Patent Application
20230374716
The present subject matter relates generally to evaluating temperatures in laundry appliances, or more specifically, to determining if a temperature sensor in the laundry appliance is providing erroneous readings, thereby necessitating service.
Washing machine appliances generally include a tub for containing water or wash fluid, e.g., water and detergent, bleach, and/or other wash additives. A drum is rotatably mounted within the tub and defines a wash chamber for receipt of articles for washing. During normal operation of such washing machine appliances, the wash fluid is directed into the tub and onto articles within the wash chamber of the drum. The drum or an agitation element can rotate at various speeds to agitate articles within the wash chamber, to wring wash fluid from articles within the wash chamber, etc. During a spin or drain cycle of a washing machine appliance, a drain pump assembly may operate to discharge water from within sump.
For many types of wash cycles, the temperature of the water may play an important role in cleaning of the articles for washing. The temperature is determined via a thermistor within the tub that directly measures the water temperature therein. Failure of the thermistor to properly read the water temperature will inhibit that ability of the washing machine appliance to carry out heated wash cycles effectively.
Conventional washing machine appliances attempt to address the problem by assessing whether the temperature significantly exceeds or falls short of expected normal operating temperatures. This approach works well when the thermistor has completely failed but is ineffective where a thermistor is malfunctioning but still provides a reading within expected thresholds. Even in this circumstance, however, washing performance may be significantly hampered by the misreading.
Accordingly, a laundry appliance including features and operating methods for monitoring for temperature sensor malfunctions is desirable. More specifically, it would be desirable to determine if a temperature sensor's reading is accurate or whether replacement of the temperature sensor is necessary.
Advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.
In one exemplary embodiment, a laundry appliance is provided including a cabinet, a tub within the cabinet, a drum rotatably mounted within the tub and defining a chamber, an exhaust in fluid communication with the chamber, a first temperature sensor, a second temperature sensor, and a controller operably coupled to the first temperature sensor and the second temperature sensor. The controller may be configured to execute a wash cycle, receive a first temperature of the first temperature sensor, receive a first temperature of the second temperature sensor, receive a second temperature of the first temperature sensor, receive a second temperature of the second temperature sensor, determine the temperature change of the first temperature sensor and the second temperature sensor based at least in part on the first temperature and the second temperature of the first temperature sensor and the second temperature sensor, compare the temperature change of the first temperature sensor to the temperature change of the second temperature sensor, and determine if either of the first temperature sensor or the second temperature sensor are malfunctioning based on the comparison.
In another exemplary embodiment, a method is provided of monitoring for temperature sensor malfunction in a laundry appliance having a cabinet, a tub within the cabinet, a drum rotatably mounted within the tub and defining a chamber, an exhaust in fluid communication with the chamber, a first temperature sensor in the tub for measuring water temperature, and a second temperature sensor in a humidity sensor disposed in the exhaust for measuring air temperature. The method may comprise the steps of executing a wash cycle, receiving a first temperature of the first temperature sensor, receiving a first temperature of the second temperature sensor, receiving a second temperature of the first temperature sensor, receiving a second temperature of the second temperature sensor, determining the temperature change of the first temperature sensor and the second temperature sensor based at least in part on the first temperature and the second temperature of the first temperature sensor and the second temperature sensor, comparing the temperature change of the first temperature sensor to the temperature change of the second temperature sensor, and determining if either of the first temperature sensor or the second temperature sensor are malfunctioning based on the comparison.
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.
Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.
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 terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “includes” and “including” are intended to be inclusive in a manner similar to the term “comprising.” Similarly, the term “or” is generally intended to be inclusive (i.e., “A or B” is intended to mean “A or B or both”). Approximating language, as used herein throughout the specification and claims, is applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. For example, the approximating language may refer to being within a 10 percent margin.
