Refrigeration accumulator having a matrix wall structure

Information

  • Patent Grant
  • 6311514
  • Patent Number
    6,311,514
  • Date Filed
    Friday, April 7, 2000
    24 years ago
  • Date Issued
    Tuesday, November 6, 2001
    23 years ago
Abstract
An accumulator includes a housing having an open top end, an open bottom end, an outer wall, and an inner wall disposed within the outer wall to define an interior. The inner and outer walls are integrally interconnected by longitudinal partitions that define longitudinal channels with a downflow channel and an upflow channel positioned among the longitudinal channels. A top cover mounts to, and closes, the open top end of the housing, and has an inlet passage and an outlet passage therethrough. A refrigerant separator is positioned beneath the top cover for directing refrigerant from the inlet passage of the top cover to the interior of the housing, for venting gaseous refrigerant to the downflow passage of the housing while preventing ingress of liquid refrigerant therein, and for communicating gaseous refrigerant from the upflow passage of the housing to the outlet passage of the top cover. A cross-passage conveys gaseous refrigerant from the downflow passage of the housing to the upflow passage of the housing and includes a pickup tube for lubricating the refrigerant flowing through the cross-passage. Liquid refrigerant entering the accumulator collects in the interior of the housing and gaseous refrigerant is conveyed through an aperture in the refrigerant separator down the downflow passage, across the accumulator through the cross-passage, up the upflow passage, over the refrigerant separator, and out the outlet passage of the top cover.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to an accumulator device for use In an air-conditioning system, and more particularly to an accumulator device for use in an air-conditioning refrigeration system of a motor vehicle.




2. Description of the Prior Art




The use of accumulator devices in air-conditioning systems, particularly motor vehicle air-conditioning systems, is well known. It is also well known to use steel or aluminum in manufacturing an accumulator housing. However, it is less common to use plastic in manufacturing accumulator housings since environmental and performance requirements require use of prohibitively thick plastic walls.




In a typical air-conditioning system, the compressor receives a gaseous refrigerant from the evaporator and compresses the gaseous refrigerant, sending it under high pressure to the condenser as a superheated vapor. Since the high-pressure vapor delivered to a condenser is much hotter than the surrounding air, the heat of the high-pressure vapor is given off to the outside air flowing through the condenser fins, thereby cooling the refrigerant. As the gaseous refrigerant loses heat to the surrounding air, it condenses into a liquid refrigerant. The condensed liquid refrigerant then enters an orifice tube at which the pressurized liquid refrigerant transforms into a gaseous state thereby absorbing heat from warm air passing through the fins of the evaporator.




After the warmed liquid refrigerant changes phase to gas, it is passed from the evaporator to an accumulator. From the accumulator, the refrigerant is passed back to the compressor to start the cycle over again. However, it is very important to ensure that the refrigerant being passed back to the compressor is in a completely gaseous state. If liquid refrigerant reaches the compressor, it will clog it up. Thus, the accumulator'main purpose is to assure that only gaseous refrigerant passes to the compressor. Additionally, the accumulator injects a prescribed amount of lubricating oil into the gaseous refrigerant for lubricating the compressor. Furthermore, the accumulator can be used to make sure the oil-laden gaseous refrigerant is free of particulates that might also harm the compressor.




Accordingly, the accumulator of an air-conditioning system can be used to accomplish five functions, it (a) completely vaporizes the refrigerant, (b) removes all water vapor, (c) traps all particulates, (d) injects a lubricant into the outgoing refrigerant vapor stream, and (e) acts as a reservoir for the refrigerant when system demand is low. Typical examples of accumulators accomplishing these functions are shown in U.S. Pat. Nos. 3,798,921; 4,111,005; 4,291,548; 4,496,378; 5,052,193; and 5,282,370.




Typically, a suction accumulator consists of a liquid storage vessel in which is received a generally U-shaped tube, one end of which is connected to the outlet of the storage vessel and the other end of which is opened to the interior of the vessel. As the incoming liquid refrigerant flows into the vessel, it collects in the bottom of the interior and the gaseous components of the refrigerant are forced, due to pressure in the accumulator and the vacuum created by the compressor, through the open end of the U-shaped tube and out of the accumulator. Oil for lubricating the compressor collects in the bottom of the vessel along with any liquid refrigerant. Typically, an orifice located in a bight portion of the U-shaped tube entrains, by venturi action, a metered amount of oil into the gaseous refrigerant exiting the accumulator.




