Heat Exchanger Header and Related Methods and Apparatuses
A heat exchanger (such as a radiator) that provides for a consistent tank-to-header joint location. The header generally includes a drafted wall that is movable adjacent to or within a tank and may include a curved fillet to maintain header alignment.
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The present application is a continuation of copending U.S. patent application Ser. No. 12/779,948, filed May 13, 2010, which is herein incorporated by reference in its entirety.
BACKGROUND1. Field of the Disclosure
The present disclosure generally relates to the field of heat exchangers including aluminum heat exchangers used to cool internal combustion engines.
2. Brief Description of Related Art
Heat exchangers are used to transfer thermal energy from one medium to another. For example, in an internal combustion engine cooling application, heat is transferred from the internal combustion engine to the cooling fluid and the cooling fluid is itself cooled as its heat is transferred to the atmosphere when the coolant flows through a radiator. The coolant flow to and from the radiator may be pumped, and a fan may be provided in the proximity of the radiator to blow air through the radiator. In any event, the coolant flow and corresponding cooling process continues during operation of the internal combustion engine, thereby maintaining the operating temperature of the internal combustion engine within acceptable limits and preventing the engine from overheating.
At present, aluminum radiators are less expensive to manufacture in high volumes than copper or brass radiators, but tend to be less durable. A typical heat exchanger or radiator includes a manifold assembly that conducts fluid flow through a plurality of flow tubes or exposed pipes (often with fins or other means for cooling increasing surface area) to reduce the operating temperature of the internal combustion engine. A manifold assembly typically includes a tank and a header joined together. Furthermore, current aluminum compact heat exchanger designs that use aluminum tanks either require the use of aluminum sidebrackets or secondary machining operations to use steel sidebrackets. The aluminum sidebrackets furthermore tend to lack the strength and cost advantages of the steel sidebrackets that are commonly used on copper and brass radiators.
More particularly, current aluminum compact heat exchanger designs utilize a variety of tanks—plastic tanks, formed tanks, fabricated tanks, or cast tanks. Plastic tanks are mainly used for mass production, but may not be cost effective for production levels below about 100,000 units per year. A formed tank, on the other hand, does not provide for ready assembly to the sidebrackets. Therefore, sidebrackets are generally welded or brazed to the core or the tank and, hence, are often made of aluminum, which is more expensive and weaker than steel. Fabricated tanks may not be cost effective for production quantities over about 500 units per year.
However, current cast tank designs fail in creating an interchangeable tank that has a consistent tank-to-header seam location whenever such a tank is mounted on a header. One reason for such inconsistent tank-to-header seam location is the inconsistent core height growth during the core baking process (i.e., during the fin-to-tube and tube-to-header brazing process). This inconsistent tank-to-header seam location results in variations in tank-to-header welding locations for each tank-header pair and, hence, makes it difficult to use robotic welding to attach the tanks to the headers. Misaligned or improperly seated tanks, furthermore, are undesirable because they can result in leaks after the tank is welded to the header.
Even in the case where aluminum sidebrackets are used, problems could arise when such sidebrackets are welded to the core or tanks of the heat exchanger. Such welded sidebrackets may fail to accommodate thermal expansions (of the core or the tanks) that occur, for example, during welding or brazing or even under normal operating conditions. When no adequate means are provided to accommodate thermally expanding metals, damage to the core may result in the case where such welded aluminum sidebrackets are utilized.
Therefore, it is desirable to provide an all aluminum (or aluminum alloy) industrial heat exchanger (i.e., radiator) that provides consistency in tank-to-header joint locations to better allow for the use of robotic welding to attach tanks to headers.
It is also desirable that a heat exchanger include a cast tank manufactured from aluminum or aluminum alloy and be suitable for robotic welding without the need for machining the tank.
It is further desirable to devise a sidebracket mounting mechanism for a radiator that permits the use of stronger steel sidebrackets on an aluminum core, while allowing for thermal expansion of the core without the need for machining the tank.