Referring now to the figures, an exemplary laundry appliance that may be used to implement aspects of the present subject matter will be described. Specifically,
Referring to
Drum 120 may define one or more agitator features that extend into wash chamber 126 to assist in agitation and cleaning articles disposed within wash chamber 126 during operation of washing machine appliance 100. For example, as illustrated in
Referring generally to
A window 136 in door 134 permits viewing of drum 120 when door 134 is in the closed position, e.g., during operation of washing machine appliance 100. Door 134 also includes a handle (not shown) that, e.g., a user may pull when opening and closing door 134. Further, although door 134 is illustrated as mounted to front panel 130, it should be appreciated that door 134 may be mounted to another side of cabinet 102 or any other suitable support according to alternative embodiments. Washing machine appliance 100 may further include a latch assembly 138 (see
Referring again to
A drain pump assembly 144 is located beneath wash tub 124 and is in fluid communication with sump 142 for periodically discharging soiled wash fluid from washing machine appliance 100. Drain pump assembly 144 may generally include a drain pump 146 which is in fluid communication with sump 142 and with an external drain 148 through a drain hose 150. During a drain cycle, drain pump 146 urges a flow of wash fluid from sump 142, through drain hose 150, and to external drain 148. More specifically, drain pump 146 includes a motor (not shown) which is energized during a drain cycle such that drain pump 146 draws wash fluid from sump 142 and urges it through drain hose 150 to external drain 148.
A spout 152 is configured for directing a flow of fluid into wash tub 124. For example, spout 152 may be in fluid communication with a water supply 154 (
As illustrated in
In addition, a water supply valve 158 may provide a flow of water from a water supply source (such as a municipal water supply 154) into detergent dispenser 156 and into wash tub 124. In this manner, water supply valve 158 may generally be operable to supply water into detergent dispenser 156 to generate a wash fluid, e.g., for use in a wash cycle, or a flow of fresh water, e.g., for a rinse cycle. It should be appreciated that water supply valve 158 may be positioned at any other suitable location within cabinet 102. In addition, although water supply valve 158 is described herein as regulating the flow of “wash fluid,” it should be appreciated that this term includes, water, detergent, other additives, or some mixture thereof.
Referring again to
Controller 166 may include a memory and microprocessor, such as a general or special purpose microprocessor 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 one embodiment, 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 166 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. Control panel 160 and other components of washing machine appliance 100 may be in communication with controller 166 via one or more signal lines or shared communication busses.
During operation of washing machine appliance 100, laundry items are loaded into drum 120 through opening 132, and washing operation is initiated through operator manipulation of input selectors 162. Wash tub 124 is filled with water, detergent, and/or other fluid additives, e.g., via spout 152 and/or detergent drawer 156. One or more valves (e.g., water supply valve 158) can be controlled by washing machine appliance 100 to provide for filling drum 120 to the appropriate level for the amount of articles being washed and/or rinsed. By way of example for a wash mode, once drum 120 is properly filled with fluid, the contents of drum 120 can be agitated (e.g., with ribs 128) for washing of laundry items in drum 120.
After the agitation phase of the wash cycle is completed, wash tub 124 can be drained. Laundry articles can then be rinsed by again adding fluid to wash tub 124, depending on the particulars of the cleaning cycle selected by a user. Ribs 128 may again provide agitation within drum 120. One or more spin cycles may also be used. In particular, a spin cycle may be applied after the wash cycle and/or after the rinse cycle in order to wring wash fluid from the articles being washed. During a final spin cycle, drum 120 is rotated at relatively high speeds and drain assembly 144 may discharge wash fluid from sump 142. After articles disposed in drum 120 are cleaned, washed, and/or rinsed, the user can remove the articles from drum 120, e.g., by opening door 134 and reaching into drum 120 through opening 132.
Notably, controller 166 of washing machine appliance 100 (or any other suitable dedicated controller) may be communicatively coupled to control panel 160 and input selectors 162, and other components of washing machine appliance 100, such as fan 204, humidity sensor 202, first temperature sensor 216, and second temperature sensor 218 as described below. As explained in more detail below, controller 166 may be programmed or configured for automating elements of the washing machine appliance 100 at particular times as part of particular cycles, e.g., such as initiating an automated drying cycle upon completion of a self-cleaning cycle with little or no user intervention.