A problem with prior art accumulators is that it is necessary to introduce some type of device, such as a refrigerant separator member, to prevent substantial amounts of liquid refrigerant from exiting the accumulator or gaining access to the open end of the U-shaped tube. Thus, it is customary to employ a refrigerant separator member somewhere proximate the open inlet end of the U-shaped tube in order to prevent the liquid from entering the exit tube of the accumulator. Typically, these refrigerant separator members have a frustoconical design that serves to deflect the liquid refrigerant back down into the bottom portion of the accumulator while allowing the gaseous refrigerant to pass by.




An example of such a device includes U.S. Pat. No. 4,474,035 to Amin et al. Amin et al. disclose a domed refrigerant separator located in an upper region of an accumulator housing adjacent an accumulator inlet opening. Liquid refrigerant enters the accumulator housing through the inlet opening in the top of the housing and disperses over the dome of the refrigerant separator toward the sides of the housing. This creates vertical flow of the refrigerant down the sides of the accumulator housing. The vapor component of the refrigerant collects in the upper region of the housing beneath the refrigerant separator, near the inlet end of an outlet tube. Amin et al. disclose that an inlet end of an outlet tube is located directly below the domed refrigerant separator. Amin et al. further disclose that a leg of the outlet tube is brazed or welded in a hole in the refrigerant separator as well as to the top of the accumulator housing.




Accordingly, traditional prior art accumulator references uniformly disclose and teach the use of a refrigerant separator member. The refrigerant separator member prevents liquid refrigerant from reaching an exit tube that is partially located within the accumulator and that is used to convey the gaseous refrigerant it to the compressor. The components, such as the exit tube and the refrigerant separator member, necessary to achieve the stated functions of an accumulator, add significantly to the cost, complexity and potential problems associated with prior art accumulators.




One recent approach to solving Such problems with traditional accumulators is represented in U.S. Pat. No. 5,471,854 to DeNolf. DeNolf teaches use of an accumulator that does not have a refrigerant separator member or tubes within a housing. DeNolf discloses the accumulator as having an inner housing with standoffs disposed within an outer housing thereby defining a flow path therebetwcen. A cap seals the inner and outer housings and connects the accumulator to an air-conditioning system. A refrigerant is introduced to the inner housing and flows through an aperture in the inner housing into and through the flow path down one side of the accumulator, across the bottom of the accumulator, back up an opposite side of the accumulator, and out the accumulator via a passage in the cap.




While the DeNolf reference represents a very significant improvement over the structure of traditional accumulators, it unfortunately involves a few drawbacks. For one, the DeNolf reference involves multiple housings that must be individually formed and further processed. Additionally, a rather rigid material, Such as aluminum, must be used in order to withstand the internal forces due to pressure within the refrigeration system and the external forces imposed upon the accumulator during assembly. Therefore, cheaper and lighter weight materials such as plastic are not generally usable with such a design. Finally, the DeNolf reference does not disclose structure for shielding the aperture in the inner housing from incoming liquid refrigerant.




Thus, there remains a need for an accumulator for use in an air-conditioning system of an automotive vehicle, that is adaptable to plastic materials, is more capable and more reliable in preventing liquid refrigerant from reaching the inlet line of the compressor, and wherein the accumulator does not require the use of an exit tube such as is known in the prior art. The use of plastics and the elimination of the tube and multiple housings of the prior art would result in significant cost savings in the manufacture of the accumulator.




SUMMARY OF THE INVENTION




The present invention contemplates an accumulator design for an air-conditioning system, wherein the accumulator is adaptable to use of plastics, is efficient in its operation, includes a minimum number of parts, and is less expensive to manufacture as compared to known accumulators. To reduce the number of parts and time needed to produce the accumulator, the invention further contemplates an accumulator housing wherein the tubes and multiple housings are not required.




