Tub structures for dishwasher appliances

Tubs for dishwasher appliances, as well as associated dishwasher appliances, are provided. A tub includes a plurality of walls defining a wash chamber. At least one of the plurality of walls includes a non-porous outer barrier, a non-porous inner barrier, and a porous media disposed between the outer barrier and the inner barrier. The porous media includes a matrix and one or more voids defined in the matrix.

FIELD OF THE INVENTION

The present disclosure relates generally to dishwasher appliances, and more particularly to tubs of dishwasher appliances which have improved internal structures.

BACKGROUND OF THE INVENTION

Modern dishwashers typically include a tub which defines a wash chamber where e.g., detergent, water, and heat can be applied to clean food or other materials from dishes and other articles being washed. Various cycles may be included as part of the overall cleaning process. For example, a typical, user-selected cleaning option may include a wash cycle and rinse cycle (referred to collectively as a wet cycle), as well as a drying cycle. A pre-wash cycle may also be included as part of the wet cycle, and may be automatic or an option for particularly soiled dishes.

The tub of a dishwasher appliance typically is surrounded by a cabinet and a door of the dishwasher appliance. Additional dishwasher components such as sump components are positioned at the bottom of and/or below the tub. Typical tubs are formed from thin sheets of stainless steel or injection molded plastic. Known tub designs, however, have a variety of disadvantages. For example, the thin sheets of material typically utilized to form a tub generally require structural reinforcement. Further, such materials provide less than desirable thermal and acoustic insulation, thus requiring that additional insulation be added to the dishwasher appliance, typically between the tub and cabinet.

Accordingly, improved dishwasher appliances are desired in the art. In particular, dishwasher appliances having improved tub structures which, for example, provide improved structural rigidity, thermal insulation and/or acoustic insulation are desired.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with one embodiment of the present disclosure, a tub for a dishwasher appliance is provided. The tub includes a plurality of walls defining a wash chamber. At least one of the plurality of walls includes a non-porous outer barrier, a non-porous inner barrier, and a porous media disposed between the outer barrier and the inner barrier. The porous media includes a matrix and one or more voids defined in the matrix.

In accordance with another embodiment of the present disclosure, a dishwasher appliance is provided. The dishwasher appliance includes a cabinet defining an interior, and a tub disposed within the interior and defining a wash chamber for the receipt of articles for cleaning The dishwasher appliance further includes a sump for collecting liquid from the chamber, and a fluid circulation conduit for circulating liquid in the tub. The tub includes a plurality of walls defining the wash chamber. At least one of the plurality of walls includes a non-porous outer barrier, a non-porous inner barrier, and a porous media disposed between the outer barrier and the inner barrier. The porous media includes a matrix and one or more voids defined in the matrix.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 2depict an exemplary domestic dishwasher appliance100that may be configured in accordance with aspects of the present disclosure. For the particular embodiment ofFIG. 1, the dishwasher appliance100includes a cabinet102that defines an interior103. A tub104is disposed in the interior103. Tub104defines a wash chamber106. Chamber106is configured for the receipt of articles for cleaning, such as dishes, cups, utensils, etc. The tub104includes a front opening, and and a door120is hinged to the tub104for movement between a normally closed vertical position (shown inFIGS. 1 and 2), wherein the wash chamber106is sealed shut for washing operation, and a horizontal open position for loading and unloading of articles from the dishwasher appliance100. Latch123is used to lock and unlock door120for access to chamber106.

Upper and lower guide rails124,126are mounted on tub sidewalls and accommodate roller-equipped rack assemblies130and132. Each of the rack assemblies130,132may be fabricated into lattice structures including a plurality of elongated members134(for clarity of illustration, not all elongated members making up assemblies130and132are shown inFIG. 2). Each rack130,132is adapted for movement between an extended loading position (not shown) in which the rack is substantially positioned outside the wash chamber106, and a retracted position (shown inFIGS. 1 and 2) in which the rack is located inside the wash chamber106. This is facilitated by rollers135and139, for example, mounted onto racks130and132, respectively. A silverware basket (not shown) may be removably attached to rack assembly132for placement of silverware, utensils, and the like, that are otherwise too small to be accommodated by the racks130,132.