Referring still to
External communication system 190 permits controller 166 of washing machine appliance 100 to communicate with external devices either directly or through a network 192. For example, a consumer may use a consumer device 194 to communicate directly with washing machine appliance 100. For example, consumer devices 194 may be in direct or indirect communication with washing machine appliance 100, e.g., directly through a local area network (LAN), Wi-Fi, Bluetooth, Zigbee, etc. or indirectly through network 192. In general, consumer device 194 may be any suitable device for providing and/or receiving communications or commands from a user. In this regard, consumer device 194 may include, for example, a personal phone, a tablet, a laptop computer, or another mobile device.
In addition, a remote server 196 may be in communication with washing machine appliance 100 and/or consumer device 194 through network 192. In this regard, for example, remote server 196 may be a cloud-based server 196, and is thus located at a distant location, such as in a separate state, country, etc. In general, communication between the remote server 196 and the client devices may be carried via a network interface using any type of wireless connection, using a variety of communication protocols (e.g. TCP/IP, HTTP, SMTP, FTP), encodings or formats (e.g. HTML, XML), and/or protection schemes (e.g. VPN, secure HTTP, SSL).
In general, network 192 can be any type of communication network. For example, network 192 can include one or more of a wireless network, a wired network, a personal area network, a local area network, a wide area network, the internet, a cellular network, etc. According to an exemplary embodiment, consumer device 194 may communicate with a remote server 196 over network 192, such as the internet, to provide user inputs, transfer operating parameters or performance characteristics, receive user notifications or instructions, etc. In addition, consumer device 194 and remote server 196 may communicate with washing machine appliance 100 to communicate similar information.
External communication system 190 is described herein according to an exemplary embodiment of the present subject matter. However, it should be appreciated that the exemplary functions and configurations of external communication system 190 provided herein are used only as examples to facilitate description of aspects of the present subject matter. System configurations may vary, other communication devices may be used to communicate directly or indirectly with one or more laundry appliances, other communication protocols and steps may be implemented, etc. These variations and modifications are contemplated as within the scope of the present subject matter.
Referring again to the embodiment of
As shown in
Referring now to
Washing machine appliance 100 may further include a first temperature sensor 216 (
Washing machine appliance 100 may further include a second temperature sensor 218 (
Referring now to
While described in the context of a specific embodiment of horizontal axis washing machine appliance 100, using the teachings disclosed herein it will be understood that horizontal axis washing machine appliance 100 is provided by way of example only. Other washing machine appliances having different configurations, different appearances, and/or different features may also be utilized with the present subject matter as well, e.g., a combination washer/dryer appliance.
Now that the construction of washing machine appliance 100 and the configuration of controller 166 according to exemplary embodiments have been presented, an exemplary method 300 of operating a washing machine appliance will be described. Referring now to
This temperature data is used by controller 166 to determine a temperature change associated with the first temperature sensor 216 and a temperature change associated with the second temperature sensor 218 at step 360. This temperature change is based at least in part on the first temperature and the second temperature of the first temperature sensor 216 and the second temperature sensor 218 at steps 320 through 350. It will be understood that the temperature change is not limited to these data points, however. For example, in certain embodiments, controller 166 may receive a plurality of temperature readings over time from first temperature sensor 216 and second temperature sensor 218. In this scenario, the temperature change determined by controller 166 may be an average change of temperature associated with first temperature sensor 216 and second temperature sensor 218 over a fixed period of time, for example. In alternative embodiments, the temperature change may reflect the absolute differences between the first temperature reading and the most recent temperature reading in each of the first temperature sensor 216 and the second temperature sensor 218. Other techniques for determining the change of temperatures will be apparent to those skilled in the art and are intended to fall within the scope of the present subject matter.