An accumulator includes a housing having an open top end, an outer wall, and an inner wall disposed within the outer wall such that the inner wall defines an interior of the accumulator. The inner and outer walls are integrally interconnected by longitudinal partitions that define longitudinal channels. The longitudinal partitions further define a downflow channel and an upflow channel positioned among the longitudinal channels. The housing also has an interior defined between the open top and bottom ends, inside of the inner wall. A top cover is mounted to the open top end of the housing for closing the open top end of the housing. The top cover has an inlet passage and an outlet passage therethrough. A refrigerant separator is positioned beneath the top cover for directing refrigerant from the inlet passage of the top cover through to the interior of the housing, for preventing liquid refrigerant from entering the downflow passage of the housing, and for communicating gaseous refrigerant from the upflow passage of the housing to the outlet passage of the top cover. The refrigerant separator includes an aperture for venting gaseous refrigerant from the interior of the housing to the downflow passage of the housing. A cross-passage connects the downflow passage of the housing to the upflow passage of the housing, for conveying gaseous refrigerant therebetween. The cross-passage includes a pickup tube for lubricating gaseous refrigerant flowing through the cross-passage. Liquid refrigerant entering the accumulator collects in the interior and is vented through the aperture of the refrigerant separator, down the downflow passage of the housing, across the cross-passage, Lip the upflow passage of the housing, over the refrigerant separator, and out the outlet passage of the top cover.




It is an object of the present invention to provide an accumulator that overcomes some or all of the above-mentioned problems with the prior art.




It is another object to provide an accumulator that is capable of being automatically assembled.




It is yet another object of the present invention to provide an accumulator of the type described above in which a desiccant-containing member can be mounted inside of the housing.




It is a further object of the present invention to provide an accumulator of the type described above that can be made out of a variety of materials.




It is still a further object of the present invention to provide an accumulator of the type described above that can be made out of aluminum or plastic.




It is but a further object of the present invention to provide an accumulator of the type described above that does not incorporate a J-tube located within the housing of the accumulator.




It is yet another object of the present invention to provide an accumulator of the type described above that costs less to manufacture.




The above objects and other objects, features and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in conjunction with the accompanying drawings.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a front view of a prior art accumulator;





FIG. 2

is a half cross-sectional view of an accumulator according to the preferred embodiment of the present invention;





FIG. 2A

is a top view of a bottom cover of

FIG. 2

;





FIG. 2B

is another half cross-sectional view of the accumulator of

FIG. 2

, taken 90 degrees to the cross-section thereof;





FIG. 3

is partial perspective view of an alternative housing wall, having criss-cross longitudinal partitions;





FIG. 3A

is a partial top view of an alternative housing wall, having honeycomb longitudinal partitions;





FIG. 3B

is a partial top view of a housing wall of

FIG. 2

, having triangle shaped longitudinal partitions;





FIG. 3C

is a partial top view of an alternative housing wall, having corrugated longitudinal partitions;





FIG. 4

is a bottom view of a top cover of the accumulator of

FIG. 2

;





FIG. 5

is a perspective view of a refrigerant separator of the accumulator of

FIG. 2

;





FIG. 6

is a top view of the housing and refrigerant separator of

FIG. 2

, with the top cover removed;





FIG. 7

is a partial cross-sectional view of a lower portion of an accumulator according to an alternative embodiment of the present invention;





FIG. 8

is a partial cutaway perspective view of the lower portion of an accumulator according to another alternative embodiment;





FIG. 8A

is right side cross-sectional view of the accumulator of

FIG. 8

;





FIG. 9

is a partial cutaway perspective view of the lower portion of another alternative embodiment of the present invention; and





FIG. 10

is a partial cutaway perspective view of the lower portion of the preferred embodiment of the present invention.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




In general, and in view of this disclosure, those skilled in the art will appreciate that an accumulator according to the present invention may be used in other types of air-conditioning systems and at various locations within such systems.




Referring now specifically to the structure of the present invention as shown in the Figures, there is shown in

FIG. 1

an aluminum prior art accumulator


10


P having a cylindrical housing


20


P (shown in phantom line), a top cover


60


P, a refrigerant separator


70


P, and a J-tube


96


P with a desiccant pack


12


P strapped thereto. The accumulator


10


P is not easily assembled automatically since the J-tube


96


P must be bent and positioned in place to the top cover


60


P by hand. Additionally, the desiccant pack


12


P must be strapped in place to the J-tube


96


P by hand.




As shown in

FIG. 2

, an accumulator


10


according to the preferred embodiment of the present invention includes a housing


20


preferably in the form of a hollow cylinder and having an open top end


22


and an open bottom end


24


. The housing


20


also has an outer wall


26


and an inner wall


28


disposed within the outer wall


26


. At the open bottom end


24


, a U-shaped canopy


30


spans radially across opposite sides of the inner wall


28


. Reference to

FIG. 10

will reveal the true shape of the U-shaped canopy


30


.