The dishwasher appliance100further includes a fluid circulation system, which includes a lower spray-arm assembly144that is rotatably mounted within a lower region146of the wash chamber106and above a tub sump portion142so as to rotate in relatively close proximity to rack assembly132. A mid-level spray-arm assembly148of the fluid circulation system is located in an upper region of the wash chamber106and may be located in close proximity to upper rack130. Additionally, an upper spray assembly150of the fluid circulation system may be located above the upper rack130.

The lower and mid-level spray-arm assemblies144,148and the upper spray assembly150are fed by a fluid circulation conduit152of the fluid circulation system for circulating water and dishwasher fluid (generally referred to as liquid) in the tub104. A pump154, which may for example be located in a machinery compartment140located below the bottom sump portion142of the tub104, may flow liquid to and through the fluid circulation conduit152. Each spray-arm assembly144,148includes an arrangement of discharge ports or orifices for directing washing liquid onto dishes or other articles located in rack assemblies130and132. The arrangement of the discharge ports in spray-arm assemblies144,148provides a rotational force by virtue of washing fluid flowing through the discharge ports. The resultant rotation of the lower spray-arm assembly144provides coverage of dishes and other dishwasher contents with a washing spray.

The dishwasher100is further equipped with a controller137to regulate operation of the dishwasher100. The controller 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.

The controller137may be positioned in a variety of locations throughout dishwasher100. In the illustrated embodiment, the controller137may be located within a control panel area121of door120as shown. In such an embodiment, input/output (“I/O”) signals may be routed between the control system and various operational components of dishwasher100along wiring harnesses that may be routed through the door120. Typically, the controller137includes a user interface panel136through which a user may select various operational features and modes and monitor progress of the dishwasher100. In one embodiment, the user interface136may represent a general purpose I/O (“GPIO”) device or functional block. In one embodiment, the user interface136may include input components, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. The user interface136may include a display component, such as a digital or analog display device designed to provide operational feedback to a user. The user interface136may be in communication with the controller137via one or more signal lines or shared communication busses.

In general, dishwasher appliance100may utilize a variety of cycles to wash and, optionally, dry articles within chamber106. For example, a wet cycle is utilized to wash articles. The wet cycle may include a main wash cycle and a rinse cycle, as well as an optional pre-wash cycle. During each such cycle, water or another suitable liquid may be utilized in chamber106to interact with and clean articles therein. Such liquid may, for example, be directed into chamber106from lower and mid-level spray-arm assemblies144,148and the upper spray assembly150. The liquid may additionally mix with, for example, detergent or other various additives which are released into the chamber during various sub-cycles of the wet cycle. A drying cycle may be utilized to dry articles after washing. During a drying cycle, for example, a heating element (not shown) may heat the chamber106to facilitate drying of the articles and evaporation of liquid into gas within the chamber106. In generally, no liquid is sprayed or otherwise produced during the drying cycle.

It should be appreciated that the invention is not limited to any particular style, model, or other configuration of dishwasher, and that the embodiment depicted inFIGS. 1 and 2is for illustrative purposes only. For example, instead of the racks130,132depicted inFIG. 1, the dishwasher100may be of a known configuration that utilizes drawers that pull out from the cabinet and are accessible from the top for loading and unloading of articles. Other configurations may be used as well.