SUMMARYIn one embodiment, the present disclosure relates to a cast tank to be used as part of a heat exchanger, and a method of forming such a cast tank. The cast tank comprises an elongate aluminum housing having a substantially U-shaped cross section. The housing includes: a pair of longer side panels having a length and a pair of ends, wherein each longer side panel has a first outer surface and a first inner surface; a top panel; a pair of shorter side panels having a length that is shorter than the length of the longer side panels and a pair of ends wherein each shorter side panel has a second outer surface and a second inner surface and each end of each shorter side panel meets an end of one of the longer side panels forming a juncture; and an indentation at each end of the top panel (e.g., at the juncture of the pair of longer side panels and the pair of shorter side panels). In one embodiment, the indentation may be approximately T-shaped. In the cast tank, portions of each first inner surface and each second inner surface are configured to be mounted on a header of a core in the aluminum heat exchanger so as to enable welding of the cast tank onto the core.
In another embodiment, the present disclosure relates to a header to be used as part of a core of a heat exchanger, and a method of forming such a header. The header comprises: a base portion including a plurality of apertures therein for receiving fluid-carrying tubes of the heat exchanger therethrough; a drafted wall circumferentially surrounding the base portion and slanted to the plane thereof; and a curved fillet linking the base portion to the drafted wall and providing alignment support during welding of a tank onto the core. The drafted wall provides an attachment surface for welding the tank onto the core.
In a further embodiment, the present disclosure relates to a core of a heat exchanger. The core comprises: a plurality of fluid-carrying tubes; a plurality of fins interleaved with the plurality of fluid-carrying tubes, wherein a set of fins from the plurality of fins is disposed along a first pair of opposite sides of the core; and a pair of headers, wherein each header in the pair of headers is disposed over the plurality of fluid-carrying tubes along a corresponding one of a second pair of opposite sides of the core. Each header is configured as provided in the preceding paragraph.
In a still further embodiment, the present disclosure relates to an aluminum heat exchanger that comprises an aluminum core and a pair of cast tanks as provided in the preceding paragraphs. The heat exchanger further includes a pair of steel sidebrackets for strength and support. A method of obtaining and assembling various parts of the heat exchanger is also contemplated according to one embodiment of the present disclosure.
In a still further embodiment, the present disclosure relates to an all-aluminum (or aluminum alloy) industrial heat exchanger (or radiator) that provides consistency in tank-to-header joint locations to allow use of robotic welding of tanks to headers. A header design that includes the combination of a curved fillet and a drafted wall facilitates easy insertion of the radiator tank onto the core of the radiator and allows for different vertical core growth during baking of the core. The tanks may be made by casting, so that they do not require machining. The inner surface of the aluminum cast tank is welded onto the header and is configured to match in geometry with that of the drafted wall of the header. Alternately, the tanks may be may be made of plastic and may, for example, be molded.
Each tank may include suitably-shaped indentations (e.g., approximately sideways T-shaped indentations in an embodiment) to facilitate linking the tanks to sidebrackets using sidebracket mounts (or isolators). For example, the indentations may be located at the four corners of the cast tank, as is illustrated in
Sidebrackets may be captured by attaching nuts to the threaded inserts of the sidebracket mounts, without requiring any machining, welding or brazing. The sidebracket mounts or isolators thus allow for flexible mounting of sidebrackets, to accommodate thermal expansion of the core without causing damage to the core.
In a still further embodiment, a heat exchanger assembly includes: a tank having at least two indentations; and one or more isolators, each isolator having a base at least partially disposed in one of the indentations and a coupler extending from the base for coupling the tank to at least one other component of the heat exchanger.
In a still further embodiment, a tank to be used as part of a heat exchanger includes an elongate housing having a substantially U-shaped cross section, wherein the elongate housing includes: a pair of longer side panels, wherein each longer side panel has a first outer surface and a first inner surface; a top panel; a pair of shorter side panels, wherein each shorter side panel has a second outer surface and a second inner surface; and at least two indentations, each indentation in at least one of said pair of longer side panels, said top panel, and said pair of shorter side panels.
Other embodiments, which may include one or more parts of the aforementioned method or systems or other parts, are also contemplated, and may thus have a broader or different scope than the aforementioned method and systems. Thus, the embodiments in this Summary of the Invention are merely examples, and are not intended to limit or define the scope of the invention or claims.