As shown in

FIG. 3

, the inner wall


28


is integrally interconnected to the outer wall


26


by integral longitudinal partitions


32


that define longitudinal passages


33


. Such matrix-walled structure is common in the manufacture of plastic well pipe and plastic underground pipelines, as evidenced by U.S. Pat. Nos. 4,215,727 and 4,341,392. Alternatively, integral longitudinal partitions


32


A,


32


B,


32


C may take the form of honeycomb, opposed triangle, or corrugated structure as shown in

FIGS. 3A

,


3


B, and


3


C respectively. It is contemplated that other easily formed structures could be substituted for the examples shown in

FIGS. 3 through 3C

.




Referring again to

FIG. 2

, the inner and outer walls


28


and


26


extend longitudinally between the open top and bottom ends


22


and


24


. In addition, a downflow passage


34


and an upflow passage


36


are disposed between the inner and outer walls


28


and


26


. It is possible to construct the housing


20


out of any material suitable for use as an accumulator device of an air-conditioning system, such as ferrous and non-ferrous metals or composites. The housing


20


according to the present invention, however, is preferably manufactured from a polymeric material having sufficient strength to withstand the forces experienced during operation. The housing


20


may be manufactured using any known method but is preferably extruded, injection molded, or made by a combination of the two. Accordingly, the U-shaped canopy


30


may be overmolded separately into an extrusion to form the housing


20


. In other words, an extruded portion of the housing


20


may be cut to length from a continuous extrusion and be placed in a molding press where the U-shaped canopy


30


is then molded in position to bottom of the housing


20


, as is known in the art of plastics molding.




Still referring to

FIG. 2

, a bottom cover


40


is preferably molded from plastic and is used to close the open bottom end


24


of the housing


20


. The bottom cover


40


includes a pickup tube


46


molded therein. As shown in

FIG. 2A

, the bottom cover


40


includes an integral U-shaped trough


42


that is molded radially across the bottom cover


40


. The pickup tube


46


is mounted transverse to and through the U-shaped trough


42


. The pickup tube


46


has a hole


48


that communicates with the inside of the U-shaped trough


42


, and further has opposite open ends


50


that communicate with the hole


48


. Each opposite open end


50


of the pickup tube


46


opens into separate reservoirs


44


of the bottom cover


40


. The U-shaped trough


42


sealingly fits within the U-shaped canopy


30


of the housing


20


to form a cross-passage


52


.




The cross-passage


52


, as shown in

FIG. 2

, communicates the downflow passage


34


with the upflow passage


36


. Also shown in

FIG. 10

, the bottom cover


40


includes the U-shaped trough


42


that fits within the U-shaped canopy


30


of the housing


20


to produce a refrigerant-tight seal and define the cross-passage


52


. It is possible to connect the U-shaped trough


42


and the U-shaped canopy


30


in any manner as long as the cross-passage


52


thus formed functions to convey gaseous refrigerant across the accumulator


10


between the bottom cover


40


and housing


20


, while preventing liquid refrigerant from entering the cross-passage


52


. In view of this disclosure, those skilled in the art will appreciate that the bottom cover


40


could be threaded to the housing


20


, or snapped to the housing


20


with integral fasteners. Preferably, however, the bottom cover


40


is bonded or ultrasonically welded to the housing


20


.




Referring again to

FIG. 2

, a top cover


60


closes the open top end


22


of the housing


20


and a refrigerant separator


70


is mounted therebetween. An interior


38


of the accumulator


10


, having a circular cross section, is defined inside the inner, wall


28


between the top and bottom covers


60


and


40


, and beneath the refrigerant separator


70


. The top cover


60


includes an inlet passage


62


for introducing refrigerant to an inlet portion


72


of the refrigerant separator


70


and into the interior


38


of the accumulator


10


. As shown in

FIG. 4

, the top cover


60


includes an arcuate undersurface


64


and has an outlet passage


66


positioned next to the inlet passage


62


. Referring again to

FIG. 2

, the outlet passage


66


communicates with the upflow passage


36


via a path defined between a gas outlet portion


74


of the refrigerant separator


70


and the top cover


60


. In view of this disclosure, those skilled in the art will appreciate that the top cover


60


could be snapped to the housing


20


with integral fasteners, or could be ultrasonically welded to the housing


20


. Preferably, however, the top cover


60


is threaded to the housing


20


, to allow the accumulator


10


to be readily serviceable.