At step 370 of method 300, the temperature change associated with the first temperature sensor 216 is compared to the temperature change associated with the second temperature sensor 218 and controller 166 determines if either of the first temperature sensor or the second temperature sensor are malfunctioning. In comparing the temperature change associated with the first temperature sensor 216 with the temperature change associated with the second temperature sensor 218, it will be understood that the temperature changes are based on measurements using like techniques. For example, in embodiments where a plurality of temperature readings from first temperature sensor 216 and temperature sensor 218 are received and averaged, the controller 166 will compare the average temperature change associated with first temperature sensor 216 to the average temperature change associated with second temperature sensor 218. Alternatively, where an absolute difference is determined at step 360, the comparison will be between those absolute differences in temperature change.
In determining if either of the first temperature sensor 216 or second temperature sensor 218 are malfunctioning, controller 166 determines whether the temperature change of the first temperature sensor is consistent with the temperature change of the second temperature sensor. As used herein, consistency of the temperature changes is not intended to require precise equality between the temperature changes associated with first temperature sensor 216 and second temperature sensor 218. Rather, consistency is intended to be measured by the temperature trend of the temperature change.
For example, in a hot wash cycle, it would be expected for the water temperature and air temperatures to rise during the course of the wash cycle. If both the first temperature sensor 216 and the second temperature sensor 218 are working properly, both will reflect this rise in temperature. However, the air temperature will be a function of the water temperature and will necessarily lag behind. Thus, even in a perfectly operating laundry appliance, the second temperature sensor 218 may not reflect a temperature rise over exactly the same time frame that the first temperature sensor 216 registers a rise in temperature. Nor will the temperature rises be identical due to a variety of factors, including at least heat absorption by articles of laundry and other portions of the appliance and due to the imprecision of the temperature sensors themselves. Thus, the term consistency, as used herein, may be attained if the first temperature sensor 216 and the second temperature sensor 218 both register an increase in temperature over an extended period of time (e.g., 180 seconds). Consistency would likewise be achieved if both sensors registered a decrease or both registered a maintaining of temperature over time. By contrast, the temperature changes associated with first temperature sensor 216 and second temperature sensor 218 would be inconsistent if the temperature change of one of the first temperature sensor 216 or the second temperature sensor 218 has a temperature change over the extended period of time and the other does not.
If it is determined at step 370 that the temperature changes of first temperature sensor 216 and second temperature sensor 218 are consistent, the wash cycle simply continues, as shown at step 380. However, if it is determined at step 370 that the temperature changes of first temperature sensor 216 and second temperature sensor 218 are inconsistent, this is an indication that one or both of first temperature sensor 216 and second temperature sensor 218 are malfunction. Continued use of the washing machine appliance 100 may therefore lead to less effective washing cycles and a poor perception of the appliance itself. Accordingly, in the case of inconsistent temperature changes, a notification may be provided to the user that first temperature sensor 216 or second temperature sensor 218 are faulty, or that service is otherwise required. This notification may take the form of a light or other signal on control panel 160 or display 164 in certain embodiments. In alternative embodiments, the notification may take the form of an indication sent to consumer device 164. In still other embodiments, the fault may be relayed to a remote server 196, which may result in a message being delivered to the user. Alternatively, combinations of the above forms of notification may be employed. Regardless of the form of notification, the wash cycle may continue, as the fault does not present a safety issue.
It will be understood that method 300 may further include repeated checks of the temperature sensors during a given wash cycle. That is the controller 166 may be configured to repeat the steps of receiving the first temperature and the second temperature from the first temperature sensor and the second temperature sensor, determining the temperature change of the first temperature sensor and the second temperature sensor, comparing the temperature change of the first temperature sensor and the second temperature sensor, and determining if either of the first temperature sensor or the second temperature sensor is malfunctioning throughout the wash cycle. Thus, method 300 may be understood to be an iterative process.
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 languages of the claims.