For the present disclosure to be easily understood and readily practiced, the present disclosure will now be described for purposes of illustration and not limitation, in connection with the following figures, wherein:
The accompanying figures and the description that follows set forth the present disclosure in embodiments of the present disclosure. However, it is contemplated that persons generally familiar with mechanical designs, and more particularly with designs of industrial heat exchangers, will be able to apply the teachings of the present disclosure in other contexts (e.g., for automotive radiators) by modification of certain details. Accordingly, the figures and description are not to be taken as restrictive of the scope of the present disclosure, but are to be understood as broad and general teachings. In the discussion herein, when any numerical value is referenced, such value is understood to be a practically-feasible design approximation taking into account variances that may be introduced by such mechanical operations as machining, tooling, drilling, casting, etc.
It is observed at the outset that the directional terms such as “top,” “bottom,” “right,” “left,” “horizontal,” “vertical,” “upper,” “lower,” etc., and derivatives thereof are used herein for illustrative purpose only to facilitate description and understanding of relative positions of various mechanical components or parts constituting the aluminum heat exchanger according to the teachings of the present disclosure. Hence, such terms and derivatives thereof shall relate to the present disclosure as it is oriented in the drawing figures provided herein.
It is further observed here that the mechanical structures, components, assemblies, or engineering drawings thereof illustrated in various figures in the instant application are not drawn to scale, but are rather illustrated for the convenience of understanding various design aspects of an aluminum heat exchanger according to the teachings of the present disclosure. Additionally, the terms “heat exchanger” and “radiator” are used interchangeably herein to refer to a cooling mechanism used, for example, in an industrial internal combustion (IC) engine. It is noted here that although the discussion below primarily refers to industrial heat exchangers for internal combustion engines, various heat exchanger designs discussed herein may be equally used in automotive applications (e.g., as car radiators) and also with non-engine coolers such as, for example, hydraulic oil coolers, transmission oil coolers, charge-air coolers, etc., used in various industrial applications (e.g., oil coolers used to cool hydraulic oil in a tractor or charge-air coolers used to cool turbo-charged air for a turbo charged internal combustion engine). Also, the term “aluminum” in the discussion below is used for the sake of convenience only; it may be construed to include a pure aluminum material or an aluminum alloy material.
Each cast tank 20, 22 may be made of aluminum or aluminum alloy material. Because tanks 20, 22 are cast around an inner core, the raw (not machined) inside surfaces will have a tighter dimensional tolerance and, hence, a tank 20, 22 will be more easily welded to the core 11 using this surface than either the raw outside or raw bottom surfaces. Each aluminum housing 20, 22 further includes a top panel 21A and a side 21B-21D that may include a pair of longer side panels 21B and a pair of shorter side panels 21C-21D, the side 21B-21D terminating at a rim 23. For ease of illustration, the top panel 21A, one longer side panel 21B, and two shorter side panels 21C-21D of the cast tank 20 are identified in
For example, in an embodiment, each cast tank 20, 22 may include a suitably-shaped indentation at each end of the top panel (at the juncture of the pair of longer side panels 21B and shorter side panels 21C-21D). In the embodiment of
Each indentation (e.g., one or more of 32A-32F) may be located otherwise as desired. For example, one or more indentations may be located in the top panel (e.g., 21A), one or both longer side panels (e.g., one or both of 21B), or one or both shorter side panels (e.g., one or both of 21C-21D). In various embodiments, one or more indentations may be located in at least one of the pair of longer side panels, the top panel, and the pair of shorter side panels, and thus in any combination of that top panel, one or both longer side panels, and one or both shorter side panels. For example, in one such embodiment, one or more indentations may be formed in the top panel. In another embodiment, one or more indentations may be formed in a top panel and further in one or both a longer side panel and shorter side panel. For example, as described herein, each of four indentations may be formed at a different one of the four corners of the top panel, and thus at the juncture of the top panel, a longer side panel, and a shorter side panel.