As shown in

FIG. 5

, the refrigerant separator


70


is preferably molded from plastic, is convex in shape, and promotes separation of the refrigerant entering the accumulator


10


into separate liquid and gaseous components. The refrigerant separator


70


includes the liquid inlet portion


72


, a gas aperture portion


76


, and the gas outlet portion


74


, that are all separated from one another by partitions


78


. As shown in

FIG. 2

, a top surface


80


of the partitions


78


seals against the arcuate undersurface


64


of the top cover


60


so as to fluidly isolate the inlet portion


72


, gas aperture portion


76


, and gas outlet portion


74


.




Still referring to

FIG. 2

, a desiccant pack


90


of any known shape and size is inserted in the interior


38


of the housing


20


. The desiccant pack


90


is provided to help remove any moisture from the refrigerant that may be harmful to the compressor. Preferably, the desiccant pack


90


is a puck-shaped member that is easily inserted into the interior


38


of the housing


20


. In view of this disclosure, those skilled in the art will appreciate that the desiccant contained within the accumulator


10


could include either a pellet or a porous cake form of desiccant, or any other type of desiccant suitable for use in an accumulator device. Preferably, the desiccant pack


90


is positioned within the housing


20


above the ambient liquid refrigerant level. This will assure that the desiccant will be more efficiently used, as it will not be submerged within the liquid refrigerant and lubricating oil. Any known method of positioning the desiccant pack


90


within the housing


20


may be used, such as an interference fit as shown in

FIG. 2

, or using suitable locating features.




An accumulator


310


according to an alternative embodiment of the present invention is shown in FIG.


7


. Here, the gaseous refrigerant flows from a downflow passage


334


of a housing


320


into a cross-passage


352


that is defined by a bottom surface


330


A of a cup


330


and an upper surface


354


of a bottom cover


340


. The cup


330


is preferably molded from plastic and is pressed into an interior


338


of the housing


320


to form a fluid-tight fit with the housing


320


. A hole


330


B is formed into the bottom surface


330


A of the cup


330


to allow oil to be metered into the crosspassage


352


.




A method of manufacturing the accumulator


310


according to the alternative embodiment of

FIG. 7

involves the following steps. The housing


320


, having the top end


322


and bottom end


324


, is preferably parted from a continuous extrusion having a matrix cross section as described previously. The top cover (not shown), refrigerant separator (not shown), cup


330


, and bottom cover


340


are molded, preferably using an injection molding process. The bottom cover


340


is then secured to the bottom end


324


of the housing


320


. The cup


330


is pressed into the top end


322


of the housing


320


and is located inside of the housing


320


until it bottoms out against the bottom cover


340


. The desiccant pack (not shown) is provided and assembled into the housing


320


. The refrigerant separator (not shown) is installed to the top end


322


of the housing


320


and the top cover (not shown) is fastened to the top end


322


of the housing


320


over the refrigerant separator.




A method of manufacturing the accumulator


10


according to the preferred embodiment of

FIG. 2

involves the following steps. Molding the housing


20


having the top end


22


and bottom end


24


, and similarly molding the top cover


60


, refrigerant separator


70


, and bottom cover


40


. The bottom cover


40


is secured to the bottom end


24


of the housing


20


. A desiccant pack


90


is provided and is assembled into the housing


20


. The refrigerant separator


70


is installed to the top end


22


of the housing


20


, and the top cover


40


is fastened to the top end


22


of the housing


20


.




Referring now to the operation of the present invention and specifically to

FIG. 2B

, the accumulator


10


performs as follows. Liquid refrigerant enters the accumulator


10


through the inlet passage


62


of the top cover


60


and flows over the liquid inlet portion


72


of the refrigerant separator


70


. Arrows


72


A in

FIG. 6

indicate the flow path of the refrigerant over the liquid inlet portion


72


of the refrigerant separator


70


. As indicated in

FIGS. 2B and 6

, the refrigerant impinges upon the liquid inlet portion


72


and flows radially outward until it reaches a gap


82


defined between the periphery of the liquid inlet portion


72


and the inner wall


28


of the housing


20


. At that point the refrigerant flows downward into the housing


20


.




Referring again to

FIG. 2

, the refrigerant flows down into the interior


38


of the housing


20


and through the desiccant pack


90


, as indicated by arrows


38


D. to The desiccant pack


90


thereby removes moisture from the liquid refrigerant to protect the compressor. Thus, the gaseous refrigerant is collected in the interior


38


of the accumulator


10


and is forced, under pressure resident in the air-conditioning system, to flow through the gas aperture portion


76


of the refrigerant separator


70


, as indicated by arrows


38


U. The gascous refrigerant is forced to flow into and down the downflow passage


34


of the housing


20


, as indicated by arrow


34


D.