FIG. 3is a perspective view of one embodiment of a tub104for a dishwasher appliance100. As shown, the tub104includes a plurality of walls which define the wash chamber106. For example, tub104may include first and second sidewalls200,202. Second sidewall202may be spaced apart from first sidewall200along a longitudinal axis L. Tub104may further include a top wall204and a bottom wall206. The bottom wall206may be spaced apart from the top wall204along a vertical axis V. As shown, a sump passage207may be defined in the bottom wall206. The sump passage207may allow components of the sump portion142to extend through the bottom wall206. Additionally, other passages may be defined in the various walls of the tub104as required. Tub104may further include a rear wall208which extends longitudinally between the sidewalls200,202and vertically between the top wall204and bottom wall206. Additionally, tub104may define a front opening210. Specifically, the sidewalls200and202, top wall204and bottom wall206may define the front opening210, which may extend longitudinally between the sidewalls200,202and vertically between the top wall204and bottom wall206. Rear wall208may be spaced apart from the front opening210along a transverse axis T.

It should be noted that the vertical axis V, longitudinal axis L, and transverse axis T are orthogonal to each other as is generally understood.

Referring now toFIGS. 4 through 6, the present disclosure is further directed to improved wall structures for tubs104of dishwasher appliances100. Wall structures in accordance with the present disclosure advantageous improve the structural rigidity of the associated tubs104, and further provide improved acoustic and thermal insulating qualities.

FIGS. 4 through 6illustrate exemplary walls220in accordance with the present disclosure. A wall220as shown may be a sidewall200, sidewall202, top wall204, bottom wall206, rear wall208, or any other suitable wall220of a tub104for a dishwasher appliance100. As shown, one or more walls220may include a porous media which is enclosed by adjacent non-porous barriers. The porous media advantageously provides the improved structural rigidity to the tub104and may further increase the strength and strength-to-weight ratio of the tub104. The non-porous barriers may generally protect the porous media and, in some embodiments, provide a hermetic seal for the porous media.

A wall220in accordance with the present disclosure may thus include a non-porous outer barrier222and a non-porous inner barrier224. At least a first porous media226may be disposed between the outer barrier222and inner barrier224. Further, as shown, one or more non-porous intermediate barriers232may be provided, and disposed between the outer barrier222and inner barrier224. Additionally, more than one porous media may be included in a wall, with each porous media disposed between adjacent barriers. For example, in the embodiments ofFIGS. 4 and 5, the first porous media226is disposed between the outer barrier222and the intermediate barrier232, and a second porous media234is disposed between the intermediate barrier232and the inner barrier224.

A porous media226,234in accordance with the present disclosure includes a matrix242and one or more voids244defined in the matrix242. In exemplary embodiments, various pluralities of voids244are in fluid communication such that fluids can flow between the voids244.

The barriers222,224,232and porous media226,234can be formed from any suitable materials. In exemplary embodiments, the barriers222,224,232and porous media226,234of a wall220are formed from the same material, although in alternative embodiments different materials may be utilized for any of the various components, including for the barriers222,224,232versus the porous media226,234, etc. Polymers, such as nylon or acrylonitrile butadiene styrene (“ABS”), may in exemplary embodiments be utilized for one or more of the barriers222,224,232and porous media226,234. Alternatively, metals such as stainless steel may be utilized.

Notably, in exemplary embodiments, the barriers222,224,232and porous media226,234of a wall220are formed from the same material and are integral with each other. Such construction of a wall220has previously not been possible due to manufacturing restraints. However, the present inventors have advantageously utilized current advances in additive manufacturing techniques to develop exemplary embodiments of such walls220and tubs104generally in accordance with the present disclosure. While the present disclosure is not limited to the use of additive manufacturing to form such walls220and tubs104generally, additive manufacturing does provide a variety of manufacturing advantages, including ease of manufacturing, reduced cost, greater accuracy, etc.