In the embodiment of
In one embodiment, all the holes (24A-24B, 25A-25B, and 28) and all indentations (e.g., T-shaped indentations 32A-32F) are cast into the aluminum housing of their respective cast tank 20, 22 along with the housing structure (including its top panel 21A, longer side panels 21B, and shorter side panels 21C-21D) so as to form a unitary structure for the cast tank 20, 22 as can be seen from various figures herein, including
In one embodiment of the present disclosure, the need to adequately accommodate for thermal expansion of the core 11 and the need to preferably avoid secondary machining or welding/brazing operations may be satisfied by using a flexible sidebracket mounting mechanism that includes a plurality of sidebracket mounts or isolators, some of which are identified as parts 46A-46G in
The sidebracket mounts (e.g., mounts 46A-46G shown in
It is reiterated here that the simplified depiction of the heat exchanger 36 and its parts in
Before addressing details of the header 18, 19 design according to one embodiment of the present disclosure,
As mentioned above,
In the embodiment of
It is noted here that the terms “base portion,” “curved fillet,” and “drafted wall” are used herein for the sake of convenience only to illustrate and discuss structural details of the header 18. These terms do not imply piecemeal construction of the header 18 or that the header 18 is composed of disjointed parts. The entire header 18 may be formed in such a manner as to result in a unitary, homogenous structure that has cross-sectional continuity throughout its metallic composition. In other words, the header 18 is not necessarily formed by forming each “part” 68, 70, 72 individually and then “joining” these parts to arrive at the final header structure. Rather, the header 18 may be a unitary, homogenous structure, having all of its “parts” formed simultaneously.
Referring back to
As in the case of the header in
It is observed here that, during robotic welding, the cast tanks 20, 22 may be held in place (in a spaced-apart manner) by gripping the tanks 20, 22 through their indentations 32A-32F. The core 11 may be then inserted in the spacing between the tanks 20, 22 and the tanks 20, 22 may be suitably moved to snugly fit onto their corresponding headers 18, 19. After tanks 20, 22 are securely mounted over corresponding headers 18, 19, a robotic welding arm may be brought in to weld the tank's side panels (e.g., the longer side panels 21B, 21E, etc.) onto the header 18, 19 wall. The tanks 20, 22 may be mounted over the headers 18, 19 so as to provide consistency in tank-to-header seam locations and facilitate expeditious and economical robotic welding.
Furthermore, as mentioned before, the cast tank 20 may not require any machining prior to its welding onto the header 18. The lack of machining may result in improved material flow path and decreased cost because of the simpler three-step (cast-weld-assemble) process discussed herein. On the other hand, in traditional cast tank designs, additional machining may be needed to create a flat bottom tank surface to facilitate welding of the tank onto the header and to provide a method for sidebracket attachment. Although the machining may succeed in creating a flat surface, it may fail in creating an interchangeable tank design that has a consistent tank-to-header seam location whenever such a tank is mounted on a header and such machining requires additional time and effort to perform. The cast tanks 20, 22 according to the teachings of the present disclosure may provide interchangeable tank designs without the need for any machining. Such cast tanks 20, 22 may be well suited for medium production levels of at least 2000 units per year for industrial heat exchangers.
From the front view in
It is noted here that the foregoing discussion provides details of an exemplary embodiment in which the substantially I-shaped isolators 88 may suitably fit in the corresponding approximately T-shaped indentations (e.g., indentations 32A, 32B, 32C, etc. shown in
In various embodiments, the heat exchanger (e.g., the heat exchanger 36) may include one or more isolators. In those embodiments, each isolator may be shaped to be at least partially disposed in one or more indentations, such as one isolator engaging two or more indentations. For example, the isolator may be shaped with two protrusions that each fit into a different of two indentations
a tank having at least two indentations; and one or more isolators engaging the at least two indentations, each isolator having a base at least partially disposed in one of the indentations and a coupler extending from the base for coupling the tank to at least one other component of the heat exchanger.
Such isolators may be constructed in a manner similar to the construction of the substantially I-shaped isolators discussed hereinabove. Hence, additional details of different configurations of indentations and corresponding matching isolators are not provided herein for the sake of brevity.
Another embodiment is a method of attaching a header to a tank. As described herein, the tank may be cast, such as out of aluminum, or molded, such as out of plastic. This embodiment is discussed below with respect to header 18 and tank 20, though the method may similarly apply to header 19 and tank 22. Referring to
The dimension along the rim 23, as introduced above, may be a consistent distance between opposing sides (i.e., distance between longer side panels 21B and 21E, and distance between shorter side panels 21C and 21D).