FIG. 6

illustrates the gaseous refrigerant, as indicated by the arrows


38


U, flowing up through the gas aperture portion


76


outwardly across the refrigerant separator


70


and down into the downflow passage


34


of the housing


20


. The partition


78


separates the gas aperture portion


76


from the inlet portion


72


.




Referring again to

FIG. 2

, the refrigerant flows from the downflow passage


34


into the cross-passage


52


, as indicated by arrow


52


A. As shown in partial cross-sectional view in

FIG. 10

, the U-shaped trough


42


of the bottom cover


40


fits into the U-shaped canopy


30


of the housing


20


to define the cross-passage


52


. The cross-passage


52


is isolated from the rest of the interior


38


of the accumulator


10


except via the hole


48


in the pick-up tube


46


. Oil resident in the refrigerant flowing through the air-conditioning system will collect in the bottom of the accumulator


10


. Vacuum is pulled through the pick-up tube


46


as gaseous refrigerant flows through the cross-passage


52


and past the pick-up tube


46


. This induces the oil that is resident at the bottom of the interior


38


of the housing


20


to be metered to the center of the pickup tube


46


through the open ends


50


of the pick-up tube and out the hole


48


into the gaseous refrigerant. A metered amount of oil is pulled through the pickup tube


46


so that a controlled amount of oil is returned to the gaseous circuit of the air-conditioning system. This oil helps to keep the compressor lubricated to ensure proper working order.





FIGS. 8

,


8


A, and


9


illustrate alternative embodiments of pick-up tubes


146


and


246


mounted within a bottom cover


140


and


240


, respectively.

FIG. 8

shows a partial view of an accumulator


110


having a pick-up tube


146


molded into a U-shaped trough


142


of the bottom cover


140


so as to communicate a cross-passage


152


with an interior


138


of the accumulator


110


. The bottom cover


140


includes a raised and sloped surface


141


for draining oil to the side of the accumulator


110


where the pick-up tube


146


is located. The pick-up tube is located to position an open end


150


at the bottom of the inside of the accumulator


110


where the lubricant settles out of the refrigerant.

FIG. 9

illustrates a partial view of an accumulator


210


having a macaroni-shaped pick-up tube


246


having open ends


250


that communicate with an integral stem portion


248


that communicates with a cross-passage


252


.




Referring again to

FIG. 2

, the gaseous refrigerant flows from the cross-passage


52


into and up the upflow passage


36


, as indicated by arrow


36


U. Finally, the gaseous refrigerant exits the accumulator


10


by flowing from the upflow passage


36


, across the outlet portion


74


of the refrigerant separator


70


and out the outlet passage


66


of the top cover


60


.




From the above, it can be appreciated that a significant advantage of the present invention is that an accumulator can be manufactured from lightweight, inexpensive plastic components that may be automatically assembled in order to reduce weight and cost.




Another advantage is that in one alternative embodiment the housing may be extruded for purposes of significant cost savings.




Yet another advantage is that the accumulator components may have integral features such as threads and other fastening devices molded integrally therein without any need for machining.




Still another advantage is that the accumulator is rebuildable, involving removal of the top cover followed by removal of the spent or contaminated desiccant pack, followed by cleaning of the interior, followed by insertion of a new desiccant pack, and fastening of the top cover back on the housing.




An additional advantage is that the matrix wall structure of the housing lends itself to improved strength characteristics and improved insulating properties of the accumulator for better overall system efficiency.




While the present invention has been described in terms of a preferred embodiment, it is apparent that other forms could be adopted by one skilled in the art. The accumulator according to the present invention allows for significant changes in the dimensions of the accumulator such that it is possible to have accumulators of different dimensions, shapes, and sizes utilizing the invention described herein. Additionally, it should be obvious that the exterior structure can be modified by one skilled in the art without departing from the invention as disclosed herein. Moreover, a closed bottom housing could be used, and the refrigerant separator could be made integral with the top cover for reduced part count. It would also be possible to reverse the structure of the accumulator to achieve the same flow path described herein. Accordingly, the scope of the present invention is to be limited only by the following claims.



