to assist an operator, service professional, or consumer with taking corrective action. In addition, in some implementations, method (300) includes notifying the consumer that dishwasher 100 is experiencing a flood event, that corrective action was taken (i.e., drain pump 168 was pulsed), and that the corrective action taken was not successful. In this way, a consumer can take necessary corrective actions to prevent dishwasher 100 from flooding. A consumer may be notified in any of the exemplary ways noted above at (306). After logging the drain fault and notifying the consumer at (316), method (300) loops back to (302) where method (300) commences once more.
At (318), method (300) includes resetting the timer. Thereafter, the control logic proceeds to (302) where method (300) repeats to continue monitoring for flood events.
At (320), if no wash fluid is present at or proximate tub lip 170 as determined at (310), method (300) includes deactivating the drain pump. As noted above, if it is determined at (310) that wash fluid is not present at or proximate tub lip 170, then wash fluid is not in imminent danger of spilling over tub lip 170, and accordingly, drain pump 168 is deactivated.
At (322), method (300) includes ascertaining whether the current count is greater than or equal to a count threshold. If the current count is greater than or equal to the count threshold CT, this is an indication that water inlet valve 153 has likely experienced a failure or has in some way malfunctioned. The count threshold CT may correspond with a value of two (2) or three (3), for example. The counts correspond with the number of times wash fluid is determined to be present at or proximate tub lip 170 at (304). For instance, each time it is determined that wash fluid is present at or proximate tub lip 170 as determined at (304), then at (306) one count is added to the counter, as noted previously. Thus, each time method (300) iterates or repeats and wash fluid is determined to be present at or proximate tub lip 170 at (304), the count value is increased by one (1) each time at (306).
Accordingly, if wash fluid continues to be detected at or proximate tub lip 170 even after drain pump 168 has drained tub 104 on a number of occasions, the current count will eventually be greater than or equal to the count threshold CT as determined at (322). As recursive filling and draining cycles within a certain period of time is indicative of a water inlet valve failure, dishwasher 100 attempts to take corrective action at (324).
At (324), if the current count is greater than or equal to the count threshold CT as determined at (322), method (300) includes pulsing the water valve. Stated differently, if it is determined that too many fill and drain cycles have occurred in a certain time frame as represented by the count value, then dishwasher 100 assumes that water inlet valve 153 has failed or has in some way malfunctioned and attempts to take corrective action. Pulsing water inlet valve 153 is one corrective action in which dishwasher 100 may take.
Water inlet valve 153 may be electrically controlled, and accordingly, water inlet valve 153 may be electrically pulsed in attempt to switch the water valve from an open positioned to a closed position. In some instances, various internal components of water inlet valve 153 (e.g., a diaphragm) may become stuck such that water inlet valve 153 remains in an open position, ultimately causing the relatively rapid fill/drain cycles as shown in
Water inlet valve 153 may be pulsed in any suitable fashion. For example, water inlet valve 153 may be switched “off” and “on” a number of times. In some instances, pulsing includes switching water inlet valve 153 “on” and “off” at a predetermined frequency for a predetermined pulse time. As another example, water inlet valve 153 may remain “on” and a series of square wave electric pulses may be generated by the pulse generator circuit and routed to water inlet valve 153.
Moreover, in some implementations at (324), method (300) includes logging a valve fault. The valve fault is logged to assist an operator, service professional, or consumer with taking corrective action. Additionally, in some implementations at (324), method (300) includes setting the counter equal to zero (0). In this way, water inlet valve 153 will not continue to be pulsed with every successive iteration. However, if method (300) iterates to (322) enough times, eventually the current count will be greater than or equal to the count threshold CT once again, and accordingly, the control logic will proceed to (324) where water inlet valve 153 will once again by pulsed. Further, in some implementations at (324), method (300) includes resetting the timer. Thereafter, the control logic proceeds to (326).
At (326), method (300) includes determining whether the current time is greater than or equal to a count interval time TCOUNT. The current time T is checked against the count interval time TCOUNT so that water inlet valve 153 is only pulsed when a certain number of counts occur within a certain time frame, i.e., within a particular count interval time period TCOUNT. Within a particular count interval time period TCOUNT, the counter continues to accumulate counts each time wash fluid is detected to be present at or proximate tub lip 170 at (304), as one count is added to counter at (306) each time this occurs, as previously described. If the current time, as kept by the timer started at (306), is not greater than or equal to the count interval period TCOUNT, then the control logic proceeds to (302) with the accumulated count. However, once the count interval time TCOUNT ends, i.e., when the current time T is greater than or equal to the count interval time TCOUNT, the control logic proceeds to (328) where the count is set to zero (0). Thus, for water inlet valve 153 to undergo pulsing at (324), a certain number of fill/drain cycles must occur within a particular time frame.
At (328), method (300) includes setting the count equal to zero (0) if the current time is greater than or equal to the count predetermined drain time TCOUNT. Thereafter, the control logic proceeds to (302) where method (300) then continues to monitor for flood events.
To further the understanding of the relationship between (304), (306), (322), (324), (326), and (328), examples are provided below. With reference to
As a second example, suppose the count time interval TCOUNT is set to four (4) minutes, the count threshold CT is set to a value of three (3), and that wash fluid is filled and drained in tub 104 as shown in
Determining whether the current time is greater than or equal to the count interval time TCOUNT at (326) thus requires that the counts occur within a certain period of time in order for water inlet valve 153 to be pulsed at (324). Such requirement ensures that water inlet valve 153 is indeed the likely source of the flood event before it is pulsed. In short, on one hand, if a certain number of counts occur close enough in time together as in the first example, it is determined that water inlet valve 153 has likely malfunctioned and thus water inlet valve 153 is pulsed at (324). On the other hand, if a certain number of counts occur but not close enough in time together as in the second example it is determined that water inlet valve 153 has likely not malfunctioned and thus water inlet valve 153 is not pulsed at (324).
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