In an embodiment, the aforementioned consistent dimensions (i.e. dimension from the top panel 21A to the rim 23 and the dimension along the rim 23) and location of the rim 23 are maintained within a tight tolerance that may not be achievable using sheet goods.
The header 18 may be formed with a base portion 68 and a drafted wall 72 extending from the base portion 68. The header 18 may be moved or slid within the tank 20 such that the drafted wall 72 moves adjacent to or slides along the inner surface 76A-76B of the side 21B-21E of the tank 20. Because of the outwardly slanted inner surface 76A-76B of the side 21B-21E of the tank 20 and outwardly slanted outer surface of the drafted wall 72 of the header 18, the drafted wall 72 may, in an embodiment, remain in contact or nearly in contact with the inner surface 76B near the rim 23 as the drafted wall 72 moves or slides within the tank 20. Thus, at different of those moved distances, the header 18 may still be welded to the tank 20 along the rim 23. This enables a fixed distance between each tank-to-header joint to be maintained. This fixed distance facilitates robotic welding, since the robotic welder can be programmed to automatically weld the header 18 and tank 20 together along the consistent, and thus known, dimension.
In an embodiment, the drafted wall 72 of the header 18 remains in contact or nearly in contact with inner surface 76A-76B of the side 21B-21E of the tank 20 near the rim 23 as the drafted wall 72 slides within the tank 20 because, at least in part, the outer surface of the drafted wall 72 is outwardly slanted. In another embodiment, the drafted wall 72 of the header 18 remains in contact or nearly in contact with the inner surface 76A-76B of the side 21B-21E of the tank 20 near the rim 23 as the drafted wall 72 slides within the tank 20 because, at least in part, both the outer surface of the drafted wall 72 and the inner surface 76A-76B of the side 21B-21D of the tank 20 are outwardly slanted.
In an embodiment, the drafted wall 72 is adjacent to or slides along the inner surface 76B of the side 21B-21D of the tank 20. Thus, a gap may exist between the drafted wall 72 and the tank 20 having a width not more than could be filled by a welding bead, or the drafted wall 72 may contact the tank 20 or slide along the inner surface 76B of the side 21B-21D of the tank 20. For example, in one embodiment, the drafted wall 72 may slide along the inner surface 76B of the side 21B-21D of the tank 20, thus overlapping the tank 20 up to one inch.
The foregoing embodiments describe an aluminum (or aluminum alloy) industrial heat exchanger (or radiator) that provides consistency in tank-to-header joint locations to allow use of robotic welding of tanks to headers. A header design that includes the combination of a curved fillet and a drafted wall facilitates easy insertion of the radiator tank onto the core of the radiator and allows for a degree of unpredictable core growth during baking of the core. The tanks are made by casting in such a manner that machining is not required. The inner surface of the aluminum cast tank is welded onto the header and is configured to match the geometry of the drafted wall of the header. Each cast tank of the radiator includes suitably-shaped indentations (e.g., approximately sideways T-shaped indentations) at the four corners of the cast tank to facilitate linking of the cast tanks to (frequently stronger and less expensive) steel sidebrackets using sidebracket mounts (or isolators) that may be made of a flexible material molded around a threaded insert. Sidebrackets may furthermore be captured by attaching nuts to the threaded inserts of the sidebracket mounts, without requiring any machining or welding/brazing operations. The sidebracket mounts or isolators thus allow for flexible mounting of sidebrackets, and allow for thermal expansion of the core. As mentioned before, various dimensional details provided herein are exemplary in nature, and can be modified as needed without departing from the scope of the teachings in the present disclosure. Also, although certain discussion herein focuses on an industrial heat exchanger for internal combustion engines, the radiator design principles discussed herein may be used to design similar heat exchangers for use in other applications, including, for example, heat exchangers used in automotives, refrigeration, hydraulic oil coolers, etc.
While the disclosure has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the embodiments. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.