Claims
  • 1. An accumulator comprising:a housing having an open top end, an outer wall, and an inner wall disposed within said outer wall, said inner and outer walls being integrally interconnected by a plurality of longitudinal partitions defining a plurality of longitudinal channels, said plurality of longitudinal partitions further defining a downflow passage and an upflow passage positioned among said plurality of longitudinal channels, said housing further having an interior defined inside of said inner wall; a top cover mounted to said open top end of said housing for closing said open top end of said housing, said top cover having an inlet passage and an outlet passage therethrough; directing means positioned beneath said top cover for directing refrigerant from said inlet passage of said top cover through to said interior of said housing, said directing means preventing liquid refrigerant from entering said downflow passage of said housing and communicating gaseous refrigerant from said upflow passage of said housing to said outlet passage of said top cover; venting means positioned beneath said top cover for venting gaseous refrigerant from said interior of said housing to said downflow passage of said housing; and conveying means interposed said downflow passage and said upflow passage of said housing for conveying gaseous refrigerant from said downflow passage of said housing across said accumulator to said upflow passage of said housing, said conveying means including pickup means for lubricating gaseous refrigerant flowing through said conveying means; whereby refrigerant entering said accumulator collects in said interior of said housing and is conveyed through said venting means, down said downflow passage of said housing, across said conveying means, up said upflow passage of said housing, over said directing means, and out said outlet passage of said top cover.
  • 2. The accumulator as claimed in claim 1, wherein said plurality of longitudinal partitions comprises a honeycomb matrix structure.
  • 3. The accumulator as claimed in claim 1, wherein said plurality of longitudinal partitions comprises a criss-cross matrix structure.
  • 4. The accumulator as claimed in claim 1, wherein said plurality of longitudinal partitions comprises a corrugated matrix structure.
  • 5. The accumulator as claimed in claim 1, further comprising:a desiccant member disposed within said interior of said housing.
  • 6. The accumulator as claimed in claim 1, wherein said directing means comprises a refrigerant separator separate from said top cover.
  • 7. The accumulator as claimed in claim 1, further comprising a bottom cover mounted to said housing, said bottom cover having a trough portion thereacross.
  • 8. The accumulator as claimed in claim 7, wherein said housing further includes a canopy portion molded thereacross.
  • 9. The accumulator as claimed in claim 8, wherein said conveying means comprises said trough portion of said bottom cover fluid-tightly interlocked within said canopy portion of said housing.
  • 10. An accumulator for a refrigeration system, said accumulator comprising:a housing having an open top end and an open bottom end opposite said open top end, said housing further having an outer wall and an inner wall disposed within said outer wall, said inner and outlet walls extending longitudinally between said open top and bottom ends, said inner and outer walls being integrally interconnected by a plurality of longitudinal partitions, said plurality of longitudinal partitions defining a plurality of longitudinal channels extending between said open top and bottom ends, said plurality of longitudinal partitions further defining a downflow channel and an upflow channel positioned among said plurality of longitudinal channels, said housing further having an interior defined inside of said inner wall; a top cover mounted to said open top end of said housing for closing said open top end of said housing, said top cover having an inlet passage and an outlet passage therethrough; a refrigerant separator positioned between said top cover and said housing, said refrigerant separator including refrigerant receiving means for directing refrigerant from said inlet passage of said top cover through to said interior of said housing, said refrigerant separator further including gas outlet means for communicating gaseous refrigerant from said upflow channel of said housing to said outlet passage of said top cover; venting means positioned beneath said top cover for venting gaseous refrigerant from said interior of said housing to said downflow channel of said housing; and a bottom cover mounted to said open bottom end of said housing for closing said open bottom end of said housing, said bottom cover including conveying means for conveying gaseous refrigerant from said downflow channel of said housing across said accumulator to said upflow channel of said housing, said bottom cover further including pickup means for lubricating gaseous refrigerant flowing through said conveying means; whereby refrigerant entering said accumulator collects in said interior of said housing and gaseous refrigerant is vented through said venting means, down said downflow channel of said housing, across said conveying means of said bottom cover, LIP said upflow channel of said housing, over said gas outlet means of said refrigerant separator, and out said outlet passage of said top cover.
  • 11. The accumulator as claimed in claim 10, wherein said plurality of longitudinal partitions comprises a honeycomb matrix structure.
  • 12. The accumulator as claimed in claim 10, wherein said plurality of longitudinal partitions comprises a crisscross matrix structure.
  • 13. The accumulator as claimed in claim 10, wherein said plurality of longitudinal partitions comprises a corrugated matrix structure.