As used herein, the terms “additively manufactured” or “additive manufacturing techniques or processes” refer generally to manufacturing processes whereing successive layers of material(s) are provided on each other to “build-up”, layer-by-layer, a three-dimensional component. The successive layers generally fuse together such as that a monolithic component is formed which may have a variety of integral sub-components. Suitable additive manufacturing techniques in accordance with the present disclosure include, for example, Fused Deposition Modeling (FDM), Selective Laser Sintering (SLS), 3D printing such as by inkjets and laserjets, Sterolithography (SLA), Direct Selective Laser Sintering (DSLS), Electron Beam Sintering (EBS), Electron Beam Melting (EBM), Laser Engineered Net Shaping (LENS), Laser Net Shape Manufacturing (LNSM) and Direct Metal Deposition (DMD).

Referring now toFIG. 6, and as discussed, in some embodiments at least two walls220may include a non-porous outer barrier222, a non-porous inner barrier224and a porous media226(as well as optional intermediate barriers232, porous media234, etc.). In exemplary embodiments as shown, the porous media226,234of these walls220may be in fluid communication. Specifically, the porous media226of neighboring and contacting walls220may be in fluid communication with each other and/or the porous media234of neighboring and contacting walls220may be in fluid communication with each other.FIG. 6illustrates an intersection of two neighboring walls220of the plurality of walls. As shown, the porous media226may extend through the intersection or otherwise be in fluid communication through the intersection such that fluid may flow between the porous media226of the neighboring walls220.

Referring still toFIG. 6, an intersection between neighboring walls220may include an intersection252between the non-porous outer barriers222of the neighboring walls220, an intersection254between the non-porous inner barriers224of the neighboring walls220, and an intersection256between the porous media226of the neighboring walls220. When utilized, intersections between intermediate barriers232and additional porous media234may additionally be defined. In exemplary embodiments, the intersections252between the non-porous outer barriers222may be hermetically sealed, and may thus prevent fluid leakage therethrough. Further, in exemplary embodiments, the intersections254between the non-porous inner barriers224may be hermetically sealed, and may thus prevent fluid leakage therethrough. Accordingly, fluid within the porous media226,232may advantageously be prevented from escaping through such intersections252,254. Such hermetic sealing may be facilitated through the integral forming of the neighboring walls, or the walls may otherwise be sealed during or after manufacturing such that a hermetic seal is provided.

Referring again toFIGS. 4 through 6, various suitable fluids may be contained within the porous media226,234of the various walls220of a tub104. For example, in some embodiments, the fluid may be a gas such as air. In some embodiments, for example, air or another suitable gas at an ambient pressure may be contained within the porous media226and/or234. In other embodiments, the voids244of porous media226and/or234may have a vacuum pressure level lower than an ambient pressure level outside of the plurality of walls220. Accordingly, air or another suitable gas at a negative pressure relative to the ambient pressure level may be contained within the porous media226and/or234.

Referring toFIG. 5, in some embodiments, one or more inlet passages260may be included in a tub104in accordance with the present disclosure. Each inlet passage260may extend through the inner barrier224of a wall220to a porous media, such as the porous media226as shown or a porous media234. The inlet passage260may allow for a fluid, such as a liquid, to be flowed into the one or more voids244of the porous media226,234of that wall220. In some embodiments, the fluid may be a liquid such as water. For example, in some embodiments, the inlet passage260is in fluid communication with the fluid circulation conduit152or other component of the fluid circulation system for selectively flowing liquid, such as water, into the one or more voids244of the porous media226and/or234.

In some exemplary embodiments, the tub104and appliance100generally may be shipped to a consumer with no liquid contained in the porous media226,234. After installation, a liquid, such as water, may be flowed through the inlet passages260to the voids244of the porous media226and/or234. The liquid may serve to weigh down the tub104and appliance100generally, thus advantageously reducing unwanted vibrations, etc., and may provide additional structural rigidity and act as additional thermal insulation and/or acoustic insulation.

In embodiments wherein multiple porous media226,234are utilized, each layer of porous media226,234may include a fluid having different characteristics or the same characteristics within the voids244thereof. For example, in some embodiments, porous media226may hold (or be configured to hold after installation) a liquid, while porous media234contains a gas at a vacuum pressure, as shown inFIG. 5