Claims
1. A heat exchanger, comprising:
- a tank including a plurality of indentations;
- a header to be used as part of a core of the heat exchanger, said header comprising: a base portion including a plurality of apertures therein for receiving fluid-carrying tubes of the heat exchanger therethrough; a drafted wall circumferentially surrounding said base portion and slanted to the plane thereof, said drafted wall providing an attachment surface for welding said tank onto said core; and a curved fillet linking said base portion to said drafted wall and providing alignment support during said welding of said tank onto said core; and
- a plurality of sidebracket mounts for flexible mounting of at least one sidebracket, each sidebracket mount comprising a base and a coupler that extends from the base, and wherein: each sidebracket mount base is to engage one of said plurality of indentations of said tank by being at least partially disposed in the one of said plurality of indentations to engage the sidebracket mount with the tank; and each sidebracket coupler is to attach at least one sidebracket by extending through the sidebracket.
2. The heat exchanger of claim 1, wherein a combination of said drafted wall and said curved fillet results in maintaining a consistent tank-to-header seam location.
3. The heat exchanger of claim 1, wherein curvature of said curved fillet is configured to accommodate slanted orientation of said drafted wall respective to the plane of said base portion so as to provide a unitary structure for said header having a cross-sectional continuity from said base portion to said drafted wall.
4. The heat exchanger of claim 1, wherein said curved fillet is continuous along said circumference of said drafted wall and extends to a distal line, and wherein a first plane tangential to said distal line of said curved fillet is parallel to and higher than the base portion, and wherein said first plane is parallel to and lower than a third plane tangential to the tops of said fluid-carrying tubes when said fluid-carrying tubes are received by said base portion.
5. The heat exchanger of claim 1, wherein said header is formed of an aluminum alloy suitable for allowing brazing of said header to said fluid-carrying tubes.
6. A heat exchanger, comprising:
- a tank comprising one or more indentations;
- a core of said heat exchanger, said core comprising: a plurality of fluid-carrying tubes; a plurality of fins interleaved with said plurality of fluid-carrying tubes, wherein a set of fins from said plurality of fins is disposed along a first pair of opposite sides of said core; and a pair of headers, wherein each header in said pair of headers is disposed over said plurality of fluid-carrying tubes along a corresponding one of a second pair of opposite sides of said core, wherein each header in said pair of headers includes: a base portion including a plurality of apertures therein for receiving said plurality of fluid-carrying tubes therethrough; a drafted wall circumferentially surrounding said base portion and outwardly slanted, said drafted wall providing an attachment surface for welding said tank onto said core; and a curved fillet linking said base portion to said drafted wall and providing alignment support during said welding of said tank onto said core; and
- one or more sidebracket mounts each comprising a base and a coupler that extends from the base, wherein: each sidebracket mount base is to engage one of the one or more indentations of said tank by being at least partially disposed in the one of said one or more plurality of indentations; and each sidebracket coupler is to attach at least one sidebracket by extending through the sidebracket.
7. The heat exchanger of claim 6, wherein a combination of said drafted wall and said curved fillet in each said header results in maintaining a consistent tank-to-header seam location during said welding of said tank despite occurrence of different amounts of vertical core growth during brazing of different parts of said core.
8. The heat exchanger of claim 6, wherein said curved fillet is continuous along said circumference of said drafted wall and extends to a distal line, and wherein a first plane tangential to said distal line of said curved fillet is parallel to and higher than the base portion, and wherein said first plane is parallel to and lower than a third plane tangential to the tops of said fluid-carrying tubes when said fluid-carrying tubes are received by said base portion.
9. The heat exchanger of claim 6, further comprising:
- a pair of side plates disposed over said set of fins along said first pair of opposite sides of said core.
10. The heat exchanger of claim 9, wherein said plurality of fluid-carrying tubes, said plurality of fins, said pair of headers, and said pair of side plates are formed of aluminum alloy materials.
11. The heat exchanger of claim 9, wherein said plurality of fluid-carrying tubes, said plurality of fins, said pair of headers, and said pair of side plates are brazed together to form a unitary structure for said core.
Type: Application
Filed: Sep 16, 2013
Publication Date: Jan 16, 2014
Applicant: RICHARDSON COOLING PACKAGES (New Castle, PA)
Inventors: David J. Richardson (Edinburg, PA), Brian Meier (Pittsburgh, PA)
Application Number: 14/028,515
International Classification: F28F 21/08 (20060101);