  • 14. The accumulator as claimed in claim 10, further comprising a cup pressed into said interior of said housing and having a bottom surface located against said bottom cover.
  • 15. The accumulator as claimed in claim 14, wherein said conveying means of said bottom cover comprises a trough portion scaled against said bottom surface of said cup to seal said conveying means.
  • 16. A plastic accumulator for use in an automotive air-conditioning system, said plastic accumulator comprising:a housing having an open top end and an open bottom end opposite said open top end, said housing further having an outer wall and an inner wall disposed within said outer wall, said inner and outer walls extending longitudinally between said open top and bottom ends, said inner and outer walls being integrally interconnected by a plurality of longitudinal partitions, said plurality of longitudinal partitions defining a plurality of longitudinal channels extending between said open top and bottom ends, said plurality of longitudinal partitions further defining a downflow channel and an upflow channel positioned among said plurality of longitudinal channels, said housing further having an interior defined inside of said inner wall, said housing further having a canopy molded across the bottom of said housing for conveying gaseous refrigerant thereacross; a top cover mounted to said open top end of said housing for closing said open top end of said housing, said top cover having an inlet passage and an outlet passage each positioned longitudinally therethrough; a refrigerant separator mounted between said top cover and said open top end of said housing, said refrigerant separator including a refrigerant inlet portion for directing incoming refrigerant from said inlet passage of said top cover through to said interior of said housing, said refrigerant separator further including a gas aperture portion for venting gaseous refrigerant from said interior of said housing into said downflow channel of said housing, said refrigerant separator further including a gas outlet portion for communicating lubricated gaseous refrigerant from said upflow channel of said housing to said outlet passage of said top cover; and a bottom cover mounted to said open bottom end of said housing for closing said open bottom end of said housing, said bottom cover including, a trough interlocking with said canopy of said housing to define a cross-passage for conveying gaseous refrigerant from said downflow channel of said housing to said upflow channel of said housing, said bottom cover further including pickup means for lubricating gaseous refrigerant flowing through said trough; whereby refrigerant enters said inlet passage of said top cover and flows down said refrigerant inlet portion of said refrigerant separator, separates into liquid and gaseous refrigerant, and collects in said interior of said housing, such that gaseous refrigerant rises within said interior and is vented through said gas aperture portion of said refrigerant separator into and down said downflow channel of said housing into said cross-passage, said gaseous refrigerant being lubricated by oil resident in said liquid refrigerant through said pickup means of said bottom cover and flowing into and up said upflow channel of said housing, over said gas outlet portion of said refrigerant separator, and out said outlet passage of said top cover.
  • 17. A method for manufacturing an accumulator of a refrigeration system, said method comprising the steps of:molding a matrix-walled housing having a top end and a bottom end; molding a top cover, a refrigerant separator, and a bottom cover; providing a desiccant pack; securing said bottom cover to said bottom end of said housing; assembling said desiccant pack into said matrix-walled housing; installing said refrigerant separator to said top end of said matrix-walled housing; and fastening said top cover to said top end of said matrix-walled housing.
  • 18. A method of manufacturing an accumulator for a refrigeration system, said method comprising the steps of:extruding a matrix-walled cylinder; parting said matrix-walled cylinder into a matrix-walled housing having a top end and a bottom end; molding a top cover, a refrigerant separator, a cup, and a bottom cover; providing a desiccant pack; securing said bottom cover to said bottom end of said matrixwalled housing; pressing said cup into said top end of said matrix-walled housing and locating said cup inside of said housing against said bottom cover; assembling said desiccant pack into said matrix-walled housing; installing said refrigerant separator to said top end of said matrix-walled housing; and fastening said top cover to said top end of said housing.
  • 19. An accumulator for a refrigerant system comprising a dual-walled housing that defines therebetween a plurality of upward and downward flow passages of refrigerant and a conveying means interposed said downward flow passage and said upward flow passage of said housing for conveying gaseous refrigerant from said downward flow passage of said housing across said accumulator to said upward flow passage of said housing, said conveying means including a pickup means for lubricating said gaseous refrigerant flowing through said conveying means.
  • 20. An accumulator comprising:a housing having an outer wall and an inner wall disposed within said outer wall, said inner and outer walls defining a downflow passage and an upflow passage; conveying means interposed said downflow passage and said upflow passage of said housing for conveying gaseous refrigerant from said downflow passage of said housing across said accumulator to said upflow passage of said housing, said conveying means including pickup means for lubricating gaseous refrigerant flowing through said conveying means; whereby refrigerant is conveyed down said downflow passage of said housing, across said conveying means, and up said upflow passage of said housing.
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